Dehumidifying device, heater element for dehumidifying device, and vehicle interior dehumidifying system

Abstract

A dehumidification device 100 comprises: a heater element which comprises a honeycomb structure having a peripheral wall 101 and partitions 102 disposed on the inside of the peripheral wall 101 and defining and forming a plurality of cells 104 each serving as a channel extending from a first end surface 103a to a second end surface 103b, at least the partitions 102 being made of a material having PTC characteristics, and which further includes a pair of electrodes (first electrode 110a and second electrode 110b) provided to the honeycomb structure; and a dehumidifying-material-containing layer 120 disposed on the surfaces of the partitions 102 and including a dehumidifying material having a water-release temperature of 30-70°C.

Description

[Technical Field]

[0001] The present invention relates to a dehumidifying device, a heater element for a dehumidifying device, and a vehicle compartment dehumidifying system. [Background technology]

[0002] There is a growing demand to reduce CO2 emissions from automobiles as a measure to combat global warming. There is also a growing demand to reduce emissions of nitrogen oxides and other substances from automobiles as a measure to combat air pollution. Electric vehicles, which are effective in addressing these issues, are attracting attention. However, electric vehicles lack the internal combustion engine that is the heating source used in conventional vehicles, and so they face the problem of a lack of heating sources. Since much of the heating energy is lost through ventilation, reducing ventilation is one possible solution. However, without ventilation, moisture (water vapor) from people's breath increases the humidity inside the vehicle, and when it comes into contact with the cold window glass, it fogs up, compromising driving safety. In response to this, a dehumidifying device has been proposed that reduces the humidity in the vehicle cabin by having the moisture in the vehicle cabin adsorbed onto the dehumidifying material of a dehumidifier, and that heats the air using a heating device located upstream of the dehumidifier, and then circulates the air through the dehumidifier to release the moisture outside the vehicle and regenerate the dehumidifying material of the dehumidifier (for example, Patent Document 1).The heating device used in this dehumidifying device uses a heater element that utilizes Joule heat.

[0003] However, heater elements that utilize Joule heat tend to be large, posing a problem of taking up space inside the vehicle. Therefore, it is desirable to use a more compact heater element. In this regard, heater elements equipped with a honeycomb structure with PTC characteristics are known to be advantageous because they can increase the heat transfer area per unit volume and prevent excessive heat generation (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6513170 [Patent Document 2] International Publication No. 2020 / 036067 Summary of the Invention [Problem to be solved by the invention]

[0005] Existing dehumidification devices have a heating device (heating element) installed upstream of the dehumidifying material, which requires space for both the dehumidifying material and the heating device, making them prone to becoming large. Furthermore, existing dehumidification devices indirectly heat the dehumidifying material that has absorbed moisture with air heated by the heating device, which means the dehumidifying material regeneration efficiency is insufficient. Furthermore, depending on the type of dehumidifying material used in the dehumidifying device, the temperature at which the absorbed moisture can be released may be high, which can increase the amount of electricity required to heat the material.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a dehumidifying device that has high regeneration efficiency of desiccant and can be made compact and consume less power, a heater element for a dehumidifying device that is useful for producing this dehumidifying device, and a vehicle interior dehumidifying system that includes this dehumidifying device. [Means for solving the problem]

[0007] As a result of extensive research into the structure of dehumidifying devices, the present inventors have found that the above-mentioned problems can be solved by providing a dehumidifying material-containing layer containing a dehumidifying material with a water release temperature of 30 to 70°C on the surface of the partition walls of a honeycomb structure constituting a heater element, and have thus completed the present invention. That is, the present invention is exemplified as follows.

[0008] (1) A gas turbine engine includes an outer peripheral wall and partition walls disposed inside the outer peripheral wall, which partition walls define a plurality of cells that serve as flow paths extending from a first end face to a second end face. ,before bulkhead and the outer peripheral wall Material that has PTC properties Consists of a honeycomb structure and a heater element including a pair of electrodes provided on the honeycomb structure; a dehumidifying material-containing layer provided on the surface of the partition wall and containing a dehumidifying material having a water release temperature of 30 to 70°C; A dehumidifying device comprising:

[0009] (2) The dehumidifying device according to (1), wherein the material having PTC properties has a Curie point of 30 to 70°C.

[0010] (3) The dehumidifying device according to (2), wherein the temperature difference between the water release temperature of the dehumidifying material and the Curie point of the material having PTC properties is within ±10°C.

[0011] (4) The dehumidifying device according to any one of (1) to (3), wherein the dehumidifying material is at least one selected from the group consisting of aluminosilicate, silica gel, silica, graphene oxide, polymer adsorbents, polystyrene sulfonic acid, and metal-organic frameworks.

[0012] (5) The dehumidifying device according to any one of (1) to (4), wherein the material having PTC properties is mainly composed of barium titanate.

[0013] (6) The barium titanate is selected from the following [i] to [iii]: [i](Ba 1-x-y Sr x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.15 to 0.25, and y is 0.0001 to 0.01) [ii](Ba 1-x-y Sn x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.05 to 0.15, and y is 0.0001 to 0.01) [iii](Ba 1-x-y Zr x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.12 to 0.18, and y is 0.0001 to 0.01). The dehumidifying device according to (5), wherein the dehumidifying device is one or more selected from the following:

[0014] (7) The dehumidifying device according to any one of (1) to (6), wherein the dehumidifying material-containing layer further contains an antibacterial material.

[0015] (8) The dehumidifying device according to (7), wherein the antibacterial material is at least one selected from a visible light responsive photocatalyst, silver, copper, and zinc.

[0016] (9) The dehumidifying device according to any one of (1) to (8), wherein the pair of electrodes is provided on the first end surface and the second end surface.

[0017] (10) The dehumidifying device according to (9), further comprising terminals connected to the pair of electrodes.

[0018] (11) A fuel cell device having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that serve as flow paths extending from a first end face to a second end face. ,before bulkhead and the outer peripheral wall Material that has PTC properties Consists of A honeycomb structure and a pair of electrodes provided on the honeycomb structure, The material having PTC properties is a heater element for a dehumidifying device, the Curie point of which is 30 to 70°C.

[0019] (12) The heater element for a dehumidifying device according to (11), wherein the material having PTC properties is mainly composed of barium titanate.

[0020] (13) The barium titanate is selected from the following [i] to [iii]: [i](Ba 1-x-y Sr x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.15 to 0.25, and y is 0.0001 to 0.01) [ii](Ba 1-x-y Sn x A y)TiO3 (wherein A represents one or more rare earth elements, x is 0.05 to 0.15, and y is 0.0001 to 0.01) [iii](Ba 1-x-y Zr x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.12 to 0.18, and y is 0.0001 to 0.01). The heater element for a dehumidifying device according to (12), wherein the heater element is one or more selected from the following:

[0021] (14) A dehumidifying device according to any one of (1) to (10), a battery capable of applying a voltage to the dehumidifying device; an inlet pipe communicating the vehicle compartment with an inlet of the dehumidifying device; an outflow pipe communicating an outlet of the dehumidifying device with the vehicle interior and the outside of the vehicle; a switching valve provided in the outflow pipe, which can switch the flow of air passing through the outflow pipe to the vehicle compartment or to the outside of the vehicle; A vehicle interior dehumidification system. [Effects of the Invention]

[0022] According to the present invention, it is possible to provide a dehumidifying device that has high regeneration efficiency of a desiccant and can be made smaller and consume less power, a heater element for a dehumidifying device that is useful for producing this dehumidifying device, and a vehicle interior dehumidifying system that includes this dehumidifying device. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic view of a first end face side of a dehumidifying device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along line aa' in FIG. [Figure 3] FIG. 4 is a schematic view of a first end face side of a dehumidifying device according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view taken along line aa' in FIG. [Figure 5]FIG. 1 is a schematic diagram showing the configuration of a vehicle compartment dehumidification system according to an embodiment of the present invention. [Figure 6] FIG. 10 is a schematic diagram showing the configuration of a vehicle compartment dehumidifying system according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] A dehumidifying device according to an embodiment of the present invention comprises a honeycomb structure having an outer peripheral wall and partition walls arranged inside the outer peripheral wall to define a plurality of cells that serve as flow paths extending from a first end face to a second end face, with at least the partition walls being made of a material having PTC (Positive Temperature Coefficient) properties; a heater element including a pair of electrodes provided on the honeycomb structure; and a dehumidifying material-containing layer provided on the surface of the partition walls and containing a dehumidifying material having a water release temperature of 30 to 70°C. In this specification, the "water release temperature" of a dehumidifying material means the temperature at which the moisture adsorbed in the dehumidifying material can be released. The dehumidifying device according to the embodiment of the present invention can be miniaturized by adopting the above-described configuration, since it eliminates the need for a separate space for arranging a dehumidifying material in addition to the heater element. Furthermore, since the heater element can directly heat the dehumidifying material-containing layer, the regeneration efficiency of the dehumidifying material can be improved. Furthermore, since the water release temperature of the dehumidifying material contained in the dehumidifying material-containing layer is controlled, the amount of electricity required to increase the heating temperature can be reduced.

[0025] Furthermore, a heater element for a dehumidifying device according to an embodiment of the present invention includes a honeycomb structure having an outer peripheral wall and partition walls arranged inside the outer peripheral wall to define a plurality of cells that serve as flow paths extending from a first end face to a second end face, at least the partition walls being made of a material having PTC characteristics, and a pair of electrodes provided on the honeycomb structure, wherein the material having PTC characteristics has a Curie point of 30 to 70°C. By configuring the heater element for a dehumidifying device according to an embodiment of the present invention as described above, it becomes possible to provide a dehumidifying material-containing layer containing a dehumidifying material having a water release temperature of 30 to 70°C.

[0026] Furthermore, the vehicle compartment dehumidification system according to an embodiment of the present invention comprises the dehumidifying device, a battery capable of applying voltage to the dehumidifying device, an inlet pipe connecting the vehicle compartment with the inlet of the dehumidifying device, an outlet pipe connecting the outlet of the dehumidifying device with the vehicle compartment and the outside of the vehicle, and a switching valve provided in the outlet pipe that can switch the flow of air passing through the outlet pipe to either the vehicle compartment or the outside of the vehicle. The vehicle compartment dehumidifying system according to the embodiment of the present invention can be made smaller and consume less power by being configured as described above.

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications and improvements made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention are also within the scope of the present invention.

[0028] (1. Dehumidifying device)

[0029] The dehumidifying device according to the embodiment of the present invention can be suitably used to adjust the indoor humidity in various vehicles such as automobiles. Examples of vehicles include, but are not limited to, automobiles and trains. Examples of automobiles include, but are not limited to, gasoline-powered vehicles, diesel-powered vehicles, gas-fueled vehicles using CNG (compressed natural gas) or LNG (liquefied natural gas), fuel cell vehicles, electric vehicles, and plug-in hybrid vehicles. The dehumidifying device according to the embodiment of the present invention can be suitably used in vehicles without internal combustion engines, such as electric vehicles and trains.

[0030] In addition to vehicles, the dehumidifying device according to the embodiment of the present invention can also be used to adjust the indoor humidity in buildings such as houses, offices, factories, stores, and warehouses, as well as in vehicles such as ships and airplanes.

[0031] Fig. 1 is a schematic view of a first end face side of a dehumidifying device 100 according to one embodiment of the present invention. Fig. 2 is a schematic view of a cross section taken along line a-a' in Fig. 1. Fig. 3 is a schematic view of a first end face side of a dehumidifying device 100 according to another embodiment of the present invention. Fig. 4 is a schematic view of a cross section taken along line a-a' in Fig. 3. The dehumidifying device 100 includes a honeycomb structure having an outer peripheral wall 101 and partition walls 102 disposed inside the outer peripheral wall 101, a heater element including a pair of electrodes (a first electrode 110a and a second electrode 110b) provided on the honeycomb structure, and a dehumidifying material-containing layer 120 provided on the surface of the partition walls 102. The partition walls 102 define a plurality of cells 104 that serve as flow paths extending from a first end face 103a to a second end face 103b. Each component of the dehumidifying device 100 will be described in detail below.

[0032] (1-1. Heater element) (A) Honeycomb structure The shape of the honeycomb structure is not particularly limited as long as it has an outer peripheral wall 101 and partition walls 102 disposed inside the outer peripheral wall 101 and defining a plurality of cells 104 that form flow paths extending from a first end face 103a to a second end face 103b. For example, the outer shape of a cross section perpendicular to the extension direction of the flow paths of the honeycomb structure (the extension direction of the cells 104) can be a polygon (a quadrangle (rectangle, square), pentagon, hexagon, heptagon, octagon, etc.), a round shape (a circle, an ellipse, an oval, an egg shape, an oval, a rounded quadrangle (a quadrangle in which each side and each corner is curved, the radius of curvature of each side is larger than the radius of curvature of each corner, and the entire quadrangle is curved)), etc. Furthermore, when the outer shape of the cross section is polygonal, the corners may be chamfered. It is particularly preferable that the corners are rounded to prevent damage to the honeycomb structure and to facilitate attachment of other members such as a buffer material to the surface of the outer wall 101. The end faces (first end face 103a and second end face 103b) have the same shape as the cross section. The dehumidifying device 100 of FIGS. 1 and 2 shows, as an example, a case where the outer shape of the cross section of the honeycomb structure is circular and the outer shape of the honeycomb structure as a whole is cylindrical. The dehumidifying device 100 of FIGS. 3 and 4 shows, as an example, a case where the outer shape of the cross section of the honeycomb structure is rectangular with rounded edges and the outer shape of the honeycomb structure as a whole is a square pillar with rounded edges.

[0033] The opening shape of the cells 104 is not particularly limited, and may be polygonal (quadrilateral (rectangle, square), pentagon, hexagon, heptagon, octagon, etc.), round (circular, elliptical, oval, egg, oval, etc.), etc. in a cross section perpendicular to the direction in which the flow channels of the honeycomb structure extend. These shapes may be used alone or in combination of two or more. Among these shapes, quadrilaterals and hexagons are preferred. By providing cells 104 with such shapes, pressure loss during air circulation can be reduced. When the opening shape of the cells 104 is polygonal, the corners may be rounded. In the dehumidifying device 100 of FIGS. 1 to 4, a case in which the opening shape of the cells 104 of the honeycomb structure is square is shown as an example.

[0034] The honeycomb structure may be a honeycomb bonded body having a plurality of honeycomb segments and a bonding layer bonding the outer peripheral surfaces (the outer peripheral surfaces parallel to the extension direction of the honeycomb segments) of the plurality of honeycomb segments together. The use of a honeycomb bonded body makes it possible to increase the total cross-sectional area of ​​the cells 104, which is important for ensuring the air flow rate, 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-like material obtained by adding a solvent such as water to a ceramic material can be used. The bonding material may contain a material having PTC properties or may contain the same material as the outer peripheral wall 101 and the partition walls 102. In addition to bonding the honeycomb segments together, the bonding material can also be used as an outer peripheral coating material after the honeycomb segments are bonded.

[0035] It is preferable to appropriately determine the thickness, cell density, and cell pitch (or the opening ratio of the cells 104) of the partition walls 102 in consideration of ensuring the strength of the honeycomb structure, reducing the pressure loss when air passes through the cells 104, ensuring the amount of dehumidifying material-containing layer 120 carried, ensuring the contact area with the air flowing through the cells 104, and the electrical resistance between the end faces. In this specification, the "thickness of the partition wall 102" refers to the length of a line segment that connects the centers of gravity of adjacent cells 104 in a cross section perpendicular to the direction in which the flow channel extends, and that line segment crosses the partition wall 102. The thickness of the partition wall 102 refers to the average value of the thicknesses of all the partition walls 102. In this specification, the "cell density" is a value obtained by dividing the number of cells by the area of ​​one end face of the honeycomb structure (the total area of ​​the partition walls 102 and the cells 104 excluding the outer peripheral wall 101). In this specification, the "cell pitch" refers to a value calculated by the following calculation. First, the area per cell is calculated by dividing the area of ​​one end face of the honeycomb structure (the total area of ​​the partition walls 102 and the cells 104 excluding the outer peripheral wall 101) 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 "opening ratio of the cells 104" refers to a value obtained by dividing the total area of ​​the cells 104 partitioned by the partition walls 102 in a cross section perpendicular to the direction in which the flow paths of the honeycomb structure extend by the area of ​​one end face (the total area of ​​the partition walls 102 and the cells 104 excluding the outer peripheral wall 101). Note that when calculating the opening ratio of the cells 104, layers provided on the partition walls 102, such as the pair of electrodes (first electrode 110a and second electrode 110b) and the dehumidifying material-containing layer 120, are not taken into consideration.

[0036] In terms of carrying a sufficient amount of the dehumidifying material-containing layer 120, an advantageous embodiment is one in which the thickness of the partition walls 102 is 0.180 mm or less and the cell density is 100 cells / cm. 2 In a preferred embodiment, the thickness of the partition walls 102 is 0.150 mm or less, and the cell density is 95 cells / cm. 2 In a more preferred embodiment, the thickness of the partition walls 102 is 0.120 mm or less, and the cell density is 90 cells / cm. 2 or less, and the cell pitch is 1.3 mm or more.

[0037] From the viewpoint of ensuring the strength of the honeycomb structure and keeping the electrical resistance low, the lower limit of the thickness of the partition walls 102 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, keeping the electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption in the dehumidifying material-containing layer 120, the lower limit of the cell density is 30 cells / cm. 2 Preferably, 35 cells / cm or more. 2 More preferably, 40 cells / cm or more. 2 It is even more preferable that the above is true. From the viewpoint of ensuring the strength of the honeycomb structure, maintaining low electrical resistance, and increasing the surface area to promote reaction, adsorption, and desorption by the dehumidifying material-containing layer 120, 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.

[0038] An advantageous embodiment from the viewpoint of achieving both a reduction in pressure loss and maintaining strength is one in which the thickness of the partition walls 102 is 0.08 mm to 0.36 mm and the cell density is 2.54 cells / cm. 2 ~140 cells / cm 2 , and the opening ratio of the cells 104 is 0.70 or more. In a preferred embodiment, the thickness of the partition walls 102 is 0.09 mm to 0.35 mm, and the cell density is 15 cells / cm. 2 ~100 cells / cm 2 , and the opening ratio of the cells 104 is 0.75 or more. In a more preferred embodiment, the thickness of the partition walls 102 is 0.10 mm to 0.30 mm, and the cell density is 20 cells / cm. 2 ~90 cells / cm 2 , and the aperture ratio of the cell 104 is 0.77 or more.

[0039] From the viewpoint of ensuring the strength of the honeycomb structure, the upper limit of the opening ratio of the cells 104 is preferably 0.94 or less, more preferably 0.92 or less, and even more preferably 0.90 or less.

[0040] The thickness of the outer peripheral wall 101 is not particularly limited, but is preferably determined based on the following points: First, from the viewpoint of reinforcing the honeycomb structure portion, the thickness of the outer peripheral wall 101 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 the electrical resistance to suppress the initial current and reducing the pressure loss when air flows through, the thickness of the outer peripheral wall 101 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 wall 101 refers to the length in the normal direction of the outer surface from the boundary between the outer wall 101 and the outermost cell 104 or partition wall 102 to the outer surface of the honeycomb structure in a cross section perpendicular to the direction in which the flow path extends.

[0041] The length of the honeycomb structure in the direction in which the flow channels extend and the cross-sectional area perpendicular to the direction in which the flow channels extend are not particularly limited and may be adjusted according to the required size of the dehumidification device 100. For example, when the honeycomb structure is used in a compact dehumidification device 100 while ensuring a predetermined function, the length of the honeycomb structure in the direction in which the flow channels extend is 2 to 50 mm, typically 5 to 50 mm, and the cross-sectional area perpendicular to the direction in which the flow channels extend is 30 to 400 cm. 2 , typically 50-150 cm 2 It can be said that:

[0042] The partition walls 102 constituting the honeycomb structure are made of a material that can generate heat when electricity is applied, specifically, a material having PTC characteristics. If necessary, the outer peripheral wall 101 may also be made of a material having PTC characteristics like the partition walls 102.

[0043] Because the dehumidifying material-containing layer 120 is provided on the partition walls 102, it is possible to directly heat the dehumidifying material-containing layer 120 by heat transfer from the heat-generating partition walls 102 (and the outer peripheral wall 101, if necessary). Furthermore, materials with PTC characteristics have the property that, when the temperature rises and exceeds the Curie point, the resistance value rises sharply, making it difficult for electricity to flow. Therefore, when the heater element becomes hot, the partition walls 102 (and the outer peripheral wall 101, if necessary) limit the current flowing therethrough, thereby suppressing excessive heat generation by the heater element. Therefore, it is also possible to suppress thermal degradation of the dehumidifying material-containing layer 120 due to excessive heat generation.

[0044] From the viewpoint of obtaining appropriate heat generation, the lower limit of the volume resistivity at 25°C of a material having PTC characteristics is preferably 0.1 Ω·cm or more, more preferably 0.5 Ω·cm or more, even more preferably 1 Ω·cm or more, and even more preferably 2 Ω·cm or more. From the viewpoint of generating heat at a low driving voltage, the upper limit of the volume resistivity at 25°C of a material having PTC characteristics is preferably 50 Ω·cm or less, preferably 30 Ω·cm or less, more preferably 18 Ω·cm or less, and even more preferably 16 Ω·cm or less. Therefore, the range of the volume resistivity at 25°C of a material having PTC characteristics can be, for example, 0.1 Ω·cm to 50 Ω·cm. In this specification, the volume resistivity at 25°C of a material having PTC characteristics is measured in accordance with JIS K6271:2008.

[0045] From the viewpoint of being able to generate heat when electrically applied and having PTC characteristics, the outer peripheral wall 101 and the partition walls 102 are preferably made of a material whose main component is barium titanate (BaTiO3), and more preferably made of ceramics composed of a material whose main component is barium titanate (BaTiO3)-based crystal particles in which part of the Ba is substituted with a rare earth element. In this specification, the term "main component" refers to a component that accounts for more than 50 mass% of the total components. The content of BaTiO3-based crystal particles can be determined by fluorescent X-ray analysis. Other crystal particles can also be measured using a similar method.

[0046] The composition formula of BaTiO3-based crystal particles in which part of Ba is replaced by rare earth elements is (Ba 1-x A x )TiO3, where A represents one or more rare earth elements and x is 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 more preferably La. x is preferably 0.001 or more, more preferably 0.0015 or more, from the viewpoint of preventing the electrical resistance at room temperature from becoming too high. On the other hand, x is preferably 0.009 or less, from the viewpoint of preventing the electrical resistance at room temperature from becoming too high due to insufficient sintering.

[0047] The content of BaTiO3-based crystal particles in the ceramic, in which Ba is partially substituted with a rare earth element, is not particularly limited as long as it is an amount that serves as the main component, but is preferably 90 mass% or more, more preferably 92 mass% or more, and even more preferably 94 mass% or more. The upper limit of the content of BaTiO3-based crystal particles is not particularly limited, but is generally 99 mass% or less, preferably 98 mass% or less.

[0048] From the viewpoint of reducing the environmental load, it is desirable that the materials used for the outer peripheral wall 101 and the partition wall 102 are substantially free of lead (Pb). Specifically, the Pb content of the outer peripheral wall 101 and the partition wall 102 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, air heated by contact with the partition wall 102 during heat generation to be safely applied to living organisms such as humans. The Pb content of the outer peripheral wall 101 and the partition wall 102, calculated as 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).

[0049] In conventional heater elements, the Curie points of the materials constituting the outer peripheral wall and partition walls are generally high, ranging from 100°C to 300°C. Therefore, the dehumidifying material-containing layer uses a dehumidifying material with a water release temperature in this temperature range. However, this dehumidifying material requires high temperatures of 100°C or higher to release the adsorbed moisture and regenerate, which increases the amount of power required. This results in increased battery power consumption, which, for example, reduces the driving range of an electric vehicle. Furthermore, high temperatures of 100°C or higher can have a thermal effect on the casing components housing the heater element and other surrounding components, potentially affecting their functionality and durability.

[0050] In contrast, the dehumidifying material-containing layer 120 used in the dehumidifying device 100 uses a dehumidifying material with a water release temperature of 30 to 70°C, so the Curie point of the material constituting the outer peripheral wall 101 and the partition walls 102 can also be low. From the viewpoint of efficiently heating the dehumidifying material-containing layer 120, the Curie point of the material constituting the outer peripheral wall 101 and the partition walls 102 is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher. Furthermore, from the viewpoint of safety as a component placed indoors, particularly in or near the vehicle interior, and reducing the amount of power required, the Curie point is preferably 70°C or lower, more preferably 60°C or lower, and even more preferably 50°C or lower. Therefore, the Curie point of the material constituting the outer peripheral wall 101 and the partition walls 102 can be in the range of 30°C to 70°C, for example. The Curie point of the material constituting the outer wall 101 and the partition wall 102 may be 100°C or higher, but in order to use it in the dehumidifying device 100, it is necessary to control the amount of power so that the heating temperature of the dehumidifying material-containing layer 120 does not become too high.

[0051] The Curie point of the material forming the outer peripheral wall 101 and the partition walls 102 can be adjusted by the type and amount of the shifter added. For example, the Curie point of barium titanate (BaTiO) is approximately 120°C, but by substituting part of the Ba and Ti with one or more of Sr, Sn, and Zr, the Curie point can be shifted to a lower temperature.

[0052] Barium titanate having a Curie point of 30° C. to 70° C. is not particularly limited, but can be represented by, for example, the following composition formulas [i] to [iii]. [i](Ba 1-x-y Sr x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.15 to 0.25, and y is 0.0001 to 0.01) [ii](Ba 1-x-y Sn x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.05 to 0.15, and y is 0.0001 to 0.01) [iii](Ba 1-x-y Zr x A y )TiO3 (wherein A represents one or more rare earth elements, x is 0.12 to 0.18, and y is 0.0001 to 0.01).

[0053] In this specification, the Curie point is measured by the following method: A sample is attached to a sample holder for measurement and placed in a measurement tank (e.g., MINI-SUBZERO MC-810P, manufactured by ESPEC Corporation), and the change in the sample's electrical resistance with respect to temperature change when the temperature is raised from 10°C is measured using a DC resistance meter (e.g., multimeter 3478A, manufactured by YOKOGAWA HEWLETT PACKARD, LTD.). The Curie point is determined as the temperature at which the resistance value is twice the resistance value at room temperature (20°C) based on the electrical resistance-temperature plot obtained by the measurement.

[0054] (B) Electrode A pair of electrodes (first electrode 110a and second electrode 110b) is provided at any position of the honeycomb structure. The pair of electrodes can be provided at opposing positions, for example, on the first end face 103a and second end face 103b of the honeycomb structure or on the surface of the outer wall 101 parallel to the direction in which the flow channels of the honeycomb structure extend. In particular, from the viewpoint of efficiently generating heat from the honeycomb structure, it is preferable to provide the pair of electrodes on the first end face 103a and second end face 103b of the honeycomb structure. That is, the first electrode 110a is provided on the first end face 103a, and the second electrode 110b is provided on the second end face 103b. Then, by applying a voltage between the first electrode 110a and the second electrode 110b, it becomes possible to generate heat in the honeycomb structure by Joule heat.

[0055] Specifically, the first electrode 110a covers part or all of the surface of the partition wall 102 that forms the first end face 103a. The second electrode 110b covers part or all of the surface of the partition wall 102 that forms the second end face 103b. To facilitate current spreading across the entire first end face 103a, the first electrode 110a preferably covers 80% or more, more preferably 90% or more, and even more preferably 99% or more of the area of ​​the portion of the first end face 103a excluding the openings of the cells 104 (the partition wall portion and the outer peripheral wall portion). Similarly, to facilitate current spreading across the entire second end face 103b, the second electrode 110b preferably covers 80% or more, more preferably 90% or more, and even more preferably 99% or more of the area of ​​the portion of the second end face 103b excluding the openings of the cells 104 (the partition wall portion and the outer peripheral wall portion).

[0056] The first electrode 110a and the second electrode 110b are not particularly limited, but may be, for example, a metal or alloy containing at least one selected from Cu, Ag, Al, Ni, and Si. In a preferred embodiment, the first electrode 110a and the second electrode 110b contain pure aluminum and / or an aluminum alloy. Alternatively, an ohmic electrode capable of making ohmic contact with the outer peripheral wall 101 and / or the partition wall 102 having PTC characteristics may be used. For example, the ohmic electrode may contain at least one base metal selected from Al, Au, Ag, and In and at least one dopant selected from Ni, Si, Zn, Ge, Sn, Se, and Te for n-type semiconductors. The first electrode 110a and the second electrode 110b may have a single-layer structure or a stacked structure of two or more layers. When the first electrode 110a and the second electrode 110b have a stacked structure of two or more layers, the materials of the layers may be the same or different. In a preferred embodiment, the first electrode 110a and the second electrode 110b have a single layer of pure aluminum, a two-layer structure of an Al-Ni alloy layer and a pure silver layer, a two-layer structure of a pure aluminum layer and a pure silver layer, or a two-layer structure of an Al-Ni alloy layer and a pure aluminum layer.

[0057] The thickness of the first electrode 110a and the second electrode 110b is not particularly limited and can be appropriately set depending on the method for forming the first electrode 110a and the second electrode 110b. Examples of methods for forming the first electrode 110a and the second electrode 110b include metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition. Alternatively, the electrodes can be formed by applying an electrode paste and then baking it, or by thermal spraying. Furthermore, the electrodes may be formed by joining a metal plate or alloy plate such as a punched metal having through holes at locations corresponding to the openings of the cells 104.

[0058] The average thickness of the first electrode 110a and the second electrode 110b is not limited, but can be, for example, 5 μm or more and 100 μm or less. By setting the lower limit of the average thickness of the first electrode 110a and the second electrode 110b to 5 μm or more, preferably 10 μm or more, and more preferably 20 μm or more, an advantage is obtained in that abnormal heat generation in the electrodes can be avoided. By setting the upper limit of the average thickness of the first electrode 110a and the second electrode 110b to 100 μm or less, preferably 80 μm or less, and more preferably 60 μm or less, an advantage is obtained in that the rigidity of the electrodes can be suppressed and they are less likely to peel off from the end face of the honeycomb structure.

[0059] The average thickness of the first electrode 110a is measured using the following procedure. First, a cross-sectional image of the first electrode 110a is obtained at approximately 50x magnification using a scanning electron microscope or the like. The cross-section is parallel to the direction of the flow channels of the honeycomb structure. In the cross-sectional image, the first electrode 110a is visible for each partition wall 102. Therefore, for each first electrode 110a, the thickness is measured at the center of the length of the partition wall 102 that forms the first end face 103a covered by the first electrode 110a, in a direction perpendicular to the direction of the flow channels. The thickness direction is parallel to the direction of the flow channels. Next, multiple cross-sectional images of the first electrode 110a are obtained uniformly near the first end face 103a of the heater element, and the thicknesses of the first electrode 110a are measured at five or more locations. The average value of all the measured thicknesses is defined as the average thickness of the first electrode 110a. The average thickness of the second electrode 110b is also measured using the same procedure.

[0060] The lower limit of the volume resistivity of the first electrode 110a and the second electrode 110b at 25°C is not particularly limited, but the normally achievable range is 1.0 × 10 -7 The upper limit of the volume resistivity of the first electrode 110a and the second electrode 110b at 25°C is 1.0×10 -5 It is preferable that the resistance is Ω·cm or less, and 1.0×10 -6 It is preferable that the resistance is 5.0×10 Ω·cm or less. -7 It is more preferable that the resistance is Ω·cm or less, and 3.0×10 -7Therefore, the range of the volume resistivity of the first electrode 110a and the second electrode 110b at 25°C is, for example, 1.0×10 -7 Ω cm or more 1.0×10 -5 In this specification, the volume resistivity of first electrode 110a and second electrode 110b at 25°C is measured in accordance with JIS K6271:2008.

[0061] (C)Terminal The heater element may further include terminals (first terminal 111a and second terminal 111b) connected to the pair of electrodes (first electrode 110a and second electrode 110b) to facilitate connection to an external power source. The first terminal 111a is connected to a portion of the outer surface of the first electrode 110a. The second terminal 111b is connected to a portion of the outer surface of the second electrode 110b.

[0062] The connection method between the first electrode 110a and the first terminal 111a, and between the second electrode 110b and the second terminal 111b, is not particularly limited as long as they are electrically conductive. For example, they can be connected by welding, brazing, or mechanical contact. The material of the first terminal 111a and the second terminal 111b is not particularly limited, but can be, for example, a metal. While simple metals and alloys can be used as the metal, from the viewpoint of selecting a material that is resistant to oxidation in humid environments, resistant to migration and electrolytic corrosion even under wet conditions, and easy to bond to the electrodes, it is preferable to select a material that contains one or more selected from pure aluminum, aluminum alloys, and stainless steel. For example, pure aluminum, aluminum alloys, or stainless steel can be used. Alternatively, alloys containing at least one selected from the group consisting of Cr, Fe, Co, Ni, Cu, and Ti can also be used. Among these, Fe-Ni alloys and phosphor bronze are particularly suitable. It is preferable for the terminals to be made of a material similar to the electrode layer on the end face in order to avoid electrolytic corrosion. For example, it is preferable that both the electrode layer and the terminal are made of pure aluminum and / or an aluminum alloy.

[0063] The shape of the first terminal 111a and the second terminal 111b is not limited, but may be, for example, a flat plate. In this case, the plate thickness of the terminal is not limited, but may be, for example, 0.1 to 4 mm, and preferably 0.3 to 2 mm.

[0064] There is no particular limit to the area of ​​the portion of the first end face 103a covered by the first terminal 111a. However, if the first terminal 111a is too small, connecting an energized component to the first terminal 111a becomes difficult. Conversely, if the first terminal 111a is too large, the area blocking the opening of the cell 104 increases, reducing the air flow rate that can flow through the heater element. Therefore, the lower limit of the ratio of the area of ​​the first end face 103a covered by the first terminal 111a to the area of ​​the first end face 103a is preferably 0.5% or more, more preferably 1% or more, and even more preferably 2% or more. Furthermore, the upper limit of the ratio of the area of ​​the first end face 103a covered by the first terminal 111a to the area of ​​the first end face 103a is preferably 10% or less, more preferably 8% or less, and even more preferably 5% or less. Therefore, the ratio of the area of ​​first end face 103a covered by first terminal 111a to the area of ​​first end face 103a can be in the range of, for example, 0.5% to 10%. The same applies to the ratio of the area of ​​second end face 103b covered by second terminal 111b to the area of ​​second end face 103b.

[0065] The lower limit of the volume resistivity of the first terminal 111a and the second terminal 111b at 25°C is not particularly limited, but the normally possible range is 1.0×10 -7 The upper limit of the volume resistivity of the first terminal 111a and the second terminal 111b at 25°C is 1.0×10 -6 It is preferable that the resistance is 5.0×10 Ω·cm or less. -7 It is preferable that the resistance is Ω·cm or less, and 3.0×10 -7 It is more preferable that the resistance is Ω·cm or less, and 2.0×10 -7Therefore, the range of the volume resistivity of the first terminal 111a and the second terminal 111b at 25°C is, for example, 1.0×10 -7 Ω cm or more 1.0×10 -6 In this specification, the volume resistivity of the first terminal 111a and the second terminal 111b at 25°C is measured in accordance with JIS K6271:2008.

[0066] (D) Current-carrying parts The heater element may further include current-carrying components (first current-carrying component 112a and second current-carrying component 112b) connected to the terminals to facilitate connection to an external power source. The first current-carrying component 112a and second current-carrying component 112b are connected to the first terminal 111a and second terminal 111b, respectively. Examples of conductive materials constituting the first current-carrying component 112a and the second current-carrying component 112b include stainless steel, aluminum, aluminum alloy, copper alloy, and copper. The connection method between the first terminal 111a and the first current-carrying component 112a and between the second terminal 111b and the second current-carrying component 112b is not particularly limited as long as they are electrically conductive. For example, they can be connected by welding, brazing, or mechanical contact. In one aspect, the first current-carrying component 112a and the second current-carrying component 112b may be the electric wire itself between an external power source and the first terminal 111a (second terminal 111b), i.e., a copper wire, a copper alloy wire, an aluminum wire, an aluminum alloy wire, or a stainless steel wire. In another aspect, the first current-carrying component 112a and the second current-carrying component 112b may be an intermediate component connecting the electric wire and the first terminal 111a (second terminal 111b). The interface piece may be connected to the wires by, for example, welding, soldering, brazing, crimping, bolting, or any other method.

[0067] (1-2. Dehumidifying material containing layer) The dehumidifying material-containing layer 120 contains a dehumidifying material with a water release temperature of 30 to 70°C. By using such a dehumidifying material, the adsorbed moisture can be released and regenerated in the low temperature range of 30 to 70°C. This reduces the amount of power required to regenerate the dehumidifying material-containing layer 120 and reduces the amount of electricity consumed stored in the battery, thereby extending the driving range of the electric vehicle. The water release temperature of the dehumidifying material is preferably 35 to 65°C, and more preferably 40 to 60°C. In this specification, a dehumidifying material refers to a substance that has the property of being able to adsorb 5 g / g or more of water per 1 g of its dry mass when left for one hour in an environment at room temperature (25°C) and a relative humidity of 50%, and is also called a moisture absorbent. It is preferable that the moisture absorbent adsorbs moisture at a temperature of -20°C to less than 30°C. The dehumidifying material has the function of adsorbing moisture at temperatures between -20°C and below 30°C and desorbing moisture at temperatures between 30°C and 70°C, so the dehumidifying function can be repeatedly obtained by repeatedly turning on and off electricity.

[0068] The temperature difference between the water release temperature of the dehumidifying material and the Curie point of the material having PTC properties (the material constituting the outer wall 101 and the partition walls 102 of the honeycomb structure) is preferably within ±10° C., more preferably within ±8° C., and even more preferably within ±5° C. Such a configuration can prevent the dehumidifying material from being overheated and degraded, thereby enabling the function of the dehumidifying material-containing layer 120 to be maintained for a long period of time.

[0069] The type of dehumidifying material is not particularly limited as long as it has a water release temperature of 30 to 70° C., and examples thereof include aluminosilicate, silica gel, silica, graphene oxide, polymer adsorbent, polystyrene sulfonic acid, and metal organic framework (MOF). These may be used alone or in combination of two or more.

[0070] The aluminosilicate is preferably a porous clay mineral such as AFI-type, CHA-type or BEA-type zeolite, allophane, imogolite, etc. The aluminosilicate is preferably amorphous.

[0071] As the silica gel, it is preferable to use type A silica gel. The polymer adsorbent is preferably one having a polyacrylic acid polymer chain, such as sodium polyacrylate. The metal-organic framework is a crystalline hybrid material containing metal ions and organic molecules (organic ligands). The metal ions are preferably hydrophilic metal ions (e.g., aluminum ions).

[0072] The dehumidifying material-containing layer 120 may further contain a binder. By including a binder, the retention function of the dehumidifying material-containing layer 120 on the surface of the partition wall 102 can be improved. Examples of binders include both organic binders and inorganic binders, with inorganic binders being preferred. There are no particular restrictions on the type of inorganic binder, but examples include alumina sol, silica sol, montmorillonite, boehmite, gamma alumina, and attapulgite. These may be used alone or in combination of two or more. Among these, alumina sol and silica sol are preferred, with silica sol being more preferred, because they facilitate ensuring adhesive strength.

[0073] The dehumidifying material-containing layer 120 may further contain an antibacterial material. By including an antibacterial material, it is possible to prevent the deterioration of the function of the dehumidifying material-containing layer 120 due to the growth of mold and the like, and to prevent the deterioration of the environment inside the vehicle cabin due to the spread of mold into the vehicle cabin. The type of antibacterial material is not particularly limited as long as it has antibacterial properties and does not inhibit the function of the dehumidifying material, and examples include visible light responsive photocatalysts such as titanium oxide, silver, copper, and zinc. These may be used alone or in combination of two or more types. Among these, titanium oxide is preferred, and porous titanium oxide is more preferred.

[0074] The average thickness of the dehumidifying material-containing layer 120 is not particularly limited, but can be, for example, 10 μm or more and 500 μm or less. By setting the lower limit of the average thickness of the dehumidifying material-containing layer 120 to 10 μm or more, preferably 30 μm or more, and more preferably 50 μm or more, sufficient moisture absorption performance can be ensured. By setting the upper limit of the average thickness of the dehumidifying material-containing layer 120 to 500 μm or less, preferably 300 μm or less, and more preferably 200 μm or less, the rigidity of the dehumidifying material-containing layer 120 can be reduced, making it less likely to peel off.

[0075] The average thickness of the dehumidifying material-containing layer 120 is measured by the following procedure. First, a cross-sectional image of the dehumidifying material-containing layer 120 is obtained at approximately 50 magnifications using a scanning electron microscope or the like. The cross-section is parallel to the extension direction of the flow channels of the honeycomb structure. In the cross-sectional image, two dehumidifying material-containing layers 120 sandwiching each partition wall 102 are visible. Therefore, the thickness of each dehumidifying material-containing layer 120 is calculated by dividing the entire cross-sectional area from the first end face 103a to the second end face 103b of each dehumidifying material-containing layer 120 by the length from the first end face 103a to the second end face 103b of the partition wall 102 covered by that dehumidifying material-containing layer 120. Then, multiple cross-sectional images of the dehumidifying material-containing layer 120 are obtained without bias, and the thicknesses of five or more locations of the dehumidifying material-containing layer 120 are measured. The average value of the thicknesses of all the measured dehumidifying material-containing layers 120 is defined as the average thickness of the dehumidifying material-containing layer 120.

[0076] The dehumidifying material-containing layer 120 is provided on the surface of the partition wall 102. The dehumidifying material-containing layer 120 may also be provided on a portion of the outer surface of the first electrode 110a and the second electrode 110b. Furthermore, the dehumidifying material-containing layer 120 may also be provided on the side surfaces of the first electrode 110a and the second electrode 110b. With this configuration, it is possible to prevent the migration of metal components in the electrodes and the resulting short circuit between the electrodes. Here, the outer surface of the first electrode 110a refers to the surface opposite the surface of the first electrode 110a that contacts the first end face 103a. The outer surface of the second electrode 110b refers to the surface opposite the surface of the second electrode 110b that contacts the second end face 103b. Furthermore, the side surface of the first electrode 110a refers to a surface parallel to the thickness direction of the first electrode 110a. The side surface of the second electrode 110b refers to a surface parallel to the thickness direction of the second electrode 110b.

[0077] The reason why the dehumidifying material-containing layer 120 is provided on "a part" of the outer surface of the first electrode 110a is that the part of the outer surface of the first electrode 110a to which the first terminal 111a is connected should not be provided with the dehumidifying material-containing layer 120. Similarly, the reason why the dehumidifying material-containing layer 120 is provided on "a part" of the outer surface of the second electrode 110b is that the part of the outer surface of the second electrode 110b to which the second terminal 111b is connected should not be provided with the dehumidifying material-containing layer 120.

[0078] To enhance the short-circuit prevention effect, the dehumidifying material-containing layer 120 is preferably provided on 80% or more, more preferably 90% or more, and even more preferably 99% or more of the area of ​​the outer surface of the first electrode 110a, where the first terminal 111a is not connected. Similarly, the dehumidifying material-containing layer 120 is preferably provided on 80% or more, more preferably 90% or more, and even more preferably 99% or more of the area of ​​the outer surface of the second electrode 110b, where the second terminal 111b is not connected.

[0079] (1-3. Other additional parts) The dehumidifying device 100 may further include additional components known in the art, as needed. For example, the dehumidifying device 100 may further include a frame capable of holding the heater element. The protective effect of the frame makes the heater element less susceptible to damage when the heater element is installed in the air duct, and the shape of the frame allows for easy installation in an air conditioning system while ensuring electrical insulation from surrounding components.

[0080] The frame for holding the heater element is not particularly limited, but a frame according to one embodiment can be configured to hold the heater element from the first end face 103a side and the second end face 103b side. A frame according to another embodiment can be configured to hold the heater element from the outer peripheral surface side of the outer peripheral wall 101.

[0081] (2. Manufacturing method of dehumidifying device) Next, a method for manufacturing the dehumidifying device 100 will be described by way of example. First, the method for manufacturing the honeycomb structure that constitutes the heater element includes a molding step and a firing step. In the molding step, a clay containing ceramic raw materials including BaCO3 powder, TiO2 powder, and powder of a rare earth nitrate or hydroxide is molded to produce a honeycomb molded body with a relative density of 60% or more. The ceramic raw material can be obtained by dry mixing each powder to obtain a desired composition. The clay can be obtained by adding a dispersion medium, a binder, a plasticizer, and a dispersant to a ceramic raw material and kneading the mixture. The clay may contain additives such as a sifter, a metal oxide, a property improver, and a conductive powder, as needed. The blending amount of components other than the ceramic raw materials is not particularly limited as long as the amount is such that the relative density of the honeycomb formed body is 60% or more.

[0082] Here, in this specification, the "relative density of the honeycomb formed body" means the ratio of the density of the honeycomb formed body to the true density of the entire ceramic raw material. Specifically, it can be calculated by the following formula. Relative density (%) of honeycomb formed body = Density of honeycomb formed body (g / cm 3 ) / true density of the entire ceramic raw material (g / cm 3 ) x 100 The density of the honeycomb formed body can be measured by the Archimedes method using pure water as a medium. The true density of the entire ceramic raw material is calculated by multiplying the total mass (g) of each raw material by the total volume (cm) of each raw material. 3 ) can be calculated by dividing by

[0083] Examples of the dispersion medium include water and a mixed solvent of water and an organic solvent such as alcohol, with water being particularly preferred.

[0084] Examples of binders include organic binders such as methyl cellulose, hydroxypropoxyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. It is particularly preferable to use a combination of methyl cellulose and hydroxypropoxyl cellulose. While one binder may be used alone or two or more binders may be used in combination, it is preferable that the binder does not contain an alkali metal element.

[0085] Examples of the plasticizer include polyoxyalkylene alkyl ether, polycarboxylic acid polymer, and alkyl phosphate ester.

[0086] As the dispersant, surfactants such as polyoxyalkylene alkyl ether, ethylene glycol, dextrin, fatty acid soap, polyalcohol, etc. The dispersant may be used alone or in combination of two or more.

[0087] The honeycomb formed body can be produced by extrusion molding of a clay. In extrusion molding, a die having a desired overall shape, cell shape, partition wall thickness, cell density, etc. can be used.

[0088] The lower limit of the relative density of the honeycomb formed body obtained by extrusion molding is preferably 60% or more, more preferably 65% ​​or more. By controlling the relative density of the honeycomb formed body within this range, it is possible to densify the honeycomb formed body and reduce its electrical resistance at room temperature. The upper limit of the relative density of the honeycomb formed body is not particularly limited, but is generally 80% or less, preferably 75% or less.

[0089] The honeycomb molded body can be dried before the firing step. The drying method is not particularly limited, and for example, a conventionally known drying method such as hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, freeze drying, etc. Among these, a drying method that combines hot air drying with microwave drying or dielectric drying is preferred because it can dry the entire molded body quickly and uniformly.

[0090] The firing step involves holding the temperature at 1150 to 1250°C, then raising the temperature to a maximum temperature of 1360 to 1430°C at a rate of 20 to 600°C / hour, and holding the temperature for 0.5 to 10 hours. By holding the honeycomb formed body at a maximum temperature of 1360 to 1430°C for 0.5 to 10 hours, a honeycomb structure mainly composed of BaTiO3-based crystal particles in which part of Ba has been substituted with a rare earth element can be obtained. Furthermore, by maintaining the temperature at 1150 to 1250°C, Ba2TiO4 crystal particles generated during the firing process are easily removed, and the honeycomb structure portion can be densified. Furthermore, by setting the heating rate from 1150 to 1250°C to the maximum temperature of 1360 to 1430°C at 20 to 600°C / hour, 1.0 to 10.0 mass% of Ba6Ti 17 O 40 Crystal grains can be generated in the honeycomb structure.

[0091] The holding time at 1150 to 1250°C is not particularly limited, but is preferably 0.5 to 10 hours. By holding for such a time, Ba2TiO4 crystal particles formed during the firing process can be stably and easily removed.

[0092] The firing step preferably includes holding the mixture at 900 to 950°C for 0.5 to 5 hours during temperature increase. Holding the mixture at 900 to 950°C for 0.5 to 5 hours efficiently decomposes BaCO3, making it easier to obtain a honeycomb structure having a predetermined composition.

[0093] Before the firing step, a degreasing step may be carried out to remove the binder. The degreasing step is preferably carried out in an air atmosphere to completely decompose the organic components. Furthermore, the firing step is preferably carried out in an air atmosphere from the viewpoint of controlling electrical properties and reducing manufacturing costs. The firing furnace used in the firing step and degreasing step is not particularly limited, but an electric furnace, a gas furnace, or the like can be used.

[0094] A pair of electrodes (first electrode 110a and second electrode 110b) are bonded to the honeycomb structure thus obtained. The first electrode 110a and second electrode 110b can be formed on the first end surface 103a and second end surface 103b of the honeycomb structure by a metal deposition method such as sputtering, vapor deposition, electrolytic deposition, or chemical deposition. The first electrode 110a and second electrode 110b can also be formed by applying an electrode paste to the first end surface 103a and second end surface 103b of the honeycomb structure and then baking it. They can also be formed by thermal spraying. The first electrode 110a and second electrode 110b can be formed as a single layer, or as multiple electrode layers with different compositions. When forming the first electrode 110a and second electrode 110b on the end surfaces using the above method, the thickness of the electrodes can be set to be not excessively large to prevent them from blocking the cells 104.

[0095] Methods for forming the first electrode 110a and the second electrode 110b include, but are not limited to, baking of an electrode paste, dry plating such as sputtering and vapor deposition, wet plating such as thermal spraying, electrolytic deposition, and chemical deposition, and bonding of metal or alloy plates. Each method has a preferred thickness range. For baking of an electrode paste, the thickness can be approximately 5 to 30 μm, for dry plating such as sputtering and vapor deposition, the thickness can be approximately 100 to 1000 nm, for thermal spraying, the thickness can be approximately 10 to 100 μm, and for wet plating such as electrolytic deposition and chemical deposition, the thickness can be approximately 5 to 30 μm. Furthermore, for bonding of metal or alloy plates, the thickness of the electrodes can be approximately 5 to 100 μm.

[0096] Next, the first terminal 111a is connected to the outer surface of the first electrode 110a, and the second terminal 111b is connected to the outer surface of the second electrode 110b. As described above, the connection between the two can be achieved by welding, brazing, mechanical contact, or other methods. Alternatively, the first terminal 111a (second terminal 111b) may be connected by simultaneously baking the electrode paste used to form the first electrode 110a (second electrode 110b).

[0097] Next, as necessary, the first terminal 111a and the second terminal 111b are connected to the first current-carrying component 112a and the second current-carrying component 112b, respectively. As described above, the connection between the two can be achieved by welding, brazing, mechanical contact, or the like.

[0098] A dehumidifying material-containing layer 120 is formed at a predetermined position of the heater element obtained as described above. Specifically, the dehumidifying material-containing layer 120 is provided on the surfaces of the partition walls 102 of the honeycomb structure constituting the heater element, and on parts of the outer surfaces and side surfaces of the first electrode 110a and the second electrode 110b. The dehumidifying material-containing layer 120 formed at each position may be formed separately or simultaneously. The dehumidifying material-containing layer 120 can be simultaneously formed, for example, by the following steps. The heater element before forming the dehumidifying material-containing layer 120 is immersed for a predetermined period of time in a slurry containing a dehumidifying material, and if necessary, an antibacterial material, a binder, a dispersion medium, etc., and excess slurry on the outer peripheral surface of the honeycomb structure is removed by blowing and wiping. The slurry is then dried to form the dehumidifying material-containing layer 120. The drying can be performed while heating the heater element to a temperature of, for example, about 120 to 600°C. The series of steps of immersion, slurry removal, and drying may be performed only once, but by repeating them multiple times, the dehumidifying material-containing layer 120 of the desired thickness can be formed.

[0099] Although an organic binder may be used as the binder, it is preferable to use an inorganic binder because heat can cause smoke, and the components in the smoke may flow into the vehicle interior and worsen the vehicle interior environment. Suitable types of inorganic binders are as described above.

[0100] 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.

[0101] (3. Vehicle compartment dehumidification system) The vehicle compartment dehumidifying system according to the embodiment of the present invention can be used in various vehicles such as automobiles, etc. In particular, the vehicle compartment dehumidifying system according to the embodiment of the present invention can be suitably used in vehicles that do not have an internal combustion engine, such as electric vehicles and trains. In addition, the vehicle interior dehumidification system according to the embodiment of the present invention can also be used to adjust the humidity in the interior spaces of buildings such as homes, offices, factories, stores, warehouses, and freezers, as well as vehicles such as ships and airplanes.

[0102] (3-1. Example of vehicle interior dehumidification system configuration 1) FIG. 5 is a schematic diagram showing the configuration of a vehicle compartment dehumidifying system 1000 according to one embodiment of the present invention. The vehicle interior dehumidification system 1000 includes a dehumidifying device 100, a battery 200 capable of applying a voltage to the dehumidifying device 100, an inlet pipe 400 connecting the vehicle interior with an inlet (inlet end face) of the dehumidifying device 100, an outlet pipe 500 connecting an outlet (outlet end face) of the dehumidifying device 100 with the interior of the vehicle or the outside of the vehicle, and a switching valve 300 provided in the outlet pipe 500 and capable of switching the flow of air flowing through the outlet pipe 500 between the vehicle interior and the outside of the vehicle. The outlet pipe 500 has a first path 500a connecting the outlet (outlet end face) of the dehumidifying device 100 with the interior of the vehicle and a second path 500b connecting the outlet (outlet end face) of the dehumidifying device 100 with the outside of the vehicle. The vehicle compartment dehumidifying system 1000 further includes a ventilator 600 for causing air from the vehicle compartment to flow into the inlet (inlet end face) of the dehumidifying device 100 via the inlet pipe 400.

[0103] 5, the dehumidifying device 100 is arranged such that the inlet (inlet end face) is the first end face 103a and the outlet (outlet end face) is the second end face 103b. However, the dehumidifying device 100 can also be arranged such that the inlet is the second end face 103b and the outlet is the first end face 103a. There may be one dehumidifying device 100, or multiple dehumidifying devices 100 may be arranged in series or parallel.

[0104] The vehicle compartment dehumidification system 1000 is a first mode in which the voltage applied from the battery 200 is turned off, the switching valve 300 is switched so that the air flowing through the outflow pipe 500 passes through the first path 500a, and the ventilator 600 is turned on; a second mode in which the voltage applied from the battery 200 is turned on, the switching valve 300 is switched so that the air flowing through the outflow pipe 500 passes through the second path 500b, and the ventilator 600 is turned on; The driving mode may be:

[0105] The vehicle interior dehumidifying system 1000 may include a control unit 900 that can switch between a first mode and a second mode. The control unit 900 may be configured to alternately execute the first mode and the second mode, for example. By repeatedly switching between the first mode and the second mode in a fixed cycle, moisture (water vapor) in the vehicle interior can be stably discharged to the outside of the vehicle.

[0106] In the first mode, moisture is removed from the air. Specifically, air from the vehicle compartment flows into the inlet (inlet end face) of the dehumidifying device 100 through the inlet pipe 400, passes through the dehumidifying device 100, and then flows out from the outlet (outlet end face) of the dehumidifying device 100. Moisture in the air from the vehicle compartment is removed by being adsorbed by the dehumidifying material in the dehumidifying material-containing layer 120 while passing through the dehumidifying device 100. The air from which moisture has been removed and flows out from the outlet (outlet end face) of the dehumidifying device 100 is returned to the vehicle compartment through the first path 500a of the outlet pipe 500. This air may be supplied to another air conditioning system (e.g., a vehicle HVAC).

[0107] In the second mode, regeneration of the dehumidifying material in the dehumidifying material-containing layer 120 is performed. Specifically, air from the vehicle compartment flows into the dehumidifying device 100 through the inlet (inlet end face) via the inlet pipe 400, passes through the dehumidifying device 100, and then flows out through the outlet (outlet end face) of the dehumidifying device 100. The dehumidifying device 100 generates heat when energized, which heats the dehumidifying material-containing layer 120 supported on the dehumidifying device 100, causing the moisture adsorbed in the dehumidifying material-containing layer 120 to be released (desorbed) from the dehumidifying material-containing layer 120.

[0108] To promote the release of moisture adsorbed in the dehumidifying material-containing layer 120, it is preferable to heat the dehumidifying material to a temperature equal to or higher than the water release temperature depending on the type of dehumidifying material. For example, it is preferable to heat at least a portion of the dehumidifying material, and preferably all of it, to 30 to 70°C, more preferably to 35 to 65°C, and even more preferably to 40 to 60°C. Furthermore, it is desirable to perform the second mode for a time period until the dehumidifying material is sufficiently regenerated. Although this depends on the type of dehumidifying material, for example, the dehumidifying material is preferably heated to the above temperature range for 1 to 10 minutes, more preferably for 2 to 8 minutes, and even more preferably for 3 to 6 minutes.

[0109] In the second mode, air from the vehicle compartment flows out from the outlet (outlet end face) of the dehumidifying device 100 while carrying moisture released from the dehumidifying material while passing through the dehumidifying device 100. The moisture-laden air flowing out from the outlet (outlet end face) of the dehumidifying device 100 passes through the second path 500b of the outlet piping 500 and is discharged outside the vehicle.

[0110] The voltage applied to the dehumidifying device 100 can be switched on and off, for example, by electrically connecting the battery 200 and a pair of terminals (first terminal 111a and second terminal 111b) of the dehumidifying device 100 with an electric wire 810 and operating a power switch 910 provided midway along the wire. The control unit 900 can operate the power switch 910.

[0111] The ventilator 600 can be switched on and off by, for example, electrically connecting the control unit 900 and the ventilator 600 via an electric wire 820 or wirelessly and operating a switch (not shown) of the ventilator 600 with the control unit 900. The ventilator 600 can also be configured so that the ventilation volume can be changed by the control unit 900.

[0112] The switching of the switching valve 300 can be achieved by, for example, electrically connecting the control unit 900 and the switching valve 300 via an electric wire 830 or wirelessly, and operating a switch (not shown) of the switching valve 300 with the control unit 900.

[0113] The switching valve 300 is not particularly limited as long as it is an electrically driven valve having the function of switching flow paths, and examples thereof include a solenoid valve and an electric valve. In one aspect, the switching valve 300 includes an opening / closing door 312 supported on a rotating shaft 310, and an actuator 314 such as a motor that rotates the rotating shaft 310. The actuator 314 is configured to be controllable by the control unit 900.

[0114] In order to stably ensure the above-mentioned functions, it is desirable that the dehumidifying device 100 of the vehicle compartment dehumidifying system 1000 be located close to the vehicle compartment. Therefore, from the viewpoint of preventing electric shock, etc., it is preferable that the driving voltage is 60 V or less. The honeycomb structure used in the dehumidifying device 100 has low electrical resistance at room temperature, so the honeycomb structure can be heated at this low driving voltage. The lower limit of the driving voltage is not particularly limited, but is preferably 10 V or more. If the driving voltage is less than 10 V, the current when heating the honeycomb structure will be large, so the electric wire 810 needs to be thicker. Therefore, the driving voltage of the vehicle compartment dehumidifying system 1000 can be, for example, 10 V or more and 60 V or less.

[0115] 5, the fan 600 is installed upstream of the dehumidification device 100. More specifically, the fan 600 is installed midway through the inlet pipe 400 that connects the dehumidification device 100 to the room, and the air that has passed through the fan 600 flows into the dehumidification device 100 in a manner that it is forced into the dehumidification device 100. Alternatively, the fan 600 may be installed downstream of the dehumidification device 100. In this case, the fan 600 can be installed midway through the outlet pipe 500, for example, and the air that has passed through the inlet pipe 400 flows into the dehumidification device 100 in a manner that it is sucked into the dehumidification device 100.

[0116] (3-2. Example 2 of a vehicle interior dehumidification system) FIG. 6 is a schematic diagram showing the configuration of a vehicle compartment dehumidifying system 2000 according to another embodiment of the present invention. The vehicle interior dehumidification system 2000 includes a first dehumidifying device 100A, a battery 200 capable of applying a voltage to the first dehumidifying device 100A, a first inlet pipe 400A connecting the vehicle interior with an inlet (inlet end face) of the first dehumidifying device 100A, an outlet pipe 500A having a first path 500a connecting the outlet (outlet end face) of the first dehumidifying device 100A with the vehicle interior and a second path 500b connecting the outlet (outlet end face) of the first dehumidifying device 100A with the outside of the vehicle, and a switching valve 300A capable of switching the flow of air flowing through the outlet pipe 500A between the first path 500a and the second path 500b.

[0117] The vehicle interior dehumidification system 2000 also includes a second dehumidifying device 100B, a battery 200 capable of applying voltage to the second dehumidifying device 100B, a second inlet pipe 400B connecting the vehicle interior with an inlet (inlet end face) of the second dehumidifying device 100B, an outlet pipe 500B having a first path 500c connecting the outlet (outlet end face) of the second dehumidifying device 100B with the vehicle interior and a second path 500d connecting the outlet (outlet end face) of the second dehumidifying device 100B with the outside of the vehicle, and a switching valve 300B capable of switching the flow of air flowing through the outlet pipe 500B between the first path 500c and the second path 500d.

[0118] The vehicle cabin dehumidification system 2000 also includes an inlet pipe 400 that branches downstream into a first inlet pipe 400A and a second inlet pipe 400B, and a ventilator 600 for directing air from the vehicle cabin through the inlet pipe 400 into the inlets (inlet end faces) of the first dehumidifying device 100A and the second dehumidifying device 100B.

[0119] In the vehicle compartment dehumidifying system 2000, the first dehumidifying device 100A and the second dehumidifying device 100B are arranged so that the inlet (inlet end face) is the first end face 103a and the outlet (outlet end face) is the second end face 103b. However, the first dehumidifying device 100A and the second dehumidifying device 100B may also be arranged so that the inlet (inlet end face) is the second end face 103b and the outlet (outlet end face) is the first end face 103a. There may be one each of the first dehumidifying device 100A and the second dehumidifying device 100B, or a plurality of them may be arranged in series or parallel.

[0120] The vehicle interior dehumidifying system 2000 may include a switching valve 300C that can switch the flow of air circulating through the inlet pipe 400 between the first inlet pipe 400A and the second inlet pipe 400B. The switching valve 300C can be configured to supply the air circulating through the inlet pipe 400 to both the first inlet pipe 400A and the second inlet pipe 400B while varying the ratio of air flowing through each of the pipes. Furthermore, by having two systems, one that passes through the first dehumidifying device 100A and one that passes through the second dehumidifying device 100B, the vehicle interior dehumidifying system 2000 has the advantage of being able to continue operating even if one of the systems fails.

[0121] The Vehicle Interior Dehumidification System 2000 is The voltage applied to the first dehumidifying device 100A from the battery 200 is turned on. The switching valve 300A is switched so that the air flowing through the outflow pipe 500A passes through the second path 500b, The voltage applied to the second dehumidifying device 100B from the battery 200 is turned off. The switching valve 300B is switched so that the air flowing through the outflow pipe 500B passes through the first path 500c, The switching valve 300C is set so that the air flowing through the inlet pipe 400 can be supplied to both the first inlet pipe 400A and the second inlet pipe 400B, Turn on the ventilator 600. It can be operated in the first mode.

[0122] The Vehicle Interior Dehumidification System 2000 is The voltage applied to the first dehumidifying device 100A from the battery 200 is turned off, The switching valve 300A is switched so that the air flowing through the outflow pipe 500A passes through the first path 500a, The voltage applied to the second dehumidifying device 100B from the battery 200 is turned on. The switching valve 300B is switched so that the air flowing through the outflow pipe 500B passes through the second path 500d, The switching valve 300C is set so that the air flowing through the inlet pipe 400 can be supplied to both the first inlet pipe 400A and the second inlet pipe 400B, Turn on the ventilator 600. It can be operated in a second mode.

[0123] In the first mode, the first dehumidifying device 100A regenerates the dehumidifying material in the dehumidifying material-containing layer 120, while the second dehumidifying device 100B removes moisture from the air. In the second mode, the first dehumidifying device 100A removes moisture from the air, while the second dehumidifying device 100B regenerates the dehumidifying material in the dehumidifying material-containing layer 120. That is, the vehicle compartment dehumidifying system 2000 can simultaneously remove the dehumidifying material in the dehumidifying material-containing layer 120 and moisture. When the first dehumidifying device 100A needs to regenerate the dehumidifying material in the dehumidifying material-containing layer 120, the second dehumidifying device 100B can remove moisture from the air, and vice versa.

[0124] In the first mode, it is preferable to set the switching valve 300C so that the flow rate of air flowing to the second dehumidifying device 100B is increased. In the second mode, it is preferable to set the switching valve 300C so that the flow rate of air flowing to the first dehumidifying device 100A is increased. This can improve the performance of removing moisture from the air by the dehumidifying material of the dehumidifying material-containing layer 120.

[0125] The air from which moisture has been removed and flows out from the outlet (outlet end face) of the first dehumidifying device 100A (second dehumidifying device 100B) is returned to the vehicle cabin through the first path 500a (first path 500c) of the outlet pipe 500A (outlet pipe 500B). This air may be supplied to another air conditioning system (e.g., a vehicle HVAC). The air carrying moisture released from the dehumidifying material-containing layer 120 and flowing out from the outlet (outlet end face) of the first dehumidifying device 100A (second dehumidifying device 100B) is discharged outside the vehicle through the second path 500b (second path 500d) of the outlet pipe 500A (outlet pipe 500B).

[0126] The vehicle interior dehumidifying system 2000 may include a control unit 900 capable of switching between a first mode and a second mode. The control unit 900 may be configured to alternate between the first mode and the second mode, for example. By repeatedly switching between the first mode and the second mode in a fixed cycle, moisture in the vehicle interior can be stably discharged to the outside of the vehicle. In particular, the vehicle interior dehumidifying system 2000 can continuously remove moisture by alternately switching between the first mode and the second mode, thereby solving the problem of not being able to remove moisture while the dehumidifying material is being regenerated.

[0127] The voltage applied to the first dehumidifying device 100A and the second dehumidifying device 100B can be switched on and off by, for example, electrically connecting the battery 200 to a pair of terminals (first terminal 111a and second terminal 111b) of the first dehumidifying device 100A (second dehumidifying device 100B) with an electric wire 810 and operating a power switch 910 provided midway along the wire. The control unit 900 can operate the power switch 910.

[0128] The ventilator 600 can be switched on and off by, for example, electrically connecting the control unit 900 and the ventilator 600 via an electric wire 820 or wirelessly and operating a switch (not shown) of the ventilator 600 with the control unit 900. The ventilator 600 can also be configured so that the ventilation volume can be changed by the control unit 900.

[0129] The switching of the switching valves 300A, 300B, and 300C can be achieved, for example, by electrically connecting the control unit 900 to the switching valves 300A, 300B, and 300C via an electric wire 830 or wirelessly, and operating the switches (not shown) of the switching valves 300A, 300B, and 300C using the control unit 900.

[0130] The switching valves 300A, 300B, and 300C are not particularly limited as long as they are electrically driven valves having the function of switching flow paths, and examples thereof include solenoid valves and motor-operated valves. In one aspect, the switching valves 300A, 300B, and 300C include an opening / closing door 312 supported on a rotating shaft 310, and an actuator 314 such as a motor that rotates the rotating shaft 310. The actuator 314 is configured to be controllable by the control unit 900.

[0131] In order to stably ensure the above-mentioned functions, it is desirable that the first dehumidifying device 100A and the second dehumidifying device 100B be located close to the vehicle cabin in the vehicle cabin dehumidifying system 2000. Therefore, from the viewpoint of preventing electric shock, the driving voltage is preferably 60 V or less. The honeycomb structures used in the first dehumidifying device 100A and the second dehumidifying device 100B have low electrical resistance at room temperature, so the honeycomb structures can be heated at this low driving voltage. The lower limit of the driving voltage is not particularly limited, but is preferably 10 V or more. If the driving voltage is less than 10 V, the current required to heat the honeycomb structure increases, and therefore the electric wire 810 must be thick. Therefore, the driving voltage of the vehicle cabin dehumidifying system 2000 can be, for example, 10 V or more and 60 V or less.

[0132] 6, the fan 600 is installed upstream of the first dehumidifying device 100A and the second dehumidifying device 100B. More specifically, the fan 600 is installed in the middle of the inlet pipe 400, and the air that has passed through the fan 600 flows into the first dehumidifying device 100A and the second dehumidifying device 100B in a forced manner. Alternatively, the fan 600 may be installed downstream of the first dehumidifying device 100A and the second dehumidifying device 100B. In this case, the fan 600 may be installed, for example, in the middle of the outlet pipes 500A and 500B, and the air that has passed through the inlet pipe 400 flows into the first dehumidifying device 100A and the second dehumidifying device 100B in a drawn manner. [Explanation of symbols]

[0133] 100 Dehumidifying Device 101 Peripheral wall 102 Bulkhead 103a First end surface 103b Second end face 104 cells 110a 1st electrode 110b 2nd electrode 111a 1st terminal 111b 2nd terminal 112a First current-carrying part 112b Second current-carrying part 120 Dehumidifying material containing layer 200 battery 300, 300A, 300B, 300C switching valve 310 Rotational Axis 312 Opening and Closing Doors 314 Actuator 400 Inlet piping 400A First inflow pipe 400B Second inflow pipe 500, 500A, 500B Outlet piping 500a, 500c First Route 500b, 500d Second Route 600 Ventilator 810,820,830 Electric wire 900 control section 910 Power Switch 1000,2000 Vehicle compartment dehumidification system

Claims

1. a honeycomb structure including an outer peripheral wall and partition walls disposed inside the outer peripheral wall to define a plurality of cells that become flow paths extending from a first end face to a second end face, the partition walls and the outer peripheral wall being made of a material having PTC characteristics; and a heater element including a pair of electrodes provided on the honeycomb structure; a dehumidifying material-containing layer provided on the surface of the partition wall and containing a dehumidifying material having a water release temperature of 30 to 70°C; A dehumidifying device comprising:

2. The dehumidifying device according to claim 1, wherein the material having PTC properties has a Curie point of 30 to 70°C.

3. 3. The dehumidifying device according to claim 2, wherein the temperature difference between the water release temperature of the dehumidifying material and the Curie point of the material having PTC properties is within ±10°C.

4. The dehumidifying material is one or more selected from aluminosilicate, silica gel, silica, graphene oxide, polymer adsorbent, polystyrene sulfonic acid, and metal organic framework. The dehumidifying device according to any one of claims 1 to 3.

5. The dehumidifying device according to any one of claims 1 to 3, wherein the material having PTC properties is mainly composed of barium titanate.

6. The barium titanate has the following [i] to [iii]: [i] (Ba 1-x-y Sr x A y ) TiO 3 (wherein A represents one or more rare earth elements, x is 0.15 to 0.25, and y is 0.0001 to 0.01) [ii] (Ba 1-x-y Sn x A y ) TiO 3 (wherein A represents one or more rare earth elements, x is 0.05 to 0.15, and y is 0.0001 to 0.01) [iii] (Ba 1-x-y Zr x A y ) TiO 3 (wherein A represents one or more rare earth elements, x is 0.12 to 0.18, and y is 0.0001 to 0.01) The dehumidifying device according to claim 5, wherein the dehumidifying agent is one or more selected from the group consisting of:

7. The dehumidifying device according to any one of claims 1 to 3, wherein the dehumidifying material-containing layer further contains an antibacterial material.

8. The dehumidifying device according to claim 7 , wherein the antibacterial material is at least one selected from the group consisting of a visible light responsive photocatalyst, silver, copper, and zinc.

9. The dehumidifying device according to any one of claims 1 to 3, wherein a pair of the electrodes are provided on the first end surface and the second end surface.

10. The dehumidifying device of claim 9 , further comprising terminals connected to the pair of electrodes.

11. a honeycomb structure including an outer peripheral wall and partition walls disposed inside the outer peripheral wall to define a plurality of cells that serve as flow paths extending from a first end face to a second end face, the partition walls and the outer peripheral wall being made of a material having PTC characteristics; and a pair of electrodes provided on the honeycomb structure; The material having PTC properties is a heater element for a dehumidifying device having a Curie point of 30 to 70°C.

12. 12. The heating element for a dehumidifying device according to claim 11, wherein the material having PTC properties is based on barium titanate.

13. The barium titanate has the following [i] to [iii]: [i] (Ba 1-x-y Sr x A y ) TiO 3 (wherein A represents one or more rare earth elements, x is 0.15 to 0.25, and y is 0.0001 to 0.01) [ii] (Ba 1-x-y Sn x A y ) TiO 3 (wherein A represents one or more rare earth elements, x is 0.05 to 0.15, and y is 0.0001 to 0.01) [iii] (Ba 1-x-y Zr x A y ) TiO 3 (wherein A represents one or more rare earth elements, x is 0.12 to 0.18, and y is 0.0001 to 0.01) The heater element for a dehumidifying device according to claim 12, wherein the heating element is one or more selected from the following:

14. A dehumidifying device according to any one of claims 1 to 3; a battery capable of applying a voltage to the dehumidifying device; an inlet pipe communicating the vehicle compartment with an inlet of the dehumidifying device; an outflow pipe communicating an outlet of the dehumidifying device with the vehicle interior and the outside of the vehicle; a switching valve provided in the outflow pipe, which can switch the flow of air passing through the outflow pipe to the vehicle compartment or to the outside of the vehicle; A vehicle interior dehumidification system.

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