JP2020112326A - Wick for heat radiation - Google Patents

Abstract

To provide a wick for heat radiation excellent in a hydrophilic property and having a high thermal transport coefficient.SOLUTION: A wick for heat radiation is composed of a fiber containing porous body in which a carbonaceous porous body is filled in at least a part of a fiber structure including carbon fibers and/or oxidized fibers, and has at least one peak in an area having a pore size of 10 μm or less in a pore size distribution of a the carbonaceous porous body.SELECTED DRAWING: Figure 3

Description

The present invention relates to a heat dissipation wick.

In recent years, many large-capacity secondary batteries have been used in electric devices, automobiles, and the like. With the increase in the capacity of these batteries, the influence of heat generated by charging and discharging on the performance of devices cannot be ignored. Therefore, there is a demand for a technique for efficiently removing heat from a heating element such as a battery or a processor. Further, due to the downsizing and high functionality of electronic devices, there is a demand for space-saving and efficient cooling technology.

The heat pipe has a heat transport function using latent heat due to evaporation in the vaporization part of the circulating fluid and condensation in the condensation part. More specifically, it has a structure in which a circulating fluid is enclosed in a space sealed by a peripheral wall, and has a heat transport function of moving latent heat at the time of phase change by repeating evaporation and condensation of the circulating fluid. In the vaporizing section that is a part that absorbs heat from the heat source, when the circulating fluid that has infiltrated the radiating wick takes heat from the peripheral wall and evaporates, the vaporizing section can be cooled to take latent heat. The evaporated circulating fluid is cooled from the outside through the peripheral wall in the condensing portion and is condensed into a liquid. This liquid is circulated because it is pushed out to the vaporization section by the pressure of the vapor, and heat can be continuously transported from the heating element.

In order to improve the heat transfer efficiency, it is necessary to efficiently evaporate the circulating fluid from the heat dissipation wick in the vaporization section. The heat dissipation wick has good liquid infiltration and discharge of evaporated vapor. Sex is required. Therefore, a technique for efficiently transporting the circulating fluid to the vaporization section by a capillary phenomenon between the inner surface of the peripheral wall and the wick surface has been studied. As such a technique, for example, in a flat heat pipe that transports heat by a working fluid (circulating fluid) that is heated to evaporate and radiates heat to condense, a container formed into a flat shape and having the working fluid sealed therein, A wick formed by mixing a large number of fine wires and powder, and the wick is fixed to one flat surface inside the container over the entire length of the container by sintering in a raised state. The flat heat pipe is configured so that the vaporized working fluid flows between the wick fixed to one of the flat surfaces and the other flat surface inside the container. (For example, refer to Patent Document 1) or a flat heat pipe that transports heat by a working fluid that is heated to evaporate and radiates heat to condense, and a container that is formed in a flat shape and in which the working fluid is sealed, A wick that produces a capillary force that causes the working fluid in the liquid phase to flow back to a position where it vaporizes, and the wick is fixed to one flat surface inside the container by sintering over the entire length in the longitudinal direction of the container. , The wick that is configured so that the working fluid in the vapor phase flows between the wick fixed to one of the flat surfaces and the other flat surface inside the container, and the wick that faces the other flat surface. A flat heat pipe (for example, refer to Patent Document 2) is proposed in which a groove portion that recirculates the working fluid in a liquid phase to a position where the working fluid is evaporated is formed along the longitudinal direction on the surface. There is.

JP, 2013-2640, A JP, 2014-115052, A

However, the techniques described in Patent Documents 1 and 2 directly heat and evaporate the circulating fluid in the liquid state by the heat transmitted through the peripheral wall, but the circulating fluid in the liquid state is generated by the generated steam. There is a problem in that the heat transport efficiency is insufficient, especially in an environment where a high heat load is applied, because the contact with the peripheral wall is hindered.

In view of the problems of the prior art, it is an object of the present invention to propose a heat dissipation wick having excellent hydrophilicity and a high heat transport coefficient in order to promote efficient infiltration and evaporation of a circulating fluid.

The present invention comprises a fiber-containing porous body in which at least a part of a fiber structure containing carbon fibers and/or oxidized fibers is filled with a carbonaceous porous body. It is a heat dissipation wick having at least one peak in a region of 10 μm or less.

Since the heat dissipation wick of the present invention is excellent in hydrophilicity and has a high heat transfer coefficient, the heat dissipation wick of the present invention can be used to provide a heat pipe having excellent heat transfer efficiency.

It is a schematic diagram showing an example of composition of a wick for heat dissipation of the present invention. It is a schematic diagram showing an example of the structure of a heat dissipation wick and a peripheral wall in a heat pipe using a heat dissipation wick of the present invention. It is a schematic diagram showing an example of a heat pipe using a wick for heat dissipation. It is a schematic diagram showing an example of pore size distribution of a carbonaceous porous body in a heat dissipation wick.

The heat dissipation wick of the present invention comprises a fiber-containing porous body in which at least a part of a fiber structure containing carbon fibers and/or oxidized fibers is filled with a carbonaceous porous body, and the pore diameter distribution of the carbonaceous porous body is In the above, at least one peak is present in a region having a pore diameter of 10 μm or less.

<Fiber-containing porous body>
The fiber-containing porous body according to the present invention has a structure in which at least a part of the fiber structure containing carbon fibers and/or oxidized fibers is filled with the carbonaceous porous body. By including carbon fibers and/or oxidized fibers, the hydrophilicity of the fiber-containing porous body can be improved. In addition, the fiber-containing porous body can be reinforced to improve the handleability in the production process.

The shape of the fibrous structure is not particularly limited as long as it contains carbon fibers and/or oxidized fibers, and examples thereof include forms such as a woven fabric, a papermaking body, and a nonwoven fabric. Examples of the fiber structure include carbon felt, carbon paper, carbon cloth, oxidized fiber felt, and fiber-containing foam. Among these, structures including carbon fibers such as carbon felt, carbon paper, and carbon cloth are preferable because they have excellent corrosion resistance. Further, in order to increase the hydrophilicity of the fiber structure, a structure containing oxidized fibers such as oxidized fiber felt, oxidized fiber paper, and oxidized fiber cloth is preferable.

The carbon fiber can be obtained by subjecting a resin fiber as a raw material to a heat treatment to form an oxidized fiber and then subjecting it to a graphitization treatment. As the resin fiber as a raw material of the carbon fiber, for example, acrylic fiber containing polyacrylonitrile, phenol fiber, polyamide fiber, polyimide fiber, industrial fiber such as pitch fiber, natural fiber such as cellulose fiber and chitin fiber can be used. .. Of these, polyacrylonitrile fiber is preferable in consideration of carbonization yield.

Examples of the oxidized fibers include those obtained by heat treating these resin fibers. The heat treatment of the resin fiber is preferably performed in an atmosphere containing oxygen such as air. The heat treatment temperature is preferably 150° C. or higher and 450° C. or lower, and the heat treatment time is preferably about several minutes. Oxidized fiber has many functional groups due to the elements derived from the raw materials, and can impart high hydrophilicity to the fiber.

The fiber-containing porous body in the present invention has a structure in which at least a part of the fiber structure is filled with a carbonaceous porous body. The carbonaceous porous body (1) has an action of infiltrating the circulating fluid in a liquid state by surface tension and transporting the liquid in the direction perpendicular to the surface of the wick for heat dissipation, and (2) having good adhesion to the peripheral wall, and the infiltrated circulation. It has the function of efficiently transferring heat to the fluid, and (3) the function of promoting evaporation of the circulating fluid due to the high surface area of the pores. In the present invention, it is preferable that at least one surface of the fibrous structure is internally filled or surface-coated with the carbonaceous porous body.

As a method of filling the carbonaceous porous body into the fibrous structure, for example, a precursor liquid in which carbon particles that are porous bodies are dispersed in a dispersion medium, or particles and carbon particles that disappear by heating are dispersed in a dispersion medium A method of impregnating the fibrous structure with a precursor liquid or the like and removing the dispersion medium can be mentioned. By the former method using the precursor liquid, a carbonaceous porous body composed of an aggregate of carbon particles in which voids between carbon particles form pores is filled. Further, by the latter method using the precursor liquid, the carbonaceous porous body having pores formed by the disappeared particles is filled in the aggregate of carbon particles.

As the carbon particles, for example, carbon black, carbon nanotubes, carbon nanofibers, chopped fibers of carbon fibers, graphene, graphite and the like can be used. You may use 2 or more types of these. For example, the pore size can be adjusted to a desired range by selecting the particle size, fiber length, aspect ratio, etc. of the carbon particles. In the pore size distribution of the carbonaceous porous material, in order to have at least one peak in the region where the pore size is 10 μm or less, it is preferable to use particles having a particle size of 30 μm or less and a large aspect ratio, such as acetylene black with a developed structure. It is preferable to use the above carbon black or carbon nanotube having a large aspect ratio.

In order to further improve the hydrophilicity of the fiber-containing porous body and to efficiently move the circulating fluid in the liquid state, the contact angle of water on the surface of the carbonaceous porous body is preferably 45 degrees or less, more preferably 10 degrees or less. .. Here, the contact angle of water on the surface of the carbonaceous porous body can be measured using a contact angle measuring device. More specifically, 10 μL of pure water was dropped on the surface of the carbonaceous porous body at 25° C., the contact angle after 1 second was measured at 5 points by the θ/2 method, and the average value was calculated to obtain the contact. You can find the corner.

As a method of reducing the contact angle of water on the surface of the carbonaceous porous body, for example, a method of reducing the pore size, a method of using a highly hydrophilic material, an oxidation treatment, a plasma treatment, an electrolytic treatment, or a hydrophilic material is used. Examples thereof include a method of applying hydrophilic treatment such as surface coating. For example, in the case of oxidation treatment, by sintering the carbonaceous porous body at a temperature of 200° C. to 600° C. in an oxygen-containing atmosphere such as the air, surface functional groups of the carbonaceous porous body are increased to improve hydrophilicity. Therefore, the contact angle of water can be 10 degrees or less.

In the fiber-containing porous body, the carbonaceous porous body is preferable because the smaller the pore size, the better the hydrophilicity and the easier the absorption of the circulating fluid in the liquid state. In the present invention, it is important for the pore size distribution of the carbonaceous porous material to have at least one peak in the region where the pore size is 10 μm or less, and to improve the permeation rate of the circulating fluid and improve the heat transport coefficient. You can By setting the pore diameter of the carbonaceous porous body to 10 μm or less, the surface tension is dramatically increased, and the circulating fluid in a liquid state can be rapidly taken into the pores. Therefore, the hydrophilicity and the heat transfer coefficient can be greatly improved. If only pores having a pore size of more than 10 μm are used, the hydrophilicity and the heat transport coefficient will be insufficient.

In order to further efficiently evaporate the circulating fluid and further improve the heat transport coefficient, in the pore size distribution of the carbonaceous porous body, the volume of pores having a pore size of 10 μm or less is 10% or more of the total pore volume. Is preferable, and 30% or more is more preferable. On the other hand, when moving the circulating fluid in a liquid state in the horizontal direction of the fiber-containing porous body, the carbonaceous porous body is formed only on one surface on the heat source side, and the volume of pores having a pore diameter of 10 μm or less is determined in the pore diameter distribution. The total pore volume is preferably 95% or less, more preferably 80% or less.

The pore size distribution and the pore volume of the carbonaceous porous material can be measured by a mercury porosimetry method in which mercury is pressure-injected into the pores to measure permeation, and for example, an automatic porosimeter “Autopore IV” manufactured by Shimadzu Corporation. 9500".

The volume ratio of the pores having a pore diameter of 10 μm or less in the pore size distribution of the carbonaceous porous body is adjusted to a desired range by adjusting the basis weight of the above-mentioned carbonaceous porous body to be filled in the fibrous structure, for example. be able to.

FIG. 4 shows a schematic view of an example of the pore size distribution of the carbonaceous porous material in the fiber-containing porous material (heat dissipation wick). In FIG. 4, the horizontal axis represents the pore diameter and the vertical axis represents the volume of the pores of each pore diameter. FIG. 4A is an example having one pore diameter peak 14 in the region of pore diameter of 10 μm or less in the pore diameter distribution, and this pore diameter peak 14 is a pore diameter peak 15 of 10 μm or less. FIG. 4B is an example having two pore diameter peaks in the pore diameter distribution, and among them, the peak existing in a region having a pore diameter of 10 μm or less is a pore diameter peak 15 having a pore diameter of 10 μm or less.

In order to further improve hydrophilicity and to efficiently move a circulating fluid in a liquid state, the fiber-containing porous body of the present invention preferably has a contact angle of water of 45 degrees or less on at least one surface. It is more preferably equal to or lower than 5 degrees, and further preferably equal to or lower than 5 degrees. Here, the contact angle of water on the surface of the fiber-containing porous body can be measured using a contact angle measuring device. More specifically, 10 μL of pure water was dropped on the surface of the fiber-containing porous body at 25° C., the contact angle after 1 second was measured at 5 points by the θ/2 method, and the average value was calculated to obtain the contact. You can find the corner. However, when pure water is absorbed inside the fiber-containing porous body, the hydrophilicity is very high, and when more than half of the pure water dropped within 1 second after dropping is absorbed inside the fiber-containing porous body, The contact angle is considered to be 5 degrees or less. The amount of pure water absorbed inside the fiber-containing porous body can be obtained by observing from the horizontal direction and from the difference between the amount of droplets existing on the surface and the amount of pure water dropped.

As a method for reducing the contact angle of water on the surface of the fiber-containing porous body, for example, a method using a carbonaceous porous body having a small pore size or a high hydrophilicity, an oxidation treatment, a plasma treatment, an electrolytic treatment, a hydrophilic treatment Examples of the method include a hydrophilic treatment such as surface coating with a conductive material. For example, in the case of an oxidation treatment, the fiber-containing porous body is sintered in an oxygen-containing atmosphere such as the air at a temperature of 200° C. to 600° C. to increase the surface functional groups of the fiber-containing porous body and improve the hydrophilicity. Therefore, the contact angle of water can be 10 degrees or less.

Of the surface of the fiber-containing porous body, the contact angle on the surface in contact with the peripheral wall close to the heat source is preferably smaller than the contact angle on the surface on the opposite side to prevent the circulating fluid from flowing in the perpendicular direction. Can be promoted more.

Next, a method for manufacturing the fiber-containing porous body will be described. Examples of the method for filling the carbonaceous porous body in the fibrous structure include wet coating and impregnation. More specifically, the carbonaceous porous body can be filled by preparing in advance a coating liquid in which carbon particles are dispersed in a liquid serving as a dispersion medium, and coating or impregnating the coating liquid on the fiber structure. The coating liquid may contain a surfactant, a binder resin, or the like, if necessary. By containing the surfactant, the carbon particles can be stably dispersed. By containing the binder resin, the carbon particles can be bound and the structure can be strengthened.

Examples of the coating method of the coating liquid include screen printing, rotary screen printing, spray spraying, intaglio printing, gravure printing, die coater coating, bar coater coating, blade coater coating, and roll knife coater coating. Die coater coating is preferable in order to precisely control the coating amount.

Examples of the method of impregnating the coating liquid include a method of impregnating the coating liquid in an impregnation tank and immersing the fiber structure in the impregnation tank to impregnate the inside of the fiber structure with the coating liquid.

After coating or impregnation, it is preferable to dry and remove the dispersion medium of the coating liquid. When the dispersion medium is water, the drying temperature is preferably room temperature (around 20° C.) to 200° C. or lower, and more preferably 60° C. or higher and 150° C. or lower.

Next, when the coating liquid contains a surfactant or a binder resin, sintering can be performed for the purpose of removing the surfactant and for carbonizing the binder resin to bind the carbon particles. The sintering temperature is preferably 200° C. or higher and 500° C. or lower, though it depends on the boiling point and decomposition temperature of the surfactant. By setting the sintering temperature to 200° C. or higher, the surfactant can be sufficiently removed. On the other hand, by setting the sintering temperature to 500° C. or lower, it is possible to suppress the disappearance of carbon fibers and oxidized fibers. In addition, it is preferable to perform the sintering in an atmosphere containing oxygen such as the air because the hydrophilicity can be improved. The sintering time is preferably as short as possible from the viewpoint of productivity. Specifically, it is preferably within 20 minutes, more preferably within 10 minutes, still more preferably within 5 minutes.

<Radiation wick>
The heat dissipation wick of the present invention comprises the fiber-containing porous body. FIG. 1 shows a schematic diagram of an example of the configuration of the heat dissipation wick. FIG. 1A is an example of a heat dissipation wick composed of a fiber-containing porous body having only a filling portion 1 in which the fiber structure is filled with a carbonaceous porous body, and FIG. FIG. 1(c) shows an example of a heat dissipation wick made of a fiber-containing porous body having a filling part 1 in which the fiber structure is filled with a carbonaceous porous body. It is an example of a heat dissipation wick composed of a fibrous structure having a filling part 1 filled with a porous material and a carbonaceous porous material 3. In the configuration of FIG. 1B, by having the fibrous structure 2 not filled with the carbonaceous porous body, the movement of the circulating fluid in the liquid state in the horizontal direction of the heat dissipation wick can be further promoted. .. Further, in the configuration of FIG. 1C, the presence of the carbonaceous porous body 3 makes it possible to smooth the surface, improve the adhesion to the peripheral wall, and further promote the evaporation of the circulating fluid.

<Circulating fluid>
The heat pipe has a structure in which a circulating fluid is enclosed in a space closed by a peripheral wall. Circulating fluid is a fluid that transports heat in the form of latent heat by being heated and vaporized, and then condensed by cooling. Examples of the circulating fluid include water, alcohols, ketones, ammonia, fluorine-based gas, carbon dioxide, nitrogen and the like. These are selected according to the operating temperature range of the heat pipe. A surfactant or the like can be included in order to adjust the viscosity and surface tension of these liquids.

<Peripheral wall>
The heat dissipation wick is arranged in the space sealed by the peripheral wall, and has a structure capable of holding the circulating liquid and its vapor therein. A part of the peripheral wall transfers the heat from the heat source to the enclosed space inside the peripheral wall, and the circulating liquid becomes vapor on the surface of the heat dissipation wick. For this reason, it is preferable that the peripheral wall has high heat conductivity and excellent chemical stability at high temperatures. As the peripheral wall, for example, metals such as copper, aluminum and stainless steel are preferably used.

FIG. 2 shows an example of the structure of the heat dissipation wick and the peripheral wall in the heat pipe using the heat dissipation wick of the present invention. FIG. 2A has a peripheral wall 5 having recesses 6 formed on both surfaces of the heat dissipation wick 4. Since the concave portion 6 of the peripheral wall can promote the horizontal movement of the vapor or liquid of the circulating fluid, the circulating fluid can be circulated more efficiently. FIG. 2B has peripheral walls 5 on both sides of the heat dissipation wick 4 having recesses 7 formed on both sides. Since the concave portion 7 of the heat dissipation wick can promote the horizontal movement of the vapor or liquid of the circulating fluid, the circulating fluid can be circulated more efficiently. Further, by making the vaporization section thin, it is possible to construct a heat pipe that can be mounted on small equipment.

<heat pipe>
FIG. 3 shows a schematic view of an example of a heat pipe using a heat dissipation wick. It is a structure of a loop heat pipe in which the circulating fluid moves in one direction, and the circulating fluid is sealed by the peripheral wall 5, and the heat dissipation wick 6 is arranged in the vaporization section 9 surrounded by the peripheral wall 5 in contact with the heat source 8. After the circulating fluid is vaporized in the vaporizing section 9, the circulating fluid is condensed into a liquid in the condenser section 10 in contact with the cooling fins 11 through the circulating fluid transport path 12. This liquid is supplied to the vaporization section 9 through the circulating fluid transportation path 13 and absorbed by the heat dissipation wick 6. By circulating the circulating fluid as the heat medium in this manner, high heat transport efficiency is exhibited.

Hereinafter, the present invention will be specifically described with reference to examples.

<Production Example 1: Fiber structure 1>
The oxidized fiber obtained by heat-treating the polyacrylonitrile fiber (diameter 10 μm) at 200° C. for 5 minutes was treated by the needle punching method to prepare an oxidized fiber felt having a basis weight of 750 g/m 2 and a thickness of 3.5 mm.

<Production Example 2: Fiber structure 2>
The oxidized fiber felt obtained in Production Example 1 was subjected to continuous graphitization treatment in nitrogen at 1500° C. for 15 minutes to prepare a carbon fiber felt having a basis weight of 300 g/m 2 and a thickness of 3 mm.

<Production Example 3: Coating liquid 1>
After mixing 3 parts by weight of nonionic surfactant Triton X100 (sold by: Sigma-Aldrich) with 100 parts by weight of pure water, carbon particles: acetylene black (manufactured by Denka Corporation: particle size 35 nm, aspect ratio: 1-2) 7 parts by weight and 1 part by weight of binder resin: PVA (polyvinyl alcohol) were added and further mixed to prepare a coating liquid 1.

<Production Example 4: Coating liquid 2>
Carbon particles: Production Example 3 except that carbon particles: VGCF-H (manufactured by Showa Denko KK: particle length 15 μm, aspect ratio: 50 to 200) were used instead of acetylene black (manufactured by Denka Corporation). A coating liquid 2 was prepared in the same manner.

The evaluation methods in each Example and Comparative Example are shown below.

<Production Example 5: Coating liquid 3>
Carbon particles: Coating liquid 2 was prepared in the same manner as in Production Example 3 except that carbon particles: ground graphite powder (particle size: 35 μm, aspect ratio: 2 to 5) were used instead of acetylene black (manufactured by Denka Corp.). It was made.

The evaluation methods in each Example and Comparative Example are shown below.

<Measurement of thickness>
The thicknesses of the fiber structures obtained in Production Examples 1 to 2 and the fiber-containing porous bodies obtained in each of the Examples and Comparative Examples were measured using a digital thickness meter “Digimicro” manufactured by Nikon Corporation. The measurement was performed while applying a load of 15 MPa.

<Calculation of pore size peak and volume ratio of pores having a pore size of 10 μm or less>
With respect to the fiber-containing porous bodies obtained in each of the examples and comparative examples, the pore size distribution and the pore volume were measured by the mercury porosimetry method using an automatic porosimeter “Autopore IV 9500” manufactured by Shimadzu Corporation. When a peak is observed in a region having a pore diameter of 10 μm or less in the pore diameter distribution, the peak position of the one having the maximum peak intensity is taken as the pore diameter peak. From the measurement results, the pore volume V ₍₀ to 10 ₎ of the pore diameter of 10 μm or less and the pore volume V ₍ 10 to _∞) of the pore diameter of larger than 10 μm in the fiber-containing porous body were obtained. The pore volume V _{(0 to 10)} /(V _{(10 to ∞)} +V ₍₀ to 10 ₎ ) was calculated as the ratio of the volume of pores having a pore diameter of 10 μm or less.

<Measurement of contact angle>
Using a contact angle meter DropMaster500 manufactured by Kyowa Interface Science Co., Ltd., 10 μL of pure water was dropped on the surface of the fiber-containing porous body obtained in each Example and Comparative Example, and the contact angle after 1 second was measured. .. However, the measurement surface was a surface filled with the carbonaceous porous body as a surface to be in contact with the heat source. The contact angle was measured at 5 points by the θ/2 method, and the average value was used as the contact angle.

<Evaluation of heat transport performance>
Both sides of the square fiber-containing porous body of 5 cm square (radiation wick) obtained in each of the Examples and Comparative Examples were sandwiched between the peripheral walls of a grooved stainless steel plate, and both sides of the radiating wick contacted the peripheral wall. Was produced. The end of the produced vaporizing section was connected to a condenser section adjusted to 50 by a circulating fluid transportation path made of stainless steel having an inner diameter of 1 mmφ. The temperature on the heat source side of the vaporization section is raised to 50° C. or higher, and the amount of heat transferred from the product of the temperature difference between the heat source and the vaporization section and the heat flux at a heat flux of 3 [W/cm ² ] after 100 hours is calculated. The heat transfer coefficient [W/m ² K] was calculated and divided by the wick area. Lack where heat transport coefficient of less than ^{1000 [W / m 2 K]} , 1000 [W / m 2 K] or 2000 [W / ^{m 2} K] of less than the case ^{good, 2000 [W / m 2 K} ] or more 3000 [W / ^{m 2} K] of less than very good case, was evaluated very good in the case of more than ^{3000 [W / m 2 K]} .

(Example 1)
The coating liquid 2 obtained in Production Example 4 was applied to a carbon fiber felt having a basis weight of 300 g/m ² and a thickness of 3 mm obtained in Production Example 1 so that the carbonaceous porous material had a basis weight of 50 g/m ^2. Coating, and dried in air at 140° C. for 30 minutes. Next, sintering was performed at 308° C. for 30 minutes in the air to obtain a fiber-containing porous body. The evaluation results are shown in Table 1.

(Example 2)
A fiber-containing porous body was obtained in the same manner as in Example 1 except that the coating liquid 2 obtained in Production Example 4 was applied so that the basis weight of the carbonaceous porous body was 130 g/m ² . The evaluation results are shown in Table 1.

(Example 3)
A fiber-containing porous body was obtained in the same manner as in Example 1 except that the coating liquid 2 obtained in Production Example 4 was applied so that the basis weight of the carbonaceous porous body was 300 g/m ² . The evaluation results are shown in Table 1.

(Example 4)
The coating liquid 1 obtained in Production Example 3 was applied to a carbon fiber felt having a basis weight of 300 g/m ² and a thickness of 3 mm obtained in Production Example 1 so that the carbonaceous porous material had a basis weight of 200 g/m ^2. Coating, and dried in air at 140° C. for 30 minutes. Next, sintering was performed in the atmosphere at 380° C. for 30 minutes to obtain a fiber-containing porous body. The evaluation results are shown in Table 1.

(Example 5)
The coating liquid 2 obtained in Production Example 4 was applied so that the basis weight of the carbonaceous porous material would be 130 g/m ² , dried in the air at 140° C. for 30 minutes, and then baked in the air at 250° C. for 30 minutes. A fiber-containing porous body was obtained in the same manner as in Example 1 except that the binding was performed. The evaluation results are shown in Table 1.

(Example 6)
The coating liquid 2 obtained in Production Example 4 was applied to the oxidized fiber felt having a basis weight of 750 g/m ² and a thickness of 3.5 mm obtained in Production Example 1 so that the carbonaceous porous material had a basis weight of 150 g/m ^2. It was applied using a die coater and dried in the atmosphere at 140° C. for 30 minutes. Next, sintering was performed at 350° C. for 30 minutes in the atmosphere to obtain a fiber-containing porous body. The evaluation results are shown in Table 1.

(Comparative Example 1)
The carbon fiber felt having a basis weight of 300 g/m ² and a thickness of 3 mm obtained in Production Example 2 was evaluated in the same manner as in Example 1. However, since it does not have a carbonaceous porous body, the pore size distribution was measured for the fiber-containing porous body. The evaluation results are shown in Table 1.

(Comparative example 2)
The oxidized fiber felt having a basis weight of 750 g/m ² and a thickness of 3.5 mm obtained in Production Example 1 was evaluated in the same manner as in Example 1. However, since it does not have a carbonaceous porous body, the pore size distribution was measured for the fiber-containing porous body. The evaluation results are shown in Table 1.

(Comparative example 3)
The coating liquid 3 obtained in Production Example 5 was applied so that the basis weight of the carbonaceous porous material was 130 g/m ² , dried in the air at 140° C. for 30 minutes, and then baked in the air at 250° C. for 30 minutes. A fiber-containing porous body was obtained in the same manner as in Example 1 except that the binding was performed. The evaluation results are shown in Table 1.

1: Filling part (fiber structure + carbonaceous porous body)
2: Fiber structure 3: Carbonaceous porous body 4: Heat dissipation wick (fiber-containing porous body)
5: peripheral wall 6: concave part of peripheral wall 7: concave part of heat dissipation wick 8: heat source 9: vaporization part 10: condensation part 11: cooling fins 12: circulating fluid transportation path (outward path)
13: Circulating fluid transportation path (return path)
14: Pore size peak 15: Pore size peak of 10 μm or less

Claims (3)

A fiber-containing porous body having a carbonaceous porous body filled in at least a part of a fiber structure containing carbon fibers and/or oxidized fibers, and having a pore diameter distribution of the carbonaceous porous body, the region having a pore diameter of 10 μm or less. A wick for heat dissipation that has at least one peak in. The wick for heat dissipation according to claim 1, wherein in the pore size distribution of the carbonaceous porous body, the volume of pores having a pore size of 10 μm or less is 30% or more of the total pore volume. The heat dissipation wick according to claim 1 or 2, wherein a contact angle of water on at least one surface of the fiber-containing porous body is 5 degrees or less.