JP4791566B2 - Wire heat source - Google Patents

Description

  The present invention relates to a linear heat source, and more particularly to a linear heat source using carbon nanotubes.

  Heat sources play an important role in areas such as people's life and scientific research. For example, it is applied to an electric heater, an electric heater, an infrared therapy device, and the like.

  FIG. 1 shows a linear heat source 10 in the prior art. The linear heat source 10 includes a cylindrical support 102, a heating element 104, a protective layer 106, two electrodes 110, and two fixing elements 108. The heating element 104 is installed on the surface of the support 102. The protective layer 106 is disposed on the surface of the heating element 104. The two electrodes 110 are respectively installed at both ends of the support 102 and are electrically connected to the heating element 104. The two fixing elements 108 fix the two electrodes 110 and the heating element 104 to both ends of the support 102, respectively. The heating element 104 is carbon fiber paper, and the carbon fiber paper includes a paper base material and asphalt group carbon fibers randomly distributed on the paper base material. The paper base is a mixture of cellulose fibers and resin. The carbon fiber paper wraps around or covers the support 102. When a current is passed through the heating element 104 by the two electrodes 110, heat is released from the heating element.

Kaili Jiang, Quung Li, Shuushan Fan, “Spinning continuous carbon nanotube yarns”, Nature, 2002, vol. 419, p. 801

  However, since the carbon fiber paper is thick and generally several tens of micrometers, the linear heat source 10 is difficult to manufacture an extremely small structure and cannot be applied to heating an extremely small heating object. There is. Since the carbon fiber paper includes a paper base, the density and weight of the carbon fiber paper is large, which is inconvenient for application of the linear heat source. Asphalt-based carbon fibers in the carbon fiber paper are randomly distributed, the carbon fiber paper has the disadvantages that it has poor strength, poor toughness, easily breaks, and limits the range of application. . The carbon fiber paper has a drawback that the efficiency of converting electric energy into heat energy is low, and energy is wasted.

  Therefore, an object of the present invention is to provide a linear heat source and a method for manufacturing the linear heat source.

  The linear heat source includes a linear support, a heating element installed on the linear support, and two electrodes electrically connected to the heating element, and the heating element has a carbon nanotube structure. And the carbon nanotube structure includes a plurality of carbon nanotubes.

  In the carbon nanotube structure, the plurality of carbon nanotubes are connected by an intermolecular force and are uniformly distributed.

  In the carbon nanotube structure, the carbon nanotubes are aligned and arranged.

  In the carbon nanotube structure, the carbon nanotubes are arranged without being oriented.

  The carbon nanotube structure includes at least one carbon nanotube film, at least one carbon nanotube linear structure, or a composite structure of a carbon nanotube film and a carbon nanotube linear structure.

  A reflective layer is installed between the heating element and the linear support, and the reflective layer is used to reflect the heat released from the heating element.

Compared with the conventional linear heat source, in the linear heat source of the present invention, the heating element includes a carbon nanotube structure, and the carbon nanotube structure includes a plurality of carbon nanotubes. Since the plurality of carbon nanotubes are uniformly arranged and the heating element has a uniform thickness and resistance, the heating element can uniformly dissipate heat and convert electrical energy into thermal energy. The efficiency is high, and the heat capacity of the unit area of the carbon nanotube structure is 2 × 10 ⁻⁴ J / cm ² K or less. Therefore, the linear heat source has a high temperature rising rate, a high thermal response speed, and a high heat exchange rate.

The definitive the heating element the carbon nanotubes have excellent mechanical properties, because it has excellent toughness and good mechanical strength, the heating element has excellent mechanical properties, has excellent toughness and mechanical strength, service life is long Become. Furthermore, a flexible linear heat source can be manufactured using the heating element.

Since the diameter of the definitive carbon nanotubes to the heating element is small, the heating element has a small thickness. Therefore, it is possible to manufacture an extremely small linear heat source, and it is possible to heat an element that is a small heating target by using the small linear heat source.

It is a figure which shows the structure of the linear heat source which concerns on a prior art. It is a figure which shows the structure of the linear heat source which concerns on the Example of this invention. It is sectional drawing cut | disconnected along the III-III line | wire shown in FIG. 2 of the linear heat source which concerns on the Example of this invention. It is sectional drawing cut | disconnected along the IV-IV line | wire shown in FIG. 3 of the linear heat source which concerns on the Example of this invention. It is a SEM photograph of the carbon nanotube film which consists of a carbon nanotube with which the end was connected in the line heat source concerning the example of the present invention. It is a figure which shows the structure of a carbon nanotube segment. It is a SEM photograph of the carbon nanotube film in which the carbon nanotubes in the line heat source concerning the example of the present invention are basically the same in length and arranged in parallel. 4 is an SEM photograph of a carbon nanotube film in which carbon nanotubes are arranged isotropically in a linear heat source according to an example of the present invention. It is a SEM photograph of the carbon nanotube film in which the carbon nanotube in the line heat source concerning the example of the present invention was arranged along the same direction. It is a photograph of the carbon nanotube film of a fluff structure in the line heat source concerning the example of the present invention. It is a SEM photograph of the carbon nanotube film of a fluff structure in the line heat source concerning the example of the present invention. It is the photograph of the carbon nanotube structure of the filtered fluff structure. It is the graph which measured the surface temperature of the carbon nanotube structure in the present Example 1 using a different surveying instrument at different work rates. It is a figure which shows the non-twisted carbon nanotube linear structure in the linear heat source which concerns on the Example of this invention. It is a figure which shows the twisted carbon nanotube linear structure in the linear heat source which concerns on the Example of this invention. It is a SEM photograph of the non-twisted carbon nanotube wire concerning the example of the present invention. It is a SEM photograph of the twisted carbon nanotube wire concerning the example of the present invention. It is a figure which shows the structure of the linear heat source which concerns on Example 2 of this invention. It is a figure which shows the structure of the linear heat source which concerns on Example 3 of this invention. It is a figure which shows the structure of the linear heat source which concerns on Example 4 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
2 to 4, the first embodiment of the present invention provides a linear heat source 20. The linear heat source 20 includes a linear support 202, a reflective layer 210, a heating element 204, a protective layer 208, and two electrodes 206.

  The reflective layer 210 is installed on the surface of the linear support 202. The heating element 204 is installed on the surface of the reflective layer 210. The two electrodes 206 are spaced apart and are electrically connected to the heating element 204, respectively. The protective layer 208 is disposed on the surface of the heating element 204. The linear heat source 20 is not limited in length and diameter, and the diameter is preferably 1.0 millimeter to 1.5 centimeter. In this embodiment, the linear heat source 20 has a diameter of 1.1 millimeters to 1.1 centimeters.

  The linear support 202 is used to support the heating element 204. The material of the linear support 202 may be, for example, a hard material such as ceramics, glass, resin, or quartz, or may be a soft material such as plastic or soft fiber. When the linear support 202 uses a soft material, the linear heat source 20 can be bent into an arbitrary shape. The linear support 202 is not limited in length and diameter, and can be selected according to actual application. In the present embodiment, the linear support 202 is a ceramic cylindrical body having a diameter of 0.5 millimeters to 1 centimeter.

  The reflective layer 210 reflects the heat emitted from the heating element 204 and emits the heat to the external space to increase the heating efficiency. The material of the reflective layer 210 is an insulating material such as a metal oxide, a metal salt, and ceramics. In this embodiment, the reflective layer 210 is an aluminum oxide film and has a thickness of 100 micrometers to 0.5 millimeters. The reflective layer 210 can be manufactured by a method such as physical vapor deposition or chemical vapor deposition. In this embodiment, aluminum oxide is deposited on the surface of the linear support 202 by a sputtering method to form the reflective layer 210. Of course, the reflective layer 210 may not be installed, that is, the heating element 204 may be installed directly on the surface of the linear support 202.

  The heating element 204 includes a carbon nanotube structure. The carbon nanotube structure is a self-supporting structure. The self-supporting structure means that the carbon nanotube structure is used independently without using a support. The carbon nanotube structure includes a plurality of carbon nanotubes, and the plurality of carbon nanotubes are connected by an intermolecular force and are uniformly distributed. In the carbon nanotube structure, the plurality of carbon nanotubes are arranged with or without orientation. According to the arrangement method of the plurality of carbon nanotubes, the carbon nanotube structure is classified into two types: a non-oriented carbon nanotube structure and an oriented carbon nanotube structure. In the non-oriented carbon nanotube structure in the present embodiment, the carbon nanotubes are arranged or entangled along different directions. In the oriented carbon nanotube structure, the plurality of carbon nanotubes are arranged along the same direction. Alternatively, in the oriented carbon nanotube structure, when the oriented carbon nanotube structure is divided into two or more regions, a plurality of carbon nanotubes in each region are arranged along the same direction. In this case, the arrangement directions of the carbon nanotubes in different regions are different. The carbon nanotube is a single-walled carbon nanotube, a double-walled carbon nanotube, or a multi-walled carbon nanotube. When the carbon nanotube is a single-walled carbon nanotube, the diameter is set to 0.5 to 50 nanometers, and when the carbon nanotube is a double-walled carbon nanotube, the diameter is set to 1 to 50 nanometers. When the carbon nanotube is a multi-walled carbon nanotube, the diameter is set to 1.5 to 50 nanometers.

The carbon nanotube structure is not limited in length, width and thickness, and can be manufactured according to actual application. The carbon nanotube structure of the present invention has a length of 1 centimeter to 10 centimeters, a width of 1 centimeter to 10 centimeters, a thickness of 0.5 nanometers to 2.0 millimeters, It is preferable that it is 0.01 micrometer-1.0 millimeter. The thermal response speed of the carbon nanotube structure is related to the thickness of the carbon nanotube structure. When the carbon nanotube structures have the same surface area, the thermal response speed is slow if the thickness is large, and the thermal response speed is fast if the thickness is thin. The purity of the carbon nanotube structure is high, and the carbon nanotube structure has a large specific surface area (for example, 100 m ² / g or more). The carbon nanotube structure has a heat capacity per unit area of 0 (0 is not included) to 2 × 10 ⁻⁴ J / cm ² · K, but preferably 0 (0 is not included) to 1.7. × 10 ⁻⁶ J / cm ² · K. When the thickness of the carbon nanotube structure is 1.0 micrometer to 1.0 millimeter, the carbon nanotube structure can reach the maximum temperature in a time of 1 second or less. The object to be heated can be quickly heated.

(1) The carbon nanotube structure includes at least one carbon nanotube film 143a shown in FIG. The carbon nanotube film 143a is obtained by pulling out from a super aligned carbon nanotube array (see Superaligned array of carbon nanotubes, Non-Patent Document 1). In the single carbon nanotube film 143a, the ends of the plurality of carbon nanotubes are connected along the same direction. That is, the single carbon nanotube film 143a includes a plurality of carbon nanotubes whose end portions in the length direction are connected to each other by intermolecular force. Referring to FIG. 6, the single carbon nanotube film 143a includes a plurality of carbon nanotube segments 143b. The plurality of carbon nanotube segments 143b are connected to each other by an intermolecular force along the length direction. Each carbon nanotube segment 143b includes a plurality of carbon nanotubes 145 connected in parallel to each other by intermolecular force. In the single carbon nanotube segment 143b, the plurality of carbon nanotubes 145 have the same length. By soaking the carbon nanotube film 143a in an organic solvent, the toughness and mechanical strength of the carbon nanotube film 143a can be increased. When the thickness of the carbon nanotube film 143a is 10 micrometers or less, the transmissivity of the carbon nanotube film 143a reaches about 96% or more, and therefore it can be used as a transparent heat source. The heat capacity per unit area of the single carbon nanotube film 143a is 1.7 × 10 ⁻⁶ J / cm ² · K or less.

  The carbon nanotube structure may include a plurality of stacked carbon nanotube films 143a. In this case, the adjacent carbon nanotube films 143a are bonded by intermolecular force. The carbon nanotubes 145 in the adjacent carbon nanotube films 143a intersect each other at an angle of 0 ° to 90 °. When the carbon nanotubes 145 in the adjacent carbon nanotube films 143a intersect at an angle of 0 ° or more, a plurality of micropores are formed in the carbon nanotube structure. Alternatively, the plurality of carbon nanotube films 143a may be juxtaposed without gaps.

  The method for manufacturing the carbon nanotube film includes the following steps.

  In the first step, a carbon nanotube array is provided. The carbon nanotube array is a super aligned carbon nanotube array (see Superaligned array of carbon nanotubes, Non-Patent Document 1), and a chemical vapor deposition method is employed as a method of manufacturing the super aligned carbon nanotube array. The manufacturing method includes the following steps. In step (a), a flat substrate is provided, and the substrate is any one of a P-type silicon substrate, an N-type silicon substrate, and a silicon substrate on which an oxide layer is formed. In this embodiment, it is preferable to select a 4-inch silicon substrate. In step (b), a catalyst layer is uniformly formed on the surface of the substrate. The material of the catalyst layer is any one of iron, cobalt, nickel and two or more alloys thereof. In step (c), the substrate on which the catalyst layer has been formed is annealed with air at 700 ° C. to 900 ° C. for 30 minutes to 90 minutes. In step (d), the annealed substrate is placed in a reaction furnace, heated with a protective gas at a temperature of 500 ° C. to 740 ° C., and then a carbon-containing gas is introduced to react for 5 to 30 minutes. Thus, it is possible to grow a super aligned carbon nanotube array (Superaligned array of carbon nanotubes, Non-Patent Document 1). The carbon nanotube array has a height of 100 micrometers or more. The carbon nanotube array is composed of a plurality of carbon nanotubes that are parallel to each other and grow perpendicular to the substrate. Since the carbon nanotubes are long, the carbon nanotubes are partially entangled with each other. By controlling the growth conditions, the carbon nanotube array does not contain impurities such as amorphous carbon and remaining metal particles as a catalyst.

  In this embodiment, as the gas containing carbon, for example, active hydrocarbons such as acetylene, ethylene, and methane are selected, and it is preferable to select ethylene. The protective gas is nitrogen gas or inert gas, preferably argon gas.

  The carbon nanotube array provided by the present embodiment is not limited to being manufactured by the above manufacturing method, and may be manufactured by an arc discharge method or a laser evaporation method.

  In the second step, at least one carbon nanotube film is stretched from the carbon nanotube array. First, using a tool such as tweezers, a plurality of carbon nanotube ends are provided. For example, a plurality of carbon nanotube ends are used by using a tape having a certain width. Next, the plurality of carbon nanotubes are pulled out at a predetermined speed to form a continuous carbon nanotube film composed of a plurality of carbon nanotube bundles.

  In the step of pulling out the plurality of carbon nanotubes, when the plurality of carbon nanotubes are detached from the base material, the carbon nanotube bundles are joined to each other by an intermolecular force to form a continuous carbon nanotube film. .

  (2) The carbon nanotube structure includes at least one carbon nanotube film shown in FIG. The single carbon nanotube film includes a plurality of carbon nanotubes having substantially the same length. In the single carbon nanotube film, the plurality of carbon nanotubes are arranged in parallel along the same direction. The thickness of the single carbon nanotube film is 10 nanometers to 100 micrometers. The plurality of carbon nanotubes are arranged in parallel to the surfaces of the plurality of carbon nanotube films, and are arranged in parallel to each other. Adjacent carbon nanotubes are separated and installed at a predetermined distance. The distance is from 0 to 5 micrometers. When the distance is 0 micrometer, the adjacent carbon nanotubes are connected by intermolecular force. The length of each carbon nanotube in the carbon nanotube film is the same as the length of the carbon nanotube film. The length of the single said carbon nanotube is 1 centimeter or more, and it is preferable that they are 1 centimeter-30 centimeters. Further, each carbon nanotube has no nodules. In the present embodiment, the carbon nanotube film has a thickness of 10 micrometers. The length of the single carbon nanotube 145 is 10 centimeters.

  (3) The carbon nanotube structure includes at least one carbon nanotube film. The carbon nanotube film is shown in FIG. 8 or FIG. The plurality of carbon nanotubes in the single carbon nanotube film are arranged isotropically, arranged along a predetermined direction, or arranged along a plurality of different directions. The carbon nanotube film has a sheet-like self-supporting structure formed by pressing the carbon nanotube array by applying a predetermined pressure by using a pushing tool and depressing the carbon nanotube array with the pressure. is there. The arrangement direction of the carbon nanotubes in the carbon nanotube film is determined by the shape of the pushing device and the pushing direction of the carbon nanotube array.

  Referring to FIG. 8, the carbon nanotubes in a single carbon nanotube film are arranged without being oriented. The carbon nanotube film includes a plurality of carbon nanotubes arranged isotropically. Adjacent carbon nanotubes attract each other by intermolecular force and connect. The carbon nanotube structure has planar isotropy. The carbon nanotube film is formed by pressing the carbon nanotube array along a direction perpendicular to the substrate on which the carbon nanotube array is grown using a pressing device having a flat surface.

  Referring to FIG. 9, the carbon nanotubes in a single carbon nanotube film are aligned and arranged. The carbon nanotube film includes a plurality of carbon nanotubes arranged along the same direction. When the carbon nanotube array is simultaneously pressed along the same direction using a pressing device having a roller shape, a carbon nanotube film including carbon nanotubes arranged in the same direction is formed. In addition, when the carbon nanotube array is simultaneously pressed along different directions using a pressing device having a roller shape, a carbon nanotube film including carbon nanotubes arranged in a selective direction along the different directions Is formed.

  The degree of inclination of the carbon nanotubes in the carbon nanotube film is related to the pressure applied to the carbon nanotube array. The carbon nanotubes in the carbon nanotube film and the surface of the carbon nanotube film form an angle α, and the angle α is not less than 0 ° and not more than 15 °. Preferably, the carbon nanotubes in the carbon nanotube film are parallel to the surface of the carbon nanotube film. The greater the pressure, the greater the degree of tilt. The thickness of the carbon nanotube film is related to the height of the carbon nanotube array and the pressure applied to the carbon nanotube array. That is, as the height of the carbon nanotube array increases and the pressure applied to the carbon nanotube array decreases, the thickness of the carbon nanotube film increases. On the contrary, as the height of the carbon nanotube array becomes smaller and as the pressure applied to the carbon nanotube array becomes larger, the thickness of the carbon nanotube film becomes smaller.

  (4) The carbon nanotube structure includes at least one carbon nanotube film. Referring to FIGS. 10 and 11, in the single carbon nanotube film, a plurality of carbon nanotubes are entangled with each other and isotropically arranged. In the carbon nanotube structure, the plurality of carbon nanotubes are uniformly distributed. The plurality of carbon nanotubes are arranged without being oriented. The length of the single said carbon nanotube is 10 micrometers or more, and it is preferable in it being 200 micrometers-900 micrometers. The carbon nanotube structure is formed in the shape of a self-supporting thin film. Here, the self-supporting structure is a form in which the carbon nanotube structure can be used independently without using a support material. The plurality of carbon nanotubes are close to each other by intermolecular force and entangled with each other to form a carbon nanotube net. The plurality of carbon nanotubes are arranged without being oriented to form many minute holes. Here, the diameter of the single minute hole is 10 micrometers or less. Since the carbon nanotubes in the carbon nanotube structure are arranged so as to be entangled with each other, the carbon nanotube structure is excellent in flexibility and can be formed to be bent into an arbitrary shape. Depending on the application, the length and width of the carbon nanotube structure can be adjusted. The carbon nanotube structure has a thickness of 1.0 micrometer to 1.0 millimeter, preferably 100 micrometers.

  The method for producing the carbon nanotube film includes the following steps.

  In the first step, a carbon nanotube raw material is provided.

  The carbon nanotubes are peeled off from the substrate with a tool such as a knife to form a carbon nanotube raw material. The carbon nanotubes are intertwined with each other to some extent. In the raw material of the carbon nanotube, the carbon nanotube has a length of 10 micrometers or more, preferably 200 micrometers to 900 micrometers.

  In the second step, the carbon nanotube raw material is immersed in a solvent, and the carbon nanotube raw material is treated to form a fluffy carbon nanotube structure.

  After the carbon nanotube raw material is immersed in the solvent, the carbon nanotube is formed into a fluff structure by a method such as ultrasonic dispersion, high intensity stirring or vibration. The solvent is water or a volatile organic solvent. Treatment is performed for 10 to 30 minutes with respect to the solvent containing carbon nanotubes by an ultrasonic dispersion method. Since the carbon nanotube has a large specific surface area and a large intermolecular force is generated between the carbon nanotubes, the carbon nanotubes are entangled and formed into a fluff structure.

  In the third step, the solution containing the fluff structure carbon nanotube structure is filtered to take out the final fluff structure carbon nanotube structure.

  First, provide a funnel with filter paper. When the solvent containing the fluffy carbon nanotube structure is applied to the funnel on which the filter paper is placed and then left standing for a while to dry, the fluffy carbon nanotube structure is separated. Referring to FIG. 12, the carbon nanotubes in the carbon nanotube structure having the fluff structure are entangled with each other to form an irregular fluff structure.

  The separated fluff structure carbon nanotube structure is placed in a container, the fluff structure carbon nanotube structure is expanded into a predetermined shape, and a predetermined pressure is applied to the expanded fluff structure carbon nanotube structure, When the solvent remaining in the fluffy carbon nanotube structure is roasted or the solvent naturally evaporates, the fluffy carbon nanotube film shown in FIGS. 10 and 11 is formed.

  The thickness and surface density of the fluffy carbon nanotube film can be controlled by the area where the fluffy carbon nanotube structure is developed. That is, the fluff-structured carbon nanotube structure having a certain volume has a smaller thickness and areal density of the fluff-structured carbon nanotube film as the developed area increases.

  In addition, a carbon nanotube film having a fluff structure is formed using a microporous film and an air pump funnel. Specifically, a microporous membrane and an air pump funnel are provided, and the solvent containing the fluff-structured carbon nanotube structure is passed through the microporous membrane to the air pump funnel, and then extracted to the air pump funnel and dried. As a result, a carbon nanotube film having a fluff structure is formed. The microporous film has a smooth surface. In the microporous membrane, the diameter of a single micropore is 0.22 micrometers. Since the microporous membrane has a smooth surface, the carbon nanotube film can be easily peeled off from the microporous membrane. Furthermore, since air pressure is applied to the fluffy carbon nanotube film by using the air pump, a uniform fluffy carbon nanotube film can be formed.

  When the carbon nanotube structure includes only one carbon nanotube film, both ends of the carbon nanotube in the carbon nanotube film are electrically connected to the first electrode and the second electrode, respectively. When the carbon nanotube structure includes a plurality of stacked carbon nanotube films, an angle α formed by the carbon nanotubes between adjacent carbon nanotube films is 0 ° to 90 °. Both ends of the carbon nanotubes in the at least one carbon nanotube film are electrically connected to the first electrode and the second electrode, respectively.

  (5) The carbon nanotube structure includes one carbon nanotube film segment. All the carbon nanotubes in the segments of the carbon nanotube film are parallel to each other and arranged in parallel along a predetermined direction. In the segment of the carbon nanotube film, the length of at least one carbon nanotube is the same as the total length of the segment of the carbon nanotube film. Accordingly, one dimension of the carbon nanotube film segment is limited by the length of the carbon nanotube. The carbon nanotube structure may include a plurality of laminated carbon nanotube film segments. In this case, the adjacent segments of the carbon nanotube film are bonded by intermolecular force. The thickness of the segment of the carbon nanotube film is 0.5 nanometer to 100 micrometers.

  The two electrodes 206 are made of a conductive material, and are disposed on the same surface of the heating element 204 or both opposing surfaces of the heating element 204. The shape of the two electrodes 206 is not limited. The two electrodes 206 are conductive films when applied to a very small line heat source, and the thickness of the conductive film is 0.5 nanometer to 100 micrometers. The material of the conductive film is a metal, an alloy, an indium tin oxide (ITO) film, antimony tin oxide (ATO), a silver paste, a conductive polymer, or a carbon nanotube structure. The metal is aluminum, copper, tungsten, molybdenum, gold, titanium, neodymium, palladium, cesium, or the like. The alloy is an alloy of the metal. The carbon nanotube structure is at least one carbon nanotube film shown in FIG. 5 or at least one carbon nanotube film shown in FIG.

  When the two electrodes 206 are the carbon nanotube structure, the carbon nanotube structure has adhesiveness, and thus the two electrodes 206 may directly cover or wrap the surface of the reflective layer 210. it can. Alternatively, the two electrodes 206 may be bonded to the surface of the reflective layer 210 with a conductive adhesive. The two electrodes 206 are electrically connected to the heating element 204 and at the same time are well fixed to the surface of the heating element 204. In this embodiment, the two electrodes 206 are stacked carbon nanotube films 143a as shown in FIG. 5, and the carbon nanotubes in the adjacent carbon nanotube films 143a are arranged along the same direction. The two electrodes 206 are bonded to the surface of the reflective layer 210 with a silver paste.

  In this embodiment, the heating element 204 includes a stack of hundred carbon nanotube films 143a shown in FIG. Adjacent carbon nanotube films 143a are closely connected by intermolecular force. Referring to FIG. 6, each carbon nanotube film 143 a includes carbon nanotubes 145 connected at the ends and arranged along the same direction. In the heating element 204, the arrangement direction of the carbon nanotubes 145 in the adjacent carbon nanotube film 143a is vertical. Some of the carbon nanotubes are arranged in a direction from the first electrode 12 toward the second electrode 14. The heating element 204 has an area of 9 square centimeters, a length of 3 centimeters, a width of 3 centimeters, and a thickness of 50 micrometers. The heating element 204 covers the reflective layer 210 and the two electrodes 206 and is electrically connected to the two electrodes 206.

  The material of the protective layer 208 is an insulating material such as plastic, rubber and resin. The thickness of the protective layer 208 is not limited and can be selected according to the actual application. The protective layer 208 covers the surface of the heating element 204, allows the linear heat source 20 to be used in an insulated state, and can prevent dust from adhering to the heating element 204. Of course, the protective layer 208 may not be provided. In the present embodiment, the protective layer 208 is made of rubber and has a thickness of 0.5 millimeters to 2 millimeters, and is used to protect the heating element 204.

  When the two electrodes 206 of the linear heat source 20 are electrically connected to a power source (not shown) and a voltage is applied to the heating element 204 by the two electrodes 206, the carbon of the heating element 204 in the linear heat source 20 is used. The nanotube structure can emit an electromagnetic wave having a predetermined wavelength. The heating target may be installed in direct contact with the linear heat source 20 or at a predetermined distance from the linear heat source 20. The electromagnetic wave emitted from the carbon nanotube structure heats the object to be heated. By controlling the dimensions of the heating element 204 and the voltage applied to the heating element 204, the heat released from the heating element 204 can be controlled. When the voltage is constant, the wavelength of the electromagnetic wave emitted from the heating element 204 can be adjusted by changing the thickness of the heating element 204. That is, the thicker the heating element 204, the shorter the wavelength of the electromagnetic wave emitted from the heating element 204. When the thickness of the heating element 204 is constant, the wavelength of the electromagnetic wave emitted from the heating element 204 becomes shorter as the voltage applied to the heating element 204 increases. Accordingly, the linear heat source 20 can be easily controlled.

  When the linear heat source 20 of this embodiment is placed in an air atmosphere and a voltage of 10 V to 30 V is applied to the heating element 204 by the two electrodes 206, the temperature of the linear heat source 20 reaches 50 ° C to 500 ° C. When the temperature of the carbon nanotube structure is increased to 200 ° C. to 450 ° C., the heating element 204 can radiate heat. The heating element 204 is excellent in that the heat radiation is stable, the efficiency of heat release is high, and the amount of heat released is large.

  FIG. 13 is a graph obtained by measuring the surface temperature of the carbon nanotube structure in the present example using two different surveying instruments at different powers. The two surveying instruments are the infrared thermometer RAYTEK RAYNER IP-M and the infrared thermometer AZ-8859, respectively. Surveying shows that the surface temperature of the carbon nanotube structure reaches 370 ° C. when the heating power is 36 watts. The carbon nanotube structure has high efficiency in converting electric energy into heat energy.

  When the linear heat source 20 of this embodiment is placed in a vacuum apparatus and a voltage of 80 V to 150 V is applied to the heating element 204 by the two electrodes 206, the linear heat source 20 may emit an electromagnetic wave having a short wavelength. it can. The linear heat source 20 emits visible light such as red light and yellow light, and can form normal heat radiation. In this case, the temperature of the linear heat source 20 can reach about 1500 ° C. When the voltage applied to the linear heat source 20 is sufficiently strong, the linear heat source 20 can emit ultraviolet light.

  When the two electrodes 206 of the linear heat source 20 are electrically connected to a power source, the carbon nanotube structure of the heating element 204 in the linear heat source 20 can emit an electromagnetic wave having a predetermined wavelength. The heating target may be in direct contact with the linear heat source 20, or the heating target may be placed at a predetermined distance from the linear heat source 20. The object to be heated is heated by electromagnetic waves emitted from the carbon nanotube structure.

(Example 2)
This embodiment provides a linear heat source. The linear heat source of the present embodiment is basically the same as the structure of the linear heat source 20 of the first embodiment. The difference is that the heating element includes a carbon nanotube structure including a plurality of carbon nanotube linear structures.

The carbon nanotube structure includes at least one carbon nanotube linear structure. The carbon nanotube linear structure includes at least one carbon nanotube wire. The heat capacity of one carbon nanotube wire is 2 × 10 ⁻⁴ J / cm ² · K or less, preferably 0 (not including 0) to 5 × 10 ⁻⁵ J / cm ² · K. . The diameter of one carbon nanotube wire is 0.5 nanometer to 100 micrometers, and preferably 1.0 micrometer to 100 micrometers.

  When the carbon nanotube linear structure includes two or more carbon nanotube wires, the carbon nanotube wires are arranged in parallel to form a non-twisted carbon nanotube linear structure (as shown in FIG. 14) or Each carbon nanotube wire is spirally arranged to form a twisted carbon nanotube linear structure (as shown in FIG. 15). That is, referring to FIG. 14, the carbon nanotube wires 161 in the non-twisted carbon nanotube linear structure 160 are arranged along the longitudinal direction of the carbon nanotube linear structure 160. Referring to FIG. 15, the carbon nanotube wires 171 in the twisted carbon nanotube linear structure 170 are spirally arranged along the axial direction of the linear structure 170.

  The carbon nanotube wire 161 in the non-twisted carbon nanotube linear structure 160 and the carbon nanotube wire 171 in the twisted carbon nanotube linear structure 170 are respectively non-twisted carbon nanotube wires (as shown in FIG. 16). ) And twisted carbon nanotube wires (as shown in FIG. 17).

  The diameter of the carbon nanotube linear structure is 0.5 nanometer to 2 millimeters, and the size of the diameter is related to the number of the carbon nanotube wires and the diameter thereof. The larger the carbon nanotube wire diameter and the larger the number, the larger the diameter of the carbon nanotube linear structure. On the contrary, the smaller the carbon nanotube wire diameter and the smaller the number, the smaller the diameter of the carbon nanotube linear structure.

  Referring to FIG. 16, the non-twisted carbon nanotube wire is obtained by treating a carbon nanotube film drawn from a carbon nanotube array with an organic solvent. The non-twisted carbon nanotube wire includes a plurality of carbon nanotubes arranged along the longitudinal direction and connected end to end. In this case, one carbon nanotube wire includes a plurality of carbon nanotube segments (not shown) connected end to end. The carbon nanotube segments have the same length and width. Further, a plurality of carbon nanotubes having the same length are arranged in parallel in each of the carbon nanotube segments. The plurality of carbon nanotubes are arranged parallel to the central axis of the carbon nanotube wire. In this case, the diameter of one non-twisted carbon nanotube wire is 0.5 nanometer to 100 micrometers. Referring to FIG. 17, the non-twisted carbon nanotube wire can be twisted to form a twisted carbon nanotube wire. Here, the plurality of carbon nanotubes are arranged in a spiral shape around the central axis of the twisted carbon nanotube wire. In this case, the diameter of one twisted carbon nanotube wire is 0.5 nanometer to 100 micrometers.

  Since the carbon nanotubes in the carbon nanotube wire are oriented and arranged, the carbon nanotubes in the carbon nanotube linear structure made of the carbon nanotube wire are oriented and arranged.

  Further, the twisted carbon nanotube wire may be treated with a volatile organic solvent. Adjacent carbon nanotubes in the twisted carbon nanotube wire are tightly connected by intermolecular force due to the action of the surface force of the volatile organic solvent, so that the twisted carbon nanotube wire has a small diameter and specific surface area. It has a large density, excellent mechanical strength and excellent toughness.

  When the carbon nanotube structure includes one carbon nanotube linear structure, both ends of the carbon nanotube in the carbon nanotube linear structure are electrically connected to the electrode 206, respectively. When the carbon nanotube structure includes a plurality of carbon nanotube linear structures, the plurality of carbon nanotube linear structures are arranged in parallel or crossed. The crossing angle of the crossed carbon nanotube linear structure is not limited. The method of installing each of the carbon nanotube linear structures is not limited, and it may be ensured that a uniform heating element 204 can be formed.

  In this embodiment, referring to FIG. 18, the heating element 204 includes a plurality of twisted carbon nanotube linear structures 170 shown in FIG. 15, and each twisted carbon nanotube linear structure 170 has the linear shape. They are arranged parallel to the surface of the support 202. The twisted carbon nanotube linear structure 170 includes a plurality of twisted carbon nanotube wires 171 arranged spirally along the axial direction of the twisted carbon nanotube linear structure 170. The twisted carbon nanotube wire 171 includes a plurality of carbon nanotubes arranged in a spiral shape along the axial direction of the carbon nanotube wire 171.

  The two electrodes 206 may include the carbon nanotube linear structure. In this embodiment, the two electrodes 206 include a single carbon nanotube linear structure 160 shown in FIG. The carbon nanotube linear structure 160 includes a plurality of non-twisted carbon nanotube wires 161 arranged in parallel along the longitudinal direction of the linear structure 160. The non-twisted carbon nanotube wire 161 includes a plurality of carbon nanotubes arranged along the longitudinal direction and connected end to end.

  Of course, the two electrodes 206 of Example 1 may include the carbon nanotube linear structure.

(Example 3)
Referring to FIG. 19, a line heat source according to Embodiment 3 of the present invention is provided. The linear heat source is basically the same as the structure of the linear heat source 20 of the first embodiment. The difference is that the heating element includes a plurality of carbon nanotube linear structures, and the plurality of carbon nanotube linear structures are arranged in an intersecting manner. For example, some of the plurality of carbon nanotube linear structures are arranged in parallel and are electrically connected to the two electrodes 206, and another part of the plurality of carbon nanotube linear structures includes the two electrodes 206. The carbon nanotube linear structures electrically connected to each other are vertically arranged. The carbon nanotube linear structure is a non-twisted carbon nanotube linear structure (as shown in FIG. 14) or a twisted carbon nanotube wire (as shown in FIG. 15).

Example 4
Referring to FIG. 20, a linear heat source according to Example 4 of the present invention is provided. The linear heat source is basically the same as the structure of the linear heat source 20 of the first embodiment. The difference is that the heating element includes a single carbon nanotube linear structure, and the carbon nanotube linear structure is wound around the surface of the reflective layer 210 disposed on the linear support 202, Both ends of the linear structure are electrically connected to the two electrodes 206, respectively. The carbon nanotube linear structure is a non-twisted carbon nanotube linear structure (as shown in FIG. 14) or a twisted carbon nanotube linear structure (as shown in FIG. 15). The carbon nanotube linear structure may include only one carbon nanotube wire.

  The carbon nanotube structure may be a composite structure of a carbon nanotube film and a carbon nanotube linear structure. The carbon nanotube linear structure is installed on the carbon nanotube film to form a heating element 204.

In the linear heat source, the heating element includes a carbon nanotube structure, the carbon nanotubes in the carbon nanotube structure are uniformly arranged, and the heating element has a uniform thickness and resistance. Heat can be released, and the efficiency of converting electric energy into heat energy is high, and the heat capacity of the unit area of the carbon nanotube structure is 2 × 10 ⁻⁴ J / cm ² K or less. Therefore, the linear heat source has a high temperature rising rate, a high thermal response speed, and a high heat exchange rate.

The definitive the heating element the carbon nanotubes have excellent mechanical properties, because it has excellent toughness and good mechanical strength, the heating element has excellent mechanical properties, has excellent toughness and mechanical strength, service life is long Become. Furthermore, a flexible linear heat source can be manufactured using the heating element.

Since the diameter of the definitive carbon nanotubes to the heating element is small, the heating element has a small thickness. Therefore, it is possible to manufacture an extremely small linear heat source, and it is possible to heat an element that is a small heating target by using the small linear heat source.

  The present invention provides a method for manufacturing the linear heat source. Specifically, referring to FIGS. 2 to 4, the method for manufacturing the linear heat source 20 of the first embodiment will be described in detail as an example.

  In the first step, a linear support 202 is provided.

  A linear support 202 is provided. The linear support 202 is used to support the heating element 204. The material of the linear support 202 may be, for example, a hard material such as ceramics, glass, resin, or quartz, or may be a flexible material such as plastic or flexible fiber. When a flexible material is used as the linear support 202, the linear heat source 20 can be curved into an arbitrary shape. The linear support 202 is not limited in length and diameter, and can be selected according to actual application. In this embodiment, the linear support 202 is a ceramic cylinder and has a diameter of 1 centimeter.

  In the second step, a reflective layer 210 is formed on the surface of the linear support 202.

  A reflective layer 210 is formed on the surface of the linear support 202 by a coating or coating method. The material of the reflective layer 210 is an insulating material such as a metal oxide, a metal salt, and ceramics. In this embodiment, the reflective layer 210 is an aluminum oxide film and has a thickness of 100 micrometers to 0.5 millimeters. The reflective layer 210 reflects heat released from the carbon nanotube structure and releases the heat to an external space. Of course, the heating element 204 may be directly installed on the surface of the linear support 202 without providing the reflective layer 210. That is, the manufacturing method of the linear heat source 20 may not include the second step.

  In the third step, a carbon nanotube structure is provided.

  The structure of the carbon nanotube structure and the manufacturing method thereof are the above-described structure of the carbon nanotube structure and the manufacturing method thereof.

  In the fourth step, two electrodes 206 are provided, and the two electrodes 206 are disposed on the reflective layer at an interval.

  The two electrodes 206 are conductive films or lead wires. The material of the conductive film is a metal, an alloy, an indium tin oxide (ITO) film, an antimony tin oxide (ATO), a silver paste, a conductive polymer, or a carbon nanotube structure. The metal is aluminum, copper, tungsten, molybdenum, gold, titanium, neodymium, palladium, cesium, or the like. The alloy is an alloy of the metal. The carbon nanotube structure is at least one carbon nanotube film or carbon nanotube linear structure shown in FIG. 1 or FIG. 7, for example, the carbon nanotube linear structure is the carbon nanotube shown in FIG. 14 or FIG. It is a linear structure.

  When the two electrodes 206 are the carbon nanotube structure, the two electrodes 206 can be bonded to the surface of the reflective layer 210 using the adhesiveness of the carbon nanotube structure itself. Alternatively, the two electrodes 206 can be bonded to the surface of the heating element 204 using a conductive adhesive. When the two electrodes 206 are other than the carbon nanotube structure, the two electrodes 206 are bonded to the surface of the reflective layer 210 using a conductive adhesive.

  In this embodiment, the two electrodes 206 include a plurality of laminated carbon nanotube films 143a as shown in FIG. 5, and the carbon nanotubes in adjacent carbon nanotube films 143a are arranged along the same direction. The direction made is parallel to the longitudinal direction of the linear support 202. The two electrodes 206 are bonded to the surface of the reflective layer 210 with a silver paste.

  In the fifth step, the carbon nanotube structure is placed on the surfaces of the reflective layer 210 and the two electrodes 206 to form the heating element 204.

  Since the carbon nanotube structure has adhesiveness, the carbon nanotube structure can be directly coated or wound on the surfaces of the reflective layer 210 and the two electrodes 206. Alternatively, the carbon nanotube structure may be adhered to the surfaces of the reflective layer 210 and the two electrodes 206 with a conductive adhesive. The conductive adhesive is a silver paste. When the linear heat source 20 does not include the reflective layer 210, the carbon nanotube structure is installed on the surface of the linear support 202.

  The method of installing the carbon nanotube structure is related to the structure of the carbon nanotube structure. In this example, the carbon nanotube structure is a stack of hundred carbon nanotube films 143a shown in FIG. The carbon nanotubes in the adjacent carbon nanotube film 143a intersect at an angle of 90 °. The surface of the reflective layer 210 and the two electrodes 206 is coated with the carbon nanotube structure using the adhesiveness of the carbon nanotube structure itself.

  In the sixth step, a protective layer 208 is formed on the surface of the heating element 204.

  The material of the protective layer 208 is an insulating material such as plastic, rubber and resin. The thickness of the protective layer 208 is not limited and can be selected according to the actual application. The protective layer 208 covers the surface of the heating element 204, allows the linear heat source 20 to be used in an insulated state, and can prevent dust from adhering to the heating element 204. In the present embodiment, the protective layer 208 is made of rubber and has a thickness of 0.5 millimeters to 2 millimeters, and is used to protect the heating element 204. Of course, the protective layer 208 may not be provided. That is, the method for manufacturing the linear heat source 20 may not include the sixth step.

  The method of manufacturing the linear heat source is simple, reduces cost, and can manufacture an extremely small linear heat source.

10, 20 Wire heat source 102, 202 Support 104, 204 Heating element 106, 208 Protective layer
108 Fixed element 110, 206 Electrode 210 Reflective layer 143a Carbon nanotube film 143b Carbon nanotube segment 145 Carbon nanotube 160 Non-twisted carbon nanotube linear structure 170 Twisted carbon nanotube linear structure 161, 171 Carbon nanotube wire

Claims (3)

A linear support, a heating element coated on the outer surface so as to wrap the linear support, and two electrodes electrically connected to the heating element,
The heating element includes a carbon nanotube structure;
The carbon nanotube structure includes at least one carbon nanotube linear structure, the carbon nanotube linear structure includes at least one carbon nanotube wire, and the carbon nanotube wire is connected end to end. A linear heat source comprising a plurality of carbon nanotubes .   The linear heat source according to claim 1, wherein the linear support is cylindrical. A reflective layer is installed between the heating element and the linear support;
The linear heat source according to claim 1, wherein the reflective layer is used to reflect heat released from the heating element.