JP5047366B2 - Carbon heating element and manufacturing method thereof - Google Patents

Description

  The present invention relates to a carbon heating element manufactured from a narrow woven carbon body obtained by physically braiding a plurality of carbon fiber yarns without using a synthetic resin solution. Since the heat treatment is performed in its original form without processing, the resistance characteristics and heat generation distribution are very uniform, and the synthetic resin solution that is regarded as an impurity itself is not used for the formation of the narrow-width woven carbon body, and the remaining impurities are removed. The present invention relates to a carbon heating element and a method for manufacturing the same, in which almost no impurities are generated by performing a high-temperature tertiary heat treatment for the purpose, and the life is greatly extended.

  A carbon yarn (carbon fiber yarn) heater manufactured using carbon fiber as a heating element is disclosed in US Patent No. 6,464,918, Japanese Patent Application Laid-Open No. 2000-272913, Russian Patent No. 2,149,215, Japan Japanese Patent Laid-Open No. 2000-123960, Japanese Patent Laid-Open No. 2002-63870, US Patent No. 6,534,904. However, these conventional patents mainly relate to theoretical techniques, have practical problems in producing a carbon yarn heater as a product, and have not yet reached the level of commercialization.

  In Korean Patent No. 10-0793973, a helical carbon fiber heating element is characterized in that carbon fiber is previously applied with a synthetic resin solution such as a phenol formaldehyde solution and heat treated. A manufacturing method has been disclosed.

  The method for producing the carbon fiber heating element will be described in detail with reference to FIG. 1. (a) Several carbon fiber yarns are arranged in parallel with a constant width (a1), and a helical shape with a constant pitch on the main shaft. (A2), (b) a clip for energization is attached to both ends of the helical carbon material, and (c) the surface of the carbon yarn of the helical carbon material. Is applied with a synthetic resin solution such as phenol formaldehyde, and (d) a current is applied to both contacts of the helical carbon material, and the carbon material is subjected to a primary heat treatment at a temperature and pressure at which the synthetic resin solution can be volatilized. Forming a shaped form, (e) removing the main shaft after cooling to separate the helical form, and (f) subjecting the helical form to a secondary heat treatment under a gas phase hydrocarbon atmosphere, Spiral carbon fiber heating element that generates heat when mounted on an infrared generator Manufacturing.

  However, in the above-described method for manufacturing a carbon fiber heating element, a step of applying a synthetic resin solution is indispensable in order to maintain several (for example, four) carbon yarns arranged in parallel at a constant width. . This synthetic resin solution application step is performed in step (c), and the applied synthetic resin solution forms a carbon fiber heating element by adhering carbon fiber yarns through subsequent steps (d) and (e). The excess synthetic resin solution remains in the form of carbon residue. When a carbon heater or an infrared generator is manufactured using the carbon fiber heating element in a state where carbon residue remains in the carbon fiber heating element, as shown in FIG. 2, the carbon residue is generated inside the infrared generator. There is a problem that it flows and eventually leads to a failure of the infrared generator.

  In addition, even if several carbon yarns are applied with a synthetic resin solution, the carbon fiber yarns are not evenly coated with each other due to uneven coating thickness or impact of the applied synthetic resin in a state where the carbon yarns are in parallel contact. If a gap as shown in FIG. 3 is formed, the resistance characteristics of the carbon fiber heating element become non-uniform due to the gap. As a result, the current flows excessively or too little for each part of the carbon fiber heating element, resulting in variations in the heat generation distribution, and as a result, the durability and quality of the carbon fiber heating element are lowered.

  In order to reduce the cause of the occurrence of such a gap in each carbon fiber yarn, as shown in FIG. 2, the energizing clip is twisted while twisting the carbon yarns at both ends of the spiral carbon material. It must be installed as a carbon fiber heating element. However, due to the twist of the carbon yarn at both ends of the carbon fiber heating element, as shown in FIG. 4, while the calorific value per unit area increases at the twisted portion T1 of the carbon yarn, the twist of the carbon yarn The heat generation amount per unit area is relatively reduced at the portion T2 where the heat generation is not performed, and variations in the heat generation distribution are generated in the carbon fiber heating element. However, the durability and quality of the carbon fiber heating element are lowered only by this variation. In particular, when the calorific value per unit area increases at the twisted portion T1 of the carbon yarn, the nickel plate holding the surface of the energizing clip is overheated and the nickel evaporates, and a nickel ring is formed on the inner surface of the infrared generator tube. However, as the thickness of such a nickel ring is increased, the pipe body is cracked, the appearance of the product is lowered, and the life is shortened.

  In addition, the phenol formaldehyde constituting the synthetic resin solution applied to the spiral carbon material is thermally decomposed to release air pollutants. In particular, since the synthetic resin solution contains a large amount of amorphous carbon that can be vaporized at 900 ° C. or lower in a gas phase hydrocarbon atmosphere, the synthetic resin solution is amorphous from the carbon fiber heating element produced using the synthetic resin solution. Carbonaceous materials and nickel-based metal components are vaporized, which may cause carbonization and blackening (nickel evaporation ring) on the inner surface of the infrared generator. This is the life of the carbon fiber heating element. Has the problem of having a fatal effect on

  Particularly, Korean Registered Patent Publication No. 10-0793973 discloses that the unit carbon fiber yarns are adjacently arranged and applied with a synthetic resin solution so as to adhere to each other to form a spiral form, The shaped product is subjected to primary and secondary heat treatments to produce a carbon fiber heating element in which impurities remain on the surface. Accordingly, when additional high-temperature heat treatment is performed to remove impurities remaining on the surface of the carbon fiber heating element, the carbon fiber yarn covered with the synthetic resin in the carbon fiber heating element may be broken, or even Since the phenomenon of cutting occurs, there is a fundamental defect that impurities cannot be removed by high-temperature heat treatment.

  Accordingly, an object of the present invention is to provide a resistance characteristic by heat-treating a narrow woven carbon body obtained by physically braiding a plurality of carbon fiber yarns without using a synthetic resin solution, without any other processing. In addition, the heat distribution can be made very uniform, and not only the synthetic resin solution is not used for the production of the narrow-width woven carbon body, but also the high temperature tertiary heat treatment is performed, so that almost no impurities are generated and the lifetime is increased. Is to provide a carbon heating element and a manufacturing method thereof.

  To achieve the above object, the present invention comprises a step of immersing a carbon fiber yarn in at least one lubricant selected from the group consisting of water, a surfactant and a silicon emulsion to form a lubricant-impregnated carbon fiber yarn. , A step of arranging 3 to 24 of the lubricant-impregnated carbon fiber yarns in one direction and braiding to form a narrow woven carbon body, and winding the narrow woven carbon body around the surface of the heat-resistant main shaft to form carbon. A step of forming a molded body, a step of attaching current-carrying clips to both ends of the carbon molded body, a current being applied to the current-carrying clips, and a primary heat treatment of the carbon molded body in a gas-phase hydrocarbon atmosphere. And a step of separating the heat-treated carbon molded body from the heat-resistant main shaft, applying a current to the current-carrying clip of the separated heat-treated carbon molded body, and under a gas phase hydrocarbon atmosphere. 1300 A secondary heat treatment is performed at 2500 ° C. to form a carbon film heating element having a carbon layer coating having a nanocrystalline structure deposited on the surface, and the carbon coating heating element is set to 2500 to 3500 ° C. in an inert gas or reduced-pressure atmosphere. And a third heat treatment to evaporate impurities and graphitize the remaining amorphous carbon.

  The present invention also includes a step of arranging 3 to 24 polyacrylonitrile yarns or viscose yarns in one direction and braiding them into a web-like narrow woven fabric, and the narrow woven fabric in an inert gas atmosphere. And carbonizing at 1,500 to 2,500 ° C. while stretching in the longitudinal direction to form a narrow woven carbon body, and winding the narrow woven carbon body around the surface of the heat-resistant main shaft to obtain a carbon molded body A step of attaching current-carrying clips to both ends of the carbon molded body, applying a current to the current-carrying clips, and subjecting the carbon molded body to a primary heat treatment in a gas-phase hydrocarbon atmosphere, and heat-treated carbon Forming a molded body; separating the heat-treated carbon molded body from the heat-resistant main spindle; and applying a current to the current-carrying clip of the separated heat-treated carbon molded body to generate 1300-2500 under a gas phase hydrocarbon atmosphere. 2 at ℃ A step of heat-treating a carbon film heating element having a carbon layer film having a nanocrystalline structure deposited on the surface, and a third heat treatment of the carbon film heating element at 2500 to 3500 ° C. in an inert gas or reduced-pressure atmosphere And a step of evaporating the impurities and graphitizing the remaining amorphous carbon.

  The carbon heating element produced according to the present invention is not energized in a thin woven carbon body that is obtained by physically braiding a plurality of carbon fiber yarns without using a synthetic resin solution. Since the primary clip, the secondary, and the tertiary heat treatment are performed, the resistance characteristics and the heat generation distribution become very uniform, and the durability and quality can be greatly improved.

  In addition, the carbon heating element of the present invention does not use the synthetic resin solution, which is regarded as an impurity itself, for the production of the narrow-width woven carbon body. Since the tertiary heat treatment can be performed, the impurity content can be extremely reduced and the life can be greatly extended.

  In addition, the carbon heating element of the present invention saves time for applying and drying the synthetic resin solution for bonding the carbon fiber yarn, so that the productivity is significantly improved and the synthetic resin solution is unevenly applied. Variation in the heat generation distribution can be prevented.

It is a manufacturing process figure of the conventional carbon heating element. It is a photograph which shows one Example of the carbon heater using the conventional carbon heating element. It is a figure which shows the defect state of the carbon fiber yarn used for manufacture of the conventional carbon heating element. It is a photograph which shows the electric current application state of the carbon heater using the conventional carbon heating element. FIG. 2 is an exemplary view of a narrow loom used for weaving a narrow woven carbon body and a narrow woven fabric according to an embodiment of the present invention. It is an illustration figure of the narrow woven carbon body by one Example of this invention. It is a manufacturing-process figure of the carbon heating element by one Example of this invention. It is a detailed sectional view of a carbon forming object by one example of the present invention. It is detail sectional drawing of the carbon molded object by the other Example of this invention. It is a photograph which shows the electric current application state of the carbon heater using the carbon heating element of this invention. It is a comparative photograph of a conventional carbon heater and a carbon heater according to the present invention.

  The present invention is a method of attaching a current-carrying clip to a narrow woven carbon body obtained by physically braiding a plurality of carbon fiber yarns without using a synthetic resin solution without performing another processing. The technical idea is to perform primary and secondary heat treatments, and to perform high temperature tertiary heat treatment for removing residual impurities.

  For this reason, in the present invention, a narrow woven fabric obtained by arranging and braiding a plurality of carbon fiber yarns in one direction to form a narrow-width woven carbon body, or by arranging and braiding raw yarns in one direction. After carbonizing to form a narrow woven carbon body, a carbon heating element is manufactured using the narrow woven carbon body.

  The method for producing a carbon heating element of the present invention will be described in detail with reference to the accompanying drawings and examples.

  FIG. 5 is a view schematically showing a narrow loom used for weaving a narrow woven carbon body and a narrow woven fabric according to an embodiment of the present invention, and FIG. 6 is an embodiment of the present invention. FIG. 7 schematically shows a manufacturing process of a carbon heating element according to an embodiment of the present invention, and FIG. 8 shows an embodiment of the present invention. FIG. 9 is a diagram illustrating in detail a cross section of a carbon molded body according to an example, FIG. 9 is a diagram illustrating in detail a cross section of a carbon molded body according to another embodiment of the present invention, and FIG. 10 is a carbon heating element according to the present invention. FIG. 11 is a photograph comparing a conventional carbon heater with a carbon heater according to the present invention.

  Referring to FIGS. 5 to 11, first, in the narrow woven carbon body used in the carbon heating element of the present invention, the carbon fiber yarn is at least one lubrication selected from the group consisting of water, a surfactant and a silicon emulsion. It is produced by a step of dipping in an agent to form a lubricant-impregnated carbon fiber yarn, and a step of arranging 3 to 24 of this lubricant-impregnated carbon fiber yarn in one direction and braiding to form a narrow-width woven carbon body.

  Carbon fiber yarns can be arranged and woven as warps and wefts with a general loom to make wide carbon fibers, and these carbon fibers can be slit to form narrow-width woven carbon bodies. When blading at an angle of more than 0 °, a phenomenon of refraction occurs, which is technically extremely difficult, and accordingly, it is not practical. In addition, fluffing and other distortions occur in the slitting surface of the carbon fiber during the slitting process, and the variation in resistance characteristics and heat generation distribution becomes serious at these strained parts. Therefore, the fine woven and slitted by the general method described above. Width-woven carbon bodies cannot be used for the production of carbon heating elements. Therefore, a carbon heating element is manufactured by using a relatively small number (for example, four) of carbon fiber yarns as warp yarns with a narrow loom and interweaving them to form a narrow width woven carbon body as it is. Must.

  The carbon heating element of the present invention is manufactured from a narrow woven carbon body obtained by physically woven carbon fiber yarns. The carbon fiber yarns used in the production of narrow-width woven carbon bodies are classified into PAN-based carbon fiber yarns, pitch-based carbon fiber yarns, and viscose-based carbon fiber yarns depending on the raw material, and the narrow-width weaves that are materials for carbon heating elements As the carbon body, any of a PAN-based carbon fiber yarn, a pitch-based carbon fiber yarn, and a viscose-based carbon fiber yarn may be used, but the PAN-based carbon fiber yarn and the pitch-based carbon fiber yarn have a rectangular cross section. A process of arranging a plurality of PAN-based carbon fiber yarns or pitch-based carbon fiber yarns in one direction and braiding them into a narrow woven carbon body is practically difficult. Therefore, in the present invention, it is preferable to produce a narrow-width woven carbon body using a viscose-based carbon fiber yarn having a circular cross section that is easy to narrow-width weave.

  However, when carbon fiber yarns with low bending strength are arranged in one direction as they are and braiding, the carbon fiber yarns are not easily braided at a certain angle, causing not only a phenomenon of refraction, but also the carbon fibers being braided. There is also the possibility of fluffing with the yarn.

  Therefore, in the present invention, the carbon fiber yarn wound around the bobbin is at least selected from the group consisting of water, a surfactant and a silicon emulsion so that the carbon fiber yarn is easily braided at a certain angle. Immerse in one lubricant for 20 to 60 minutes to obtain a lubricant-impregnated carbon fiber yarn with increased flexural strength. As the lubricant for increasing the flexural strength of the carbon fiber yarn, water, a surfactant and a silicon emulsion may be used alone, or two or more kinds may be mixed and used.

  The lubricant-impregnated carbon fiber yarn soaked in such a lubricant has an increased bending strength and is easily bladed, and the occurrence of fluff is also suppressed. In the production of a lubricant-impregnated carbon fiber yarn having increased flexural strength, if the time for dipping the carbon fiber yarn in the lubricant is less than 20 minutes, the flex strength is not such that the carbon fiber yarn is easily braided. When the time for immersing the carbon fiber yarn in the lubricant exceeds 60 minutes, the bending strength of the carbon fiber yarn does not increase any more.

  As described above, the lubricant-impregnated carbon fiber yarns that have been immersed in the lubricant and increased in flexural strength are arranged in one direction and braided to obtain a narrow-width woven carbon body.

  In the present invention, the carbon fiber yarns are not arranged as warps and wefts in the narrow loom, but all 3 to 24 carbon fiber yarns are arranged as warps in the narrow loom so that these warp yarns cross each other in a zigzag manner. As shown in FIG. 6, it is made into a web-like narrow-width woven carbon body in which 3 to 24 carbon fiber yarns are arranged in one direction. In the production of a web-like narrow woven carbon body, if the number of carbon fiber yarns arranged as warps is less than 3, these carbon fiber yarns are interwoven to form a web-like narrow woven fabric. The fiber yarn is twisted to form a temporary combustion yarn. On the other hand, when the number of carbon fiber yarns arranged as warps exceeds 24, the carbon fiber yarns are braided at an excessive angle, not only the workability of the carbon fiber yarns is lowered, but also the width of the narrow woven carbon body is reduced. Since it becomes excessive, the electrical resistance value decreases excessively.

  Specifically, as shown in FIG. 5, a narrow loom 200 that manufactures a carbon fiber narrow fabric by arranging and braiding 3 to 24 carbon fiber yarns 240 a and 240 b as warp yarns includes a table 210 and a table 210. A plurality of carriers 230a and 230b that rotate while rotating, and winding rollers 260 and 270 on which the carbon fiber narrow fabric 100 woven from the carriers 230a and 230b is wound are provided.

  Here, the plurality of carriers 230 a and 230 b rotate along the “∞” -shaped movement path formed on the table 210. When the carriers 230a and 230b rotate, the carbon fiber yarns 240a and 240b wound around the carriers 230a and 230b are mutually braided by a yarn guide (not shown) along the path of the carriers 230a and 230b. A carbon fiber narrow fabric 100 is formed, and the carbon fiber narrow fabric 100 is wound on a winding roller 260. Here, when the carriers 230a and 230b move along the movement path, the braiding angles of the respective carbon fiber yarns 240a and 240b moving to the yarn guide for braiding are adjusted so as not to exceed 60 °. . When the braiding angle in the yarn guide of the carbon fiber yarns 240a and 240b exceeds 60 °, the carbon fiber yarns 240a and 240b may be cut.

  That is, a plurality of carbon fiber yarns, preferably a viscose carbon fiber yarn having a circular cross section, is set in a narrow loom and arranged as warp yarns, and the carbon fiber yarns arranged as these warp yarns cross each other in a zigzag manner. Then, a narrow woven carbon body is obtained by braiding. A plurality of carbon fiber yarns having the same diameter can be arranged as warp yarns and interwoven to obtain a narrow width woven carbon body. Carbon fiber yarns having different diameters can be arranged as warp yarns and interwoven to obtain a narrow width woven carbon material. It can also be a body.

  Since such a narrow-width woven carbon body is obtained by arranging a plurality of carbon fiber yarns in one direction and braiding them into a narrow-width woven structure, the narrow-width woven carbon body is formed on both sides and both ends of the narrow-width woven carbon body. No distortion such as fuzz occurs at all, the outer shape is clean, and the woven form is reliably maintained. Therefore, a conventional carbon fiber in which a plurality of carbon fiber yarns must be bonded in parallel by applying a synthetic resin solution that is regarded as an impurity after arranging a plurality of carbon fiber yarns in parallel with a constant width without braiding. Unlike the material, the narrow woven carbon body of the present invention, which is solidly produced by arranging and braiding a plurality of carbon fiber yarns in one direction, is not coated with a synthetic resin solution, but also is a narrow woven carbon body. Without using any means for maintaining the woven form, the narrow woven carbon body is used as it is for the production of a carbon heating element.

  Further, apart from the method of forming a narrow woven carbon body by arranging and braiding a plurality of carbon fiber yarns in one direction as described above, the method for producing a carbon heating element of the present invention comprises 3 to 24 A stage in which a polyacrylonitrile raw yarn or a viscose raw yarn is arranged in one direction and braided to form a web-like narrow woven fabric, and while the thin woven fabric is stretched in the length direction in an inert gas atmosphere, 1, A narrow woven carbon body is obtained by carbonizing at 500 to 2,500 ° C. to obtain a narrow woven carbon body.

  Weaving a narrow woven fabric using raw yarns with excellent processability compared to carbon fiber, and then obtaining a narrow woven carbon body through a process of flameproofing and carbonizing the narrow woven fabric to obtain a carbon heating element. Can be used in the manufacture of

  However, it is technically possible to weave a biaxial woven fabric using warp and weft polyacrylonitrile yarn or viscose yarn, and carbonize the biaxial fabric while simultaneously stretching in both the warp and weft directions. It is extremely difficult and lacks practicality.

  Therefore, in the present invention, instead of arranging the polyacrylonitrile raw yarn, which is a raw material of PAN-based carbon fiber, or the viscose raw yarn, which is a raw material of viscose-based carbon fiber, as warp and weft yarns, a polyacrylonitrile raw material is used with a narrow loom. By arranging 3 to 24 yarns or viscose raw yarns as warp yarns, and braiding these warp yarns so as to cross each other in a zigzag manner, 3 to 24 raw yarns are unidirectional as shown in FIG. A web-like narrow woven fabric arranged in the above.

  In this way, the polyacrylonitrile raw yarn or the viscose raw yarn crosses each other in a zigzag manner and is braided at a constant angle, and proceeds only in one direction to obtain a uniaxial web-like narrow woven fabric. In the production of this narrow fabric, if there are less than three yarns arranged in one direction, the yarns are not braided into a web-like narrow fabric, but the yarns are twisted. It becomes temporary burnt yarn. On the other hand, if the number of yarns arranged in one direction exceeds 24, the yarns are braided at an excessive angle, making it difficult to accurately draw the yarns in the length direction. The width of the narrow woven carbon body is excessively increased, and the electrical resistance value is excessively decreased.

  Specifically, as shown in FIG. 5, a narrow loom 200 that arranges 3 to 24 raw yarns 240 a and 240 b as warp yarns and forms a narrow fabric by braiding is rotated on a table 210 and a table 210. A plurality of carriers 230a and 230b that move while being wound, and winding rollers 260 and 270 around which the narrow fabric 100 woven from the carriers 230a and 230b is wound are provided.

  Here, the plurality of carriers 230 a and 230 b rotate along the “∞” -shaped movement path formed on the table 210. When the carriers 230a and 230b rotate, the respective raw yarns 240a and 240b wound around the carriers 230a and 230b are finely braided with a yarn guide (not shown) along the path of the carriers 230a and 230b. A narrow woven fabric 100 is formed, and the narrow woven fabric 100 is wound on a winding roller 260. Here, when the carriers 230a and 230b move along the movement path, the braiding angle in the yarn guide of the raw yarns 240a and 240b moving for braiding should not exceed 60 ° with respect to the vertical line. Adjusted. When the braiding angle of the yarns 240a and 240b in the yarn guide exceeds 60 °, the yarns 240a and 240b may be cut.

  That is, 3-24 yarns are set on a narrow loom and arranged as warps, and the yarns arranged as warps are brazed so as to cross each other in a zigzag manner to obtain a narrow fabric.

  The narrow fabric thus obtained is continuously transferred to a continuous carbonization furnace for carbonization treatment, and the continuous fabric for carbonization treatment is subjected to the longitudinal treatment in the longitudinal direction in an inert gas atmosphere such as argon. A narrow-width woven carbon body is produced by carbonizing at a high temperature while stretching.

  In general, a polyacrylonitrile yarn, a viscose yarn and a pitch yarn are individually stretched in the length direction while being individually stretched in the inert gas atmosphere at a temperature range of the first half of 1,000 ° C., ie, 1,000 to 1,500. Carbon fiber can be constituted by carbonization treatment at a temperature of 0 ° C., but a narrow woven fabric obtained by arranging and braiding 3 to 24 yarns in one direction instead of the yarn alone is 1,000. Carbonization is not reliably performed in the first half of the temperature range.

  Therefore, in the present invention, the narrow woven carbon body is subjected to carbonization treatment at a temperature of 1,500 ° C. or higher, preferably 1,500 to 2,500 ° C. while stretching the narrow woven fabric in the length direction. Manufacturing. In the production of a narrow woven carbon body, if the temperature for carbonizing a narrow woven fabric stretched in the length direction in an inert gas atmosphere in a carbonized tunnel continuous furnace is less than 1,500 ° C., the narrow woven fabric Is not fully carbonized. On the other hand, if the temperature for carbonizing the narrow fabric stretched in the length direction exceeds 2,500 ° C., the flame-resistant narrow fabric may burn as it is without being carbonized.

  Similarly, such a narrow woven carbon body has characteristics that no distortion such as fluff is generated at both sides and both ends, the outer shape is clean, and the woven form is firmly maintained. Therefore, a conventional carbon fiber in which a plurality of carbon fiber yarns must be bonded in parallel by applying a synthetic resin solution that is regarded as an impurity after arranging a plurality of carbon fiber yarns in parallel with a constant width without braiding. Unlike the material, the narrow woven carbon body of the present invention, which is solidly produced by arranging and braiding a plurality of carbon fiber yarns in one direction, is not coated with a synthetic resin solution, but also is a narrow woven carbon body. Without using any means for maintaining the woven form, the narrow woven carbon body is used as it is for the production of a carbon heating element.

  The method for producing a carbon heating element of the present invention includes a step of winding a narrow woven carbon body around the surface of the heat-resistant main shaft to form a carbon molded body.

  A narrow woven carbon body obtained by arranging and braiding a plurality of carbon fiber yarns in one direction, or a narrow woven carbon body obtained by carbonizing a narrow woven fabric obtained by arranging and braiding raw yarns in one direction. A helical carbon molded body is formed by spirally winding the surface of a heat-resistant main shaft such as a silica rod having a melting point of 1300 ° C.

  In this way, the carbon molded body formed by spirally winding the surface of the heat-resistant main shaft does not cause any distortion such as fluff at both sides and both ends as a narrow-width woven carbon body, and the carbon molded body has an outer shape. Has the property of being kept clean. Therefore, it is not necessary to apply a synthetic resin solution so as to maintain the outer shape of the helical carbon molded body, and the current-carrying clips are attached while twisting the carbon yarns at both ends of the carbon molded body without twisting. Can do.

  Moreover, the manufacturing method of the carbon heat generating body of this invention includes the step which attaches the clip for electricity supply to the both ends of a carbon molded object, respectively.

  Electric current clips are attached to both ends of the carbon molded body so that a primary heat treatment is performed by applying an electric current to the carbon molded body in which the narrow-width woven carbon body is spirally formed. The current-carrying clips attached to both ends of the carbon molded body are made of a material such as an aluminum wheel or a copper wheel that has excellent electrical conductivity and has surface characteristics that stick to the carbon molded body.

  When a current is applied to the energizing clips attached to both ends of the carbon molded body as described above to energize the carbon molded body, the carbon molded body is heat-treated at a constant temperature and deformed into a heat-treated carbon molded body.

  The method for producing a carbon heating element of the present invention includes a step of applying a current to a current-carrying clip under a gas phase hydrocarbon atmosphere to subject the carbon molded body to a primary heat treatment to obtain a heat treated carbon molded body, and the heat treated carbon. Separating the molded body from the heat resistant spindle.

  A constant thickness carbon layer coating was vapor-deposited on the surface by applying a current to the current-carrying clips at both ends of the carbon molded body under a gas-phase hydrocarbon atmosphere and performing a primary heat treatment at 900 to 1200 ° C. A heat-treated carbon molded body is obtained.

  Specifically, a power source is connected to current-carrying clips at both ends of a carbon molded body spirally wound on the surface of the heat-resistant main shaft, and is stored in a reactor in a gas phase hydrocarbon atmosphere. When a current is applied to the carbon molded body from the power source through the energizing clip and the temperature of the carbon molded body is raised to 900 to 1200 ° C., carbon generated from the vapor phase hydrocarbons in the reactor is thermally decomposed. Is vapor-deposited on the surface of the substrate to form a carbon layer coating. If the temperature at which the carbon molded body is subjected to primary heat treatment to vapor-deposit a carbon layer coating on the surface of the carbon molded body is less than 900 ° C., the vapor phase hydrocarbon is not thermally decomposed, and the carbon is the surface of the carbon molded body. Is not vapor deposited. On the other hand, when the temperature at which the carbon molded body is subjected to the primary heat treatment exceeds 1200 ° C., the heat-resistant main shaft supporting the carbon molded body is melted by high heat.

  The heat-treated carbon molded body on which the carbon layer coating is vapor-deposited by the primary heat treatment of such a carbon molded body is separated from the heat-resistant main axis, and the separated heat-treated carbon molded body is subjected to secondary heat treatment.

  In addition, the method for producing a carbon heating element according to the present invention includes applying a current to the current-carrying clip of the separated heat-treated carbon molded body under a gas phase hydrocarbon atmosphere to perform a secondary heat treatment at 1300 to 2500 ° C. And obtaining a carbon film heating element on which a carbon layer having a nanocrystalline structure is deposited.

  Specifically, the heat-treated carbon molded body that has been subjected to the primary heat treatment and separated from the heat-resistant main shaft is received again in a reaction furnace under a gas-phase hydrocarbon atmosphere. When a current is applied from the power source to the heat treated carbon molded body through the energizing clip and the temperature of the heat treated carbon molded body is raised to 1300 to 2500 ° C., carbon generated in the reaction furnace while pyrolyzing the gas phase hydrocarbons is generated. Then, vapor deposition is performed on the surface of the heat-treated carbon molded body to form a carbon layer film having a nanocrystal structure with a certain thickness.

  By maintaining the secondary heat treatment temperature of the heat-treated carbon molded body at a constant temperature within the range of 1300 to 2500 ° C., the resistance value of the heat-treated carbon molded body is reduced to a desired level, thereby comprising the heat-treated carbon molded body. The resistance value of the carbon film heating element can be arbitrarily adjusted. If the temperature at which the heat-treated carbon molded body is subjected to secondary heat treatment to vapor-deposit a carbon layer coating having a nanocrystalline structure on the surface of the heat-treated carbon molded body is less than 1300 ° C., vapor-phase deposition is performed on the surface of the carbon-coated heating element. Not only does the carbon layer coating having a nanocrystalline structure contain a large amount of vaporizable amorphous carbon material, but the resistance value of the carbon coating heating element cannot be arbitrarily adjusted. On the other hand, when the temperature at which the heat-treated carbon molded body is subjected to the secondary heat treatment exceeds 2500 ° C., the carbon film heating element may be deteriorated or burned at a high temperature.

  The carbon film heating element obtained as described above contains a small amount of impurities and an amorphous carbon material, and high temperature tertiary heat treatment is performed to remove the impurities and the amorphous carbon material. To do.

  In the method for producing a carbon heating element of the present invention, the carbon film heating element is subjected to a third heat treatment at 2500 to 3500 ° C. in an inert gas or a reduced-pressure atmosphere to evaporate impurities and leave remaining amorphous carbon. Including the step of graphitization.

  The carbon film heating element subjected to the secondary heat treatment is subjected to a tertiary heat treatment at a high temperature of 2500 to 3500 ° C. under an inert gas or a reduced pressure atmosphere instead of a gas phase hydrocarbon to evaporate impurities, and to remain amorphous By graphitizing the carbon material, a carbon heating element with virtually no impurities remaining can be obtained. In this case, the third heat treatment for the carbon film heating element must be carried out under an inert gas or a reduced-pressure atmosphere instead of gas phase hydrocarbons in order to prevent deterioration or combustion of the carbon film heating element due to high heat. Don't be.

  If the temperature at which the carbon film heating element is subjected to the third heat treatment is less than 2500 ° C., impurities are not sufficiently evaporated from the carbon film heating element, and the amorphous carbon material is not sufficiently graphitized. On the other hand, if the temperature at which the carbon film heating element is subjected to the third heat treatment exceeds 3500 ° C., the cost for the third heat treatment increases significantly, leading to an increase in the manufacturing cost of the carbon heating element.

  By the third heat treatment of the carbon film heating element as described above, a carbon heating element substantially free of impurities is obtained.

  A carbon heater is manufactured by inserting such a carbon heating element into the inside of the tube, connecting the inserted carbon heating element to an electric wire, and then vacuum-sealing the tube to seal it.

  Hereinafter, the manufacturing method of the carbon heating element of the present invention will be described in detail with reference to specific examples. However, the following examples are for specifically illustrating the present invention and are not intended to limit the present invention.

<Example>
Eight viscose carbon fiber yarns having a linear density of 1.70 tex were set on a narrow loom and arranged as warp yarns, and these warp yarns were woven so as to cross each other in a zigzag manner to obtain a narrow weave carbon body.

  2. The narrow woven carbon body was spirally wound around a silica rod having a length of 45 cm and a diameter of 4 mm to form a carbon molded body.

  3. A current-carrying clip made of aluminum wheel material was attached to both ends of the carbon molded body.

  4). The current-carrying clip of the carbon compact on the surface of the heat-resistant main shaft was connected to a power source and received in a reactor in a gas-phase hydrocarbon atmosphere.

  5). A current is applied to the energizing clip, and the carbon molded body is subjected to a primary heat treatment at 1100 ° C. in a gas phase hydrocarbon atmosphere until the initial resistance of 43Ω is converted to a resistance of 33Ω. Was a heat treated carbon molded body vapor-deposited.

  6). The heat-treated carbon molded body was separated from the heat-resistant main shaft, and the separated heat-treated carbon molded body was received again in a reaction furnace under a gas phase hydrocarbon atmosphere.

  7). A current was applied to the energizing clip of the heat treated carbon molded body, and the heat treated carbon molded body was subjected to secondary heat treatment at 2000 ° C. in a gas phase hydrocarbon atmosphere until the initial resistance was changed from 33Ω to 13Ω, The carbon film heating element was formed by vapor-depositing a carbon layer film having a nanocrystal structure of 0.3 nm on the surface.

  8). The carbon film heating element is received in a reaction furnace under an inert gas atmosphere, an electric current is applied to the energizing clip, and the carbon film heating element is subjected to a tertiary heat treatment at 2600 ° C. for 30 seconds in an inert gas atmosphere. Thus, a spiral carbon heating element of 100V / 800W was manufactured.

<Experimental example>
The carbon heating element obtained by the above example was inserted into the inside of the tube, and after the inserted carbon heating element was connected to the electric wire, the tube was vacuum treated and sealed to produce a carbon heater.

  As a result of preparing 100 carbon heaters and 100 carbon heaters based on the conventional Korean Registered Patent Publication No. 10-0793973 and supplying the current continuously for 2000 hours, as shown in FIG. No carbonization phenomenon or blackening phenomenon (nickel evaporating ring) due to internal impurities occurred in the carbon heater of No. 1. However, in the conventional carbon heater, carbonization phenomenon and blackening phenomenon due to internal impurities occurred in 30 pieces.

From the result, it can be seen that the reliability of the carbon heater manufactured using the carbon heating element of the present invention is remarkably improved.

Claims (8)

Immersing the carbon fiber yarn in at least one lubricant selected from the group consisting of water, a surfactant and a silicon emulsion to form a lubricant-impregnated carbon fiber yarn;
Arranging 3 to 24 of the lubricant-impregnated carbon fiber yarns in one direction and braiding to form a narrow woven carbon body;
Winding the narrow-width woven carbon body around the surface of the heat-resistant main shaft to form a carbon molded body;
Attaching current-carrying clips to both ends of the carbon molded body,
Applying a current to the energizing clip and subjecting the carbon molded body to a primary heat treatment in a gas phase hydrocarbon atmosphere to form a heat treated carbon molded body;
Separating the heat treated carbon molded body from the heat resistant spindle;
A current was applied to the current-carrying clip of the separated heat-treated carbon molded body, followed by a secondary heat treatment at 1300 to 2500 ° C. under a gas phase hydrocarbon atmosphere, and a carbon layer coating having a nanocrystalline structure was deposited on the surface. A carbon coating heating element;
Performing a third heat treatment of the carbon film heating element at 2500 to 3500 ° C. in an inert gas or a reduced pressure atmosphere to evaporate impurities and graphitize the remaining amorphous carbon;
A method for producing a carbon heating element, comprising:   The method for producing a carbon heating element according to claim 1, wherein the carbon fiber yarn used in the step of forming the lubricant-impregnated carbon fiber yarn is a viscose-based carbon fiber yarn.   2. The method for producing a carbon heating element according to claim 1, wherein the carbon fiber yarn is immersed in a lubricant for 20 to 60 minutes in the step of forming the lubricant-impregnated carbon fiber yarn.   The method for producing a carbon heating element according to claim 1, wherein in the step of forming the narrow-width woven carbon body, carbon fiber yarns having different diameters are arranged in one direction and braided. A web-like narrow woven fabric obtained by arranging and braiding 3 to 24 polyacrylonitrile yarns or viscose yarns in one direction and carbonizing while stretching in the length direction in an inert gas atmosphere. A woven carbon body,
Winding the narrow-width woven carbon body around the surface of the heat-resistant main shaft to form a carbon molded body;
Attaching current-carrying clips to both ends of the carbon molded body,
Applying a current to the energizing clip and subjecting the carbon molded body to a primary heat treatment in a gas phase hydrocarbon atmosphere to form a heat treated carbon molded body;
Separating the heat treated carbon molded body from the heat resistant spindle;
A current was applied to the current-carrying clip of the separated heat-treated carbon molded body, followed by a secondary heat treatment at 1300 to 2500 ° C. under a gas phase hydrocarbon atmosphere, and a carbon layer coating having a nanocrystalline structure was deposited on the surface. A carbon coating heating element;
Performing a third heat treatment of the carbon film heating element at 2500 to 3500 ° C. in an inert gas or a reduced pressure atmosphere to evaporate impurities and graphitize the remaining amorphous carbon;
A method for producing a carbon heating element, comprising: The step of forming the narrow woven carbon body includes:
A process in which 3 to 24 polyacrylonitrile yarns or viscose yarns are arranged in one direction and braided to form a web-like narrow woven fabric;
A process of carbonizing at 1,500 to 2,500 ° C. to form a narrow woven carbon body while stretching the narrow woven fabric in the length direction in an inert gas atmosphere;
The method for producing a carbon heating element according to claim 5, comprising:   The method for producing a carbon heating element according to any one of claims 1 to 5, wherein a primary heat treatment temperature is 900 to 1200 ° C in the stage of forming the heat treated carbon molded body.   The carbon heating element manufactured based on the manufacturing method of the carbon heating element of Claim 1 or 5.