KR20230064692A - Method Of Manufacturing Black Alumina Ceramic With Far-infrared Radiation Function - Google Patents

Abstract

A method for manufacturing black alumina ceramics having a far-infrared radiation function according to exemplary embodiments of the present invention comprises: a raw material preparation step of combining black alumina raw materials; a ball mill step of grinding the black alumina raw material to produce black alumina powder; a stirring step of stirring the black alumina powder and binder; a molding step of filling the stirred black alumina powder into a mold and pressurizing it to form a molded body; a drying step of drying the molded body; and a sintering step of heating the dried molded body and then cooling and sintering the dried molded body. In the raw material preparation step, the black alumina raw material can form a second mixture by adding 15 to 35 parts by weight of a first additive to 100 parts by weight of the first mixture after mixing 55 to 45 wt% of a colorant with 45 to 55 wt% of aluminum oxide (Al_2O_3) to form a first mixture, and be combined by further adding 48.65 to 55.95 parts by weight of a second additive based on 100 parts by weight of the second mixture, wherein the first additive may be germanium (Ge).

Description

Manufacturing method of black alumina ceramic with far-infrared radiation function {Method Of Manufacturing Black Alumina Ceramic With Far-infrared Radiation Function}

The present invention relates to a method for manufacturing a black alumina ceramic having a far-infrared radiation function, and more particularly, by performing a ball mill process, a stirring process, a molding process, a drying process, and a firing process under optimized conditions for a black alumina raw material, respectively, It relates to a method for manufacturing black alumina ceramics having a far-infrared radiation function capable of minimizing defects such as bending, cracks, and bubbles and increasing production yield.

Along with the development of modern science and medicine, medical devices using waves have been developed, making innovations in diagnosis and treatment. Resonance Imaging), diagnostic devices such as whole body thermography (DITI), and treatment devices such as radiation therapy devices, infrared therapy devices, laser therapy devices, magnets, and magnetic generators.

However, waves (2㎛ or less) that are stronger than human waves, which are received and sent out in the human body, cause rejection rather than restoration of intrinsic function, causing side effects such as reduction of leukocytes and tissue transformation. ,　 Radiation, ultraviolet rays), and weak waves (more than 36㎛) cannot expect a therapeutic effect. Therefore, many treatment methods and devices using far-infrared rays having a wavelength range of 2 to 36 μm, which is the wavelength of human body waves, are being developed.

In this regard, infrared rays are generally classified into near-infrared rays, mid-infrared rays, and far-infrared rays according to the length of the wavelength, and have straightness, reflectivity, permeability, and absorption, which are properties of electromagnetic waves among physical characteristics. In addition, such infrared rays are characterized by generating heat by being directly irradiated to the target object for the property of electromagnetic waves in the absence of a transmission medium.

In other words, far-infrared rays penetrate deep into the object and cause resonance and resonance in the constituent molecules of the object to promote biological activity and induce various effects such as heat, property, drying, and softening to keep the human body in a healthy state. , It is used for various purposes such as a treatment part that can be effective due to a rise in temperature inside the human body, a sauna system, and health promotion of the general public. there is.

Among these infrared rays, far-infrared rays with a long wavelength (usually 25㎛ or more) are invisible to the eye, have strong penetrating power, are well absorbed by materials, and have strong resonance and resonance effects on organic compound molecules, which can prevent various diseases caused by heat action. It helps to eliminate the causative bacteria and expands capillaries to help blood circulation and cell tissue generation, which is effective in preventing aging, promoting metabolism, and preventing various adult diseases such as chronic fatigue through activation of cell tissue. As it is known, various types of heating devices having far-infrared ray heat dissipation panels have been developed and used.

In general, as a material applied to the heat dissipation panel, zirconia, aluminosilicate, and the like are used as main components. On the other hand, in order to increase heat dissipation or radiation characteristics, Fe ₂ O ₃ , MnO ₂ , etc. are added to the main material of the heat dissipation panel, or a small amount of the components are added to a resin such as polyethylene, and the heat dissipation panel is subjected to a process such as molding and sintering. It is also manufactured. Furthermore, there are techniques for improving heat dissipation characteristics or having additional functionality through a special coating treatment on the front surface of the heat dissipation panel.

Korean Patent Registration No. 10-1028946 (Prior Patent 1) discloses a composition made of silica sol, silicon oxide, a filler, silane, etc. as a coating agent for enhancing heat dissipation characteristics. The coating agent has excellent additional properties such as heat dissipation properties, antibacterial activity, and air purifying function, but when exposed to a high temperature environment for a long time, problems such as cracks or color change may occur, and the uniformity of the coating is somewhat poor, resulting in uniform heat dissipation characteristics There are cases where you cannot pay. Furthermore, there are still problems to be supplemented, such as improving the wear resistance of the coating film itself and preventing scratches.

That is, in the case of Prior Patent 1, since the far-infrared heat dissipation panel itself, which is a coated material, has low heat dissipation characteristics or low radiation characteristics, an alternative to improve heat dissipation characteristics or radiation characteristics using a coating film is proposed, but the unique far-infrared radiation heat dissipation panel properties cannot be improved.

Korean Patent Registration No. 10-2231527 (Prior Patent 2) discloses a method for manufacturing a sintered body made by mixing ore powder and additives for far-infrared radiation and then pressurizing and sintering the same, which emits a radiation range similar to the wavelength band of far-infrared radiation emitted from the human body. Disclosed is a far-infrared ray "radiation" ceramic sintered body that can be irradiated to the human body for a long time without side effects to provide a "far-infrared ray" therapeutic effect, and a manufacturing method of "ceramic" jewelry using the same.

However, since general ceramics having a far-infrared radiation function contain inorganic minerals such as germanium, there is a problem that the emission of far-infrared rays at a temperature similar to body temperature is somewhat insufficient, and conventional jewelry coated with a functional material capable of emitting far-infrared rays on the surface has functional properties. There was a problem that the material was easily peeled off from the surface of the jewelry.

In addition, in the case of Prior Patent 2, a method for manufacturing a ceramic having a far-infrared radiation function is disclosed, but since sericite is included as a main component, the color of the final product is expressed in white or light gray, and such a bright color It has a high light reflectance, so it is difficult to maximize heat dissipation or radiation characteristics.

As described above, black alumina ceramics having a far-infrared ray emitting function have the same or similar physical properties as general far-infrared ray emitting ceramics, but since black or close-to-black colors must be developed, a more precise and subdivided process must be performed. The specific conditions of the related process are also not generalized.

One of the various problems of the present invention is to provide a method for producing a black alumina ceramic having a low light reflectance and an excellent far-infrared radiation function by expressing a color close to black to black.

One of the various tasks of the present invention is to provide a method for producing a black alumina ceramic having a far-infrared radiation function capable of minimizing sintering defects such as bending, cracks, and bubbles by optimizing detailed process conditions.

One of the various tasks of the present invention is to provide a method for manufacturing a black alumina ceramic having a far-infrared radiation function with improved production yield through a plurality of firing steps sequentially performed through a step-by-step cooling process.

A method of manufacturing a black alumina ceramic having a far-infrared radiation function according to exemplary embodiments of the present invention includes a raw material preparation step of combining black alumina raw materials; A ball mill step of producing black alumina powder by pulverizing the black alumina raw material; A stirring step of stirring the black alumina powder and a binder; A molding step of filling a mold with the agitated black alumina powder and then pressurizing it to form a molded body; A drying step of drying the molded body; and a sintering step of heating and then cooling the dried molded body to sinter it. In the raw material preparation step, the black alumina raw material is mixed with 55 to 45% by weight of a colorant with respect to 45 to 55% by weight of aluminum oxide (Al ₂ O ₃ ) to form a first mixture, and then the first mixture 100 It may be combined by adding 15 to 35 parts by weight of the first additive to form a second mixture, and further adding 48.65 to 55.95 parts by weight of the second additive based on 100 parts by weight of the second mixture. 1 additive may be germanium (Ge).

The colorant comprises 4 to 6% by weight of TiO ₂ , 9 to 11% by weight of Fe ₂ O ₃ , 19 to 21% by weight of MnO ₂ , 9 to 11% by weight of SiO ₂ , and 4 to 6% by weight or less of Co ₂ O ₃ may be included.

The ball milling step may be performed by putting the black alumina raw material into a ball mill device and driving the ball mill device for 8 hours to 12 hours, and the particle size of the black alumina powder produced in the ball mill step is 0.109 μm to 0.109 μm. may be 0.153 μm.

The firing step may include a first firing step performed by raising the temperature from 0 ° C to 1,380 ° C; a second baking step performed by lowering the temperature from 1,380° C. to 1,100° C.; and a third firing step performed by lowering the temperature from 1,100 °C to 650 °C.

The first firing step may include a binder removing step performed by maintaining a temperature of 400° C. for a specific time to remove the binder.

The first firing step may include a first shrinkage step performed in a temperature range of 800 °C to 1,100 °C; And a second shrinkage step performed at a temperature range of 1,100 ℃ to 1,380 ℃; may further include.

The second additive is based on 100 parts by weight of the second mixture, 38 to 42 parts by weight of water (H ₂ O), 1,1 to 1.3 parts by weight of a dispersant, 9 to 11 parts by weight of PVA, 0.5 to 1.5 parts by weight of PEG, and 0.05 to 0.15 parts by weight of citric acid.

A method of manufacturing a black alumina ceramic having a far-infrared radiation function according to exemplary embodiments of the present invention includes a raw material preparation step of combining black alumina raw materials; A ball mill step of producing black alumina powder by pulverizing the black alumina raw material; A stirring step of stirring the black alumina powder and a binder; A molding step of filling a mold with the agitated black alumina powder and then pressurizing it to form a molded body; A drying step of drying the molded body; and a sintering step of heating and then cooling the dried molded body to sinter it. In the raw material preparation step, the black alumina raw material is mixed with 55 to 45% by weight of a colorant with respect to 45 to 55% by weight of aluminum oxide (Al ₂ O ₃ ) to form a first mixture, and then the first mixture 100 It may be combined by adding 15 to 35 parts by weight of the first additive to form a second mixture, and further adding 52.3 parts by weight of the second additive to 100 parts by weight of the first mixture, the first additive may be germanium (Ge).

The second additive may be composed of 40 parts by weight of water (H ₂ O), 1.2 parts by weight of a dispersant, 10 parts by weight of PVA, 1 part by weight of PEG, and 0.1 part by weight of citric acid, based on 100 parts by weight of the first mixture.

According to the manufacturing method of the black alumina ceramic having a far-infrared radiation function according to exemplary embodiments of the present invention, the black alumina having a low light reflectance and an excellent far-infrared radiation function by expressing a color close to black to black Ceramics can be made.

At this time, it is possible to optimize the detailed process conditions of each of the raw material preparation step, the ball mill step, the stirring step, the forming step, the drying step, and the firing step included in the manufacturing method of the black alumina ceramic having a far-infrared radiation function. Accordingly, bending, Sintering defects of black alumina ceramics having a far-infrared radiation function, such as cracks and bubbles, can be minimized.

In addition, the firing step may include a plurality of firing steps sequentially performed through a step-by-step cooling process, and accordingly, the production yield of black alumina ceramics having a far-infrared ray emitting function can be greatly improved.

1 is a flowchart illustrating a method of manufacturing a black alumina ceramic having a far-infrared radiation function according to exemplary embodiments of the present invention.
2 is a flowchart illustrating a firing step of a black alumina ceramic having a far-infrared ray function according to exemplary embodiments of the present invention.

Hereinafter, specific embodiments of the present invention will be described. The detailed descriptions that follow are provided to provide a comprehensive understanding of the methods, devices and/or systems described herein. However, this is only an example and the present invention is not limited thereto.

In describing the embodiments of the present invention, if it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, the definition should be made based on the contents throughout this specification. Terminology used in the detailed description is only for describing the embodiments of the present invention and should in no way be limiting. Unless expressly used otherwise, singular forms of expression include plural forms. In this description, expressions such as "comprising" or "comprising" are intended to indicate any characteristic, number, step, operation, element, portion or combination thereof, one or more other than those described. It should not be construed to exclude the existence or possibility of any other feature, number, step, operation, element, part or combination thereof.

Also, terms such as first, second, A, B, (a), and (b) may be used to describe components of an embodiment of the present invention. These terms are only used to distinguish the component from other components, and the nature, order, or order of the corresponding component is not limited by the term.

Manufacturing method of black alumina ceramic having far-infrared radiation function

Referring to FIG. 1 , a method for manufacturing a black alumina ceramic having a far-infrared ray emission function according to exemplary embodiments of the present invention includes a raw material preparation step (S1) of combining black alumina raw materials, and pulverizing the black alumina raw materials to obtain black alumina A ball mill step of producing powder (S2), an agitation step of stirring the black alumina powder and a binder (S3), a molding step of filling a mold with the agitated black alumina powder and then pressurizing it to form a molded body (S4), A drying step (S5) of drying the molded body, and a firing step (S6) of heating and then cooling the dried molded body to sinter it may be included.

In exemplary embodiments, in the raw material preparation step (S1), the black alumina raw material is a first mixture by mixing 55 to 45% by weight of a colorant with respect to 45 to 55% by weight of aluminum oxide (Al ₂ O ₃ ). After forming, a second mixture is formed by adding 15 to 35 parts by weight of the first additive based on 100 parts by weight of the first mixture, and 48.65 to 55.95 parts by weight of the second additive based on 100 parts by weight of the second mixture They can be combined by adding more.

When the content of aluminum oxide contained in the black alumina raw material is less than 45% by weight, the physical properties of the finally manufactured black alumina ceramic having a far-infrared ray function may be deteriorated, and the content of aluminum oxide contained in the black alumina raw material When this amount exceeds 55% by weight, the expression of a color close to black or black may not be properly performed, and thus light reflectance may be increased.

In one embodiment, the content of aluminum oxide included in the black alumina raw material may be 47.5 wt% to 52.5 wt%, preferably 50 wt%.

The colorant comprises 4 to 6% by weight of TiO ₂ , 9 to 11% by weight of Fe ₂ O ₃ , 19 to 21% by weight of MnO ₂ , 9 to 11% by weight of SiO ₂ , and 4 to 6% by weight or less of Co ₂ O ₃ may be included.

At this time, when the content of the colorant exceeds 55% by weight, physical properties of the finally manufactured black alumina ceramic having a far-infrared ray function may be deteriorated, and when the content of the colorant is less than 45% by weight, black to black alumina ceramics are produced. Since the expression of a color close to black is not properly performed, the light reflectance of the finally manufactured black alumina ceramic having a far-infrared ray function may be increased.

Among the components included in the colorant, when the content of TiO ₂ , Co ₂ O ₃ , MnO ₂ and Fe ₂ O ₃ is less than the above numerical range, the color expression of the black alumina ceramic having a far-infrared radiation function is not properly produced. If the content of TiO ₂ , Co ₂ O ₃ , MnO ₂ and Fe ₂ O ₃ among the components included in the colorant exceeds the above-mentioned numerical range, the manufactured far-infrared ray emission function may be increased. The physical properties of the black alumina ceramic having may be deteriorated.

In addition, when the content of SiO ₂ is less than or exceeds the above-mentioned numerical range, cracks occur in the manufactured black alumina ceramic having a far-infrared ray emitting function, or the manufactured black alumina ceramic having a far-infrared ray emitting function Theoretical density may be relatively low compared to general far-infrared radiation ceramics, and sintering defects such as bending, cracks, and bubbles may occur.

In one embodiment, the colorant is 5 wt% TiO ₂ , 10 wt% Fe ₂ O ₃ , 20 wt% MnO ₂ , 10 wt% or less SiO ₂ , and 5 wt% or less Co ₂ O ₃ can include

The first additive may be a single material made of germanium (Ge), and the second additive may be a mixture made of water (H ₂ O), a dispersant, PVA, PEG, and citric acid.

The first additive is 15 to 35 parts by weight, preferably 15 to 35 parts by weight, based on 100 parts by weight of the first mixture formed by mixing 45 to 55% by weight of aluminum oxide (Al ₂ O ₃ ) and 55 to 45% by weight of a colorant. 17.5 to 22.5 parts by weight, more preferably 20 parts by weight.

When the first additive is added in an amount of less than 15 parts by weight based on 100 parts by weight of the first mixture, the far-infrared radiation function may not be properly expressed, and the first additive is added in an amount of 35 parts by weight based on 100 parts by weight of the first mixture. When added in excess, physical properties of the finally manufactured black alumina ceramic having a far-infrared ray emission function may deteriorate, and cracks may occur or sintering defects such as banding, cracks, and bubbles may occur.

In another embodiment, in the raw material preparation step (S1), the black alumina raw material is mixed with 55 to 45% by weight of a colorant with respect to 45 to 55% by weight of aluminum oxide (Al ₂ O ₃ ) to form a first mixture. Then, a second mixture is formed by adding 15 to 35 parts by weight of the first additive based on 100 parts by weight of the first mixture, and 48.65 to 55.95 parts by weight of the second additive is further added based on 100 parts by weight of the first mixture. can be combined by

Specifically, the black alumina raw material according to an embodiment of the present invention is formed by adding 15 to 35 parts by weight of a first additive to 100 parts by weight of the first mixture to form a second mixture, and 100 parts by weight of the second mixture Unlike the combination by adding 48.65 to 55.95 parts by weight of the second additive, the black alumina raw material according to another embodiment of the present invention is obtained by adding 15 to 35 parts by weight of the first additive to 100 parts by weight of the first mixture. Forming a second mixture, it may be combined by further adding a second additive of 48.65 to 55.95 parts by weight based on 100 parts by weight of the first mixture. That is, the criterion for determining the addition weight of the second additive may be 100 parts by weight of the second mixture, or may be 100 parts by weight of the first mixture.

That is, the second additive may be added in an amount of 48.65 to 55.95 parts by weight, preferably 50.7 to 53.9 parts by weight, and more preferably 52.3 parts by weight, based on 100 parts by weight of the first mixture or 100 parts by weight of the second mixture. there is.

In one embodiment, the second additive is based on 100 parts by weight of the first mixture or 100 parts by weight of the second mixture, 40 parts by weight of water (H ₂ O), 1.2 parts by weight of a dispersant, 10 parts by weight of PVA, 1 part by weight part PEG, and 0.1 part citric acid by weight.

When the raw material preparation step (S1) is completed, a ball mill step (S2) of producing black alumina powder by pulverizing the prepared black alumina raw material may be performed.

Specifically, in the ball mill step (S2), 50% to 70% of aluminum oxide or alumina (Al2O3) balls are added to the ball mill device, the black alumina raw material is introduced, and the driving rpm of the ball mill device is set to 45 rpm. At 55 rpm, preferably, it can be performed by driving by setting to 48 rpm.

In exemplary embodiments, the particle size of the black alumina powder produced in the ball mill step (S2) may be 0.109 μm to 0.153 μm. At this time, when the particle size of the black alumina powder is smaller than 0.109 μm, the physical properties of the finally manufactured black alumina ceramic having a far-infrared ray function may deteriorate, and when the particle size of the black alumina powder is larger than 0.153 μm, the final The light reflectance of the black alumina ceramic having a far-infrared ray function manufactured by sintering may be increased or sintering defects such as banding, cracks, and bubbles may occur.

In exemplary embodiments, the ball mill step (S2) may be performed by driving the ball mill device for 8 to 12 hours. At this time, when the driving time of the ball mill device is less than 8 hours, the physical properties of the finally manufactured black alumina ceramic having a far-infrared ray emission function may deteriorate, and when the driving time of the ball mill device exceeds 12 hours, finally The light reflectance of the manufactured black alumina ceramic having a far-infrared ray emission function may increase or sintering defects such as banding, cracks, and bubbles may occur.

When the ball mill step (S2) is completed, a stirring step (S3) of stirring the black alumina powder with a binder, a forming step (S4) of filling and pressurizing the stirred black alumina powder into a mold, and drying the black alumina molded body. The drying step (S5) may be performed sequentially.

The stirring step (S3) may be performed by mixing the black alumina powder and the binder, introducing them into a pressure tank, and driving an agitator installed in the pressure tank at 30 rpm for 48 hours.

In the molding step (S4), after assembling a mold that meets the specifications, the mold is tilted by 45 °, the pressure of the pressure tank is set to 3 kg / mpa, and the stirred black alumina raw material and the binder are filled in the mold After maintaining the mold horizontally, and after 48 hours have elapsed, the molded body may be separated from the mold and then naturally dried for 24 hours.

In the drying step (S5), a constant temperature and humidity drying step of drying the naturally dried molded body in a constant temperature and humidity drying room set at an internal humidity of 80% and an internal temperature of 28 ° C. for a period of 10 to 15 days, It may be carried out by conducting a heat drying step of drying the molded article subjected to constant temperature and humidity drying for a period of 2 to 3 days in a heat drying room set to an internal temperature condition of 40 ° C to 50 ° C.

The constant temperature and humidity drying step and the thermal drying step may be sequentially performed.

After the drying step (S5) is performed, the firing step (S6) may be performed, and the overall progress of the firing step (S6) is shown in Table 1 below.

Temperature (℃) hour Temperature (℃) hour 0 - 100 24 800 - 1100 48 100 2 1100 2 100 - 250 48 1100 - 1380 30 250 2 1380 3 250 - 400 96 1380 - 1100 24 400 4 1100 One 400 - 800 48 1100 - 650 24 800 2

Referring to Table 1 and FIG. 2 together, the firing step (S6) is the first firing step (S61) performed by raising the temperature from 0 ° C to 1,380 ° C, and the first firing step (S61) performed by lowering the temperature from 1,380 ° C to 1,100 ° C. It may include a second firing step (S62), and a third firing step (S63) performed by lowering the temperature from 1,100 °C to 650 °C.

In the first firing step (S61), a first heating section for raising the temperature from 0 ° C. to 100 ° C., a second temperature raising section for raising the temperature from 100 ° C. to 250 ° C., and a third temperature raising section for raising the temperature from 250 ° C. to 400 ° C. A temperature-raising section, a fourth temperature-raising section for raising the temperature from 400 ° C to 800 ° C, a fifth temperature-raising section for raising the temperature from 800 ° C to 1,100 ° C, and a sixth temperature-raising section for raising the temperature from 1,100 ° C to 1,380 ° C. can do.

The first temperature-raising period may be performed over about 24 hours, the second temperature-raising period may be performed over about 48 hours, and the third temperature-raising period may be performed over about 96 hours. The fourth temperature-raising interval may be performed over about 48 hours, the fifth temperature-raising interval may be performed over about 48 hours, and the sixth temperature-raising interval may be performed over about 30 hours.

The first heating section may be a section for increasing moisture, the second heating section may be a section for degreasing the dispersant, and the third heating section may be a section for degreasing additive components such as PVA, PEG, citric acid, etc. can The fourth temperature-rising section may be a section for oxidizing and removing carbon or carbon components, the fifth temperature-raising section may be a section for primary shrinkage of the product, and the sixth temperature-raising section may be a section for secondary shrinkage of the product. It may be a section for In this case, the fifth temperature rising section may be referred to as a first contraction step, and the sixth temperature rising section may be referred to as a second contraction step.

The first firing step (S61) may further include temperature maintaining sections for maintaining a temperature for a predetermined time between the first heating section and the sixth heating section.

In exemplary embodiments, a first temperature maintaining section for maintaining a temperature of about 100 ° C. for about 2 hours may be performed between the first temperature raising section and the second temperature raising section, and the second temperature raising section and A second temperature maintaining section maintaining a temperature of about 250 ° C. for about 2 hours may be performed between the third heating section, and a temperature of about 400 ° C. is maintained between the third heating section and the fourth heating section. A third temperature maintaining section maintained for 4 hours may be performed, and a fourth temperature maintaining section maintaining a temperature of about 800 ° C. for about 2 hours may be performed between the fourth temperature increasing section and the fifth temperature increasing section. A fifth temperature maintaining section for maintaining a temperature of about 1,100 ° C. for about 2 hours may be performed between the fifth temperature raising section and the sixth temperature raising section, and a temperature of about 1,380 ° C. is maintained after the sixth temperature raising section. A sixth temperature maintaining period may be performed for about 3 hours.

The first temperature maintaining section may be a section for forming an internal line of the molded body, the second temperature maintaining section may be a section for degreasing the dispersant and forming an overall line, and the third temperature maintaining section may be a section for removing residual binder. The fourth temperature maintenance section may be a section for removing residual carbon or carbon components, and the fifth temperature maintenance section may be a section for smoother first shrinkage of the product. The sixth temperature maintaining section may be a section for completing the second shrinkage of the product and at the same time completing the physical properties of the product. At this time, the third temperature maintaining period may also be referred to as a binder removal step.

When the first to sixth temperature raising sections and the first to sixth temperature maintaining sections are alternately performed and the first firing step (S61) is completed, the second firing is performed by lowering the temperature from 1,380 ° C to 1,100 ° C Step (S62) and the third baking step (S63) performed by lowering the temperature from 1,100 ℃ to 650 ℃ can be performed in sequence.

The second firing step (S62) and the third firing step (S63) may be sections for suppressing stress caused by rapid cooling of the product.

In one embodiment, a seventh temperature maintaining section maintaining a temperature of about 1,100 ° C. for about 1 hour may be further performed between the second firing step (S62) and the third firing step (S63).

After the firing step (S6) is performed, the processing step (S7) may be performed in various ways according to the purpose, use, function, etc. of the final product, and black alumina ceramic having a far-infrared ray function as the processing step (S7) is completed. The manufacture of can be completed.

Experimental results of black alumina ceramics with far-infrared radiation

It was confirmed that the black alumina ceramic having a far-infrared ray function according to the present invention had a wavelength within 7.2 μm to 8.8 μm at the highest point of a wavelength curve measured at a distance of 20 cm using an infrared power meter.

In addition, it was confirmed that the black alumina ceramic having a far-infrared function according to the present invention had an output measured at a distance of 20 cm using the infrared power meter within 12 mW/cm ² to 18 mW/cm ² , and the infrared power meter After turning on the operation switch, it was confirmed that the output measured at a distance of 20 cm in 5 minute increments from the first 10 minutes to 90 minutes was within 10.8 mW/cm ² to 19.8 mW/cm ² .

On the other hand, after placing the black alumina ceramic having a far-infrared ray function according to the present invention on the radiation plate, the temperature of the radiation plate is operated at 340 ° C. The results of comparison and measurement with the Black Body using a spectrometer are shown in Table 2 below. Same as

Radiation plate temperature (℃) Infrared wavelength (mW) Radiant energy (W/m ² ) emissivity highest value 340 22 7.095*10 ³ 0.9812 lowest value 340 2.7 5.805*10 ³ 0.8028

Specifically, as shown in Table 2, it was confirmed that the black alumina ceramic having a far-infrared ray function according to the present invention had an infrared wavelength of 2.7 mW to 22 mW while maintaining the temperature of the radiation plate at 340 ° C. , to 5.805*10 ³ W/m ² to 7.095*10 ³ W/m ² , and it was confirmed to have an emissivity of 0.8028 to 0.9812.

In addition, the black alumina ceramic having a far-infrared ray function according to the present invention measured the radiation output at 340 ° C and 420 ° C, which are the surface temperatures of the radiation plate for 60 minutes and 240 minutes using an FT-IR Spectrometer, and the result was 6.45 * 10 ³ W / m ² to 1.01*10 ⁴ W/m ² It was confirmed to have radiation power stability within the range.

On the other hand, in order to measure the saturation temperature of the radiation plate, it was measured with a non-contact thermometer and a contact probe thermocouple thermometer, respectively, and it was confirmed that the center of the radiation plate had the highest temperature within the range of 342 ° C to 418 ° C.

As described above, the method for manufacturing a black alumina ceramic having a far-infrared ray function according to exemplary embodiments of the present invention includes a raw material preparation step (S1), a ball mill step (S2), a stirring step (S3), and a forming step (S4). , It may include a drying step (S5) and a firing step (S6), and since detailed process conditions for each step can be optimized, by expressing a color close to black or black, it has low light reflectance and excellent A black alumina ceramic having a far-infrared radiation function can be manufactured.

At this time, it is possible to optimize the detailed process conditions of each of the raw material preparation step, the ball mill step, the stirring step, the forming step, the drying step, and the firing step included in the manufacturing method of the black alumina ceramic having a far-infrared radiation function. Accordingly, bending, Sintering defects of black alumina ceramics having a far-infrared radiation function, such as cracks and bubbles, can be minimized.

In particular, the firing step (S6) may include a plurality of firing steps sequentially performed through a step-by-step heating process and a cooling process, and accordingly, the production yield of black alumina ceramics having a far-infrared ray emitting function can be greatly improved. there is.

However, the concept of the present invention is not necessarily limited thereto, and the method according to exemplary embodiments of the present invention can be applied to various product/technical fields other than the above-described product/technical fields.

Although various embodiments of the present invention have been described in detail above, those skilled in the art will understand that various modifications are possible to the above-described embodiments without departing from the scope of the present invention. . Therefore, the scope of the present invention should not be limited to the described embodiments and should not be defined, and should be defined by not only the claims to be described later, but also those equivalent to these claims.

Claims (9)

A raw material preparation step of combining black alumina raw materials;
A ball mill step of producing black alumina powder by pulverizing the black alumina raw material;
A stirring step of stirring the black alumina powder and a binder;
A molding step of filling a mold with the agitated black alumina powder and then pressurizing it to form a molded body;
A drying step of drying the molded body; and
A sintering step of heating and then cooling the dried molded body to sinter it; includes,
In the raw material preparation step, the black alumina raw material is mixed with 55 to 45% by weight of a colorant with respect to 45 to 55% by weight of aluminum oxide (Al ₂ O ₃ ) to form a first mixture, and then the first mixture 100 By adding 15 to 35 parts by weight of the first additive to form a second mixture, and further adding 48.65 to 55.95 parts by weight of the second additive with respect to 100 parts by weight of the second mixture,
The method of manufacturing a black alumina ceramic having a far-infrared radiation function, characterized in that the first additive is germanium (Ge). According to claim 1,
The colorant comprises 4 to 6% by weight of TiO ₂ , 9 to 11% by weight of Fe ₂ O ₃ , 19 to 21% by weight of MnO ₂ , 9 to 11% by weight of SiO ₂ , and 4 to 6% by weight or less of Co ₂ O ₃ Method for producing a black alumina ceramic having a far-infrared radiation function, characterized in that it comprises. According to claim 1,
The ball mill step is performed by driving the ball mill device for 8 to 12 hours after introducing the black alumina raw material into a ball mill device,
The method for producing a black alumina ceramic having a far-infrared radiation function, characterized in that the particle size of the black alumina powder produced in the ball mill step is 0.109 μm to 0.153 μm. According to claim 1,
In the firing step,
A first firing step performed by raising the temperature from 0 ° C to 1,380 ° C;
a second baking step performed by lowering the temperature from 1,380° C. to 1,100° C.; and
A method for producing a black alumina ceramic having a far-infrared radiation function comprising a; third firing step performed by lowering the temperature from 1,100 ℃ to 650 ℃. According to claim 4,
The first firing step,
Method for producing a black alumina ceramic having a far-infrared ray emission function comprising a; binder removal step performed by maintaining a temperature of 400 ° C. for a specific time to remove the binder. According to claim 4,
The first firing step,
A first shrinkage step performed at a temperature range of 800 ° C to 1,100 ° C; and
A method for producing a black alumina ceramic having a far-infrared radiation function, characterized in that it further comprises; a second shrinkage step carried out in a temperature range of 1,100 ℃ to 1,380 ℃. According to claim 1,
The second additive is based on 100 parts by weight of the second mixture, 38 to 42 parts by weight of water (H ₂ O), 1,1 to 1.3 parts by weight of a dispersant, 9 to 11 parts by weight of PVA, 0.5 to 1.5 parts by weight of PEG, and 0.05 to 0.15 parts by weight of citric acid. A raw material preparation step of combining black alumina raw materials;
A ball mill step of producing black alumina powder by pulverizing the black alumina raw material;
A stirring step of stirring the black alumina powder and a binder;
A molding step of filling a mold with the agitated black alumina powder and then pressurizing it to form a molded body;
A drying step of drying the molded body; and
A sintering step of heating and then cooling the dried molded body to sinter it; includes,
In the raw material preparation step, the black alumina raw material is mixed with 55 to 45% by weight of a colorant with respect to 45 to 55% by weight of aluminum oxide (Al ₂ O ₃ ) to form a first mixture, and then the first mixture 100 15 to 35 parts by weight of the first additive is added to form a second mixture, and combined by further adding 52.3 parts by weight of the second additive to 100 parts by weight of the first mixture,
The method of manufacturing a black alumina ceramic having a far-infrared radiation function, characterized in that the first additive is germanium (Ge). According to claim 8,
The second additive is composed of 40 parts by weight of water (H ₂ O), 1.2 parts by weight of a dispersant, 10 parts by weight of PVA, 1 part by weight of PEG, and 0.1 part by weight of citric acid, based on 100 parts by weight of the first mixture. Method for producing a black alumina ceramic having a far-infrared radiation function.

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