KR20230111569A - Glass ceramic and cooktop using same - Google Patents

Abstract

Disclosed herein is a ceramic glass in which color clarity is increased by controlling microstructure and cleanability is improved through a polishing process, and a cooktop to which the same is applied.
Ceramic glass according to an embodiment of the present invention may include a glass material having a concavo-convex layer formed on an upper surface thereof, and may have a color difference system L value of 85 or more and 100 or less.

Description

Ceramic glass and cooktop to which it is applied {Glass ceramic and cooktop using same}

The present invention relates to a ceramic glass and a cooktop to which the same is applied, and more particularly, to a ceramic glass in which color sharpness is increased by controlling a microstructure and cleanability is improved through a polishing process, and a cooktop to which the same is applied.

As a heat source for generating heat, an induction device (induction heating device) is used. In particular, a cooktop (or hob) is used as a cooking device for heating food using an induction device.

In general, ceramic glass with excellent heat resistance is used for the upper part of the cooktop. Ceramic glass rarely undergoes thermal shock fracture and has excellent mechanical strength and thermal conductivity.

Ceramic glass may be divided into white, black, and transparent ceramic glass according to color. Among them, the white ceramic glass has a unique problem in that it is inferior in aesthetics compared to the black and transparent ceramic glass.

In addition, if the crystal generation step execution time is increased during the manufacturing process and the cooling rate is increased in the cooling step in order to improve the aesthetics of the white ceramic glass, many surface irregularities are generated, resulting in poor cleanability.

An object of the present invention to solve the above problems is to provide a ceramic glass and a cooktop to which the same is applied, in which color sharpness is increased by controlling the microstructure and cleanability is improved through a polishing process.

Ceramic glass according to an embodiment of the present invention may include a glass material having a concavo-convex layer formed on an upper surface thereof, and may have a color difference system L value of 85 or more and 100 or less.

In addition, the ceramic glass according to an embodiment of the present invention may further include a coating layer applied to the entire surface of the uneven layer, and the coating layer may include ZrO ₂ and TiO ₂ .

In addition, in the ceramic glass according to an embodiment of the present invention, the glass material may include Li ₂ O: 5 to 15%, Al ₂ O ₃ : 15 to 25%, the rest of SiO ₂ and impurities in weight%.

In addition, in the ceramic glass according to an embodiment of the present invention, the glass material may have a thickness of 3 mm to 5 mm.

In addition, the ceramic glass according to an embodiment of the present invention may have a surface roughness Ra value of 0.1 μm or less.

In addition, in the ceramic glass according to an embodiment of the present invention, the coating layer may include, by weight, ZrO ₂ : 70 to 95%, the remainder of TiO ₂ and impurities.

In addition, in the ceramic glass according to an embodiment of the present invention, the coating layer may have a thickness of 400 nm or less.

In addition, the ceramic glass according to an embodiment of the present invention may have a surface roughness Rz value of 1.2 μm or less.

In addition, the ceramic glass according to an embodiment of the present invention may have a Vickers hardness (Hv) of 920 or more and 1000 or less.

In addition, the ceramic glass according to an embodiment of the present invention may have a thermal shock temperature of 525°C or more and 575°C or less, and a thermal resistance temperature of 825°C or more and 875°C or less.

In addition, the ceramic glass according to an embodiment of the present invention may further include a glass printed layer for displaying the center of the crater on the upper portion of the glass material.

In addition, a method for manufacturing a ceramic glass according to an embodiment of the present invention includes preparing a ceramic glass precursor; generating crystals by heating the ceramic glass precursor; cooling the ceramic glass in which the crystals are formed; molding the cooled ceramic glass; and polishing the molded ceramic glass.

In addition, the method of manufacturing the ceramic glass according to an embodiment of the present invention may further include coating the polished ceramic glass.

In addition, in the ceramic glass manufacturing method according to an embodiment of the present invention, the manufacturing of the ceramic glass precursor may be performed by melting the ceramic glass powder at 1400 to 1600 ° C and then cooling to room temperature at a cooling rate of 40 ° C / min or less.

In addition, in the ceramic glass manufacturing method according to an embodiment of the present invention, the step of generating the crystals may include a first heating step of holding the crystal at 600 to 800 ° C for 10 to 20 minutes and a second heating step of holding the crystal at 800 to 1000 ° C for 20 to 30 minutes.

In addition, in the method of manufacturing a ceramic glass according to an embodiment of the present invention, the cooling may be performed at a cooling rate of 20° C./min or more to room temperature.

In addition, in the ceramic glass manufacturing method according to an embodiment of the present invention, the coating step may be performed by applying a coating solution on the ceramic glass and then drying the ceramic glass at 600 to 800° C. for 5 to 15 minutes.

In addition, a cooktop according to an embodiment of the present invention includes a cooktop body; and a first glass provided on an upper portion of the cooktop body, wherein the first glass includes ceramic glass, wherein the ceramic glass includes a glass material having a concavo-convex layer formed on an upper surface thereof, and may have a color difference L value of 85 or more and 100 or less.

In addition, in the cooktop according to an embodiment of the present invention, the cooktop body includes a heater, and the cooktop includes: a second glass disposed on the same line as the first glass; a coupling device provided so that the first glass and the second glass are detachably coupled; a circuit board disposed under the second glass; and a coil seating plate disposed under the heater to seat the heater.

In addition, in the cooktop according to an embodiment of the present invention, the glass material may include Li ₂ O: 5 to 15%, Al ₂ O ₃ : 15 to 25%, the remainder of SiO ₂ and impurities, by weight.

In addition, in the cooktop according to an embodiment of the present invention, the surface roughness Rz value of the uneven layer may be 1.2 μm or less.

According to an example of the present invention, it is possible to provide a ceramic glass and a cooktop to which the ceramic glass is applied, in which color sharpness is improved by increasing the duration of the crystal generation step and the cooling speed of the cooling step, and cleanability is improved by performing a polishing process.

However, the effects that can be achieved by the ceramic glass and the cooktop to which the ceramic glass according to embodiments of the present invention is applied are not limited to those mentioned above, and other effects not mentioned above will be clearly understood by those skilled in the art from the description below.

1 is a schematic diagram of a ceramic glass according to an example of the present invention.
2 is an enlarged photograph of a cross-section of a ceramic glass according to an example of the present invention using a Transmission Electron Microscope (TEM).
3 is a flowchart of a ceramic glass manufacturing method according to an embodiment of the present invention.
4 is a view showing a cooktop according to an example of the present invention.
5 is an exploded perspective view of a cooktop according to an embodiment of the present invention.
6 is a photograph taken before washing after applying the kimchi contaminant to the cooktop top plate according to an example of the present invention.
7 is a photograph taken after applying a kimchi contaminant to a cooktop top plate according to an example of the present invention and then washing it.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention may be embodied in other forms without being limited to only the embodiments presented herein. In the drawings, in order to clarify the present invention, illustration of parts irrelevant to the description may be omitted, and the size of components may be slightly exaggerated to aid understanding.

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

Expressions in the singular number include plural expressions unless the context clearly dictates otherwise.

Ceramic glass according to an embodiment of the present invention may include a glass material having a concavo-convex layer formed on an upper surface thereof, and may have a color difference system L value of 85 or more and 100 or less.

1 is a schematic diagram of a ceramic glass according to an example of the present invention.

Referring to FIG. 1 , ceramic glass according to an example of the present invention may include a glass material having a concavo-convex layer formed on an upper surface thereof.

In addition, the ceramic glass according to an embodiment of the present invention may have a color difference system L value of 85 or more and 100 or less. Preferably, the L value of the color difference system may be 90 or more and 100 or less.

White ceramic glass has a unique problem in that it is inferior in aesthetics compared to black and transparent ceramic glass. In the present invention, in order to improve the aesthetics of the white ceramic glass, the color sharpness is improved by controlling the microstructure by increasing the execution time of the crystal forming step and speeding up the cooling rate of the cooling step.

Through this, even though the ceramic glass according to one embodiment of the present invention is applied to white ceramic glass, it is possible to secure high color clarity with a color difference L value of 85 or more and 100 or less.

2 is an enlarged photograph of a cross-section of a ceramic glass according to an example of the present invention using a Transmission Electron Microscope (TEM).

Referring to FIG. 2 , as a microstructure, hexahedral crystals inside the ceramic glass can be confirmed. Since hexahedral crystals affect the color clarity of ceramic glass, it is necessary to control the size and number of crystals to an appropriate level. In the present invention, the size and number of the hexahedral crystals are controlled through glass material components and manufacturing processes.

The ceramic glass according to one embodiment of the present invention may further include a coating layer applied to the entire surface of the uneven layer, if necessary.

The coating layer may include ZrO ₂ and TiO ₂ .

ZrO ₂ serves to improve strength, and TiO ₂ serves to improve corrosion resistance of ceramic glass. Therefore, the ceramic glass according to one embodiment of the present invention can secure excellent strength and corrosion resistance.

In the ceramic glass according to an embodiment of the present invention, the glass material may include, by weight, Li ₂ O: 5 to 15%, Al ₂ O ₃ : 15 to 25%, the remainder SiO ₂ and impurities.

Li ₂ O serves to improve the hardness of ceramic glass. Therefore, when the content of Li ₂ O is low, it may be difficult to sufficiently secure the hardness of the ceramic glass. However, when the content of Li ₂ O is excessive, manufacturing cost may increase. Therefore, it is preferable to contain 5 to 15% of Li ₂ O. More preferably, the content of Li ₂ O may be controlled to 5 to 10%.

Al ₂ O ₃ serves to improve corrosion resistance and durability of ceramic glass. Therefore, when the content of Al ₂ O ₃ is low, the corrosion resistance and durability of the ceramic glass may be deteriorated. However, when the content of Al ₂ O ₃ is excessive, manufacturing cost may increase. Therefore, it is preferable to contain 15 to 25% of Al ₂ O ₃ . More preferably, the content of Al ₂ O ₃ can be controlled to 17 to 22%.

SiO ₂ serves as a crystal nucleation agent in ceramic glass. Therefore, when the content of SiO ₂ is low, crystals in the ceramic glass are not sufficiently formed, and reflectance may be reduced. However, when the content of SiO ₂ is excessive, the hardness and durability of the ceramic glass may deteriorate.

In addition, since unintended impurities may inevitably be mixed from raw materials or the surrounding environment during a normal manufacturing process, they cannot be excluded. Since these impurities are known to anyone skilled in the ordinary manufacturing process, not all of them are specifically mentioned in this specification.

In the ceramic glass according to an embodiment of the present invention, the glass material may have a thickness of 3 mm to 5 mm. However, it is not limited thereto, and the thickness of the glass material may vary depending on the purpose and shape.

The ceramic glass according to an embodiment of the present invention may have a surface roughness Ra value of 0.1 μm or less. The surface roughness of the ceramic glass is due to the concavo-convex layer formed on the upper surface. The concavo-convex layer may be formed during a cooling step in a ceramic glass manufacturing method. In the present invention, by speeding up the cooling step time, an appropriate level of crystal nuclei is generated and the color clarity of ceramic glass is improved. However, if the cooling step is performed quickly, the surface of the glass material may be made very rough. Therefore, in the present invention, a smooth surface having a surface roughness Ra value of 0.1 μm or less can be implemented by performing a polishing step as a post-process.

In addition, in the ceramic glass according to an embodiment of the present invention, the coating layer may include, by weight, ZrO ₂ : 70 to 95%, the remainder of TiO ₂ and impurities.

ZrO ₂ serves to improve strength. Therefore, when the content of ZrO ₂ is low, it may be difficult to secure sufficient hardness. However, when the content of ZrO ₂ is excessive, manufacturing cost may increase. Therefore, it is preferable to contain 70 to 95% of ZrO ₂ . More preferably, the content of ZrO ₂ can be controlled to 80 to 85%.

TiO ₂ serves to improve the corrosion resistance of ceramic glass. Therefore, when the content of TiO ₂ is low, the corrosion resistance of the ceramic glass may be deteriorated. However, when the content of TiO ₂ is excessive, the strength may decrease.

In addition, since unintended impurities may inevitably be mixed from raw materials or the surrounding environment during a normal manufacturing process, they cannot be excluded. Since these impurities are known to anyone skilled in the ordinary manufacturing process, not all of them are specifically mentioned in this specification.

In addition, the coating layer may have a thickness of 400 nm or less. Preferably, the thickness may be 100 nm or less, more preferably, the thickness may be 30 nm or less.

If the thickness of the coating layer is too thin, antifouling performance and cleanability of the ceramic glass may be deteriorated. However, if the thickness of the coating layer is too thick, productivity may decrease.

Meanwhile, the thickness of the coating layer may be uniform over the entire surface of the uneven layer, but in order to make the surface more smooth, the thickness of the coating layer may be thicker at the valley portion than at the crest portion of the uneven layer.

The ceramic glass according to an embodiment of the present invention may have a surface roughness Rz value of 1.2 μm or less. Similar to the surface roughness Ra value, in the present invention, since the cooling step execution time is speeded up, the surface of the glass material can be made very rough. Therefore, in the present invention, a smooth surface having a surface roughness Rz value of 1.2 μm or less can be implemented by performing a polishing step as a post-process. Preferably, the surface roughness Rz value may be 0.8 μm or less.

In addition, the ceramic glass according to an embodiment of the present invention may have a Vickers hardness (Hv) of 920 or more and 1000 or less by forming a coating layer.

The ceramic glass according to an embodiment of the present invention may have a thermal shock temperature of 525°C or more and 575°C or less and a thermal resistance temperature of 825°C or more and 875°C or less by controlling glass material components. That is, the ceramic glass according to the present invention can realize sufficient heat resistance as a cooktop glass material.

The ceramic glass according to an embodiment of the present invention may further include a glass printed layer for displaying the center of the crater on the upper portion of the glass material. The glassware printing layer may be formed by printing glassware ink on top of the glass material. The glass printing layer may be formed in a line or cross shape to indicate the center of the crater, but is not limited thereto.

Next, a method for manufacturing ceramic glass according to another aspect of the present invention will be described.

A method for manufacturing a ceramic glass according to an embodiment of the present invention includes preparing a ceramic glass precursor; generating crystals by heating the ceramic glass precursor; cooling the ceramic glass in which the crystals are formed; molding the cooled ceramic glass; and polishing the molded ceramic glass.

In addition, a step of coating the polished ceramic glass may be further included.

3 is a flowchart of a ceramic glass manufacturing method according to an embodiment of the present invention.

Referring to FIG. 3 , a ceramic glass manufacturing method according to an embodiment of the present invention may include a series of ceramic glass precursor manufacturing steps, crystal generation steps, cooling steps, forming steps, and polishing steps.

First, a ceramic glass powder is prepared, melted at 1400 to 1600° C., and then cooled to room temperature at a cooling rate of 40° C./min or less to prepare a ceramic glass precursor.

Next, a crystal forming step for generating crystals in the ceramic glass is performed. The crystal generating step may include a first heating step maintained at 600 to 800 ° C. for 10 to 20 minutes and a second heating step maintained at 800 to 1000 ° C. for 20 to 30 minutes.

Nuclei for crystallization in the ceramic glass are generated through the first heating step, and crystallization may proceed based on the nucleus in the second heating step.

If the temperature in the crystal forming step is too low or the holding time is too short, crystals may not be sufficiently formed and color clarity and reflectivity may deteriorate. However, if the temperature of the crystal forming step is too high or the holding time is long, productivity may be reduced. Therefore, it is desirable to set an appropriate level of temperature and holding time in the crystal forming step.

In the cooling step, cooling to room temperature may be performed at a cooling rate of 20° C./min or more.

In general, the longer the crystal forming step and the shorter the cooling step, the better the color clarity of the ceramic glass, but the more unevenness occurs on the surface of the ceramic glass, resulting in poor cleanability. Therefore, in general, the cooling step execution time is not short.

However, in the ceramic glass manufacturing method according to one embodiment of the present invention, by performing the cooling step at a fast cooling rate of 20 ° C./min or more, the cooling step performance time is shortened to improve color clarity and cleanability through the polishing step.

Next, a step of forming the cooled ceramic glass may be performed. In the molding step, cutting and edge processing may be performed into a shape suitable for the purpose.

A step of polishing the molded ceramic glass may be performed.

In the polishing step, after applying an abrasive to a polishing pad (Softbuff), the molded ceramic glass surface may be polished. By performing the polishing step, the ceramic glass surface can be further smoothed to maximize cleanability.

Then, if necessary, a coating step may be additionally performed to form a coating layer on the polished glass ceramic surface.

The coating may be performed by applying the coating liquid to the entire upper portion of the ceramic glass and then drying at 600 to 800° C. for 5 to 15 minutes.

When the drying temperature is low or the drying time is short, the coating layer may not be uniformly formed. However, if the drying temperature is too high or the drying time is long, cracks may occur on the surface of the coating layer.

Next, a cooktop according to another aspect of the present invention will be described.

A cooktop according to an embodiment of the present invention includes a cooktop body; and a first glass provided on an upper portion of the cooktop body, wherein the first glass includes ceramic glass, wherein the ceramic glass includes a glass material having a concavo-convex layer formed on an upper surface thereof, and may have a color difference L value of 85 or more and 100 or less.

In addition, in the cooktop according to an embodiment of the present invention, the cooktop body includes a heater, and the cooktop includes: a second glass disposed on the same line as the first glass; a coupling device provided so that the first glass and the second glass are detachably coupled; a circuit board disposed under the second glass; and a coil seating plate disposed under the heater to seat the heater.

In addition, the glass material may include Li ₂ O: 5 to 15%, Al ₂ O ₃ : 15 to 25%, the rest of SiO ₂ and impurities, in weight%.

In addition, in the cooktop according to an embodiment of the present invention, the uneven layer may have a surface roughness Rz value of 1.2 μm or less through a polishing process. Preferably, the surface roughness Rz value may be 0.8 μm or less.

The reason for limiting the numerical value of the glass material is as described above, and the cooktop will be described in more detail below.

A cooktop according to an embodiment of the present invention includes a cooktop body; and a first glass provided on an upper portion of the cooktop body, wherein the first glass may include ceramic glass.

The cooktop body may include a heater, and the cooktop may include a second glass disposed on the same line as the first glass; a coupling device provided so that the first glass and the second glass are detachably coupled; a circuit board disposed under the second glass; and a coil seating plate disposed under the heater to seat the heater.

4 is a view showing a cooktop according to an example of the present invention, and FIG. 5 is an exploded perspective view of the cooktop according to an example of the present invention.

Referring to FIGS. 4 and 5 , the cooktop 1 according to an example of the present invention may include a cooktop body 10 and a first glass 110 provided on the top of the cooktop body 10 .

In addition, the cooktop 1 according to an example of the present invention may include a heater (hereinafter referred to as an induction heating coil 11), a second glass 120, a coupling device 200, a circuit board 12, and a coil seating plate 15.

The main body 10 may form the appearance of the cooking appliance 1 . The induction heating coil 11 is accommodated inside the main body 10 and can generate a magnetic field to induction heat the cooking container 2 . The induction heating coil 11 may be electrically connected to a main board (not shown) provided inside the main body 10 through an electric wire 11a.

The glass 100 may include a first glass 110 forming a first region 101 and a second glass 120 forming a second region 102 .

The circuit board 12 may be disposed under the second glass 120 . The circuit board 12 may include a display unit 13 and a touch unit 14 . The display unit 13 may be disposed below the display unit 102a formed in the second area 102 . The display unit 13 may display whether or not the cooking container 2 is heated by the induction heating coil 11 . Therefore, the user can check whether the cooking container 2 is heated through the display unit 102a. The touch unit 14 may be disposed below the input unit 102b formed in the second region 102 . The touch unit 14 may receive a touch signal from the input unit 102b. For example, the touch unit 14 may receive an input in a capacitive touch method. However, the present invention is not limited thereto, and the touch unit 14 may receive an input using a pressure-sensitive touch method. The user can adjust the current flowing through the induction heating coil through the input unit 102b and determine the degree to which the cooking container 2 is heated.

The induction heating coil 11 may be seated on the coil seating plate 15 . A coil seating hole 15a for seating the induction heating coil 11 may be provided in the coil seating plate 15 . A plurality of coil seating holes 15a may be provided.

The body 10 may further include a first frame 16 provided to support the glass 100 . The first frame 16 may be provided to support the glass 100 thereon. The first frame 16 may be formed to extend upward from the four ends of the coil seating plate 15 . The first frame 16 is provided so that the glass 100 can be seated and supported on the main body 10 .

The first glass 110 includes heating area guides 101a, 101b, and 101c and may support the cooking vessel 2. The cooking vessel 2 may be disposed in the first region 101 .

The second glass 120 may include a second area 102 , and the second area 102 may include a display unit 102a and an input unit 102b. The display unit 102a may be formed in the second area 102 to display various information about the cooking appliance 1, and the input unit 102b may be formed in the second area 102 to receive a control command from a user.

The first glass 110 and the second glass 120 are physically separated and can be detachably coupled by the coupling device 200 . The first glass 110 and the second glass 120 may be detachably coupled by the coupling device 200 .

The first glass 110 forms a first area 101 , and the cooking container 2 may be disposed in the first area 101 . The cooking vessel 2 disposed on the first glass 110 may be induction heated by a magnetic field generated by the induction heating coil 15 .

The second glass 120 forms a second area 102 separated from the first area 101, and cooking information of the cooking appliance 1 including the temperature of the cooking container 2, elapsed cooking time, and/or date/time may be displayed on the second area 102 through the display unit 102a.

In addition, an input unit 102b for receiving a control command from a user to turn on/off the cooking appliance 1 or control the temperature of the cooking container 2 may be provided in the second area 102 . The input unit 102b may receive an input by a user's touch.

The second glass 120 may be tempered glass. The first glass 110 and the second glass 120 may be formed of different materials. For example, the first glass 110 may be made of ceramic glass having excellent heat resistance, and the second glass 120 may transmit a touch signal to transmit a signal to the circuit board 12 provided on the lower side through touch. It may have characteristics capable of transmitting.

The first glass 110 and the second glass 120 may be detachably coupled to each other by the coupling device 200 . Specifically, the second glass 120 may be detachably coupled to the first glass 110 by the coupling device 200 . The second glass 120 may be coupled to the front of the first glass 110 . The second glass 120 may cover one side of the first glass 110 when combined with the first glass 110 .

In addition, when the circuit board 12 located in the second area 102 is repaired or broken, the second glass 120 corresponding to the second area 102 can be separated and replaced, thereby facilitating A/S.

Hereinafter, Examples and Comparative Examples are described in order to aid understanding of the present invention. However, the following description only corresponds to an example of the contents and effects of the present invention, and the scope and effects of the present invention are not necessarily limited thereto.

{Example}

<Surface Roughness Measurement Test>

The surface roughness measurement test was performed by measuring the amount of up and down movement of a stylus moving perpendicular to the specimen measurement surface through a surface roughness meter at room temperature (25 ° C).

In Table 1 below, the surface roughness of an uncoated general ceramic glass (Comparative Example) and a coated ceramic glass according to an example of the present invention (Example) are shown.

surface roughness comparative example
(μm) Example
(μm) Ra 0.29 0.17 Rq 0.36 0.22 Rz 1.49 1.17

Referring to Table 1, the surface roughness of Examples was measured lower than that of Comparative Examples. That is, it can be seen that the coated ceramic glass according to an embodiment of the present invention has a smoother surface, thereby improving cleaning properties.

<Vickers hardness measurement test>

Vickers hardness was measured by measuring the diagonal of the pyramid-shaped concave portion formed in the specimen to obtain hardness by pressing the specimen with a load of 0.05 kgf using pyramidal particles having a diamond quadrangular pyramid.

In the case of uncoated general ceramic glass (Comparative Example), Hv 860 was measured, and in the case of coated ceramic glass according to an example of the present invention (Example), Hv 920 was measured.

That is, it was confirmed that the hardness of the coated ceramic glass according to one embodiment of the present invention was improved by forming a coating layer.

<Kimchi cleaning test>

The kimchi cleaning test was carried out by applying cabbage kimchi from CJ CheilJedang to the entire cooktop top plate according to an example of the present invention, heating at 150 ° C for 30 minutes and taking a 30-minute break as one cycle, followed by 1 cycle/day for 6 days, followed by washing with a detergent dedicated to the cooktop.

5 is a picture taken before washing after applying a kimchi contaminant to the cooktop top plate according to an example of the present invention, and FIG. 6 is a picture taken after washing after applying a kimchi contamination source to the cooktop top plate according to an example of the present invention.

Referring to FIGS. 5 and 6 , it was confirmed that the cleaning property was improved by applying the ceramic glass on which the coating layer was formed according to an example of the present invention.

<Eating oil heating cleanability test>

The cooking oil heat cleaning test was performed by applying 3 g of cooking oil to the entire cooktop top plate according to an example of the present invention, maintaining it at each temperature for 30 minutes, and then measuring the degree of change in the surface color difference value (ΔE).

Table 2 below shows the color difference value (ΔE) of the cooktop top plate before and after the cooking oil heat cleaning test according to the temperature. In general, when the color difference value (ΔE) is 1.0 or less, it can be determined that the cleanability is good.

temperature
(℃) colorimeter value 220 0.07 250 0.16 280 0.59 300 0.08 325 0.14 350 0.73

Referring to Table 2, since the color difference value (ΔE) satisfies 1.0 or less in all temperature ranges, it can be determined that the cooking oil heat cleaning property is also excellent.

<Color difference meter measurement test>

The color difference measurement test was performed by comparing color difference values between a cooktop to which uncoated ceramic glass was applied (comparative example) and a cooktop to which ceramic glass coated according to an example of the present invention was applied (Example).

The L*a*b* color difference meter was measured using a spectrophotometer.

In the case of the comparative example, L: 84.8, a: -0.5, b: -0.5 were measured, but in the case of the example, L: 95, a: 1.0, b: 2.0 were measured.

That is, it was found that when the ceramic glass coated according to an example of the present invention is applied, the sharpness of white color is increased and a warm white color with excellent aesthetics can be realized.

<Heat resistance test>

The heat resistance test was performed by measuring the thermal shock temperature and thermal resistance temperature.

The thermal shock temperature was measured based on the UL 858 standard.

The ceramic glass fabricated according to one example of the present invention had a thermal shock temperature of 550°C.

The heat resistance temperature means a temperature that can be endured for a long time without damage. After putting the ceramic glass specimen prepared according to an example of the present invention in a heat resistance test chamber heated to a certain temperature and maintaining it for 1000 hours, the temperature at which the glass material is broken was measured. At this time, whether or not the damage was determined by the naked eye whether scratches occurred. On the other hand, the heat resistance temperature was also expressed as an average value after measuring three times.

The ceramic glass fabricated according to one example of the present invention had a heat resistance temperature of 850°C.

Accordingly, it can be determined that the ceramic glass according to one embodiment of the present invention has heat resistance suitable for use as a ceramic glass for a cooktop.

1: cooktop 10: cooktop body
12: circuit board 14: touch unit
16: first frame 18: fastening hole
110: first glass 120: second glass
200: coupling device

Claims (22)

A glass material having a concavo-convex layer formed on an upper surface thereof;
A ceramic glass having a color difference meter L value of 85 or more and 100 or less. The method of claim 1,
Further comprising a coating layer applied to the entire surface of the uneven layer,
The coating layer includes ZrO ₂ and TiO ₂ , ceramic glass. In claim 1,
The glass material is
In weight percent, Li ₂ O: 5 to 15%, Al ₂ O ₃ : 15 to 25%, the balance SiO ₂ and impurities. The method of claim 1,
The glass material has a thickness of 3 to 5 mm, ceramic glass. The method of claim 1,
A ceramic glass having a surface roughness Ra value of 0.1 μm or less. The method of claim 2,
The coating layer includes, in weight percent, ZrO ₂ : 70 to 95%, the remainder TiO ₂ and impurities, ceramic glass. The method of claim 1,
The coating layer has a thickness of 400 nm or less, ceramic glass. The method of claim 1,
A ceramic glass having a surface roughness Rz value of 1.2 μm or less. The method of claim 2,
A ceramic glass having a Vickers hardness (Hv) of 920 or more and 1000 or less. The method of claim 1,
A ceramic glass having a thermal shock temperature of 525 ° C. or more and 575 ° C. or less. The method of claim 1,
A ceramic glass having a heat resistance temperature of 825 ° C or more and 875 ° C or less. The method of claim 1,
Ceramic glass further comprising: a glass printed layer for displaying a center of a crater on the upper portion of the glass material. Preparing a ceramic glass precursor;
generating crystals by heating the ceramic glass precursor;
cooling the ceramic glass in which the crystals are formed;
molding the cooled ceramic glass; and
A ceramic glass manufacturing method comprising the step of polishing the molded ceramic glass. The method of claim 13,
The ceramic glass manufacturing method further comprising the step of coating the polished ceramic glass. The method of claim 13,
The step of preparing the ceramic glass precursor,
A method for manufacturing ceramic glass, which is performed by melting ceramic glass powder at 1400 to 1600 ° C and then cooling it to room temperature at a cooling rate of 40 ° C / min or less. The method of claim 13,
The step of generating the crystals includes a first heating step of holding at 600 to 800 ° C for 10 to 20 minutes and a second heating step of holding at 800 to 1000 ° C for 20 to 30 minutes. The method of claim 13,
The cooling step is a ceramic glass manufacturing method of cooling at a cooling rate of 20 ° C / min or more to room temperature. The method of claim 14,
The coating step is performed by applying the coating solution on the ceramic glass and then drying at 600 to 800 ° C. for 5 to 15 minutes. cooktop body; and
Including; a first glass provided on the upper part of the cooktop body,
The first glass includes a ceramic glass;
The ceramic glass,
A cooktop comprising: a glass material having a concavo-convex layer formed on an upper surface thereof, and having an L value of 85 or more and 100 or less. The method of claim 19
The cooktop body includes a heater,
The cooktop,
a second glass disposed on the same line as the first glass;
a coupling device provided so that the first glass and the second glass are detachably coupled;
a circuit board disposed under the second glass; and
A cooktop including a coil seating plate disposed below the heater to seat the heater. The method of claim 19
The glass material is
In weight percent, Li ₂ O: 5 to 15%, Al ₂ O ₃ : 15 to 25%, balance SiO ₂ and impurities. The method of claim 19
The ceramic glass,
A cooktop with a surface roughness Rz value of 1.2 μm or less.