KR102028445B1 - Self-generating smart heating glass and method thereof - Google Patents

Abstract

The present invention relates to a self-generating smart heating glass and a manufacturing method thereof, specifically, the present invention comprises the steps of heat-treating a carbon material; And a polyimide polymer is added to and mixed with the heat-treated carbon material, followed by impeller dispersion and 3 roll mill dispersion to sequentially prepare a planar heating element. And printing the planar heating element of the present invention on a glass substrate. And a method of connecting and laminating the planar heating element and the solar cell printed on the glass substrate.

Description

Self-generating smart heating glass and its manufacturing method {Self-generating smart heating glass and method

The present invention relates to a self-generating smart heating glass and a manufacturing method thereof.

In windows for automobile windows and construction, frost occurs on the glass due to the temperature difference between the outside and the inside in winter. The heating window is operated by attaching a hot wire surface to the surface or forming a hot wire directly on the glass surface, and then applying heat to both terminals to generate heat from the hot wire, thereby controlling the temperature of the window surface. However, the silicone heating wire is not aesthetically good, and the silicone heating wire in the automotive window has a problem of obstructing the driver's vision and a problem in that the heat transfer is delayed in the absence of the resistance wire and a lot of time is required to remove the frost.

The heating window under development uses an indium tin oxide film material, and when heated at high temperature, there is a problem in that electrical properties are changed and deteriorated, and heat resistance, chemical resistance, and wear resistance are weak. Indium tin oxide is also an expensive material. In order to apply the heating device to the glass window to obtain a defrosting effect is sufficient heat generation, when using a transparent heating film at a low voltage of 12 V, there is a problem that is difficult to drive due to high surface resistance. In addition, in order to remove frost and frost by increasing the temperature of the glass surface while driving at a low voltage, a heating element having a low resistance value is required. For this purpose, a metal mesh is conventionally used in the pyrosol method, printing method, or photolithography method. It was formed to be invisible to the field of view, and a method of forming a coating film on the pattern was used. However, there may be problems caused by the diffraction and interference visually, and there is a problem of deterioration of fairness and price increase.

In addition, recently, a technology for manufacturing a planar heating element using various materials such as carbon has been developed, but there is a problem in that the heater durability is not good, and problems such as agglomeration phenomenon are not good in dispersibility. Therefore, it is necessary to develop a new technology that can solve this problem.

On the other hand, a photovoltaic module is a device that converts light energy into electrical energy using the properties of a semiconductor, and can change the direct current (DC) current produced in the solar cell to alternating current (AC) to supply power for the home. Most solar panels are installed on roofs with high solar radiation. The installation of solar panels is mainly mounted on a support having a certain inclination angle to efficiently receive sunlight, but is only applied to a limited space on the roof or the roof of a building.

Accordingly, the present inventors have applied the solar cell to the heating glass manufacturing, which enables self-heating even at low voltage, maintains stability even in a high temperature environment, establishes a manufacturing process of the planar heating element having excellent dispersibility, The present invention was completed by manufacturing.

Republic of Korea Patent No. 10-1809690

Accordingly, an object of the present invention is to provide a method for producing a planar heating element capable of self-heating even at low voltage, maintaining stability in a high temperature environment, and having excellent dispersibility.

Another object of the present invention is to provide a planar heating element produced by the method of the present invention.

Another object of the present invention to provide a heating system comprising the planar heating element of the present invention.

Another object of the present invention is to provide a method for producing a self-generating smart heating glass using the planar heating element of the present invention.

Another object of the present invention is to provide a self-generating smart heating glass produced by the method of the present invention.

The present invention to achieve the above object, the step of heat-treating a carbon material; And adding and mixing the polyimide polymer to the heat-treated carbon material, and sequentially performing impeller dispersion and 3 roll mill dispersion to prepare a paste.

In one embodiment of the present invention, the carbon material may include one or more selected from the group consisting of graphite, carbon fibers, carbon nanofibers, and carbon nanotubes.

In one embodiment of the present invention, the carbon material is a mixture of graphite (graphite) and carbon nanotubes, the graphite and carbon nanotubes may be mixed in a weight ratio of 90: 5 ~ 95: 1.

In one embodiment of the present invention, the heat treatment may be a heat treatment for 1 to 2 hours at 1,000 ℃ ~ 1,200 ℃ by inducing vacuum at a high frequency.

In one embodiment of the present invention, the mixing ratio of the carbon material and the polyimide polymer may be 6: 4 to 4: 6.

In one embodiment of the present invention, the impeller dispersion is to disperse with stirring for 1 to 2 hours at a speed of 600 ~ 800rpm, the three roll mill (3 roll mill) dispersion is the gap between the roll and the diameter of the carbon material It may be to adjust the dispersion so that the same interval.

The present invention also provides a planar heating element produced by the method of the present invention.

In addition, the present invention provides a heating system comprising the planar heating element of the present invention.

In addition, the present invention, the step of printing the planar heating element of the present invention on a glass substrate; And it provides a method of manufacturing a self-generating smart heating glass comprising the step of connecting and laminating the planar heating element and the solar cell printed on the glass substrate.

In one embodiment of the present invention, the printing may be performed by a screen printing method.

In one embodiment of the present invention, after printing the planar heating element on a glass substrate, and dried for 30-40 minutes at a temperature of 130 ~ 170 ℃, after printing the electrode, at 1 ~ 2 hours at 180 ~ 220 ℃ It may be further comprising the step of heat treatment during.

In addition, the present invention provides a self-generating smart heating glass produced by the method of the present invention.

The planar heating element produced by the physical dispersion process according to the present invention has excellent dispersibility and high temperature stability, adhesiveness, and structural stability compared to the conventional planar heating element even without performing a chemical dispersion process without adding a dispersant. In addition, the self-generating smart heating glass manufactured by laminating the planar heating element of the present invention together with a solar cell on a glass substrate has the effect of realizing heat generation even at low voltage, and self-heating is possible with the power generated by sunlight. Therefore, there is an effect that can reduce the power consumption, it can be utilized in various industrial fields.

Figure 1 shows a photograph confirming the form of improved purity by removing the amorphous carbon by heat treatment of the carbon material in one embodiment of the present invention.
2 is a photograph showing a paste manufacturing process of the planar heating element according to the method of the present invention.
Figure 3 shows an embodiment of the present invention, the physical dispersion principle by the three roll mill in the paste manufacturing process.
Figure 4 shows the results of confirming the dispersibility according to the presence or absence of carbon nanotubes, showing the excellent dispersibility in the vertical arrangement structure when adding carbon nanotubes.
5 shows a mask photograph and a screen printing apparatus screen-printing a planar heating element of a paste prepared in one embodiment of the present invention.
Figure 6 shows the form of the planar heating element that can be produced by the method of the present invention.
Figure 7 shows a cross-sectional structure of the self-generating smart heating glass produced by one embodiment of the present invention.
Figure 8 shows the result of analyzing the low power heating rate of the heating glass made of the planar heating element of the present invention.
Figure 9 is a microscopic picture of the microstructure of the planar heating element and the control (planar heating element using carbon black instead of carbon nanotube) planar heating element according to the present invention.
Figure 10 shows the result of comparing the hardness at the glass surface for the heating glass and the control heating glass according to the present invention.
11 is a result of measuring the heat generation possibility (Fig. 11a), heat resistance (Fig. 11b), surface abnormality (Fig. 11c) and power consumption stability (Fig. 11d) for the heating glass and the control heating glass according to the present invention to be.
12 is a result of confirming whether the adhesion improved by the carbon nanotubes (Fig. 12a) and the heat resistance characteristics according to the content of the carbon nanotubes (Fig. 12b).
Figure 13 shows the crystallinity results for the mixture of graphite and carbon nanotubes in one embodiment of the present invention.
Figure 14 shows the results of analyzing the degree of crystallinity and dispersibility according to the graphite diameter and the roll interval in the physical dispersion process of the three roll mill in an embodiment of the present invention.

The present invention is characterized by providing a method for producing a planar heating element of high efficiency compared to the conventional planar heating element. In particular, the planar heating element manufacturing method of the present invention has improved dispersibility using a conventional dispersant and additives, but there was a problem of unstable chemical functional groups at high temperatures.

On the other hand, the method of manufacturing the planar heating element provided by the present invention used a physical dispersion method, not a chemical dispersion method, excellent dispersibility and stable even at high temperatures without the use of a dispersant, hardness, power consumption, adhesion, crystallinity and exothermic All of these have characteristics that can produce an excellent planar heating element.

Specifically, the method for producing a planar heating element according to the present invention comprises the steps of: heat treating a carbon material; And adding and mixing the polyimide polymer to the heat-treated carbon material, and then performing impeller dispersion and 3 roll mill dispersion to sequentially prepare a paste.

In the present invention, the carbon material is not limited thereto, but any one or more selected from the group consisting of graphite, carbon fiber, carbon nanofiber, and carbon nanotube may be used, and the carbon nanotube is not limited thereto. However, single walled carbon nanotubes (SWNT), double-walled carbon nanotubes (DWNT), thin multi-walled carbon nanotubes and multi-walled carbon nanotubes ( multi-walled carbon nanotube, MWNT) may be any one selected from the group consisting of.

Preferably, the carbon material may be used in a mixed form of graphite (graphite) and carbon nanotubes, and when using them, the graphite and carbon nanotubes are preferably used in a weight ratio of 90: 5 to 95: 1.

In particular, the planar heating element according to the present invention includes carbon nanotubes, the adhesion and structural stability is improved due to the addition of carbon nanotubes. On the other hand, the mixing of graphite and carbon nanotubes is important to mix in a weight ratio of 90: 5 ~ 95: 1, if outside the above range, the problem that the heat resistance is reduced and the resistance is increased occurs an embodiment of the present invention It was confirmed through.

The heat treatment may be performed for 1 to 2 hours at 1,000 ℃ ~ 1,200 ℃ by inducing vacuum at a high frequency, in one embodiment of the present invention was performed for 1 hour at 1,000 ℃.

Through the heat treatment process, the amorphous carbon of the carbon material is removed and the purity can be improved to improve the crystallinity and thus the resistance of the initial material can be reduced.

 When the heat treatment of the carbon material is completed, the polyimide polymer is added to and mixed with the heat-treated carbon material, and then impeller dispersion and three roll mill dispersion are sequentially performed to prepare a paste.

At this time, the polyimide polymer is added to the carbon material so that the mixing ratio of the carbon material and the polyimide polymer is 6: 4 to 4: 6.

In addition, the planar heating element composition of the present invention is prepared by dispersing a mixture of a carbon material and a polyimide polymer in a two-step dispersion process, the first dispersion is an impeller dispersion process, stirred for 1 to 2 hours at a speed of 600 ~ 800rpm Disperse.

When the primary dispersion process is completed, the dispersion process using a three roll mill (3 roll mill) is performed, wherein the interval between the rolls is adjusted to be the same interval as the diameter of the carbon material, and then performed.

In particular, the present invention is an optimal condition for the production of a planar heating element having excellent dispersibility and excellent crystallinity, such that the spacing between rolls is equal to the diameter of the carbon material during physical dispersion by a three roll mill. It was found for the first time that it is important, according to one embodiment of the present invention, when the diameter of the carbon material graphite is larger than the roll interval, it was confirmed that there is a problem that the crystallinity is broken, the dispersibility is broken, the graphite diameter When smaller than this roll interval, agglomeration occurred and it was shown that dispersibility was significantly reduced. On the other hand, when the graphite diameter and the roll interval were the same, it was confirmed that the dispersibility was excellent and the crystallinity was also excellent.

Therefore, when performing dispersion treatment using a 3 roll mill, the diameter of the carbon material and the interval between the rolls must be performed.

In addition, during the physical dispersion by the three roll mill, the speed of each roll is performed while maintaining 1 (draw roll): 3 (middle roll): 9 (scraper roll).

3 The physical dispersion by the roll mill causes shear force due to the roll rotation ratio, graphite is slid and mixed, and carbon nanotubes are attracted and dispersed on the graphite surface. That is, graphite is dispersed while sliding, and carbon nanotubes are dispersed on the surface of graphite by repulsive force caused by van der Waals forces.

  As described above, the second dispersion-processed paste may be used for a planar heating element, and the present invention may provide a heating system including the planar heating element of the present invention.

In one embodiment of the present invention was produced a heating glass using a planar heating element, the heating glass according to the present invention is a self-generating smart heating produced by printing the planar heating element of the present invention on a glass substrate, and laminated with a solar cell It is glass.

Preferably the method of manufacturing a self-generating smart heating glass according to the present invention, the step of printing the planar heating element of the present invention on a glass substrate; And connecting and laminating the planar heating element and the solar cell printed on the glass substrate.

The printing is not performed by sequentially depositing planar heating elements on a glass substrate, but by screen printing at a time.

By using screen printing techniques, productivity can be improved and large area uniformity can be achieved.

In addition, after printing the planar heating element on a glass substrate, the step of drying for 30-40 minutes at a temperature of 130 ~ 170 ℃, printing the electrode, and then heat-treated at 180 ~ 220 ℃ for 1 hour to 2 hours It may further include.

Thus, the planar heating element and the electrode on the glass substrate can be printed by screen printing, in consideration of aesthetics can be printed in a variety of patterns. For example, the screen printing may be performed in various patterns according to the purpose such as interior pattern type or picture type.

In addition, since the electrode printed on the glass substrate may form heat generation in the resistor between the electrodes, in consideration of this, it is possible to induce heat generation by forming an electrode gap of some form.

The self-generating smart heating glass of the present invention manufactured by the above method can implement heat at low voltage, low voltage of 12V or less, and can self-heat with power generated from a solar panel laminated with a planar heating element.

In addition, the self-generating smart heating glass of the present invention can use the home power of 220V in the evening after sunset, the ON-OFF switch is equipped with the ON-OFF switch rather than the use of the heating window in the season when heat is unnecessary, such as summer Power can be converted from to a receptacle to reduce household power usage and can be used in all seasons, both summer and winter.

Self-generating smart heating glass produced by the method of the present invention can be applied to a variety of industries, such as heating glass partition, heating glass desk, heating heating frame, heating glass of the bus stop, heating table, heat-resistant outer wall heating glass It can be used in various ways.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are intended to illustrate the present invention more specifically, but the scope of the present invention is not limited to these examples.

<Example 1>

Preparation of self-generating smart heating glass according to the present invention

The present inventors proceeded in the order of heat treatment process, dispersion process, screen printing process, connection with the solar cell and lamination process for manufacturing a planar heating element for manufacturing the self-generating smart heating glass of the present invention, Same as

Heat treatment process

Graphite (diameter 5um) and multi-walled carbon nanotubes (MWCNT, several nanometers in diameter, 100um in length) are used as raw materials for the planar heating element to remove amorphous carbon through heat treatment to improve the purity of carbon to improve crystallinity. To make it possible. At this time, the heat treatment induces vacuum at high frequency to heat the graphite (HC905) and carbon nanotubes (CM280) for 1 hour at 1,000 ℃, to improve the adhesion and structure of the paste prepared by the addition of carbon nanotubes. .

As a result of observing the state of the carbon materials according to the present invention in which the amorphous carbon was removed by the heat treatment under a microscope, the crystallinity of the carbon materials was improved as shown in FIG. 1.

Distributed process

When the heat treatment process is completed, the heat-treated carbon material 60wt% (graphite 95g + MWCNT 1g) and polyimide resin (polyimide resin) was mixed, and the dispersion process was carried out, in the present invention, the physical dispersion is not a chemical dispersion method Only dispersion was performed, and the process was divided into two phases, primary and secondary.

The primary dispersion was carried out using an overhead stirrer and a crushing impeller. The overhead stirrer was subjected to micro grinding and dispersion with stirring for 1 hour at a speed of 600 rpm, and then the secondary dispersion was a three roll mill. (3 roll mill), the roll interval of the three roll mill was set to 10um: 5um in the first cycle, was adjusted to have a interval of 5um: 5um in the second cycle, 3 roll, that is, draw roll (draw roll), middle roll (middle roll) and scraper roll (scraper roll) was carried out at a speed of 1: 3: 9. In particular, the present invention was performed by adjusting the interval between the rolls as described above in the dispersion process by the three roll mill, which causes a problem that the crystallinity is reduced by graphite breakage when the graphite diameter is larger than the roll gap (gap), On the other hand, if the graphite diameter is smaller than the roll gap (gap), there is a problem that the dispersibility is reduced. Thus, the principle of dispersion by the physical method according to the invention of the primary and secondary is shown in FIG.

As described above, the mixture of the carbon material and the polyimide polymer was subjected to the first and second physical dispersion processes, and the dispersion was completed by preparing a paste using a paste mixer, and degassing to remove bubbles. Treatment was carried out. The mixing and defoaming treatment of the paste was performed twice with a paste container rotation: full plate rotation ratio of 2 times at x700: x600, and then once at 1 minute at x700: x100.

The paste prepared by the method according to the present invention was prevented from agglomeration and appeared to have a very good dispersibility, it was confirmed that the dispersion proceeds in a vertical array structure (see Fig. 4), physical dispersion according to the present invention A photograph of a process of preparing a paste by the process is shown in FIG. 2.

Printing process

When the preparation of the paste with uniform dispersion was completed, the planar heating element was printed on the glass surface by printing on the glass substrate using screen printing.

The printing was a screen printing method, and after the completion of printing, dried at 150 ℃ for 30 minutes, then printed the electrode (Ag paste) for 30 minutes at 150 ℃, heat treatment at 200 ℃ for 1 hour all the printing process Completed. In addition, in the present invention, the printing of the heating element and the electrode may be printed in a specific pattern shape or a figure shape in terms of enhancing aesthetics (see FIG. 6).

Solar cell connection and lamination

After connecting the solar cell and the surface heating element screen-printed on the glass substrate in the above, using the adhesive of ethylene vinyl acetate (EVA) laminated the glass and the solar cell, and the charging outlet and on-off switch Mounted to produce a self-generating smart heating glass according to the present invention, the cross-sectional shape of the completed self-generating smart heating glass is shown in FIG.

The heating glass of the present invention manufactured by the above method is capable of self-generation using electricity generated from solar heat due to the lamination of the solar cells, and has a feature that it is possible to realize heat generation at a voltage of 12V or less, and the on-off switch It is equipped to allow customers to control the heat according to the season according to the season.

Experimental Example 1

Low power temperature rise rate analysis

For the self-generating smart heating glass of the present invention prepared by Example 1, the temperature increase rate analysis according to the low power of the planar heating element of the present invention was performed. At this time, as a control, graphite and carbon black planar heating element manufactured by D company manufactured by metal wire and chemical dispersion method were used, and the power supply was analyzed at ambient temperature of 12V, 2A, and -20 ° C.

As a result, as shown in Figure 8 it can be seen that the planar heating element of the present invention has the highest heat generation efficiency at the same voltage and power, in particular, the fastest temperature rise rate of the product of the present invention at the same power 24W, the most marked temperature As shown by the high, the highest efficiency was found.

Experimental Example 2

Microstructure Analysis

The state of the microstructure in the high temperature state of the planar heating element used in Experimental Example 1 was observed using a microscope.

As a result, as shown in Fig. 9, while the heating element of the D company, which is a control group, was observed to have an unstable structure in a high-temperature environment as a resistance reducing paste based on carbon black, the paste prepared by the method of the present invention was used. The heating element was found to be very well dispersed in the carbon nanotubes on the graphite, it was found to have a stable structure even in high temperature environment.

Experimental Example 3

Hardness analysis on the surface of exothermic glass

Hardness analysis was performed on the exothermic glass (exothermic glass vs. exothermic glass according to the present invention) manufactured using the planar heating element used in Experimental Example 1.

As a result, as shown in Figure 10, the hardness of the heating glass produced by the method of the present invention compared to the control was found to be significantly superior.

Experimental Example 4

Analysis of stability at high temperature

Stability at high temperature (ambient temperature) for each heating glass used in Experimental Example 3 was analyzed. To this end, after adjusting the ambient temperature to 30 ℃, 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃, respectively, the initial resistance and the resistance change rate of each heating glass was measured and the results are shown in the table below.

As a result of the analysis, as shown in Table 1 and Table 2, compared to the heating glass of the other company's product, the heating glass produced by the method of the present invention shows that the resistance change rate is significantly low even at high temperature, and the stability at high temperature is very high. Could know. In particular, the high temperature of 80 ℃ is a condition that there is a risk of rise of power consumption and fire due to the heater output rises, it can be seen that the heating glass of the present invention has a high temperature stability due to low resistance even at a high temperature of 80 ℃.

Experimental Example 5

Print and heat test and power consumption stability analysis

An exothermic test and a power consumption stability test were performed on the self-generating smart heating glass manufactured in the present invention. The heat generation temperature was measured in a state where a voltage of 30 V was applied, and heat resistance was measured at a high temperature of 80 ° C., and whether the peeling phenomenon or the surface abnormality was observed after the heat resistance measurement.

As a result, as shown in Figure 11, the heat generating glass of the present invention was shown to generate heat well at about 50.5 ℃ in the state of applying a voltage of 30V (Fig. 11a), the abnormal phenomenon does not occur even at a high temperature of 80 ℃ It was confirmed that there is a high temperature stability (Fig. 11b), it was found that the peeling phenomenon or the abnormal phenomenon does not occur after the heat resistance measurement (Fig. 11c). In addition, the power consumption stability measurement results, as shown in Figure 11d it was shown that the heating glass of the present invention has a more stable power consumption than the control.

Experimental Example 6

Adhesion improvement and heat resistance analysis according to carbon nanotube usage and content

According to Example 1, the planar heating element of the present invention was prepared using graphite (5um in diameter) and carbon nanotubes (MWCNT, diameter of several nm, length of 100um) of carbon material. Therefore, the present inventors analyzed whether the adhesion is improved according to the use of carbon nanotubes and the heat resistance change according to the amount of addition. First, the ASTM group is used for the group of graphite alone (without carbon nanotube addition) and the group using graphite and carbon nanotube together Adhesion test was analyzed by D3359 method.

As a result, as shown in FIG. 12A, the group using graphite and carbon nanotubes together with the polymer was adhered to the high surface area of the carbon nanotubes compared to the graphite alone group, thereby improving adhesion.

In addition, as a result of analyzing the thermal diffusion role of carbon nanotubes, the group without adding carbon nanotubes was found to have a problem in that the structure was destroyed due to a breakdown of the polymer and a rapid rise in the heating element temperature, whereas carbon nanotubes were added. One group was found to maintain temperature stability by preventing temperature condensation and ensuring temperature uniformity.

In addition, the present inventors produced a heating element by varying the content of graphite and carbon nanotubes in the above embodiment (① graphite 32.5wt%: carbon nanotube 0.3wt%, ② graphite 32.3wt%: carbon nanotube 1.0wt %, ③ graphite 33.0wt%: carbon nanotube 1.0wt%) Its heat resistance was measured, the resistance reduction rate was analyzed by 30 minutes ON, 15 minutes OFF 264V voltage applied in the accelerated durability 80 ℃ dryer. As a result, as shown in FIG. 12B, the group of carbon nanotubes added with 1.0 wt% showed a lower resistance reduction rate than the group added with 0.3 wt%, which was found to be excellent in heat resistance.

Experimental Example 7

Crystallinity analysis

The present inventors analyzed the crystallinity and dispersibility of the mixture of graphite and carbon nanotubes as a raw material of the heating element prepared in Example 1 of the present invention using Raman spectroscopy. In this case, a group treated with graphite and carbon nanotubes alone was used as a control.

As a result of the analysis, as shown in Table 3 and FIG. 13, after mixing the graphite and carbon nanotubes, the D-band was found to be offset and formed low, and 60 wt% of the carbon material according to Example 1 of the present invention (graphite 95g + MWCNT 1g) was found to have a D / G ratio of 0.3.

Experimental Example 8

3 On a 3 roll mill  Graphite in the dispersion process by Diameter and  Crystallinity and Dispersibility Analysis by Roll Thickness

 As described in Example 1, in the planar heating element manufacturing process for producing a heating glass of the present invention, during the heating element dispersion process by a three-roll mill as a physical method, to determine whether the control of graphite diameter and roll spacing is an important factor The same experiment was performed. That is, three roll mills were performed with different graphite diameters and roll intervals as shown in the following table, and the dispersibility was measured by surface analysis (crystallization analysis) and Raman spectroscopy analysis on the manufactured heating elements.

* Experiment with 60 wt /% carbon (95 g graphite: 1 g MWCNT) with a base D / G ratio of 0.3

As a result, as shown in Table 4 and Figure 14, when the graphite diameter and the roll interval deviated from the same conditions, it was found that the problem of crystallinity, such as crystallinity is broken or agglomeration occurs, and dispersibility is also good It was found that it was not possible, for the production of a heating element having excellent crystallinity and dispersibility, it was found that the best manufacturing conditions were to perform physical dispersion by adjusting the graphite diameter and the roll interval to be the same.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Claims (12)

Heat treating the carbon material; And
After the polyimide polymer is added to and mixed with the carbon material after the heat treatment is completed, impeller dispersion and 3 roll mill dispersion (sequentially performing a 3 roll mill) includes the steps of preparing a paste,
The carbon material is a mixture of graphite and carbon nanotubes, and the graphite and carbon nanotubes are mixed in a weight ratio of 90: 5 to 95: 1,
The mixing ratio of the carbon material and the polyimide polymer is 6: 4 to 4: 6,
The impeller dispersion is to disperse with stirring for 1 to 2 hours at a speed of 600 ~ 800rpm,
The 3 roll mill dispersion is controlled so that the interval between the rolls is equal to the diameter of the graphite, and the speed of each roll is maintained at 1 (draw roll): 3 (middle roll): 9 (scraper roll). Characterized in that while performing,
Method for producing a planar heating element excellent in dispersibility, high temperature stability and crystallinity. delete delete The method of claim 1,
The heat treatment is a method of producing a planar heating element excellent in dispersibility, high temperature stability and crystallinity, characterized in that heat treatment for 1 to 2 hours at 1,000 ℃ ~ 1,200 ℃ by inducing vacuum at a high frequency. delete delete The planar heating element excellent in dispersibility, high temperature stability and crystallinity prepared by the method of claim 1. Heating system comprising the planar heating element of claim 7. Printing the planar heating element of claim 7 on a glass substrate by a screen printing method; And
Connecting and laminating the planar heating element and the solar cell printed on the glass substrate,
Method for producing self-generating smart heating glass that can generate heat at low voltage. delete The method of claim 9,
After printing the planar heating element on a glass substrate, further drying for 30 to 40 minutes at a temperature of 130 ~ 170 ℃, printing the electrode, and further heat-treated at 180 ~ 220 ℃ for 1 hour to 2 hours Method for producing a self-generating smart heating glass capable of heating at low voltage, characterized in that. Self-generated smart heating glass capable of heating at low voltage manufactured by the method of claim 9.

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