KR101543233B1 - Film Heater With PTC Properties and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a heating film with superior automatic temperature control characteristics. The heating film comprises: a first flat panel in the shape of a square panel; a plurality of carbon bands which are installed on the upper surface of the first flat panel in the vertical direction to be spaced apart at predetermined intervals in the shape of a long rectangular band; a pair of vertical electrodes which are silver paste electrodes or copper (Cu) thin film electrodes, installed to be spaced apart at predetermined intervals in the direction of one end of the first flat panel, in a first or a last carbon band among the carbon bands; a plurality of horizontal electrodes which are silver paste electrodes or copper (Cu) thin film electrodes, installed to be perpendicular to the longitudinal direction of one vertical electrode between the vertical electrodes, in which one end thereof is connected to the vertical electrodes and the other end thereof crosses the carbon bands and is configured not to be connected to another vertical electrode after crossing the last carbon band; copper panels installed on the vertical electrodes to be overlapped respectively by the same length; and a second flat panel which has the same size as that of the first flat panel and stacked by corresponding to the upper surface of the first flat panel and comprises an insulating layer stacked to include the carbon band, the vertical electrodes, the horizontal electrodes, and the copper panels therein. The heating film has PTC efficiency greater than or equal to 400% across the entire area.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating film,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating film having excellent automatic temperature control characteristics, and more particularly, to a heating film for controlling temperature by independent cells using a heat generating material exhibiting PTC characteristics.

In general, the positive temperature coefficient, that is, the PTC (positive temperature coefficient) characteristic, indicates that the resistance value rises with temperature rise and the temperature function of the resistance is positive.

The carbon-polyethylene-based polymer mixed material having the above-mentioned PTC characteristics has a temperature range that varies depending on the amount of heat generated. Since the resistance value increases at a high temperature, the material exhibits characteristics of preventing excessive temperature rise and overheating by heat, And is used as a thin surface heating element for floor heating.

The surface heating element is a material which inserts a thin electrode at both ends by inserting a thin electrode at the both ends and connects the power supply and generates heat due to the supplied current and the resistance component of the material. It is excellent in flexibility and generates heat evenly across two- (Floor, wall, ceiling, etc.) and industrial heater parts as a heat source for the next generation heating device that can obtain economical and environment-friendly effect by replacing fossil energy.

The surface heating element mainly controls the temperature by an electric control method using a temperature sensor. That is, when a planar heating element is applied to a floor heating system, a method of adjusting the temperature of a heating element is a method in which a temperature sensor (thermistor, bimetal, etc.) is attached to the surface of a heating element and the temperature of the heating element is measured, I am using it.

However, this is a method of controlling the temperature of the entire system based on the value of the temperature of the surroundings of the sensor, and there is a possibility that some parts except the sensor part are accumulated (collected), causing damage to the finish material and the product. That is, since the heating element is controlled by measuring only the temperature at the position where the temperature sensor is located, a significant temperature difference may occur between the vicinity of the temperature sensor and the vicinity of the temperature sensor depending on the degree of external heat insulation and the ambient temperature. If a product that has a property to block heat emitted from a bed or a cushion is placed for a long time, the temperature may suddenly increase as compared with the ambient control temperature, which may result in deterioration of the performance of the product or damage to the finish material.

Therefore, the surface heating element using the PTC characteristic is applied to the heating film in order to prevent excessive temperature rise due to heat collection and to save energy by suppressing overheating.

For example, in Korean Patent Registration No. 10-1180037, a heating film having a structure in which a plurality of carbon yarns and a silver paste are crossed is used to break the heating film caused by heat collection and to eliminate power wastage.

In Korean Patent Laid-Open Publication No. 10-2009-0005760, a carbon paste composition having a self-switching function is applied to a surface heating element, and when the temperature is over a certain temperature, the resistance value of the carbon resistor increases due to a phase change inside the carbon resistor, .

The most important factor that influences the quality of the surface heating element such as the heating film is PTC efficiency (PTC intensity). The PTC efficiency is defined as the peak resistance value for the resistance value at room temperature in Reveiw of Advanced Material Science, 27, 173-183 (2011). In view of the fact that the PTC effect is caused by the phase change at the melting point (Tm) of the polymer material, the PTC efficiency corresponds to the rate of increase of the resistance value at the melting point of the polymer material with respect to the resistance at room temperature have.

The PTC efficiency can be varied depending on various factors such as the composition of the conductive composition, the softening point of the polymer, the volume expansion rate, the size and the content of the carbon particles, and it is possible to maximize the value of 10 ^{3 by} optimizing the polymer crystallinity. However, when the conductive composition is applied to a heating film, the PTC efficiency is less than 100%, and the problem of local heating of the heating film during the heating is not solved.

Korean Patent Publication No. 10-1180037 Korean Patent Publication No. 10-2009-0005760

Reveiw of Advanced Material Science, 27, 173-183 (2011)

The present invention has been proposed in order to solve the above problems. It is an object of the present invention to enhance the automatic temperature control characteristic of a heating film through a heating film having a high PTC efficiency and a manufacturing method thereof and to prevent local heating, And a method of manufacturing the same.

In order to achieve the above object, the heating film excellent in the automatic temperature control characteristic of the present invention comprises a first flat plate having a rectangular plate shape; A plurality of carbon bands extending in a direction perpendicular to the upper surface of the first flat plate and spaced apart from each other at regular intervals; A pair of vertical electrodes, each of which is a silver paste electrode or a copper (Cu) thin film electrode, spaced apart from the first and the last carbon bands of the plurality of carbon bands by a predetermined distance in the direction of one end of the first flat plate; The vertical electrodes are provided perpendicular to the longitudinal direction of one of the pair of vertical electrodes, one end of which is connected to the vertical electrode, the other end of which crosses the plurality of carbon bands, A plurality of horizontal electrodes, each of which is a silver paste electrode or a copper (Cu) thin film electrode, A copper plate installed on the pair of vertical electrodes so as to overlap with each other at the same length; And a second flat plate having the same size as that of the first flat plate and stacked so as to coincide with the upper surface of the first flat plate, wherein the insulating layer is stacked such that the carbon band, the vertical electrode, the horizontal electrode and the copper plate are included And the heating film has a PTC efficiency of 400% or more over the entire area.

Further, the interval between one horizontal electrode and the adjacent horizontal electrode is 0.1 to 25 cm, and the width of the carbon band is 0.1 to 25 cm.

In addition, the carbon band is formed from a composition comprising carbon particles, which are carbon nanotubes, carbon black, graphite, or a combination thereof, and a crystalline polymer having a crystal melting temperature of 80 to 105 ° C, A polyolefin-based polymer or copolymer, an ethylene vinyl acetate polymer or copolymer, a polyester-based polymer, or a copolymer. Further, the ratio of the crystalline volume coefficient of thermal expansion of the polymer is from 10 to 20 × 10 ^-5 cm / ℃, the content of carbon in the overall composition of the average particle diameter (nm) of the carbon particles (% by weight) is 0.02 to 0.3 .

A method of manufacturing a heating film having an automatic temperature control characteristic of the present invention includes the steps of forming a horizontal electrode and a vertical electrode made of a silver paste or a copper thin film on a base film; Applying a carbon ink to a base film on which the horizontal electrode and the vertical electrode are formed; And forming an insulating layer on the base film coated with the carbon ink or simultaneously forming a copper plate and an insulating layer.

At this time, the formation of the horizontal electrode and the vertical electrode, and the application of the carbon ink are performed by performing either one of roll-to-roll rotary screen printing or roll-to-roll rotary gravure printing or a combination of the two and the insulating layer is made of polyethylene terephthalate (PET), polyethylene (PE), and ethylene-vinyl acetate copolymer (EVA).

Since the heating film having excellent automatic temperature control characteristics of the present invention exhibits excellent PTC characteristics with a PTC efficiency of 400% or more, it has an energy saving effect by preventing excessive temperature rise due to heat accumulation and suppressing overheating, The characteristics can be clearly shown.

1 is a perspective view showing a heating film according to an embodiment of the present invention.
2 is a perspective view showing a heating film according to another embodiment of the present invention.
3 is a conceptual diagram showing the principle of the PTC characteristic.

Hereinafter, a heating film having excellent automatic temperature control characteristics according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a plan view showing a heating film having excellent automatic temperature control characteristics according to an embodiment of the present invention.

The heating film (10) of the present invention comprises a first flat plate (100) in the form of a rectangular plate; A plurality of carbon strips 200 each having a rectangular strip shape and spaced apart from each other at regular intervals in a direction perpendicular to the upper surface of the first flat plate; A pair of vertical electrodes (350) which are silver paste electrodes spaced a predetermined distance from the first and the last carbon bands of the plurality of carbon bands (200) in the direction of one end of the first flat plate; The vertical electrodes are provided perpendicular to the longitudinal direction of one of the pair of vertical electrodes, one end of which is connected to the vertical electrode, the other end of which crosses the plurality of carbon bands, A plurality of horizontal electrodes (300), which are silver paste electrodes that are installed so as not to be arranged; A copper plate 400 installed on the pair of vertical electrodes so as to overlap with each other at the same length; A horizontal electrode 300, a vertical electrode 350 and a copper plate 400 are stacked in the same plane with the upper surface of the first flat plate with the same size as the first flat plate, And a second flat plate including an insulating layer (500).

That is, in the heating film 10, a silver paste is applied to a first flat plate 100, which is a base film, to form a horizontal electrode and a vertical electrode. On the first flat plate 100 on which the horizontal electrode and the vertical electrode are formed, A plurality of carbon bands 200 are formed by applying ink to the first plate 100 and the insulating layer 500 and the copper plate 400 are simultaneously printed on the first plate 100 to which the carbon ink is applied.

2 is a plan view showing a heating film having excellent automatic temperature control characteristics according to another embodiment of the present invention.

That is, in this embodiment, the vertical electrode 350 and the horizontal electrode 300 are formed of copper thin-film electrodes. Therefore, the heating film 10 according to the present embodiment has a rectangular plate-like first flat plate 100; A plurality of carbon strips 200 each having a rectangular strip shape and spaced apart from each other at regular intervals in a direction perpendicular to the upper surface of the first flat plate; A pair of vertical electrodes (350) which are copper thin film electrodes spaced apart from each other in the direction of one end of the first plate in the first and last carbon strips of the plurality of carbon strips (200); The vertical electrodes are provided perpendicular to the longitudinal direction of one of the pair of vertical electrodes, one end of which is connected to the vertical electrode, the other end of which crosses the plurality of carbon bands, A plurality of horizontal electrodes (300) which are copper thin film electrodes which are not to be installed; An insulating layer 500 stacked to correspond to the upper surface of the first flat plate with the same size as the first flat plate and stacked so that the carbon band 200, the horizontal electrode 300, and the vertical electrode 350 are included therein And a second flat plate including the second flat plate.

That is, the heating film 10 according to the present embodiment is formed by applying a copper thin film to a first flat plate 100, which is a base film, to form a horizontal electrode 300 and a vertical electrode 350, A continuous process of printing the insulating layer 500 on the first flat plate 100 coated with the carbon ink by applying carbon ink on the formed first flat plate 100 to form a plurality of carbon bands 200 Lt; / RTI >

In the heating film 10 according to the present embodiment, since the horizontal electrode 300 and the vertical electrode 350 are all formed of a copper thin film, it is not necessary to provide a separate copper plate, so that the process can be simplified. However, if all the electrodes are made of copper thin film, there is a problem that the material cost rises. Therefore, it is possible to select whether the electrode is made of a silver paste or a copper thin film, if necessary.

In the method for producing a heating film of the present invention, the formation of the horizontal electrode and the vertical electrode and the application of the carbon ink are performed by a roll-to-roll rotary screen printing or a roll-to-roll rotary gravure printing or a combination of both. That is, in the printing method, a different method is applied according to the kind of the material forming the electrodes. For example, in order to form a copper pattern, it is preferable to perform by roll-to-roll rotary screen printing, When a thin film is additionally printed to form a copper plate, it is preferable to perform roll-to-roll rotary gravure printing.

In the case of roll to roll rotary screen printing, repetitive printing of 2 to 10 degrees or more is possible, so that a copper pattern and a carbon ink or paste can be applied to a rolled-up flat plate, and then an insulating layer can be applied and printed.

Further, in the case of roll-to-roll rotary gravure printing, a pattern is formed in the cylinder at an engraved pattern, the ink is filled, the ink in the non-drawn portion is scratched with the doctor blade, the ink in the concave portion is applied as pressure, The copper thin film and the insulating layer can be coated and laminated on the flat plate on which the carbon paste composed of the silver paste electrode and the carbon ink or paste is already formed by one step.

Next, a laminated structure of a heating film according to an embodiment of the present invention will be described with reference to FIG.

The heating film 10 of the present invention is a structure in which a second flat plate including a horizontal electrode and a vertical electrode formed on a first flat plate 100, a plurality of carbon strips 200 formed thereon, and a second flat plate including an insulating layer 500 to be.

In this case, when the vertical electrode is a silver paste electrode, the horizontal electrode and the vertical electrode are formed of the same material layer. However, in order to increase the electrical conductivity of the vertical electrode, the main electrode, .

In the present invention, it is preferable that the first flat plate is made of polyethylene terephthalate. In addition, the insulating layer constituting the second flat plate is formed by laminating three layers of polyethylene terephthalate (PET), polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA).

That is, the insulating layer has a configuration in which a polyethylene layer is disposed for bonding the ethylene-vinyl acetate copolymer and the polyethylene terephthalate, and the horizontal and vertical electrodes and the portion in contact with the carbon band are made of ethylene-vinyl acetate copolymer.

The first and second flat plates of the present invention each have a thickness of about 100 to 500 μm, and the ethylene vinyl acetate copolymer has a thickness of about 50 to 100 μm. Therefore, when the first and second flat plates including the horizontal and vertical electrodes, the carbon strip, and / or the copper plate are laminated together, the ethylene vinyl acetate copolymer is hot-melted and bonded to the first flat plate so that the durability and scratch resistance .

The heating film of the present invention is intended to exhibit automatic temperature control performance using the PTC effect. That is, since the resistance increases as the temperature rises, local overheating of the heating film can be prevented.

As shown in FIG. 3, the principle of the PTC characteristic is that the carbon particles come into contact with each other at a low temperature to generate heat, and when the temperature rises, the crystalline polymer becomes phase- The contact is deteriorated and the resistance value is increased, so that the energization is stopped.

Therefore, the PTC characteristic is determined by factors such as the softening point of the crystalline polymer constituting the carbon ink or the paste, the average particle diameter of the volume coefficient of thermal expansion carbon particles, and the carbon particle content.

However, when the carbon ink or paste is applied to a heating film, the properties of the carbon ink or paste can not exhibit the PTC characteristics alone. This is because of an electrode structure for energizing the carbon ink or paste, a method of disposing the carbon ink or paste, a method of applying the carbon ink or paste to the film, a composition and composition of the carbon ink or paste optimized for the heating film, Or PTC properties that are expressed in the paste itself.

The automatic temperature control performance of such a heating film can be evaluated by PTC efficiency. The PTC efficiency defined in the present invention corresponds to the rate of increase of the resistance value at the melting point of the polymer material with respect to the resistance value at room temperature.

Wherein I (%) is the PTC efficiency, R ^max is the resistance value of the heating film at the Tm of the crystalline polymer, and R ^room is the resistance value of the heating film at ^room temperature.

That is, by comparing the resistance value at the Tm and the resistance value at the room temperature of the crystalline ink constituting the carbon ink or paste of the present invention and measuring the rate of increase of the resistance value to determine the PTC efficiency value, It is possible to manufacture a product that satisfies the requirements for prevention of excessive temperature rise due to heat collection and prevention of overheating.

In the present invention, the heating film has a PTC efficiency of 400% or more over the entire area.

If the PTC efficiency is less than 400%, it is impossible to produce a heating film excellent enough to have the automatic temperature control characteristic on the market due to the overheat suppressing performance, and if the PTC efficiency is less than 400%, the initial defect rate And the service life is greatly reduced.

In order to make the PTC efficiency 400% or more, it is insufficient to improve any specific item. As described above, an electrode structure for energizing a carbon ink or paste, a method for arranging a carbon ink or paste, It is necessary to optimize the design and the process so as to satisfy various factors such as the method of applying to the film, the composition and composition of the carbon ink optimized for the heating film, and the paste.

The present inventor has accomplished its optimization through various experiments in order to apply such PTC characteristics to a heating film.

That is, in order to exhibit the automatic temperature control characteristic through the PTC characteristic of the present invention, the interval between one horizontal electrode and the adjacent horizontal electrode is 0.1 to 25 cm, the width of the carbon band should satisfy 0.1 to 25 cm, Preferably in the range of 1 to 15 cm, respectively. The PTC efficiency of the heating film can not exceed 400%, and the durability and lifetime of the heating film are also rapidly reduced. .

The carbon ink or paste used for printing the carbon bands in the present invention is a composition comprising carbon particles and a crystalline polymer having a crystal melting temperature of 80 to 105 캜.

The carbon particles to be applied to the composition may be any one or a combination of carbon nanotubes, carbon black, and graphite. When the carbon nanotubes are used as the carbon nanotubes, the average particle diameter for optimizing the conductivity should be in the range of 20 to 40 nm, the carbon black should be in the range of 10 to 100 nm, and the graphite should be in the range of 10 to 100 μm. In the case of mixing two or more kinds of carbon nanotubes, carbon black and graphite, the mixing range should be optimized by measuring the PTC efficiency value of the produced heating film. For example, when mixing carbon nanotubes and carbon black It is preferable that the range of 0.1 to 1: 0.1 to 1 in terms of weight ratio is suitable, and in the case of carbon black and graphite having a large average particle diameter difference, the range of 0.5 to 1: 0.1 to 1 is preferable.

In addition, since PTC characteristics are important factors such as particle diameter, dispersion degree, and content of carbon particles, the PTC efficiency varies depending on the content of carbon particles with respect to the average particle diameter of carbon particles. As a result of various experiments, the present inventors have found that the ratio of the content (% by weight) of carbon in the whole composition to the average particle diameter (nm) of carbon particles is in the range of 0.02 to 0.3 to achieve the PTC efficiency required in the present invention .

That is, when the ratio of the content (% by weight) of carbon in the entire composition to the average particle diameter (nm) is less than 0.02, the conductivity at low temperature is not as high as desired and the low temperature resistance is large. It is found that the resistance value increases before the melting temperature of the polymer, resulting in a PTC efficiency of less than 400%.

The crystalline polymer to be applied to the carbon ink or paste composition of the present invention is any polymer that satisfies the characteristics of a crystal melting temperature of 80 to 105 ° C and a volume thermal expansion coefficient of 10 to 20 × 10 ^-5 cm / But it is preferable to use any one or more of a polyolefin-based polymer or copolymer, an ethylene vinyl acetate polymer or copolymer, a polyester-based polymer or a copolymer. In the case of using a mixture, this is the case where only one kind of polymer can not satisfy the crystal melting temperature range required in the present invention. In such a case, a mixture of two or more kinds can be used as a crystalline polymer mixture corresponding to the crystal melting temperature range of the present invention.

HURREN 14LWP (Tm: 81 ° C), HADREN 16LP (Tm: 54 ° C) of TOYOBO, AUROREN 351S (Tm: 65-75 ° C) of NIPPON PAPER, SURLYN 8670 (Tm: 90 ° C) of DUPONT Co., Ltd. as the polyolefin- POLYTAIL H (Tm: 60 占 폚) manufactured by MITSUBISHI CHEM is used as the ethylene vinyl acetate copolymer, and LOTARDER3300 (Tm: 98 占 폚), 3410 (Tm: 91 占 폚) and PVDF9301 EVA 1540 (Tm: 47 ° C), 1834 (61 ° C) and GO3020E (Tm: 64-71 ° C) manufactured by Lotte Chemical Co., Ltd. can be cited as examples of ELVAX 40W, 150 and 260, Hanwha Chemical Co., BYRON GA-6300 (Tm: 100 캜), GA-6400 (Tm: 96 캜), BYRON 103, BYRON 200, SKYBON ES-100, ES-300, ES- 135 ° C), LP-035 (Tm: 83 ° C) and TP-249 (Tm: 95 ° C) of NICHIGO POLYESTER. In addition, DMPA POLYOL BA-0132 (Tm: 60-70 ° C) manufactured by GEOCHEM Corporation may be used as the polyol polymer, ELVACITE 2013 and 2044 manufactured by ELVACITE as acrylic resin. Also, one or more of the above polymers may be used in combination so that the Tm is 80 to 105 ° C.

The carbon ink or paste is divided into an ink or a paste according to the content of the solvent, and any one of them can be appropriately selected depending on the conditions of the printing process. However, it is preferable that the carbon ink or paste is produced in a range of 10 to 50 parts by weight of carbon, 50 to 90 parts by weight of a composition containing a crystalline polymer, 50 to 200 parts by weight of a solvent and 1 to 20 parts by weight of various additives .

At this time, the composition containing the crystalline polymer may be a mixture of polyester, ethylene vinyl acetate, and a crystalline polymer, and may be used alone as a crystalline polymer.

Hereinafter, the present invention will be described in more detail with reference to examples. These embodiments are for purposes of illustration only and are not intended to limit the scope of protection of the present invention.

(%) Of the consumed electric power (watt / m 2) per square meter of the resistance value (Ω) of the heating film 10 of the present invention per square meter and the consumed electric power per square meter (watt / ) Were measured. At this time, the rate of change of the power consumption was measured by measuring the rate of change when the temperature controller was attached to the electrode of the heating film and the temperature was maintained at 40 ° C for 10 hours by applying 220V.

In the present embodiment and the comparative example below, the horizontal electrode and the vertical electrode were formed of silver paste, and the heating film having the copper plate was subjected to the test evaluation. After 100 parts by weight of the polyolefin resin composition was dissolved in 200 parts by weight of an aromatic hydrocarbon solvent (Aroma # 200), 40 parts by weight of carbon black (Denka Black, Japan, average particle diameter: 100 nm) And 5 parts by weight of Coupling Agent (LICA 38, KENRICH) were added to the mixture. The mixture was stirred for 30 minutes, left for 1 day, and dispersed in a 3-roll mill.

Power Consumption: AC 220V

Size of the first flat plate: 1 m 2 (0.5 m 2 m)

Carbon band width: 2cm

Number of carbon bands: 14

Horizontal electrode spacing: 5 cm

As a result of measurement, when the both ends of the vertical electrode were measured, the resistance at room temperature (25 DEG C) was 202 OMEGA, and the resistance at Tm (85 DEG C) was 813 OMEGA.

(Average particle diameter of carbon particles: 80 nm, content of carbon particles of 15 wt% with respect to the entire carbon paste) of the content (wt%) with respect to the average particle diameter (nm) of carbon particles, Test evaluation was carried out under the same conditions as in Example 1. [

As a result of measurement, when the both ends of the vertical electrode were measured, the resistance at room temperature (25 DEG C) was 212 OMEGA, and the resistance at Tm was 852 OMEGA.

(Average particle diameter of carbon particles: 500 nm, content of carbon particles of 10 wt% with respect to the entire carbon paste) of the content (wt%) with respect to the average particle diameter (nm) of carbon particles was 0.02 Test evaluation was carried out under the same conditions as in Example 1. [

As a result of measurement, when the both ends of the vertical electrode were measured, the resistance at room temperature (25 DEG C) was 205 OMEGA, and the resistance at Tm was 831 OMEGA.

[Comparative Example 1]

In the production of carbon paste, 100 parts by weight of ethylene butyl acrylate was dissolved in 200 parts by weight of aromatic hydrocarbon solvent (Aroma # 200), 40 parts by weight of carbon black (Denka Black, Japan, average particle diameter 100 nm) (LICA 38, KENRICH) were added and mixed. The mixture was stirred for 30 minutes, allowed to stand for 1 day, and dispersed in a 3-roll mill.

Power Consumption: AC 220V

Size of the first flat plate: 1 m 2 (0.5 m 2 m)

Carbon band width: 2cm

Number of carbon bands: 14

Horizontal electrode spacing: 5 cm

 As a result of measurement, when the both ends of the vertical electrode were measured, the resistance at room temperature was 250 OMEGA, and the resistance at Tm was 382 OMEGA.

[Comparative Example 2]

(Average particle diameter of carbon particles: 80 nm, content of carbon particles of 15 wt% with respect to the entire carbon paste) of the content (wt%) with respect to the average particle diameter (nm) of carbon particles, Test evaluation was carried out under the same conditions as in Comparative Example 1. < tb > < TABLE >

As a result of measurement, when the both ends of the vertical electrode were measured, the resistance at room temperature was 238 OMEGA, and the resistance at Tm was 378 OMEGA.

[Comparative Example 3]

(Average particle diameter of carbon particles: 500 nm, content of carbon particles of 10% by weight with respect to the whole carbon paste) of the content of carbon particles with respect to the average particle diameter (nm) of carbon particles (wt%) was 0.02 , The test was carried out under the same conditions as in Comparative Example 1. [

As a result of measurement, when the both ends of the vertical electrode were measured, the resistance at room temperature was 234?, And the resistance at Tm was 386 ?.

[Comparative Example 4]

In the production of carbon paste, 100 parts by weight of nitrocellulose was dissolved in 200 parts by weight of butyl cellosolve acetate, 40 parts by weight of carbon black and 5 parts by weight of Coupling Agent (LICA 38, KENRICH) were added and mixed. And then dispersed in a 3-roll mill.

Power Consumption: AC 220V

Size of the first flat plate: 1 m 2 (0.5 m 2 m)

Carbon band width: 2cm

Number of carbon bands: 14

Horizontal electrode spacing: 5 cm

 As a result, the resistance at room temperature was 230 OMEGA, and the resistance value at 105 DEG C was measured because the Tm was too high, indicating that the resistance was 240 OMEGA.

The test results are shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 PTC Efficiency (%) 402.5 401.9 405.4 152.8 158.8 164.9 4.34 Power consumption
Rate of change (%) 44.7 44.6 45.0 17.0 17.6 18.3 0.48

Comparative Example 1 in which the distance between the horizontal electrodes was widened, Comparative Example 2 in which the content (wt%) with respect to the average particle diameter (nm) of the carbon particles were different from those in Examples 1 to 3, Comparative Example 3 in which the carbon content and the interval of the horizontal electrodes were different did not show the PTC efficiency required in the present invention. In particular, in the case of a heating film made of a carbon paste using a conventional polymer rather than a crystalline polymer as in Comparative Example 4, the heating film using the PTC characteristic can not be manufactured because the PTC efficiency is extremely small and the rate of change in the power consumption is low .

In addition, when the PTC efficiency is less than 400%, the power consumption change rate does not show a sufficient amount of power consumption to be applied to the heating film, so that the effect of reducing the heat generation is not sufficient.

10: heating film 100: first flat plate
200: carbon strip 300: horizontal electrode
350: vertical electrode 400: copper plate
500: insulating layer

Claims (11)

As a heating film having an automatic temperature control characteristic,
A first flat plate having a rectangular plate shape;
A plurality of carbon bands extending in a direction perpendicular to the upper surface of the first flat plate and spaced apart from each other at regular intervals;
A pair of vertical electrodes spaced apart from each other in the direction of one end of the first flat plate in the first and last carbon strips of the plurality of carbon strips;
The vertical electrodes are provided perpendicular to the longitudinal direction of one of the pair of vertical electrodes, one end of which is connected to the vertical electrode, the other end of which crosses the plurality of carbon bands, A plurality of horizontal electrodes provided so as not to overlap with each other;
And a second flat plate having the same size as that of the first flat plate and stacked so as to coincide with the upper surface of the first flat plate, wherein the insulating layer is stacked such that the carbon band, the vertical electrode, the horizontal electrode and the copper plate are included In addition,
Wherein the heating film has a PTC efficiency of 400% or more over the entire area. The method according to claim 1,
Wherein the vertical and horizontal electrodes are silver paste electrodes or copper (Cu) thin film electrodes. The method of claim 2,
Further comprising a copper plate provided on the pair of vertical electrodes so as to overlap with each other at the same length when the vertical electrode and the horizontal electrode are silver paste electrodes. The method according to claim 1,
Wherein the gap between one horizontal electrode and the adjacent horizontal electrode is 0.1 to 25 cm, and the width of the carbon band is 0.1 to 25 cm. The method according to claim 1,
Wherein the carbon strip is formed from a composition comprising carbon particles and a crystalline polymer having a crystal melting temperature of 80 to 105 占 폚. The method of claim 5,
Wherein the crystalline polymer is any one or more of a polyolefin-based polymer or copolymer, an ethylene vinyl acetate polymer or a copolymer, a polyester-based polymer, or a copolymer. The method of claim 5,
Wherein the carbon particles are a combination of one or more of carbon nanotubes, carbon black, and graphite. The method of claim 5,
Wherein the ratio of the content (% by weight) of carbon in the entire composition to the average particle diameter (nm) of the carbon particles is 0.02 to 0.3. A first flat plate having a rectangular plate shape;
A plurality of carbon bands extending in a direction perpendicular to the upper surface of the first flat plate and spaced apart from each other at regular intervals;
A pair of vertical electrodes spaced apart from each other in the direction of one end of the first flat plate in the first and last carbon strips of the plurality of carbon strips;
The vertical electrodes are provided perpendicular to the longitudinal direction of one of the pair of vertical electrodes, one end of which is connected to the vertical electrode, the other end of which crosses the plurality of carbon bands, A plurality of horizontal electrodes provided so as not to overlap with each other;
And a second flat plate having the same size as that of the first flat plate and stacked so as to coincide with the upper surface of the first flat plate, wherein the insulating layer is stacked such that the carbon band, the vertical electrode, the horizontal electrode and the copper plate are included Wherein the heating temperature of the heating film
Forming a horizontal electrode and a vertical electrode by applying silver paste to the first flat plate;
Forming a plurality of carbon strips by applying a carbon ink on a first flat plate on which the horizontal electrode and the vertical electrode are formed;
And simultaneously printing an insulating layer and a copper plate on the first flat plate coated with the carbon ink,
Wherein the heating film has a PTC efficiency of 400% or more over the entire area. The method of claim 9,
Characterized in that the formation of the horizontal electrode and the vertical electrode and the application of the carbon ink are performed by a combination of one or both of roll to roll rotary screen printing or roll to roll rotary gravure printing. Way. The method of claim 9,
Wherein the insulating layer is formed by laminating three layers of polyethylene terephthalate (PET), polyethylene (PE), and ethylene-vinyl acetate copolymer (EVA).

Images