KR100411401B1 - Planar resistance heating element - Google Patents

Abstract

Protecting the shape of the predetermined pattern by using an ETCHING resistor on the aluminum thin film of the insulator having the aluminum thin film; Etching away portions not protected with the etch resistor with an etchant; Remove the etch resistor and etchant; Printing to a predetermined shape using carbon paste; Planar heating element manufactured by connecting electrode terminals in parallel to an aluminum thin film.

Compared with the conventional silver paste, the planar heating element has almost no temperature variation, significantly reduces manufacturing costs, and simplifies the manufacturing process, thereby making it easier to remove frost, adhered ice, etc. by attaching the inside of the side mirror of a car. Effect.

Description

Planar heating element and its manufacturing method {PLANAR RESISTANCE HEATING ELEMENT}

The present invention relates to a planar heating element, and more particularly, to protect an aluminum pattern of an insulator having an aluminum thin film by using an etching resistor to protect a shape of a predetermined pattern; Etching away portions not protected with the etch resistor with an etchant; Remove the etch resistor and etchant; Printing to a predetermined shape using carbon paste; The present invention relates to a planar heating element manufactured by connecting electrode terminals in parallel to an aluminum thin film, and a method of manufacturing the same.

Conventionally, planar heating elements using electricity include U.S. Pat. No. 4,330,703, No. 2,59,077 copper, copper No. 2,978,665, No. 3,243,753 copper, copper No. 3,351,882, No. 3,412,358 copper, copper No. 4,034,207, No. 4,777,351 copper, copper No. 4,761,541, No. 4,857,711 copper, copper No. 4,628,187, No. 5,440,425 copper, copper 5155,334, 3,900,654 and 3,848,144, and similar Japanese Unexamined Patent Publications and Utility Model Publications, Japanese Patent Laid-Open Nos. 2-162143, 8-64352, Dongpyeong 6-176857, and Dongpyeong 7 -99083, Dongpyeong 3-261090, and Dongso 55-95203, and JP-A-61-84063, WO-59-40417, and Dongpyeong 3-67904.

Among the above-mentioned prior arts, there is no PTC resistor, which generates current through direct current, and most of the patent rights have expired, and the resistance of the resistor is low, and the ampere is high, which makes it difficult to control the temperature of the heating element.

In addition, applying a current directly to the heating element without a separate electrode has a disadvantage that the electrical conductivity is not uniform.

In addition, most of the electrodes and resistors are made of metal powder such as silver as resin, and then printed on the resin, and as a resistor, carbon is mixed with the resin to be printed, and a current is applied to the electrode to generate heat from the resistor. In this planar heating element, the shape of the electrode is comb-like in order to uniformly transfer heat, or the resistor is in the form of a strip, having a predetermined space on the insulating substrate to improve heat transfer and thermal efficiency. After printing with a silver paste in a pattern, carbon paste may be applied thereon with a print, and classified into a sheet formed so as to cover the portion remaining in the space when printing with the silver paste and the silver paste.

However, the above-mentioned inventions have good conductivity as silver conductors, but since the paste is formulated in a synthetic resin in powder form, the conductivity is poor, moreover, the manufacturing process is complicated and the cost is excessive, so that the development of new planar heating elements is difficult. Has been required.

Accordingly, the present inventors have diligently studied to solve the above problems, and as a result, protect the predetermined shape with an etching resistor on a film of aluminum foil, preferably aluminum deposited on a PET sheet; Using an etchant to etch the portion not protected with the etch resistor; Remove the etch resistor and etchant; The present invention finds that the above problem can be solved by printing the etching portion using a carbon paste, connecting the electrodes in parallel to the aluminum layer, and manufacturing a planar heating element in which the carbon paste layer acts as an electric resistor. To complete.

1 is a cross-sectional view of a planar heating element according to the present invention.

2 is a process chart showing the etching state of the aluminum foil according to the present invention.

3 is a plan view of a state in which the aluminum foil laminated on the PET sheet according to the present invention is etched.

FIG. 4A is a graph showing the change of the current and surface temperature of the specimen 1 at -30 ° C in Test Example 2, and FIG. 4B is a graph of the change of the current and surface temperature at 40 ° C of the specimen 1, FIG. 4c shows a photograph of the change in the state of removal of the surface defrost with the increase of the surface temperature every 2 minutes after the start of energization at −30 ° C. of the test piece 1.

FIG. 5A is a graph showing the change of the current and the surface temperature of the specimen 2 at −30 ° C. in Test Example 2, and FIG. 5B is the graph of the change of the current and the surface temperature of the specimen 2 at room temperature, FIG. 5C. Shows a photograph of the change in the state of removal of the surface defrost with the increase of the surface temperature every 2 minutes after the start of energization at -30 ° C of the specimen 2.

FIG. 6A is a graph showing the change of the current and the surface temperature of the specimen 3 at −30 ° C. in Test Example 2, and FIG. 6B is the graph of the change of the current and the surface temperature of the specimen 3 at room temperature, FIG. 6C. Shows a photograph of the change in the state of removal of the surface frost according to the increase of the surface temperature every 2 minutes after the start of energization at -30 ° C of the specimen 3.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a planar heating element according to the present invention, Figure 2 is a process diagram showing the etching state of the aluminum foil according to the present invention, Figure 3 is a plan view of the state of etching the aluminum foil laminated on the PET sheet according to the present invention. As shown in FIG. 1, the planar heating element 1 of the present invention is an insulating substrate 2, preferably an insulating substrate made of PET sheet, an aluminum foil 3, a carbon paste 4, and a current terminal 5; (5 ').

EMBODIMENT OF THE INVENTION Hereinafter, the surface heating element 1 of this invention is demonstrated in detail with the manufacturing method.

First, referring to FIG. 2, an aluminum sheet laminated on the insulating substrate 2, that is, an insulating sheet formed by vacuum deposition of aluminum on a PET sheet is cut into a predetermined size and shape or manufactured as it is. 2A) Printed on the aluminum foil 3 in a predetermined pattern with an etching resistor 8, for example, a heat etching resistor such as X-77, X-65, AS-500, or UV etching resistor of Daiyo Ink Co., Ltd. Then, it is heated or dried by UV (Fig. 2B printing process).

Then, an acid, for example hydrochloric acid, is injected into the aluminum foil 3 by means of a nozzle, except that the portion protected by the etching resistor 8 is corroded and exfoliated from the insulating substrate 2 (Fig. 2C etching). Process), it is washed with water, and then neutralized with an aqueous alkali solution, for example, 1 to 3% aqueous sodium hydroxide solution to remove the etching resistor 8, washed with water and dried, and then washed with aluminum foil (2) on the insulating substrate (2). Only the electrode pattern consisting of 3) is left. (FIG. 2D washing process) Thereafter, the PTC carbon paste 4 is printed and dried on the electrode pattern made of aluminum foil to prepare a planar heating element (FIG. 2E printing process).

The pattern of the planar heating element of the present invention can be modified for convenience of manufacture, and is not limited to the pattern shown in FIGS. 1 to 3. Meanwhile, as shown in FIG. 3, a predetermined portion of the aluminum electrode formed by corrosion of the aluminum foil 3 is formed. When the current input terminals 5 and 5 'are provided, the electrodes are bisected by the carbon paste 4, and the currents are connected in parallel. In addition, when the planar heating element is large, two pairs of current input terminals may be provided at the longest distance of each electrode.

In the above, the carbon paste 4 which is a resistor is briefly described. Carbon used for a carbon paste will not be specifically limited if it has heat conductivity. That is, since amorphous carbon is inferior in heat transfer property, it is preferable to use the carbon with favorable heat transfer property for commercial use. The thermal conductivity of these carbons is 37.7 × 10 ^-3 deg. cm. As a commercially available thing, Nippon Carbon Co., Ltd. powdery CSP, CP, P5 (all the above brand names), TOKABLACK (trade name) of Nippon Tokai Carbon Co., etc. are mentioned.

Each of these carbons is different in heat transfer property, and its amount can be appropriately selected for adjusting the heat resistance, and the amount used thereof is preferably 10 to 50 parts by weight based on 100 parts by weight of the resin. The resin used in this carbon paste is not particularly limited as long as it is less thermally deformable, easily blended with carbon, adhesive and poorly water soluble. Examples thereof include polyesters, polyacrylates, polyamides, and the like, of which polyester resins are particularly preferred.

The planar heating element manufactured as described above may be used as it is, but in order to facilitate distribution or purchaser use, the adhesive layer 6 is formed by applying an adhesive or double-sided adhesive tape on the carbon paste as shown in FIG. 1. After that, the release paper 7 can be attached.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to these examples.

Example 1

Printed in a predetermined pattern on an insulating sheet (aluminum thickness: 3.0 nm, sheet thickness: 150 µm) on which a commercially available PET film was deposited by using an etching resistor of X-77 (trade name) of Daiyo Ink Co., Ltd. Then, heat drying at 60 ° C. for 20 minutes. Then, when sprayed with 5% hydrochloric acid aqueous solution, the aluminum foil 3 other than the portion protected by the etching resistor is corroded and peeled off. It was washed with water and then again with 2% aqueous sodium hydroxide solution.

A carbon paste was prepared by mixing TOKABLACK (trade name) of Nippon Tokai Carbon Co., Ltd. at 6: 5 (weight ratio) in a solution in which a polyester resin was dissolved in a solvent of butyl cellulsolve acetate at a ratio of 1.4: 1. It prints and apply | coats to the obtained aluminum sheet in thickness of 10 micrometers. In this way, the electrode by the carbon paste layer 4 and the aluminum foil 3 is formed.

After applying the carbon paste layer, a double-sided tape or adhesive layer 6 is formed thereon. In view of industrial production and cost reduction, it is preferable to apply hot malt ethylene vinyl acetate. Then, the planar heating element of the present invention is manufactured by adhering the release paper 7 and attaching the current input terminals 5 and 5 'to the aluminum electrode 3 portion as shown in FIG. 3.

The planar heating element manufactured in this way is extremely efficient to remove frost, ice and frost in a short time, which is useful for a side mirror of a car and a bathroom mirror.

Test Example 1

The following items are tested using the planar heating element produced in Example 1, and the results are shown together.

1. Electrical Characteristics

(1) Rated voltage: DC 13.5V

(2) Operating voltage: DC 10 ~ 15V

(3) Maximum current: AT, -40 ℃, DC 13.5V Initial current: 3.5AMP or less

10 minutes later: 2.2AMP or less

(4) Insulation resistance: 10M or more (500V MEGA)

(5) Over current: It is not damaged or burned by applying DC 15V for 24 hours.

2. Ice removal characteristics of the planar heating element of the present invention

The mirror surface was wiped with ammonia water to remove oil, etc., then washed with distilled water and dried. It was left at -18 ° C for 2 hours. Then, 0.5 mm of ice is uniformly produced on the mirror surface at an air temperature of 25 ° C. 65 ± 10% for 1 hour at -40 ° C., and is left at -40 ° C. for 4 hours, and then left for 30 minutes at each of the following temperatures. DC 13.5V was then applied. the results are as follow.

80% ice removal for 3 to 5 minutes at -5 ° C

80% ice removal for 6 minutes at -25 ° C

Remove 95% ice when energized for 10 minutes at -25 ℃

80% ice removal for 12 minutes at -40 ° C

3. Surface temperature control test of mirror

10 minutes after applying DC 13.5V at -30 ℃, the surface temperature of mirror is over 10 ℃

10 minutes after applying DC 13.5V at 25 ℃, surface temperature of mirror is 55 ℃ ± 10 ℃

10 minutes after applying DC 13.5V at 45 ℃, surface temperature of mirror is below 70 ℃

4. When the surface heating element of the present invention produced in Example 1 was attached to glass and subjected to a temperature exposure test,

There was no more than 24 hours at −30 ° C. to 20 ° C., and no abnormality when energized for 1 hour at 115 ° C.

5. Turn off the power to which the same object as above is applied with DC 15V in air for 10 minutes, immerse in 5% NaCl solution for 5 minutes, 200 cycles with 1 cycle, and use 5% CaCl ₂ solution There was no abnormality in the planar heating element of the present invention.

6. The surface rise temperature, the low temperature operating current, and the normal temperature operating current were tested using the planar heating element of the present invention, and the results are shown in Tables 1 to 3 below. (LH is the left side mirror, RH is the right side mirror, J-95 is one of three domestic cars, H-car is one of three domestic cars, and G-car is a domestic car 3 Represents one of the four midsize cars)

Test Example 2

According to the description of U.S. Patent No. 4,857,711 and a large planar heating element (without a separate resistance heating element) manufactured in Europe (hereinafter referred to as "Test Specimen 1") in which aluminum is connected in series, a silver powder paste is used as an electrode. And a planar heating element (hereinafter referred to as "test piece 2") and a planar heating element (hereinafter referred to as "test piece 3") prepared by using a carbon powder paste as a resistor, were tested under the following conditions. The results are shown in FIGS. 4 to 6.

1) That is, after cooling specimen 1 to -30 ° C. and maintaining it for 30 minutes, it was energized with a current of 24 V and measured the change in current [A] and temperature change every 2 minutes, and the result was measured in FIG. 4A. Indicated. As shown in this figure, the initial current [A] is 2.25A or 1.94A in 11 sentences, and shows the same current even after 20 minutes. This indicates that the temperature control of the planar heating element is very bad since there is almost no change in the resistance value and the current continues to flow constantly. In addition, when the temperature change is seen, the temperature rises to 12.9 ° C. after 11 minutes from the initial −28 ° C. and to about 20 ° C. after 20 minutes, which indicates that the temperature control of the surface heating element is not satisfactory as described above. . 4B shows that the test piece 1 was held at 40 ° C. for 30 minutes, and then it was energized at 24 V at room temperature, and the change in current [A] and the change in temperature were measured every 2 minutes. . Similarly to Fig. 4A, the initial current [A] is 1.68A or 1.60A at 11 minutes, and almost the same current is shown after 20 minutes. This indicates that the temperature control of the planar heating element is very bad since there is almost no change in the resistance value and the current continues to flow constantly. 4C shows that the test piece 1 is sprayed with water at -30 ° C. to form a cake on the mirror surface and held there for 30 minutes, and then start energization at a voltage of 24 V, and the surface freeze with the increase of the surface temperature every 2 minutes. The photo shows the state of removal.

2) After cooling the specimen 2 to -30 ° C. for 30 minutes, the test piece 2 was energized with a current of 24V, and the change of the current [A] and the change of temperature every 2 minutes were measured and shown in FIG. 5A. It was. As shown in this figure, the initial current [A] is 4.83 A, but 2.87 A at 20 minutes. Compared to Test Piece 1, when comparing the initial current with the current after 20 minutes, the current after 20 minutes is considerably lower, indicating that the resistance is increased and the amperage is lowered to facilitate temperature control. In addition, the temperature change also rises to 31.9 ° C. after 20 minutes at −27 ° C., indicating a very good effect. 5B shows the result of the test piece 2 being tested at room temperature. Here too, the initial current is energized to 3.2A, and after 20 minutes, the current drops to 1.70A, resulting in high resistance. Therefore, when the temperature rises, the change in the resistance value becomes large, and a small current flows, thereby preventing the temperature from rising rapidly. FIG. 5C shows that the specimen 2 is sprayed with water at -30 ° C. to form a cake on the mirror surface and maintained therefor for 30 minutes. Then, electricity is supplied at a voltage of 24 V and the surface freeze is caused by a surface temperature increase every 2 minutes. The photo shows the state of removal. This picture shows superiority to Figure 4C.

3) In addition, the test piece 3 of the present invention was cooled to -30 ° C. and held for 30 minutes. Then, the test piece 3 was supplied with a current of 24 V, and the change in current [A] and temperature change every 2 minutes were measured. 6a. As shown in this figure, the initial current [A] is 5.45 A, but 2.76 A at 20 minutes. Compared with the test pieces 1 and 2, when comparing the initial current with the current after 20 minutes, if the temperature rises after 20 minutes, the change in the resistance value becomes considerably large and the current flows less, so that the temperature does not rise and prevents the temperature from rising. Becomes easy. In addition, it can be seen that the temperature change also rises to 34.8 ° C. after 20 minutes at −27 ° C., which is very effective. 6B shows the result of the test piece 3 being tested at room temperature. Here too, the initial current is energized to 3.30A, and after 20 minutes, the current drops to 1.59A, resulting in high resistance. Therefore, the planar heating element of the present invention is easier to control temperature when the temperature rises as compared with the conventional test specimens 2 and 3, since the change in the resistance value becomes considerably large and the current flows less. FIG. 6C shows that the specimen 3 is sprayed with water at -30 ° C. to form a cake on the mirror surface and held there for 30 minutes, and then energization is started at a voltage of 24 V, and the surface freeze with the surface temperature rises every 2 minutes. The photo shows the state of removal. This picture shows superiority compared to FIGS. 4C and 5C.

As shown in the above Examples and Test Examples, the planar heating element of the present invention has a uniform conductivity and excellent heating effect compared to the planar heating element according to the prior art, it is possible to easily and cheaply produce a planar heating element.

Compared with the conventional silver paste, the planar heating element of the present invention has almost no temperature variation, significantly reduces manufacturing costs, and simplifies the manufacturing process to be attached to the inside of the side mirror of an automobile, which is excellent in removing frost and ice. Effect.

Claims (4)

delete delete Printing (B) the etching resistor 8 in a predetermined pattern on the aluminum foil 3 laminated on the insulating substrate 2; Spraying an etchant to corrode aluminum foils other than the printed portion of the etching resistor (C); Washing the etching resist and the etchant with an aqueous alkali solution or the like (D); Printing in a predetermined shape using carbon paste (E); Connecting the current input terminal to the electrode layer of the aluminum foil in parallel; manufacturing method of a plane heater. The method according to claim 3, Method for producing a planar heating element, characterized in that is produced by applying an adhesive (6) or double-sided adhesive tape and a release paper (7) in order on the carbon paste.