JP2000164328A - Flat heater and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater having excellent conductivity by etching an aluminum thin film provided on an insulator so as to form parallel electrodes, and printing the etching part with the carbon paste. SOLUTION: This flat heater is formed of a pair of strip aluminum electrodes 3 formed opposite to each other on an insulator and having continuous parallel patterns projected from the electrodes so as to be engaged with each other, a power source terminal formed close and opposite to the end of the electrodes 3, and a resistor formed by printing the carbon paste 4 on the electrode 3 of the aluminum thin film. Etching resist is coated on the aluminum thin film on the insulator, and dried, and acid such as hydrochloric acid is sprayed so as to corrode and peel the aluminum, and an electrode pattern 3 is thereby obtained. The carbon paste 4 is printed on the electrode pattern 3, and dried. Carbon having 37.7×10-3 deg.cm.Sec or more of heat conductivity is desirably used for the carbon paste 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sheet heating element. More specifically, the shape of a predetermined pattern is protected on an insulator having an aluminum thin film by using an etching resistor, and a portion which is not protected by the etching resistor is etched by using an etching agent and then etched.・ A planar heating element configured so that an insulator having an aluminum thin film functions as a parallel electrode and is connected by removing a register and an etching agent and printing the same in a predetermined shape using a carbon paste. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a sheet heating element utilizing the above-mentioned technology, US Pat. No. 3,887,788, US Pat. No. 3,790,748, US Pat.
No. 781,526, No. 3,757,087, No. 5,446,576, No. 4,410,7
No. 90, No. 4,942,286, No. 5,015,824, No. 4,017,715
No. 4,304,987, No. 4,330,703, No. 2,559,077,
No. 2,978,665, No. 3,243,753, No. 3,351,882, No. 3,4
No. 12,358, No. 4,034,207, No. 4,777,351, No. 4,761,54
No. 1, No. 4,857,711, No. 4,628,187, No. 5,440,425,
Nos. 5,155,334, 3,900,654 and 3,848,144.

Japanese Patent Application Laid-Open No. 2-162143 and Japanese Patent Application Laid-open No. H08-162143 disclose similar Japanese Patents and Publications.
-64352, Hei 6-176857, Hei 7-99083, Hei 3-26
No. 1090, No. 55-95203, Published Utility Model Publication No. 61-8
No. 4063, No. 59-40417, No. 3-67904, etc. Among the above-mentioned technologies, those without a PTC resistor are those which generate heat by passing a current through a direct current, and most of them are patented. The right has been extinguished, and the resistance of the resistor is low and the ampere is high.

Further, applying a current directly to the heating element without a separate electrode has the disadvantage that the electrical conductivity is non-uniform.

In the case of an electrode and a resistor, a metal powder such as silver is mixed in a resin as an electrode and printed, and a carbon is mixed in a resin as a resistor. This is printed, and current is applied to the electrodes to generate heat in the resistor.

[0006] In such a planar heating element, in order to uniformly transmit heat, the electrode is formed in a comb-like pattern or a resistor formed in a strip shape is used as a heat transfer element. In order to improve the heat efficiency, after printing with silver paste on a pattern with a predetermined band-shaped space on the insulating substrate, apply carbon paste on the upper surface with a printer, and when printing silver paste, It can be classified into a sheet-like material or the like that covers the portion left as a space and the upper part of the silver paste.

[0007]

However, in the above-mentioned inventions and the like, silver itself has good conductivity as a conductor, but the conductivity is weak because a paste in which this is mixed with a synthetic resin in a powder state is used. And the manufacturing process is complicated, and it can be costly,
Development of a new sheet heating element different from these has been desired.

[0008]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, a film obtained by depositing aluminum on an insulator having an aluminum thin film, more preferably a PET sheet. After the shape of the predetermined pattern is protected by using an etching resistor on the upper portion, and a portion not protected by the etching resistor is etched by using an etching agent, the etching resistor and the etching agent are removed, and carbon Manufacturing a planar heating element configured such that an insulator having an aluminum thin film acts as a parallel electrode and a carbon paste layer acts as a resistor by printing the etched portion using a paste. To solve the problems described above, and completed the present invention. It led to Rukoto.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 or FIG. 2 shows a sheet heating element (1) of the present invention.
FIG.

As shown in FIG. 1 or FIG. 2, a sheet heating element (1) of the present invention comprises a strip-shaped aluminum thin film pattern (3), a carbon paste (4), and an insulating substrate (2). Current terminal (5)
(5 ').

Hereinafter, the sheet heating element (1) of the present invention will be described in detail together with a method of manufacturing the same.

First, an insulator having an aluminum thin film on which PET is laminated, that is, an insulator having an aluminum thin film formed by vacuum-depositing aluminum on PET is cut into a predetermined size or manufactured as it is. Cut from

On the insulator having the aluminum thin film, an etching resistor such as X-ray of Daiyo Inc.
After printing on a fixed pattern with a heat etching register or UV etching register such as 77, X-65, AS-500, etc., it is heated or dried by UV.

Thereafter, when an acid, for example, hydrochloric acid is sprayed onto the insulator having the aluminum thin film by a nozzle, the aluminum except for the portion protected by the etching resistor is corroded and peeled off. This is washed with water. Then
The electrode (aluminum) pattern as shown in FIG. 3 or FIG. 4 is obtained by neutralizing with an aqueous alkali solution, for example, a 1 to 3% aqueous sodium hydroxide solution to remove the etching resistor, washing with water and drying. Only are left.

A PTC carbon paste is printed on the pattern and dried to produce a sheet heating element. The sheet heating element thus manufactured has a shape as shown in FIG. 1 or FIG. 2 and a cross section as shown in FIG.

However, the pattern of the sheet heating element of the present invention can be modified for convenience of manufacture, and is not limited to the patterns shown in FIGS.

The PTC carbon paste will be briefly described, but the carbon used in the carbon paste of the present invention is not particularly limited as long as it has heat conductivity. That is, since amorphous carbon has poor heat conductivity, it is desirable to use commercially available carbon having good heat conductivity.
The thermal conductivity of these carbons is 37.7 × 10 ^-3 deg. cm. Sec or higher, and commercially available products include Nippon Carbon Co., Ltd. powdered CSP, CP, P5 (all of which are trade names), Nippon Tokai Carbon Co., Ltd., and TOKABLACK (trade name).

Each of these carbons has a different heat conductivity, and it is possible to appropriately determine the amount of the carbon used to control the heat conductivity. 50 parts by weight is desirable.

The resin used in the carbon paste is not particularly limited as long as it has a low thermal deformation property, is easily blended with carbon and has an adhesive property, and is hardly soluble in water. Examples thereof include polyester, polyacrylate, and polyamide,
Of these, polyester resins are particularly desirable.

Further, in the sheet heating element according to the present invention, a pair of band-shaped main electrodes are formed opposite to each other on an aluminum thin film of an insulating sheet having an aluminum thin film, and electrodes of a parallel continuous pattern are engaged with each other from these electrodes. An aluminum thin film formed by protecting using an etching resistor and etching the unetched portion using an etching agent to remove the etching resistor and the etching agent so as to form a protrusion. And a power supply terminal formed at an end portion of the electrode so as to be close to and opposed to each other;
This is a planar heating element composed of a resistor formed by printing a carbon paste on the aluminum thin film electrode.

The structure of the sheet heating element thus manufactured can be used as it is, but an adhesive is applied to the upper part of the sheet heating element according to a known method for convenience in distribution and use of the user. After forming the adhesive layer (6), a release paper (7) is attached.

Also, terminals (5) and (5 ') are attached to predetermined portions of the aluminum electrode (3) on the opposite side through an insulating layer. At this time, the portion of the aluminum electrode (3) is divided by the carbon paste (4) as shown in FIG. 1 or FIG.
The current input terminals (5) and (5 ') are attached to the divided aluminum (3) so that currents are connected in parallel.

Further, when the sheet heating element is large, two pairs of current input terminals may be separately mounted at the longest distance of each electrode.

Hereinafter, the present invention will be described specifically with reference to Examples and Test Examples, but the present invention is not limited to these. Example 1 A sheet (aluminum thickness: 3.0 nm, sheet thickness: 150 μm) obtained by vapor-depositing aluminum on a commercially available PET film using an etching register of X-77 (trade name) of Daiyo Inc. of Korea. Then, after printing on a pattern as shown in FIG. 2, it was dried by heating at 60 ° C. for 20 minutes.

Then, when spraying with a 5% hydrochloric acid aqueous solution,
Except for the part protected by the etching resistor, it is corroded and peeled off. This was washed with water and again with a 2% aqueous sodium hydroxide solution.

Toka Black (trade name) of Nippon Tokai Carbon Co., Ltd. was dissolved in a solution obtained by dissolving a polyester resin in a solvent of butyl cellosolve acetate at a ratio of 1.4: 1 to 6: 5.
(Weight ratio) to produce a carbon paste, which was placed on the aluminum sheet obtained by the above method at 10 μm.
Print and apply in thickness. By printing in this manner, the strip-shaped carbon paste layer (4) and the aluminum electrode (3) shown in FIG. 1 are formed.

After applying the carbon paste layer (4), a double-sided tape and an adhesive layer are formed thereon.
In this case, it is desirable to apply hot melt ethylene vinyl acetate in terms of industrial production and cost reduction.

Next, the sheet heating element of the present invention is manufactured by adhering release paper and attaching the current terminal so as to touch the aluminum electrode portion as shown in FIG.

The sheet heating element thus manufactured is freezing,
Since ice and steam can be removed very efficiently in a short time, it is useful for a side mirror of a car, a mirror of a bathroom, and the like.

Test Example 1 The following items were tested using the sheet heating element manufactured in Example 1, and the results are shown together.

1. Electrical characteristics (1) Rated voltage: 13.5V DC (2) Working voltage: 10-15V DC (3) Maximum current: AT, -40 ° C, 13.5V DC Initial current: 3.5 AMP or less 10 minutes later : 2.2 AMP or less (4) Insulation resistance: 10M or more (500V MEGA) (5) Overcurrent: No damage or burning even when DC15V is applied for 24 hours.

2. Characteristics of Ice Removal by Planar Heating Element of the Present Invention The mirror surface was wiped with ammonia water to remove oil and the like, and then wiped again with distilled water and dried. This was left at -18 ° C for 2 hours. Then at -40 ° C for 1 hour at 25 ° C 65
0.5 mm ice was uniformly formed on the mirror surface at an air temperature of ± 10%, left at -40 ° C for 4 hours, and then left at each of the following temperatures for 30 minutes, and then 13.5 V DC was applied. The results are as follows.

When energized at -5 ° C. for 3.5 minutes, 80% of the ice was removed.

When energized at -25 ° C. for 6 minutes, 80% of the ice was removed.

When energized at -25 ° C for 10 minutes, 95% of the ice was removed.

When energized at -40 ° C for 12 minutes, 80% of the ice was removed.

3. Mirror surface temperature control test When 13.5 V DC was applied at -30 ° C, the surface temperature of the mirror became 10 ° C or more after 10 minutes.

When 13.5 V DC was applied at 25 ° C., the surface temperature of the mirror became 55 ° C. ± 10 ° C. after 10 minutes.

When 13.5 V DC was applied at 45 ° C., the surface temperature of the mirror became 70 ° C. or less after 10 minutes.

4. A temperature exposure test was performed by attaching the sheet heating element of the present invention manufactured in Example 1 to a crow.
As a result, there was no distinction between −30 ° C. and 20 ° C., and there was no distinction at 115 ° C. even after applying electricity for 1 hour. 5. Apply the same object as above to DC15V in air at 10
After turning off the power supply for 5 minutes, the sample was put into a 5% NaCl solution for 5 minutes, and this was made one cycle, and this was made 200 cycles.
Further, when a 5% CaCl ₂ solution was used in the same manner as described above, there was no distinction in the sheet heating element of the present invention. 6. The surface heating temperature, low-temperature operating current, and normal-temperature operating current were tested using the sheet heating element of the present invention, and the results are shown in Tables 1 to 3 below. (In the table, LH indicates the left side mirror and RH indicates the right side mirror. J-95 is a small car selected from three Korean automakers. H-car is Korean automobile. G-car is a medium-sized car that is a product of one of the three automakers, and G-car is a medium-sized car that is a product of one of the three automakers.

[0042]

[Table 1] Surface temperature rise (at 26 ° C) (unit: 12.8V)

[0043]

[Table 2] Low temperature operating current (-30 ° C) (unit: A)

[0044]

[Table 3] Room temperature operating current (at 26 ° C) (unit: A)

Test Example 2 A large sheet heating element (a product of Europe N; hereinafter, referred to as “test piece 1”) in which aluminum was connected in series (without using a separate resistance heating element) was disclosed in US Pat. No. 4,857,711. A sheet heating element (hereinafter, referred to as a “test piece 2”) in which a silver powder paste was formed on an electrode according to the description of the item and the carbon powder paste was used as a resistor, and a sheet heating element of the present invention (hereinafter, referred to as a “test piece 2”). Each of the test pieces 3 ′) was tested under the following conditions, and the results are shown in FIG. 6 to FIG.

1) First, after the test piece 1 was cooled at -30 ° C., it was supplied with a current of 24 V, and the change of the initial current [A] and the change of the temperature every two minutes were measured. Is shown in FIG. As shown in this drawing, the initial current [A] is 2.
Although it was 25 A, it was 1.94 A after 11 minutes, and showed almost the same current after 20 minutes.
This means that it is extremely difficult to control the temperature of the planar heating element because there is almost no change in the resistance value and the current continues to flow constantly.

When the change in temperature is examined, the initial
After 11 minutes from 28 ° C, the temperature rose to 12.9 ° C,
After a lapse of minutes, the temperature rose to about 20 ° C. This indicates that the temperature control of the sheet heating element cannot be satisfied as described above. FIG. 7 shows the results of measuring the change in the initial current [A] and the change in temperature every two minutes after the test piece 1 was maintained at 40 ° C. for 30 minutes and then supplied with a voltage of 24 V at room temperature. It is shown. As in FIG. 6, the initial current [A] is 1.
It was 68 A, but it was 1.60 A after 11 minutes, showing almost the same current after 20 minutes. This indicates that it is extremely difficult to control the temperature of the sheet heating element because there is almost no change in the resistance value and the current continues to flow constantly.

FIG. 8 shows that the test piece 1 was sprinkled with water at -30.degree. C. to form ice on the surface of the mirror, and left standing for 30 minutes. A photograph of a state where the planar ice is removed by ascending is shown in the figure.

2) After cooling the test piece 2 at −30 ° C. and maintaining it for 30 minutes, the test piece 2 was energized at a voltage of 24 V,
The change in the initial current [A] and the change in the temperature every two minutes were measured and are shown in FIG. As shown in this drawing,
The initial current [A] was 4.83A, but after 20 minutes
It became 2.87A. This means that the initial current and the
Comparing the current after 20 minutes, the current after 20 minutes is quite low, and this is because the resistance value rises and the ampere decreases, which makes temperature control easy. Represents Furthermore, the temperature change from -27 ° C
The temperature rises to 31.9 ° C. after 20 minutes, indicating that the effect is considerably excellent.

FIG. 10 shows the results of testing the test piece 2 at room temperature. Also in this case, the current after 20 minutes from the passage of the initial current of 3.2 A drops to 1.70 A and the resistance value increases. Therefore, as the temperature rises, the change in the resistance value increases, and the flow of current decreases, so that the temperature is prevented from rising rapidly.

FIG. 11 shows that the test piece 2 was sprinkled with water at -30.degree. C. to form ice on the surface of the mirror. A photograph of a state where the planar ice is removed by ascending is shown in the figure. This photograph is superior to FIG.

3) After the test piece 3 was cooled at -30 ° C. and maintained for 30 minutes, the test piece 3 was supplied with a current of 24 V,
The change in the initial current [A] and the change in the temperature every two minutes were measured and are shown in FIG. As shown in this drawing, the initial current [A] was 5.45 A, but became 2.76 A after 20 minutes. This is because, when comparing the initial current and the current after 20 minutes as compared with the test piece 1 and the test piece 2, when the temperature rises after 20 minutes, the change in the resistance value increases, and the current flow decreases. The temperature control is prevented by preventing the temperature from rising sharply. And the temperature change from -27 ℃
The temperature rises to 34.8 ° C after 20 minutes, indicating that the effect is considerably excellent.

FIG. 13 shows the results of testing the test piece 3 at room temperature. Also in this case, the current after 20 minutes from the current supply at the initial current of 3.30 A drops to 1.59 A, and the resistance value increases. Therefore, the sheet heating element of the present invention has a considerably large change in resistance when the temperature rises as compared with the conventional test pieces 1 and 2, and the temperature control can be performed by reducing the current flow. It will be easier.

FIG. 14 shows that the test piece 3 was sprinkled with water at -30.degree. C. to form ice on the surface of the mirror. FIG. 3 is a photograph showing a state in which ice is removed in a planar state due to rising. This photograph shows that it is superior to FIGS. 8 and 11.

As shown in the above Examples and Test Examples, the sheet heating element of the present invention has uniform conductivity and excellent heat generation effect as compared with the sheet heating element according to the prior art. The planar heating element can be manufactured easily and at low cost.

[0056]

The sheet heating element of the present invention is a conventional silver heater.
Since there is almost no temperature deviation compared to using paste, the manufacturing cost is greatly reduced, and the manufacturing process is further simplified, so that when attached to the interior of the side mirror of a car, freezing, steam, ice, etc. Excellent removal effect.

[Brief description of the drawings]

FIG. 1 is a plan view of a planar heating element formed by etching an insulator having a polyethylene laminated aluminum thin film of the present invention and then printing carbon paste in a predetermined shape on the upper surface thereof.

FIG. 2 is a plan view of the sheet heating element of the present invention formed in a shape different from that of FIG.

FIG. 3 is a rear view of the sheet heating element of FIG. 1;

FIG. 4 is a back view of the sheet heating element of FIG. 2;

FIG. 5 is a longitudinal sectional view of the sheet heating element of the present invention shown in FIGS. 1 and 2;

FIG. 6 is a graph showing changes in current and surface temperature of a test piece 1 at −30 ° C. in Test Example 2.

FIG. 7 is a graph showing changes in current and surface temperature of a test piece 1 at −40 ° C. in Test Example 2.

FIG. 8 is a photograph of a change in the state of removal of planar ice due to a rise in surface temperature every two minutes after the start of energization at -30 ° C. in Test Example 2;

FIG. 9 is a graph showing changes in current and surface temperature of a test piece 2 at −30 ° C. in Test Example 2.

FIG. 10 is a graph showing changes in current and surface temperature of a test piece 2 at room temperature in Test Example 2.

FIG. 11 is a photograph showing a change in the state of removal of planar ice due to a rise in surface temperature every two minutes after the start of energization at −30 ° C. in Test Example 2 in Test Example 2.

12 is a graph showing a change in current and surface temperature of a test piece 3 at −30 ° C. in Test Example 2. FIG.

FIG. 13 is a graph showing changes in current and surface temperature of a test piece 3 at room temperature in Test Example 2.

FIG. 14 is a photograph showing a change in the state of removal of planar ice due to a rise in surface temperature every two minutes after the start of energization at −30 ° C. in Test Example 2 in Test Example 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Planar heating element 2 ... Insulating substrate 3 ... Aluminum thin film pattern 4 ... Carbon paste 5, 5 '... Current terminal 6 ... Adhesive layer 7 ... Release paper

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) UA19 VV03 VV33

Claims (3)

[Claims] A pair of strip-shaped main electrodes are formed on an aluminum thin film of an insulating sheet having an aluminum thin film so as to face each other, and electrodes of a continuous continuous pattern are formed so as to protrude from these electrodes so as to mesh with each other. An electrode of an aluminum thin film formed by protecting using an etching resistor and etching the unetched portion using an etching agent to remove the etching resistor and the etching agent; A power supply terminal formed so as to be close to and opposed to each other; and a sheet heating element formed of a resistor formed by printing a carbon paste on the electrode of the aluminum thin film. 2. The sheet heating element according to claim 1, wherein an adhesive layer and a release paper layer are formed below the electrode layer and the carbon paste layer of the insulator having the aluminum thin film. 3. An insulator having an aluminum thin film has an upper surface protected by an etching resistor to protect the shape of a predetermined pattern, and an etching agent etches a portion not protected by the etching resistor. A method of manufacturing a sheet heating element, comprising removing a register and an etching agent, printing the sheet in a predetermined shape using a carbon paste, and connecting the electrode terminals to the aluminum electrode layer in parallel.