KR20000032499A - Ptc sheet heating element using aluminum sheet - Google Patents

Abstract

PURPOSE: A PTC sheet heating element using an aluminum sheet is provided which has good conductivity and stability. CONSTITUTION: A PTC sheet heating element is fabricated by forming a polymer insulating layer(5) on an aluminum foil film(1), which is made by depositing an aluminum on a PET sheet(1a), and then after forming a carbon layer(3) on the insulating layer, by forming a silver layer(4) on the carbon layer. The heating element is easy to fabricate and has few temperature deviation than using the conventional silver paste, and the fabrication cost is reduced. The heating element is used in removing frost and ice by being attached inside a side mirror of a car.

Description

PLATI RESISTANCE HEATING ELEMENT UTILIZING ALUMINUM SHEET

The present invention relates to a PTC planar heating element using an aluminum sheet. In more detail, an insulating layer is formed of an aluminum foil on which aluminum is deposited on PET with a polymer, and a carbon (PTC) layer is formed using carbon paste thereon, and then a silver layer having a predetermined pattern is formed. It relates to a PTC planar heating element using an aluminum sheet formed by connecting the terminals in parallel.

BACKGROUND ART Conventionally, heaters using electricity are known to be configured by connecting a wire to a tip of a heating wire on a rear glass of a heater or a heater connected to a nichrome wire.

The present inventors are unsuitable for use in fixed mirrors such as a side mirror of an automobile or a bathroom as a conventional heater, and in order to use them, a carbon paste having good thermal conductivity is applied in a fixed form, and then each of these floating pastes is challenged. Patent application of the sheet-shaped heater that connected the electric wires at both ends of the sieve was registered as patent No. 83589. Also, when this patent is applied, it is difficult to manufacture and improve the heat efficiency due to the use of electric wires. In order to solve this problem, in order to solve such a problem, a silver paste is printed in a pattern having a predetermined space on the insulating substrate, and carbon paste is applied thereon to print the silver paste. A patent has been filed on a sheet covering the silver paste (see : 1996-32989). In addition, the present inventor has applied for a planar heating element in which a carbon layer is formed after protecting a predetermined portion of aluminum by using a resist on an aluminum sheet, etching the remaining portion to form a pattern in a predetermined shape (see, patent) Application 98-41477). However, since the planar heating element has a high electrical conductivity, it is easy to generate a short, so there is a difficulty in adjusting the electric and heating elements, and only a person with a high level of knowledge has a disadvantage. In addition, many inventions and designs similar to these inventions have been filed or registered.

However, the above inventions have good conductivity and good safety when only silver is used as a conductor. However, since the paste is formulated in a powdered state into a synthetic resin, the conductivity is poor, or the manufacturing process is complicated, and the cost is high. In the case of using an electrode wire, there is a problem such as disconnection during transportation and installation, and development of a new planar heating element has been required.

As a result of intensive studies to solve the above problems, the inventors have formed an insulating layer with a polymer on an aluminum foil, preferably a film on which aluminum is deposited on a PET sheet (hereinafter also referred to simply as "aluminum foil"). and; After forming a carbon layer thereon; As a result of forming a silver layer to produce a heating element, it was found that the conductivity was good and stable, and thus the present invention was completed.

1 shows an aluminum deposition film for producing a PTC planar heating element using the aluminum sheet of the present invention,

FIG. 2 is a view showing a state where an insulator is printed on the aluminum sheet of FIG. 1, wherein a white portion represents an unprinted portion.

Fig. 3 shows a state diagram in which carbon is printed on the sheet of Fig. 2.

4 is a state diagram in which a silver layer is formed on the sheet of FIG. 3 using silver paste.

5 is a view illustrating a state after cutting after forming the silver layer of FIG.

6 is a surface view of a PTC planar heating element using the aluminum sheet of the present invention.

FIG. 7 is a longitudinal cross-sectional view of AA ′ of FIG. 6.

Fig. 8 shows a longitudinal cross-sectional view of an adhesive layer and a release paper layer formed on a PTC planar heating element using an aluminum sheet.

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

FIG. 1 shows an aluminum deposition film for producing a PTC planar heating element using the aluminum sheet 1 of the present invention, and FIG. 2 shows a state in which the insulating layer 2 is formed by printing with a polymer on the aluminum sheet of FIG. As shown, the white portion 1 is the portion not printed with polymer. FIG. 3 shows a state in which the resistive carbon layer 3 is formed using a carbon paste on the sheet of FIG. 2. In FIG. 3, the code | symbol 1 is the aluminum layer 1 in which the carbon layer is not formed. FIG. 4 shows that the silver layer 4 is formed on the sheet of FIG. 3 using silver paste. In Fig. 4, reference numeral 1 denotes that no carbon layer or silver layer is formed on the aluminum layer, reference numeral 3 denotes a resistor carbon layer, and reference numeral 4 denotes a silver layer. FIG. 5 is a plan view after cutting after forming the silver layer of FIG. 4, and FIG. 6 is a surface view of FIG. 4. In Fig. 6, reference numerals 8 and 8 'denote terminals, and one terminal 8 is connected to the silver layer, and the other terminal 8' is connected to the aluminum layer.

7 is a longitudinal cross-sectional view of a PTC planar heating element using the aluminum sheet of the present invention, where 1a represents a PET layer, 1 represents an aluminum layer, 5 represents a polymer insulating layer, 3 represents a carbon layer, and 4 represents a silver layer. .

8 is a longitudinal sectional view of a PTC planar heating element using the aluminum sheet of the present invention, wherein 1a is a PET layer, 1 is an aluminum layer, 5 is a polymer insulation layer, 3 is a carbon layer, 4 is a silver layer, 6 represents a release layer.

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

First, an aluminum foil in which PET is laminated, that is, an aluminum foil obtained by vacuum deposition of aluminum on PET is cut to a predetermined size or manufactured as it is, and then cut. An insulating layer is formed as a polymer on this aluminum sheet. At this time, the polymer to be used may be used without any limitation as long as it forms insulation. Specific examples include polyethylene, polyacrylate, insulating ink, and the like. As a method of forming this insulating layer, the printing method is preferable, and the white part shown in FIG. 2 shows that it is not printed. After printing the insulating layer, it is dried using a UV dryer. Then, as shown in FIG. 3, except for the portion 1, the carbon layer is formed using the carbon paste throughout. Here, PTC carbon paste is demonstrated briefly. Carbon used for the carbon paste is not particularly limited as long as 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 to control the heat resistance, and the amount thereof used is preferably 10 to 50 parts by weight based on 100 parts by weight of the resin. The resin used for the carbon paste has little heat denaturation, is easily blended with carbon, and has no special preparation as long as it is adhesive and poorly water soluble.

Examples thereof include polyesters, polyacrylates, polyamides, and the like, of which polyester resins are particularly preferred.

After forming a carbon layer as above, it prints on the sheet obtained above with silver paste, and forms a silver layer. In Fig. 4, reference numeral 1 denotes an unprinted aluminum layer, reference numeral 3 denotes a carbon layer, and reference numeral 4 denotes a silver layer. The silver powder used for the silver paste used here is pure (99% or more), and its size passes through 250 mesh. Silver powder is excellent in electrical conductivity, meets the above conditions and may be commercially available. The amount of silver used for silver paste is 50-80 weight part with respect to resin. There is no particular limitation as long as the resin is less thermally deformable, is easily blended with silver or carbon, and has adhesiveness and poorly water solubility. Examples thereof include polyesters, polyacrylates, polyamides, and the like, of which polyester resins are particularly preferred.

The PTC planar heating element using the aluminum sheet thus manufactured can be used as it is, but in order to facilitate distribution or purchaser use, the adhesive layer 6 is applied by applying an adhesive on the upper part of the heating element according to a known method. After forming, the release paper 7 is attached.

Further, terminals 8 and 8 'are provided in predetermined portions of the aluminum electrode 3 on the opposite side and in the silver layer. Such current input terminals 5 and 5 'are provided so that currents are connected in parallel.

10V to 15V may be used as the voltage input to the current input terminals 8 and 8 '. When 100V or 220V of power is input, the aluminum and silver components burn out, and thus the planar heating element of the present invention cannot be used. Therefore, the planar heating element of the present invention can be used only in the rearview mirror of an automobile or an article supplied with a voltage of 10V to 15V.

If the product is to be supplied with a high voltage of 100V or 220V, the transformer must be installed to reduce the voltage to the above range. Hereinafter, the present invention will be described in detail by way of examples.

Example 1

A PET film was printed on a commercially available PET film (aluminum thickness: 3.0 nm, sheet thickness: 150 μm) using PET in a pattern as shown in FIG. 2, and then dried using a UV dryer. . Here, white represents an unprinted part. Then, the carbon paste was printed to a thickness of 10 탆 over the entirety except for 1 part. The carbon paste used here is a paste obtained 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 in a ratio of 1.4: 1. .

The sheet obtained above was printed with a thickness of 10 mu m in the pattern shown in Fig. 4 using silver paste. The silver paste used herein was dissolved in a polyester resin in a solvent of butyl cellulsolve acetate in a ratio of 1.4: 1, and then the polyester solution was dissolved in pure silver (99.5%) powder of 250 mesh through 7: 3 (weight ratio). Was used. Then, as shown in FIG. 5, the sheet was cut into a predetermined shape, and one of the current terminals was connected to the aluminum layer and the other to the silver layer to prepare a PTC planar heating element using the aluminum sheet of the present invention.

A double-sided tape or adhesive layer is formed on the PTC planar heating element using the aluminum sheet prepared above. In view of industrial production and cost reduction, it is preferable to apply hot malt ethylene vinyl acetate. Then, by releasing a release paper to produce a planar heating element of the present invention as shown in FIG.

The planar heating element manufactured in this way cannot be used at high voltages (100V and 200V) but is extremely efficient at low voltages (10V to 15V), and is useful for side mirrors and bathroom mirrors in cars because ice and fog can be removed in a short time.

Test Example

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

1. Defrosting performance

The substrate was sprayed with water, ice-cooled at −30 ° C., and then tested to remove frost through current. The test standard is to remove more than 80% after 5 minutes with 12.8V applied at -10 ℃. The test results are as follows.

Division time Invention Conventional products AMP % AMP % Early 2.25 0 2.00 0 1 minute 2.16 1.98 2 minutes 2.11 80 1.96 20 3 minutes 1.98 1.93 4 minutes 1.89 1.90 5 minutes 1.81 90 1.88 80

2. Surface temperature measurement test

The surface temperature was measured at 25 ° C using the same standard as the above test. Standards require less than 65 ° C with 12.8V applied at 22 ± 4 ° C.

Time division Early 1 minute 2 minutes 4 minutes 6 minutes 8 minutes 10 minutes Conventional 22 29.6 34.9 41.7 45.6 47.7 48.6 Invention 22 33.5 38.1 42.3 45.6 48.1 50.0

3. Low temperature operation test

Low temperature operation tests were performed at -30 ° C. At this time, the fan was started and the non-operation was tested together. The required criterion is to be below 3.5A at the beginning of 12.8V at -30 ℃ and below 2.5V after 10 minutes

1) Current test voltage for fan operation (13.5V)

Division time Invention Conventional Temperature (℃) AMP Temperature (℃) AMP Early -27.6 2.41 -28.4 2.21 30 seconds -21.4 2.35 -25.9 2.12 1 minute -17.6 2.34 -23.4 2.11 2 minutes -12.6 2.29 -19.9 2.08 5 minutes -5.1 2.24 -16.9 2.06

2) Current test voltage when fan stops (13.5V)

Division time Invention Conventional Temperature (℃) AMP Temperature (℃) AMP Early -24.4 2.42 -28.4 2.21 30 seconds 2.38 2.15 1 minute 2.33 2.12 2 minutes 2.23 2.06 5 minutes 13.3 1.98 2.5 1.93

As shown in the above examples and test examples, the planar heating element of the present invention has an excellent effect in removing frost, frost, steaming, ice at low voltage as compared to the prior art (Patent No. 83589).

Compared with the conventional silver paste, the planar heating element of the present invention has almost no temperature variation, reduces manufacturing costs, and simplifies the manufacturing process so that the inside surface of the vehicle is attached to the inside of the side mirror of the car, which is excellent in removing frost, ice, etc. Indicates.

Claims (3)

In the planar heating element consisting of an insulating substrate, a resistor carbon layer and an electrode terminal, An aluminum sheet layer obtained by depositing aluminum on polyethylene; Resistor layer made of carbon paste; A silver layer formed using a silver paste of a predetermined pattern; An electrode layer connected to the aluminum layer and the silver layer; PTC Planar Heating Element Using Aluminum Sheet The PTC planar heating element using aluminum sheet which formed the adhesive bond layer and the release paper layer on the silver layer. The PTC planar heating element using an aluminum sheet according to claim 1, wherein the insulator layer on the aluminum layer is a PET layer.