JPH08273812A - Plain heating element - Google Patents

Abstract

PURPOSE: To uniformalize heating temperature or temperature distribution by making distribution of heating temperature controllable by arranging a high conductive region such as a strip-like high conductive body in the way as not to cross terminal electrodes in a plain heating element employing a plain resistor. CONSTITUTION: In a plain heating element composed of a plain resistor 1 and a pair of electrodes 4a, 4b connected with the plain resistor 1; at least one high conductive region 3 is so formed in the plain resistor 1 (the figure b) or on the plain resistor 1 (the figure a) as not to cross the electrodes 4a, 4b. As the resistor 1, for example, an insulating substrate 2 made of a thermally plastic resin and on which a prescribed pattern of a conductive resin composition is formed can be employed. The high conductive region 3 may be a strip-like pattern formed by sticking a conductive tape, e.g. a copper tape to the plain resistor 1 or applying a conductive paste, e.g. a silver paste to the plain resistor 1.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as a sheet heating element, there is known a sheet heating element in which a heating resistance wire is drawn along the outer shape of an object to be heated and is fused to an aluminum foil. Here, the aluminum foil is used as a heat diffusion medium, and the heat generated by the heating resistance wire heats the object to be heated through the aluminum foil. According to such a sheet heating element, even when the heated object has a complicated three-dimensional curved surface shape such as a heating toilet seat sheet, a sheet heating element having a curved surface conforming to the outer shape is obtained. Obtainable.

However, in such a sheet heating element, since the step of drawing the heating resistance wire in the manufacturing process is manual, the manufacturing process is very troublesome and automation of the manufacturing line is hindered. was there.

On the other hand, on a planar heating element consisting of a planar resistor obtained by patterning a metal foil such as stainless steel into a predetermined shape by etching, or on an insulating substrate such as a stretched / crystallized polyester film or polyimide film. There is known a sheet heating element in which a comb-shaped pattern made of silver paste is formed as an electrode and a pattern made of carbon paste is formed as a sheet resistor between the electrodes.

[0005]

However, among the above-mentioned conventional sheet heating elements, sheet heating elements using sheet resistors made by etching of metal foil and sheet resistors made by patterning carbon paste have been proposed. The planar heating element used cannot control the distribution of the calorific value. Therefore, when the planar heating element is formed in a curved surface, there is a problem that the entire area of the planar heating element cannot be heated to a uniform temperature. This is because when the planar heating element is formed on a curved surface, a large amount of current flows in the region that is the shortest distance between the electrodes, and the amount of heat generated in that region increases. In addition, when the planar heating element has a wide region and a narrow region, there is a problem that the heating temperature in the wide region is lower than that in the narrow region. This is because the resistance in the wide region is lower than that in the narrow region.

Further, in the heating toilet seat sheet, the heat generation temperature of the sheet heating element is distributed so that the temperature of the portion directly in contact with the skin becomes higher when a person sits down than the uniform temperature in the entire area. Although it is desirable to have such a desired temperature distribution, it has not been possible to achieve such a desired temperature distribution with a conventional planar heating element.

The present invention is intended to solve the problems of the prior art as described above, and in a sheet heating element using a sheet resistor, it is possible to control the distribution of the heating temperature and to reduce the heating temperature. The purpose is to make it uniform or to make the heat generation temperature have a desired distribution.

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have proposed a sheet heating element using a sheet resistor by arranging a good conductor region such as a strip good conductor so as not to intersect the terminal electrodes. The inventors have found that the current distribution of the sheet resistance can be controlled, and thereby the distribution of the heat generation temperature of the sheet resistor can be controlled, and have completed the present invention.

That is, according to the present invention, in a sheet heating element comprising a sheet resistor and a pair of electrodes connected to the sheet resistor, at least one good conductor region in the sheet resistor or on the sheet resistor. Is provided so as not to intersect the electrodes.

Hereinafter, the present invention will be described in detail.

In the present invention, the planar resistor does not include a linear resistor such as a heating resistor wire, but includes various heating resistors as long as they are formed in a planar shape. Therefore, a metal foil such as stainless steel patterned into a predetermined shape by etching or the like, a stretched / crystallized polyester film, a polyimide film, or other insulating base material is coated with carbon particles, metal particles, or metal coated with insulating particles. What is formed by coating or printing a conductive resin composition in which coated particles and the like are dispersed in an insulating resin in a predetermined pattern, carbon particles, metal particles, insulating particles on an insulating base material made of a thermoplastic resin. Is formed into a predetermined pattern of a conductive resin composition in which metal-coated particles obtained by metal-coating are dispersed in an insulating resin, and then, depending on the shape of the object to be heated, an insulating base material and a conductive resin. A sheet obtained by heat-molding a laminate with a pattern made of the composition can be used as the sheet resistor.

There is no particular limitation on the pair of electrodes connected to the sheet resistor. It may be formed by adhering a conductive tape such as a metal foil to the sheet resistor, or may be formed by applying a conductive composition in a predetermined pattern.

In the present invention, the good conductor region is a region made of a conductive material having a higher conductivity than that of the sheet resistor and provided in the sheet resistor or on the sheet resistor. For example,
As shown in FIG. 5A, when the sheet resistor 1 is made of carbon paste applied on the insulating base material 2, the good conductor region 3 is bonded to the sheet resistor 1. A strip-shaped pattern can be formed by applying a conductive tape such as a copper tape or a conductive resin composition such as a silver paste. Further, as shown in FIG. 3B, the good conductor region 3 can be formed so as to be embedded in the planar resistor 1. In this case also, the good conductor region 3 is formed of a conductive tape such as a copper tape or a conductive tape. It can be formed from a conductive resin composition such as silver paste.

The good conductor region is located between the pair of electrodes connected to the sheet resistor and has a function of controlling the current distribution between the electrodes. The shape, number and arrangement of the good conductor regions are not particularly limited as long as the good conductor regions do not intersect with the electrodes of the sheet resistor, and are appropriately determined according to the shape of the sheet resistor and the desired temperature distribution. You can When the good conductor region intersects with the electrode of the planar resistor, the intersected good conductor region functions as the electrode itself, not the good conductor region of the present invention that is between the electrodes and controls the current distribution of the planar resistor. It will be.

As a mode of forming such a good conductor region, for example, when the planar resistor has a substantially rectangular shape and a pair of electrodes are provided on two opposite sides of the planar resistor, the planar resistor is formed. In order to make the distribution of the heat generation temperature of 1 uniform, a plurality of strip-shaped good conductor regions are provided in parallel with each other so as to divide the pair of electrodes of the planar resistor substantially equally, and the length of the strip-shaped good conductor region a It is preferable that the ratio b / a of the mutual distance b between the strip-shaped good conductor regions to 1 is 1 or less. Further, in this case, it is preferable that the plurality of band-shaped good conductor regions are provided so as to be substantially parallel to the electrodes of the planar resistor. The distribution of the heat generation temperature of the conventional resistor having such a rectangular planar resistor having no good conductor region is such that the central part has a high temperature and the peripheral part has a low temperature. By forming the above, it is possible to greatly narrow the low temperature region of the peripheral portion, and to make the temperature of almost the entire area of the sheet resistor equal to the high temperature region of the central portion. When the good conductor region is formed in this way, the effect of the present invention can be obtained even if the ratio b / a of the distance b between the good strip conductor regions to the length a of the good strip conductor region exceeds 1. By setting it to 1 or less, it becomes possible to make the heat generation temperature largely uniform.

When the heat generation temperature is made uniform,
Watt density of sheet resistor (electric energy per unit area: W /
The good conductor region may be arranged so that (cm ² ) becomes uniform. By arranging the good conductor region in this way, the heat generation temperature of the planar resistor can be made uniform even if the planar resistor has a complicated shape. In this case, the method of calculating the watt density is, for example, measuring the dimension of the sheet-like resistor divided by the good conductor region to obtain the area S of that portion, while measuring the resistance R of the sheet-like resistor at that portion and the The watt density can be determined by measuring the voltage V applied to the device, determining the power consumption W of that portion by W = V ² / R, and dividing this W by the area S.

On the other hand, when the temperature of a desired region is set to be higher or lower than that of other regions, rather than making the distribution of the heat generation temperature from the planar resistor uniform, the intervals between the plurality of good conductor regions are set. May be narrowed in a region where the heat generation amount of the sheet resistor is increased and widened in a region where the heat generation amount of the sheet resistor is reduced.

The sheet heating element of the present invention can take various forms as long as the good conductor region is formed in the sheet resistor or on the sheet resistor as described above. For example, if necessary, an insulating material may be further laminated on the planar resistor having the good conductor region laminated thereon so that the planar resistor and the good conductor region are protected.

The sheet heating element of the present invention can be used for various purposes. For example, it can be used for heating toilet seats, washbasins, floor heating, electric blankets, kotatsu, car door mirrors and rearview mirrors, and snow removal. It can be used for roofs, etc.

[0020]

In the sheet heating element of the present invention, the sheet resistor is used as the heating resistor, so that the heating resistor can be produced more easily than when the heating resistor wire is drawn around and fused to the aluminum foil. It becomes possible to automate the production line. Furthermore, in the sheet heating element of the present invention, since at least one good conductor region is formed in or on the sheet resistor so as not to intersect the electrodes, the current distribution of the sheet resistor is thereby improved. Can be controlled. Therefore, it becomes possible to control the distribution of the heat generation temperature of the planar heating element, make the heating temperature uniform over the entire area of the planar heating element, and control the desired area to a high temperature or a low temperature.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. In each drawing, the same reference numerals represent the same or equivalent elements.

Example 1 A carbon paste (manufactured by Fujikura Kasei Co., Ltd., XC-) was applied to a PET film (manufactured by Teijin Ltd., Tetron film) having a thickness of 188 μm.
155 K) was printed by a screen printer so that the dry thickness was 10 μm, and dried. As shown in FIG. 1 (a), this was cut out in a ring shape having an outer diameter of 16.6 cm and an inner diameter of 7.6 cm to produce a planar resistor 1.

A width 10 is applied to the upper and lower ends of the sheet resistor 1.
Electrodes 4a and 4b were formed by pressing a copper tape (width 10 mm) with a conductive adhesive, in which carbon powder was dispersed in an adhesive, onto the mm portion with a rubber roll. The resistance between the electrodes 4a and 4b was 870Ω. Between electrodes 4a,
When AC60V was applied to 4b, the inner periphery of the ring-shaped planar resistor 1 concentratedly generated heat as shown in FIG. The curves in the figure represent the isotherms,
The numbers represent the temperature in the region sandwiched by the isotherms.

Next, a copper tape with a conductive adhesive similar to the copper tape with a conductive adhesive used to form the electrodes 4a, 4b, having a width of 3 mm, is 2 cm between the electrodes 4a, 4b. The belt-shaped good conductor region 3 was formed by pressure bonding at intervals, and thus the planar heating element 10 of the example was produced.

When AC60V was applied to the sheet-like heat generating element between the electrodes 4a and 4b in the same manner as above, as shown in FIG.
As shown in (c), the high-temperature heat generation region greatly spreads from the inner peripheral region to the outer peripheral region.

Example 2 In the same manner as in Example 1, a carbon film (XC-155K, manufactured by Fujikura Kasei Co., Ltd.) was dried to a thickness of 10 μm on a PET film (manufactured by Teijin Ltd., Tetron film) having a thickness of 188 μm. Printed and dried. The sheet resistance 1 was produced by cutting this out into a rectangle of 5 cm × 17 cm as shown in FIG.

Electrodes 4a and 4b are formed by pressing a copper tape (width 10 mm) with a conductive adhesive, in which carbon powder is dispersed in an adhesive, on the opposite short sides of the sheet resistor 1 with a rubber roll. did. AC50 between electrodes 4a, 4b
When V is applied, the temperature of the central portion of the sheet resistor 1 is 39 ° C., while that of the peripheral portion is 33 ° C., as shown in FIG.
There was a large temperature difference between the central part and the peripheral part.

Next, as shown in (c), (d), and (e) of the same figure, the same copper tape with conductive adhesive as that used for forming the electrodes 4a, 4b is coated with conductive adhesive. Use a copper tape with a width of 3 mm and divide it between the electrodes 4a, 4b into two equal parts.
1 or 2 or 9 to divide equally or 10 respectively
The band-shaped good conductor region 3 was formed by performing the main pressure bonding, and the planar heating elements 11a, 11b, and 11c were produced. In these sheet heating elements 11a, 11b, 11c, the ratio b / a of the distance b between the strip-shaped good conductor regions 3 to the length a of the strip-shaped good conductor regions 3 made of copper tape is
The values were 1.47, 0.96 and 0.37, respectively.

These sheet heating elements 11a, 11b, 11c
When AC 50V is applied between the electrodes 4a and 4b of the electrode, as shown in FIGS. 7C, 7D and 7E, the heat generating region having a higher temperature is formed in the central portion as the number of the good strip conductor regions 3 is increased. From the above to the peripheral part, it spreads greatly, and the ratio of the low temperature region of 35 ° C. or less, which fills the entire area of the planar heating element, is significantly reduced. As a result, in such a rectangular planar heating element, the heat generation temperature is set by setting the ratio b / a of the distance b between the strip-shaped good conductor regions 3 to the length a of the strip-shaped good conductor regions 3 to 1 or less. It can be seen that it can be made largely uniform.

Example 3 As in Example 1, a PET film (Tetron film, manufactured by Teijin Ltd.) having a thickness of 188 μm and carbon paste (XC-155K, manufactured by Fujikura Kasei Co., Ltd.) were dried by a screen printing machine to a thickness of 10 μm. Printed and dried. As shown in FIG. 3 (a), this is a bottom 5 cm, a top 7.5, and a height 2
A planar resistor 1 was produced by cutting out a 0 cm trapezoid.

Electrodes 4a and 4b were formed on the bottom side and the top side of the sheet resistor 1 by pressing a copper tape (width 10 mm) with a conductive adhesive in which carbon powder was dispersed in an adhesive with a rubber roll. . The resistance between the electrodes 4a and 4b was 1185Ω. AC60V between the electrodes 4a, 4b
When the voltage was applied, heat was intensively generated near the bottom side of the sheet-shaped resistor 1 as shown in FIG.

Next, as shown in FIG. 3C, the distance between the electrodes 4a,
A large number (20 pieces) of a copper tape with a conductive adhesive similar to the copper tape with a conductive adhesive used for forming 4b, having a width of 3 mm, is pressure-bonded with a rubber roll in parallel with the electrode 4a, A band-shaped good conductor region 3 made of a copper tape was formed on 4b to fabricate a planar heating element 12. In this case, the interval between the strip-shaped good conductor regions 3 was adjusted so that the watt density ratio of the block of the sheet-shaped resistor 1 divided by the strip-shaped good conductor regions 3 was 3 or less.

When AC60V was applied between the electrodes 4a and 4b of the sheet heating element 12, a heating area having a high temperature spreads over the entire area of the sheet heating element 12 as shown in FIG. .

As a result, by arranging the strip-shaped good conductor regions 3 so that the ratio of the watt density of the block of the sheet-shaped resistor 1 divided by the strip-shaped good conductor regions 3 is 3 or less, the heat generated locally is concentrated. It can be seen that the regions can be dispersed throughout and the heat generation temperature can be made largely uniform.

Example 4 In the same manner as in Example 1, a 188 μm-thick PET film (Tetorin film, Teijin Ltd.) and carbon paste (Fujikura Kasei Co., Ltd., XC-155K) were dried by a screen printing machine to a thickness of 10 μm. Printed and dried. As shown in FIG. 4 (a), this was cut into a rectangle of 5 cm × 17 cm to fabricate a planar resistor 1.

Electrodes 4a and 4b are formed by pressing a copper tape (width 10 mm) with a conductive adhesive, in which carbon powder is dispersed in an adhesive, on the opposite short sides of the sheet resistor 1 with a rubber roll. did. AC40 between electrodes 4a, 4b
When V was applied, similar to FIG. 2B of Example 2 described above, a temperature distribution was formed in which the central portion of the planar resistor 1 was high (45 ° C.) and the peripheral portion was low (39 ° C.).

Next, as shown in FIG.
A copper tape with a conductive adhesive similar to the copper tape with a conductive adhesive used for forming a and 4b and having a width of 3 mm was arranged so as to form different angles with respect to the electrodes. Then, the band-shaped good conductor region 3 was formed by pressure bonding, and thus the planar heating element 13 was produced.

When AC 40 V is applied between the electrodes 4a and 4b of the sheet heating element 13, as shown in FIG. 8B, the heating temperature at the narrow interval of the band-shaped good conductor regions 3 made of copper tape is changed. Could be higher. This allows
It can be seen that the desired temperature distribution can be imparted to the planar heating element by adjusting the interval between the good conductor regions 3.

[0039]

According to the present invention, in a sheet heating element using a sheet resistor, it is possible to control the heating temperature distribution to make the heating temperature uniform or to give a desired heating temperature distribution. Is possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a heat generation state of a planar heating element.

FIG. 2 is an explanatory diagram of a heat generation state of a planar heating element.

FIG. 3 is an explanatory diagram of a heat generation state of a planar heating element.

FIG. 4 is an explanatory diagram of a heat generation state of a planar heating element.

FIG. 5 is a cross-sectional view of a planar heating element.

[Explanation of symbols]

1 Sheet Resistor 2 Insulating Substrate 3 Good Conductor Region 4a, 4b Electrode 10, 11a, 11b, 11c, 12, 13 Sheet Heater

Claims (6)

[Claims] 1. In a sheet heating element comprising a sheet resistor and a pair of electrodes connected to the sheet resistor, at least one good conductor region intersects with the electrode in the sheet resistor or on the sheet resistor. A planar heating element characterized by being formed so as not to exist. 2. The sheet heating element according to claim 1, wherein the sheet resistor is made of a conductive resin composition formed on an insulating base material. 3. The sheet heating element according to claim 1, wherein the good conductor region is made of a conductive tape adhered onto the sheet resistor or a conductive paste applied onto the sheet low antibody. 4. A pair of electrodes are provided on two opposite sides of the sheet resistor, and a plurality of strip-shaped good conductor regions are formed in parallel with each other so as to divide the electrodes substantially equally. The planar heating element according to any one of claims 1 to 3, wherein the ratio b / a of the mutual distance b between the strip-shaped good conductor regions to the length a is 1 or less. 5. The sheet heating element according to claim 1, wherein the good conductor region is formed so that the watt density of the sheet resistor is made uniform. 6. A plurality of good conductor regions are formed, and an interval between them is narrow in a region where the heat generation amount of the planar resistor is large,
The sheet heating element according to any one of claims 1 to 3, which is widely formed in a region where the heating value of the sheet resistor is reduced.