JP2554617B2 - Electrical appliances - Google Patents

Abstract

In an electrical device comprising first and second members having different resistivities, a thin contact layer of intermediate resistivity is provided between the first and second members. The contact layer, (which may comprise a conductive polymer) is intimately bonded to the member of highest resistivity (which may comprise a second conductive polymer) e.g., by a printing process. The member of lowest resistivity may comprise a third conductive polymer, in which case it may be intimately bonded to the intermediate contact layer, e.g., by a printing process, or it may comprise a metallic member, in which case good electrical contact may be made merely by pressing the metallic member against the contact layer even when the contact area is large and/or long, and even when the pressure is sufficiently low to permit, if necessary, relative movement of the metallic member and the contact layer without disrupting the bond between the contact layer and the resistive element. A preferred device comprises four or more members of different resistivities. The members are arranged adjacent each other in order of decreasing resistivity. The least resistive member preferably comprises a metal and the other members conductive polymer materials.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric appliance having conductive members having different resistivities.

[PRIOR ART AND PROBLEMS TO BE SOLVED] Many electric appliances, particularly heaters, having conductive members having different resistivities are known. Such appliances include metal members for use with resistive elements such as, for example, conductive polymers (ie, a mixture of conductive fillers and organic polymers (which term includes polysiloxane)). The filler is dispersed (or otherwise retained by the polymer) in the organic polymer. Conducting polymers show PTC behavior. Documents describing conductive polymer compositions and devices containing them include, for example:
U.S. Pat.Nos. 2,952,761, 2,978,665, 3,243,753, 3,351,8
82, 3,571,777, 3,757,086, 3,793,716, 3,823,217, 3,
858,144, 3,861,029, 3,950,604, 4,017,715, 4,072,84
8, 4,085,286, 4,117,312, 4,177,376, 4,177,446, 4,1
88,276, 4,237,441, 4,242,573, 4,246,468, 4,250,40
0, 4,252,692, 4,255,698, 4,271,350, 4,272,471, 4,3
04,987, 4,309,596, 4,309,597, 4,314,230, 4,314,23
1, 4,315,237, 4,317,027, 4,318,881, 4,327,351, 4,3
30,704, 4,334,351, 4,352,083, 4,388,607, 4,398,08
4, 4,413,301, 4,425,397, 4,426,339, 4,426,633, 4,4
27,877, 4,435,639, 4,429,216, 4,442,139, 4,459,47
3, 4,481,498, 4,476,450 and 4,502,929; Klason and Kubat, Journal of Applied Polymer Science (J.Applie
d Polymer Scienece 19 , 813-815 (1975); Narkis et al., Polymer Engineering &
Science (Polymer Engineering and Science) 18 , 64
9-653 (1978); U.S. Patent Application No. 601,424 corresponding to West German Laid-Open Publication No. 1,634,999; West German Laid-Open Publication No. 2,74.
US Patent Application No. 732,792 corresponding to 6,602; US Patent Application No. 798,154 corresponding to West German Laid-Open Publication No. 2,821,799
U.S. Patent Application No. 134,354; European Patent Application Publication No. 38,
U.S. Patent Application No. 141,984 corresponding to 718, U.S. Patent Application No. 141,988 corresponding to European Patent Application Publication No. 38,718
U.S. Patent Application No. 141,989 corresponding to European Patent Application Publication No. 38,713, U.S. Patent Application No. 141,991 corresponding to European Patent Application Publication No. 38,714, British Patent Application Publication No. 2,07.
US Patent Application No. 150,909 corresponding to 6,106A, US Patent Application No. 184,647, US Patent Application No. 250,491 corresponding to European Patent Application Publication No. 63,440, European Patent Application Publication No. 6
US Patent Applications Nos. 272,854 and 403,20 corresponding to 7,679
3, U.S. Patent Application No. 274,010, European Patent Application Publication No. 7
U.S. Patent Application No. 300,709 and U.S. Patent Application No. 423,589 corresponding to 4,281, U.S. Patent Application No. 369,309, U.S. Patent Application No. 483,633, U.S. Patent Application No. 493,445 corresponding to European Patent Application Publication No. 128,664, U.S. Patent Application No. 606,033 corresponding to European Patent Application Publication No. 119,807; U.S. Patent Application No. 50 corresponding to European Patent Application Publication No. 133,748.
9,897 and 598,048, U.S. Patent Application No. 524,482 corresponding to European Patent Application Publication No. 134,145, U.S. Patent Application No. 5
34,913, European Patent Application Publication No. 138,424 (84,306,45
6.9) corresponding to U.S. Patent Application No. 535,449 and European Patent Application Publication No. 144,187.
And U.S. Patent Application No. 904,736 corresponding to British Patent Nos. 1,470,502 and 1,470,503.

Care must be taken to ensure a satisfactory electrical contact with minimal contact resistance between two members of different resistivity. This is especially true when large and / or long contact areas are required to form a contact between a resistive element made of a conductive polymer and a metal member, such as in strip heaters and large sheet heaters. Several methods have been proposed to make such contact between the metal member and the resistive element. Some of these methods involve heating the conductive polymer while contacting the metal member to a temperature above the melting point of the conductive polymer. The molten conductive polymer is contacted with a suitably preheated metal member, and / or the metal member and conductive polymer are heated after being contacted.
It is also known to coat a metal member with a highly conductive polymer (eg, one that contains a fairly high concentration of silver or graphite) prior to contacting the metal member with the conductive polymer of the resistive element. Other methods include the use of conductive adhesives, staples or rivets.

[Means for Solving the Problems] The inventors have found that a thin contact layer made of a material having a resistivity between those of two conductive members having different resistivities is provided between the two conductive members. It has been found that improved electrical contact between the two members is obtained when sandwiched and bonded to a high resistivity member surface. The improved electrical contact provides lower contact resistance and higher voltage stability compared to appliances that do not have a contact layer.

According to the first aspect, the present invention provides: (1) A first resistance having a resistivity of 1 to 500,000 Ω · cm at 23 ° C.
A resistive element comprising a conductive material, (2) a contact layer directly coupled to the resistive element surface and comprising a second conductive material having a resistivity at 23 ° C. less than that of the first conductive material, and (3) ) An electrical appliance comprising a connecting member made of a third conductive material having a resistivity at 23 ° C. lower than that of the second conductive material, the connecting member being in direct physical contact with the contact layer. , Maintain such contact substantially only by pressure over a connection area having an area of at least 3.23 cm ² (0.5 in ² ) or at least one dimension greater than 2.54 cm (1 in), and the device is powered by An electrical appliance is provided in which the resistive element, the contact layer and the connecting member are arranged such that the electrical path is connected from the connecting member through the contact layer to the resistive element.

In such a device, good electrical contact between the resistive element and the connecting member (ie, the minimum resistivity member) provides good contact even when the connecting area is large and / or long and the pressure connects to the contact layer. This is done by simply pressing the connecting member towards the contact layer, even if it is low enough to move the member. In one preferred embodiment, the connecting member provides connecting means for connection (eg to a power source).

According to a second aspect, the present invention provides: (1) A first device having a resistivity of 1 to 500,000 Ω · cm at 23 ° C.
A resistive element comprising a conductive material, (2) a contact layer directly coupled to the resistive element surface and comprising a second conductive material having a resistivity at 23 ° C. less than that of the first conductive material, and (3) ) (A) The third electrically conductive material is (i) an electrically conductive polymer comprising an organic polymer and an electrically conductive filler dispersed in the organic polymer, and (ii) 23 ° C at a temperature higher than 1x10 ^-5 Ω · cm. An electrical device comprising a third conductive material having a resistivity at 23 ° C. lower than that of the second conductive material in (b) having a separate member in direct physical contact with the contact layer. Thus, there is provided an appliance in which the resistive element, the contact layer and the separate member are arranged such that when the appliance is connected to a power source, the electrical path extends from the separate member through the contact layer to the resistive element.

The present invention is: (1) First, having a resistivity of 1 to 500,000 Ω · cm at 23 ° C
A layered resistive element made of a conductive material and having substantially flat surfaces that are coplanar and spaced apart, (2) a first material directly bonded to each substantially flat surface, at 23 ° C. A comb-shaped contact layer made of a second conductive material having a resistivity lower than that of (3), and (3) a third conductive layer having a resistivity higher than 1 × 10 ⁵ Ω · cm at 23 ° C. but lower than that of the second material. An electrical appliance comprising a comb-shaped separate member made of a conductive material, the separate member being in direct physical contact with each contact layer, bonding to the contact layer, providing a plurality of comb-shaped electrodes, and connecting to a power supply. Also provided is an appliance that is shaped and arranged to pass an electrical current therethrough through the resistive element plane when the electrical resistance is reduced.

In the device of the present invention, it is preferred that there is no direct physical contact between the resistance element and the connecting member or another member.

The resistive element of the device of the present invention preferably comprises a conductive polymer. When the device is a heater, the conductive polymer preferably exhibits PTC behavior and the heater is self-regulating. The preferred resistivity at 23 ° C depends on the size of the power source and heater used, but is, for example, 5 to 50 Ω · cm at a voltage of up to 6 DC volts, 50 to 500 Ω · cm at 4 to 60 DC volts, 110 to 240 500 to 10,000 Ω · cm at AC volt and 10,000 to 100,000 Ω · cm at voltages higher than 240 AC volt. Generally, the conductive filler in the conductive polymer comprises carbon black, more preferably consisting essentially of carbon black.

The contact layer is also preferably made of a conductive polymer. The contact layer exhibits PTC, substantial ZTC or NTC behavior at the operating temperature of the device. The ratio of the resistivity of the resistive layer material to the resistivity of the contact layer material is preferably at least 20: 1, more preferably at least 100: 1, especially at least 1000: 1 or even higher (eg at least 100,000: 1). You can The contact layer can be formed on the resistive element by, for example, printing a conductive ink on the resistive element, or by the use of polymer thick film technology, or by methods including etching steps, or by other methods. The contact layer may be present only between the most conductive member and the resistive element or may extend beyond the connecting member, in which case it may serve as the preferential current carrier.

In the device according to the first aspect of the invention, wherein the minimum resistivity member is preferably metallic and preferably serves as the connecting means, the contact layer preferably extends beyond the minimum resistivity member. In this case, the contact layer may provide one or more electrodes that extend beyond the connecting member.

The electrode provided by the contact layer is disclosed in Japanese Patent Application Laid-Open No. 60-184836 (corresponding to US Pat.
It is preferably formed in the same manner as described in Japanese Patent Application No. 60-011740 filed on March 23. That is, (a) such that a substantial portion of the current is parallel to the surface of the resistance element when the current flows between the electrodes, and (b) the average width of the electrode measured parallel to the resistance element surface: resistance element surface. Has a dimension such that the ratio of the average distances between adjacent electrodes carrying the current measured parallel to is at least 0.01: 1, in particular 0.1: 1 and on the surface of the resistive heating element (in the present invention the maximum resistivity layer) There may be a plurality of ribbon-shaped electrodes arranged.

In all the electrodes, the distance between the adjacent electrodes where the current flowing parallel to the resistance element surface flows is not more than 3 times the average distance between the adjacent electrodes where the current flowing parallel to the resistance element surface flows. It is preferably dimensioned and arranged. The ratio of the average width of the electrodes to the average distance between the electrodes through which the current flows is preferably 0.4: 1 to 5: 1. It is particularly preferred that the electrodes comprise a plurality of parallel bars, which are preferably substantially equidistant from one another. Adjacent electrodes are preferably separated by less than 2.54 cm (1 inch). If the resistive element is a conductive polymer that is melt extruded, the electrodes are preferably adapted to allow current to flow in the extrusion direction.

In the device according to the second aspect of the present invention, wherein the separate member has a resistivity of more than 1 × 10 ⁻⁵ Ω · cm and is non-metallic, the contact layer is different from the separate member so that there is no direct contact between the separate member and the resistance element. It is preferable to have a similar shape and to extend slightly beyond another member. In this case, the separate member may provide one or more electrodes. Each of the devices of the present invention has a current path from the element with the lowest resistivity of the three elements through the other element with the intermediate resistivity to the highest resistivity of the three elements. Gives the three elements that are arranged relative to each other to be present. The device may have more than three elements of different resistivities. If more than three elements are present, the elements are preferably arranged in order of their resistivity, so that electrical contact between any two elements is dependent on the presence of an intermediate resistivity layer between them. Be improved. For example, a preferred appliance has four elements with different resistivities, with the element with the lowest resistivity of the four elements having a metal connection member for connecting to a power source. . The minimum resistivity element is in contact with the second high resistivity layer, which preferably extends beyond the contact member to provide an electrode and which has a similar shape to the second layer It contacts the third high resistivity layer, which preferably extends slightly beyond the layer. The third layer contacts the high resistivity layer which preferably provides the substrate resistance element. The device of the present invention may comprise four members of increasing resistivity.

Thus, by using one or more intermediate resistivity layers between members of different resistivity, 10 ¹⁰ Ω
Good electrical contact is obtained between members that have different resistivities in cm and even up to 10 ¹² Ω · cm.

In a preferred device of the present invention, particularly in the device of the first aspect of the present invention, the contact layer has a conductive filler of metal (preferably silver), or a mixture of silver and graphite or a mixture of silver, graphite and carbon black. Preferably, it comprises a conductive polymer consisting of or containing. In this case, the contact layer preferably has a resistivity of 2.5 × 10 ^{−5 to 1} × 10 ⁻³ Ω · cm. In another preferred device of the invention, especially in the device of the second aspect of the invention, the contact layer comprises a conductive filler of graphite and / or carbon black, or graphite and / or carbon black and a metal (eg silver). )) (Wherein graphite and / or carbon black are higher than silver). In this case, the contact layer preferably has a resistivity of 0.5 × 10 ^{−2 to} 0.1 Ω · cm.

Preferred features of the connecting member or another member in the device of the present invention will be described below. In the device according to the first aspect of the present invention, in particular, the connecting member is at least one kind of metal (for example, copper, aluminum, nickel, silver or gold which is usually preferable in terms of economy) or one metal coated with another metal ( (E.g. nickel coated copper or tin coated copper), usually in the form of a wire or sheet or tape, which may be straight, curved or folded. In general, each device may have two or more connecting members, which are connectable to a power source so that current flows through the resistive element. The connection area between each connection member and the contact layer is at least
0.5 square inches, preferably at least 5 square inches,
For example, it may be at least 10 square inches and more. The connection area should be at least 1.27 cm (0.5 inches), and preferably 2.54 cm (1 inch) in at least one dimension.
Inches) or more, or more, for example, at least 1
It is often 2.7 cm (5 inches). The connecting member preferably contacts the contact layer substantially continuously, but need not.

In the device of the present invention, the second member of the present invention, wherein the separate member has a resistivity of greater than 1x10 ^-5 Ω · cm, and thus is non-metallic
In the device of the gist of (1), it is preferable that the separate member is made of a conductive polymer. The other member exhibits PTC, substantial ZTC or NTC behavior at the operating temperature of the device. In an embodiment of the device according to the second aspect of the present invention, the resistivity of the contact layer:
The resistivity ratio of the separate member may be 5: 1 to 10,000: 1,
It is preferably 10: 1 to 1,000: 1, for example 100: 1.

The resistivity of the connecting member or another member is lower than that of the contact layer, but higher than 1x10 ^-5 Ω · cm. The resistivity of the separate member is preferably 1x10 ^{-5 to} 1x10 ^-2 Ωcm, more preferably
It is 1x10 ^{-4 to} 1x10 ^-3 Ω · cm. In a preferred embodiment,
The resistivity is about 5x10 ^-4 Ω · cm.

When the connecting member or another member comprises a conductive polymer, the member is formed by the same method of applying the contact layer to the resistive layer, i.e. by using polymer thick film technology.
It may be applied to the contact layer by printing a conductive ink on the contact layer, or by a method that includes an etching step, or by other methods.

The apparatus according to the first aspect of the present invention includes: (i) a sheet heater, for example, a sheet heater, in which the resistive element is a layered element having a substantially flat surface spaced apart at which the contact layers bond. The connecting member
A sheet heater having a substantially flat surface that is pressed against each contact layer, the contact layer extending beyond the area in contact with the connecting member to provide a plurality of electrodes; and (ii) a resistive element , A strip heater in the form of a strip having spaced apart concave surfaces to which the contact layers are bonded, the connecting member comprising a strip heater having substantially complementary convex surfaces pressed against the respective contact layers. .

The apparatus according to the second aspect of the present invention includes a sheet heater in which the separate member itself provides a plurality of electrodes, and the contact layer extends together with the electrodes, preferably slightly beyond the electrodes. The contact layer preferably has the same shape as the electrode. Each of the contact layer and the electrode is preferably in the form of a conductive ink which is applied in turn to the resistive layer by a printing method.

The device according to the second aspect of the present invention preferably also has a metal connecting member for connecting to a power source. The connecting member preferably contacts the electrode and preferably has preferable characteristics derived from the connecting member of the device according to the first aspect of the present invention.

In the device of the second aspect of the invention, the resistive element is a layered element having a substantially flat surface spaced apart to which respective contact layers are joined and further respective separate members are joined. preferable. The separate member provides a plurality of electrodes such that when connected to a power source, a current flows through the resistive element (preferably in the plane of the resistive element). The substantially planar surfaces that are spaced apart are preferably coplanar and the electrodes are preferably comb-shaped. The contact layer has the same general shape as the electrode, but preferably extends beyond the electrode. In the comb-shaped electrode, the width of the contact layer is preferably 1.5 to 3 times, for example about 2 times, the width of the electrode.

The device of the present invention preferably has a dielectric layer covering and tightly bonding at least a portion of the electrode. The device of the invention, in particular the device which is a heater, preferably also has a layered insulating polymer element adjacent to but not fixed to the electrode or (optionally) the dielectric layer or to the surface of the resistive element with electrodes. The insulating element is preferably the same as that described in Japanese Patent Application Laid-Open No. 61-74285 (the present application corresponding to US Patent Application No. 650,918 (the title of the invention: seat heater)).

In the device according to the first aspect of the present invention, the connection region between the resistance element and the connection member has an area of at least 6.45 cm ² (1
Square inch), preferably at least 32.3 cm ² (5 square inch). At least one dimension of the connection area is
It is preferably larger than 7.62 cm (3 inches).

An advantage of the device of the present invention is that it can be used in applications where a current of at least 5 amps and in some cases at least 10 amps is required to flow through the device.

Preferably, the separate member provides a plurality of electrodes (eg, comb-shaped electrodes) on the surface of the layered resistive element, each contact layer providing an intermediate resistivity layer between the electrode and the resistive element. In particular, in sheet heaters, the presence of the contact layer not only improves the electrical contact between the electrode and the resistive element, but also in the appliance, as compared to the device without the intermediate contact layer and with the electrode in direct contact with the resistive element. Significantly improves voltage stability. The voltage stability of a device shows how the resistivity of the device changes with voltage. This is the term linearity ratio (LR), or low voltage (typically 30m
Conventionally expressed as the ratio of the resistivity at V) to the resistivity at high voltage (typically 100V). Ideally, in a perfectly stable material, the linearity ratio is 1. The improved voltage stability in the device of the second aspect of the invention is that the device is subjected to abrupt current inflow or temperature aging as compared to similar devices in which the intermediate resistivity layer is not between the electrode and the resistance layer. Is especially important if

To demonstrate the improvement in the device of the second aspect of the present invention (with the intermediate resistivity layer between the electrode and the resistive element) compared to the comparative control device (without the intermediate resistivity layer), the device was voltage treated. Comparative tests were carried out after being cycled or aged. In the test, a comparative control (no intermediate resistivity layer) device was formed by printing one comb electrode layer on a conductive polymer resistive element, which was a vinyl based material containing silver, graphite and carbon black. It contained conductive ink. The device of the present invention (with an intermediate resistivity layer) is formed by printing a comb-like contact layer on a similar resistive element and printing a comb-like electrode on each contact layer, the contact layer comprising graphite and carbon black. It comprised a vinyl-based conductive ink containing and had a resistivity between that of the electrode and the resistive element. In the control device, the comb-shaped electrode has a width of 0.16 cm
(1/16 inch), separated by 0.64 cm (1/4 inch). In the device of the invention, the electrodes are 0.16 cm wide (1 /
16 inches), the contact layers were 0.32 cm (1/8 inch) wide, and adjacent contact layers were spaced 0.64 cm (1/4 inch) apart.

Three sets of test and control devices were manufactured.
The first set of instruments did nothing. The second set of equipment is 24
The current was subjected to a voltage input cycle in which the current was pulsed on and off at 0 V at 15 minute intervals. The pulses were performed at 21 ° C (70 ° F) for 250 cycles. The cycle provided a tool treatment that was switched on and off continuously, thus subjecting it to a so-called "rush current" current each time it was switched on.
The third set of appliances is continuously powered at 240V and 107 ° C.
Aged at (225 ° F) for 1 week. The resistivity of each set of instruments is 30 mV and 100 at 21 ° C (70 ° F)
V was measured and the linearity ratio of each was calculated. The results are shown in Table 1.

The linearity ratio of control samples increases significantly and undesirably with cycling and aging. On the other hand, the linearity ratio of the test sample increased only slightly.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show a heater comprising a comb-shaped electrode 12 and a heating element having an electrode 13 with a layered conductive polymer resistive element 11 printed on its upper surface. The comb electrodes 12 and 13 are composed of a conductive polymer composition containing a metal (eg, silver) as a conductive filler and have a substantially lower resistivity than the conductive polymer in element 11. Busbars 15 and 16 consist of a stretched metal mesh and electrode 12
And 13 and element 11 are folded around the respective end portions of the electrodes, the end portions of the electrodes providing the contact layer of the present invention. Insulation jackets around the heating elements and busbars, lower polymer sheet 17 and upper polymer sheet 18
Is formed by. The lower sheet 17 is formed by a substantially continuous adhesive layer 21 or melt bonding (not shown).
It is fixed to the lower part of the resistance element, the lower part of the bus bar and the end part of the upper sheet. The upper sheet 18 is adjacent to but not fixed to the busbars, electrodes and resistive elements. On top of the top sheet is a metal (eg, copper) foil 19, which is held in place by an outer insulating polymer sheet 20. The end portions of the insulating polymer sheet 20 are fixed to the end portions of the sheet 18 by adhesive layers 22 and 23 or melt bonding (not shown). As shown in FIG. 2, the electrode has a width t.
And having a flow l and separated by a distance d, the busbar has a width x. Typical values for these are: t 0.08 to 0.51 cm (0.03 to 0.2 inches) l 6.35 to 15.24 cm (2.5 to 6.0 inches) d 0.25 to 0.76 cm (0.1 to 0.3 inches) x 1.02 to 2.04 cm (0.4 to 0.8 inches) Inches).

FIG. 3 is a cross-sectional view of a self-regulating strip heater having a constant cross section along its flow. The long strip 1 of PTC conductive polymer has a concave end coated with contact layers 2 and 3 of ZTC conductive polymer, the resistivity of which is a fraction of the resistivity of PTC conductive polymer at room temperature. Non-hollow or stranded long wires 5 and 6
Are pressed against the contact layers 2 and 3 respectively by an insulating polymer jacket 7 FIGS. 4 and 5 show a layered conductive polymer resistance element.
Figure 3 shows a heater similar to Figures 1 and 2 with a heating element having 11. Containing graphite or a mixture of graphite and carbon black as a conductive filler, resistance element
A comb pattern 30 of a resistive conductive polymer composition having a resistivity that is substantially lower than the eleven conductive elements is printed on the upper surface of the resistive element 11. A comb-shaped electrode 32 made of a conductive polymer containing a metal (for example, silver) as a conductive filler and having a lower resistivity than the conductive polymer in the resistance pattern 30 is printed on the resistance pattern 30. The shape of the electrode 32 is similar to that of the lower printed layer 30, but the electrode is narrower than the lower printed layer. Thus, layer 30 extends between electrode 32 and resistive element 11 and extends slightly beyond electrode 32. Bus bars 15 and 16 are provided similar to the device of FIGS. 1 and 2. An insulating jacket in the form of a lower polymer sheet 17 and an upper polymer sheet 18 fixed by an adhesive 21 or a melt bond is provided in the same manner as the device of FIGS. 1 and 2, and a metal foil 19 is provided, It is secured in place by adhesive layers 22 and 23 or an insulating polymer sheet 20 which is secured to sheet 18 by melt bonding. The width t and the length l of the electrode 32 are the same as those of the electrodes 12 and 13 shown in FIG. The width t'and separation distance d'of the lower print layer 30 is t'0.15 to 1.02 cm (0.06 to 0.4 inches) d'0.25 to 0.76 cm (0.1 to 0.3 inches).

[Examples] The present invention will be described in more detail below with reference to Examples.

Example 1 The heater of FIGS. 1 and 2 was manufactured as follows.

0.04 cm (0.0175 inch) thick with the following ingredients
Sheet was melt extruded at 232 ° C (450 ° F). Ingredients Polyvinylidene fluoride (Kynar) 79.
7 wt% carbon black (Vulcan XC-72) 10.2 wt% fillers and other additives 10.1 wt% Sheets were irradiated with a dose of 14 megarads to crosslink the polymer. The resistivity of the crosslinked composition at 23 ° C. was 3,500 Ω · cm. The sheet was heated and cut into strips 18.42 cm (7.25 in) wide. By screen-printing the graphite and silver-containing composition on the strip and drying,
The electrode pattern shown in FIG. 1 was created on the strip.
The resistivity of the print composition after drying was about 10 ⁻⁴ Ω · cm. The distance d between adjacent electrodes is 0.64 cm (0.25 inch), the width t of each electrode is 0.16 cm (0.0625 inch), and the length l of each electrode is 13.27 cm (5.4 inch).
Met.

Bend a 3.81 cm (1.5 inch) wide nickel-coated copper stretch metal busbar around the edge of the strip with electrodes, (A) 0.005 cm (0.002 inch) thick silicone adhesive (trade name: Arclad, Adhesives)・ Research Corporation (Adhesives Reseach Corpor)
ation) A commercial product) covering the entire upper surface with a width of 21.6 cm
(8.5 inches) and 0.05 cm (0.020 inches) thick ethylene / chlorotrifluoroethylene copolymer (Harlar) bottom sheet and (B) placed in contact with the printed electrode, width 1.27.
21.6 cm wide, covering 0.005 cm (0.002 inch) thickness of the same adhesive over cm (0.5 inch) at the lower surface edge
(8.5 inches) and 0.025 cm (0.010 inches) thick ethylene / chlorotrifluoroethylene (Hala
r)) was laminated between the upper sheet. Stacked at 52 ° C (125 ° F) and 690KPa
(100 psi). There was no adhesive between the top sheet and the busbar, or between the top sheet and the conductive polymer sheet, or between the top sheet and the electrodes. Thickness 0.005 cm (0.002
Inch) and 18.42 cm (7.25 inch) wide copper sheet placed on the exposed surface of the top sheet and 21.6 cm (8.5 inch) wide
And a 0.01 cm (0.005 inch) thick ethylene / chlorotrifluoroethylene (Halar) outer sheet placed on a copper sheet, with 1.27 cm (0.5 inch) wide and 0.005 cm (0.002) thick at the edge of the outer sheet. Inch) was laminated [52 ° C (at 125 ° F and 690KPa (100psi)] to the edge of the bottom sheet (not copper foil) via an arcrad adhesive. Adhesive between outer sheet and copper foil There was no.

Example 2 Prior to applying the electrode pattern to the strip, a composition having a resistivity (ie, the value between the resistive element and the electrode) of about 0.1 Ω · cm was deposited on the strip by screen printing and then dried. The first described in Example 1 except that a lower print layer comprising graphite having is formed.
The heater shown in FIG. 4 was manufactured in the same manner as the heater shown in FIGS. The electrodes were then screen printed for direct overlay onto the lower print layer. The width of the comb portion of the lower print layer was twice the width of the electrode. The width t of each electrode is 0.16 cm (0.0625 inch), and the width t'of the comb-shaped portion of each lower print layer is 0.32 cm (0.12 cm).
5 inches). The distance d'between adjacent combs of the lower print layer was 0.64 cm (0.25 inch).

[Brief description of drawings]

FIG. 1 is a sectional view of a first sheet heater of the present invention, FIG. 2 is a plan view of a resistance element, a contact layer and a connecting member of FIG. 1, and FIG. 3 is a sectional view of a strip heater of the present invention. FIG. 4 is a cross-sectional view of the second seat heater of the present invention, and FIG. 5 is a plan view of the resistance element, contact layer, separate member and connecting member shown in FIG. 1 ... strip, 2,3 ... contact layer, 5,6 ... wire, 7
...... Insulation jacket, 11 ...... Resistance element, 12,13,32 ...... Electrode, 15,16 ...... Bus bar, 17,18,20 ...... Sheet, 19 ......
Metal foil, 21,22,23 …… Adhesive layer, 30 …… Print layer, t,
t ', x ... width, l ... length, d, d' ... distance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michael Chillards Johns United States 94538 Californier, Fremont, Shweutd Street 41830 (72) Inventor Rabinder Kay Ozwol United States 94086 Californier, Sunnyvale, Reed Avenyu 1111 Ai (72) Inventor Jev Sheif United States 94063 Calif Ornia, Lettuce City, Spring Street 3323 (56) Reference JP 55-122381 (JP, A) JP 55-151782 ( JP, A) JP-A-51-48843 (JP, A)

Claims (22)

(57) [Claims] 1. A resistive element made of a first conductive material having a resistivity of 1 to 500,000 Ω · cm at 23 ° C., and (2) a first conductive material directly bonded to the surface of the resistive element at 23 ° C. Layer made of a second conductive material having a resistivity lower than that of the conductive material, and (3) connection made of a third conductive material having a resistivity lower than that of the second conductive material at 23 ° C. An electrical appliance comprising a member, wherein the connecting member is in direct physical contact with the contact layer and has an area of at least 3.23 cm ² (0.5 square inch) or at least one dimension of 2.54 cm (1 inch). ) Maintaining such contact substantially only by pressure over a larger connection area, such that when the device is connected to a power source, the electrical path is from the connection member through the contact layer to the resistance element, An appliance in which a contact layer and a connecting member are arranged. 2. The resistivity of the second conductive material is 10 ⁻⁶ at 23 ° C.
10 is a ³ Omega · cm, the resistivity of the first conductive material at 23 ° C.: the ratio of the resistivity of the second conductive material is at least 20: 1, the connecting member first claims made of a metal The device according to paragraph. 3. At least one of the first conductive material and the second conductive material is a conductive polymer comprising an organic polymer and a particulate conductive filler dispersed in the polymer. The apparatus according to Item 2 or Item 2. 4. The first conductive material and the second conductive material are a first conductive polymer and a second conductive polymer, respectively, and the conductive filler in the first conductive polymer is graphite,
Claims comprising carbon black or both, wherein the conductive filler in the second conductive polymer comprises one or more selected from the group consisting of metals, graphite and carbon black. The device according to item 3. 5. The device according to claim 3, wherein the first conductive polymer exhibits PTC behavior in the operating temperature range of the device. 6. The resistivity of the first conductive polymer is 50 to 23 ° C.
100,000 Ω · cm, the resistivity of the second conductive polymer is 2
The device according to claim ⁵ , which has a temperature of 3 ° C to 10 ^{-5 to 1} Ω · cm. 7. At least two connecting members in the form of a long continuous metal connecting member which can be connected to a power source, conducts current through the resistive element and makes substantially continuous contact with the respective resistive element via respective contact layers. Claim 1 comprising
~ The device according to any one of 6 to 6. 8. The resistive element is a layered element having substantially flat surfaces spaced apart to which the contact layers are bonded, the metal member being substantially pressed against the respective contact layers. The device according to any one of claims 1 to 7, which is a sheet heater having a flat surface. 9. The contact layer extends beyond the area in contact with the metal member to provide a plurality of comb electrodes.
The device according to any one of paragraphs. 10. The resistive element is in the form of a strip having spaced apart concave surfaces to which the contact layers are bonded, the metal members being substantially complementary pressed against the respective contact layers. 8. The appliance according to claim 7, which is a strip heater having a convex surface. 11. The device according to claim 1, wherein there is no direct physical contact between the resistance element and the connecting member. 12. A resistive element made of a first conductive material having a resistivity of 1 to 500,000 .OMEGA.cm at 23.degree. C., and (2) a first conductive material directly bonded to the surface of the resistive element at 23.degree. Layer made of a second conductive material having a resistivity lower than that of the conductive material, and (3) (a) the third conductive material is (i) an organic polymer, and a conductive filler dispersed in the organic polymer. (Ii) from a third conductive material having a resistivity at 23 ° C greater than 1x10 ^-5 Ω · cm but less than the resistivity of the second conductive material at 23 ° C. And (b) an electrical device having a separate member that is in direct physical contact with the contact layer, such that when the device is connected to a power source, the electrical path is from the separate member to the resistive element through the contact layer. An electric appliance on which a resistive element, a contact layer and a separate member are arranged. 13. The resistivity of the second conductive material is 0.5 × 10 at 23 ° C.
13. The method according to claim 12, wherein the ratio of the resistivity of the second conductive material at 23 ° C. is ^{−2 to} 0.1 Ω · cm and the resistivity of the third conductive material is 5: 1 to 10,000: 1. Equipment. 14. At least one of the first conductive material and the second conductive material comprises an organic polymer and a particulate conductive filler dispersed in the polymer.
The device according to item 12 or 13. 15. The first electrically conductive material, the second electrically conductive material and the third electrically conductive material are a first electrically conductive polymer, a second electrically conductive polymer and a third electrically conductive polymer, respectively. The conductive filler in the second conductive polymer comprises graphite, carbon black or both, and the conductive filler in the third conductive polymer is selected from the group consisting of metal, graphite and carbon black. Claims comprising only one or more claims
The device described in paragraph 14. 16. The device according to claim 12, wherein the first conductive material is a conductive polymer that exhibits PTC behavior in the operating temperature range of the device. 17. A device as claimed in any one of claims 12 to 16 in which the separate member is bonded to the contact layer. 18. The device according to claim 12, wherein there is no direct physical contact between the resistance element and the separate member. 19. The resistive element is a layered element having spaced apart substantially planar surfaces to which respective contact layers are bonded, each separate member when connected to a power source. An apparatus according to any of claims 12-18, wherein an electric current is coupled to the contact layer so as to provide a plurality of electrodes for passing a resistive element therethrough. 20. The device of claim 19 wherein the electrodes are such that the current therethrough lies in the plane of the resistive element. 21. The spaced apart substantially flat surfaces are coplanar and the electrodes are comb-shaped.
The equipment described in paragraph 20. 22. The device according to claim 12, wherein the contact layer has a shape similar to that of the separate member and extends beyond the separate member.