JPS61100902A - Positive temperature characteristic resistance element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a resistance element having positive temperature characteristics.

BACKGROUND ART Conventionally, a positive temperature characteristic resistance element is known in which a metal foil is attached by pressure bonding to a molded body having positive temperature characteristics (US Pat. No. 4,426,633). In this case, in order to keep the resistance value of the element itself low, it is necessary to reduce the wall thickness of the molded body, or to reduce the size of the molded body (vertical 1. It is necessary to increase the width 1). However, there is a limit to the wall thickness in terms of molding, and it is not preferable to reduce the wall thickness of the molded product too much because this will reduce the withstand voltage. On the other hand, the dimensions of the molded body (
Increasing the vertical (1) and horizontal (1) dimensions often causes problems when incorporating the device into equipment.

An object of the present invention is to provide an element that can reduce the resistance value of the element by increasing the electrode area as much as possible without increasing the dimensions of the element.

That is, the present invention provides a positive temperature characteristic resistance element which is an alternately laminated product of resistor portions and electrode portions having positive temperature characteristics, and in which every other electrode portion is connected.

In the present invention, the resistor portion having positive temperature characteristics includes:
A material whose electrical resistance value increases as the temperature rises is used. For example, a thin layer such as a sheet made of a mixed wire composition obtained by blending and kneading a crystalline polymer and conductive particles is used.

Here, the crystalline polymer is not particularly limited and can include various types, but usually polyolefins such as high-density polyethylene, low-density polyethylene, polypropylene, ethylene-propylene copolymers, and olefin copolymers are used. These include polymers, various polyamides, polyesters, fluorine-based polymers, and modified products thereof.

Next, various types of conductive particles can be used. Specific examples thereof include carbon blanks such as tourness black, thermal paste, and acetylene black; graphite; metal particles; and mixtures thereof, with carbon black, graphite, and mixtures thereof being particularly preferred. Further, the average particle diameter of the conductive particles is 10 mμ to 1 μm, preferably 15 mμ to 1 μm.
00 mμ.

The blending ratio of each component is not particularly limited and varies depending on the desired physical properties, etc., and cannot be determined unambiguously, but usually 15 to 150 parts of the above conductive particles are added to 100 parts by weight of the crystalline polymer. It is blended in an amount of 40 to 120 parts by weight, preferably 40 to 120 parts by weight. If the amount of conductive particles blended is less than the above ratio, the specific resistance at room temperature, that is, the initial resistance value of the resulting composition will increase, and conversely, if it is too much than the above ratio, the resistance value will increase in a specific temperature range. rate decreases.

The material of the resistor portion having positive temperature characteristics in the present invention is as follows:
It is manufactured by blending a predetermined amount of conductive particles into the crystalline polymer and then thoroughly kneading the mixture. This cross-mixing may be carried out using a conventional cross-mixing machine such as a Banbury mixer, and is usually carried out at 120 to 250 DEG C. for 5 to 40 minutes. The cross-wire composition thus obtained is formed into a thin layer such as a sheet or film by thermoforming or the like and used.

In addition, after kneading the above-mentioned two components, it is preferable to carry out crosslinking before thermoforming or after molding.

Crosslinking can be carried out by various means, such as a method of adding a crosslinking agent such as an organic peroxide, a method of using ozone, a method of irradiating an active energy gland such as an electron beam, and the like. Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide,
t-Butylcumyl peroxide # Examples include t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, and the like. When using this organic peroxide as a crosslinking agent,
0.05 per 100 parts by weight of the crystalline polymer
-3 are added at the same time.

The positive temperature characteristic resistance element of the present invention includes a resistor portion having the above-mentioned positive temperature characteristic and IE! It is an alternate laminate with parts. Here, as the electrode part, metal foil, metal plate, metal mesh, conductive paint, or conductive adhesive is used. Further, as for the type of metal, any metal having good conductivity may be used, and various metals can be used. In particular, as the metal foil, electrolytic nail foil, electrolytic nickel foil, etc. are preferably used. Further, the metal foil preferably has a roughened surface. Such electrode portions and resistor portions having positive temperature characteristics are alternately stacked on top of each other by hot pressing or the like to form an alternate laminate of the two. There is no particular restriction on the method of lamination, as long as the result is an alternate lamination of the above two materials. Note that the outermost layer of this alternately laminated product is an electrode portion. Specifically, as shown in FIG. 1, for example, a metal foil 1 with roughened surfaces on both sides, which will serve as an electrode part, is sandwiched between the two, a resistor 2 having positive temperature characteristics is sandwiched, and the outermost layer is made of metal. It can be obtained by overlapping the foils K. In addition, as shown in Fig. 2(a), a resistor 2 having positive temperature characteristics was sandwiched between metal foil 1 with one side roughened, and this laminate (laminated unit) was further Ic! A plurality of resistor parts and electrode parts B having positive temperature characteristics may be laminated in an alternating manner as shown in FIG. 2(b). In this case, the metal foils 1 overlapped in the middle form one electrode section B.

In the positive temperature characteristic resistance element of the present invention, every other electrode part of the above-mentioned alternate laminate is connected to form each electrode.

That is, every other stacked electrode section is joined at its end portion. Note that the ends of the metal foil 1 that will become the electrode part B are arranged so that they alternately protrude from the resistor 2 having positive temperature characteristics when they are connected, and these protruding parts are joined by soldering or conductive adhesive. Bye. In the figure, the symbol H indicates a soldered part. If necessary, lead wires are soldered to the respective electrodes thus joined and formed. Sara K
After the lead wires are attached, the surface can be protectively coated with an insulating material, preferably a heat-resistant resin.

A positive temperature characteristic resistance element can be obtained in the manner described above. According to the present invention, the electrode area can be made as large as possible without increasing the dimensions of the element (vertical 1 x width 1), and as a result, the electrical resistance value of the element is significantly reduced compared to the conventional one. can be converted into

Therefore, the positive temperature characteristic resistance element of the present invention can be effectively used in temperature regulators, fuses, and the like.

Next, examples of the present invention will be shown.

Example 1 As a positive temperature characteristic resistor, 100 parts by weight of high-density polyethylene (manufactured by Idemitsu Petrochemical Co., Ltd.: Idemitsu Polyethylene 540B) was mixed with carbon black (manufactured by Mitsubishi Chemical Industries, Ltd.): Diablack E with an average particle size of 43 mμ. 2.5-dimethyl-2,5-
A sheet having a wall thickness of 0.7 nm that was crosslinked by adding 0.5 parts by weight of di(t-butylperoxy)hexyne-3 and then molded by hot pressing was used.

Using three of these positive temperature characteristic resistor sheets, sandwiching between each sheet an electrolytic steel foil with a wall thickness of 70μ with roughened surfaces on both sides, which will serve as the electrode part, and the outermost layer of the laminate thus obtained. Electrolytic steel foils having a wall thickness of 35 μm and having been roughened on one side were stacked on top of each other and hot pressed at 190° C. and a pressure of 150°/α2G for 10 minutes to obtain a laminate with a wall thickness of 2 m. During lamination, the ends of the electric ME foils were stacked in advance so that they alternately protruded from the ends of the sheets. Next, this! Every other protrusion of the electrolytic copper foil of the R calendar body was joined with a solder to obtain a positive temperature characteristic resistance element as shown in FIG.

The obtained element surface had a size of 20 m in length and 10 m in width, and the resistance value between the electrodes was measured by the four-probe method, and the result was 25 m.
The resistance value of the element at °C is 0.0270 and 150
The ratio of the resistance value at 25° C. to the resistance value at 25° C. (resistance increase magnification) was 1004.1.

Example 2 A positive temperature characteristic resistor sheet with a wall thickness of 0.7 nm, which is the same as in Example 1, was used as a positive temperature characteristic resistor, and on both sides of this resistor sheet, electrolytic copper foil with a wall thickness of 35 μm with one side roughened was coated. By overlapping and hot pressing, a laminate (laminated unit) having a wall thickness of 0.7 mm as shown in FIG. 2(a) was obtained. 10 lengthwise and 20 width pieces were cut out from this laminate, and the three pieces were stacked one on top of the other in three layers.

Next, every other protruding end of the nine-layer electrolytic copper foil was joined by solder to obtain a positive temperature characteristic resistance element as shown in FIG. 2(b).

As a result of measuring the resistance value between the electrodes using the four-probe method for the element obtained by heating in this way, the resistance value of the element at 25°C was 0.0270, and the resistance increase magnification when the temperature was raised by 150"GK. was 10 to the 4.1 power.

Example 3 A laminate was obtained in the same manner as in Example 1 except that two positive temperature characteristic resistor sheets were used. 10rm vertically from this laminate, tf! ! A small piece of 20 m in length was cut, and the electrolytic copper foils on the front and back surfaces of the small piece were joined together to obtain a positive temperature characteristic resistance element as shown in FIG.

The resistance value of the element thus obtained at 25°C was 0.0370, and the resistance increase factor when the temperature was raised to 150°C was 1004.1.

Comparative Example 1 Electrolytic copper foil with a thickness of 35 μm with one side roughened was coated on both sides of the laminate prepared in the previous step of Example 2, that is, a positive temperature characteristic resistor sheet as shown in FIG. 2 (arc). A laminate obtained by overlapping and hot pressing (laminated M
A small piece measuring 10 squares in length and 20 irz in width was cut out from a small piece (early) to form an element.

The resistance value ffi+I of this element at 25° C. was determined to be 0.080, and the resistance increase factor when the temperature was raised to 150° C. was 10 to the 4.1 power.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the first embodiment of the positive temperature characteristic resistance element of the present invention, and FIG. 2 is an explanatory diagram of the second embodiment of the positive temperature characteristic resistance element, in which the solid state is the basic one. It is a perspective view of a laminated body (laminated unit), and the same figure (1) is a perspective view which shows a 2nd aspect. FIG. 3 is a perspective view showing a third embodiment of the positive temperature characteristic resistance element of the present invention. A.-Resistor portion having positive temperature characteristics. B...electrode part. 1...Metal foil 6 2...Resistor with positive temperature characteristics Fig. 1 (a) (bJ Fig. 3

Claims (5)

[Claims] (1) A positive temperature characteristic resistance element, which is an alternately laminated product of resistor parts and electrode parts having positive temperature characteristics, and in which every other electrode part is connected. (2) The device according to claim 1, wherein the resistor portion having positive temperature characteristics is made of a kneaded composition of a crystalline polymer and conductive particles. (3) The device according to claim 1, wherein the electrode portion is made of metal foil, metal plate, metal mesh, conductive paint, or conductive adhesive. (4) The element according to claim 3, wherein the metal foil has a roughened surface. (5) The element according to claim 3 or 4, wherein the metal foil is copper foil or nickel foil.