JPS63236232A - Thermosensitive switch - 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] Industrial Application Field The present invention relates to a heat-sensitive switch, and is suitable for use as an overheat preventer, an overheat alarm, a fire alarm, and other heat-sensitive switches or temperature sensors that are widely used in industry today. can be used.

Conventional technology A so-called bimetal thermal switch has contacts attached to a plate made by bonding two metal pieces with different coefficients of thermal expansion, and the contacts are actuated by warping of the plate due to heating.The contacts are actuated by utilizing the thermal expansion of a liquid. A so-called giratameter type heat-sensitive switch, a so-called thermocouple-type heat-sensitive switch whose contacts are actuated by the electromotive force of a thermocouple, and a so-called platinum resistor-type heat-sensitive switch whose contacts are actuated by a change in the resistance of a platinum resistor are all well known.

Problems to be Solved by the Invention The present invention solves the problem of how to provide a reliable and inexpensive heat-sensitive switch using an hour wheel.

The above-mentioned various heat-sensitive switches obtained by conventional techniques cannot be said to have no melting point from the point of view of economy or reliability. That is, the most inexpensive Hi-Mekuru type angry heat switch has the problem of unstable operation due to poor contact due to the adhesion of flakes or the occurrence of rust. A dilatometer complete heat-sensitive switch is inexpensive, but it is difficult to miniaturize it.

Thermoelectric control and platinum resistor type heat-sensitive switches have the problems of being complicated in structure and expensive.

Means for Solving the Problems As a result of extensive studies on the electrical properties of imidazole compounds, the present inventor found that, unexpectedly, imidazole unsubstituted at the 1-position shows almost no electrical conductivity in the solid state. The unsubstituted imidazole at the 1-position shown by the general formula is sealed in a closed container equipped with two electrically insulated electrodes, and both electrodes are connected by the melted product of the filling that is generated when external heating is performed. By making an electrical connection, the intended purpose was achieved.

The resistance value of the 1-position unsubstituted imidazole used in the present invention is 0 when determined by dipping the needle tip into the melt for 2 to 3 times using a tester with a needle-shaped electrode at an electrode spacing of 9M.
．． The resistance is approximately 0001 to 0.0008Ω, and exhibits remarkable electrical conductivity compared to the solid state, which conducts almost no current.

Representative 1-position unsubstituted imidazoles and their melting points in the present invention are as follows.

Imidazole (m, P, 90-91 °C), 2-methylimidazole (m, P, 145-147 °C), 2
-ethylimidazole (m, P, 69-82°C),
2-isopropylimidazole (m, r', 128~
133°C), 2-undecylimidazole (m, P,
69-74°C), 2-heptadecyl imidazole (
m, P, 86-91 °C), 2-phenylimidazole (m, P, 137-147 °C), 2-orthotolylimidazole (m, P, 141-142 °C),
2-Metatolylimidazole (m, P, 199-2
00°C), 2-benzylimidazole (m, P, 1
26°C), 4-methylimidazole (m, P, 56
°C), 2,4-dimethylimidazole (m, P, 9
2°c), 2-phenyl-4-methylimidazole (m
, P, 163-180°C), 2-phenyl-4-benzylimidazole (m, P, 166-170°C) A mixture of two or more of the above imidazoles can be melted by the generally well-known melting point depression phenomenon. , has a melting point lower than the south point of each constituent component, so if necessary, the mixture can be used in the method of the present invention. For example, 2-undecylimidazole (m, I', 69-74°C) and 2-heptadecyl imidazole (m, P, 86-91
The melting point of an equimolar mixture of 67-70°C) is 67-70°C.

When the crystalline powder, crystalline molten solid, or compression-molded body of crystalline powder made of imidazole is sealed in a closed container equipped with two electrodes electrically insulated from each other, and heated from the outside, Eventually the inclusions reach their melting point and melt.

Since the melt is a liquid, it is leveled by gravity and connects the two electrodes, creating a conductive circuit.

If any one of the imidazoles mentioned above is chosen as the filler, the circuit will operate at the corresponding melting point temperature. Also, if a mixture of two or more types is selected and used as an inclusion,
The circuit also operates at the melting point of the corresponding material. That is, the operating temperature can be set arbitrarily to some extent by selecting the filler material.

If a compression-molded body of a crystalline molten solid or a crystalline powder is used as an enclosure, and the outer shape of the enclosure is columnar, cylindrical, or spherical with a maximum diameter (length) shorter than the electrode spacing, the temperature below the melting point, i.e. During the storage period until operation, the enclosed material cannot be connected between the electrodes, so it is impossible for even a weak current to flow between the two electrodes (this is advantageous in saving power for the operating power source).

Any material can be used for the electrode as long as it has conductivity. These are, for example, carbon rods, cavities and copper alloys, zinc and zinc alloys, iron, nickel, aluminum or metal plated with precious metals.

The shape of the electrode is arbitrary. The material of the airtight container is also arbitrary. For example, any material such as glass, synthetic resin, or metal can be used. Although the shape of the closed container is arbitrary, a tubular container is most readily available and economical. The airtight container can be replaced with an inert gas or can be evacuated. The insulation sealing may be performed using an epoxy resin, or may be performed using a pressure-bonding method such as a dry battery method using an elastic synthetic resin backing.

Effects of the Invention According to the present invention, a simple, reliable, and inexpensive thermal switch can be provided.

Example 1 A glass tube with an inner diameter of 4M, an outer diameter of 5mm, and a total length of 30mm has an outer diameter of 3mm.
2-undecylimidazole, which had been compression molded into a cylindrical shape with a length of 15 mm and a total length of 15 mm, was placed in the tube, and then two zinc ribbons with a length of 30 nnn, a thickness of 0.5 mm, and a width of 2 mm were placed 5 mm inside each end of the glass tube. , press both ribbons against the glass wall on the same side with a plastic disk,
Then, both ribbons and the glass tube were completely adhesively sealed with epoxy resin.

(Place the resulting heat-sensitive switch horizontally with both ribbon electrodes facing down, and contact the tester between both electrodes.
When the switch was heated externally, it was found to work at about 70°C. After cooling, it was heated again and operation was confirmed. It has been found that this repetitive operation is possible at least 20 times.

Example 2 An equimolar mixture of 2-undecylimidazole and 2-heptadecyl imidazole was compression molded into a cylinder with an outer diameter of 3 and a total length of 15 mm, and this was used in place of 2-undecylimidazole in Example 1. , the same thing as in Example 1 was carried out. This heat sensitive switch was found to operate at approximately 68°C and was found to be capable of repeated activation at least 20 times.

Claims (2)

[Claims] (1) A solid packing containing as an essential component any one of the 1-position unsubstituted imidazoles represented by the following general formula, or a mixture of two or more thereof, is mutually 1. A heat-sensitive switch characterized in that the switch is sealed in a closed container having two electrically insulated electrodes, and the electrodes are electrically connected by a melt of the filling material generated during external heating. General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, R_2 represents a hydrogen atom, an alkyl group, a benzyl group, or a tolyl group, and R_4 represents a hydrogen atom, a methyl group, or a benzyl group. (2) The heat-sensitive switch according to claim 1, wherein the solid filling is a crystal powder, a crystal molten solid, or a compression molded product of crystal powder.