JPH0831611A - High molecular temperature sensor and temperature sensing element - Google Patents

Abstract

PURPOSE:To increase the dependency of impedance on temperature using the composition formed by blending at least manganese iodide to polyamide as a temperature sensor. CONSTITUTION:The title high molecular temperature sensor is composed of a polyamide composition which is formed by comounding at least manganese iodide to polyamide. The manganese iodide is composed of a kind selected from a manganese iodide non-hydrate and a manganese iodide hydrate, the polyamide composition contains oxybenzoate and a formaldehyde polycondensate, the polyamide is a high molecular temperature sensor consisting of at least a kind selected from polyamide and its copolymer and containing polyundecane amide, polydodecane amide, polyamide containing C13 or more of straight-chain saturated hydrocarbon and its copolymer, an N-alkyl sabstituted amide copolymer, an etheramide copolymer of polyundecane amide or polydodecane amide, and dimer acid containing polyamide, and a temperature sensing element using the high molecular temperature sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymeric temperature sensor used for a flexible temperature sensor such as an electric heating tool or a temperature sensitive heater.

[0002]

2. Description of the Related Art Conventionally, a polymer temperature sensor is generally arranged between a pair of winding electrodes and used as a flexible linear temperature sensor or a heat sensitive heater. Examples of this polymer temperature sensitive material include nylon 12 and modified nylon 11 (ATO-CHIMI) disclosed in Japanese Patent Laid-Open No. 55-100693.
A polyamide composition such as "Rilsan N Nylon" manufactured by E Co., Ltd.) is used, and its temperature change such as capacitance, resistance value or impedance is used to fulfill the function of a temperature sensor. Further, in JP-B-60-48081, a polyamide composition containing a phosphite ester as a heat deterioration improving agent is disclosed, and in JP-A-64-30203, ion-conducting composition containing a copper deactivator and a phenolic antioxidant. Examples of heat-sensitive compositions are disclosed.

[0003]

Nylon 12 is excellent in that it has a low moisture absorption rate, but it is difficult to put it into practical use as a temperature sensor, because its temperature-sensitive characteristics vary greatly depending on humidity. Further, in the modified polyamide disclosed in JP-A-55-100693, the temperature dependence of impedance is small, so that the temperature detection sensitivity is low and the heat resistance stability is poor. Therefore, in order to improve humidity resistance and temperature sensitivity, a composition containing an aldehyde polycondensate of a phenolic compound has been proposed as disclosed in Japanese Patent Publication No. 3-50401. However, all of these have problems that the temperature dependence of impedance is low and the thermal stability for a long period of time is insufficient.

It is an object of the present invention to provide a polymer temperature sensitive body having a large impedance temperature dependency and excellent thermal stability.

[0005]

According to the present invention, a composition in which at least manganese iodide is mixed with polyamide is used as a temperature sensing element, and the above-mentioned polymer temperature sensing element is disposed between a pair of electrodes as a temperature sensing element. And then configure.

[0006]

In general, the polymer temperature sensor is disposed between a pair of copper or copper alloy winding electrodes and is used as a flexible linear temperature sensor or a heat sensitive heater. The heat resistance stability of these temperature sensors and heat sensitive heaters is determined by the stability of the polymer temperature sensor itself and the surface condition of the winding electrode. When the above-mentioned polyamide composition is used, the temperature dependence of the impedance is remarkably enhanced by the ion carrier property of manganese iodide in the polymer thermosensitizer, and a manganese complex is formed in the amide group to enhance the electrical stability. , Is also thermally stable. Therefore, the thermal stability of the polymer temperature sensor is improved,
As a temperature sensor and a heat sensitive heater, it is considered that the heat resistance stability is remarkably increased. Further, by blending an aldehyde polycondensate of a phenol compound, a strong moisture absorption preventing effect can be imparted. Phenolic compounds have good compatibility with polyamides and coordinate with hydrogen bonding sites instead of water molecules in polyamides to reduce hygroscopicity and reduce fluctuations in temperature-sensitive characteristics due to humidity. Further, the action on the amide group also has the effect of increasing the temperature sensitivity.

[0007]

EXAMPLES Examples of the present invention will be described below. In the examples of the present invention, as the polyamide, nylon 12 having a low hygroscopic property, nylon 12-nylon 40 copolymer,
N-alkyl substituted polyamide 11, polyether amide and dimer acid containing amide were selected. Manganese iodide, which has high thermal stability, was used as a conductivity-imparting agent that increases the temperature dependence of impedance of these polymers. Further, in an example in which an aldehyde polycondensate of a phenol compound was added, 15 parts by weight of an oxybenzoic acid octyl ester-formaldehyde polycondensate having good compatibility with polyamide was selected. A sample was prepared by blending these and kneading them with an extruder, and then forming into a sheet of about 70 × 70 mm and a thickness of 1 mm by a hot press, and providing silver-coated surface electrodes on both sides thereof. The temperature dependence of impedance is represented by the thermistor B constant at 40 to 80 ° C. In addition, the heat resistance stability is 1% of the initial impedance and 100 V half-wave current at 100 ° C.
Temperature difference from impedance after 000 hours (ΔT
_z ). Thermistor B at 40-80 ℃
Constants are impedance Z _{40 at} 40 ° C and 80 ° C
It was calculated based on the result of measurement of the impedance Z ₈₀ at.

The results are shown in (Table 1).

[0009]

[Table 1]

Anhydrous manganese iodide is used as the sensitizer of the present invention and contributes to the improvement of the thermistor B constant.

As the aldehyde polycondensate of the phenolic compound, p-oxybenzoic acid octyl ester-aldehyde polycondensate and p-oxybenzoic acid isostearyl ester-formaldehyde polycondensate are compatible and moisture resistant. However, aldehyde polycondensates such as p-dodecylphenol, p-chlorophenol, and p-oxybenzoic acid nonyl ester may be used in addition to p-oxybenzoic acid alkyl ester. These are mixed in 5 to 30 parts by weight with respect to the polyamide. If it is less than 5 parts by weight, the effect is low, and if it is more than 30 parts by weight, the properties of the composition are significantly impaired.

Nylon 12 (10
0 parts by weight) and a manganese iodide (1.0 parts by weight) nylon blend pellet were prepared, and the pellet was used to prepare a thermosensitive element, that is, a temperature detection line as shown in FIG. Here, each component will be described as follows.
Is 1500 denier polyester core yarn, 2 and 4 are 0.
5% silver-filled copper electrode wire, 3 a nylon temperature-sensitive layer, a polyester separation layer, and 6 a heat-resistant vinyl chloride jacket. That is,
A thermosensitive element is constructed by disposing a polymer thermosensor between a pair of electrodes. The thermistor B constant of the temperature sensing element is
For comparison, the thermistor B constant of a prototype having a temperature sensitive layer formed only of nylon 12 is 8800 (K), which is more than 5 times that of 1500 (K), and is continuous at 100 ° C as a heat resistance life test. It showed a durability of 2000 hours or more against 100 V half-wave.

[0013]

As described above, according to the present invention, the incorporation of manganese iodide is effective in many practical applications because it improves the thermistor B constant and stabilizes the mechanical strength and electrical characteristics for a long period of time even at high temperature. The reliability of various uses can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a temperature detection heater wire using a temperature sensing element.

[Explanation of symbols]

 1 Polyester core yarn 2, 4 Electrode wire 3 Nylon temperature sensitive layer 5 Polyester separation layer 6 Vinyl chloride jacket

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Claims (5)

[Claims] 1. A polymer thermosensitizer comprising a polyamide composition in which a polyamide is blended with at least manganese iodide. 2. The polymer thermosensitizer according to claim 1, wherein the manganese iodide is one selected from manganese iodide anhydrate or manganese iodide hydrate. 3. The polyamide composition comprises oxybenzoic acid ester and formaldehyde polycondensate.
The polymer thermosensitive material described. 4. The polymeric temperature sensitive body according to claim 1, wherein the polyamide comprises at least one selected from the group consisting of the following (a) to (f). (A) Polyundecane amide (b) Polydodecanamide (c) Polyamide containing linear saturated hydrocarbon C ₁₃ or more and its copolymer (d) Polyundecane amide or N-alkyl-substituted amide copolymer of polydodecane amide (E) Ether amide copolymer of polyundecane amide or polydodecane amide (f) Polyamide containing dimer acid 5. Claim 1, claim 2, claim 3, claim 4
A thermosensitive element comprising the polymer thermosensor according to any one of claims 1 to 5 arranged between a pair of electrodes.