JPH0855708A - Polymer temperature sensor and heat-sensitive heater wire - Google Patents

Abstract

PURPOSE:To provide a high molecular heat-sensitive material which has an excellent heat resistance and high thermistor B constant and does not make any change by aging even when the material is subjected to DC polarization. CONSTITUTION:A high molecular heat-sensitive material is prepared by mixing the oxyiodide of a Lewis acid metal in a polyamide composition and the iodide of the Lewis acid metal and the basic salt of the Lewis acid metal in heat-stable nylon 12 composition containing ester phosphite as an oxidation inhibitor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer temperature sensor mainly used as a linear temperature sensor for electric heating appliances. This polymer temperature sensing element is used for a temperature sensor of an electric heating appliance such as an electric carpet, floor heating, and an electric blanket, and a heat-sensitive heater wire. The present invention also relates to a heat sensitive heater wire used in these electric heating appliances.

[0002]

2. Description of the Related Art Conventionally, as a temperature control system used for electric heating appliances such as electric blankets and electric carpets, a two-wire system using two separate wires, a flexible wire-like temperature detecting wire and a heater wire. And a one-wire system using a heat-sensitive heater wire that integrates them. These temperature control methods are used in most domestic electric heating appliances made of cloth as a method of preferentially detecting local overheating in a wide area by using a polymer temperature sensor as a temperature sensor material. The temperature sensor used here is a flexible electric wire formed by disposing a polymer temperature sensor between a pair of spiral electrode wires, and has a parallel equivalent circuit in its length direction. . On the other hand, the heater is electrically heated in the length direction of the wire to be a heater.

Among these, the one-wire system has a feature that one heat-sensitive heater wire may be wired in a warming device, and the one-wire system also has a function of a heater and a temperature fuse for safety as well as a temperature detecting function. ing. In addition to the above-mentioned thermal fuse function, high heat resistance is required for the polymer temperature sensor used in the one-wire system, and a high-performance sensor material has been desired. Therefore, for example, a polymer temperature sensitive body to which zinc iodide is added (JP-A-58-215449), a polymer temperature sensitive body to which nickel iodide, cobalt iodide, etc. are added (JP-A-60-106101-). No. 106106) has been proposed.

[0004]

The polymer temperature sensor has 1)
In addition to excellent heat resistance, it is required to have 2) a high thermistor B constant, and 3) not change over time due to direct current polarization, but the above-mentioned reference is not a material that satisfies all of these characteristics. Excellent materials were desired. An object of the present invention is to provide an excellent polymer temperature sensitive body which satisfies the above requirements. Another object of the present invention is to provide a heat sensitive heater wire having an improved heat resistant life.

[0005]

The polymer thermosensitizer of the present invention comprises a polyamide composition containing a oxyiodide of a Lewis acid metal. Here, the polyamide composition is preferably a heat-stable nylon 12 composition containing a phosphite ester as an antioxidant. In this composition, a Lewis acid metal oxyiodide and a Lewis acid metal A composition containing the same Lewis acid metal iodide is desirable.

Further, the polymer thermosensitizer of the present invention comprises a thermostable nylon 1 containing phosphite as an antioxidant.
The two compositions include iodide of a Lewis acid metal and a basic metal salt of the same metal as the Lewis acid metal.
The basic metal salt used here is preferably a basic organic metal salt of a Lewis acid metal ion and a carboxylic acid or an organic acid having a phenolic hydroxyl group. The Lewis acid metal is preferably one kind of metal selected from the group consisting of nickel, chromium and zinc.

The heat-sensitive heater wire of the present invention comprises a pair of metal wire electrodes, one of which also serves as a heater wire, and a layer of a polymer temperature sensor interposed between the metal wire electrodes, and a positive electric field is applied. At least the surface of the metal wire electrode on the side to be formed is composed of the same metal element as the Lewis acid metal. In particular, the Lewis acid metal in the polymer temperature sensor is zinc, and the metal wire electrode on the side to which a positive electric field is applied is preferably a zinc-coated copper wire, a nickel-coated copper wire, or a brass wire. .

[0008]

In the polymer temperature sensor of the present invention having the above-mentioned constitution, the Lewis acid metal oxyiodide added to the polyamide composition serves as an excellent conductivity-imparting agent for the polymer temperature sensor. Here, the Lewis acid metal is a metal element of a metal salt having a Lewis acid property, has an electron pair accepting property, and has a property of accepting an unpaired electron from a Lewis base to form a coordinate bond. The Lewis acid is generally AlCl ₃ , ZnC
Metal halides such as l ₂ , FeCl ₃ , BF ₃ , and SnCl ₄ are the most well known, and the central metal has a property of accepting an electron pair. There are also various organometallic Lewis acids such as trimethylboron. The Lewis acid metal in the present invention is preferably one selected from the group consisting of nickel, chromium and zinc. Although not clearly understood, it is considered that the Lewis acid metal ion preferably has a strong acidity, and the valence is preferably a mixed-valence metal.

On the other hand, the oxyiodide is also called basic iodide, and when the divalent Lewis acid metal is M, the oxyiodide of M is represented by the molecular formula MO · MI ₂ . This compound is a compound composed of a metal oxide and a metal iodide, and is characterized by having extremely high dispersibility when added to a polyamide resin. When the decomposition of this compound proceeds in polyamide over time or thermally, M
It is considered that the I ₂ component is molecularly dispersed in the polyamide and contributes to imparting conductivity, and the MO component is dispersed in the ultrafine particles and serves to supplement the Lewis acid metal ion.

As the polyamide composition of the present invention, it is desirable to use a heat-stable nylon 12 composition containing an antioxidant comprising a phosphite, and in addition to the above-mentioned Lewis acid metal oxyiodide, the above-mentioned Lewis acid is used. In the configuration in which iodide of the same Lewis acid metal as the metal is added, an arbitrary amount of iodide can be added, so that the impedance-temperature characteristic of the polymer temperature sensor can be freely adjusted. Further, in the constitution of the polymer thermosensitizer of the present invention, which is obtained by adding the iodide of Lewis acid metal and the basic metal salt of the same metal as the Lewis acid metal, the basic metal salt is the same as above. It has the same function as the fine-grained MO. As the basic metal salt used here, a basic organic metal salt with a carboxylic acid or an organic acid having a phenolic hydroxyl group is preferable, and this compound has high dispersibility in polyamide.

The nylon 12 composition has a stronger cohesive force between self-molecular chains due to strong hydrogen bonds between amide groups, and few have compatibility with it. However, by selecting the Lewis acid metal iodide, nylon 12
It is compatible with the matrix to impart conductivity, and a preferable high impedance temperature coefficient can be obtained. Since iodide uses iodine, which has a weak electronegativity, as an anion, it is considered that a Lewis acid metal ion having a high ionic property has a higher stabilizing effect for its stabilization. Among them, zinc ions act as strongly acidic Lewis acid metal ions. The amide group has an affinity for this Lewis acid metal ion and forms a coordinate bond. The conductivity here is because the iodide of Lewis acid metal is well compatible with nylon 12, which is a polyamide, and the amide group is coordinated with the Lewis acid metal ion to promote proton conduction. I think that the. Therefore, this impedance-temperature characteristic exhibits excellent life characteristics with little change over time due to electrolysis or polarization even under a DC component electric field.

When the polyamide is decomposed by heat deterioration, the carboxylic acid generated by the decomposition of the amide group reacts with the Lewis acid metal ion to form a salt. That is, the Lewis acid metal ions are trapped by the carboxylic acid, causing a decrease in concentration. One of the amino groups produced by the decomposition of the amide group is also coordinate-bonded to the Lewis acid metal ion to produce an ammine metal ion. The polymer thermosensitive material of the present invention contains an MO component and a basic organic salt component in order to supplement the Lewis acid metal ion deficient due to such a cause. This component is sparingly soluble in the nylon 12 matrix, supplements the deficiency of Lewis acid metal ions that gradually occurs due to the thermal decomposition of amide, and keeps the temperature-sensitive property long. The polymer temperature sensor of the present invention is also required to have a sharp melting point as a thermal fuse function, and to easily electrically short-circuit between metal wire electrodes during melting. From this point as well, the fineness of the particle size and the dispersibility of the MO ultrafine particles are required.

Zinc is a particularly preferred metal ion as the Lewis acid metal as described above, but as an analogy of the action, zinc ion is a condensation catalyst of triphosphate as a zinc enzyme catalyst in the living body, which is a polymerization catalyst for DNA and RNA. (DNA
Polymerase), while phosphoric acid has the relationship of catalyzing the polymerization of polyamide polypeptides. Similar to these relationships, it is also considered that the same interaction is caused even in this polymer temperature sensitive body to make the thermal stability and the conductivity longer. Furthermore, the polymer thermosensitizer of the present invention is preferably at least one selected from the group consisting of nickel, chromium, and zinc as the Lewis acid metal as described above. As the metal wire electrode to which the electric field is applied, the influence on the characteristic change due to the ionization of the electrode is adjusted by the structure having at least the same metal element as the Lewis acid metal on the surface thereof, and thereby the heat resistant life characteristic is further improved. Be improved.

[0014]

EXAMPLES Next, the present invention will be described with reference to examples. The polymer thermosensitive material of the present invention has a structure in which a oxyiodide of a Lewis acid metal is added to a polyamide composition. In order to form a polymer thermosensitive material having an extremely high heat stability, it is desirable to use a heat stable nylon 12 composition containing an antioxidant composed of phosphite as a polyamide composition. In addition to the metal oxyiodide, it is desirable to add the same Lewis acid metal iodide as the Lewis acid metal. There are various kinds of compounds as the oxyiodide, and for example, in the case of zinc oxyiodide, ZnI ₂ .5ZnO.11H ₂ O and Z
There are compounds such as nI ₂ .9ZnO.24H ₂ O. Antioxidants made of phosphite are well known as additives for general resins, and their excellent heat stabilizing effect is disclosed in, for example, Japanese Patent Publication No. 60-48081.

The basic metal salts used in the present invention include basic inorganic metal salts such as basic sulfates, basic phosphites and basic silicates, and basic organic metal salts, each of which has one base. Form salts from basic to tribasic. For example, basic sulphates and basic phosphites have monobasic salts Zn, respectively.
O ・ ZnSO ₄ and dibasic salt 2 ZnO ・ ZnHPO ₃・ H
₂ O etc. In the present invention, a basic organic metal salt with a carboxylic acid or an organic acid having a phenolic hydroxyl group is preferable because it has good dispersibility in a nylon resin. Specific basic organic metal salts include basic phthalates, basic maleates, basic salicylates, and basic oxybenzoates (eg ZnO. (Oxybenzoic acid) 2Zn).
Are preferred.

The above-mentioned various additives to be added to 100 parts by weight of this nylon 12 composition are about 15 parts by weight or less, respectively, and the antioxidant is about 0.2 to 3.0 parts by weight,
The conductivity-imparting agent is about 1 to 8 parts by weight. In the case of additives such as inorganic metal compounds, the addition amount is often required to be about the specific gravity or more depending on the size of specific gravity, solubility in polymer and particle size, but the appropriate amount is commonly used in the industry. Well known to. The Lewis acid metal in the present invention can be variously selected as described above, but is preferably one selected from the group consisting of nickel, chromium and zinc. This polymer composition for a polymer temperature sensitive body is a nylon 12 composition having a uniform composition in which each additive material is mixed with nylon pellets in a mixer and then kneaded by a twin-screw extruder to well disperse the additive. The product is taken out in pellet form. As the polyamide used in the present invention, in addition to nylon 12 and nylon 11, copolymers such as N-alkyl substituted amides, ether amides and ester amides based on these nylon 12 and nylon 11 are suitable.

Next, a heat sensitive heater wire 6 as shown in FIG. 1 is constructed by using this polymer temperature sensitive body. As an example of the structure, as shown in the figure, an inner wound metal wire electrode 2, a polymer temperature sensing layer 3, an outer wound metal wire electrode 4, and an insulating jacket 5 are sequentially formed on a core thread 1. . Either the inner winding or the outer winding metal wire electrode is also used as a heater wire, and one wire fulfills both functions of a temperature sensor and a heater. For this metal wire electrode, a material is selected from its conductivity depending on the heater capacity, but for the metal wire electrode of the present invention, copper having a high conductivity is used as a core material, aluminum-coated copper wire, zinc-coated copper wire, nickel. In addition to coated copper wire such as coated copper wire, chrome coated copper wire, brass,
Materials such as Cu-Zn alloys are preferred. The coating of the surface of the metal wire electrode can be easily formed by a process such as plating. In particular, in the constitution of the present invention, zinc is used as the Lewis acid metal in the polymer temperature sensor, and the metal wire electrode to which a positive (anode component) electric field is applied in contact with the polymer temperature sensor is coated with zinc. When made of copper wire, nickel-coated copper wire, or brass, extremely high life performance can be obtained.

[Example 1] 0.5 parts by weight of phosphite type antioxidant tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite with respect to nylon 12 (100 parts by weight) and phenol type antioxidant (Irganox) 1010, manufactured by Ciba Geigy) 1.0
Phenol containing 12 parts by weight of heat-stable nylon and 5 parts by weight of nickel oxyiodide were mixed by a Hensyl mixer and kneaded by a twin-screw extruder to obtain a uniform dispersion of additives. The nylon 12 composition having various compositions was taken out in the form of pellets. This is 8 cm x 8
cm, 1 mm thick sheet, after hot pressing, acrylic resin silver paint was applied and the electrode was taken out, AC50V, 60Hz electric field was applied in the temperature range from room temperature to 120 ° C, and the impedance-temperature characteristic was measured. It was measured. 6
Impedance at 0 ℃ is 1 × 10 ⁹ Ω · cm, 40
The thermistor B constant in the temperature range of up to 100 ° C is 65
It was 00K.

Next, in order to construct a heat-sensitive heater wire using this polymer temperature sensor, an inner winding metal wire consisting of a ribbon copper wire is formed on a 1500 denier aromatic polyester core yarn 1 as shown in FIG. The electrode 2, the above-mentioned polymer temperature sensitive layer 3, the outer winding metal wire electrode 4 made of nickel-plated copper wire, and the insulating jacket 5 made of heat-resistant polyvinyl chloride are sequentially formed to form a heat-sensitive heater wire 6
Was configured. This heat-sensitive heater wire 6 is heated at 120 ° C. for 10
A heat resistance life test was conducted while applying a 0 V half-wave electric field (a positive electric field is applied to the electrode wire 4 side). As a result, after 1000 hours, the deviation from the initial temperature characteristics was 5 ° C. Was obtained. When this heat sensitive heater wire 6 is wired and adhered in the main body of the electric carpet and an outer winding metal wire electrode is used as a heating wire and connected to an electric control circuit to operate a one-wire type electric carpet, excellent temperature control can be performed. It was

[Example 2] 0.5 parts by weight of phosphite type antioxidant tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite and 12 parts of nylon 12 (100 parts by weight) and a phenol type antioxidant (Irganox) 1010, manufactured by Ciba Geigy) 1.0
Phenol containing 12 parts by weight of heat-stable nylon, 5 parts by weight of zinc iodide and 3 parts by weight of basic zinc oxybenzoate are mixed by a Hensyl mixer and kneaded by a twin-screw extruder. Then, a nylon 12 composition having a uniform composition in which the additives were well dispersed was taken out in the form of pellets. This was hot-pressed into a sheet having a size of 8 cm × 8 cm and a thickness of 1 mm, and then acrylic resin-based silver paint was applied to take out the electrode.
The impedance-temperature characteristic was measured at AC 50 V and 60 Hz in the temperature range of ° C. The impedance at 60 ° C. was 7 × 10 ⁸ Ω · cm, and the thermistor B constant in the temperature range of 40 to 100 ° C. was 7500K. next,
A thermal heater wire was constructed in the same manner as in Example 1 by using this polymer temperature sensitive body. A zinc-plated copper wire was used for the inner winding metal wire electrode 2 and the outer winding metal wire electrode 4. A heat-resistant life test was conducted on the heat-sensitive heater wire 6 at 120 ° C. while applying an electric field of 100 V half-wave, and after 1000 hours, an extremely excellent heat-resistant property with a deviation of 6 ° C. from the initial temperature property was obtained. .

[Example 3] Nylon 12 (100 parts by weight) and a modified nylon 12 (30 parts by weight) containing about 40 mol% of N-hexyl-substituted amide group in the repeating unit, relative to tris (2-ethylhexyl) Phosphate 0.
Heat containing 3 parts by weight and 0.3 parts by weight of triphenyl phosphite as a phosphite antioxidant and 0.5 parts by weight of a phenolic antioxidant (Irganox 1010, manufactured by Ciba Geigy). Stability Nylon 12 composition pellets, 3 parts by weight of zinc oxyiodide and 3 parts by weight of zinc iodide were mixed in a Hensyl mixer,
The mixture was kneaded with a twin-screw extruder, and taken out as pellets as a nylon 12-based composition having a uniform composition in which additives were well dispersed. This is 8 cm x 8 cm and 1 mm thick
After hot pressing into a sheet shape, the acrylic resin silver paint was applied, the electrode was taken out, and an electric field of AC50V, 60 Hz was applied in the temperature range from room temperature to 120 ° C. to measure its impedance-temperature characteristic. The impedance at 60 ° C. was 8 × 10 ⁸ Ω · cm, and the thermistor B constant was 7,000 K in the temperature range of 40 to 100 ° C. Next, a heat sensitive heater wire was constructed in the same manner as in Example 1 using this polymer temperature sensitive body. Inner winding metal wire electrode 2 and outer winding metal wire electrode 4
A galvanized copper wire was used for the. This heat sensitive heater wire 6
A heat resistance life test was performed at 20 ° C. while applying a 100 V half-wave electric field. As a result, after 1000 hours, an extremely excellent heat resistance characteristic of 5 ° C. from the initial temperature characteristic was obtained.

[0022]

As described above, according to the present invention, in addition to 1) excellent heat resistance, 2) a high thermistor B constant, and 3) no change due to direct current polarization over time, the excellent requirements are satisfied. It is possible to obtain a polymer thermocouple as a temperature sensor material. Further, by using the polyamide modified body together with nylon 12 as a polymer matrix, a polymer temperature sensitive body having improved low temperature characteristics can be obtained. Furthermore, according to the present invention, it is possible to obtain a heat-sensitive heater wire having improved heat resistant life characteristics.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a structure of a heat-sensitive heater wire using a polymer temperature sensor of the present invention.

[Explanation of symbols]

 1 Core Thread 2 Inner Wound Metal Wire Electrode 3 Polymer Thermosensitive Layer 4 Outer Wound Metal Wire Electrode 5 Insulation Jacket 6 Heat Sensitive Heater Wire

Claims (7)

[Claims] 1. A polymeric thermosensitizer comprising a oxyiodide of a Lewis acid metal in a polyamide composition. 2. A polyamide composition is a heat-stable nylon 12 composition containing a phosphite ester as an antioxidant, in which the Lewis acid metal oxyiodide and the same Lewis acid metal as the Lewis acid metal are contained. The polymer thermosensitizer according to claim 1, comprising a metal iodide. 3. A heat-stable nylon 12 composition containing a phosphite ester as an antioxidant, comprising a Lewis acid metal iodide and a basic metal salt of the same metal as the Lewis acid metal. Characteristic polymer temperature sensor. 4. The polymeric temperature-sensing body according to claim 3, wherein the basic metal salt is a basic organic metal salt of a Lewis acid metal ion and a carboxylic acid or an organic acid having a phenolic hydroxyl group. 5. The polymer temperature sensitive body according to claim 2, wherein the Lewis acid metal is one kind of metal selected from the group consisting of nickel, chromium and zinc. 6. A pair of metal wire electrodes, one of which serves also as a heater wire, and a polymer temperature-sensing layer interposed between the metal wire electrodes, wherein the polymer temperature-sensing layer is formed according to claim 2. Or a metal wire electrode on the side to which a positive electric field is applied, which is made of the polymer temperature sensor described in 4, and at least the surface of which is composed of the same metal element as the Lewis acid metal. 7. A metal wire electrode on the side to which a positive electric field is applied, wherein the Lewis acid metal in the polymer temperature sensor is zinc, and is a zinc-coated copper wire, a nickel-coated copper wire, or a brass wire. The polymer temperature sensor according to claim 6.