JPH04319633A - Macromolecualr temperature-sensitive material - Google Patents

Abstract

PURPOSE:To obtain an excellent thermistor characteristic not only in a low temperature area, but also in a high temperature area, by adding polyvinyl carbazole to a composition of a macromolecular temperature-sensitive material constituted of polyvinyl chloride, a plasticizer, an ion-conductive additive and a thermal stabilizer. CONSTITUTION:Polyvinyl carbazole is added to a composition of a macromolecular temperature-sensitive material constituted of polyvinyl chloride, a plasticizer, an ion-conductive additive and a thermal stabilizer. As to the plasticizer, phthalate ester can be used. As to the ion-conductive additive, an anion surfactant can be used. As for the thermal stabilizer, dibasic lead stearateor the like is used. A primary conductor 12 is wound round on a core wire 11, a temperature-sensitive layer 13 is formed on the conductor 12, a secondary conductor 14 is wound round on the temperature-sensitive layer 13, a shielding layer 15 and a PVC sheath 16 are formed thereon sequentially and thereby a temperature-sensitive electric wire is obtained. This temperature- sensitive electric wire is excellent in a thermistor characteristic not only in a low temperature area, but also in a high temperature area, a change rate of impedance thereof is low and it is excellent in heat resistance.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to polymer temperature-sensitive materials.
In particular, the present invention relates to polymer temperature-sensitive materials used in temperature-sensitive layers of temperature-sensitive electric wires for electric blankets, electric carpets, etc.

0002

2. Description of the Related Art Polyamide-based and polyvinyl chloride-based polymer temperature-sensitive materials have conventionally been used as temperature-sensitive layers of temperature-sensitive electric wires for electric blankets, electric carpets, and the like. Polyamide-based polymeric temperature-sensitive materials have relatively high hygroscopicity and low thermistor properties, so they are unsuitable for applications that require rapid heating, such as electric carpets. For this reason, polyvinyl chloride-based polymer temperature-sensitive materials are mainly used in the temperature-sensitive layers of temperature-sensitive electric wires for electric carpets and the like.

In conventional polyvinyl chloride-based polymer temperature-sensitive materials, a plasticizer, a thermal stabilizer, and an ion-conductive substance are added to polyvinyl chloride, which is a base polymer with low moisture absorption. Usually, phthalic acid dialkyl ester or trimellitic acid trialkyl ester is used as a plasticizer. In addition, ion conductive substances are added to impart thermistor properties to the composition, and antistatic agents are usually used as ion conductive substances, and quaternary amines are known to be particularly effective. ing. In this way, polyvinyl chloride-based polymer temperature-sensitive materials have low hygroscopicity due to the polyvinyl chloride used as the base polymer, and relatively high thermistor properties due to the ion-conductive material. It has been used as a suitable temperature-sensitive layer material for temperature-sensitive electric wires for electric carpets, etc., which require high temperature control and delicate temperature control properties.

0004

[Problem to be solved by the invention] However, in recent years,
As electric carpets, etc. become larger and require rapid heating of large areas, there is a demand for polymer temperature-sensitive materials that have high thermistor characteristics in high temperature ranges in addition to conventional high thermistor characteristics in low temperature ranges. has been done. Because of the need to quickly heat a large area, the temperature-sensitive wire used becomes quite high temperature, and conventional temperature-sensitive wires using polymer temperature-sensitive materials, which have high thermistor properties in relatively low-temperature regions, cannot be used. This is because there is a risk of local overheating, and a temperature-sensitive layer with high thermistor characteristics is required even in a high-temperature region. Therefore, attempts have been made to increase the amount of ion conductive material added to polyvinyl chloride. However, although the absolute value of impedance became smaller, the thermistor characteristics did not become much higher. The ionic conductivity of polyvinyl chloride polymer thermosensitive materials at high temperatures depends on the viscosity of the added plasticizer, so even if a large amount of ion conductive material is added, the ionic conductivity will be saturated to a certain extent. I ended up
This is because the ionic conductivity does not increase any further. In addition, focusing on the fact that plasticizers affect the ionic conductivity of polyvinyl chloride polymer temperature-sensitive materials at high temperatures as mentioned above, we selected the type of phthalate or trimellitate ester to be used as a plasticizer. Attempts were made to change this, but although the absolute value of impedance decreased, the thermistor characteristics did not improve. The present invention has been made in view of these points, and an object of the present invention is to provide a polymeric temperature-sensitive material that exhibits excellent thermistor characteristics not only in a low-temperature region but also in a high-temperature region.

[0005]

[Means for Solving the Problems] As a result of research, the present inventor focused on polyvinylcarbasol, which forms a charge transfer complex, and developed a polymer consisting of polyvinyl chloride, a plasticizer, an ion conductive additive, and a thermal stabilizer. The above object has been achieved by the polymer temperature-sensitive material of the present invention, which is characterized by adding polyvinylcarbazole to a temperature-sensitive material composition.

[0006] As the plasticizer to be added to the polyvinyl chloride, any of phthalic acid esters, trimellitic acid esters, polyester polymeric plasticizers, etc. can be used. For applications requiring heat resistance, such as temperature-sensitive materials for electric carpets, it is preferable to use materials with low volatility. Anionic surfactants, cationic surfactants, and nonionic surfactants can be used as the ion conductive additives to be added to polyvinyl chloride. In consideration of heat resistance and thermistor properties, perchlorate compounds or bromide salt compounds of quaternary ammonium salts are most preferred. As the heat stabilizer to be mixed with polyvinyl chloride, dibasic lead stearate, tribasic lead stearate, etc. are used. The amount of plasticizer added to 100 parts by weight of polyvinyl chloride is 30 to 80 parts by weight, the amount of ion conductive additive is 0.1 to 10 parts by weight, the amount of heat stabilizer is 0.5 to 20 parts by weight, The amount of polyvinylcarbazole is preferably 0.5 to 10 parts by weight. Incidentally, the polymeric temperature-sensitive material according to the present invention can be manufactured by a method similar to the manufacturing method of conventional polyvinyl chloride-based polymeric temperature-sensitive materials.

[0007]

[Function] In the polymer temperature-sensitive material according to the present invention, the movement of molecular chains becomes active by blending polyvinyl carbazole to mediate the movement of charged bodies and activate ionic conduction, which is the main body of electrical conduction. It is thought that this lowers the impedance at high temperatures and, as a result, improves the thermistor characteristics in the high temperature range. Carbazole monomers are also thought to provide electronic conduction, but carbazole monomers have sublimation properties, so they are not suitable for long-term use at high temperatures. Further, polyvinylcarbazole has the advantage that its main chain has good compatibility with polyvinyl chloride, and there is no problem such as leaching over time.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Example 1 FIG. 1 is a schematic explanatory diagram of a temperature-sensitive electric wire using the polymer temperature-sensitive material of the present invention as a temperature-sensitive layer. First, place the primary conductor 1 on the core wire 11.
2, then a temperature-sensitive layer 13 is formed on the primary conductor 12, and then a secondary conductor 14 is wound on the temperature-sensitive layer 13,
A shielding layer 15 and a PVC sheath 16 were sequentially formed on the secondary conductor to produce the temperature-sensitive wire of Example 1. Temperature sensitive layer 13
Polyvinyl chloride (manufactured by Nippon Zeon Co., Ltd., trade name 101EP) was added to 100 parts by weight of polyvinyl chloride, and trimellitic acid n-octyl ester (manufactured by Kao Corporation, trade name Trimex N-08)
50 parts by weight, 0.5 parts by weight of stearyldimethylbenzyl perchlorate as an ion conductive additive, 10 parts by weight of white lead as a heat stabilizer, 1 part by weight of DBL and 2 parts by weight of polyvinylcarbazole. The polymer temperature-sensitive material of Example 1 was used. In addition, the shielding layer 1
5 is for preventing migration of plasticizer between the temperature sensitive layer 13 and the PVC sheath 16, and is formed by wrapping a PET (polyethylene terephthalate) film. The thermistor characteristics and heat resistance of the temperature-sensitive electric wire produced as described above using the polymer temperature-sensitive material of Example 1 according to the present invention as a temperature-sensitive layer were investigated. The results are shown in Table 1 below. In addition, the thermistor characteristics are 60H
It was measured using the z-impedance characteristic, and evaluated using the thermistor B constant calculated from the z-impedance characteristic. Heat resistance was determined by comparing the initial value of impedance.

Example 2 The blending ratio of polyvinyl carbazole was changed to that of polyvinyl chloride.
A polymer temperature-sensitive material of Example 2 according to the present invention was prepared in the same manner as the polymer temperature-sensitive material of Example 1 except that 10 parts by weight was added to 100 parts by weight. A temperature-sensitive electric wire was produced in the same manner as the temperature-sensitive electric wire produced using the polymer temperature-sensitive material of Example 1 for the temperature-sensitive layer 13, using a thermal material for the temperature-sensitive layer 13. The thermistor characteristics and heat resistance of the obtained temperature-sensitive wire using the polymer temperature-sensitive material of Example 2 were investigated in the same manner as the temperature-sensitive wire using the polymer temperature-sensitive material of Example 1. The results are also listed in Table 1 below.

Comparative Example 1 A polymer temperature-sensitive material of Comparative Example 1 was prepared in the same manner as the polymer temperature-sensitive material of Example 1 except that polyvinylcarbazole was not blended. A temperature-sensitive electric wire was produced in the same manner as the temperature-sensitive electric wire produced using the polymeric temperature-sensitive material of Example 1, using a thermal material for the temperature-sensitive layer 13. The thermistor characteristics and heat resistance of the obtained temperature-sensitive wire using the polymer temperature-sensitive material of Comparative Example 1 were investigated in the same manner as the temperature-sensitive wire using the polymer temperature-sensitive material of Example 1. The results are also listed in Table 1 below.

Comparative Example 2 Instead of blending polyvinylcarbazole, the blending ratio of stearyldimethylbenzyl perchlorate blended as an ion conductive additive was increased to produce polyvinyl chloride.
A polymer temperature-sensitive material of Comparative Example 2 was prepared in the same manner as the polymer temperature-sensitive material of Example 1 except that 3 parts by weight of stearyldimethylbenzyl perchlorate was blended with respect to 100 parts by weight, and the comparative example A thermosensitive electric wire was produced using the polymeric thermosensitive material of Example 2 for the thermosensitive layer 13 in the same manner as the thermosensitive electrical wire produced using the polymeric thermosensitive material of Example 1 for the thermosensitive layer 13. . The thermistor characteristics and heat resistance of the obtained temperature-sensitive wire using the polymer temperature-sensitive material of Comparative Example 2 were investigated in the same manner as the temperature-sensitive wire using the polymer temperature-sensitive material of Example 1. The results are also listed in Table 1 below.

[0012] Table 1

As is clear from Table 1, temperature-sensitive electric wires (Examples 1 and 2) using the polymer temperature-sensitive material of the present invention as a temperature-sensitive layer
not only had high thermistor characteristics in the low temperature range, but also had good thermistor characteristics at high temperatures, had a relatively low impedance change rate, and had excellent heat resistance. On the other hand, the temperature-sensitive electric wire (Comparative Example 1) using a polymer temperature-sensitive material without polyvinylcarbazole as the temperature-sensitive layer,
Thermistor characteristics at high temperatures were poor. In addition, a thermosensitive wire (Comparative Example 2) in which a polymer thermosensitive material with an increased amount of ion conductive additive was used as the thermosensitive layer instead of blending polyvinylcarbazole had high thermistor characteristics at low temperatures, but The thermistor characteristics at high temperatures were not improved; on the contrary, the rate of change in impedance was large, and the characteristics were severely degraded.

[0014]

As explained above, the present invention provides excellent thermistor properties and good properties not only in low temperature ranges but also in high temperature ranges by blending polyvinyl carbazole into a polyvinyl chloride polymer temperature-sensitive material composition. Achieving a thermosensitive polymer material that exhibits heat resistance. The polymer temperature-sensitive material according to the present invention can be used in electric heating devices that require complete prevention of local overheating and stable temperature control over a long period of time, particularly for temperature-sensitive electric wires used in electric carpets and the like. It is ideal for temperature-sensitive layers and contributes to improving the safety of these electric heating devices.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a temperature-sensitive electric wire using the polymer temperature-sensitive material of the present invention in a temperature-sensitive layer.

[Explanation of symbols]

1 Temperature-sensitive wire 11 Core wire 12 Primary conductor 13 Temperature sensitive layer 14 Secondary conductor 15 Shielding layer 16 PVC sheath

Claims (1)

[Claims] 1. A polymer temperature-sensitive material comprising a polymer temperature-sensitive material composition comprising polyvinyl chloride, a plasticizer, an ion conductive additive, and a heat stabilizer, and a polyvinyl carbazole added thereto.