JPH04192501A - Polymer temperature-sensitive material - Google Patents

Abstract

PURPOSE:To obtain good thermistor characteristics at high temperature by employing a trimellitate and a triester orthophosphate as a plasticizing agent and by mixing the trimellitate and the triester orthophosphate at a ratio of 5:1 to 2:3. CONSTITUTION:A temperature-sensitive electric wire, which uses a temperature- sensitive polymer as a temperature-sensitive layer, is fabricated by the steps of: wrapping around a core 11 with a primary conductor 12; super-posing a temperature-sensitive layer 13 on the primary conductor 12; covering the temperature-sensitive layer 13 with a secondary conductor 14; and superimposing a shield layer 15 and a PVC sheath 16, in order, on the secondary conductor. The temperature-sensitive polymer of the temperature-sensitive layer 13 comprises a trimellitate and a triester orthophosphate as a plasticizing agent, wherein the trimellitate and the triester orthophosphate are mixed in a proportion of 5:1 to 2:3. With this composition, the temperature-sensitive polymer can be improved in thermistor characteristics at high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polymer temperature-sensitive material, and particularly to a polymer temperature-sensitive material used in a temperature-sensitive layer of a temperature-sensitive wire such as an electric blanket or an electric carpet.

[Prior Art] Polyamide-based polymer temperature-sensitive materials and polyvinyl chloride-based polymer temperature-sensitive materials have conventionally been used in the temperature-sensitive layer of temperature-sensitive lines of electric blankets, electric carpets, etc. There's some wood.

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

Polyvinyl chloride-based polymer temperature-sensitive materials are made by adding a plasticizer, a heat stabilizer, and an ion-conductive substance to polyvinyl chloride, which is a base polymer with low moisture absorption. usually,
As the plasticizer, phthalic acid dialkyl ester or trimeric acid trialkyl ester is used. The ion conductive substance is added to impart thermistor properties to the composition, and antistatic agents and the like are used. In this way, polyvinyl chloride-based polymer temperature-sensitive materials have low hygroscopic properties due to the base polymer polyvinyl chloride, and relatively high thermistor properties due to the ion conductive material, so they are able to quickly warm up quickly and have subtle It is suitable as a temperature-sensitive layer material for temperature-sensitive wires such as electric carpets that require temperature control.

[Problem to be solved by the invention] In recent years, electric carpets have become larger and are required to quickly heat large areas.

For this reason, the temperature-sensitive line also becomes quite high, and there is a risk of local overheating. Therefore, it has been desired to develop a polymer temperature-sensitive material that exhibits high thermistor properties in high-temperature areas.

Therefore, it may be possible to increase the amount of ion conductive substance added to polyvinyl chloride, since the ion conductivity of polyvinyl chloride polymer temperature-sensitive materials at high temperatures depends on the viscosity of the plasticizer added. Even if a large amount of an ion conductive substance is added, the ion conductivity will be saturated to a certain extent.

Therefore, when a large amount of ion conductive material is added to polyvinyl chloride, the absolute value of impedance becomes small, but the thermistor characteristics do not become very high. Also, if the type of phthalate or trimellitate ester, which is a plasticizer that affects the ionic conductivity of polyvinyl chloride polymer temperature-sensitive materials at high temperatures, is changed, the absolute value of impedance will decrease or the thermistor characteristics It doesn't get expensive.

The present invention has been made in view of these points, and an object of the present invention is to provide a polymer temperature-sensitive material that exhibits excellent thermistor properties and heat resistance at high temperatures.

[Means for Solving the Problems] The present invention provides 40 to 80 parts by weight of a plasticizer, 0.1 to 10 parts by weight of an ion conductive additive, and 0.5 parts by weight of a thermal stabilizer to 100 parts by weight of polyvinyl chloride. ~10 parts by weight of the polymer temperature-sensitive material, wherein the plasticizer consists of trimellitic acid ester and orthophosphoric triester, and
Provided is a polymer temperature-sensitive material characterized in that the blending ratio of trimellitic acid ester: orthophosphoric acid triester is 5:1 to 2.3.

Here, as the trimellitic acid ester used as a plasticizer, trimellitic acid alkyl esters such as trimellitic acid octyl ester and trimellitic acid n-octyl ester are used.

As the orthophosphoric acid triester used as a plasticizer, triphenyl phosphate, tricresyl phosphate, triethylphenyl phosphate, tripropylphenyl phosphate, tricylenyl phosphate, etc. are used. Tri-xylenyl phosphate is preferred because it has excellent heat resistance, and tri-2,4-xylenyl phosphate is particularly preferred because it is liquid at room temperature and is easy to handle.

The blending ratio of trimellitic acid ester: orthophosphoric acid triester is set to be 5:1 to 2:3. this is,
If the amount of orthophosphoric triester is greater than this ratio, the heat resistance of the resulting polymer temperature-sensitive material will decrease; if the amount of orthophosphoric triester is less than this ratio, the temperature-sensitive polymer material obtained will be This is because the thermistor properties of the material at high temperatures deteriorate. Particularly preferred trimellitic acid esters:
The ratio of orthophosphoric acid triester is 4:1 to 1:1.

Anionic surfactants, cationic surfactants, and nonionic surfactants can be used as the ion conductive additives to be added to polyvinyl chloride. Among these, when considering heat resistance and thermistor characteristics, the fourth
Most preferred are perchlorate compounds of the ammonium salts.

As the heat stabilizer to be added to 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 4
The amount is set at 0 to 80 parts by weight. This is because if the amount of plasticizer added is less than 40 parts by weight, the composition will become hard and have poor moldability, and if the amount of plasticizer added exceeds 80 parts by weight, the composition will become too soft. This is because the mechanical strength of a molded article obtained by molding this composition is reduced.

The amount of the ion conductive additive added to 100 parts by weight of polyvinyl chloride is set to 0.1 to 10 parts by weight. This is because when the amount of the ion conductive additive is less than 0.1 parts by weight, the thermistor properties of the obtained polymer temperature-sensitive material are not exhibited.
This is because even if the amount of the ion-conductive additive exceeds 10 parts by weight, higher thermistor characteristics cannot be obtained and the economical efficiency becomes worse.

The amount of heat stabilizer added to 100 parts by weight of polyvinyl chloride is set at 0.5 to 10 parts by weight. This is because if the blending amount of the heat stabilizer is less than 0.5 parts by weight, thermal stability will not be achieved, and even if the blending amount of the heat stabilizer exceeds 10 parts by weight, higher thermal stability will not be obtained. This is because the economy becomes worse.

[Function] The polymer temperature-sensitive material of the present invention is composed of a trimellitic acid ester and an orthophosphoric triester as a plasticizer, and the blending ratio of trimellitic acid ester: orthophosphoric triester is 5:1 or more. A ratio of 2:3 is used.

Orthophosphoric acid triester has a higher viscosity than phthalate and trimellitic acid ester, which have been conventionally used as plasticizers in polymer temperature-sensitive materials, perhaps due to the temperature dependence of its viscosity. For this reason,
At low temperatures, the viscosity is high, reducing ionic conductivity, and at high temperatures, the viscosity is low, increasing ionic conductivity. Therefore, the thermistor properties of the polymer temperature-sensitive material at high temperatures can be improved.

[Embodiments] Hereinafter, embodiments of the present invention will be specifically described 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 a temperature-sensitive electric wire of Example 1.

Polyvinyl chloride (manufactured by Nippon Zeon Co., Ltd., trade name 101EP) is used as the polymer temperature-sensitive material of the temperature-sensitive layer 13, and trimellitic acid n- is used as a plasticizer based on 100 parts by weight of polyvinyl chloride.
50 parts by weight of a mixture with octyl ester and tri-2,4-xylenyl phosphate (trimellitate, orthophosphoric acid triester-1:1), 0.5 parts by weight of pensalkonium perchlorate as an ion conductive additive weight part,
In addition, as a heat stabilizer, a combination of 1 part by weight of dibasic lead stearate and 5 parts by weight of tribasic lead stearate was used.

Moreover, the shielding layer 15 is for preventing the transfer of plasticizer between the temperature-sensitive layer 13 and the PVC sheath 16, and is made of PE.
It is formed by winding a T (polyethylene terephthalate) film.

The thermistor characteristics and impedance change rate of the obtained temperature-sensitive wire of Example 1, and the heat resistance of the polymer temperature-sensitive material of the temperature-sensitive layer were investigated. The results are shown in Table 1 below. Note that the thermistor characteristics were measured using 60 Hz impedance characteristics, and evaluated using the thermistor B constant calculated therefrom. The impedance change rate was determined by comparison from the initial value.

Example 2 The plasticizer blended into the polymer temperature-sensitive material of the temperature-sensitive layer 13 was a mixture of trimellitic acid n-octyl ester and tricresyl phosphate (trimellitic acid ester: Orthophosphoric acid triester
A thermosensitive electric wire of Example 2 was produced in the same manner as in Example 1 except that the amount was 50 parts by weight (4:1).

The thermistor characteristics and impedance change rate of the obtained temperature-sensitive wire of Example 2 were investigated in the same manner as in Example 1. The results are also listed in Table 1 below.

Comparative Example 1 Same as Example 1 except that the plasticizer blended into the polymer temperature-sensitive material of the temperature-sensitive layer 13 was 50 parts by weight of trimellitic acid n-octyl ester based on 100 parts by weight of polyvinyl chloride. A thermosensitive electric wire of Comparative Example 1 was produced in the same manner.

The thermistor characteristics and impedance change rate of the obtained temperature-sensitive wire of Comparative Example 1 were investigated in the same manner as in Example 1. The results are also listed in Table 1 below.

Comparative Example 2 The plasticizer blended into the polymer temperature-sensitive material of the temperature-sensitive layer 13 was a mixture of trimellitic acid n-octyl ester and tricresyl phosphate (trimellitic acid ester: Orthophosphoric acid triester
A thermosensitive electric wire of Comparative Example 2 was produced in the same manner as in Example 1 except that the ratio was 50 parts by weight (1:4).

The thermistor characteristics and impedance change rate of the obtained temperature-sensitive electric wire of Comparative Example 2 were investigated in the same manner as in Example 1. The results are also listed in Table 1 below.

Table 1 As is clear from Table 1, the temperature-sensitive electric wire (Example 1゜2) using the polymer temperature-sensitive material of the present invention as the temperature-sensitive layer has good thermistor characteristics at high temperatures and a low impedance change rate. was low. Moreover, the polymer temperature-sensitive material used as the temperature-sensitive layer had excellent heat resistance.

On the other hand, a thermosensitive wire (Comparative Example 1) in which only trimellitic acid n-octyl ester was blended as a plasticizer and a polymeric thermosensitive material was used as a thermosensitive layer (Comparative Example 1) had poor thermistor characteristics at high temperatures. In addition, outside the scope of the present invention, a thermosensitive wire (Comparative Example 2) using a polymeric thermosensitive material as a thermosensitive layer using a mixture of trimellitic acid ester and orthophosphoric acid triester as a plasticizer (Comparative Example 2) The impedance residual ratio was high and the characteristics were severely degraded.

[Effects of the Invention] As explained above, the polymer temperature-sensitive material of the present invention can exhibit excellent thermistor characteristics and heat resistance at high temperatures. Therefore, the temperature-sensitive electric wire using the polymer temperature-sensitive material of the present invention in the temperature-sensitive layer can sufficiently prevent local overheating and can stably control temperature over a long period of time.

[Brief explanation of the drawing]

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. DESCRIPTION OF SYMBOLS 1... Temperature-sensitive electric wire, 11... Core wire, 12... -Secondary conductor, 13... Temperature-sensitive layer, 14... Secondary conductor, 15...
- Shielding layer, 16...PVC sheath. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] 40 to 80 parts of plasticizer per 100 parts by weight of polyvinyl chloride
parts by weight, 0.1 to 10 parts by weight of an ion conductive additive, and 0.5 to 10 parts by weight of a thermal stabilizer, wherein the plasticizer is trimellitic acid ester and orthophosphorus. It consists of an acid triester, and the blending ratio of trimellitic acid ester: orthophosphoric acid triester is 5:
A polymer temperature-sensitive material characterized by a ratio of 1 to 2:3.