JPS60106101A - Polymer temperature sensor - 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 The present invention relates to a heat-sensitive material made of a specific polyamide resin composition, and particularly to a device for thermally controlling a capacitance component as one control factor. and materials with improved impedance behavior.

BACKGROUND ART The use of organic polymeric materials whose electrical properties change significantly depending on temperature, such as polyvinyl chloride and polyamide, as heat-sensitive elements has been known from the past, as seen in electric blankets, electric carpets, and the like. Control factors for the thermosensitive element include direct current volume resistivity, dielectric constant, and volume resistivity, and the control surface path can be operated by a combination of -0 or more of these. Therefore, the characteristics required of a thermosensitive element are: large changes in electrical properties due to temperature, small changes in electrical properties due to moisture absorption, and changes in electrical properties over time due to heat cycling. For example, it is stable and free of oxidation.

Until now, in order to meet this type of purpose, ion conductive substances such as surfactants have been added to the above organic polymer materials as additives (Japanese Patent Application Laid-Open No. 35-14179),
Copper halides, etc., which are ionically dissociable, were added (
Japanese Patent Publication No. 56-3904).

The main reason for the conductivity of these compositions is that they are naturally ionic substances, so when a DC electric field is applied, they cause polarization.
This causes a large change in impedance over time, and the former particularly has poor heat resistance, so it could not be used as a thermosensitive body as described below.

Therefore, as a result of intensive study and study to solve some of the above-mentioned practical problems, the present invention has developed a heat-sensitive material that satisfies the above-mentioned performance requirements by combining a specific polyamide resin and a specific additive. discovered that it could be made, and came up with the present invention,
Reached.

That is, in the present invention, 0.1 ferric chloride is added to a polyamide resin having 14 or less amide groups per 100 carbon atoms.
The present invention provides a heat-sensitive material comprising a polyamide composition containing 10 parts by weight of 1O.

According to the heat-sensitive element made of the heat-sensitive material of the present invention, the rate of change in electrical properties with respect to temperature is extremely large, and unlike surfactants, it may bleed out or deteriorate over time. Because there is no aluminum, its electrical properties are very stable, and there is a history of aluminum used for signal conductors.
It does not corrode metal wires or metal foils such as minilum, copper, etc., has excellent heat resistance, and has advantages such as easy kneading of polyamide resin and ferric chloride.

The polyamide resin used in the present invention is a polyamide with a low concentration of amide groups such as polyaminoundecamide (nylon 11) or polyω-laurolactam (nylon 12), and more specifically, a polyamide with a carbon atom number of io
It is a homopolyamide or copolyamide in which the number of amide groups per o is 14 or less.

The amount of ferric chloride, which is an additive component of the polyamide composition for heat-sensitive elements in the present invention, is 0.1 to 10.0.
Parts by weight, preferably 0.5 to 5.0 parts by weight. If it is less than 0.1 parts by weight, the change in electrical properties with respect to temperature is insufficient, and if it is more than 10.0 parts by weight, the polyamide This is not preferable because the mechanical properties of the resin deteriorate.

The method of adding ferric chloride to the polyamide resin is not particularly limited, and may be a method of adding it during the polyamide polymerization step, a method of mechanically mixing polyamide powder and ferric chloride, or a method of adding ferric chloride with polyamide pellets. Any method can be used, such as mixing iron and then melting and kneading it in an extruder.

The polyamide composition containing ferric chloride is usually further formed into a wire or sheet shape using an extruder or the like to form a heat-sensitive element.

The effects of the present invention will be explained below using examples.

Example 1 After tri-blending 1 part by weight of ferric chloride with 100 parts by weight of nylon 12 pellets (Diamid LI901J manufactured by Daicel Huls), they were melt-kneaded using an extruder and made into pellets using a pelletizer. The pellets were compressed to a thickness of approximately 0, % 220',
A 5 mm sheet was created. 100QHz of this sheet
The temperature dependence of the specific volume impedance was measured. The result is extremely ζζ, as shown by curve A in Figure 1.
A large gradient was obtained.

Example 2 After completely dissolving ferric chloride in water, nylon 6/12
Powder (“Diamid D170oJ” made by Teiselhuls)
') After mixing 5 parts by weight of ferric chloride to 100 parts by weight using a Henschel mixer, water was completely evaporated. A sheet with a thickness of about 0.5 mm was prepared by compression molding using this powdered Tr 220', and its volumetric impedance was measured in the same manner as in Example 1. The results are shown by curve B in Figure 1.

Like Example 1, it has a good temperature gradient.

Comparative Example 1 A sheet with a thickness of approximately 0.5 mm was made in the same manner as in Example 1 except that ferric chloride was not mixed (Nylon 12 pellets in Example 11). 1. When the temperature/impedance characteristics were investigated, it was found that the slope was gentler than that of the present invention, as shown by the curve Clζ in Figure 1. Comparative Example 2 In Example 1, nylon 6@12 belene ),
Exactly the same as Example 1 except that ferric chloride was not mixed.
When a sort with a thickness of approximately 0.5 mm was prepared in the same manner and the temperature/impedance characteristics were examined, it was found that the slope was similar to that of the 1-th curve, and the slope was gentler than that of the present invention.

As can be seen from these results, the temperature sensing element of the present invention has a significantly improved temperature detection function, that is, the rate of change in impedance with respect to temperature, compared to nylon 12 or nylon 6/12 alone. It has good electrical properties.

[Brief explanation of drawings]

The lEJ diagram is a graph showing the relationship between the volume-specific impedance and temperature of the polymer thermosensitive bodies obtained in Examples and Comparative Examples of the present invention. Patent applicant Tyssel-Hüls Co., Ltd. 20 40
60 80 100 120 140 Temperature (℃)

Claims (1)

[Claims] A polymer thermosensitive body made of a polyamide composition containing 0.1 to 10.0 parts by weight of a polyamide resin Cζferric chloride having 14 or less amide groups per 100 carbon atoms.