JPS6084358A - High-molecular temperature sensor - Google Patents

Abstract

PURPOSE:To provide a high-molecular temperature sensor which exhibits a high rate of change in electrical properties with temperature and has excellent heat resistance and long-term stability of electrical properties, by blending potassium thiocyanide with a polyamide resin having a low amide group concn. in a specified wt. ratio. CONSTITUTION:0.1-10pts.wt. potassium thiocyanide is blended with a polyamide resin (e.g. nylon 11 or nylon 12) contg. 14 or less amide groups per 100 carbon atoms to obtain the desired high-molecular temperature sensor. The resulting sensor exhibits a high rate of change in volume intrinsic impedance with temperature, has excellent temperature detecting performance, causes neigher bleedout nor deterioration, does not corrode metals such as aluminum and copper used as signal conductors and is suitable for use as a temperature sensor for heat-sensitive heater, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to heat-sensitive heat-sensitive resin compositions made of a specific polyamide resin composition, particularly heat-sensitive resin compositions in a device that uses heat regulation as a control factor for all electrotherapeutic components. 4j' (if,+), the behavior of the innovitanos is improved with respect to the temperature of t1.

Traditionally, organic polymers with high electrical resistance depending on temperature, such as polyvinyl chloride, polyamide, etc., are used as heat-sensitive elements in electric blankets.

Electric carpets, etc. are well-known examples.

The control factors for heat-sensitive elements include DC volume resistivity,
dielectric constant and volume-specific inopedanos, and a combination of one or more of these can be used to operate the control circuit.

Therefore, the characteristics required of a heat-sensitive element are that the rate of change in electrical properties due to temperature is large, and the change in electrical properties due to moisture absorption is small.

One of the advantages is that the electrical properties do not change over time due to heat cycles and are stable.

Until now, in order to make a J-type suitable for this type of purpose, ionoconductive substances such as a surface active phase were added to the organic polymer moon phase as an additive (Japanese Patent Application Laid-Open No. 14179/1982).
Ion-dissociating substances such as copper chloride/copper chloride were added. (Japanese Patent Application Laid-Open No. 56-3904) However, since the conductive carrier of these compositions is naturally an ionotropic substance, when a DC electric field is applied, it causes a considerable amount of trouble, and the large diameter of Inopitanos is 11. In particular, the former was inferior in terms of heat control and could not be used as a temperature sensor in a thermal heater as described below.

Therefore, as a result of intensive studies to solve some of the above-mentioned practical problems, the present invention has been developed to create a heat-sensitive material that satisfies the above-mentioned required performance by introducing a specific polyamide resin and a specific additive. The present invention was achieved by discovering that it is possible to produce the following.

That is, the present invention provides a heat-sensitive material comprising a polyamide composition containing 01 to 00 parts by weight of potassium thiocyanide to a polyamide resin having 14 or less amide groups per 100 carbon atoms.

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 does not bleed out or deteriorate over time. It has excellent electrical stability and does not corrode metals (wires or foils) such as aluminum and copper used for signal conductors.

1111 has excellent thermal properties and has advantages such as easy kneading of sized polyamide resin and potassium thionanide.

In the present invention, the polyamide resin to be used is a polyamide with a low concentration of amide groups, such as polyaminounotecamide (nylon II) or polyω-laurolactam (naio/J2), and more specifically, carbon atoms. Number 1
It is a homopolyamide or copolyamide in which the number of amide groups per 00 is 14 or less.

It is an additive component of the polyamide composition for heat-sensitive elements in the present invention. The amount of potassium thiocyanide added is 01 to 10.0 parts by weight, preferably 0 to the polyamide resin.
5 to 50 parts by weight is appropriate; if it is less than 1 part by weight, the electrical properties will not change sufficiently with temperature, and if it is more than 100 parts by weight, the mechanical properties of the polyamide resin will deteriorate. It's not right.

Addition of potassium thione anodide to polynomide resin
How to do it! The agency has not determined the importance of small rear εj.
Any method can be used, such as adding it in stages, mechanically mixing the polyamide powder and potassium thiocyanide heptaide, or mixing it with the polyamide pellet and then mixing it with molten fMf in an extruder.

The polyamide composite containing potassium thiocyanide is usually further formed into a wire or sort shape using an extruder or the like to produce a heat-sensitive element.

The present invention will be explained in detail below.

Example 12 pellets of non-nylon (Diamid L 1901, manufactured by Daicel-Hüls) 100 parts by weight (1 part by weight of potassium thiocyanide) were dry-blended and then melt-kneaded using an extruder. The pellets were pelletized using a pelletizer (z 220') to create a sheet with a thickness of about 0.5 mm by compression molding.The temperature dependence of the volume specific impedance of this sheet at 1000 Hz K was measured. A very large distribution was obtained, as shown by curve A in the figure.

Example 2 After completely dissolving potassium thiocyanide in water, nylon 6.12 powder (Teiselhüls H Diamide D
J700) I (10 parts by weight and 5 parts by weight of potassium thiocyanate were mixed in a 7-well mixer, and the water was completely evaporated. This powder was compression molded at 220° to a thickness of Q, A 5mm sheet was prepared and Example 1
The result of measuring the characteristic impedance in the same manner as above is shown by curve 13 in Figure 1, where j''<t. Like Example 1, it has good temperature distribution.

Comparative Example] A sheet with a thickness of approximately 0.5 nm was prepared in exactly the same manner as in Example 1, except that potassium thiocyanate was not mixed into the nylon 12 pellets, and the temperature Inopedanos characteristics were investigated. As shown by curve C in Figure 1, it can be seen that the distribution is looser than in the present invention.

Comparative Example 2 In Example 1 VC, using Nylo 7G, 12 pellets, potassium thiocyanide k? 7-1 with a thickness of about 0.5 mm in exactly the same manner as in Example 1 except that m people were not used.
・ was made and the temperature-inopitance characteristics were investigated.
As shown in the curved line in FIG. 1, it can be seen that the distribution is gentler than in the present invention.

As can be seen from these results, the feeling of the present invention is +71□1
Compared to those made of Nylon 1j7J2 or Nylon 6.1211, the body has a much improved temperature sensing function, that is, the rate of change with respect to temperature, and has excellent electrical properties.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between volume-specific i/pedanos and temperature of polymer thermosensitive bodies obtained in Examples and Comparative Examples of the present invention. Patent applicant Daicel-Hüls filed for IS-type company procedure
Amendment (spontaneous) November 31, 1985] Patent Application No. 192506 of 1988 2 Name of the invention Polymer thermosensitive body 3 Relationship with the person making the amendment Case Patent applicant 5 Subject of the amendment For the specification “Detailed Description of the Invention” Box 1
6. Contents of the amendment (1) The statement “It is a component” on page 4, line 7 of the specification was changed to “
"It's an ingredient," he corrected. (2) Specification 1, page 5, line 17, page 6, line 131] and page 6, line 20 [Nylon 6.12j description 11. (Corrected to [nylon 6/12J.

Claims (1)

[Claims] Potassium thiocyanide is added to a polyamide resin having 14 or less amide groups per 100 carbon atoms.
4. Polymer temperature sensitive body made of a polyamide composition blended in parts by weight.