JPS612302A - 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 Field of Industrial Application The present invention relates to a polymer thermosensitive body used in temperature sensors such as electric heating devices, flexible thermosensitive heater wires, and the like.

2. Description of the Related Art Conventional Structure and Problems Conventionally, a polymer temperature sensitive body has generally been disposed between a pair of wire-wound electrodes and used as a flexible temperature sensing wire or heat sensitive heater wire. A specific polyamide composition is used as the material for this polymer temperature sensitive body, and its capacitance, resistance,
It functions as a temperature sensor by utilizing changes in impedance due to temperature.

This type of polymer thermosensitive material is required to have the following performance.

(1) Good temperature detection sensitivity.

(2) It has a sharp melting point and functions as a temperature fuse.

(3) Impedance should not change over time due to ion polarization in the DC component electric field.

(4) Not easily affected by humidity.

The polymer temperature sensitive body mainly composed of polyamide is the one described in (1) above.
, (2) can be imparted relatively easily, and there are many known examples. Regarding (3), in addition to the performance of the polymer window heating body itself, such as the stabilizer composition of the polyamide composition, the type of additives, and the molecular weight, there are also factors other than the material, such as the configuration of the thermal heater wire and the applied electric field conditions. It is also greatly affected. (
The influence of humidity in 4) depends on the characteristics of the polymer thermosensitive material itself, and even nylon 11 and nylon 12, which have low hygroscopicity among polyamide resins, can have a large effect on humidity, such as -117. It is disclosed that a composition of a polyamide resin and a phenolic compound has a large effect.

On the other hand, examples using polyesteramide as the polyamide resin include JP-A-57-206001 and JP-A-58-
136624, and examples using polyether ester amide are disclosed in JP-A-55-145756 and JP-A-55-1.
No. 45757, etc. However, these resins having ester groups such as polyester amide or polyether ester amide have poor hydrolysis resistance and hot water resistance.

Alternatively, in order to fulfill the temperature fuse function as the performance required of the polymer thermosensitive material mentioned above, it is impossible to reduce the amide group concentration by reducing the amide group concentration, so it is difficult to obtain a large moisture resistance effect. There was a problem.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a polymer thermosensitive material whose characteristics vary little due to humidity.

Components of the Invention The present invention provides a polymer comprising an aldehyde condensation polymer of a phenolic compound added to a polymer matrix containing a polyetheramide having undecaneamide units and dodecanamide units. It is a temperature sensitive body.

It has been found that, unlike conventional compositions of nylon 11 or nylon 12 and phenolic compounds, the polymer thermosensitive material of the present invention has a remarkable effect on reducing property fluctuations due to humidity.

The typical structure of the polyether amide in the present invention is:
The block copolymer represented by the following formula has the effects of the present invention even if it contains an ether component in a random or grafted form.

R2: Alkylene group having 2 to 6 carbon atoms) Description of Examples Polyundecaneamide, polydodecanamide, polyesteramide, and polyetheramide were selected as the polymer matrix, and p-oxybenzoic acid nonyl ester and p-oxybenzoic acid nonyl ester were selected as the phenolic compound. -nonylphenol and p-chlorophenol were used. Furthermore, these phenolic compounds were used after being polycondensed with formaldehyde. Polymer window warm body samples using these materials are made by blending a phenolic material into a polymer matrix, kneading it into pellets using an extruder, and then heating it to a size of approximately 1° (yg
A 1rMl thick sheet was formed from 10 cTn, and silver paint electrodes were provided on both sides of the sheet. Also, moisture resistance (61w)
was evaluated as the temperature difference in the thermistor characteristics when the sample was dried and when it was soaked in moisture at a relative humidity of 87%.

Composition and moisture resistance △TW of these polymer temperature sensitive bodies.

Thermistor B constant BZ is shown in the table. However, BZ is 3o℃
This is the thermistor B constant determined from the impedance at 60°C.

As shown in Conventional Examples 1 and 2 in the table below, it is known that the moisture-resistant effect of the phenolic material on the margin polyamide resin is lower than that of the aldehyde condensation polymer compared to the effect of the phenolic compound.

However, it can be seen that the moisture resistance behavior of the examples differs from those of the conventional examples, and a new and excellent moisture resistance effect is achieved.

This can be considered as follows. That is, since polyether amide is generally a copolymer of polyether and polyamide, the polyamide has a relatively low pairamide group concentration, reduces intermolecular hydrogen bonds, and has significantly reduced crystallinity. This seems to be because the aldehyde condensation polymer of a phenol compound has a bulky structure and is easily compatible with this polyether amide, so that it tends to act on the amide group.

In addition, the phenolic compounds in the present invention include ortho- and para-substituted products such as oxybenzoic acid alkyl esters, halogenated phenols, and alkylphenols;
These aldehyde condensation polymers form thermoplastic condensation polymers with the phenol group remaining intact. Among these, oxybenzoic acid alkyl esters are suitable for the phenolic compound of the present invention.

There are various aldehydes, but formaldehyde is convenient. These aldehyde condensation polymers are polymeric polymers)
It is added in a proportion of 5 to 30 parts by weight per 100 parts by weight of l/27. If it is less than 6 parts by weight, the effect is low;
If the amount is more than part by weight, the properties of the matrix will be impaired without changing the effect.

In addition to the above-mentioned polyether amide or a mixed material of this and polyamide, examples of the sintered polymer matrix used in the present invention include carboxyl group-containing polyolefins known under trade names such as Surlyn and Atmer, acrylonitrile-containing polymers, and hydroxyl group-containing polymers. It is possible to use a mixture of a containing polymer, a fluorine-based polymer, etc., and a polyether amide.

Effects of the Invention According to the present invention, a polymer thermosensitive material whose characteristics change due to humidity is extremely small can be obtained.

Claims (7)

[Claims] (1) A polymer thermosensitive material in which an aldehyde condensation polymer of a phenolic compound is added to a polymer matrix containing polyetheramide having undecaneamide units or dodecanamide units. (2) The polyether component of the polyether amide is
The polymer thermosensitive material according to claim 1, which is a polyolefin oxide. (3) The polymer thermosensitive material according to claim 2, wherein the polyolefin oxide is at least one selected from the group consisting of polyethylene oxide, polypropylene oxide, and polybutylene oxide. (4) The polymer thermosensitive material according to claim 1, wherein the phenolic compound is at least one selected from the group consisting of oxybenzoic acid esters, halogenated phenols, and alkylphenols. (5) The polymer thermosensitive material according to claim 4, wherein the oxybenzoic acid ester is an alkyl p-oxybenzoic acid ester, and the aldehyde is formaldehyde. (6) The polymer thermosensitive material according to claim 1, wherein the addition ratio of the aldehyde condensation polymer is 5 to 30 parts by weight per 100 parts by weight of the polymer matrix. (7) Claim 5, wherein the polymer matrix comprises a mixture of polyetheramide and polydodecaneamide.
Polymer thermosensitive material described in Section 1.