JPS6011442B2 - polymer thermosensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polymer temperature sensitive body used in a temperature sensing device for controlling the temperature of a heat generating element such as an electric blanket, an electric bedcloth, or an electric carpet.

The thermosensitive element according to the present invention is a thermosensitive heater that not only has a temperature control function but also has the function of melting the temperature sensitive element within a narrow temperature range and cutting off the heater circuit when the temperature of these heating devices increases abnormally. It is used as a heat sensitive body. Conventionally, homopolymers such as nylon-11 and nylon-12, or nylon copolymers mainly composed of nylon-12 have been used as heat-sensitive members.

However, homopolymers such as nylon-11 and nylon-12 have a small temperature coefficient of impedance and therefore have a low temperature detection function, but on the other hand, they exhibit sharp melting behavior and exhibit excellent characteristics for use as thermal fuses.

On the other hand, a nylon copolymer mainly composed of L nylon has a high temperature coefficient of impedance, but exhibits broad melting behavior, so although it is suitable for temperature detection functions, it is not suitable for use as a thermal fuse. The inventors of the present invention have intensively investigated a polymer thermosensitive material that has excellent temperature detection function and exhibits sharp melting behavior. They found that only nylon copolymers satisfy these conditions, and completed the present invention.

That is, the present invention provides (1) 6.12 salt and (b) 612 salt.
A lactam or aminocarboxylic acid having 6 to 13 carbon atoms other than the grave, or a condensate of an alkylene diamine having 6 to 1 carbon atoms and an alkanedicarboxylic acid having 6 to 1 carbon atoms, in weight ratio. This invention relates to a polymeric overflow body made of a copolyamide resin copolymerized in a ratio of 50:190:50:10.

It is a well-known fact (Japanese Patent Publication No. 51-10355) that nylon copolymers are excellent as thermosensors, and can be used as thermosensors.

However, these nylon copolymers have broad melting behavior and cannot have a thermal fuse function. The fact that the melting behavior becomes broader is explained as being due to an increase in amorphousness due to copolymerization, and this is also a generally known fact. Furthermore, nylon copolymers have a low crystallization temperature and a broad crystallization behavior, so they also have the disadvantage of poor moldability. However, surprisingly, nylon 6
．． The nylon copolymer obtained by copolymerizing 50 to 9 parts by weight of the 12 components and 50-1 parts by weight of other polyamide-forming monomers has a large temperature coefficient of impedance, and also exhibits sharp melting and crystallization behavior. I saw what was going to happen and put it out there. Other than the 6.12 salt of (b) used in the present invention and having 1 carbon number
Other substances capable of producing polyamides having a carbon number of 3 or less include lactams or aminocarboxylic acids having 6 to 1 carbon atoms, alkylene diamines having 6 to 1 carbon atoms, and alkanes having 6 to 1 carbon atoms. Condensates of dicarboxylic acids (nylon salts) are suitable.

Examples of the former include laurinlactam and caprolactam.
Capryllactam, ■-aminocapric acid, aminobelagoic acid, ■-aminoundecanoic acid, Yamaichi aminotridecanoic acid, etc. Examples of condensates of the latter include hexamethylenediamine adipate, hexamethylenediamine sebacin, etc. salts, nylon salts such as hexamethylene diamine tridecane dicarboxylate, and salts of the above alkanedicarboxylic acids with decamethylene diamine or tridecane diamine.The nylon copolymer of the present invention includes hexamethylene diamine and An equimolar mixture of dodecanedioic acid or its salt (6.12 mirror) and the above 6.12
It is obtained by carrying out a copolymerization reaction in the coexistence of one or more types of polyamide-forming monomers other than summer.

Furthermore, commonly used heat stabilizers and electrical property improvers for nylon, such as metal halides, can be added to the polymer temperature sensitive body of the present invention.

Examples 1 to 4 6.12 parts by weight of laurolactam and laurolactam shown in Table 1 and 5 parts by weight of water are placed in a bag in a pressure vessel, and the reaction system is completely replaced with nitrogen.

Next, after raising the temperature of the bag to 280°C, the fly worship was started, and 1
The reaction is allowed to proceed for 6 hours under a controlled pressure of 5 atm. The pressure is reduced to normal pressure within 1 hour after the reaction, and the reaction is carried out at the same temperature under a nitrogen stream for 3 hours. After the polymerization reaction was completed, the polymer was extruded from a pressure vessel using nitrogen pressure to form pellets. The glue rel (0.5 m/100 kites-cresol) of these polymers is 1.9
It was ~2.0. In addition, the amount of chloroform extracted, that is, the residual monomers and oligomers is 1.0 to 1. It was turtle weight %. The thermistor B constant of these polymers was determined using an electrode with a guard electrode at an electric field strength of 1000 V' (50 Hz).
It was measured with

Table 1 shows thermistor B constants from 40 to 600○. 6.12 It can be seen that as the wealth decreases, the thermistor B constant increases and the thermistor has characteristics as a temperature sensitive element.

Furthermore, we investigated the melting behavior of the same sample amount by 1 in a nitrogen stream.
Measurement was carried out at a heating rate of min. The broadness of the melt gap behavior was investigated from the half width of the obtained melting curve, and is shown in Table 1.

The melting behavior is very sharp despite the progress of copolymerization due to the decrease in 6.12 enrichment. That is, it is understood that it also has a thermal fuse function. Comparative Example 1 A copolymer of 3 parts by weight of 6.12 salt and 7 parts by weight of laurolactam was obtained by the same operation as in Example 1, and the thermistor B constant and half width were measured.

The results are shown in Table 1, and the half width is significantly larger than that of the product of the present invention, and although it has a temperature detection function, it does not have a temperature fuse function.

Comparative Example 2 A copolymer of 3 parts by weight of caprolactam and 7 parts by weight of laurolactam was obtained by the same operation as in Example 1.
The Mr. B constant and half width were measured.

The results are shown in Table 1, and the half width is larger than that of the product of the present invention, and even though it has a temperature detection function, its thermal fuse function is extremely poor. Table 1 Example 5 By the same operation as in Example 1, 70 parts by weight of 6.12
A copolymer was obtained from 25 parts by weight of laurolactam and 5 parts by weight of caprolactam.

Claims (1)

[Claims] 1 (I) 6.12 salt and (II) Lactam with 6 to 13 carbon atoms or ω-aminocarboxylic acid or alkylene diamine with 6 to 13 carbon atoms and 6 to 13 carbon atoms other than (II) 6.12 salt 1. A polymer thermosensitive material comprising a copolyamide resin copolymerized with a condensate of 13 alkanedicarboxylic acids in a weight ratio of 50-90:50-10.