JPS6141127B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polymeric temperature sensitive body made of a specific polyamide resin composition, particularly to the temperature resistance value of a heat sensitive material in a device that controls temperature using a capacitance component as one control factor. The present invention relates to a polymer temperature sensitive body with improved impedance or capacitance behavior.

Polymer thermosensitive materials are often used as constituent materials for electric wires for heating elements such as electric blankets and electric carpets. (2) small fluctuations in electrical characteristics depending on the environment in which the heating element is used, especially humidity; (3) mechanical strength and electrical properties within the normal operating temperature range. (4) It has a clear melting temperature around 200℃ in order to cope with abnormal temperature rises.

Polymer materials conventionally known to be used as thermosensors include polyvinyl chloride, cellulose esters, polyamides, copolymers of acrylic esters and acrylonitrile (Japanese Patent Publication No.
Publication No. 1627, Special Publication No. 7635, Special Publication No. 1976-
(Refer to Publication No. 14179). Examples of applications of heat-sensitive temperature control lines or surfaces using these polymeric materials are shown in FIGS. 1A and 1B. A is a partially cutaway perspective view showing an example of a heat-sensitive temperature control line, which essentially consists of an insulating material 1, a core wire 2, a polymer temperature-sensitive body 3, a signal line 4, and a heater line 5. Alternatively, B is a sectional view showing an example of a heat-sensitive temperature control surface. With this configuration, the temperature can be controlled along the heat-sensitive temperature control line or surface by utilizing the fact that the electrical properties of the polymer temperature-sensitive body 3, that is, the resistance value, impedance, or capacitance, change depending on the temperature. It is something that is detected and controlled.

Among the polymer materials mentioned above that are known as polymer thermosensors, polyamide resin has
It is often used as a polymer thermosensitive material because it has excellent mechanical properties, heat resistance, moldability, etc. Furthermore, polyamide resin is a crystalline polymer and has a clearer melting point than other resins, making it possible to cope with abnormal temperature rises. In other words, when a polyamide resin is used for the polymer thermosensitive body 3 shown in FIGS. 1A and B, the melting point of the polyamide resin is around 200°C, and the temperature of the exothermic wire may rise to a temperature higher than the melting point due to abnormal temperature rise. Then, the polymer thermosensitive body melts, causing a short circuit between the heating wire 5 and the signal wire 4 shown in FIGS. 1A and 1B, and it becomes possible to operate the stabilizer.

In order to make the rate of change in resistance, impedance, or capacitance due to temperature even more remarkable in the operating temperature range as a polymer thermosensor, for example, Japanese Patent Publication No. 14179/1983 describes the There is a description of producing a polymer temperature sensitive composition in which an ionic surfactant, that is, a cationic or anionic surfactant is blended with vinyl chloride or polyamide resin.

However, these ionic surfactants have poor heat resistance, and polyvinyl chloride is also inferior to heat-resistant polyamide resins, and unlike polyamide resins, it does not have a clear melting point and cannot cope with abnormal temperature rises. However, it has not yet reached a level where it can be put to practical use. Further, when an ionic surfactant is blended with a well-known polyamide resin such as Nylon 6 or Nyone 66, it cannot be blended because the ionic surfactant has poor heat resistance. In other words, it is possible to add surfactants such as stearyldimethylbenzylammonium chloride described in Japanese Patent Publication No. 35-14179 to polyamide resin to increase the temperature change in its electrical properties. However, its heat resistance is too poor to be kneaded into polyamide resin, so it is almost impossible to knead it into polyamide resin.

In addition, typical polyamide resins such as nylon 6 or nylon 66, as described in Japanese Patent Publication No. 26-1627, have too high water absorption performance as heat-sensitive materials, so they are not suitable for use in electric blankets, for example. As is already known as a heat ray, even if a moisture-proofing skin made of polyvinyl chloride or the like is formed as the outermost layer, it is difficult to obtain substantially complete moisture-proofing. For this reason, the control temperature point of a heat sensitive body using nylon 6, nylon 66, or the like fluctuates significantly depending on the environmental conditions in which it is placed. In other words, nylon 6 or nylon 66 has too high water-absorbing ability and its electrical properties vary significantly depending on the environmental conditions in which it is used, so it is practically impossible to use it as a heat-sensitive wire for electric blankets, electric carpets, etc. . This disadvantage increases synergistically when water-absorbing additives such as surfactants are added.

Therefore, the present inventor made a comprehensive study on various polyamide resins, and as a result, polyamide resins having 14 or less amide groups per 100 carbon atoms, such as nylon 11, nylon 12, nylon 6, 12, etc. These polyamide resins have low water absorption and have excellent other physical properties, so if they are used as polymer materials for polymer thermosensitive materials,
It has been found that there is no fluctuation in electrical properties as with the above-mentioned nylon 6 or nylon 66, and that an excellent heat-sensitive material can be provided. Furthermore, the number of carbon atoms in these nylon 12 etc.
As a result of studying various additives to improve electrical properties using polyamide resin with 14 or less amide groups per 100, we found the general formula (1). (In the formula, l and m are numbers within the range of 0≦l≦10, 2≦m≦10, and R ₁ , R ₂ , and R ₃ may be the same or different, and the number of carbon atoms It has been found that the electrical properties are significantly improved by adding a compound represented by the following formula (which is an alkyl group or an alkoxy group having 1 to 10 atoms). In other words, it has been found that a polyamide resin composition to which such an additive has been added greatly increases the rate of change in resistance, impedance, or capacitance due to temperature, and exhibits properties that are truly desirable as a polymer thermosensitive material for electric blankets and the like. It was. In addition, the electrical property agent made of the compound represented by the general formula (1) used in the present invention has excellent heat resistance and can be practically kneaded into polyamide resin, and when used in electric blankets, electric carpets, etc. It was also found that the electrode has excellent corrosion resistance.

That is, the present invention applies a compound represented by the above formula (1) to a low water absorption polyamide resin made of a polyamide resin having 14 or less amide groups per 100 carbon atoms, such as nylon 11 or nylon 12. It has been discovered that this polymeric thermosensitive material is made of a polyamide resin composition containing 0.01 to 10% by weight of polyamide resin, and that the composition material becomes an excellent polymeric thermosensitive material.

The polyamide resin having 14 or less amide groups per 100 carbon atoms used in the present invention includes:
A low water absorption polyamide resin made of a nylon copolymer whose main component is a polyamide resin component as described above may also be used.

Examples of the compound represented by the general formula (1) include N-β-(aminoethyl)-γ-aminopropyltriethoxylane, N-β-(aminoethyl)
-γ-aminopropyltrimentoxysilane, N
-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and the like.

Further, the amount of the compound represented by the general formula (1) in the present invention varies depending on the polyamide resin or the type of the compound, but it is generally added in an amount of 0.01 to 10 wt% relative to the polyamide resin. 0.01wt
If it is less than 10% by weight, it will not show electrical properties that can be put to practical use, and if it exceeds 10wt%, there is a risk that the mechanical properties of the polyamide resin will deteriorate, and the additive will lead over time, causing changes in electrical properties over time. This is because there is a risk that it will show.

Furthermore, it is also possible to coexist the above-mentioned compounds of the present invention with other ionic compounds, such as potassium iodide, copper iodide, etc., to further improve the electrical properties due to the synergistic effect of the additives.

When adding and mixing the compound represented by the general formula (1) to a polyamide resin, there is no particular limitation on the method of addition, as long as the compound can be uniformly dispersed in the polyamide resin, and generally it is done by extrusion. Melt extrusion mixing is possible. During melt extrusion, other additives such as plasticizers, light stabilizers, heat stabilizers, fillers, flame retardants, colorants, etc. may be added to the extent that they do not affect the electrical properties of the composition. This does not in any way impede the purpose of the present invention.

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

Example 1 2.0wt% formula in nylon 12 pellets (Diamide L-1901 registered trademark of Daicel Corporation) A compound having the structure shown was thoroughly mixed in advance using a Henschel mixer, and then melt-blended using an extruder (polymer temperature: about 220°C) to obtain blend pellets with a good appearance. Next, this pellet is compression molded (polymer temperature approximately 210°C) between approximately 0.2mm of aluminum foil of approximately 50μ.
Create a sheet as a form of thick thermosensor,
The dielectric property of this sheet at 1KHz is 20℃
Measurements were made in the temperature range of ~120°C and the results shown in Figure 2A were obtained. For comparison, the dielectric properties of the original nylon 12 polymer were measured under similar conditions, and the results shown in Figure 2B were obtained. It is clear from these results that the rate of change in dielectric constant with temperature is improved compared to the original nylon 12 polymer.

Furthermore, the impedance characteristics were measured at an electric field strength of 1 KV/cm (450 Hz), and the results are shown in Figure 3. However, signals A and B are the same as in the case of FIG.

From this result, it is clear that the temperature change rate of impedance is improved compared to the original nylon 12 polymer.

Example 2 The formula was added to nylon 12 by the same method as in Example 1.
The dielectric properties and impedance properties of a mixture of 2.0wt% of a compound having the structure shown by H ₂ N(CH ₂ ) ₂ HN(CH ₂ ) ₃ Si(OCH) ₃ were measured, and the results are shown in Figure 2. and is shown as C in FIG. From this result, it is clear that the temperature change rate of dielectricity and impedance is improved compared to the original polyamide resin.

[Brief explanation of the drawing]

FIG. 1A is a partially cutaway perspective view showing an example of a heat-sensitive temperature control line, B is a sectional view showing an example of a heat-sensitive temperature control surface, and FIG. 2 is a graph showing the dielectric properties of a polymer temperature sensitive body. FIG. 3 is a graph showing impedance characteristics. 1... Insulating material, 2... Core wire, 3... Polymer temperature sensitive body, 4... Signal line, 5... Heater wire.

Claims (1)

[Scope of Claims] 1. A polyamide in which 0.01 to 10% by weight of a compound represented by the following general formula (1) is blended as at least one component into a polyamide resin having 14 or less amide groups per 100 carbon atoms. A polymer thermosensitive body made of a resin composition. (In the formula, l and m are numbers within the range of 0≦l≦10, 2≦m≦10, and R ₁ , R ₂ , and R ₃ may be the same or different, and carbon It is an alkyl group or an alkoxy group having a number of 1 to 10.