JPS5927741B2 - Thermistor composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel thermistor composition that is stable and has a low specific resistance.

As a thermistor material whose resistance value has a negative gradient with respect to temperature, two or more types of oxides such as Mn, Co, Ni, Fe, Cu, Al, Si, etc. are mixed and heat-treated at 900 to 1300°C and baked. Composite oxides are well known.

Among these, the composite oxide containing Cu has a specific resistance of 100Ω.
- Some are smaller than a sieve and are used as low-resistance thermistor materials.

However, this thermistor material containing Cu has a large change in resistance value over time, exceeding +10%, and lacks stability.
It cannot be used for highly accurate temperature detection or as a temperature compensation element.

Therefore, the thermistor constant is large and the specific resistance is small.
Stable thermistor materials are required.

An object of the present invention is to provide a thermistor material with low resistance and particularly excellent stability.

The present invention provides at least one type of oxide selected from oxides of Mn, Co, and Ni as a thermistor material;
Thermistor material Fe, A7. In a composite oxide obtained by mixing, pulverizing, and firing at least one oxide selected from oxides of Si and an oxide of Mo, up to 50% of atoms in the composite oxide are Mo. It is characterized by

Here, the reason why the MO content is set to 50% atoms is that if the material composition is higher than this, the temperature change in resistance value, that is, the thermistor constant becomes small, and the material does not exhibit the characteristics as a thermistor.

Note that the composition including Mo is a conventional thermistor material.

The present invention will now be described with reference to Examples.

Example 1 Using MnO2, CoO2, Fe2O3, and MOO2 as starting material powders, 50 g was weighed out so as to have the composition shown in Table 1.

These powders are gently mixed for 4 hours using an agate mortar.

Put this mixed powder into an aluminum crucible and
900℃ in a vacuum atmosphere below H9.

After pre-calcining for 2 hours, this powder was further ground in an agate mortar for 4 hours.

Next, a pellet of 12.0φ x 3.0t is made using a pressure press, and heat treated at 950° C. for 8 hours in a vacuum of 10 −2 mmHg or less to produce a ceramic.

Conductive paint was applied to both sides of this ceramic to form electrodes, and thermistor characteristics were measured.

Furthermore, its stability was investigated by leaving it at a high temperature of 150° C. for 2000 hours.

However, Sample No. 161 in Table 1 is a well-known thermistor material and is listed for reference.

Those containing up to 50% of Mo atoms in /I62 to 512 in Table 1 have lower resistivity and better stability than those in Table 1 that do not contain Mo.

/l613 containing 52% Mo atoms has a small thermistor constant and is less useful as a thermistor.

Example 2 Mn02. Fe2o3. Using MnO as a starting material powder, ceramics having the compositions shown in Table 2 were produced using the same manufacturing method as in Example 1, and their thermistor characteristics were measured.

In addition, its stability was investigated by leaving it at a high temperature of 150°G for 2000 hours.

Those containing up to 50% Mof atoms of /I62 to /i6.12 in Table 2 are compared to those containing no Mo of /161,
The specific resistance is small and the stability is good.

A613 containing 52% atomic Mo has a small thermistor constant and is less useful as a thermistor.

Example 3 Using Mn203, Co3O4, Fe2O3, and MoO2 as starting material powders, ceramics having the compositions shown in Table 3 were produced in the same manner as in Example 1, and their thermistor characteristics were measured.

Further, the stability was investigated by leaving it at a high temperature of 150° C. for 2000 hours.

Those containing up to 50% Mo of /6.2 to /1612 in Table 3 have lower specific resistance values and better stability than those of /I6.1 that do not contain Mo.

413 containing 52% Mo atoms has a small thermistor constant and is not useful as a thermistor.

Example 4 Using Mn02, NiO, A120s, and MoO2 as starting material powders, ceramics having the compositions shown in Table 4 were produced in the same manner as in Example 1, and their thermistor characteristics were investigated.

Further, the stability was investigated by leaving it at a high temperature of 150° C. for 2000 hours.

Those containing up to 50% Mo of atoms of /162 to A612 in Table 4 have lower specific resistance and better stability than those of A6.1 that do not contain Mo.

/16.13 M. A material containing 52% of atoms has a small thermistor constant and is not useful as a thermistor.

Example 5 Coo, Fe2O3,5i02. Using MoO2 as a starting material powder, ceramics having the compositions shown in Table 5 were produced using the same manufacturing method as in Example 1, and their thermistor characteristics were measured.

Further, the stability was investigated by leaving it at a high temperature of 150° C. for 2000 hours.

Those containing up to 50% Mo atoms of /162 to /1612 in Table 5 have lower resistivity and better stability than those containing no Mo of 1.

M of Bian 13. A material containing 52% of atoms has a small thermistor constant and is not useful as a thermistor.

Example 6 Mn02, CoO, Nio, A#203. Fe
Using 2O3,5io2°MoO2 as a starting material powder, ceramics having the compositions shown in Table 6 were produced in the same manner as in Example 1, and their thermistor characteristics were investigated.

Furthermore, the stability was investigated by leaving it at a high temperature of 150° C. for 2000 hours.

Those containing up to 50% Mo atoms of /162 to /1612 in Table 6 have lower resistivity and better stability than those of A1 that do not contain Mo.

, 4613 M. A material containing 52% of atoms has a small thermistor constant and is not useful as a thermistor.

As mentioned above, 50% of the total amount of metal components in the composite oxide
By including Mo down to the atoms, it became possible to create a low-resistance and stable thermistor material, and it was possible to provide a low-resistance thermistor element with excellent stability.

Claims (1)

[Claims] 1. M which is a thermistor material exhibiting thermally negative resistance characteristics
at least one metal oxide selected from oxides of n, Co, and Ni, and a thermistor material exhibiting negative thermal resistance characteristics such as Fe, Si, and Al. In a composite oxide material obtained by mixing, crushing, and firing at least one metal oxide selected from the oxides of molybdenum and an oxide of molybdenum, up to 50% atoms of the metal components in the composite oxide A thermistor composition characterized in that is molybdenum.