JP2003095732A - Method of producing electroconductive alumina ceramics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively produce electroconductive alumina ceramics which has high mechanical strength and high electrical conductivity. SOLUTION: Tin oxide (SnO2 ), titanium oxide (TiO2 ), or nickel oxide (NiO) of 5 to 40 wt.% in an inner percentage, and copper oxide (Cu2 O) of 0.1 to 10 wt.% is added to alumina (Al2 O3 ), and compacted and burned. The electroconductive alumina ceramics having a volume resistivity of 10<6> to 10<11> Ω.cm is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a conductive alumina ceramic.
In particular, mechanical strength and conductivity
The present invention relates to a conductive alumina ceramic having an improved level. [0002] 2. Description of the Related Art Conventionally, parts for removing static electricity, ceramics
Conductive alumina sensors for heaters, ceramic sensors, etc.
Lamix is used. This alumina ceramic
Is inherently highly insulating, and has high conductivity (volume resistance).
10 at the rate⁷-10¹¹Ω · cm)
nO₂There is a method of adding a conductivity-imparting material such as
You. However, aluminum, which is originally an insulating material,
In order to make the ceramics have high conductivity, Sn
O₂Must add more conductivity-imparting material such as
However, in this case, the sintering of the alumina ceramic
Impairs the bondability and leaves pores inside the sintered body, reducing the mechanical strength
May cause a decrease. As a countermeasure, hot press
Sintering and HIP processing, but productivity and cost
It is not preferable from the aspect of. [0004] Therefore, the mechanical strength is
Strong, highly conductive conductive alumina ceramics at low cost
Method for producing conductive alumina ceramics
Was requested. [0005] The present invention has been made in view of the above circumstances.
Conductive aluminum with high mechanical strength and high conductivity
Conductive alumina ceramics that can produce ceramics at low cost
It is intended to provide a method for producing a mix. [0006] Means for Solving the Problems To achieve the above object,
According to one embodiment of the present invention, alumina (Al₂O
₃) As the main component, and tin oxide (SnO)₂), Oxidation
Tan (TiO₂) Or nickel oxide (NiO)
5 to 40% by weight of copper oxide (Cu₂O).
1-10% by weight is added, molded, fired, and volume resistivity
Is 10⁶-10^{1 1}Ω · cm conductive alumina ceramic
Conductive ceramics, characterized by the production of powder
A method for manufacturing a box is provided. This allows for mechanical strength
Highly conductive alumina ceramics with high conductivity
It can be manufactured at low cost. [0007] BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a conductive aluminum alloy according to the present invention will be described.
A method for manufacturing a mineral ceramic will be described. Alumina (Al)₂O₃) Powder as the main component
And tin oxide (SnO)₂), Titanium oxide (Ti
O₂) Or a kind of nickel oxide (NiO) powder
5-40% by weight of copper oxide (Cu₂O) powder
0.1 to 10% by weight and mixed in water to form a molding aid.
And granulate with a spray dryer, etc., and press molding,
Molding by casting, extrusion, injection molding, etc.
obtain. [0009] After the obtained molded body is degreased as required, it is emptied.
For example, firing at 1400 to 1600 ° C. in the air. What
Note that the firing atmosphere is not limited to air, but a non-oxidizing atmosphere or reduction
It may be an atmosphere. The conductive alumina ceramic according to the present invention
Sintering by hot press and HIP processing
Is not performed, so productivity is good and conductive alumina ceramic
Can be manufactured at low cost. Further, the conductive alumina ceramic according to the present invention is provided.
Ceramic firing manufactured using the mix manufacturing method
The consolidation consists of tin oxide (SnO) around the alumina crystals.₂),acid
Titanium chloride (TiO₂) Or nickel oxide (Ni
O) and copper oxide (Cu₂O) as grain boundaries
Exists and is derived from the connection of these grain boundaries.
Electricity is obtained. Copper oxide has the effect of increasing conductivity.
Both work as sintering aids, just by adding tin oxide
Has the effect of reducing pores remaining inside the sintered body
is there. In this case, the amount of tin oxide added is 5% by weight or less.
In this case, a sufficient conductivity effect cannot be obtained. Meanwhile, tin oxide
If the amount of addition is more than 40% by weight, the porosity increases and the density increases.
No sintered body can be obtained. Further, the addition amount of copper oxide is 0.1
If it is less than 10% by weight, the effect as a sintering aid cannot be obtained.
You. On the other hand, at 10% by weight or more, the porosity becomes small.
But low mechanical strength due to low alumina content
And the volume resistivity becomes too low. As described above, the conductive aluminum according to the present invention
Conductive aluminum manufactured by the method of manufacturing ceramics
Mina ceramics have a volume resistivity of 10⁶-10¹¹Ω
・ Eliminates static electricity that is charged in cm and quickly escapes
Parts, parts for removing static electricity, ceramic heaters, ceramics
It can be used for a mix sensor or the like. [0014] EXAMPLES (Test 1) Alumina (Al₂O₃) Powder and acid
Tin oxide (SnO₂) Powder and copper oxide (Cu₂O) Powder
Mix in water at the ratio shown in 1 and add the molding binder.
And granulated with a spray dryer. Granulated powder obtained
98.1 MPa (1000 kgf / cm²) To plate
After molding, after degreasing at 900 ° C, 1500 in a hydrogen atmosphere
Sintered at 2 ° C. for 2 hours. Volume resistivity, curve of the obtained sintered body
Porosity and porosity were measured. Table 1 shows the results. [0015] [Table 1] Embodiments 11, 12, and 13
Have a volume resistivity of 10⁶-10¹¹Ω · cm
Controlled and porosity is small,
It was found that bending strength was obtained. In contrast, the acid
Tin oxide (SnO₂) Is 1% by weight and the lower limit is 5% by weight
Comparative Example 11 is smaller in porosity,
Large bending strength can be obtained, but volume resistivity
10¹⁴Ω · cm and 10 ⁶-10¹¹Ω · cm range
It turned out that conductivity fell. Also, tin oxide
(SnO₂) Is 50% by weight and the upper limit is 40% by weight.
Comparative Example 12 having a larger porosity than
It was found that a high bending strength could not be obtained. Further, in Example 12, copper oxide (C
u₂Example 14 in which the addition amount of O) was changed to the range limit,
In Example 15, the volume resistivity was 10⁶-10¹¹
Ω · cm and the porosity is kept low
It was found that a large bending strength was obtained. to this
On the other hand, copper oxide (Cu₂O) added amount is 0.05% by weight
And Comparative Example 13 smaller than 0.1% by weight has a large porosity.
It turns out that large bending strength cannot be obtained
Was. In addition, copper oxide (Cu₂O) is 20
Comparative Example 14 in which the weight% is larger than the upper limit of 10 weight%.
Means that the porosity decreases, but the mechanical strength decreases.
It turns out that the volume resistivity is too low
Was. (Test 2) Tin oxide (SnO) in Test 1₂)powder
Instead of powder, titanium oxide (TiO₂) Add other conditions
Was the same as in Test 1. Table 2 shows the results. [0020] [Table 2] Embodiments 21, 22, and 23
Have a volume resistivity of 10⁶-10¹¹Ω · cm
Controlled and porosity is small,
It was found that bending strength was obtained. In contrast, the acid
Titanium chloride (TiO₂) Is less than 5% by weight
In Comparative Example 21, the porosity was suppressed to a small value.
Bending strength is obtained, but the volume resistivity is 10^ThirteenΩ
cm and 10⁶-10¹¹Ω ・ cm out of range, conductive
Was found to decrease. In addition, titanium oxide (TiO 2)
₂) Is 50% by weight, which is larger than the upper limit of 40% by weight.
Comparative Example 22 has a high porosity and a large bending strength.
It turned out that the degree could not be obtained. Further, in Example 22, copper oxide (C
u₂Example 24 in which the addition amount of O) was changed to the range limit,
In Example 25, the volume resistivity was 10⁶-10¹¹
Ω · cm and the porosity is kept low
It was found that a large bending strength was obtained. to this
On the other hand, copper oxide (Cu₂O) added amount is 0.05% by weight
And Comparative Example 23 smaller than the lower limit of 0.1% by weight
Rate and the large bending strength cannot be obtained.
won. Further, copper oxide (Cu₂O) is 20
Comparative Example 24 in which the weight% and the upper limit of 10 wt% were larger than
The porosity decreases, but the mechanical strength decreases.
It turns out that the volume resistivity is too low
Was. (Test 3) Tin oxide (SnO) in Test 1₂)powder
Nickel oxide (NiO) powder is added instead of powder, and other
The conditions were the same as in Test 1. Table 3 shows the results. [0025] [Table 3] Embodiment 31, Embodiment 32 and Embodiment 33
Have a volume resistivity of 10⁶-10¹¹Ω · cm
Controlled and porosity is small,
It was found that bending strength was obtained. In contrast, the acid
1% by weight of nickel oxide (NiO) and lower limit of 5 weight
Comparative Example 31 in which the porosity is smaller than
High bending strength can be obtained, but volume resistance
Rate is 10^ThirteenΩ · cm and 10⁶-10¹¹Ω ・ cm range
It was found that the surroundings were removed and the conductivity was lowered. Also acid
The addition amount of nickel oxide (NiO) is 50% by weight and the upper limit value 4
Comparative Example 32 in which the porosity is larger than 0% by weight is remarkably large.
It turns out that large bending strength cannot be obtained
Was. Further, in Example 32, copper oxide (C
u₂Example 34 in which the addition amount of O) was changed to the range limit,
In Example 35, the volume resistivity was 10⁶-10¹¹
Ω · cm, and the porosity in Test 1 and Test 2
Is larger than each other sample, but compared to other samples in this test 3.
It can be seen that a large bending strength can be obtained
won. In contrast, copper oxide (Cu₂O)
Comparison between 0.05% by weight and lower limit of 0.1% by weight
In Example 33, the porosity was increased and a large bending strength was obtained.
I knew it wasn't. In addition, copper oxide (Cu₂O)
Comparison where the added amount is larger than 20% by weight and the upper limit of 10% by weight
Example 34 has lower porosity but lower mechanical strength.
And the volume resistivity may be too low
all right. [0028] According to the present invention, the conductive alumina ceramic according to the present invention is provided.
According to the manufacturing method of the box, the mechanical strength is strong,
An inexpensive method for producing highly conductive alumina ceramics
To provide a method for producing electrically conductive alumina ceramics
it can.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Hiroko Ueno             30 Toya, Hadano-shi, Kanagawa Toshiba Ceramics             KUSU Corporation Hadano Office F term (reference) 4G030 AA16 AA29 AA31 AA36 AA39                       BA02 BA20 CA05 GA05 GA14                       GA22 GA24 GA26 GA28

Claims (1)

Claims 1. An alumina (Al ₂ O ₃ ) as a main component,
In addition, tin oxide (SnO ₂ ), titanium oxide (TiO ₂ )
Alternatively, nickel oxide (NiO) is applied for 5 to 40
% By weight, 0.1 to 10% by weight of copper oxide (Cu ₂ O) is added, molded, and fired to have a volume resistivity of 10 ⁶ to 10 ^11.
A method for producing conductive alumina ceramics, comprising producing conductive alumina ceramics of Ω · cm.