JPH0782020A - Columnar particles and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] Synthesis and properties of oriented dielectric ceramics
Large aspe useful for the synthesis of composite materials with anisotropy of
To provide columnar particles having a cut ratio. [Structure] The basic composition is xZrO₂-YSnO₂-Z
TiO₂(However, 0.6≤x≤1.0, 0≤y≤0.
4, 0.8 ≦ z ≦ 1.2. ) And the aspect
Columnar particles having a ratio of 10 or more
The columnar particles have the above-mentioned basic composition upon firing.
Against SiO₂, Bi₂O₃, Cr ₂O₃, V₂O_Five
And at least one selected from the group consisting of NiO
It can be produced by adding a compound to the flux.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to anisotropically shaped columnar particles useful for synthesizing oriented dielectric ceramics or composite materials having anisotropy of characteristics, and particularly Zr-Sn.
The present invention relates to columnar particles having a —Ti—O-based composition (hereinafter abbreviated as ZST) and a method for producing the same. Further, the columnar particles having a Zr—Ti-based composition that does not contain Sn may be, for example, Pb.
It is useful as a precursor when synthesizing columnar particles having a (ZrTi) O ₃ system composition.

[0002]

2. Description of the Related Art Recently, attempts have been made to synthesize particles having shape anisotropy for the purpose of obtaining anisotropic properties. For example, 1988 Ceramic Industry Association Annual Meeting Proceedings, 348
(1988) shows that TiO ₂ and ZrO ₂ and KCl or Na ₂ SO ₄ as a flux are dry-mixed and fired to form a columnar Zr having an aspect ratio of about 7.
It is reported that TiO ₄ particles are obtained. However, in order to obtain a highly anisotropic porcelain or composite material, particles having a larger aspect ratio are desired.

[0003]

[Means for Solving the Problems]
As a result of earnest studies for the purpose of obtaining columnar ZST particles having a large aspect ratio, the present invention has been found.

The present invention has a basic composition of xZrO ₂ -yS.
nO ₂ -zTiO ₂ (provided that 0.6 ≦ x ≦ 1.0, 0
≦ y ≦ 0.4 and 0.8 ≦ z ≦ 1.2. ), And
The present invention relates to columnar particles having an aspect ratio of 10 or more.

In the present invention, the basic composition is xZrO ₂
-YSnO ₂ -zTiO ₂ (provided that 0.6 ≦ x ≦ 1.
0, 0 ≦ y ≦ 0.4 and 0.8 ≦ z ≦ 1.2. ), And SiO ₂ , Bi ₂ O ₃ , C for this basic composition
The present invention relates to a method for producing columnar particles, which comprises adding at least one compound selected from the group consisting of r ₂ O ₃ , V ₂ O ₅ and NiO to a flux and firing the compound.

In the basic composition of the present invention, when x, y and z deviate from the above ranges, a heterogeneous phase is generated, particles other than columnar particles are remarkably generated, and relative dielectric constant, dielectric loss and temperature of resonance frequency are increased. Since the electrical characteristics such as the coefficient deteriorate,
x, y, and z are set in the above range.

According to the manufacturing method of the present invention, columnar particles having a large aspect ratio can be obtained. In order to obtain columnar particles having a particularly large aspect ratio, SiO ₂ , Bi is used.
_It is preferable to add at least 1 part by weight of a compound selected from the group consisting of ₂ O ₃ , Cr ₂ O ₃ , V ₂ O ₅ and NiO to the flux in an amount of 1 part by weight or less based on 100 parts by weight of the basic composition.

In the present invention, the addition amount of SiO ₂ , Bi ₂ O ₃ or Cr ₂ O ₃ is preferably 0.5 parts by weight or less based on 100 parts by weight of the basic composition. Also, V ₂ O ₅
The amount added is 0.3 with respect to 100 parts by weight of the basic composition.
It is preferably less than or equal to parts by weight. Further, the amount of NiO added is preferably 0.18 parts by weight or less based on 100 parts by weight of the basic composition.

The columnar ZST particles of the present invention can be obtained by the following method. For example, ZrO ₂ powder, Sn
O ₂ powder and TiO ₂ powder were mixed with a rafting machine for 15 minutes to 2 hours, and KCl, NaCl, K were used as flux.
₂ SO ₄ , Na ₂ SO ₄ , K ₂ MoO _4, etc. are added, and further SiO ₂ is added and mixed. The mixture is placed in an alumina crucible at 1150 ° C-1300 ° C for 1 hour to 15
Bake for about an hour. After cooling, it is lightly crushed, washed with boiling water, filtered and dried to synthesize columnar ZST particles. (Z
When the molar ratio of rO ₂ + SnO ₂ ) / TiO ₂ deviates from more than 1/1, it cannot form a solid solution and becomes a multiphase (ZrO ₂
The molar ratio of + SnO ₂ ) / TiO ₂ is preferably around 1/1. It is preferable to add 0.5 to 2 times the amount of flux to the total weight of ZrO ₂ , SnO ₂ and TiO ₂ in terms of aspect ratio, ease of cleaning and cost.

[0010]

EXAMPLES The present invention will be described more specifically by showing Examples and Comparative Examples below. Example 1 11.8 g of ZrO ₂ powder having a basic composition, 3.6 g of SnO ₂ powder, and 9.6 g of TiO ₂ powder, 38 g of NaCl as a flux, and 12.5 mg of SiO ₂ were further added, and the mixture was pulverized for 1 hour with a raker. Mixed. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours. After cooling and repeated boiling and washing with water, it was filtered to separate it from the flux and dried at 80 ° C for 12 hours to give a columnar (Zr0.8S
n0.2) TiO ₄ particles were obtained. The aspect ratio was 11. A binder, a plasticizer and a solvent were added to the columnar particles, and a sheet was formed by the doctor blade method. This green sheet was punched into a circular shape, thermocompression bonded and laminated to produce a cylindrical molded body, degreased and fired. When the relative permittivity of the obtained sintered body was measured by the waveguide method, the relative permittivity ε _r was 46.

Example 2 11.8 g of ZrO ₂ powder having a basic composition, 3.6 g of SnO ₂ powder and 9.6 g of TiO ₂ powder, 8 g of NaCl as a flux, 30 g of Na ₂ SO ₄ and further Si.
O _{2 (} 12.5 mg) was added, and the mixture was pulverized and mixed for 1 hour with a raker. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours. After cooling, boiling and washing with water were repeated, followed by filtration to separate from the flux and drying at 80 ° C. for 12 hours to obtain columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles. The aspect ratio was 15.

Example 3 11.8 g of ZrO ₂ powder having a basic composition, 3.6 g of SnO ₂ powder, and 9.6 g of TiO ₂ powder, 8 g of NaCl as a flux, 30 g of Na ₂ SO ₄ and further Si.
O _{2 (} 25 mg) was added, and the mixture was ground and mixed for 1 hour with a raker. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours. After repeated washed in boiling water after cooling, filtered to separate the flux, and dried at 80 ° C. 12 hours to obtain a columnar _{(Zr 0. 8 Sn 0.2) TiO} 4 particles. The aspect ratio was 14.

Example 4 ZrO which is a basic composition₂Powder 11.8g, SnO₂Powder
3.6 g, and TiO₂Powder 9.6g, with flux
Then NaCl 8g, Na₂SO_Four30g, more Si
O₂50 mg was pulverized and mixed for 1 hour with a raker. this
In an alumina crucible and baked at 1225 ° C for 10 hours
It was After cooling, repeat boiling and washing with water, then filter and wash
Of the columnar (Z
r₀.₈Sn _0.2) TiO_FourThe particles were obtained. The aspect ratio is
It was 13.

Example 5 ZrO having a basic composition₂Powder 11.0 g, SnO₂Powder
4.5 g, and TiO₂Powder 9.5g, with flux
Then NaCl 8g, Na₂SO_Four30g, more Si
O₂25 mg was pulverized and mixed for 1 hour with a raker. this
In an alumina crucible and baked at 1225 ° C for 10 hours
It was After cooling, repeat boiling and washing with water, then filter and wash
Of the columnar (Z
r_0.75Sn _0.25) TiO_FourThe particles were obtained. The aspect ratio is
It was 14.

Example 6 ZrO having a basic composition₂Powder 12.6g, SnO₂Powder
2.7 g, and TiO₂Powder 9.6g, with flux
Then NaCl 8g, Na₂SO_Four30g, more Si
O₂50 mg was pulverized and mixed for 1 hour with a raker. this
In an alumina crucible and baked at 1225 ° C for 10 hours
It was After cooling, repeat boiling and washing with water, then filter and wash
Of the columnar (Z
r_0.85Sn _0.15) TiO_FourThe particles were obtained. The aspect ratio is
It was 13.

Comparative Example 1 11.8 g of ZrO ₂ powder having a basic composition, 3.6 g of SnO ₂ powder, 9.6 g of TiO ₂ powder, and 38 g of NaCl as a flux were pulverized and mixed for 1 hour with a raker. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours. After cooling, boiling and washing with water were repeated, followed by filtration to separate from the flux and drying at 80 ° C. for 12 hours to obtain columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles. The aspect ratio was 8.

Example 7 Columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 1 except that Bi ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 11.

Example 8 A columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 2 except that Bi ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 13.

Example 9 Columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 3 except that Bi ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 14.

Example 10 Columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 4 except that Bi ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 15.

Example 11 Columnar (Zr _0.75 Sn _0.25 ) TiO _{4 was prepared in the same} manner as in Example 5 except that Bi ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 14.

Example 12 Columnar (Zr _0.85 Sn _0.15 ) TiO _{4 was prepared in the same} manner as in Example 6 except that Bi ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 15.

Example 13 A columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 1 except that Cr ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 11.

Example 14 Columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 2 except that Cr ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 14.

Example 15 Columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 3 except that Cr ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 16.

Example 16 A columnar (Zr _0.8 Sn _0.2 ) TiO _{4 was} prepared in the same manner as in Example 4 except that Cr ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 13.

Example 17 Columnar (Zr _0.75 Sn _0.25 ) TiO _{4 was prepared in the same} manner as in Example 5 except that Cr ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 16.

Example 18 Columnar (Zr _0.85 Sn _0.15 ) TiO _{4 was prepared in the same} manner as in Example 6 except that Cr ₂ O ₃ was used instead of SiO _2.
The particles were obtained. The aspect ratio was 13.

Example 19 Columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained in the same manner as in Example 1 except that V ₂ O ₅ was used instead of SiO ₂ . The aspect ratio was 11.

Example 20 Columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained in the same manner as in Example 2 except that V ₂ O ₅ was used instead of SiO ₂ . The aspect ratio was 14.

Example 21 Columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained in the same manner as in Example 3 except that V ₂ O ₅ was used instead of SiO ₂ . The aspect ratio was 15.

Example 22 Columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained in the same manner as in Example 4 except that V ₂ O ₅ was used instead of SiO ₂ . The aspect ratio was 10.

Example 23 Columnar (Zr _0.75 Sn _0.25 ) TiO ₄ particles were obtained in the same manner as in Example 5 except that V ₂ O ₅ was used instead of SiO ₂ . The aspect ratio was 15.

Example 24 Columnar (Zr _0.85 Sn _0.15 ) TiO ₄ particles were obtained in the same manner as in Example 6 except that V ₂ O ₅ was used instead of SiO ₂ . The aspect ratio was 10.

Example 25 Example 1 except that NiO was used instead of SiO _2.
Columnar (Zr _0.85 Sn _0.15 ) TiO ₄ particles were obtained in the same manner as in. The aspect ratio was 10.

[0036] except using NiO in place of Example 26 SiO _2, Example 2
Columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained in the same manner as in. The aspect ratio was 12.

Example 27 Example 3 except that NiO was used instead of SiO _2.
Columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained in the same manner as in. The aspect ratio was 16.

Example 28 A columnar (Zr _0.8) was prepared in the same manner as in Example 4 except that 37.5 mg of NiO was used instead of 50 mg of SiO _2.
Sn _0.2 ) TiO ₄ particles were obtained. The aspect ratio was 11.

Example 29 Example 5 except that NiO was used instead of SiO _2.
Columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained in the same manner as in. The aspect ratio was 16.

Example 30 Columnar (Zr _0.75) was prepared in the same manner as in Example 6 except that 37.5 mg of NiO was used instead of 50 mg of SiO _2.
Sn _0.25 ) TiO ₄ particles were obtained. The aspect ratio was 11.

Example 31 11.8 g of ZrO ₂ powder, 3.6 g of SnO ₂ powder, and 9.6 g of TiO ₂ powder having a basic composition, 38 g of NaCl as a flux, and 12.5 mg of SiO ₂ ;
27.5 mg of NiO was pulverized and mixed for 1 hour with a raker. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours. After cooling, boiling washing with water was repeated, filtration was performed to separate the flux, and drying was performed at 80 ° C. for 12 hours to obtain columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles. The aspect ratio was 14.

Example 32 11.8 g of ZrO ₂ powder, 3.6 g of SnO ₂ powder, and 9.6 g of TiO ₂ powder having a basic composition, 8 g of NaCl as a flux, 30 g of Na ₂ SO ₄ , and Si.
O _{2 (} 25 mg) and Bi ₂ O _{3 (} 25 mg) were pulverized and mixed with a muller for 1 hour. Put this in an alumina crucible 1225
It was baked at 10 ° C for 10 hours. After cooling, boiling washing with water was repeated, filtration was performed to separate the flux, and drying was performed at 80 ° C. for 12 hours to obtain columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles. The aspect ratio was 16.

Example 33 11.8 g of ZrO ₂ powder, 3.6 g of SnO ₂ powder, and 9.6 g of TiO ₂ powder having a basic composition, 8 g of NaCl as a flux, 30 g of Na ₂ SO ₄ , and Si.
O _{2 (} 12.5 mg) and Cr ₂ O _{3 (} 12.5 mg) were pulverized and mixed for 1 hour with a muller. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours. After cooling, repeat boiling and washing with water, then filter to separate from flux and
Columnar (Zr _0.8 Sn _0.2 ) TiO 2 after drying for 12 hours.
₄ particles were obtained. The aspect ratio was 18.

Example 34 11.8 g of ZrO ₂ powder, 3.6 g of SnO ₂ powder, and 9.6 g of TiO ₂ powder having a basic composition, 8 g of NaCl as a flux, 30 g of Na ₂ SO ₄ , and Ni.
O 17.5 mg and Cr ₂ O ₃ 25 mg were pulverized and mixed for 1 hour with a muller. Put this in an alumina crucible 12
It was baked at 25 ° C. for 10 hours. After cooling, boil and wash with water repeatedly, then filter to separate from flux and
After drying for 2 hours, columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained. The aspect ratio was 19.

Example 35 11.8 g of ZrO ₂ powder, 3.6 g of SnO ₂ powder and 9.6 g of TiO ₂ powder having a basic composition, 8 g of NaCl as a flux, 30 g of Na ₂ SO ₄ and further Bi.
₂ O _{3 (} 25 mg) and NiO (17.5 mg) were crushed and mixed for 1 hour with a muller. Put this in an alumina crucible 12
It was baked at 25 ° C. for 10 hours. After cooling, boil and wash with water repeatedly, then filter to separate from flux and
After drying for 2 hours, columnar (Zr _0.8 Sn _0.2 ) TiO ₄ particles were obtained. The aspect ratio was 18.

Example 36 ZrO ₂ powder having a basic composition of 11.8 g, SnO ₂ powder of 3.6 g, and TiO ₂ powder of 9.6 g, NaCl as a flux of 8 g, Na ₂ SO _{4 of} 30 g and Bi were further added.
₂ O ₃ 50 mg, and 1 hour ground and mixed Cr ₂ O ₃ 12.5 mg in kneader. Put this in an alumina crucible 1
It was baked at 225 ° C for 10 hours. After cooling and repeated boiling and washing with water, it was filtered to separate from the flux and dried at 80 ° C. for 12 hours to form columnar (Zr _0.8 Sn _0.2 ) TiO ₄
The particles were obtained. The aspect ratio was 17.

Example 37 ZrO ₂ powder having a basic composition of 11.8 g, SnO ₂ powder of 3.6 g, and TiO ₂ powder of 9.6 g, NaCl of 8 g as flux, Na ₂ SO _{4 of} 30 g, and Si.
O ₂ 12.5 mg, Bi ₂ O ₃ 25 mg, V ₂ O ₅ 1
2.5 mg was crushed and mixed for 1 hour with a raker. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours.
After cooling and repeated boiling and washing with water, it was filtered to separate from the flux and dried at 80 ° C. for 12 hours to give a columnar (Zr
_0.8 Sn _0.2 ) TiO ₄ particles were obtained. Aspect ratio is 1
It was 7.

Example 38 11.0 g of ZrO ₂ powder having a basic composition, 4.5 g of SnO ₂ powder, and 9.5 g of TiO ₂ powder, 8 g of NaCl as flux, 30 g of Na ₂ SO ₄ , and further Si.
25 mg of O _{2 and} 25 mg of V ₂ O ₅ were pulverized and mixed for 1 hour with a muller. Put this in an alumina crucible at 1225
It was baked for 10 hours. After cooling, boiling washing with water was repeated, filtration was performed to separate the flux, and drying was performed at 80 ° C. for 12 hours to obtain columnar (Zr _0.75 Sn _0.25 ) TiO ₄ particles. The aspect ratio was 17.

Example 39 ZrO ₂ powder having a basic composition of 12.6 g, SnO ₂ powder 2.7 g, and TiO ₂ powder 9.6 g, NaCl as a flux 8 g, Na ₂ SO ₄ 30 g, and Bi.
₂ O _{3 (} 44 mg) and V ₂ O _{5 (} 12.5 mg) were pulverized and mixed for 1 hour with a muller. Put this in an alumina crucible 12
It was baked at 25 ° C. for 10 hours. After cooling, boil and wash with water repeatedly, then filter to separate from flux and
After drying for 2 hours, columnar (Zr _0.85 Sn _0.15 ) TiO ₄ particles were obtained. The aspect ratio was 18.

Example 40 ZrO ₂ powder having a basic composition of 12.6 g, SnO ₂ powder of 2.7 g, and TiO ₂ powder of 9.6 g, NaCl as a flux of 8 g, Na ₂ SO _{4 of} 30 g, and Si.
O ₂ 12.5 mg, Cr ₂ O ₃ 12.5 mg, V ₂ O ₅
12.5 mg was crushed and mixed for 1 hour with a raker. This was placed in an alumina crucible and fired at 1225 ° C. for 10 hours. After cooling, boiling washing with water was repeated, filtration was performed to separate the flux, and drying was performed at 80 ° C. for 12 hours to obtain columnar (Zr _0.85 Sn _0.15 ) TiO ₄ particles. The aspect ratio was 18.

[0051]

The columnar particles obtained by the present invention have a large aspect ratio and are useful for the synthesis of oriented dielectric ceramics and the synthesis of composite materials having anisotropy of characteristics.

Claims (2)

[Claims] 1. The basic composition is xZrO ₂ —ySnO ₂
-ZTiO ₂ (however, 0.6 ≦ x ≦ 1.0, 0 ≦ y ≦
0.4 and 0.8 ≦ z ≦ 1.2. ) And having an aspect ratio of 10 or more. 2. The basic composition is xZrO ₂ —ySnO ₂
-ZTiO ₂ (however, 0.6 ≦ x ≦ 1.0, 0 ≦ y ≦
0.4 and 0.8 ≦ z ≦ 1.2. ), With respect to this basic composition, SiO ₂ , Bi ₂ O ₃ , Cr ₂ O ₃ , V
_A method for producing columnar particles, characterized in that at least one compound selected from the group consisting of ₂ O ₅ and NiO is added to a flux and fired.