JPS60141674A - Manufacture of light permeable high dielectric ceramic - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Field of Application of the Invention: The present invention relates to a method for manufacturing ferroelectric porcelain (Part 2, more specifically, lead titanium zirconate porcelain (hereinafter referred to as "PZTJ") (Part 2, Part 3). The present invention relates to a method for manufacturing a three-component PZT translucent ferroelectric ceramic in which components are added and dissolved in solid solution.

Since PZT is a ferroelectric material, it is widely used in high frequency filters, transducers for audio equipment, ultrasonic generation elements, piezoelectric ignition elements, and the like. PZT +
: As the third component, Pb (M'ryu・M'ding) Os
・(Here (=, M′ is Mg, Zn, or Ni
, M' represents Nb or Ta. ) is superior to PZT in electrical properties such as dielectric constant, electromechanical coupling coefficient, and piezoelectric constant, and therefore a larger portion of piezoelectric ceramics is being occupied by ternary PZT+2.

On the other hand, dielectric ceramics with high light transmittance and high dielectric constant are electro-optic functional materials that are expected to be applied to many fields such as optical memories, optical shutters, and display devices.

Conventional technology: Conventionally, ferroelectric porcelain (hereinafter referred to as "PLZT J
It is called. ) is known, and its manufacturing method, modification method,
In addition, many documents and patents have been reported in terms of application ('''-).However, in PLZT, the composition range in which it exhibits good translucency and the composition range in which it exhibits good electrical properties do not match; For applications such as transparent piezoelectric buzzers and transparent piezoelectric speakers, it is not always possible to obtain sufficient performance.As a translucent ferroconductor porcelain other than PLZT, Ceramics for Enctronics, pp. 247-253 (Co., Ltd. CM Publishing, 1981) -2, Rare earth elements such as La and/or Nb, Ta, Sb
It has been reported that a ZT-based sintered body with metals such as the following was manufactured by a hot pressing method. However, the hot press method is adopted as an industrial manufacturing method because the equipment is complicated and it is not suitable for mass production of large sintered bodies (the second method has problems).

On the other hand, three-component PZT can be obtained by adjusting the composition ratio of the third component and the amount of solid solution for PZT (2).
However, it is possible to manufacture sintered bodies using ceramic powder obtained by high-temperature solid-phase reaction of oxides of each metal component, which is a common manufacturing method for sintered bodies. It is extremely difficult to produce a high-density sintered body that exhibits translucency, and to date, there have been no reports of obtaining a translucent sintered body of ternary PZT. .

Problems to be Solved by the Invention: An object of the present invention is to provide a method for producing a translucent three-component PZT.

Means for Solving Problems: The present invention provides a ceramic powder obtained by decomposing or hydrolyzing a lead-containing composite metal oxide precursor composition represented by the following composition formula (1) % formula % (1) This is a method for producing translucent ferroelectric porcelain, which is characterized by press-molding the lower right C2 in the presence or absence of a binder, and sintering the obtained molded body.

In the present invention (2), the lead-containing composite metal oxide precursor composition represented by the compositional formula (1) is disclosed in Japanese Patent Application No. 57-1
No. 52739 C: This is a composition for which a patent application has been filed, and is represented by the following general formula (2) (where, M and R have the same meanings as above). An organic titanium compound and an organic zirconium compound, and an organic lead compound represented by the following general formula (3) (where 2 and R' have the same meanings as above), magnesium, By reacting in the presence of an organic acid salt of zinc or nickel and niobium alkoxide or tantalum alkoxide, the reaction can be easily carried out four times.

In the present invention, the composition is thermally decomposed or hydrolyzed to produce a ceramic powder containing a metal component having the same composition ratio as the metal component added during production of the composition. Next, the obtained ceramic powder is pressure-molded in the presence or absence of a binder by a normal pressure-molding method such as dry press molding, isostatic press molding, etc. to produce a molded body. Sinter the molded body at a temperature of 1100 to 1300℃
, preferably 1150-1250°C, sintering time 1-10
Translucent three-component PZT can be produced by sintering under sintering conditions of 0 hours, preferably 10 to 50 hours. The sintering method is the method used in general PZT production, for example, in a magnesia crucible with a lid (
= The molded body was put together with powder for atmosphere adjustment (two people put a lid on it,
It is possible to adopt a method in which this magnesia crucible is heated to a sintering temperature in a sintering furnace by filling a larger crucible with alumina powder, etc., and covering the crucible with a lid.

Effect: In the present invention, the lead-containing composite metal oxide precursor composition represented by the compositional formula (1) is a solution-based composition having a stoichiometrically uniform composition, and it is difficult to decompose it. The resulting ceramic powder also has a stoichiometric (=uniform composition).Therefore, the ternary PZT obtained by molding and sintering the ceramic powder also has a stoichiometric (=uniform composition) has.

The present invention (2) thermally decomposing or hydrolyzing the composition represented by the above-mentioned compositional formula (1) (2) the secondary particle size is 0.1 to 0.5 μm; 5-1.
13wt of particles with an extremely low degree of aggregation of 5μm and a particle size distribution expressed as a cumulative percentage of aggregated particles of 0.4μm or less
It is possible to produce a uniform ceramic powder with an extremely narrow particle size distribution in which particles of 1 μm or less are 37 wt % or less. Decomposition of the composition represented by the composition formula (1) is as follows.

Hydrolysis is preferable to thermal decomposition because it can produce ceramic powder with a smaller aggregated particle size and a narrower particle size distribution. For example, the composition is dissolved in an organic solvent such as an alcohol solvent such as methanol, ethanol, impropatol, or butanol, an Ml group solvent such as benzene, toluene, or xylene, or a hydrocarbon solvent such as heptane or hexane, At a temperature below the boiling point of the organic solvent used, preferably at a temperature below 200°C (
=, Hydrolysis is carried out by adding water dropwise. After drying, the powder obtained from hydrolysis (2) is calcined by heating at a temperature of 400° C. or higher in an oxygen stream (ceramic powder is obtained from 2).

The ceramic powder produced by the method described above has a uniform composition, a small secondary particle size, and particles with a low degree of aggregation and a narrow particle size distribution, all of which work synergistically, resulting in extremely high surface activity. Therefore, the sinterability is extremely excellent.

In the present invention (-), using a ceramic powder with excellent sinterability obtained by the above method (2) using a conventional method (2) using a general pressureless sintering method to form a molded body under pressure, However, even if the relative density is 987) or more, a high-density sintered body, that is, a ternary-component PZT can be produced.

This three-component PZT has a high density, so even though it was polished to a thickness of 0.2 nm, it has translucency with a linear transmittance of 10% or more for light at a wavelength of 6001 m. If the sintering temperature of the molded body is less than 1100° C., even if sintered for a long time, sintering will be insufficient or insufficient, and the density of the sintered body will not increase, and therefore only a sintered body with low light transmittance will be obtained. Also, 1
If the temperature exceeds 300°C, it is not preferable because it becomes difficult to control the amount of PbO evaporated and extracted even if the composition of the atmosphere adjusting powder is controlled. In particular, sintering in the range of 1150 to 1250' is preferable because a highly translucent sintered body can be obtained.

In the present invention C2, the starting raw materials and each processing step act synergistically (two times) to produce a 3-component PZT having a stoichiometric (=uniform composition, high density, and high transparency). Furthermore, the electrical properties of the resulting three-component PZT satisfy the desired properties.

Examples and Comparative Examples: Below (2) The present invention will be explained in more detail from Examples and Comparative Example C2. However, the scope of the present invention is not equally limited by the following Examples. .

Example 1 (1) Production of ceramic powder 1000 m with thermometer, reflux condenser, and stirrer
l four-roof flask (:, in order to compensate for the evaporation and loss of pbo during sintering, the stoichiometric ratio (2 vs. 7 mo1% excess (=
Corresponding Pb (OCOCH3)2: 174. O,
! i' (0,535 mol), Mg (OCOCH,)
2: 2.96g (0,0208 mol), Ti (on
-04,! no) 4.9g (0,220 mol),
Zr (OnQHt)4:83.5.9 (0,218
mole) and Nb(OCOH3)a: 19.1 g (0
, 0417 mol) and P-xylene as a solvent:
300.9 was added, and the temperature was raised while stirring under N2 atmosphere. At a reaction temperature of about 130° C., butanol and butyl acetate began to distill out, and the reaction solution changed from its initial cloudy state to a yellow-brown, uniform, transparent solution. The solvent was distilled off from this solution until the oxide of the metal component contained therein (= converted concentration was 40 wt%) to obtain a lead-containing composite metal oxide precursor composition.

The obtained lead-containing composite metal oxide precursor composition was placed in a 3,000 ml four-bottle flask (two preparations, n -Cj%OH as a solvent: 2,500 m
1, and while stirring vigorously, add water: 38I! from a microsyringe. was added dropwise over 1 hour, and then the solvent was distilled off using a rotary evaporator to obtain a dry powder. The obtained dry powder was calcined in an oxygen stream at a temperature of 650°C + two airs to obtain 0.435PbZrOa-0,44PbTi03-0.
Ceramic powder 162.0.9 having a composition of 125Pb(Mg7Nb-H)03 was obtained. The X-ray diffraction pattern of the obtained ceramic powder is shown in Figure 1, using a centrifugal sedimentation type particle size distribution analyzer (
Figure 3 (A) (= shows the particle size distribution measured using SA-CF2 model manufactured by Ryotsu Manufacturing Co., Ltd.). Figure 1 shows that the obtained ceramic powder is a perovskite cubic crystal. Figure (3) (= As shown, the obtained ceramic powder has a small average particle diameter of 0.83 μm, which represents 50% of the cumulative weight percentage, and 90% of the cumulative weight percentage.
The ratio of the particle size showing 10% to the particle size showing 10% D9G/DI (
It is a powder with extremely uniform particle size, and the particle size distribution expressed by l is as small as 10.1.

(2) Production of molded body 3 g of the ceramic powder obtained in the above process was pressure molded under a pressure of 2 tA to form a disk-shaped molded body with a diameter of 20 mm and a thickness of 2 mm. The dimensional density of the obtained molded body was 4.7
It was 9/rd.

(3) Production of three-component PZT (sintering of molded body) The molded body obtained in the above step was placed in a magnesia crucible (with a small amount of PbO powder as a bi-atmosphere conditioner (two people, covered with a lid). History (in two large alumina crucibles (two people covered the surrounding area with alumina powder, put a lid on and put it in a sintering furnace (two people) at a temperature of 1250℃ for 3
Sintering was performed while holding for 0 hours to obtain three-component PZT.

The X-ray diffraction diagram of the obtained 3-component PZT is shown in Figure 2. The density of the obtained 3-component PZT measured by the Archimedes method was 7.91/i, and the relative density was 98.0. %
(There were two in a row.

The obtained three-component PZT was polished to a thickness of Q and 2 mg, and the linear transmittance of light with a wavelength of 600 nm was measured using a spectrophotometer (
Measured using Hitachi's new model 100-40).

Ceramic powders produced in the same lot were molded under the same pressure conditions and sintered under the same conditions to create a 3-component PZT disc with a diameter of 15 mm and a thickness of 1 inch. As a result of baking lead electrodes on the created upper and lower surfaces and using an LCft meter to measure the dielectric constant at IKHz at 25°C, g = 2.
210, tz-δ=0.021. Then,
This sample was placed in silicone oil at 100℃ for 40 minutes.
After polarization treatment was performed by applying a direct current branch field of KVα for 30 minutes, aging was carried out for 24 hours. The piezoelectric properties of this sample were measured using the resonance anti-resonance method (kp=0.62
2, Qm=91, and impedance Zr=32Ω at the resonant frequency.

Example 2 The ceramic powder produced in Example 1 was
Pressure is applied to form the product to a diameter of 2Qmmφ and a thickness of 5mm.
A molded body was created. This molded body was heated at 1200°C x 20
It was sintered by the hot press method under the conditions of 0 KP/i, and had a tri-dimensionality of 8.051 M. Thickness 0.2 mU (2nd polishing, 6
As a result of measuring the linear transmittance of light with a wavelength of 00 nm, 20
%Met.

Example 3 The same equipment as used in Example 1 (2. In order to compensate for the volatilization of PbO during sintering, Pb(OCOCHs) t'174 was added in an excess of 7 mol% over the stoichiometric ratio. .O
g (0,535 mol), N1(OCOCHs)2:
14.739 (0,1,67 mol), Ti(On
C, H, )<: 59.56g (0,175mo/L/
), Zr(On C4H@)42213.78
g (0,075 mol) and Nb (On C.

Ho)s'152.5& (0,333 mol) was added,
Hereinafter, in the same manner as in Example 1 (=processed, 0.15PbZrO, -0,35PbTf 03-0.
50Pb(Ni, -Nb,)O.

Ceramic powder with the composition was obtained. The X-ray diffraction pattern of the obtained ceramic powder is shown in Figure 4 (1), and the particle size distribution measured in the same manner as in Example 1 is shown in Figure 6 (5) (2).

The obtained ceramic powder was molded under a pressure of 2 t/i to obtain a disc-shaped molded body with a diameter of 20 m and a thickness of 3 m, and this molded body was sintered in the same manner as in Example 1 to form Component system PZT
I got it. The X-ray diffraction pattern of the resulting three-component PZT is shown in Figure 5 (2).The density measured by the Archimedes method is 8.15 g/al, which is a relative density of 98%, and 0.2
The transmittance of light at a wavelength of 600 mm was 44% after polishing to a thickness of 11111.

The dielectric properties measured in the same manner as in Example 1 were ε=40
50. mδ=0.029, and the piezoelectric property is kp=
The impedance at the resonant frequency was 0.625°Qm −21, Zr = 430.

Comparative Example 1 Example 1 (=, changing the hydrolysis conditions was 11
．． Ceramic powder having the same composition as in Example 6 was manufactured. As a result of X-ray diffraction, the obtained ceramic powder was found to have perovskite cubic crystals as in Example 1. The particle size distribution of the ceramic powder is shown in FIG. 3 (B).

Using the obtained ceramic powder, a press molded body (dimensional density 4.51 glcr!) was produced under the same conditions as in Example 1, and sintered under the same conditions as in Example 1.
I got it.

The density of the obtained three-component PZT measured by the Archimedes method was 7.68 g/i, and although it was polished twice to a thickness of 0.2 mm, the linear transmittance of light at a wavelength of 600 mm was 3%. .

Comparative Example 2 In order to compensate for the volatilization of PbO during sintering, PbO: 119.4 g (
0,535 mol), MgO: 0.84 g (0,02
08 mol).

TiO2: 17.58g (0,220mol), Zr
O,, :26.8. ! i' (0,218 mol) and N
b2O, :5.54. ! i+ (10,0208 mol) was mixed and pulverized in a ball mill (two people) in an acetone solvent for 48 hours, then the solvent was distilled off and dried, and then in an oxygen stream (two people were held at a temperature of 750°C for 3 hours). The mixture was calcined to obtain ceramic powder.

As a result of X-ray diffraction of the obtained ceramic powder, PbZr
0. was confirmed to remain. The X-ray diffraction diagram is shown in FIG. The obtained ceramic powder has an average particle size of 4
．． The 10 μm2 particle size distribution Doo/D+o was 8.0. The particle size distribution is shown in Figure 3 (Cal 2).

This ceramic powder was pressure-molded under the same conditions as in Example 1 to obtain a compact with a dimensional density If of 5.389/cd.

The obtained molded body was then sintered under the same conditions as in Example 1 to obtain a sintered body. The density of the obtained sintered body measured by the Archimedes method was 7.6 g/m, which is a relative density of 94%. Also, 0.211m + = 600m after polishing
The transmittance of light at mm wavelength was 1% or less.

The dielectric properties measured in the same manner as in Example 1 were as follows: g=15
3Q, tan δ = 0.025, and the piezoelectric characteristics are kp =
0.571°Qm=160, Zr=26G.

Comparative Example 3 By changing the hydrolysis conditions in Example 3, the average particle diameter was 1.20, and the particle size distribution was Doo/D+.

A ceramic powder having the same composition as in Example 3 with 10.3 was obtained. The particle size distribution of the obtained ceramic powder is shown in Figure 6 (B
) +: Show.

The obtained ceramic powder was pressure-molded under the same conditions as in Example 3, and a compact having a dimensional density of 5.0117 crI was obtained. This molded body was then sintered under the same conditions as in Example 3 to obtain a three-component PZT. The resulting three-component PZT had a density of 8.0591 crd (according to the Archimedes method), and a transmittance of light at a wavelength of 600 mm was 8% when polished to a thickness of Q, 2rnrn.

Comparative Example 4 To compensate for the volatilization of PbO during sintering, 119.4 g (0,
535 mol), NiO: 12.45 g (0,1667
mole).

Nb2O5: 44.30. ! i' (0,1667 mol), TiO□: 13.98.9 (0,175 mol) and ZrO: 9.24N (0,075 mol),
After mixing and pulverizing in a ball mill (by two people) in an acetone solvent for 48 hours, the solvent was distilled off and dried, and then calcined in an oxygen stream at 750° C. for 3 hours to obtain a ceramic powder.

As a result of X-ray diffraction, the obtained ceramic powder was found to have P'bO
, residual ZrO2 was confirmed. The obtained ceramic powder has an average particle size of 36 μm and a particle size distribution of Dヮ/D+o.
was 8.6. The particle size distribution of the ceramic powder is shown in FIG. 6(C).

The obtained ceramic powder was pressure-molded under the same conditions as in Example 3 to obtain a compact with a dimensional density of 5.20 g/cd.

Next, this molded body was sintered under the same conditions as in Example 3 to obtain a sintered body. The density of the obtained sintered body according to the Archimedes method (l-) is 7.729/i (relative density 93%),
The transmittance of light at a wavelength of 00 nm was 1% or less when polished to a thickness of 02 mm.

In addition, the dielectric properties measured in the same manner as in Example 3 were ε
-3840, tan δ = 0.025, and the piezoelectric property is kp = 0.585. Qfn=32. Zr=36
It was Ω.

Effect of the invention: In the present invention, by using a lead-containing composite metal oxide precursor composition represented by the compositional formula (1) c as a starting material, a ceramic powder obtained by thermally decomposing or hydrolyzing the lead-containing composite metal oxide precursor composition, and the ceramic Three-component PZ obtained by sintering powder
T has peropnukite cubic crystals as shown in the attached Figures 1, 2, 4 and 5 (=). As shown in Example 2, both have higher dielectric and piezoelectric properties than those obtained by the conventional method of mixing oxides. The ceramic powder obtained by decomposing the material has a small average diameter and a uniform diameter of 1 to 1, so it has a cedar-like surface activity, and has excellent sinterability (= excellent, fine IM). 3
A component-based PZT can be produced. Particularly high density imparts light transmittance to the three-component PZT.

In the present invention, the lead-containing composite metal oxide precursor composition shown in compositional formula (1) is used as a starting material, and it is decomposed (with a diameter smaller than that of the other).

Furthermore, a ceramic powder with a narrow degree distribution width can be obtained, and the synergistic effect of sintering this ceramic powder makes it possible to obtain three components that have optical transparency, high density, and excellent dielectric and piezoelectric properties. A PZT system is obtained.

The present invention provides a light-transmitting three-component system P that has not been previously reported.
It provides a possible manufacturing method for the mass production of ZT (two industrial processes), and one starts from a solution-based precursor composition (second one), which is conventionally known to have translucent properties. It also suggests that a ceramic sintered body (=) that does not have translucency can be imparted with translucency, and its industrial significance is extremely large.

[Brief explanation of the drawing]

Figure 1 1 X-ray diffraction diagram of the ceramic powder obtained in Example 1 Figure 2 X-ray diffraction diagram of the ternary PZT obtained in Example 1 Figure 3 Particle size distribution curve of the ceramic powder used Horizontal axis Two particle diameters (μtrL) Vertical axis: Cumulative weight percentage (%) (8) Example 1 However) Comparative example 1 (C1 Comparative example 2 Fig. 4 Obtained in Example 3 X-ray diffraction diagram of the ceramic powder obtained in Figure 5. Axis: Particle size (μfrL) Vertical axis: Cumulative weight percentage (%) (A) Example 3 However) Comparative example 3 (C1 Comparative example 4) Figure 7 X-ray diffraction of the sintered body obtained in Comparative example 2 Figure 8 Electron micrograph of the fractured surface of the press-molded bodies obtained in Example 1 and Comparative Example 2 The white par is 10 μm. (al Example 1 (bl Comparative Example 2 Patent Applicant (430) Representative of Nippon Soda Co., Ltd.
(6286) Ito 11 Kuzuyuki (7125) Yoshimi Yokoyama Figure 1 Figure 2 ψ′ 0 Figure 3 (mlcron) Figure 4 Figure 5 LU 3Ll 4υ 50 60 70 Figure 6 (wt%) micron) Figure 7 1982 Patent Office No. 245766 25 Name of the invention Method for manufacturing translucent ferroelectric porcelain 3, Relationship with the person making the amendment Patent applicant ■ 100 2-2 Otemachi, Chiyoda-ku, Tokyo Number 1 (430
) Nippon Soda Co., Ltd. 4, Agent Bi 100, 2-2-1 Otemachi, Chiyoda-ku, Tokyo, Japan Phone: (245) 6234 6. Column 7 for a brief explanation of the drawings in the specification subject to amendment. "Electron micrographs of the fractured surfaces of the press-molded bodies obtained in Example 1 and Comparative Example 2" on page 23, lines 17 to 18 of the statement of contents of the amendment were replaced with "Example 1 and 1L Comparative Example 2""Electron micrograph showing the particle structure of the fractured surface of the press-molded product obtained in

Claims (1)

[Claims] 1. Ceramic powder obtained by thermally decomposing or hydrolyzing a lead-containing composite metal oxide precursor composition represented by the following compositional formula (1) (% formula %) in the presence of a binder. A method for manufacturing translucent ferroelectric porcelain, characterized by press molding and sintering the resulting molded body. The method described in Paragraph 1 of Patent R1, in which decomposition of a metal oxide precursor composition is carried out by hydrolysis (2). 4. The method according to claim 1, wherein the sintering temperature of the compact is 1100 to 1300°C.