JPS63288962A - Production of (pb, sr) (zr, ti)o3 - 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] [Industrial Application Field] The present invention has a general formula (Pbl-X 5ry) (Zr, -
y Tjy)O+(0<X<0.3 0≦y<1.0)
(Pb, Sr) (Zr, Ti)O
+ (hereinafter referred to as PSZT).

Since PSZT has an electro-optic effect similar to that of PLZT and also has translucency, it can be expected to find a wide range of applications as opto-ceramics such as polarizing elements, optical shutters, and image storage elements.

[Conventional technology]

Among the constituent components of PSZT, zirconia raw powder is extremely likely to agglomerate and form relatively large secondary particles. Using this kind of zirconia raw material powder, mixing it and performing PS using a dry method.
Even if the ZT raw material powder is created, the average particle size will be 1 to 2 μm or more. Even if a PSZT raw material powder with a particle size of this size is used, the reduction in porosity during firing is insufficient, and therefore it is difficult to obtain a PSZT fired body with high density, high translucency, and optical uniformity.

Further, in order to produce a high-density sintered body, a molding method such as hot pressing or HIP is employed, but it is difficult to obtain high-density PSZT even if hot pressing or the like is applied to the raw material powder.

[Problem that the invention seeks to solve]

The present invention was made in order to eliminate the drawbacks in the dry synthesis of PSZT, and its purpose is to create a submicron grade modified zirconia raw material powder with good dispersibility,
A method of synthesizing easily sinterable and high bulk density PSZT powder by a simple dry method using the powder, and further sintering this powder to produce optically uniform PSZT with high density and high transparency. Our goal is to provide the following.

[Means for solving problems]

As a result of intensive research in order to achieve the above object, the present inventors found that the general formula (Pb+-x 5ry) (Zr+-y Tiy)
Oz, 0 < x 10, 3.0 < y 1.0. In the process of producing PSZT by the dry method shown in Agglomeration of the contained particles becomes less likely to occur, and then drying is performed to obtain a
It was revealed that when calcined at 00°C, it is possible to form submicron-sized powder (modified zirconia powder) with extremely little agglomeration. If this powder is used as a raw material and the remaining constituent compounds of the desired PSZT composition are mixed by a dry method, a raw material powder with excellent submicron powder properties can be easily obtained, and the raw material powder can be molded. When sintered, PSZ can be produced with extremely high density, high translucency, and optical uniformity even if operations such as hot pressing and HTP (hot gas pressure sintering) are omitted.
It was found that T can be easily obtained. The present invention was completed based on this knowledge.

The gist of the present invention lies in the combination of the following three steps.

(1) At least one metal component other than zirconium constituting PSZT is selected in an appropriate amount sufficient to suppress agglomeration of the coprecipitate, and is reacted with a solution containing zirconium and a precipitate forming liquid to form a coprecipitate, 700-1300℃ after drying
This process avoids the agglomeration of PZ.
Modified zirconia is produced which can also be used for T, ZT, etc.

(2) The calcined product obtained in the step (1) and the desired P
500 by mixing the remaining constituent compounds of the SZT composition.
Step of calcination at ~1300°C; in this step, the desired compound composition is obtained by adding the remaining components.

(3) The obtained calcined powder is molded to a size of 1000 to 1300
A method for producing PSZT, characterized by comprising the steps of sintering at ℃.

Examples of compounds for creating the zirconium solution include zirconium oxychloride, zirconium oxynitrate, zirconium chloride, zirconium oxynitrate, zirconium chloride, and zirconium nitrate.

As a solvent for the zirconium solution, filtered water or alcohol is used in which the above compound is dissolved. All of the above compounds are soluble in water; zirconium oxychloride, zirconium chloride and titanium tetrachloride are soluble in ethanol. Furthermore, in order to prepare a zirconium solution, metal zirconium can be dissolved in aqua regia or HF.

Examples of compounds for preparing a solution containing at least one component other than zirconium include Pb(NO:+)z for lead, 5r(NOs)z for strontium, and Ti(NOs) for titanium.
3) a.

Examples include Ti(J and Ti(SO4)z.Water or alcohol is used as the solvent for this solution.The zirconium solution and the solutions other than zirconium may be prepared separately, or each compound may be prepared in the same solvent. It may also be adjusted by dissolving.

Examples of reagents for preparing the precipitate-forming solution include organic reagents such as ammonia, ammonium carbonate, caustic alkali, oxalic acid, ammonium oxalate, amines, and oxine. The precipitate formation reaction can be carried out at room temperature.

The coprecipitate is in a sol or slurry state. The coprecipitate is recovered by filtration and washing.

The types and amounts of the PSZT components to be dissolved in the zirconium-containing solution are preferably such that the addition of the components can effectively suppress aggregation of the zirconia powder finally obtained. The calcination temperature of the obtained coprecipitate was 700~
The temperature is 1300°C. If the temperature is lower than 700°C, significant aggregation will occur, and if the temperature exceeds 1300°C, particles will tend to become coarse. To the thus obtained mixture, the remaining components other than zirconium are added and mixed. Of course, it is also necessary to replenish the missing components added to zirconia. In this case, the particle size of any compound powder (mainly oxide) used is submicron class. However, even if lead oxide powder with a coarse particle size is used, it will hardly affect the properties of the resulting PSZT powder.

The calcination temperature of these mixtures is 500 to 1300 when containing Ti, when containing Sr, and when containing Ti and Sr.
Varies significantly over the °C range. In short, the temperature must be above the minimum temperature at which the solid phase reaction is almost or completely completed, and within the maximum temperature range at which significant grain growth does not occur.

The powder thus obtained is molded. The sintering temperature, like the calcination temperature of the mixture described above, varies depending on the types of constituent components, but is generally in the range of 1000 to 1300°C. If it is lower than 1000°C, sintering is insufficient and high density cannot be obtained, and if it exceeds 1300°C, the particles become coarse or the volatilization of PB is promoted.

・Example 1 Titanium tetrachloride aqueous solution (0.8 mol/l concentration) 40.0
cc and zirconium oxynitrate aqueous solution (0.8mot/
1f1 degree) 160.0cc was mixed. The mixed aqueous solution was gradually added to stirring 6N ammonia water 11 to obtain a hydroxide coprecipitate of TB4+ and Zr''. After washing and drying the coprecipitate, it was heated at 1100°C. Calculate (Zro)
, s Tia, z) Oz powder was created.

The average particle size of the powder was 0.32 μm.

The powder 1B, 329gr and commercially available T+otm powder 1.4
14gr, pbo powder (average particle size 151! m) 31
．． 74gr and 3.678gr of SrO fine powder were mixed in a ball mill for a day and night, and then calcined at 850°C for 2 hours (Pbo, s Sro, z) (Zr2.?!Tio,
zs) Os powder was obtained. The average particle size of the powder is 0.33μ
It was m. A tablet formed by molding the powder at 1 ton/cd was heated at 1150 liters in an atmosphere coexisting with lead vapor and oxygen gas.
It was sintered at ℃ for 10 hours. The density of the obtained sintered body is 7.6
9, and the light transmittance was about 44% using a wavelength of 600 nm and a sample thickness of 2.5 nm.

・Example 2 Titanium tetrachloride aqueous solution (0.8 mol/l concentration) 40.0
0cc, strontium nitrate aqueous solution (0.8mol/
I! concentration) 44.444cc and zirconium oxynitrate aqueous solution (0.8mol/1 concentration) 160.0Oc
c was mixed. The mixed aqueous solution was gradually added to 6N ammonia water 1β being stirred, and Sr"" and Ti4
A hydroxide coprecipitate of Zr and Zr was obtained. The coprecipitate was washed,
After drying, it is calcined at 1100℃ to form Sro, z(Zr+
, II Tio, z)o, 90z powder was created.

The average particle size of the powder was 0.22 μm.

22.013 gr of said powder and 1.4 g of commercially available Ti1t fine powder
14 gr and pbo powder (average particle size 15 p rr,)
After mixing with 31.74 gr in a ball mill for a day and night, 8
Calcinate at 50℃ for 2 hours (Pbo, s Sro, 2
) (Zro, ff! Tio, zs) Oz powder was obtained.

The average particle size of the powder was 0.39 μm. l of the powder
The tablet molded with ton/ctA was sintered at 1150° C. for 10 hours in an atmosphere coexisting with lead vapor and oxygen gas.

The density of the obtained product reaches 7.68, and the transmittance is at wavelength 6
00 nm was used, and the sample thickness was 37% when the sample thickness was 2.5 mm.

・Example 3 Strontium nitrate aqueous solution (0.8 mol/ltM degrees)
44.444cc and zirconium oxynitrate aqueous solution (0
,8mol/j! Concentration) 160.00 was mixed. The mixed aqueous solution was gradually added to stirring 6N ammonia water B to obtain a hydroxide coprecipitate of Sr" and z r 4 +. After washing and drying the coprecipitate, , 1100'C
The powder was calcined to obtain Sro, z Zro, tz Ol, and ha powders.

The average particle size of the powder was 0.26 μm.

This powder 19.456gr and commercially available Ti0z fine powder 3.9gr
71gr and pbo powder (average particle size 15 pm) 31
．． After mixing with 74gr in a ball mill for a day and night, 850gr.
Calcined at ℃ for 2 hours (Pbo, s Sro, z)
(Zro, qt Tie, za) Oz powder was obtained.

The average particle size of the powder was 0.38 μm. 1 of the powder
The tablets molded at ton/cd were sintered at 1150° C. for 10 hours in an atmosphere containing lead vapor and oxygen gas.

The density of the obtained product reaches 7.69, and the transmittance is at wavelength 6
Approximately 36% when using 00nm and sample thickness of 2.5mm
Met.

・Comparative example Commercially available PbO+ TtOz, Zr0z, SrO powder (Pbo, s Sra, z) (Zro, tz
The composition was blended to have a composition of Ti0-ze)O+, mixed all day and night in a ball mill, and then calcined at 900°C for 2 hours. The powder was molded at 1 ton/- and sintered under the same conditions as in Examples 1 and 2.3.

Although the density of the obtained PSZT was about 7.6, it did not become a transparent sintered body. The average particle size of the powder during calcination was 4.5 μm.

〔Effect of the invention〕

According to the method of the present invention, the zirconia powder (modified zirconia powder) containing one or more types of PSZT components in the first step can be made into submicron particles with extremely few secondary particles, and by using this, Thereafter, by a simple dry method, submicron grade PSZT raw material powder can be easily obtained, and furthermore, PSZT with good translucency and high density can be obtained using this as a raw material, which is an excellent effect. In addition, the following effects can also be achieved.

1) Since the modified zirconia powder obtained by calcining is sufficiently dispersed, it can be supplied as a raw material powder without the need for a particular pulverization step of the calcined product.

2) P obtained from the calcined modified zirconia powder by a dry method
SZT powder is also obtained in a monodisperse state, and therefore has sufficient sinterability and high density even without the pulverization step.

3) PSZT for optoelectronics, which requires extremely high density and optical uniformity, can be reduced to theoretical density by simple solid phase sintering, omitting operations such as hot pressing and HIP (hot gas pressure sintering). can be obtained at extremely high densities.

4) PSZT of any composition can be supplied at extremely low cost by producing modified zirconia powder with excellent powder properties in large quantities.

Claims (1)

[Claims] 1. (1) General formula (Pb_1_-_xSr_y) (Zr
_1_-_yTi_y)O_3(0<x≦0.3 0≦
y≦1.0) (Pb, Br) (Zr, Ti)
A step of reacting an appropriate amount of at least one metal component of O_3 with a solution containing zirconium and a precipitate forming liquid to form a coprecipitate, and calcining the coprecipitate at 700 to 1300 ° C. after drying. 2) The calcined product and the target (Pb, Sr) (Zr
, a step of mixing the remaining constituent compounds of the Ti)O_3 composition and calcining at 500 to 1300°C, (3) molding the obtained calcined powder to a temperature of 1000 to 1300°C.
It is characterized by a step of sintering at ℃ (Pb, S
r) Method for producing (Zr, Ti)O_3.