JPH0336769B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing lead perovskite powder having excellent uniformity and particle size characteristics, and a sintered body thereof. In addition to promising applications, lead perovskite solid solution ceramics with high bulk density can be produced even when sintered at relatively low temperatures, and piezoelectric materials (filters, ultrasonic vibrators,
It can be widely used as functional ceramics such as resonators, various elements, actuators, dielectrics, semiconductors, optoelectronic materials, etc.

[Prior art] It is already known that lead perovskite solid solution sintered bodies have excellent properties as functional ceramics as described above, but recently the application fields of functional ceramics have further expanded and the application technology has expanded. As the sophistication of ceramics progresses, the required characteristics for ceramics are also becoming more severe. Since the biggest influence on the performance of ceramics is the properties (particularly particle size characteristics) of the raw material powder (calcined raw material powder, hereinafter the same), various improvement studies are being carried out on the manufacturing method of raw material powder. There is.

By the way, dry methods and wet co-precipitation methods are known as methods for producing lead perovskite solid solution powder.

The dry method is a method that has been widely used industrially for a long time, and is a method in which powders of constituent raw materials are dry mixed and calcined. It is difficult to obtain
Therefore, high-temperature calcination is required in order to efficiently promote the reaction between the raw material components, and as a result, the raw material powder partially aggregates and becomes coarse grains, which in turn reduces sintering properties and causes problems after sintering. There is a drawback that the bulk density cannot be sufficiently increased.

On the other hand, the wet co-precipitation method involves creating a mixed solution of soluble metal compounds (sulfate, oxynitrate, acetate, etc.) that are the raw materials for the constituent metal components, adding a precipitant such as an alkali to the solution, and hydrating it. This method involves co-precipitation as a product, followed by filtration, drying, and calcining. With this method, a mixed powder with high uniformity can be obtained. However, it has been pointed out that this method has the drawback that particles aggregate during precipitation, drying, or calcination to form coarse secondary particles, which also reduces sinterability. Furthermore, in the case of the wet co-precipitation method, the precipitate forming ability of each component is not necessarily constant; for example, 100% of a certain component may precipitate from soluble compounds, but only a portion of other components may precipitate. However, since the precipitate formation rate may vary slightly depending on the precipitate formation conditions, it is not easy to always stably obtain a raw material powder having the target component composition.

The present inventors had been conducting research for some time in hopes of improving the wet co-precipitation method, and as part of the results, they developed a so-called multi-stage wet precipitation method (Japanese Patent Application Laid-Open Nos. 61-53113 and 61-53114). No. 61-53115
issue). This method is based on the two
This is a method in which precipitation of component A and precipitation of component B are produced stepwise from a mixed solution of soluble compounds containing metal elements (A, B), and with this method, two or more components are highly mutually dispersed. Since a precipitate in a solid state is obtained, agglomeration of particles is unlikely to occur not only during precipitate formation but also during drying and calcining, and an extremely fine, uniform, and easily sinterable powder can be obtained. However, this method is not without its drawbacks; for example, in order to precipitate components that are difficult to precipitate in stages, expensive precipitants such as amines and oxins must be used; The manufacturing cost is higher than that of the usual wet precipitation method in which only the precipitate is used as a precipitant, and it is difficult to say that this method is suitable for practical use.

Recently _, lead perovskite solid solutions have become mainstream as functional ceramics used in piezoelectric materials and _microwave conductors.
A lead perovskite solid solution formed by dissolving O ₃ :Q and R represent various metal elements is attracting attention as a high-performance functional ceramic. When obtaining such a lead perovskite solid solution powder, a powder with excellent uniformity and ease of sintering can be obtained by employing the wet multi-stage precipitation method described in the above-mentioned publication. In particular, ZrO ₂ , which is the raw material powder for PbZrO ₃ , has a very coarse particle size compared to other oxides, and it is virtually impossible to produce high-performance lead perovskite solid solution powder containing PbZrO ₃ by a dry method. However, if a wet multi-stage precipitation method is adopted, it becomes possible to obtain an extremely fine and uniform lead perovskite solid solution powder containing PbZrO ₃ . However, as pointed out earlier, there is an unavoidable disadvantage in terms of cost since an expensive precipitant is required.

[Problems to be Solved by the Invention] The present invention has been made focusing on the above-mentioned circumstances, and its _purpose is to _solve
We would like to provide a method for industrially and inexpensively producing a powder that has excellent uniformity and easy sinterability as a lead perovskite solid solution containing PbTiO ₃ and PbTiO 3 and can provide a sintered body with a high bulk density. That is.
Another object of the present invention is to provide a sintered body using the lead perovskite solid solution powder that has a high bulk density and exhibits excellent performance as a functional ceramic.

[Means for Solving the Problems] The method for producing lead perovskite solid solution powder according to the present invention is based on the general formula Pb(QR)O ₃ (where Q is Mg, Zn, Cr, Mn, Fe, Co,
One or more elements selected from the group consisting of Ni, Cd, In, Sb and rare earth elements, and R
(representing one or more elements selected from the group consisting of Nb, Ta, Te, Sb and W) and PbZrO ₃ and
In producing a solid solution raw material powder containing PbTiO ₃ , a mixed solution of a Pb compound and a Zr compound is mixed with aqueous ammonia to co-precipitate the Pb component and Zr component.
Then, a solution of Ti compound is mixed to precipitate the Ti component, or a solution of Ti compound is mixed with aqueous ammonia.
After the Ti component is precipitated, it is mixed with a mixed solution of the Pb compound and the Zr compound to coprecipitate the Pb component and the Zr component. Whole amount or 2~
The gist is that the compound powder divided into three parts is dispersed at any stage of the precipitation formation process to form a mixed precipitate, and the obtained precipitate is dried and then calcined at 400 to 1300°C. The gist of the structure of the sintered body according to the present invention is that the lead perovskite solid solution powder is further sintered at 900 to 1300°C.

[Function] When a lead perovskite solid solution powder containing lead perovskite represented by the general formula Pb(QR)O ₃ and PbZrO ₃ and PbTiO ₃ is to be produced by a wet method, as well as/
Precipitation of hydroxides, etc. from soluble compounds (or alcohol) can be easily carried out by using inexpensive aqueous ammonia as a precipitant, and the precipitate formation rate reaches almost 100%. On the other hand, Q and R, which are the raw material components of Pb(QR) _O3 ,
soluble compounds (e.g. chlorides, nitrates, etc.)
Not only are they generally more expensive than the corresponding oxides, but also it is difficult to obtain a 100% precipitation rate when aqueous ammonia or the like is used as a precipitation forming agent. Moreover, Q and R oxides, hydroxides, carbonates, oxalates, etc. are extremely fine on the order of submicrons and are relatively inexpensive on the market (water and/or
or compared to alcohol-soluble salts).

Therefore, the present inventors (QR) regarding the O ₂ source,
We thought that it would be more advantageous to use the powder as it is, rather than precipitating it by a wet precipitation method. However, if the powdered (QR)O ₂ source is PbO or
Even if it is mixed and calcined with a raw material powder such as TiO ₂ or ZrO ₂ by a dry method, it is not possible to obtain a raw material powder with excellent uniformity and easy sinterability.

Therefore, raw material components such as PbZrO ₃ and PbTiO ₃ are made into fine powder using a wet precipitation method that allows easy precipitation from relatively inexpensive soluble raw material compounds using an inexpensive precipitant (ammonia, etc.). Moreover, if the insoluble raw material powder serving as the (QR)O ₂ source is allowed to coexist in the precipitation generation system, (QR)
In the dispersion of the O ₂ source, a precipitate of compounds containing Pb, Zr and Ti forms, and Pb(QR)O ₃ , PbZrO ₃ and
We thought that it would be possible to obtain a homogeneous mixed precipitate that would serve as a raw material for PbTiO ₃ , and as a result of further research along this line, we arrived at the present invention.

However, if the insoluble components of Pb, Zr, and Ti are co-precipitated simultaneously from a mixed solution of Pb compound, Zr compound, and Ti compound, a highly uniform precipitate can be obtained, but because the uniformity is too high, On the contrary, particles coagulate with each other during precipitation or during subsequent drying or calcination to produce secondary particles, resulting in coarsening of the particles and no improvement in sinterability.
Moreover, the coprecipitation method cannot be carried out using chlorides, and although it can be carried out using nitrates, it is expensive.

Therefore, in the present invention, at least Zr compound and Ti
A multi-stage precipitation method is used to precipitate the compound.
By suppressing the mutual aggregation of generated particles, the structure is such that a high level of easy sinterability can be ensured at low cost.

That is, in the present invention, a mixed solution of a Pb compound and a Zr compound is mixed with aqueous ammonia to coprecipitate the Pb component and the Zr component,
The suspension is then mixed with a solution of Ti compound.
Either the Ti component is precipitated or a solution of Ti compound is mixed with aqueous ammonia.
After precipitating the Ti component, the suspension is mixed with a mixed solution of a Pb compound and a Zr compound to co-precipitate the Pb component and Zr component. At any stage of the precipitate formation process, the required total amount of the Q and R compound powder or compound powder obtained by dividing it into 2 to 3 parts is added and dispersed at any stage of the precipitate formation process to form a mixed precipitate.

That is, the procedure for producing a mixed precipitate is to suspend the entire required amount of compound powder containing Q or R, then coprecipitate the Pb and Zr components, and then add and disperse the compound powder containing R or Q. A method of precipitating the Ti component after dispersing the compound powder containing Q or R, suspending the required amount of the compound powder containing Q or R, then precipitating the Ti component, further adding and dispersing the compound powder containing R or Q, and then precipitating the Pb and A method of co-precipitating a Zr component, a method of adding and dispersing a compound powder containing Q and R before, during, or after producing a coprecipitation of Pb and Zr components and a precipitation of a Ti component, a method of adding and dispersing a compound powder containing Q and R, A method of adding and dispersing a compound powder containing Q and R before, during or after producing coprecipitation of Pb and Zr components, dividing the compound powder containing Q and R into 2 to 3 parts,
Examples include the method of dividing and adding at arbitrary addition times shown in ~ above. That is, the compound powders Q and R may coexist in a dispersed state in the system at any stage of precipitate formation; for example, they may be suspended in aqueous ammonia as a precipitate forming agent.

The combination of the metal elements Q and R constituting the lead perovskite solid solution defined as Pb(QR)O ₃ in the present invention is the selected element of Q and R specified above, which is electrically +4 valent. Any ^combination is possible as long ^{as it} gives
Ta ⁵⁺ ), (1/2Sb ³⁺ and 1/2Nb ⁵⁺ ), (1/3Mn ²⁺ and 2/3
Examples include groups such as Sb ⁵⁺ ). The reason for specifying the elements Q and R is that the selected elements can exhibit excellent properties as a highly functional ceramic material. In addition, the lead perovskite solid solution in the present invention is a non-stoichiometric lead perovskite in which vacancies are introduced by shifting the molar ratio of Pb to [(Q, R), Zr and Ti] to a value slightly higher or lower than 1.0. include.

In the present invention, specific examples of insoluble compounds used as a (QR)O ₂ source include, but are not limited to, the oxide itself, as well as hydroxides, carbonates, oxalates, etc. that provide oxides upon calcination. Illustrated. Also
The raw material components for PbZrO ₃ and PbTiO ₃ are preferably those that are soluble in water or alcohol (especially water) (including alkoxides), and the most common ones are nitrates and acetates for Pb, and oxynitrates and oxynitrates for Zr. Examples of oxychloride and Ti include chloride, sulfate, and oxynitrate.

The precipitate thus obtained is a fine and homogeneous mixture consisting of hydroxides of Pb, Zr, Ti, etc. and oxides, hydroxides, carbonates, or oxalates of P and Q.
If this is calcined at, for example, 400 to 1300℃, Pb
A uniform, fine, easily sinterable, and inexpensive lead perovskite solid solution powder containing (QR)O ₃ , PbZrO ₃ and PbTiO ₃ is obtained.

At this time, if the calcination temperature is less than 400℃, it is difficult for the intimate mixture to undergo sufficient dehydration or thermal decomposition;
If the temperature exceeds 1300°C, the particles tend to partially aggregate and become coarse, resulting in poor sinterability, so calcination is preferably carried out in the range of 400 to 1300°C.

The powder obtained in this way is Pb(QR)O ₃ ,
It is a fine, uniform, easily sinterable, and inexpensive lead perovskite solid solution powder in which PbZrO ₃ and PbTiO ₃ are mutually dispersed. When sintered, a sintered body having a very high bulk density and exhibiting excellent performance as various functional ceramics as described above can be obtained. The sintering temperature is preferably in the range of 900 to 1300°C. If it is less than 900°C, sintering will be insufficient and the properties required for functional ceramics will not be fully exhibited. On the other hand, if it exceeds 1300°C, the Pb component will be lost during the sintering process. A portion of it undergoes thermal decomposition and Pb is volatilized, making it difficult to obtain the desired composition.

[Examples] Example 1 1.2208 g of fine powder of zinc oxide is dispersed in 200 ml of water, and 800 ml of 4N ammonia water is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 33.121 g in 200 ml of water and 27.485 ml of a zirconium oxynitrate aqueous solution with a concentration of 0.8732 mol/ml was gradually added dropwise to co-precipitate the Pb and Zr components. Add niobium pentoxide fine particle powder to this mixed dispersion liquid.
Add a dispersion of 3.9871g in 100ml of water, and then add a titanium tetrachloride aqueous solution with a concentration of 0.7509mol/while stirring.
A solution of 41.284 ml diluted with water to make 150 ml is gradually added dropwise to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.45Pb
A lead perovskite solid solution powder having a component composition of (Zn _1/3 Nb _2/3 )O ₃ −0.24PbZrO ₃ −0.31PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that it was extremely fine, about 0.2 μm, and had a uniform particle size.

When the powder obtained above was pressure-molded at 1 t/cm ² and sintered at 1200°C for 2 hours in a lead atmosphere, the density
A sintered body of 8.16 was obtained, and it was confirmed that the density reached 99.5% of the theoretical density. The green density during pressure molding was 5.0, which was 61% of the theoretical density.

Comparative Example 1 Commercially available powders of PbO, ZnO, Nb ₂ O ₅ , ZrO ₂ , and TiO ₂ were blended to have the composition of the ternary solid solution of Example 1, and after mixing in a ball mill, the mixture was heated at 800°C for about 2 hours. It was calcined for an hour and ground again in a ball mill. This powder was molded at 1 t/cm ² and heated to 1250°C under a lead atmosphere.
When sintered for a period of time, the density was approximately 6.5, which was only 79.3% of the theoretical density, and considerable compositional variation was observed in some areas.

Example 2 2.6581g of fine powder of niobium pentoxide in 200ml of water
, add 800ml of 4N ammonia water and mix. While stirring this dispersion, a solution of 33.121 g of lead nitrate in 200 ml of water and a concentration of 0.84091 mol/
A mixed solution of 35.676 ml of zirconium oxynitrate aqueous solution was gradually added dropwise to co-precipitate the Pb and Zr components. A dispersion of 0.8027 g of tricobalt tetroxide fine particles in 100 ml of water is added to this mixed dispersion.
While further stirring, 46.407 ml of an aqueous titanium tetrachloride solution with a concentration of 0.86193 mol/diluted with water to make 150 ml was gradually added dropwise to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.3Pb
A lead perovskite solid solution powder having a component composition of (Co _1/3 Nb _2/3 )O ₃ −0.3PbZrO ₃ −0.4PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that it was extremely fine, about 0.2 μm, and had a uniform particle size.

When this powder was pressure molded at 1 t/cm ² , the green density was 5.1, which was 62% of the theoretical density. When this pressure-molded body was sintered at 1200° C. for 2 hours in a lead atmosphere, a sintered body with a density of 8.20 (99.5% of the theoretical density) was obtained.

Comparative Example 2 Commercially available powders of PbO, Co ₃ O ₄ , Nb ₂ O ₅ , ZrO ₂ and TiO ₂ were blended to have the composition of the ternary solid solution of Example 2, and the following was the same as Comparative Example 1. When treated, the density of the obtained sintered body was 7.4 (90% of the theoretical density), and considerable compositional variation was observed in some parts.

Example 3 0.53162g of fine powder of niobium pentoxide in 50ml of water
Add 300ml of 4N ammonia water and mix. While stirring this dispersion, add a solution of 9.936 g of lead nitrate in 50 ml of water and a concentration of 0.84091 mol/
A mixed solution of 13.557 ml of zirconium oxynitrate aqueous solution was gradually added dropwise to co-precipitate the Pb and Zr components. Add a dispersion of 0.08061 g of magnesium oxide fine powder in 50 ml of water to this mixed dispersion. While further stirring, a solution made by adding water to 14.618 ml of an aqueous titanium tetrachloride solution with a concentration of 0.86193 mol/ml to make 50 ml is gradually added dropwise to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.2Pb
A lead perovskite solid solution powder having a component composition of (Mg _1/3 Nb _2/3 )O ₃ −0.38PbZrO ₃ −0.42PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When the powder thus obtained was pressure-molded at 1 t/cm ² , the green density was 4.9, which was 60% of the theoretical density.
When this pressure-molded body was sintered at 1200° C. for 2 hours in a lead atmosphere, a sintered body with a density of 8.09 (99.2% of the theoretical density) was obtained.

Example 4 0.18607g of niobium pentoxide fine powder in 50ml of water
Add 300ml of 4N ammonia water and mix. While stirring this dispersion, add a solution of 9.936 g of lead nitrate in 50 ml of water and a concentration of 0.84091 mol/
A mixed solution of 16.767 ml of zirconium oxynitrate aqueous solution was gradually added dropwise to co-precipitate the Pb and Zr components. A dispersion of 0.06086 g of manganese dioxide fine powder in 50 ml of water is added to this mixed dispersion. While further stirring, 16.011 ml of a titanium tetrachloride aqueous solution with a concentration of 0.86193 mol/diluted with water to make 50 ml was gradually added dropwise to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.07Pb
A lead perovskite solid solution powder having a component composition of (Mn _1/3 Nb _2/3 )O ₃ −0.47PbZrO ₃ −0.46PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When the powder obtained above was pressure molded at 1 t/cm ² , the green density was 4.9, which was 61% of the theoretical density. When this pressure-molded body was sintered at 1200° C. for 2 hours in a lead atmosphere, a sintered body with a density of 8.01 (99.3% of the theoretical density) was obtained.

Example 5 0.14575g of fine particle powder of antimony trioxide was added to water.
Disperse in 50ml, add 300ml of 4N ammonia water and mix. While stirring this dispersion, a titanium tetrachloride aqueous solution with a concentration of 0.86193 mol/
A solution made by adding water to 16.359 ml to make 50 ml is gradually added dropwise to precipitate the Ti component. To this, add a dispersion of 0.04347 g of manganese dioxide fine powder in 50 ml of water, and while stirring, add a solution of 9.936 g of lead nitrate in 50 ml of water and the concentration
A mixed solution with 17.124 ml of a 0.84091 mol/zirconium oxynitrate aqueous solution is gradually added dropwise to co-precipitate the Pb and Zr components.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.05Pb
A lead perovskite solid solution powder having a component composition of (Mn _1/3 Sb _2/3 )O ₃ −0.48PbZrO ₃ −0.47PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was pressure-molded at 1 t/cm ² , the green density was 4.9, which was 60% of the theoretical density. When this pressure-molded body was sintered at 1200° C. for 2 hours in a lead atmosphere, a sintered body with a density of 80.7 (99.2% of the theoretical density) was obtained.

Example 6 0.07974g of niobium pentoxide and yttrium oxide
Mix 0.06774g and disperse in 50ml of water, add 4N
Add 300ml of ammonia water and mix. While stirring this dispersion, add 9.936 g of lead nitrate to 50 g of water.
ml solution and 17.838 ml of a zirconium oxynitrate aqueous solution having a concentration of 0.84091 mol/ml is gradually added dropwise to co-precipitate the Pb component and the Zr component.

Next, while stirring this mixed dispersion, the concentration
Ti
Precipitate the ingredients.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.04Pb
A lead perovskite solid solution powder having a component composition of (Y _1/2 Nb _1/2 )O ₃ −0.50PbZrO ₃ −0.46PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was pressure-molded at 1 t/cm ² , the green density was 4.8, which was 60% of the theoretical density. When this pressure-molded body was sintered at 1250° C. for 2 hours in a lead atmosphere, a sintered body with a density of 8.01 (99.1% of the theoretical density) was obtained.

Example 7 0.15949 g of finely powdered niobium pentoxide and 0.17490 g of antimony trioxide were mixed and dispersed in 50 ml of water.
Add 300ml of 4N ammonia water to this and mix.
While stirring this dispersion, add the concentration
Ti
Precipitate the ingredients. While stirring this mixed dispersion, add a solution of 9.936 g of lead nitrate in 50 ml of water and
A mixed solution with 15.697 ml of a 0.84091 mol/zirconium oxynitrate aqueous solution is gradually added dropwise to co-precipitate the Pb and Zr components.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.08Pb
A lead perovskite solid solution powder having a component composition of (Sb _1/2 Nb _1/2 )O ₃ −0.44PbZrO ₃ −0.48PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When the powder obtained above was press-molded at 1 t/cm ² , the green density was 4.8, which was 59% of the theoretical density, and when this press-molded body was sintered at 1250°C for 2 hours in a lead atmosphere, A sintered body with a density of 8.10 (99.0% of the theoretical density) was obtained.

Example 8 0.23923 g of fine powder of niobium pentoxide is dispersed in 50 ml of water, and 300 ml of 4N ammonia water is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 9.936 g in 50 ml of water and 16.767 ml of a zirconium oxynitrate aqueous solution with a concentration of 0.84091 mol/ml was gradually added dropwise to co-precipitate the Pb and Zr components. Furthermore, a solution made by adding water to 16.707 ml of an aqueous titanium tetrachloride solution with a concentration of 0.86193 mol/ml to make 50 ml was gradually added dropwise to precipitate the Ti component. To this, add 0.14372 g of fine powder of iron oxide (2018) dispersed in 50 ml of water.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.12Pb
A lead perovskite solid solution powder having a component composition of (Fe _1/2 Nb _1/2 )O ₃ −0.47PbZrO ₃ −0.41PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was pressure-molded at 1 t/cm ² , the green density was 4.8, which was 60% of the theoretical density. When this pressure-molded body was sintered at 1250° C. for 2 hours in a lead atmosphere, a sintered body with a density of 8.02 (99.3% of the theoretical density) was obtained.

Example 9 0.33140 g of tantalum pentoxide fine powder is dispersed in 50 ml of water, and 300 ml of 4N ammonia water is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 50 ml of water containing 9.936 g and 14.270 ml of zirconium oxynitrate aqueous solution having a concentration of 0.84091 mol/ml was gradually added dropwise to co-precipitate the Pb and Zr components. Fine powder of iron oxide () is added to this mixed dispersion.
Add a dispersion of 0.11977g in 50ml of water, and while stirring,
Titanium tetrachloride aqueous solution 17.403 with a concentration of 0.86193 mol/
Gradually drop a solution of 50ml by adding water to
Precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.1Pb
A lead perovskite solid solution powder having a component composition of (Fe _1/2 Ta _1/2 )O ₃ −0.4PbZrO ₃ −0.5PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there was almost no local variation in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was pressure-molded at 1 t/cm ² , the green density was 5.0, which was 61% of the theoretical density. When this pressure-molded body was sintered at 1250° C. for 2 hours in a lead atmosphere, a sintered body with a density of 8.13 (99.4% of the theoretical density) was obtained.

Example 10 0.18607 g of fine powder of niobium pentoxide is dispersed in 50 ml of water, and 300 ml of 4N aqueous ammonia is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 9.936 g in 50 ml of water and 17.838 ml of a zirconium oxynitrate aqueous solution with a concentration of 0.84091 mol/ml was gradually dropped to co-precipitate the Pb component and Zr component. Fine powder of cadmium oxide is added to this mixed dispersion.
Add 0.08989 g dispersed in 50 ml of water, and while stirring, add water to 14.966 ml of an aqueous titanium tetrachloride solution with a concentration of 0.86193 mol/ml to make 50 ml and gradually drop the solution to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.07Pb
A lead perovskite solid solution powder having a component composition of (Cd _1/3 Nb _2/3 )O ₃ −0.5PbZrO ₃ −0.43PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there were almost no local variations in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was press-molded at 1 t/cm ² , the green density was 4.8, which was 60% of the theoretical density, and when this press-molded body was sintered at 1200°C for 2 hours in a lead atmosphere, the density was 7.99 ( A sintered body with a density of 99.3% of the theoretical density was obtained.

Example 11 0.26581 g of fine powder of niobium pentoxide is dispersed in 50 ml of water, and 300 ml of 4N aqueous ammonia is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 9.936 g in 50 ml of water and 16.054 ml of a zirconium oxynitrate aqueous solution with a concentration of 0.84091 mol/ml was gradually added dropwise to co-precipitate the Pb and Zr components. To this mixed dispersion, add 0.08269 g of fine powder of nickel oxide () dispersed in 50 ml of water, and while stirring, add water to 15.663 ml of titanium tetrachloride aqueous solution with a concentration of 0.86193 mol/ to make a solution of 50 ml. Gradually drop it to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.1Pb
A lead perovskite solid solution powder having a component composition of (Ni _1/3 Nb _2/3 )O ₃ −0.45PbZrO ₃ −0.45PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there were almost no local variations in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was press-molded at 1 t/cm ² , the green density was 4.9, which was 61% of the theoretical density, and when this press-molded body was sintered at 1200°C for 2 hours in a lead atmosphere, the density was 8.02 ( A sintered body with a density of 99.4% of the theoretical density was obtained.

Example 12 0.52166 g of fine tungsten trioxide powder was added to 50 g of water.
ml, add 300ml of 4N ammonia water and mix. While stirring this dispersion, add a solution of 9.936 g of lead nitrate in 50 ml of water at a concentration of 0.84091 mol/
A mixed solution of 12.486 ml of zirconium oxynitrate aqueous solution was gradually added dropwise to co-precipitate the Pb and Zr components. To this mixed dispersion, add 0.09068g of fine powder of magnesium oxide dispersed in 50ml of water, and while stirring, gradually add water to 17.403ml of titanium tetrachloride aqueous solution with a concentration of 0.86193mol/ to make 50ml. dropwise to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.15Pb
A lead perovskite solid solution powder having a component composition of (Mg _1/2 W _1/2 )O ₃ −0.35PbZrO ₃ −0.5PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there were almost no local variations in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was pressure-molded at 1 t/cm ² , the green density was 5.2, which is 60% of the theoretical density, and when this press-molded body was sintered at 1200°C for 2 hours in a lead atmosphere, the density was 8.55 ( A sintered body with a density of 99.2% of the theoretical density was obtained.

Example 13 0.19936 g of fine powder of niobium pentoxide is dispersed in 50 ml of water, and 300 ml of 4N aqueous ammonia is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 9.936 g in 50 ml of water and 16.054 ml of a zirconium oxynitrate aqueous solution with a concentration of 0.84091 mol/ml was gradually added dropwise to co-precipitate the Pb and Zr components. Fine powder of indium oxide is added to this mixed dispersion.
Add 0.20823 g dispersed in 50 ml of water, and while stirring, add water to 16.054 ml of an aqueous titanium tetrachloride solution with a concentration of 0.86193 mol/ml to make 50 ml and gradually drop the solution to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.1Pb
A lead perovskite solid solution powder having a component composition of (In _1/2 Nb _1/2 )O ₃ −0.45PbZrO ₃ −0.45PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there were almost no local variations in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was press-molded at 1 t/cm ² , the green density was 4.9, which was 61% of the theoretical density, and when this press-molded body was sintered at 1200°C for 2 hours in a lead atmosphere, the density was 8.02 ( A sintered body with a density of 99.3% of the theoretical density was obtained.

Example 14 0.13955 g of fine powder of niobium pentoxide is dispersed in 50 ml of water, and 300 ml of 4N ammonia water is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 9.936 g in 50 ml of water and 17.838 ml of a zirconium oxynitrate aqueous solution with a concentration of 0.84091 mol/ml was gradually added dropwise to co-precipitate the Pb and Zr components. To this mixed dispersion, add 0.07980 g of fine powder of chromium oxide () dispersed in 50 ml of water, and while stirring, add water to 14.966 ml of titanium tetrachloride aqueous solution with a concentration of 0.86193 mol/ to make a solution of 50 ml. Gradually drop it to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.07Pb
A lead perovskite solid solution powder having a component composition of (Cr _1/2 Nb _1/2 )O ₃ −0.5PbZrO ₃ −0.43PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there were almost no local variations in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was press-molded at 1 t/cm ² , the green density was 4.9, which was 61% of the theoretical density, and when this press-molded body was sintered at 1150°C for 2 hours in a lead atmosphere, the density was 8.02 ( A sintered body with a density of 99.4% of the theoretical density was obtained.

Example 15 0.23940 g of fine powder of tellurium dioxide is dispersed in 50 ml of water, and 300 ml of 4N ammonia water is added and mixed. While stirring this dispersion, add lead nitrate to it.
A mixed solution of 9.936 g in 50 ml of water and 17.124 ml of a zirconium oxynitrate aqueous solution with a concentration of 0.84091 mol/ml was gradually dropped to co-precipitate the Pb and Zr components. Fine powder of zinc oxide is added to this mixed dispersion.
Add 0.12208 g dispersed in 50 ml of water, and while stirring, add water to 14.618 ml of an aqueous titanium tetrachloride solution with a concentration of 0.86193 mol/ml to make 50 ml and gradually drop the solution to precipitate the Ti component.

After filtering and drying the homogeneous mixture of all the components obtained in this way, when calcined at 700℃ for 2 hours, 0.1Pb
A lead perovskite solid solution powder having a component composition of (Zn _1/2 Te _1/2 )O ₃ −0.48PbZrO ₃ −0.42PbTiO ₃ was obtained. When this powder was examined by X-ray diffraction, it was confirmed that there were almost no local variations in composition and that it was extremely uniform.

Further, when the particle size of the powder was examined using a scanning electron microscope, it was confirmed that the powder was very fine, about 0.3 μm, and had a uniform particle size.

When this powder was press-molded at 1 t/cm ² , the green density was 4.9, which was 60% of the theoretical density, and when this press-molded body was sintered at 1150°C for 2 hours in a lead atmosphere, the density was 8.07 ( A sintered body with a density of 99.3% of the theoretical density was obtained.

[Effects of the Invention] The present invention is configured as described above, and its effects are summarized as follows.

(1) Unlike the conventional coprecipitation method, this is a method in which the Q and R components are made into powder dispersions, and the coprecipitation of Pb and Zr components and the precipitation of the Ti component are sequentially produced in multiple stages. Since the multiphase components coexist in a mutually dispersed state, particle agglomeration is difficult to occur during drying or calcination, and the lead perovskite has a fine and uniform particle size structure and is easy to sinter. Raw material powder is obtained.

(2) If fine particles are selected as raw materials for the Q and R components, submicron-order lead perovskite fine particles can be easily obtained, and a sintered molded body with a high bulk density can be obtained.

(3) Since the components Q and R, which are difficult to form precipitates, are dispersed as insoluble powders, a lead perovskite solid solution powder having a desired composition can be obtained.

(4) Since the resulting mixed precipitate is a highly interdispersed homogeneous body, the calcined product is extremely uniform, and the sintered body obtained by sintering this is also extremely uniform. Coupled with the characteristics that it is possible to obtain a product with a high degree of strength and a high bulk density, it exhibits outstanding performance as a functional ceramic.

(5) Easy-to-handle and inexpensive raw materials and precipitants can be used, and the manufacturing process is simple, so lead perovskite solid solution powders and sintered bodies can be obtained at extremely low prices.

(6) The lead perovskite solid solution powder obtained in this way can not only be used as it is as a catalyst, etc., but when sintered, a high bulk density sintered body with a density extremely close to the theoretical value can be obtained, and it has improved functionality. The performance of the ceramics can be significantly improved compared to conventional ceramics.

Claims (1)

[Claims] 1 General formula Pb(QR)O ₃ (where Q is Mg, Zn, Cr, Mn, Fe, Co,
One or more elements selected from the group consisting of Ni, Cd, In, Sb and rare earth elements, and R
(representing one or more elements selected from the group consisting of Nb, Ta, Te, Sb and W) and PbZrO ₃ and
In producing a solid solution powder containing _PbTiO3 , a mixed solution of a Pb compound and a Zr compound is mixed with aqueous ammonia to co-precipitate the Pb component and Zr component.
Then, a solution of Ti compound is mixed to precipitate the Ti component, or a solution of Ti compound is mixed with aqueous ammonia.
After the Ti component is precipitated, it is mixed with a mixed solution of the Pb compound and the Zr compound to coprecipitate the Pb component and the Zr component. Whole amount or 2~
A lead perovskite solid solution powder characterized in that the compound powder divided into three parts is dispersed at any stage of the precipitation formation process to form a mixed precipitate, and the resulting precipitate is dried and then calcined at 400 to 1300°C. Production method. 2 General formula Pb(QR)O ₃ (where Q is Mg, Zn, Cr, Mn, Fe, Co,
One or more elements selected from the group consisting of Ni, Cd, In, Sb and rare earth elements, and R
(representing one or more elements selected from the group consisting of Nb, Ta, Te, Sb and W) and PbZrO ₃ and
In producing a solid solution powder containing _PbTiO3 , a mixed solution of a Pb compound and a Zr compound is mixed with aqueous ammonia to co-precipitate the Pb component and Zr component.
Then, a solution of Ti compound is mixed to precipitate the Ti component, or a solution of Ti compound is mixed with aqueous ammonia.
After the Ti component is precipitated, it is mixed with a mixed solution of the Pb compound and the Zr compound to coprecipitate the Pb component and the Zr component. Whole amount or 2~
The compound powder divided into three parts is dispersed at any stage of the precipitation formation process to form a mixed precipitate, and the resulting precipitate is dried and then calcined at 400 to 1300°C to obtain a lead perovskite solid solution powder. A lead perovskite solid solution sintered body characterized by being sintered at 1300℃.