JP3154513B2 - Spherical barium titanate-based semiconductor ceramic material powder and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spherical barium titanate-based semiconductor porcelain material powder used for semiconductor porcelain such as PTC thermistors and semiconductor capacitors, and a method for producing the same.

[0002]

2. Description of the Related Art In a PTC thermistor, the grain size is made uniform and the thickness of the grain boundary (grain boundary phase) is made constant in order to make the room temperature specific resistance low, the resistance change rate large, and the mechanical strength large. It is requested to do.

Further, in order to obtain a semiconductor capacitor having a large dielectric constant, a small dielectric loss, a good withstand voltage characteristic and a high mechanical strength, the grain size is made uniform and the thickness of the grain boundary is kept constant. It is requested that

Normally, the grain size of semiconductor porcelain such as PTC thermistors and semiconductor capacitors is controlled from submicron to 50 μm. Therefore, it is required that the material powder used has a particle size of 0.3 to 50 μm or less, preferably 0.5 to 50 μm, a narrow particle size distribution and good dispersibility.

However, the barium titanate-based semiconductor porcelain powder produced by the conventional method cannot sufficiently meet the above-mentioned demands.

That is, the conventional barium titanate-based semiconductor ceramic material powder has been produced by a method in which titanium oxide, barium carbonate, a semiconducting element, and the like are mixed to cause a solid-phase reaction.

However, in the case of the solid-phase reaction, the barium titanate-based semiconductor porcelain material powder obtained has a large particle diameter due to the reaction at a high temperature, and is therefore mechanically pulverized to obtain a desired particle diameter. However, the dispersion of the particle size is large and the shape is not uniform, so the dispersibility is poor. Even when PTC thermistors and semiconductor capacitors are manufactured using this, the grain size varies and the electrical characteristics are excellent. Was not obtained.

In order to solve these problems, attempts have been made to produce a barium titanate-based semiconductor porcelain material powder by a wet coprecipitation method using oxalate (for example, 90 [8] ], 1982).

However, the method described above has a drawback that only fine particles of the semiconductor ceramic material powder can be obtained, and that the particles have irregular shapes or particles are associated with each other. A barium titanate-based semiconductor ceramic material powder having a diameter of 0.3 μm or more, a narrow particle size distribution, and good dispersibility was not obtained.

In Japanese Patent Application Laid-Open No. 2-289426, a barium titanate-based semiconductor porcelain material powder having a high cohesiveness of 150 μm or more is produced, and is used after being crushed by a ball mill or the like before ceramicization. However, since the degree of crushing was difficult to control and the shape was not constant, the dispersibility was poor and it could not be said that it was sufficiently satisfactory.

[0011]

As described above, the conventional barium titanate-based semiconductor porcelain material powder cannot sufficiently control the particle diameter, has poor dispersibility, and has excellent electrical characteristics. Semiconductor ceramics such as a PTC thermistor and a semiconductor capacitor could not be obtained.

Accordingly, an object of the present invention is to provide a barium titanate-based semiconductor porcelain material powder capable of sufficiently controlling the particle diameter and having high dispersibility.

[0013]

Means for Solving the Problems The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, have found that hydrogen peroxide coexists during a wet reaction in producing barium titanate-based semiconductor ceramic material powder. Depending on the particle size, 0.3 to 5
A spherical barium titanate-based semiconductor porcelain material powder having a narrow particle size distribution of μm can be obtained, and a spherical barium titanate-based semiconductor porcelain material powder having a particle diameter of 5 to 50 μm can be obtained by flash drying after a wet reaction. This led to the completion of the present invention.

That is, the spherical barium titanate-based semiconductor porcelain material powder of the present invention contains a trivalent or pentavalent semiconducting element in an amount of 0.05 to 2 atomic% with respect to titanium, and its base material is made of ATiO. ₃ (A is Ba ≧ 50 atomic%, 0 atomic%
≦ Sr, Ca, Pb ≦ 50 atomic%) is a spherical barium titanate-based semiconductor ceramic material powder having a particle diameter of 0.3 to 50 μm.

When A in the above formula is represented by a sentence, A is Ba
Or, it is composed of Ba and at least one selected from the group consisting of Sr, Ca and Pb, wherein Ba is 50 to 100.
In atomic%, Sr, Ca and Pb are 0 to 50 atomic%. Ba is barium, Sr is strontium, Ca is calcium, and Pb is lead.

Here, the base material portion represented by ATiO ₃ of the spherical barium titanate-based semiconductor ceramic material powder of the present invention is specifically expressed by a name.
Barium strontium titanate, barium strontium calcium titanate, barium strontium lead titanate, barium strontium calcium lead titanate, barium calcium titanate, barium lead titanate, barium calcium lead titanate.

A barium compound and a strontium compound produce a perovskite compound by a wet reaction with a titanium compound, whereas a calcium compound and a lead compound are difficult to produce a perovskite compound by a wet reaction with a titanium compound.

Therefore, among those represented by ATiO ₃ , barium titanate is obtained by a wet reaction between a titanium compound and a barium compound, and barium strontium titanate is usually obtained by reacting a titanium compound with a barium compound and a strontium compound. Obtained by a wet reaction.

However, those containing calcium and lead cannot be obtained by a wet reaction between a calcium compound or a lead compound and a titanium compound, and therefore, cannot be obtained during a wet reaction between a titanium compound and a barium compound, or between a titanium compound and a barium compound and strontium. During wet reaction with the compound, calcium titanate having a particle diameter of 0.2 μm or less or a particle diameter of 0.2 μm
m or less by adding lead titanate.

Further, after a wet reaction between a titanium compound physically mixed with calcium titanate or lead titanate and a barium compound, or between a titanium compound physically mixed with calcium titanate or lead titanate and a barium compound After the wet reaction with the strontium compound and drying and calcining, a compound having a uniform composition can be obtained.

A particle diameter of 0.3 to 3 containing a trivalent or pentavalent semiconducting element in an amount of 0.05 to 2 atomic% with respect to titanium.
Of the spherical barium titanate-based semiconductor porcelain material powder having a particle size of 0.3 to 5 μm, a powder having a small particle diameter of 0.3 to 5 μm is used during a wet reaction between a titanium compound and a barium compound in a system in which a semiconducting element is present, or At the time of a wet reaction between a titanium compound and a barium compound or a strontium compound (when a compound containing calcium or lead is required, calcium titanate having a particle size of 0.2 μm or less or a particle size of 0.2
μm lead titanate is added, and when strontium is introduced by adding strontium titanate, strontium titanate having a particle diameter of 0.2 μm or less produced by a wet reaction is separately added to the above reaction system. ) In the presence of hydrogen peroxide.

This is because the coexisting hydrogen peroxide causes the production reaction of the barium titanate-based semiconductor ceramic material powder to proceed more slowly than in the case where hydrogen peroxide does not coexist.
It is considered that it suppresses the generation of fine barium titanate-based semiconductor porcelain material powder and generates spherical barium titanate-based semiconductor porcelain material powder having a particle diameter of 0.3 to 5 μm and a narrow particle size distribution. .

Based on the fact that the production reaction of the barium titanate-based semiconductor porcelain material began to progress slowly by using hydrogen peroxide as described above,
The particle size of the obtained barium titanate-based semiconductor ceramic material powder can be arbitrarily controlled by changing the reaction conditions of the wet reaction.

Among the barium titanate-based semiconductor ceramic material powders having a particle diameter of 0.3 to 50 μm of the present invention, those having a large particle diameter of 5 to 50 μm can be obtained by flash drying after the wet reaction.

The trivalent or pentavalent semiconducting element of the present invention is contained in an amount of 0.05 to 2 atomic% based on titanium, and the base material has a particle diameter of 0.3 to 50 μm represented by ATiO ₃ . Spherical barium titanate-based semiconductor porcelain material powder is literally spherical in shape, narrow in particle size distribution, excellent in dispersibility, and its particle size can be arbitrarily controlled. It is possible to obtain a semiconductor ceramic such as a PTC thermistor and a semiconductor capacitor having a small grain size and a small variation in the grain size, and excellent in electrical characteristics and mechanical characteristics.

When the above-mentioned spherical barium titanate-based semiconductor porcelain material powder is calcined, the crystal form changes from pseudo cubic to cubic or tetragonal, the crystallinity improves, and the grain size and grain boundary increase. A more preferable semiconductor ceramic material powder that can be easily controlled can be obtained.

The cubic or tetragonal barium titanate-based semiconductor porcelain material powder obtained by the calcination is literally a spherical barium titanate-based semiconductor porcelain material powder before calcination, and the contact between the particles is Since the amount is small, sintering due to calcination is small, the particle diameter of the spherical barium titanate-based semiconductor ceramic material powder before calcination is almost maintained, the particle size distribution is narrow, and the dispersibility is excellent.

Also, by selecting the calcination temperature,
A spherical barium titanate-based semiconductor porcelain material powder that has been semiconductive in a powder state can also be used.

Further, by increasing the calcination temperature,
A higher density single crystal having a rectangular parallelepiped shape can be obtained.

Next, the significance of each component of the spherical barium titanate-based semiconductor ceramic material powder of the present invention will be described.

In the present invention, the trivalent or pentavalent semiconducting element may be any element which exhibits semiconductivity by substituting Ba or Ti in the perovskite structure of barium titanate. Alternatively, as the pentavalent semiconducting element, for example, Nb, Sb, Ta, Bi, B and Y, L
At least one selected from the group consisting of rare earth elements such as a, Ce, Pr, and Nd is used.

These trivalent or pentavalent semiconducting elements are:
0.1% of titanium in the finally formed ATiO ₃ .
It is used so as to be 0.5 to 2 atomic%. In other words, if the trivalent or pentavalent semiconducting element is less than the above range, sufficient semiconductivity will not be exhibited, and if the trivalent or pentavalent semiconducting element exceeds the above range, valence compensation will not be performed. Wake up
No longer exhibits semiconductivity.

In the spherical barium titanate semiconductor ceramic material powder of the present invention, the base material excluding the semiconducting element is made of ATiO _3.
In this ATiO ₃ , A is represented by Ba ≧
50 atomic%, 0 atomic% ≦ Sr, Ca, Pb ≦ 50 atomic%
It is.

This is because when Ba is less than 50 atomic%, spherical particles cannot be obtained by the wet reaction. Sr, Ca, Pb, and the like are added for the purpose of changing the temperature at which resistance changes when a PTC thermistor is used, and controlling the sintering temperature and dielectric characteristics of a semiconductor capacitor.

Next, the reaction material will be described. As described above, barium compounds and strontium compounds generate perovskite-type compounds by a wet reaction with titanium compounds, but calcium compounds and lead compounds generate perovskite-type compounds by a wet reaction with titanium compounds. When a barium compound or a strontium compound and a titanium compound are subjected to a wet reaction, a perovskite compound is not formed even if a calcium compound or a lead compound is added.

Therefore, when calcium or lead is to be included in the spherical barium titanate-based semiconductor porcelain material powder, calcium titanate or lead titanate produced by a solid-phase reaction is pulverized, if necessary, to obtain particles. When the barium compound or the strontium compound and the titanium compound are added during the wet reaction of the barium compound or the strontium compound with the titanium compound, the barium titanate particles or the barium strontium titanate particles are formed, and when the spherical aggregate is formed, A method is employed in which calcium oxide and lead titanate are uniformly dispersed in their spherical aggregates.

Further, by adding strontium titanate having a particle diameter of 0.2 μm or less during the wet reaction between the barium compound and the titanium compound, strontium can be included in the spherical barium titanate-based semiconductor ceramic material powder. is there.

As described above, a semiconducting element can be contained in advance in calcium titanate, lead titanate, strontium titanate or the like added to the reaction system.

In the present invention, the particle diameter of the added calcium titanate, lead titanate, strontium titanate or the like is set to 0.2 μm or less because the particle diameter is 0.2 μm.
When larger particles are used, the dispersion of the additive particles in the aggregate of barium titanate particles or barium strontium titanate particles becomes non-uniform, hardly becoming spherical particles, and the additive during calcination or ceramicization. This is because the diffusion of the particles becomes insufficient, and a uniform composition cannot be obtained.

In the present invention, the titanium compound includes
As long as it reacts with a barium compound to produce perovskite-type barium titanate, it can be used without any particular limitation, but it partially or completely dissolves in an aqueous solution of hydrogen peroxide. Those which are preferable are those which do not contain as much as possible a component which deteriorates the characteristics by being mixed into the produced barium titanate.

From such a viewpoint, examples of preferred titanium compounds include, for example, inorganic titanium compounds such as titanium oxide and titanium hydroxide, and organic titanium compounds such as titanium oxalate and titanium alkoxide.

Usually, the above-mentioned titanium hydroxide is obtained by hydrolysis of an aqueous solution of a titanium alkoxide or a titanium salt, and the titanium oxide is obtained by wet heating of titanium hydroxide or thermal hydrolysis of a titanium salt.

As a method for adding a semiconducting element, a semiconducting agent (a compound of a semiconducting element which generates a semiconducting element by hydrolysis or the like) in a titanium solution before hydrolysis is used. It is preferable to add a predetermined amount and dissolve it. That is, the semiconducting agent is added to the titanium solution, and the semiconducting agent is hydrolyzed simultaneously with the hydrolysis of the titanium solution (that is, the hydrolysis of the semiconducting element and the hydrolysis of titanium occur simultaneously). (precipitation at the same pH), the titanium oxide containing the semiconducting element and the titanium oxide containing the semiconducting element, the semiconducting element is uniform in the finally formed barium titanate semiconductor ceramic material powder. Will be distributed.

As the barium compound, any compound can be used without particular limitation as long as it reacts with the above-mentioned titanium compound to form perovskite-type barium titanate. Is done.

It is preferable that the barium titanate contains as little as possible a component which deteriorates its properties by being mixed with barium titanate. From such a viewpoint, preferable barium compounds include, for example, barium hydroxide and barium oxide. And alkoxides of barium.

The strontium compound is the same as the barium compound, and any strontium compound that can react with the titanium compound to form perovskite-type strontium titanate can be used without any particular limitation. Strontium compounds are used. Preferred strontium compounds include, for example, strontium hydroxide, strontium oxide, and strontium alkoxide.

As the hydrogen peroxide, various types can be used without any particular limitation. However, usually, 30% (% by weight, the same applies hereinafter) of a commercially available hydrogen peroxide is used because of easy availability and handling. Hydrogen water, 35% aqueous hydrogen peroxide, 50% aqueous hydrogen peroxide, 60% aqueous hydrogen peroxide and the like are used.

Next, the reaction method will be described. When a strontium compound is used, it may be handled almost in the same manner as a barium compound. Therefore, the description is omitted particularly when the strontium compound is not specific to the strontium compound. In the description, it is assumed that the semiconducting element is contained in the titanium compound in advance. However, in practice, the semiconducting element is not limited to only that case,
It may be added during the wet reaction of the titanium compound and the barium compound, or may be added to the barium compound.

These titanium compounds, barium compounds,
There is no particular limitation on the reaction order of hydrogen peroxide, but it is preferable to mix and react the titanium compound and hydrogen peroxide before adding the barium compound, except when reacting at a dilute concentration. That is, unless hydrogen peroxide is added to a system in which a barium compound is present, except when the reaction is performed at a dilute concentration, sparingly soluble barium peroxide (BaO ₂ ) is generated and precipitates, and the reaction does not take part in the reaction. It is.

The amount of hydrogen peroxide to be used is from 0.1 to 0.1 as a molar ratio of hydrogen peroxide to a titanium compound (converted to titanium oxide), that is, H ₂ O ₂ / TiO ₂ (molar ratio).
10 is preferred.

When hydrogen peroxide is reacted with a titanium compound which is not liable to produce peroxide, the amount of peroxide produced is reduced. Therefore, if the amount of peroxide produced is to be increased, excessive use of hydrogen peroxide is required. There is a need to. Therefore, the amount of hydrogen peroxide may be excessive with respect to the titanium compound,
Nevertheless, if the molar ratio with respect to the titanium compound is more than 10, no further increase in the effect is observed, and the compound is only decomposed during the reaction with the titanium compound, which is uneconomical. On the other hand, if the amount of hydrogen peroxide is less than 0.1 in terms of the molar ratio with respect to the titanium compound, the effect of adding hydrogen peroxide cannot be sufficiently obtained.

When a titanium compound and hydrogen peroxide are mixed, they react to form a peroxide of titanium, which usually produces a yellow sol-like solution.

The temperature at the time of mixing the hydrogen peroxide may be room temperature, but in order to facilitate the formation of titanium peroxide and to remove residual hydrogen peroxide in as short a time as possible, 40 to 1 is preferred.
It is preferred to heat to 00C, especially 70 to 100C.

The concentration of the titanium compound in terms of titanium oxide is 0.01 to 2.0 with the barium compound added.
5 mol / l, particularly preferably 0.06-1 mol / l. If the above concentration exceeds 2.5 mol / l, it becomes highly viscous and difficult to stir, and the barium titanate-based semiconductor ceramic material powder obtained by reacting with the barium compound has a non-uniform particle diameter. become. The above concentration is 0.01
When it is lower than mol / l, the reaction rate is significantly reduced.

The titanium peroxide solution thus obtained has an atomic ratio of barium to titanium, that is, Ba / Ti (atomic ratio) of 0.8 to 10, preferably 1 to 10.
A barium compound is added, uniformly mixed, and reacted so as to become ~ 3.

At this time, the titanium compound reacts with the barium compound to produce a pseudo-cubic perovskite-type barium titanate-based semiconductor ceramic material powder.
In order to obtain a spherical barium titanate-based semiconductor porcelain material powder of m, titanium and barium titanate are used so that the reaction for producing the barium titanate-based semiconductor porcelain material powder is not completed within one hour, preferably within four hours. It is preferable to set the atomic ratio, the concentration of the barium compound, the reaction temperature and the like.

In order to make the obtained spherical barium titanate-based semiconductor ceramic material powder uniform in particle size and narrow in particle size distribution, the mixing of the titanium compound and the barium compound is performed at a temperature lower than the temperature at which the reaction starts. Is preferred.

Further, the temperature at which the reaction between the titanium compound and the barium compound is completed in 4 hours, and 50 ° C.
0.1C below the temperature, desirably between the temperature at which the reaction is completed in 4 hours and 40C below that temperature.
It is preferable to carry out the aging reaction for at least one hour, preferably at least one hour. After the aging reaction, the reaction is preferably completed at a temperature not lower than the temperature at which the reaction is completed in 4 hours. The completion of the above-mentioned reaction refers to a state in which the integrated intensity of the barium titanate-based semiconductor ceramic material powder by X-ray diffraction does not substantially change even if the reaction is further continued.

Usually, the aging reaction is carried out at 40 to 100 ° C., preferably 60 to 100 ° C. This aging reaction is performed under normal pressure or reduced pressure. For example, when this aging reaction is performed in a pressurized state using a closed container, the obtained barium titanate-based semiconductor porcelain material powder tends to become fine particles of 0.1 μm or less, and even if it becomes 0.3 μm or more, it becomes spherical Particles, and the particle size distribution becomes wide, and a spherical barium titanate-based semiconductor ceramic material powder of 0.3 to 5 μm as in the present invention cannot be obtained. This tendency is particularly remarkable when a pressure reaction is performed at 100 ° C. or higher.

During the reaction, it is preferable to flow nitrogen into the reaction system so that the barium compound does not react with components such as carbon gas in the air.

The factors affecting the particle size of the resulting barium titanate-based semiconductor ceramic material powder during the above reaction are as follows.

As the concentration of the solution, particularly the barium ion concentration, increases, the particle size tends to decrease.

As for Ba / Ti (atomic ratio), as the ratio increases, the barium ion concentration increases, so that the particle diameter of the barium titanate-based semiconductor ceramic material powder tends to decrease.

The reaction temperature between the titanium compound and hydrogen peroxide is such that the higher the temperature, the smaller the particle size of the barium titanate-based semiconductor porcelain material powder, and the lower the temperature, the smaller the particle size of the barium titanate-based semiconductor porcelain material powder. The diameter increases.

As for the aging reaction temperature, the particle size becomes larger as the aging reaction is carried out for a longer time near the temperature at which the titanium compound reacts with the barium compound to produce barium titanate. In addition, the particle size decreases as the aging reaction temperature increases.

In the case of producing a spherical barium titanate-based semiconductor ceramic material powder containing strontium, the total barium and strontium ratio of barium to titanium alone is set to be at least 50 atomic% while maintaining the barium ratio at 50 atomic% or more. Can be considered in the same manner as the atomic ratio of barium to titanium when used.

In the case of producing the spherical barium titanate-based semiconductor ceramic material powder containing strontium, the strontium compound reacts more easily than the barium compound. Sr of barium-based semiconductor ceramic material powder
It is necessary to keep the ratio smaller than the / Ba atomic ratio.

Further, calcium (Ca) and lead (Pb)
The production of a spherical barium titanate-based semiconductor porcelain material powder containing calcium, calcium titanate (CaTiO ₃ ) or lead titanate (PbTiO ₃ ) having a particle size of 0.2 μm or less is carried out during a wet reaction between a titanium compound and a barium compound. Alternatively, it is added in advance during the wet reaction of the titanium compound with the barium compound and the strontium compound.

The fine particles of lead titanate are described, for example, in JP-A-3-8.
It can be produced by the method described in Japanese Patent No. 0117, and calcium titanate can be produced by the same method.

Further, spherical strontium titanate (SrTiO ₃ ) having a particle diameter of 0.2 μm or less is added during a wet reaction between a titanium compound and a barium compound to produce a spherical barium titanate semiconductor ceramic material powder containing strontium. It is also possible.

In producing a spherical barium titanate-based semiconductor porcelain material powder containing calcium or lead, or a spherical barium titanate-based semiconductor porcelain material powder containing strontium using fine particles, titanate to be added is used. The particle diameters of calcium, lead titanate, strontium titanate and the like are specified to be 0.2 μm or less, as described above, when their particle diameters are larger than 0.2 μm, the composition becomes unsatisfactory when calcined. It is difficult to obtain a uniform spherical barium titanate-based semiconductor ceramic material powder.

The thus obtained particle size of 0.3 to 5
μm spherical barium titanate-based semiconductor porcelain powder
Since the coagulation is firm, the coagulation state is not broken even if ordinary operations such as washing with water, filtration, drying and calcination are performed.

Final A / Ti (atomic ratio) after wet reaction
Can be adjusted to the target A / Ti (atomic ratio) by washing with water or adjusting the pH with an acid such as acetic acid as needed.

Usually, it is preferable to adjust the A / Ti (atomic ratio) of the spherical barium titanate-based semiconductor ceramic material powder to be between 0.98 and 1.02. When A / Ti (atomic ratio) is smaller than 0.98, the ceramic obtained by molding and sintering the barium titanate-based semiconductor porcelain material does not exhibit semiconductivity, and the A / Ti (atomic ratio) ratio)
Is larger than 1.02, the barium titanate-based semiconductor porcelain material powder is molded,
In ceramics obtained by sintering to ceramics, excess barium is present in large amounts at the grain boundaries, and the resistivity-temperature characteristics (P
(TC characteristic). A / Ti
When the (atomic ratio) is increased to 1.05 or more, the ceramic obtained by molding and sintering the barium titanate-based semiconductor ceramic material powder does not exhibit semiconductivity.

In order to obtain a spherical barium titanate-based semiconductor ceramic material powder having a particle diameter of 5 to 50 μm, in the above-mentioned wet reaction, the reaction is carried out without adding hydrogen peroxide (hydrogen peroxide may be added). After preparing primary particles having a particle size of 0.2 μm or less and having no aggregation, washing and filtering are performed, and A / Ti (atomic ratio) is adjusted to an arbitrary value of 0.98 to 1.02. The slurry is re-slurried and flash dried.

As a flash drying method, for example, a rotary spray type spray dryer can be used. Generated 5-5
The particle size distribution of the 0 μm barium titanate-based semiconductor ceramic material powder can be sharpened by means such as classification as necessary. When the flash drying method is employed, it is difficult to obtain a barium titanate-based semiconductor ceramic material powder having a particle diameter of 5 μm or less.

As described above, the trivalent or pentavalent semiconducting element is contained in an amount of 0.05 to 2 atomic% with respect to titanium, and the base material has a particle diameter of 0.3 of ATiO _3. ~ 50
A spherical barium titanate-based semiconductor porcelain material powder of μm is obtained.

In the present invention, the particle diameter of the spherical barium titanate-based semiconductor porcelain material powder is specified to be 0.3 to 50 μm, for the following reason. That is, when the particle diameter is smaller than 0.3 μm, the dispersibility in the binder during molding before forming into a ceramic is poor, and it is difficult to obtain a molded body having a uniform composition. Further, when the particle diameter is 50
When it is larger than μm, a portion having a grain size of 50 μm or more is formed when ceramics is formed, and the electrical characteristics and mechanical characteristics of the obtained semiconductor ceramic deteriorate.

The spherical barium titanate-based semiconductor porcelain material powder of the present invention is literally spherical in shape, has a narrow particle size distribution, and is excellent in dispersibility. A semiconductor ceramic such as a PTC thermistor and a semiconductor capacitor having excellent electrical characteristics and mechanical characteristics with little variation in grain size can be obtained.

As described above, the spherical barium titanate-based semiconductor ceramic material powder of the present invention can be used as it is as a raw material for semiconductor ceramics such as PTC thermistors and semiconductor capacitors. When the semiconductor ceramic material powder is calcined, the sintering is small, the crystallinity is good, the particle size and shape of the spherical barium titanate-based semiconductor ceramic material powder before calcining are maintained, the particle size distribution is narrow, and the dispersion is high. A cubic spherical barium titanate-based semiconductor ceramic material powder or a tetragonal spherical barium titanate-based semiconductor ceramic material powder is obtained.

The calcination of the spherical barium titanate-based semiconductor porcelain material powder of the present invention can be performed at a temperature of 300 to 1350 ° C. It is suitable to calcine at.

Further, by calcining the spherical barium titanate-based semiconductor ceramic material powder of the present invention at 1000 to 1200 ° C., it is possible to obtain a semiconductive powder having a spherical shape. By using this spherical semiconductive powder, the reaction between the sintering aid and the grain boundary layer component and the semiconductive element or barium titanate is suppressed, and it is easy to obtain a more sophisticated semiconductive porcelain. Become.

These spherical barium titanate-based semiconductor porcelain material powders have a narrower particle size distribution and are more spherical than conventional barium titanate-based semiconductor porcelain material powders obtained by a solid phase method or a wet method. In addition, there is also an effect that the amount of air entrained during molding is small, and thus the occurrence of lamination is suppressed, and it is possible to obtain a molded body having a uniform and high density as compared with the conventional barium titanate-based semiconductor ceramic material powder. It is possible, and the ultimate density of the sintered body is greatly improved.

Accordingly, by using the above-mentioned spherical barium titanate-based semiconductor ceramic material powder, a PTC thermistor having a uniform grain size and excellent in specific resistance-temperature characteristics and a semiconductor capacitor having a large dielectric constant and a small dielectric loss can be obtained. be able to.

Further, when the spherical barium titanate-based semiconductor porcelain material powder of the present invention is calcined at 900 to 1350 ° C., a rectangular parallelepiped barium titanate-based semiconductor porcelain material powder which is single-crystallized in units of particles can be obtained.

Since the barium titanate-based semiconductor ceramic material powder before calcination is also spherical, the sintering during calcination is small, and therefore the particles before calcination are also small. The diameter is almost maintained, the particle size distribution is narrow, and the dispersibility is excellent.

The cuboidal barium titanate-based semiconductor porcelain material powder is a high-density barium titanate-based semiconductor porcelain material powder which is more compact than the spherical barium titanate-based semiconductor porcelain material powder. Strict control of the size and grain boundary can be more easily performed. Therefore, by using this rectangular parallelepiped barium titanate-based semiconductor ceramic material powder, a PTC having a low specific resistance at room temperature and a large rate of change in resistance is used.
It is possible to more easily obtain a thermistor, a semiconductor capacitor having a large dielectric constant, a small dielectric loss, and a good withstand voltage characteristic.

[0088]

The spherical barium titanate-based semiconductor porcelain material powder of the present invention can be controlled to a desired particle size, has a narrow particle size distribution, is spherical in shape, and has excellent dispersibility.

Therefore, by using the spherical barium titanate-based semiconductor ceramic material powder of the present invention, a PTC thermistor having a desired grain size, a small variation in the grain size, and excellent electrical and mechanical properties can be obtained. A semiconductor porcelain such as a semiconductor capacitor can be obtained.

By calcining the spherical barium titanate-based semiconductor porcelain material powder of the present invention, sintering is reduced, and the particle diameter and shape of the spherical barium titanate-based semiconductor porcelain material powder before calcination are substantially maintained. A cubic spherical barium titanate-based semiconductor ceramic material powder or a tetragonal spherical barium titanate-based semiconductor ceramic material powder having a narrow particle size distribution and excellent dispersibility can be obtained.

The cubic spherical barium titanate-based semiconductor porcelain material powder and the tetragonal spherical barium titanate-based semiconductor porcelain material powder have good crystallinity, and can easily control the grain size and the grain boundary, and can improve the characteristics. Excellent PTC thermistors and semiconductor capacitors can be obtained.

Further, by calcining the spherical barium titanate-based semiconductor ceramic material powder of the present invention at a high temperature, a single-crystal rectangular parallelepiped barium titanate-based semiconductor ceramic material powder having less sintering and a narrow particle size distribution can be obtained. Obtainable.

Since the rectangular parallelepiped barium titanate-based semiconductor porcelain material powder is a high-density barium titanate-based semiconductor porcelain material powder which is more compact than the spherical barium titanate-based semiconductor porcelain material powder, the grain size of the porcelain is reduced. And strict control of the grain boundary can be more easily performed. By using the rectangular parallelepiped barium titanate-based semiconductor ceramic material powder, it is possible to obtain a PTC thermistor, a semiconductor capacitor, and the like having more excellent characteristics. .

[0094]

Next, the present invention will be described more specifically with reference to examples.

Example 1 An aqueous solution of titanium tetrachloride containing yttrium containing 0.3 atomic% of yttrium nitrate relative to titanium (manufactured by Osaka Titanium Co., containing 16.4% of titanium) was hydrolyzed with 15% aqueous ammonia. The obtained gel was filtered and washed with water to obtain a titanium hydroxide cake [I] containing 0.3 atomic% of yttrium having a titanium oxide concentration of 12.3% in terms of weight by ignition loss.

81 g of 30% hydrogen peroxide was added to a suspension of 72 g of the titanium hydroxide cake [I] containing 0.3 atomic% of yttrium uniformly dispersed in 380 g of water. At this time, the molar ratio of hydrogen peroxide to titanium oxide [hereinafter referred to as “H ₂ O ₂ / TiO ₂ (molar ratio)”] is 6.
35. The titanium oxide concentration in the obtained slurry was calculated as 70% of 30% hydrogen peroxide solution as water.
It was 225 mol / l.

The temperature of the obtained slurry was gradually increased while stirring, and the slurry was refluxed at 100 ° C. for 2 hours to obtain a suspension solution [I
I] was obtained. This suspension solution [II] was cooled to 4
The temperature was lowered to 0 ° C., nitrogen gas was blown into the air to replace the air, and 56.8 barium hydroxide / octahydrate was added to the suspension [II].
g [Ba / Ti (atomic ratio) = 1.6].
To 70 ° C. for 0.25 hours, aged at 70 ° C. for 3 hours, and then refluxed at 100 ° C. for 4 hours to terminate the reaction.

The barium titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium produced by this reaction is a spherical particle having a 90% number distribution particle diameter of 1.2 to 1.4 μm by observation with an electron microscope. The distribution was narrow and the average particle size was 1.3 μm.

FIG. 1 is an electron micrograph (magnification: 15,000 times) showing the particle structure of the spherical barium titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium produced in Example 1. As shown in FIG. 1, the spherical barium titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium produced in Example 1 has a spherical particle shape even when magnified 15,000 times. Further, it can be seen that the particle diameter is almost uniform and the particle size distribution is narrow.

Example 2 Antimony pentachloride was added in an amount of 0.1 as antimony to titanium.
An aqueous solution of titanium tetrachloride to which 25 atomic% is added is hydrolyzed with 15% aqueous ammonia, and the obtained gel is filtered, washed with water, and has a titanium oxide concentration of 24.
A 5% antimony 0.25 atomic% titanium hydroxide cake was obtained.

112.5 g of 30% hydrogen peroxide [H ₂ O was added to a suspension of 51.7 g of titanium hydroxide cake containing 0.25 atom% of antimony uniformly dispersed in 382 g of water.
₂ / TiO ₂ (molar ratio) = 6.26] to obtain a slurry having a titanium oxide concentration of 0.312 mol / l.

The obtained slurry was refluxed at 100 ° C. for 2 hours to obtain a suspension solution. After the suspension was cooled to 40 ° C., 69 g of barium hydroxide / octahydrate was added to the suspension.
[Ba / Ti (atomic ratio) = 1.4] was added thereto, and an aging reaction was performed at 70 ° C. for 3 hours, followed by refluxing at 100 ° C. for 4 hours to terminate the reaction.

The obtained barium titanate semiconductor ceramic material powder containing 0.25 atomic% of antimony has a 90% number distribution particle diameter of 0.6 to 0.8 μm as observed by an electron microscope.
Spherical particles with a narrow particle size distribution and an average particle size of 0.7μ
m.

The spherical particles obtained as described above are acid-treated with acetic acid, adjusted to Ba / Ti (atomic ratio) = 1.014, and calcined at 1100 ° C. to maintain the spherical shape. A conductive powder was obtained.

Example 3 Strontium titanate, calcium titanate and lead titanate were produced by the following method, and this was added at the time of producing the same yttrium-containing barium titanate semiconductor ceramic material powder as in Example 1 to obtain yttrium. A powder of a barium strontium calcium lead titanate-containing semiconductor ceramic material was produced.

Production of strontium titanate To 23 liters of distilled water, 1 kg of an aqueous solution of titanium tetrachloride (titanium content in the aqueous solution: 16%) was added while stirring.
% Ammonia water was added to hydrolyze to pH 8 and filtered and washed with water. The obtained titanium hydroxide gel is slurried to a slurry of 5% in titanium oxide content, heated to 60 ° C., and then added with acetic acid to pH 6,
While maintaining the pH and temperature, the mixture was stirred for 1 hour. This slurry was filtered and washed with water to obtain a titanium hydroxide gel having a titanium oxide concentration of 10.3% in terms of weight by ignition loss.

300 g of distilled water was added to 777 g (1 mol in terms of titanium oxide) of titanium hydroxide gel having a titanium oxide concentration of 10.3%, and the mixture was stirred in a nitrogen atmosphere and heated to 80 ° C. to obtain a titanium oxide slurry. I got

Separately, strontium hydroxide was dissolved in a nitrogen atmosphere to obtain a strontium content of 10.5%.
% Of an aqueous solution (containing 1.2 mol of strontium) and heated to 80 ° C., and the above titanium oxide slurry and the aqueous strontium solution have an atomic ratio of strontium to titanium [Sr / Ti (atomic ratio)]. Was adjusted to 1.2, and the mixture was added simultaneously while being kept at 80 ° C. in a nitrogen atmosphere, and stirred for 2 hours to carry out a reaction.

Thereafter, the temperature was raised to 100 ° C. or higher, and 1
After stirring for an hour, filtration and water washing were performed. The obtained strontium titanate was uniform fine particles having a particle size of 0.02 to 0.04 μm.

Production of calcium titanate 100.09 g of commercially available calcium carbonate is pulverized by a ball mill to a particle size of 0.1 μm or less, and 79.9 g of titanium oxide (rutile type, particle size: 0.1 μm) is added thereto.
After crushing and mixing for an hour, the mixture was spray-dried with a spray drier. This is calcined (reaction) at 1000 ° C. for 2 hours,
Calcium titanate having a particle size of 0.2 μm was obtained.

Production of Lead Titanate 292 g (1 mol in terms of titanium oxide) of titanium tetrachloride aqueous solution ( manufactured by Osaka Titanium Co., 16% titanium content, 32% chlorine content) was placed in a beaker, and water was added thereto. 1
The resulting aqueous slurry was gradually dropped into 1 liter of 9% aqueous ammonia, and the resulting white slurry was filtered and washed with water to obtain a titanium hydroxide cake. This was transferred to a plastic pot, and 223 g (1 mol) of commercially available lead monoxide and a diameter of 5 m
Then, 3 kg of yttria-stabilized zirconia balls of m. m was added, and 1 liter of water was further added. The mixture was sealed, and mixed with a ball mill for 3 hours.

The zirconia balls were removed from the obtained slurry, the slurry was spray-dried with a spray drier, and the obtained powder was dried at 100 ° C. for 12 hours to obtain a lead titanate precursor (particle diameter 0.2 μm). I got This is 4
By calcining at 90 ° C. for 5 hours, the particle size is 0.1 μm
Of fine particles of lead titanate were obtained.

Spherical barium titanate containing yttrium
Manufacture of trontium calcium lead semiconductor porcelain material powder

Hydrogen peroxide solution was added to the titanium hydroxide cake [I] containing 0.3 atomic% of yttrium prepared in Example 1 in the same manner as in Example 1, and the same treatment was carried out.
A suspension solution [II] similar to the above was obtained.

After the suspension solution [II] was cooled to 40 ° C. or less, nitrogen gas was blown in to replace the air, and the strontium titanate produced as described above (particle size: 0.
02-0.04 μm), calcium titanate (particle diameter 0.2 μm) and lead titanate (particle diameter 0.1 μm)
The molar ratio of each of titanium oxide, strontium titanate, calcium titanate and lead titanate is Ti
O ₂ : SrTiO ₃ : CaTiO ₃ : PbTiO ₃ = 8
0: 9: 4: 7 was added and mixed uniformly.

Barium hydroxide / octahydrate was added to the obtained slurry so that Ba / Ti (atomic ratio) = 1.6 and mixed, and the same as in Example 1, 30 ° C. to 70 ° C. The temperature was raised in 0.25 hours until aging at 70 ° C. for 3 hours, and then refluxed at 100 ° C. for 4 hours.

The obtained reaction mixture was filtered, washed with water, and adjusted to (Ba + Sr + Ca + Pb) / Ti (atomic ratio) = 0.994 by adding acetic acid.

The obtained barium strontium calcium lead semiconductor ceramic material powder containing 0.3 atomic% of yttrium has a composition excluding yttrium content by X-ray fluorescence analysis (Ba _0.80 Sr _0.09 Ca _0.04 Pb _0.07 ).
TiO ₃ having a 90% number distribution particle size of 0.4 to 0.6 μm by electron microscope observation, a narrow particle size distribution,
The average particle size was 0.5 μm.

FIG. 2 is an electron micrograph (magnification: 15,000) showing the particle structure of the spherical barium strontium calcium lead semiconductor powder containing 0.3 atomic% of yttrium produced in Example 3. . As shown in FIG. 2, the barium strontium calcium lead semiconductor powder containing 0.3 atomic% of yttrium produced in Example 3 has a spherical particle shape even when magnified 15,000 times. Also, it can be seen that the particle size is almost uniform and the particle size distribution is narrow.

Example 4 2390 g of titanium hydroxide cake [I] containing 0.3 atomic% of yttrium prepared in Example 1 (0.1% as titanium content)
10 mol of water (containing 8% as titanium oxide) and a 30% aqueous barium hydroxide solution 9710 prepared and boiled in a nitrogen atmosphere.
g (containing 1.7 mol as barium content) at 100 ° C.
The mixture was mixed through an in-line mixer kept warm, and reacted under reflux for 4 hours.

The slurry after the reaction was filtered and washed with water to obtain crystalline barium titanate containing 0.3 atomic% of yttrium having a particle diameter of 0.01 μm or less.

Acetic acid is added to the obtained crystalline barium titanate containing 0.3 atomic% of yttrium, followed by acid treatment.
a / Ti (atomic ratio) = adjusted crystalline barium titanate 100 containing 0.3 atomic% of yttrium 100
g, 9.59 g of strontium titanate and 12.68 g of lead titanate, the production method of which was described in Example 3, were added, mixed uniformly by a ball mill, and spray-dried with a spray dryer manufactured by Okawara Kakoki Co., Ltd. 800 ° C
After calcination for 2 hours, the particles are classified by a wet method using sieves of 500 mesh and 325 mesh to obtain a particle size of 30.
４５45 μm was obtained.

The obtained granules were placed in a closed vessel at 800 ° C. for 2 hours.
After calcining for a time, a powder having a relatively uniform particle diameter of 37 μm and a good dispersibility was obtained.

According to quantitative analysis by fluorescent X-ray, the obtained powder had a composition excluding yttrium (Ba _0.82 S
r _0.10 Pb _0.08 ) TiO _3, which was barium strontium lead titanate containing 0.3 atomic% of yttrium.

FIG. 3 is a magnification of 90 showing the particle structure of the barium strontium lead titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium produced in Example 4.
It is an electron microscope photograph of 0 time. As shown in FIG.
The barium strontium lead titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium produced in Example 4 had a spherical particle shape even when enlarged 900 times, and had a substantially uniform particle diameter. It can be seen that the particle size distribution is narrow.

Example 5 81 g of 30% hydrogen peroxide was added to a suspension prepared by uniformly dispersing 72 g of titanium hydroxide cake [I] containing 0.3 atomic% of yttrium prepared in Example 1 in 380 g of water. At this time, the molar ratio of hydrogen peroxide to titanium oxide [H ₂
O ₂ / TiO ₂ (molar ratio)] was 6.35, and the concentration of titanium oxide in the obtained slurry was 0.225 ml / l.

The temperature of the obtained slurry was gradually increased while stirring, and a reflux treatment was performed at 100 ° C. for 2 hours to obtain a suspension solution. After lowering the suspension to 40 ° C. or lower, nitrogen gas was blown in to replace the air, and barium hydroxide was added to the suspension so that the molar ratio of barium hydroxide to strontium hydroxide was 8: 2. After adding 51.10 g of octahydrate and 10.76 g of strontium hydroxide and octahydrate, the temperature was raised from 30 ° C. to 70 ° C. in 0.25 hours, and after aging at 70 ° C. for 3 hours, The reaction was terminated by refluxing at 100 ° C. for 4 hours. The atomic ratio of (Ba + Sr) / Ti at the time of the reaction was 1.8.

The barium / strontium titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium produced by this reaction had a Ba / Sr (atomic ratio) of 7/3, and the proportion of strontium was increased. Further, the obtained barium strontium titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium was spherical with a particle diameter of about 0.4 μm as shown in FIG.

From the above results, it is clear that strontium reacts preferentially to titanium in the production of barium strontium titanate. Therefore, in consideration of this fact, the amount of strontium suitable for Ba / Sr should be determined. Can be.

Example 6 A slurry obtained by adding water to the titanium hydroxide cake [I] containing 0.3 atomic% of yttrium prepared in Example 1 and uniformly mixing the mixture (containing 1.8% as titanium oxide) with water was added. Barium oxide / octahydrate was mixed so that Ba / Ti (atomic ratio) = 1.2, and reacted at 100 ° C. for 4 hours while refluxing.

The obtained slurry was filtered, washed with water, acid-treated with acetic acid, and calcined at 800 ° C. for 2 hours to obtain Ba / Ti
Spherical particles of barium titanate containing 0.3 atomic% of yttrium and having an atomic ratio of 0.992 and a particle diameter of 0.1 μm were obtained.

Separately from the above, the agglomerated particles of barium titanate containing 0.3 atomic% of yttrium having a particle diameter of 1.2 to 1.4 μm obtained in Example 1 were subjected to an acid treatment in the same manner as described above. After adjusting to Ba / Ti (atomic ratio) = 0.992, it was calcined at 1000 ° C for 2 hours to obtain a particle diameter of 1.2 to 1.
Barium titanate containing 4 atm of 0.3 atomic% of spherical yttrium was obtained.

The barium titanate particles containing 0.3 atomic% of yttrium having a particle diameter of 0.1 μm and a particle diameter of 1.2
Barium titanate particles containing 0.3 atomic% of yttrium of 0.3 to 1.4 μm are uniformly mixed at a weight ratio of 3: 7 by a ball mill using resin balls, and 0.04 mol% of manganese nitrate and 0.1 fine particles of silicon dioxide
5 mol% was added and mixed with a ball mill, and the mixture was added with 0.4% by weight of polyvinyl alcohol as a binder and 0.1% of polyethylene glycol as a deflocculant.
4% by weight was added and granulation was performed by spray drying with a spray dryer to obtain granules having a particle diameter of 30 μm.

The obtained granules are put into a forming die, and pressurized at 1 ton / cm ² to form a cylinder having a diameter of 15 mm.
It was fired at 1250 ° C. to obtain a semiconductor porcelain. The grain size (particle diameter) in this semiconductor porcelain was almost uniform at 2 to 4 μm.

FIG. 7 shows the specific resistance-temperature characteristics of this porcelain. FIG. 7 will be described in detail after Comparative Example 2.

Comparative Example 1 In Comparative Example 1, 0.22 atomic% of niobium was obtained by the solid phase method.
A barium titanate containing iron is produced, and variations in the particle shape and particle diameter are clarified.

That is, commercially available barium carbonate 98.66
g, titanium oxide 40.34 g and niobium pentoxide 0.1
462 g were uniformly mixed with a ball mill for 30 minutes, and spray-dried with a spray drier.
/ Cm ² and calcined at 1150 ° C. for 2 hours to obtain a barium titanate semiconductor ceramic material powder containing 0.22 atomic% of niobium.

An electron microscope photograph of the obtained barium titanate semiconductor ceramic material powder containing 0.22 atomic% of niobium at a magnification of 10,000 is shown in FIG.

As shown in FIG. 5, the barium titanate containing 0.22 atomic% of niobium obtained by the solid phase method had a non-uniform particle shape and a large variation in particle diameter.

Comparative Example 2 In Comparative Example 2, a barium titanate semiconductor ceramic material powder containing 0.3 atomic% of yttrium was produced by a wet method, and variations in particle shape and particle diameter were clarified.

That is, a titanium hydroxide cake [I] containing 0.3 atomic% of yttrium obtained by the same method as in Example 1 (titanium oxide concentration 2 in terms of weight by ignition loss)
2.8%) Nitrogen gas was passed through 390 g of the slurry to
The mixture was heated to 0 ° C. and 428 g of barium hydroxide / octahydrate [B
a / Ti (atomic ratio) = 1.2], followed by stirring and uniform mixing.

This slurry was further heated and refluxed at 100 ° C. for 4 hours (nitrogen gas was stopped when the temperature was raised), filtered, washed with water, and spray-dried with a spray drier.
A barium titanate powder containing 0.3 atomic% of yttrium was obtained. In addition, Ba / Ti (atomic ratio) at the time of reaction was 1.2.

The obtained barium titanate powder containing 0.3 atomic% of yttrium was calcined at 800 ° C. for 5 hours, and then acid-treated with acetic acid to obtain a semiconductor material.
(Atomic ratio) was adjusted to 0.992.

Barium titanate powder containing 0.3 atomic% of yttrium after acid treatment [Ba / Ti (atomic ratio) = 0.9
92] was calcined again at 800 ° C. for 2 hours to give a particle size of 0.1.
Particles having a uniform particle diameter of 03 to 0.06 μm were obtained.

However, when the same acid-treated powder was calcined at 1200 ° C. for 3 hours, the particle size increased to 0.06 to 1 μm, but the particle shape was changed as shown in FIG. 6 (FIG. (Electron micrograph) as shown in FIG.

Next, as described above, particles having different particle diameters are used.
The calcined powder at 0 ° C. and the calcined powder at 1200 ° C. are mixed at a weight ratio of 3: 7, and 0.04 mol% of manganese nitrate and 0.15 mol% of fine silicon dioxide are added thereto. The mixture was mixed, and 0.4% by weight of polyvinyl alcohol as a binder and 0.4% by weight of polyethyl glycol as a peptizer were added to the mixture, followed by granulation by spray drying with a spray drier.

The obtained granules were put into a molding die, pressed at 1 ton / cm ² to form columnar pellets having a diameter of 15 mm, and fired at 1250 ° C. to obtain semiconductor porcelain. The grain size in this semiconductor porcelain was 5 to 10 μm.

FIG. 7 shows the specific resistance-temperature characteristics of the obtained semiconductor porcelain.

In FIG. 7, the curve “a” represents the sixth embodiment of the present invention.
Shows the specific resistance-temperature characteristics of a semiconductor porcelain made of a spherical barium titanate semiconductor porcelain material powder containing 0.3 atomic% of yttrium produced by the above method. Curve b is obtained by the wet method in Comparative Example 2 described above. Yttrium
3 shows the specific resistance-temperature characteristics of a semiconductor porcelain made of a barium titanate semiconductor porcelain material powder containing 3 atomic%.

As is clear from the comparison between the curves a and b in FIG. 7, the semiconductor porcelain made from the barium titanate semiconductor porcelain material powder containing 0.3 atomic% of yttrium produced in Example 6 of the present invention. Has a lower specific resistance at room temperature and a wider range of resistance change than the semiconductor porcelain made of the barium titanate semiconductor porcelain material powder containing 0.3 at% yttrium manufactured by the wet method of Comparative Example 2. .

[Brief description of the drawings]

FIG. 1 shows yttrium 0.3 produced according to Example 1.
5 is an electron micrograph (magnification: 15,000 times) showing the particle structure of an atomic% spherical barium titanate semiconductor ceramic material powder.

FIG. 2 shows yttrium 0.3 produced according to Example 3.
Magnification 1.5 showing the particle structure of spherical barium strontium calcium lead zinc semiconductor ceramic material powder containing atomic%
It is an electron microscope photograph of ten thousand times.

FIG. 3 shows yttrium 0.3 produced according to Example 4.
It is an electron micrograph at 900 times magnification which shows the particle structure of the spherical barium strontium lead titanate semiconductor ceramic material powder containing atomic%.

FIG. 4 shows yttrium 0.3 produced according to Example 5.
It is an electron micrograph at 15,000 times magnification which shows the particle structure of spherical barium strontium titanate containing atomic%.

FIG. 5 shows niobium produced by the solid-phase method of Comparative Example 1.
It is an electron microscope photograph at 10,000 times magnification which shows the particle structure of the barium titanate semiconductor ceramic material powder containing 22 atomic%.

FIG. 6 is an electron micrograph (magnification: 15,000 times) showing the particle structure of a barium titanate semiconductor ceramic material powder containing 0.3 at% yttrium produced by the wet method of Comparative Example 2.

FIG. 7 shows yttrium 0.3 produced according to example 6.
Specific resistance-temperature characteristics of a semiconductor porcelain made of a spherical barium titanate semiconductor porcelain material powder containing at.%, And 0.3 at.% Of yttrium produced by the wet method of Comparative Example 2.
It is a figure which shows the specific resistance-temperature characteristic of the semiconductor porcelain produced with the containing barium titanate semiconductor porcelain material powder.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI H01L 41/04 H01L 41/04 41/24 41/22 A (72) Inventor Masanori Kinugasa 1-3-47 Funamachi, Taisho-ku, Osaka-shi No. Takeka Co., Ltd. (58) Fields surveyed (Int. Cl. ⁷ , DB name) C01G 23/00 C04B 35/46 H01C 7/02 H01G 4/12 415 H01L 37/00 H01L 41/04 H01L 41 / twenty four

Claims (11)

(57) [Claims] A trivalent or pentavalent semiconducting element is contained in an amount of 0.05 to 2 atomic% based on titanium, and the base material portion thereof is formed of AT.
iO ₃ (A is Ba ≧ 50 at%, 0 at% ≦ Sr, C
a, Pb ≦ 50 atomic%)
μm spherical barium titanate-based semiconductor porcelain material powder. 2. The spherical barium titanate-based semiconductor ceramic material powder according to claim 1, wherein the ATiO ₃ is BaTiO ₃ . 3. A spherical barium titanate-based semiconductor ceramic material powder having a particle diameter of 0.3 to 50 μm obtained by calcining the spherical barium titanate-based semiconductor ceramic material powder according to claim 1 at 300 to 1200 ° C. 4. The method according to claim 1, wherein hydrogen peroxide and a semiconducting agent coexist during a wet reaction between the titanium compound and the barium compound or during a wet reaction between the titanium compound and the barium compound and the strontium compound. .3
The method for producing a spherical titanium barium-based semiconductor porcelain material powder according to claim 1, having a thickness of from 5 to 5 µm. 5. Hydrogen peroxide, a semiconducting agent, and titanic acid having a particle diameter of 0.2 μm or less during a wet reaction between a titanium compound and a barium compound or during a wet reaction between a titanium compound and a barium compound or a strontium compound. 2. The spherical barium titanate according to claim 1, wherein at least one selected from the group consisting of strontium, calcium titanate having a particle diameter of 0.2 μm or less, and lead titanate having a particle diameter of 0.2 μm or less coexists. Manufacturing method of semiconductor porcelain material powder. 6. The titanium compound is a titanium hydroxide containing a semiconducting element or a titanium oxide containing a semiconducting element,
The barium compound is barium hydroxide, and before reacting the titanium compound with the barium compound, reacting titanium hydroxide containing a semiconducting element or titanium oxide containing semiconducting element with hydrogen peroxide. The method for producing a spherical barium titanate-based semiconductor ceramic material powder according to claim 4 or 5, wherein: 7. The titanium compound is a titanium hydroxide containing a semiconducting element or a titanium oxide containing a semiconducting element, the barium compound is barium hydroxide, the strontium compound is strontium hydroxide, and the titanium compound is a titanium compound. 6. A reaction between titanium oxide containing a semiconducting element or titanium oxide containing a semiconducting element and hydrogen peroxide before the reaction of the compound with a barium compound and a strontium compound. A method for producing a spherical barium titanate-based semiconductor porcelain material powder according to the above. 8. The aging reaction of a titanium compound with a barium compound or the aging reaction of a titanium compound with a barium compound and a strontium compound at 40 to 100 ° C. for at least 30 minutes or more. A method for producing the barium titanate-based semiconductor porcelain material powder according to the above. 9. A wet reaction between a titanium compound and a barium compound, or a wet reaction between a titanium compound, a barium compound and a strontium compound, wherein a semiconducting agent is allowed to coexist, and after the reaction, flash drying is performed. Particle size 5
The method for producing a spherical barium titanate-based semiconductor porcelain material powder according to claim 1, having a thickness of from 50 to 50 m. 10. A wet reaction between a titanium compound and a barium compound, or a wet reaction between a titanium compound, a barium compound and a strontium compound, in which a semiconducting agent and hydrogen peroxide are allowed to coexist, followed by flash drying. The method for producing a barium titanate-based semiconductor ceramic material powder according to claim 1, wherein the particle diameter is 5 to 50 µm. 11. A semiconducting agent, strontium titanate having a particle diameter of 0.2 μm or less, or a strontium titanate having a particle diameter of 0.2 μm or less during a wet reaction between a titanium compound and a barium compound or a wet reaction between a titanium compound and a barium compound or a strontium compound. A particle diameter of 5 to 50 μm, characterized by coexisting at least one selected from the group consisting of calcium titanate of 0.2 μm or less and lead titanate of 0.2 μm or less in particle size, followed by flash drying after the reaction. Item 4. The method for producing a spherical barium titanate-based semiconductor ceramic material powder according to Item 1.