CN113939476B

CN113939476B - Barium titanate particles, method for producing same, and dispersion of barium titanate particles

Info

Publication number: CN113939476B
Application number: CN202080042148.5A
Authority: CN
Inventors: 渡边和马; 熊泽光章; 村口良
Original assignee: JGC Catalysts and Chemicals Ltd
Current assignee: JGC Catalysts and Chemicals Ltd
Priority date: 2019-09-30
Filing date: 2020-09-30
Publication date: 2024-05-14
Anticipated expiration: 2040-09-30
Also published as: JPWO2021066070A1; WO2021066070A1; TW202116682A; CN113939476A; KR20220074821A

Abstract

The invention provides barium titanate particles with high sintering delay effect and a manufacturing method thereof. The atomic ratio Ba/Ti of the barium titanate particles with perovskite structure is 0.95-1.05, and the crystallite diameter is 5-25 nm.

Description

Barium titanate particles, method for producing same, and dispersion of barium titanate particles

Technical Field

The present invention relates to barium titanate particles having a perovskite structure.

Background

Barium titanate particles are used for dielectric materials for electronic parts, optical materials having a high refractive index and excellent transparency, and the like. Barium titanate particles are used for laminated ceramic capacitors (MLCCs) because of their high dielectric constant. The MLCC has a structure in which electrode layers and dielectric layers are alternately stacked. The electrode layer contains Ni particles of 80 to 300nm and barium titanate particles as a co-material. In the electrode layer, barium titanate particles are filled around the Ni particles. Therefore, the temperature at which the Ni particles sinter with each other becomes high. That is, the effect of the sintering delay of the Ni particles can be obtained. Therefore, the temperature at which the Ni particles sinter with each other and the temperature at which the dielectric layer sinter become close. Thus, the difference in shrinkage rates between the electrode layer and the dielectric layer is reduced during firing, and an MLCC with fewer cracks (cracks) can be obtained (see, for example, patent document 1).

On the other hand, in order to increase the dielectric constant of barium titanate particles, it is known that: the barium titanate particles are made to have a perovskite structure, and the axial length of the c-axis of the crystal lattice is made longer than the axial length of the a-axis, that is, the barium titanate particles are made to have a tetragonal system. (for example, refer to patent document 2).

Prior art literature

Patent document 1: japanese patent laid-open publication No. 2005-63707

Patent document 2: japanese patent application laid-open No. 2004-300027

Disclosure of Invention

Technical problem to be solved by the invention

In the barium titanate particles of patent document 2, the c-axis length of the perovskite structure is longer than the a-axis length, and thus the dielectric constant is high. However, barium titanate particles are easily increased in particle diameter and crystallite diameter because they are sintered after being powdered. Therefore, the density of barium titanate particles filled around the Ni particles tends to be low, and it is difficult to obtain a sintering delay effect. The larger the difference between the temperature at which the dielectric layer is sintered and the temperature at which the Ni particles are sintered, the more likely the MLCC will crack.

The purpose of the present invention is to provide barium titanate particles having a high sintering delay effect, and a method for producing the same.

Technical means for solving the technical problems

Therefore, in the present invention, in the perovskite barium titanate particles, the atomic ratio Ba/Ti of barium to titanium is set to 0.9 to 1.1, and the crystallite diameter is set to 5 to 25nm. The atomic ratio Ba/Ti of barium to titanium may be 0.95 to 1.05.

Further, the ratio c/a of the length of the c-axis to the a-axis of the perovskite structure lattice is preferably 1.005 or less.

Preferably, the water content in the dispersion liquid of barium titanate particles containing such barium titanate particles and an organic solvent is less than 3% by weight.

The method for producing barium titanate particles includes: a step of mixing a barium hydroxide with an alkyl cellosolve; a step of adding a titanium alkoxide so that the atomic ratio Ba/Ti of barium to titanium is in the range of 0.9 to 1.1; a step of adding water; and a heating step.

Drawings

FIG. 1 is a structural diagram of a cyclic hydrocarbon group (R ₆).

Detailed Description

The barium titanate particles of perovskite structure of the present invention have an atomic ratio Ba/Ti of barium to titanium in the range of 0.9 to 1.1. This makes it difficult to produce impurities such as crystals other than the perovskite structure. The crystallite diameter of the barium titanate particles is 5 to 25nm. Therefore, the barium titanate particles have high crystallinity and small particle size. Since such barium titanate particles enter the gaps of the Ni particles in the electrode layer, the barium titanate particles exist in the periphery of the Ni particles at a high density. Therefore, the sintering delay effect of Ni becomes high. If the crystallite diameter is larger than 25nm, the viscosity of a dispersion of barium titanate particles to be described later becomes high. When the crystallite diameter is 5 to 25nm, the particle diameter measured by a transmission electron microscope is also 5 to 25nm.

The atomic ratio Ba/Ti of barium to titanium may be 0.95 to 1.05.

Further, the ratio (axial ratio) c/a of the length of the c-axis to the a-axis of the perovskite structure lattice is preferably 1.005 or less. Thereby, the barium titanate particles become close to cubic crystals. Therefore, the sintering delay effect of Ni becomes high.

The crystal structure and crystallite diameter can be measured using RINT-Ultima manufactured by Rigaku, which is an X-ray diffraction measuring apparatus. The crystalline structure can be identified using PDXL as analytical software. Crystallite diameter can be calculated from half width β (rad) by measuring half width at miller index (110) around 2θ=31.5°, using the Scherrer equation "d=kλ/βcosθ". Here, D represents the crystallite diameterK represents a Shelle constant, and lambda represents the wavelength/>Θ represents the reflection angle.

From the result of the X-ray diffraction measurement using PDXL, the lengths of the a-axis and the c-axis of the perovskite structure can be determined. The axial ratio c/a is preferably 1.003 or less. The axial ratio c/a is more preferably 1.001 or less. The smaller the axial ratio c/a, the higher the sintering delay effect of Ni becomes.

Preferably, the barium titanate particles contain at least one element (hereinafter referred to as an additive element) selected from group 2, group 3, lanthanoid, actinoid, group 4, group 5, group 6, group 7, group 8, group 9, group 10, group 11, group 12, group 13, and group 14. Thus, the sintering delay effect strain is high. When the composition formula BaTiO ₃ of barium titanate is set to 100mol%, it is more preferable to contain 0.1 to 10mol% of an additive element. Thus, the sintering delay effect of Ni is easily obtained. In addition, even if the additive element is contained in this range, no peaks other than the perovskite structure are observed.

Using the dispersion of barium titanate particles, a paste for printing an electrode layer can be prepared. The dispersion of barium titanate particles contains barium titanate particles and an organic solvent. The water content of the dispersion is preferably less than 3% by weight. If the amount of water is small, the viscosity of the slurry is less likely to increase even if a binder such as ethylcellulose is added to the dispersion. If the viscosity of the slurry is high, it is difficult to uniformly apply the slurry, and thus cracks are easily generated in the electrode layer at the time of firing. In addition, if the moisture content of the dispersion is 3 wt% or less, the dispersion becomes difficult to aggregate.

The amount of water adsorbed by the solid component of the dispersion (adsorbed water amount) is preferably 5 parts by mass or more with respect to 100 parts by mass of the solid component. If the amount of adsorbed water is within this range, the surface of the barium titanate particles in the dispersion will have hydroxyl groups. The dispersion was dried at 200℃for 3 hours to obtain a solid component. The adsorbed moisture amount is the moisture amount adsorbed to the solid component when the solid component is exposed to a condition of 25 ℃ and 90RH% for 1 hour.

The barium titanate particles are preferably not surface-treated. Thus, the viscosity of the slurry tends to be low. In particular, if the water content of the dispersion is 3% or less, the viscosity of the slurry tends to be further lowered. If barium titanate is surface-treated with a surface-treating agent of an organic acid system such as linoleic acid or oleic acid, there is a case where the viscosity of the slurry becomes high. However, if the viscosity of the slurry is not increased, the barium titanate particles may be surface-treated with a surface treatment agent.

The organic solvent preferably has an OH group. That is, it is preferable that the organic solvent has high hydrophilicity. Thus, the viscosity of the dispersion or slurry tends to be low. When the organic solvent has OH groups, if the amount of adsorbed water is 5 parts by mass or more per 100 parts by mass of the solid content, the viscosity of the dispersion tends to be low.

The organic solvent preferably has an OH group and at least one of an ester bond, an ether bond, and a ketone group. Thereby, the hydrophilicity of the organic solvent becomes higher. In particular, by having an ether bond, high hydrophilicity can be obtained.

Or it is preferable that the organic solvent has an OH group and has a hydrophobic structure. The hydrophobic structure herein means a cyclic structure or a chain structure in which 2 or more carbon atoms are continuously carbon-carbon bonded from the end. The cyclic structure may be a cyclic hydrocarbon group (R ₆).R₆ may be any cyclic hydrocarbon group such as a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, or a seven-membered ring) as a single substituent after removing a hydrogen atom from any carbon atom such as a cycloalkane, a cycloalkene (cycloolefin), or an aromatic ring (R ₆).R₆ may be any cyclic hydrocarbon group such as a three-membered ring, a four-membered ring, a five-membered ring, or a seven-membered ring) in FIG. 1, (a) is an aromatic ring of a six-membered ring, (b) is a cycloalkene of a six-membered ring, (c) is a cycloalkene of a six-membered ring.

Examples of the chain structure include a linear structure such as an alkyl group, and a branched structure such as an isopropyl group and a tert-butyl group. The organic solvent having a chain structure is represented by an expression R ₃-CR₄R₅-CH₃. In this expression, methyl (-CH ₃) is terminal. The carbon atom bound to the terminal methyl group is the second carbon atom from the terminal. That is, the carbon atom of the methyl group and the carbon atom bonded to the methyl group become continuously carbon-carbon bonded from the terminal. Here, R ₃、R₄ and R ₅ have a structure containing elements such as carbon, hydrogen, nitrogen, and oxygen. R ₃、R₄ and R ₅ may be bonded to each other to form a cyclic structure. If the organic solvent has a hydrophobic structure, it is considered that the compatibility of the organic solvent with the binder becomes high. If the organic solvent has a hydrophobic structure and an OH group, the organic solvent can improve the compatibility of the binder with the barium titanate particles. Thus, the slurry becomes difficult to aggregate. The number of carbon atoms of the chain structure which are continuously carbon-carbon bonded from the terminal is preferably 5 or less. Thereby, the hydrophilicity of the organic solvent becomes high. The number of carbon-carbon bonded carbon atoms is more preferably 4 or less. When the organic solvent has an ether bond, it is preferable that the alkyl group is bonded to an oxygen atom of the ether bond. The carbon atoms of the alkyl group are preferably 3 to 5.

The solubility parameter (SP value) of the organic solvent is preferably 8.5 or more. If it is 8.5 or more, the hydrophilicity of the organic solvent becomes high.

The boiling point of the organic solvent at atmospheric pressure is preferably 300 ℃ or lower. Thus, the carbon chain of the organic solvent is shortened compared to an organic solvent having a boiling point higher than 300 ℃. Thus, the viscosity of the dispersion decreases. In addition, since the viscosity of the paste for printing is also reduced, the paste for printing is easily and uniformly applied at the time of printing. The boiling point of the organic solvent at atmospheric pressure is preferably 200 to 300 ℃. Thus, when the slurry is applied and dried, the slurry tends to be uniformly dried in a state where the Ni particles and the barium titanate particles have been dispersed. Therefore, the sintering delay effect of the Ni particles becomes high. In addition, the MLCC becomes difficult to crack. If the organic solvent having a boiling point of 200 to 300 ℃ has an OH group, it becomes easy to mix the dispersion with the Ni particles. Thus, the slurry becomes difficult to aggregate. If the paste is difficult to aggregate, the paste is easily and uniformly dried, so that the printing performance can be improved. From the standpoint of boiling point and hydrophobic structure, butyl carbitol is preferred as the organic solvent.

The viscosity of the organic solvent is preferably 100 mPas or less at 25℃under atmospheric pressure. This can reduce the viscosity of the dispersion, and the viscosity of the printing paste can also be reduced.

Next, a method for producing barium titanate particles and a dispersion thereof will be described.

First, a mixture a is prepared by mixing a barium hydroxide with an alkyl cellosolve as a solvent (first step). By using the barium hydroxide, the counter ions do not diffuse into the dielectric layer when the electrode layer is baked. Therefore, the performance of the MLCC is easily increased. Since the solvent is an alkyl cellosolve, the viscosity of the dispersion decreases. In addition, the viscosity of the slurry becomes difficult to rise. The water content of the mixed solution a is preferably 5 mass% or less. Thus, when a titanium alkoxide described later is added, the titanium alkoxide becomes difficult to hydrolyze. Therefore, the particle size tends to be small. The mixed solution a may be depressurized or heated before the second step described later so that the water content of the mixed solution a becomes 5 mass% or less.

Next, a titanium alkoxide is added to the mixed solution a to prepare a mixed solution B (second step). The atomic ratio Ba/Ti of barium to titanium in the mixed solution B is preferably 0.95 to 1.05. If the content is within this range, it becomes difficult to produce crystals other than the perovskite structure. The atomic ratio of barium to titanium may be 0.9 to 1.1. It is preferable to add the titanium alkoxide under a nitrogen atmosphere. This reduces the reaction rate of the titanium alkoxide. Therefore, barium titanate particles having a small particle diameter and a small crystallite diameter can be easily obtained.

The structure of the titanium alkoxide is preferably "Ti (OR) ₄". Here, R is a hydrocarbon group having 1 to 4 carbon atoms or a substituted hydrocarbon group in which 1 or more hydrogen atoms are substituted with halogen atoms. R may be the same or different from each other. In such a structure, the crystallinity of the barium titanate particles tends to be high. Specifically, titanium methoxide, titanium ethoxide, titanium n-propoxide, titanium isopropoxide, titanium n-butoxide, titanium isobutanol, and the like can be mentioned.

Subsequently, water is added to the mixed solution B to prepare a mixed solution C (third step). The amount of water added is preferably equal to or more than the equivalent mole number relative to the titanium alkoxide. Thus, the titanium alkoxide remaining in the mixed solution C without hydrolysis is reduced. Therefore, the crystallinity of the barium titanate particles becomes high.

Subsequently, the mixture C is heated (fourth step). Preferably at 40 ℃ or higher for 2 to 200 hours. By this step, the aging is performed, and barium titanate particles are produced in the aged material. If the heating temperature is 40 ℃ or higher, the particle size distribution tends to be uniform although it also varies depending on the concentration of the gel. Further, crystallinity becomes good. In addition, the heating temperature of 120 ℃ or lower is industrially easy to handle. If heated for 2 hours or more, the particle size distribution tends to become uniform. In addition, crystallinity is easily improved. If the heating time is 200 hours or less, the particle diameter and crystallite diameter tend to be small. More preferably from 5 hours to 100 hours.

The cured product obtained in the fourth step is subjected to ultrafiltration or distillation (fifth step). When ultrafiltration or distillation is performed, the water content of the dispersion is adjusted to less than 3 wt%. The organic solvent may also be added before ultrafiltration or distillation. In the case where the boiling point of the organic solvent is lower than that of the alkyl cellosolve, ultrafiltration is preferable. Above alkyl cellosolves, distillation is preferred. Preferably, the organic solvent has the characteristics of the organic solvent described in the above description of the dispersion liquid.

The dispersion prepared by the above-described production method has a small water content. Therefore, the viscosity of the slurry becomes difficult to rise. The barium titanate particles in the dispersion have small particle diameters and small crystallite diameters, and have high crystallinity. Further, since the crystal system of barium titanate particles is close to cubic crystal system, the sintering delay effect of Ni becomes high when used for an electrode layer.

It is preferable that a metal salt containing at least one kind selected from group 2, group 3, lanthanoid, actinoid, group 4, group 5, group 6, group 7, group 8, group 9, group 10, group 11, group 12, group 13 and group 14 is added before the fourth step. By adding such a metal salt, the sintering delay effect strain is high. Further, since the metal salt is used, it becomes difficult to produce crystals other than the perovskite structure. Further, by adding a metal salt before the fourth step, the metal salt is dispersed in the gel of barium titanate. Therefore, the sintering delay effect is liable to become high.

Examples

The embodiments of the present invention are specifically described below. The preparation conditions of each example and comparative example are shown in table 1.

Example 1

< Preparation of Dispersion >

50G of barium hydroxide octahydrate (manufactured by Fuji photo-pure Co., ltd.) and 315g of 2-methoxyethanol (methyl cellosolve) were placed in a beaker, and dissolved at 30℃for 20 minutes. The Ba concentration of this solution was 6.0 wt% and the moisture content was 6.2 wt%. This solution was placed in a 1dm ³ eggplant-shaped flask, and distilled by a rotary evaporator to obtain a mixed solution A. The distillation conditions were carried out at a temperature of 70℃and a reduced pressure of 0.015MPa for 1 hour. The Ba concentration of the mixed solution a was 16.0 wt% and the moisture content was 0.5 wt%.

In a glove box under a nitrogen atmosphere, 56.18g of titanium isopropoxide (ORGATIX (registered trademark) TA-10, ti concentration 16.88 wt%) was mixed with 170g of the mixed solution A to prepare a mixed solution B.

In addition, a mixture of 57.1g of water and 171.2g of methanol was added over 1 minute. Stirring was carried out while maintaining at 25℃during the addition. Thus, the obtained hydrate gel was heated to 80℃and aged for 96 hours. The resulting cured product was subjected to ultrafiltration to obtain a dispersion containing 40 mass% of barium titanate.

The dispersion was measured as follows. The measurement results of each example and comparative example are shown in table 2.

< Measurement of moisture content >

The measurement was performed using a bench coulomb method moisture meter model CA-200 (Mitsubishi chemical analysis technology Co., ltd.).

< Measurement of adsorbed Water content >

30G of the dispersion was dried at 200℃for 3 hours and cooled in a dryer, whereby a dried powder was obtained. The dried powder was allowed to stand in a constant temperature and humidity apparatus (PL-3J, manufactured by Aispeck Co., ltd.) adjusted to 25℃and 90RH% for 1 hour. The amount of adsorbed moisture was calculated from the weight change before and after standing.

< X-ray diffraction measurement >

The dispersion was dried at 400℃to obtain a powder of barium titanate particles. The powder was subjected to X-ray diffraction measurement using RINT-Ultima manufactured by Physics. In the examples and comparative examples described later, the X-ray diffraction measurement was performed in the same manner. In the X-ray diffraction measurement, no X-ray diffraction peak other than the perovskite structure was observed except for comparative example 1.

< Measurement of viscosity >

A binder solution was prepared by dispersing 3g of ethylcellulose powder in 74g of terpineol (manufactured by YASUHARACHEMICAL Co.). 4.5g of the binder solution was mixed with 3g of the dispersion to obtain a slurry for viscosity measurement. Dynamic viscosity measurement was performed using a rheometer RS3000 (HAAKE) in the range of dγ/dt=0.1 to 1000s ^-1, and the value at dγ/dt=40 s ^-1 was used as the viscosity.

< Evaluation of printing Property >

The slurry for viscosity measurement was applied to a glass plate and dried at 200 ℃. The aggregates and smoothness in the dried film were visually confirmed, and the printing performance was evaluated.

And (3) the following materials: no aggregates and excellent smoothness

O: almost no aggregates and excellent in smoothness

Delta: almost no agglomerates and smoothness are problematic

X: problems of aggregation or smoothness are observed in a large amount

< Preparation of electrode paste >

50G of a dispersion (the amount of barium titanate in the dispersion was 10 g), 40g of Ni nanoparticles (NFP 301SD, manufactured by JFE MINERAL Co., ltd.) having a particle diameter of 200nm, and 10g of ethylcellulose powder were mixed, and dispersed once using Telang (registered trademark) (de-bubbling Telang) AR-250, manufactured by Xinji (THINKY) Co., ltd.). Further, a slurry for an electrode was prepared by performing secondary dispersion using a three-roll mill (manufactured by well-up production: HHC type). The concentration of the electrode paste was 60 wt%. Electrode slurries were prepared in the same manner as in examples and comparative examples described below, and were measured and evaluated.

< Preparation of paste for dielectric layer >

90G of barium titanate (manufactured by Sakai chemical Co., ltd.: BT-01, average particle diameter=300 nm) and 10g of ethylcellulose powder were added to 56.5g of terpineol-based solvent, and dispersed once using a foam-taking Toherd. Further, the slurry for the dielectric layer was prepared by performing secondary dispersion using a three-roll mill.

Preparation of laminated ceramic capacitor (MLCC)

The electrode paste was screen-printed on a barium titanate ceramic sheet (thickness=4.0 μm). It was dried at 600℃for 1 hour. A paste for a dielectric layer was screen-printed thereon. It was dried at 600℃for 1 hour. These steps were repeated to laminate a total of 20 layers. The laminate was subjected to a reduction treatment at 1200 ℃ for 2 hours under a nitrogen atmosphere containing 3% H ₂. Thereafter, heating was performed at 1000℃for 3 hours under a nitrogen atmosphere.

< Number of cracks >

The MLCC was cut vertically to 100 μm square and a cross-sectional photograph was taken at 10 ten thousand times using a Scanning Electron Microscope (SEM). In a 100 μm square MLCC, cracks present in each layer were confirmed on a cross-sectional photograph and counted.

< Evaluation of aggregation >

The electrode paste was dropped onto a glass plate, and the presence or absence of aggregates was visually determined.

In the following examples and comparative examples, samples were prepared in the same manner as in example 1, and measured and evaluated.

Example 2

A dispersion was obtained in the same manner as in example 1, except that the mixed solution of example 1 was changed to a mixed solution of 71.3g of water and 214.0g of methanol.

Example 3

A dispersion was obtained in the same manner as in example 1, except that the mixed solution in example 1 was changed to a mixed solution of 2.46g of nickel acetate tetrahydrate (manufactured by Fuji photo-pure Co., ltd.) and 57.1g of water and 171.3g of methanol.

Example 4

A dispersion was obtained in the same manner as in example 1, except that the mixed solution in example 1 was changed to a mixed solution of 0.85g of magnesium acetate tetrahydrate (manufactured by Fuji photo-pure Co., ltd.) and 57.1g of water and 171.3g of methanol.

Example 5

1.79G of tin methoxide (manufactured by alfa eastern corporation) was added to dissolve the barium hydroxide octahydrate of example 1 in 2-methoxyethanol. A dispersion was prepared in the same manner as in example 1, except for this.

Example 6

When the barium hydroxide octahydrate of example 1 was dissolved in 2-methoxyethanol, 2.02g of calcium methoxide (STREM CHEMICALS Co.) was added. A dispersion was obtained in the same manner as in example 1, except that 178g of the solution was used.

Example 7

When the barium hydroxide octahydrate of example 1 was dissolved in 2-methoxyethanol, 0.67g of tantalum methoxide (STREM CHEMICALS Co.) was added. Except for this, a dispersion was obtained in the same manner as in example 1.

Example 8

A dispersion was obtained in the same manner as in example 1, except that the mixed solution in example 1 was changed to a mixed solution of 0.92g of nickel hydroxide hydrate (manufactured by Fuji photo-pure Co., ltd.) and 57.1g of water and 171.2g of methanol.

Example 9

When the barium hydroxide octahydrate of example 1 was dissolved in 2-methoxyethanol, 0.67g of dysprosium isopropoxide (manufactured by Fuji photo-chemical Co., ltd.) was added. Except for this, a dispersion was obtained in the same manner as in example 1.

Example 10

To the mixed solution B obtained in example 1, 57.1g of water and 171.3g of methanol were added, while maintaining the temperature at 25℃with stirring, for 1 minute to obtain a solution for hydrolysis. Thus, a hydrate gel was obtained. The hydrate gel was heated to 80℃and aged for 96 hours. Ethanol was mixed with the cured product, and ultrafiltration was performed, whereby a dispersion liquid containing 40 mass% of barium titanate was obtained.

Example 11

A mixed solution B was prepared in the same manner as in example 1, except that the weight of the mixed solution A was changed to 178 g. A dispersion was obtained in the same manner as in example 1 except that 70g of butyl carbitol (manufactured by Kanto chemical Co., ltd.) was mixed with the aged substance, and the solvent was replaced with a rotary evaporator instead of ultrafiltration. The conditions for solvent displacement were: the reaction was carried out at a temperature of 70℃and a reduced pressure of 0.015MPa for 1 hour.

Example 12

A dispersion was obtained in the same manner as in example 11, except that the weight of the mixed solution a was changed to 170 g.

Example 13

A dispersion was obtained in the same manner as in example 12, except that the solution for hydrolysis was changed to a solution of 2.46g of nickel acetate tetrahydrate (manufactured by Fuji photo-pure Co., ltd.) and 57.1g of water and 171.3g of methanol.

Example 14

A dispersion was obtained in the same manner as in example 12 except that the weight of the mixed solution a was changed to 168g, and 70g of terpineol and 3.5g of linoleic acid (manufactured by fuji film and light purity chemical company) were mixed with the cured product instead of butyl carbitol.

Example 15

To the cured product obtained in example 11, 3.5g of linoleic acid was added, and the mixture was stirred at 50℃for 15 hours. 70g of butyl carbitol was added thereto, and distillation was performed by a rotary evaporator to obtain a dispersion. The conditions for distillation were set as: the temperature is 70 ℃, the decompression degree is 0.015MPa, and the time is 1 hour.

Example 16

To the cured product obtained in example 10, 70g of terpineol was added. Distillation was carried out using a rotary evaporator at a temperature of 70℃and a reduced pressure of 0.015MPa for 1 hour.

Example 17

To the cured product obtained in example 10, 70g of triethanolamine was added. Distillation was carried out using a rotary evaporator at a temperature of 70℃and a reduced pressure of 0.015MPa for 1 hour.

Comparative example 1

A dispersion was obtained in the same manner as in example 1, except that the weight of the barium hydroxide solution was changed to 204 g.

Comparative example 2

Barium carbonate (Fuji photo-pure chemical Co., ltd.) and titanium oxide powder (Shimadzu corporation) were measured so that the molar ratio of Ba/Ti became 1.01, and mixed by using a ball mill. The mixed powder was fired at 900 ℃ in the atmosphere, and the fired powder was pulverized using a mortar.

TABLE 1

Claims

1. A dispersion of barium titanate particles, characterized in that,

The dispersion liquid contains barium titanate particles with perovskite structure and an organic solvent with a boiling point of 200-300 ℃, wherein the organic solvent has OH groups,

The atomic ratio Ba/Ti of barium and titanium of the barium titanate particles is 0.9-1.1,

The crystallite diameter of the barium titanate particles is 5-25 nm,

The water content of the dispersion is less than 3 wt.%;

And a solid component obtained by drying the dispersion at 200 ℃ for 3 hours is exposed to a condition of 25 ℃ and 90RH% for 1 hour, wherein the amount of water adsorbed by the solid component is 5 parts by mass or more relative to 100 parts by mass of the solid component.

2. The dispersion according to claim 1, wherein the polymer particles are present in the dispersion,

The perovskite structure has an axial ratio c/a of 1.005 or less.

3. The dispersion according to claim 1, wherein the polymer particles are present in the dispersion,

The organic solvent has a cyclic structure or a chain structure in which 2 or more carbon atoms are continuously carbon-carbon bonded from the end.

4. A dispersion as claimed in claim 1 or 3, wherein,

The organic solvent has an ether bond.