JP2018172242A - Sol comprising titanic acid alkali earth metal particles, production method thereof and paste comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sol of alkaline earth metal particles of titanate having good dispersibility. By using such a sol, MLCC having a smooth electrode layer and excellent electrical characteristics is realized. SOLUTION: The sol of the present invention contains alkali titanate earth metal particles having a perovskite structure. The average secondary particle diameter by the dynamic light scattering method is 4 to 80 nm, and the atomic ratio of alkaline earth metal to titanium (alkaline earth metal / Ti) is 0.95 to 1.05. The dried product obtained by drying the sol at 300 ° C. has an average primary particle diameter of 4 to 25 nm measured by an X-ray diffraction method, and the dried product contains 0.5 to 5% by weight of carbon components derived from alkoxide. include. Alkaline titanate earth metal particles having such characteristics have high dispersibility. [Selection diagram] Fig. 1

Description

  The present invention relates to an alkaline earth metal titanate particle having a perovskite structure.

  Alkaline earth metal titanate particles having a small average particle size and a uniform particle size distribution are suitable for dielectric materials for electronic parts, optical materials with high refractive index and excellent transparency. In particular, crystalline alkaline earth metal titanates such as barium titanate are known as high dielectric materials and are used in electronic components such as ceramic capacitors.

  In recent years, multilayer ceramic capacitors (MLCC) have been required to be downsized, highly integrated (multilayered), and large in capacity. Therefore, it is necessary to make the internal electrode thin. Therefore, the internal electrode is required to have low resistance, no cracks, and excellent adhesion between multilayers.

  The electrode layer of MLCC contains nickel particles as conductive particles and 50-100 nm barium titanate particles as a co-material for the purpose of raising the sintering temperature. Therefore, the sintering temperature of the electrode layer can be set to a temperature close to 1000 to 1200 ° C. that is the sintering temperature of the dielectric layer. As a result, the stress concentration of the film is alleviated and the generation of cracks can be reduced. Since the electrode layer has been increasingly thinned in recent years, a barium titanate dispersion having a small particle size of 30 nm or less and high dispersibility is required.

  Patent Document 1 discloses a method for producing barium titanate having a small average particle diameter. Specifically, barium titanate is prepared using an alkyl cellosolve solution of barium hydroxide and titanium alkoxide. It is described that a dense film can be realized by such barium titanate.

  Patent Document 2 discloses that the surface of barium titanate particles is coated with organic silica. It is described that a film made of such a coating solution containing barium titanate particles achieves a high refractive index and transmittance and is excellent in adhesion to a substrate.

JP 2012-240904 A Japanese Patent Laid-Open No. 08-012029

  However, the particles obtained by the method described in Patent Document 1 have low surface hydrophobicity, and the surface potential is charged on the positive side. Therefore, the subject that the solvent and matrix component which are added as a coating material was restricted occurred. That is, aggregation is likely to occur depending on the solvent and the matrix component, and the pot life of the paint is shortened. A film formed of such a paint has drawbacks such as poor smoothness or high haze.

  Further, the barium titanate particles described in Patent Document 2 are surface-treated with organosilane. Therefore, a relatively stable paint can be obtained. However, it is difficult to completely remove silane even after baking at a high temperature of 1000 ° C. or higher. When the barium titanate particles are used for the internal electrode of the MLCC, the remaining silane may cause a decrease in conductivity and a decrease in the dielectric constant of the dielectric layer. Therefore, there is a problem that a high-performance MLCC cannot be obtained.

  An object of the present invention is to obtain a sol containing alkaline earth metal titanate particles having good dispersibility. By using a sol containing such alkaline earth metal titanate particles, a highly dispersed MLCC electrode layer paste containing nickel particles, a binder and a solvent is obtained. As a result, an MLCC having a smooth electrode layer, few cracks, and excellent electrical characteristics can be obtained.

  The sol containing alkaline earth metal titanate particles according to the present invention has an average secondary particle diameter of 4 to 80 nm by a dynamic light scattering method, and an atomic ratio of alkaline earth metal to titanium (alkaline earth metal / Ti). 0.95 to 1.05, and an average primary particle size measured by X-ray diffraction of a dried product obtained by drying the sol at 300 ° C. is 4 to 25 nm, and this dried product is derived from an alkoxide. Is contained in an amount of 0.5 to 5% by weight. Such alkaline earth metal titanate particles have good dispersibility in metal fine particles, binder components, solvents, and the like. A dense electrode can be formed using a paste containing such alkaline earth metal titanate particles.

  Further, an organic compound is coordinated to the alkaline earth metal titanate particles. Thereby, it is possible to form a dense internal electrode with better dispersibility. As the organic compound, it is suitable to coordinate at least one of carboxylic acid and β-diketone.

  The alkaline earth metal titanate particles contain 0.1 to 10 mol% of at least one element selected from 2A group, 8 group, lanthanoid series, and actinoid series.

It is a schematic diagram which shows a lateral type circuit.

  The sol of the present invention contains alkali earth titanate particles having a perovskite structure. The average secondary particle diameter by dynamic light scattering method is 4 to 80 nm, and the atomic ratio of alkaline earth metal to titanium (alkaline earth metal / Ti) is 0.95 to 1.05. The dried product obtained by drying the sol at 300 ° C. has an average primary particle diameter measured by X-ray diffraction method of 4 to 25 nm, and the dried product contains an alkoxide-derived carbon component of 0.5 to 5% by weight. include. Alkaline earth titanate metal particles having such characteristics are highly dispersible in metal fine particles, binder components, solvents and the like. Therefore, the dispersion liquid containing such particles has high dispersibility and can be applied to various uses.

  If the average secondary particle size is less than 4 nm, the crystallinity is low and it is difficult to obtain particles. When it exceeds 80 nm, the dispersibility with respect to a metal microparticle, a binder component, a solvent, etc. will become low and a smooth film | membrane may not be obtained.

  When the atomic ratio of alkaline earth metal to titanium (alkaline earth metal / Ti) is in the range of 0.95 to 1.05, there is almost no elution of Ti component or Ba component into the dispersion. Therefore, alkaline earth metal titanate particles having high crystallinity and high dispersibility can be obtained. Furthermore, since this dispersion liquid has few these eluting components, it can obtain MLCC with good electrical characteristics.

  The average primary particle size is preferably in the range of 4 to 25 nm. Those having an average primary particle diameter of less than 4 nm have low crystallinity and are difficult to obtain as particles. If the particle size exceeds 25 nm, it is possible to obtain highly dispersible particles. However, when an MLCC electrode layer is prepared, the number of alkaline earth metal titanate particles in the electrode layer is small. The effect may not be obtained and cracks may occur.

Furthermore, a configuration in which at least one organic compound such as carboxylic acid and β-diketone is coordinated with alkaline earth metal titanate particles containing a carbon component derived from alkoxide is preferable. With such a configuration, dispersibility is further improved. When carboxylic acid is coordinated to this particle, it is considered that a peak appears in the range of 165 to 167 ppm when C ¹³ -NMR is measured.

  Even if an organic compound such as carboxylic acid or β-diketone is coordinated to an alkaline earth metal titanate particle that does not contain an alkoxide-derived carbon component, the dispersibility in metal fine particles, binder component, solvent, etc. may be low. is there. Further, even if an electrode layer paste is prepared to produce MLCC, the film has poor smoothness and is not uniform, and cracks may occur during firing.

  Furthermore, the alkaline earth metal titanate particles preferably contain 0.1 to 10 mol% of at least one element selected from 2A group, 8 group, lanthanoid type, and actinoid type. A form in which some of the alkaline earth metal particles are substituted with these elements can be exemplified. According to such a configuration, the temperature at which the electrode layer is sintered becomes high and becomes close to the sintering temperature of the dielectric layer, so that cracks can be reduced during MLCC fabrication.

  In addition, according to the present invention, “a method for producing a sol containing alkaline earth metal titanate particles” is a method of preparing a dispersion containing alkaline earth metal titanate particles using an alkaline earth metal hydroxide and a titanium alkoxide. And a coordination step of coordinating an organic substance having a carbonyl group or a carboxyl group to the alkaline earth metal titanate particles.

  At this time, the step of preparing the dispersion is performed by hydrolysis in the first step of mixing the alkaline earth metal hydroxide and the titanium alkoxide, and in the presence of water that is equal to or greater than the number of moles of the titanium alkoxide. A second step for obtaining a hydrolyzate, and a third step for replacing the solvent contained in the hydrolyzate with an organic solvent containing at least one of ethers, ketones, esters and alcohols. Contains.

  Further, in the first step, the alkaline earth metal hydroxide and titanium alkoxide are mixed so that the atomic ratio of the alkaline earth metal to titanium (alkaline earth metal / Ti) is 0.95 to 1.05. It is preferable to do. Within this range, there is almost no elution of the Ti component or Ba component into the dispersion, so that a dispersion of alkaline earth metal titanate particles having high crystallinity and high dispersibility can be obtained. Furthermore, since the obtained dispersion has few these elution components, MLCC with high electrical characteristics can be realized.

  In addition, the alkaline earth metal hydroxide used in the first step is dissolved in an alkyl cellosolve, and the alkaline earth metal obtained by the step of preparing the water content in the liquid to 0.5% by weight or less is obtained. An alkyl cellosolve solution of hydroxide is preferred. If the water content exceeds 0.5% by weight, the alkyl cellosolve solution may be oxidized, and the alkaline earth metal titanate particles may not be obtained in the second step.

Further, in the second step, the mixture obtained in the first step, the number of moles of Ti _{(M T)} and the number of moles of water _{(M H2 O)} molar ratio of _(M H2O / _{M T)} is 4 or more 64 Water is added under agitation so that: The addition is carried out over 1 minute to 1 hour while controlling the liquid temperature to -40 to 50 ° C. Thereafter, the liquid temperature is raised to 60 ° C. to 250 ° C. and left for 1 to 200 hours for aging. Thereby, a dispersion of alkaline earth metal titanate particles is obtained.

  Further, methyl cellosolve is suitable as the organic solvent used in the third step.

An electrode can be formed by preparing a paste using such a sol. The paste containing alkaline earth metal particles of the present invention is suitable for an internal electrode of MLCC.
[Example]
Below, the Example which used barium as an alkaline-earth metal is described concretely based on a manufacturing method. The present invention is not limited to these examples.
[Example 1]
(Process A)
50 g of barium hydroxide octahydrate (Wako Pure Chemical Industries, Ltd.) and 315 g of 2-methoxyethanol (methyl cellosolve) were placed in a beaker and dissolved at 30 ° C. for 20 minutes, and the solution (A-1) was dissolved. Prepared. The Ba concentration of this solution was 6.0% by weight, and the water content was 6.2% by weight. This solution was put into a 1 liter eggplant-shaped flask, and a water removal operation was performed using a rotary evaporator at a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour to obtain a solution (A-2). The Ba concentration of this solution was 16.0% by weight, and the water content was 0.5% by weight.

(Process B)
Next, in 170 g of the solution (A-2), tetraisopropoxy titanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: Orgatics TA-10; Ti concentration 16.88% so that the Ba / Ti atomic ratio is 1.00. ) 56.18 g was mixed in a glove box under a nitrogen gas atmosphere to prepare a solution (B-1). To this solution, as the number of moles of Ti _{(M T)} and the number of moles of water _{(M H2 O)} molar ratio of _(M H2O / _{M T)} is 16, the mixing of water 57.1g and methanol 171.3g The liquid was added under stirring. At this time, it added over 2 hours. The liquid temperature was maintained at 25 ° C. Thereby, tetraisopropoxy titanium was hydrolyzed and the hydrate gel was obtained.

(Process C)
The hydrate gel was heated to 80 ° C. and aged for 96 hours. Thereby, a dispersion (C) of crystalline barium titanate was obtained.

(Process D)
Dispersion of the barium titanate dispersion (C) was replaced with methyl cellosolve to prepare a crystalline barium titanate methyl cellosolve dispersion (D1) (solid content 20 wt%).

Using the barium titanate dispersion (C) or dispersion (D1) obtained as described above, samples were prepared and evaluated as shown below. The results are shown in Table 1.
(1) Barium titanate particles The dispersion (C) of barium titanate was dried at 300 ° C. for 2 hours to be powdered, and the crystal form and crystallite diameter (D _CT ) were measured by X-ray diffraction. The crystallite size was defined as the average primary particle size. The crystal form was a perovskite type, and the crystallite diameter was 10 nm. Furthermore, the carbon content of the powder was measured using a carbon sulfur analyzer (EMIA-320V manufactured by HORIBA). This was defined as the amount of carbon derived from the alkoxide.

On the other hand, the secondary particle size was determined from the dispersion (D1) of barium titanate. That is, it measured using the dynamic light-scattering particle size distribution measuring apparatus (PAR-III by Otsuka Electronics Co., Ltd.), and made the cumulant particle diameter the secondary particle diameter.
(2) Electrode paste 50 g of barium titanate dispersion (D1), 40 g of Ni nanoparticles with a particle size of 200 nm (NFP301SD made by JFE Mineral), and 10 g of ethylcellulose powder were mixed together, and Nendotaro Awatori (Sinky Corporation: AR) -250). Furthermore, the paste (E1) for electrodes was prepared by carrying out the secondary dispersion using the triple roll (made by Inoue Manufacturing Co., Ltd .: HHC type). The composition at this time is shown in Table 1.

Furthermore, the dispersibility of this paste was evaluated. The paste was dropped into a glass plate, and the presence or absence of aggregates was visually determined according to the following criteria.
A: Almost no agglomerates are observed. O: Agglomerates are slightly present.
Δ: Some agglomerates are present.
X: Many aggregates exist.
XX: State in which particles and solvent are separated.
(3) Multilayer ceramic capacitor (MLCC)
The internal electrode of the multilayer ceramic capacitor was formed using the above-mentioned electrode paste. Details are shown below.

  First, a dielectric layer paste was prepared. That is, 90 g of barium titanate (manufactured by Sakai Chemical Co., Ltd .: BT-01, average particle size = 300 nm) and 10 g of ethylcellulose-based powder were added to 56.5 g of terpineol-based solvent. -250). Subsequently, a dielectric layer paste was prepared by secondary dispersion using a triple roll (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

The aforementioned electrode paste was screen printed on a barium titanate ceramic sheet (thickness = 4.0 μm) to form a pattern. Subsequently, it dried at 600 degreeC for 1 hour. Further, a dielectric layer paste was screen printed from above to form a pattern. Subsequently, it dried at 600 degreeC for 1 hour. This was repeated and 20 layers were laminated. Subsequently, reduction treatment was performed at 1200 ° C. for 2 hours in a nitrogen gas atmosphere containing 3% of H ₂ . Subsequently, it heat-processed at 1000 degreeC under nitrogen gas atmosphere for 3 hours. In this way, a multilayer ceramic capacitor was produced.

  The following evaluation was performed about the obtained multilayer ceramic capacitor. The results are shown in Table 1.

<Smoothness>
The smoothness was evaluated by a film formed by applying a single layer of electrode paste. That is, an electrode paste was applied to form an internal electrode layer and dried at 600 ° C. for 1 hour. Table 1 shows the thickness of the single layer of the internal electrode layer. The film surface was measured with an atomic force microscope (AFM), and a surface roughness Ra in the range of 20 μm was obtained.

<crack>
The multilayer ceramic capacitor was cut vertically, and a cross-sectional photograph was taken at a magnification of 100,000 using a scanning electron microscope (SEM). Whether or not there is a crack in each layer present at 100 μm square was confirmed by a cross-sectional photograph, and the number of cracks was counted.

<MLCC characteristics>
The capacitance was measured using a lateral type circuit. FIG. 1 shows a lateral circuit. A pair of connection electrodes 2 is provided on the extraction electrode of the capacitor 1. A voltage is applied from the power supply through the connection electrode. Based on the number of times of charging / discharging when a DC voltage of 200 V was applied, the determination was made as follows.
◎: Charging / discharging 1000 times or more possible ○: Charging / discharging 101-less than 1000 times △: Charging / discharging 51-100 times possible ×: Charging / discharging less than 50 times
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 1 g of acetylacetone was added and stirred at 50 ° C. for 15 hours. This was concentrated using a rotary evaporator to obtain a crystalline barium titanate dispersion (D2) (solid concentration 20 wt%).

Evaluation was carried out in the same manner as in Example 1, except that the barium titanate methyl cellosolve dispersion (D2) was used instead of the barium titanate methyl cellosolve dispersion (D1). The results are shown in Table 1.
[Example 3]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 2 g of acetylacetone was added and stirred at 50 ° C. for 15 hours. This was concentrated using a rotary evaporator to obtain a crystalline barium titanate dispersion (D3) (solid content concentration 20% by weight).

Evaluation was conducted in the same manner as in Example 1 except that the barium titanate dispersion (D3) was used instead of the barium titanate dispersion (D1) in Example 1. The results are shown in Table 1.
[Example 4]
4 g of acetylacetone was added to 100 g of the barium titanate dispersion (D1) obtained in Example 1, and the mixture was stirred at 50 ° C. for 15 hours. This was concentrated using a rotary evaporator to obtain a crystalline barium titanate dispersion (D4) (solid content concentration 20% by weight).

Evaluation was performed in the same manner as in Example 1 except that the barium titanate dispersion (D4) was used instead of the barium titanate dispersion (D1) in Example 1. The results are shown in Table 1.
[Example 5]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 1.21 g of acetic acid (concentration 33.0%) was added and stirred at 50 ° C. for 15 hours. This was subjected to solvent replacement with 500 g of ethanol using an ultra membrane, to obtain a crystalline ethanol dispersion of barium titanate (D5) (solid content concentration 20% by weight).

Evaluation was carried out in the same manner as in Example 1, except that an ethanol dispersion (D5) of barium titanate was used instead of the dispersion (D1) of barium titanate in Example 1. The results are shown in Table 1.
[Example 6]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 2.02 g of oleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this, 50 g of terpineol was added and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion (D6) of barium titanate (solid content concentration: 40% by weight).
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D6), 25 g of terpineol, 40 g of Ni nanoparticles with a particle size of 200 nm (NFP301SD made by JFE Mineral), and 10 g of ethylcellulose powder were mixed together, and Narotaro Awatori (Sinky Corporation: AR-250) Was used for primary dispersion. Furthermore, the paste for electrodes (E6) was prepared by carrying out secondary dispersion using three rolls (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

Evaluation was performed in the same manner as in Example 1 by using the barium titanate dispersion (D6) or electrode paste (E6) of this example. The results are shown in Table 1.
[Example 7]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 1.01 g of linoleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this, 50 g of terpineol was added and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion (D7) of barium titanate (solid content concentration 40 wt%).

Evaluation was carried out in the same manner as in Example 6, except that the barium titanate dispersion (D7) according to this example was used instead of the barium titanate dispersion (D6) of Example 6. The results are shown in Table 1.
[Example 8]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 2.02 g of linoleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of terpineol and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion (D8) of barium titanate (solid content concentration 40 wt%).

Evaluation was carried out in the same manner as in Example 6, except that the barium titanate dispersion (D8) of this example was used instead of the barium titanate dispersion (D6) of Example 6. The results are shown in Table 1.
[Example 9]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 4.04 g of linoleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of terpineol and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion of barium titanate (D9) (solid content concentration 40 wt%).

Evaluation was carried out in the same manner as in Example 6, except that the barium titanate dispersion (D9) of this example was used instead of the barium titanate dispersion (D6) of Example 6. The results are shown in Table 1.
[Example 10]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 2.02 g of sorbitan palmitate (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of dihydroterpineol acetate, and the mixture was concentrated by a rotary evaporator to obtain a crystalline dihydroterpinel acetate dispersion (D10) (solid content concentration: 40% by weight) of barium titanate.
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D10) according to this example, 25 g of dihydroterpineol acetate, 40 g of Ni nanoparticles having a particle size of 200 nm (NFP301SD made by JFE Mineral), and 10 g of ethylcellulose powder were mixed together. Primary dispersion was carried out using a Shinkey Co., Ltd. AR-250). Furthermore, the paste for electrodes (E10) was prepared by carrying out secondary dispersion using a triple roll (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

Evaluation was performed in the same manner as in Example 1 by using the barium titanate dispersion (D10) or electrode paste (E10) of this example. The results are shown in Table 1.
[Example 11]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 2.02 g of sorbitan oleate (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of dihydroterpineol acetate, and the mixture was concentrated by a rotary evaporator to obtain a crystalline dihydroterpinel acetate dispersion (D11) of barium titanate (solid content concentration 40% by weight).

Evaluation was performed in the same manner as in Example 10 except that the barium titanate dispersion (D11) according to this example was used instead of the barium titanate dispersion (D10) in Example 10. The results are shown in Table 1.
[Example 12]
To 100 g of the barium titanate dispersion (D1) obtained in Example 1, 2.02 g of glyceryl stearate (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of dihydroterpineol acetate, and the mixture was concentrated with a rotary evaporator to obtain a crystalline dihydroterpinel acetate dispersion (D12) (solid content concentration 40% by weight) of barium titanate.

Evaluation was conducted in the same manner as in Example 10 except that the barium titanate dispersion (D12) according to this example was used instead of the barium titanate dispersion (D10) in Example 10. The results are shown in Table 1.
[Example 13]
To 170 g of the solution (A-2) obtained in Step A of Example 1, tetraisopropoxytitanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: ORGATICS TA-10; Ti) so that the Ba / Ti atomic ratio is 0.998 56.07 g) (concentration 16.88%) was mixed in a glove box under a nitrogen gas atmosphere. Thereafter, 0.011 g of lanthanum hydroxide (Mw 189.93 manufactured by Junsei Kagaku) was added and mixed so that the atomic ratio Ba / (Ti + La) was 1. To this solution, as the number of moles of Ti _{(M T)} and the number of moles of water _{(M H2 O)} molar ratio of _(M H2O / _{M T)} is 16, water 57.1 g, mixture of methanol 171.3g The liquid was added under stirring. At this time, it added over 2 hours. The liquid temperature was maintained at 25 ° C. Thereby, tetraisopropoxy titanium was hydrolyzed and the hydrate gel was obtained.

(Process C)
The hydrate gel was heated to 80 ° C. and aged for 96 hours. As a result, a dispersion (C13) of crystalline barium titanate was obtained.

(Process D)
The dispersion of barium titanate (C13) was solvent-substituted with methyl cellosolve to prepare a crystalline cellosolve dispersion of barium titanate (solid content concentration 20% by weight). To 100 g of this methyl cellosolve dispersion, 2.02 g of oleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of terpineol and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion of barium titanate (D13) (solid content concentration 40 wt%).

Using the barium titanate dispersion (C13) or dispersion (D13) obtained as described above, samples were prepared and evaluated as shown below. The results are shown in Table 1.
(1) Barium titanate particles Evaluation was performed in the same manner as in Example 1 using a barium titanate dispersion (C13). In addition, about the composition of La, it quantified by the fluorescent X ray analysis by the briquette method using the obtained powder, and confirmed that La / (Ba + Ti + La) was 2 mmol.
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D13), 25 g of dihydroterpineol acetate, 40 g of Ni nanoparticles having a particle diameter of 200 nm (NFP301SD made by JFE Mineral) and 10 g of ethylcellulose powder were mixed together, and Narotaro Awatori (Sinky Corporation's product: AR-250) was used for primary dispersion. Furthermore, the paste for electrodes (E13) was prepared by carrying out secondary dispersion using three rolls (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

Evaluation was performed in the same manner as in Example 1 by using the barium titanate dispersion (D13) or electrode paste (E13) of this example. The results are shown in Table 1.
[Example 14]
To 170 g of the solution (A-2) obtained in Step A of Example 1, tetraisopropoxy titanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: ORGATIX TA-10; Ti) so that the Ba / Ti atomic ratio is 0.992. 55.73 g (concentration 16.88%) was mixed in a glove box under a nitrogen gas atmosphere. Thereafter, 55.73 g of tetraisopropoxy titanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: Organics TA-10 Ti concentration 16.88%) was mixed so that the atomic ratio Ba / (Ti + Ca) was 0.992. Then, 0.122 g of calcium hydroxide (Kanto Chemical Co., Ltd. Mw74) was added and mixed so that the atomic ratio Ba / (Ti + Ca) was 1. To this solution, as the number of moles of Ti _{(M T)} and the number of moles of water _{(M H2 O)} molar ratio of _(M H2O / _{M T)} is 16, water 57.1 g, mixture of methanol 171.3g The liquid was added under stirring. At this time, it added over 2 hours. The liquid temperature was maintained at 25 ° C. Thereby, tetraisopropoxy titanium was hydrolyzed and the hydrate gel was obtained.

(Process C)
The hydrate gel was heated to 80 ° C. and aged for 96 hours. As a result, a dispersion (C14) of crystalline barium titanate was obtained.

(Process D)
The dispersion of barium titanate (C14) was solvent-substituted with methyl cellosolve to prepare a crystalline cellosolve dispersion of barium titanate (solid content concentration 20% by weight). To 100 g of this methyl cellosolve dispersion, 2.02 g of oleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of terpineol and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion (D14) of barium titanate (solid content concentration 40 wt%).

Using the barium titanate dispersion (C14) or dispersion (D14) obtained as described above, samples were prepared and evaluated as shown below. The results are shown in Table 1.
(1) Barium titanate particle It evaluated similarly to Example 1 using the dispersion liquid (C14) of a barium titanate. In addition, about the composition of Ca, it quantified by the fluorescent X ray analysis by the briquette method using the obtained powder, and it confirmed that Ca / (Ba + Ti + Ca) was 8 mmol.
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D14), 25 g of dihydroterpineol acetate, 40 g of Ni nanoparticles having a particle size of 200 nm (NFP301SD made by JFE Mineral) and 10 g of ethylcellulose powder were mixed together, and Narotaro Awatori (Sinky Corp .: AR-250) was used for primary dispersion. Furthermore, the paste for electrodes (E14) was prepared by carrying out secondary dispersion using a three-roll (made by Inoue Manufacturing Co., Ltd .: HHC type).

Evaluation was carried out in the same manner as in Example 1 using the barium titanate dispersion (D14) or electrode paste (E14) of this example. The results are shown in Table 1.
[Example 15]
To 170 g of the solution (A-2) obtained in Step A of Example 1, tetraisopropoxytitanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: ORGATICS TA-10; Ti) so that the Ba / Ti atomic ratio is 0.995 55.90 g) (concentration 16.88%) was mixed in a glove box under a nitrogen gas atmosphere. Thereafter, 0.127 g of strontium hydroxide (anhydrous) (Mitsuwa Chemical Co., Ltd., Mw 121.63) was added and mixed so that the atomic ratio Ba / (Ti + Sr) was 1. To this solution, as the number of moles of Ti _{(M T)} and the number of moles of water _{(M H2 O)} molar ratio of _(M H2O / _{M T)} is 16, water 57.1 g, mixture of methanol 171.3g The liquid was added under stirring. At this time, it added over 2 hours. The liquid temperature was maintained at 25 ° C. Thereby, tetraisopropoxy titanium was hydrolyzed and the hydrate gel was obtained.

(Process C)
The hydrate gel was heated to 80 ° C. and aged for 96 hours. Thereby, a dispersion (C15) of crystalline barium titanate was obtained.

(Process D)
The dispersion of the barium titanate dispersion (C15) was solvent-substituted with methyl cellosolve to prepare a crystalline cellosolve dispersion of barium titanate (solid content concentration 20% by weight). To 100 g of this methyl cellosolve dispersion, 2.02 g of oleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this was added 50 g of terpineol and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion of barium titanate (D15) (solid content concentration 40 wt%).

Using the barium titanate dispersion (C15) or dispersion (D15) obtained as described above, samples were prepared and evaluated as shown below. The results are shown in Table 1.
(1) Barium titanate particles Evaluation was performed in the same manner as in Example 1 using a dispersion (C15) of barium titanate. In addition, about the composition of Sr, it quantified by the fluorescent X ray analysis by the briquette method using the obtained powder, and confirmed that Sr / (Ba + Ti + Sr) was 5 mmol.
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D15), 25 g of dihydroterpineol acetate, 40 g of Ni nanoparticles having a particle diameter of 200 nm (NFP301SD made by JFE Mineral), and 10 g of ethylcellulose powder were mixed together, and Narotaro Awatori (manufactured by Shinky Corporation: AR-250) was used for primary dispersion. Furthermore, the paste for electrodes (E15) was prepared by carrying out secondary dispersion using three rolls (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

Evaluation was performed in the same manner as in Example 1 by using the barium titanate dispersion (D15) or electrode paste (E15) of this example. The results are shown in Table 1.
[Example 16]
Tetraisopropoxytitanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: Orgatics TA-10) was added to 175.10 g of the solution (A-2) obtained in Step A of Example 1 so that the Ba / Ti atomic ratio was 1.03. A Ti concentration of 16.88%) was mixed in a glove box under a nitrogen gas atmosphere. Thereafter, 55.73 g of tetraisopropoxy titanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: Organics TA-10 Ti concentration 16.88%) was mixed so that the atomic ratio Ba / (Ti + Ca) was 0.992. To this solution, as the number of moles of Ti _{(M T)} and the number of moles of water _{(M H2 O)} molar ratio of _(M H2O / _{M T)} is 20, water 71.4 g, mixture of methanol 214.2g The liquid was added under stirring. At this time, it added over 2 hours. The liquid temperature was maintained at 25 ° C. Thereby, tetraisopropoxy titanium was hydrolyzed and the hydrate gel was obtained.

(Process C)
The hydrate gel was heated to 80 ° C. and aged for 96 hours. Thereby, a dispersion (C16) of crystalline barium titanate was obtained.

(Process D)
The dispersion of barium titanate (C16) was solvent-substituted with methyl cellosolve to prepare a crystalline cellosolve dispersion of barium titanate (solid content concentration 20% by weight). To 100 g of this methyl cellosolve dispersion, 2.02 g of oleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this, 50 g of terpineol was added and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion of barium titanate (D16) (solid content concentration 40 wt%).
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D16) according to this example, 25 g of dihydroterpineol acetate, 40 g of Ni nanoparticles having a particle size of 200 nm (NFP301SD manufactured by JFE Mineral), and 10 g of ethylcellulose powder were mixed together. Primary dispersion was carried out using a Shinkey Co., Ltd. AR-250). Furthermore, the paste for electrodes (E16) was prepared by carrying out secondary dispersion using a triple roll (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

Evaluation was made in the same manner as in Example 1 using the dispersion (C16), dispersion (D16), or electrode paste (E16) of barium titanate of this example. The results are shown in Table 1.
[Example 17]
Tetraisopropoxytitanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: Orgatics TA-10) was added to 175.10 g of the solution (A-2) obtained in Step A of Example 1 so that the Ba / Ti atomic ratio was 1.03. A Ti concentration of 16.88%) was mixed in a glove box under a nitrogen gas atmosphere. To this solution, as the number of moles of Ti _{(M T)} and the number of moles of water _{(M H2 O)} molar ratio of _(M H2O / _{M T)} is 10, water 35.7 g, mixture of methanol 107.1g The liquid was added under stirring. At this time, it added over 2 hours. The liquid temperature was maintained at 25 ° C. Thereby, tetraisopropoxy titanium was hydrolyzed and the hydrate gel was obtained.

(Process C)
The hydrate gel was heated to 80 ° C. and aged for 96 hours. As a result, a dispersion of crystalline barium titanate (C17) was obtained.

(Process D)
The dispersion of the barium titanate dispersion (C17) was solvent-substituted with methyl cellosolve to prepare a crystalline cellosolve dispersion of barium titanate (solid content concentration 20% by weight). To 100 g of this methyl cellosolve dispersion, 2.02 g of oleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this, 50 g of terpineol was added and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion (D17) of barium titanate (solid content concentration 40% by weight).
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D17), 25 g of dihydroterpineol acetate, 40 g of Ni nanoparticles having a particle size of 200 nm (NFP301SD manufactured by JFE Mineral) and 10 g of ethyl cellulose powder were mixed together according to this example. Primary dispersion was carried out using a Shinkey Co., Ltd. AR-250). Furthermore, the paste for electrodes (E17) was prepared by carrying out secondary dispersion using a three-roll (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

Evaluation was performed in the same manner as in Example 1 using the dispersion (C17), dispersion (D17), or electrode paste (E17) of barium titanate of this example. The results are shown in Table 1.
[Comparative Example 1]
In order to obtain crystalline barium titanate, TFP-NA-E (Toda Kogyo Co., Ltd.) was dried at 100 ° C. for 1 hour. 20 g of this powder was stirred and mixed with 80 g of methyl cellosolve to prepare a methyl cellosolve dispersion (R-1) of barium titanate having a solid concentration of 20% by weight. The obtained dispersion (R-1) was dried at 300 ° C. for 2 hours to be powdered, and the crystal form and crystallite diameter (D _CT ) were measured by X-ray diffraction. The crystallite size was defined as the average primary particle size. The crystal form was a perovskite type, and the crystallite diameter was 10 nm. Furthermore, the carbon content of the powder was measured using a carbon sulfur analyzer (EMIA-320V manufactured by HORIBA), and this was defined as the carbon content derived from the alkoxide.

On the other hand, the secondary particle diameter was determined from a dispersion (R-1) of barium titanate. That is, it measured using the dynamic light-scattering particle size distribution measuring apparatus (PAR-III by Otsuka Electronics Co., Ltd.), and made the cumulant particle diameter the secondary particle diameter.
<< Preparation of electrode paste >>
50 g of barium titanate dispersion (R-1), 40 g of Ni nanoparticles having a particle diameter of 200 nm (NFP301SD made by JFE Mineral), and 10 g of ethylcellulose powder were mixed together, and Narutaro Awatori (Sinky Corporation: AR-250) was used. Used for primary dispersion. Furthermore, the paste for electrodes (E-R1) was prepared by performing secondary dispersion using a triple roll (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

Evaluation was carried out in the same manner as in Example 1 by using a dispersion of barium titanate (R-1) or electrode paste (E-R1). The results are shown in Table 1.
[Comparative Example 2]
To 100 g of the methyl cellosolve dispersion (R-1) obtained in Comparative Example 1, 2.02 g of oleic acid (concentration 99%) was added and stirred at 50 ° C. for 15 hours. To this, 50 g of terpineol was added and concentrated with a rotary evaporator to obtain a crystalline terpineol dispersion of barium titanate (D-R2) (solid content concentration 40 wt%).
<< Preparation of electrode paste >>
25 g of barium titanate dispersion (D-R2), 25 g of terpineol, 40 g of Ni nanoparticles having a particle size of 200 nm (NFP301SD made by JFE Mineral) and 10 g of ethylcellulose powder were mixed together, and Narotaro Awatori (Sinky Co., Ltd .: AR-) 250). Furthermore, the paste for electrodes (E-R2) was prepared by carrying out secondary dispersion using a triple roll (manufactured by Inoue Seisakusho Co., Ltd .: HHC type).

  Evaluation was performed in the same manner as in Example 1 using a dispersion of barium titanate (D-R2) or electrode paste (E-R2). The results are shown in Table 1.

Claims (9)

  A sol containing perovskite structure alkaline earth metal titanate particles having an average secondary particle diameter of 4 to 80 nm by dynamic light scattering, and an atomic ratio of alkaline earth metal to titanium (alkaline earth metal / Ti) is 0.95 to 1.05, and the dried product obtained by drying the sol at 300 ° C. has an average primary particle diameter measured by X-ray diffraction method of 4 to 25 nm. A sol containing 0.5 to 5% by weight of an alkoxide-derived carbon component.   The sol according to claim 1, wherein an organic compound is coordinated to the alkaline earth metal titanate particles.   The sol according to claim 2, wherein at least one of carboxylic acid and β-diketone is coordinated to the alkaline earth metal titanate particles.   The alkali earth titanate metal particles contain 0.1 to 10 mol% of at least one element selected from 2A group, 8 group, lanthanoid series, and actinoid series. The sol according to claim 1. Producing a dispersion containing alkaline earth metal titanate particles using an alkaline earth metal hydroxide and a titanium alkoxide;
A coordination step of coordinating an organic substance having a carbonyl group or a carboxyl group to the alkaline earth metal titanate particles;
A method for producing a sol containing alkaline earth metal titanate particles. The step of preparing the dispersion comprises
A first step of mixing an alkaline earth metal hydroxide and a titanium alkoxide;
In the presence of moisture that is equal to or greater than the number of moles of the titanium alkoxide, hydrolysis is performed to obtain a hydrolyzate,
A third step of replacing the solvent contained in the hydrolyzate with an organic solvent containing at least one of ethers, ketones, esters and alcohols;
The method for producing a sol according to claim 5, comprising:   Alkaline earth metal water obtained by the step in which the alkaline earth metal hydroxide used in the first step is dissolved with alkyl cellosolve and the water content in the liquid is adjusted to 0.5 wt% or less. The method for producing a sol according to claim 6, wherein the solution is an alkyl cellosolve solution of an oxide.   In the first step, the alkaline earth metal hydroxide and the alkali earth metal and Ti so that the atomic ratio (alkaline earth metal / Ti ratio) is in the range of 0.95 to 1.05. Titanium alkoxide is mixed, The manufacturing method of the sol of Claim 6 or 7 characterized by the above-mentioned.   A paste comprising the sol according to claim 1, metal colloid particles, a binder component, and a solvent.