WO2021066070A1 - Barium titanate particles, method for producing same, and dispersion of barium titanate particles - Google Patents

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

Info

Publication number
WO2021066070A1
WO2021066070A1 PCT/JP2020/037304 JP2020037304W WO2021066070A1 WO 2021066070 A1 WO2021066070 A1 WO 2021066070A1 JP 2020037304 W JP2020037304 W JP 2020037304W WO 2021066070 A1 WO2021066070 A1 WO 2021066070A1
Authority
WO
WIPO (PCT)
Prior art keywords
barium titanate
titanate particles
barium
organic solvent
mixed solution
Prior art date
Application number
PCT/JP2020/037304
Other languages
French (fr)
Japanese (ja)
Inventor
和馬 渡邉
光章 熊澤
良 村口
Original Assignee
日揮触媒化成株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日揮触媒化成株式会社 filed Critical 日揮触媒化成株式会社
Priority to JP2021551421A priority Critical patent/JPWO2021066070A1/ja
Priority to KR1020217037796A priority patent/KR20220074821A/en
Priority to CN202080042148.5A priority patent/CN113939476B/en
Publication of WO2021066070A1 publication Critical patent/WO2021066070A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G23/00—Compounds of titanium
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G23/00—Compounds of titanium
    • C01G23/003—Titanates
    • C01G23/006—Alkaline earth titanates
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D17/00—Pigment pastes, e.g. for mixing in paints
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D17/00—Pigment pastes, e.g. for mixing in paints
    • C09D17/004—Pigment pastes, e.g. for mixing in paints containing an inorganic pigment
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G4/00—Fixed capacitors; Processes of their manufacture
    • H01G4/002—Details
    • H01G4/005—Electrodes
    • H01G4/008—Selection of materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G4/00—Fixed capacitors; Processes of their manufacture
    • H01G4/30—Stacked capacitors
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/30—Three-dimensional structures
    • C01P2002/34—Three-dimensional structures perovskite-type (ABO3)

Definitions

  • the present invention relates to barium titanate particles having a perovskite structure.
  • Barium titanate particles are used as dielectric materials for electronic parts and optical materials with high refractive index and excellent transparency. Barium titanate particles have a high dielectric constant and are therefore used in multilayer ceramic capacitors (MLCCs).
  • the MLCC has a structure in which electrode layers and dielectric layers are alternately overlapped.
  • the electrode layer contains Ni particles having a diameter of 80 to 300 nm and barium titanate particles as a co-material.
  • barium titanate particles are packed around the Ni particles. Therefore, the temperature at which Ni particles are sintered is high. That is, the effect of delaying the sintering of Ni particles can be obtained. Therefore, the temperature at which the Ni particles are sintered and the temperature at which the dielectric layer is sintered are close to each other. As a result, the difference in shrinkage between the electrode layer and the dielectric layer becomes small during firing, and an MLCC with few cracks can be obtained (see, for example, Patent Document 1).
  • the barium titanate particles have a perovskite structure, and the c-axis axis length of the crystal lattice is made longer than the a-axis axis length, that is, barium titanate. It is known that barium particles are tetragonal. (See, for example, Patent Document 2).
  • the barium titanate particles of Patent Document 2 have a high dielectric constant because the c-axis length of the perovskite structure is longer than the a-axis length.
  • barium titanate particles are pulverized and then fired, the particle size and crystallite diameter tend to increase. Therefore, the density of the barium titanate particles packed around the Ni particles tends to be low, and it is difficult to obtain the sintering delay effect.
  • An object of the present invention is to provide barium titanate particles having a high sintering delay effect and a method for producing the same.
  • the atomic ratio Ba / Ti of barium and titanium was set to 0.9 to 1.1, and the crystallite diameter was set to 5 to 25 nm.
  • the atomic ratio Ba / Ti of barium and titanium may be 0.95 to 1.05.
  • the ratio c / a of the lengths of the c-axis and the a-axis of the crystal lattice in the perovskite structure is preferably 1.005 or less.
  • the water content is preferably less than 3% by weight.
  • the method for producing barium titanate particles is a step of mixing barium hydroxide and alkyl cellosolve, and titanium alkoxide so that the atomic ratio Ba / Ti of barium and titanium is in the range of 0.9 to 1.1. It includes a step of adding, a step of adding water, and a step of heating.
  • the barium titanate particles having a perovskite structure according to the present invention have a barium-titanium atomic ratio Ba / Ti in the range of 0.9 to 1.1. As a result, impurities such as crystals other than the perovskite structure are less likely to be generated.
  • the crystallite diameter of the barium titanate particles is 5 to 25 nm. Therefore, the crystallinity of the barium titanate particles becomes high, and the particle size becomes small. Since such barium titanate particles enter the gaps between the Ni particles in the electrode layer, the barium titanate particles are present at a high density around the Ni particles. Therefore, the sintering delay effect of Ni becomes high.
  • the crystallite diameter When the crystallite diameter is larger than 25 nm, the viscosity of the dispersion liquid of barium titanate particles described later becomes high.
  • the particle size measured by a transmission electron microscope is also 5 to 25 nm.
  • the atomic ratio Ba / Ti of barium and titanium may be 0.95 to 1.05.
  • the ratio (axial ratio) c / a of the lengths of the c-axis and the a-axis of the crystal lattice in the perovskite structure is preferably 1.005 or less. This makes the barium titanate particles closer 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 device.
  • the crystal structure can be identified using PDXL, which is analysis software.
  • D is the crystallite diameter ( ⁇ )
  • K is the Scherrer constant
  • ⁇ is the X-ray wavelength (1.7889 ⁇ )
  • ⁇ is the reflection angle.
  • the axial ratio c / a is preferably 1.003 or less. More preferably 1.001 or less. The smaller the axial ratio c / a, the higher the sintering delay effect of Ni.
  • Barium titanate particles include Group 2, Group 3, Lantanoid, Actinoid, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13, and. It is preferable that at least one element selected from Group 14 (hereinafter referred to as an additive element) is contained. As a result, the sintering delay effect is enhanced. It is more preferable that the additive element is contained in an amount of 0.1 to 10 mol% when the composition formula BaTIO 3 of barium titanate is 100 mol%. As a result, the sintering delay effect of Ni can be easily obtained. Moreover, even if the additive element is contained in this range, no peak other than the perovskite structure is observed.
  • a paste for printing the electrode layer can be prepared using a dispersion of barium titanate particles.
  • 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. When the water content is small, the viscosity of the paste is unlikely to increase even if a binder such as ethyl cellulose is added to the dispersion liquid. If the viscosity of the paste is high, it is difficult to apply the paste uniformly, so that cracks are likely to occur in the electrode layer during firing. Further, when the water content of the dispersion liquid is 3% by weight or less, the dispersion liquid is less likely to aggregate.
  • the amount of water adsorbed on the solid content of the dispersion liquid is preferably 5 parts by mass or more with respect to 100 parts by mass of the solid content.
  • the barium titanate particles in the dispersion have many hydroxyl groups on the surface.
  • the solid content is obtained by drying the dispersion at 200 ° C. for 3 hours.
  • the adsorbed water content is the amount of water adsorbed on the solid content when the solid content is exposed to the condition of 90 RH% at 25 ° C. for 1 hour.
  • the barium titanate particles are not surface-treated.
  • the viscosity of the paste tends to decrease.
  • the viscosity of the paste tends to be further lowered.
  • an organic acid-based surface treatment agent such as linoleic acid or oleic acid
  • the viscosity of the paste may increase.
  • the barium titanate particles may be surface-treated with a surface treatment agent as long as the viscosity of the paste does not increase.
  • the organic solvent preferably has an OH group. That is, it is preferable that the organic solvent has high hydrophilicity. As a result, the viscosity of the dispersion liquid or the paste tends to decrease.
  • the organic solvent has an OH group and the adsorbed water content is 5 parts by mass or more with respect to 100 parts by mass of the solid content, the viscosity of the dispersion liquid tends to be low.
  • the organic solvent preferably has at least one of an ester bond, an ether bond, and a ketone group together with an OH group. This makes the organic solvent more hydrophilic. In particular, by having an ether bond, high hydrophilicity can be obtained.
  • the organic solvent preferably has a hydrophobic structure together with the OH group.
  • the hydrophobic structure represents a cyclic structure or a chain structure in which two or more carbon atoms are continuously carbon-carbon bonded from the end.
  • the cyclic structure include a cyclic hydrocarbon group (R 6 ) which is a monovalent substituent obtained by removing a hydrogen atom from an arbitrary carbon atom such as cycloalkane, cycloalkene (cycloolefin), and aromatic ring.
  • R 6 may be any of a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, a seven-membered ring, and the like. Illustrating the structure of R 6 six-membered ring in FIG. 1, (a) is a six-membered ring aromatic ring, (b) is a six-membered ring cycloalkene, and (c) is a six-membered ring cycloalkane. In the structure of R 6 , a part of the carbon atom may be replaced with a hetero atom such as oxygen, nitrogen or sulfur atom.
  • R 1 to R 5 can be selected from a hydrophilic group such as a hydrogen group, an OH group and a carboxy group, and a hydrophobic group such as a methyl group, an ethyl group, an isopropyl group and a t-butyl group.
  • R 1 to R 5 may be the same or different.
  • R 1 to R 5 are preferably four hydrogen groups and one methyl group. As a result, the compatibility between the organic solvent and the binder is increased.
  • the organic solvent having a cyclic structure can be represented by R 6 to R 7 (however, R 7 has a structure containing elements such as carbon, hydrogen, nitrogen and oxygen).
  • the OH group is preferably contained in R 7.
  • the organic solvent enhances the compatibility between the binder and the barium titanate particles.
  • 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 can be expressed as R 3- CR 4 R 5- CH 3 by the demonstrative formula.
  • the methyl group (-CH 3 ) is the terminal.
  • the carbon atom bonded 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 are continuously carbon-carbon bonded from the end.
  • R 3 , R 4 and R 5 have a structure containing elements such as carbon, hydrogen, nitrogen and oxygen.
  • R 3 , R 4 and R 5 may be combined to form a cyclic structure.
  • the organic solvent has a hydrophobic structure, it is considered that the compatibility between the organic solvent and the binder is high.
  • the organic solvent has a hydrophobic structure and an OH group, the organic solvent enhances the compatibility between the binder and the barium titanate particles. Therefore, the paste is less likely to aggregate.
  • the number of carbon atoms that form a continuous carbon-carbon bond from the end of the chain structure is preferably 5 or less. This increases the hydrophilicity of the organic solvent. More preferably, the number of carbon atoms in a carbon-carbon bond is 4 or less.
  • the organic solvent has an ether bond, it is preferable that the alkyl group is bonded to the oxygen atom of the ether bond.
  • the alkyl group preferably has 3 to 5 carbon atoms.
  • the solubility parameter (SP value) of the organic solvent is preferably 8.5 or more. When it is 8.5 or more, the hydrophilicity of the organic solvent becomes high.
  • the boiling point of the organic solvent under atmospheric pressure is preferably 300 ° C. or lower.
  • the carbon chain of the organic solvent is shorter than that of the organic solvent having a boiling point higher than 300 ° C. Therefore, the viscosity of the dispersion liquid decreases. Further, since the viscosity of the printing paste is also lowered, the printing paste is easily applied uniformly at the time of printing.
  • the boiling point of the organic solvent under atmospheric pressure is preferably 200 to 300 ° C. As a result, when the paste is applied and dried, the paste is easily dried uniformly with the Ni particles and the barium titanate particles dispersed. Therefore, the effect of delaying the sintering of Ni particles becomes high. In addition, cracks are less likely to occur in the MLCC.
  • the viscosity of the organic solvent is preferably 100 mPa ⁇ s or less at 25 ° C. under atmospheric pressure. As a result, the viscosity of the dispersion liquid is lowered, and the viscosity of the printing paste is also lowered.
  • a hydroxide of barium and an alkyl cellosolve as a solvent are mixed to prepare a mixed solution A (first step).
  • a hydroxide of barium and an alkyl cellosolve as a solvent are mixed to prepare a mixed solution A (first step).
  • the solvent is alkyl cellosolve
  • the viscosity of the dispersion is reduced.
  • the viscosity of the paste is less likely to increase.
  • the water content of the mixed solution A is preferably 5% by mass or less. This makes it difficult for the titanium alkoxide to be hydrolyzed when the titanium alkoxide described later is added. Therefore, the particle size tends to be small.
  • the mixed liquid A may be depressurized or heated before the second step described later to reduce the water content of the mixed liquid A to 5% by mass or less.
  • the mixed solution B preferably has an atomic ratio Ba / Ti of barium and titanium of 0.95 to 1.05. Within this range, crystals other than the perovskite structure are less likely to be formed.
  • the atomic ratio of barium to titanium may be 0.9 to 1.1.
  • Titanium alkoxide is preferably added in a nitrogen atmosphere. This slows down the reaction rate of the titanium alkoxide. Therefore, barium titanate particles having a small particle size and crystallite size can be easily obtained.
  • the structure of the titanium alkoxide is preferably "Ti (OR) 4".
  • R is a hydrocarbon group having 1 to 4 carbon atoms, or a substituted hydrocarbon group in which one or more of these hydrogen atoms are substituted with halogen atoms. Further, R may be the same as or different from each other. With such a structure, the crystallinity of barium titanate particles tends to be high. Specific examples thereof include titanium tetramethoxyde, titanium tetraethoxydo, titanium tetra n propoxide, titanium tetraisopropoxide, titanium tetra n butoxide, titanium tetraisobutoxide and the like.
  • the amount of water added is preferably the number of moles equal to or more than the equivalent amount of titanium alkoxide. As a result, the amount of titanium alkoxide remaining in the mixed solution C without being hydrolyzed is reduced. Therefore, the crystallinity of the barium titanate particles is increased.
  • the mixed liquid C is heated (fourth step). It is preferable to heat at 40 ° C. or higher for 2 to 200 hours. Aging proceeds by this step, and barium titanate particles are generated in the aged product.
  • the heating temperature is 40 ° C. or higher, the particle size distribution tends to be uniform, although it depends on the gel concentration. Furthermore, the crystallinity is improved. Further, a heating temperature of 120 ° C. or lower is industrially easy to handle. When heated for 2 hours or more, the particle size distribution tends to be uniform. Furthermore, the crystallinity tends to improve. If the heating time is 200 hours or less, the particle size and crystallite size tend to be small. More preferably, it is 5 hours or more and 100 hours or less.
  • the water content of the dispersion is adjusted to less than 3% by weight.
  • Organic solvents may be added prior to ultrafiltration or distillation. Ultrafiltration is preferred when the boiling point of the organic solvent is lower than the alkyl cellosolve. If it is higher than alkyl cellosolve, distillation is preferred.
  • the organic solvent preferably has the characteristics of the organic solvent described in the description of the dispersion liquid described above.
  • the dispersion prepared by such a manufacturing method has a small amount of water. Therefore, the viscosity of the paste is less likely to increase.
  • the barium titanate particles in the dispersion have a small particle size and crystallite diameter, and have high crystallinity. Furthermore, since the crystal system of barium titanate particles is close to that of cubic crystals, the effect of delaying the sintering of Ni becomes high when used in the electrode layer.
  • the 2nd, 3rd, lanthanoid, actinoid, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, and 13th groups are preferable to add.
  • a metal salt containing at least one selected from Group 14 and Group 14. By adding such a metal salt, the sintering delay effect is enhanced. Further, since it is a metal salt, it becomes difficult to form crystals other than the perovskite structure. Furthermore, by adding the metal salt prior to the fourth step, the metal salt is dispersed in the barium titanate gel. Therefore, the sintering delay effect tends to be high.
  • Example 1 ⁇ Preparation of dispersion> 50 g of barium hydroxide / octahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 315 g of 2-methoxyethanol (methylcellosolve) were placed in a beaker and dissolved at 30 ° C. for 20 minutes. The Ba concentration of this solution was 6.0% by weight and the water content was 6.2% by weight. This solution was placed in a 1 dm 3 eggplant-shaped flask and distilled with a rotary evaporator to obtain a mixed solution A. The distillation conditions were 1 hour at a temperature of 70 ° C. and a reduced pressure of 0.015 MPa. The Ba concentration of the mixed solution A was 16.0% by weight, and the water content was 0.5% by weight.
  • the dispersion was measured as follows. The measurement results of each Example and Comparative Example are shown in Table 2.
  • ⁇ Measurement of adsorbed water content 30 g of the dispersion was dried at 200 ° C. for 3 hours and cooled in a desiccator to obtain a dry powder. The dry powder was allowed to stand for 1 hour in a constant temperature and humidity chamber (PL-3J manufactured by ESPEC CORPORATION) adjusted to 25 ° C. and 90 RH%. The amount of adsorbed water was calculated from the weight change before and after that.
  • a binder solution was prepared by dispersing 3 g of ethyl cellulose powder in 74 g of tarpineol (manufactured by Yasuhara Chemical Co., Ltd.). 4.5 g of this binder liquid and 3 g of the dispersion liquid were mixed to obtain a paste for measuring viscosity.
  • ⁇ Preparation of paste for dielectric layer> 90 g of barium titanate (manufactured by Sakai Chemical Co., Ltd .: BT-01, average particle size 300 nm) and 10 g of ethyl cellulose powder were added to 56.5 g of a tarpineol solvent and first dispersed using Awatori Rentaro. Further, a paste for a dielectric layer was prepared by secondary dispersion using three rolls.
  • Example 1 In the following Examples and Comparative Examples, each sample was prepared, measured and evaluated in the same manner as in Example 1.
  • 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 71.3 g of water and 214.0 g of methanol.
  • Example 3 Same as Example 1 except that the mixed solution of Example 1 was changed to a mixed solution of nickel acetate tetrahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 2.46 g, water 57.1 g and methanol 171.3 g. A dispersion was obtained.
  • nickel acetate tetrahydrate manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.
  • Example 4 Same as Example 1 except that the mixed solution of Example 1 was changed to a mixed solution of magnesium acetate tetrahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 0.85 g, water 57.1 g and methanol 171.3 g. A dispersion was obtained.
  • Example 5 When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 1.79 g of tin methoxydo (manufactured by Alfa Aesar) was added. Other than that, a dispersion was prepared in the same manner as in Example 1.
  • Example 6 When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 2.02 g of calcium methoxydo (manufactured by Strem Chemicals) was added. A dispersion was obtained in the same manner as in Example 1 except that 178 g of this solution was used.
  • Example 7 When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 0.67 g of tantalum methoxydo (manufactured by Strem Chemicals) was added. Other than that, a dispersion liquid was obtained in the same manner as in Example 1.
  • Example 8 Same as Example 1 except that the mixed solution of Example 1 was changed to a mixed solution of nickel hydroxide / hydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 0.92 g, water 57.1 g and methanol 171.2 g. A dispersion was obtained.
  • nickel hydroxide / hydrate manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.
  • Example 9 When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 0.67 g of dysprosium isopropoxide (manufactured by Fuji Film Wako Chemical Co., Ltd.) was added. Other than that, a dispersion liquid was obtained in the same manner as in Example 1.
  • Example 10 A solution for hydrolysis, which was a mixture of 57.1 g of water and 171.3 g of methanol, was added to the mixed solution B obtained in Example 1 over 1 minute while keeping the temperature at 25 ° C. under stirring. As a result, a hydrate gel was obtained. The hydrate gel was heated to 80 ° C. and aged for 96 hours. Ethanol was mixed with this aged product and ultrafiltration was performed to obtain a dispersion liquid containing 40% by mass of barium titanate.
  • 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 70 g of butyl carbitol (manufactured by Kanto Chemical Co., Inc.) was mixed with the aged product and solvent substitution was performed using a rotary evaporator instead of limit filtration.
  • the solvent replacement conditions were a temperature of 70 ° C. and a reduced pressure of 0.015 MPa 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 The same as in Example 12 except that the hydrolysis solution was changed to a solution of nickel acetate tetrahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 2.46 g, water 57.1 g and methanol 171.3 g. A dispersion was obtained.
  • Example 14 The weight of the mixed solution A was changed to 168 g, and the mixture was dispersed in the same manner as in Example 12 except that 70 g of tarpineol and 3.5 g of linoleic acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were mixed with the aged product instead of butyl carbitol. I got the liquid.
  • Example 15 To the aged product obtained in Example 11, 3.5 g of linoleic acid was added, and the mixture was stirred at 50 ° C. for 15 hours. 70 g of butyl carbitol was added thereto and distilled with a rotary evaporator to obtain a dispersion liquid. The distillation conditions were a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour.
  • Example 16 70 g of tarpineol was added to the aged product obtained in Example 10. Distillation was carried out using a rotary evaporator under the conditions of a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour.
  • Example 17 70 g of triethanolamine was added to the aged product obtained in Example 10. Distillation was carried out using a rotary evaporator under the conditions of a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Power Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Materials Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Wood Science & Technology (AREA)
  • Ceramic Capacitors (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
  • Compositions Of Oxide Ceramics (AREA)

Abstract

Provided are barium titanate particles that exhibit a high sintering delay effect, and a method for producing the same. The perovskite-structured barium titanate particles according to the present invention have a Ba-to-Ti ratio Ba/Ti of 0.95-1.05 and have a crystallite diameter of 5-25 nm.

Description

チタン酸バリウム粒子とその製造方法、チタン酸バリウム粒子の分散液Barium titanate particles and their manufacturing method, dispersion of barium titanate particles
　本発明は、ペロブスカイト構造を持つチタン酸バリウム粒子に関する。 The present invention relates to barium titanate particles having a perovskite structure.
　チタン酸バリウム粒子は、電子部品用の誘電体材料や高屈折率で透明性に優れた光学材料等に用いられている。チタン酸バリウム粒子は、高い誘電率を持つため、積層セラミックコンデンサ（ＭＬＣＣ）に利用されている。ＭＬＣＣは電極層と誘電体層が交互に重なった構造をしている。電極層には、８０～３００ｎｍのＮｉ粒子と、共材としてチタン酸バリウム粒子が含まれている。電極層では、チタン酸バリウム粒子がＮｉ粒子の周りに充填されている。そのため、Ｎｉ粒子同士が焼結する温度が高くなる。すなわち、Ｎｉ粒子の焼結遅延効果が得られる。そのため、Ｎｉ粒子同士が焼結する温度と、誘電体層が焼結する温度とが近くなる。これにより、焼成時に電極層と誘電体層の収縮率の差が小さくなり、クラックの少ないＭＬＣＣが得られる（例えば、特許文献１を参照）。 Barium titanate particles are used as dielectric materials for electronic parts and optical materials with high refractive index and excellent transparency. Barium titanate particles have a high dielectric constant and are therefore used in multilayer ceramic capacitors (MLCCs). The MLCC has a structure in which electrode layers and dielectric layers are alternately overlapped. The electrode layer contains Ni particles having a diameter of 80 to 300 nm and barium titanate particles as a co-material. In the electrode layer, barium titanate particles are packed around the Ni particles. Therefore, the temperature at which Ni particles are sintered is high. That is, the effect of delaying the sintering of Ni particles can be obtained. Therefore, the temperature at which the Ni particles are sintered and the temperature at which the dielectric layer is sintered are close to each other. As a result, the difference in shrinkage between the electrode layer and the dielectric layer becomes small during firing, and an MLCC with few cracks can be obtained (see, for example, Patent Document 1).
　一方で、チタン酸バリウム粒子の誘電率を向上させるために、チタン酸バリウム粒子をペロブスカイト構造とし、さらにその結晶格子のｃ軸の軸長をａ軸の軸長より長くすること、すなわち、チタン酸バリウム粒子を正方晶系とすることが知られている。（例えば、特許文献２を参照）。 On the other hand, in order to improve the dielectric constant of the barium titanate particles, the barium titanate particles have a perovskite structure, and the c-axis axis length of the crystal lattice is made longer than the a-axis axis length, that is, barium titanate. It is known that barium particles are tetragonal. (See, for example, Patent Document 2).
特開２００５－６３７０７号公報Japanese Unexamined Patent Publication No. 2005-63707 特開２００４－３０００２７号公報Japanese Unexamined Patent Publication No. 2004-300027
　特許文献２のチタン酸バリウム粒子では、ペロブスカイト構造のｃ軸長がａ軸長より長いため、誘電率が高い。しかし、チタン酸バリウム粒子は、粉末化された後に焼成されているため、粒子径や結晶子径が大きくなりやすい。そのため、Ｎｉ粒子の周りに充填されるチタン酸バリウム粒子の密度が低くなりやすく、焼結遅延効果が得られにくい。誘電体層が焼結する温度と、Ｎｉ粒子が焼結する温度との差が大きくなる程、ＭＬＣＣにクラックが発生しやすくなる。
　本発明の目的は、焼結遅延効果の高いチタン酸バリウム粒子とその製造方法を提供することにある。 The barium titanate particles of Patent Document 2 have a high dielectric constant because the c-axis length of the perovskite structure is longer than the a-axis length. However, since barium titanate particles are pulverized and then fired, the particle size and crystallite diameter tend to increase. Therefore, the density of the barium titanate particles packed around the Ni particles tends to be low, and it is difficult to obtain the 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 it is that cracks will occur in the MLCC.
An object of the present invention is to provide barium titanate particles having a high sintering delay effect and a method for producing the same.
　そこで、本発明では、ペロブスカイト構造のチタン酸バリウム粒子において、バリウムとチタンの原子比Ｂａ／Ｔｉを０．９～１．１とし、結晶子径を５～２５ｎｍとした。バリウムとチタンの原子比Ｂａ／Ｔｉは０．９５～１．０５でもよい。
　さらに、ペロブスカイト構造における結晶格子のｃ軸とａ軸の長さの比ｃ／ａは１．００５以下が好ましい。
　このようなチタン酸バリウム粒子と、有機溶媒とを含むチタン酸バリウム粒子の分散液では、水分量は３重量％未満が好ましい。
　また、チタン酸バリウム粒子の製造方法は、バリウム水酸化物とアルキルセロソルブを混合する工程と、バリウムとチタンの原子比Ｂａ／Ｔｉが０．９～１．１の範囲となるようにチタンアルコキシドを添加する工程と、水を添加する工程と、加熱する工程を含んでいる。 Therefore, in the present invention, in the barium titanate particles having a perovskite structure, the atomic ratio Ba / Ti of barium and titanium was set to 0.9 to 1.1, and the crystallite diameter was set to 5 to 25 nm. The atomic ratio Ba / Ti of barium and titanium may be 0.95 to 1.05.
Further, the ratio c / a of the lengths of the c-axis and the a-axis of the crystal lattice in the perovskite structure is preferably 1.005 or less.
In such a dispersion of barium titanate particles and barium titanate particles containing an organic solvent, the water content is preferably less than 3% by weight.
The method for producing barium titanate particles is a step of mixing barium hydroxide and alkyl cellosolve, and titanium alkoxide so that the atomic ratio Ba / Ti of barium and titanium is in the range of 0.9 to 1.1. It includes a step of adding, a step of adding water, and a step of heating.
環状炭化水素基（Ｒ６）の構造図である。It is a structural drawing of a cyclic hydrocarbon group (R 6).
　本発明によるペロブスカイト構造のチタン酸バリウム粒子は、バリウムとチタンの原子比Ｂａ／Ｔｉが０．９～１．１の範囲である。これにより、ペロブスカイト構造以外の結晶等の不純物が生成されにくい。また、チタン酸バリウム粒子の結晶子径は５～２５ｎｍである。そのため、チタン酸バリウム粒子の結晶性が高くなり、また、粒子径が小さくなる。このようなチタン酸バリウム粒子が電極層中のＮｉ粒子の隙間に入るため、Ｎｉ粒子の周りにチタン酸バリウム粒子が高密度で存在する。そのため、Ｎｉの焼結遅延効果が高くなる。なお、結晶子径が２５ｎｍより大きいと、後述のチタン酸バリウム粒子の分散液の粘度が高くなる。結晶子径が５～２５ｎｍのとき、透過型電子顕微鏡で測定される粒子径も５～２５ｎｍである。
　また、バリウムとチタンの原子比Ｂａ／Ｔｉは０．９５～１．０５でもよい。
　さらに、ペロブスカイト構造における結晶格子のｃ軸とａ軸の長さの比（軸率）ｃ／ａは１．００５以下が好ましい。これにより、チタン酸バリウム粒子が立方晶に近くなる。そのため、Ｎｉの焼結遅延効果が高くなる。 The barium titanate particles having a perovskite structure according to the present invention have a barium-titanium atomic ratio Ba / Ti in the range of 0.9 to 1.1. As a result, impurities such as crystals other than the perovskite structure are less likely to be generated. The crystallite diameter of the barium titanate particles is 5 to 25 nm. Therefore, the crystallinity of the barium titanate particles becomes high, and the particle size becomes small. Since such barium titanate particles enter the gaps between the Ni particles in the electrode layer, the barium titanate particles are present at a high density around the Ni particles. Therefore, the sintering delay effect of Ni becomes high. When the crystallite diameter is larger than 25 nm, the viscosity of the dispersion liquid of barium titanate particles described later becomes high. When the crystallite diameter is 5 to 25 nm, the particle size measured by a transmission electron microscope is also 5 to 25 nm.
Further, the atomic ratio Ba / Ti of barium and titanium may be 0.95 to 1.05.
Further, the ratio (axial ratio) c / a of the lengths of the c-axis and the a-axis of the crystal lattice in the perovskite structure is preferably 1.005 or less. This makes the barium titanate particles closer to cubic crystals. Therefore, the sintering delay effect of Ni becomes high.
　結晶構造と結晶子径は、Ｘ線回折測定装置であるＲｉｇａｋｕ製ＲＩＮＴ－Ｕｌｔｉｍａを用いて測定できる。結晶構造は、解析ソフトであるＰＤＸＬを用いて同定できる。結晶子径は、２θ＝３１．５°付近のミラー指数（１１０）での半価幅を測定し、半価幅β（ｒａｄ）からＳｃｈｅｒｒｅｒの式「Ｄ＝Ｋλ／βｃｏｓθ」により算出できる。ここで、Ｄは結晶子径（Å）、ＫはＳｃｈｅｒｒｅｒ定数、λはＸ線波長（１．７８８９Å）、θは反射角を表す。
　ＰＤＸＬを用いたＸ線回折測定の結果から、ペロブスカイト構造のａ軸とｃ軸の長さが特定できる。軸率ｃ／ａは１．００３以下が好ましい。１．００１以下がより好ましい。軸率ｃ／ａが小さいほどＮｉの焼結遅延効果が高くなる。 The crystal structure and crystallite diameter can be measured using RINT-Ultima manufactured by Rigaku, which is an X-ray diffraction measuring device. The crystal structure can be identified using PDXL, which is analysis software. The crystallite diameter can be calculated from the half-value width β (rad) by measuring the half-value width at the Miller index (110) near 2θ = 31.5 ° and using Scherrer's formula “D = Kλ / βcosθ”. Here, D is the crystallite diameter (Å), K is the Scherrer constant, λ is the X-ray wavelength (1.7889 Å), and θ is the reflection angle.
From the results of X-ray diffraction measurement using PDXL, the lengths of the a-axis and c-axis of the perovskite structure can be specified. The axial ratio c / a is preferably 1.003 or less. More preferably 1.001 or less. The smaller the axial ratio c / a, the higher the sintering delay effect of Ni.
　チタン酸バリウム粒子には２族、３族、ランタノイド系、アクチノイド系、４族、５族、６族、７族、８族、９族、１０族、１１族、１２族、１３族、および、１４族から選ばれる少なくとも一種の元素（以下、添加元素と称す）が含まれていることが好ましい。これにより、焼結遅延効果が高くなる。添加元素は、チタン酸バリウムの組成式ＢａＴｉＯ３を１００ｍｏｌ％とした場合に、０．１～１０ｍｏｌ％含まれることがより好ましい。これにより、Ｎｉの焼結遅延効果が得られやすい。また、添加元素がこの範囲で含まれていても、ペロブスカイト構造以外のピークは観測されない。 Barium titanate particles include Group 2, Group 3, Lantanoid, Actinoid, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13, and. It is preferable that at least one element selected from Group 14 (hereinafter referred to as an additive element) is contained. As a result, the sintering delay effect is enhanced. It is more preferable that the additive element is contained in an amount of 0.1 to 10 mol% when the composition formula BaTIO 3 of barium titanate is 100 mol%. As a result, the sintering delay effect of Ni can be easily obtained. Moreover, even if the additive element is contained in this range, no peak other than the perovskite structure is observed.
　チタン酸バリウム粒子の分散液を用いて、電極層を印刷するためのペーストが作製できる。チタン酸バリウム粒子の分散液は、チタン酸バリウム粒子と有機溶媒を含んでいる。分散液の水分量は、３重量％未満が好ましい。水分量が少ないと、エチルセルロース等のバインダーを分散液に添加しても、ペーストの粘度が高くなりにくい。ペーストの粘度が高いと、ペーストが均一に塗りにくいため、焼成時に電極層にクラックが発生しやすい。また、分散液の水分量が３重量％以下であると、分散液が凝集しにくくなる。 A paste for printing the electrode layer can be prepared using a dispersion of barium titanate particles. 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. When the water content is small, the viscosity of the paste is unlikely to increase even if a binder such as ethyl cellulose is added to the dispersion liquid. If the viscosity of the paste is high, it is difficult to apply the paste uniformly, so that cracks are likely to occur in the electrode layer during firing. Further, when the water content of the dispersion liquid is 3% by weight or less, the dispersion liquid is less likely to aggregate.
　分散液の固形分に吸着する水分量（吸着水分量）は、固形分１００質量部に対し５質量部以上であることが好ましい。吸着水分量がこの範囲であれば、分散液中のチタン酸バリウム粒子は表面の水酸基が多い。固形分は、分散液を２００℃で３時間乾燥することにより得られる。吸着水分量は、固形分を２５℃で９０ＲＨ％の条件に１時間暴露させた際に、固形分に吸着する水分量である。 The amount of water adsorbed on the solid content of the dispersion liquid (adsorbed water content) is preferably 5 parts by mass or more with respect to 100 parts by mass of the solid content. When the amount of adsorbed water is within this range, the barium titanate particles in the dispersion have many hydroxyl groups on the surface. The solid content is obtained by drying the dispersion at 200 ° C. for 3 hours. The adsorbed water content is the amount of water adsorbed on the solid content when the solid content is exposed to the condition of 90 RH% at 25 ° C. for 1 hour.
　チタン酸バリウム粒子は、表面処理されていないことが好ましい。これにより、ペーストの粘度が低くなりやすい。特に、分散液の水分量が３％以下であると、さらにペーストの粘度が低くなりやすい。リノール酸やオレイン酸等の有機酸系の表面処理剤でチタン酸バリウムが表面処理されると、ペーストの粘度が高くなる場合がある。ただし、ペーストの粘度が高くならないならば、チタン酸バリウム粒子が表面処理剤で表面処理されても構わない。 It is preferable that the barium titanate particles are not surface-treated. As a result, the viscosity of the paste tends to decrease. In particular, when the water content of the dispersion is 3% or less, the viscosity of the paste tends to be further lowered. When barium titanate is surface-treated with an organic acid-based surface treatment agent such as linoleic acid or oleic acid, the viscosity of the paste may increase. However, the barium titanate particles may be surface-treated with a surface treatment agent as long as the viscosity of the paste does not increase.
　有機溶媒は、ＯＨ基を有することが好ましい。すなわち、有機溶媒の親水性が高いことが好ましい。これにより、分散液やペーストの粘度が低くなりやすい。有機溶媒がＯＨ基を有するとき、吸着水分量が固形分１００質量部に対し５質量部以上であると、分散液の粘度が低くなりやすい。 The organic solvent preferably has an OH group. That is, it is preferable that the organic solvent has high hydrophilicity. As a result, the viscosity of the dispersion liquid or the paste tends to decrease. When the organic solvent has an OH group and the adsorbed water content is 5 parts by mass or more with respect to 100 parts by mass of the solid content, the viscosity of the dispersion liquid tends to be low.
　有機溶媒は、ＯＨ基とともに、エステル結合及びエーテル結合、並びにケトン基の少なくとも１つを有することが好ましい。これにより、有機溶媒の親水性がより高くなる。特に、エーテル結合を有することにより、高い親水性が得られる。 The organic solvent preferably has at least one of an ester bond, an ether bond, and a ketone group together with an OH group. This makes the organic solvent more hydrophilic. In particular, by having an ether bond, high hydrophilicity can be obtained.
　あるいは、有機溶媒は、ＯＨ基とともに疎水構造を有することが好ましい。ここで、疎水構造とは、環状構造、または末端から２個以上の炭素原子が連続で炭素－炭素結合した鎖状構造を表している。環状構造として、シクロアルカン・シクロアルケン（シクロオレフィン）・芳香環等の任意の炭素原子から、水素原子を除去した一価の置換基である環状炭化水素基（Ｒ６）が挙げられる。Ｒ６は、三員環、四員環、五員環、六員環、七員環等のいずれでもよい。六員環のＲ６の構造を図１に例示する。図１中、（ａ）は六員環の芳香環、（ｂ）は六員環のシクロアルケン、（ｃ）は六員環のシクロアルカンである。Ｒ６の構造では、炭素原子の一部が酸素や窒素、硫黄原子等のヘテロ原子に置換されていても良い。このとき、ヘテロ原子が結合可能である結合数に応じて、ヘテロ原子に結合する水素原子の数が増減しても構わない。また、Ｒ６の構造では、Ｒ１～Ｒ５は水素基、ＯＨ基、カルボキシ基等の親水基や、メチル基、エチル基、イソプロピル基、ｔ－ブチル基等の疎水基等が選択できる。Ｒ１～Ｒ５は同一であっても異なっていても良い。Ｒ１～Ｒ５は４つの水素基と１つのメチル基であることが好ましい。これにより、有機溶媒とバインダーの相溶性が高くなる。環状構造を有する有機溶媒は、Ｒ６－Ｒ７で表すことができる（ただし、Ｒ７は炭素、水素、窒素、酸素等の元素を含む構造を有する。）。ＯＨ基はＲ７に含まれることが好ましい。これにより、有機溶媒がバインダーとチタン酸バリウム粒子との相溶性を高める。 Alternatively, the organic solvent preferably has a hydrophobic structure together with the OH group. Here, the hydrophobic structure represents a cyclic structure or a chain structure in which two or more carbon atoms are continuously carbon-carbon bonded from the end. Examples of the cyclic structure include a cyclic hydrocarbon group (R 6 ) which is a monovalent substituent obtained by removing a hydrogen atom from an arbitrary carbon atom such as cycloalkane, cycloalkene (cycloolefin), and aromatic ring. R 6 may be any of a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, a seven-membered ring, and the like. Illustrating the structure of R 6 six-membered ring in FIG. In FIG. 1, (a) is a six-membered ring aromatic ring, (b) is a six-membered ring cycloalkene, and (c) is a six-membered ring cycloalkane. In the structure of R 6 , a part of the carbon atom may be replaced with a hetero atom such as oxygen, nitrogen or sulfur atom. At this time, the number of hydrogen atoms bonded to the hetero atom may increase or decrease depending on the number of bonds to which the hetero atom can be bonded. Further, in the structure of R 6 , R 1 to R 5 can be selected from a hydrophilic group such as a hydrogen group, an OH group and a carboxy group, and a hydrophobic group such as a methyl group, an ethyl group, an isopropyl group and a t-butyl group. R 1 to R 5 may be the same or different. R 1 to R 5 are preferably four hydrogen groups and one methyl group. As a result, the compatibility between the organic solvent and the binder is increased. The organic solvent having a cyclic structure can be represented by R 6 to R 7 (however, R 7 has a structure containing elements such as carbon, hydrogen, nitrogen and oxygen). The OH group is preferably contained in R 7. As a result, the organic solvent enhances the compatibility between the binder and the barium titanate particles.
　鎖状構造として、アルキル基等の直鎖状構造やイソプロピル基、ｔｅｒｔ-ブチル基等の分岐構造等が挙げられる。鎖状構造を有する有機溶媒は示性式で、Ｒ３－ＣＲ４Ｒ５－ＣＨ３と表せる。この示性式では、メチル基（-ＣＨ３）が末端である。末端のメチル基に結合している炭素原子が末端から２個目の炭素原子である。すなわち、メチル基の炭素原子と、メチル基に結合している炭素原子が末端から連続で炭素－炭素結合していることになる。ここで、Ｒ３、Ｒ４及びＲ５は炭素、水素、窒素、酸素等の元素を含む構造を有する。Ｒ３、Ｒ４及びＲ５がそれぞれ結合して環状構造になってもよい。有機溶媒が疎水構造を有すると、有機溶媒とバインダーとの相溶性が高くなると考えられる。有機溶媒が疎水構造とＯＨ基を有すると、有機溶媒がバインダーとチタン酸バリウム粒子との相溶性を高める。そのため、ペーストが凝集しにくくなる。鎖状構造の末端から連続で炭素－炭素結合する炭素原子の数は、５個以下であることが好ましい。これにより、有機溶媒の親水性が高くなる。炭素－炭素結合する炭素原子の数は４個以下であることがより好ましい。有機溶媒がエーテル結合を有するとき、アルキル基がエーテル結合の酸素原子に結合していることが好ましい。このアルキル基の炭素原子は３～５個であることが好ましい。 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 can be expressed as R 3- CR 4 R 5- CH 3 by the demonstrative formula. In this formula, the methyl group (-CH 3 ) is the terminal. The carbon atom bonded 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 are continuously carbon-carbon bonded from the end. Here, R 3 , R 4 and R 5 have a structure containing elements such as carbon, hydrogen, nitrogen and oxygen. R 3 , R 4 and R 5 may be combined to form a cyclic structure. When the organic solvent has a hydrophobic structure, it is considered that the compatibility between the organic solvent and the binder is high. When the organic solvent has a hydrophobic structure and an OH group, the organic solvent enhances the compatibility between the binder and the barium titanate particles. Therefore, the paste is less likely to aggregate. The number of carbon atoms that form a continuous carbon-carbon bond from the end of the chain structure is preferably 5 or less. This increases the hydrophilicity of the organic solvent. More preferably, the number of carbon atoms in a carbon-carbon bond is 4 or less. When the organic solvent has an ether bond, it is preferable that the alkyl group is bonded to the oxygen atom of the ether bond. The alkyl group preferably has 3 to 5 carbon atoms.
　有機溶媒の溶解度パラメータ（ＳＰ値）は、８．５以上が好ましい。８．５以上であると、有機溶媒の親水性が高くなる。 The solubility parameter (SP value) of the organic solvent is preferably 8.5 or more. When it is 8.5 or more, the hydrophilicity of the organic solvent becomes high.
　有機溶媒の大気圧下での沸点は、３００℃以下であることが好ましい。これにより、３００℃より高い沸点の有機溶媒よりも、有機溶媒の炭素鎖が短くなる。そのため、分散液の粘度が下がる。また、印刷用のペーストの粘度も下がるため、印刷の際に、印刷用のペーストが均一に塗工されやすい。有機溶媒の大気圧下での沸点は、２００～３００℃であることが好ましい。これにより、ペーストを塗工し乾燥する際に、Ｎｉ粒子とチタン酸バリウム粒子が分散した状態で、均一にペーストが乾燥されやすくなる。そのため、Ｎｉ粒子の焼結遅延効果が高くなる。また、ＭＬＣＣにクラックが発生しにくくなる。沸点が２００～３００℃の有機溶媒がＯＨ基を有すると、分散液とＮｉ粒子とを混合しやすくなる。そのため、ペーストが凝集しにくくなる。ペーストが凝集しにくいと、ペーストが均一に乾燥されやすくなるため、印刷性が上がる。沸点や疎水構造の観点から、有機溶媒はブチルカルビトールが好ましい。
　有機溶媒の粘度は、大気圧下２５℃において１００ｍＰａ・ｓ以下であることが好ましい。これにより、分散液の粘度が下がり、印刷用のペーストの粘度も下がる。 The boiling point of the organic solvent under atmospheric pressure is preferably 300 ° C. or lower. As a result, the carbon chain of the organic solvent is shorter than that of the organic solvent having a boiling point higher than 300 ° C. Therefore, the viscosity of the dispersion liquid decreases. Further, since the viscosity of the printing paste is also lowered, the printing paste is easily applied uniformly at the time of printing. The boiling point of the organic solvent under atmospheric pressure is preferably 200 to 300 ° C. As a result, when the paste is applied and dried, the paste is easily dried uniformly with the Ni particles and the barium titanate particles dispersed. Therefore, the effect of delaying the sintering of Ni particles becomes high. In addition, cracks are less likely to occur in the MLCC. When an organic solvent having a boiling point of 200 to 300 ° C. has an OH group, it becomes easy to mix the dispersion liquid and Ni particles. Therefore, the paste is less likely to aggregate. If the paste does not easily agglomerate, the paste is likely to be dried uniformly, so that the printability is improved. Butylcarbitol is preferable as the organic solvent from the viewpoint of boiling point and hydrophobic structure.
The viscosity of the organic solvent is preferably 100 mPa · s or less at 25 ° C. under atmospheric pressure. As a result, the viscosity of the dispersion liquid is lowered, and the viscosity of the printing paste is also lowered.
　次に、チタン酸バリウム粒子とその分散液の製造方法について説明する。 Next, a method for producing barium titanate particles and their dispersion will be described.
　まず、バリウムの水酸化物と溶媒としてアルキルセロソルブとを混合し、混合液Ａを調製する（第一工程）。バリウムの水酸化物を用いることにより、電極層を焼成する際に、対イオンが誘電体層へ拡散しない。そのため、ＭＬＣＣの性能が高くなりやすい。溶媒がアルキルセロソルブであるため、分散液の粘度が下がる。また、ペーストの粘度が上がりにくくなる。混合液Ａの水分量は、５質量％以下が好ましい。これにより、後述するチタンアルコキシドを添加する際に、チタンアルコキシドが加水分解しにくくなる。そのため、粒子径が小さくなりやすい。後述の第二工程の前に混合液Ａを減圧または加熱し、混合液Ａの水分量を５質量％以下にしてもよい。 First, a hydroxide of barium and an alkyl cellosolve as a solvent are mixed to prepare a mixed solution A (first step). By using barium hydroxide, counterions do not diffuse into the dielectric layer when firing the electrode layer. Therefore, the performance of the MLCC tends to be high. Since the solvent is alkyl cellosolve, the viscosity of the dispersion is reduced. In addition, the viscosity of the paste is less likely to increase. The water content of the mixed solution A is preferably 5% by mass or less. This makes it difficult for the titanium alkoxide to be hydrolyzed when the titanium alkoxide described later is added. Therefore, the particle size tends to be small. The mixed liquid A may be depressurized or heated before the second step described later to reduce the water content of the mixed liquid A to 5% by mass or less.
　次に、混合液Ａにチタンアルコキシドを添加し、混合液Ｂを調製する（第二工程）。混合液Ｂは、バリウムとチタンの原子比Ｂａ／Ｔｉが、０．９５～１．０５であることが好ましい。この範囲であると、ペロブスカイト構造以外の結晶が生成しにくくなる。バリウムとチタンの原子比は０．９～１．１でも構わない。チタンアルコキシドは、窒素雰囲気下で添加されることが好ましい。これにより、チタンアルコキシドの反応速度が下がる。そのため、粒子径や結晶子径の小さいチタン酸バリウム粒子が得られやすい。 Next, titanium alkoxide is added to the mixed solution A to prepare the mixed solution B (second step). The mixed solution B preferably has an atomic ratio Ba / Ti of barium and titanium of 0.95 to 1.05. Within this range, crystals other than the perovskite structure are less likely to be formed. The atomic ratio of barium to titanium may be 0.9 to 1.1. Titanium alkoxide is preferably added in a nitrogen atmosphere. This slows down the reaction rate of the titanium alkoxide. Therefore, barium titanate particles having a small particle size and crystallite size can be easily obtained.
　チタンアルコキシドの構造は「Ｔｉ（ＯＲ）４」であることが好ましい。ここで、Ｒは炭素数１～４の炭化水素基、またはこれらの１つ以上の水素原子がハロゲン原子で置換された置換炭化水素基である。また、Ｒは互いに同一であっても異なっていてもよい。このような構造であれば、チタン酸バリウム粒子の結晶性が高くなりやすい。具体的には、チタンテトラメトキシド、チタンテトラエトキシド、チタンテトラｎプロポキシド、チタンテトライソプロポキシド、チタンテトラｎブトキシド、チタンテトライソブトキシド等が挙げられる。 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 one or more of these hydrogen atoms are substituted with halogen atoms. Further, R may be the same as or different from each other. With such a structure, the crystallinity of barium titanate particles tends to be high. Specific examples thereof include titanium tetramethoxyde, titanium tetraethoxydo, titanium tetra n propoxide, titanium tetraisopropoxide, titanium tetra n butoxide, titanium tetraisobutoxide and the like.
　次に、混合液Ｂに水を添加し、混合液Ｃを調製する（第三工程）。水の添加量は、チタンアルコキシドに対して当量以上のモル数であることが好ましい。これにより、加水分解せずに混合液Ｃに残存するチタンアルコキシドが少なくなる。そのため、チタン酸バリウム粒子の結晶性が高くなる。 Next, water is added to the mixed solution B to prepare the mixed solution C (third step). The amount of water added is preferably the number of moles equal to or more than the equivalent amount of titanium alkoxide. As a result, the amount of titanium alkoxide remaining in the mixed solution C without being hydrolyzed is reduced. Therefore, the crystallinity of the barium titanate particles is increased.
　次に、混合液Ｃを加熱する（第四工程）。４０℃以上で、２～２００時間加熱することが好ましい。この工程により熟成が進み、熟成物中にチタン酸バリウム粒子が生成される。加熱温度が４０℃以上であると、ゲルの濃度によっても異なるが、粒子径分布が均一になりやすい。さらに、結晶性が良くなる。また、１２０℃以下の加熱温度が、工業的に扱いやすい。２時間以上加熱すると、粒子径分布が均一になりやすい。さらに、結晶性が良くなりやすい。加熱時間が２００時間以下だと、粒子径や結晶子径が小さくなりやすい。５時間以上１００時間以下がより好ましい。 Next, the mixed liquid C is heated (fourth step). It is preferable to heat at 40 ° C. or higher for 2 to 200 hours. Aging proceeds by this step, and barium titanate particles are generated in the aged product. When the heating temperature is 40 ° C. or higher, the particle size distribution tends to be uniform, although it depends on the gel concentration. Furthermore, the crystallinity is improved. Further, a heating temperature of 120 ° C. or lower is industrially easy to handle. When heated for 2 hours or more, the particle size distribution tends to be uniform. Furthermore, the crystallinity tends to improve. If the heating time is 200 hours or less, the particle size and crystallite size tend to be small. More preferably, it is 5 hours or more and 100 hours or less.
　第四工程で得られた熟成物を限外濾過または蒸留する（第五工程）。限外濾過または蒸留するとき、分散液の水分量を３重量％未満に調整する。限外濾過または蒸留する前に有機溶媒を添加してもよい。有機溶媒の沸点がアルキルセロソルブより低い場合は、限外濾過が好ましい。アルキルセロソルブより高い場合は、蒸留が好ましい。有機溶媒は、前述の分散液の説明に記載されている有機溶媒の特徴を有することが好ましい。 Ultrafiltration or distillation of the aged product obtained in the 4th step (5th step). When ultrafiltration or distillation, the water content of the dispersion is adjusted to less than 3% by weight. Organic solvents may be added prior to ultrafiltration or distillation. Ultrafiltration is preferred when the boiling point of the organic solvent is lower than the alkyl cellosolve. If it is higher than alkyl cellosolve, distillation is preferred. The organic solvent preferably has the characteristics of the organic solvent described in the description of the dispersion liquid described above.
　このような製造方法により調製された分散液は、水分量が少ない。そのため、ペーストの粘度が上がりにくくなる。また、分散液中のチタン酸バリウム粒子の粒子径や結晶子径が小さく、結晶性が高い。さらに、チタン酸バリウム粒子の晶系が立方晶系に近いため、電極層に用いた際に、Ｎｉの焼結遅延効果が高くなる。 The dispersion prepared by such a manufacturing method has a small amount of water. Therefore, the viscosity of the paste is less likely to increase. In addition, the barium titanate particles in the dispersion have a small particle size and crystallite diameter, and have high crystallinity. Furthermore, since the crystal system of barium titanate particles is close to that of cubic crystals, the effect of delaying the sintering of Ni becomes high when used in the electrode layer.
　また、第四工程よりも前に、２族、３族、ランタノイド系、アクチノイド系、４族、５族、６族、７族、８族、９族、１０族、１１族、１２族、１３族、および、１４族から選ばれる少なくとも一種を含む金属塩を添加することが好ましい。このような金属塩を添加することにより、焼結遅延効果が高くなる。また、金属塩であることにより、ペロブスカイト構造以外の結晶が生成しにくくなる。さらに、第四工程よりも前に、金属塩を添加することにより、金属塩がチタン酸バリウムのゲルに分散される。そのため、焼結遅延効果が高くなりやすい。 Also, before the 4th step, the 2nd, 3rd, lanthanoid, actinoid, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th, and 13th groups. It is preferable to add a metal salt containing at least one selected from Group 14 and Group 14. By adding such a metal salt, the sintering delay effect is enhanced. Further, since it is a metal salt, it becomes difficult to form crystals other than the perovskite structure. Furthermore, by adding the metal salt prior to the fourth step, the metal salt is dispersed in the barium titanate gel. Therefore, the sintering delay effect tends to be high.
　以下に、本発明の実施例を具体的に説明する。各実施例及び比較例の調製条件を表１に記載する。 Hereinafter, examples of the present invention will be specifically described. The preparation conditions of each Example and Comparative Example are shown in Table 1.
　［実施例１］
　＜分散液の調製＞
　水酸化バリウム・八水和物（富士フィルム和光純薬社製）５０ｇと２－メトキシエタノール（メチルセロソルブ）３１５ｇをビーカーに入れ、３０℃で２０分間かけて溶解させた。この溶液のＢａ濃度は６．０重量％、水分含有量が６．２重量％であった。この溶液を１ｄｍ３のナス型フラスコに入れ、ロータリーエバポレーターで蒸留し、混合液Ａを得た。蒸留の条件は、温度７０℃、減圧度０．０１５ＭＰａで１時間とした。混合液ＡのＢａ濃度は１６．０重量％、水分含有量は０．５重量％であった。 [Example 1]
<Preparation of dispersion>
50 g of barium hydroxide / octahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 315 g of 2-methoxyethanol (methylcellosolve) were placed in a beaker and dissolved at 30 ° C. for 20 minutes. The Ba concentration of this solution was 6.0% by weight and the water content was 6.2% by weight. This solution was placed in a 1 dm 3 eggplant-shaped flask and distilled with a rotary evaporator to obtain a mixed solution A. The distillation conditions were 1 hour at a temperature of 70 ° C. and a reduced pressure of 0.015 MPa. The Ba concentration of the mixed solution A was 16.0% by weight, and the water content was 0.5% by weight.
　窒素ガス雰囲気下のグローブボックス内で、混合液Ａ１７０ｇに、テトライソプロポキシチタン（マツモトファインケミカル社製：オルガチックス（登録商標）ＴＡ－１０、Ｔｉ濃度１６．８８重量％）５６．１８ｇを混合し、混合液Ｂを調製した。 In a glove box under a nitrogen gas atmosphere, 56.18 g of tetraisopropoxytitanium (manufactured by Matsumoto Fine Chemical Co., Ltd .: Organix (registered trademark) TA-10, Ti concentration 16.88% by weight) was mixed with 170 g of the mixed solution A. Mixture B was prepared.
　さらに、水５７．１ｇとメタノール１７１．２ｇの混合液を、１分間かけて添加した。添加中、２５℃に保ちながら、撹拌した。これにより、得られた水和物ゲルを８０℃に昇温し、９６時間熟成した。この熟成物を限外濾過し、チタン酸バリウムを４０質量％含む分散液を得た。 Further, a mixed solution of 57.1 g of water and 171.2 g of methanol was added over 1 minute. During the addition, the mixture was stirred while keeping the temperature at 25 ° C. As a result, the obtained hydrate gel was heated to 80 ° C. and aged for 96 hours. The aged product was ultrafiltered to obtain a dispersion containing 40% by mass of barium titanate.
　分散液を下記のように測定した。各実施例及び比較例の測定結果を表２に記載する。 The dispersion was measured as follows. The measurement results of each Example and Comparative Example are shown in Table 2.
　≪水分量の測定≫
　卓上型電量法水分計　ＣＡ－２００型（三菱ケミカルアナリテック社製）を使用して測定した。 ≪Measurement of water content≫
The measurement was performed using a desktop type coulometric moisture meter CA-200 (manufactured by Mitsubishi Chemical Analytech Co., Ltd.).
　≪吸着水分量の測定≫
　分散液３０ｇを２００℃，３時間乾燥し、デシケーター内で冷却することにより、乾燥粉末を得た。２５℃、９０ＲＨ％に調整した恒温恒湿機（エスペック社製ＰＬ－３Ｊ）に乾燥粉末を１時間静置した。その前後の重量変化から吸着水分量を算出した。 ≪Measurement of adsorbed water content≫
30 g of the dispersion was dried at 200 ° C. for 3 hours and cooled in a desiccator to obtain a dry powder. The dry powder was allowed to stand for 1 hour in a constant temperature and humidity chamber (PL-3J manufactured by ESPEC CORPORATION) adjusted to 25 ° C. and 90 RH%. The amount of adsorbed water was calculated from the weight change before and after that.
　≪Ｘ線回折測定≫
　分散液を４００℃で乾燥し、チタン酸バリウム粒子の粉末を得た。この粉末をＲｉｇａｋｕ社製ＲＩＮＴ－Ｕｌｔｉｍａを用いて、Ｘ線回折測定を行った。後述の実施例・比較例においても同様にＸ線回折測定を行った。Ｘ線回折測定では、比較例１以外はペロブスカイト構造以外のＸ線回折のピークは観測されなかった。 ≪X-ray diffraction measurement≫
The dispersion was dried at 400 ° C. to obtain a powder of barium titanate particles. This powder was subjected to X-ray diffraction measurement using RINT-Ultima manufactured by Rigaku. X-ray diffraction measurements were also performed in the examples and comparative examples described later. In the X-ray diffraction measurement, no peak of X-ray diffraction other than the perovskite structure was observed except in Comparative Example 1.
　≪粘度の測定≫
　エチルセルロース粉末３ｇをターピネオール（ヤスハラケミカル社製）７４ｇに分散させることにより、バインダー液を調製した。このバインダー液４．５ｇと分散液３ｇを混合し、粘度測定用のペーストを得た。レオメーターＲＳ３０００（ＨＡＡＫＥ社）を用いて、ｄγ／ｄｔ＝０．１～１０００ｓ－１の範囲で動的粘度測定を行い、ｄｒ／ｄｔ＝４０ｓ－１のときの値を粘度とした。 ≪Viscosity measurement≫
A binder solution was prepared by dispersing 3 g of ethyl cellulose powder in 74 g of tarpineol (manufactured by Yasuhara Chemical Co., Ltd.). 4.5 g of this binder liquid and 3 g of the dispersion liquid were mixed to obtain a paste for measuring viscosity. A dynamic viscosity measurement was performed in the range of dγ / dt = 0.1 to 1000s -1 using a rheometer RS3000 (HAAKE), and the value when dr / dt = 40s -1 was taken as the viscosity.
　≪印刷性の評価≫
　粘度測定用のペーストをガラス板に塗布し、２００℃で乾燥した。乾燥した膜中の凝集物と平滑性を目視で確認し、印刷性を評価した。
◎：凝集物がなく、平滑性に優れている
○：凝集物がほとんどなく、平滑性に優れている
△：凝集物がほとんどなく、平滑性に若干の難がある
×：凝集物が多くみられるまたは平滑性に難がある ≪Evaluation of printability≫
A paste for measuring viscosity was applied to a glass plate and dried at 200 ° C. The agglomerates and smoothness in the dried film were visually confirmed, and the printability was evaluated.
⊚: No agglomerates and excellent smoothness ○: Almost no agglutinates and excellent smoothness Δ: Almost no agglutinates and some difficulty in smoothness ×: Many agglutinates Or have difficulty in smoothness
　＜電極用ペーストの調製＞
　分散液５０ｇ（分散液中のチタン酸バリウムの量は１０ｇ）、粒子径２００ｎｍのＮｉナノ粒子（ＪＦＥミネラル社製：ＮＦＰ３０１ＳＤ）４０ｇ、およびエチルセルロース粉末１０ｇを混合し、シンキー社製の泡取練太郎（登録商標）ＡＲ－２５０を用いて一次分散させた。さらに、三本ロール（井上製作所製：ＨＨＣタイプ）を用いて二次分散させることにより、電極用ペーストを調製した。電極用ペーストの濃度は６０重量％であった。後述の実施例や比較例についても同様に電極用ペーストを調製し、測定・評価した。 <Preparation of electrode paste>
50 g of dispersion liquid (the amount of barium titanate in the dispersion liquid is 10 g), 40 g of Ni nanoparticles (manufactured by JFE Mineral Co., Ltd .: NFP301SD) having a particle size of 200 nm, and 10 g of ethyl cellulose powder are mixed, and Awatori Rentaro manufactured by Shinky Co., Ltd. Primary dispersion was performed using AR-250 (registered trademark). Further, a paste for electrodes was prepared by secondary dispersion using three rolls (manufactured by Inoue Seisakusho: HHC type). The concentration of the electrode paste was 60% by weight. Electrode pastes were similarly prepared, measured and evaluated in Examples and Comparative Examples described later.
　＜誘電体層用ペーストの調製＞
　チタン酸バリウム（堺化学社製：ＢＴ－０１、平均粒子径＝３００ｎｍ）９０ｇとエチルセルロース系粉末１０ｇをターピネオール系溶剤５６．５ｇに添加し、泡取練太郎を用いて一次分散させた。さらに、三本ロールを用いて二次分散させることにより、誘電体層用ペーストを調製した。 <Preparation of paste for dielectric layer>
90 g of barium titanate (manufactured by Sakai Chemical Co., Ltd .: BT-01, average particle size = 300 nm) and 10 g of ethyl cellulose powder were added to 56.5 g of a tarpineol solvent and first dispersed using Awatori Rentaro. Further, a paste for a dielectric layer was prepared by secondary dispersion using three rolls.
　＜積層セラミックコンデンサ（ＭＬＣＣ）の調製＞
　電極用ペーストをチタン酸バリウムセラミックシート（厚さ＝４．０μｍ）上にスクリーン印刷した。これを６００℃で１時間乾燥した。この上に誘電体層用ペーストをスクリーン印刷した。これを６００℃で１時間乾燥した。これらの工程を繰り返し、合計２０層を積層した。この積層体を、Ｈ２を３％含む窒素ガス雰囲気の下、１２００℃、２時間で還元処理した。その後、窒素ガス雰囲気の下、１０００℃で３時間加熱した。 <Preparation of multilayer ceramic capacitors (MLCC)>
The electrode paste was screen-printed on a barium titanate ceramic sheet (thickness = 4.0 μm). This was dried at 600 ° C. for 1 hour. The paste for the dielectric layer was screen-printed on this. This was dried at 600 ° C. for 1 hour. These steps were repeated to stack a total of 20 layers. This laminate was reduced at 1200 ° C. for 2 hours under a nitrogen gas atmosphere containing 3% of H 2. Then, it was heated at 1000 ° C. for 3 hours under a nitrogen gas atmosphere.
　≪クラック数≫
　ＭＬＣＣを垂直に１００μｍ角で切断し、走査型電子顕微鏡（ＳＥＭ）を用いて１０万倍で断面写真を撮影した。１００μｍ角のＭＬＣＣにおいて、各層に存在するクラックを断面写真で確認し、計数した。 ≪Number of cracks≫
The MLCC was cut vertically at 100 μm square, and a cross-sectional photograph was taken at 100,000 times using a scanning electron microscope (SEM). In a 100 μm square MLCC, cracks existing in each layer were confirmed by cross-sectional photographs and counted.
　≪凝集の評価≫
　電極用ペーストをガラス板状に滴下して凝集物の有無を目視判定した。 ≪Evaluation of aggregation≫
The electrode paste was dropped into a glass plate and the presence or absence of agglomerates was visually determined.
　以下の実施例や比較例でも、実施例１と同様に各試料を調製し、測定及び評価した。 In the following Examples and Comparative Examples, each sample was prepared, measured and evaluated in the same manner as in Example 1.
　［実施例２］
　実施例１の混合液を水７１．３ｇおよびメタノール２１４．０ｇの混合液に変更した以外は実施例１と同様に分散液を得た。 [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 71.3 g of water and 214.0 g of methanol.
　［実施例３］
　実施例１の混合液を酢酸ニッケル・四水和物（富士フィルム和光純薬社製）２．４６ｇと水５７．１ｇおよびメタノール１７１．３ｇの混合液に変更した以外は実施例１と同様に分散液を得た。 [Example 3]
Same as Example 1 except that the mixed solution of Example 1 was changed to a mixed solution of nickel acetate tetrahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 2.46 g, water 57.1 g and methanol 171.3 g. A dispersion was obtained.
　［実施例４］
　実施例１の混合液を酢酸マグネシウム・四水和物（富士フィルム和光純薬社製）０．８５ｇと水５７．１ｇおよびメタノール１７１．３ｇの混合液に変更した以外は実施例１と同様に分散液を得た。 [Example 4]
Same as Example 1 except that the mixed solution of Example 1 was changed to a mixed solution of magnesium acetate tetrahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 0.85 g, water 57.1 g and methanol 171.3 g. A dispersion was obtained.
　［実施例５］
　実施例１の水酸化バリウム・八水和物を２－メトキシエタノールに溶解させる際に、スズメトキシド（Ａｌｆａ　Ａｅｓａｒ社製）を１．７９ｇ添加した。それ以外は、実施例１と同様に分散液を調製した。 [Example 5]
When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 1.79 g of tin methoxydo (manufactured by Alfa Aesar) was added. Other than that, a dispersion was prepared in the same manner as in Example 1.
　［実施例６］
　実施例１の水酸化バリウム・八水和物を２－メトキシエタノールに溶解させる際に、カルシウムメトキシド（Ｓｔｒｅｍ　Ｃｈｅｍｉｃａｌｓ社製）を２．０２ｇ添加した。この溶液を１７８ｇ使用した以外は、実施例１と同様に分散液を得た。 [Example 6]
When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 2.02 g of calcium methoxydo (manufactured by Strem Chemicals) was added. A dispersion was obtained in the same manner as in Example 1 except that 178 g of this solution was used.
　［実施例７］
　実施例１の水酸化バリウム・八水和物を２－メトキシエタノールに溶解させる際に、タンタルメトキシド（Ｓｔｒｅｍ　Ｃｈｅｍｉｃａｌｓ社製）を０．６７ｇ添加した。それ以外は、実施例１と同様に分散液を得た。 [Example 7]
When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 0.67 g of tantalum methoxydo (manufactured by Strem Chemicals) was added. Other than that, a dispersion liquid was obtained in the same manner as in Example 1.
　［実施例８］
　実施例１の混合液を水酸化ニッケル・水和物（富士フィルム和光純薬社製）０．９２ｇと水５７．１ｇおよびメタノール１７１．２ｇの混合液に変更した以外は実施例１と同様に分散液を得た。 [Example 8]
Same as Example 1 except that the mixed solution of Example 1 was changed to a mixed solution of nickel hydroxide / hydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 0.92 g, water 57.1 g and methanol 171.2 g. A dispersion was obtained.
　［実施例９］
実施例１の水酸化バリウム・八水和物を２－メトキシエタノールに溶解させる際に、ジスプロシウムイソプロポキシド（富士フィルム和光ケミカル社製）を０．６７ｇ添加した。それ以外は、実施例１と同様に分散液を得た。 [Example 9]
When the barium hydroxide / octahydrate of Example 1 was dissolved in 2-methoxyethanol, 0.67 g of dysprosium isopropoxide (manufactured by Fuji Film Wako Chemical Co., Ltd.) was added. Other than that, a dispersion liquid was obtained in the same manner as in Example 1.
　［実施例１０］
　実施例１で得た混合液Ｂに、水５７．１ｇおよびメタノール１７１．３ｇを混ぜた加水分解用の溶液を、撹拌下で、温度を２５℃に保ちながら、１分間かけて添加した。これにより、水和物ゲルが得られた。この水和物ゲルを８０℃に昇温し、９６時間熟成した。この熟成物にエタノールを混合し、限外濾過を行うことにより、チタン酸バリウムを４０質量％含む分散液を得た。 [Example 10]
A solution for hydrolysis, which was a mixture of 57.1 g of water and 171.3 g of methanol, was added to the mixed solution B obtained in Example 1 over 1 minute while keeping the temperature at 25 ° C. under stirring. As a result, a hydrate gel was obtained. The hydrate gel was heated to 80 ° C. and aged for 96 hours. Ethanol was mixed with this aged product and ultrafiltration was performed to obtain a dispersion liquid containing 40% by mass of barium titanate.
　［実施例１１］
　混合液Ａの重量を１７８ｇに変更した以外は実施例１と同様に混合液Ｂを調製した。熟成物にブチルカルビトール（関東化学社製）７０ｇを混合し、限界ろ過の代わりにロータリーエバポレーターを用い溶媒置換を行ったこと以外は、実施例１と同様に分散液を得た。溶媒置換の条件は、温度７０℃、減圧度０．０１５ＭＰａ、１時間の条件で行った。 [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 70 g of butyl carbitol (manufactured by Kanto Chemical Co., Inc.) was mixed with the aged product and solvent substitution was performed using a rotary evaporator instead of limit filtration. The solvent replacement conditions were a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour.
　［実施例１２］
　混合液Ａの重量を１７０ｇに変更した以外は実施例１１と同様に分散液を得た。 [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.
　［実施例１３］
　加水分解用の溶液を、酢酸ニッケル・四水和物（富士フィルム和光純薬社製）２．４６ｇ、水５７．１ｇおよびメタノール１７１．３ｇの溶液に変更した以外は、実施例１２と同様に分散液を得た。 [Example 13]
The same as in Example 12 except that the hydrolysis solution was changed to a solution of nickel acetate tetrahydrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) 2.46 g, water 57.1 g and methanol 171.3 g. A dispersion was obtained.
　［実施例１４］
混合液Ａの重量を１６８ｇに変更し、ブチルカルビトールの代わりに熟成物にターピネオール７０ｇとリノール酸（富士フィルム和光純薬社製）３．５ｇを混合した以外は、実施例１２と同様に分散液を得た。 [Example 14]
The weight of the mixed solution A was changed to 168 g, and the mixture was dispersed in the same manner as in Example 12 except that 70 g of tarpineol and 3.5 g of linoleic acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were mixed with the aged product instead of butyl carbitol. I got the liquid.
　［実施例１５］
　実施例１１で得られた熟成物にリノール酸３．５ｇを添加して５０℃にて１５時間攪拌した。これにブチルカルビトール７０ｇを添加しロータリーエバポレーターで蒸留し、分散液を得た。蒸留の条件は、温度７０℃、減圧度０．０１５ＭＰａ、１時間とした。 [Example 15]
To the aged product obtained in Example 11, 3.5 g of linoleic acid was added, and the mixture was stirred at 50 ° C. for 15 hours. 70 g of butyl carbitol was added thereto and distilled with a rotary evaporator to obtain a dispersion liquid. The distillation conditions were a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour.
　［実施例１６］
　実施例１０で得られた熟成物に、ターピネオール７０ｇを添加した。ロータリーエバポレーターを用いて、温度７０℃、減圧度０．０１５ＭＰａ、１時間の条件で蒸留した。 [Example 16]
70 g of tarpineol was added to the aged product obtained in Example 10. Distillation was carried out using a rotary evaporator under the conditions of a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour.
　［実施例１７］
　実施例１０で得られた熟成物に、トリエタノールアミン７０ｇを添加した。ロータリーエバポレーターを用いて、温度７０℃、減圧度０．０１５ＭＰａ、１時間の条件で蒸留した。 [Example 17]
70 g of triethanolamine was added to the aged product obtained in Example 10. Distillation was carried out using a rotary evaporator under the conditions of a temperature of 70 ° C. and a reduced pressure of 0.015 MPa for 1 hour.
　［比較例１］
　水酸化バリウム溶液の重量を２０４ｇに変更した以外は、実施例１と同様に分散液を得た。 [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.
　［比較例２］
　炭酸バリウム（富士フィルム和光純薬社製）と酸化チタン粉末（石原産業社製）をＢａ／Ｔｉモル比１．０１となるように計量し、ボールミルを用いて混合した。混合粉を大気中９００℃で焼成し、さらに乳鉢を用いて焼成粉の解砕を行った。 [Comparative Example 2]
Barium carbonate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and titanium oxide powder (manufactured by Ishihara Sangyo Co., Ltd.) were weighed so as to have a Ba / Ti molar ratio of 1.01 and mixed using a ball mill. The mixed powder was calcined in the air at 900 ° C., and the calcined powder was further crushed using a mortar.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
 
Figure JPOXMLDOC01-appb-T000002
 

Claims (8)

  1. 　ペロブスカイト構造のチタン酸バリウム粒子において、
    　バリウムとチタンの原子比Ｂａ／Ｔｉが０．９～１．１であり、
    　結晶子径が５～２５ｎｍであるチタン酸バリウム粒子。     In barium titanate particles with a perovskite structure
    The atomic ratio of barium and titanium, Ba / Ti, is 0.9 to 1.1.
    Barium titanate particles having a crystallite diameter of 5 to 25 nm.
  2. 　バリウムとチタンの原子比Ｂａ／Ｔｉが０．９５～１．０５である請求項１に記載のチタン酸バリウム粒子。 The barium titanate particles according to claim 1, wherein the atomic ratio Ba / Ti of barium and titanium is 0.95 to 1.05.
  3. 　前記ペロブスカイト構造の軸率ｃ／ａが１．００５以下であることを特徴とする請求項１に記載のチタン酸バリウム粒子。 The barium titanate particles according to claim 1, wherein the axial coefficient c / a of the perovskite structure is 1.005 or less.
  4. 　請求項１に記載のチタン酸バリウム粒子と、有機溶媒とを含むチタン酸バリウム粒子の分散液であって、
    　水分量が３重量％未満であることを特徴とする分散液。     A dispersion liquid of barium titanate particles containing the barium titanate particles according to claim 1 and an organic solvent.
    A dispersion liquid having a water content of less than 3% by weight.
  5. 　前記有機溶媒がＯＨ基を有するとともに、
    　当該分散液を２００℃で３時間乾燥させた後、２５℃で９０ＲＨ％の条件に１時間暴露させた際の吸着水分量が分散液の固形分１００質量部に対し５質量部以上である請求項４に記載の分散液。     The organic solvent has an OH group and
    A claim that the amount of adsorbed water when the dispersion liquid is dried at 200 ° C. for 3 hours and then exposed to a condition of 90 RH% at 25 ° C. for 1 hour is 5 parts by mass or more with respect to 100 parts by mass of the solid content of the dispersion liquid. Item 4. The dispersion liquid according to Item 4.
  6. 　前記有機溶媒が、環状構造、または末端から２個以上の炭素原子が連続で炭素－炭素結合した鎖状構造を有することを特徴とする請求項５に記載の分散液。 The dispersion liquid according to claim 5, wherein the organic solvent has a cyclic structure or a chain structure in which two or more carbon atoms are continuously carbon-carbon bonded from the end.
  7. 　前記有機溶媒がエーテル結合を有し、
    　前記有機溶媒の沸点が２００～３００℃であることを特徴とする請求項５または６に記載の分散液。     The organic solvent has an ether bond and
    The dispersion liquid according to claim 5 or 6, wherein the organic solvent has a boiling point of 200 to 300 ° C.
  8. 　バリウム水酸化物とアルキルセロソルブを混合し、混合液Ａを調製する第一工程と、
    　前記混合液Ａに、バリウムとチタンの原子比Ｂａ／Ｔｉが０．９～１．１の範囲となるようにチタンアルコキシドを添加し、混合液Ｂを調製する第二工程と、
    　前記混合液Ｂに水を添加し、混合液Ｃを調製する第三工程と、
    　前記混合液Ｃを加熱する第四工程と、を含むチタン酸バリウム粒子の製造方法。     The first step of mixing barium hydroxide and alkyl cellosolve to prepare a mixed solution A, and
    The second step of preparing the mixed solution B by adding titanium alkoxide to the mixed solution A so that the atomic ratio Ba / Ti of barium and titanium is in the range of 0.9 to 1.1.
    The third step of adding water to the mixed solution B to prepare the mixed solution C, and
    A method for producing barium titanate particles, which comprises a fourth step of heating the mixed solution C.
PCT/JP2020/037304 2019-09-30 2020-09-30 Barium titanate particles, method for producing same, and dispersion of barium titanate particles WO2021066070A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2021551421A JPWO2021066070A1 (en) 2019-09-30 2020-09-30
KR1020217037796A KR20220074821A (en) 2019-09-30 2020-09-30 Barium titanate particles and method for producing the same, dispersion of barium titanate particles
CN202080042148.5A CN113939476B (en) 2019-09-30 2020-09-30 Barium titanate particles, method for producing same, and dispersion of barium titanate particles

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2019180798 2019-09-30
JP2019-180808 2019-09-30
JP2019180808 2019-09-30
JP2019-180798 2019-09-30

Publications (1)

Publication Number Publication Date
WO2021066070A1 true WO2021066070A1 (en) 2021-04-08

Family

ID=75337050

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/037304 WO2021066070A1 (en) 2019-09-30 2020-09-30 Barium titanate particles, method for producing same, and dispersion of barium titanate particles

Country Status (5)

Country Link
JP (1) JPWO2021066070A1 (en)
KR (1) KR20220074821A (en)
CN (1) CN113939476B (en)
TW (1) TW202116682A (en)
WO (1) WO2021066070A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012240904A (en) * 2011-05-24 2012-12-10 Jgc Catalysts & Chemicals Ltd Method for producing crystalline titanic acid salt, and crystalline titanic acid salt
JP2018172242A (en) * 2017-03-31 2018-11-08 日揮触媒化成株式会社 Sol comprising titanic acid alkali earth metal particles, production method thereof and paste comprising the same
JP2019026542A (en) * 2017-08-03 2019-02-21 三菱ケミカル株式会社 Method for producing composite oxide particle, composite oxide particle powder, dispersion liquid and dielectric for capacitor

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09106925A (en) * 1995-10-13 1997-04-22 Mitsubishi Materials Corp Method of manufacturing layered ceramic capacitor
WO2003004416A1 (en) 2001-07-04 2003-01-16 Showa Denko K. K. Barium titanate and its production method
JP2004142964A (en) * 2002-10-22 2004-05-20 Murata Mfg Co Ltd Paste, laminated ceramic electronic component and their manufacturing processes
JP2004269325A (en) * 2003-03-10 2004-09-30 Murata Mfg Co Ltd Method of manufacturing ceramic paste, and method of manufacturing laminated ceramic electronic component using ceramic paste
JP2004277263A (en) * 2003-03-18 2004-10-07 Nippon Chemicon Corp Method for producing dielectric porcelain composition, and ceramic capacitor using the dielectric porcelain composition produced thereby
JP4223848B2 (en) * 2003-03-24 2009-02-12 Ｔｄｋ株式会社 Method for producing conductive composition, and method for producing conductive paste
JP2005063707A (en) 2003-08-20 2005-03-10 Daiken Kagaku Kogyo Kk Electrode paste, and manufacturing method of ceramic electronic component
KR100708488B1 (en) * 2006-06-16 2007-04-18 한국화학연구원 Highly dispersible crystalline barium titanate in organic medium and the method of preparing the same
CN101350240B (en) * 2007-07-17 2011-02-02 深圳振华富电子有限公司 Stacking slice type piezoresistor and manufacturing method thereof
CN107731343A (en) * 2016-08-03 2018-02-23 南安市威速电子科技有限公司 A kind of electronic device electrode slurry and preparation method thereof
CN110092657B (en) * 2019-04-25 2021-01-26 苏州宝顺美科技有限公司 Nano barium titanate microcrystal and preparation method thereof, and barium titanate powder and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012240904A (en) * 2011-05-24 2012-12-10 Jgc Catalysts & Chemicals Ltd Method for producing crystalline titanic acid salt, and crystalline titanic acid salt
JP2018172242A (en) * 2017-03-31 2018-11-08 日揮触媒化成株式会社 Sol comprising titanic acid alkali earth metal particles, production method thereof and paste comprising the same
JP2019026542A (en) * 2017-08-03 2019-02-21 三菱ケミカル株式会社 Method for producing composite oxide particle, composite oxide particle powder, dispersion liquid and dielectric for capacitor

Also Published As

Publication number Publication date
JPWO2021066070A1 (en) 2021-04-08
CN113939476B (en) 2024-05-14
TW202116682A (en) 2021-05-01
CN113939476A (en) 2022-01-14
KR20220074821A (en) 2022-06-03

Similar Documents

Publication Publication Date Title
EP1130004B1 (en) Manufacturing method for oxide having perovskite structure
TW419685B (en) Dielectric ceramic, method for producing the same, laminated ceramic electronic element, and method for producing the same
US4710227A (en) Dispersion process for ceramic green body
TWI422551B (en) Dielectric ceramic composition and temperature compensation laminated capacitor
JP6641178B2 (en) Dielectric porcelain composition, method for producing the same, and ceramic electronic component
JP6517012B2 (en) Method of manufacturing dielectric ceramic particles and dielectric ceramic
Liu et al. Comprehensive dielectric performance of bismuth acceptor doped BaTiO 3 based nanocrystal thin film capacitors
JP2010067418A (en) Conductive paste and method of manufacturing the same
JP7025125B2 (en) A sol containing alkaline earth metal particles of titanate, a method for producing the sol, and a paste containing the sol.
JP3804474B2 (en) Method for producing ceramic raw material powder
Chiang et al. Effect of TiO2 doped Ni electrodes on the dielectric properties and microstructures of (Ba0. 96Ca0. 04)(Ti0. 85Zr0. 15) O3 multilayer ceramic capacitors
JP2013012418A (en) Oxide conductor paste using oxide conductor, and multilayer electronic component using the same
WO2021066070A1 (en) Barium titanate particles, method for producing same, and dispersion of barium titanate particles
JP2018090458A (en) Dielectric ceramic composition and manufacturing method therefor, and ceramic electronic component
JP2011210826A (en) Multilayer ceramic capacitor and method of manufacturing the same
JP5410124B2 (en) Method for manufacturing dielectric material
JP4914065B2 (en) Nickel powder for multilayer ceramic capacitor electrode, electrode forming paste and multilayer ceramic capacitor
JP6759084B2 (en) Barium titanate fine particles and their dispersion and method for producing barium titanate fine particles
JP2019094223A (en) Composite oxide material mainly containing titanate compound
US20040009350A1 (en) Methods of heat treating barium titanate-based particles and compositions formed from the same
Li et al. Medium temperature sintered BaTiO 3-based X8R ceramics with Bi 2 O 3–TiO 2–ZnO–H 2 BO 3 additive
WO2016006498A1 (en) Solid electrolyte, multilayer electronic component, and method for producing multilayer electronic component
JP2021042105A (en) Titanic acid alkaline earth metal composition, method for producing the same, and paste containing the same
JP4780272B2 (en) Composite conductive particle powder, conductive paint containing the composite conductive particle powder, and multilayer ceramic capacitor
JP4894908B2 (en) Dielectric porcelain composition

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20870632

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2021551421

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20870632

Country of ref document: EP

Kind code of ref document: A1