Binder composition for dielectric layer, slurry composition for dielectric layer, dielectric layer, and laminated ceramic capacitor

Abstract

An objective of the present invention is to provide a binder composition, for a dielectric layer, that can endow the dielectric layer with excellent crack resistance and lamination properties. The present invention pertains to the binder composition for the dielectric layer, the binder composition including a copolymer containing a cyano group-containing monomer unit and a (meth)acrylic acid ester monomer unit, wherein the content percentage of the cyano group-containing monomer unit is 10 mass% to 45 mass% when all repeating units contained in the copolymer are set as 100 mass%.

Description

Binder composition for dielectric layer, slurry composition for dielectric layer, dielectric layer, and multilayer ceramic capacitor

[0001] The present invention relates to a binder composition for a dielectric layer, a slurry composition for a dielectric layer, a dielectric layer, and a multilayer ceramic capacitor.

[0002] Multilayer ceramic capacitors are generally manufactured using dielectric layers such as ceramic green sheets. The dielectric layers can be obtained, for example, by first preparing a slurry composition containing a binder, a dielectric material, and a solvent, then applying the slurry composition to a release substrate, and then drying the resulting composition. The resulting dielectric layers are then stacked, optionally subjected to a degreasing treatment (binder removal treatment), and sintered to obtain a multilayer ceramic capacitor.

[0003] In recent years, in order to impart excellent properties to multilayer ceramic capacitors, development of binders to be contained in slurry compositions used in the production of dielectric layers has been progressing. For example, Patent Document 1 proposes a binder for producing inorganic sintered bodies, which contains a binder resin composition having a predetermined gel fraction and containing a predetermined composite resin, as a binder with excellent thermal decomposition properties that can realize high porosity when used as a binder for producing ceramic green sheets and can produce ceramic green sheets that are less likely to suffer from defects such as cracks when producing sintered bodies.

[0004] JP 2018-165230 A

[0005] Here, in dielectric layers of ceramic green sheets and the like, further improvements are required in terms of suppressing cracks that occur during the production of sintered bodies (hereinafter, this may be referred to as "crack resistance").

[0006] Furthermore, in the manufacture of multilayer ceramic capacitors, dielectric layers are typically stacked on top of each other and pressed together to obtain a laminate, and it is desirable that the dielectric layers in the obtained laminate are well bonded to each other (hereinafter, this may be referred to as "laminability").

[0007] Therefore, an object of the present invention is to provide a binder composition for a dielectric layer that can impart excellent crack resistance and lamination properties to a dielectric layer. Another object of the present invention is to provide a slurry composition for a dielectric layer that can impart excellent crack resistance and lamination properties to a dielectric layer. Another object of the present invention is to provide a dielectric layer that has excellent crack resistance and lamination properties. Another object of the present invention is to provide a multilayer ceramic capacitor obtained by sintering a laminate in which the above-mentioned dielectric layers are stacked.

[0008] The present inventors have conducted extensive research with the aim of solving the above-mentioned problems, and have newly discovered that the above-mentioned problems can be solved by a binder composition for a dielectric layer that includes a copolymer containing a cyano group-containing monomer unit and a (meth)acrylic acid ester monomer unit, and that has a content ratio of the cyano group-containing monomer unit within a predetermined range, and have completed the present invention based on this discovery.

[0009] That is, the present invention aims to advantageously solve the above-mentioned problems. [1] The present invention provides a binder composition for a dielectric layer, comprising a copolymer containing a cyano group-containing monomer unit and a (meth)acrylic acid ester monomer unit, wherein the content of the cyano group-containing monomer unit is 10% by mass or more and 45% by mass or less, where the total amount of all repeating units contained in the copolymer is 100% by mass. Such a binder composition for a dielectric layer can impart excellent crack resistance and lamination properties to the dielectric layer. Furthermore, in the production of a multilayer ceramic capacitor, for example, the dielectric layer is stacked on another layer and pressed together, and then the dielectric layer is peeled from the release substrate. However, such a binder composition for a dielectric layer can prevent the dielectric layer from remaining on the release substrate when the dielectric layer is peeled from the release substrate. In other words, such a binder composition for a dielectric layer can impart excellent transferability to the dielectric layer. In this specification, "(meth)acrylic" refers to acrylic and / or methacrylic. In this specification, the content ratio of various repeating units (monomer units) in a (co)polymer is １ It can be measured using a nuclear magnetic resonance (NMR) method such as H-NMR.

[0010] [2] In the binder composition for a dielectric layer according to [1] above, the glass transition temperature of the copolymer is preferably −50° C. or higher and 50° C. or lower. If the glass transition temperature of the copolymer is equal to or higher than the lower limit, the crack resistance of the resulting dielectric layer can be improved. On the other hand, if the glass transition temperature of the copolymer is equal to or lower than the upper limit, the lamination property and transfer property of the resulting dielectric layer can be improved. In this specification, the glass transition temperature of the copolymer can be measured according to the method described in the examples.

[0011] [3] In the binder composition for a dielectric layer according to the above [1] or [2], the copolymer is preferably a particulate copolymer. If the copolymer is a particulate copolymer, the lamination property of the resulting dielectric layer can be improved.

[0012] [4] In the binder composition for a dielectric layer according to [3] above, the volume average particle diameter of the particulate copolymer is preferably 0.01 μm or more and 0.5 μm or less. If the volume average particle diameter of the particulate copolymer is equal to or greater than the lower limit, the crack resistance of the resulting dielectric layer can be improved. On the other hand, if the volume average particle diameter of the particulate copolymer is equal to or less than the upper limit, the lamination property and transferability of the resulting dielectric layer can be improved. In this specification, the volume average particle diameter of the particulate copolymer means the particle diameter at which the cumulative volume calculated from the smallest diameter side in the particle size distribution (volume basis) obtained by measurement using a laser diffraction method accounts for 50% of the total volume, and can be measured according to the method described in the Examples.

[0013] [5] In the binder composition for a dielectric layer according to any one of [1] to [4] above, the content of the (meth)acrylic acid ester monomer unit is preferably 55% by mass or more and 90% by mass or less, when the total amount of all repeating units contained in the copolymer is taken as 100% by mass. If the content of the (meth)acrylic acid ester monomer unit is equal to or more than the lower limit, the lamination property and transferability of the resulting dielectric layer can be improved. On the other hand, if the content of the (meth)acrylic acid ester monomer unit is equal to or less than the upper limit, the crack resistance of the resulting dielectric layer can be improved.

[0014] Another object of the present invention is to advantageously solve the above-mentioned problems. [6] The present invention is a slurry composition for a dielectric layer, comprising the binder composition for a dielectric layer according to any one of [1] to [5] above, a dielectric material, and a solvent. The above-mentioned slurry composition for a dielectric layer can impart excellent crack resistance and lamination properties to the dielectric layer. Furthermore, the above-mentioned slurry composition for a dielectric layer can impart excellent transferability to the dielectric layer.

[0015] [7] In the slurry composition of [6] above, the solvent is preferably water. If the solvent is water, the environmental load can be reduced. Furthermore, if the solvent is water, safety and availability can be improved.

[0016] Another object of the present invention is to advantageously solve the above-mentioned problems. [8] The present invention is a dielectric layer obtained by drying a coating film made of the dielectric layer slurry composition described in [6] or [7] above. The dielectric layer as described above has excellent crack resistance and lamination properties. Furthermore, since the dielectric layer as described above has excellent transferability, it is easy to handle, and as a result, multilayer ceramic capacitors can be produced efficiently.

[0017] Another object of the present invention is to advantageously solve the above-mentioned problems. [9] The present invention provides a multilayer ceramic capacitor obtained by sintering a laminate in which the dielectric layers described in [8] are stacked. The multilayer ceramic capacitor described above has excellent performance because it uses dielectric layers that are excellent in crack resistance and lamination properties. Furthermore, the multilayer ceramic capacitor described above has excellent productivity because it uses dielectric layers that are easy to handle.

[0018] According to the present invention, a binder composition for a dielectric layer can be provided that can impart excellent crack resistance and lamination properties to a dielectric layer. Furthermore, according to the present invention, a slurry composition for a dielectric layer can be provided that can impart excellent crack resistance and lamination properties to a dielectric layer. Furthermore, according to the present invention, a dielectric layer that is excellent in crack resistance and lamination properties can be provided. Furthermore, according to the present invention, a multilayer ceramic capacitor can be provided by sintering a laminate in which the above-mentioned dielectric layers are stacked.

[0019] 1 is a schematic cross-sectional view showing an example of a multilayer ceramic capacitor of the present invention.

[0020] Hereinafter, embodiments of the present invention will be described in detail. Herein, the binder composition for a dielectric layer of the present invention (hereinafter sometimes simply referred to as the "binder composition") can be used to prepare a slurry composition for a dielectric layer of the present invention (hereinafter sometimes simply referred to as the "slurry composition"). The slurry composition of the present invention can be used to form a dielectric layer used in the manufacture of a multilayer ceramic capacitor or the like. Furthermore, the dielectric layer of the present invention is formed by drying a coating film made of the slurry composition of the present invention. Furthermore, the multilayer ceramic capacitor of the present invention is formed by stacking dielectric layers formed using the slurry composition of the present invention and sintering the resulting laminate.

[0021] (Binder Composition for Dielectric Layer) The binder composition for a dielectric layer of the present invention includes a copolymer containing a cyano group-containing monomer unit and a (meth)acrylic acid ester monomer unit, and may optionally contain a solvent. The binder composition of the present invention may also optionally contain components other than the copolymer and the solvent (hereinafter, sometimes referred to as "other components"). In the binder composition of the present invention, the content of the cyano group-containing monomer unit is 10% by mass or more and 45% by mass or less, where the total amount of all repeating units (total monomer units) contained in the copolymer is 100% by mass. The binder composition described above can impart excellent crack resistance and lamination properties to the dielectric layer. This is presumably because the copolymer contained in the binder composition contains a predetermined proportion of the cyano group-containing monomer unit and the (meth)acrylic acid ester monomer unit, which effectively improves both the durability of the dielectric layer during sintering and the adhesion between the dielectric layers. Furthermore, the binder composition as described above can impart excellent transferability to the dielectric layer. Note that, in this specification, the binder composition generally does not contain the dielectric material described below.

[0022] <Copolymer> The copolymer contained in the binder composition of the present invention is a component that can function as a binder, and contains a predetermined ratio of cyano group-containing monomer units and (meth)acrylic acid ester monomer units, and may optionally further contain monomer units other than the cyano group-containing monomer units and (meth)acrylic acid ester monomer units (hereinafter, may be referred to as "other monomer units").

[0023] <<Cyano Group-Containing Monomer Unit>> The cyano group-containing monomer unit is a monomer unit that can be formed by a cyano group-containing monomer. Examples of cyano group-containing monomers include acrylonitrile; methacrylonitrile, α-alkylacrylonitrile such as α-ethylacrylonitrile; and the like. These may be used alone or in combination of two or more in any ratio. Among these, acrylonitrile and methacrylonitrile are preferred as the cyano group-containing monomer, and acrylonitrile is more preferred. That is, the copolymer preferably contains at least one of an acrylonitrile unit and a methacrylonitrile unit, and more preferably contains an acrylonitrile unit.

[0024] The content of the cyano group-containing monomer unit must be 10% by mass or more, preferably 15% by mass or more, and must be 45% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less, when the total repeating units (total monomer units) contained in the copolymer is 100% by mass. If the content of the cyano group-containing monomer unit is equal to or greater than the lower limit, the crack resistance of the resulting dielectric layer can be improved. On the other hand, if the content of the cyano group-containing monomer unit is equal to or less than the upper limit, the lamination property and transferability of the resulting dielectric layer can be improved.

[0025] <<(Meth)acrylic Acid Ester Monomer Unit>> The (meth)acrylic acid ester monomer unit is a monomer unit that can be formed by a (meth)acrylic acid ester monomer. Examples of the (meth)acrylic acid ester monomer include (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, and octyl (meth)acrylate such as 2-ethylhexyl (meth)acrylate. These may be used alone or in combination of two or more. Among these, as the (meth)acrylic acid ester monomer, ethyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred, and ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate are more preferred. That is, the copolymer preferably contains at least one monomer unit selected from the group consisting of ethyl (meth)acrylate units, n-butyl (meth)acrylate units, and 2-ethylhexyl (meth)acrylate units, and more preferably contains at least one monomer unit selected from the group consisting of ethyl acrylate units, n-butyl acrylate units, and 2-ethylhexyl acrylate units. In this specification, "(meth)acrylate" means acrylate and / or methacrylate.

[0026] The content of the (meth)acrylic acid ester monomer units is preferably 55% by mass or more, more preferably 70% by mass or more, and even more preferably 75% by mass or more, and must be 90% by mass or less, and preferably 85% by mass or less, when the total repeating units (total monomer units) contained in the copolymer is 100% by mass. If the content of the (meth)acrylic acid ester monomer units is equal to or greater than the lower limit, the lamination property and transferability of the resulting dielectric layer can be improved. On the other hand, if the content of the (meth)acrylic acid ester monomer units is equal to or less than the upper limit, the crack resistance of the resulting dielectric layer can be improved.

[0027] <<Other Monomer Units>> The other monomer units are monomer units that can be formed by other monomers. The other monomers are not particularly limited as long as they are monomers that can copolymerize with the above-mentioned monomers. Examples of the other monomer units include acid group-containing monomer units.

[0028] The acid group-containing monomer unit is a monomer unit that can be formed by an acid group-containing monomer, such as a carboxylic acid group-containing monomer or a sulfonic acid group-containing monomer.

[0029] Examples of carboxylic acid group-containing monomers include monocarboxylic acids and their derivatives, dicarboxylic acids and their acid anhydrides, and derivatives thereof. Examples of monocarboxylic acids include acrylic acid, methacrylic acid, and crotonic acid. Examples of monocarboxylic acid derivatives include 2-ethylacrylic acid, isocrotonic acid, α-acetoxyacrylic acid, β-trans-aryloxyacrylic acid, and α-chloro-β-E-methoxyacrylic acid. Examples of dicarboxylic acids include maleic acid, fumaric acid, and itaconic acid. Examples of dicarboxylic acid derivatives include methylmaleic acid, dimethylmaleic acid, phenylmaleic acid, chloromaleic acid, dichloromaleic acid, fluoromaleic acid, and maleic acid monoesters such as butyl maleate, nonyl maleate, decyl maleate, dodecyl maleate, octadecyl maleate, and fluoroalkyl maleates. Examples of dicarboxylic acid anhydrides include maleic anhydride, acrylic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, and citraconic anhydride. Acid anhydrides that generate carboxylic acid groups upon hydrolysis can also be used as the carboxylic acid group-containing monomer. Furthermore, ethylenically unsaturated polycarboxylic acids such as butenetricarboxylic acid, and partial esters of ethylenically unsaturated polycarboxylic acids such as monobutyl fumarate and mono-2-hydroxypropyl maleate can also be used as the carboxylic acid group-containing monomer.

[0030] Examples of sulfonic acid group-containing monomers include vinyl sulfonic acid (ethylene sulfonic acid), methyl vinyl sulfonic acid, (meth)allyl sulfonic acid, and 3-allyloxy-2-hydroxypropane sulfonic acid. In this specification, "(meth)allyl" means allyl and / or methallyl.

[0031] In one embodiment, the acid group-containing monomer is preferably acrylic acid, methacrylic acid, itaconic acid, or vinyl sulfonic acid. That is, when the copolymer contains an acid group-containing monomer unit, the acid group-containing monomer unit is preferably at least one selected from the group consisting of an acrylic acid unit, a methacrylic acid unit, an itaconic acid unit, and a vinyl sulfonic acid unit.

[0032] The content of the acid group-containing monomer units is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and preferably 10% by mass or less, and more preferably 5% by mass or less, when the total repeating units (total monomer units) contained in the copolymer is taken as 100% by mass. If the content of the acid group-containing monomer units is equal to or greater than the above-mentioned lower limit, the dispersion stability of the copolymer in the binder composition and the slurry composition can be improved. On the other hand, if the content of the acid group-containing monomer units is equal to or less than the above-mentioned upper limit, the blocking resistance of the resulting dielectric layer can be improved.

[0033] <<Properties of Copolymer>> The glass transition temperature of the copolymer is preferably −50° C. or higher, more preferably −45° C. or higher, and preferably 50° C. or lower, more preferably 10° C. or lower. If the glass transition temperature of the copolymer is equal to or higher than the lower limit, the crack resistance of the resulting dielectric layer can be improved. On the other hand, if the glass transition temperature of the copolymer is equal to or lower than the upper limit, the lamination property and transfer property of the resulting dielectric layer can be improved.

[0034] The copolymer contained in the binder composition of the present invention is preferably a particulate copolymer, which can improve the lamination properties of the resulting dielectric layer.

[0035] The copolymer contained in the binder composition of the present invention is preferably water-insoluble. Herein, the term "water-insoluble" means that when 0.5 g of the copolymer is dissolved in 100 g of water at 25° C., the insoluble content is 90 mass % or more.

[0036] In the binder composition of the present invention, when the copolymer is a particulate copolymer, the average particle diameter of the particulate copolymer is preferably 0.01 μm or more, more preferably 0.1 μm or more, and preferably 0.5 μm or less, more preferably 0.3 μm or less. If the volume average particle diameter of the particulate copolymer is not less than the above lower limit, the crack resistance of the resulting dielectric layer can be improved. On the other hand, if the volume average particle diameter of the particulate copolymer is not more than the above upper limit, the lamination property and transfer property of the resulting dielectric layer can be improved.

[0037] <<Copolymerization Method>> The copolymer polymerization method is not particularly limited, and any method such as solution polymerization, suspension polymerization, bulk polymerization, or emulsion polymerization may be used. Furthermore, addition polymerization such as ionic polymerization, radical polymerization, or living radical polymerization may be used as the polymerization reaction. Furthermore, polymerization solvents and additives such as emulsifiers, dispersants, polymerization initiators, and chain transfer agents that can be used in the polymerization may be commonly used ones, and the amounts used may be the same as commonly used amounts.

[0038] <Solvent> The solvent that can be optionally contained in the binder composition of the present invention is not particularly limited, and both water and organic solvents can be used. As the organic solvent, for example, aqueous solvents such as lower alcohols such as methanol, ethanol, isopropanol, etc., and non-aqueous solvents such as methylbenzene (toluene), xylene, etc. can be used. Note that, from the viewpoints of reducing the environmental load, safety, and easy availability, it is preferable that the solvent that can be optionally contained in the binder composition of the present invention is water.

[0039] <Other Components> The binder composition of the present invention may optionally contain other components, such as the additives used in polymerizing the copolymer.

[0040] <Solid content concentration of binder composition for dielectric layer> The solid content concentration of the binder composition is preferably 20% by mass or more, preferably 30% by mass or more, and is preferably 60% by mass or less, and more preferably 50% by mass or less.

[0041] <Method for preparing binder composition for dielectric layer> The binder composition of the present invention can be prepared by mixing the above-mentioned copolymer, any solvent, and other components by a known method. Specifically, the binder composition can be prepared by mixing the above-mentioned components using a mixer such as a ball mill, a sand mill, a bead mill, a pigment disperser, a crusher, an ultrasonic disperser, a homogenizer, a planetary mixer, a Filmix, or a planetary / revolution mixer.

[0042] (Slurry Composition for Dielectric Layer) The slurry composition for a dielectric layer of the present invention comprises the binder composition of the present invention described above, a dielectric material, and a solvent, and may optionally comprise a water-soluble polymer. The slurry composition of the present invention may further comprise components other than the copolymer, solvent, dielectric material, and water-soluble polymer (hereinafter, sometimes referred to as "other components"). When the binder composition contains a solvent, the solvent contained in the slurry composition may be entirely derived from the binder composition, or may be a solvent newly added to the slurry composition separately from the solvent derived from the binder composition. Furthermore, since the slurry composition of the present invention contains the binder composition of the present invention, it can impart excellent crack resistance and lamination properties to the dielectric layer. Furthermore, since the slurry composition of the present invention contains the binder composition of the present invention, it can impart excellent transferability to the dielectric layer.

[0043] <Dielectric Material> The dielectric material is not particularly limited as long as it is a material having dielectric properties, but it is preferable to use a ceramic material. Examples of the ceramic material include zirconia, aluminum silicate, titanium oxide, zinc oxide, barium titanate, calcium zirconate, calcium titanate, strontium titanate, magnesia, sialon, spinemullite, silicon carbide, silicon nitride, and aluminum nitride. These ceramic materials may be used alone or in combination of two or more.

[0044] Here, the ceramic material is a material having the general formula ABO ３ As the ceramic material, for example, barium titanate (BaTiO３ ), calcium zirconate (CaZrO ３ ), calcium titanate (CaTiO ３ ), strontium titanate (SrTiO ３ ), Ba that forms a perovskite structure １－ｘ－ｙ Ca ｘ Sr ｙ Ti １－ｚ Zr ｚ O ３ (0≦x≦1, 0≦y≦1, 0≦z≦1), etc. Among these, barium titanate is preferred as a ceramic material having a perovskite structure as the main phase.

[0045] The volume average particle diameter of the dielectric material is preferably 0.01 μm or more, more preferably 0.02 μm or more, even more preferably 0.05 μm or more, even more preferably 0.08 μm or more, and preferably 1 μm or less, more preferably 0.8 μm or less, even more preferably 0.5 μm or less, even more preferably 0.3 μm or less, and even more preferably 0.2 μm or less. When the volume average particle diameter of the dielectric material is within the above range, the dispersion stability of the dielectric material in the slurry composition can be improved. As a result, a dielectric layer in which the dielectric material is uniformly dispersed can be produced. In this specification, the volume average particle diameter of the dielectric material refers to the particle diameter at which the cumulative volume calculated from the smallest diameter side in the particle size distribution (volume basis) obtained by measurement using a laser diffraction method accounts for 50% of the total volume.

[0046] The content of the dielectric material in the slurry composition is preferably 40% by mass or more, more preferably 50% by mass or more, and is preferably 80% by mass or less, more preferably 70% by mass or less, when all components in the slurry composition (including the solvent) are taken as 100% by mass.

[0047] <Solvent> Examples of the solvent contained in the slurry composition of the present invention include the same solvents as those described in the section "Solvent" of the above-mentioned "Binder composition for dielectric layer". Note that, from the viewpoints of reducing the environmental load, safety, and easy availability, the solvent contained in the slurry composition of the present invention is preferably water.

[0048] <Water-soluble polymer> The water-soluble polymer that can be optionally contained in the slurry composition of the present invention is a component that can function as a viscosity modifier and a binder. The water-soluble polymer is not particularly limited, but preferably contains a structural unit having a hydroxyl group. Here, the structural unit having a hydroxyl group (hereinafter sometimes referred to as a "hydroxyl group-containing structural unit") may be a structural unit that can be formed from a monomer having a hydroxyl group (hereinafter sometimes referred to as a "hydroxyl group-containing monomer"), or may be a structural unit obtained by obtaining a polymer using a monomer composition containing a monomer having a specific functional group and then modifying or converting the functional group into a hydroxyl group.

[0049] The structure of the hydroxyl group-containing structural unit is not particularly limited as long as it is a repeating unit having a hydroxyl group. Methods for introducing the hydroxyl group-containing structural unit into a water-soluble polymer include, for example, the following methods (1) or (2): (1) A method for preparing a water-soluble polymer containing a hydroxyl group-containing structural unit from a monomer composition containing a hydroxyl group-containing monomer; (2) A method for preparing a water-soluble polymer containing a hydroxyl group-containing structural unit from a monomer composition containing a hydroxyl group-containing monomer; ２ (wherein R is any structure but is preferably an alkyl group having 1 to 19 carbon atoms), and then saponifying the polymer to convert all or part of the "R-CO-O-" of the vinyl carboxylic acid ester monomer units to hydroxyl groups, thereby preparing a water-soluble polymer containing vinyl alcohol units and, optionally, vinyl carboxylic acid ester monomer units.

[0050] Examples of the hydroxyl group-containing monomer used in the above method (1) include ethylenically unsaturated alcohols such as (meth)allyl alcohol, 3-butene-1-ol, and 5-hexene-1-ol; alkanol esters of ethylenically unsaturated carboxylic acids such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, di-2-hydroxyethyl maleate, di-4-hydroxybutyl maleate, and di-2-hydroxypropyl itaconate; and esters of ethylenically unsaturated carboxylic acids such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, di-2-hydroxyethyl maleate, di-4-hydroxybutyl maleate, and di-2-hydroxypropyl itaconate; ２ =CR １ -COO-(C ｑ H ２ｑ O) ｐ -H (wherein p is an integer of 2 to 9, q is an integer of 2 to 4, R １represents hydrogen or a methyl group) and (meth)acrylic acid esters; mono(meth)acrylic acid esters of dihydroxy esters of dicarboxylic acids such as 2-hydroxyethyl-2'-(meth)acryloyloxyphthalate and 2-hydroxyethyl-2'-(meth)acryloyloxysuccinate; vinyl ethers such as 2-hydroxyethyl vinyl ether and 2-hydroxypropyl vinyl ether; mono(meth)allyl alkylene glycols such as (meth)allyl-2-hydroxyethyl ether, (meth)allyl-2-hydroxypropyl ether, (meth)allyl-3-hydroxypropyl ether, (meth)allyl-2-hydroxybutyl ether, (meth)allyl-3-hydroxybutyl ether, (meth)allyl-4-hydroxybutyl ether, and (meth)allyl-6-hydroxyhexyl ether. ethers; polyoxyalkylene glycol mono(meth)allyl ethers such as diethylene glycol mono(meth)allyl ether and dipropylene glycol mono(meth)allyl ether; mono(meth)allyl ethers of halogen- and hydroxy-substituted (poly)alkylene glycols such as glycerin mono(meth)allyl ether, (meth)allyl-2-chloro-3-hydroxypropyl ether and (meth)allyl-2-hydroxy-3-chloropropyl ether; mono(meth)allyl ethers of polyhydric phenols such as eugenol and isoeugenol and halogen-substituted products thereof; (meth)allyl thioethers of alkylene glycols such as (meth)allyl-2-hydroxyethyl thioether and (meth)allyl-2-hydroxypropyl thioether; 2-hydroxyethyl(meth)acrylamide, N-methylolacrylamide; etc. These may be used alone or in combination of two or more.

[0051] Examples of the vinyl carboxylate monomer used in the above method (2) include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, and vinyl stearate. These can be used alone or in combination of two or more. Among these, vinyl acetate is preferred.

[0052] When preparing a water-soluble polymer by the above method (2), some of the hydroxyl groups of the obtained water-soluble polymer may be acetalized. Examples of such water-soluble polymers include polyvinyl butyral, in which the hydroxyl groups of the water-soluble polymer are acetalized with butyraldehyde. Examples of polyvinyl acetal that can be used include S-LEC BL-2H manufactured by Sekisui Chemical Co., Ltd.

[0053] The content of the water-soluble polymer is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, and is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less, based on 100 parts by mass of the dielectric material in the slurry composition.

[0054] <Other Components> Other components that can be contained in the slurry composition of the present invention include those similar to those explained in the section "Other Components" of the "Binder Composition for Dielectric Layer" above.

[0055] <Solid content concentration of slurry composition for dielectric layer> The solid content concentration of the slurry composition is preferably 20% by mass or more, more preferably 25% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less.

[0056] <Copolymer Content> The copolymer content (solid content) in the slurry composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 7 parts by mass or less, relative to 100 parts by mass of the dielectric material in the slurry composition.

[0057] <Method for preparing a slurry composition for a dielectric layer> The above-mentioned slurry composition can be prepared by mixing the above-mentioned components by a known mixing method. Examples of mixers used for the preparation include those listed in the above "Method for preparing a binder composition for a dielectric layer".

[0058] (Dielectric Layer) The dielectric layer of the present invention is formed by drying a coating film made from the above-described slurry composition of the present invention. The dielectric layer of the present invention is typically a dried film obtained by partially or completely removing the solvent from a coating film made from the slurry composition of the present invention. That is, the dielectric layer of the present invention contains the above-described copolymer and a dielectric material, and optionally contains a solvent, a water-soluble polymer, and other components. Here, since the dielectric layer of the present invention is formed by drying a coating film made from the slurry composition of the present invention, it has excellent crack resistance and lamination properties. Furthermore, since the dielectric layer of the present invention has excellent transferability, it is easy to handle, and as a result, multilayer ceramic capacitors can be produced efficiently.

[0059] The content of the dielectric material in the dielectric layer is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more, and is preferably 98% by mass or less, and more preferably 95% by mass or less, when all components in the dielectric layer are taken as 100% by mass.

[0060] The content of the copolymer in the dielectric layer is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 7 parts by mass or less, based on 100 parts by mass of the dielectric material in the dielectric layer.

[0061] When the dielectric layer contains a water-soluble polymer, the content of the water-soluble polymer in the dielectric layer is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, and is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less, based on 100 parts by mass of the dielectric material in the dielectric layer.

[0062] The thickness of the dielectric layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, and is preferably 10 μm or less, more preferably 5 μm or less.

[0063] The dielectric layer of the present invention may have a conductor layer formed on the dielectric layer. The conductor layer can be formed by various printing methods, such as screen printing, gravure printing, stamp printing, inkjet printing, and offset printing using a pattern formed by these methods, or by vacuum deposition for forming a metal vapor deposition film. When the conductor layer is formed by a printing method, a conductive paste can be used. The conductive paste can be prepared by a conventionally known method, for example, by mixing a conductive powder such as a metal, a dispersant, a plasticizer, a solvent, etc., with a polyvinyl acetal resin.

[0064] <Method of Producing Dielectric Layer> The dielectric layer can be produced by applying the slurry composition of the present invention onto a release substrate and drying the formed coating film.

[0065] Here, the release substrate used when preparing the dielectric layer is preferably made of a flexible resin. Since the release substrate is made of a flexible resin, the release substrate (laminated film) on which the dielectric layer is formed by applying a slurry composition to the release substrate and drying it can be stored in a rolled state and supplied as needed. The release substrate is not particularly limited, and examples thereof include substrates containing resins such as polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, and polyvinyl chloride.

[0066] The release substrate is preferably subjected to a surface treatment to improve releasability on the side on which the dielectric layer of the present invention is formed. The surface treatment is not particularly limited, and examples thereof include surface treatments using a release agent such as a silicone-based release agent, a fluorine-based release agent, or a wax-based release agent.

[0067] The thickness of the release substrate is not particularly limited, but is usually 20 μm or more and 100 μm or less.

[0068] The method for applying the slurry composition to the release substrate is not particularly limited, and examples thereof include known application methods using an applicator or various roll coaters such as a gravure coater and a comma coater (registered trademark).

[0069] The method for drying the coating film formed on the release substrate is not particularly limited, and for example, a known drying method using a hot air dryer can be mentioned. The drying conditions can be appropriately set depending on the content of the solvent in the coating film, the thickness of the coating film, etc., but the drying temperature is usually 80°C or higher and 150°C or lower, and the drying time is usually 3 minutes or higher and 60 minutes or lower.

[0070] When the dielectric layer of the present invention is used in the production of a multilayer ceramic capacitor or the like, a plurality of dielectric layers may be superimposed on one another and then thermocompression bonded. However, the dielectric layer may be peeled off from the release substrate either before or after the superposition and thermocompression bonding of the dielectric layers.

[0071] (Multilayer ceramic capacitor) The multilayer ceramic capacitor of the present invention is a sintered product obtained by sintering a laminate in which the dielectric layers of the present invention described above are stacked. The multilayer ceramic capacitor of the present invention has excellent performance because it uses dielectric layers that are excellent in crack resistance and lamination properties. Furthermore, the multilayer ceramic capacitor of the present invention has excellent productivity because it uses dielectric layers that are easy to handle. Note that, below, an example of the multilayer ceramic capacitor of the present invention will be described with reference to FIG. 1, but the multilayer ceramic capacitor of the present invention is not limited thereto.

[0072] FIG. 1 is a schematic cross-sectional view showing an example of a multilayer ceramic capacitor according to the present invention. The multilayer ceramic capacitor 10 shown in FIG. 1 includes layered dielectrics 11 and layered internal electrodes 12 that are alternately stacked, and a pair of external electrodes 13 on the outer sides of the dielectrics 11 and the internal electrodes 12. One of the pair of internal electrodes 12 adjacent to each other along the stacking direction, sandwiching the dielectric 11 therebetween, is electrically connected to one of the pair of external electrodes 13 within the multilayer ceramic capacitor 10, and the other of the pair of internal electrodes 12 adjacent to each other along the stacking direction, sandwiching the dielectric 11 therebetween, is electrically connected to the other of the pair of external electrodes 13 within the multilayer ceramic capacitor 10. This results in a structure in which multiple capacitor elements are electrically connected in parallel between the pair of external electrodes 13. Note that the interface between the dielectric layers of the present invention that may be formed when the dielectric layers are stacked is not shown in FIG. 1 because the dielectric layers may be integrated and disappear during sintering.

[0073] The multilayer ceramic capacitor is not particularly limited and can be produced by a conventionally known method. For example, the multilayer ceramic capacitor can be produced by stacking a plurality of dielectric layers of the present invention, each having a conductive layer that can serve as an internal electrode, so that the dielectric layers and the conductive layers alternate, heat-pressing the stack to form a laminate, thermally decomposing and removing binder components (copolymers, etc.) contained in the laminate (degreasing treatment), sintering the stack, and then forming external electrodes on the end faces of the sintered ceramic product obtained by sintering.

[0074] The degreasing treatment is usually carried out in a nitrogen atmosphere at a temperature of 300° C. to 500° C. The degreasing treatment time is usually 1 hour to 5 hours. The content of the binder component in the laminate after the degreasing treatment is usually 50 ppm or less.

[0075] The degreased laminate is usually sintered under an oxygen partial pressure of 10 －９ ~10 －１２ MPa H ２ -N ２ -H ２The sintering is carried out in a reducing atmosphere such as O gas at a temperature of 1000° C. to 1500° C. The sintering time for the laminate is usually 1 hour to 30 hours.

[0076] The external electrodes can be formed by applying an external electrode material to the end faces of the sintered ceramic product obtained by sintering and then baking the applied material. This allows, for example, a multilayer ceramic capacitor as shown in FIG. 1 to be obtained. Examples of the external electrode material include a Cu paste containing glass frit. Baking is usually performed in a nitrogen atmosphere at a temperature of 500°C or higher and 1500°C or lower. The surfaces of the external electrodes can also be plated with Ni, Sn, or the like.

[0077] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified. In addition, in a polymer produced by polymerizing multiple types of monomers, the proportion of a monomer unit formed by polymerizing a certain monomer in the polymer usually coincides with the ratio (feed ratio) of that monomer to all monomers used in the polymerization of the polymer, unless otherwise specified. In addition, the volume average particle size, glass transition temperature, crack resistance, lamination property, and transferability of the copolymer were measured and evaluated according to the following procedures.

[0078] <Method for Measuring Volume Average Particle Diameter of Copolymer> The volume average particle diameter of the copolymers in the examples and comparative examples was measured by laser diffraction. Specifically, an aqueous dispersion containing the prepared copolymer (adjusted to a solids concentration of 0.1% by mass) was used as a sample. Then, in the particle size distribution (volume basis) measured using a laser diffraction particle size distribution analyzer (manufactured by Beckman Coulter, Inc., product name "LS-230"), the particle diameter D50 at which the cumulative volume calculated from the smallest diameter side reached 50% was taken as the volume average particle diameter. Note that in Example 6, the copolymer was in a non-particulate form, so measurement of the volume average particle diameter was not performed.

[0079] <Method for Measuring Glass Transition Temperature of Copolymer> The copolymers (binder compositions) of the Examples and Comparative Examples were dried for 3 days in an environment of 50% humidity and 25°C to obtain a film having a thickness of 1.0 mm. This film was dried for 10 hours in a vacuum dryer at 60°C. Thereafter, the glass transition temperature (°C) of the dried film was measured as a sample in accordance with JIS K7121 using a DSC6220SII (differential scanning calorimeter, manufactured by Nano Technology Corporation) at a measurement temperature of -100°C to 180°C and a heating rate of 5°C / min.

[0080] <Crack Resistance> In the Examples and Comparative Examples, the dielectric layer formed on the release substrate (release substrate with dielectric layer) was cut into a square with a width of 5 cm and a length of 5 cm, and the release substrate was peeled off to obtain a test piece. Two such test pieces were prepared, stacked on top of each other, and then subjected to a temperature of 80°C and 5 kg / cm ２ The dielectric layer was visually inspected and evaluated for crack resistance according to the following criteria: A: No cracks occurred at both 1000°C and 1200°C B: No cracks occurred at 1000°C, but cracks occurred at 1200°C C: Cracks occurred at both 1000°C and 1200°C

[0081] <Lamination Properties> The release substrate with a dielectric layer (release substrate with a dielectric layer) produced in the Examples and Comparative Examples was cut into a square with a width of 5 cm and a length of 5 cm, and the release substrate was peeled off to obtain a test piece. Two such test pieces were prepared, stacked on top of each other, and then subjected to a heating treatment at 80°C and 5 kg / cm ２ The laminated dielectric layers were then cut with a cutter, and the cross sections of the laminated dielectric layers were visually inspected and evaluated according to the following criteria: A: The dielectric layers were bonded together, and no powder had fallen off the cut surface; B: The dielectric layers were bonded together, but powder had fallen off the cut surface; C: The dielectric layers were not bonded together, and powder had fallen off the cut surface.

[0082] <Transferability> The release substrates with a dielectric layer produced in the Examples and Comparative Examples were cut into squares measuring 5 cm in width and 5 cm in length to prepare test pieces. Two of the test pieces were prepared, and the test pieces were stacked on top of each other with the dielectric layers facing each other. The test pieces were then heated at 40°C and 5 kg / cm ２The test pieces were pressed for 10 seconds under a pressure of 0.05 W. Thereafter, the release substrate of one of the test pieces was peeled off, and the peeling state (transferability) of the dielectric layer was visually confirmed, and the transferability was evaluated according to the following criteria. A: The dielectric layers maintained their adhesion state, and no dielectric layer remained on the surface of the peeled release substrate. B: The dielectric layers maintained their adhesion state, but some of the dielectric layer remained on the surface of the peeled release substrate. C: The dielectric layers did not adhere to each other, and most of the dielectric layer remained on the surface of the release substrate.

[0083] Example 1 Preparation of Aqueous Dispersion of Copolymer (Binder Composition) 74 parts of ion-exchanged water, 0.2 parts of sodium dodecyl diphenyl ether sulfonate, and 1.0 parts of ammonium persulfate as a polymerization initiator were added to a polymerization vessel A, heated to 70°C, and stirred for 30 minutes. Next, a separate polymerization vessel B was added to the same vessel as above, containing 78.0 parts of 2-ethylhexyl acrylate as a (meth)acrylic acid ester monomer, 20.0 parts of acrylonitrile as a cyano group-containing monomer, 2.0 parts of itaconic acid as an additional monomer (acid group-containing monomer), 0.8 parts of sodium dodecyl diphenyl ether sulfonate as an emulsifier, and 74 parts of ion-exchanged water, followed by stirring to prepare an emulsion. The prepared emulsion was gradually added from polymerization vessel B to polymerization vessel A over approximately 200 minutes, and the resulting mixture was stirred for approximately 180 minutes. When the monomer conversion reached 97% or higher, the mixture was cooled to terminate the reaction. The pH was then adjusted with a 4% aqueous sodium hydroxide solution, and unreacted monomers were removed by heating under reduced pressure to obtain an aqueous dispersion of the copolymer (binder composition). The pH of the resulting aqueous dispersion was 8.0. The glass transition temperature and volume average particle size of the copolymer were measured using the resulting aqueous dispersion. The results are shown in Table 1.

[0084] <Preparation of Slurry Composition> 100 parts of barium titanate (manufactured by Sakai Chemical Industry Co., Ltd., "BT-01") having a volume average particle diameter (d50) of 0.1 μm as the dielectric material, 5 parts in solids of polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., S-LEC BL-2H) as the water-soluble polymer, and 20 parts of water as the solvent were mixed with 100 parts of zirconia beads (manufactured by Nikkato Corporation) having a particle diameter of 0.1 mm as mixing beads using a bead mill (manufactured by Imex Co., Ltd., "RMB-01") at 500 rpm for 2 hours. Then, 20 parts of water were added, and the mixture was stirred at 500 rpm for 1 hour. The zirconia beads were filtered off to prepare a dispersion of barium titanate. To 152.5 parts of this dispersion (100 parts of barium titanate content), 5 parts of the copolymer obtained above (12.5 parts as aqueous dispersion) was added, and then the mixture was stirred at 1000 rpm for 3 minutes using a planetary centrifugal mixer to prepare a slurry composition.

[0085] <Preparation of Dielectric Layer> The slurry composition obtained above was applied to a release-treated film (PET38AL-5, manufactured by Lintec Corporation) measuring 100 mm wide x 100 mm long using a gravure coater so that the film thickness of the dielectric layer after drying would be approximately 1.0 μm, and the film was dried in an oven at 100°C for 5 minutes to obtain a dielectric layer on the release substrate (ceramic green sheet method). The resulting release substrate with the dielectric layer was used to evaluate crack resistance, lamination property, and transferability. The results are shown in Table 1.

[0086] (Example 2) In preparing the aqueous dispersion of the copolymer, the amount of 2-ethylhexyl acrylate was changed from 78.0 parts to 86.0 parts, and the amount of acrylonitrile was changed from 20.0 parts to 12.0 parts, except that the procedures, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0087] (Example 3) In preparing the aqueous dispersion of the copolymer, the amount of 2-ethylhexyl acrylate was changed from 78.0 parts to 70.0 parts, and the amount of acrylonitrile was changed from 20.0 parts to 28.0 parts, except that the procedures, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0088] Example 4 Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in preparing the aqueous dispersion of the copolymer, the amount of sodium dodecyl diphenyl ether sulfonate added to polymerization vessel A was changed from 0.2 parts to 0.8 parts, and the amount of sodium dodecyl diphenyl ether sulfonate added to polymerization vessel B was changed from 0.8 parts to 1.0 part. The results are shown in Table 1.

[0089] Example 5 Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in preparing an aqueous dispersion of the copolymer, sodium dodecyl diphenyl ether sulfonate was not added to polymerization vessel A, and the amount of sodium dodecyl diphenyl ether sulfonate added to polymerization vessel B was changed from 0.8 parts to 0.5 parts. The results are shown in Table 1.

[0090] (Example 6) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that an aqueous solution of the copolymer obtained by the following procedure was used as the aqueous dispersion of the copolymer. The results are shown in Table 1.

[0091] <Preparation of Aqueous Solution of Copolymer (Binder Composition)> A 1 L four-neck flask equipped with a reflux condenser, a thermometer, an air inlet tube, and a stirrer was charged with 78.0 parts of 2-ethylhexyl acrylate as a (meth)acrylic acid ester monomer, 20.0 parts of acrylonitrile as a cyano group-containing monomer, 2.0 parts of itaconic acid as an additional monomer (acid group-containing monomer), and 100 parts of water, and mixed to prepare a mixture. While stirring this mixture, 2 parts of benzoyl peroxide as a polymerization initiator was added. While further stirring, the mixture was heated to 80°C. After the temperature of the mixture reached 80°C, it was stirred at 80°C for an additional 5 hours. Subsequently, the temperature inside the flask was allowed to cool to room temperature, and then 10 parts of diethanolamine as an amine component was slowly added for neutralization. This yielded an aqueous solution of the copolymer (binder composition).

[0092] (Example 7) In preparing the aqueous dispersion of the copolymer, various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that 2-ethylhexyl acrylate was changed to ethyl acrylate. The results are shown in Table 1.

[0093] (Example 8) In preparing the aqueous dispersion of the copolymer, the amount of 2-ethylhexyl acrylate was changed from 78.0 parts to 80.0 parts, and itaconic acid was not added, and other than this, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0094] Comparative Example 1 Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in the preparation of the aqueous dispersion of the copolymer, the amount of 2-ethylhexyl acrylate was changed from 78.0 parts to 90.0 parts and the amount of acrylonitrile was changed from 20.0 parts to 8.0 parts. The results are shown in Table 1.

[0095] Comparative Example 2 In preparing the aqueous dispersion of the copolymer, the amount of 2-ethylhexyl acrylate was changed from 78.0 parts to 48.0 parts, and the amount of acrylonitrile was changed from 20.0 parts to 50.0 parts, except that the procedures, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0096] In Table 1, "AN" represents an acrylonitrile unit, "2-EHA" represents a 2-ethylhexyl acrylate unit, "EA" represents an ethyl acrylate unit, and "IA" represents an itaconic acid unit.

[0097]

[0098] As is clear from Table 1, the binder compositions for dielectric layers of the examples can impart excellent crack resistance and lamination properties to the dielectric layer.

[0099] According to the present invention, a binder composition for a dielectric layer can be provided that can impart excellent crack resistance and lamination properties to a dielectric layer. Furthermore, according to the present invention, a slurry composition for a dielectric layer can be provided that can impart excellent crack resistance and lamination properties to a dielectric layer. Furthermore, according to the present invention, a dielectric layer that is excellent in crack resistance and lamination properties can be provided. Furthermore, according to the present invention, a multilayer ceramic capacitor can be provided by sintering a laminate in which the above-mentioned dielectric layers are stacked.

[0100] 10: Multilayer ceramic capacitor 11: Dielectric 12: Internal electrode 13: External electrode

Claims

1. A binder composition for a dielectric layer, comprising a copolymer containing a cyano group-containing monomer unit and a (meth)acrylic acid ester monomer unit, wherein the content of the cyano group-containing monomer unit is 10% by mass or more and 45% by mass or less, when the total amount of all repeating units contained in the copolymer is taken as 100% by mass.

2. The binder composition for a dielectric layer according to claim 1, wherein the glass transition temperature of the copolymer is from -50°C to 50°C.

3. The binder composition for a dielectric layer according to claim 1, wherein the copolymer is a particulate copolymer.

4. The binder composition for a dielectric layer according to claim 3, wherein the particulate copolymer has a volume average particle size of 0.01 μm or more and 0.5 μm or less.

5. A binder composition for a dielectric layer as described in claim 1, wherein the content of the (meth)acrylic acid ester monomer unit is 55% by mass or more and 90% by mass or less, when the total amount of all repeating units contained in the copolymer is 100% by mass.

6. A slurry composition for a dielectric layer, comprising the binder composition for a dielectric layer according to any one of claims 1 to 5, a dielectric material, and a solvent.

7. The dielectric layer slurry composition according to claim 6, wherein said solvent is water.

8. A dielectric layer formed by drying a coating film made of the slurry composition for a dielectric layer according to claim 6.

9. A multilayer ceramic capacitor obtained by sintering a laminate in which the dielectric layers according to claim 8 are stacked together.

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