Slurry composition for dielectric layers, dielectric layer, multilayer body for multilayer ceramic capacitors and method for producing same, and multilayer ceramic capacitor

Abstract

The purpose of the present invention is to provide a slurry composition for dielectric layers, which is capable of imparting excellent wettability to a dielectric layer. The present invention provides a slurry composition for dielectric layers, the slurry composition containing a dielectric material that has a perovskite structure, a water-soluble polymer, a defoaming agent, and water. The defoaming agent content is 0.001 part by mass to 1 part by mass inclusive if the dielectric material content is taken as 100 parts by mass.

Description

Slurry composition for dielectric layer, dielectric layer, laminate for multilayer ceramic capacitor and method for producing the same, and multilayer ceramic capacitor

[0001] The present invention relates to a slurry composition for a dielectric layer, a dielectric layer, a laminate for a multilayer ceramic capacitor and a method for producing the same, 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 or the like, and then drying. Internal electrode layers are then formed on the resulting dielectric layers, and the resulting layers are laminated together. An optional degreasing treatment (binder removal treatment) is then performed, followed by sintering, to obtain a multilayer ceramic capacitor.

[0003] In recent years, in order to impart excellent characteristics to capacitors, development of slurry compositions used in the production of dielectric layers has been progressing. For example, Patent Document 1 proposes a slurry composition that can produce ceramic green sheets with little binder residue during binder removal treatment and excellent smoothness and ceramic particle density after binder removal treatment, the slurry composition containing a dispersion medium made of an organic solvent, ceramic powder having a predetermined average particle size, and a binder made of a predetermined (meth)acrylate copolymer.

[0004] Patent No. 6337628

[0005] Here, the internal electrode layers can be formed on the dielectric layers by applying a conductive paste, and from the viewpoint of achieving good adhesion between the dielectric layers and the internal electrode layers and imparting excellent performance to the resulting multilayer ceramic capacitor, it is desirable that the dielectric layers have excellent wettability to the conductive paste (hereinafter, sometimes simply referred to as "wettability").

[0006] Therefore, an object of the present invention is to provide a slurry composition for a dielectric layer that can impart excellent wettability to a dielectric layer. Another object of the present invention is to provide a dielectric layer that has excellent wettability. Another object of the present invention is to provide a laminate for a multilayer ceramic capacitor that can impart excellent performance to a multilayer ceramic capacitor, and a method for producing the same. Another object of the present invention is to provide a multilayer ceramic capacitor with excellent performance.

[0007] 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 slurry composition for a dielectric layer containing a dielectric material having a perovskite structure, a water-soluble polymer, a predetermined amount of an antifoaming agent, and water, and have completed the present invention based on this discovery.

[0008]

[0010] The present invention aims to advantageously solve the above-mentioned problems, and provides a slurry composition for a dielectric layer, comprising a dielectric material having a perovskite structure, a water-soluble polymer, an antifoaming agent, and water, wherein the content of the antifoaming agent is 0.001 part by mass or more and 1 part by mass or less, relative to 100 parts by mass of the dielectric material. The above-described slurry composition for a dielectric layer can impart excellent wettability to the dielectric layer.

[0009] [2] In the dielectric layer slurry composition of [1] above, the weight-average molecular weight of the water-soluble polymer is preferably 100,000 or more and 2,000,000 or less. If the weight-average molecular weight of the water-soluble polymer is equal to or more than the lower limit, the drying speed of the dielectric layer slurry composition can be improved. On the other hand, if the weight-average molecular weight of the water-soluble polymer is equal to or less than the upper limit, the wettability of the resulting dielectric layer can be improved. In this specification, the "weight-average molecular weight" of a polymer can be measured using the method described in the examples of this specification.

[0010] [3] In the dielectric layer slurry composition of [1] or [2] above, the defoaming agent is preferably at least one of a silicone-based defoaming agent and a nonionic surfactant. When the defoaming agent is at least one of a silicone-based defoaming agent and a nonionic surfactant, the wettability of the resulting dielectric layer can be improved. Furthermore, the coating density of the film obtained using the dielectric layer slurry composition can be improved.

[0011] [4] In the slurry composition for a dielectric layer according to any one of the above [1] to [3], the water-soluble polymer preferably contains a structural unit having a hydrophilic group, and the hydrophilic group is at least one of a carboxylic acid group and a hydroxyl group. When the water-soluble polymer contains a structural unit having a hydrophilic group, and the hydrophilic group is at least one of a carboxylic acid group and a hydroxyl group, the wettability of the resulting dielectric layer can be further improved.

[0012] [5] In the dielectric layer slurry composition according to any one of [1] to [4] above, the content of the water-soluble polymer is preferably 0.1 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the dielectric material. When the content of the water-soluble polymer is equal to or more than the lower limit, the wettability of the resulting dielectric layer can be improved. On the other hand, when the content of the water-soluble polymer is equal to or less than the upper limit, the drying speed of the dielectric layer slurry composition can be improved. Furthermore, the coating density of the resulting film can be improved.

[0013] [6] In the dielectric layer slurry composition according to any one of [1] to [5] above, the mass ratio of the antifoaming agent to the water-soluble polymer is preferably 0.001 or more and 0.1 or less. When the mass ratio of the antifoaming agent to the water-soluble polymer is equal to or more than the lower limit, the wettability of the resulting dielectric layer can be improved. On the other hand, when the mass ratio of the antifoaming agent to the water-soluble polymer is equal to or less than the upper limit, the drying speed of the dielectric layer slurry composition can be improved.

[0014] [7] The dielectric layer slurry composition according to any one of [1] to [6] above preferably further contains a particulate polymer. If the dielectric layer slurry composition further contains a particulate polymer, the coating density of the resulting film can be improved.

[0015] Another object of the present invention is to advantageously solve the above-mentioned problems, and [8] the present invention is a dielectric layer obtained by drying a coating film made of a slurry composition for a dielectric layer according to any one of [1] to [7] above. The dielectric layer as described above has excellent wettability.

[0016] Another object of the present invention is to advantageously solve the above-mentioned problems, and [9] the present invention is a laminate for a multilayer ceramic capacitor, comprising the dielectric layer of [8] above and internal electrode layers provided on the surfaces of the dielectric layers, the internal electrode layers containing a conductive material and a binder. The laminate for a multilayer ceramic capacitor as described above can impart excellent performance to the multilayer ceramic capacitor.

[0017] The present invention also aims to advantageously solve the above-mentioned problems, and provides, in

[10] a method for producing a laminate for a multilayer ceramic capacitor, comprising a dielectric layer and an internal electrode layer provided on the surface of the dielectric layer, the method comprising: a dielectric layer forming step of applying a slurry composition for a dielectric layer according to any one of [1] to [7] above onto a release substrate and drying the coating film to form a dielectric layer; and an internal electrode layer forming step of applying a conductive paste containing a conductive material, a binder, and an organic solvent onto the dielectric layer and drying the coating film to form an internal electrode layer. The above-mentioned production method makes it possible to obtain a laminate for a multilayer ceramic capacitor that can impart excellent performance to the multilayer ceramic capacitor.

[0018]

[11] In the method for producing a laminate for a multilayer ceramic capacitor according to the above

[10] , the organic solvent is preferably a terpene-based solvent. If the organic solvent is a terpene-based solvent, the drying speed can be increased.

[0019]

[12] In the method for manufacturing a laminate for a multilayer ceramic capacitor according to the above

[10] or

[11] , the conductive material is preferably a powder of Ni or a Ni alloy. If the conductive material is a powder of Ni or a Ni alloy, the conductivity and corrosion resistance of the internal electrode layers can be improved. In addition, the cost of the internal electrode layers can be reduced.

[0020] Another object of the present invention is to advantageously solve the above-mentioned problems, and the present invention

[13] provides a multilayer ceramic capacitor obtained by sintering the laminate for a multilayer ceramic capacitor according to the above [9]. The multilayer ceramic capacitor as described above has excellent performance.

[0021] According to the present invention, it is possible to provide a slurry composition for a dielectric layer that can impart excellent wettability to a dielectric layer. Further, according to the present invention, it is possible to provide a dielectric layer that has excellent wettability. Further, according to the present invention, it is possible to provide a laminate for a multilayer ceramic capacitor that can impart excellent performance to a multilayer ceramic capacitor, and a method for producing the same. Further, according to the present invention, it is possible to provide a multilayer ceramic capacitor that has excellent performance.

[0022] 1 is a schematic cross-sectional view showing an example of a multilayer ceramic capacitor of the present invention.

[0023] Hereinafter, embodiments of the present invention will be described in detail. Herein, the slurry composition for dielectric layer of the present invention (hereinafter sometimes simply referred to as "slurry composition") can be used to form a dielectric layer used in manufacturing a multilayer ceramic capacitor. The dielectric layer of the present invention can be formed by drying a coating film made of the slurry composition of the present invention. The laminate for multilayer ceramic capacitor of the present invention (hereinafter sometimes simply referred to as "laminate") includes the dielectric layer of the present invention and can be used to manufacture a multilayer ceramic capacitor. The multilayer ceramic capacitor of the present invention can be obtained by sintering the laminate of the present invention.

[0024] (Slurry Composition for Dielectric Layer) The slurry composition for a dielectric layer of the present invention comprises a dielectric material having a perovskite structure (hereinafter sometimes simply referred to as the "dielectric material"), a water-soluble polymer, an antifoaming agent, and water, and may optionally comprise a particulate polymer. Furthermore, in the slurry composition of the present invention, the content of the antifoaming agent is 0.001 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the dielectric material. Such a slurry composition can impart excellent wettability to the dielectric layer. While the use of a water-soluble polymer in the slurry composition can improve the wettability of the dielectric layer, it can also easily cause the slurry composition to foam, which can inhibit the improvement of the wettability of the dielectric layer. The slurry composition of the present invention effectively suppresses foaming of the slurry composition by using a predetermined amount of antifoaming agent, thereby imparting excellent wettability to the dielectric layer. Furthermore, the slurry composition as described above has an excellent drying speed because the content of the antifoaming agent is within a predetermined range. Furthermore, since the above-described slurry composition is inhibited from foaming, pinholes in the film obtained using the slurry composition can be effectively suppressed, thereby increasing the coating density and increasing the relative dielectric constant of the dielectric layer.

[0025] The slurry composition of the present invention may optionally further contain a component other than the dielectric material, the water-soluble polymer, water, and the particulate polymer (hereinafter, sometimes referred to as "other component A").

[0026] In the slurry composition of the present invention, the dielectric material has a perovskite structure. Here, the "perovskite structure" is defined as a structure having the general formula ABO ３ The term "dielectric material having a perovskite structure" means a structure represented by the general formula ABO in at least a part of the dielectric material. ３ It means that there is a structure represented by the following formula: The slurry composition may optionally further contain a dielectric material other than the dielectric material having a perovskite structure.

[0027] The dielectric material is not particularly limited as long as it has a perovskite structure, but a ceramic material having a perovskite structure as the main phase is preferred. Examples of such ceramic materials include barium titanate (BaTiO ３ ), 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 and calcium zirconate are preferred as ceramic materials having a perovskite structure as the main phase.

[0028] 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 becomes 50% in the particle size distribution (volume basis) obtained by measurement using a laser diffraction method.

[0029] 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.

[0030] <Water-Soluble Polymer> In the slurry composition of the present invention, the water-soluble polymer is a component that can function as a viscosity modifier and a binder.

[0031] Here, the water-soluble polymer is not particularly limited, but preferably contains a structural unit having a hydrophilic group (hereinafter, sometimes referred to as a "hydrophilic group-containing structural unit"), because this can improve the wettability of the resulting dielectric layer. Examples of hydrophilic groups include acid groups such as carboxylic acid groups, sulfonic acid groups, and phosphate groups; hydroxyl groups; and amide groups. Among these, the hydrophilic group is preferably at least one of an acid group and a hydroxyl group, more preferably at least one of a carboxylic acid group and a hydroxyl group, and even more preferably a carboxylic acid group, because this can further improve the wettability of the resulting dielectric layer. The water-soluble polymer may contain a (meth)acrylic acid alkyl ester monomer unit in addition to the hydrophilic group-containing structural unit. The water-soluble polymer may also contain a monomer unit other than the hydrophilic group-containing structural unit and the (meth)acrylic acid alkyl ester monomer unit (hereinafter, sometimes referred to as "other monomer unit A"). In this specification, "(meth)acrylic" refers to acrylic and / or methacrylic.

[0032] <<Structural Unit Having Hydrophilic Group>> The structural unit having a hydrophilic group (hydrophilic group-containing structural unit) may be a structural unit that can be formed from a monomer having a hydrophilic group (hereinafter, may be referred to as a “hydrophilic group-containing monomer”), or may be a structural unit obtained by obtaining a water-soluble polymer using a monomer composition containing a monomer having a predetermined functional group, and then modifying or converting the functional group into a hydrophilic group.

[0033] Carboxylic acid group-containing monomers capable of forming structural units having a carboxylic acid group as a hydrophilic group (hereinafter sometimes referred to as "carboxylic acid group-containing structural units") 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, α-chloro-β-E-methoxyacrylic acid, and β-diaminoacrylic 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 esters such as methylallyl maleate, diphenyl maleate, nonyl maleate, decyl maleate, dodecyl maleate, octadecyl maleate, and fluoroalkyl maleates. Examples of dicarboxylic acid anhydrides include maleic anhydride, acrylic anhydride, methyl maleic anhydride, and dimethyl maleic anhydride. Furthermore, acid anhydrides that generate carboxylic acid groups upon hydrolysis can also be used as carboxylic acid group-containing monomers. Other examples include monoesters and diesters of α,β-ethylenically unsaturated polycarboxylic acids, such as monoethyl maleate, diethyl maleate, monobutyl maleate, dibutyl maleate, monoethyl fumarate, diethyl fumarate, monobutyl fumarate, dibutyl fumarate, monocyclohexyl fumarate, dicyclohexyl fumarate, monoethyl itaconate, diethyl itaconate, monobutyl itaconate, and dibutyl itaconate. Among the above, acrylic acid and methacrylic acid are preferred as carboxylic acid group-containing monomers.

[0034] Examples of sulfonic acid group-containing monomers capable of forming structural units having a sulfonic acid group as a hydrophilic group (hereinafter sometimes referred to as "sulfonic acid group-containing structural units") include vinyl sulfonic acid, methyl vinyl sulfonic acid, (meth)allyl sulfonic acid, styrene sulfonic acid, (meth)acrylic acid-2-ethyl sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, and 3-allyloxy-2-hydroxypropanesulfonic acid. Of these, vinyl sulfonic acid is preferred. In this specification, "(meth)allyl" means allyl and / or methallyl.

[0035] Examples of phosphate group-containing monomers capable of forming structural units having a phosphate group as a hydrophilic group (hereinafter sometimes referred to as "phosphate group-containing structural units") include 2-(meth)acryloyloxyethyl phosphate, methyl-2-(meth)acryloyloxyethyl phosphate, ethyl-(meth)acryloyloxyethyl phosphate, vinylphosphonic acid, dimethyl vinylphosphonate, etc. In this specification, "(meth)acryloyl" means acryloyl and / or methacryloyl.

[0036] Examples of amide group-containing monomers that can form structural units having amide groups as hydrophilic groups (hereinafter, sometimes referred to as "amide group-containing structural units") include acrylamide and methacrylamide.

[0037] The structure of a structural unit having a hydroxyl group as a hydrophilic group (hereinafter, sometimes referred to as a "hydroxyl group-containing structural unit") is not particularly limited as long as it is a repeating unit having a hydroxyl group. Methods for introducing a 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 represented by the general formula: R-CO-O-CH=CH ２(wherein R is any structure, but is preferably an alkyl group having 1 to 19 carbon atoms), to prepare a polymer from a monomer composition containing the vinyl carboxylic acid ester monomer represented by the formula:

[0038] 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-hydroxyethyl methacrylate), 2-hydroxypropyl methacrylate, di-2-hydroxyethyl maleate, di-4-hydroxybutyl maleate, and di-2-hydroxypropyl itaconate; and compounds of the general formula: CH 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. Among these, alkanol esters of ethylenically unsaturated carboxylic acids are preferred, and 2-hydroxyethyl methacrylate (2-hydroxyethyl methacrylate) is more preferred.

[0039] 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.

[0040] 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.

[0041] The content of the hydrophilic group-containing structural unit in the water-soluble polymer is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 50% by mass or less, and even more preferably 40% by mass or less, when the total of all repeating units (total monomer units and all structural units) contained in the water-soluble polymer is taken as 100% by mass. If the content of the hydrophilic group-containing structural unit is equal to or greater than the lower limit above, the wettability of the resulting dielectric layer can be improved. On the other hand, if the content of the hydrophilic group-containing structural unit is equal to or less than the upper limit above, the drying speed of the slurry composition can be improved. In this specification, the content of various repeating units (monomer units and structural units) in the polymer is １ It can be measured using a nuclear magnetic resonance (NMR) method such as H-NMR.

[0042] <<(Meth)acrylic acid alkyl ester monomer unit>> The (meth)acrylic acid alkyl ester monomer unit that the water-soluble polymer may contain is a monomer unit that may be formed from a (meth)acrylic acid alkyl ester monomer.

[0043] Examples of (meth)acrylic acid alkyl ester monomers that can form (meth)acrylic acid alkyl ester monomer units include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, isopentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, n-tetradecyl acrylate, and stearyl acrylate. and alkyl methacrylate esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, n-tetradecyl methacrylate, and stearyl methacrylate. These may be used alone or in combination of two or more. Among these, ethyl acrylate and n-butyl acrylate are preferred. That is, it is preferable that the water-soluble polymer contains at least one of ethyl acrylate units and n-butyl acrylate units. It is more preferable that the water-soluble polymer contains ethyl acrylate units and n-butyl acrylate units.

[0044] The content of the (meth)acrylic acid alkyl ester monomer unit in the water-soluble polymer is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 50% by mass or more, even more preferably 60% by mass or more, and is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, and even more preferably 70% by mass or less, when all repeating units (all monomer units and all structural units) contained in the water-soluble polymer are taken as 100% by mass.

[0045] <<Other Monomer Units A>> The other monomer units A are monomer units that can be formed by other monomers A. The other monomers A are not particularly limited as long as they are monomers that can be copolymerized with the above-described monomers that can form the water-soluble polymer. Examples of the other monomer A include crosslinkable monomers (crosslinkable monomers) such as polyfunctional ethylenically unsaturated carboxylic acid ester monomers having two or more ethylenically unsaturated bonds (C=C) in the molecule, such as allyl glycidyl ether, allyl (meth)acrylate, and ethoxylated pentaerythritol tetraacrylate; olefins such as ethylene and propylene; halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether; vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone, and isopropenyl vinyl ketone; heterocycle-containing vinyl compounds such as N-vinylpyrrolidone, vinylpyridine, and vinylimidazole; and amino group-containing monomers such as aminoethyl vinyl ether and dimethylaminoethyl vinyl ether. These other monomers A may be used alone or in combination of two or more.

[0046] The content of the other monomer units A in the water-soluble polymer is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and even more preferably 0% by mass, i.e., the water-soluble polymer does not contain any other monomer units A, when all repeating units (all monomer units and all structural units) contained in the water-soluble polymer are taken as 100% by mass.

[0047] <<Characteristics of Water-Soluble Polymer>> The water-soluble polymer preferably has a weight-average molecular weight of 100,000 or more, more preferably 200,000 or more, and preferably 2,000,000 or less, more preferably 1,500,000 or less. If the weight-average molecular weight of the water-soluble polymer is equal to or greater than the lower limit, the drying speed of the slurry composition can be improved. On the other hand, if the weight-average molecular weight of the water-soluble polymer is equal to or less than the upper limit, the wettability of the resulting dielectric layer can be improved.

[0048] The water-soluble polymer preferably has a glass transition temperature of 0° C. or higher, more preferably 5° C. or higher, and preferably 100° C. or lower, more preferably 80° C. or lower. In this specification, the glass transition temperature of the polymer can be measured according to the method described in the examples.

[0049] <<Water-soluble polymer content>> The content of the water-soluble polymer in the slurry composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, based on 100 parts by mass of the dielectric material. If the content of the water-soluble polymer is equal to or greater than the lower limit, the wettability of the resulting dielectric layer can be improved. On the other hand, if the content of the water-soluble polymer is equal to or less than the upper limit, the drying speed of the slurry composition for the dielectric layer can be improved. Furthermore, the coating density of the resulting film can be improved.

[0050] <<Method for Preparing Water-Soluble Polymers>> Water-soluble polymers can be obtained, for example, by polymerizing a monomer composition obtained by mixing the above-mentioned monomers with an arbitrary polymerization solvent using an arbitrary polymerization method, and optionally performing a treatment such as saponification. The polymerization method for the water-soluble polymer is not limited, and may be, for example, a solution polymerization method such as aqueous solution polymerization, a slurry polymerization method, a suspension polymerization method, a bulk polymerization method, or an emulsion polymerization method. The polymerization reaction may be addition polymerization such as ionic polymerization, radical polymerization, or living radical polymerization. Commonly used additives, such as polymerization initiators, polymerization promoters, emulsifiers, dispersants, and chain transfer agents, may be used in the polymerization, and the amounts used may be the same as commonly used amounts. Among these, aqueous solution polymerization using water as the polymerization solvent is preferred because it does not require a solvent removal operation and the solvent is highly safe.

[0051] In addition, when water is used as a polymerization solvent and the above-mentioned monomer composition is polymerized in water to prepare an aqueous solution containing a water-soluble polymer, it is preferable to adjust the pH of the aqueous solution to 7 or more and 9 or less after the polymerization.

[0052] Here, the polymerization initiator that can be used in preparing the water-soluble polymer is not particularly limited, and includes known polymerization initiators such as sodium persulfate, ammonium persulfate, and potassium persulfate. Among them, potassium persulfate is preferably used. The polymerization initiator may be used alone or in combination of two or more types in any ratio.

[0053] The polymerization accelerator is not particularly limited, and a known reducing polymerization accelerator, such as tetramethylethylenediamine, can be used. The polymerization accelerator may be used alone or in combination of two or more in any ratio.

[0054] <Antifoaming Agent> The antifoaming agent is a component that can suppress foaming of the slurry composition of the present invention.

[0055] Here, the defoaming agent is not particularly limited as long as it is a compound that exhibits defoaming properties. Examples include mineral oil-based defoaming agents such as modified hydrocarbon oils based on mineral oil; silicone-based defoaming agents such as silicone oil; and nonionic surfactants such as acetylene glycol-based surfactants. These may be used alone or in combination of two or more in any ratio. The defoaming agent is preferably at least one of a silicone-based defoaming agent and a nonionic surfactant, as this can improve the wettability of the resulting dielectric layer and the coating density of the resulting film. Furthermore, the defoaming agent is more preferably a silicone-based defoaming agent, and even more preferably silicone oil, as this can further improve the coating density of the resulting film.

[0056] The content of the antifoaming agent in the slurry composition must be 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and must be 1 part by mass or less, preferably 0.1 parts by mass or less, based on 100 parts by mass of the dielectric material. If the content of the antifoaming agent is equal to or greater than the lower limit, the wettability of the resulting dielectric layer can be improved. On the other hand, if the content of the antifoaming agent is equal to or less than the upper limit, the drying speed of the slurry composition can be improved.

[0057] In the slurry composition, the mass ratio of the antifoaming agent to the water-soluble polymer (antifoaming agent / water-soluble polymer) is preferably 0.001 or more, more preferably 0.01 or more, and preferably 0.1 or less, more preferably 0.08 or less. When the mass ratio of the antifoaming agent to the water-soluble polymer is equal to or greater than the lower limit, the wettability of the resulting dielectric layer can be improved. On the other hand, when the mass ratio of the antifoaming agent to the water-soluble polymer is equal to or less than the upper limit, the drying speed of the slurry composition can be improved.

[0058] <Particulate Polymer> The slurry composition of the present invention further preferably contains a particulate polymer. If the slurry composition further contains a particulate polymer, the coating density of the obtained film can be improved.

[0059] Here, the particulate polymer is a component that can function as a binder, imparting adhesiveness to the dielectric layer formed using the slurry composition and also retaining materials (e.g., dielectric materials) contained in the dielectric layer so that they do not detach from the dielectric layer. Note that the particulate polymer has a particulate shape in the slurry composition, but may exist in the dielectric layer while maintaining the particulate shape or may exist in any non-particulate shape.

[0060] The particulate polymer is preferably water-insoluble. In this specification, the term "water-insoluble" means that when 0.5 g of the polymer is dissolved in 100 g of water at 25° C., the insoluble content is 90 mass % or more.

[0061] The particulate polymer is not particularly limited, and any polymer such as a conjugated diene polymer or an acrylic polymer can be used.

[0062] <<Conjugated Diene Polymer>> A conjugated diene polymer is a polymer containing a conjugated diene monomer unit. The conjugated diene polymer may optionally contain an aromatic vinyl monomer unit, a hydrophilic group-containing structural unit, and a cyano group-containing monomer unit. Furthermore, the conjugated diene polymer may contain a monomer unit other than the conjugated diene monomer unit, the aromatic vinyl monomer unit, the hydrophilic group-containing structural unit, and the cyano group-containing monomer unit (hereinafter, sometimes referred to as "other monomer unit B").

[0063] Examples of the conjugated diene polymer include copolymers containing aromatic vinyl monomer units and conjugated diene monomer units, such as styrene-butadiene copolymer (SBR), butadiene rubber (BR), isoprene rubber, acrylic rubber (NBR) (copolymers containing cyano group-containing monomer units and conjugated diene monomer units), and hydrogenated products thereof.

[0064] [Conjugated Diene Monomer Unit] The conjugated diene monomer unit is a monomer unit that can be formed by a conjugated diene monomer. Examples of conjugated diene monomers include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, substituted linear conjugated pentadienes, and substituted and side-chain conjugated hexadienes. These may be used alone or in combination of two or more. Among these, 1,3-butadiene and 2-methyl-1,3-butadiene (isoprene) are preferred as the conjugated diene monomer, with 1,3-butadiene being more preferred.

[0065] The content of conjugated diene monomer units in the conjugated diene polymer is preferably 20% by mass or more, more preferably 25% by mass or more, and is preferably 60% by mass or less, more preferably 55% by mass or less, when all repeating units (all monomer units and all structural units) contained in the conjugated diene polymer are taken as 100% by mass.

[0066] [Aromatic vinyl monomer unit] The aromatic vinyl monomer unit is a monomer unit that can be formed by an aromatic vinyl monomer. Examples of aromatic vinyl monomers include styrene, α-methylstyrene, vinyltoluene, and divinylbenzene. These may be used alone or in combination of two or more. Among these, styrene is preferred as the aromatic vinyl monomer.

[0067] The content of aromatic vinyl monomer units in the conjugated diene polymer is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 45% by mass or more, and is preferably 70% by mass or less, and more preferably 65% ​​by mass or less, when all repeating units (all monomer units and all structural units) contained in the conjugated diene polymer are taken as 100% by mass.

[0068] [Hydrophilic Group-Containing Structural Unit] In a conjugated diene polymer, the hydrophilic group-containing structural unit may be a structural unit formed by a hydrophilic group-containing monomer, or may be a structural unit obtained by obtaining a water-soluble polymer using a monomer composition containing a monomer having a specific functional group and then modifying or converting the functional group into a hydrophilic group. However, when the hydrophilic group-containing structural unit is a hydroxyl group-containing structural unit, the hydrophilic group-containing structural unit in the conjugated diene polymer is usually a hydrophilic group-containing structural unit introduced into the polymer by the above method (1). Examples of hydrophilic group-containing monomers that can be used to prepare a conjugated diene polymer include the same monomers as those described in the above section "Hydrophilic Group-Containing Structural Unit." These may be used alone or in combination of two or more. Among these, acid group-containing monomers are preferred as the hydrophilic group-containing monomer. The acid group-containing monomer is preferably a carboxylic acid group-containing monomer, more preferably acrylic acid, methacrylic acid, itaconic acid, and vinyl sulfonic acid, and even more preferably acrylic acid, methacrylic acid, and itaconic acid.

[0069] The content of the hydrophilic group-containing structural unit in the conjugated diene polymer is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, when all repeating units (all monomer units and all structural units) contained in the conjugated diene polymer are taken as 100% by mass.

[0070] [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 the cyano group-containing monomer include acrylonitrile and methacrylonitrile. These may be used alone or in combination of two or more in any ratio. Among these, acrylonitrile is preferred as the cyano group-containing monomer.

[0071] The cyano group-containing monomer units in the conjugated diene polymer preferably account for 5% by mass or more, more preferably 10% by mass or more, and preferably 25% by mass or less, more preferably 20% by mass or less, when all repeating units (all monomer units and all structural units) contained in the conjugated diene polymer are taken as 100% by mass.

[0072] [Other Monomer Units B] The other monomer units B are monomer units that can be formed by other monomers B. The other monomers B are not particularly limited as long as they are copolymerizable with the monomers that can form the conjugated diene polymers described above. Examples of the other monomers B include amide group-containing monomers such as acrylamide and methacrylamide; crosslinkable monomers (crosslinkable monomers) such as allyl glycidyl ether and allyl (meth)acrylate; olefins such as ethylene and propylene; halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl butyrate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether; vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone, and isopropenyl vinyl ketone; and N-vinylpyrrolidone. heterocycle-containing vinyl compounds such as vinylpyridine and vinylimidazole; amino group-containing monomers such as aminoethyl vinyl ether and dimethylaminoethyl vinyl ether; (meth)acrylic acid alkyl ester monomers 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; and the like. These other monomers B may be used singly or in combination of two or more.

[0073] The content of the other monomer units B in the conjugated diene polymer is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and even more preferably 0% by mass, i.e., the conjugated diene polymer does not contain any other monomer units B, when all repeating units (all monomer units and all structural units) contained in the conjugated diene polymer are taken as 100% by mass.

[0074] When a (meth)acrylic acid alkyl ester monomer is used to prepare the conjugated diene polymer, the content of the (meth)acrylic acid alkyl ester monomer unit is less than 50 mass % when the total repeating units (total monomer units and total structural units) contained in the conjugated diene polymer is 100 mass %.

[0075] <<Acrylic Polymer>> The acrylic polymer is a polymer containing (meth)acrylic acid alkyl ester monomer units. The acrylic polymer may optionally contain aromatic vinyl monomer units, hydrophilic group-containing structural units, and cyano group-containing monomer units. The acrylic polymer may also contain monomer units other than (meth)acrylic acid alkyl ester monomer units, aromatic vinyl monomer units, hydrophilic group-containing structural units, and cyano group-containing monomer units (hereinafter, sometimes referred to as "other monomer units C"). Note that the acrylic polymer is typically a polymer containing 50% by mass or more of (meth)acrylic acid alkyl ester monomer units, with the total repeating units (total monomer units and total structural units) contained in the acrylic polymer being 100% by mass, and is different from the above-mentioned conjugated diene polymers.

[0076] [(Meth)acrylic acid alkyl ester monomer unit] The (meth)acrylic acid alkyl ester monomer unit is a monomer unit that can be formed by a (meth)acrylic acid alkyl ester monomer. Examples of the (meth)acrylic acid alkyl ester monomer that can be used in the preparation of the acrylic polymer include the same monomers as those explained in the above section "(meth)acrylic acid alkyl ester monomer unit." These may be used alone or in combination of two or more.

[0077] The content of (meth)acrylic acid alkyl ester monomer units in the acrylic polymer is usually 50% by mass or more, preferably 55% by mass or more, and preferably 98% by mass or less, and more preferably 95% by mass or less, when all repeating units (all monomer units and all structural units) contained in the acrylic polymer are taken as 100% by mass.

[0078] [Aromatic vinyl monomer unit] The aromatic vinyl monomer unit is a monomer unit that can be formed by an aromatic vinyl monomer. Examples of the aromatic vinyl monomer unit that can be used to prepare the acrylic polymer include the same monomers as those described in the above section "Aromatic vinyl monomer unit". These may be used alone or in combination of two or more.

[0079] The content of aromatic vinyl monomer units in the acrylic polymer is preferably 10% by mass or more, more preferably 20% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, when all repeating units (all monomer units and all structural units) contained in the acrylic polymer are taken as 100% by mass.

[0080] [Hydrophilic Group-Containing Structural Unit] In an acrylic polymer, the hydrophilic group-containing structural unit may be a structural unit formed by a hydrophilic group-containing monomer, or may be a structural unit obtained by obtaining a water-soluble polymer using a monomer composition containing a monomer having a specific functional group and then modifying or converting the functional group into a hydrophilic group. However, when the hydrophilic group-containing structural unit is a hydroxyl group-containing structural unit, the hydrophilic group-containing structural unit in the acrylic polymer is usually a hydrophilic group-containing structural unit introduced into the polymer by the above method (1). Examples of hydrophilic group-containing monomers that can be used to prepare an acrylic polymer include the same monomers as those described in the above section "Hydrophilic Group-Containing Structural Unit." These may be used alone or in combination of two or more. Among these, acid group-containing monomers are preferred as the hydrophilic group-containing monomer. Examples of acid group-containing monomers include acrylic acid, methacrylic acid, itaconic acid, and vinyl sulfonic acid.

[0081] The content of the hydrophilic group-containing structural unit in the acrylic polymer is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, when all repeating units (all monomer units and all structural units) contained in the acrylic polymer are taken as 100% by mass.

[0082] [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 that can be used to prepare the acrylic polymer include the same monomers as those described in the above section "Cyano Group-Containing Monomer Unit." These may be used alone or in combination of two or more types in any ratio.

[0083] The content of the cyano group-containing monomer unit in the acrylic polymer is preferably 1% by mass or more, more preferably 3% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, when all repeating units (all monomer units and all structural units) contained in the acrylic polymer are taken as 100% by mass.

[0084] [Other Monomer Units C] The other monomer units C are monomer units that can be formed by other monomers C. The other monomers C are not particularly limited as long as they are monomers that can be copolymerized with the above-mentioned monomers that can form the acrylic polymer. Examples of other monomers C include amide group-containing monomers such as acrylamide and methacrylamide; crosslinkable monomers (crosslinkable monomers) such as allyl glycidyl ether and allyl (meth)acrylate; olefins such as ethylene and propylene; halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; vinyl esters such as vinyl acetate, vinyl propionate, and vinyl butyrate; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and butyl vinyl ether; vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone, and isopropenyl vinyl ketone; heterocycle-containing vinyl compounds such as N-vinylpyrrolidone, vinylpyridine, and vinylimidazole; and amino group-containing monomers such as aminoethyl vinyl ether and dimethylaminoethyl vinyl ether. These may be used alone or in combination of two or more.

[0085] The content of the other monomer units C in the acrylic polymer is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and even more preferably 0% by mass, i.e., the acrylic polymer does not contain any other monomer units C, when all repeating units (all monomer units and all structural units) contained in the acrylic polymer are taken as 100% by mass.

[0086] <<Glass Transition Temperature of Particulate Polymer>> The glass transition temperature of the particulate polymer is preferably −60° C. or higher, more preferably −50° C. or higher, and is preferably −10° C. or lower, more preferably −15° C. or lower.

[0087] <<Volume Average Particle Diameter of Particulate Polymer>> The volume average particle diameter of the particulate polymer is preferably 0.01 μm or more, more preferably 0.02 μm or more, and is preferably 1.0 μm or less, more preferably 0.8 μm or less, and even more preferably 0.5 μm or less.

[0088] <<Particulate Polymer Content>> The content of the particulate polymer in the slurry composition is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, relative to 100 parts by mass of the dielectric material.

[0089] <<Method for Preparing Particulate Polymer>> The polymerization method for the particulate polymer 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 also be commonly used amounts.

[0090] <Water> The slurry composition of the present invention contains water as a solvent. Note that the slurry composition of the present invention may contain a solvent other than water as long as the object of the present invention is not impaired. However, from the viewpoints of wettability of the dielectric layer, reduction of environmental load, and safety, it is preferable that the slurry composition of the present invention contains only water as a solvent.

[0091] <Other Component A> The slurry composition of the present invention may contain other component A. Examples of other component A include the above-mentioned additives used when polymerizing the water-soluble polymer and any particulate polymer.

[0092] <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.

[0093] <Method for preparing slurry composition for dielectric layer> The above-mentioned slurry composition can be prepared by a known method by mixing the above-mentioned dielectric material, water-soluble polymer, antifoaming agent, water, any particulate polymer, and other component A. Specifically, the slurry composition can be prepared by mixing the above-mentioned components using a mixer such as a ball mill, sand mill, bead mill, pigment disperser, crusher, ultrasonic disperser, homogenizer, planetary mixer, Filmix, or planetary / revolution mixer.

[0094] (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 water as a solvent from a coating film made from the slurry composition of the present invention. That is, the dielectric layer of the present invention comprises the above-described dielectric material, a water-soluble polymer, and an antifoaming agent, and optionally a particulate polymer, water, and other component A. The dielectric layer of the present invention is formed by drying a coating film made from the slurry composition of the present invention, which can impart excellent wettability to the dielectric layer, and therefore has excellent wettability. Furthermore, the dielectric layer of the present invention is formed by drying a coating film made from the slurry composition of the present invention, which has an excellent drying rate, and therefore has excellent productivity. Furthermore, the dielectric layer of the present invention has a high relative dielectric constant because it is formed by drying a coating film made from the slurry composition of the present invention, which can increase the coating density of the film.

[0095] 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.

[0096] The content of the water-soluble polymer in the dielectric layer is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, based on 100 parts by mass of the dielectric material in the dielectric layer.

[0097] The content of the antifoaming agent in the dielectric layer is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 1 part by mass or less, preferably 0.1 parts by mass or less, based on 100 parts by mass of the dielectric material in the dielectric layer.

[0098] In the dielectric layer, the mass ratio of the antifoaming agent to the water-soluble polymer (“antifoaming agent” / “water-soluble polymer”) is preferably 0.001 or more, more preferably 0.01 or more, and is preferably 0.1 or less, more preferably 0.08 or less.

[0099] The content of the optional particulate polymer in the dielectric layer is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, based on 100 parts by mass of the dielectric material in the dielectric layer.

[0100] 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.

[0101] <Method for Producing Dielectric Layer> The dielectric layer can be produced by applying the slurry composition of the present invention onto a release substrate or the like and drying the formed coating film. Details will be described later in the section "Dielectric Layer Formation Step".

[0102] (Laminate for Multilayer Ceramic Capacitor) The laminate for multilayer ceramic capacitor of the present invention comprises the above-described dielectric layer of the present invention and an internal electrode layer provided on the surface of the dielectric layer. Furthermore, in the laminate of the present invention, the internal electrode layer contains a conductive material and a binder. Here, since the laminate of the present invention comprises the dielectric layer of the present invention, which has excellent wettability, adhesion between the dielectric layer and the internal electrode layer is high, and excellent performance can be imparted to the multilayer ceramic capacitor. Furthermore, since the laminate of the present invention comprises the dielectric layer of the present invention, which has excellent productivity, it has excellent productivity. Furthermore, since the laminate of the present invention comprises the dielectric layer of the present invention, which has a high relative dielectric constant, it can impart excellent performance to the multilayer ceramic capacitor. The laminate of the present invention may optionally further comprise layers other than the dielectric layer and the internal electrode layer (hereinafter, sometimes referred to as "other layers"). Examples of other layers include a release substrate.

[0103] <Dielectric Layer> The dielectric layer has been described above in the section "Dielectric Layer," so a description thereof will be omitted here.

[0104] <Internal electrode layer> The internal electrode layer includes a conductive material and a binder, and may optionally include a dielectric material. The internal electrode layer may also include components other than the conductive material, binder, and dielectric material (hereinafter, sometimes referred to as "other component B"). Here, the internal electrode layer is formed by drying a coating film made of a conductive paste containing a conductive material, binder, organic solvent, optional dielectric material, and optional other component B, as described below. The internal electrode layer is usually a dried film obtained by partially or completely removing the organic solvent from the coating film made of the conductive paste. That is, the internal electrode layer includes a conductive material and a binder, and optionally contains an organic solvent, a dielectric material, and other component B. The internal electrode layer usually has a predetermined electrode pattern.

[0105] <<Conductive Material>> The conductive material is not particularly limited, and for example, powder of one or more elements selected from Ni, Pd, Pt, Au, Ag, Cu, and alloys thereof can be used. Among these, Ni powder or Ni alloy powder is preferred from the viewpoints of conductivity, corrosion resistance, and cost. As the Ni alloy, for example, an alloy of Ni and at least one element selected from the group consisting of Mn, Cr, Co, Al, Fe, Cu, Zn, Ag, Au, Pt, and Pd can be used. The Ni content in the Ni alloy is usually 50% by mass or more, preferably 80% by mass or more. Furthermore, the Ni powder may contain about several hundred ppm of S (sulfur) to suppress rapid gas generation due to partial thermal decomposition of the polymer B during binder removal treatment.

[0106] The average particle diameter of the conductive material is preferably 0.05 μm or more, more preferably 0.1 μm or more, and preferably 1.0 μm or less, and more preferably 0.5 μm or less. If the average particle diameter of the conductive material is within the above range, the smoothness and density of the internal electrode layer can be improved. In this specification, the average particle diameter of the conductive material is a particle diameter calculated from the specific surface area obtained based on the BET method, unless otherwise specified. For example, the average particle diameter of Ni powder can be calculated using the following formula (1): Average particle diameter = 6 / S.A × ρ (1) (ρ = 8.9 (true density of Ni), S.A = BET specific surface area of ​​Ni powder)

[0107] The content ratio of the conductive material in the internal electrode layer is preferably 60% by mass or more, more preferably 70% by mass or more, and is preferably 90% by mass or less, and more preferably 85% by mass or less, when the total amount of all components in the internal electrode layer is 100% by mass.

[0108] <<Binder>> The binder contained in the internal electrode layers is a component that holds the material (for example, conductive material) contained in the internal electrode layers so that it does not come off from the internal electrode layers.

[0109] Here, the binder may be the same polymer as that described in the above section "Water-soluble polymer." The binder contained in the internal electrode layer is preferably polyvinyl acetal obtained by acetalizing a portion of the hydroxyl groups of a water-soluble polymer having hydroxyl groups (for example, the water-soluble polymer obtained by the above method (2)), and more preferably polyvinyl butyral obtained by acetalizing the hydroxyl groups of a water-soluble polymer with butyraldehyde.

[0110] The content of the binder in the internal electrode layer may be, for example, 0.1 parts by mass or more, 1 part by mass or more, or 2 parts by mass or more, or may be, for example, 15 parts by mass or less, 10 parts by mass or less, or 5 parts by mass or less, assuming that the conductive material is 100 parts by mass.

[0111] <<Dielectric Material>> Examples of the dielectric material that can be contained in the internal electrode layers include the same dielectric materials as those described above in the section "Dielectric Material". Among these, the dielectric material that can be contained in the internal electrode layers is preferably a ceramic material having a perovskite structure as a main phase, and more preferably barium titanate or calcium zirconate.

[0112] Here, it is preferable to use a dielectric material that can be contained in the internal electrode layers that has the same composition as the dielectric material contained in the dielectric layers, since this can effectively prevent cracks from occurring at the interface between the dielectric layer and the internal electrode layer due to differences in shrinkage rate, etc. For example, when the dielectric material contained in the dielectric layers is barium titanate, it is preferable that the dielectric material that can be contained in the internal electrode layers is barium titanate, and when the dielectric material contained in the dielectric layers is calcium zirconate, it is preferable that the dielectric material that can be contained in the internal electrode layers is calcium zirconate.

[0113] The content of the dielectric material in the internal electrode layer is, for example, 5 parts by mass or more, 10 parts by mass or more, or 20 parts by mass or more, for example, 50 parts by mass or less, 40 parts by mass or less, or 30 parts by mass or less, assuming that the conductive material is 100 parts by mass.

[0114] <<Other Components B>> The internal electrode layers may contain other components B. Examples of the other components B include additives used when polymerizing the binder contained in the internal electrode layers. Examples of the additives used when polymerizing the binder include surfactants.

[0115] <Release Substrate> The laminate of the present invention may have a release substrate on the surface of the dielectric layer opposite to the surface on which the internal electrode layer is provided. That is, the laminate of the present invention may be formed by laminating a release substrate, a dielectric layer, and an internal electrode layer in this order.

[0116] Here, the release substrate is preferably made of a flexible resin. When the release substrate is made of a flexible resin, the laminate 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.

[0117] The release substrate is preferably subjected to a surface treatment on the side on which the dielectric layer is formed to improve releasability. 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.

[0118] The thickness of the release substrate is not particularly limited, but is usually 20 μm or more and 100 μm or less.

[0119] (Method for manufacturing a laminate for a multilayer ceramic capacitor) The method for manufacturing a laminate for a multilayer ceramic capacitor of the present invention, which comprises a dielectric layer and an internal electrode layer provided on the surface of the dielectric layer (hereinafter, sometimes simply referred to as the "manufacturing method"), includes a dielectric layer forming step of applying the above-described slurry composition of the present invention to a release substrate and drying the applied film to form a dielectric layer, and an internal electrode layer forming step of applying a conductive paste containing a conductive material, a binder, and an organic solvent to the dielectric layer and drying the applied film to form an internal electrode layer. The above manufacturing method can obtain a laminate that can impart excellent performance to a multilayer ceramic capacitor. Furthermore, the above manufacturing method can obtain a laminate with excellent productivity.

[0120] The manufacturing method of the present invention may optionally further include a peeling step of peeling the obtained dielectric layer and internal electrode layer from the release substrate.

[0121] <<Dielectric Layer Forming Step>> In the dielectric layer forming step, the slurry composition of the present invention is applied onto a release substrate, and the applied film is dried to form a dielectric layer.

[0122] The slurry composition has been explained above in the section "Slurry composition for dielectric layer," so a description thereof will be omitted here.

[0123] 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).

[0124] 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.

[0125] <<Internal Electrode Layer Forming Process>> In the internal electrode layer forming process, a conductive paste containing a conductive material, a binder, and an organic solvent is applied onto the dielectric layer obtained in the dielectric layer forming process, and the applied film is dried to form an internal electrode layer.

[0126] Here, the organic solvent contained in the conductive paste is not particularly limited, but examples thereof include terpene-based solvents such as terpineol and dihydroterpineol; alcohol-based solvents such as methanol and ethanol; etc. Among these, terpene-based solvents are preferred, and terpineol is more preferred, from the viewpoint of increasing the drying rate.

[0127] The solid content concentration of the conductive paste is, for example, 20% by mass or more, or may be 40% by mass or more, or 50% by mass or more, and may be, for example, 90% by mass or less, or may be 80% by mass or less.

[0128] The conductive paste can be prepared by mixing a conductive material, a binder, an organic solvent, an optional dielectric material, and any other optional component B by a known method.

[0129] (Multilayer ceramic capacitor) The multilayer ceramic capacitor of the present invention is a sintered product obtained by sintering the above-described laminate of the present invention. The multilayer ceramic capacitor of the present invention has excellent performance because it is obtained by sintering the laminate of the present invention, which can impart excellent performance to the multilayer ceramic capacitor. Furthermore, the multilayer ceramic capacitor of the present invention has excellent productivity because it is obtained by sintering the laminate of the present invention, which has excellent productivity. 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.

[0130] FIG. 1 is a schematic cross-sectional view showing an example of a multilayer ceramic capacitor of 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 outside 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 inside 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 inside 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 boundary surfaces between the dielectric layers that may be formed when the laminate of the present invention is stacked are not shown in FIG. 1 because they may disappear when the dielectric layers are integrated together by sintering.

[0131] 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 optionally peeling the dielectric layers and the internal electrode layers from the release substrate, stacking the laminates of the present invention so that the dielectric layers and the internal electrode layers are alternately arranged, heat-pressing the laminates, thermally decomposing and removing binder components and the like contained in the dielectric layers and the internal electrode layers (degreasing treatment), sintering the laminates, and forming external electrodes on the end faces of the sintered ceramic product obtained by sintering.

[0132] 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 total content of binder components in the dielectric layers and internal electrode layers after the degreasing treatment is usually 50 ppm or less.

[0133] 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.

[0134] 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.

[0135] 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 glass transition temperatures, weight average molecular weights, wettability, drying speed, and coating density of the water-soluble polymer and particulate polymer were measured and evaluated according to the following procedures. In addition, the water-soluble polymers shown below were used.

[0136] <Glass Transition Temperature of Water-Soluble Polymer and Particulate Polymer> An aqueous solution of a water-soluble polymer or a dispersion of a particulate polymer was 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 at 60°C for 10 hours using a vacuum dryer. Thereafter, the glass transition temperature (°C) of the dried film was measured using a differential scanning calorimeter (DSC6220, manufactured by SII NanoTechnology Inc.) in accordance with JIS K7121 under the conditions of a measurement temperature of -100°C to 180°C and a heating rate of 5°C / min.

[0137] <Weight-average molecular weight of water-soluble polymer> The weight-average molecular weight of the water-soluble polymer was measured by gel permeation chromatography (GPC). Specifically, the water-soluble polymer was first added to about 5 mL of eluent so that the solid concentration was about 0.5 g / L, and slowly dissolved at room temperature. After visually confirming the dissolution of the water-soluble polymer, the solution was gently filtered through a 0.45 μm filter to prepare a measurement sample, which was then used for measurement. Then, a calibration curve was created using a standard substance, and the weight-average molecular weight was calculated as a value converted from the standard substance. The measurement conditions were as follows: <<Measurement conditions>> Column: Showa Denko K.K., product name Shodex OHpak (SB-G, SB-807HQ, SB-806MHQ) Eluent: 0.1 M Tris buffer solution (0.1 M potassium chloride added) Flow rate: 0.5 mL / min Sample concentration: 0.05 g / L (solids concentration) Injection volume: 200 μL Column temperature: 40°C Detector: Differential refractive index detector RI (Tosoh Corporation, product name "RI-8020") Standard substance: Monodispersed pullulan (Showa Denko K.K.)

[0138] <Wettability> A slurry composition was prepared in the same manner as in each Example and Comparative Example, except that no dielectric material was used in the slurry composition. This slurry composition was used as an evaluation slurry composition to evaluate wettability. Specifically, 100 parts of Ni powder (average particle size: 0.3 μm) as a conductive material, 25 parts of barium titanate ("BT-01" manufactured by Sakai Chemical Industry Co., Ltd.) as a dielectric material, 2 parts of polyvinyl butyral (BL-2H manufactured by Sekisui Chemical Co., Ltd.) as a binder, and 65 parts of terpineol as an organic solvent were mixed to prepare a conductive paste (solid concentration 66%). The evaluation slurry composition was then applied to a polyethylene terephthalate (PET) substrate to form a 5 μm thick coating film, which was then dried at 100° C. for 10 minutes. Next, 1 μL of conductive paste was dropped onto the obtained coating film, and the contact angle (°) formed between the coating film and the droplet of conductive paste after 10 seconds was measured, and wettability was evaluated according to the following criteria. A: Contact angle of 30° or less B: Contact angle of more than 30° and less than or equal to 40° C: Contact angle of more than 40°

[0139] <Drying Speed> The slurry compositions obtained in the Examples and Comparative Examples were applied to a PET substrate to a thickness of 20 μm, and the film weight before drying W ０ The resulting film was then dried at 100° C. for 1 minute, and the weight of the dried film W １ The weight loss rate of the film before and after drying ("(W ０ -W １ ) / W １ × 100(%)") was calculated and the drying speed was evaluated according to the following criteria. A larger weight loss rate indicates a better drying speed. A: 70% or more B: 60% or more but less than 70% C: 50% or more but less than 60% D: Less than 50%

[0140] <Coating Density> The slurry compositions obtained in the Examples and Comparative Examples were coated onto a PET substrate so as to have a length of 50 mm, a width of 50 mm, and a thickness of 20 μm, and the resulting film was dried at 100° C. for 5 minutes, and the weight W of the resulting dried film was measured. The density was then calculated using the film volume (length × width × thickness) and the weight W, and the coating density was evaluated according to the following criteria. A higher coating density means that a better relative dielectric constant can be imparted to the dielectric layer. A: 3.70 g / cm ３ or more B: 3.40g / cm ３ 3.70g / cm or more ３ Less than C: 3.40 g / cm ３ less than

[0141] <Preparation of Aqueous Solution of Water-Soluble Polymer A> A 5 ​​MPa pressure vessel equipped with a stirrer was charged with 35 parts of methacrylic acid (hydrophilic group-containing monomer), 52 parts of ethyl acrylate ((meth)acrylic acid alkyl ester monomer), and 13 parts of n-butyl acrylate ((meth)acrylic acid alkyl ester monomer) as a monomer composition, as well as 0.6 parts of sodium dodecylbenzenesulfonate as an emulsifier, 150 parts of ion-exchanged water, and 1 part of potassium persulfate as a polymerization initiator. After thorough stirring, the mixture was heated to 60°C to initiate polymerization. When the polymerization conversion rate reached 96%, the mixture was cooled to terminate the reaction, and an aqueous sodium hydroxide solution was added to adjust the pH to 4, thereby obtaining an aqueous solution of water-soluble polymer A. Using the obtained aqueous solution of water-soluble polymer A, the glass transition temperature of water-soluble polymer A and the weight average molecular weight of water-soluble polymer A were measured. The results are shown in Table 1.

[0142] <Preparation of Aqueous Solution of Water-Soluble Polymer B> An aqueous solution of water-soluble polymer B was obtained in the same manner as in the preparation of the aqueous solution of water-soluble polymer A, except that the amount of potassium persulfate used as the polymerization initiator was changed from 1 part to 2 parts. Using the obtained aqueous solution of water-soluble polymer B, the glass transition temperature and weight average molecular weight of water-soluble polymer B were measured. The results are shown in Table 1.

[0143] <Preparation of Aqueous Solution of Water-Soluble Polymer C> An aqueous solution of water-soluble polymer C was obtained in the same manner as in the preparation of the aqueous solution of water-soluble polymer A, except that the amount of potassium persulfate used as the polymerization initiator was changed from 1 part to 0.5 parts. Using the obtained aqueous solution of water-soluble polymer C, the glass transition temperature and weight average molecular weight of water-soluble polymer C were measured. The results are shown in Table 1.

[0144] <Preparation of Aqueous Solution of Water-Soluble Polymer D> Polyvinyl alcohol (Denka Poval (registered trademark) B-33, manufactured by Denka Co., Ltd.) was prepared as a water-soluble polymer containing a hydroxyl group-containing structural unit. The polyvinyl alcohol and ion-exchanged water were mixed to a solids concentration of 10%, thereby obtaining an aqueous solution of water-soluble polymer D. The glass transition temperature and weight-average molecular weight of water-soluble polymer D are shown in Table 1.

[0145] Example 1 Preparation of Particulate Polymer Dispersion A 5 MPa pressure vessel equipped with a stirrer was charged with 76 parts of 2-ethylhexyl acrylate, 20 parts of acrylonitrile, and 4 parts of itaconic acid as a monomer composition, as well as 4 parts of sodium lauryl sulfate as an emulsifier, 150 parts of ion-exchanged water, and 0.5 parts of ammonium persulfate as a polymerization initiator. After thorough stirring, the mixture was heated to 80°C to initiate polymerization. The reaction was stopped by cooling when the polymerization conversion rate reached 96.0%. A 5% aqueous solution of sodium hydroxide was added to the aqueous dispersion containing the polymer obtained in this manner, and the pH was adjusted to 7. Subsequently, unreacted monomer was removed by heating and distillation under reduced pressure. The mixture was then cooled to a temperature of 30°C or below, yielding a dispersion containing an acrylic particulate polymer (ACL). The glass transition temperature of the resulting particulate polymer dispersion was measured. The results are shown in Table 2.

[0146] <Preparation of Dielectric Layer 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, 2.5 parts of the aqueous solution of water-soluble polymer A prepared above (containing 1 part of water-soluble polymer A), and 40 parts of water as the solvent were stirred together 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"). Then, 27 parts of water were further added, and the mixture was stirred at 500 rpm for 10 hours. The zirconia beads were filtered off, and a dispersion of barium titanate was prepared. To 169.55 parts of the above-mentioned dispersion of barium titanate (containing 100 parts of barium titanate), 30 parts of the dispersion of particulate polymer prepared above (containing 12 parts of particulate polymer) and 0.05 parts of silicone oil (silicone-based antifoaming agent, manufactured by Seiko PMC Corporation, DF6351) as an antifoaming agent were added, and these were stirred at 1000 rpm for 3 minutes using a planetary centrifugal mixer to prepare a slurry composition (solid concentration 56.6%). Various evaluations were performed using the obtained slurry composition. The results are shown in Table 2.

[0147] Example 2 Except for changing the amount of antifoaming agent used from 0.05 part to 0.005 part, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 2.

[0148] (Example 3) Except for changing the amount of antifoaming agent used from 0.05 part to 0.2 part, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 2.

[0149] (Example 4) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that the antifoaming agent was changed from silicone oil to an acetylene glycol-based surfactant (nonionic surfactant, Surfynol (registered trademark) SE-F, manufactured by Nissin Chemical Industry Co., Ltd.). The results are shown in Table 2.

[0150] Example 5 Except for changing the amount of water-soluble polymer A used from 1 part to 0.2 parts, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 2.

[0151] Example 6 Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that the amount of water-soluble polymer A used was changed from 1 part to 8 parts. The results are shown in Table 2.

[0152] (Example 7) Except for not using a dispersion of a particulate polymer, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 2.

[0153] Example 8 Except for changing the dielectric material of the slurry composition from barium titanate to calcium zirconate, various operations, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 2.

[0154] (Example 9) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that the aqueous solution of water-soluble polymer B was used instead of the aqueous solution of water-soluble polymer A. The results are shown in Table 2.

[0155] (Example 10) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that the aqueous solution of water-soluble polymer C was used instead of the aqueous solution of water-soluble polymer A. The results are shown in Table 2.

[0156] (Example 11) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that the aqueous solution of water-soluble polymer D was used instead of the aqueous solution of water-soluble polymer A. The results are shown in Table 2.

[0157] Comparative Example 1 Except for not using an antifoaming agent, various operations, measurements, and evaluations were carried out in the same manner as in Example 11. The results are shown in Table 2.

[0158] Comparative Example 2 The various operations, measurements, and evaluations were carried out in the same manner as in Example 11, except that the antifoaming agent was changed from silicone oil to an acetylene glycol surfactant and the amount of antifoaming agent used was changed from 0.05 part to 0.0005 part. The results are shown in Table 2.

[0159] (Comparative Example 3) Various operations, measurements, and evaluations were carried out in the same manner as in Example 11, except that the antifoaming agent was changed from silicone oil to an acetylene glycol surfactant and the amount of antifoaming agent used was changed from 0.05 parts to 1.5 parts. The results are shown in Table 2.

[0160] In Tables 1 and 2 shown below, "EA" represents an ethyl acrylate unit, "BA" represents an n-butyl acrylate unit, "MAA" represents a methacrylic acid unit, and "BaTiO ３ " indicates barium titanate, and "CaZrO ３ " indicates calcium zirconate, "acetylene glycol" indicates an acetylene glycol surfactant, "ACL" indicates an acrylic particulate polymer, and "defoamer / water-soluble polymer" indicates the mass ratio of the defoamer to the water-soluble polymer.

[0161]

[0162]

[0163] As is clear from Table 2, the slurry compositions of the examples can impart excellent wettability to the dielectric layer.

[0164] According to the present invention, it is possible to provide a slurry composition for a dielectric layer that can impart excellent wettability to a dielectric layer. Further, according to the present invention, it is possible to provide a dielectric layer that has excellent wettability. Further, according to the present invention, it is possible to provide a laminate for a multilayer ceramic capacitor that can impart excellent performance to a multilayer ceramic capacitor, and a method for producing the same. Further, according to the present invention, it is possible to provide a multilayer ceramic capacitor that has excellent performance.

[0165] 10: Multilayer ceramic capacitor 11: Dielectric 12: Internal electrode 13: External electrode

Claims

1. A slurry composition for a dielectric layer comprising a dielectric material having a perovskite structure, a water-soluble polymer, an antifoaming agent, and water, wherein the content of the antifoaming agent is 0.001 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the dielectric material.

2. A slurry composition for a dielectric layer according to claim 1, wherein the water-soluble polymer has a weight average molecular weight of 100,000 or more and 2,000,000 or less.

3. The slurry composition for a dielectric layer according to claim 1, wherein the antifoaming agent is at least one of a silicone-based antifoaming agent and a nonionic surfactant.

4. The slurry composition for a dielectric layer according to claim 1, wherein said water-soluble polymer contains a structural unit having a hydrophilic group, and said hydrophilic group is at least one of a carboxylic acid group and a hydroxyl group.

5. A slurry composition for a dielectric layer according to claim 1, wherein the content of the water-soluble polymer is 0.1 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the dielectric material.

6. A slurry composition for a dielectric layer according to claim 1, wherein a mass ratio of said antifoaming agent to said water-soluble polymer is 0.001 or more and 0.1 or less.

7. The dielectric layer slurry composition of claim 1, further comprising a particulate polymer.

8. A dielectric layer obtained by drying a coating film made of the slurry composition for a dielectric layer according to any one of claims 1 to 7.

9. A laminate for a multilayer ceramic capacitor, comprising the dielectric layer according to claim 8 and an internal electrode layer provided on the surface of said dielectric layer, said internal electrode layer including a conductive material and a binder.

10. A method for producing a laminate for a multilayer ceramic capacitor, comprising a dielectric layer and an internal electrode layer provided on a surface of the dielectric layer, the method comprising: a dielectric layer forming step of applying a slurry composition for a dielectric layer according to any one of claims 1 to 7 onto a release substrate, and drying the applied film to form a dielectric layer; and an internal electrode layer forming step of applying a conductive paste containing a conductive material, a binder, and an organic solvent onto the dielectric layer, and drying the applied film to form an internal electrode layer.

11. The method for producing a laminate for a multilayer ceramic capacitor according to claim 10, wherein the organic solvent is a terpene-based solvent.

12. The method for producing a laminate for a multilayer ceramic capacitor according to claim 10, wherein the conductive material is a powder of Ni or a Ni alloy.

13. A multilayer ceramic capacitor obtained by sintering the laminate for a multilayer ceramic capacitor according to claim 9.