Composition, slurry composition, dielectric layer, and multilayer ceramic capacitor

Abstract

The objective of the present invention is to provide a composition capable of imparting excellent wettability with a release base material and dispersion stability to a slurry composition, and also capable of imparting excellent wettability with a conductive paste to a dielectric layer. The present invention relates to a composition comprising a water-soluble polymer, a compound having an isothiazolinone structure, and a dielectric material having a perovskite structure.

Description

COMPOSITION, SLURRY COMPOSITION, DIELECTRIC LAYER, AND MULTILAYER CERAMIC CAPACITOR

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

[0002] Multilayer ceramic capacitors are generally manufactured using dielectric layers such as ceramic green sheets. The dielectric layers can be obtained, for example, by first preparing a slurry composition containing a binder, a dielectric material, and a solvent, then applying the slurry composition to a release substrate 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, in the production of a dielectric layer such as a ceramic green sheet, a slurry composition used to form the dielectric layer can be applied to a release substrate to form a coating film. From the viewpoint of obtaining a uniform coating film and enabling the multilayer ceramic capacitor to exhibit excellent performance, it is desirable that the slurry composition have excellent wettability with the release substrate.

[0006] Furthermore, an internal electrode layer (conductive film) can be formed on the dielectric layer by applying a conductive paste, and from the viewpoint of achieving good adhesion between the dielectric layer and the internal electrode layer and imparting excellent performance to the resulting multilayer ceramic capacitor, it is desirable that the dielectric layer have excellent wettability with the conductive paste.

[0007] Furthermore, since the slurry composition can be stored for a certain period of time (e.g., 7 days) after preparation, it is desirable that the slurry composition has little change in viscosity when comparing the viscosity after storage for a certain period of time with the viscosity immediately after preparation, and has excellent dispersion stability, in order to enable uniform application and suppress variation in performance of the resulting multilayer ceramic capacitor.

[0008] Therefore, an object of the present invention is to provide a composition that can impart excellent wettability and dispersion stability with a release substrate to a slurry composition and excellent wettability with a conductive paste to a dielectric layer. Another object of the present invention is to provide a slurry composition containing the composition. Another object of the present invention is to provide a dielectric layer having a dried film formed by drying a coating film using the slurry composition. Another object of the present invention is to provide a multilayer ceramic capacitor having a dielectric using the dielectric layer.

[0009] The present inventors have conducted extensive research with the aim of solving the above problems, and have newly discovered that the above problems can be solved by a composition containing a water-soluble polymer, a predetermined compound, and a predetermined dielectric material, thereby completing the present invention.

[0010] That is, an object of the present invention is to advantageously solve the above-mentioned problems, and [1] the present invention is a composition containing a water-soluble polymer, a compound having an isothiazolinone structure, and a dielectric material having a perovskite structure.

[0011] [2] In the composition of the above [1], the water-soluble polymer is preferably an acrylic polymer.

[0012] [3] In the composition of the above [1] or [2], the water-soluble polymer preferably has a carboxy group.

[0013] [4] In any of the compositions [1] to [3] above, the content of the compound having an isothiazolinone structure is preferably 0.001 parts by mass or more and 1.0 parts by mass or less, relative to 100 parts by mass of the water-soluble polymer.

[0014] [5] In the composition of any one of the above [1] to [4], the compound having an isothiazolinone structure preferably further has an aromatic ring structure.

[0015] [6] It is preferable that any of the compositions [1] to [5] above further contains a particulate polymer.

[0016] The present invention also aims to advantageously solve the above problems. [7] The present invention is a slurry composition containing any of the compositions [1] to [6] above and a solvent.

[0017] [8] The slurry composition of [7] above is preferably for use in a multilayer ceramic capacitor.

[0018] The present invention also aims to advantageously solve the above-mentioned problems, and [9] the present invention is a dielectric layer having a dried film formed by drying a coating film using the slurry composition of [8] above.

[0019] Another object of the present invention is to advantageously solve the above problems, and

[10] the present invention is a multilayer ceramic capacitor having a dielectric using the dielectric layer according to [9] above.

[0020] According to the present invention, a composition can be provided that can impart excellent wettability and dispersion stability with a release substrate to a slurry composition and excellent wettability with a conductive paste to a dielectric layer. Furthermore, according to the present invention, a slurry composition containing the above composition can be provided. Furthermore, according to the present invention, a dielectric layer can be provided that includes a dried film formed by drying a coating film using the above slurry composition. Furthermore, according to the present invention, a multilayer ceramic capacitor can be provided that includes a dielectric using the above dielectric layer.

[0021] 1 is a schematic cross-sectional view showing an example of a multilayer ceramic capacitor of the present invention.

[0022] Hereinafter, embodiments of the present invention will be described in detail.

[0023] (Composition) The composition of the present invention contains a water-soluble polymer, a compound having an isothiazolinone structure, and a dielectric material having a perovskite structure, and may optionally contain a particulate polymer and a solvent. Such a composition can impart excellent wettability and dispersion stability with a release substrate to the slurry composition, and can impart excellent wettability with a conductive paste to the dielectric layer. This is presumably because the multiple polar elements and heterocycles present in the compound having an isothiazolinone structure, such as nitrogen, sulfur, and oxygen, act effectively in the slurry composition and the dielectric layer. In addition, since the compound having an isothiazolinone structure can function as a preservative, the composition of the present invention containing this compound has excellent preservative effect.

[0024] The composition of the present invention may optionally further contain a component other than the dielectric material, the water-soluble polymer, the compound having an isothiazolinone structure, the particulate polymer, and the solvent (hereinafter, this may be referred to as "other component A").

[0025] <Dielectric Material Having Perovskite Structure> In the composition of the present invention, the dielectric material has a perovskite structure. Here, the "perovskite structure" refers to a material having a 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 composition of the present invention may optionally further contain a dielectric material other than the dielectric material having a perovskite structure.

[0026] As a dielectric material having a perovskite structure, a ceramic material having a perovskite structure as a main phase is preferable. As the ceramic material, for example, 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 Srｙ Ti １－ｚ Zr ｚ O ３ (0≦x≦1, 0≦y≦1, 0≦z≦1), etc. Among these, barium titanate is preferred as a ceramic material having a perovskite structure as the main phase.

[0027] 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. If the volume average particle diameter of the dielectric material is above the above lower limit, the powder shedding resistance of the dielectric layer can be effectively improved. On the other hand, if the volume average particle diameter of the dielectric material is below the above upper limit, the dispersion stability of the resulting slurry composition can be effectively improved. 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.

[0028] <Water-soluble polymer> In the composition of the present invention, the water-soluble polymer is a component that can function as a viscosity modifier and a binder.

[0029] Here, the water-soluble polymer is not particularly limited, but preferably has a hydrophilic group, since this can improve the dispersion stability of the resulting slurry composition and the wettability of the resulting dielectric layer with the conductive paste. Examples of the hydrophilic group include acid groups such as carboxyl groups, sulfonic acid groups, and phosphate groups; hydroxyl groups; and amide groups. The hydrophilic group is preferably at least one of an acid group and a hydroxyl group, more preferably at least one of a carboxyl group and a hydroxyl group, and even more preferably a carboxyl group, since this can further improve the dispersion stability of the resulting slurry composition and the wettability of the resulting dielectric layer with the conductive paste. That is, the water-soluble polymer preferably has at least one of an acid group and a hydroxyl group, more preferably at least one of a carboxyl group and a hydroxyl group, and even more preferably a carboxyl group. When the water-soluble polymer has a hydrophilic group, the water-soluble polymer typically contains a structural unit having a hydrophilic group (hereinafter, sometimes referred to as a "hydrophilic group-containing structural unit").

[0030] The water-soluble polymer is not particularly limited, but preferably contains (meth)acrylic acid alkyl ester monomer units, and more preferably is an acrylic polymer, because this can improve the wettability of the resulting slurry composition with the release substrate. In this specification, "(meth)acrylic" means acrylic and / or methacrylic. In this specification, "acrylic polymer" usually means a polymer containing 50% by mass or more of (meth)acrylic acid alkyl ester monomer units, as described below, when all repeating units (all monomer units and all structural units) contained in the acrylic polymer are taken as 100% by mass.

[0031] The water-soluble polymer may further contain a monomer unit other than the above-mentioned hydrophilic group-containing structural unit and (meth)acrylic acid alkyl ester monomer unit (hereinafter, sometimes referred to as "other monomer unit A").

[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 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] Carboxy group-containing monomers capable of forming structural units having a carboxy group as a hydrophilic group (hereinafter sometimes referred to as "carboxy group-containing structural units") include monocarboxylic acids and their derivatives, dicarboxylic acids and their acid anhydrides, and their derivatives. 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 a carboxy group upon hydrolysis can also be used as carboxy 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 carboxy 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, 3-allyloxy-2-hydroxypropanesulfonic acid, etc. 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 hydroxy group as a hydrophilic group (hereinafter, sometimes referred to as a "hydroxy group-containing structural unit") is not particularly limited as long as it is a repeating unit having a hydroxy group. Methods for introducing a hydroxy 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 hydroxy group-containing structural unit from a monomer composition containing a hydroxy group-containing monomer; (2) A method for preparing a water-soluble polymer containing a hydroxy 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), and then saponifying the polymer to convert all or part of the "R-CO-O-" of the vinyl carboxylic acid ester monomer units to hydroxy groups, thereby preparing a water-soluble polymer containing vinyl alcohol units and, optionally, vinyl carboxylic acid ester monomer units.

[0038] Examples of the hydroxy 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) with (meth)acrylic acid; mono(meth)acrylic acid esters of dihydroxy esters of dicarboxylic acids such as 2-hydroxyethyl-2'-(meth)acryloyloxyethyl phthalate and 2-hydroxyethyl-2'-(meth)acryloyloxyethyl succinate; vinyl ethers such as 2-hydroxyethyl vinyl ether and 2-hydroxypropyl vinyl ether; mono(meth)acrylic acid esters of 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; allyl 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; N-2-hydroxyethyl(meth)acrylamide, N-methylolacrylamide; and the like. 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. Examples of water-soluble polymers obtainable by the above method (2) include polyvinyl alcohol.

[0040] When the water-soluble polymer is prepared by the method (2), a portion of the hydroxy groups of the obtained water-soluble polymer may be acetalized, such as polyvinyl butyral, in which the hydroxy groups of the water-soluble polymer are acetalized with butyraldehyde.

[0041] The content of the hydrophilic group-containing structural unit in the water-soluble polymer is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 50% by mass or less, when the total repeating units (total monomer units and total structural units) contained in the water-soluble polymer is taken as 100% by mass. 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, and even more preferably 50% by mass or more, and is preferably 90% by mass or less, 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.

[0048] <<Content of Water-Soluble Polymer>> In the composition of the present invention, the content of the water-soluble polymer is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, relative to 100 parts by mass of the dielectric material.

[0049] <<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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] <Compound Having an Isothiazolinone Structure> A compound having an isothiazolinone structure (hereinafter sometimes referred to as an "isothiazolinone compound") can function as a preservative in the composition. Here, the isothiazolinone compound is not particularly limited as long as it has an isothiazolinone skeleton in its structure, and is, for example, a compound represented by the following formula (I): (In formula (I), Y is a hydrogen atom or an optionally substituted hydrocarbon group, and X １ and X ２ are each independently a hydrogen atom, a halogen atom, or an optionally substituted alkyl group having 1 to 6 carbon atoms, or X １ and X ２ together form an aromatic ring. １ and X ２ do not cooperate to form an aromatic ring, X １ and X ２ may be the same or different.)

[0054] In formula (I), examples of the hydrocarbon group represented by Y include alkyl groups having 1 to 10 carbon atoms (e.g., methyl), alkenyl groups having 2 to 6 carbon atoms (e.g., vinyl, allyl), alkynyl groups having 2 to 6 carbon atoms (e.g., ethynyl, propynyl), cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl), and aryl groups having 6 to 14 carbon atoms (e.g., phenyl). Some or all of the hydrogen atoms in the hydrocarbon group represented by Y may be substituted with a substituent. Examples of such substituents include hydroxy groups, halogen atoms (e.g., chlorine, fluorine, bromine, iodine), cyano groups, amino groups, carboxy groups, alkoxy groups having 1 to 4 carbon atoms (e.g., methoxy, ethoxy), aryloxy groups having 6 to 10 carbon atoms (e.g., phenoxy), alkylthio groups having 1 to 4 carbon atoms (e.g., methylthio, ethylthio), and arylthio groups having 6 to 10 carbon atoms (e.g., phenylthio). When the hydrocarbon group of Y has a plurality of substituents, the substituents may be the same or different.

[0055] In formula (I), Y is preferably a methyl group or a hydrogen atom, and more preferably a hydrogen atom.

[0056] In formula (I), X １ and X ２ Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. １ and X ２ Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and a pentyl group. These alkyl groups may have some or all of their hydrogen atoms substituted with a substituent. Examples of such a substituent include the same as those described above as the substituent in the hydrocarbon group of Y. In formula (I), X １ and X ２ Examples of the aromatic ring formed by combining X include a benzene ring. １ and X ２are preferably each a hydrogen atom or together form an aromatic ring.

[0057] <<Isothiazolinone Compound Having an Aromatic Ring Structure>> Here, it is preferable that the isothiazolinone compound further has an aromatic ring structure, since this can improve the dispersion stability of the resulting slurry composition and the wettability of the resulting dielectric layer with the conductive paste. The isothiazolinone compound having an aromatic ring structure is not particularly limited as long as it has an isothiazolinone skeleton and an aromatic ring in its structure, but is, for example, a compound represented by the following formula (II): (In formula (II), Y is the same as in formula (I), and X ３ ~X ６ are each any one of a hydrogen atom, a halogen atom, a hydroxy group, a cyano group, an amino group, a carboxy group, an alkyl group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms. ３ ~X ６ may be the same or different.)

[0058] In formula (II), X ３ ~X ６ The halogen atom in formula (I) is １ and X ２ In formula (II), examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. In formula (II), examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, and the like.

[0059] In formula (II), Y and X ３ ~X ６ is preferably a hydrogen atom.

[0060] <<Specific Examples of Compounds Having an Isothiazolinone Structure>> Examples of compounds having an isothiazolinone structure (isothiazolinone compounds) include 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 2-ethyl-4-isothiazolin-3-one, 4,5-dichloro-2-cyclohexyl-4-isothiazolin-3-one, Examples of isothiazolinone compounds that do not have an aromatic ring structure include 1,2-benzisothiazolin-3-one, 5-chloro-2-ethyl-4-isothiazolin-3-one, and 5-chloro-2-t-octyl-4-isothiazolin-3-one; and isothiazolinone compounds that have an aromatic ring structure, such as 1,2-benzisothiazolin-3-one (sometimes simply referred to as "benzo-isothiazolin-3-one") and N-methyl-1,2-benzisothiazolin-3-one. These may be used alone or in combination of two or more. As an isothiazolinone compound that does not have an aromatic ring structure, 2-methyl-4-isothiazolin-3-one is preferred. As an isothiazolinone compound that has an aromatic ring structure, benzo-isothiazolin-3-one is preferred.

[0061] <<Content of Compound Having Isothiazolinone Structure>> In the composition of the present invention, the content of the isothiazolinone compound is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, and preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.2 parts by mass or less, relative to 100 parts by mass of the water-soluble polymer. If the content of the isothiazolinone compound relative to 100 parts by mass of the water-soluble polymer is equal to or greater than the above-mentioned lower limit, the wettability of the resulting slurry composition with the release substrate and the wettability of the resulting dielectric layer with the conductive paste can be effectively improved. On the other hand, if the content of the isothiazolinone compound relative to 100 parts by mass of the water-soluble polymer is equal to or less than the above-mentioned upper limit, the dispersion stability of the resulting slurry composition can be effectively improved.

[0062] In the composition of the present invention, the content of the isothiazolinone compound is preferably 0.00005 parts by mass or more, more preferably 0.00025 parts by mass or more, and even more preferably 0.005 parts by mass or more, and preferably 0.05 parts by mass or less, more preferably 0.025 parts by mass or less, and even more preferably 0.01 parts by mass or less, based on 100 parts by mass of the dielectric material. If the content of the isothiazolinone compound based on 100 parts by mass of the dielectric material is equal to or greater than the above-mentioned lower limit, the wettability of the resulting slurry composition with the release substrate and the wettability of the resulting dielectric layer with the conductive paste can be effectively improved. On the other hand, if the content of the isothiazolinone compound based on 100 parts by mass of the dielectric material is equal to or less than the above-mentioned upper limit, the dispersion stability of the resulting slurry composition can be effectively improved.

[0063] In the composition of the present invention, the content of the isothiazolinone compound is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, and preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.2 parts by mass or less, based on 100 parts by mass of the particulate polymer described below. If the content of the isothiazolinone compound based on 100 parts by mass of the particulate polymer is equal to or greater than the above-mentioned lower limit, the wettability of the resulting slurry composition with the release substrate and the wettability of the resulting dielectric layer with the conductive paste can be effectively improved. On the other hand, if the content of the isothiazolinone compound based on 100 parts by mass of the particulate polymer is equal to or less than the above-mentioned upper limit, the dispersion stability of the resulting slurry composition can be effectively improved.

[0064] <Particulate Polymer> The composition of the present invention preferably further contains a particulate polymer. If the composition further contains a particulate polymer, the dispersion stability of the resulting slurry composition can be improved.

[0065] Here, the particulate polymer is a component that can function as a binder, and it imparts adhesiveness to the dielectric layer formed using the slurry composition, and also holds the material contained in the dielectric layer (e.g., the dielectric material) so that it does not detach from the dielectric layer (i.e., suppresses powder falling). Note that the particulate polymer has a particulate shape in the composition of the present invention and in the slurry composition of the present invention described later, but in the dielectric layer, it may be present while maintaining its particulate shape or in any non-particulate shape.

[0066] 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.

[0067] The particulate polymer is not particularly limited, and any polymer such as a conjugated diene polymer or an acrylic polymer can be used.

[0068] <<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. The conjugated diene polymer may also 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"). Here, the other monomer unit B is a monomer unit different from the above-mentioned other monomer unit A.

[0069] 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.

[0070] [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 pentadiene, and substituted 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.

[0071] The content of the 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 the total amount of repeating units (total monomer units and total structural units) contained in the conjugated diene polymer is 100% by mass.

[0072] [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.

[0073] 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.

[0074] [Hydrophilic Group-Containing Structural Unit] In a conjugated diene polymer, the hydrophilic group-containing structural unit may be a structural unit that can be formed from a hydrophilic group-containing monomer, or 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 hydroxy 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 carboxy 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.

[0075] 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 8% 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.

[0076] [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.

[0077] 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.

[0078] [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 above-mentioned monomers that can form the conjugated diene polymer. 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.

[0079] 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.

[0080] 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 taken as 100 mass%.

[0081] <<Acrylic Polymer>> The acrylic polymer (ACL) is a polymer containing (meth)acrylic acid alkyl ester monomer units. The acrylic polymer may optionally contain hydrophilic group-containing structural units and cyano group-containing monomer units. The acrylic polymer may also contain monomer units other than the (meth)acrylic acid alkyl ester monomer units, the hydrophilic group-containing structural units, and the cyano group-containing monomer units (hereinafter, sometimes referred to as "other monomer units C"). Here, the other monomer units C are monomer units different from the above-mentioned other monomer units A and other monomer units B. Note that the acrylic polymer is typically a polymer containing 50% by mass or more of (meth)acrylic acid alkyl ester monomer units when the total amount of all repeating units (total monomer units and all structural units) contained in the acrylic polymer is taken as 100% by mass, and is different from the above-mentioned conjugated diene polymer.

[0082] [(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 to prepare 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.

[0083] 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.

[0084] [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 hydroxy 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.

[0085] 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 8% 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.

[0086] [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.

[0087] The content of the cyano group-containing monomer unit in the acrylic polymer is preferably 10% by mass or more, more preferably 15% by mass or more, and is preferably 45% by mass or less, more preferably 30% by mass or less, and even more preferably 25% 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.

[0088] [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 aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, and divinylbenzene; 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.

[0089] 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.

[0090] <<Volume Average Particle Diameter of Particulate Polymer>> The volume average particle diameter of the particulate polymer is preferably 10 nm or more, more preferably 20 nm or more, and is preferably 1000 nm or less, more preferably 800 nm or less, and even more preferably 500 nm or less. In this specification, the volume average particle diameter of the particulate polymer can be measured according to the method described in the examples.

[0091] <<Content of Particulate Polymer>> In the composition of the present invention, the content of the particulate polymer is preferably 0.1 parts by mass or more, and more preferably 1 part by mass or more, and is preferably 20 parts by mass or less, and more preferably 15 parts by mass or less, relative to 100 parts by mass of the dielectric material.

[0092] <<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, general polymerization solvents and additives such as emulsifiers, dispersants, polymerization initiators, and chain transfer agents that can be used in the polymerization may be used, and the amounts used may be the amounts generally used.

[0093] <Solvent> The optional solvent that can be contained in the composition of the present invention is not particularly limited, and both water and organic solvents can be used. Examples of organic solvents that can be used include aqueous solvents such as lower alcohols such as methanol, ethanol, and isopropanol, and non-aqueous solvents such as methylbenzene (toluene) and xylene. From the viewpoints of reducing environmental impact, safety, and availability, as well as the ability to efficiently dissolve the isothiazolinone compound and improve the preservative effect, water is preferred. When the solvent contains water, the proportion of water in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, even more preferably 99% by mass or more, and particularly preferably 100% by mass (i.e., the solvent contains only water), based on 100% by mass of the entire solvent.

[0094] <Other Component A> The 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.

[0095] (Slurry composition) The slurry composition of the present invention contains the above-mentioned composition of the present invention and a solvent. That is, the slurry composition of the present invention contains a water-soluble polymer, a compound having an isothiazolinone structure, a dielectric material having a perovskite structure, and a solvent, and may optionally contain a particulate polymer. Because the slurry composition of the present invention contains the composition of the present invention, it has excellent wettability and dispersion stability with the release substrate, and can impart excellent wettability with the conductive paste to the dielectric layer. Note that examples of the solvent contained in the slurry composition of the present invention include the same solvents as those described in the "Solvent" section above.

[0096] The slurry composition of the present invention may contain components other than the water-soluble polymer, the compound having an isothiazolinone structure, the dielectric material having a perovskite structure, the solvent, and the particulate polymer (hereinafter, these may be referred to as "other component B"). Examples of other component B that may be optionally contained in the slurry composition of the present invention include the same as the other component A described above.

[0097] Here, the solid content concentration of the slurry composition is preferably 30% by mass or more, more preferably 35% by mass or more, and is preferably 70% by mass or less, more preferably 65% ​​by mass or less.

[0098] In the slurry composition of the present invention, the content of the water-soluble polymer is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, based on 100 parts by mass of the dielectric material.

[0099] In the slurry composition of the present invention, the content of the isothiazolinone compound is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, and preferably 1.0 parts by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.2 parts by mass or less, relative to 100 parts by mass of the water-soluble polymer. If the content of the isothiazolinone compound relative to 100 parts by mass of the water-soluble polymer is equal to or greater than the above-mentioned lower limit, the wettability with the release substrate can be effectively improved, and the wettability of the resulting dielectric layer with the conductive paste can be effectively improved. On the other hand, if the content of the isothiazolinone compound relative to 100 parts by mass of the water-soluble polymer is equal to or less than the above-mentioned upper limit, the dispersion stability can be effectively improved.

[0100] In the slurry composition of the present invention, the content of the isothiazolinone compound is preferably 0.00005 parts by mass or more, more preferably 0.00025 parts by mass or more, and even more preferably 0.005 parts by mass or more, and preferably 0.05 parts by mass or less, more preferably 0.025 parts by mass or less, and even more preferably 0.01 parts by mass or less, based on 100 parts by mass of the dielectric material. If the content of the isothiazolinone compound is equal to or greater than the above-mentioned lower limit, the wettability with the release substrate can be effectively improved, and the wettability of the resulting dielectric layer with the conductive paste can be effectively improved. On the other hand, if the content of the isothiazolinone compound is equal to or less than the above-mentioned upper limit, based on 100 parts by mass of the dielectric material, the dispersion stability can be effectively improved.

[0101] In the slurry composition of the present invention, the content of the isothiazolinone compound is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, and is preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.2 parts by mass or less, based on 100 parts by mass of the particulate polymer. If the content of the isothiazolinone compound based on 100 parts by mass of the particulate polymer is equal to or greater than the above-mentioned lower limit, the wettability with the release substrate can be effectively improved, and the wettability with the conductive paste of the resulting dielectric layer can be effectively improved. On the other hand, if the content of the isothiazolinone compound based on 100 parts by mass of the particulate polymer is equal to or less than the above-mentioned upper limit, the dispersion stability can be effectively improved.

[0102] In the slurry composition of the present invention, the content of the optional particulate polymer 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.

[0103] The slurry composition of the present invention has excellent wettability and dispersion stability with a release substrate and can impart excellent wettability with a conductive paste to a dielectric layer, and therefore can be suitably used in multilayer ceramic capacitors. That is, the slurry composition of the present invention is preferably used for multilayer ceramic capacitors. Specifically, the slurry composition of the present invention is preferably used for producing a dielectric layer used in the production of a multilayer ceramic capacitor.

[0104] The above-mentioned slurry composition can be prepared by a known method by mixing the dielectric material having a perovskite structure, the water-soluble polymer, and the isothiazolinone compound (corresponding to the above-mentioned composition of the present invention), as well as the solvent, any particulate polymer, and other component B. 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.

[0105] (Dielectric Layer) The dielectric layer of the present invention comprises a dried film (hereinafter, sometimes simply referred to as "dried film") obtained by drying a coating film using the above-described slurry composition of the present invention. Here, the dried film of the dielectric layer of the present invention is made using the slurry composition of the present invention, which has excellent wettability with a release substrate and dispersion stability, and therefore has excellent film thickness uniformity. Furthermore, the dried film of the dielectric layer of the present invention is made using the slurry composition of the present invention, which can impart excellent wettability with a conductive paste to the dielectric layer, and therefore has excellent wettability with a conductive paste.

[0106] <Dried film obtained by drying a coated film> The dried film provided in the dielectric layer of the present invention is not particularly limited as long as it is made using the slurry composition of the present invention. Here, the dried film provided in the dielectric layer of the present invention is a dried film obtained by partially or completely removing the solvent in the coated film using the slurry composition. That is, the dried film provided in the dielectric layer of the present invention contains a water-soluble polymer, a compound having an isothiazolinone structure, and a dielectric material having a perovskite structure, and may optionally contain a solvent, a particulate polymer, and other components B.

[0107] In the dry film, the content of the dielectric material is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more, when all components in the dry film are 100% by mass, and is preferably 98% by mass or less, and more preferably 95% by mass or less.

[0108] In the dry film, the content of the water-soluble polymer is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, based on 100 parts by mass of the dielectric material.

[0109] In the dry film, the content of the isothiazolinone compound is preferably 0.001 part by mass or more, more preferably 0.005 part by mass or more, and even more preferably 0.01 part by mass or more, and is preferably 1.0 part by mass or less, more preferably 0.5 part by mass or less, and even more preferably 0.2 part by mass or less, relative to 100 parts by mass of the water-soluble polymer.

[0110] In the dried film, the content of the isothiazolinone compound is preferably 0.00005 parts by mass or more, more preferably 0.00025 parts by mass or more, and even more preferably 0.005 parts by mass or more, and is preferably 0.05 parts by mass or less, more preferably 0.025 parts by mass or less, and even more preferably 0.01 parts by mass or less, based on 100 parts by mass of the dielectric material.

[0111] In the dry film, the content of the isothiazolinone compound is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass or more, and even more preferably 0.01 parts by mass or more, and is preferably 1.0 part by mass or less, more preferably 0.5 parts by mass or less, and even more preferably 0.2 parts by mass or less, relative to 100 parts by mass of the particulate polymer described below.

[0112] In the dry film, the content of the optional particulate polymer 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.

[0113] The thickness of the dry film 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.

[0114] The method for producing the dried film is not particularly limited, and for example, the dried film can be produced by applying the slurry composition of the present invention onto a release substrate and drying the formed coating film.

[0115] Here, the release substrate used when producing the dry film (the release substrate onto which the slurry composition is applied) 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.

[0116] The surface of the release substrate on which the coating film is formed is preferably subjected to a surface treatment 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.

[0117] The thickness of the release substrate is not particularly limited, but is usually 20 μm or more and 100 μm or less.

[0118] 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).

[0119] 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.

[0120] <Internal Electrode Layer> The dielectric layer of the present invention may have a conductive film formed on a dried film as an internal electrode layer. That is, the dielectric layer of the present invention may be in the form of a dielectric layer with a conductive film. The conductive film can be formed by various printing methods such as screen printing, gravure printing, stamp printing, inkjet printing, and offset printing using a pattern formed by these methods; vacuum deposition for forming a metal vapor deposition film; etc. Here, when the conductive film is formed by a printing method, a conductive paste can be used. The conductive paste can be prepared by a conventionally known method, for example, by mixing a conductive material, a binder, an organic solvent, and optionally a dielectric material, other component C, etc.

[0121] The conductive material contained in the conductive paste is not particularly limited, and may be, for example, one or more powders selected from Ni, Pd, Pt, Au, Ag, Cu, and alloys thereof. Among these, Ni 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 may be used. The Ni content in the Ni alloy is typically 50% by mass or more, preferably 80% by mass or more. Furthermore, the Ni powder may contain several hundred ppm of S (sulfur) to suppress rapid gas generation due to partial thermal decomposition of the binder during binder removal processing.

[0122] The average particle size 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, more preferably 0.5 μm or less. In this specification, the average particle size of the conductive material is a particle size calculated from the specific surface area obtained based on the BET method, unless otherwise specified. For example, the average particle size of Ni powder can be calculated using the following formula (1): Average particle size = 6 / S.A × ρ (1) (ρ = 8.9 (true density of Ni), S.A = BET specific surface area of ​​Ni powder)

[0123] The binder contained in the conductive paste is a component that holds the material (e.g., conductive material) contained in the internal electrode layer so that it does not detach from the internal electrode layer during the production of the multilayer ceramic capacitor described below.

[0124] Here, the same polymer as that explained in the above section "Water-soluble polymer" can be used as the binder. As the binder, polyvinyl acetal obtained by acetalizing a portion of the hydroxy groups of a water-soluble polymer having hydroxy groups (for example, the water-soluble polymer obtained by the above method (2)) is preferred, and polyvinyl butyral obtained by acetalizing the hydroxy groups of a water-soluble polymer with butyraldehyde is more preferred.

[0125] The organic solvent contained in the conductive paste is not particularly limited, but for example, a terpene-based solvent such as terpineol or dihydroterpineol can be used.

[0126] Examples of the dielectric material that can be optionally contained in the conductive paste include the same dielectric materials as those described above in the section "Dielectric material having a perovskite structure."

[0127] Other components C that may be optionally contained in the conductive paste include a dispersant, a plasticizer, and the like.

[0128] (Multilayer ceramic capacitor) The multilayer ceramic capacitor of the present invention includes a dielectric using the dielectric layer of the present invention described above. The multilayer ceramic capacitor of the present invention typically includes internal electrodes formed from the internal electrode layers described above and in contact with the dielectric. Here, the multilayer ceramic capacitor of the present invention includes a dielectric using the dielectric layer of the present invention, which has excellent film thickness uniformity, and therefore performance variations are suppressed. Furthermore, the multilayer ceramic capacitor of the present invention includes a dielectric using the dielectric layer of the present invention, which has excellent wettability with the conductive paste, and therefore has high adhesion between the dielectric and the internal electrode, resulting in excellent performance.

[0129] The dielectric included in the multilayer ceramic capacitor of the present invention is not particularly limited as long as it uses the dielectric layers of the present invention. For example, the multilayer ceramic capacitor of the present invention may be a sintered product (a sintered product) that includes a dielectric and internal electrodes obtained by sintering a laminate in which the dielectric layers of the present invention are stacked. Note that, while an example of the multilayer ceramic capacitor of the present invention will be described below with reference to FIG. 1, 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 according to the present invention. The multilayer ceramic capacitor 10 shown in FIG. 1 includes layered dielectrics 11 and layered internal electrodes 12 that are alternately stacked, and a pair of external electrodes 13 on the outer sides of the dielectrics 11 and the internal electrodes 12. One of the pair of internal electrodes 12 adjacent to each other along the stacking direction, sandwiching the dielectric 11 therebetween, is electrically connected to one of the pair of external electrodes 13 within the multilayer ceramic capacitor 10, and the other of the pair of internal electrodes 12 adjacent to each other along the stacking direction, sandwiching the dielectric 11 therebetween, is electrically connected to the other of the pair of external electrodes 13 within the multilayer ceramic capacitor 10. This results in a structure in which multiple capacitor elements are electrically connected in parallel between the pair of external electrodes 13. Note that the interface between the dielectric layers of the present invention that may be formed when the dielectric layers are stacked is not shown in FIG. 1 because the dielectric layers may be integrated and disappear during sintering.

[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 stacking a plurality of dielectric layers of the present invention, each having internal electrode layers (conductive films) that can serve as internal electrodes, so that the dielectric layers and the internal electrode layers alternate, heat-pressing the stack to form a laminate, thermally decomposing and removing binder components and the like contained in the laminate (degreasing treatment), sintering the stack, and forming external electrodes on 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 content of the binder component in the laminate 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 ２ The 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 specifically described 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 weight-average molecular weight of the water-soluble polymer, the glass transition temperature of the particulate polymer, the volume-average particle size of the particulate polymer, the antiseptic effect, dispersion stability, wettability with a conductive paste, and wettability with a release substrate were measured and evaluated according to the following procedures.

[0136] <Method for measuring the weight-average molecular weight of a water-soluble polymer> The weight-average molecular weight of a water-soluble polymer was measured by gel permeation chromatography (GPC). Specifically, the water-soluble polymer was first added to approximately 5 mL of eluent so that the solid concentration was approximately 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.)

[0137] <Method for measuring glass transition temperature of particulate polymer> Aqueous dispersions containing the particulate polymers of the Examples and Comparative Examples were dried for 3 days in an environment of 50% humidity and 25°C to obtain a film having a thickness of 1.0 mm. This film was dried for 10 hours in a vacuum dryer at 60°C. Thereafter, the glass transition temperature (°C) of the dried film was measured as a sample in accordance with JIS K7121 using a differential scanning calorimeter (DSC6220, manufactured by SII NanoTechnology Inc.) under conditions of a measurement temperature of -100°C to 180°C and a temperature rise rate of 5°C / min.

[0138] <Method for measuring volume average particle diameter of particulate polymer> The volume average particle diameter of the particulate polymer in the examples and comparative examples was measured by a laser diffraction method. Specifically, an aqueous dispersion containing the prepared particulate polymer (adjusted to a solid content concentration of 0.1%) was used as a sample. Then, in the particle size distribution (volume basis) measured using a laser diffraction particle size distribution analyzer (manufactured by Beckman Coulter, Inc., product name "LS-230"), the particle diameter D50 at which the cumulative volume calculated from the smallest diameter side reached 50% was taken as the volume average particle diameter.

[0139] <Wettability with Release Substrate> 1 μL of the slurry compositions produced in the Examples and Comparative Examples was dropped onto a PET substrate, which was a release substrate, and the contact angle (°) formed between the PET substrate and the droplet of the slurry composition after 10 seconds was measured, and the wettability with the release substrate was evaluated according to the following criteria. A smaller contact angle means better wettability with the release substrate. A: Contact angle of 30° or less B: Contact angle of more than 30° and less than 50° C: Contact angle of more than 50°

[0140] <Dispersion Stability> The viscosity η0 of the slurry compositions produced in the examples and comparative examples was measured at 25°C and 60 rpm using a Brookfield viscometer. The slurry compositions were then left to stand at 25°C for 7 days, and the viscosity η1 was measured again in the same manner as above. Using the measured viscosities η0 and η1, the viscosity change rate α was calculated according to the following formula (2): Viscosity change rate α (%) = (η1 / η0) × 100 (2) The dispersion stability was then evaluated according to the following criteria: The viscosity change rate α is 100% or more, and the closer the viscosity change rate α is to 100%, the less the viscosity change of the slurry composition over time and the more excellent the dispersion stability. A: Viscosity change rate α is 100% or more and less than 150% B: Viscosity change rate α is 150% or more and less than 200% C: Viscosity change rate α is 200% or more

[0141] <Wettability with Conductive Paste> 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 the conductive material, 25 parts of barium titanate ("BT-01" manufactured by Sakai Chemical Industry Co., Ltd.) as the dielectric material, 2 parts of polyvinyl butyral (BL-2H manufactured by Sekisui Chemical Co., Ltd.) as the binder, and 65 parts of terpineol as the organic solvent were mixed to prepare a conductive paste (solid concentration 66%). Next, the evaluation slurry composition was applied to a polyethylene terephthalate (PET) substrate to form a 5 μm thick coating film, and the coating film was dried at 100 ° C. for 10 minutes. Next, 1 μL of conductive paste was dropped onto the dried film obtained by drying the obtained coating film, and the contact angle (°) formed between the dried film and the droplet of conductive paste after 10 seconds was measured to evaluate the wettability with the conductive paste 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°

[0142] <Preservative Effect> For the slurry compositions produced in the Examples and Comparative Examples, the viscosity η0' of the slurry composition was measured, and the composition was stored at 60°C for 180 days. The viscosity η1' of the slurry composition was measured, and η1' / η0'×100(%) was calculated to calculate the viscosity change rate β. If the viscosity change rate β is 100% or more and less than 105%, the coating properties of the slurry are not impaired after long-term storage, which means that the preservative effect is excellent. The preservative effect suppresses decomposition of components in the slurry, making it easier to ensure coating stability during coating. A: The viscosity change rate β is 100% or more and less than 105% B: The viscosity change rate β is 105% or more and less than 110%, or 90% or more and less than 100% C: The viscosity change rate β is 110% or more or less than 90%

[0143] Example 1 Preparation 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. 0.08 parts of benzo-isothiazolin-3-one (Naviside P-40, manufactured by Katsuyama Chemical Co., Ltd.) was added as a preservative to obtain an aqueous solution of water-soluble polymer A (acrylic polymer) (solids concentration 10%). The weight-average molecular weight of the water-soluble polymer A was measured using the resulting aqueous solution. The results are shown in Table 1.

[0144] <Preparation of Particulate Polymer> 74 parts of ion-exchanged water, 0.2 parts of sodium dodecyl diphenyl ether sulfonate, 1.0 parts of ammonium persulfate as a polymerization initiator, and 9.7 parts of ion-exchanged water were added to a 5 MPa pressure vessel A equipped with a stirrer, and the mixture was heated to 70° C. and stirred for 30 minutes. Next, 82.0 parts of n-butyl acrylate as a (meth)acrylic acid alkyl ester monomer, 6.0 parts of acrylonitrile as a cyano group-containing monomer, 2.0 parts of methacrylic acid as a hydrophilic group-containing monomer, 10.0 parts of glycidyl methacrylate as a crosslinkable monomer, 0.8 parts of sodium dodecyl diphenyl ether sulfonate as an emulsifier, and 74 parts of ion-exchanged water were added to a 5 MPa pressure vessel B equipped with a stirrer, and the mixture was stirred to prepare an emulsion. The prepared emulsion was added successively from polymerization vessel B to polymerization vessel A over approximately 200 minutes, followed by stirring for approximately 180 minutes. When the monomer conversion reached 97% or more, the mixture was cooled to terminate the reaction. The pH was then adjusted with a 4% aqueous NaOH solution, and unreacted monomer was removed by heating and vacuum distillation to obtain an aqueous dispersion of an acrylic polymer (solid concentration: 40%). The pH of the resulting aqueous dispersion was 8.0. The glass transition temperature and the properties of the particulate polymer were measured using the resulting aqueous dispersion. The results are shown in Table 1.

[0145] <Preparation of Slurry Composition> 100 parts of barium titanate (BT-01, manufactured by Sakai Chemical Industry Co., Ltd.) having an average particle size (d50) of 0.1 μm as the dielectric material, 5 parts in terms of solids of the water-soluble polymer A prepared above (50 parts as an aqueous solution), and 20 parts of water as a solvent were stirred together with 100 parts of zirconia beads (manufactured by Nikkato Corporation) having a particle size of 0.1 mm as mixing beads using a bead mill (RMB-01, manufactured by Imex Co., Ltd.) at 500 rpm for 2 hours. Thereafter, an additional 44 parts of water was added, and the mixture was stirred at 500 rpm for 1 hour. The zirconia beads were filtered off, and a dispersion of barium titanate was prepared. To 190 parts of this dispersion (100 parts of barium titanate), 5 parts of particulate polymer (12.5 parts as aqueous dispersion) was added, and then the mixture was stirred at 1000 rpm for 3 minutes using a planetary centrifugal mixer to prepare a slurry composition with a solids concentration of 56%. The obtained slurry composition was used to evaluate the antiseptic effect, wettability with release substrates, and dispersion stability. The results are shown in Table 1.

[0146] <Preparation of Dielectric Layer> The slurry composition obtained above was applied to a release-treated film (PET38AL-5, manufactured by Lintec Corporation) having a width of 100 mm and a length of 100 mm using a gravure coater so that the thickness of the green sheet (dry film) after drying would be approximately 1.0 μm, and the coating was dried in an oven at 100° C. for 5 minutes to obtain a dielectric layer on the release substrate (ceramic green sheet method).

[0147] (Example 2) In the preparation of water-soluble polymer A, the amount of benzo-isothiazolin-3-one added was changed from 0.08 part to 0.008 part, except that the procedures, measurements, and evaluations were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0148] (Example 3) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in the preparation of water-soluble polymer A, the amount of benzo-isothiazolin-3-one added was changed from 0.08 parts to 0.8 parts, and a slurry composition having a solid content concentration of 54% was obtained. The results are shown in Table 1.

[0149] Example 4 Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that in the preparation of the water-soluble polymer, the amount of benzo-isothiazolin-3-one was changed from 0.08 parts to 0.08 parts of 2-methyl-4-isothiazolin-3-one, and a slurry composition having a solids concentration of 54% was obtained. The results are shown in Table 1.

[0150] (Example 5) Various operations, measurements, and evaluations were carried out in the same manner as in Example 1, except that an aqueous solution of water-soluble polymer B prepared by the following method was used instead of the aqueous solution of water-soluble polymer A, and a slurry composition having a solids concentration of 58% was obtained. The results are shown in Table 1.

[0151] <Preparation of Water-Soluble Polymer B> Polyvinyl alcohol (Denka Poval (registered trademark) B-33, manufactured by Denka Co., Ltd.) was prepared as the water-soluble polymer B. 0.08 parts of benzo-isothiazolin-3-one (Naviside P-40, manufactured by Katsuyama Chemical Co., Ltd.) serving as a preservative was added to 100 parts of polyvinyl alcohol, and ion-exchanged water was further added to give a solids concentration of 10%, thereby obtaining an aqueous solution of water-soluble polymer B. The weight-average molecular weight of the water-soluble polymer obtained was measured using the resulting aqueous solution. The results are shown in Table 1.

[0152] (Example 6) Various operations, measurements, and evaluations were carried out in the same manner as in Example 5, except that a particulate polymer was not added and a slurry composition having a solid content concentration of 57% was obtained. The results are shown in Table 1.

[0153] Comparative Example 1 Various operations, measurements, and evaluations were carried out in the same manner as in Example 5, except that in the preparation of water-soluble polymer B, 0.08 parts of benzo-isothiazolin-3-one was changed to 0.08 parts of parahydroxybenzoic acid ester (a compound not having an isothiazolinone structure), and a slurry composition having a solids concentration of 55% was obtained. The results are shown in Table 1.

[0154] Comparative Example 2 Various operations, measurements, and evaluations were carried out in the same manner as in Example 5, except that benzo-isothiazolin-3-one was not added in the preparation of water-soluble polymer B, and a slurry composition having a solid content of 56% was obtained. The results are shown in Table 1.

[0155]

[0156] According to the present invention, a composition can be provided that can impart excellent wettability and dispersion stability with a release substrate to a slurry composition and excellent wettability with a conductive paste to a dielectric layer. Furthermore, according to the present invention, a slurry composition containing the above composition can be provided. Furthermore, according to the present invention, a dielectric layer can be provided that includes a dried film formed by drying a coating film using the above slurry composition. Furthermore, according to the present invention, a multilayer ceramic capacitor can be provided that includes a dielectric using the above dielectric layer.

[0157] 10: Multilayer ceramic capacitor 11: Dielectric 12: Internal electrode 13: External electrode

Claims

1. A composition containing a water-soluble polymer, a compound having an isothiazolinone structure, and a dielectric material having a perovskite structure.

2. The composition of claim 1, wherein said water-soluble polymer is an acrylic polymer.

3. The composition of claim 1, wherein the water-soluble polymer has a carboxy group.

4. The composition described in claim 1, wherein the content of the compound having an isothiazolinone structure is 0.001 parts by mass or more and 1.0 parts by mass or less, based on 100 parts by mass of the water-soluble polymer.

5. The composition according to claim 1, wherein the compound having an isothiazolinone structure further has an aromatic ring structure.

6. The composition of claim 1 further comprising a particulate polymer.

7. A slurry composition comprising the composition according to any one of claims 1 to 6 and a solvent.

8. The slurry composition according to claim 7, which is for use in a multilayer ceramic capacitor.

9. A dielectric layer comprising a dried film formed by drying a coating film made from the slurry composition according to claim 8.

10. A multilayer ceramic capacitor comprising a dielectric using the dielectric layer according to claim 9.

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