JP2020080266A - Paste composition for internal electrode of multilayer ceramic component, and multilayer ceramic component - Google Patents

Abstract

To provide a paste composition for use in an internal electrode of a multilayer ceramic, which inhibits nonuniformity of fine particle distribution in a coating formed.SOLUTION: The paste composition comprises a conductive powder, a dielectric powder, a dispersant, and a binder resin. The conductive powder has an average particle diameter, calculated from a specific surface area, of 10 nm to 150 nm inclusive. The dielectric powder has an average particle diameter, calculated from a specific surface area, of 10 nm to 100 nm inclusive. The dispersant is an alkylamide type dispersant selected from at least one of the general formulas in the figure.SELECTED DRAWING: None

Description

  The present invention relates to an internal electrode paste composition used for forming an internal electrode layer of a laminated ceramic component such as a laminated ceramic capacitor and a laminated piezoelectric element, and an internal electrode formed using the internal electrode paste composition. A laminated ceramic component comprising layers.

  A multi-layer ceramic capacitor (MLCC) is formed by stacking a large number of dielectric layers and internal electrode layers. Since the MLCC is small and can realize a large capacitance, it has been widely used in recent years. Recently, MLCCs are required to be further downsized and have higher capacity. Therefore, when manufacturing MLCCs, further thinning (thinning) of dielectric layers and internal electrode layers, and Higher stacking of each of these layers is important.

As a method of manufacturing an MLCC, typically, a green sheet that serves as a dielectric layer and an electrode pattern that serves as an internal electrode layer are alternately laminated to form a laminated body (green sheet laminated body). The process of baking is mentioned. A paste composition containing, for example, nickel (Ni) powder as a conductive powder is used for the internal electrode layers, and a paste composition containing, for example, barium titanate (BaTiO ₃ ) powder as a dielectric layer is used for the ceramic layers. Things are used. A laminate in which a dry coating film (electrode pattern) to be an internal electrode layer and a dry coating film (green sheet) to be a dielectric layer are laminated by alternately coating or printing these paste compositions and then drying. Is obtained.

  Here, in the laminated body before firing, it becomes necessary to improve the smoothness of the internal electrode layers when the layer thickness becomes thin. Specifically, for example, in the dry coating film to be the internal electrode layer, there remains an aggregate that is a secondary aggregation of the conductive powder and is larger than the thickness of the dry coating film (internal electrode layer and dielectric layer). Suppose In this case, the agglomerates may penetrate through the adjacent dielectric layers and come into contact with other internal electrode layers. As a result, a connection failure or an insulation failure may occur in the obtained MLCC, and the MLCC cannot realize the characteristics as designed.

  Therefore, good smoothness is required for the surface (electrode surface) of the dry coating film that becomes the internal electrode layer. In order to improve the high smoothness of the internal electrode layer, conventionally, the conductive powder used for the internal electrode layer and the dielectric powder used for the dielectric layer have a particle size (particle size) of a unit of micron. A method of using particles (about several μm) (micron particles) or particles on a submicron basis (about 100 nm of less than 1 μm) (submicron particles) is known. Recently, ultrafine particles having an average particle diameter (average particle diameter) of 150 nm or less are used to achieve higher smoothness. However, the specific surface area of such ultrafine particles is significantly larger than that of micron particles or submicron particles. Therefore, in producing the paste composition, there is a possibility that the conventional dispersion method cannot realize sufficient dispersibility of the ultrafine particles.

  Therefore, for example, in Patent Document 1, metal nickel fine particles coated with a primary amine are prepared, and at least a part of the primary amine is treated with a non-aqueous polymer dispersant having a secondary or tertiary amino group. A method of manufacturing a conductive paste to be replaced is disclosed. According to this manufacturing method, it is described that the obtained conductive paste contains fine nickel fine particles of 150 nm or less in a highly dispersed state. It is also described that the use of this conductive paste prevents unevenness from being generated on the surface of the internal electrode layer, and facilitates thinning and multilayering of the internal electrode layer in the MLCC.

  By the way, in the MLCC, in the paste composition for the internal electrode layer, a method of adding a dielectric powder of several tens nm level as a co-material together with the conductive powder is known in order to suppress delamination from the dielectric layer. ing. For example, when nickel powder is used for the internal electrode layer and barium titanate powder is used for the dielectric layer, the nickel paste composition for the internal electrode layer is used as a co-material with nickel powder at a level of several tens nm. Barium titanate powder is added.

  Therefore, in the paste composition for the internal electrode layer, sufficient dispersibility is required for both the conductive powder and the dielectric powder of the common material in order to achieve good smoothness. The sufficient dispersibility here means, however, that in the paste composition, a plurality of kinds of powders (different kinds of powders) of different materials such as metal powders such as nickel and oxide powders such as barium titanate having different surface states are used in the paste composition. It is required to disperse satisfactorily and to a degree where the distribution of these different kinds of powder can be regarded as substantially uniform without being substantially biased.

  For example, Patent Document 2 discloses a conductive paste in which the content of the resin binder is reduced to 5% by mass or less by using a polyalkyleneimine having a predetermined number average molecular weight together with the resin binder. In this cited document 2, it is described that a ceramic powder such as barium titanate or titanium oxide is used as a co-material in a conductive paste for an internal electrode of an MLCC. It is described that, together with 18 μm (180 nm) nickel powder, barium titanate powder having an average particle diameter of 50 nm is used as a co-material.

  However, in Patent Document 2, there is no specific reference to the effect of addition of the co-material, and it is preferable to use ethyl cellulose-based resin as the resin binder in order to suppress irregularities on the surface of the internal electrode layer. However, in order to suppress delamination, it is preferable to use a butyral meter resin as the resin binder.

  Although the MLCC is a type of laminated ceramic component, a laminated piezoelectric element is an example of the laminated ceramic component that is attempted to be thinned and highly laminated like the MLCC. Examples of the laminated piezoelectric element include a laminated piezoelectric actuator or a pressure sensor. Also in such a laminated piezoelectric element, as in the case of the MLCC, as the paste composition for the internal electrode layer, a conductive powder to which a dielectric powder as a common material is added is used. Therefore, also in the laminated piezoelectric element, sufficient dispersibility between different kinds of powders is required as in the MLCC.

JP, 2014-029845, A JP, 2008-092849, A

  As described above, in the paste composition for the internal electrode layer of the MLCC, different kinds of powders having different surface states, that is, conductive powders such as metal powders and dielectric powders such as ceramic powders that are co-materials are made to coexist. It is necessary to satisfactorily disperse (co-disperse) in each state (coexistence system). However, it is difficult for the conventional technique to realize good covariance in such a coexisting system.

  As described above, it is difficult to satisfactorily disperse fine particles of several tens of nm level to the primary particles by the conventional general dispersion method.

  Further, for example, the method disclosed in Patent Document 1 describes that, for a paste composition containing only nickel powder, the nickel powder can be highly dispersed. However, when the dielectric powder is added as the co-material as described above, it is difficult to disperse the dielectric powder well together with the nickel powder, and it is considered that good smoothness cannot be realized in the dry coating film. Furthermore, if the dielectric powder does not disperse well and aggregates, a portion of the dry coating film having a high concentration of nickel powder or dielectric powder may occur, that is, the distribution of these powders may become non-uniform. is there.

  Further, in the technique disclosed in Patent Document 2, a paste composition containing nickel powder and barium titanate powder as a common material is disclosed in Examples. However, as described above, in this document, a specific one is selected as the binder resin in order to realize good smoothness of the coating film or suppression of delamination, and the viscosity of the paste composition is also evaluated in the examples. Only. In the first place, Patent Document 2 has a problem of reducing the content of the resin binder and suppressing the decrease of the paste viscosity, and there is no study on the dispersibility or distribution uniformity of different powders.

  The present invention has been made to solve such a problem, and is used for an internal electrode of a laminated ceramic component, and in a paste composition containing a plurality of types of fine particles having a particle diameter of 150 nm or less, the fine particles are An object of the present invention is to provide a paste composition which can be well dispersed and can effectively suppress uneven distribution of fine particles when a coating film is formed.

  The paste composition for internal electrodes according to the present invention is used for forming an internal electrode layer of a laminated ceramic component in order to solve the above-mentioned problems, and includes (A) conductive powder, (B) dielectric powder, and (C). ) A dispersant and (D) a binder resin are contained, and the (A) conductive powder has an average particle diameter calculated from its specific surface area within a range of 10 nm to 150 nm, and the (B) dielectric powder. Has an average particle size calculated from its specific surface area of 10 nm or more and 100 nm or less, and the (C) dispersant is 1 selected from at least one of the following general formula (1) and general formula (2). Or two or more alkylamide type dispersants

(However, R ¹ in the general formula (1) is an alkylene group having 2 to 4 carbon atoms, R ² in the general formula (2) is an alkyl group having 8 to 18 carbon atoms, and R ³ is a carbon number. Is an alkylene group of 8 to 18, n in the general formula (1) or (2) is an integer of 1 or more and 100 or less, and X is a substituent represented by the following general formula (3) or the following general formula (4). The base,

R ⁴ in the general formula (3) is an alkyl group having 8 to 18 carbon atoms, R ⁵ in the general formula (4) is an alkylene group having 2 to 4 carbon atoms, and R ⁶ and R ⁷ are each independently. And is an alkyl group having 1 to 3 carbon atoms. )
Is a configuration.

  According to the above configuration, the internal electrode paste composition contains (A) the conductive powder and (B) the dielectric powder as the co-material, which comprises the (A) conductive powder and the (B) dielectric powder. In all cases, when the average particle size is ultrafine particles of 150 nm or less, the alkylamide type dispersant represented by the general formula (1) or (2) is used as the (C) dispersant. As a result, not only can the ultrafine particles be well dispersed in the internal electrode paste composition, but also (A) conductive powder and (B) dielectric powder, which are different types of powders of different materials and different surface states (different types). Powder) can be well dispersed in the internal electrode paste composition. Moreover, in the dry coating film formed by this internal electrode paste composition, the distribution of these different powders can be distributed to such an extent that they can be regarded as substantially uniform without being substantially biased.

  In the internal electrode paste composition having the above structure, the alkylamide type dispersant (C) as the dispersant may have a weight average molecular weight of 700 or more and 5000 or less.

  In addition, in the internal electrode paste composition having the above-mentioned configuration, the amount of the (C) dispersant added is 100 parts by mass of the total amount of the (A) conductive powder and the (B) dielectric powder. The composition may be in the range of 0.5 parts by mass or more and 7.0 parts by mass or less.

  Further, in the internal electrode paste composition having the above configuration, the (A) conductive powder is at least selected from the group consisting of silver (Ag), palladium (Pd), platinum (Pt), and nickel (Ni). The constitution may be a metal powder containing one kind.

  Further, in the internal electrode paste composition having the above structure, the (B) dielectric powder may be a powder of barium titanate or lead zirconate titanate (PZT).

  Further, in the internal electrode paste composition having the above configuration, the content of the (A) conductive powder is 30% by mass or more and 80% by mass when the total mass of the internal electrode paste composition is 100% by mass. The constitution may be within the range of not more than mass %.

  Further, in the internal electrode paste composition having the above structure, the content of the (B) dielectric powder is 1% by mass or more and 10% by mass when the total mass of the internal electrode paste composition is 100% by mass. The constitution may be within the range of not more than mass %.

  Further, the multilayer ceramic component according to the present invention may have a structure in which an internal electrode layer formed of the internal electrode paste composition having the above configuration and a dielectric layer are laminated. Examples of such a monolithic ceramic component may include a monolithic ceramic capacitor or a monolithic piezoelectric element.

  According to the present invention, with the above configuration, in a paste composition used for an internal electrode of a laminated ceramic component and containing a plurality of fine particles having a particle diameter of 150 nm or less, the fine particles are well dispersed and a coating film is formed. In this case, it is possible to effectively suppress the occurrence of uneven distribution in the distribution of the respective fine particles.

  The paste composition according to the present disclosure is used for forming an internal electrode layer of a laminated ceramic component, and contains (A) conductive powder, (B) dielectric powder, (C) dispersant, and (D) binder resin. To do. Among these components, the (A) conductive powder has an average particle size calculated from its specific surface area within a range of 10 nm to 150 nm, and the (B) dielectric powder has an average particle size calculated from its specific surface area. It is in the range of 10 nm or more and 100 nm or less. That is, both the conductive powder (A) and the dielectric powder (B) are ultrafine particles having an average particle diameter of 150 nm or less.

  Furthermore, in the internal electrode paste composition according to the present disclosure, the (C) dispersant is one or more alkylamides selected from at least one of the general formula (1) and the general formula (2) described below. It is a type dispersant. This makes it possible to favorably disperse a plurality of types of ultrafine particles and to effectively prevent uneven distribution of the respective fine particles when the coating film is formed. Hereinafter, a representative example of a representative embodiment of the present invention will be specifically described.

[(A) Conductive powder]
The conductive powder (A) used in the paste composition for internal electrodes according to the present disclosure is not particularly limited as long as it is a powder or particles having conductivity, but as described above, the average particle diameter calculated from the specific surface area ( The average particle size) is in the range of 10 nm or more and 150 nm or less. As a preferable average particle diameter, the upper limit is 130 nm or less, and more preferably the upper limit is 100 nm or less.

  (A) Even if the average particle diameter of the conductive powder exceeds 150 nm, it is possible to produce a laminated ceramic component using the internal electrode paste composition according to the present disclosure, but the smoothness of the dry coating film is It becomes difficult to reduce the thickness of the internal electrode layer. In particular, when particles having an average particle diameter of more than 150 nm (coarse particles, etc.) are present, both the arithmetic average roughness Ra and the maximum average roughness Rz of the dry coating film, which are the criteria for smoothness described later, may be significantly deteriorated. There is.

  On the other hand, the fine powder (nanoparticles) (A) having an average particle diameter of the conductive powder of less than 10 nm has very strong cohesiveness and is difficult to disperse to the level of primary particles. Therefore, even if a fine powder dispersion slurry is prepared in the process of manufacturing the paste composition, the dispersion state becomes unstable and precipitation or the like is likely to occur. Further, when such fine powder is used, eventually aggregates (coarse particles) having a size of more than 150 nm tend to be generated, and the smoothness of the dry coating film is deteriorated (arithmetic mean roughness Ra≦20 nm and maximum mean roughness Rz described later). ≦200 nm cannot be satisfied).

In the present disclosure, the method of calculating the average particle diameter of the (A) conductive powder and the (B) dielectric powder is not particularly limited, but from the specific surface area of the (A) conductive powder or the (B) dielectric powder, The calculation method based on the formula is adopted.
d=6/(ρ·S)×1000
In the above equation, d is the average particle diameter (nm) of the target ultrafine particles ((A) conductive powder or (B) dielectric powder), and S is the specific surface area (m ² of the target ultrafine particles. /G), and ρ is the density (g/cm ³ ) of the ultrafine particles of interest.

  Further, the specific surface areas of the conductive powder (A) and the dielectric powder (B) are not particularly limited, but the BET specific surface area may be used as illustrated in Examples described later. The method for measuring the BET specific surface area is not particularly limited, but in the present disclosure, monosorb (manufactured by Counter Chrome (Quanta Chrome)) is used and evaluated by the BET one-point method by nitrogen adsorption.

  Here, in general, fine particles having a particle diameter of 100 nm or less are referred to as “ultrafine particles”, and fine particles having a particle diameter of 10 nm or less are referred to as “nanoparticles”. Has a lower limit of 1 nm. Therefore, in a general definition, "ultrafine particles" include "nanoparticles". Further, generally, fine particles having a particle diameter of 1 μm (1000 nm) or less or less than 100 nm or more are referred to as “submicron particles”, and when simply referred to as “fine particles”, particles in a wide range of 100 nm to 100 μm. Is said to be.

  In the present disclosure, as described above, the conductive powder (A) has an average particle size calculated from the specific surface area of 150 nm or less, and the dielectric powder (B) has an average particle size calculated from the specific surface area of 100 nm or less. Therefore, it can be said that all are fine particles having an average particle diameter of 150 nm or less. Therefore, in the present disclosure, fine particles having an average particle diameter of 150 nm or less are referred to as “ultrafine particles” for convenience. Therefore, "ultrafine particles" in the present disclosure include a part of the general definition of "submicron particles" (or "fine particles") as well as the general definition of "ultrafine particles". In addition, in the present disclosure, since both (A) the conductive powder and (B) the dielectric powder have an average particle diameter of 10 nm or more, “nanoparticles” having an average particle diameter of less than 10 nm are not included. Therefore, unlike the general definition, "ultrafine particles" in the present disclosure do not include "nanoparticles".

  The specific material of the conductive powder (A) is not particularly limited as long as it can exhibit suitable conductivity as the internal electrode layer of the laminated ceramic component, but metal powder is usually used. Specific metal powders include, for example, those containing at least one selected from the group consisting of silver (Ag), palladium (Pd), platinum (Pt), and nickel (Ni). That is, the metal powder used as the (A) conductive powder may be a powder composed of a single type of metal, such as silver powder, palladium powder, platinum powder, nickel powder, or the like. It may be an alloy powder or a coprecipitated powder containing at least a metal selected from the above group, such as a silver/palladium alloy powder. In the case of alloy powder or coprecipitated powder, the ratio of each metal component is not particularly limited.

  When the conductive powder (A) is an alloy powder, the metal used other than the above group is not particularly limited. Although it may be an alloy of the metals forming the group, such as an alloy powder of silver/palladium, it is an alloy of at least one metal of the group and one or more metals other than the group. It may be.

  For example, when forming an internal electrode layer of a multilayer ceramic capacitor (MLCC), nickel powder is often used as the conductive powder (A). When the nickel powder is not a powder composed of nickel alone but a nickel alloy powder containing nickel as a main component, examples of metals other than nickel include manganese (Mn), chromium (Cr), and cobalt ( At least one selected from the group consisting of Co), aluminum (Al), iron (Fe), copper (Cu), zinc (Zn), silver (Ag), gold (Au), platinum (Pt), and palladium (Pd). One can be mentioned. Of this group, silver, platinum, and palladium are included in the group, but other metals are metals that are not included in the group.

  Moreover, only one type of metal powder may be used, or two or more types of metal powder may be appropriately combined and used. When using a plurality of types of metal powder, the mixing ratio is not particularly limited. Moreover, you may use together electroconductive powder other than metal powder. Further, the method for producing the conductive powder is not particularly limited, and examples thereof include a wet reduction method, a CVD method, a vapor phase reduction method such as a PVD method, and the like, but any method capable of producing particles within a range of 10 nm to 150 nm can be used. Any method can be used.

[(B) Dielectric powder]
The (B) dielectric powder used in the internal electrode paste composition according to the present disclosure is a generally manufactured dielectric material powder, and has an average particle diameter calculated from the specific surface area as described above. There is no particular limitation as long as it is in the range of 10 to 100 nm. That is, the (B) dielectric powder may be "ultrafine particles" that do not include the general definition of "nanoparticles", similar to the (A) conductive powder described above.

  (B) Even if the average particle diameter of the dielectric powder exceeds 100 nm, it is possible to manufacture a laminated ceramic component using the internal electrode paste composition according to the present disclosure, but the smoothness of the dry coating film is It becomes difficult to reduce the thickness of the internal electrode layer. In particular, when particles (coarse particles, etc.) having an average particle size of more than 100 nm are present, the dry coating film may have a protrusion-like shape around the position of the particles, and the maximum average roughness Rz of the dry coating film may be increased. There is a risk that both of them will deteriorate significantly.

  On the other hand, the fine powder (nanoparticles) (B) having an average particle diameter of less than 10 nm has a very strong cohesive property and is difficult to disperse to the level of primary particles. Therefore, even if a fine powder dispersion slurry is prepared in the process of manufacturing the paste composition, the dispersion state becomes unstable and precipitation or the like is likely to occur. Further, when such fine powder is used, eventually aggregates (coarse particles) having a size of more than 100 nm tend to be generated, and the smoothness of the dry coating film is deteriorated (arithmetic mean roughness Ra≦20 nm and maximum mean roughness Rz described later). ≦200 nm cannot be satisfied).

  (B) The type of the specific dielectric material used as the dielectric powder is not particularly limited, and may be the same type as or similar to the dielectric material used to form the dielectric layer in the laminated ceramic component. I wish I had it. This is because the (B) dielectric powder is added as a co-material in the internal electrode paste composition according to the present disclosure. Therefore, in the present embodiment or the examples described later, the (B) dielectric powder may be referred to as "co-material powder". As the (B) dielectric powder, one kind or a plurality of kinds of dielectric material powder may be used according to the dielectric layer, or if necessary, one kind of dielectric material powder same as the dielectric layer may be used. The above and one or more kinds of other dielectric material powders may be appropriately combined and used.

Specifically, for example, if the multilayer ceramic component is MLCC, the main component of the dielectric layer is a perovskite-type metal composite oxide such as barium titanate (BaTiO ₃ ) or strontium titanate (SrTiO ₃ ). Used. Therefore, barium titanate powder, strontium titanate powder, or the like can be used as the dielectric powder (B) which is the co-material powder, depending on the dielectric layer.

  Here, for barium titanate used as the dielectric layer, alkaline earth metals such as strontium (Sr) and calcium (Ca), or yttrium (Y), neodymium (Nd), samarium (Sm), A small amount of rare earth metal such as dysprosium (Dy) can be added. Therefore, a small amount of these alkaline earth metals or rare earth metals may be added to barium titanate used as the co-material powder ((B) dielectric powder). The dielectric material used for the (B) dielectric powder may have the same composition as the dielectric material used for the dielectric layer or a different composition depending on the function required as the co-material.

  Further, for example, when the laminated ceramic component is a laminated piezoelectric element, lead zirconate titanate (PZT) or the like is used as the main component of the dielectric layer. Therefore, as the (B) dielectric powder, which is the co-material powder, PZT powder or the like can be used according to the dielectric layer.

  In the present disclosure, (A) conductive powder and (B) dielectric powder may be collectively referred to as a “filler” component or “solid content” in the internal electrode paste composition. As will be described later, the addition amount of the (C) dispersant is set to a suitable amount as a weight based on the total mass of the filler component or the solid content ((A) conductive powder and (B) dielectric powder). be able to.

[(C) Dispersant]
The (C) dispersant used in the internal electrode paste composition according to the present disclosure is one or more alkylamide type dispersions selected from at least one of the following general formula (1) and general formula (2). Any agent may be used.

However, R ¹ in the general formula (1) may be an alkylene group having 2 to 4 carbon atoms, that is, any one of a methylene group, an ethylene group, a propylene group, and a butylene group. When R ¹ is a butylene group, its structure may be an n-butane structure (straight chain structure) or an isobutane structure (2-methylpropane structure, branched chain structure).

R ² in the general formula (2) is an alkyl group having 8 to 18 carbon atoms, that is, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, It may be either a heptadecyl group or an octadecyl group. These alkyl groups may have a straight chain structure or a branched chain structure. R ³ in the general formula (2) is an alkylene group having 8 to 18 carbon atoms, that is, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tridecylene group, a tetradecylene group, a pentadecylene group, a hexadecylene group, It may be either a heptadecylene group or an octadecylene group. These alkylene groups may have a straight chain structure or a branched chain structure.

  Further, n in the general formula (1) or (2) may be an integer of 1 or more and 100 or less. Further, X in the general formula (1) or (2) may be a substituent represented by the following general formula (3) or the following general formula (4).

R ⁴ in the general formula (3) may be an alkyl group having 8 to 18 carbon atoms, similar to R ² in the general formula (2). Further, R ⁵ in the general formula (4) may be an alkylene group having 2 to 4 carbon atoms, like R ¹ in the general formula (1). Further, R ⁶ and R ⁷ in the general formula (4) may each independently be an alkyl group having 1 to 3 carbon atoms, that is, a methyl group, an ethyl group, or a propyl group.

  The synthesis method (production method) of the alkylamide-type dispersant represented by the general formula (1) or (2) is not particularly limited, but as illustrated in Synthesis Examples 1 to 5 of Examples described later, a polyester is used. Any amide compound can be used as long as it is an amide compound obtained by amidating an amine with an amine. As the polyester, those obtained by dehydration esterification of hydroxystearic acid such as 12-hydroxystearic acid or ring-opening esterification of cyclic ester such as β-propiolactone, δ or γ-valerolactone and ε-caprolactone Examples thereof are not particularly limited. Examples of amines include, but are not limited to, N,N'-dimethylaminopropylamine, oleylamine, octylamine and diethylaminopropylamine.

  The molecular weight of the alkylamide type dispersant represented by the general formula (1) or (2) is not particularly limited, but for example, those having a weight average molecular weight Mw in the range of 700 or more and 5000 or less can be preferably used. (C) If the molecular weight of the alkylamide type dispersant as the dispersant is within this range, the filler ((A) conductive powder and (B) dielectric powder) that are “ultrafine particles” having an average particle diameter of 150 nm or less. Can be satisfactorily dispersed in the internal electrode paste composition. In addition, depending on various conditions such as a specific type of filler, an average particle diameter, a content of the filler, and a compounding ratio of (A) conductive powder and (B) dielectric powder, the molecular weight is out of the above range. An alkylamide type dispersant can be used as the (C) dispersant.

  The method for measuring the weight average molecular weight Mw of the alkylamide type dispersant represented by the general formula (1) or (2) is not particularly limited. In the present disclosure, as shown in Examples described later, for example, a polystyrene-equivalent molecular weight based on a calibration curve (calibration curve) obtained by measuring the molecular weight of standard polystyrene using GPC (gel permeation chromatography). I am using.

[(D) Binder Resin, (E) Solvent, and Other Components]
As the (D) binder resin used in the internal electrode paste composition according to the present disclosure, an organic binder known in the field of the internal electrode paste composition for a laminated ceramic component can be preferably used. Specific organic binders include, for example, cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, and cellulose nitrate; acrylic resins such as acrylic resin, methacrylic resin, acrylic ester polymer, and methacrylic ester polymer; polyvinyl butyral resin. Examples thereof include vinyl acetal resins; and the like, but are not particularly limited. As the acrylic resin, more specifically, for example, isobutyl methacrylate homopolymer or a copolymer with a comonomer can be used. Only one kind of these organic binders may be used, or two or more kinds thereof may be appropriately combined.

  The solvent (E) used in the internal electrode paste composition according to the present disclosure is used for adjusting physical properties such as viscosity or fluidity within a range that does not impair various physical properties of the internal electrode paste composition. be able to. In particular, those having good solubility in the (D) binder resin and having a boiling point of 120° C. or higher are preferably used.

  Specific examples of the solvent (E) include terpenes such as terpineol and dihydroterpineol and acetic acid esters thereof; diethylene glycol alkyl ether, ethylene glycol alkyl ether, propylene glycol alkyl ether, dipropylene glycol alkyl ether. And other alkyl glycol ethers and acetic acid esters thereof; pentanediols such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; Only one kind of these solvents may be used, or two or more kinds thereof may be appropriately combined and used.

  In addition, in this indication, (D) binder resin and (E) solvent can also be regarded as one component in the paste composition for internal electrodes as an "organic vehicle." That is, in the present disclosure, the internal electrode paste composition includes (A) conductive powder, (B) dielectric powder, (C) dispersant, and organic vehicle ((D) binder resin and (E) solvent). The composition may consist of

  In addition, the internal electrode paste composition according to the present disclosure may include the above-mentioned components (A) conductive powder, (B) dielectric powder, (C) dispersant, and (D) binder resin. It may be sufficient (if necessary, it may contain a solvent (E)), but may further contain other components in addition to these components (A) to (E). Specific examples of other components include, but are not particularly limited to, stabilizers, antioxidants, ultraviolet absorbers, defoamers, and viscosity modifiers.

[Paste composition for internal electrodes]
The internal electrode paste composition according to the present disclosure contains the above-mentioned (A) conductive powder, (B) dielectric powder, (C) dispersant, and (D) binder resin, and optionally (E). ) It may contain a solvent. Here, in the present disclosure, although the specific content or blending amount of each of the components (A) to (E) is not particularly limited, (A) the conductive powder and ((filler component) which are filler components (solid content). The preferable range of the B) dielectric powder can be given when the total mass of the internal electrode paste composition is 100% by mass.

  Specifically, the content of the conductive powder (A) is not particularly limited, but typically 30% by mass or more and 80% by mass when the total mass of the internal electrode paste composition is 100% by mass. It is preferably within the following range. Depending on various conditions such as the type of multilayer ceramic component, the specific configuration of the internal electrode layer, the specific configuration of the dielectric layer, the specific composition of the internal electrode paste composition, etc., the content of (A) conductive powder is When it is less than 30% by mass of the total mass, good conductivity may not be realized as the internal electrode layer. On the other hand, when the content of the conductive powder (A) exceeds 80% by mass, it depends on various conditions as described above, but in order to contain the (D) binder resin or the organic vehicle within a predetermined range as a “paste”. The content of the (B) dielectric powder as a co-material may be too low.

  The content of the (B) dielectric powder is not particularly limited, but is typically in the range of 1% by mass or more and 10% by mass or less when the total mass of the internal electrode paste composition is 100% by mass. It is preferably within. Depending on the conditions as described above, if the content of the (B) dielectric powder is less than 1 mass% of the total mass, the effect of suppressing delamination of the internal electrode layer and the dielectric layer as a co-material can be obtained. You may not get enough. On the other hand, when the content of the (B) dielectric powder exceeds 10% by mass, the (D) binder resin or the organic vehicle is contained within a predetermined range as the “paste” although it depends on various conditions as described above. May have an excessively low content of the (A) conductive powder.

  In other words, in the internal electrode paste composition according to the present disclosure, if the contents of the filler components (A) conductive powder and (B) dielectric powder are within the above ranges, the internal electrode layer is good. Of these two types of different ultrafine particles by adding an alkylamide type dispersant (C) as a dispersant. It can be well dispersed in the internal electrode paste composition.

  The addition amount (content or blending amount) of the (C) dispersant is not particularly limited, but typically, the total mass of the (A) conductive powder and (B) dielectric powder, which are filler components (solid content). The dispersant (C) can be added within a range of 0.5 parts by mass or more and 7.0 parts by mass or less with respect to 100 parts by mass. The unit of the addition (blending) part by mass of the (C) dispersant ((C) dispersant by mass) relative to 100 parts by mass of the total amount of the filler components ((A) conductive powder and (B) dielectric powder). /100 parts by mass of the filler component) is defined as php (parts hundred of particles). Therefore, for example, when 1 part by mass of the (C) dispersant is added to 100 parts by mass of the filler component, the addition amount of the (C) filler component in the conductive paste for internal electrodes is 1 php.

  If the amount of the (C) dispersant added is less than 0.5 parts by mass (less than 0.5 php) relative to 100 parts by mass of the filler component, these two different types of ultrafine particles may be formed depending on the conditions as described above. It may not be able to be dispersed well in the internal electrode paste composition. That is, if the addition amount is less than 0.5 parts by mass, the dispersion performance of the filler component becomes insufficient. On the other hand, if the amount of the (C) dispersant added to 100 parts by mass of the filler component exceeds 7.0 parts by mass (exceeds 7.0 php), the green sheet laminate is fired, depending on the conditions as described above. The fired laminated body may be in a sparse state, and in this case, sufficient characteristics cannot be obtained as a laminated ceramic component.

  The method for producing the paste composition for internal electrodes according to the present disclosure is not particularly limited, and a method known in the field of paste compositions used for producing laminated ceramic parts can be suitably used. As a typical example, there is a method in which the above-mentioned components are mixed in a predetermined mixing ratio and made into a paste using a known kneading device. The kneading device may be, for example, a known three-roll mill, but is not particularly limited. Further, each component may be premixed before kneading. The premixing device may be, for example, a known planetary stirrer, but is not particularly limited.

  In Examples described later, for example, (B) dielectric powder is first dispersed in (E) solvent to prepare a dispersion slurry of (B) dielectric powder, and (D) binder resin is added to this dispersion slurry. To prepare a binder-added dispersion slurry, further mix (A) a conductive powder with the binder-added dispersion slurry, and (E) adjust the viscosity with a solvent, if necessary, to form an internal electrode paste. The composition is manufactured, and the (C) dispersant is added at the time of preparing the dispersion slurry and at the time of compounding the (A) conductive powder. However, the method for producing the paste composition for internal electrodes according to the present disclosure is not limited to this, and it is possible to satisfactorily disperse (A) conductive powder and (B) dielectric powder, which are two different types of ultrafine particles. If possible, any manufacturing method may be used.

[Multilayer ceramic parts]
The multilayer ceramic component having the internal electrode layer to which the internal electrode paste composition according to the present disclosure can be applied is not particularly limited, and the component has a multilayer structure configured by stacking a large number of dielectric layers and internal electrode layers. If Typical examples include MLCC (multilayer ceramic capacitor) and multilayer piezoelectric element. Examples of the laminated piezoelectric element include a pressure sensor and a laminated piezoelectric actuator. By forming an internal electrode layer using the internal electrode paste composition according to the present disclosure, further thinning (thinning) the dielectric layer and the internal electrode layer in these laminated ceramic components, and these layers Can be expected to be highly laminated.

  For example, in order to reduce the size or increase the capacity of the MLCC, the layer thickness of the dielectric layer and the internal electrode layer is reduced from 1/2 to 800 nm, 500 nm, and 200 nm, which is the conventional thickness, to 1/2 or less to 1/10. Attempts have been made to stratify. However, in the laminated body in which the internal electrode layers and the dielectric layers are alternately laminated, if the layer thickness of each layer is reduced, it is necessary to further improve the smoothness of the internal electrode layers. Specifically, if the thickness of the dielectric layer is 200 nm, the surface of the dry coating film (coating film obtained by coating or printing the internal electrode paste composition and then drying) to be the internal electrode layer. On the (electrode surface), the arithmetic mean roughness Ra is 20 nm or less and the maximum height roughness Rz is 200 nm or less, and a certain high smoothness is required.

  In order to achieve such high smoothness, if ultrafine particles having an average particle size of 150 nm or less are used as the (A) conductive powder and the co-material powder ((B) dielectric powder), it has been conventionally used. The specific surface area is significantly larger than that of fine particles of size. Therefore, even if an attempt is made to satisfactorily disperse such ultrafine particles in the paste composition, the conventional dispersion method has been insufficient. In particular, (A) two types of ultrafine particles having different materials and surface states (usually also average particle size) of conductive powder and co-material powder are well dispersed, and these two types of ultrafine particles in a dry coating film It has been substantially difficult by the conventional dispersion method to make the distribution substantially uniform/homogeneous without different distributions. This point is the same not only in the MLCC but also in the laminated piezoelectric element.

  On the other hand, in the internal electrode paste composition according to the present disclosure, as the (A) conductive powder, ultrafine particles having an average particle size calculated from the specific surface area of 10 nm or more and 150 nm or less are used. B) When ultrafine particles having an average particle size calculated from the specific surface area of 10 to 100 nm are used as the dielectric powder, (C) as the dispersant, the above-mentioned general formula (1) and general formula (1) are used. One or more alkylamide type dispersants selected from at least one of formula (2) are used.

  As a result, not only the ultrafine particles having an average particle size of 150 nm or less can be satisfactorily dispersed in the internal electrode paste composition, but also the (A) conductive powder and the (B) dielectric powder are made of different materials and have different surface states. It is possible to satisfactorily disperse a plurality of types of powder (different kinds of powder), which are special ultrafine particles, in the internal electrode paste composition. Moreover, in the dry coating film formed by this internal electrode paste composition, the distribution of these different powders can be distributed to such an extent that they can be regarded as substantially uniform without being substantially biased.

  As a result, it is possible to form a high-quality internal electrode layer that is thinner than before and is less likely to cause defects, and it is possible to further increase the number of layers of the laminated ceramic component. Therefore, MLCCs can be expected to achieve further miniaturization and higher capacity than conventional ones, and laminated piezoelectric elements can be expected to improve the generated force or electromechanical conversion efficiency. For example, in the case of MLCC, the internal electrode paste composition according to the present disclosure can be preferably used for forming an internal electrode layer of a small MLCC having a size of 0402 (EIA) or less.

  In the present disclosure, the dispersibility in the dried coating film is confirmed by the CV value (variation coefficient), as evaluated in Examples described later. In the dry coating film formed by the internal electrode paste composition according to the present disclosure, when the CV value is 0.3 or less, the (A) conductive powder and the (B) dielectric powder are substantially non-uniformly distributed. It is evaluated to have good covariance.

  Here, the method for producing a laminated ceramic component using the internal electrode paste composition according to the present disclosure is not particularly limited, and a conventionally known method can be preferably used. Generally, a paste composition for forming a dielectric layer (dielectric paste composition) is applied by a known coating method and dried to form a ceramic green sheet to be a dielectric layer. In order to form an electrode pattern to be an internal electrode layer by applying the internal electrode paste composition according to the present disclosure by a known coating method and drying so as to be laminated on the ceramic green sheet, A green sheet laminate may be produced and fired by a known method.

  The coating method of the internal electrode paste composition (and the dielectric paste composition) according to the present disclosure is not particularly limited, and includes a doctor bar method, a transfer printing method, a screen printing method, a screen transfer printing method, and other patterns. The printing method, the slit coater method, the applicator method, the capillary coater method, etc. can be mentioned. The method for drying the formed coating film is not particularly limited, and a conventionally known method can be used.

  The present invention will be described more specifically based on Examples, Comparative Examples and Reference Examples, but the present invention is not limited thereto. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention. The synthesis examples of the (C) dispersant (alkylamide type dispersant) used in the following examples, and the evaluation of the smoothness and co-dispersibility of the dried coating film in the examples and comparative examples are as follows. I went to.

(Synthesis Example of (C) Dispersant)
[Synthesis example 1]
N,N′-dimethylaminopropylamine: 34.0 g, ε-caprolactone: 798,0 g, and dibutyltin laurate: 0.83 g were charged in a four-necked flask equipped with a Dean-Stark water separation tube and a nitrogen introduction tube. While continuing to blow nitrogen into the system, the reaction was continued at 180° C. for 6 hours (Hr) to obtain an alkylamide type dispersant of Synthesis Example 1 (synthetic dispersant 1). The polystyrene reduced molecular weight of this synthetic dispersant 1 was 2500, and the amine equivalent was 2496 eq/g.

[Synthesis example 2]
In a four-necked flask equipped with a Dean-Stark water separation tube and a nitrogen introduction tube, N,N'-dimethylaminopropylamine: 25.5 g, 12-hydroxystearic acid: 730.5 g, dibutyltin laurate: 0.76 g. Each was charged, and 12 Hr reaction was continued at 180° C. while blowing nitrogen into the system to obtain an alkylamide type dispersant of Synthesis Example 2 (synthetic dispersant 2). The polystyrene reduced molecular weight of this synthetic dispersant 2 was 2930, and the amine equivalent was 2926 eq/g.

[Synthesis example 3]
Oleylamine: 53.5 g, β-propiolactone: 720.0 g, and dibutyltin laurate: 0.77 g were charged into a four-necked flask equipped with a Dean-Stark water separation tube and a nitrogen introduction tube, and nitrogen was introduced into the system. While blowing, the reaction was continued for 8 hours at 180° C. to obtain the alkylamide type dispersant of Synthesis Example 3 (synthetic dispersant 3). The polystyrene reduced molecular weight of this synthetic dispersant 3 was 3870.

[Synthesis example 4]
A four-necked flask equipped with a Dean-Stark water separation tube and a nitrogen introduction tube was charged with octylamine: 20.0 g, 12-hydroxystearic acid: 769.5 g, and dibutyltin laurate: 0.79 g, and nitrogen was charged into the system. The reaction was continued for 8 hours at 180° C. while blowing in to obtain the alkylamide type dispersant of Synthesis Example 4 (synthetic dispersant 4). The polystyrene reduced molecular weight of this synthetic dispersant 4 was 4,600.

[Synthesis example 5]
A four-necked flask equipped with a Dean-Stark water separation tube and a nitrogen introduction tube was charged with diethylaminopropylamine: 160.0 g, δ-valerolactone: 738.5 g, and dibutyltin laurate: 0.90 g, and nitrogen was charged into the system. The reaction was continued at 180° C. for 8 hours while blowing in to obtain the alkylamide type dispersant of Synthesis Example 5 (synthetic dispersant 5). The polystyrene reduced molecular weight of this synthetic dispersant 5 was 730, and the amine equivalent was 735 eq/g.

(Evaluation of dry coating film)
[Smoothness of dry coating film]
The obtained paste composition was applied onto a glass substrate with a 30 μm applicator and dried for 1 hr on an 80° C. hot plate to obtain a dry coating film. The arithmetic mean roughness Ra and the surface height roughness Rz of the dried coating film were measured as the surface roughness. The surface roughness Ra and Rz were measured using a stylus type surface roughness meter manufactured by Toyo Seimitsu Co., Ltd., scanning distance: 3 mm, scanning speed: 0.15 mm/sec, cutoff value=0.08. It went on condition of.

  In the present disclosure, it is assumed that the layer thickness of each layer (dielectric layer and internal electrode layer) in the laminated body is 300 nm or less, and the dry coating film serving as the internal electrode layer has arithmetic average roughness Ra≦20 nm, When the surface height roughness Rz≦200 nm, the dry coating film was evaluated as having good smoothness.

[Co-dispersibility of (A) conductive powder and (B) dielectric powder]
The surface of the dry coating film was photographed with an electron microscope at a magnification of 20,000 to obtain a composition image, and the average and standard deviation of the area ratio of the metal portion in 10 randomly selected visual fields from this composition image. Then, the CV value (variation coefficient) was calculated by the following formula.
CV value=(standard deviation of area of metal part)÷(average of area of metal part)
When the CV value is low, it means that the metal powder and the co-material powder (that is, the (A) conductive powder and the (B) dielectric powder) are well distributed without being unevenly distributed. According to the present disclosure, as described above, when the CV value≦0.3 in the dry coating film to be the internal electrode layer, (A) the conductive powder (metal powder) and (B) the dielectric powder in the dry coating film. It was evaluated that the (co-material powder) was distributed substantially uniformly and had good co-dispersibility.

(Example 1)
(B) Barium titanate having a specific surface area of 11.1 g/cm ³ (BET conversion average particle size=89.8 nm) as the dielectric powder: 7.5 g, (C) Synthetic dispersant as the dispersant 1:0. 375 g and (E) terpineol as a solvent: 42.1 g were dispersed in a bead mill for 30 minutes to obtain a barium titanate dispersion slurry.

The obtained dispersion slurry: 60.0 g, and (D) a binder resin, ethyl cellulose (manufactured by The Dow Chemical Company, product name: STD-4): 4.24 g was dissolved and the binder was dissolved. An added dispersion slurry was obtained. Further, with respect to this binder-added dispersion slurry, nickel (Ni) powder having a specific surface area of 5.26 g/cm ³ (BET-converted average particle diameter = 128.0 nm) as conductive powder (A): 30.0 g and (C 1) 1.93 g of a synthetic dispersant as a dispersant was charged, premixed with a planetary stirrer, and then dispersed and mixed with a three-roll mill.

  3.8E g of terpineol as a solvent (E) was added to the obtained dispersion mixture to adjust the viscosity, to obtain a paste composition for internal electrodes (paste composition 1) according to Example 1. With respect to this paste composition 1, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 1.

  In addition, in Table 1 and Tables 2 and 3 described later, in each Example including Comparative Example 1 or Comparative Example, not only the evaluation result of the dry coating film but also the (A) conductivity used in each paste composition was used. The types, the average particle diameters, and the compounding ratios of the conductive powder and the (B) dielectric powder are shown together, and the type of the (C) dispersant used in each paste composition (the alkyl of any one of Synthesis Examples 1 to 5). The amide type dispersant) and the addition amount are shown together. In addition, the addition amount of the (C) dispersant in Tables 1 to 3 is, as described above, the (C) dispersant relative to 100 parts by mass of php (filler component ((A) conductive powder and (B) dielectric powder)). (Parts by mass addition).

  Among these, the compounding ratio of the conductive powder (A) and the compounding ratio of the dielectric powder (B) are both percentages (mass %) of the mass content of each powder in the paste composition. Further, the addition amount of the (C) dispersant is not the mass% in the paste composition, but the total weight of the (A) conductive powder and (B) dielectric powder (co-material powder) (filler component or solid content). The total amount) is shown as an addition part by mass when the total amount is 100 parts by mass.

(Example 2)
(B) Barium titanate having a specific surface area of 33.5/cm ³ as the dielectric powder (BET-converted average particle size=29.8 nm): 7.5 g, (C) Synthetic dispersant 2:0. 375 g and (E) terpineol as a solvent: 42.1 g were dispersed in a bead mill for 30 minutes to obtain a barium titanate dispersion slurry.

To the obtained dispersion slurry: 40.0 g, 5.00 g of ethyl cellulose (manufactured by Dow Chemical Company, product name: STD-4) as a (D) binder resin was dissolved to obtain a binder-added dispersion slurry. Further, with respect to the binder-added dispersion slurry, nickel (Ni) powder having a specific surface area of 8.42 g/cm ³ (BET conversion average particle diameter=80.0 nm) as the conductive powder (A): 40.0 g and (C) ) 1.61 g of a synthetic dispersant as a dispersant was charged, premixed with a planetary stirrer, and then dispersed and mixed with a three-roll mill.

  By adding 13.4 g of terpineol as a solvent (E) to the obtained dispersion mixture to adjust the viscosity, a paste composition according to Example 2 (paste composition 2) was obtained. With respect to this paste composition 2, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 1.

(Example 3)
(B) Barium titanate having a specific surface area of 47.9/cm ³ as the dielectric powder (BET-converted average particle size=20.8 nm): 7.5 g, (C) Synthetic dispersant as a dispersant 3: 0. 375 g and (E) terpineol as a solvent: 42.1 g were dispersed in a bead mill for 30 minutes to obtain a barium titanate dispersion slurry.

To the obtained dispersed slurry: 53.3 g, 5.22 g of (D) ethyl cellulose as a binder resin (manufactured by Dow Chemical Company, product name: STD-4) was dissolved to obtain a binder-added dispersed slurry. Further, with respect to this binder-added dispersion slurry, nickel (Ni) powder having a specific surface area of 13.4 g/cm ³ (BET conversion average particle diameter=50.0 nm) as conductive powder (A): 40.0 g and (C) ) 1.48 g of a synthetic dispersant as a dispersant was charged, premixed with a planetary stirrer, and then dispersed and mixed with a three-roll mill.

  Thereby, the paste composition according to Example 3 (paste composition 3) was obtained. With respect to this paste composition 3, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 1.

(Example 4)
(B) Barium titanate having a specific surface area of 47.9/cm ³ (BET-converted average particle size=20.8 nm) as the dielectric powder: 7.5 g, (C) Synthetic dispersant as a dispersant 4: 0. 375 g and (E) terpineol as a solvent: 42.1 g were dispersed in a bead mill for 30 minutes to obtain a barium titanate dispersion slurry.

5.76 g of ethyl cellulose (manufactured by Dow Chemical Company, product name: STD-4) as a binder resin (D) was dissolved in 20.0 g of the obtained dispersion slurry to obtain a binder-added dispersion slurry. Further, with respect to this binder-added dispersion slurry, nickel (Ni) powder having a specific surface area of 22.5 g/cm ³ (BET conversion average particle diameter=30.0 nm) as conductive powder (A): 50.0 g and (C ) Synthetic dispersant 4: 1.33 g as a dispersant was charged, premixed by a planetary stirrer, and then dispersed and mixed by a three-roll mill.

  The paste composition according to Example 4 (Paste Composition 4) was obtained by adding 22.9 g of terpineol as a solvent (E) to the obtained dispersion mixture to adjust the viscosity. With respect to this paste composition 4, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 1.

(Example 5)
(B) Barium titanate having a specific surface area of 88.2/cm ³ as the dielectric powder (BET-converted average particle size=11.3 nm): 7.5 g, (C) Synthetic dispersant 5:0. 375 g and (E) terpineol as a solvent: 42.1 g were dispersed in a bead mill for 30 minutes to obtain a barium titanate dispersion slurry.

6.52 g of ethyl cellulose (Dow Chemical Company, product name: STD-4) as a (D) binder resin was dissolved in 33.3 g of the obtained dispersion slurry to obtain a binder-added dispersion slurry. Further, with respect to the binder-added dispersion slurry, nickel (Ni) powder having a specific surface area of 22.5 g/cm ³ (BET conversion average particle diameter=30.0 nm) as conductive powder (A): 55.0 g and (C) ) 1.50 g of synthetic dispersant 5 as a dispersant was charged, premixed with a planetary stirrer, and then dispersed and mixed with a three-roll mill.

  3.68 g of terpineol as a solvent (E) was added to the obtained dispersion mixture to adjust the viscosity to obtain a paste composition according to Example 5 (paste composition 5). With respect to this paste composition 5, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 1.

(Example 6)
(B) PZT powder having a specific surface area of 10.0/cm ³ as a dielectric powder (BET-converted average particle size=49.8 nm): 7.5 g, (C) Synthetic dispersant as a dispersant 1: 0.375 g , (E) terpineol as a solvent: 42.1 g was dispersed in a bead mill for 30 minutes to obtain a dispersion slurry of PZT powder.

6.96 g of ethyl cellulose (manufactured by Dow Chemical Company, product name: STD-4) as a binder resin (D) was dissolved in 26.7 g of the obtained dispersion slurry to obtain a binder-added dispersion slurry. Further, with respect to the binder-added dispersed slurry, (A) palladium (Pd) powder having a specific surface area of 10.0 g/cm ³ (BET conversion average particle diameter=50.0 nm) as conductive powder: 60.0 g and (C ) 1.60 g of a synthetic dispersant as a dispersant was charged, premixed with a planetary stirrer, and then dispersed and mixed with a three-roll mill.

  The paste composition according to Example 6 (Paste Composition 6) was obtained by adding 4.74 g of terpineol as a solvent (E) to the obtained dispersion mixture to adjust the viscosity. With respect to this paste composition 6, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 2.

(Example 7)
(B) PZT powder having a specific surface area of 26.0/cm ³ as the dielectric powder (BET-converted average particle size=30.0 nm): 7.5 g, (C) Synthetic dispersant as the dispersant 1: 0.375 g , (E) terpineol as a solvent: 42.1 g was dispersed in a bead mill for 30 minutes to obtain a dispersion slurry of PZT powder.

To the obtained dispersion slurry: 6.67 g, a binder-added dispersion slurry was prepared by adding 9.72 g of a terpineol 50 mass% solution of (D) a binder resin, ethyl cellulose (manufactured by Dow Chemical Company, product name: STD-4). Obtained. Further, with respect to this binder-added dispersion slurry, platinum (Pt) powder having a specific surface area of 10.0 g/cm ³ (BET conversion average particle diameter=50.0 nm) as conductive powder (A): 80.0 g and (C) ) 1:1.00 g of a synthetic dispersant as a dispersant was charged, premixed with a planetary stirrer, and then dispersed and mixed with a three-roll mill.

  2.61 g of terpineol as a solvent (E) was added to the obtained dispersion mixture to adjust the viscosity to obtain a paste composition according to Example 7 (paste composition 7). With respect to this paste composition 7, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 2.

(Example 8)
(B) PZT powder having a specific surface area of 26.0/cm ³ as a dielectric powder (BET-converted average particle size=30.0 nm): 7.5 g, (C) Synthetic dispersant as a dispersant 2: 0.375 g , (E) terpineol as a solvent: 42.1 g was dispersed in a bead mill for 30 minutes to obtain a dispersion slurry of PZT powder.

To the obtained dispersion slurry: 13.3 g, a binder-added dispersion slurry was added by adding 13.5 g of a terpineol 50 mass% solution of (D) ethyl cellulose (manufactured by Dow Chemical Company, product name: STD-4) as a binder resin. Obtained. Further, with respect to this binder-added dispersion slurry, the silver (Ag)/palladium (Pd) ratio of the specific surface area of the conductive powder (A) of 18.3 g/cm ³ (BET conversion average particle diameter=50.0 nm)=70. /30 alloy powder: 60.0 g and (C) a synthetic dispersant as a dispersant 2: 1.55 g were charged, premixed by a planetary stirrer, and then dispersed and mixed by a three-roll mill.

  By adding 11.7 g of terpineol as a solvent (E) to the obtained dispersion mixture to adjust the viscosity, a paste composition according to Example 8 (paste composition 8) was obtained. With respect to this paste composition 8, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 2.

(Example 9)
(B) PZT powder having a specific surface area of 26.0/cm ³ as a dielectric powder (BET-converted average particle diameter=30.0 nm): 7.5 g, (C) Synthetic dispersant as a dispersant 2: 0.375 g , (E) terpineol as a solvent: 42.1 g was dispersed in a bead mill for 30 minutes to obtain a dispersion slurry of PZT powder.

To the obtained dispersion slurry: 6.67 g, a binder-added dispersion slurry was prepared by adding 16.5 g of a terpineol 50 mass% solution of (D) a binder resin, ethyl cellulose (manufactured by Dow Chemical Company, product name: STD-4). Obtained. Further, with respect to this binder-added dispersion slurry, the silver (Ag)/palladium (Pd) ratio of the specific surface area of the conductive powder (A) of 18.3 g/cm ³ (BET conversion average particle diameter=50.0 nm)=70. /30 alloy powder: 75.0 g and (C) a synthetic dispersant as a dispersant 2: 0.83 g were charged, premixed with a planetary stirrer, and then dispersed and mixed with a three-roll mill.

  1.43 g of terpineol as a solvent (E) was added to the obtained dispersion mixture to adjust the viscosity to obtain a paste composition according to Example 9 (paste composition 9). With respect to this paste composition 9, the smoothness of the dried coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 2.

(Comparative Example 1)
A paste composition according to Comparative Example 1 (Comparative Paste Composition 1) was obtained in the same manner as in Example 2 except that polyethyleneimine having a weight average molecular weight (Mw) of 1800 was used as the dispersant. For this comparative paste composition 1, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 3.

(Comparative example 2)
A paste composition according to Comparative Example 2 (Comparative Paste Composition 2) was obtained in the same manner as in Example 2 except that lauroylmethyl-β-alanine was used as the dispersant. As for the comparative paste composition 2, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 3.

(Comparative example 3)
In the same manner as in Example 2 except that a polyester-based dispersant having an amine value of 93 mgKOH/g (manufactured by Nippon Lubrizol Co., Ltd., product name: Solsperse 13940) having secondary and tertiary amino groups was used as the dispersant. A paste composition according to Comparative Example 3 (Comparative Paste Composition 3) was obtained. With respect to this comparative paste composition 3, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 3.

(Comparative example 4)
A paste according to Comparative Example 4 in the same manner as in Example 2 except that a polyurethane-polyester-based dispersant having a tertiary amino group (manufactured by BYK Japan KK, product name: BYK-2155) was used as the dispersant. A composition (comparative paste composition 4) was obtained. As to the comparative paste composition 4, the smoothness of the dry coating film and the co-dispersibility of the powder were evaluated as described above. The results are shown in Table 3.

(Comparison of Examples and Comparative Examples)
From the results of Examples 1 to 5, when (A) the ultrafine nickel powder was used as the conductive powder and (B) the ultrafine barium titanate powder was used as the dielectric powder (co-material powder), By using the alkylamide type dispersant represented by the general formula (1) or the general formula (2) as the dispersant C), the dry coating film obtained has good smoothness and dispersibility. Therefore, it is considered that by using the internal electrode paste composition according to the present disclosure for the internal electrode layer of the MLCC, it is possible to achieve thinning and high stacking.

  From the results of Examples 6 to 9, ultrafine particles of palladium powder, platinum powder, or silver/palladium alloy powder were used as (A) conductive powder, and ultrafine particles were used as (B) dielectric powder (co-material powder). When the PZT powder of No. 2 is used, the smoothness and dispersibility of the dry coating film obtained by using the alkylamide type dispersant of the general formula (1) or (2) as the dispersant (C) are good. It has become. Therefore, it is considered that by using the internal electrode paste composition according to the present disclosure for the internal electrode layer of the laminated piezoelectric element, it is possible to achieve thinning and high lamination.

  From the results of Examples 1 to 9 (see Synthesis Examples 1 to 5), it is preferable that the weight average molecular weight Mw of the alkylamide type dispersant (C) is 700 to 5000. I understand. Similarly, it is understood that the addition amount of the alkylamide type dispersant is preferably within a range of 0.5 to 7.0 parts by mass, when the total mass of the filler component (solid content) is 100 parts by mass. Further, from the results of Examples 1 to 9, the content of (A) the conductive powder is preferably in the range of 30 to 80% by mass, and the content of (B) the dielectric powder is in the range of 1 to 10% by mass. It turns out to be preferable.

  On the other hand, as is clear from the results of Comparative Examples 1 to 4, when the dispersant is a known dispersant that is not an alkylamide type dispersant, the smoothness and dispersibility of the dried coating film are not sufficient. .. Therefore, from these examples and comparative examples, even when ultrafine particles are used as the conductive powder (A) and the dielectric powder (B), by using the alkylamide type dispersant as the dispersant (C), 2 Good codispersibility which is considered to be substantially free of secondary agglomerates, good smoothness in a dry coating film, and (A) conductive powder and (B) dielectric material in a dry coating film can be realized. It also allows the powder to be distributed substantially homogeneously. Further, since the (A) conductive powder and the (B) dielectric powder can be well co-dispersed, a viscosity or fluidity suitable for coating can be realized.

  It should be noted that the present invention is not limited to the description of the above-described embodiment, and various modifications can be made within the scope shown in the claims, and are disclosed in different embodiments and a plurality of modified examples. Embodiments obtained by appropriately combining the above technical means are also included in the technical scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be widely and suitably used in the field of manufacturing laminated ceramic parts such as a laminated ceramic capacitor (MLCC) and a laminated piezoelectric element.

Claims (9)

It is used for forming an internal electrode layer of a laminated ceramic component, and contains (A) conductive powder, (B) dielectric powder, (C) dispersant, and (D) binder resin,
The conductive powder (A) has an average particle size calculated from its specific surface area of 10 nm or more and 150 nm or less,
The (B) dielectric powder has an average particle size calculated from its specific surface area of 10 nm or more and 100 nm or less,
The (C) dispersant is one or more alkylamide type dispersants selected from at least one of the following general formula (1) and general formula (2).

(However, R ¹ in the general formula (1) is an alkylene group having 2 to 4 carbon atoms, R ² in the general formula (2) is an alkyl group having 8 to 18 carbon atoms, and R ³ is a carbon number. Is an alkylene group of 8 to 18, n in the general formula (1) or (2) is an integer of 1 or more and 100 or less, and X is a substituent represented by the following general formula (3) or the following general formula (4). The base,

R ⁴ in the general formula (3) is an alkyl group having 8 to 18 carbon atoms, R ⁵ in the general formula (4) is an alkylene group having 2 to 4 carbon atoms, and R ⁶ and R ⁷ are each independently. And is an alkyl group having 1 to 3 carbon atoms. )
Is characterized by
Internal electrode paste composition. The weight average molecular weight of the alkylamide-type dispersant that is the (C) dispersant is in the range of 700 or more and 5000 or less,
The paste composition for internal electrodes according to claim 1. The amount of the (C) dispersant added is in the range of 0.5 parts by mass or more and 7.0 parts by mass or less based on 100 parts by mass of the total amount of the (A) conductive powder and the (B) dielectric powder. Characterized by being
The paste composition for internal electrodes according to claim 1 or 2. The conductive powder (A) is a metal powder containing at least one selected from the group consisting of silver (Ag), palladium (Pd), platinum (Pt), and nickel (Ni). ,
The paste composition for internal electrodes according to any one of claims 1 to 3. The dielectric powder (B) is barium titanate or lead zirconate titanate (PZT) powder,
The paste composition for internal electrodes according to any one of claims 1 to 4. The content of the conductive powder (A) is in the range of 30% by mass or more and 80% by mass or less, when the total mass of the internal electrode paste composition is 100% by mass.
The paste composition for internal electrodes according to any one of claims 1 to 5. The content of the (B) dielectric powder is in the range of 1% by mass or more and 10% by mass or less, when the total mass of the internal electrode paste composition is 100% by mass.
The paste composition for internal electrodes according to any one of claims 1 to 6. An internal electrode layer formed of the internal electrode paste composition according to any one of claims 1 to 7 and a dielectric layer are laminated,
Multilayer ceramic parts. A laminated ceramic capacitor or a laminated piezoelectric element,
The multilayer ceramic component according to claim 8.