WO2021020557A1 - Conductive paste for gravure printing, electronic component, and laminate ceramic capacitor - Google Patents

Conductive paste for gravure printing, electronic component, and laminate ceramic capacitor Download PDF

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Publication number
WO2021020557A1
WO2021020557A1 PCT/JP2020/029417 JP2020029417W WO2021020557A1 WO 2021020557 A1 WO2021020557 A1 WO 2021020557A1 JP 2020029417 W JP2020029417 W JP 2020029417W WO 2021020557 A1 WO2021020557 A1 WO 2021020557A1
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Prior art keywords
conductive paste
mass
gravure printing
dispersant
powder
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PCT/JP2020/029417
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French (fr)
Japanese (ja)
Inventor
祐伺 舘
純平 山田
Original Assignee
住友金属鉱山株式会社
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Application filed by 住友金属鉱山株式会社 filed Critical 住友金属鉱山株式会社
Priority to CN202080051963.8A priority Critical patent/CN114207741A/en
Priority to JP2021535459A priority patent/JPWO2021020557A1/ja
Priority to KR1020217036295A priority patent/KR20220042052A/en
Publication of WO2021020557A1 publication Critical patent/WO2021020557A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/52—Electrically conductive inks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/02—Printing inks
    • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/14—Conductive material dispersed in non-conductive inorganic material
    • H01B1/16—Conductive material dispersed in non-conductive inorganic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G4/00—Fixed capacitors; Processes of their manufacture
    • H01G4/002—Details
    • H01G4/005—Electrodes
    • H01G4/008—Selection of materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G4/00—Fixed capacitors; Processes of their manufacture
    • H01G4/002—Details
    • H01G4/228—Terminals
    • H01G4/232—Terminals electrically connecting two or more layers of a stacked or rolled capacitor
    • H01G4/2325—Terminals electrically connecting two or more layers of a stacked or rolled capacitor characterised by the material of the terminals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES OR LIGHT-SENSITIVE DEVICES, OF THE ELECTROLYTIC TYPE
    • H01G4/00—Fixed capacitors; Processes of their manufacture
    • H01G4/30—Stacked capacitors

Definitions

  • the present invention relates to a conductive paste for gravure printing, electronic components, and a multilayer ceramic capacitor.
  • a multilayer ceramic capacitor has a structure in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately laminated, and by thinning these dielectric layers and internal electrode layers, miniaturization and high capacity can be achieved. Can be planned.
  • Multilayer ceramic capacitors are manufactured, for example, as follows. First, a paste for an internal electrode (conductive) containing a conductive powder, a binder resin, an organic solvent, and the like on the surface of a dielectric green sheet containing a dielectric powder such as barium titanate (BaTIO 3 ) and a binder resin. A laminated body is obtained by stacking a paste) printed with a predetermined electrode pattern in multiple layers. Next, the laminated body is heat-bonded and integrated to form a pressure-bonded body. The pressure-bonded body is cut and subjected to a deorganizing binder treatment in an oxidizing atmosphere or an inert atmosphere, and then fired to obtain a fired chip. Next, pastes for external electrodes are applied to both ends of the fired chip, and after firing, the surface of the external electrodes is nickel-plated or the like to obtain a multilayer ceramic capacitor.
  • a paste for an internal electrode (conductive) containing a conductive powder, a binder resin, an organic solvent, and the like on the
  • a screen printing method has been generally used as a printing method used when printing a conductive paste on a dielectric green sheet, but due to the demand for miniaturization, thinning, and productivity improvement of electronic devices. , It is required to print finer electrode patterns with high productivity.
  • gravure is a continuous printing method in which the concave portion provided in the plate making is filled with the conductive paste and pressed against the surface to be printed to transfer the conductive paste from the plate making.
  • a printing method has been proposed.
  • the gravure printing method has a high printing speed and is excellent in productivity.
  • it is necessary to appropriately select the binder resin, dispersant, solvent, etc. in the conductive paste and adjust the characteristics such as viscosity within a range suitable for gravure printing.
  • a conductive paste used for forming the inner conductor film in a laminated ceramic electronic component including a plurality of ceramic layers and an inner conductor film extending along a specific interface between the ceramic layers by gravure printing.
  • the solvent component as the balance, the viscosity ⁇ 0.1 at a shear rate of 0.1 (s -1 ) is 1 Pa ⁇ s or more, and the viscosity at a shear rate of 0.02 (s -1 ).
  • Patent Document 2 a conductive paste used for forming by gravure printing as in Patent Document 1, wherein 30 to 70% by weight of a solid component containing a metal powder and 1 to 10% by weight of a solid component are used.
  • a thixotropy fluid containing a resin component, a dispersant of 0.05 to 5% by weight, and a solvent component as a balance, and having a viscosity of 1 Pa ⁇ s or more at a shear rate of 0.1 (s -1 ).
  • conductive pastes having a viscosity change rate of 50% or more at a shear rate of 10 (s -1 ), based on the viscosity at a shear rate of 0.1 (s -1 ).
  • these conductive pastes are thixotropy fluids having a viscosity of 1 Pa ⁇ s or more at a shear rate of 0.1 (s -1 ), and are stable at high speed in gravure printing. It is said that continuous printability can be obtained and laminated ceramic electronic components such as multilayer ceramic capacitors can be manufactured with good production efficiency.
  • Patent Document 3 describes conductivity for an internal electrode of a multilayer ceramic capacitor containing a conductive powder (A), an organic resin (B), an organic solvent (C), an additive (D), and a dielectric powder (E).
  • the organic resin (B) is a sex paste composed of polyvinyl butyral having a degree of polymerization of 10,000 or more and 50,000 or less and ethyl cellulose having a weight average molecular weight of 10,000 or more and 100,000 or less
  • the organic solvent (C) is propylene glycol monobutyl ether.
  • a conductive paste for gravure printing which comprises a composition containing a polycarboxylic acid polymer or a salt of polycarboxylic acid as an inhibitor, is described. According to Patent Document 3, this conductive paste has a viscosity suitable for gravure printing, the uniformity and stability of the paste are improved, and the drying property is good.
  • the conductive paste for gravure printing is required to have a low viscosity.
  • the ceramic powder such as barium titanate and the conductive powder such as Ni are added, these powders are compared with the high-viscosity conductive paste for screen printing and the like.
  • the difference in settling speed due to the difference in specific gravity has a more remarkable effect, and the conductive powder and the ceramic powder are easily separated.
  • a phenomenon called "whitening" may occur in which a white separation layer containing ceramic powder is generated at the upper part when the conductive paste is produced.
  • the conductive paste for gravure printing contains a conductive powder, a ceramic powder, an additive, a binder resin and an organic solvent, and the additive is a dicarboxylic acid and a dispersant other than the dicarboxylic acid.
  • a conductive paste for gravure printing which comprises, and contains a dicarboxylic acid in an amount of 0.1% by mass or more and less than 3.0% by mass based on the entire conductive paste.
  • the dispersant is preferably contained in an amount of 0.01% by mass or more and 3.0% by mass or less with respect to the entire conductive paste.
  • the dispersant preferably contains one or both of an acid-based dispersant and a basic-based dispersant.
  • the conductive powder preferably contains at least one metal powder selected from Ni, Pd, Pt, Au, Ag, Cu and alloys thereof.
  • the conductive powder preferably has an average particle size of 0.05 ⁇ m or more and 1.0 ⁇ m or less.
  • the ceramic powder preferably contains barium titanate. The ceramic powder preferably has an average particle size of 0.01 ⁇ m or more and 0.5 ⁇ m or less.
  • the ceramic powder is preferably contained in an amount of 1% by mass or more and 20% by mass or less with respect to the entire conductive paste.
  • the binder resin contains a cellulosic resin.
  • the viscosity at shear rate 100 sec -1 is not higher than 3 Pa ⁇ S, it is preferable that the viscosity at a shear rate 10000 sec -1 is less than 1 Pa ⁇ S.
  • an electronic component formed by using the above conductive paste is provided.
  • the internal electrode layer is a laminated ceramic capacitor formed by using the above-mentioned conductive paste for gravure printing.
  • the conductive paste of the present invention has properties suitable for gravure printing, can suppress the separation of the conductive powder and the ceramic powder even in a low-viscosity paste, and when forming a thinned electrode. Also has excellent printability. Further, the internal electrode layer formed by using the conductive paste of the present invention can uniformly cover the dielectric layer even when it is thinned.
  • FIG. 1A and 1B are a perspective view (FIG. 1A) and a cross-sectional view (FIG. 1B) showing the multilayer ceramic capacitor according to the embodiment.
  • the conductive paste of this embodiment contains a conductive powder, a ceramic powder, an additive, a binder resin and an organic solvent.
  • a conductive powder a conductive powder, a ceramic powder, an additive, a binder resin and an organic solvent.
  • the conductive powder is not particularly limited, and a metal powder can be used.
  • Ni, Pd, Pt, Au, Ag, Cu, and one or more powders selected from these alloys can be used. ..
  • Ni or its alloy (Ni alloy) powder is preferable from the viewpoint of conductivity, corrosion resistance and cost.
  • Ni alloy for example, an alloy of at least one element selected from the group consisting of Mn, Cr, Co, Al, Fe, Cu, Zn, Ag, Au, Pt and Pd and Ni can be used. it can.
  • the content of Ni in the Ni alloy is, for example, 50% by mass or more, preferably 80% by mass or more.
  • the Ni powder may contain an element S of about several hundred ppm in order to suppress abrupt gas generation due to partial thermal decomposition of the binder resin during the debinder treatment.
  • the average particle size of the conductive powder is preferably 0.05 ⁇ m or more and 1.0 ⁇ m or less, and more preferably 0.1 ⁇ m or more and 0.5 ⁇ m or less.
  • the average particle size of the conductive powder is within the above range, it can be suitably used as a paste for an internal electrode of a thinned laminated ceramic capacitor (laminated ceramic component).
  • the smoothness of the dried film and the density of the dried film are high. improves.
  • the average particle size is a value obtained from observation with a scanning electron microscope (SEM), and is obtained by measuring the particle size of each of a plurality of particles from an image observed with an SEM at a magnification of 10,000 times. It is an average value (SEM average particle diameter) to be obtained.
  • the content of the conductive powder is preferably 30% by mass or more and less than 70% by mass, and more preferably 40% by mass or more and 60% by mass or less with respect to the entire conductive paste. When the content of the conductive powder is within the above range, the conductivity and dispersibility are excellent.
  • the ceramic powder is not particularly limited, and for example, in the case of a paste for an internal electrode of a multilayer ceramic capacitor, a known ceramic powder is appropriately selected depending on the type of the laminated ceramic capacitor to be applied.
  • a perovskite-type oxide containing Ba and Ti can be used, and barium titanate (BaTIO 3 ) is preferably contained.
  • a ceramic powder containing barium titanate as a main component and an oxide as a sub component may be used.
  • the oxide include one or more oxides selected from Mn, Cr, Si, Ca, Ba, Mg, V, W, Ta, Nb and rare earth elements.
  • ceramic powders include ceramic powders of perovskite-type oxide ferroelectrics in which the Ba atom or Ti atom of barium titanate (BaTIO 3 ) is replaced with another atom, for example, Sn, Pb, Zr or the like. Can be mentioned.
  • the ceramic powder used for the conductive paste for the internal electrode a powder having the same composition as the dielectric ceramic powder constituting the green sheet of the multilayer ceramic capacitor (electronic component) may be used. As a result, the generation of cracks due to the shrinkage mismatch at the interface between the dielectric layer and the internal electrode layer in the sintering process is suppressed.
  • Such ceramic powders include, for example, ZnO, ferrite, PZT, BaO, Al 2 O 3 , Bi 2 O 3 , R (rare earth element) 2 O 3 , in addition to the perovskite oxide containing Ba and Ti. Oxides such as TiO 2 and Nd 2 O 3 can be mentioned.
  • the ceramic powder one type may be used, or two or more types may be used.
  • the average particle size of the ceramic powder is, for example, 0.01 ⁇ m or more and 0.5 ⁇ m or less, preferably 0.01 ⁇ m or more and 0.3 ⁇ m or less.
  • the average particle size is a value obtained from observation with a scanning electron microscope (SEM), and is obtained by measuring the particle size of each of a plurality of particles from an image observed with an SEM at a magnification of 50,000 times. It is an average value (SEM average particle diameter) to be obtained.
  • the content of the ceramic powder is preferably 1% by mass or more and 20% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire conductive paste.
  • the content of the ceramic powder is in the above range, the dispersibility and sinterability are excellent.
  • the content of the ceramic powder is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 3 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the conductive powder.
  • the binder resin is not particularly limited, and a known resin can be used.
  • the binder resin include cellulosic resins such as methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose and nitrocellulose, acrylic resins, and acetal resins containing butyral resins such as polyvinyl butyral.
  • cellulosic resins such as methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose and nitrocellulose
  • acrylic resins and acetal resins containing butyral resins such as polyvinyl butyral.
  • acetal resins containing butyral resins such as polyvinyl butyral.
  • it is preferable to contain a cellulosic resin and more preferably ethyl cellulose is contained.
  • it When used as a paste for an internal electrode, it may contain a butyral resin or may be used alone from the viewpoint of improving the adhesive strength with the green
  • the binder resin contains an acetal resin
  • the viscosity can be easily adjusted to be suitable for gravure printing, and the adhesive strength with the green sheet can be further improved.
  • the binder resin may contain, for example, 20% by mass or more of the acetal resin or 30% by mass or more of the total binder resin. Further, the binder resin may contain 80% by mass or less of the acetal-based resin with respect to the entire binder resin.
  • the degree of polymerization and weight average molecular weight of the binder resin can be appropriately adjusted within the above range according to the required viscosity of the conductive paste.
  • the content of the binder resin is preferably 0.5% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 7% by mass or less with respect to the entire conductive paste.
  • the conductivity and dispersibility are excellent.
  • the content of the binder resin is preferably 1 part by mass or more and 20 parts by mass or less, and more preferably 1 part by mass or more and 14 parts by mass or less with respect to 100 parts by mass of the conductive powder.
  • the organic solvent is not particularly limited, and a known organic solvent capable of dissolving the binder resin can be used.
  • examples of the organic solvent include glycol ether-based solvent, acetate-based solvent, acetic acid ester-based solvent, ketone-based solvent, terpene-based solvent, aliphatic hydrocarbon solvent and the like.
  • the organic solvent one type may be used, or two or more types may be used.
  • glycol ether-based solvent examples include (di) ethylene glycol ethers such as diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monohexyl ether, and ethylene glycol monohexyl ether, and propylene glycol.
  • ethylene glycol ethers such as diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monohexyl ether, and ethylene glycol monohexyl ether
  • propylene glycol examples include propylene glycol monoalkyl ethers such as monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether (PNB).
  • PNB propylene glycol monobutyl ether
  • propylene glycol monoalkyl ethers are preferable, and propylene glycol monobutyl ether (PNB) is more preferable.
  • the organic solvent contains a glycol ether solvent, it has excellent compatibility with the above-mentioned binder resin and excellent drying property.
  • the organic solvent may contain, for example, 25% by mass or more of the glycol ether solvent, 50% by mass or more, or only the glycol ether solvent with respect to the entire organic solvent. Further, the glycol ether solvent may be used alone or in combination of two or more.
  • Examples of the acetate solvent include dihydroterpinyl acetate, isobornyl acetate, isobornyl propinate, isobornyl butyrate, isobornyl isobutyrate, ethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether.
  • Examples thereof include glycol ether acetates such as acetate, 3-methoxy-3-methylbutyl acetate and 1-methoxypropyl-2-acetate.
  • Examples of the acetic acid ester solvent include ethyl acetate, propyl acetate, isobutyl acetate, and butyl acetate.
  • Examples of the ketone solvent include methyl ethyl ketone and methyl isobutyl ketone.
  • Examples of the terpene-based solvent include tarpineol (TPO) and dihydroterpineol (DHT). Among them, dihydroterpineol (DHT) is preferable from the viewpoint of improving the coverage of the internal electrode layer.
  • Examples of the aliphatic hydrocarbon solvent include tridecane, nonane, cyclohexane and the like, and among them, mineral spirit (MA) is more preferable.
  • the organic solvent may contain, for example, 25% by mass or more of the terpene solvent, 50% by mass or more, or only the terpene solvent with respect to the entire organic solvent. Further, the terpene solvent may be used alone or in combination of two or more.
  • the content of the organic solvent is preferably 20% by mass or more and 50% by mass or less, and more preferably 25% by mass or more and 45% by mass or less with respect to the total amount of the conductive paste.
  • the conductivity and dispersibility are excellent.
  • the content of the organic solvent is preferably 50 parts by mass or more and 130 parts by mass or less, and more preferably 60 parts by mass or more and 90 parts by mass or less with respect to 100 parts by mass of the conductive powder.
  • the conductivity and dispersibility are excellent.
  • the organic solvent can contain, for example, a glycol ether solvent as a main solvent and an aliphatic hydrocarbon solvent as a secondary solvent.
  • the glycol ether-based solvent is preferably contained in an amount of 30 parts by mass or more and 50 parts by mass or less, more preferably 40 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the conductive powder, and is an aliphatic hydrocarbon solvent. Is preferably contained in an amount of 20 parts by mass or more and 80 parts by mass or less, and more preferably 20 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the conductive powder.
  • the additive includes a dicarboxylic acid and a dispersant other than the dicarboxylic acid.
  • a dispersant other than the dicarboxylic acid Asinafter, each component will be described.
  • the present inventor suppresses the separation of the conductive powder and the ceramic powder by containing a specific amount of the dicarboxylic acid in the conductive paste for gravure printing, and has a high coverage when the internal electrode layer is formed. I found that I could do it.
  • Dicarboxylic acid is a carboxylic acid-based additive having two carboxyl groups (COO - groups).
  • dicarboxylic acids examples include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid and 2,6-naphthalenedicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid and azelaic acid.
  • 1,2-Cyclohexanedicarboxylic acid 4-methylhexahydrohydride phthalic acid, 3-methylhexahydrohydride phthalic acid, 2-methylhexahydride phthalic acid, dicarboxyhydrogenated bisphenol A, dicarboxyhydrogenated bisphenol S, hydrogen Examples thereof include alicyclic dicarboxylic acids such as added naphthalenedicarboxylic acid and tricyclodecanedicarboxylic acid.
  • the average molecular weight of the dicarboxylic acid is not particularly limited, but may be, for example, 1000 or less, 500 or less, or 400 or less. When the average molecular weight of the dicarboxylic acid is in the above range, a high separation suppressing effect can be obtained.
  • the lower limit of the average molecular weight of the dicarboxylic acid may be, for example, 100 or more, or 150 or more.
  • the dicarboxylic acid is contained in an amount of 0.1% by mass or more and less than 3.0% by mass and 0.3% by mass or more and 1.0% by mass or less based on the entire conductive paste. It is preferably contained.
  • the content of the dicarboxylic acid is 3.0% by mass or more, the drying is insufficient in the printing and drying steps, the internal electrode layer becomes soft, and the lamination misalignment occurs in the subsequent lamination process or remains during firing. Dicarboxylic acid is vaporized, and the vaporized gas component may generate internal stress or structural destruction of the laminate.
  • the conductive paste according to the present embodiment contains a dicarboxylic acid and a dispersant other than the dicarboxylic acid to improve the dispersibility of the conductive paste and suppress the separation of the conductive powder and the ceramic powder. , It is possible to improve the coverage when the internal electrode layer is formed.
  • the conductive paste according to the present embodiment may contain, for example, one or both of an acid-based dispersant and a basic-based dispersant as the dispersant.
  • the acid-based dispersant may include an acid-based dispersant having a carboxyl group other than the dicarboxylic acid.
  • a comb-shaped carboxylic acid a polycarboxylic acid having a comb-shaped structure
  • the dispersibility of the conductive paste is improved by containing the comb-shaped carboxylic acid, but the dispersibility is different from that of the conductive powder. The effect of suppressing separation from ceramic powder is small.
  • the dispersant one type may be used, or two or more types may be used.
  • the conductive paste according to the present embodiment has improved dispersibility by containing a dispersant.
  • an acid-based dispersant having a hydrocarbon group may be contained.
  • examples of such an acid-based dispersant include acid-based dispersants such as higher fatty acids and polymer surfactants, and phosphoric acid-based dispersants. These dispersants may be used alone or in combination of two or more.
  • the higher fatty acid may be an unsaturated carboxylic acid or a saturated carboxylic acid, and is not particularly limited, but has 11 or more carbon atoms such as stearic acid, oleic acid, myristic acid, palmitic acid, linoleic acid, lauric acid, and linolenic acid. Can be mentioned. Of these, oleic acid or stearic acid is preferable.
  • the other acid-based dispersant is not particularly limited, but for example, an alkyl monoamine salt type is preferable.
  • alkyl monoamine salt type examples include oleoyl zarcosine, which is a compound of glycine and oleic acid, stearic acid amide, which is an amide compound using a higher fatty acid such as stearic acid or lauric acid instead of oleic acid, and lauriloyl. Zarcosin is preferred.
  • the dispersant may contain a dispersant other than the acid-based dispersant.
  • examples of the dispersant other than the acid-based dispersion include a basic-based dispersant, a nonionic dispersant, and an amphoteric dispersant. These dispersants may be used alone or in combination of two or more.
  • the conductive paste according to the present embodiment may contain, for example, a base-based dispersant as the dispersant, or may contain only the base-based dispersant as the dispersant.
  • the basic dispersant include aliphatic amines such as laurylamine, rosinamine, cetylamine, myristylamine, stearylamine, and oleylamine.
  • the conductive paste contains the above-mentioned acid-based dispersant having a branched hydrocarbon group and a basic-based dispersion, it is more excellent in dispersibility and viscosity stability over time.
  • the dispersant is preferably contained in an amount of 3% by mass or less based on the entire conductive paste.
  • the range including the upper limit of the content of the dispersant is preferably 2% by mass or less, and more preferably 1% by mass or less.
  • the range including the lower limit of the content of the dispersant is not particularly limited, but is, for example, 0.01% by mass or more, preferably 0.05% by mass or more.
  • the dispersant is preferably contained in an amount of 0.01 part by mass or more and 5 parts by mass or less, more preferably 0.05 part by mass or more and 3 parts by mass or less, more preferably, based on 100 parts by mass of the conductive powder. It is contained in an amount of 0.4 parts by mass or more and 3 parts by mass or less.
  • the content of the dispersant is within the above range, the dispersibility of the conductive powder or ceramic powder and the smoothness of the surface of the dry electrode after coating are excellent, and the viscosity of the conductive paste is adjusted to an appropriate range. In addition, deterioration of dryness after printing can be prevented, and sheet attack and poor peeling of the green sheet can be suppressed.
  • the conductive paste of the present embodiment may contain other additives other than the above-mentioned components, if necessary.
  • additives conventionally known additives such as defoamers, plasticizers, surfactants, and thickeners can be used.
  • the method for producing the conductive paste according to the present embodiment is not particularly limited, and a conventionally known method can be used.
  • the conductive paste can be produced, for example, by stirring and kneading each of the above components with a three-roll mill, a ball mill, a mixer or the like.
  • the same effect can be obtained by adding it as a separation inhibitor to the material of.
  • the conductive paste has a viscosity of 100 sec -1 with a shear rate of preferably 3 Pa ⁇ S or less.
  • a shear rate of 100 sec -1 When the viscosity at a shear rate of 100 sec -1 is in the above range, it can be suitably used as a conductive paste for gravure printing. If it exceeds the above range, the viscosity may be too high to be suitable for gravure printing.
  • the lower limit of the viscosity at a shear rate of 100 sec -1 is not particularly limited, but is, for example, 0.2 Pa ⁇ S or more.
  • the conductive paste has a viscosity of 10000 sec -1 and a viscosity of preferably 1 Pa ⁇ S or less.
  • the viscosity at a shear rate of 10000 sec -1 is in the above range, it can be suitably used as a conductive paste for gravure printing. Even if it exceeds the above range, the viscosity may be too high to be suitable for gravure printing.
  • the lower limit of the viscosity at a shear rate of 10000 sec -1 is not particularly limited, but is, for example, 0.05 Pa ⁇ S or more.
  • the content of the additive is preferably less than 3.0% by mass with respect to the entire conductive paste.
  • the content of the additive is 3.0% by mass or more, the drying becomes insufficient in the printing and drying steps, the internal electrode layer becomes soft, and the lamination shift occurs in the subsequent lamination process, or the addition remaining during firing.
  • the agent is vaporized, and the vaporized gas component may generate internal stress, or in the worst case, structural destruction of the laminated body may occur.
  • the thickness of the white floating layer observed one day after the production is preferably less than 5% with respect to the total thickness of the conductive paste, and is preferably 3% or less. It may be 1% or less, or 0%. The smaller the thickness of the white floating layer, the better the separation suppressing effect. The thickness of the white floating layer can be measured by the method described in Examples described later.
  • the conductive paste can be suitably used for electronic parts such as multilayer ceramic capacitors.
  • the multilayer ceramic capacitor has a dielectric layer formed by using a dielectric green sheet and an internal electrode layer formed by using a conductive paste.
  • the coverage of the internal electrode layer may be 75% or more, and may be 80% or more. You may.
  • the laminated ceramic capacitor 1 includes a laminated body 10 in which a dielectric layer 12 and an internal electrode layer 11 are alternately laminated, and an external electrode 20.
  • a method for manufacturing a multilayer ceramic capacitor using the above conductive paste will be described.
  • a conductive paste is printed on a ceramic green sheet (dielectric green sheet) and dried to form a dry film.
  • a plurality of ceramic green sheets having the dry film on the upper surface are laminated by pressure bonding to obtain a laminate, and then the laminate is fired to be integrated, whereby the internal electrode layer 11 and the dielectric layer 12 alternate.
  • a ceramic laminate 10 laminated to the above is produced.
  • the multilayer ceramic capacitor 1 is manufactured by forming a pair of external electrodes at both ends of the ceramic laminate 10. It will be described in more detail below.
  • a ceramic green sheet which is an unfired ceramic sheet.
  • a paste for a dielectric layer obtained by adding an organic binder such as polyvinyl butyral and a solvent such as tarpineol to a predetermined ceramic raw material powder such as barium titanate is used as a PET film or the like.
  • examples thereof include those coated on a support film in the form of a sheet and dried to remove the solvent.
  • the thickness of the dielectric layer made of the ceramic green sheet is not particularly limited, but is preferably 0.05 ⁇ m or more and 3 ⁇ m or less from the viewpoint of requesting miniaturization of the multilayer ceramic capacitor.
  • the above-mentioned conductive paste is printed and applied by using a gravure printing method, and dried to form a plurality of dry films.
  • the thickness of the dried film is preferably 1 ⁇ m or less after drying from the viewpoint of requesting thinning of the internal electrode layer 11.
  • the ceramic green sheet is peeled off from the support film, and the ceramic green sheet and the dry film formed on one side thereof are laminated so as to be alternately arranged, and then a laminated body is obtained by heat / pressure treatment.
  • a protective ceramic green sheet to which the conductive paste is not applied may be further arranged on both sides of the laminate.
  • the green chips are debindered and fired in a reducing atmosphere to obtain a laminated ceramic fired body (ceramic laminate 10).
  • the atmosphere in the binder removal process is preferably in the air or N 2 gas atmosphere.
  • the temperature at which the debinder treatment is performed is, for example, 200 ° C. or higher and 400 ° C. or lower. Further, it is preferable that the holding time of the above temperature is 0.5 hours or more and 24 hours or less when the debinder treatment is performed.
  • the firing is performed in a reducing atmosphere in order to suppress the oxidation of the metal used for the internal electrode layer, and the temperature at which the laminated body is fired is, for example, 1000 ° C. or higher and 1350 ° C. or lower.
  • the temperature holding time is, for example, 0.5 hours or more and 8 hours or less.
  • the organic binder in the green sheet is completely removed, and the ceramic raw material powder is fired to form the ceramic dielectric layer 12. Further, the organic vehicle in the internal electrode layer 11 is removed, and nickel powder or an alloy powder containing nickel as a main component is sintered, melted, and integrated to form an internal electrode, and the dielectric layer 12 and the internal electrode are formed.
  • a laminated ceramic fired body in which a plurality of layers 11 are alternately laminated is formed. From the viewpoint of incorporating oxygen into the dielectric layer to improve reliability and suppressing reoxidation of the internal electrodes, the laminated ceramic fired body after firing may be annealed.
  • the laminated ceramic capacitor 1 is manufactured by providing a pair of external electrodes 20 with respect to the produced laminated ceramic fired body.
  • the external electrode 20 includes an external electrode layer 21 and a plating layer 22.
  • the external electrode layer 21 is electrically connected to the internal electrode layer 11.
  • the material of the external electrode 20 for example, copper, nickel, or an alloy thereof can be preferably used.
  • the electronic component an electronic component other than the monolithic ceramic capacitor can also be used.
  • Viscosity of conductive paste The viscosity of the conductive paste after production was measured using a rheometer (manufactured by Anton Pearl Japan Co., Ltd .: rheometer MCR302). Viscosity, a cone angle of 1 °, by using a cone plate with a diameter of 25 mm, shear rate (shear rate) 100 sec -1, and, using the value measured under the conditions of 10000 sec -1.
  • the conductive paste was printed on a dielectric sheet with a small gravure printing machine (GP-10TYPEII manufactured by Kurashiki Spinning Co., Ltd.) at a coating amount of 0.7 mg / cm 2 of the conductive powder (Ni powder). After that, it was dried in a box-type dryer at 80 ° C. for 4 minutes, taken out, and the dried state of the internal electrode paste was confirmed. The dryness was evaluated as " ⁇ " when it was dry and as "x" when it was not dry.
  • the whitening ratio (%) is calculated by (thickness of the whitening layer / thickness of the total amount of paste) * 100. The percentage of whitening (%) was evaluated as " ⁇ " for less than 5% and "x" for 5% or more.
  • ⁇ Baking conditions> In an atmosphere of N 2 / H 2 , the temperature was raised to 1200 ° C. at a heating rate of 5 ° C./min, and firing was performed at a firing temperature of 1200 ° C. for 0.5 hours.
  • the obtained fired film was photographed at 3000 times using a scanning electron microscope (SEM) (JSM-6360LA, manufactured by JEOL Ltd.), and the area covered by the internal electrodes in the photographed area was measured. , The coverage was calculated. The coverage is calculated by (area covered by the internal electrode) / (photographed area) ⁇ 100. Those having a coverage of 80% or more were evaluated as good ( ⁇ ), and those having a coverage of less than 80% were evaluated as defective (x).
  • SEM scanning electron microscope
  • Ceramic powder As the ceramic powder, barium titanate (BaTIO 3 ; SEM average particle size 0.10 ⁇ m) was used.
  • Binder resin As the binder resin, polyvinyl butyral and ethyl cellulose were used.
  • dicarboxylic acid dicarboxylic acid, comb-shaped carboxylic acid (polycarboxylic acid having a comb-shaped structure), polyethylene oxide, and modified urea were used.
  • an acid-based dispersant and a base-based dispersant were used as the dispersant. Further, a phosphoric acid-based dispersant was used as the acid-based dispersant 1, a comb-type carboxylic acid was used as the acid-based dispersant 2, oleylamine was used as the base-based dispersant 1, and rosinamine was used as the base-based dispersant 2.
  • organic solvent propylene glycol monobutyl ether (PNB), mineral spirit (MA), tarpineol (TPO), and dihydroterpineol (DHT) were used.
  • PNB propylene glycol monobutyl ether
  • MA mineral spirit
  • TPO tarpineol
  • DHT dihydroterpineol
  • Example 1 Conductive powder 50% by mass, ceramic powder 12.5% by mass, dispersant 0.7% by mass (acid-based dispersant 1: 0.4% by mass, basic dispersant 1: 0.3% by mass), dicarboxylic acid 0.1% by mass, 3% by mass of binder resin (1% by mass of polyvinyl butyral resin, 2% by mass of ethyl cellulose), and organic solvent (PNB balance, 13.5% by mass of MA) were added as the balance, and 100% by mass as a whole. These materials were mixed to prepare a conductive paste. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Examples 2, 4-9, 14 A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was changed to the ratio shown in Table 1. By adjusting the amount of PNB added, the conductive paste was adjusted to be 100% by mass. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 3 A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was changed to 0.3% by mass and only the acid-based dispersant 1 was used as the dispersant. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 10 and 11 Except that only the acid-based dispersant 2 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (0.2% by mass, 0.5% by mass), and TPO was used as the organic solvent. , A conductive paste was prepared in the same manner as in Example 1 and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 12 A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was changed to 0.3% by mass and TPO was used as the organic solvent. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 13 A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the dicarboxylic acid was changed to a molecular weight (370) and the content was 0.5% by mass. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 15 The same as in Example 1 except that only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (changed to 0.2% by mass, and PNB was used as the organic solvent).
  • a conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 16 and 17 Except that only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratios shown in Table 1 (0.2% by mass and 0.5% by mass, and TPO was used as the organic solvent).
  • a conductive paste was prepared and evaluated in the same manner as in Example 1. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 18 The dicarboxylic acid was changed to one having a molecular weight (370), only the basic dispersant 1 was used as the dispersant, and the content of the dispersant was changed to the ratio (0.2% by mass) shown in Table 1 as an organic solvent.
  • a conductive paste was prepared and evaluated in the same manner as in Example 1 except that TPO was used. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 19 Same as Example 1 except that only the basic dispersant 2 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (0.6% by mass), and TPO was used as the organic solvent.
  • a conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 20 Same as Example 1 except that only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (0.2% by mass), and DHT was used as the organic solvent.
  • a conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 21 The dicarboxylic acid was changed to one having a molecular weight (370), only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratio (0.2% by mass) shown in Table 1, and the organic solvent was used.
  • a conductive paste was prepared and evaluated in the same manner as in Example 1 except that DHT was used as a binder. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 1 A conductive paste was prepared and evaluated in the same manner as in Example 1 except that a dicarboxylic acid was not used as an additive. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 2 A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was 3% by mass. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Comparative Example 3 A conductive paste was prepared and evaluated in the same manner as in Example 1 except that dicarboxylic acid was not used as an additive and 0.5% by mass of comb-type carboxylic acid was used instead. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • Example 4 Same as Example 1 except that dicarboxylic acid was not used as an additive and instead, 0.5% by mass of polyethylene oxide (Comparative Example 4) and modified urea (Comparative Example 5), which are tixogens, were used.
  • a conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
  • the conductive paste of the example is whiter than the conductive paste of Comparative Example 1 that does not use a dicarboxylic acid or the conductive paste of Comparative Example 3 that uses a comb-shaped carboxylic acid instead of the dicarboxylic acid. Occurrence is suppressed and a high coverage is exhibited when the internal electrode layer is formed.
  • the dicarboxylic acid is contained and the dispersant is added to the total conductive paste in an amount of 0.6% by mass or less, or 0.5. Even when it contains less than mass%, a high separation suppressing effect can be obtained.
  • the conductive paste of Comparative Example 2 containing 3.0% by mass of dicarboxylic acid was not dried in the drying property evaluation, and cracks may occur when forming the internal electrode layer.
  • the conductive paste of the present invention has a viscosity suitable for gravure printing, and the separation of the conductive powder and the ceramic powder is greatly suppressed, and when an internal electrode is formed, it is uniformly formed on the dielectric layer. Can be coated. Therefore, the conductive paste of the present invention can be suitably used as a raw material for an internal electrode of a multilayer ceramic capacitor, which is a chip component of an electronic device such as a mobile phone or a digital device, which is becoming smaller and smaller, and is used for gravure printing. It can be suitably used as a conductive paste.
  • Multilayer ceramic capacitor 10 Ceramic laminate 11 Internal electrode layer 12 Dielectric layer 20 External electrode 21 External electrode layer 22 Plating layer

Abstract

Provided is a conductive paste for gravure printing in which separation of a conductive powder and a ceramic powder is extremely suppressed. This conductive paste for gravure printing contains a conductive powder, a ceramic powder, an additive, a binder resin, and an organic solvent, wherein the additive contains a dicarboxylic acid and a dispersant other than a dicarboxylic acid, the contained amount of the dicarboxylic acid with respect to the total of the conductive paste is not less than 0.1 mass% but less than 3.0 mass%.

Description

グラビア印刷用導電性ペースト、電子部品、及び積層セラミックコンデンサConductive paste for gravure printing, electronic components, and monolithic ceramic capacitors
　本発明は、グラビア印刷用導電性ペースト、電子部品、及び積層セラミックコンデンサに関する。 The present invention relates to a conductive paste for gravure printing, electronic components, and a multilayer ceramic capacitor.
　携帯電話やデジタル機器などの電子機器の小型化および高性能化に伴い、積層セラミックコンデンサなどを含む電子部品についても小型化および高容量化が望まれている。積層セラミックコンデンサは、複数の誘電体層と複数の内部電極層とが交互に積層した構造を有し、これらの誘電体層及び内部電極層を薄膜化することにより、小型化及び高容量化を図ることができる。 Along with the miniaturization and high performance of electronic devices such as mobile phones and digital devices, it is desired to reduce the size and capacity of electronic components including multilayer ceramic capacitors. A multilayer ceramic capacitor has a structure in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately laminated, and by thinning these dielectric layers and internal electrode layers, miniaturization and high capacity can be achieved. Can be planned.
　積層セラミックコンデンサは、例えば、次のように製造される。まず、チタン酸バリウム（ＢａＴｉＯ３）などの誘電体粉末及びバインダー樹脂を含有する誘電体グリーンシートの表面上に、導電性粉末、バインダー樹脂、及び、有機溶剤などを含む内部電極用ペースト（導電性ペースト）を、所定の電極パターンで印刷したものを、多層に積み重ねることにより、積層体を得る。次に、この積層体を加熱圧着して一体化し、圧着体を形成する。この圧着体を切断し、酸化性雰囲気または不活性雰囲気中にて脱有機バインダー処理を行った後、焼成を行い、焼成チップを得る。次いで、焼成チップの両端部に外部電極用ペーストを塗布し、焼成後、外部電極表面にニッケルメッキなどを施して、積層セラミックコンデンサが得られる。 Multilayer ceramic capacitors are manufactured, for example, as follows. First, a paste for an internal electrode (conductive) containing a conductive powder, a binder resin, an organic solvent, and the like on the surface of a dielectric green sheet containing a dielectric powder such as barium titanate (BaTIO 3 ) and a binder resin. A laminated body is obtained by stacking a paste) printed with a predetermined electrode pattern in multiple layers. Next, the laminated body is heat-bonded and integrated to form a pressure-bonded body. The pressure-bonded body is cut and subjected to a deorganizing binder treatment in an oxidizing atmosphere or an inert atmosphere, and then fired to obtain a fired chip. Next, pastes for external electrodes are applied to both ends of the fired chip, and after firing, the surface of the external electrodes is nickel-plated or the like to obtain a multilayer ceramic capacitor.
　導電性ペーストを誘電体グリーンシートに印刷する際に用いられる印刷法としては、従来、スクリーン印刷法が一般的に用いられてきたが、電子デバイスの小型化、薄膜化や生産性向上の要求から、より微細な電極パターンを生産性高く印刷することが求められている。 Conventionally, a screen printing method has been generally used as a printing method used when printing a conductive paste on a dielectric green sheet, but due to the demand for miniaturization, thinning, and productivity improvement of electronic devices. , It is required to print finer electrode patterns with high productivity.
　導電性ペーストの印刷法の一つとして、製版に設けられた凹部に導電性ペーストを充填し、これを被印刷面に押し当てることでその製版から導電性ペーストを転写する連続印刷法であるグラビア印刷法が提案されている。グラビア印刷法は印刷速度が速く、生産性に優れる。グラビア印刷法を用いる場合、導電性ペースト中のバインダー樹脂、分散剤、溶剤等を適宜選択して、粘度等の特性をグラビア印刷に適した範囲に調整する必要がある。 As one of the printing methods of the conductive paste, gravure is a continuous printing method in which the concave portion provided in the plate making is filled with the conductive paste and pressed against the surface to be printed to transfer the conductive paste from the plate making. A printing method has been proposed. The gravure printing method has a high printing speed and is excellent in productivity. When the gravure printing method is used, it is necessary to appropriately select the binder resin, dispersant, solvent, etc. in the conductive paste and adjust the characteristics such as viscosity within a range suitable for gravure printing.
　例えば、特許文献１では、複数のセラミック層および前記セラミック層間の特定の界面に沿って延びる内部導体膜を備える積層セラミック電子部品における前記内部導体膜をグラビア印刷によって形成するために用いられる導電性ペーストであって、金属粉末を含む３０～７０重量％の固形成分と、１～１０重量％のエトキシ基含有率が４９．６％以上のエチルセルロース樹脂成分と、０．０５～５重量％の分散剤と、残部としての溶剤成分とを含み、ずり速度０．１（ｓ－１）での粘度η０．１が１Ｐａ・ｓ以上であり、かつずり速度０．０２（ｓ－１）での粘度η０．０２が特定の式で表わされる条件を満たす、チキソトロピー流体である、導電性ペーストが記載されている。 For example, in Patent Document 1, a conductive paste used for forming the inner conductor film in a laminated ceramic electronic component including a plurality of ceramic layers and an inner conductor film extending along a specific interface between the ceramic layers by gravure printing. A solid component of 30 to 70% by weight containing a metal powder, an ethyl cellulose resin component having an ethoxy group content of 1 to 10% by weight of 49.6% or more, and a dispersant of 0.05 to 5% by weight. And the solvent component as the balance, the viscosity η 0.1 at a shear rate of 0.1 (s -1 ) is 1 Pa · s or more, and the viscosity at a shear rate of 0.02 (s -1 ). Described are conductive pastes that are thixotropy fluids that satisfy the condition that η 0.02 is expressed by a particular equation.
　また、特許文献２では、上記特許文献１と同様にグラビア印刷によって形成するために用いられる導電性ペーストであって、金属粉末を含む３０～７０重量％の固形成分と、１～１０重量％の樹脂成分と、０．０５～５重量％の分散剤と、残部としての溶剤成分とを含み、ずり速度０．１（ｓ－１）での粘度が１Ｐａ・ｓ以上のチキソトロピー流体であって、ずり速度０．１（ｓ－１）での粘度を基準としたときに、ずり速度１０（ｓ－１）での粘度変化率が５０％以上である、導電性ペーストが記載されている。 Further, in Patent Document 2, a conductive paste used for forming by gravure printing as in Patent Document 1, wherein 30 to 70% by weight of a solid component containing a metal powder and 1 to 10% by weight of a solid component are used. A thixotropy fluid containing a resin component, a dispersant of 0.05 to 5% by weight, and a solvent component as a balance, and having a viscosity of 1 Pa · s or more at a shear rate of 0.1 (s -1 ). Described are conductive pastes having a viscosity change rate of 50% or more at a shear rate of 10 (s -1 ), based on the viscosity at a shear rate of 0.1 (s -1 ).
　上記特許文献１、２によれば、これらの導電性ペーストは、ずり速度０．１（ｓ－１）での粘度が１Ｐａ・ｓ以上であるチキソトロピー流体であり、グラビア印刷において高速での安定した連続印刷性が得られ、良好な生産効率をもって、積層セラミックコンデンサのような積層セラミック電子部品を製造することができるとされている。 According to Patent Documents 1 and 2, these conductive pastes are thixotropy fluids having a viscosity of 1 Pa · s or more at a shear rate of 0.1 (s -1 ), and are stable at high speed in gravure printing. It is said that continuous printability can be obtained and laminated ceramic electronic components such as multilayer ceramic capacitors can be manufactured with good production efficiency.
　また、特許文献３には、導電性粉末（Ａ）、有機樹脂（Ｂ）、及び有機溶剤（Ｃ）、添加剤（Ｄ）、及び誘電体粉末（Ｅ）を含む積層セラミックコンデンサ内部電極用導電性ペーストであって、有機樹脂（Ｂ）は、重合度が１００００以上５００００以下のポリビニルブチラールと、重量平均分子量が１００００以上１０００００以下のエチルセルロースからなり、有機溶剤（Ｃ）は、プロピレングリコールモノブチルエーテル、もしくはプロピレングリコールモノブチルエーテルとプロピレングリコールメチルエーテルアセテートの混合溶剤、又はプロピレングリコールモノブチルエーテルとミネラルスピリットの混合溶剤のいずれかからなり、添加剤（Ｄ）は、分離抑制剤と分散剤からなり、該分離抑制剤としてポリカルボン酸ポリマーもしくはポリカルボン酸の塩を含む組成物からなるグラビア印刷用導電性ペーストが記載されている。特許文献３によれば、この導電性ペーストは、グラビア印刷に適した粘度を有し、ペーストの均一性・安定性が向上し、かつ、乾燥性がよいとされている。 Further, Patent Document 3 describes conductivity for an internal electrode of a multilayer ceramic capacitor containing a conductive powder (A), an organic resin (B), an organic solvent (C), an additive (D), and a dielectric powder (E). The organic resin (B) is a sex paste composed of polyvinyl butyral having a degree of polymerization of 10,000 or more and 50,000 or less and ethyl cellulose having a weight average molecular weight of 10,000 or more and 100,000 or less, and the organic solvent (C) is propylene glycol monobutyl ether. Alternatively, it is composed of either a mixed solvent of propylene glycol monobutyl ether and propylene glycol methyl ether acetate, or a mixed solvent of propylene glycol monobutyl ether and mineral spirit, and the additive (D) is composed of a separation inhibitor and a dispersant, and the separation thereof. A conductive paste for gravure printing, which comprises a composition containing a polycarboxylic acid polymer or a salt of polycarboxylic acid as an inhibitor, is described. According to Patent Document 3, this conductive paste has a viscosity suitable for gravure printing, the uniformity and stability of the paste are improved, and the drying property is good.
特開２００３－１８７６３８号公報Japanese Unexamined Patent Publication No. 2003-187638 特開２００３－２４２８３５号公報Japanese Unexamined Patent Publication No. 2003-242835 特開２０１２－１７４７９７号公報Japanese Unexamined Patent Publication No. 2012-174977
　グラビア印刷用の導電性ペーストでは、低粘度であることが要求される。しかしながら、低粘度の導電性ペーストでは、スクリーン印刷用などの高粘度の導電性ペーストと比較して、チタン酸バリウムなどのセラミック粉末とＮｉなどの導電性粉末とを添加した際に、これらの粉末の比重差による沈降速度差がより顕著に影響して、導電性粉末とセラミック粉末とが分離しやすい。 The conductive paste for gravure printing is required to have a low viscosity. However, in the low-viscosity conductive paste, when the ceramic powder such as barium titanate and the conductive powder such as Ni are added, these powders are compared with the high-viscosity conductive paste for screen printing and the like. The difference in settling speed due to the difference in specific gravity has a more remarkable effect, and the conductive powder and the ceramic powder are easily separated.
　例えば、グラビア印刷用の導電性ペーストでは、導電性ペーストを作製した際にセラミック粉末を含む白い分離層が上部に発生する「白浮き」と称する現象（二層分離）が生じることがある。 For example, in a conductive paste for gravure printing, a phenomenon called "whitening" (two-layer separation) may occur in which a white separation layer containing ceramic powder is generated at the upper part when the conductive paste is produced.
　また、本発明者が検討した結果、導電性ペーストにおいてセラミック粉末が偏析した場合、「白浮き」が生じるだけでなく、内部電極層を形成する際の焼結時にセラミック粉末の焼結遅延効果が局所的になってしまい、内部電極層を形成した際の被覆率が減少するという問題があることを見出した。導電性粉末とセラミック粉末とが分離した導電性ペーストでは、焼結の際に内部電極層の収縮速度に部分的な差が生じるため、内部電極層の被覆率が減少すると考えられる。 Further, as a result of the study by the present inventor, when the ceramic powder segregates in the conductive paste, not only "whitening" occurs, but also the sintering delay effect of the ceramic powder during sintering when forming the internal electrode layer is exhibited. It has been found that there is a problem that the coverage becomes local and the coverage when the internal electrode layer is formed decreases. In the conductive paste in which the conductive powder and the ceramic powder are separated, it is considered that the coverage of the internal electrode layer is reduced because the shrinkage rate of the internal electrode layer is partially different during sintering.
　本発明は、このような状況に鑑み、グラビア印刷に適した低いペースト粘度を有し、かつ、導電性粉末とセラミック粉末との分離を抑制することができる、導電性ペーストを提供することを目的とする。 In view of such a situation, it is an object of the present invention to provide a conductive paste having a low paste viscosity suitable for gravure printing and capable of suppressing separation between a conductive powder and a ceramic powder. And.
　本発明の第１の態様では、導電性粉末、セラミック粉末、添加剤、バインダー樹脂及び有機溶剤を含むグラビア印刷用導電性ペーストであって、添加剤は、ジカルボン酸と、ジカルボン酸以外の分散剤とを含み、ジカルボン酸を、導電性ペースト全体に対して０．１質量％以上３．０質量％未満含む、グラビア印刷用導電性ペーストが提供される。 In the first aspect of the present invention, the conductive paste for gravure printing contains a conductive powder, a ceramic powder, an additive, a binder resin and an organic solvent, and the additive is a dicarboxylic acid and a dispersant other than the dicarboxylic acid. Provided is a conductive paste for gravure printing, which comprises, and contains a dicarboxylic acid in an amount of 0.1% by mass or more and less than 3.0% by mass based on the entire conductive paste.
　また、分散剤は、導電性ペースト全体に対して０．０１質量％以上３．０質量％以下含有されることが好ましい。また、分散剤は、酸系分散剤及び塩基系分散剤のうちの一方、又は、両方を含むことが好ましい。また、導電性粉末は、Ｎｉ、Ｐｄ、Ｐｔ、Ａｕ、Ａｇ、Ｃｕ及びこれらの合金から選ばれる少なくとも１種の金属粉末を含むことが好ましい。また、導電性粉末は、平均粒径が０．０５μｍ以上１．０μｍ以下であることが好ましい。また、セラミック粉末は、チタン酸バリウムを含むことが好ましい。また、セラミック粉末は、平均粒径が０．０１μｍ以上０．５μｍ以下であることが好ましい。また、セラミック粉末は、導電性ペースト全体に対して１質量％以上２０質量％以下含まれることが好ましい。また、バインダー樹脂が、セルロース系樹脂を含むことが好ましい。また、積層セラミック部品の内部電極用である請求項１～９のいずれか一項に記載のグラビア印刷用導電性ペースト。また、ずり速度１００ｓｅｃ－１での粘度が３Ｐａ・Ｓ以下であり、ずり速度１００００ｓｅｃ－１での粘度が１Ｐａ・Ｓ以下であることが好ましい。 Further, the dispersant is preferably contained in an amount of 0.01% by mass or more and 3.0% by mass or less with respect to the entire conductive paste. Further, the dispersant preferably contains one or both of an acid-based dispersant and a basic-based dispersant. Further, the conductive powder preferably contains at least one metal powder selected from Ni, Pd, Pt, Au, Ag, Cu and alloys thereof. Further, the conductive powder preferably has an average particle size of 0.05 μm or more and 1.0 μm or less. Further, the ceramic powder preferably contains barium titanate. The ceramic powder preferably has an average particle size of 0.01 μm or more and 0.5 μm or less. Further, the ceramic powder is preferably contained in an amount of 1% by mass or more and 20% by mass or less with respect to the entire conductive paste. Moreover, it is preferable that the binder resin contains a cellulosic resin. The conductive paste for gravure printing according to any one of claims 1 to 9, which is used for an internal electrode of a laminated ceramic component. The viscosity at shear rate 100 sec -1 is not higher than 3 Pa · S, it is preferable that the viscosity at a shear rate 10000 sec -1 is less than 1 Pa · S.
　本発明の第２の態様では、上記の導電性ペーストを用いて形成された電子部品が提供される。 In the second aspect of the present invention, an electronic component formed by using the above conductive paste is provided.
　本発明の第３の態様では、誘電体層と内部電極層とを積層した積層体を少なくとも有し、内部電極層は、上記のグラビア印刷用導電性ペーストを用いて形成された積層セラミックコンデンサが提供される。 In the third aspect of the present invention, at least a laminated body in which a dielectric layer and an internal electrode layer are laminated is provided, and the internal electrode layer is a laminated ceramic capacitor formed by using the above-mentioned conductive paste for gravure printing. Provided.
　本発明の導電性ペーストは、グラビア印刷に適した特性を有し、低粘度のペースト中においても、導電性粉末とセラミック粉末との分離を抑制することができ、薄膜化した電極を形成する際も印刷性に優れる。また、本発明の導電性ペーストを用いて形成される内部電極層は、薄膜化した際も、誘電体層上を均一に被覆することができる。 The conductive paste of the present invention has properties suitable for gravure printing, can suppress the separation of the conductive powder and the ceramic powder even in a low-viscosity paste, and when forming a thinned electrode. Also has excellent printability. Further, the internal electrode layer formed by using the conductive paste of the present invention can uniformly cover the dielectric layer even when it is thinned.
図１Ａ及び図１Ｂは、実施形態に係る積層セラミックコンデンサを示す斜視図（図１Ａ）及び断面図（図１Ｂ）である。1A and 1B are a perspective view (FIG. 1A) and a cross-sectional view (FIG. 1B) showing the multilayer ceramic capacitor according to the embodiment.
［導電性ペースト］
　本実施形態の導電性ペーストは、導電性粉末、セラミック粉末、添加剤、バインダー樹脂及び有機溶剤を含む。以下、各成分について詳細に説明する。 [Conductive paste]
The conductive paste of this embodiment contains a conductive powder, a ceramic powder, an additive, a binder resin and an organic solvent. Hereinafter, each component will be described in detail.
（導電性粉末）
　導電性粉末としては、特に限定されず、金属粉末を用いることができ、例えば、Ｎｉ、Ｐｄ、Ｐｔ、Ａｕ、Ａｇ、Ｃｕ、およびこれらの合金から選ばれる１種以上の粉末を用いることができる。これらの中でも、導電性、耐食性及びコストの観点から、Ｎｉ、またはその合金（Ｎｉ合金）の粉末が好ましい。Ｎｉ合金としては、例えば、Ｍｎ、Ｃｒ、Ｃｏ、Ａｌ、Ｆｅ、Ｃｕ、Ｚｎ、Ａｇ、Ａｕ、ＰｔおよびＰｄからなる群より選択される少なくとも１種以上の元素とＮｉとの合金が用いることができる。Ｎｉ合金におけるＮｉの含有量は、例えば、５０質量％以上、好ましくは８０質量％以上である。また、Ｎｉ粉末は、脱バインダー処理の際、バインダー樹脂の部分的な熱分解による急激なガス発生を抑制するために、数百ｐｐｍ程度の元素Ｓを含んでもよい。 (Conductive powder)
The conductive powder is not particularly limited, and a metal powder can be used. For example, Ni, Pd, Pt, Au, Ag, Cu, and one or more powders selected from these alloys can be used. .. Among these, Ni or its alloy (Ni alloy) powder is preferable from the viewpoint of conductivity, corrosion resistance and cost. As the Ni alloy, for example, an alloy of at least one element selected from the group consisting of Mn, Cr, Co, Al, Fe, Cu, Zn, Ag, Au, Pt and Pd and Ni can be used. it can. The content of Ni in the Ni alloy is, for example, 50% by mass or more, preferably 80% by mass or more. Further, the Ni powder may contain an element S of about several hundred ppm in order to suppress abrupt gas generation due to partial thermal decomposition of the binder resin during the debinder treatment.
　導電性粉末の平均粒径は、好ましくは０．０５μｍ以上１．０μｍ以下であり、より好ましくは０．１μｍ以上０．５μｍ以下である。導電性粉末の平均粒径が上記範囲である場合、薄膜化した積層セラミックコンデンサ（積層セラミック部品）の内部電極用ペーストとして好適に用いることができ、例えば、乾燥膜の平滑性及び乾燥膜密度が向上する。平均粒径は、走査型電子顕微鏡（ＳＥＭ）による観察から求められる値であり、ＳＥＭで倍率１０，０００倍にて観察した画像から、複数の粒子一つ一つの粒径を測定して、得られる平均値（ＳＥＭ平均粒径）である。 The average particle size of the conductive powder is preferably 0.05 μm or more and 1.0 μm or less, and more preferably 0.1 μm or more and 0.5 μm or less. When the average particle size of the conductive powder is within the above range, it can be suitably used as a paste for an internal electrode of a thinned laminated ceramic capacitor (laminated ceramic component). For example, the smoothness of the dried film and the density of the dried film are high. improves. The average particle size is a value obtained from observation with a scanning electron microscope (SEM), and is obtained by measuring the particle size of each of a plurality of particles from an image observed with an SEM at a magnification of 10,000 times. It is an average value (SEM average particle diameter) to be obtained.
　導電性粉末の含有量は、導電性ペースト全体に対して、好ましくは３０質量％以上７０質量％未満であり、より好ましくは４０質量％以上６０質量％以下である。導電性粉末の含有量が上記範囲である場合、導電性及び分散性に優れる。 The content of the conductive powder is preferably 30% by mass or more and less than 70% by mass, and more preferably 40% by mass or more and 60% by mass or less with respect to the entire conductive paste. When the content of the conductive powder is within the above range, the conductivity and dispersibility are excellent.
（セラミック粉末）
　セラミック粉末としては、特に限定されず、例えば、積層セラミックコンデンサの内部電極用ペーストである場合、適用する積層セラミックコンデンサの種類により適宜、公知のセラミック粉末が選択される。セラミック粉末としては、例えば、Ｂａ及びＴｉを含むペロブスカイト型酸化物を用いることができ、好ましくはチタン酸バリウム（ＢａＴｉＯ３）を含む。 (Ceramic powder)
The ceramic powder is not particularly limited, and for example, in the case of a paste for an internal electrode of a multilayer ceramic capacitor, a known ceramic powder is appropriately selected depending on the type of the laminated ceramic capacitor to be applied. As the ceramic powder, for example, a perovskite-type oxide containing Ba and Ti can be used, and barium titanate (BaTIO 3 ) is preferably contained.
　セラミック粉末としては、チタン酸バリウムを主成分とし、酸化物を副成分として含むセラミック粉末を用いてもよい。酸化物としては、Ｍｎ、Ｃｒ、Ｓｉ、Ｃａ、Ｂａ、Ｍｇ、Ｖ、Ｗ、Ｔａ、Ｎｂおよび希土類元素から選ばれる１種以上の酸化物が挙げられる。このようなセラミック粉末としては、例えば、チタン酸バリウム（ＢａＴｉＯ３）のＢａ原子やＴｉ原子を他の原子、例えば、Ｓｎ、Ｐｂ、Ｚｒなどで置換したペロブスカイト型酸化物強誘電体のセラミック粉末が挙げられる。 As the ceramic powder, a ceramic powder containing barium titanate as a main component and an oxide as a sub component may be used. Examples of the oxide include one or more oxides selected from Mn, Cr, Si, Ca, Ba, Mg, V, W, Ta, Nb and rare earth elements. Examples of such ceramic powders include ceramic powders of perovskite-type oxide ferroelectrics in which the Ba atom or Ti atom of barium titanate (BaTIO 3 ) is replaced with another atom, for example, Sn, Pb, Zr or the like. Can be mentioned.
　内部電極用の導電性ペーストに用いるセラミック粉末は、積層セラミックコンデンサ（電子部品）のグリーンシートを構成する誘電体セラミック粉末と同一組成の粉末を用いてもよい。これにより、焼結工程における誘電体層と内部電極層との界面での収縮のミスマッチによるクラック発生が抑制される。このようなセラミック粉末としては、上記Ｂａ及びＴｉを含むペロブスカイト型酸化物以外に、例えば、ＺｎＯ、フェライト、ＰＺＴ、ＢａＯ、Ａｌ２Ｏ３、Ｂｉ２Ｏ３、Ｒ（希土類元素）２Ｏ３、ＴｉＯ２、Ｎｄ２Ｏ３などの酸化物が挙げられる。なお、セラミック粉末は、１種類を用いてもよく、２種類以上を用いてもよい。 As the ceramic powder used for the conductive paste for the internal electrode, a powder having the same composition as the dielectric ceramic powder constituting the green sheet of the multilayer ceramic capacitor (electronic component) may be used. As a result, the generation of cracks due to the shrinkage mismatch at the interface between the dielectric layer and the internal electrode layer in the sintering process is suppressed. Such ceramic powders include, for example, ZnO, ferrite, PZT, BaO, Al 2 O 3 , Bi 2 O 3 , R (rare earth element) 2 O 3 , in addition to the perovskite oxide containing Ba and Ti. Oxides such as TiO 2 and Nd 2 O 3 can be mentioned. As the ceramic powder, one type may be used, or two or more types may be used.
　セラミック粉末の平均粒径は、例えば、０．０１μｍ以上０．５μｍ以下であり、好ましくは０．０１μｍ以上０．３μｍ以下の範囲である。セラミック粉末の平均粒径が上記範囲であることにより、内部電極用ペーストとして用いた場合、十分に細く薄い均一な内部電極を形成することができる。平均粒径は、走査型電子顕微鏡（ＳＥＭ）による観察から求められる値であり、ＳＥＭで倍率５０，０００倍にて観察した映像から、複数の粒子一つ一つの粒径を測定して、得られる平均値（ＳＥＭ平均粒径）である。 The average particle size of the ceramic powder is, for example, 0.01 μm or more and 0.5 μm or less, preferably 0.01 μm or more and 0.3 μm or less. When the average particle size of the ceramic powder is in the above range, it is possible to form a sufficiently thin and thin uniform internal electrode when used as a paste for an internal electrode. The average particle size is a value obtained from observation with a scanning electron microscope (SEM), and is obtained by measuring the particle size of each of a plurality of particles from an image observed with an SEM at a magnification of 50,000 times. It is an average value (SEM average particle diameter) to be obtained.
　セラミック粉末の含有量は、導電性ペースト全体に対して、好ましくは１質量％以上２０質量％以下であり、より好ましくは３質量％以上１５質量％以下である。セラミック粉末の含有量が上記範囲である場合、分散性および焼結性に優れる。 The content of the ceramic powder is preferably 1% by mass or more and 20% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire conductive paste. When the content of the ceramic powder is in the above range, the dispersibility and sinterability are excellent.
　また、セラミック粉末の含有量は、導電性粉末１００質量部に対して、好ましくは１質量部以上３０質量部以下であり、より好ましくは３質量部以上３０質量部以下である。 The content of the ceramic powder is preferably 1 part by mass or more and 30 parts by mass or less, and more preferably 3 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the conductive powder.
（バインダー樹脂）
　バインダー樹脂としては、特に限定されず、公知の樹脂を用いることができる。バインダー樹脂としては、例えば、メチルセルロース、エチルセルロース、エチルヒドロキシエチルセルロース、ニトロセルロースなどのセルロース系樹脂、アクリル系樹脂、ポリビニルブチラールなどのブチラール系樹脂を含むアセタール系樹脂などが挙げられる。中でも、溶剤への溶解性、燃焼分解性の観点などから、セルロース系樹脂を含むことが好ましく、エチルセルロースを含むことがより好ましい。また、内部電極用ペーストとして用いる場合、グリーンシートとの接着強度を向上させる観点から、ブチラール系樹脂を含む、又は、ブチラール系樹脂単独で使用してもよい。バインダー樹脂がアセタール系樹脂を含む場合、グラビア印刷に適した粘度に容易に調整することができ、かつ、グリーンシートとの接着強度をより向上させることができる。バインダー樹脂は、例えば、バインダー樹脂全体に対して、アセタール系樹脂を２０質量％以上含んでもよく、３０質量％以上含んでもよい。また、バインダー樹脂は、バインダー樹脂全体に対して、アセタール系樹脂を８０質量％以下含んでもよい。 (Binder resin)
The binder resin is not particularly limited, and a known resin can be used. Examples of the binder resin include cellulosic resins such as methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose and nitrocellulose, acrylic resins, and acetal resins containing butyral resins such as polyvinyl butyral. Above all, from the viewpoint of solubility in a solvent, combustion decomposition, and the like, it is preferable to contain a cellulosic resin, and more preferably ethyl cellulose is contained. When used as a paste for an internal electrode, it may contain a butyral resin or may be used alone from the viewpoint of improving the adhesive strength with the green sheet. When the binder resin contains an acetal resin, the viscosity can be easily adjusted to be suitable for gravure printing, and the adhesive strength with the green sheet can be further improved. The binder resin may contain, for example, 20% by mass or more of the acetal resin or 30% by mass or more of the total binder resin. Further, the binder resin may contain 80% by mass or less of the acetal-based resin with respect to the entire binder resin.
　バインダー樹脂の重合度や重量平均分子量は、要求される導電性ペーストの粘度に応じて、上記範囲内で適宜調整することができる。 The degree of polymerization and weight average molecular weight of the binder resin can be appropriately adjusted within the above range according to the required viscosity of the conductive paste.
　バインダー樹脂の含有量は、導電性ペースト全体に対して、好ましくは０．５質量％以上１０質量％以下であり、より好ましくは１質量％以上７質量％以下である。バインダー樹脂の含有量が上記範囲である場合、導電性及び分散性に優れる。 The content of the binder resin is preferably 0.5% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 7% by mass or less with respect to the entire conductive paste. When the content of the binder resin is within the above range, the conductivity and dispersibility are excellent.
　バインダー樹脂の含有量は、導電性粉末１００質量部に対して、好ましくは１質量部以上２０質量部以下であり、より好ましくは１質量部以上１４質量部以下である。 The content of the binder resin is preferably 1 part by mass or more and 20 parts by mass or less, and more preferably 1 part by mass or more and 14 parts by mass or less with respect to 100 parts by mass of the conductive powder.
（有機溶剤）
　有機溶剤としては、特に限定されず、上記バインダー樹脂を溶解することができる公知の有機溶剤を用いることができる。有機溶剤としては、例えば、グリコールエーテル系溶剤、アセテート系溶剤、酢酸エステル系溶剤、ケトン系溶剤、テルペン系溶剤、脂肪族系炭化水素溶剤などが挙げられる。なお、有機溶剤は、１種類を用いてもよく、２種類以上を用いてもよい。 (Organic solvent)
The organic solvent is not particularly limited, and a known organic solvent capable of dissolving the binder resin can be used. Examples of the organic solvent include glycol ether-based solvent, acetate-based solvent, acetic acid ester-based solvent, ketone-based solvent, terpene-based solvent, aliphatic hydrocarbon solvent and the like. As the organic solvent, one type may be used, or two or more types may be used.
　グリコールエーテル系溶剤としては、例えば、ジエチレングリコールモノ－２－エチルヘキシルエーテル、エチレングリコールモノ－２－エチルヘキシルエーテル、ジエチレングリコールモノヘキシルエーテル、エチレングリコールモノヘキシルエーテルなどの（ジ）エチレングリコールエーテル類、及び、プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、プロピレングリコールモノプロピルエーテル、プロピレングリコールモノブチルエーテル（ＰＮＢ）などのプロピレングリコールモノアルキルエーテル類などが挙げられる。中でも、プロピレングリコールモノアルキルエーテル類が好ましく、プロピレングリコールモノブチルエーテル（ＰＮＢ）がより好ましい。有機溶剤がグリコールエーテル系溶剤を含む場合、上述したバインダー樹脂との相溶性に優れ、かつ、乾燥性に優れる。 Examples of the glycol ether-based solvent include (di) ethylene glycol ethers such as diethylene glycol mono-2-ethylhexyl ether, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol monohexyl ether, and ethylene glycol monohexyl ether, and propylene glycol. Examples thereof include propylene glycol monoalkyl ethers such as monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether (PNB). Of these, propylene glycol monoalkyl ethers are preferable, and propylene glycol monobutyl ether (PNB) is more preferable. When the organic solvent contains a glycol ether solvent, it has excellent compatibility with the above-mentioned binder resin and excellent drying property.
　有機溶剤は、例えば、有機溶剤全体に対し、グリコールエーテル系溶剤を２５質量％以上含んでもよく、５０質量％以上含んでもよく、グリコールエーテル系溶剤のみからなってもよい。また、グリコールエーテル系溶剤は、１種単独で用いてもよく、２種以上を併用してもよい。 The organic solvent may contain, for example, 25% by mass or more of the glycol ether solvent, 50% by mass or more, or only the glycol ether solvent with respect to the entire organic solvent. Further, the glycol ether solvent may be used alone or in combination of two or more.
　アセテート系溶剤としては、例えば、ジヒドロターピニルアセテート、イソボルニルアセテート、イソボルニルプロピネート、イソボルニルブチレート、イソボルニルイソブチレートや、エチレングリコールモノブチルエーテルアセテート、ジプロピレングリコールメチルエーテルアセテート、３－メトキシー３－メチルブチルアセテート、１－メトキシプロピル－２－アセテートなどのグリコールエーテルアセテート類などが挙げられる。 Examples of the acetate solvent include dihydroterpinyl acetate, isobornyl acetate, isobornyl propinate, isobornyl butyrate, isobornyl isobutyrate, ethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether. Examples thereof include glycol ether acetates such as acetate, 3-methoxy-3-methylbutyl acetate and 1-methoxypropyl-2-acetate.
　また、酢酸エステル系溶剤としては、例えば、酢酸エチル、酢酸プロピル、酢酸イソブチル、酢酸ブチルなどが挙げられる。ケトン系溶剤としては、メチルエチルケトン、メチルイソブチルケトンなどが挙げられる。また、テルペン系溶剤としては、ターピネオール（ＴＰＯ）、ジヒドロターピネオール（ＤＨＴ）などが挙げられ、中でも、内部電極層の被覆率を向上させるという観点から、ジヒドロターピネオール（ＤＨＴ）が好ましい。脂肪族系炭化水素溶剤としては、トリデカン、ノナン、シクロヘキサンなどが挙げられ、中でも、ミネラルスピリット（ＭＡ）がより好ましい。 Examples of the acetic acid ester solvent include ethyl acetate, propyl acetate, isobutyl acetate, and butyl acetate. Examples of the ketone solvent include methyl ethyl ketone and methyl isobutyl ketone. Examples of the terpene-based solvent include tarpineol (TPO) and dihydroterpineol (DHT). Among them, dihydroterpineol (DHT) is preferable from the viewpoint of improving the coverage of the internal electrode layer. Examples of the aliphatic hydrocarbon solvent include tridecane, nonane, cyclohexane and the like, and among them, mineral spirit (MA) is more preferable.
　有機溶剤は、例えば、有機溶剤全体に対し、テルペン系溶剤を２５質量％以上含んでもよく、５０質量％以上含んでもよく、テルペン系溶剤のみからなってもよい。また、テルペン系溶剤は、１種単独で用いてもよく、２種以上を併用してもよい。 The organic solvent may contain, for example, 25% by mass or more of the terpene solvent, 50% by mass or more, or only the terpene solvent with respect to the entire organic solvent. Further, the terpene solvent may be used alone or in combination of two or more.
　有機溶剤の含有量は、導電性ペースト全量に対して、２０質量％以上５０質量％以下が好ましく、２５質量％以上４５質量％以下がより好ましい。有機溶剤の含有量が上記範囲である場合、導電性及び分散性に優れる。 The content of the organic solvent is preferably 20% by mass or more and 50% by mass or less, and more preferably 25% by mass or more and 45% by mass or less with respect to the total amount of the conductive paste. When the content of the organic solvent is in the above range, the conductivity and dispersibility are excellent.
　有機溶剤の含有量は、導電性粉末１００質量部に対して、好ましくは５０質量部以上１３０質量部以下であり、より好ましくは６０質量部以上９０質量部以下である。有機溶剤の含有量が上記範囲である場合、導電性及び分散性に優れる。 The content of the organic solvent is preferably 50 parts by mass or more and 130 parts by mass or less, and more preferably 60 parts by mass or more and 90 parts by mass or less with respect to 100 parts by mass of the conductive powder. When the content of the organic solvent is in the above range, the conductivity and dispersibility are excellent.
　有機溶剤は、例えば、主溶剤としてグリコールエーテル系溶剤を含み、副溶剤として脂肪族系炭化水素溶剤を含むことができる。この場合、グリコールエーテル系溶剤は、導電性粉末１００質量部に対して、好ましくは３０質量部以上５０質量部以下、より好ましくは４０質量部以上５０質量部以下含まれ、脂肪族系炭化水素溶剤は、導電性粉末１００質量部に対して、好ましくは２０質量部以上８０質量部以下、より好ましくは２０質量部以上４０質量部以下含まれる。 The organic solvent can contain, for example, a glycol ether solvent as a main solvent and an aliphatic hydrocarbon solvent as a secondary solvent. In this case, the glycol ether-based solvent is preferably contained in an amount of 30 parts by mass or more and 50 parts by mass or less, more preferably 40 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the conductive powder, and is an aliphatic hydrocarbon solvent. Is preferably contained in an amount of 20 parts by mass or more and 80 parts by mass or less, and more preferably 20 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the conductive powder.
（添加剤）
　添加剤としては、ジカルボン酸と、ジカルボン酸以外の分散剤とを含む。以下、各成分について説明する。 (Additive)
The additive includes a dicarboxylic acid and a dispersant other than the dicarboxylic acid. Hereinafter, each component will be described.
＜ジカルボン酸＞
　本発明者は、グラビア印刷用の導電性ペーストにおいて、ジカルボン酸を特定量で含むことにより、導電性粉末とセラミック粉末との分離を抑制し、内部電極層を形成した際に高い被覆率を有することができることを見出した。 <Dicarboxylic acid>
The present inventor suppresses the separation of the conductive powder and the ceramic powder by containing a specific amount of the dicarboxylic acid in the conductive paste for gravure printing, and has a high coverage when the internal electrode layer is formed. I found that I could do it.
　ジカルボン酸は、２つのカルボキシル基（ＣＯＯ－基）を有するカルボン酸系の添加剤である。 Dicarboxylic acid is a carboxylic acid-based additive having two carboxyl groups (COO - groups).
　ジカルボン酸の例としては、テレフタル酸、イソフタル酸、オルソフタル酸、２，６－ナフタレンジカルボン酸等の芳香族ジカルボン酸、コハク酸、グルタル酸、アジピン酸、セバシン酸、ドデカンジカルボン酸、アゼライン酸等の脂肪族ジカルボン酸、ダイマー酸等の炭素数１２～２８の不飽和脂肪酸の二量化によって生成された二塩基酸、水素添加ダイマー酸、１，４－シクロヘキサンジカルボン酸、１，３－シクロヘキサンジカルボン酸、１，２―シクロヘキサンジカルボン酸、４―メチルヘキサヒドロ無水フタル酸、３－メチルヘキサヒドロ無水フタル酸、２－メチルヘキサヒドロ無水フタル酸、ジカルボキシ水素添加ビスフェノールＡ、ジカルボキシ水素添加ビスフェノールＳ、水素添加ナフタレンジカルボン酸、トリシクロデカンジカルボン酸等の脂環族ジカルボン酸などを挙げることができる。 Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid and 2,6-naphthalenedicarboxylic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedicarboxylic acid and azelaic acid. Dibasic acid, hydrogenated dimeric acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, produced by dimerization of unsaturated fatty acids having 12 to 28 carbon atoms such as aliphatic dicarboxylic acid and dimer acid. 1,2-Cyclohexanedicarboxylic acid, 4-methylhexahydrohydride phthalic acid, 3-methylhexahydrohydride phthalic acid, 2-methylhexahydrohydride phthalic acid, dicarboxyhydrogenated bisphenol A, dicarboxyhydrogenated bisphenol S, hydrogen Examples thereof include alicyclic dicarboxylic acids such as added naphthalenedicarboxylic acid and tricyclodecanedicarboxylic acid.
　また、ジカルボン酸の平均分子量は、特に限定されないが、例えば、１０００以下であってもよく、５００以下であってもよく、４００以下であってもよい。ジカルボン酸の平均分子量が上記範囲である場合、高い分離抑制効果を得ることができる。なお、ジカルボン酸の平均分子量の下限は、例えば、１００以上であってもよく、１５０以上であってもよい。 The average molecular weight of the dicarboxylic acid is not particularly limited, but may be, for example, 1000 or less, 500 or less, or 400 or less. When the average molecular weight of the dicarboxylic acid is in the above range, a high separation suppressing effect can be obtained. The lower limit of the average molecular weight of the dicarboxylic acid may be, for example, 100 or more, or 150 or more.
　また、本実施形態に係る導電性ペーストにおいて、ジカルボン酸は、導電性ペースト全体に対して０．１質量％以上３．０質量％未満含まれ、０．３質量％以上１．０質量％以下含まれることが好ましい。ジカルボン酸の含有量が３．０質量%以上である場合、印刷、乾燥工程で、乾燥が不十分となり、内部電極層が柔らかい状態となり、その後の積層工程で積層ズレを生じたり、焼成時に残留したジカルボン酸が気化し、気化したガス成分によって内部応力が発生したり、積層体の構造破壊が生じたりすることがある。 Further, in the conductive paste according to the present embodiment, the dicarboxylic acid is contained in an amount of 0.1% by mass or more and less than 3.0% by mass and 0.3% by mass or more and 1.0% by mass or less based on the entire conductive paste. It is preferably contained. When the content of the dicarboxylic acid is 3.0% by mass or more, the drying is insufficient in the printing and drying steps, the internal electrode layer becomes soft, and the lamination misalignment occurs in the subsequent lamination process or remains during firing. Dicarboxylic acid is vaporized, and the vaporized gas component may generate internal stress or structural destruction of the laminate.
＜分散剤＞
　分散剤としては、公知の分散剤を用いることができる。本実施形態に係る導電性ペーストは、ジカルボン酸と、ジカルボン酸以外の分散剤とを含むことにより、導電性ペーストの分散性を向上させるとともに、導電性粉末とセラミック粉末との分離を抑制して、内部電極層を形成した際の被覆率を向上させることができる。 <Dispersant>
As the dispersant, a known dispersant can be used. The conductive paste according to the present embodiment contains a dicarboxylic acid and a dispersant other than the dicarboxylic acid to improve the dispersibility of the conductive paste and suppress the separation of the conductive powder and the ceramic powder. , It is possible to improve the coverage when the internal electrode layer is formed.
　本実施形態に係る導電性ペーストは、分散剤として、例えば、酸系分散剤及び塩基系分散剤のうちの一方、又は、両方を含んでもよい。また、分散剤として、酸系分散剤を含む場合、酸系分散剤としては、ジカルボン酸以外のカルボキシル基を有する酸系分散剤を含んでもよい。例えば、分散剤として、くし型カルボン酸（くし型構造を有するポリカルボン酸）を用いた場合、くし型カルボン酸を含有することにより、導電性ペーストの分散性は向上するが、導電性粉末とセラミック粉末との分離抑制効果は少ない。なお、分散剤は、１種類を用いてもよく、２種類以上を用いてもよい。本実施形態に係る導電性ペーストは、分散剤を含むことにより、分散性が向上する。 The conductive paste according to the present embodiment may contain, for example, one or both of an acid-based dispersant and a basic-based dispersant as the dispersant. When the dispersant contains an acid-based dispersant, the acid-based dispersant may include an acid-based dispersant having a carboxyl group other than the dicarboxylic acid. For example, when a comb-shaped carboxylic acid (a polycarboxylic acid having a comb-shaped structure) is used as the dispersant, the dispersibility of the conductive paste is improved by containing the comb-shaped carboxylic acid, but the dispersibility is different from that of the conductive powder. The effect of suppressing separation from ceramic powder is small. As the dispersant, one type may be used, or two or more types may be used. The conductive paste according to the present embodiment has improved dispersibility by containing a dispersant.
　分散剤として、例えば、炭化水素基を有する酸系分散剤を含んでもよい。このような酸系分散剤としては、例えば、高級脂肪酸、高分子界面活性剤等の酸系分散剤やリン酸系分散剤などが挙げられる。これらの分散剤は、１種または２種以上組み合わせて用いてもよい。 As the dispersant, for example, an acid-based dispersant having a hydrocarbon group may be contained. Examples of such an acid-based dispersant include acid-based dispersants such as higher fatty acids and polymer surfactants, and phosphoric acid-based dispersants. These dispersants may be used alone or in combination of two or more.
　高級脂肪酸としては、不飽和カルボン酸でも飽和カルボン酸でもよく、特に限定されるものではないが、ステアリン酸、オレイン酸、ミリスチン酸、パルミチン酸、リノール酸、ラウリン酸、リノレン酸など炭素数１１以上のものが挙げられる。中でもオレイン酸、またはステアリン酸が好ましい。 The higher fatty acid may be an unsaturated carboxylic acid or a saturated carboxylic acid, and is not particularly limited, but has 11 or more carbon atoms such as stearic acid, oleic acid, myristic acid, palmitic acid, linoleic acid, lauric acid, and linolenic acid. Can be mentioned. Of these, oleic acid or stearic acid is preferable.
　それ以外の酸系分散剤としては、特に限定されないが、例えば、アルキルモノアミン塩型が好ましい。 The other acid-based dispersant is not particularly limited, but for example, an alkyl monoamine salt type is preferable.
　アルキルモノアミン塩型としては、例えば、グリシンとオレイン酸の化合物であるオレオイルザルコシンや、オレイン酸の代わりにステアリン酸あるいはラウリン酸などの高級脂肪酸を用いたアミド化合物であるステアリン酸アミド、ラウリロイルザルコシンが好ましい。 Examples of the alkyl monoamine salt type include oleoyl zarcosine, which is a compound of glycine and oleic acid, stearic acid amide, which is an amide compound using a higher fatty acid such as stearic acid or lauric acid instead of oleic acid, and lauriloyl. Zarcosin is preferred.
　また、分散剤は、酸系分散剤以外の分散剤を含んでもよい。酸系分散以外の分散剤としては、塩基系分散剤、非イオン系分散剤、両性分散剤などが挙げられる。これらの分散剤は、１種または２種以上組み合わせて用いてもよい。 Further, the dispersant may contain a dispersant other than the acid-based dispersant. Examples of the dispersant other than the acid-based dispersion include a basic-based dispersant, a nonionic dispersant, and an amphoteric dispersant. These dispersants may be used alone or in combination of two or more.
　本実施形態に係る導電性ペーストは、分散剤として、例えば、塩基系分散剤を含んでもよく、分散剤として、塩基系分散剤のみを含んでもよい。塩基系分散剤としては、例えば、ラウリルアミン、ロジンアミン、セチルアミン、ミリスチルアミン、ステアリルアミン、オレイルアミンなどの脂肪族アミンなどが挙げられる。分散剤として、塩基系分散剤を含む場合、導電性粉末とセラミック粉末との分離を抑制して、内部電極層を形成した際の被覆率を向上させることができる。 The conductive paste according to the present embodiment may contain, for example, a base-based dispersant as the dispersant, or may contain only the base-based dispersant as the dispersant. Examples of the basic dispersant include aliphatic amines such as laurylamine, rosinamine, cetylamine, myristylamine, stearylamine, and oleylamine. When a basic dispersant is contained as the dispersant, the separation between the conductive powder and the ceramic powder can be suppressed, and the coverage when the internal electrode layer is formed can be improved.
　導電性ペーストは、上記の分岐炭化水素基を有する酸系分散剤と塩基系分散とを含有する場合、より分散性に優れ、経時的な粘度安定性にも優れる。 When the conductive paste contains the above-mentioned acid-based dispersant having a branched hydrocarbon group and a basic-based dispersion, it is more excellent in dispersibility and viscosity stability over time.
　分散剤は、導電性ペースト全体に対して、好ましくは３質量％以下含有される。分散剤の含有量の上限を含む範囲は、好ましくは、２質量％以下であり、より好ましくは１質量％以下である。分散剤の含有量の下限を含む範囲は、特に限定されないが、例えば、０．０１質量％以上であり、好ましくは０．０５質量％以上である。分散剤の含有量が上記範囲である場合、導電性ペーストの分散性を向上させることにより、乾燥膜の平滑性や乾燥膜密度を向上させつつ、ペースト粘度を適切な範囲に調整することができ、また、印刷後の乾燥性の悪化を防止することができ、さらにシートアタックやグリーンシートの剥離不良を抑制することができる。 The dispersant is preferably contained in an amount of 3% by mass or less based on the entire conductive paste. The range including the upper limit of the content of the dispersant is preferably 2% by mass or less, and more preferably 1% by mass or less. The range including the lower limit of the content of the dispersant is not particularly limited, but is, for example, 0.01% by mass or more, preferably 0.05% by mass or more. When the content of the dispersant is within the above range, the paste viscosity can be adjusted to an appropriate range while improving the smoothness of the dried film and the density of the dried film by improving the dispersibility of the conductive paste. In addition, deterioration of dryness after printing can be prevented, and sheet attack and poor peeling of the green sheet can be suppressed.
　また、分散剤は、導電性粉末１００質量部に対して、好ましくは０．０１質量部以上５質量部以下含有され、より好ましくは０．０５質量部以上３質量部以下含有され、さらに好ましくは０．４質量部以上３質量部以下含有される。分散剤の含有量が上記範囲である場合、導電性粉末やセラミック粉末の分散性や、塗布後の乾燥電極表面の平滑性により優れ、かつ、導電性ペーストの粘度を適切な範囲に調整することができ、また、印刷後の乾燥性の悪化を防止することができ、さらにシートアタックやグリーンシートの剥離不良を抑制することができる。 Further, the dispersant is preferably contained in an amount of 0.01 part by mass or more and 5 parts by mass or less, more preferably 0.05 part by mass or more and 3 parts by mass or less, more preferably, based on 100 parts by mass of the conductive powder. It is contained in an amount of 0.4 parts by mass or more and 3 parts by mass or less. When the content of the dispersant is within the above range, the dispersibility of the conductive powder or ceramic powder and the smoothness of the surface of the dry electrode after coating are excellent, and the viscosity of the conductive paste is adjusted to an appropriate range. In addition, deterioration of dryness after printing can be prevented, and sheet attack and poor peeling of the green sheet can be suppressed.
＜その他の添加剤＞
　本実施形態の導電性ペーストは、必要に応じて、上記の成分以外のその他の添加剤を含んでもよい。その他の添加剤としては、例えば、消泡剤、可塑剤、界面活性剤、増粘剤などの従来公知の添加物を用いることができる。 <Other additives>
The conductive paste of the present embodiment may contain other additives other than the above-mentioned components, if necessary. As other additives, conventionally known additives such as defoamers, plasticizers, surfactants, and thickeners can be used.
（導電性ペースト）
　本実施形態に係る導電性ペーストの製造方法は、特に限定されず、従来公知の方法を用いることができる。導電性ペーストは、例えば、上記の各成分を、３本ロールミル、ボールミル、ミキサーなどで攪拌・混練することにより製造することができる。なお、ジカルボン酸（分離抑制剤）については、他の材料と同様に、ミキサーなどで撹拌・混錬装置する際に秤量して、添加することが好ましいが、撹拌・混錬（分散）終了後の材料に、分離抑制剤として添加しても同様の効果を得ることができる。 (Conductive paste)
The method for producing the conductive paste according to the present embodiment is not particularly limited, and a conventionally known method can be used. The conductive paste can be produced, for example, by stirring and kneading each of the above components with a three-roll mill, a ball mill, a mixer or the like. As with other materials, it is preferable to weigh and add the dicarboxylic acid (separation inhibitor) when stirring and kneading with a mixer or the like, but after stirring and kneading (dispersion) is completed. The same effect can be obtained by adding it as a separation inhibitor to the material of.
　導電性ペーストは、ずり速度１００ｓｅｃ－１の粘度が、好ましくは３Ｐａ・Ｓ以下である。ずり速度１００ｓｅｃ－１の粘度が上記範囲である場合、グラビア印刷用の導電性ペーストとして好適に用いることができる。上記範囲を超えると粘度が高すぎてグラビア印刷用として適さない場合がある。ずり速度１００ｓｅｃ－１の粘度の下限は、特に限定されないが、例えば、０．２Ｐａ・Ｓ以上である。 The conductive paste has a viscosity of 100 sec -1 with a shear rate of preferably 3 Pa · S or less. When the viscosity at a shear rate of 100 sec -1 is in the above range, it can be suitably used as a conductive paste for gravure printing. If it exceeds the above range, the viscosity may be too high to be suitable for gravure printing. The lower limit of the viscosity at a shear rate of 100 sec -1 is not particularly limited, but is, for example, 0.2 Pa · S or more.
　また、導電性ペーストは、ずり速度１００００ｓｅｃ－１の粘度が、好ましくは１Ｐａ・Ｓ以下である。ずり速度１００００ｓｅｃ－１の粘度が上記範囲である場合、グラビア印刷用の導電性ペーストとして好適に用いることができる。上記範囲を超えた場合も、粘度が高すぎてグラビア印刷用として適さない場合がある。ずり速度１００００ｓｅｃ－１の粘度の下限は、特に限定されないが、例えば、０．０５Ｐａ・Ｓ以上である。 Further, the conductive paste has a viscosity of 10000 sec -1 and a viscosity of preferably 1 Pa · S or less. When the viscosity at a shear rate of 10000 sec -1 is in the above range, it can be suitably used as a conductive paste for gravure printing. Even if it exceeds the above range, the viscosity may be too high to be suitable for gravure printing. The lower limit of the viscosity at a shear rate of 10000 sec -1 is not particularly limited, but is, for example, 0.05 Pa · S or more.
　添加剤の含有量は、導電性ペースト全体に対して、３．０質量％未満が望ましい。添加剤の含有量が３．０質量％以上では、印刷、乾燥工程で、乾燥が不十分となり、内部電極層が柔らかい状態となり、その後の積層工程で積層ズレを生じたり、焼成時に残留した添加剤が気化し、気化したガス成分によって内部応力が発生したり、最悪の場合、積層体の構造破壊が生じたりすることがある。 The content of the additive is preferably less than 3.0% by mass with respect to the entire conductive paste. When the content of the additive is 3.0% by mass or more, the drying becomes insufficient in the printing and drying steps, the internal electrode layer becomes soft, and the lamination shift occurs in the subsequent lamination process, or the addition remaining during firing. The agent is vaporized, and the vaporized gas component may generate internal stress, or in the worst case, structural destruction of the laminated body may occur.
　また、導電性ペーストは、作製直後から１日経過後に観察される白浮きの層の厚みが、導電性ペースト全体の厚みに対して、５％未満であることが好ましく、３％以下であってもよく、１％以下であってもよく、０％であってもよい。白浮きの層の厚みが少ないほど、分離抑制効果に優れる。なお、白浮きの層の厚みは、後述する実施例に記載の方法で測定することができる。 Further, in the conductive paste, the thickness of the white floating layer observed one day after the production is preferably less than 5% with respect to the total thickness of the conductive paste, and is preferably 3% or less. It may be 1% or less, or 0%. The smaller the thickness of the white floating layer, the better the separation suppressing effect. The thickness of the white floating layer can be measured by the method described in Examples described later.
　導電性ペーストは、積層セラミックコンデンサなどの電子部品に好適に用いることができる。積層セラミックコンデンサは、誘電体グリーンシートを用いて形成される誘電体層及び導電性ペーストを用いて形成される内部電極層を有する。例えば、導電性ペーストを用いて、後述の実施例に記載される誘電体層（評価用）を形成した場合、内部電極層の被覆率は７５％以上であってもよく、８０％以上であってもよい。 The conductive paste can be suitably used for electronic parts such as multilayer ceramic capacitors. The multilayer ceramic capacitor has a dielectric layer formed by using a dielectric green sheet and an internal electrode layer formed by using a conductive paste. For example, when the dielectric layer (for evaluation) described in Examples described later is formed using a conductive paste, the coverage of the internal electrode layer may be 75% or more, and may be 80% or more. You may.
［電子部品］
　以下、本発明の電子部品等の実施形態について、図面を参照しながら説明する。図面においては、適宜、模式的に表現することや、縮尺を変更して表現することがある。また、部材の位置や方向などを、適宜、図１Ａ及び図１Ｂに示すＸＹＺ直交座標系を参照して説明する。このＸＹＺ直交座標系において、Ｘ方向およびＹ方向は水平方向であり、Ｚ方向は鉛直方向（上下方向）である。 [Electronic components]
Hereinafter, embodiments of the electronic components and the like of the present invention will be described with reference to the drawings. In the drawings, it may be represented schematically or the scale may be changed as appropriate. Further, the positions and directions of the members will be described as appropriate with reference to the XYZ Cartesian coordinate system shown in FIGS. 1A and 1B. In this XYZ Cartesian coordinate system, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction (vertical direction).
　図１Ａ及びＢは、実施形態に係る電子部品の一例である、積層セラミックコンデンサ１を示す図である。積層セラミックコンデンサ１は、誘電体層１２及び内部電極層１１を交互に積層した積層体１０と外部電極２０とを備える。 1A and 1B are diagrams showing a multilayer ceramic capacitor 1 which is an example of an electronic component according to an embodiment. The laminated ceramic capacitor 1 includes a laminated body 10 in which a dielectric layer 12 and an internal electrode layer 11 are alternately laminated, and an external electrode 20.
　以下、上記導電性ペーストを使用した積層セラミックコンデンサの製造方法について説明する。まず、セラミックグリーンシート（誘電体グリーンシート）上に、導電性ペーストを印刷し、乾燥して、乾燥膜を形成する。この乾燥膜を上面に有する複数のセラミックグリーンシートを、圧着により積層させて積層体を得た後、積層体を焼成して一体化することにより、内部電極層１１と誘電体層１２とが交互に積層したセラミック積層体１０を作製する。その後、セラミック積層体１０の両端部に一対の外部電極を形成することにより積層セラミックコンデンサ１が製造される。以下に、より詳細に説明する。 Hereinafter, a method for manufacturing a multilayer ceramic capacitor using the above conductive paste will be described. First, a conductive paste is printed on a ceramic green sheet (dielectric green sheet) and dried to form a dry film. A plurality of ceramic green sheets having the dry film on the upper surface are laminated by pressure bonding to obtain a laminate, and then the laminate is fired to be integrated, whereby the internal electrode layer 11 and the dielectric layer 12 alternate. A ceramic laminate 10 laminated to the above is produced. After that, the multilayer ceramic capacitor 1 is manufactured by forming a pair of external electrodes at both ends of the ceramic laminate 10. It will be described in more detail below.
　まず、未焼成のセラミックシートであるセラミックグリーンシートを用意する。このセラミックグリーンシートとしては、例えば、チタン酸バリウム等の所定のセラミックの原料粉末に、ポリビニルブチラール等の有機バインダーとターピネオール等の溶剤とを加えて得た誘電体層用ペーストを、ＰＥＴフィルム等の支持フィルム上にシート状に塗布し、乾燥させて溶剤を除去したもの等が挙げられる。なお、セラミックグリーンシートからなる誘電体層の厚みは、特に限定されないが、積層セラミックコンデンサの小型化の要請の観点から、０．０５μｍ以上３μｍ以下が好ましい。 First, prepare a ceramic green sheet, which is an unfired ceramic sheet. As this ceramic green sheet, for example, a paste for a dielectric layer obtained by adding an organic binder such as polyvinyl butyral and a solvent such as tarpineol to a predetermined ceramic raw material powder such as barium titanate is used as a PET film or the like. Examples thereof include those coated on a support film in the form of a sheet and dried to remove the solvent. The thickness of the dielectric layer made of the ceramic green sheet is not particularly limited, but is preferably 0.05 μm or more and 3 μm or less from the viewpoint of requesting miniaturization of the multilayer ceramic capacitor.
　次いで、このセラミックグリーンシートの片面に、グラビア印刷法を用いて、上述の導電性ペーストを印刷して塗布し、乾燥して、乾燥膜を形成したものを複数枚、用意する。なお、乾燥膜の厚みは、内部電極層１１の薄層化の要請の観点から、乾燥後１μｍ以下とすることが好ましい。 Next, on one side of this ceramic green sheet, the above-mentioned conductive paste is printed and applied by using a gravure printing method, and dried to form a plurality of dry films. The thickness of the dried film is preferably 1 μm or less after drying from the viewpoint of requesting thinning of the internal electrode layer 11.
　次いで、支持フィルムから、セラミックグリーンシートを剥離するとともに、セラミックグリーンシートとその片面に形成された乾燥膜とが交互に配置されるように積層した後、加熱・加圧処理により積層体を得る。なお、積層体の両面に、導電性ペーストを塗布していない保護用のセラミックグリーンシートを更に配置する構成としても良い。 Next, the ceramic green sheet is peeled off from the support film, and the ceramic green sheet and the dry film formed on one side thereof are laminated so as to be alternately arranged, and then a laminated body is obtained by heat / pressure treatment. It should be noted that a protective ceramic green sheet to which the conductive paste is not applied may be further arranged on both sides of the laminate.
　次いで、積層体を所定サイズに切断してグリーンチップを形成した後、当該グリーンチップに対して脱バインダー処理を施し、還元雰囲気下において焼成することにより、積層セラミック焼成体（セラミック積層体１０）を製造する。なお、脱バインダー処理における雰囲気は、大気またはＮ２ガス雰囲気にすることが好ましい。脱バインダー処理を行う際の温度は、例えば２００℃以上４００℃以下である。また、脱バインダー処理を行う際の、上記温度の保持時間を０．５時間以上２４時間以下とすることが好ましい。また、焼成は、内部電極層に用いる金属の酸化を抑制するために還元雰囲気で行われ、また、積層体の焼成を行う際の温度は、例えば、１０００℃以上１３５０℃以下であり、焼成を行う際の、温度の保持時間は、例えば、０．５時間以上８時間以下である。 Next, after cutting the laminate to a predetermined size to form green chips, the green chips are debindered and fired in a reducing atmosphere to obtain a laminated ceramic fired body (ceramic laminate 10). To manufacture. Incidentally, the atmosphere in the binder removal process is preferably in the air or N 2 gas atmosphere. The temperature at which the debinder treatment is performed is, for example, 200 ° C. or higher and 400 ° C. or lower. Further, it is preferable that the holding time of the above temperature is 0.5 hours or more and 24 hours or less when the debinder treatment is performed. Further, the firing is performed in a reducing atmosphere in order to suppress the oxidation of the metal used for the internal electrode layer, and the temperature at which the laminated body is fired is, for example, 1000 ° C. or higher and 1350 ° C. or lower. The temperature holding time is, for example, 0.5 hours or more and 8 hours or less.
　グリーンチップの焼成を行うことにより、グリーンシート中の有機バインダーが完全に除去されるとともに、セラミックの原料粉末が焼成されて、セラミック製の誘電体層１２が形成される。また内部電極層１１中の有機ビヒクルが除去されるとともに、ニッケル粉末またはニッケルを主成分とする合金粉末が焼結もしくは溶融、一体化されて、内部電極が形成され、誘電体層１２と内部電極層１１とが複数枚、交互に積層された積層セラミック焼成体が形成される。なお、酸素を誘電体層の内部に取り込んで信頼性を高めるとともに、内部電極の再酸化を抑制するとの観点から、焼成後の積層セラミック焼成体に対して、アニール処理を施してもよい。 By firing the green chips, the organic binder in the green sheet is completely removed, and the ceramic raw material powder is fired to form the ceramic dielectric layer 12. Further, the organic vehicle in the internal electrode layer 11 is removed, and nickel powder or an alloy powder containing nickel as a main component is sintered, melted, and integrated to form an internal electrode, and the dielectric layer 12 and the internal electrode are formed. A laminated ceramic fired body in which a plurality of layers 11 are alternately laminated is formed. From the viewpoint of incorporating oxygen into the dielectric layer to improve reliability and suppressing reoxidation of the internal electrodes, the laminated ceramic fired body after firing may be annealed.
　そして、作製した積層セラミック焼成体に対して、一対の外部電極２０を設けることにより、積層セラミックコンデンサ１が製造される。例えば、外部電極２０は、外部電極層２１及びメッキ層２２を備える。外部電極層２１は、内部電極層１１と電気的に接続する。なお、外部電極２０の材料としては、例えば、銅やニッケル、またはこれらの合金が好適に使用できる。なお、電子部品は、積層セラミックコンデンサ以外の電子部品を用いることもできる。 Then, the laminated ceramic capacitor 1 is manufactured by providing a pair of external electrodes 20 with respect to the produced laminated ceramic fired body. For example, the external electrode 20 includes an external electrode layer 21 and a plating layer 22. The external electrode layer 21 is electrically connected to the internal electrode layer 11. As the material of the external electrode 20, for example, copper, nickel, or an alloy thereof can be preferably used. As the electronic component, an electronic component other than the monolithic ceramic capacitor can also be used.
　以下、本発明を実施例と比較例に基づき詳細に説明するが、本発明は実施例によって何ら限定されるものではない。 Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples, but the present invention is not limited to any of the Examples.
［評価方法］
（導電性ペーストの粘度）
　導電性ペーストの製造後の粘度を、レオメーター（株式会社アントンパール・ジャパン製：レオメーターＭＣＲ３０２）を用いて測定した。粘度は、コーン角度１°、直径２５ｍｍのコーンプレートを用いて、ずり速度（せん断速度）１００ｓｅｃ－１、および、１００００ｓｅｃ－１の条件で測定した場合の値を用いた。 [Evaluation method]
(Viscosity of conductive paste)
The viscosity of the conductive paste after production was measured using a rheometer (manufactured by Anton Pearl Japan Co., Ltd .: rheometer MCR302). Viscosity, a cone angle of 1 °, by using a cone plate with a diameter of 25 mm, shear rate (shear rate) 100 sec -1, and, using the value measured under the conditions of 10000 sec -1.
（乾燥性）
　導電性ペーストを誘電体シート上に小型グラビア印刷機（倉敷紡績株式会社製、ＧＰ－１０ＴＹＰＥＩＩ）にて、導電性粉末（Ｎｉ粉末）が０．７ｍｇ／ｃｍ２の割合となる塗布量で印刷したのち、８０℃、４分間のボックス型乾燥器にて乾燥させ、取り出し、内部電極ペーストの乾燥状態を確認した。乾燥性は、乾燥しているものを「〇」、乾燥していない場合を「×」として評価した。 (Dryness)
The conductive paste was printed on a dielectric sheet with a small gravure printing machine (GP-10TYPEII manufactured by Kurashiki Spinning Co., Ltd.) at a coating amount of 0.7 mg / cm 2 of the conductive powder (Ni powder). After that, it was dried in a box-type dryer at 80 ° C. for 4 minutes, taken out, and the dried state of the internal electrode paste was confirmed. The dryness was evaluated as "◯" when it was dry and as "x" when it was not dry.
（白浮き）
　作製直後の導電性ペースト２０ｇをガラス瓶（直径φ３０×高さ６５ｍｍ）中に静置し、１日経過した後、導電性ペーストの外観を目視により観察し、白浮きが観察される割合を測定した。白浮きの割合（％）は、（白浮きの層の厚み／ペースト全体の量の厚み）＊１００で算出される。白浮きの割合（％）は、５％未満を「〇」、５％以上を「×」と評価した。 (White floating)
Immediately after preparation, 20 g of the conductive paste was allowed to stand in a glass bottle (diameter φ30 x height 65 mm), and after 1 day, the appearance of the conductive paste was visually observed, and the rate at which whitening was observed was measured. .. The whitening ratio (%) is calculated by (thickness of the whitening layer / thickness of the total amount of paste) * 100. The percentage of whitening (%) was evaluated as "○" for less than 5% and "x" for 5% or more.
（被覆率）
　小型グラビア印刷機（倉敷紡績株式会社製、ＧＰ－１０ＴＹＰＥＩＩ）を用いて、導電性ペーストをグリーンシート（誘電体シート）上に、導電性粉末（Ｎｉ粉末）が０．７ｍｇ／ｃｍ２の割合となる塗布量で印刷し、積層シートを得た。得られた積層シートを以下の条件で焼成して、評価用の焼成膜（誘電体層と内部電極層との積層体）を得た。 (Coverage)
Small gravure printing machine (Kurabo Co., GP-10TYPEII) using a conductive paste onto the green sheet (dielectric sheet), a conductive powder (Ni powder) and a ratio of 0.7 mg / cm 2 A laminated sheet was obtained by printing with a coating amount of The obtained laminated sheet was fired under the following conditions to obtain a fired film for evaluation (a laminated body of a dielectric layer and an internal electrode layer).
＜焼成条件＞
　Ｎ２／Ｈ２の雰囲気下、昇温速度５℃／分の割合で、１２００℃まで昇温し、１２００℃の焼成温度で、０．５時間焼成した <Baking conditions>
In an atmosphere of N 2 / H 2 , the temperature was raised to 1200 ° C. at a heating rate of 5 ° C./min, and firing was performed at a firing temperature of 1200 ° C. for 0.5 hours.
　得られた焼成膜を、走査型電子顕微鏡（ＳＥＭ）（日本電子株式会社製、ＪＳＭ－６３６０ＬＡ）を用いて、３０００倍にて撮影し、撮影面積中の内部電極が覆っている面積を測定し、被覆率を算出した。被覆率は、（内部電極が覆っている面積）／（撮影面積）×１００にて算出される。なお、被覆率が８０％以上のものを良好（〇）と評価し、８０％未満のものを不良（×）と評価した。 The obtained fired film was photographed at 3000 times using a scanning electron microscope (SEM) (JSM-6360LA, manufactured by JEOL Ltd.), and the area covered by the internal electrodes in the photographed area was measured. , The coverage was calculated. The coverage is calculated by (area covered by the internal electrode) / (photographed area) × 100. Those having a coverage of 80% or more were evaluated as good (◯), and those having a coverage of less than 80% were evaluated as defective (x).
［使用材料］
（導電性粉末）
　導電性粉末としては、Ｎｉ粉末（ＳＥＭ平均粒径０．３μｍ）を使用した。 [Material used]
(Conductive powder)
As the conductive powder, Ni powder (SEM average particle size 0.3 μm) was used.
（セラミック粉末）
　セラミック粉末としては、チタン酸バリウム（ＢａＴｉＯ３；ＳＥＭ平均粒径０．１０μｍ）を使用した。 (Ceramic powder)
As the ceramic powder, barium titanate (BaTIO 3 ; SEM average particle size 0.10 μm) was used.
（バインダー樹脂）
　バインダー樹脂としては、ポリビニルブチラール、エチルセルロース使用した。 (Binder resin)
As the binder resin, polyvinyl butyral and ethyl cellulose were used.
（添加剤）
　分離抑制剤として、ジカルボン酸、くし型カルボン酸（くし型構造を有するポリカルボン酸）、酸化ポリエチレン、及び、変性ウレアを用いた。 (Additive)
As the separation inhibitor, dicarboxylic acid, comb-shaped carboxylic acid (polycarboxylic acid having a comb-shaped structure), polyethylene oxide, and modified urea were used.
　分散剤として、酸系分散剤、及び、塩基系分散剤を用いた。また、酸系分散剤１としてリン酸系分散剤を、酸系分散剤２としてくし型カルボン酸を用い、また、塩基系分散剤１としてオレイルアミンを、塩基系分散剤２としてロジンアミンを用いた。 As the dispersant, an acid-based dispersant and a base-based dispersant were used. Further, a phosphoric acid-based dispersant was used as the acid-based dispersant 1, a comb-type carboxylic acid was used as the acid-based dispersant 2, oleylamine was used as the base-based dispersant 1, and rosinamine was used as the base-based dispersant 2.
（有機溶剤）
　有機溶剤としては、プロピレングリコールモノブチルエーテル（ＰＮＢ）、ミネラルスピリット（ＭＡ）、ターピネオール（ＴＰＯ）、及び、ジヒドロターピネオール（ＤＨＴ）を使用した。 (Organic solvent)
As the organic solvent, propylene glycol monobutyl ether (PNB), mineral spirit (MA), tarpineol (TPO), and dihydroterpineol (DHT) were used.
［実施例１］
　導電性粉末５０質量％、セラミック粉末１２．５質量％、分散剤０．７質量％（酸系分散剤１：０．４質量％、塩基系分散剤１：０．３質量％）、ジカルボン酸０．１質量％、バインダー樹脂３質量％（ポリビニルブチラール樹脂１質量％、エチルセルロース２質量％）、及び、残部として有機溶剤（ＰＮＢ残部、ＭＡ１３．５質量％）を添加して、全体として１００質量％となるよう配合し、これらの材料を混合して導電性ペーストを作製した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 1]
Conductive powder 50% by mass, ceramic powder 12.5% by mass, dispersant 0.7% by mass (acid-based dispersant 1: 0.4% by mass, basic dispersant 1: 0.3% by mass), dicarboxylic acid 0.1% by mass, 3% by mass of binder resin (1% by mass of polyvinyl butyral resin, 2% by mass of ethyl cellulose), and organic solvent (PNB balance, 13.5% by mass of MA) were added as the balance, and 100% by mass as a whole. These materials were mixed to prepare a conductive paste. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例２、４～９、１４］
　ジカルボン酸の含有量を表１に示す割合に変更した以外は、実施例１と同様に導電性ペーストを作製して、評価した。なお、ＰＮＢの添加量を調整することにより、導電性ペーストが１００質量％となるように調整した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Examples 2, 4-9, 14]
A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was changed to the ratio shown in Table 1. By adjusting the amount of PNB added, the conductive paste was adjusted to be 100% by mass. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例３］
　ジカルボン酸の含有量を０．３質量％に変更し、分散剤として、酸系分散剤１のみを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 3]
A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was changed to 0.3% by mass and only the acid-based dispersant 1 was used as the dispersant. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例１０、１１］
　分散剤として、酸系分散剤２のみを用い、分散剤の含有量を表１に示す割合（０．２質量％、０．５質量％）に変更し、有機溶剤としてＴＰＯを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Examples 10 and 11]
Except that only the acid-based dispersant 2 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (0.2% by mass, 0.5% by mass), and TPO was used as the organic solvent. , A conductive paste was prepared in the same manner as in Example 1 and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例１２］
　ジカルボン酸の含有量を０．３質量％に変更し、有機溶剤としてＴＰＯを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 12]
A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was changed to 0.3% by mass and TPO was used as the organic solvent. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例１３］
　ジカルボン酸を分子量（３７０）のものに変更し、その含有量を０．５質量％とした以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 13]
A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the dicarboxylic acid was changed to a molecular weight (370) and the content was 0.5% by mass. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例１５］
　分散剤として、塩基系分散剤１のみを用い、分散剤の含有量を表１に示す割合（０．２質量％に変更し、有機溶剤としてPNBを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 15]
The same as in Example 1 except that only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (changed to 0.2% by mass, and PNB was used as the organic solvent). A conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例１６、１７］
　分散剤として、塩基系分散剤１のみを用い、分散剤の含有量を表１に示す割合（０．２質量％、０．５質量％に変更し、有機溶剤としてTPOを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Examples 16 and 17]
Except that only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratios shown in Table 1 (0.2% by mass and 0.5% by mass, and TPO was used as the organic solvent). A conductive paste was prepared and evaluated in the same manner as in Example 1. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例１８］
　ジカルボン酸を分子量（３７０）のものに変更し、分散剤として、塩基系分散剤１のみを用い、分散剤の含有量を表１に示す割合（０．２質量％に変更し、有機溶剤としてＴＰＯを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 18]
The dicarboxylic acid was changed to one having a molecular weight (370), only the basic dispersant 1 was used as the dispersant, and the content of the dispersant was changed to the ratio (0.2% by mass) shown in Table 1 as an organic solvent. A conductive paste was prepared and evaluated in the same manner as in Example 1 except that TPO was used. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例１９］
　分散剤として、塩基系分散剤２のみを用い、分散剤の含有量を表１に示す割合（０．６質量％）に変更し、有機溶剤としてＴＰＯを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 19]
Same as Example 1 except that only the basic dispersant 2 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (0.6% by mass), and TPO was used as the organic solvent. A conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例２０］
　分散剤として、塩基系分散剤１のみを用い、分散剤の含有量を表１に示す割合（０．２質量％）に変更し、有機溶剤としてＤＨＴを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 20]
Same as Example 1 except that only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratio shown in Table 1 (0.2% by mass), and DHT was used as the organic solvent. A conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［実施例２１］
　ジカルボン酸を分子量（３７０）のものに変更し、分散剤として、塩基系分散剤１のみを用い、分散剤の含有量を表１に示す割合（０．２質量％）に変更し、有機溶剤としてＤＨＴを用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Example 21]
The dicarboxylic acid was changed to one having a molecular weight (370), only the basic dispersant 1 was used as the dispersant, the content of the dispersant was changed to the ratio (0.2% by mass) shown in Table 1, and the organic solvent was used. A conductive paste was prepared and evaluated in the same manner as in Example 1 except that DHT was used as a binder. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［比較例１］
　添加剤としてジカルボン酸を用いなかった以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Comparative Example 1]
A conductive paste was prepared and evaluated in the same manner as in Example 1 except that a dicarboxylic acid was not used as an additive. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
［比較例２］
　ジカルボン酸の含有量を３質量％とした以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。
［比較例３］
　添加剤としてジカルボン酸を用いず、代わりに、くし型カルボン酸を０．５質量％用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。
［比較例４、５］
　添加剤として、ジカルボン酸を用いず、代わりに、チクソ剤である酸化ポリエチレン（比較例４）、変性ウレア（比較例５）を、それぞれ０．５質量％用いた以外は、実施例１と同様に導電性ペーストを作製して、評価した。導電性ペーストの添加剤等の含有量及び評価結果を表１に示す。 [Comparative Example 2]
A conductive paste was prepared and evaluated in the same manner as in Example 1 except that the content of the dicarboxylic acid was 3% by mass. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
[Comparative Example 3]
A conductive paste was prepared and evaluated in the same manner as in Example 1 except that dicarboxylic acid was not used as an additive and 0.5% by mass of comb-type carboxylic acid was used instead. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
[Comparative Examples 4 and 5]
Same as Example 1 except that dicarboxylic acid was not used as an additive and instead, 0.5% by mass of polyethylene oxide (Comparative Example 4) and modified urea (Comparative Example 5), which are tixogens, were used. A conductive paste was prepared and evaluated. Table 1 shows the content of additives and the like of the conductive paste and the evaluation results.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
（評価結果）
　実施例の導電性ペーストは、ジカルボン酸を用いない比較例１の導電性ペーストや、ジカルボン酸の代わりに、くし型カルボン酸を用いた比較例３の導電性ペーストと比較して、白浮きの発生が抑制され、かつ、内部電極層を形成した際に高い被覆率を示す。 (Evaluation results)
The conductive paste of the example is whiter than the conductive paste of Comparative Example 1 that does not use a dicarboxylic acid or the conductive paste of Comparative Example 3 that uses a comb-shaped carboxylic acid instead of the dicarboxylic acid. Occurrence is suppressed and a high coverage is exhibited when the internal electrode layer is formed.
　また、実施例３、１０、１１、１５～２１に示されるように、ジカルボン酸を含み、かつ、分散剤を、導電性ペースト全体に対して、０．６質量％以下、又は、０．５質量％以下含む場合でも、高い分離抑制効果を得ることができる。 Further, as shown in Examples 3, 10, 11, 15 to 21, the dicarboxylic acid is contained and the dispersant is added to the total conductive paste in an amount of 0.6% by mass or less, or 0.5. Even when it contains less than mass%, a high separation suppressing effect can be obtained.
　また、ジカルボン酸を３．０質量％含む比較例２の導電性ペーストでは、乾燥性評価で乾燥しておらず、内部電極層を形成する際にクラックが発生する可能性がある。 Further, the conductive paste of Comparative Example 2 containing 3.0% by mass of dicarboxylic acid was not dried in the drying property evaluation, and cracks may occur when forming the internal electrode layer.
　また、ジカルボン酸の代わりに、チクソ剤として公知である分離抑制剤を用いた比較例４、５の導電性ペーストでは、白浮きの発生は抑制されるものの、内部電極を形成した際の被覆率が低かった。 Further, in the conductive pastes of Comparative Examples 4 and 5 in which a separation inhibitor known as a thixotropic agent was used instead of the dicarboxylic acid, the occurrence of whitening was suppressed, but the coverage when the internal electrode was formed. Was low.
　なお、すべての実施例、及び、比較例の導電性ペーストにおいて、ずり速度１００ｓｅｃ－１での粘度が３Ｐａ・Ｓ以下であり、ずり速度１００００ｓｅｃ－１での粘度が１Ｐａ・Ｓ以下であり、グラビア印刷に適した粘度を有することが確認された。 Note that all examples, and, in the conductive paste of Comparative Example, the viscosity at shear rate 100 sec -1 is not higher than 3 Pa · S, the viscosity at shear rate 10000 sec -1 is not higher than 1 Pa · S, gravure It was confirmed that the viscosity was suitable for printing.
　なお、本発明の技術範囲は、上述の実施形態などで説明した態様に限定されるものではない。上述の実施形態などで説明した要件の１つ以上は、省略されることがある。また、上述の実施形態などで説明した要件は、適宜組み合わせることができる。また、法令で許容される限りにおいて、上述の実施形態などで引用した全ての文献の開示を援用して本文の記載の一部とする。また、法令で許容される限りにおいて、日本特許出願である特願２０１９－１４１５９０の内容を援用して本文の記載の一部とする。 The technical scope of the present invention is not limited to the embodiments described in the above-described embodiments. One or more of the requirements described in the above embodiments and the like may be omitted. In addition, the requirements described in the above-described embodiments can be combined as appropriate. In addition, to the extent permitted by law, the disclosure of all documents cited in the above-mentioned embodiments and the like shall be incorporated as part of the description in the main text. In addition, to the extent permitted by law, the contents of Japanese Patent Application No. 2019-141590 shall be incorporated as part of the description of the main text.
　本発明の導電性ペーストは、グラビア印刷に適した粘度を有し、かつ、導電性粉末とセラミック粉末との分離が非常に抑制され、内部電極を形成した際に、誘電体層上に均一に被覆することができる。よって、本発明の導電性ペーストは、特に携帯電話やデジタル機器などの小型化が進む電子機器のチップ部品である積層セラミックコンデンサの内部電極用の原料として好適に用いることができ、グラビア印刷用の導電性ペーストとして好適に用いることができる。 The conductive paste of the present invention has a viscosity suitable for gravure printing, and the separation of the conductive powder and the ceramic powder is greatly suppressed, and when an internal electrode is formed, it is uniformly formed on the dielectric layer. Can be coated. Therefore, the conductive paste of the present invention can be suitably used as a raw material for an internal electrode of a multilayer ceramic capacitor, which is a chip component of an electronic device such as a mobile phone or a digital device, which is becoming smaller and smaller, and is used for gravure printing. It can be suitably used as a conductive paste.
１　　　　積層セラミックコンデンサ
１０　　　セラミック積層体
１１　　　内部電極層
１２　　　誘電体層
２０　　　外部電極
２１　　　外部電極層
２２　　　メッキ層 1 Multilayer ceramic capacitor 10 Ceramic laminate 11 Internal electrode layer 12 Dielectric layer 20 External electrode 21 External electrode layer 22 Plating layer

Claims (13)

  1. 　導電性粉末、セラミック粉末、添加剤、バインダー樹脂及び有機溶剤を含むグラビア印刷用導電性ペーストであって、
    　前記添加剤は、ジカルボン酸と、ジカルボン酸以外の分散剤とを含み、
    　前記ジカルボン酸を、導電性ペースト全体に対して０．１質量％以上３．０質量％未満含む、グラビア印刷用導電性ペースト。     A conductive paste for gravure printing containing conductive powder, ceramic powder, additives, binder resin and organic solvent.
    The additive contains a dicarboxylic acid and a dispersant other than the dicarboxylic acid.
    A conductive paste for gravure printing containing the dicarboxylic acid in an amount of 0.1% by mass or more and less than 3.0% by mass with respect to the entire conductive paste.
  2. 　前記分散剤は、導電性ペースト全体に対して０．０１質量％以上３．０質量％以下含有される請求項１に記載のグラビア印刷用導電性ペースト。 The conductive paste for gravure printing according to claim 1, wherein the dispersant is contained in an amount of 0.01% by mass or more and 3.0% by mass or less based on the entire conductive paste.
  3. 　前記分散剤は、酸系分散剤および塩基系分散剤のうちの一方、又は、両方を含む請求項１又は請求項２に記載のグラビア印刷用導電性ペースト。 The conductive paste for gravure printing according to claim 1 or 2, wherein the dispersant contains one or both of an acid-based dispersant and a basic-based dispersant.
  4. 　前記導電性粉末は、Ｎｉ、Ｐｄ、Ｐｔ、Ａｕ、Ａｇ、Ｃｕ及びこれらの合金から選ばれる少なくとも１種の金属粉末を含む請求項１～３のいずれか一項に記載のグラビア印刷用導電性ペースト。 The conductivity for gravure printing according to any one of claims 1 to 3, wherein the conductive powder contains at least one metal powder selected from Ni, Pd, Pt, Au, Ag, Cu and an alloy thereof. paste.
  5. 　前記導電性粉末は、平均粒径が０．０５μｍ以上１．０μｍ以下である請求項１～４のいずれか一項に記載のグラビア印刷用導電性ペースト。 The conductive paste for gravure printing according to any one of claims 1 to 4, wherein the conductive powder has an average particle size of 0.05 μm or more and 1.0 μm or less.
  6. 　前記セラミック粉末は、チタン酸バリウムを含む請求項１～５のいずれか一項に記載のグラビア印刷用導電性ペースト。 The ceramic powder is a conductive paste for gravure printing according to any one of claims 1 to 5, which contains barium titanate.
  7. 　前記セラミック粉末は、平均粒径が０．０１μｍ以上０．５μｍ以下である請求項１～６のいずれか一項に記載のグラビア印刷用導電性ペースト。 The conductive paste for gravure printing according to any one of claims 1 to 6, wherein the ceramic powder has an average particle size of 0.01 μm or more and 0.5 μm or less.
  8. 　前記セラミック粉末は、導電性ペースト全体に対して１質量％以上２０質量％以下含まれる請求項１～７のいずれか一項に記載のグラビア印刷用導電性ペースト。 The conductive paste for gravure printing according to any one of claims 1 to 7, wherein the ceramic powder is contained in an amount of 1% by mass or more and 20% by mass or less with respect to the entire conductive paste.
  9. 　前記バインダー樹脂が、セルロース系樹脂を含む請求項１～８のいずれか一項に記載のグラビア印刷用導電性ペースト。 The conductive paste for gravure printing according to any one of claims 1 to 8, wherein the binder resin contains a cellulosic resin.
  10. 　積層セラミック部品の内部電極用である請求項１～９のいずれか一項に記載のグラビア印刷用導電性ペースト。 The conductive paste for gravure printing according to any one of claims 1 to 9, which is used for internal electrodes of laminated ceramic parts.
  11. 　ずり速度１００ｓｅｃ－１での粘度が３Ｐａ・Ｓ以下であり、ずり速度１００００ｓｅｃ－１での粘度が１Ｐａ・Ｓ以下である請求項１～１０のいずれか一項に記載のグラビア印刷用導電性ペースト。 Viscosity at shear rate 100 sec -1 is not higher than 3 Pa · S, shear rate 10000sec viscosity at -1 is less than 1 Pa · S claims 1 to 10, or gravure printing conductive paste according to one of ..
  12. 　請求項１～１１のいずれか一項に記載の導電性ペーストを用いて形成された電子部品。 An electronic component formed by using the conductive paste according to any one of claims 1 to 11.
  13. 　誘電体層と内部電極層とを積層した積層体を少なくとも有し、
    　前記内部電極層は、前記１～１１のいずれか一項に記載のグラビア印刷用導電性ペーストを用いて形成された積層セラミックコンデンサ。     It has at least a laminate in which a dielectric layer and an internal electrode layer are laminated,
    The internal electrode layer is a multilayer ceramic capacitor formed by using the conductive paste for gravure printing according to any one of 1 to 11.
PCT/JP2020/029417 2019-07-31 2020-07-31 Conductive paste for gravure printing, electronic component, and laminate ceramic capacitor WO2021020557A1 (en)

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