WO2022114121A1 - Conductive paste and multilayer ceramic capacitor - Google Patents
Conductive paste and multilayer ceramic capacitor Download PDFInfo
- Publication number
- WO2022114121A1 WO2022114121A1 PCT/JP2021/043372 JP2021043372W WO2022114121A1 WO 2022114121 A1 WO2022114121 A1 WO 2022114121A1 JP 2021043372 W JP2021043372 W JP 2021043372W WO 2022114121 A1 WO2022114121 A1 WO 2022114121A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- conductive paste
- powder
- conductive
- mass
- dispersant
- Prior art date
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- 239000003985 ceramic capacitor Substances 0.000 title claims description 23
- 239000000843 powder Substances 0.000 claims abstract description 139
- 239000002270 dispersing agent Substances 0.000 claims abstract description 82
- 239000000919 ceramic Substances 0.000 claims abstract description 57
- 150000001875 compounds Chemical group 0.000 claims abstract description 33
- 229920005989 resin Polymers 0.000 claims abstract description 31
- 239000011347 resin Substances 0.000 claims abstract description 31
- 239000011230 binding agent Substances 0.000 claims abstract description 29
- 239000003960 organic solvent Substances 0.000 claims abstract description 28
- 239000002253 acid Substances 0.000 claims abstract description 25
- 238000001179 sorption measurement Methods 0.000 claims abstract description 23
- 125000003277 amino group Chemical group 0.000 claims abstract description 15
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 41
- 230000008859 change Effects 0.000 claims description 32
- 238000004519 manufacturing process Methods 0.000 claims description 20
- 229910002113 barium titanate Inorganic materials 0.000 claims description 17
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 claims description 17
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 9
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 claims description 9
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 229910045601 alloy Inorganic materials 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 6
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical group OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- FFQALBCXGPYQGT-UHFFFAOYSA-N 2,4-difluoro-5-(trifluoromethyl)aniline Chemical compound NC1=CC(C(F)(F)F)=C(F)C=C1F FFQALBCXGPYQGT-UHFFFAOYSA-N 0.000 claims description 4
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 claims description 4
- 229910052737 gold Inorganic materials 0.000 claims description 3
- 229910052763 palladium Inorganic materials 0.000 claims description 3
- 229910052697 platinum Inorganic materials 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 230000007774 longterm Effects 0.000 abstract description 2
- 230000001747 exhibiting effect Effects 0.000 abstract 1
- 239000002245 particle Substances 0.000 description 52
- 239000000463 material Substances 0.000 description 23
- 229910000480 nickel oxide Inorganic materials 0.000 description 23
- 239000006185 dispersion Substances 0.000 description 20
- 238000000034 method Methods 0.000 description 19
- 239000011163 secondary particle Substances 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 10
- 239000002904 solvent Substances 0.000 description 9
- 150000001412 amines Chemical class 0.000 description 8
- 239000012298 atmosphere Substances 0.000 description 7
- 238000001035 drying Methods 0.000 description 6
- 238000011156 evaluation Methods 0.000 description 6
- 238000010304 firing Methods 0.000 description 6
- 238000004898 kneading Methods 0.000 description 6
- 238000009736 wetting Methods 0.000 description 6
- 238000004833 X-ray photoelectron spectroscopy Methods 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000002776 aggregation Effects 0.000 description 4
- 238000004220 aggregation Methods 0.000 description 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 238000004438 BET method Methods 0.000 description 3
- 229920002799 BoPET Polymers 0.000 description 3
- 239000001856 Ethyl cellulose Substances 0.000 description 3
- ZZSNKZQZMQGXPY-UHFFFAOYSA-N Ethyl cellulose Chemical compound CCOCC1OC(OC)C(OCC)C(OCC)C1OC1C(O)C(O)C(OC)C(CO)O1 ZZSNKZQZMQGXPY-UHFFFAOYSA-N 0.000 description 3
- 125000000129 anionic group Chemical group 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 235000019325 ethyl cellulose Nutrition 0.000 description 3
- 229920001249 ethyl cellulose Polymers 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 238000007639 printing Methods 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- HBNHCGDYYBMKJN-UHFFFAOYSA-N 2-(4-methylcyclohexyl)propan-2-yl acetate Chemical compound CC1CCC(C(C)(C)OC(C)=O)CC1 HBNHCGDYYBMKJN-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 229910052788 barium Inorganic materials 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 235000010980 cellulose Nutrition 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 239000011362 coarse particle Substances 0.000 description 2
- MWKFXSUHUHTGQN-UHFFFAOYSA-N decan-1-ol Chemical compound CCCCCCCCCCO MWKFXSUHUHTGQN-UHFFFAOYSA-N 0.000 description 2
- DIOQZVSQGTUSAI-UHFFFAOYSA-N decane Chemical compound CCCCCCCCCC DIOQZVSQGTUSAI-UHFFFAOYSA-N 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- UODXCYZDMHPIJE-UHFFFAOYSA-N menthanol Chemical compound CC1CCC(C(C)(C)O)CC1 UODXCYZDMHPIJE-UHFFFAOYSA-N 0.000 description 2
- 239000010955 niobium Substances 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- 239000011164 primary particle Substances 0.000 description 2
- 230000002269 spontaneous effect Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 150000003505 terpenes Chemical class 0.000 description 2
- 235000007586 terpenes Nutrition 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- IIYFAKIEWZDVMP-UHFFFAOYSA-N tridecane Chemical compound CCCCCCCCCCCCC IIYFAKIEWZDVMP-UHFFFAOYSA-N 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- LNAZSHAWQACDHT-XIYTZBAFSA-N (2r,3r,4s,5r,6s)-4,5-dimethoxy-2-(methoxymethyl)-3-[(2s,3r,4s,5r,6r)-3,4,5-trimethoxy-6-(methoxymethyl)oxan-2-yl]oxy-6-[(2r,3r,4s,5r,6r)-4,5,6-trimethoxy-2-(methoxymethyl)oxan-3-yl]oxyoxane Chemical compound CO[C@@H]1[C@@H](OC)[C@H](OC)[C@@H](COC)O[C@H]1O[C@H]1[C@H](OC)[C@@H](OC)[C@H](O[C@H]2[C@@H]([C@@H](OC)[C@H](OC)O[C@@H]2COC)OC)O[C@@H]1COC LNAZSHAWQACDHT-XIYTZBAFSA-N 0.000 description 1
- XFRVVPUIAFSTFO-UHFFFAOYSA-N 1-Tridecanol Chemical compound CCCCCCCCCCCCCO XFRVVPUIAFSTFO-UHFFFAOYSA-N 0.000 description 1
- HYLLZXPMJRMUHH-UHFFFAOYSA-N 1-[2-(2-methoxyethoxy)ethoxy]butane Chemical compound CCCCOCCOCCOC HYLLZXPMJRMUHH-UHFFFAOYSA-N 0.000 description 1
- RERATEUBWLKDFE-UHFFFAOYSA-N 1-methoxy-2-[2-(2-methoxypropoxy)propoxy]propane Chemical compound COCC(C)OCC(C)OCC(C)OC RERATEUBWLKDFE-UHFFFAOYSA-N 0.000 description 1
- VXQBJTKSVGFQOL-UHFFFAOYSA-N 2-(2-butoxyethoxy)ethyl acetate Chemical compound CCCCOCCOCCOC(C)=O VXQBJTKSVGFQOL-UHFFFAOYSA-N 0.000 description 1
- WWJLCYHYLZZXBE-UHFFFAOYSA-N 5-chloro-1,3-dihydroindol-2-one Chemical compound ClC1=CC=C2NC(=O)CC2=C1 WWJLCYHYLZZXBE-UHFFFAOYSA-N 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910001111 Fine metal Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- KGEKLUUHTZCSIP-UHFFFAOYSA-N Isobornyl acetate Natural products C1CC2(C)C(OC(=O)C)CC1C2(C)C KGEKLUUHTZCSIP-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910017493 Nd 2 O 3 Inorganic materials 0.000 description 1
- 239000000020 Nitrocellulose Substances 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
- 239000001940 [(1R,4S,6R)-1,7,7-trimethyl-6-bicyclo[2.2.1]heptanyl] acetate Substances 0.000 description 1
- SMEGJBVQLJJKKX-HOTMZDKISA-N [(2R,3S,4S,5R,6R)-5-acetyloxy-3,4,6-trihydroxyoxan-2-yl]methyl acetate Chemical compound CC(=O)OC[C@@H]1[C@H]([C@@H]([C@H]([C@@H](O1)O)OC(=O)C)O)O SMEGJBVQLJJKKX-HOTMZDKISA-N 0.000 description 1
- 229940081735 acetylcellulose Drugs 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- -1 and among these Chemical compound 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002301 cellulose acetate Polymers 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000007429 general method Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 238000007646 gravure printing Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 125000001165 hydrophobic group Chemical group 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- VJPLIHZPOJDHLB-UHFFFAOYSA-N lead titanium Chemical compound [Ti].[Pb] VJPLIHZPOJDHLB-UHFFFAOYSA-N 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 229920000609 methyl cellulose Polymers 0.000 description 1
- 239000001923 methylcellulose Substances 0.000 description 1
- 235000010981 methylcellulose Nutrition 0.000 description 1
- 230000000051 modifying effect Effects 0.000 description 1
- AIBQNUOBCRIENU-UHFFFAOYSA-N nickel;dihydrate Chemical compound O.O.[Ni] AIBQNUOBCRIENU-UHFFFAOYSA-N 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 229920001220 nitrocellulos Polymers 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 150000003141 primary amines Chemical class 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 1
- 238000010405 reoxidation reaction Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 150000003335 secondary amines Chemical class 0.000 description 1
- VSZWPYCFIRKVQL-UHFFFAOYSA-N selanylidenegallium;selenium Chemical compound [Se].[Se]=[Ga].[Se]=[Ga] VSZWPYCFIRKVQL-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000010944 silver (metal) Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 150000003512 tertiary amines Chemical class 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
- 239000003799 water insoluble solvent Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/46—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on titanium oxides or titanates
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/48—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zirconium or hafnium oxides, zirconates, zircon or hafnates
-
- 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
-
- 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
- H01G4/005—Electrodes
- H01G4/012—Form of non-self-supporting electrodes
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2301/00—Metallic composition of the powder or its coating
- B22F2301/15—Nickel or cobalt
Definitions
- the present invention relates to a conductive paste and a monolithic ceramic capacitor.
- Multilayer ceramic capacitors have 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, the size and capacity can be increased. Can be planned.
- Multilayer ceramic capacitors are manufactured, for example, as follows. First, a conductive paste for an internal electrode is printed (applied) with a predetermined electrode pattern on the surface of a dielectric powder containing barium titanate (BaTIO 3 ) and a dielectric green sheet containing a binder resin. Dry to form a dry film. Next, the dried film and the green sheet are laminated so as to be alternately overlapped to obtain a laminated body. Next, this laminated body is heat-bonded and integrated to form a pressure-bonded body. This crimped body is cut and subjected to a deorganizing binder treatment in an oxidizing atmosphere or an inert atmosphere, and then calcined to obtain a calcined chip. Next, the paste for the external electrode is applied to both ends of the fired chip, and after firing, the surface of the external electrode is nickel-plated or the like to obtain a laminated ceramic capacitor.
- a conductive paste for an internal electrode is printed (applied) with a predetermined electrode pattern on the surface of
- the conductive paste used for forming the internal electrode layer contains, for example, a conductive powder, a ceramic powder, a binder resin and an organic solvent.
- the conductive paste may contain a dispersant in order to improve the dispersibility of the conductive powder or the like.
- the conductive powder contained in the conductive paste also tends to have a smaller particle size (micronization).
- particle size of the conductive powder becomes smaller, the surface area per unit volume increases, so that the properties of the particle surface become dominant.
- the particles constituting the conductive powder are at the submicron level, the particles are likely to adhere to each other by a force such as an intramolecular force or an electrostatic force to form a coarse agglomerate.
- aggregates are present in the conductive powder, they form convex portions on the surface of the internal electrode layer during the manufacture of the laminated ceramic capacitor, and in some cases, break through the ceramic dielectric layer to cause a short circuit between the internal electrode layers. May cause.
- the conductive paste is produced, for example, by containing other materials such as conductive powder in an organic vehicle in which a binder resin is dissolved in an organic solvent, and kneading and dispersing the paste.
- a kneading method in the conventional conductive paste manufacturing process for example, an apparatus such as a high-speed shear mixer or a planetary mixer having two or more axes is used, and an inorganic powder such as a conductive powder and a ceramic powder is contained in an organic vehicle. , Dispersants, organic solvents, etc. are mixed (kneaded).
- the organic vehicle may not be sufficiently mixed, or the surface of the conductive powder or the ceramic powder may not be sufficiently wet. Further, even when the dispersion treatment is performed by a three-roll mill or the like after kneading, problems such as poor dispersion of the conductive powder (metal fine powder) and flakes may occur.
- the conductive powder produced by the wet production method which is one of the general methods for producing fine metal particles, tends to promote the aggregation of the conductive powder at the stage of the drying step of the wet production method, and is conductive.
- the powder is kneaded into the organic vehicle, many aggregates (secondary particles) have already been formed, and the above problems are likely to occur.
- inorganic powder When focusing on the dispersion process of conductive powder and ceramic powder (hereinafter collectively referred to as "inorganic powder") in the process of manufacturing a conductive paste containing a dispersant, the particles constituting the inorganic powder are contained in the paste.
- the dispersion process is divided into the following steps, for example.
- Step of "wetting" the surface of the particles (including secondary particles) constituting the inorganic powder Step of crushing the secondary particles and dispersing the crushed particles in the paste (3) Step to suppress “reaggregation” of particles after crushing
- the above (1) wetting process is a step in which the organic vehicle / organic solvent adheres to the surface of the particles constituting the conductive powder and the ceramic powder, and in the case of the conductive paste containing a dispersant, the secondary particles are in this step.
- the dispersant is adsorbed on the surface of the (aggregate)
- the air existing in the voids inside the secondary particles is replaced by the organic solvent containing the dispersant, and the dispersant is adsorbed on the inner wall of the secondary particles.
- the step of getting wet is, specifically, a step of kneading and stirring using an apparatus such as the above-mentioned mixer, and is also called a pretreatment step.
- the degree of "wetting" of the conductive and ceramic powders affects the processing time in the next dispersion step.
- the above (2) dispersion step is a step that greatly affects the dispersibility of the conductive powder and the ceramic powder (inorganic powder) in the conductive paste.
- a disperser such as a three-roll machine is used.
- the secondary particles (aggregates) of the inorganic powder are crushed to disperse the crushed particles (eg, single primary particles or secondary particles in which a small number of primary particles are aggregated) in an organic vehicle. It is a process.
- the various characteristics of the conductive paste vary widely, and the surface smoothness of the dry film is caused by the coarse particles caused by the secondary particles that are insufficiently crushed. Will worsen.
- the above (3) step of suppressing reaggregation is a step of suppressing "reaggregation" of the particles after crushing by adsorbing the dispersant on the new surface of the particle surface newly appeared by crushing.
- the above (2) dispersion step if an appropriate treatment time is not provided for the dispersion treatment, there may be a portion where the dispersant is not adsorbed on the new surface of the particle surface after crushing, and (3) the step of suppressing reaggregation. In some cases, the particles after crushing may reaggregate and the dispersion stability of the conductive paste may decrease.
- the above-mentioned (2) dispersion step and (3) reaggregation suppression step may proceed at the same time.
- Patent Document 1 As a method for improving the dispersion stability of the conductive paste, for example, in Patent Document 1, as a conductive paste having excellent dispersion stability, specific metal fine particles are added to an organic solvent having a dielectric constant in the range of 4 to 24. Dispersing techniques are disclosed.
- Patent Document 1 can improve the dispersion stability to some extent, the effect of improving the crushability of the formed secondary particles in the above (2) dispersion step is insufficient, and the crushing is insufficient. However, it may contain coarse particles due to insufficient secondary particles, and it is difficult to use it suitably for small products whose thinning progresses.
- the present inventor improves "wetting" on the surface of the particles constituting the inorganic powder, thereby improving the "wetting" of the secondary particles in the above (2) dispersion step.
- the dispersant can be easily crushed and high dispersibility can be obtained, and in the step (3) of suppressing reaggregation, the dispersant is easily adsorbed on the new surface of the crushed particle surface. It has been found that since "reaggregation" of particles can be prevented, the dispersion stability of the conductive paste can be maintained even after long-term storage, and the viscosity stability is also excellent.
- the present invention has high dispersibility and viscosity in a conductive paste using a conductive powder or a ceramic powder that has been miniaturized for miniaturization and thinning of a laminated ceramic electronic component. It is an object of the present invention to provide a conductive paste having excellent stability.
- the amount of H 2 O adsorbed per unit area is 0.30 mg / m 2 or more and 0.70 mg / m 2 or less, the dispersant has a relative permittivity of 10 or more, and (1) has an acid group.
- a conductive paste containing at least one compound selected from the group consisting of a compound and (2) a compound having an amine group.
- the compound having an acid group is a compound containing at least one of a carboxyl group and a phosphoric acid group.
- the binder resin contains at least one selected from the group consisting of cellulosic resins and butyral resins. Further, the content of the binder resin is preferably 0.5% by mass or more and 10% by mass or less with respect to 100% by mass of the conductive paste.
- the conductive powder contains one or more metal powders selected from the group consisting of Ni, Cu, Ag, Pd, Au, Pt powders and alloy powders thereof. Further, the conductive powder is preferably nickel powder.
- NiO is 20 mol% or more and 90 mol% or less.
- the content of the conductive powder is preferably 30% by mass or more and 70% by mass or less with respect to 100% by mass of the conductive paste.
- the ceramic powder is at least one selected from the group consisting of barium titanate and strontium zirconate.
- the conductive paste was allowed to stand at 25 ° C. for 30 days after production, and the rate of change in the viscosity of the conductive paste when measured with a Brookfield viscometer under the conditions of 25 ° C. and 10 rpm was 8 hours after production. It is preferably ⁇ 10% or less with respect to the viscosity of the conductive paste.
- the second aspect of the present invention there is at least a laminate in which a dielectric layer and an internal electrode layer are laminated, and the internal electrode layer is provided by a laminated ceramic capacitor formed by using the above-mentioned conductive paste. Will be done.
- the conductive paste of the present invention has high dispersibility and excellent viscosity stability over time. Therefore, the conductive paste of the present invention can be suitably used, for example, for an electrode whose thinning progresses, and particularly preferably for an electrode of a laminated ceramic electronic component whose miniaturization progresses.
- FIG. 1 is a perspective view and a cross-sectional view showing a multilayer ceramic capacitor according to an embodiment.
- the conductive paste according to the present invention contains a conductive powder, a ceramic powder, a binder resin, an organic solvent and a dispersant.
- a conductive powder a conductive powder, a ceramic powder, a binder resin, an organic solvent and a dispersant.
- Conductive powder The material of the conductive powder is not particularly limited, and a known metal powder or the like can be appropriately selected and used according to the required characteristics. Further, these conductive powders may be used alone or in combination.
- the conductive powder is selected from the group consisting of, for example, nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), and alloys thereof1. More than one kind of metal powder can be used, and among these, Ni, Cu, and one or more kinds of metal powders among these alloys are preferable from the viewpoint of conductivity, corrosion resistance, price, etc. Among them, Ni metal powder (nickel powder) is more preferable. Further, the nickel powder may contain sulfur (S) of about several hundred ppm in order to suppress rapid gas generation due to partial thermal decomposition of the binder resin during the debinder treatment.
- S sulfur
- the method for producing the conductive powder is not particularly limited, and for example, a method of directly precipitating chloride vapor from the gas phase in hydrogen gas, an atomizing method from a molten metal, a spray thermal decomposition method using an aqueous solution, and a metal as a raw material.
- a wet method or the like in which a salt is reduced in an aqueous solution can be applied.
- the average particle size of the conductive powder is not particularly limited and may be selected according to the size of the electronic component to be used.
- the average particle size of the conductive powder is preferably 5 ⁇ m or less, and more preferably 3 ⁇ m or less, for example, for a multilayer ceramic capacitor whose thinning progresses. If the average particle size exceeds 5 ⁇ m, the surface of the internal electrode becomes uneven, which may deteriorate the electrical characteristics of the capacitor, which is not preferable.
- the lower limit of the average particle size of the conductive powder is not particularly limited, but is, for example, 0.05 ⁇ m or more. If the average particle size is smaller than 0.05 ⁇ m, handling becomes extremely difficult and a risk of spontaneous combustion or the like is likely to occur.
- the average particle size of the conductive powder is a particle size calculated by using the specific surface area based on the BET method unless otherwise specified.
- the calculation formula for obtaining the average particle size of nickel powder is as follows (1).
- the wettability with the solvent and the vehicle changes, and in particular, it greatly affects the crushing and dispersibility of the agglomerates of the fine powder, which is becoming finer.
- the strength of hydrophilicity and hydrophobicity of the surface of the conductive powder can be evaluated by the amount of H2O adsorbed.
- the hydrophilicity may become too strong and the viscosity stability may deteriorate. It is considered that this is because the relative permittivity of the conductive powder becomes too high, and the hydrophobic group of the dispersant adsorbed on the conductive powder does not extend, so that it becomes difficult to be compatible with the solvent.
- the proportion of NiO is preferably 20 mol% or more and 90 mol% or less in the surface composition thereof.
- the adsorbed state of the dispersant on the surface of the conductive powder may not be appropriate, or the conductive powder may react with the binder resin. If the dispersant is not sufficiently adsorbed on the surface of the conductive powder, the wettability with an organic solvent or an organic vehicle deteriorates, and the aggregates (secondary particles) of the conductive powder are crushed or the crushed particles (1).
- the suppression of reaggregation of secondary particles, etc.) may be insufficient (that is, the dispersion of the conductive powder may be insufficient), the viscosity stability of the conductive paste may be lowered, or the surface smoothness of the dried film may be poor. be.
- the proportion of NiO in the surface composition of the nickel powder may be 50 mol% or more within the above range. It may be 60 mol% or more, 70 mol% or more, or 80 mol% or more. The larger the proportion of NiO in the above range, the more a conductive paste having high dispersibility can be obtained even if the amount of the dispersant described later is small.
- the proportion of NiO in the surface composition of the nickel powder can be measured by using X-ray photoelectron spectroscopy (XPS). For example, when the Ni2p spectrum on the surface of nickel powder is analyzed using XPS and a Ni peak, a Ni (OH) 2 peak, and a NiO peak are detected, the NiO peak with respect to the total peak area of these three components. From the area ratio, the ratio of NiO (mol%) can be measured.
- XPS X-ray photoelectron spectroscopy
- the content ratio of the conductive powder is preferably 30% by mass or more and 70% by mass or less with respect to the total mass of the conductive paste. If the proportion of the conductive powder is less than 30% by mass, the thickness of the electrode after firing becomes extremely thin and the resistance value rises, or the formation of the electrode film is insufficient and the conductivity is lost, so that the desired capacitance can be obtained. It is not preferable because it may not be available. If it exceeds 70% by mass, it becomes difficult to thin the electrode film, which is not preferable.
- the ratio of the conductive powder to the entire paste is more preferably 40% by mass or more and 60% by mass or less.
- the ceramic powder is not particularly limited, and for example, in the case of a paste for an internal electrode of a laminated ceramic capacitor, a known ceramic powder can be appropriately selected depending on the type of the laminated ceramic capacitor to be applied.
- the ceramic powder preferably contains, for example, at least one oxide powder selected from the group consisting of barium titanate and strontium zirconate, and among these, barium titanate (BaTIO 3 , hereinafter, "BT". It is preferable to contain the powder of).
- barium titanate-based oxide powder for example, a powder containing barium titanate (BT) as a main component and other oxides as a sub-component can be used.
- BT barium titanate
- other oxides as auxiliary components include manganese (Mn), chromium (Cr), silicon (Si), calcium (Ca), barium (Ba), magnesium (Mg), vanadium (V), and tungsten (tungsten). W), tantalum (Ta), niobium (Nb), and one or more oxides selected from rare earth elements can be mentioned.
- barium titanate-based oxide powder As the barium titanate-based oxide powder, the Ba atom and / or Ti atom of barium titanate (BaTIO 3 ) was replaced with another atom, tin (Sn), lead (Pb), zirconium (Zr), or the like. A powder of a perovskite-type oxide strong dielectric such as above may be used.
- the ceramic powder may contain other powders other than the barium titanate-based and strontium zirconate-based oxide powders, for example, zinc oxide (ZnO), which is a ceramic powder forming a green sheet of a laminated ceramic device.
- ZnO zinc oxide
- the average particle size of the ceramic powder may be selected according to the size of the electronic component to be used, etc., but for example, for laminated electronic components whose thinning is progressing, the range of 0.01 ⁇ m or more and 0.5 ⁇ m or less is preferable. .. If it exceeds 0.5 ⁇ m, the unevenness of the film surface after coating and drying becomes severe, and if it is smaller than 0.01 ⁇ m, handling becomes extremely difficult and there is a risk of spontaneous combustion, which is not preferable.
- the content of the ceramic powder is, for example, 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 20% by mass or less, based on the total mass of the conductive paste.
- Binder Resin The binder resin exhibits appropriate viscous property and adhesiveness when printing a conductive paste, improves printability, and also has an effect of improving drying characteristics and the like.
- the binder resin is not particularly limited, and a known material can be used depending on the required properties.
- a cellulosic resin a butyral resin, and an acrylic resin.
- Examples of the cellulosic resin include acetyl cellulose, methyl cellulose, ethyl cellulose, butyl cellulose, nitrocellulose, and partially etherified celluloses.
- Examples of the butyral resin include polyvinyl butyral and the like.
- the butyral resin When used for laminated electronic components, the butyral resin may be contained or the butyral resin may be used alone from the viewpoint of improving the adhesive strength with the green sheet.
- One kind of binder resin may be used, or two or more kinds may be used.
- the content of the binder resin is preferably 0.5% by mass or more and 10% by mass or less, more preferably 1 from the viewpoint of film strength, debinderability, printability, and viscosity with respect to the total mass of the conductive paste. It is by mass% or more and 5% by mass or less.
- the content of the binder resin is smaller than the above range, the strength of the dry film may be lowered, or the adhesion between the electrode pattern portion of the conductive paste and the dielectric sheet may be deteriorated at the time of laminating, and it may be easily peeled off.
- the content of the binder resin exceeds the above range, the content of the binder resin becomes too large, so that the debinder property deteriorates and a part of the binder resin may remain.
- Organic solvent is not particularly limited, the binder resin can be dissolved, the conductive powder can be dispersed, the viscosity of the conductive paste can be adjusted, and appropriate fluidity and printability can be adjusted.
- a known organic solvent that can impart drying characteristics and the like can be used.
- various known organic solvents such as organic solvents having a boiling point of about 150 ° C. to 250 ° C., terpene solvents, aliphatic hydrocarbon solvents, alcohols and the like can be used. ..
- Examples of the terpene-based solvent include tarpineol, dihydroterpineol, and dihydroterpinyl acetate.
- Examples of the aliphatic hydrocarbon solvent include decane and tridecane.
- Examples of alcohols include decanol and tridecanol.
- Examples of the organic solvent having a boiling point of about 150 ° C. to 250 ° C. other than the above include isobornyl acetate, butyl carbitol acetate, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether and the like.
- the content of the organic solvent is preferably 30% by mass or more and 70% by mass or less, preferably 40% by mass or more and 60% by mass, based on the total mass of the conductive paste, from the viewpoints of evaporation amount, viscosity, compatibility with the binder resin, and printability. More preferably, it is by mass or less.
- the order in which the materials are mixed is not particularly limited, but the above binder resin is dissolved in a part of the organic solvent in advance to prepare an organic vehicle, and then the organic vehicle and others. It is preferable to mix the material of the above and the remaining organic solvent (for adjusting the viscosity).
- the blending amount of the binder resin contained in the organic vehicle is not particularly limited, but is 1% by mass with respect to the total mass of the organic vehicle from the viewpoint of making the conductive paste used for electronic parts, which are becoming smaller and smaller, have an appropriate viscosity. It is preferably 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less.
- Dispersant The role of the dispersant is to adsorb to the surface of the inorganic powder (conductive powder and ceramic powder), suppress the aggregation of the inorganic powders, and improve the wettability with the organic vehicle in the conductive paste. It is to disperse to. Dispersants (surfactants) are generally classified into cationic dispersants, anionic dispersants, nonionic dispersants and amphoteric dispersants.
- an anionic dispersant for example, an acid-based dispersant such as a carboxylic acid-based dispersant, a phosphoric acid-based dispersant, or a phosphate-based dispersant
- an acid-based dispersant such as a carboxylic acid-based dispersant, a phosphoric acid-based dispersant, or a phosphate-based dispersant
- the inorganic powder may not be sufficiently dispersed even if an anionic dispersant is used.
- the relative permittivity is 10 or more, and an acid group and / or an amine group is used. It has been found that dispersibility can be improved by using a dispersant containing a compound having. Since such a dispersant has a large adsorption force on the surface of the inorganic powder and the wettability between the inorganic powder and the organic vehicle is improved ((1) "wetting" step), the surface modifying action of the dispersant makes the inorganic powder. It is considered that it contributes to the improvement of dispersibility by promoting the crushing of the above ((2) dispersal step) and suppressing reaggregation ((3) "reaggregation” suppressing step). ..
- the relative permittivity of the dispersant may be 10 or more, 11 or more, or 12 or more.
- the relative permittivity of the dispersant used in the present specification indicates the relative permittivity at 20 ° C. Further, the relative permittivity can be measured by putting an evaluation sample (dispersant used) in an electrode cell for a liquid sample.
- the upper limit of the relative permittivity of the dispersant is not particularly limited, but is, for example, about 15 or less.
- the dispersant contains at least one compound selected from the group consisting of (1) a compound having an acid group and (2) a compound having an amine group.
- the dispersant is a compound corresponding to both (1) a compound having an acid group and (2) a compound having an amine group, that is, (3) a compound having an acid group and an amine group in the same molecule. It may be a mixture containing both (1) a compound having an acid group and (2) a compound having an amine group.
- the compound having an acid group a compound containing at least one of a carboxyl group and a phosphoric acid group is preferable.
- the compound having an amine group includes a primary amine, a secondary amine, and a tertiary amine.
- the dispersant contains a dispersant having an amine value of 100 or more.
- a dispersant having an amine value of 100 or more is used, the dispersibility of the conductive paste can be further improved, and the smoothness of the surface of the dried film after coating can be further improved.
- the acid value of the dispersant having an acid group may be 30 or more and 300 or less, or 30 or more and 200 or less.
- the content of the dispersant is preferably 0.1% by mass or more and 2.0% by mass or less, and more preferably 0.3% by mass or more and 1.0% by mass or less with respect to the total mass of the conductive paste. If the content of the dispersant is less than 0.1% by mass, the content of the dispersant may be too small to obtain the effect of suppressing crushing and reaggregation. On the other hand, if the content of the dispersant is more than 2.0% by mass, the paste characteristics such as printability may be significantly changed, which is not desirable.
- the conductive paste of the present invention contains, if necessary, a defoaming agent, a plasticizer, a thickener, a chelating agent, and a dispersant other than the above-mentioned dispersant, within the range not deviating from the gist of the present invention.
- a defoaming agent such as a plasticizer, a thickener, a chelating agent, and a dispersant other than the above-mentioned dispersant, within the range not deviating from the gist of the present invention.
- One or more known additives such as a dispersant and a thickening agent may be added.
- the method for producing the conductive paste according to the present embodiment is not particularly limited, and the conductive paste can be produced by using a known method.
- the conductive paste is produced by kneading and dispersing each of the above materials with an apparatus such as a mixer, a ball mill, a kneader, and a roll mill to form a slurry.
- the conductive paste according to this embodiment is left to stand at 25 ° C. for 30 days after production, and the rate of change in viscosity ( ⁇ 30 ) when measured with a Brookfield viscometer at 25 ° C. and 10 rpm is the production rate. It is preferably ⁇ 10% or less with respect to the viscosity ( ⁇ 0 ) after 8 hours. When the rate of change in the viscosity of the conductive paste is within the above range, the dispersibility of the conductive paste is excellent.
- the rate of change in viscosity of the conductive paste after standing for 30 days can be calculated by the following formula (2).
- Viscosity change rate (%) ( ⁇ 30 - ⁇ 0 ) / ⁇ 0 ⁇ 100 ... (2) ⁇ 30 : 10 rpm viscosity after 30 days ⁇ 0 : 10 rpm viscosity after 8 hours of manufacture (initial viscosity)
- the glossiness of the dried film of the conductive paste according to the present embodiment is preferably 10 or more, preferably 15 or more, and further preferably 20 or more. The higher the glossiness of the dried film, the less diffused reflection on the entire surface of the dried film, indicating that a smoother surface is obtained.
- the dry film for evaluation is obtained, for example, by printing a conductive paste on a PET film with an area of 5 ⁇ 10 cm and a film thickness of 30 ⁇ m, and then drying the film at 120 ° C. for 40 minutes in the air. Can be done.
- FIGS. 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 ceramic 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 and dried to form a dry film.
- a plurality of ceramic green sheets having the dried film on the upper surface are laminated by pressure bonding to obtain a laminated body, and then the laminated body is fired to be integrated, whereby the internal electrode layer 11 and the dielectric layer 12 alternate.
- the 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 laminated ceramic capacitor.
- a plurality of ceramic green sheets having a dry film formed on one side of the ceramic green sheet were prepared by printing and applying the above-mentioned conductive paste on one side of the ceramic green sheet using a gravure printing method. do.
- the thickness of the dried film formed from the conductive paste 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 and pressure treatment.
- a protective ceramic green sheet to which the conductive paste is not applied may be further arranged on both sides of the laminated body.
- the green chip is subjected to a debinder treatment and fired in a reducing atmosphere to produce a laminated ceramic fired body (ceramic laminate 10). do.
- the atmosphere in the debinder treatment is preferably an atmosphere or an N2 gas atmosphere.
- the temperature at which the debindering 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 during the debindering treatment is 0.5 hours or more and 24 hours or less.
- 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, and the firing is performed.
- the temperature holding time is, for example, 0.5 hours or more and 8 hours or less.
- the organic binder in the ceramic 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 dry film is removed, and nickel powder or an alloy powder containing nickel as a main component is sintered or melted and integrated to form an internal electrode layer 11, 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 taking oxygen into the inside of the dielectric layer to improve reliability and suppressing reoxidation of the internal electrode, 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.
- Rate of change in viscosity of conductive paste over time is determined by first determining the viscosity of the conductive paste after 8 hours of production as the initial viscosity ( ⁇ 0 ). ), Then the viscosity ( ⁇ x ) of the conductive paste after being allowed to stand at room temperature (25 ° C) for 1 day, 10 days and 30 days, respectively, and then the viscosity after being allowed to stand for each number of days. It is expressed as a percentage (%) obtained by dividing the amount of change in the initial viscosity ( ⁇ 0 ). By measuring not only the viscosity change rate after 30 days but also the viscosity change rate after 1 day and 10 days, the tendency of the viscosity change was confirmed.
- Viscosity change rate (%) ( ⁇ x ⁇ 0 ) / ⁇ 0 ⁇ 100 ⁇ ⁇ ⁇ (2) ⁇ x : 10 rpm viscosity after X days ⁇ 0 : 10 rpm viscosity after 8 hours of manufacture (initial viscosity)
- the conductive paste is printed on a PET film with an area of 5 ⁇ 10 cm and a film thickness of 30 ⁇ m, and then dried in air at 120 ° C. for 40 minutes to form a dried film (dried conductive paste). Obtained.
- the glossiness of the obtained dried film at an incident angle of 60 ° was measured with a glossiness meter (Gloss Checker manufactured by HORIBA, Ltd .; IG-320). The higher the glossiness, the less diffused reflection is, indicating that a smoother surface is obtained.
- Ratio of NiO on the surface of nickel powder The surface of the nickel powder used as the conductive powder was measured by X-ray photoelectron spectroscopy (XPS), and nickel hydroxide (Ni (OH) 2 ) and nickel oxide (NiO) were measured. The peaks of nickel and metallic nickel attributed to NiO were detected, and the ratio of NiO (mol%) was calculated from the respective abundance ratios.
- Example 1 As a conductive powder, nickel powder ( H2O adsorption amount 0.31 mg / m 2 , NiO surface abundance ratio 34 mol%, particle size 0.4 ⁇ m) was 47% by mass, and as a ceramic powder, barium titanate (particle size 0). .05 ⁇ m) was added in an amount of 4.7% by mass, an organic vehicle was added in an amount of 26.67% by mass, a dispersant was added in an amount of 0.4% by mass, and the balance of an organic solvent was added in an amount of 21.23% by mass.
- the organic vehicle used was prepared by blending 13% by mass of ethyl cellulose as a binder resin and 87% by mass of tarpineol as an organic solvent and heating and mixing at 60 ° C.
- an amine-based dispersant having a relative permittivity of 12.5, an acid value of 58, and an amine value of 110 (a mixture of a compound having an acid group and a compound having an amine group) was used.
- Tarpineol was used as the organic solvent.
- Table 1 shows the types and contents of each material used, and Table 2 shows the measurement results and calculation results.
- Example 2 As the conductive powder, nickel powder having an H2O adsorption amount of 0.53 mg / m 2 , a NiO surface presence ratio of 26 mol%, and a particle size of 0.2 ⁇ m was used, and the dispersant content was 0.6% by mass.
- a conductive paste was prepared in the same manner as in Example 1 except that the organic solvent was dihydroterpinyl acetate and the residual content was 21.03% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 3 Nickel powder having an H2O adsorption amount of 0.42 mg / m 2 , a surface presence ratio of NiO of 45 mol%, and a particle size of 0.08 ⁇ m was used as the conductive powder, and BT having a particle size of 0.02 ⁇ m was used as the ceramic powder.
- a conductive paste was prepared in the same manner as in Example 2 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 4 A conductive paste was prepared in the same manner as in Example 2 except that an acid-based dispersant having a carboxyl group having a relative permittivity of 11.4 and an acid value of 129 was used as the dispersant. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 5 Nickel powder having an H2O adsorption amount of 0.42 mg / m 2 , a surface presence ratio of NiO of 45 mol%, and a particle size of 0.08 ⁇ m was used as the conductive powder, and BT having a particle size of 0.02 ⁇ m was used as the ceramic powder.
- a conductive paste was prepared in the same manner as in Example 4 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 6 A conductive paste was prepared in the same manner as in Example 2 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2. [Example 7] As the conductive powder, the conductive paste was used in the same manner as in Example 6 except that nickel powder having an H2O adsorption amount of 0.34 mg / m 2 , a surface presence ratio of NiO of 79 mol%, and a particle size of 0.2 ⁇ m was used. Was produced.
- Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 8 As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.38 mg / m 2 , a surface abundance ratio of NiO of 89 mol%, and a particle size of 0.2 ⁇ m was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 1 Same as Example 2 except that a dispersant having an amine group having a specific dielectric constant of 3.0, an acid value of 53, and an amine value of 48 (a mixture of a compound having an acid group and a compound having an amine group) was used as the dispersant.
- a conductive paste To prepare a conductive paste. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 2 Same as Example 2 except that a dispersant having an amine group having a specific dielectric constant of 8.5, an acid value of 60, and an amine value of 60 (a mixture of a compound having an acid group and a compound having an amine group) was used as the dispersant.
- a conductive paste To prepare a conductive paste. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 3 As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.29 mg / m 2 , a surface abundance ratio of NiO of 49 mol%, and a particle size of 0.2 ⁇ m was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 4 As the conductive powder, the conductive paste was used in the same manner as in Example 6 except that nickel powder having an H2O adsorption amount of 0.29 mg / m 2 , a surface abundance ratio of NiO of 49 mol%, and a particle size of 0.2 ⁇ m was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- Example 5 As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.71 mg / m 2 , a NiO surface presence ratio of 42 mol%, and a particle size of 0.2 ⁇ m was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
- the conductive paste of the example containing the dispersant having a relative permittivity of 10 or more has a higher glossiness on the surface of the dried film and is excellent in smoothness as compared with the conductive paste of the comparative example having a relative permittivity of less than 10. You can see that there is. In addition, since the rate of change in viscosity is small, it can be seen that the improvement in dispersibility due to the adsorption of the dispersant is maintained for a long period of time.
- Examples 4 and 5 using a dispersant having no amine value (amine group) and only an acid value (acid group) have a slightly lower glossiness than the other examples, but are comparative examples. By comparison, it shows a sufficiently high glossiness and a small rate of change in viscosity. Therefore, from the viewpoint of improving the smoothness of the entire surface of the dried film, it is preferable to use a dispersant having an amine value of 100 or more.
- the conductive pastes of Comparative Examples 1 and 2 containing a dispersant having a relative permittivity of less than 10 have a very low glossiness on the surface of the dried film and are inferior in smoothness. This is because the dispersant does not satisfy the predetermined characteristics, so that the wettability to the particle surface is poor, and the dispersant is not sufficiently adsorbed to the particle surface, so that the crushing and reaggregation of the particles cannot be sufficiently suppressed. It is considered that the dispersibility of the conductive paste is poor, the material is biased, and the smoothness of the dry film surface is inferior. Further, it is considered that the dispersant has poor adsorptivity, so that the dispersion stability is poor and the aggregation of each material increases with time, and therefore the viscosity change rate increases with time.
- Comparative Examples 3 to 5 in which the amount of H 2 O adsorbed per unit area is outside the scope of the invention although the smoothness is low to some extent, the surface condition of the conductive powder is not appropriate in any of them, so that when they are made into a paste, they are made into a paste. It is considered that the dispersion stability is poor, the aggregation of the conductive powders increases with time, and the viscosity change rate also increases with time.
- Multilayer ceramic capacitor 10 Ceramic laminate 11 Internal electrode layer 12 Dielectric layer 20 External electrode 21 External electrode layer 22 Plating layer
Abstract
The present invention provides a conductive paste which has high dispersibility, while exhibiting excellent long-term viscosity stability. A conductive paste which contains a conductive powder, a ceramic powder, a binder resin, an organic solvent and a dispersant, wherein: the conductive powder has an H2O adsorption per unit area of from 0.30 mg/m2 to 0.70 mg/m2 at a relative pressure P/P0 of 0.5; and the dispersant has a relative dielectric constant of 10 or more, while containing at least one compound that is selected from the group consisting of (1) compounds having an acid group and (2) compounds having an amine group.
Description
本発明は、導電性ペースト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 and a monolithic 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。
With the miniaturization and higher performance of electronic devices such as mobile phones and digital devices, it is desired to reduce the size and capacity of electronic components including monolithic ceramic capacitors. Multilayer ceramic capacitors have 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, the size and capacity can be increased. 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、内部電極用の導電性ペーストを所定の電極パターンで印刷（塗布）し、乾燥して、乾燥膜を形成する。次に、乾燥膜とグリーンシートとが交互に重なるように積層して積層体を得る。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 conductive paste for an internal electrode is printed (applied) with a predetermined electrode pattern on the surface of a dielectric powder containing barium titanate (BaTIO 3 ) and a dielectric green sheet containing a binder resin. Dry to form a dry film. Next, the dried film and the green sheet are laminated so as to be alternately overlapped to obtain a laminated body. Next, this laminated body is heat-bonded and integrated to form a pressure-bonded body. This crimped body is cut and subjected to a deorganizing binder treatment in an oxidizing atmosphere or an inert atmosphere, and then calcined to obtain a calcined chip. Next, the paste for the external electrode is applied to both ends of the fired chip, and after firing, the surface of the external electrode is nickel-plated or the like to obtain a laminated ceramic capacitor.
内部電極層の形成に用いられる導電性ペーストは、例えば、導電性粉末、セラミック粉末、バインダー樹脂及び有機溶剤を含む。また、導電性ペーストは、導電性粉末などの分散性を向上させるために分散剤を含むことがある。
The conductive paste used for forming the internal electrode layer contains, for example, a conductive powder, a ceramic powder, a binder resin and an organic solvent. In addition, the conductive paste may contain a dispersant in order to improve the dispersibility of the conductive powder or the like.
近年の内部電極層の薄膜化に伴い、導電性ペーストに含まれる導電性粉末も小粒径化（微粉化）する傾向がある。導電性粉末の粒径が小さくなると、単位体積当たりの表面積が増大するので粒子表面の性質が支配的となる。特に導電性粉末を構成する粒子がサブミクロンレベルになると、粒子同士が分子間力や静電気力などの力により付着して粗大な凝集体を形成しやすくなる。このような凝集体が導電性粉末内に存在すると、積層セラミックコンデンサ製造時においてそれらが内部電極層表面に凸状部を形成し、場合によってはセラミック誘電体層を突き破って内部電極層間でショートを引き起こすおそれがある。
With the recent thinning of the internal electrode layer, the conductive powder contained in the conductive paste also tends to have a smaller particle size (micronization). As the particle size of the conductive powder becomes smaller, the surface area per unit volume increases, so that the properties of the particle surface become dominant. In particular, when the particles constituting the conductive powder are at the submicron level, the particles are likely to adhere to each other by a force such as an intramolecular force or an electrostatic force to form a coarse agglomerate. When such aggregates are present in the conductive powder, they form convex portions on the surface of the internal electrode layer during the manufacture of the laminated ceramic capacitor, and in some cases, break through the ceramic dielectric layer to cause a short circuit between the internal electrode layers. May cause.
導電性ペーストは、例えば、有機溶剤にバインダー樹脂を溶解させた有機ビヒクル中に、導電性粉末などの他の材料を含有させ、混練および分散することで作製される。従来の導電性ペーストの製造工程における混練手法としては、例えば、高速せん断ミキサや２軸以上のプラネタリーミキサなどの装置を使用し、有機ビヒクル中に、導電性粉末およびセラミック粉末などの無機粉末や、分散剤、有機溶剤などを混合（混練）する方法が用いられる。
The conductive paste is produced, for example, by containing other materials such as conductive powder in an organic vehicle in which a binder resin is dissolved in an organic solvent, and kneading and dispersing the paste. As a kneading method in the conventional conductive paste manufacturing process, for example, an apparatus such as a high-speed shear mixer or a planetary mixer having two or more axes is used, and an inorganic powder such as a conductive powder and a ceramic powder is contained in an organic vehicle. , Dispersants, organic solvents, etc. are mixed (kneaded).
しかしながら、従来の混練手法では、導電性粉末の小粒径化に伴い、有機ビヒクルが十分に混ざらない、導電性粉末やセラミック粉末の表面が十分に濡れない等の状態となることがある。さらに、混錬後、３本ロールミルなどで分散処理を行う場合も、導電性粉末（金属微粉）の分散不良やフレーク等の問題が生じることがある。
However, in the conventional kneading method, as the particle size of the conductive powder is reduced, the organic vehicle may not be sufficiently mixed, or the surface of the conductive powder or the ceramic powder may not be sufficiently wet. Further, even when the dispersion treatment is performed by a three-roll mill or the like after kneading, problems such as poor dispersion of the conductive powder (metal fine powder) and flakes may occur.
また、一般的な金属微粉の製造方法の一つである湿式製造法より生成された導電性粉末は、該湿式製造法が有する乾燥工程の段階において導電性粉末の凝集が促進されやすく、導電性粉末を有機ビヒクルに混錬する時点で既に多くの凝集体（２次粒子）を形成しており、上記問題が生じやすい。
Further, the conductive powder produced by the wet production method, which is one of the general methods for producing fine metal particles, tends to promote the aggregation of the conductive powder at the stage of the drying step of the wet production method, and is conductive. By the time the powder is kneaded into the organic vehicle, many aggregates (secondary particles) have already been formed, and the above problems are likely to occur.
分散剤を含む導電性ペーストの製造工程において、導電性粉末およびセラミック粉末（以下、両者をまとめて「無機粉末」ともいう）の分散過程に着目した場合、無機粉末を構成する粒子がペースト中に分散する過程は、例えば、以下の工程に分けられる。
When focusing on the dispersion process of conductive powder and ceramic powder (hereinafter collectively referred to as "inorganic powder") in the process of manufacturing a conductive paste containing a dispersant, the particles constituting the inorganic powder are contained in the paste. The dispersion process is divided into the following steps, for example.
（１）無機粉末を構成する粒子（２次粒子を含む）の表面が「濡れ」る工程
（２）２次粒子が解砕され、解砕後の粒子がペースト中に分散する工程
（３）解砕後の粒子の「再凝集」を抑制する工程 (1) Step of "wetting" the surface of the particles (including secondary particles) constituting the inorganic powder (2) Step of crushing the secondary particles and dispersing the crushed particles in the paste (3) Step to suppress "reaggregation" of particles after crushing
（２）２次粒子が解砕され、解砕後の粒子がペースト中に分散する工程
（３）解砕後の粒子の「再凝集」を抑制する工程 (1) Step of "wetting" the surface of the particles (including secondary particles) constituting the inorganic powder (2) Step of crushing the secondary particles and dispersing the crushed particles in the paste (3) Step to suppress "reaggregation" of particles after crushing
上記（１）濡れる過程は、導電性粉末およびセラミック粉末を構成する粒子の表面に有機ビヒクル／有機溶剤が付着する工程であり、分散剤を含む導電性ペーストでは、この工程にて、２次粒子（凝集体）表面に分散剤が吸着すると同時に、２次粒子内部の空隙に存在する空気が分散剤を含有する有機溶剤により置換され、その２次粒子の内壁に分散剤が吸着する。
The above (1) wetting process is a step in which the organic vehicle / organic solvent adheres to the surface of the particles constituting the conductive powder and the ceramic powder, and in the case of the conductive paste containing a dispersant, the secondary particles are in this step. At the same time that the dispersant is adsorbed on the surface of the (aggregate), the air existing in the voids inside the secondary particles is replaced by the organic solvent containing the dispersant, and the dispersant is adsorbed on the inner wall of the secondary particles.
また、（１）濡れる工程は、具体的には、例えば、上述のミキサなどの装置を使用した混練攪拌を行う工程であり、前処理工程とも呼ばれる。導電性粉末およびセラミック粉末の「濡れ」の程度は、次の分散工程での処理時間に影響する。
Further, (1) the step of getting wet is, specifically, a step of kneading and stirring using an apparatus such as the above-mentioned mixer, and is also called a pretreatment step. The degree of "wetting" of the conductive and ceramic powders affects the processing time in the next dispersion step.
上記（２）分散工程は、導電性ペースト中の導電性粉末およびセラミック粉末（無機粉末）の分散性に大きく影響する工程であり、具体的には、例えば、３本ロールなどの分散機により、無機粉末の２次粒子（凝集体）を解砕して、解砕された粒子（例：単独の１次粒子または少数の１次粒子が凝集した２次粒子）を、有機ビヒクル中に分散させる工程である。（２）分散工程後の粒子の分散性が悪い場合、導電性ペーストの各種特性のばらつきが大きくなったり、解砕が不十分な２次粒子に起因する粗大粒子により乾燥膜の表面の平滑性の悪化が生じたりする。
The above (2) dispersion step is a step that greatly affects the dispersibility of the conductive powder and the ceramic powder (inorganic powder) in the conductive paste. Specifically, for example, a disperser such as a three-roll machine is used. The secondary particles (aggregates) of the inorganic powder are crushed to disperse the crushed particles (eg, single primary particles or secondary particles in which a small number of primary particles are aggregated) in an organic vehicle. It is a process. (2) When the dispersibility of the particles after the dispersion step is poor, the various characteristics of the conductive paste vary widely, and the surface smoothness of the dry film is caused by the coarse particles caused by the secondary particles that are insufficiently crushed. Will worsen.
上記（３）再凝集を抑制する工程は、解砕により新たに表れた粒子表面の新生面に分散剤が吸着することにより、解砕後の粒子の「再凝集」を抑制する工程である。上記（２）分散工程において、分散処理に適切な処理時間を設けないと、解砕後の粒子表面の新生面に分散剤が吸着されない部分が存在する場合があり、（３）再凝集の抑制工程において、解砕後の粒子が再凝集してしまい、導電性ペーストの分散安定性が低下する場合がある。なお、上記（２）分散工程と（３）再凝集の抑制工程は、同時に進行してもよい。
The above (3) step of suppressing reaggregation is a step of suppressing "reaggregation" of the particles after crushing by adsorbing the dispersant on the new surface of the particle surface newly appeared by crushing. In the above (2) dispersion step, if an appropriate treatment time is not provided for the dispersion treatment, there may be a portion where the dispersant is not adsorbed on the new surface of the particle surface after crushing, and (3) the step of suppressing reaggregation. In some cases, the particles after crushing may reaggregate and the dispersion stability of the conductive paste may decrease. The above-mentioned (2) dispersion step and (3) reaggregation suppression step may proceed at the same time.
導電性ペーストの分散安定性を向上させる手法として、例えば、特許文献１では、分散安定性に優れる導電性ペーストとして、誘電率が４～２４の範囲内にある有機溶媒に、特定の金属微粒子を分散させる技術が開示されている。
As a method for improving the dispersion stability of the conductive paste, for example, in Patent Document 1, as a conductive paste having excellent dispersion stability, specific metal fine particles are added to an organic solvent having a dielectric constant in the range of 4 to 24. Dispersing techniques are disclosed.
しかしながら、上記特許文献１に記載の技術では、分散安定性はある程度向上できるものの、上記（２）分散工程において、形成された２次粒子の解砕性を向上させる効果は不十分で、解砕が不十分な２次粒子に起因する粗粒を内包してしまう場合があり、薄膜化の進む小型製品用に好適に用いることが困難である。
However, although the technique described in Patent Document 1 can improve the dispersion stability to some extent, the effect of improving the crushability of the formed secondary particles in the above (2) dispersion step is insufficient, and the crushing is insufficient. However, it may contain coarse particles due to insufficient secondary particles, and it is difficult to use it suitably for small products whose thinning progresses.
上記問題点に鑑み、本発明者が鋭意研究を重ねた結果、本発明者は、無機粉末を構成する粒子表面に対する「濡れ」を改善することにより、上記（２）分散工程において、２次粒子の解砕を容易に行うことができ、かつ、高い分散性が得られること、および、上記（３）再凝集を抑制する工程において、解砕した粒子表面の新生面に分散剤が吸着されやすくなり、粒子の「再凝集」を防止できるため、長期保存しても導電性ペーストの分散安定性を維持することができ、粘度安定性にも優れること、を見出した。
In view of the above problems, as a result of intensive research by the present inventor, the present inventor improves "wetting" on the surface of the particles constituting the inorganic powder, thereby improving the "wetting" of the secondary particles in the above (2) dispersion step. The dispersant can be easily crushed and high dispersibility can be obtained, and in the step (3) of suppressing reaggregation, the dispersant is easily adsorbed on the new surface of the crushed particle surface. It has been found that since "reaggregation" of particles can be prevented, the dispersion stability of the conductive paste can be maintained even after long-term storage, and the viscosity stability is also excellent.
本発明は、このような状況に鑑み、積層セラミック電子部品の小型化、薄型化のために微細化した導電性粉末やセラミック粉末を用いた導電性ペーストにおいて、高い分散性を有し、かつ粘度安定性に優れた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, the present invention has high dispersibility and viscosity in a conductive paste using a conductive powder or a ceramic powder that has been miniaturized for miniaturization and thinning of a laminated ceramic electronic component. It is an object of the present invention to provide a conductive paste having excellent stability.
本発明の第１の態様によれば、導電性粉末、セラミック粉末、バインダー樹脂、有機溶剤および分散剤を含有する導電性ペーストにおいて、導電性粉末は、相対圧Ｐ／Ｐ０＝０．５における単位面積当たりのＨ２Ｏ吸着量が０．３０ｍｇ／ｍ２以上０．７０ｍｇ／ｍ２以下であり、分散剤が、１０以上の比誘電率を有し、かつ、（１）酸基を有する化合物、及び、（２）アミン基を有する化合物からなる群より選ばれる少なくとも１種類の化合物を含有する、導電性ペーストが提供される。
According to the first aspect of the present invention, in a conductive paste containing a conductive powder, a ceramic powder, a binder resin, an organic solvent and a dispersant, the conductive powder has a relative pressure of P / P 0 = 0.5. The amount of H 2 O adsorbed per unit area is 0.30 mg / m 2 or more and 0.70 mg / m 2 or less, the dispersant has a relative permittivity of 10 or more, and (1) has an acid group. Provided is a conductive paste containing at least one compound selected from the group consisting of a compound and (2) a compound having an amine group.
また、（１）酸基を有する化合物が、カルボキシル基およびリン酸基の少なくとも一方を含む化合物であることが好ましい。また、バインダー樹脂が、セルロース系樹脂及びブチラール系樹脂からなる群より選ばれる１種以上を含有することが好ましい。また、バインダー樹脂の含有量が、導電性ペースト１００質量％に対して０．５質量％以上１０質量％以下であることが好ましい。また、導電性粉末が、Ｎｉ、Ｃｕ、Ａｇ、Ｐｄ、Ａｕ、Ｐｔ粉末、及びこれらの合金粉末からなる群より選ばれる１種以上の金属粉末を含有することが好ましい。また、導電性粉末が、ニッケル粉末であることが好ましい。また、ニッケル粉末の表面組成において、ＮｉＯが２０モル％以上９０モル％以下であることが好ましい。また、導電性粉末の含有量が、導電性ペースト１００質量％に対して３０質量％以上７０質量％以下であることが好ましい。また、セラミック粉末が、チタン酸バリウム系およびジルコン酸ストロンチウム系からなる群より選ばれる少なくとも１種であることが好ましい。また、導電性ペーストは、製造後２５℃で３０日間静置し、ブルックフィールド粘度計にて２５℃、１０ｒｐｍの条件にて測定した際の導電性ペーストの粘度の変化率が、製造８時間後の導電性ペーストの粘度に対して、±１０％以下であることが好ましい。
Further, it is preferable that (1) the compound having an acid group is a compound containing at least one of a carboxyl group and a phosphoric acid group. Further, it is preferable that the binder resin contains at least one selected from the group consisting of cellulosic resins and butyral resins. Further, the content of the binder resin is preferably 0.5% by mass or more and 10% by mass or less with respect to 100% by mass of the conductive paste. Further, it is preferable that the conductive powder contains one or more metal powders selected from the group consisting of Ni, Cu, Ag, Pd, Au, Pt powders and alloy powders thereof. Further, the conductive powder is preferably nickel powder. Further, in the surface composition of the nickel powder, it is preferable that NiO is 20 mol% or more and 90 mol% or less. Further, the content of the conductive powder is preferably 30% by mass or more and 70% by mass or less with respect to 100% by mass of the conductive paste. Further, it is preferable that the ceramic powder is at least one selected from the group consisting of barium titanate and strontium zirconate. Further, the conductive paste was allowed to stand at 25 ° C. for 30 days after production, and the rate of change in the viscosity of the conductive paste when measured with a Brookfield viscometer under the conditions of 25 ° C. and 10 rpm was 8 hours after production. It is preferably ± 10% or less with respect to the viscosity of the conductive paste.
本発明の第２の態様によれば、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。
According to the second aspect of the present invention, there is at least a laminate in which a dielectric layer and an internal electrode layer are laminated, and the internal electrode layer is provided by a laminated ceramic capacitor formed by using the above-mentioned conductive paste. Will be done.
本発明の導電性ペーストは、高い分散性を有し、かつ経時粘度安定性に優れる。よって、本発明の導電性ペーストは、例えば、薄膜化の進む電極等に好適に用いることができ、特に小型化の進む積層セラミック電子部品の電極用に好適に用いることができる。
The conductive paste of the present invention has high dispersibility and excellent viscosity stability over time. Therefore, the conductive paste of the present invention can be suitably used, for example, for an electrode whose thinning progresses, and particularly preferably for an electrode of a laminated ceramic electronic component whose miniaturization progresses.
１．導電性ペースト
本発明に係る導電性ペーストは、導電性粉末、セラミック粉末、バインダー樹脂、有機溶剤および分散剤を含有する。以下、本発明に係る導電性ペーストに含まれる各成分、及び、導電性ペーストの特性などについて、詳細に説明する。 1. 1. Conductive paste The conductive paste according to the present invention contains a conductive powder, a ceramic powder, a binder resin, an organic solvent and a dispersant. Hereinafter, each component contained in the conductive paste according to the present invention, characteristics of the conductive paste, and the like will be described in detail.
本発明に係る導電性ペーストは、導電性粉末、セラミック粉末、バインダー樹脂、有機溶剤および分散剤を含有する。以下、本発明に係る導電性ペーストに含まれる各成分、及び、導電性ペーストの特性などについて、詳細に説明する。 1. 1. Conductive paste The conductive paste according to the present invention contains a conductive powder, a ceramic powder, a binder resin, an organic solvent and a dispersant. Hereinafter, each component contained in the conductive paste according to the present invention, characteristics of the conductive paste, and the like will be described in detail.
（１）導電性粉末
導電性粉末は、材質は特に限定されず、要求される特性に応じて、公知の金属粉末などを適宜選択して用いることができる。また、これらの導電性粉末は、単独または混合して用いてもよい。 (1) Conductive powder The material of the conductive powder is not particularly limited, and a known metal powder or the like can be appropriately selected and used according to the required characteristics. Further, these conductive powders may be used alone or in combination.
導電性粉末は、材質は特に限定されず、要求される特性に応じて、公知の金属粉末などを適宜選択して用いることができる。また、これらの導電性粉末は、単独または混合して用いてもよい。 (1) Conductive powder The material of the conductive powder is not particularly limited, and a known metal powder or the like can be appropriately selected and used according to the required characteristics. Further, these conductive powders may be used alone or in combination.
導電性粉末としては、例えば、ニッケル（Ｎｉ）、銅（Ｃｕ）、銀（Ａｇ）、パラジウム（Ｐｄ）、金（Ａｕ）、白金（Ｐｔ）、及び、これらの合金からなる群より選ばれる１種以上の金属粉末を用いることができ、これらの中でも、導電性、耐食性、価格等の観点から総合的に判断すると、Ｎｉ、Ｃｕ、及び、これらの合金のうち１種以上の金属粉末が好ましく、その中でも、Ｎｉの金属粉末（ニッケル粉末）であることがより好ましい。また、ニッケル粉末は、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程度の硫黄（Ｓ）を含んでもよい。
The conductive powder is selected from the group consisting of, for example, nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), and alloys thereof1. More than one kind of metal powder can be used, and among these, Ni, Cu, and one or more kinds of metal powders among these alloys are preferable from the viewpoint of conductivity, corrosion resistance, price, etc. Among them, Ni metal powder (nickel powder) is more preferable. Further, the nickel powder may contain sulfur (S) of about several hundred ppm in order to suppress rapid gas generation due to partial thermal decomposition of the binder resin during the debinder treatment.
導電性粉末の製造方法は、特に限定されず、例えば、塩化物蒸気を水素ガス中で気相から直接析出させる方法、溶融金属からのアトマイズ法、水溶液を使った噴霧熱分解法、原料の金属塩を水溶液中で還元処理する湿式法等が適用できる。
The method for producing the conductive powder is not particularly limited, and for example, a method of directly precipitating chloride vapor from the gas phase in hydrogen gas, an atomizing method from a molten metal, a spray thermal decomposition method using an aqueous solution, and a metal as a raw material. A wet method or the like in which a salt is reduced in an aqueous solution can be applied.
導電性粉末の平均粒径は、特に限定されず、使用対象の電子部品のサイズ等に応じて選定すればよい。導電性粉末の平均粒径は、例えば、薄膜化の進む積層セラミックコンデンサ用としては、５μｍ以下であることが好ましく、３μｍ以下であることがより好ましい。平均粒径が５μｍを超える場合、内部電極表面の凹凸が激しくなり、コンデンサの電気的特性を劣化させることがあり好ましくない。また、導電性粉末の平均粒径の下限は、特に限定されないが、例えば、０．０５μｍ以上である。平均粒径が０．０５μｍより小さい場合、ハンドリングが極めて困難になり、自然発火等の危険性が生じやすい。
The average particle size of the conductive powder is not particularly limited and may be selected according to the size of the electronic component to be used. The average particle size of the conductive powder is preferably 5 μm or less, and more preferably 3 μm or less, for example, for a multilayer ceramic capacitor whose thinning progresses. If the average particle size exceeds 5 μm, the surface of the internal electrode becomes uneven, which may deteriorate the electrical characteristics of the capacitor, which is not preferable. The lower limit of the average particle size of the conductive powder is not particularly limited, but is, for example, 0.05 μm or more. If the average particle size is smaller than 0.05 μm, handling becomes extremely difficult and a risk of spontaneous combustion or the like is likely to occur.
なお、本明細書において、導電性粉末の平均粒径は、特に断らない限りＢＥＴ法に基づく比表面積を用いて算出した粒径である。例えば、ニッケル粉末の平均粒径を求める算出式は以下の式（１）のとおりである。
In the present specification, the average particle size of the conductive powder is a particle size calculated by using the specific surface area based on the BET method unless otherwise specified. For example, the calculation formula for obtaining the average particle size of nickel powder is as follows (1).
粒径＝６／（Ｓ．Ａ×ρ） ・・・（１）
ρ＝８．９（ｇ／ｃｍ３）：ニッケル粉末の真密度
Ｓ．Ａ：ニッケル粉末の比表面積 Particle size = 6 / (SA × ρ) ・ ・ ・ (1)
ρ = 8.9 (g / cm 3 ): True density of nickel powder S. A: Specific surface area of nickel powder
ρ＝８．９（ｇ／ｃｍ３）：ニッケル粉末の真密度
Ｓ．Ａ：ニッケル粉末の比表面積 Particle size = 6 / (SA × ρ) ・ ・ ・ (1)
ρ = 8.9 (g / cm 3 ): True density of nickel powder S. A: Specific surface area of nickel powder
また、使用する導電性粉末表面の親水性・疎水性の強さによって、溶媒やビヒクルとの濡れ性が変化し、特に微細化の進む微粉の凝集体の解砕や分散性に大きく影響する。導電性粉末表面の親水性・疎水性の強さは、Ｈ２Ｏ吸着量によって評価することができる。
Further, depending on the strength of the hydrophilicity and hydrophobicity of the surface of the conductive powder used, the wettability with the solvent and the vehicle changes, and in particular, it greatly affects the crushing and dispersibility of the agglomerates of the fine powder, which is becoming finer. The strength of hydrophilicity and hydrophobicity of the surface of the conductive powder can be evaluated by the amount of H2O adsorbed.
本実施形態に係る導電性ペーストにおいて、用いられる導電性粉末は、相対圧Ｐ／Ｐ０＝０．５における単位面積当たりのＨ２Ｏ吸着量が０．３０ｍｇ／ｍ２以上０．７０ｍｇ／ｍ２以下であり、０．３０ｍｇ／ｍ２以上０．６０ｍｇ／ｍ２以下であってもよい。Ｈ２Ｏ吸着量が０．３０ｍｇ／ｍ２未満である場合、疎水性が強すぎて、粘度安定性が悪くなる場合がある。これは、比誘電率が高い（親水性が高い）分散剤が導電性粉末に吸着しないために生ずるためと考えられる。また、Ｈ２Ｏ吸着量が０．７０ｍｇ／ｍ２を超える場合、親水性が強くなり過ぎ、粘度安定性が悪くなる場合がある。これは、導電性粉末の比誘電率が高くなりすぎるため、導電性粉末に吸着した分散剤の疎水基が伸びないので、溶剤に馴染みにくくなるために生ずるためと考えられる。
The conductive powder used in the conductive paste according to the present embodiment has an H2O adsorption amount of 0.30 mg / m 2 or more and 0.70 mg / m per unit area at a relative pressure of P / P 0 = 0.5. It may be 2 or less, and may be 0.30 mg / m 2 or more and 0.60 mg / m 2 or less. When the amount of H2O adsorbed is less than 0.30 mg / m 2 , the hydrophobicity may be too strong and the viscosity stability may be deteriorated. It is considered that this is because the dispersant having a high relative permittivity (high hydrophilicity) does not adsorb to the conductive powder. Further, when the H2O adsorption amount exceeds 0.70 mg / m 2 , the hydrophilicity may become too strong and the viscosity stability may deteriorate. It is considered that this is because the relative permittivity of the conductive powder becomes too high, and the hydrophobic group of the dispersant adsorbed on the conductive powder does not extend, so that it becomes difficult to be compatible with the solvent.
また、導電性粉末としてニッケル粉末を用いる場合、その表面組成において、ＮｉＯの割合が２０モル％以上９０モル％以下であることが好ましい。ＮｉＯの割合が上記範囲外である場合、導電性粉末の表面への分散剤の吸着状態が適正でなくなったり、導電性粉末とバインダー樹脂との反応が生じてしまったりする場合がある。導電性粉末表面へ分散剤が十分に吸着しない場合、有機溶媒や有機ビヒクルとの濡れ性が悪化し、導電性粉末の凝集体（２次粒子）の解砕や、解砕後の粒子（１次粒子等）の再凝集の抑制が不十分（すなわち、導電性粉末の分散が不十分）となり、導電性ペーストの粘度安定性が低下したり、乾燥膜の表面平滑性に劣ったりすることがある。
When nickel powder is used as the conductive powder, the proportion of NiO is preferably 20 mol% or more and 90 mol% or less in the surface composition thereof. When the ratio of NiO is out of the above range, the adsorbed state of the dispersant on the surface of the conductive powder may not be appropriate, or the conductive powder may react with the binder resin. If the dispersant is not sufficiently adsorbed on the surface of the conductive powder, the wettability with an organic solvent or an organic vehicle deteriorates, and the aggregates (secondary particles) of the conductive powder are crushed or the crushed particles (1). The suppression of reaggregation of secondary particles, etc.) may be insufficient (that is, the dispersion of the conductive powder may be insufficient), the viscosity stability of the conductive paste may be lowered, or the surface smoothness of the dried film may be poor. be.
また、導電性ペーストの粘度安定性や乾燥膜の表面平滑性をより向上させるという観点から、ニッケル粉末の表面組成におけるＮｉＯの割合は、上記範囲内において、５０モル％以上であってもよく、６０モル％以上であってもよく、７０モル％以上であってもよく、８０モル％以上であってもよい。ＮｉＯの割合が上記範囲内において多いほど、後述する分散剤が少量であっても、高い分散性を有する導電性ペーストを得ることができる。
Further, from the viewpoint of further improving the viscosity stability of the conductive paste and the surface smoothness of the dry film, the proportion of NiO in the surface composition of the nickel powder may be 50 mol% or more within the above range. It may be 60 mol% or more, 70 mol% or more, or 80 mol% or more. The larger the proportion of NiO in the above range, the more a conductive paste having high dispersibility can be obtained even if the amount of the dispersant described later is small.
なお、ニッケル粉末の表面組成におけるＮｉＯの割合は、Ｘ線光電子分光法（ＸＰＳ）を用いて、測定することができる。例えば、ＸＰＳを用いて、ニッケル粉末表面のＮｉ２ｐスペクトルを解析して、Ｎｉピーク、Ｎｉ（ＯＨ）２ピーク、および、ＮｉＯピークが検出された場合、これら３成分のピーク面積全量に対する、ＮｉＯピークの面積比から、ＮｉＯの割合（モル％）を測定することができる。
The proportion of NiO in the surface composition of the nickel powder can be measured by using X-ray photoelectron spectroscopy (XPS). For example, when the Ni2p spectrum on the surface of nickel powder is analyzed using XPS and a Ni peak, a Ni (OH) 2 peak, and a NiO peak are detected, the NiO peak with respect to the total peak area of these three components. From the area ratio, the ratio of NiO (mol%) can be measured.
また、導電性粉末の含有割合は、導電性ペースト全質量に対して、好ましくは３０質量％以上７０質量％以下である。導電性粉末の割合が３０質量％を下回ると焼成後の電極厚みが著しく薄くなり抵抗値が上昇したり、電極膜の形成が不充分で導電性を失い、目的とする静電容量が得られなかったりする場合があるので好ましくない。７０質量％を上回ると電極膜の薄層化が困難となるので好ましくない。ペースト全体に対する導電性粉末の割合は、４０質量％以上６０質量％以下とすることがより好ましい。
Further, the content ratio of the conductive powder is preferably 30% by mass or more and 70% by mass or less with respect to the total mass of the conductive paste. If the proportion of the conductive powder is less than 30% by mass, the thickness of the electrode after firing becomes extremely thin and the resistance value rises, or the formation of the electrode film is insufficient and the conductivity is lost, so that the desired capacitance can be obtained. It is not preferable because it may not be available. If it exceeds 70% by mass, it becomes difficult to thin the electrode film, which is not preferable. The ratio of the conductive powder to the entire paste is more preferably 40% by mass or more and 60% by mass or less.
（２）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を選択することができる。セラミック粉末は、例えば、チタン酸バリウム系、およびジルコン酸ストロンチウム系からなる群より選ばれる少なくとも１種の酸化物粉末を含むことが好ましく、これらの中でも、チタン酸バリウム（ＢａＴｉＯ３、以下、「ＢＴ」と称す場合がある）の粉末を含むことが好ましい。 (2) Ceramic powder The ceramic powder is not particularly limited, and for example, in the case of a paste for an internal electrode of a laminated ceramic capacitor, a known ceramic powder can be appropriately selected depending on the type of the laminated ceramic capacitor to be applied. The ceramic powder preferably contains, for example, at least one oxide powder selected from the group consisting of barium titanate and strontium zirconate, and among these, barium titanate (BaTIO 3 , hereinafter, "BT". It is preferable to contain the powder of).
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を選択することができる。セラミック粉末は、例えば、チタン酸バリウム系、およびジルコン酸ストロンチウム系からなる群より選ばれる少なくとも１種の酸化物粉末を含むことが好ましく、これらの中でも、チタン酸バリウム（ＢａＴｉＯ３、以下、「ＢＴ」と称す場合がある）の粉末を含むことが好ましい。 (2) Ceramic powder The ceramic powder is not particularly limited, and for example, in the case of a paste for an internal electrode of a laminated ceramic capacitor, a known ceramic powder can be appropriately selected depending on the type of the laminated ceramic capacitor to be applied. The ceramic powder preferably contains, for example, at least one oxide powder selected from the group consisting of barium titanate and strontium zirconate, and among these, barium titanate (BaTIO 3 , hereinafter, "BT". It is preferable to contain the powder of).
チタン酸バリウム系の酸化物粉末としては、例えば、チタン酸バリウム（ＢＴ）を主成分として含み、他の酸化物を副成分として含む粉末を用いることができる。副成分である他の酸化物としては、例えば、マンガン（Ｍｎ）、クロム（Ｃｒ）、ケイ素（Ｓｉ）、カルシウム（Ｃａ）、バリウム（Ｂａ）、マグネシウム（Ｍｇ）、バナジウム（Ｖ）、タングステン（Ｗ）、タンタル（Ｔａ）、ニオブ（Ｎｂ）、および希土類元素から選ばれる１種類以の酸化物が挙げられる。また、チタン酸バリウム系の酸化物粉末としては、チタン酸バリウム（ＢａＴｉＯ３）のＢａ原子及び／又はＴｉ原子を他原子、錫（Ｓｎ）、鉛（Ｐｂ）、ジルコニウム（Ｚｒ）などで置換したようなペロブスカイト型酸化物強誘電体の粉末を用いてもよい。
As the barium titanate-based oxide powder, for example, a powder containing barium titanate (BT) as a main component and other oxides as a sub-component can be used. Examples of other oxides as auxiliary components include manganese (Mn), chromium (Cr), silicon (Si), calcium (Ca), barium (Ba), magnesium (Mg), vanadium (V), and tungsten (tungsten). W), tantalum (Ta), niobium (Nb), and one or more oxides selected from rare earth elements can be mentioned. As the barium titanate-based oxide powder, the Ba atom and / or Ti atom of barium titanate (BaTIO 3 ) was replaced with another atom, tin (Sn), lead (Pb), zirconium (Zr), or the like. A powder of a perovskite-type oxide strong dielectric such as above may be used.
セラミック粉末としては、チタン酸バリウム系、およびジルコン酸ストロンチウム系の酸化物粉末以外のその他の粉末を含んでもよく、例えば、積層セラミックデバイスのグリーンシートを形成するセラミック粉末である、酸化亜鉛（ＺｎＯ）、フェライト、チタン・ジルコン酸鉛（ＰＺＴ）、酸化バリウム（ＢａＯ）、酸化アルミニウム（Ａｌ２Ｏ３）、酸化ビスマス（Ｂｉ２Ｏ３）、希土類酸化物、酸化チタン（ＴｉＯ２）、酸化ネオジム（Ｎｄ２Ｏ３）などのセラミック粉末を含有させることもできる。
The ceramic powder may contain other powders other than the barium titanate-based and strontium zirconate-based oxide powders, for example, zinc oxide (ZnO), which is a ceramic powder forming a green sheet of a laminated ceramic device. , Ferrite, Lead Titanium Zirconate (PZT), Barium Oxide (BaO), Aluminum Oxide (Al 2 O 3 ), Bismus Oxide (Bi 2 O 3 ), Rare Earth Oxides, Titanium Oxide (TIO 2 ), Neodim Oxide ( It can also contain a ceramic powder such as Nd 2 O 3 ).
セラミック粉末の平均粒径は、使用対象の電子部品のサイズ等に応じて選定すればよいが、例えば、薄膜化の進む積層電子部品用としては、０．０１μｍ以上０．５μｍ以下の範囲が好ましい。０．５μｍを超えると塗布および乾燥後の膜表面の凹凸が激しくなり、また０．０１μｍより小さくなるとハンドリングが極めて困難になり、自然発火等の危険性も生じやすいため好ましくない。なお、セラミック粉末の平均粒径は、上記の導電性粉末の平均粒径の測定方法と同様、ＢＥＴ法に基づく比表面積を用いて算出した粒径である（例えば、チタン酸バリウムの場合は、ρ＝６．１（ｇ／ｃｍ３）を用いて、上記式（１）から平均粒径が算出される）。
The average particle size of the ceramic powder may be selected according to the size of the electronic component to be used, etc., but for example, for laminated electronic components whose thinning is progressing, the range of 0.01 μm or more and 0.5 μm or less is preferable. .. If it exceeds 0.5 μm, the unevenness of the film surface after coating and drying becomes severe, and if it is smaller than 0.01 μm, handling becomes extremely difficult and there is a risk of spontaneous combustion, which is not preferable. The average particle size of the ceramic powder is the particle size calculated by using the specific surface area based on the BET method, as in the above method for measuring the average particle size of the conductive powder (for example, in the case of barium titanate, the particle size is calculated. Using ρ = 6.1 (g / cm 3 ), the average particle size is calculated from the above formula (1)).
セラミック粉末の含有量は、導電性ペースト全質量に対して、例えば、１質量％以上２０質量％以下であり、より好ましくは５質量％以上２０質量％以下である。
The content of the ceramic powder is, for example, 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 20% by mass or less, based on the total mass of the conductive paste.
（３）バインダー樹脂
バインダー樹脂は、導電性ペーストを印刷する際、適度な粘調性と粘着性を発揮し、印刷性を向上させるほか、乾燥特性などを向上させる効果も有する。 (3) Binder Resin The binder resin exhibits appropriate viscous property and adhesiveness when printing a conductive paste, improves printability, and also has an effect of improving drying characteristics and the like.
バインダー樹脂は、導電性ペーストを印刷する際、適度な粘調性と粘着性を発揮し、印刷性を向上させるほか、乾燥特性などを向上させる効果も有する。 (3) Binder Resin The binder resin exhibits appropriate viscous property and adhesiveness when printing a conductive paste, improves printability, and also has an effect of improving drying characteristics and the like.
バインダー樹脂としては、特に限定されず、要求される特性に応じて公知の材料を用いることができるが、例えば、セルロース系樹脂、ブチラール系樹脂、及び、アクリル樹脂からなる群より選ばれる１種以上を含有することが好ましく、セルロース系樹脂及びブチラール系樹脂からなる群より選ばれる１種以上を含有することがより好ましい。
The binder resin is not particularly limited, and a known material can be used depending on the required properties. For example, one or more selected from the group consisting of a cellulosic resin, a butyral resin, and an acrylic resin. Is preferable, and it is more preferable to contain at least one selected from the group consisting of cellulosic resins and butyral resins.
セルロース系樹脂としては、アセチルセルロース、メチルセルロース、エチルセルロース、ブチルセルロース、及びニトロセルロース、部分エーテル化セルロース類などが挙げられる。また、ブチラール系樹脂としては、ポリビニルブチラールなどが挙げられる。
Examples of the cellulosic resin include acetyl cellulose, methyl cellulose, ethyl cellulose, butyl cellulose, nitrocellulose, and partially etherified celluloses. Examples of the butyral resin include polyvinyl butyral and the like.
中でも、溶剤への溶解性、燃焼分解性の観点などからエチルセルロースを含むことが好ましい。また、積層電子部品用に用いる場合、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、ブチラール系樹脂を単独で使用してもよい。バインダー樹脂は、１種類を用いてもよく、又は、２種類以上を用いてもよい。
Above all, it is preferable to contain ethyl cellulose from the viewpoint of solubility in a solvent and combustion decomposability. When used for laminated electronic components, the butyral resin may be contained or the butyral resin may be used alone from the viewpoint of improving the adhesive strength with the green sheet. One kind of binder resin may be used, or two or more kinds may be used.
バインダー樹脂の含有量は、導電性ペースト全質量に対して、膜強度、脱バインダー性、印刷性、粘度の観点から、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５質量％以下である。
The content of the binder resin is preferably 0.5% by mass or more and 10% by mass or less, more preferably 1 from the viewpoint of film strength, debinderability, printability, and viscosity with respect to the total mass of the conductive paste. It is by mass% or more and 5% by mass or less.
バインダー樹脂の含有量が上記範囲より小さい場合、乾燥膜の強度が低下したり、積層時に導電性ペーストの電極パターン部と誘電体シートとの密着性が悪くなり剥がれやすくなったりすることがある。一方、バインダー樹脂の含有量が上記範囲を超える場合、バインダー樹脂の含有量が多くなり過ぎるため、脱バインダー性が悪化し、バインダー樹脂の一部が残留してしまったりすることがある。
If the content of the binder resin is smaller than the above range, the strength of the dry film may be lowered, or the adhesion between the electrode pattern portion of the conductive paste and the dielectric sheet may be deteriorated at the time of laminating, and it may be easily peeled off. On the other hand, when the content of the binder resin exceeds the above range, the content of the binder resin becomes too large, so that the debinder property deteriorates and a part of the binder resin may remain.
（４）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、導電性粉末を分散させて、導電性ペーストとしての粘度が調整でき、適切な流動性、印刷性、乾燥特性などを付与することができる、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、沸点が１５０℃から２５０℃程度の有機溶剤、テルペン系溶剤、脂肪族炭化水素系溶剤、アルコール類など、各種公知の有機溶剤（非水溶性溶剤）を用いることができる。 (4) Organic solvent The organic solvent is not particularly limited, the binder resin can be dissolved, the conductive powder can be dispersed, the viscosity of the conductive paste can be adjusted, and appropriate fluidity and printability can be adjusted. , A known organic solvent that can impart drying characteristics and the like can be used. As the organic solvent, various known organic solvents (water-insoluble solvents) such as organic solvents having a boiling point of about 150 ° C. to 250 ° C., terpene solvents, aliphatic hydrocarbon solvents, alcohols and the like can be used. ..
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、導電性粉末を分散させて、導電性ペーストとしての粘度が調整でき、適切な流動性、印刷性、乾燥特性などを付与することができる、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、沸点が１５０℃から２５０℃程度の有機溶剤、テルペン系溶剤、脂肪族炭化水素系溶剤、アルコール類など、各種公知の有機溶剤（非水溶性溶剤）を用いることができる。 (4) Organic solvent The organic solvent is not particularly limited, the binder resin can be dissolved, the conductive powder can be dispersed, the viscosity of the conductive paste can be adjusted, and appropriate fluidity and printability can be adjusted. , A known organic solvent that can impart drying characteristics and the like can be used. As the organic solvent, various known organic solvents (water-insoluble solvents) such as organic solvents having a boiling point of about 150 ° C. to 250 ° C., terpene solvents, aliphatic hydrocarbon solvents, alcohols and the like can be used. ..
テルペン系溶剤としては、例えば、ターピネオール、ジヒドロターピネオール、ジヒドロターピニルアセテートが挙げられる。脂肪族炭化水素系溶剤としては、例えば、デカン、トリデカンなどが挙げられる。アルコール類としては、例えば、デカノール、トリデカノールなどが挙げられる。上記以外の沸点が１５０℃から２５０℃程度の有機溶剤としては、例えば、イソボルニルアセテート、ブチルカルビトールアセテート、ジエチレングリコールブチルメチルエーテル、トリプロピレングリコールジメチルエーテルなどが挙げられる。
Examples of the terpene-based solvent include tarpineol, dihydroterpineol, and dihydroterpinyl acetate. Examples of the aliphatic hydrocarbon solvent include decane and tridecane. Examples of alcohols include decanol and tridecanol. Examples of the organic solvent having a boiling point of about 150 ° C. to 250 ° C. other than the above include isobornyl acetate, butyl carbitol acetate, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether and the like.
有機溶剤の含有量は、導電性ペースト全質量に対して、蒸発量、粘性、バインダー樹脂との相溶性、印刷性の観点から、３０質量％以上７０質量％以下が好ましく、４０質量％以上６０質量％以下がより好ましい。
The content of the organic solvent is preferably 30% by mass or more and 70% by mass or less, preferably 40% by mass or more and 60% by mass, based on the total mass of the conductive paste, from the viewpoints of evaporation amount, viscosity, compatibility with the binder resin, and printability. More preferably, it is by mass or less.
導電性ペーストの製造工程において、各材料を混合する順番は特に限定されないが、予め、有機溶剤の一部に、上記バインダー樹脂を溶解して、有機ビヒクルを作製した後、この有機ビヒクルと、他の材料及び残りの有機溶剤（粘度調整用）とを混合することが好ましい。有機ビヒクルに含有されるバインダー樹脂の配合量は、特に限定されないが、小型化の進む電子部品用に用いる導電性ペーストを適正な粘度とする観点から、有機ビヒクル全質量に対して、１質量％以上３０質量％以下とするのが好ましく、５質量％以上２０質量％以下とするのがより好ましい。
In the process of manufacturing the conductive paste, the order in which the materials are mixed is not particularly limited, but the above binder resin is dissolved in a part of the organic solvent in advance to prepare an organic vehicle, and then the organic vehicle and others. It is preferable to mix the material of the above and the remaining organic solvent (for adjusting the viscosity). The blending amount of the binder resin contained in the organic vehicle is not particularly limited, but is 1% by mass with respect to the total mass of the organic vehicle from the viewpoint of making the conductive paste used for electronic parts, which are becoming smaller and smaller, have an appropriate viscosity. It is preferably 30% by mass or less, and more preferably 5% by mass or more and 20% by mass or less.
（５）分散剤
分散剤の役割は、無機粉末（導電性粉末およびセラミック粉末）の表面に吸着し無機粉末同士の凝集を抑制したり、有機ビヒクルとの濡れ性を向上させて導電性ペースト内に分散させたりすることである。分散剤（界面活性剤）は一般に、カチオン系分散剤、アニオン系分散剤、ノニオン系分散剤および両性分散剤に分類される。 (5) Dispersant The role of the dispersant is to adsorb to the surface of the inorganic powder (conductive powder and ceramic powder), suppress the aggregation of the inorganic powders, and improve the wettability with the organic vehicle in the conductive paste. It is to disperse to. Dispersants (surfactants) are generally classified into cationic dispersants, anionic dispersants, nonionic dispersants and amphoteric dispersants.
分散剤の役割は、無機粉末（導電性粉末およびセラミック粉末）の表面に吸着し無機粉末同士の凝集を抑制したり、有機ビヒクルとの濡れ性を向上させて導電性ペースト内に分散させたりすることである。分散剤（界面活性剤）は一般に、カチオン系分散剤、アニオン系分散剤、ノニオン系分散剤および両性分散剤に分類される。 (5) Dispersant The role of the dispersant is to adsorb to the surface of the inorganic powder (conductive powder and ceramic powder), suppress the aggregation of the inorganic powders, and improve the wettability with the organic vehicle in the conductive paste. It is to disperse to. Dispersants (surfactants) are generally classified into cationic dispersants, anionic dispersants, nonionic dispersants and amphoteric dispersants.
無機粉末を分散させるための分散剤としては、アニオン系分散剤（例えば、カルボン酸系分散剤、リン酸系分散剤、リン酸塩系分散剤などの酸系分散剤）が好ましく用いられている。しかしながら、無機粉末の小粒径化に伴い、アニオン系分散剤を用いても、無機粉末が十分に分散しない場合もあった。
As the dispersant for dispersing the inorganic powder, an anionic dispersant (for example, an acid-based dispersant such as a carboxylic acid-based dispersant, a phosphoric acid-based dispersant, or a phosphate-based dispersant) is preferably used. .. However, as the particle size of the inorganic powder is reduced, the inorganic powder may not be sufficiently dispersed even if an anionic dispersant is used.
そこで、本発明者が鋭意研究開発した結果、上述した特定の範囲のＨ２Ｏ吸着量を有する導電性粉末と組み合わせて、比誘電率が１０以上であり、かつ、酸基および／又はアミン基を有する化合物を含む、分散剤を使用することにより、分散性を向上できることを見出した。このような分散剤は、無機粉末表面への吸着力が大きく、無機粉末と有機ビヒクルとの濡れ性が向上するため（前記（１）「濡れ」る工程）、その表面改質作用により無機粉末の解砕を促進させ（前記（２）分散する工程）、かつ、再凝集を抑制すること（前記（３）「再凝集」を抑制する工程）により、分散性を上げるのに寄与すると考えられる。
Therefore, as a result of diligent research and development by the present inventor, in combination with the above-mentioned conductive powder having an H2O adsorption amount in a specific range, the relative permittivity is 10 or more, and an acid group and / or an amine group is used. It has been found that dispersibility can be improved by using a dispersant containing a compound having. Since such a dispersant has a large adsorption force on the surface of the inorganic powder and the wettability between the inorganic powder and the organic vehicle is improved ((1) "wetting" step), the surface modifying action of the dispersant makes the inorganic powder. It is considered that it contributes to the improvement of dispersibility by promoting the crushing of the above ((2) dispersal step) and suppressing reaggregation ((3) "reaggregation" suppressing step). ..
分散剤の比誘電率は、１０以上であればよく、１１以上であってもよく、１２以上であってもよい。比誘電率が上記範囲を満たす分散剤を使用することにより、塗膜（乾燥膜）の平滑性や乾燥膜密度を向上させることができる。なお、本明細書で用いる分散剤の比誘電率は、２０℃における比誘電率を示す。また、比誘電率は、液体試料用の電極セルに評価用試料（使用する分散剤）を入れて測定することができる。なお、分散剤の比誘電率の上限は特に限定されないが、例えば、１５以下程度である。
The relative permittivity of the dispersant may be 10 or more, 11 or more, or 12 or more. By using a dispersant having a relative permittivity satisfying the above range, the smoothness of the coating film (dry film) and the density of the dry film can be improved. The relative permittivity of the dispersant used in the present specification indicates the relative permittivity at 20 ° C. Further, the relative permittivity can be measured by putting an evaluation sample (dispersant used) in an electrode cell for a liquid sample. The upper limit of the relative permittivity of the dispersant is not particularly limited, but is, for example, about 15 or less.
また、分散剤は、（１）酸基を有する化合物、及び、（２）アミン基を有する化合物からなる群より選ばれる少なくとも１種類の化合物を含有する。また、分散剤は、上記（１）酸基を有する化合物、および（２）アミン基を有する化合物の両方に該当する化合物、すなわち、（３）酸基とアミン基を同一分子内に有する化合物であってもよく、（１）酸基を有する化合物と、（２）アミン基を有する化合物との両方の化合物を含む混合物であってもよい。
Further, the dispersant contains at least one compound selected from the group consisting of (1) a compound having an acid group and (2) a compound having an amine group. The dispersant is a compound corresponding to both (1) a compound having an acid group and (2) a compound having an amine group, that is, (3) a compound having an acid group and an amine group in the same molecule. It may be a mixture containing both (1) a compound having an acid group and (2) a compound having an amine group.
酸基を有する化合物としては、カルボキシル基およびリン酸基の少なくとも一方を含む化合物が好ましい。また、アミン基を有する化合物とは、第１級アミン、第２級アミン、及び、第３級アミンを含む。
As the compound having an acid group, a compound containing at least one of a carboxyl group and a phosphoric acid group is preferable. Further, the compound having an amine group includes a primary amine, a secondary amine, and a tertiary amine.
また、分散剤は、アミン価が１００以上の分散剤を含むことがより好ましい。アミン価が１００以上の分散剤を用いる場合、導電性ペーストの分散性がより向上し、塗布後の乾燥膜表面の平滑性をより向上させることができる。
Further, it is more preferable that the dispersant contains a dispersant having an amine value of 100 or more. When a dispersant having an amine value of 100 or more is used, the dispersibility of the conductive paste can be further improved, and the smoothness of the surface of the dried film after coating can be further improved.
また、分散剤は、酸基を有する化合物を含む場合、酸基を有する分散剤の酸価は、３０以上３００以下であってもよく、３０以上２００以下であってもよい。
Further, when the dispersant contains a compound having an acid group, the acid value of the dispersant having an acid group may be 30 or more and 300 or less, or 30 or more and 200 or less.
分散剤の含有量は、導電性ペースト全質量に対して、好ましくは０．１質量％以上２．０質量％以下、より好ましくは０．３質量％以上１．０質量％以下である。分散剤の含有量が０．１質量％未満であると、分散剤の含有量が少なすぎて、解砕、再凝集抑制の効果が得られないことがある。一方、分散剤の含有量が２．０質量％超であると、印刷性等のペースト特性が大幅に変わることがあり、望ましくない。
The content of the dispersant is preferably 0.1% by mass or more and 2.0% by mass or less, and more preferably 0.3% by mass or more and 1.0% by mass or less with respect to the total mass of the conductive paste. If the content of the dispersant is less than 0.1% by mass, the content of the dispersant may be too small to obtain the effect of suppressing crushing and reaggregation. On the other hand, if the content of the dispersant is more than 2.0% by mass, the paste characteristics such as printability may be significantly changed, which is not desirable.
（６）その他の添加成分
本発明の導電性ペーストには、本発明の趣旨を逸脱しない範囲内で、必要に応じて消泡剤、可塑剤、増粘剤、キレート剤、上記分散剤以外の分散剤、チクソ剤などの公知の添加物を１種以上、添加してもよい。 (6) Other Additives The conductive paste of the present invention contains, if necessary, a defoaming agent, a plasticizer, a thickener, a chelating agent, and a dispersant other than the above-mentioned dispersant, within the range not deviating from the gist of the present invention. One or more known additives such as a dispersant and a thickening agent may be added.
本発明の導電性ペーストには、本発明の趣旨を逸脱しない範囲内で、必要に応じて消泡剤、可塑剤、増粘剤、キレート剤、上記分散剤以外の分散剤、チクソ剤などの公知の添加物を１種以上、添加してもよい。 (6) Other Additives The conductive paste of the present invention contains, if necessary, a defoaming agent, a plasticizer, a thickener, a chelating agent, and a dispersant other than the above-mentioned dispersant, within the range not deviating from the gist of the present invention. One or more known additives such as a dispersant and a thickening agent may be added.
（７）導電性ペーストの製造方法、および特性
（製造方法）
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、公知の方法を用いて製造することができる。例えば、導電性ペーストは、上記の各材料をミキサ、ボールミル、ニーダ、ロールミルなどの装置により混練、及び分散を行い、スラリー化することにより製造される。 (7) Manufacturing method and characteristics (manufacturing method) of conductive paste
The method for producing the conductive paste according to the present embodiment is not particularly limited, and the conductive paste can be produced by using a known method. For example, the conductive paste is produced by kneading and dispersing each of the above materials with an apparatus such as a mixer, a ball mill, a kneader, and a roll mill to form a slurry.
（製造方法）
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、公知の方法を用いて製造することができる。例えば、導電性ペーストは、上記の各材料をミキサ、ボールミル、ニーダ、ロールミルなどの装置により混練、及び分散を行い、スラリー化することにより製造される。 (7) Manufacturing method and characteristics (manufacturing method) of conductive paste
The method for producing the conductive paste according to the present embodiment is not particularly limited, and the conductive paste can be produced by using a known method. For example, the conductive paste is produced by kneading and dispersing each of the above materials with an apparatus such as a mixer, a ball mill, a kneader, and a roll mill to form a slurry.
（粘度変化率）
本実施形態に係る導電性ペーストは、製造後２５℃で３０日間静置し、ブルックフィールド粘度計にて２５℃、１０ｒｐｍの条件にて測定した際の粘度（η３０）の変化率が、製造８時間後の粘度（η０）に対して、±１０％以下であることが好ましい。導電性ペーストの粘度の変化率が上記範囲内である場合、導電性ペーストの分散性に優れる。 (Viscosity change rate)
The conductive paste according to this embodiment is left to stand at 25 ° C. for 30 days after production, and the rate of change in viscosity (η 30 ) when measured with a Brookfield viscometer at 25 ° C. and 10 rpm is the production rate. It is preferably ± 10% or less with respect to the viscosity (η 0 ) after 8 hours. When the rate of change in the viscosity of the conductive paste is within the above range, the dispersibility of the conductive paste is excellent.
本実施形態に係る導電性ペーストは、製造後２５℃で３０日間静置し、ブルックフィールド粘度計にて２５℃、１０ｒｐｍの条件にて測定した際の粘度（η３０）の変化率が、製造８時間後の粘度（η０）に対して、±１０％以下であることが好ましい。導電性ペーストの粘度の変化率が上記範囲内である場合、導電性ペーストの分散性に優れる。 (Viscosity change rate)
The conductive paste according to this embodiment is left to stand at 25 ° C. for 30 days after production, and the rate of change in viscosity (η 30 ) when measured with a Brookfield viscometer at 25 ° C. and 10 rpm is the production rate. It is preferably ± 10% or less with respect to the viscosity (η 0 ) after 8 hours. When the rate of change in the viscosity of the conductive paste is within the above range, the dispersibility of the conductive paste is excellent.
なお、３０日間静置後の導電性ペーストの粘度変化率は、以下の式（２）で求めることができる。
The rate of change in viscosity of the conductive paste after standing for 30 days can be calculated by the following formula (2).
粘度変化率（％）＝（η３０－η０）／η０×１００・・・（２）
η３０：３０日後の１０ｒｐｍ粘度
η０：製造８時間後の１０ｒｐｍ粘度（初期粘度） Viscosity change rate (%) = (η 30 -η 0 ) / η 0 × 100 ... (2)
η 30 : 10 rpm viscosity after 30 days η 0 : 10 rpm viscosity after 8 hours of manufacture (initial viscosity)
η３０：３０日後の１０ｒｐｍ粘度
η０：製造８時間後の１０ｒｐｍ粘度（初期粘度） Viscosity change rate (%) = (η 30 -η 0 ) / η 0 × 100 ... (2)
η 30 : 10 rpm viscosity after 30 days η 0 : 10 rpm viscosity after 8 hours of manufacture (initial viscosity)
（光沢度）
本実施形態に係る導電性ペーストは、その乾燥膜の光沢度が１０以上であることが好ましく、１５以上であることが好ましく、２０以上であることがさらに好ましい。乾燥膜の光沢度が高いほど、乾燥膜の表面全体の乱反射が少なく、より平滑な表面が得られていることを示す。 (Glossiness)
The glossiness of the dried film of the conductive paste according to the present embodiment is preferably 10 or more, preferably 15 or more, and further preferably 20 or more. The higher the glossiness of the dried film, the less diffused reflection on the entire surface of the dried film, indicating that a smoother surface is obtained.
本実施形態に係る導電性ペーストは、その乾燥膜の光沢度が１０以上であることが好ましく、１５以上であることが好ましく、２０以上であることがさらに好ましい。乾燥膜の光沢度が高いほど、乾燥膜の表面全体の乱反射が少なく、より平滑な表面が得られていることを示す。 (Glossiness)
The glossiness of the dried film of the conductive paste according to the present embodiment is preferably 10 or more, preferably 15 or more, and further preferably 20 or more. The higher the glossiness of the dried film, the less diffused reflection on the entire surface of the dried film, indicating that a smoother surface is obtained.
なお、評価用の乾燥膜は、例えば、導電性ペーストをＰＥＴフィルム上に５×１０ｃｍの面積で膜厚３０μｍとなるように印刷した後、１２０℃で４０分間、空気中で乾燥させて得ることができる。
The dry film for evaluation is obtained, for example, by printing a conductive paste on a PET film with an area of 5 × 10 cm and a film thickness of 30 μm, and then drying the film at 120 ° C. for 40 minutes in the air. Can be done.
２．積層セラミックコンデンサ
以下、本発明に係る積層セラミックコンデンサ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１などに示す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。 2. 2. Multilayer Ceramic Capacitor Hereinafter, embodiments of the monolithic ceramic capacitor according to the present invention will be described with reference to the drawings. In the drawings, it may be expressed schematically or may be expressed by changing the scale 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 FIG. 1 and the like. 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).
以下、本発明に係る積層セラミックコンデンサ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１などに示す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。 2. 2. Multilayer Ceramic Capacitor Hereinafter, embodiments of the monolithic ceramic capacitor according to the present invention will be described with reference to the drawings. In the drawings, it may be expressed schematically or may be expressed by changing the scale 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 FIG. 1 and the like. 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を交互に積層したセラミック積層体１０と外部電極２０とを備える。
FIGS. 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 ceramic 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 and dried to form a dry film. A plurality of ceramic green sheets having the dried film on the upper surface are laminated by pressure bonding to obtain a laminated body, and then the laminated body is fired to be integrated, whereby the internal electrode layer 11 and the dielectric layer 12 alternate. The 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 the 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 laminated 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、セラミックグリーンシートの片面に乾燥膜を形成したものを複数枚、用意する。なお、導電性ペーストから形成される乾燥膜の厚みは、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, a plurality of ceramic green sheets having a dry film formed on one side of the ceramic green sheet were prepared by printing and applying the above-mentioned conductive paste on one side of the ceramic green sheet using a gravure printing method. do. The thickness of the dried film formed from the conductive paste 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 and pressure treatment. In addition, a protective ceramic green sheet to which the conductive paste is not applied may be further arranged on both sides of the laminated body.
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、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 a green chip, the green chip is subjected to a debinder treatment and fired in a reducing atmosphere to produce a laminated ceramic fired body (ceramic laminate 10). do. The atmosphere in the debinder treatment is preferably an atmosphere or an N2 gas atmosphere. The temperature at which the debindering 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 during the debindering treatment is 0.5 hours or more and 24 hours or less. 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, and the firing is performed. 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、セラミック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。また乾燥膜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、内部電極層１１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 ceramic 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 dry film is removed, and nickel powder or an alloy powder containing nickel as a main component is sintered or melted and integrated to form an internal electrode layer 11, 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 taking oxygen into the inside of the dielectric layer to improve reliability and suppressing reoxidation of the internal electrode, 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.
［評価項目およびその方法］
（１）導電性ペーストの経時粘度変化率
導電性ペーストの経時粘度変化率は、下記の式（２）に示すように、まず、製造８時間後の導電性ペーストの粘度を初期粘度（η０）として測定し、次いで、常温(２５℃)で１日、１０日および３０日間静置した後の導電性ペーストの粘度（ηｘ）をそれぞれ測定した後、それぞれの日数静置した後の粘度の変化量を初期粘度（η０）で割った百分率（％）で表される。３０日後の粘度変化率だけでなく、１日後、１０日後の粘度変化率を測定することにより、粘度変化の傾向も確認した。 [Evaluation items and methods]
(1) Rate of change in viscosity of conductive paste over time As shown in the following formula (2), the rate of change in viscosity of conductive paste over time is determined by first determining the viscosity of the conductive paste after 8 hours of production as the initial viscosity (η 0 ). ), Then the viscosity (η x ) of the conductive paste after being allowed to stand at room temperature (25 ° C) for 1 day, 10 days and 30 days, respectively, and then the viscosity after being allowed to stand for each number of days. It is expressed as a percentage (%) obtained by dividing the amount of change in the initial viscosity (η 0 ). By measuring not only the viscosity change rate after 30 days but also the viscosity change rate after 1 day and 10 days, the tendency of the viscosity change was confirmed.
（１）導電性ペーストの経時粘度変化率
導電性ペーストの経時粘度変化率は、下記の式（２）に示すように、まず、製造８時間後の導電性ペーストの粘度を初期粘度（η０）として測定し、次いで、常温(２５℃)で１日、１０日および３０日間静置した後の導電性ペーストの粘度（ηｘ）をそれぞれ測定した後、それぞれの日数静置した後の粘度の変化量を初期粘度（η０）で割った百分率（％）で表される。３０日後の粘度変化率だけでなく、１日後、１０日後の粘度変化率を測定することにより、粘度変化の傾向も確認した。 [Evaluation items and methods]
(1) Rate of change in viscosity of conductive paste over time As shown in the following formula (2), the rate of change in viscosity of conductive paste over time is determined by first determining the viscosity of the conductive paste after 8 hours of production as the initial viscosity (η 0 ). ), Then the viscosity (η x ) of the conductive paste after being allowed to stand at room temperature (25 ° C) for 1 day, 10 days and 30 days, respectively, and then the viscosity after being allowed to stand for each number of days. It is expressed as a percentage (%) obtained by dividing the amount of change in the initial viscosity (η 0 ). By measuring not only the viscosity change rate after 30 days but also the viscosity change rate after 1 day and 10 days, the tendency of the viscosity change was confirmed.
粘度変化率（％）＝（ηｘ－η０）／η０×１００ ・・・（２）
ηｘ：Ｘ日後の１０ｒｐｍ粘度
η０：製造８時間後の１０ｒｐｍ粘度（初期粘度） Viscosity change rate (%) = (η x −η 0 ) / η 0 × 100 ・ ・ ・ (2)
η x : 10 rpm viscosity after X days η 0 : 10 rpm viscosity after 8 hours of manufacture (initial viscosity)
ηｘ：Ｘ日後の１０ｒｐｍ粘度
η０：製造８時間後の１０ｒｐｍ粘度（初期粘度） Viscosity change rate (%) = (η x −η 0 ) / η 0 × 100 ・ ・ ・ (2)
η x : 10 rpm viscosity after X days η 0 : 10 rpm viscosity after 8 hours of manufacture (initial viscosity)
なお、それぞれの導電性ペーストの粘度は、ブルックフィールド社製Ｂ型粘度計を用いて、２５℃、１０ｒｐｍ（ずり速度＝４ｓｅｃ－１）の条件で測定される。導電性ペーストの経時粘度変化率は少ないほど好ましい。
The viscosity of each conductive paste is measured using a B-type viscometer manufactured by Brookfield Co., Ltd. under the conditions of 25 ° C. and 10 rpm (slip speed = 4 sec -1 ). The smaller the rate of change in viscosity of the conductive paste over time, the more preferable.
（２）乾燥膜表面の平滑性（光沢度）
乾燥膜表面の平滑性の指標として、以下の方法で測定した値（光沢度）を評価した。 (2) Smoothness (glossiness) of the surface of the dried film
As an index of the smoothness of the dry film surface, the value (glossiness) measured by the following method was evaluated.
乾燥膜表面の平滑性の指標として、以下の方法で測定した値（光沢度）を評価した。 (2) Smoothness (glossiness) of the surface of the dried film
As an index of the smoothness of the dry film surface, the value (glossiness) measured by the following method was evaluated.
まず、導電性ペーストをＰＥＴフィルム上に５×１０ｃｍの面積で膜厚３０μｍとなるように印刷した後、１２０℃で４０分間、空気中で乾燥させ、乾燥膜（乾燥後の導電性ペースト）を得た。得られた乾燥膜の表面に対し、入射角６０°の時の光沢度を、光沢度計（堀場製作所製グロスチェッカー；ＩＧ―３２０）を用いて測定した。光沢度が高いほど乱反射が少なく、より平滑な表面が得られていることを示す。
First, the conductive paste is printed on a PET film with an area of 5 × 10 cm and a film thickness of 30 μm, and then dried in air at 120 ° C. for 40 minutes to form a dried film (dried conductive paste). Obtained. The glossiness of the obtained dried film at an incident angle of 60 ° was measured with a glossiness meter (Gloss Checker manufactured by HORIBA, Ltd .; IG-320). The higher the glossiness, the less diffused reflection is, indicating that a smoother surface is obtained.
（３）Ｈ２Ｏ吸着量
評価用試料（導電性粉末）を２５℃で８時間、真空脱気を行った後、高精度蒸気吸着量測定装置ＢＥＬＳＯＲＰ－ａｑｕａ３（マイクロトラック・ベル（株））を用いてＨ２Ｏ吸着等温線を測定し、相対圧Ｐ／Ｐ０＝０．５の時のＨ２Ｏ吸着量を求めた。また、窒素吸着法によるＢＥＴ法を用いて、評価用試料の比表面積値を求めた。得られたＨ２Ｏ吸着量を比表面積値で割ることにより、単位面積当たりのＨ２Ｏ吸着量を算出した。 (3) After vacuum degassing the H 2 O adsorption amount evaluation sample (conductive powder) at 25 ° C. for 8 hours, the high-precision steam adsorption amount measuring device BELSORP-aqua3 (Microtrac Bell Co., Ltd.) The H 2 O adsorption isotherm was measured using the above, and the amount of H 2 O adsorption when the relative pressure P / P 0 = 0.5 was determined. In addition, the specific surface area value of the evaluation sample was determined by using the BET method based on the nitrogen adsorption method. The H 2 O adsorption amount per unit area was calculated by dividing the obtained H 2 O adsorption amount by the specific surface area value.
評価用試料（導電性粉末）を２５℃で８時間、真空脱気を行った後、高精度蒸気吸着量測定装置ＢＥＬＳＯＲＰ－ａｑｕａ３（マイクロトラック・ベル（株））を用いてＨ２Ｏ吸着等温線を測定し、相対圧Ｐ／Ｐ０＝０．５の時のＨ２Ｏ吸着量を求めた。また、窒素吸着法によるＢＥＴ法を用いて、評価用試料の比表面積値を求めた。得られたＨ２Ｏ吸着量を比表面積値で割ることにより、単位面積当たりのＨ２Ｏ吸着量を算出した。 (3) After vacuum degassing the H 2 O adsorption amount evaluation sample (conductive powder) at 25 ° C. for 8 hours, the high-precision steam adsorption amount measuring device BELSORP-aqua3 (Microtrac Bell Co., Ltd.) The H 2 O adsorption isotherm was measured using the above, and the amount of H 2 O adsorption when the relative pressure P / P 0 = 0.5 was determined. In addition, the specific surface area value of the evaluation sample was determined by using the BET method based on the nitrogen adsorption method. The H 2 O adsorption amount per unit area was calculated by dividing the obtained H 2 O adsorption amount by the specific surface area value.
（４）ニッケル粉末表面のＮｉＯの割合
導電性粉末として使用したニッケル粉末の表面を、Ｘ線光電子分光法（ＸＰＳ）で測定し、水酸化ニッケル（Ｎｉ（ＯＨ）２）、酸化ニッケル（ＮｉＯ）に帰属されるニッケル、及び金属ニッケルのピークを検出し、それぞれの存在割合からＮｉＯの割合（モル％）を算出した。 (4) Ratio of NiO on the surface of nickel powder The surface of the nickel powder used as the conductive powder was measured by X-ray photoelectron spectroscopy (XPS), and nickel hydroxide (Ni (OH) 2 ) and nickel oxide (NiO) were measured. The peaks of nickel and metallic nickel attributed to NiO were detected, and the ratio of NiO (mol%) was calculated from the respective abundance ratios.
導電性粉末として使用したニッケル粉末の表面を、Ｘ線光電子分光法（ＸＰＳ）で測定し、水酸化ニッケル（Ｎｉ（ＯＨ）２）、酸化ニッケル（ＮｉＯ）に帰属されるニッケル、及び金属ニッケルのピークを検出し、それぞれの存在割合からＮｉＯの割合（モル％）を算出した。 (4) Ratio of NiO on the surface of nickel powder The surface of the nickel powder used as the conductive powder was measured by X-ray photoelectron spectroscopy (XPS), and nickel hydroxide (Ni (OH) 2 ) and nickel oxide (NiO) were measured. The peaks of nickel and metallic nickel attributed to NiO were detected, and the ratio of NiO (mol%) was calculated from the respective abundance ratios.
（５）分散剤の比誘電率
使用する分散剤を液体試料用の電極セルに入れ、周波数：１ＭＨｚ、電圧：１Ｖの条件下でＬＣＲメータ（ＨＰ－４２７８Ａ)を使って比誘電率を求めた。 (5) Relative Permittivity of Dispersant The dispersant to be used was placed in an electrode cell for a liquid sample, and the relative permittivity was determined using an LCR meter (HP-4278A) under the conditions of frequency: 1 MHz and voltage: 1 V. ..
使用する分散剤を液体試料用の電極セルに入れ、周波数：１ＭＨｚ、電圧：１Ｖの条件下でＬＣＲメータ（ＨＰ－４２７８Ａ)を使って比誘電率を求めた。 (5) Relative Permittivity of Dispersant The dispersant to be used was placed in an electrode cell for a liquid sample, and the relative permittivity was determined using an LCR meter (HP-4278A) under the conditions of frequency: 1 MHz and voltage: 1 V. ..
［実施例１］
導電性粉末として、ニッケル粉末（Ｈ２Ｏ吸着量０．３１ｍｇ／ｍ２、ＮｉＯの表面存在割合３４モル％、粒径０．４μｍ）を４７質量％、セラミック粉末としてチタン酸バリウム（粒径０．０５μｍ）を４．７質量％、有機ビヒクルを２６．６７質量％、分散剤を０．４質量％、残部の有機溶剤を２１．２３質量％、配合した。 [Example 1]
As a conductive powder, nickel powder ( H2O adsorption amount 0.31 mg / m 2 , NiO surface abundance ratio 34 mol%, particle size 0.4 μm) was 47% by mass, and as a ceramic powder, barium titanate (particle size 0). .05 μm) was added in an amount of 4.7% by mass, an organic vehicle was added in an amount of 26.67% by mass, a dispersant was added in an amount of 0.4% by mass, and the balance of an organic solvent was added in an amount of 21.23% by mass.
導電性粉末として、ニッケル粉末（Ｈ２Ｏ吸着量０．３１ｍｇ／ｍ２、ＮｉＯの表面存在割合３４モル％、粒径０．４μｍ）を４７質量％、セラミック粉末としてチタン酸バリウム（粒径０．０５μｍ）を４．７質量％、有機ビヒクルを２６．６７質量％、分散剤を０．４質量％、残部の有機溶剤を２１．２３質量％、配合した。 [Example 1]
As a conductive powder, nickel powder ( H2O adsorption amount 0.31 mg / m 2 , NiO surface abundance ratio 34 mol%, particle size 0.4 μm) was 47% by mass, and as a ceramic powder, barium titanate (particle size 0). .05 μm) was added in an amount of 4.7% by mass, an organic vehicle was added in an amount of 26.67% by mass, a dispersant was added in an amount of 0.4% by mass, and the balance of an organic solvent was added in an amount of 21.23% by mass.
有機ビヒクルは、バインダー樹脂としてエチルセルロースを１３質量％、有機溶剤としてターピネオールを８７質量％配合し、６０℃で加熱混合して作製したものを用いた。
The organic vehicle used was prepared by blending 13% by mass of ethyl cellulose as a binder resin and 87% by mass of tarpineol as an organic solvent and heating and mixing at 60 ° C.
分散剤は、比誘電率が１２．５、酸価５８、アミン価１１０のアミン系分散剤（酸基を有する化合物とアミン基を有する化合物の混合物）を用いた。
As the dispersant, an amine-based dispersant having a relative permittivity of 12.5, an acid value of 58, and an amine value of 110 (a mixture of a compound having an acid group and a compound having an amine group) was used.
有機溶剤としては、ターピネオールを用いた。
Tarpineol was used as the organic solvent.
これらの材料を、２５℃、相対湿度５５％、の環境下、３本ロールミルで混錬および分散を行い、導電性ペーストを作製した。作製した導電性ペーストの初期粘度および所定の経時後の粘度を測定し、それぞれの経時における粘度変化率を算出した。また、作製した導電性ペーストを用いて作製した乾燥膜の光沢度を測定した。
These materials were kneaded and dispersed in a three-roll mill in an environment of 25 ° C. and a relative humidity of 55% to prepare a conductive paste. The initial viscosity of the prepared conductive paste and the viscosity after a predetermined period of time were measured, and the rate of change in viscosity with time was calculated. Moreover, the glossiness of the dry film prepared using the prepared conductive paste was measured.
用いた各材料の種類や含有量などを表１に、表２に測定結果および算出結果を示す。
Table 1 shows the types and contents of each material used, and Table 2 shows the measurement results and calculation results.
［実施例２］
導電性粉末として、Ｈ２Ｏ吸着量０．５３ｍｇ／ｍ２、ＮｉＯの表面存在割合２６モル％、粒径０．２μｍのニッケル粉末を用い、分散剤の含有量を０．６質量％とし、有機溶剤をジヒドロターピニルアセテートとして残部含有量を２１．０３質量％とした以外は実施例１と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例３］
導電性粉末として、Ｈ２Ｏ吸着量０．４２ｍｇ／ｍ２、ＮｉＯの表面存在割合４５モル％、粒径０．０８μｍのニッケル粉末を用い、セラミック粉末として粒径０．０２μｍのＢＴを用い、分散剤の含有量を１．５質量％とし、有機溶剤の残部含有量を２０．１３質量％とした以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例４］
分散剤として比誘電率が１１．４、酸価１２９のカルボキシル基を有する酸系分散剤を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例５］
導電性粉末として、Ｈ２Ｏ吸着量０．４２ｍｇ／ｍ２、ＮｉＯの表面存在割合４５モル％、粒径０．０８μｍのニッケル粉末を用い、セラミック粉末として粒径０．０２μｍのＢＴを用い、分散剤の含有量を１．５質量％とし、有機溶剤の残部含有量を２０．１３質量％とした以外は実施例４と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例６］
分散剤の含有量を１．５質量％とし、有機溶剤の残部含有量を２０．１３質量％とした以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例７］
導電性粉末として、Ｈ２Ｏ吸着量０．３４ｍｇ／ｍ２、ＮｉＯの表面存在割合７９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例６と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例８］
導電性粉末として、Ｈ２Ｏ吸着量０．３８ｍｇ／ｍ２、ＮｉＯの表面存在割合８９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。 [Example 2]
As the conductive powder, nickel powder having an H2O adsorption amount of 0.53 mg / m 2 , a NiO surface presence ratio of 26 mol%, and a particle size of 0.2 μm was used, and the dispersant content was 0.6% by mass. A conductive paste was prepared in the same manner as in Example 1 except that the organic solvent was dihydroterpinyl acetate and the residual content was 21.03% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 3]
Nickel powder having an H2O adsorption amount of 0.42 mg / m 2 , a surface presence ratio of NiO of 45 mol%, and a particle size of 0.08 μm was used as the conductive powder, and BT having a particle size of 0.02 μm was used as the ceramic powder. A conductive paste was prepared in the same manner as in Example 2 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 4]
A conductive paste was prepared in the same manner as in Example 2 except that an acid-based dispersant having a carboxyl group having a relative permittivity of 11.4 and an acid value of 129 was used as the dispersant. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 5]
Nickel powder having an H2O adsorption amount of 0.42 mg / m 2 , a surface presence ratio of NiO of 45 mol%, and a particle size of 0.08 μm was used as the conductive powder, and BT having a particle size of 0.02 μm was used as the ceramic powder. A conductive paste was prepared in the same manner as in Example 4 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 6]
A conductive paste was prepared in the same manner as in Example 2 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 7]
As the conductive powder, the conductive paste was used in the same manner as in Example 6 except that nickel powder having an H2O adsorption amount of 0.34 mg / m 2 , a surface presence ratio of NiO of 79 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 8]
As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.38 mg / m 2 , a surface abundance ratio of NiO of 89 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
導電性粉末として、Ｈ２Ｏ吸着量０．５３ｍｇ／ｍ２、ＮｉＯの表面存在割合２６モル％、粒径０．２μｍのニッケル粉末を用い、分散剤の含有量を０．６質量％とし、有機溶剤をジヒドロターピニルアセテートとして残部含有量を２１．０３質量％とした以外は実施例１と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例３］
導電性粉末として、Ｈ２Ｏ吸着量０．４２ｍｇ／ｍ２、ＮｉＯの表面存在割合４５モル％、粒径０．０８μｍのニッケル粉末を用い、セラミック粉末として粒径０．０２μｍのＢＴを用い、分散剤の含有量を１．５質量％とし、有機溶剤の残部含有量を２０．１３質量％とした以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例４］
分散剤として比誘電率が１１．４、酸価１２９のカルボキシル基を有する酸系分散剤を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例５］
導電性粉末として、Ｈ２Ｏ吸着量０．４２ｍｇ／ｍ２、ＮｉＯの表面存在割合４５モル％、粒径０．０８μｍのニッケル粉末を用い、セラミック粉末として粒径０．０２μｍのＢＴを用い、分散剤の含有量を１．５質量％とし、有機溶剤の残部含有量を２０．１３質量％とした以外は実施例４と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例６］
分散剤の含有量を１．５質量％とし、有機溶剤の残部含有量を２０．１３質量％とした以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例７］
導電性粉末として、Ｈ２Ｏ吸着量０．３４ｍｇ／ｍ２、ＮｉＯの表面存在割合７９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例６と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［実施例８］
導電性粉末として、Ｈ２Ｏ吸着量０．３８ｍｇ／ｍ２、ＮｉＯの表面存在割合８９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。 [Example 2]
As the conductive powder, nickel powder having an H2O adsorption amount of 0.53 mg / m 2 , a NiO surface presence ratio of 26 mol%, and a particle size of 0.2 μm was used, and the dispersant content was 0.6% by mass. A conductive paste was prepared in the same manner as in Example 1 except that the organic solvent was dihydroterpinyl acetate and the residual content was 21.03% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 3]
Nickel powder having an H2O adsorption amount of 0.42 mg / m 2 , a surface presence ratio of NiO of 45 mol%, and a particle size of 0.08 μm was used as the conductive powder, and BT having a particle size of 0.02 μm was used as the ceramic powder. A conductive paste was prepared in the same manner as in Example 2 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 4]
A conductive paste was prepared in the same manner as in Example 2 except that an acid-based dispersant having a carboxyl group having a relative permittivity of 11.4 and an acid value of 129 was used as the dispersant. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 5]
Nickel powder having an H2O adsorption amount of 0.42 mg / m 2 , a surface presence ratio of NiO of 45 mol%, and a particle size of 0.08 μm was used as the conductive powder, and BT having a particle size of 0.02 μm was used as the ceramic powder. A conductive paste was prepared in the same manner as in Example 4 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 6]
A conductive paste was prepared in the same manner as in Example 2 except that the content of the dispersant was 1.5% by mass and the residual content of the organic solvent was 20.13% by mass. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 7]
As the conductive powder, the conductive paste was used in the same manner as in Example 6 except that nickel powder having an H2O adsorption amount of 0.34 mg / m 2 , a surface presence ratio of NiO of 79 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Example 8]
As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.38 mg / m 2 , a surface abundance ratio of NiO of 89 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
［比較例１］
分散剤として比誘電率が３．０、酸価５３、アミン価４８のアミン基を有する分散剤（酸基を有する化合物とアミン基を有する化合物の混合物）を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例２］
分散剤として比誘電率が８．５、酸価６０、アミン価６０のアミン基を有する分散剤（酸基を有する化合物とアミン基を有する化合物の混合物）を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例３］
導電性粉末として、Ｈ２Ｏ吸着量０．２９ｍｇ／ｍ２、ＮｉＯの表面存在割合４９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例４］
導電性粉末として、Ｈ２Ｏ吸着量０．２９ｍｇ／ｍ２、ＮｉＯの表面存在割合４９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例６と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例５］
導電性粉末として、Ｈ２Ｏ吸着量０．７１ｍｇ／ｍ２、ＮｉＯの表面存在割合４２モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。 [Comparative Example 1]
Same as Example 2 except that a dispersant having an amine group having a specific dielectric constant of 3.0, an acid value of 53, and an amine value of 48 (a mixture of a compound having an acid group and a compound having an amine group) was used as the dispersant. To prepare a conductive paste. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 2]
Same as Example 2 except that a dispersant having an amine group having a specific dielectric constant of 8.5, an acid value of 60, and an amine value of 60 (a mixture of a compound having an acid group and a compound having an amine group) was used as the dispersant. To prepare a conductive paste. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 3]
As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.29 mg / m 2 , a surface abundance ratio of NiO of 49 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 4]
As the conductive powder, the conductive paste was used in the same manner as in Example 6 except that nickel powder having an H2O adsorption amount of 0.29 mg / m 2 , a surface abundance ratio of NiO of 49 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 5]
As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.71 mg / m 2 , a NiO surface presence ratio of 42 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
分散剤として比誘電率が３．０、酸価５３、アミン価４８のアミン基を有する分散剤（酸基を有する化合物とアミン基を有する化合物の混合物）を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例２］
分散剤として比誘電率が８．５、酸価６０、アミン価６０のアミン基を有する分散剤（酸基を有する化合物とアミン基を有する化合物の混合物）を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例３］
導電性粉末として、Ｈ２Ｏ吸着量０．２９ｍｇ／ｍ２、ＮｉＯの表面存在割合４９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例４］
導電性粉末として、Ｈ２Ｏ吸着量０．２９ｍｇ／ｍ２、ＮｉＯの表面存在割合４９モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例６と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。
［比較例５］
導電性粉末として、Ｈ２Ｏ吸着量０．７１ｍｇ／ｍ２、ＮｉＯの表面存在割合４２モル％、粒径０．２μｍのニッケル粉末を用いた以外は実施例２と同様にして、導電性ペーストを作製した。用いた各材料の種類や含有量などを表１に示す。また、得られた導電性ペーストに関して、実施例１と同様に粘度変化率、および光沢度を求めた。その結果を表２に示す。 [Comparative Example 1]
Same as Example 2 except that a dispersant having an amine group having a specific dielectric constant of 3.0, an acid value of 53, and an amine value of 48 (a mixture of a compound having an acid group and a compound having an amine group) was used as the dispersant. To prepare a conductive paste. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 2]
Same as Example 2 except that a dispersant having an amine group having a specific dielectric constant of 8.5, an acid value of 60, and an amine value of 60 (a mixture of a compound having an acid group and a compound having an amine group) was used as the dispersant. To prepare a conductive paste. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 3]
As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.29 mg / m 2 , a surface abundance ratio of NiO of 49 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 4]
As the conductive powder, the conductive paste was used in the same manner as in Example 6 except that nickel powder having an H2O adsorption amount of 0.29 mg / m 2 , a surface abundance ratio of NiO of 49 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
[Comparative Example 5]
As the conductive powder, the conductive paste was used in the same manner as in Example 2 except that nickel powder having an H2O adsorption amount of 0.71 mg / m 2 , a NiO surface presence ratio of 42 mol%, and a particle size of 0.2 μm was used. Was produced. Table 1 shows the types and contents of each material used. Further, with respect to the obtained conductive paste, the viscosity change rate and the glossiness were determined in the same manner as in Example 1. The results are shown in Table 2.
（評価結果）
比誘電率１０以上の分散剤を含有した実施例の導電性ペーストは、比誘電率が１０未満である比較例の導電性ペーストに比べ、乾燥膜表面の光沢度が高く、平滑性に優れていることがわかる。また、粘度変化率も小さいことから、分散剤の吸着による分散性の向上が長期間にわたって維持されていることがわかる。 (Evaluation results)
The conductive paste of the example containing the dispersant having a relative permittivity of 10 or more has a higher glossiness on the surface of the dried film and is excellent in smoothness as compared with the conductive paste of the comparative example having a relative permittivity of less than 10. You can see that there is. In addition, since the rate of change in viscosity is small, it can be seen that the improvement in dispersibility due to the adsorption of the dispersant is maintained for a long period of time.
比誘電率１０以上の分散剤を含有した実施例の導電性ペーストは、比誘電率が１０未満である比較例の導電性ペーストに比べ、乾燥膜表面の光沢度が高く、平滑性に優れていることがわかる。また、粘度変化率も小さいことから、分散剤の吸着による分散性の向上が長期間にわたって維持されていることがわかる。 (Evaluation results)
The conductive paste of the example containing the dispersant having a relative permittivity of 10 or more has a higher glossiness on the surface of the dried film and is excellent in smoothness as compared with the conductive paste of the comparative example having a relative permittivity of less than 10. You can see that there is. In addition, since the rate of change in viscosity is small, it can be seen that the improvement in dispersibility due to the adsorption of the dispersant is maintained for a long period of time.
アミン価（アミン基）を有さず、酸価（酸基）のみ有する分散剤を使用した実施例４と実施例５は、他の実施例に比べると光沢度が若干低いが、比較例に比べると、十分に高い光沢度と小さな粘度変化率を示している。よって、乾燥膜表面全体の平滑性を向上させるという観点から、アミン価が１００以上の分散剤を用いる方が好ましいことが分かる。
Examples 4 and 5 using a dispersant having no amine value (amine group) and only an acid value (acid group) have a slightly lower glossiness than the other examples, but are comparative examples. By comparison, it shows a sufficiently high glossiness and a small rate of change in viscosity. Therefore, from the viewpoint of improving the smoothness of the entire surface of the dried film, it is preferable to use a dispersant having an amine value of 100 or more.
一方、比誘電率１０未満の分散剤を含有した比較例１、２の導電性ペーストは、乾燥膜表面の光沢度が非常に低く、平滑性に劣ることが分かる。これは、分散剤が所定の特性を満たしていないため、粒子表面への濡れ性が悪く、分散剤が粒子表面へ十分に吸着されないため、粒子の解砕や再凝集の抑制が十分にできないため、導電性ペーストの分散性が悪く、材料の偏りが発生し、乾燥膜表面の平滑性が劣っていると考えられる。また、分散剤の吸着性が劣るため、分散安定性が悪く、各材料の凝集などが時間と共に増えてしまい、そのために粘度変化率が時間と共に大きくなっていると考えられる。
On the other hand, it can be seen that the conductive pastes of Comparative Examples 1 and 2 containing a dispersant having a relative permittivity of less than 10 have a very low glossiness on the surface of the dried film and are inferior in smoothness. This is because the dispersant does not satisfy the predetermined characteristics, so that the wettability to the particle surface is poor, and the dispersant is not sufficiently adsorbed to the particle surface, so that the crushing and reaggregation of the particles cannot be sufficiently suppressed. It is considered that the dispersibility of the conductive paste is poor, the material is biased, and the smoothness of the dry film surface is inferior. Further, it is considered that the dispersant has poor adsorptivity, so that the dispersion stability is poor and the aggregation of each material increases with time, and therefore the viscosity change rate increases with time.
また、単位面積当たりのＨ２Ｏ吸着量が発明の範囲外である比較例３～５は、平滑性はある程度低いものの、いずれも導電性粉末の表面状態が適切でないため、ペースト化した際の分散安定性が悪く、導電性粉末同士の凝集などが時間とともに増加し、粘度変化率も時間と共に大きくなっていると考えられる。
Further, in Comparative Examples 3 to 5 in which the amount of H 2 O adsorbed per unit area is outside the scope of the invention, although the smoothness is low to some extent, the surface condition of the conductive powder is not appropriate in any of them, so that when they are made into a paste, they are made into a paste. It is considered that the dispersion stability is poor, the aggregation of the conductive powders increases with time, and the viscosity change rate also increases with time.
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、特願２０２０－１９６２５６、および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。
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. Further, the requirements described in the above-described embodiments and the like can be appropriately combined. In addition, to the extent permitted by law, the disclosure of Japanese Patent Application No. 2020-196256 and all the documents cited in the above-described embodiments will be incorporated as part of the description of the main text.
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 Multilayerceramic capacitor 10 Ceramic laminate 11 Internal electrode layer 12 Dielectric layer 20 External electrode 21 External electrode layer 22 Plating layer
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
Claims (11)
- 導電性粉末、セラミック粉末、バインダー樹脂、有機溶剤および分散剤を含有する導電性ペーストにおいて、
前記導電性粉末は、相対圧Ｐ／Ｐ０＝０．５における単位面積当たりのＨ２Ｏ吸着量が０．３０ｍｇ／ｍ２以上０．７０ｍｇ／ｍ２以下であり、
前記分散剤が、１０以上の比誘電率を有し、かつ、（１）酸基を有する化合物、及び、（２）アミン基を有する化合物、からなる群より選ばれる少なくとも１種類の化合物を含有する、
導電性ペースト。 In conductive pastes containing conductive powders, ceramic powders, binder resins, organic solvents and dispersants.
The conductive powder has an H 2 O adsorption amount per unit area of 0.30 mg / m 2 or more and 0.70 mg / m 2 or less at a relative pressure of P / P 0 = 0.5.
The dispersant contains at least one compound selected from the group consisting of a compound having a relative permittivity of 10 or more and having (1) an acid group and (2) a compound having an amine group. do,
Conductive paste. - 前記（１）酸基を有する化合物が、カルボキシル基およびリン酸基の少なくとも一方を含む化合物である、請求項１に記載の導電性ペースト。 The conductive paste according to claim 1, wherein the compound having the (1) acid group is a compound containing at least one of a carboxyl group and a phosphoric acid group.
- 前記バインダー樹脂が、セルロース系樹脂及びブチラール系樹脂からなる群より選ばれる１種以上を含有する、請求項１又は請求項２に記載の導電性ペースト。 The conductive paste according to claim 1 or 2, wherein the binder resin contains at least one selected from the group consisting of a cellulosic resin and a butyral resin.
- 前記バインダー樹脂の含有量が、導電性ペースト１００質量％に対して０．５質量％以上１０質量％以下である、請求項１～３のいずれか一項に記載の導電性ペースト。 The conductive paste according to any one of claims 1 to 3, wherein the content of the binder resin is 0.5% by mass or more and 10% by mass or less with respect to 100% by mass of the conductive paste.
- 前記導電性粉末が、Ｎｉ、Ｃｕ、Ａｇ、Ｐｄ、Ａｕ、Ｐｔ粉末、及びこれらの合金粉末からなる群より選ばれる１種以上の金属粉末を含有する、請求項１～４のいずれか一項に記載の導電性ペースト。 One of claims 1 to 4, wherein the conductive powder contains one or more metal powders selected from the group consisting of Ni, Cu, Ag, Pd, Au, Pt powder, and alloy powders thereof. The conductive paste described in.
- 前記導電性粉末が、ニッケル粉末である、請求項１～５のいずれか一項に記載の導電性ペースト。 The conductive paste according to any one of claims 1 to 5, wherein the conductive powder is nickel powder.
- 前記ニッケル粉末の表面組成において、ＮｉＯが２０モル％以上９０モル％以下である、請求項６に記載の導電性ペースト。 The conductive paste according to claim 6, wherein NiO is 20 mol% or more and 90 mol% or less in the surface composition of the nickel powder.
- 前記導電性粉末の含有量が、導電性ペースト１００質量％に対して３０質量％以上７０質量％以下である、請求項１～７のいずれか一項に記載の導電性ペースト。 The conductive paste according to any one of claims 1 to 7, wherein the content of the conductive powder is 30% by mass or more and 70% by mass or less with respect to 100% by mass of the conductive paste.
- 前記セラミック粉末が、チタン酸バリウム系およびジルコン酸ストロンチウム系からなる群より選ばれる少なくとも１種である、請求項１～８のいずれか一項に記載の導電性ペースト。 The conductive paste according to any one of claims 1 to 8, wherein the ceramic powder is at least one selected from the group consisting of barium titanate and strontium zirconate.
- 製造後２５℃で３０日間静置し、ブルックフィールド粘度計にて２５℃、１０ｒｐｍの条件にて測定した際の導電性ペーストの粘度の変化率が、製造８時間後の導電性ペーストの粘度に対して、±１０％以下である、請求項１～９のいずれか一項に記載の導電性ペースト。 The rate of change in the viscosity of the conductive paste when it was allowed to stand at 25 ° C. for 30 days after production and measured with a Brookfield viscometer at 25 ° C. and 10 rpm was the viscosity of the conductive paste 8 hours after production. The conductive paste according to any one of claims 1 to 9, which is ± 10% or less.
- 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、請求項１～１０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、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, and has
The internal electrode layer is a multilayer ceramic capacitor formed by using the conductive paste according to any one of claims 1 to 10.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020237009229A KR20230110244A (en) | 2020-11-26 | 2021-11-26 | Conductive paste and multilayer ceramic capacitors |
| CN202180078301.4A CN116569293A (en) | 2020-11-26 | 2021-11-26 | Conductive paste and multilayer ceramic capacitor |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2020-196256 | 2020-11-26 | ||
| JP2020196256A JP2022084400A (en) | 2020-11-26 | 2020-11-26 | Conductive paste and laminated ceramic capacitor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2022114121A1 true WO2022114121A1 (en) | 2022-06-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2021/043372 WO2022114121A1 (en) | 2020-11-26 | 2021-11-26 | Conductive paste and multilayer ceramic capacitor |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP2022084400A (en) |
| KR (1) | KR20230110244A (en) |
| CN (1) | CN116569293A (en) |
| TW (1) | TW202234427A (en) |
| WO (1) | WO2022114121A1 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000299016A (en) * | 1999-04-15 | 2000-10-24 | Koichi Niihara | Deformed conductive elastomer and its manufacture |
| JP2001214201A (en) * | 1999-11-22 | 2001-08-07 | Mitsui Mining & Smelting Co Ltd | Nickel powder, producing method therefor and paste for forming electrode for electronic part |
| JP2016076627A (en) * | 2014-10-07 | 2016-05-12 | 住友金属鉱山株式会社 | Internal electrode material for multilayer ceramic capacitor |
| WO2020144746A1 (en) * | 2019-01-08 | 2020-07-16 | 住友金属鉱山株式会社 | Nickel paste for multilayer ceramic capacitors |
| WO2020166361A1 (en) * | 2019-02-12 | 2020-08-20 | 住友金属鉱山株式会社 | Electroconductive paste, electronic component, and laminated ceramic capacitor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4801958B2 (en) | 2005-09-29 | 2011-10-26 | 東海ゴム工業株式会社 | Conductive paste |
-
2020
- 2020-11-26 JP JP2020196256A patent/JP2022084400A/en active Pending
-
2021
- 2021-11-26 CN CN202180078301.4A patent/CN116569293A/en active Pending
- 2021-11-26 TW TW110144243A patent/TW202234427A/en unknown
- 2021-11-26 KR KR1020237009229A patent/KR20230110244A/en unknown
- 2021-11-26 WO PCT/JP2021/043372 patent/WO2022114121A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000299016A (en) * | 1999-04-15 | 2000-10-24 | Koichi Niihara | Deformed conductive elastomer and its manufacture |
| JP2001214201A (en) * | 1999-11-22 | 2001-08-07 | Mitsui Mining & Smelting Co Ltd | Nickel powder, producing method therefor and paste for forming electrode for electronic part |
| JP2016076627A (en) * | 2014-10-07 | 2016-05-12 | 住友金属鉱山株式会社 | Internal electrode material for multilayer ceramic capacitor |
| WO2020144746A1 (en) * | 2019-01-08 | 2020-07-16 | 住友金属鉱山株式会社 | Nickel paste for multilayer ceramic capacitors |
| WO2020166361A1 (en) * | 2019-02-12 | 2020-08-20 | 住友金属鉱山株式会社 | Electroconductive paste, electronic component, and laminated ceramic capacitor |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20230110244A (en) | 2023-07-21 |
| CN116569293A (en) | 2023-08-08 |
| JP2022084400A (en) | 2022-06-07 |
| TW202234427A (en) | 2022-09-01 |
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