JP2017119906A - Nickel fine particle-containing composition and method for producing the same, internal electrode, and multi-layered ceramic capacitor - Google Patents
Nickel fine particle-containing composition and method for producing the same, internal electrode, and multi-layered ceramic capacitor Download PDFInfo
- Publication number
- JP2017119906A JP2017119906A JP2016039883A JP2016039883A JP2017119906A JP 2017119906 A JP2017119906 A JP 2017119906A JP 2016039883 A JP2016039883 A JP 2016039883A JP 2016039883 A JP2016039883 A JP 2016039883A JP 2017119906 A JP2017119906 A JP 2017119906A
- Authority
- JP
- Japan
- Prior art keywords
- nickel fine
- fine particles
- nickel
- containing composition
- particle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title claims abstract description 1112
- 229910052759 nickel Inorganic materials 0.000 title claims abstract description 562
- 239000010419 fine particle Substances 0.000 title claims abstract description 481
- 239000000203 mixture Substances 0.000 title claims abstract description 126
- 239000003985 ceramic capacitor Substances 0.000 title claims abstract description 16
- 238000004519 manufacturing process Methods 0.000 title claims description 25
- 239000002245 particle Substances 0.000 claims abstract description 232
- 238000009826 distribution Methods 0.000 claims abstract description 45
- 239000002002 slurry Substances 0.000 claims description 40
- 230000009467 reduction Effects 0.000 claims description 30
- 239000002904 solvent Substances 0.000 claims description 27
- 239000000919 ceramic Substances 0.000 claims description 25
- 238000002156 mixing Methods 0.000 claims description 23
- 238000005406 washing Methods 0.000 claims description 21
- 239000011148 porous material Substances 0.000 claims description 12
- 238000001914 filtration Methods 0.000 claims description 10
- 239000000758 substrate Substances 0.000 claims description 7
- 230000001186 cumulative effect Effects 0.000 claims description 5
- 238000005245 sintering Methods 0.000 abstract description 20
- 150000001875 compounds Chemical class 0.000 abstract description 4
- 230000000977 initiatory effect Effects 0.000 abstract 1
- 229910052755 nonmetal Inorganic materials 0.000 abstract 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 56
- 229910052802 copper Inorganic materials 0.000 description 56
- 239000010949 copper Substances 0.000 description 56
- 238000010438 heat treatment Methods 0.000 description 52
- 238000000034 method Methods 0.000 description 51
- 125000001931 aliphatic group Chemical group 0.000 description 46
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 39
- 239000000243 solution Substances 0.000 description 39
- 238000006722 reduction reaction Methods 0.000 description 34
- -1 Nickel salt Chemical class 0.000 description 32
- 239000003960 organic solvent Substances 0.000 description 29
- 230000015572 biosynthetic process Effects 0.000 description 25
- 229910052751 metal Inorganic materials 0.000 description 23
- 150000001412 amines Chemical class 0.000 description 22
- 238000006243 chemical reaction Methods 0.000 description 22
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 21
- 238000003786 synthesis reaction Methods 0.000 description 20
- 230000000694 effects Effects 0.000 description 19
- 239000002184 metal Substances 0.000 description 19
- 229910001453 nickel ion Inorganic materials 0.000 description 18
- 239000000463 material Substances 0.000 description 15
- VEQPNABPJHWNSG-UHFFFAOYSA-N Nickel(2+) Chemical compound [Ni+2] VEQPNABPJHWNSG-UHFFFAOYSA-N 0.000 description 14
- 125000004432 carbon atom Chemical group C* 0.000 description 14
- 150000002815 nickel Chemical class 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 12
- 238000005755 formation reaction Methods 0.000 description 12
- QGLWBTPVKHMVHM-KTKRTIGZSA-N (z)-octadec-9-en-1-amine Chemical compound CCCCCCCC\C=C/CCCCCCCCN QGLWBTPVKHMVHM-KTKRTIGZSA-N 0.000 description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 11
- 238000002360 preparation method Methods 0.000 description 11
- 230000008569 process Effects 0.000 description 11
- 238000004220 aggregation Methods 0.000 description 10
- 230000002776 aggregation Effects 0.000 description 10
- 230000009918 complex formation Effects 0.000 description 10
- 230000007423 decrease Effects 0.000 description 10
- 150000003839 salts Chemical class 0.000 description 10
- 238000009835 boiling Methods 0.000 description 9
- 230000000536 complexating effect Effects 0.000 description 9
- 230000007547 defect Effects 0.000 description 9
- 239000007788 liquid Substances 0.000 description 9
- 239000006228 supernatant Substances 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 230000032798 delamination Effects 0.000 description 8
- 239000003446 ligand Substances 0.000 description 8
- 239000011163 secondary particle Substances 0.000 description 8
- 239000003981 vehicle Substances 0.000 description 8
- 239000007772 electrode material Substances 0.000 description 7
- 229910021645 metal ion Inorganic materials 0.000 description 7
- 238000011946 reduction process Methods 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 6
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 6
- 230000008859 change Effects 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 6
- 230000008602 contraction Effects 0.000 description 6
- 238000000354 decomposition reaction Methods 0.000 description 6
- 238000010494 dissociation reaction Methods 0.000 description 6
- 230000005593 dissociations Effects 0.000 description 6
- 239000010408 film Substances 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 238000007639 printing Methods 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 5
- 239000006185 dispersion Substances 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- 150000002739 metals Chemical class 0.000 description 5
- 239000011259 mixed solution Substances 0.000 description 5
- HZPNKQREYVVATQ-UHFFFAOYSA-L nickel(2+);diformate Chemical compound [Ni+2].[O-]C=O.[O-]C=O HZPNKQREYVVATQ-UHFFFAOYSA-L 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 229910000510 noble metal Inorganic materials 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 229910052709 silver Inorganic materials 0.000 description 5
- 239000004332 silver Substances 0.000 description 5
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 description 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- PLZVEHJLHYMBBY-UHFFFAOYSA-N Tetradecylamine Chemical compound CCCCCCCCCCCCCCN PLZVEHJLHYMBBY-UHFFFAOYSA-N 0.000 description 4
- 150000008064 anhydrides Chemical class 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- HFDWIMBEIXDNQS-UHFFFAOYSA-L copper;diformate Chemical compound [Cu+2].[O-]C=O.[O-]C=O HFDWIMBEIXDNQS-UHFFFAOYSA-L 0.000 description 4
- 239000011162 core material Substances 0.000 description 4
- JRBPAEWTRLWTQC-UHFFFAOYSA-N dodecylamine Chemical compound CCCCCCCCCCCCN JRBPAEWTRLWTQC-UHFFFAOYSA-N 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- 230000005389 magnetism Effects 0.000 description 4
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 239000011164 primary particle Substances 0.000 description 4
- 229920006395 saturated elastomer Polymers 0.000 description 4
- 239000004034 viscosity adjusting agent Substances 0.000 description 4
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- UWHCKJMYHZGTIT-UHFFFAOYSA-N Tetraethylene glycol, Natural products OCCOCCOCCOCCO UWHCKJMYHZGTIT-UHFFFAOYSA-N 0.000 description 3
- MQRWBMAEBQOWAF-UHFFFAOYSA-N acetic acid;nickel Chemical compound [Ni].CC(O)=O.CC(O)=O MQRWBMAEBQOWAF-UHFFFAOYSA-N 0.000 description 3
- 239000012298 atmosphere Substances 0.000 description 3
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 3
- 229910002113 barium titanate Inorganic materials 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 150000001879 copper Chemical class 0.000 description 3
- 229910001431 copper ion Inorganic materials 0.000 description 3
- LSIWWRSSSOYIMS-UHFFFAOYSA-L copper;diformate;tetrahydrate Chemical compound O.O.O.O.[Cu+2].[O-]C=O.[O-]C=O LSIWWRSSSOYIMS-UHFFFAOYSA-L 0.000 description 3
- 239000003989 dielectric material Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 230000005012 migration Effects 0.000 description 3
- 238000013508 migration Methods 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 229940078494 nickel acetate Drugs 0.000 description 3
- 229940078487 nickel acetate tetrahydrate Drugs 0.000 description 3
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 3
- BMGNSKKZFQMGDH-FDGPNNRMSA-L nickel(2+);(z)-4-oxopent-2-en-2-olate Chemical compound [Ni+2].C\C([O-])=C\C(C)=O.C\C([O-])=C\C(C)=O BMGNSKKZFQMGDH-FDGPNNRMSA-L 0.000 description 3
- OINIXPNQKAZCRL-UHFFFAOYSA-L nickel(2+);diacetate;tetrahydrate Chemical compound O.O.O.O.[Ni+2].CC([O-])=O.CC([O-])=O OINIXPNQKAZCRL-UHFFFAOYSA-L 0.000 description 3
- SMAMDWMLHWVJQM-UHFFFAOYSA-L nickel(2+);diformate;dihydrate Chemical compound O.O.[Ni+2].[O-]C=O.[O-]C=O SMAMDWMLHWVJQM-UHFFFAOYSA-L 0.000 description 3
- 229910000008 nickel(II) carbonate Inorganic materials 0.000 description 3
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 3
- ZULUUIKRFGGGTL-UHFFFAOYSA-L nickel(ii) carbonate Chemical compound [Ni+2].[O-]C([O-])=O ZULUUIKRFGGGTL-UHFFFAOYSA-L 0.000 description 3
- BFDHFSHZJLFAMC-UHFFFAOYSA-L nickel(ii) hydroxide Chemical compound [OH-].[OH-].[Ni+2] BFDHFSHZJLFAMC-UHFFFAOYSA-L 0.000 description 3
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 3
- 238000010899 nucleation Methods 0.000 description 3
- 230000006911 nucleation Effects 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 239000011593 sulfur Substances 0.000 description 3
- CXWXQJXEFPUFDZ-UHFFFAOYSA-N tetralin Chemical compound C1=CC=C2CCCCC2=C1 CXWXQJXEFPUFDZ-UHFFFAOYSA-N 0.000 description 3
- 230000000930 thermomechanical effect Effects 0.000 description 3
- NKJOXAZJBOMXID-UHFFFAOYSA-N 1,1'-Oxybisoctane Chemical compound CCCCCCCCOCCCCCCCC NKJOXAZJBOMXID-UHFFFAOYSA-N 0.000 description 2
- FJLUATLTXUNBOT-UHFFFAOYSA-N 1-Hexadecylamine Chemical compound CCCCCCCCCCCCCCCCN FJLUATLTXUNBOT-UHFFFAOYSA-N 0.000 description 2
- KBPLFHHGFOOTCA-UHFFFAOYSA-N 1-Octanol Chemical compound CCCCCCCCO KBPLFHHGFOOTCA-UHFFFAOYSA-N 0.000 description 2
- OAYXUHPQHDHDDZ-UHFFFAOYSA-N 2-(2-butoxyethoxy)ethanol Chemical compound CCCCOCCOCCO OAYXUHPQHDHDDZ-UHFFFAOYSA-N 0.000 description 2
- 239000004925 Acrylic resin Substances 0.000 description 2
- 229920000178 Acrylic resin Polymers 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 239000001856 Ethyl cellulose Substances 0.000 description 2
- 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 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- LRHPLDYGYMQRHN-UHFFFAOYSA-N N-Butanol Chemical compound CCCCO LRHPLDYGYMQRHN-UHFFFAOYSA-N 0.000 description 2
- 229910000990 Ni alloy Inorganic materials 0.000 description 2
- REYJJPSVUYRZGE-UHFFFAOYSA-N Octadecylamine Chemical compound CCCCCCCCCCCCCCCCCCN REYJJPSVUYRZGE-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000000862 absorption spectrum Methods 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- WUOACPNHFRMFPN-UHFFFAOYSA-N alpha-terpineol Chemical compound CC1=CCC(C(C)(C)O)CC1 WUOACPNHFRMFPN-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000008135 aqueous vehicle Substances 0.000 description 2
- 229910052788 barium Inorganic materials 0.000 description 2
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 238000005119 centrifugation Methods 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- DIOQZVSQGTUSAI-UHFFFAOYSA-N decane Chemical compound CCCCCCCCCC DIOQZVSQGTUSAI-UHFFFAOYSA-N 0.000 description 2
- SQIFACVGCPWBQZ-UHFFFAOYSA-N delta-terpineol Natural products CC(C)(O)C1CCC(=C)CC1 SQIFACVGCPWBQZ-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 150000004985 diamines Chemical class 0.000 description 2
- LAWOZCWGWDVVSG-UHFFFAOYSA-N dioctylamine Chemical compound CCCCCCCCNCCCCCCCC LAWOZCWGWDVVSG-UHFFFAOYSA-N 0.000 description 2
- WNAHIZMDSQCWRP-UHFFFAOYSA-N dodecane-1-thiol Chemical compound CCCCCCCCCCCCS WNAHIZMDSQCWRP-UHFFFAOYSA-N 0.000 description 2
- 229920001249 ethyl cellulose Polymers 0.000 description 2
- 235000019325 ethyl cellulose Nutrition 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000011049 filling Methods 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 238000007646 gravure printing Methods 0.000 description 2
- 239000012456 homogeneous solution Substances 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- 238000007885 magnetic separation Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000003607 modifier Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- XTAZYLNFDRKIHJ-UHFFFAOYSA-N n,n-dioctyloctan-1-amine Chemical compound CCCCCCCCN(CCCCCCCC)CCCCCCCC XTAZYLNFDRKIHJ-UHFFFAOYSA-N 0.000 description 2
- FJDUDHYHRVPMJZ-UHFFFAOYSA-N nonan-1-amine Chemical compound CCCCCCCCCN FJDUDHYHRVPMJZ-UHFFFAOYSA-N 0.000 description 2
- IOQPZZOEVPZRBK-UHFFFAOYSA-N octan-1-amine Chemical compound CCCCCCCCN IOQPZZOEVPZRBK-UHFFFAOYSA-N 0.000 description 2
- 239000013110 organic ligand Substances 0.000 description 2
- 239000005416 organic matter Substances 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 2
- 229920013639 polyalphaolefin Polymers 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 229930195734 saturated hydrocarbon Natural products 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000007650 screen-printing Methods 0.000 description 2
- 150000003335 secondary amines Chemical class 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- 229910052712 strontium Inorganic materials 0.000 description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- 238000001308 synthesis method Methods 0.000 description 2
- 229940116411 terpineol Drugs 0.000 description 2
- 150000003512 tertiary amines Chemical class 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 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
- 229930195735 unsaturated hydrocarbon Natural products 0.000 description 2
- 238000007740 vapor deposition Methods 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 229910000952 Be alloy Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910002367 SrTiO Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000003849 aromatic solvent Substances 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- 235000012255 calcium oxide Nutrition 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 239000012295 chemical reaction liquid Substances 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 150000004699 copper complex Chemical class 0.000 description 1
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- FDPIMTJIUBPUKL-UHFFFAOYSA-N dimethylacetone Natural products CCC(=O)CC FDPIMTJIUBPUKL-UHFFFAOYSA-N 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000000921 elemental analysis Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000002334 glycols Chemical class 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- JMWUYEFBFUCSAK-UHFFFAOYSA-L nickel(2+);octadecanoate Chemical compound [Ni+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O JMWUYEFBFUCSAK-UHFFFAOYSA-L 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- YJVFFLUZDVXJQI-UHFFFAOYSA-L palladium(ii) acetate Chemical compound [Pd+2].CC([O-])=O.CC([O-])=O YJVFFLUZDVXJQI-UHFFFAOYSA-L 0.000 description 1
- 239000000123 paper Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920001223 polyethylene glycol Polymers 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 230000002265 prevention 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
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052702 rhenium Inorganic materials 0.000 description 1
- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 229910001961 silver nitrate Inorganic materials 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 150000004685 tetrahydrates Chemical class 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
- 229910052845 zircon Inorganic materials 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical group [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
本発明は、例えば積層セラミックスコンデンサ（ＭＬＣＣ）の内部電極材料などの用途に利用できるニッケル微粒子含有組成物及びその製造方法、内部電極並びに積層セラミックスコンデンサに関する。 The present invention relates to a nickel fine particle-containing composition that can be used for applications such as an internal electrode material of a multilayer ceramic capacitor (MLCC), a manufacturing method thereof, an internal electrode, and a multilayer ceramic capacitor.
ＭＬＣＣは、セラミックス誘電体と内部電極とを交互に層状に重ねて圧着し、焼成して一体化させたものである。ＭＬＣＣの内部電極を形成する際には、内部電極材料である金属ニッケル微粒子（以下、単に「ニッケル微粒子」ともいう。）をペースト化したのち、これをセラミックス基板上に印刷する。次いで、乾燥、積層及び圧着した後、通常、酸素雰囲気下で約２５０〜４００℃に加熱して有機物を除去するための脱バインダー処理を行なう。このような加熱処理を行なうことによって、ニッケル微粒子は酸化され、それにより体積膨張が起きる。さらにその後、還元性雰囲気下で高温（例えばチタン酸バリウム系セラミックス誘電体では約１２００〜１４００℃）で焼結を行なう。この焼結により、一旦酸化されたニッケル微粒子が還元されるとともに、体積の収縮が生じる。 In MLCC, ceramic dielectrics and internal electrodes are alternately layered and pressure-bonded, and fired and integrated. When forming the internal electrode of MLCC, metallic nickel fine particles (hereinafter, also simply referred to as “nickel fine particles”), which is an internal electrode material, are formed into a paste and then printed on a ceramic substrate. Next, after drying, laminating and press-bonding, a binder removal treatment for removing organic substances is usually performed by heating to about 250 to 400 ° C. in an oxygen atmosphere. By performing such a heat treatment, the nickel fine particles are oxidized, thereby causing volume expansion. Thereafter, sintering is performed under a reducing atmosphere at a high temperature (for example, about 1200 to 1400 ° C. for a barium titanate ceramic dielectric). By this sintering, once oxidized nickel fine particles are reduced, volume shrinkage occurs.
このように、ＭＬＣＣの製造工程では、酸化反応や還元反応によってニッケル微粒子が膨張・収縮して体積変化が生じる。また、セラミックス誘電体も焼結により膨張・収縮し、体積変化が生じる。ところが、ニッケル微粒子とセラミックス誘電体とでは、焼結時における膨張・収縮による体積変化の挙動が異なる。すなわち、ニッケル微粒子の焼結開始温度（約５００℃）とセラミックス誘電体の焼結開始温度（約１０００℃）が大きく異なるために、デラミネーションやクラック等の欠陥を生じるおそれがある。 Thus, in the MLCC manufacturing process, the nickel fine particles expand and contract by an oxidation reaction or a reduction reaction, resulting in a volume change. The ceramic dielectric also expands and contracts due to sintering, resulting in a volume change. However, the behavior of volume change due to expansion / contraction during sintering differs between the nickel fine particles and the ceramic dielectric. That is, since the sintering start temperature (about 500 ° C.) of the nickel fine particles and the sintering start temperature (about 1000 ° C.) of the ceramic dielectric are greatly different, defects such as delamination and cracks may occur.
粒子径が１５０ｎｍ以下のニッケル微粒子は、ＭＬＣＣ製造時の焼結過程で誘電体層との熱収縮の差が従来の大粒子径のニッケル微粒子に比べてより拡大し、内部電極層と誘電体層とのデラミネーションや内部電極層の膜切れが多くなり、やはり製品としての歩留まりに問題がある。 Nickel fine particles with a particle size of 150 nm or less have a larger thermal shrinkage difference with the dielectric layer in the sintering process during MLCC production than the conventional nickel fine particles with a large particle size. As a result, there is a problem in yield as a product.
ニッケル微粒子の熱収縮を抑える方法として、ニッケル微粒子をタングステンなどの高融点金属によって合金化したり、ニッケル微粒子間の焼結による内部電極層の熱収縮防止のために金属酸化物の被膜を形成したりする方法が提案されている。しかし、これらの方法では、十分な焼結防止効果が得られていないばかりか、ニッケル以外の金属材料の混合により、誘電率の低下が免れない状況にある。 Methods for suppressing thermal shrinkage of nickel fine particles include alloying nickel fine particles with a refractory metal such as tungsten, or forming a metal oxide film to prevent thermal shrinkage of the internal electrode layer due to sintering between nickel fine particles. A method has been proposed. However, in these methods, not only a sufficient sintering prevention effect is not obtained, but also a reduction in dielectric constant is inevitable due to mixing of metal materials other than nickel.
このような状況において、例えば特許文献１では、平均粒子径が５０〜３００ｎｍであり、粒度分布の広いニッケル微粒子と、平均粒子径が１０〜５０ｎｍで貴金属または貴金属とニッケルの合金からなる微粒子と、を混合することを提案している。特許文献１では、内部電極層の厚みが薄層化した場合においても、焼成段階でのＮｉ粒子の粒成長を抑制し、粒子の球状化や内部電極の途切れなどを有効に防止し、静電容量の低下を効果的に抑制できる、とされている。 In such a situation, for example, in Patent Document 1, nickel fine particles having an average particle diameter of 50 to 300 nm and a wide particle size distribution, and fine particles made of a noble metal or an alloy of noble metal and nickel with an average particle diameter of 10 to 50 nm, Have proposed to mix. In Patent Document 1, even when the thickness of the internal electrode layer is reduced, the grain growth of the Ni particles in the firing stage is suppressed, and the spheroidization of the particles and the disconnection of the internal electrode are effectively prevented. It is said that a decrease in capacity can be effectively suppressed.
また、特許文献２では、ニッケルと貴金属の合金の平均粒子径が２００〜４００ｎｍの第１の導電粒子と、ニッケルと貴金属の合金の平均粒子径が４０〜８０ｎｍの第２の導電粒子とを混合することにより、特許文献１と同様な効果が得られることを提案している。 Moreover, in patent document 2, the 1st electroconductive particle whose average particle diameter of an alloy of nickel and a noble metal is 200-400 nm, and the 2nd electroconductive particle whose average particle diameter of an alloy of nickel and a noble metal is 40-80 nm are mixed. By doing so, it is proposed that the same effect as Patent Document 1 can be obtained.
上記特許文献１、２に記載の方法では、いずれも粒度分布の広い微粒子を用いることから、粗大粒子の存在は回避できず、製品の歩留まりの低下が避けられない。また、貴金属を使用することから、製造コストも高くなることが懸念される。さらに、平均粒子径が２００ｎｍを超える微粒子を用いるため、内部電極層の薄膜化にも限界があると考えられる。 In each of the methods described in Patent Documents 1 and 2, since fine particles having a wide particle size distribution are used, the presence of coarse particles cannot be avoided, and a reduction in product yield cannot be avoided. In addition, since noble metals are used, there is a concern that the manufacturing cost will increase. Furthermore, since fine particles having an average particle diameter exceeding 200 nm are used, it is considered that there is a limit to reducing the thickness of the internal electrode layer.
本発明者らは、先に、走査型電子顕微鏡観察による平均粒子径が６０〜１５０ｎｍの範囲内であり、かつ、粒子径の変動係数が０．２以下である第１のニッケル微粒子と、走査型電子顕微鏡観察による平均粒子径が１０〜６０ｎｍの範囲内であり、粒子径の変動係数が０．２以下であり、かつ、５％熱収縮率温度が、前記第１のニッケル微粒子の５％熱収縮率温度より５０℃以上高い第２のニッケル微粒子を含有するニッケル微粒子含有組成物を提案した（例えば、特許文献３）。特許文献３のニッケル微粒子含有組成物は、焼結時の熱収縮が効果的に抑制されており、例えばＭＬＣＣの内部電極の材料などの用途に好適に用いることができるものである。しかし、特許文献３の技術では、第２のニッケル微粒子の熱収縮温度を高くする目的で、第２のニッケル微粒子を硫黄含有化合物、硫黄元素、リン含有有機化合物等で処理することが必要であった。しかし、これらの非金属化合物は、電極性能への影響を考慮すると、なるべく含有しないことがよいと考えられる。また、第２のニッケル微粒子を表面処理することによって、その表面状態が第１のニッケル微粒子とは異なるものとなり、分散挙動が変わる点においても改善の余地が残されていた。 The inventors previously scanned the first nickel fine particles having an average particle diameter in the range of 60 to 150 nm and a coefficient of variation of the particle diameter of 0.2 or less by scanning electron microscope observation, and scanning. The average particle diameter is 10 to 60 nm as observed with a scanning electron microscope, the coefficient of variation of the particle diameter is 0.2 or less, and the 5% heat shrinkage temperature is 5% of the first nickel fine particles. The nickel fine particle containing composition containing the 2nd nickel fine particle higher 50 degreeC or more than heat contraction rate temperature was proposed (for example, patent document 3). The nickel fine particle-containing composition of Patent Document 3 is effectively suppressed from thermal shrinkage during sintering, and can be suitably used for applications such as MLCC internal electrode materials. However, in the technique of Patent Document 3, it is necessary to treat the second nickel fine particles with a sulfur-containing compound, sulfur element, phosphorus-containing organic compound or the like for the purpose of increasing the heat shrink temperature of the second nickel fine particles. It was. However, it is considered that these non-metallic compounds should not be contained as much as possible considering the influence on the electrode performance. Further, by subjecting the second nickel fine particles to surface treatment, the surface state thereof is different from that of the first nickel fine particles, and there is still room for improvement in that the dispersion behavior changes.
本発明の目的は、例えばＭＬＣＣの内部電極層等の用途に有用で、非金属元素化合物による処理を行わなくても、焼結時の熱収縮が抑制されており、焼結開始温度の高いニッケル微粒子含有組成物を提供することである。 The object of the present invention is useful for applications such as MLCC internal electrode layers, etc., and heat shrinkage during sintering is suppressed even without treatment with a non-metallic element compound, and nickel having a high sintering start temperature. It is to provide a fine particle-containing composition.
本発明者らは、鋭意研究を重ねた結果、平均粒子径が異なり、かつ、特定の粒度分布を有する少なくとも２種類のニッケル微粒子を組み合わせるとともに、大粒径のニッケル微粒子に対して、小粒径のニッケル微粒子を均等に分布させることによって、内部電極層の収縮や膜切れを効果的に抑えることが可能であるとの知見を得て本発明を完成するに至った。 As a result of intensive research, the inventors combined at least two kinds of nickel fine particles having different average particle diameters and a specific particle size distribution, and compared to large-sized nickel fine particles with a small particle diameter. The present inventors completed the present invention by obtaining the knowledge that it is possible to effectively suppress shrinkage and film breakage of the internal electrode layer by uniformly distributing the nickel fine particles.
すなわち、本発明のニッケル微粒子含有組成物は、次の成分Ａ及びＢ；
Ａ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０Ａが４０〜２００ｎｍの範囲内である第１のニッケル微粒子、
及び、
Ｂ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０Ｂが５ｎｍ以上４０ｎｍ未満の範囲内である第２のニッケル微粒子、
を含有する。
また、本発明のニッケル微粒子含有組成物は、走査型電子顕微鏡観察によって任意の３００個の前記第１のニッケル微粒子を観察したときに、表面に少なくとも１個以上の前記第２のニッケル微粒子が接触している前記第１のニッケル微粒子の存在確率が３０％以上である。
That is, the nickel fine particle-containing composition of the present invention comprises the following components A and B;
A) a first nickel fine particle having an average particle diameter D50 A in the range of 40 to 200 nm in a number-based particle size distribution by scanning electron microscope observation;
as well as,
B) Second nickel fine particles whose average particle diameter D50 B is in the range of 5 nm or more and less than 40 nm in the number-based particle size distribution by scanning electron microscope observation,
Containing.
Further, in the nickel fine particle-containing composition of the present invention, when any 300 of the first nickel fine particles are observed by scanning electron microscope observation, at least one of the second nickel fine particles contacts the surface. The existence probability of the first nickel fine particles is 30% or more.
本発明のニッケル微粒子含有組成物は、走査型電子顕微鏡観察による個数基準の粒度分布において、第１のニッケル微粒子の小粒径側からの積算粒度分布が１％となる値をＤ１Ａ、第２のニッケル微粒子の小粒径側からの積算粒度分布が９９％となる値をＤ９９Ｂとしたとき、以下の関係；
Ｄ５０Ａ＞Ｄ５０Ｂ×４ … （１）
かつ
Ｄ１Ａ−Ｄ９９Ｂ ＞ （Ｄ５０Ａ−Ｄ５０Ｂ）／４ … （２）
を満たすものであってもよい。
In the nickel fine particle-containing composition of the present invention, in the particle size distribution based on the number based on the observation with a scanning electron microscope, the value at which the cumulative particle size distribution from the small particle size side of the first nickel fine particles is 1% is D1 A , When the value at which the cumulative particle size distribution from the small particle size side of the nickel fine particles is 99% is D99 B , the following relationship:
D50 A > D50 B × 4 (1)
And D1 A -D99 B> (D50 A -D50 B) / 4 ... (2)
It may satisfy.
本発明のニッケル微粒子含有組成物は、前記成分Ａと前記成分Ｂの合計量に対する、前記成分Ａの含有量が７５〜９９質量％の範囲内であってもよく、前記成分Ｂの含有量が１〜２５質量％の範囲内であってもよい。 In the nickel fine particle-containing composition of the present invention, the content of the component A relative to the total amount of the component A and the component B may be in the range of 75 to 99% by mass, and the content of the component B is It may be in the range of 1 to 25% by mass.
本発明のニッケル微粒子含有組成物は、前記第１のニッケル微粒子と前記第２のニッケル微粒子は、ともに粒子径の変動係数が０．２５以下であってもよい。 In the nickel fine particle-containing composition of the present invention, both the first nickel fine particles and the second nickel fine particles may have a coefficient of variation in particle diameter of 0.25 or less.
本発明のニッケル微粒子含有組成物は、さらに、溶媒を含有するスラリーの形態であってもよい。 The nickel fine particle-containing composition of the present invention may further be in the form of a slurry containing a solvent.
本発明の積層セラミックコンデンサ用の内部電極は、上記いずれかのニッケル微粒子含有組成物をペースト化し、セラミック基板上に印刷したものである。 The internal electrode for a multilayer ceramic capacitor of the present invention is obtained by pasting any one of the above nickel fine particle-containing compositions and printing it on a ceramic substrate.
本発明の積層セラミックコンデンサは、上記内部電極とセラミック誘電体とを交互に層状に重ねて圧着し、焼成して一体化させたものである。 The multilayer ceramic capacitor of the present invention is one in which the internal electrodes and the ceramic dielectric are alternately stacked in layers and pressed and fired and integrated.
本発明のニッケル微粒子含有組成物の製造方法は、下記の工程ａ〜ｄ；
ａ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０が４０〜２００ｎｍの範囲内である第１のニッケル微粒子のスラリーを得る工程、
ｂ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０が５ｎｍ以上４０ｎｍ未満の範囲内である第２のニッケル微粒子のスラリーを得る工程、
ｃ）前記第２のニッケル微粒子を溶剤で洗浄する工程、
及び
ｄ）前記第１のニッケル微粒子と前記第２のニッケル微粒子とを混合する工程、
を含むものである。
また、本発明のニッケル微粒子含有組成物の製造方法において、
前記工程ｃは、前記第２のニッケル微粒子の平均粒子径Ｄ５０に対して１０％以上小さな平均孔径を有するフィルタを用い、前記第２のニッケル微粒子を前記溶剤とともに前記フィルタでろ過することにより行われ、
かつ、
前記工程ｄは、前記工程ｃと同時に、又は前記工程ｃの後で引き続き、前記フィルタで前記第１のニッケル微粒子をろ過することによって行われる。
The method for producing the nickel fine particle-containing composition of the present invention includes the following steps a to d;
a) obtaining a slurry of first nickel fine particles having an average particle diameter D50 in the range of 40 to 200 nm in a number-based particle size distribution by scanning electron microscope observation;
b) a step of obtaining a slurry of second nickel fine particles having an average particle diameter D50 in the range of 5 nm or more and less than 40 nm in a number-based particle size distribution by scanning electron microscope observation;
c) washing the second nickel fine particles with a solvent;
And d) mixing the first nickel fine particles and the second nickel fine particles,
Is included.
Further, in the method for producing the nickel fine particle-containing composition of the present invention,
The step c is performed by using a filter having an average pore size that is 10% or more smaller than the average particle size D50 of the second nickel fine particles, and filtering the second nickel fine particles together with the solvent. ,
And,
The step d is performed by filtering the first nickel fine particles with the filter simultaneously with the step c or after the step c.
本発明のニッケル微粒子含有組成物の製造方法は、前記フィルタが、セラミックスフィルタであってもよい。 In the method for producing a nickel fine particle-containing composition of the present invention, the filter may be a ceramic filter.
本発明のニッケル微粒子含有組成物の製造方法は、前記第１のニッケル微粒子及び前記第２のニッケル微粒子が、湿式加熱還元によって得られたものであってもよい。この場合、前記湿式加熱還元が、マイクロ波照射によるものであってもよい。 In the method for producing a nickel fine particle-containing composition of the present invention, the first nickel fine particles and the second nickel fine particles may be obtained by wet heat reduction. In this case, the wet heat reduction may be by microwave irradiation.
本発明のニッケル微粒子含有組成物の製造方法は、前記工程ａにおいて得られる第１のニッケル微粒子が、前記工程ｂで得られる第２のニッケル微粒子を種粒子として用いて得られたものであってもよい。 In the method for producing a nickel fine particle-containing composition of the present invention, the first nickel fine particles obtained in the step a are obtained using the second nickel fine particles obtained in the step b as seed particles. Also good.
本発明のニッケル微粒子含有組成物によれば、平均粒子径が異なる２種類のニッケル微粒子を混合しているため、粒度分布のピークを少なくとも２つ持っており、しかも大粒径の第１のニッケル微粒子に対する小粒径の第２のニッケル微粒子の存在状態が均等であるため、組成物の密度が、単一ピークの粒子径分布を持つ同体積のニッケル微粒子に比べて高く、高密度な微粒子混合状態を作り出している。このようなニッケル微粒子含有組成物は、例えば、ＭＬＣＣの内部電極の材料などの用途に好適に用いることができる。また、本発明のニッケル微粒子含有組成物は、例えばＭＬＣＣ製造時の焼結過程で、第１のニッケル微粒子の周囲に均等に分布した第２のニッケル微粒子が速やかに溶融し、第１のニッケル微粒子どうしの隙間を埋めることによって熱収縮が生じにくい。従って、本発明のニッケル微粒子含有組成物を用いることによって、積層セラミックコンデンサの製造過程で、焼結時のデラミネーションやクラック等の欠陥の発生を防ぐことができる。また、本発明の内部電極を用いたＭＬＣＣは、従来のニッケル粒子を使用した電極の膜厚をより薄くすることが可能であることから、小型高容量を実現でき、長寿命性、高信頼性に優れる。そのため、携帯電話、携帯端末、パーソナルコンピュータ、ドローンやスマートウオッチ等の電気・電子製品、オーディオ、通信、コンピュータ制御等の自動車用部品に好適に用いることができる。 According to the nickel fine particle-containing composition of the present invention, since two types of nickel fine particles having different average particle diameters are mixed, the composition has at least two peaks in the particle size distribution and the first nickel having a large particle diameter. Since the second nickel fine particles having a small particle size with respect to the fine particles are uniform, the density of the composition is higher than that of the same volume nickel fine particles having a single-peak particle size distribution, and high-density fine particle mixing Creating a state. Such a nickel fine particle containing composition can be used suitably for uses, such as the material of the internal electrode of MLCC, for example. In the nickel fine particle-containing composition of the present invention, for example, in the sintering process at the time of MLCC production, the second nickel fine particles uniformly distributed around the first nickel fine particles are rapidly melted. Thermal contraction is less likely to occur by filling the gaps between them. Therefore, by using the nickel fine particle-containing composition of the present invention, it is possible to prevent the occurrence of defects such as delamination and cracks during sintering during the production process of the multilayer ceramic capacitor. In addition, the MLCC using the internal electrode of the present invention can reduce the film thickness of the electrode using the conventional nickel particles, thereby realizing a small size and a high capacity, and a long life and high reliability. Excellent. Therefore, it can be suitably used for automobile parts such as mobile phones, mobile terminals, personal computers, electric / electronic products such as drones and smart watches, audio, communication, computer control and the like.
［ニッケル微粒子含有組成物］
以下、適宜図面を参照しながら本発明の実施の形態について説明する。図１は、本発明の一実施の形態に係るニッケル微粒子含有組成物の構成を示す模式図である。本実施の形態のニッケル微粒子含有組成物１００は、成分Ａとして、平均粒子径Ｄ５０Ａが４０〜２００ｎｍの範囲内である第１のニッケル微粒子１０、及び、成分Ｂとして、平均粒子径Ｄ５０Ｂが５ｎｍ以上４０ｎｍ未満の範囲内である第２のニッケル微粒子２０を含有する。ここで、第１のニッケル微粒子１０と第２のニッケル微粒子２０の平均粒子径（メディアン径）Ｄ５０は、いずれもＳＥＭ（走査型電子顕微鏡）により試料の写真を撮影して、その中から無作為に３００個を抽出してそれぞれの粒子について面積を求め、真球に換算したときの粒子径から、個数基準にて求めることができる。つまり、平均粒子径Ｄ５０Ａ及び平均粒子径Ｄ５０Ｂは、走査型電子顕微鏡観察による個数基準の粒度分布において、小粒径側からの積算粒度分布が５０％となる値である。
[Nickel fine particle-containing composition]
Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. FIG. 1 is a schematic diagram showing a configuration of a nickel fine particle-containing composition according to an embodiment of the present invention. In the nickel fine particle-containing composition 100 of the present embodiment, as the component A, the first nickel fine particle 10 having an average particle diameter D50 A in the range of 40 to 200 nm as the component A, and as the component B, the average particle diameter D50 B is It contains the second nickel fine particles 20 in the range of 5 nm or more and less than 40 nm. Here, the average particle diameter (median diameter) D50 of the first nickel fine particles 10 and the second nickel fine particles 20 are both randomized from the sample photographed by SEM (scanning electron microscope). 300 are extracted, the area of each particle is obtained, and the particle diameter when converted into a true sphere can be obtained on the basis of the number. That is, the average particle diameter D50 A and the average particle diameter D50 B are values that give an integrated particle size distribution of 50% from the small particle size side in the number-based particle size distribution observed with a scanning electron microscope.
＜第１のニッケル微粒子＞
本実施の形態のニッケル微粒子含有組成物１００において、第１のニッケル微粒子１０は、走査型電子顕微鏡観察による平均粒子径Ｄ５０Ａが４０〜２００ｎｍの範囲内であり、４５〜１５０ｎｍの範囲内が好ましい。第１のニッケル微粒子１０の平均粒子径Ｄ５０Ａが４０ｎｍを下回ると、それ自体の収縮温度が低くなり、誘電体層とのデラミネーションが激しくなることから、例えばＭＬＣＣの内部電極材料としての実用性を欠く。また、第１のニッケル微粒子１０の平均粒子径Ｄ５０Ａが４０ｎｍを下回ると、脱バインダー時の加熱でニッケル微粒子含有組成物１００同士が凝集又溶融しやすくなり、さらに酸素を取り込みやすくなるため、ニッケル微粒子含有組成物１００の体積膨張や収縮変化が大きくなる。さらに、第１のニッケル微粒子１０の平均粒子径Ｄ５０Ａが４０ｎｍを下回ると、第１のニッケル微粒子１０どうしの隙間が小さくなって第２のニッケル微粒子２０が隙間に入り込むことが困難になり、密度が低下する。そのため、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、熱収縮が大きくなる場合がある。
一方、第１のニッケル微粒子１０の平均粒子径Ｄ５０Ａが２００ｎｍを上回ると、ペースト塗布後の平滑性が低下するとともに、最小径の粒子及び最大径の粒子の分布幅が大きくなり、薄膜化したＭＬＣＣの内部電極材料に利用した場合に、巨大粒子の存在によりショート不良を起こしやすい。
<First nickel fine particles>
In the nickel fine particle-containing composition 100 of the present embodiment, the first nickel fine particles 10 have an average particle diameter D50 A as measured by scanning electron microscope in the range of 40 to 200 nm, preferably in the range of 45 to 150 nm. . When the average particle diameter D50 A of the first nickel fine particles 10 is less than 40 nm, the shrinkage temperature of the first nickel fine particles 10 is lowered, and delamination with the dielectric layer becomes intense. Therefore, practicality as an internal electrode material of MLCC, for example. Lack. Further, when the average particle diameter D50 A of the first nickel fine particles 10 is less than 40 nm, the nickel fine particle-containing compositions 100 are easily aggregated or melted by heating at the time of debinding, and oxygen is easily taken in. The volume expansion or contraction change of the fine particle-containing composition 100 is increased. Furthermore, when the average particle diameter D50 A of the first nickel fine particles 10 is less than 40 nm, the gap between the first nickel fine particles 10 becomes small, and it becomes difficult for the second nickel fine particles 20 to enter the gap, and the density Decreases. Therefore, for example, when the MLCC internal electrode is formed using the nickel fine particle-containing composition 100, thermal shrinkage may increase.
On the other hand, when the average particle diameter D50 A of the first nickel fine particles 10 exceeds 200 nm, the smoothness after applying the paste is lowered, and the distribution width of the minimum diameter particles and the maximum diameter particles is increased, resulting in a thin film. When used as an internal electrode material for MLCC, short-circuit defects are likely to occur due to the presence of large particles.
＜第２のニッケル微粒子＞
また、本実施の形態のニッケル微粒子含有組成物１００において、第２のニッケル微粒子２０は、走査型電子顕微鏡観察による一次粒子の平均粒子径Ｄ５０Ｂが５ｎｍ以上４０ｎｍ未満の範囲内であり、５〜３５ｎｍの範囲内が好ましく、５〜２５ｎｍの範囲内がより好ましく、１０〜２０ｎｍの範囲内がさらに好ましい。第２のニッケル微粒子２０の一次粒子の平均粒子径Ｄ５０Ｂが５ｎｍを下回ると、比表面積が増大し、焼結開始温度が低温化したり、表面自由エネルギーの増大により分散が困難になって第２のニッケル微粒子２０どうしの凝集粒子が増加したりする。また、平均粒子径Ｄ５０Ｂが５ｎｍ未満のニッケル微粒子は、表面の酸化物量が金属ニッケル量に対して大きくなり、還元時の収縮が大きくなってしまうほか、有機物の付着量も大きくなり、その消滅によるガス発生や熱収縮も大きくなるため、好ましくない。
一方、第２のニッケル微粒子２０の一次粒子の平均粒子径Ｄ５０Ｂが４０ｎｍ以上になると、第１のニッケル微粒子１０どうしの隙間に入り込むことが困難になり、密度が低下するため、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、熱収縮が大きくなる場合がある。
<Second nickel fine particles>
In the nickel fine particle-containing composition 100 of the present embodiment, the second nickel fine particles 20 have an average particle diameter D50 B of primary particles as observed by a scanning electron microscope within a range of 5 nm or more and less than 40 nm, It is preferably within the range of 35 nm, more preferably within the range of 5 to 25 nm, and even more preferably within the range of 10 to 20 nm. When the average particle diameter D50 B of the primary particles of the second nickel fine particle 20 is less than 5 nm, the specific surface area increases, the sintering start temperature decreases, and the dispersion becomes difficult due to the increase in surface free energy. The aggregated particles between the nickel fine particles 20 may increase. In addition, nickel fine particles having an average particle diameter D50 B of less than 5 nm have a surface oxide amount larger than the amount of metallic nickel, resulting in a large shrinkage during reduction, and a large amount of organic matter attached, which disappears. This is not preferable because gas generation and heat shrinkage due to the increase are increased.
On the other hand, when the average particle diameter D50 B of the primary particles of the second nickel fine particles 20 is 40 nm or more, it becomes difficult to enter the gaps between the first nickel fine particles 10 and the density decreases. When an MLCC internal electrode is formed using the composition 100, thermal shrinkage may increase.
本実施の形態のニッケル微粒子含有組成物１００は、走査型電子顕微鏡観察によって任意の３００個の第１のニッケル微粒子１０を観察したときに、表面に少なくとも１個以上の第２のニッケル微粒子２０が接触している第１のニッケル微粒子１０の存在確率が３０％以上、好ましくは５０％以上、より好ましくは７５％以上、最も好ましくは９５％以上である。表面に少なくとも１個以上の第２のニッケル微粒子２０が接触している第１のニッケル微粒子１０の存在確率が多くなればなるほど、第１のニッケル微粒子１０に対して、第２のニッケル微粒子２０が均等に分布していることになり、組成物の密度が、単一ピークの粒子径分布を持つ同体積のニッケル微粒子に比べて高くなり、高密度な微粒子混合状態を作り出すことができる。それに対し、表面に少なくとも１個以上の第２のニッケル微粒子２０が接触している第１のニッケル微粒子１０の存在確率が３０％未満である場合、第１のニッケル微粒子１０に対する第２のニッケル微粒子２０の存在状態が、不均一で偏った分布であることを意味する。例えば第２のニッケル微粒子２０の多くが凝集して二次粒子を形成している場合には、表面に少なくとも１個以上の第２のニッケル微粒子２０が接触している第１のニッケル微粒子１０の存在確率が３０％未満となる。このような状態であると、第１のニッケル微粒子１０どうしの隙間に第２のニッケル微粒子２０が入り込むことが困難になり、組成物全体の密度が低下するため、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、熱収縮が大きくなる場合がある。 In the nickel fine particle-containing composition 100 of the present embodiment, when 300 arbitrary first nickel fine particles 10 are observed by observation with a scanning electron microscope, at least one second nickel fine particle 20 is present on the surface. The existence probability of the first nickel fine particles 10 in contact is 30% or more, preferably 50% or more, more preferably 75% or more, and most preferably 95% or more. The higher the probability of existence of the first nickel fine particles 10 having at least one or more second nickel fine particles 20 in contact with the surface, the more the second nickel fine particles 20 are in relation to the first nickel fine particles 10. This means that the density of the composition is higher than that of nickel fine particles of the same volume having a single-peak particle size distribution, and a high-density fine particle mixed state can be created. On the other hand, when the existence probability of the first nickel fine particles 10 having at least one or more second nickel fine particles 20 in contact with the surface is less than 30%, the second nickel fine particles 10 with respect to the first nickel fine particles 10 This means that the existence state of 20 is a non-uniform and biased distribution. For example, when many of the second nickel fine particles 20 are aggregated to form secondary particles, the first nickel fine particles 10 in which at least one or more second nickel fine particles 20 are in contact with the surface. The existence probability is less than 30%. In such a state, it becomes difficult for the second nickel fine particles 20 to enter the gaps between the first nickel fine particles 10 and the density of the entire composition is lowered. When using it to form an internal electrode of MLCC, thermal shrinkage may increase.
本実施の形態のニッケル微粒子含有組成物１００は、走査型電子顕微鏡観察による個数基準の粒度分布において、第１のニッケル微粒子１０の平均粒子径Ｄ５０Ａと、第２のニッケル微粒子２０の平均粒子径Ｄ５０Ｂと、第１のニッケル微粒子１０の小粒径側からの積算粒度分布が１％となる値Ｄ１Ａと、第２のニッケル微粒子２０の小粒径側からの積算粒度分布が９９％となる値Ｄ９９Ｂとが、以下の関係；
Ｄ５０Ａ＞Ｄ５０Ｂ×４ … （１）
かつ
Ｄ１Ａ−Ｄ９９Ｂ ＞ （Ｄ５０Ａ−Ｄ５０Ｂ）／４ … （２）
を満たすことが好ましい。
The nickel fine particle-containing composition 100 of the present embodiment has an average particle diameter D50 A of the first nickel fine particles 10 and an average particle diameter of the second nickel fine particles 20 in the number-based particle size distribution by scanning electron microscope observation. D50 B , a value D1 A at which the cumulative particle size distribution from the small particle size side of the first nickel fine particles 10 is 1%, and an integrated particle size distribution from the small particle size side of the second nickel fine particles 20 is 99%. And the value D99 B has the following relationship:
D50 A > D50 B × 4 (1)
And D1 A -D99 B> (D50 A -D50 B) / 4 ... (2)
It is preferable to satisfy.
上記式（１）を満たすことにより、第１のニッケル微粒子１０と第２のニッケル微粒子２０との大きさ（平均粒子径Ｄ５０）の比が適度になり、組成物全体の密度を高めることができる。その結果、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合の熱収縮を効果的に抑制できる。一方、上記式（１）を満たさない場合、第１のニッケル微粒子１０と第２のニッケル微粒子２０との大きさが近づくため、第１のニッケル微粒子１０どうしの隙間に第２のニッケル微粒子２０が入り込むことが困難になり、密度向上効果が非常に低くなる。そのため、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、熱収縮が大きくなる場合がある。なお、Ｄ５０Ｂに対するＤ５０Ａの比の上限は特に制限はないが、例えば、第１のニッケル微粒子１０の平均粒子径Ｄ５０Ａが１００〜２００ｎｍの範囲内にある場合、Ｄ５０Ｂに対するＤ５０Ａの比の上限は、２０以下であることが好ましく、第１のニッケル微粒子１０の平均粒子径Ｄ５０Ａが４０〜１００ｎｍ未満の範囲内にある場合、Ｄ５０Ｂに対するＤ５０Ａの比の上限は、１５以下であることが好ましい。上記上限を超えると、第２のニッケル微粒子２０が小さくなり過ぎて、比表面積が増大し、焼結開始温度が低温化したり、表面自由エネルギーの増大により分散が困難になって、第２のニッケル微粒子２０どうしの凝集粒子が増加したりする傾向になる。 By satisfy | filling said Formula (1), the ratio of the magnitude | size (average particle diameter D50) of the 1st nickel fine particle 10 and the 2nd nickel fine particle 20 becomes moderate, and it can raise the density of the whole composition. . As a result, for example, thermal shrinkage when forming the MLCC internal electrode using the nickel fine particle-containing composition 100 can be effectively suppressed. On the other hand, when the above formula (1) is not satisfied, the first nickel fine particles 10 and the second nickel fine particles 20 are close in size, so the second nickel fine particles 20 are in the gaps between the first nickel fine particles 10. It becomes difficult to enter, and the density improvement effect is very low. Therefore, for example, when the MLCC internal electrode is formed using the nickel fine particle-containing composition 100, thermal shrinkage may increase. The upper limit of the ratio of D50 A to D50 B is not particularly limited. For example, when the average particle diameter D50 A of the first nickel fine particles 10 is in the range of 100 to 200 nm, the ratio of D50 A to D50 B Is preferably 20 or less, and when the average particle diameter D50 A of the first nickel fine particles 10 is within the range of 40 to less than 100 nm, the upper limit of the ratio of D50 A to D50 B is 15 or less. Preferably there is. When the above upper limit is exceeded, the second nickel fine particles 20 become too small, the specific surface area increases, the sintering start temperature decreases, and the dispersion becomes difficult due to the increase in surface free energy. The agglomerated particles of the fine particles 20 tend to increase.
上記式（２）を満たすことにより、走査型電子顕微鏡観察による個数基準の粒度分布において、第１のニッケル微粒子１０と第２のニッケル微粒子２０の分布に重なりが生じることがなくなる。つまり、第１のニッケル微粒子１０中に含まれる最小粒子よりも、第２のニッケル微粒子２０中に含まれる最大粒子が十分に小さくなり、組成物全体の密度を高めることができる。その結果、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合の熱収縮を効果的に抑制できる。一方、上記式（２）を満たさない場合、第１のニッケル微粒子１０中に含まれる最小粒子と、第２のニッケル微粒子２０中に含まれる最大粒子との大きさが近づくため、第１のニッケル微粒子１０どうしの隙間に第２のニッケル微粒子２０が入り込むことが困難になり、密度向上効果が非常に低くなる。そのため、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、熱収縮が大きくなる場合がある。 By satisfying the above formula (2), the distribution of the first nickel fine particles 10 and the second nickel fine particles 20 does not overlap in the number-based particle size distribution by scanning electron microscope observation. That is, the maximum particles contained in the second nickel fine particles 20 are sufficiently smaller than the minimum particles contained in the first nickel fine particles 10, and the density of the entire composition can be increased. As a result, for example, thermal shrinkage when forming the MLCC internal electrode using the nickel fine particle-containing composition 100 can be effectively suppressed. On the other hand, when the above formula (2) is not satisfied, the size of the first nickel particles is close to the size of the minimum particles contained in the first nickel fine particles 10 and the maximum particles contained in the second nickel fine particles 20. It becomes difficult for the second nickel fine particles 20 to enter the gaps between the fine particles 10, and the density improvement effect becomes very low. Therefore, for example, when the MLCC internal electrode is formed using the nickel fine particle-containing composition 100, thermal shrinkage may increase.
本実施の形態のニッケル微粒子含有組成物１００において、成分Ａと成分Ｂの合計量に対する第１のニッケル微粒子１０の含有量は７５〜９９質量％の範囲内が好ましく、８０〜９５質量％の範囲内がより好ましい。また、本実施の形態のニッケル微粒子含有組成物１００において、Ａ成分と成分Ｂの合計量に対する第２のニッケル微粒子２０の含有量は１〜２５質量％の範囲内が好ましく、５〜２０質量％の範囲内がより好ましい。第１のニッケル微粒子１０の含有量が７５質量％未満である場合、又は第２のニッケル微粒子２０の含有量が２５質量％を超える場合には、平均粒子径の小さな第２のニッケル微粒子２０の比率が多くなり過ぎ、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、熱収縮が大きくなる場合がある。一方、第１のニッケル微粒子１０の含有量が９９質量％を超える場合、又は第２のニッケル微粒子２０の含有量が１質量％を下回る場合には、第１のニッケル微粒子１０どうしの隙間を第２のニッケル微粒子２０で埋めることが困難になり、密度が低下するため、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、熱収縮が大きくなる場合がある。 In the nickel fine particle-containing composition 100 of the present embodiment, the content of the first nickel fine particles 10 with respect to the total amount of the component A and the component B is preferably in the range of 75 to 99% by mass, and in the range of 80 to 95% by mass. The inside is more preferable. In the nickel fine particle-containing composition 100 of the present embodiment, the content of the second nickel fine particles 20 relative to the total amount of the component A and the component B is preferably in the range of 1 to 25% by mass, and 5 to 20% by mass. The range of is more preferable. When the content of the first nickel fine particles 10 is less than 75% by mass, or when the content of the second nickel fine particles 20 exceeds 25% by mass, the second nickel fine particles 20 having a small average particle diameter For example, when the internal electrode of MLCC is formed using the nickel fine particle-containing composition 100, the thermal shrinkage may increase. On the other hand, when the content of the first nickel fine particles 10 exceeds 99% by mass, or when the content of the second nickel fine particles 20 is less than 1% by mass, the gap between the first nickel fine particles 10 is changed to the first. Therefore, when the MLCC internal electrode is formed by using the nickel fine particle-containing composition 100, for example, the thermal shrinkage may be increased.
本実施の形態のニッケル微粒子含有組成物１００において、第１のニッケル微粒子１０及び第２のニッケル微粒子２０は、いずれも、粒子径の変動係数（ＣＶ）が０．２５以下であることが好ましい。ＣＶ値を０．２５以下とすることで、第１のニッケル微粒子１０と第２のニッケル微粒子２０の粒度分布がシャープとなるため、平均粒子径が異なるこれらの粒子を組み合わせる効果が高まる。従って、ニッケル微粒子含有組成物１００を用いて、例えばＭＬＣＣの内部電極を形成する場合に、高い密度が得られ、熱収縮を抑制する効果が増大する。 In the nickel fine particle-containing composition 100 of the present embodiment, it is preferable that the first nickel fine particle 10 and the second nickel fine particle 20 both have a coefficient of variation (CV) in particle diameter of 0.25 or less. By setting the CV value to 0.25 or less, the particle size distribution of the first nickel fine particles 10 and the second nickel fine particles 20 becomes sharp, so that the effect of combining these particles having different average particle diameters is enhanced. Therefore, for example, when an MLCC internal electrode is formed using the nickel fine particle-containing composition 100, a high density is obtained and the effect of suppressing thermal shrinkage is increased.
本実施の形態のニッケル微粒子含有組成物１００において、第１のニッケル微粒子１０及び第２のニッケル微粒子２０は、例えば球状、疑似球状等の形状の微粒子であり、主成分としてニッケル元素を含有するとともに、ニッケル元素に対して相対的に少量の銅元素を含有する。第１のニッケル微粒子１０及び第２のニッケル微粒子２０は、それぞれ、ニッケル及び銅以外の元素を含有することができる。ニッケル及び銅以外の金属としては、例えば、チタン、コバルト、クロム、マンガン、鉄、アルミニウム、ナトリウム、カリウム、マグネシウム、ジルコニウム、スズ、タングステン、モリブデン、バナジウム、バリウム、カルシウム、ストロンチウム、シリコン、アルミニウム、リン等の卑金属、金、銀、白金、パラジウム、イリジウム、オスミウム、ルテニウム、ロジウム、レニウム、ネオジウム、ニオブ、ホロニウム、ディスプロヂウム、イットリウム等の貴金属、希土類金属を挙げることができる。これらは、単独で又は２種以上含有していてもよく、また、酸素、水素、炭素、窒素、硫黄、ボロン等の金属元素以外の元素を含有していてもよいし、これらの合金であってもよい。 In the nickel fine particle-containing composition 100 of the present embodiment, the first nickel fine particles 10 and the second nickel fine particles 20 are fine particles having a shape such as a spherical shape or a pseudo spherical shape, and contain nickel element as a main component. And a relatively small amount of copper element relative to nickel element. The first nickel fine particles 10 and the second nickel fine particles 20 can contain elements other than nickel and copper, respectively. Examples of metals other than nickel and copper include titanium, cobalt, chromium, manganese, iron, aluminum, sodium, potassium, magnesium, zirconium, tin, tungsten, molybdenum, vanadium, barium, calcium, strontium, silicon, aluminum, and phosphorus. Base metals such as gold, silver, platinum, palladium, iridium, osmium, ruthenium, rhodium, rhenium, neodymium, niobium, holonium, dysprodium, yttrium and the like, and rare earth metals. These may be contained alone or in combination of two or more, may contain elements other than metal elements such as oxygen, hydrogen, carbon, nitrogen, sulfur and boron, and may be alloys thereof. May be.
第１のニッケル微粒子１０は、分散性を向上させるため、ニッケル元素に対する銅元素の含有割合が、０．０１質量％以上２質量％以下の範囲内であることが好ましく、０．０１質量％以上１．２質量％以下の範囲内であることがより好ましい。第１のニッケル微粒子１０中に含有される銅元素は、凝集の原因となるニッケル微粒子の磁性を弱め、分散性の向上に寄与する。従って、第１のニッケル微粒子１０において、ニッケル元素に対する銅元素の含有割合が０．０１質量％未満であると、分散性の改善効果が得られない。一方、第１のニッケル微粒子１０において、ニッケル元素に対する銅元素の含有割合が、２質量％を超えると銅元素の存在による粒子の酸化安定性の低下が生じ、さらには、ＭＬＣＣの内部電極用の導電性ペースト材料として用いる場合に、脱バインダー工程において、銅の酸化が急速に起こり、クラックや層間剥離などの不具合が発生しやすくなる。また、第１のニッケル微粒子１０において、銅元素の４０〜９０％は、第１のニッケル微粒子１０の中心から径方向に±５ｎｍの範囲より外側に分散し、ニッケル元素と合金化した状態で存在していることが好ましい。このような銅元素の分散状態によって、ニッケル粒子の磁性を弱め、凝集を抑制して分散性を改善することができる。 In order to improve the dispersibility of the first nickel fine particles 10, the content ratio of the copper element with respect to the nickel element is preferably in the range of 0.01% by mass to 2% by mass, and 0.01% by mass or more More preferably, it is in the range of 1.2 mass% or less. The copper element contained in the first nickel fine particles 10 weakens the magnetic properties of the nickel fine particles that cause aggregation and contributes to the improvement of dispersibility. Therefore, in the first nickel fine particles 10, when the content ratio of the copper element to the nickel element is less than 0.01% by mass, the effect of improving the dispersibility cannot be obtained. On the other hand, if the content ratio of the copper element with respect to the nickel element in the first nickel fine particle 10 exceeds 2 mass%, the oxidation stability of the particle is reduced due to the presence of the copper element, and further, for the internal electrode of the MLCC. When used as a conductive paste material, copper oxidation occurs rapidly in the debinding process, and defects such as cracks and delamination tend to occur. Further, in the first nickel fine particles 10, 40 to 90% of the copper element is dispersed outside the range of ± 5 nm in the radial direction from the center of the first nickel fine particles 10 and is present in an alloyed state with the nickel element. It is preferable. By such a dispersed state of the copper element, the magnetic properties of the nickel particles can be weakened, aggregation can be suppressed, and the dispersibility can be improved.
また、第２のニッケル微粒子２０も、ニッケル元素に対する銅元素の含有割合が、３質量％以上４０質量％以下の範囲内で銅元素を含有していることが好ましく、１０質量％以上３０質量％以下の範囲内であることがより好ましい。第２のニッケル微粒子２０中に含有される銅元素は、凝集の原因となるニッケル粒子の磁性を弱め、分散性の向上に寄与する。従って、第２のニッケル微粒子２０において、ニッケル元素に対する銅元素の含有割合が３質量％未満であると、分散性の改善効果が得られない。一方、第２のニッケル微粒子２０において、ニッケル元素に対する銅元素の含有割合が、４０質量％を超えると銅元素の存在による粒子の酸化安定性の低下が生じ、さらには、ＭＬＣＣの内部電極用の導電性ペースト材料として用いる場合に、脱バインダー工程において、銅の酸化が急速に起こり、クラックや層間剥離などの不具合が発生しやすくなる。 Moreover, it is preferable that the content rate of the copper element with respect to the nickel element also contains the copper element in the 2nd nickel fine particle 20 within the range of 3 mass% or more and 40 mass% or less, and 10 mass% or more and 30 mass%. More preferably within the following range. The copper element contained in the second nickel fine particles 20 weakens the magnetic properties of the nickel particles that cause aggregation and contributes to an improvement in dispersibility. Therefore, in the second nickel fine particles 20, when the content ratio of the copper element to the nickel element is less than 3% by mass, the effect of improving the dispersibility cannot be obtained. On the other hand, in the second nickel fine particle 20, when the content ratio of the copper element with respect to the nickel element exceeds 40% by mass, the oxidation stability of the particle is reduced due to the presence of the copper element, and further, for the internal electrode of the MLCC. When used as a conductive paste material, copper oxidation occurs rapidly in the debinding process, and defects such as cracks and delamination tend to occur.
また、本実施の形態のニッケル微粒子含有組成物１００は、第１のニッケル微粒子１０に含まれる銅元素及び第２のニッケル微粒子２０に含まれる銅元素の合計量が、第１のニッケル微粒子１０及び第２のニッケル微粒子２０の合計量に対し、０．５質量％以上１０質量％以下の範囲内であり、０．８質量％以上８．０質量％以下の範囲内であることがより好ましい。第１のニッケル微粒子１０及び第２のニッケル微粒子２０の全体に対する銅元素の含有割合が０．５質量％未満であると、分散性の改善効果が得られず、１０質量％を超えると銅元素の存在による粒子の酸化安定性の低下が生じ、さらには、ＭＬＣＣの内部電極用の導電性ペースト材料として用いる場合に、脱バインダー工程において、銅の酸化が急速に起こり、クラックや層間剥離などの不具合が発生しやすくなる。
The nickel fine particle-containing composition 100 of the present embodiment is such that the total amount of the copper element contained in the first nickel fine particle 10 and the copper element contained in the second nickel fine particle 20 is the first nickel fine particle 10 and With respect to the total amount of the second nickel fine particles 20, it is in the range of 0.5% by mass or more and 10% by mass or less, and more preferably in the range of 0.8% by mass or more and 8.0% by mass or less. When the content ratio of the copper element with respect to the whole of the first nickel fine particles 10 and the second nickel fine particles 20 is less than 0.5% by mass, the effect of improving the dispersibility cannot be obtained. In addition, when used as a conductive paste material for MLCC internal electrodes, copper oxidation occurs rapidly in the debinding process, and cracks, delamination, etc. occur. Problems are likely to occur.
また、第１のニッケル微粒子１０及び第２のニッケル微粒子２０は、金属として、銅以外のものを用いる場合、例えば、銀などのニッケル以外の異種金属によるマイグレーションによるショートや静電容量の低下などの製品不良を防止する観点から、銅以外の金属元素の含有量を０．０１質量％以上２質量％以下の範囲内とすることが好ましい。 In addition, when the first nickel fine particles 10 and the second nickel fine particles 20 use a metal other than copper, for example, a short circuit due to migration by a dissimilar metal other than nickel such as silver or a decrease in capacitance. From the viewpoint of preventing product defects, the content of metal elements other than copper is preferably in the range of 0.01% by mass to 2% by mass.
本実施の形態のニッケル微粒子含有組成物１００において、第１のニッケル微粒子１０及び第２のニッケル微粒子２０は、それぞれ、金属成分を９０質量％以上含有することが好ましい。金属成分の含有量が９０質量％未満であると、電気抵抗が大きくなり、例えばＭＬＣＣの内部電極材料用途として好ましくない。なお、各種元素の含有量は、元素分析により確認することができる（以下、同様である）。 In the nickel fine particle-containing composition 100 of the present embodiment, each of the first nickel fine particles 10 and the second nickel fine particles 20 preferably contains 90% by mass or more of a metal component. When the content of the metal component is less than 90% by mass, the electric resistance increases, which is not preferable for use as an internal electrode material for MLCC, for example. The contents of various elements can be confirmed by elemental analysis (the same applies hereinafter).
本実施の形態において、第１のニッケル微粒子１０及び第２のニッケル微粒子２０は、それぞれ、後述するように、ニッケル塩及び有機アミンを含む混合物から、湿式還元法によりニッケルイオンを還元し、金属ニッケルを析出させて得られるものであることが好ましい。特に、ニッケル塩及び有機アミンを含む錯化反応液をマイクロ波照射加熱によって湿式還元する方法では、錯化反応液の均一加熱が可能であり、かつエネルギーを媒体に直接与えることができるため、急速加熱を行なうことができる。これにより、錯化反応液全体を所望の温度に均一に加熱することができ、ニッケル錯体（又はニッケルイオン）の還元、核生成、核成長各々の過程を溶液全体において同時に生じさせ、ＣＶ値が小さい単分散なニッケル微粒子（第１のニッケル微粒子１０又は第２のニッケル微粒子２０）を短時間で容易に製造することができる。また、第１のニッケル微粒子１０及び第２のニッケル微粒子２０を、ともに、金属塩及び有機アミンを含む錯化反応液から加熱還元して製造することによって、これら２種類のニッケル微粒子の表面状態（例えば、有機アミンなどの付着物、酸化皮膜など）が、ほぼ同様になるため、溶媒中での分散性も同程度となり、ハンドリングが容易になる。 In the present embodiment, the first nickel fine particles 10 and the second nickel fine particles 20 are obtained by reducing nickel ions by a wet reduction method from a mixture containing a nickel salt and an organic amine, as will be described later. It is preferable that it is obtained by precipitating. In particular, in the method of wet reduction of a complexing reaction solution containing a nickel salt and an organic amine by microwave irradiation heating, the complexing reaction solution can be heated uniformly and energy can be directly applied to the medium. Heating can be performed. As a result, the entire complexing reaction solution can be uniformly heated to a desired temperature, and the nickel complex (or nickel ion) reduction, nucleation, and nucleation processes are simultaneously generated in the entire solution, and the CV value is Small monodispersed nickel fine particles (first nickel fine particles 10 or second nickel fine particles 20) can be easily produced in a short time. Further, both the first nickel fine particles 10 and the second nickel fine particles 20 are produced by heat reduction from a complexing reaction solution containing a metal salt and an organic amine, so that the surface state of these two kinds of nickel fine particles ( For example, deposits such as organic amines, oxide films, etc.) are almost the same, so that the dispersibility in the solvent is the same and handling is easy.
本実施の形態のニッケル微粒子含有組成物１００は、任意の溶媒に分散させたスラリーの状態でもよいし、溶媒を除去して乾燥させた粉末状の形態をなしていてもよい。スラリーとする場合の溶媒としては、第１のニッケル微粒子１０及び第２のニッケル微粒子２０を分散できるものであれば特に制限はないが、例えばエチレングリコール等のグリコール類、アルコール類、有機アミン類、Ｎ，Ｎ−ジメチルホルムアミド、ジメチルスルホキシド、アセトン等が挙げられる。 The nickel fine particle-containing composition 100 of the present embodiment may be in the form of a slurry dispersed in an arbitrary solvent, or may be in the form of a powder that is dried by removing the solvent. The solvent for the slurry is not particularly limited as long as the first nickel fine particles 10 and the second nickel fine particles 20 can be dispersed. For example, glycols such as ethylene glycol, alcohols, organic amines, N, N-dimethylformamide, dimethyl sulfoxide, acetone and the like can be mentioned.
本実施の形態のニッケル微粒子含有組成物１００は、上記溶媒以外の他の任意成分を含有していてもよい。そのような任意成分としては、例えば熱収縮温度を上げるために、誘電体組成と類似の共材や、シリカ、マグネシア、カルシア、チタニア、希土類金属酸化物などの誘電体層に添加される金属酸化物等を挙げることができる。 The nickel fine particle-containing composition 100 of the present embodiment may contain other optional components other than the solvent. Such optional components include, for example, metal oxides added to dielectric layers similar to dielectric compositions and dielectric layers such as silica, magnesia, calcia, titania, rare earth metal oxides to increase the heat shrink temperature. And the like.
＜共材＞
本実施の形態のニッケル微粒子含有組成物１００は、共材を含有することが好ましい。共材としては、例えばＭＬＣＣの誘電体層の材料に用いるＢａＴｉＯ３、ＳｒＴｉＯ３、ＣａＴｉＯ３などを挙げることができる。共材を添加することによって、高密度化が可能になり、ニッケル微粒子含有組成物１００を例えばＭＬＣＣの内部電極材料として使用する場合に収縮率を抑えることが可能となる。共材は、例えば走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０が２０〜６０ｎｍの範囲内のものを使用することが好ましい。共材の添加量は、ニッケル微粒子含有組成物１００質量部に対して５〜２０質量部とすることが好ましい。共材の添加量が５質量部を下回ると、添加の効果が得られず、２０質量部を上回ると、例えばニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合に、共材が誘電体層へ拡散することで誘電体層の膜厚が増大し、電気容量が低下するのみならず、電気抵抗が上昇し、導電性が低下する場合がある。
<Co-material>
The nickel fine particle-containing composition 100 of the present embodiment preferably contains a common material. Examples of the co-material include BaTiO 3 , SrTiO 3 , and CaTiO 3 used for the material of the dielectric layer of MLCC. By adding the co-material, it is possible to increase the density, and it is possible to suppress the shrinkage rate when the nickel fine particle-containing composition 100 is used as an internal electrode material of MLCC, for example. It is preferable to use a common material having a mean particle diameter D50 in the range of 20 to 60 nm, for example, in a number-based particle size distribution observed with a scanning electron microscope. The addition amount of the common material is preferably 5 to 20 parts by mass with respect to 100 parts by mass of the nickel fine particle-containing composition. When the addition amount of the common material is less than 5 parts by mass, the effect of the addition cannot be obtained. When the addition amount exceeds 20 parts by mass, for example, when the internal electrode of MLCC is formed using the nickel fine particle-containing composition 100, the common material is used. As a result of diffusion into the dielectric layer, the film thickness of the dielectric layer increases, and not only the electric capacity decreases, but also the electric resistance increases and the conductivity may decrease.
本実施の形態のニッケル微粒子含有組成物１００を粉末状の形態とする場合、第１のニッケル微粒子１０と第２のニッケル微粒子２０が凝集して２次粒子を形成していてもよい。この場合も、第１のニッケル微粒子１０の表面に接触して、第２のニッケル微粒子２０がほぼ均等に分布して存在する状態であることが好ましい。また、個々の２次粒子における第１のニッケル微粒子１０の含有比率が７５〜９９質量％の範囲内であり、かつ第２のニッケル微粒子２０の含有比率が１〜２５質量％の範囲内であることが好ましい。すなわち、本実施の形態のニッケル微粒子含有組成物１００は、粉末状の形態である場合に、凝集粒子である２次粒子を有していてもよいが、個々の２次粒子内において、第１のニッケル微粒子１０と第２のニッケル微粒子２０との比率は、組成物全体における第１のニッケル微粒子１０と前記第２のニッケル微粒子２０の比率にほぼ等しいことが好ましい。このように、個々の２次粒子の組成と、組成物全体の組成が略等しいということは、組成物全体が均質な状態にあることを意味する。組成物が全体として均質であれば、個々の凝集粒子においても、第１のニッケル微粒子１０どうしの隙間に第２のニッケル微粒子２０が効率よく入り込んだ状態が維持されるため、粒子密度を高めることが可能になり、ニッケル微粒子含有組成物１００を用いて例えばＭＬＣＣの内部電極を形成する場合の熱収縮を効果的に抑制できる。それに対し、例えば２次粒子毎に第１のニッケル微粒子１０と第２のニッケル微粒子２０との比率が大きく変動する場合には、組成物内部で第１のニッケル微粒子１０及び第２のニッケル微粒子２０の分布が偏在していることを意味する。このような場合は、粒子密度を高めることが困難になり、ニッケル微粒子含有組成物１００を用いてＭＬＣＣの内部電極を形成する場合の熱収縮を抑制する効果が十分に得られなくなる。別の観点から、ニッケル微粒子含有組成物１００中で第１のニッケル微粒子１０と第２のニッケル微粒子２０のそれぞれが偏在していない均質な状態であれば、ペースト化工程における均質化も比較的容易となり、工業的にも有利である。 When the nickel fine particle-containing composition 100 of the present embodiment is in a powder form, the first nickel fine particles 10 and the second nickel fine particles 20 may be aggregated to form secondary particles. Also in this case, it is preferable that the second nickel fine particles 20 are present in a substantially uniform distribution in contact with the surface of the first nickel fine particles 10. Further, the content ratio of the first nickel fine particles 10 in the individual secondary particles is in the range of 75 to 99% by mass, and the content ratio of the second nickel fine particles 20 is in the range of 1 to 25% by mass. It is preferable. That is, the nickel fine particle-containing composition 100 of the present embodiment may have secondary particles that are aggregated particles when in the form of a powder. The ratio between the nickel fine particles 10 and the second nickel fine particles 20 is preferably substantially equal to the ratio between the first nickel fine particles 10 and the second nickel fine particles 20 in the entire composition. Thus, the fact that the composition of the individual secondary particles and the composition of the entire composition are substantially equal means that the entire composition is in a homogeneous state. If the composition is homogeneous as a whole, the state in which the second nickel fine particles 20 efficiently enter the gaps between the first nickel fine particles 10 is maintained even in the individual agglomerated particles, thereby increasing the particle density. Thus, for example, when the internal electrode of MLCC is formed using the nickel fine particle-containing composition 100, thermal contraction can be effectively suppressed. On the other hand, for example, when the ratio of the first nickel fine particles 10 and the second nickel fine particles 20 varies greatly for each secondary particle, the first nickel fine particles 10 and the second nickel fine particles 20 are formed inside the composition. This means that the distribution of is unevenly distributed. In such a case, it is difficult to increase the particle density, and the effect of suppressing thermal shrinkage when forming the MLCC internal electrode using the nickel fine particle-containing composition 100 cannot be sufficiently obtained. From another point of view, if the first nickel fine particles 10 and the second nickel fine particles 20 are not unevenly distributed in the nickel fine particle-containing composition 100, homogenization in the pasting process is relatively easy. This is industrially advantageous.
［ニッケル微粒子含有組成物の製造方法］
次に、本実施の形態のニッケル微粒子含有組成物１００の製造方法について説明する。ニッケル微粒子含有組成物１００は、例えば、第１のニッケル微粒子１０と第２のニッケル微粒子２０を別々に調製した後、混合することによって製造することができる。第１のニッケル微粒子１０及び第２のニッケル微粒子２０は、それぞれ、例えば気相法や液相法などの方法により製造可能であり、その製造方法については特に限定されない。気相法は液相法に比べて製造コストが高価になりがちであるので、液相法を適用することが有利である。液相法のなかでも、粒子径分布が狭いニッケル微粒子を短時間で容易に製造できる方法として、湿式還元工程を有する方法が好ましい。第１のニッケル微粒子１０と第２のニッケル微粒子２０を共に後述する湿式還元法によって製造することによって、第１のニッケル微粒子１０と第２のニッケル微粒子２０の表面状態がほぼ同様の性質を持つようになる。そのため、第１のニッケル微粒子１０と第２のニッケル微粒子２０は、近似した分散挙動を示すようになり、両者を混合した後も、均一な分散状態を得ることができる。
[Production method of nickel fine particle-containing composition]
Next, the manufacturing method of the nickel fine particle containing composition 100 of this Embodiment is demonstrated. The nickel fine particle-containing composition 100 can be produced, for example, by separately preparing the first nickel fine particles 10 and the second nickel fine particles 20 and then mixing them. Each of the first nickel fine particles 10 and the second nickel fine particles 20 can be produced by a method such as a gas phase method or a liquid phase method, and the production method is not particularly limited. Since the gas phase method tends to be expensive to produce compared to the liquid phase method, it is advantageous to apply the liquid phase method. Among liquid phase methods, a method having a wet reduction step is preferable as a method for easily producing nickel fine particles having a narrow particle size distribution in a short time. By producing both the first nickel fine particles 10 and the second nickel fine particles 20 by the wet reduction method described later, the surface states of the first nickel fine particles 10 and the second nickel fine particles 20 have substantially the same properties. become. Therefore, the first nickel fine particles 10 and the second nickel fine particles 20 show an approximate dispersion behavior, and a uniform dispersion state can be obtained even after both are mixed.
本実施の形態のニッケル微粒子含有組成物１００の好ましい製造方法は、例えば、下記の工程ａ〜ｄ；
ａ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０が４０〜２００ｎｍの範囲内である第１のニッケル微粒子のスラリーを得る工程、
ｂ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０が５ｎｍ以上４０ｎｍ未満の範囲内である第２のニッケル微粒子のスラリーを得る工程、
ｃ）前記第２のニッケル微粒子を溶剤で洗浄する工程、
及び
ｄ）前記第１のニッケル微粒子と前記第２のニッケル微粒子とを混合する工程。
A preferred method for producing the nickel fine particle-containing composition 100 of the present embodiment is, for example, the following steps a to d;
a) obtaining a slurry of first nickel fine particles having an average particle diameter D50 in the range of 40 to 200 nm in a number-based particle size distribution by scanning electron microscope observation;
b) a step of obtaining a slurry of second nickel fine particles having an average particle diameter D50 in the range of 5 nm or more and less than 40 nm in a number-based particle size distribution by scanning electron microscope observation;
c) washing the second nickel fine particles with a solvent;
And d) mixing the first nickel fine particles and the second nickel fine particles.
また、本実施の形態のニッケル微粒子含有組成物１００の好ましい製造方法において、前記工程ｃは、前記第２のニッケル微粒子の平均粒子径Ｄ５０に対して１０％以上小さな平均孔径を有するフィルタを用い、前記第２のニッケル微粒子を前記溶剤とともに前記フィルタでろ過することにより行われ、
かつ、
前記工程ｄは、前記工程ｃと同時に、又は前記工程ｃの後で引き続き、前記フィルタで前記第１のニッケル微粒子をろ過することによって行われる。
Further, in a preferred method for producing the nickel fine particle-containing composition 100 of the present embodiment, the step c uses a filter having an average pore diameter that is 10% or more smaller than the average particle diameter D50 of the second nickel fine particles. It is performed by filtering the second nickel fine particles together with the solvent through the filter,
And,
The step d is performed by filtering the first nickel fine particles with the filter simultaneously with the step c or after the step c.
以下、工程ａ〜ｄについて説明する。
［工程ａ］
工程ａでは、ニッケル塩と、脂肪族１級モノアミンと、を混合し、加熱することによってニッケル塩を有機アミンに溶解させたニッケル錯体溶液を準備し、このニッケル錯体溶液を湿式加熱還元することによって、第１のニッケル微粒子１０を製造することができる。第１のニッケル微粒子１０は、粒子内部に銅元素が拡散していても良い。粒子内部に銅元素が拡散していることによって、第１のニッケル微粒子１０は、ニッケルの磁性が緩和され、磁性による凝集が抑制されるため、分散性が向上するので好ましい。
Hereinafter, steps a to d will be described.
[Step a]
In step a, the nickel salt and the aliphatic primary monoamine are mixed and heated to prepare a nickel complex solution in which the nickel salt is dissolved in the organic amine, and the nickel complex solution is subjected to wet heat reduction. The first nickel fine particles 10 can be manufactured. In the first nickel fine particles 10, copper element may be diffused inside the particles. When the copper element is diffused inside the particles, the first nickel fine particles 10 are preferable because the magnetism of nickel is relaxed and aggregation due to magnetism is suppressed, so that dispersibility is improved.
（ニッケル塩）
工程ａにおいて、ニッケル塩の種類は特に限定されず、例えば水酸化ニッケル、塩化ニッケル、硝酸ニッケル、硫酸ニッケル、炭酸ニッケル、カルボン酸ニッケル、Ｎｉ（ａｃａｃ）２（β−ジケトナト錯体）、ステアリン酸ニッケル等が挙げられるが、この中でも、塩化ニッケル又はカルボン酸ニッケルが好ましく、還元過程での解離温度（分解温度）が比較的低いカルボン酸ニッケルを用いることが有利である。カルボン酸ニッケルとしては、例えば、還元過程での解離温度（分解温度）が比較的低いギ酸ニッケル、酢酸ニッケルなどを用いることが好ましい。カルボン酸ニッケルは、無水物であってもよく、また水和物であってもよい。なお、カルボン酸ニッケルに代えて、塩化ニッケル、硝酸ニッケル、硫酸ニッケル、炭酸ニッケル、水酸化ニッケル等の無機塩を用いることも考えられるが、無機塩の場合、解離(分解)が高温であるため、還元過程で高温での加熱が必要であり好ましくない。また、Ｎｉ（ａｃａｃ）２（β−ジケトナト錯体)、ステアリン酸イオン等の有機配位子により構成されるニッケル塩を用いることも考えられるが、これらのニッケル塩を用いると、原料コストが高くなり好ましくない。カルボン酸ニッケルは単独で用いてもよいし、他のニッケル塩と併用することもできる。
(Nickel salt)
In the step a, the kind of nickel salt is not particularly limited. For example, nickel hydroxide, nickel chloride, nickel nitrate, nickel sulfate, nickel carbonate, nickel carboxylate, Ni (acac) 2 (β-diketonato complex), nickel stearate Among them, nickel chloride or nickel carboxylate is preferable, and it is advantageous to use nickel carboxylate having a relatively low dissociation temperature (decomposition temperature) in the reduction process. As nickel carboxylate, for example, nickel formate or nickel acetate having a relatively low dissociation temperature (decomposition temperature) in the reduction process is preferably used. The nickel carboxylate may be an anhydride or a hydrate. In addition, it is possible to use inorganic salts such as nickel chloride, nickel nitrate, nickel sulfate, nickel carbonate, nickel hydroxide instead of nickel carboxylate, but in the case of inorganic salts, dissociation (decomposition) is high temperature. In the reduction process, heating at a high temperature is necessary, which is not preferable. It is also possible to use nickel salts composed of organic ligands such as Ni (acac) 2 (β-diketonato complex) and stearate ions, but using these nickel salts increases the cost of raw materials. It is not preferable. The nickel carboxylate may be used alone or in combination with other nickel salts.
（有機アミン）
有機アミンは、ニッケルイオンとの錯体を形成できるものであれば、特に限定されず、常温で固体又は液体のものが使用できる。ここで、常温とは、２０℃±１５℃をいう。常温で液体の有機アミンは、ニッケル錯体を形成する際の有機溶媒としても機能する。なお、常温で固体の有機アミンであっても、加熱によって液体であるか、又は有機溶媒を用いて溶解するものであれば、特に問題はない。
(Organic amine)
The organic amine is not particularly limited as long as it can form a complex with nickel ions, and can be solid or liquid at room temperature. Here, room temperature means 20 ° C. ± 15 ° C. The organic amine that is liquid at room temperature also functions as an organic solvent for forming the nickel complex. In addition, even if it is a solid organic amine at normal temperature, if it is a liquid by heating or melt | dissolves using an organic solvent, there will be no problem in particular.
有機アミンとしては、脂肪族１級モノアミンを用いることが好ましい。一方、２級アミンは立体障害が大きいため、ニッケル錯体の良好な形成を阻害するおそれがあり、３級アミンはニッケルイオンの還元能を有しないため、いずれも使用できない。また、ジアミンは、金属イオンの中でも特にニッケルイオンと形成した錯体の安定性が高く、その還元温度は高くなるため反応性が非常に低く、生成するニッケル粒子に歪が生じやすくなるため好ましくない。 As the organic amine, an aliphatic primary monoamine is preferably used. On the other hand, secondary amines have great steric hindrance and may hinder good formation of nickel complexes, and tertiary amines cannot be used because they do not have the ability to reduce nickel ions. Also, diamines are not preferred because of the high stability of complexes formed with nickel ions, among metal ions, and the reduction temperature is high, so that the reactivity is very low and the resulting nickel particles are easily distorted.
脂肪族１級モノアミンは、例えばその炭素鎖の長さを調整することによって生成する第１のニッケル微粒子１０の粒径を制御することができる。第１のニッケル微粒子１０の粒径を制御する観点から、脂肪族１級モノアミンは、その炭素数が６〜２０程度のものから選択して用いることが好適である。炭素数が多いほど得られる第１のニッケル微粒子１０の粒径が小さくなる。このようなアミンとして、例えばオクチルアミン、トリオクチルアミン、ジオクチルアミン、ヘキサデシルアミン、ドデシルアミン、テトラデシルアミン、ステアリルアミン、オレイルアミン、ミリスチルアミン、ラウリルアミン等を挙げることができる。 The aliphatic primary monoamine can control the particle diameter of the first nickel fine particles 10 produced by adjusting the length of the carbon chain, for example. From the viewpoint of controlling the particle diameter of the first nickel fine particles 10, the aliphatic primary monoamine is preferably selected from those having about 6 to 20 carbon atoms. The larger the number of carbon atoms, the smaller the particle diameter of the first nickel fine particles 10 obtained. Examples of such amines include octylamine, trioctylamine, dioctylamine, hexadecylamine, dodecylamine, tetradecylamine, stearylamine, oleylamine, myristylamine, and laurylamine.
脂肪族１級モノアミンは、第１のニッケル微粒子１０の生成時に表面修飾剤として機能するため、脂肪族１級モノアミンの除去後においても二次凝集を抑制できる。また、脂肪族１級モノアミンは、還元反応後の生成した第１のニッケル微粒子１０の固体成分と溶剤又は未反応の脂肪族１級モノアミン等を分離する洗浄工程における処理操作の容易性の観点からも好ましい。更に、脂肪族１級モノアミンは、ニッケル錯体を還元して第１のニッケル微粒子１０を得るときの反応制御の容易性の観点からは還元温度より沸点が高いものが好ましい。すなわち、脂肪族１級モノアミンは、沸点が１８０℃以上のものが好ましく、２００℃以上のものがより好ましい。また、脂肪族１級モノアミンは、炭素数が９以上であることが好ましい。ここで、例えば炭素数が９である脂肪族１級モノアミンのＣ９Ｈ２１Ｎ(ノニルアミン)の沸点は２０１℃である。 Since the aliphatic primary monoamine functions as a surface modifier when the first nickel fine particles 10 are produced, secondary aggregation can be suppressed even after the removal of the aliphatic primary monoamine. In addition, the aliphatic primary monoamine is used from the viewpoint of ease of processing operation in the washing step of separating the solid component of the first nickel fine particles 10 produced after the reduction reaction and the solvent or the unreacted aliphatic primary monoamine. Is also preferable. Further, the aliphatic primary monoamine is preferably one having a boiling point higher than the reduction temperature from the viewpoint of ease of reaction control when the nickel complex is reduced to obtain the first nickel fine particles 10. That is, the aliphatic primary monoamine has a boiling point of preferably 180 ° C. or higher, more preferably 200 ° C. or higher. The aliphatic primary monoamine preferably has 9 or more carbon atoms. Here, for example, the boiling point of C 9 H 21 N (nonylamine), which is an aliphatic primary monoamine having 9 carbon atoms, is 201 ° C.
（有機溶媒）
脂肪族１級モノアミンは、有機溶媒として反応を進行させることができるが、均一溶液での反応をより効率的に進行させるために、第１のニッケル微粒子１０の調製において、脂肪族１級モノアミンとは別の有機溶媒を新たに添加してもよい。使用できる有機溶媒としては、脂肪族１級モノアミンと、ニッケルイオン、銅イオンなどの金属イオンとの錯形成を阻害しないものであれば、特に限定するものではなく、例えば炭素数４〜３０のエーテル系有機溶媒、炭素数７〜３０の飽和又は不飽和の炭化水素系有機溶媒、炭素数８〜１８のアルコール系有機溶媒等を使用することができる。また、マイクロ波照射による加熱条件下でも使用を可能とする観点から、使用する有機溶媒は、沸点が１７０℃以上のものを選択することが好ましく、より好ましくは２００〜３００℃の範囲内にあるものを選択することがよい。このような有機溶媒の具体例としては、例えばテトラエチレングリコール、ｎ−オクチルエーテル、炭素数が２０〜４０の範囲内にあるポリアルファオレフィン等が挙げられる。
(Organic solvent)
Although the aliphatic primary monoamine can proceed as an organic solvent, in order to proceed the reaction in a homogeneous solution more efficiently, in the preparation of the first nickel fine particles 10, an aliphatic primary monoamine and Another organic solvent may be newly added. The organic solvent that can be used is not particularly limited as long as it does not inhibit complex formation between an aliphatic primary monoamine and a metal ion such as nickel ion or copper ion. For example, an ether having 4 to 30 carbon atoms. An organic organic solvent, a saturated or unsaturated hydrocarbon organic solvent having 7 to 30 carbon atoms, an alcohol organic solvent having 8 to 18 carbon atoms, and the like can be used. Moreover, from the viewpoint of enabling use even under heating conditions by microwave irradiation, it is preferable to select an organic solvent having a boiling point of 170 ° C. or higher, more preferably in the range of 200 to 300 ° C. It is better to choose one. Specific examples of such an organic solvent include tetraethylene glycol, n-octyl ether, polyalphaolefin having a carbon number in the range of 20 to 40, and the like.
（ニッケル錯体溶液）
ニッケル錯体溶液中のニッケル錯体濃度は、例えば２〜１１質量％の範囲内とすることが好ましく、４〜８質量％の範囲内とすることがより好ましい。一段階の合成法では、ニッケル錯体濃度が１１質量％を超えると、反応性が低下するとともに、粒子径の制御が難しくなる。
(Nickel complex solution)
The nickel complex concentration in the nickel complex solution is preferably in the range of 2 to 11% by mass, for example, and more preferably in the range of 4 to 8% by mass. In the one-step synthesis method, when the nickel complex concentration exceeds 11% by mass, the reactivity is lowered and it is difficult to control the particle size.
２価のニッケルイオンは配位子置換活性種として知られており、形成する錯体の配位子は温度、濃度によって容易に配位子交換により錯形成が変化する可能性がある。例えばカルボン酸ニッケルおよび脂肪族１級モノアミンの混合物を加熱して反応液を得る工程において、用いるアミンの炭素鎖長等の立体障害を考慮すると、例えば、カルボン酸イオンが二座配位または単座配位のいずれかで配位する可能性があり、さらにアミンの濃度が大過剰の場合は外圏にカルボン酸イオンが存在する構造をとる可能性がある。目的とする反応温度（還元温度）において均一溶液とするには、配位子のうち少なくとも一箇所は脂肪族１級モノアミンが配位している必要がある。その状態をとるには、脂肪族１級モノアミンが過剰に反応溶液内に存在している必要があり、少なくともニッケルイオン１ｍｏｌに対し２ｍｏｌ以上存在していることが好ましく、２．２ｍｏｌ以上存在していることがより好ましい。また、脂肪族１級モノアミンの量の上限は特にはないが、例えば生産性の観点からは、ニッケルイオン１ｍｏｌに対して２０ｍｏｌ以下とすることが好ましく、４ｍｏｌ以下とすることがより好ましい。つまり、脂肪族１級モノアミンの量は、ニッケルイオン１ｍｏｌに対して２〜２０ｍｏｌの範囲内が好ましく、２〜４ｍｏｌの範囲内がより好ましく、２．２〜４ｍｏｌの範囲内が最も好ましい。 A divalent nickel ion is known as a ligand-substituted active species, and the ligand of the complex to be formed may easily change in complex formation by ligand exchange depending on temperature and concentration. For example, in the step of obtaining a reaction liquid by heating a mixture of nickel carboxylate and aliphatic primary monoamine, considering steric hindrance such as the carbon chain length of the amine used, for example, the carboxylate ion is bidentate or monodentate. There is a possibility of coordination at any of the positions. Furthermore, when the amine concentration is excessively large, there is a possibility that a carboxylate ion is present in the outer sphere. In order to obtain a uniform solution at the intended reaction temperature (reduction temperature), at least one of the ligands must be coordinated with an aliphatic primary monoamine. In order to take this state, it is necessary that the aliphatic primary monoamine is excessively present in the reaction solution, and it is preferable that at least 2 mol per 1 mol of nickel ions is present, and 2.2 mol or more exist. More preferably. The upper limit of the amount of the aliphatic primary monoamine is not particularly limited. For example, from the viewpoint of productivity, the amount is preferably 20 mol or less, more preferably 4 mol or less with respect to 1 mol of nickel ions. That is, the amount of the aliphatic primary monoamine is preferably in the range of 2 to 20 mol, more preferably in the range of 2 to 4 mol, and most preferably in the range of 2.2 to 4 mol with respect to 1 mol of nickel ions.
（錯形成反応）
錯形成反応は室温においても進行させることができるが、反応を確実かつより効率的に行うために、１００℃以上の温度で加熱を行うことが好ましい。この加熱は、カルボン酸ニッケルとして、例えば酢酸ニッケル４水和物のようなカルボン酸ニッケルの水和物を用いた場合に特に有利である。加熱温度は、好ましくは１００℃を超える温度とし、より好ましくは１０５℃以上の温度とすることで、カルボン酸ニッケルに配位した配位水と脂肪族１級モノアミンとの配位子置換反応が効率よく行われ、この錯体配位子としての水分子を解離させることができ、更にその水を系外に出すことができるので効率よく錯体を形成させることができる。例えば、酢酸ニッケル４水和物は、室温では２個の配位水と２座配位子である２個の酢酸イオン、外圏に２つの水分子が存在した錯体構造をとっているため、この２つの配位水と脂肪族１級モノアミンの配位子置換により効率よく錯形成させるには、１００℃より高い温度で加熱することでこの錯体配位子としての水分子を解離させることが好ましい。また、加熱温度は、後に続く還元の過程と確実に分離し、錯形成反応を完結させるという観点から、１７５℃以下が好ましい。錯形成反応での加熱温度が高すぎると、ニッケル錯体の生成とニッケル(０価)への還元反応が同時に進行し、新たにニッケルの核が発生してしまうことで、粒子径の分布が狭い第１のニッケル微粒子１０の生成が困難となるおそれがある。従って、錯形成反応のための加熱温度は、例えば１０５℃〜１７５℃の範囲内が好ましく、より好ましくは、１２５〜１６０℃の範囲内である。
(Complex formation reaction)
Although the complexing reaction can proceed even at room temperature, it is preferable to perform heating at a temperature of 100 ° C. or higher in order to perform the reaction reliably and more efficiently. This heating is particularly advantageous when a nickel carboxylate hydrate such as nickel acetate tetrahydrate is used as the nickel carboxylate. The heating temperature is preferably a temperature exceeding 100 ° C., more preferably a temperature of 105 ° C. or more, so that the ligand substitution reaction between the coordinated water coordinated with nickel carboxylate and the aliphatic primary monoamine is performed. This is carried out efficiently, so that the water molecule as the complex ligand can be dissociated, and further, the water can be discharged out of the system, so that the complex can be formed efficiently. For example, nickel acetate tetrahydrate has a complex structure in which two coordinated water, two acetate ions that are bidentate ligands, and two water molecules exist in the outer sphere at room temperature. In order to efficiently form a complex by ligand substitution of these two coordinated water and aliphatic primary monoamine, the water molecule as the complex ligand can be dissociated by heating at a temperature higher than 100 ° C. preferable. The heating temperature is preferably 175 ° C. or lower from the viewpoint of reliably separating from the subsequent reduction process and completing the complex formation reaction. If the heating temperature in the complex formation reaction is too high, the formation of nickel complex and the reduction reaction to nickel (zero valence) proceed simultaneously, and new nickel nuclei are generated, resulting in a narrow distribution of particle size. There is a possibility that the generation of the first nickel fine particles 10 may be difficult. Therefore, the heating temperature for the complex formation reaction is preferably in the range of 105 ° C. to 175 ° C., for example, and more preferably in the range of 125 to 160 ° C.
加熱時間は、加熱温度や、各原料の含有量に応じて適宜決定することができるが、錯形成反応を確実に完結させるという観点から、１５分以上とすることが好ましい。加熱時間の上限は特にないが、長時間加熱することは、エネルギー消費及び工程時間を節約する観点から無駄である。加熱の方法は、特に制限されず、例えばオイルバスなどの熱媒体による加熱であっても、マイクロ波照射による加熱であってもよいが、マイクロ波照射による加熱が好ましい。マイクロ波照射による加熱は、混合液内の均一加熱を可能とし、かつエネルギーをニッケルイオンに直接与えることができるため、急速加熱を行なうことができる。マイクロ波の使用波長は、特に限定するものではなく、例えば２．４５ＧＨｚである。 The heating time can be appropriately determined according to the heating temperature and the content of each raw material, but is preferably 15 minutes or longer from the viewpoint of reliably completing the complex formation reaction. Although there is no upper limit on the heating time, heating for a long time is useless from the viewpoint of saving energy consumption and process time. The heating method is not particularly limited, and for example, heating by a heat medium such as an oil bath or heating by microwave irradiation may be used, but heating by microwave irradiation is preferable. Heating by microwave irradiation enables uniform heating in the mixed solution, and energy can be directly applied to nickel ions, so that rapid heating can be performed. The use wavelength of the microwave is not particularly limited and is, for example, 2.45 GHz.
カルボン酸ニッケルと脂肪族１級モノアミンとの錯形成反応は、カルボン酸ニッケルと脂肪族１級モノアミンを混合して得られる溶液を加熱したときに、溶液の色の変化によって確認することができる。また、この錯形成反応は、例えば紫外・可視吸収スペクトル測定装置を用いて、３００ｎｍ〜７５０ｎｍの波長領域において観測される吸収スペクトルの吸収極大の波長を測定し、原料の極大吸収波長（例えば酢酸ニッケル四水和物ではその極大吸収波長は７１０ｎｍである。）に対する錯化反応液のシフトを観測することによって確認することができる。 A complex formation reaction between nickel carboxylate and an aliphatic primary monoamine can be confirmed by a change in the color of the solution when a solution obtained by mixing nickel carboxylate and an aliphatic primary monoamine is heated. In addition, this complex formation reaction is carried out by measuring the absorption maximum wavelength of the absorption spectrum observed in the wavelength region of 300 nm to 750 nm using, for example, an ultraviolet / visible absorption spectrum measuring apparatus, and measuring the maximum absorption wavelength of the raw material (for example, nickel acetate). It can be confirmed by observing the shift of the complexing reaction solution with respect to tetrahydrate.
（加熱還元）
次に、得られたニッケル錯体溶液中、又は混合液中のニッケルイオンを加熱還元し、第１のニッケル微粒子１０に成長させる。この場合、種粒子を使用することが好ましく、後述する工程ｂで得られる第２のニッケル微粒子２０を、工程ａにおける種粒子として用いることがより好ましい。種粒子を用いることによって、一段階の合成法に比べ、均一な粒子径を有する第１のニッケル微粒子１０を製造できる。また、工程ｂで得られる第２のニッケル微粒子２０を種粒子として所定量使用することによって、第１のニッケル微粒子１０中に所望の量の銅元素を含有させることができる。
(Heat reduction)
Next, nickel ions in the obtained nickel complex solution or in the mixed solution are heated and reduced to grow into first nickel fine particles 10. In this case, it is preferable to use seed particles, and it is more preferable to use the second nickel fine particles 20 obtained in step b described later as seed particles in step a. By using the seed particles, the first nickel fine particles 10 having a uniform particle diameter can be produced as compared with the one-step synthesis method. Further, by using a predetermined amount of the second nickel fine particles 20 obtained in step b as seed particles, a desired amount of copper element can be contained in the first nickel fine particles 10.
ここで、種粒子を用いる場合は、種粒子と、ニッケル錯体溶液とを混合して混合液を得る。種粒子又は種粒子を含むスラリーを、ニッケル錯体溶液に添加してもよいし、種粒子を含むスラリーに、ニッケル錯体溶液を添加してもよい。混合されたニッケル錯体は、新たな核の形成には利用されず、種粒子から第１のニッケル微粒子１０への成長に利用される。つまり、混合液中のニッケル錯体の濃度が、核形成の臨界濃度を超えない限り、ニッケル錯体は粒子成長にのみ利用される。従って、目的とする粒子径の第１のニッケル微粒子１０を得るためのニッケル錯体の量は、種粒子の粒子径に基づき、計算上、算出することができる。 Here, when using seed particles, the seed particles and the nickel complex solution are mixed to obtain a mixed solution. The seed particles or the slurry containing the seed particles may be added to the nickel complex solution, or the nickel complex solution may be added to the slurry containing the seed particles. The mixed nickel complex is not used for the formation of new nuclei, but is used for the growth from the seed particles to the first nickel fine particles 10. That is, as long as the concentration of the nickel complex in the mixed solution does not exceed the critical concentration for nucleation, the nickel complex is used only for particle growth. Accordingly, the amount of the nickel complex for obtaining the first nickel fine particles 10 having a target particle diameter can be calculated based on the particle diameter of the seed particles.
種粒子としては、例えばニッケル元素に対する銅元素の含有割合が３質量％以上４０質量％以下の範囲内のものを用いることが好ましい。種粒子におけるニッケル元素に対する銅元素の含有量が３質量％未満であると、銅の核材としての効果が低下し、微細な球状で粒度分布が均一な種粒子を作りにくくなり、また、成長したニッケル微粒子の磁性を抑制する効果が十分に得られず、凝集が生じやすくなる傾向がある。一方、種粒子における銅元素の含有量が４０質量％を超えると、銅の核材としての効果が飽和し、微細な種粒子を作る為の効果は得にくく、種粒子の段階で表面が酸化しやすくなる。また、金属として、ニッケル及び銅に加え、これら以外のものを用いる場合、例えば、銀などの異種金属によるマイグレーションによるショートや静電容量の低下などの製品不良を防止する観点から、ニッケル及び銅以外の金属元素の含有量を０．０１質量％以上２質量％以下の範囲内とすることが好ましい。このような種粒子を用いる場合は、混合液中の種粒子が核として第１のニッケル微粒子１０が成長するとともに、第１のニッケル微粒子１０中で、銅原子を拡散させることができる。 As the seed particles, it is preferable to use, for example, those in which the content ratio of the copper element to the nickel element is in the range of 3% by mass to 40% by mass. If the content of copper element relative to nickel element in the seed particles is less than 3% by mass, the effect of copper as a core material will be reduced, making it difficult to produce seed particles with a fine spherical shape and uniform particle size distribution. The effect of suppressing the magnetism of the nickel fine particles is not sufficiently obtained, and aggregation tends to occur. On the other hand, if the content of the copper element in the seed particles exceeds 40% by mass, the effect as a copper core material is saturated, and it is difficult to obtain the effect for producing fine seed particles, and the surface is oxidized at the seed particle stage. It becomes easy to do. In addition to nickel and copper as metals, other than nickel and copper, for example, other than nickel and copper, from the viewpoint of preventing product defects such as short-circuiting due to migration of different metals such as silver and reduction in capacitance. The content of the metal element is preferably in the range of 0.01% by mass to 2% by mass. When such seed particles are used, the first nickel fine particles 10 grow using the seed particles in the mixed solution as nuclei, and copper atoms can be diffused in the first nickel fine particles 10.
加熱方法は、特に制限されず、例えばオイルバスなどの熱媒体による加熱であってもよいが、マイクロ波照射による加熱が好ましい。マイクロ波照射によるニッケル錯体の加熱は、ニッケル錯体の均一加熱を可能とし、かつエネルギーをニッケル錯体に直接与えることができるため、急速加熱を行なうことができる。これにより、反応液全体を所望の温度に均一にすることができ、ニッケル錯体（又はニッケルイオン）の還元と成長を溶液全体において同時に生じさせ、結果として粒子径分布の狭い単分散な粒子を短時間で容易に製造することができる。マイクロ波の使用波長は、特に限定するものではなく、例えば２．４５ＧＨｚである。 The heating method is not particularly limited, and for example, heating by a heat medium such as an oil bath may be used, but heating by microwave irradiation is preferable. Heating of the nickel complex by microwave irradiation enables uniform heating of the nickel complex and energy can be directly applied to the nickel complex, so that rapid heating can be performed. As a result, the entire reaction solution can be made uniform at a desired temperature, and reduction and growth of the nickel complex (or nickel ions) can occur simultaneously in the entire solution. As a result, monodisperse particles having a narrow particle size distribution can be shortened. It can be manufactured easily in time. The use wavelength of the microwave is not particularly limited and is, for example, 2.45 GHz.
加熱還元の温度は、得られる第１のニッケル微粒子１０の形状のばらつきを抑制するという観点から、好ましくは１７０℃以上、より好ましくは１８０℃以上とすることがよい。また、加熱温度が低すぎると、ニッケル錯体からニッケル(０価)への還元反応速度が遅くなり、金属ニッケルの成長が遅くなる傾向がある。加熱温度の上限は特にないが、処理を能率的に行う観点からは例えば２７０℃以下とすることが好適である。また、２７０℃を超えると炭化反応が進行して炭化ニッケルが生成しやすくなるので、好ましくない。 The temperature of the heat reduction is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, from the viewpoint of suppressing variation in the shape of the obtained first nickel fine particles 10. On the other hand, if the heating temperature is too low, the reduction reaction rate from the nickel complex to nickel (zero valence) tends to be slow, and the growth of metallic nickel tends to be slow. The upper limit of the heating temperature is not particularly limited, but is preferably set to 270 ° C. or less, for example, from the viewpoint of efficiently performing the treatment. Moreover, when it exceeds 270 degreeC, since carbonization reaction will advance and it will become easy to produce | generate nickel carbide, it is not preferable.
加熱還元時の熱処理によって、加熱還元と同時に第１のニッケル微粒子１０中の銅元素を拡散させることができる。 By the heat treatment during the heat reduction, the copper element in the first nickel fine particles 10 can be diffused simultaneously with the heat reduction.
以上のようにして、第１のニッケル微粒子１０を含有するスラリーを得ることが出来る。なお、工程ａでは、第１のニッケル微粒子１０を含有するスラリーを、例えば、静置分離し、上澄み液を取り除いた後、適当な溶媒を用いて洗浄し、乾燥することで第１のニッケル微粒子１０を分取してもよい。 As described above, a slurry containing the first nickel fine particles 10 can be obtained. In step a, for example, the slurry containing the first nickel fine particles 10 is statically separated, and after removing the supernatant, the first nickel fine particles are washed with an appropriate solvent and dried. 10 may be collected.
［工程ｂ］
本工程は、走査型電子顕微鏡観察による平均粒子径Ｄ５０が５ｎｍ以上４０ｎｍ未満の範囲内である第２のニッケル微粒子２０を準備する工程である。なお、第２のニッケル微粒子２０は、工程ａにおいて、第１のニッケル微粒子１０の成長の核（種粒子）としても利用できるものである。
[Step b]
This step is a step of preparing second nickel fine particles 20 having an average particle diameter D50 by scanning electron microscope observation in the range of 5 nm or more and less than 40 nm. The second nickel fine particles 20 can also be used as nuclei (seed particles) for the growth of the first nickel fine particles 10 in step a.
工程ｂでは、少なくともカルボン酸ニッケルを含む金属塩と、脂肪族１級モノアミンと、を混合し、加熱することによって金属塩を有機アミンに溶解させたニッケル錯体溶液を準備し、このニッケル錯体溶液を湿式加熱還元することによって第２のニッケル微粒子２０を製造することができる。例えば、ニッケル塩及び銅塩を含む原料から、有機アミンの存在下で加熱による湿式還元によって製造することが好ましい。この場合、銅とニッケルとの標準電極電位の相違から、まず、銅粒子が形成され、次に、銅粒子の表面にニッケル被膜が形成されることによって、第２のニッケル微粒子２０が得られる。 In step b, a metal salt containing at least nickel carboxylate and an aliphatic primary monoamine are mixed and heated to prepare a nickel complex solution in which the metal salt is dissolved in an organic amine. The second nickel fine particles 20 can be produced by wet heat reduction. For example, it is preferable to produce from a raw material containing a nickel salt and a copper salt by wet reduction by heating in the presence of an organic amine. In this case, due to the difference in standard electrode potential between copper and nickel, first, copper particles are formed, and then a nickel coating is formed on the surface of the copper particles, whereby the second nickel fine particles 20 are obtained.
（銅塩）
銅塩としては、例えばカルボン酸銅を用いることが好ましい。また、カルボン酸銅としては、例えば、還元過程での解離温度（分解温度）が比較的低いギ酸銅、酢酸銅などを用いることが好ましい。また、カルボン酸銅は、無水物であってもよく、水和物であってもよい。銅塩を配合することによって、第２のニッケル微粒子２０の形成を促進できるとともに、第２のニッケル微粒子２０の粒子径の制御が容易になる。
(Copper salt)
As the copper salt, for example, copper carboxylate is preferably used. Moreover, as copper carboxylate, it is preferable to use copper formate, copper acetate, etc. whose dissociation temperature (decomposition temperature) in a reduction process is comparatively low, for example. The copper carboxylate may be an anhydride or a hydrate. By blending the copper salt, the formation of the second nickel fine particles 20 can be promoted, and the particle diameter of the second nickel fine particles 20 can be easily controlled.
（ニッケル塩）
ニッケル塩としては、例えばカルボン酸ニッケルを用いることが好ましい。また、カルボン酸ニッケルとしては、例えば、還元過程での解離温度（分解温度）が比較的低いギ酸ニッケル、酢酸ニッケルなどを用いることが好ましい。カルボン酸ニッケルは、無水物であってもよく、また水和物であってもよい。なお、カルボン酸ニッケルに代えて、塩化ニッケル、硝酸ニッケル、硫酸ニッケル、炭酸ニッケル、水酸化ニッケル等の無機塩を用いることも考えられるが、無機塩の場合、解離(分解)が高温であるため、還元過程で高温での加熱が必要であり好ましくない。また、Ｎｉ（ａｃａｃ）２（β−ジケトナト錯体)、ステアリン酸イオン等の有機配位子により構成されるニッケル塩を用いることも考えられるが、これらのニッケル塩を用いると、原料コストが高くなり好ましくない。
(Nickel salt)
For example, nickel carboxylate is preferably used as the nickel salt. Moreover, as nickel carboxylate, it is preferable to use nickel formate, nickel acetate, etc. whose dissociation temperature (decomposition temperature) in a reduction process is comparatively low, for example. The nickel carboxylate may be an anhydride or a hydrate. In addition, it is possible to use inorganic salts such as nickel chloride, nickel nitrate, nickel sulfate, nickel carbonate, nickel hydroxide instead of nickel carboxylate, but in the case of inorganic salts, dissociation (decomposition) is high temperature. In the reduction process, heating at a high temperature is necessary, which is not preferable. It is also possible to use nickel salts composed of organic ligands such as Ni (acac) 2 (β-diketonato complex) and stearate ions, but using these nickel salts increases the cost of raw materials. It is not preferable.
なお、第２のニッケル微粒子２０は、ニッケル及び銅以外の金属を含有していてもよい。その場合、第２のニッケル微粒子２０の調製に際して、例えば、銀、金、白金及びパラジウムから選ばれる１種以上の金属の塩を使用してもよい。これらの金属の塩としては、例えば酢酸パラジウムなどのカルボン酸塩、硝酸銀などの硝酸塩、塩化金酸、塩化白金酸などの塩化物などを用いることが好ましい。金属塩は、無水物であってもよく、また水和物であってもよい。 In addition, the 2nd nickel fine particle 20 may contain metals other than nickel and copper. In that case, when preparing the second nickel fine particles 20, for example, a salt of one or more metals selected from silver, gold, platinum and palladium may be used. As these metal salts, for example, carboxylates such as palladium acetate, nitrates such as silver nitrate, and chlorides such as chloroauric acid and chloroplatinic acid are preferably used. The metal salt may be an anhydride or a hydrate.
第２のニッケル微粒子２０において、銅を含有する場合、銅元素の含有量は、例えば３質量％以上４０質量％以下の範囲内とすることが好ましい。第２のニッケル微粒子２０における銅元素の含有量が３質量％未満であると、銅の核材としての効果が低下し、微細な球状で粒度分布が均一な第２のニッケル微粒子２０を作りにくくなり、また、成長したニッケル微粒子の磁性を抑制する効果が十分に得られず、凝集が生じやすくなる傾向がある。一方、第２のニッケル微粒子２０における銅元素の含有量が４０質量％を超えると、銅の核材としての効果が飽和し、微細な第２のニッケル微粒子２０を作る為の効果は得にくく、第２のニッケル微粒子２０の段階で表面が酸化しやすくなる。また、金属として、銅以外のものを用いる場合、例えば、銀などのニッケル以外の異種金属によるマイグレーションによるショートや静電容量の低下などの製品不良を防止する観点から、銅以外の金属元素の含有量を０．０１質量％以上２質量％以下の範囲内とすることが好ましい。 When the second nickel fine particles 20 contain copper, the content of the copper element is preferably in the range of 3% by mass to 40% by mass, for example. When the content of the copper element in the second nickel fine particle 20 is less than 3% by mass, the effect as a copper core material is reduced, and it is difficult to form the second nickel fine particle 20 having a fine spherical shape and a uniform particle size distribution. In addition, the effect of suppressing the magnetism of the grown nickel fine particles cannot be sufficiently obtained and aggregation tends to occur. On the other hand, if the content of the copper element in the second nickel fine particles 20 exceeds 40% by mass, the effect as a copper core material is saturated, and it is difficult to obtain the effect for making the fine second nickel fine particles 20, The surface is easily oxidized at the stage of the second nickel fine particles 20. In addition, when a metal other than copper is used as the metal, for example, from the viewpoint of preventing product defects such as short-circuiting due to migration by a dissimilar metal other than nickel such as silver and a decrease in capacitance, the inclusion of metal elements other than copper The amount is preferably in the range of 0.01% by mass to 2% by mass.
（有機アミン）
有機アミンは、ニッケルイオンとの錯体を形成できるものであれば、特に限定されず、常温で固体又は液体のものが使用できる。ここで、常温とは、２０℃±１５℃をいう。常温で液体の有機アミンは、ニッケル錯体を形成する際の有機溶媒としても機能する。なお、常温で固体の有機アミンであっても、加熱によって液体であるか、又は有機溶媒を用いて溶解するものであれば、特に問題はない。
(Organic amine)
The organic amine is not particularly limited as long as it can form a complex with nickel ions, and can be solid or liquid at room temperature. Here, room temperature means 20 ° C. ± 15 ° C. The organic amine that is liquid at room temperature also functions as an organic solvent for forming the nickel complex. In addition, even if it is a solid organic amine at normal temperature, if it is a liquid by heating or melt | dissolves using an organic solvent, there will be no problem in particular.
有機アミンとしては、脂肪族１級モノアミンを用いることが好ましい。一方、２級アミンは立体障害が大きいため、ニッケル錯体の良好な形成を阻害するおそれがあり、３級アミンはニッケルイオンの還元能を有しないため、いずれも使用できない。また、ジアミンは、金属イオンの中でも特にニッケルイオンと形成した錯体の安定性が高く、その還元温度は高くなるため反応性が非常に低く、生成するニッケル微粒子に歪が生じやすくなるため好ましくない。 As the organic amine, an aliphatic primary monoamine is preferably used. On the other hand, secondary amines have great steric hindrance and may hinder good formation of nickel complexes, and tertiary amines cannot be used because they do not have the ability to reduce nickel ions. Also, diamines are not preferred because of the high stability of complexes formed with nickel ions among metal ions, and the reduction temperature is high, so that the reactivity is very low and the resulting nickel fine particles are likely to be distorted.
脂肪族１級モノアミンは、例えばその炭素鎖の長さを調整することによって生成する第２のニッケル微粒子２０の粒径を制御することができる。第２のニッケル微粒子２０の粒径を制御する観点から、脂肪族１級モノアミンは、その炭素数が６〜２０程度のものから選択して用いることが好適である。炭素数が多いほど得られる第２のニッケル微粒子２０の粒径が小さくなる。このようなアミンとして、例えばオクチルアミン、トリオクチルアミン、ジオクチルアミン、ヘキサデシルアミン、ドデシルアミン、テトラデシルアミン、ステアリルアミン、オレイルアミン、ミリスチルアミン、ラウリルアミン等を挙げることができる。 The aliphatic primary monoamine can control the particle diameter of the second nickel fine particles 20 produced, for example, by adjusting the length of the carbon chain. From the viewpoint of controlling the particle diameter of the second nickel fine particles 20, the aliphatic primary monoamine is preferably selected from those having about 6 to 20 carbon atoms. The larger the number of carbon atoms, the smaller the particle diameter of the obtained second nickel fine particles 20. Examples of such amines include octylamine, trioctylamine, dioctylamine, hexadecylamine, dodecylamine, tetradecylamine, stearylamine, oleylamine, myristylamine, and laurylamine.
脂肪族１級モノアミンは、第２のニッケル微粒子２０の生成時に表面修飾剤として機能するため、脂肪族１級モノアミンの除去後においても二次凝集を抑制できる。また、脂肪族１級モノアミンは、還元反応後の生成した第２のニッケル微粒子２０の固体成分と溶剤又は未反応の脂肪族１級モノアミン等を分離する洗浄工程における処理操作の容易性の観点からも好ましい。更に、脂肪族１級モノアミンは、ニッケル錯体を還元して第２のニッケル微粒子２０を得るときの反応制御の容易性の観点からは還元温度より沸点が高いものが好ましい。すなわち、脂肪族１級モノアミンは、沸点が１８０℃以上のものが好ましく、２００℃以上のものがより好ましい。また、脂肪族１級モノアミンは、炭素数が９以上であることが好ましい。ここで、例えば炭素数が９である脂肪族１級モノアミンのＣ９Ｈ２１Ｎ(ノニルアミン)の沸点は２０１℃である。 Since the aliphatic primary monoamine functions as a surface modifier when the second nickel fine particles 20 are produced, secondary aggregation can be suppressed even after the removal of the aliphatic primary monoamine. In addition, the aliphatic primary monoamine is used from the viewpoint of ease of processing operation in the washing step of separating the solid component of the second nickel fine particles 20 produced after the reduction reaction from the solvent or the unreacted aliphatic primary monoamine. Is also preferable. Further, the aliphatic primary monoamine is preferably one having a boiling point higher than the reduction temperature from the viewpoint of easy control of the reaction when the nickel complex is reduced to obtain the second nickel fine particles 20. That is, the aliphatic primary monoamine has a boiling point of preferably 180 ° C. or higher, more preferably 200 ° C. or higher. The aliphatic primary monoamine preferably has 9 or more carbon atoms. Here, for example, the boiling point of C 9 H 21 N (nonylamine), which is an aliphatic primary monoamine having 9 carbon atoms, is 201 ° C.
脂肪族１級モノアミンは、還元反応後の生成した第２のニッケル微粒子２０の固体成分と溶剤または未反応の脂肪族１級モノアミン等を分離する洗浄工程における処理操作の容易性の観点から、室温で液体のものが好ましい。更に、脂肪族１級モノアミンは、銅錯体を還元して第２のニッケル微粒子２０を得るときの反応制御の容易性の観点から、還元温度より沸点が高いものが好ましい。脂肪族１級モノアミンの量は、金属イオン（ニッケルイオン及び銅イオンの合計）１ｍｏｌに対して５ｍｏｌ以上用いることが好ましく、８ｍｏｌ以上用いることがより好ましい。脂肪族１級モノアミンの量が５ｍｏｌ未満では、得られるニッケル微粒子の粒子径の制御が困難となり、粒子径がばらつきやすくなる。また、脂肪族１級モノアミンの量の上限は特にはないが、例えば生産性の観点からは、金属イオン１ｍｏｌに対して２０ｍｏｌ以下とすることが好ましく、１５ｍｏｌ以下とすることがより好ましい。つまり、脂肪族１級モノアミンの量は、金属イオン１ｍｏｌに対して５〜２０ｍｏｌの範囲内が好ましく、８〜１５ｍｏｌの範囲内がより好ましい。 The aliphatic primary monoamine is used at room temperature from the viewpoint of ease of processing operation in the washing step of separating the solid component of the second nickel fine particles 20 produced after the reduction reaction from the solvent or the unreacted aliphatic primary monoamine. And liquid is preferable. Further, the aliphatic primary monoamine is preferably one having a boiling point higher than the reduction temperature from the viewpoint of easy reaction control when the second nickel fine particles 20 are obtained by reducing the copper complex. The amount of the aliphatic primary monoamine is preferably 5 mol or more, more preferably 8 mol or more, based on 1 mol of metal ions (total of nickel ions and copper ions). When the amount of the aliphatic primary monoamine is less than 5 mol, it is difficult to control the particle diameter of the obtained nickel fine particles, and the particle diameter tends to vary. The upper limit of the amount of the aliphatic primary monoamine is not particularly limited. However, for example, from the viewpoint of productivity, the amount is preferably 20 mol or less, more preferably 15 mol or less with respect to 1 mol of the metal ion. That is, the amount of the aliphatic primary monoamine is preferably in the range of 5 to 20 mol and more preferably in the range of 8 to 15 mol with respect to 1 mol of the metal ion.
（有機溶媒）
脂肪族１級モノアミンは、有機溶媒として反応を進行させることができるが、均一溶液での反応をより効率的に進行させるために、第２のニッケル微粒子２０の調製において、脂肪族１級モノアミンとは別の有機溶媒を新たに添加してもよい。使用できる有機溶媒としては、脂肪族１級モノアミンと、ニッケルイオン、銅イオンなどの金属イオンとの錯形成を阻害しないものであれば、特に限定するものではなく、例えば炭素数４〜３０のエーテル系有機溶媒、炭素数７〜３０の飽和又は不飽和の炭化水素系有機溶媒、炭素数８〜１８のアルコール系有機溶媒等を使用することができる。また、マイクロ波照射による加熱条件下でも使用を可能とする観点から、使用する有機溶媒は、沸点が１７０℃以上のものを選択することが好ましく、より好ましくは２００〜３００℃の範囲内にあるものを選択することがよい。このような有機溶媒の具体例としては、例えばテトラエチレングリコール、ｎ−オクチルエーテル、炭素数が２０〜４０の範囲内にあるポリアルファオレフィン等が挙げられる。
(Organic solvent)
Although the aliphatic primary monoamine can proceed as an organic solvent, in order to proceed the reaction in a homogeneous solution more efficiently, in the preparation of the second nickel fine particles 20, an aliphatic primary monoamine and Another organic solvent may be newly added. The organic solvent that can be used is not particularly limited as long as it does not inhibit complex formation between an aliphatic primary monoamine and a metal ion such as nickel ion or copper ion. For example, an ether having 4 to 30 carbon atoms. An organic organic solvent, a saturated or unsaturated hydrocarbon organic solvent having 7 to 30 carbon atoms, an alcohol organic solvent having 8 to 18 carbon atoms, and the like can be used. Moreover, from the viewpoint of enabling use even under heating conditions by microwave irradiation, it is preferable to select an organic solvent having a boiling point of 170 ° C. or higher, more preferably in the range of 200 to 300 ° C. It is better to choose one. Specific examples of such an organic solvent include tetraethylene glycol, n-octyl ether, polyalphaolefin having a carbon number in the range of 20 to 40, and the like.
（加熱還元）
第２のニッケル微粒子２０を形成するための加熱還元方法は、特に制限されず、例えばオイルバスなどの熱媒体による加熱であっても、マイクロ波照射による加熱であってもよいが、均一、かつ急速な加熱が可能なマイクロ波照射による加熱が好ましい。マイクロ波の使用波長は、特に限定するものではなく、例えば２．４５ＧＨｚである。
(Heat reduction)
The heating reduction method for forming the second nickel fine particles 20 is not particularly limited, and for example, heating by a heat medium such as an oil bath or heating by microwave irradiation may be used. Heating by microwave irradiation capable of rapid heating is preferable. The use wavelength of the microwave is not particularly limited and is, for example, 2.45 GHz.
第２のニッケル微粒子２０を形成するための加熱温度は、第２のニッケル微粒子２０の形状のばらつきを抑制するという観点から、好ましくは１７０℃以上、より好ましくは１８０℃以上とすることがよい。加熱温度の上限は特にないが、処理を能率的に行う観点から、例えば２７０℃以下とすることが好適である。 The heating temperature for forming the second nickel fine particles 20 is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, from the viewpoint of suppressing variation in the shape of the second nickel fine particles 20. The upper limit of the heating temperature is not particularly limited, but is preferably set to 270 ° C. or less, for example, from the viewpoint of efficiently performing the treatment.
以上のようにして、第２のニッケル微粒子２０を含有するスラリーを得ることが出来る。なお、工程ｂでは、第２のニッケル微粒子２０を含有するスラリーを、例えば、静置分離し、上澄み液を取り除いた後、適当な溶媒を用いて洗浄し、乾燥することで第２のニッケル微粒子２０を分取してもよい。 As described above, a slurry containing the second nickel fine particles 20 can be obtained. In step b, the slurry containing the second nickel fine particles 20 is, for example, left and separated, and after removing the supernatant liquid, the slurry is washed with an appropriate solvent and dried to obtain the second nickel fine particles. 20 may be collected.
工程ｃ（洗浄工程）：
工程ｃは、第２のニッケル微粒子２０を溶剤で洗浄する工程である。本工程で洗浄に用いる溶剤としては、例えばトルエン、キシレン等の芳香族系溶媒、メタノール、エタノール、イソプロピルアルコール、ブタノール、オクタノールなどの１級またはエチレングリコール、テトラエチレングリコールなどの多価アルコールなどのアルコール系溶媒、ヘキサン、デカン、テトラリンなどの炭化水素系溶媒またはエーテル類やエステル類系溶媒などの有機溶剤を用いることができる。第２のニッケル微粒子２０を洗浄することによって、第２のニッケル微粒子２０の表面に付着した反応原料や反応副生物などを除去できるため、凝集が抑制される。
Step c (cleaning step):
Step c is a step of washing the second nickel fine particles 20 with a solvent. Examples of the solvent used for washing in this step include aromatic solvents such as toluene and xylene, alcohols such as primary solvents such as methanol, ethanol, isopropyl alcohol, butanol and octanol, and polyhydric alcohols such as ethylene glycol and tetraethylene glycol. An organic solvent such as a system solvent, a hydrocarbon solvent such as hexane, decane, or tetralin, or an ether or ester solvent can be used. By washing the second nickel fine particles 20, reaction raw materials and reaction byproducts attached to the surface of the second nickel fine particles 20 can be removed, and thus aggregation is suppressed.
本工程において、洗浄の方法は、例えばろ過、遠心分離、超音波、磁気分離、超臨界流体洗浄などを挙げることができる。これらの中でもろ過による洗浄が好ましく、第２のニッケル微粒子２０を含有するスラリーを、溶剤とともにフィルタでろ過することにより行うことがより好ましい。ここで用いるフィルタは、第２のニッケル微粒子２０の平均粒子径Ｄ５０Ｂに対して１０％以上小さな平均孔径を有するものを使用することが好ましい。フィルタの平均孔径が、第２のニッケル微粒子２０の平均粒子径Ｄ５０Ｂに対して非常に近い場合には、孔に粒子が入り込み閉塞して、洗浄が困難になる。例えば、第２のニッケル微粒子２０の平均粒子径Ｄ５０Ｂが５ｎｍであるときは、フィルタの平均孔径は４．５ｎｍ以下であることが好ましく、第２のニッケル微粒子２０の平均粒子径Ｄ５０Ｂが４０ｎｍであるときは、フィルタの平均孔径は３６ｎｍ以下であることが好ましい。洗浄に用いるフィルタの平均孔径を、第２のニッケル微粒子２０の平均粒子径Ｄ５０Ｂに対して１０％以上小さくすることによって、効率的なろ過が可能となる。一方、フィルタの平均孔径が小さ過ぎると、通過流量が極めて遅くなることから生産性が低下する。従って、本工程で用いるフィルタの平均孔径は、第２のニッケル微粒子２０の平均粒子径Ｄ５０Ｂに対して、１０％以上８０％以下の範囲内で小さいことが好ましく、２０％以上７０％以下の範囲内で小さいことがより好ましい。
フィルタの材質に制限はなく、例えば、セラミックス、プラスチックス、布、紙などが使用できる。好ましくは、耐溶剤性、耐久性、耐熱性、耐磨耗性に優れるセラミックスフィルタである。具体的には、アルミナ製又はジルコニア製のフィルタが好ましい。
In this step, examples of the washing method include filtration, centrifugation, ultrasonic waves, magnetic separation, and supercritical fluid washing. Among these, washing by filtration is preferable, and it is more preferable that the slurry containing the second nickel fine particles 20 is filtered by a filter together with a solvent. As used herein filter, it is preferable to use those having a small average pore diameter of 10% or more of the average particle diameter D50 B of the second nickel particles 20. The average pore diameter of the filter, when very close to the average particle diameter D50 B of the second nickel particle 20 is closed narrowing contains the particles in the hole, cleaning becomes difficult. For example, when the average particle diameter D50 B of the second nickel fine particles 20 is 5 nm, the average pore diameter of the filter is preferably 4.5 nm or less, and the average particle diameter D50 B of the second nickel fine particles 20 is 40 nm. When it is, it is preferable that the average hole diameter of a filter is 36 nm or less. The average pore size of the filter used for washing, by decreasing more than 10% relative to the average particle diameter D50 B of the second nickel particle 20, thereby enabling efficient filtration. On the other hand, if the average pore diameter of the filter is too small, the flow rate is extremely slow, which reduces productivity. Thus, the average pore size of the filter used in this step, the second for an average particle diameter D50 B nickel particle 20 is preferably smaller in the range of 10% to 80% or less, 70% less than 20% More preferably within the range.
There is no restriction | limiting in the material of a filter, For example, ceramics, plastics, cloth, paper etc. can be used. A ceramic filter excellent in solvent resistance, durability, heat resistance, and abrasion resistance is preferable. Specifically, an alumina or zirconia filter is preferred.
工程ｄ（混合工程）：
工程ｄは、工程ａで得られた第１のニッケル微粒子１０のスラリーと、工程ｂで得られ、工程ｃで洗浄された第２のニッケル微粒子２０とを混合する。なお、第１のニッケル微粒子１０は、別途、洗浄工程を設けて洗浄したものを使用してもよい。混合比率は、ニッケル微粒子含有組成物１００中の第１のニッケル微粒子１０と第２のニッケル微粒子２０の合計量に対し、第１のニッケル微粒子１０の含有量が７５〜９９質量％の範囲内、好ましくは８０〜９５質量％の範囲内であり、第２のニッケル微粒子２０の含有量が１〜２５質量％の範囲内、好ましくは５〜２０質量％の範囲内であることが好ましい。
Step d (mixing step):
In step d, the slurry of the first nickel fine particles 10 obtained in step a is mixed with the second nickel fine particles 20 obtained in step b and washed in step c. In addition, you may use the 1st nickel fine particle 10 which provided the washing | cleaning process separately and was washed. The mixing ratio is such that the content of the first nickel fine particles 10 is in the range of 75 to 99% by mass with respect to the total amount of the first nickel fine particles 10 and the second nickel fine particles 20 in the nickel fine particle-containing composition 100. Preferably, it is in the range of 80 to 95% by mass, and the content of the second nickel fine particles 20 is in the range of 1 to 25% by mass, preferably in the range of 5 to 20% by mass.
混合工程では、第１のニッケル微粒子１０と第２のニッケル微粒子２０とを均一な混合、分散状態とするために、例えば撹拌、衝撃混合、せん断混合等の操作を行うことが好ましい。 In the mixing step, it is preferable to perform operations such as stirring, impact mixing, and shear mixing in order to make the first nickel fine particles 10 and the second nickel fine particles 20 uniformly mixed and dispersed.
好ましい態様として、本混合工程は、工程ｃと同時に、又は工程ｃの後で引き続き、フィルタで第１のニッケル微粒子１０をろ過することによって行うことが可能である。つまり、第１のニッケル微粒子１０と第２のニッケル微粒子２０と溶剤を混合した状態で、工程ｃのフィルタによる洗浄を行ってもよいし、フィルタによる第２のニッケル微粒子２０の洗浄工程に引き続き、該フィルタに第１のニッケル微粒子１０と溶剤とを投入することによって、第１のニッケル微粒子１０と第２のニッケル微粒子２０とを混合してもよい。なお、別途、孔径の大きなフィルタを用いた洗浄や、遠心分離や磁器分離等の方法で第１のニッケル微粒子１０を洗浄しておき、洗浄後の第１のニッケル微粒子１０を、工程ｃのフィルタによる洗浄中、又は洗浄後の第２のニッケル微粒子２０に混合してもよい。 As a preferred embodiment, this mixing step can be performed by filtering the first nickel fine particles 10 with a filter simultaneously with step c or subsequently after step c. That is, in the state where the first nickel fine particles 10, the second nickel fine particles 20 and the solvent are mixed, the cleaning by the filter in the step c may be performed, or following the cleaning step of the second nickel fine particles 20 by the filter, The first nickel fine particles 10 and the second nickel fine particles 20 may be mixed by introducing the first nickel fine particles 10 and a solvent into the filter. Separately, the first nickel fine particles 10 are washed by a method such as washing using a filter having a large pore diameter, centrifugal separation, porcelain separation, and the like, and the first nickel fine particles 10 after washing are removed from the filter of step c. It may be mixed with the second nickel fine particles 20 during or after the cleaning.
以上のようにしてスラリー状態のニッケル微粒子含有組成物１００を製造することができるが、本実施の形態のニッケル微粒子含有組成物１００の製造方法は、上記工程ａ〜工程ｄ以外に、任意の工程を含むことが可能であり、例えば、以下の工程ｅなどを含むことができる。 Although the slurry-containing nickel fine particle-containing composition 100 can be produced as described above, the method for producing the nickel fine particle-containing composition 100 of the present embodiment is optional in addition to the above steps a to d. For example, the following step e and the like can be included.
工程ｅ（乾燥工程）：
本工程では、工程ｄで得られたスラリー状態のニッケル微粒子含有組成物１００を、例えば、静置分離し、上澄み液を取り除いた後、乾燥することで、乾燥状態のニッケル微粒子含有組成物１００が得られる。本工程で得られる乾燥後のニッケル微粒子含有組成物１００は粉末状をなしていてもよい。この場合、第１のニッケル微粒子１０と第２のニッケル微粒子２０が凝集して２次粒子を形成していてもよいが、上記のとおり、個々の２次粒子における第１のニッケル微粒子１０の含有比率が７５〜９９質量％であり、かつ第２のニッケル微粒子２０の含有比率が１〜２５質量％の範囲内であることが好ましい。
Step e (drying step):
In this step, the nickel fine particle-containing composition 100 in the slurry state obtained in the step d is, for example, statically separated, and after removing the supernatant liquid, the dried nickel fine particle-containing composition 100 is dried. can get. The dried nickel fine particle-containing composition 100 obtained in this step may be in the form of a powder. In this case, the first nickel fine particles 10 and the second nickel fine particles 20 may be aggregated to form secondary particles. However, as described above, the inclusion of the first nickel fine particles 10 in the individual secondary particles. It is preferable that the ratio is 75 to 99% by mass and the content ratio of the second nickel fine particles 20 is in the range of 1 to 25% by mass.
本実施の形態のニッケル微粒子含有組成物１００は、平均粒子径が異なり、粒度分布の小さな２種類のニッケル微粒子を混合しているため、粒子径分布のピークを少なくとも２つ持っており、配合量の多い大きな粒子（第１のニッケル微粒子１０）どうしの隙間を、配合量の少ない小さな粒子（第２のニッケル微粒子２０）によって埋めることができる。そのため、ニッケル微粒子含有組成物１００の密度は、単一ピークの粒子径分布を持つ同体積のニッケル微粒子に比べて高くなる。しかも、２種類のニッケル微粒子にそれぞれ銅元素が含まれている場合は、凝集の原因となるニッケル微粒子の磁性を弱め、分散性の向上に寄与するため、第２のニッケル微粒子２０が第１のニッケル微粒子１０の周囲に均等に配置されやすく、高密度な状態を取りやすい。従って、本実施の形態のニッケル微粒子含有組成物１００を用いることによって、例えば積層セラミックコンデンサの製造過程で、焼結時のデラミネーションやクラック等の欠陥の発生を防ぐことができる。このようなニッケル微粒子含有組成物１００は、積層セラミックコンデンサの内部電極の材料などの用途に好適に用いることができる。 Since the nickel fine particle-containing composition 100 of the present embodiment has two different kinds of nickel fine particles having a different average particle size and a small particle size distribution, it has at least two peaks in the particle size distribution. A gap between large particles (first nickel fine particles 10) with a large amount can be filled with small particles (second nickel fine particles 20) with a small blending amount. Therefore, the density of the nickel fine particle-containing composition 100 is higher than that of the same volume of nickel fine particles having a single peak particle size distribution. In addition, when each of the two types of nickel fine particles contains a copper element, the nickel fine particles 20 that cause aggregation are weakened and contribute to improvement in dispersibility. It is easy to arrange evenly around the nickel fine particles 10 and to take a high density state. Therefore, by using the nickel fine particle-containing composition 100 of the present embodiment, it is possible to prevent the occurrence of defects such as delamination and cracks during sintering, for example, in the process of manufacturing a multilayer ceramic capacitor. Such nickel fine particle-containing composition 100 can be suitably used for applications such as a material for internal electrodes of a multilayer ceramic capacitor.
また、通常、ニッケル微粒子は、平均粒子径が小さくなると焼結温度が低下するだけでなく、粒子の比表面積が大きくなることから、粒子表面の酸素量（及び有機物などの不純物）が多くなり、熱収縮量も大きくなる。これによって、例えばＭＬＣＣ製造時の焼結過程で、図２に示すように、第２のニッケル微粒子２０を加熱段階で速やかに溶融させ、第１のニッケル微粒子１０どうしの隙間を溶融物で埋め、全体の熱収縮を抑制することができる。本実施の形態においては、このような溶融温度の差を利用し、混合粒子の熱収縮率を小さくすることによって、内部電極層と誘電体層とのデラミネーションや内部電極層の膜切れを防止することが可能になる。 Further, usually, the nickel fine particles not only lower the sintering temperature when the average particle size decreases, but also increase the specific surface area of the particles, so the amount of oxygen on the particle surface (and impurities such as organic matter) increases, The amount of heat shrinkage also increases. Thereby, for example, in the sintering process at the time of MLCC production, as shown in FIG. 2, the second nickel fine particles 20 are rapidly melted in the heating stage, and the gap between the first nickel fine particles 10 is filled with the melt, The overall thermal contraction can be suppressed. In the present embodiment, by utilizing such a difference in melting temperature and reducing the thermal shrinkage rate of the mixed particles, delamination between the internal electrode layer and the dielectric layer and film breakage of the internal electrode layer are prevented. It becomes possible to do.
［積層セラミックコンデンサ用の内部電極］
本実施の形態の積層セラミックコンデンサ用の内部電極（以下、単に「内部電極」ともいう。）は、本実施の形態のニッケル微粒子含有組成物をペースト化し、セラミック基板上に印刷することで製造される。
前記ペースト化する際、有機ビヒクル、水系ビヒクル等の公知の粘度調整剤を混合させても良い。粘度調整剤を混合することで、前記ペーストに適度な流動性や揮発性が付与され、セラミック基板上に平滑な内部電極を形成することができる。
有機ビヒクルは、例えば、樹脂を有機溶剤中に溶解したものである。有機ビヒクルに用いる樹脂は特に限定されず、エチルセルロース、ポリビニルブチラール等の通常の各種樹脂から適宜選択すればよい。また、用いる有機溶剤も特に限定されず、印刷法やシート法など、利用する方法に応じて、テルピネオール、ブチルカルビトール、アセトン、トルエン等の各種有機溶剤から適宜選択すればよい。
また、水系ビヒクルは、例えば、ポリビニルアルコール、セルロース、水溶性アクリル樹脂が挙げられる。
セラミック基板は、公知のものが用いられ、例えば、ペロブスカイト系の誘電体で、チタン酸バリウムや、そのチタンの一部がジルコンに置換したもの、バリウムの一部がストロンチウムやカルシウム等に置換した誘電体が挙げられる。
内部電極の印刷方法は、層を均一に形成できる方法であれば特に限定されず、例えば、スクリーン印刷法、グラビア印刷法、蒸着法、スパッタリング法、インクジェット法が挙げられる。
[Internal electrodes for multilayer ceramic capacitors]
The internal electrode for the multilayer ceramic capacitor of the present embodiment (hereinafter also simply referred to as “internal electrode”) is manufactured by pasting the nickel fine particle-containing composition of the present embodiment and printing it on the ceramic substrate. The
When making the paste, a known viscosity modifier such as an organic vehicle or an aqueous vehicle may be mixed. By mixing the viscosity modifier, moderate fluidity and volatility are imparted to the paste, and a smooth internal electrode can be formed on the ceramic substrate.
The organic vehicle is obtained by, for example, dissolving a resin in an organic solvent. The resin used for the organic vehicle is not particularly limited, and may be appropriately selected from ordinary various resins such as ethyl cellulose and polyvinyl butyral. Further, the organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, toluene, and the like, depending on a method to be used such as a printing method or a sheet method.
Examples of the water-based vehicle include polyvinyl alcohol, cellulose, and a water-soluble acrylic resin.
A known ceramic substrate is used, for example, a perovskite-based dielectric material in which barium titanate or part of the titanium is replaced with zircon, and part of barium is replaced with strontium or calcium. The body is mentioned.
The internal electrode printing method is not particularly limited as long as the layer can be formed uniformly, and examples thereof include a screen printing method, a gravure printing method, a vapor deposition method, a sputtering method, and an ink jet method.
［積層セラミックコンデンサ］
本実施の形態の積層セラミックコンデンサは、前記内部電極とセラミックス誘電体とを交互に層状に重ねて圧着し、焼成して一体化させることによって製造される。
セラミックス誘導体は、公知のものが用いられ、前記のチタン酸バリウム等が挙げられる。これをペースト化し、前記内部電極上に層を形成する。ペースト化する際、有機ビヒクル、水系ビヒクル等の公知の粘度調整剤を混合させても良い。粘度調整剤を混合することで、前記ペーストに適度な流動性や揮発性が付与され、セラミック基板上に平滑な内部電極を形成することができる。有機ビヒクルは、例えば、樹脂を有機溶剤中に溶解したものである。有機ビヒクルに用いる樹脂は特に限定されず、エチルセルロース、ポリビニルブチラール等の通常の各種樹脂から適宜選択すればよい。また、用いる有機溶剤も特に限定されず、印刷法やシート法など、利用する方法に応じて、テルピネオール、ブチルカルビトール、アセトン、トルエン等の各種有機溶剤から適宜選択すればよい。
また、水系ビヒクルは、例えば、ポリビニルアルコール、セルロース、水溶性アクリル樹脂が挙げられる。
セラミックス誘電体の印刷方法は、層を均一に形成できる方法であれば特に限定されず、例えば、スクリーン印刷法、グラビア印刷法、蒸着法、スパッタリング法、インクジェット法が挙げられる。
内部電極とセラミックス誘導体の層及び層厚は限定しないが、例えば、数層〜１０００層であり、各層厚が、０．３μｍ〜２μｍである。
次に、このようにして得られた、内部電極とセラミックス誘導体の多層構造を、圧着し一体成型し、所定の大きさ（チップのサイズ）にカットし、焼成してチップを形成する。焼成温度は、例えば１０００℃〜１３００℃である。焼成後、チップの両端面に金属ペーストを塗布、熱処理し、その表面にメッキをすることで、外部電極を形成する。
[Multilayer ceramic capacitor]
The multilayer ceramic capacitor of the present embodiment is manufactured by alternately laminating the internal electrodes and ceramic dielectrics in layers, firing them, and integrating them.
A known ceramic derivative is used, and examples thereof include the above-mentioned barium titanate. This is pasted to form a layer on the internal electrode. When making the paste, a known viscosity modifier such as an organic vehicle or an aqueous vehicle may be mixed. By mixing the viscosity modifier, moderate fluidity and volatility are imparted to the paste, and a smooth internal electrode can be formed on the ceramic substrate. The organic vehicle is obtained by, for example, dissolving a resin in an organic solvent. The resin used for the organic vehicle is not particularly limited, and may be appropriately selected from ordinary various resins such as ethyl cellulose and polyvinyl butyral. Further, the organic solvent to be used is not particularly limited, and may be appropriately selected from various organic solvents such as terpineol, butyl carbitol, acetone, toluene, and the like, depending on a method to be used such as a printing method or a sheet method.
Examples of the water-based vehicle include polyvinyl alcohol, cellulose, and a water-soluble acrylic resin.
The ceramic dielectric printing method is not particularly limited as long as it can form a layer uniformly, and examples thereof include a screen printing method, a gravure printing method, a vapor deposition method, a sputtering method, and an ink jet method.
The layers and layer thicknesses of the internal electrode and the ceramic derivative are not limited, but are, for example, several layers to 1000 layers, and each layer thickness is 0.3 μm to 2 μm.
Next, the multilayer structure of the internal electrode and the ceramic derivative thus obtained is pressed and integrally molded, cut into a predetermined size (chip size), and fired to form a chip. The firing temperature is, for example, 1000 ° C to 1300 ° C. After firing, a metal paste is applied to both end faces of the chip, heat treated, and plated on the surface to form external electrodes.
このようにして製造された本発明の実施形態に係る積層セラミックコンデンサは、ハンダ付等によりプリント基板上などに実装され、各種電子機器等に使用される。
このような電子機器は、本発明のニッケル微粒子含有組成物を使用しているため、小型高容量化が可能であり、信頼性、高寿命性に優れ、電子部品の高温負荷寿命を向上させることができる
The multilayer ceramic capacitor according to the embodiment of the present invention thus manufactured is mounted on a printed board or the like by soldering or the like, and used for various electronic devices.
Such an electronic device uses the nickel fine particle-containing composition of the present invention, so that it can be reduced in size and capacity, has excellent reliability and long life, and improves the high temperature load life of electronic components. Can
以下、本発明を実施例により具体的に説明するが、本発明はこれらの実施例によって何ら限定されるものではない。なお、以下の実施例において、特にことわりのない限り各種測定、評価は下記によるものである。 EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the following examples, various measurements and evaluations are as follows unless otherwise specified.
［Ｄ５０、平均粒子径の測定］
ＳＥＭ（走査型電子顕微鏡）により試料の写真を撮影して、その中から無作為に３０００個を抽出してそれぞれの面積を求め、真球に換算したときの粒子径を個数基準として一次粒子のＤ９９、Ｄ５０及びＤ１を算出した。ここで、合成例４、５のニッケル微粒子は、ＳＥＭ倍率５万倍で、合成例６のニッケル微粒子はＳＥＭ倍率１０万倍で、合成例３のニッケル微粒子はＳＥＭ倍率１５万倍で、合成例１、２のニッケル微粒子はＳＥＭ倍率３０万倍で撮影した。また、ＣＶ値（変動係数）は、（標準偏差）÷（平均粒子径）によって算出した。なお、ＣＶ値が小さいほど、粒子径がより均一であることを示す。
[D50, measurement of average particle diameter]
Take a picture of the sample with an SEM (scanning electron microscope), extract 3000 randomly from it, determine the area of each, and use the particle diameter when converted to a true sphere as the basis for the number of primary particles. D99, D50 and D1 were calculated. Here, the nickel fine particles of Synthesis Examples 4 and 5 have a SEM magnification of 50,000 times, the nickel fine particles of Synthesis Example 6 have a SEM magnification of 100,000 times, and the nickel fine particles of Synthesis Example 3 have a SEM magnification of 150,000 times. The nickel fine particles 1 and 2 were photographed at an SEM magnification of 300,000 times. The CV value (coefficient of variation) was calculated by (standard deviation) / (average particle diameter). In addition, it shows that a particle diameter is so uniform that a CV value is small.
［ＳＥＭ観察による粒子分散性評価］
ＳＥＭ倍率１０万倍で観察し、大粒子３００個について、小粒子が大粒子の表面に接触して、又は大粒子間に接触して、存在する確率を計算した。
[Evaluation of particle dispersibility by SEM observation]
Observation was performed at an SEM magnification of 100,000, and the probability of existence of 300 large particles in contact with the surface of the large particles or between the large particles was calculated.
［熱機械分析（ＴＭＡ）、５％熱収縮温度］
試料を５Φ×２ｍｍの円柱状成型器に入れ、プレス成型して得られる成型体を作製し、窒素ガス（水素ガス３％含有）の雰囲気下で、熱機械分析（ＴＭＡ）を行った。また、熱機械分析装置（ＴＭＡ）により測定される５％熱収縮の温度を５％熱収縮温度とした。
[Thermomechanical analysis (TMA), 5% heat shrink temperature]
The sample was put into a 5Φ × 2 mm cylindrical molding machine, and a molded body obtained by press molding was prepared, and thermomechanical analysis (TMA) was performed in an atmosphere of nitrogen gas (containing 3% hydrogen gas). Moreover, the temperature of 5% heat shrinkage measured by a thermomechanical analyzer (TMA) was taken as 5% heat shrinkage temperature.
［表面平滑性Ｒａ］
比較例１では、混合した乾燥ニッケル微粒子を、トルエン中で超音波ホモジナイザーを用いて５分間分散させた後、エバポレーターでトルエンを除去し、スラリー中のニッケル濃度を５０質量％まで濃縮した。この濃縮物をガラス板上に塗布して、８０℃で乾燥後、接触式の表面粗さ計で平滑性Ｒａを測定した。
実施例１〜８では、全てスラリー状のニッケル微粒子を混合した以外は、比較例１と同様にして、平滑性Ｒａを測定した。
合成例１〜６のニッケル微粒子については、粒子合成後の反応液に対し、トルエン洗浄と遠心分離を５回繰り返し行った後、エバポレーターでトルエンを除去して、スラリー中のニッケル濃度を５０質量％まで濃縮した後、比較例１と同様にして平滑性Ｒａを測定した。
[Surface smoothness Ra]
In Comparative Example 1, the mixed dry nickel fine particles were dispersed in toluene using an ultrasonic homogenizer for 5 minutes, and then toluene was removed by an evaporator to concentrate the nickel concentration in the slurry to 50% by mass. The concentrate was applied on a glass plate, dried at 80 ° C., and smoothness Ra was measured with a contact-type surface roughness meter.
In Examples 1 to 8, smoothness Ra was measured in the same manner as in Comparative Example 1 except that all of the slurry-like nickel fine particles were mixed.
Regarding the nickel fine particles of Synthesis Examples 1 to 6, the reaction solution after particle synthesis was repeatedly washed with toluene and centrifuged five times, and then the toluene was removed by an evaporator, so that the nickel concentration in the slurry was 50% by mass. After the concentration, the smoothness Ra was measured in the same manner as in Comparative Example 1.
（合成例１）
＜錯化反応液の調製＞
６．０ｋｇのオレイルアミンに７０ｇのギ酸銅四水和物と３５０ｇのギ酸ニッケル二水和物を加え、窒素フロー下で１２０℃、６０分間加熱することでギ酸銅とギ酸ニッケルをオレイルアミンに溶解した。
(Synthesis Example 1)
<Preparation of complexing reaction solution>
70 g of copper formate tetrahydrate and 350 g of nickel formate dihydrate were added to 6.0 kg of oleylamine, and copper formate and nickel formate were dissolved in oleylamine by heating at 120 ° C. for 60 minutes under a nitrogen flow.
上記の溶解液にマイクロ波を照射して１９０℃、１０分間加熱して、６．１ｋｇのニッケル微粒子スラリー（１−Ａ）を調製した。得られたニッケル微粒子スラリー（１−Ａ）の１００ｇを分取して、上澄み液を取り除いた後、トルエンとメタノールを用いてそれぞれ２回洗浄した後、６０℃に維持される真空乾燥機で６時間乾燥してニッケル微粒子Ａを調製した。 The above solution was irradiated with microwaves and heated at 190 ° C. for 10 minutes to prepare 6.1 kg of nickel fine particle slurry (1-A). 100 g of the obtained nickel fine particle slurry (1-A) was collected, the supernatant was removed, and each was washed twice with toluene and methanol, and then 6 times in a vacuum dryer maintained at 60 ° C. Nickel fine particles A were prepared by drying for a period of time.
ニッケル微粒子ＡのＳＥＭ写真を参照すると、ニッケル微粒子Ａの平均粒子径は１５ｎｍ、ＣＶ値は０．１４、銅元素の含有量は１５．０６質量％であった。 Referring to the SEM photograph of the nickel fine particles A, the average particle size of the nickel fine particles A was 15 nm, the CV value was 0.14, and the copper element content was 15.06% by mass.
（合成例２）
＜錯化反応液の調製＞
６．０ｋｇのオレイルアミンに１３３ｇのギ酸銅四水和物と３５０ｇのギ酸ニッケル二水和物を加え、窒素フロー下で１２０℃、６０分間加熱することでギ酸銅とギ酸ニッケルをオレイルアミンに溶解した。
(Synthesis Example 2)
<Preparation of complexing reaction solution>
133 g of copper formate tetrahydrate and 350 g of nickel formate dihydrate were added to 6.0 kg of oleylamine, and copper formate and nickel formate were dissolved in oleylamine by heating at 120 ° C. for 60 minutes under a nitrogen flow.
上記の溶解液にマイクロ波を照射して１９０℃、１０分間加熱して、６．１４ｋｇのニッケル微粒子スラリー（２−Ａ）を調製した。得られたニッケル微粒子スラリー（２−Ａ）の１００ｇを分取して、上澄み液を取り除いた後、トルエンとメタノールを用いてそれぞれ２回洗浄した後、６０℃に維持される真空乾燥機で６時間乾燥してニッケル微粒子Ｂを調製した。 The solution was irradiated with microwaves and heated at 190 ° C. for 10 minutes to prepare 6.14 kg of nickel fine particle slurry (2-A). 100 g of the resulting nickel fine particle slurry (2-A) was collected, the supernatant was removed, and each was washed twice with toluene and methanol, and then 6 times in a vacuum dryer maintained at 60 ° C. Nickel fine particles B were prepared by drying for a period of time.
ニッケル微粒子ＢのＳＥＭ写真を参照すると、ニッケル微粒子Ｂの平均粒子径は１２ｎｍ、ＣＶ値は０．１３、銅元素の含有量は２５．２０質量％であった。 Referring to the SEM photograph of the nickel fine particles B, the average particle size of the nickel fine particles B was 12 nm, the CV value was 0.13, and the content of the copper element was 25.20% by mass.
（合成例３）
＜錯化反応液の調製＞
６．０ｋｇのオレイルアミンに１７ｇのギ酸銅四水和物と３５０ｇのギ酸ニッケル二水和物を加え、窒素フロー下で１２０℃、６０分間加熱することでギ酸銅とギ酸ニッケルをオレイルアミンに溶解した。
(Synthesis Example 3)
<Preparation of complexing reaction solution>
17 g of copper formate tetrahydrate and 350 g of nickel formate dihydrate were added to 6.0 kg of oleylamine, and copper formate and nickel formate were dissolved in oleylamine by heating at 120 ° C. for 60 minutes under a nitrogen flow.
上記の溶解液にマイクロ波を照射して１９０℃、１０分間加熱して、さらにその温度を２０分間維持したのち放冷して、６．０５ｋｇのニッケル微粒子スラリー（３−Ａ）を調製した。得られたニッケル微粒子スラリー（３−Ａ）の１００ｇを分取して、上澄み液を取り除いた後、トルエンとメタノールを用いてそれぞれ２回洗浄した後、６０℃に維持される真空乾燥機で６時間乾燥してニッケル微粒子Ｃを調製した。 The above solution was irradiated with microwaves, heated at 190 ° C. for 10 minutes, further maintained at that temperature for 20 minutes, and then allowed to cool to prepare 6.05 kg of nickel fine particle slurry (3-A). 100 g of the obtained nickel fine particle slurry (3-A) was collected, the supernatant was removed, and each was washed twice with toluene and methanol, and then 6 times in a vacuum dryer maintained at 60 ° C. Nickel fine particles C were prepared by drying for a period of time.
ニッケル微粒子ＣのＳＥＭ写真を参照すると、ニッケル微粒子Ｃの平均粒子径は３０ｎｍ、ＣＶ値は０．１７、銅元素の含有量は４．１３質量％であった。 Referring to the SEM photograph of the nickel fine particles C, the average particle size of the nickel fine particles C was 30 nm, the CV value was 0.17, and the copper element content was 4.13 mass%.
（合成例４）
＜ニッケル錯体溶液の調製＞
５０．０ｋｇのオレイルアミンに２０．６ｋｇの酢酸ニッケル四水和物を加え、窒素フロー下で１４０℃、４時間加熱することでニッケル錯体溶液を調製した。
(Synthesis Example 4)
<Preparation of nickel complex solution>
A nickel complex solution was prepared by adding 20.6 kg of nickel acetate tetrahydrate to 50.0 kg of oleylamine and heating at 140 ° C. for 4 hours under a nitrogen flow.
＜ニッケル微粒子の調製＞
上記ニッケル錯体溶液の１１．２８ｋｇを分取し、そこに、合成例１で得た６５ｇのニッケル微粒子スラリー（１−Ａ）を加え、撹拌後、マイクロ波を照射して２２５℃、１０分間加熱して、オレイルアミンで希釈した２００ｇの１０％ドデカンチオール溶液を１５分間で滴下して、さらにその温度を２０分間維持したのち放冷して、ニッケル微粒子スラリー（４−Ａ）を調製した。得られたニッケル微粒子スラリー（４−Ａ）を静置分離し、上澄み液を取り除いた後、トルエンとメタノールを用いてそれぞれ２回洗浄した後、６０℃に維持される真空乾燥機で６時間乾燥してニッケル微粒子Ｄを調製した。
<Preparation of nickel fine particles>
11.28 kg of the above nickel complex solution was taken, and 65 g of the nickel fine particle slurry (1-A) obtained in Synthesis Example 1 was added thereto, stirred, and then irradiated with microwaves and heated at 225 ° C. for 10 minutes. Then, 200 g of a 10% dodecanethiol solution diluted with oleylamine was added dropwise over 15 minutes, and the temperature was further maintained for 20 minutes, followed by cooling to prepare a nickel fine particle slurry (4-A). The obtained nickel fine particle slurry (4-A) was allowed to stand and separated, the supernatant was removed, washed twice with toluene and methanol, and then dried in a vacuum dryer maintained at 60 ° C. for 6 hours. Thus, nickel fine particles D were prepared.
ニッケル微粒子ＤのＳＥＭ写真を参照すると、ニッケル微粒子Ｄの平均粒子径は１２５ｎｍ、ＣＶ値は０．１５、銅元素の含有量は０．０２５質量％であった。 Referring to the SEM photograph of the nickel fine particles D, the average particle size of the nickel fine particles D was 125 nm, the CV value was 0.15, and the content of the copper element was 0.025% by mass.
（合成例５）
＜ニッケル錯体溶液の調製＞
合成例４と同様にして、ニッケル錯体溶液を調製した。
(Synthesis Example 5)
<Preparation of nickel complex solution>
A nickel complex solution was prepared in the same manner as in Synthesis Example 4.
＜ニッケル微粒子の調製＞
上記ニッケル錯体溶液の９．５０ｋｇを分取し、そこに、合成例２で得た１００ｇのニッケル微粒子スラリー（２−Ａ）を加え、撹拌後、マイクロ波を照射して２２５℃、１０分間加熱して、オレイルアミンで希釈した１８０ｇの１０％ドデカンチオール溶液を１５分間で滴下して、さらにその温度を２０分間維持したのち放冷して、ニッケル微粒子スラリー（５−Ａ）を調製した。得られたニッケル微粒子スラリー（５−Ａ）を静置分離し、上澄み液を取り除いた後、トルエンとメタノールを用いてそれぞれ２回洗浄した後、６０℃に維持される真空乾燥機で６時間乾燥してニッケル微粒子Ｅを調製した。
<Preparation of nickel fine particles>
9.50 kg of the above nickel complex solution was taken, and 100 g of the nickel fine particle slurry (2-A) obtained in Synthesis Example 2 was added thereto. After stirring, the microwave was irradiated and heated at 225 ° C. for 10 minutes. Then, 180 g of 10% dodecanethiol solution diluted with oleylamine was added dropwise over 15 minutes, and the temperature was further maintained for 20 minutes, followed by cooling to prepare a nickel fine particle slurry (5-A). The obtained nickel fine particle slurry (5-A) was allowed to stand and separated, the supernatant was removed, washed twice with toluene and methanol, and then dried in a vacuum dryer maintained at 60 ° C. for 6 hours. Thus, nickel fine particles E were prepared.
ニッケル微粒子ＥのＳＥＭ写真を参照すると、ニッケル微粒子Ｅの平均粒子径は８０ｎｍ、ＣＶ値は０．１４、銅元素の含有量は０．０８２質量％であった。 Referring to the SEM photograph of the nickel fine particles E, the average particle size of the nickel fine particles E was 80 nm, the CV value was 0.14, and the content of the copper element was 0.082% by mass.
（合成例６）
＜ニッケル錯体溶液の調製＞
合成例４と同様にして、ニッケル錯体溶液を調製した。
(Synthesis Example 6)
<Preparation of nickel complex solution>
A nickel complex solution was prepared in the same manner as in Synthesis Example 4.
＜ニッケル微粒子の調製＞
上記ニッケル錯体溶液の９．５０ｋｇを分取し、そこに、合成例２で得た３７０ｇのニッケル微粒子スラリー（２−Ａ）を加え、撹拌後、マイクロ波を照射して２２５℃、１０分間加熱することによってニッケル微粒子スラリー（６−Ａ）を調製した。得られたニッケル微粒子スラリー（６−Ａ）を静置分離し、上澄み液を取り除いた後、トルエンとメタノールを用いてそれぞれ２回洗浄した後、６０℃に維持される真空乾燥機で６時間乾燥してニッケル微粒子Ｆを調製した。
<Preparation of nickel fine particles>
9.50 kg of the above nickel complex solution was fractionated, and 370 g of the nickel fine particle slurry (2-A) obtained in Synthesis Example 2 was added thereto, and after stirring, irradiated with microwaves and heated at 225 ° C. for 10 minutes. Thus, a nickel fine particle slurry (6-A) was prepared. The obtained nickel fine particle slurry (6-A) was allowed to stand and separated, the supernatant was removed, washed twice with toluene and methanol, and then dried in a vacuum dryer maintained at 60 ° C. for 6 hours. Thus, nickel fine particles F were prepared.
ニッケル微粒子ＦのＳＥＭ写真を参照すると、ニッケル微粒子Ｆの平均粒子径は５０ｎｍ、ＣＶ値は０．１１、銅元素の含有量は０．０２９質量％であった。 Referring to the SEM photograph of the nickel fine particles F, the average particle size of the nickel fine particles F was 50 nm, the CV value was 0.11, and the content of the copper element was 0.029% by mass.
以下、説明の便宜上、合成例１〜３で得たニッケル微粒子を「小粒子」、合成例４〜６で得たニッケル微粒子を「大粒子」と記すことがある。 Hereinafter, for convenience of description, the nickel fine particles obtained in Synthesis Examples 1 to 3 may be referred to as “small particles”, and the nickel fine particles obtained in Synthesis Examples 4 to 6 may be referred to as “large particles”.
［実施例１〜８］
上記合成例で得られたニッケル微粒子のスラリーを、表２に記載した比率となるように混合することによって、ニッケル微粒子含有組成物を調製した。混合に際しては、セラミックスフィルタ（小粒子が１５ｎｍの場合は孔径１０ｎｍ、小粒子が１２ｎｍの場合は孔径５ｎｍ）で大粒子と同時に粒子洗浄を行った。洗浄及び混合の方法、得られたニッケル微粒子含有組成物の５％熱収縮温度、表面平滑性Ｒａを表２に示した。また、実施例１〜８で得られたニッケル微粒子含有組成物のＳＥＭ画像をそれぞれ図２〜９に示した。また、図２〜９に示すように、実施例１〜８のニッケル微粒子含有組成物は、走査型電子顕微鏡観察によって任意の３００個の大粒子を観察したときに、表面に少なくとも１個以上の小粒子が接触している大粒子の存在確率が３０％以上であり、大粒子の表面に、小粒子がほぼ均等に分布して存在していた。
[Examples 1 to 8]
The nickel fine particle-containing composition was prepared by mixing the nickel fine particle slurry obtained in the above synthesis example so as to have the ratio shown in Table 2. During mixing, the particles were washed simultaneously with the large particles with a ceramics filter (pore size 10 nm when the small particles were 15 nm, and pore size 5 nm when the small particles were 12 nm). Table 2 shows the washing and mixing methods, the 5% heat shrinkage temperature, and the surface smoothness Ra of the obtained nickel fine particle-containing composition. Moreover, the SEM image of the nickel fine particle containing composition obtained in Examples 1-8 was shown to FIGS. 2-9, respectively. As shown in FIGS. 2 to 9, the nickel fine particle-containing compositions of Examples 1 to 8 had at least one or more particles on the surface when any 300 large particles were observed by scanning electron microscope observation. The existence probability of the large particles in contact with the small particles is 30% or more, and the small particles are present almost uniformly distributed on the surface of the large particles.
表２より、洗浄、混合工程で、小粒子の洗浄にセラミックスフィルタを用いることによって、小粒子が流出することなく洗浄でき、均一に混合されていることがわかる。小粒子の存在確率は全て３０％で熱挙動、平滑性ともに向上している。 From Table 2, it can be seen that by using a ceramic filter for washing small particles in the washing and mixing steps, the small particles can be washed without flowing out and mixed uniformly. The existence probability of small particles is 30%, and both thermal behavior and smoothness are improved.
［比較例１〜４］
上記合成例で得られたニッケル微粒子のスラリーを、表３に記載した比率となるように混合することによって、ニッケル微粒子含有組成物を調製した。洗浄及び混合の方法、得られたニッケル微粒子含有組成物の５％熱収縮温度、表面平滑性Ｒａを表３に示した。また、比較例１〜４で得られたニッケル微粒子含有組成物のＳＥＭ画像を、それぞれ図１０〜１３に示した。図１０〜１２に示すように、比較例１〜３のニッケル微粒子含有組成物は、小粒子の洗浄を遠心分離又は磁気分離で行ったことによって、小粒子が流出した結果、走査型電子顕微鏡観察によって任意の３００個の大粒子を観察したときに、表面に少なくとも１個以上の小粒子が接触している大粒子の存在確率が３０％未満であった。
また、図１３に示すように、比較例４では、走査型電子顕微鏡観察によって任意の３００個の大粒子を観察したときに、表面に少なくとも１個以上の小粒子が接触している大粒子の存在確率が３０％以上であったが、大粒子のＤ５０に対して小粒子のＤ５０が大きすぎるため、大粒子の表面に接触している小粒子の分布が不均一であった。
[Comparative Examples 1-4]
The nickel fine particle-containing composition was prepared by mixing the nickel fine particle slurry obtained in the above synthesis example so as to have the ratio shown in Table 3. Table 3 shows the method of washing and mixing, the 5% heat shrinkage temperature, and the surface smoothness Ra of the obtained nickel fine particle-containing composition. Moreover, the SEM image of the nickel fine particle containing composition obtained by Comparative Examples 1-4 was shown to FIGS. 10-13, respectively. As shown in FIGS. 10 to 12, the nickel fine particle-containing compositions of Comparative Examples 1 to 3 were observed by a scanning electron microscope as a result of the small particles flowing out by washing the small particles by centrifugation or magnetic separation. When arbitrary 300 large particles were observed by the above, the existence probability of large particles having at least one or more small particles in contact with the surface was less than 30%.
Moreover, as shown in FIG. 13, in Comparative Example 4, when 300 arbitrary large particles were observed by scanning electron microscope observation, the large particles having at least one small particle in contact with the surface were observed. Although the existence probability was 30% or more, the D50 of the small particles was too large with respect to the D50 of the large particles, so that the distribution of the small particles in contact with the surface of the large particles was not uniform.
表２及び表３より、実施例１〜８のニッケル微粒子含有組成物は、いずれも比較例に比べ、５％収縮温度が高く、かつ表面平滑性が良好であった。 From Tables 2 and 3, the nickel fine particle-containing compositions of Examples 1 to 8 all had a 5% shrinkage temperature higher than that of the comparative example, and good surface smoothness.
以上、本発明の実施の形態を例示の目的で詳細に説明したが、本発明は上記実施の形態に制約されることはなく、種々の変形が可能である。 As mentioned above, although embodiment of this invention was described in detail for the purpose of illustration, this invention is not restrict | limited to the said embodiment, A various deformation | transformation is possible.
１０…第１のニッケル微粒子、２０…第２のニッケル微粒子、１００…ニッケル微粒子含有組成物
DESCRIPTION OF SYMBOLS 10 ... 1st nickel fine particle, 20 ... 2nd nickel fine particle, 100 ... Nickel fine particle containing composition
Claims (12)
Ａ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０Ａが４０〜２００ｎｍの範囲内である第１のニッケル微粒子、
及び、
Ｂ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０Ｂが５ｎｍ以上４０ｎｍ未満の範囲内である第２のニッケル微粒子、
を含有するとともに、
走査型電子顕微鏡観察によって任意の３００個の前記第１のニッケル微粒子を観察したときに、表面に少なくとも１個以上の前記第２のニッケル微粒子が接触している前記第１のニッケル微粒子の存在確率が３０％以上であるニッケル微粒子含有組成物。 The following components A and B;
A) a first nickel fine particle having an average particle diameter D50 A in the range of 40 to 200 nm in a number-based particle size distribution by scanning electron microscope observation;
as well as,
B) Second nickel fine particles whose average particle diameter D50 B is in the range of 5 nm or more and less than 40 nm in the number-based particle size distribution by scanning electron microscope observation,
And containing
Presence probability of the first nickel fine particles in which at least one of the second nickel fine particles is in contact with the surface when any 300 of the first nickel fine particles are observed by observation with a scanning electron microscope A nickel fine particle-containing composition having a content of 30% or more.
Ｄ５０Ａ＞Ｄ５０Ｂ×４ … （１）
かつ
Ｄ１Ａ−Ｄ９９Ｂ ＞ （Ｄ５０Ａ−Ｄ５０Ｂ）／４ … （２）
を満たすものである請求項１に記載のニッケル微粒子含有組成物。 In the particle size distribution on the basis of the number by scanning electron microscope observation, the value at which the cumulative particle size distribution from the small particle size side of the first nickel fine particles is 1% is D1 A , and the value from the small particle size side of the second nickel fine particles is When the value at which the cumulative particle size distribution is 99% is D99 B , the following relationship:
D50 A > D50 B × 4 (1)
And D1 A -D99 B> (D50 A -D50 B) / 4 ... (2)
The nickel fine particle-containing composition according to claim 1, wherein:
ａ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０が４０〜２００ｎｍの範囲内である第１のニッケル微粒子のスラリーを得る工程、
ｂ）走査型電子顕微鏡観察による個数基準の粒度分布において、平均粒子径Ｄ５０が５ｎｍ以上４０ｎｍ未満の範囲内である第２のニッケル微粒子のスラリーを得る工程、
ｃ）前記第２のニッケル微粒子を溶剤で洗浄する工程、
及び
ｄ）前記第１のニッケル微粒子と前記第２のニッケル微粒子とを混合する工程、
を含み、
前記工程ｃは、前記第２のニッケル微粒子の平均粒子径Ｄ５０に対して１０％以上小さな平均孔径を有するフィルタを用い、前記第２のニッケル微粒子を前記溶剤とともに前記フィルタでろ過することにより行われ、
かつ、
前記工程ｄは、前記工程ｃと同時に、又は前記工程ｃの後で引き続き、前記フィルタで前記第１のニッケル微粒子をろ過することによって行われるニッケル微粒子含有組成物の製造方法。 The following steps a to d;
a) obtaining a slurry of first nickel fine particles having an average particle diameter D50 in the range of 40 to 200 nm in a number-based particle size distribution by scanning electron microscope observation;
b) a step of obtaining a slurry of second nickel fine particles having an average particle diameter D50 in the range of 5 nm or more and less than 40 nm in a number-based particle size distribution by scanning electron microscope observation;
c) washing the second nickel fine particles with a solvent;
And d) mixing the first nickel fine particles and the second nickel fine particles,
Including
The step c is performed by using a filter having an average pore size that is 10% or more smaller than the average particle size D50 of the second nickel fine particles, and filtering the second nickel fine particles together with the solvent. ,
And,
The step d is a method for producing a nickel fine particle-containing composition performed by filtering the first nickel fine particles with the filter simultaneously with the step c or subsequently after the step c.
The nickel according to any one of claims 8 to 11, wherein the first nickel fine particles obtained in the step a are obtained by using the second nickel fine particles obtained in the step b as seed particles. A method for producing a fine particle-containing composition.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015257683 | 2015-12-29 | ||
| JP2015257683 | 2015-12-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2017119906A true JP2017119906A (en) | 2017-07-06 |
| JP6799931B2 JP6799931B2 (en) | 2020-12-16 |
Family
ID=59271683
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2016039883A Active JP6799931B2 (en) | 2015-12-29 | 2016-03-02 | Nickel fine particle-containing composition and its manufacturing method, internal electrodes and laminated ceramic capacitors |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6799931B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114068919A (en) * | 2020-08-06 | 2022-02-18 | 比亚迪股份有限公司 | Lithium iron phosphate positive electrode active material, preparation method thereof, positive plate and battery |
-
2016
- 2016-03-02 JP JP2016039883A patent/JP6799931B2/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114068919A (en) * | 2020-08-06 | 2022-02-18 | 比亚迪股份有限公司 | Lithium iron phosphate positive electrode active material, preparation method thereof, positive plate and battery |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6799931B2 (en) | 2020-12-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5843821B2 (en) | Metal powder paste and method for producing the same | |
| JP6799936B2 (en) | Nickel particles, conductive paste, internal electrodes and multilayer ceramic capacitors | |
| JP4389431B2 (en) | Conductive paste for gravure printing, method for producing the same, and multilayer ceramic electronic component | |
| US20110141654A1 (en) | Nickel powder or alloy powder comprising nickel as main component, method for producing the same, conductive paste and laminated ceramic capacitor | |
| JP2006152439A (en) | Surface treatment method of nickel nanoparticle | |
| JP2010053409A (en) | Method for producing metal powder, metal powder, electrically conductive paste, and multilayer ceramic capacitor | |
| TW200920857A (en) | Nickel powder or alloy powder comprising nickel as main component and manufacturing method thereof, conductive paste and multi-layer ceramic condenser | |
| JP2021105214A (en) | Nickel powder and method for producing the same, and nickel paste | |
| JP5862835B2 (en) | Method for producing metal powder, method for producing conductive paste, and method for producing multilayer ceramic electronic component | |
| CA3065687C (en) | Metallic powders for use as electrode material in multilayer ceramic capacitors and method of manufacturing and of using same | |
| JP6539520B2 (en) | Nickel fine particle containing composition and method for producing the same | |
| JP5327442B2 (en) | Nickel-rhenium alloy powder and conductor paste containing the same | |
| JP2015049973A (en) | Conductive paste and method for manufacturing composite nickel fine particle used therefor | |
| JP5046044B2 (en) | Method for producing magnesium oxide nanoparticles and method for producing magnesium oxide nanoparticles | |
| JP2007191752A (en) | Tin-coated silver powder and method for producing the tin-coated silver powder | |
| JP6799931B2 (en) | Nickel fine particle-containing composition and its manufacturing method, internal electrodes and laminated ceramic capacitors | |
| TW201842989A (en) | Nickel powder and nickel paste | |
| JP6630208B2 (en) | Method for producing metal powder paste, screen printing method for metal powder paste, method for producing electrodes, method for producing chip multilayer ceramic capacitor, and metal powder paste | |
| JP2015151558A (en) | Nickel fine particle slurry, metal fine particle and method for producing the same | |
| JP6558750B2 (en) | Nickel fine particle-containing composition and method for producing the same | |
| CA3045573C (en) | Metallic powders for use as electrode material in multilayer ceramic capacitors and method of manufacturing and of using same | |
| JP2013149855A (en) | Conductive paste for multilayer ceramic capacitor and multilayer ceramic capacitor | |
| JPH07197103A (en) | Method for coating surface of metallic powder with metallic compound | |
| JP2013067865A (en) | Metal powder, electroconductive paste and multilayer ceramic capacitor | |
| WO2016139967A1 (en) | Nickel particles and method for producing same, and electrically conductive paste |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20190220 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20200117 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20200303 |
|
| A601 | Written request for extension of time |
Free format text: JAPANESE INTERMEDIATE CODE: A601 Effective date: 20200427 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20200629 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20201117 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20201124 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6799931 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |