JP2011074476A - Method for producing copper nanoparticle - Google Patents
Method for producing copper nanoparticle Download PDFInfo
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- JP2011074476A JP2011074476A JP2009229482A JP2009229482A JP2011074476A JP 2011074476 A JP2011074476 A JP 2011074476A JP 2009229482 A JP2009229482 A JP 2009229482A JP 2009229482 A JP2009229482 A JP 2009229482A JP 2011074476 A JP2011074476 A JP 2011074476A
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- Prior art keywords
- reduction reaction
- copper
- fine particles
- aqueous solution
- copper fine
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- 239000010949 copper Substances 0.000 title claims abstract description 151
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title claims abstract description 147
- 229910052802 copper Inorganic materials 0.000 title claims abstract description 136
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 34
- 239000002105 nanoparticle Substances 0.000 title abstract description 10
- 238000006722 reduction reaction Methods 0.000 claims abstract description 134
- 239000007864 aqueous solution Substances 0.000 claims abstract description 95
- 239000002245 particle Substances 0.000 claims abstract description 50
- 239000012279 sodium borohydride Substances 0.000 claims abstract description 38
- 229910000033 sodium borohydride Inorganic materials 0.000 claims abstract description 38
- 239000002270 dispersing agent Substances 0.000 claims abstract description 31
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 claims abstract description 30
- 229910001431 copper ion Inorganic materials 0.000 claims abstract description 29
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 19
- 239000000243 solution Substances 0.000 claims abstract description 19
- 230000002829 reductive effect Effects 0.000 claims abstract description 17
- 238000003756 stirring Methods 0.000 claims abstract description 14
- 238000004090 dissolution Methods 0.000 claims abstract description 8
- JJLJMEJHUUYSSY-UHFFFAOYSA-L Copper hydroxide Chemical compound [OH-].[OH-].[Cu+2] JJLJMEJHUUYSSY-UHFFFAOYSA-L 0.000 claims description 157
- 239000010419 fine particle Substances 0.000 claims description 133
- 239000011164 primary particle Substances 0.000 claims description 29
- 238000000034 method Methods 0.000 claims description 11
- 229920000036 polyvinylpyrrolidone Polymers 0.000 claims description 6
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 claims description 6
- 239000001267 polyvinylpyrrolidone Substances 0.000 claims description 5
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 4
- 108010010803 Gelatin Proteins 0.000 claims description 4
- 229920003171 Poly (ethylene oxide) Polymers 0.000 claims description 4
- 229920002873 Polyethylenimine Polymers 0.000 claims description 4
- 229920002472 Starch Polymers 0.000 claims description 4
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 4
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 4
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 4
- 229920000159 gelatin Polymers 0.000 claims description 4
- 239000008273 gelatin Substances 0.000 claims description 4
- 235000019322 gelatine Nutrition 0.000 claims description 4
- 235000011852 gelatine desserts Nutrition 0.000 claims description 4
- 229920002401 polyacrylamide Polymers 0.000 claims description 4
- 239000008107 starch Substances 0.000 claims description 4
- 235000019698 starch Nutrition 0.000 claims description 4
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 3
- 229920002125 Sokalan® Polymers 0.000 claims description 3
- 239000004584 polyacrylic acid Substances 0.000 claims description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 3
- 238000009826 distribution Methods 0.000 abstract description 19
- 229920006395 saturated elastomer Polymers 0.000 abstract description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 abstract 5
- 239000006185 dispersion Substances 0.000 description 21
- 239000002994 raw material Substances 0.000 description 19
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 10
- 230000005540 biological transmission Effects 0.000 description 8
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 7
- 150000007514 bases Chemical class 0.000 description 7
- 239000011259 mixed solution Substances 0.000 description 7
- 239000012071 phase Substances 0.000 description 7
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000008346 aqueous phase Substances 0.000 description 5
- 125000004432 carbon atom Chemical group C* 0.000 description 5
- 238000011156 evaluation Methods 0.000 description 5
- 238000010298 pulverizing process Methods 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 4
- 238000004220 aggregation Methods 0.000 description 4
- 230000002776 aggregation Effects 0.000 description 4
- -1 amine compound Chemical class 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 229960004643 cupric oxide Drugs 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical class [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 3
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 229910000365 copper sulfate Inorganic materials 0.000 description 3
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 3
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 230000035484 reaction time Effects 0.000 description 3
- 239000003381 stabilizer Substances 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- RFFLAFLAYFXFSW-UHFFFAOYSA-N 1,2-dichlorobenzene Chemical compound ClC1=CC=CC=C1Cl RFFLAFLAYFXFSW-UHFFFAOYSA-N 0.000 description 2
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 239000005749 Copper compound Substances 0.000 description 2
- 239000005750 Copper hydroxide Substances 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- 239000002202 Polyethylene glycol Substances 0.000 description 2
- 125000005595 acetylacetonate group Chemical group 0.000 description 2
- 230000004931 aggregating effect Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- DIKBFYAXUHHXCS-UHFFFAOYSA-N bromoform Chemical compound BrC(Br)Br DIKBFYAXUHHXCS-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 235000017168 chlorine Nutrition 0.000 description 2
- 150000001805 chlorine compounds Chemical class 0.000 description 2
- 150000001879 copper Chemical class 0.000 description 2
- 150000001880 copper compounds Chemical class 0.000 description 2
- 229910001956 copper hydroxide Inorganic materials 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 2
- AEJIMXVJZFYIHN-UHFFFAOYSA-N copper;dihydrate Chemical compound O.O.[Cu] AEJIMXVJZFYIHN-UHFFFAOYSA-N 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 150000008282 halocarbons Chemical class 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229920001223 polyethylene glycol Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- SCYULBFZEHDVBN-UHFFFAOYSA-N 1,1-Dichloroethane Chemical compound CC(Cl)Cl SCYULBFZEHDVBN-UHFFFAOYSA-N 0.000 description 1
- WSLDOOZREJYCGB-UHFFFAOYSA-N 1,2-Dichloroethane Chemical compound ClCCCl WSLDOOZREJYCGB-UHFFFAOYSA-N 0.000 description 1
- KNKRKFALVUDBJE-UHFFFAOYSA-N 1,2-dichloropropane Chemical compound CC(Cl)CCl KNKRKFALVUDBJE-UHFFFAOYSA-N 0.000 description 1
- ZPQOPVIELGIULI-UHFFFAOYSA-N 1,3-dichlorobenzene Chemical compound ClC1=CC=CC(Cl)=C1 ZPQOPVIELGIULI-UHFFFAOYSA-N 0.000 description 1
- OCJBOOLMMGQPQU-UHFFFAOYSA-N 1,4-dichlorobenzene Chemical compound ClC1=CC=C(Cl)C=C1 OCJBOOLMMGQPQU-UHFFFAOYSA-N 0.000 description 1
- JTPNRXUCIXHOKM-UHFFFAOYSA-N 1-chloronaphthalene Chemical compound C1=CC=C2C(Cl)=CC=CC2=C1 JTPNRXUCIXHOKM-UHFFFAOYSA-N 0.000 description 1
- SZIFAVKTNFCBPC-UHFFFAOYSA-N 2-chloroethanol Chemical compound OCCCl SZIFAVKTNFCBPC-UHFFFAOYSA-N 0.000 description 1
- CGYGETOMCSJHJU-UHFFFAOYSA-N 2-chloronaphthalene Chemical compound C1=CC=CC2=CC(Cl)=CC=C21 CGYGETOMCSJHJU-UHFFFAOYSA-N 0.000 description 1
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 1
- OSDWBNJEKMUWAV-UHFFFAOYSA-N Allyl chloride Chemical class ClCC=C OSDWBNJEKMUWAV-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 239000012691 Cu precursor Substances 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-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
- 230000002378 acidificating effect Effects 0.000 description 1
- 230000001476 alcoholic effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910000272 alkali metal oxide Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910001860 alkaline earth metal hydroxide Inorganic materials 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 150000003868 ammonium compounds Chemical class 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 150000001491 aromatic compounds Chemical class 0.000 description 1
- CPWPJLJWUXOOAB-UHFFFAOYSA-N benzene;bromine Chemical compound [Br].C1=CC=CC=C1 CPWPJLJWUXOOAB-UHFFFAOYSA-N 0.000 description 1
- KCXMKQUNVWSEMD-UHFFFAOYSA-N benzyl chloride Chemical compound ClCC1=CC=CC=C1 KCXMKQUNVWSEMD-UHFFFAOYSA-N 0.000 description 1
- 229940073608 benzyl chloride Drugs 0.000 description 1
- MOOAHMCRPCTRLV-UHFFFAOYSA-N boron sodium Chemical compound [B].[Na] MOOAHMCRPCTRLV-UHFFFAOYSA-N 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 229950005228 bromoform Drugs 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 125000002843 carboxylic acid group Chemical group 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 125000001309 chloro group Chemical class Cl* 0.000 description 1
- NEHMKBQYUWJMIP-NJFSPNSNSA-N chloro(114C)methane Chemical compound [14CH3]Cl NEHMKBQYUWJMIP-NJFSPNSNSA-N 0.000 description 1
- HRYZWHHZPQKTII-UHFFFAOYSA-N chloroethane Chemical compound CCCl HRYZWHHZPQKTII-UHFFFAOYSA-N 0.000 description 1
- YACLQRRMGMJLJV-UHFFFAOYSA-N chloroprene Chemical compound ClC(=C)C=C YACLQRRMGMJLJV-UHFFFAOYSA-N 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000010494 dissociation reaction Methods 0.000 description 1
- 230000005593 dissociations Effects 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 229960003750 ethyl chloride Drugs 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- JEGUKCSWCFPDGT-UHFFFAOYSA-N h2o hydrate Chemical compound O.O JEGUKCSWCFPDGT-UHFFFAOYSA-N 0.000 description 1
- 150000002366 halogen compounds Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- RPACBEVZENYWOL-XFULWGLBSA-M sodium;(2r)-2-[6-(4-chlorophenoxy)hexyl]oxirane-2-carboxylate Chemical compound [Na+].C=1C=C(Cl)C=CC=1OCCCCCC[C@]1(C(=O)[O-])CO1 RPACBEVZENYWOL-XFULWGLBSA-M 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Abstract
Description
本発明は、還元反応水溶液中で、還元剤を用いた水酸化第二銅の還元により、粒度分布の狭いナノサイズの銅微粒子の製造方法、及び該製造方法により得られる銅微粒子に関する。 The present invention relates to a method for producing nanosized copper fine particles having a narrow particle size distribution by reduction of cupric hydroxide using a reducing agent in a reduction reaction aqueous solution, and copper fine particles obtained by the production method.
ナノサイズ（粒径が１μｍ以下）の金属、合金等の微粒子は、バルク材料にはない様々な特異な特性を持つことが知られている。そしてこの特性を生かした様々な工学的応用が、現在、エレクトロニクス、バイオ、エネルギー等の各分野で、大いに期待されている。 It is known that nano-sized (particle size is 1 μm or less) fine particles such as metals and alloys have various unique characteristics not found in bulk materials. Various engineering applications that take advantage of this property are now highly expected in various fields such as electronics, biotechnology, and energy.
中でも、銅及びその合金からなるナノサイズの微粒子は、導電回路、バンプ、ビア、パッド等の実装部品の形成材料、高密度磁気記憶媒体やアンテナ用の磁性素子、ガス改質フィルタや燃料電池電極用の触媒材料として、大いに期待されている。 Among them, nano-sized fine particles made of copper and its alloys are used as materials for forming mounting parts such as conductive circuits, bumps, vias, pads, magnetic elements for high-density magnetic storage media and antennas, gas reforming filters and fuel cell electrodes. It is highly expected as a catalyst material.
最近では、銅微粒子を含有するインクを使用して、配線パターンをインクジェット法により形成し、焼成して配線を形成する技術が注目されている。しかし、インクジェット用のインクとして、銅微粒子を含有するインクを使用する場合、インク中において分散性を長期間保つことが重要であり、そのために、インク中において分散性を長期間保つ銅微粒子の製造方法が提案されている。 Recently, attention has been paid to a technique of forming a wiring pattern by an ink jet method using an ink containing copper fine particles and baking it to form a wiring. However, when an ink containing copper fine particles is used as an ink for inkjet, it is important to maintain the dispersibility in the ink for a long time. A method has been proposed.
特許文献１には、ポリエチレングリコール溶液、又はその水溶液中で酸化銅又は銅塩化物を還元して金属銅の微粒子を製造する銅微粒子の製造方法が開示されている。その実施例においては水酸化銅（Ｃｕ（ＯＨ）２）をヒドラジンで還元して、粒子径が２〜６ｎｍの微粒子をえたことが記載されている。
特許文献２には、（ａ）塩化銅（ＣｕＣｌ２）、硝酸銅（Ｃｕ（ＮＯ３）２）、硫酸銅（ＣｕＳＯ４）、酢酸銅（（ＣＨ３ＣＯＯ）２Ｃｕ）、又は水酸化銅（Ｃｕ（ＯＨ）２）等からなる銅前駆体とアミン系化合物とを混合して撹拌する段階、（ｂ）混合溶液を９０ないし１７０℃まで昇温させた後、その温度で反応させる段階、（ｃ）反応終了後、非水系溶媒に前記混合溶液を投入して溶液の温度を２０ないし５０℃に低下させる段階、及び（ｄ）前記混合溶液にアルコール系溶媒を投入してナノ粒子を沈殿させて得る段階、を含むキュービック形態の銅ナノ粒子の製造方法が開示されている。
その実施例にはアセチルアセトナト銅を前記条件で還元して、大きさが約１５ｎｍのキュービック形態の粒子を合成したことが記載されている。
Patent Document 1 discloses a method for producing copper fine particles in which metal oxide fine particles are produced by reducing copper oxide or copper chloride in a polyethylene glycol solution or an aqueous solution thereof. In the examples, it is described that copper hydroxide (Cu (OH) 2 ) was reduced with hydrazine to obtain fine particles having a particle diameter of 2 to 6 nm.
Patent Document 2 includes (a) copper chloride (CuCl 2 ), copper nitrate (Cu (NO 3 ) 2 ), copper sulfate (CuSO 4 ), copper acetate ((CH 3 COO) 2 Cu), or copper hydroxide. A step of mixing and stirring a copper precursor composed of (Cu (OH) 2 ) or the like and an amine compound, (b) a step of raising the temperature of the mixed solution to 90 to 170 ° C., and then reacting at that temperature; (C) After the reaction is completed, the mixed solution is added to a non-aqueous solvent to lower the temperature of the solution to 20 to 50 ° C., and (d) an alcoholic solvent is added to the mixed solution to precipitate nanoparticles. And a method for producing a cubic form of copper nanoparticles.
The example describes that acetylacetonato copper was reduced under the above conditions to synthesize cubic particles having a size of about 15 nm.
特許文献３には、（ａ）塩化銅（ＣｕＣｌ２）、硝酸銅（Ｃｕ（ＮＯ３）２）、硫酸銅（ＣｕＳＯ４）、酢酸銅（（ＣＨ３ＣＯＯ）２Ｃｕ）、アセチルアセトナト銅、又は水酸化銅（Ｃｕ（ＯＨ）２）等の銅塩、分散剤、還元剤及び有機溶媒を含む混合溶液を調製する段階と、（ｂ）前記混合溶液の温度を３０ないし５０℃に昇温させて撹拌する段階と、（ｃ）前記混合溶液にマイクロ波を照射する段階と、及び（ｄ）前記混合溶液の温度を低下させて銅ナノ粒子を得る段階とを含む銅ナノ粒子の製造方法が開示されている。その実施例には硫酸銅を前記条件で還元して、大きさが３０〜５０ｎｍの球状銅粒子を得たことが記載されている。 In Patent Document 3, (a) copper chloride (CuCl 2 ), copper nitrate (Cu (NO 3 ) 2 ), copper sulfate (CuSO 4 ), copper acetate ((CH 3 COO) 2 Cu), acetylacetonato copper Or preparing a mixed solution containing a copper salt such as copper hydroxide (Cu (OH) 2 ), a dispersing agent, a reducing agent and an organic solvent, and (b) raising the temperature of the mixed solution to 30 to 50 ° C. Producing copper nanoparticles comprising: heating and stirring; (c) irradiating the mixed solution with microwaves; and (d) reducing the temperature of the mixed solution to obtain copper nanoparticles. A method is disclosed. The example describes that copper sulfate was reduced under the above conditions to obtain spherical copper particles having a size of 30 to 50 nm.
上記の従来の銅化合物の還元方法においては、得られる銅微粒子の粒子径が大きいか、又は粒度分布の幅が広いとインクジェット用の分散液に添加するとインクジェットのノズルにおいて詰まりが発生し易いばかりでなく、インクの状態で保存すると粒子の凝集が生じてインクの安定性が低下するという問題点があった。このような安定性の低下したインクをインクジェット手段により、基板上にパターニング後、乾燥・焼成すると焼結後の導電性が低下して、所望の導電性配線等を得ることができない。
従って、粒子径が１０ｎｍ以下のナノサイズでかつ、粒度分布の幅の狭い小さい銅微粒子を還元反応水溶液中において高濃度で得る技術の確立が望まれていた。
本発明は、上記問題点を解決し、粒子径が１０ｎｍ以下のナノサイズでかつ、粒度分布幅の狭い銅微粒子の製造方法を提供することを目的とする。
In the conventional copper compound reduction method described above, if the resulting copper fine particles have a large particle size or a wide particle size distribution range, clogging is likely to occur in an inkjet nozzle when added to an inkjet dispersion. However, when stored in the ink state, there is a problem that the aggregation of particles occurs and the stability of the ink is lowered. When such a reduced stability ink is patterned on a substrate by an ink jet means and then dried and fired, the conductivity after sintering is lowered, and a desired conductive wiring or the like cannot be obtained.
Therefore, it has been desired to establish a technique for obtaining high-concentration copper fine particles having a particle size of nanometer of 10 nm or less and a narrow particle size distribution in a reduction reaction aqueous solution.
An object of the present invention is to solve the above-described problems and to provide a method for producing copper fine particles having a nano size of 10 nm or less and a narrow particle size distribution width.
本発明者らは上述した従来の問題点について鋭意研究を重ねた結果、還元反応水溶液中で水溶液中への溶解度が極めて低い水酸化第二銅（Ｃｕ（ＯＨ）２）を原料として用いて、有機分散剤と還元剤である水素化ホウ素ナトリウムの存在下に、未溶解の固体状酸化銅を共存させて還元反応させると上記課題が解決できることを見出し本発明に到達した。 As a result of intensive studies on the above-described conventional problems, the present inventors have used cupric hydroxide (Cu (OH) 2 ) as a raw material having extremely low solubility in an aqueous solution of a reduction reaction, The present inventors have found that the above problems can be solved by coexisting undissolved solid copper oxide in the presence of an organic dispersant and sodium borohydride, which is a reducing agent, to arrive at the present invention.
すなわち本発明は、以下の（１）ないし（９）に記載する発明を要旨とする。
（１）還元反応水溶液中の水酸化第二銅（Ｃｕ（ＯＨ）２）を有機分散剤（Ｄ）と還元剤である水素化ホウ素ナトリウム（ＮａＢＨ４）の存在下に撹拌しながら還元反応させる、銅微粒子の製造方法であって、還元反応中に該水溶液中には水酸化第二銅が溶解して生成する銅イオンと未溶解の水酸化第二銅が共存していて、還元反応の進行により該水溶液中の銅イオンが還元されて銅原子と銅微粒子が生成するのに伴い、前記未溶解の水酸化第二銅が該水溶液中に連続的に溶解して銅イオンが生成して、還元反応が該水溶液中で水酸化第二銅の飽和溶解度ないしそれ以下の濃度で行なわれることを特徴とする、銅微粒子の製造方法（以下、「第１の態様」ということがある）。
（２）前記還元反応水溶液中に添加する水酸化第二銅の量が１５〜１５０ミリモル／リットルであることを特徴とする、前記（１）に記載の銅微粒子の製造方法。
（３）前記還元反応水溶液中の銅イオン（Ｉ）の濃度が５×１０−２ミリモル／リットル以下であることを特徴とする、前記（１）又は（２）に記載の銅微粒子の製造方法。
（４）前記還元反応水溶液に添加する水酸化第二銅の９０質量％以上の平均粒子径が０．１〜１００μｍの範囲内にあることを特徴とする、前記（１）ないし（３）のいずれかに記載の銅微粒子の製造方法。
That is, the gist of the present invention is the invention described in the following (1) to (9).
(1) Reduction reaction The cupric hydroxide (Cu (OH) 2 ) in the aqueous solution is subjected to a reduction reaction with stirring in the presence of the organic dispersant (D) and the reducing agent sodium borohydride (NaBH 4 ). The copper fine particle production method, wherein the aqueous solution contains copper ions dissolved and dissolved in the aqueous solution during the reduction reaction, and undissolved cupric hydroxide coexists. As the copper ions in the aqueous solution are reduced and copper atoms and fine copper particles are generated as the process proceeds, the undissolved cupric hydroxide is continuously dissolved in the aqueous solution to form copper ions. A method for producing copper fine particles, wherein the reduction reaction is carried out in the aqueous solution at a concentration equal to or lower than the saturated solubility of cupric hydroxide (hereinafter, sometimes referred to as “first embodiment”).
(2) The method for producing copper fine particles according to (1) above, wherein the amount of cupric hydroxide added to the aqueous reduction reaction solution is 15 to 150 mmol / liter.
(3) The method for producing copper fine particles according to (1) or (2) above, wherein the concentration of copper ion (I) in the aqueous reduction reaction solution is 5 × 10 −2 mmol / liter or less. .
(4) The average particle size of 90% by mass or more of cupric hydroxide added to the reduction reaction aqueous solution is in the range of 0.1 to 100 μm. The manufacturing method of the copper fine particle in any one.
（５）前記還元反応水溶液中に添加する水素化ホウ素ナトリウムと水酸化第二銅の量との割合［（水素化ホウ素ナトリウム）／（水酸化第二銅）］（モル比）が０．５〜２．０であることを特徴とする、前記（１）ないし（４）のいずれかに記載の銅微粒子の製造方法。
（６）前記有機分散剤（Ｄ）が、ポリビニルピロリドン、ポリエチレンイミン、ポリアクリル酸、カルボキシメチルセルロース、ポリアクリルアミド、ポリビニルアルコール、ポリエチレンオキシド、デンプン、及びゼラチンの中から選択される１種又は２種以上であることを特徴とする、前記（１）ないし（５）のいずれかに記載の銅微粒子の製造方法。
（７）前記還元反応により得られる銅微粒子の平均一次粒子径が４〜８ｎｍで、変動係数が１５％以下であることを特徴とする、前記（１）ないし（６）のいずれかに記載の銅微粒子の製造方法。
(5) Ratio [(sodium borohydride) / (cupric hydroxide)] (molar ratio) of sodium borohydride and cupric hydroxide added to the reduction reaction aqueous solution is 0.5. It is -2.0, The manufacturing method of the copper fine particle in any one of said (1) thru | or (4) characterized by the above-mentioned.
(6) The organic dispersant (D) is one or more selected from polyvinyl pyrrolidone, polyethyleneimine, polyacrylic acid, carboxymethylcellulose, polyacrylamide, polyvinyl alcohol, polyethylene oxide, starch, and gelatin. The method for producing copper fine particles according to any one of (1) to (5) above, wherein
(7) The copper primary particles obtained by the reduction reaction have an average primary particle diameter of 4 to 8 nm and a coefficient of variation of 15% or less, according to any one of (1) to (6), A method for producing copper fine particles.
（８）還元反応水溶液中で有機分散剤（Ｄ）と還元剤である水素化ホウ素ナトリウム（ＮａＢＨ４）の存在下に、水酸化第二銅が溶解して生成する銅イオンと未溶解の水酸化第二銅を共存させた還元反応により得られる、平均一次粒子径が４〜８ｎｍで変動係数が１５％以下であることを特徴とする銅微粒子（以下、「第２の態様」ということがある）。 (8) Copper ions and undissolved water produced by dissolution of cupric hydroxide in the presence of the organic dispersant (D) and sodium borohydride (NaBH 4 ) as the reducing agent in the reduction reaction aqueous solution. Copper fine particles (hereinafter referred to as “second embodiment”) having an average primary particle diameter of 4 to 8 nm and a coefficient of variation of 15% or less, obtained by a reduction reaction in the presence of cupric oxide. is there).
上記（１）及び（３）に記載した本発明の還元反応において、銅微粒子の原料に水酸化第二銅を使用するので、他の銅塩を使用した場合と比較して、銅原子以外には水素原子と酸素原子しか含まれない点から原料銅化合物に由来する不純物が本質的に少ないという特徴がある。又、水酸化第二銅の水溶液中への溶解度が低いことに起因して、還元反応水溶液中で水酸化第二銅が溶解して生成される銅イオン濃度が低い環境下で還元剤により還元されるので、還元反応により、平均一次粒子径が小さく、かつ粒度分布の狭い銅微粒子が安定的に得られる。
上記（２）に記載した本発明の還元反応において、還元反応水溶液中に未溶解の水酸化第二銅を添加できるので、還元反応により、従来よりも単位還元反応溶液当り高収量で銅微粒子を得ることが可能になる。
上記（４）に記載した本発明の還元反応において、還元反応の原料に使用する水酸化第二銅の粒子径を制御することにより、得られる銅微粒子の平均一次粒子径、及び還元反応時間を制御することが可能になる。
In the reduction reaction of the present invention described in the above (1) and (3), since cupric hydroxide is used as the raw material for the copper fine particles, in addition to the case of using other copper salts, in addition to the copper atom, Is characterized in that essentially no impurities are derived from the raw material copper compound because it contains only hydrogen and oxygen atoms. Moreover, due to the low solubility of cupric hydroxide in aqueous solution, it is reduced by a reducing agent in an environment where the concentration of copper ions generated by dissolution of cupric hydroxide in the reduction reaction aqueous solution is low. Therefore, copper fine particles having a small average primary particle size and a narrow particle size distribution can be stably obtained by the reduction reaction.
In the reduction reaction of the present invention described in (2) above, undissolved cupric hydroxide can be added to the aqueous solution of the reduction reaction. It becomes possible to obtain.
In the reduction reaction of the present invention described in the above (4), by controlling the particle size of cupric hydroxide used as a raw material for the reduction reaction, the average primary particle size of the obtained copper fine particles and the reduction reaction time are determined. It becomes possible to control.
上記（５）に記載した本発明の還元反応において、他の金属塩、例えば酢酸銅を使用した場合と比較して、水酸化第二銅は水溶液中でｐＨが相対的に高いので還元剤である水素化ホウ素ナトリウムの分解を押えて、水素化ホウ素ナトリウムの還元機能を効率よく発揮できるので、（水素化ホウ素ナトリウム）／（水酸化第二銅）］（モル比）が０．５〜２．０となる範囲で水酸化第二銅の還元化反応を完了させることが可能になる。
上記（６）に記載した発明において、有機分散剤（Ｄ）は、還元反応により生成した銅微粒子を還元反応水溶液に分散させる機能を発揮するので、還元反応により平均一次粒子径が小さく、かつ粒度分布の狭い銅微粒子を得ることが可能になる。
前記（１）〜（６）に記載した銅微粒子の製造方法により、前記（７）に記載した平均一次粒子径が４〜８μｍで変動係数が１５％以下の銅微粒子が得られる。このような銅微粒子を分散溶液に分散させて得られる銅微粒子分散溶液は、分散安定性に優れるので基板配線用銅インク等に好適に使用することができる。
前記（８）に記載した還元反応を採用すると、平均一次粒子径が４〜８μｍで変動係数が１５％以下の銅微粒子を得ることが可能になるので、このような銅微粒子を分散溶液に分散させて得られる銅微粒子分散溶液は、分散安定性に優れるので、該微粒子を分散溶液に分散させて得られる銅微粒子分散溶液は、配線材料、色材、光学フィルタ、触媒などの機能性材料として均質な性能を得ることができ、さらに、銅微粒子分散溶液焼成温度（３００℃以下）で焼成しても導電性の高い導電材料を得ることが可能である。
In the reduction reaction of the present invention described in the above (5), compared with the case where other metal salt, for example, copper acetate is used, cupric hydroxide has a relatively high pH in an aqueous solution. Since the decomposition function of certain sodium borohydride can be suppressed and the reduction function of sodium borohydride can be efficiently exhibited, (sodium borohydride) / (cupric hydroxide)] (molar ratio) is 0.5-2. The reduction reaction of cupric hydroxide can be completed within the range of 0.0.
In the invention described in the above (6), the organic dispersant (D) exhibits a function of dispersing the copper fine particles generated by the reduction reaction in the reduction reaction aqueous solution, so that the average primary particle size is reduced by the reduction reaction and the particle size is reduced. It becomes possible to obtain copper fine particles having a narrow distribution.
According to the method for producing copper fine particles described in (1) to (6), copper fine particles having an average primary particle diameter of 4 to 8 μm and a coefficient of variation of 15% or less described in (7) are obtained. A copper fine particle dispersion obtained by dispersing such copper fine particles in a dispersion solution is excellent in dispersion stability, and can be suitably used for copper ink for substrate wiring.
When the reduction reaction described in the above (8) is adopted, it becomes possible to obtain copper fine particles having an average primary particle diameter of 4 to 8 μm and a coefficient of variation of 15% or less. Therefore, such copper fine particles are dispersed in a dispersion solution. Since the copper fine particle dispersion obtained by this process is excellent in dispersion stability, the copper fine particle dispersion obtained by dispersing the fine particles in the dispersion is used as a functional material such as a wiring material, a coloring material, an optical filter, and a catalyst. A homogeneous performance can be obtained, and furthermore, a conductive material having high conductivity can be obtained even when fired at a copper fine particle dispersion solution firing temperature (300 ° C. or lower).
以下に〔１〕本発明の「銅微粒子の製造方法」（第１の態様）、及び〔２〕本発明の「銅微粒子」（第２の態様）について説明する。
〔１〕本発明の第１の態様に係る「銅微粒子の製造方法」
本発明の第１の態様に係る「銅微粒子の製造方法」は、還元反応水溶液中の水酸化第二銅（Ｃｕ（ＯＨ）２）を有機分散剤（Ｄ）と還元剤である水素化ホウ素ナトリウム（ＮａＢＨ４）の存在下に撹拌しながら還元反応させる、銅微粒子の製造方法であって、
還元反応中に該水溶液中には水酸化第二銅が溶解して生成する銅イオンと未溶解の水酸化第二銅が共存していて、還元反応の進行により該水溶液中の銅イオンが還元されて銅原子と銅微粒子が生成するのに伴い、前記未溶解の水酸化第二銅が該水溶液中に溶解して銅イオンが連続的に生成してきて、還元反応が該水溶液中で水酸化第二銅の飽和溶解度ないしそれ以下の濃度で行なわれることを特徴とする。
以下、本発明の「銅微粒子の製造方法」について説明する。
[1] The “copper fine particle production method” (first aspect) of the present invention and [2] “copper fine particle” (second aspect) of the present invention will be described below.
[1] “Method for producing copper fine particles” according to the first aspect of the present invention
The “method for producing copper fine particles” according to the first aspect of the present invention includes cupric hydroxide (Cu (OH) 2 ) in a reduction reaction aqueous solution, an organic dispersant (D), and a borohydride as a reducing agent. A method for producing copper fine particles, wherein a reduction reaction is performed with stirring in the presence of sodium (NaBH 4 ),
During the reduction reaction, cupric hydroxide dissolved in the aqueous solution coexists with undissolved cupric hydroxide, and the copper ion in the aqueous solution is reduced by the progress of the reduction reaction. As the copper atoms and copper fine particles are generated, the undissolved cupric hydroxide dissolves in the aqueous solution and copper ions are continuously generated, and the reduction reaction is hydroxylated in the aqueous solution. It is characterized in that it is carried out at a concentration of cupric saturation solubility or lower.
Hereinafter, the “method for producing copper fine particles” of the present invention will be described.
（１）原料として使用する水酸化第二銅、水素化ホウ素ナトリウム、及び有機分散剤（Ｄ）について
（１−１）水酸化第二銅
本発明において、銅微粒子の原料に使用する水酸化第二銅は、青白色粉末または青色結晶で水への溶解度は低く、室温（２５℃程度）で５．８５×１０−５モル／リットル程度である。本発明の「銅微粒子の製造方法」において、還元反応水溶液中で還元剤により銅イオンから銅微粒子を形成させる際に、水酸化第二銅の水溶液中への溶解度が低いことに起因して、還元反応水溶液中に溶解している銅イオンの濃度も低いので、低銅イオン濃度から銅微粒子が形成される際に粒子径が小さく、かつ粒度分布の狭い銅微粒子が安定的に得られる。
水酸化第二銅は、粒子状のもの、また粒子状のものを粉砕して微粒子状にしたものを用いることができる。
水酸化第二銅の水溶液中への溶解速度は遅いので、粉砕により粒子径の小さい水酸化第二銅を使用することにより、還元反応を促進すると共に一次粒子径を相対的に大きくすることが可能になる。微粒子状の水酸化第二銅を使用する場合、その９０質量％以上の平均粒子径は、０．１〜１００μｍが好ましい。平均粒子径が１００μｍを超えると水酸化第二銅の還元反応水溶液中への溶解速が低下して該水溶液中の銅イオン濃度が低下して、還元反応に要する時間が長くなるおそれがある。
水酸化第二銅の粉砕は、乾式ボール微粉砕や湿式微粉砕により行うことができるが、不純物の混入を避けるためにセラミック微粉砕機、セラミックボール微粉砕媒体等を用いて清浄な環境中で実施することが望ましい。
(1) About cupric hydroxide, sodium borohydride, and organic dispersant (D) used as raw materials (1-1) Cupric hydroxide In the present invention, hydroxide hydroxide used as a raw material for copper fine particles Dicopper is a bluish white powder or blue crystal with low solubility in water, and is about 5.85 × 10 −5 mol / liter at room temperature (about 25 ° C.). In the “method for producing copper fine particles” of the present invention, when forming copper fine particles from copper ions with a reducing agent in a reduction reaction aqueous solution, due to the low solubility in aqueous solution of cupric hydroxide, Since the concentration of copper ions dissolved in the reduction reaction aqueous solution is also low, copper fine particles having a small particle size and a narrow particle size distribution can be stably obtained when copper fine particles are formed from a low copper ion concentration.
The cupric hydroxide may be in the form of particles or particles obtained by pulverizing particles.
Since the dissolution rate of cupric hydroxide in an aqueous solution is slow, by using cupric hydroxide with a small particle size by pulverization, the reduction reaction can be promoted and the primary particle size can be made relatively large. It becomes possible. When using fine cupric hydroxide, the average particle diameter of 90% by mass or more is preferably 0.1 to 100 μm. When the average particle diameter exceeds 100 μm, the dissolution rate of cupric hydroxide in the reduction reaction aqueous solution is lowered, the copper ion concentration in the aqueous solution is lowered, and the time required for the reduction reaction may be increased.
Cupric hydroxide can be pulverized by dry ball pulverization or wet pulverization, but in a clean environment using a ceramic pulverizer, ceramic ball pulverization media, etc. to avoid contamination by impurities. It is desirable to implement.
（１−２）水素化ホウ素ナトリウム
本発明において還元剤として用いる水素化ホウ素ナトリウムは、還元剤として種々の物質の還元に広く使用されている。水素化ホウ素ナトリウムは、酸性、又は中性の水溶液中で分解して水素を発生するので、還元反応水溶液に水素化ホウ素ナトリウムを添加する際、予め該水溶液に塩基性化合物を添加してアルカリ性としておくか、又は、予め水素化ホウ素ナトリウムをｐＨ１０．５〜１３の水溶液に溶解したものを還元反応水溶液に添加してもよい。添加する塩基性化合物としては、例えば、水酸化ナトリウム、水酸化カリウム、水酸化カルシウム等のアルカリ金属又はアルカリ土類金属の水酸化物や炭酸塩、アンモニア等のアンモニウム化合物、アミン類等の塩基性化合物を挙げることができる。
(1-2) Sodium borohydride Sodium borohydride used as a reducing agent in the present invention is widely used as a reducing agent for the reduction of various substances. Since sodium borohydride decomposes in an acidic or neutral aqueous solution to generate hydrogen, when adding sodium borohydride to the reduction reaction aqueous solution, a basic compound is added to the aqueous solution in advance to make it alkaline. Alternatively, a solution obtained by dissolving sodium borohydride in an aqueous solution having a pH of 10.5 to 13 in advance may be added to the aqueous reduction reaction solution. As the basic compound to be added, for example, alkali metal or alkaline earth metal hydroxide or carbonate such as sodium hydroxide, potassium hydroxide or calcium hydroxide, ammonium compound such as ammonia, basic such as amines, etc. A compound can be mentioned.
（１−３）有機分散剤（Ｄ）
有機分散剤（Ｄ）は、還元反応により生成する銅イオンに配位して銅原子への還元反応を促進すると共に、該銅原子から形成される銅粒子表面に配位して、銅微粒子を水溶液中に均一に分散させる機能も有している。特に、還元反応水溶液中に多量の水酸化銅を添加する場合、平均一次粒子径を小さく、かつ粒度分布の狭い銅微粒子を得るために、該水溶液中で生成する銅微粒子を分散させる機能を発揮する分散剤の添加は重要である。
有機分散剤（Ｄ）として好ましいのは、ポリビニルピロリドン、ポリエチレンイミン等のアミン系の高分子；ポリアクリル酸、カルボキシメチルセルロース等のカルボン酸基を有する炭化水素系高分子；ポリアクリルアミド等のアクリルアミド；ポリビニルアルコール、ポリエチレンオキシド、更にはデンプン、及びゼラチンの中から選択される１種又は２種以上である。
上記例示した有機分散剤（Ｄ）の具体例として、ポリビニルピロリドン（分子量：１０００〜５００、０００）、ポリエチレンイミン（分子量：１００〜１００，０００）、カルボキシメチルセルロース（アルカリセルロースのヒドロキシル基Ｎａ塩のカルボキシメチル基への置換度：０．４以上、分子量：１０００〜１００，０００）、ポリアクリルアミド（分子量：１００〜６，０００，０００）、ポリビニルアルコール（分子量：１０００〜１００，０００）、ポリエチレングリコール（分子量：１００〜５０，０００）、ポリエチレンオキシド（分子量：５０，０００〜９００，０００）、ゼラチン（平均分子量：６１，０００〜６７，０００）、水溶性のデンプン等の高分子の有機分散剤（Ｄ）が挙げられる。
(1-3) Organic dispersant (D)
The organic dispersant (D) promotes the reduction reaction to copper atoms by coordinating to the copper ions generated by the reduction reaction, and coordinates to the surface of the copper particles formed from the copper atoms. It also has a function of uniformly dispersing in an aqueous solution. In particular, when a large amount of copper hydroxide is added to the reduction reaction aqueous solution, it exhibits a function to disperse the copper fine particles generated in the aqueous solution in order to obtain copper fine particles having a small average primary particle size and a narrow particle size distribution. The addition of dispersing agents is important.
The organic dispersant (D) is preferably an amine polymer such as polyvinylpyrrolidone or polyethyleneimine; a hydrocarbon polymer having a carboxylic acid group such as polyacrylic acid or carboxymethylcellulose; an acrylamide such as polyacrylamide; One or more selected from among alcohol, polyethylene oxide, starch, and gelatin.
Specific examples of the organic dispersant (D) exemplified above include polyvinylpyrrolidone (molecular weight: 1000 to 500,000), polyethyleneimine (molecular weight: 100 to 100,000), carboxymethyl cellulose (carboxyl of hydroxyl group Na salt of alkali cellulose). Degree of substitution to methyl group: 0.4 or more, molecular weight: 1000 to 100,000, polyacrylamide (molecular weight: 100 to 6,000,000), polyvinyl alcohol (molecular weight: 1000 to 100,000), polyethylene glycol ( Molecular weight: 100 to 50,000), polyethylene oxide (molecular weight: 50,000 to 900,000), gelatin (average molecular weight: 61,000 to 67,000), high molecular organic dispersants such as water-soluble starch ( D).
上記かっこ内にそれぞれの高分子の有機分散剤（Ｄ）の数平均分子量を示すが、このような分子量範囲にあるものは水溶性を有するので、本発明において好適に使用できる。尚、これらの２種以上を混合して使用することもできる。
また、有機分散剤（Ｄ）の添加量は、還元反応水溶液から生成する銅微粒子の濃度にもよるが、該銅原子１００重量部に対して、１〜１００重量部が好ましく、５〜１００重量部がより好ましい。有機分散剤（Ｄ）の添加量が前記１未満では凝集を抑制する効果が十分に得られない場合があり、一方、前記１００重量部を超える場合には、分散上に支障がなくとも還元反応終了後に凝集促進剤を添加して有機分散剤（Ｄ）を除去する際に不都合が生ずるおそれがある。
The number average molecular weight of each polymeric organic dispersant (D) is shown in the parentheses, and those having such a molecular weight range are water-soluble and can be used preferably in the present invention. In addition, these 2 or more types can also be mixed and used.
Moreover, although the addition amount of an organic dispersing agent (D) is based also on the density | concentration of the copper fine particle produced | generated from reduction reaction aqueous solution, 1-100 weight part is preferable with respect to 100 weight part of this copper atom, and 5-100 weight. Part is more preferred. When the amount of the organic dispersant (D) added is less than 1, the effect of suppressing aggregation may not be sufficiently obtained. On the other hand, when the amount exceeds 100 parts by weight, the reduction reaction is performed even if there is no problem in dispersion. When the aggregation promoter is added after the completion to remove the organic dispersant (D), inconvenience may occur.
（２）水酸化第二銅の水素化ホウ素ナトリウムによる還元について
（２−１）還元反応水溶液
本発明の銅微粒子の製造方法に使用する、還元反応水溶液には、少なくとも、前記水酸化第二銅、水素化ホウ素ナトリウム、及び有機分散剤（Ｄ）が含有され、更に水素化ホウ素ナトリウムの安定剤として、ｐＨがｐＨ１０．５〜１３程度に調整されるように塩基性化合物が添加されている。該還元反応水溶液に添加される水酸化第二銅は該水溶液中で１５〜１５０ミリモル／リットルとなる範囲が望ましい。前記１５ミリモル／リットル以上で還元反応水溶液中での銅微粒子の生産性を向上することができ、一方、前記１５０ミリモル／リットルを超えると還元反応水溶液における撹拌が困難になるおそれがある。
還元反応水溶液に添加される水素化ホウ素ナトリウムの量は、水素化ホウ素ナトリウムと水酸化第二銅の量との割合［（水素化ホウ素ナトリウム）／（水酸化第二銅）］（モル比）が好ましくは０．５〜２．０であり、より好ましくは０．５〜１．０である。
水酸化第二銅に対する水素化ホウ素ナトリウムの添加量が、前記モル比０．５未満では還元反応が充分に進行しないおそれがあり、一方、前記モル比２．０を超えると未反応の水素化ホウ素ナトリウムから大量の水素が発生し、またナトリウムイオンが大量に混入するという不都合を生ずるおそれがある。
(2) Reduction of cupric hydroxide with sodium borohydride (2-1) Reduction reaction aqueous solution The reduction reaction aqueous solution used in the method for producing copper fine particles of the present invention includes at least the cupric hydroxide. , Sodium borohydride, and organic dispersant (D) are contained, and a basic compound is added as a sodium borohydride stabilizer so that the pH is adjusted to about pH 10.5-13. The cupric hydroxide added to the reduction reaction aqueous solution is preferably in the range of 15 to 150 mmol / liter in the aqueous solution. The productivity of the copper fine particles in the reduction reaction aqueous solution can be improved at 15 mmol / liter or more, whereas if it exceeds 150 mmol / liter, stirring in the reduction reaction aqueous solution may be difficult.
The amount of sodium borohydride added to the reduction reaction aqueous solution is the ratio of sodium borohydride to cupric hydroxide [(sodium borohydride) / (cupric hydroxide)] (molar ratio). Is preferably 0.5 to 2.0, more preferably 0.5 to 1.0.
If the amount of sodium borohydride added to cupric hydroxide is less than 0.5 molar ratio, the reduction reaction may not proceed sufficiently. On the other hand, if the molar ratio exceeds 2.0, unreacted hydrogenation may occur. There is a risk that a large amount of hydrogen is generated from sodium boron and that a large amount of sodium ions are mixed.
前記還元反応水溶液中への水素化ホウ素ナトリウムの安定剤である塩基性化合物の添加量が５０ミリモル／リットル以上が好ましく、また該塩基性化合物と銅イオンの濃度比（［塩基性化合物］／［銅イオン］）（モル比）は４．７以上が好ましい。
還元反応水溶液中において、安定剤である塩基性化合物が上記範囲にある場合に還元反応により銅微粒子の生成が容易になる。
又、前記還元反応水溶液中の（［ＢＨ４−］／［Ｃｕ２＋］）（モル比）は０．２以上が好ましく、かつ（［ＯＨ―］／［Ｃｕ２＋］）／（［ＢＨ４−］／［Ｃｕ２＋］）が３．２以上であることが好ましい。還元反応水溶液中において、［ＢＨ４−］、［Ｃｕ２＋］、及び［ＯＨ―］がかかる割合で存在する場合に還元反応により銅微粒子の生成が容易になる。
The addition amount of the basic compound that is a stabilizer of sodium borohydride to the aqueous solution of the reduction reaction is preferably 50 mmol / liter or more, and the concentration ratio of the basic compound and copper ion ([basic compound] / [ Copper ion]) (molar ratio) is preferably 4.7 or more.
In the reduction reaction aqueous solution, when the basic compound as a stabilizer is in the above range, the formation of copper fine particles is facilitated by the reduction reaction.
In addition, ([BH 4 − ] / [Cu 2+ ]) (molar ratio) in the reduction reaction aqueous solution is preferably 0.2 or more, and ([OH − ] / [Cu 2+ ]) / ([BH 4− ] / [Cu 2+ ]) is preferably 3.2 or more. When [BH 4− ], [Cu 2+ ], and [OH − ] are present in such a ratio in the reduction reaction aqueous solution, the formation of copper fine particles is facilitated by the reduction reaction.
（２−２）還元反応
少なくとも水酸化第二銅、有機分散剤（Ｄ）、及び還元剤の水素化ホウ素ナトリウムが添加された還元反応水溶液に好ましくは不活性ガスを通気しながら、撹拌下に還元反応を進行させる。
前記不活性ガスとしては、窒素、アルゴン、ヘリウムからなる群より選択される一種類以上であることが望ましい。また、前記還元時の還元反応水溶液温度は６０℃以下であることが好ましく、４０℃以下がより好ましく、１０〜３０℃が更に好ましい。
還元反応は、以下の経路で進行するものと推定される。先ず、水酸化第二銅が還元反応水溶液に溶解して銅イオンが形成され、次に、水素化ホウ素ナトリウムが解離して生成した［ＢＨ４＋］により該銅イオンが還元されて銅原子を生成し、さらに該水溶液で銅原子が過飽和状態になると銅微粒子が生成する。生成した銅微粒子には有機分散剤（Ｄ）が配位して還元反応水溶液中に分散して存在する。
還元反応が進行している間は、前記［ＢＨ４＋］が還元剤として作用した後は水素ガスとして還元反応水溶液から放出されていく。従って、還元反応の終了は水素ガスの発生が止まることにより確認できる。
還元反応時間は、原料の水酸化第二銅の粒子径が小さいほど、短縮される傾向にあることから、該還元反応において、水酸化第二銅が還元反応水溶液中に溶解して銅イオンが形成される工程が律速段階になっていると想定される。
(2-2) Reductive reaction While stirring, while preferably ventilating an inert gas, the aqueous reductive reaction solution to which at least cupric hydroxide, the organic dispersant (D), and the reducing agent sodium borohydride are added is preferably used. The reduction reaction proceeds.
The inert gas is preferably at least one selected from the group consisting of nitrogen, argon, and helium. Moreover, it is preferable that the temperature of the reduction reaction aqueous solution at the time of the reduction is 60 ° C or less, more preferably 40 ° C or less, and further preferably 10 to 30 ° C.
The reduction reaction is presumed to proceed by the following route. First, cupric hydroxide is dissolved in the reduction reaction aqueous solution to form copper ions, and then the copper ions are reduced by [BH 4+ ] generated by dissociation of sodium borohydride to generate copper atoms. Further, when the copper atom becomes supersaturated with the aqueous solution, copper fine particles are generated. An organic dispersant (D) is coordinated to the produced copper fine particles and dispersed in the aqueous reduction reaction solution.
While the reduction reaction proceeds, after [BH 4+ ] acts as a reducing agent, it is released from the reduction reaction aqueous solution as hydrogen gas. Therefore, the completion of the reduction reaction can be confirmed by stopping the generation of hydrogen gas.
Since the reduction reaction time tends to be shortened as the particle size of cupric hydroxide as a raw material is smaller, in the reduction reaction, cupric hydroxide is dissolved in the reduction reaction aqueous solution and copper ions are dissolved. It is assumed that the process to be formed is at the rate-determining stage.
（３）銅微粒子の回収
還元反応の終了は、水酸化第二銅を還元するのに必要な量を超える量の水素化ホウ素ナトリウムを添加した場合には、前述の通り還元反応水溶液からの水素の発生の終了で確認することが可能である。この場合、還元反応水溶液中に添加した水酸化第二銅中の銅原子のほぼ全量が還元されて銅微粒子を形成する。
尚、還元反応水溶液中に添加した水酸化第二銅中の銅の全量が還元されない条件の場合には、還元反応終了後に、還元反応水溶液中の攪拌を停止すれば、未反応の水酸化第二銅が存在している場合には、該水溶液の底部に水酸化第二銅が沈降してくるので、未反応の水酸化第二銅は容易に系外に除去することが可能である。
還元反応水溶液に分散している銅微粒子は、凝集剤を添加して銅微粒子を凝集させて回収することができる。凝集剤としては、常温又は操作温度で液状又は気体上であり、還元反応後に水溶液に添加することにより、微粒子を凝集等させ、かつ有機分散剤（Ｄ）を析出させないものであればとくに限定されるものではないが、好適な例として、アセトン、ハロゲン系炭化水素等を挙げることができる。該ハロゲン系炭化水素としては、炭素原子数１〜４の塩素化合物、臭素化合物、等のハロゲン化合物、塩素系、臭素系のハロゲン系芳香族化合物が好ましい。
(3) Recovery of copper fine particles When the reduction reaction is completed, when an amount of sodium borohydride exceeding the amount necessary for reducing cupric hydroxide is added, hydrogen from the reduction reaction aqueous solution is added as described above. Can be confirmed at the end of the occurrence of. In this case, almost all of the copper atoms in the cupric hydroxide added to the reduction reaction aqueous solution are reduced to form copper fine particles.
In the condition where the total amount of copper in the cupric hydroxide added to the reduction reaction aqueous solution is not reduced, after the reduction reaction is completed, if the stirring in the reduction reaction aqueous solution is stopped, When cupric is present, cupric hydroxide precipitates at the bottom of the aqueous solution, so unreacted cupric hydroxide can be easily removed out of the system.
The copper fine particles dispersed in the reduction reaction aqueous solution can be collected by adding a flocculant to aggregate the copper fine particles. The flocculant is not particularly limited as long as it is liquid or gas at normal temperature or operating temperature, and is added to the aqueous solution after the reduction reaction so that the fine particles are aggregated and the organic dispersant (D) is not precipitated. Although not intended, preferred examples include acetone, halogenated hydrocarbons, and the like. As the halogenated hydrocarbon, halogen compounds such as chlorine compounds and bromine compounds having 1 to 4 carbon atoms, and chlorine-based and bromine-based halogenated aromatic compounds are preferable.
前記凝集剤の具体例として、塩化メチル、塩化メチレン、クロロホルム）、四塩化炭素等の炭素原子数１の塩素化合物；塩化エチル、１，１−ジクロルエタン、１，２−ジクロルエタン、１，１−ジクロルエチレン、１，２−ジクロルエチレン、トリクロルエチレン、四塩化アセチレン、エチレンクロロヒドリン等の炭素原子数２の塩素化合物；１，２−ジクロルプロパン、塩化アリル等の炭素原子数３の塩素系化合物；クロロプレン等の炭素原子数４の塩素系化合物；クロルベンゼン、塩化ベンジル、ｏ−ジクロルベンゼン、ｍ−ジクロルベンゼン、ｐ−ジクロルベンゼン、α−クロルナフタリン、β−クロルナフタリン等の芳香族系塩素系化合物；ブロモホルム、ブロムベンゾール等の臭素系化合物；並びにヘキサン（Ｃ６Ｈ１４）、及びシクロヘキサン（Ｃ６Ｈ１２）等の炭素数６の炭化水素、の中から選択された少なくとも１種が例示できる。
このような凝集剤（Ｃ１）の添加量は、還元反応により形成される、銅微粒子に対して、（［凝集剤（モル）］／［微粒子（ｇ）］）比で、０．０１以上が好ましく、上限に特に制限はないが、実用的な面から０．０１〜５０がより好ましく、０．１〜２０が更に好ましい。前記配合比が０．０１未満では添加効果が十分に発揮されないおそれがある。
Specific examples of the flocculant include chlorine compounds having 1 carbon atom such as methyl chloride, methylene chloride, chloroform) and carbon tetrachloride; ethyl chloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-dichloro Chlorine compounds having 2 carbon atoms such as chloroethylene, 1,2-dichloroethylene, trichloroethylene, acetylene tetrachloride, ethylene chlorohydrin; chlorines having 3 carbon atoms such as 1,2-dichloropropane and allyl chloride Compounds such as chloroprene, chlorobenzene, chlorobenzene, chlorobenzene, benzyl chloride, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, α-chloronaphthalene, β-chloronaphthalene, etc. aromatic chlorine compounds; bromoform, bromine compounds such as bromine benzol; and hexane (C 6 H 14), Fine cyclohexane (C 6 H 12) 6 carbons, such as hydrocarbons, at least one selected from among may be exemplified.
The amount of the flocculant (C1) added is 0.01 or more in a ratio of ([flocculant (mol)] / [fine particles (g)]) to the copper fine particles formed by the reduction reaction. Preferably, the upper limit is not particularly limited, but 0.01 to 50 is more preferable and 0.1 to 20 is more preferable from a practical aspect. If the blending ratio is less than 0.01, the effect of addition may not be sufficiently exhibited.
還元反応水溶液中から、未反応の水酸化第二銅を前記方法等により除去後、銅微粒子が分散されている水溶液に例えば凝集剤として比重が水よりも大きいクロロホルムを添加した場合には、撹拌後にデカンテーションすると、水相からなる上相と、凝集剤からなる下相の２相に分離し、微粒子は上相である水相の下部に凝集等している状態で存在する。尚、凝集剤の比重が水よりも小さい場合には、撹拌後に上相が凝集剤相で下相が水相となり、この場合にも金属微粒子は水相の下部に凝集等している状態で存在する場合がある。従って、添加した凝集剤は静置することにより水溶液と分離するので、銅微粒子から凝集剤を効率よく除去することができる。凝集剤を添加、撹拌後の凝集又は沈殿状態には水相の下部に微粒子が濃縮されて浮いている状態も含まれる。
尚、銅微粒子が分散している水溶液中に凝集剤を添加して撹拌し、該微粒子を凝集又は沈殿させた後、水溶液から該凝集又は沈殿した微粒子をろ過等の操作により分離して、銅微粒子を得る際に、該ろ過等の分離・回収操作のみでは銅微粒子から有機分散剤（Ｄ）が十分に除去できない場合には、水溶液から微粒子を分離した後に更に銅微粒子を炭素原子数が１〜７程度のアルコール等の溶剤により洗浄することができる。 かくして還元反応水溶液から銅微粒子を回収することができる。
After removing unreacted cupric hydroxide from the reduction reaction aqueous solution by the above method, etc., when chloroform having a specific gravity greater than water is added as an aggregating agent to the aqueous solution in which the copper fine particles are dispersed, stirring is performed. When it is later decanted, it is separated into two phases, an upper phase composed of an aqueous phase and a lower phase composed of an aggregating agent, and the fine particles are present in a state of being aggregated in the lower portion of the aqueous phase that is the upper phase. When the specific gravity of the flocculant is smaller than that of water, after stirring, the upper phase is the flocculant phase and the lower phase is the aqueous phase. In this case, the metal fine particles are also aggregated in the lower part of the aqueous phase. May exist. Therefore, since the added flocculant is separated from the aqueous solution by standing, the flocculant can be efficiently removed from the copper fine particles. The state of aggregation or precipitation after adding a flocculant and stirring includes a state where fine particles are concentrated and floated below the aqueous phase.
The flocculant is added to the aqueous solution in which the copper fine particles are dispersed and stirred, and the fine particles are agglomerated or precipitated, and then the agglomerated or precipitated fine particles are separated from the aqueous solution by an operation such as filtration. When obtaining the fine particles, if the organic dispersant (D) cannot be sufficiently removed from the copper fine particles only by the separation / collection operation such as filtration, the copper fine particles have 1 carbon atom after the fine particles are separated from the aqueous solution. It can be washed with a solvent such as about 7 to alcohol. Thus, copper fine particles can be recovered from the reduction reaction aqueous solution.
（４）還元反応により得られる銅微粒子の形状
前記還元反応により得られる銅微粒子の形状は、平均一次粒子径４〜８ｎｍで変動係数１５％以下である。
ここで、「平均一次粒子径」は、透過電子顕微鏡（ＴＥＭ）（例えば、日本電子（株）製、型式：ＪＥＦ−３１００Ｆ）による観察から測定される銅微粒子の一次粒子径の単純平均値である。
「変動係数」は、一次粒子の標準偏差値を上記平均一次粒子径で除した値である。
変動係数＝（標準偏差）／（平均一次粒子径）
また、前記還元反応により得られる銅微粒子のモード径は、５．０〜８．０ｎｍである。ここでモード径とは、粒子分布の最大値を示す値である。
尚、該銅微粒子の粒度分布等については、下記の「第２の態様に係る銅微粒子」の項で記載する。
(4) Shape of copper fine particles obtained by reduction reaction The shape of copper fine particles obtained by the reduction reaction has an average primary particle diameter of 4 to 8 nm and a variation coefficient of 15% or less.
Here, the “average primary particle diameter” is a simple average value of primary particle diameters of copper fine particles measured from observation with a transmission electron microscope (TEM) (for example, JEOL Ltd., model: JEF-3100F). is there.
“Variation coefficient” is a value obtained by dividing the standard deviation value of primary particles by the average primary particle size.
Coefficient of variation = (standard deviation) / (average primary particle size)
Further, the mode diameter of the copper fine particles obtained by the reduction reaction is 5.0 to 8.0 nm. Here, the mode diameter is a value indicating the maximum value of the particle distribution.
The particle size distribution and the like of the copper fine particles are described in the section “Copper fine particles according to the second aspect” below.
〔２〕本発明の第２の態様に係る「銅微粒子」
本発明の第２の態様に係る「銅微粒子」は、還元反応水溶液中で有機分散剤（Ｄ）と還元剤である水素化ホウ素ナトリウム（ＮａＢＨ４）の存在下に、水酸化第二銅が溶解して生成する銅イオンと未溶解の水酸化第二銅を共存させた還元反応により得られ、平均一次粒子径が４〜８ｎｍで変動係数が１５％以下であることを特徴とする。
（１）第２の態様における水酸化第二銅の還元反応について
還元反応は、還元反応水溶液中で有機分散剤（Ｄ）と還元剤である水素化ホウ素ナトリウム（ＮａＢＨ４）の存在下に、水酸化第二銅が溶解して生成する銅イオンと未溶解の水酸化第二銅を共存させた還元反応であり、有機分散剤（Ｄ）、水素化ホウ素ナトリウム、及び水酸化第二銅については、第１の態様に記載した通りである。
前述の通り、第１の態様の「銅微粒子の製造方法」において、銅微粒子の原料に水酸化第二銅を使用するので、水酸化第二銅の水溶液中への溶解度が低いことに起因して、還元反応水溶液中で水酸化第二銅が溶解して生成される銅イオン濃度が低い環境下で還元剤により還元されるので、還元反応により、以下に記載する平均一次粒子径が４〜８ｎｍで変動係数が１５％以下である粒度分布の狭い銅微粒子が安定的に得られる。
[2] “Copper fine particles” according to the second aspect of the present invention
The “copper fine particles” according to the second aspect of the present invention are prepared by adding cupric hydroxide in the reduction reaction aqueous solution in the presence of the organic dispersant (D) and sodium borohydride (NaBH 4 ) as the reducing agent. It is obtained by a reduction reaction in which copper ions generated by dissolution and undissolved cupric hydroxide coexist, and has an average primary particle diameter of 4 to 8 nm and a coefficient of variation of 15% or less.
(1) Regarding the reduction reaction of cupric hydroxide in the second embodiment The reduction reaction is carried out in the presence of the organic dispersant (D) and the reducing agent sodium borohydride (NaBH 4 ) in the reduction reaction aqueous solution. It is a reduction reaction in which copper ions generated by dissolution of cupric hydroxide and undissolved cupric hydroxide coexist, and the organic dispersant (D), sodium borohydride, and cupric hydroxide Is as described in the first embodiment.
As described above, in the “method for producing copper fine particles” according to the first aspect, cupric hydroxide is used as a raw material for the copper fine particles, so that the solubility of cupric hydroxide in an aqueous solution is low. Thus, since the cupric hydroxide dissolved in the reduction reaction aqueous solution is reduced by the reducing agent in an environment where the concentration of copper ions is low, the average primary particle size described below is 4 to 4 by the reduction reaction. Copper fine particles having a narrow particle size distribution with a coefficient of variation of 15% or less at 8 nm can be stably obtained.
（２）銅微粒子
第２の態様に係る、銅微粒子の平均一次粒子径は４〜８ｎｍで変動係数は１５％以下である。
還元反応水溶液中で還元剤である水素化ホウ素ナトリウム（ＮａＢＨ４）の存在下に還元する際に銅微粒子の原料として従来広く知られている、水溶液中への溶解度の高い酢酸銅等を使用した場合と比較して、水酸化第二銅を使用すると、特に粒度分布の狭い銅微粒子が安定的に得られることが特徴である。
尚、水酸化第二銅の水溶液への溶解度は、５．８５×１０−５モル／リットルであり、酢酸の水溶液への溶解度は、３．９６×１０−１モル／リットルであるので、水酸化第二銅を原料に使用すると還元反応水溶液中の銅イオン濃度が酢酸銅を原料に使用した場合と比較して、極めて低い濃度であることがわかる。
酢酸銅を原料に用いる場合、還元反応で得られる銅微粒子の粒度分布としての変動係数は３０％以上となるのに対し、水酸化第二銅を原料に使用すると得られる銅微粒子の変動係数が１５％以下となることは特徴的なことである。
平均一次粒子径が１０ｎｍ以下でかつ粒度分布としての変動係数が１５％以下の銅微粒子を分散溶液に分散すると、分散安定性に優れる微粒子分散溶液が得られる。
(2) Copper fine particles According to the second aspect, the average primary particle diameter of the copper fine particles is 4 to 8 nm and the coefficient of variation is 15% or less.
When reducing in the presence of the reducing agent sodium borohydride (NaBH 4 ) in the reduction reaction aqueous solution, copper acetate having a high solubility in an aqueous solution, which has been widely known as a raw material for copper fine particles, was used. Compared to the case, the use of cupric hydroxide is characterized in that copper fine particles having a particularly narrow particle size distribution can be obtained stably.
The solubility of cupric hydroxide in an aqueous solution is 5.85 × 10 −5 mol / liter, and the solubility of acetic acid in an aqueous solution is 3.96 × 10 −1 mol / liter. It can be seen that when cupric oxide is used as the raw material, the copper ion concentration in the aqueous reduction reaction solution is extremely low compared to the case where copper acetate is used as the raw material.
When copper acetate is used as the raw material, the coefficient of variation as the particle size distribution of the copper fine particles obtained by the reduction reaction is 30% or more, whereas the coefficient of variation of the copper fine particles obtained when cupric hydroxide is used as the raw material is It is characteristic that it becomes 15% or less.
When copper fine particles having an average primary particle diameter of 10 nm or less and a coefficient of variation as a particle size distribution of 15% or less are dispersed in a dispersion solution, a fine particle dispersion solution having excellent dispersion stability is obtained.
例えば、還元反応水溶液中で水素化ホウ素ナトリウム（ＮａＢＨ４）の存在下に還元する際に原料として粒度範囲０．１〜１００μｍの水酸化第二銅粒子を使用すると、平均一次粒子径が１０ｎｍ以下の銅微粒子が得られる。尚、水酸化第二銅粒子の粒度範囲が相対的に大きい方が還元反応により得られる銅微粒子の平均一次粒子径とモード径は小さくなると共に、還元反応時間は長くなる傾向がある。しかしながら、原料として、水酸化第二銅粒子を使用すれば、水素化ホウ素ナトリウムによる還元反応により得られる銅微粒子の変動係数は殆どの場合に１５％以下となることは本発明で得られる顕著な効果である。 For example, when cupric hydroxide particles having a particle size range of 0.1 to 100 μm are used as a raw material when reducing in the presence of sodium borohydride (NaBH 4 ) in an aqueous reduction reaction solution, the average primary particle size is 10 nm or less. Of copper fine particles can be obtained. Note that when the particle size range of the cupric hydroxide particles is relatively large, the average primary particle diameter and mode diameter of the copper fine particles obtained by the reduction reaction tend to be small and the reduction reaction time tends to be long. However, if cupric hydroxide particles are used as the raw material, the coefficient of variation of the copper fine particles obtained by the reduction reaction with sodium borohydride is almost 15% or less in most cases. It is an effect.
銅微粒子分散溶液を基板上に塗布（パターニング）して、乾燥後、イナートガス雰囲気下で焼結して得られ導電材料を形成する際に、粒子分散溶液中の銅微粒子の平均一次粒子径が４〜８ｎｍで変動係数が１５％以下であると、分散溶液中での保存安定性に優れ、かつ低い焼成温度で焼成しても得られる導電材料は高い導電性を有することが期待できる。
このように、水酸化第二銅を原料に使用すると平均一次粒子径が１０ｎｍ以下で、変動係数が１５％以下である銅微粒子が安定的に得られることは、下記の実施例、比較例において確認されている。
When forming a conductive material obtained by coating (patterning) a copper fine particle dispersion on a substrate, drying and then sintering in an inert gas atmosphere, the average primary particle diameter of the copper fine particles in the particle dispersion is 4 When the coefficient of variation is 15% or less at ˜8 nm, the conductive material obtained by firing at a low firing temperature is excellent in storage stability in the dispersion solution and can be expected to have high conductivity.
Thus, when cupric hydroxide is used as a raw material, copper fine particles having an average primary particle diameter of 10 nm or less and a coefficient of variation of 15% or less can be stably obtained in the following Examples and Comparative Examples. It has been confirmed.
次に、実施例により本発明をより具体的に説明する。尚、本発明はこれらの実施例に限定されるものではない。
以下の実施例、比較例において、微粒子分散液中の一次粒子の平均粒径は、透過電子顕微鏡（ＴＥＭ）（日本電子（株）製、型式：ＪＥＦ−３１００Ｆ）による観察から求めた。
水酸化第二銅試薬１級品を使用した。実施例１においては試薬をそのまま使用し、実施例２、３においては乳鉢内でそれぞれ１５分間、３０分間該試薬を粉砕したものを使用した。
酢酸銅は、試薬１級品を使用した。
Next, the present invention will be described more specifically with reference to examples. The present invention is not limited to these examples.
In the following examples and comparative examples, the average particle size of primary particles in the fine particle dispersion was determined from observation with a transmission electron microscope (TEM) (manufactured by JEOL Ltd., model: JEF-3100F).
A cupric hydroxide reagent grade 1 product was used. In Example 1, the reagent was used as it was, and in Examples 2 and 3, the reagent was pulverized in a mortar for 15 minutes and 30 minutes, respectively.
As the copper acetate, a reagent first grade product was used.
［実施例１］
（１）還元反応水溶液の調製と還元反応
ポリビニルピロリドン（ＰＶＰ、数平均分子量約３５００）１０ｇを蒸留水１９７．９３ミリリットルに溶解させた該水溶液に、銅微粒子の原料として粒度範囲０．１〜１００μｍの水酸化第二銅（Ｃｕ（ＯＨ）２）２．９２６８ｇ（３０ミリモル）を添加した。その後、窒素ガス雰囲気中で攪拌しながら水素化ホウ素ナトリウム１５ミリモルと、水酸化ナトリウム４８ミリモルを含む水溶液２．０７３ミリリットルを滴下し、その後該還元反応水溶液を４５分間よく攪拌しながら還元反応を行った。
尚、還元反応の終了は反応系からの水素ガスの発生が終了した時点とした。
上記還元反応により、高分子分散剤で少なくとも一部が覆われた銅微粒子が水溶液中に分散している微粒子分散液が得られた。
（２）評価とその結果
得られた銅微粒子分散液をカーボン蒸着された銅メッシュ上に塗布後、乾燥し、上記透過型電子顕微鏡（ＴＥＭ）で観察を行った。
図１に得られた銅微粒子の透過型電子顕微鏡（ＴＥＭ）による写真を示す。図２には、得られた銅微粒子のヒストグラムを示す。
上記透過型電子顕微鏡（ＴＥＭ）による観察結果、得られた銅微粒子は一次粒子の平均粒径が４．７７ｎｍ、ヒストグラムから得られるモード径は５．０ｎｍで、変動係数が１３．６％であった。
[Example 1]
(1) Preparation and Reduction Reaction of Reduction Reaction Aqueous Solution A particle size range of 0.1 to 100 μm as a raw material for copper fine particles was prepared by dissolving 10 g of polyvinylpyrrolidone (PVP, number average molecular weight of about 3500) in 197.93 ml of distilled water. 2.9268 g (30 mmol) of cupric hydroxide (Cu (OH) 2 ) was added. Then, while stirring in a nitrogen gas atmosphere, 2.073 ml of an aqueous solution containing 15 mmol of sodium borohydride and 48 mmol of sodium hydroxide was added dropwise, and then the reduction reaction was carried out with good stirring for 45 minutes. It was.
The end of the reduction reaction was the time when the generation of hydrogen gas from the reaction system was completed.
By the reduction reaction, a fine particle dispersion in which copper fine particles at least partially covered with a polymer dispersant are dispersed in an aqueous solution was obtained.
(2) Evaluation and Results The obtained copper fine particle dispersion was applied on a copper vapor deposited copper mesh, dried, and observed with the above transmission electron microscope (TEM).
The photograph by the transmission electron microscope (TEM) of the copper fine particle obtained in FIG. 1 is shown. FIG. 2 shows a histogram of the obtained copper fine particles.
As a result of observation by the transmission electron microscope (TEM), the obtained copper fine particles had an average primary particle diameter of 4.77 nm, a mode diameter obtained from a histogram of 5.0 nm, and a coefficient of variation of 13.6%. It was.
［実施例２、３］
（１）還元反応水溶液の調製と還元反応
実施例２、３において、原料として使用する水酸化第二銅の粒度範囲をそれぞれ０．１〜５０μｍ、０．１〜１０μｍとした以外は実施例１と同様にして、還元反応を行った。
また、水素ガスの発生が終了した時点は実施例２、３において、それぞれ滴下終了後３５分、３０分であった。
（２）評価とその結果
得られた銅微粒子分散液をカーボン蒸着された銅メッシュ上に塗布後、乾燥し、上記透過型電子顕微鏡（ＴＥＭ）で観察を行った。
実施例２、３で得られた銅微粒子のヒストグラムを図３、４にそれぞれ示す。
上記透過型電子顕微鏡（ＴＥＭ）による観察結果、得られた銅微粒子は一次粒子の平均粒径、モード径、及び変動係数を表２に示す。
[Examples 2 and 3]
(1) Preparation of reduction reaction aqueous solution and reduction reaction In Examples 2 and 3, Example 1 except that the particle size ranges of cupric hydroxide used as a raw material were 0.1 to 50 μm and 0.1 to 10 μm, respectively. In the same manner as described above, a reduction reaction was performed.
In addition, in Examples 2 and 3, the time when generation of hydrogen gas was completed was 35 minutes and 30 minutes after the completion of the dropping, respectively.
(2) Evaluation and Results The obtained copper fine particle dispersion was applied on a copper vapor deposited copper mesh, dried, and observed with the above transmission electron microscope (TEM).
The histograms of the copper fine particles obtained in Examples 2 and 3 are shown in FIGS.
As a result of observation by the transmission electron microscope (TEM), the obtained copper fine particles show the average particle diameter, mode diameter, and coefficient of variation of the primary particles in Table 2.
［比較例１］
（１）還元反応水溶液の調製と還元反応
原料として水酸化第二銅の代わりに酢酸銅を用い、還元反応水溶液への仕込み量と還元温度を表１に示した以外は実施例１に記載したと同様の方法で還元反応を行った。
尚、添加した酢酸銅は全量溶解して、均一の水溶液を形成した。
（２）評価とその結果
実施例１に記載したと同様の評価を行った。図５に得られた銅微粒子の透過型電子顕微鏡（ＴＥＭ）による写真を示す。図６には、得られた銅微粒子のヒストグラムを示す。
実施例１〜３、及び比較例１の製造条件を表１に、評価結果を表２にまとめて示す。
[Comparative Example 1]
(1) Preparation and reduction reaction of reduction reaction aqueous solution It described in Example 1 except having used the copper acetate instead of cupric hydroxide as a raw material, and having shown the preparation amount and reduction temperature to reduction reaction aqueous solution in Table 1. A reduction reaction was carried out in the same manner as above.
The added copper acetate was completely dissolved to form a uniform aqueous solution.
(2) Evaluation and Results The same evaluation as described in Example 1 was performed. The photograph by the transmission electron microscope (TEM) of the copper fine particle obtained in FIG. 5 is shown. FIG. 6 shows a histogram of the obtained copper fine particles.
The production conditions of Examples 1 to 3 and Comparative Example 1 are summarized in Table 1, and the evaluation results are summarized in Table 2.
Claims (8)
還元反応中に該水溶液中には水酸化第二銅が溶解して生成する銅イオンと未溶解の水酸化第二銅が共存していて、還元反応の進行により該水溶液中の銅イオンが還元されて銅原子と銅微粒子が生成するのに伴い、前記未溶解の水酸化第二銅が該水溶液中に連続的に溶解して銅イオンを生成して、還元反応が該水溶液中で水酸化第二銅の飽和溶解度ないしそれ以下の濃度で行なわれることを特徴とする、銅微粒子の製造方法。 Copper fine particles that cause a reduction reaction of cupric hydroxide (Cu (OH) 2 ) in an aqueous reduction reaction solution while stirring in the presence of an organic dispersant (D) and a reducing agent, sodium borohydride (NaBH 4 ). A manufacturing method of
During the reduction reaction, cupric hydroxide dissolved in the aqueous solution coexists with undissolved cupric hydroxide, and the copper ion in the aqueous solution is reduced by the progress of the reduction reaction. As the copper atoms and copper fine particles are formed, the undissolved cupric hydroxide is continuously dissolved in the aqueous solution to produce copper ions, and the reduction reaction is hydroxylated in the aqueous solution. A method for producing copper fine particles, which is performed at a saturation solubility or lower than that of cupric copper.
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| CN115770572A (en) * | 2022-11-23 | 2023-03-10 | 浙江工业大学 | Biochar coupled copper catalyst and preparation method and application thereof |
| US11643568B2 (en) | 2017-03-09 | 2023-05-09 | Research & Business Foundation Sungkyunkwan University | Copper nanoparticle and preparation method therefor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003213311A (en) * | 2002-01-22 | 2003-07-30 | Sumitomo Osaka Cement Co Ltd | Method for manufacturing metal nanoparticle |
| JP2008057041A (en) * | 2006-08-29 | 2008-03-13 | Samsung Electro Mech Co Ltd | Method for producing copper nanoparticle in cubic form |
| JP2009228017A (en) * | 2008-03-19 | 2009-10-08 | Toray Ind Inc | Method for producing copper particulate, and copper particulate |
| JP2009256779A (en) * | 2008-03-27 | 2009-11-05 | Furukawa Electric Co Ltd:The | Method for producing copper fine particle-dispersed aqueous solution, and method for storing the copper fine particle-dispersed aqueous solution |
| JP2010059453A (en) * | 2008-09-02 | 2010-03-18 | Tohoku Univ | Fine copper powder, dispersion liquid thereof, and method for producing fine copper powder |
-
2009
- 2009-10-01 JP JP2009229482A patent/JP5392910B2/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003213311A (en) * | 2002-01-22 | 2003-07-30 | Sumitomo Osaka Cement Co Ltd | Method for manufacturing metal nanoparticle |
| JP2008057041A (en) * | 2006-08-29 | 2008-03-13 | Samsung Electro Mech Co Ltd | Method for producing copper nanoparticle in cubic form |
| JP2009228017A (en) * | 2008-03-19 | 2009-10-08 | Toray Ind Inc | Method for producing copper particulate, and copper particulate |
| JP2009256779A (en) * | 2008-03-27 | 2009-11-05 | Furukawa Electric Co Ltd:The | Method for producing copper fine particle-dispersed aqueous solution, and method for storing the copper fine particle-dispersed aqueous solution |
| JP2010059453A (en) * | 2008-09-02 | 2010-03-18 | Tohoku Univ | Fine copper powder, dispersion liquid thereof, and method for producing fine copper powder |
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| CN102837004A (en) * | 2012-09-25 | 2012-12-26 | 吉林大学 | Preparation method of polyhedral copper nanoparticle |
| JP2014221927A (en) * | 2013-05-13 | 2014-11-27 | 国立大学法人東北大学 | Copper fine particle and method for producing the same |
| DE102017129945A1 (en) | 2016-01-04 | 2018-06-14 | Furukawa Electric Co., Ltd. | Dispersion solution of metal particles |
| JP2017171968A (en) * | 2016-03-22 | 2017-09-28 | 株式会社豊田中央研究所 | Hydrophilic polymer-coated copper nanoparticle, method for producing the same, and sterilization material |
| JP2018145501A (en) * | 2017-03-08 | 2018-09-20 | 株式会社Adeka | Manufacturing method of copper powder, resin composition, method for forming cured article and cured article |
| WO2018164479A1 (en) * | 2017-03-09 | 2018-09-13 | 성균관대학교산학협력단 | Copper nanoparticle and preparation method therefor |
| KR101935273B1 (en) | 2017-03-09 | 2019-01-04 | 성균관대학교 산학협력단 | Copper nanoparticle and preparation method thereof |
| US11643568B2 (en) | 2017-03-09 | 2023-05-09 | Research & Business Foundation Sungkyunkwan University | Copper nanoparticle and preparation method therefor |
| KR20200060225A (en) * | 2018-11-21 | 2020-05-29 | 성균관대학교산학협력단 | Copper nanoparticle manufacturing method using solution process |
| KR102240015B1 (en) | 2018-11-21 | 2021-04-14 | 성균관대학교 산학협력단 | Copper nanoparticle manufacturing method using solution process |
| CN111644174A (en) * | 2020-04-20 | 2020-09-11 | 北京邮电大学 | Method for efficiently preparing high-load transition metal oxide nanoclusters |
| CN115432733A (en) * | 2022-10-18 | 2022-12-06 | 攀枝花学院 | Method for preparing metatitanic acid with narrow particle size distribution |
| CN115770572A (en) * | 2022-11-23 | 2023-03-10 | 浙江工业大学 | Biochar coupled copper catalyst and preparation method and application thereof |
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