JP6274444B2 - Method for producing copper powder - Google Patents
Method for producing copper powder Download PDFInfo
- Publication number
- JP6274444B2 JP6274444B2 JP2014554462A JP2014554462A JP6274444B2 JP 6274444 B2 JP6274444 B2 JP 6274444B2 JP 2014554462 A JP2014554462 A JP 2014554462A JP 2014554462 A JP2014554462 A JP 2014554462A JP 6274444 B2 JP6274444 B2 JP 6274444B2
- Authority
- JP
- Japan
- Prior art keywords
- copper
- suspension
- particles
- cuprous oxide
- copper powder
- 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.)
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Links
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title claims description 231
- 238000004519 manufacturing process Methods 0.000 title claims description 36
- 239000002245 particle Substances 0.000 claims description 152
- 239000000725 suspension Substances 0.000 claims description 147
- 229910052802 copper Inorganic materials 0.000 claims description 130
- 239000010949 copper Substances 0.000 claims description 130
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 claims description 99
- BERDEBHAJNAUOM-UHFFFAOYSA-N copper(I) oxide Inorganic materials [Cu]O[Cu] BERDEBHAJNAUOM-UHFFFAOYSA-N 0.000 claims description 79
- KRFJLUBVMFXRPN-UHFFFAOYSA-N cuprous oxide Chemical compound [O-2].[Cu+].[Cu+] KRFJLUBVMFXRPN-UHFFFAOYSA-N 0.000 claims description 79
- 229940112669 cuprous oxide Drugs 0.000 claims description 79
- 239000003638 chemical reducing agent Substances 0.000 claims description 72
- 239000010419 fine particle Substances 0.000 claims description 55
- 235000010323 ascorbic acid Nutrition 0.000 claims description 50
- 239000011668 ascorbic acid Substances 0.000 claims description 49
- 229960005070 ascorbic acid Drugs 0.000 claims description 49
- 238000006243 chemical reaction Methods 0.000 claims description 48
- OAKJQQAXSVQMHS-UHFFFAOYSA-N hydrazine Substances NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 claims description 43
- 239000007788 liquid Substances 0.000 claims description 41
- 239000007864 aqueous solution Substances 0.000 claims description 37
- 239000011882 ultra-fine particle Substances 0.000 claims description 26
- 150000001879 copper Chemical class 0.000 claims description 24
- -1 hydrazine compound Chemical class 0.000 claims description 23
- 239000000203 mixture Substances 0.000 claims description 22
- 229910001854 alkali hydroxide Inorganic materials 0.000 claims description 20
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims description 20
- 238000009826 distribution Methods 0.000 claims description 20
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 claims description 14
- 229910001431 copper ion Inorganic materials 0.000 claims description 14
- 239000012266 salt solution Substances 0.000 claims description 12
- 230000009467 reduction Effects 0.000 claims description 10
- 238000004140 cleaning Methods 0.000 claims description 9
- 150000002429 hydrazines Chemical class 0.000 claims description 9
- 150000001720 carbohydrates Chemical class 0.000 claims description 8
- 238000002296 dynamic light scattering Methods 0.000 claims description 8
- 150000007524 organic acids Chemical class 0.000 claims description 5
- 238000005259 measurement Methods 0.000 claims description 3
- 239000000654 additive Substances 0.000 claims 1
- 230000000996 additive effect Effects 0.000 claims 1
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 138
- 238000003756 stirring Methods 0.000 description 42
- 238000006722 reduction reaction Methods 0.000 description 40
- 238000000034 method Methods 0.000 description 36
- 239000000243 solution Substances 0.000 description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 28
- DHMQDGOQFOQNFH-UHFFFAOYSA-N Glycine Chemical compound NCC(O)=O DHMQDGOQFOQNFH-UHFFFAOYSA-N 0.000 description 24
- 229910000365 copper sulfate Inorganic materials 0.000 description 20
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 20
- 239000012279 sodium borohydride Substances 0.000 description 20
- 229910000033 sodium borohydride Inorganic materials 0.000 description 20
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 15
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 15
- 230000008569 process Effects 0.000 description 15
- 239000004471 Glycine Substances 0.000 description 12
- 238000005119 centrifugation Methods 0.000 description 12
- 239000011362 coarse particle Substances 0.000 description 12
- 239000008139 complexing agent Substances 0.000 description 11
- 239000002270 dispersing agent Substances 0.000 description 11
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 10
- 238000010908 decantation Methods 0.000 description 10
- 239000000843 powder Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 9
- 239000002184 metal Substances 0.000 description 9
- 239000011230 binding agent Substances 0.000 description 8
- UORVGPXVDQYIDP-UHFFFAOYSA-N borane Chemical class B UORVGPXVDQYIDP-UHFFFAOYSA-N 0.000 description 7
- 229960004643 cupric oxide Drugs 0.000 description 7
- 229920005989 resin Polymers 0.000 description 7
- 239000011347 resin Substances 0.000 description 7
- RGHNJXZEOKUKBD-SQOUGZDYSA-N D-gluconic acid Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(O)=O RGHNJXZEOKUKBD-SQOUGZDYSA-N 0.000 description 6
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 6
- 239000006185 dispersion Substances 0.000 description 5
- 238000011049 filling Methods 0.000 description 5
- 229910000510 noble metal Inorganic materials 0.000 description 5
- 239000002904 solvent Substances 0.000 description 5
- 238000005406 washing Methods 0.000 description 5
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 239000005751 Copper oxide Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 229910000431 copper oxide Inorganic materials 0.000 description 4
- 229910021645 metal ion Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- JJLJMEJHUUYSSY-UHFFFAOYSA-L Copper hydroxide Chemical compound [OH-].[OH-].[Cu+2] JJLJMEJHUUYSSY-UHFFFAOYSA-L 0.000 description 3
- 239000005750 Copper hydroxide Substances 0.000 description 3
- RGHNJXZEOKUKBD-UHFFFAOYSA-N D-gluconic acid Natural products OCC(O)C(O)C(O)C(O)C(O)=O RGHNJXZEOKUKBD-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- 150000001413 amino acids Chemical class 0.000 description 3
- 229910000085 borane Inorganic materials 0.000 description 3
- 239000006227 byproduct Substances 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 229910001956 copper hydroxide Inorganic materials 0.000 description 3
- 235000014113 dietary fatty acids Nutrition 0.000 description 3
- 238000007323 disproportionation reaction Methods 0.000 description 3
- 229930195729 fatty acid Natural products 0.000 description 3
- 239000000194 fatty acid Substances 0.000 description 3
- 238000007429 general method Methods 0.000 description 3
- 239000000174 gluconic acid Substances 0.000 description 3
- 235000012208 gluconic acid Nutrition 0.000 description 3
- 239000008103 glucose Substances 0.000 description 3
- 150000004678 hydrides Chemical class 0.000 description 3
- 239000003999 initiator Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000002667 nucleating agent Substances 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- CIWBSHSKHKDKBQ-DUZGATOHSA-N D-isoascorbic acid Chemical compound OC[C@@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-DUZGATOHSA-N 0.000 description 2
- ROSDSFDQCJNGOL-UHFFFAOYSA-N Dimethylamine Chemical compound CNC ROSDSFDQCJNGOL-UHFFFAOYSA-N 0.000 description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000004931 aggregating effect Effects 0.000 description 2
- 229910052783 alkali metal Inorganic materials 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 239000004020 conductor Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- DMBHHRLKUKUOEG-UHFFFAOYSA-N diphenylamine Chemical compound C=1C=CC=CC=1NC1=CC=CC=C1 DMBHHRLKUKUOEG-UHFFFAOYSA-N 0.000 description 2
- 239000002612 dispersion medium Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 239000000839 emulsion Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 150000004665 fatty acids Chemical class 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000011859 microparticle Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000003002 pH adjusting agent Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000000634 powder X-ray diffraction Methods 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000006228 supernatant Substances 0.000 description 2
- 239000011975 tartaric acid Substances 0.000 description 2
- 235000002906 tartaric acid Nutrition 0.000 description 2
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- BJEPYKJPYRNKOW-REOHCLBHSA-N (S)-malic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O BJEPYKJPYRNKOW-REOHCLBHSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- FJWJYHHBUMICTP-UHFFFAOYSA-N 4,4-dimethylpyrazolidin-3-one Chemical compound CC1(C)CNNC1=O FJWJYHHBUMICTP-UHFFFAOYSA-N 0.000 description 1
- FUSNOPLQVRUIIM-UHFFFAOYSA-N 4-amino-2-(4,4-dimethyl-2-oxoimidazolidin-1-yl)-n-[3-(trifluoromethyl)phenyl]pyrimidine-5-carboxamide Chemical compound O=C1NC(C)(C)CN1C(N=C1N)=NC=C1C(=O)NC1=CC=CC(C(F)(F)F)=C1 FUSNOPLQVRUIIM-UHFFFAOYSA-N 0.000 description 1
- ZZEYCGJAYIHIAZ-UHFFFAOYSA-N 4-methyl-1-phenylpyrazolidin-3-one Chemical compound N1C(=O)C(C)CN1C1=CC=CC=C1 ZZEYCGJAYIHIAZ-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- GUBGYTABKSRVRQ-XLOQQCSPSA-N Alpha-Lactose Chemical compound O[C@@H]1[C@@H](O)[C@@H](O)[C@@H](CO)O[C@H]1O[C@@H]1[C@@H](CO)O[C@H](O)[C@H](O)[C@H]1O GUBGYTABKSRVRQ-XLOQQCSPSA-N 0.000 description 1
- 238000012935 Averaging Methods 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 description 1
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 1
- 229930091371 Fructose Natural products 0.000 description 1
- RFSUNEUAIZKAJO-ARQDHWQXSA-N Fructose Chemical compound OC[C@H]1O[C@](O)(CO)[C@@H](O)[C@@H]1O RFSUNEUAIZKAJO-ARQDHWQXSA-N 0.000 description 1
- 239000005715 Fructose Substances 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
- 150000000994 L-ascorbates Chemical class 0.000 description 1
- 150000000996 L-ascorbic acids Chemical class 0.000 description 1
- GUBGYTABKSRVRQ-QKKXKWKRSA-N Lactose Natural products OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O GUBGYTABKSRVRQ-QKKXKWKRSA-N 0.000 description 1
- 239000012448 Lithium borohydride Substances 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
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- 239000004962 Polyamide-imide Substances 0.000 description 1
- 229920002873 Polyethylenimine Polymers 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000003973 alkyl amines Chemical class 0.000 description 1
- BJEPYKJPYRNKOW-UHFFFAOYSA-N alpha-hydroxysuccinic acid Natural products OC(=O)C(O)CC(O)=O BJEPYKJPYRNKOW-UHFFFAOYSA-N 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 229920003180 amino resin Polymers 0.000 description 1
- BIVUUOPIAYRCAP-UHFFFAOYSA-N aminoazanium;chloride Chemical compound Cl.NN BIVUUOPIAYRCAP-UHFFFAOYSA-N 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- UORVGPXVDQYIDP-BJUDXGSMSA-N borane Chemical class [10BH3] UORVGPXVDQYIDP-BJUDXGSMSA-N 0.000 description 1
- 229910010277 boron hydride Inorganic materials 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- PTYMQUSHTAONGW-UHFFFAOYSA-N carbonic acid;hydrazine Chemical compound NN.OC(O)=O PTYMQUSHTAONGW-UHFFFAOYSA-N 0.000 description 1
- XEVRDFDBXJMZFG-UHFFFAOYSA-N carbonyl dihydrazine Chemical compound NNC(=O)NN XEVRDFDBXJMZFG-UHFFFAOYSA-N 0.000 description 1
- 150000007942 carboxylates Chemical group 0.000 description 1
- 239000003985 ceramic capacitor Substances 0.000 description 1
- 235000015165 citric acid Nutrition 0.000 description 1
- 150000004699 copper complex Chemical class 0.000 description 1
- ORTQZVOHEJQUHG-UHFFFAOYSA-L copper(II) chloride Chemical compound Cl[Cu]Cl ORTQZVOHEJQUHG-UHFFFAOYSA-L 0.000 description 1
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 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
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- CDHICTNQMQYRSM-UHFFFAOYSA-N di(propan-2-yl)alumane Chemical compound CC(C)[AlH]C(C)C CDHICTNQMQYRSM-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 235000010350 erythorbic acid Nutrition 0.000 description 1
- 239000004318 erythorbic acid Substances 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000012493 hydrazine sulfate Substances 0.000 description 1
- 229910000377 hydrazine sulfate Inorganic materials 0.000 description 1
- LIAWOTKNAVAKCX-UHFFFAOYSA-N hydrazine;dihydrochloride Chemical compound Cl.Cl.NN LIAWOTKNAVAKCX-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
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- 239000012948 isocyanate Substances 0.000 description 1
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- HDZGCSFEDULWCS-UHFFFAOYSA-N monomethylhydrazine Chemical compound CNN HDZGCSFEDULWCS-UHFFFAOYSA-N 0.000 description 1
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- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
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- 238000012856 packing Methods 0.000 description 1
- SWELZOZIOHGSPA-UHFFFAOYSA-N palladium silver Chemical compound [Pd].[Ag] SWELZOZIOHGSPA-UHFFFAOYSA-N 0.000 description 1
- CMCWWLVWPDLCRM-UHFFFAOYSA-N phenidone Chemical compound N1C(=O)CCN1C1=CC=CC=C1 CMCWWLVWPDLCRM-UHFFFAOYSA-N 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- HKOOXMFOFWEVGF-UHFFFAOYSA-N phenylhydrazine Chemical compound NNC1=CC=CC=C1 HKOOXMFOFWEVGF-UHFFFAOYSA-N 0.000 description 1
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- 238000007639 printing Methods 0.000 description 1
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- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- BEOOHQFXGBMRKU-UHFFFAOYSA-N sodium cyanoborohydride Chemical compound [Na+].[B-]C#N BEOOHQFXGBMRKU-UHFFFAOYSA-N 0.000 description 1
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical compound [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 description 1
- 235000019982 sodium hexametaphosphate Nutrition 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 125000001273 sulfonato group Chemical group [O-]S(*)(=O)=O 0.000 description 1
- 150000003459 sulfonic acid esters Chemical class 0.000 description 1
- DDPWVABNMBRBFI-UHFFFAOYSA-N tert-butylhydrazine;hydron;chloride Chemical compound Cl.CC(C)(C)NN DDPWVABNMBRBFI-UHFFFAOYSA-N 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 239000001577 tetrasodium phosphonato phosphate Substances 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- 150000004670 unsaturated fatty acids Chemical class 0.000 description 1
- 235000021122 unsaturated fatty acids Nutrition 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D11/00—Inks
- C09D11/52—Electrically conductive inks
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C9/00—Alloys based on copper
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
- H01B1/026—Alloys based on copper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
- B22F1/107—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing organic material comprising solvents, e.g. for slip casting
Description
本発明は、粒度分布の揃った、分散性に優れる、連結粒子や粗大粒子のない銅粉末を高価な貴金属や高分子分散剤を使用することなく製造することができる製造方法に関するものであり、特に、導電性ペーストとして用いる、銅ペースト用の銅粉末の製造方法に関する。 The present invention relates to a production method capable of producing a copper powder having a uniform particle size distribution, excellent dispersibility, and free of connected particles and coarse particles without using an expensive noble metal or polymer dispersant, In particular, it is related with the manufacturing method of the copper powder for copper pastes used as an electrically conductive paste.
従来、回路基板上の導体として、銅、銀、銅合金、金、白金、銀−パラジウムなどの金属粉末を使用したペーストが用いられてきた。 Conventionally, pastes using metal powders such as copper, silver, copper alloys, gold, platinum, silver-palladium have been used as conductors on circuit boards.
なかでも、より安価で資源の豊富な銅の粉末は、主に積層セラミックコンデンサなどの外部電極用の導電性ペーストやスルーホール用ペースト、厚膜導電性ペーストなどの導電性ペーストに使用されている。これらに使用される銅粉末の粒子の大きさは、０．５〜１０μｍ程度であり、球状、フレーク状、不定形状などの様々な形状の銅微粒子が使用されている。これらの銅粉末は主に、電解法やアトマイズ法により製造されている。 Among them, cheaper and more abundant copper powder is mainly used for conductive pastes for external electrodes such as multilayer ceramic capacitors, conductive pastes for through holes, thick film conductive pastes, etc. . The size of the copper powder particles used in these is about 0.5 to 10 μm, and copper fine particles having various shapes such as spherical shape, flake shape, and irregular shape are used. These copper powders are mainly produced by an electrolytic method or an atomizing method.
これらの導電性ペーストを基板に印刷する方法は広く知られており、導電性ペーストを、インクジェットプリンター、スクリーン印刷機、又はオフセット印刷機等を用いて直接基板等に塗布することで、基板等上に簡便に配線等を形成する方法が開発され実用化されている。 A method for printing these conductive pastes on a substrate is widely known, and the conductive paste is directly applied to a substrate or the like by using an inkjet printer, a screen printing machine, an offset printing machine, or the like. A method for easily forming wiring and the like has been developed and put into practical use.
一方で、導電性ペーストを用いて形成する電子回路の微細化や高密度化に伴い、より微細な配線パターンと印刷塗膜の平滑化が要請されている。このため、導電性インク等の原材料である導電性ペースト用の金属微粒子は、より微細で、粒度分布が狭く、分散性に優れ、連結粒子や粗大粒子のないことが望まれている。 On the other hand, with the miniaturization and high density of electronic circuits formed using conductive paste, smoother finer wiring patterns and printed coatings are required. For this reason, the metal fine particles for conductive paste, which is a raw material such as conductive ink, are desired to be finer, have a narrow particle size distribution, excellent dispersibility, and have no connected particles or coarse particles.
このような金属微粒子の製造方法として、以下の方法が提案されている。 The following methods have been proposed as a method for producing such metal fine particles.
特許文献１には、アミノ酸などの錯化剤を含む銅塩水溶液に水酸化アルカリを加え、還元糖を加えて亜酸化銅を水溶液中に析出させ、これにヒドラジンを加えて亜酸化銅を還元して銅粉末を得る方法が記載されている。 In Patent Document 1, alkali hydroxide is added to an aqueous copper salt solution containing a complexing agent such as an amino acid, reducing sugar is added to precipitate cuprous oxide in the aqueous solution, and hydrazine is added thereto to reduce cuprous oxide. Thus, a method for obtaining copper powder is described.
特許文献２には、錯化剤を含む銅塩水溶液に水酸化アルカリを加え加熱熟成して、黒色の酸化第二銅を生成したのち、還元糖を加えて亜酸化銅を水溶液中に析出させ、これにヒドラジンを加えて亜酸化銅を還元して銅粉末を得る方法が記載されている。 In Patent Document 2, alkali hydroxide is added to a copper salt aqueous solution containing a complexing agent and heated and aged to form black cupric oxide, and then reducing sugar is added to precipitate cuprous oxide in the aqueous solution. In addition, a method is described in which hydrazine is added thereto to reduce cuprous oxide to obtain a copper powder.
特許文献３には、錯化剤を含む銅塩水溶液に水酸化アルカリを加え加熱熟成して、黒色の酸化第二銅を生成したのち、還元糖を加えて亜酸化銅を水溶液中に析出させ、これにヒドラジンと水素化ホウ素化合物を混合したものを加えて亜酸化銅を還元して銅超微粒子スラリーを得る方法が記載されている。 In Patent Document 3, alkali hydroxide is added to a copper salt aqueous solution containing a complexing agent and heat-aged to produce black cupric oxide. Then, reducing sugar is added to precipitate cuprous oxide in the aqueous solution. In addition, a method is described in which a mixture of hydrazine and a borohydride compound is added thereto to reduce cuprous oxide to obtain a copper ultrafine particle slurry.
特許文献４には、硫酸銅溶液をＬ−アルコスビン酸又はＬ−アスコルビン酸塩類で還元する方法、特許文献５には、硫酸銅溶液をＤ−エリソルビン酸又はＤ−エリソルビン酸塩類で還元する方法が記載されている。 Patent Document 4 discloses a method of reducing a copper sulfate solution with L-alkosbic acid or L-ascorbates, and Patent Document 5 discloses a method of reducing a copper sulfate solution with D-erythorbic acid or D-erythorbates. Have been described.
非特許文献１には、硫酸銅水溶液を分散剤の共存下アスコルビン酸により還元する銅微粒子の製造方法が記載されている。 Non-Patent Document 1 describes a method for producing copper fine particles in which an aqueous copper sulfate solution is reduced with ascorbic acid in the presence of a dispersant.
特許文献６には、銅イオン、還元剤、錯化剤の混合水溶液に反応開始剤として水素化ホウ素アルカリ等を添加して還元反応させた後に、銅イオン、還元剤、ｐＨ調整剤を添加して銅微粉末を製造する方法が記載されている。 In Patent Document 6, an alkali borohydride or the like is added as a reaction initiator to a mixed aqueous solution of copper ions, a reducing agent, and a complexing agent to cause a reduction reaction, and then copper ions, a reducing agent, and a pH adjusting agent are added. A method for producing copper fine powder is described.
特許文献７には、銅イオンを含む不飽和脂肪酸溶液とグルコース溶液を混合してエマルジョンを形成した後、エマルジョンにアスコルビン酸水溶液を加える銅微粒子の製造方法が記載されている。 Patent Document 7 describes a method for producing copper fine particles in which an unsaturated fatty acid solution containing copper ions and a glucose solution are mixed to form an emulsion, and then an ascorbic acid aqueous solution is added to the emulsion.
特許文献８には、硫酸銅水溶液又は還元剤の少なくとも一方に、反応促進剤としてポリエチレンイミン等の水溶性ポリマーを分散剤とした貴金属超微粒子を添加し、硫酸銅水溶液と還元剤とを混合する銅粉の製造方法が記載されている。 In Patent Document 8, noble metal ultrafine particles containing a water-soluble polymer such as polyethyleneimine as a dispersant as a reaction accelerator are added to at least one of an aqueous copper sulfate solution or a reducing agent, and the aqueous copper sulfate solution and the reducing agent are mixed. A method for producing copper powder is described.
特許文献９には、金属塩水溶液を、第一還元工程で水素化ホウ素塩などの強い還元剤を用いて金属イオンの多くを還元し、第二還元工程において還元力が弱いアルキルアミン又はアルカノールアミン還元剤を用いて金属イオンの全てを還元する、ナノサイズのロッド状金属微粒子の製造方法が記載されている。 In Patent Document 9, an aqueous metal salt solution is used to reduce most of metal ions using a strong reducing agent such as a borohydride salt in the first reduction step, and an alkylamine or alkanolamine having a weak reducing power in the second reduction step. A method for producing nano-sized rod-shaped metal fine particles is described in which all metal ions are reduced using a reducing agent.
しかし、特許文献１や特許文献２に記載の、錯化剤を含む銅塩水溶液に水酸化アルカリを加え、酸化第二銅を生成したのち、還元糖を加えて亜酸化銅を水溶液中に析出させ、これにヒドラジンを加えて亜酸化銅を還元して銅粉末を得る方法では、水酸化アルカリの添加によって水酸化銅の生成とともに懸濁液の粘度が顕著に上昇するため、中和・還元反応が不均一となり、粒子径の揃った亜酸化銅を含む懸濁液を得ることができず、ひいては粒子径の揃った銅粒子を生成することができない。 However, after adding alkali hydroxide to the copper salt aqueous solution containing the complexing agent described in Patent Document 1 and Patent Document 2 to form cupric oxide, reducing sugar is added to precipitate cuprous oxide in the aqueous solution. In this method, hydrazine is added to reduce cuprous oxide to obtain copper powder. The addition of alkali hydroxide significantly increases the viscosity of the suspension as copper hydroxide is formed. The reaction becomes non-uniform, and a suspension containing cuprous oxide with a uniform particle size cannot be obtained, and as a result, copper particles with a uniform particle size cannot be produced.
また、特許文献３の方法で得られる銅微粒子の平均粒径は０．１μｍ以下と微細であるが、洗浄や回収工程が煩雑であり工業的に銅ペーストに適応するのは難しい場合がある。また、ホウ素化水素ナトリウムの反応とヒドラジンの反応が同時に起こりうるため、粒度分布は、核剤や反応促進剤を添加した場合に比較してブロードになることがある。 Moreover, although the average particle diameter of the copper fine particle obtained by the method of patent document 3 is as fine as 0.1 micrometer or less, a washing | cleaning and collection | recovery process are complicated and it may be difficult to adapt industrially to a copper paste. In addition, since the reaction of sodium borohydride and the reaction of hydrazine can occur simultaneously, the particle size distribution may be broader than when a nucleating agent or a reaction accelerator is added.
また特許文献４、５の硫酸銅水溶液に核剤や反応促進剤を添加することなく還元して銅微粒子を製造する方法では、核発生が不均一となり、比較的ブロードな粒度分布となる。また、硫酸銅水溶液のｐＨが５以下であるため成長中の銅微粒子が相互に凝集し連結が発生する場合がある。 In addition, in the method of producing copper fine particles by reducing the copper sulfate aqueous solution of Patent Documents 4 and 5 without adding a nucleating agent or a reaction accelerator, the nucleation is non-uniform and the particle size distribution is relatively broad. In addition, since the pH of the aqueous copper sulfate solution is 5 or less, the growing copper fine particles may agglomerate with each other and be connected.
また非特許文献１の方法で得られる銅微粒子は分散剤によって凝集を防ぐことができるが、平均粒径は、１．５μｍであり、十分に微細とはいえない。 Further, the copper fine particles obtained by the method of Non-Patent Document 1 can be prevented from agglomerating with a dispersant, but the average particle diameter is 1.5 μm and cannot be said to be sufficiently fine.
また特許文献６の銅イオン、還元剤および錯化剤からなる混合水溶液に反応開始剤として水素化ホウ素アルカリを添加して還元反応させた後に、銅イオン、還元剤、ｐＨ調整剤を添加して銅微粉末を製造する方法は、得られる銅微粒子の平均粒径は０．１６〜０．６１μｍで微細であり、開始剤の効果により粒度分布が改善されるが、銅イオン溶液に水素化ホウ素アルカリを直接添加した場合、反応は急激で不均一になりやすく、連結粒子が生成されやすいことがある。 Further, after adding alkali borohydride as a reaction initiator to the mixed aqueous solution composed of copper ion, reducing agent and complexing agent of Patent Document 6 to cause reduction reaction, copper ion, reducing agent and pH adjuster are added. In the method for producing copper fine powder, the average particle size of the obtained copper fine particles is 0.16 to 0.61 μm, and the particle size distribution is improved by the effect of the initiator, but the copper ion solution contains borohydride. When alkali is directly added, the reaction tends to be rapid and non-uniform, and linked particles may be easily generated.
また特許文献７、８の方法で得られる銅微粒子は分散剤によって凝集を防ぐことができるが、分散剤が銅粒子の回収後も銅表面から容易に脱離しないため、過剰に表面が有機物におおわれた銅粒子となり、導電性ペーストとして用いる場合には焼成温度を高くして有機物を除く必要があるという欠点がある。さらに、特許文献８の方法では、高価な貴金属を含む反応促進剤（核剤）を別に調整する必要があり工業的に好ましくない。 Moreover, although the copper fine particles obtained by the methods of Patent Documents 7 and 8 can be prevented from aggregating with a dispersant, the dispersant does not easily desorb from the copper surface even after recovery of the copper particles, so that the surface becomes excessively organic. When it becomes covered copper particles and used as a conductive paste, there is a disadvantage that it is necessary to remove the organic matter by raising the firing temperature. Furthermore, in the method of Patent Document 8, it is necessary to separately adjust a reaction accelerator (nucleating agent) containing an expensive noble metal, which is not industrially preferable.
また特許文献９では、第一還元工程で、還元力の強い還元剤を用いて金属イオンの多くを還元し、第二還元工程において還元力が弱い還元剤を用いて金属イオンの全てを還元することで、ロッド状の金属微粒子を得ているが、対称性に優れ、粒度分布の揃った銅粒子を生成するものではない。 In Patent Document 9, in the first reduction step, most of the metal ions are reduced using a reducing agent having a strong reducing power, and in the second reduction step, all of the metal ions are reduced using a reducing agent having a weak reducing power. Thus, rod-shaped metal fine particles are obtained, but copper particles having excellent symmetry and uniform particle size distribution are not generated.
したがって、本発明は、このような従来の問題点に鑑み、粒度分布の揃った、分散性に優れる、連結粒子や粗大粒子のない銅粉末を高価な貴金属や高分子分散剤を使用することなく製造することができる製造方法に関するものであり、特に、導電性ペーストとして用いる、銅ペースト用の銅粉末の製造方法に関するものである。 Therefore, in view of such a conventional problem, the present invention provides a copper powder having a uniform particle size distribution, excellent dispersibility, and free of connected particles and coarse particles without using an expensive noble metal or polymer dispersant. The present invention relates to a manufacturing method that can be manufactured, and particularly relates to a manufacturing method of copper powder for copper paste used as a conductive paste.
本発明者らは、上記の課題を解決するために鋭意検討を進めた結果、本発明を完成するに至った。すなわち、本発明は下記のとおりのものである。 As a result of diligent studies to solve the above problems, the present inventors have completed the present invention. That is, the present invention is as follows.
本発明は、二価の銅イオンを有する銅塩水溶液と第一還元剤である還元性の糖類との混合物に水酸化アルカリを添加して亜酸化銅粒子を含む懸濁液を得る第１工程、前記亜酸化銅粒子を含む懸濁液にヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加して銅微粒子を生成させる第２工程を含むことを特徴とする銅粉末の製造方法である（本発明１）。 The present invention provides a first step of obtaining a suspension containing cuprous oxide particles by adding an alkali hydroxide to a mixture of an aqueous copper salt solution having divalent copper ions and a reducing saccharide as a first reducing agent. A method for producing a copper powder, comprising a second step of adding one or more reducing agents selected from a hydrazine compound or ascorbic acid to the suspension containing the cuprous oxide particles to produce copper fine particles. (Invention 1).
また、本発明は、前記第一還元剤である還元性の糖類の添加量が反応等量の１．００〜１．２０倍である本発明１に記載の銅粉末の製造方法である（本発明２）。 Moreover, this invention is a manufacturing method of the copper powder of this invention 1 whose addition amount of the reducing saccharide which is said 1st reducing agent is 1.00-1.20 time of reaction equivalent (this book). Invention 2).
また、本発明は、前記第１工程において水酸化アルカリを添加した後、前記第２工程において還元剤を添加するまでの時間が６０分以内である本発明１又は２に記載の銅粉末の製造方法である（本発明３）。 Moreover, this invention is manufacturing copper powder of this invention 1 or 2 whose time after adding an alkali hydroxide in said 1st process until it adds a reducing agent in said 2nd process is less than 60 minutes. This is a method (Invention 3).
また、本発明は、前記第２工程において、還元剤を添加する懸濁液のｐＨが７．０〜９．５である本発明１〜３のいずれか一項に記載の銅粉末の製造方法である（本発明４）。 Moreover, this invention is a manufacturing method of the copper powder as described in any one of this invention 1-3 whose pH of the suspension liquid which adds a reducing agent is 7.0-9.5 in the said 2nd process. (Invention 4).
また、本発明は、前記亜酸化銅粒子を含む懸濁液に第二還元剤を添加して亜酸化銅粒子と銅超微粒子を含む懸濁液を得る第２−１工程、前記亜酸化銅粒子と銅超微粒子を含む懸濁液にヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加して銅微粒子を生成させる第２−２工程を含む本発明１〜４のいずれか一項に記載の銅粉末の製造方法である（本発明５）。 Moreover, this invention adds the 2nd reducing agent to the suspension containing the said cuprous oxide particle, the 2nd-1 step which obtains the suspension containing a cuprous oxide particle and a copper ultrafine particle, the said cuprous oxide Any one of the present inventions 1 to 4 including a second step 2-2 in which one or more reducing agents selected from a hydrazine compound or ascorbic acid are added to a suspension containing particles and copper ultrafine particles to form copper fine particles. It is a manufacturing method of the copper powder as described in (Item 5).
また、本発明は、前記第二還元剤の添加量が反応等量の１０−３倍から１０−５倍である本発明５に記載の銅粉末の製造方法である（本発明６）。Moreover, this invention is a manufacturing method of the copper powder of this invention 5 whose addition amount of said 2nd reducing agent is 10 <-3> times 10 <-5> times the reaction equivalent (this invention 6).
また、本発明は、前記第１工程において水酸化アルカリを添加した後、前記第２−２工程においてヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加するまでの時間が６０分以内である本発明５又は６に記載の銅粉末の製造方法である（本発明７）。 Further, in the present invention, after adding alkali hydroxide in the first step, the time until adding one or more reducing agents selected from hydrazine compounds or ascorbic acid in the step 2-2 is within 60 minutes. It is the manufacturing method of the copper powder of this invention 5 or 6 which is (this invention 7).
また、本発明は、前記第２−１工程において、懸濁液のｐＨが７．０〜９．５である本発明５〜７のいずれか一項に記載の銅粉末の製造方法である（本発明８）。 Moreover, this invention is a manufacturing method of the copper powder as described in any one of this invention 5-7 whose pH of suspension is 7.0-9.5 in the said 2nd-1 process ( Invention 8).
また、本発明は、懸濁液に含まれる銅微粒子を洗浄する第３工程を含み、洗浄液が有機酸水溶液である本発明１〜８のいずれか一項に記載の銅粉末の製造方法である（本発明９）。 Moreover, this invention is a manufacturing method of the copper powder as described in any one of this invention 1-8 which includes the 3rd process of wash | cleaning the copper microparticles contained in suspension, and a washing | cleaning liquid is organic acid aqueous solution. (Invention 9).
また、本発明は、本発明１〜９のいずれか一項に記載する銅粉末の製造方法により得られた銅粉末であって、ＳＥＭによって観測される銅粒子の平均粒径が０．１〜１．３μｍであって、ＳＥＭによって観測される銅粒子の平均粒径に対する、動的光散乱粒度分布測定装置によって観測される凝集粒子の平均粒径の比が５．０以下である銅粉末である（本発明１０）。 Moreover, this invention is the copper powder obtained by the manufacturing method of the copper powder as described in any one of this invention 1-9, Comprising: The average particle diameter of the copper particle observed by SEM is 0.1. A copper powder having a ratio of the average particle diameter of aggregated particles observed by a dynamic light scattering particle size distribution measuring apparatus to 5.0 μm or less, which is 1.3 μm and the average particle diameter of copper particles observed by SEM There is (Invention 10).
また、本発明は、本発明１０に記載の銅粉末を含む銅ペーストである（本発明１１）。 Moreover, this invention is a copper paste containing the copper powder of this invention 10 (this invention 11).
本発明によれば、粒度分布の揃った、分散性に優れる、連結粒子や粗大粒子のない銅粉末を高価な貴金属や高分子分散剤等を使用することなく安定に製造することができる。 According to the present invention, it is possible to stably produce a copper powder having a uniform particle size distribution and excellent dispersibility and free of connected particles and coarse particles without using an expensive noble metal or a polymer dispersant.
また、本発明によって得られた銅粉末は、粒度分布の揃った、分散性に優れる、連結粒子や粗大粒子のない銅粉末であるために、導電性ペーストに好適に用いられる。 Moreover, since the copper powder obtained by this invention is a copper powder with uniform particle size distribution, excellent dispersibility, and without a connection particle | grain and a coarse particle, it is used suitably for an electrically conductive paste.
まず、本発明に係る銅粉末の製造方法について述べる。 First, a method for producing a copper powder according to the present invention will be described.
本発明に係る銅粉末の製造方法は、図１に示すように二価の銅イオンを有する銅塩水溶液と第一還元剤である還元性の糖類との混合物に水酸化アルカリを混合して亜酸化銅粒子を含む懸濁液を得る第１工程、前記亜酸化銅粒子を含む懸濁液に還元剤を添加して銅微粒子を生成させる第２工程を含んでいる。 As shown in FIG. 1, the method for producing a copper powder according to the present invention comprises mixing an alkali hydroxide with a mixture of a copper salt aqueous solution having divalent copper ions and a reducing saccharide as a first reducing agent. A first step of obtaining a suspension containing copper oxide particles, and a second step of generating a copper fine particle by adding a reducing agent to the suspension containing the cuprous oxide particles.
また、本発明は第２工程で得られた懸濁液に含まれる銅微粒子を洗浄する第３工程を含んでいてもよい。 Moreover, this invention may include the 3rd process of wash | cleaning the copper microparticles contained in the suspension liquid obtained at the 2nd process.
本発明の第１工程においては、二価の銅イオンを有する銅塩水溶液と第一還元剤とを予め混合しておくことが必須である。この混合液に水酸化アルカリを攪拌しながら添加すると、二価の銅イオンの水酸化物の中和と脱水及び第一還元剤による銅の２価イオンの還元がほぼ同時に進行することで、後工程での反応性に優れる粒子径の揃った亜酸化銅粒子を含む懸濁液が生成される。当該懸濁液を用いることで、以後の還元が速やかに進行して、粒子径の揃った銅粒子を生成することができる。銅塩水溶液に水酸化アルカリを加えた後に第一還元剤を添加した場合には、水酸化アルカリの添加によって水酸化銅の生成とともに懸濁液の粘度が顕著に上昇するため、中和・還元反応が不均一となり、粒子径の揃った亜酸化銅を含む懸濁液を得ることができず、ひいては粒子径の揃った銅粒子を生成することができない。 In the 1st process of this invention, it is essential to mix the copper salt aqueous solution which has a bivalent copper ion, and a 1st reducing agent previously. When alkali hydroxide is added to this mixed liquid while stirring, neutralization and dehydration of divalent copper ion hydroxide and reduction of copper divalent ion by the first reducing agent proceed almost simultaneously. A suspension containing cuprous oxide particles having a uniform particle diameter and excellent reactivity in the process is produced. By using the suspension, subsequent reduction can proceed rapidly, and copper particles having a uniform particle diameter can be generated. If the first reducing agent is added after adding alkali hydroxide to the copper salt aqueous solution, the viscosity of the suspension increases significantly with the formation of copper hydroxide due to the addition of alkali hydroxide. The reaction becomes non-uniform, and a suspension containing cuprous oxide with a uniform particle size cannot be obtained, and as a result, copper particles with a uniform particle size cannot be produced.
本発明で用いる二価の銅イオンを有する銅塩としては硫酸銅、塩化銅、硝酸銅、酢酸銅等を用いることができるが、工業的に硫酸銅が好ましい。 As a copper salt having a divalent copper ion used in the present invention, copper sulfate, copper chloride, copper nitrate, copper acetate and the like can be used, but copper sulfate is industrially preferable.
本発明で用いる第一還元剤は還元性の糖類である。還元性の糖類としてはグルコース、フルクトース、ラクトース等を用いることができるが、工業的にグルコースが好ましい。 The first reducing agent used in the present invention is a reducing saccharide. Glucose, fructose, lactose, etc. can be used as the reducing saccharide, but glucose is preferred industrially.
第一還元剤の添加量は、反応等量の１．１０〜１．２０倍であることが好ましい。第一還元剤の添加量が反応等量の１．１０倍未満ではその後の還元反応において、１価の銅の錯イオンとともに２価の銅イオンや水酸化銅、酸化銅が多く混在するため、再現性のある銅超微粒子の生成が妨げられる。第一還元剤の添加量が反応等量の１．２０倍を超えた場合には、不均化反応が生じて、最終的に得られる銅微粒子に粗大粒子が混入する恐れがある。 The amount of the first reducing agent added is preferably 1.10 to 1.20 times the reaction equivalent. If the addition amount of the first reducing agent is less than 1.10 times the reaction equivalent, in the subsequent reduction reaction, there are many divalent copper ions, copper hydroxide, and copper oxide together with the monovalent copper complex ions. The production of reproducible copper ultrafine particles is hindered. When the addition amount of the first reducing agent exceeds 1.20 times the reaction equivalent, disproportionation reaction may occur and coarse particles may be mixed into the finally obtained copper fine particles.
本発明で用いる水酸化アルカリとしては、水酸化ナトリウム、水酸化カリウム、アンモニア等を用いることができるが工業的に水酸化ナトリウムが好ましい。 As the alkali hydroxide used in the present invention, sodium hydroxide, potassium hydroxide, ammonia or the like can be used, but sodium hydroxide is industrially preferable.
第１工程における反応液の温度は７０℃以上であることが好ましく、より好ましくは８０℃以上である。反応液の温度が７０℃未満では亜酸化銅への還元反応が速やかに進まないため好ましくない。 The temperature of the reaction solution in the first step is preferably 70 ° C. or higher, more preferably 80 ° C. or higher. If the temperature of the reaction solution is less than 70 ° C., the reduction reaction to cuprous oxide does not proceed rapidly, such being undesirable.
本発明においては、第２工程で懸濁液中に錯化剤が存在することが好ましい。錯化剤は第１工程において銅塩水溶液に予め添加しても、水酸化アルカリ添加後に添加してもよいし、亜酸化銅粒子が生成した懸濁液に添加してもよい。第２工程で懸濁液中に錯化剤が存在することにより、懸濁液に含まれる亜酸化銅の一部が１価の銅錯体となり、第２工程での銅粒子生成の核となる銅超微粒子の生成を助ける。 In the present invention, it is preferable that a complexing agent is present in the suspension in the second step. The complexing agent may be added in advance to the copper salt aqueous solution in the first step, or may be added after the alkali hydroxide is added, or may be added to the suspension in which the cuprous oxide particles are formed. Due to the presence of the complexing agent in the suspension in the second step, a part of the cuprous oxide contained in the suspension becomes a monovalent copper complex, which becomes the nucleus of copper particle generation in the second step. Helps produce ultrafine copper particles.
錯化剤としてはアミノ酸及びその塩、アンモニア及びアンモニウム塩、有機アミン類酒石酸、グルコン酸等のオキシカルボン酸又はそのアルカリ金属塩等から選ばれた少なくとも１種以上の化合物を用いることができるが、作業性からアミノ酸が好ましく、特にグリシンが好ましい。 As the complexing agent, at least one compound selected from amino acids and salts thereof, ammonia and ammonium salts, organic amines tartaric acid, oxycarboxylic acids such as gluconic acid or alkali metal salts thereof, and the like can be used. An amino acid is preferable from the viewpoint of workability, and glycine is particularly preferable.
本発明の第１工程において得られる懸濁液に含まれる亜酸化銅粒子は、粒子径が揃った分散性に優れる微粒子である。亜酸化銅粒子が不均一であったり、凝集していたり、沈降しやすかったりすると、均一な亜酸化銅懸濁液を得ることができず、ひいては粒子径の揃った銅粒子を生成することができない。 The cuprous oxide particles contained in the suspension obtained in the first step of the present invention are fine particles having a uniform particle size and excellent dispersibility. If the cuprous oxide particles are non-uniform, agglomerated, or easily settled, a uniform cuprous oxide suspension cannot be obtained, and as a result, copper particles having a uniform particle diameter may be generated. Can not.
本発明の第１工程において得られる懸濁液には亜酸化銅の粒子とともに、反応副生成物が含まれる。本発明においては、懸濁液に高濃度で含まれることになる反応副生成物が増粘・緩衝作用を示すことにより以後の反応を安定化させるため、反応副生成物を含む懸濁液をそのまま第２工程で用いる。反応副生成物は反応に用いる銅塩や糖によって変化するが、例えばグルコン酸や硫酸ナトリウムなどである。 The suspension obtained in the first step of the present invention contains reaction by-products together with cuprous oxide particles. In the present invention, the reaction by-product that is contained in the suspension at a high concentration stabilizes the subsequent reaction by exhibiting a thickening / buffering action. Used as it is in the second step. The reaction by-product varies depending on the copper salt and sugar used in the reaction, and examples thereof include gluconic acid and sodium sulfate.
本発明の第２工程においては、亜酸化銅粒子を含む懸濁液に還元剤を添加して銅微粒子を生成させる。 In the second step of the present invention, a reducing agent is added to a suspension containing cuprous oxide particles to produce copper fine particles.
本発明の第２工程で用いる還元剤としては、ヒドラジン化合物やアスコルビン酸等を用いることができる。ヒドラジン化合物とは、ヒドラジン、ヒドラジンの水和物、ヒドラジンの塩、ヒドラジンの置換基誘導体、ヒドラジンの置換基誘導体の塩を含む総称である。ヒドラジン化合物に属する化合物としては、ヒドラジン水和物、一塩酸ヒドラジン、二塩酸ヒドラジン、硫酸ヒドラジン、臭酸ヒドラジン、炭酸ヒドラジン、メチルヒドラジン、フェニルヒドラジン、ｔｅｒｔ−ブチルヒドラジン塩酸塩、カルボヒドラジド、１−フェニル−４，４−ジメチル−３−ピラゾリドン、１−フェニル−４−メチル−３−ピラゾリドン、１−フェニル−３−ピラゾリドンなどが挙げられる。アスコルビン酸とは、アスコルビン酸、及び、その立体異性体であるエリソルビン酸やそのアルカリ金属塩（ナトリウム、カリウム塩）などを包含する。還元剤の添加量は、亜酸化銅を完全に反応させるために、反応等量の１．１倍以上添加することが好ましい。添加量の上限は特に制限されないが、経済的観点から反応等量の４倍以下であることが好ましい。 As the reducing agent used in the second step of the present invention, a hydrazine compound, ascorbic acid, or the like can be used. The hydrazine compound is a generic name including hydrazine, hydrazine hydrate, hydrazine salt, hydrazine substituent derivative, and hydrazine substituent derivative salt. The compounds belonging to the hydrazine compounds include hydrazine hydrate, hydrazine monohydrochloride, hydrazine dihydrochloride, hydrazine sulfate, hydrazine odorate, hydrazine carbonate, methyl hydrazine, phenyl hydrazine, tert-butyl hydrazine hydrochloride, carbohydrazide, 1-phenyl. Examples include -4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-methyl-3-pyrazolidone, and 1-phenyl-3-pyrazolidone. Ascorbic acid includes ascorbic acid and its stereoisomer erythorbic acid and its alkali metal salts (sodium and potassium salts). The amount of the reducing agent added is preferably 1.1 times or more of the reaction equivalent in order to completely react the cuprous oxide. The upper limit of the addition amount is not particularly limited, but it is preferably 4 times or less of the reaction equivalent amount from the economical viewpoint.
本発明の第２工程で用いる還元剤は、段階的な還元を行うために複数の還元剤を順に用いてもよい。 The reducing agent used in the second step of the present invention may use a plurality of reducing agents in order in order to perform stepwise reduction.
本発明の第２工程は、図２に示すように亜酸化銅粒子を含む懸濁液に第二還元剤を添加して亜酸化銅粒子と銅超微粒子を含む懸濁液を得る第２−１工程と、亜酸化銅粒子と銅超微粒子を含む懸濁液にヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加して銅微粒子を生成させる第２−２工程からなることが好ましい。 In the second step of the present invention, as shown in FIG. 2, a second reducing agent is added to a suspension containing cuprous oxide particles to obtain a suspension containing cuprous oxide particles and copper ultrafine particles. It consists of 1 process, and the 2nd-2nd process of adding one or more sorts of reducing agents chosen from a hydrazine compound or ascorbic acid to suspension containing cuprous oxide particles and copper ultrafine particles, and generating copper fine particles. preferable.
本発明の第２−１工程で用いる第二還元剤は水素化物であることが好ましい。水素化物としては、例えばアルミニウムハイドライド化合物、ホウ素ハイドライド化合物等を用いることができる。アルミニウムハイドライド化合物としては、水素化リチウムアルミニウム、水素化ジイソプロピルアルミニウムなどが挙げられる。ホウ素ハイドライド化合物としては、水素化ホウ素ナトリウム、水素化ホウ素カリウム、水素化ホウ素リチウム、シアノトリヒドロホウ酸ナトリウム、リチウムトリエチルボロハイドライド、テトラヒドロフラン・ボラン錯体、ジメチルアミン・ボラン錯体、ジフェニルアミン・ボラン錯体、ピリジン・ボラン錯体などが挙げられる。工業的には水素化ホウ素ナトリウムを用いることが好ましい。 The second reducing agent used in step 2-1 of the present invention is preferably a hydride. As the hydride, for example, an aluminum hydride compound, a boron hydride compound, or the like can be used. Examples of the aluminum hydride compound include lithium aluminum hydride and diisopropylaluminum hydride. Examples of boron hydride compounds include sodium borohydride, potassium borohydride, lithium borohydride, sodium cyanotrihydroborate, lithium triethylborohydride, tetrahydrofuran / borane complex, dimethylamine / borane complex, diphenylamine / borane complex, pyridine. -Examples include borane complexes. Industrially, it is preferable to use sodium borohydride.
第二還元剤の添加量は、反応等量の１０−３倍から１０−５倍であることが好ましい。ここで規定する反応等量は、水素化ホウ素塩の１ｍｏｌが亜酸化銅４ｍｏｌと反応することを前提として規定される。水素化ホウ素塩の添加量は、反応液のｐＨや温度、錯化剤濃度と所望する銅粒子の粒子径から適宜選択され、銅粒子の粒子径を本発明所望の大きさに調整する場合、添加する水素化ホウ素塩の添加量は反応等量で１０−３倍から１０−５倍であることが好ましい。水素化ホウ素塩の添加量が反応等量で１０−５倍未満では、銅超微粒子が有意に生成されず、最終的に得られる銅微粒子は比較的大きな粒子となる。反応等量で１０−３倍を超えた場合には、最終的に得られる銅微粒子は０．１μｍ未満の粒子径となるため、酸化しやすく、且つ分散し難いため銅ペースト用の銅粉末として好ましくない。The amount of the second reducing agent added is preferably 10 −3 to 10 −5 times the reaction equivalent. The reaction equivalent defined here is defined on the assumption that 1 mol of borohydride reacts with 4 mol of cuprous oxide. The amount of borohydride added is appropriately selected from the pH and temperature of the reaction solution, the complexing agent concentration and the desired particle size of the copper particles, and when adjusting the particle size of the copper particles to the desired size of the present invention, The amount of borohydride added is preferably 10 −3 to 10 −5 times in terms of reaction equivalent. If the amount of borohydride added is less than 10 −5 times as much as the reaction equivalent, copper ultrafine particles are not significantly produced, and the finally obtained copper fine particles are relatively large particles. When the reaction equivalent exceeds 10 −3 times, the finally obtained copper fine particles have a particle diameter of less than 0.1 μm, so that they are easy to oxidize and difficult to disperse, so as copper powder for copper paste It is not preferable.
本発明の第２−１工程で用いる第二還元剤は、段階的な還元を行うために複数の還元剤を順に用いてもよい。 The second reducing agent used in step 2-1 of the present invention may use a plurality of reducing agents in order to perform stepwise reduction.
本発明の第２−１工程において得られる懸濁液に含まれる亜酸化銅粒子は、本発明の第１工程において得られる懸濁液に含まれる亜酸化銅粒子と同様の、粒子径が揃った分散性に優れる微粒子である。 The cuprous oxide particles contained in the suspension obtained in the step 2-1 of the present invention have the same particle diameter as the cuprous oxide particles contained in the suspension obtained in the first step of the present invention. Fine particles with excellent dispersibility.
本発明の第２−１工程において得られる懸濁液に含まれる銅超微粒子は、粒径が１０ｎｍ以下のコロイド粒子として存在し、第二還元剤添加時のｐＨ、温度によって粒径は変化する。また、添加する第二還元剤の量に応じて粒子の個数が増加する。 The ultrafine copper particles contained in the suspension obtained in step 2-1 of the present invention exist as colloidal particles having a particle size of 10 nm or less, and the particle size varies depending on the pH and temperature when the second reducing agent is added. . Further, the number of particles increases according to the amount of the second reducing agent to be added.
本発明の第２−２工程で用いる還元剤としては、ヒドラジン化合物又はアスコルビン酸から選ばれる１種以上を用いることができる。工業的にはアスコルビン酸を用いることが作業環境の管理が容易なために好ましいが、経済性の観点からはヒドラジンを用いることが好ましい。 As a reducing agent used at the 2-2nd process of this invention, 1 or more types chosen from a hydrazine compound or ascorbic acid can be used. Industrially, ascorbic acid is preferably used because of easy management of the working environment, but hydrazine is preferably used from the viewpoint of economy.
ヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤の添加量は、亜酸化銅を完全に反応させるために、反応等量の１．１倍以上添加することが好ましい。添加量の上限は特に制限されないが、経済的観点から反応等量の４倍以下であることが好ましい。 The addition amount of one or more reducing agents selected from a hydrazine compound or ascorbic acid is preferably 1.1 times or more of the reaction equivalent in order to completely react the cuprous oxide. The upper limit of the addition amount is not particularly limited, but it is preferably 4 times or less of the reaction equivalent amount from the economical viewpoint.
本発明においては、第２工程において、還元剤を添加する懸濁液のｐＨが７．０〜９．５であることが好ましい。 In the present invention, in the second step, the pH of the suspension to which the reducing agent is added is preferably 7.0 to 9.5.
本発明においては、第２工程において還元剤としてアスコルビン酸を用いる場合には、亜酸化銅粒子を含む懸濁液に還元剤を添加した後の懸濁液のｐＨが５．０〜８．０であることが好ましい。第２工程のｐＨが５．０未満では最終的に得られる銅微粒子が相互に連結しやすく、充填性に劣るため銅ペースト用の銅微粒子として好ましくない。またｐＨが８を超えるとアスコルビン酸は還元剤として有意に機能しないので好ましくない。 In the present invention, when ascorbic acid is used as the reducing agent in the second step, the pH of the suspension after adding the reducing agent to the suspension containing cuprous oxide particles is 5.0 to 8.0. It is preferable that If the pH in the second step is less than 5.0, the finally obtained copper fine particles are easy to be connected to each other and poor in filling properties, which is not preferable as copper fine particles for copper paste. On the other hand, if the pH exceeds 8, ascorbic acid does not function significantly as a reducing agent.
また、本発明においては、第２工程において還元剤としてヒドラジン類を用いる場合には、亜酸化銅粒子を含む懸濁液に還元剤を添加した後の懸濁液のｐＨが７．０〜１１．０であることが好ましい。ｐＨが７．０未満ではヒドラジン類は還元剤として有意に機能しないので好ましくない。また第２工程のｐＨが１１を超えると最終的に得られる銅微粒子が相互に連結しやすく、充填性に劣るため銅ペースト用の銅微粒子として好ましくない。 In the present invention, when hydrazines are used as the reducing agent in the second step, the pH of the suspension after addition of the reducing agent to the suspension containing cuprous oxide particles is 7.0 to 11. 0.0 is preferred. If the pH is less than 7.0, hydrazines are not preferable because they do not function significantly as reducing agents. On the other hand, if the pH in the second step exceeds 11, the finally obtained copper fine particles are easily connected to each other and poor in filling properties, which is not preferable as copper fine particles for copper paste.
本発明においては、第２−１工程において、第二還元剤として水素化物を用いる場合には、亜酸化銅を含む懸濁液のｐＨが７．０〜９．５であることが好ましい。懸濁液のｐＨが７．０未満では、例えば水素化ホウ素塩は水素を発生して分解するため、銅超微粒子が有意に生成されず、最終的に得られる銅微粒子は粗大粒子となる。懸濁液のｐＨが９．５を超えるときには、発生した銅超微粒子は凝集しやすいため、最終的に得られる銅微粒子が相互に連結しやすく、充填性に劣るため銅ペースト用の銅微粒子として好ましくない。 In this invention, when using a hydride as a 2nd reducing agent in a 2nd-1 process, it is preferable that the pH of the suspension containing a cuprous oxide is 7.0-9.5. When the pH of the suspension is less than 7.0, for example, a borohydride salt generates hydrogen and decomposes, so that copper ultrafine particles are not significantly generated, and finally obtained copper fine particles are coarse particles. When the pH of the suspension exceeds 9.5, the generated copper ultrafine particles are likely to aggregate, so that the finally obtained copper fine particles are easy to be connected to each other, and have poor filling properties. It is not preferable.
本発明においては、第２−２工程において、還元剤を添加する懸濁液のｐＨが７．０〜９．５であることが好ましい。 In the present invention, in the step 2-2, the pH of the suspension to which the reducing agent is added is preferably 7.0 to 9.5.
本発明においては、第２−２工程において還元剤としてアスコルビン酸を用いる場合には、亜酸化銅粒子と銅超微粒子を含む懸濁液に還元剤を添加した後の懸濁液のｐＨが５．０〜８．０であることが好ましい。第２−２工程のｐＨが５．０未満では最終的に得られる銅微粒子が相互に連結しやすく、充填性に劣るため銅ペースト用の銅微粒子として好ましくない。またｐＨが８を超えるとアスコルビン酸は還元剤として有意に機能しないので好ましくない。 In the present invention, when ascorbic acid is used as the reducing agent in Step 2-2, the pH of the suspension after adding the reducing agent to the suspension containing cuprous oxide particles and copper ultrafine particles is 5 It is preferable that it is 0.0-8.0. If the pH in step 2-2 is less than 5.0, the finally obtained copper fine particles are easy to be connected to each other and are inferior in filling properties, which is not preferable as copper fine particles for copper paste. On the other hand, if the pH exceeds 8, ascorbic acid does not function significantly as a reducing agent.
また、本発明においては、第２−２工程において還元剤としてヒドラジン類を用いる場合には、亜酸化銅粒子と銅超微粒子を含む懸濁液に還元剤を添加した後の懸濁液のｐＨが７．０〜１１．０であることが好ましい。ｐＨが７．０未満ではヒドラジン類は還元剤として有意に機能しないので好ましくない。また第２−２工程のｐＨが１１を超えると最終的に得られる銅微粒子が相互に連結しやすく、充填性に劣るため銅ペースト用の銅微粒子として好ましくない。 In the present invention, when hydrazines are used as a reducing agent in the step 2-2, the pH of the suspension after adding the reducing agent to the suspension containing cuprous oxide particles and copper ultrafine particles. Is preferably 7.0 to 11.0. If the pH is less than 7.0, hydrazines are not preferable because they do not function significantly as reducing agents. On the other hand, when the pH in the step 2-2 exceeds 11, the finally obtained copper fine particles are easily connected to each other and poor in filling properties, which is not preferable as the copper fine particles for the copper paste.
第２工程における反応液の温度は使用する還元剤の種類によって選択される。第２工程の反応が速やかに進行することで粒度分布の揃った銅粉が得られるので、例えばアスコルビン酸を用いる場合は８０℃以上、ヒドラジンを用いる場合は６０℃以上が好ましい。 The temperature of the reaction solution in the second step is selected according to the type of reducing agent used. Since the copper powder having a uniform particle size distribution is obtained by the rapid progress of the reaction in the second step, for example, when ascorbic acid is used, it is preferably 80 ° C. or higher, and when hydrazine is used, 60 ° C. or higher is preferable.
本発明においては、水酸化アルカリを添加した後、第２工程においてヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加するまでの時間は６０分以内であることが好ましい。第２工程においてヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加するまでの時間が６０分を超えると、不均化反応が生じて、最終的に得られる銅粉末に粗大粒子が混入する恐れがある。 In the present invention, it is preferable that the time from the addition of alkali hydroxide to the addition of one or more reducing agents selected from hydrazine compounds or ascorbic acid in the second step is within 60 minutes. When the time until the addition of one or more reducing agents selected from a hydrazine compound or ascorbic acid in the second step exceeds 60 minutes, a disproportionation reaction occurs and coarse particles are formed in the finally obtained copper powder. There is a risk of contamination.
また、本発明においては、水酸化アルカリを添加した後、第２−２工程においてヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加するまでの時間は６０分以内であることが好ましい。第２−２工程においてヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加するまでの時間が６０分を超えると、不均化反応が生じて、最終的に得られる銅粉末に粗大粒子が混入する恐れがある。 Moreover, in this invention, it is preferable that after adding an alkali hydroxide, time until adding 1 or more types of reducing agents chosen from a hydrazine compound or ascorbic acid in a 2nd-2 process is less than 60 minutes. . When the time until the addition of one or more reducing agents selected from a hydrazine compound or ascorbic acid in step 2-2 exceeds 60 minutes, a disproportionation reaction occurs and the copper powder finally obtained is coarse. There is a risk of particle contamination.
本発明の第３工程においては、第２工程を経て得られた懸濁液に含まれる銅微粒子を一般的な方法によって洗浄する。ここで、洗浄液としては、一般的には純水を用いることができるが、洗浄液中での粒子の凝集を促進して沈降を促進し、短時間に回収することで酸化を予防するためには、洗浄液を有機酸水溶液とすることが好ましい。ここで用いる有機酸としてはクエン酸、リンゴ酸、酒石酸、エチレンジアミン４酢酸、アスコルビン酸、グルコン酸等を用いることができるが、得られる銅粉末の酸化をさらに防止して、分散性を向上する観点から、アスコルビン酸類を用いることが好ましい。有機酸水溶液の濃度は、０．０５ｗｔ％から５％が好ましく、０．１％から２％がより好ましい。洗浄、ろ過の工程で酸化を防止することで、乾燥して得られる銅粉末の銅微粒子が相互に凝集することが抑制され、銅粉末の分散性を向上させることができる。 In the third step of the present invention, the copper fine particles contained in the suspension obtained through the second step are washed by a general method. Here, as the cleaning liquid, pure water can be generally used. However, in order to prevent oxidation by promoting aggregation of particles in the cleaning liquid to promote sedimentation and collecting in a short time. The cleaning liquid is preferably an organic acid aqueous solution. As the organic acid used here, citric acid, malic acid, tartaric acid, ethylenediaminetetraacetic acid, ascorbic acid, gluconic acid, and the like can be used, but the viewpoint of further preventing oxidation of the obtained copper powder and improving dispersibility. Therefore, it is preferable to use ascorbic acids. The concentration of the organic acid aqueous solution is preferably 0.05 wt% to 5%, more preferably 0.1% to 2%. By preventing oxidation in the steps of washing and filtration, the copper fine particles of the copper powder obtained by drying are suppressed from aggregating with each other, and the dispersibility of the copper powder can be improved.
そして第３工程において洗浄された銅微粒子を一般的な方法によってろ過、乾燥等を行うことにより、本発明に係る銅粉末を得ることができる And the copper powder which concerns on this invention can be obtained by performing filtration, drying, etc. by the general method for the copper particulates wash | cleaned in the 3rd process.
次に、本発明の製造方法によって得られる銅粉末及び該銅粉末を含む銅ペーストについて述べる。 Next, the copper powder obtained by the production method of the present invention and the copper paste containing the copper powder will be described.
本発明の銅粉末は、ＳＥＭによって観測される銅粒子の平均粒径が０．１μｍから１．３μｍの範囲であることが好ましい。ＳＥＭによって観測される銅粒子の平均粒径は、より好ましくは０．１５μｍから１．０μｍの範囲である。 In the copper powder of the present invention, the average particle diameter of copper particles observed by SEM is preferably in the range of 0.1 μm to 1.3 μm. The average particle diameter of the copper particles observed by SEM is more preferably in the range of 0.15 μm to 1.0 μm.
本発明の銅粉末は、動的光散乱粒度分布測定装置によって観測される銅粉末の平均粒径（Ｄ５０）が０．１μｍから１．５μｍの範囲であることが好ましい。動的光散乱粒度分布測定装置によって観測される銅粉末の平均粒径（Ｄ５０）は、より好ましくは０．１５μｍから１．２μｍの範囲である。 In the copper powder of the present invention, the average particle diameter (D50) of the copper powder observed by a dynamic light scattering particle size distribution measuring device is preferably in the range of 0.1 μm to 1.5 μm. The average particle diameter (D50) of the copper powder observed by the dynamic light scattering particle size distribution analyzer is more preferably in the range of 0.15 μm to 1.2 μm.
本発明の銅粉末は、ＳＥＭによって観測される銅粒子の平均粒径に対する、動的光散乱粒度分布測定装置によって観測される銅粉末の平均粒径（Ｄ５０）の比が５．０以下であることが好ましい。動的光散乱粒度分布測定装置によって観測される凝集粒子の平均粒径の比が５．０より大きい場合には、ＳＥＭによって観測される銅粒子は相互に連結した粒子が多く見られ、充填性に劣るため銅ペースト用の銅粉末として好ましくない。ＳＥＭによって観測される銅粒子の平均粒径に対する、動的光散乱粒度分布測定装置によって観測される銅粉末の平均粒径（Ｄ５０）の比は、より好ましくは２．０以下、さらに好ましくは１．５以下である。 In the copper powder of the present invention, the ratio of the average particle diameter (D50) of the copper powder observed by the dynamic light scattering particle size distribution measuring apparatus to the average particle diameter of the copper particles observed by SEM is 5.0 or less. It is preferable. When the ratio of the average particle size of the aggregated particles observed by the dynamic light scattering particle size distribution analyzer is larger than 5.0, the copper particles observed by the SEM are often connected to each other, and the packing property Therefore, it is not preferable as a copper powder for copper paste. The ratio of the average particle diameter (D50) of the copper powder observed by the dynamic light scattering particle size distribution measuring device to the average particle diameter of the copper particles observed by SEM is more preferably 2.0 or less, and further preferably 1 .5 or less.
本発明の銅粉末は基板上に導電性の塗膜を形成するために用いられる導電性ペースト用の導電性粉末として好適である。 The copper powder of the present invention is suitable as a conductive powder for a conductive paste used to form a conductive coating film on a substrate.
本発明の銅ペーストは通常、銅粉末、溶剤、有機バインダーから成る。各成分の割合は銅粉末１００重量部に対し、溶剤２０〜４００重量部、バインダー樹脂５〜３０重量部の範囲が好ましい。銅ペースト中のバインダー樹脂量が銅粉末１００重量部に対し、５重量部未満では銅ペーストによって形成される塗膜と銅ペーストを塗布する基板との接着性が低下する。 The copper paste of the present invention usually comprises a copper powder, a solvent and an organic binder. The proportion of each component is preferably in the range of 20 to 400 parts by weight of solvent and 5 to 30 parts by weight of binder resin with respect to 100 parts by weight of copper powder. If the amount of the binder resin in the copper paste is less than 5 parts by weight with respect to 100 parts by weight of the copper powder, the adhesion between the coating film formed by the copper paste and the substrate to which the copper paste is applied is lowered.
本発明の銅ペーストに使われる溶剤は、有機バインダーを溶解するものから選ばれ、有機物であっても水であってもよい。溶剤は銅ペースト中で銅粉末を分散させる役割に加えて、分散体の粘度を調整する役割がある。好ましい有機溶剤の例として、アルコール、エーテル、ケトン、エステル、芳香族炭化水素、アミド等が挙げられる。 The solvent used in the copper paste of the present invention is selected from those that dissolve the organic binder, and may be an organic substance or water. The solvent has a role of adjusting the viscosity of the dispersion in addition to the role of dispersing the copper powder in the copper paste. Examples of preferred organic solvents include alcohols, ethers, ketones, esters, aromatic hydrocarbons, amides and the like.
本発明の銅ペーストに使用される有機バインダーとしては、ポリエステル、ポリウレタン、ポリカーボネート、ポリエーテル、ポリアミド、ポリアミドイミド、ポリイミドあるいはアクリル等の樹脂が挙げられる。樹脂中にエステル結合、ウレタン結合、アミド結合、エーテル結合、イミド結合等を有するものが、銅粉末の安定性から好ましい。 Examples of the organic binder used in the copper paste of the present invention include resins such as polyester, polyurethane, polycarbonate, polyether, polyamide, polyamideimide, polyimide, and acrylic. Those having an ester bond, a urethane bond, an amide bond, an ether bond, an imide bond, etc. in the resin are preferred from the stability of the copper powder.
本発明の銅ペーストは、スルフォン酸塩基やカルボン酸塩基等の金属への吸着能力のある官能基を含有するポリマーを含んでもよい。さらに分散剤を配合してもかまわない。分散剤としてはステアリン酸、オレイン酸、ミリスチン酸等の高級脂肪酸、脂肪酸アミド、脂肪酸金属塩、燐酸エステル、スルフォン酸エステル等が挙げられる。分散剤の使用量はバインダー樹脂の０．１〜１０重量％の範囲が好ましい。 The copper paste of the present invention may include a polymer containing a functional group capable of adsorbing to a metal such as a sulfonate group or a carboxylate group. Furthermore, you may mix | blend a dispersing agent. Examples of the dispersant include higher fatty acids such as stearic acid, oleic acid, and myristic acid, fatty acid amides, fatty acid metal salts, phosphoric acid esters, and sulfonic acid esters. The amount of the dispersant used is preferably in the range of 0.1 to 10% by weight of the binder resin.
本発明の銅ペーストには、必要に応じ、硬化剤を配合しても良い。本発明に使用できる硬化剤としてはフェノール樹脂、アミノ樹脂、イソシアネート化合物、エポキシ樹脂等が挙げられる。硬化剤の使用量はバインダー樹脂の１〜５０重量％の範囲が好ましい。 You may mix | blend a hardening | curing agent with the copper paste of this invention as needed. Examples of the curing agent that can be used in the present invention include phenol resins, amino resins, isocyanate compounds, and epoxy resins. The amount of the curing agent used is preferably in the range of 1 to 50% by weight of the binder resin.
銅ペーストを得る方法としては、粉末を液体に分散する一般的な方法を用いることができる。例えば、銅粉末とバインダー樹脂溶液、必要により追加の溶媒からなる混合物を混合した後、超音波法、ミキサー法、３本ロール法、ボールミル法等で分散を施せばよい。これらの分散手段のうち、複数を組み合わせて分散を行うことも可能である。これらの分散処理は室温で行ってもよく、分散体の粘度を下げるために加熱して行ってもよい。 As a method for obtaining the copper paste, a general method for dispersing powder in a liquid can be used. For example, after mixing a mixture of copper powder and a binder resin solution and, if necessary, an additional solvent, dispersion may be performed by an ultrasonic method, a mixer method, a three-roll method, a ball mill method, or the like. Of these dispersing means, a plurality of dispersing means can be combined for dispersion. These dispersion treatments may be performed at room temperature, or may be performed by heating in order to reduce the viscosity of the dispersion.
本発明をさらに詳細に説明するために以下に実施例を挙げるが、本発明は実施例になんら限定されるものではない。なお、実施例に記載された測定値は以下の方法によって測定したものである。 In order to describe the present invention in more detail, examples are given below, but the present invention is not limited to the examples. In addition, the measured value described in the Example is measured by the following method.
ＳＥＭによって観測される銅粒子の平均粒径は、「走査型電子顕微鏡Ｓ−４８００」（株式会社日立ハイテクノロジーズ製）により５０００倍で測定した視野を撮影したＳＥＭ写真より１００個の粒子の粒子径を平均して求めた。粒子の連結がみられる場合は、連結した粒子のくびれ部分で分離したものとして測定した粒子径を平均して求めた。 The average particle diameter of the copper particles observed by SEM is the particle diameter of 100 particles from a SEM photograph taken from a field of view measured at a magnification of 5000 with a "scanning electron microscope S-4800" (manufactured by Hitachi High-Technologies Corporation). Was obtained on average. When particles were connected, the particle diameter measured as separated at the constricted portion of the connected particles was obtained by averaging.
ＳＥＭによって観測される銅粒子の平均粒径の変動係数は、前記測定で得られた１００個の粒子の粒子径の標準偏差と平均との比率を１００分率で示したものである。 The coefficient of variation of the average particle diameter of the copper particles observed by SEM is the ratio of the standard deviation of the particle diameter of the 100 particles obtained by the above measurement to the average, expressed as 100 fractions.
本発明における粗大粒子とは、ＳＥＭによって観測される銅粒子の平均粒径の３倍以上の粒径の粒子である。粗大粒子の数は、「走査型電子顕微鏡Ｓ−４８００」（株式会社日立ハイテクノロジーズ製）により５０００倍で測定した視野を撮影したＳＥＭ写真において数えた。 The coarse particles in the present invention are particles having a particle size of 3 times or more the average particle size of copper particles observed by SEM. The number of coarse particles was counted in the SEM photograph which image | photographed the visual field measured by 5000 times with "scanning electron microscope S-4800" (made by Hitachi High-Technologies Corporation).
動的光散乱粒度分布測定装置によって観測される銅粉末の平均粒径（Ｄ５０）はＳＫレーザーマイクロンサイザーＬＭＳ−２０００ｅ（セイシン企業）により測定した。測定は水を分散媒として、３％ヘキサメタリン酸ナトリウム０．４ｇを分散剤として添加した後、附属の超音分散機により分散しながら適当な散乱強度となるまで銅粉を添加して測定した。 The average particle diameter (D50) of the copper powder observed by a dynamic light scattering particle size distribution measuring device was measured by SK Laser Micron Sizer LMS-2000e (Seishin Enterprise). The measurement was carried out by adding 0.4 g of 3% sodium hexametaphosphate as a dispersion medium using water as a dispersion medium, and then adding copper powder until an appropriate scattering intensity was obtained while dispersing with an attached ultrasonic disperser.
生成した粉体は、粉末Ｘ線回折装置（ＸＲＤ、（株）リガク製、ＲＩＮＴ−２５００）により同定した。 The produced powder was identified by a powder X-ray diffraction apparatus (XRD, manufactured by Rigaku Corporation, RINT-2500).
酸素含量（Ｏ）（重量％）：酸素含量は、示差熱熱重量分析装置「ＴＧ／ＤＴＡ６３００」（セイコーインスツルメント社製）を用いて、２％水素−窒素雰囲気下、２５０℃〜５５０℃の還元重量減少分を求めることで計算して得た。 Oxygen content (O) (% by weight): Oxygen content was measured at 250 ° C. to 550 ° C. in a 2% hydrogen-nitrogen atmosphere using a differential thermothermal gravimetric analyzer “TG / DTA6300” (manufactured by Seiko Instruments Inc.). It was obtained by calculating the reduced weight reduction amount of.
実施例１
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８０９ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。このとき懸濁液のｐＨは８．５であった。（第１工程）得られた橙色の亜酸化銅懸濁液にホウ素化水素ナトリウム０．００５ｇ（５．３×１０−４等量）を容量１００ｍｌの０．０１％水酸化ナトリウム水溶液として添加した。ホウ素化水素ナトリウムの添加は第一工程における水酸化ナトリウムの添加の１０分後であった。懸濁液をさらに、１０分間攪拌して、こげ茶色の亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは８．５であった。（第２−１工程）次に、アスコルビン酸２２５ｇを水酸化ナトリウムで中和してから、この懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間還元反応させ、銅微粒子懸濁液を得た。アスコルビン酸の添加は第一工程における水酸化ナトリウムの添加の２０分後であった。アスコルビン酸による還元反応終了時のｐＨは６．４であった。（第２−２工程）得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例１の銅粉を得た。得られた銅粉の粉末Ｘ線回折より、全て金属銅であることを確認した。また、第一還元反応後に得られる亜酸化銅の懸濁液から、亜酸化銅を少量取り出し洗浄後ＳＥＭ観察を行った。取り出した亜酸化銅は、粒径が０．３μｍ程度の粒度が均一なものであった。また、第２−１工程後に得られる亜酸化銅と銅超微粒子の混合物の懸濁液を少量抜き取り、静置して得た黒色の上澄みをＴＥＭ用のシートメッシュに展開し、ＴＥＭ観察を行ったところ、上澄みには３〜５ｎｍの金属超微粒子が観察された。Example 1
A reaction vessel equipped with a 3 L capacity stirrer was charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), 15 g of glycine, and 1.5 L of water, and heated with stirring to a liquid temperature of 70 ° C. An aqueous copper salt solution was prepared. While stirring this aqueous solution, 809 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out a first reduction reaction. At this time, the pH of the suspension was 8.5. (First step) 0.005 g (5.3 × 10 −4 equivalent) of sodium borohydride was added to the obtained orange cuprous oxide suspension as a 0.01% sodium hydroxide aqueous solution with a capacity of 100 ml. . The addition of sodium borohydride was 10 minutes after the addition of sodium hydroxide in the first step. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of dark brown cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 8.5. (Step 2-1) Next, 225 g of ascorbic acid was neutralized with sodium hydroxide, added to this suspension, heated with stirring, and subjected to a reduction reaction at a liquid temperature of 90 ° C. for 1 hour. A copper fine particle suspension was obtained. The addition of ascorbic acid was 20 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with ascorbic acid was 6.4. (Step 2-2) The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 1 shown in Table 1. From powder X-ray diffraction of the obtained copper powder, it was confirmed that it was all metallic copper. Further, a small amount of cuprous oxide was taken out from the suspension of cuprous oxide obtained after the first reduction reaction, followed by SEM observation after washing. The taken cuprous oxide had a uniform particle size of about 0.3 μm. In addition, a small amount of the suspension of the mixture of cuprous oxide and copper ultrafine particles obtained after the step 2-1 is extracted, and the black supernatant obtained by standing is developed on a sheet mesh for TEM, and TEM observation is performed. As a result, ultrafine metal particles of 3 to 5 nm were observed in the supernatant.
実施例２
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８０９ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。このとき懸濁液のｐＨは８．５であった。得られた橙色の亜酸化銅懸濁液にホウ素化水素ナトリウム０．００７５ｇ（７．９×１０−４等量）を容量１００ｍｌの０．０１％水酸化ナトリウム水溶液として添加した。ホウ素化水素ナトリウムの添加は第一工程における水酸化ナトリウムの添加の１０分後であった。懸濁液をさらに、１０分間攪拌して、こげ茶色の亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは８．５であった。次に、アスコルビン酸２２５ｇを水酸化ナトリウムで中和してから、この懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。アスコルビン酸の添加は第一工程における水酸化ナトリウムの添加の２０分後であった。アスコルビン酸による還元反応終了時のｐＨは６．４であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例２の銅粉を得た。Example 2
A reaction vessel equipped with a 3 L capacity stirrer was charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), 15 g of glycine, and 1.5 L of water, and heated with stirring to a liquid temperature of 70 ° C. An aqueous copper salt solution was prepared. While stirring this aqueous solution, 809 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out a first reduction reaction. At this time, the pH of the suspension was 8.5. To the obtained orange cuprous oxide suspension, 0.0075 g (7.9 × 10 −4 equivalent) of sodium borohydride was added as a 0.01% aqueous sodium hydroxide solution having a capacity of 100 ml. The addition of sodium borohydride was 10 minutes after the addition of sodium hydroxide in the first step. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of dark brown cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 8.5. Next, 225 g of ascorbic acid was neutralized with sodium hydroxide, added to this suspension, heated with stirring, reacted at a liquid temperature of 90 ° C. for 1 hour, and cuprous oxide was reduced to reduce copper. A fine particle suspension was obtained. The addition of ascorbic acid was 20 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with ascorbic acid was 6.4. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 2 shown in Table 1.
実施例３
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８１５ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。このとき懸濁液のｐＨは９．０であった。得られた橙色の亜酸化銅懸濁液にホウ素化水素ナトリウム０．００２ｇ（２．１×１０−４等量）を容量１００ｍｌの０．０１％水酸化ナトリウム水溶液として添加した。ホウ素化水素ナトリウムの添加は第一工程における水酸化ナトリウムの添加の１０分後であった。懸濁液をさらに、１０分間攪拌して、こげ茶色の亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは９．０であった。次に、アスコルビン酸２２５ｇを水酸化ナトリウムで中和してから、この懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。アスコルビン酸の添加は第一工程における水酸化ナトリウムの添加の２０分後であった。アスコルビン酸による還元反応終了時のｐＨは６．４であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例３の銅粉を得た。Example 3
A reaction vessel equipped with a 3 L capacity stirrer was charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), 15 g of glycine, and 1.5 L of water, and heated with stirring to a liquid temperature of 70 ° C. An aqueous copper salt solution was prepared. While stirring this aqueous solution, 815 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out the first reduction reaction. At this time, the pH of the suspension was 9.0. To the obtained orange cuprous oxide suspension, 0.002 g (2.1 × 10 −4 equivalent) of sodium borohydride was added as a 0.01% aqueous sodium hydroxide solution having a volume of 100 ml. The addition of sodium borohydride was 10 minutes after the addition of sodium hydroxide in the first step. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of dark brown cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 9.0. Next, 225 g of ascorbic acid was neutralized with sodium hydroxide, added to this suspension, heated with stirring, reacted at a liquid temperature of 90 ° C. for 1 hour, and cuprous oxide was reduced to reduce copper. A fine particle suspension was obtained. The addition of ascorbic acid was 20 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with ascorbic acid was 6.4. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 3 shown in Table 1.
実施例４
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８１５ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。このとき懸濁液のｐＨは９．０であった。得られた橙色の亜酸化銅懸濁液にホウ素化水素ナトリウム０．００３ｇ（３．１５×１０−４等量）を容量１００ｍｌの０．０１％水酸化ナトリウム水溶液として添加した。ホウ素化水素ナトリウムの添加は第一工程における水酸化ナトリウムの添加の１０分後であった。懸濁液をさらに、１０分間攪拌して、こげ茶色の亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは９．０であった。次に、アスコルビン酸２２５ｇを水酸化ナトリウムで中和してから、この懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。アスコルビン酸の添加は第一工程における水酸化ナトリウムの添加の２０分後であった。アスコルビン酸による還元反応終了時のｐＨは６．４であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例４の銅粉を得た。Example 4
A reaction vessel equipped with a 3 L capacity stirrer was charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), 15 g of glycine, and 1.5 L of water, and heated with stirring to a liquid temperature of 70 ° C. An aqueous copper salt solution was prepared. While stirring this aqueous solution, 815 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out the first reduction reaction. At this time, the pH of the suspension was 9.0. To the obtained orange cuprous oxide suspension, 0.003 g (3.15 × 10 −4 equivalent) of sodium borohydride was added as a 0.01% aqueous sodium hydroxide solution having a capacity of 100 ml. The addition of sodium borohydride was 10 minutes after the addition of sodium hydroxide in the first step. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of dark brown cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 9.0. Next, 225 g of ascorbic acid was neutralized with sodium hydroxide, added to this suspension, heated with stirring, reacted at a liquid temperature of 90 ° C. for 1 hour, and cuprous oxide was reduced to reduce copper. A fine particle suspension was obtained. The addition of ascorbic acid was 20 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with ascorbic acid was 6.4. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 4 shown in Table 1.
実施例５
Ｄ−グルコースの添加量を１９８ｇ（１．１等量）に変更した以外は実施例３と同様にして、表１に示す実施例５の銅粉を得た。Example 5
The copper powder of Example 5 shown in Table 1 was obtained in the same manner as in Example 3 except that the amount of D-glucose added was changed to 198 g (1.1 equivalents).
実施例６
Ｄ−グルコースの添加量を２１６ｇ（１．２等量）に変更し、第一還元反応の時間を６０分に変更した以外は実施例３と同様にして、表１に示す実施例６の銅粉を得た。Example 6
The copper of Example 6 shown in Table 1 was changed in the same manner as in Example 3 except that the amount of D-glucose added was changed to 216 g (1.2 equivalents) and the time of the first reduction reaction was changed to 60 minutes. I got a powder.
実施例７
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８１５ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。得られた橙色の亜酸化銅懸濁液を攪拌しながら２０分間加熱した。このとき懸濁液のｐＨは９．０であった。次に、アスコルビン酸２２５ｇを水酸化ナトリウムで中和してから、この懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。アスコルビン酸の添加は第一工程における水酸化ナトリウムの添加の３０分後であった。アスコルビン酸による還元反応終了時のｐＨは６．４であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例７の銅粉を得た。Example 7
A reaction vessel equipped with a 3 L capacity stirrer was charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), 15 g of glycine, and 1.5 L of water, and heated with stirring to a liquid temperature of 70 ° C. An aqueous copper salt solution was prepared. While stirring this aqueous solution, 815 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out the first reduction reaction. The resulting orange cuprous oxide suspension was heated with stirring for 20 minutes. At this time, the pH of the suspension was 9.0. Next, 225 g of ascorbic acid was neutralized with sodium hydroxide, added to this suspension, heated with stirring, reacted at a liquid temperature of 90 ° C. for 1 hour, and cuprous oxide was reduced to reduce copper. A fine particle suspension was obtained. The addition of ascorbic acid was 30 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with ascorbic acid was 6.4. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 7 shown in Table 1.
実施例８
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８１５ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。このとき懸濁液のｐＨは９．０であった。次にホウ素化水素ナトリウム０．００２ｇ（２．１×１０−４等量）を容量１００ｍｌの０．１％水酸化ナトリウム水溶液として添加した。ホウ素化水素ナトリウムの添加は第一工程における水酸化ナトリウムの添加の１０分後であった。懸濁液をさらに、１０分間攪拌して、亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは９．０であった。次に、懸濁液を攪拌しながら５０℃に冷却し、ヒドラジン１水和物１２０ｇをこの懸濁液に添加し、攪拌しながら加熱して、液温６５℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。ヒドラジンによる還元反応終了時のｐＨは１０．５であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例８の銅粉を得た。Example 8
A reaction vessel equipped with a 3 L capacity stirrer was charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), 15 g of glycine, and 1.5 L of water, and heated with stirring to a liquid temperature of 70 ° C. An aqueous copper salt solution was prepared. While stirring this aqueous solution, 815 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out the first reduction reaction. At this time, the pH of the suspension was 9.0. Next, 0.002 g (2.1 × 10 −4 equivalent) of sodium borohydride was added as a 100% 0.1% aqueous sodium hydroxide solution. The addition of sodium borohydride was 10 minutes after the addition of sodium hydroxide in the first step. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 9.0. Next, the suspension was cooled to 50 ° C. with stirring, 120 g of hydrazine monohydrate was added to the suspension, heated with stirring, reacted at a liquid temperature of 65 ° C. for 1 hour, and suboxidized. Copper was reduced to obtain a copper fine particle suspension. The pH at the end of the reduction reaction with hydrazine was 10.5. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 8 shown in Table 1.
実施例９
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８２４ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。このとき懸濁液のｐＨは９．５であった。次にホウ素化水素ナトリウム０．００２ｇ（２．１×１０−４等量）を容量１００ｍｌの０．１％水酸化ナトリウム水溶液として添加した。ホウ素化水素ナトリウムの添加は第一工程における水酸化ナトリウムの添加の１０分後であった。懸濁液をさらに、１０分間攪拌して、亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは９．５であった。次に、懸濁液を攪拌しながら６０℃に冷却しヒドラジン水和物１００ｇをこの懸濁液に添加し、攪拌しながら加熱して、液温７０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。ヒドラジンの添加は第一工程における水酸化ナトリウムの添加の２０分後であった。ヒドラジンによる還元反応終了時のｐＨは１０．７であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例９の銅粉を得た。Example 9
A reaction vessel equipped with a 3 L capacity stirrer was charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), 15 g of glycine, and 1.5 L of water, and heated with stirring to a liquid temperature of 70 ° C. An aqueous copper salt solution was prepared. While stirring this aqueous solution, 824 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out a first reduction reaction. At this time, the pH of the suspension was 9.5. Next, 0.002 g (2.1 × 10 −4 equivalent) of sodium borohydride was added as a 100% 0.1% aqueous sodium hydroxide solution. The addition of sodium borohydride was 10 minutes after the addition of sodium hydroxide in the first step. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 9.5. Next, the suspension is cooled to 60 ° C. with stirring, 100 g of hydrazine hydrate is added to the suspension, heated with stirring, and allowed to react at a liquid temperature of 70 ° C. for 1 hour. Reduction was performed to obtain a copper fine particle suspension. The addition of hydrazine was 20 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with hydrazine was 10.7. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 9 shown in Table 1.
実施例１０
容量６０Ｌの攪拌装置を設けた反応容器に、硫酸銅８．５ｋｇ、Ｄ−グルコース３．０
６ｋｇ（１．０等量）、グリシン２５５ｇ、水２５．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を攪拌しながら、２６ｗｔ％水酸化ナトリウム溶液１３．７５ｋ
ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。この
とき懸濁液のｐＨは８．５であった。次にホウ素化水素ナトリウム０．０３４ｇ（３．５７×１０−３等量）を容量１．７Ｌの０．１％水酸化ナトリウム水溶液として添加した。ホウ素化水素ナトリウムの添加は第一工程における水酸化ナトリウムの添加の１０分後であった。懸濁液をさらに、１０分間攪拌して、亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは８．５であった。次に、懸濁液を攪拌しながら６０℃に冷却しヒドラジン水和物１．７ｋｇをこの懸濁液に添加し、攪拌しながら加熱して、液温７０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。ヒドラジンの添加は第一工程における水酸化ナトリウムの添加の２０分後であった。ヒドラジンによる還元反応終了時のｐＨは１０．７であった。得られた懸濁液を遠心分離器で脱水後、純水でリパルプしたのち遠心分離器で脱水する工程を繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例１０の銅粉を得た。得られた銅粉の酸素含量は０．５３ｗｔ％であった。Example 10
In a reaction vessel provided with a stirring device with a capacity of 60 L, 8.5 kg of copper sulfate and D-glucose 3.0
6 kg (1.0 equivalent), 255 g of glycine, and 25.5 L of water were charged and heated with stirring to prepare a copper salt aqueous solution having a liquid temperature of 70 ° C. While stirring this aqueous solution, 13.75 k of 26 wt% sodium hydroxide solution
g was added over about 3 minutes, and the mixture was stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out a first reduction reaction. At this time, the pH of the suspension was 8.5. Next, 0.034 g (3.57 × 10 −3 equivalent) of sodium borohydride was added as a 0.1% sodium hydroxide aqueous solution having a capacity of 1.7 L. The addition of sodium borohydride was 10 minutes after the addition of sodium hydroxide in the first step. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 8.5. Next, the suspension was cooled to 60 ° C. with stirring, and 1.7 kg of hydrazine hydrate was added to the suspension, heated with stirring, reacted at a liquid temperature of 70 ° C. for 1 hour, and suboxidized. Copper was reduced to obtain a copper fine particle suspension. The addition of hydrazine was 20 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with hydrazine was 10.7. The obtained suspension was dehydrated with a centrifuge, repulped with pure water, then dehydrated with a centrifuge and washed repeatedly, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 10 shown in Table 1. The obtained copper powder had an oxygen content of 0.53 wt%.
実施例１１
実施例１０と同様にして、銅微粒子懸濁液を得た。得られた懸濁液を遠心分離器で脱水後、１ｗｔ％アスコルビン酸水溶液でリパルプしたのち遠心分離器で脱水する工程を繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す実施例１１の銅粉を得た。得られた銅粉の酸素含量は０．２３ｗｔ％であった。Example 11
In the same manner as in Example 10, a copper fine particle suspension was obtained. The obtained suspension was dehydrated with a centrifuge, repulped with a 1 wt% ascorbic acid aqueous solution, then washed repeatedly with a centrifuge, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Example 11 shown in Table 1. The obtained copper powder had an oxygen content of 0.23 wt%.
比較例１
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。このとき懸濁液のｐＨは２．３であった。この水溶液を撹拌しながら、ホウ素化水素ナトリウム０．００２ｇ（２．１×１０−４等量）を容量１００ｍｌの０．１％水酸化ナトリウム水溶液として添加した。このとき懸濁液のｐＨは２．５であった。次に、アスコルビン酸４００ｇをこの懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間反応させ、銅微粒子懸濁液を得た。アスコルビン酸による還元反応終了時のｐＨは２．６であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す比較例１の銅粉を得た。Comparative Example 1
A reaction vessel provided with a 3 L capacity stirring device was charged with 500 g of copper sulfate, 15 g of glycine and 1.5 L of water, and heated with stirring to prepare a copper salt aqueous solution having a liquid temperature of 70 ° C. At this time, the pH of the suspension was 2.3. While stirring this aqueous solution, 0.002 g (2.1 × 10 −4 equivalent) of sodium borohydride was added as a 0.1% aqueous sodium hydroxide solution having a volume of 100 ml. At this time, the pH of the suspension was 2.5. Next, 400 g of ascorbic acid was added to this suspension, heated while stirring, and reacted at a liquid temperature of 90 ° C. for 1 hour to obtain a copper fine particle suspension. The pH at the end of the reduction reaction with ascorbic acid was 2.6. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Comparative Example 1 shown in Table 1.
比較例２
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、グリシン１５ｇ、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８１５ｇを約３分間かけて添加し、液温８５℃で３０分間攪拌して酸化銅懸濁液を得た。次に、得られた酸化銅懸濁液に、Ｄ−グルコース１８０ｇ（１．０等量）を水１００ｍｌに加えたスラリーを加え、攪拌しながら８５℃に加熱して第一還元反応を行った。このとき懸濁液のｐＨは９．１であった。得られた赤色の亜酸化銅懸濁液に、ホウ素化水素ナトリウム０．００２ｇ（２．１×１０−４等量）を容量１００ｍｌの０．０１％水酸化ナトリウム水溶液として添加した。得られた懸濁液をさらに、１０分間攪拌して、亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは９．１であった。次に、アスコルビン酸２２５ｇを水酸化ナトリウムで中和してから、この懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。アスコルビン酸による還元反応終了時のｐＨは６．４であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す比較例２の銅粉を得た。得られた銅粉は、ＳＥＭ観察の平均粒径は０．２７μｍであるが、粒径が０．２μｍ程度の微粒子と１μｍ程度の大粒子が混在する、粒度が不均一なものであった。また、第一還元反応後に得られる亜酸化銅の懸濁液から、亜酸化銅を少量取り出し洗浄後ＳＥＭ観察を行った。取り出した亜酸化銅は、粒径が０．３μｍ程度の微粒子と０．６〜１μｍの大粒子が混在する、粒度が不均一なものであった。Comparative Example 2
A reaction vessel provided with a 3 L capacity stirring device was charged with 500 g of copper sulfate, 15 g of glycine and 1.5 L of water, and heated with stirring to prepare a copper salt aqueous solution having a liquid temperature of 70 ° C. While stirring this aqueous solution, 815 g of 26 wt% sodium hydroxide solution was added over about 3 minutes and stirred at a liquid temperature of 85 ° C. for 30 minutes to obtain a copper oxide suspension. Next, a slurry obtained by adding 180 g (1.0 equivalent) of D-glucose to 100 ml of water was added to the obtained copper oxide suspension, and the mixture was heated to 85 ° C. with stirring to perform a first reduction reaction. . At this time, the pH of the suspension was 9.1. To the obtained red cuprous oxide suspension, 0.002 g (2.1 × 10 −4 equivalent) of sodium borohydride was added as a 0.01% aqueous sodium hydroxide solution having a capacity of 100 ml. The obtained suspension was further stirred for 10 minutes to obtain a suspension of a mixture of cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 9.1. Next, 225 g of ascorbic acid was neutralized with sodium hydroxide, added to this suspension, heated with stirring, reacted at a liquid temperature of 90 ° C. for 1 hour, and cuprous oxide was reduced to reduce copper. A fine particle suspension was obtained. The pH at the end of the reduction reaction with ascorbic acid was 6.4. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Comparative Example 2 shown in Table 1. The obtained copper powder had an average particle size of 0.27 μm as observed by SEM, but had a non-uniform particle size in which fine particles having a particle size of about 0.2 μm and large particles of about 1 μm were mixed. Further, a small amount of cuprous oxide was taken out from the suspension of cuprous oxide obtained after the first reduction reaction, followed by SEM observation after washing. The taken cuprous oxide was non-uniform in particle size in which fine particles having a particle size of about 0.3 μm and large particles having a particle size of 0.6 to 1 μm were mixed.
比較例３
容量３Ｌの攪拌装置を設けた反応容器に、硫酸銅５００ｇ、Ｄ−グルコース１８０ｇ（１．０等量）、水１．５Ｌを充填し、攪拌しながら加熱して、液温７０℃の銅塩水溶液を調製した。この水溶液を撹拌しながら、２６ｗｔ％水酸化ナトリウム溶液８１５ｇを約３分間かけて添加し、液温８５℃で１０分間攪拌して第一還元反応を行った。得られた橙色の亜酸化銅懸濁液を約１時間かけてろ過、水洗し、亜酸化銅微粒子を得た。得られた亜酸化銅微粒子とグリシン１５ｇを水２Ｌに懸濁し、水酸化ナトリウムでｐＨを９．０に調製した。第一工程における水酸化ナトリウムの添加から懸濁液を調整し終わるまでの時間は約１時間３０分であった。得られた懸濁液に、ホウ素化水素ナトリウム０．００２ｇ（２．１×１０−４等量）を容量１００ｍｌの０．０１％水酸化ナトリウム水溶液として添加した。このとき懸濁液のｐＨは９．２であった。懸濁液をさらに、１０分間攪拌して、亜酸化銅と銅超微粒子の混合物の懸濁液を得た。このとき懸濁液のｐＨは９．２であった。次に、アスコルビン酸２２５ｇを水酸化ナトリウムで中和してから、この懸濁液に添加し、攪拌しながら加熱して、液温９０℃で１時間反応させ、亜酸化銅を還元して銅微粒子懸濁液を得た。アスコルビン酸の添加は第一工程における水酸化ナトリウムの添加の約１時間４０分後であった。アスコルビン酸による還元反応終了時のｐＨは６．４であった。得られた懸濁液を純水でデカンテーションを繰り返して洗浄し、遠心分離によって銅粉ケーキを得た。得られたケーキを真空乾燥機で乾燥して、表１に示す比較例３の銅粉を得た。得られた銅粉は、粒径が０．２μｍ程度の微粒子が一部合一して、粗大粒子様を示した、不均一なものであった。なお、比較例３において、ＳＥＭによって観測される銅粒子の平均粒径は、連結した粒子のくびれ部分で分離したものとして測定した粒子径の平均値を記載した。Comparative Example 3
A reaction vessel equipped with a 3 L capacity stirrer is charged with 500 g of copper sulfate, 180 g of D-glucose (1.0 equivalent), and 1.5 L of water, heated with stirring, and a copper salt with a liquid temperature of 70 ° C. An aqueous solution was prepared. While stirring this aqueous solution, 815 g of 26 wt% sodium hydroxide solution was added over about 3 minutes, and stirred at a liquid temperature of 85 ° C. for 10 minutes to carry out the first reduction reaction. The obtained orange cuprous oxide suspension was filtered and washed with water for about 1 hour to obtain cuprous oxide fine particles. The obtained cuprous oxide fine particles and 15 g of glycine were suspended in 2 L of water, and the pH was adjusted to 9.0 with sodium hydroxide. The time from the addition of sodium hydroxide in the first step to the completion of the suspension was about 1 hour 30 minutes. To the obtained suspension, 0.002 g (2.1 × 10 −4 equivalent) of sodium borohydride was added as a 0.01% aqueous sodium hydroxide solution having a volume of 100 ml. At this time, the pH of the suspension was 9.2. The suspension was further stirred for 10 minutes to obtain a suspension of a mixture of cuprous oxide and copper ultrafine particles. At this time, the pH of the suspension was 9.2. Next, 225 g of ascorbic acid was neutralized with sodium hydroxide, added to this suspension, heated with stirring, reacted at a liquid temperature of 90 ° C. for 1 hour, and cuprous oxide was reduced to reduce copper. A fine particle suspension was obtained. The addition of ascorbic acid was about 1 hour and 40 minutes after the addition of sodium hydroxide in the first step. The pH at the end of the reduction reaction with ascorbic acid was 6.4. The obtained suspension was washed by repeating decantation with pure water, and a copper powder cake was obtained by centrifugation. The obtained cake was dried with a vacuum dryer to obtain the copper powder of Comparative Example 3 shown in Table 1. The obtained copper powder was non-uniform, showing a coarse particle shape, with some of the fine particles having a particle size of about 0.2 μm coalesced. In Comparative Example 3, the average particle diameter of copper particles observed by SEM is the average particle diameter measured as separated at the constricted portions of the connected particles.
本発明の銅粉末の製造方法によれば、銅粒子の粒径をコントロールでき、微細な銅粒子からなる粒度分布の幅の狭い銅粉末を得ることができる。 According to the method for producing copper powder of the present invention, the particle size of copper particles can be controlled, and a copper powder having a narrow particle size distribution width composed of fine copper particles can be obtained.
本発明の銅粉末は、粒度分布の揃った、分散性に優れる、連結粒子や粗大粒子のない銅粉末であるために、導電性インクや導電性ペーストに含有させることで、導電性塗膜形成材料、金属配線材料、導電材料等に好適に用いられる。 Since the copper powder of the present invention is a copper powder having a uniform particle size distribution, excellent dispersibility, and no connected particles or coarse particles, it can be formed into a conductive ink or conductive paste to form a conductive coating film. It is suitably used for materials, metal wiring materials, conductive materials and the like.
Claims (7)
前記亜酸化銅粒子を含む懸濁液に第二還元剤を添加して亜酸化銅粒子と銅超微粒子を含む懸濁液を得る第２−１工程、
前記亜酸化銅粒子と銅超微粒子を含む懸濁液にヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加して銅微粒子を生成させる第２−２工程を含み、前記第二還元剤の添加量が反応等量の１０ −３ 倍から１０ −５ 倍であることを特徴とする銅粉末の製造方法。 A first step of obtaining a suspension containing cuprous oxide particles by adding alkali hydroxide to a mixture of an aqueous copper salt solution having divalent copper ions and a reducing saccharide as a first reducing agent;
Step 2-1 for obtaining a suspension containing cuprous oxide particles and copper ultrafine particles by adding a second reducing agent to the suspension containing cuprous oxide particles,
Including a second step 2-2 in which one or more reducing agents selected from a hydrazine compound or ascorbic acid are added to the suspension containing the cuprous oxide particles and the copper ultrafine particles to form copper fine particles, and the second reduction A method for producing a copper powder, wherein the additive is added in an amount of 10 −3 to 10 −5 times the reaction equivalent .
前記亜酸化銅粒子を含む懸濁液に第二還元剤を添加して亜酸化銅粒子と銅超微粒子を含む懸濁液を得る第２−１工程、
前記亜酸化銅粒子と銅超微粒子を含む懸濁液にヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加して銅微粒子を生成させる第２−２工程を含み、
前記第１工程において水酸化アルカリを添加した後、前記第２−２工程においてヒドラジン化合物又はアスコルビン酸から選ばれる１種以上の還元剤を添加するまでの時間が６０分以内であることを特徴とする銅粉末の製造方法。 A first step of obtaining a suspension containing cuprous oxide particles by adding alkali hydroxide to a mixture of an aqueous copper salt solution having divalent copper ions and a reducing saccharide as a first reducing agent;
Step 2-1 for obtaining a suspension containing cuprous oxide particles and copper ultrafine particles by adding a second reducing agent to the suspension containing cuprous oxide particles,
Including the step 2-2 of adding one or more reducing agents selected from a hydrazine compound or ascorbic acid to the suspension containing the cuprous oxide particles and copper ultrafine particles to produce copper fine particles;
After adding the alkali hydroxide in the first step, the time until adding one or more reducing agents selected from hydrazine compounds or ascorbic acid in the step 2-2 is within 60 minutes. A method for producing copper powder.
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| JP2016131078A (en) * | 2015-01-13 | 2016-07-21 | Ｄｏｗａエレクトロニクス株式会社 | Conductive paste and production method of conductive film using the same |
| JP7081064B2 (en) * | 2016-01-19 | 2022-06-07 | ナミックス株式会社 | Resin compositions, conductive copper pastes, and semiconductor devices |
| JP6103126B1 (en) | 2016-01-29 | 2017-03-29 | 東洋インキＳｃホールディングス株式会社 | Conductive composition, method for producing the same, and conductive material |
| JP2017179428A (en) * | 2016-03-29 | 2017-10-05 | Ｄｏｗａエレクトロニクス株式会社 | Conductive material, forming method of conducive film, circuit board, semiconductor device, and manufacturing method of semiconductor device |
| WO2018025562A1 (en) * | 2016-08-03 | 2018-02-08 | 株式会社Adeka | Method for producing copper powder |
| JP6908398B2 (en) | 2017-03-08 | 2021-07-28 | 株式会社Adeka | Resin composition, method of forming cured product and cured product |
| JP6985219B2 (en) | 2018-07-17 | 2021-12-22 | Ｄｏｗａエレクトロニクス株式会社 | Manufacturing method of spherical silver powder |
| JP6549298B1 (en) * | 2018-09-21 | 2019-07-24 | Ｊｘ金属株式会社 | Pulverizable copper powder and method for producing the same |
| JP7012630B2 (en) * | 2018-11-07 | 2022-01-28 | Ｊｘ金属株式会社 | Copper oxide particles |
| TW202031354A (en) | 2018-12-20 | 2020-09-01 | 日商出光興產股份有限公司 | Method for producing composite supporting metal and metal oxide |
| CN110116218B (en) * | 2019-05-29 | 2022-06-17 | 西安工程大学 | Preparation method of high-purity narrow-particle-size-distribution copper powder |
| CN110919022A (en) * | 2019-08-19 | 2020-03-27 | 张博成 | Preparation method of surface-modified nano-copper particles |
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