JPH0557324B2 - - Google Patents
Info
- Publication number
- JPH0557324B2 JPH0557324B2 JP60240875A JP24087585A JPH0557324B2 JP H0557324 B2 JPH0557324 B2 JP H0557324B2 JP 60240875 A JP60240875 A JP 60240875A JP 24087585 A JP24087585 A JP 24087585A JP H0557324 B2 JPH0557324 B2 JP H0557324B2
- Authority
- JP
- Japan
- Prior art keywords
- copper
- powder
- slurry
- hydrazine
- temperature
- 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.)
- Expired - Lifetime
Links
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 76
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 claims description 57
- 239000002002 slurry Substances 0.000 claims description 52
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 claims description 30
- JJLJMEJHUUYSSY-UHFFFAOYSA-L Copper hydroxide Chemical compound [OH-].[OH-].[Cu+2] JJLJMEJHUUYSSY-UHFFFAOYSA-L 0.000 claims description 28
- 239000005750 Copper hydroxide Substances 0.000 claims description 28
- 229910001956 copper hydroxide Inorganic materials 0.000 claims description 28
- 239000005751 Copper oxide Substances 0.000 claims description 27
- 229910000431 copper oxide Inorganic materials 0.000 claims description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 27
- 238000004519 manufacturing process Methods 0.000 claims description 16
- 229910052802 copper Inorganic materials 0.000 claims description 15
- 239000010949 copper Substances 0.000 claims description 15
- 239000007788 liquid Substances 0.000 claims description 15
- 239000007864 aqueous solution Substances 0.000 claims description 13
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 claims description 12
- 229910001431 copper ion Inorganic materials 0.000 claims description 12
- -1 hydrazine compound Chemical class 0.000 claims description 11
- 239000003513 alkali Substances 0.000 claims description 8
- 239000006228 supernatant Substances 0.000 claims description 7
- 239000011541 reaction mixture Substances 0.000 claims description 5
- 239000002245 particle Substances 0.000 description 50
- 239000000843 powder Substances 0.000 description 34
- 238000006243 chemical reaction Methods 0.000 description 28
- 229960004643 cupric oxide Drugs 0.000 description 25
- 238000009826 distribution Methods 0.000 description 19
- 238000000034 method Methods 0.000 description 16
- 239000000243 solution Substances 0.000 description 16
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 15
- 238000011282 treatment Methods 0.000 description 13
- 150000002429 hydrazines Chemical class 0.000 description 12
- 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 11
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 11
- 230000003647 oxidation Effects 0.000 description 10
- 238000007254 oxidation reaction Methods 0.000 description 10
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- 238000007796 conventional method Methods 0.000 description 9
- 238000006722 reduction reaction Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 235000014113 dietary fatty acids Nutrition 0.000 description 8
- 239000000194 fatty acid Substances 0.000 description 8
- 229930195729 fatty acid Natural products 0.000 description 8
- 150000004665 fatty acids Chemical class 0.000 description 8
- 239000003292 glue Substances 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 5
- 238000001914 filtration Methods 0.000 description 5
- 230000000704 physical effect Effects 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 229910000365 copper sulfate Inorganic materials 0.000 description 4
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 3
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 3
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 3
- 239000005642 Oleic acid Substances 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 229940116318 copper carbonate Drugs 0.000 description 3
- GEZOTWYUIKXWOA-UHFFFAOYSA-L copper;carbonate Chemical compound [Cu+2].[O-]C([O-])=O GEZOTWYUIKXWOA-UHFFFAOYSA-L 0.000 description 3
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 3
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 3
- 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 2
- 239000005749 Copper compound Substances 0.000 description 2
- 229920000084 Gum arabic Polymers 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 241000978776 Senegalia senegal Species 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000000205 acacia gum Substances 0.000 description 2
- 235000010489 acacia gum Nutrition 0.000 description 2
- 238000007259 addition reaction Methods 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 150000001880 copper compounds Chemical class 0.000 description 2
- BERDEBHAJNAUOM-UHFFFAOYSA-N copper(I) oxide Inorganic materials [Cu]O[Cu] BERDEBHAJNAUOM-UHFFFAOYSA-N 0.000 description 2
- KRFJLUBVMFXRPN-UHFFFAOYSA-N cuprous oxide Chemical compound [O-2].[Cu+].[Cu+] KRFJLUBVMFXRPN-UHFFFAOYSA-N 0.000 description 2
- 229940112669 cuprous oxide Drugs 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 229910000377 hydrazine sulfate Inorganic materials 0.000 description 2
- 239000012493 hydrazine sulfate Substances 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 230000001376 precipitating effect Effects 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- OYHQOLUKZRVURQ-NTGFUMLPSA-N (9Z,12Z)-9,10,12,13-tetratritiooctadeca-9,12-dienoic acid Chemical compound C(CCCCCCC\C(=C(/C\C(=C(/CCCCC)\[3H])\[3H])\[3H])\[3H])(=O)O OYHQOLUKZRVURQ-NTGFUMLPSA-N 0.000 description 1
- 241001070941 Castanea Species 0.000 description 1
- 235000014036 Castanea Nutrition 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000003006 anti-agglomeration agent Substances 0.000 description 1
- 230000003064 anti-oxidating effect Effects 0.000 description 1
- 239000012736 aqueous medium Substances 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000000084 colloidal system Substances 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
- DOBRDRYODQBAMW-UHFFFAOYSA-N copper(i) cyanide Chemical compound [Cu+].N#[C-] DOBRDRYODQBAMW-UHFFFAOYSA-N 0.000 description 1
- SVOAENZIOKPANY-CVBJKYQLSA-L copper;(z)-octadec-9-enoate Chemical compound [Cu+2].CCCCCCCC\C=C/CCCCCCCC([O-])=O.CCCCCCCC\C=C/CCCCCCCC([O-])=O SVOAENZIOKPANY-CVBJKYQLSA-L 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 239000011521 glass Substances 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
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000013067 intermediate product Substances 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 235000021313 oleic acid Nutrition 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229910000027 potassium carbonate Inorganic materials 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000012279 sodium borohydride Substances 0.000 description 1
- 229910000033 sodium borohydride Inorganic materials 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 238000009777 vacuum freeze-drying Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
Description
〔産業上の利用分野〕
この発明は、湿式法による銅微粉末の製造法に
関し、より詳細には粒度分布幅が小さく、良好な
粒径に制御された銅微粉末を製造する方法に関す
る。
〔従来技術およびその問題点〕
近時、銅微粉末は電子工業分野において、金、
銀、白金、パラジウム等の貴金属に替つて、その
価格の安定性、優れた電気的特性のために厚膜回
路用導電性ペースト材料として実用化されつつあ
る。ペースト材料として銅粉に要求される特性と
しては、適度な粒度分布を持つ微粉（通常〜3μm
以下）であること、分散性に優れていること、相
互接触しやすい形状（粒状が好ましい）であるこ
と、耐酸化性があり高純度であること等である。
銅微粉末を得る従来の方法としては種々の方法
が提案されている。微粉末の定義は確立されてい
る訳ではないが、本発明に関連する粒径範囲であ
る約5μm以下の平均粒径を持つ銅微粉の製造方法
としては、熔融銅を霧化させるアトマイズ法、陰
極上への電解析出法、および銅を機械的に粉砕す
る方法などがある。しかしながら、上記の従来方
法は平均粒径が通常10μm以上と大きく製造後何
らかの分級操作を加えて初めて5μm以上の画分が
得られ、それも粒度分布が広くしかも粒径制御が
困難であるといつたペースト用材料として使用す
るには欠点がある粉末しか製造できない。
また、次のように不活性ガス中で銅を強制蒸発
させるいわゆるガス中蒸発法、プラズマ炎中に銅
粗粉を吹込んで揮発凝集させるプラズマ炎法、水
素富化ガス中でアークプラズマにより製造するい
わゆる水素プラズマ法、および銅イオン溶液に水
素化ホウ素ナトリウムを加えて銅超微粉末を還元
析出させる方法（特開昭58−224103）などの従来
方法は、平均粒径が通常0.1μm以下と小さく、崇
高で、比表面積が大きくて酸化しやすくしかも吸
油量が大きいという欠点がある。また設備が高価
で量産性に乏しいという欠点もある。
さらに、炭酸銅の溶液からヒドラジンにより還
元析出される従来方法（特開昭59−12723）は、
固体炭酸銅を含む銅の溶液に限定されている。と
ころで、銅イオンがヒドラジンあるいはヒドラジ
ン化合物により還元されて金属銅として析出する
ことは公知であるが（新実験化学講座8.「無機化
合物の合成(1)」発行 東京化学同人）、これらの
ヒドラジン（化合物）による銅イオンの還元方法
によると微細な銅粉末も得られるのが粒度分布が
広く、しかも片状の粗大析出物が混入し、崇高
で、形状も不規則であり、しかも粒径の制御が困
難で一定品質の銅粉末が得られにくいという欠点
がある。
最近になつて提案された従来方法には酸化銅粉
末とヒドラジン類との還元反応により銅粉末に析
出させる方法がある（特開昭59−16303号公報）。
しかしながら、反応系内に水溶性高分子化合物の
保護コロイドを初めから共存させておくこと、お
よび均一かつ微細な所望の銅粉末を得るためには
出発原料の酸化銅も均一かつ微細なものを準備す
ることが必要である。
この発明はこれらの従来方法の問題点を解消す
べくなされたものであり、その目的は約3μm以下
の適宜の粒径に容易に制御することができるとと
もに、粒度分布幅の小さい粉末を製造することが
できる方法を提供することである。
〔問題点を解決するための手段〕
本発明者らは、種々の研究を重ねた結果、銅イ
オン含有水溶液とアルカリを、PHを３〜７に、液
温を20〜60℃に維持しながら、反応させてえられ
た反応混合物からなる水酸化銅スラリーに、その
スラリーのPHを３〜６に、温度を30〜90℃に維持
しながら、ヒドラジンおよび／またヒドラジン化
合物を、酸化銅を生成するに必要な理論量の１〜
３倍量添加して酸化銅スラリーをつくり、静置後
このスラリーの上澄液を除去し、新たに水を添加
し、更にそのスラリーの温度を30〜80℃に維持し
ながら、ヒドラジンおよび／またはヒドラジン化
合物を、酸化銅を金属銅に還元するに必要な理論
量の１〜３倍量添加して銅粉末に還元折出させる
ことを特徴とする銅粉末の製造法。によつて、こ
の発明の目的を達成しうることを見出してこの発
明を完成するに至つた。
この発明の好ましい態様として、得られた銅粉
末をアルコールで、更に必要に応じて脂肪酸溶液
で後処理することができる。
この発明の好ましい別の態様として、得られた
銅粉末を順次ニカワ液、水、アルコールで、更に
必要に応じて脂肪酸溶液で後処理することができ
る。
以下、この発明をより具体的に説明する。
水酸化銅スラリー
この発明により銅粉末の製造法において用いら
れる水酸化銅スラリーは、粉状水酸化銅が水性媒
体中で分散したものである。このスラリーの調整
は、銅イオン含有水溶液にアルカリを添加して水
酸化銅スラリー（反応混合物）を得ることによつ
て行なう。
これは、例えば約10ミクロンの粒径の“栗のい
が”状で粒度の揃つたスラリーが得られるからで
ある。このスラリー中の水酸化銅は、微細であり
かつ粒度の揃つたものが望ましい。
水酸化銅スラリーの調整のために、銅イオン含
有水溶液とアルカリとの反応混合物を用いる場
合、銅イオン含有水溶液としては、銅イオンとし
て含有する溶液であればその種類を特に限定され
ないが、入手容易な硫酸銅、硝酸銅、塩化銅およ
びシアン化銅などの水溶液を用いることができ
る。この発明において銅イオンは１価または２価
であり、溶液中の形態、例えば鎖体などの形態に
限定されない。水酸化物スラリーの調製において
用いるアルカリには、水酸化ナトリウム、水酸化
カリウム、アンモニア、炭酸ナトリウム、炭酸カ
リウムなどがあり、好ましくはアンモニアであ
る。水酸化銅スラリーの調製にあたつて液温を20
℃〜60℃に保持することが必要である。20℃未満
では水酸化銅スラリーの生成が不十分であり、他
方60℃を超えると水酸化銅スラリーの再溶解を招
くおそれがあるからである。同様に反応系中にお
けるPHは３〜７であり、より好ましくは４〜6.5
である。これは、PHが３未満の強い酸性領域では
水酸化銅の生成が困難であり、７を超えるPHでは
水酸化銅の再溶解が起るからである。銅イオン含
有水溶液の濃度は、溶液の種類、アルカリの種
類、所望の水酸化銅粉末の粒径などのパラメータ
に応じて適宜変更することが望ましい。
酸化銅スラリー
この発明におけるヒドラジンおよびヒドラジン
化合物は、第１に水酸化銅スラリーから酸化銅ス
ラリーを得るのに用いられる。この方法に用いる
ことのできるヒドラジン化合物としては、抱水ヒ
ドラジン、無水ヒドラジン、硫酸ヒドラジンなど
種々の化合物がある。これらヒドラジンおよびヒ
ドラジン化合物はヒドラジン単独、ヒドラジン化
合物単独、もしくはヒドラジンとヒドラジン化合
物の混合物、またこれらと溶媒との混合液として
反応に供される。例えば、抱水ヒドラジンが好ま
しい。酸化銅スラリー生成に用いられるヒドラジ
ンなどの添加量は、その生成に必要な論理量の１
〜３倍量である。これは論理量未満では反応が完
結せず未反応の銅化合物が残留し、３倍量を超え
ると過剰のヒドラジンが浪費されて経済的でない
からである。いずれにしてもヒドラジン（ヒドラ
ジン化合物）の添加量は、ヒドラジン添加反応時
の温度、PHおよび所望の反応完結時間に応じて適
切に決定されることが望ましい。
この発明における銅酸化物スラリーは、水酸化
銅スラリーにヒドラジンおよび／またはヒドラジ
ン化合物を添加して得られたものであり、銅の酸
化状態は、１価および１または２価であり、好ま
しくはこの酸化物は実質的に亜酸化銅である。
水酸化銅粉末をヒドラジン類と反応させること
により水酸化銅粒子の約10分の１の粒径を有する
ものとなると考えられる。したがつて、酸化銅ス
ラリー調製に際して用いられる水酸化銅スラリー
は、所望の銅粉末の粒径を得るために、均一かつ
微細な水酸化銅粒子を含有することが望ましい。
銅イオン含有液とアルカリとの反応混合物をその
ままこの反応の水酸化銅スラリーとして使用する
こどができるが、水酸化銅粒子の粒径および濃度
の制御を行つた後に反応に供にしてもよい。この
制御によつてより良好な粒度および粒径分布を有
する銅粉末を得ることが可能となる。酸化銅スラ
リー調製において、水酸化銅スラリーの液温を30
〜90℃、好ましくは40〜80℃に維持することが必
要である。これは温度が30℃未満であると反応速
度を遅らせて生成する粉末を凝集させ、逆に90℃
を超えると反応が激しく起こつて得られる粉末の
粒度分布が広くなると同時に粒子の粗大化が起こ
るからである。酸化銅スラリー調製において、水
酸化スラリーのPHを３〜６に酸またはアルカリを
添加して調節することが望ましい。これはこのPH
範囲から外れると反応生成物の収率が低下して好
ましくないからである。
銅粉末の析出
この発明において銅粉末は、酸化銅スラリーと
ヒドラジンおよび／またはヒドラジン化合物とを
反応させ、還元析出させて得られる。
この反応において用いられる酸化銅スラリー
は、所望の銅粉末の粒度および粒度分布とするた
めに、均一かつ微細な酸化銅粒子を含有すること
が望ましい。水酸化銅スラリーとヒドラジン類を
反応させて第一段階の還元反応を行なつた後はえ
られた酸化銅スラリーを静置して上澄液を除去し
た後それとほぼ同量の水を新たに加えてからヒド
ラジン類を加えて第二段階の還元反応を行なわせ
る。本発明ではこのように還元反応を二段階で行
ない、第一段階では水酸化銅スラリーにヒドラジ
ン類を添加して還元反応を行なつて酸化銅スラリ
ーを得、次にこの酸化銅スラリーを静置し上澄液
を除去し新たに水を加えてから再度ヒドラジン類
を加えて第二段階の還元反応を行なわせて銅粉末
を製造するのである。このようにすることによつ
て粒度分布幅が小さく分散性の良好な銅微粉末を
得ることができるのである。
この発明においてヒドラジンおよび／またはヒ
ドラジン化合物は、第２に酸化銅スラリー粉末を
得るのに用いられる。この段階で用いられるヒド
ラジン化合物としては、抱水ヒドラジン、硫酸ヒ
ドラジン、無水ヒドラジンなど種々の化合物があ
るが、好ましい化合物は抱水ヒドラジンである。
これらヒドラジン類は単独もしく溶液として反応
に供される。銅粉末の析出に用いられるヒドラジ
ン類の添加量は、その析出に必要な理論量の１〜
３倍量である。これは理論量未満では反応が完結
せず、未反応の銅化合物が残留し、逆に３倍量を
超えるとヒドラジン類が過剰に残留し非経済的だ
からである。いずれにしても、ヒドラジン類の添
加量は、ヒドラジン添加反応時の温度、PHおよび
所望の完結時間に応じて適切に決定される。
銅粉析出において、酸化銅スラリーの温度を30
〜80℃に設定する。これは、30℃未満では反応速
度が遅くて生成粉末の凝集が大きくなり、一方80
℃を超えると反応が激しくて得られる銅粉末の粒
度分布が広くなると同時に粒子が粗大化するため
である。
銅粉末の後処理
この発明において還元析出された銅粉末は、通
常の自然重力ロ過あるいは減速ロ過による固液分
離および水洗浄の後、必要に応じて後処理に施さ
れる。この発明において好ましい後処理として次
の態様を挙げることができ、この処理後に分散状
態の銅粉末を得る。
(a) 銅粉末をアルコールで処理する。
(b) 銅粉末をニカワ、水、アルコールで順次処理
する。
(c) 銅粉末をアルコール、脂肪酸で処理する。
(d) 銅粉末をニカワ、水、アルコール、脂肪酸で
順次処理する。
この後処理で用いられるアルコールは、銅粉末
の表面に付着した水分を置換除去するために使用
され、その目的に反しない限りアルコールの種類
は限定されない。この発明において好ましいアル
コールにはメタノール、エタノールがある。
この後処理で用いられるニカワは、銅粉末の凝
集を抑制して粉末の崇密度を高めるために使用さ
れる。この操作においてニカワ水溶液の濃度は例
えば0.5〜1.0g／であり、その添加量は銅粉末
重量に対して例えば0.1〜0.5重量％である。
この後処理において、アルコールによる水分除
去の後に、必要に応じて銅微粉末に脂肪酸を添加
処理し、銅粉末に耐酸化性を付与することができ
る。
この操作において使用する脂肪酸はステアリン
酸、オレイン酸、リノール酸等、好ましくはオレ
イン酸を濃度0.1〜0.5容量％のアルコール溶液と
して銅微粉末に対し0.005〜0.2重量％添加処理す
る。脂肪酸は単なる表面吸着だけでなく、例えば
オレイン酸銅といつた保護膜を形成し耐酸化性の
機能を付与するものと考える。
この様にして得られた銅微粉末は真空乾燥、凍
結乾燥等の特殊な乾燥法を使用することなく、通
常の乾燥法にて温度60〜90℃で乾燥することによ
つて直径3μm以下の高純度銅微粉末とすることが
できる。
〔発明の作用および効果〕
この発明の製造法によつて次のような作用・効
果を得ることができる。
(a) この発明の製造法によつて、約3μm以下の適
度の粒径および狭い粒度分布幅を有する銅微粉
末を得ることができる。これは、反応の機構は
必ずしも明らかではないが、この発明の製造方
法の各段階における反応が溶液中もしくはスラ
リー中で行なわれることおよび銅粉末の形成反
応が、直接に一段階で行なうのではなく、多段
階的に行なわれるためだと考えられる。
(b) この発明の方法のそれぞれの段階で中間生成
物の粉末物性を制御することにより最終的な銅
微粉末の物性を制御できるので、従来方法（特
開昭59−116303号）で必要とされるような凝集
防止材などの処理剤を反応の初めから添加して
粉末の物性を制御する必要がなく、しかも処理
剤の後工程への影響が起こりえない。
(c) 最終的に銅微粉末が生成した後で酸化防止処
理等の後処理を行えるので、これら後処理を制
御することにより多方面の用途に適した銅粉を
つくることができる。即ち本発明の銅粉の主た
る用途とした厚膜導電ペースト用以外の用途に
おいて本発明の後処理が不要あるいは悪影響を
及ぼす場合には該後処理を省略して膠あるいは
脂肪酸を付着させずに、例えば不活性ガス雰囲
気を保つて酸化させないようにして次の用途に
供することもできる、発明の初めから処理剤を
共存させる従来技術ではこのような多様性が得
られない。
(d) この発明の製造法において、原料はいずれも
入手が容易でありかつ取扱いも容易であり、反
応条件はいずれも穏やかであり、スラリーまた
は溶液中で反応が行なわれるので簡単な設備で
この製造法を実施することができる。
以上のごとく、本発明によると、従来困難とさ
れていた直径３ミクロン以下の銅微粉末を簡単な
設備で大量に高収率で製造できるという効果を有
する。さらに電子部品用ペースト材料として必要
な粒度分布幅の小さい、分散性の良好な、低比表
面積、高タツプで耐酸化性を有する高純度微粉末
であるといつた特性をも有する。
〔実施例〕
以下この説明を実施例に基づいてさらに具体的
に説明する。しかしながら、この例はこの発明の
理解のためであり、この発明の範囲をこの例に限
定しようとするものではない。
実施例 １
硫酸銅80Kgを水に溶解し、温度を40℃に保持し
ながらアンモニア水を添加し、水溶液のPHを4.0
に調製し銅水酸化物スラリーを形成後、水を添加
し全液量を160リツトルとする。
次いで温度を50℃、PH4.0を保持しながら抱水
比6.01Kg（理論量1.5倍）を添加し、60分間反応
させ酸化銅スラリーを生成させる。反応終了後60
分間静置し、上澄液を除去し、水を添加し全液量
を160リツトルとする。
次に温度50℃を保持しながら、抱水ヒドラジン
8.01Kg（理論量の２倍）を添加し、60分間反応さ
せる。これにより酸化銅は還元されて金属銅粉末
となる。
次いでこれを自然重力濾過器により濾過し、水
にて洗浄後、膠濃度0.5g／の膠溶液40リツトル
を通液濾過（水にて通液洗浄濾過、メタノール18
リツトルにて通液濾過、オレイン酸濃度0.2容量
％のメタノール溶液９リツトルにて通液濾過）の
各処理をした後、温度80℃の通常雰囲気で乾燥し
銅微粉末20Kgを得た。この収率は98％であつた。
得られた銅微粉末は分散性の良好な粒度分布幅
の小さい、粒径1.25ミクロン（最大粒子径２ミク
ロン以下）、比表面積0.73m2／gr、タツプ密度
3.68g／c.c.、酸素品位0.26％の不純物を殆んど含
まない高純度銅微粉末であつた。
この粉末を大気中に４ケ月間放置後の酸素品位
には殆んど変化はみられず、耐酸化性の優れた粉
末であることがわかる。
また、この粉末をガラスフリツト、有機バイン
ダー、有機溶剤とともに混練し銅ペーストとした
ものをアルミナ基板にスクリーン印刷し窒素雰囲
気中で焼成したものは優れたハンダ付け性、接着
強度、電気伝導性を有し、経時変化も少なく厚膜
回路として充分に特性を満足するものであつた。
本実施例において、酸化銅スラリーの上澄液除
去、新しい水の添加とその繰返しにより生成した
銅粉末の物性を測定したところ次のような結果が
えられた。これにより各種物性を制御しうること
が明らかである。
[Industrial Field of Application] The present invention relates to a method for producing fine copper powder by a wet method, and more particularly to a method for producing fine copper powder having a narrow particle size distribution and a well-controlled particle size. [Prior art and its problems] Recently, fine copper powder has been used in the electronic industry as gold,
It is being put into practical use as a conductive paste material for thick film circuits in place of precious metals such as silver, platinum, and palladium due to its stable price and excellent electrical properties. The characteristics required of copper powder as a paste material are fine powder with an appropriate particle size distribution (usually ~3 μm).
(below), have excellent dispersibility, have a shape (preferably granular) that allows easy mutual contact, and have oxidation resistance and high purity. Various methods have been proposed as conventional methods for obtaining fine copper powder. Although the definition of fine powder is not established, methods for producing fine copper powder having an average particle size of approximately 5 μm or less, which is the particle size range relevant to the present invention, include an atomization method in which molten copper is atomized; Examples include electrolytic deposition on the cathode and mechanical crushing of copper. However, in the conventional method described above, the average particle size is usually 10 μm or more, and a fraction of 5 μm or more cannot be obtained until some sort of classification operation is added after production, and the particle size distribution is wide and particle size control is difficult. Only powders can be produced that have drawbacks for use as materials for pastes. In addition, the following methods are available: the so-called in-gas evaporation method in which copper is forcibly evaporated in an inert gas, the plasma flame method in which coarse copper powder is blown into a plasma flame to volatilize and agglomerate it, and the arc plasma method in a hydrogen-enriched gas. Conventional methods such as the so-called hydrogen plasma method and a method in which sodium borohydride is added to a copper ion solution to reduce and precipitate ultrafine copper powder (Japanese Patent Application Laid-open No. 58-224103) have a small average particle size of usually 0.1 μm or less. , has the drawbacks of having a large specific surface area, being easily oxidized, and having a large oil absorption capacity. Another disadvantage is that the equipment is expensive and mass production is poor. Furthermore, the conventional method (Japanese Unexamined Patent Publication No. 12723/1983) in which copper carbonate is reduced and precipitated from a solution with hydrazine,
Limited to copper solutions containing solid copper carbonate. By the way, it is known that copper ions are reduced by hydrazine or hydrazine compounds and precipitated as metallic copper (New Experimental Chemistry Course 8. "Synthesis of Inorganic Compounds (1)" published by Tokyo Kagaku Dojin). According to the reduction method of copper ions using a compound), fine copper powder can be obtained, but the particle size distribution is wide, and flaky coarse precipitates are mixed, sublime, and the shape is irregular, and it is difficult to control the particle size. The drawback is that it is difficult to obtain copper powder of consistent quality. A recently proposed conventional method involves depositing copper powder through a reduction reaction between copper oxide powder and hydrazines (Japanese Unexamined Patent Publication No. 16303/1983).
However, in order to coexist a protective colloid of a water-soluble polymer compound in the reaction system from the beginning, and to obtain the desired uniform and fine copper powder, the starting material copper oxide must also be prepared in a uniform and fine form. It is necessary to. This invention was made to solve the problems of these conventional methods, and its purpose is to easily control the particle size to an appropriate particle size of about 3 μm or less and to produce powder with a narrow particle size distribution. The purpose is to provide a method that can be used. [Means for Solving the Problems] As a result of various studies, the present inventors have developed an aqueous solution containing copper ions and an alkali while maintaining the pH at 3 to 7 and the liquid temperature at 20 to 60°C. , while maintaining the pH of the slurry at 3 to 6 and the temperature at 30 to 90°C, producing hydrazine and/or hydrazine compounds and copper oxide in the copper hydroxide slurry consisting of the reaction mixture obtained by the reaction. The theoretical quantity required to
A copper oxide slurry is prepared by adding 3 times the amount of copper oxide, and after standing still, the supernatant liquid of this slurry is removed, water is newly added, and while maintaining the temperature of the slurry at 30 to 80°C, hydrazine and/or Alternatively, a method for producing copper powder, which comprises adding a hydrazine compound in an amount of 1 to 3 times the theoretical amount required to reduce copper oxide to metallic copper, and reducing and precipitating it into copper powder. The inventors discovered that the object of the invention can be achieved and completed the invention. In a preferred embodiment of the invention, the obtained copper powder can be post-treated with alcohol and, if necessary, with a fatty acid solution. As another preferred embodiment of the present invention, the obtained copper powder can be post-treated sequentially with glue solution, water, alcohol, and further with a fatty acid solution if necessary. This invention will be explained in more detail below. Copper Hydroxide Slurry The copper hydroxide slurry used in the method for producing copper powder according to the present invention is one in which powdered copper hydroxide is dispersed in an aqueous medium. This slurry is prepared by adding an alkali to an aqueous solution containing copper ions to obtain a copper hydroxide slurry (reaction mixture). This is because a "chestnut burr"-like slurry with a uniform particle size, for example about 10 microns, can be obtained. The copper hydroxide in this slurry is preferably fine and of uniform particle size. When using a reaction mixture of a copper ion-containing aqueous solution and an alkali to prepare a copper hydroxide slurry, the type of copper ion-containing aqueous solution is not particularly limited as long as it contains copper ions, but it is easily available. Aqueous solutions of copper sulfate, copper nitrate, copper chloride, copper cyanide, and the like can be used. In this invention, the copper ion is monovalent or divalent, and is not limited to the form in solution, for example, the form of a chain. The alkali used in the preparation of the hydroxide slurry includes sodium hydroxide, potassium hydroxide, ammonia, sodium carbonate, potassium carbonate, etc., with ammonia being preferred. When preparing copper hydroxide slurry, lower the liquid temperature to 20°C.
It is necessary to maintain the temperature between ℃ and 60℃. This is because if the temperature is lower than 20°C, the production of copper hydroxide slurry is insufficient, and if the temperature exceeds 60°C, the copper hydroxide slurry may be redissolved. Similarly, the pH in the reaction system is 3 to 7, more preferably 4 to 6.5.
It is. This is because it is difficult to produce copper hydroxide in a strongly acidic region with a pH of less than 3, and re-dissolution of copper hydroxide occurs in a pH of more than 7. It is desirable to change the concentration of the copper ion-containing aqueous solution as appropriate depending on parameters such as the type of solution, the type of alkali, and the desired particle size of the copper hydroxide powder. Copper Oxide Slurry Hydrazine and hydrazine compounds in this invention are first used to obtain a copper oxide slurry from a copper hydroxide slurry. Hydrazine compounds that can be used in this method include various compounds such as hydrazine hydrate, anhydrous hydrazine, and hydrazine sulfate. These hydrazine and hydrazine compounds are subjected to the reaction as hydrazine alone, as a hydrazine compound alone, as a mixture of hydrazine and a hydrazine compound, or as a mixture of these and a solvent. For example, hydrazine hydrate is preferred. The amount of added hydrazine, etc. used in the production of copper oxide slurry is 1 of the theoretical amount necessary for its production.
~3 times the amount. This is because if the amount is less than the theoretical amount, the reaction will not be completed and unreacted copper compounds will remain, and if the amount exceeds three times the amount, excess hydrazine will be wasted, which is not economical. In any case, the amount of hydrazine (hydrazine compound) added is desirably determined appropriately depending on the temperature and pH during the hydrazine addition reaction and the desired reaction completion time. The copper oxide slurry in this invention is obtained by adding hydrazine and/or a hydrazine compound to a copper hydroxide slurry, and the oxidation state of copper is monovalent and monovalent or divalent. The oxide is essentially cuprous oxide. It is believed that by reacting copper hydroxide powder with hydrazines, the powder has a particle size about one-tenth that of copper hydroxide particles. Therefore, the copper hydroxide slurry used in preparing the copper oxide slurry desirably contains uniform and fine copper hydroxide particles in order to obtain the desired copper powder particle size.
The reaction mixture of the copper ion-containing liquid and the alkali can be used as it is as the copper hydroxide slurry for this reaction, but it may also be used for the reaction after controlling the particle size and concentration of the copper hydroxide particles. . This control makes it possible to obtain copper powder with better particle size and particle size distribution. When preparing copper oxide slurry, the liquid temperature of copper hydroxide slurry was
It is necessary to maintain the temperature at ~90°C, preferably between 40 and 80°C. This is because if the temperature is below 30℃, the reaction rate will be slowed down and the resulting powder will agglomerate;
This is because, if it exceeds this, the reaction will occur violently, and the particle size distribution of the obtained powder will become broader, and at the same time, the particles will become coarser. In preparing copper oxide slurry, it is desirable to adjust the pH of the hydroxide slurry to 3 to 6 by adding acid or alkali. This is this PH
This is because if it deviates from this range, the yield of the reaction product will decrease, which is undesirable. Precipitation of Copper Powder In the present invention, copper powder is obtained by reacting a copper oxide slurry with hydrazine and/or a hydrazine compound, and reducing and precipitating the reaction. The copper oxide slurry used in this reaction desirably contains uniform and fine copper oxide particles in order to obtain the desired particle size and particle size distribution of the copper powder. After the first stage reduction reaction is performed by reacting the copper hydroxide slurry with hydrazines, the resulting copper oxide slurry is allowed to stand, the supernatant liquid is removed, and approximately the same amount of water is added. After the addition, hydrazines are added to carry out the second stage reduction reaction. In the present invention, the reduction reaction is performed in two stages as described above, and in the first stage, hydrazines are added to the copper hydroxide slurry to perform the reduction reaction to obtain a copper oxide slurry, and then this copper oxide slurry is allowed to stand still. Then, the supernatant liquid is removed, water is added, and hydrazine is added again to carry out the second-stage reduction reaction to produce copper powder. By doing so, it is possible to obtain fine copper powder with a small particle size distribution width and good dispersibility. In this invention, hydrazine and/or a hydrazine compound is secondly used to obtain a copper oxide slurry powder. The hydrazine compound used in this step includes various compounds such as hydrazine hydrate, hydrazine sulfate, and anhydrous hydrazine, but the preferred compound is hydrazine hydrate.
These hydrazines can be used alone or in the form of a solution for the reaction. The amount of hydrazine added used for precipitation of copper powder is 1 to 1 of the theoretical amount required for the precipitation.
That's three times the amount. This is because if the amount is less than the theoretical amount, the reaction will not be completed and unreacted copper compounds will remain, whereas if the amount exceeds three times the amount, an excessive amount of hydrazine will remain, which is uneconomical. In any case, the amount of hydrazines added is appropriately determined depending on the temperature and pH during the hydrazine addition reaction and the desired completion time. During copper powder precipitation, the temperature of the copper oxide slurry was set to 30°C.
Set to ~80°C. This is because below 30°C, the reaction rate is slow and the resulting powder becomes more agglomerated;
This is because when the temperature exceeds .degree. C., the reaction is intense and the particle size distribution of the obtained copper powder becomes wide and at the same time the particles become coarse. Copper Powder Post-Treatment The copper powder reduced and precipitated in the present invention is subjected to solid-liquid separation by normal natural gravity filtration or deceleration filtration and water washing, and then subjected to post-treatment as required. In this invention, the following embodiment can be mentioned as a preferable post-treatment, and after this treatment, copper powder in a dispersed state is obtained. (a) Treat copper powder with alcohol. (b) Copper powder is sequentially treated with glue, water, and alcohol. (c) Treat copper powder with alcohol and fatty acids. (d) Copper powder is sequentially treated with glue, water, alcohol, and fatty acid. The alcohol used in this post-treatment is used to replace and remove moisture adhering to the surface of the copper powder, and the type of alcohol is not limited as long as it does not contradict the purpose. Preferred alcohols in this invention include methanol and ethanol. Glue used in this post-treatment is used to suppress agglomeration of the copper powder and increase the density of the powder. In this operation, the concentration of the glue aqueous solution is, for example, 0.5 to 1.0 g, and the amount added is, for example, 0.1 to 0.5% by weight based on the weight of the copper powder. In this post-treatment, after water is removed with alcohol, a fatty acid can be added to the fine copper powder as needed to impart oxidation resistance to the copper powder. The fatty acids used in this operation include stearic acid, oleic acid, linoleic acid, etc., preferably oleic acid, which is added as an alcohol solution with a concentration of 0.1 to 0.5% by volume to the fine copper powder in an amount of 0.005 to 0.2% by weight. It is believed that fatty acids not only simply adsorb to the surface, but also form a protective film, such as copper oleate, to provide oxidation resistance. The copper fine powder obtained in this way is dried to a diameter of 3 μm or less by ordinary drying method at a temperature of 60 to 90 °C without using special drying methods such as vacuum drying or freeze drying. It can be made into high purity copper fine powder. [Operations and Effects of the Invention] The following operations and effects can be obtained by the production method of the present invention. (a) By the production method of the present invention, fine copper powder having an appropriate particle size of about 3 μm or less and a narrow particle size distribution width can be obtained. This is because, although the reaction mechanism is not necessarily clear, the reactions at each stage of the production method of this invention are carried out in a solution or slurry, and the reaction to form copper powder is not carried out directly in one step. This is thought to be because it is carried out in multiple stages. (b) By controlling the powder physical properties of the intermediate product at each stage of the method of this invention, the physical properties of the final fine copper powder can be controlled, which is not necessary in the conventional method (Japanese Patent Application Laid-Open No. 116303/1983). It is not necessary to control the physical properties of the powder by adding a processing agent such as an anti-agglomeration agent from the beginning of the reaction, and furthermore, the processing agent does not affect subsequent steps. (c) After the fine copper powder is finally produced, post-treatments such as anti-oxidation treatment can be carried out, so by controlling these post-treatments it is possible to produce copper powder suitable for a wide variety of uses. That is, if the post-treatment of the present invention is unnecessary or has an adverse effect on uses other than the main use of the copper powder of the present invention for thick film conductive paste, the post-treatment of the present invention may be omitted and no glue or fatty acid may be attached. For example, it is possible to maintain an inert gas atmosphere to prevent oxidation and then use the product for the next purpose.This kind of versatility cannot be achieved with conventional techniques in which a processing agent is present from the beginning of the invention. (d) In the production method of this invention, all raw materials are easily available and easy to handle, all reaction conditions are mild, and since the reaction is carried out in a slurry or solution, this can be carried out with simple equipment. A manufacturing method can be carried out. As described above, the present invention has the effect that copper fine powder with a diameter of 3 microns or less, which has been difficult to produce in the past, can be produced in large quantities at a high yield using simple equipment. Furthermore, it has the characteristics of being a high-purity fine powder with a narrow particle size distribution, good dispersibility, low specific surface area, high tap, and oxidation resistance, all of which are necessary as paste materials for electronic components. [Example] Hereinafter, this description will be explained in more detail based on an example. However, this example is for understanding the invention and is not intended to limit the scope of the invention to this example. Example 1 Dissolve 80 kg of copper sulfate in water, add ammonia water while maintaining the temperature at 40°C, and adjust the pH of the aqueous solution to 4.0.
After preparing the copper hydroxide slurry, add water to make the total liquid volume 160 liters. Next, while maintaining the temperature at 50°C and pH 4.0, 6.01 kg of water holding ratio (1.5 times the theoretical amount) is added and reacted for 60 minutes to produce a copper oxide slurry. 60 minutes after the reaction
Leave to stand for a minute, remove the supernatant, and add water to make a total volume of 160 liters. Next, while maintaining the temperature at 50℃, hydrazine hydrate was added.
Add 8.01Kg (twice the theoretical amount) and react for 60 minutes. This reduces the copper oxide and turns it into metallic copper powder. Next, this was filtered using a natural gravity filter, washed with water, and filtered through 40 liters of a glue solution with a glue concentration of 0.5 g/water (washed filtration with water, methanol 18
After performing liquid filtration in a liter bottle and liquid filtration in 9 liters of a methanol solution with an oleic acid concentration of 0.2% by volume), it was dried in a normal atmosphere at a temperature of 80°C to obtain 20 kg of fine copper powder. The yield was 98%. The obtained fine copper powder has good dispersibility, a small particle size distribution width, a particle size of 1.25 microns (maximum particle size of 2 microns or less), a specific surface area of 0.73 m 2 /gr, and a tap density.
It was a high-purity fine copper powder containing almost no impurities, with an oxygen content of 3.68 g/cc and an oxygen content of 0.26%. After this powder was left in the atmosphere for 4 months, almost no change was observed in the oxygen quality, indicating that the powder had excellent oxidation resistance. In addition, this powder is kneaded with glass frit, an organic binder, and an organic solvent to form a copper paste, which is then screen printed on an alumina substrate and fired in a nitrogen atmosphere.It has excellent solderability, adhesive strength, and electrical conductivity. It showed little change over time and satisfactorily satisfies the characteristics of a thick film circuit. In this example, the physical properties of the copper powder produced by removing the supernatant liquid of the copper oxide slurry, adding fresh water, and repeating the process were measured, and the following results were obtained. It is clear that various physical properties can be controlled by this method.
【表】
実施例 ２
硫酸銅80Kgを水212リツトルに溶解し、温度40
℃に保持しながらアンモニア水31リツトルを添加
し、水溶液のPHを6.5に調整し銅水酸化物スラリ
ーを形成後、水を添加し全液量を320リツトルと
する。
次いで温度40℃、PH4.0を保持しながら抱水ヒ
ドラジン6.01Kgを添加し、60分間反応させ酸化銅
スラリーを生成させる。反応終了後60分間静置
し、上澄液を除去し水を添加し全液量を320リツ
トルとする。
次に温度50℃を保持しながら抱水ヒドラジン
8.01Kgを添加し、60分間反応させる。これにより
金属銅微粉末が還元析出する。
次いで実施例１と同じ処理を行つて銅微粉末
19.8Kgを得た。この収率は97％である。
得られた銅粉末は分散性良好な粒径0.36ミクロ
ン（最大粒子径0.6ミクロン以下）、比表面積1.80
m2／gr、タツプ密度3.28g／c.c.、酸素品位0.43％
の不純物を殆ど含まない高純度銅微粉末であつ
た。
また、この粉末も実施例１で得られた粉末と同
様に優れた耐酸化性を有し、厚膜回路として十分
な特性を示すものであつた。
比較例 １
アラビアゴム2gを3000c.c.の水に溶解した25℃
の溶液を撹拌しながら酸化第二銅125gを添加し
分散懸濁させた。
次いで25℃の80％抱水ヒドラジン水溶液360c.c.
を撹拌しながら添加し、３時間で60℃まで昇温
し、60℃で２時間保持した。その後室温まで冷却
し、濾過、水洗浄、アルコール洗浄後、40℃で乾
燥した。
得られた粉末は平均粒径1.2ミクロン、比表面
積0.55m2／c.c.、酸素品位4.46％の粒度分布幅の広
いものであつた。
また、この粉末は耐酸化安定性に劣り、大気中
１ケ月放置で殆んど酸化し凝集塊となつた。
比較例 ２
アラビアゴム2gを3000c.c.の水に溶解した35℃
の溶液を撹拌しながら酸化第一銅110gを添加し
分散懸濁させた。
次いで35℃の80％抱水ヒドラジン水溶液160c.c.
を撹拌しながら添加し、３時間で60℃まで昇温
し、60℃で２時間保持した。その後室温まで冷却
し、濾過、水洗浄、アルコール洗浄後、40℃で乾
燥した。
得られた粉末は平均粒径0.18ミクロン、比表面
積3.83m2／c.c.、酸素品位3.97％の粒度分布幅の広
いものであつた。また、この粉末も比較例１と同
様に耐酸化安定性に劣るものであつた。
比較例 ３
炭酸銅100gを水2000c.c.に溶解し、80％抱水ヒ
ドラジン水溶液300c.c.を撹拌しながら添加し、100
℃で８時間反応させた。その後室温まで冷却し、
濾過、水洗浄、アルコール洗浄処理して40℃で乾
燥した。
得られた粉末は平均粒径0.4ミクロン、比表面
積1.67m2／gr、酸素品位1.94％の凝集の激しい、
箔の混入したものであつた。
比較例 ４（一段還元法）
硫酸銅80Kgを水に溶解し、温度40℃に保持しな
がらアンモニア水を添加し、水溶液のPHを4.0に
調整し銅水酸化物スラリーを形成後、水を添加し
全液量を160リツトルとする。次いで温度50℃、
PHを4.0に保持しながら抱水ヒドラジン15Kg（理
論量の3.74倍）を添加し、90分間反応させ、反応
終了後、実施例１と同様に処理して、銅粉末20.5
Kgを得た。
得られた銅粉末は崇高で分散性に乏しく、比表
面積3.8m2／ｇ、タツプ密度2.5g／c.c.であり、こ
のものを実施例１と同様にペースト化したが吸油
量が大きくペースト化困難であると同時に、スク
リーン印刷性も不良であつた。
次に前記実施例１、実施例２と比較例４で得ら
れた銅粉末の粒度分布を測定した結果を順に表
１、表２と表３に示す。またこの結果をグラフで
示せば順に第１図、第２図と第３図のとおりであ
る。
これによれば、実施例１，２のとおり本発明の
二段還元反応により得られる銅粉末の粒度分布幅
は小さく、シヤープであり分散性に優れている
が、比較例４のように一段還元反応によりえられ
た銅粉末では凝集が激しく分散性に劣り粒度分布
幅の広いものになつていることが明らかである。[Table] Example 2 80 kg of copper sulfate was dissolved in 212 liters of water, and the temperature was 40 liters.
While maintaining the temperature at °C, add 31 liters of ammonia water and adjust the pH of the aqueous solution to 6.5 to form a copper hydroxide slurry, then add water to bring the total volume to 320 liters. Next, 6.01 kg of hydrazine hydrate is added while maintaining the temperature at 40°C and pH 4.0, and the reaction is allowed to proceed for 60 minutes to produce a copper oxide slurry. After the reaction is complete, let stand for 60 minutes, remove the supernatant, and add water to make a total volume of 320 liters. Next, while maintaining the temperature at 50℃, hydrazine hydrate was added.
Add 8.01Kg and react for 60 minutes. As a result, metallic copper fine powder is reduced and precipitated. Next, the same treatment as in Example 1 was performed to obtain fine copper powder.
Obtained 19.8Kg. This yield is 97%. The obtained copper powder has a particle size of 0.36 microns (maximum particle size of 0.6 microns or less) with good dispersibility, and a specific surface area of 1.80.
m2 /gr, tap density 3.28g/cc, oxygen grade 0.43%
It was a high purity fine copper powder containing almost no impurities. In addition, this powder also had excellent oxidation resistance like the powder obtained in Example 1, and exhibited sufficient characteristics as a thick film circuit. Comparative Example 1 2g of gum arabic dissolved in 3000c.c. of water at 25℃
While stirring the solution, 125 g of cupric oxide was added and dispersed and suspended. Next, add 360 c.c. of 80% hydrazine hydrate aqueous solution at 25°C.
was added with stirring, the temperature was raised to 60°C over 3 hours, and maintained at 60°C for 2 hours. Thereafter, it was cooled to room temperature, filtered, washed with water and alcohol, and then dried at 40°C. The obtained powder had a wide particle size distribution with an average particle diameter of 1.2 microns, a specific surface area of 0.55 m 2 /cc, and an oxygen content of 4.46%. In addition, this powder had poor oxidation resistance, and most of the powder was oxidized and turned into agglomerates after being left in the atmosphere for one month. Comparative Example 2 2g of gum arabic dissolved in 3000c.c. water at 35℃
While stirring the solution, 110 g of cuprous oxide was added and dispersed and suspended. Next, add 160 c.c. of 80% hydrazine hydrate aqueous solution at 35°C.
was added with stirring, the temperature was raised to 60°C over 3 hours, and maintained at 60°C for 2 hours. Thereafter, it was cooled to room temperature, filtered, washed with water and alcohol, and then dried at 40°C. The obtained powder had a wide particle size distribution with an average particle diameter of 0.18 microns, a specific surface area of 3.83 m 2 /cc, and an oxygen content of 3.97%. Further, like Comparative Example 1, this powder also had poor oxidation stability. Comparative Example 3 100 g of copper carbonate was dissolved in 2000 c.c. of water, and 300 c.c. of 80% hydrazine hydrate was added with stirring.
The reaction was carried out at ℃ for 8 hours. Then cool to room temperature,
It was filtered, washed with water, washed with alcohol, and dried at 40°C. The obtained powder has an average particle size of 0.4 microns, a specific surface area of 1.67 m 2 /gr, and a highly agglomerated powder with an oxygen content of 1.94%.
It was contaminated with foil. Comparative example 4 (one-step reduction method) Dissolve 80 kg of copper sulfate in water, add ammonia water while maintaining the temperature at 40°C, adjust the pH of the aqueous solution to 4.0, form a copper hydroxide slurry, and then add water. Make the total liquid volume 160 liters. Then the temperature is 50℃,
While maintaining the pH at 4.0, 15 kg of hydrazine hydrate (3.74 times the theoretical amount) was added and reacted for 90 minutes. After the reaction was completed, the same procedure as in Example 1 was carried out to obtain 20.5 kg of copper powder.
Got Kg. The obtained copper powder was sublime and had poor dispersibility, with a specific surface area of 3.8 m 2 /g and a tap density of 2.5 g/cc. This powder was made into a paste in the same manner as in Example 1, but the large oil absorption made it difficult to make a paste. At the same time, the screen printability was also poor. Next, the results of measuring the particle size distribution of the copper powders obtained in Example 1, Example 2, and Comparative Example 4 are shown in Table 1, Table 2, and Table 3 in order. The results are shown in graphs as shown in FIGS. 1, 2, and 3 in order. According to this, as in Examples 1 and 2, the particle size distribution width of the copper powder obtained by the two-stage reduction reaction of the present invention is small and sharp, and it has excellent dispersibility, but as in Comparative Example 4, It is clear that the copper powder obtained by the reaction is highly agglomerated, has poor dispersibility, and has a wide particle size distribution.
【表】【table】
【表】【table】
【表】【table】
【表】
叙上の実施例に明らかなごとく、本発明による
銅微粉末の製造法は従来の方法によつて得られる
銅粉末よりその特性において優れ、かつ簡便な設
備を用いて大量に高収率で製造しうるもので甚だ
有用な発明である。[Table] As is clear from the examples described above, the method for producing fine copper powder according to the present invention has superior properties to copper powder obtained by conventional methods, and can be produced in large quantities at high yields using simple equipment. It is an extremely useful invention that can be manufactured at a low rate.
第１図、第２図と第３図は順に明細書の実施例
１、実施例２と比較例４によりえられた銅粉末の
粒度分布を示すグラフである。
FIG. 1, FIG. 2, and FIG. 3 are graphs showing particle size distributions of copper powders obtained in Example 1, Example 2, and Comparative Example 4 of the specification.
Claims (1)
７に、液温を20〜60℃に維持しながら、反応させ
てえられた反応混合物からなる水酸化銅スラリー
に、そのスラリーのPHを３〜６に、温度を30〜90
℃に維持しながら、ヒドラジンおよび／またはヒ
ドラジン化合物を、酸化銅を生成するに必要な理
論量の１〜３倍量添加して酸化銅スラリーをつく
り、静置後このスラリーの上澄液を除去し、新た
に水を添加し、更にそのスラリーの温度を30〜80
℃に維持しながら、ヒドラジンおよび／またはヒ
ドラジン化合物を、酸化銅を金属銅に還元するに
必要な理論量の１〜３倍量添加して銅粉末に還元
析出させることを特徴とする銅粉末の製造法。1 Copper ion-containing aqueous solution and alkali, pH 3~
Step 7: While maintaining the liquid temperature at 20 to 60°C, add the slurry to a copper hydroxide slurry consisting of the reaction mixture, with the pH of the slurry at 3 to 6, and the temperature at 30 to 90.
While maintaining the temperature at °C, add hydrazine and/or hydrazine compound in an amount of 1 to 3 times the theoretical amount required to generate copper oxide to create a copper oxide slurry, and after standing still, remove the supernatant liquid of this slurry. Then, add new water and further increase the temperature of the slurry to 30-80℃.
While maintaining the temperature at ℃, hydrazine and/or a hydrazine compound is added in an amount of 1 to 3 times the theoretical amount required to reduce copper oxide to metallic copper, and the copper powder is reduced and precipitated. Manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24087585A JPS6299406A (en) | 1985-10-28 | 1985-10-28 | Production of copper powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24087585A JPS6299406A (en) | 1985-10-28 | 1985-10-28 | Production of copper powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6299406A JPS6299406A (en) | 1987-05-08 |
| JPH0557324B2 true JPH0557324B2 (en) | 1993-08-23 |
Family
ID=17065993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24087585A Granted JPS6299406A (en) | 1985-10-28 | 1985-10-28 | Production of copper powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6299406A (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2638271B2 (en) * | 1990-09-06 | 1997-08-06 | 住友金属工業株式会社 | Production method of copper fine powder |
| US6620344B2 (en) | 1999-05-28 | 2003-09-16 | Dowa Mining Co., Ltd. | Copper particle clusters and powder containing the same suitable as conductive filler of conductive paste |
| KR100743844B1 (en) | 1999-12-01 | 2007-08-02 | 도와 마이닝 가부시끼가이샤 | Copper powder and process for producing copper powder |
| US6881240B2 (en) | 2000-09-18 | 2005-04-19 | Dowa Mining Co., Ltd. | Copper powder for electrically conductive paste |
| KR100405970B1 (en) * | 2001-09-18 | 2003-11-14 | 한국과학기술연구원 | Synthesis of Cu Fine Particles by Glycothermal Process |
| KR100486604B1 (en) * | 2002-10-30 | 2005-05-03 | (주)창성 | Method for manufacturing nano-scale copper powders by wet reducing process |
| JP5144022B2 (en) * | 2006-03-24 | 2013-02-13 | 三井金属鉱業株式会社 | Copper powder manufacturing method and copper powder obtained by the manufacturing method |
| JP5392884B2 (en) * | 2007-09-21 | 2014-01-22 | 三井金属鉱業株式会社 | Method for producing copper powder |
| WO2014080662A1 (en) | 2012-11-26 | 2014-05-30 | 三井金属鉱業株式会社 | Copper powder and method for producing same |
| JP6004034B1 (en) * | 2015-04-21 | 2016-10-05 | 住友金属鉱山株式会社 | 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 |
| CN113549948B (en) * | 2021-07-28 | 2022-12-30 | 中国科学技术大学 | Surface amino modified Cu @ NH 2 Nano catalyst, preparation method and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5896802A (en) * | 1981-12-04 | 1983-06-09 | Tadaharu Ogawa | Production of fine metallic powder by wet reduction |
| JPS58224103A (en) * | 1982-06-21 | 1983-12-26 | Mitsui Mining & Smelting Co Ltd | Production of fine copper powder |
-
1985
- 1985-10-28 JP JP24087585A patent/JPS6299406A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5896802A (en) * | 1981-12-04 | 1983-06-09 | Tadaharu Ogawa | Production of fine metallic powder by wet reduction |
| JPS58224103A (en) * | 1982-06-21 | 1983-12-26 | Mitsui Mining & Smelting Co Ltd | Production of fine copper powder |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6299406A (en) | 1987-05-08 |
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