JPS58224103A - Production of fine copper powder - Google Patents

Abstract

PURPOSE:To produce easily fine copper powder having micro grain sizes in a large amt. and high yield with a simple installation by reducing copper ions in an aq. soln. with sodium borohydride, etc. to the agglomerate of fine metallic powder then treating the same with glue or the like. CONSTITUTION:An aq. soln. of CuSO4, etc. contg. copper as ions is maintained at about 6.0-10, more preferably about 8.0-9.5pH by caustic soda, mineral acid, etc. and about 1.5-3 times, more preferably about 1.7-2.5 times of the theoretical amt. of sodium borohydride or dimethylamine borane is added to the aq. soln. to reduce the copper ions, whereby copper can be filtered out easily in a short time as the agglomerate of fine metallic powder. Glue and/or alcohol is added to the agglomerate to form the dispersion of the fine copper powder and in succession the excess glue is washed with water; thereafter, the water is substituted and removed with alcohol, and the powder is dried at about 60-90 deg.C, whereby the fine copper powder of about 0.1mum diameter which is stable in air is obtd.

Description

【発明の詳細な説明】 本発明は湿式法による銅微粉の製造方法に関し、更には
直径０．１μｍ以下の銅微粉を容易に製造し得る銅微粉
の製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION 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 that can easily produce fine copper powder having a diameter of 0.1 μm or less.

現在、直径０，１μｍ以下の銅微粉を得る製造方法とし
ては、 （１）　　銅化合物を融点以下の温度でＣｏ、Ｈ２等に
より還元するガス還元法、 （２）真空あるいは不活性ガス中で銅を蒸発、凝縮する
方法、 （３）　　プラズマジュツトあるいはアークによる電気
分散法、 等が知られている。Currently, the production methods for obtaining fine copper powder with a diameter of 0.1 μm or less include (1) gas reduction method in which copper compounds are reduced with Co, H2, etc. at a temperature below the melting point; (2) copper reduction in vacuum or inert gas; (3) Electrodispersion method using plasma jut or arc, etc. are known.

しかし、（１）の方法は使用する銅化合物の粒度、粒子
形態の影響が顕著であること及び高温であるため粒子の
焼結が生じる欠点がある。（２）の方法は、一般的に広
く超微粉を得る方法として、実施されているものである
が、温度、雰囲気の圧力などによシ蒸発速度が支配され
、製造能力は極めて低く、大量の粉末を連続して製造し
にくい欠点を有する。However, method (1) has the disadvantage that the particle size and particle morphology of the copper compound used are significantly affected and that the particles are sintered due to the high temperature. Method (2) is generally practiced as a method for obtaining ultrafine powder, but the evaporation rate is controlled by temperature, atmospheric pressure, etc., and the production capacity is extremely low. It has the disadvantage that it is difficult to continuously produce powder.

さらに（３）の°方法は高融点、低蒸気圧の金属に適し
た方法であり、生産量の点では優れているが、ジェット
噴流により溶融物質そのものを吹きとばしてしまう点及
び粒度のコントロールが困難である等の欠点を有す。Furthermore, the method (3) is suitable for metals with high melting points and low vapor pressures, and is superior in terms of production volume, but it also has the drawbacks of blowing away the molten material itself with a jet stream and the difficulty in controlling particle size. It has disadvantages such as being difficult.

まだ、従来、実施されていた化学的還元法及び電気化学
的還元法等の湿式法で得られる銅粉の殆んどは直径０．
５μｍ以上の粒径の一定しない粒末であり、さらに微粉
とするだめには不活性ガス雰囲気中での微粉砕を必要と
し、得られる粉末の直径も０．１　ｐｍ以下にはならず
、収率も低かった。Still, most of the copper powders obtained by conventional wet methods such as chemical reduction methods and electrochemical reduction methods have a diameter of 0.
The powder has an irregular particle size of 5 μm or more, and requires pulverization in an inert gas atmosphere to make it into a fine powder. The rate was also low.

寸だ、一般的に湿式法で得られる微粉は粒径が小さくな
る？１と、一般的濾過では回収困難であり、空気中です
ぐ酸化してしまい取扱い上多くの問題があると言った欠
点を有していた。In general, fine powder obtained by wet method has a smaller particle size? 1, it is difficult to recover by general filtration, and it oxidizes easily in the air, causing many problems in handling.

本発明は、これらの欠点を解消すべくなされたもので、
その目的は湿式法により、簡便な設備で容易に直径０．
１μｍ以下に粒度をコントロールし、かつ大量に高収率
で製造し得る銅微粉の製造法を提供することにある。The present invention was made to eliminate these drawbacks, and
The purpose is to use a wet method to easily achieve a diameter of 0.00 mm using simple equipment.
The object of the present invention is to provide a method for producing fine copper powder, which can control the particle size to 1 μm or less and can be produced in large quantities at a high yield.

本発明者らは、前記目的を達成すべく種々研究を重ねた
結果、銅をイオンとして含有するＣｕＳＯ４ｐＣｕ（Ｎ
ｏ３）２．　Ｃｕｃ１２　、　　（Ｃｕ（ＮＨ３）４］
ＳＯ４、ＣＣｕ（ＮＨ３）４　）（ＮＯ３）２１．［Ｃ
ｕ（ＮＨ３）４　〕（！Ｌ等の水溶液に水素化ホウ素ナ
トリウム（以下、ＳＢＨと記す）またはジメチルアミン
ボラン（以下ＤＭＡ　Ｂ　と記す）を添加し、銅を金属
微粉凝集体に還元した後、該金属微４　　　　粉凝集体
１及び／ｊ＊″７／ｕ’ｊ−／Ｌ＝ｆ処１−ｔ−、ｂこ
とにより、空気中で安定な直径０．１μｍ以下の銅微粉
を得ることを見出し本発明を完成した。As a result of various studies to achieve the above object, the present inventors discovered that CuSO4pCu (N
o3)2. Cuc12, (Cu(NH3)4]
SO4, CCu(NH3)4 )(NO3)21. [C
After adding sodium borohydride (hereinafter referred to as SBH) or dimethylamine borane (hereinafter referred to as DMAB) to an aqueous solution of u(NH3)4](!L etc.) and reducing copper to fine metal powder aggregates, The metal fine 4 powder aggregate 1 and /j*''7/u'j-/L=f treatment 1-t-,b can be used to obtain fine copper powder with a diameter of 0.1 μm or less that is stable in the air. Heading The invention has been completed.

すなわち本発明は、銅をイオンとして含有する水溶液に
水素化ホウ素ナトリウムまたはジメチルアミンポランを
添加し、銅を金属微粉凝集体に還元した後、膠及び／ま
たはアルコールで処理することにより金属微粉分散体を
得ることを特徴とする銅微粉の製造法にある。That is, the present invention adds sodium borohydride or dimethylamine poran to an aqueous solution containing copper as ions, reduces the copper to metal fine powder aggregates, and then treats it with glue and/or alcohol to form a metal fine powder dispersion. A method for producing fine copper powder is provided.

本発明においては、銅をイオンとして含有する水溶液の
ＰＨを苛性ソーダ、苛性カリ、アンモニア等、好壕しく
けアンモニア及び鉱酸により６．０〜１０好ましくは８
．０〜９．５に保ち、水溶液中の銅を金属に還元するに
必要な理論量の１．５〜３倍、好ましくは１゜７〜２，
５倍量のＳＢＨまだはＤＭＡ　Ｂを添加する。この操作
により、水溶液中の銅イオンは金属微粉凝集体となり、
濾過助剤または凝集剤を使用することなく、自然重力濾
過、減圧濾過により簡単に短時間で固液分離できる。固
液分離され、沖過器に保持された上記銅微粉凝集体に膠
及び／またはアルコール、好ましくは膠及びアルコール
を添加、通液し、銅微粉分散体とする。こ　　１の操作
において、使用する膠は濃度０．５〜５ｇ／ｌの水溶液
として添加する。続いて、水により過剰の膠を洗浄後、
アルコール添加により水を置換除去する。この様にして
得られた、銅微粉分散体は、不活性ガス雰囲気を使用す
ることなく、通常の雰囲気で６０〜９０℃、６０〜６０
分乾燥することにより空気中で取扱い可能な安定な直径
０．１μｍ以下の銅微粉とすることが出来る。In the present invention, the pH of the aqueous solution containing copper as ions is adjusted to 6.0 to 10, preferably 8 by using aqueous ammonia and mineral acids such as caustic soda, caustic potash, ammonia, etc.
．． 0 to 9.5, and 1.5 to 3 times the theoretical amount required to reduce copper in an aqueous solution to metal, preferably 1.7 to 2.
Add 5 times the amount of SBH or DMA B. Through this operation, the copper ions in the aqueous solution become metal fine powder aggregates,
Solid-liquid separation can be easily performed in a short time by natural gravity filtration or vacuum filtration without using filter aids or flocculants. Glue and/or alcohol, preferably glue and alcohol, are added to the copper fine powder aggregates separated from solid and liquid and held in an offshore filter, and the liquid is passed therethrough to obtain a copper fine powder dispersion. In this first operation, the glue used is added as an aqueous solution with a concentration of 0.5 to 5 g/l. Next, after washing excess glue with water,
Water is removed by displacement by addition of alcohol. The copper fine powder dispersion obtained in this way can be heated at 60-90°C and 60-60°C in a normal atmosphere without using an inert gas atmosphere.
By drying for 30 minutes, it is possible to obtain stable copper fine powder with a diameter of 0.1 μm or less that can be handled in the air.

以上のごとき本発明によると、従来困難とされていた湿
式法により、乾式法に比較して、簡便な設備で容易に直
径０．１μｍ以下の銅微粉を大量に高収率で製造できる
という優れた効果を有し、さらに得られた銅微粉は粒径
の揃った、比表面積１０〜３０ｒｔ？／ｇ、直径０．１
μｍ以下の微粉であり、大気中１４０℃まで酸化せず安
定であるといった優れた特性も有している。According to the present invention, copper fine powder with a diameter of 0.1 μm or less can be easily produced in large quantities and at a high yield with simple equipment compared to the dry method using a wet method, which has been considered difficult in the past. In addition, the obtained fine copper powder has a uniform particle size and a specific surface area of 10 to 30 rt? /g, diameter 0.1
It is a fine powder of micrometers or less, and has excellent properties such as being stable without oxidation up to 140°C in the atmosphere.

以下、本発明を実施例および比較例に基づいてさらに具
体的に説明するが、本発明はこれによって限定されるも
のではない。EXAMPLES Hereinafter, the present invention will be explained in more detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

実施例１〜３ 硫酸銅（ＣｕＳＯ４・５Ｈ２０）を水に溶解後、アンモ
ニア水（ＮＨ４０Ｈ）及び硫酸（Ｈ，５ｏ４）により、
ＰＨを種々に調幣したＣｕ濃度０．５ｍｏｌ／、の水溶
液各５０００＄　　　　　　　に、銅を金属銅に還元す
るに必要な理論量の２倍のＳＢＨを水に溶解し、反応Ｐ
Ｈおよび温度を２０℃に保持しながら添加し、銅を金属
微粉凝集体に還元した後、該金属微粉凝集体含有スラリ
ーを自然重力濾過し、ｐ過器に保油液洗浄濾過、メタノ
ール２００ｃｃを通液濾過の各処理をした後、通常雰囲
気下にて８０℃、６０分乾燥した。。Examples 1 to 3 After dissolving copper sulfate (CuSO4.5H20) in water, with aqueous ammonia (NH40H) and sulfuric acid (H, 5o4),
Twice the theoretical amount of SBH required to reduce copper to metallic copper was dissolved in water to each 5,000 $ aqueous solution with a Cu concentration of 0.5 mol/, with various pH levels, and the reaction P
After adding H and maintaining the temperature at 20°C to reduce copper to metal fine powder aggregates, the metal fine powder aggregate-containing slurry was filtered by gravity, and an oil retaining liquid was washed and filtered in a p filter, and 200 cc of methanol was added. After carrying out each process of liquid filtration, it was dried at 80° C. for 60 minutes in a normal atmosphere. .

反応ＰＨ１銅収率、生成銅微粉物性を第１表に示また、
実施例２の生成銅微粉の走査電子顕微鏡写真（ｘｌｏｏ
ｏｏ、ｘ２００００　）を第１図囚および第１図（Ｂ’
）に示す。第１図（Ａ）および第１図（Ｂ）から実施例
２においては直径０．１μｍ以下の粒径の揃った微粉が
得られることがわかる。The reaction PH1 copper yield and the physical properties of the produced copper fine powder are shown in Table 1.
Scanning electron micrograph of fine copper powder produced in Example 2 (xloo
oo, x20000) in Figure 1 and Figure 1 (B'
). It can be seen from FIG. 1(A) and FIG. 1(B) that in Example 2, fine powder with a uniform particle size of 0.1 μm or less in diameter was obtained.

実施例４〜８ 実施例１と同様な方法で調製したＣｕ濃度０．５””／
ｌ、Ｐ”−０ノ水溶’ｔｊ−各５００ｃｃ　ニＳ　Ｂ　
Ｈヲ水に溶解したＳＢＨ溶液を添加量を変えて添加し、
液温を２０℃にて反応させ、生成した銅微粉凝集体を実
施例１と同様な方法で処理した。Examples 4 to 8 Cu concentration 0.5''/ prepared in the same manner as Example 1
l, P''-0 water soluble'tj-500cc each SB
SBH solution dissolved in water was added in varying amounts,
The reaction was carried out at a liquid temperature of 20° C., and the produced fine copper powder aggregates were treated in the same manner as in Example 1.

ＳＢＨ添加量、銅収率、生成銅微粉物性を第２実施例９
〜１２および比較例１〜２ 実施例１と同様な方法で調整しだＣｕ濃度０．５ｍｏｌ
／ｌ、　ｐＨ９，０の水溶液者５００ｃｃに銅を金属銅
に還元するに必要な理論量の２倍の各種還元剤を水溶液
で添加［７、生成した銅微粉凝集体を実施例１と同様な
方法で処理した。The amount of SBH added, copper yield, and physical properties of the produced copper fine powder were measured in Example 9.
-12 and Comparative Examples 1-2 Cu concentration 0.5 mol adjusted in the same manner as in Example 1
/l, to 500 cc of an aqueous solution at pH 9.0, was added an aqueous solution of various reducing agents in an amount twice the theoretical amount required to reduce copper to metallic copper [7. processed by the method.

反応条件、銅収率、生成銅微粉物性を第６表に特開昭５
８−２２４１０３（４） 供用Ｃｕ原料を変えこれを水に分散または溶解した後、
アンモニア水及び硫酸で−９，０に調整した。ｕ＃度０
．５　ｍ”／ｌの水溶液に銅を金属鋼に還元するに必要
な理論量の２倍のＳＢＨ水溶液を添加し、生成した銅微
粉凝集体を実施例１と同じ方法で処理した。The reaction conditions, copper yield, and physical properties of the produced copper fine powder are shown in Table 6.
8-224103 (4) After changing the Cu raw material used and dispersing or dissolving it in water,
It was adjusted to -9.0 with aqueous ammonia and sulfuric acid. u # degree 0
．． Twice the theoretical amount of SBH aqueous solution required to reduce copper to metal steel was added to the 5 m''/l aqueous solution, and the resulting copper fine powder aggregates were treated in the same manner as in Example 1.

供用Ｃｕ原料、銅酸率、生成銅微粉物性を第４表実施例
１６〜１９および比較例６ 実施例１と同じ方法で反応−１９０、反応温度２０℃と
して生成した銅微粉凝集体を処理方法を様々変えて処理
した。Table 4 shows the Cu raw materials used, the copper acid ratio, and the physical properties of the produced copper fine powder. were processed in various ways.

処理方法、生成銅微粉物性を第５表に示す。Table 5 shows the treatment method and the physical properties of the copper fine powder produced.

【図面の簡単な説明】[Brief explanation of drawings]

第１図（Ａ）および第１図（Ｂ）は各々実施例２により
得られた銅微粉の１００００倍および２００００倍の走
査電子顕微鏡写真である。 特許出願人　　　　三井金属鉱業株式会社代理人　　弁
理士伊東辰雄 〃　伊東哲也FIG. 1(A) and FIG. 1(B) are scanning electron micrographs of the copper fine powder obtained in Example 2, magnified 10,000 times and 20,000 times, respectively. Patent applicant Mitsui Kinzoku Mining Co., Ltd. Agent Patent attorney Tatsuo Ito Tetsuya Ito

Claims (1)

【特許請求の範囲】[Claims] 銅をイオンとして含有する水溶液に水素化ホウ素ナトリ
ウムまたはジメチルアミンボランを添加し、銅を金属微
粉凝集体に還元した後、膠及び／まだはアルコールで処
理することにより金属微粉分散体を得ることを特徴とす
る銅微粉の製造法。A fine metal powder dispersion is obtained by adding sodium borohydride or dimethylamine borane to an aqueous solution containing copper as ions, reducing the copper to fine metal powder aggregates, and then treating with glue and/or alcohol. Characteristic manufacturing method of copper fine powder.