JPH09125110A - Production of electrolytic silver powder - Google Patents
Production of electrolytic silver powderInfo
- Publication number
- JPH09125110A JPH09125110A JP28827495A JP28827495A JPH09125110A JP H09125110 A JPH09125110 A JP H09125110A JP 28827495 A JP28827495 A JP 28827495A JP 28827495 A JP28827495 A JP 28827495A JP H09125110 A JPH09125110 A JP H09125110A
- Authority
- JP
- Japan
- Prior art keywords
- silver powder
- powder
- electrolytic silver
- electrolytic
- silver
- 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.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、主に焼結材料として、
モーターの電刷子に使用する電解銀粉末の製造方法に関
するものである。通常、電解銀粉末は黒鉛粉末と混合
し、金属黒鉛刷子となる。銀粉末を混入すると刷子の性
能変化が少ないので、低電圧で使う電子機器用として、
よく使用されている。BACKGROUND OF THE INVENTION The present invention is mainly used as a sintered material.
The present invention relates to a method for producing electrolytic silver powder used in electric brushes for motors. Usually, electrolytic silver powder is mixed with graphite powder to form a metal graphite brush. When silver powder is mixed in, there is little change in brush performance, so for electronic equipment used at low voltage,
It is often used.
【０００２】[0002]
【従来の技術】電解銀粉末を含む金属黒鉛刷子の製造方
法は以下〜の工程で行う。 電解銀粉末と黒鉛粉末を混合する。配合率は目的とす
る刷子の特性によって変えるが、銀含有量４０〜８０重
量パーセント、黒鉛含有量６０〜２０重量パーセントが
一般的である。 これを型に入れて圧縮する。圧力は１００〜２００Ｍ
Ｐａである。 圧縮した成形体を焼結炉に入れ、分解NH3 等の雰囲気
中、５００〜１０００℃で行う。 焼結後再加圧して寸法を決めるが、その前後に機械加
工するものもある。従来の電解銀粉末は経時変化で、粉
同志が短期間に凝集するため上記の混合工程で多くの
問題が生じていた。それは電解銀粉末が樹枝状の形状の
ため粉末同志がからみやすく、また金属組成的にも銀は
粒成長して凝集する傾向が強い。これらの理由から製造
３日後には電解銀粉末の一次粒子の凝集が認められ、１
ヶ月後には電解銀粉末を機械的に再分散しなければ数ミ
リの粗大凝集物も生じるため金属黒鉛刷子の原材料とし
て使用できないものとなっていた。2. Description of the Related Art A method for producing a metal graphite brush containing electrolytic silver powder is performed in the following steps. Electrolytic silver powder and graphite powder are mixed. The blending ratio varies depending on the characteristics of the target brush, but a silver content of 40 to 80 weight percent and a graphite content of 60 to 20 weight percent are common. This is put into a mold and compressed. Pressure is 100-200M
Pa. The compressed molded body is put into a sintering furnace and performed at 500 to 1000 ° C. in an atmosphere of decomposed NH 3 or the like. The size is determined by re-pressurizing after sintering, but some are machined before and after that. The conventional electrolytic silver powder has changed over time, and many particles have agglomerated in a short period of time, causing many problems in the above mixing process. Because the electrolytic silver powder has a dendritic shape, the powders are easily entangled with each other, and the metal composition has a strong tendency for silver particles to grow and aggregate. For these reasons, agglomeration of primary particles of electrolytic silver powder was observed after 3 days of production.
After a few months, if the electrolytic silver powder was not mechanically redispersed, coarse aggregates of several millimeters were also formed, and it could not be used as a raw material for a metal graphite brush.
【０００３】電解銀粉末の凝集を機械的に再分散するこ
とは可能であるが、銀粉末は軟らかい金属であり、樹枝
状形状が丸状になり金属黒鉛刷子としてよくない。銀粉
末の凝集防止方法としては片状粉末でよく行われる脂肪
酸被覆が有るが、この方法は金属黒鉛刷子の特性（比電
気抵抗）や、圧縮成形性や、寸法精度を悪くするため良
くない。このため、経時変化によって凝集する問題を有
するものの、無処理の電解銀粉末が現在も使用されてい
る。Although it is possible to mechanically redisperse the agglomeration of the electrolytic silver powder, the silver powder is a soft metal and its dendritic shape becomes round, which is not good for a metal graphite brush. As a method for preventing the aggregation of silver powder, there is a fatty acid coating which is often performed with flaky powder, but this method is not preferable because it deteriorates the characteristics (specific electric resistance) of the metal graphite brush, compression moldability, and dimensional accuracy. Therefore, unprocessed electrolytic silver powder is still used, although it has a problem of aggregation due to aging.
【０００４】[0004]
【発明が解決しようとする課題】電解銀粉末を製造して
から、電刷子として使用するまでの間、凝集しない粉末
であって、しかも電刷子特性を悪くしない電解銀粉末が
望まれていた。It has been desired to develop an electrolytic silver powder which does not agglomerate from the production of the electrolytic silver powder to its use as an electric brush and does not deteriorate the characteristics of the electric brush.
【０００５】[0005]
【課題を解決するための手段】即ち本発明は、電解銀粉
末を高級脂肪族アミンの有機酸塩を含む水溶液に浸漬
し、しかる後に脱水乾燥することを特徴とする電解銀粉
末の製造方法である。本発明の高級脂肪族アミンの有機
酸塩とは、炭素原子数１２〜２２の脂肪族炭化水素を有
する脂肪族モノアミン又はジアミンと、炭素原子数２〜
２３の脂肪族炭化水素を有するか、あるいは炭素原子数
７〜８の芳香族炭化水素基を有するモノ又はジカルボン
酸とからなる塩であり、具体的には椰子モノアミン酢酸
塩、椰子モノアミンサルチル酸塩、椰子ジアミンアジピ
ン酸塩、牛脂ジアミンサルチル酸塩などが挙げられる。That is, the present invention provides a method for producing an electrolytic silver powder, which comprises immersing the electrolytic silver powder in an aqueous solution containing an organic acid salt of a higher aliphatic amine, and then dehydrating and drying. is there. The organic acid salt of a higher aliphatic amine of the present invention includes an aliphatic monoamine or diamine having an aliphatic hydrocarbon having 12 to 22 carbon atoms and 2 to 2 carbon atoms.
A salt comprising a mono- or dicarboxylic acid having 23 aliphatic hydrocarbons or an aromatic hydrocarbon group having 7 to 8 carbon atoms, and specifically, palm monoamine acetate and palm monoamine salicylate. , Palm diamine adipate, tallow diamine salicylate and the like.
【０００６】電解銀粉末とは硝酸銀水溶液から、電気的
に陰極に樹枝状粒子の銀粉末を析出した銀粉末である。
この電解銀粉末を高級脂肪族アミンの有機酸塩を含む水
溶液に浸漬し処理するのであるが、この場合高級脂肪族
アミンの有機酸塩の水への添加量が重要となる。すなわ
ち、水溶液への高級脂肪族アミンの有機酸塩の添加量は
水に対して20ppm〜5000ppm が良い。20ppm より少ない
と表面処理の効果が少なく、凝集する可能性が有る。50
00ppmより濃度が大であると凝集の問題はなくなるが、
金属黒鉛刷子としての性能に悪い影響を与える。好まし
い量は50ppm 〜2000pppmである。The electrolytic silver powder is a silver powder obtained by electrically depositing dendritic silver powder on the cathode from an aqueous silver nitrate solution.
This electrolytic silver powder is treated by immersing it in an aqueous solution containing an organic acid salt of a higher aliphatic amine. In this case, the amount of the organic acid salt of a higher aliphatic amine added to water is important. That is, the amount of the organic acid salt of higher aliphatic amine added to the aqueous solution is preferably 20 ppm to 5000 ppm with respect to water. If it is less than 20 ppm, the effect of surface treatment is small and there is a possibility of aggregation. 50
When the concentration is higher than 00ppm, the problem of aggregation disappears,
It adversely affects the performance as a metal graphite brush. The preferred amount is 50 ppm to 2000 ppm.
【０００７】電解銀粉末を高級脂肪族アミンの有機酸塩
の水溶液に浸漬する方法は、水溶液を入れた容器に電解
銀粉末を投入し、浸漬するか、場合によってはすこし攪
拌すれば良い。しかる後に、遠心脱水機などで水溶液と
電解銀粉末を分離する。浸漬する時間は数秒で効果があ
るが均一に、表面に被覆するためには５分間程度浸漬す
るのが良い。なお、高級脂肪族アミンの有機酸塩の添加
量が500ppm以下の場合は２度同じ処理方法を行うと非常
に優れた凝集防止効果が得られる。The electrolytic silver powder may be immersed in an aqueous solution of an organic acid salt of a higher aliphatic amine by placing the electrolytic silver powder in a container containing the aqueous solution and immersing it, or in some cases, stirring it slightly. After that, the aqueous solution and the electrolytic silver powder are separated with a centrifugal dehydrator or the like. The dipping time is several seconds, which is effective, but it is preferable that the dipping is performed for about 5 minutes in order to coat the surface uniformly. When the amount of the organic acid salt of the higher aliphatic amine added is 500 ppm or less, a very excellent aggregation preventing effect can be obtained by performing the same treatment method twice.
【０００８】水溶液から分離した電解銀粉末は約 105℃
で乾燥して、水を蒸発させる。なお、乾燥を速くするた
めにアルコール等を添加することも可能である。高級脂
肪族アミンの有機酸塩を直接電解銀粉末に添加混合被覆
する方法も考えられるが、樹枝状形状の表面に均一に被
覆することが難しく、また均一に被覆するためには添加
量も多くなり良くないThe electrolytic silver powder separated from the aqueous solution is about 105 ° C.
Dry with and evaporate the water. It is also possible to add alcohol or the like to speed up the drying. A method of adding and mixing the organic acid salt of higher aliphatic amine directly to electrolytic silver powder is also conceivable, but it is difficult to uniformly coat the surface of dendritic shape, and the addition amount is large for uniform coating. Not good
【０００９】[0009]
【作用】電解銀粉末を高級脂肪族アミンの有機酸塩を含
む水溶液に浸漬し、乾燥することによって電解銀粉末表
面にどのような保護層が形成されているか定かでない
が、本発明者等は次のように考えている。高級脂肪族ア
ミンの有機酸塩を含む水溶液に電解銀粉末を浸漬する
と、非常に短時間に銀表面と化学吸着が起こり、被膜を
形成し、乾燥することにより発水性を有する保護膜とな
る。この保護膜は非常に薄く、焼結に悪影響を与えるこ
となく、また経時変化によっても、ベンゾトリアゾール
のように膜厚が成長することなく、一定の膜厚を維持す
る。このように処理した電解銀粉末を長時間大気中に放
置しても銀粉末の凝集が生じないのは、この非常に薄い
化学吸着層が銀粉末の粒成長を防止する効果を有してい
るのであろう。以下実施例及び比較例により本発明を具
体的に説明する。It is not clear what protective layer is formed on the surface of the electrolytic silver powder by immersing the electrolytic silver powder in an aqueous solution containing an organic acid salt of a higher aliphatic amine and drying it. I think as follows. When electrolytic silver powder is immersed in an aqueous solution containing an organic acid salt of a higher aliphatic amine, chemisorption occurs on the silver surface in a very short time, and a coating film is formed and dried to form a water-repellent protective film. This protective film is very thin, and does not adversely affect the sintering, and maintains a constant film thickness even if it changes with time without the film thickness growing like benzotriazole. Aggregation of the silver powder does not occur even if the electrolytic silver powder thus treated is left in the air for a long time. This very thin chemisorption layer has an effect of preventing grain growth of the silver powder. It will be. The present invention will be specifically described below with reference to Examples and Comparative Examples.
【００１０】[0010]
【実施例１】高級脂肪族アミンに有機酸塩として椰子モ
ノアミン酢酸塩を0.2cc ,0.5cc ,2cc, 5cc計量し水10ｌ
の入った容器にそれぞれ加え均一に攪拌した。このよう
に調整した椰子モノアミン酢酸塩の水溶液に電解銀粉末
（＋75μm 0%,＋45μm 2%, −45μm 98%)10Kgを投入
し、攪拌棒で時々攪拌しながら５分間浸漬した。しかる
後、遠心脱水機（200rpm）で脱水し、再び同じ椰子モノ
アミン酢酸塩の水溶液に５分間浸漬し、脱水し電解銀粉
末を水と分離した。その後 105℃の熱風乾燥器で乾燥し
た。この様にして得た電解銀粉末は全て６ヶ月後も凝集
は認められず、金属黒鉛刷子として使用できるものであ
った。Example 1 0.2 cc, 0.5 cc, 2 cc, and 5 cc of palm monoamine acetate as an organic acid salt of a higher aliphatic amine were weighed and 10 l of water was added.
Was added to each container and stirred uniformly. 10 kg of electrolytic silver powder (+75 μm 0%, +45 μm 2%, −45 μm 98%) was added to the thus-prepared aqueous solution of palm monoamine acetate, and the mixture was immersed for 5 minutes with occasional stirring with a stirring rod. After that, it was dehydrated by a centrifugal dehydrator (200 rpm), again immersed in the same aqueous solution of palm monoamine acetate for 5 minutes, dehydrated and the electrolytic silver powder was separated from water. Then, it was dried with a hot air dryer at 105 ° C. The electrolytic silver powders thus obtained did not show aggregation even after 6 months, and could be used as a metal graphite brush.
【００１１】[0011]
【実施例２】高級脂肪族アミンの有機酸塩として椰子モ
ノアミン酢酸塩を10cc,20cc,50cc計量し、水10ｌの入っ
た容器にそれぞれ加え均一に攪拌した。このように調整
した椰子モノアミン酢酸塩の水溶液に実施例１と同じ電
解銀粉末10Kgを投入し、５分間浸漬した。しかる後、遠
心脱水機（200rpm）で脱水し、電解銀粉末を水と分離
し、 105℃の熱風乾燥器で乾燥した。この様にして得た
電解銀粉末は全て６ヶ月後も凝集なく、金属黒鉛刷子と
して使用できた。EXAMPLE 2 Palm monoamine acetate as an organic acid salt of a higher aliphatic amine was weighed in an amount of 10 cc, 20 cc and 50 cc, added to a container containing 10 l of water and stirred uniformly. The same electrolytic silver powder as in Example 1 (10 kg) was added to the thus-prepared aqueous solution of coconut monoamine acetate and immersed for 5 minutes. Then, it was dehydrated with a centrifugal dehydrator (200 rpm), the electrolytic silver powder was separated from water, and dried with a hot air dryer at 105 ° C. All of the electrolytic silver powders thus obtained did not aggregate even after 6 months and could be used as a metal graphite brush.
【００１２】[0012]
【実施例３】高級脂肪族アミンに有機酸塩として椰子モ
ノアミンサルチル酸塩、椰子ジアミンアジピン酸塩、牛
脂ジアミンサルチル酸塩を各々５cc計量し、水10ｌの入
った容器にそれぞれ加え均一に攪拌した。このように調
整した高級脂肪族アミンの有機酸塩の水溶液に電解銀粉
末（＋75μm 0%, ＋45μm 0.5%, −45μm 99.5%)10Kg投
入し、５分間浸漬した。しかる後、遠心脱水機（200rp
m）で脱水し、電解銀粉末を水と分離し、 105℃の熱風
乾燥器で乾燥した。この様にして得た電解銀粉末は全て
６ヶ月後も凝集なく、金属黒鉛刷子として使用できた。[Example 3] 5 cc of each of the higher aliphatic amines as an organic acid salt of palm monoamine salicylate, coconut diamine adipate, and tallow diamine salicylate was added to a container containing 10 l of water and stirred uniformly. . 10 kg of electrolytic silver powder (+75 μm 0%, +45 μm 0.5%, −45 μm 99.5%) was added to the thus prepared aqueous solution of the organic acid salt of higher aliphatic amine, and the mixture was immersed for 5 minutes. Then, centrifuge dehydrator (200rp
m) and the electrolytic silver powder was separated from water and dried in a hot air dryer at 105 ° C. All of the electrolytic silver powders thus obtained did not aggregate even after 6 months and could be used as a metal graphite brush.
【００１３】[0013]
【比較例１】実施例１で使用した電解銀粉末を本発明の
処理をしないで、30日間放置した結果、＋１00μｍ粉が
４０％以上となり、さらに１mm以上の粗大凝集物も非常
に多く認められ、電刷子用として使用できないものであ
った。Comparative Example 1 The electrolytic silver powder used in Example 1 was allowed to stand for 30 days without the treatment of the present invention. As a result, +100 μm powder was 40% or more, and coarse aggregates of 1 mm or more were also observed. , It could not be used for electric brushes.
【００１４】[0014]
【比較例２】実施例３で使用した電解銀粉末を本発明の
処理をしないで、20日間放置した結果、＋１00μｍ粉が
５０％以上となり、さらに２mm以上の粗大凝集物も非常
に多く認められ、電刷子用として使用できないものであ
った。[Comparative Example 2] The electrolytic silver powder used in Example 3 was left for 20 days without being treated according to the present invention. As a result, +100 µm powder was 50% or more, and coarse agglomerates of 2 mm or more were also observed. , It could not be used for electric brushes.
【００１５】[0015]
【発明の効果】従来までの電解銀粉末は、製造してから
の経時変化が激しく、管理上多くの問題を有していた。
さらに数ヶ月経過した銀粉末の凝集物は非常に強く、再
分散も難しく、高価な銀粉末をむだにすることも有っ
た。EFFECTS OF THE INVENTION Conventional electrolytic silver powders have had many problems in terms of management because of their severe changes with time since their production.
Further, agglomerates of silver powder after several months passed were very strong, re-dispersion was difficult, and expensive silver powder was sometimes wasted.
【００１６】本発明の方法で製造した電解銀粉末は、従
来の粉末性を維持し、かつ６ヶ月後も凝集が生じない、
画期的な電解銀粉末となった。金属黒鉛刷子はもちろ
ん、他の導電性フィラーとしても使用できる。The electrolytic silver powder produced by the method of the present invention maintains the conventional powdery property and does not aggregate even after 6 months.
It became a revolutionary electrolytic silver powder. It can be used not only as a metal graphite brush but also as other conductive filler.
Claims (3)
塩を含む水溶液に浸漬し、しかる後に脱水乾燥すること
を特徴とする電解銀粉末の製造方法。1. A method for producing an electrolytic silver powder, which comprises immersing the electrolytic silver powder in an aqueous solution containing an organic acid salt of a higher aliphatic amine, and then dehydrating and drying.
子数１２〜２２の脂肪族炭化水素を有する脂肪族モノア
ミン又はジアミンと、炭素原子数２〜２３の脂肪族炭化
水素を有するか、あるいは炭素原子数７〜８の芳香族炭
化水素基を有するモノ又はジカルボン酸とからなる塩で
あることを特徴とする請求項１記載の電解銀粉末の製造
方法2. An organic acid salt of a higher aliphatic amine has an aliphatic monoamine or diamine having an aliphatic hydrocarbon having 12 to 22 carbon atoms and an aliphatic hydrocarbon having 2 to 23 carbon atoms, Alternatively, it is a salt consisting of a mono- or dicarboxylic acid having an aromatic hydrocarbon group having 7 to 8 carbon atoms, and the method for producing an electrolytic silver powder according to claim 1.
族アミンの有機酸塩の添加量が20ppm 〜5000ppm である
ことを特徴とする請求項１記載の電解銀粉末の製造方法3. The method for producing an electrolytic silver powder according to claim 1, wherein the amount of the organic acid salt of the higher aliphatic amine added to the aqueous solution in which the electrolytic silver powder is dipped is 20 ppm to 5000 ppm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28827495A JPH09125110A (en) | 1995-11-07 | 1995-11-07 | Production of electrolytic silver powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28827495A JPH09125110A (en) | 1995-11-07 | 1995-11-07 | Production of electrolytic silver powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09125110A true JPH09125110A (en) | 1997-05-13 |
Family
ID=17728063
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28827495A Pending JPH09125110A (en) | 1995-11-07 | 1995-11-07 | Production of electrolytic silver powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09125110A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8118896B2 (en) | 2004-09-23 | 2012-02-21 | Antionette Can | Coated abrasive materials and method of manufacture |
| CN105710379A (en) * | 2016-02-26 | 2016-06-29 | 金川集团股份有限公司 | Method for spraying drying of superfine silver powder |
-
1995
- 1995-11-07 JP JP28827495A patent/JPH09125110A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8118896B2 (en) | 2004-09-23 | 2012-02-21 | Antionette Can | Coated abrasive materials and method of manufacture |
| US9624135B2 (en) | 2004-09-23 | 2017-04-18 | Antionette Can | Polycrystalline abrasive materials and method of manufacture |
| CN105710379A (en) * | 2016-02-26 | 2016-06-29 | 金川集团股份有限公司 | Method for spraying drying of superfine silver powder |
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