JPH07145409A - Silver-palladium coprecipitation powder and its production - Google Patents
Silver-palladium coprecipitation powder and its productionInfo
- Publication number
- JPH07145409A JPH07145409A JP31402093A JP31402093A JPH07145409A JP H07145409 A JPH07145409 A JP H07145409A JP 31402093 A JP31402093 A JP 31402093A JP 31402093 A JP31402093 A JP 31402093A JP H07145409 A JPH07145409 A JP H07145409A
- Authority
- JP
- Japan
- Prior art keywords
- silver
- palladium
- containing solution
- reducing agent
- salt
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は貴金属粉末及びその製造
方法に関する。特には銀−パラジウム共沈粉末及びその
製造方法に関する。FIELD OF THE INVENTION The present invention relates to a precious metal powder and a method for producing the same. In particular, it relates to a silver-palladium coprecipitated powder and a method for producing the same.
【０００２】[0002]
【従来の技術】電子工業の分野では、厚膜回路を作製す
るのに貴金属粉末を不活性液体ビヒクル中に分散させた
導電性ペーストが利用されている。この貴金属粉末は、
最近では湿式還元析出法により製造する方法が主流を占
めている。銀−パラジウム合金粉末若しくは銀−パラジ
ウム複合粉末の場合には特公昭４４−２１９６８号公報
に代表される共沈還元法がよく知られている。2. Description of the Related Art In the field of electronics industry, a conductive paste in which a noble metal powder is dispersed in an inert liquid vehicle is used for producing a thick film circuit. This precious metal powder is
Recently, the method of manufacturing by the wet reduction precipitation method has dominated. In the case of silver-palladium alloy powder or silver-palladium composite powder, the coprecipitation reduction method represented by JP-B-44-21968 is well known.
【０００３】ところで、この共沈還元法においては、好
ましい粒子を得るために還元剤の限定又はアンモニア水
等による反応液のｐＨ調整、更には緩衝剤の添加による
ｐＨの安定調整を図るなど、析出粒子の制御が種々行わ
れている。By the way, in this coprecipitation reduction method, precipitation is carried out by limiting the reducing agent or adjusting the pH of the reaction solution with ammonia water or the like in order to obtain preferable particles, and further by adjusting the pH by stabilizing the pH. Various control of particles is performed.
【０００４】例えば、前記公報では金属塩含有溶液中に
塩基性物質を添加しｐＨ４．５〜６．５の下で還元反応
を行わせている。その他、特公昭５８−５５２０４号公
報では還元剤に塩酸ヒドラジンを用い、還元反応はｐＨ
３以上の条件下で行わせており、特公昭６２−２００３
号公報では還元剤にヒドラジンの酸性塩を用い、緩衝剤
を添加してｐＨ１〜１１の範囲内で還元反応を行わせて
いる。更に、特開平２−２９４４１６号公報では還元剤
にヒドラジン化合物を用い、ｐＨのための緩衝剤として
アンモニア化合物を用いている。For example, in the above publication, a basic substance is added to a solution containing a metal salt to carry out a reduction reaction under a pH of 4.5 to 6.5. In addition, in Japanese Patent Publication No. 58-55204, hydrazine hydrochloride is used as a reducing agent, and the reduction reaction is performed at pH.
It is performed under the condition of 3 or more.
In the publication, an acid salt of hydrazine is used as a reducing agent, and a buffering agent is added to carry out the reducing reaction within the range of pH 1-11. Further, in JP-A-2-294416, a hydrazine compound is used as a reducing agent and an ammonia compound is used as a buffering agent for pH.
【０００５】上記従来技術で反応溶液に添加されている
水酸化アンモニウム、アンモニア化合物はいずれもｐＨ
調整又はｐＨの安定化のための緩衝剤としてのみ作用
し、効果としては好ましい大きさ及び形状の粒子が得ら
れるという外観上のもののみに限定され、還元析出され
た金属粉末の特性自体に影響を及ぼす作用はなんら生じ
ていなかった。Both the ammonium hydroxide and the ammonia compound added to the reaction solution in the above-mentioned prior art have pH values.
It acts only as a buffering agent for adjusting or stabilizing the pH, and the effect is limited to only the appearance that particles of a desired size and shape are obtained, and it affects the characteristics of the reduced and precipitated metal powder itself. No effect was produced.
【０００６】[0006]
【発明が解決しようとする課題】上記方法により製造さ
れる金属粉末には未だ０．１μｍ未満の微細粒子の生成
混入を避けることはできない。また、銀−パラジウム共
沈粉末の如き２種の金属塩から製せられる複合共沈粉末
は混合度が不均一であり、その結果低温での合金化は起
こり難いものであった。従って、上記従来技術で得られ
る金属粉末は酸化増量の多いものであり、電極特性には
不満が残るものであった。The metal powder produced by the above method still cannot avoid generation and incorporation of fine particles of less than 0.1 μm. Further, the composite coprecipitated powder made of two kinds of metal salts such as the silver-palladium coprecipitated powder has a non-uniform degree of mixing, and as a result, alloying at a low temperature is difficult to occur. Therefore, the metal powder obtained by the above-mentioned conventional technique has a large amount of increase in oxidation, and the electrode characteristics remain unsatisfactory.
【０００７】そこで、本発明は混合度が均一であるため
低温で合金化が可能であり、且つ０．１μｍ未満の微細
粒子の混入のない実用に適した銀−パラジウム共沈粉末
を提供することを目的とする。及び前記銀−パラジウム
共沈粉末を工業的に安定して供給できるための製造方法
を提供することを目的とする。Therefore, the present invention provides a silver-palladium coprecipitated powder which can be alloyed at a low temperature because the degree of mixing is uniform and which is suitable for practical use without inclusion of fine particles of less than 0.1 μm. With the goal. Another object of the present invention is to provide a method for producing the silver-palladium coprecipitated powder, which can be industrially stably supplied.
【０００８】[0008]
【課題を解決するための手段】上記目的に従い鋭意研究
を進めた結果、次に示す本発明が完成された。As a result of earnest researches in accordance with the above objects, the present invention shown below was completed.
【０００９】即ち、本発明は金属塩を含有する溶液と還
元剤含有溶液とを混合して還元せしめることにより、金
属を析出させ、粉末化する金属粉末の製造方法におい
て、（ａ）銀塩とパラジウム塩とを含有する溶液（以
下、金属塩含有溶液という）のｐＨをアルカリ性領域に
調整する工程、及び別途に（ｂ）蟻酸アンモニウム及び
抱水ヒドラジン化合物を還元剤とする還元剤含有溶液の
ｐＨを酸性領域に調整する工程、（ｃ）前記工程（ａ）
により調製された金属含有溶液と前記工程（ｂ）により
調製された還元剤含有溶液の少なくともどちらか一方の
溶液に酢酸アンモニウム又は炭酸アンモニウムから選択
される少なくとも１種以上を添加する工程、（ｄ）前記
金属含有溶液と前記還元剤含有溶液とを混合し、銀とパ
ラジウムとを同時に還元析出せしめる工程、からなるこ
とを特徴とする、粒子形状がほぼ球状であって粒子径が
０．１〜２．０μｍの範囲内にある銀−パラジウム共沈
粉末の製造方法及び該製造方法により得られる銀−パラ
ジウム共沈粉末に関するものである。That is, according to the present invention, in a method for producing a metal powder in which a metal salt-containing solution and a reducing agent-containing solution are mixed and reduced to precipitate a metal and powdered, (a) a silver salt and A step of adjusting the pH of a solution containing a palladium salt (hereinafter referred to as a metal salt-containing solution) to an alkaline region, and (b) the pH of a reducing agent-containing solution using ammonium formate and a hydrazine hydrate compound as a reducing agent. Adjusting the acid to an acidic region, (c) the step (a)
Adding at least one or more selected from ammonium acetate or ammonium carbonate to the solution containing at least one of the metal-containing solution prepared in step (b) and the reducing agent-containing solution prepared in step (b), (d) A step of mixing the metal-containing solution and the reducing agent-containing solution to simultaneously reduce and precipitate silver and palladium, wherein the particle shape is substantially spherical and the particle diameter is 0.1 to 2 The present invention relates to a method for producing a silver-palladium coprecipitated powder in the range of 0.0 μm and a silver-palladium coprecipitated powder obtained by the production method.
【００１０】[0010]
【好適な実施態様及び作用】本発明の製造法により得ら
れる銀−パラジウム共沈粉末はその粒子形状がほぼ球状
であって、粒子径が０．１〜２．０μｍと粒度分布の幅
の狭いものである。このような銀−パラジウム共沈粉末
は、ペーストにした際の印刷性が良好である。更に均一
に混合したものであり、低温で合金化が起こるので酸化
増量（ＴＧＡ）が少ないという特性を有し、コンデンサ
ー電極に好適である。BEST MODE FOR CARRYING OUT THE INVENTION The silver-palladium coprecipitated powder obtained by the production method of the present invention has a substantially spherical particle shape and a narrow particle size distribution of 0.1 to 2.0 μm. It is a thing. Such silver-palladium coprecipitated powder has good printability when formed into a paste. Further, it is a homogeneous mixture, and since it alloys at a low temperature, it has a characteristic that the amount of oxidation increase (TGA) is small, and it is suitable for a capacitor electrode.
【００１１】本発明の各構成要件がその効果にどのよう
に寄与しているのかは、まだ十分にわかっていない。し
かし、いずれの一つが欠けても上記のような銀−パラジ
ウム共沈粉末を得ることはできない。It is not yet fully understood how each constituent element of the present invention contributes to its effect. However, the silver-palladium coprecipitation powder as described above cannot be obtained even if any one of them is lacking.
【００１２】まず、還元剤は還元力が強力なヒドラジン
化合物を適用するが、抱水ヒドラジンと蟻酸アンモニウ
ムを組み合わせて使用しなければならない。これ以外の
還元剤では上記の特性を有する金属粉末を安定して得る
ことができない。一般に還元剤は反応溶液のｐＨの相異
によりその還元力に差異が生じ大きく変動する。例えば
抱水ヒドラジンの場合には、酸性側では銀塩に対する還
元力は殆どないが、アルカリ性側では銀塩に対する還元
力が逆に強く働きパラジウム塩の還元との速度に差異が
生じ、銀とパラジウムが別々に析出される。First, as the reducing agent, a hydrazine compound having a strong reducing power is applied, but hydrazine hydrate and ammonium formate must be used in combination. Other reducing agents cannot stably obtain the metal powder having the above characteristics. Generally, the reducing agent has a large difference in its reducing power due to the difference in pH of the reaction solution, which causes a large fluctuation. For example, in the case of hydrazine hydrate, there is almost no reducing power to the silver salt on the acidic side, but on the alkaline side, the reducing power to the silver salt is conversely strong, which causes a difference in the speed with the reduction of the palladium salt. Are deposited separately.
【００１３】そこで、本発明の製造法では、パラジウム
塩の還元剤として酸性領域で抱水ヒドラジンを用い、銀
塩の還元を補うために、抱水ヒドラジンがパラジウム塩
に対するのと同程度の還元力を銀塩に対して酸性領域で
有する蟻酸アンモニウムを組み合わせて使用するもので
ある。この還元剤の使用により、銀塩とパラジウム塩と
は同程度に還元析出してくるので混合度のよい共沈粉末
が得られると考える。Therefore, in the production method of the present invention, hydrazine hydrate is used in the acidic region as a reducing agent for the palladium salt, and in order to supplement the reduction of the silver salt, hydrazine hydrate has the same reducing power as that for the palladium salt. Is used in combination with ammonium formate, which has a silver salt in an acidic region. It is considered that by using this reducing agent, the silver salt and the palladium salt are reduced and precipitated to the same extent, so that a coprecipitated powder with a good degree of mixing can be obtained.
【００１４】抱水ヒドラジンと蟻酸アンモニウムとの混
合比率は、所望の銀−パラジウム共沈粉末における銀と
パラジウムとの混合比に依存する。還元剤の合計量は還
元反応が完全に進行させるための理論量より過剰に用い
る方が好ましいが、銀塩又はパラジウム塩を還元させる
のに必要な１．５倍当量もあれば十分である。The mixing ratio of hydrazine hydrate and ammonium formate depends on the mixing ratio of silver and palladium in the desired silver-palladium coprecipitated powder. The total amount of the reducing agents is preferably used in excess of the theoretical amount for completely proceeding the reduction reaction, but 1.5 times the equivalent amount necessary for reducing the silver salt or the palladium salt is sufficient.
【００１５】反応溶液のｐＨ値は、金属粉末の粒子の核
形成速度及び粒子成長速度を左右する重大な因子であ
り、ｐＨが低過ぎると粒子成長速度が遅いため微粉しか
得られず、逆にｐＨが高過ぎても金属粒子の核形成速度
が粒子成長速度を上廻ってしまうので、生成してくる粒
子のほとんどが０．１μｍ未満のものである。The pH value of the reaction solution is an important factor that influences the nucleation rate and the particle growth rate of the particles of the metal powder. If the pH is too low, the particle growth rate will be slow and only fine powder will be obtained. Even if the pH is too high, the nucleation rate of metal particles exceeds the particle growth rate, so most of the particles produced are less than 0.1 μm.
【００１６】本発明においては上述の理由により、還元
剤含有溶液のｐＨは酸性領域であることを要し、好まし
くはｐＨ４以上ｐＨ７以下である。しかし、金属塩含有
溶液も酸性領域にすると、両溶液を混合した時に核形成
反応が急激に進み粒子成長速度との均衡がとれず生成す
る粉末は０．１μｍ未満の微細粒子のみであった。依っ
て、金属塩含有溶液のｐＨはアルカリ性領域にあること
を要し、ｐＨ７以上ｐＨ１１以下であることが好まし
い。即ち、本発明において両溶液を混合して行われる金
属塩の還元反応はｐＨ７〜ｐＨ10.5の領域で行われるこ
とが好ましい。In the present invention, the pH of the reducing agent-containing solution needs to be in the acidic region for the above-mentioned reason, and is preferably pH 4 or more and pH 7 or less. However, when the metal salt-containing solution was also in the acidic region, the nucleation reaction proceeded rapidly when the two solutions were mixed, and the powder could not be balanced with the particle growth rate, and only fine particles of less than 0.1 μm were produced. Therefore, the pH of the metal salt-containing solution needs to be in the alkaline range, and is preferably pH 7 or higher and pH 11 or lower. That is, in the present invention, the reduction reaction of the metal salt, which is carried out by mixing both solutions, is preferably carried out in the range of pH 7 to pH 10.5.
【００１７】更に、金属含有溶液及び還元剤含有溶液の
少なくともどちらか一方には酢酸アンモニウム又は炭酸
アンモニウムの少なくとも１種以上を添加しておくこと
が本発明のもう一つの特徴である。このことにより、前
記両溶液を混合した際の還元析出反応において銀塩とパ
ラジウム塩との還元反応が調和されゆっくりと制御され
ながら行われ、銀成分とパラジウム成分との混合度がよ
く且つ０．１〜２．０μｍ（ＳＥＭ観察）という極めて
粒度分布の幅が狭い粒子が生成し、低温で合金化するた
め焼成時の酸化増量が少ないものとなる。酢酸アンモニ
ウム又は炭酸アンモニウム以外のアンモニア化合物の存
在ではこの効果は得られず、生成する共沈粉末の合金化
温度は高いものであり焼成時の酸化増量も多くなる。Further, it is another feature of the present invention that at least one of ammonium acetate and ammonium carbonate is added to at least one of the metal-containing solution and the reducing agent-containing solution. As a result, the reduction reaction between the silver salt and the palladium salt in the reduction precipitation reaction when the two solutions are mixed is performed while being coordinated and controlled slowly, and the mixing degree of the silver component and the palladium component is good and the value of 0. Particles having an extremely narrow particle size distribution of 1 to 2.0 μm (observed by SEM) are generated and alloyed at a low temperature, so that the amount of increase in oxidation during firing becomes small. This effect cannot be obtained in the presence of an ammonium compound other than ammonium acetate or ammonium carbonate, and the alloying temperature of the coprecipitated powder produced is high and the amount of oxidation increase during firing is large.
【００１８】前記アンモニウム化合物の好ましい添加形
態としては、金属塩含有溶液には硝酸アンモニウム又は
酢酸アンモニウム又は炭酸アンモニウムから選択される
少なくとも１種以上を添加し、又は／及び還元剤含有溶
液には硝酸アンモニウム又は酢酸アンモニウムを添加す
ることである。As a preferable addition form of the ammonium compound, at least one selected from ammonium nitrate, ammonium acetate or ammonium carbonate is added to the metal salt-containing solution, and / or ammonium nitrate or acetic acid is added to the reducing agent-containing solution. Ammonium is added.
【００１９】但し、金属塩含有溶液に硝酸アンモニウム
を添加する場合は更に金属塩含有溶液に酢酸アンモニウ
ム又は炭酸アンモニウムから少なくとも１種を添加する
か、還元剤含有溶液に酢酸アンモニウムを添加すること
を要する。一方、還元剤含有溶液に硝酸アンモニウムを
添加する場合には、同様に更に還元剤含有溶液に酢酸ア
ンモニウムを添加するか、金属塩含有溶液に酢酸アンモ
ニウム又は炭酸アンモニウムの中少なくとも１種を添加
しなければならない。However, when ammonium nitrate is added to the metal salt-containing solution, it is necessary to further add at least one of ammonium acetate or ammonium carbonate to the metal salt-containing solution or ammonium acetate to the reducing agent-containing solution. On the other hand, in the case of adding ammonium nitrate to the reducing agent-containing solution, similarly, ammonium acetate must be further added to the reducing agent-containing solution, or at least one of ammonium acetate or ammonium carbonate must be added to the metal salt-containing solution. I won't.
【００２０】還元反応は還元析出が生じる２５℃以上で
あればよいが、析出した銀とパラジウムとの合金化のし
やすさの観点からすれば、還元析出温度が高い程好まし
い。しかるに、反応温度が高くなると析出粒子のサイズ
が小さくなるので好ましくは４０℃から６０℃の範囲内
が最も好ましい。The reduction reaction may be performed at 25 ° C. or higher at which reduction precipitation occurs, but from the viewpoint of easy alloying of the deposited silver and palladium, a higher reduction precipitation temperature is more preferable. However, since the size of the precipitated particles becomes smaller as the reaction temperature becomes higher, it is most preferably in the range of 40 ° C to 60 ° C.
【００２１】[0021]
【発明の効果】本発明により得られる銀−パラジウム共
沈粉末はその粒子形状がほぼ球状であって、粒子径が
０．１〜２．０μｍの範囲内にあり粒度分布の幅の狭い
ものである。このような銀−パラジウム共沈粉末は、ペ
ーストにした際の印刷性が良好であり、且つ銀とパラジ
ウムとが均一に混合分散し低温で合金化するので酸化増
量（ＴＧＡ）が少ないという特性を有し、コンデンサー
電極に好適である。また、本発明の製造方法により、上
記の銀−パラジウム共沈粉末が工業的に安定供給するこ
とができる。The silver-palladium co-precipitated powder obtained according to the present invention has a substantially spherical particle shape and a particle diameter in the range of 0.1 to 2.0 μm and a narrow particle size distribution. is there. Such a silver-palladium coprecipitated powder has good printability when formed into a paste, and since silver and palladium are uniformly mixed and dispersed and alloyed at a low temperature, there is a characteristic that the amount of oxidation increase (TGA) is small. It has, and is suitable for a capacitor electrode. The silver-palladium coprecipitated powder can be stably supplied industrially by the production method of the present invention.
【００２２】[0022]
【評価試験】下記表１から表３に記載の処方に示す金属
塩含有溶液及び還元剤含有溶液をそれぞれ調製し、混合
して銀−パラジウム共沈粉末を製造した。また、製造さ
れた共沈粉末についてそれぞれ粒子径を測定し、更に２
５０℃で焼成しその前後での酸化増量を調べ、その結果
を表４に示す。また、参考例１−２、実施例２−２、比
較例２及び実施例２−１、実施例３について、比較例１
−１、実施例４及び比較例３について、それぞれ共沈粉
末を２５０℃で焼成後Ｘ線分析を行い合金化の程度を調
べた。[Evaluation Test] A metal salt-containing solution and a reducing agent-containing solution having the formulations shown in Tables 1 to 3 below were prepared and mixed to produce a silver-palladium coprecipitated powder. In addition, the particle size of each of the produced coprecipitated powders was measured, and further 2
The amount of oxidation increase before and after firing at 50 ° C. was examined, and the results are shown in Table 4. In addition, regarding Reference Example 1-2, Example 2-2, Comparative Example 2 and Example 2-1, and Example 3, Comparative Example 1
-1, Example 4, and Comparative Example 3 were each subjected to X-ray analysis after firing the coprecipitated powder at 250 ° C. to examine the degree of alloying.
【００２３】Ｘ線分析の測定条件は次の通りである。 Ｘ線源 ：Ｃｕ 出力 ：５０ｋＶ，５０ｍＡ スリット系 ：１°−０．１５ｍｍ−１° スキャン速度：４°／分 計数ステップ：０．０２°（２θ）The measurement conditions for X-ray analysis are as follows. X-ray source: Cu output: 50 kV, 50 mA Slit system: 1 ° -0.15 mm-1 ° Scan speed: 4 ° / min Counting step: 0.02 ° (2θ)
【００２４】[0024]
【表１】 [Table 1]
【００２５】[0025]
【表２】 [Table 2]
【００２６】[0026]
【表３】 [Table 3]
【００２７】[0027]
【表４】 [Table 4]
【００２８】比較例１−１及び比較例１−２と参考例１
−１及び参考例１−２との間では使用した還元剤の種類
が異なる（表１参照）。本発明の如く蟻酸アンモニウム
と抱水ヒドラジンとを組み合わせて還元剤とした参考例
の方が比較例に比べて、微細粒子が生成せず粒子径の揃
った共沈粉末を得ることができた（表４参照）。Comparative Examples 1-1 and 1-2 and Reference Example 1
-1 and Reference Example 1-2 differ in the type of reducing agent used (see Table 1). As in the present invention, the reference example in which ammonium formate and hydrazine hydrate were combined and used as the reducing agent was able to obtain a coprecipitated powder in which fine particles were not formed and whose particle size was uniform (compared to the comparative example) ( See Table 4).
【００２９】図３〜図７にてそれぞれ実施例１、参考例
１−１、参考例１−２、比較例１−１及び比較例１−２
の生成粒子の電子顕微鏡写真を示す（倍率：上段×１０
００、下段×５０００）。比較例では双方とも微細粒子
が多量に混入していることが確認される。一方、参考例
及び実施例では粒子形状が球状でほぼ揃っていることが
確認できる。即ち、本発明に示す還元剤の組み合わせに
よって、印刷適正を有する粒子径を持つ銀−パラジウム
共沈粉末を得ることができる。3 to 7, Example 1, Reference Example 1-1, Reference Example 1-2, Comparative Example 1-1 and Comparative Example 1-2, respectively.
3 is an electron micrograph of particles produced in Example 1 (magnification: upper row × 10
00, lower row x 5000). In both comparative examples, it is confirmed that a large amount of fine particles are mixed. On the other hand, in the reference example and the example, it can be confirmed that the particle shapes are spherical and substantially uniform. That is, a silver-palladium coprecipitated powder having a particle size suitable for printing can be obtained by combining the reducing agents shown in the present invention.
【００３０】また、酸化増量を比較すると、参考例１−
１及び参考例１−２の方が比較例１−１及び比較例１−
２よりも相対的に少なく、実施例１は更に少ない酸化増
量を示した。このことから、本発明において還元剤の種
類の限定の他に炭酸アンモニウム若しくは酢酸アンモニ
ウムの添加が重要であることがわかる。Further, comparing the oxidation weight increases, Reference Example 1-
1 and Reference Example 1-2 are Comparative Examples 1-1 and 1-
Relatively less than 2, Example 1 showed an even lower oxidation gain. From this, it is understood that addition of ammonium carbonate or ammonium acetate is important in the present invention in addition to the limitation of the type of reducing agent.
【００３１】次に、添加剤としてのアンモニア化合物の
種類について比較した（表２参照）。比較例２、実施例
２−１及び実施例２−２で生成した共沈粉末を焼成しＸ
線分析したところ、酢酸アンモニウム又は炭酸アンモニ
ウムの少なくとも１種以上を添加した実施例２−１及び
実施例２−２はいずれも他のアンモニア化合物を添加し
た比較例２に比べ、最大ピークが高角側の方へシフトし
ており合金化が進んでいることを示した（図１参照）。Next, the types of ammonia compounds as additives were compared (see Table 2). The coprecipitated powders produced in Comparative Example 2, Example 2-1, and Example 2-2 were fired to obtain X.
As a result of line analysis, in each of Example 2-1 and Example 2-2 in which at least one kind of ammonium acetate or ammonium carbonate was added, the maximum peak was higher in the high angle side than Comparative Example 2 in which another ammonia compound was added. , Indicating that alloying is progressing (see FIG. 1).
【００３２】更に、参考例１−２と実施例２−１及び実
施例２−２のＸ線スペクトルを比較すると（図１参
照）、実施例２−１及び実施例２−２の最大ピークは参
考例１−２より高角側へシフトしていることを示し、炭
酸アンモニウム若しくは酢酸アンモニウムの添加による
効果は粒子形状及び大きさといった外観上への効果にと
どまらず、銀−パラジウム共沈粉末自体へも影響を及ぼ
していることが認められる。Further, when the X-ray spectra of Reference Example 1-2 and Example 2-1 and Example 2-2 are compared (see FIG. 1), the maximum peaks of Example 2-1 and Example 2-2 are It was shown that the angle was shifted to a higher angle side than Reference Example 1-2, and the effect of adding ammonium carbonate or ammonium acetate was not limited to the effect on the appearance such as the particle shape and size, but the effect of adding silver-palladium coprecipitated powder itself. Is also affected.
【００３３】また、実施例２−１及び実施例２−２はい
ずれも比較例２に比べて酸化増量が少なかった（表４参
照）。即ち、本発明に係る銀−パラジウム共沈粉末はコ
ンデンサー電極の特性に優れている。In each of Examples 2-1 and 2-2, the amount of increased oxidation was smaller than that of Comparative Example 2 (see Table 4). That is, the silver-palladium coprecipitated powder according to the present invention is excellent in the characteristics of the capacitor electrode.
【００３４】同様の試験を銀とパラジウムとの配合比を
変更して行った（表３参照）。比較例３と実施例４によ
り生成した共沈粉末を焼成しＸ線分析したところ（図２
参照）、実施例４は比較例３に比べて最大ピークが高角
側へシフトしており合金化が進んでいることを示してい
る。両者の酸化増量はほぼ同等であった（表４参照）。
しかし、図１に示す実施例３は実施例４よりも更に合金
化が進んでおり、酸化増量が少なくなっている。同様に
実施例５及び実施例６でも合金化は実施例４より更に進
んでおり（データは示さず）、酸化増量も少ないかった
（表４参照）。A similar test was conducted by changing the compounding ratio of silver and palladium (see Table 3). The coprecipitated powders produced in Comparative Example 3 and Example 4 were fired and subjected to X-ray analysis (see FIG. 2).
Example 4 shows that the maximum peak is shifted to the high angle side as compared with Comparative Example 3, and alloying is progressing. The oxidative weight gains of both were almost the same (see Table 4).
However, the alloying of Example 3 shown in FIG. 1 is more advanced than that of Example 4, and the amount of oxidation increase is small. Similarly, in Examples 5 and 6, alloying was further advanced than that in Example 4 (data not shown), and the amount of oxidation increase was also small (see Table 4).
【００３５】以上述べたように、本発明に係る銀−パラ
ジウム共沈粉末は粒子形状がほぼ球状であり且つ粒度分
布の幅の狭い範囲内の粒子径を有する粉末であるので、
印刷特性に優れており、更には銀とパラジウムとが均一
に混合しており低温で合金化が進み且つ酸化増量の少な
いものであり、コンデンサー電極特性に優れている。As described above, the silver-palladium coprecipitated powder according to the present invention has a substantially spherical particle shape and has a particle diameter within a narrow range of particle size distribution.
It has excellent printing characteristics, and further, silver and palladium are uniformly mixed, alloying proceeds at a low temperature, and the amount of increase in oxidation is small, resulting in excellent capacitor electrode characteristics.
【図１】本発明の実施態様を示す実施例２−１、実施例
２−２、実施例３及びその比較品である参考例１−２、
比較例２で得られた銀−パラジウム共沈粉末を２５０℃
で焼成したものをＸ線分析した結果を示すスペクトル図
である。FIG. 1 shows Example 2-1, Example 2-2, Example 3 showing the embodiment of the present invention and Reference Example 1-2 which is a comparative product thereof.
The silver-palladium coprecipitated powder obtained in Comparative Example 2 was heated to 250 ° C.
It is a spectrum figure which shows the result of having X-ray-analyzed what was baked by.
【図２】本発明の実施態様を示す実施例４及びその比較
品である比較例１−１、比較例３で得られた銀−パラジ
ウム共沈粉末を２５０℃で焼成したものをＸ線分析した
結果を示すスペクトル図である。FIG. 2 is an X-ray analysis of the silver-palladium coprecipitated powders obtained in Example 4 showing the embodiment of the present invention and its comparative products Comparative Example 1-1 and Comparative Example 3 and fired at 250 ° C. It is a spectrum figure which shows the result.
【図３】実施例１により製造した本発明品の銀−パラジ
ウム共沈粉末の電子顕微鏡写真であり、前記共沈粉末の
粒子構造を現わす。上段は倍率が×１０００であり、下
段は前記上段の白枠部分を×５０００に拡大したもので
ある。FIG. 3 is an electron micrograph of a silver-palladium coprecipitated powder of the present invention produced according to Example 1, showing a particle structure of the coprecipitated powder. The upper part has a magnification of × 1000, and the lower part is an enlargement of the white frame portion of the upper part to × 5,000.
【図４】参考例１−１により製造した本発明の参考品の
銀−パラジウム共沈粉末の電子顕微鏡写真であり、前記
共沈粉末の粒子構造を現わす。上段は倍率が×１０００
であり、下段は前記上段の白枠部分を×５０００に拡大
したものである。FIG. 4 is an electron micrograph of a silver-palladium coprecipitated powder of a reference product of the present invention produced in Reference Example 1-1, showing a particle structure of the coprecipitated powder. Magnification is x1000 in the upper row
In the lower part, the white frame part in the upper part is enlarged to x5000.
【図５】参考例１−２により製造した本発明の参考品の
銀−パラジウム共沈粉末の電子顕微鏡写真であり、前記
共沈粉末の粒子構造を現わす。上段は倍率が×１０００
であり、下段は前記上段の白枠部分を×５０００に拡大
したものである。FIG. 5 is an electron micrograph of a silver-palladium coprecipitated powder as a reference product of the present invention manufactured in Reference Example 1-2, showing the particle structure of the coprecipitated powder. Magnification is x1000 in the upper row
In the lower part, the white frame part in the upper part is enlarged to x5000.
【図６】比較例１−１により製造した本発明に対する比
較品の銀−パラジウム共沈粉末の電子顕微鏡写真であ
り、前記共沈粉末の粒子構造を現わす。上段は倍率が×
１０００であり、下段は前記上段の白枠部分を×５００
０に拡大したものである。FIG. 6 is an electron micrograph of a silver-palladium co-precipitated powder of a comparative product of the present invention prepared in Comparative Example 1-1, showing the particle structure of the co-precipitated powder. Magnification is × in the upper row
1000, and the lower part is the upper white frame part × 500.
It is expanded to zero.
【図７】比較例１−２により製造した本発明に対する比
較品の銀−パラジウム共沈粉末の電子顕微鏡写真であ
り、前記共沈粉末の粒子構造を現わす。上段は倍率が×
１０００であり、下段は前記上段の白枠部分を×５００
０に拡大したものである。FIG. 7 is an electron micrograph of a silver-palladium coprecipitated powder of a comparative product prepared according to Comparative Example 1-2, showing the particle structure of the coprecipitated powder. Magnification is × in the upper row
1000, and the lower part is the upper white frame part × 500.
It is expanded to zero.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 猿木 友理恵 愛知県名古屋市西区則武新町三丁目１番36 号 株式会社ノリタケカンパニーリミテド 内 (72)発明者 滝本 昭夫 愛知県名古屋市西区則武新町三丁目１番36 号 株式会社ノリタケカンパニーリミテド 内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Yurie Saruki, 1-3-1, Noritake Shinmachi, Nishi-ku, Nagoya, Aichi Prefecture, No. 36 Noritake Co., Ltd. (72) Inventor Akio Takimoto, 3-chome, Noritake Shincho, Nishi-ku, Nagoya, Aichi Prefecture No. 36 Noritake Company Limited Limited
Claims (6)
を混合して還元せしめることにより、金属を析出させ、
粉末化する金属粉末の製造方法において、 （ａ）銀塩とパラジウム塩とを含有する溶液（以下、金
属塩含有溶液という）のｐＨをアルカリ性領域に調整す
る工程、 及び別途に （ｂ）蟻酸アンモニウム及び抱水ヒドラジン化合物を還
元剤とする還元剤含有溶液のｐＨを酸性領域に調整する
工程、 （ｃ）前記工程（ａ）により調製された金属含有溶液と
前記工程（ｂ）により調製された還元剤含有溶液の少な
くともどちらか一方の溶液に酢酸アンモニウム又は炭酸
アンモニウムから選択される少なくとも１種以上を添加
する工程、 （ｄ）前記金属含有溶液と前記還元剤含有溶液とを混合
し、銀とパラジウムとを同時に還元析出せしめる工程、 からなることを特徴とする、粒子形状がほぼ球状であっ
て粒子径が０．１〜２．０μｍの範囲内にある銀−パラ
ジウム共沈粉末の製造方法。1. A metal salt is precipitated by mixing a solution containing a metal salt and a solution containing a reducing agent for reduction.
In the method for producing a powdered metal powder, (a) a step of adjusting the pH of a solution containing a silver salt and a palladium salt (hereinafter referred to as a metal salt-containing solution) to an alkaline region, and (b) ammonium formate separately. And a step of adjusting the pH of the reducing agent-containing solution using a hydrazine hydrate compound as a reducing agent in an acidic region, (c) the metal-containing solution prepared by the step (a) and the reduction prepared by the step (b) A step of adding at least one selected from ammonium acetate and ammonium carbonate to at least one of the agent-containing solutions, (d) mixing the metal-containing solution and the reducing-agent-containing solution, and silver and palladium And a step of simultaneously reducing and precipitating, and the particle shape is substantially spherical and the particle diameter is within the range of 0.1 to 2.0 μm. Silver - palladium co-precipitated powder manufacturing method.
された金属塩含有溶液に酢酸アンモニウム又は炭酸アン
モニウムから選択される少なくとも１種以上を添加する
ことを特徴とする請求項１記載の銀−パラジウム共沈粉
末の製造方法。2. In the step (c), at least one selected from ammonium acetate and ammonium carbonate is added to the metal salt-containing solution prepared in the step (a). Of the silver-palladium co-precipitation powder of 1.
された還元剤含有溶液に酢酸アンモニウムを添加するこ
とを特徴とする請求項１又は２記載の銀−パラジウム共
沈粉末の製造方法。3. The production of silver-palladium coprecipitated powder according to claim 1, wherein ammonium acetate is added to the reducing agent-containing solution prepared in step (b) in step (c). Method.
された金属塩含有溶液に硝酸アンモニウム塩を添加する
請求項２又は３記載の銀−パラジウム共沈粉末の製造方
法。4. The method for producing a silver-palladium coprecipitated powder according to claim 2, wherein ammonium nitrate is added to the metal salt-containing solution prepared in step (a) in step (c).
された金属塩含有溶液に硝酸アンモニウム塩を添加する
請求項２又は３記載の銀−パラジウム共沈粉末の製造方
法。5. The method for producing a silver-palladium coprecipitated powder according to claim 2, wherein ammonium nitrate is added to the metal salt-containing solution prepared in step (b) in step (c).
液（以下、金属塩含有溶液という）のｐＨをアルカリ性
領域に調整する工程、 及び別途に （ｂ）蟻酸アンモニウム及び抱水ヒドラジン化合物を還
元剤とする還元剤含有溶液のｐＨを酸性領域に調整する
工程、 （ｃ）前記工程（ａ）により調製された金属含有溶液と
前記工程（ｂ）により調製された還元剤含有溶液の少な
くともどちらか一方の溶液に酢酸アンモニウム又は炭酸
アンモニウムから選択される少なくとも１種以上を添加
する工程、 （ｄ）前記金属含有溶液と前記還元剤含有溶液とを混合
し、銀とパラジウムとを同時に還元析出せしめる工程、 からなる方法により製造されることを特徴とする粒子形
状がほぼ球状であって粒子径が０．１〜２．０μｍの範
囲内にある銀−パラジウム共沈粉末。6. A step of (a) adjusting the pH of a solution containing a silver salt and a palladium salt (hereinafter referred to as a metal salt-containing solution) to an alkaline range, and (b) an ammonium formate and a hydrazine hydrate compound separately. Adjusting the pH of the reducing agent-containing solution having a reducing agent in the acidic region, (c) at least the metal-containing solution prepared in the step (a) and the reducing agent-containing solution prepared in the step (b) A step of adding at least one or more selected from ammonium acetate or ammonium carbonate to either one of the solutions, (d) mixing the metal-containing solution and the reducing agent-containing solution, and simultaneously reducing and depositing silver and palladium The silver-para particle having a substantially spherical particle shape and a particle diameter in the range of 0.1 to 2.0 μm, characterized in that it is manufactured by a method comprising Co-precipitated powder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31402093A JP3343283B2 (en) | 1993-11-22 | 1993-11-22 | Silver-palladium coprecipitated powder and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31402093A JP3343283B2 (en) | 1993-11-22 | 1993-11-22 | Silver-palladium coprecipitated powder and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07145409A true JPH07145409A (en) | 1995-06-06 |
| JP3343283B2 JP3343283B2 (en) | 2002-11-11 |
Family
ID=18048242
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31402093A Expired - Fee Related JP3343283B2 (en) | 1993-11-22 | 1993-11-22 | Silver-palladium coprecipitated powder and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3343283B2 (en) |
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|---|---|---|---|---|
| JP2007063657A (en) * | 2005-09-02 | 2007-03-15 | Chiba Inst Of Technology | Permanent magnet material |
| WO2008018718A1 (en) * | 2006-08-07 | 2008-02-14 | Inktec Co., Ltd. | Process for preparation of silver nanoparticles, and the compositions of silver ink containing the same |
| JP2009191354A (en) * | 2007-02-27 | 2009-08-27 | Mitsubishi Materials Corp | Method for synthesizing metal nanoparticle |
| US7955528B2 (en) * | 2005-03-04 | 2011-06-07 | Inktec Co., Ltd | Conductive inks and manufacturing method thereof |
| US9580811B2 (en) | 2007-02-27 | 2017-02-28 | Mitsubishi Materials Corporation | Dispersion of metal nanoparticles, method for producing the same, and method for synthesizing metal nanoparticles |
-
1993
- 1993-11-22 JP JP31402093A patent/JP3343283B2/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7955528B2 (en) * | 2005-03-04 | 2011-06-07 | Inktec Co., Ltd | Conductive inks and manufacturing method thereof |
| JP2007063657A (en) * | 2005-09-02 | 2007-03-15 | Chiba Inst Of Technology | Permanent magnet material |
| WO2008018718A1 (en) * | 2006-08-07 | 2008-02-14 | Inktec Co., Ltd. | Process for preparation of silver nanoparticles, and the compositions of silver ink containing the same |
| KR100918231B1 (en) * | 2006-08-07 | 2009-09-21 | 주식회사 잉크테크 | Process for preparing silver nanoparticles or silver nanocolloid, and the compositions of silver ink containing the silver nanoparticles |
| US8282860B2 (en) | 2006-08-07 | 2012-10-09 | Inktec Co., Ltd. | Process for preparation of silver nanoparticles, and the compositions of silver ink containing the same |
| JP2009191354A (en) * | 2007-02-27 | 2009-08-27 | Mitsubishi Materials Corp | Method for synthesizing metal nanoparticle |
| US9580811B2 (en) | 2007-02-27 | 2017-02-28 | Mitsubishi Materials Corporation | Dispersion of metal nanoparticles, method for producing the same, and method for synthesizing metal nanoparticles |
| US9580810B2 (en) | 2007-02-27 | 2017-02-28 | Mitsubishi Materials Corporation | Dispersion of metal nanoparticles, method for producing the same, and method for synthesizing metal nanoparticles |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3343283B2 (en) | 2002-11-11 |
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