JPH06145727A - Production of spheroidal palladium powder - Google Patents
Production of spheroidal palladium powderInfo
- Publication number
- JPH06145727A JPH06145727A JP32499192A JP32499192A JPH06145727A JP H06145727 A JPH06145727 A JP H06145727A JP 32499192 A JP32499192 A JP 32499192A JP 32499192 A JP32499192 A JP 32499192A JP H06145727 A JPH06145727 A JP H06145727A
- Authority
- JP
- Japan
- Prior art keywords
- palladium
- powder
- solution
- palladium powder
- particle size
- 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.)
- Withdrawn
Links
Landscapes
- Manufacture And Refinement Of Metals (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、電子回路の膜導体や電
子部品の電極等に利用される導電性の球状パラジウム粉
末の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a conductive spherical palladium powder used as a film conductor of an electronic circuit or an electrode of an electronic component.
【０００２】[0002]
【従来技術】積層コンデンサーなどは、内部電極をパラ
ジウム粉末を導電性ペーストとして形成している。例え
ば、チタン酸バリウム製積層コンデンサー等は、チタン
酸バリウム絶縁層の間に導電性のパラジウム粉末を含む
ペーストを介在した積層体を形成し、該積層体を一体に
焼成して形成されている。このような導電性ペーストと
して用いられるパラジウム粉末は粒径および外形が不均
一ないし不規則であると、粒子相互の接触不良を生じ易
く、導電不良部分が多くなるので出来るだけ粒径が均一
で、しかも球状の外形を有するものが望まれる。従来、
このようなパラジウム粉末を製造する方法として、パラ
ジウムイオンを含む水溶液に水酸化ナトリウムを加えて
ｐＨを調整し、ヒドラジン、ギ酸、水素化ホウ素ナトリ
ウムなどの還元剤を添加し、パラジウムイオンを還元し
て金属パラジウムとして回収する方法が一般に知られて
いる。2. Description of the Related Art In multilayer capacitors and the like, internal electrodes are formed by using palladium powder as a conductive paste. For example, a barium titanate multilayer capacitor or the like is formed by forming a laminated body in which a paste containing conductive palladium powder is interposed between barium titanate insulating layers, and integrally firing the laminated body. When the palladium powder used as such a conductive paste has a nonuniform or irregular particle diameter and outer shape, poor contact between particles is likely to occur, and defective conductive portions increase, so the particle diameter is as uniform as possible, Moreover, those having a spherical outer shape are desired. Conventionally,
As a method for producing such a palladium powder, sodium hydroxide is added to an aqueous solution containing palladium ions to adjust the pH, and a reducing agent such as hydrazine, formic acid and sodium borohydride is added to reduce the palladium ions. A method of recovering metal palladium is generally known.
【０００３】[0003]
【発明の解決課題】従来の上記パラジウム粉末の製造方
法は、得られるパラジウム粉末の粒径が不均一であり、
また粒子形状も不規則である。この欠点を解消するため
に、原料のパラジウムイオン源として、テトラアンミン
パラジウム(II)塩を用い、還元剤としてヒドラジン化合
物を用いる製造方法も知られている（特開平３−２７７
７０６号公報）が、この方法によっても粒径および外形
の制御は不十分である。しかも、この方法では粒径１μ
m 以下のパラジウム粉末を得るのが困難である。本発明
は、従来の製造方法にける上記課題を解消した製造方法
を提供することを目的とする。According to the conventional method for producing the above-mentioned palladium powder, the particle diameter of the obtained palladium powder is not uniform,
The particle shape is also irregular. In order to solve this drawback, there is also known a production method using a tetraamminepalladium (II) salt as a raw material palladium ion source and a hydrazine compound as a reducing agent (JP-A-3-277).
No. 706), however, the particle size and outer shape are not sufficiently controlled even by this method. Moreover, with this method, the particle size is 1 μm.
It is difficult to obtain palladium powder of m or less. An object of the present invention is to provide a manufacturing method that solves the above problems in the conventional manufacturing method.
【０００４】[0004]
【課題の解決手段】本発明において、パラジウムイオン
を金属パラジウムに還元する際に、還元剤を添加する前
に予めパラジウム溶液と還元剤溶液のｐＨを各々調整す
ることにより粒径が均一でかつ球状のパラジウム粉末を
製造できることが見出された。本発明は上記知見に基づ
き、パラジウムペースト原料として最適な粒径０．１〜
１μm の球状パラジウム粉末の製造を可能にしたもので
ある。本発明によれば、(1) パラジウムイオンを還元し
て金属パラジウムを得る方法において、還元剤を添加す
る前にパラジウムイオンを含む溶液のｐＨを５．５〜９
に調整し、さらに還元剤の溶液のｐＨを１〜７に調整し
て上記パラジウムイオンを含む溶液に添加することによ
り粒径０．１〜 １μm の球状パラジウム粉末を製造す
ることを特徴とする球状パラジウム粉末の製造方法、
(2) パラジウムイオンを含む溶液のｐＨを５〜９に調整
すると共に高分子分散剤を添加する上記(1) の製造方
法、In the present invention, when reducing palladium ions to metallic palladium, the pH of the palladium solution and the reducing agent solution are adjusted in advance before adding the reducing agent, so that the particle diameter is uniform and spherical. It was found that a palladium powder of The present invention is based on the above findings and has an optimum particle size of 0.1 to 0.1 as a palladium paste raw material.
It enables the production of 1 μm spherical palladium powder. According to the present invention, (1) in a method of reducing palladium ions to obtain metallic palladium, the pH of a solution containing palladium ions is adjusted to 5.5 to 9 before adding a reducing agent.
And the pH of the reducing agent solution is adjusted to 1 to 7 and added to the solution containing palladium ions to produce spherical palladium powder having a particle size of 0.1 to 1 μm. A method for producing palladium powder,
(2) The production method according to (1) above, wherein the pH of the solution containing palladium ions is adjusted to 5 to 9 and a polymer dispersant is added.
【０００５】以下に本発明を図示する製造法のフローシ
ートを参照して詳細に説明する。本発明の方法では、パ
ラジウム原料として、ジクロロジアミンパラジウム、ジ
ブロムジアミンパラジウムなどのハロゲン化ジアミンパ
ラジウムに代表されるパラジウムアンミン(II)塩化合物
が用いられる。ジクロロジアミンパラジウムＰｄ（ＮＨ
3）2 Ｃｌ2 を用いる場合を一例として本発明を説明す
ると、ジクロロジアミンパラジウムと塩化アンモニウム
を含む水溶液に、アンモニア水を加えて溶液のｐＨを
５．５〜９、好ましくは、５．９〜６．２に調整して、
パラジウムを溶解する。溶液のｐＨが５．５未満以下で
あるとパラジウムが析出し、ｐＨが９を上回ると得られ
るパラジウム粉末の粒径が１μm より大きくなる。な
お、塩化アンモニウムに代えて硝酸アンモニウムを用い
てもよい。The present invention will be described in detail below with reference to the illustrated flow sheet of the manufacturing method. In the method of the present invention, a palladium ammine (II) salt compound represented by diamine palladium halides such as dichlorodiamine palladium and dibromodiamine palladium is used as the palladium raw material. Dichlorodiamine palladium Pd (NH
3 ) The present invention will be described by taking the case of using 2 Cl 2 as an example. The pH of the solution is adjusted to 5.5 to 9, preferably 5.9 to by adding aqueous ammonia to an aqueous solution containing dichlorodiamine palladium and ammonium chloride. Adjust to 6.2,
Dissolve palladium. If the pH of the solution is less than 5.5, palladium will precipitate, and if the pH exceeds 9, the particle size of the obtained palladium powder will be larger than 1 μm. Note that ammonium nitrate may be used instead of ammonium chloride.
【０００６】上記パラジウム溶液に高分子分散剤を加
え、更に還元剤を加えてパラジウムイオンを金属パラジ
ウムに還元する。高分子分散剤としてはゼラチン、アラ
ビアゴム、ポリエチレングリコールなどが用いられる。
高分子分散剤は粒子形状を制御する作用を果たし、高分
子分散剤を添加することにより均一な球状パラジウム粒
子を得ることができる。高分子分散剤の添加量は１〜６
g/litが好ましい。１ g/lit未満の添加量ではパラジウ
ム粒子が凝集して１μm 以上の粒子になり、また添加量
が６ g/litを超えると沈殿の濾過性が低下する。添加量
が１〜６ g/litの範囲ではｐＨが安定であり１μm 以下
の球形のパラジウム粉末が得られ、かつ溶液での分散性
もよい。A polymer dispersant is added to the palladium solution, and a reducing agent is further added to reduce palladium ions to metallic palladium. As the polymer dispersant, gelatin, gum arabic, polyethylene glycol and the like are used.
The polymer dispersant acts to control the particle shape, and by adding the polymer dispersant, uniform spherical palladium particles can be obtained. The addition amount of the polymer dispersant is 1 to 6
g / lit is preferred. When the amount added is less than 1 g / lit, the palladium particles aggregate to particles of 1 μm or more, and when the amount added exceeds 6 g / lit, the filterability of the precipitate deteriorates. When the amount added is in the range of 1 to 6 g / lit, the pH is stable, spherical palladium powder of 1 μm or less is obtained, and dispersibility in a solution is good.
【０００７】還元剤としてヒドラジン、硫酸ヒドラジン
などのヒドラジン化合物が用いられる。ヒドラジン溶液
はｐＨを１〜７、好ましくは、６．５〜６．８に調整し
て上記パラジウム溶液に添加される。ヒドラジン溶液の
ｐＨが１未満ではパラジウム粉末の粒径が０．１μm よ
り微細になり、またｐＨ７より高いとパラジウム粉末の
粒径が１μm より大きくなる。ヒドラジンの添加によ
り、金属パラジウムが沈殿するので、これを回収する。
濾過時間を短縮するために塩化カルシウム等を添加して
パラジウム粒子を一時的に凝集させてデカンテーション
を行うとよい。回収したパラジウム粉末は乾燥して水分
を除去する。As the reducing agent, hydrazine compounds such as hydrazine and hydrazine sulfate are used. The pH of the hydrazine solution is adjusted to 1 to 7, preferably 6.5 to 6.8 and added to the above palladium solution. When the pH of the hydrazine solution is less than 1, the particle size of the palladium powder becomes finer than 0.1 μm, and when it is higher than pH 7, the particle size of the palladium powder becomes larger than 1 μm. The addition of hydrazine precipitates metallic palladium, which is recovered.
In order to shorten the filtration time, it is advisable to add calcium chloride or the like to temporarily aggregate the palladium particles for decantation. The recovered palladium powder is dried to remove water.
【０００８】以上述べた本発明の製造方法においては、
パラジウム溶液のｐＨとヒドラジン溶液のｐＨとを一定
範囲に調整することにより、パラジウム粉末の粒径を精
度よく制御することができる。粒径制御の一例を図２に
示した。同図は、パラジウム溶液（高分子分散剤0.6%含
有、液温55〜57℃）のｐＨとこれに添加するヒドラジン
溶液のｐＨが、得られるパラジウム粉末の粒径に及ぼす
影響を示すグラフであり、図示されるように、パラジウ
ム粉末の粒径はパラジウム溶液とヒドラジン溶液のｐＨ
に対応して変化している。In the manufacturing method of the present invention described above,
By adjusting the pH of the palladium solution and the pH of the hydrazine solution within a certain range, the particle size of the palladium powder can be controlled accurately. An example of particle size control is shown in FIG. This figure is a graph showing the effect of the pH of a palladium solution (containing 0.6% of a polymer dispersant, a liquid temperature of 55 to 57 ° C.) and the pH of a hydrazine solution added thereto on the particle size of the obtained palladium powder. As shown in the figure, the particle size of the palladium powder depends on the pH of the palladium solution and the hydrazine solution.
Is changing in response to.
【０００９】以下、本発明の実施例を示す。ジクロロジ
アミンパラジウム溶液（Ｐｄ：２０ g/lit）に塩化アン
モニウム４０ g/litとゼラチン３ g/litを加え１リットルの
水溶液としたん後、アンモニア水を加えｐＨ＝６に調整
した。一方、ヒドラジン水和物５０mlに塩酸を加えｐＨ
＝７に調整した。この２液を温度５５℃に加温し、パラ
ジウム溶液を攪拌しながらヒドラジン水溶液を添加し
た。得られたパラジウム微粒子（収率９９％以上）を濾
過、洗浄して電子顕微鏡写真観察を行った。その結果、
このパラジウム粉は粒径０．３μm の球状で均一なもの
であった。Examples of the present invention will be shown below. To a dichlorodiamine palladium solution (Pd: 20 g / lit), 40 g / lit of ammonium chloride and 3 g / lit of gelatin were added to prepare a 1 liter aqueous solution, and then ammonia water was added to adjust the pH to 6. Meanwhile, add hydrochloric acid to 50 ml of hydrazine hydrate to adjust the pH.
= 7 was adjusted. The two liquids were heated to a temperature of 55 ° C., and an aqueous hydrazine solution was added while stirring the palladium solution. The obtained palladium fine particles (yield 99% or more) were filtered and washed, and observed with an electron microscope photograph. as a result,
This palladium powder was spherical and uniform with a particle size of 0.3 μm.
【００１０】[0010]
【発明の効果】本発明の製造方法によれば、粒子形状が
球形であり、粒径が０．１〜１μm のパラジウム粉末を
高収率で得ることができる。本発明の方法は、溶液のｐ
Ｈ調整によってパラジウム粉末の粒径と形状を精度よく
制御できるので容易に実施し易く、工業上の実施に適す
る。According to the production method of the present invention, a palladium powder having a spherical particle shape and a particle diameter of 0.1 to 1 μm can be obtained in a high yield. The method of the present invention uses the solution p
Since the particle size and shape of the palladium powder can be controlled with high precision by adjusting H, it is easy to carry out and is suitable for industrial implementation.
【図１】 本発明の製造方法のフローチャート。FIG. 1 is a flowchart of a manufacturing method of the present invention.
【図２】 本発明の粒径制御効果を示すグラフである。FIG. 2 is a graph showing the particle size control effect of the present invention.
【図３】 実施例で得たパラジウム粉末の粒子構造を示
す電子顕微鏡写真。FIG. 3 is an electron micrograph showing the particle structure of the palladium powder obtained in the example.
Claims (2)
ウムを得る方法において、還元剤を添加する前にパラジ
ウムイオンを含む溶液のｐＨを５．５〜９に調整し、さ
らに還元剤の溶液のｐＨを１〜７に調整して上記パラジ
ウムイオンを含む溶液に添加することにより粒径０．１
〜 １μm の球状パラジウム粉末を製造することを特徴
とする球状パラジウム粉末の製造方法。1. A method of reducing palladium ions to obtain metallic palladium, wherein the pH of the solution containing palladium ions is adjusted to 5.5 to 9 before adding the reducing agent, and the pH of the solution of the reducing agent is further adjusted. The particle size was adjusted to 1 to 7 and added to the solution containing the palladium ion to give a particle size of 0.1.
A method for producing a spherical palladium powder, which comprises producing a spherical palladium powder having a particle size of 1 μm.
〜９に調整すると共に高分子分散剤を添加する請求項１
の製造方法。2. The pH of the solution containing palladium ions is adjusted to 5
A polymer dispersant is added while adjusting to 9 to 9.
Manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32499192A JPH06145727A (en) | 1992-11-10 | 1992-11-10 | Production of spheroidal palladium powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32499192A JPH06145727A (en) | 1992-11-10 | 1992-11-10 | Production of spheroidal palladium powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06145727A true JPH06145727A (en) | 1994-05-27 |
Family
ID=18171914
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32499192A Withdrawn JPH06145727A (en) | 1992-11-10 | 1992-11-10 | Production of spheroidal palladium powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06145727A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999062074A1 (en) * | 1998-05-27 | 1999-12-02 | International Brachytherapy, S.A. | Fluid-jet deposition of radioactive material for brachytherapy devices |
| JP2002246661A (en) * | 2001-02-20 | 2002-08-30 | Toshiba Corp | Processing system of thermoelectric element |
| RU2471007C1 (en) * | 2011-10-04 | 2012-12-27 | Александр Геннадьевич Тарарыкин | Extraction method of metals capable of hydrogen absorption from metals, and plant for its implementation |
| CN102994771A (en) * | 2011-09-13 | 2013-03-27 | 郴州市金贵银业股份有限公司 | Method for extracting palladium sponge from silver electrolysis anode slime parting liquid |
| JP2014169484A (en) * | 2013-03-04 | 2014-09-18 | Sumitomo Metal Mining Co Ltd | Method for producing platinum powder |
| CN110539003A (en) * | 2019-08-09 | 2019-12-06 | 无锡英特派金属制品有限公司 | Production method of palladium powder for removing palladium mirror |
| JP2020143322A (en) * | 2019-03-05 | 2020-09-10 | 国立大学法人 宮崎大学 | Separation recovery method of precious metal and precious metal fine particle recovered by the method |
| CN112809015A (en) * | 2020-12-29 | 2021-05-18 | 有研亿金新材料有限公司 | Preparation method of low-apparent-density micron palladium powder |
-
1992
- 1992-11-10 JP JP32499192A patent/JPH06145727A/en not_active Withdrawn
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999062074A1 (en) * | 1998-05-27 | 1999-12-02 | International Brachytherapy, S.A. | Fluid-jet deposition of radioactive material for brachytherapy devices |
| US6461433B1 (en) | 1998-05-27 | 2002-10-08 | International Brachytherapy, S.A. | Fluid-jet deposition of radioactive material |
| JP2002246661A (en) * | 2001-02-20 | 2002-08-30 | Toshiba Corp | Processing system of thermoelectric element |
| CN102994771A (en) * | 2011-09-13 | 2013-03-27 | 郴州市金贵银业股份有限公司 | Method for extracting palladium sponge from silver electrolysis anode slime parting liquid |
| RU2471007C1 (en) * | 2011-10-04 | 2012-12-27 | Александр Геннадьевич Тарарыкин | Extraction method of metals capable of hydrogen absorption from metals, and plant for its implementation |
| JP2014169484A (en) * | 2013-03-04 | 2014-09-18 | Sumitomo Metal Mining Co Ltd | Method for producing platinum powder |
| JP2020143322A (en) * | 2019-03-05 | 2020-09-10 | 国立大学法人 宮崎大学 | Separation recovery method of precious metal and precious metal fine particle recovered by the method |
| CN110539003A (en) * | 2019-08-09 | 2019-12-06 | 无锡英特派金属制品有限公司 | Production method of palladium powder for removing palladium mirror |
| CN112809015A (en) * | 2020-12-29 | 2021-05-18 | 有研亿金新材料有限公司 | Preparation method of low-apparent-density micron palladium powder |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20000201 |