JP2001073001A - Production of nickel powder and nickel powder - Google Patents
Production of nickel powder and nickel powderInfo
- Publication number
- JP2001073001A JP2001073001A JP24495399A JP24495399A JP2001073001A JP 2001073001 A JP2001073001 A JP 2001073001A JP 24495399 A JP24495399 A JP 24495399A JP 24495399 A JP24495399 A JP 24495399A JP 2001073001 A JP2001073001 A JP 2001073001A
- Authority
- JP
- Japan
- Prior art keywords
- nickel powder
- hydrogen reduction
- oxygen content
- reduction treatment
- weight
- 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
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title claims abstract description 96
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 17
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 57
- 239000001257 hydrogen Substances 0.000 claims abstract description 54
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 54
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 53
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 53
- 239000001301 oxygen Substances 0.000 claims abstract description 53
- 238000005245 sintering Methods 0.000 claims abstract description 45
- 229910021586 Nickel(II) chloride Inorganic materials 0.000 claims abstract description 12
- QMMRZOWCJAIUJA-UHFFFAOYSA-L nickel dichloride Chemical compound Cl[Ni]Cl QMMRZOWCJAIUJA-UHFFFAOYSA-L 0.000 claims abstract description 12
- 239000002245 particle Substances 0.000 claims description 7
- 230000003647 oxidation Effects 0.000 abstract description 21
- 238000007254 oxidation reaction Methods 0.000 abstract description 21
- 230000002542 deteriorative effect Effects 0.000 abstract 1
- 238000006722 reduction reaction Methods 0.000 description 53
- 239000007789 gas Substances 0.000 description 9
- 238000000034 method Methods 0.000 description 8
- 239000000843 powder Substances 0.000 description 8
- 230000032798 delamination Effects 0.000 description 7
- 229910052759 nickel Inorganic materials 0.000 description 7
- 239000003985 ceramic capacitor Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000007787 solid Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 239000000919 ceramic Substances 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 229910052698 phosphorus Inorganic materials 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 230000008602 contraction Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- DSSYKIVIOFKYAU-XCBNKYQSSA-N (R)-camphor Chemical compound C1C[C@@]2(C)C(=O)C[C@@H]1C2(C)C DSSYKIVIOFKYAU-XCBNKYQSSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 description 1
- 241000723346 Cinnamomum camphora Species 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229960000846 camphor Drugs 0.000 description 1
- 229930008380 camphor Natural products 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002815 nickel Chemical class 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えば電子部品等
に用いられる導電ペーストフィラーの材料として有用な
ニッケル粉を製造する方法に係り、特に、ニッケル粉の
焼結開始温度を高くしてセラミック誘電体層とのデラミ
ネーションの発生を抑制する技術に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing nickel powder useful as a conductive paste filler material used for, for example, electronic parts and the like, and more particularly to a method for increasing the starting temperature of sintering of nickel powder to obtain a ceramic dielectric. The present invention relates to a technique for suppressing the occurrence of delamination with a body layer.
【０００２】[0002]
【従来の技術】積層セラミックコンデンサは、セラミッ
クのペーストと金属粉末のペーストとを積層し、焼結す
ることによってセラミックの誘電体層と金属の内部電極
層とを交互に形成したものである。ニッケル粉は、従来
のＰｄ粉等に比べて安価なため、特に、粒径が０．１〜
１．０μｍのものが積層セラミックコンデンサの内部電
極形成用として注目されている。2. Description of the Related Art A multilayer ceramic capacitor is formed by laminating a ceramic paste and a metal powder paste and sintering them to alternately form a ceramic dielectric layer and a metal internal electrode layer. Nickel powder is inexpensive as compared with conventional Pd powder and the like.
Ones having a thickness of 1.0 μm have attracted attention for forming internal electrodes of multilayer ceramic capacitors.
【０００３】[0003]
【発明が解決しようとする課題】ところで、ニッケル粉
の焼結開始温度が誘電体層のそれよりも極端に低い場合
には、デラミネーションと呼ばれる欠陥が積層セラミッ
クコンデンサ内に発生する。デラミネーションは、コン
デンサ容量の低下を招くことから好ましくなく、よっ
て、焼結開始温度の高いニッケル粉が要望されている。When the sintering temperature of nickel powder is extremely lower than that of the dielectric layer, a defect called delamination occurs in the multilayer ceramic capacitor. Delamination is not preferable because it causes a decrease in the capacity of the capacitor. Therefore, nickel powder having a high sintering start temperature is demanded.
【０００４】特開平１１−８０８１７号公報および特開
平１１−１２４６０７号公報では、ニッケル粉の焼結開
始温度を高めるために、ニッケル粉の表面にＳやＰを含
有させる技術が開示されている。しかしながら、このよ
うなニッケル粉では、焼結時にＳやＰが誘電体層に拡散
し、誘電体層の電気的特性を劣化させることが懸念され
る。したがって、そのような元素を添加しなくても焼結
開始温度を高くすることができるニッケル粉が強く要望
されていた。Japanese Patent Application Laid-Open Nos. 11-80817 and 11-124607 disclose techniques for increasing the sintering start temperature of nickel powder by adding S and P to the surface of the nickel powder. However, in such nickel powder, there is a concern that S or P diffuses into the dielectric layer during sintering and deteriorates the electrical characteristics of the dielectric layer. Accordingly, there has been a strong demand for a nickel powder that can increase the sintering start temperature without adding such an element.
【０００５】本発明は上記事情に鑑みてなされたもの
で、以下を目的としている。 焼結開始温度の高いニッケル粉の製造方法を提供す
る。 ＳやＰを含有することなく焼結開始温度の高いニッケ
ル粉の製造方法を提供する。 焼結開始温度が高くしかも焼結時の収縮率の小さいニ
ッケル粉の製造方法を提供する。The present invention has been made in view of the above circumstances, and has the following objects. Provided is a method for producing nickel powder having a high sintering start temperature. Provided is a method for producing nickel powder having a high sintering start temperature without containing S or P. Provided is a method for producing nickel powder having a high sintering start temperature and a small shrinkage during sintering.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、ニッケル
粉の焼結挙動に及ぼす水素還元処理の影響について鋭意
研究を重ねた結果、水素還元処理を行うことで焼結開始
温度が上昇することと、収縮率が低下することを見い出
した。特に、ニッケル粉をある程度酸化させた後に水素
還元処理を行うと、焼結開始温度の上昇と収縮率の低下
に一層効果的であることも見い出した。本発明はこのよ
うな知見に基づいてなされたものであり、本発明の第１
のニッケル粉の製造方法は、酸素含有量が０．３〜１．
０重量％のニッケル粉を水素還元処理して酸素含有量を
０．０５〜０．５重量％にすることを特徴としている。
水素還元処理では、ニッケル粉の酸素含有量は少なくと
も０．１重量％、好ましくは０．２重量％低下させるの
が効果的であり、水素還元処理後の酸素含有量は０．０
５〜０．４重量％にするのが好ましい。Means for Solving the Problems The present inventors have conducted intensive studies on the effect of hydrogen reduction treatment on the sintering behavior of nickel powder, and as a result, the hydrogen reduction treatment increases the sintering start temperature. And a decrease in shrinkage. In particular, it has also been found that performing a hydrogen reduction treatment after oxidizing the nickel powder to some extent is more effective in increasing the sintering start temperature and decreasing the shrinkage ratio. The present invention has been made based on such knowledge, and the first aspect of the present invention has been made.
The method for producing nickel powder of the above has an oxygen content of 0.3-1.
The method is characterized in that 0% by weight of nickel powder is subjected to a hydrogen reduction treatment to reduce the oxygen content to 0.05 to 0.5% by weight.
In the hydrogen reduction treatment, it is effective to reduce the oxygen content of the nickel powder by at least 0.1% by weight, preferably 0.2% by weight, and the oxygen content after the hydrogen reduction treatment is 0.0% by weight.
Preferably it is 5 to 0.4% by weight.
【０００７】本発明の第２のニッケル粉の製造方法は、
塩化ニッケル蒸気を水素還元処理して得られた粒径が
０．１〜１．０μｍのニッケル粉を酸化処理した後、次
いで水素還元処理して酸素含有量を０．０５〜０．５重
量％にすることを特徴とし、この発明によっても焼結開
始温度を上昇させ収縮率を低下させることが可能であ
る。[0007] The second method for producing nickel powder of the present invention comprises:
After oxidizing nickel powder having a particle size of 0.1 to 1.0 μm obtained by hydrogen reduction treatment of nickel chloride vapor and then hydrogen reduction treatment to reduce the oxygen content to 0.05 to 0.5% by weight. According to the present invention, the sintering start temperature can be increased and the shrinkage ratio can be reduced.
【０００８】また、本発明のニッケル粉は、焼結開始温
度が５００℃以上、焼結時の収縮率が１０％以下でかつ
酸素含有量が０．１〜０．５重量％であることを特徴と
するもので、このような数値限定によって焼結時のデラ
ミネーションを有効に防止することが可能となる。すな
わち、このようなニッケル粉を積層セラミックコンデン
サの内部電極に用いた場合には、焼結開始温度が５００
℃以上と高温であるため、誘電体の焼結開始温度との差
異が大きくなく、また、収縮率も１０％以下であるた
め、コンデンサを焼成する際のデラミネーションの発生
がかなり抑制される。また、酸素含有量が０．１〜０．
５重量％であるため、還元雰囲気で行われる焼成時の還
元収縮もわずかであり、これもデラミネーションの発生
防止に効果的である。なお、このようなニッケル粉は、
ニッケル粉に酸化処理または水素還元処理を行うこと
で、あるいは両者を組み合わせることで製造することが
できる。以下、本発明の好適な実施の形態について説明
する。The nickel powder of the present invention has a sintering start temperature of 500 ° C. or more, a shrinkage rate of 10% or less during sintering, and an oxygen content of 0.1 to 0.5% by weight. With such a numerical limitation, delamination during sintering can be effectively prevented. That is, when such nickel powder is used for the internal electrode of the multilayer ceramic capacitor, the sintering start temperature is 500
Since the temperature is as high as not less than ° C., the difference from the sintering start temperature of the dielectric is not large, and the shrinkage is not more than 10%, so that the occurrence of delamination when firing the capacitor is considerably suppressed. Further, the oxygen content is 0.1 to 0.1.
Since the content is 5% by weight, reduction shrinkage during firing in a reducing atmosphere is slight, which is also effective in preventing delamination. In addition, such nickel powder,
It can be produced by subjecting nickel powder to oxidation treatment or hydrogen reduction treatment, or a combination of both. Hereinafter, preferred embodiments of the present invention will be described.
【０００９】[0009]
【発明の実施の形態】Ａ．ニッケル粉 Ａ−１．ニッケル粉の生成 ニッケル粉の生成には気相還元方法が採用されるが、原
料ならびに生成法は特に制限されない。具体的には、次
の方法が挙げられる。 固体塩化ニッケルを出発原料とし、この固体塩化ニッ
ケルを加熱蒸発させて発生する塩化ニッケルガスと水素
ガスを反応させる。 固体ニッケルを出発原料とし、この固体ニッケルに塩
素ガスを接触させて塩化ニッケルガスを発生させ、この
塩化ニッケルガスと水素ガスを反応させる。DETAILED DESCRIPTION OF THE INVENTION A. Nickel powder A-1. Formation of Nickel Powder A gas phase reduction method is adopted for the production of nickel powder, but the raw material and the production method are not particularly limited. Specifically, the following method can be used. Using solid nickel chloride as a starting material, nickel chloride gas generated by heating and evaporating the solid nickel chloride is reacted with hydrogen gas. Using solid nickel as a starting material, a chlorine gas is brought into contact with the solid nickel to generate a nickel chloride gas, and the nickel chloride gas and a hydrogen gas are reacted.
【００１０】Ａ−２．ニッケル粉の粒径 ニッケル粉の粒径は、塩化ニッケルガスの水素還元で得
られる通常の範囲内のものでもよいが、高品質のニッケ
ル粉を得るためには０．１〜１．０μｍの範囲が好適で
ある。０．１μｍ未満の微粉が多い場合には、本発明の
水素還元処理を行う際に生じるニッケル粉どうしの焼結
・凝集が進行しすぎるので好ましくなく、その場合に
は、予め微粉を除去しておく方が焼結防止には効果的で
ある。A-2. Particle Size of Nickel Powder The particle size of the nickel powder may be within the usual range obtained by hydrogen reduction of nickel chloride gas, but in order to obtain high quality nickel powder, it is in the range of 0.1 to 1.0 μm. Is preferred. When there are many fine powders of less than 0.1 μm, the sintering and agglomeration of the nickel powders generated during the hydrogen reduction treatment of the present invention are excessively advanced, which is not preferable. In that case, the fine powders are removed in advance. It is more effective to prevent sintering.
【００１１】Ａ−３．ニッケル粉の酸素含有量 固体塩化ニッケルを水素還元して生成したニッケル粉の
酸素含有量は、理論的にはゼロである。しかしながら、
ニッケル粉は、その後に分離、採取、洗浄などの工程を
経て製品化するのが一般的であるため、ある程度の酸化
は避けられない。このため、そのような工程を経たニッ
ケル粉の酸素含有量は、例えば５０〜２０００ｐｐｍ、
またはそれ以上であることもある。ただし、ニッケル粉
の酸素含有量はゼロであっても差し支えない。本発明の
ニッケル粉の製造方法は、水素還元処理前のニッケル粉
が、０．３〜１．０重量％の酸素を含有していることを
前提としており、ニッケル粉の酸素含有量が０．３重量
％以上であれば、そのまま水素還元処理に供することが
できるし、酸素含有量が０．３重量％未満であれば、酸
化処理を行ってから水素還元処理を行えば良い。A-3. Oxygen content of nickel powder The oxygen content of nickel powder produced by hydrogen reduction of solid nickel chloride is theoretically zero. However,
Nickel powder is generally commercialized through processes such as separation, collection, and washing, so that some oxidation is inevitable. Therefore, the oxygen content of the nickel powder having undergone such a process is, for example, 50 to 2000 ppm,
Or even more. However, the oxygen content of the nickel powder may be zero. The method for producing nickel powder of the present invention is based on the premise that the nickel powder before the hydrogen reduction treatment contains 0.3 to 1.0% by weight of oxygen, and the oxygen content of the nickel powder is 0.1% by weight. If it is 3% by weight or more, it can be subjected to the hydrogen reduction treatment as it is. If the oxygen content is less than 0.3% by weight, the hydrogen reduction treatment may be performed after the oxidation treatment.
【００１２】Ｂ．酸化処理 酸化処理については特に限定するものではないが、以下
の態様が好ましい。 Ｂ−１．酸素含有量 ニッケル粉の酸素含有量が０．３〜１．０重量％となる
ように後述する酸化処理条件を適宜設定する。この酸素
含有量が０．３重量％未満では、水素還元処理による焼
結性（焼結開始温度の上昇と収縮率の低下）に及ぼす改
善効果が不充分になるとともに、水素還元処理中のニッ
ケル粉どうしの焼結が生じ易くなる。一方、ニッケル粉
の酸素含有量が１．０重量％を超えると、ニッケル粉の
粒子表面が荒らされてニッケル粉の充填性が低下し、そ
の結果、タップ密度が小さくなって焼結性が低下する。
ニッケル粉の酸素含有量は、０．４〜０．７重量％また
は０．５〜０．９重量％が好ましく、製造過程での水処
理や乾燥工程で既に酸素含有量が０．５重量％以上にな
っている場合には、本発明の製造方法は有効にその効果
を発揮する。 B. Oxidation Treatment The oxidation treatment is not particularly limited, but the following embodiments are preferred. B-1. Oxygen content The oxidation treatment conditions described later are appropriately set so that the oxygen content of the nickel powder is 0.3 to 1.0% by weight. If the oxygen content is less than 0.3% by weight, the effect of improving the sinterability (increase in sintering start temperature and decrease in shrinkage) by the hydrogen reduction treatment will be insufficient, and nickel during the hydrogen reduction treatment will be insufficient. Sintering of the powder is likely to occur. On the other hand, when the oxygen content of the nickel powder exceeds 1.0% by weight, the particle surface of the nickel powder is roughened, and the filling property of the nickel powder is reduced. As a result, the tap density is reduced and the sinterability is reduced. I do.
The oxygen content of the nickel powder is preferably 0.4 to 0.7% by weight or 0.5 to 0.9% by weight, and the oxygen content is already 0.5% by weight in the water treatment or drying step in the production process. In the case described above, the production method of the present invention effectively exerts its effects.
【００１３】Ｂ−２．酸化処理雰囲気 酸化処理の雰囲気は、空気または酸素ガス及び不活性ガ
スの混合ガスとすることができる。あるいは、さらに洗
浄を行ってニッケル粉を酸化させることもできる。B-2. Oxidation treatment atmosphere The oxidation treatment atmosphere can be air or a mixed gas of oxygen gas and inert gas. Alternatively, the nickel powder can be oxidized by further washing.
【００１４】Ｂ−３．酸化温度 上記雰囲気に常温で放置するか、５０〜２００℃の雰囲
気中で加熱する。あるいは、加熱した管の中でニッケル
粉を流通させて加熱することもできる。B-3. Oxidation temperature Leave in the above atmosphere at room temperature or heat in an atmosphere of 50 to 200 ° C. Alternatively, the nickel powder can be heated by flowing nickel powder in a heated tube.
【００１５】Ｂ−４．時間 酸化処理時間は、ニッケル粉の酸素含有量を上記した範
囲とするために必要な時間を適宜設定すれば良い。B-4. Time The oxidation treatment time may be appropriately set to a time necessary for keeping the oxygen content of the nickel powder within the above range.
【００１６】Ｃ．水素還元処理 Ｃ−１．酸素含有量 酸化処理後のニッケル粉に対して引き続き水素還元処理
を行い、水素還元処理後のニッケル粉の酸素含有量が
０．０５〜０．５重量％となるように、後述する水素還
元処理条件を設定する。この場合、水素還元処理前のニ
ッケル粉の酸素含有量が例えば０．４重量％の場合に
は、水素還元処理後の酸素含有量が０．１〜０．３重量
％となるようにする。また、水素還元処理前のニッケル
粉の酸素含有量が０．７重量％の場合には、水素還元処
理後の酸素含有量が０．４重量％あるいはそれ以下とな
るようにする。 C. Hydrogen reduction treatment C-1. Oxygen content A hydrogen reduction treatment is continuously performed on the nickel powder after the oxidation treatment, and a hydrogen reduction treatment described later is performed so that the oxygen content of the nickel powder after the hydrogen reduction treatment is 0.05 to 0.5% by weight. Set conditions. In this case, when the oxygen content of the nickel powder before the hydrogen reduction treatment is, for example, 0.4% by weight, the oxygen content after the hydrogen reduction treatment is set to 0.1 to 0.3% by weight. Further, when the oxygen content of the nickel powder before the hydrogen reduction treatment is 0.7% by weight, the oxygen content after the hydrogen reduction treatment is set to 0.4% by weight or less.
【００１７】Ｃ−１．還元ガス 水素還元処理に用いる還元ガスは、水素ガスもしくは不
活性ガスで希釈された水素ガスが好ましいが、これらに
限定されるものではない。C-1. Reducing Gas The reducing gas used for the hydrogen reduction treatment is preferably hydrogen gas or hydrogen gas diluted with an inert gas, but is not limited thereto.
【００１８】Ｃ−２．還元温度 水素還元処理温度は、２２０〜３００℃が適当である
が、２５０〜３００℃が特に好ましい。水素還元温度が
２００℃以下では還元反応速度が遅く実用的でない。ま
た、水素還元処理温度が３５０℃以上になると、ニッケ
ル粉どうしの焼結が高まる。C-2. Reduction temperature The hydrogen reduction treatment temperature is suitably from 220 to 300 ° C, but particularly preferably from 250 to 300 ° C. When the hydrogen reduction temperature is 200 ° C. or lower, the reduction reaction rate is too slow to be practical. Further, when the hydrogen reduction treatment temperature is 350 ° C. or higher, sintering of nickel powders is increased.
【００１９】Ｃ−３．時間 水素還元処理にかける時間としては、水素還元処理後の
ニッケル粉の酸素含有量を上記した範囲内とするために
必要な時間を適宜設定する。適当な還元時間は、還元温
度にもよるが５〜６０分が良い。C-3. Time As the time required for the hydrogen reduction treatment, a time necessary for keeping the oxygen content of the nickel powder after the hydrogen reduction treatment within the above range is appropriately set. An appropriate reduction time depends on the reduction temperature, but is preferably 5 to 60 minutes.
【００２０】以上のように、本発明では酸化処理後に水
素還元処理を行うのが好ましい態様である。このような
処理を行うことにより、焼結開始温度が上昇するるとと
もに酸素含有量も低下する。また、焼結後の収縮率も低
下し、積層セラミックコンデンサとして好ましい機能を
発揮することができる。これに対して、水素還元処理の
みを行う場合には、焼結開始温度が充分に高くならない
という欠点がある。また、酸化処理のみを行う場合に
は、焼結開始温度は上昇するが酸素含有量も上昇し、内
部電極の品質上好ましくない。さらに、水素還元処理後
に酸化処理を行う場合には、焼結温度は上昇するが、焼
結後の収縮率が上昇するため好ましくない。As described above, in the present invention, it is a preferable embodiment that the hydrogen reduction treatment is performed after the oxidation treatment. By performing such a treatment, the sintering start temperature increases and the oxygen content also decreases. Further, the shrinkage rate after sintering is also reduced, and a preferable function as a multilayer ceramic capacitor can be exhibited. On the other hand, when only the hydrogen reduction treatment is performed, there is a disadvantage that the sintering start temperature does not become sufficiently high. Further, when only the oxidation treatment is performed, the sintering start temperature rises but the oxygen content also rises, which is not preferable in terms of the quality of the internal electrodes. Further, when the oxidation treatment is performed after the hydrogen reduction treatment, the sintering temperature increases, but the shrinkage after sintering increases, which is not preferable.
【００２１】なお、本発明でいう焼結開始温度とは、示
差膨張（Dilatometry）分析で測定された収縮率曲線の
水平部と傾斜部とのそれぞれの接線どうしの交点に対応
する温度をいう。また、収縮率とは、膨張分析で測定さ
れた曲線の安定期に現れる水平部に対応した収縮率の値
をいう。The sintering start temperature referred to in the present invention refers to a temperature corresponding to the intersection of each tangent between the horizontal portion and the inclined portion of the shrinkage rate curve measured by differential expansion analysis. Further, the shrinkage ratio refers to a value of a shrinkage ratio corresponding to a horizontal portion that appears in a stable period of a curve measured by expansion analysis.
【００２２】[0022]
【実施例】以下、本発明をより具体化した実施例を説明
する。塩化ニッケルを１０００℃で水素還元し、粒径が
０．３６μｍ（ＢＥＴ径）で酸素含有量が０．４４重量
％のニッケル粉Ａと、粒径が０．４８μｍ（ＢＥＴ径）
で酸素含有量が０．３７重量％のニッケル粉Ｂを生成し
た。次いで、ニッケル粉Ａおよびニッケル粉Ｂに対し
て、水素還元処理または水素還元処理および酸化処理を
組み合わせた処理を行い、以下の条件で焼結開始温度お
よび収縮率を測定した。なお、酸素含有量は、カーボン
還元して発生するＣＯ／ＣＯ２比から計算される酸素量
をニッケル粉中の酸素含有量とした。Embodiments of the present invention will be described below. Nickel chloride is hydrogen reduced at 1000 ° C., nickel powder A having a particle size of 0.36 μm (BET diameter) and an oxygen content of 0.44% by weight, and a particle size of 0.48 μm (BET diameter)
Produced nickel powder B having an oxygen content of 0.37% by weight. Next, the nickel powder A and the nickel powder B were subjected to hydrogen reduction treatment or a combination of hydrogen reduction treatment and oxidation treatment, and the sintering start temperature and shrinkage were measured under the following conditions. In addition, the oxygen content calculated from the CO / CO 2 ratio generated by carbon reduction was defined as the oxygen content in the nickel powder.
【００２３】・試料原料：ニッケル粉１ｇ＋樟脳３重量
％＋アセトン３重量％ ・試料寸法：試料原料を面圧３ｔｏｎで成形した直径５
ｍｍ、高さ１０ｍｍのペレット ・測定装置：熱膨張収縮挙動測定装置（ＴＤ−５０００
Ｓ、マックサイエンス社製） ・昇温速度：５℃／分 ・雰囲気ガス：窒素ガス ・焼結開始温度：収縮率曲線の水平部と傾斜部のそれぞ
れの接線の交点に対応する温度 ・収縮率：収縮率曲線の末期に安定した収縮率の値Sample raw material: 1 g of nickel powder + 3% by weight of camphor + 3% by weight of acetone Sample size: Diameter 5 of the sample raw material formed at a surface pressure of 3 tonnes
mm, pellet 10 mm in height ・ Measuring device: Thermal expansion / shrinkage behavior measuring device (TD-5000)
S, manufactured by Mac Science) ・ Ramp-up rate: 5 ° C./min ・ Ambient gas: Nitrogen gas ・ Sintering start temperature: Temperature corresponding to the intersection of each tangent of the horizontal part and the inclined part of the shrinkage rate curve ・ Shrinkage rate : The value of the contraction rate that is stable at the end of the contraction rate curve
【００２４】（１）ニッケル粉Ａに対する処理 塩化ニッケルの水素還元で得られたままのニッケル粉Ａ
（未処理品）、このニッケルＡ粉を酸化処理した後に水
素還元処理したもの（実施例１）、ニッケル粉Ａを還元
処理した後に酸化処理したもの（比較例１）、ニッケル
粉Ａに酸化処理したもの（比較例２）のそれぞれの試料
に対して、焼結開始温度、収縮率および処理後の酸素含
有量を測定した。上記の処理条件と測定結果を表１に示
す。(1) Treatment of Nickel Powder A Nickel powder A as obtained by hydrogen reduction of nickel chloride
(Untreated product), a product obtained by subjecting this nickel A powder to oxidation treatment and then hydrogen reduction treatment (Example 1), a product obtained by subjecting nickel powder A to reduction treatment and then oxidation treatment (Comparative Example 1), and an oxidation treatment to nickel powder A The sintering start temperature, the shrinkage ratio, and the oxygen content after the treatment were measured for each of the samples (Comparative Example 2). Table 1 shows the above processing conditions and measurement results.
【００２５】[0025]
【表１】 [Table 1]
【００２６】表１から判るように、実施例１、比較例１
および比較例２のいずれも未処理品と比較して焼結開始
温度の上昇が確認された。しかしながら、収縮率と酸素
含有量のいずれもが低下したのは酸化処理後に水素還元
処理を行った実施例１のみであった。As can be seen from Table 1, Example 1 and Comparative Example 1
In each of Comparative Example 2 and Comparative Example 2, an increase in the sintering start temperature was confirmed as compared with the untreated product. However, only the example 1 in which the hydrogen reduction treatment was performed after the oxidation treatment had a decrease in both the shrinkage and the oxygen content.
【００２７】（２）ニッケル粉Ｂに対する処理 ニッケル粉Ｂの未処理品、ニッケル粉Ｂに２５０℃で３
０分の水素還元処理を行ったものの試料に対して、ニッ
ケル粉Ａと同じ条件で焼結開始温度、収縮率および酸素
含有量を測定した。その結果を表２に示す。(2) Treatment of Nickel Powder B Untreated nickel powder B, 3
The sintering start temperature, shrinkage, and oxygen content of the sample subjected to the hydrogen reduction treatment for 0 minutes were measured under the same conditions as for the nickel powder A. Table 2 shows the results.
【００２８】[0028]
【表２】 [Table 2]
【００２９】ニッケル分Ｂでは水素還元処理の有無で収
縮率の変化は無かったが、焼結開始温度の上昇と酸素含
有量の低下が確認された。以上の実施例により、ニッケ
ル粉に対して水素還元処理または酸化処理および水素還
元処理を行うことにより、ニッケル粉の焼結開始温度が
上昇し、収縮率および酸素含有量が減少するという本発
明の効果が確認された。For the nickel content B, there was no change in the shrinkage rate depending on the presence or absence of the hydrogen reduction treatment, but it was confirmed that the sintering start temperature increased and the oxygen content decreased. According to the above-described embodiment, by performing the hydrogen reduction treatment or the oxidation treatment and the hydrogen reduction treatment on the nickel powder, the sintering start temperature of the nickel powder is increased, and the shrinkage ratio and the oxygen content are reduced. The effect was confirmed.
【００３０】[0030]
【発明の効果】以上説明したように本発明によれば、水
素還元で得たニッケル粉に対し、改めて水素還元処理を
行うことを特徴とするから、焼結開始温度が高く収縮率
および酸素含有量の低い高品質のニッケル粉を得ること
ができ、よって、積層セラミックコンデンサを焼成する
際のデラミネーションの発生を抑制することができると
いう効果を奏する。As described above, according to the present invention, since the nickel powder obtained by hydrogen reduction is subjected to another hydrogen reduction treatment, the sintering start temperature is high and the shrinkage ratio and oxygen content are high. It is possible to obtain a high-quality nickel powder with a small amount, and thus it is possible to suppress the occurrence of delamination when firing the multilayer ceramic capacitor.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 4K017 AA03 BA03 CA08 DA08 EK03 FB06 4K018 BA04 BB04 BC09 BC18 BD04 KA33 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K017 AA03 BA03 CA08 DA08 EK03 FB06 4K018 BA04 BB04 BC09 BC18 BD04 KA33
Claims (5)
ッケル粉を水素還元処理して酸素含有量を０．０５〜
０．５重量％にすることを特徴とするニッケル粉の製造
方法。1. A nickel powder having an oxygen content of 0.3 to 1.0% by weight is subjected to a hydrogen reduction treatment to reduce the oxygen content to 0.05 to 1.0% by weight.
A method for producing nickel powder, comprising 0.5% by weight.
ッケル粉を水素還元処理して酸素含有量を０．０５〜
０．３重量％にすることを特徴とするニッケル粉の製造
方法。2. A nickel powder having an oxygen content of 0.4 to 0.7% by weight is subjected to a hydrogen reduction treatment so that an oxygen content of 0.05 to
A method for producing nickel powder, comprising 0.3% by weight.
ッケル粉を水素還元処理して酸素含有量を０．１〜０．
４重量％にすることを特徴とするニッケル粉の製造方
法。3. A nickel powder having an oxygen content of 0.5 to 0.9% by weight is subjected to hydrogen reduction treatment to reduce the oxygen content to 0.1 to 0.1% by weight.
A method for producing nickel powder, comprising 4% by weight.
られた粒径が０．１〜１．０μｍのニッケル粉を酸化処
理し、次いで水素還元処理して酸素含有量を０．０５〜
０．５重量％にすることを特徴とするニッケル粉の製造
方法。4. A nickel powder having a particle size of 0.1 to 1.0 μm obtained by subjecting nickel chloride vapor to hydrogen reduction treatment is oxidized, and then subjected to hydrogen reduction treatment to reduce the oxygen content to 0.05 to 1.0 μm.
A method for producing nickel powder, comprising 0.5% by weight.
収縮率が１０％以下でかつ酸素含有量が０．１〜０．５
重量％であることを特徴とするニッケル粉。5. A sintering start temperature of 500 ° C. or more, a shrinkage ratio at the time of sintering of 10% or less, and an oxygen content of 0.1 to 0.5.
Nickel powder characterized by weight%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24495399A JP2001073001A (en) | 1999-08-31 | 1999-08-31 | Production of nickel powder and nickel powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24495399A JP2001073001A (en) | 1999-08-31 | 1999-08-31 | Production of nickel powder and nickel powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001073001A true JP2001073001A (en) | 2001-03-21 |
Family
ID=17126421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24495399A Pending JP2001073001A (en) | 1999-08-31 | 1999-08-31 | Production of nickel powder and nickel powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001073001A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017186661A (en) * | 2016-03-31 | 2017-10-12 | Ｄｏｗａエレクトロニクス株式会社 | Silver coated nickel powder and manufacturing method therefor |
-
1999
- 1999-08-31 JP JP24495399A patent/JP2001073001A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2017186661A (en) * | 2016-03-31 | 2017-10-12 | Ｄｏｗａエレクトロニクス株式会社 | Silver coated nickel powder and manufacturing method therefor |
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