JPH04235201A - Method for controlling tap density of powder - Google Patents
Method for controlling tap density of powderInfo
- Publication number
- JPH04235201A JPH04235201A JP3013653A JP1365391A JPH04235201A JP H04235201 A JPH04235201 A JP H04235201A JP 3013653 A JP3013653 A JP 3013653A JP 1365391 A JP1365391 A JP 1365391A JP H04235201 A JPH04235201 A JP H04235201A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- tap density
- stearic acid
- organic solvent
- controlling
- 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
- 239000000843 powder Substances 0.000 title claims abstract description 66
- 238000000034 method Methods 0.000 title claims description 9
- 235000021355 Stearic acid Nutrition 0.000 claims abstract description 29
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 claims abstract description 29
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000008117 stearic acid Substances 0.000 claims abstract description 29
- 239000000203 mixture Substances 0.000 claims abstract description 9
- 239000010409 thin film Substances 0.000 claims abstract description 6
- 239000002904 solvent Substances 0.000 claims abstract description 4
- 239000003960 organic solvent Substances 0.000 claims description 12
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical group CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 10
- 229910045601 alloy Inorganic materials 0.000 claims description 4
- 239000000956 alloy Substances 0.000 claims description 4
- 239000010408 film Substances 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 239000011356 non-aqueous organic solvent Substances 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 2
- 239000008240 homogeneous mixture Substances 0.000 claims 1
- 239000000243 solution Substances 0.000 description 8
- 239000002245 particle Substances 0.000 description 7
- 238000002156 mixing Methods 0.000 description 6
- 239000006185 dispersion Substances 0.000 description 3
- 229910001252 Pd alloy Inorganic materials 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000001746 injection moulding Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- QCMJHCAWPQZNMQ-UHFFFAOYSA-N octadecanoic acid;propan-2-one Chemical compound CC(C)=O.CCCCCCCCCCCCCCCCCC(O)=O QCMJHCAWPQZNMQ-UHFFFAOYSA-N 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Abstract
Description
【０００１】0001
【技術分野】本発明は、所定の粉末のタップ密度を任意
にコントロールして、各種タップ密度の粉末を得る方法
に関するものである。TECHNICAL FIELD The present invention relates to a method of arbitrarily controlling the tap density of a predetermined powder to obtain powders with various tap densities.
【０００２】0002
【背景技術】一般に、各種粉末の製造に際しては、例え
ば導電，抵抗及び絶縁等の各種ペーストを形成するため
の粉末や射出成形用の粉末等の製造において、或いは粉
末冶金等の分野においては、目的とする品質の製品を得
るために、通常、原料粉末のタップ密度（充填時の密度
）が基準とされている。そして、従来から、希望するタ
ップ密度の粉末を得るためには、タップ密度の異なる粉
末を用いて、それらを混合することにより、例えばタッ
プ密度を上げるためには、タップ密度の高い粉末を所定
量混合することにより、コントロールしていた。[Background Art] In general, in the production of various powders, for example, in the production of powders for forming various pastes for conductivity, resistance, insulation, etc., powders for injection molding, etc., or in fields such as powder metallurgy, it is necessary to In order to obtain a product with the desired quality, the tap density (density at the time of filling) of the raw material powder is usually used as a standard. Conventionally, in order to obtain powder with a desired tap density, powders with different tap densities are used, and by mixing them, for example, to increase the tap density, a predetermined amount of powder with a high tap density is used. It was controlled by mixing.
【０００３】しかしながら、このように、タップ密度の
異なる粉末を混合するには、様々なタップ密度の粉末を
用意する必要があり、また、それらタップ密度の異なる
粉末は、それぞれ、平均粒径や粒径の分布、また粒子の
分散状態等が異なるところから、それらを混合して得ら
れた粉末は、粒子の分散状態が不均一であって、粒子径
のバラツキも大きく、再現性に劣り、上記の如き各適用
分野において、実用上好ましいものが得られ難いという
問題を内在していた。However, in order to mix powders with different tap densities in this way, it is necessary to prepare powders with various tap densities, and the powders with different tap densities each have a different average particle size and particle size. Because the size distribution and the dispersion state of the particles are different, the powder obtained by mixing them has a non-uniform dispersion state, large variations in particle size, and poor reproducibility. In each field of application, there is a problem that it is difficult to obtain a practically preferable product.
【０００４】0004
【解決課題】本発明は、このような状況に基づいて為さ
れたものであって、その解決すべき課題とするところは
、粉末粒子の分散性を改善することにより、粒子径等の
大きなバラツキを生じることなく、粉末のタップ密度を
有利にコントロールする方法を提供することにある。[Problem to be solved] The present invention was made based on the above situation, and the problem to be solved is to improve the dispersibility of powder particles, thereby eliminating large variations in particle diameter, etc. It is an object of the present invention to provide a method for advantageously controlling the tap density of powder without causing.
【０００５】[0005]
【解決手段】そして、本発明は、上記の如き課題を解決
するために、粉末の表面を薄い有機物の膜で覆い、その
分散性を改善して、タップ密度をコントロールする方法
において、（ａ）ステアリン酸を非水系有機溶媒中に溶
解せしめ、所定のタップ密度を与えるステアリン酸濃度
とする工程と、（ｂ）かかるステアリン酸の非水系有機
溶媒溶液中に、前記粉末を添加して、均一な混合物と為
す工程と、（ｃ）かくして得られた混合物から、有機溶
媒を蒸発除去せしめて、前記ステアリン酸からなる薄膜
を粉末表面に形成する工程とを含むように、構成したの
である。なお、かかる本発明において、好適には、前記
粉末は、金属若しくは合金粉末であり、また前記ステア
リン酸は、前記粉末に対して０．５重量％以下の割合に
おいて用いられ、更に前記有機溶媒として、一般に、ア
セトンが採用されることとなる。[Solution] In order to solve the above-mentioned problems, the present invention provides a method for controlling tap density by covering the surface of powder with a thin organic film to improve its dispersibility. A step of dissolving stearic acid in a non-aqueous organic solvent to obtain a stearic acid concentration that provides a predetermined tap density, and (b) adding the powder to the stearic acid solution in a non-aqueous organic solvent to form a uniform and (c) evaporating the organic solvent from the mixture thus obtained to form a thin film made of the stearic acid on the surface of the powder. In the present invention, preferably, the powder is a metal or alloy powder, the stearic acid is used in a proportion of 0.5% by weight or less based on the powder, and the organic solvent is preferably , generally acetone will be employed.
【０００６】[0006]
【具体的構成】ところで、かかる本発明にて用いられる
粉末としては、例えば、Ａｕ，Ｐｔ，Ｐｄ，Ａｇ，Ｎｉ
，Ｃｕ等の金属の粉末、若しくはそれら金属からなる合
金粉末が、好適に採用されることとなるが、その他に、
セラミックス粉末等の無機系粉末を採用することも可能
である。[Specific structure] By the way, the powder used in the present invention includes, for example, Au, Pt, Pd, Ag, Ni
Powders of metals such as , Cu, or alloy powders made of these metals are preferably used, but in addition,
It is also possible to employ inorganic powder such as ceramic powder.
【０００７】また、本発明において、上記の如き粉末の
表面に膜を形成するステアリン酸の使用割合としては、
使用する粉末の所期のタップ密度に応じて選定されるこ
ととなるが、適用される粉末の１００重量部に対して、
０．５重量％以下において選定されることが望ましい。
即ち、０．５重量％を越えて使用されても、その効果に
大きな変化が見られず、コスト等の点からも、上記割合
が好適である。Furthermore, in the present invention, the proportion of stearic acid used to form a film on the surface of the powder as described above is as follows:
It will be selected depending on the intended tap density of the powder to be used, but for 100 parts by weight of the powder to be applied,
It is desirable that the content be selected at 0.5% by weight or less. That is, even if it is used in an amount exceeding 0.5% by weight, there is no significant change in the effect, and the above ratio is preferable from the viewpoint of cost and the like.
【０００８】さらに、かかるステアリン酸が溶解せしめ
られる有機溶媒としては、特にケトン類、なかでもアセ
トンが好適に用いられるが、非水系にてステアリン酸が
溶解され得る低沸点溶媒であれば、公知の何れもが採用
され得、特に限定されるものではない。Furthermore, as the organic solvent in which stearic acid is dissolved, ketones, especially acetone, are preferably used, but any known low-boiling solvent in which stearic acid can be dissolved in a non-aqueous system can be used. Any one can be adopted, and there is no particular limitation.
【０００９】そして、本発明にあっては、先ず、予め求
められたステアリン酸濃度とタップ密度との関係から、
所定のタップ密度に相当するステアリン酸濃度となるよ
うに、ステアリン酸の所定量を、アセトン等の有機溶媒
中に非水系において溶解せしめ、所定濃度のステアリン
酸の有機溶媒溶液が調製されるのである。In the present invention, first, from the relationship between the stearic acid concentration and the tap density determined in advance,
A predetermined amount of stearic acid is dissolved in an organic solvent such as acetone in a non-aqueous system so that the stearic acid concentration corresponds to a predetermined tap density, thereby preparing an organic solvent solution of stearic acid with a predetermined concentration. .
【００１０】次いで、かかる溶液中に、上記の如き粉末
の所定量を添加し、通常の手法に従って、均一に撹拌，
混合した後、この混合物を、放置、或いは必要に応じて
加熱せしめることにより、かかる混合物から有機溶媒成
分を蒸発せしめて除去し、充分に乾燥せしめる。なお、
ステアリン酸の有機溶媒溶液と粉末との混合割合は、特
に限定されるものではなく、粉末全体が充分に浸漬せし
められる程度であれば良い。また、上記混合物において
、粉末に比して、ステアリン酸有機溶媒溶液の容量が著
しく多い場合には、有機溶媒を蒸発除去させるに先立っ
て、必要に応じて、濾過等によって、該混合物から有機
溶媒溶液の余剰分を除去せしめたりすることも可能であ
る。[0010] Next, a predetermined amount of the powder as described above is added to the solution, and the mixture is uniformly stirred and stirred according to a conventional method.
After mixing, the mixture is allowed to stand or is heated as necessary to evaporate and remove the organic solvent component from the mixture, and the mixture is thoroughly dried. In addition,
The mixing ratio of the organic solvent solution of stearic acid and the powder is not particularly limited, as long as the entire powder is sufficiently immersed. In addition, in the above mixture, if the volume of the stearic acid organic solvent solution is significantly larger than that of the powder, the organic solvent may be removed from the mixture by filtration, etc., if necessary, before the organic solvent is evaporated and removed. It is also possible to remove excess solution.
【００１１】かくして、その表面にステアリン酸の薄膜
が均一に形成されてなり、所定のタップ密度を有する粉
末が得られるのであり、かかる粉末は、ステアリン酸の
薄膜が表面に形成されているところから、粉末表面への
水分の付着が効果的に阻止され得、以てロット内の粒子
の分散状態や凝集状態が均一となるのである。このよう
に、本発明に従えば、従来の如くタップ密度の異なる粉
末を混合する必要がなく、ステアリン酸の濃度を変化さ
せることにより、容易にタップ密度をコントロールする
ことが出来るところから、粒子径やその分布状態等のバ
ラツキの改善された粉末が効果的に得られるのである。[0011] In this way, a powder is obtained in which a thin film of stearic acid is uniformly formed on the surface and has a predetermined tap density. The adhesion of moisture to the powder surface can be effectively prevented, thereby making the dispersion and agglomeration state of particles within a lot uniform. As described above, according to the present invention, there is no need to mix powders with different tap densities as in the past, and the tap density can be easily controlled by changing the concentration of stearic acid. Powder with improved variation in its distribution state, etc. can be effectively obtained.
【００１２】0012
【実施例】以下に、本発明の実施例を示し、本発明を更
に具体的に明らかにすることとするが、本発明がそのよ
うな実施例の記載によって何等の制約をも受けるもので
ないことは、言うまでもないところである。また、本発
明には、以下の実施例の他にも、更には上述の具体的説
明以外にも、本発明の趣旨を逸脱しない限りにおいて、
当業者の知識に基づいて種々なる変更、修正、改良等を
加え得るものであることが、理解されるべきである。[Examples] Examples of the present invention are shown below to clarify the present invention more specifically, but the present invention is not limited in any way by the description of such examples. It goes without saying that. In addition to the following examples and the above-mentioned specific explanation, the present invention includes other examples as long as they do not depart from the spirit of the present invention.
It should be understood that various changes, modifications, improvements, etc. can be made based on the knowledge of those skilled in the art.
【００１３】先ず、Ａｇ−Ｐｄ合金粉末（ＡＡＰ５６１
４２３，ＡＡＰ３０２６１０またはＡＡＰ３０２ＦＦＦ
）の各１００ｇを、該粉末の１００ｇに対して、ステア
リン酸の濃度がそれぞれ０．００５％（Ｎｏ． １）、
０．０３％（Ｎｏ． ２）、０．０５％（Ｎｏ． ３）
、０．１％（Ｎｏ． ４）であるステアリン酸アセトン
溶液の各６０ｍｌに、それぞれ添加した。そして、２０
分の撹拌，混合の後、アセトンを蒸発せしめて、粉末を
充分に乾燥させた。かくして、ステアリン酸の薄膜によ
り表面が覆われた各粉末を得、そしてそれぞれのタップ
密度を測定し、その結果を図１に示した。なお、比較の
ために、表面にステアリン酸の薄膜が形成されていない
粉末（Ｎｏ． ５）についても、同様に、タップ密度を
測定し、図１に併わせ示した。First, Ag-Pd alloy powder (AAP561
423, AAP302610 or AAP302FFF
), the concentration of stearic acid is 0.005% (No. 1),
0.03% (No. 2), 0.05% (No. 3)
, 0.1% (No. 4) stearic acid acetone solution. And 20
After stirring and mixing for several minutes, the acetone was evaporated and the powder was thoroughly dried. In this way, each powder whose surface was covered with a thin film of stearic acid was obtained, and the tap density of each powder was measured, and the results are shown in FIG. For comparison, the tap density of a powder (No. 5) on which a thin stearic acid film was not formed was also measured and shown in FIG. 1.
【００１４】なお、かかるタップ密度は、以下の如き方
法を採用して、測定した。先ず、試料としてＡｇ−Ｐｄ
合金粉末の約５ｍｌを正確に秤量し、これをメスシリン
ダーにロートを用いて投入した。次いで、落差距離：２
５ｍｍ、速度：１回／秒において、１００回のタッピン
グを行ない、圧縮されたＡｇ−Ｐｄ合金粉末の容積を測
定し、下式に従って、タップ密度を算出した。
タップ密度（ｇ／ｃｍ３ ）＝試料質量（ｇ）
÷試料容積（ｃｍ３ ）The tap density was measured using the following method. First, Ag-Pd was used as a sample.
Approximately 5 ml of the alloy powder was accurately weighed and poured into a graduated cylinder using a funnel. Next, head distance: 2
Tapping was performed 100 times at a speed of 5 mm and a speed of 1 time/second, the volume of the compressed Ag-Pd alloy powder was measured, and the tap density was calculated according to the following formula. Tap density (g/cm3) = sample mass (g)
÷Sample volume (cm3)
【００１５】かかる図１から明
らかなように、本発明に従って、ステアリン酸の濃度を
変化させることにより、各種のタップ密度の粉末が得ら
れることが分かった。As is clear from FIG. 1, it has been found that powders with various tap densities can be obtained by varying the concentration of stearic acid according to the present invention.
【００１６】[0016]
【発明の効果】以上の説明から明らかなように、本発明
に従えば、粉末の用途に従って要求される各種のタップ
密度がステアリン酸の濃度に応じて実現され得、以てタ
ップ密度が有利にコントロールされ得ることとなったの
であり、また従来の如く、異なるタップ密度の粉末を混
合せしめて、目的とする粉末を得る必要がないところか
ら、粉末の粒子径や分散状態のバラツキの小さい、実用
上有効な粉末が容易に得られるのである。Effects of the Invention As is clear from the above explanation, according to the present invention, various tap densities required according to the use of the powder can be achieved depending on the concentration of stearic acid, and thus the tap density can be advantageously adjusted. In addition, there is no need to mix powders with different tap densities to obtain the desired powder, as was the case in the past. Furthermore, effective powders can be easily obtained.
【図１】実施例にて得られたステアリン酸濃度と粉末の
タップ密度との関係を示すグラフである。FIG. 1 is a graph showing the relationship between stearic acid concentration and powder tap density obtained in Examples.
Claims (4)
その分散性を改善して、タップ密度をコントロールする
方法にして、ステアリン酸を非水系有機溶媒中に溶解せ
しめ、所定のタップ密度を与えるステアリン酸濃度とす
る工程と、かかるステアリン酸の非水系有機溶媒溶液中
に、前記粉末を添加して、均一な混合物と為す工程と、
かくして得られた混合物から、有機溶媒を蒸発除去せし
めて、前記ステアリン酸からなる薄膜を粉末表面に形成
する工程とを、含むことを特徴とする粉末のタップ密度
コントロール方法。[Claim 1] Covering the surface of the powder with a thin organic film,
A step of dissolving stearic acid in a non-aqueous organic solvent to obtain a stearic acid concentration that provides a predetermined tap density by improving its dispersibility and controlling the tap density; adding the powder into a solvent solution to form a homogeneous mixture;
A method for controlling the tap density of powder, comprising the step of evaporating the organic solvent from the mixture thus obtained and forming a thin film made of the stearic acid on the surface of the powder.
ある請求項１記載の粉末のタップ密度コントロール方法
。2. The powder tap density control method according to claim 1, wherein the powder is a metal or alloy powder.
て０．５重量％以下の割合において用いられる請求項１
または２記載の粉末のタップ密度コントロール方法。3. Claim 1, wherein the stearic acid is used in a proportion of 0.5% by weight or less based on the powder.
Or the powder tap density control method described in 2.
項１乃至３の何れかに記載の粉末のタップ密度コントロ
ール方法。4. The method for controlling the tap density of powder according to claim 1, wherein the organic solvent is acetone.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3013653A JPH04235201A (en) | 1991-01-10 | 1991-01-10 | Method for controlling tap density of powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3013653A JPH04235201A (en) | 1991-01-10 | 1991-01-10 | Method for controlling tap density of powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04235201A true JPH04235201A (en) | 1992-08-24 |
Family
ID=11839182
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3013653A Pending JPH04235201A (en) | 1991-01-10 | 1991-01-10 | Method for controlling tap density of powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04235201A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000048644A (en) * | 1998-07-24 | 2000-02-18 | Murata Mfg Co Ltd | Inorganic powder and its manufacture |
| JP2007314852A (en) * | 2006-05-29 | 2007-12-06 | Fukuda Metal Foil & Powder Co Ltd | Silver powder and production method therefor |
| JP2007332391A (en) * | 2006-06-12 | 2007-12-27 | Fukuda Metal Foil & Powder Co Ltd | Copper powder and its production method |
| US7527752B2 (en) | 2004-11-24 | 2009-05-05 | Samsung Electro-Mechanics Co., Ltd. | Method for surface treatment of nickel nanoparticles with organic solution |
-
1991
- 1991-01-10 JP JP3013653A patent/JPH04235201A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000048644A (en) * | 1998-07-24 | 2000-02-18 | Murata Mfg Co Ltd | Inorganic powder and its manufacture |
| US7527752B2 (en) | 2004-11-24 | 2009-05-05 | Samsung Electro-Mechanics Co., Ltd. | Method for surface treatment of nickel nanoparticles with organic solution |
| JP2007314852A (en) * | 2006-05-29 | 2007-12-06 | Fukuda Metal Foil & Powder Co Ltd | Silver powder and production method therefor |
| JP2007332391A (en) * | 2006-06-12 | 2007-12-27 | Fukuda Metal Foil & Powder Co Ltd | Copper powder and its production method |
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