JPS6122028B2 - - Google Patents
Info
- Publication number
- JPS6122028B2 JPS6122028B2 JP5151680A JP5151680A JPS6122028B2 JP S6122028 B2 JPS6122028 B2 JP S6122028B2 JP 5151680 A JP5151680 A JP 5151680A JP 5151680 A JP5151680 A JP 5151680A JP S6122028 B2 JPS6122028 B2 JP S6122028B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- copper
- noble metal
- silver
- coating layer
- 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.)
- Expired
Links
- 239000000843 powder Substances 0.000 claims description 43
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 42
- 229910000510 noble metal Inorganic materials 0.000 claims description 37
- 239000011247 coating layer Substances 0.000 claims description 31
- 229910052709 silver Inorganic materials 0.000 claims description 30
- 239000004332 silver Substances 0.000 claims description 30
- 229910052802 copper Inorganic materials 0.000 claims description 26
- 239000010949 copper Substances 0.000 claims description 26
- OAKJQQAXSVQMHS-UHFFFAOYSA-N hydrazine group Chemical group NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 claims description 24
- 150000003839 salts Chemical class 0.000 claims description 21
- 239000000463 material Substances 0.000 claims description 20
- 239000003638 chemical reducing agent Substances 0.000 claims description 16
- 238000003756 stirring Methods 0.000 claims description 16
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical group [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 13
- 229910052737 gold Inorganic materials 0.000 claims description 13
- 239000010931 gold Substances 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 12
- 239000000126 substance Substances 0.000 claims description 11
- 239000007900 aqueous suspension Substances 0.000 claims description 7
- 239000006185 dispersion Substances 0.000 claims description 7
- 150000002500 ions Chemical class 0.000 claims description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 29
- 238000000034 method Methods 0.000 description 19
- 239000000725 suspension Substances 0.000 description 18
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 16
- 229910052751 metal Inorganic materials 0.000 description 15
- 239000002184 metal Substances 0.000 description 15
- 238000000576 coating method Methods 0.000 description 13
- 239000011248 coating agent Substances 0.000 description 12
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 12
- 239000000243 solution Substances 0.000 description 12
- 239000007788 liquid Substances 0.000 description 10
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- 239000000758 substrate Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 6
- 239000003973 paint Substances 0.000 description 6
- 238000007747 plating Methods 0.000 description 6
- 229910001961 silver nitrate Inorganic materials 0.000 description 6
- 239000002904 solvent Substances 0.000 description 6
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 5
- 229910021607 Silver chloride Inorganic materials 0.000 description 5
- 239000002131 composite material Substances 0.000 description 5
- 238000011109 contamination Methods 0.000 description 5
- 229910017604 nitric acid Inorganic materials 0.000 description 5
- 239000010970 precious metal Substances 0.000 description 5
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 5
- 229910052759 nickel Inorganic materials 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- BIVUUOPIAYRCAP-UHFFFAOYSA-N aminoazanium;chloride Chemical compound Cl.NN BIVUUOPIAYRCAP-UHFFFAOYSA-N 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000005388 borosilicate glass Substances 0.000 description 3
- QRJOYPHTNNOAOJ-UHFFFAOYSA-N copper gold Chemical compound [Cu].[Au] QRJOYPHTNNOAOJ-UHFFFAOYSA-N 0.000 description 3
- YCKOAAUKSGOOJH-UHFFFAOYSA-N copper silver Chemical group [Cu].[Ag].[Ag] YCKOAAUKSGOOJH-UHFFFAOYSA-N 0.000 description 3
- 238000011978 dissolution method Methods 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 150000007522 mineralic acids Chemical class 0.000 description 3
- 229910000679 solder Inorganic materials 0.000 description 3
- MTPVUVINMAGMJL-UHFFFAOYSA-N trimethyl(1,1,2,2,2-pentafluoroethyl)silane Chemical compound C[Si](C)(C)C(F)(F)C(F)(F)F MTPVUVINMAGMJL-UHFFFAOYSA-N 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 2
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- NEIHULKJZQTQKJ-UHFFFAOYSA-N [Cu].[Ag] Chemical compound [Cu].[Ag] NEIHULKJZQTQKJ-UHFFFAOYSA-N 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 229910001431 copper ion Inorganic materials 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 229920001296 polysiloxane Polymers 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000007639 printing Methods 0.000 description 2
- 238000011946 reduction process Methods 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical class [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 239000001856 Ethyl cellulose Substances 0.000 description 1
- ZZSNKZQZMQGXPY-UHFFFAOYSA-N Ethyl cellulose Chemical compound CCOCC1OC(OC)C(OCC)C(OCC)C1OC1C(O)C(O)C(OC)C(CO)O1 ZZSNKZQZMQGXPY-UHFFFAOYSA-N 0.000 description 1
- 229910004042 HAuCl4 Inorganic materials 0.000 description 1
- VCUFZILGIRCDQQ-KRWDZBQOSA-N N-[[(5S)-2-oxo-3-(2-oxo-3H-1,3-benzoxazol-6-yl)-1,3-oxazolidin-5-yl]methyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C1O[C@H](CN1C1=CC2=C(NC(O2)=O)C=C1)CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F VCUFZILGIRCDQQ-KRWDZBQOSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- QLEDNNMPZAAWCF-UHFFFAOYSA-N [Cu].[Ag].[Bi] Chemical compound [Cu].[Ag].[Bi] QLEDNNMPZAAWCF-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- JCXGWMGPZLAOME-UHFFFAOYSA-N bismuth atom Chemical compound [Bi] JCXGWMGPZLAOME-UHFFFAOYSA-N 0.000 description 1
- 239000007810 chemical reaction solvent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010908 decantation Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- 229920001249 ethyl cellulose Polymers 0.000 description 1
- 235000019325 ethyl cellulose Nutrition 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 1
- 150000003840 hydrochlorides Chemical class 0.000 description 1
- 229910052809 inorganic oxide Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 1
- MOFOBJHOKRNACT-UHFFFAOYSA-N nickel silver Chemical compound [Ni].[Ag] MOFOBJHOKRNACT-UHFFFAOYSA-N 0.000 description 1
- 239000010956 nickel silver Substances 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 235000011118 potassium hydroxide Nutrition 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Description
【発明の詳細な説明】
本発明は、貴金属が被覆された粉末の製造法に
関するものである。更に詳しくは、本発明は、貴
金属から成る被覆層が基体物質を実用上ほぼ完全
に被覆している粉末を製造する方法に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing noble metal coated powder. More particularly, the present invention relates to a method for producing a powder in which a coating layer of precious metal practically completely covers the substrate material.
金属等の無機物質から成る基体物質の粉末を他
の金属で被覆して得た粉末は各種の組み合せで多
くの用途に使用され又は利用が試みられている。
例えば、導電性ペースト（導電性塗料）、電気接
点等に用いられる金属である金もしくは銀を被覆
層として他の金属等の基体粉末に被覆した系の使
用が試みられている。この系の例としては、金と
タングステン、銀とタングステン、金と炭化チタ
ン、銀と炭化チタン、銅と炭化チタン、金とグラ
フアイト、銀とグラフアイト、銅とグラフアイ
ト、銀と銅、銀と銅・ビスマス複合系等を挙げる
ことができる。また、他の系の例としては、二硫
化モリブデンを基体物質として、この粉末に金も
しくは銀、銅を被覆して得た粉末を固体潤滑材、
高速軸受等の用途に使用する系、銅を基体物質と
して、この粉末に錫もしくはニツケルを被覆して
得た粉末を軸受等に使用する系を挙げることがで
きる。 BACKGROUND ART Powders obtained by coating powders of base materials made of inorganic substances such as metals with other metals have been used or attempted to be used in many applications in various combinations.
For example, attempts have been made to use a system in which a base powder of another metal or the like is coated with gold or silver, which is a metal used for conductive paste (conductive paint), electrical contacts, etc., as a coating layer. Examples of this system are gold and tungsten, silver and tungsten, gold and titanium carbide, silver and titanium carbide, copper and titanium carbide, gold and graphite, silver and graphite, copper and graphite, silver and copper, silver and copper/bismuth composite systems. In addition, as an example of another system, powder obtained by coating molybdenum disulfide with gold, silver, or copper as a base material can be used as a solid lubricant.
Examples include systems used for applications such as high-speed bearings, and systems in which copper is used as a base material and powder obtained by coating this powder with tin or nickel is used for bearings and the like.
このように金属被覆粉末の利用例は各種ある
が、特に被覆層として金、銀、白金等の貴金属を
利用した系は、貴金属の有効利用の面から近年注
目を受けている。例えば特公昭第46−40593号特
許公報に開示されているように、従来は導電材料
として銀を用いている導電性塗料を、銀の代りに
銅−銀複合粉末を用いる利用例、同様に特公昭第
49−21874号特許公報に開示された銅・ビスマス
−銀被覆複合粉末を用いた導電性塗料も考えられ
ている。 As described above, there are various examples of the use of metal-coated powders, but in particular, systems using noble metals such as gold, silver, and platinum as coating layers have received attention in recent years from the standpoint of effective use of noble metals. For example, as disclosed in Japanese Patent Publication No. 46-40593, a conductive paint that conventionally used silver as a conductive material has been replaced with a copper-silver composite powder instead of silver. Koshodai
A conductive paint using a copper-bismuth-silver coated composite powder disclosed in Patent Publication No. 49-21874 is also being considered.
さて、基体物質に、金属から成る被覆層を形成
する方法としては、電気メツキ法、蒸着によるメ
ツキ法、化学メツキ法等が考えられており、特に
化学メツキ法は比較的簡単な装置で工業的規模の
実施が可能であることから、このような化学的方
法の利用は望ましいものである。 Now, as methods for forming a coating layer made of metal on a substrate material, there are electroplating methods, plating methods by vapor deposition, chemical plating methods, etc. The chemical plating method in particular uses relatively simple equipment and is not suitable for industrial use. The use of such chemical methods is desirable because of their scale of implementation.
例えば上述の導電性塗料における銀の使用は、
銀の持つ高度な導電性の利用を基礎とするもので
あるため、導電性塗料により形成される導電面は
実質的に全て銀からなる層で覆われている必要が
ある。即ち、銀と他の金属とからなる複合粉末の
被覆層は実質的に全て銀から構成されていなけれ
ばならず、仮に基体金属が被覆層に入り込み、そ
の被覆層の表面の一部を占めるようになつた場
合、そのような導電層は機能が大幅に低下し、実
用にはなり得ない。このように被覆層を形成する
金属の固有の性能を利用した系で、かつ、その金
属の有効利用を図り、使用量を低減させる目的で
該金属を被覆層とした複合粉末を使用する場合、
その被覆層の純度は高度なものが特に要求され
る。 For example, the use of silver in the conductive paint mentioned above
Since it is based on the use of the highly conductive properties of silver, substantially all of the conductive surface formed by the conductive paint must be covered with a layer of silver. In other words, the coating layer of a composite powder consisting of silver and other metals must be composed essentially entirely of silver, and even if the base metal penetrates into the coating layer and occupies a part of the surface of the coating layer, If this happens, the functionality of such a conductive layer will be significantly reduced and it cannot be put to practical use. In this way, when using a composite powder with a coating layer of the metal in a system that utilizes the unique performance of the metal that forms the coating layer, and in order to effectively utilize the metal and reduce the amount used,
The coating layer is particularly required to have a high degree of purity.
しかしながら、被覆層を形成させるための一般
的な方法である化学メツキ法、例えば、硝酸系で
硝酸銀及びアンモニア水、カセイカリ、砂糖を用
いてその系に分散させた銅粉末上に銀鏡反応を起
させて、銀被覆を形成させる方法では、その被覆
層に、銅粉末からメツキ液中に溶出した銅イオン
が金属銅もしくはその酸化物の形で混入し、被覆
層が汚染される傾向がある。このような銀被覆層
への銅もしくは銅酸化物の混入は、前述したよう
に、特に電気接点、導電性塗料等の用途では実用
上問題となり、特にそのような被覆層への不純物
の混入が一定の割合を超えれば実用に供すること
はできなくなる。 However, the chemical plating method, which is a common method for forming a coating layer, for example, involves causing a silver mirror reaction on copper powder dispersed in a nitric acid system using silver nitrate, aqueous ammonia, caustic potash, and sugar. However, in the method of forming a silver coating, copper ions eluted from the copper powder into the plating solution tend to mix into the coating layer in the form of metallic copper or its oxide, resulting in contamination of the coating layer. As mentioned above, the contamination of such copper or copper oxides into the silver coating layer is a practical problem, especially in applications such as electrical contacts and conductive paints. If it exceeds a certain percentage, it cannot be put to practical use.
本発明者は、化学メツキ法における銅が銅を容
易に溶解する硝酸に銅イオンとして溶解し、これ
が銀から成る被覆層に混入するとの銅混入機構を
防ぐことのできる系から成る被覆法を研究した結
果、銅等の基体物質の溶解が無視できる程度であ
る系に基体物質の粉末を分散させ、かつ、被覆層
を形成する銀等の貴金属の塩がその系で溶解及び
不溶解の二相をなす状態で貴金属塩の還元を行な
うことにより高純度の被覆層を形成する方法を見
出した。即ち本発明は、(A)均一に分散した状態で
存在する被覆層を形成する貴金属の塩、そして(C)
溶解状態で存在する被覆層を形成する貴金属のイ
オン、を含む水系けんだく液に還元剤を撹拌下に
加えることを特徴とする貴金属が被覆された粉末
の製造法（貴金属塩分散法と仮に名付ける）を要
旨とするものである。なお、還元剤を含む溶媒系
に上記のけんだく液を撹拌下加えることも可能で
あるが、この方法は実用上はあまり好ましくな
い。 The present inventor has researched a coating method consisting of a system that can prevent the copper contamination mechanism in which copper is dissolved as copper ions in nitric acid, which easily dissolves copper, and mixed into the coating layer made of silver. As a result, the powder of the base material such as copper is dispersed in a system in which the dissolution of the base material is negligible, and the noble metal salt such as silver that forms the coating layer is dissolved and undissolved in the system. We have discovered a method of forming a highly pure coating layer by reducing the noble metal salt under the conditions. That is, the present invention provides (A) a noble metal salt that forms a coating layer that exists in a uniformly dispersed state, and (C)
A method for producing powder coated with a noble metal (tentatively named noble metal salt dispersion method), which is characterized by adding a reducing agent under stirring to an aqueous suspension containing noble metal ions that form a coating layer in a dissolved state. ). Although it is possible to add the above-mentioned suspension to the solvent system containing the reducing agent while stirring, this method is not very preferred in practice.
また高純度の被覆層は、(A)均一に分散した状態
で存在する基体物質の粉末、そして(B)溶解状態で
存在する被覆層を形成する貴金属のイオン、を含
む水系けんだく液に還元剤の一部を撹拌下に加え
て該水系けんだく液を一旦ゲル状態に変え、次い
で撹拌下に還元剤を更に加えることによりゲル状
態を解き、これにより貴金属が被覆された粉末を
製造する方法（貴金属塩溶解法と仮に名付ける）
によつても得ることができる。 In addition, the high-purity coating layer is reduced to an aqueous suspension containing (A) the powder of the base substance that exists in a uniformly dispersed state, and (B) the noble metal ions that form the coating layer that exist in a dissolved state. A method of producing powder coated with precious metals by adding a portion of the agent under stirring to temporarily transform the aqueous suspension into a gel state, and then adding a reducing agent under stirring to dissolve the gel state. (Tentatively named noble metal salt dissolution method)
It can also be obtained by
本発明で用いる基体物質の例としては、銅、ニ
ツケル、コバルト、鉄等の遷移金属もしくはそれ
らの合金、けい素酸化物、アルミニウム酸化物等
の無機酸化物を挙げることができるが、これらの
物質に限定されるものではない。実用上、好まし
い基体物質は銅及びニツケルであり、特に銅が好
ましい。基体物質の粉末は通常は直径が30μ以下
程度のものが用いられるが、好ましい粉末は直径
10μ以下のものであり、粒度は特に均一である必
要はない。 Examples of the base material used in the present invention include transition metals such as copper, nickel, cobalt, and iron, or alloys thereof, and inorganic oxides such as silicon oxide and aluminum oxide. It is not limited to. In practice, preferred substrate materials are copper and nickel, with copper being particularly preferred. The powder of the base material is usually used with a diameter of about 30μ or less, but the preferred powder is
The particle size is not necessarily 10μ or less, and the particle size does not need to be particularly uniform.
被覆層を形成する貴金属の例としては銀、金及
び白金を挙げることができるが、他の貴金属につ
いても本発明を利用することは可能である。貴金
属の塩としては、使用する溶液系に対して加えた
貴金属塩の一部もしくは全部が溶解する程度の溶
解度を有するものであれば良く、例えば、硝酸
塩、塩酸塩、シアン化物を挙げることができる。
分散した状態で存在する貴金属の温の系を利用す
る方法では、粒子の径に特に制限はないが、一般
には基体物質の粒子の径と同程度、もしくは小さ
い径を有するものが好ましい。 Examples of noble metals forming the coating layer include silver, gold, and platinum, but the present invention can also be applied to other noble metals. The noble metal salt may be any salt having a solubility to the extent that part or all of the added noble metal salt dissolves in the solution system used, and examples thereof include nitrates, hydrochlorides, and cyanides. .
In the method of utilizing a warm system of noble metals existing in a dispersed state, there is no particular restriction on the diameter of the particles, but it is generally preferred that the diameter be the same as or smaller than the diameter of the particles of the base material.
本発明の水系けんだく液は、基体物質を殆んど
溶解せず、かつ、加えた貴金属の塩の一部もしく
は全部を溶解することのできる無機酸を含む系で
あり、溶媒は、水もしくは水と水混和性の有機溶
媒（例、アルコール、アセトン）の混合物が用い
られる。この無機酸としては塩酸もしくは硫酸、
硝酸がある。この無機酸は、基体物質に応じて選
択されるもので、例えば、基体物質として銅もし
くはニツケル用いる場合は塩酸を用いるのが好ま
しく、この場合、硝酸は銅を溶解するので好まし
くない。 The aqueous suspension of the present invention is a system containing an inorganic acid that hardly dissolves the base substance and can dissolve part or all of the noble metal salt added, and the solvent is water or A mixture of water and a water-miscible organic solvent (eg alcohol, acetone) is used. Examples of this inorganic acid include hydrochloric acid or sulfuric acid,
There is nitric acid. This inorganic acid is selected depending on the substrate material. For example, when copper or nickel is used as the substrate material, it is preferable to use hydrochloric acid. In this case, nitric acid is not preferable because it dissolves copper.
本発明で用いる還元剤は、貴金属塩及び貴金属
のイオンを還元することのできる還元剤であれば
特に限定はないが、金属元素を含む無機系の還元
剤を用いた場合、その還元剤が貴金属からなる被
覆層に混入して被覆粉末の実用上の性能を阻害す
ることがあるので、一般には過酸化水素又は有機
系の還元剤を用いることが好ましい。特に好まし
いのはヒドラジンである。 The reducing agent used in the present invention is not particularly limited as long as it is a reducing agent capable of reducing noble metal salts and noble metal ions, but if an inorganic reducing agent containing a metal element is used, the reducing agent may be a noble metal salt. Generally, it is preferable to use hydrogen peroxide or an organic reducing agent, since it may be mixed into the coating layer consisting of the powder and impede the practical performance of the coated powder. Particularly preferred is hydrazine.
本発明における基体物質、貴金属、反応溶媒
系、及び還元剤の組み合わせの代表的な例を次に
記す。 Typical examples of combinations of the substrate material, noble metal, reaction solvent system, and reducing agent in the present invention are described below.
(1) 銅−銀（硝酸銀もしくは塩化銀）−濃塩酸−
ヒドラジン………貴金属塩分散法
(2) 銅−金（HAuCl4）−濃塩酸−ヒドラジン……
…貴金属塩溶解法
(3) ニツケル−銀（硝酸銀もしくは塩化銀）−濃
塩酸−ヒドラジン………貴金属塩分散法
上記の組み合わせの内、(1)の組み合わせによる
被覆粉末の製造（貴金属塩分散法）は、例えば、
次のようにして行なう。(1) Copper - Silver (silver nitrate or silver chloride) - Concentrated hydrochloric acid -
Hydrazine......Precious metal salt dispersion method (2) Copper-gold ( HAuCl4 )-concentrated hydrochloric acid-hydrazine...
...Precious metal salt dissolution method (3) Nickel - silver (silver nitrate or silver chloride) - concentrated hydrochloric acid - hydrazine ......Precious metal salt dispersion method Production of coated powder by combination (1) of the above combinations (noble metal salt dispersion method) ) is, for example,
Do it as follows.
銅粉末は市販のもので良いが市販の銅粉末は、
通常は酸化物の膜に覆われており、そのまま被覆
粉末の製造に供すると、被覆金属との密着度が劣
る傾向があるため、例えば、先ず銅粉末をヒドラ
ジン水溶液に浸漬して銅表面の酸化物を還元し、
清浄な金属銅表面としてから本発明の製造に供す
るのが好ましい。表面を清浄にした銅粉末を濃塩
酸に分散させたけんだく液〔液〕を調製し、こ
れに塩化銀もしくは硝酸銀の微粒子状の結晶粉末
を濃塩酸に投入し、撹拌してその銀塩の一部がイ
オン化して溶解した形にしたけんだく液〔液〕
を撹拌しながら加える。この場合、液は二回に
分けて液に加えるのが好ましい。次いで、得ら
れたけんだく液にヒドラジンを二回程度に分け、
又は少しずつ強く撹拌しながら添加すると、けん
だく液は一旦ゲル状になつた後再度通常のけんだ
く液となり、この時点で銅粉末表面への銀の被覆
は完了する。 Commercially available copper powder is fine, but commercially available copper powder is
Usually, the copper powder is covered with an oxide film, and if it is directly used to produce coated powder, the adhesion to the coated metal tends to be poor. give back things,
It is preferable to provide a clean metallic copper surface before use in the production of the present invention. Prepare a suspension by dispersing surface-cleaned copper powder in concentrated hydrochloric acid, add fine grain crystal powder of silver chloride or silver nitrate to the concentrated hydrochloric acid, and stir to dissolve part of the silver salt. A suspension [liquid] in which parts are ionized and dissolved
Add while stirring. In this case, it is preferable to add the liquid to the liquid in two parts. Next, add hydrazine to the resulting suspension in two portions,
Alternatively, if the suspension is added little by little with strong stirring, the suspension once becomes gel-like and then becomes a normal suspension again, and at this point the silver coating on the surface of the copper powder is completed.
上記のように貴金属塩分散法においても一般に
は還元の過程にてゲル状態を経由するが、貴金属
塩溶解法においては還元の過程にてゲル状態を経
油することが必須の要件となる。即ち、例えば、
上記の貴金属塩分散法と同様にして基体物質のけ
んだく液〔液〕を調製し、これを別に調製した
貴金属塩の溶液〔液〕（実質的に完全に溶解し
ている溶液）と混合する。このようにして得られ
たけんだく液にヒドラジン等の還元剤を撹拌下に
加えて一旦ゲル状態とする。更に還元剤を撹拌下
に加えるとゲル状態が解かれ、通常のけんだく液
に戻る。この時点で基体粉末表面への貴金属の被
覆は完了する。 As mentioned above, in the noble metal salt dispersion method as well, the oil generally passes through a gel state during the reduction process, but in the noble metal salt dissolution method, it is essential to pass through the gel state during the reduction process. That is, for example,
A suspension of the base substance is prepared in the same manner as the noble metal salt dispersion method described above, and this is mixed with a separately prepared noble metal salt solution (a solution in which it is substantially completely dissolved). . A reducing agent such as hydrazine is added to the suspension thus obtained while stirring to temporarily form a gel state. Furthermore, when a reducing agent is added while stirring, the gel state is dissolved and the solution returns to a normal suspension. At this point, coating of the noble metal onto the surface of the base powder is completed.
本発明では前述のように、基体物質が溶媒に殆
んど溶解しない反応系を利用するために、通常の
硝酸を溶媒とした化学メツキ等に見られる銅粉末
の溶媒への溶解を介しての銅の被覆層への混入の
ような基体物質の被覆層への混入が極度に低減す
るため、純度の高い被覆層を有する被覆粉末を得
ることができる。このため被覆金属が貴金属であ
る場合に特に有効であり、またそれらの被覆粉末
は電気接点もしくは導電性ペーストのように、高
純度の被覆層を有する被覆粉末を要求する技術分
野において特に有用である。 As mentioned above, in the present invention, in order to utilize a reaction system in which the base substance is hardly dissolved in the solvent, copper powder is dissolved in the solvent, which is seen in ordinary chemical plating using nitric acid as a solvent. Since the contamination of the base material into the coating layer, such as the contamination of copper into the coating layer, is extremely reduced, a coated powder having a highly pure coating layer can be obtained. This makes them particularly useful when the coating metal is a noble metal, and these coating powders are particularly useful in technical fields that require coating powders with highly pure coating layers, such as electrical contacts or conductive pastes. .
なお、本発明により得ることのできる被覆粉末
を構成する基体物質と貴金属との比は特に限定さ
れないが、実用上有用であるのは基体物質と貴金
属が重量比で１：９から４：６の間にある場合で
ある。 Note that the ratio of the base material to the noble metal constituting the coated powder that can be obtained by the present invention is not particularly limited, but it is practically useful to have a weight ratio of the base material to the noble metal of 1:9 to 4:6. This is a case in between.
本発明を以下に実施例により更に詳しく説明す
るが、これらの実施例は本発明を制限するもので
はない。 The present invention will be explained in more detail with reference to Examples below, but these Examples are not intended to limit the present invention.
実施例 １ 銅−銀系被覆粉末の製造
市販の銅粉末３ｇをヒドラジン水溶液に約１時
間浸漬して表面の酸化膜を還元する。次いで、ヒ
ドラジン水溶液の大部分をデカンテーシヨンによ
り除去して銅粉末上にヒドラジン水溶液がわずか
に残る状態にして、これに100mlの濃塩酸を加え
て撹拌し、銅粉末が均一に分散したけんだく液
〔ａ液〕を調製する。Example 1 Production of Copper-Silver Coated Powder 3 g of commercially available copper powder is immersed in an aqueous hydrazine solution for about 1 hour to reduce the oxide film on the surface. Next, most of the hydrazine aqueous solution was removed by decantation so that a small amount of the hydrazine aqueous solution remained on the copper powder, and 100 ml of concentrated hydrochloric acid was added and stirred to form a suspension in which the copper powder was evenly dispersed. Prepare the liquid [liquid a].
別に、1200mlの濃塩酸に10ｇの硝酸銀（銀とし
ては約６ｇ）を含む50mlの水溶液を加え、撹拌し
て硝酸銀が溶解し塩化銀となり、その塩化銀の一
部が溶解状態にあり他の部分が分散しているけん
だく液〔ａ液〕を調製する。 Separately, add 50 ml of an aqueous solution containing 10 g of silver nitrate (approximately 6 g of silver) to 1,200 ml of concentrated hydrochloric acid, stir, and the silver nitrate dissolves to form silver chloride, with some of the silver chloride remaining in a dissolved state and other parts remaining. Prepare a suspension liquid [liquid A] in which are dispersed.
ａ液にａ液の一部（約50ml）を加えて撹拌
し、銅粉末表面に銀が一部析出して黒変するのを
確認した後、この混合液にａ液の残部を加えて
撹拌を続ける。得られたけんだく液に、まず50ml
のヒドラジン（80％抱水ヒドラジン、以下同じ）
を加えて撹拌を行なうと、けんだく液はゲル状と
なる。このゲル状の液を激しく撹拌して銅粉末を
ほぼ均一に分散させた後、撹拌を続けながら150
mlのヒドラジンを加えると、ゲルは速やかに解消
して同時に銀で被覆された粉末が沈殿する。これ
を過により取り出す。得られた粉末の銀と銅と
の比は重量比で約２：１である。 Add a portion of solution A (approximately 50 ml) to solution A and stir. After confirming that some silver has precipitated on the surface of the copper powder and turned black, add the remainder of solution A to this mixture and stir. Continue. First, add 50ml to the obtained suspension.
of hydrazine (80% hydrazine hydrate, same below)
When added and stirred, the suspension becomes gel-like. After stirring this gel-like liquid vigorously to disperse the copper powder almost uniformly,
ml of hydrazine, the gel rapidly dissolves and at the same time a silver-coated powder precipitates. Remove this by straining. The ratio of silver to copper in the resulting powder is approximately 2:1 by weight.
実施例 ２ 銅−金系被覆粉末の製造
実施例１と同様にして酸化膜を除いた銅粉末３
ｇを濃塩酸250mlと水200mlとからなる溶媒に分散
させて、けんだく液〔ｂ液〕を調製する。Example 2 Production of copper-gold-based coated powder Copper powder 3 from which the oxide film was removed in the same manner as in Example 1
Disperse g in a solvent consisting of 250 ml of concentrated hydrochloric acid and 200 ml of water to prepare a suspension solution [liquid b].
別に、10.8ｇのHAuCl4（金として約6.26ｇ）
を250mlの濃塩酸に加え、撹拌してこの塩が完全
に溶解した溶液〔ｂ液〕を調製する。 Separately, 10.8g HAuCl 4 (approximately 6.26g as gold)
Add the salt to 250 ml of concentrated hydrochloric acid and stir to prepare a solution (liquid B) in which the salt is completely dissolved.
このｂ液にｂ液を、実施例１と同様にして
二度に分けて添加してけんだく液を得る。このけ
んだく液に、まず80mlのヒドラジンを加え撹拌す
るとゲル状態となり、次いで160mlのヒドラジン
を加えて激しく撹拌すると、ゲルは解消し通常の
けんだく液に戻り、同時に金で被覆された粉末が
沈殿する。これを過により取り出す。得られた
粉末の金と銅との比は重量比で約2.1：１であ
る。 Solution b is added to this solution b in two parts in the same manner as in Example 1 to obtain a suspension. First, 80 ml of hydrazine is added to this suspension and stirred, resulting in a gel state.Next, when 160 ml of hydrazine is added and vigorously stirred, the gel dissolves and returns to a normal suspension, at the same time gold-coated powder precipitates. do. Remove this by straining. The gold:copper ratio of the resulting powder is about 2.1:1 by weight.
実施例 ３ 導電性ペーストへの応用例
実施例１で得られた銀−銅系被覆粉末 10ｇ
ホウケイ酸鉛ガラスフリツト 0.2ｇ
エチルセルロース １ｇ
エチルセルソロブ 2.5ｇ
テルピネール 2.5ｇ
上記組成から成る混合物を三本ロール型混練装
置を用いて良く混練してペーストを得る。Example 3 Example of application to conductive paste Silver-copper coated powder obtained in Example 1 10 g Lead borosilicate glass frit 0.2 g Ethyl cellulose 1 g Ethyl Celsorob 2.5 g Terpinel 2.5 g The mixture consisting of the above composition was mixed in a three-roll kneading device. Mix well to obtain a paste.
得られたペーストをスクリーン印刷によりセラ
ミツク基板上に印刷して150℃で30分間乾燥した
後、焼成炉に入れ、この焼成炉の温度を１時間か
けて800℃とした。この800℃の温度を更に10分間
保つた後、得られた印刷板を冷却した。 The resulting paste was printed on a ceramic substrate by screen printing and dried at 150°C for 30 minutes, then placed in a firing furnace, and the temperature of the firing furnace was increased to 800°C over 1 hour. After maintaining this temperature of 800° C. for an additional 10 minutes, the obtained printing plate was cooled.
このようにして得られた金属面（電極）は銀光
沢を有しており、この焼成面を日本電子(株)製の走
査型電子顕微鏡（JSM−25S）を用いて反射電子
像（組成像）を観察したところ、その表面に銅の
存在は認められず、全面が銀で覆われていた。 The metal surface (electrode) obtained in this way has a silver luster, and this fired surface was examined using a backscattered electron image (composition image) using a scanning electron microscope (JSM-25S) manufactured by JEOL Ltd. ), no copper was observed on its surface, and the entire surface was covered with silver.
この焼成面を250℃の半田浴に浸漬したとこ
ろ、金属面の全面に半田が付着した。この半田付
けされた試料の断面をＸ線マイクロアナライザー
（(株)島津製作所製、EMX−SM）で分析したとこ
ろ、電極とセラミツク基板との密着性は良好で、
かつ電極表面と半田との「ぬれ」も良好であつ
た。これらの結果から、電極表面には実用上問題
となる量の銅の露出がないこと、即ち、銀の銅粉
末への被覆が実用上完全であることがわかる。 When this fired surface was immersed in a solder bath at 250°C, solder adhered to the entire surface of the metal surface. When the cross section of this soldered sample was analyzed using an X-ray microanalyzer (EMX-SM, manufactured by Shimadzu Corporation), it was found that the adhesion between the electrode and the ceramic substrate was good.
Moreover, the "wetting" between the electrode surface and the solder was also good. These results show that there is no exposed amount of copper on the electrode surface that would pose a practical problem, that is, the coating of silver on the copper powder is practically complete.
実施例 ４ 導電性ペーストへの応用例
実施例２で得られた金−銅系被覆粉末10ｇとホ
ウケイ酸鉛ガラスフリツト（0.4ｇ）とを、実施
例３の銀−銅系被覆粉末（1.0ｇ）とホウケイ酸
鉛ガラスフリツト（0.2ｇ）の代わりに用いた他
は、実施例３と全く同様にして導電性ペーストを
得て印刷板を作り、走査型電子顕微鏡により同様
にして表面状態を観察したところ、この表面に銅
の存在は認められず、全面が金で覆われていた。Example 4 Example of application to conductive paste 10 g of the gold-copper-based coating powder obtained in Example 2 and lead borosilicate glass frit (0.4 g) were mixed with the silver-copper-based coating powder (1.0 g) of Example 3. A printing plate was prepared using a conductive paste in exactly the same manner as in Example 3, except that lead borosilicate glass frit (0.2 g) was used instead, and the surface condition was observed using a scanning electron microscope in the same manner. , no copper was detected on this surface, and the entire surface was covered with gold.
この焼成面を450℃のホツトプレート上に置
き、この焼成面の上にシリコーン・チツプを載せ
たところ、このシリコーン・チツプは焼成面に良
好に接着した。 When this fired surface was placed on a hot plate at 450° C. and a silicone chip was placed on the fired surface, the silicone chip adhered well to the fired surface.
これらの結果から、電極表面には実用上問題と
なる量の銅の露出がないこと、即ち、金の銅粉末
への被覆が実用上完全であることがわかる。 These results show that there is no exposed amount of copper on the electrode surface that would pose a practical problem, that is, the coverage of gold on the copper powder is practically complete.
Claims (1)
の粉末、 (B) 均一に分散した状態で存在する被覆層を形成
する貴金属の塩、そして (C) 溶解状態で存在する被覆層を形成する貴金属
のイオン、 を含む水系けんだく液に還元剤を撹拌下に加える
ことを特徴とする貴金属が被覆された粉末の製造
法。 ２ 基体物質が銅で、被覆層を形成する貴金属が
金もしくは銀であることを特徴とする特許請求の
範囲第１項記載の製造法。 ３ 還元剤がヒドラジンであることを特徴とする
特許請求の範囲第１項記載の製造法。 ４ 分散液に含まれる基体物質と貴金属との重量
比が１：９から４：６の間にあることを特徴とす
る特許請求の範囲第１項記載の製造法。 ５ (A) 均一に分散した状態で存在する基体物質
の粉末、そして (B) 溶解状態で存在する被覆層を形成する貴金属
のイオン、 を含む水系けんだく液に還元剤の一部を撹拌下に
加えて、該水系けんだく液を一旦ゲル状態に変
え、次いで撹拌下に還元剤を更に加えることによ
りゲル状態を解き、これにより貴金属が被覆され
た粉末を製造する方法。 ６ 還元剤がヒドラジンであることを特徴とする
特許請求の範囲第５項記載の製造方法。[Scope of Claims] 1 (A) a powder of a base material existing in a uniformly dispersed state, (B) a salt of a noble metal forming a coating layer existing in a uniformly dispersed state, and (C) a powder in a dissolved state. A method for producing a powder coated with a noble metal, characterized by adding a reducing agent to an aqueous suspension containing existing noble metal ions forming a coating layer, with stirring. 2. The manufacturing method according to claim 1, wherein the base material is copper and the noble metal forming the coating layer is gold or silver. 3. The manufacturing method according to claim 1, wherein the reducing agent is hydrazine. 4. The manufacturing method according to claim 1, wherein the weight ratio of the base substance and noble metal contained in the dispersion is between 1:9 and 4:6. 5 A portion of the reducing agent is stirred into an aqueous suspension containing (A) powder of the base material existing in a uniformly dispersed state, and (B) ions of the noble metal forming the coating layer existing in a dissolved state. In addition, the aqueous suspension is once turned into a gel state, and then the gel state is dissolved by further adding a reducing agent while stirring, thereby producing a powder coated with a noble metal. 6. The manufacturing method according to claim 5, wherein the reducing agent is hydrazine.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5151680A JPS56150101A (en) | 1980-04-18 | 1980-04-18 | Preparation of powder coated with noble metal |
| US06/251,746 US4450188A (en) | 1980-04-18 | 1981-04-07 | Process for the preparation of precious metal-coated particles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5151680A JPS56150101A (en) | 1980-04-18 | 1980-04-18 | Preparation of powder coated with noble metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56150101A JPS56150101A (en) | 1981-11-20 |
| JPS6122028B2 true JPS6122028B2 (en) | 1986-05-29 |
Family
ID=12889164
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5151680A Granted JPS56150101A (en) | 1980-04-18 | 1980-04-18 | Preparation of powder coated with noble metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56150101A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6092402A (en) * | 1983-10-26 | 1985-05-24 | Tanaka Kikinzoku Kogyo Kk | Manufacture of fine metallic sphere |
| JPS62107073A (en) * | 1985-11-01 | 1987-05-18 | Nippon Chem Ind Co Ltd:The | Production of noble metal plated material |
| JPH0715122B2 (en) * | 1986-02-18 | 1995-02-22 | 三菱マテリアル株式会社 | Co-W coated WC powder and method for producing the same |
| JPH0796681B2 (en) * | 1988-02-04 | 1995-10-18 | 住友金属鉱山株式会社 | Method for producing palladium-coated silver powder |
| EP0725698A4 (en) * | 1993-10-08 | 1999-05-26 | Materials Innovation Inc | Acid assisted cold welding and intermetallic formation and dental applications thereof |
-
1980
- 1980-04-18 JP JP5151680A patent/JPS56150101A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56150101A (en) | 1981-11-20 |
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