JPS63307208A - Production of fine noble metal powder - Google Patents
Production of fine noble metal powderInfo
- Publication number
- JPS63307208A JPS63307208A JP14297887A JP14297887A JPS63307208A JP S63307208 A JPS63307208 A JP S63307208A JP 14297887 A JP14297887 A JP 14297887A JP 14297887 A JP14297887 A JP 14297887A JP S63307208 A JPS63307208 A JP S63307208A
- Authority
- JP
- Japan
- Prior art keywords
- noble metal
- sol
- particles
- liquid
- 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.)
- Pending
Links
- 229910000510 noble metal Inorganic materials 0.000 title claims abstract description 83
- 239000000843 powder Substances 0.000 title claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 239000002245 particle Substances 0.000 claims abstract description 70
- 150000003839 salts Chemical class 0.000 claims abstract description 29
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 15
- 238000009826 distribution Methods 0.000 claims abstract description 12
- 239000007864 aqueous solution Substances 0.000 claims description 20
- 239000002994 raw material Substances 0.000 claims description 15
- 239000013078 crystal Substances 0.000 abstract description 16
- 230000002378 acidificating effect Effects 0.000 abstract description 8
- 239000007858 starting material Substances 0.000 abstract 2
- 239000007788 liquid Substances 0.000 description 41
- 239000000243 solution Substances 0.000 description 26
- 238000000034 method Methods 0.000 description 14
- 239000002253 acid Substances 0.000 description 12
- 239000010970 precious metal Substances 0.000 description 11
- 239000010419 fine particle Substances 0.000 description 9
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 8
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 8
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 7
- 229910052709 silver Inorganic materials 0.000 description 7
- 239000004332 silver Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- 239000008367 deionised water Substances 0.000 description 6
- 229910021641 deionized water Inorganic materials 0.000 description 6
- 239000003513 alkali Substances 0.000 description 5
- 239000000084 colloidal system Substances 0.000 description 5
- 239000002923 metal particle Substances 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000008139 complexing agent Substances 0.000 description 4
- 229910001961 silver nitrate Inorganic materials 0.000 description 4
- 108010010803 Gelatin Proteins 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 229920000159 gelatin Polymers 0.000 description 3
- 239000008273 gelatin Substances 0.000 description 3
- 235000019322 gelatine Nutrition 0.000 description 3
- 235000011852 gelatine desserts Nutrition 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- -1 inorganic acid salt Chemical class 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 230000006911 nucleation Effects 0.000 description 3
- 238000010899 nucleation Methods 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 239000003223 protective agent Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 150000007529 inorganic bases Chemical class 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 239000011859 microparticle Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 150000007530 organic bases Chemical class 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 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 2
- TUSDEZXZIZRFGC-UHFFFAOYSA-N 1-O-galloyl-3,6-(R)-HHDP-beta-D-glucose Natural products OC1C(O2)COC(=O)C3=CC(O)=C(O)C(O)=C3C3=C(O)C(O)=C(O)C=C3C(=O)OC1C(O)C2OC(=O)C1=CC(O)=C(O)C(O)=C1 TUSDEZXZIZRFGC-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 102000011632 Caseins Human genes 0.000 description 1
- 108010076119 Caseins Proteins 0.000 description 1
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 1
- 239000001263 FEMA 3042 Substances 0.000 description 1
- 229910001111 Fine metal Inorganic materials 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- LRBQNJMCXXYXIU-PPKXGCFTSA-N Penta-digallate-beta-D-glucose Natural products OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@@H]2[C@H]([C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-PPKXGCFTSA-N 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 150000008043 acidic salts Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 239000012736 aqueous medium Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- LRBQNJMCXXYXIU-QWKBTXIPSA-N gallotannic acid Chemical compound OC1=C(O)C(O)=CC(C(=O)OC=2C(=C(O)C=C(C=2)C(=O)OC[C@H]2[C@@H]([C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)[C@@H](OC(=O)C=3C=C(OC(=O)C=4C=C(O)C(O)=C(O)C=4)C(O)=C(O)C=3)O2)OC(=O)C=2C=C(OC(=O)C=3C=C(O)C(O)=C(O)C=3)C(O)=C(O)C=2)O)=C1 LRBQNJMCXXYXIU-QWKBTXIPSA-N 0.000 description 1
- 150000003840 hydrochlorides Chemical class 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 150000003057 platinum Chemical class 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 229940080237 sodium caseinate Drugs 0.000 description 1
- SDKPSXWGRWWLKR-UHFFFAOYSA-M sodium;9,10-dioxoanthracene-1-sulfonate Chemical compound [Na+].O=C1C2=CC=CC=C2C(=O)C2=C1C=CC=C2S(=O)(=O)[O-] SDKPSXWGRWWLKR-UHFFFAOYSA-M 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000010301 surface-oxidation reaction Methods 0.000 description 1
- 229940033123 tannic acid Drugs 0.000 description 1
- 235000015523 tannic acid Nutrition 0.000 description 1
- 229920002258 tannic acid Polymers 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/0004—Preparation of sols
- B01J13/0043—Preparation of sols containing elemental metal
Abstract
Description
【発明の詳細な説明】
〔技術分野〕
本発明は、貴金属塩の還元工程を含む貴金属微粉末の製
造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing fine noble metal powder, which includes a step of reducing a noble metal salt.
貴金属微粉末の製造法としては、種々の方法が知られて
いるが、その中でも貴金属塩の水溶液を還元して貴金属
微粉末を得る湿式法（特開昭５５−７６００３号公報、
特開昭５４−１２１２７０号公報、特公昭４８−４２７
８２号公報等）は最も安価なため広く用いられている。Various methods are known for producing fine precious metal powder, among which there is a wet method for obtaining fine precious metal powder by reducing an aqueous solution of a noble metal salt (Japanese Unexamined Patent Application Publication No. 76003/1989,
Japanese Unexamined Patent Publication No. 54-121270, Japanese Patent Publication No. 48-427
No. 82, etc.) is widely used because it is the cheapest.
しかしながら、従来の湿式法は、貴金属塩の還元時に、
核発生と結晶成長を同時に行なわせるため、生成する貴
金属粒子の粒度分布が広くなり、又、平均粒径の制御も
難かしいという欠点があった。However, in the conventional wet method, when reducing the noble metal salt,
Since nucleation and crystal growth are performed simultaneously, the particle size distribution of the noble metal particles produced is wide, and the average particle size is also difficult to control.
貴金属微粉末は導電性塗料用フィラー等として用いられ
るが、このような用途においては、貴金属微粉末の粒径
あるいは粒度分布を特定範囲に規定することが要求され
る。従って、貴金属微粉末の製造技術としては、粒度分
布をできるだけシャープにして、その平均粒径を再現性
良く制御する技術が望まれるわけであるが、前記したよ
うに、従来の貴金属塩水溶液を還元する湿式法は、この
粒度分布の制御の点では満足し得るものではなかった・
〔目 的〕
本発明は、前記湿式法による貴金属微粉末の製造技術に
見られる欠点を克服し、シャープな粒度分布を有する貴
金属微粉末を製造する方法を提供することを目的とする
。Fine metal powders are used as fillers for conductive paints, etc., but in such applications, it is required that the particle size or particle size distribution of the fine noble metal powders be defined within a specific range. Therefore, as a manufacturing technology for precious metal fine powder, a technology that makes the particle size distribution as sharp as possible and controls the average particle size with good reproducibility is desired. The wet method for producing noble metal fine powder was not satisfactory in terms of controlling the particle size distribution. [Objective] The present invention overcomes the drawbacks of the wet method for manufacturing precious metal fine powder, and produces a fine powder with a sharp particle size. It is an object of the present invention to provide a method for manufacturing noble metal fine powder having a distribution.
本発明によれば、貴金属塩水溶液を還元して貴金属微粉
末を得るにあたり、
（ｉ）該貴金属塩水溶液を還元して原料貴金属ゾルを形
成する工程、
（…）該原料貴金属ゾルに、貴金属塩を含む酸性水溶液
と、還元剤を含むアルカリ性水溶液とを少なくとも１回
交互に添加して、該貴金属ゾル粒子を成長させる工程、
からなることを特徴とする粒度分布の均一化された貴金
属微粉末の製造方法が提供される。According to the present invention, in reducing a noble metal salt aqueous solution to obtain a noble metal fine powder, (i) reducing the noble metal salt aqueous solution to form a raw material noble metal sol; (...) adding a noble metal salt to the raw material noble metal sol; A step of growing the precious metal sol particles by alternately adding at least once an acidic aqueous solution containing a reducing agent and an alkaline aqueous solution containing a reducing agent. A manufacturing method is provided.
本発明において用いられる貴金属塩は、水溶性のもので
あればよく、有機塩酸、無機酸塩を問わず使用可能であ
るが、一般的には、硝酸塩、塩酸塩等を挙げることがで
きる。また、本発明における貴金属塩には錯塩も含まれ
る。本発明における貴金属としては、周期律表第１．族
の銀（Ａｇ）、金（Ａｕ）、第■族の白金（Ｐｔ）、パ
ラジウム（Ｐｄ）等を挙げることができる。The noble metal salt used in the present invention only needs to be water-soluble, and can be used regardless of whether it is an organic hydrochloric acid or an inorganic acid salt. Generally, nitrates, hydrochlorides, etc. can be mentioned. Moreover, the noble metal salt in the present invention also includes a complex salt. The noble metals used in the present invention include those listed in No. 1 of the periodic table. Examples include silver (Ag) and gold (Au) of the group II, platinum (Pt) and palladium (Pd) of the group I.
本発明の方法は、貴金属ゾル形成工程と貴金属ゾル粒子
の成長化工程を含むものであるが、以下、これらの工程
について詳述する。The method of the present invention includes a step of forming a noble metal sol and a step of growing noble metal sol particles, and these steps will be described in detail below.
この工程は、貴金属塩の水溶液を還元して原料貴金属ゾ
ル（以下、単に原料ゾルとも言う）を製造する工程であ
る。この貴金属ゾルの形成工程は、従来公知の方法に従
って実施することができる。This step is a step of reducing an aqueous solution of a noble metal salt to produce a raw material noble metal sol (hereinafter also simply referred to as raw material sol). This step of forming a noble metal sol can be carried out according to a conventionally known method.
この場合、貴金属ゾル粒子（以下、単にゾル粒子とも言
う）の粒径は、その調製方法により広範囲に調節可能で
あるが、通常Ｌｏｏｍμ以下、好ましくは約２０〜８０
ｍμである。安定性の良い原料ゾルを得るには、錯化剤
又は／及びコロイド保護剤を添加するのが好ましい。錯
化剤としては、水酸基を含む多価カルボン酸、ＥＤＴＡ
等がある。又、コロイド保護剤としては、慣用の水溶性
高分子１例えば、ゼラチン、カゼイン酸ナトリウム、ポ
リビニルビロリドン、ポリアクリル酸ヒドラジド、ポリ
−Ｎ−ビニル−５−メトキシゾリドン等を用いることが
できる。錯化剤及びコロイド保護剤は、夫々単独又は混
合物で用いてもよく、又、錯化剤とコロイド保護剤とを
混合して用いてもよい。貴金属水溶液中の貴金属濃度は
、一般的には溶液１ρ当り、貴金属０．２モル以下、好
ましくは０．０５〜０．１モルの割合にするのがよい、
、還元剤としては、例えば、ホルマリン、ヒドラジンの
ような強い還元力を有する物質でも、シュウ酸、タンニ
ン酸、メタノール等の弱い還元剤でも使用することがで
き、貴金属塩の種類に応じて適当に選定すればよい。還
元反応温度は室温あるいは８０℃程度までの加温が採用
される。In this case, the particle size of the noble metal sol particles (hereinafter also simply referred to as sol particles) can be adjusted over a wide range depending on the preparation method, but is usually less than Loomμ, preferably about 20 to 80 μm.
It is mμ. In order to obtain a raw material sol with good stability, it is preferable to add a complexing agent and/or a colloid protectant. As a complexing agent, polyhydric carboxylic acid containing a hydroxyl group, EDTA
etc. Further, as the colloid protective agent, conventional water-soluble polymers 1 such as gelatin, sodium caseinate, polyvinylpyrrolidone, polyacrylic acid hydrazide, poly-N-vinyl-5-methoxyzolidone, etc. can be used. . The complexing agent and the colloid protecting agent may be used alone or as a mixture, or the complexing agent and the colloid protecting agent may be used as a mixture. The concentration of the precious metal in the noble metal aqueous solution is generally 0.2 mol or less of the precious metal, preferably 0.05 to 0.1 mol, per 1 ρ of the solution.
As the reducing agent, for example, substances with strong reducing power such as formalin and hydrazine, or weak reducing agents such as oxalic acid, tannic acid, and methanol can be used. Just choose. The reduction reaction temperature is room temperature or heating to about 80°C.
本発明において、貴金属塩として銀塩を用いる場合、そ
の銀塩としては硝酸塩の使用が好ましく、その水溶液中
の銀濃度は、金属銀換算で２．０重量％以下、好ましく
は０．５〜１．０重量％にするのがよく、金塩や白金塩
を用いる場合、その塩としては塩化金酸（ＨＡｕＣＱ
）や塩化白金酸（ＨＰｔＣＱ 、）等を使用するのが好
ましく、その水溶液中濃度は、金属金又は白金換算で４
．０重量％以下、好ましくは１〜２重量％にするのがよ
い。In the present invention, when a silver salt is used as the noble metal salt, it is preferable to use a nitrate as the silver salt, and the silver concentration in the aqueous solution is 2.0% by weight or less in terms of metallic silver, preferably 0.5 to 1. 0% by weight, and when using gold salt or platinum salt, the salt should be chloroauric acid (HAuCQ).
), chloroplatinic acid (HPtCQ, ), etc. are preferably used, and the concentration in the aqueous solution is 4% in terms of metallic gold or platinum.
．． The content is preferably 0% by weight or less, preferably 1 to 2% by weight.
貴金属ゾル粒子の粒径は、貴金属塩水溶液中の貴金属濃
度や、コロイドを安定化するための各種添加物の量等に
よって調節することができる。The particle size of the noble metal sol particles can be adjusted by the concentration of the noble metal in the noble metal salt aqueous solution, the amount of various additives for stabilizing the colloid, and the like.
なお、本明細書中でいう貴金属ゾルとは、貴金属微粒子
が水性媒体中に分散している液体系を意味し、貴金属ゾ
ル粒子とは、その液体系（ゾル）中に分散している貴金
属微粒子を意味するものである。In this specification, the term "noble metal sol" refers to a liquid system in which noble metal fine particles are dispersed in an aqueous medium, and the term "noble metal sol particles" refers to noble metal fine particles dispersed in the liquid system (sol). It means.
前記のようにして得られる原料貴金属ゾル中に含まれる
ゾル粒子は、そのままでは粒径が非常に小さく凝集して
いないために分離が困難であり、また超遠心分離等の方
法で仮に分離しても、表面エネルギーが大きいために不
安定で、その後の熱処理により貴金属粒子とする際に、
凝結したり、表面酸化等を起して低品質の貴金属粒子を
与える。The sol particles contained in the raw material precious metal sol obtained as described above are difficult to separate as they are because they are very small in particle size and do not aggregate. However, it is unstable due to its large surface energy, and when it is made into noble metal particles through subsequent heat treatment,
Condensation or surface oxidation may occur, resulting in poor quality precious metal particles.
そこで、前記のようにして得られたゾル粒子は、分離後
安定状態の保持できる粒子サイズまで貴金属ゾル粒子を
結晶成長させることが必要である。Therefore, it is necessary to crystallize the noble metal sol particles to a particle size that allows the sol particles obtained as described above to maintain a stable state after separation.
ゾル粒子の成長は、ゾルに貴金属塩と還元剤を加えるこ
とにより達成される。しかしながら、従来法の様に貴金
属塩と還元剤とを同時に加えたのでは連続的にせよ間歇
的にせよ両者の反応による新たなる核発生（微細ゾル粒
子の発生）が起るために、得られる結晶成長粒子の大き
さは不揃いなものとなり、その結果、製品の粒度分布は
ブロードなものとなる。Growth of sol particles is achieved by adding noble metal salts and reducing agents to the sol. However, if a noble metal salt and a reducing agent are added simultaneously as in the conventional method, new nucleation (generation of fine sol particles) occurs due to the reaction between the two, whether continuously or intermittently. The size of the crystal-grown particles becomes irregular, and as a result, the particle size distribution of the product becomes broad.
本発明者らは、前記ゾル粒子の結晶成長過程において、
貴金属塩の酸性水溶液及び還元剤のアルカリ性水溶液と
を用い、両者を交互に加えることにより、粒子サイズの
揃った結晶成長ゾル粒子を得ることができ、最終的に粒
度分布のシャープな貴金属粉末を製造し得ることを見出
した。The present inventors discovered that in the crystal growth process of the sol particles,
By using an acidic aqueous solution of a noble metal salt and an alkaline aqueous solution of a reducing agent, and adding the two alternately, it is possible to obtain crystal growth sol particles with uniform particle size, and finally produce a noble metal powder with a sharp particle size distribution. I found out what can be done.
即ち、本発明では、ゾル粒子の結晶成長を行うために、
貴金属を含む酸性水溶液からなるＡ液と、還元剤を含む
アルカリ性水溶液からなるＢ液とを、前記貴金属ゾル形
成工程から得られた原料ゾルに対して交互に添加するこ
とを特徴とする。このような操作においては、貴金属ゾ
ルにＡ液とＢ液を加えて生成した還元貴金属微粒子は、
原料ゾル中の貴金属ゾル粒子上に析出して貴金属ゾル粒
子を成長させるが、その還元貴金属微粒子の一部は貴金
属ゾル粒子上には析出せず、液体中に微小粒子として残
り、新たなる結晶核を発生させる。この核をそのまま残
存させて結晶成長させたゾル粒子は不揃いのものとなり
、粒度分布のブロードな製品を与えることとなる。しか
し、本発明では、Ａ液とＢ液とは交互に加えられＡ液を
加えた時には、このＡ液は酸性を示し、また微小の還元
貴金属粒子は極めて不安定であることから、Ａ液の酸と
しての作用により、その微小粒子は溶解消失する。この
ようにして、酸として作用するＡ液を加える段階におい
て、その前段のＡ液とＢ液との反応により発生した微小
核は溶解するため、微小核の結晶成長が回避され、最初
の原料ゾル形成工程で生成したゾル粒子のみが結晶成長
することになり、粒子サイズの均一化された製品を得る
ことができる。That is, in the present invention, in order to perform crystal growth of sol particles,
The method is characterized in that a solution A consisting of an acidic aqueous solution containing a noble metal and a solution B consisting of an alkaline aqueous solution containing a reducing agent are added alternately to the raw material sol obtained from the noble metal sol forming step. In such an operation, the reduced noble metal fine particles produced by adding liquid A and liquid B to the noble metal sol are
Precipitates on the noble metal sol particles in the raw material sol to grow noble metal sol particles, but some of the reduced noble metal fine particles do not precipitate on the noble metal sol particles and remain as fine particles in the liquid, forming new crystal nuclei. to occur. The sol particles that are allowed to grow as crystals while leaving this nucleus as they are become irregular, resulting in a product with a broad particle size distribution. However, in the present invention, liquids A and B are added alternately, and when liquid A is added, liquid A is acidic, and minute reduced noble metal particles are extremely unstable. By acting as an acid, the microparticles dissolve and disappear. In this way, in the step of adding liquid A, which acts as an acid, the micronuclei generated by the reaction between liquid A and liquid B in the previous step are dissolved, so crystal growth of micronuclei is avoided, and the initial raw material sol Only the sol particles generated in the formation process undergo crystal growth, and a product with uniform particle size can be obtained.
−／一
本発明においては、還元剤を含むＢ液としてはアルカリ
性を示すものを用いるが、これは、Ａ液中に含まれる酸
を中和し、ゾル粒子の結晶成長に好適なｐＨ条件を形成
させるためである。-/1 In the present invention, an alkaline solution B containing a reducing agent is used, which neutralizes the acid contained in solution A and creates pH conditions suitable for crystal growth of sol particles. This is to cause the formation.
本発明において、Ａ液として用いる貴金属塩を含む水溶
液は酸性を示すものであるが、この場合、塩化金酸の如
き酸性塩の水溶液については、必ずしも酸を加える必要
はない。しかしながら硝酸銀の如き中性塩では酸を添加
し酸性とする。また、Ａ液の酸を調節するために用いる
酸の種類は、貴金属塩の種類によって適当番こ選定する
のがよく、例えば、貴金属が銀の場合には硝酸、金及び
パラジウムの場合には王水や塩酸、白金の場合には塩酸
の使用が好ましい。本発明で用いる還元剤を含むＢ液は
アルカリ性のものであるが、この場合、そのアルカリ量
は先に加えたＡ液の酸を中和するに必要な量を含んでい
ればよい。また、Ｂ液のアルカリを調節するために用い
るアルカリの種類は、水酸化ナトリウム、水酸化カリウ
ム、水酸化カルシウム、水酸化マグネシウム等の無機塩
基や、アンモニアや有機アミン等の有機塩基等が使用可
能であるが、一般には、最終製品である貴金属粉末に他
の金属が混入することは望ましくない場合が多いことか
ら、無機塩基よりも、アンモニアや有機塩基等の非金属
性塩基の使用が有利である。またＢ液がヒドラジン等の
アルカリ性の還元剤を含む時は他のアルカリを加えなく
ても良い。In the present invention, the aqueous solution containing the noble metal salt used as liquid A is acidic, but in this case, it is not necessarily necessary to add an acid to the aqueous solution of an acidic salt such as chloroauric acid. However, in the case of a neutral salt such as silver nitrate, an acid is added to make it acidic. In addition, the type of acid used to adjust the acid in liquid A should be appropriately selected depending on the type of noble metal salt. For example, nitric acid is used when the noble metal is silver; In the case of water, hydrochloric acid, or platinum, it is preferable to use hydrochloric acid. The reducing agent-containing solution B used in the present invention is alkaline, but in this case, the amount of alkali only needs to be an amount necessary to neutralize the acid in the previously added solution A. In addition, as for the type of alkali used to adjust the alkali level of the B solution, inorganic bases such as sodium hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide, and organic bases such as ammonia and organic amines can be used. However, since it is generally undesirable for other metals to be mixed into the final precious metal powder, it is more advantageous to use nonmetallic bases such as ammonia or organic bases than inorganic bases. be. Further, when the B solution contains an alkaline reducing agent such as hydrazine, it is not necessary to add another alkali.
本発明のゾル粒子の成長工程においては、前記したよう
に、Ａ液とＢ液とを交互に添加するが、この場合、Ａ液
とＢ液の添加操作は、Ａ液とＢ液のそれぞれ１回の添加
を１回の添加操作回数として、１回でも良いが、好まし
くは複数回、通常２〜１ｏ回の添加操作を行うのが好ま
しい。また、１回の添加操作で加えるＡ液の量は、その
後に加えるＢ液との反応により析出する還元貴金属微小
粒子がなるべく結晶成長に使われ、核発生に使われない
ような量に選定することが重要である。このことは１回
当りの貴金属塩の添加量あるいはＡ液の添加量をできる
だけ少なくすることにより容易に達成し得るが、この場
合、その添加量が余りにも少なすぎるとゾル粒子の成長
速度が著しく遅くなるので、ゾル粒子の成長速度が格別
損われないように留意すべきである。一般的には、１回
のＡ液の添加量は、次のＢ液との反応により析出する還
元貴金属微粒子の直径が４０ｍμ以下、好ましくは１０
〜３０ｍμの範囲になるような量にするのがよい。この
ような貴金属微粒子は、次の回のＡ液の添加により容易
に溶解消失させることができ、かつこのような微粒子を
生成させるようなＡ液の添加量は、ゾル粒子の適度の結
晶成長を生起させる。より具体的には、原料ゾルに対す
るＡ液の１回の添加量の上限値は、ゾル中に含まれる貴
金属１００重量部に対し、ゾル中の貴金属粒子の平均粒
子をｄｍμとして下式により求められる重量部である。In the sol particle growth process of the present invention, as described above, the A liquid and the B liquid are added alternately. In this case, the addition operation of the A liquid and the B liquid is performed by The number of addition operations may be one time, but it is preferable to perform the addition operation multiple times, usually 2 to 10 times. In addition, the amount of Solution A added in one addition operation is selected so that the reduced noble metal microparticles that are precipitated by reaction with Solution B added subsequently are used for crystal growth as much as possible and are not used for nucleation. This is very important. This can be easily achieved by minimizing the amount of noble metal salt added or the amount of Solution A added per time, but in this case, if the amount added is too small, the growth rate of the sol particles will be significantly reduced. Care should be taken to ensure that the growth rate of the sol particles is not significantly impaired. Generally, the amount of addition of liquid A at one time is such that the diameter of reduced noble metal fine particles precipitated by the next reaction with liquid B is 40 mμ or less, preferably 10 mμ or less.
The amount is preferably in the range of ~30 mμ. Such noble metal fine particles can be easily dissolved and disappeared by the next addition of liquid A, and the amount of liquid A added that generates such fine particles is such that the appropriate amount of crystal growth of the sol particles can be achieved. cause to occur More specifically, the upper limit of the amount of liquid A added at one time to the raw material sol is determined by the following formula, where the average particle of noble metal particles in the sol is dmμ, with respect to 100 parts by weight of the noble metal contained in the sol. Parts by weight.
（（ｄ＋４０／ｄ）３−１） Ｘ １００また、上記式
で計算された量の添加貴金属塩が全て最初の原料ゾル中
の金属粒子の成長に使われるものと仮定すれば、Ａ液添
加操作毎に成長する粒子径Δｄを求めることができる。((d+40/d)3-1) The particle diameter Δd that grows each time can be determined.
従って、添加操作回数及びＡ液添加量を選択し、所望の
粒子径を得ることができる。また、Ａ液中の酸量は、Ａ
液添加後のゾルのｐＨが、発生核を溶解させるに十分で
あるが、結晶成長した貴金属ゾル粒子を溶解させないよ
うなｐＨ範囲になるように行う。Ａ液添加後のゾルの好
ましいｐＨ範囲は、貴金属塩の種類によって若干具なる
が、通常約ｐＨ１〜３、好ましくは約０．５〜２．０の
範囲であり、貴金属塩の種類に応じて適宜選択すればよ
い。Therefore, the desired particle size can be obtained by selecting the number of addition operations and the amount of liquid A added. In addition, the amount of acid in liquid A is
The pH of the sol after addition of the liquid is adjusted to a pH range that is sufficient to dissolve the generated nuclei, but does not dissolve the noble metal sol particles that have grown crystals. The preferred pH range of the sol after addition of Solution A varies slightly depending on the type of noble metal salt, but is usually about pH 1 to 3, preferably about 0.5 to 2.0, depending on the type of noble metal salt. You can select it as appropriate.
Ｂ液の１回の添加量は、前段に加えられたＡ液の１回の
量に含まれる貴金属塩の全てを還元するのに必要最少量
に選定する。また、このＢ液の添加は、Ｂ液添加後のゾ
ルのｐＨが貴金属微粒子が溶解しないｐＨ条件になれば
よく、一般にはｐＨ５以上になればよい。このためには
、添加するＢ液中に含まれるアルカリ量を調節したり、
Ｂ液の添加量を調節すればよい。The amount of liquid B added at one time is selected to be the minimum amount necessary to reduce all of the noble metal salts contained in the amount of liquid A added in the previous stage. Moreover, the addition of this B solution only requires that the pH of the sol after addition of the B solution be such that the noble metal fine particles do not dissolve therein, and generally the pH should be 5 or higher. For this purpose, it is necessary to adjust the amount of alkali contained in the B liquid to be added,
The amount of B liquid added may be adjusted.
本発明では、Ａ液とＢ液とを交互に加えるが、この場合
、Ａ液の添加終了後Ｂ液を添加するまでの保持時間は通
常、２分以上であればよく、好ましくは５〜２０分であ
る。又、Ｂ液の添加終了後Ａ液を添加する迄の保持時間
は還元剤の作用速度により異なるが、通常１〜２０分の
範囲にある。In the present invention, liquid A and liquid B are added alternately. In this case, the holding time from the end of addition of liquid A until the addition of liquid B is usually 2 minutes or more, preferably 5 to 20 minutes. It's a minute. Further, the holding time after the addition of the B solution until the A solution is added varies depending on the action speed of the reducing agent, but is usually in the range of 1 to 20 minutes.
前記のようにして、所望範囲の粒子サイズに結晶成長し
た貴金属粒子は、これを濾過や遠心分離等の固液分離手
段により分離し、加熱や減圧下で乾燥することにより、
目的の貴金属微粉末を得ることができる。本発明では、
一般に、平均粒度０．０５〜０．２μｍを有し、かつシ
ャープな粒度分布を有する貴金属微粉末を容易に得るこ
とができる。The noble metal particles crystal-grown to a desired particle size as described above are separated by solid-liquid separation means such as filtration or centrifugation, and dried under heating or reduced pressure.
The desired noble metal fine powder can be obtained. In the present invention,
Generally, noble metal fine powder having an average particle size of 0.05 to 0.2 μm and a sharp particle size distribution can be easily obtained.
本発明によれば、前記したように、貴金属ゾル粒子の結
晶成長過程において、ゾル粒子よりも微小な粒子は選択
的に溶解消失されることから、粒子サイズの均一化され
た結晶成長ゾル粒子を得ることができ、結果的には、粒
度分布のシャープな貴金属微粉末を得ることができる。According to the present invention, as described above, in the crystal growth process of noble metal sol particles, particles smaller than the sol particles are selectively dissolved and disappeared. As a result, noble metal fine powder with a sharp particle size distribution can be obtained.
次に本発明を実施例及び比較例によりさらに詳細に説明
する。Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.
比較例１−
ゼラチン１．５ｇ、３５ｗｔ％ホルマリン溶液７０ｇを
脱イオン水１６００ｃｃに溶解し、これを５０℃に加熱
撹拌しながら、硝酸銀１１０ｇを脱イオン水に溶解せし
めて５００ｃｃにした液を５０℃にあたためたものをゆ
っくりと添加する。得られた銀の沈殿を洗浄濾過し、１
２０℃で３０分乾燥し、試料Ｒとした。試料Ｒの比表面
積は３．６ｆｆｌ／ｇであり、平均粒子径に換算すると
１５７ｍμであった。Comparative Example 1 - 1.5 g of gelatin and 70 g of a 35 wt% formalin solution were dissolved in 1600 cc of deionized water, heated to 50°C while stirring, and a solution made by dissolving 110 g of silver nitrate in deionized water to make 500 cc was heated to 50°C. Slowly add the warmed ingredients. The obtained silver precipitate was washed and filtered, and 1
Sample R was obtained by drying at 20° C. for 30 minutes. The specific surface area of Sample R was 3.6 ffl/g, which was 157 mμ when converted to an average particle diameter.
実施例１
ゼラチン１．５ｇ、３５シｔ％ホルマリン溶液７ｇを脱
イオン水］０００ｃｃに溶解し、これを５０℃に加熱し
、撹拌しながら硝酸銀］、Ｏｇを１００ｃｃの脱イオン
水に溶解した液を加える。得られた銀のコロイド溶液を
５０℃で２０分間保持して原料ゾルとする。この原料ゾ
ルにゾル粒子として含まれる銀粒子の比表面積は８．４
ｒｒＦ／ｇであり、平均粒子径に換算すると６８ｍμで
ある。Example 1 1.5 g of gelatin and 7 g of a 35% formalin solution were dissolved in 100 cc of deionized water, heated to 50°C, and while stirring, a solution of silver nitrate and Og dissolved in 100 cc of deionized water was prepared. Add. The obtained silver colloidal solution is held at 50° C. for 20 minutes to obtain a raw material sol. The specific surface area of silver particles contained as sol particles in this raw material sol is 8.4
rrF/g, which is 68 mμ when converted to an average particle diameter.
次に硝酸銀１’ＯＯｇと６１ｗｔ％濃硝酸２５０ｇを脱
イオン水に溶解した液５００ｃｃを用意し、これをＡ液
と名づける。又、３５ｗｔ％ホルマリン溶液６３ｇを２
５νｔ％アンモニア水３４０ｇに溶かし、これを脱イオ
ン水で希釈した液５００ｃｃを用意し、これをＢ液と名
づける。Next, 500 cc of a solution was prepared by dissolving 1'OOg of silver nitrate and 250 g of 61 wt% concentrated nitric acid in deionized water, and this was named Solution A. In addition, 63 g of 35 wt% formalin solution was added to 2
500 cc of a solution was prepared by dissolving it in 340 g of 5vt% ammonia water and diluting it with deionized water, and this was named Solution B.
次に５０℃の原料ゾルを激しく撹拌しながら、これにＡ
液５０ｃｃを加えて３分間保持した。次にＢ液５０ｃＣ
を加えて５分間保持した。この操作をもう一度繰り返し
た後、Ａ液の添加量を１００ｃｃ、保持時間を５分、Ｂ
液の添加量を１００ｃｃ、保持時間を５分にして、添加
操作を行なった。得られたゾルの内２００ｃｃを表面積
測定用試料Ｓ−１とした。次に残りのゾルにＡ液１００
ｃｃ、保持時間を５分、Ｂ液１００ｃｃ、保持時間を５
分により交互添加を３回繰り返し添加操作を終了した。Next, while stirring the raw material sol at 50°C, add A to it.
50 cc of liquid was added and held for 3 minutes. Next, 50 cC of B liquid
was added and held for 5 minutes. After repeating this operation once more, add 100 cc of liquid A, hold for 5 minutes, and
The addition operation was performed with the amount of liquid added being 100 cc and the holding time being 5 minutes. 200 cc of the obtained sol was used as sample S-1 for surface area measurement. Next, add 100 parts of liquid A to the remaining sol.
cc, holding time 5 minutes, B liquid 100cc, holding time 5
The addition operation was completed by repeating the alternating addition three times.
得られた液中の銀は凝集沈殿状態にあった。The silver in the obtained liquid was in a coagulated and precipitated state.
この試料をＳ−２とした。Ｓ−１、Ｓ−２とも洗滌濾過
後、１２０℃で３０分間乾燥後表面積を測定したところ
、Ｓ−１は５．３ｒｒ？／ｇ、 ｓ−ｚは３ 、 Ｏｒ
ｒｒ ／ ｇを示した。これは平均粒子径に換算すると
、１０８ｍμ、１９２ｍμに相当する。又、走査電子顕
微鏡で、試料Ｒと試料Ｓ−２を比較すると、試料Ｓ−２
は試料Ｒに比較して５０ｍμ以下及び１０００ｍμ以上
の粒子が明らかに少なく、粒子径の揃っていることが確
認された。This sample was named S-2. After washing and filtering both S-1 and S-2, the surface area was measured after drying at 120°C for 30 minutes, and the surface area of S-1 was 5.3rr? /g, s-z is 3, Or
showed rr/g. This corresponds to 108 mμ and 192 mμ when converted to average particle diameter. Also, when comparing sample R and sample S-2 with a scanning electron microscope, sample S-2
Compared to Sample R, there were clearly fewer particles of 50 mμ or less and 1000 mμ or more, and it was confirmed that the particle sizes were uniform.
−１５＝−15=
Claims (1)
あたり、 （ｉ）該貴金属塩水溶液を還元して原料貴金属ゾルを形
成する工程、 （ｉｉ）該原料貴金属ゾルに、貴金属塩を含む酸性水溶
液と、還元剤を含むアルカリ性水溶液とを少なくとも１
回交互に添加して、該貴金属ゾル粒子を成長させる工程
、 からなることを特徴とする粒度分布の均一化された貴金
属微粉末の製造方法。(1) In reducing the noble metal salt aqueous solution to obtain the noble metal fine powder, (i) reducing the noble metal salt aqueous solution to form a raw material noble metal sol; (ii) acidifying the raw material noble metal sol containing the noble metal salt; at least one aqueous solution and an alkaline aqueous solution containing a reducing agent.
1. A method for producing noble metal fine powder with a uniform particle size distribution, comprising the step of growing the noble metal sol particles by adding the noble metal sol particles alternately.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14297887A JPS63307208A (en) | 1987-06-08 | 1987-06-08 | Production of fine noble metal powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14297887A JPS63307208A (en) | 1987-06-08 | 1987-06-08 | Production of fine noble metal powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63307208A true JPS63307208A (en) | 1988-12-14 |
Family
ID=15328081
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14297887A Pending JPS63307208A (en) | 1987-06-08 | 1987-06-08 | Production of fine noble metal powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63307208A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GR900100722A (en) * | 1989-09-29 | 1992-01-20 | Ortho Diagnostic Systems Inc | Method of producing a reagent containing a narrow distribution of colloidal particles of a selected size and the use thereof |
| JP2002239372A (en) * | 2001-02-20 | 2002-08-27 | Bando Chem Ind Ltd | Colloidal metal solution |
| JP2004075703A (en) * | 2002-08-09 | 2004-03-11 | Nippon Paint Co Ltd | Method of preparing metal colloidal solution and metal colloidal solution |
| JP2007314869A (en) * | 2006-05-25 | 2007-12-06 | Samsung Electro-Mechanics Co Ltd | Method of producing metal nanoparticle and metal nanoparticle produced thereby |
| JP2007321232A (en) * | 2006-06-05 | 2007-12-13 | Tanaka Kikinzoku Kogyo Kk | Method for producing gold colloid, and gold colloid |
| JP2009515693A (en) * | 2005-11-14 | 2009-04-16 | アンスティテュ フランセ デュ ペトロール | Process for producing a catalyst based on anisotropic metal nanoparticles in the presence of a reducing agent |
| JP4526200B2 (en) * | 2001-02-20 | 2010-08-18 | バンドー化学株式会社 | Method for producing metal colloid liquid |
| JP2013036116A (en) * | 2011-08-05 | 2013-02-21 | China Steel Corp | Flaky silver particle of microscale and method for producing the same |
| JP2017057480A (en) * | 2015-09-18 | 2017-03-23 | 田中貴金属工業株式会社 | Manufacturing method of noble metal powder |
-
1987
- 1987-06-08 JP JP14297887A patent/JPS63307208A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GR900100722A (en) * | 1989-09-29 | 1992-01-20 | Ortho Diagnostic Systems Inc | Method of producing a reagent containing a narrow distribution of colloidal particles of a selected size and the use thereof |
| JP2002239372A (en) * | 2001-02-20 | 2002-08-27 | Bando Chem Ind Ltd | Colloidal metal solution |
| JP4526200B2 (en) * | 2001-02-20 | 2010-08-18 | バンドー化学株式会社 | Method for producing metal colloid liquid |
| JP4683399B2 (en) * | 2001-02-20 | 2011-05-18 | バンドー化学株式会社 | Metal colloid liquid |
| JP2004075703A (en) * | 2002-08-09 | 2004-03-11 | Nippon Paint Co Ltd | Method of preparing metal colloidal solution and metal colloidal solution |
| JP2009515693A (en) * | 2005-11-14 | 2009-04-16 | アンスティテュ フランセ デュ ペトロール | Process for producing a catalyst based on anisotropic metal nanoparticles in the presence of a reducing agent |
| JP2007314869A (en) * | 2006-05-25 | 2007-12-06 | Samsung Electro-Mechanics Co Ltd | Method of producing metal nanoparticle and metal nanoparticle produced thereby |
| JP2007321232A (en) * | 2006-06-05 | 2007-12-13 | Tanaka Kikinzoku Kogyo Kk | Method for producing gold colloid, and gold colloid |
| WO2007142082A1 (en) * | 2006-06-05 | 2007-12-13 | Tanaka Kikinzoku Kogyo K.K. | Process for production of colloidal gold and colloidal gold |
| US8048193B2 (en) | 2006-06-05 | 2011-11-01 | Tanaka Kikinzoku Kogyo K.K. | Method for producing gold colloid and gold colloid |
| JP2013036116A (en) * | 2011-08-05 | 2013-02-21 | China Steel Corp | Flaky silver particle of microscale and method for producing the same |
| JP2017057480A (en) * | 2015-09-18 | 2017-03-23 | 田中貴金属工業株式会社 | Manufacturing method of noble metal powder |
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