JP2007138249A - Method for producing silver grain, silver grain-containing composition containing the obtained silver grain and its use - Google Patents
Method for producing silver grain, silver grain-containing composition containing the obtained silver grain and its use Download PDFInfo
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本発明は、可視光や近赤外光の特定波長に対する選択的吸収機能を有する粒子径がナノオーダのプレート状銀粒子を簡易的に製造する方法及び得られた該銀粒子を含有する銀粒子含有組成物並びにその用途に関する。 The present invention is a method for easily producing plate-like silver particles having a nano-order particle size having a selective absorption function for a specific wavelength of visible light or near-infrared light, and silver particles containing the obtained silver particles The present invention relates to a composition and its use.
貴金属のコロイドは化学的に変化し難く、粒径が数ｎｍ〜数十ｎｍ程度の、いわゆるナノ粒子を構成する。また各コロイド特有の色を発色し、塗料や樹脂組成物の着色剤への用途を含む各種用途への適用が期待されている。
このような発色金属粒子の製造方法として、例えば、非結晶銀粒子の懸濁液に７００ｎｍ未満の波長を有する光源を晒すことで銀結晶を形成するナノプリズムの形成方法が開示されている（例えば、特許文献１参照。）。この方法によりプレート状の銀の単結晶が形成される。また、クエン酸三ナトリウムと硝酸銀が溶解している水溶液中で、水素化ホウ素ナトリウムにより銀イオンを還元して合成した球状銀コロイド中にＢＳＰＰ（Bis(p-sulfonatophenyl) phenylphosphine dehydrate dipotassium salt）を滴下した水溶液に、蛍光灯を照射することで銀ナノプリズムを合成する方法が開示されている（例えば、非特許文献１参照。）。また、クエン酸三ナトリウムとＢＳＰＰが溶解している水溶液中で、水素化ホウ素ナトリウムにより銀イオンを還元して合成した銀コロイドに、フィルターで選択した２種類の波長の可視光線を照射することで、銀ナノプリズムの吸収波長を制御する方法がある。また、銀ナノプリズムの辺の長さが長くなるにつれ、プラズモン吸収が長波長側にシフトすることが知られている（例えば、非特許文献２参照。）。また、クエン酸三ナトリウムとＢＳＰＰあるいはＰＶＰが溶解している水溶液中で、水素化ホウ素ナトリウムにより銀イオンを還元して合成した銀コロイドに、蛍光灯→フィルターで選択した１種類の波長の可視光線を照射することで、銀ナノプレートの吸収波長を制御する方法がある（例えば、非特許文献３参照。）。
Noble metal colloids hardly change chemically and constitute so-called nanoparticles having a particle size of about several nanometers to several tens of nanometers. In addition, it is expected to be applied to various uses, including the use as a colorant for paints and resin compositions, by developing colors specific to each colloid.
As a method for producing such colored metal particles, for example, a nanoprism forming method is disclosed in which a silver crystal is formed by exposing a suspension of amorphous silver particles to a light source having a wavelength of less than 700 nm (for example, , See Patent Document 1). By this method, a plate-like silver single crystal is formed. Also, BSPP (Bis (p-sulfonatophenyl) phenylphosphine dehydrate dipotassium salt) is dropped into a spherical silver colloid synthesized by reducing silver ions with sodium borohydride in an aqueous solution in which trisodium citrate and silver nitrate are dissolved. A method of synthesizing silver nanoprisms by irradiating the aqueous solution with a fluorescent lamp is disclosed (for example, see Non-Patent Document 1). In addition, silver colloid synthesized by reducing silver ions with sodium borohydride in an aqueous solution in which trisodium citrate and BSPP are dissolved is irradiated with visible light with two wavelengths selected by a filter. There is a method for controlling the absorption wavelength of the silver nanoprism. Further, it is known that plasmon absorption shifts to the longer wavelength side as the length of the side of the silver nanoprism becomes longer (for example, see Non-Patent Document 2). In addition, a silver colloid synthesized by reducing silver ions with sodium borohydride in an aqueous solution in which trisodium citrate and BSPP or PVP are dissolved is combined with visible light of one wavelength selected by fluorescent lamp → filter. There is a method of controlling the absorption wavelength of the silver nanoplate by irradiating (see Non-Patent Document 3, for example).
また、金属微粒子に光を照射したときに生じるプラズモン吸収と呼ばれる共鳴吸収現象を利用して塗料としての着色性や溶液の安定性を高めた塗料が開発されている（例えば、特許文献２及び３参照。）。特許文献２では、貴金属又は銅の化合物を、溶媒に溶解し、高分子量顔料分散剤を加えた後、貴金属又は銅に還元することで彩度が高く、十分な着色性を有し、塗料や樹脂に添加しても凝集しない貴金属又は銅のコロイド溶液の製造方法が開示されている。この特許文献２によると、貴金属コロイドによる発色は、電子のプラズマ振動に起因し、プラズモン吸収と呼ばれる発色機構によるものであり、プラズモン吸収による発色は、金属中の自由電子が光電場により揺さぶられ、粒子表面に電荷が現れ、非線形分極が生じるためとある。特許文献３では、水相の貴金属又は銅のイオンを還元することにより、貴金属又は銅の生成と、水相から、水と非混和性の有機溶媒相への貴金属又は銅の相間移動とを生ぜしめ、有機溶媒相内に安定な貴金属又は銅のコロイド粒子を得る製造方法が開示されている。特許文献３に示される方法により得られた貴金属又は銅のコロイドは安定でかつ高濃度で存在するようになり、濃色で彩度が高く、着色剤として好適であると記載されている。 In addition, paints have been developed that improve the colorability of the paint and the stability of the solution by utilizing a resonance absorption phenomenon called plasmon absorption that occurs when the metal fine particles are irradiated with light (for example, Patent Documents 2 and 3). reference.). In Patent Document 2, a noble metal or copper compound is dissolved in a solvent, and after adding a high molecular weight pigment dispersant, it is reduced to the noble metal or copper so that it has high chroma and has sufficient coloration properties. A method for producing a colloidal solution of noble metal or copper that does not aggregate when added to a resin is disclosed. According to this Patent Document 2, the color development due to the noble metal colloid is caused by the plasma vibration of electrons and is due to a color development mechanism called plasmon absorption. The color development due to plasmon absorption is caused by free electrons in the metal being shaken by the photoelectric field, This is because charges appear on the particle surface and nonlinear polarization occurs. In Patent Document 3, by reducing the noble metal or copper ions in the aqueous phase, generation of the noble metal or copper and interphase transfer of the noble metal or copper from the aqueous phase to the organic solvent phase immiscible with water are produced. In other words, a production method for obtaining colloidal particles of stable noble metal or copper in an organic solvent phase is disclosed. The noble metal or copper colloid obtained by the method disclosed in Patent Document 3 is stable and exists in a high concentration, and is described as being dark and highly saturated, and suitable as a colorant.
また、銀塩のアンミン錯体及び還元反応の際に媒晶剤として機能する重金属塩のアンミン錯体を含むスラリーと、還元剤である亜硫酸カリ及び保護コロイドとしてのゼラチンを含有する溶液とを一時に混合して該銀塩のアンミン錯体を還元し、生成した銀粒子を回収することで１次粒子の粒径が５〜１０μｍの六角板状結晶銀微粒子を製造する方法が知られている（例えば、特許文献４参照。）。また、２つの主面を有する略板状の粒子であり、該粒子の厚さが５０ｎｍ以下、長径が５０００ｎｍ以下であることを特徴とする銀微粒子が知られている（例えば、特許文献５参照。）。この特許文献５に示される方法では少なくとも高分子化合物、還元剤、及び銀塩を溶解してなる溶液を、２５℃以上、６０℃以下の温度にて攪拌することで銀微粒子を製造している。更に、厚みが５０ｎｍ以下かつ長径が５０００ｎｍ以下の板状金属微粒子を含有してなることを特徴とする金属薄膜形成用塗料が知られている（例えば、特許文献６参照。）。この特許文献６によると、この板状金属微粒子は例えば、硝酸銀や塩化白金酸を含む水溶液にクエン酸を加え、この水溶液中の金属イオンとクエン酸との比或いは金属イオン濃度等を調整することにより、金属微粒子の厚み及び長径を制御し、その後、加熱還元することにより製造することができるとある。
上記特許文献１や非特許文献１〜３に記載されている銀プリズムや銀プレートの製造においては、銀イオンを球状銀コロイドに還元する第一工程と、第一工程で還元した銀コロイドに光照射して銀プリズムや銀プレートへと形状変化させる第二工程といった、多段階の製造工程が必要とされていた。また形状変化させる際に特定波長光を長時間照射することから、大量生産には不向きであった。更に、得られる銀微粒子表面には高分子量の分散剤が吸着しており、別な化学物質を銀表面に修飾しにくいという問題もあった。 In the production of the silver prism and silver plate described in Patent Document 1 and Non-Patent Documents 1 to 3, the first step of reducing silver ions to a spherical silver colloid and the silver colloid reduced in the first step with light. A multi-step manufacturing process was required, such as a second step of irradiation to change the shape into a silver prism or silver plate. Moreover, since the specific wavelength light is irradiated for a long time when the shape is changed, it is not suitable for mass production. Furthermore, there is a problem that a high molecular weight dispersant is adsorbed on the surface of the obtained silver fine particles, and it is difficult to modify another chemical substance on the silver surface.
また、特許文献２や特許文献３に示される方法では、球状の貴金属コロイドを着色剤として使用しており、プレート状の微粒子を着色剤として用いたものではないため、着色のバリエーションが得られない。また、特許文献２に示される貴金属又は銅のコロイドは、高分子量顔料分散剤が保護コロイドとして機能するため、別の化学物質を銀表面に修飾しにくいという問題があった。特許文献４及び特許文献５に示される銀微粒子の製造方法では、分散剤として高分子化合物を使用しているため、得られる銀微粒子には高分子化合物が吸着しており、別の化学物質を銀表面に修飾し難いという問題があった。また、特許文献６に示される板状金属微粒子の製造方法では、金属微粒子の厚み及び長径を制御した後に加熱還元を行う必要があり、製造工程が煩雑となっていた。 Further, in the methods shown in Patent Document 2 and Patent Document 3, since a spherical noble metal colloid is used as a colorant and plate-shaped fine particles are not used as a colorant, variations in coloring cannot be obtained. . Further, the noble metal or copper colloid disclosed in Patent Document 2 has a problem that it is difficult to modify another chemical substance on the silver surface because the high molecular weight pigment dispersant functions as a protective colloid. In the method for producing silver fine particles shown in Patent Document 4 and Patent Document 5, since a polymer compound is used as a dispersant, the polymer compound is adsorbed on the obtained silver fine particles, and another chemical substance is used. There was a problem that it was difficult to modify the silver surface. Further, in the method for producing plate-like metal fine particles disclosed in Patent Document 6, it is necessary to carry out heat reduction after controlling the thickness and the major axis of the metal fine particles, which makes the production process complicated.
本発明の目的は、銀イオン、低分子系分散剤及び還元剤を用いてプレート状銀粒子を簡便に製造する方法及び得られた該銀粒子を含有する銀粒子含有組成物並びにその用途を提供することにある。 An object of the present invention is to provide a method for easily producing plate-like silver particles using silver ions, a low molecular weight dispersant, and a reducing agent, a silver particle-containing composition containing the obtained silver particles, and use thereof. There is to do.
請求項１に係る発明は、水に銀塩及び低分子系分散剤を加えて銀塩及び低分子系分散剤の水溶液を調製し、水溶液に所定の割合で還元剤を添加して混合液を調製し、混合液を２０〜４０℃で静置して混合液中の銀イオンを還元反応させることにより、主として形状がプレート状の銀粒子を製造する方法であって、銀塩と低分子系分散剤と還元剤の添加割合がモル比率で銀塩：低分子系分散剤：還元剤＝１：（０．１〜１００）：（０．００１〜１００）であることを特徴とする銀粒子の製造方法である。
請求項２に係る発明は、請求項１に係る発明であって、低分子系分散剤がクエン酸、リンゴ酸、酒石酸及びコハク酸からなる群より選ばれた１種又は２種以上の有機酸又はその塩である製造方法である。
請求項３に係る発明は、請求項１に係る発明であって、還元剤がジメチルアミンボラン又はヒドラジンのいずれか一方又はその双方の化合物である製造方法である。
請求項４に係る発明は、請求項１に係る発明であって、得られるプレート状銀粒子の粒子径が１０〜１０００ｎｍである製造方法である。
The invention according to claim 1 prepares an aqueous solution of a silver salt and a low molecular weight dispersant by adding a silver salt and a low molecular weight dispersant to water, and adds a reducing agent to the aqueous solution at a predetermined ratio to prepare a mixed solution. A method of producing silver particles mainly having a plate shape by preparing and allowing the mixed solution to stand at 20 to 40 ° C. to cause reduction reaction of silver ions in the mixed solution. Silver particles characterized in that the addition ratio of the dispersing agent and the reducing agent is a molar ratio of silver salt: low molecular weight dispersant: reducing agent = 1: (0.1-100) :( 0.001-100) It is a manufacturing method.
The invention according to claim 2 is the invention according to claim 1, wherein the low molecular dispersant is one or more organic acids selected from the group consisting of citric acid, malic acid, tartaric acid and succinic acid. Or the manufacturing method which is its salt.
The invention according to claim 3 is the method according to claim 1, wherein the reducing agent is a compound of either one or both of dimethylamine borane and hydrazine.
The invention according to claim 4 is the manufacturing method according to claim 1, wherein the obtained plate-like silver particles have a particle diameter of 10 to 1000 nm.
請求項５に係る発明は、請求項１ないし４いずれか１項に記載の製造方法により得られた銀粒子を含有することを特徴とする銀粒子含有組成物である。
請求項６に係る発明は、請求項５記載の銀粒子含有組成物を用いて形成されたコーティング組成物、塗膜又はフィルムである。
請求項７に係る発明は、請求項１ないし４いずれか１項に記載の製造方法により得られた銀粒子を含有する光学フィルタ、配線材料、電極材料、触媒、着色剤、化粧品、近赤外線吸収剤、偽造防止インク、電磁波シールド材、表面増強蛍光センサ、生体マーカ、記録素子、薬物送達システム（Drug Delivery System；以下ＤＤＳという。）用薬物保持体、バイオセンサ、ＤＮＡチップ、検査薬又はラマン増強用試薬である。
The invention according to claim 5 is a silver particle-containing composition comprising silver particles obtained by the production method according to any one of claims 1 to 4.
The invention which concerns on Claim 6 is a coating composition, a coating film, or a film formed using the silver particle containing composition of Claim 5.
The invention according to claim 7 is an optical filter, a wiring material, an electrode material, a catalyst, a colorant, a cosmetic, a near-infrared absorption containing silver particles obtained by the production method according to any one of claims 1 to 4. Agent, anti-counterfeiting ink, electromagnetic shielding material, surface-enhanced fluorescent sensor, biomarker, recording element, drug carrier for drug delivery system (DDS), biosensor, DNA chip, test drug or Raman enhancement Reagent.
本発明の銀粒子の製造方法は、水に銀塩及び低分子系分散剤を加えて銀塩及び低分子系分散剤の水溶液を調製し、この水溶液に所定の割合で還元剤を添加して混合液を調製し、混合液を２０〜４０℃で静置して混合液中の銀イオンを還元反応させることにより、主として形状がプレート状の銀粒子を製造する方法であり、銀塩と低分子系分散剤と還元剤の添加割合がモル比率で銀塩：低分子系分散剤：還元剤＝１：（０．１〜１００）：（０．００１〜１００）であることを特徴とする。モル比率が上記範囲内となるように銀塩、低分子系分散剤及び還元剤を添加して混合液を調製し、この混合液を２０〜４０℃で静置して混合液中の銀イオンを還元反応させることにより、所定の粒子径を有するプレート状銀粒子を簡便に製造することができる。また低分子系分散剤としてクエン酸、リンゴ酸、酒石酸及びコハク酸からなる群より選ばれた１種又は２種以上の有機酸又はその塩を用いることで、プレート状銀粒子が安定に分散した水溶液を得ることができ、プレート状銀粒子を効率よく製造することができる。還元剤としてジメチルアミンボラン又はヒドラジンのいずれか一方又はその双方の化合物を用いることで、プレート状銀粒子を再現良く得ることができる。 In the method for producing silver particles of the present invention, a silver salt and a low molecular weight dispersant are added to water to prepare an aqueous solution of a silver salt and a low molecular weight dispersant, and a reducing agent is added to the aqueous solution at a predetermined ratio. This is a method for producing silver particles mainly having a plate shape by preparing a mixed solution and allowing the mixed solution to stand at 20 to 40 ° C. to cause silver ions in the mixed solution to undergo a reduction reaction. The addition ratio of the molecular dispersant and the reducing agent is silver salt: low molecular dispersant: reducing agent = 1: (0.1-100) :( 0.001-100) in a molar ratio. . A silver salt, a low molecular weight dispersant and a reducing agent are added so that the molar ratio is within the above range to prepare a mixed solution, and this mixed solution is allowed to stand at 20 to 40 ° C. to obtain silver ions in the mixed solution. By carrying out the reduction reaction, plate-like silver particles having a predetermined particle diameter can be easily produced. In addition, by using one or more organic acids selected from the group consisting of citric acid, malic acid, tartaric acid and succinic acid or salts thereof as the low molecular weight dispersant, the plate-like silver particles are stably dispersed. An aqueous solution can be obtained and plate-like silver particles can be produced efficiently. By using one or both of dimethylamine borane and hydrazine as the reducing agent, plate-like silver particles can be obtained with good reproducibility.
また、本発明の製造方法により得られた銀粒子は、銀粒子含有組成物として利用することができる。また、銀粒子とともに染料、顔料、蛍光体、金属酸化物、球状金属粒子及びロッド状金属粒子（金属ナノロッド）からなる群より選ばれた１種又は２種以上を含有することで銀粒子含有組成物として利用することができる。この銀粒子含有組成物は、コーティング組成物、塗膜又はフィルムなどの各種形態で利用することができる。
更に、本発明の製造方法により得られた銀粒子は光学フィルタ、配線材料、電極材料、触媒、着色剤、化粧品、近赤外線吸収剤、偽造防止インク、電磁波シールド材、表面増強蛍光センサ、生体マーカ、記録素子、薬物送達システム用薬物保持体、バイオセンサ、ＤＮＡチップ、検査薬又はラマン増強用試薬などに広く利用することができる。
Moreover, the silver particle obtained by the manufacturing method of this invention can be utilized as a silver particle containing composition. Moreover, silver particle containing composition by containing 1 type, or 2 or more types chosen from the group which consists of dye, a pigment, fluorescent substance, a metal oxide, a spherical metal particle, and a rod-shaped metal particle (metal nanorod) with silver particle It can be used as a thing. This silver particle containing composition can be utilized with various forms, such as a coating composition, a coating film, or a film.
Furthermore, the silver particles obtained by the production method of the present invention are optical filters, wiring materials, electrode materials, catalysts, colorants, cosmetics, near infrared absorbers, anti-counterfeiting inks, electromagnetic wave shielding materials, surface-enhanced fluorescent sensors, biomarkers. It can be widely used for a recording element, a drug holder for a drug delivery system, a biosensor, a DNA chip, a test agent, a Raman enhancement reagent, and the like.
次に本発明を実施するための最良の形態を説明する。
本発明で「プレート状銀粒子」とは、２つの主面を有する略板状の銀粒子である。略板状の銀粒子の主面は、略三角形状、略五角形状、略六角形状等の形状が選択される。この粒子形状において、角や辺が一部欠けた不定形状の粒子を一部含有していても構わない。銀粒子の２つの主面の幅は４０ｎｍ以下であり、粒子の主面の最大長さとなる粒子径は１０〜１０００ｎｍである。プレート状銀粒子のアスペクト比（プレート状銀粒子の主面の最大長さ／主面の幅）は３以上である。
Next, the best mode for carrying out the present invention will be described.
In the present invention, “plate-like silver particles” are substantially plate-like silver particles having two main surfaces. The main surface of the substantially plate-like silver particles is selected from shapes such as a substantially triangular shape, a substantially pentagonal shape, and a substantially hexagonal shape. This particle shape may contain a part of irregularly shaped particles with some missing corners and sides. The width of the two main surfaces of the silver particles is 40 nm or less, and the particle diameter that is the maximum length of the main surfaces of the particles is 10 to 1000 nm. The aspect ratio of the plate-like silver particles (the maximum length of the main surface of the plate-like silver particles / the width of the main surface) is 3 or more.
本発明の銀粒子の製造方法は、水に銀塩及び低分子系分散剤を加えて銀塩及び低分子系分散剤の水溶液を調製し、この水溶液に所定の割合で還元剤を添加して混合液を調製し、混合液を２０〜４０℃で静置して混合液中の銀イオンを還元反応させることにより、主として形状がプレート状の銀粒子を製造する方法である。その特徴ある構成は、銀塩と低分子系分散剤と還元剤の添加割合がモル比率で銀塩：低分子系分散剤：還元剤＝１：（０．１〜１００）：（０．００１〜１００）であるところにある。モル比率が上記範囲内となるように銀塩、低分子系分散剤及び還元剤を添加して混合液を調製し、この混合液を２０〜４０℃で静置して混合液中の銀イオンを還元反応させることにより、所定の粒子径を有するプレート状銀粒子を簡便に製造することができる。 In the method for producing silver particles of the present invention, a silver salt and a low molecular weight dispersant are added to water to prepare an aqueous solution of a silver salt and a low molecular weight dispersant, and a reducing agent is added to the aqueous solution at a predetermined ratio. This is a method for producing mainly silver particles having a plate shape by preparing a mixed solution and allowing the mixed solution to stand at 20 to 40 ° C. to cause a reduction reaction of silver ions in the mixed solution. The characteristic structure is that silver salt, low molecular weight dispersant and reducing agent are added in a molar ratio of silver salt: low molecular weight dispersant: reducing agent = 1: (0.1-100) :( 0.001 ~ 100). A silver salt, a low molecular weight dispersant and a reducing agent are added so that the molar ratio is within the above range to prepare a mixed solution, and this mixed solution is allowed to stand at 20 to 40 ° C. to obtain silver ions in the mixed solution. By carrying out the reduction reaction, plate-like silver particles having a predetermined particle diameter can be easily produced.
使用する銀塩としては、硝酸銀、硫酸銀、酢酸銀、ハロゲン化銀等が挙げられる。このうち、硝酸銀が水への溶解性が高いため特に好適である。混合液を調製する際には、銀塩は水に溶解して水溶液として添加混合することが好適である。銀塩は水溶液中で銀イオン及び陰イオンとして存在する。製造する際の銀濃度は１０〜１０００００μｍｏｌ／Ｌの範囲が適当であり、１００〜１００００μｍｏｌ／Ｌの濃度範囲が特に好ましい。銀濃度が下限値未満ではプレート状銀粒子の製造効率が低下してしまい、上限値を越えると銀粒子の均一な成長が妨げられ、プレート状銀粒子の形状再現性が低下する。 Examples of the silver salt used include silver nitrate, silver sulfate, silver acetate and silver halide. Of these, silver nitrate is particularly preferred because of its high solubility in water. When preparing the mixed solution, the silver salt is preferably dissolved in water and added and mixed as an aqueous solution. Silver salts exist as silver ions and anions in aqueous solutions. The silver concentration in the production is suitably in the range of 10 to 100,000 μmol / L, particularly preferably in the range of 100 to 10,000 μmol / L. If the silver concentration is less than the lower limit, the production efficiency of the plate-like silver particles decreases, and if it exceeds the upper limit, uniform growth of the silver particles is hindered, and the shape reproducibility of the plate-like silver particles decreases.
使用する低分子系分散剤としては、クエン酸、リンゴ酸、酒石酸及びコハク酸からなる群より選ばれた１種又は２種以上の有機酸又はその塩が挙げられる。上記種類の低分子系分散剤を用いることによって、凝集することなく銀粒子が安定に分散した水溶液を得ることができ、効率よく銀粒子を製造することができる。低分子系分散剤は水に混合して低分子系分散剤を溶解した水溶液とした後に、この低分子系分散剤を溶解した水溶液と銀塩を溶解した水溶液とを混合して銀塩及び低分子系分散剤の水溶液を調製するのが好ましい。低分子系分散剤は、銀塩とのモル比率が銀塩：低分子系分散剤＝１：（０．１〜１００）の範囲内となるように添加する。例えば、銀１μｍｏｌに対して０．１〜１００μｍｏｌのモル割合となるように添加する。製造する際の低分子系分散剤の濃度は１〜１０００００００μｍｏｌ／Ｌの範囲が適当であり、１０〜１００００００μｍｏｌ／Ｌの濃度範囲がより好ましい。低分子系分散剤の濃度が下限値未満では、銀イオンの還元反応が急激に進行してしまうためプレート状銀粒子が製造し難くなるだけでなく、銀粒子の分散安定性が悪くなって凝集し易くなる。低分子系分散剤の濃度が上限値を越えると、球状銀粒子の生成割合が増加し、プレート状銀粒子の生成量が減少する。そのためプレート状銀粒子を製造するコストが上昇してしまう不具合を生じる。 Examples of the low molecular weight dispersant used include one or more organic acids selected from the group consisting of citric acid, malic acid, tartaric acid, and succinic acid, or salts thereof. By using the above kind of low molecular weight dispersant, an aqueous solution in which silver particles are stably dispersed without aggregation can be obtained, and silver particles can be produced efficiently. The low molecular weight dispersant is mixed with water to make an aqueous solution in which the low molecular weight dispersant is dissolved, and then the aqueous solution in which the low molecular weight dispersant is dissolved and the aqueous solution in which the silver salt is dissolved are mixed to form a silver salt and a low molecular weight dispersant. It is preferable to prepare an aqueous solution of a molecular dispersant. The low molecular weight dispersant is added so that the molar ratio with the silver salt falls within the range of silver salt: low molecular weight dispersant = 1: (0.1 to 100). For example, it adds so that it may become a molar ratio of 0.1-100 micromol with respect to 1 micromol of silver. The concentration of the low molecular weight dispersant during production is suitably in the range of 1 to 10000000 μmol / L, more preferably in the range of 10 to 1000000 μmol / L. If the concentration of the low molecular weight dispersant is less than the lower limit, the reduction reaction of silver ions proceeds rapidly, so that not only plate-like silver particles are difficult to produce, but also the dispersion stability of the silver particles deteriorates and agglomerates. It becomes easy to do. When the concentration of the low molecular weight dispersant exceeds the upper limit, the production rate of spherical silver particles increases and the production amount of plate-like silver particles decreases. Therefore, the malfunction which raises the cost which manufactures plate-like silver particle arises.
使用する還元剤としては、ジメチルアミンボラン又はヒドラジンのいずれか一方又はその双方の化合物が挙げられる。還元剤を添加する際には、局所的に還元剤の濃度が偏らないよう、調製した銀塩及び低分子系分散剤の水溶液を攪拌しながら還元剤を添加することが好ましい。還元剤は、銀塩とのモル比率が銀塩：還元剤＝１：（０．００１〜１００）の範囲内となるように添加する。還元剤は使用する種類によって、以下のような適切な割合で添加することが好ましい。 As a reducing agent to be used, either one or both of dimethylamine borane and hydrazine may be mentioned. When adding the reducing agent, it is preferable to add the reducing agent while stirring the aqueous solution of the prepared silver salt and low molecular weight dispersant so that the concentration of the reducing agent is not locally biased. The reducing agent is added so that the molar ratio with the silver salt falls within the range of silver salt: reducing agent = 1: (0.001 to 100). The reducing agent is preferably added at an appropriate ratio as follows depending on the type used.
ジメチルアミンボランは水に混合して任意の濃度の水溶液とした後に、このジメチルアミンボランを溶解した水溶液と銀塩及び低分子系分散剤の水溶液とを混合して混合液を調製する。還元剤にジメチルアミンボランを使用した場合の添加量は、モル比で銀塩：還元剤＝１：（０．１〜１００）が好ましい。銀塩に対する還元剤の添加量が上記割合よりも少ないと、混合液中の銀イオンの還元反応が不十分となり、プレート状銀粒子の収率が悪くなる。また、還元剤の添加量が上記割合よりも多いと、還元反応が急激に進行してしまい、球状銀粒子が多く発生し、プレート状銀粒子の生成量が少なくなる。
ヒドラジンは原液若しくは水に混合して任意の濃度の水溶液とした後に、ヒドラジン原液若しくはヒドラジンを溶解した水溶液と銀塩及び低分子系分散剤の水溶液とを混合して混合液を調製する。還元剤にヒドラジンを使用した場合の添加量は、モル比で銀塩：ヒドラジン＝１：（０．１〜１０）が好ましい。銀塩に対するヒドラジンの添加量が上記割合よりも少ないと、混合液中の銀イオンの還元が不十分となり、プレート状銀粒子の収率が悪くなる。また、ヒドラジンの添加量が上記割合よりも多いと、還元反応が急激に進行してしまい、球状銀粒子が多く発生し、プレート状銀粒子の生成量が少なくなる。
Dimethylamine borane is mixed with water to obtain an aqueous solution having an arbitrary concentration, and then an aqueous solution in which dimethylamine borane is dissolved is mixed with an aqueous solution of a silver salt and a low molecular weight dispersant to prepare a mixed solution. The addition amount when dimethylamine borane is used as the reducing agent is preferably silver salt: reducing agent = 1: (0.1 to 100) in molar ratio. When the addition amount of the reducing agent with respect to the silver salt is less than the above ratio, the reduction reaction of silver ions in the mixed solution becomes insufficient, and the yield of the plate-like silver particles is deteriorated. Moreover, when there are more addition amounts of a reducing agent than the said ratio, a reductive reaction will advance rapidly, many spherical silver particles will generate | occur | produce, and the production amount of plate-like silver particles will decrease.
Hydrazine is mixed with an undiluted solution or water to obtain an aqueous solution having an arbitrary concentration, and then a mixed solution is prepared by mixing an aqueous solution of hydrazine undiluted solution or hydrazine with an aqueous solution of a silver salt and a low molecular weight dispersant. The addition amount when hydrazine is used as the reducing agent is preferably silver salt: hydrazine = 1: (0.1 to 10) in molar ratio. If the amount of hydrazine added to the silver salt is less than the above ratio, the reduction of silver ions in the mixed solution will be insufficient, and the yield of plate-like silver particles will deteriorate. On the other hand, when the amount of hydrazine added is larger than the above ratio, the reduction reaction proceeds rapidly, a large amount of spherical silver particles are generated, and the amount of plate-like silver particles produced is reduced.
銀塩及び低分子系分散剤の水溶液に還元剤を添加して混合液を調製した後は、この混合液を２０〜４０℃で１〜１２０時間静置して混合液中の銀イオンを還元反応させることにより、主として形状がプレート状の銀粒子が得られる。混合液の静置は遮光条件下が好ましい。
更に、本発明の製造方法では、上記銀塩、低分子系分散剤及び還元剤の他に、必要に応じて各種添加剤を添加してもよい。具体的にはレベリング剤、消泡剤、スリップ剤、防腐剤等が挙げられる。
After preparing a mixed solution by adding a reducing agent to an aqueous solution of a silver salt and a low molecular weight dispersant, this mixed solution is allowed to stand at 20 to 40 ° C. for 1 to 120 hours to reduce silver ions in the mixed solution. By making it react, the silver particle whose shape is mainly plate-like is obtained. The mixture is preferably left under light shielding conditions.
Furthermore, in the manufacturing method of this invention, you may add various additives as needed other than the said silver salt, a low molecular weight dispersing agent, and a reducing agent. Specific examples include leveling agents, antifoaming agents, slip agents, preservatives, and the like.
本発明の製造方法によれば、粒子径１０〜１０００ｎｍのプレート状銀粒子を水溶液中に分散した状態で得ることができる。得られるプレート状銀粒子の粒子径は、使用する低分子系分散剤の種類や添加量、還元剤の種類や添加量によってその大きさを調整することができる。例えば、低分子系分散剤や還元剤を少量に添加することにより、得られる銀粒子の粒子径は大きくなる傾向があり、低分子系分散剤や還元剤を多量に添加することにより、得られる銀粒子の粒子径は小さくなる傾向がある。なお、本発明の銀粒子の製造方法によれば、プレート状銀粒子とともに球状銀粒子や多面体の銀粒子のような様々な形状の銀粒子が副生成粒子として得られる。この副生成粒子の生成量は、使用する還元剤の種類や添加量を調整することにより増減が可能である。例えば、還元剤の添加量を少量にすることにより、副生成粒子の生成量は減少する傾向があり、還元剤の添加量を多量にすることにより、副生成粒子の生成量は増加する傾向がある。 According to the production method of the present invention, plate-like silver particles having a particle diameter of 10 to 1000 nm can be obtained in a dispersed state in an aqueous solution. The particle size of the obtained plate-like silver particles can be adjusted according to the type and amount of the low molecular dispersant used and the type and amount of the reducing agent. For example, the addition of a low molecular weight dispersant or a reducing agent in a small amount tends to increase the particle diameter of the resulting silver particles, and it can be obtained by adding a large amount of a low molecular weight dispersant or a reducing agent. The particle diameter of silver particles tends to be small. According to the method for producing silver particles of the present invention, silver particles having various shapes such as spherical silver particles and polyhedral silver particles are obtained as by-product particles together with plate-like silver particles. The production amount of the by-product particles can be increased or decreased by adjusting the type and addition amount of the reducing agent to be used. For example, by reducing the amount of reducing agent added, the amount of by-product particles tends to decrease, and by increasing the amount of reducing agent added, the amount of by-product particles tends to increase. is there.
本発明の銀粒子含有組成物は、上記製造方法により得られた銀粒子を含有することを特徴とする。上記製造方法により得られた銀粒子は水溶液中に分散した状態で得られるが、この銀粒子を表面処理することで、水以外の非水系溶媒中にも安定して分散させることができる。非水系溶媒に対して親和性を有する側鎖を備えた非水系分散剤で銀粒子を表面処理することにより、非水系溶媒中に銀粒子が良好に分散した分散液を得ることができる。非水系分散剤としては銀粒子に対して高い吸着性を有する窒素原子や硫黄原子を含有するものが好ましい。窒素原子を含有する分散剤としては、ヘキシルアミン、オクチルアミン、デシルアミン、ドデシルアミン等が挙げられる。また硫黄原子を含有する分散剤としては、例えばブタンチオール、ヘキサンチオール、オクタンチオール、デカンチオール、ドデカンチオール等が挙げられる。このような銀粒子の非水系溶媒分散液は、銀粒子含有組成物の原料として用いることができる。例えば、銀粒子とともに樹脂等のバインダと分散媒とを含有した塗料組成物などを得ることができる。 The silver particle containing composition of this invention contains the silver particle obtained by the said manufacturing method, It is characterized by the above-mentioned. Although the silver particle obtained by the said manufacturing method is obtained in the state disperse | distributed in aqueous solution, it can disperse | distribute stably also in non-aqueous solvents other than water by surface-treating this silver particle. By subjecting the silver particles to surface treatment with a non-aqueous dispersant having a side chain having an affinity for the non-aqueous solvent, a dispersion in which the silver particles are well dispersed in the non-aqueous solvent can be obtained. As the non-aqueous dispersant, those containing nitrogen atoms or sulfur atoms having high adsorptivity to silver particles are preferable. Examples of the dispersant containing a nitrogen atom include hexylamine, octylamine, decylamine, and dodecylamine. Examples of the dispersant containing a sulfur atom include butanethiol, hexanethiol, octanethiol, decanethiol, and dodecanethiol. Such a non-aqueous solvent dispersion of silver particles can be used as a raw material for the silver particle-containing composition. For example, a coating composition containing a binder such as a resin and a dispersion medium together with silver particles can be obtained.
本発明の製造方法により得られる銀粒子の水分散液には、製造の際に使用された低分子系分散剤が含まれており、低分子系分散剤を含んだ状態で銀粒子を回収して導電性材料などの用途に使用すると、低分子系分散剤が絶縁作用を示すため、高い導電性が得られない傾向がある。そのため、銀粒子を製造した後は、水分散液中に含まれる低分子系分散剤を低減ないし除去することが好ましい。銀粒子１００重量部に対して低分子系分散剤５０重量部以下、好ましくは１５重量部以下まで低減させたものが導電性材料として好適であり、低分子系分散剤の割合がそれ以上であると高い導電率が得られず、実用的ではない。製造した銀粒子の水分散液から低分子系分散剤を低減ないし除去する方法としては、凝集による沈降法や遠心分離法などが挙げられる。凝集による沈降法は、例えばｐＨ調整剤や電解質を銀粒子水分散液に所定の割合で添加して銀粒子の分散安定性を減少させ、銀粒子同士を軽く凝集・沈降させて、上澄み液に残存する低分子系分散剤を除去する方法である。この方法では銀粒子水分散液から低分子系分散剤を完全に除去しないため、再分散することが可能である。遠心分離法は、銀粒子水分散液に遠心力をかけて銀粒子を沈降させ、上澄み液に残存する低分子系分散剤を除去する方法である。これらの方法を組合せることによって低分子系分散剤を効率的に低減ないし除去することができる。例えば、低分子系分散剤としてクエン酸三ナトリウムを使用して製造された銀粒子水分散液にｐＨ調整剤として水酸化ナトリウムを添加することで、銀粒子の分散安定性を減少させて銀粒子同士を軽く凝集させ、続いてこの凝集物の沈降スピードを加速するために遠心分離を行い、銀粒子を短時間で沈降させることで、上澄み液に析出・残存するクエン酸三ナトリウムを除去すると同時に、銀粒子の濃縮が可能となる。 The aqueous dispersion of silver particles obtained by the production method of the present invention contains the low molecular weight dispersant used in the production, and the silver particles are recovered in a state containing the low molecular weight dispersant. When used in applications such as conductive materials, the low molecular dispersant exhibits an insulating action, so that high conductivity tends not to be obtained. Therefore, after the silver particles are produced, it is preferable to reduce or remove the low molecular weight dispersant contained in the aqueous dispersion. A low molecular weight dispersant reduced to 50 parts by weight or less, preferably 15 parts by weight or less with respect to 100 parts by weight of silver particles is suitable as the conductive material, and the proportion of the low molecular weight dispersant is more than that. High electrical conductivity cannot be obtained, which is not practical. Examples of the method for reducing or removing the low molecular weight dispersant from the aqueous dispersion of the silver particles produced include a precipitation method by aggregation and a centrifugal separation method. The sedimentation method by agglomeration is, for example, adding a pH adjusting agent or an electrolyte to the silver particle aqueous dispersion at a predetermined ratio to reduce the dispersion stability of the silver particles, and lightly agglomerate and settle the silver particles to form a supernatant. This is a method of removing the remaining low molecular weight dispersant. In this method, since the low molecular weight dispersant is not completely removed from the silver particle aqueous dispersion, it can be redispersed. Centrifugation is a method in which silver particles are precipitated by applying centrifugal force to an aqueous dispersion of silver particles, and the low molecular weight dispersant remaining in the supernatant is removed. By combining these methods, the low molecular weight dispersant can be efficiently reduced or removed. For example, by adding sodium hydroxide as a pH adjuster to a silver particle aqueous dispersion manufactured using trisodium citrate as a low molecular weight dispersant, the dispersion stability of the silver particles is reduced. At the same time as removing trisodium citrate depositing and remaining in the supernatant liquid by lightly aggregating each other and then centrifuging to accelerate the sedimentation speed of the agglomerates and allowing the silver particles to settle in a short time The silver particles can be concentrated.
本発明の製造方法により得られる銀粒子には、プレート状銀粒子だけでなく球状銀粒子等の副生成粒子が混在しているため、この銀粒子を含有する銀粒子含有組成物を用いて塗膜（配線）を形成したとき、形状が球状のみの銀粒子や、プレート状のみの銀粒子よりも粒子間の接触確率が高まり、導電用途などの場合は比抵抗値が低くなるといった利点がある。 Since the silver particles obtained by the production method of the present invention contain not only plate-like silver particles but also by-product particles such as spherical silver particles, coating is performed using a silver particle-containing composition containing these silver particles. When a film (wiring) is formed, there is an advantage that the contact probability between particles is higher than that of silver particles having only a spherical shape or silver particles having only a plate shape, and the specific resistance value is lowered in the case of conductive use. .
本発明の製造方法により得られた銀粒子は、低分子系分散剤を使用して製造しているため、銀粒子水分散液に用途に応じて選定した適切な分散剤を更に添加することで銀粒子への表面修飾が容易に可能となる。例えば、導電性用途の場合、加熱すると揮発するような分散剤を添加すると低温焼結が可能となり、かつ分散安定性が向上した導電性ペーストが得られる。このような分散剤としては、アミノ基やチオール基、カルボキシル基を有する低分子化合物を使用することが好適である。 Since the silver particles obtained by the production method of the present invention are produced using a low molecular weight dispersant, an appropriate dispersant selected according to the use can be further added to the silver particle aqueous dispersion. Surface modification to silver particles can be easily performed. For example, in the case of conductive use, if a dispersant that volatilizes when heated is added, low temperature sintering becomes possible and a conductive paste with improved dispersion stability can be obtained. As such a dispersant, it is preferable to use a low molecular compound having an amino group, a thiol group, or a carboxyl group.
本発明の製造方法により得られた銀粒子は、適当な分散剤によって表面処理し、これに分散媒、バインダを加えた銀粒子含有組成物として利用することができる。バインダとしては、通常塗料用や成形用に利用されている可視光線から近赤外光領域の光に対して透過性がある各種樹脂が特に制限無く使用できる。例えば、アクリル樹脂、ポリエステル樹脂、アルキド樹脂、ウレタン樹脂、シリコーン樹脂、フッ素樹脂、エポキシ樹脂、ポリカーボネート樹脂、ポリ塩化ビニル樹脂、ポリビニルアルコール等の有機樹脂や、ラジカル重合性のオリゴマーやモノマー（必要に応じて硬化剤やラジカル重合剤開始剤を併用してもよい。）、アルコキシシランを樹脂骨格に用いたゾルゲル溶液などが代表的なものとして挙げられる。 The silver particles obtained by the production method of the present invention can be used as a silver particle-containing composition in which a surface treatment is performed with an appropriate dispersant and a dispersion medium and a binder are added thereto. As the binder, various resins that are normally transmissive for visible light to near infrared light, which are used for paints and moldings, can be used without any particular limitation. For example, acrylic resins, polyester resins, alkyd resins, urethane resins, silicone resins, fluororesins, epoxy resins, polycarbonate resins, polyvinyl chloride resins, polyvinyl alcohol, and other organic resins, radical polymerizable oligomers and monomers (if necessary Typical examples include a sol-gel solution using an alkoxysilane as a resin skeleton.
上記銀粒子含有組成物において、必要に応じて配合する溶媒としては、バインダが溶解若しくは安定に分散するようなものを適宜選択すればよい。具体的には、水の他に、メタノール、エタノール、プロパノール、ヘキサノール、エチレングリコール、α−テルピネオール等のアルコール、エチレングリコール等のグリコール、デカン、テレピン油等の炭化水素、キシレン、トルエン等の芳香族炭化水素、シクロヘキサン等の脂環式炭化水素、アセトン、メチルエチルケトン、メチルイソブチルケトン等のケトン類、酢酸エチル、酢酸ブチル等のエステル類、エチレングリコールモノブチルエーテル等のエーテル類、あるいはこれらの混合物が代表的なものとして挙げられる。なお、溶媒は上記列挙したものには限定されず、バインダが溶解若しくは安定に分散するようなものであれば、従来より知られている溶媒を使用することが可能である。 In the silver particle-containing composition, as the solvent to be blended as necessary, a solvent in which the binder is dissolved or stably dispersed may be appropriately selected. Specifically, in addition to water, alcohols such as methanol, ethanol, propanol, hexanol, ethylene glycol and α-terpineol, glycols such as ethylene glycol, hydrocarbons such as decane and turpentine oil, and aromatics such as xylene and toluene Typical examples include hydrocarbons, cycloaliphatic hydrocarbons such as cyclohexane, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, ethers such as ethylene glycol monobutyl ether, and mixtures thereof. It is mentioned as a thing. The solvent is not limited to those listed above, and conventionally known solvents can be used as long as the binder is dissolved or stably dispersed.
上記銀粒子含有組成物において、銀粒子の含有量はバインダ１００重量部に対して０．１〜１００００重量部が適当であり、好ましくは、導電性用途であればバインダ１００重量部に対して５５０〜９９００重量部がよい。銀粒子の添加量が下限値未満では、バインダによる絶縁効果の影響が大きくなり、高い導電特性が得られ難い。一方、銀粒子の添加量が上限値を越えると、銀粒子同士の凝集が起こり易くなるため保存安定性が低下する。 In the silver particle-containing composition, the content of silver particles is suitably 0.1 to 10,000 parts by weight with respect to 100 parts by weight of the binder, preferably 550 with respect to 100 parts by weight of the binder for conductive use. ~ 9900 parts by weight are preferred. If the amount of silver particles added is less than the lower limit, the influence of the insulating effect by the binder becomes large, and it is difficult to obtain high conductive properties. On the other hand, when the addition amount of silver particles exceeds the upper limit value, aggregation of silver particles tends to occur, so that storage stability is lowered.
本発明の銀粒子含有組成物は、目的に応じて、染料、顔料、蛍光体、金属酸化物、球状金属粒子及びロッド状金属粒子（金属ナノロッド）からなる群より選ばれた１種又は２種以上を更に添加してもよい。また必要に応じてレべリング剤、消泡剤その他の各種添加剤を添加してもよい。 The silver particle-containing composition of the present invention is one or two selected from the group consisting of a dye, a pigment, a phosphor, a metal oxide, a spherical metal particle, and a rod-shaped metal particle (metal nanorod) depending on the purpose. The above may be further added. Moreover, you may add a leveling agent, an antifoamer, and other various additives as needed.
本発明の銀粒子含有組成物は、塗料組成物、塗膜、フィルム又は板材など多様な形態で用いることができ、この組成物によって形成された塗膜を有する基材を得ることができる。例えば、電磁波を遮蔽したい基材に直接に塗布若しくは印刷し、電磁波遮蔽フィルタを形成することができる。また、本発明の組成物をフィルム状や板状等に形成して、形成した組成物を電磁波遮蔽したい基材に積層したり、基材を包囲してもよい。また、本発明の組成物によって形成した上記塗膜やフィルムなどの形成物を基材に積層させて積層体を形成し、積層体を電磁波遮蔽フィルタとして電磁波を遮蔽したい基材に更に積層若しくは包囲して用いてもよい。上記各使用形態において、フィルタの厚さは、概ね０．０１μｍ〜１ｍｍが適当であり、コストや光透過性等を考慮すると０．１μｍ〜２００μｍが好ましい。本発明の銀粒子含有組成物によって形成した塗膜やフィルム、板材などをフィルタ層として有するものは、例えば、配線、電磁波遮蔽フィルタなどの導電率に優れた基材、フィルタとして用いることができる。 The silver particle containing composition of this invention can be used with various forms, such as a coating composition, a coating film, a film, or a board | plate material, and can obtain the base material which has the coating film formed with this composition. For example, an electromagnetic wave shielding filter can be formed by directly applying or printing on a base material to be shielded from electromagnetic waves. Further, the composition of the present invention may be formed into a film shape, a plate shape, or the like, and the formed composition may be laminated on a base material to be shielded against electromagnetic waves, or the base material may be surrounded. In addition, a laminate is formed by laminating a formation such as the above-described coating film or film formed by the composition of the present invention on a substrate, and the laminate is further laminated or enclosed as a substrate for shielding electromagnetic waves as an electromagnetic wave shielding filter. May be used. In each of the above usage forms, the thickness of the filter is suitably about 0.01 μm to 1 mm, and preferably 0.1 μm to 200 μm in view of cost, light transmittance, and the like. What has a coating film, a film, a board | plate material, etc. which were formed with the silver particle containing composition of this invention as a filter layer can be used as a base material and a filter excellent in electrical conductivity, such as a wiring and an electromagnetic wave shielding filter, for example.
本発明の製造方法により得られた銀粒子は、高い耐熱性、耐候性、耐薬品性、特定波長吸収能を有するので、光学フィルタ、着色剤、化粧品、近赤外線吸収剤、偽造防止インク、表面増強蛍光センサ用増感剤、生体マーカ、ＤＤＳ用薬物保持体、バイオセンサ、ＤＮＡチップ、検査薬、ラマン増強用試薬などの材料として好適である。また、銀は高い導電性を示すことから配線材料、電極材料、電磁波シールド材として使用可能である。この他に、形状異方性に基づいて記録素子として使用可能である。更に、粒子で表面積が大きいので、触媒反応の場を提供する材料として好適である。なお、触媒やラマン増強用試薬など、銀粒子表面に目的物質が吸着するような用途では、製造で使用した低分子系分散剤を極力低減させてから使用することが好ましい。 Since the silver particles obtained by the production method of the present invention have high heat resistance, weather resistance, chemical resistance, and specific wavelength absorption ability, optical filters, colorants, cosmetics, near infrared absorbers, anti-counterfeit inks, surface It is suitable as a material for sensitizers for enhanced fluorescence sensors, biomarkers, drug holders for DDS, biosensors, DNA chips, test agents, Raman enhancement reagents, and the like. Moreover, since silver shows high electroconductivity, it can be used as a wiring material, an electrode material, and an electromagnetic wave shielding material. In addition, it can be used as a recording element based on shape anisotropy. Furthermore, since the particles have a large surface area, they are suitable as materials for providing a field for catalytic reaction. In applications where the target substance is adsorbed on the surface of silver particles, such as a catalyst or a Raman enhancing reagent, it is preferable to use the low molecular weight dispersant used in the production after reducing it as much as possible.
次に本発明の実施例を比較例とともに詳しく説明する。
＜実施例１＞
先ず、銀塩を溶解した水溶液として１０ｍＭ濃度の硝酸銀水溶液６０００μｌ（６０μｍｏｌ）を、低分子系分散剤を溶解した水溶液として１００ｍＭ濃度のクエン酸三ナトリウム水溶液１０００μｌ（１００μｍｏｌ）を、還元剤を溶解した水溶液として４０ｍＭ濃度のジメチルアミンボラン水溶液２５００μｌ（１００μｍｏｌ）をそれぞれ用意した。次いで、低分子系分散剤を溶解した水溶液を水５０ｍｌに添加して希釈し、更に銀塩が溶解した水溶液を添加して銀塩及び低分子系分散剤の水溶液を調製した。次に、銀塩及び低分子系分散剤の水溶液に還元剤を溶解した水溶液を攪拌しながら添加して混合液を調製し、１０分間攪拌し続けた後、この混合液を遮光条件下、３０℃で静置した状態で４８時間保管することにより銀粒子を製造した。得られた銀粒子には粒子径が１０〜５０ｎｍのプレート状の銀粒子が含まれていた。またプレート状銀粒子以外には球状銀粒子や多面体の銀粒子のような様々な形状の銀粒子が副生成粒子として形成されていた。
Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
First, 6000 μl (60 μmol) of a 10 mM silver nitrate aqueous solution as an aqueous solution in which a silver salt is dissolved, 1000 μl (100 μmol) of a 100 mM trisodium citrate aqueous solution as an aqueous solution in which a low molecular weight dispersant is dissolved, and an aqueous solution in which a reducing agent is dissolved. As a sample, 2500 μl (100 μmol) of a 40 mM dimethylamine borane aqueous solution was prepared. Next, an aqueous solution in which a low molecular weight dispersant was dissolved was added to 50 ml of water to dilute, and an aqueous solution in which a silver salt was dissolved was further added to prepare an aqueous solution of a silver salt and a low molecular weight dispersant. Next, an aqueous solution in which a reducing agent is dissolved in an aqueous solution of a silver salt and a low molecular weight dispersant is added with stirring to prepare a mixed solution. After stirring for 10 minutes, the mixed solution is subjected to light shielding conditions under 30 conditions. Silver particles were produced by storing for 48 hours in a state of standing at ℃. The obtained silver particles contained plate-like silver particles having a particle diameter of 10 to 50 nm. In addition to the plate-like silver particles, various shaped silver particles such as spherical silver particles and polyhedral silver particles were formed as by-product particles.
＜実施例２＞
還元剤を溶解した水溶液として１０重量％濃度のヒドラジン水溶液２５μｌ（５０μｍｏｌ）を用いた以外は、実施例１と同様の条件で銀粒子を製造した。得られた銀粒子には粒子径が１０〜５０ｎｍのプレート状の銀粒子が含まれていた。またプレート状銀粒子以外には球状銀粒子や多面体の銀粒子のような様々な形状の銀粒子が副生成粒子として形成されていた。
＜実施例３＞
低分子系分散剤を溶解した水溶液として１００ｍＭ濃度のクエン酸１０００μｌ（１００μｍｏｌ）を、還元剤を溶解した水溶液として４０ｍＭ濃度のジメチルアミンボラン２５０００μｌ（１０００μｌ）を用いた以外は、実施例１と同様の条件で銀粒子を製造した。得られた銀粒子には粒子径が３０〜６０ｎｍのプレート状の銀粒子が含まれていた。またプレート状銀粒子以外には球状銀粒子や多面体の銀粒子のような様々な形状の銀粒子が副生成粒子として形成されていた。
<Example 2>
Silver particles were produced under the same conditions as in Example 1 except that 25 μl (50 μmol) of a 10% strength by weight hydrazine aqueous solution was used as the aqueous solution in which the reducing agent was dissolved. The obtained silver particles contained plate-like silver particles having a particle diameter of 10 to 50 nm. In addition to the plate-like silver particles, various shaped silver particles such as spherical silver particles and polyhedral silver particles were formed as by-product particles.
<Example 3>
Example 1 except that 1000 μl (100 μmol) of 100 mM citric acid was used as the aqueous solution in which the low molecular weight dispersant was dissolved, and 25000 μl (1000 μl) of dimethylamine borane at 40 mM concentration was used as the aqueous solution in which the reducing agent was dissolved. Silver particles were produced under the conditions. The obtained silver particles contained plate-like silver particles having a particle size of 30 to 60 nm. In addition to the plate-like silver particles, various shaped silver particles such as spherical silver particles and polyhedral silver particles were formed as by-product particles.
＜実施例４＞
低分子系分散剤を溶解した水溶液として１００ｍＭ濃度のリンゴ酸１０００μｌ（１００μｍｏｌ）を用いた以外は、実施例３と同様の条件で銀粒子を製造した。得られた銀粒子には粒子径が３０〜６０ｎｍのプレート状の銀粒子が含まれていた。またプレート状銀粒子以外には球状銀粒子や多面体の銀粒子のような様々な形状の銀粒子が副生成粒子として形成されていた。
＜実施例５＞
低分子系分散剤を溶解した水溶液として１００ｍＭ濃度の酒石酸１０００μｌ（１００μｍｏｌ）を用いた以外は、実施例３と同様の条件で銀粒子を製造した。得られた銀粒子には粒子径が３０〜６０ｎｍのプレート状の銀粒子が含まれていた。またプレート状銀粒子以外には球状銀粒子や多面体の銀粒子のような様々な形状の銀粒子が副生成粒子として形成されていた。
＜実施例６＞
低分子系分散剤を溶解した水溶液として１００ｍＭ濃度のコハク酸１０００μｌ（１００μｍｏｌ）を用いた以外は、実施例３と同様の条件で銀粒子を製造した。得られた銀粒子には粒子径が３０〜６０ｎｍのプレート状の銀粒子が含まれていた。またプレート状銀粒子以外には球状銀粒子や多面体の銀粒子のような様々な形状の銀粒子が副生成粒子として形成されていた。
<Example 4>
Silver particles were produced under the same conditions as in Example 3 except that 1000 μl (100 μmol) of 100 mM malic acid was used as an aqueous solution in which a low molecular weight dispersant was dissolved. The obtained silver particles contained plate-like silver particles having a particle size of 30 to 60 nm. In addition to the plate-like silver particles, various shaped silver particles such as spherical silver particles and polyhedral silver particles were formed as by-product particles.
<Example 5>
Silver particles were produced under the same conditions as in Example 3 except that 1000 μl (100 μmol) of tartaric acid having a concentration of 100 mM was used as the aqueous solution in which the low molecular dispersant was dissolved. The obtained silver particles contained plate-like silver particles having a particle size of 30 to 60 nm. In addition to the plate-like silver particles, various shaped silver particles such as spherical silver particles and polyhedral silver particles were formed as by-product particles.
<Example 6>
Silver particles were produced under the same conditions as in Example 3, except that 1000 μl (100 μmol) of succinic acid having a concentration of 100 mM was used as the aqueous solution in which the low molecular dispersant was dissolved. The obtained silver particles contained plate-like silver particles having a particle size of 30 to 60 nm. In addition to the plate-like silver particles, various shaped silver particles such as spherical silver particles and polyhedral silver particles were formed as by-product particles.
＜比較例１＞
低分子系分散剤を溶解した水溶液として１０００ｍＭ濃度のクエン酸三ナトリウム５０００μｌ（５０００μｍｏｌ）を用いた以外は、実施例１と同様の条件で銀粒子を製造した。得られた銀粒子には粒子径が１０〜３０ｎｍの球状銀粒子が形成されており、プレート状銀粒子は存在していなかった。
＜比較例２＞
低分子系分散剤であるクエン酸三ナトリウムを添加しない以外は、実施例１と同様の条件で銀粒子を製造した。得られた銀粒子は低分子系分散剤が入っていないため凝集し、塊状沈降物が観察された。
<Comparative Example 1>
Silver particles were produced under the same conditions as in Example 1, except that 5000 μl (5000 μmol) of trisodium citrate having a concentration of 1000 mM was used as the aqueous solution in which the low molecular weight dispersant was dissolved. In the obtained silver particles, spherical silver particles having a particle diameter of 10 to 30 nm were formed, and no plate-like silver particles were present.
<Comparative example 2>
Silver particles were produced under the same conditions as in Example 1 except that trisodium citrate, which is a low molecular weight dispersant, was not added. Since the obtained silver particles did not contain a low molecular weight dispersant, they aggregated and a massive sediment was observed.
＜比較試験１＞
実施例１〜６及び比較例１，２における銀粒子の製造条件を次の表１に示す。また、透過型電子顕微鏡（ＴＥＭ）により撮影した実施例２で得られた銀粒子の写真を図１（ａ）及び図１（ｂ）に、ＴＥＭにより撮影した実施例３で得られた銀粒子の写真を図２（ａ）、図２（ｂ）にそれぞれ示す。なお、図１（ｂ）、図２（ｂ）は図１（ａ）、図２（ａ）の部分拡大図である。また、実施例１〜３及び比較例１で得られた銀粒子水分散液を所定の割合で水で希釈して希釈液を調製し、この希釈液に対して分光光度計（Ｖ−５７０；日本分光社製）を用いて３００〜８００ｎｍにおける波長吸収特性を測定した。その結果を図３及び図４に示す。
<Comparison test 1>
The production conditions of the silver particles in Examples 1 to 6 and Comparative Examples 1 and 2 are shown in Table 1 below. Moreover, the silver particle obtained in Example 3 image | photographed by TEM to the photograph of the silver particle obtained in Example 2 image | photographed with the transmission electron microscope (TEM) in FIG. 1 (a) and FIG.1 (b). These photographs are shown in FIG. 2 (a) and FIG. 2 (b), respectively. FIGS. 1B and 2B are partially enlarged views of FIGS. 1A and 2A. Moreover, the silver particle aqueous dispersion obtained in Examples 1 to 3 and Comparative Example 1 was diluted with water at a predetermined ratio to prepare a diluted solution, and a spectrophotometer (V-570; (Manufactured by JASCO Corporation) was used to measure the wavelength absorption characteristics at 300 to 800 nm. The results are shown in FIGS.
図１（ａ）、図１（ｂ）及び図２（ａ）、図２（ｂ）より明らかなように、水分散液中にはプレート状の銀粒子と球状の銀粒子の双方が分散した状態で存在していた。
図４から明らかなように、比較例１の銀粒子では、４００ｎｍ付近の波長でシャープな吸収が観察されていた。４００ｎｍ付近での吸収は球状銀粒子による吸収を示している。一方図３から明らかなように、実施例１〜３の銀粒子では、４００ｎｍ付近の波長だけでなく、４００ｎｍ付近より長波長側にも吸収が観察されていた。４００ｎｍ付近より長波長側でのプラズモン吸収はプレートの辺の長さに応じた吸収が得られていることを示している。これは実施例１〜３で得られた銀粒子には、球状銀粒子とプレート状銀粒子の双方が含まれていることを裏付けるものである。また実施例１〜３では、４００ｎｍ付近より長波長側でのプラズモン吸収波長に違いがあることから、製造条件の違いによって異なる大きさのプレート状銀粒子が製造されることが判った。
As is clear from FIGS. 1A, 1B, 2A, and 2B, both plate-like silver particles and spherical silver particles are dispersed in the aqueous dispersion. Existed in a state.
As is clear from FIG. 4, the silver particles of Comparative Example 1 were observed to have sharp absorption at a wavelength near 400 nm. Absorption around 400 nm indicates absorption by spherical silver particles. On the other hand, as is clear from FIG. 3, in the silver particles of Examples 1 to 3, absorption was observed not only at a wavelength near 400 nm but also at a longer wavelength side near 400 nm. Plasmon absorption on the longer wavelength side from around 400 nm indicates that absorption according to the length of the side of the plate is obtained. This confirms that the silver particles obtained in Examples 1 to 3 contain both spherical silver particles and plate-like silver particles. Moreover, in Examples 1-3, since there was a difference in the plasmon absorption wavelength on the long wavelength side from around 400 nm, it was found that plate-like silver particles having different sizes were produced depending on the production conditions.
＜実施例７＞
先ず、実施例２で製造した銀粒子水分散液を１２０００ｒｐｍで遠心分離し、分散液中の上澄み液を除去して２重量％の銀粒子濃縮水分散液とした。次いで、６重量％ポリビニルアルコール水溶液１．０ｇ中に濃縮した分散液を０．５ｇ添加して塗料化した。次に、この塗料をバーコーターを用いてガラス板表面に塗布し、塗布したガラス板を６０℃で３０分間乾燥しガラス板表面に塗膜を形成した。得られた塗膜は赤色を呈し、約５５０ｎｍの波長を吸収した。
＜実施例８＞
先ず、実施例２で製造した銀粒子水分散液を１２０００ｒｐｍで遠心分離し、分散液中の上澄み液を除去して２重量％の銀粒子濃縮水分散液とした。次いで、濃縮した分散液１．０ｇ中にエチレングリコール０．５ｇを添加しペースト化した。次に、このペーストをバーコーターを用いてガラス板表面に塗布し、塗布したガラス板を２５０℃で３０分間乾燥しガラス板表面に塗膜を形成した。得られた塗膜の比抵抗値を４端針法の抵抗率計（ロレスタＧＰ；三菱化学社製）によって測定したところ、８×１０-6Ω・ｃｍと高い導電性が得られた。これは塗膜を形成する銀粒子がプレート状銀粒子だけでなく、球状銀粒子等の副生成粒子が混在して、各粒子間の接触確率が高まっているためと考えられる。
<Example 7>
First, the silver particle aqueous dispersion produced in Example 2 was centrifuged at 12000 rpm, and the supernatant in the dispersion was removed to obtain a 2% by weight silver particle concentrated aqueous dispersion. Next, 0.5 g of a dispersion liquid concentrated in 1.0 g of a 6% by weight aqueous polyvinyl alcohol solution was added to form a paint. Next, this paint was applied to the surface of the glass plate using a bar coater, and the applied glass plate was dried at 60 ° C. for 30 minutes to form a coating film on the surface of the glass plate. The obtained coating film was red and absorbed a wavelength of about 550 nm.
<Example 8>
First, the silver particle aqueous dispersion produced in Example 2 was centrifuged at 12000 rpm, and the supernatant in the dispersion was removed to obtain a 2% by weight silver particle concentrated aqueous dispersion. Next, 0.5 g of ethylene glycol was added to 1.0 g of the concentrated dispersion to form a paste. Next, this paste was applied to the glass plate surface using a bar coater, and the applied glass plate was dried at 250 ° C. for 30 minutes to form a coating film on the glass plate surface. When the resistivity value of the obtained coating film was measured by a resistivity meter (Loresta GP; manufactured by Mitsubishi Chemical Corporation) using a four-end needle method, a high conductivity of 8 × 10 −6 Ω · cm was obtained. This is presumably because the silver particles forming the coating film contain not only plate-like silver particles but also by-product particles such as spherical silver particles, and the contact probability between the particles is increased.
Claims (7)
前記銀塩と低分子系分散剤と還元剤の添加割合がモル比率で銀塩：低分子系分散剤：還元剤＝１：（０．１〜１００）：（０．００１〜１００）であることを特徴とする銀粒子の製造方法。 A silver salt and a low molecular weight dispersant are added to water to prepare an aqueous solution of a silver salt and a low molecular weight dispersant, a reducing agent is added to the aqueous solution at a predetermined ratio to prepare a mixed solution, and the mixed solution is It is a method of producing silver particles mainly having a plate shape by allowing the silver ions in the mixed solution to undergo a reduction reaction by standing at 20 to 40 ° C.,
The silver salt, the low molecular weight dispersant, and the reducing agent are added at a molar ratio of silver salt: low molecular weight dispersant: reducing agent = 1: (0.1-100) :( 0.001-100). A method for producing silver particles.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002013999A1 (en) * | 2000-08-11 | 2002-02-21 | Ishihara Sangyo Kaisha, Ltd. | Colloidal metal solution, process for producing the same, and coating material containing the same |
| JP2005015647A (en) * | 2003-06-26 | 2005-01-20 | Sumitomo Osaka Cement Co Ltd | Coating material for forming metal thin film, metal thin film, and its preparation method |
| JP2005105376A (en) * | 2003-09-30 | 2005-04-21 | Sumitomo Osaka Cement Co Ltd | Silver fine particle and its production method |
-
2005
- 2005-11-18 JP JP2005333533A patent/JP2007138249A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002013999A1 (en) * | 2000-08-11 | 2002-02-21 | Ishihara Sangyo Kaisha, Ltd. | Colloidal metal solution, process for producing the same, and coating material containing the same |
| JP2005015647A (en) * | 2003-06-26 | 2005-01-20 | Sumitomo Osaka Cement Co Ltd | Coating material for forming metal thin film, metal thin film, and its preparation method |
| JP2005105376A (en) * | 2003-09-30 | 2005-04-21 | Sumitomo Osaka Cement Co Ltd | Silver fine particle and its production method |
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