JP5580153B2 - Metal fine particle dispersion, metal fine particle, production method of metal fine particle dispersion, etc. - Google Patents

Metal fine particle dispersion, metal fine particle, production method of metal fine particle dispersion, etc. Download PDF

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JP5580153B2
JP5580153B2 JP2010211155A JP2010211155A JP5580153B2 JP 5580153 B2 JP5580153 B2 JP 5580153B2 JP 2010211155 A JP2010211155 A JP 2010211155A JP 2010211155 A JP2010211155 A JP 2010211155A JP 5580153 B2 JP5580153 B2 JP 5580153B2
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光章 熊澤
俊晴 平井
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JGC Catalysts and Chemicals Ltd
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Catalysts and Chemicals Industries Co Ltd
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本発明は、金属微粒子の０．１〜３０重量％が酸化されていることにより優れた導電性を有するとともに分散安定性に優れ、導電性被膜中でイオン化や粒子成長などが生じにくい金属微粒子分散液、この金属微粒子分散液に含まれる金属微粒子、この金属微粒子の製造方法、前記金属部粒子分散液を含むポットライフの長い透明導電性被膜形成用塗布液、このような透明導電性被膜形成用塗布液を用いて得られる帯電防止性、電磁遮蔽性および信頼性や耐久性に優れた透明導電性被膜付基材に関する。   In the present invention, the metal fine particle dispersion has excellent conductivity as well as excellent dispersion stability due to oxidation of 0.1 to 30% by weight of the metal fine particles, and does not easily cause ionization or particle growth in the conductive film. Liquid, metal fine particles contained in the metal fine particle dispersion, a method for producing the metal fine particles, a coating liquid for forming a transparent conductive film having a long pot life containing the metal part particle dispersion, and for forming such a transparent conductive film The present invention relates to a substrate with a transparent conductive film excellent in antistatic properties, electromagnetic shielding properties, reliability and durability obtained using a coating solution.

従来より、プラズマディスプレイ、液晶表示装置、陰極線管、蛍光表示管、などの表示パネルのような透明基材の表面の帯電防止および反射防止を目的として、これらの表面に帯電防止機能および反射防止機能を有する透明被膜を形成することが行われていた。ところで、プラズマディスプレイや陰極線管などから放出される電磁波が人体に及ぼす影響が最近問題にされており、従来の帯電防止、反射防止に加えてこれらの電磁波および電磁波の放出に伴って形成される電磁場を遮蔽することが望まれている。   Conventionally, antistatic and antireflection functions have been applied to the surfaces of transparent substrates such as plasma displays, liquid crystal display devices, cathode ray tubes, and fluorescent display tubes for the purpose of antistatic and antireflection. The formation of a transparent film having By the way, the influence of electromagnetic waves emitted from plasma displays, cathode ray tubes, etc. on the human body has recently become a problem, and in addition to conventional anti-static and anti-reflective measures, the electromagnetic field formed by the emission of these electromagnetic waves and electromagnetic waves. It is desirable to shield.

これらの電磁波などを遮蔽する方法の一つとして、陰極線管などの表示パネルの表面に電磁波遮断用の導電性被膜を形成する方法がある。しかしながら、従来の帯電防止用導電性被膜であれば表面抵抗が少なくとも１０７Ω／□程度の表面抵抗を有していれば十分であるのに対し、電磁遮蔽用の導電性被膜では１０２〜１０４Ω／□のような低い表面抵抗を有すあああることが必要であった。 One method of shielding these electromagnetic waves and the like is a method of forming a conductive film for shielding electromagnetic waves on the surface of a display panel such as a cathode ray tube. However, a conventional antistatic conductive film having a surface resistance of at least about 10 7 Ω / □ is sufficient, whereas a conductive film for electromagnetic shielding is 10 2 to It was necessary to have a low surface resistance such as 10 4 Ω / □.

このように表面抵抗の低い導電性被膜を、従来のＳbドープ酸化錫またはＳnドープ酸化インジウムのような導電性酸化物を含む塗布液を用いて形成しようとすると、従来の帯電防止性被膜の場合よりも膜厚を厚くする必要があった。しかしながら、導電性被膜の膜厚は、１０〜２００ｎｍ程度にしないと反射防止効果は発現しないため、従来のＳbドープ酸化錫またはＳnドープ酸化インジウムのような導電性酸化物では、表面抵抗が低く電磁波遮断性に優れるとともに反射防止性にも優れた導電性被膜を得ることが困難であるという問題があった。   When the conductive film having a low surface resistance is formed by using a coating solution containing a conductive oxide such as conventional Sb-doped tin oxide or Sn-doped indium oxide, It was necessary to increase the film thickness. However, since the antireflection effect is not manifested unless the film thickness of the conductive film is about 10 to 200 nm, conventional conductive oxides such as Sb-doped tin oxide or Sn-doped indium oxide have low surface resistance and electromagnetic waves. There has been a problem that it is difficult to obtain a conductive film that has excellent blocking properties and antireflection properties.

また、低表面抵抗の導電性被膜を形成する方法の一つとして、Ａｇなどの金属微粒子を含む導電性被膜形成用塗布液を用いて基材の表面に金属微粒子含有被膜を形成する方法がある。この方法では、金属微粒子含有被膜形成用塗布液として、コロイド状の金属微粒子が極性溶媒に分散したものが用いられている。このような塗布液では、コロイド状金属微粒子の分散性、安定性を向上させるために、金属微粒子表面がポリビニルアルコール、ポリビニルピロリドンまたはゼラチンなどの有機系安定化剤で表面処理されている。   Further, as one method for forming a conductive film having a low surface resistance, there is a method of forming a metal fine particle-containing film on the surface of a substrate using a coating liquid for forming a conductive film containing metal fine particles such as Ag. . In this method, a coating solution in which colloidal metal fine particles are dispersed in a polar solvent is used as a coating solution for forming a coating containing metal fine particles. In such a coating solution, the surface of the metal fine particles is surface-treated with an organic stabilizer such as polyvinyl alcohol, polyvinyl pyrrolidone or gelatin in order to improve the dispersibility and stability of the colloidal metal fine particles.

しかしながら、このような金属微粒子含有被膜形成用塗布液を用いて形成された導電性被膜は、被膜中で金属微粒子同士が安定化剤を介して接触するため、粒界抵抗が大きく、被膜の表面抵抗が低くならないことがあった。このため、製膜後、４００℃程度の高温で焼成して安定化剤を分解除去する必要があるが、安定化剤の分解除去をするため高温で焼成すると、金属微粒子同士の融着や凝集が起こり、導電性被膜の透明性やヘーズが低下するという問題があった。また、陰極線管などの場合は、高温に晒すと劣化してしまうという問題もあった。   However, the conductive coating formed using such a coating solution for forming a coating containing metal fine particles has a large intergranular resistance because the metal fine particles come into contact with each other through a stabilizer in the coating, and the surface of the coating is Resistance sometimes did not become low. For this reason, after film formation, it is necessary to decompose and remove the stabilizer by baking at a high temperature of about 400 ° C. However, if the baking is performed at a high temperature to decompose and remove the stabilizer, the metal fine particles are fused or aggregated. Occurs, and the transparency and haze of the conductive film are reduced. In the case of a cathode ray tube or the like, there is a problem that the cathode ray tube deteriorates when exposed to a high temperature.

さらに従来のＡｇ等の金属微粒子を含む透明導電性被膜では、金属が酸化されたり、イオン化により粒子成長したり、また場合によっては腐食が発生することがあり、塗膜の導電性や光透過率が低下し、表示装置が信頼性を欠くという問題があった。また、本願出願人は、たとえば、特開平１０−１８８６８１号公報で、２種以上の金属からなる平均粒子径が１〜２００ｎｍの複合金属微粒子を含む透明導電性被膜形成用塗布液を提案しているが、このような、複合金属微粒子では、ポットライフの充分に長い塗布液を得ることは困難であった。   Furthermore, in the conventional transparent conductive film containing fine metal particles such as Ag, the metal may be oxidized, the particles may grow due to ionization, and corrosion may occur in some cases. As a result, there was a problem that the display device lacked reliability. The applicant of the present application has proposed a coating liquid for forming a transparent conductive film containing composite metal fine particles having an average particle diameter of 1 to 200 nm made of two or more kinds of metals, for example, in JP-A-10-188681. However, with such composite metal fine particles, it has been difficult to obtain a coating solution having a sufficiently long pot life.

たとえば、特開２０００２−２９４３０１号公報で、鉄と鉄以外の金属とを含む金属微粒子を含む透明導電性被膜形成用塗布液を提供しているが、このような金属微粒子では、粒子の表面電荷量が高くポットライフの充分に長い塗布液を得ることは困難であった。   For example, in Japanese Patent Application Laid-Open No. 2000-294301, a coating liquid for forming a transparent conductive film containing metal fine particles containing iron and a metal other than iron is provided. It was difficult to obtain a coating solution having a high amount and a sufficiently long pot life.

しかしながら、特開平１０−１８８６８１や特開２０００２−２９４３０１号公報の方式でもＡｇ等の金属微粒子は、酸化は抑制できていない点も有り、薄膜を形成した際、空気中の酸素の影響で酸化されたり、透明被膜形成の際に透明被膜形成塗布液中の酸の影響で、金属酸化が促進されたり、イオン化により粒子成長したり、また場合によっては腐食が発生することがあった。   However, even in the methods disclosed in JP-A-10-188681 and JP-A-2000-294301, the oxidation of metal fine particles such as Ag cannot be suppressed. When a thin film is formed, it is oxidized by the influence of oxygen in the air. During the formation of the transparent film, the oxidation of the metal is promoted due to the influence of the acid in the coating liquid for forming the transparent film, the particles grow due to ionization, and in some cases, corrosion occurs.

特開平１０−１８８６８１号公報Japanese Patent Laid-Open No. 10-188681 特開２００２−２９４３０１号公報JP 2002-294301 A

本発明は、１０２〜１０４Ω／□程度の低い表面抵抗を有し、帯電防止性、反射防止性および電磁遮蔽性に優れるとともに、分散液のポットライフが長く、信頼性や耐久性に優れた透明導電性被膜の形成に好適に用いることができる金属微粒子分散液、金属微粒子、金属微粒子の製造方法、透明導電性被膜形成用塗布液及びを提供することを目的としている。 The present invention has a low surface resistance of about 10 2 to 10 4 Ω / □, is excellent in antistatic property, antireflection property and electromagnetic shielding property, has a long pot life of the dispersion, and is reliable and durable. An object of the present invention is to provide a metal fine particle dispersion, metal fine particles, a method for producing metal fine particles, a coating liquid for forming a transparent conductive film, and a coating liquid for forming a transparent conductive film, which can be suitably used for forming an excellent transparent conductive film.

本願発明者らは、金属微粒子についてさらに検討した結果、金属微粒子の一次粒子の範囲を１〜３０ｎｍにしかつ二次粒子径を５〜１００ｎｍに制御し、この金属微粒子の０．１〜３０重量％が酸化され、金属微粒子分散液の微粒子の濃度が０．５重量％のときの表面電荷量が０．５〜４５μeq/gの範囲であり、電気伝導度が１〜１５μＳ／ｃｍの範囲であるときに金属微粒子分散液及び透明導電性被膜形成用塗布液の安定性が増大し、高温領域でも酸化が抑制されることを見出し、耐久性に優れた透明導電性被膜が得られることを見出して本願発明を完成するに至った。   The inventors of the present application further studied the metal fine particles, and as a result, the primary particle range of the metal fine particles was controlled to 1 to 30 nm and the secondary particle diameter was controlled to 5 to 100 nm. Is oxidized, the surface charge amount when the concentration of fine particles of the metal fine particle dispersion is 0.5% by weight is in the range of 0.5 to 45 μeq / g, and the electric conductivity is in the range of 1 to 15 μS / cm. Occasionally, the stability of the metal fine particle dispersion and the coating liquid for forming the transparent conductive film is increased, and it is found that oxidation is suppressed even in a high temperature region, and that a transparent conductive film having excellent durability can be obtained. The present invention has been completed.

本発明に係る金属微粒子分散液は、金属微粒子と、分散媒とを含む金属微粒子分散液において、
前記金属微粒子は、Ａｇ、Ｐｄ、Ｃｕ、Ｒｕ、Ｒｈ、ＰｔおよびＡｕからなる金属群より選ばれる少なくとも１種以上の金属を含み、その一次粒子径が１〜３０ｎｍの範囲であり、二次粒子径が５〜１００ｎｍの範囲であり、当該金属微粒子の０．１〜３０重量％が酸化されていることと、
金属微粒子濃度が０．５重量％のときの表面電荷量が０．５〜４５μｅｑ／ｇの範囲であり、電気伝導度が１〜１５μＳ／ｃｍの範囲であることと、を備えたことを特徴としている。
前記金属微粒子が、前記金属群に含まれる単独の金属、またはＰｄ−Ａｇ、Ｐｄ−Ｐｔ、Ｐｄ−Ｃｕ、Ａｇ−Ｃｕ、Ｐｄ−Ａｕ、Ｐｔ−Ｒｈ、Ｐｄ−Ｐｔ−Ｒｈ、Ｐｄ−Ｒｈであることが好ましい。 The metal fine particle dispersion according to the present invention is a metal fine particle dispersion containing metal fine particles and a dispersion medium.
The metal fine particles include at least one metal selected from the metal group consisting of Ag, Pd, Cu, Ru, Rh, Pt and Au, the primary particle diameter is in the range of 1 to 30 nm, and the secondary particles The diameter is in the range of 5 to 100 nm, 0.1 to 30% by weight of the metal fine particles are oxidized,
The surface charge amount when the metal fine particle concentration is 0.5% by weight is in the range of 0.5 to 45 μeq / g, and the electric conductivity is in the range of 1 to 15 μS / cm. It is said.
The metal fine particle is a single metal included in the metal group, or Pd-Ag, Pd-Pt, Pd-Cu, Ag-Cu, Pd-Au, Pt-Rh, Pd-Pt-Rh, Pd-Rh. Preferably there is.

前記金属微粒子分散液は、７０℃の保管条件下で、前記金属微粒子分散液を調製してから３０日間経過するまでの二次粒子径の変化率が１．５倍以内であることが好適である。また、前記金属微粒子濃度が０．５重量％のときのｐＨが２〜１１の範囲であることが好ましい。そして前記金属微粒子はＣｌ成分の含有量が金属微粒子に対して０．５〜３重量％の範囲であることが好ましい。また、前記分散媒は、水、クエン酸水溶液、モノエチレングリコールからなる分散媒群から選ばれる場合が挙げられる。   The metal fine particle dispersion preferably has a change rate of secondary particle diameter within 1.5 times from the preparation of the metal fine particle dispersion to 30 days after storage at 70 ° C. is there. Moreover, it is preferable that pH is the range of 2-11 when the said metal microparticle density | concentration is 0.5 weight%. The metal fine particles preferably have a Cl component content in the range of 0.5 to 3% by weight with respect to the metal fine particles. Moreover, the case where the said dispersion medium is chosen from the dispersion medium group which consists of water, a citric acid aqueous solution, and monoethylene glycol is mentioned.

本発明に係る透明導電性被膜形成用塗布液は、金属微粒子分散液と極性溶媒とを含むことを特徴としている。この透明導電性被膜形成用塗布液にはバインダー成分を含んでもよい。   The coating liquid for forming a transparent conductive film according to the present invention is characterized by containing a metal fine particle dispersion and a polar solvent. This transparent conductive film-forming coating solution may contain a binder component.

本発明に係る透明導電性被膜付基材は、基材と、基材上の透明導電性微粒子層のみ若しくは、該透明導電性微粒子層上に設けられ、該透明導電性微粒子層よりも屈折率が低い透明被膜とからなる透明導電性被膜付基材において、前記透明導電性微粒子層が前記透明導電性被膜形成用塗布液から形成されたものであることを特徴としている。   The substrate with a transparent conductive film according to the present invention is provided only on the transparent conductive fine particle layer on the substrate or on the transparent conductive fine particle layer, and has a refractive index higher than that of the transparent conductive fine particle layer. A transparent conductive film-coated substrate comprising a low transparent film, wherein the transparent conductive fine particle layer is formed from the transparent conductive film-forming coating solution.

本発明によれば、０．１〜３０重量％と酸化物の含有量が少ない金属微粒子を用い、表面電荷量及び電気伝導度が予め設定された範囲に調整された金属微粒子分散液を用いることで、二次粒子径が変化しにくい、安定した金属微粒子を提供することができる。この結果、導電性が低く、造膜性の高い透明導電性被膜形成用塗布液及びこの塗布液を用いた透明導電性被膜付基材が得られる。   According to the present invention, the metal fine particle dispersion liquid in which the surface charge amount and the electric conductivity are adjusted to a preset range is used using metal fine particles having a small oxide content of 0.1 to 30% by weight. Thus, it is possible to provide stable metal fine particles in which the secondary particle diameter hardly changes. As a result, a coating liquid for forming a transparent conductive film having a low conductivity and a high film forming property and a substrate with a transparent conductive film using this coating liquid are obtained.

以下、本発明について具体的に説明する。
金属微粒子
まず、本発明の金属微粒子分散液に含まれる金属微粒子について説明する。本発明に係る金属微粒子は、Ａｇ、Ｐｄ、Ｃｕ、Ｒｕ、Ｒｈ、白金および金からなる群より選ばれる少なくとも１種以上の金属を含む（複合）金属微粒子からなっている。 Hereinafter, the present invention will be specifically described.
Metal fine particles
First, the metal fine particles contained in the metal fine particle dispersion of the present invention will be described. The metal fine particles according to the present invention are composed of (composite) metal fine particles containing at least one metal selected from the group consisting of Ag, Pd, Cu, Ru, Rh, platinum and gold.

このような金属微粒子の金属は、単体金属のほか、複合金属の場合には固溶状態にある合金であっても、固溶状態に無い共晶体であってもよく、合金と共晶体が共存していてもよい。なかでも、固溶状態にある合金の金属微粒子は導電性被膜に用いた場合、酸化やイオン化による金属微粒子の粒子成長が抑制され、塗膜の導電性や光透過率の低下が小さく、信頼性の高い透明導電性被膜付基材が得られる。   The metal of such fine metal particles may be a single metal, an alloy in the form of a solid solution in the case of a composite metal, or a eutectic that is not in a solid solution, and the alloy and the eutectic coexist. You may do it. In particular, when metal fine particles of an alloy in a solid solution state are used in a conductive film, the growth of metal fine particles due to oxidation or ionization is suppressed, and the decrease in conductivity and light transmittance of the coating film is small. A substrate with a transparent conductive film having a high thickness can be obtained.

本発明に係る金属微粒子の好ましい金属の組合せとしては、Ａｇ、Ｐｄ、Ｃｕ、Ｒｕ、Ｒｈ、Ｐｔ、Ａｕのみ、Ａｇ−Ｐｄ、Ａｇ−Ｃｕ、Ａｇ−Ｐｕ、Ａｇ−Ｒｈ、Ａｇ−Ｐｔ、Ａｇ−Ａｕ、Ｐｄ−Ｃｕ、Ｐｄ−Ｒｕ、Ｐｄ−Ｒｈ、Ｐｄ−Ｐｔ、Ｐｄ−Ａｕ、Ｃｕ−Ｒｕ、Ｃｕ−Ｒｈ、Ｃｕ−Ｐｔ、Ｃｕ−Ａｕ、Ｒｕ−Ｒｈ、Ｒｕ−Ｐｔ、Ｒｕ−Ａｕ、Ｒｈ−Ｐｔ、Ｒｈ−Ａｕ、Ｐｔ−Ａｕ、Ａｇ−Ｐｄ−Ｃｕ、Ａｇ−Ｐｄ−Ｐｔ、Ａｇ−Ｐｄ−Ａｕ、Ｐｄ−Ｃｕ−Ｒｕ、Ｐｄ−Ｃｕ−Ｒｈ、Ｐｄ−Ｃｕ−Ｐｔ、Ｐｄ−Ｃｕ−Ａｕ、Ｐｄ−Ｒｕ−Ｒｈ、Ｐｄ−Ｒｕ−Ｐｔ、Ｐｄ−Ｒｕ−Ａｕ、Ｐｄ−Ｒｈ−Ｐｔ、Ｐｄ−Ｒｈ−Ａｕなどが挙げられる。   Preferred metal combinations of the fine metal particles according to the present invention include Ag, Pd, Cu, Ru, Rh, Pt, Au only, Ag-Pd, Ag-Cu, Ag-Pu, Ag-Rh, Ag-Pt, Ag. -Au, Pd-Cu, Pd-Ru, Pd-Rh, Pd-Pt, Pd-Au, Cu-Ru, Cu-Rh, Cu-Pt, Cu-Au, Ru-Rh, Ru-Pt, Ru-Au Rh—Pt, Rh—Au, Pt—Au, Ag—Pd—Cu, Ag—Pd—Pt, Ag—Pd—Au, Pd—Cu—Ru, Pd—Cu—Rh, Pd—Cu—Pt, Pd -Cu-Au, Pd-Ru-Rh, Pd-Ru-Pt, Pd-Ru-Au, Pd-Rh-Pt, Pd-Rh-Au, and the like.

本発明に係る金属微粒子の一次粒子径は１〜３０ｎｍ、好ましくは２〜２０ｎｍの範囲にある。一次粒子径が１〜３０ｎｍの範囲にあると、透明性の高い導電性被膜を得ることができる。金属微粒子の一次粒径が３０ｎｍを越えると、光の散乱が大きくなり、粒子層の光透過率が低下するとともにへーズが大きくなる。また、金属微粒子の平均粒径が１ｎｍ未満の場合は得ることが困難である。   The primary particle diameter of the metal fine particles according to the present invention is in the range of 1 to 30 nm, preferably 2 to 20 nm. When the primary particle diameter is in the range of 1 to 30 nm, a highly transparent conductive film can be obtained. When the primary particle diameter of the metal fine particles exceeds 30 nm, light scattering increases, and the light transmittance of the particle layer decreases and haze increases. In addition, it is difficult to obtain when the average particle size of the metal fine particles is less than 1 nm.

本発明に係る金属微粒子の二次粒子径は５〜１００ｎｍ、好ましくは５〜８０ｎｍの範囲にある。二次粒子径が５〜１００ｎｍの範囲にあると、被膜粒子のパッキングが良く、導電性が向上し、透明性の高い導電性被膜を得ることができる。金属微粒子の二次粒径が１００ｎｍを越えると、被膜粒子のパッキングが悪く、導電性が悪化する場合がある。また光の散乱が大きく透明性の低下、ヘーズの上昇を引き起こす場合がある。また、金属微粒子の二次粒径が１ｎｍ未満の場合は得ることが困難である。   The secondary particle diameter of the metal fine particles according to the present invention is in the range of 5 to 100 nm, preferably 5 to 80 nm. When the secondary particle diameter is in the range of 5 to 100 nm, the packing of the coated particles is good, the conductivity is improved, and a highly transparent conductive film can be obtained. If the secondary particle size of the metal fine particles exceeds 100 nm, the coating particles may be poorly packed and the conductivity may be deteriorated. In addition, light scattering is large, which may cause a decrease in transparency and an increase in haze. Moreover, it is difficult to obtain when the secondary particle size of the metal fine particles is less than 1 nm.

また前記二次粒子径は経時的に安定していることが好ましく、７０℃保管の条件での金属微粒子分散液を調製してから３０日後の二次粒子径の変化率が１．５倍以内であるとよい。上述のように金属微粒子の二次粒子径は、当該金属微粒子を利用して形成された透明導電性被膜の導電性に影響を及ぼすところ、二次粒子径の経時変化が少ない金属微粒子分散液は導電性の低い透明導電性被膜を形成可能な期間が長く、透明導電性被膜形成用塗布液の原料としてのポットライフが長いといえる。   The secondary particle size is preferably stable over time, and the change rate of the secondary particle size after 30 days from the preparation of the metal fine particle dispersion under the condition of storage at 70 ° C. is within 1.5 times. It is good to be. As described above, the secondary particle size of the metal fine particles affects the conductivity of the transparent conductive film formed by using the metal fine particles. It can be said that the period during which a transparent conductive film with low conductivity can be formed is long, and the pot life as a raw material for the coating liquid for forming a transparent conductive film is long.

このようなポットライフの長い金属微粒子分散液として、金属微粒子分散液の微粒子濃度が０．５重量％のときの表面電荷量が０．５〜４５μｅｑ／ｇ、さらには１〜４０μｅｑ／ｇであることが好ましい。表面電荷量は金属微粒子表面の電荷と、金属微粒子分散液中に含まれる不純物の電荷の和として捉えることができる。したがってこのような範囲の金属微粒子分散液は、不純物の含有量が少ないことから、ポットライフが長いとともに導電性の高い導電性被膜を得ることができる。表面電荷量が４５μｅｑ／ｇ超えると電荷が高く、透明導電膜形成塗布液にした際に液中で金属微粒子が凝集する場合がある。表面電荷量が１μｅｑ／ｇ未満の金属微粒子分散液は得ることが困難である。なお、表面電荷量は、表面電荷量測定装置（Mutec社製:PCD０３PH）などで測定される。このような表面電荷量は、微粒子濃度が０．５重量％の分散液で測定される。   As such a metal fine particle dispersion having a long pot life, the surface charge amount when the fine particle concentration of the metal fine particle dispersion is 0.5% by weight is 0.5 to 45 μeq / g, and further 1 to 40 μeq / g. It is preferable. The surface charge amount can be understood as the sum of the charge on the surface of the metal fine particles and the charge of the impurities contained in the metal fine particle dispersion. Therefore, since the metal fine particle dispersion in such a range has a low impurity content, a conductive film having a long pot life and high conductivity can be obtained. When the surface charge amount exceeds 45 μeq / g, the charge is high, and when the transparent conductive film forming coating solution is used, the metal fine particles may aggregate in the solution. It is difficult to obtain a metal fine particle dispersion having a surface charge amount of less than 1 μeq / g. The surface charge amount is measured with a surface charge amount measuring device (Mutec: PCD03PH). Such a surface charge amount is measured with a dispersion having a fine particle concentration of 0.5% by weight.

またポットライフの長い金属微粒子分散液は、当該分散液の電気伝導度の観点からも規定できる。即ち、金属微粒子分散液の微粒子濃度が０．５重量％のときの電気伝導度が１〜１５μＳ／ｃｍ、さらには２〜１２μＳ／ｃｍであることが好ましい。このような範囲の金属微粒子分散液についても、不純物の含有量が少ないことからポットライフが長いとともに導電性の高い導電性被膜を得ることができる。電気伝導度が１５μＳ／ｃｍを超えると分散液の安定性が低く（二次粒子が成長しやすく）、透明導電膜形成塗布液にした際に液中で金属微粒子が凝集する場合がある。電気伝導度が１μＳ／ｃｍ未満のものは得ることが困難である。   Moreover, the metal fine particle dispersion having a long pot life can be defined from the viewpoint of the electrical conductivity of the dispersion. That is, when the fine particle concentration of the metal fine particle dispersion is 0.5% by weight, the electric conductivity is preferably 1 to 15 μS / cm, more preferably 2 to 12 μS / cm. Also for the metal fine particle dispersion in such a range, since the content of impurities is small, a conductive film having a long pot life and high conductivity can be obtained. When the electric conductivity exceeds 15 μS / cm, the dispersion is low in stability (secondary particles are likely to grow), and metal fine particles may aggregate in the liquid when formed into a transparent conductive film forming coating solution. It is difficult to obtain a material having an electric conductivity of less than 1 μS / cm.

さらに導電性の高い透明導電性被膜を形成することが可能な金属微粒子分散液として、当該分散液に含まれる金属微粒子は０．１〜３０重量％酸化されていることが好ましい。さらに好ましい酸化の範囲は０．５〜２５重量％である。酸化の状態は、部分酸化、単体と酸化物の混合のいずれであってもよい。後述の実施例に示すように酸化物の含有量がこの範囲にある金属微粒子は、基材への塗布後の焼成の際に酸化されにくく、透明導電性被膜の導電性が悪化しにくいことを把握している。ここで金属微粒子に含まれる酸化物が０．１重量％未満のものは、得ることが困難である。また３０重量％を超えて酸化されたものは、透明導電性被膜の形成後に導電性が悪化したり、酸化が促進される場合があり、透明導電膜の耐久性が悪化する場合がある。   Furthermore, as the metal fine particle dispersion capable of forming a transparent conductive film having high conductivity, the metal fine particles contained in the dispersion are preferably oxidized by 0.1 to 30% by weight. A more preferred oxidation range is 0.5 to 25% by weight. The oxidation state may be any of partial oxidation and a mixture of simple substance and oxide. As shown in the examples described later, the metal fine particles having an oxide content within this range are less likely to be oxidized during firing after application to the substrate, and the conductivity of the transparent conductive film is less likely to deteriorate. I know. Here, it is difficult to obtain an oxide containing less than 0.1% by weight of oxide contained in the metal fine particles. Moreover, the thing oxidized more than 30 weight% may deteriorate electroconductivity after formation of a transparent conductive film, oxidation may be accelerated | stimulated, and durability of a transparent conductive film may deteriorate.

これらに加え、ポットライフの長い金属微粒子分散液の指標として、当該分散液のｐＨに着目してもよい。即ち、金属微粒子分散液の微粒子濃度が０．５重量％のときのｐＨが２〜１１、さらには２．５〜１０であることが好ましい。金属微粒子のｐＨをこのような範囲に調整することにより、ポットライフが長いとともに導電性の高い導電性被膜を得ることができる。ｐＨが１１を超えると金属微粒子の酸化が促進したり、分散液の安定性が低く、透明導電膜形成塗布液にした際に液中で金属微粒子が凝集する場合がある。ｐＨが２未満である場合も金属微粒子がイオン化し、導電膜形成後空気中の酸素の影響で酸化が促進される場合がある。また分散液の安定性も低く、透明導電膜形成塗布液にした際に液中で金属微粒子が凝集する場合がある。   In addition to these, as an index of the metal fine particle dispersion having a long pot life, attention may be paid to the pH of the dispersion. That is, the pH when the fine particle concentration of the metal fine particle dispersion is 0.5% by weight is preferably 2 to 11, more preferably 2.5 to 10. By adjusting the pH of the metal fine particles to such a range, a conductive film having a long pot life and high conductivity can be obtained. If the pH exceeds 11, the oxidation of the metal fine particles is promoted, or the stability of the dispersion liquid is low, and the metal fine particles may aggregate in the liquid when it is used as a coating solution for forming a transparent conductive film. Even when the pH is less than 2, the metal fine particles may be ionized, and oxidation may be promoted by the influence of oxygen in the air after the conductive film is formed. In addition, the dispersion is low in stability, and when the transparent conductive film forming coating solution is used, the metal fine particles may aggregate in the solution.

以上のような本発明に係る金属微粒子は、０．１〜３０重量％が酸化され、ｐＨ、電気伝導度、表面電荷量が上記記載の範囲にあるため、金属微粒子が酸化を受けにくくなるとともに、高い導電性を保持し、合金的特性が強く、導電性被膜に用いた場合に金属の酸化やイオン化を抑制することができ、粒子成長が抑制されるので導電性や光透過率の低下を抑制することができる。さらに、このような金属微粒子分散液は二次粒子径が変化しにくく安定であるため、極性溶媒と混合した後もポットライフの長い透明導電性被膜形成用塗布液を得ることができる。   In the metal fine particles according to the present invention as described above, 0.1 to 30% by weight are oxidized, and the pH, electrical conductivity, and surface charge amount are in the ranges described above. High electrical conductivity, strong alloying properties, and when used in conductive coatings, can suppress metal oxidation and ionization and suppress particle growth, reducing conductivity and light transmittance. Can be suppressed. In addition, since such a metal fine particle dispersion is stable in which the secondary particle diameter is not easily changed, a coating liquid for forming a transparent conductive film having a long pot life can be obtained even after mixing with a polar solvent.

本発明に係る金属微粒子の分散液は、得られる金属微粒子の０．１〜３０％が酸化され、ｐＨ、電気伝導度、表面電荷量が上記記載の範囲となっている。このような金属微粒子分散液は、（Ａ）水または有機溶媒の少なくとも一方からなる溶媒中、還元剤の存在下で、Ａｇ、Ｐｄ、Ｃｕ、Ｒｕ、Ｒｈ、ＰｔおよびＡｕからなる金属群より選ばれる少なくとも１種以上の金属の塩を還元して、金属微粒子を生成する工程と、
（Ｂ）前記金属微粒子を分散媒中に分散させてなる金属微粒子分散液に含まれる不純物を低減する工程と、
（Ｃ）前記金属微粒子を酸と接触させる工程と、
（Ｄ）前記金属微粒子をアルカリと接触させる工程と、を実行することにより製造することができる。
前記（Ｃ）の工程にて使用する酸が、塩酸、硫酸、硝酸、クエン酸、酢酸、蟻酸より選ばれる少なくとも１種以上であることを特徴とする。さらに上記（Ｄ）の工程にて使用するアルカリが、アンモニア、三級アミン、四級アミンより選ばれる少なくとも１種以上であることを特徴とする。 In the dispersion of fine metal particles according to the present invention, 0.1 to 30% of the obtained fine metal particles are oxidized, and the pH, electrical conductivity, and surface charge amount are in the above-described ranges. Such a metal fine particle dispersion is selected from the group of metals consisting of Ag, Pd, Cu, Ru, Rh, Pt and Au in the presence of a reducing agent in a solvent consisting of (A) water or an organic solvent. Reducing at least one metal salt to produce metal fine particles;
(B) a step of reducing impurities contained in a metal fine particle dispersion obtained by dispersing the metal fine particles in a dispersion medium;
(C) contacting the metal fine particles with an acid;
(D) It can manufacture by performing the process which makes the said metal microparticles contact with an alkali.
The acid used in the step (C) is at least one selected from hydrochloric acid, sulfuric acid, nitric acid, citric acid, acetic acid, and formic acid. Furthermore, the alkali used in the step (D) is at least one selected from ammonia, tertiary amines and quaternary amines.

上述の金属微粒子はたとえば以下の製造方法で製造することができる。
金属微粒子の製造方法
（Ａ）１種以上の金属の塩を還元する工程
まず、１種以上の金属の塩を還元する工程に関して説明する。
水および／または有機溶媒からなる溶媒中、還元剤の存在下で、１種以上の金属の塩を還元する。具体的には、下記の方法が挙げられる。水および／または有機溶媒からなる溶媒中で、１種類、または複数種類の金属の塩を同時に、還元剤の存在下で還元する方法。還元剤は従来公知還元剤を使用してよい。溶媒の具体例としては、水、クエン酸水溶液、モノエチレングリコールなどを挙げることができる。生成した金属粒子をこの溶媒から分離せずに金属微粒子分散液を調製するときには、この溶媒が金属微粒子分散液の分散媒となる。また生成した金属粒子を溶媒から一旦分離して、再度液体に分散させる場合には、後者の液体が分散媒となる。 The above-mentioned metal fine particles can be produced, for example, by the following production method.
Method for producing metal fine particles
(A) A step of reducing one or more metal salts
First, the step of reducing one or more metal salts will be described.
One or more metal salts are reduced in a solvent comprising water and / or an organic solvent in the presence of a reducing agent. Specifically, the following method is mentioned. A method of reducing one or more kinds of metal salts simultaneously in the presence of a reducing agent in a solvent comprising water and / or an organic solvent. A conventionally known reducing agent may be used as the reducing agent. Specific examples of the solvent include water, an aqueous citric acid solution, and monoethylene glycol. When preparing the metal fine particle dispersion without separating the generated metal particles from the solvent, this solvent serves as a dispersion medium for the metal fine particle dispersion. Further, when the generated metal particles are once separated from the solvent and dispersed again in the liquid, the latter liquid serves as a dispersion medium.

金属塩としては、硫酸塩、酢酸塩および有機酸塩等の塩およびこれらの混合物塩等が挙げられる。具体的には、塩化金酸、塩化白金酸、硝酸銀、塩化パラジウム、硝酸パラジウム、酢酸パラジウム、塩化ルテニウム、硝酸ロジウム、塩化ロジウム、硝酸銅、塩化銅、クエン酸銅、硝酸銀、等およびこれらの混合物塩等が挙げられる。   Examples of the metal salt include salts such as sulfates, acetates and organic acid salts, and mixed salts thereof. Specifically, chloroauric acid, chloroplatinic acid, silver nitrate, palladium chloride, palladium nitrate, palladium acetate, ruthenium chloride, rhodium nitrate, rhodium chloride, copper nitrate, copper chloride, copper citrate, silver nitrate, etc. and mixtures thereof Examples include salts.

水および／または有機溶媒からなる溶媒中の金属の塩の濃度は、金属に換算した合計の濃度が０.０１〜３.０重量％、さらには０.０２〜２.０重量％の範囲にあることが好ましい。有機溶媒としては、メタノール、エタノール、２−プロパノール、４−ヒドロキシ−４−メチル−２−ペンタノン、テトラヒドロフルフリルアルコールなどのアルコール類、エチレングリコール、プロピレングリコール、へキシレングルコールなどのグリコール類、プロピレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテルなどのエーテル類が使用される。
本発明では、溶媒は単独溶媒であってもよいし、２種以上の混合溶媒であってもよく、さらには有機溶媒と水との混合溶媒であってもよい。 The concentration of the metal salt in the solvent consisting of water and / or an organic solvent is such that the total concentration in terms of metal is in the range of 0.01 to 3.0% by weight, and further 0.02 to 2.0% by weight. Preferably there is. Examples of the organic solvent include alcohols such as methanol, ethanol, 2-propanol, 4-hydroxy-4-methyl-2-pentanone and tetrahydrofurfuryl alcohol, glycols such as ethylene glycol, propylene glycol and hexylene glycol, propylene Ethers such as glycol monomethyl ether and diethylene glycol monoethyl ether are used.
In the present invention, the solvent may be a single solvent, a mixed solvent of two or more kinds, or a mixed solvent of an organic solvent and water.

金属の塩の濃度が、生成する金属に換算した合計の濃度で０.０１重量％未満の場合は、金属微粒子の生成速度が遅くなったり、得られる金属微粒子の粒子径が不均一になる傾向があり、また金属微粒子の収率が著しく低下することがある。金属の塩の濃度が、金属に換算した合計の濃度で３.０重量％を越えると、金属イオンの還元析出が早すぎて得られる金属微粒子の粒子径が不均一になったり凝集する傾向にある。   When the concentration of the metal salt is less than 0.01% by weight in terms of the total concentration in terms of the metal to be produced, the production rate of the metal fine particles tends to be slow or the particle size of the resulting metal fine particles tends to be non-uniform. In addition, the yield of metal fine particles may be significantly reduced. When the concentration of the metal salt exceeds 3.0% by weight in terms of the total metal, the reduction of metal ions is prematurely reduced, and the resulting metal particles tend to be non-uniform or aggregate. is there.

つぎに、還元剤としては、硫酸第１鉄、硫酸アンモニウム第１鉄、蓚酸第１鉄、クエン酸３ナトリウム、酒石酸、Ｌ(+)−アスコルビン酸、水素化ホウ素ナトリウム、次亜リン酸ナトリウム、メタノール、エタノール、エチレングリコールなどが挙げられる。
還元剤として水素化ホウ素ナトリウムや次亜リン酸ナトリウムを使用すると、金属微粒子中にＢ、Ｐが含まれてしまうが、硫酸第１鉄、硫酸アンモニウム第１鉄のような鉄塩を還元剤として用いると、Ｂ、Ｐを含まない導電性の高い金属微粒子を得ることができる。 Next, as a reducing agent, ferrous sulfate, ferrous ammonium sulfate, ferrous oxalate, trisodium citrate, tartaric acid, L (+)-ascorbic acid, sodium borohydride, sodium hypophosphite, methanol , Ethanol, ethylene glycol and the like.
When sodium borohydride or sodium hypophosphite is used as the reducing agent, B and P are contained in the metal fine particles, but iron salts such as ferrous sulfate and ferrous ammonium sulfate are used as the reducing agent. Then, it is possible to obtain highly conductive metal fine particles that do not contain B and P.

このとき用いる還元剤の量は、金属の塩との合計１モル当たりに０.１〜５.０モル、さらには１.０〜３.０モルの範囲にあることが好ましい。このような範囲にあれば金属微粒子の収率が高く、導電性が高い金属微粒子を得ることができる。還元剤の量が、合計の金属の塩１モル当たりに０.１モル未満の場合は、還元能力が不充分なために金属微粒子の収率が低下し、必要量の金属微粒子中が得られないことがある。還元剤の量が、金属塩の合計の１モル当たり５.０モルを越えてもさらに収率が向上することもなく、還元剤によってはＢやＰを多く含む金属微粒子が得られ、導電性が不充分となることがある。   The amount of the reducing agent used at this time is preferably in the range of 0.1 to 5.0 mol, more preferably 1.0 to 3.0 mol, per 1 mol in total with the metal salt. Within such a range, it is possible to obtain metal fine particles having a high yield of metal fine particles and high conductivity. When the amount of the reducing agent is less than 0.1 mol per 1 mol of the total metal salt, the yield of metal fine particles is reduced due to insufficient reduction ability, and the required amount of metal fine particles is obtained. There may not be. Even if the amount of the reducing agent exceeds 5.0 mol per 1 mol of the total amount of the metal salt, the yield is not further improved, and depending on the reducing agent, metal fine particles containing a large amount of B and P can be obtained. May be insufficient.

このような還元剤を用いた還元条件としては、金属塩を還元しうる条件であれば特に制限されるものではなく、前記した濃度に調製した金属塩に、還元剤を添加して、必要に応じて、加熱したり、撹拌すればよい。さらに、本発明では、必要に応じて有機安定化剤を用いることができる。有機安定化剤としては、たとえばゼラチン、ポリビニルアルコール、ポリビニルピロリドン、ポリアクリル酸、ヒドロキシプロピルセルロース、およびシュウ酸、マロン酸、コハク酸、グルタール酸、アジピン酸、セバシン酸、マレイン酸、フマル酸、フタル酸、クエン酸などの多価カルボン酸およびその塩、複素環化合物あるいはこれらの混合物などが挙げられる。安定化剤は金属塩を還元して得られる金属微粒子（コロイド）を安定化させる役割を果たす。   The reducing conditions using such a reducing agent are not particularly limited as long as the metal salt can be reduced, and it is necessary to add a reducing agent to the metal salt prepared at the above-described concentration. Accordingly, heating or stirring may be performed. Furthermore, in this invention, an organic stabilizer can be used as needed. Organic stabilizers include, for example, gelatin, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, hydroxypropyl cellulose, and oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalate Examples thereof include polyvalent carboxylic acids such as acids and citric acid and salts thereof, heterocyclic compounds, and mixtures thereof. The stabilizer plays a role of stabilizing metal fine particles (colloid) obtained by reducing the metal salt.

このような有機安定化剤の使用量は、生成する金属微粒子１モルに対し有機系安定化剤を１〜１０モル、好ましくは２〜８モル含まれていればよい。有機系安定化剤の量が１モル／モル金属未満の場合、得られる金属微粒子の分散性が不充分であり金属微粒子が凝集することがあり、１０モル／モル金属を越えると残留する有機安定化剤により導電性が阻害されることがある。
また、本発明の方法では、上記還元して得られた金属微粒子の分散液を必要に応じて圧力容器中、約１００℃以上の温度で加熱処理してもよい。 The organic stabilizer may be used in an amount of 1 to 10 mol, preferably 2 to 8 mol, based on 1 mol of the generated metal fine particles. When the amount of the organic stabilizer is less than 1 mol / mol metal, the dispersibility of the obtained metal fine particles is insufficient, and the metal fine particles may agglomerate. The conductivity may be inhibited by the agent.
In the method of the present invention, the metal fine particle dispersion obtained by the reduction may be heat-treated in a pressure vessel at a temperature of about 100 ° C. or higher as necessary.

上述の金属の塩の還元工程にて生成する金属微粒子の一次粒子径は、溶媒中の金属塩の濃度や安定化剤の添加量を変化させることにより調整することができる。金属塩の濃度を高くすると、金属微粒子の一次粒子径は大きくなり、安定化剤の添加量を増やすと金属微粒子の一次粒子径は小さくなる。これら金属塩の濃度や安定化剤の添加量を調整することなどにより、分散液中の金属微粒子の一次粒子径を１〜３０ｎｍの範囲に調整することができる。   The primary particle diameter of the metal fine particles generated in the above-described metal salt reduction step can be adjusted by changing the concentration of the metal salt in the solvent and the amount of the stabilizer added. When the concentration of the metal salt is increased, the primary particle diameter of the metal fine particles is increased, and when the amount of the stabilizer is increased, the primary particle diameter of the metal fine particles is decreased. By adjusting the concentration of these metal salts and the amount of stabilizer added, the primary particle diameter of the metal fine particles in the dispersion can be adjusted to a range of 1 to 30 nm.

（Ｂ）金属の塩を還元して得られた金属微粒子を含む分散液から不純物を低減する工程
次に（Ａ）で得られた金属微粒子を含む分散液から不純分を低減する工程に関して説明する。この工程は従来公知の方法を用いることができる。例えば、水やアルコールを用いてフィルターで濾過してイオン成分を低減する方法。限外膜を用いて低減する方法、デカンテーションで不純分を低減する方法、イオン交換膜やイオン交換樹脂でイオンを低減する方法、活性炭などで有機物を低減する方法などが挙げられる。低減する不純物としては、既述の二次粒子の粒径範囲よりも大きな粗大粒子や溶媒に含まれる高分子成分、イオンなどが挙げられる。これらの不純物は金属粒子分散液の表面電荷量や電気伝導度を上昇させる要因となり、分散液に含まれるイオンをイオン交換樹脂などで取り除く場合は勿論、限外濾過膜で帯電性の粗大粒子や高分子成分を取り除くことによっても金属粒子分散液の表面電荷量や電気伝導度を調整することができる。 (B) A step of reducing impurities from a dispersion containing fine metal particles obtained by reducing a metal salt.
Next, the step of reducing impurities from the dispersion containing metal fine particles obtained in (A) will be described. For this step, a conventionally known method can be used. For example, a method of reducing ionic components by filtering with water or alcohol. Examples thereof include a method of reducing using an ultra-membrane, a method of reducing impurities by decantation, a method of reducing ions with an ion-exchange membrane or an ion-exchange resin, and a method of reducing organic matter with activated carbon. Examples of the impurities to be reduced include coarse particles larger than the above-described secondary particle size range, polymer components contained in the solvent, ions, and the like. These impurities increase the surface charge amount and electrical conductivity of the metal particle dispersion, and of course, when removing ions contained in the dispersion with an ion exchange resin or the like, the ultrafiltration membrane can also charge coarse particles and The surface charge amount and electric conductivity of the metal particle dispersion can also be adjusted by removing the polymer component.

不純物の低減の完了の目安は電気伝導度を用いることができ、０．５重量％の金属微粒子分散液の状態で、電気伝導度が１μＳ／ｃｍ〜１ｍＳ／ｃｍの範囲であることが好ましい。１ｍＳ／ｃｍ以上の場合は、不純物低減が不充分であるため、透明導電性被膜塗布液を調製した際に凝集を引き起こす場合があったり、ポットライフも短い場合がある。またこの工程で二次粒子径が大きくなった場合は、必要に応じて遠心分離機などを使用し粗大粒子低減を行うこともできる。   As a measure for completing the reduction of impurities, the electric conductivity can be used, and the electric conductivity is preferably in the range of 1 μS / cm to 1 mS / cm in the state of 0.5 wt% metal fine particle dispersion. In the case of 1 mS / cm or more, since the impurity reduction is insufficient, aggregation may occur when the transparent conductive film coating solution is prepared, and the pot life may be short. In addition, when the secondary particle size is increased in this step, coarse particles can be reduced by using a centrifuge if necessary.

（Ｃ）酸で処理する工程、
次に（Ｂ）で得られた金属微粒子を酸で処理する工程に関して説明する。この工程は、金属微粒子を酸で処理することで、不純分の低減や酸化状態の調整を行う。使用する酸は、従来公知の酸を使用することが可能である。具体的には、塩酸、硫酸、硝酸、クエン酸、酢酸、蟻酸より選ばれる少なくとも１種以上が挙げられる。使用する酸は１種でもよく、２種類以上でもよく、不純物の低減や酸化状態の調整に好適な酸を金属微粒子によって適宜選択することができる。 (C) a step of treating with an acid,
Next, the step of treating the metal fine particles obtained in (B) with an acid will be described. In this step, the metal fine particles are treated with an acid to reduce impurities and adjust the oxidation state. As the acid to be used, a conventionally known acid can be used. Specific examples include at least one selected from hydrochloric acid, sulfuric acid, nitric acid, citric acid, acetic acid, and formic acid. The acid to be used may be one kind or two or more kinds, and an acid suitable for reducing impurities and adjusting the oxidation state can be appropriately selected by metal fine particles.

酸での処理は金属に対して０．０１〜１０重量％の範囲の量の酸で処理することが好ましく、さらには０．０２〜５重量％の範囲であることがより好ましい。酸の量が０．０１重量％未満の場合は、不純分の低減が不十分な場合がある。酸の量が５重量％を超える場合は、粒子が凝集する場合がある。酸による処理は、金属微粒子と適量の酸を混合し、１０℃〜２００℃の温度で１〜６０分攪拌すればよい。温度が１０℃未満であると不純物の低減効果が得られにくく、２００℃を超えると金属微粒子が凝集する場合がある。   The treatment with an acid is preferably carried out with an acid in an amount in the range of 0.01 to 10% by weight relative to the metal, and more preferably in the range of 0.02 to 5% by weight. If the amount of acid is less than 0.01% by weight, the impurity content may not be sufficiently reduced. If the amount of acid exceeds 5% by weight, the particles may aggregate. The treatment with acid may be performed by mixing metal fine particles and an appropriate amount of acid and stirring at a temperature of 10 ° C. to 200 ° C. for 1 to 60 minutes. If the temperature is less than 10 ° C, the effect of reducing impurities is difficult to obtain, and if it exceeds 200 ° C, the metal fine particles may aggregate.

攪拌後は（Ｂ）の工程と同様に従来公知の方法で不純分の低減を行うことができる。具体的には限外膜を用いて不純物を低減する方法、デカンテーションで沈殿しない不純分を低減する方法、イオン交換膜やイオン交換樹脂でイオンを低減する方法などが挙げられる。処理の完了の目安は電気伝導度を用いることができ、０．５重量％の金属微粒子分散液の状態で電気伝導度が１μＳ／ｃｍ〜１００μＳ/ｃｍの範囲であることが好ましい。   After the stirring, the impurity content can be reduced by a conventionally known method as in the step (B). Specific examples include a method of reducing impurities using an ultra-membrane, a method of reducing impurities not precipitated by decantation, and a method of reducing ions with an ion-exchange membrane or ion-exchange resin. As an indication of the completion of the treatment, the electric conductivity can be used, and the electric conductivity is preferably in the range of 1 μS / cm to 100 μS / cm in the state of 0.5 wt% metal fine particle dispersion.

（Ｄ）アルカリで処理する工程
次に（Ｂ）で得られた金属微粒子をアルカリで処理する工程に関して説明する。この工程は、金属微粒子をアルカリで処理することで、不純分の低減や酸化状態の調整を行う。使用するアルカリは、従来公知のアルカリを使用することが可能である。具体的には、アンモニア、三級アミン、四級アミンより選ばれる少なくとも１種以上が挙げられる。使用する酸は１種でもよく、２種類以上でもよく、不純物の低減や酸化状態の調整に好適なアルカリを金属微粒子によって適宜選択することができる。 (D) Process of treating with alkali Next, a process of treating the metal fine particles obtained in (B) with an alkali will be described. In this step, the metal fine particles are treated with an alkali to reduce impurities and adjust the oxidation state. As the alkali to be used, a conventionally known alkali can be used. Specific examples include at least one selected from ammonia, tertiary amines, and quaternary amines. The acid to be used may be one kind or two or more kinds, and an alkali suitable for reducing impurities and adjusting the oxidation state can be appropriately selected by metal fine particles.

アルカリでの処理は金属に対して０．００１〜１０重量％の範囲の量のアルカリで処理することが好ましく、さらには０．００２〜５重量％の範囲であることがより好ましい。アルカリの量が０．０１重量％未満の場合は、不純分の低減が困難であり、金属微粒子分散液のｐＨが２以下になる場合がある。アルカリの量が１０重量％を超える場合は、粒子が凝集する場合があるとともに、金属微粒子分散液のｐＨが１１を超える場合がある。アルカリによる処理は、金属微粒子と適量のアルカリを混合し、１０℃〜２００℃の温度で１〜６０分攪拌すればよい。温度が１０℃未満であると不純物の低減効果が得られにくく、２００℃を超えると金属微粒子が凝集する場合がある。   The treatment with alkali is preferably carried out with an amount of alkali in the range of 0.001 to 10% by weight relative to the metal, and more preferably in the range of 0.002 to 5% by weight. When the amount of alkali is less than 0.01% by weight, it is difficult to reduce the impure content, and the pH of the metal fine particle dispersion may be 2 or less. When the amount of alkali exceeds 10% by weight, the particles may aggregate and the pH of the metal fine particle dispersion may exceed 11. The treatment with alkali may be performed by mixing metal fine particles and an appropriate amount of alkali and stirring at a temperature of 10 ° C. to 200 ° C. for 1 to 60 minutes. If the temperature is less than 10 ° C, the effect of reducing impurities is difficult to obtain, and if it exceeds 200 ° C, the metal fine particles may aggregate.

攪拌後は（Ｂ）の工程と同様に従来公知の方法で不純分の低減を行うことができる。具体的には限外膜を用いて不純物を低減する方法、デカンテーションで沈殿した不純分を低減する方法、イオン交換膜やイオン交換樹脂でイオンを低減する方法などが挙げられる。処理の完了の目安は電気伝導度を用いることができ、０．５重量％の金属微粒子分散液の状態で電気伝導度が１μＳ／ｃｍ〜１５μＳ／ｃｍの範囲であることが好ましくｐＨが２〜１１の範囲であることが好ましい。   After the stirring, the impurity content can be reduced by a conventionally known method as in the step (B). Specific examples include a method of reducing impurities using an ultra membrane, a method of reducing impurities precipitated by decantation, and a method of reducing ions with an ion exchange membrane or ion exchange resin. As a measure of completion of the treatment, electric conductivity can be used, and the electric conductivity is preferably in the range of 1 μS / cm to 15 μS / cm in the state of 0.5 wt% of fine metal particle dispersion, and the pH is 2 to 2. The range is preferably 11.

ここで（Ｃ）の酸による処理及び（Ｄ）のアルカリによる処理は、（Ｂ）の工程で得られた金属微粒子に対して、酸処理→アルカリ処理の順番で行う場合に限定されない。例えばこれらの処理を実行する順番を入れ替えて、アルカリ処理→酸処理の順に行ってもよい。この場合には、先に行われるアルカリ処理後の０．５重量％における金属微粒子分散液の電気伝導度が１μＳ／ｃｍ〜１００μＳ/ｃｍの範囲に調整され、酸処理後の同じく電気伝導度が１μＳ／ｃｍ〜１５μＳ/ｃｍの範囲、ｐＨが２〜１１の範囲に調整される。   Here, the treatment with the acid of (C) and the treatment with the alkali of (D) are not limited to the case where the metal fine particles obtained in the step of (B) are performed in the order of acid treatment → alkali treatment. For example, the order in which these treatments are performed may be changed, and the alkali treatment may be performed in the order of acid treatment. In this case, the electrical conductivity of the metal fine particle dispersion at 0.5% by weight after the alkali treatment previously performed is adjusted to a range of 1 μS / cm to 100 μS / cm, and the electrical conductivity after the acid treatment is the same. A range of 1 μS / cm to 15 μS / cm and a pH of 2 to 11 are adjusted.

また、上述の例では、（Ａ）、（Ｃ）、（Ｄ）の工程の後に、各々（Ｂ）の工程を実行する場合について説明したが、これら全ての工程の後で不純物の低減を行うことは必須ではない。最終的に得られる金属微粒子分散液の表面電荷量や電気伝導度を上述の範囲内に調整することができれば、工程（Ｄ）の後に一括して工程（Ｂ）を実施して不純物の低減を行ってもよい。   Further, in the above-described example, the case where the process (B) is performed after the processes (A), (C), and (D) has been described. However, impurities are reduced after all these processes. That is not essential. If the surface charge amount and electrical conductivity of the finally obtained metal fine particle dispersion can be adjusted within the above-mentioned range, the step (B) is collectively performed after the step (D) to reduce impurities. You may go.

これらの工程を経て調製された分散液に含まれている金属微粒子は、一次粒子が凝集して二次粒子を形成するが、この二次粒子径は５〜１００ｎｍの範囲に調整される。二次粒子径は、（Ａ）の金属の塩の還元工程にて添加される還元剤の量が少ないほど小さくなり、またこのとき添加される安定化剤の添加量が多いほど小さくなる。また（Ｃ）の酸による処理にて使用する酸の量が少ないほど二次粒子径は小さくなり、（Ｄ）のアルカリによる処理にて使用するアルカリの量が多いほど二次粒子径は小さくなる。二次粒子の径は、これらの変数を適切に調節することにより調整される。   In the metal fine particles contained in the dispersion prepared through these steps, the primary particles aggregate to form secondary particles, and the secondary particle diameter is adjusted to a range of 5 to 100 nm. The secondary particle size decreases as the amount of the reducing agent added in the metal salt reduction step (A) decreases, and decreases as the amount of the stabilizer added increases. Further, the smaller the amount of acid used in the treatment with the acid (C), the smaller the secondary particle size, and the larger the amount of alkali used in the treatment with the alkali (D), the smaller the secondary particle size. . The size of the secondary particles is adjusted by appropriately adjusting these variables.

また表面電荷量は、金属微粒子の一次粒子径（比表面積）や不純物の含有量に依存し、一次粒子径が小さいほど小さくなり、不純物の含有量が少ないほど小さくなる。（Ｂ）、（Ｃ）、（Ｄ）の各処理にて低減される不純物の例としては、原料となる金属塩を還元したときに生成される塩などが考えられこれらを脱塩することにより、既述の電気伝導度の調整などと並行して表面電荷量の調整が行われる。   The surface charge amount depends on the primary particle size (specific surface area) of metal fine particles and the content of impurities, and decreases as the primary particle size decreases, and decreases as the impurity content decreases. Examples of impurities that can be reduced by the treatments (B), (C), and (D) include salts generated when reducing the metal salt as a raw material, and by desalting them. The surface charge amount is adjusted in parallel with the adjustment of the electrical conductivity described above.

また金属微粒子の酸化状態は、（Ｃ）の酸による処理における酸の使用量、（Ｄ）のアルカリによる処理におけるアルカリの使用量に応じて変化する。これら酸やアルカリの使用量が多いと金属微粒子に含まれる酸化物の量は少なくなる。ここで既述のように金属微粒子の二次粒子は、酸の使用量が少ないほど、二次粒子径が小さくなることから、酸の使用量に対して酸化物の含有量と二次粒子径との間にはトレードオフの関係があることがわかっている。   The oxidation state of the metal fine particles varies depending on the amount of acid used in the treatment with the acid (C) and the amount of alkali used in the treatment with the alkali (D). When the amount of these acids and alkalis used is large, the amount of oxide contained in the metal fine particles decreases. Here, as described above, the secondary particle of the metal fine particle has a smaller secondary particle size as the amount of acid used is smaller. Therefore, the content of the oxide and the secondary particle size with respect to the amount of acid used are smaller. It is known that there is a trade-off relationship with.

このような工程を経て得られた金属微粒子分散液は、金属塩や還元剤、安定化剤や酸、アルカリの添加量などを予め行った実験などにより所望の特性を備えた金属微粒子が得られる条件を適切に把握しておく。これにより、一次粒子径が１〜３０ｎｍの範囲であり、二次粒子径は５〜１００ｎｍの範囲となり、金属微粒子分散液の微粒子濃度が０．５重量％のときの表面電荷量が０．５〜４５μｅｑ／ｇ、ｐＨが２〜１１、電気伝導度が１〜１５μＳ／ｃｍの範囲であり、金属微粒子の０．１〜３０重量％が酸化された金属微粒子分散液を得ることができる。   From the metal fine particle dispersion obtained through such steps, metal fine particles having desired characteristics can be obtained by experiments in which metal salts, reducing agents, stabilizers, acids and alkalis are added in advance. Know the conditions appropriately. As a result, the primary particle size is in the range of 1 to 30 nm, the secondary particle size is in the range of 5 to 100 nm, and the surface charge amount when the fine particle concentration of the metal fine particle dispersion is 0.5% by weight is 0.5. It is possible to obtain a metal fine particle dispersion in which ˜45 μeq / g, pH is 2 to 11, electric conductivity is in the range of 1 to 15 μS / cm, and 0.1 to 30 wt% of the metal fine particles are oxidized.

上述の特性を備えた金属微粒子分散液は、当該金属微粒子を原料として透明導電性被膜を形成しても高温下で酸化されにくく、優れた導電性を示し、耐久性の高いものが得られる。また前記金属微粒子分散液は、７０℃の保管条件にて、当該金属微粒子分散液を調製してから３０日後の二次粒子径の変化率が１．５倍以内であり、調製後、日数が経過しても表面抵抗の小さな透明導電性被膜を形成することができ、ポットライフが長い。   The metal fine particle dispersion having the above-mentioned characteristics is not easily oxidized at a high temperature even when a transparent conductive film is formed using the metal fine particles as a raw material, and exhibits excellent conductivity and high durability. In addition, in the metal fine particle dispersion, the change rate of the secondary particle diameter after 30 days from the preparation of the metal fine particle dispersion under storage conditions of 70 ° C. is within 1.5 times. Even if it passes, a transparent conductive film with a small surface resistance can be formed, and a pot life is long.

ここで上述の金属微粒子分散液から得られた金属微粒子は、Ａｇ、Ｐｄ、Ｃｕ、Ｒｕ、Ｒｈ、ＰｔおよびＡｕからなる群より選ばれる少なくとも１種以上の金属を含む金属微粒子であって、一次粒子径が１〜３０ｎｍの範囲であることと、当該金属微粒子の０．１〜３０重量％が酸化されていることと、を備えるという特徴を有する。このような特徴を備えた金属微粒子は、金属微粒子は、高温下でも酸化されにくく、透明導電膜以外でも種々の目的に利用が可能である。例えば、触媒用途、反射膜用途、センサー、金属顔料、イムノクロマト用途などが挙げられる。触媒用途に用いる場合には具体的には、この金属微粒子をアルミナや活性炭などの担体に担持させることにより、触媒としての利用が可能となる。例えばＰｄを含む金属微粒子を使用した触媒は、有機合成用触媒（水添反応、Ｈｅｃｋ反応など）や自動車触媒（ＤＯＣ触媒）、硝酸分解触媒、ガスセンサーなどに用いられ、Ｐｔを含むものは、燃料電池触媒、ガスセンサー、自動車三元触媒、などに用いることができる。   Here, the metal fine particles obtained from the above-mentioned metal fine particle dispersion are metal fine particles containing at least one metal selected from the group consisting of Ag, Pd, Cu, Ru, Rh, Pt and Au, The particle diameter is in the range of 1 to 30 nm, and 0.1 to 30% by weight of the metal fine particles are oxidized. The metal fine particles having such characteristics are not easily oxidized even at high temperatures, and can be used for various purposes other than the transparent conductive film. For example, a catalyst use, a reflective film use, a sensor, a metal pigment, an immunochromatography use, etc. are mentioned. When used for a catalyst, specifically, the metal fine particles are supported on a carrier such as alumina or activated carbon, so that it can be used as a catalyst. For example, a catalyst using fine metal particles containing Pd is used for an organic synthesis catalyst (hydrogenation reaction, Heck reaction, etc.), an automobile catalyst (DOC catalyst), a nitric acid decomposition catalyst, a gas sensor, and the like. It can be used for fuel cell catalysts, gas sensors, automobile three-way catalysts, and the like.

透明導電性被膜形成用塗布液
つぎに、本発明の透明導電性被膜形成用塗布液について説明する。本発明の透明導電性被膜形成用塗布液は、前記した金属微粒子分散液と極性溶媒とを含んでいる。本発明で用いられる極性溶媒としては、水；メタノール、エタノール、プロパノール、ブタノール、ジアセトンアルコール、フルフリルアルコール、テトラヒドロフルフリルアルコール、エチレングリコール、ヘキシレングリコールなどのアルコール類；酢酸メチルエステル、酢酸エチル
エステルなどのエステル類；ジエチルエーテル、エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、エチレングリコールモノブチルエーテル、ジエチレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテルなどのエーテル類；アセトン、メチルエチルケトン、アセチルアセトン、アセト酢酸エステルなどのケトン類などが挙げられる。これらは単独で使用してもよく、また２種以上混合して使用してもよい。ここで極性溶媒は基材へ透明導電性微粒子層を形成するときの造膜性を向上させる役割を果たしている。 Coating liquid for forming transparent conductive film
Next, the coating liquid for forming a transparent conductive film of the present invention will be described. The coating liquid for forming a transparent conductive film of the present invention contains the above-described metal fine particle dispersion and a polar solvent. Examples of polar solvents used in the present invention include water; alcohols such as methanol, ethanol, propanol, butanol, diacetone alcohol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, hexylene glycol; acetic acid methyl ester, ethyl acetate Esters such as esters; ethers such as diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether and diethylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, acetylacetone and acetoacetate And the like. These may be used singly or in combination of two or more. Here, the polar solvent plays a role of improving the film forming property when the transparent conductive fine particle layer is formed on the substrate.

このような透明導電性被膜形成用塗布液には、上記金属微粒子以外の導電性微粒子が含まれていてもよい。金属微粒子以外の導電性微粒子としては、公知の透明導電性無機酸化物微粒子あるいは微粒子カーボンなどを用いることができる。透明導電性無機酸化物微粒子としては、たとえば酸化錫、Ｓb、ＦまたはＰがドーピングざれた酸化錫、酸化インジウム、ＳｎまたはＦがドーピングされた酸化インジウム、酸化アンチモン、低次酸化チタンなどが挙げられる。   Such a coating liquid for forming a transparent conductive film may contain conductive fine particles other than the metal fine particles. As the conductive fine particles other than the metal fine particles, known transparent conductive inorganic oxide fine particles or fine particle carbon can be used. Examples of the transparent conductive inorganic oxide fine particles include tin oxide, tin oxide doped with Sb, F or P, indium oxide, indium oxide doped with Sn or F, antimony oxide, and low-order titanium oxide. .

このような導電性微粒子を含有すると、金属微粒子のみで透明導電性微粒子層を形成した場合と比較して、より透明性に優れた透明導電性微粒子層を形成することができる。また導電性微粒子を含有することによって、安価に透明導電性被膜付基材を製造することができる。   When such conductive fine particles are contained, it is possible to form a transparent conductive fine particle layer having more excellent transparency as compared with the case where the transparent conductive fine particle layer is formed only with metal fine particles. Moreover, the base material with a transparent conductive film can be manufactured cheaply by containing electroconductive fine particles.

これらの導電性微粒子の平均粒径は、１〜２００ｎｍ、好ましくは２〜１５０ｎｍの範囲にあることが好ましい。このような導電性微粒子は、前記分散液に含まれる金属微粒子１重量部当たり、４重量部以下の量で含まれていればよい。導電性微粒子が４重量部を超える場合は、導電性が低下し電磁波遮蔽効果が低下することがあるので好ましくない。   These conductive fine particles have an average particle diameter of 1 to 200 nm, preferably 2 to 150 nm. Such conductive fine particles may be contained in an amount of 4 parts by weight or less per 1 part by weight of the metal fine particles contained in the dispersion. When the amount of the conductive fine particles exceeds 4 parts by weight, the conductivity is lowered and the electromagnetic wave shielding effect may be lowered.

さらに本発明に係る透明導電性被膜形成用塗布液には、被膜形成後の金属微粒子のバインダーとして作用するマトリックス成分が含まれていてもよい。このようなマトリックス成分としては、シリカや有機樹脂からなるものが好ましく、具体的には、シリカではアルコキシシランなどの有機ケイ素化合物の加水分解重縮合物またはアルカリ金属ケイ酸塩水溶液を脱アルカリして得られるケイ酸重縮合物、あるいは塗料用樹脂などが挙げられる。   Furthermore, the coating liquid for forming a transparent conductive film according to the present invention may contain a matrix component that acts as a binder for metal fine particles after the film is formed. Such a matrix component is preferably composed of silica or an organic resin. Specifically, in silica, a hydrolyzed polycondensate of an organosilicon compound such as alkoxysilane or an alkali metal silicate aqueous solution is dealkalized. Examples thereof include silicic acid polycondensates and paint resins.

また有機樹脂としては、ペンタエリスリトールトリアクリレート、ペンタエリスリトールテトラアクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールテトラアクリレート、ジトリメチロールプロパンテトラ（メタ）アクリレート、ジペンタエリスリトールヘキサアクリレート、メチルメタクリレート、エチルメタクリレート、ブチルメタクリレート、イソブチルメタクリレート、２−エチルヘキシルメテクリレート、イソデシルメテクリレート、n−ラウリルアクリレート、ｎ−ステアリルアクリレート、１，６−ヘキサンジオールジメタクリレート、パーフルオロオクチルエチルメタクリレート、トリフロロエチルメタクリレート、ウレタンアクリレート等が挙げられる。このマトリックスは、分散液に含まれる前記金属微粒子１重量部当たり、０.０１〜０.５重量部、好ましくは０.０３〜０.３重量部の量で含まれていればよい。   Organic resins include pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexaacrylate, methyl methacrylate, ethyl methacrylate. Butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, n-lauryl acrylate, n-stearyl acrylate, 1,6-hexanediol dimethacrylate, perfluorooctylethyl methacrylate, trifluoroethyl methacrylate, Examples thereof include urethane acrylate. This matrix may be contained in an amount of 0.01 to 0.5 parts by weight, preferably 0.03 to 0.3 parts by weight, per 1 part by weight of the metal fine particles contained in the dispersion.

また、本発明の金属微粒子は分散性、安定性（分散状態の経時的な安定性）に優れているので必ずしも必要はないが、金属微粒子の分散性をより向上させるため、透明導電性被膜形成用塗布液中に有機系安定化剤が含まれていてもよい。このような有機系安定化剤として具体的には、ゼラチン、ポリビニルアルコール、ポリビニルピロリドン、ポリアクリル酸、ヒドロキシプロピルセルロース、およびシュウ酸、マロン酸、コハク酸、グルタール酸、アジピン酸、セバシン酸、マレイン酸、フマル酸、フタル酸、クエン酸などの多価カルボン酸およびその塩、複素環化合物あるいはこれらの混合物などが挙げられる。   In addition, although the metal fine particles of the present invention are excellent in dispersibility and stability (stability over time in the dispersion state), it is not always necessary. However, in order to further improve the dispersibility of the metal fine particles, a transparent conductive film is formed. An organic stabilizer may be contained in the coating liquid for use. Specific examples of such organic stabilizers include gelatin, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylic acid, hydroxypropyl cellulose, and oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid. Examples thereof include polyvalent carboxylic acids such as acid, fumaric acid, phthalic acid, and citric acid and salts thereof, heterocyclic compounds, and mixtures thereof.

このような有機系安定化剤は、分散液に含まれる金属微粒子１重量部に対し、０.００５〜０.５重量部、好ましくは０.００５〜０.２重量部含まれていればよい。有機系安定化剤の量が０.００５重量部未満の場合は充分な分散性と安定性が得られないことがあり、０.５重量部を超えてもさらに分散性や安定性が向上することもなく、残留する有機安定化剤が多くなりこれにより導電性が阻害されることがある。   Such an organic stabilizer may be contained in an amount of 0.005 to 0.5 parts by weight, preferably 0.005 to 0.2 parts by weight, with respect to 1 part by weight of the metal fine particles contained in the dispersion. . When the amount of the organic stabilizer is less than 0.005 parts by weight, sufficient dispersibility and stability may not be obtained, and even when the amount exceeds 0.5 parts by weight, dispersibility and stability are further improved. Of course, the remaining organic stabilizer increases, which may impair the conductivity.

このような透明導電性被膜形成用塗布液を使用すれば、１０２〜１０４Ω／□の表面抵抗を有する透明導電性微粒子層を形成することができるので、電磁波、およびこの電磁波の放出に伴って生じる電磁場を効果的に遮蔽することができる。特に、金属微粒子の０．１〜３０重量％が酸化されて、特定範囲の表面電荷量、電気伝導度を有しているの分散液は、分散性や安定性に優れることから、このような金属微粒子分散液を含む透明導電性被膜形成用塗布液についてもポットライフが長くなる。また、この透明導電性被膜形成用塗布液を用いると導電性、電磁遮蔽性に優れるとともに、信頼性が高い透明導電性被膜が形成された透明導電性被膜付基材を得ることができる。 If such a coating liquid for forming a transparent conductive film is used, a transparent conductive fine particle layer having a surface resistance of 10 2 to 10 4 Ω / □ can be formed. The accompanying electromagnetic field can be effectively shielded. In particular, a dispersion liquid in which 0.1 to 30% by weight of metal fine particles are oxidized to have a surface charge amount and electric conductivity in a specific range is excellent in dispersibility and stability. The pot life of the coating liquid for forming a transparent conductive film containing the metal fine particle dispersion is also increased. Moreover, when this coating liquid for forming a transparent conductive film is used, it is possible to obtain a substrate with a transparent conductive film on which a transparent conductive film having excellent conductivity and electromagnetic shielding properties and high reliability is formed.

また、この金属微粒子分散液は、分散性や安定性に優れているので有機安定化剤の使用量を少なくでき、塗膜を形成した後に有機安定化剤を除去することが容易であり、また有機安定化剤が残存して導電性を阻害することを抑制することができる。また、従来のように有機安定化剤を除去するため被膜形成後の基材を４００℃以上の高温で焼成する必要がなく、低温で除去することができるので高温焼成による金属微粒子の凝集、融着を防止できるとともに、得られる被膜のへーズの劣化を防止できる。   Further, since this metal fine particle dispersion is excellent in dispersibility and stability, the amount of the organic stabilizer used can be reduced, and it is easy to remove the organic stabilizer after forming the coating film. It can suppress that an organic stabilizer remains and inhibits electroconductivity. In addition, in order to remove the organic stabilizer as in the prior art, it is not necessary to calcinate the substrate after forming the film at a high temperature of 400 ° C. or higher, and it can be removed at a low temperature. In addition to preventing adhesion, deterioration of the haze of the resulting film can be prevented.

透明導電性被膜付基材
次に、本発明に係る透明導電性被膜付基材について説明する。本発明に係る透明導電性被膜付基材では、前記した透明導電性被膜形成用塗布液から形成した透明導電性微粒子層が、ガラス、プラスチック、セラミックなどからなるフィルム、シートあるいはその他の成形体などの基材上に形成されている。 Next, the base material with a transparent conductive film according to the present invention will be described. In the substrate with a transparent conductive film according to the present invention, the transparent conductive fine particle layer formed from the coating liquid for forming a transparent conductive film described above is a film, sheet, or other molded body made of glass, plastic, ceramic, or the like. Formed on the substrate.

［透明導電性微粒子層］
透明導電性微粒子層の膜厚は、約５〜２００ｎｍ、さらには１０〜１５０ｎｍの範囲にあることがより好ましく、この範囲の膜厚であれば電磁遮蔽効果に優れた透明導電性被膜付基材を得ることができる。このような透明導電性微粒子層には、必要に応じて、上記金属微粒子以外の導電性微粒子、マトリックス成分、有機系安定化剤を含んでいてもよく、具体的には、透明導電性被膜形成用塗布液の説明にて列記したものと同様の有機系安定化剤が挙げられる。 [Transparent conductive fine particle layer]
The film thickness of the transparent conductive fine particle layer is more preferably in the range of about 5 to 200 nm, and more preferably in the range of 10 to 150 nm. If the film thickness is in this range, the substrate with a transparent conductive film excellent in electromagnetic shielding effect Can be obtained. Such a transparent conductive fine particle layer may contain conductive fine particles other than the above metal fine particles, a matrix component, and an organic stabilizer, if necessary, specifically, forming a transparent conductive film. Organic stabilizers similar to those listed in the description of the coating liquid for coating.

［透明被膜］
本発明に係る透明導電性被膜付基材では、前記透明導電性微粒子層の上に、前記透明導電性微粒子層よりも屈折率の低い透明被膜が形成されている。透明被膜の膜厚は、５０〜３００ｎｍ、好ましくは８０〜２００ｎｍの範囲にあることが好ましい。このような透明被膜は、たとえば、シリカ、チタニア、ジルコニアなどの無機酸化物、およびこれらの複合酸化物などから形成される。本発明では、透明被膜として、特に加水分解性有機ケイ素化合物の加水分解重縮合物、またはアルカリ金属ケイ酸塩水溶液を脱アルカリして得られるケイ酸重縮合物からなるシリカ系被膜が好ましい。このような透明被膜が形成された透明導電性被膜付基材は、反射防止性能に優れている。 [Transparent coating]
In the substrate with a transparent conductive film according to the present invention, a transparent film having a refractive index lower than that of the transparent conductive fine particle layer is formed on the transparent conductive fine particle layer. The film thickness of the transparent coating is 50 to 300 nm, preferably 80 to 200 nm. Such a transparent film is formed from, for example, inorganic oxides such as silica, titania and zirconia, and composite oxides thereof. In the present invention, a silica-based film made of a hydrolyzable polycondensate of a hydrolyzable organosilicon compound or a silicate polycondensate obtained by dealkalizing an alkali metal silicate aqueous solution is particularly preferable as the transparent film. The base material with a transparent conductive film on which such a transparent film is formed is excellent in antireflection performance.

また、上記透明被膜中には、必要に応じて、フッ化マグネシウムなどの低屈折率材料で構成された微粒子、染料、顔料などの添加剤や、特開平７−１０５２２、特開２００２−７９６１６で挙げられている多孔質シリカ微粒子や中空シリカ微粒子を含んでもよい。   Further, in the transparent film, if necessary, additives such as fine particles, dyes, pigments and the like made of a low refractive index material such as magnesium fluoride, and JP-A-7-10522 and JP-A-2002-79616 The mentioned porous silica fine particles and hollow silica fine particles may be included.

透明導電性被膜付基材の製造方法
本発明に係る透明導電性被膜付基材は以下のようにして
製造することができる。
［透明導電性微粒子層の形成］
まず、前述の金属微粒子分散液と極性溶媒とを含む透明導電性被膜形成用塗布液を基材上に塗布・乾燥して透明導電性微粒子層を形成する。透明導電性被膜形成用塗布液中の金属微粒子は、０.０５〜１０重量％、好ましくは０.１〜８重量％の量で含まれていることが望ましい。また、このような透明導電性被膜形成用塗布液には、金属微粒子以外の導電性微粒子が添加されていてもよい。このような導電性微粒子としては透明導電性被膜形成用塗布液の説明にて列記したものと同様のものと同様の導電性微粒子が挙げられる。 The manufacturing method of the base material with a transparent conductive film The base material with a transparent conductive film which concerns on this invention can be manufactured as follows.
[Formation of transparent conductive fine particle layer]
First, a transparent conductive fine particle layer is formed by applying and drying a transparent conductive film-forming coating solution containing the above-mentioned metal fine particle dispersion and a polar solvent on a substrate. The fine metal particles in the coating liquid for forming a transparent conductive film are desirably contained in an amount of 0.05 to 10% by weight, preferably 0.1 to 8% by weight. In addition, conductive fine particles other than metal fine particles may be added to the coating liquid for forming a transparent conductive film. Examples of such conductive fine particles include the same conductive fine particles as those listed in the description of the coating liquid for forming a transparent conductive film.

透明導電性微粒子層を形成する方法としては、たとえば、前記透明導電性被膜形成用塗布液をディッピング法、スピナー法、スプレー法、ロールコーター法、フレキソ印刷法、グラビア印刷などの方法で、基材上に塗布したのち、常温〜約９０℃の範囲の温度で乾燥する。透明導電性被膜形成用塗布液中に上記のようなマトリックス成分が含まれている場合には、マトリックス成分の硬化処理を行ってもよい。   As a method for forming the transparent conductive fine particle layer, for example, the coating solution for forming the transparent conductive film is formed by a method such as dipping, spinner, spray, roll coater, flexographic, gravure, etc. After coating on top, it is dried at a temperature ranging from room temperature to about 90 ° C. When the matrix component as described above is contained in the coating liquid for forming a transparent conductive film, the matrix component may be cured.

硬化処理としては、従来公知の加熱硬化、電磁波照射やアンモニアガスなどによるガス硬化などの方法やＵＶ（Ultra Violet）光やＥＢ（Electron Beam）での硬化が挙げられる。上記のような方法によって形成された透明導電性微粒子層の膜厚は、約５０〜２００ｎｍの範囲が好ましく、この範囲の膜厚であれば電磁遮蔽効果に優れた透明導電性被膜付基材を得ることができる。   Examples of the curing treatment include conventionally known heat curing, electromagnetic wave irradiation, gas curing with ammonia gas, and the like, and curing with UV (Ultra Violet) light or EB (Electron Beam). The film thickness of the transparent conductive fine particle layer formed by the method as described above is preferably in the range of about 50 to 200 nm. If the film thickness is in this range, a substrate with a transparent conductive film excellent in electromagnetic shielding effect is obtained. Can be obtained.

［透明被膜の形成］
ついで該微粒子層上に透明被膜形成用塗布液を塗布して前記透明導電性微粒子層上に該微粒子層よりも屈折率の低い透明被膜を形成する。透明被膜の膜厚は、５０〜３００ｎｍ、好ましくは８０〜２００ｎｍの範囲であることが好ましく、このような範囲の膜厚であると優れた反射防止性を発揮する。透明被膜の形成方法としては、特に制限はなく、この透明被膜の材質に応じて、真空蒸発法、スパッタリング法、イオンプレーティング法などの乾式薄膜形成方法、あるいは上述したようなディッピング法、スピナー法、スプレー法、ロールコーター法、フレキソ印刷法、グラビア印刷などの湿式薄膜形成方法を採用することができる。 [Formation of transparent film]
Next, a coating liquid for forming a transparent film is applied on the fine particle layer to form a transparent film having a refractive index lower than that of the fine particle layer on the transparent conductive fine particle layer. The film thickness of the transparent coating is preferably in the range of 50 to 300 nm, and preferably in the range of 80 to 200 nm. When the film thickness is in such a range, excellent antireflection properties are exhibited. The method for forming the transparent film is not particularly limited, and depending on the material of the transparent film, a dry thin film forming method such as a vacuum evaporation method, a sputtering method, or an ion plating method, or the dipping method or spinner method as described above. Further, a wet thin film forming method such as a spray method, a roll coater method, a flexographic printing method, or a gravure printing can be employed.

上記透明被膜を湿式薄膜形成方法で形成する場合、従来公知の透明被膜形成用塗布液を用いることができる。このような透明被膜形成用塗布液としては、具体的に、シリカ、チタニア、ジルコニアなどの無機酸化物、またはこれらの複合酸化物を透明被膜形成成分として含む塗布液が用いられる。本発明では、透明被膜形成用塗布液として加水分解性有機ケイ素化合物の加水分解重縮合物、またはアルカリ金属ケイ酸塩水溶液を脱アルカリして得られるケイ酸液を含むシリカ系透明被膜形成用塗布液か有機樹脂と中空シリカを組み合わせた系が好ましく、特に下記一般式［１］で表されるアルコキシシランの加水分解重縮合物を含有していることが好ましい。このような塗布液から形成されるシリカ系被膜は、金属微粒子含有の導電性微粒子層よりも屈折率が小さく、得られる透明被膜付基材は反射防止性に優れている。   When the transparent film is formed by a wet thin film forming method, a conventionally known coating liquid for forming a transparent film can be used. As such a coating liquid for forming a transparent film, specifically, a coating liquid containing an inorganic oxide such as silica, titania, zirconia, or a composite oxide thereof as a transparent film forming component is used. In the present invention, a silica-based transparent film-forming coating containing a hydrolyzable polycondensate of a hydrolyzable organosilicon compound or a silicic acid solution obtained by dealkalizing an alkali metal silicate aqueous solution as a coating film for forming a transparent film A system in which liquid or organic resin and hollow silica are combined is preferable, and it is particularly preferable to contain a hydrolyzed polycondensate of alkoxysilane represented by the following general formula [1]. The silica-based film formed from such a coating solution has a refractive index smaller than that of the conductive fine particle layer containing metal fine particles, and the obtained substrate with a transparent film is excellent in antireflection properties.

アルコキシシランの一般式
ＲaＳi(ＯＲ')４−ａ…［１］
（式中、Ｒはビニル基、アリール基、アクリル基、炭素数１〜８のアルキル基、水素原子またはハロゲン原子であり、Ｒ'はビニル基、アリール基、アクリル基、炭系数１〜８のアルキル基、−Ｃ２Ｈ４ＯＣｎＨ２ｎ＋１（ｎ＝１〜４）または水素原子であり、ａは０〜３の整数である。）このようなアルコキシランとしては、テトラメトキシシラン、テトラエトキシシラン、テトライソプロポキシシラン、テトラブトキシシラン、テトラオクチルシランメチルトリメトキシシラン、メチルトリエトキシシラン、エチルトリエトキシシラン、メチルトリイソプロポキシシラン、ビニルトリメトキシシラン、フェニルトリメトキシシラン、ジメチルジメトキシシランなどが挙げられる。 General formula of alkoxysilane
RaSi (OR ') 4-a ... [1]
(In the formula, R is a vinyl group, an aryl group, an acrylic group, an alkyl group having 1 to 8 carbon atoms, a hydrogen atom or a halogen atom, and R ′ is a vinyl group, an aryl group, an acrylic group, or a carbon system having 1 to 8 carbon atoms. An alkyl group, —C 2 H 4 OC n H 2n + 1 (n = 1 to 4) or a hydrogen atom, and a is an integer of 0 to 3. ) Examples of such alkoxylane include tetramethoxysilane, tetraethoxy Silane, tetraisopropoxysilane, tetrabutoxysilane, tetraoctylsilane methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, methyltriisopropoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, etc. Can be mentioned.

上記のアルコキシシランの１種または２種以上を、たとえば水−アルコール混合溶媒中で酸触媒の存在下、加水分解すると、アルコキシシランの加水分解重縮合物を含む透明被膜形成用塗布液が得られる。このような塗布液中に含まれる被膜形成成分の濃度は、酸化物換算で０.５〜２.０重量％であることが好ましい。本発明で使用される透明被膜形成用塗布液は、前記透明導電性被膜形成用塗布液の場合と同様に、脱イオン処理を行い、透明導電性塗布液のイオン濃度を前記透明導電性被膜形成用塗布液中の濃度と同じレベルまで低減させてもよい。   When one or more of the above alkoxysilanes are hydrolyzed in the presence of an acid catalyst, for example, in a water-alcohol mixed solvent, a coating solution for forming a transparent film containing a hydrolyzed polycondensate of alkoxysilane is obtained. . It is preferable that the density | concentration of the film formation component contained in such a coating liquid is 0.5 to 2.0 weight% in conversion of an oxide. The coating liquid for forming a transparent film used in the present invention is subjected to deionization treatment as in the case of the coating liquid for forming a transparent conductive film, and the ion concentration of the transparent conductive coating liquid is determined to form the transparent conductive film. You may reduce to the same level as the density | concentration in the application liquid.

さらにまた、本発明で使用される透明被膜形成用塗布液には、フッ化マグネシウムなどの低屈折率材料や多孔質シリカや中空シリカで構成された微粒子、透明被膜の透明度および反射防止性能を阻害しない程度に少量の導電性微粒子および／または染料または顔料などの添加剤が含まれていてもよい。本発明では、このような透明被膜形成用塗布液を塗布して形成した被膜を、乾燥時、または乾燥後に、５０℃以上で加熱するか、未硬化の被膜に可視光線よりも波長の短い紫外線、電子線、Ｘ線、γ線などの電磁波を照射するか、あるいはアンモニアなどの活性ガス雰囲気中に晒してもよい。このようにすると、被膜形成成分の硬化が促進され、得られる透明被膜の硬度が高くなる。   Furthermore, the coating liquid for forming a transparent film used in the present invention inhibits the low refractive index material such as magnesium fluoride, fine particles composed of porous silica or hollow silica, transparency and antireflection performance of the transparent film. A small amount of conductive fine particles and / or additives such as dyes or pigments may be included. In the present invention, a film formed by applying such a coating solution for forming a transparent film is heated at 50 ° C. or higher at the time of drying or after drying, or ultraviolet light having a wavelength shorter than that of visible light is applied to an uncured film. Further, electromagnetic waves such as electron beams, X-rays and γ-rays may be irradiated or exposed to an active gas atmosphere such as ammonia. If it does in this way, hardening of a film formation ingredient will be accelerated and the hardness of the transparent film obtained will become high.

さらに、透明被膜形成用塗布液を塗布して被膜を形成する際に、透明導電性微粒子層を常温〜９０℃に保持しながら透明被膜形成用塗布液を塗布して、前記のような処理を行うと、透明被膜の表面にリング状の凹凸が形成し、ギラツキの少ないアンチグレアの透明被膜付基材が得られる。   Further, when the transparent coating film forming coating solution is applied to form the coating film, the transparent coating film forming coating solution is applied while maintaining the transparent conductive fine particle layer at room temperature to 90 ° C. When it does, the ring-shaped unevenness | corrugation will form in the surface of a transparent film, and the base material with a transparent film of an anti-glare with few glare will be obtained.

表示装置
本発明に係る透明導電性被膜付基材は、所定の特性を備えた金属微粒子分散液に含まれる金属微粒子から透明導電性微粒子が形成されているので、電磁遮蔽に必要な１０２〜１０４Ω／□の範囲の表面抵抗を有し、かつ可視光領域および近赤外領域で充分な反射防止性能を有しており、このような透明導電性被膜付基材は、表示装置の前面板として好適に用いられる。 A transparent conductive film-coated substrate according to the display device the present invention, since the transparent conductive microparticles is formed from a metal fine particles contained in the fine metal particle dispersion having a predetermined characteristic, 10 2 ~ required electromagnetic shielding It has a surface resistance in the range of 10 4 Ω / □ and sufficient antireflection performance in the visible light region and the near infrared region. Such a substrate with a transparent conductive film is used in a display device. It is suitably used as a front plate.

本発明に係る表示装置は、ブラウン管（ＣＲＴ）、蛍光表示管（ＦＩＰ）、プラズマディスプレイ（ＰＤＰ）、液晶用ディスプレイ（ＬＣＤ）などのような電気的に画像を表示する装置であり、上記のような透明導電性被膜付基材で構成された前面板を備えている。従来の前面板を備えた表示装置を作動させると、前面板に画像が表示されると同時に電磁波が前面板から放出されることが知られている。本発明に係る表示装置では、前面板が１０２〜１０４Ω／□の表面抵抗を有する透明導電性被膜付基材で構成されているので、このような電磁波、およびこの電磁波の放出に伴って生じる電磁場を効果的に遮蔽することができる。 The display device according to the present invention is a device that electrically displays an image such as a cathode ray tube (CRT), a fluorescent display tube (FIP), a plasma display (PDP), a liquid crystal display (LCD), and the like. A front plate made of a substrate with a transparent conductive film. It is known that when a display device having a conventional front plate is operated, an electromagnetic wave is emitted from the front plate at the same time as an image is displayed on the front plate. In the display device according to the present invention, the front plate is composed of a substrate with a transparent conductive film having a surface resistance of 10 2 to 10 4 Ω / □, and accordingly, with such an electromagnetic wave and the emission of the electromagnetic wave. The electromagnetic field generated can be effectively shielded.

また、表示装置の前面板で反射光が生じると、この反射光によって表示画像が見にくくなるが、本発明に係る表示装置では、前面板が可視光領域および近赤外領域で充分な反射防止性能を有する透明導電性被膜付基材で構成されているので、このような反射光を効果的に防止することができる。さらに、ブラウン管の前面板が、本発明に係る透明導電性被膜付基材で構成され、この透明導電性被膜のうち、透明導電性微粒子層、その上に形成された透明被膜の少なくとも一方に少量の染料または顔料が含まれている場合には、これらの染料または顔料がそれぞれ固有な波長の光を吸収し、これによりブラウン管から放映される表示画像のコントラストを向上させることができる。   In addition, when reflected light is generated on the front plate of the display device, the display image is difficult to see due to the reflected light. In the display device according to the present invention, the front plate has sufficient antireflection performance in the visible light region and the near infrared region. Since it is comprised with the base material with a transparent conductive film which has this, such reflected light can be prevented effectively. Furthermore, the front plate of the cathode ray tube is composed of a substrate with a transparent conductive film according to the present invention, and among these transparent conductive films, a small amount is added to at least one of the transparent conductive fine particle layer and the transparent film formed thereon. When these dyes or pigments are contained, each of these dyes or pigments absorbs light having a specific wavelength, thereby improving the contrast of a display image broadcast from the cathode ray tube.

本発明によれば以下の効果がある。金属微粒子と、分散媒とを含む金属微粒子分散液において、前記金属微粒子は、Ａｇ、Ｐｄ、Ｃｕ、Ｒｕ、Ｒｈ、白金および金からなる群より選ばれる少なくとも１種以上の金属を含み、その一次粒子径が１〜３０ｎｍの範囲であり、二次粒子径が５〜１００ｎｍの範囲であり、当該金属微粒子の０．１〜３０重量％が酸化されていることと、金属微粒子分散液の微粒子濃度が０．５重量％のときの表面電荷量が０．５〜４５μｅｑ／ｇの範囲であり、電気伝導度が１〜１５μＳ／ｃｍの範囲であることと、を備えている。これによって、当該分散液に含まれる金属微粒子は高い導電性を保持するとともに、高温下でも酸化が抑制され、合金的特性を有し、導電性被膜に用いた場合に金属の酸化やイオン化を抑制することができ、粒子成長が抑制されるので導電性や光透過率の低下を抑制することができる。さらに、粒子表面が酸化されているものは、表面電荷量が高く、分散性や安定性に優れている。   The present invention has the following effects. In a metal fine particle dispersion containing metal fine particles and a dispersion medium, the metal fine particles contain at least one metal selected from the group consisting of Ag, Pd, Cu, Ru, Rh, platinum and gold, and the primary The particle size is in the range of 1 to 30 nm, the secondary particle size is in the range of 5 to 100 nm, 0.1 to 30% by weight of the metal fine particles are oxidized, and the fine particle concentration of the metal fine particle dispersion The surface charge amount is 0.5 to 45 μeq / g and the electrical conductivity is 1 to 15 μS / cm. As a result, the fine metal particles contained in the dispersion retain high electrical conductivity, and are suppressed from oxidation even at high temperatures, have alloy characteristics, and suppress metal oxidation and ionization when used in conductive coatings. Since particle growth is suppressed, it is possible to suppress a decrease in conductivity and light transmittance. Further, those whose particle surfaces are oxidized have a high surface charge amount and are excellent in dispersibility and stability.

このような金属微粒子分散液を含む透明導電性被膜形成用塗布液はポットライフが長く、この透明導電性被膜形成用塗布液を用いると導電性、電磁遮蔽性に優れるとともに、信頼性が高い透明導電性被膜が形成された透明導電性被膜付基材を得ることができる。また、この金属微粒子分散液は、分散性や安定性に優れているので有機安定化剤の使用量を少なくでき、塗膜を形成した後に有機安定化剤を除去することが容易であり、また有機安定化剤が残存して導電性を阻害することを抑制することができる。また、従来のように有機安定化剤を除去するため被膜形成後の基材を４００℃以上の高温で焼成する必要がなく、低温で除去することができるので高温焼成による金属微粒子の凝集、融着を防止できるとともに、得られる被膜のへーズの劣化を防止できる。   A coating liquid for forming a transparent conductive film containing such a metal fine particle dispersion has a long pot life, and when this coating liquid for forming a transparent conductive film is used, it has excellent conductivity and electromagnetic shielding properties and is highly reliable and transparent. A substrate with a transparent conductive film on which a conductive film is formed can be obtained. Further, since this metal fine particle dispersion is excellent in dispersibility and stability, the amount of the organic stabilizer used can be reduced, and it is easy to remove the organic stabilizer after forming the coating film. It can suppress that an organic stabilizer remains and inhibits electroconductivity. In addition, in order to remove the organic stabilizer as in the prior art, it is not necessary to calcinate the substrate after forming the film at a high temperature of 400 ° C. or higher, and it can be removed at a low temperature. In addition to preventing adhesion, deterioration of the haze of the resulting film can be prevented.

また本発明に係る金属微粒子の製造方法によれば、上記した金属微粒子を効率よく得ることができる。本発明によれば、導電性、電磁遮蔽性に優れるとともに信頼性が高い透明導電性被膜を形成しうるポットライフの長い透明導電性被膜形成用塗布液を得ることができる。   Further, according to the method for producing metal fine particles according to the present invention, the metal fine particles described above can be obtained efficiently. ADVANTAGE OF THE INVENTION According to this invention, the coating liquid for transparent conductive film formation with a long pot life which can form a highly reliable transparent conductive film while being excellent in electroconductivity and electromagnetic shielding can be obtained.

そして本発明によれば、導電性、電磁遮蔽性に優れるとともに、信頼性が高い透明導電性被膜が形成された透明導電性被膜付基材を得ることができる。このような透明導電性被膜付基材を表示装置の前面板として用いれば、電磁遮蔽性に優れるとともに反射防止性にも優れた表示装置を得ることができる。   And according to this invention, while being excellent in electroconductivity and electromagnetic shielding, the base material with a transparent conductive film in which the transparent conductive film with high reliability was formed can be obtained. If such a substrate with a transparent conductive film is used as a front plate of a display device, a display device having excellent electromagnetic shielding properties and antireflection properties can be obtained.

このほか本発明で得られた金属微粒子は、高温での酸化が抑制されているため、導電材料以外での用途での利用が可能である。例えば、金属微粒子を各種担体に担持させることによって、高温で使用する触媒用途やガスセンサーなどの用途での利用も可能である。   In addition, since the metal fine particles obtained in the present invention are suppressed from oxidation at high temperatures, they can be used in applications other than conductive materials. For example, by supporting metal fine particles on various carriers, it can be used in applications such as a catalyst used at a high temperature and a gas sensor.

以下、本発明を実施例により説明するが、本発明はこれらの実施例に何ら限定されるものではない。
［測定方法］
本願で採用した測定方法について以下に記す。
［１］金属微粒子の一次粒子径の測定
走査型電子顕微鏡（株式会社日立製作所製、Ｓ−５５００）により、試料（金属微粒子）を倍率３０万倍で写真撮影して確認した。
［２］金属微粒子二次粒子径の測定
微粒子の分散液を０．５％に純水を用いて希釈し、マイクロトラックＵＰＡ型（日機装（株）性）を用いて測定した。
［３］金属微粒子のｐＨ・電気伝導度の測定
微粒子の分散液を０．５％に純水を用いて希釈し、ｐＨメーター及び電気伝導度計を用いて２５℃の条件で測定した。 EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples at all.
[Measuring method]
The measurement method employed in the present application is described below.
[1] Measurement of primary particle size of metal fine particles
Using a scanning electron microscope (manufactured by Hitachi, Ltd., S-5500), the sample (metal fine particles) was photographed at a magnification of 300,000 and confirmed.
[2] Measurement of secondary particle size of metal fine particles
The fine particle dispersion was diluted to 0.5% with pure water and measured using Microtrac UPA (Nikkiso Co., Ltd.).
[3] Measurement of pH and electrical conductivity of fine metal particles
The fine particle dispersion was diluted to 0.5% with pure water, and measured using a pH meter and an electric conductivity meter at 25 ° C.

［４］金属微粒子の組成分析及び不純物量の分析
試料（金属微粒子分散液・金属微粒子担持触媒）を６００℃にて焼成し、残渣をアルカリ溶融剤にて溶融した後、２８質量％塩酸若しくは硝酸水溶液にて溶解し、溶解液を純水で希釈した後、ＩＣＰ誘導結合プラズマ発光分光分析装置ＳＰＳ１２００Ａ（セイコー電子株式会社製）にて測定した。また、陰イオン成分（Ｃｌ成分を含む）に関しては液体クロマトグラフィーを用いて測定した。この測定法で測定したハロゲン（Ｃｌ成分）以外の陰イオン及び金属微粒子以外の陽イオン成分を不純物量と定義し算出した。 [4] Composition analysis of metal fine particles and analysis of impurity content
The sample (metal fine particle dispersion / metal fine particle supported catalyst) was baked at 600 ° C., the residue was melted with an alkali melting agent, dissolved in 28% by mass hydrochloric acid or nitric acid aqueous solution, and the solution was diluted with pure water. Then, the measurement was performed with an ICP inductively coupled plasma emission spectrometer SPS1200A (Seiko Electronics Co., Ltd.). Further, the anion component (including Cl component) was measured using liquid chromatography. Anions other than halogen (Cl component) and cation components other than metal fine particles measured by this measurement method were defined and calculated as the amount of impurities.

[５]表面電荷量の測定
表面電位滴定装置（Ｍｕｔｅｋ(株)pcd−０３）を用いて、微粒子の分散液を０．５％に希釈し、０．００１Ｎのｐｏｌｙ−ジフェニルアンモニウムクロライドで滴定し表面電荷量（μｅｑ/ｇ）を求めた。
[６]金属微粒子の酸化状態の測定
微粒子分散液を１０５℃の条件で真空乾燥を行い得られた固形物、及び大気中で２００℃で乾燥させて得られた固形物をＸ線光電子分光分析装置を用いて測定し、酸化物量を算出するとともに、大気中２００℃乾燥と１０５℃真空乾燥の酸化物量の差を比較することによって酸化のされ易さを測定した。
［７］透明導電性被膜付基材膜特性の測定
表面抵抗、ヘーズ、ボトム反射率、視感反射率等の測定は、下記に記載した方法で製膜した、透明導電性被膜付基材を用い、表面抵抗を表面抵抗計（三菱油化(株)製:ＬＯＲＥＳＴＡ）で測定し、ヘーズをヘーズコンピューター（日本電色(株)製：３０００A）で測定した。反射率は反射率計（大塚電子(株)製：MCPD−３０００）を用いて測定し、波長４００〜７００ｎｍの範囲で反射率が最も低い反射率としこれをボトム反射率とした。 [5] Measurement of surface charge
Using a surface potential titrator (Mutek Co., Ltd. pcd-03), the fine particle dispersion was diluted to 0.5% and titrated with 0.001N poly-diphenylammonium chloride to obtain the surface charge (μeq / g). Asked.
[6] Measurement of oxidation state of fine metal particles
The solid matter obtained by vacuum drying the fine particle dispersion at 105 ° C. and the solid matter obtained by drying at 200 ° C. in the atmosphere were measured using an X-ray photoelectron spectrometer, and the amount of oxide was measured. While calculating, the ease of oxidation was measured by comparing the difference in the amount of oxide between 200 ° C. drying in air and 105 ° C. vacuum drying.
[7] Measurement of characteristics of substrate film with transparent conductive film
Surface resistance, haze, bottom reflectance, luminous reflectance, etc. are measured using a substrate with a transparent conductive film formed by the method described below, and the surface resistance is measured by a surface resistance meter (Mitsubishi Yuka Co., Ltd.). ): LORESTA) and haze was measured with a haze computer (Nippon Denshoku Co., Ltd .: 3000A). The reflectance was measured using a reflectance meter (manufactured by Otsuka Electronics Co., Ltd .: MCPD-3000), and the reflectance having the lowest reflectance in the wavelength range of 400 to 700 nm was defined as the bottom reflectance.

［８］透明導電性被膜付基材膜信頼性評価
（ｉ）耐過酸化水素性
透明導電性被膜付基材を１０％の過酸化水素に７２時間浸漬させ、浸漬前後の抵抗値の変化率を算出し下記の序列で判定した。
○：抵抗変化率１．２倍未満
△：抵抗変化率１．２倍以上〜１．５倍未満
×：抵抗変化率１．５倍以上
（ｉｉ）耐塩酸性
透明導電性被膜付基材を１０％の塩酸に７２時間浸漬させ、浸漬前後の抵抗値の変化率を算出し下記の序列で判定した。
○：抵抗変化率１．２倍未満
△：抵抗変化率１．２倍以上〜１．５倍未満
×：抵抗変化率１．５倍以上 [8] Base film reliability evaluation with transparent conductive film
(I) Hydrogen peroxide resistance
The substrate with a transparent conductive film was immersed in 10% hydrogen peroxide for 72 hours, and the change rate of the resistance value before and after immersion was calculated and judged according to the following order.
○: Resistance change rate less than 1.2 times
Δ: Resistance change rate 1.2 times to less than 1.5 times
X: Resistance change rate 1.5 times or more (ii) Hydrochloric acid resistance
The substrate with a transparent conductive film was immersed in 10% hydrochloric acid for 72 hours, and the change rate of the resistance value before and after immersion was calculated and judged according to the following order.
○: Resistance change rate less than 1.2 times
Δ: Resistance change rate 1.2 times to less than 1.5 times
×: Resistance change rate 1.5 times or more

[合成例１]
Ｐｄ微粒子分散液（Ｐｄコロイド溶液）の合成
クエン酸水溶液（濃度３０質量％）２１９ｇに還元剤として硫酸第一鉄１２２ｇを溶解させた溶液を調製した。そして、この溶液３４１ｇを、硝酸パラジウム水溶液（濃度２０質量％）３９ｇに室温で添加し、充分に混合することによりＰｄ粒子の分散液を調製した。限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて粗大不純物を除去し、濃縮しＰｄ換算濃度２．５％のＰｄコロイド溶液（１）を得た。得られたＰｄコロイド溶液の粒子径は、走査型電子顕微鏡（株式会社日立製作所製、Ｓ−５５００）で測定したところ平均粒子径は２ｎｍであった。 [Synthesis Example 1]
Synthesis of Pd fine particle dispersion (Pd colloidal solution)
A solution was prepared by dissolving 122 g of ferrous sulfate as a reducing agent in 219 g of an aqueous citric acid solution (concentration: 30% by mass). Then, 341 g of this solution was added to 39 g of an aqueous palladium nitrate solution (concentration 20% by mass) at room temperature, and thoroughly mixed to prepare a dispersion of Pd particles. Coarse impurities were removed using an ultrafilter (manufactured by ADVANTEC, Ultrafilter Q0500) and concentrated to obtain a Pd colloid solution (1) having a Pd equivalent concentration of 2.5%. When the particle diameter of the obtained Pd colloidal solution was measured with a scanning electron microscope (manufactured by Hitachi, Ltd., S-5500), the average particle diameter was 2 nm.

この得られたＰｄコロイド溶液（１）、１００ｇに１％塩酸を１ｇ添加し、１時間攪拌後、１％アンモニア水を１ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、ＩＣＰで濃度測定後２.５％に濃度調整を行いＰｄコロイド溶液（１−２）を得た。このＰｄコロイド溶液（１−２）を（実施例１）とし、Ｐｄコロイド溶液（１）を（比較例１）とする。（実施例１）、（比較例１）に係るコロイドの物性を（表１）に示した。   1 g of 1% hydrochloric acid was added to 100 g of the obtained Pd colloid solution (1) and stirred for 1 hour, and then 1 g of 1% aqueous ammonia was added and further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particle cut was performed with a centrifuge (G = 8000). After measuring the concentration with ICP, the concentration was adjusted to 2.5% to obtain a Pd colloid solution (1-2). This Pd colloidal solution (1-2) is referred to as (Example 1), and the Pd colloidal solution (1) is referred to as (Comparative Example 1). The physical properties of the colloid according to (Example 1) and (Comparative Example 1) are shown in (Table 1).

[合成例２]
Ｐｄ−Ｐｔ微粒子分散液（Ｐｄ−Ｐｔコロイド溶液）の合成
硝酸パラジウム（ＩＩ）水和物２２．５ｇ（パラジウム金属換算で９ｇ）と塩化白金酸６水和物２５ｇ（白金金属換算で９ｇ）を純水１６,０００ｇに溶解して得た金属塩水溶液に、錯化安定化剤として濃度５．０重量％のクエン酸３ナトリウム水溶液１,６６０ｇと還元剤として濃度０．１重量％の水素化ホウ素ナトリウム水溶液１４０ｇとを加え、窒素雰囲気下、２０℃で攪拌混合して、水に白金微粒子が分散してなる白金コロイド溶液を得た。ついで、白金コロイド溶液を限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて粗大不純物を除去し、濃縮し、金属換算で濃度２．５重量％のＰｄ−Ｐｔコロイド溶液（２）とした。 [Synthesis Example 2]
Synthesis of Pd-Pt fine particle dispersion (Pd-Pt colloidal solution)
To a metal salt aqueous solution obtained by dissolving 22.5 g of palladium (II) nitrate hydrate (9 g in terms of palladium metal) and 25 g of chloroplatinic acid hexahydrate (9 g in terms of platinum metal) in 16,000 g of pure water. Then, 1,660 g of an aqueous solution of trisodium citrate having a concentration of 5.0% by weight as a complexing stabilizer and 140 g of an aqueous solution of sodium borohydride having a concentration of 0.1% by weight as a reducing agent were added, and the reaction was performed at 20 ° C. in a nitrogen atmosphere. By stirring and mixing, a platinum colloid solution in which platinum fine particles were dispersed in water was obtained. Next, the platinum colloid solution was concentrated using an ultrafilter (ADVANTEC, Ultrafilter Q0500) to remove coarse impurities, concentrated, and a Pd-Pt colloid solution (2) having a concentration of 2.5% by weight in terms of metal. did.

この得られたＰｄ−Ｐｔコロイド溶液（２）、１００ｇに１％塩酸を５ｇ添加し、１時間攪拌後、１％アンモニア水を１ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、ＩＣＰで濃度測定後２.５％に濃度調整を行いＰｄ−Ｐｔコロイド溶液（２−２）を得た。このＰｄ−Ｐｔコロイド溶液（２−２）を（実施例２）とし、Ｐｄ−Ｐｔコロイド溶液（２）を（比較例２）とする。（実施例２）、（比較例２）に係るコロイドの物性を（表１）に示した。   5 g of 1% hydrochloric acid was added to 100 g of the obtained Pd—Pt colloidal solution (2), and after stirring for 1 hour, 1 g of 1% aqueous ammonia was added and further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particle cut was performed with a centrifuge (G = 8000). After measuring the concentration with ICP, the concentration was adjusted to 2.5% to obtain a Pd-Pt colloidal solution (2-2). This Pd—Pt colloidal solution (2-2) is referred to as (Example 2), and the Pd—Pt colloidal solution (2) is referred to as (Comparative Example 2). The physical properties of the colloid according to (Example 2) and (Comparative Example 2) are shown in (Table 1).

[合成例３]
Ｒｕ粒子分散液（Ｒｕコロイド溶液）の合成
塩化ルテニウム（ＩＩＩ）３水和物、２３．３ｇ（ルテニウム金属換算で９ｇ）を純水１６,０００ｇに溶解して得た金属塩水溶液に、錯化安定化剤として濃度５．０重量％のクエン酸３ナトリウム水溶液１,６６０ｇと還元剤として濃度０．１重量％の水素化ホウ素ナトリウム水溶液１４０ｇとを加え、窒素雰囲気下、２０℃で攪拌混合して、水にルテニウム微粒子が分散してなるルテニウムコロイド溶液を得た。ついで、ルテニウムコロイド溶液を限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて粗大不純物を除去し、濃縮し、ルテニウム金属換算で濃度２．５重量％のルテニウムコロイド溶液（３）とした。 [Synthesis Example 3]
Synthesis of Ru particle dispersion (Ru colloid solution)
In a metal salt aqueous solution obtained by dissolving 23.3 g (9 g in terms of ruthenium metal) of ruthenium (III) chloride trihydrate in 16,000 g of pure water, a concentration of 5.0% by weight is used as a complexing stabilizer. 1. 660 g of trisodium citrate aqueous solution and 140 g of sodium borohydride aqueous solution having a concentration of 0.1% by weight as a reducing agent are added and stirred and mixed at 20 ° C. in a nitrogen atmosphere to disperse ruthenium fine particles in water. A ruthenium colloid solution was obtained. Next, the ruthenium colloid solution was removed by using a ultrafilter (manufactured by ADVANTEC, Ultrafilter Q0500) to remove coarse impurities and concentrated to obtain a ruthenium colloid solution (3) having a concentration of 2.5% by weight in terms of ruthenium metal. .

この得られたＲｕコロイド溶液（３）、１００ｇに１％硝酸を５ｇ添加し、１時間攪拌後、１％アンモニア水を５ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、ＩＣＰで濃度測定後２.５％に濃度調整を行いＲｕコロイド溶液（３−２）を得た。このＲｕコロイド溶液（３−２）を（実施例３）とし、Ｒｕコロイド溶液（３）を（比較例３）とする。（実施例３）、（比較例３）に係るコロイドの物性を表−１に示した。   5 g of 1% nitric acid was added to 100 g of the obtained Ru colloid solution (3) and stirred for 1 hour, and then 5 g of 1% ammonia water was added and further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particles were cut with a centrifuge (G = 8000). After measuring the concentration with ICP, the concentration was adjusted to 2.5% to obtain a Ru colloid solution (3-2). This Ru colloid solution (3-2) is referred to as (Example 3), and the Ru colloid solution (3) is referred to as (Comparative Example 3). The physical properties of the colloid according to (Example 3) and (Comparative Example 3) are shown in Table 1.

[合成例４]
Ｒｈ粒子分散液（Ｒｈコロイド溶液）の合成
塩化ロジウム（ＩＩＩ）３水和物、２３．３ｇ（ロジウム金属換算で９ｇ）を純水１００ｇに溶解して得た金属塩水溶液に、錯化安定化剤として濃度５．０重量％のポリビニルピロリドン（関東化学製 Ｋ−３０ 分子量４００００）水溶液５０ｇと溶剤としてモノエチレングリコール９００ｇを加え、窒素雰囲気下、１００℃で６時間攪拌混合して、ロジウム微粒子が分散してなるロジウムコロイド溶液を得た。次いでロジウムコロイド溶液をロータリーエバポレーターで濃縮し、その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）１０ｇ入れ脱塩を行った。ロジウム金属換算で濃度２.５重量％のロジウムコロイド溶液（４）を得た。 [Synthesis Example 4]
Synthesis of Rh particle dispersion (Rh colloid solution)
Polyvinylpyrrolidone having a concentration of 5.0% by weight as a complexing stabilizer in a metal salt aqueous solution obtained by dissolving rhodium (III) chloride trihydrate, 23.3 g (9 g in terms of rhodium metal) in 100 g of pure water. (KANTO CHEMICAL K-30 molecular weight 40000) 50 g of an aqueous solution and 900 g of monoethylene glycol as a solvent were added and stirred and mixed at 100 ° C. for 6 hours in a nitrogen atmosphere to obtain a rhodium colloid solution in which rhodium fine particles were dispersed. Subsequently, the rhodium colloid solution was concentrated with a rotary evaporator, and then 10 g of an anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. A rhodium colloid solution (4) having a concentration of 2.5% by weight in terms of rhodium metal was obtained.

この得られたＲｈコロイド溶液（４）、１００ｇに１％酢酸を５ｇ添加し、１時間攪拌後、１％テトラメチルアンモニウム水を５ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、次いで限外濾器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて高分子成分を除去し、ＩＣＰで濃度測定後２.５％に濃度調整を行いＲｈコロイド溶液（４−２）を得た。このＲｈコロイド溶液（４−２）を（実施例４）とし、Ｒｈコロイド溶液（４）を（比較例４）とする。（実施例４）、（比較例４）に係るココロイドの物性を（表１）に示した。   5 g of 1% acetic acid was added to 100 g of the obtained Rh colloid solution (4) and stirred for 1 hour, and then 5 g of 1% tetramethylammonium water was added and further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particles are cut with a centrifuge (G = 8000), and then the polymer component is removed using an ultrafilter (ADVANTEC, Ultrafilter Q0500). After concentration measurement by ICP, 2.5% The Rh colloid solution (4-2) was obtained by adjusting the concentration. Let this Rh colloid solution (4-2) be (Example 4), and let Rh colloid solution (4) be (Comparative Example 4). The physical properties of the colloid according to (Example 4) and (Comparative Example 4) are shown in (Table 1).

[合成例５]
Ａｇ−Ｐｄ粒子分散液（Ａｇ−Ｐｄコロイド溶液）の合成
クエン酸水溶液（濃度３０質量％）２１９ｇに還元剤として硫酸第一鉄１２２ｇを溶解させた溶液を調製した。そして、この溶液３４１ｇを、硝酸銀水溶液（濃度１０質量％）８０ｇに室温で添加し、ついで硝酸パラジウム水溶液（濃度２０質量％）３９ｇに室温で添加し、充分に混合することによりＡｇ−Ｐｄ粒子の分散液を調製した。限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて粗大不純物を除去し、濃縮しＡｇ換算濃度２.５％のＡｇ−Ｐｄコロイド溶液（５）を得た。 [Synthesis Example 5]
Synthesis of Ag-Pd particle dispersion (Ag-Pd colloidal solution)
A solution was prepared by dissolving 122 g of ferrous sulfate as a reducing agent in 219 g of an aqueous citric acid solution (concentration: 30% by mass). Then, 341 g of this solution was added to 80 g of an aqueous silver nitrate solution (concentration: 10% by mass) at room temperature, and then added to 39 g of an aqueous palladium nitrate solution (concentration: 20% by mass) at room temperature. A dispersion was prepared. Coarse impurities were removed using an ultrafilter (manufactured by ADVANTEC, Ultrafilter Q0500) and concentrated to obtain an Ag-Pd colloidal solution (5) having an Ag equivalent concentration of 2.5%.

得られたＡｇ−Ｐｄコロイド溶液（５）１００ｇに１％塩酸を０.５ｇ添加し、１％テトラメチルアンモニウム水を５ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、ICPで濃度測定後２.５％に濃度調整を行いＡｇ−Ｐｄコロイド溶液（５−２）を得た。このＡｇ−Ｐｄコロイド溶液（５−２）を（実施例５）とし、Ａｇ−Ｐｄコロイド溶液（５）を（比較例５）とする。（実施例５）、（比較例５）に係るコロイドの物性を表−１に示した。   To 100 g of the obtained Ag—Pd colloidal solution (5), 0.5 g of 1% hydrochloric acid was added, 5 g of 1% tetramethylammonium water was added, and the mixture was further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particles were cut with a centrifuge (G = 8000). After measuring the concentration with ICP, the concentration was adjusted to 2.5% to obtain an Ag-Pd colloidal solution (5-2). This Ag-Pd colloidal solution (5-2) is referred to as (Example 5), and the Ag-Pd colloidal solution (5) is referred to as (Comparative Example 5). The physical properties of the colloid according to (Example 5) and (Comparative Example 5) are shown in Table 1.

[合成例６]
Ｐｔ−Ｒｈ粒子分散液（Ｐｔ−Ｒｈコロイド溶液）の合成
塩化ロジウム（ＩＩＩ）３水和物、２３．３ｇ（ロジウム金属換算で９ｇ）と塩化白金酸６水和物２５ｇ（白金金属換算で９ｇ）を純水１００ｇに溶解して得た金属塩水溶液に、錯化安定化剤として濃度５．０重量％のポリビニルピロリドン（関東化学製 Ｋ−３０ 分子量４００００）水溶液１００ｇと溶剤としてモノエチレングリコール１８００ｇを加え、窒素雰囲気下、１００℃で６時間攪拌混合して、白金−ロジウム複合微粒子が分散してなる白金−ロジウムコロイド溶液を得た。次いで白金−ロジウムコロイド溶液をロータリーエバポレーターで濃縮し、その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。金属換算で濃度２．５重量％のＰｔ−Ｒｈコロイド溶液（６）を得た。 [Synthesis Example 6]
Synthesis of Pt-Rh particle dispersion (Pt-Rh colloidal solution)
To a metal salt aqueous solution obtained by dissolving rhodium (III) chloride trihydrate, 23.3 g (9 g in terms of rhodium metal) and 25 g of chloroplatinic acid hexahydrate (9 g in terms of platinum metal) in 100 g of pure water. In addition, 100 g of a polyvinylpyrrolidone (K-30 molecular weight 40000) aqueous solution having a concentration of 5.0% by weight as a complexing stabilizer and 1800 g of monoethylene glycol as a solvent are added and stirred and mixed at 100 ° C. for 6 hours in a nitrogen atmosphere. Thus, a platinum-rhodium colloidal solution in which platinum-rhodium composite fine particles were dispersed was obtained. Subsequently, the platinum-rhodium colloid solution was concentrated by a rotary evaporator, and then 10 g of an anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. A Pt—Rh colloidal solution (6) having a concentration of 2.5% by weight in terms of metal was obtained.

この得られたＰｔ−Ｒｈコロイド溶液（６）、１００ｇに１％蟻酸を５ｇ添加し、１時間攪拌後、１％テトラメチルアンモニウム水を５ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、次いで限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて高分子成分を除去し、ＩＣＰで濃度測定後２.５％に濃度調整を行いＰｔ−Ｒｈコロイド溶液（６−２）を得た。このＰｔ−Ｒｈコロイド溶液（６−２）を（実施例６）とし、Ｐｔ−Ｒｈコロイド溶液（６）を（比較例６）とする。（実施例６）、（比較例６）に係るコロイドの物性を表−１に示した。   5 g of 1% formic acid was added to 100 g of the obtained Pt—Rh colloidal solution (6) and stirred for 1 hour, and then 5 g of 1% tetramethylammonium water was added and further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particle cut is performed with a centrifuge (G = 8000), then the polymer component is removed using an ultrafilter (ADVANTEC, Ultrafilter Q0500), and the concentration is measured by ICP to 2.5. % Was adjusted to obtain a Pt-Rh colloidal solution (6-2). This Pt—Rh colloidal solution (6-2) is referred to as (Example 6), and the Pt—Rh colloidal solution (6) is referred to as (Comparative Example 6). The physical properties of the colloid according to (Example 6) and (Comparative Example 6) are shown in Table 1.

[合成例７]
Ｐｄ−Ａｕ粒子分散液（Ｐｄ−Ａｕコロイド溶液）の合成
硝酸パラジウム（ＩＩ）水和物２２．５ｇ（パラジウム金属換算で９ｇ）と塩化金(ＩＩＩ)酸４水和物１８．８ｇ（金金属換算で９ｇ）をそれぞれ純水１００ｇに溶解して得た金属塩水溶液に、錯化安定化剤として濃度５．０重量％のポリビニルピロリドン（関東化学製 Ｋ−３０ 分子量４００００）水溶液をそれぞれ５０ｇずつ混合した。溶剤としてモノエチレングリコール１８００ｇ中に加え、窒素雰囲気下、１００℃で６時間攪拌混合して、パラジウム−金複合微粒子が分散してなるパラジウム−金コロイド溶液を得た。次いでパラジウム−金コロイド溶液をロータリーエバポレーターで濃縮し、その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。パラジウム−金金属換算で濃度３．０重量％のパラジウム−金コロイド溶液（７）を得た。 [Synthesis Example 7]
Synthesis of Pd-Au particle dispersion (Pd-Au colloidal solution)
It was obtained by dissolving 22.5 g of palladium (II) nitrate hydrate (9 g in terms of palladium metal) and 18.8 g of gold chloride (III) acid tetrahydrate (9 g in terms of gold metal) in 100 g of pure water. 50 g of an aqueous solution of polyvinylpyrrolidone (K-30 molecular weight 40000, manufactured by Kanto Chemical Co., Inc.) having a concentration of 5.0% by weight was mixed with the metal salt aqueous solution as a complexing stabilizer. In addition to 1800 g of monoethylene glycol as a solvent, the mixture was stirred and mixed at 100 ° C. for 6 hours under a nitrogen atmosphere to obtain a palladium-gold colloid solution in which palladium-gold composite fine particles were dispersed. Next, the palladium-gold colloid solution was concentrated with a rotary evaporator, and then 10 g of an anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. A palladium-gold colloid solution (7) having a concentration of 3.0% by weight in terms of palladium-gold metal was obtained.

得られた白金−ロジウムコロイド溶液の粒子径は、走査型電子顕微鏡（株式会社日立製作所製、Ｓ−５５００）で測定したところ平均粒子径は２nmであった。この得られたＰｄ−Ａｕコロイド溶液（７）１００ｇに１％蟻酸５ｇを添加し、１時間攪拌後、１％テトラメチルアンモニウム水を５ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、次いで限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて高分子成分を除去し、ＩＣＰで濃度測定後２.５％に濃度調整を行いＰｄ−Ａｕコロイド溶液（７−２）を得た。このＰｄ−Ａｕコロイド溶液（７−２）を（実施例７）とし、Ｐｄ−Ａｕコロイド溶液（７）を（比較例７）とする。（実施例７）、（比較例７）に係るコロイドの物性を（表１）に示した。   The particle diameter of the obtained platinum-rhodium colloidal solution was measured with a scanning electron microscope (manufactured by Hitachi, Ltd., S-5500), and the average particle diameter was 2 nm. To 100 g of the obtained Pd—Au colloid solution (7), 5 g of 1% formic acid was added and stirred for 1 hour, and then 5 g of 1% tetramethylammonium water was added and further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particle cut is performed with a centrifuge (G = 8000), then the polymer component is removed using an ultrafilter (ADVANTEC, Ultrafilter Q0500), and the concentration is measured by ICP to 2.5. % Was adjusted to obtain a Pd—Au colloid solution (7-2). This Pd—Au colloid solution (7-2) is referred to as (Example 7), and the Pd—Au colloid solution (7) is referred to as (Comparative Example 7). The physical properties of the colloid according to (Example 7) and (Comparative Example 7) are shown in (Table 1).

[合成例８]
Ｐｄ−Ｃｕ粒子分散液（Ｐｄ−Ｃｕコロイド溶液）の合成
クエン酸水溶液（濃度３０質量％）２１９ｇに還元剤として硫酸第一鉄１２２ｇを溶解させた溶液を調製した。そして、この溶液３４１ｇを、硝酸パラジウム水溶液（濃度２０質量％）３９ｇに室温で添加し、次いで硝酸銅水溶液（濃度２０％）を１０ｇ充分に混合することによりＰｄ粒子の分散液を調製した。限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて粗大不純物を除去し、濃縮しＰｄ−Ｃｕ換算濃度３％のＰｄ−Ｃｕコロイド溶液（８）を得た。 [Synthesis Example 8]
Synthesis of Pd-Cu particle dispersion (Pd-Cu colloid solution)
A solution was prepared by dissolving 122 g of ferrous sulfate as a reducing agent in 219 g of an aqueous citric acid solution (concentration: 30% by mass). Then, 341 g of this solution was added to 39 g of an aqueous palladium nitrate solution (concentration 20% by mass) at room temperature, and then 10 g of an aqueous copper nitrate solution (concentration 20%) was sufficiently mixed to prepare a dispersion of Pd particles. Coarse impurities were removed using an ultrafilter (manufactured by ADVANTEC, Ultrafilter Q0500) and concentrated to obtain a Pd—Cu colloid solution (8) having a Pd—Cu equivalent concentration of 3%.

この得られたＰｄ−Ｃｕコロイド溶液（７）、１００ｇに１％塩酸を０.１ｇ添加し、１時間攪拌後、１％テトラメチルアンモニウム水を５ｇ添加しさらに１時間攪拌した。陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、ＩＣＰで濃度測定後２.５％に濃度調整を行いＰｄ−Ｃｕコロイド溶液（８−２）を得た。このＰｄ−Ｃｕコロイド溶液（８−２）を（実施例８）とし、Ｐｄコロイド溶液（８）を（比較例８）とする。（実施例８）、（比較例８）に係るコロイドの物性を（表１）に示した。   To 100 g of this obtained Pd—Cu colloid solution (7), 0.1 g of 1% hydrochloric acid was added and stirred for 1 hour, and then 5 g of 1% tetramethylammonium water was added and further stirred for 1 hour. Desalination was carried out by adding 10 g of an anion exchange resin (Mitsubishi Chemical SANUPC). After desalting, coarse particle cut was performed with a centrifuge (G = 8000). After measuring the concentration with ICP, the concentration was adjusted to 2.5% to obtain a Pd—Cu colloid solution (8-2). This Pd—Cu colloidal solution (8-2) is referred to as (Example 8), and the Pd colloidal solution (8) is referred to as (Comparative Example 8). The physical properties of the colloid according to (Example 8) and (Comparative Example 8) are shown in (Table 1).

[合成例９]
Ａｇ粒子分散液（Ａｇコロイド溶液）の合成
クエン酸水溶液（濃度３０質量％）２１９ｇに還元剤として硫酸第一鉄１２２ｇを溶解させた溶液を調製した。そして、この溶液３４１ｇを、硝酸銀水溶液（濃度１０質量％）１６０ｇに室温で添加し、充分に混合することによりＡｇ粒子の分散液を調製した。限外濾過器（ＡＤＶＡＮＴＥＣ社製、ウルトラフィルターＱ０５００）を用いて粗大不純物を除去し、濃縮しＡｇ換算濃度３％のＡｇコロイド溶液（９）を得た。 [Synthesis Example 9]
Synthesis of Ag particle dispersion (Ag colloid solution)
A solution was prepared by dissolving 122 g of ferrous sulfate as a reducing agent in 219 g of an aqueous citric acid solution (concentration: 30% by mass). Then, 341 g of this solution was added to 160 g of an aqueous silver nitrate solution (concentration: 10% by mass) at room temperature, and thoroughly mixed to prepare a dispersion of Ag particles. Coarse impurities were removed using an ultrafilter (manufactured by ADVANTEC, Ultrafilter Q0500) and concentrated to obtain an Ag colloid solution (9) having an Ag equivalent concentration of 3%.

得られたＡｇ−Ｐｄコロイド溶液（５）１００ｇに１％蟻酸を０.５ｇ添加し、１％テトラメチルアンモニウム水を５ｇ添加しさらに１時間攪拌した。その後陰イオン交換樹脂（三菱化学ＳＡＮＵＰＣ）を１０ｇ入れて脱塩を行った。脱塩後粗大粒子カットを遠心分離機（Ｇ＝８０００）で行い、ＩＣＰで濃度測定後２.５％に濃度調整を行いＡｇコロイド溶液（９−２）を得た。このＰｄコロイド溶液（９−２）を（実施例９）とし、Ｐｄコロイド溶液（９）を（比較例９）とする。（実施例９）、（比較例９）に係るコロイドの物性を（表１）に示した。   To 100 g of the obtained Ag—Pd colloidal solution (5), 0.5 g of 1% formic acid was added, 5 g of 1% tetramethylammonium water was added, and the mixture was further stirred for 1 hour. Thereafter, 10 g of anion exchange resin (Mitsubishi Chemical SANUPC) was added for desalting. After desalting, coarse particle cut was performed with a centrifuge (G = 8000). After concentration measurement with ICP, the concentration was adjusted to 2.5% to obtain an Ag colloid solution (9-2). This Pd colloid solution (9-2) is referred to as (Example 9), and the Pd colloid solution (9) is referred to as (Comparative Example 9). The physical properties of the colloid according to (Example 9) and (Comparative Example 9) are shown in (Table 1).

[合成例１０]（比較例用 特開２００２−２９４３０１に相当）
Ａｇ−Ｐｄ粒子分散液（Ａｇ−Ｐｄコロイド溶液）の合成
純水１００ｇに、硝酸銀水溶液６．１２ｇおよびクエン酸鉄水溶液０．１ｇを添加して混合金属塩水溶液を調製した。ついで、この混合金属塩水溶液に安定化剤として濃度３０重量％のクエン酸３ナトリウム２００ｇを加え、ついで還元剤として濃度２５重量％の硫酸第１鉄水溶液７６．５ｇを加え、窒素雰囲気下で２０時間撹拌して、金属微粒子の分散液を調製した。得られた分散液から金属微粒子を遠心分離機により分離回収し、濃度１重量％の塩酸水溶液で洗浄した後純水に分散させ、金属換算で濃度が２.５重量％の金属微粒子の水分散液を調製した。ついで、金属微粒子の水分散液をナノマイザーシステムで処理して金属微粒子の水単分散液を調製し、３．０重量％に調製してＡｇコロイド溶液（１０）を得た。このＡｇコロイド溶液（１０）を（比較例１０）とし、その物性を（表１）に示す。 [Synthesis Example 10] (corresponding to Comparative Example JP-A-2002-294301)
Synthesis of Ag-Pd particle dispersion (Ag-Pd colloidal solution)
A mixed metal salt aqueous solution was prepared by adding 6.12 g of a silver nitrate aqueous solution and 0.1 g of an iron citrate aqueous solution to 100 g of pure water. Next, 200 g of trisodium citrate having a concentration of 30% by weight as a stabilizer was added to the mixed metal salt aqueous solution, and then 76.5 g of an aqueous ferrous sulfate solution having a concentration of 25% by weight was added as a reducing agent. By stirring for a time, a dispersion of fine metal particles was prepared. Metal fine particles are separated and collected from the obtained dispersion by a centrifugal separator, washed with a 1% by weight hydrochloric acid aqueous solution and then dispersed in pure water, and the metal fine particles having a concentration of 2.5% by weight in water are dispersed in water. A liquid was prepared. Next, an aqueous dispersion of metal fine particles was treated with a nanomizer system to prepare an aqueous monodispersion of metal fine particles. The concentration was adjusted to 3.0% by weight to obtain an Ag colloid solution (10). This Ag colloid solution (10) is referred to as (Comparative Example 10), and the physical properties thereof are shown in (Table 1).

透明導電性被膜形成用塗布液の調製
（実施例１〜９）、（比較例１〜１０）に係る調製直後の金属微粒子分散液と、この金属微粒子分散液を７０℃の保管条件にて３０日間保管したものと、をエタノール、１−エトキシ−２−プロパノール、ジアセトンアルコール（５：４：１重量混合比）の混合溶媒とを混合して、各々の金属微粒子分散液から透明導電性被膜形成用塗布液を調製した。各例に係る透明導電性被膜形成用塗布液に含まれる金属微粒子の濃度を（表１）に示す。 Preparation of coating liquid for forming transparent conductive film (Examples 1 to 9), metal fine particle dispersion immediately after preparation according to (Comparative Examples 1 to 10), and this metal fine particle dispersion under 30 ° C. storage conditions. What was stored for a day is mixed with a mixed solvent of ethanol, 1-ethoxy-2-propanol, diacetone alcohol (5: 4: 1 weight mixing ratio), and transparent conductive film is formed from each metal fine particle dispersion. A forming coating solution was prepared. Table 1 shows the concentration of the metal fine particles contained in the coating liquid for forming a transparent conductive film according to each example.

透明被膜形成用塗布液の調製
正珪酸エチル（ＳiＯ２：２８重量％）５０ｇ、エタノール１９４.６ｇ、濃硝酸１.４ｇおよび純水３４ｇの混合溶液を室温で５時間攪拌してＳiＯ２濃度５重量％のマトリックス形成成分を含む液を調製した。これに、エタノール／ブタノール／ジアセトンアルコール／イソプロパノール（２：１：１：５重量混合比）の混合溶媒を加え、１.３重量％の透明被膜形成用塗布液を調製した。 Preparation of coating solution for forming transparent film A mixed solution of 50 g of normal ethyl silicate (SiO 2 : 28% by weight), 194.6 g of ethanol, 1.4 g of concentrated nitric acid and 34 g of pure water was stirred at room temperature for 5 hours to obtain a SiO 2 concentration of 5 A liquid containing a weight percent matrix-forming component was prepared. To this was added a mixed solvent of ethanol / butanol / diacetone alcohol / isopropanol (2: 1: 1: 5 weight mixing ratio) to prepare a coating solution for forming a transparent film of 1.3% by weight.

透明導電性被膜付基材の製造
１００mm角ガラスの表面を４０℃で保持しながら、スピナー法で１５０ｒｐｍ、９０秒の条件で透明導電性被膜形成用塗布液を塗布し乾燥した。次いで、このようにして形成された透明導電性被膜上に、同じように、スピナー法でボトム反射の波長が５５０ｎｍになる条件の回転数１００〜３００ｒｐｍ、９０秒の条件で透明被膜形成用塗布液を塗布・乾燥し、１６０℃で３０分間焼成して透明導電性被膜付基材を得た。そしてこれらの透明導電性被膜付基材の膜特性を確認した。その結果を（表２）に示す。 Production of Substrate with Transparent Conductive Film A transparent conductive film-forming coating solution was applied and dried by a spinner method at 150 rpm for 90 seconds while maintaining the surface of 100 mm square glass at 40 ° C. Next, on the transparent conductive film thus formed, similarly, a coating liquid for forming a transparent film under the condition of a rotation speed of 100 to 300 rpm and a condition of 90 seconds under the condition that the bottom reflection wavelength is 550 nm by the spinner method. Was applied and dried, and baked at 160 ° C. for 30 minutes to obtain a substrate with a transparent conductive film. And the film | membrane characteristic of these base materials with a transparent conductive film was confirmed. The results are shown in (Table 2).

Figure 0005580153
Figure 0005580153

Figure 0005580153
Figure 0005580153

（表１）に示すように、酸処理及びアルカリ処理、並びにイオン交換樹脂による脱塩を行っている（実施例−１〜９）に係る金属微粒子分散液では、金属微粒子に対する不純物量は０．０２〜０．１重量％であった。これに対してこれらの処理を行っていない（比較例−１〜１０）では不純物量が０．４〜０．８重量％であり、各実施例の４〜４０倍の不純物が含まれている。   As shown in Table 1, in the metal fine particle dispersions according to (Examples 1 to 9) where acid treatment and alkali treatment and desalting with an ion exchange resin are performed, the amount of impurities with respect to the metal fine particles is 0.00. It was 02 to 0.1% by weight. On the other hand, when these treatments are not performed (Comparative Examples 1 to 10), the amount of impurities is 0.4 to 0.8% by weight, and contains 4 to 40 times as many impurities as in each Example. .

そしてこれら酸処理、アルカリ処理や脱塩が行われ、不純物の含有量が低減されたことにより、（実施例-１〜９）の金属微粒子分散液の表面電荷量は５．８〜２５（μｅｑ／ｇ）となり、本発明の規格０．５〜４５（μｅｑ／ｇ）の範囲内の値となった。また伝導度についても４〜１３（μＳ／ｍ）となって、本発明の規格１〜１５（μＳ／ｍ）の範囲内の値となった。そして表面電荷量、伝導度がこれらの範囲内の値となっていることにより、７０℃の条件で保管した３０日後の二次粒子径の変化率が０．４〜１．２倍の範囲内（規格：１．５倍以内）となり、長期間良好な分散状態が維持される触媒微粒子分散液であることが確認できた。   These acid treatment, alkali treatment and desalting were performed, and the content of impurities was reduced, so that the surface charge amount of the metal fine particle dispersions of (Example-1 to 9) was 5.8 to 25 (μeq). / G), which is a value within the range of 0.5 to 45 (μeq / g) of the present invention. Further, the conductivity was 4 to 13 (μS / m), which was within the range of the standard 1 to 15 (μS / m) of the present invention. And since the amount of surface charge and conductivity are values within these ranges, the change rate of the secondary particle diameter after 30 days of storage at 70 ° C. is within the range of 0.4 to 1.2 times. (Standard: within 1.5 times), and it was confirmed that the catalyst fine particle dispersion was maintained in a good dispersion state for a long time.

これに対して酸、アルカリによる処理及び脱塩を行っていない（比較例-１〜１０）では、表面電荷、伝導度共に本発明の規格を超えており、その結果、７０℃の温度条件下で３０日保管した後の二次粒子径の変化率が１．９〜１３．１倍となり、実施例に比べて不安定な金属微粒子分散液となっている。   On the other hand, in the case where the treatment with acid and alkali and the desalting were not performed (Comparative Examples-1 to 10), both the surface charge and the conductivity exceeded the standard of the present invention. The change rate of the secondary particle diameter after storage for 30 days is 1.9 to 13.1 times, which is an unstable metal fine particle dispersion compared to the examples.

また発明者らは、酸処理の際に塩酸を用いたり、原料の金属塩中に含まれたりしている場合のＣｌ成分（塩素原子）が金属微粒子表面に吸着することによっても金属微粒子の酸化を抑制することができるのではないかと考えている。Ｃｌ成分は洗浄やイオン交換でも低減できないことから、酸処理の際に塩酸を選択することなどによって金属微粒子の酸化の抑制効果を高めることができる可能性がある。金属微粒子分散液中のＣｌ成分の含有量は、金属微粒子に対して０．５〜３重量％程度が好ましい。   The inventors also oxidize metal fine particles by adsorbing Cl components (chlorine atoms) on the surface of the metal fine particles when hydrochloric acid is used in the acid treatment or contained in the metal salt of the raw material. I think that it can be suppressed. Since the Cl component cannot be reduced even by washing or ion exchange, the effect of suppressing oxidation of the metal fine particles may be enhanced by selecting hydrochloric acid during the acid treatment. The content of the Cl component in the metal fine particle dispersion is preferably about 0.5 to 3% by weight with respect to the metal fine particles.

次に酸化物の形成量について（表１）を見ると、１０５℃真空乾燥品、２００℃大気乾燥品のいずれにおいても、酸、アルカリ処理を行った（実施例-１〜９）の酸化物量は、金属微粒子の６〜３０重量％の範囲に収まっている（規格：０．１〜３０重量％）。そして１０５℃真空乾燥品と２００℃大気乾燥品との間の酸化物量の差も１〜５重量％程度であり、高温、含酸素雰囲気中でも酸化されにくい金属微粒子であるといえる。   Next, when looking at the amount of oxide formed (Table 1), the amount of oxide obtained by performing acid treatment and alkali treatment (Examples 1 to 9) in both the 105 ° C. vacuum-dried product and the 200 ° C. air-dried product. Is within the range of 6 to 30% by weight of the metal fine particles (standard: 0.1 to 30% by weight). The difference in the amount of oxide between the 105 ° C. vacuum-dried product and the 200 ° C. air-dried product is about 1 to 5% by weight, which can be said to be metal fine particles that are not easily oxidized even in a high temperature and oxygen-containing atmosphere.

一方で、酸、アルカリ処理を行っていない（比較例-１〜１０）（但し、比較例１０では酸処理のみ実施）では、酸化物量が規格の範囲を超え、３２〜９５重量％となった。また、１０５℃真空乾燥品と２００℃大気乾燥品とでは、酸化物量が１０〜３３重量％異なり、各実施例に比べて酸化されやすい金属微粒子であることが分かる。   On the other hand, in the case where no acid or alkali treatment was carried out (Comparative Examples-1 to 10) (however, only the acid treatment was carried out in Comparative Example 10), the oxide amount exceeded the standard range and became 32 to 95% by weight. . In addition, it can be seen that the 105 ° C. vacuum-dried product and the 200 ° C. air-dried product differ in the amount of oxide by 10 to 33 wt.

ついで各実施例、比較例に係る金属微粒子分散液から透明導電性被膜形成用塗布液を調製し、当該塗布液にて透明導電性被膜付基材を製造したときの膜特性の評価について（表２）を参照しながら検討する。
（表２）に示した（実施例-１〜９）に係る膜特性の評価結果によれば、製造直後の金属微粒子分散液を使用したもの（製造直後品）と、７０℃の温度条件下で３０日保管した後の金属微粒子分散液を使用したもの（３０日保管品）との間で表面抵抗値、透過率、ヘーズ、反射率、ボトム波長の各特性について、各特性値が２倍を超えて変化するといった大きな特性の変化は見られなかった。また、耐過酸化水素性、耐塩酸性についても（実施例-１〜８）の評価結果が「○」で、（実施例９）のみが「△」であった。 Subsequently, a coating liquid for forming a transparent conductive film was prepared from the metal fine particle dispersions according to each Example and Comparative Example, and evaluation of film characteristics when a substrate with a transparent conductive film was produced with the coating liquid (Table) Study with reference to 2).
According to the evaluation results of the film characteristics according to (Example-1 to 9) shown in (Table 2), those using the metal fine particle dispersion immediately after production (immediately after production) and the temperature condition of 70 ° C. Each characteristic value is doubled for each of the surface resistance, transmittance, haze, reflectance, and bottom wavelength characteristics with the one using the metal fine particle dispersion after 30 days storage (30 day storage product) There was no significant change in properties, such as changing beyond the range. In addition, regarding the hydrogen peroxide resistance and hydrochloric acid resistance, the evaluation results of (Example-1 to 8) were “◯” and only (Example 9) was “Δ”.

これに対して（比較例-１〜１０）の場合には、（比較例-１〜７、９〜１０）の９例において、３０日保管品の表面抵抗値が製造直後品の２．１〜１９００倍まで上昇し、ヘーズの値についても４〜１９倍まで上昇している。そして表面抵抗値については（実施例-１〜９）が１６〜８３００（Ω／□）であるに対し、（比較例-１〜１０）では３５〜１９０００（Ω／□）と、その絶対値も相対的に高くなっている。   On the other hand, in the case of (Comparative Examples-1 to 10), the surface resistance value of the 30-day storage product is 2.1 of the product immediately after production in 9 cases of (Comparative Examples-1 to 7, 9-10). It has increased to ˜1900 times, and the haze value has also increased to 4 to 19 times. As for the surface resistance value, (Examples-1 to 9) are 16 to 8300 (Ω / □), while (Comparative Examples-1 to 10) are 35 to 19000 (Ω / □), and their absolute values. Is also relatively high.

これらの結果について、表面抵抗値やヘーズの値には金属微粒子分散液の表面電荷量や電気伝導度、二次粒子径などが影響を与えることが分かっており、表面電荷量や電気伝導度が低い各実施例では、比較例に比べて相対的に表面抵抗値が低い膜特性が得られている。そして各実施例に係る金属微粒子分散液は、生産直後品と３０日保管品との間で二次粒子径の変化率が小さいことから、膜特性においても表面抵抗値やヘーズの変化が小さく、ポットライフの長い金属微粒子分散液であると評価できる。   Regarding these results, it is known that the surface charge amount, electrical conductivity, secondary particle diameter, etc. of the metal fine particle dispersion affect the surface resistance value and haze value. In each of the low examples, film characteristics having a relatively low surface resistance value as compared with the comparative example are obtained. And, since the change rate of the secondary particle diameter is small between the product immediately after production and the 30-day storage product, the metal particle dispersion according to each example has a small change in surface resistance value and haze in the film characteristics, It can be evaluated as a metal fine particle dispersion having a long pot life.

Claims (9)

金属微粒子と、分散媒とを含む金属微粒子分散液において、
前記金属微粒子は、Ａｇ、Ｐｄ、Ｃｕ、Ｒｕ、Ｒｈ、ＰｔおよびＡｕからなる金属群より選ばれる少なくとも１種以上の金属を含み、その一次粒子径が１〜３０ｎｍの範囲であり、二次粒子径が５〜１００ｎｍの範囲であり、当該金属微粒子の０．１〜３０重量％が酸化されていることと、
金属微粒子濃度が０．５重量％のときの表面電荷量が０．５〜４５μｅｑ／ｇの範囲であり、電気伝導度が１〜１５μＳ／ｃｍの範囲であることと、を備えたことを特徴とする金属微粒子分散液。 In a metal fine particle dispersion containing metal fine particles and a dispersion medium,
The metal fine particles include at least one metal selected from the metal group consisting of Ag, Pd, Cu, Ru, Rh, Pt and Au, the primary particle diameter is in the range of 1 to 30 nm, and the secondary particles The diameter is in the range of 5 to 100 nm, 0.1 to 30% by weight of the metal fine particles are oxidized,
The surface charge amount when the metal fine particle concentration is 0.5% by weight is in the range of 0.5 to 45 μeq / g, and the electric conductivity is in the range of 1 to 15 μS / cm. Metal fine particle dispersion. 前記金属微粒子が、前記金属群に含まれる単独の金属、またはＰｄ−Ａｇ、Ｐｄ−Ｐｔ、Ｐｄ−Ｃｕ、Ａｇ−Ｃｕ、Ｐｄ−Ａｕ、Ｐｔ−Ｒｈ、Ｐｄ−Ｐｔ−Ｒｈ、Ｐｄ−Ｒｈであることを特徴とする請求項１に記載の金属微粒子分散液。   The metal fine particle is a single metal included in the metal group, or Pd-Ag, Pd-Pt, Pd-Cu, Ag-Cu, Pd-Au, Pt-Rh, Pd-Pt-Rh, Pd-Rh. The metal fine particle dispersion according to claim 1, wherein ７０℃の保管条件下で、前記金属微粒子分散液を調製してから３０日間経過するまでの二次粒子径の変化率が１．５倍以内であることを特徴とする請求項１または２に記載の金属微粒子分散液。   3. The change rate of the secondary particle diameter from the preparation of the metal fine particle dispersion to the elapse of 30 days under a storage condition of 70 ° C. is within 1.5 times. The metal fine particle dispersion described. 前記金属微粒子濃度が０．５重量％のときのｐＨが２〜１１の範囲であることを特徴とする請求項１ないし３のいずれか一つに記載の金属微粒子分散液。   The metal fine particle dispersion according to any one of claims 1 to 3, wherein the pH when the metal fine particle concentration is 0.5 wt% is in the range of 2 to 11. Ｃｌ成分の含有量が金属微粒子に対して０．５〜３重量％の範囲であることを特徴とする、請求項１ないし４のいずれか一つに記載の金属微粒子分散液。   The metal fine particle dispersion according to any one of claims 1 to 4, wherein the Cl component content is in the range of 0.5 to 3 wt% with respect to the metal fine particles. 前記分散媒は、水、クエン酸水溶液、モノエチレングリコールからなる分散媒群から選ばれることを特徴とする請求項１ないし５のいずれか一つに記載の金属微粒子分散液。   The metal fine particle dispersion according to any one of claims 1 to 5, wherein the dispersion medium is selected from a group of dispersion media consisting of water, an aqueous citric acid solution, and monoethylene glycol. 請求項１ないし６のいずれか一つに記載の金属微粒子分散液と極性溶媒とを含むことを特徴とする透明導電性被膜形成用塗布液。   A coating liquid for forming a transparent conductive film, comprising the metal fine particle dispersion according to any one of claims 1 to 6 and a polar solvent. さらにバインダー成分を含むことを特徴とする請求項７に記載の透明導電性被膜形成用塗布液。 Furthermore, the binder component is included, The coating liquid for transparent conductive film formation of Claim 7 characterized by the above-mentioned. 基材と、基材上の透明導電性微粒子層のみ若しくは、該透明導電性微粒子層上に設けられ、該透明導電性微粒子層よりも屈折率が低い透明被膜とからなる透明導電性被膜付基材において、前記透明導電性微粒子層が請求項７または８に記載の透明導電性被膜形成用塗布液から形成されたものであることを特徴とする透明導電性被膜付基材。 A transparent conductive film-coated base comprising a base material and a transparent conductive fine particle layer only on the base material or a transparent film having a refractive index lower than that of the transparent conductive fine particle layer provided on the transparent conductive fine particle layer A substrate with a transparent conductive film, wherein the transparent conductive fine particle layer is formed from the transparent conductive film-forming coating solution according to claim 7 or 8 .
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