JP5868284B2 - Electromagnetic wave shielding composition, method for producing the same, and method for forming electromagnetic wave shielding material using the composition - Google Patents

Description

本発明は、優れた導電性を有することで電磁波遮蔽効果を発現する電磁波遮蔽用組成物とその製造方法及び該組成物を用いた電磁波遮蔽物の形成方法に関する。 The present invention relates to an electromagnetic wave shielding composition that exhibits an electromagnetic wave shielding effect by having excellent conductivity, a method for producing the same, and an electromagnetic wave shielding material forming method using the composition.

ＰＤＰ（Plasma Display Panel）やＣＲＴ（Cathode Ray Tube）などのディスプレイ前面からは、電磁波が発生している。この電磁波を遮蔽するために、透明性と電磁波遮蔽性を兼ね備えた遮蔽材が使用され、現在までに以下のような遮蔽材やその製造方法が提案されている。   Electromagnetic waves are generated from the front surface of a display such as a plasma display panel (PDP) or a cathode ray tube (CRT). In order to shield this electromagnetic wave, a shielding material having both transparency and electromagnetic shielding properties is used, and the following shielding materials and manufacturing methods thereof have been proposed so far.

先ず、高透磁率非晶合金層を少なくとも一層有する良導電性繊維からなることを特徴とする電磁波シールド材が提案されている。（例えば、特許文献１参照。）。上記特許文献１では、ＣＲＴやプラズマ、ＥＬ等のディスプレイより発生する電磁波のシールドとして、電磁波シールド材を用いて導電性メッシュを形成し、フィルターとして用いたり、導電性メッシュを透明樹脂板に埋め込むなどの方法が記載されている。また、ポリマー性繊維の織物類とシート材料類で熱成形の工程中で多孔質になり得る性質のある担体材料を含み、この担体材料は１枚又はそれ以上の金属マットをその中に少なくとも部分的に埋め込まれた状態で含み、このマットは多数の細くて不規則に配向した金属繊維からなる熱成形性電磁波干渉シールディングシートが提案されている（例えば、特許文献２参照。）。上記特許文献２では、担体材料中に金属マットを少なくとも部分的に埋め込む方法としては、例えば、不織ウエブ状の担体材料と金属繊維のマットの結合に、担体材料を加熱して軟化させたものにマットを重ね合わせて、担体材料の中に埋め込んで作る方法や、機械的な圧力をかける方法、その両方を用いる方法などが記載されている。   First, an electromagnetic wave shielding material characterized by comprising a highly conductive fiber having at least one high permeability amorphous alloy layer has been proposed. (For example, refer to Patent Document 1). In Patent Document 1, a conductive mesh is formed using an electromagnetic shielding material as a shield for electromagnetic waves generated from displays such as CRT, plasma, EL, etc., and used as a filter, or the conductive mesh is embedded in a transparent resin plate. The method is described. Also included are polymeric fiber fabrics and sheet materials that include a carrier material that can be made porous during the thermoforming process, the carrier material comprising at least a portion of one or more metal mats therein. A thermoformable electromagnetic interference shielding sheet composed of a large number of thin and irregularly oriented metal fibers has been proposed (see, for example, Patent Document 2). In the above Patent Document 2, as a method of at least partially embedding a metal mat in a carrier material, for example, the carrier material is heated and softened to bond the nonwoven web-like carrier material and the metal fiber mat. A method of superimposing mats and embedding them in a carrier material, a method of applying mechanical pressure, and a method of using both are described.

また、透光性基板上に透明アンカー層を形成し、その上に銅などの無電解めっき層がパターン状に形成され、その表面に透光性基板の屈折率より低い屈折率を有する化合物からなる透明薄膜層が形成された透光性電磁波シールド材料が提案されている（例えば、特許文献３参照。）。この特許文献３では、無電解めっき層が電磁波シールドの役目をしている。   In addition, a transparent anchor layer is formed on a translucent substrate, an electroless plating layer such as copper is formed in a pattern thereon, and a compound having a refractive index lower than that of the translucent substrate on the surface thereof. A translucent electromagnetic shielding material in which a transparent thin film layer is formed has been proposed (see, for example, Patent Document 3). In Patent Document 3, the electroless plating layer serves as an electromagnetic wave shield.

また、塗料用合成樹脂又は接着用合成樹脂に導電性粉末を均一に混合して得た電磁波シールド塗料を透明なフィルム又は板状物に格子状もしくは縞状に印刷した透光性電磁波シールド材が提案されている（例えば、特許文献４参照。）。また、透明基板表面上に塗料用樹脂中に導電性粉末を混練してなる導電性塗料を網目状に印刷し、真空中で焼き付けてなることを特徴とする透明電磁波シールド板の製造方法が提案されている（例えば、特許文献５参照。）。   Also, there is a translucent electromagnetic shielding material obtained by printing an electromagnetic shielding coating obtained by uniformly mixing conductive powder with a synthetic resin for coating or an adhesive synthetic resin on a transparent film or plate in a grid or stripe pattern. It has been proposed (see, for example, Patent Document 4). Also proposed is a method for producing a transparent electromagnetic wave shielding plate, characterized in that a conductive coating material obtained by kneading conductive powder in a coating resin on a transparent substrate surface is printed in a mesh and baked in a vacuum. (For example, refer to Patent Document 5).

また、加熱又は加圧により流動する接着剤層を有する導電性金属付きプラスチックフィルムの導電性金属がフォトリソグラフ法などのマイクロリソグラフ法により幾何学図形を有し、その開口率が５０％以上である電磁波シールド性接着フィルム及び電磁波遮蔽構造体が提案されている（例えば、特許文献６参照。）。上記特許文献６では、幾何学図形を形成させる方法として、レジストフィルム貼り付け、露光、現像、ケミカルエッチング、レジストフィルム剥離といったケミカルエッチング法を使用したフォトリソグラフ工程により形成している。   In addition, the conductive metal of the plastic film with conductive metal having an adhesive layer that flows by heating or pressurization has a geometric figure by a microlithographic method such as a photolithographic method, and the aperture ratio is 50% or more. An electromagnetic shielding adhesive film and an electromagnetic shielding structure have been proposed (see, for example, Patent Document 6). In the above-mentioned patent document 6, as a method of forming a geometrical figure, it is formed by a photolithographic process using a chemical etching method such as resist film sticking, exposure, development, chemical etching, and resist film peeling.

更に、金属箔の一方の面に保護層を設ける工程と、金属箔の他の面にフォトレジスト法により所定のメッシュパターンを現像する工程と、レジストの未現像部を除去し、その除去部分の金属箔をエッチングする工程と、現像部であるレジストを除去する工程とを備える金属性メッシュの製造方法が提案されている（例えば、特許文献７参照。）。上記特許文献７では、先ず、金属箔の一方の面に透明性ベースフィルムを粘着剤で貼り合わせ、金属箔の他方の面にレジストをラミネートし、このレジストに所定のメッシュパターンを有するマスクを積層した後、マスク上から紫外線を照射して、光透過部に対応する部分のレジストを露光し現像レジスト部を形成する。次に、マスク及びレジストの未現像部を除去し、その除去した未現像部に対応する部分の金属箔をエッチングした後、金属箔上の現像レジスト部を除去することにより樹脂フィルムと金属箔メッシュからなる電磁波シールド材を製造していた。   Furthermore, a step of providing a protective layer on one side of the metal foil, a step of developing a predetermined mesh pattern by a photoresist method on the other side of the metal foil, and removing the undeveloped portion of the resist, There has been proposed a method for producing a metallic mesh comprising a step of etching a metal foil and a step of removing a resist which is a developing portion (see, for example, Patent Document 7). In Patent Document 7, first, a transparent base film is bonded to one surface of a metal foil with an adhesive, a resist is laminated to the other surface of the metal foil, and a mask having a predetermined mesh pattern is laminated on the resist. After that, ultraviolet rays are irradiated from above the mask, and the resist corresponding to the light transmission part is exposed to form a development resist part. Next, after removing the undeveloped portion of the mask and resist, etching the portion of the metal foil corresponding to the removed undeveloped portion, and then removing the developed resist portion on the metal foil, the resin film and the metal foil mesh The electromagnetic shielding material which consists of was manufactured.

特開平０５−３２７２７４号公報（特許請求の範囲の請求項１、発明の詳細な説明の段落［０００３］）Japanese Patent Laying-Open No. 05-327274 (Claim 1 of Claim, Paragraph [0003] of Detailed Description of the Invention) 特開平０５−２６９９１２号公報（特許請求の範囲の請求項１、発明の詳細な説明の段落［００３５］）Japanese Laid-Open Patent Publication No. 05-269912 (Claim 1 of the Claims, Paragraph [0035] of Detailed Description of the Invention) 特開平０５−２８３８８９号公報（特許請求の範囲の請求項１、発明の詳細な説明の段落［００１５］）Japanese Patent Laid-Open No. 05-282889 (Claim 1 of Claim, Paragraph [0015] of Detailed Description of the Invention) 特開昭６２−０５７２９７号公報（特許請求の範囲(1)）Japanese Patent Application Laid-Open No. 62-057297 (Claims (1)) 特開平０２−０５２４９９号公報（特許請求の範囲）Japanese Patent Laid-Open No. 02-052499 (Claims) 特開平１１−１４５６７６号公報（特許請求の範囲の請求項１、２及び１３、発明の詳細な説明の段落［００２４］）JP-A-11-145676 (claims 1, 2 and 13 of the claims, paragraph [0024] of the detailed description of the invention) 特開平１１−３５０１６８号公報（特許請求の範囲の請求項１、発明の詳細な説明の段落［００１６］〜［００１９］）Japanese Patent Laid-Open No. 11-350168 (claim 1 of claims, paragraphs [0016] to [0019] in the detailed description of the invention)

しかしながら、上記特許文献１や上記特許文献２に示されるような良導電性繊維を用いる方法では、電磁波漏れのないように導電性繊維を規則的に配置させる必要があるが、均一性や制御性に問題があった。また、規則配置の制御性を高めるために導電性繊維の繊維径を太くすると、繊維が見えてしまい視認性が低下してしまう。   However, in the method using the highly conductive fibers as shown in Patent Document 1 and Patent Document 2, it is necessary to regularly arrange the conductive fibers so as not to leak electromagnetic waves. There was a problem. Moreover, when the fiber diameter of the conductive fiber is increased in order to improve the controllability of the regular arrangement, the fiber is visible and the visibility is lowered.

また、上記特許文献３に示されるような無電解めっき法によりパターン状に形成する方法では、廃液が生じる問題があり、またメッシュパターンの作成と無電解めっきの２工程が必要であるため製造コストがかかっていた。   Further, the method of forming a pattern by the electroless plating method as shown in Patent Document 3 has a problem that waste liquid is generated, and also requires two steps of creating a mesh pattern and electroless plating. It was over.

上記特許文献４や上記特許文献５に示されるような印刷法を用いた方法では、使用する塗料が微細配線を印刷するのに最適な組成となっておらず、形成される電磁波シールドの視認性及び導電性が十分に保たれておらず、経年安定性に劣るものであった。   In the method using the printing method as shown in Patent Document 4 and Patent Document 5, the coating material used does not have an optimal composition for printing fine wiring, and the visibility of the formed electromagnetic wave shield is not good. In addition, the conductivity was not sufficiently maintained, and the stability over time was poor.

更に、上記特許文献６や上記特許文献７に示されるようなレジスト法を用いた方法では、製造する際の工程が多いため、製造コストの上昇や歩留まりの悪化といった問題を有していた。また、金属箔をエッチングする際に、金属箔に貼り付けたフィルムの表面がエッチング液によって侵食され、視認性の低下を招く問題もあった。   Furthermore, the method using the resist method as shown in Patent Document 6 or Patent Document 7 has problems such as an increase in manufacturing cost and a decrease in yield because there are many steps in manufacturing. Moreover, when etching metal foil, the surface of the film affixed on metal foil was eroded by the etching solution, and there also existed a problem which caused the visibility fall.

本発明の目的は、透明なフィルムや板状物に格子状もしくは縞状に金属組成物を印刷し、さらに焼成するという方法で、透明なフィルムや板状物の表面に格子状もしくは縞状の配線を配置した構造を有する電磁波遮蔽物において、長年使用しても配線の高導電率を維持することができる、即ち、経年安定性に優れた電磁波遮蔽物を得ることができる、電磁波遮蔽用組成物とその製造方法及び該組成物を用いた電磁波遮蔽物の形成方法を提供することにある。 The object of the present invention is to print a metal composition in a lattice or stripe pattern on a transparent film or plate and further calcinate it, so that the surface of the transparent film or plate has a lattice or stripe pattern. The electromagnetic wave shielding composition having the structure in which the wiring is arranged, the electromagnetic shielding composition capable of maintaining the high electrical conductivity of the wiring even after being used for many years, that is, an electromagnetic shielding material having excellent aging stability. It is providing the manufacturing method of the thing , its manufacturing method, and the electromagnetic wave shielding material using this composition.

本発明の別の目的は、１３０〜４００℃という低温の焼成プロセスにより、比抵抗がバルク金属の１５倍以下という低比抵抗が得られ、かつ、長年使用しても高導電率を維持することができ、経年安定性に優れた電磁波遮蔽物を得ることができる、電磁波遮蔽物の形成方法及び該形成方法により得られた電磁波遮蔽物を用いた電磁波遮蔽性構造体を提供することにある。   Another object of the present invention is to achieve a low specific resistance of 15 times or less that of bulk metal by a low temperature firing process of 130 to 400 ° C., and to maintain a high conductivity even after many years of use. It is possible to provide an electromagnetic wave shielding material that can be obtained and that can provide an electromagnetic wave shielding material that is excellent in aging stability, and an electromagnetic wave shielding structure that uses the electromagnetic wave shielding material obtained by the formation method.

請求項１に係る発明は、金属ナノ粒子が分散媒に分散した電磁波遮蔽用組成物であって、金属ナノ粒子が７５質量％以上の銀ナノ粒子と、銀ナノ粒子以外の金属ナノ粒子を含有し、銀ナノ粒子以外の金属ナノ粒子がＭｎの金属ナノ粒子であり、金属ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤で化学修飾され、金属ナノ粒子が一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上含有し、分散媒がエチレングリコールを含むことを特徴とする。 The invention according to claim 1 is an electromagnetic wave shielding composition in which metal nanoparticles are dispersed in a dispersion medium, the metal nanoparticles containing 75% by mass or more of silver nanoparticles and metal nanoparticles other than silver nanoparticles and metal nanoparticles other than silver nanoparticles is the Mn metal nanoparticles element, the metal nanoparticles carbon skeleton is chemically modified with a protective agent of the organic molecular main chain of 3 carbon atoms, a primary particle diameter metal nanoparticles The metal nanoparticles in the range of 50 to 200 nm are contained in an average number of 70% or more, and the dispersion medium contains ethylene glycol .

この請求項１に記載された組成物では、一次粒径５０〜２００ｎｍとサイズの比較的大きな金属ナノ粒子を多く含むため、金属ナノ粒子の比表面積が減少し、分散媒の占める割合が小さくなるため、この組成物を用いて電磁波遮蔽物を形成すると、上記分散媒中の有機分子が焼成時の熱により脱離し又は分解し、或いは離脱しかつ分解することにより、高導電率や耐候性を悪化させるような有機物を実質的に含有しない銀を主成分とする高導電率の電磁波遮蔽物が得られる。   In the composition described in claim 1, since it contains a large number of metal nanoparticles having a primary particle size of 50 to 200 nm and a relatively large size, the specific surface area of the metal nanoparticles is reduced and the proportion of the dispersion medium is reduced. Therefore, when an electromagnetic wave shielding material is formed using this composition, the organic molecules in the dispersion medium are desorbed or decomposed by heat at the time of firing, or desorbed and decomposed, thereby providing high conductivity and weather resistance. A highly conductive electromagnetic shielding material mainly composed of silver that does not substantially contain an organic substance that deteriorates is obtained.

請求項２に係る発明は、請求項１に係る発明であって、上記金属ナノ粒子を化学修飾する上記保護剤がカルボニル基又は水酸基のいずれか一方又は双方を含む電磁波遮蔽用組成物である。The invention according to claim 2 is the electromagnetic wave shielding composition according to claim 1, wherein the protective agent for chemically modifying the metal nanoparticles contains either one or both of a carbonyl group and a hydroxyl group.

請求項３に係る発明は、請求項１又は２に係る発明であって、銀ナノ粒子以外の金属ナノ粒子を０．０２質量％以上かつ２５質量％未満含有する電磁波遮蔽用組成物である。 The invention according to claim 3 is the electromagnetic wave shielding composition according to claim 1 or 2 , which contains 0.02% by mass or more and less than 25% by mass of metal nanoparticles other than silver nanoparticles.

請求項４に係る発明は、請求項１ないし３いずれか１項に記載の電磁波遮蔽用組成物を製造する方法であって、硝酸銀を水に溶解して金属塩水溶液を調製する工程と、クエン酸ナトリウム水溶液に硫酸第一鉄を加えて溶解させることにより還元剤水溶液を調製する工程と、上記還元剤水溶液に前記金属塩水溶液を滴下して混合、攪拌することにより金属コロイドからなる分散液を調製する工程と、上記分散液を室温で放置し、沈降した金属ナノ粒子の凝集物を分離した後、得られた分離物に水を加えて分散体とする工程とを含む電磁波遮蔽用組成物の製造方法である。 The invention according to claim 4 is a method for producing the electromagnetic wave shielding composition according to any one of claims 1 to 3, wherein a step of preparing a metal salt aqueous solution by dissolving silver nitrate in water, A step of preparing a reducing agent aqueous solution by adding ferrous sulfate to an aqueous sodium acid solution and dissolving the solution, and adding a metal salt aqueous solution dropwise to the reducing agent aqueous solution, mixing and stirring to obtain a dispersion composed of a metal colloid. An electromagnetic wave shielding composition comprising: a step of preparing; and a step of allowing the dispersion to stand at room temperature to separate agglomerated metal nanoparticle aggregates, and then adding water to the resulting separation to form a dispersion. It is a manufacturing method.

請求項５に係る発明は、請求項４に係る発明であって、上記還元剤水溶液に上記金属塩水溶液を滴下して混合、攪拌する際の反応温度を３０〜６０℃、攪拌時間を１０〜３００分間とし、上記分散体とする工程の後、この分散体を限外ろ過により脱塩処理し、更に水と相溶する有機溶媒で置換洗浄する工程とを含む電磁波遮蔽用組成物の製造方法である。 The invention according to claim 5 is the invention according to claim 4 , wherein the metal salt aqueous solution is dropped into the reducing agent aqueous solution, mixed, and stirred, the reaction temperature is 30 to 60 ° C., and the stirring time is 10 to 10. A method for producing an electromagnetic wave shielding composition comprising: 300 minutes, and after the step of forming the dispersion, the dispersion is subjected to a desalting treatment by ultrafiltration, and further subjected to substitution washing with an organic solvent compatible with water. It is.

請求項６に係る発明は、請求項１ないし３いずれか１項に記載の電磁波遮蔽用組成物を基材上に印刷する工程と、上面に印刷された基材を１３０〜４００℃で焼成する工程とを含む電磁波遮蔽物の形成方法である。 The invention according to claim 6 is a step of printing the electromagnetic wave shielding composition according to any one of claims 1 to 3 on the substrate, and firing the substrate printed on the upper surface at 130 to 400 ° C. A method for forming an electromagnetic wave shielding material including a process.

この請求項６に記載された電磁波遮蔽物の形成方法では、１３０〜４００℃という低温での焼成により、金属ナノ粒子の表面を保護していた分散媒中の有機分子が脱離し又は分解し、或いは離脱しかつ分解することにより、高導電率や耐候性を悪化させるような有機物を実質的に含有しない銀を主成分とする電磁波遮蔽物が得られる。 In the method for forming an electromagnetic wave shielding object according to claim 6 , organic molecules in the dispersion medium protecting the surface of the metal nanoparticles are desorbed or decomposed by firing at a low temperature of 130 to 400 ° C., Alternatively, by separating and decomposing, an electromagnetic wave shielding material mainly composed of silver that does not substantially contain an organic substance that deteriorates high conductivity and weather resistance can be obtained.

請求項７に係る発明は、請求項６に係る発明であって、基材が高分子材料からなる基板又は高分子材料を含む２層以上の積層体である電磁波遮蔽物の形成方法である。 The invention according to claim 7 is the method according to claim 6 , wherein the base material is a substrate made of a polymer material or an electromagnetic shielding material that is a laminate of two or more layers containing the polymer material.

請求項８に係る発明は、請求項６又は７に係る発明であって、印刷方法がインクジェット印刷法、ディスペンサコーティング法、スプレーコーティング法、スクリーン印刷法、グラビア印刷法、凸版印刷法、フレキソ印刷法又はオフセット印刷法のいずれかである電磁波遮蔽物の形成方法である。 The invention according to claim 8 is the invention according to claim 6 or 7 , wherein the printing method is an ink jet printing method, a dispenser coating method, a spray coating method, a screen printing method, a gravure printing method, a letterpress printing method, a flexographic printing method. Or it is the formation method of the electromagnetic wave shield which is either the offset printing method.

以上述べたように、本発明によれば、分散媒に分散された金属ナノ粒子が７５質量％以上の銀ナノ粒子と、銀ナノ粒子以外の金属ナノ粒子を含有し、銀ナノ粒子以外の金属ナノ粒子がＭｎの金属ナノ粒子であり、炭素骨格が炭素数３の有機分子主鎖の保護剤で金属ナノ粒子を化学修飾し、更に金属ナノ粒子が一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上含有し、分散媒がエチレングリコールを含むので、この組成物中の金属ナノ粒子の比表面積が比較的減少し、分散媒の占める割合が小さくなる。この結果、この組成物を用いて電磁波遮蔽物を形成すると、上記分散媒中の有機分子が焼成時の熱により脱離し又は分解し、或いは離脱しかつ分解することにより、高導電率や耐候性を悪化させるような有機物を実質的に含有しない銀を主成分とする電磁波遮蔽物が得られる。従って、上記遮蔽物の形成された電磁波遮蔽性構造体を長年使用しても、有機物が変質又は劣化するということがなく、導電率が高い状態に維持されるので、経年安定性に優れた電磁波遮蔽物を得ることができる。
As described above, according to the present invention, the metal nanoparticles dispersed in the dispersion medium contain 75% by mass or more of silver nanoparticles and metal nanoparticles other than silver nanoparticles, and a metal other than silver nanoparticles. nanoparticles Ri metal nanoparticles der of Mn, carbon skeleton metal nanoparticles chemically modified with a protective agent of the organic molecular main chain of 3 carbon atoms, still within the scope of the metal nanoparticles primary particle size 50~200nm Since the metal nanoparticles are contained in a number average of 70% or more and the dispersion medium contains ethylene glycol, the specific surface area of the metal nanoparticles in the composition is relatively reduced, and the proportion of the dispersion medium is reduced. As a result, when an electromagnetic wave shielding material is formed using this composition, the organic molecules in the dispersion medium are desorbed or decomposed by the heat at the time of firing, or are detached and decomposed, resulting in high conductivity and weather resistance. As a result, an electromagnetic wave shielding material mainly composed of silver that does not substantially contain an organic substance that deteriorates the pH is obtained. Therefore, even if the electromagnetic shielding structure having the shielding material is used for many years, the organic matter is not deteriorated or deteriorated, and the electrical conductivity is maintained in a high state. A shield can be obtained.

また上記電磁波遮蔽用組成物を基材上に印刷し、この上面に印刷された基材を１３０〜４００℃で焼成すれば、金属ナノ粒子の表面を保護していた分散媒中の有機分子が脱離し又は分解し、或いは離脱しかつ分解することにより、高導電率や耐候性を悪化させるような有機物を実質的に含有しない銀を主成分とする電磁波遮蔽物が得られる。この結果、上記と同様に、電磁波遮蔽物の形成された電磁波遮蔽性構造体を長年使用しても、導電率が高い状態に維持されるので、経年安定性に優れた電磁波遮蔽物を得ることができる。   Moreover, if the said electromagnetic wave shielding composition is printed on a base material and the base material printed on this upper surface is baked at 130-400 degreeC, the organic molecule in the dispersion medium which protected the surface of the metal nanoparticle will become. By desorbing or decomposing, or desorbing and decomposing, an electromagnetic wave shielding material mainly composed of silver that does not substantially contain an organic substance that deteriorates high conductivity and weather resistance can be obtained. As a result, similarly to the above, even if the electromagnetic wave shielding structure with the electromagnetic wave shielding material formed is used for many years, the electrical conductivity is maintained in a high state, so that an electromagnetic wave shielding material with excellent aging stability can be obtained. Can do.

次に本発明を実施するための形態を説明する。 Next will be described the shape condition for carrying out the present invention.

本発明の組成物は、金属ナノ粒子が分散媒に分散した電磁波遮蔽用組成物である。上記金属ナノ粒子は７５質量％以上、好ましくは８０質量％以上の銀ナノ粒子を含有する。また金属ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤で化学修飾される。更に金属ナノ粒子は一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上、好ましくは７５％以上含有する。ここで、銀ナノ粒子の含有量を全ての金属ナノ粒子１００質量％に対して７５質量％以上の範囲に限定したのは、７５質量％未満ではこの組成物を用いて形成された電磁波遮蔽物の導電率が低下し、従って電磁波遮蔽性が低下してしまうからである。また金属ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数を３に限定したのは、炭素数が４以上であると焼成時の熱により保護剤が脱離或いは分解（分離・燃焼）し難く、上記電磁波遮蔽物内に有機残渣が多く残り、変質又は劣化して電磁波遮蔽物の導電性が低下してしまうからである。また一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子の含有量を、数平均で全ての金属ナノ粒子１００％に対して７０％以上の範囲に限定したのは、７０％未満では金属ナノ粒子の比表面積が増大して有機物の占める割合が大きくなり、焼成時の熱により脱離或いは分解（分離・燃焼）し易い有機分子であっても、この有機分子の占める割合が多いため、電磁波遮蔽物内に有機残渣が多く残り、この残渣が変質又は劣化して電磁波遮蔽物の導電性が低下したり、或いは金属ナノ粒子の粒度分布が広くなり電磁波遮蔽物の密度が低下し易くなって、電磁波遮蔽物の導電性が低下してしまうからである。更に上記金属ナノ粒子の一次粒径を５０〜２００ｎｍの範囲内に限定したのは、統計的手法より一次粒径が５０〜２００ｎｍの範囲内にある金属ナノ粒子が経時安定性（経年安定性）と相関しているからである。 The composition of the present invention is an electromagnetic shielding composition in which metal nanoparticles are dispersed in a dispersion medium. The metal nanoparticles contain 75% by mass or more, preferably 80% by mass or more of silver nanoparticles. The metal nanoparticles are chemically modified with a protective agent having an organic molecular main chain having a carbon skeleton of 3 carbon atoms. Further, the metal nanoparticles contain 70% or more, preferably 75% or more, of metal nanoparticles having a primary particle size in the range of 50 to 200 nm in number average. Here, the content of silver nanoparticles was limited to a range of 75% by mass or more with respect to 100% by mass of all metal nanoparticles, and the electromagnetic wave shielding material formed using this composition was less than 75% by mass. This is because the electrical conductivity is reduced, and therefore the electromagnetic wave shielding properties are reduced. Moreover, the carbon number of the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying the metal nanoparticles is limited to 3 because the protective agent is desorbed or decomposed by the heat during firing if the carbon number is 4 or more ( This is because it is difficult to separate and burn), and a large amount of organic residue remains in the electromagnetic wave shielding material, and the electrical conductivity of the electromagnetic wave shielding material decreases due to deterioration or deterioration. In addition, the content of metal nanoparticles in the primary particle size range of 50 to 200 nm is limited to a range of 70% or more with respect to 100% of all metal nanoparticles in terms of number average. As the specific surface area increases, the proportion of organic matter increases, and even organic molecules that are easily desorbed or decomposed (separated or burned) by the heat during firing are used to shield electromagnetic waves. Many organic residues remain in the object, and the residue is altered or deteriorated to reduce the conductivity of the electromagnetic wave shielding object, or the particle size distribution of the metal nanoparticles is widened, and the density of the electromagnetic wave shielding object is easily lowered. This is because the conductivity of the electromagnetic wave shielding object is lowered. Furthermore, the primary particle size of the metal nanoparticles was limited to the range of 50 to 200 nm because the metal nanoparticles having a primary particle size within the range of 50 to 200 nm were stable over time (statistical stability). It is because it correlates.

一方、銀ナノ粒子を含む金属ナノ粒子の含有量は、金属ナノ粒子及び分散媒からなる組成物１００質量％に対して２．５〜９５．０質量％、好ましくは３．５〜９０．０質量％含有する。また分散媒は、本発明による金属ナノ粒子を分散させるような溶剤であれば特に限定することなく使用することができるが、中でも水と相溶する有機溶剤が好ましい。更に分散剤、即ち金属ナノ粒子表面に化学修飾している保護分子は、水酸基（−ＯＨ）又はカルボニル基（−Ｃ＝Ｏ）のいずれか一方又は双方を含有する。ここで、銀ナノ粒子を含む金属ナノ粒子の含有量を金属ナノ粒子及び分散媒からなる組成物１００質量％に対して２．５〜９５．０質量％の範囲に限定したのは、２．５質量％未満では特に焼成後の電磁波遮蔽物の特性には影響はないけれども、必要な厚さの電磁波遮蔽物を得ることが難しく、９５．０質量％を越えると組成物を印刷する時にインク或いはペーストとしての必要な流動性を失ってしまうからである。なお、水酸基（−ＯＨ）が銀ナノ粒子等の金属ナノ粒子を化学修飾する保護剤に含有されると、組成物の分散安定性に優れ、膜の低温焼結にも効果的な作用があり、カルボニル基（−Ｃ＝Ｏ）が銀ナノ粒子等の金属ナノ粒子を化学修飾する保護剤に含有されると、上記と同様に組成物の分散安定性に優れ、膜の低温焼結にも効果的な作用がある。   On the other hand, the content of the metal nanoparticles including silver nanoparticles is 2.5 to 95.0% by mass, preferably 3.5 to 90.0% with respect to 100% by mass of the composition comprising the metal nanoparticles and the dispersion medium. Contains by mass%. The dispersion medium can be used without any particular limitation as long as it is a solvent that can disperse the metal nanoparticles according to the present invention. Among them, an organic solvent that is compatible with water is preferable. Furthermore, the dispersing agent, that is, the protective molecule chemically modified on the surface of the metal nanoparticle contains one or both of a hydroxyl group (—OH) and a carbonyl group (—C═O). Here, the content of the metal nanoparticles including the silver nanoparticles was limited to the range of 2.5 to 95.0% by mass with respect to 100% by mass of the composition composed of the metal nanoparticles and the dispersion medium. If the content is less than 5% by mass, the properties of the electromagnetic wave shielding material after firing are not particularly affected. However, it is difficult to obtain an electromagnetic wave shielding material having a required thickness. Alternatively, the necessary fluidity as a paste is lost. In addition, when a hydroxyl group (—OH) is contained in a protective agent that chemically modifies metal nanoparticles such as silver nanoparticles, the composition has excellent dispersion stability and has an effective action for low-temperature sintering of the film. When a carbonyl group (—C═O) is contained in a protective agent that chemically modifies metal nanoparticles such as silver nanoparticles, the composition has excellent dispersion stability as described above, and can be used for low-temperature sintering of a film. There is an effective action.

一方、銀ナノ粒子以外の金属ナノ粒子は、Ａｕ、Ｐｔ、Ｐｄ、Ｒｕ、Ｎｉ、Ｃｕ、Ｓｎ、Ｉｎ、Ｚｎ、Ｆｅ、Ｃｒ及びＭｎからなる群より選ばれた１種又は２種以上の混合組成又は合金組成からなる金属ナノ粒子であり、この銀ナノ粒子以外の金属ナノ粒子は全ての金属ナノ粒子１００質量％に対して０．０２質量％以上かつ２５質量％未満、好ましくは０．０３質量％〜２０質量％含有する。また上記水と相溶する有機溶剤は、例えば、メタノール、エタノール、２−プロパノール、エチレングリコール、１，２−プロパンジオール、２−メチル−２，４−ペンタンジオール等のアルコール類、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等のグリコールエーテル類、Ｎ−メチルホルムアミド、Ｎ，Ｎ−ジメチルホルムアミド等のアミド類、アセトン等のケトン類からなる群より選ばれた１種又は２種以上を使用することができる。ここで、銀ナノ粒子以外の金属ナノ粒子の含有量を全ての金属ナノ粒子１００質量％に対して０．０２質量％以上かつ２５質量％未満の範囲に限定したのは、０．０２質量％未満では特に大きな問題はないけれども、０．０２〜２５質量％の範囲内においては、耐候性試験（温度１００℃かつ湿度５０％の恒温恒湿槽に１０００時間保持する試験）後の電磁波遮蔽物の導電性が耐候性試験前より悪化しないという特徴があり、２５質量％以上では焼成直後の電磁波遮蔽物の導電性が低下し、しかも耐候性試験後の電磁波遮蔽物が耐候性試験前の電磁波遮蔽物より導電性が低下してしまうからである。   On the other hand, the metal nanoparticles other than silver nanoparticles are one or a mixture of two or more selected from the group consisting of Au, Pt, Pd, Ru, Ni, Cu, Sn, In, Zn, Fe, Cr and Mn. It is a metal nanoparticle which consists of a composition or an alloy composition, and metal nanoparticles other than this silver nanoparticle are 0.02 mass% or more and less than 25 mass% with respect to 100 mass% of all metal nanoparticles, Preferably it is 0.03. It is contained in an amount of 20% to 20% by mass. Examples of the organic solvent compatible with water include alcohols such as methanol, ethanol, 2-propanol, ethylene glycol, 1,2-propanediol, and 2-methyl-2,4-pentanediol, and ethylene glycol monomethyl ether. , One or more selected from the group consisting of glycol ethers such as ethylene glycol monoethyl ether, amides such as N-methylformamide and N, N-dimethylformamide, and ketones such as acetone. Can do. Here, the content of metal nanoparticles other than silver nanoparticles is limited to 0.02% by mass or more and less than 25% by mass with respect to 100% by mass of all metal nanoparticles. If there is no particular problem, the electromagnetic wave shielding material after a weather resistance test (a test held in a constant temperature and humidity chamber at a temperature of 100 ° C. and a humidity of 50% for 1000 hours) is within the range of 0.02 to 25% by mass. The conductivity of the electromagnetic wave shielding material immediately after firing is reduced at 25% by mass or more, and the electromagnetic wave shielding material after the weathering test is an electromagnetic wave before the weathering test. This is because the conductivity is lower than that of the shield.

このように構成された電磁波遮蔽用組成物の製造方法を説明する。   A method for producing the electromagnetic wave shielding composition thus configured will be described.

(a) 銀ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数を３とする場合
先ず硝酸銀を脱イオン水等の水に溶解して金属塩水溶液を調製する。一方、クエン酸ナトリウムを脱イオン水等の水に溶解させて得られた濃度１０〜４０％のクエン酸ナトリウム水溶液に、窒素ガス等の不活性ガスの気流中で粒状又は粉状の硫酸第一鉄を直接加えて溶解させ、クエン酸イオンと第一鉄イオンを３：２のモル比で含有する還元剤水溶液を調製する。次に上記不活性ガス気流中で上記還元剤水溶液を撹拌しながら、この還元剤水溶液に上記金属塩水溶液を滴下して混合する。ここで、金属塩水溶液の添加量は還元剤水溶液の量の１／１０以下になるように、各溶液の濃度を調整することで、室温の金属塩水溶液を滴下しても反応温度が３０〜６０℃に保持されるようにすることが好ましい。また上記両水溶液の混合比は、還元剤として加えられる第１鉄イオンの当量が、金属イオンの当量の３倍となるように調整する。即ち、（金属塩水溶液中の金属イオンのモル数）×（金属イオンの価数）＝３×（還元剤水溶液中の第１鉄イオンのモル数）となるように調整する。金属塩水溶液の滴下が終了した後、混合液の撹拌を更に１０〜３００分間続けて金属コロイドからなる分散液を調製する。この分散液を室温で放置し、沈降した金属ナノ粒子の凝集物をデカンテーションや遠心分離法等により分離した後、この分離物に脱イオン水等の水を加えて分散体とし、限外ろ過により脱塩処理し、更に引き続いて水と相溶する有機溶剤で置換洗浄して、金属（銀）の含有量を２．５〜５０質量％にする。その後、遠心分離機を用いこの遠心分離機の遠心力を調整して粗粒子を分離することにより、金属ナノ粒子が一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上含有するように調製する、即ち数平均で全ての金属ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子の占める割合が７０％以上になるように調整する。なお、金属ナノ粒子と記載したが、この(a)の場合では、数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの範囲内の銀ナノ粒子の占める割合が７０％以上になるように調整している。 (a) When the carbon number of the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying the silver nanoparticles is set to 3 First, silver nitrate is dissolved in water such as deionized water to prepare an aqueous metal salt solution. On the other hand, the aqueous solution of sodium citrate having a concentration of 10 to 40% obtained by dissolving sodium citrate in deionized water or the like is mixed with granular or powdered sulfuric acid in a stream of inert gas such as nitrogen gas. Iron is directly added and dissolved to prepare an aqueous reducing agent solution containing citrate ions and ferrous ions in a molar ratio of 3: 2. Next, the aqueous metal salt solution is added dropwise to and mixed with the reducing agent aqueous solution while stirring the reducing agent aqueous solution in the inert gas stream. Here, by adjusting the concentration of each solution so that the addition amount of the metal salt aqueous solution is 1/10 or less of the amount of the reducing agent aqueous solution, the reaction temperature is 30 to 30 even when the metal salt aqueous solution at room temperature is dropped. It is preferable to keep the temperature at 60 ° C. The mixing ratio of the two aqueous solutions is adjusted so that the equivalent of ferrous ions added as a reducing agent is three times the equivalent of metal ions. That is, the number of moles of metal ions in the aqueous solution of metal salt × (valence of metal ions) = 3 × (number of moles of ferrous ions in the aqueous reducing agent solution) is adjusted. After the dropping of the aqueous metal salt solution is completed, the mixture is further stirred for 10 to 300 minutes to prepare a dispersion composed of metal colloid. This dispersion is allowed to stand at room temperature, and the aggregates of the precipitated metal nanoparticles are separated by decantation, centrifugation, etc., and then water such as deionized water is added to the separation to form a dispersion, followed by ultrafiltration. The metal (silver) content is adjusted to 2.5 to 50% by mass by subjecting to a desalting treatment and subsequent substitution washing with an organic solvent compatible with water. Thereafter, by adjusting the centrifugal force of the centrifuge using a centrifuge to separate coarse particles, the number of metal nanoparticles having a primary particle size in the range of 50 to 200 nm is 70% or more on average. It adjusts so that the ratio for which the metal nanoparticle in the range of the primary particle size of 50-200 nm occupies 70% or more with respect to 100% of all the metal nanoparticles may be prepared. Although described as metal nanoparticles, in the case of (a), the proportion of silver nanoparticles in the range of primary particle size of 50 to 200 nm with respect to 100% of all silver nanoparticles is 70% or more. It is adjusted so that

数平均の測定方法は、先ず、得られた金属ナノ粒子をＴＥＭ（Transmission Electron Microscope、透過型電子顕微鏡）により約５０万倍程度の倍率で撮影する。次いで、得られた画像から金属ナノ粒子２００個について一次粒径を測定し、この測定結果をもとに粒径分布を作成する。次に、作成した粒径分布から、一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子が全金属ナノ粒子で占める個数割合を求める。   In the number average measurement method, first, the obtained metal nanoparticles are photographed with a TEM (Transmission Electron Microscope) at a magnification of about 500,000 times. Next, a primary particle size is measured for 200 metal nanoparticles from the obtained image, and a particle size distribution is created based on the measurement result. Next, from the created particle size distribution, the ratio of the number of metal nanoparticles within the range of the primary particle size of 50 to 200 nm occupied by all metal nanoparticles is determined.

これにより銀ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数が３である分散体（電磁波遮蔽用組成物）が得られる。なお、この分散体１００質量％に対する最終的な金属含有量（銀含有量）は２．５〜９５質量％とする。   Thereby, a dispersion (composition for electromagnetic wave shielding) having 3 carbon atoms in the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying the silver nanoparticles is obtained. The final metal content (silver content) with respect to 100% by mass of the dispersion is 2.5 to 95% by mass.

(b) 銀ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数を２とする場合
還元剤水溶液を調製するときに用いたクエン酸ナトリウムをりんご酸ナトリウムに替えること以外は上記(a)と同様にして分散体を調製する。これにより銀ナノ粒子を化学修飾する有機分子主鎖の炭素骨格の炭素数が２である分散体（電磁波遮蔽用組成物）が得られる。 (b) When the carbon number of the carbon skeleton of the organic molecular main chain of the protective agent that chemically modifies the silver nanoparticles is 2, except that the sodium citrate used when preparing the reducing agent aqueous solution is replaced with sodium malate A dispersion is prepared in the same manner as in the above (a). Thereby, a dispersion (composition for electromagnetic wave shielding) having 2 carbon atoms in the carbon skeleton of the organic molecular main chain that chemically modifies the silver nanoparticles is obtained.

(c) 銀ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数を１とする場合
還元剤水溶液を調製するときに用いたクエン酸ナトリウムをグリコール酸ナトリウムに替えること以外は上記(a)と同様にして分散体を調製する。これにより銀ナノ粒子を化学修飾する有機分子主鎖の炭素骨格の炭素数が１である分散体（電磁波遮蔽用組成物）が得られる。 (c) When the carbon number of the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying the silver nanoparticles is 1, except that sodium citrate used when preparing the reducing agent aqueous solution is replaced with sodium glycolate A dispersion is prepared in the same manner as in the above (a). Thereby, the dispersion (composition for electromagnetic wave shielding) in which the carbon number of the carbon skeleton of the organic molecular main chain for chemically modifying the silver nanoparticles is 1 is obtained.

(d) 銀ナノ粒子以外の金属ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数を３とする場合
銀ナノ粒子以外の金属ナノ粒子を構成する金属としては、Ａｕ、Ｐｔ、Ｐｄ、Ｒｕ、Ｎｉ、Ｃｕ、Ｓｎ、Ｉｎ、Ｚｎ、Ｆｅ、Ｃｒ又はＭｎが挙げられる。金属塩水溶液を調製するときに用いた硝酸銀を、塩化金酸、塩化白金酸、硝酸パラジウム、三塩化ルテニウム、塩化ニッケル、硝酸第一銅、二塩化錫、硝酸インジウム、塩化亜鉛、硫酸鉄、硫酸クロム又は硫酸マンガンに替えること以外は上記(a)と同様にして分散体を調製する。これにより銀ナノ粒子以外の金属ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数が３である分散体（電磁波遮蔽用組成物）が得られる。 (d) When the number of carbon atoms in the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying metal nanoparticles other than silver nanoparticles is 3, the metal constituting the metal nanoparticles other than silver nanoparticles is Au, Pt, Pd, Ru, Ni, Cu, Sn, In, Zn, Fe, Cr, or Mn may be mentioned. The silver nitrate used to prepare the aqueous metal salt solution is chloroauric acid, chloroplatinic acid, palladium nitrate, ruthenium trichloride, nickel chloride, cuprous nitrate, tin dichloride, indium nitrate, zinc chloride, iron sulfate, sulfuric acid A dispersion is prepared in the same manner as in the above (a) except that it is replaced with chromium or manganese sulfate. Thereby, the dispersion (composition for electromagnetic wave shielding) whose carbon number of the carbon skeleton of the organic molecular principal chain of the protective agent for chemically modifying the metal nanoparticles other than the silver nanoparticles is 3 is obtained.

なお、銀ナノ粒子以外の金属ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数を１や２とする場合、金属塩水溶液を調製するときに用いた硝酸銀を、上記種類の金属塩に替えること以外は上記(b)や上記(c)と同様にして分散体を調製する。これにより、銀ナノ粒子以外の金属ナノ粒子を化学修飾する保護剤の有機分子主鎖の炭素骨格の炭素数が１や２である分散体（電磁波遮蔽用組成物）が得られる。   In addition, when the carbon number of the carbon skeleton of the organic molecular main chain of the protective agent that chemically modifies the metal nanoparticles other than the silver nanoparticles is 1 or 2, the silver nitrate used when preparing the metal salt aqueous solution is the above kind. A dispersion is prepared in the same manner as in the above (b) and (c) except that the metal salt is replaced. Thereby, the dispersion (composition for electromagnetic wave shielding) in which the carbon number of the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying the metal nanoparticles other than the silver nanoparticles is 1 or 2.

金属ナノ粒子として、銀ナノ粒子とともに、銀ナノ粒子以外の金属ナノ粒子を含有させる場合には、上記(a)の方法で製造した銀ナノ粒子を含む分散体を第１分散体とし、上記(d)の方法で製造した銀ナノ粒子以外の金属ナノ粒子を含む分散体を第２分散体とすると、７５質量％以上の第１分散体と２５質量％未満の第２分散体とを第１及び第２分散体の合計含有量が１００質量％となるように混合する。なお、第１分散体は、上記(a)の方法で製造した銀ナノ粒子を含む分散体に留まらず、上記(b)の方法で製造した銀ナノ粒子を含む分散体や上記(c)の方法で製造した銀ナノ粒子を含む分散体を使用しても良い。   When metal nanoparticles other than silver nanoparticles are contained together with silver nanoparticles as metal nanoparticles, a dispersion containing silver nanoparticles produced by the method of (a) is used as the first dispersion, and ( When the dispersion containing metal nanoparticles other than silver nanoparticles produced by the method of d) is defined as the second dispersion, the first dispersion of 75% by mass or more and the second dispersion of less than 25% by mass are the first. And it mixes so that the total content of a 2nd dispersion may be 100 mass%. The first dispersion is not limited to the dispersion containing the silver nanoparticles produced by the method (a), but the dispersion containing the silver nanoparticles produced by the method (b) or the above (c). You may use the dispersion containing the silver nanoparticle manufactured by the method.

このように製造された分散体（電磁波遮蔽用組成物）を用いて電磁波遮蔽物を形成する方法を説明する。   A method of forming an electromagnetic wave shielding material using the dispersion (composition for electromagnetic wave shielding) thus produced will be described.

先ず上記分散体（電磁波遮蔽用組成物）を基材上に印刷する。焼成後の厚さは、要求される電磁波遮蔽能が得られるような表面抵抗値になるように印刷する。上記基材は、高分子材料からなる基板又は高分子材料を含む２層以上の積層体であることができる。更に上記印刷方法は、スプレーコーティング法、ディスペンサコーティング法、スピンコーティング法、ナイフコーティング法、スリットコーティング法、インクジェットコーティング法、スクリーン印刷法、オフセット印刷法又はダイコーティング法のいずれかであることが特に好ましいが、これに限られるものではなく、あらゆる方法を利用できる。スプレーコーティング法は分散体を圧縮エアにより霧状にして基材に塗布したり、或いは分散体自体を加圧し霧状にして基材に塗布する方法であり、ディスペンサコーティング法は例えば分散体を注射器に入れこの注射器のピストンを押すことにより注射器先端の微細ノズルから分散体を吐出させて基材に塗布する方法である。スピンコーティング法は分散体を回転している基材上に滴下し、この滴下した分散体をその遠心力により基材周縁に拡げる方法であり、ナイフコーティング法はナイフの先端と所定の隙間をあけた基材を水平方向に移動可能に設け、このナイフより上流側の基材上に分散体を供給して基材を下流側に向って水平移動させる方法である。スリットコーティング法は分散体を狭いスリットから流出させて基材上に塗布する方法であり、インクジェットコーティング法は市販のインクジェットプリンタのインクカートリッジに分散体を充填し、基材上にインクジェット印刷する方法である。スクリーン印刷法は、パターン指示材として紗を用い、その上に作られた版画像を通して分散体を基材に転移させる方法である。オフセット印刷法は、版に付けた分散体を直接基材に付着させず、版から一度ゴムシートに転写させ、ゴムシートから改めて基材に転移させる、インクの撥水性を利用した印刷方法である。ダイコーティング法は、ダイ内に供給された分散体をマニホールドで分配させてスリットより薄膜上に押し出し、走行する基材の表面を塗工する方法である。ダイコーティング法には、スロットコート方式やスライドコート方式、カーテンコート方式がある。   First, the dispersion (composition for shielding electromagnetic waves) is printed on a substrate. The thickness after baking is printed so as to obtain a surface resistance value that provides the required electromagnetic shielding ability. The base material may be a substrate made of a polymer material or a laminate of two or more layers containing the polymer material. Further, the printing method is particularly preferably any one of a spray coating method, a dispenser coating method, a spin coating method, a knife coating method, a slit coating method, an ink jet coating method, a screen printing method, an offset printing method or a die coating method. However, the present invention is not limited to this, and any method can be used. The spray coating method is a method in which the dispersion is atomized by compressed air and applied to the substrate, or the dispersion itself is pressurized and atomized to apply to the substrate. The dispenser coating method is, for example, a method in which the dispersion is injected into a syringe. The dispersion is discharged from the fine nozzle at the tip of the syringe and applied to the substrate by pushing the piston of the syringe. The spin coating method is a method in which a dispersion is dropped onto a rotating substrate, and the dropped dispersion is spread to the periphery of the substrate by its centrifugal force. The knife coating method leaves a predetermined gap from the tip of the knife. In this method, the substrate is provided so as to be movable in the horizontal direction, the dispersion is supplied onto the substrate upstream of the knife, and the substrate is moved horizontally toward the downstream side. The slit coating method is a method in which a dispersion is discharged from a narrow slit and applied onto a substrate, and the inkjet coating method is a method in which a dispersion is filled in an ink cartridge of a commercially available inkjet printer and ink jet printing is performed on the substrate. is there. The screen printing method is a method in which wrinkles are used as a pattern indicating material and a dispersion is transferred to a substrate through a plate image formed thereon. The offset printing method is a printing method utilizing the water repellency of ink, in which the dispersion attached to the plate is not directly attached to the substrate, but is transferred from the plate to a rubber sheet and then transferred from the rubber sheet to the substrate again. . The die coating method is a method in which a dispersion supplied in a die is distributed by a manifold and extruded onto a thin film from a slit to coat the surface of a traveling substrate. The die coating method includes a slot coat method, a slide coat method, and a curtain coat method.

次に上面に印刷された基材を大気中で１３０〜４００℃、好ましくは１４０〜２００℃の温度に、３分間〜１時間、好ましくは１５〜４０分間保持して焼成する。ここで、基材上に印刷された分散体の膜の焼成温度を１３０〜４００℃の範囲に限定したのは、１３０℃未満では金属ナノ粒子同士の焼結が不十分になるとともに保護剤の焼成時の熱により脱離或いは分解（分離・燃焼）し難いため、焼成後の電磁波遮蔽物内に有機残渣が多く残り、この残渣が変質又は劣化して導電性が低下してしまい、４００℃を越えると低温プロセスという生産上のメリットを生かせない、即ち製造コストが増大し生産性が低下してしまうからである。更に基材上に印刷された分散体の膜の焼成時間を３分間〜１時間の範囲に限定したのは、３分間未満では金属ナノ粒子同士の焼結が不十分になるとともに保護剤の焼成時の熱により脱離或いは分解（分離・燃焼）し難いため、焼成後の電磁波遮蔽物内に有機残渣が多く残り、この残渣が変質又は劣化して電極の導電性が低下してしまい、１時間を越えると特性には影響しないけれども、必要以上に製造コストが増大して生産性が低下してしまうからである。   Next, the substrate printed on the upper surface is fired in the air at a temperature of 130 to 400 ° C., preferably 140 to 200 ° C. for 3 minutes to 1 hour, preferably 15 to 40 minutes. Here, the reason for limiting the firing temperature of the dispersion film printed on the substrate to the range of 130 to 400 ° C. is that when the temperature is less than 130 ° C., the sintering between the metal nanoparticles becomes insufficient and the protective agent Since it is difficult to desorb or decompose (separate / combust) due to heat during firing, a large amount of organic residue remains in the electromagnetic shielding material after firing, and the residue is altered or deteriorated, resulting in a decrease in conductivity. This is because the production advantage of the low-temperature process cannot be utilized when the temperature exceeds 1, that is, the manufacturing cost increases and the productivity decreases. Furthermore, the firing time of the dispersion film printed on the substrate was limited to the range of 3 minutes to 1 hour because the sintering of the metal nanoparticles became insufficient and the firing of the protective agent in less than 3 minutes. Since it is difficult to desorb or decompose (separate / combust) due to the heat of the time, a large amount of organic residue remains in the baked electromagnetic wave shielding material, and this residue is altered or deteriorated to reduce the conductivity of the electrode. This is because, if the time is exceeded, the characteristics are not affected, but the manufacturing cost increases more than necessary and the productivity decreases.

上記電磁波遮蔽用組成物では、一次粒径５０〜２００ｎｍとサイズの比較的大きい金属ナノ粒子を多く含むため、金属ナノ粒子の比表面積が減少し、保護剤の占める割合が小さくなる。この結果、上記組成物を用いて電磁波遮蔽物を形成すると、上記保護剤中の有機分子が焼成時の熱により脱離し又は分解し、或いは離脱しかつ分解することにより、実質的に有機物を含有しない銀を主成分とする遮蔽物が得られる。   In the said electromagnetic wave shielding composition, since it contains many metal nanoparticles with a primary particle size of 50-200 nm and a comparatively large size, the specific surface area of a metal nanoparticle reduces and the ratio for which a protective agent accounts becomes small. As a result, when an electromagnetic wave shielding material is formed using the above composition, the organic molecules in the protective agent are desorbed or decomposed by the heat during firing, or are separated and decomposed to substantially contain organic matter. A shield mainly composed of silver is obtained.

このように、本発明の電磁波遮蔽物の形成方法では、量産性に優れた印刷法と大気中での熱処理という簡易な方法で電磁波遮蔽物を形成できる。また１３０℃といった低い温度による焼成プロセスでも十分な導電性が得られるため、使用する基材の選択肢が広がり、例えば、高分子フィルムを基材に用いることができる。更に、本発明の形成方法は、エッチングのような高分子フィルムにダメージを与える工程がないため、経年安定性に優れた電磁波遮蔽物を得ることができる。   Thus, according to the method for forming an electromagnetic wave shielding material of the present invention, the electromagnetic wave shielding material can be formed by a simple method of a printing method excellent in mass productivity and a heat treatment in the atmosphere. Moreover, since sufficient electroconductivity can be obtained even in a baking process at a low temperature such as 130 ° C., the choice of the substrate to be used is widened, and for example, a polymer film can be used as the substrate. Furthermore, since the forming method of the present invention does not include a step of damaging the polymer film such as etching, an electromagnetic wave shielding material having excellent aging stability can be obtained.

また、上記遮蔽物の形成された電磁波遮蔽性構造体を長年使用しても、有機物が変質又は劣化するということがなく、遮蔽物の導電率が高い状態に維持されるので、経年安定性に優れた電磁波遮蔽物を得ることができる。具体的には、上記遮蔽物を、温度を１００℃に保ちかつ湿度を５０％に保った恒温恒湿槽に１０００時間収容した後であっても、遮蔽物の導電性、即ち遮蔽物の体積抵抗率を２×１０^-5Ω・ｃｍ（２０×１０^-6Ω・ｃｍ）未満と極めて低い値に維持できる。このようにして形成された遮蔽物を用いた電磁波遮蔽性構造体は、長年使用しても高導電率を維持することができ、経年安定性に優れる。 In addition, even when the electromagnetic shielding structure having the shielding material is used for many years, the organic matter is not deteriorated or deteriorated, and the electrical conductivity of the shielding material is maintained high. An excellent electromagnetic shielding material can be obtained. Specifically, the conductivity of the shielding object, that is, the volume of the shielding object, even after the shielding object is stored for 1000 hours in a constant temperature and humidity chamber in which the temperature is kept at 100 ° C. and the humidity is kept at 50%. The resistivity can be maintained at a very low value of less than 2 × 10 ⁻⁵ Ω · cm (20 × 10 ⁻⁶ Ω · cm). The electromagnetic wave shielding structure using the shield formed as described above can maintain high conductivity even when used for many years, and is excellent in aging stability.

次に本発明の実施例を比較例とともに詳しく説明する。なお、実施例１〜１２はいずれも参考例である。
Next, examples of the present invention will be described in detail together with comparative examples. Examples 1 to 12 are all reference examples.

＜実施例１＞
先ず硝酸銀を脱イオン水に溶解して金属塩水溶液を調製した。一方、クエン酸ナトリウムを脱イオン水に溶解させて得られた濃度２６％のクエン酸ナトリウム水溶液に、温度３５℃の窒素ガス気流中で粒状の硫酸第一鉄を直接加えて溶解させ、クエン酸イオンと第一鉄イオンを３：２のモル比で含有する還元剤水溶液を調製した。次に上記窒素ガス気流を温度３５℃に保った状態で、マグネチックスターラーの撹拌子を１００ｒｐｍの回転速度で回転させて上記還元剤水溶液を撹拌しながら、この還元剤水溶液に上記金属塩水溶液を滴下して混合した。ここで、金属塩水溶液の添加量は還元剤水溶液の量の１／１０以下になるように、各溶液の濃度を調整することで、室温の金属塩水溶液を滴下しても反応温度が４０℃に保持されるようにした。また上記還元剤水溶液と金属塩水溶液との混合比は、還元剤として加えられる第１鉄イオンの当量が、金属イオンの当量の３倍となるように調整した。金属塩水溶液の滴下が終了した後、混合液の撹拌を更に１５分間続けて金属コロイドからなる分散液を得た。この分散液のｐＨは５．５であり、分散液中の金属粒子の化学量論的生成量は５ｇ／リットルであった。この得られた分散液を室温で放置し、沈降した金属ナノ粒子の凝集物をデカンテーションにより分離した。この分離物に脱イオン水を加えて分散体とし、限外ろ過により脱塩処理した後、更に引き続いてメタノールで置換洗浄して、金属（銀）の含有量を５０質量％にした。その後、遠心分離機を用いこの遠心分離機の遠心力を調整して粗粒子を分離することにより、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７０％含有するように調製した、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの範囲内の銀ナノ粒子の占める割合が７０％になるように調整した。調整した分散体にエチレングリコールを加え、エバポレーターによりメタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例１とした。なお、分散体中の銀ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤で化学修飾された。更に銀ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。なお、硫酸第一鉄中の鉄はメタノールによる置換洗浄時等に除去された。 <Example 1>
First, silver nitrate was dissolved in deionized water to prepare an aqueous metal salt solution. On the other hand, granular ferrous sulfate was directly added and dissolved in a 26% concentration sodium citrate aqueous solution obtained by dissolving sodium citrate in deionized water in a nitrogen gas stream at a temperature of 35 ° C. A reducing agent aqueous solution containing ions and ferrous ions in a molar ratio of 3: 2 was prepared. Next, with the nitrogen gas stream maintained at a temperature of 35 ° C., the magnetic salt stirrer is rotated at a rotational speed of 100 rpm to stir the reducing agent aqueous solution, and the metal salt aqueous solution is added to the reducing agent aqueous solution. Dropped and mixed. Here, by adjusting the concentration of each solution so that the amount of the metal salt aqueous solution added is 1/10 or less of the amount of the reducing agent aqueous solution, the reaction temperature is 40 ° C. even when the metal salt aqueous solution at room temperature is dropped. To be retained. The mixing ratio of the reducing agent aqueous solution and the metal salt aqueous solution was adjusted so that the equivalent of ferrous ions added as a reducing agent was three times the equivalent of metal ions. After the dropping of the aqueous metal salt solution was completed, the mixture was further stirred for 15 minutes to obtain a dispersion composed of metal colloid. The pH of this dispersion was 5.5, and the stoichiometric amount of metal particles in the dispersion was 5 g / liter. The obtained dispersion was allowed to stand at room temperature, and the aggregates of the precipitated metal nanoparticles were separated by decantation. Deionized water was added to the separated product to form a dispersion, which was desalted by ultrafiltration, and then further subjected to displacement washing with methanol to make the metal (silver) content 50 mass%. Thereafter, the centrifugal force of the centrifuge is adjusted using a centrifuge to separate coarse particles so that the silver nanoparticles contain 70% of silver nanoparticles having a primary particle size of 50 to 200 nm in number average. Adjustment was made so that the proportion of silver nanoparticles in the range of primary particle size of 50 to 200 nm with respect to 100% of all prepared silver nanoparticles was 70%. Ethylene glycol was added to the prepared dispersion, and methanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 1. The silver nanoparticles in the dispersion were chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying the silver nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O). In addition, iron in ferrous sulfate was removed at the time of displacement washing with methanol.

＜実施例２＞
実施例１と同様にして得られた分散液を室温で放置し、沈降した金属ナノ粒子の凝集物をデカンテーションにより分離した。この分離物に脱イオン水を加えて分散体とし、限外ろ過により脱塩処理した後、更に引き続いてエタノールで置換洗浄して、金属の含有量を５０質量％にした。その後、遠心分離機を用いこの遠心分離機の遠心力を調整して粗粒子を分離することにより、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように調製した、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。調整した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例２とした。なお、分散体中の銀ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤で化学修飾された。更に銀ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 2>
The dispersion obtained in the same manner as in Example 1 was allowed to stand at room temperature, and the aggregates of the precipitated metal nanoparticles were separated by decantation. Deionized water was added to this separated product to form a dispersion, which was desalted by ultrafiltration, and then further subjected to displacement washing with ethanol to make the metal content 50% by mass. Thereafter, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles so that the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 50 to 200 nm in number average. Adjustment was made so that the proportion of silver nanoparticles having a primary particle size of 50 to 200 nm with respect to 100% of all prepared silver nanoparticles was 75%. Ethylene glycol was added to the prepared dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 2. The silver nanoparticles in the dispersion were chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying the silver nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜参考例１＞
還元剤水溶液の調製時にクエン酸ナトリウムに替えてりんご酸ナトリウムを用いたこと以外は実施例１と同様にして得られた分散液を室温で放置し、沈降した金属ナノ粒子の凝集物をデカンテーションにより分離した。この分離物に脱イオン水を加えて分散体とし、限外ろ過により脱塩処理した後、更に引き続いてメタノールで置換洗浄して、金属の含有量を５０質量％にした。その後、遠心分離機を用いこの遠心分離機の遠心力を調整して粗粒子を分離することにより、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように調製した、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。調整した分散体にエチレングリコールを加え、エバポレーターによりメタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を参考例１とした。なお、分散体中の銀ナノ粒子は炭素骨格が炭素数２の有機分子主鎖の保護剤で化学修飾された。更に銀ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）及びカルボニル基（−Ｃ＝Ｏ）を含有した。 < Reference Example 1 >
The dispersion obtained in the same manner as in Example 1 except that sodium malate was used in place of sodium citrate when preparing the reducing agent aqueous solution was allowed to stand at room temperature, and the aggregates of the precipitated metal nanoparticles were decanted. Separated by. Deionized water was added to this separated product to form a dispersion, which was desalted by ultrafiltration, and then further subjected to displacement washing with methanol to make the metal content 50% by mass. Thereafter, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles so that the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 50 to 200 nm in number average. Adjustment was made so that the proportion of silver nanoparticles having a primary particle size of 50 to 200 nm with respect to 100% of all prepared silver nanoparticles was 75%. Ethylene glycol was added to the prepared dispersion, and methanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Reference Example 1 . The silver nanoparticles in the dispersion were chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 2 carbon skeletons. Furthermore, the protective agent chemically modifying the silver nanoparticles contained a hydroxyl group (—OH) and a carbonyl group (—C═O).

＜参考例２＞
還元剤水溶液の調製時にクエン酸ナトリウムに替えてグリコール酸ナトリウムを用いたこと以外は実施例１と同様にして得られた分散液を室温で放置し、沈降した金属ナノ粒子の凝集物をデカンテーションにより分離した。この分離物に脱イオン水を加えて分散体とし、限外ろ過により脱塩処理した後、更に引き続いてメタノールで置換洗浄して、金属の含有量を５０質量％にした。その後、遠心分離機を用いこの遠心分離機の遠心力を調整して粗粒子を分離することにより、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように調製した、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。調整した分散体にエチレングリコールを加え、エバポレーターによりメタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を参考例２とした。なお、分散体中の銀ナノ粒子は炭素骨格が炭素数１の有機分子主鎖の保護剤で化学修飾された。更に銀ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 < Reference Example 2 >
The dispersion obtained in the same manner as in Example 1 except that sodium glycolate was used instead of sodium citrate when preparing the reducing agent aqueous solution was allowed to stand at room temperature, and the aggregates of the precipitated metal nanoparticles were decanted. Separated by. Deionized water was added to this separated product to form a dispersion, which was desalted by ultrafiltration, and then further subjected to displacement washing with methanol to make the metal content 50% by mass. Thereafter, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles so that the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 50 to 200 nm in number average. Adjustment was made so that the proportion of silver nanoparticles having a primary particle size of 50 to 200 nm with respect to 100% of all prepared silver nanoparticles was 75%. Ethylene glycol was added to the prepared dispersion, and methanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Reference Example 2 . The silver nanoparticles in the dispersion were chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 1 carbon. Furthermore, the protective agent chemically modifying the silver nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例３＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を塩化金酸に替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、金ナノ粒子が一次粒径５０〜２００ｎｍの金ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての金ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの金ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が９５質量％、金ナノ粒子が５質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例３とした。なお、分散体中の銀ナノ粒子及び金ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及び金ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 3 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with chloroauric acid, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was used. The gold nanoparticles having a primary particle diameter of 50 to 200 nm were 75 in average number. The second dispersion is adjusted by a centrifuge so that the percentage of gold nanoparticles having a primary particle diameter of 50 to 200 nm is 75% with respect to 100% of all gold nanoparticles in terms of number average. Got. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 95% by mass and the gold nanoparticles were 5% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 3 . The silver nanoparticles and gold nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protecting agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and gold nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例４＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を塩化白金酸に替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、白金ナノ粒子が一次粒径５０〜２００ｎｍの白金ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての白金ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの白金ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が９５質量％、白金ナノ粒子が５質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例４とした。なお、分散体中の銀ナノ粒子及び白金ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及び白金ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）及びカルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 4 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with chloroplatinic acid, and the dispersion subjected to substitution cleaning with ethanol in the same manner as in Example 2 was used. The platinum nanoparticles with platinum nanoparticles having a primary particle size of 50 to 200 nm were 75 in average. The second dispersion is adjusted by a centrifuge so that the proportion of platinum nanoparticles having a primary particle diameter of 50 to 200 nm is 75% with respect to 100% of all platinum nanoparticles in terms of number average. Got. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 95% by mass and the platinum nanoparticles were 5% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 4 . The silver nanoparticles and platinum nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and platinum nanoparticles contained a hydroxyl group (—OH) and a carbonyl group (—C═O).

＜実施例５＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を硝酸パラジウムに替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、パラジウムナノ粒子が一次粒径５０〜２００ｎｍのパラジウムナノ粒子を数平均で７５％含有するように、即ち数平均で全てのパラジウムナノ粒子１００％に対する一次粒径５０〜２００ｎｍのパラジウムナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が７７質量％、パラジウムナノ粒子が２３質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例５とした。なお、分散体中の銀ナノ粒子及びパラジウムナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及びパラジウムナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）及びカルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 5 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with palladium nitrate, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was used. The palladium nanoparticles had a number average of 75% of palladium nanoparticles with a primary particle size of 50 to 200 nm. The second dispersion is adjusted by a centrifuge so that the proportion of palladium nanoparticles having a primary particle diameter of 50 to 200 nm is 75% with respect to 100% of all palladium nanoparticles in terms of number average. Obtained. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 77% by mass and the palladium nanoparticles were 23% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 5 . The silver nanoparticles and palladium nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and palladium nanoparticles contained a hydroxyl group (—OH) and a carbonyl group (—C═O).

＜実施例６＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を三塩化ルテニウムに替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、ルテニウムナノ粒子が一次粒径５０〜２００ｎｍのルテニウムナノ粒子を数平均で７５％含有するように、即ち数平均で全てのルテニウムナノ粒子１００％に対する一次粒径５０〜２００ｎｍのルテニウムナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が７６質量％、ルテニウムナノ粒子が２４質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例６とした。なお、分散体中の銀ナノ粒子及びルテニウムナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及びルテニウムナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 6 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with ruthenium trichloride, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was used. The second dispersion is adjusted by a centrifugal separator so that the ratio of the ruthenium nanoparticles having a primary particle diameter of 50 to 200 nm to 75% is 75%. Got. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 76% by mass and the ruthenium nanoparticles were 24% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 6 . The silver nanoparticles and ruthenium nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon skeletons. Furthermore, the protective agent chemically modifying silver nanoparticles and ruthenium nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例７＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を塩化ニッケルに替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、ニッケルナノ粒子が一次粒径５０〜２００ｎｍのニッケルナノ粒子を数平均で７５％含有するように、即ち数平均で全てのニッケルナノ粒子１００％に対する一次粒径５０〜２００ｎｍのニッケルナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が７６質量％、ニッケルナノ粒子が２４質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例７とした。なお、分散体中の銀ナノ粒子及びニッケルナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤で化学修飾された。更に銀ナノ粒子及びニッケルナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 7 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with nickel chloride, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was used. The nickel nanoparticles were nickel nanoparticles having a primary particle diameter of 50 to 200 nm and the number average was 75%. The second dispersion is adjusted by a centrifuge so that the proportion of nickel nanoparticles having a primary particle size of 50 to 200 nm is 75% with respect to 100% of all nickel nanoparticles in terms of number average. Obtained. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 76% by mass and the nickel nanoparticles were 24% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 7 . The silver nanoparticles and nickel nanoparticles in the dispersion were chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and nickel nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例８＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を硝酸第一銅に替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、銅ナノ粒子が一次粒径５０〜２００ｎｍの銅ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銅ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銅ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が７６質量％、銅ナノ粒子が２４質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例８とした。なお、分散体中の銀ナノ粒子及び銅ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及び銅ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 8 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with cuprous nitrate, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was compared with the number average of copper nanoparticles having a primary particle diameter of 50 to 200 nm. The second dispersion is adjusted by a centrifuge so that it contains 75%, that is, the proportion of copper nanoparticles having a primary particle diameter of 50 to 200 nm is 75% with respect to 100% of all copper nanoparticles in number average. Got the body. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 76% by mass and the copper nanoparticles were 24% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 8 . The silver nanoparticles and copper nanoparticles in the dispersion were chemically modified with a protective agent having an organic molecular main chain having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and copper nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例９＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を二塩化錫に替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、錫ナノ粒子が一次粒径５０〜２００ｎｍの錫ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての錫ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの錫ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が７６質量％、錫ナノ粒子が２４質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例９とした。なお、分散体中の銀ナノ粒子及び錫ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及び錫ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 9 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with tin dichloride, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was used. The tin nanoparticles with a primary particle size of 50 to 200 nm were 75 in average number. The second dispersion is adjusted by a centrifuge so that the proportion of tin nanoparticles having a primary particle diameter of 50 to 200 nm is 75% with respect to 100% of all tin nanoparticles on a number average basis. Got. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 76% by mass and the tin nanoparticles were 24% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 9 . The silver nanoparticles and tin nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protecting agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying the silver nanoparticles and tin nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例１０＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を硝酸インジウムに替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、インジウムナノ粒子が一次粒径５０〜２００ｎｍのインジウムナノ粒子を数平均で７５％含有するように、即ち数平均で全てのインジウムナノ粒子１００％に対する一次粒径５０〜２００ｎｍのインジウムナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が８０質量％、インジウムナノ粒子が２０質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例１０とした。なお、分散体中の銀ナノ粒子及びインジウムナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及びインジウムナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 10 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with indium nitrate, and the dispersion subjected to substitution cleaning with ethanol in the same manner as in Example 2 was used. The indium nanoparticles with an indium nanoparticle primary particle size of 50 to 200 nm were 75% in average The second dispersion is adjusted by a centrifuge so that the proportion of indium nanoparticles having a primary particle diameter of 50 to 200 nm is 75% with respect to 100% of all indium nanoparticles in terms of number average. Obtained. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 80% by mass and the indium nanoparticles were 20% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 10 . The silver nanoparticles and indium nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and indium nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例１１＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を塩化亜鉛に替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、亜鉛ナノ粒子が一次粒径５０〜２００ｎｍの亜鉛ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての亜鉛ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの亜鉛ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が８０質量％、亜鉛ナノ粒子が２０質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例１１とした。なお、分散体中の銀ナノ粒子及び亜鉛ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及び亜鉛ナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 11 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with zinc chloride, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was used. The zinc nanoparticles with a primary particle diameter of 50 to 200 nm were 75% in average number. The second dispersion is adjusted by a centrifuge so that the proportion of zinc nanoparticles having a primary particle diameter of 50 to 200 nm is 75% with respect to 100% of all zinc nanoparticles in terms of number average. Obtained. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 80% by mass and the zinc nanoparticles were 20% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 11 . The silver nanoparticles and zinc nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and zinc nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜実施例１２＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を硫酸クロムに替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、クロムナノ粒子が一次粒径５０〜２００ｎｍのクロムナノ粒子を数平均で７５％含有するように、即ち数平均で全てのクロムナノ粒子１００％に対する一次粒径５０〜２００ｎｍのクロムナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が９５質量％、クロムナノ粒子が５質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例１２とした。なお、分散体中の銀ナノ粒子及びクロムナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及びクロムナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 12 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with chromium sulfate, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 contained 75% of chromium nanoparticles with a primary particle size of 50 to 200 nm in terms of number average. In other words, the second dispersion was obtained by adjusting with a centrifuge so that the ratio of chromium nanoparticles having a primary particle diameter of 50 to 200 nm to 75% of all chromium nanoparticles 100% in terms of number average was 75%. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 95% by mass and the chromium nanoparticles were 5% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 12 . The silver nanoparticles and chromium nanoparticles in the dispersion were chemically modified with an organic molecular main chain protecting agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and chromium nanoparticles did not contain a hydroxyl group (—OH), but contained a carbonyl group (—C═O).

＜実施例１３＞
実施例２と同様にしてエタノールで置換洗浄された分散体を、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第１分散体を得た。一方、実施例２の硝酸銀を硫酸マンガンに替え、実施例２と同様にしてエタノールで置換洗浄された分散体を、マンガンナノ粒子が一次粒径５０〜２００ｎｍのマンガンナノ粒子を数平均で７５％含有するように、即ち数平均で全てのマンガンナノ粒子１００％に対する一次粒径５０〜２００ｎｍのマンガンナノ粒子の占める割合が７５％になるように、遠心分離機により調整して第２分散体を得た。次に第１分散体と第２分散体とを銀ナノ粒子が９５質量％、マンガンナノ粒子が５質量％となるように混合した。混合した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を実施例１３とした。なお、分散体中の銀ナノ粒子及びマンガンナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤でそれぞれ化学修飾された。更に銀ナノ粒子及びマンガンナノ粒子を化学修飾している保護剤は水酸基（−ＯＨ）を含有しなかったけれども、カルボニル基（−Ｃ＝Ｏ）を含有した。 <Example 13 >
The dispersion substituted and washed with ethanol in the same manner as in Example 2 was prepared so that the silver nanoparticles contained 75% of silver nanoparticles having a primary particle diameter of 50 to 200 nm in number average, that is, all silver nanoparticles in number average. The first dispersion was obtained by adjusting with a centrifuge so that the proportion of silver nanoparticles having a primary particle diameter of 50 to 200 nm with respect to 100% of the particles was 75%. On the other hand, the silver nitrate of Example 2 was replaced with manganese sulfate, and the dispersion subjected to substitution washing with ethanol in the same manner as in Example 2 was used. The manganese nanoparticles having a primary particle diameter of 50 to 200 nm were 75% in terms of number average. The second dispersion is adjusted by a centrifuge so that the proportion of manganese nanoparticles having a primary particle size of 50 to 200 nm is 75% with respect to 100% of all manganese nanoparticles in terms of number average. Obtained. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 95% by mass and the manganese nanoparticles were 5% by mass. Ethylene glycol was added to the mixed dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Example 13 . The silver nanoparticles and manganese nanoparticles in the dispersion were each chemically modified with an organic molecular main chain protecting agent having a carbon skeleton of 3 carbon atoms. Furthermore, the protective agent chemically modifying silver nanoparticles and manganese nanoparticles did not contain a hydroxyl group (—OH) but contained a carbonyl group (—C═O).

＜比較例１＞
実施例１と同様にして得られた分散液を室温で放置し、沈降した金属ナノ粒子の凝集物をデカンテーションにより分離した。この分離物に脱イオン水を加えて分散体とし、限外ろ過により脱塩処理した後、更に引き続いてメタノールで置換洗浄して、金属の含有量を５０質量％にした。その後、遠心分離機を用いこの遠心分離機の遠心力を調整して粗粒子を分離することにより、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で５０％含有するように調製した、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が５０％になるように調整した。調整した分散体にエチレングリコールを加え、エバポレーターによりメタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を比較例１とした。なお、分散体中の銀ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤で化学修飾された。 <Comparative Example 1>
The dispersion obtained in the same manner as in Example 1 was allowed to stand at room temperature, and the aggregates of the precipitated metal nanoparticles were separated by decantation. Deionized water was added to this separated product to form a dispersion, which was desalted by ultrafiltration, and then further subjected to displacement washing with methanol to make the metal content 50% by mass. Thereafter, the centrifugal force of the centrifuge is adjusted using a centrifuge to separate coarse particles so that the silver nanoparticles contain 50% of silver nanoparticles having a primary particle size of 50 to 200 nm in number average. The ratio of the prepared silver nanoparticles having a primary particle diameter of 50 to 200 nm to the total silver nanoparticles of 100% was adjusted to 50%. Ethylene glycol was added to the prepared dispersion, and methanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Comparative Example 1. The silver nanoparticles in the dispersion were chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 3 carbon atoms.

＜比較例２＞
還元剤水溶液の調製時にクエン酸ナトリウムに替えてメバロン酸ナトリウムを用いたこと以外は実施例１と同様にして得られた分散液を室温で放置し、沈降した金属ナノ粒子の凝集物をデカンテーションにより分離した。この分離物に脱イオン水を加えて分散体とし、限外ろ過により脱塩処理した後、更に引き続いてエタノールで置換洗浄して、金属の含有量を５０質量％にした。その後、遠心分離機を用いこの遠心分離機の遠心力を調整して粗粒子を分離することにより、銀ナノ粒子が一次粒径５０〜２００ｎｍの銀ナノ粒子を数平均で７５％含有するように調製した、即ち数平均で全ての銀ナノ粒子１００％に対する一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。調整した分散体にエチレングリコールを加え、エバポレーターによりエタノールを留去することにより、金属（銀）７０質量％、エチレングリコール３０質量％からなるペースト状の分散体を得た。この分散体を比較例２とした。なお、分散体中の銀ナノ粒子は炭素骨格が炭素数４の有機分子主鎖の保護剤で化学修飾された。 <Comparative Example 2>
The dispersion obtained in the same manner as in Example 1 except that sodium mevalonate was used instead of sodium citrate when preparing the reducing agent aqueous solution was allowed to stand at room temperature, and the aggregates of the precipitated metal nanoparticles were decanted. Separated by. Deionized water was added to this separated product to form a dispersion, which was desalted by ultrafiltration, and then further subjected to displacement washing with ethanol to make the metal content 50% by mass. Thereafter, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles so that the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 50 to 200 nm in number average. Adjustment was made so that the proportion of silver nanoparticles having a primary particle size of 50 to 200 nm with respect to 100% of all prepared silver nanoparticles was 75%. Ethylene glycol was added to the prepared dispersion, and ethanol was distilled off by an evaporator to obtain a paste-like dispersion composed of 70% by mass of metal (silver) and 30% by mass of ethylene glycol. This dispersion was designated as Comparative Example 2. The silver nanoparticles in the dispersion were chemically modified with an organic molecular main chain protective agent having a carbon skeleton of 4 carbon atoms.

＜比較試験１及び評価＞
基材として表面がＰＥＴからなる基板を用意し、実施例１〜１３、参考例１〜２及び比較例１〜２の分散体を基板上に、焼成後の膜厚が４μｍとなるようにバーコーターにより塗布した。続いて、塗膜を有する基板を大気中、次の表１に示される温度で焼成することにより、基板上に金属膜を形成した。これらの金属膜を形成した基板について、耐候性試験を行う前に、各基板に形成された金属膜の導電性を測定するとともに、耐候性試験を行った後に、各基板に形成された金属膜の導電性を測定した。その結果を、表１に示す。 <Comparative test 1 and evaluation>
Prepare a substrate made of PET as the base material, and place the dispersions of Examples 1 to 13, Reference Examples 1 and 2 and Comparative Examples 1 and 2 on the substrate so that the film thickness after firing is 4 μm. It was applied by a coater. Then, the metal film was formed on the board | substrate by baking the board | substrate which has a coating film in air | atmosphere at the temperature shown by following Table 1. FIG. About the board | substrate which formed these metal films, before performing a weather resistance test, while measuring the electroconductivity of the metal film formed in each board | substrate, after performing a weather resistance test, the metal film formed in each board | substrate The conductivity of was measured. The results are shown in Table 1.

なお、耐候性試験は、金属膜の形成された基板を、温度を１００℃に保ち湿度を５０％に保った恒温恒湿槽に１０００時間収容することにより行った。   In addition, the weather resistance test was performed by accommodating the board | substrate with which the metal film was formed in the constant temperature and humidity chamber which maintained the temperature at 100 degreeC, and maintained the humidity at 50% for 1000 hours.

なお、表１中における、金属ナノ粒子の一次粒径は、ＦＥ−ＴＥＭ（電界放出型透過電子顕微鏡：日本電子社製）を用いて計測し、一次粒径５０〜２００ｎｍの銀ナノ粒子の占める割合は、上記ＦＥ−ＴＥＭを用いて撮影した金属ナノ粒子の一次粒径の写真から画像処理により粒子径の数を計測して評価した。   In Table 1, the primary particle size of the metal nanoparticles is measured using FE-TEM (Field Emission Transmission Electron Microscope: manufactured by JEOL Ltd.) and occupied by silver nanoparticles having a primary particle size of 50 to 200 nm. The ratio was evaluated by measuring the number of particle diameters by image processing from a photograph of the primary particle diameter of the metal nanoparticles photographed using the FE-TEM.

また導電性は、四端子法により測定し算出した体積抵抗率（Ω・ｃｍ）として求めた。具体的には、金属膜の体積抵抗率は、先ず焼成後の金属膜の厚さをＳＥＭ（電子顕微鏡Ｓ８００：日立製作所社製）を用いて金属膜断面から金属膜の厚さを直接計測し、次に四端子法による比抵抗測定器（ロレスタ：三菱化学社製）を用い、この測定器に上記実測した金属膜の厚さを入力して測定した。   The conductivity was determined as a volume resistivity (Ω · cm) measured and calculated by the four probe method. Specifically, the volume resistivity of the metal film is obtained by first measuring the thickness of the metal film after firing directly from the cross section of the metal film using an SEM (Electron Microscope S800: manufactured by Hitachi, Ltd.). Then, using a specific resistance measuring device (Loresta: manufactured by Mitsubishi Chemical Corporation) by the four-terminal method, the measured thickness of the metal film was input to this measuring device and measured.

更に水酸基（−ＯＨ）、カルボニル基（−Ｃ＝Ｏ）の有無は、ＸＰＳ（Quantum 2000：PHI社製のＸ線光電子分光分析装置）、ＴＯＦ−ＳＩＭＳ（TOF-SIMS IV：ION-TOF社製の飛行時間型二次イオン質量分析装置）、ＦＴＩＲ（NEXUS 670：Nicolet社製のフーリエ変換赤外分光光度計）及びＴＰＤ−ＭＳ（5973N：Agilent社製の昇温熱脱離・質量分析装置）を用いた機器分析を併用して存在を確認した。   Furthermore, the presence or absence of a hydroxyl group (—OH) and a carbonyl group (—C═O) is determined by XPS (Quantum 2000: X-ray photoelectron spectrometer manufactured by PHI), TOF-SIMS (TOF-SIMS IV: manufactured by ION-TOF). Time-of-flight secondary ion mass spectrometer), FTIR (NEXUS 670: Fourier transform infrared spectrophotometer manufactured by Nicolet) and TPD-MS (5973N: temperature-programmed thermal desorption / mass spectrometer manufactured by Agilent) Presence was confirmed using the instrumental analysis used together.

表１には、実施例１〜１３、参考例１〜２及び比較例１，２の分散体における一次粒径５０〜２００ｎｍの金属ナノ粒子の占める割合と、有機分子主鎖の炭素数と、異種金属（銀以外の金属）の種類及び含有率（銀と銀以外の金属の合計を１００質量％としたときの異種金属の含有率）とを併せて示した。表１の耐候性の欄において、『良好』とは、体積抵抗率が２０×１０^-6Ω・ｃｍ未満であった場合を示し、『不良』とは、体積抵抗率が２０×１０^-6Ω・ｃｍ以上であった場合を示す。
In Table 1, the ratio of the metal nanoparticles having a primary particle size of 50 to 200 nm in the dispersions of Examples 1 to 13, Reference Examples 1 and 2, and Comparative Examples 1 and 2, the number of carbon atoms in the organic molecular main chain, The types and contents of different metals (metals other than silver) (contents of different metals when the total of silver and metals other than silver is 100% by mass) are also shown. In the weather resistance column of Table 1, “good” indicates that the volume resistivity is less than 20 × 10 ⁻⁶ Ω · cm, and “bad” indicates that the volume resistivity is 20 × 10 ^−6. The case of Ω · cm or more is shown.

表１から明らかなように、比較例１では、焼成直後、即ち耐候性試験前の金属膜の体積抵抗率は１３×１０^-6Ω・ｃｍであり、初期特性はほぼ満足するものであったけれども、耐候性試験を行った後は、金属膜の体積抵抗率が低下（経年劣化）して不良となった。また、比較例２では、耐候性試験前の金属膜の体積抵抗率において不十分であり、耐候性試験後の金属膜の体積抵抗率も不良となった。これらに対し、実施例では、耐候性試験前及び耐候性試験後のいずれであっても、金属膜の体積抵抗率が２０×１０^-6Ω・ｃｍ未満であり、耐候性試験前の初期特性も耐候性も十分に満足するものとなった。

As is apparent from Table 1, in Comparative Example 1, the volume resistivity of the metal film immediately after firing, that is, before the weather resistance test was 13 × 10 ⁻⁶ Ω · cm, and the initial characteristics were almost satisfactory. However, after the weather resistance test, the volume resistivity of the metal film decreased (deteriorated over time) and became defective. In Comparative Example 2, the volume resistivity of the metal film before the weather resistance test was insufficient, and the volume resistivity of the metal film after the weather resistance test was poor. On the other hand, in the examples, the volume resistivity of the metal film is less than 20 × 10 ⁻⁶ Ω · cm both before and after the weather resistance test, and the initial characteristics before the weather resistance test. The weather resistance was sufficiently satisfactory.

なお、この比較試験における評価は、金属塗膜を簡便に塗工するためにバーコーターを用いたが、実用上は、金属ナノ粒子分散液のレオロジー特性をインクジェット印刷法やスクリーン印刷法、グラビア印刷法といった各種印刷法に適したものに調整した上で、各種印刷法を適用すればよく、上記種類の印刷法によっても同様の評価が得られることを確認している。   In this comparative test, a bar coater was used to simply apply a metal coating. However, in practice, the rheological properties of the metal nanoparticle dispersion were determined by inkjet printing, screen printing, and gravure printing. It is confirmed that various printing methods may be applied after adjusting to those suitable for various printing methods such as the above method, and it is confirmed that the same evaluation can be obtained by the above-mentioned types of printing methods.

＜比較試験２＞
基材として表面がＰＥＴからなる基板を３枚用意し、実施例２の分散体を基板上に、焼成後の膜厚が１μｍとなるようにバーコーターにより塗布した。続いて、塗膜を有する基板を大気中、次の表２に示される温度（１５０℃、１３０℃、１２０℃）でそれぞれ焼成することにより、基板上に金属膜を形成した。これらの金属膜を形成した基板について、耐候性試験を行う前に、各基板に形成された金属膜の導電性を測定するとともに、耐候性試験を行った後に、各基板に形成された金属膜の導電性を測定した。なお、耐候性試験及び導電性測定は、上記比較試験１と同様の方法により行った。その結果を、表２に示す。 <Comparison test 2>
Three substrates having a surface of PET as a base material were prepared, and the dispersion of Example 2 was applied onto the substrate with a bar coater so that the film thickness after firing was 1 μm. Then, the board | substrate which has a coating film was each baked in the temperature (150 degreeC, 130 degreeC, 120 degreeC) shown by following Table 2 in air | atmosphere, and the metal film was formed on the board | substrate. About the board | substrate which formed these metal films, before performing a weather resistance test, while measuring the electroconductivity of the metal film formed in each board | substrate, after performing a weather resistance test, the metal film formed in each board | substrate The conductivity of was measured. The weather resistance test and the conductivity measurement were performed in the same manner as in the comparative test 1. The results are shown in Table 2.

表２より明らかなように、焼成温度が下がるにつれて、焼成直後、即ち耐候性試験前の金属膜の体積抵抗率が高くなる傾向が見られた。そして、１２０℃での焼成では、極端に体積抵抗率が高くなることが確認された。これは１２０℃と低温での焼成では、金属ナノ粒子同士の焼結が不十分になったこと、焼成後の電磁波遮蔽物内に有機残渣が多く残り、この残渣が変質又は劣化して導電性が低下してしまったものと考えられる。

As is apparent from Table 2, as the firing temperature decreased, the volume resistivity of the metal film immediately after firing, that is, before the weather resistance test tended to increase. And it was confirmed that the volume resistivity becomes extremely high in the baking at 120 ° C. This is because firing at 120 ° C. and low temperature resulted in insufficient sintering of the metal nanoparticles, and many organic residues remained in the electromagnetic shielding material after firing, and this residue was altered or deteriorated to become conductive. Seems to have fallen.

また、１２０℃での焼成膜は、耐候性試験を行った後は、金属膜の体積抵抗率が低下（経年劣化）して不良となった。このことから、本発明の電磁波遮蔽用組成物を用いて電磁波遮蔽物を形成する場合、１３０℃以上の焼成温度が必要であることが判った。   Moreover, after the weather resistance test, the fired film at 120 ° C. became defective due to a decrease in volume resistivity (aging deterioration) of the metal film. From this, it was found that when an electromagnetic wave shielding material is formed using the electromagnetic wave shielding composition of the present invention, a baking temperature of 130 ° C. or higher is necessary.

Claims (8)

金属ナノ粒子が分散媒に分散した電磁波遮蔽用組成物であって、
前記金属ナノ粒子が７５質量％以上の銀ナノ粒子と、銀ナノ粒子以外の金属ナノ粒子を含有し、
前記銀ナノ粒子以外の金属ナノ粒子がＭｎの金属ナノ粒子であり、
前記金属ナノ粒子は炭素骨格が炭素数３の有機分子主鎖の保護剤で化学修飾され、
前記金属ナノ粒子が一次粒径５０〜２００ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上含有し、
前記分散媒がエチレングリコールを含むことを特徴とする電磁波遮蔽用組成物。 An electromagnetic shielding composition in which metal nanoparticles are dispersed in a dispersion medium,
The metal nanoparticles contain 75% by mass or more of silver nanoparticles and metal nanoparticles other than silver nanoparticles,
Metal nanoparticles other than the silver nanoparticles are Mn metal nanoparticles,
The metal nanoparticles are chemically modified with a protective agent of an organic molecular main chain having a carbon skeleton of 3 carbon atoms,
The metal nanoparticles contain a metal nanoparticle having a primary particle size of 50 to 200 nm in a number average of 70% or more,
The electromagnetic wave shielding composition, wherein the dispersion medium contains ethylene glycol. 前記金属ナノ粒子を化学修飾する前記保護剤がカルボニル基又は水酸基のいずれか一方又は双方を含む請求項１記載の電磁波遮蔽用組成物。   The electromagnetic shielding composition according to claim 1, wherein the protective agent that chemically modifies the metal nanoparticles includes one or both of a carbonyl group and a hydroxyl group. 前記銀ナノ粒子以外の金属ナノ粒子を０．０２質量％以上かつ２５質量％未満含有する請求項１又は２記載の電磁波遮蔽用組成物。   3. The electromagnetic wave shielding composition according to claim 1, comprising 0.02% by mass or more and less than 25% by mass of metal nanoparticles other than the silver nanoparticles. 請求項１ないし３いずれか１項に記載の電磁波遮蔽用組成物を製造する方法であって、
硝酸銀を水に溶解して金属塩水溶液を調製する工程と、
クエン酸ナトリウム水溶液に硫酸第一鉄を加えて溶解させることにより還元剤水溶液を調製する工程と、
前記還元剤水溶液に前記金属塩水溶液を滴下して混合、攪拌することにより金属コロイドからなる分散液を調製する工程と、
前記分散液を室温で放置し、沈降した金属ナノ粒子の凝集物を分離した後、得られた分離物に水を加えて分散体とする工程と
を含む電磁波遮蔽用組成物の製造方法。 A method for producing the electromagnetic wave shielding composition according to any one of claims 1 to 3,
Preparing a metal salt aqueous solution by dissolving silver nitrate in water;
Preparing a reducing agent aqueous solution by adding and dissolving ferrous sulfate in an aqueous sodium citrate solution;
Dropping the metal salt aqueous solution into the reducing agent aqueous solution and mixing and stirring to prepare a dispersion composed of metal colloid; and
The dispersion liquid is allowed to stand at room temperature to separate agglomerated metal nanoparticle aggregates, and then a water is added to the obtained separated substance to form a dispersion. 前記還元剤水溶液に前記金属塩水溶液を滴下して混合、攪拌する際の反応温度を３０〜６０℃、攪拌時間を１０〜３００分間とし、
前記分散体とする工程の後、前記分散体を限外ろ過により脱塩処理し、更に水と相溶する有機溶媒で置換洗浄する工程とを含む請求項４記載の電磁波遮蔽用組成物の製造方法。 The metal salt aqueous solution is dropped into the reducing agent aqueous solution and mixed, and the reaction temperature when stirring is 30 to 60 ° C., the stirring time is 10 to 300 minutes,
The process for producing an electromagnetic wave shielding composition according to claim 4, further comprising a step of desalting the dispersion by ultrafiltration after the step of forming the dispersion, and further performing substitution washing with an organic solvent compatible with water. Method. 請求項１ないし３いずれか１項に記載の電磁波遮蔽用組成物を基材上に印刷する工程と、
前記上面に印刷された基材を１３０〜４００℃で焼成する工程と
を含む電磁波遮蔽物の形成方法。 Printing the electromagnetic shielding composition according to any one of claims 1 to 3 on a substrate;
A step of firing the substrate printed on the upper surface at 130 to 400 ° C. 基材が高分子材料からなる基板又は高分子材料を含む２層以上の積層体である請求項６記載の電磁波遮蔽物の形成方法。   The method for forming an electromagnetic wave shielding object according to claim 6, wherein the substrate is a substrate made of a polymer material or a laminate of two or more layers containing the polymer material. 印刷方法がインクジェット印刷法、ディスペンサコーティング法、スプレーコーティング法、スクリーン印刷法、グラビア印刷法、凸版印刷法、フレキソ印刷法又はオフセット印刷法のいずれかである請求項６又は７記載の電磁波遮蔽物の形成方法。   The electromagnetic wave shielding material according to claim 6 or 7, wherein the printing method is any one of an inkjet printing method, a dispenser coating method, a spray coating method, a screen printing method, a gravure printing method, a relief printing method, a flexographic printing method, and an offset printing method. Forming method.