JP5326647B2

JP5326647B2 - Method for producing composition for forming electrode of solar cell

Info

Publication number: JP5326647B2
Application number: JP2009040645A
Authority: JP
Inventors: 佳明高田; 和彦山崎; 年治林
Original assignee: Mitsubishi Materials Corp
Current assignee: Mitsubishi Materials Corp
Priority date: 2009-02-24
Filing date: 2009-02-24
Publication date: 2013-10-30
Anticipated expiration: 2029-02-24
Also published as: JP2010199196A

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for forming an electrode for solar cell, which can provide an electrode excellent in aging stability, the electrode capable of maintain high conductivity and high reflectance even after a long time use. <P>SOLUTION: The composition for forming an electrode for solar cell is configured by dispersing metal nanoparticles in a dispersion medium. The metal nanoparticles contain not less than 75 mass% silver nanoparticles. The metal nanoparticles are chemically modified with a protective agent whose carbon skeleton comprises an organic molecule principal chain having 1-3 carbons. Further, the metal nanoparticles contain metal nanoparticles having a primary particle diameter in a range of 10-50 nm, in a proportion of not less than 70% by number on the average. The dispersion medium is any one of 1,2-propanediol, ethylene glycol, dimethylsulfoxide, and N-methyl formamide. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、太陽電池の電極を形成するための組成物の製造方法に関するものである。
The present invention relates to a manufacturing method of the composition for forming an electrode of a solar cell.

従来、この種の電極の形成方法として、０．０３μｍ以下の粒径の金属超微粒子を１００〜２００程度の低分子量の有機溶媒に分散させた溶液を光電変換半導体層に塗布・焼成することにより下層電極層を形成し、金属超微粒子の含有質量濃度が下層電極層の形成に用いた溶液と同じか或いは下層電極層の形成に用いた溶液より高い濃度の溶液を光電変換半導体層に塗布・焼成することにより上層電極層を形成する太陽電池の金属電極形成方法が開示されている（例えば、特許文献１参照。）。この金属電極形成方法では、金属超微粒子を分散させかつ粘度を１００００ｃｐｓ程度に調整した溶液をスクリーン印刷法等により光電変換半導体層に塗布した後に、１００〜２５０℃、好ましくは２５０℃の温度に３０分以上保持して焼成することにより、金属電極（下層電極層又は上層電極層）を形成する。 Conventionally, as a method for forming this type of electrode, a solution obtained by dispersing ultrafine metal particles having a particle size of 0.03 μm or less in an organic solvent having a low molecular weight of about 100 to 200 is applied to a photoelectric conversion semiconductor layer and fired. A lower electrode layer is formed, and a solution having a concentration of the ultrafine metal particles equal to or higher than that used for forming the lower electrode layer is applied to the photoelectric conversion semiconductor layer. A method for forming a metal electrode of a solar cell that forms an upper electrode layer by firing is disclosed (for example, see Patent Document 1). In this metal electrode forming method, a solution in which ultrafine metal particles are dispersed and the viscosity is adjusted to about 10,000 cps is applied to the photoelectric conversion semiconductor layer by a screen printing method or the like, and then the temperature is set to 100 to 250 ° C., preferably 250 ° C. A metal electrode (lower electrode layer or upper electrode layer) is formed by holding and baking for at least a minute.

このように構成された太陽電池の金属電極形成方法では、金属超微粒子を有機溶媒に分散させた溶液を光電変換半導体層に塗布した後に、１００〜２５０℃の低温で焼結することにより、高真空プロセスを用いずに、高い反射率及び導電率を有しかつ大きな面積の金属電極を得られるようになっている。 In the method for forming a metal electrode of a solar cell configured in this way, after applying a solution in which metal ultrafine particles are dispersed in an organic solvent to a photoelectric conversion semiconductor layer, sintering is performed at a low temperature of 100 to 250 ° C. Without using a vacuum process, a metal electrode having a high reflectance and conductivity and a large area can be obtained.

特許第３２８７７５４号（請求項１、段落［００２４］、段落［００３５］）Japanese Patent No. 3287754 (claim 1, paragraph [0024], paragraph [0035])

上記従来の特許文献１に示された太陽電池の金属電極形成方法では、焼成後の金属電極中の金属超微粒子を安定化させるために、所定の導電性を確保しながら金属超微粒子を１００〜２００程度の低分子量の有機物で保護する必要がある。一方、有機溶媒に分散させた金属超微粒子を低温で焼結化させるために、この金属超微粒子のサイズを小さくすると、金属超微粒子の比表面積が増大し、上記有機物の占める割合が大きくなる。このため、上記従来の特許文献１に示された太陽電池の金属電極形成方法では、有機溶媒に分散させた金属超微粒子の低温焼結化は、上記有機物を熱により脱離、或いは分解（分離・燃焼）させなければ実現できず、特に有機溶媒に分散させた金属超微粒子を２２０℃以下で焼成して得られた金属電極について耐候性試験を行うと、具体的には、温度を１００℃に保ちかつ湿度を５０％に保った恒温恒湿槽に金属電極を１０００時間収容すると、上記有機物が変質又は劣化して、導電性及び反射率が低下してしまう問題点があった。 In the conventional method for forming a metal electrode of a solar cell shown in Patent Document 1, in order to stabilize the metal ultrafine particles in the fired metal electrode, the metal ultrafine particles are added in an amount of 100 to 100 while ensuring predetermined conductivity. It is necessary to protect with an organic substance having a low molecular weight of about 200. On the other hand, if the size of the metal ultrafine particles is reduced in order to sinter the metal ultrafine particles dispersed in the organic solvent at a low temperature, the specific surface area of the metal ultrafine particles increases and the proportion of the organic matter increases. For this reason, in the conventional metal electrode forming method for solar cells shown in Patent Document 1, low-temperature sintering of metal ultrafine particles dispersed in an organic solvent is performed by desorbing or decomposing (separating) the organic matter by heat. If the weather resistance test is performed on a metal electrode obtained by firing metal ultrafine particles dispersed in an organic solvent at 220 ° C. or lower, specifically, the temperature is set to 100 ° C. When the metal electrode is housed in a constant temperature and humidity chamber maintained at 50% and humidity of 50% for 1000 hours, the organic matter is altered or deteriorated, resulting in a decrease in conductivity and reflectance.

本発明の目的は、長年使用しても高導電率及び高反射率を維持することができ、経年安定性に優れた電極を得ることができる、太陽電池の電極形成用組成物の製造方法を提供することにある。
An object of the present invention, even when used for many years can maintain a high conductivity and a high reflectance, it is possible to obtain an excellent electrode aging stability, a manufacturing method of an electrode forming composition for a solar cell It is to provide.

この本発明の第１の観点に記載された組成物では、一次粒径１０〜５０ｎｍ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、保護剤の占める割合が小さくなるため、この組成物を用いて太陽電池の電極を形成すると、上記保護剤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電極が得られる。 In the composition described in the first aspect of the present invention, since the metal nanoparticle having a primary particle size of 10 to 50 nm and a relatively large size is contained in a large amount, the specific surface area of the metal nanoparticle is reduced, and the protective agent occupies it. When the composition of the composition is used to form a solar cell electrode, the protective agent is desorbed or decomposed by heat during firing, or is separated and decomposed to substantially contain organic matter. An electrode mainly composed of silver is obtained.

本発明の第１の観点は、濃度１０〜４０％のクエン酸ナトリウム水溶液に不活性ガスの気流中で粒状又は粉状の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、不活性ガスの気流中に前記還元剤水溶液を撹拌しながら硝酸銀水溶液を前記還元剤水溶液に、前記硝酸銀水溶液の添加量は前記還元剤水溶液の量の１／１０以下になるように滴下して混合する工程と、前記混合液を１０〜３００分間撹拌して金属コロイドからなる分散液を調製する工程と、前記金属コロイドからなる分散液を室温で放置して沈降した金属ナノ粒子の凝集体を前記分散液から分離する工程と、前記分離物に水を加えて分散体とする工程と、前記分散体を限外ろ過により脱塩処理して得られた粗粒子を分離することにより一次粒径１０〜５０ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上含有する金属ナノ粒子分散液を得る工程と、前記金属ナノ粒子分散液を１，２−プロパンジオール、ジメチルスホキシド又はＮ−メチルホルムアミドのいずれかで置換洗浄して太陽電池の電極形成用組成物を得る工程とを含み、前記クエン酸ナトリウム水溶液は、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ものであり、金属ナノ粒子が分散媒に分散され、金属ナノ粒子が７５質量％以上の銀ナノ粒子と０．０２質量％以上かつ２５質量％未満のＡｕ、Ｐｔ、Ｐｄ、Ｒｕ、Ｎｉ、Ｃｕ、Ｓｎ、Ｉｎ、Ｚｎ、Ｆｅ、Ｃｒ又はＭｎのナノ粒子を含有し、前記金属ナノ粒子は炭素骨格が炭素数１〜３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１０〜５０ｎｍ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１，２−プロパンジオール、ジメチルスルホキシド又はＮ−メチルホルムアミドのいずれかであり、金属含有量が２．５〜９５質量％の範囲にあることを特徴とする太陽電池の電極形成用組成物の製造方法である。
The first aspect of the present invention is to prepare a reducing agent aqueous solution by dissolving by adding concentration 10-40% of granular or powdery ferrous sulfate aqueous sodium citrate solution in a stream of inert gas Adding a silver nitrate aqueous solution to the reducing agent aqueous solution while stirring the reducing agent aqueous solution in an inert gas stream so that the addition amount of the silver nitrate aqueous solution is 1/10 or less of the amount of the reducing agent aqueous solution. Mixing the mixture, stirring the mixture for 10 to 300 minutes to prepare a dispersion made of metal colloid, and allowing the dispersion made of metal colloid to stand at room temperature to precipitate the precipitated metal nanoparticles. A step of separating the aggregate from the dispersion, a step of adding water to the separation to form a dispersion, and separating coarse particles obtained by desalting the dispersion by ultrafiltration Particle size 10-50 a step of obtaining a metal nanoparticle dispersion containing 70% or more of metal nanoparticles within the range of m in number average, and the metal nanoparticle dispersion of 1,2-propanediol, dimethyl sulfoxide or N-methylformamide. look including the step of obtaining an electrode-forming composition of the solar cell was replaced washed with either aqueous sodium the citrate are those obtained by dissolving sodium citrate in deionized water, the metal nano Particles are dispersed in a dispersion medium, silver nanoparticles having 75% by weight or more of metal nanoparticles, and Au, Pt, Pd, Ru, Ni, Cu, Sn, In, Zn having 0.02% by weight or more and less than 25% by weight. , Fe, Cr, or Mn nanoparticles, the metal nanoparticles are chemically modified with a protective agent of an organic molecular main chain having 1 to 3 carbon atoms in the carbon skeleton, and the metal nanoparticles have a primary particle size of 10 to 50 nm. The number of metal nanoparticles in the range is 70% or more on average, the dispersion medium is any of 1,2-propanediol, dimethyl sulfoxide, or N-methylformamide, and the metal content is 2.5 to 95 mass. % Of the composition for forming a solar cell electrode.

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％以上の銀ナノ粒子を含有し、炭素骨格が炭素数１〜３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１０〜５０ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上含有し、更に分散媒が１，２−プロパンジオール、ジメチルスルホキシド又はＮ−メチルホルムアミドのいずれかであるので、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、保護剤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太陽電池の電極を形成すると、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、実質的に有機物を含有しない銀を主成分とする電極が得られる。従って、上記電極の形成された太陽電池を長年使用しても、有機物が変質又は劣化するということがなく、導電率及び反射率が高い状態に維持されるので、経年安定性に優れた電極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 the protective agent for the organic molecular main chain having a carbon skeleton of 1 to 3 carbon atoms. in metal nanoparticles is chemically modified, contain further 70% or more by number average metal nanoparticles within the metal nanoparticle primary particle size 10 to 50 nm, further dispersion medium 1,2-propanediol, di-methyl Since it is either sulfoxide or N-methylformamide, the specific surface area of the metal nanoparticles in this composition is relatively reduced, and the proportion of the protective agent is reduced. As a result, when an electrode of a solar cell 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 separated and decomposed to substantially remove the organic matter. An electrode composed mainly of silver not containing is obtained. Therefore, even if the solar cell on which the electrode is formed is used for many years, the organic matter is not deteriorated or deteriorated, and the electrical conductivity and the reflectance are maintained in a high state. Can be obtained.

また上記電極形成用組成物を基材上に湿式塗工法で塗工して焼成後の厚さが０．１〜２．０μｍの範囲内となるように成膜し、この上面に成膜された基材を１３０〜４００℃で焼成すれば、金属ナノ粒子の表面を保護していた保護剤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、実質的に有機物を含有しない銀を主成分とする電極が得られる。この結果、上記と同様に、電極の形成された太陽電池を長年使用しても、導電率及び反射率が高い状態に維持されるので、経年安定性に優れた電極を得ることができる。 In addition, the electrode forming composition is applied onto a substrate by a wet coating method, and a film is formed so that the thickness after firing is within a range of 0.1 to 2.0 μm, and the film is formed on this upper surface. If the base material is baked at 130 to 400 ° C., the protective agent that protected the surface of the metal nanoparticles was detached or decomposed, or separated and decomposed, so that substantially no organic matter-containing silver was obtained. An electrode having the main component is obtained. As a result, similarly to the above, even if the solar cell on which the electrode is formed is used for many years, the conductivity and the reflectance are maintained at a high level, so that an electrode having excellent aging stability can be obtained.

次に本発明を実施するための形態を説明する。 Next, the form for implementing this invention is demonstrated.

本発明の組成物は、金属ナノ粒子が分散媒に分散した太陽電池の電極形成用組成物である。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１〜３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１０〜５０ｎｍ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太陽電池の電極の反射率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１〜３の範囲に限定したのは、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、上記電極内に有機残渣が多く残り、変質又は劣化して電極の導電性及び反射率が低下してしまうからである。また一次粒径１０〜５０ｎｍ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質量％未満では金属ナノ粒子の比表面積が増大して保護剤割合が大きくなり、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、電極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及び反射率が低下したり、或いは金属ナノ粒子の粒度分布が広くなり電極の密度が低下し易くなって、電極の導電性及び反射率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１０〜５０ｎｍの範囲内に限定したのは、統計的手法より一次粒径が１０〜５０ｎｍ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 a composition for forming an electrode of a solar cell 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 1 to 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 10 to 50 nm in terms of 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 less than 75% by mass of solar cells formed using this composition. This is because the reflectance of the electrode is lowered. Moreover, the carbon number of the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying the metal nanoparticles was limited to the range of 1 to 3 because the protective agent was removed by the heat during firing if the carbon number was 4 or more. This is because separation or decomposition (separation / combustion) is difficult, and a large amount of organic residue remains in the electrode, resulting in alteration or deterioration, resulting in a decrease in the conductivity and reflectance of the electrode. In addition, the content of the metal nanoparticles in the range of the primary particle size of 10 to 50 nm is limited to the range of 70% or more with respect to 100% of all the metal nanoparticles on the number average. Since the specific surface area of the particles increases and the proportion of the protective agent increases, even in the case of organic molecules that are easily desorbed or decomposed (separated / combusted) by the heat during firing, the organic molecules account for a large proportion. Many organic residues remain, and the residue is altered or deteriorated to reduce the conductivity and reflectivity of the electrode, or the particle size distribution of the metal nanoparticles becomes wide and the electrode density tends to decrease. This is because the properties and reflectivity are reduced. Furthermore, the primary particle size of the metal nanoparticles was limited to the range of 10 to 50 nm because the metal nanoparticles having a primary particle size within the range of 10 to 50 nm are 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、１，２−プロパンジオール、ジメチルスルホキシド又はＮ−メチルホルムアミドのいずれかである。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極の特性には影響はないけれども、必要な厚さの電極を得ることが難しく、９５．０質量％を越えると組成物の湿式塗工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。分散媒を１，２−プロパンジオール、ジメチルスルホキシド又はＮ−メチルホルムアミドのいずれかに限定したのは、これらの分散媒を使うと金属ナノ粒子が長期間凝集を起こさず安定であり、その結果湿式塗工法により塗工して得られた膜は低温で焼結でき、また焼成後の電極の導電性と反射率が良好であるからである。

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 is 1,2-propanediol is either di-methyl sulfoxide or N- methyl formamide. 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 it is less than 5% by mass, the properties of the electrode after firing are not particularly affected, but it is difficult to obtain an electrode having a required thickness. If it exceeds 95.0% by mass, it can be used as an ink or paste during wet coating of the composition. This is because the necessary liquidity is lost. The reason for limiting the dispersion medium to 1,2-propanediol , dimethyl sulfoxide or N-methylformamide is that when these dispersion media are used, the metal nanoparticles do not aggregate for a long period of time and are stable. This is because the film obtained by coating by the coating method can be sintered at a low temperature, and the conductivity and reflectance of the electrode after firing are good.

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、Ｃｒ、Ｆｅ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。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）後の電極の導電性及び反射率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極の導電性及び反射率が低下し、しかも耐候性試験後の電極が耐候性試験前の電極より導電性及び反射率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, Cr, Fe 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. 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. However, in the range of 0.02 to 25% by mass, the conductivity of the electrode 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). And 25% by mass or more, the conductivity and reflectance of the electrode immediately after firing are reduced, and the electrode after the weathering test is the electrode before the weathering test. This is because the conductivity and reflectance are further reduced.

このように構成された太陽電池の電極形成用組成物の製造方法を説明する。 The manufacturing method of the composition for electrode formation of the solar cell comprised in this way is demonstrated.

(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、金属塩水溶液中の金属イオンの総原子価数に対する、還元剤水溶液中のクエン酸イオンと第一鉄イオンのモル比がいずれも３倍モルとなるようにする。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、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１０〜５０ｎｍ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１０〜５０ｎｍ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１０〜５０ｎｍ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。更に引き続いて１，２−プロパンジオール、ジメチルスルホキシド又はＮ−メチルホルムアミドのいずれかで置換洗浄して、金属（銀）の含有量を２．５〜５０質量％にする。 (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 such that the molar ratio of the citrate ions and the ferrous ions in the reducing agent aqueous solution is 3 times the total valence of the metal ions in the metal salt aqueous solution. . 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. After that, the metal nanoparticles having a primary particle diameter of 10 to 50 nm are obtained by adjusting the centrifugal force of the centrifuge using a centrifuge and separating coarse particles. Prepare so as to contain 70% or more in number average, that is, adjust the proportion of metal nanoparticles in the range of primary particle size of 10 to 50 nm to 100% of all metal nanoparticles in number average to be 70% or more. To do. Although described as metal nanoparticles, in the case of (a), the proportion of silver nanoparticles in the range of the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles is 70% or more. It is adjusted so that Subsequent to substitution washing with either 1,2-propanediol , dimethyl sulfoxide or N-methylformamide, the metal (silver) content is adjusted to 2.5 to 50% by mass.

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１０〜５０ｎｍ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 10 to 50 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（太陽電池の電極形成用組成物）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％とするとともに、溶媒は１，２−プロパンジオール、ジメチルスルホキシド又はＮ−メチルホルムアミドのいずれかを使用する。 As a result, a dispersion (a composition for forming an electrode of a solar cell) in which the carbon skeleton of the carbon skeleton of the organic molecular main chain of the protective agent that chemically modifies 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, and the solvent is any of 1,2-propanediol , dimethyl sulfoxide, or N-methylformamide. Use.

(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（太陽電池の電極形成用組成物）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 set to 2 except that sodium citrate used when preparing the reducing agent aqueous solution is replaced with sodium malate A dispersion is prepared in the same manner as (a) above. As a result, a dispersion (a composition for forming an electrode for a solar cell) in which the carbon skeleton of the organic molecular main chain that chemically modifies the silver nanoparticles is 2 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（太陽電池の電極形成用組成物）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, a dispersion (composition for forming an electrode of a solar cell) in which the carbon skeleton of the organic molecular main chain that chemically modifies the silver nanoparticles has 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（太陽電池の電極形成用組成物）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. As a result, a dispersion (a composition for forming an electrode for a solar cell) in which the carbon skeleton of the organic molecular main chain of the protective agent for chemically modifying metal nanoparticles other than 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（太陽電池の電極形成用組成物）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 electrode formation of a solar cell) whose carbon number of the carbon skeleton of the organic molecular principal chain of the protective agent which chemically modifies metal nanoparticles other than silver nanoparticles is 1 or 2 is obtained.

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（太陽電池の電極形成用組成物）を用いて電極を形成する方法を説明する。 A method for forming an electrode using the dispersion (a composition for forming an electrode of a solar cell) thus manufactured will be described.

先ず上記分散体（太陽電池の電極形成用組成物）を基材上に湿式塗工法で塗工する。この湿式塗工法での塗工は、焼成後の厚さが０．１〜２．０μｍ、好ましくは０．３〜１．５μｍの範囲内となるように成膜する。上記基材は、シリコン、ガラス、透明導電材料を含むセラミックス、高分子材料又は金属からなる基板のいずれか、或いはシリコン、ガラス、透明導電材料を含むセラミックス、高分子材料及び金属からなる群より選ばれた２種以上の積層体であることができる。また基材は太陽電池素子又は透明電極付き太陽電池素子のいずれかであることが好ましい。透明電極としては、インジウム錫酸化物（Indium Tin Oxide：ＩＴＯ）、アンチモンドープ酸化錫（Antimony Tin Oxide：ＡＴＯ）、ネサ（酸化錫ＳｎＯ₂）、ＩＺＯ（Indium Zic Oxide）、ＡＺＯ（アルミドープＺｎＯ）等などが挙げられる。上記分散体は太陽電池素子の光電変換半導体層の表面や、透明電極付き太陽電池素子の透明電極の表面に塗布される。更に上記湿式塗工法は、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 (a composition for forming an electrode of a solar cell) is coated on a substrate by a wet coating method. Coating by this wet coating method is performed so that the thickness after firing is in the range of 0.1 to 2.0 μm, preferably 0.3 to 1.5 μm. The substrate is selected from the group consisting of silicon, glass, ceramics containing a transparent conductive material, a polymer material or a metal substrate, or silicon, glass, ceramics containing a transparent conductive material, a polymer material and a metal. It can be a laminate of two or more types. Moreover, it is preferable that a base material is either a solar cell element or a solar cell element with a transparent electrode. Transparent electrodes include indium tin oxide (ITO), antimony-doped tin oxide (ATO), nesa (tin oxide SnO ₂ ), IZO (Indium Zic Oxide), and AZO (aluminum-doped ZnO). Etc. The said dispersion is apply | coated to the surface of the photoelectric conversion semiconductor layer of a solar cell element, or the surface of the transparent electrode of a solar cell element with a transparent electrode. Further, the wet coating method is particularly 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. Although it is preferable, 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.

次に上面に成膜された基材を大気中で１３０〜４００℃、好ましくは１４０〜２００℃の温度に、１０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、基材上に形成された分散体の膜厚を、焼成後の厚さが０．１〜２．０μｍの範囲内となるように限定したのは、０．１μｍ未満では太陽電池に必要な電極の表面抵抗値が不十分となり、２．０μｍを越えると特性上の不具合はないけれども、材料の使用量が必要以上に多くなって材料が無駄になるからである。また基材上に形成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、焼成後の電極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及び反射率が低下してしまい、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。更に基材上に形成された分散体の膜の焼成時間を１０分間〜１時間の範囲に限定したのは、１０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、焼成後の電極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及び反射率が低下してしまい、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 base material formed on the upper surface is fired in the air at a temperature of 130 to 400 ° C., preferably 140 to 200 ° C., for 10 minutes to 1 hour, preferably 15 to 40 minutes. Here, the film thickness of the dispersion formed on the substrate was limited so that the thickness after firing was in the range of 0.1 to 2.0 μm. This is because the necessary surface resistance value of the electrode becomes insufficient, and if it exceeds 2.0 μm, there is no problem in characteristics, but the amount of material used is increased more than necessary and the material is wasted. In addition, the firing temperature of the dispersion film formed on the base material was limited to the range of 130 to 400 ° C. When the temperature was lower than 130 ° C., the sintering between the metal nanoparticles became insufficient and the protective agent was fired. It is difficult to desorb or decompose (separate / combust) due to the heat of heat, so that a lot of organic residue remains in the electrode after firing, and this residue is altered or deteriorated, resulting in a decrease in conductivity and reflectance. This is because the production advantage of the low-temperature process cannot be utilized, that is, the manufacturing cost increases and the productivity decreases. Furthermore, the firing time of the dispersion film formed on the base material was limited to the range of 10 minutes to 1 hour because the sintering of the metal nanoparticles became insufficient and the firing of the protective agent in less than 10 minutes. Due to the difficulty of desorption or decomposition (separation / combustion) due to the heat of the time, a lot of organic residue remains in the electrode after firing, the residue is altered or deteriorated, and the conductivity and reflectivity of the electrode decrease, This is because, if the time exceeds 1 hour, the characteristics are not affected, but the manufacturing cost is increased more than necessary and the productivity is lowered.

上記太陽電池の電極形成用組成物では、一次粒径１０〜５０ｎｍ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太陽電池の電極を形成すると、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電極が得られる。従って、上記電極の形成された太陽電池を長年使用しても、有機物が変質又は劣化するということがなく、電極の導電率及び反射率が高い状態に維持されるので、経年安定性に優れた電極を得ることができる。具体的には、上記電極を、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、波長７５０〜１５００ｎｍの電磁波、即ち可視光領域から赤外線領域までの電磁波を８０％以上電極により反射できるとともに、電極の導電性、即ち電極の体積抵抗率を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電極を用いた太陽電池は、長年使用しても高導電率及び高反射率を維持することができ、経年安定性に優れる。 Since the composition for forming an electrode of the solar cell contains a large amount of metal nanoparticles having a primary particle size of 10 to 50 nm and a relatively large size, the specific surface area of the metal nanoparticles is reduced and the proportion of the protective agent is reduced. As a result, when an electrode of a solar cell is formed using the composition, the organic molecules in the protective agent are desorbed or decomposed by the heat at the time of firing, or desorbed and decomposed, thereby substantially reducing the organic matter. An electrode composed mainly of silver not containing is obtained. Therefore, even if the solar cell on which the electrode is formed is used for many years, the organic matter is not deteriorated or deteriorated, and the conductivity and reflectivity of the electrode are maintained in a high state, so that the aging stability is excellent. An electrode can be obtained. Specifically, even after the electrode is accommodated for 1000 hours in a constant temperature and humidity chamber maintained at a temperature of 100 ° C. and a humidity of 50%, the electromagnetic wave having a wavelength of 750 to 1500 nm, that is, from the visible light region. Electromagnetic waves up to the infrared region can be reflected by 80% or more by the electrode, and the conductivity of the electrode, that is, the volume resistivity of the electrode is extremely low, less than 2 × 10 ⁻⁵ Ω · cm (20 × 10 ⁻⁶ Ω · cm). Can be maintained. The solar cell using the electrode formed in this way can maintain high conductivity and high reflectance even when used for many years, and is excellent in aging stability.

＜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。また上記両水溶液の混合比は、金属塩水溶液中の金属イオンの総原子価数に対する、還元剤水溶液中のクエン酸イオンと第一鉄イオンのモル比がいずれも３倍モルとなるようにした。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、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１０〜５０ｎｍ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１０〜５０ｎｍの範囲内の銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いて１，２−プロパンジオールで置換洗浄して、金属（銀）の含有量を７０質量％にした。この分散体を実施例１とした。 <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 two aqueous solutions was such that the molar ratio of the citrate ion and ferrous ion in the reducing agent aqueous solution to the total valence of the metal ions in the metal salt aqueous solution was 3 times as much as each other. . 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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, silver nanoparticles in the range of primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average It adjusted so that the ratio which occupies might be 75%. Further, it was then substituted and washed with 1,2-propanediol to make the metal (silver) content 70% by mass. This dispersion was designated as Example 1.

＜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、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１０〜５０ｎｍの銀ナノ粒子を数平均で９０％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１０〜５０ｎｍの銀ナノ粒子の占める割合が９０％になるように調整した。更に引き続いて１，２−プロパンジオールで置換洗浄して、金属の含有量を７０質量％にした。この分散体を実施例２とした。 <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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 90% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the ratio of silver nanoparticles having a primary particle size of 10 to 50 nm to 100% of all silver nanoparticles in number average Was adjusted to 90%. Further, it was then substituted and washed with 1,2-propanediol to make the metal content 70% by mass. This dispersion was designated as Example 2.

＜実施例３＞
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、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１０〜５０ｎｍの銀ナノ粒子を数平均で１００％含有するように調製した。更に引き続いて１，２−プロパンジオールで置換洗浄して、金属の含有量を７０質量％にした。この分散体を実施例３とした。 <Example 3>
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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 100% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average. Further, it was then substituted and washed with 1,2-propanediol to make the metal content 70% by mass. This dispersion was designated as Example 3.

＜実施例４＞
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、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１０〜５０ｎｍ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１０〜５０ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いて１，２−プロパンジオールで置換洗浄して、金属の含有量を７０質量％にした。この分散体を実施例４とした。 <Example 4>
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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the ratio of silver nanoparticles having a primary particle size of 10 to 50 nm to 100% of all silver nanoparticles in number average Was adjusted to 75%. Further, it was then substituted and washed with 1,2-propanediol to make the metal content 70% by mass. This dispersion was designated as Example 4.

＜実施例５＞
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、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１０〜５０ｎｍ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１０〜５０ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いて１，２−プロパンジオールで置換洗浄して、金属の含有量を７０質量％にした。この分散体を実施例５とした。 <Example 5>
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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the ratio of silver nanoparticles having a primary particle size of 10 to 50 nm to 100% of all silver nanoparticles in number average Was adjusted to 75%. Further, it was then substituted and washed with 1,2-propanediol to make the metal content 70% by mass. This dispersion was designated as Example 5.

＜実施例６＞
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、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１０〜５０ｎｍ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質量％に対する一次粒径１０〜５０ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いてジメチルスルホキシドで置換洗浄して、金属の含有量を７０質量％にした。この分散体を実施例６とした。 <Example 6 >
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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain silver nanoparticles having a primary particle size of 10 to 50 nm in a number average of 75%. That is, silver nanoparticles having a primary particle size of 10 to 50 nm accounted for 100% by mass of all silver nanoparticles in the number average. The ratio was adjusted to 75%. Further, it was subsequently substituted and washed with dimethyl sulfoxide to make the metal content 70% by mass. This dispersion was designated as Example 6 .

＜実施例７＞
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、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１０〜５０ｎｍ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質量％に対する一次粒径１０〜５０ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いてＮ−メチルホルムアミドで置換洗浄して、金属の含有量を７０質量％にした。この分散体を実施例７とした。 <Example 7 >
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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain silver nanoparticles having a primary particle size of 10 to 50 nm in a number average of 75%. That is, silver nanoparticles having a primary particle size of 10 to 50 nm accounted for 100% by mass of all silver nanoparticles in the number average. The ratio was adjusted to 75%. Further, N-methylformamide was subsequently substituted and washed to make the metal content 70% by mass. This dispersion was designated as Example 7 .

＜実施例８＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を塩化金酸に替え、実施例１と同様にして金ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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。この分散体を実施例８とした。 <Example 8 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with chloroauric acid, and the gold nanoparticles contained 75% of the average number of gold nanoparticles having a primary particle size of 10 to 50 nm as in Example 1, that is, the number average. It adjusted with the centrifuge so that the ratio for which the gold nanoparticle with a primary particle diameter of 10-50 nm with respect to 100% of all the gold nanoparticles might be 75%. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. 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. This dispersion was designated as Example 8 .

＜実施例９＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を塩化白金酸に替え、実施例１と同様にして白金ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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。この分散体を実施例９とした。 <Example 9 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate in Example 1 was replaced with chloroplatinic acid, and the platinum nanoparticles contained 75% of the number average platinum nanoparticles having a primary particle size of 10 to 50 nm as in Example 1, that is, the number average. It adjusted with the centrifuge so that the ratio for which the platinum particle of primary particle size 10-50nm might occupy 75% with respect to 100% of all the platinum nanoparticles. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. 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. This dispersion was designated as Example 9 .

＜実施例１０＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を硝酸パラジウムに替え、実施例１と同様にしてパラジウムナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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。この分散体を実施例１０とした。 <Example 10 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with palladium nitrate, and in the same manner as in Example 1, the palladium nanoparticles contained 75% of the average number of palladium nanoparticles having a primary particle size of 10 to 50 nm. It adjusted with the centrifuge so that the ratio for which the palladium nanoparticle with a primary particle diameter of 10-50 nm might occupy 75% with respect to 100% of palladium nanoparticles. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. 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. This dispersion was designated as Example 10 .

＜実施例１１＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を三塩化ルテニウムに替え、実施例１と同様にしてルテニウムナノ粒子が一次粒径１０〜５０ｎｍ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粒子１００％に対する一次粒径１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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％、ルテニウムナノ粒子が２０質量％となるように混合した。この分散体を実施例１１とした。 <Example 11 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with ruthenium trichloride, and the ruthenium nanoparticles contained ruthenium nanoparticles having a primary particle diameter of 10 to 50 nm in a number average of 75% in the same manner as in Example 1, that is, the number average. The ratio of ruthenium nanoparticles having a primary particle size of 10 to 50 nm to 100% of all ruthenium particles was adjusted by a centrifuge so that the ratio was 75%. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 80% by mass and the ruthenium nanoparticles were 20% by mass. This dispersion was designated as Example 11 .

＜実施例１２＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を塩化ニッケルに替え、実施例１と同様にしてニッケルナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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９９．５質量％、ニッケルナノ粒子が０．５質量％となるように混合した。この分散体を実施例１２とした。 <Example 12 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with nickel chloride, and the nickel nanoparticles contained 75% of the average number of nickel nanoparticles having a primary particle diameter of 10 to 50 nm in the same manner as in Example 1, that is, all of the number averages. The ratio of nickel nanoparticles having a primary particle size of 10 to 50 nm to 100% of nickel nanoparticles was adjusted to 75% by a centrifuge. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 99.5% by mass and the nickel nanoparticles were 0.5% by mass. This dispersion was designated as Example 12 .

＜実施例１３＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を硝酸第一銅に替え、実施例１と同様にして銅ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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９０質量％、銅ナノ粒子が１０質量％となるように混合した。この分散体を実施例１３とした。 <Example 13 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 is replaced with cuprous nitrate, and the copper nanoparticles contain 75% of the average number of copper nanoparticles having a primary particle size of 10 to 50 nm as in Example 1, that is, the number average. Thus, the ratio of the copper nanoparticles having a primary particle size of 10 to 50 nm to 100% of all the copper nanoparticles was adjusted to 75% by a centrifuge. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 90% by mass and the copper nanoparticles were 10% by mass. This dispersion was designated as Example 13 .

＜実施例１４＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を二塩化錫に替え、実施例１と同様にして錫ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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％、錫ナノ粒子が５質量％となるように混合した。この分散体を実施例１４とした。 <Example 14 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with tin dichloride, and the same manner as in Example 1, so that the tin nanoparticles contained 75% of the average number of tin nanoparticles having a primary particle size of 10 to 50 nm, that is, the number average. It adjusted with the centrifuge so that the ratio for which the tin particle of primary particle size 10-50nm might occupy 75% with respect to 100% of all the tin nanoparticles. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 95% by mass and the tin nanoparticles were 5% by mass. This dispersion was designated as Example 14 .

＜実施例１５＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を硝酸インジウムに替え、実施例１と同様にしてインジウムナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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。この分散体を実施例１５とした。 <Example 15 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate in Example 1 was replaced with indium nitrate, and in the same manner as in Example 1, the indium nanoparticles contained 75% indium nanoparticles with a primary particle size of 10 to 50 nm in number average, that is, all in number average. The amount of tin nanoparticles having a primary particle size of 10 to 50 nm with respect to 100% of the indium nanoparticles was adjusted to 75% by a centrifuge. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. 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. This dispersion was designated as Example 15 .

＜実施例１６＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を塩化亜鉛に替え、実施例１と同様にして亜鉛ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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９８質量％、亜鉛ナノ粒子が２質量％となるように混合した。この分散体を実施例１６とした。 <Example 16 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with zinc chloride, and in the same manner as in Example 1, the zinc nanoparticles contained 75% of zinc nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, all in number average. The ratio of zinc nanoparticles having a primary particle size of 10 to 50 nm to 100% of zinc nanoparticles was adjusted to 75% by a centrifuge. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 98% by mass and the zinc nanoparticles were 2% by mass. This dispersion was designated as Example 16 .

＜実施例１７＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を硫酸鉄に替え、実施例１と同様にして鉄ナノ粒子が一次粒径１０〜５０ｎｍ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鉄ナノ粒子１００％に対する一次粒径１０〜５０ｎｍの鉄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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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％、鉄ナノ粒子が５質量％となるように混合した。この分散体を実施例１７とした。 <Example 17 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with iron sulfate, and in the same manner as in Example 1, the iron nanoparticles contained zinc nanoparticles having a primary particle size of 10 to 50 nm in a number average of 75%, that is, all in number average. The ratio of iron nanoparticles having a primary particle diameter of 10 to 50 nm to 100% of iron nanoparticles was adjusted to 75% by a centrifuge. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. Next, the first dispersion and the second dispersion were mixed so that the silver nanoparticles were 95% by mass and the iron nanoparticles were 5% by mass. This dispersion was designated as Example 17 .

＜実施例１８＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を硫酸クロムに替え、実施例１と同様にしてクロムナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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。この分散体を実施例１８とした。 <Example 18 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with chromium sulfate, and the chromium nanoparticles contained 75% of the average number of chromium nanoparticles having a primary particle size of 10 to 50 nm in the same manner as in Example 1, that is, all the chromium nanoparticles were averaged. It adjusted with the centrifuge so that the ratio for which the primary particle diameter of 10-50 nm of chromium nanoparticles with respect to 100% of particles might be 75%. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. 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. This dispersion was designated as Example 18 .

＜実施例１９＞
実施例１と同様にして銀ナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第１分散体を得た。一方、実施例１の硝酸銀を硫酸マンガンに替え、実施例１と同様にしてマンガンナノ粒子が一次粒径１０〜５０ｎｍ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１０〜５０ｎｍ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た。更に引続いて１，２−プロパンジオールで置換洗浄して第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。この分散体を実施例１９とした。 <Example 19 >
In the same manner as in Example 1, the silver nanoparticles contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the primary particle size of 10 to 50 nm with respect to 100% of all silver nanoparticles in number average. It adjusted with the centrifuge so that the ratio for which the silver nanoparticle occupied might be 75%. Further, the first dispersion was obtained by subsequent substitution washing with 1,2-propanediol. On the other hand, the silver nitrate of Example 1 was replaced with manganese sulfate, and in the same manner as in Example 1, the manganese nanoparticles contained 75% of the average number of manganese nanoparticles having a primary particle size of 10 to 50 nm. It adjusted with the centrifuge so that the ratio for which the manganese nanoparticle with a primary particle diameter of 10-50 nm might occupy 75% with respect to 100% of manganese nanoparticles. Further, the second dispersion was obtained by subsequent substitution washing with 1,2-propanediol. 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. This dispersion was designated as Example 19 .

＜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、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１０〜５０ｎｍ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１０〜５０ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いて、金属の含有量が７０％になるように脱イオン水の量を調整した。この分散体を比較例１とした。 <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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 75% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the ratio of silver nanoparticles having a primary particle size of 10 to 50 nm to 100% of all silver nanoparticles in number average Was adjusted to 75%. Subsequently, the amount of deionized water was adjusted so that the metal content was 70%. This dispersion was designated as Comparative Example 1.

＜比較例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、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１０〜５０ｎｍの銀ナノ粒子を数平均で９０％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１０〜５０ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いて１−メトキシ−２−プロパノールで置換洗浄して、金属の含有量を７０質量％にした。この分散体を比較例２とした。 <Comparative 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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 90% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the ratio of silver nanoparticles having a primary particle size of 10 to 50 nm to 100% of all silver nanoparticles in number average Was adjusted to 75%. Further, it was subsequently substituted and washed with 1-methoxy-2-propanol to make the metal content 70% by mass. This dispersion was designated as Comparative Example 2.

＜比較例３＞
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、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１０〜５０ｎｍの銀ナノ粒子を数平均で９０％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１０〜５０ｎｍの銀ナノ粒子の占める割合が７５％になるように調整した。更に引き続いてトルエンで置換洗浄して、金属の含有量を７０質量％にした。この分散体を比較例３とした。 <Comparative Example 3>
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. After adding deionized water to this separated product to form a dispersion and desalting by ultrafiltration, the centrifugal force of this centrifuge is adjusted using a centrifuge to separate coarse particles, thereby obtaining silver nanoparticles. The particles were prepared so as to contain 90% of silver nanoparticles having a primary particle size of 10 to 50 nm in number average, that is, the ratio of silver nanoparticles having a primary particle size of 10 to 50 nm to 100% of all silver nanoparticles in number average Was adjusted to 75%. Further, it was subsequently substituted and washed with toluene to make the metal content 70% by mass. This dispersion was designated as Comparative Example 3.

＜比較試験１及び評価＞
実施例１〜１９及び比較例１〜３の分散体を次の表３及び表４に示される基材上に、焼成後の膜厚が１μｍとなるように次の表３及び表４に示される塗工法により塗布した。基材としては、ＩＴＯ又はＰＥＴを用いた。塗工法としては、ナイフコーティング又はスピンコーティングを用いた。ここで分散体を基材上に塗布した塗膜について、その塗工性を目視により確認した。続いて、実施例１〜１９の塗膜を、次の表３に示される温度で焼成することにより、基材上に電極を形成した。これらの電極を形成した基材について、耐候性試験を行う前に、各基材に形成された電極の反射率及び導電性を測定するとともに、耐候性試験を行った後に、各基材に形成された電極の反射率及び導電性を測定した。その結果を、表３に示す。また、比較例１〜３についての塗膜の状態を観察した。その結果を、表４に示す。 <Comparative test 1 and evaluation>
The dispersions of Examples 1 to 19 and Comparative Examples 1 to 3 are shown in the following Tables 3 and 4 so that the film thickness after firing is 1 μm on the substrates shown in the following Tables 3 and 4. The coating method was applied. ITO or PET was used as the substrate. As the coating method, knife coating or spin coating was used. Here, about the coating film which apply | coated the dispersion material on the base material, the coating property was confirmed visually. Subsequently, the coating films of Examples 1 to 19 were baked at the temperatures shown in the following Table 3 to form electrodes on the substrate. Before performing the weather resistance test on the base material on which these electrodes are formed, the reflectance and conductivity of the electrode formed on each base material are measured, and after the weather resistance test is performed, each electrode is formed on each base material. The reflectivity and conductivity of the prepared electrodes were measured. The results are shown in Table 3. Moreover, the state of the coating film about Comparative Examples 1-3 was observed. The results are shown in Table 4.

なお、耐候性試験は、電極の形成された基材を、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 substrate on which the electrode was formed in a constant temperature and humidity chamber having a temperature of 100 ° C. and a humidity of 50% for 1000 hours.

また、反射率は、波長７５０〜１５００ｎｍの電磁波（赤外線及び可視光線）を電極に照射し、反射した電磁波を紫外可視分光光度計（Ｖ−５７０：日本分光社製）を用いて測定し、全照射量に対する反射量の割合（％）を算出して求めた。 The reflectance was measured by irradiating an electrode with electromagnetic waves (infrared rays and visible rays) having a wavelength of 750 to 1500 nm, and measuring the reflected electromagnetic waves using an ultraviolet-visible spectrophotometer (V-570: manufactured by JASCO Corporation). The ratio (%) of the reflection amount with respect to the irradiation amount was calculated and obtained.

また、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１０〜５０ｎｍ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。 The primary particle size of the metal nanoparticles is measured using FE-TEM (field emission transmission electron microscope: manufactured by JEOL Ltd.), and the proportion of silver nanoparticles having a primary particle size of 10 to 50 nm is determined by the above FE. -From the photograph of the primary particle diameter of the metal nanoparticles photographed using TEM, the number of particle diameters was measured and evaluated.

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、電極の体積抵抗率は、先ず焼成後の電極の厚さをＳＥＭ（電子顕微鏡Ｓ８００：日立製作所社製）を用いて電極断面から電極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電極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 electrode is determined by first measuring the thickness of the electrode after firing directly from the electrode cross section using an SEM (Electron Microscope S800: manufactured by Hitachi, Ltd.), Using a specific resistance measuring instrument (Loresta: manufactured by Mitsubishi Chemical Corporation) by the terminal method, the measured thickness of the electrode was input to this measuring instrument.

一方、表１及び表２に、実施例１〜１９及び比較例１〜３の分散体における一次粒径１０〜５０ｎｍ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、分散体（組成物）の種類及び混合割合と、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）とを示した。また表３及び表４には、反射率、導電性（体積抵抗率）及び耐候性とともに、基材の種類、塗工性及び焼成温度を示した。表３及び表４の塗工性の欄において、『良好』とは、基材上に一様に塗工できた場合を示し、『不良』とは基材が塗液となる分散体を弾いたりして基材上に一様に塗工できなかった場合を示す。更に表３の耐候性の欄において、『良好』とは、反射率が８０％以上でありかつ体積抵抗率が２０×１０^-6Ω・ｃｍ未満であった場合を示し、『不良』とは反射率が８０％未満でありかつ体積抵抗率が２０×１０^-6Ω・ｃｍ未満であるか、又は反射率が８０％以上でありかつ体積抵抗率が２０×１０^-6Ω・ｃｍを越えるか、或いは反射率が８０％未満でありかつ体積抵抗率が２０×１０^-6Ω・ｃｍを越えた場合を示す。 On the other hand, in Tables 1 and 2, the proportion of metal nanoparticles having a primary particle size of 10 to 50 nm in the dispersions of Examples 1 to 19 and Comparative Examples 1 to 3, carbon number of organic molecular main chain, and dispersion Shows the type and mixing ratio of (composition) and the type and content of dissimilar metals (metals other than silver) (content of dissimilar metals when the total of metals other than silver and silver is 100% by mass). It was. Tables 3 and 4 show the type of substrate, coating properties, and firing temperature, as well as reflectance, conductivity (volume resistivity), and weather resistance. In the column of coating property in Table 3 and Table 4, “good” indicates a case where the coating was uniformly applied on the base material, and “bad” indicates that the base material repels the dispersion that becomes the coating liquid. The case where it was not able to apply uniformly on a base material is shown. Furthermore, in the weather resistance column of Table 3, “good” indicates a case where the reflectance is 80% or more and the volume resistivity is less than 20 × 10 ⁻⁶ Ω · cm. The reflectance is less than 80% and the volume resistivity is less than 20 × 10 ⁻⁶ Ω · cm, or the reflectance is 80% or more and the volume resistivity exceeds 20 × 10 ⁻⁶ Ω · cm. Or the reflectance is less than 80% and the volume resistivity exceeds 20 × 10 ⁻⁶ Ω · cm.

表３及び表４から明らかなように、比較例１〜３では、塗工性が悪く、塗膜の状態が、斑になったり、膜に多くの穴が形成されたりと、太陽電池の電極を形成するための組成物として使用するのには不適であることが確認された。これらに対し、実施例１〜１９では、基材への塗膜性はいずれも良好であり、耐候性試験前及び耐候性試験後のいずれであっても、電極の反射率が８０％以上でありかつ体積抵抗率が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 clear from Tables 3 and 4, in Comparative Examples 1 to 3, the coatability is poor, the state of the coating film becomes uneven, and many holes are formed in the film. It was confirmed that it was unsuitable for use as a composition for forming the. For these, in Examples 1 19 are both coating properties to the substrate was good, be any of before and after weather resistance test and weathering resistance test, in the reflectivity of the electrode is 80% or more In addition, the volume resistivity was less than 20 × 10 ⁻⁶ Ω · cm, and the initial characteristics before the weather resistance test and the weather resistance were sufficiently satisfied.

Claims

濃度１０〜４０％のクエン酸ナトリウム水溶液に不活性ガスの気流中で粒状又は粉状の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、
不活性ガスの気流中に前記還元剤水溶液を撹拌しながら硝酸銀水溶液を前記還元剤水溶液に、前記硝酸銀水溶液の添加量は前記還元剤水溶液の量の１／１０以下になるように滴下して混合する工程と、
前記混合液を１０〜３００分間撹拌して金属コロイドからなる分散液を調製する工程と、
前記金属コロイドからなる分散液を室温で放置して沈降した金属ナノ粒子の凝集体を前記分散液から分離する工程と、
前記分離物に水を加えて分散体とする工程と、
前記分散体を限外ろ過により脱塩処理して得られた粗粒子を分離することにより一次粒径１０〜５０ｎｍの範囲内の金属ナノ粒子を数平均で７０％以上含有する金属ナノ粒子分散液を得る工程と、
前記金属ナノ粒子分散液を１，２−プロパンジオール、ジメチルスホキシド又はＮ−メチルホルムアミドのいずれかで置換洗浄して太陽電池の電極形成用組成物を得る工程とを含み、
前記クエン酸ナトリウム水溶液は、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ものであり、金属ナノ粒子が分散媒に分散され、金属ナノ粒子が７５質量％以上の銀ナノ粒子と０．０２質量％以上かつ２５質量％未満のＡｕ、Ｐｔ、Ｐｄ、Ｒｕ、Ｎｉ、Ｃｕ、Ｓｎ、Ｉｎ、Ｚｎ、Ｆｅ、Ｃｒ又はＭｎのナノ粒子を含有し、前記金属ナノ粒子は炭素骨格が炭素数１〜３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１０〜５０ｎｍ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１，２−プロパンジオール、ジメチルスルホキシド又はＮ−メチルホルムアミドのいずれかであり、金属含有量が２．５〜９５質量％の範囲にあることを特徴とする太陽電池の電極形成用組成物の製造方法。 Preparing a reducing agent aqueous solution by dissolving by adding concentration 10-40% of granular or powdery ferrous sulfate aqueous sodium citrate solution in a stream of inert gas,
While stirring the reducing agent aqueous solution in an inert gas stream , the silver nitrate aqueous solution is added dropwise to the reducing agent aqueous solution, and the addition amount of the silver nitrate aqueous solution is dropped and mixed so that it is 1/10 or less of the amount of the reducing agent aqueous solution. And a process of
A step of stirring the mixture for 10 to 300 minutes to prepare a dispersion composed of metal colloid;
Separating the dispersion of the metal colloid from the dispersion by allowing the dispersion of metal nanoparticles to stand at room temperature and sedimenting the aggregated metal nanoparticles;
Adding water to the separated product to form a dispersion;
Dispersion of coarse particles obtained by desalting the dispersion by ultrafiltration to separate a metal nanoparticle dispersion containing 70% or more of metal nanoparticles having a primary particle size in the range of 10 to 50 nm. Obtaining
Look including a step of obtaining the metal nanoparticle dispersion of 1,2-propanediol, dimethyl sulfoxide or N- either the electrode-forming composition of the solar cell was replaced washed methyl formamide,
The sodium citrate aqueous solution is obtained by dissolving sodium citrate in deionized water. The metal nanoparticles are dispersed in a dispersion medium, the metal nanoparticles are 75% by mass or more of silver nanoparticles, and 0.0. It contains Au, Pt, Pd, Ru, Ni, Cu, Sn, In, Zn, Fe, Cr, or Mn nanoparticles in an amount of 02% by mass or more and less than 25% by mass. Are chemically modified with a protective agent for the organic molecular main chain of 1 to 3, and the metal nanoparticles contain 70% or more of metal nanoparticles having a primary particle size in the range of 10 to 50 nm in terms of number average; A method for producing a composition for forming an electrode of a solar cell, wherein the composition is any one of 2-propanediol, dimethyl sulfoxide, and N-methylformamide, and the metal content is in the range of 2.5 to 95% by mass .