WO2013136615A1 - Silver powder - Google Patents
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- WO2013136615A1 WO2013136615A1 PCT/JP2012/082330 JP2012082330W WO2013136615A1 WO 2013136615 A1 WO2013136615 A1 WO 2013136615A1 JP 2012082330 W JP2012082330 W JP 2012082330W WO 2013136615 A1 WO2013136615 A1 WO 2013136615A1
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- Prior art keywords
- silver
- sem
- silver powder
- powder
- aqueous solution
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
- B22F1/052—Metallic powder characterised by the size or surface area of the particles characterised by a mixture of particles of different sizes or by the particle size distribution
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
Definitions
- the present invention relates to a silver powder that can be suitably used for a sintered conductive paste.
- the conductive paste is a fluid composition in which a conductive filler is dispersed in a vehicle composed of a resin binder and a solvent, and is widely used for forming an electric circuit, an external electrode of a ceramic capacitor, and the like.
- This type of conductive paste includes a resin-curing type in which conductive fillers are pressure-bonded by hardening of the resin to ensure conduction, and a sintered type in which organic components are volatilized by high-temperature sintering and the conductive filler is sintered to ensure conduction. There is a type.
- the sintered conductive paste is generally a paste-like composition in which a conductive filler (metal powder) and glass frit are dispersed in an organic vehicle.
- a conductive filler metal powder
- glass frit By sintering at 400 to 800 ° C., The organic vehicle volatilizes and the conductive filler is sintered to ensure conductivity.
- the glass frit has a function of adhering the conductive film to the substrate, and the organic vehicle functions as an organic liquid medium for enabling printing of the metal powder and the glass frit.
- silver powder used in such a sintered conductive paste conventionally, silver powder having a fine particle size and sharp particle size distribution is generally required in order to cope with fine lines of electrodes and circuits.
- New technologies have been proposed.
- this type of silver powder includes a dry silver powder produced by a dry method and a wet silver powder produced by a wet method, but the wet silver powder is a dry silver powder because small crystals gather to form one particle. Compared to the above, the firing temperature is low.
- wet silver powder conventionally, for example, in Patent Document 1, it is obtained by image analysis of a scanning electron microscopic image as fine silver powder, which is fine silver powder having dispersibility close to monodispersion with little aggregation of powder particles.
- the average particle diameter D IA of the primary particles is 0.6 ⁇ m or less, and the average particle diameter D IA of the primary particles and the average particle diameter D 50 by the laser diffraction scattering type particle size distribution measurement method are used to obtain D 50 / D IA
- a fine silver powder having a cohesion degree of 1.5 or less, a crystallite diameter of 10 nm or less, and an organic impurity content of 0.25 wt% or less in terms of carbon amount has been proposed.
- Patent Document 2 discloses a cumulative 10% by mass particle size measured by laser diffraction method as a spherical silver powder having an average particle size of 0.1 ⁇ m or more and less than 1 ⁇ m, sharp particle size distribution and high dispersibility.
- the cumulative 50 mass% particle diameter is expressed as D50
- the cumulative 90 mass% particle diameter is expressed as D90
- the average particle diameter of the primary particles obtained from the image analysis of the scanning electron microscope image is expressed as DSEM
- D50 is 0.00.
- a spherical silver powder characterized by having a value of 1 ⁇ m or more and less than 1 ⁇ m, a D50 / DSEM value of 1.3 or less, and a (D90-D10) / D50 value of 0.8 or less.
- the present invention is to provide a new silver powder that can increase the silver concentration in the silver paste, can form a sintered conductor that is homogeneous and has a lower electrical resistance.
- D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope image (SEM) is 2.50 ⁇ m to 7.50 ⁇ m, and image analysis of a scanning electron microscope image (SEM)
- SEM D10 The relationship between the obtained D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”) and D90 (referred to as “ SEM D90”) is the relational expression: ( SEM D90- SEM D10) / SEM D50 ⁇ 0 A silver powder characterized by .50 is proposed.
- the silver powder proposed by the present invention can increase the silver concentration in the silver paste, and can form a sintered conductor that is homogeneous and has an even lower electrical resistance. Since conventional silver powder particles contain a large amount of fine particles, the specific surface area is generally large, and a large amount of resin is required when preparing a silver paste. Therefore, it is difficult to increase the silver concentration in the paste, and as a result The electrical resistance of the conductor was high. In contrast, the silver powder proposed by the present invention has a relatively large particle size and a uniform particle size, so that the silver concentration in the silver paste can be increased, and the electrical resistance is more uniform. Lower sintered conductors can be formed.
- the silver powder according to this embodiment (hereinafter referred to as “main silver powder”) has a D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope image (SEM) of 2.50 ⁇ m to 7.50 ⁇ m. Yes, the relationship between D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”) and D90 (referred to as “ SEM D90”) obtained by image analysis of a scanning electron microscope image (SEM) Silver powder characterized by the formula: ( SEM D90- SEM D10) / SEM D50 ⁇ 0.50.
- SEM D10 scanning electron microscope image
- SEM D50 scanning electron microscope image
- SEM D90 scanning electron microscope image
- the present silver powder includes both wet silver powder prepared by a wet method and silver powder prepared by a dry method. Among these, wet silver powder is preferable.
- a characteristic of wet silver powder is that small crystallites gather to form one particle, and therefore, the shrinkage rate at 500 ° C. in TMA measurement is larger than that of silver powder produced by a dry method. If the present silver powder is a wet silver powder, the shrinkage at 500 ° C. in the TMA measurement is 1.0 to 23.0%, particularly 3.0% or more or 23.0% or less, and preferably 5.0% or more. Or it becomes 23.0% or less.
- the shrinkage rate in the above TMA measurement can be measured as follows. Using 0.2 g of silver powder (sample), a weight of 493 kg was applied and molded into a cylindrical shape of ⁇ 3.8 mm. Using a thermomechanical analyzer (TMA) (EXSTAR6000TMA / SS6200) manufactured by Iko Instruments Co., Ltd., the linear shrinkage rate (%) in the longitudinal direction of this molded body was increased by 20 ° C./min in an Air atmosphere while applying a load of 98 mN. The heat shrinkage rate (%) at 500 ° C. can be determined by measuring at a temperature rate.
- TMA thermomechanical analyzer
- the wet method it is possible to produce spherical or substantially spherical particles having a large particle size. Even with the dry method, it is possible to produce spherical particles by the atomizing method or the PVD method, but it is difficult to produce true spherical particles by the atomizing method, and a true sphere is obtained by the PVD method. Even so, it is difficult to produce particles as large as the present invention defines.
- D50 D50
- SEM D50 D50 obtained by image analysis of a scanning electron microscope (SEM) image
- SEM scanning electron microscope
- the SEM D50 of the present silver powder is 2.50 ⁇ m or more, the amount of the resin can be reduced at the time of preparing the paste, and as a result, the electric resistance of the formed sintered conductor can be lowered.
- SEM D50 is 7.50 micrometers or less, it can manufacture comparatively stably. Therefore, from this viewpoint, the SEM D50 of the present silver powder is more preferably 3.00 ⁇ m or more, or 6.50 ⁇ m or less, and particularly preferably 3.00 ⁇ m or more, or 5.50 ⁇ m or less.
- D10 particles size distribution
- SEM D50 D50
- SEM D90 D90
- D10 means the particle size of a number-based cumulative frequency of 10% in the particle size distribution obtained by image analysis of a scanning electron microscope (SEM) image
- D50 is the particle size of the number-based cumulative frequency of 50%
- D90 means the particle size of the number-based cumulative frequency of 90%.
- the particle size distribution is uniform and not only can a homogeneous conductive paste be formed, but also in a short time at a certain temperature range. Can be sintered. From this viewpoint, the value of ( SEM D90- SEM D10) / SEM D50 is preferably 0.20 or more or 0.44 or less, and more preferably 0.20 or more or 0.40 or less.
- the present invention increases the dissolved oxygen in the reducing agent solution used for the reduction reaction, and reacts the silver raw material solution, the reducing agent solution and other additives in a stationary state, thereby increasing the particle size.
- the liquid composition of the reducing agent solution is in a homogeneous and calm state, and as a result, the particle size to be reduced and precipitated can be made uniform, and the wet silver powder having a large primary particle size and a uniform particle size can be obtained. Obtainable.
- a complexing agent is added to a silver aqueous solution such as silver nitrate, and a stearic acid salt such as Na or K stearate is added and stirred as necessary. Then, a reducing agent solution with an increased amount of dissolved oxygen is added, and then necessary.
- the silver powder can be reduced and precipitated by adding a dispersing agent and reacting while stirring, and then the silver powder can be obtained through steps such as filtration, washing and drying.
- the reducing agent solution is prepared by adding a reducing agent (hydrazine) to pure water. At that time, depending on the time from adding the reducing agent (hydrazine) to pure water until adding to the silver aqueous solution.
- the amount of dissolved oxygen in the reducing agent solution can be adjusted. That is, when a reducing agent (hydrazine) is added to pure water, the dissolved oxygen originally contained in the pure water is consumed by the reducing action of the reducing agent (hydrazine) and decreases with time. It is preferable to add to the silver solution in as short a time as possible after adding hydrazine). However, the amount of dissolved oxygen in the solution may be increased by bubbling pure water.
- an aqueous solution containing silver nitrate, a silver salt complex, and a silver intermediate or a slurry can be used as the aqueous silver solution such as silver nitrate.
- complexing agents include ammonia water, ammonium salts, chelate compounds and the like.
- ascorbic acid, sulfite, alkanolamine, hydrogen peroxide formic acid, ammonium formate, sodium formate, glyoxal, tartaric acid, sodium hypophosphite, borohydride metal salt, dimethylamine borane, hydrazine, hydrazine compound And aqueous solutions containing hydroquinone, pyrogallol, glucose, gallic acid, formalin, anhydrous sodium sulfite, Rongalite and the like.
- the dispersant include fatty acids, fatty acid salts, surfactants, organic metals, chelating agents, protective colloids and the like.
- the present silver powder can be used as it is, it can also be used after the present silver powder has been processed into a shape.
- a spherical particle powder (powder consisting of 80% or more of spherical particles) is mechanically processed into non-spherical particle powders such as flakes, scales, and flat plates (: 80% or more of non-spherical particles) Powder).
- flaky particle powder (: 80% or more from flaky particles) is mechanically flattened (rolled or stretched) using a bead mill, ball mill, attritor, vibration mill or the like. Shape powder).
- a fatty acid such as stearic acid or an auxiliary agent such as a surfactant.
- an auxiliary agent such as a surfactant.
- the present silver powder has a uniform particle size, a medium suitable for the particle size can be effectively selected, so that even flake powder can obtain uniform flake powder particles.
- a mixed powder of spherical powder and flake powder may be used.
- the silver powder is suitable as a silver powder for a conductive paste, particularly for a sintered conductive paste.
- the sintered conductive paste can be prepared, for example, by mixing the present silver powder together with glass frit in an organic vehicle.
- the glass frit include lead-free glass such as lead borosilicate glass and zinc borosilicate.
- a resin binder arbitrary resin binders can be used, for example. For example, it is desirable to employ a composition containing at least one selected from an epoxy resin, a polyester resin, a silicon resin, a urea resin, an acrylic resin, and a cellulose resin.
- SEM D10, SEM D50, SEM D90 A scanning electron microscope (SEM) image of any three fields of view taken at 1000 to 3000 times using a scanning electron microscope (SEM) (XL30 manufactured by PHILIPS) is converted into a BMP file and manufactured by Asahi Engineering Co., Ltd.
- A-image PC which is an integrated application of IP-1000PC, performs circular particle analysis with circularity threshold 50, overlap 30 and sample number 150-350, and SEM D10, SEM D50, SEM D90 are manually corrected Measured without applying.
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring. Next, 6 mL of a 1% concentration amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 6.00 to 8.00 mg / L.
- a 1% concentration amine-based dispersant average molecular weight 10,000
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring. Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to a silver ammine complex aqueous solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 6.00 to 8.00 mg / L.
- a 1% strength amine-based dispersant average molecular weight 10,000
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water to prepare a silver nitrate aqueous solution, adding 50 mL of ammonia water having a concentration of 25% by mass and stirring. Next, 1 L of a 11.9 g / L hydrazine aqueous solution adjusted to a dissolved oxygen concentration of 6.00 to 8.00 mg / L and 48 mL of a 5 g / L gelatin aqueous solution adjusted to a silver ammine complex aqueous solution at 20 ° C. (to 1 mol of silver).
- the mixture was reacted without stirring to reduce and precipitate silver particles. Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 ⁇ S / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring. Next, 6 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 3.00 to 5.00 mg / L.
- a 1% strength amine-based dispersant average molecular weight 10,000
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring. Next, 6 mL of a 1% concentration amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 0.20 to 2.00 mg / L.
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring. Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 3.00 to 5.00 mg / L.
- a 1% strength amine-based dispersant average molecular weight 10,000
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring. Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 0.20 to 2.00 mg / L.
- a 1% strength amine-based dispersant average molecular weight 10,000
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
- a silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water to prepare a silver nitrate aqueous solution, adding 50 mL of ammonia water having a concentration of 25% by mass and stirring. Next, in a silver ammine complex aqueous solution at 20 ° C., 1 L of a 11.9 g / L hydrazine aqueous solution adjusted to a dissolved oxygen concentration of 0.20 to 2.00 mg / L and 48 mL of a gelatin aqueous solution of 5 g / L concentration (into 1 mol of silver).
- the silver powder of the examples is larger than the silver powder of the comparative example and the conventionally known silver powder, the particle size is uniform, so if a silver paste is produced using this, the silver concentration is increased. It is possible to form a sintered conductor that is homogeneous and has a lower electrical resistance. From this point of view, in this silver powder, SEM D50 is 2.50 ⁇ m ⁇ 7.50 ⁇ m, and can be considered as preferably a (SEM D90- SEM D10) / SEM D50 ⁇ 0.50 .
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Abstract
Provided is a novel silver powder which can enhance the silver concentration of a silver paste and which can form a homogeneous sintered conductor having a lower electric resistance. Proposed is a silver powder characterized in that: the SEMD50 of the powder is 2.50 to 7.50μm; and the SEMD10, SEMD50 and SEMD90 of the powder satisfy the relationship (SEMD90- SEMD10)/SEMD50 ≤ 0.50. The term "SEMD10" "SEMD50" and "SEMD90" refer respectively to D10, D50 and D90 as determined by image analysis with a scanning electron microscope (SEM).
Description
本発明は、焼結型導電性ペーストに好適に用いることができる銀粉に関する。
The present invention relates to a silver powder that can be suitably used for a sintered conductive paste.
導電性ペーストは、樹脂系バインダーと溶媒からなるビヒクル中に導電フィラーを分散させた流動性組成物であり、電気回路の形成や、セラミックコンデンサの外部電極の形成などに広く用いられている。この種の導電性ペーストには、樹脂の硬化によって導電性フィラーが圧着され導通を確保する樹脂硬化型と、高温焼結によって有機成分が揮発し導電性フィラーが焼結して導通を確保する焼結型とがある。
The conductive paste is a fluid composition in which a conductive filler is dispersed in a vehicle composed of a resin binder and a solvent, and is widely used for forming an electric circuit, an external electrode of a ceramic capacitor, and the like. This type of conductive paste includes a resin-curing type in which conductive fillers are pressure-bonded by hardening of the resin to ensure conduction, and a sintered type in which organic components are volatilized by high-temperature sintering and the conductive filler is sintered to ensure conduction. There is a type.
このうちの焼結型導電性ペーストは、一般に導電フィラー（金属粉末）とガラスフリットとを有機ビヒクル中に分散させてなるペースト状組成物であり、４００～８００℃にて焼結することにより、有機ビヒクルが揮発し、さらに導電フィラーが焼結することによって導通性を確保するものである。この際、ガラスフリットは、この導電膜を基板に接着させる作用を有し、有機ビヒクルは、金属粉末およびガラスフリットを印刷可能にするための有機液体媒体として作用する。
Of these, the sintered conductive paste is generally a paste-like composition in which a conductive filler (metal powder) and glass frit are dispersed in an organic vehicle. By sintering at 400 to 800 ° C., The organic vehicle volatilizes and the conductive filler is sintered to ensure conductivity. At this time, the glass frit has a function of adhering the conductive film to the substrate, and the organic vehicle functions as an organic liquid medium for enabling printing of the metal powder and the glass frit.
このような焼結型導電性ペーストに用いる銀粉については、従来、電極や回路のファインライン化に対応すべく、微粒で且つシャープな粒度分布を有する銀粉が一般的に求められるため、それに対応した新たな技術が提案されている。
また、この種の銀粉には、乾式法で作製された乾式銀粉と湿式法で作製された湿式銀粉とがあるが、湿式銀粉は、小さな結晶が集まって一つの粒子を形成するため、乾式銀粉に比べて、焼成温度が低いという特徴がある。 For silver powder used in such a sintered conductive paste, conventionally, silver powder having a fine particle size and sharp particle size distribution is generally required in order to cope with fine lines of electrodes and circuits. New technologies have been proposed.
In addition, this type of silver powder includes a dry silver powder produced by a dry method and a wet silver powder produced by a wet method, but the wet silver powder is a dry silver powder because small crystals gather to form one particle. Compared to the above, the firing temperature is low.
また、この種の銀粉には、乾式法で作製された乾式銀粉と湿式法で作製された湿式銀粉とがあるが、湿式銀粉は、小さな結晶が集まって一つの粒子を形成するため、乾式銀粉に比べて、焼成温度が低いという特徴がある。 For silver powder used in such a sintered conductive paste, conventionally, silver powder having a fine particle size and sharp particle size distribution is generally required in order to cope with fine lines of electrodes and circuits. New technologies have been proposed.
In addition, this type of silver powder includes a dry silver powder produced by a dry method and a wet silver powder produced by a wet method, but the wet silver powder is a dry silver powder because small crystals gather to form one particle. Compared to the above, the firing temperature is low.
そこで湿式銀粉に関し、従来、例えば特許文献１において、微粒の銀粉であって、しかも粉粒の凝集の少ない単分散により近い分散性を備える微粒銀粉として、走査型電子顕微鏡像の画像解析により得られる一次粒子の平均粒径ＤＩＡが０．６μｍ以下であり、前記一次粒子の平均粒径ＤＩＡと、レーザー回折散乱式粒度分布測定法による平均粒径Ｄ５０とを用いてＤ５０／ＤＩＡで表される凝集度が１．５以下であり、結晶子径が１０ｎｍ以下であり、有機不純物含有量が炭素量換算で０．２５ｗｔ％以下である微粒銀粉が提案されている。
Thus, regarding wet silver powder, conventionally, for example, in Patent Document 1, it is obtained by image analysis of a scanning electron microscopic image as fine silver powder, which is fine silver powder having dispersibility close to monodispersion with little aggregation of powder particles. The average particle diameter D IA of the primary particles is 0.6 μm or less, and the average particle diameter D IA of the primary particles and the average particle diameter D 50 by the laser diffraction scattering type particle size distribution measurement method are used to obtain D 50 / D IA A fine silver powder having a cohesion degree of 1.5 or less, a crystallite diameter of 10 nm or less, and an organic impurity content of 0.25 wt% or less in terms of carbon amount has been proposed.
また、特許文献２には、平均粒径が０．１μｍ以上、１μｍ未満であり、粒度分布がシャープでかつ高分散性の球状銀粉として、レーザー回折法により測定した累積１０質量％粒径をＤ１０、累積５０質量％粒径をＤ５０、累積９０質量％粒径をＤ９０と表記し、走査型電子顕微鏡像の画像解析から得られる一次粒子の平均粒径をＤＳＥＭと表記したとき、Ｄ５０が０．１μｍ以上、１μｍ未満、且つ、Ｄ５０／ＤＳＥＭの値が１．３以下、且つ、（Ｄ９０－Ｄ１０）／Ｄ５０の値が０．８以下であることを特徴とする球状銀粉が提案されている。
Further, Patent Document 2 discloses a cumulative 10% by mass particle size measured by laser diffraction method as a spherical silver powder having an average particle size of 0.1 μm or more and less than 1 μm, sharp particle size distribution and high dispersibility. When the cumulative 50 mass% particle diameter is expressed as D50, the cumulative 90 mass% particle diameter is expressed as D90, and the average particle diameter of the primary particles obtained from the image analysis of the scanning electron microscope image is expressed as DSEM, D50 is 0.00. There has been proposed a spherical silver powder characterized by having a value of 1 μm or more and less than 1 μm, a D50 / DSEM value of 1.3 or less, and a (D90-D10) / D50 value of 0.8 or less.
導電性ペーストを用いて電極や回路などの焼結導体を形成する際、均質で且つ、電気抵抗がより一層低い焼結導体を形成することは重要な課題の一つであり、そのための手段として、銀ペースト中の銀濃度を高くする方法が考えられる。
そこで本発明は、銀ペースト中の銀濃度を高くすることができ、均質で且つ、電気抵抗がより一層低い焼結導体を形成することができる、新たな銀粉を提供せんとするものである。 When forming sintered conductors such as electrodes and circuits using conductive paste, it is one of the important issues to form a sintered conductor that is homogeneous and has a lower electrical resistance. A method of increasing the silver concentration in the silver paste can be considered.
Therefore, the present invention is to provide a new silver powder that can increase the silver concentration in the silver paste, can form a sintered conductor that is homogeneous and has a lower electrical resistance.
そこで本発明は、銀ペースト中の銀濃度を高くすることができ、均質で且つ、電気抵抗がより一層低い焼結導体を形成することができる、新たな銀粉を提供せんとするものである。 When forming sintered conductors such as electrodes and circuits using conductive paste, it is one of the important issues to form a sintered conductor that is homogeneous and has a lower electrical resistance. A method of increasing the silver concentration in the silver paste can be considered.
Therefore, the present invention is to provide a new silver powder that can increase the silver concentration in the silver paste, can form a sintered conductor that is homogeneous and has a lower electrical resistance.
本発明は、走査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ５０（「ＳＥＭＤ５０」と称する）が２．５０μｍ～７．５０μｍであり、走査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ１０（「ＳＥＭＤ１０」と称する）、Ｄ５０（「ＳＥＭＤ５０」と称する）及びＤ９０（「ＳＥＭＤ９０」と称する）の関係が、関係式：（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０で示されることを特徴とする銀粉を提案する。
In the present invention, D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope image (SEM) is 2.50 μm to 7.50 μm, and image analysis of a scanning electron microscope image (SEM) The relationship between the obtained D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”) and D90 (referred to as “ SEM D90”) is the relational expression: ( SEM D90- SEM D10) / SEM D50 ≦ 0 A silver powder characterized by .50 is proposed.
本発明が提案する銀粉は、銀ペースト中の銀濃度を高くすることができ、均質で且つ、電気抵抗がより一層低い焼結導体を形成することができる。
従来の銀粉粒子は、微粒子を多く含むため、総じて比表面積が大きく、銀ペーストを調製する際には多量の樹脂が必要となり、そのため、ペースト中の銀濃度を高めることが難しく、その結果として焼結導体の電気抵抗が高くなってしまっていた。これに対し、本発明が提案する銀粉は、比較的大粒径でありながら、粒径が揃っているため、銀ペースト中の銀濃度を高くすることができ、均質で且つ、電気抵抗がより一層低い焼結導体を形成することができる。 The silver powder proposed by the present invention can increase the silver concentration in the silver paste, and can form a sintered conductor that is homogeneous and has an even lower electrical resistance.
Since conventional silver powder particles contain a large amount of fine particles, the specific surface area is generally large, and a large amount of resin is required when preparing a silver paste. Therefore, it is difficult to increase the silver concentration in the paste, and as a result The electrical resistance of the conductor was high. In contrast, the silver powder proposed by the present invention has a relatively large particle size and a uniform particle size, so that the silver concentration in the silver paste can be increased, and the electrical resistance is more uniform. Lower sintered conductors can be formed.
従来の銀粉粒子は、微粒子を多く含むため、総じて比表面積が大きく、銀ペーストを調製する際には多量の樹脂が必要となり、そのため、ペースト中の銀濃度を高めることが難しく、その結果として焼結導体の電気抵抗が高くなってしまっていた。これに対し、本発明が提案する銀粉は、比較的大粒径でありながら、粒径が揃っているため、銀ペースト中の銀濃度を高くすることができ、均質で且つ、電気抵抗がより一層低い焼結導体を形成することができる。 The silver powder proposed by the present invention can increase the silver concentration in the silver paste, and can form a sintered conductor that is homogeneous and has an even lower electrical resistance.
Since conventional silver powder particles contain a large amount of fine particles, the specific surface area is generally large, and a large amount of resin is required when preparing a silver paste. Therefore, it is difficult to increase the silver concentration in the paste, and as a result The electrical resistance of the conductor was high. In contrast, the silver powder proposed by the present invention has a relatively large particle size and a uniform particle size, so that the silver concentration in the silver paste can be increased, and the electrical resistance is more uniform. Lower sintered conductors can be formed.
次に、実施の形態例に基づいて本発明を説明するが、本発明が次に説明する実施形態に限定されるものではない。
Next, the present invention will be described based on the embodiments, but the present invention is not limited to the embodiments described below.
＜本銀粉＞
本実施形態に係る銀粉（以下、「本銀粉」と称する）は、査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ５０（「ＳＥＭＤ５０」と称する）が２．５０μｍ～７．５０μｍであり、走査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ１０（「ＳＥＭＤ１０」と称する）、Ｄ５０（「ＳＥＭＤ５０」と称する）及びＤ９０（「ＳＥＭＤ９０」と称する）の関係が、関係式：（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０で示されることを特徴とする銀粉である。
以下、本銀粉の特徴について説明する。 <Silver powder>
The silver powder according to this embodiment (hereinafter referred to as “main silver powder”) has a D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope image (SEM) of 2.50 μm to 7.50 μm. Yes, the relationship between D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”) and D90 (referred to as “ SEM D90”) obtained by image analysis of a scanning electron microscope image (SEM) Silver powder characterized by the formula: ( SEM D90- SEM D10) / SEM D50 ≦ 0.50.
Hereinafter, features of the present silver powder will be described.
本実施形態に係る銀粉（以下、「本銀粉」と称する）は、査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ５０（「ＳＥＭＤ５０」と称する）が２．５０μｍ～７．５０μｍであり、走査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ１０（「ＳＥＭＤ１０」と称する）、Ｄ５０（「ＳＥＭＤ５０」と称する）及びＤ９０（「ＳＥＭＤ９０」と称する）の関係が、関係式：（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０で示されることを特徴とする銀粉である。
以下、本銀粉の特徴について説明する。 <Silver powder>
The silver powder according to this embodiment (hereinafter referred to as “main silver powder”) has a D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope image (SEM) of 2.50 μm to 7.50 μm. Yes, the relationship between D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”) and D90 (referred to as “ SEM D90”) obtained by image analysis of a scanning electron microscope image (SEM) Silver powder characterized by the formula: ( SEM D90- SEM D10) / SEM D50 ≦ 0.50.
Hereinafter, features of the present silver powder will be described.
（湿式銀粉）
本銀粉は、湿式法で作製される湿式銀粉、乾式法で作製される銀粉のいずれも包含する。中でも、湿式銀粉であるのが好ましい。
湿式銀粉の特徴は、小さな結晶子が集まって一つの粒子を形成するため、乾式法で作製される銀粉に比べて、ＴＭＡ測定における５００℃での収縮率が大きいという特徴がある。本銀粉が湿式銀粉であれば、ＴＭＡ測定における５００℃での収縮は１．０～２３．０％、中でも３．０％以上或いは２３．０％以下となり、その中でも好ましくは５．０％以上或いは２３．０％以下となる。 (Wet silver powder)
The present silver powder includes both wet silver powder prepared by a wet method and silver powder prepared by a dry method. Among these, wet silver powder is preferable.
A characteristic of wet silver powder is that small crystallites gather to form one particle, and therefore, the shrinkage rate at 500 ° C. in TMA measurement is larger than that of silver powder produced by a dry method. If the present silver powder is a wet silver powder, the shrinkage at 500 ° C. in the TMA measurement is 1.0 to 23.0%, particularly 3.0% or more or 23.0% or less, and preferably 5.0% or more. Or it becomes 23.0% or less.
本銀粉は、湿式法で作製される湿式銀粉、乾式法で作製される銀粉のいずれも包含する。中でも、湿式銀粉であるのが好ましい。
湿式銀粉の特徴は、小さな結晶子が集まって一つの粒子を形成するため、乾式法で作製される銀粉に比べて、ＴＭＡ測定における５００℃での収縮率が大きいという特徴がある。本銀粉が湿式銀粉であれば、ＴＭＡ測定における５００℃での収縮は１．０～２３．０％、中でも３．０％以上或いは２３．０％以下となり、その中でも好ましくは５．０％以上或いは２３．０％以下となる。 (Wet silver powder)
The present silver powder includes both wet silver powder prepared by a wet method and silver powder prepared by a dry method. Among these, wet silver powder is preferable.
A characteristic of wet silver powder is that small crystallites gather to form one particle, and therefore, the shrinkage rate at 500 ° C. in TMA measurement is larger than that of silver powder produced by a dry method. If the present silver powder is a wet silver powder, the shrinkage at 500 ° C. in the TMA measurement is 1.0 to 23.0%, particularly 3.0% or more or 23.0% or less, and preferably 5.0% or more. Or it becomes 23.0% or less.
このとき、上記のＴＭＡ測定における収縮率は次のように測定することができる。
銀粉（サンプル）０．２ｇを用い、４９３ｋｇの加重をかけてφ３．８ｍｍの円柱状に成形した。この成形体の縦方向の線収縮率（％）を、イコーインスツルメンツ社製の熱機械分析装置（ＴＭＡ）（ＥＸＳＴＡＲ６０００ＴＭＡ／ＳＳ６２００）を用い、９８ｍＮの加重をかけながらＡｉｒ雰囲気中２０℃／分の昇温速度で測定し、５００℃における熱収縮率（％）を求めることができる。 At this time, the shrinkage rate in the above TMA measurement can be measured as follows.
Using 0.2 g of silver powder (sample), a weight of 493 kg was applied and molded into a cylindrical shape of φ3.8 mm. Using a thermomechanical analyzer (TMA) (EXSTAR6000TMA / SS6200) manufactured by Iko Instruments Co., Ltd., the linear shrinkage rate (%) in the longitudinal direction of this molded body was increased by 20 ° C./min in an Air atmosphere while applying a load of 98 mN. The heat shrinkage rate (%) at 500 ° C. can be determined by measuring at a temperature rate.
銀粉（サンプル）０．２ｇを用い、４９３ｋｇの加重をかけてφ３．８ｍｍの円柱状に成形した。この成形体の縦方向の線収縮率（％）を、イコーインスツルメンツ社製の熱機械分析装置（ＴＭＡ）（ＥＸＳＴＡＲ６０００ＴＭＡ／ＳＳ６２００）を用い、９８ｍＮの加重をかけながらＡｉｒ雰囲気中２０℃／分の昇温速度で測定し、５００℃における熱収縮率（％）を求めることができる。 At this time, the shrinkage rate in the above TMA measurement can be measured as follows.
Using 0.2 g of silver powder (sample), a weight of 493 kg was applied and molded into a cylindrical shape of φ3.8 mm. Using a thermomechanical analyzer (TMA) (EXSTAR6000TMA / SS6200) manufactured by Iko Instruments Co., Ltd., the linear shrinkage rate (%) in the longitudinal direction of this molded body was increased by 20 ° C./min in an Air atmosphere while applying a load of 98 mN. The heat shrinkage rate (%) at 500 ° C. can be determined by measuring at a temperature rate.
また、湿式法によれば、真球状或いは略真球状の粒子であって、且つ大粒径のものを作製することができる。乾式法であっても、アトマイズ法或いはＰＶＤ法によって球状の粒子を作製することは可能であるが、アトマイズ法では真球粒子を作製することは困難であるし、ＰＶＤ法では、真球が得られても、本発明が規定するほど大きな粒子を作製することは困難である。
In addition, according to the wet method, it is possible to produce spherical or substantially spherical particles having a large particle size. Even with the dry method, it is possible to produce spherical particles by the atomizing method or the PVD method, but it is difficult to produce true spherical particles by the atomizing method, and a true sphere is obtained by the PVD method. Even so, it is difficult to produce particles as large as the present invention defines.
（Ｄ５０）
本銀粉においては、走査型電子顕微鏡（ＳＥＭ）像の画像解析により得られるＤ５０（「ＳＥＭＤ５０」と称する）が２．５０μｍ～７．５０μｍであることが重要である。
本銀粉のＳＥＭＤ５０が２．５０μｍ以上であれば、ペースト調製時に樹脂の量を減らすことができ、その結果として形成した焼結導体の電気抵抗を低くすることができる。また、ＳＥＭＤ５０が７．５０μｍ以下であれば比較的安定的に製造できる。
よって、かかる観点から、本銀粉のＳＥＭＤ５０は、特に３．００μｍ以上、或いは６．５０μｍ以下、中でも３．００μｍ以上、或いは、５．５０μｍ以下であるのがより一層好ましい。 (D50)
In the present silver powder, it is important that D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope (SEM) image is 2.50 μm to 7.50 μm.
If the SEM D50 of the present silver powder is 2.50 μm or more, the amount of the resin can be reduced at the time of preparing the paste, and as a result, the electric resistance of the formed sintered conductor can be lowered. Moreover, if SEM D50 is 7.50 micrometers or less, it can manufacture comparatively stably.
Therefore, from this viewpoint, the SEM D50 of the present silver powder is more preferably 3.00 μm or more, or 6.50 μm or less, and particularly preferably 3.00 μm or more, or 5.50 μm or less.
本銀粉においては、走査型電子顕微鏡（ＳＥＭ）像の画像解析により得られるＤ５０（「ＳＥＭＤ５０」と称する）が２．５０μｍ～７．５０μｍであることが重要である。
本銀粉のＳＥＭＤ５０が２．５０μｍ以上であれば、ペースト調製時に樹脂の量を減らすことができ、その結果として形成した焼結導体の電気抵抗を低くすることができる。また、ＳＥＭＤ５０が７．５０μｍ以下であれば比較的安定的に製造できる。
よって、かかる観点から、本銀粉のＳＥＭＤ５０は、特に３．００μｍ以上、或いは６．５０μｍ以下、中でも３．００μｍ以上、或いは、５．５０μｍ以下であるのがより一層好ましい。 (D50)
In the present silver powder, it is important that D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope (SEM) image is 2.50 μm to 7.50 μm.
If the SEM D50 of the present silver powder is 2.50 μm or more, the amount of the resin can be reduced at the time of preparing the paste, and as a result, the electric resistance of the formed sintered conductor can be lowered. Moreover, if SEM D50 is 7.50 micrometers or less, it can manufacture comparatively stably.
Therefore, from this viewpoint, the SEM D50 of the present silver powder is more preferably 3.00 μm or more, or 6.50 μm or less, and particularly preferably 3.00 μm or more, or 5.50 μm or less.
（粒度分布）
本銀粉においては、走査型電子顕微鏡（ＳＥＭ）像の画像解析により得られるＤ１０（「ＳＥＭＤ１０」と称する）、Ｄ５０（「ＳＥＭＤ５０」と称する）及びＤ９０（「ＳＥＭＤ９０」と称する）の関係が、関係式：（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０で示されることが重要である。 (Particle size distribution)
In the present silver powder, D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”), and D90 (referred to as “ SEM D90”) obtained by image analysis of a scanning electron microscope (SEM) image. However, it is important that the relationship is expressed by the relational expression: ( SEM D90− SEM D10) / SEM D50 ≦ 0.50.
本銀粉においては、走査型電子顕微鏡（ＳＥＭ）像の画像解析により得られるＤ１０（「ＳＥＭＤ１０」と称する）、Ｄ５０（「ＳＥＭＤ５０」と称する）及びＤ９０（「ＳＥＭＤ９０」と称する）の関係が、関係式：（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０で示されることが重要である。 (Particle size distribution)
In the present silver powder, D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”), and D90 (referred to as “ SEM D90”) obtained by image analysis of a scanning electron microscope (SEM) image. However, it is important that the relationship is expressed by the relational expression: ( SEM D90− SEM D10) / SEM D50 ≦ 0.50.
ここで、Ｄ１０は、走査型電子顕微鏡（ＳＥＭ）像の画像解析により得られる粒度分布における個数基準累積度数１０％の粒子径の意味であり、Ｄ５０は、当該個数基準累積度数５０％の粒子径の意味であり、Ｄ９０は、当該個数基準累積度数９０％の粒子径の意味である。
Here, D10 means the particle size of a number-based cumulative frequency of 10% in the particle size distribution obtained by image analysis of a scanning electron microscope (SEM) image, and D50 is the particle size of the number-based cumulative frequency of 50%. D90 means the particle size of the number-based cumulative frequency of 90%.
（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０の値が０．５０以下であれば、粒度分布が揃っており、均質な導電性ペーストを形成することができるばかりか、ある温度域で短時間のうちに焼結させることができる。かかる観点から、（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０の値は０．２０以上或いは０．４４以下であるのが好ましく、中でも０．２０以上或いは０．４０以下であるのがより一層好ましい。
If the value of ( SEM D90- SEM D10) / SEM D50 is 0.50 or less, the particle size distribution is uniform and not only can a homogeneous conductive paste be formed, but also in a short time at a certain temperature range. Can be sintered. From this viewpoint, the value of ( SEM D90- SEM D10) / SEM D50 is preferably 0.20 or more or 0.44 or less, and more preferably 0.20 or more or 0.40 or less.
ただし、微粒子や粗粒子が若干含まれていても、効果に影響は少ないため、おおまかに見て粒度が揃っていればよい。その意味で（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０の値が０．５０以下であれば、微粒子や粗粒子が含まれていてもよい。
また、（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０の分布が、一つの頂点と両側になめらかな裾野を有する単峰性ピークを示すものであり、分級によって区切られる分布とは区別されるものである。 However, even if some fine particles and coarse particles are included, the effect is small, and it is sufficient that the particle sizes are roughly uniform. In that sense, if the value of ( SEM D90- SEM D10) / SEM D50 is 0.50 or less, fine particles and coarse particles may be included.
In addition, the distribution of ( SEM D90- SEM D10) / SEM D50 shows a unimodal peak having one apex and a smooth skirt on both sides, and is distinguished from the distribution divided by classification. .
また、（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０の分布が、一つの頂点と両側になめらかな裾野を有する単峰性ピークを示すものであり、分級によって区切られる分布とは区別されるものである。 However, even if some fine particles and coarse particles are included, the effect is small, and it is sufficient that the particle sizes are roughly uniform. In that sense, if the value of ( SEM D90- SEM D10) / SEM D50 is 0.50 or less, fine particles and coarse particles may be included.
In addition, the distribution of ( SEM D90- SEM D10) / SEM D50 shows a unimodal peak having one apex and a smooth skirt on both sides, and is distinguished from the distribution divided by classification. .
＜製法＞
次に、本銀粉の好ましい製造方法として、湿式法による具体的な製造方法について説明する。但し、上述のように湿式法に限定するものではない。 <Production method>
Next, a specific manufacturing method by a wet method will be described as a preferable manufacturing method of the present silver powder. However, it is not limited to the wet method as described above.
次に、本銀粉の好ましい製造方法として、湿式法による具体的な製造方法について説明する。但し、上述のように湿式法に限定するものではない。 <Production method>
Next, a specific manufacturing method by a wet method will be described as a preferable manufacturing method of the present silver powder. However, it is not limited to the wet method as described above.
従来の湿式還元法で大粒径の銀粉を製造しようとすると、還元反応をゆっくりと進行させ、粒子を成長させる過程が必要であった。しかし、そのようにすると、小粒径或いは小粒径の凝集体が混在するようになるためシャープな粒度分布を得ることは困難であった。また、アトマイズ法によって大粒径を製造することは可能であるが、粒子が安定過ぎる為に、焼結温度が高くなり、焼結型導電性ペーストに用いる銀粉としては不向きとなる。さらにまた、分級によって大粒径且つシャープな粒度分布を得ることも可能であるが、生産性が問題であった。
そこで、本発明は、還元反応に用いる還元剤溶液の溶存酸素を高めて、銀原料溶液、還元剤溶液およびその他添加剤を静止した状態で反応させることで、大粒径であり、且つ粒径が揃っている銀粉を得ることに成功した。すなわち、還元剤溶液中の溶存酸素が少ないと、すぐに還元反応が始まって微粒子ができてしまうが、溶存酸素が多ければ、先ず溶存酸素が還元反応するので、銀が反応して還元析出するまでの時間を稼ぐことができる。よって、この間に、還元剤溶液の液組成が均質で落ち着いた状態になり、その結果、還元析出される粒度を揃えることができ、一次粒子の粒径が大きく且つ粒径が揃った湿式銀粉を得ることができる。 In order to produce silver powder having a large particle size by the conventional wet reduction method, a process of slowly proceeding the reduction reaction and growing the particles is necessary. However, in such a case, it is difficult to obtain a sharp particle size distribution because small particles or aggregates with small particles are mixed. Moreover, although it is possible to manufacture a large particle size by the atomizing method, since the particles are too stable, the sintering temperature becomes high, making it unsuitable as a silver powder for use in a sintered conductive paste. Furthermore, it is possible to obtain a large particle size and a sharp particle size distribution by classification, but productivity is a problem.
Therefore, the present invention increases the dissolved oxygen in the reducing agent solution used for the reduction reaction, and reacts the silver raw material solution, the reducing agent solution and other additives in a stationary state, thereby increasing the particle size. We succeeded in obtaining silver powder with That is, if the dissolved oxygen in the reducing agent solution is small, the reduction reaction starts immediately and fine particles are formed. However, if there is a large amount of dissolved oxygen, the dissolved oxygen first undergoes a reduction reaction, so that silver reacts to reduce and precipitate. You can earn time. Therefore, during this time, the liquid composition of the reducing agent solution is in a homogeneous and calm state, and as a result, the particle size to be reduced and precipitated can be made uniform, and the wet silver powder having a large primary particle size and a uniform particle size can be obtained. Obtainable.
そこで、本発明は、還元反応に用いる還元剤溶液の溶存酸素を高めて、銀原料溶液、還元剤溶液およびその他添加剤を静止した状態で反応させることで、大粒径であり、且つ粒径が揃っている銀粉を得ることに成功した。すなわち、還元剤溶液中の溶存酸素が少ないと、すぐに還元反応が始まって微粒子ができてしまうが、溶存酸素が多ければ、先ず溶存酸素が還元反応するので、銀が反応して還元析出するまでの時間を稼ぐことができる。よって、この間に、還元剤溶液の液組成が均質で落ち着いた状態になり、その結果、還元析出される粒度を揃えることができ、一次粒子の粒径が大きく且つ粒径が揃った湿式銀粉を得ることができる。 In order to produce silver powder having a large particle size by the conventional wet reduction method, a process of slowly proceeding the reduction reaction and growing the particles is necessary. However, in such a case, it is difficult to obtain a sharp particle size distribution because small particles or aggregates with small particles are mixed. Moreover, although it is possible to manufacture a large particle size by the atomizing method, since the particles are too stable, the sintering temperature becomes high, making it unsuitable as a silver powder for use in a sintered conductive paste. Furthermore, it is possible to obtain a large particle size and a sharp particle size distribution by classification, but productivity is a problem.
Therefore, the present invention increases the dissolved oxygen in the reducing agent solution used for the reduction reaction, and reacts the silver raw material solution, the reducing agent solution and other additives in a stationary state, thereby increasing the particle size. We succeeded in obtaining silver powder with That is, if the dissolved oxygen in the reducing agent solution is small, the reduction reaction starts immediately and fine particles are formed. However, if there is a large amount of dissolved oxygen, the dissolved oxygen first undergoes a reduction reaction, so that silver reacts to reduce and precipitate. You can earn time. Therefore, during this time, the liquid composition of the reducing agent solution is in a homogeneous and calm state, and as a result, the particle size to be reduced and precipitated can be made uniform, and the wet silver powder having a large primary particle size and a uniform particle size can be obtained. Obtainable.
ここで、本銀粉の製造方法の具体的な一例について説明する。
先ず、硝酸銀などの銀水溶液に錯化剤を加え、必要に応じてステアリン酸ＮａやＫなどのステアリン酸塩を加えて撹拌した後、溶存酸素量を高めた還元剤溶液を添加し、次いで必要に応じて分散剤を添加して撹拌させながら反応させて銀粒子を還元析出させ、その後、ろ過、洗浄、乾燥などの工程を経て、本銀粉を得ることができる。 Here, the specific example of the manufacturing method of this silver powder is demonstrated.
First, a complexing agent is added to a silver aqueous solution such as silver nitrate, and a stearic acid salt such as Na or K stearate is added and stirred as necessary. Then, a reducing agent solution with an increased amount of dissolved oxygen is added, and then necessary. Depending on the case, the silver powder can be reduced and precipitated by adding a dispersing agent and reacting while stirring, and then the silver powder can be obtained through steps such as filtration, washing and drying.
先ず、硝酸銀などの銀水溶液に錯化剤を加え、必要に応じてステアリン酸ＮａやＫなどのステアリン酸塩を加えて撹拌した後、溶存酸素量を高めた還元剤溶液を添加し、次いで必要に応じて分散剤を添加して撹拌させながら反応させて銀粒子を還元析出させ、その後、ろ過、洗浄、乾燥などの工程を経て、本銀粉を得ることができる。 Here, the specific example of the manufacturing method of this silver powder is demonstrated.
First, a complexing agent is added to a silver aqueous solution such as silver nitrate, and a stearic acid salt such as Na or K stearate is added and stirred as necessary. Then, a reducing agent solution with an increased amount of dissolved oxygen is added, and then necessary. Depending on the case, the silver powder can be reduced and precipitated by adding a dispersing agent and reacting while stirring, and then the silver powder can be obtained through steps such as filtration, washing and drying.
ここで、還元剤溶液は、純水に還元剤（ヒドラジン）を添加して調製し、その際に、純水に還元剤（ヒドラジン）を添加してから、銀水溶液に添加するまでの時間によって、還元剤溶液における溶存酸素量の調整を図ることができる。つまり、純水に還元剤（ヒドラジン）を添加すると、もともと純水に含まれている溶存酸素が還元剤（ヒドラジン）による還元作用によって消費されて経過時間とともに少なくなるため、純水に還元剤（ヒドラジン）を添加した後、できるだけ短時間のうちに銀溶液に添加するのが好ましい。
ただし、純水をバブリングするなど、溶液中の溶存酸素量を増加させるようにしてもよい。 Here, the reducing agent solution is prepared by adding a reducing agent (hydrazine) to pure water. At that time, depending on the time from adding the reducing agent (hydrazine) to pure water until adding to the silver aqueous solution. The amount of dissolved oxygen in the reducing agent solution can be adjusted. That is, when a reducing agent (hydrazine) is added to pure water, the dissolved oxygen originally contained in the pure water is consumed by the reducing action of the reducing agent (hydrazine) and decreases with time. It is preferable to add to the silver solution in as short a time as possible after adding hydrazine).
However, the amount of dissolved oxygen in the solution may be increased by bubbling pure water.
ただし、純水をバブリングするなど、溶液中の溶存酸素量を増加させるようにしてもよい。 Here, the reducing agent solution is prepared by adding a reducing agent (hydrazine) to pure water. At that time, depending on the time from adding the reducing agent (hydrazine) to pure water until adding to the silver aqueous solution. The amount of dissolved oxygen in the reducing agent solution can be adjusted. That is, when a reducing agent (hydrazine) is added to pure water, the dissolved oxygen originally contained in the pure water is consumed by the reducing action of the reducing agent (hydrazine) and decreases with time. It is preferable to add to the silver solution in as short a time as possible after adding hydrazine).
However, the amount of dissolved oxygen in the solution may be increased by bubbling pure water.
上記の製法において、硝酸銀などの銀水溶液は、硝酸銀、銀塩錯体、及び銀中間体のいずれかを含有する水溶液、又はスラリーを使用することができる。
また、錯化剤としては、例えばアンモニア水、アンモニウム塩、キレート化合物等を挙げることができる。
還元剤としては、アスコルビン酸、亜硫酸塩、アルカノールアミン、過酸化水素水、ギ酸、ギ酸アンモニウム、ギ酸ナトリウム、グリオキサール、酒石酸、次亜燐酸ナトリウム、水素化ホウ素金属塩、ジメチルアミンボラン、ヒドラジン、ヒドラジン化合物、ヒドロキノン、ピロガロール、ぶどう糖、没食子酸、ホルマリン、無水亜硫酸ナトリウム、ロンガリットなどを含む水溶液を挙げることができる。
分散剤としては、脂肪酸、脂肪酸塩、界面活性剤、有機金属、キレート剤、保護コロイド等を挙げることができる。 In the above production method, an aqueous solution containing silver nitrate, a silver salt complex, and a silver intermediate or a slurry can be used as the aqueous silver solution such as silver nitrate.
Examples of complexing agents include ammonia water, ammonium salts, chelate compounds and the like.
As reducing agents, ascorbic acid, sulfite, alkanolamine, hydrogen peroxide, formic acid, ammonium formate, sodium formate, glyoxal, tartaric acid, sodium hypophosphite, borohydride metal salt, dimethylamine borane, hydrazine, hydrazine compound And aqueous solutions containing hydroquinone, pyrogallol, glucose, gallic acid, formalin, anhydrous sodium sulfite, Rongalite and the like.
Examples of the dispersant include fatty acids, fatty acid salts, surfactants, organic metals, chelating agents, protective colloids and the like.
また、錯化剤としては、例えばアンモニア水、アンモニウム塩、キレート化合物等を挙げることができる。
還元剤としては、アスコルビン酸、亜硫酸塩、アルカノールアミン、過酸化水素水、ギ酸、ギ酸アンモニウム、ギ酸ナトリウム、グリオキサール、酒石酸、次亜燐酸ナトリウム、水素化ホウ素金属塩、ジメチルアミンボラン、ヒドラジン、ヒドラジン化合物、ヒドロキノン、ピロガロール、ぶどう糖、没食子酸、ホルマリン、無水亜硫酸ナトリウム、ロンガリットなどを含む水溶液を挙げることができる。
分散剤としては、脂肪酸、脂肪酸塩、界面活性剤、有機金属、キレート剤、保護コロイド等を挙げることができる。 In the above production method, an aqueous solution containing silver nitrate, a silver salt complex, and a silver intermediate or a slurry can be used as the aqueous silver solution such as silver nitrate.
Examples of complexing agents include ammonia water, ammonium salts, chelate compounds and the like.
As reducing agents, ascorbic acid, sulfite, alkanolamine, hydrogen peroxide, formic acid, ammonium formate, sodium formate, glyoxal, tartaric acid, sodium hypophosphite, borohydride metal salt, dimethylamine borane, hydrazine, hydrazine compound And aqueous solutions containing hydroquinone, pyrogallol, glucose, gallic acid, formalin, anhydrous sodium sulfite, Rongalite and the like.
Examples of the dispersant include fatty acids, fatty acid salts, surfactants, organic metals, chelating agents, protective colloids and the like.
（形状加工）
本銀粉は、そのまま利用することも可能であるが、本銀粉を形状加工処理した上で、利用することもできる。
例えば、球状粒子粉末（：８０％以上が球状粒子からなる粉末）を、機械的に形状加工して、フレーク状、鱗片状、平板状などの非球状粒子粉末（：８０％以上が非球状粒子からなる粉末）に加工することができる。
より具体的には、ビーズミル、ボールミル、アトライター、振動ミルなどを用いて機械的に偏平化加工（圧伸延または展伸）することにより、フレーク状粒子粉末（：８０％以上がフレーク状粒子からなる粉末）に形状加工することができる。この際、粒子同士の凝集や結合を防止しながら各粒子を独立した状態で加工するために、例えばステアリン酸などの脂肪酸や、界面活性剤などの助剤を添加するのが好ましい。
そして、このような形状加工処理した銀粉を利用することもできるし、また、形状加工しない元粉とこれとを混合して利用することもできる。 (Shape processing)
Although the present silver powder can be used as it is, it can also be used after the present silver powder has been processed into a shape.
For example, a spherical particle powder (powder consisting of 80% or more of spherical particles) is mechanically processed into non-spherical particle powders such as flakes, scales, and flat plates (: 80% or more of non-spherical particles) Powder).
More specifically, flaky particle powder (: 80% or more from flaky particles) is mechanically flattened (rolled or stretched) using a bead mill, ball mill, attritor, vibration mill or the like. Shape powder). At this time, in order to process each particle independently while preventing aggregation and bonding of the particles, it is preferable to add a fatty acid such as stearic acid or an auxiliary agent such as a surfactant.
And the silver powder which carried out such shape processing can also be utilized, and the original powder which is not shape-processed and this can also be mixed and utilized.
本銀粉は、そのまま利用することも可能であるが、本銀粉を形状加工処理した上で、利用することもできる。
例えば、球状粒子粉末（：８０％以上が球状粒子からなる粉末）を、機械的に形状加工して、フレーク状、鱗片状、平板状などの非球状粒子粉末（：８０％以上が非球状粒子からなる粉末）に加工することができる。
より具体的には、ビーズミル、ボールミル、アトライター、振動ミルなどを用いて機械的に偏平化加工（圧伸延または展伸）することにより、フレーク状粒子粉末（：８０％以上がフレーク状粒子からなる粉末）に形状加工することができる。この際、粒子同士の凝集や結合を防止しながら各粒子を独立した状態で加工するために、例えばステアリン酸などの脂肪酸や、界面活性剤などの助剤を添加するのが好ましい。
そして、このような形状加工処理した銀粉を利用することもできるし、また、形状加工しない元粉とこれとを混合して利用することもできる。 (Shape processing)
Although the present silver powder can be used as it is, it can also be used after the present silver powder has been processed into a shape.
For example, a spherical particle powder (powder consisting of 80% or more of spherical particles) is mechanically processed into non-spherical particle powders such as flakes, scales, and flat plates (: 80% or more of non-spherical particles) Powder).
More specifically, flaky particle powder (: 80% or more from flaky particles) is mechanically flattened (rolled or stretched) using a bead mill, ball mill, attritor, vibration mill or the like. Shape powder). At this time, in order to process each particle independently while preventing aggregation and bonding of the particles, it is preferable to add a fatty acid such as stearic acid or an auxiliary agent such as a surfactant.
And the silver powder which carried out such shape processing can also be utilized, and the original powder which is not shape-processed and this can also be mixed and utilized.
本銀粉は、粒径がきれいに揃っているため、粒径に適したメディアを効果的に選択できるため、フレーク粉としても、均質なフレーク粉粒子を得ることができる。
球形粉とフレーク粉の混合粉でもよい。 Since the present silver powder has a uniform particle size, a medium suitable for the particle size can be effectively selected, so that even flake powder can obtain uniform flake powder particles.
A mixed powder of spherical powder and flake powder may be used.
球形粉とフレーク粉の混合粉でもよい。 Since the present silver powder has a uniform particle size, a medium suitable for the particle size can be effectively selected, so that even flake powder can obtain uniform flake powder particles.
A mixed powder of spherical powder and flake powder may be used.
＜用途＞
本銀粉は、導電ペースト用、特に焼結型導電性ペースト用の銀粉として好適である。 <Application>
The silver powder is suitable as a silver powder for a conductive paste, particularly for a sintered conductive paste.
本銀粉は、導電ペースト用、特に焼結型導電性ペースト用の銀粉として好適である。 <Application>
The silver powder is suitable as a silver powder for a conductive paste, particularly for a sintered conductive paste.
焼結型導電性ペーストは、例えば有機ビヒクル中に、本銀粉をガラスフリットと共に混合することで調製することができる。
この際、ガラスフリットとしては、例えば、鉛ボロシリケートガラスや、ジンクボロシリケート等の無鉛ガラスも挙げることができる。
また、樹脂バインダーとしては、例えば任意の樹脂バインダーを使用することができる。例えばエポキシ樹脂、ポリエステル樹脂、ケイ素樹脂、ユリア樹脂、アクリル樹脂、セルロース樹脂から選ばれる１種以上を含む組成を採用するのが望ましい。 The sintered conductive paste can be prepared, for example, by mixing the present silver powder together with glass frit in an organic vehicle.
In this case, examples of the glass frit include lead-free glass such as lead borosilicate glass and zinc borosilicate.
Moreover, as a resin binder, arbitrary resin binders can be used, for example. For example, it is desirable to employ a composition containing at least one selected from an epoxy resin, a polyester resin, a silicon resin, a urea resin, an acrylic resin, and a cellulose resin.
この際、ガラスフリットとしては、例えば、鉛ボロシリケートガラスや、ジンクボロシリケート等の無鉛ガラスも挙げることができる。
また、樹脂バインダーとしては、例えば任意の樹脂バインダーを使用することができる。例えばエポキシ樹脂、ポリエステル樹脂、ケイ素樹脂、ユリア樹脂、アクリル樹脂、セルロース樹脂から選ばれる１種以上を含む組成を採用するのが望ましい。 The sintered conductive paste can be prepared, for example, by mixing the present silver powder together with glass frit in an organic vehicle.
In this case, examples of the glass frit include lead-free glass such as lead borosilicate glass and zinc borosilicate.
Moreover, as a resin binder, arbitrary resin binders can be used, for example. For example, it is desirable to employ a composition containing at least one selected from an epoxy resin, a polyester resin, a silicon resin, a urea resin, an acrylic resin, and a cellulose resin.
＜語句の説明＞
本明細書において「Ｘ～Ｙ」（Ｘ，Ｙは任意の数字）と表現する場合、特にことわらない限り「Ｘ以上Ｙ以下」の意と共に、「好ましくはＸより大きい」或いは「好ましくはＹより小さい」の意も包含する。
また、「Ｘ以上」（Ｘは任意の数字）或いは「Ｙ以下」（Ｙは任意の数字）と表現した場合、「Ｘより大きいことが好ましい」或いは「Ｙ未満であることが好ましい」旨の意図も包含する。 <Explanation of words>
In the present specification, when expressed as “X to Y” (X and Y are arbitrary numbers), “X is preferably greater than X” or “preferably Y”, with the meaning of “X to Y” unless otherwise specified. It also includes the meaning of “smaller”.
In addition, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), it is “preferably greater than X” or “preferably less than Y”. Includes intentions.
本明細書において「Ｘ～Ｙ」（Ｘ，Ｙは任意の数字）と表現する場合、特にことわらない限り「Ｘ以上Ｙ以下」の意と共に、「好ましくはＸより大きい」或いは「好ましくはＹより小さい」の意も包含する。
また、「Ｘ以上」（Ｘは任意の数字）或いは「Ｙ以下」（Ｙは任意の数字）と表現した場合、「Ｘより大きいことが好ましい」或いは「Ｙ未満であることが好ましい」旨の意図も包含する。 <Explanation of words>
In the present specification, when expressed as “X to Y” (X and Y are arbitrary numbers), “X is preferably greater than X” or “preferably Y”, with the meaning of “X to Y” unless otherwise specified. It also includes the meaning of “smaller”.
In addition, when expressed as “X or more” (X is an arbitrary number) or “Y or less” (Y is an arbitrary number), it is “preferably greater than X” or “preferably less than Y”. Includes intentions.
以下、本発明を下記実施例及び比較例に基づいてさらに詳述する。
実施例および比較例で得られた銀粉に関して、以下に示す方法で諸特性を評価した。 Hereinafter, the present invention will be further described in detail based on the following examples and comparative examples.
With respect to the silver powder obtained in Examples and Comparative Examples, various characteristics were evaluated by the following methods.
実施例および比較例で得られた銀粉に関して、以下に示す方法で諸特性を評価した。 Hereinafter, the present invention will be further described in detail based on the following examples and comparative examples.
With respect to the silver powder obtained in Examples and Comparative Examples, various characteristics were evaluated by the following methods.
（１）ＳＥＭＤ１０、ＳＥＭＤ５０、ＳＥＭＤ９０
走査型電子顕微鏡（ＳＥＭ）（ＰＨＩＬＩＰＳ社製 ＸＬ３０）を用いて１０００～３０００倍にて撮影した任意の３視野の走査型電子顕微鏡（ＳＥＭ）像を、ＢＭＰファイルに変換し、旭エンジニアリング株式会社製のＩＰ－１０００ＰＣの統合アプリケーションであるＡ像くんで取り込み、円度しきい値５０、重なり度３０、標本数１５０～３５０として円形粒子解析を行ない、ＳＥＭＤ１０、ＳＥＭＤ５０、ＳＥＭＤ９０を手動補正をかけることなく計測した。 (1) SEM D10, SEM D50, SEM D90
A scanning electron microscope (SEM) image of any three fields of view taken at 1000 to 3000 times using a scanning electron microscope (SEM) (XL30 manufactured by PHILIPS) is converted into a BMP file and manufactured by Asahi Engineering Co., Ltd. A-image PC, which is an integrated application of IP-1000PC, performs circular particle analysis with circularity threshold 50, overlap 30 and sample number 150-350, and SEM D10, SEM D50, SEM D90 are manually corrected Measured without applying.
走査型電子顕微鏡（ＳＥＭ）（ＰＨＩＬＩＰＳ社製 ＸＬ３０）を用いて１０００～３０００倍にて撮影した任意の３視野の走査型電子顕微鏡（ＳＥＭ）像を、ＢＭＰファイルに変換し、旭エンジニアリング株式会社製のＩＰ－１０００ＰＣの統合アプリケーションであるＡ像くんで取り込み、円度しきい値５０、重なり度３０、標本数１５０～３５０として円形粒子解析を行ない、ＳＥＭＤ１０、ＳＥＭＤ５０、ＳＥＭＤ９０を手動補正をかけることなく計測した。 (1) SEM D10, SEM D50, SEM D90
A scanning electron microscope (SEM) image of any three fields of view taken at 1000 to 3000 times using a scanning electron microscope (SEM) (XL30 manufactured by PHILIPS) is converted into a BMP file and manufactured by Asahi Engineering Co., Ltd. A-image PC, which is an integrated application of IP-1000PC, performs circular particle analysis with circularity threshold 50, overlap 30 and sample number 150-350, and SEM D10, SEM D50, SEM D90 are manually corrected Measured without applying.
（２）溶存酸素
ＨＯＲＩＢＡ製作所製のＤＯ（溶存酸素）計（ＯＭ－５１）を用いて、ヒドラジン水溶液中の溶存酸素濃度を測定した。 (2) Dissolved oxygen The dissolved oxygen concentration in the hydrazine aqueous solution was measured using a DO (dissolved oxygen) meter (OM-51) manufactured by HORIBA.
ＨＯＲＩＢＡ製作所製のＤＯ（溶存酸素）計（ＯＭ－５１）を用いて、ヒドラジン水溶液中の溶存酸素濃度を測定した。 (2) Dissolved oxygen The dissolved oxygen concentration in the hydrazine aqueous solution was measured using a DO (dissolved oxygen) meter (OM-51) manufactured by HORIBA.
（３）均質性評価
銀粉３．５ｇに、エチルセルロース（１００ｃｐ）を５％含有したテルピネオールを少量ずつ加えながらヘラで混合していき、樹脂が一様になじんだ時点での樹脂添加量（Ｘｇ）を測定した。ペースト中の銀濃度を次の式で求め、９５％以上を均質性が高いと判断した。 (3) Homogeneity evaluation Addition of terpineol containing 5% ethyl cellulose (100 cp) to 3.5 g of silver powder with a spatula while adding little by little, the resin addition amount (Xg) when the resin is evenly blended Was measured. The silver concentration in the paste was determined by the following formula, and 95% or more was judged to have high homogeneity.
銀粉３．５ｇに、エチルセルロース（１００ｃｐ）を５％含有したテルピネオールを少量ずつ加えながらヘラで混合していき、樹脂が一様になじんだ時点での樹脂添加量（Ｘｇ）を測定した。ペースト中の銀濃度を次の式で求め、９５％以上を均質性が高いと判断した。 (3) Homogeneity evaluation Addition of terpineol containing 5% ethyl cellulose (100 cp) to 3.5 g of silver powder with a spatula while adding little by little, the resin addition amount (Xg) when the resin is evenly blended Was measured. The silver concentration in the paste was determined by the following formula, and 95% or more was judged to have high homogeneity.
（ペースト中の銀濃度（％））＝｛（銀粉３．５ｇ）／（銀粉３．５ｇ＋樹脂添加量Ｘｇ）｝×１００
(Silver concentration in paste (%)) = {(silver powder 3.5 g) / (silver powder 3.5 g + resin addition amount Xg)} × 100
＜実施例１＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液６ｍＬを添加して攪拌し、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 1>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 6 mL of a 1% concentration amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 6.00 to 8.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液６ｍＬを添加して攪拌し、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 1>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 6 mL of a 1% concentration amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 6.00 to 8.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
＜実施例２＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液１０ｍＬを添加して攪拌し、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 2>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to a silver ammine complex aqueous solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 6.00 to 8.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液１０ｍＬを添加して攪拌し、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 2>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to a silver ammine complex aqueous solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 6.00 to 8.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
＜実施例３＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度２．９ｇ／Ｌの脂肪酸塩水溶液３５ｍＬ（銀１ｍｏｌに対して１．７６×１０-３ｍｏｌに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 3>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, in a silver ammine complex aqueous solution at 20 ° C., 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L adjusted to a dissolved oxygen concentration of 6.00 to 8.00 mg / L and 35 mL of a fatty acid salt aqueous solution having a concentration of 2.9 g / L ( A mixed solution of 1.76 × 10 −3 mol corresponding to 1 mol of silver) was added and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度２．９ｇ／Ｌの脂肪酸塩水溶液３５ｍＬ（銀１ｍｏｌに対して１．７６×１０-３ｍｏｌに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 3>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, in a silver ammine complex aqueous solution at 20 ° C., 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L adjusted to a dissolved oxygen concentration of 6.00 to 8.00 mg / L and 35 mL of a fatty acid salt aqueous solution having a concentration of 2.9 g / L ( A mixed solution of 1.76 × 10 −3 mol corresponding to 1 mol of silver) was added and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
＜実施例４＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水５０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度５ｇ／Ｌのゼラチン水溶液４８ｍＬ（銀１ｍｏｌに対して１．２９ｇに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 4>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water to prepare a silver nitrate aqueous solution, adding 50 mL of ammonia water having a concentration of 25% by mass and stirring. Next, 1 L of a 11.9 g / L hydrazine aqueous solution adjusted to a dissolved oxygen concentration of 6.00 to 8.00 mg / L and 48 mL of a 5 g / L gelatin aqueous solution adjusted to a silver ammine complex aqueous solution at 20 ° C. (to 1 mol of silver). (Corresponding to 1.29 g), and the mixture was reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水５０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度６．００～８．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度５ｇ／Ｌのゼラチン水溶液４８ｍＬ（銀１ｍｏｌに対して１．２９ｇに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。得られた銀粉粒子は略真球状であった。 <Example 4>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water to prepare a silver nitrate aqueous solution, adding 50 mL of ammonia water having a concentration of 25% by mass and stirring. Next, 1 L of a 11.9 g / L hydrazine aqueous solution adjusted to a dissolved oxygen concentration of 6.00 to 8.00 mg / L and 48 mL of a 5 g / L gelatin aqueous solution adjusted to a silver ammine complex aqueous solution at 20 ° C. (to 1 mol of silver). (Corresponding to 1.29 g), and the mixture was reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample). The obtained silver powder particles were substantially spherical.
＜比較例１＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液６ｍＬを添加して攪拌し、溶存酸素濃度３．００～５．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 1>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 6 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 3.00 to 5.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液６ｍＬを添加して攪拌し、溶存酸素濃度３．００～５．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 1>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 6 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 3.00 to 5.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
＜比較例２＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液６ｍＬを添加して攪拌し、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative example 2>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 6 mL of a 1% concentration amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 0.20 to 2.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液６ｍＬを添加して攪拌し、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative example 2>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 6 mL of a 1% concentration amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 0.20 to 2.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
＜比較例３＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液１０ｍＬを添加して攪拌し、溶存酸素濃度３．００～５．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 3>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 3.00 to 5.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液１０ｍＬを添加して攪拌し、溶存酸素濃度３．００～５．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 3>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 3.00 to 5.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
＜比較例４＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液１０ｍＬを添加して攪拌し、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 4>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 0.20 to 2.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０～３０℃の銀アンミン錯体水溶液に、１％濃度のアミン系の分散剤（平均分子量１００００）水溶液１０ｍＬを添加して攪拌し、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌを混合し、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 4>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, 10 mL of a 1% strength amine-based dispersant (average molecular weight 10,000) aqueous solution is added to an aqueous silver ammine complex solution at 20 to 30 ° C. and stirred to adjust the dissolved oxygen concentration to 0.20 to 2.00 mg / L. 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L was mixed and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
＜比較例５＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度２．９ｇ／Ｌの脂肪酸塩水溶液３５ｍＬ（銀１ｍｏｌに対して１．７６×１０-３ｍｏｌに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 5>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, in a silver ammine complex aqueous solution at 20 ° C., 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L adjusted to a dissolved oxygen concentration of 0.20 to 2.00 mg / L and 35 mL of a fatty acid salt aqueous solution having a concentration of 2.9 g / L ( A mixed solution of 1.76 × 10 −3 mol corresponding to 1 mol of silver) was added and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水６０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。
次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度２．９ｇ／Ｌの脂肪酸塩水溶液３５ｍＬ（銀１ｍｏｌに対して１．７６×１０-３ｍｏｌに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 5>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water, adding 60 mL of ammonia water having a concentration of 25% by mass, and stirring.
Next, in a silver ammine complex aqueous solution at 20 ° C., 1 L of a hydrazine aqueous solution having a concentration of 11.9 g / L adjusted to a dissolved oxygen concentration of 0.20 to 2.00 mg / L and 35 mL of a fatty acid salt aqueous solution having a concentration of 2.9 g / L ( A mixed solution of 1.76 × 10 −3 mol corresponding to 1 mol of silver) was added and reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
＜比較例６＞
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水５０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度５ｇ／Ｌのゼラチン水溶液４８ｍＬ（銀１ｍｏｌに対して１．２９ｇに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 6>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water to prepare a silver nitrate aqueous solution, adding 50 mL of ammonia water having a concentration of 25% by mass and stirring. Next, in a silver ammine complex aqueous solution at 20 ° C., 1 L of a 11.9 g / L hydrazine aqueous solution adjusted to a dissolved oxygen concentration of 0.20 to 2.00 mg / L and 48 mL of a gelatin aqueous solution of 5 g / L concentration (into 1 mol of silver). (Corresponding to 1.29 g), and the mixture was reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
銀濃度４００ｇ／Ｌの硝酸銀水溶液５０ｍＬを純水１Ｌに溶解させて硝酸銀水溶液を調製し、濃度２５質量％のアンモニア水５０ｍＬを添加して攪拌することにより、銀アンミン錯体水溶液を得た。次いで、２０℃の銀アンミン錯体水溶液に、溶存酸素濃度０．２０～２．００ｍｇ／Ｌに調整した、濃度１１．９ｇ／Ｌのヒドラジン水溶液１Ｌと濃度５ｇ／Ｌのゼラチン水溶液４８ｍＬ（銀１ｍｏｌに対して１．２９ｇに相当）の混合溶液を加えて、撹拌することなく反応させて銀粒子を還元析出させた。
次いで、この銀粒子をろ過し、ろ液の伝導率が４０μＳ／ｃｍ以下となるまで水洗後、乾燥させることにより銀粉（サンプル）を得た。 <Comparative Example 6>
A silver nitrate aqueous solution was obtained by dissolving 50 mL of a silver nitrate aqueous solution having a silver concentration of 400 g / L in 1 L of pure water to prepare a silver nitrate aqueous solution, adding 50 mL of ammonia water having a concentration of 25% by mass and stirring. Next, in a silver ammine complex aqueous solution at 20 ° C., 1 L of a 11.9 g / L hydrazine aqueous solution adjusted to a dissolved oxygen concentration of 0.20 to 2.00 mg / L and 48 mL of a gelatin aqueous solution of 5 g / L concentration (into 1 mol of silver). (Corresponding to 1.29 g), and the mixture was reacted without stirring to reduce and precipitate silver particles.
Then, the silver particles were filtered, washed with water until the filtrate had a conductivity of 40 μS / cm or less, and dried to obtain silver powder (sample).
（考察）
実施例の銀粉は、比較例の銀粉及び従来知られた銀粉に比べて大粒子でありながら、粒径が揃っているため、これを用いて銀ペーストを作製すれば、銀濃度を高くすることができ、均質で且つ、電気抵抗がより一層低い焼結導体を形成することができる。
このような観点から、本銀粉においては、ＳＥＭＤ５０が２．５０μｍ～７．５０μｍであり、且つ、（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０であるのが好ましいと考えることができる。 (Discussion)
Although the silver powder of the examples is larger than the silver powder of the comparative example and the conventionally known silver powder, the particle size is uniform, so if a silver paste is produced using this, the silver concentration is increased. It is possible to form a sintered conductor that is homogeneous and has a lower electrical resistance.
From this point of view, in this silver powder, SEM D50 is 2.50μm ~ 7.50μm, and can be considered as preferably a (SEM D90- SEM D10) / SEM D50 ≦ 0.50 .
実施例の銀粉は、比較例の銀粉及び従来知られた銀粉に比べて大粒子でありながら、粒径が揃っているため、これを用いて銀ペーストを作製すれば、銀濃度を高くすることができ、均質で且つ、電気抵抗がより一層低い焼結導体を形成することができる。
このような観点から、本銀粉においては、ＳＥＭＤ５０が２．５０μｍ～７．５０μｍであり、且つ、（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０であるのが好ましいと考えることができる。 (Discussion)
Although the silver powder of the examples is larger than the silver powder of the comparative example and the conventionally known silver powder, the particle size is uniform, so if a silver paste is produced using this, the silver concentration is increased. It is possible to form a sintered conductor that is homogeneous and has a lower electrical resistance.
From this point of view, in this silver powder, SEM D50 is 2.50μm ~ 7.50μm, and can be considered as preferably a (SEM D90- SEM D10) / SEM D50 ≦ 0.50 .
Claims (4)
- 走査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ５０（「ＳＥＭＤ５０」と称する）が２．５０μｍ～７．５０μｍであり、
走査型電子顕微鏡像（ＳＥＭ）の画像解析により得られるＤ１０（「ＳＥＭＤ１０」と称する）、Ｄ５０（「ＳＥＭＤ５０」と称する）及びＤ９０（「ＳＥＭＤ９０」と称する）の関係が、関係式：（ＳＥＭＤ９０―ＳＥＭＤ１０）／ＳＥＭＤ５０≦０．５０で示されることを特徴とする銀粉。 D50 (referred to as “ SEM D50”) obtained by image analysis of a scanning electron microscope image (SEM) is 2.50 μm to 7.50 μm,
The relationship between D10 (referred to as “ SEM D10”), D50 (referred to as “ SEM D50”) and D90 (referred to as “ SEM D90”) obtained by image analysis of a scanning electron microscope image (SEM) is a relational expression: Silver powder characterized by being represented by ( SEM D90- SEM D10) / SEM D50 ≦ 0.50. - 湿式銀粉であることを特徴とする請求項１記載の銀粉。 The silver powder according to claim 1, which is a wet silver powder.
- 請求項１又は２に記載の銀粉を形状加工処理してなる銀粉。 A silver powder obtained by subjecting the silver powder according to claim 1 or 2 to shape processing. *
- 請求項１～３の何れかに記載の銀粉を用いてなる焼結型導電性ペースト。
A sintered conductive paste using the silver powder according to any one of claims 1 to 3.
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| WO2013136615A1 true WO2013136615A1 (en) | 2013-09-19 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2012/082330 WO2013136615A1 (en) | 2012-03-12 | 2012-12-13 | Silver powder |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JP5985216B2 (en) |
| KR (1) | KR20140089365A (en) |
| CN (1) | CN103930226B (en) |
| TW (1) | TW201338893A (en) |
| WO (1) | WO2013136615A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6282616B2 (en) * | 2014-07-30 | 2018-02-21 | Ｄｏｗａエレクトロニクス株式会社 | Silver powder and method for producing the same |
| KR101930285B1 (en) * | 2016-10-31 | 2018-12-19 | 엘에스니꼬동제련 주식회사 | Electrode Paste For Solar Cell's Electrode And Solar Cell using the same |
| CN110586959A (en) * | 2019-10-28 | 2019-12-20 | 苏州银瑞光电材料科技有限公司 | Preparation method of flake silver powder with high tap density |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004307881A (en) * | 2003-04-02 | 2004-11-04 | Dowa Mining Co Ltd | Copper powder and manufacturing method therefor |
| JP2008179851A (en) * | 2007-01-24 | 2008-08-07 | Mitsui Mining & Smelting Co Ltd | Method for manufacturing silver powder, and silver powder |
| JP2009221591A (en) * | 2007-08-31 | 2009-10-01 | Dowa Electronics Materials Co Ltd | Method for producing silver powder |
| JP2010070793A (en) * | 2008-09-17 | 2010-04-02 | Dowa Electronics Materials Co Ltd | Spherical silver powder and method for producing the same |
| JP2011042839A (en) * | 2009-08-21 | 2011-03-03 | Dowa Electronics Materials Co Ltd | Method for producing silver powder and production device therefor |
| JP2011052300A (en) * | 2009-09-04 | 2011-03-17 | Dowa Electronics Materials Co Ltd | Flaky silver powder, method for producing the same, and conductive paste |
| JP2011208278A (en) * | 2010-03-10 | 2011-10-20 | Dowa Holdings Co Ltd | Flaky silver powder and method for producing the same |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007270312A (en) * | 2006-03-31 | 2007-10-18 | Mitsui Mining & Smelting Co Ltd | Method for manufacturing silver powder, and silver powder |
| CN102157220B (en) * | 2011-02-28 | 2013-09-18 | 张振中 | Special Ag paste for grid line electrode at front surface of crystalline silicon solar battery |
-
2012
- 2012-03-12 JP JP2012054119A patent/JP5985216B2/en active Active
- 2012-12-13 KR KR1020147011996A patent/KR20140089365A/en not_active Application Discontinuation
- 2012-12-13 CN CN201280056091.XA patent/CN103930226B/en active Active
- 2012-12-13 WO PCT/JP2012/082330 patent/WO2013136615A1/en active Application Filing
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2013
- 2013-01-22 TW TW102102302A patent/TW201338893A/en unknown
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004307881A (en) * | 2003-04-02 | 2004-11-04 | Dowa Mining Co Ltd | Copper powder and manufacturing method therefor |
| JP2008179851A (en) * | 2007-01-24 | 2008-08-07 | Mitsui Mining & Smelting Co Ltd | Method for manufacturing silver powder, and silver powder |
| JP2009221591A (en) * | 2007-08-31 | 2009-10-01 | Dowa Electronics Materials Co Ltd | Method for producing silver powder |
| JP2010070793A (en) * | 2008-09-17 | 2010-04-02 | Dowa Electronics Materials Co Ltd | Spherical silver powder and method for producing the same |
| JP2011042839A (en) * | 2009-08-21 | 2011-03-03 | Dowa Electronics Materials Co Ltd | Method for producing silver powder and production device therefor |
| JP2011052300A (en) * | 2009-09-04 | 2011-03-17 | Dowa Electronics Materials Co Ltd | Flaky silver powder, method for producing the same, and conductive paste |
| JP2011208278A (en) * | 2010-03-10 | 2011-10-20 | Dowa Holdings Co Ltd | Flaky silver powder and method for producing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103930226B (en) | 2016-03-02 |
| TW201338893A (en) | 2013-10-01 |
| KR20140089365A (en) | 2014-07-14 |
| JP5985216B2 (en) | 2016-09-06 |
| CN103930226A (en) | 2014-07-16 |
| JP2013185251A (en) | 2013-09-19 |
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