WO2018066723A1 - Method for preparing flake-type silver powder by using agglomerated silver powder - Google Patents

Method for preparing flake-type silver powder by using agglomerated silver powder Download PDF

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Publication number
WO2018066723A1
WO2018066723A1 PCT/KR2016/011091 KR2016011091W WO2018066723A1 WO 2018066723 A1 WO2018066723 A1 WO 2018066723A1 KR 2016011091 W KR2016011091 W KR 2016011091W WO 2018066723 A1 WO2018066723 A1 WO 2018066723A1
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Prior art keywords
silver powder
flake
powder
silver
agglomerated
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PCT/KR2016/011091
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French (fr)
Korean (ko)
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강태훈
이미영
최재원
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엘에스니꼬동제련 주식회사
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Priority to PCT/KR2016/011091 priority Critical patent/WO2018066723A1/en
Publication of WO2018066723A1 publication Critical patent/WO2018066723A1/en

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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
    • 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
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • 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 method for producing a flake silver powder for conductive paste used in electronic parts such as electrode materials.
  • well-dispersed silver powder of uniform size in the metal powder may be utilized as an important material for various electronic industries such as conductive inks, pastes, and adhesives.
  • Flake silver powder used as electrode material is mainly used for low temperature hardening type conductive paste because of the large contact area between particles, especially Membrane Touch Switch (MTS), Printed Circuit Board (PCB), LED light.
  • MTS Membrane Touch Switch
  • PCB Printed Circuit Board
  • LED light LED light.
  • the electrode is formed with a large silver wire content and a low silver powder content, such as sensor electrodes, flake silver powder with a large particle diameter (5 ⁇ m or more), a thin thickness (high aspect ratio, particle diameter / thickness), and a low tap density It is mainly used in favor of this conductivity.
  • the manufacture of flake silver powder consists of a synthesis process of silver powder (called raw powder) used as a raw material and a processing step of processing raw powder into flake shape through mechanical milling using beads.
  • Patent No. 4841987, Oct. 14, 2011 Prior Patent Document 2 (Japanese Patent Laid-Open No. 2012-062531, 2012.03.29.)
  • Prior Patent Document 3 Japanese Patent No. 3341920, 2002.08.23.
  • a micron-sized spherical powder such as ball mill or attrition mill, is manufactured by mixing and milling spherical silver powder having a predetermined particle diameter in a bead mill having a predetermined particle diameter to produce flake silver powder. It is disclosed to produce flake silver powder satisfying the above characteristics by milling for a long time.
  • the prior art has a long manufacturing time in the flake processing process and a low concentration of silver in the slurry, there is a problem that the manufacturing cost is high, and by a long time milling to increase the particle size, the aggregation between the flake particles increases, It is difficult to control the thickness of the powder.
  • the present inventors intend to disclose a method for producing flake powder using agglomerated powder, not spherical powder.
  • the present invention is to solve the above problems by using agglomerated powder rather than spherical powder as the raw material of the flake silver powder, it is possible to manufacture a high concentration (high Ag concentration), low manufacturing cost, easy to control the particle size, thickness It is to provide a method for producing a flake silver powder having a thin aspect ratio and an average particle diameter of 5 ⁇ m or more and having a high aspect ratio.
  • the present invention provides a method for producing flake silver powder, comprising a flaked step (S2) of obtaining a flake powder by milling through beads using agglomerated silver powder as a raw material powder, the agglomerated silver powder has a particle size The silver particle which is 0.5-2.0 micrometers aggregates, and it provides the manufacturing method of the flake silver powder which is a silver powder with an average particle diameter of 5.0-20.0 micrometers, and a specific surface area of 0.1-0.6m ⁇ 2> / g.
  • the flake powder is separated from the beads, washed, dried and pulverized to obtain a flake silver powder (S4); further comprising an average particle diameter (D50) of 5.0 to 15.0 ⁇ m and a tap density.
  • D50 average particle diameter
  • a method for producing flake silver powder which obtains flake silver powder of 2.5 g / cc or less and a thickness of 300 nm or less.
  • the flaked powder is further separated from the beads, washed, dried and pulverized to obtain a flake silver powder, further comprising a post-treatment step (S4), where the flake silver having an aspect ratio (average particle diameter (D50) / thickness) of 15 or more is obtained.
  • Flake obtaining powder provides a powder production method.
  • the flakes step (S2) is a slurry of the aggregated silver powder, flake silver powder manufacturing, characterized in that the step of milling at 300 to 700rpm speed for 3 to 6 hours using beads of 1 to 5mm Provide a method.
  • the flakes step (S2) Previously, a raw powder manufacturing step (S1) of preparing agglomerated silver powder by adding a reducing solution containing a reducing agent to a silver source solution containing silver (Ag); and the silver source solution further comprises the silver It provides a method for producing a flake silver powder, characterized in that the solution containing 0.4 to 0.7 equivalents of ammonia relative to the content of (Ag).
  • the reducing solution includes a single type of reducing agent, or includes two or more kinds of reducing agents having different reduction rates, to provide a method for producing flake silver powder, characterized in that to control the particle size of the aggregated silver powder produced.
  • silver particles having a particle size of 0.5 to 2.0 ⁇ m are aggregated, and the particles are flaked by milling through beads using agglomerated silver powder having an average particle size of 5.0 to 20.0 ⁇ m and a specific surface area of 0.1 to 0.6 m 2 / g. Flakes, which are ground powders, provide a powder.
  • the flake silver powder has a flake silver powder having an average particle diameter (D50) of 5.0 to 15.0 ⁇ m, a tap density of 2.5 g / cc or less, and a thickness of 300 nm or less.
  • D50 average particle diameter
  • the flake silver powder provides a flake silver powder, characterized in that the aspect ratio (average particle diameter (D50) / thickness) is 15 or more.
  • the present invention is a flake silver powder; And it provides a conductive paste comprising a binder resin.
  • the present invention can be produced in a high concentration, can reduce the manufacturing time to reduce the cost, the flakes produced by controlling the particle size of the aggregated powder is a thin thickness and large average particle size [ In other words, it is possible to provide a method for producing flake silver powder having a high aspect ratio (particle size / thickness).
  • agglomerated powders having a primary particle size of 0.5 to 2.0 ⁇ m, an average particle size of 5.0 to 20.0 ⁇ m, and a specific surface area of 0.1 to 0.6 m 2 / g are produced at a low production cost by using a general milling facility and 1 to 5 mm beads. It is possible to provide a method for producing a flake silver powder having an average particle diameter (D50) to 15.0 ⁇ m, a thickness of 300 nm or less, a tap density of 2.5 g / cc or less, and an aspect ratio of 15 or more.
  • D50 average particle diameter
  • Example 1 shows an SEM photograph of the raw material powder according to Example 1 of the present invention.
  • Example 2 shows an SEM photograph of the raw material powder according to Example 2 of the present invention.
  • Example 6 is a SEM photograph of the flake powder according to Example 1 of the present invention.
  • Example 7 is a SEM photograph of the flake powder according to Example 2 of the present invention.
  • Flakes silver powder manufacturing method comprises a raw material powder manufacturing step (S1), flakes step (S2) and after-treatment step (S3).
  • the flake forming step (S2) according to the present invention is necessarily included, and steps other than those which may unnecessarily obscure the subject matter of the invention can be omitted.
  • Raw material powder manufacturing step (S1) is a step for producing agglomerated silver powder, the specific method is as follows.
  • a silver solution is added to the silver source solution to reduce silver (Ag) to precipitate silver particles. That is, after preparing a silver source solution containing silver (Ag), a reducing solution containing a reducing agent is added to reduce the silver to obtain a silver powder. The reducing solution may be slowly added or temporarily added while the silver source solution is stirred.
  • the silver source solution containing silver (Ag) is not limited as long as it is a solution in which silver particles can be precipitated by a reducing agent, and silver nitrate solution, silver oxide solution, silver salt complex or silver intermediate solution can be used. Can be.
  • the pH in the silver source solution can be adjusted using ammonia, and ammonia is used in an amount of 0.4 to 0.7 equivalents based on the content of silver ions. If the content of ammonia is 0.4 equivalent or less, the pH in the silver source solution is low, so the reduction rate by the reducing agent added in the precipitation process of silver particles may be slow, resulting in unreacted reaction that does not terminate.In the case of 0.7 equivalent or more, silver particle precipitation process may occur. There is a problem that the Ag 0 reduced in the fine particles and spheroidization through the rapid nucleation is difficult to obtain the aggregated powder required by the present patent. In addition, it is also good to use a mixture of nitric acid to adjust the pH.
  • the reducing agent may be used alone or in combination of any one or more selected from the group consisting of ascorbic acid, hydrazine, hydroquinone and formalin.
  • the reducing agent may react with all the ions by using 1/3 to 2/3 equivalents of the silver ion content, and when insufficient, unreacted reaction may occur, and residual organic matter may be deposited in the powder when over-added. Preferably 0.5 equivalents to the silver ion content is used.
  • the primary particle size of the agglomerated silver powder produced according to the type of reducing agent can be controlled.
  • the use of a reducing agent with a large reducing agent causes the nucleation rate to be faster than the growth rate during the precipitation of silver particles. Can be obtained. Therefore, the reducing solution may include a single type of reducing agent, or may include two or more kinds of reducing agents having different reduction rates, thereby controlling the particle diameter of the aggregated silver powder.
  • the aggregated silver After completing the step of preparing the raw material powder by washing and drying with pure water, the aggregated silver having a primary particle size of 0.5 to 2.0 ⁇ m, average particle diameter of 5.0 to 20.0 ⁇ m, specific surface area of 0.1 ⁇ 0.6 m 2 / g Get powder.
  • Flaking step (S2) is a step to flake through a mechanical milling (milling) through the beads by slurrying the aggregated silver powder, a specific method is as follows.
  • Agglomerated silver powder may be used agglomerated silver powder prepared through the raw material powder manufacturing step (S1), but is not limited thereto, and primary silver particles having a particle diameter of 0.5 to 2.0 ⁇ m are agglomerated, and the average particle diameter is 5.0 to Aggregated silver powder with a specific surface area of 0.1 to 0.6 m 2 / g is used at 20.0 ⁇ m.
  • Agglomerated silver powders are slurried.
  • the lubricant is added to the solvent, stirred until the lubricant is dissolved, and then the aggregated silver powder is dispersed in the solvent to form a slurry.
  • the flakes obtained are highly dependent on the properties of the powder.
  • a solvent in which the aggregated silver powder is dispersed a mixed solvent of water, an organic solvent, and water and an organic solvent can be used. In consideration of the residual of the solvent component as a contaminant on the particle surface, it is preferable to use a solvent having a composition close to water.
  • an organic solvent alone in consideration of the stabilization of the quality of the aggregated silver powder in the slurry to increase the dispersibility of the powder.
  • the use of alcohols such as methanol, ethanol, ethylene glycol, etc. as the organic solvent is highly volatile, and the flake silver powder may have little residue on the particle surface during drying.
  • the blending amount of the aggregated silver powder in the solvent is appropriately determined.
  • the solvent is used 25 to 50 parts by weight based on 100 parts by weight of the aggregated silver powder
  • the lubricant is used 0.5 to 5 parts by weight based on 100 parts by weight of the aggregated silver powder.
  • the slurry containing the aggregated silver powder is milled using an impact mill using the impact of the ball.
  • the attrition mill is a milling apparatus in which a shaft and zirconia balls are filled in a vertical alumina. Detailed milling process is shown in Table 1 below.
  • Powder loading 500-800 g Ball material Zirconia Ball size 1-5mm Ball input 250 to 500 wt.% Of Ag powder Milling time 3 ⁇ 6hrs Milling speed 300 ⁇ 700rpm slush Fatty acid group menstruum Alcohol group
  • the flake silver powder produced by controlling the particle size of the aggregated powder minimizes the squeeze between the powders, and the method of producing the flake silver powder having a thin thickness and a large average particle diameter (that is, having a high aspect ratio (particle size / thickness)), which can control the particle size. Can be provided.
  • Post-treatment step (S3) is a purification step including a washing, drying, and disintegration process, by using a screen (screen) to separate the ball / slurry, and further adding a solvent and stirring silver
  • the powder is washed, dried and crushed.
  • the prepared flake may be a step of gravity settling the powder, removing a solution containing an organic material such as a lubricant on the upper layer, and then drying the slurry at 80 ° C. for 10 hrs.
  • the washing method is not particularly limited, but a method of recovering the flake silver powder by injecting the flake silver powder solid-liquid separated from the slurry into the washing liquid, stirring using a stirrer or an ultrasonic cleaner, and then solid-liquid separation again can be used. .
  • a method of recovering the flake silver powder by injecting the flake silver powder solid-liquid separated from the slurry into the washing liquid, stirring using a stirrer or an ultrasonic cleaner, and then solid-liquid separation again can be used.
  • cleaning liquid may use water, in order to remove a lubricant and organic substance efficiently, it is preferable to use aqueous alkali solution or ethanol aqueous solution.
  • the flake silver powder prepared through the post-treatment has an average particle diameter (D50) of 5.0 to 15.0 ⁇ m, a thickness of 300 nm or less, a tap density of 2.5 g / cc or less, and an aspect ratio (average particle diameter (D50) / thickness) of 15 or more.
  • D50 average particle diameter
  • the flake silver powder manufactured by the method for manufacturing flake silver powder according to an embodiment of the present invention may be a membrane touch switch (Membrane Touch Switch, MTS), a printed circuit board (PCB), an LED light, a sensor electrode, or the like.
  • MTS Membrane Touch Switch
  • PCB printed circuit board
  • LED light LED light
  • sensor electrode or the like.
  • This large and low silver powder content is most suitable for use in conductive pastes for electronic components forming electrodes.
  • the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion
  • the stirring was stopped, the solid particles were separated from the silver particles and the reaction solution using a centrifuge, washed and dried through pure water to prepare a raw material powder.
  • the SEM photograph of the aggregated silver powder obtained by the above process is shown in FIG. 1, and as shown in Table 2, the primary particle diameter was 8.0 ⁇ m with a D50 of 0.5 to 1.5 ⁇ m PSA, and the specific surface area was 0.45 m 2 / g. .
  • the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion
  • the stirring was stopped, the solid particles were separated from the silver particles and the reaction solution using a centrifuge, washed and dried through pure water to prepare a raw material powder.
  • the SEM photograph of the aggregated silver powder obtained by the above process is shown in FIG. As shown in Table 2, the primary particle diameter was 16.9 ⁇ m and the specific surface area of D50 by 0.8-2.0 ⁇ m PSA was 0.25 m 2 / g.
  • Example 2 Flake and post-treatment in the same manner as in Example 1 using the prepared aggregated silver powder, the SEM photograph of the obtained flake silver powder is shown in FIG. As shown in Table 3, D10 4.9 micrometers, D50 11.4 micrometers, D90 19.4 micrometers by PSA, 2.2 g / cc of tap density, 0.181 micrometer of thickness, and 62.98 of aspect ratios were 62.98.
  • the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion
  • the SEM photograph of the spherical silver powder obtained by the above process was shown in FIG. 3, The characteristic was D50 of 1.13 micrometer and specific surface area of 0.9 m ⁇ 2> / g as shown in Table 2.
  • Flake silver powder was obtained by flake formation in the same manner as in Example 1 using the spherical silver powder, the SEM photograph of the obtained flake silver powder is shown in FIG. As shown in Table 3, D10 1.3 ⁇ m, D50 4.5 ⁇ m, D90 11.2 ⁇ m, tap density 3.3g / cc, powder thickness 0.42 ⁇ m and aspect ratio 10.71 by PSA.
  • the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion
  • the SEM photograph of the spherical silver powder obtained by the above process is shown in FIG. 4, and the characteristic was D50 of 2.13 micrometers and specific surface area of 0.3 m ⁇ 2> / g as shown in Table 2.
  • Flake silver powder was obtained by flake forming in the same manner as Example 1 to Example 2 using the spherical silver powder, and the SEM photograph of the obtained flake silver powder is shown in FIG. 9.
  • Table 3 D10 by 2.7 micrometers, D50 6.2 micrometers, D90 13.1 micrometers, tap density was 3.0 g / cc, thickness was 0.45 micrometer, and aspect ratio was 13.77.
  • 900 g of silver nitrate solution was dissolved in 900 ml of pure water to prepare a silver nitrate aqueous solution, and 370 g of 45% NaOH solution at 45% was added thereto and stirred to obtain a silver oxide solution of pH 10.
  • the silver oxide solution was added with 350 g of a 15% reduction solution at a rate of 80 ml / min, followed by stirring to reduce the aggregated silver powder.
  • the reducing agent used at this time was glucose, and the reaction temperature was maintained at 25 ° C.
  • the agglomerated silver powder solution obtained as described above was filtered using Nutsche, washed with 5 L of pure water, and dried at 80 ° C. for 10 hours to obtain agglomerated silver powder.
  • the SEM photograph of the aggregated silver powder obtained by the above process is shown in FIG. 5, and the characteristics thereof are as shown in Table 2, and the primary particle diameter is 0.2 to 0.5 ⁇ m, D50 is 4.8 ⁇ m, and the specific surface area is 1.5 m 2. / g.
  • Flake silver powder was obtained by flake formation in the same manner as in Example 1 using the aggregated silver powder, and the SEM photograph of the obtained flake silver powder is shown in FIG. 10. As shown in Table 3, D10 1.4 micrometers, D50 4.7 micrometers, D90 13.3 micrometers by PSA, 3.5 g / cc of tap density, 0.38 micrometer of powder thickness, and 12.37 of aspect ratio.
  • the flakes prepared in Table 3 show the particle size analysis (D10, D50, D90), thickness and tap density, aspect ratio, and specific surface area measurement data of the powder, prepared by Examples and Comparative Examples in FIGS.
  • the flakes showed FE-SEM photographs of the powder.
  • the particle size of the flake silver powder can be controlled according to the size of the aggregated silver powder, and the thickness of the prepared flake silver powder can be compared with the comparative examples. It can be seen that the aspect ratio of the particle size / thickness is high (15 or more) because of its thinness, low tap density, and large average particle size.
  • the thickness of the flakes due to the mutual compression between the powders is thick and shows a high tap density and a low average particle diameter.
  • the particle size of the flake silver powder is too large, the binding characteristics by the vehicle is not good, As a result, there is a problem that the dispersibility of the paste is lowered and the printability is lowered and the electrical conductivity is reduced.

Abstract

The present invention relates to a method for preparing a flake-type silver powder, comprising a flaking step (S2) of using an agglomerated silver powder as a material powder so as to obtain a powder flaked by means of milling through beads, wherein the agglomerated silver powder is obtained by agglomerating silver particles having a diameter of 0.5-2.0 μm and has an average diameter of 5.0-20.0 μm and a specific surface area of 0.1-0.6 m2/g. The present invention can provide a method for preparing a flake-type silver powder having a small thickness and a large average diameter, that is, having a high aspect ratio (diameter/thickness), the method enabling: preparation with low preparation costs by using universal milling facilities and beads since an agglomerated powder instead of a spherical powder is used as a material powder; and particle size to be controlled while minimizing the compression between flake-type silver powders to be prepared since the particle size of the agglomerated powder is controlled.

Description

응집형 은 분말을 이용한 플레이크형 은 분말의 제조방법Method for producing flake type silver powder using agglomerated silver powder
본 발명은 전극재료 등 전자부품에 사용되는 도전성 페이스트용 플레이크 은 분말의 제조방법에 관한 것이다.The present invention relates to a method for producing a flake silver powder for conductive paste used in electronic parts such as electrode materials.
일반적으로 금속 분말 중에서 균일한 크기의 잘 분산된 은(Silver) 분말은 전도성 잉크나 페이스트(Pastes) 그리고 접착제(Adhesives) 등의 여러 가지 전자 산업에 중요한 재료로서 활용될 수 있다.In general, well-dispersed silver powder of uniform size in the metal powder may be utilized as an important material for various electronic industries such as conductive inks, pastes, and adhesives.
전극재료로 사용되는 플레이크 은 분말은 입자간의 접촉면적이 넓기 때문에 주로 저온 경화형 전도성 페이스트에 사용되며, 특히 멤브레인 터치 스위치(Membrane Touch Switch, MTS)나 인쇄회로기판(Printed Circuit Board, PCB), LED 라이트, 센서 전극과 같이 전극의 선폭이 크고 낮은 은 분말 함량으로 전극을 형성하는 응용분야에는 입경이 크고(5μm 이상), 두께가 얇으며(높은 종횡비, 입경/두께), 탭밀도가 낮은 플레이크 은 분말이 전도성에 유리하여 주로 사용된다. Flake silver powder used as electrode material is mainly used for low temperature hardening type conductive paste because of the large contact area between particles, especially Membrane Touch Switch (MTS), Printed Circuit Board (PCB), LED light. For applications in which the electrode is formed with a large silver wire content and a low silver powder content, such as sensor electrodes, flake silver powder with a large particle diameter (5 μm or more), a thin thickness (high aspect ratio, particle diameter / thickness), and a low tap density It is mainly used in favor of this conductivity.
플레이크 은 분말의 제조는 원료로 사용되는 은 분말(원료분말이라 칭함)의 합성 공정과 비즈를 이용하여 기계적 밀링을 통해 원료분말을 플레이크 형상으로 가공하는 가공 공정으로 이루어 지는데, 선행 특허문헌 1(일본등록특허 제4841987호, 2011.10.14.), 선행 특허문헌 2(일본공개특허 제2012-062531호, 2012.03.29.) 및 선행 특허문헌 3(일본등록특허 제3341920호, 2002.08.23.)에 소정의 입경을 갖는 구상 은 분말을 소정 입경의 비즈를 갖는 비즈밀 내에서 혼합 밀링하여 도전성 페이스트용으로 사용되는 플레이크 은 분말을 제조하는 등 마이크론 크기의 구형 분말을 볼밀이나 어트리션밀과 같은 기계적 밀링에 의해 장시간 밀링하여 상기 특성을 만족하는 플레이크 은 분말을 제조하는 것을 개시하고 있다. The manufacture of flake silver powder consists of a synthesis process of silver powder (called raw powder) used as a raw material and a processing step of processing raw powder into flake shape through mechanical milling using beads. Patent No. 4841987, Oct. 14, 2011), Prior Patent Document 2 (Japanese Patent Laid-Open No. 2012-062531, 2012.03.29.) And Prior Patent Document 3 (Japanese Patent No. 3341920, 2002.08.23.) A micron-sized spherical powder, such as ball mill or attrition mill, is manufactured by mixing and milling spherical silver powder having a predetermined particle diameter in a bead mill having a predetermined particle diameter to produce flake silver powder. It is disclosed to produce flake silver powder satisfying the above characteristics by milling for a long time.
그러나 종래 기술은 플레이크화 가공공정에서 제조 시간이 길고 슬러리 내의 은 농도가 낮으며, 이로 인해 제조 비용이 높은 문제점이 있고, 입경을 증대시키기 위해 장시간 밀링을 함으로써 플레이크 입자 간의 응집이 증가하고, 이로 인해 분말의 두께 제어가 어려운 문제점이 있다. However, the prior art has a long manufacturing time in the flake processing process and a low concentration of silver in the slurry, there is a problem that the manufacturing cost is high, and by a long time milling to increase the particle size, the aggregation between the flake particles increases, It is difficult to control the thickness of the powder.
상기와 같은 문제점을 해결하기 위하여 본 특허 발명자들은 구형 분말이 아닌 응집형 분말을 사용하여 플레이크 분말을 제조하는 방법을 개시하고자 한다. In order to solve the above problems, the present inventors intend to disclose a method for producing flake powder using agglomerated powder, not spherical powder.
본 발명은 상기와 같은 문제점을 해결하기 위한 것으로 플레이크 은 분말의 원료분말로써 구형이 아닌 응집형 분말을 사용함으로써 고농도(high Ag concentration) 제조가 가능하여 제조 비용이 낮고, 입도 제어가 용이하며, 두께가 얇고 평균 입경이 5μm 이상으로서 높은 종횡비를 갖는 플레이크 은 분말을 제조하는 방법을 제공하는 것이다. The present invention is to solve the above problems by using agglomerated powder rather than spherical powder as the raw material of the flake silver powder, it is possible to manufacture a high concentration (high Ag concentration), low manufacturing cost, easy to control the particle size, thickness It is to provide a method for producing a flake silver powder having a thin aspect ratio and an average particle diameter of 5 µm or more and having a high aspect ratio.
그러나 본 발명의 목적들은 상기에 언급된 목적으로 제한되지 않으며, 언급되지 않은 또 다른 목적들은 아래의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.
본 발명은 플레이크 은 분말 제조방법으로서, 원료분말로서 응집형 은 분말을 사용하여 비즈를 통한 밀링으로 플레이크화된 분말을 얻는 플레이크화 단계(S2);를 포함하며, 상기 응집형 은 분말은 입경이 0.5 내지 2.0μm 인 은 입자가 응집되어, 평균 입경이 5.0 내지 20.0μm, 비표면적이 0.1 내지 0.6m2/g인 은 분말인 플레이크 은 분말 제조방법을 제공한다. The present invention provides a method for producing flake silver powder, comprising a flaked step (S2) of obtaining a flake powder by milling through beads using agglomerated silver powder as a raw material powder, the agglomerated silver powder has a particle size The silver particle which is 0.5-2.0 micrometers aggregates, and it provides the manufacturing method of the flake silver powder which is a silver powder with an average particle diameter of 5.0-20.0 micrometers, and a specific surface area of 0.1-0.6m <2> / g.
또한 상기 플레이크화 하는 단계(S3); 이후에, 플레이크화된 분말을 비즈와 분리하고, 세척, 건조 및 해쇄하여 플레이크 은 분말을 얻는 후처리 단계(S4);를 더 포함하여, 평균 입경(D50)이 5.0 내지 15.0μm이고, 탭밀도 2.5g/cc이하, 두께 300nm 이하인 플레이크 은 분말을 얻는 플레이크 은 분말 제조방법을 제공한다.In addition, the flakes step (S3); Thereafter, the flake powder is separated from the beads, washed, dried and pulverized to obtain a flake silver powder (S4); further comprising an average particle diameter (D50) of 5.0 to 15.0 µm and a tap density. Provided is a method for producing flake silver powder, which obtains flake silver powder of 2.5 g / cc or less and a thickness of 300 nm or less.
또한 상기 플레이크화 하는 단계(S3); 이후에, 플레이크화된 분말을 비즈와 분리하고, 세척, 건조 및 해쇄하여 플레이크 은 분말을 얻는 후처리 단계(S4)를 더 포함하여, 종횡비(평균입경(D50)/두께)가 15 이상인 플레이크 은 분말을 얻는 플레이크 은 분말 제조방법을 제공한다.In addition, the flakes step (S3); Thereafter, the flaked powder is further separated from the beads, washed, dried and pulverized to obtain a flake silver powder, further comprising a post-treatment step (S4), where the flake silver having an aspect ratio (average particle diameter (D50) / thickness) of 15 or more is obtained. Flake obtaining powder provides a powder production method.
또한 상기 플레이크화 하는 단계(S2)는 상기 응집형 은 분말을 슬러리화하고, 1 내지 5mm의 비즈를 이용하여 3 내지 6시간 동안 300 내지 700rpm 속도로 밀링하는 단계인 것을 특징으로 하는 플레이크 은 분말 제조방법을 제공한다.In addition, the flakes step (S2) is a slurry of the aggregated silver powder, flake silver powder manufacturing, characterized in that the step of milling at 300 to 700rpm speed for 3 to 6 hours using beads of 1 to 5mm Provide a method.
또한 상기 플레이크화 단계(S2); 이전에, 은(Ag)을 포함하는 은 소스 용액에 환원제를 포함하는 환원 용액을 투입하여 응집형 은 분말을 제조하는 원료분말 제조단계(S1);를 더 포함하고, 상기 은 소스 용액은 상기 은(Ag)의 함량 대비 암모니아를 0.4 내지 0.7 당량으로 포함하는 용액인 것을 특징으로 하는 플레이크 은 분말 제조방법을 제공한다.In addition, the flakes step (S2); Previously, a raw powder manufacturing step (S1) of preparing agglomerated silver powder by adding a reducing solution containing a reducing agent to a silver source solution containing silver (Ag); and the silver source solution further comprises the silver It provides a method for producing a flake silver powder, characterized in that the solution containing 0.4 to 0.7 equivalents of ammonia relative to the content of (Ag).
또한 상기 환원 용액은 단일 종류의 환원제를 포함하거나, 환원속도가 다른 2종 이상의 환원제를 포함하여, 제조되는 응집형 은 분말의 입경을 조절하는 것을 특징으로 하는 플레이크 은 분말 제조방법을 제공한다. In addition, the reducing solution includes a single type of reducing agent, or includes two or more kinds of reducing agents having different reduction rates, to provide a method for producing flake silver powder, characterized in that to control the particle size of the aggregated silver powder produced.
또한 본 발명은 입경이 0.5 내지 2.0μm 인 은 입자가 응집되어, 평균 입경이 5.0 내지 20.0μm, 비표면적이 0.1 내지 0.6m2/g인 응집형 은 분말을 사용하여 비즈를 통한 밀링으로 플레이크화된 분말인 플레이크 은 분말을 제공한다.In the present invention, silver particles having a particle size of 0.5 to 2.0 μm are aggregated, and the particles are flaked by milling through beads using agglomerated silver powder having an average particle size of 5.0 to 20.0 μm and a specific surface area of 0.1 to 0.6 m 2 / g. Flakes, which are ground powders, provide a powder.
또한 상기 플레이크 은 분말은 평균 입경(D50)이 5.0 내지 15.0μm이고, 탭밀도 2.5g/cc이하, 두께 300nm 이하인 플레이크 은 분말을 제공한다.In addition, the flake silver powder has a flake silver powder having an average particle diameter (D50) of 5.0 to 15.0 μm, a tap density of 2.5 g / cc or less, and a thickness of 300 nm or less.
또한 상기 플레이크 은 분말은 종횡비(평균입경(D50)/두께)가 15 이상인 것을 특징으로 하는 플레이크 은 분말을 제공한다. In addition, the flake silver powder provides a flake silver powder, characterized in that the aspect ratio (average particle diameter (D50) / thickness) is 15 or more.
또한 본 발명은 플레이크 은 분말; 및 바인더 수지를 포함하는 전도성 페이스트를 제공한다. In addition, the present invention is a flake silver powder; And it provides a conductive paste comprising a binder resin.
본 발명은 고농도 제조가 가능하고, 제조 시간을 줄여 비용을 낮출 수 있으며, 응집형 분말의 입도를 제어함으로써 제조되는 플레이크 은 분말 간의 압착을 최소화하며 입도 제어가 가능한, 두께가 얇고 평균 입경이 큰[즉, 높은 종횡비(입경/두께)를 갖는] 플레이크 은 분말의 제조방법을 제공할 수 있다.The present invention can be produced in a high concentration, can reduce the manufacturing time to reduce the cost, the flakes produced by controlling the particle size of the aggregated powder is a thin thickness and large average particle size [ In other words, it is possible to provide a method for producing flake silver powder having a high aspect ratio (particle size / thickness).
더욱 구체적으로 원료분말로써 일차입자경 0.5 내지 2.0μm, 평균입경 5.0 내지 20.0μm, 비표면적 0.1 내지 0.6 m2/g인 응집형 분말을 범용밀링설비 및 1 내지 5mm 비즈를 이용하여 낮은 제조비용으로 5.0 내지 15.0μm 평균입경(D50), 300nm 이하의 두께, 2.5g/cc 이하의 탭 밀도, 15 이상 종횡비를 가지는 플레이크 은 분말을 제조하는 방법을 제공할 수 있다. More specifically, as a raw material powder, agglomerated powders having a primary particle size of 0.5 to 2.0 μm, an average particle size of 5.0 to 20.0 μm, and a specific surface area of 0.1 to 0.6 m 2 / g are produced at a low production cost by using a general milling facility and 1 to 5 mm beads. It is possible to provide a method for producing a flake silver powder having an average particle diameter (D50) to 15.0 μm, a thickness of 300 nm or less, a tap density of 2.5 g / cc or less, and an aspect ratio of 15 or more.
도 1에 본 발명의 실시예 1에 따른 원료분말의 SEM 사진을 나타내었다. 1 shows an SEM photograph of the raw material powder according to Example 1 of the present invention.
도 2에 본 발명의 실시예 2에 따른 원료분말의 SEM 사진을 나타내었다. 2 shows an SEM photograph of the raw material powder according to Example 2 of the present invention.
도 3에 본 발명의 비교예 1에 따른 원료분말의 SEM 사진을 나타내었다. 3 shows a SEM photograph of the raw material powder according to Comparative Example 1 of the present invention.
도 4에 본 발명의 비교예 2에 따른 원료분말의 SEM 사진을 나타내었다. 4 shows a SEM photograph of the raw material powder according to Comparative Example 2 of the present invention.
도 5에 본 발명의 비교예 3에 따른 원료분말의 SEM 사진을 나타내었다. 5 is a SEM photograph of the raw material powder according to Comparative Example 3 of the present invention.
도 6에 본 발명의 실시예 1에 따른 플레이크 분말의 SEM 사진을 나타내었다. 6 is a SEM photograph of the flake powder according to Example 1 of the present invention.
도 7에 본 발명의 실시예 2에 따른 플레이크 분말의 SEM 사진을 나타내었다. 7 is a SEM photograph of the flake powder according to Example 2 of the present invention.
도 8에 본 발명의 비교예 1에 따른 플레이크 분말의 SEM 사진을 나타내었다. 8 is a SEM photograph of the flake powder according to Comparative Example 1 of the present invention.
도 9에 본 발명의 비교예 2에 따른 플레이크 분말의 SEM 사진을 나타내었다. 9 is a SEM photograph of the flake powder according to Comparative Example 2 of the present invention.
도 10에 본 발명의 비교예 3에 따른 플레이크 분말의 SEM 사진을 나타내었다. 10 is a SEM photograph of the flake powder according to Comparative Example 3 of the present invention.
이하에 본 발명을 상세하게 설명하기에 앞서, 본 명세서에 사용된 용어는 특정의 실시예를 기술하기 위한 것일 뿐 첨부하는 특허청구의 범위에 의해서만 한정되는 본 발명의 범위를 한정하려는 것은 아님을 이해하여야 한다. 본 명세서에 사용되는 모든 기술용어 및 과학용어는 다른 언급이 없는 한은 기술적으로 통상의 기술을 가진 자에게 일반적으로 이해되는 것과 동일한 의미를 가진다.Prior to describing the present invention in detail below, it is understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention, which is limited only by the scope of the appended claims. shall. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise indicated.
본 명세서 및 청구범위의 전반에 걸쳐, 다른 언급이 없는 한 포함(comprise, comprises, comprising)이라는 용어는 언급된 물건, 단계 또는 일군의 물건, 및 단계를 포함하는 것을 의미하고, 임의의 어떤 다른 물건, 단계 또는 일군의 물건 또는 일군의 단계를 배제하는 의미로 사용된 것은 아니다.Throughout this specification and claims, unless otherwise indicated, the termcomprise, constitutes, and configure means to include the referenced article, step, or group of articles, and step, and any other article It is not intended to exclude a stage or group of things or groups of stages.
한편, 본 발명의 여러 가지 실시예들은 명확한 반대의 지적이 없는 한 그 외의 어떤 다른 실시예들과 결합될 수 있다. 특히 바람직하거나 유리하다고 지시하는 어떤 특징도 바람직하거나 유리하다고 지시한 그 외의 어떤 특징 및 특징들과 결합될 수 있다. 이하, 첨부된 도면을 참조하여 본 발명의 실시예 및 이에 따른 효과를 설명하기로 한다.On the other hand, various embodiments of the present invention can be combined with any other embodiment unless clearly indicated to the contrary. Any feature indicated as particularly preferred or advantageous may be combined with any other feature and features indicated as preferred or advantageous. Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention and the effects thereof.
본 발명의 일실시예에 따른 플레이크 은 분말 제조방법은 원료 분말 제조단계(S1), 플레이크화 단계(S2) 및 후처리 단계(S3)를 포함하여 이루어진다. 본 발명에 따른 플레이크화 단계(S2)를 반드시 포함하고, 발명의 요지를 불필요하게 흐릴 수 있는 이외의 단계는 생략 가능하다.Flakes silver powder manufacturing method according to an embodiment of the present invention comprises a raw material powder manufacturing step (S1), flakes step (S2) and after-treatment step (S3). The flake forming step (S2) according to the present invention is necessarily included, and steps other than those which may unnecessarily obscure the subject matter of the invention can be omitted.
본 발명의 일실시예에 따른 원료분말 제조단계(S1)는 응집형 은 분말을 제조하는 단계로서, 구체적인 방법은 다음과 같다. Raw material powder manufacturing step (S1) according to an embodiment of the present invention is a step for producing agglomerated silver powder, the specific method is as follows.
은 소스 용액에 환원 용액을 첨가하여 은(Ag)을 환원시켜 은 입자(silver particle)를 석출한다. 즉 은(Ag)을 포함하는 은 소스 용액을 제조한 뒤, 환원제를 포함하는 환원 용액을 투입하여 은을 환원시켜 은 분말을 얻는다. 은 소스 용액이 교반되는 상태 하에서 환원 용액을 천천히 투입하거나, 일시에 투입할 수 있다.A silver solution is added to the silver source solution to reduce silver (Ag) to precipitate silver particles. That is, after preparing a silver source solution containing silver (Ag), a reducing solution containing a reducing agent is added to reduce the silver to obtain a silver powder. The reducing solution may be slowly added or temporarily added while the silver source solution is stirred.
상기의 은(Ag)을 포함하는 은 소스(Ag source) 용액은 환원제에 의해 은 입자가 석출될 수 있는 상태의 용액이라면 제한되지 않으며, 질산은 용액, 산화은 용액, 은 염 착체 또는 은 중간체 용액을 사용할 수 있다. 이하 은 염 착체를 예로 들어 설명한다.The silver source solution containing silver (Ag) is not limited as long as it is a solution in which silver particles can be precipitated by a reducing agent, and silver nitrate solution, silver oxide solution, silver salt complex or silver intermediate solution can be used. Can be. The following describes the silver salt complex as an example.
은 소스 용액 내의 pH는 암모니아를 이용하여 조절이 가능하며, 암모니아는 은 이온 함량 대비 0.4 내지 0.7당량을 사용한다. 암모니아의 함량이 0.4 당량 이하일 경우에는 은 소스 용액 내의 pH가 낮아 은 입자 석출 과정에서 투입된 환원제에 의한 환원 속도가 느려져 반응이 종결되지 않는 미반응이 발생할 수 있으며, 0.7당량 이상일 경우에는 은 입자 석출 과정에서 환원된 Ag0가 빠른 핵생성을 통하여 입자 미세화 및 구형화가 이루어져 본 특허에서 요구되는 응집형 분말을 얻기 어려운 문제가 있다. 또한 pH를 조절하는 방법으로 질산을 추가 혼합하여 사용하는 것도 좋다.The pH in the silver source solution can be adjusted using ammonia, and ammonia is used in an amount of 0.4 to 0.7 equivalents based on the content of silver ions. If the content of ammonia is 0.4 equivalent or less, the pH in the silver source solution is low, so the reduction rate by the reducing agent added in the precipitation process of silver particles may be slow, resulting in unreacted reaction that does not terminate.In the case of 0.7 equivalent or more, silver particle precipitation process may occur. There is a problem that the Ag 0 reduced in the fine particles and spheroidization through the rapid nucleation is difficult to obtain the aggregated powder required by the present patent. In addition, it is also good to use a mixture of nitric acid to adjust the pH.
상기 환원제는 아스코르브산, 하이드라진, 하이드로퀴논 및 포르말린으로 구성되는 군에서 선택되는 어느 1종 이상을 단독 또는 혼합상태로 사용할 수 있다. 환원제는 은 이온 함량 대비 1/3 내지 2/3 당량을 사용하는 것이 모든 이온을 반응시킬 수 있으며, 부족할 시 미반응이 일어나며, 과첨가 시 분말 내에 잔류 유기물이 침적될 수 있다. 바람직하게는 은 이온 함량 대비 0.5 당량을 사용하는 것이 좋다. 특히 환원제의 종류에 따라 제조되는 응집형 은 분말의 일차입자 크기를 조절할 수 있는데, 환원성이 큰 환원제를 사용하면 은 입자 석출 과정에서 핵생성 속도가 성장 속도보다 빨라 일차입자 크기가 작은 응집형 은 분말을 얻을 수 있다. 따라서 상기 환원 용액은 단일 종류의 환원제를 포함하거나, 환원속도가 다른 2종 이상의 환원제를 포함하여, 제조되는 응집형 은 분말의 입경을 조절할 수 있다. The reducing agent may be used alone or in combination of any one or more selected from the group consisting of ascorbic acid, hydrazine, hydroquinone and formalin. The reducing agent may react with all the ions by using 1/3 to 2/3 equivalents of the silver ion content, and when insufficient, unreacted reaction may occur, and residual organic matter may be deposited in the powder when over-added. Preferably 0.5 equivalents to the silver ion content is used. In particular, the primary particle size of the agglomerated silver powder produced according to the type of reducing agent can be controlled. The use of a reducing agent with a large reducing agent causes the nucleation rate to be faster than the growth rate during the precipitation of silver particles. Can be obtained. Therefore, the reducing solution may include a single type of reducing agent, or may include two or more kinds of reducing agents having different reduction rates, thereby controlling the particle diameter of the aggregated silver powder.
이 후 순수를 이용하여 세척 및 건조함으로써 원료분말을 제조하는 단계를 완료하여 일차입자경이 0.5 내지 2.0㎛이며, 평균 입경이 5.0 내지 20.0㎛, 비표면적이 0.1~0.6 m2/g인 응집형 은 분말을 얻는다. After completing the step of preparing the raw material powder by washing and drying with pure water, the aggregated silver having a primary particle size of 0.5 to 2.0㎛, average particle diameter of 5.0 to 20.0㎛, specific surface area of 0.1 ~ 0.6 m 2 / g Get powder.
본 발명의 일실시예에 따른 플레이크화 단계(S2)는 응집형 은 분말을 슬러리화시켜 비즈를 통한 기계적 밀링(milling)을 통해 플레이크화 하는 단계로서, 구체적인 방법은 다음과 같다. 응집형 은 분말은 상기 원료분말 제조단계(S1)를 통해 제조된 응집형 은 분말을 사용할 수 있으나 이에 제한되는 것은 아니며, 입경이 0.5 내지 2.0㎛인 일차 은 입자가 응집되어, 평균 입경이 5.0 내지 20.0㎛, 비표면적이 0.1~0.6 m2/g인 응집형 은 분말을 사용한다.Flaking step (S2) according to an embodiment of the present invention is a step to flake through a mechanical milling (milling) through the beads by slurrying the aggregated silver powder, a specific method is as follows. Agglomerated silver powder may be used agglomerated silver powder prepared through the raw material powder manufacturing step (S1), but is not limited thereto, and primary silver particles having a particle diameter of 0.5 to 2.0 μm are agglomerated, and the average particle diameter is 5.0 to Aggregated silver powder with a specific surface area of 0.1 to 0.6 m 2 / g is used at 20.0 μm.
응집형 은 분말을 슬러리화시킨다. 용매에 윤활제를 첨가하고, 윤활제가 용해될 때까지 교반한 뒤 응집형 은 분말을 용매 중에 분산시켜 슬러리를 생성한다. 원료분말의 특성에 따라 얻어지는 플레이크 은 분말의 특성이 크게 좌우된다. 응집형 은 분말이 분산되는 용매로는 물, 유기용매, 물과 유기용매의 혼합 용매를 이용할 수 있다. 입자 표면에의 오염 성분으로서의 용매 성분의 잔류를 고려할 때, 물에 가까운 조성의 용매를 사용하는 것이 좋다. 또는 슬러리 중에서의 응집형 은 분말의 분산성을 높여 플레이크화할 때의 품질 안정화를 고려할 때 유기용매를 단독으로 이용하는 것이 좋다. 유기용매로서는 메탄올, 에탄올, 에틸렌글리콜 등의 알코올류를 사용하는 것이 휘발성이 높아 플레이크 은 분말의 건조시 입자 표면에의 잔류가 적어 좋다. 플레이크화를 통한 생산 효율과 밀링 효율을 고려하여 용매에 대한 응집형 은 분말의 배합량을 적절하게 결정한다.Agglomerated silver powders are slurried. The lubricant is added to the solvent, stirred until the lubricant is dissolved, and then the aggregated silver powder is dispersed in the solvent to form a slurry. According to the characteristics of the raw material powder, the flakes obtained are highly dependent on the properties of the powder. As a solvent in which the aggregated silver powder is dispersed, a mixed solvent of water, an organic solvent, and water and an organic solvent can be used. In consideration of the residual of the solvent component as a contaminant on the particle surface, it is preferable to use a solvent having a composition close to water. Alternatively, it is preferable to use an organic solvent alone in consideration of the stabilization of the quality of the aggregated silver powder in the slurry to increase the dispersibility of the powder. The use of alcohols such as methanol, ethanol, ethylene glycol, etc. as the organic solvent is highly volatile, and the flake silver powder may have little residue on the particle surface during drying. In consideration of the production efficiency and the milling efficiency through flake formation, the blending amount of the aggregated silver powder in the solvent is appropriately determined.
상기 용매는 응집형 은 분말 100중량부에 대하여 25 내지 50 중량부 사용되며, 상기 윤활제는 응집형 은 분말 100중량부에 대하여 0.5 내지 5 중량부 사용된다.The solvent is used 25 to 50 parts by weight based on 100 parts by weight of the aggregated silver powder, the lubricant is used 0.5 to 5 parts by weight based on 100 parts by weight of the aggregated silver powder.
응집형 은 분말을 포함하는 슬러리를 어트리션밀을 이용하여 볼의 충격을 이용하여 밀링한다. 상기 어트리션밀은 수직형의 알루미나자에 샤프트, 지르코니아 볼을 채운 밀링장치이다. 상세한 밀링 과정은 하기 표 1과 같다.The slurry containing the aggregated silver powder is milled using an impact mill using the impact of the ball. The attrition mill is a milling apparatus in which a shaft and zirconia balls are filled in a vertical alumina. Detailed milling process is shown in Table 1 below.
분말 장입량Powder loading 500~800g500-800 g
볼 재질Ball material 지르코니아Zirconia
볼 사이즈Ball size 1~5mm1-5mm
볼 투입량Ball input Ag분말대비 250내지500wt.%250 to 500 wt.% Of Ag powder
밀링시간Milling time 3~6hrs3 ~ 6hrs
밀링속도Milling speed 300~700rpm300 ~ 700rpm
윤활제slush Fatty acid groupFatty acid group
용매menstruum 알코올 그룹Alcohol group
큰 입경과 높은 종횡비를 갖는 플레이크 은 분말을 얻기 위해서 구형 분말을 사용하는 경우 플레이크화 가공공정에서 제조 시간이 길고 슬러리 내의 은 농도가 낮아 제조 비용이 증가하며, 입경을 증대시키기 위해 장시간 밀링을 함으로써 플레이크 입자 간의 응집이 증가하여 높은 종횡비를 얻기 어려운 문제점이 있다. 반면, 응집형 분말을 사용하는 경우 구형 분말과 달리 슬러리 내 은 분말 농도를 높일 수 있기 때문에 batch당 생산량이 높고 동일 Ag slurry 농도에서는 제조시간을 줄일 수 있어 제조 비용을 낮출 수 있다. 또한 응집형 분말의 입도를 제어함으로써 제조되는 플레이크 은 분말 간의 압착을 최소화하며 입도 제어가 가능한, 두께가 얇고 평균 입경이 큰[즉, 높은 종횡비(입경/두께)를 갖는] 플레이크 은 분말의 제조방법을 제공할 수 있다.In the case of using spherical powder to obtain flake silver powder with large particle size and high aspect ratio, the production time is long due to the long production time in the flake processing process and the low concentration of silver in the slurry, and the flake by long milling to increase the particle size There is a problem that it is difficult to obtain a high aspect ratio because the aggregation between the particles increases. On the other hand, in the case of using agglomerated powder, unlike the spherical powder, since the silver powder concentration in the slurry can be increased, the yield per batch is high and the manufacturing time can be reduced at the same Ag slurry concentration, thereby lowering the manufacturing cost. In addition, the flake silver powder produced by controlling the particle size of the aggregated powder minimizes the squeeze between the powders, and the method of producing the flake silver powder having a thin thickness and a large average particle diameter (that is, having a high aspect ratio (particle size / thickness)), which can control the particle size. Can be provided.
본 발명의 일실시예에 따른 후처리 단계(S3)는 세척, 건조, 해쇄 공정을 포함하는 정제단계로서, 스크린(screen)을 이용하여 볼/슬러리를 분리하고 용매를 추가로 투입 후 교반하여 은 분말을 세척하고, 건조 및 해쇄한다. 더욱 구체적으로 제조된 플레이크 은 분말을 중력침강시킨 후 상층에 윤활제 등 유기물을 포함하는 용액을 제거한 후 슬러리를 80℃, 10hrs 동안 건조하는 단계일 수 있다. 세척 방법으로는 특별히 한정되는 것은 아니지만 슬러리로부터 고액 분리한 플레이크 은 분말을 세정액에 투입하고, 교반기 또는 초음파 세정기를 사용하여 교반한 후, 다시 고액 분리하여 플레이크 은 분말을 회수하는 방법이 이용될 수 있다. 또한 표면 흡착물을 충분히 제거하기 위해서는 세정액으로의 투입, 교반 세정, 및 고액 분리로 이루어지는 조작을 수회 반복하여 행하는 것이 바람직하다. 세정액은 물을 이용해도 좋지만, 윤활제 및 유기물을 효율적으로 제거하기 위하여 알칼리 수용액 또는 에탄올 수용액을 사용하는 것이 좋다.Post-treatment step (S3) according to an embodiment of the present invention is a purification step including a washing, drying, and disintegration process, by using a screen (screen) to separate the ball / slurry, and further adding a solvent and stirring silver The powder is washed, dried and crushed. More specifically, the prepared flake may be a step of gravity settling the powder, removing a solution containing an organic material such as a lubricant on the upper layer, and then drying the slurry at 80 ° C. for 10 hrs. The washing method is not particularly limited, but a method of recovering the flake silver powder by injecting the flake silver powder solid-liquid separated from the slurry into the washing liquid, stirring using a stirrer or an ultrasonic cleaner, and then solid-liquid separation again can be used. . In addition, in order to fully remove surface adsorbate, it is preferable to repeat operation which consists of input to washing | cleaning liquid, stirring washing | cleaning, and solid-liquid separation several times. Although the washing | cleaning liquid may use water, in order to remove a lubricant and organic substance efficiently, it is preferable to use aqueous alkali solution or ethanol aqueous solution.
상기 후처리를 거쳐 제조된 플레이크 은 분말은 평균 입경(D50) 5.0 내지 15.0μm, 두께 300nm 이하, 탭밀도 2.5g/cc 이하, 종횡비(평균 입경(D50)/두께) 15 이상을 갖는다. The flake silver powder prepared through the post-treatment has an average particle diameter (D50) of 5.0 to 15.0 μm, a thickness of 300 nm or less, a tap density of 2.5 g / cc or less, and an aspect ratio (average particle diameter (D50) / thickness) of 15 or more.
본 발명의 일실시예에 따른 플레이크 은 분말 제조방법에 의해 제조된 플레이크 은 분말은 멤브레인 터치 스위치(Membrane Touch Switch, MTS)나 인쇄회로기판(Printed Circuit Board, PCB), LED 라이트, 센서 전극 등 선폭이 크고 낮은 은 분말 함량으로 전극을 형성하는 전자 부품용 전도성 페이스트에 사용되는데 가장 적합하다. The flake silver powder manufactured by the method for manufacturing flake silver powder according to an embodiment of the present invention may be a membrane touch switch (Membrane Touch Switch, MTS), a printed circuit board (PCB), an LED light, a sensor electrode, or the like. This large and low silver powder content is most suitable for use in conductive pastes for electronic components forming electrodes.
실시예 및 실험예Examples and Experimental Examples
(1) 실시예 1(1) Example 1
상온의 순수 1765g에 질산은 용액 160g, 암모니아수(농도 25~40%) 50ml, 질산(40~60%) 15ml를 넣고 교반하여 용해시켜 pH 6.5~7.0의 은 소스 용액을 조제하였다. 한편 상온의 순수 2000g에 하이드로퀴논 50g, 하이드라진 0.5g을 넣고 교반하여 용해시켜 환원 용액을 조제하였다.160 g of silver nitrate solution, 50 ml of ammonia water (concentration 25-40%), and 15 ml of nitric acid (40-60%) were added to 1765 g of pure water at room temperature, and dissolved by stirring to prepare a silver sauce solution having a pH of 6.5-7.0. Meanwhile, 50 g of hydroquinone and 0.5 g of hydrazine were added to 2000 g of pure water at room temperature, followed by stirring to dissolve to prepare a reducing solution.
이어서, 은 소스 용액을 교반한 상태로 하고, 이 은 소스 용액에 환원 용액을 일괄 첨가하여, 첨가 종료 후부터 5분간 더 교반하여 혼합액 중에서 입자를 성장시켰다. 그 후 교반을 멈추고, 원심분리기를 이용하여 은 입자와 반응 용액을 고액 분리하고, 순수를 통해 세척 및 건조 하여 원료 분말을 제조하였다. 이상과 같은 공정으로 얻어진 응집형 은 분말의 SEM 사진을 도 1에 나타내었고, 표 2에 나타낸 것과 같이 일차 입자 지름이 0.5~1.5μm PSA에 의한 D50 8.0μm, 비표면적은 0.45 m2/g이었다. Subsequently, the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion | finish of addition, and grew particle | grains in the mixed liquid. After that, the stirring was stopped, the solid particles were separated from the silver particles and the reaction solution using a centrifuge, washed and dried through pure water to prepare a raw material powder. The SEM photograph of the aggregated silver powder obtained by the above process is shown in FIG. 1, and as shown in Table 2, the primary particle diameter was 8.0 μm with a D50 of 0.5 to 1.5 μm PSA, and the specific surface area was 0.45 m 2 / g. .
에탄올 180g에 윤활제 6g을 넣고 윤활제가 용해될 때까지 교반한 뒤, 상기 제조된 응집형 분말 600g을 넣고, 교반함으로써 은 슬러리 용액을 제조하였다. 표 1에 나타낸 것과 같은 조건, 즉 직경 1mm의 지르코니아 비즈 3.0kg을 attrition mill에 충진한 뒤, 은 슬러리 용액을 투입하여 700rpm의 회전속도로 기계적인 충격을 가하여 플레이크화를 행하였다.6 g of lubricant was added to 180 g of ethanol, and stirred until the lubricant was dissolved. Then, 600 g of the prepared aggregated powder was added and stirred to prepare a silver slurry solution. The conditions as shown in Table 1, that is, 3.0 kg of zirconia beads having a diameter of 1 mm were filled in an attrition mill, and then a silver slurry solution was added thereto to apply a mechanical shock at a rotational speed of 700 rpm to flake.
이 때 플레이크화는 6시간 진행하였다. 이 후, 스크린을 통해 비즈/슬러리를 분리 후 에탄올을 이용하여 분말을 세척하고, 중력침강시킨 후 윤활제 등 유기물을 포함하는 상등액을 제거한 후 80℃에서 12시간 동안 건조하였다.At this time, flakes were made for 6 hours. Subsequently, the beads / slurry was separated through the screen, the powder was washed with ethanol, gravity precipitated, and the supernatant containing organic matter such as lubricant was removed and dried at 80 ° C. for 12 hours.
상기와 같이 얻어진 플레이크 은 분말을 해쇄, sieving함으로써 하기의 특성을 얻었다. SEM 사진을 도 6에 나타내었다. 표 3에 나타낸 것과 같이 PSA에 의한 D10 2.9μm, D50 8.3μm, D90 17.7μm, 탭밀도 2.5g/cc, 두께 0.22μm , 종횡비는 37.72이었다.The following characteristics were obtained by pulverizing and sieving the flake silver powder obtained as mentioned above. The SEM photograph is shown in FIG. As shown in Table 3, D10 2.9 micrometers, D50 8.3 micrometers, D90 17.7 micrometers, tap density 2.5g / cc, thickness 0.22micrometer, and aspect ratio by PSA were 37.72.
(2) 실시예 2(2) Example 2
상온의 순수 1765g에 질산은 용액 160g, 암모니아수(농도 25%) 70ml, 질산(40~60%) 25ml를 넣고 교반하여 용해시켜 pH 6.5~7.0의 은 소스 용액을 조제하였다. 한편 상온의 순수 2000g에 하이드로퀴논 50g을 넣고 교반하여 용해시켜 환원 용액을 조제하였다.160 g of silver nitrate solution, 70 ml of ammonia water (concentration 25%), and 25 ml of nitric acid (40-60%) were added to 1765 g of pure water at room temperature, followed by stirring to prepare a silver sauce solution having a pH of 6.5-7.0. Meanwhile, 50 g of hydroquinone was added to 2000 g of room temperature pure water, and stirred to dissolve to prepare a reducing solution.
이어서, 은 소스 용액을 교반한 상태로 하고, 이 은 소스 용액에 환원 용액을 일괄 첨가하여, 첨가 종료 후부터 5분간 더 교반하여 혼합액 중에서 입자를 성장시켰다. 그 후 교반을 멈추고, 원심분리기를 이용하여 은 입자와 반응 용액을 고액 분리하고, 순수를 통해 세척 및 건조 하여 원료 분말을 제조하였다. 이상과 같은 공정으로 얻어진 응집형 은 분말의 SEM 사진을 도 2에 나타내었다. 표 2에 나타낸 것과 같이 일차 입자 지름이 0.8~2.0μm PSA에 의한 D50 16.9μm, 비표면적은 0.25 m2/g이었다.Subsequently, the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion | finish of addition, and grew particle | grains in the mixed liquid. After that, the stirring was stopped, the solid particles were separated from the silver particles and the reaction solution using a centrifuge, washed and dried through pure water to prepare a raw material powder. The SEM photograph of the aggregated silver powder obtained by the above process is shown in FIG. As shown in Table 2, the primary particle diameter was 16.9 µm and the specific surface area of D50 by 0.8-2.0 µm PSA was 0.25 m 2 / g.
상기 제조된 응집형 은 분말을 이용하여 실시예 1과 동일한 방법으로 플레이크화 및 후처리하였으며, 얻어진 플레이크 은 분말의 SEM 사진을 도 7에 나타내었다. 표 3에 나타낸 것과 같이 PSA에 의한 D10 4.9μm, D50 11.4μm, D90 19.4μm, 탭밀도는 2.2g/cc, 두께는 0.181 μm , 종횡비는 62.98 이었다.Flake and post-treatment in the same manner as in Example 1 using the prepared aggregated silver powder, the SEM photograph of the obtained flake silver powder is shown in FIG. As shown in Table 3, D10 4.9 micrometers, D50 11.4 micrometers, D90 19.4 micrometers by PSA, 2.2 g / cc of tap density, 0.181 micrometer of thickness, and 62.98 of aspect ratios were 62.98.
(3) 비교예 1 (3) Comparative Example 1
상온의 순수 960g에 질산은 용액 22ml, 암모니아(농도 25%) 18ml를 넣고 교반하여 용해시켜 은 소스 용액을 조제하였다. 한편 상온의 순수 1000g에 하이드로퀴논 5.5g을 넣고 교반하여 용해시켜 환원 용액을 조제하였다.22 ml of silver nitrate solution and 18 ml of ammonia (concentration 25%) were added to 960 g of pure water at room temperature, and the mixture was stirred and dissolved to prepare a silver sauce solution. Meanwhile, 5.5 g of hydroquinone was added to 1000 g of pure water at room temperature, and stirred to dissolve to prepare a reducing solution.
이어서, 은 소스 용액을 교반한 상태로 하고, 이 은 소스 용액에 환원 용액을 일괄 첨가하여, 첨가 종료 후부터 5분간 더 교반하여 혼합액 중에서 입자를 성장시켰다. 그 후 교반을 멈추고, 혼합액 중의 입자를 침강시킨 후, 혼합액의 상등액을 버리고 혼합액을 원심분리기를 이용하여 여과하고, 여재를 순수로 세정하고, 건조하여, 구형 은 분말을 얻었다. 이상과 같은 공정으로 얻어진 구형 은 분말의 SEM 사진을 도 3에 나타내었고, 그 특성은 표 2에 나타낸 것과 같이 D50이 1.13μm, 비표면적이 0.9 m2/g이었다. Subsequently, the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion | finish of addition, and grew particle | grains in the mixed liquid. Then, stirring was stopped, the particles in the mixed solution were allowed to settle, the supernatant of the mixed solution was discarded, the mixed solution was filtered using a centrifugal separator, the media was washed with pure water, and dried to obtain spherical silver powder. The SEM photograph of the spherical silver powder obtained by the above process was shown in FIG. 3, The characteristic was D50 of 1.13 micrometer and specific surface area of 0.9 m <2> / g as shown in Table 2.
상기 구형 은 분말을 이용하여 실시예 1와 동일한 방법으로 플레이크화 하여 플레이크 은 분말을 얻었으며, 얻어진 플레이크 은 분말의 SEM 사진을 도 8에 나타내었다. 표 3에 나타낸 것과 같이 PSA에 의한 D10 1.3μm, D50 4.5μm, D90 11.2μm, 탭밀도는 3.3g/cc, 분말두께는 0.42 μm , 종횡비는 10.71이었다. Flake silver powder was obtained by flake formation in the same manner as in Example 1 using the spherical silver powder, the SEM photograph of the obtained flake silver powder is shown in FIG. As shown in Table 3, D10 1.3μm, D50 4.5μm, D90 11.2μm, tap density 3.3g / cc, powder thickness 0.42μm and aspect ratio 10.71 by PSA.
(4) 비교예 2(4) Comparative Example 2
상온의 순수 960g에 질산은 용액 22mL, 암모니아(농도 25%) 30ml를 넣고 질산(40~60%) 45ml를 넣고 교반하여 용해시켜 은 소스 용액을 조제하였다. 한편 상온의 순수 1000g에 하이드로퀴논 5.5g을 넣고 교반하여 용해시켜 환원 용액을 조제하였다.22 mL of silver nitrate solution and 30 ml of ammonia (concentration 25%) were added to 960 g of pure water at room temperature, and 45 ml of nitric acid (40 to 60%) was added thereto, followed by stirring to dissolve the silver sauce solution. Meanwhile, 5.5 g of hydroquinone was added to 1000 g of pure water at room temperature, and stirred to dissolve to prepare a reducing solution.
이어서, 은 소스 용액을 교반한 상태로 하고, 이 은 소스 용액에 환원 용액을 일괄 첨가하여, 첨가 종료 후부터 5분간 더 교반하여 혼합액 중에서 입자를 성장시켰다. 그 후 교반을 멈추고, 혼합액 중의 입자를 침강시킨 후, 혼합액의 상등액을 버리고 혼합액을 원심분리기를 이용하여 여과하고, 여재를 순수로 세정하고, 건조하여, 구형 은 분말을 얻었다. 이상과 같은 공정으로 얻어진 구형 은 분말의 SEM 사진을 도 4에 나타내었고, 그 특성은 표 2에 나타낸 것과 같이 D50이 2.13μm, 비표면적이 0.3m2/g이었다.Subsequently, the silver source solution was stirred, the reduction solution was added collectively to this silver source solution, and it stirred for further 5 minutes after completion | finish of addition, and grew particle | grains in the mixed liquid. Then, stirring was stopped, the particles in the mixed solution were allowed to settle, the supernatant of the mixed solution was discarded, the mixed solution was filtered using a centrifugal separator, the media was washed with pure water, and dried to obtain spherical silver powder. The SEM photograph of the spherical silver powder obtained by the above process is shown in FIG. 4, and the characteristic was D50 of 2.13 micrometers and specific surface area of 0.3 m <2> / g as shown in Table 2.
상기 구형 은 분말을 이용하여 실시예 1 내지 실시예 2와 동일한 방법으로 플레이크화 하여 플레이크 은 분말을 얻었으며, 얻어진 플레이크 은 분말의 SEM 사진을 도 9에 나타내었다. 표 3에 나타낸 것과 같이 PSA에 의한 D10 2.7μm, D50 6.2μm, D90 13.1μm, 탭밀도는 3.0g/cc, 두께는 0.45 μm , 종횡비는 13.77이었다.Flake silver powder was obtained by flake forming in the same manner as Example 1 to Example 2 using the spherical silver powder, and the SEM photograph of the obtained flake silver powder is shown in FIG. 9. As shown in Table 3, D10 by 2.7 micrometers, D50 6.2 micrometers, D90 13.1 micrometers, tap density was 3.0 g / cc, thickness was 0.45 micrometer, and aspect ratio was 13.77.
*(5) 비교예 3* (5) Comparative Example 3
먼저 900g의 질산은 용액을 900ml의 순수에 용해시켜 질산은 수용액을 제조하고, 이것에 45% 농도의 NaOH 용액 370g을 한번에 첨가하여 교반함으로써 pH 10의 산화은 용액을 얻었다. 그리고 이 산화은 용액에 15% 농도의 환원 용액 350g을 80ml/min 속도로 첨가하여 교반함으로써 응집형 은 분말을 환원시켰다. 이 때 사용한 환원제는 포도당이며, 반응온도는 25℃를 유지하였다.First, 900 g of silver nitrate solution was dissolved in 900 ml of pure water to prepare a silver nitrate aqueous solution, and 370 g of 45% NaOH solution at 45% was added thereto and stirred to obtain a silver oxide solution of pH 10. The silver oxide solution was added with 350 g of a 15% reduction solution at a rate of 80 ml / min, followed by stirring to reduce the aggregated silver powder. The reducing agent used at this time was glucose, and the reaction temperature was maintained at 25 ° C.
상기와 같이 얻어진 응집형 은 분말 용액을 누체(Nutsche)를 이용하여 여과하고 5L의 순수를 이용하여 세정하고, 다시 80℃에서 10시간 건조하여 응집형 은 분말을 얻었다. 이상과 같은 공정으로 얻어진 응집형 은 분말의 SEM 사진을 도 5에 나타내었고, 그 특성은 표 2에 나타낸 것과 같이 1차 입자 지름이 0.2~0.5μm, D50이 4.8μm, 비표면적이 1.5 m2/g이었다.The agglomerated silver powder solution obtained as described above was filtered using Nutsche, washed with 5 L of pure water, and dried at 80 ° C. for 10 hours to obtain agglomerated silver powder. The SEM photograph of the aggregated silver powder obtained by the above process is shown in FIG. 5, and the characteristics thereof are as shown in Table 2, and the primary particle diameter is 0.2 to 0.5 μm, D50 is 4.8 μm, and the specific surface area is 1.5 m 2. / g.
상기 응집형 은 분말을 이용하여 실시예 1와 동일한 방법으로 플레이크화 하여 플레이크 은 분말을 얻었으며, 얻어진 플레이크 은 분말의 SEM 사진을 도 10에 나타내었다. 표 3에 나타낸 것과 같이 PSA에 의한 D10 1.4μm, D50 4.7μm, D90 13.3μm, 탭밀도는 3.5g/cc, 분말두께는 0.38μm, 종횡비는 12.37이었다. Flake silver powder was obtained by flake formation in the same manner as in Example 1 using the aggregated silver powder, and the SEM photograph of the obtained flake silver powder is shown in FIG. 10. As shown in Table 3, D10 1.4 micrometers, D50 4.7 micrometers, D90 13.3 micrometers by PSA, 3.5 g / cc of tap density, 0.38 micrometer of powder thickness, and 12.37 of aspect ratio.
또한 표 3에 제조된 플레이크 은 분말의 입도분석(D10, D50, D90), 두께 및 탭 밀도, 종횡비, 비표면적 특성 측정 자료를 나타내었으며, 도 6 내지 10에 실시예 및 비교예에 의해 제조된 플레이크 은 분말의 FE-SEM 사진을 나타내었다.In addition, the flakes prepared in Table 3 show the particle size analysis (D10, D50, D90), thickness and tap density, aspect ratio, and specific surface area measurement data of the powder, prepared by Examples and Comparative Examples in FIGS. The flakes showed FE-SEM photographs of the powder.
구 분division 형상shape 1차 입자경(μm)Primary particle size (μm) 평균입경(D50)(μm)Average particle size (D50) (μm) 비표면적(m2/g)Specific surface area (m 2 / g)
실시예 1Example 1 응집형Cohesive 0.5~1.50.5-1.5 8.08.0 0.450.45
실시예 2Example 2 응집형Cohesive 0.8~2.00.8-2.0 16.916.9 0.250.25
비교예1Comparative Example 1 구형rectangle -- 1.131.13 0.90.9
비교예2Comparative Example 2 구형rectangle -- 2.132.13 0.30.3
비교예3Comparative Example 3 응집형Cohesive 0.2~0.50.2-0.5 4.84.8 1.51.5
구 분division PSA(㎛)PSA (μm) 두께(㎛)Thickness (㎛) 탭 밀도(g/cc)Tap density (g / cc) 종횡비(입경/두께)Aspect ratio (particle size / thickness)
D10D10 D50D50 D90D90
실시예 1Example 1 2.92.9 8.38.3 17.717.7 0.220.22 2.52.5 37.7237.72
실시예 2Example 2 4.94.9 11.411.4 19.419.4 0.1810.181 2.22.2 62.9862.98
비교예1Comparative Example 1 1.31.3 4.54.5 11.211.2 0.420.42 3.33.3 10.7110.71
비교예2Comparative Example 2 2.72.7 6.26.2 13.113.1 0.450.45 3.03.0 13.7713.77
비교예3Comparative Example 3 1.41.4 4.74.7 13.313.3 0.380.38 3.53.5 12.3712.37
표 3에 나타난 것과 같이 실시예 1 및 2를 통하여 응집형 은 분말의 크기에 따라 제조되는 플레이크 은 분말의 입도제어가 가능한 것을 알 수 있으며, 제조된 플레이크 은 분말의 두께가 비교예들과 비교하여 얇고, 탭 밀도가 낮으며 또한 평균 입경도 크기 때문에 입경/두께의 종횡비가 15 이상으로 높은 것을 알 수 있다. As shown in Table 3, it can be seen through Examples 1 and 2 that the particle size of the flake silver powder can be controlled according to the size of the aggregated silver powder, and the thickness of the prepared flake silver powder can be compared with the comparative examples. It can be seen that the aspect ratio of the particle size / thickness is high (15 or more) because of its thinness, low tap density, and large average particle size.
반면, 비교예의 경우 분말 간의 상호 압착으로 인한 플레이크의 두께가 두껍고 높은 탭 밀도 및 낮은 평균 입경을 나타내는 것을 알 수 있다. 또한 비교예로 나타내지 않았지만, 일차입자 지름이 2μm급 이상인 응집형 은 분말을 사용하여 플레이크 은 분말을 제조하는 경우, 플레이크 은 분말의 입경이 너무 커 비히클(vehicle)에 의한 바인딩 특성이 좋지 못하게 되고, 이로 인해 페이스트의 분산성이 떨어져 인쇄성이 저하되고 전기 전도성이 감소하는 문제가 있다. On the other hand, in the comparative example, it can be seen that the thickness of the flakes due to the mutual compression between the powders is thick and shows a high tap density and a low average particle diameter. In addition, although not shown as a comparative example, when the flake silver powder is prepared using agglomerated silver powder having a primary particle diameter of 2μm or more, the particle size of the flake silver powder is too large, the binding characteristics by the vehicle is not good, As a result, there is a problem that the dispersibility of the paste is lowered and the printability is lowered and the electrical conductivity is reduced.
전술한 각 실시예에서 예시된 특징, 구조, 효과 등은 실시예들이 속하는 분야의 통상의 지식을 가지는 자에 의하여 다른 실시예들에 대해서도 조합 또는 변형되어 실시 가능하다. 따라서 이러한 조합과 변형에 관계된 내용들은 본 발명의 범위에 포함되는 것으로 해석되어야 할 것이다.Features, structures, effects, and the like illustrated in the above-described embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

Claims (10)

  1. 플레이크 은 분말 제조방법으로서,Flake is a powder manufacturing method
    원료분말로서 응집형 은 분말을 사용하여 비즈를 통한 밀링으로 플레이크화된 분말을 얻는 플레이크화 단계(S2);를 포함하며, It includes; flakes step (S2) of obtaining a flake powder by milling through beads using agglomerated silver powder as a raw material powder,
    상기 응집형 은 분말은 입경이 0.5 내지 2.0μm 인 은 입자가 응집되어, 평균 입경이 5.0 내지 20.0μm, 비표면적이 0.1 내지 0.6m2/g인 은 분말인 플레이크 은 분말 제조방법.The aggregated silver powder is a silver powder having a particle size of 0.5 to 2.0μm aggregated, the average particle diameter is 5.0 to 20.0μm, silver powder having a specific surface area of 0.1 to 0.6m 2 / g flake silver powder manufacturing method.
  2. 제1항에 있어서,The method of claim 1,
    상기 플레이크화 하는 단계(S3); 이후에,Flakes (S3); Since the,
    플레이크화된 분말을 비즈와 분리하고, 세척, 건조 및 해쇄하여 플레이크 은 분말을 얻는 후처리 단계(S4);를 더 포함하여,A post-treatment step (S4) of separating the flake powder from the beads, washing, drying and pulverizing to obtain the flake silver powder;
    평균 입경(D50)이 5.0 내지 15.0μm이고, 탭밀도 2.5g/cc이하, 두께 300nm 이하인 플레이크 은 분말을 얻는 플레이크 은 분말 제조방법.The flake silver powder manufacturing method which obtains the flake silver powder whose average particle diameter (D50) is 5.0-15.0 micrometers, tap density 2.5g / cc or less and thickness 300nm or less.
  3. 제2항에 있어서,The method of claim 2,
    상기 플레이크화 하는 단계(S3); 이후에,Flakes (S3); Since the,
    플레이크화된 분말을 비즈와 분리하고, 세척, 건조 및 해쇄하여 플레이크 은 분말을 얻는 후처리 단계(S4)를 더 포함하여,Further comprising a post-treatment step (S4) of separating the flake powder from the beads, washing, drying and pulverizing to obtain flake silver powder,
    종횡비(평균입경(D50)/두께)가 15 이상인 플레이크 은 분말을 얻는 플레이크 은 분말 제조방법.A flake silver powder manufacturing method which obtains flake silver powder whose aspect ratio (average particle diameter (D50) / thickness) is 15 or more.
  4. 제1항에 있어서,The method of claim 1,
    상기 플레이크화 하는 단계(S2)는 상기 응집형 은 분말을 슬러리화하고, 1 내지 5mm의 비즈를 이용하여 3 내지 6시간 동안 300 내지 700rpm 속도로 밀링하는 단계인 것을 특징으로 하는 플레이크 은 분말 제조방법.The flaking step (S2) is a method of producing a flake silver powder, characterized in that the slurry of the aggregated silver powder, and milling at 300 to 700rpm speed for 3 to 6 hours using beads of 1 to 5mm. .
  5. 제1항에 있어서,The method of claim 1,
    상기 플레이크화 단계(S2); 이전에,The flakes step (S2); Before,
    은(Ag)을 포함하는 은 소스 용액에 환원제를 포함하는 환원 용액을 투입하여 응집형 은 분말을 제조하는 원료분말 제조단계(S1);를 더 포함하고,Raw material powder manufacturing step (S1) for preparing agglomerated silver powder by adding a reducing solution containing a reducing agent to a silver source solution containing silver (Ag);
    상기 은 소스 용액은 상기 은(Ag)의 함량 대비 암모니아를 0.4 내지 0.7 당량으로 포함하는 용액인 것을 특징으로 하는 플레이크 은 분말 제조방법.The silver source solution is a flake silver powder manufacturing method, characterized in that the solution containing 0.4 to 0.7 equivalents of ammonia relative to the content of silver (Ag).
  6. 제 5항에 있어서,The method of claim 5,
    상기 환원 용액은 단일 종류의 환원제를 포함하거나, 환원속도가 다른 2종 이상의 환원제를 포함하여, 제조되는 응집형 은 분말의 입경을 조절하는 것을 특징으로 하는 플레이크 은 분말 제조방법.The reducing solution comprises a single type of reducing agent, or two or more kinds of reducing agents different reduction rate, flakes silver powder manufacturing method, characterized in that to control the particle size of the produced aggregated silver powder.
  7. 입경이 0.5 내지 2.0μm 인 은 입자가 응집되어, 평균 입경이 5.0 내지 20.0μm, 비표면적이 0.1 내지 0.6m2/g인 응집형 은 분말을 사용하여 비즈를 통한 밀링으로 플레이크화된 분말인 플레이크 은 분말. Silver flakes with a particle size of 0.5 to 2.0 μm aggregated, flakes are powders flake flake by milling through beads using agglomerated silver powder having an average particle size of 5.0 to 20.0 μm and a specific surface area of 0.1 to 0.6 m 2 / g Silver powder.
  8. 제7항에 있어서,The method of claim 7, wherein
    상기 플레이크 은 분말은 평균 입경(D50)이 5.0 내지 15.0μm이고, 탭밀도 2.5g/cc이하, 두께 300nm 이하인 플레이크 은 분말.The flake silver powder is a flake silver powder having an average particle diameter (D50) of 5.0 to 15.0 μm, a tap density of 2.5 g / cc or less and a thickness of 300 nm or less.
  9. 제8항에 있어서,The method of claim 8,
    상기 플레이크 은 분말은 종횡비(평균입경(D50)/두께)가 15 이상인 것을 특징으로 하는 플레이크 은 분말.The flake silver powder is flake silver powder, characterized in that the aspect ratio (average particle diameter (D50) / thickness) is 15 or more.
  10. 제7항의 플레이크 은 분말; 및 바인더 수지를 포함하는 전도성 페이스트.Flake silver powder of claim 7; And a binder resin.
PCT/KR2016/011091 2016-10-04 2016-10-04 Method for preparing flake-type silver powder by using agglomerated silver powder WO2018066723A1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007254845A (en) * 2006-03-24 2007-10-04 Mitsui Mining & Smelting Co Ltd Flake silver powder and its production method
KR20080046195A (en) * 2005-09-20 2008-05-26 미쓰이 긴조꾸 고교 가부시키가이샤 Process for producing flaky silver powder and flaky silver powder produced by the process
JP2012092442A (en) * 2010-10-01 2012-05-17 Dowa Electronics Materials Co Ltd Flaky silver powder, method for producing the same, and conductive paste
JP2014181399A (en) * 2013-03-21 2014-09-29 Sumitomo Metal Mining Co Ltd Method for manufacturing silver particles
JP2015183200A (en) * 2014-03-20 2015-10-22 住友金属鉱山株式会社 Silver powder and production method thereof
KR20170038467A (en) * 2015-09-30 2017-04-07 엘에스니꼬동제련 주식회사 The manufacturing method of flake silver powder using the agglomerated silver powder

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080046195A (en) * 2005-09-20 2008-05-26 미쓰이 긴조꾸 고교 가부시키가이샤 Process for producing flaky silver powder and flaky silver powder produced by the process
JP2007254845A (en) * 2006-03-24 2007-10-04 Mitsui Mining & Smelting Co Ltd Flake silver powder and its production method
JP2012092442A (en) * 2010-10-01 2012-05-17 Dowa Electronics Materials Co Ltd Flaky silver powder, method for producing the same, and conductive paste
JP2014181399A (en) * 2013-03-21 2014-09-29 Sumitomo Metal Mining Co Ltd Method for manufacturing silver particles
JP2015183200A (en) * 2014-03-20 2015-10-22 住友金属鉱山株式会社 Silver powder and production method thereof
KR20170038467A (en) * 2015-09-30 2017-04-07 엘에스니꼬동제련 주식회사 The manufacturing method of flake silver powder using the agglomerated silver powder

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