WO2019088510A1 - Method for producing silver powder - Google Patents

Method for producing silver powder Download PDF

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Publication number
WO2019088510A1
WO2019088510A1 PCT/KR2018/012185 KR2018012185W WO2019088510A1 WO 2019088510 A1 WO2019088510 A1 WO 2019088510A1 KR 2018012185 W KR2018012185 W KR 2018012185W WO 2019088510 A1 WO2019088510 A1 WO 2019088510A1
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Prior art keywords
silver powder
silver
washing
powder
solution
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PCT/KR2018/012185
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French (fr)
Korean (ko)
Inventor
김영환
이미영
진우민
강태훈
최재원
이창근
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엘에스니꼬동제련 주식회사
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Publication of WO2019088510A1 publication Critical patent/WO2019088510A1/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
    • 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
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C8/00—Enamels; Glazes; Fusion seal compositions being frit compositions having non-frit additions
    • C03C8/14—Glass frit mixtures having non-frit additions, e.g. opacifiers, colorants, mill-additions
    • 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
    • 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
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/25—Noble metals, i.e. Ag Au, Ir, Os, Pd, Pt, Rh, Ru
    • B22F2301/255—Silver or gold

Definitions

  • the present invention relates to a method for producing a silver powder for conductive paste for forming an electrode of an electronic component such as an electrode for a solar cell, an internal electrode of a multilayer capacitor, and a conductor pattern of a circuit board.
  • the conductive metal paste is a paste in which electricity is applied to a dried or baked coating film having a coating ability capable of forming a coating film and is dispersed with a conductive filler (metal filler) alone or in a glass frit in a vehicle made of a resin- It is widely used for the formation of an electric circuit or the formation of an external electrode of a ceramic capacitor.
  • Silver Paste is the most chemically stable and excellent in conductivity among the conductive paste of composite system, and has a wide range of applications in various fields such as conductive bonding and coating and fine circuit formation.
  • the electronic parts such as PCBs (Printed Circuit Boards), which are particularly important for reliability, the use of silver paste is used for bonding or coating materials for STH (Silver Through Hole), for internal electrodes in multilayer capacitors, Is widely used as an electrode material.
  • a slurry in which precipitated silver powder is dispersed can be obtained.
  • an organic reducing agent is added to a silver nitrate solution to reduce and precipitate silver powder to obtain a slurry in which silver powder is dispersed, and the silver powder slurry is dried The silver powder is recovered.
  • a powder manufacturing method includes a step of dewatering and drying a silver powder slurry.
  • the silver powder slurry is usually filtered and washed with water, dehydrated and then air dried, hot-air dried, or vacuum dried , And the dried product is crushed to recover silver powder.
  • the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a silver powder production method capable of increasing the cleaning efficiency of an insoluble organic substance generated at the time of reduction Method.
  • the present invention provides a cleaning method of silver powder comprising a washing step (S31) of washing a silver powder precipitated by a wet reduction method using a reducing agent with a cleaning solution containing a compound represented by the following formula .
  • x and y are each independently 1 or 2
  • R 1 , R 2 , R 3 and R 4 are each independently selected from the group consisting of hydrogen (H), C 1 -C 6 alkyl, C 1 -C 6 alkoxy, boranes, amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.)
  • H hydrogen
  • C 1 -C 6 alkyl C 1 -C 6 alkoxy
  • boranes amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.
  • the washing step (S31) is a step of washing the silver powder so that the compound is used in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the silver powder.
  • M is Na or Li
  • x is 1 or 2
  • y is 1
  • R 1 , R 2 , R 3 and R 4 are Characterized in that the washing is carried out using a washing solution comprising a compound comprising independently hydrogen (H), C 1 -C 6 alkyl, or boranes.
  • the reducing agent includes at least one selected from the group consisting of ascorbic acid, alkanolamine, hydroquinone, hydrazine and formalin.
  • the washing step (S31) is a step of dispersing the precipitated silver powder in a solvent, adding the washing solution to a solution in which the silver powder is dispersed, and mixing and stirring.
  • the present invention is an ion, ammonia (NH 3) and nitric acid (HNO 3)
  • the first reaction solution and for producing a second reaction solution containing a reducing agent in the reaction mixture prepared step (S21) and the first reaction solution containing the and A silver salt reducing step (S2) including a precipitation step (S22) of reacting the second reaction solution to obtain silver powder; And a washing step (S31) of washing the obtained silver powder with a washing solution containing the compound represented by the formula (1).
  • the silver powder washed according to the above method is characterized in that the degree of cohesion (D 50 / D SEM ) is 1.80 or less, the chromaticity of the supernatant dissolved in the NaOH solution is 200 PCU or less, and the alkali content is 80 ppm or less.
  • a metal powder including silver powder washed according to the above method; And a glass vehicle comprising a solvent and an organic binder; And a conductive paste.
  • a metal powder including silver powder washed according to the above method; Glass frit; And an organic vehicle including a solvent and an organic binder.
  • a silver powder when a silver powder is produced using a reducing agent according to a wet reduction method, an insoluble organic material generated after silver powder precipitation reaction is washed with an aqueous solution containing alkali metal borohydrides, It is possible to increase the cleaning efficiency at a low price, to reduce the silver powder aggregation to be produced, and to reduce the residual alkali metal content, thereby providing a silver powder having improved physical properties.
  • a conductive paste having improved sintering properties as a paste containing the silver powder having the improved physical properties and to form an electrode having excellent electrical conductivity.
  • FIG. 1 illustrates the process of measuring the chromaticity of the supernatant of a cleaned silver powder according to an embodiment of the present invention.
  • a method of manufacturing a silver powder according to an embodiment of the present invention includes: a silver salt producing step (S1); Silver salt reduction step (S2); Purification step such as filtration and washing (S3); And a surface treatment step (S4).
  • the method for producing a silver powder according to the present invention necessarily includes a silver salt reducing step (S2) and a purification step (S3), and the other steps may be omitted.
  • the silver salt preparation step S1 is a step of preparing a silver salt solution containing silver ions (Ag + ) by acid treatment of silver (Ag) in the form of ingots, comprising the steps of manufacturing, but can produce a powder to prepare a salt is passed through the step the solution directly, silver nitrate was purchased commercially (AgNO 3), the salt complex, or can proceed to the later steps, using the intermediate solution have.
  • the silver salt reducing step S2 is a step of reducing silver ions by adding a reducing agent and ammonia to a silver salt solution to precipitate silver particles, and silver ions, ammonia, and nitric acid (S21) for producing a second reaction solution containing a first reaction solution containing a reducing agent and a precipitation step (S22) for obtaining a silver powder by reacting the first reaction solution and the second reaction solution .
  • reaction solution preparation step (S21) ammonia and nitric acid are added to a silver salt solution containing silver ions, and the solution is stirred and dissolved to prepare a first reaction solution.
  • the silver ions are not limited as long as they are contained in the form of silver cations.
  • silver nitrate (AgNO 3 ), silver salt complex or silver intermediate may be used. It is preferable to use silver nitrate (AgNO 3 ).
  • AgNO 3 silver nitrate
  • the use of silver nitrate (AgNO 3 ) containing an ion will be described as an example.
  • Ammonia (NH 3 ) can be used in the form of an aqueous solution.
  • 25% ammonia aqueous solution 100 to 150 parts by weight of silver nitrate (AgNO 3 ) is added in 100 parts by weight.
  • the aqueous ammonia solution is added in an amount of less than 100 parts by weight, the reaction pH is low and silver ions are not completely reduced, or there is a problem in forming a uniform particle distribution.
  • the amount is more than 150 parts by weight, There is a problem that it becomes excessively high.
  • a 25% ammonia aqueous solution is added in an amount of 120 to 140 parts by weight based on 100 parts by weight of silver nitrate (AgNO 3 ).
  • the ammonia includes a derivative thereof.
  • the nitric acid (HNO 3 ) can be used in the form of an aqueous solution.
  • 60% nitric acid aqueous solution 40 to 120 parts by weight are added to 100 parts by weight of silver nitrate (AgNO 3 ).
  • the amount of the nitric acid (HNO 3 ) is less than 40 parts by weight, it is difficult to control the size of the powder.
  • the amount of the nitric acid (HNO 3 ) is more than 120 parts by weight, have.
  • a 60% nitric acid aqueous solution is added in an amount of 80 to 100 parts by weight based on 100 parts by weight of silver nitrate (AgNO 3 ).
  • the nitric acid includes a derivative thereof.
  • the first reaction solution containing silver ions, ammonia and nitric acid can be prepared in an aqueous solution state by adding a silver ion, an aqueous ammonia solution and an aqueous nitric acid solution to a solvent such as water and dissolving them by stirring to form a slurry form .
  • the reaction solution preparation step (S21) according to an embodiment of the present invention also produces a second reaction solution containing a reducing agent.
  • the reducing agent may be at least one member selected from the group consisting of ascorbic acid, alkanolamine, hydroquinone, hydrazine and formalin, and among them, hydroquinone can be preferably selected.
  • the content of the reducing agent is preferably 10 to 20 parts by weight based on 100 parts by weight of silver nitrate (AgNO 3 ) contained in the first reaction solution. If less than 10 parts by weight is used, silver ions may not be reduced at all, and when used in excess of 20 parts by weight, organic matter content increases.
  • the second reaction liquid is prepared by using 14 to 16 parts by weight of a reducing agent per 100 parts by weight of silver nitrate.
  • the second reaction solution containing a reducing agent can be prepared in an aqueous solution state by adding a reducing agent to a solvent such as water and dissolving it by stirring.
  • the precipitation step (S22) is a step of reacting the first reaction solution and the second reaction solution to obtain a silver powder, wherein the first reaction solution produced by the reaction solution production step (S21)
  • the second reaction solution may be slowly added dropwise or the reaction may be carried out in a batch.
  • the particles are added in a batch and further stirred for 5 minutes to 10 minutes to grow the particles in the mixed solution, so that the reduction reaction can be terminated in a short period of time to prevent agglomeration of the particles and increase dispersibility.
  • the silver powder dispersed in the aqueous solution or slurry is separated by filtration or the like after completing the silver particle precipitation reaction through the silver salt reducing step S2, And washing (S31), after washing, again dispersing the silver powder in the solvent and washing the silver powder with the washing solution in the dispersed solution.
  • the cleaning step S31 is a step of washing the precipitated silver particles using an aqueous solution containing alkali metal borohydrides as a cleaning solution, (S31) can clean the insoluble organic material generated after the silver powder precipitation reaction with high efficiency when the silver powder is produced using the reducing agent according to the wet reduction method.
  • the cleaning step S31 is a step of dispersing silver powder prepared in a solvent and adding an aqueous solution containing alkali metal borohydrides as a cleaning solution to the silver powder-dispersed solution, followed by mixing and stirring. Stirring the washing solution, filtering with a centrifugal separator, and washing the filter material with pure water.
  • the solvent in which the silver powder is dispersed may be water, ethanol, isopropyl alcohol, ethylene glycol hexyl ether, diethylene glycol, butyl ether propylene glycol, propyl ether and the like, preferably water.
  • the cleaning solution uses an aqueous solution containing alkali metal borohydrides represented by the following formula (1).
  • x and y are each independently 1 or 2
  • R 1 , R 2 , R 3 and R 4 are each independently selected from the group consisting of hydrogen (H), C 1 -C 6 alkyl, C 1 -C 6 alkoxy, boranes, amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.)
  • H hydrogen
  • C 1 -C 6 alkyl C 1 -C 6 alkoxy
  • boranes amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.
  • the reducing agent used in the reduction reaction remains on the surface of the silver powder produced as the poorly soluble organic material.
  • the reducing agent oxidized by the alkali metal borohydrides of the washing solution is reduced to a water-soluble state, It is possible to increase the cleaning efficiency of the washing machine.
  • Hydroquinone is oxidized to benzoquinone to be present as a by-product in a silver powder slurry during silver powder precipitation (reduction reaction), and benzoquinone Because it is a soluble organics, cleaning efficiency is very poor in pure water.
  • the cleaning solution is washed with an aqueous solution containing alkali metal hydride boron according to the present invention, the benzoquinone is reduced again to hydroquinone by the alkali metal borohydride, so that it can be washed in a small amount to provide high cleaning efficiency.
  • the wash solution is M a and comprises a Na or Li, and x is 1 or 2, y is 1, R 1, R 2, R 3 and R 4 are each independently hydrogen (H), C 1 C 6 alkyl, or boranes.
  • the cleaning solution is an aqueous solution containing a compound wherein M is Na, x and y are 1, and R 1 , R 2 , R 3 and R 4 are each hydrogen (H) .
  • washing step S31 silver powder prepared in a solvent is dispersed, and an aqueous solution containing alkali metal borohydrides is added as a washing solution to the silver powder-dispersed solution, followed by mixing and stirring. Is cleaned with pure water.
  • Silver powder is obtained by adding silver powder to a solvent having a mass of 3 to 5 times the mass of the silver powder and stirring the powder at 3000 to 4000 rpm for 10 to 30 minutes using a mixer. Preferably at 3000 to 3500 rpm for 15 to 25 minutes to obtain a solution in which the silver powder is dispersed.
  • the aqueous solution containing the alkali metal borohydrides represented by the above formula (1) is used in an amount such that the alkali metal borohydride is treated in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of silver powder to be washed.
  • the alkali metal borohydride is treated in an amount of less than 0.1 part by weight, insoluble organic matters remain on the surface of the powder, and when the organic matter content is high, there is a problem that the electrical conductivity is lowered in the finally used application, The surface treatment agent is not adsorbed well on the surface of the powder in the following surface treatment process, resulting in coating failure and deteriorated silver powder properties.
  • the alkali metal borohydride is used in an amount of 0.2 to 1.0 part by weight based on 100 parts by weight of silver powder to be washed.
  • the washing step (S31) is completed after completely removing the washing water from which the silver particles have been washed. If the water content is less than approximately 10%, the wash water is considered to be completely removed.
  • the purification step S3 may further include a drying step (S32) for drying after washing.
  • the drying step S32 is a step of recovering the silver particles washed through the washing solution and drying at 70 to 90 DEG C for 10 to 15 hours.
  • the purification step S3 may further include a smoothing step (S33) of smashing the silver particles after drying.
  • the surface treatment step S4 is a step of hydrophobizing the hydrophilic surface of the silver powder, and may be selectively performed.
  • an alcohol solution containing a fatty acid or a fatty acid salt is used as the surface treatment agent.
  • the alcohol may be methanol, ethanol, n-propanol, benzyl alcohol, terpineol or the like, preferably ethanol.
  • the fatty acid may be selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linolic acid, And arachidonic acid.
  • the fatty acid may be at least one selected from the group consisting of calcium hydroxide, sodium hydroxide, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, And a fatty acid salt which forms a salt with diethylamine, triethylamine, ethanolamine, diethanolamine or triethanolamine.
  • ammonium stearate in which stearic acid forms a salt with ammonia water is preferably used.
  • the powder is dried at 70 to 90 ° C for 10 to 15 hours, and then subjected to a pulverizing process using a jet mill to obtain a silver powder.
  • the powder is surface-treated, the powder should be well dispersed to achieve sufficient surface treatment. If the water content is low, the dispersion efficiency is lowered.
  • the present invention also provides a conductive paste comprising silver powder prepared according to an embodiment of the present invention.
  • the conductive paste includes a metal powder and an organic vehicle.
  • silver powder prepared according to one embodiment of the present invention is used as the metal powder.
  • the content of the metal powder is preferably 85 to 95 wt% based on the total weight of the conductive paste composition, considering the thickness of the electrode formed during printing and the line resistance of the electrode.
  • the organic vehicle preferably contains 5 to 15% by weight, based on the total weight of the conductive paste composition, of an organic binder mixed with 5 to 15% by weight of a solvent.
  • Examples of the organic binder include a cellulose ester compound such as cellulose acetate and cellulose acetate butyrate.
  • Examples of the cellulose ether compound include ethyl cellulose, methyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose , And hydroxyethyl methyl cellulose.
  • Examples of the acrylic compound include polyacrylamide, polymethacrylate, polymethylmethacrylate, and polyethylmethacrylate.
  • Examples of the vinyl compound include polyvinyl butyrate Polyvinyl acetate, polyvinyl alcohol, and the like. At least one or more organic binders may be selected and used.
  • Examples of the solvent used for diluting the composition include alcohols such as methanol, ethanol, n-propanol, benzyl alcohol and terpineol; Ketones such as acetone, methyl ethyl ketone, cyclohexanone, isophorone, and acetylacetone; Amides such as N, N-dimethylformamide and N, N-dimethylacetamide; Ethers such as tetrahydrofuran, dioxane, methyl cellosolve, diglyme and butyl carbitol; Esters such as methyl acetate, ethyl acetate, diethyl carbonate, TXIB (1-isopropyl-2,2-dimethyltrimethylene diisobutyrate), acetic acid carbitol and acetic acid butyl carbitol; Sulfoxides and sulfones such as dimethyl sulfoxide and sulfolane; Aliphatic
  • the conductive paste according to the present invention comprises a metal powder, a glass frit, and an organic vehicle.
  • silver powder prepared according to one embodiment of the present invention is used as the metal powder.
  • the content of the metal powder is preferably 85 to 95% by weight based on the total weight of the conductive paste composition, taking into account the electrode thickness formed during printing and the line resistance of the electrode.
  • the composition, particle diameter and shape of the glass frit are not particularly limited. It is possible to use not only flexible glass frit but also lead-free glass frit.
  • the content and content of the glass frit are 5 to 29 mol% of PbO, 20 to 34 mol% of TeO 2 , 3 to 20 mol% of Bi 2 O 3 , 20 mol% or less of SiO 2 , 10 mol% or less of B 2 O 3 , 10 to 20 mol% of an alkali metal (Li, Na, K, etc.) and an alkaline earth metal (Ca, Mg, etc.)
  • the average particle diameter of the glass frit is not limited, but it may have a particle diameter in the range of 0.5 to 10 mu m, and a mixture of various particles having different average particle diameters may be used.
  • at least one kind of glass frit has an average particle diameter (D50) of not less than 2 mu m and not more than 10 mu m.
  • the content of the glass frit is preferably 1 to 5% by weight based on the total weight of the conductive paste composition. If the amount is less than 1% by weight, incomplete firing may occur to increase electrical resistivity. If the amount exceeds 5% by weight, There is a possibility that the electrical resistivity becomes too high due to too much component.
  • the organic vehicle is not limited, but organic binders, solvents, and the like may be included. Solvents may sometimes be omitted.
  • the organic vehicle is not limited, but is preferably 1 to 10% by weight based on the total weight of the conductive paste composition.
  • the organic vehicle is required to have a property of keeping the metal powder and the glass frit uniformly mixed.
  • the conductive paste becomes homogeneous, And a property to suppress the flow and to improve the discharging property and the plate separability of the conductive paste from the screen plate.
  • the organic binder contained in the organic vehicle is not limited, but examples of the cellulose ester compound include cellulose acetate and cellulose acetate butyrate.
  • examples of the cellulose ether compound include ethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxyethylcellulose
  • examples of the acrylic compound include polyacrylamide, polymethacrylate, polymethylmethacrylate, and polyethylmethacrylate, and the like.
  • examples of the acrylic compound include polyacrylamide, polymethacrylate, polymethylmethacrylate, and polyethylmethacrylate
  • examples of vinyl based ones include polyvinyl butyral, polyvinyl acetate, polyvinyl alcohol, and the like. At least one or more organic binders may be selected and used.
  • Examples of the solvent used for diluting the composition include alpha-terpineol, texanol, dioctyl phthalate, dibutyl phthalate, cyclohexane, hexane, toluene, benzyl alcohol, dioxane, diethylene glycol, ethylene glycol monobutyl ether, ethylene Glycol monobutyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, and the like.
  • the conductive paste composition according to the present invention may further contain additives commonly known in the art, for example, dispersants, plasticizers, viscosity regulators, surfactants, oxidizing agents, metal oxides, metal organic compounds and the like.
  • the present invention also provides a method of forming an electrode of a solar cell and a solar cell electrode produced by the method, wherein the conductive paste is applied on a substrate, followed by drying and firing.
  • the methods used for producing substrates, printing, drying, and firing can be generally those used for manufacturing solar cells, except that conductive pastes containing silver powder having the above- to be.
  • the substrate may be a silicon wafer.
  • Production Example 1 was a powder
  • the first aqueous solution was stirred, and the second aqueous solution was added all at once to the first aqueous solution, and the mixture was further stirred for 5 minutes from the completion of the addition to grow particles in the mixed solution. Thereafter, the stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded, the mixed solution was filtered using a centrifugal separator, and the filter material was washed with pure water to obtain about 40 g of silver powder.
  • DMW De-Mineralized Water
  • 500 g of the silver powder prepared in the above-mentioned Production Example were put in a ball mill and dispersed in powder at 3300 rpm for 20 minutes using a homo-mixer (K & S company, Lab) .
  • the alkali metal borohydride aqueous solution was added to the silver powder-dispersed solution and further stirred for 5 minutes. Then, the mixture was filtered using a centrifugal separator, and the filter material was washed with pure water so that the electric conductivity was 50 ⁇ s or less.
  • the type and amount of the alkali metal borohydride aqueous solution are shown in Table 1 below, and the amount of alkali metal borohydride was expressed in terms of weight% of the alkali metal borohydride with respect to the weight of silver powder to be cleaned.
  • the temperature of the cleaning solution means room temperature except for the examples described separately.
  • the amount of NaOH to be used is shown in Table 1 below, and the amount of NaOH to be used is represented by the weight percentage of NaOH to the weight of silver powder to be washed.
  • NaOH (10% by weight of silver powder) was added to 2 L of pure water at room temperature, and NaOH was dissolved by homomixer (K & S company, Lab) for 5 minutes with stirring at 3300 rpm. 500 g of the silver powder prepared in the above Preparation Example was added and stirred for 20 minutes. Stirring was stopped, the mixture was filtered using a centrifugal separator, and the filter material was washed with pure water so that the electric conductivity was 50 ⁇ s or less.
  • the type and amount of the alkali metal borohydride aqueous solution are shown in Table 1 below, and the amount of alkali metal borohydride was expressed in terms of weight% of the alkali metal borohydride with respect to the weight of silver powder to be cleaned.
  • the temperature of the cleaning solution means room temperature except for the examples described separately.
  • PSA size D 50 , ⁇ m
  • SEM size D SEM , ⁇ m
  • SEM size was measured by measuring the diameter of each of 100 washed silver powders according to Examples and Comparative Examples and then averaging them.
  • the silver powder prepared by the examples and the comparative examples was put into 30 ml of ethanol, and the silver powder was dispersed in ethanol for 1 minute by ultrasonication, and the powder was put into a particle size analyzer to measure the PSA size.
  • the particle diameter at which the width is 50% from the largest particle diameter is expressed as D 50 based on the entire width of the graph.
  • Hot-NaOH aqueous solution evaluation to measure the cleaning efficiency. That is, after the organic matter remaining on the surface of the silver powder was dissolved using a hot-NaOH aqueous solution, the chromaticity of the supernatant was measured to quantify the concentration of the remaining organic matter. The higher the chromaticity of the supernatant, the higher the concentration of the remaining organic matter, which means that the washing is not good.
  • the evaluation method of the hot-NaOH aqueous solution is as follows.
  • the cleaned silver powder was placed in DMW and dispersed. Then, an ammonium stearate ethanol solution was added thereto, and the mixture was stirred at 4000 rpm for 20 minutes. After that, hot air drying was performed at 80 ° C for 12 hours, and the powder was surface-treated by jet milling to obtain silver powder.
  • the amount of organic matter remaining on the powder surface is reduced, so that the surface treating agent is adsorbed well on the powder surface in the surface treatment process after washing.
  • the water repellency (water repellency) of the silver powder was measured to determine the uniformity of the surface treatment, and it is indirectly known that the cleaning effect is excellent.
  • the agglomeration degree of the silver powder washed according to the example was lower than 1.80, the chromaticity of the supernatant was lower than 200PCU, and the alkali content was lower than 80 ppm, which was lower than that of the comparative example. It can be seen that the physical properties of the silver powder are the most excellent.
  • Comparative Example 2 shows an increase in washing efficiency due to a rise in the temperature of the washing liquid, thereby improving water repellency but increasing coagulation.
  • the conductive paste obtained in Preparation Example 2 was pattern printed on an alumina plate with a screen printing technique of 40 ⁇ m mesh, dried at about 300 ° C. for 25 seconds using a drying furnace, and then fired at 800 ° C. for 25 seconds using a firing furnace, .
  • the series resistance (Rs) of the electrode sample was measured and is shown in Table 3 below.
  • the series resistance of the electrode formed of the conductive paste containing the silver powder washed according to the example was 0.00140? Or less, which is lower than that of the comparative example.
  • the silver powder washed according to Examples 1 to 3 The best electrical conductivity is obtained.
  • the electrical properties are degraded as expected through the alkali content.

Abstract

When silver powder is produced by using a reducing agent according to a wet reduction method, the present invention has no risk of fire by washing insoluble organic materials generated after a silver powder precipitation reaction with an aqueous solution comprising alkali metal borohydrides, is capable of increasing cleaning efficiency at low costs, reduces aggregation of the silver powder to be produced, and reduces the content of residual alkali metals. Accordingly, it is possible to provide silver powder having improved physical properties.

Description

은 분말의 제조방법Method for producing silver powder
본 발명은 태양전지용 전극이나 적층 콘덴서의 내부전극, 회로기판의 도체 패턴 등 전자부품의 전극을 형성시키기 위한 도전성 페이스트용 은 분말의 제조방법에 관한 것이다.The present invention relates to a method for producing a silver powder for conductive paste for forming an electrode of an electronic component such as an electrode for a solar cell, an internal electrode of a multilayer capacitor, and a conductor pattern of a circuit board.
도전성 금속 페이스트는 도막 형성이 가능한 도포 적성을 갖고 건조 또는 소성된 도막에 전기가 흐르는 페이스트로서, 수지계 바인더와 용매로 이루어지는 비히클 중에 도전성 필러(금속 필러) 단독 또는 글라스 프릿과 함께 분산시킨 유동성 조성물이며, 전기 회로의 형성이나 세라믹 콘덴서의 외부 전극의 형성 등에 널리 사용되고 있다. The conductive metal paste is a paste in which electricity is applied to a dried or baked coating film having a coating ability capable of forming a coating film and is dispersed with a conductive filler (metal filler) alone or in a glass frit in a vehicle made of a resin- It is widely used for the formation of an electric circuit or the formation of an external electrode of a ceramic capacitor.
특히, 은 페이스트(Silver Paste)는 복합계 도전성 페이스트 중에서 가장 화학적으로 안정하고 도전성이 우수하여 전도성 접착 및 코팅용 그리고 미세회로 형성 등 여러 분야에 있어서 상당히 그 응용범위가 넓다. PCB(Printed Circuit Board)등과 같은 신뢰성을 특별히 중요시하는 전자부품에 있어서 은 페이스트의 용도는 STH(Silver Through Hole)용 접착 또는 코팅재 등으로 사용되며, 적층 콘덴서에서는 내부전극용으로, 최근에는 실리콘계 태양전지에서 전극 재료로 널리 사용되고 있다.In particular, Silver Paste is the most chemically stable and excellent in conductivity among the conductive paste of composite system, and has a wide range of applications in various fields such as conductive bonding and coating and fine circuit formation. In the electronic parts, such as PCBs (Printed Circuit Boards), which are particularly important for reliability, the use of silver paste is used for bonding or coating materials for STH (Silver Through Hole), for internal electrodes in multilayer capacitors, Is widely used as an electrode material.
일반적으로, 습식법에 따를 은 분말의 제조 방법에서는 석출한 은 분말이 분산된 슬러리(slurry)를 얻을 수 있다. 습식법에 따른 은 분말의 제조 방법으로서는 예를 들면, 질산은 용액(silver nitrate solution)에 유기 환원제를 첨가해, 은 분말을 환원 석출시켜, 은 분말이 분산된 슬러리를 얻고, 이 은 분말 슬러리를 탈수 건조하여 은 분말 회수한다. Generally, in the method for producing silver powder according to the wet method, a slurry in which precipitated silver powder is dispersed can be obtained. As a method of producing silver powder according to the wet method, for example, an organic reducing agent is added to a silver nitrate solution to reduce and precipitate silver powder to obtain a slurry in which silver powder is dispersed, and the silver powder slurry is dried The silver powder is recovered.
종래 은 분말 제조 방법은 은 분말 슬러리를 탈수 건조하는 공정에 있어서, 통상, 은 분말 슬러리를 여과하고 물로 세척하여 탈수한 후에 자연 건조(air drying), 열풍 건조(hot-air drying), 또는 진공 건조 등의 건조 공정을 거치고, 건조물을 해쇄하여 은 분말을 회수하고 있다. Conventionally, a powder manufacturing method includes a step of dewatering and drying a silver powder slurry. The silver powder slurry is usually filtered and washed with water, dehydrated and then air dried, hot-air dried, or vacuum dried , And the dried product is crushed to recover silver powder.
그러나, 유기 환원제를 사용하여 은 분말을 석출하고 물로만 세척 후 이를 단순 탈수하여 건조 공정을 거치는 경우 은 분말 표면에 난용성의 유기물이 잔존하게 되고, 유기물 함량이 높은 경우 최종적으로 사용되는 어플리케이션 내에서 전기 전도성이 저하되는 문제점이 있다. However, when the silver powder is precipitated by using an organic reducing agent, washed with water, and then subjected to a simple dehydration and drying process, insoluble organic matters remain on the powder surface. In the event that the organic material content is high, There is a problem that electric conductivity is lowered.
또한 종래에는 석출된 은 분말 표면에 잔존하는 난용성의 유기물을 제거하기 위하여 수산화나트륨(sodium hydroxide) 등의 알칼리 수용액이나 유기용제를 이용함으로써 효과적인 유기물의 세척이 가능하지만, 알칼리수에 포함되는 칼륨(K), 나트륨(Na) 등의 성분이 은 분말에 잔존하여 소결 특성 및 전기적 특성이 저하되는 경우 문제가 있으며, 유기 용제를 이용한 세척 시에는 인화성 액체로 인한 화재 위험성 및 제조비용이 증가하는 문제가 있다.In addition, in order to remove insoluble organic matter remaining on the surface of the precipitated silver powder, it is possible to effectively clean the organic material by using an aqueous solution of an alkali such as sodium hydroxide or an organic solvent. However, the potassium (K ), And sodium (Na) remain in the silver powder to lower the sintering property and electric characteristics, and there is a problem that the risk of fire due to the flammable liquid and the manufacturing cost are increased when the organic solvent is used for cleaning .
본 발명은 상기와 같은 문제점을 해결하기 위한 것으로 은 분말 제조방법으로서, 본 발명의 목적은 은 분말의 환원(석출) 시에 생성되는 난용성의 유기물의 세척 효율을 증대시킬 수 있는 은 분말의 제조방법을 제공하는 것이다. Disclosure of the Invention The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a silver powder production method capable of increasing the cleaning efficiency of an insoluble organic substance generated at the time of reduction Method.
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 can be clearly understood by those skilled in the art from the following description.
본 발명은 환원제를 이용하여 습식환원 방법에 의하여 석출된 은 분말을 하기 화학식 1로 표현되는 화합물을 포함하는 세척 용액을 이용하여 세척하는 세척단계(S31)를 포함하는 은 분말의 세척방법을 제공한다. The present invention provides a cleaning method of silver powder comprising a washing step (S31) of washing a silver powder precipitated by a wet reduction method using a reducing agent with a cleaning solution containing a compound represented by the following formula .
[화학식 1][Chemical Formula 1]
Figure PCTKR2018012185-appb-I000001
Figure PCTKR2018012185-appb-I000001
(이 때, M은 Li, Na 또는 K을 포함하며,(Wherein M comprises Li, Na or K,
x, y는 각각 독립적으로 1 또는 2이고,x and y are each independently 1 or 2,
R1, R2, R3 및 R4는 각각 독립적으로 수소(H), C1-C6 알킬(alkyl), C1-C6 알콕시(alkoxy), 보란(boranes), 아미노(amino), 히드록시(hydroxy), 히드록시메틸(hydroxymethyl), 카르복시(carboxy) 또는 메르캅토(mercapto)을 포함한다.)R 1 , R 2 , R 3 and R 4 are each independently selected from the group consisting of hydrogen (H), C 1 -C 6 alkyl, C 1 -C 6 alkoxy, boranes, amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.) The term "
또한 상기 세척단계(S31)는 상기 은 분말 100 중량부에 대하여 상기 화합물이 0.1 내지 2.0 중량부로 사용되도록 세척하는 단계인 것을 특징으로 한다.The washing step (S31) is a step of washing the silver powder so that the compound is used in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the silver powder.
또한 상기 세척단계(S31)는 상기 화학식 1로 표현되는 화합물 중 M이 Na 또는 Li를 포함하고, x는 1 또는 2이며, y는 1이고, R1, R2, R3 및 R4는 각각 독립적으로 수소(H), C1-C6 알킬(alkyl), 또는 보란(boranes)을 포함하는 화합물을 포함하는 세척 용액을 이용하여 세척하는 것을 특징으로 한다.In the washing step S31, M is Na or Li, x is 1 or 2, y is 1, and R 1 , R 2 , R 3 and R 4 are Characterized in that the washing is carried out using a washing solution comprising a compound comprising independently hydrogen (H), C 1 -C 6 alkyl, or boranes.
또한 상기 환원제는 아스코르브산, 알칸올아민, 하이드로퀴논, 히드라진 및 포르말린으로 이루어지는 군으로부터 선택되는 1종 이상을 포함하는 것을 특징으로 한다.Further, the reducing agent includes at least one selected from the group consisting of ascorbic acid, alkanolamine, hydroquinone, hydrazine and formalin.
또한 상기 세척단계(S31)는 용제에 상기 석출된 은 분말을 분산시키고, 상기 은 분말이 분산된 용액에 상기 세척 용액을 넣고 혼합 교반하는 단계인 것을 특징으로 한다.The washing step (S31) is a step of dispersing the precipitated silver powder in a solvent, adding the washing solution to a solution in which the silver powder is dispersed, and mixing and stirring.
또한 본 발명은 은 이온, 암모니아(NH3) 및 질산(HNO3)을 포함하는 제1 반응액 및 환원제를 포함하는 제2 반응액을 제조하는 반응액제조단계(S21) 및 제1 반응액 및 제2 반응액을 반응시켜 은 분말을 얻는 석출단계(S22)를 포함하는 은 염 환원단계(S2); 및 상기 얻어진 은 분말을 상기 화학식 1로 표현되는 화합물을 포함하는 세척 용액을 이용하여 세척하는 세척단계(S31);를 포함하는 은 분말 제조방법을 제공한다.In another aspect, the present invention is an ion, ammonia (NH 3) and nitric acid (HNO 3) The first reaction solution and for producing a second reaction solution containing a reducing agent in the reaction mixture prepared step (S21) and the first reaction solution containing the and A silver salt reducing step (S2) including a precipitation step (S22) of reacting the second reaction solution to obtain silver powder; And a washing step (S31) of washing the obtained silver powder with a washing solution containing the compound represented by the formula (1).
또한 상기 방법에 따라 세척된 은 분말로서, 응집도(D50/DSEM)가 1.80 이하이고, NaOH 용액에 용해시킨 상등액의 색도가 200PCU 이하이며, 알칼리 함량이 80ppm 이하인 것을 특징으로 한다.Also, the silver powder washed according to the above method is characterized in that the degree of cohesion (D 50 / D SEM ) is 1.80 or less, the chromaticity of the supernatant dissolved in the NaOH solution is 200 PCU or less, and the alkali content is 80 ppm or less.
또한 상기의 방법에 따라 세척된 은 분말을 포함하는 금속 분말; 및 용제 및 유기 바인더를 포함하는 유리 비히클; 을 포함하는 도전성 페이스트를 제공한다.A metal powder including silver powder washed according to the above method; And a glass vehicle comprising a solvent and an organic binder; And a conductive paste.
또한 상기의 방법에 따라 세척된 은 분말을 포함하는 금속 분말; 유리 프릿; 및 용제 및 유기 바인더를 포함하는 유기 비히클;을 포함하는 태양전지 전극용 도전성 페이스트를 제공한다. A metal powder including silver powder washed according to the above method; Glass frit; And an organic vehicle including a solvent and an organic binder.
본 발명은 습식환원 방법에 따라 환원제를 이용하여 은 분말을 제조하는 경우, 은 분말 석출 반응 후 생성되는 난용성의 유기물을 알칼리 금속 수소화붕소(Alkali metal borohydrides)를 포함하는 수용액으로 세척하여 화재 위험성이 없고, 낮은 가격으로 세척 효율을 증대시킬 수 있으며, 제조되는 은 분말 응집을 감소시키고, 잔존 알카리 금속 함량을 감소시켜 개선된 물성을 갖는 은 분말을 제공할 수 있다. According to the present invention, when a silver powder is produced using a reducing agent according to a wet reduction method, an insoluble organic material generated after silver powder precipitation reaction is washed with an aqueous solution containing alkali metal borohydrides, It is possible to increase the cleaning efficiency at a low price, to reduce the silver powder aggregation to be produced, and to reduce the residual alkali metal content, thereby providing a silver powder having improved physical properties.
또한 상기 개선된 물성을 갖는 은 분말을 포함하는 페이스트로서 소결 특성이 개선된 도전성 페이스트를 제공하여 이를 이용하여 우수한 전기 전도성을 갖는 전극을 형성할 수 있다.Also, it is possible to provide a conductive paste having improved sintering properties as a paste containing the silver powder having the improved physical properties and to form an electrode having excellent electrical conductivity.
도 1은 본 발명의 일실시예에 따라 세척된 은 분말의 상등액 색도 측정 과정을 나타낸 것이다.FIG. 1 illustrates the process of measuring the chromaticity of the supernatant of a cleaned silver powder according to an embodiment of the present invention.
도 2는 본 발명의 실시예 및 비교예에 따라 세척된 은 분말의 발수성 평가 기준을 나타낸 것이다. 2 shows the evaluation criteria of water repellency of washed silver powder according to Examples and Comparative Examples 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.Before describing the present invention in detail, it is to be 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 defined solely by 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 stated.
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, the word "comprise", "comprises", "comprising" means including a stated article, step or group of articles, and steps, , Step, or group of objects, or a group of steps.
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 contrary, the various embodiments of the present invention can be combined with any other embodiments as long as there is no clear counterpoint. Any feature that is specifically or advantageously indicated as being advantageous may be combined with any other feature or feature that is indicated as being preferred or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.
본 발명의 일실시예에 따른 은 분말의 제조방법은 은 염 제조단계(S1); 은 염 환원단계(S2); 여과 및 세척 등 정제단계(S3); 및 표면처리단계(S4);를 포함하여 이루어진다. 본 발명에 따른 은 분말의 제조방법은 은 염 환원단계(S2) 및 정제단계(S3)를 반드시 포함하고, 이외의 단계는 생략 가능하다. A method of manufacturing a silver powder according to an embodiment of the present invention includes: a silver salt producing step (S1); Silver salt reduction step (S2); Purification step such as filtration and washing (S3); And a surface treatment step (S4). The method for producing a silver powder according to the present invention necessarily includes a silver salt reducing step (S2) and a purification step (S3), and the other steps may be omitted.
본 발명의 일실시예에 따른 은 염 제조단계(S1)는 잉곳, 립, 그래뉼 형태의 은(silver, Ag)을 산처리하여 은 이온(Ag+)을 포함하는 은 염(silver salt) 용액을 제조하는 단계로서, 본 단계를 거쳐 은 염 용액을 직접 제조하여 은 분말을 제조할 수 있으나, 시중에서 구입한 질산은(AgNO3), 은 염 착체 또는 은 중간체 용액을 이용하여 이 후 단계를 진행할 수 있다.The silver salt preparation step S1 according to an embodiment of the present invention is a step of preparing a silver salt solution containing silver ions (Ag + ) by acid treatment of silver (Ag) in the form of ingots, comprising the steps of manufacturing, but can produce a powder to prepare a salt is passed through the step the solution directly, silver nitrate was purchased commercially (AgNO 3), the salt complex, or can proceed to the later steps, using the intermediate solution have.
본 발명의 일실시예에 따른 은 염 환원단계(S2)는 은 염 용액에 환원제 및 암모니아를 첨가하여 은 이온을 환원시켜 은 입자(silver particle)를 석출하는 단계로서, 은 이온, 암모니아 및 질산을 포함하는 제1 반응액 및 환원제를 포함하는 제2 반응액을 제조하는 반응액제조단계(S21) 및 제1 반응액 및 제2 반응액을 반응시켜 은 분말을 얻는 석출단계(S22)를 포함한다. The silver salt reducing step S2 according to an embodiment of the present invention is a step of reducing silver ions by adding a reducing agent and ammonia to a silver salt solution to precipitate silver particles, and silver ions, ammonia, and nitric acid (S21) for producing a second reaction solution containing a first reaction solution containing a reducing agent and a precipitation step (S22) for obtaining a silver powder by reacting the first reaction solution and the second reaction solution .
본 발명의 일실시예에 따른 반응액제조단계(S21)는 은 이온을 포함하는 은 염 용액에 암모니아 및 질산을 첨가하고 교반하여 용해시켜 제1 반응액을 제조한다. In the reaction solution preparation step (S21) according to an embodiment of the present invention, ammonia and nitric acid are added to a silver salt solution containing silver ions, and the solution is stirred and dissolved to prepare a first reaction solution.
상기 은 이온은 은 양이온의 형태로 포함되는 물질이라면 제한되지 않는다. 일례로 질산은(AgNO3), 은 염 착체 또는 은 중간체일 수 있다. 바람직하게는 질산은(AgNO3)을 사용하는 것이 좋다. 이하 은 이온을 포함하는 질산은(AgNO3)을 사용하는 것을 일 예시로 서술한다. The silver ions are not limited as long as they are contained in the form of silver cations. For example, silver nitrate (AgNO 3 ), silver salt complex or silver intermediate may be used. It is preferable to use silver nitrate (AgNO 3 ). Hereinafter, the use of silver nitrate (AgNO 3 ) containing an ion will be described as an example.
암모니아(NH3)는 수용액 형태로 사용될 수 있으며, 25% 암모니아 수용액을 사용하는 경우 질산은(AgNO3) 100 중량부에 대하여 100 내지 150 중량부로 첨가한다. 암모니아 수용액이 100 중량부 미만으로 첨가되는 경우 반응 pH가 낮아서 은 이온이 모두 환원되지 않거나, 균일한 입자 분포를 형성시키는데 문제가 있으며, 150 중량부를 초과하여 첨가되는 경우 제조된 은 분말 중 유기물 함량이 지나치게 높아지는 문제점이 있다. 바람직하게는 질산은(AgNO3) 100 중량부에 대하여 25% 암모니아 수용액을 120 내지 140 중량부로 첨가하는 것이 좋다. 상기 암모니아는 그 유도체를 포함한다. Ammonia (NH 3 ) can be used in the form of an aqueous solution. When 25% ammonia aqueous solution is used, 100 to 150 parts by weight of silver nitrate (AgNO 3 ) is added in 100 parts by weight. When the aqueous ammonia solution is added in an amount of less than 100 parts by weight, the reaction pH is low and silver ions are not completely reduced, or there is a problem in forming a uniform particle distribution. When the amount is more than 150 parts by weight, There is a problem that it becomes excessively high. Preferably, a 25% ammonia aqueous solution is added in an amount of 120 to 140 parts by weight based on 100 parts by weight of silver nitrate (AgNO 3 ). The ammonia includes a derivative thereof.
질산(HNO3)은 수용액 형태로 사용될 수 있으며, 60% 질산 수용액을 사용하는 경우 질산은(AgNO3) 100 중량부에 대하여 40 내지 120 중량부로 첨가한다. 질산(HNO3)이 40 중량부 미만으로 첨가되는 경우 은 분말의 크기(size)를 조절 하는데 어려움이 있으며, 질산(HNO3)이 120 중량부를 초과하여 첨가되는 경우 유기물 함량이 크게 증가하는 문제점이 있다. 바람직하게는 질산은(AgNO3) 100 중량부에 대하여 60% 질산 수용액을 80 내지 100 중량부로 첨가하는 것이 좋다. 상기 질산은 그 유도체를 포함한다. The nitric acid (HNO 3 ) can be used in the form of an aqueous solution. When 60% nitric acid aqueous solution is used, 40 to 120 parts by weight are added to 100 parts by weight of silver nitrate (AgNO 3 ). When the amount of the nitric acid (HNO 3 ) is less than 40 parts by weight, it is difficult to control the size of the powder. When the amount of the nitric acid (HNO 3 ) is more than 120 parts by weight, have. Preferably, a 60% nitric acid aqueous solution is added in an amount of 80 to 100 parts by weight based on 100 parts by weight of silver nitrate (AgNO 3 ). The nitric acid includes a derivative thereof.
은 이온, 암모니아 및 질산을 포함하는 제1 반응액은 물 등의 용제에 은 이온, 암모니아 수용액 및 질산 수용액을 첨가하고 교반하여 용해시켜 수용액 상태로 제조될 수 있으며, 또한 슬러리 형태로 제조될 수 있다. The first reaction solution containing silver ions, ammonia and nitric acid can be prepared in an aqueous solution state by adding a silver ion, an aqueous ammonia solution and an aqueous nitric acid solution to a solvent such as water and dissolving them by stirring to form a slurry form .
본 발명의 일실시예에 따른 반응액제조단계(S21)는 또한 환원제를 포함하는 제2 반응액을 제조한다. The reaction solution preparation step (S21) according to an embodiment of the present invention also produces a second reaction solution containing a reducing agent.
상기 환원제는 아스코르브산, 알칸올아민, 하이드로퀴논, 히드라진 및 포르말린으로 이루어지는 군으로부터 선택되는 1종 이상일 수 있으며, 이 중에서 하이드로퀴논을 바람직하게 선택할 수 있다. 환원제의 함량은 제1 반응액에 포함되는 질산은(AgNO3) 100 중량부에 대하여 10 내지 20 중량부로 포함되는 것이 바람직하다. 10 중량부 미만을 사용하는 경우, 은 이온이 모두 환원되지 않을 수 있고, 20 중량부를 초과하여 사용하는 경우 유기물 함량이 증가하는 문제가 있다. 바람직하게는 질산은 100 중량부에 대하여 환원제를 14 내지 16 중량부 사용하여 제2 반응액을 제조하는 것이 좋다. The reducing agent may be at least one member selected from the group consisting of ascorbic acid, alkanolamine, hydroquinone, hydrazine and formalin, and among them, hydroquinone can be preferably selected. The content of the reducing agent is preferably 10 to 20 parts by weight based on 100 parts by weight of silver nitrate (AgNO 3 ) contained in the first reaction solution. If less than 10 parts by weight is used, silver ions may not be reduced at all, and when used in excess of 20 parts by weight, organic matter content increases. Preferably, the second reaction liquid is prepared by using 14 to 16 parts by weight of a reducing agent per 100 parts by weight of silver nitrate.
환원제를 포함하는 제2 반응액은 물 등의 용매에 환원제를 첨가하고 교반하여 용해시켜 수용액 상태로 제조될 수 있다. The second reaction solution containing a reducing agent can be prepared in an aqueous solution state by adding a reducing agent to a solvent such as water and dissolving it by stirring.
본 발명의 일실시예에 따른 석출단계(S22)는 제1 반응액 및 제2 반응액을 반응시켜 은 분말을 얻는 단계로서, 반응액제조단계(S21)에 의해 제조된 제1 반응액을 교반하는 상태에서 제2 반응액을 천천히 적가하거나, 일괄 첨가하여 반응시킬 수 있다. 바람직하기로는 일괄 첨가한 후 5분 내지 10분간 더 교반하여 혼합액 중에서 입자를 성장시키는 것이 빠른 시간 내에 환원 반응이 일괄 종료되어 입자끼리의 응집을 방지하고 분산성을 높일 수 있어 좋다.The precipitation step (S22) according to an embodiment of the present invention is a step of reacting the first reaction solution and the second reaction solution to obtain a silver powder, wherein the first reaction solution produced by the reaction solution production step (S21) The second reaction solution may be slowly added dropwise or the reaction may be carried out in a batch. Preferably, the particles are added in a batch and further stirred for 5 minutes to 10 minutes to grow the particles in the mixed solution, so that the reduction reaction can be terminated in a short period of time to prevent agglomeration of the particles and increase dispersibility.
본 발명의 일실시예에 따른 정제단계(S3)는 은 염 환원단계(S2)를 통해 은 입자 석출 반응을 완료한 후 수용액 또는 슬러리 내에 분산되어 있는 은 분말을 여과 등을 이용하여 분리하고 순수로 세척한 이후에, 다시 은 분말을 용제에 분산시켜 은 분말이 분산된 용액에 세척 용액으로 세척하는 세척단계(S31)를 포함한다. In the refining step S3 according to an embodiment of the present invention, the silver powder dispersed in the aqueous solution or slurry is separated by filtration or the like after completing the silver particle precipitation reaction through the silver salt reducing step S2, And washing (S31), after washing, again dispersing the silver powder in the solvent and washing the silver powder with the washing solution in the dispersed solution.
본 발명의 일실시예에 따른 세척단계(S31)는 세척 용액으로서 알칼리 금속 수소화붕소(Alkali metal borohydrides)를 포함하는 수용액을 이용하여 상기 석출된 은 입자를 세척하는 단계로서, 본 발명에 따른 세척단계(S31)는 습식환원 방법에 따라 환원제를 이용하여 은 분말을 제조하는 경우, 은 분말 석출 반응 후 생성되는 난용성의 유기물을 높은 효율로 세척할 수 있다. The cleaning step S31 according to an embodiment of the present invention is a step of washing the precipitated silver particles using an aqueous solution containing alkali metal borohydrides as a cleaning solution, (S31) can clean the insoluble organic material generated after the silver powder precipitation reaction with high efficiency when the silver powder is produced using the reducing agent according to the wet reduction method.
세척단계(S31)는 우선 용제에 제조된 은 분말을 분산시키고, 상기 은 분말이 분산된 용액에 세척 용액으로서 알칼리 금속 수소화붕소(Alkali metal borohydrides)를 포함하는 수용액을 넣고 혼합 교반하는 단계이다. 세척 용액 교반 후 원심분리기를 이용하여 여과하고 여재를 순수로 세정하는 공정을 더 포함할 수 있다. The cleaning step S31 is a step of dispersing silver powder prepared in a solvent and adding an aqueous solution containing alkali metal borohydrides as a cleaning solution to the silver powder-dispersed solution, followed by mixing and stirring. Stirring the washing solution, filtering with a centrifugal separator, and washing the filter material with pure water.
상기 은 분말이 분산되는 용제는 물, 에탄올, 이소프로필알코올, 에틸렌글리콜 헥실에테르, 디에틸렌글리콜, 부틸에테르 프로필렌글리콜, 프로필에테르 등을 사용할 수 있으며, 바람직하게는 물을 사용한다.The solvent in which the silver powder is dispersed may be water, ethanol, isopropyl alcohol, ethylene glycol hexyl ether, diethylene glycol, butyl ether propylene glycol, propyl ether and the like, preferably water.
상기 세척 용액은 하기 화학식 1로 표현되는 알칼리 금속 수소화붕소(Alkali metal borohydrides)를 포함하는 수용액을 사용한다. The cleaning solution uses an aqueous solution containing alkali metal borohydrides represented by the following formula (1).
[화학식 1][Chemical Formula 1]
Figure PCTKR2018012185-appb-I000002
Figure PCTKR2018012185-appb-I000002
(이 때, M은 Li, Na 또는 K을 포함하며,(Wherein M comprises Li, Na or K,
x, y는 각각 독립적으로 1 또는 2이고,x and y are each independently 1 or 2,
R1, R2, R3 및 R4는 각각 독립적으로 수소(H), C1-C6 알킬(alkyl), C1-C6 알콕시(alkoxy), 보란(boranes), 아미노(amino), 히드록시(hydroxy), 히드록시메틸(hydroxymethyl), 카르복시(carboxy) 또는 메르캅토(mercapto)을 포함한다.)R 1 , R 2 , R 3 and R 4 are each independently selected from the group consisting of hydrogen (H), C 1 -C 6 alkyl, C 1 -C 6 alkoxy, boranes, amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.) The term "
상기 환원반응에서 사용되어 산화된 환원제는 난용성 유기물로서 생성된 은 분말 표면에 남게 되는데, 상기 세척 용액의 알칼리 금속 수소화붕소(Alkali metal borohydrides)에 의해 산화된 환원제를 다시 수용성 상태로 환원시킴으로써 잔존 유기물의 세척 효율을 높일 수 있다.The reducing agent used in the reduction reaction remains on the surface of the silver powder produced as the poorly soluble organic material. The reducing agent oxidized by the alkali metal borohydrides of the washing solution is reduced to a water-soluble state, It is possible to increase the cleaning efficiency of the washing machine.
하이드로퀴논을 환원제로 사용한 경우를 예로 들어 설명하면, 은 분말 석출 반응(환원 반응) 시 하이드로퀴논(hydroquinone)은 벤조퀴논(Benzoquinone)으로 산화되어 부산물로서 은 분말 슬러리에 존재하게 되며, 벤조퀴논은 난용성 유기물이기 때문에 순수로는 세척 효율이 매우 떨어진다. 본 발명에 따른 알칼리 금속 수소화붕소를 포함하는 수용액으로 세척하면 알칼리 금속 수소화붕소에 의하여 상기 벤조퀴논이 다시 하이드로퀴논으로 환원되기 때문에 적은 양으로도 세척이 가능하여 높은 세척 효율을 제공한다. Hydroquinone is oxidized to benzoquinone to be present as a by-product in a silver powder slurry during silver powder precipitation (reduction reaction), and benzoquinone Because it is a soluble organics, cleaning efficiency is very poor in pure water. When the cleaning solution is washed with an aqueous solution containing alkali metal hydride boron according to the present invention, the benzoquinone is reduced again to hydroquinone by the alkali metal borohydride, so that it can be washed in a small amount to provide high cleaning efficiency.
즉, NaOH 등의 알칼리 수용액을 사용하여 세척하는 경우와 세척 메커니즘에 차이가 있고, 은 분말 중량 대비 10% 중량의 알칼리 수용액을 사용하여 나타나는 세척 효과가 본 발명에 따른 세척 용액을 사용하면 은 분말 중량 대비 0.1~2% 중량의 알칼리 금속 수소화붕소 수용액을 사용하여도 유사한 세척 효과가 나오기 때문에 초기에 투입되는 알칼리의 양 자체가 적어 세척 후 잔존하는 알칼리의 함량 역시 적게 된다.That is, there is a difference between the case of washing with an alkaline aqueous solution such as NaOH and the washing mechanism, and the cleaning effect using 10% by weight of the alkaline aqueous solution as the weight of the silver powder is as follows. When the washing solution according to the present invention is used, A similar cleaning effect is obtained even when an aqueous solution of an alkali metal borohydride having a weight of 0.1 to 2% by weight is used, so that the amount of alkali remaining after washing is also small because the amount of alkali to be initially charged is small.
바람직하게는 상기 세척 용액은 M이 Na 또는 Li를 포함하고, x는 1 또는 2이며, y는 1이고, R1, R2, R3 및 R4는 각각 독립적으로 수소(H), C1-C6 알킬(alkyl), 또는 보란(boranes)을 포함하는 화합물을 포함하는 수용액인 것이 좋다. Preferably the wash solution is M a and comprises a Na or Li, and x is 1 or 2, y is 1, R 1, R 2, R 3 and R 4 are each independently hydrogen (H), C 1 C 6 alkyl, or boranes.
더욱 바람직하게는 상기 세척 용액은 M이 Na를 포함하고, x, y는 1이며, R1, R2, R3 및 R4는 각각 수소(H)를 포함하는 화합물을 포함하는 수용액인 것이 좋다. More preferably, the cleaning solution is an aqueous solution containing a compound wherein M is Na, x and y are 1, and R 1 , R 2 , R 3 and R 4 are each hydrogen (H) .
세척단계(S31)는 우선 용제에 제조된 은 분말을 분산시키고, 상기 은 분말이 분산된 용액에 세척 용액으로서 알칼리 금속 수소화붕소(Alkali metal borohydrides)를 포함하는 수용액을 넣고 혼합 교반한 후 여과하고 여재를 순수로 세정하는 단계이다. In the washing step S31, silver powder prepared in a solvent is dispersed, and an aqueous solution containing alkali metal borohydrides is added as a washing solution to the silver powder-dispersed solution, followed by mixing and stirring. Is cleaned with pure water.
은 분말이 분산된 용액은 은 분말의 질량 대비 3 내지 5배 질량의 용제에 은 분말을 넣은 후 믹서를 이용하여 3000 내지 4000rpm 으로 10 내지 30분간 교반하여 얻는다. 바람직하게는 3000 내지 3500rpm으로 15 내지 25분간 교반하여 은 분말이 분산된 용액을 얻는 것이 좋다. Silver powder is obtained by adding silver powder to a solvent having a mass of 3 to 5 times the mass of the silver powder and stirring the powder at 3000 to 4000 rpm for 10 to 30 minutes using a mixer. Preferably at 3000 to 3500 rpm for 15 to 25 minutes to obtain a solution in which the silver powder is dispersed.
상기 화학식 1로 표현되는 알칼리 금속 수소화붕소(Alkali metal borohydrides)를 포함하는 수용액은 세척되는 은 분말 100 중량부에 대하여 상기 알칼리 금속 수소화붕소가 0.1 내지 2.0 중량부로 처리되도록 하는 함량으로 사용된다. 알칼리 금속 수소화붕소를 0.1 중량부 미만으로 처리하는 경우 은 분말 표면에 난용성의 유기물이 잔존하게 되고 유기물 함량이 높은 경우 최종적으로 사용되는 어플리케이션 내에서 전기 전도성이 저하되는 문제점이 있고, 또한, 세척 공정 다음의 표면처리 공정에서 표면처리제가 은 분말 표면에 잘 흡착되지 않아 코팅 불량이 발생하여 은 분말 특성이 저하되는 문제점이 있다. 2.0 중량부를 초과하여 처리하는 경우 세척 효율은 증대되지 않는 반면 세척 공정에서 다량의 수소 기체가 발생하여 안전상 문제가 될 수 있고 제조 비용이 높아지는 문제가 있다. 바람직하게는 세척되는 은 분말 100 중량부에 대하여 알칼리 금속 수소화붕소가 0.2 내지 1.0 중량부로 처리되도록 하는 함량으로 사용하는 것이 좋다.The aqueous solution containing the alkali metal borohydrides represented by the above formula (1) is used in an amount such that the alkali metal borohydride is treated in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of silver powder to be washed. When the alkali metal borohydride is treated in an amount of less than 0.1 part by weight, insoluble organic matters remain on the surface of the powder, and when the organic matter content is high, there is a problem that the electrical conductivity is lowered in the finally used application, The surface treatment agent is not adsorbed well on the surface of the powder in the following surface treatment process, resulting in coating failure and deteriorated silver powder properties. In the case of treating more than 2.0 parts by weight, there is a problem that the cleaning efficiency is not increased but a large amount of hydrogen gas is generated in the washing process, which may cause a safety problem and increase the manufacturing cost. Preferably, the alkali metal borohydride is used in an amount of 0.2 to 1.0 part by weight based on 100 parts by weight of silver powder to be washed.
세척단계(S31)는 은 입자를 세척한 세척수를 완전히 제거를 한 후 완료된다. 대략 함수율 10% 미만인 경우 세척수를 완전히 제거한 것으로 간주한다. The washing step (S31) is completed after completely removing the washing water from which the silver particles have been washed. If the water content is less than approximately 10%, the wash water is considered to be completely removed.
또한 본 발명의 일실시예에 따른 정제단계(S3)는 세척 후 건조하는 건조단계(S32)를 더 포함할 수 있다. 건조단계(S32)는 세척액을 통해 세척된 은 입자를 회수하여 70 내지 90℃ 에서 10 내지 15시간 동안 건조하는 단계이다. Further, the purification step S3 according to an embodiment of the present invention may further include a drying step (S32) for drying after washing. The drying step S32 is a step of recovering the silver particles washed through the washing solution and drying at 70 to 90 DEG C for 10 to 15 hours.
또한 본 발명의 일실시예에 따른 정제단계(S3)는 건조 후 은 입자를 해쇄하는 해쇄단계(S33)를 더 포함할 수 있다. Further, the purification step S3 according to an embodiment of the present invention may further include a smoothing step (S33) of smashing the silver particles after drying.
본 발명의 일실시예에 따른 표면처리단계(S4)는 은 분말의 친수 표면을 소수화하는 단계로서, 선택적으로 이루어질 수 있다. 상기 표면처리제로서는 지방산 또는 지방산염을 포함하는 알코올 용액을 사용한다. 알코올은 메탄올, 에탄올, n-프로판올, 벤질알코올, 테르피네올(Terpineol) 등을 사용할 수 있으며, 바람직하게는 에탄올을 사용한다.The surface treatment step S4 according to an embodiment of the present invention is a step of hydrophobizing the hydrophilic surface of the silver powder, and may be selectively performed. As the surface treatment agent, an alcohol solution containing a fatty acid or a fatty acid salt is used. The alcohol may be methanol, ethanol, n-propanol, benzyl alcohol, terpineol or the like, preferably ethanol.
상기 지방산은 라우르산(lauric acid), 미리스틴산(myristic acid), 팔미틴산(palmitic acid), 스테아린산(Stearic Acid), 베헨산(behenic acid), 올레인산(oleic acid), 리놀산(linolic acid) 및 아라키돈산(arachidonic acid)으로 구성되는 군에서 선택되는 적어도 1종 이상을 포함한다. 바람직하게는 스테아린산(Stearic Acid)을 사용하는 것이 좋다.The fatty acid may be selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linolic acid, And arachidonic acid. The term " arachidonic acid " It is preferable to use stearic acid.
상기 지방산염은 상기 지방산이 수산화칼슘(calcium hydroxide), 수산화나트륨(sodium hydroxide), 암모니아(ammonia), 메틸아민(methylamine), 디에틸아민(dimethylamine), 트리메틸아민(trimethylamine), 에틸아민(ethylamine), 디에틸아민(diethylamine), 트리에틸아민(triethylamine), 에탄올아민(ethanolamine), 디에탄올아민(diethanolamine) 또는 트리에탄올아민(triethanolamine)과 염을 형성한 지방산염을 포함한다. 바람직하게는 스테아린산이 암모니아수와 염을 형성한 암모늄스테아레이트(ammonium stearate)를 사용하는 것이 좋다.The fatty acid may be at least one selected from the group consisting of calcium hydroxide, sodium hydroxide, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, And a fatty acid salt which forms a salt with diethylamine, triethylamine, ethanolamine, diethanolamine or triethanolamine. Preferably, ammonium stearate in which stearic acid forms a salt with ammonia water is preferably used.
이 후 70 내지 90℃에서 10 내지 15시간 건조한 후, 제트 밀(Jet mill)을 이용하여 해쇄 과정을 거쳐 은 분말을 얻을 수 있다. 은 분말을 표면처리할 때 분말의 분산이 잘 되어야 표면처리가 충분히 이루어지고, 함수율이 낮으면 분산 효율이 떨어지기 때문에 일정량을 함수율을 가지고 표면처리를 하는 것이 좋다. Thereafter, it is dried at 70 to 90 ° C for 10 to 15 hours, and then subjected to a pulverizing process using a jet mill to obtain a silver powder. When the powder is surface-treated, the powder should be well dispersed to achieve sufficient surface treatment. If the water content is low, the dispersion efficiency is lowered.
본 발명은 또한 본 발명의 일실시예에 따라 제조되는 은 분말을 포함하는 도전성 페이스트를 제공한다. 도전성 페이스트는 금속 분말 및 유기 비히클을 포함한다. The present invention also provides a conductive paste comprising silver powder prepared according to an embodiment of the present invention. The conductive paste includes a metal powder and an organic vehicle.
상기 금속 분말로는 본 발명의 일실시예에 따라 제조된 은 분말을 사용한다. 금속 분말의 함량은 인쇄 시 형성되는 전극 두께 및 전극의 선저항을 고려할 때 도전성 페이스트 조성물 총 중량을 기준으로 85 내지 95 중량% 포함되는 것이 바람직하다.As the metal powder, silver powder prepared according to one embodiment of the present invention is used. The content of the metal powder is preferably 85 to 95 wt% based on the total weight of the conductive paste composition, considering the thickness of the electrode formed during printing and the line resistance of the electrode.
상기 유기 비히클은 용제에 유기 바인더가 5 내지 15 중량%로 혼합된 것으로서, 도전성 페이스트 조성물 총 중량을 기준으로 5 내지 15 중량% 포함되는 것이 바람직하다. The organic vehicle preferably contains 5 to 15% by weight, based on the total weight of the conductive paste composition, of an organic binder mixed with 5 to 15% by weight of a solvent.
상기 유기 바인더는 셀룰로오스 에스테르계 화합물로 셀룰로오스 아세테이트, 셀룰로오스 아세테이트 부틸레이트 등을 예로 들 수 있으며, 셀룰로오스 에테르 화합물로는 에틸 셀룰로오스, 메틸 셀룰로오스, 하이드록시 플로필 셀룰로오스, 하이드록시 에틸 셀룰로오스, 하이드록시 프로필 메틸 셀룰로오스, 하이드록시 에틸 메틸 셀룰로오스 등을 예로 들 수 있으며, 아크릴계 화합물로는 폴리 아크릴아미드, 폴리 메타 아크릴레이트, 폴리 메틸 메타 아크릴레이트, 폴리 에틸 메타 아크릴레이트 등을 예로 들 수 있으며, 비닐계로는 폴리비닐 부티랄, 폴리비닐 아세테이트 그리고 폴리비닐 알코올 등을 예로 들 수 있다. 상기 유기 바인더들은 적어도 1종 이상 선택되어 사용될 수 있다. Examples of the organic binder include a cellulose ester compound such as cellulose acetate and cellulose acetate butyrate. Examples of the cellulose ether compound include ethyl cellulose, methyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose , And hydroxyethyl methyl cellulose. Examples of the acrylic compound include polyacrylamide, polymethacrylate, polymethylmethacrylate, and polyethylmethacrylate. Examples of the vinyl compound include polyvinyl butyrate Polyvinyl acetate, polyvinyl alcohol, and the like. At least one or more organic binders may be selected and used.
조성물의 희석을 위해 사용되는 용제로서는 메탄올, 에탄올, n-프로판올, 벤질알코올, 테르피네올(Terpineol) 등 의 알코올류; 아세톤, 메틸에틸케톤, 시클로헥사논, 이소포론, 아세틸아세톤 등의 케톤류; N,N-디메틸포름아미드, N,N-디메틸아세트아미드 등의 아미드류; 테트라히드로푸란, 디옥산, 메틸셀로솔브, 디글림, 부틸카르비톨 등의 에테르류; 아세트산 메틸, 아세트산 에틸, 탄산 디에틸, TXIB(1-이소프로필-2,2-디메틸트리메틸렌디이소부티레이트), 아세트산 카르비톨, 아세트산 부틸카르비톨 등의 에스테르류; 디메틸술폭시드, 술포란 등의 술폭시드 및 술폰류; 염화메틸렌, 클로로포름, 사염화탄소, 1,1,2-트리클로로에탄 등의 지방족 할로겐화 탄화수소; 벤젠, 톨루엔, o-크실렌, p-크실렌, m-크실렌, 모노클로로벤젠, 디클로로벤젠 등의 방향족류 등으로 이루어진 화합물 중에서 적어도 1종 이상 선택되어 사용되는 것이 좋다.Examples of the solvent used for diluting the composition include alcohols such as methanol, ethanol, n-propanol, benzyl alcohol and terpineol; Ketones such as acetone, methyl ethyl ketone, cyclohexanone, isophorone, and acetylacetone; Amides such as N, N-dimethylformamide and N, N-dimethylacetamide; Ethers such as tetrahydrofuran, dioxane, methyl cellosolve, diglyme and butyl carbitol; Esters such as methyl acetate, ethyl acetate, diethyl carbonate, TXIB (1-isopropyl-2,2-dimethyltrimethylene diisobutyrate), acetic acid carbitol and acetic acid butyl carbitol; Sulfoxides and sulfones such as dimethyl sulfoxide and sulfolane; Aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, and 1,1,2-trichloroethane; It is preferable to use at least one compound selected from aromatic compounds such as benzene, toluene, o-xylene, p-xylene, m-xylene, monochlorobenzene and dichlorobenzene.
또한 태양전지 전극 형성용으로 사용되는 경우 본 발명에 따른 도전성 페이스트는 금속 분말, 유리 프릿 및 유기 비히클을 포함하여 이루어진다.Also, when used for forming a solar cell electrode, the conductive paste according to the present invention comprises a metal powder, a glass frit, and an organic vehicle.
상기 금속 분말로는 본 발명의 일실시예에 따라 제조된 은 분말을 사용한다. 금속 분말의 함량은 인쇄 시 형성되는 전극 두께 및 전극의 선저항을 고려할 때 도전성 페이스트 조성물 총 중량을 기준으로 85 내지 95 중량% 포함하는 것이 바람직하다.As the metal powder, silver powder prepared according to one embodiment of the present invention is used. The content of the metal powder is preferably 85 to 95% by weight based on the total weight of the conductive paste composition, taking into account the electrode thickness formed during printing and the line resistance of the electrode.
상기 유리 프릿의 조성이나 입경, 형상에 있어서 특별히 제한을 두지 않는다. 유연 유리 프릿뿐만 아니라 무연 유리 프릿도 사용 가능하다. 바람직하기로는 유리 프릿의 성분 및 함량으로서, 산화물 환산 기준으로 PbO는 5 ~ 29 mol%, TeO2는 20 ~ 34 mol%, Bi2O3는 3 ~ 20 mol%, SiO2 20 mol% 이하, B2O3 10 mol% 이하, 알칼리 금속(Li, Na, K 등) 및 알칼리 토금속(Ca, Mg 등)은 10 ~ 20 mol%를 함유하는 것이 좋다. 상기 각 성분의 유기적 함량 조합에 의해 전극 선폭 증가를 막고 고면저항에서 접촉저항을 우수하게 할 수 있으며, 단략전류 특성을 우수하게 할 수 있다. The composition, particle diameter and shape of the glass frit are not particularly limited. It is possible to use not only flexible glass frit but also lead-free glass frit. Preferably, the content and content of the glass frit are 5 to 29 mol% of PbO, 20 to 34 mol% of TeO 2 , 3 to 20 mol% of Bi 2 O 3 , 20 mol% or less of SiO 2 , 10 mol% or less of B 2 O 3 , 10 to 20 mol% of an alkali metal (Li, Na, K, etc.) and an alkaline earth metal (Ca, Mg, etc.) By combining the organic components of the above components, it is possible to prevent an increase in the line width of the electrode, to improve the contact resistance in the high-surface resistance, and to improve the short-circuit current characteristic.
유리 프릿의 평균 입경은 제한되지 않으나 0.5 내지 10㎛ 범위 내의 입경을 가질 수 있으며, 평균 입경이 다른 다종이 입자를 혼합하여 사용할 수도 있다. 바람직하기로는 적어도 1종의 유리 프릿은 평균 입경(D50)이 2㎛ 이상 10 ㎛ 이하인 것을 사용하는 것이 좋다. 이를 통해 소 성시 반응성이 우수해지고, 특히 고온에서 n층의 데미지를 최소화할 수 있으며 부착력이 개선되고 개방전압(Voc)을 우수하게 할 수 있다. 또한, 소성시 전극의 선폭이 증가하는 것을 감소시킬 수 있다. The average particle diameter of the glass frit is not limited, but it may have a particle diameter in the range of 0.5 to 10 mu m, and a mixture of various particles having different average particle diameters may be used. Preferably, at least one kind of glass frit has an average particle diameter (D50) of not less than 2 mu m and not more than 10 mu m. As a result, the reactivity at the time of firing can be improved, the damage of the n-layer at the high temperature can be minimized, the adhesion can be improved, and the open-circuit voltage (Voc) can be improved. Also, the increase in the line width of the electrode during firing can be reduced.
유리 프릿의 함량은 도전성 페이스트 조성물 총중량을 기준으로 1 내지 5 중량%가 바람직한데, 1 중량% 미만이면 불완전 소성이 이루어져 전기 비저항이 높아질 우려가 있고, 5 중량% 초과하면 은 분말의 소성체 내에 유리 성분이 너무 많아져 전기 비저항이 역시 높아질 우려가 있다.The content of the glass frit is preferably 1 to 5% by weight based on the total weight of the conductive paste composition. If the amount is less than 1% by weight, incomplete firing may occur to increase electrical resistivity. If the amount exceeds 5% by weight, There is a possibility that the electrical resistivity becomes too high due to too much component.
상기 유기 비히클로는 제한되지 않으나 유기 바인더와 용제 등이 포함될 수 있다. 때로는 용제가 생략될 수 있다. 유기 비히클은 제한되지 않으나 도전성 페이스트 조성물 총 중량을 기준으로 1 내지 10 중량%가 바람직하다. The organic vehicle is not limited, but organic binders, solvents, and the like may be included. Solvents may sometimes be omitted. The organic vehicle is not limited, but is preferably 1 to 10% by weight based on the total weight of the conductive paste composition.
유기 비히클은 금속 분말과 유리 프릿 등이 균일하게 혼합된 상태를 유지하는 특성이 요구되며, 예를 들면 스크린 인쇄에 의해 도전성 페이스트가 기재에 도포될 때에, 도전성 페이스트를 균질하게 하여, 인쇄 패턴의 흐려짐 및 흐름을 억제하고, 또한 스크린판으로부터의 도전성 페이스트의 토출성 및 판분리성을 향상시키는 특성이 요구된다. The organic vehicle is required to have a property of keeping the metal powder and the glass frit uniformly mixed. For example, when the conductive paste is applied to the substrate by screen printing, the conductive paste becomes homogeneous, And a property to suppress the flow and to improve the discharging property and the plate separability of the conductive paste from the screen plate.
유기 비히클에 포함되는 유기 바인더는 제한되지 않으나 셀룰로오스 에스테르계 화합물로 셀룰로오스 아세테이트, 셀룰로오스 아세테이트 부틸레이트 등을 예로 들 수 있으며, 셀룰로오스 에테르 화합물로는 에틸 셀룰로오스, 메틸 셀룰로오스, 하이드록시 플로필 셀룰로오스, 하이드록시 에틸 셀룰로오스, 하이드록시 프로필 메틸 셀룰로오스, 하이드록시 에틸 메틸 셀룰로오스 등을 예로 들 수 있으며, 아크릴계 화합물로는 폴리 아크릴아미드, 폴리 메타 아크릴레이트, 폴리 메틸 메타 아크릴레이트, 폴리 에틸 메타 아크릴레이트 등을 예로 들 수 있으며, 비닐계로는 폴리비닐 부티랄, 폴리비닐 아세테이트 그리고 폴리비닐 알코올 등을 예로 들 수 있다. 상기 유기 바인더들은 적어도 1종 이상 선택되어 사용될 수 있다. The organic binder contained in the organic vehicle is not limited, but examples of the cellulose ester compound include cellulose acetate and cellulose acetate butyrate. Examples of the cellulose ether compound include ethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxyethylcellulose Examples of the acrylic compound include polyacrylamide, polymethacrylate, polymethylmethacrylate, and polyethylmethacrylate, and the like. Examples of the acrylic compound include polyacrylamide, polymethacrylate, polymethylmethacrylate, and polyethylmethacrylate And examples of vinyl based ones include polyvinyl butyral, polyvinyl acetate, polyvinyl alcohol, and the like. At least one or more organic binders may be selected and used.
조성물의 희석을 위해 사용되는 용제로서는 알파-터피네올, 텍사놀, 디옥틸 프탈레이트, 디부틸 프탈레이트, 시클로헥산, 헥산, 톨루엔, 벤질알코올, 디옥산, 디에틸렌글리콜, 에틸렌 글리콜 모노 부틸 에테르, 에틸렌 글리콜 모노 부틸 에테르 아세테이트, 디에틸렌 글리콜 모노 부틸 에테르, 디에틸렌 글리콜 모노 부틸 에테르 아세테이트 등으로 이루어진 화합물 중에서 적어도 1종 이상 선택되어 사용되는 것이 좋다.Examples of the solvent used for diluting the composition include alpha-terpineol, texanol, dioctyl phthalate, dibutyl phthalate, cyclohexane, hexane, toluene, benzyl alcohol, dioxane, diethylene glycol, ethylene glycol monobutyl ether, ethylene Glycol monobutyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, and the like.
본 발명에 의한 도전성 페이스트 조성물은 필요에 따라 통상적으로 알려져 있는 첨가제, 예를 들면, 분산제, 가소제, 점도 조정제, 계면활성제, 산화제, 금속 산화물, 금속 유기 화합물 등을 더 포함할 수 있다.The conductive paste composition according to the present invention may further contain additives commonly known in the art, for example, dispersants, plasticizers, viscosity regulators, surfactants, oxidizing agents, metal oxides, metal organic compounds and the like.
본 발명은 또한 상기 도전성 페이스트를 기재 위에 도포하고, 건조 및 소성하는 것을 특징으로 하는 태양전지의 전극 형성 방법 및 상기 방법에 의하여 제조된 태양전지 전극을 제공한다. 본 발명의 태양전지 전극 형성방법에서 상기 특성의 은 분말을 포함하는 도전성 페이스트를 사용하는 것을 제외하고, 기재, 인쇄, 건조 및 소성은 통상적으로 태양전지의 제조에 사용되는 방법들이 사용될 수 있음은 물론이다. 일예로 상기 기재는 실리콘 웨이퍼일 수 있다.The present invention also provides a method of forming an electrode of a solar cell and a solar cell electrode produced by the method, wherein the conductive paste is applied on a substrate, followed by drying and firing. In the method for forming a solar cell electrode of the present invention, the methods used for producing substrates, printing, drying, and firing can be generally those used for manufacturing solar cells, except that conductive pastes containing silver powder having the above- to be. For example, the substrate may be a silicon wafer.
제조예 1 은 분말Production Example 1 was a powder
상온의 순수 660g에 질산은 128g, 암모니아(농도 25%) 157g 및 질산 (농도 60%) 126g 을 넣고 교반하여 용해시켜 제1 수용액을 조제하였다. 한편 상온의 순수 1000g에 하이드로퀴논 20g을 넣고 교반하여 용해시켜 제2 수용액을 조제하였다.To 660 g of pure water at room temperature, 128 g of silver nitrate, 157 g of ammonia (concentration 25%) and 126 g of nitric acid (concentration 60%) were added and dissolved by stirring to prepare a first aqueous solution. Meanwhile, 20 g of hydroquinone was added to 1000 g of pure water at room temperature and dissolved by stirring to prepare a second aqueous solution.
이어서, 제1 수용액을 교반한 상태로 하고, 이 제1 수용액에 제2 수용액을 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 세척하여 약 40g의 은 분말을 얻었다. Subsequently, the first aqueous solution was stirred, and the second aqueous solution was added all at once to the first aqueous solution, and the mixture was further stirred for 5 minutes from the completion of the addition to grow particles in the mixed solution. Thereafter, the stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded, the mixed solution was filtered using a centrifugal separator, and the filter material was washed with pure water to obtain about 40 g of silver powder.
실시예 및 비교예Examples and Comparative Examples
(1) 실시예 1 내지 16(1) Examples 1 to 16
DMW(De-Mineralized Water) 2L와 상기 제조예에서 제조된 은 분말 500g을 넣은 후, Homo-mixer(K&S company, Lab용)를 이용하여 3300rpm에 20분간 은 분말을 분산시켜 은 분말이 분산된 용액을 제조하였다. 상기 은 분말이 분산된 용액에 알칼리 금속 수소화붕소 수용액을 투입하고 5분간 더 교반한 뒤, 원심분리기를 이용하여 여과하고 여재를 순수로 세정하여 전기전도도를 50㎲ 이하가 되게 하였다. 2 L of De-Mineralized Water (DMW) and 500 g of the silver powder prepared in the above-mentioned Production Example were put in a ball mill and dispersed in powder at 3300 rpm for 20 minutes using a homo-mixer (K & S company, Lab) . The alkali metal borohydride aqueous solution was added to the silver powder-dispersed solution and further stirred for 5 minutes. Then, the mixture was filtered using a centrifugal separator, and the filter material was washed with pure water so that the electric conductivity was 50 μs or less.
상기 알칼리 금속 수소화붕소 수용액의 종류 및 사용량을 하기 표 1에 나타내었으며, 사용량은 세척되는 은 분말 중량에 대한 알칼리 금속 수소화붕소의 중량%로 나타내었다. 세척 용액의 온도는 별도로 기재한 예시를 제외하고는 상온을 의미한다. The type and amount of the alkali metal borohydride aqueous solution are shown in Table 1 below, and the amount of alkali metal borohydride was expressed in terms of weight% of the alkali metal borohydride with respect to the weight of silver powder to be cleaned. The temperature of the cleaning solution means room temperature except for the examples described separately.
(2) 비교예 1 및 2(2) Comparative Examples 1 and 2
은 분말의 3배에 해당하는 양의 순수를 50℃로 가열하고, 가열한 순수에 NaOH(은 분말의 1중량% 및 10중량%)를 넣고 호모믹서(K&S company, Lab용)를 3300 rpm으로 5분 교반하여 NaOH를 용해시켰다. 여기에, 상기 제조예에서 제조된 은 분말 500g을 넣고 20분간 교반한 뒤 교반을 멈추고 혼합액을 원심분리기를 이용하여 여과하고, 여재를 순수로 세정하여 전기전도도를 50㎲ 이하가 되게 하였다. NaOH (1 wt.% And 10 wt.% Of the silver powder) was added to the pure water heated at 50 DEG C and the homomixer (for K & S company, Lab) was mixed at 3300 rpm The mixture was stirred for 5 minutes to dissolve NaOH. 500 g of the silver powder prepared in the above Preparation Example was added and stirred for 20 minutes. Stirring was stopped, the mixture was filtered using a centrifugal separator, and the filter material was washed with pure water so that the electric conductivity was 50 μs or less.
상기 NaOH의 사용량을 하기 표 1에 나타내었으며, 사용량은 세척되는 은 분말 중량에 대한 NaOH의 중량%로 나타내었다. The amount of NaOH to be used is shown in Table 1 below, and the amount of NaOH to be used is represented by the weight percentage of NaOH to the weight of silver powder to be washed.
(3) 비교예 3 (3) Comparative Example 3
2L의 상온의 순수에 NaOH(은 분말의 10중량%)를 넣고 호모믹서(K&S company, Lab용)를 3300 rpm으로 5분 교반하여 NaOH를 용해시켰다. 여기에, 상기 제조예에서 제조된 은 분말 500g을 넣고 20분간 교반한 뒤 교반을 멈추고 혼합액을 원심분리기를 이용하여 여과하고, 여재를 순수로 세정하여 전기전도도를 50㎲ 이하가 되게 하였다. NaOH (10% by weight of silver powder) was added to 2 L of pure water at room temperature, and NaOH was dissolved by homomixer (K & S company, Lab) for 5 minutes with stirring at 3300 rpm. 500 g of the silver powder prepared in the above Preparation Example was added and stirred for 20 minutes. Stirring was stopped, the mixture was filtered using a centrifugal separator, and the filter material was washed with pure water so that the electric conductivity was 50 μs or less.
(4) 비교예 4 내지 5 (4) Comparative Examples 4 to 5
순수 2L와 상기 제조예에서 제조된 은 분말 500g을 넣은 후, Homo-mixer(K&S company, Lab용)를 이용하여 3300rpm에 20분간 은 분말을 분산시켜 은 분말이 분산된 용액을 제조하였다. 상기 은 분말이 분산된 용액에 알칼리 금속 수소화붕소 수용액을 투입하고 5분간 더 교반한 뒤, 원심분리기를 이용하여 여과하고 여재를 순수로 세정하여 전기전도도를 50㎲ 이하가 되게 하였다. 2 L of pure water and 500 g of the silver powder prepared in the above production example were put into a homo-mixer (K & S company, Lab) for dispersing silver powder at 3300 rpm for 20 minutes to prepare a silver powder-dispersed solution. The alkali metal borohydride aqueous solution was added to the silver powder-dispersed solution and further stirred for 5 minutes. Then, the mixture was filtered using a centrifugal separator, and the filter material was washed with pure water so that the electric conductivity was 50 μs or less.
상기 알칼리 금속 수소화붕소 수용액의 종류 및 사용량을 하기 표 1에 나타내었으며, 사용량은 세척되는 은 분말 중량에 대한 알칼리 금속 수소화붕소의 중량%로 나타내었다. 세척 용액의 온도는 별도로 기재한 예시를 제외하고는 상온을 의미한다. The type and amount of the alkali metal borohydride aqueous solution are shown in Table 1 below, and the amount of alkali metal borohydride was expressed in terms of weight% of the alkali metal borohydride with respect to the weight of silver powder to be cleaned. The temperature of the cleaning solution means room temperature except for the examples described separately.
종류Kinds 함량(wt%)Content (wt%)
MM xx R1 R 1 R2 R 2 R3 R 3 R4 R 4 yy
실시예 1Example 1 NaNa 1One HH HH HH HH 1One 1.01.0
실시예 2Example 2 NaNa 1One HH HH HH HH 1One 0.50.5
실시예 3Example 3 NaNa 1One HH HH HH HH 1One 0.20.2
실시예 4Example 4 NaNa 1One HH HH HH HH 1One 0.10.1
실시예 5Example 5 NaNa 1One HH HH HH HH 1One 1.51.5
실시예 6Example 6 NaNa 1One HH HH HH HH 1One 2.02.0
실시예 7Example 7 LiLi 1One HH HH HH HH 1One 1.01.0
실시예 8Example 8 KK 1One HH HH HH HH 1One 1.01.0
실시예 9Example 9 LiLi 1One HH C2H5 C 2 H 5 C2H5 C 2 H 5 C2H5 C 2 H 5 1One 1.21.2
실시예 10Example 10 NaNa 22 HH BH3 BH 3 HH HH 1One 1.01.0
실시예 11Example 11 NaNa 22 HH B3H7 B 3 H 7 HH HH 1One 0.70.7
실시예 12Example 12 LiLi 1One HH OCH3 OCH 3 HH HH 1One 1.01.0
실시예 13Example 13 KK 1One HH NH2 NH 2 HH HH 1One 1.01.0
실시예 14Example 14 NaNa 1One HH OHOH HH OHOH 1One 0.50.5
실시예 15Example 15 NaNa 1One HH CH2OHCH 2 OH HH HH 1One 0.70.7
실시예 16Example 16 LiLi 1One HH COOHCOOH HH HH 1One 1.01.0
실시예 17Example 17 KK 1One HH SHSH HH HH 1One 1.21.2
비교예 1Comparative Example 1 50℃ NaOH50 C NaOH 1One
비교예 2Comparative Example 2 50℃ NaOH50 C NaOH 1010
비교예 3Comparative Example 3 NaOHNaOH 1010
비교예 4Comparative Example 4 NaNa 1One HH HH HH HH 1One 0.050.05
비교예 5Comparative Example 5 NaNa 1One HH HH HH HH 1One 2.52.5
실험예 1Experimental Example 1
(1) 은 분말의 물성 측정(1) is a measurement of the physical properties of the powder
제조된 은 분말의 응집도를 평가하기 위하여 SEM size(DSEM, μm) 에 대한 PSA size(D50, μm)의 비를 측정하였다. 광산란에 의하여 다분산된 입자를 하나의 입자로 입도 분석이 이루어지는 PSA 입자 크기가 각각의 입자의 지름을 SEM 촬영을 통해 측정한 입자 크기와 차이가 적을수록 분산이 잘 된 것을 의미한다.The ratio of PSA size (D 50 , μm) to SEM size (D SEM , μm) was measured to evaluate the cohesion of the silver powder. It means that PSA particle size, which is the particle size analysis of the polydispersed particles as a single particle by light scattering, is better dispersed as the particle size measured by SEM photograph is smaller.
실시예 및 비교예에 의해 세척이 완료된 은 분말 100개 각각의 지름 크기를 측정한 후 평균을 내어 SEM size 를 측정하였다. SEM size was measured by measuring the diameter of each of 100 washed silver powders according to Examples and Comparative Examples and then averaging them.
또한 실시예 및 비교예에 의해 제조된 은 분말 0.03g을 에탄올 30ml에 투입 후, 초음파 1분 하여 에탄올에 은 분말을 분산시킨 후 입도 분석 장비에 투입하여 PSA size를 측정하였다. 입경의 누적분포도에서, 그래프의 전체 넓이를 기준으로 가장 큰 입경으로부터 넓이가 50%인 입경을 D50으로 표현한다.In addition, 0.03 g of the silver powder prepared by the examples and the comparative examples was put into 30 ml of ethanol, and the silver powder was dispersed in ethanol for 1 minute by ultrasonication, and the powder was put into a particle size analyzer to measure the PSA size. In the cumulative distribution chart of the particle diameter, the particle diameter at which the width is 50% from the largest particle diameter is expressed as D 50 based on the entire width of the graph.
(2) 세척 효율 측정(2) Measurement of cleaning efficiency
세척 후 은 분말 표면에 잔존하는 유기물의 양을 Hot-NaOH 수용액 평가를 통해 분석하여 세척 효율을 측정하였다. 즉, Hot-NaOH 수용액을 이용하여 은 분말 표면에 잔존하는 유기물을 용해시킨 후, 상등액의 색도를 측정하여 잔존 유기물의 농도를 수치화하였다. 상등액의 색도가 진할수록 잔존 유기물의 농도가 높다는 것을 의미, 즉 세척이 잘 안되었다는 것을 의미한다. Hot-NaOH 수용액 평가 방법은 하기와 같다. After washing, the amount of organic matter remaining on the surface of the powder was analyzed by Hot-NaOH aqueous solution evaluation to measure the cleaning efficiency. That is, after the organic matter remaining on the surface of the silver powder was dissolved using a hot-NaOH aqueous solution, the chromaticity of the supernatant was measured to quantify the concentration of the remaining organic matter. The higher the chromaticity of the supernatant, the higher the concentration of the remaining organic matter, which means that the washing is not good. The evaluation method of the hot-NaOH aqueous solution is as follows.
세척 공정이 완료된 은 분말을 30g(수분의 무게를 제외한 은 분말의 중량) 과 NaOH 0.1mol/L 수용액 30g을 50ml vial에 각각 계량한 뒤 60℃의 water bath에 20분간 Dipping(5분마다 hand shaking) 하고 도 1에 나타낸 것과 같이 상등액 색이 나올때까지(약 20~30분) 상온에 방치하였다. 상등액을 따로 따라 내어 유체 색도계를 사용하여 색도값(PCU, Platinum Cobalt Units)을 측정하였다. Weigh 30 g of silver powder (weight of silver powder excluding the weight of water) and 30 g of aqueous solution of 0.1 mol / L NaOH in 50 ml vials after each washing process, and then dipping in a water bath at 60 ° C for 20 minutes (hand shaking every 5 minutes ) And allowed to stand at room temperature until the color of the supernatant appeared (about 20 to 30 minutes) as shown in Fig. The supernatant was taken separately and chromaticity values (PCU, Platinum Cobalt Units) were measured using a fluid colorimeter.
색도값의 수치가 높을 수록 상등액의 색도가 진한 것을 의미하고, 세척공정에서 세척되지 않은 유기물이 용해되어 나와 상등액 색상이 진해지기 때문에 색도값이 클수록 세척이 잘 되지 않은 것을 의미한다. The higher the value of the chromaticity value, the higher the chromaticity of the supernatant. The higher the chromaticity value is, the more difficult the washing is because the uncoloured organic matter is dissolved in the washing process and the supernatant color becomes darker.
(3) 알칼리 함량(3) Alkali content
고체 분말 약 3g을 액상으로 전처리 후, Agilent ICP-OES(720-ES)를 사용하여 알칼리 이온들의 성분 함량을 측정하였다. About 3 g of the solid powder was pretreated with the liquid phase, and the content of alkaline ions was measured using Agilent ICP-OES (720-ES).
(4) 발수성 평가(4) Water repellency evaluation
상기 세척 공정이 완료된 은 분말을 DMW에 넣고 분산 시킨 후, 암모늄스테아레이트(ammonium stearate)의 에탄올 용액을 첨가하여 4000 rpm으로 20분간 교반하여 표면처리하였다. 이후 80℃에서 12시간 동안 열풍 건조하고 Jetmill을 통해 해쇄하여 표면처리된 은 분말을 얻었다. The cleaned silver powder was placed in DMW and dispersed. Then, an ammonium stearate ethanol solution was added thereto, and the mixture was stirred at 4000 rpm for 20 minutes. After that, hot air drying was performed at 80 ° C for 12 hours, and the powder was surface-treated by jet milling to obtain silver powder.
50ml vial에 상기 표면처리된 은 분말 1g(수분의 무게를 제외한 은 분말의 중량), DMW 20g을 계량하여 투입하였다. Vial을 vortex mixer(Vortex-Genie 2 Mixer, scientific industries)를 사용하여 1분간 분산시켰다. 30초 간 방치 후, 물에 대한 은 분말의 분산 상태를 판단하였다. 도 2에 나타나는 것과 같이 발수성 정도를 1 내지 5로 평가하였다. 은 분말이 분산된 물 부분의 농도가 높으면 발수성이 떨어지는 것을 의미한다.1 g of the surface-treated silver powder (weight of silver powder except for the weight of water) and 20 g of DMW were weighed into a 50 ml vial. The vials were dispersed for 1 minute using a vortex mixer (Vortex-Genie 2 Mixer, scientific industries). After being left for 30 seconds, the dispersion state of silver powder to water was determined. The degree of water repellency was evaluated as 1 to 5 as shown in Fig. Means that the water repellency is deteriorated when the concentration of the water portion in which the powder is dispersed is high.
세척이 잘된 경우 은 분말 표면에 잔존하는 유기물 함량이 감소하기 때문에 세척 후 표면처리 공정에서 표면처리제가 은 분말 표면에 잘 흡착하게 된다. 은 분말의 물에 대한 반발력(발수성) 측정을 통해 표면처리 균일성을 판단하였고 이를 통해 세척의 효과가 우수함을 간접적으로 알 수 있다. In the case of good washing, the amount of organic matter remaining on the powder surface is reduced, so that the surface treating agent is adsorbed well on the powder surface in the surface treatment process after washing. The water repellency (water repellency) of the silver powder was measured to determine the uniformity of the surface treatment, and it is indirectly known that the cleaning effect is excellent.
응집도(D50/DSEM)Cohesion (D 50 / D SEM ) 상등액 색도(PCU)The supernatant color (PCU) Alkali 함량(ppm)Alkali content (ppm) 발수성(1~5)Water repellency (1 ~ 5)
실시예1Example 1 1.721.72 7070 2929 55
실시예2Example 2 1.741.74 8080 2424 55
실시예3Example 3 1.751.75 110110 3737 44
실시예 4Example 4 1.731.73 220220 2222 33
실시예 5Example 5 1.761.76 120120 2525 44
실시예 6Example 6 1.761.76 6060 3535 55
실시예 7Example 7 1.791.79 8080 4040 44
실시예 8Example 8 1.771.77 9090 3434 55
실시예 9Example 9 1.761.76 100100 5252 44
실시예 10Example 10 1.751.75 110110 5555 44
실시예 11Example 11 1.731.73 180180 5757 55
실시예 12Example 12 1.781.78 9090 3838 55
실시예 13Example 13 1.751.75 170170 5454 33
실시예 14Example 14 1.761.76 150150 5151 44
실시예 15Example 15 1.791.79 100100 4848 44
실시예 16Example 16 1.771.77 120120 5050 44
비교예 1Comparative Example 1 1.811.81 >500> 500 7575 1One
비교예 2Comparative Example 2 1.861.86 210210 120120 33
비교예 3Comparative Example 3 1.821.82 480480 6262 22
비교예 4Comparative Example 4 1.831.83 >500> 500 3232 1One
비교예 5Comparative Example 5 1.781.78 9090 7878 44
상기 표 2에 나타나는 것과 같이 실시예에 따라 세척한 은 분말의 응집도가 1.80 이하, 상등액의 색도가 200PCU 이하, 알칼리 함량이 80ppm 이하로 비교예에 비하여 낮고, 특히 실시예 1 내지 3에 따라 세척한 은 분말의 물성이 가장 우수한 것을 알 수 있다.As shown in Table 2, the agglomeration degree of the silver powder washed according to the example was lower than 1.80, the chromaticity of the supernatant was lower than 200PCU, and the alkali content was lower than 80 ppm, which was lower than that of the comparative example. It can be seen that the physical properties of the silver powder are the most excellent.
비교예 1 내지 3의 경우 많은 양의 알칼리 수용액을 사용하여야 하기 때문에 알칼리 함량이 매우 증가하여 이로 인하여 도전성 페이스트의 전기적 특성을 저하시킬 것으로 판단된다.In Comparative Examples 1 to 3, since a large amount of alkaline aqueous solution should be used, it is considered that the alkaline content is greatly increased, thereby lowering the electrical characteristics of the conductive paste.
비교예 2는 비교예 3과 비교하였을 때 세척 액의 온도 상승으로 인해 세척 효율이 증가하여 발수성은 좋아지지만 응집이 증가하는 문제점이 있는 것을 알 수 있다.Compared with Comparative Example 3, Comparative Example 2 shows an increase in washing efficiency due to a rise in the temperature of the washing liquid, thereby improving water repellency but increasing coagulation.
비교예 4의 경우 세척 액의 사용량이 적어 알칼리 함량이 낮지만 세척이 잘 이루어지지 않아 응집이 발생하고, 상등액의 색도가 매우 높은 것으로 비추어보아 유기물 함량이 높을 것으로 판단된다. In the case of Comparative Example 4, the amount of the washing solution was low and the alkaline content was low. However, since the washing was not performed well, aggregation occurred and the color of the supernatant was very high.
비교예 5의 경우 세척 액의 사용량을 증가시키더라도 그 세척 효율이 크게 증가하지 않았으며, 세척 액의 사용량 증가로 인하여 알칼리 함량이 높은 것을 알 수 있으며 이로 인하여 도전성 페이스트의 전기적 특성을 저하시킬 것으로 판단된다.In Comparative Example 5, even if the amount of the cleaning solution used was increased, the cleaning efficiency was not greatly increased, and it was found that the alkali content was high due to an increase in the amount of the cleaning solution used, which would lower the electrical characteristics of the conductive paste do.
제조예 2 도전성 페이스트Production Example 2 [
상기 실시예 및 비교예에 따라 세척된 은 분말 89.5 중량%, 유리 프릿 1.92 중량%, 유기 비히클 5.20 중량%, 첨가제 3.38 중량%를 자전공전식 진공 교반 탈포 장치로 혼합한 후 삼본롤을 사용함으로써, 도전성 페이스트를 얻었다.According to the examples and the comparative examples, by using a revolving vacuum type stirring and defoaming device, 89.5% by weight of washed silver powder, 1.92% by weight of glass frit, 5.20% by weight of organic vehicle and 3.38% A paste was obtained.
실험예 2Experimental Example 2
상기 제조예 2에 따라 얻어진 도전성 페이스트를 알루미나 판에 40㎛ 메쉬의 스크린 프린팅 기법으로 패턴인쇄 하고 건조로를 사용하여 약 300℃에서 25초간 건조한 후 소성로를 사용하여 800℃에서 25초간 소성하여 전극 샘플을 형성하였다. 상기 전극 샘플의 직렬저항(Rs)을 측정하여 하기 표 3에 나타내었다. The conductive paste obtained in Preparation Example 2 was pattern printed on an alumina plate with a screen printing technique of 40 μm mesh, dried at about 300 ° C. for 25 seconds using a drying furnace, and then fired at 800 ° C. for 25 seconds using a firing furnace, . The series resistance (Rs) of the electrode sample was measured and is shown in Table 3 below.
Rs(Ω)Rs (Ω)
실시예1Example 1 0.001270.00127
실시예2Example 2 0.001200.00120
실시예3Example 3 0.001290.00129
실시예 4Example 4 0.001250.00125
실시예 5Example 5 0.001310.00131
실시예 6Example 6 0.001290.00129
실시예 7Example 7 0.001340.00134
실시예 8Example 8 0.001380.00138
실시예 9Example 9 0.001290.00129
실시예 10Example 10 0.001350.00135
실시예 11Example 11 0.001320.00132
실시예 12Example 12 0.001370.00137
실시예 13Example 13 0.001280.00128
실시예 14Example 14 0.001330.00133
실시예 15Example 15 0.001400.00140
실시예 16Example 16 0.001340.00134
비교예 1Comparative Example 1 0.001450.00145
비교예 2Comparative Example 2 0.001870.00187
비교예 3Comparative Example 3 0.001490.00149
비교예 4Comparative Example 4 0.001660.00166
비교예 5Comparative Example 5 0.001690.00169
상기 표 3에 나타나는 것과 같이 실시예에 따라 세척한 은 분말을 포함하는 도전성 페이스트로 형성한 전극의 직렬저항이 0.00140Ω 이하로 비교예에 비하여 낮고, 특히 실시예 1 내지 3에 따라 세척한 은 분말을 사용한 경우 전기 전도성이 가장 우수한 것을 알 수 있다. 비교예의 경우 앞서 알칼리 함량을 통해 예상했던 것과 같이 전기적 특성이 저하되는 것을 알 수 있다. As shown in Table 3, the series resistance of the electrode formed of the conductive paste containing the silver powder washed according to the example was 0.00140? Or less, which is lower than that of the comparative example. In particular, the silver powder washed according to Examples 1 to 3 The best electrical conductivity is obtained. In the case of the comparative example, it can be seen that the electrical properties are degraded as expected through the alkali content.
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.The features, structures, effects, and the like illustrated in the above-described embodiments can be combined and modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

Claims (9)

  1. 환원제를 이용하여 습식환원 방법에 의하여 석출된 은 분말을 하기 화학식 1로 표현되는 화합물을 포함하는 세척 용액을 이용하여 세척하는 세척단계(S31)를 포함하는 은 분말의 세척방법.And a cleaning step (S31) of washing the silver powder precipitated by the wet reduction method using a reducing agent with a cleaning solution containing a compound represented by the following formula (1).
    [화학식 1][Chemical Formula 1]
    Figure PCTKR2018012185-appb-I000003
    Figure PCTKR2018012185-appb-I000003
    (이 때, M은 Li, Na 또는 K을 포함하며,(Wherein M comprises Li, Na or K,
    x, y는 각각 독립적으로 1 또는 2이고,x and y are each independently 1 or 2,
    R1, R2, R3 및 R4는 각각 독립적으로 수소(H), C1-C6 알킬(alkyl), C1-C6 알콕시(alkoxy), 보란(boranes), 아미노(amino), 히드록시(hydroxy), 히드록시메틸(hydroxymethyl), 카르복시(carboxy) 또는 메르캅토(mercapto)을 포함한다.)R 1 , R 2 , R 3 and R 4 are each independently selected from the group consisting of hydrogen (H), C 1 -C 6 alkyl, C 1 -C 6 alkoxy, boranes, amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.) The term "
  2. 제1항에 있어서,The method according to claim 1,
    상기 세척단계(S31)는 상기 은 분말 100 중량부에 대하여 상기 화합물이 0.1 내지 2.0 중량부로 사용되도록 세척하는 단계인 은 분말의 세척방법.Wherein the washing step S31 is a step of washing the silver powder so that the compound is used in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the silver powder.
  3. 제1항에 있어서,The method according to claim 1,
    상기 세척단계(S31)는 상기 화학식 1로 표현되는 화합물 중 M이 Na 또는 Li를 포함하고, x는 1 또는 2이며, y는 1이고, R1, R2, R3 및 R4는 각각 독립적으로 수소(H), C1-C6 알킬(alkyl), 또는 보란(boranes)을 포함하는 화합물을 포함하는 세척 용액을 이용하여 세척하는 것을 특징으로 하는 은 분말의 세척방법.In the washing step S31, M is Na or Li, x is 1 or 2, y is 1, and R 1 , R 2 , R 3 and R 4 are each independently Characterized in that the cleaning is carried out using a cleaning solution comprising a compound comprising hydrogen (H), C 1 -C 6 alkyl, or boranes.
  4. 제1항에 있어서,The method according to claim 1,
    상기 환원제는 아스코르브산, 알칸올아민, 하이드로퀴논, 히드라진 및 포르말린으로 이루어지는 군으로부터 선택되는 1종 이상을 포함하는 것을 특징으로 하는 은 분말의 세척방법.Wherein the reducing agent comprises at least one selected from the group consisting of ascorbic acid, alkanolamine, hydroquinone, hydrazine and formalin.
  5. 제1항에 있어서,The method according to claim 1,
    상기 세척단계(S31)는 용제에 상기 석출된 은 분말을 분산시키고, 상기 은 분말이 분산된 용액에 상기 세척 용액을 넣고 혼합 교반하는 단계인 것을 특징으로 하는 은 분말의 세척방법.Wherein the cleaning step S31 is a step of dispersing the precipitated silver powder in a solvent and adding the cleaning solution to a solution in which the silver powder is dispersed and mixing and stirring.
  6. 은 이온, 암모니아(NH3) 및 질산(HNO3)을 포함하는 제1 반응액 및 환원제를 포함하는 제2 반응액을 제조하는 반응액제조단계(S21) 및 제1 반응액 및 제2 반응액을 반응시켜 은 분말을 얻는 석출단계(S22)를 포함하는 은 염 환원단계(S2); 및Silver ions, ammonia (NH 3) and nitric first reaction solution and for producing a second reaction solution containing a reducing agent in the reaction mixture prepared step (S21) and the first reaction solution containing the (HNO 3) and a second reaction mixture A silver salt reducing step (S2) including a precipitation step (S22) for obtaining a silver powder by reacting the silver powder; And
    상기 얻어진 은 분말을 하기 화학식 1로 표현되는 화합물을 포함하는 세척 용액을 이용하여 세척하는 세척단계(S31);를 포함하는 은 분말 제조방법.(S31) washing the obtained silver powder with a washing solution containing a compound represented by the following formula (1).
    [화학식 1][Chemical Formula 1]
    Figure PCTKR2018012185-appb-I000004
    Figure PCTKR2018012185-appb-I000004
    (이 때, M은 Li, Na 또는 K을 포함하며,(Wherein M comprises Li, Na or K,
    x, y는 각각 독립적으로 1 또는 2이고,x and y are each independently 1 or 2,
    R1, R2, R3 및 R4는 각각 독립적으로 수소(H), C1-C6 알킬(alkyl), C1-C6 알콕시(alkoxy), 보란(boranes), 아미노(amino), 히드록시(hydroxy), 히드록시메틸(hydroxymethyl), 카르복시(carboxy) 또는 메르캅토(mercapto)을 포함한다.)R 1 , R 2 , R 3 and R 4 are each independently selected from the group consisting of hydrogen (H), C 1 -C 6 alkyl, C 1 -C 6 alkoxy, boranes, amino, Include hydroxy, hydroxymethyl, carboxy or mercapto.) The term "
  7. 제1항의 방법에 따라 세척된 은 분말로서,A silver powder washed according to the method of claim 1,
    응집도(D50/DSEM)가 1.80 이하이고, NaOH 용액에 용해시킨 상등액의 색도가 200PCU 이하이며, 알칼리 함량이 80ppm 이하인 은 분말. A silver powder having a cohesion (D 50 / D SEM ) of 1.80 or less, a chromaticity of a supernatant dissolved in an NaOH solution of 200 PCU or less, and an alkali content of 80 ppm or less.
  8. 제1항의 방법에 따라 세척된 은 분말을 포함하는 금속 분말; 및A metal powder comprising silver powder washed according to the method of claim 1; And
    용제 및 유기 바인더를 포함하는 유리 비히클; 을 포함하는 도전성 페이스트.A glass vehicle comprising a solvent and an organic binder; ≪ / RTI >
  9. 제1항의 방법에 따라 세척된 은 분말을 포함하는 금속 분말;A metal powder comprising silver powder washed according to the method of claim 1;
    유리 프릿; 및Glass frit; And
    용제 및 유기 바인더를 포함하는 유기 비히클;을 포함하는 태양전지 전극용 도전성 페이스트.1. A conductive paste for a solar cell electrode, comprising an organic vehicle comprising a solvent and an organic binder.
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008297589A (en) * 2007-05-30 2008-12-11 Mitsubishi Materials Corp Method for producing clean silver microparticle
JP2011181538A (en) * 2010-02-26 2011-09-15 Kyoto Elex Kk Conductive paste for forming electrode of solar cell element
KR101157478B1 (en) * 2011-04-28 2012-06-20 에이엠씨주식회사 Silver paste for solar cell electrode and the method thereof
KR20170019727A (en) * 2015-08-12 2017-02-22 엘에스니꼬동제련 주식회사 The manufacturing method of silver powder for high temperature sintering conductive paste
KR20170030929A (en) * 2015-09-10 2017-03-20 엘에스니꼬동제련 주식회사 The manufacturing method of silver
KR20170035578A (en) * 2015-09-23 2017-03-31 엘에스니꼬동제련 주식회사 The manufacturing method of silver powder

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI285568B (en) 2005-02-02 2007-08-21 Dowa Mining Co Powder of silver particles and process
KR101277923B1 (en) 2011-08-29 2013-06-26 현대제철 주식회사 An apparatus for preventing deformation from strip coil

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008297589A (en) * 2007-05-30 2008-12-11 Mitsubishi Materials Corp Method for producing clean silver microparticle
JP2011181538A (en) * 2010-02-26 2011-09-15 Kyoto Elex Kk Conductive paste for forming electrode of solar cell element
KR101157478B1 (en) * 2011-04-28 2012-06-20 에이엠씨주식회사 Silver paste for solar cell electrode and the method thereof
KR20170019727A (en) * 2015-08-12 2017-02-22 엘에스니꼬동제련 주식회사 The manufacturing method of silver powder for high temperature sintering conductive paste
KR20170030929A (en) * 2015-09-10 2017-03-20 엘에스니꼬동제련 주식회사 The manufacturing method of silver
KR20170035578A (en) * 2015-09-23 2017-03-31 엘에스니꼬동제련 주식회사 The manufacturing method of silver powder

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