KR20190048140A - Surface-treated silver powder and method for producing the same - Google Patents

Abstract

The present invention relates to a surface treatment method for silver powder and a manufacturing method for surface-treated silver powder. Silver powder is surface-treated using higher fatty amine and has excellent sintered density in a case of being sintered at high temperature of 700°C.

Description

Surface-treated silver powder and method for producing same [0002]

The present invention relates to a surface-treated silver powder and a method for producing the same, and more particularly to a silver powder suitable for use in a conductive paste for forming an electrode in an electronic component such as an electrode for a solar cell or an internal electrode of a multilayer capacitor, And a manufacturing method thereof.

The conductive metal paste is a paste in which a conductive film (film) is formed and a conductive paste (metal filler) is dispersed in a vehicle composed of a resin binder and a solvent. And the like.

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. BACKGROUND ART [0002] The use of silver paste has been widely used for STH (Silver Through Hole), adhesive, or coating materials in electronic parts, such as PCBs (Printed Circuit Boards), where reliability is particularly important.

The conductive metal paste currently in practical use has a resin curing type in which the conductive filler is squeezed by curing of the resin at a temperature as low as 200 DEG C or less to ensure conduction and an organic vehicle component is volatilized in a high temperature atmosphere of 500 to 1200 DEG C There is a sintered die in which the conductive filler is sintered to ensure conduction.

Among them, the sintered conductive paste is composed of a conductive filler mainly composed of a noble metal, a glass frit, and an organic vehicle (resin and organic solvent). After the coated film is dried and treated at a high temperature, the organic vehicle component And the sintered coating film is fused between the metal fillers to develop conductivity.

When the metal powder is sintered at a high temperature, internal pores are essentially formed due to the decomposition of pores or organic substances present in the conductive paste, so that the sintered density of the metal powder is determined by theoretical density of the metal As the sintered density of the metal powder is lowered, the electrical conductivity of the coated film formed using the conductive paste is also lowered.

In the prior art, a coating powder is coated on the outer surface of a metal powder to form a filler so that the coating has a low specific gravity to increase the coating film density to increase the light conversion efficiency (Patent Document 1) (Patent Document 2). However, the conventional techniques have a problem in that the number of processes increases and the cost increases.

1. Korean Registered Patent No. 10-1315105 (2013.09.30) 2. Korean Patent No. 10-1188486 (September 27, 2012)

In order to solve the above problems, the present invention provides a silver powder having a high sintered density, a method for producing the silver powder, and a conductive paste containing the silver powder. Another object of the present invention is to improve the conversion efficiency of the solar cell by forming the front electrode using the conductive paste.

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.

The present invention relates to a silver powder (1) comprising a second surface treatment step (S42) of surface treating a silver powder treated first with silver powder or a first treatment agent using a second treatment agent comprising a fatty amine A surface treatment method of the present invention.

The fatty amine is also characterized in that it contains an alkylamine having 6 to 24 carbon atoms.

Also, the alkylamine may be at least one selected from the group consisting of triethylamine, heptylamine, octadecylamine, hexadecylamine, decylamine, octylamine, didecylamine, Or trioctylamine. ≪ Desc / Clms Page number 2 >

The second surface treatment step (S42) is a step including adding silver powder treated first with silver powder or a first treatment agent to the second treatment agent, and then stirring the silver powder for 10 to 30 minutes . The second surface treatment step (S42) is a step of mixing 0.1 to 1.0 part by weight of the high-grade amine with respect to 100 parts by weight of the silver powder that has been primary treated using the silver powder or the first treatment agent .

Also, the second surface treatment step (S42) is a step of adding silver powder, which has been primary treated with the silver powder or the first treatment agent, to an alcohol solution containing the fatty amine and stirring the silver powder, the alcohol solution containing fatty amine is a solution in which the higher amine is dissolved in an amount of 10 to 15 wt% based on the total weight of the solution.

Also, the silver powder treated first using the first treatment agent is a silver powder treated through a first surface treatment step (S41) in which silver powder and a first treatment agent are added to a solvent and mixed and stirred.

The first treatment agent may be at least one selected from the group consisting of alkyl sulfates, ethoxylated alkyl sulfates, alkyl glyceryl ether sulfonates, alkyl ethoxy ether sulfonates, But are not limited to, acyl methyl taurate, fatty acyl glycinate, alkyl ethoxy carboxylate, acyl glutamate, acyl isethionate, But are not limited to, alkyl sulfosuccinates, alkyl ethoxy sulfosuccinates, alkyl phosphate esters, acyl carcosinates, acyl aspartates, alkoxyacyl amides, An alkoxy acyl amide carboxylate, acyl ethylene diamine triacetate, When characterized by comprising the ethyl isethionate (acyl isethionate hydroxyethyl), and mixtures thereof.

Also, the first surface treatment step (S41) is a step of using 300 to 500 parts by weight of the solvent and 0.1 to 1.0 parts by weight of the first treatment agent with respect to 100 parts by weight of the silver powder.

In addition, the first surface treatment step (S41) is characterized in that silver powder is added to the solvent, and the first treatment agent is added, followed by stirring at 2000 to 4000 rpm for 10 to 30 minutes.

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; A second surface treatment step (S42) of surface-treating the obtained silver powder or the obtained silver powder by using a second treatment agent containing a fatty amine, which is a primary treatment of the obtained silver powder with a first treatment agent, The present invention also provides a method of producing silver powder for producing a surface-treated silver powder.

The silver powder subjected to the primary treatment using the first treatment agent is a silver powder treated through a first surface treatment step (S41) in which the obtained silver powder and the first treatment agent are mixed and stirred in a solvent .

Also, the present invention is a silver powder having an average particle size (D50) of 1.6 to 2.0 μm, wherein the silver powder is a silver powder surface-treated with a treatment agent containing a fatty amine.

The present invention also relates to a metal powder including the silver powder for the conductive paste; And a glass vehicle comprising a solvent and an organic binder; And a conductive paste.

The conductive paste has a sintered density of 3.75 g / cc or more when sintered at a high temperature of 700 ° C or more.

The present invention also relates to a metal powder including the silver powder for the conductive paste; Glass frit; And an organic vehicle including a solvent and an organic binder.

The present invention can provide a silver powder having a sintered density of 3.75 g / cc or more at high temperature sintering at a temperature of 700 ° C or higher and a method for producing the same.

In addition, since the conductive paste containing the silver powder having a high sintered density according to the present invention has a low resistivity after sintering, the electrical conductivity of the electrode manufactured using the silver paste can be increased. In the case of forming the front electrode of the solar cell, The effect of increasing the efficiency can be provided.

Figure 1 shows the firing temperature profile.

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.

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.

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.

The present invention improves the sintering property of a silver powder produced by surface treatment of silver powder using fatty amines in the course of manufacture and reduces the resistivity of the electrode manufactured using the conductive paste containing the silver powder .

In particular, when the front electrode of the solar cell is formed of the conductive paste containing the silver powder produced according to the present invention, the specific resistance is lowered, thereby providing an effect of increasing the power generation efficiency of the solar cell.

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 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.

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 .

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.

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.

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.

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.

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. 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.

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) 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.

In the meantime, in the embodiment of the present invention, the addition of the above-mentioned dispersant is not excluded from the scope of right to improve the dispersibility of silver particles and to prevent agglomeration. Examples of the dispersing agent include fatty acids, fatty acid salts, surfactants, organic metals, chelating agents and protective colloids.

However, when the dispersant is added, it is preferable to control the particle diameter of the silver powder, the residual organic matter content and the crystallite diameter without adding the dispersant, since the residual organic matter content may increase and become a problem.

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 and washed by filtration after completing the silver particle precipitation reaction through the silver salt reducing step S2 Step S31. More specifically, after precipitating silver particles in the silver powder dispersion, the supernatant of the dispersion is discarded, filtered using a centrifugal separator, and the filter material is washed with pure water. The process of washing is done by completely removing the washing water from which the powder is washed. It is also possible to prevent agglomeration of the silver powder by optionally adding the above-mentioned dispersant to the reaction-completed solution before filtration.

Further, the purification step S3 according to an embodiment of the present invention may further include a post-cleaning drying and decoloring step (S34).

The surface treatment step S4 according to an embodiment of the present invention is a method that can be generally applied to the silver powder produced by the general method or the conventional method as well as the silver powder prepared through the above step.

Is a step of hydrophilizing the hydrophilic surface of the powder and performing a surface treatment using a fatty amine. More specifically, a silver powder may be added to a solution in which a surface treating agent containing a higher amine is dissolved to impart hydrophobicity to the silver powder. After that, the silver powder can be obtained through filtration, washing, drying and decoloration. When the powder is surface-treated, the powder should be well dispersed to sufficiently perform the surface treatment. If the water content is low, the dispersion efficiency becomes poor. Therefore, it is preferable to perform surface treatment with a certain amount of water content.

The surface treatment step S4 includes a first surface treatment step S41 using the first treatment agent and a second surface treatment step S42 using the second treatment agent. The first surface treatment step (S41) may be omitted, but it is more preferable to perform the first surface treatment step (S41).

The first surface treatment step (S41) is a first step of treating the surface of the silver powder with the first treatment agent so as to coat the second treatment agent more effectively. The silver powder and the first treatment agent prepared in the solvent are added and mixed and stirred To obtain a dispersion solution. More specifically, silver powder is put into a solvent, the first treatment agent is added, and the mixture is stirred at 2000 to 4000 rpm for 10 to 30 minutes using a mixer to obtain a dispersion solution. Preferably 2500 to 3500 rpm for 15 to 25 minutes to obtain a dispersion solution.

In the first surface treatment step (S41), the solvent is used in an amount of 300 to 500 parts by weight, preferably 350 to 450 parts by weight, based on 100 parts by weight of the silver powder. As the solvent, water, ethanol, isopropyl alcohol, ethylene glycol hexyl ether, diethylene glycol, butyl ether, propylene glycol, propyl ether and the like can be used, and water is preferably used.

The first surface treatment step (S41) uses 0.1 to 1.0 part by weight of the first treatment agent per 100 parts by weight of the silver powder. When the first treating agent is used in an amount of less than 0.1 part by weight, the surface treatment is not completed. If the first treating agent is used in an amount exceeding 1.0 part by weight, there is a problem that residual organic matters affect the paste characteristics or affect the electrical characteristics have. Preferably, 0.3 to 0.8 parts by weight of the first treatment agent is used per 100 parts by weight of the silver powder.

The first treatment agent may be selected from the group consisting of alkyl sulfates, ethoxylated alkyl sulfates, alkyl glyceryl ether sulfonates, alkyl ethoxy ether sulfonates, A fatty acyl glycinate, an alkyl ethoxy carboxylate, an acyl glutamate, an acyl isethionate, an alkyl sulfosuccinate, Alkyl sulfosuccinates, alkyl ethoxy sulfosuccinates, alkyl phosphate esters, acyl carcosinates, acyl aspartates, alkoxyacyl amide carboxylates, Alkoxy acyl amide carboxylate, acyl ethylene diamine triacetate, acyl hydroxyethyl Three thiocyanate (hydroxyethyl acyl isethionate), and mixtures thereof. It is preferable to use a phosphate-based material, and more preferably, a phosphate ester is used.

The second surface treatment step (S42) is a step of secondary treatment with a second treatment agent so that the surface of the silver powder is coated with the second treatment agent, and the silver powder or the primary treated silver powder is added to the second treatment agent, Followed by stirring to obtain a surface-treated silver powder. More specifically, the silver powder is added to the second treatment agent, stirred for 10 to 30 minutes, filtered, washed and dried to obtain surface-treated silver powder.

In the second surface treatment step (S42), silver powder is added to an alcohol solution containing a fatty amine as a second treatment agent and stirred. At this time, an alcohol solution in which 10 to 15 wt% of higher amine is dissolved in the total weight of the solution is used. The alcohol may be methanol, ethanol, n-propanol, benzyl alcohol, terpineol or the like, preferably ethanol.

Silver powder is mixed with 0.1 to 1.0 part by weight of high-grade amine per 100 parts by weight of powder. When the amount of the higher amine is less than 0.1 part by weight, the amount of surface treatment is insufficient and the effect is not well developed. When the amount of the high amine is more than 1.0 part by weight, the residual surface treatment agent deteriorates the electrical characteristics. Preferably, 0.2 to 0.5 parts by weight of the higher amine is mixed with 100 parts by weight of the silver powder.

The higher amine includes alkylamines having 6 to 24 carbon atoms and includes, for example, triethylamine, heptylamine, octadecylamine, hexadecylamine, decylamine, , Octylamine, didecylamine or trioctylamine. When an alkylamine having less than 6 carbon atoms is used, there is a problem that a desired effect is not exhibited. When an alkylamine having more than 24 carbon atoms is used, there is a problem that it is difficult to dissolve in a solvent and surface treatment is difficult.

Preferably octadecylamine, hexadecylamine, decylamine or octylamine, which is an alkylamine having 8 to 18 carbon atoms, which is preferably used in the following Experimental Examples The sintering characteristics and the resistivity characteristics exhibit more excellent effects.

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.

As the metal powder, silver powder produced 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.

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 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.

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.

As the metal powder, silver powder produced 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.

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.

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 a plurality of 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.

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. 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.

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.

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. 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.

Examples and Comparative Examples were prepared by mixing powder

(1) Example 1

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

The surface treatment was carried out to impart hydrophobicity to the obtained silver powder. 100 g of silver powder in 400 ml of pure water and 0.5 g of PS-810E (ADEKA) as an anionic surfactant were mixed with a homomixer (K & S company, Lab) at 3000 RPM for 20 minutes to disperse the dried silver powder.

2.7 g of octadecylamine ethanol solution (octadecylamine content: 11.25% by weight) was added to the silver powder-dispersed solution and stirred for 20 minutes. Thereafter, stirring was stopped, and the mixture was filtered using a centrifugal separator. The filter material was washed with pure water and dried at 70 DEG C for 12 hours to obtain a surface-treated silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(2) Example 2

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

The surface treatment was carried out to impart hydrophobicity to the obtained silver powder. 100 g of silver powder in 400 ml of pure water and 0.5 g of PS-810E (ADEKA) as an anionic surfactant were mixed with a homomixer (K & S company, Lab) at 3000 RPM for 20 minutes to disperse the dried silver powder.

2.7 g of hexadecylamine ethanol solution (hexadecylamine content: 11.25 wt%) was added to the silver powder-dispersed solution and stirred for 20 minutes. Thereafter, stirring was stopped, and the mixture was filtered using a centrifugal separator. The filter material was washed with pure water and dried at 70 DEG C for 12 hours to obtain a surface-treated silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(3) Example 3

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

The surface treatment was carried out to impart hydrophobicity to the obtained silver powder. 100 g of silver powder in 400 ml of pure water and 0.5 g of PS-810E (ADEKA) as an anionic surfactant were mixed with a homomixer (K & S company, Lab) at 3000 RPM for 20 minutes to disperse the dried silver powder.

2.7 g of decylamine ethanol solution (decylamine content: 11.25% by weight) was added to the silver powder-dispersed solution and stirred for 20 minutes. Thereafter, stirring was stopped, and the mixture was filtered using a centrifugal separator. The filter material was washed with pure water and dried at 70 DEG C for 12 hours to obtain a surface-treated silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(4) Example 4

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

The surface treatment was carried out to impart hydrophobicity to the obtained silver powder. 100 g of silver powder in 400 ml of pure water and 0.5 g of PS-810E (ADEKA) as an anionic surfactant were mixed with a homomixer (K & S company, Lab) at 3000 RPM for 20 minutes to disperse the dried silver powder.

2.7 g of octylamine ethanol solution (octylamine content: 11.25% by weight) was added to the silver powder-dispersed solution and stirred for 20 minutes. Thereafter, stirring was stopped, and the mixture was filtered using a centrifugal separator. The filter material was washed with pure water and dried at 70 DEG C for 12 hours to obtain a surface-treated silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(5) Example 5

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

100 g of the obtained silver powder and 2.7 g of octadecylamine ethanol solution (octylamine content: 11.25% by weight) were added to 400 mL of pure water and stirred for 20 minutes. Thereafter, stirring was stopped, and the mixture was filtered using a centrifugal separator. The filter material was washed with pure water and dried at 70 DEG C for 12 hours to obtain a surface-treated silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(6) Examples 6 to 17

A silver powder was prepared in the same manner as in Example 1 except that the surface treatment was performed with the components and contents of the treating agent shown in Table 1 below.

(7) Comparative Example 1

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. Subsequently, the first aqueous solution was stirred. After 30 seconds after the second aqueous solution was added all at once to the first aqueous solution, 2.7 g of stearic acid ethanol solution (stearic acid content: 11.25 wt%) was added and stirred for 5 minutes And the particles were grown 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. And further dried at 70 DEG C for 12 hours to obtain a silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(8) Comparative Example 2

120 g of the silver powder obtained in Comparative Example 1 was put into a small mill (sample mill) (RAP Corporation) and preliminarily pulverized for 30 seconds to add 0.36 g of octadecylamine (0.3% of octadecylamine to silver powder) After 30 seconds of decomposition, the remaining half of octadecylamine was added, followed by 30 seconds of shaking to further treat the amine.

(9) Comparative Example 3

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

100 g of the silver powder was dispersed in 400 mL pure water, and 2.7 g of stearic acid ethanol solution (11.25 wt% of stearic acid) was added to the silver powder-dispersed solution and stirred for 20 minutes. Thereafter, stirring was stopped, and the mixture was filtered using a centrifugal separator. The filter material was washed with pure water and dried at 70 DEG C for 12 hours to obtain a surface-treated silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(10) Comparative Example 4

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

100 g of the silver powder was dispersed in 400 mL of purified water, and 2.7 g of stearamide ethanol solution (stearamide content: 11.25 wt%) was added to the silver powder-dispersed solution and stirred for 20 minutes. Thereafter, stirring was stopped, and the mixture was filtered using a centrifugal separator. The filter material was washed with pure water and dried at 70 DEG C for 12 hours to obtain a surface-treated silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

(11) Comparative Examples 5 to 8

A silver powder was prepared in the same manner as in Example 1 except that the surface treatment was performed with the components and contents of the treating agent shown in Table 1 below.

(12) Comparative Example 9

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. 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, stirring was stopped, and the particles in the mixed solution were settled. Then, the supernatant of the mixed solution was discarded and the mixed solution was filtered using a centrifugal separator. The filter material was washed with pure water and dried to obtain silver powder.

100 g of the obtained silver powder and 0.5 g of Disperbyk-111 (manufactured by BYK Chemie) were added to 400 ml of pure water, and the silver powder was dispersed by stirring with a homomixer (K & S company, Lab) at 3000 RPM for 20 minutes. 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. And further dried at 70 DEG C for 12 hours to obtain a silver powder. This silver powder was pulverized in a food blender and pulverized in a Jet-mill.

Silver powder (g) The first treatment agent The second treatment agent ingredient Content (g) ingredient Content (g) Example 1 100 Phosphate type 0.5 Octadecylamine 0.3 Example 2 100 Phosphate type 0.5 Hexadecylamine 0.3 Example 3 100 Phosphate type 0.5 Decylamine 0.3 Example 4 100 Phosphate type 0.5 Octylamine 0.3 Example 5 100 - - Octadecylamine 0.3 Example 6 100 Phosphate type 0.3 Octadecylamine 0.3 Example 7 100 Phosphate type 0.8 Hexadecylamine 0.3 Example 8 100 Phosphate type 0.5 Decylamine 0.2 Example 9 100 Phosphate type 0.5 Octylamine 0.5 Example 10 100 Phosphate type 0.1 Octadecylamine 0.3 Example 11 100 Phosphate type 1.0 Hexadecylamine 0.3 Example 12 100 Phosphate type 0.5 Decylamine 0.1 Example 13 100 Phosphate type 0.5 Octylamine 1.0 Example 14 100 Phosphate type 0.5 Heptylamine 0.3 Example 15 100 Phosphate type 0.5 Didecylamine 0.3 Example 16 100 Phosphate type 0.5 Trioctylamine 0.3 Example 17 100 Phosphate type 0.5 Triethylamine 0.3 Comparative Example 1 100 Stearic acid 0.3 - - Comparative Example 2 120 Stearic acid 0.3 Octadecylamine 0.36 Comparative Example 3 100 - - Stearic acid 0.3 Comparative Example 4 100 - - stearamide 0.3 Comparative Example 5 100 Phosphate type 0.05 Octadecylamine 0.3 Comparative Example 6 100 Phosphate type 1.2 Hexadecylamine 0.3 Comparative Example 7 100 Phosphate type 0.5 Decylamine 0.05 Comparative Example 8 100 Phosphate type 0.5 Octylamine 1.2 Comparative Example 9 100 Phosphate type 0.5 - -

In Experimental Example 1, powder property analysis

(1) Specific surface area analysis

The silver powder according to the Examples and Comparative Examples was subjected to moisture removal at 100 ° C for 1 hour and then analyzed for specific surface area by nitrogen adsorption using a specific surface area measuring device (BELSORP mini-II, BEL Japan) Respectively.

(2) Analysis of particle size distribution

The particle size distribution by the laser diffraction method was measured by using a particle size distribution measuring apparatus (S3500, Microtrac) after adding 50 mg of silver powder to 30 ml of ethanol and dispersing in an ultrasonic washing machine for 3 minutes.

D10 (μm) D50 (μm) D90 (μm) Dmax ([mu] m) BET (m ² / g) Example 1 0.9 1.7 2.5 7.8 0.40 Example 2 0.9 1.8 2.6 7.8 0.42 Example 3 1.0 1.8 2.6 9.3 0.43 Example 4 1.1 1.8 2.7 9.3 0.43 Example 5 0.8 1.6 2.4 7.8 0.50 Example 6 0.8 1.7 2.4 9.3 0.40 Example 7 0.9 1.7 2.5 9.3 0.42 Example 8 1.0 1.9 2.8 9.3 0.44 Example 9 1.0 1.9 2.9 11.0 0.48 Example 10 1.0 1.8 2.8 9.3 0.50 Example 11 1.2 1.8 2.9 9.3 0.48 Example 12 1.2 2.0 3.0 11.0 0.38 Example 13 1.1 2.0 2.9 11.0 0.40 Example 14 0.9 1.6 2.3 9.3 0.42 Example 15 0.9 1.6 2.5 7.8 0.40 Example 16 0.8 1.6 2.4 7.8 0.38 Example 17 1.0 1.8 2.7 7.8 0.37 Comparative Example 1 1.0 1.7 2.7 7.8 0.44 Comparative Example 2 1.1 1.6 2.5 7.8 0.39 Comparative Example 3 0.8 1.7 2.8 11.0 0.38 Comparative Example 4 1.2 2.0 2.9 11.0 0.40 Comparative Example 5 0.9 1.7 2.4 9.3 0.40 Comparative Example 6 0.9 1.6 2.3 9.3 0.42 Comparative Example 7 1.0 1.8 2.5 9.3 0.42 Comparative Example 8 1.2 1.8 2.9 9.3 0.40 Comparative Example 9 1.1 2.0 2.9 11.0 0.48

Production Example Preparation and baking of conductive paste

ETHOCEL 占 Std200 10 g of binder mixed with 7.7% by weight of Ethylcellulose (The Dow Chemical Company) and 92.3% by weight of buthyl cabitol acetate (purified gold) and 90 g of silver powder prepared according to the examples and comparative examples were mixed with a rotary stirring vacuum de- After mixing, a conductive paste was obtained using a triple roll.

A 1 cm x 1 cm frame was formed on the alumina plate with a polyimide tape having a thickness of 200 mu m, and the conductive paste was filled and the upper surface was flattened with a slide glass. Also, the polyimide tape was removed to form a 200 μm thick film.

When the temperature was raised from 400 ° C. to 200 ° C., the temperature was raised to 750 ° C., and then the heating was stopped. ). ≪ / RTI >

Experimental Example 2 Sintering Characteristic Analysis

(1) Measurement of sintered density of electrode

The sintered densities of the silver powders according to the Examples and Comparative Examples were calcined according to the preparation examples and then measured using a Digimatic micrometer (Mitutoyo) to measure the weight (area is 1 cm ² ) Respectively.

(2) Resistivity measurement of electrode

The silver powder according to the examples and comparative examples was fired according to the preparation example, and the resistivity at a thickness of 1 μm was measured with a low resistivity meter (MCP-T700, Mitsubishi Chemical Co.) Respectively.

Electrode sintered density
(g / cc) Resistivity
(10 < ^-8 > Example 1 5.88 3.15 Example 2 6.76 3.23 Example 3 6.15 3.22 Example 4 6.34 3.62 Example 5 4.25 4.15 Example 6 5.15 3.54 Example 7 5.20 3.62 Example 8 5.76 3.61 Example 9 4.77 4.02 Example 10 4.55 4.13 Example 11 4.87 4.11 Example 12 3.88 5.45 Example 13 3.96 4.20 Example 14 3.75 4.77 Example 15 4.12 5.15 Example 16 4.26 5.02 Example 17 4.31 4.86 Comparative Example 1 3.42 6.45 Comparative Example 2 3.15 6.79 Comparative Example 3 2.76 7.22 Comparative Example 4 2.22 7.45 Comparative Example 5 2.79 7.13 Comparative Example 6 3.80 5.99 Comparative Example 7 2.45 6.92 Comparative Example 8 3.15 6.15 Comparative Example 9 3.34 6.20

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 (16)

And a second surface treatment step (S42) of surface-treating the silver powder treated first with silver powder or a first treatment agent using a second treatment agent comprising a fatty amine.
Silver powder.
The method according to claim 1,
Wherein the fatty amine comprises an alkylamine having from 6 to 24 carbon atoms,
Silver powder.
3. The method of claim 2,
The alkylamine may be selected from the group consisting of triethylamine, heptylamine, octadecylamine, hexadecylamine, decylamine, octylamine, didecylamine, Trioctylamine. ≪ RTI ID = 0.0 >
Silver powder.
The method according to claim 1,
Wherein the second surface treatment step (S42) comprises adding silver powder primary treated with silver powder or a first treatment agent to the second treatment agent, followed by stirring for 10 to 30 minutes,
Silver powder.
The method according to claim 1,
Wherein the second surface treatment step (S42) comprises mixing 0.1 to 1.0 part by weight of the high-grade amine with respect to 100 parts by weight of silver powder that has been primary treated using the silver powder or the first treatment agent,
Silver powder.
The method according to claim 1,
The second surface treatment step (S42) is a step of adding a silver powder primary treated with the silver powder or the first treatment agent to an alcohol solution containing the fatty amine and stirring the same,
Wherein the alcohol solution containing the fatty amine is a solution in which the higher amine is dissolved in an amount of 10 to 15 wt%
Silver powder.
The method according to claim 1,
The silver powder subjected to the primary treatment using the first treatment agent,
Which is a silver powder treated through a first surface treatment step (S41) in which a silver powder and a first treatment agent are added to a solvent and mixed and stirred,
Silver powder.
8. The method of claim 7,
The first treatment agent may be selected from the group consisting of alkyl sulfate, ethoxylated alkyl sulfate, alkyl glyceryl ether sulfonate, alkyl ethoxy ether sulfonate, But are not limited to, acyl methyl taurate, fatty acyl glycinate, alkyl ethoxy carboxylate, acyl glutamate, acyl isethionate, Alkyl sulfosuccinates, alkyl ethoxy sulfosuccinates, alkyl phosphate esters, acyl carcosinates, acyl aspartates, alkoxyacyl amide carbamates, Alkoxy acyl amide carboxylate, acyl ethylene diamine triacetate, acylhydroxy Til isethionate (acyl isethionate hydroxyethyl), and mixtures thereof,
Silver powder.
8. The method of claim 7,
Wherein the first surface treatment step (S41) comprises using 300 to 500 parts by weight of the solvent and 0.1 to 1.0 parts by weight of the first treatment agent per 100 parts by weight of the silver powder,
Silver powder.
8. The method of claim 7,
The first surface treatment step (S41) is a step of putting silver powder in the solvent, adding a first treatment agent, and stirring at 2000 to 4000 rpm for 10 to 30 minutes,
Silver powder.
Silver 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;
A second surface treatment step (S42) of surface-treating the obtained silver powder or the obtained silver powder by using a second treatment agent containing a fatty amine, which is a primary treatment of the obtained silver powder with a first treatment agent, Including,
A method for producing a silver powder for producing surface-treated silver powder.
12. The method of claim 11,
The silver powder subjected to the primary treatment using the first treatment agent,
Which is a silver powder treated through a first surface treatment step (S41) in which the obtained silver powder and the first treatment agent are added to a solvent and mixed and stirred,
A method for producing a silver powder for producing surface-treated silver powder.
As a silver powder having an average particle size (D50) of 1.6 to 2.0 占 퐉,
The silver powder is a silver powder surface-treated with a treatment agent containing a fatty amine,
Silver powder for conductive paste.
A metal powder comprising the silver powder for a conductive paste according to claim 13; And
A glass vehicle comprising a solvent and an organic binder; / RTI >
Conductive paste.
15. The method of claim 14,
The conductive paste has a sintered density of 3.75 g / cc or more when sintered at a temperature of 700 ° C or higher,
Conductive paste.
A metal powder comprising the silver powder for a conductive paste according to claim 13;
Glass frit; And
1. A conductive paste for a solar cell electrode, comprising an organic vehicle comprising a solvent and an organic binder.

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