WO2013018645A1 - Fine silver particles, conductive paste containing fine silver particles, conductive film and electronic device - Google Patents

Fine silver particles, conductive paste containing fine silver particles, conductive film and electronic device Download PDF

Info

Publication number
WO2013018645A1
WO2013018645A1 PCT/JP2012/068939 JP2012068939W WO2013018645A1 WO 2013018645 A1 WO2013018645 A1 WO 2013018645A1 JP 2012068939 W JP2012068939 W JP 2012068939W WO 2013018645 A1 WO2013018645 A1 WO 2013018645A1
Authority
WO
WIPO (PCT)
Prior art keywords
fine particles
silver fine
silver
crystallite diameter
less
Prior art date
Application number
PCT/JP2012/068939
Other languages
French (fr)
Japanese (ja)
Inventor
山本　洋介
石谷　誠治
岩崎　敬介
峰子 大杉
森井　弘子
林　一之
康男 柿原
哲二 飯田
Original Assignee
戸田工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2011167368A external-priority patent/JP5773148B2/en
Priority claimed from JP2011167364A external-priority patent/JP5773147B2/en
Application filed by 戸田工業株式会社 filed Critical 戸田工業株式会社
Priority to CN201280036601.7A priority Critical patent/CN103702786B/en
Priority to KR1020147001483A priority patent/KR20140047663A/en
Publication of WO2013018645A1 publication Critical patent/WO2013018645A1/en

Links

Classifications

    • 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
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/05—Metallic powder characterised by the size or surface area of the particles
    • B22F1/054—Nanosized particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites

Definitions

  • the present invention relates to a silver fine particle having an average particle size of 100 nm or more or an average particle size of less than 100 nm, and a conductive paste, a conductive film and an electronic device containing the silver fine particle, which are suitable for use as a raw material for a conductive paste capable of low-temperature firing.
  • a silver fine particle having an average particle size of 100 nm or more or an average particle size of less than 100 nm
  • a conductive paste, a conductive film and an electronic device containing the silver fine particle which are suitable for use as a raw material for a conductive paste capable of low-temperature firing.
  • the electrodes and circuit patterns of electronic devices are formed by printing electrodes and circuit patterns on a substrate using a conductive paste containing metal particles, and then baking by heating and sintering the metal particles contained in the conductive paste. And is classified into a firing paste and a polymer paste according to the heating and firing temperature. In recent years, the heating and firing temperature tends to be lowered.
  • the fired paste is generally used for ceramic substrates, and is mainly composed of metal particles, glass frit, a solvent and the like, and the heating and firing temperature thereof is about 500 ° C. or higher.
  • polymer type paste is used for membrane wiring boards, conductive adhesives, etc., and consists of a paste in which metal particles are dispersed in a resin, a curing agent, an organic solvent, a dispersing agent, etc.
  • a predetermined conductor pattern is formed on a substrate by printing or the like, and is heated and fired at a temperature up to about 250 ° C. for use.
  • silver is used as the conductive particles in the conductive paste for screen printing used for forming the circuit of the membrane wiring board.
  • Silver has a drawback that it tends to cause migration, but it is difficult to oxidize compared to copper having the same specific resistance, so it is easy to handle and is widely used.
  • a polyimide flexible substrate is generally used because it can be heated up to about 300 ° C. and has excellent heat resistance.
  • Inexpensive PET (polyethylene terephthalate) substrates and PEN (polyethylene naphthalate) substrates are being investigated as alternative materials.
  • PET substrates and PEN substrates have lower heat resistance than polyimide flexible substrates, and in particular, PET film substrates used for membrane wiring boards need to be heated and fired at 150 ° C. or lower.
  • heating and firing can be performed at a temperature lower than 200 ° C., it becomes possible to form electrodes and circuit patterns on a substrate such as polycarbonate and paper, and it is expected that the use of various electrode materials will be expanded.
  • metal particle that is a raw material for such a conductive paste that can be fired at a low temperature silver fine particles of nanometer order are expected.
  • the reason for this is that when the size of the metal particles is on the order of nanometers, the surface activity becomes high and the melting point is much lower than that of the bulk metal, so that it can be sintered at a low temperature. .
  • nanometer-order silver fine particles can be sintered at low temperatures, and heat resistance is maintained once sintered, which is also expected as a lead-free solder replacement material using a property not found in conventional solder. Has been.
  • silver fine particles of submicron to micron size have been proposed as silver fine particles that can be used for wiring materials and electrode materials of electronic devices, and silver fine particles that can be fired at low temperature.
  • Spherical silver powder with limited ratio Patent Document 1
  • average particle diameter, crystallite diameter and silver fine particles with limited ratio of average particle diameter to crystallite diameter Patent Document 2
  • tap density laser diffraction method average particle diameter
  • silver powder with a specific surface area limited Patent Document 3
  • a method for producing silver fine particles having an average primary particle diameter of 0.05 to 1.0 ⁇ m and a crystallite diameter of 20 to 150 nm Patent Document 4
  • spherical silver powder having a sharp particle size distribution and high dispersibility Patent Document 5
  • primary particle size 0.07 to 4.5 ⁇ m
  • crystallite size of 20 nm or more Crystal silver powder Patent Document 6
  • the silver fine particles disclosed in Patent Document 1 to Patent Document 6 are all limited in average particle diameter, crystallite diameter, BET specific surface area value, etc., but the Miller index (111) by X-ray diffraction is limited. And the ratio of the crystallite diameter in (200) [crystallite diameter D X (111) / crystallite diameter D X (200)] is not taken into consideration.
  • X (111) / crystallite diameter D X (200)] is less than 1.40, it is difficult to obtain silver fine particles having good low-temperature sinterability.
  • the crystallite diameter D X (111) exceeds 20 nm, the crystallite diameter of the silver fine particles is large, so that the reactivity inside the silver fine particles is low, which is disadvantageous for low-temperature sintering.
  • a technical problem of the present invention is to provide silver fine particles suitable as a raw material for conductive paste that can be fired at a low temperature. Further, the average particle diameter of the obtained silver fine particles is in a wide range, and it is particularly desirable to obtain silver fine particles of 30 nm or more and less than 100 nm and 100 nm or more and less than 1 ⁇ m.
  • the ratio of the crystallite diameter in the Miller indices (111) and (200) by X-ray diffraction is 1.40 or more.
  • Silver fine particles characterized by the present invention (Invention 1).
  • this invention is a silver fine particle of this invention 1 whose average particle diameter (DSEM ) is 100 nm or more and less than 1 micrometer (invention 2).
  • the present invention is the silver fine particle according to the first or second aspect of the present invention, wherein the crystallite diameter D X (111) at the Miller index (111) is 20 nm or less (Invention 3).
  • the present invention is the silver fine particles according to any one of the present inventions 1 to 3, wherein the crystallite diameter D X (200) at the Miller index (200) is 14 nm or less (Invention 4).
  • the present invention is the invention according to any one of the present inventions 1 to 4, wherein the particle surface of the silver fine particles is coated with one or more kinds selected from polymer dispersants having a number average molecular weight of 1,000 or more. Silver fine particles (Invention 5).
  • this invention is a silver fine particle of this invention 1 whose average particle diameter (D SEM ) is 30 nm or more and less than 100 nm (this invention 6).
  • the present invention is the silver fine particles according to the first or sixth aspect of the present invention, wherein the crystallite diameter D X (111) at the Miller index (111) is 25 nm or less (Invention 7).
  • the present invention is the silver fine particles according to any one of the present inventions 1, 6, and 7 having a crystallite diameter D X (200) of Miller index (200) of 15 nm or less (Invention 8).
  • the present invention is the silver fine particles according to any one of claims 1 and 6 to 8, wherein the surface of the silver fine particles is coated with a polymer compound having a molecular weight of 10,000 or more (Invention 9).
  • present invention is a conductive paste containing the silver fine particles according to any one of claims 1 to 9 (present invention 10).
  • the present invention is a conductive film formed using the conductive paste according to claim 10 (Invention 11).
  • the present invention also provides an electronic device having the conductive film according to claim 11 (present invention 11).
  • the silver fine particles according to the present invention have a crystallite diameter ratio [crystallite diameter D X (111) / crystallite diameter D X (200)] of 1.40 and Miller index (111) by X-ray diffraction of 1.40. Because of the above, it is suitable as a raw material for conductive paste and the like that can be fired at a low temperature.
  • the silver fine particles according to the present invention have a crystallite diameter ratio [crystallite diameter D X (111) / crystallite diameter D X (200)] of 1.40 and Miller index (111) by X-ray diffraction of 1.40. Silver fine particles characterized by the above.
  • the average particle size of the silver fine particles of the present invention can be determined over a wide range depending on the conditions required for the application. From the viewpoint of the production method, the average particle size (D SEM ) is 100 nm or more (first embodiment). And an average particle diameter (D SEM ) of less than 100 nm (second embodiment).
  • the average particle size (D SEM ) of the silver fine particles according to the present invention is 100 nm or more, preferably 100 nm or more and less than 1 ⁇ m, more preferably 100 to 500 nm.
  • the average particle diameter (D SEM ) is in the above range, it is easy to cope with finer wiring and electrodes.
  • the average particle size (D SEM ) is less than 100 nm, sintering is likely to occur even at room temperature, and the dispersibility and dispersion stability in the conductive paste tend to be reduced. Prescribing may be required.
  • the average particle diameter (D SEM ) exceeds 1 ⁇ m, the sinterability at low temperatures is lowered, which is not preferable.
  • the particle size is too large, it is difficult to refine an electronic device obtained using the particle size.
  • Ratio of crystallite diameter in Miller index (111) and (200) by X-ray diffraction of silver fine particles according to the first aspect of the present invention [crystallite diameter D X (111) / crystallite diameter D X (200)] Is 1.40 or more, preferably 1.44 or more, more preferably 1.48 or more.
  • the ratio of the crystallite diameter D X (111) to the crystallite diameter D X (200) is 1.40 or more, silver fine particles having excellent low-temperature sinterability can be obtained.
  • the crystallite diameter D X (111) in the Miller index (111) by X-ray diffraction of the silver fine particles according to the first aspect of the present invention is preferably 20 nm or less, more preferably 10 to 19 nm, still more preferably. 10 to 18 nm.
  • the crystallite diameter D X (111) exceeds 20 nm, the reactivity in the silver fine particles is lowered, and the low-temperature sinterability is impaired.
  • the crystallite diameter D X (111) is less than 10 nm, the silver fine particles become unstable and partial sintering and fusion start even at room temperature, which is not preferable.
  • the crystallite diameter D X (200) in the Miller index (200) by X-ray diffraction of the silver fine particles according to the first aspect of the present invention is preferably 14 nm or less, more preferably 13 nm or less, still more preferably 12 nm. It is as follows.
  • the crystallite diameter D X (200) is preferably smaller so that [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40 or more.
  • the low-temperature sinterability of the silver fine particles according to the first aspect of the present invention is the change rate of the crystallite diameter by heating described later [(crystallite diameter of silver fine particles after heating at 150 ° C. for 30 minutes / silver fine particles before heating Crystallite diameter) ⁇ 100], and the change rate of the crystallite diameter by heating at 150 ° C. is preferably 120% or more, more preferably 125% or more. When the change rate of the crystallite diameter is less than 120%, it cannot be said that the low-temperature sinterability is excellent. In the present invention, when heated at 210 ° C. for 30 minutes, the change rate of the crystallite diameter is preferably 150% or more, and more preferably 170% or more.
  • the BET specific surface area value of the silver fine particles according to the first aspect of the present invention is preferably 5 m 2 / g or less. When the BET specific surface area value exceeds 5 m 2 / g, the viscosity of the conductive paste obtained by using this is not preferable.
  • the average particle diameter (D SEM ) of the silver fine particles according to the second aspect of the present invention is less than 100 nm, preferably 30 nm or more and less than 100 nm, more preferably 35 nm or more and less than 100 nm.
  • D SEM average particle diameter
  • the average particle diameter (D SEM ) is in the above range, it is easy to refine an electronic device obtained using the average particle diameter (D SEM ).
  • the average particle size (D SEM ) is less than 30 nm, the surface activity of the silver fine particles increases, and it is not preferable because a large amount of organic matter or the like needs to be adhered in order to stably maintain the fine particle size. .
  • Ratio of crystallite diameter in Miller index (111) and (200) by X-ray diffraction of silver fine particles according to the second aspect of the present invention [crystallite diameter D X (111) / crystallite diameter D X (200)] Is 1.40 or more, preferably 1.44 or more, more preferably 1.48 or more.
  • the ratio of the crystallite diameter D X (111) to the crystallite diameter D X (200) is 1.40 or more, silver fine particles having excellent low-temperature sinterability can be obtained.
  • the crystallite diameter D X (111) in the Miller index (111) by X-ray diffraction of the silver fine particles according to the second aspect of the present invention is preferably 25 nm or less, more preferably 23 to 10 nm, still more preferably 20 to 10 nm.
  • the crystallite diameter D X (111) exceeds 25 nm, the reactivity in the silver fine particles is lowered, and the low-temperature sinterability is impaired.
  • the crystallite diameter D X (111) is less than 10 nm, the silver fine particles become unstable and partial sintering and fusion start even at room temperature, which is not preferable.
  • the crystallite diameter D X (200) in the Miller index (200) by X-ray diffraction of the silver fine particles according to the second aspect of the present invention is preferably 15 nm or less, more preferably 14 nm or less, still more preferably 13 nm. It is as follows.
  • the crystallite diameter D X (200) is preferably smaller so that [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40 or more.
  • the low-temperature sinterability of the silver fine particles according to the second aspect of the present invention is the change rate of crystallite diameter by heating described later [(crystallite diameter of silver fine particles after heating at 150 ° C. for 30 minutes / silver fine particles before heating (Crystallite diameter) ⁇ 100], and the change rate of the crystallite diameter by heating at 150 ° C. is preferably 150% or more, more preferably 160% or more. When the change rate of the crystallite diameter is less than 150%, it cannot be said that the low-temperature sinterability is excellent. In the present invention, when heated at 210 ° C. for 30 minutes, the change rate of the crystallite diameter is preferably 180% or more, and more preferably 200% or more.
  • the BET specific surface area value of the silver fine particles according to the second aspect of the present invention is preferably 10 m 2 / g or less, more preferably 8 m 2 / g or less.
  • the BET specific surface area value exceeds 10 m 2 / g, the viscosity of the conductive paste obtained by using this is not preferable.
  • the particle shape of the silver fine particles according to the first and second aspects of the present invention is preferably spherical or granular.
  • the silver fine particles of the present invention are preferably coated with one or more selected from polymer dispersants.
  • the polymer dispersant is properly used depending on the number average molecular weight.
  • the particle surface of the silver fine particles is preferably coated with one or more selected from polymer dispersing agents having a number average molecular weight of 1,000 or more.
  • the number average molecular weight of the dispersant is preferably 1,000 or more, more preferably 1,000 to 150,000, and still more preferably 5,000 to 100,000.
  • the silver fine particle powder obtained by surface-treating a dispersant having a number average molecular weight of less than 1,000 has an insufficient effect of treating the dispersant, and silver fine particles tend to aggregate in the subsequent pulverization treatment.
  • the number average molecular weight exceeds 150,000, the viscosity of the dispersant becomes high, and it becomes difficult to uniformly treat the surface of the silver fine particles.
  • the surface of the silver fine particles is preferably coated with a polymer compound (polymer dispersing agent) having a molecular weight of 10,000 or more.
  • a polymer compound polymer dispersing agent
  • the molecular weight is less than 10,000, agglomerates are produced in the subsequent pulverization treatment, and the resulting silver fine particles are not preferable because dispersibility in the conductive paste becomes difficult.
  • the upper limit of the molecular weight of the polymeric dispersant is about 100,000. If the molecular weight is higher than this, the viscosity increases, and uniform processing on the surface of the silver fine particles becomes difficult.
  • the dispersant has both an acid value and an amine value. It is preferable to use a dispersant (having both an acidic functional group and a basic functional group) or a dispersant having an acid value and a dispersant having an amine value in combination.
  • the coating amount of the dispersant is preferably 0.1 to 3.0% by weight, more preferably 0.2 to 2.5% by weight based on the silver fine particle powder, although it depends on the BET surface area value of the silver fine particles. .
  • the amount is less than 0.1% by weight, the amount of the dispersant is insufficient, and the silver fine particle powder tends to aggregate in the subsequent pulverization treatment.
  • the amount exceeds 3.0% by weight, aggregation of the silver fine particle powder can be suppressed, but an organic component not involved in conductivity increases, which is not preferable.
  • polymer dispersant those commercially available as pigment dispersants can be used, and specifically, ANTI-TERRA-U, ANTI-TERRA-205, DISPERBYK-101, DISPERBYK-102. , DISPERBYK-106, DISPERBYK-108, DISPERBYK-109, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-116, DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK-142, DISPERBYK-142, DISPERBYK-142, DISPERBYK-142 -162, DISPERBYK-163, DISPERBYK-164, DISPERBYK-166, D SPERBYK-167, DISPERBYK-168, DISPERBYK-170, DISPERBYK-171, DISPERBYK-
  • the silver fine particles according to the present invention are prepared by adding a reducing agent-containing aqueous solution to a silver salt complex-containing aqueous solution to reduce and precipitate silver fine particles, or by adding a silver nitrate aqueous solution to a reducing solution and reducing and precipitating silver fine particles. It can be obtained by any method for producing silver fine particles.
  • a method for producing silver fine particles having an average particle diameter (D SEM ) of less than 100 nm according to the second aspect of the present invention a solvent reaction in which an alcohol solution of a silver salt complex is added to a reducing agent solution to reduce and precipitate silver fine particles.
  • a method for producing silver fine particles in the system can also be adopted. In any case, it is important to perform all steps from reaction to drying in a temperature range of 30 ° C. or lower.
  • the silver salt complex-containing aqueous solution and the reducing agent-containing aqueous solution are respectively prepared in advance.
  • the silver salt complex in the present invention can be obtained by mixing silver nitrate or silver acetate as a silver raw material with aqueous ammonia, ammonium salt or chelate compound.
  • aqueous ammonia, ammonium salt or chelate compound As the addition amount of ammonia, since the coordination number of ammonia in the ammine complex is 2, it is preferable to add 2 mol or more of ammonia to 1 mol of silver.
  • the amount of ammonia added is more preferably at least 4 mol, and even more preferably at least 10 mol per mol of silver.
  • erythorbic acid ascorbic acid, alkanolamine, hydroquinone, glucose, pyrogallol, hydrazine, hydrogen peroxide and formaldehyde
  • an organic reducing agent is preferably used, and more preferably erythorbic acid or ascorbic acid.
  • the amount of reducing agent added is preferably 1.0 mol or more, and more preferably 1.0 to 2.0 mol, per 1 mol of silver.
  • the amount exceeding 2.0 moles relative to 1 mole of silver is not preferable because the generated silver fine particles tend to aggregate.
  • the reducing solution and the silver nitrate aqueous solution are prepared in advance.
  • the aqueous silver nitrate solution in the present invention can be obtained by mixing silver nitrate with ion-exchanged water or pure water.
  • the concentration of silver nitrate in the aqueous solution is preferably in the range of 0.08 to 2.0 mol / l, more preferably 0.1 to 1.8 mol / l.
  • the reducing solution can be obtained by mixing and stirring ammonia water and ion exchange water or pure water and a reducing agent.
  • a reducing agent used for a reducing liquid the above-mentioned reducing agent can be used.
  • the amount of reducing agent added is preferably 1.0 mol or more, and more preferably 1.0 to 2.0 mol, per 1 mol of silver.
  • the amount exceeding 2.0 moles relative to 1 mole of silver is not preferable because the generated silver fine particles tend to aggregate.
  • the liquid temperature is kept at 18 ° C. or lower, and a silver salt complex-containing aqueous solution and a reducing agent-containing aqueous solution or a reducing solution and a silver nitrate aqueous solution are used. It is preferable to adjust so that the liquid temperature does not exceed 20 ° C. when mixing and stirring.
  • the reaction temperature exceeds 20 ° C., the crystallite diameter D X (111) of the silver fine particles increases, and the ratio of crystallite diameter D X (111) / crystallite diameter D X (200) is 1.40. This is not preferable because the low temperature sinterability is impaired.
  • the addition of the reducing agent-containing aqueous solution to the silver salt complex-containing aqueous solution or the addition of the silver nitrate aqueous solution to the reducing solution is preferably performed in as short a time as possible, more preferably within 20 seconds, and even more preferably within 15 seconds. is there.
  • the addition time of the reducing agent-containing aqueous solution to the silver salt complex-containing aqueous solution or the addition time of the silver nitrate aqueous solution to the reducing solution is prolonged, the generated silver fine particles are aggregated to increase the particle size and the particle size distribution. There is a tendency.
  • the silver fine particle cake obtained was redispersed in a hydrophilic organic solvent, and the water on the surface of the silver fine particles was replaced with a hydrophilic organic solvent. Dry using vacuum drying. When the drying temperature exceeds 30 ° C., the crystallite diameter D X (111) of the silver fine particles increases, and the ratio of crystallite diameter D X (111) / crystallite diameter D X (200) is 1.40. This is not preferable because the low temperature sinterability is impaired. By replacing the water on the surface of the silver fine particles with a hydrophilic organic solvent, it is possible to prevent the silver fine particles after drying from being firmly agglomerated with each other, and subsequent grinding treatment or surface treatment / grinding treatment, etc. It becomes easy.
  • hydrophilic organic solvent examples include methanol, ethanol and propanol, acetone and the like. Considering removal of the solvent by drying, methanol and ethanol are preferred.
  • silver fine particles having any of the average particle diameters of the first and second embodiments can be produced.
  • a method for controlling the particle diameter adjustment of the concentration of silver nitrate in the aqueous silver nitrate solution or Adjustment of the ammonia water concentration in the reducing solution can be mentioned.
  • the silver fine particles having the average particle diameter of the first aspect can be produced mainly.
  • the silver nitrate in the aqueous silver nitrate solution can be mainly produced by lowering the concentration of the aqueous solution and increasing the concentration of the ammonia water in the reducing solution.
  • the alcohol solution of a silver salt complex in a solvent reaction system in which an alcohol solution of a silver salt complex is added to a reducing agent solution to reduce and precipitate silver fine particles is water-soluble or water-soluble with silver nitrate in the alcohol solution and has 2 to 2 carbon atoms. It can be obtained by mixing one or more of the four aliphatic amines.
  • the aliphatic amine is preferably 2.0 to 2.5 moles, more preferably 2.0 to 2.3 moles per mole of silver nitrate. When the amount of the aliphatic amine is less than 2.0 mol with respect to 1 mol of silver nitrate, large grains tend to be generated.
  • aliphatic amine having 2 to 4 carbon atoms it is important to use a water-soluble or water-soluble aliphatic amine, specifically, ethylamine, n-propylamine, iso-propylamine, n-butylamine, iso- Butylamine and the like can be used, but n-propylamine and n-butylamine are preferable in view of the low-temperature sintering property and handling property of the silver fine particles.
  • alcohols in the solvent reaction system those having compatibility with water can be used. Specifically, methanol, ethanol, propanol, isopropanol, and the like can be used, and methanol and ethanol are preferable. These alcohols may be used alone or in combination.
  • the reducing agent solution in the solvent reaction system can be obtained by dissolving ascorbic acid or erythorbic acid in water, or dissolving ascorbic acid or erythorbic acid in water and then adding alcohol and mixing.
  • Ascorbic acid or erythorbic acid is preferably 1.0 to 2.0 moles, more preferably 1.0 to 1.8 moles per mole of silver nitrate.
  • ascorbic acid or erythorbic acid exceeds 2.0 mol with respect to 1 mol of silver nitrate, the generated silver fine particles tend to aggregate, which is not preferable.
  • the addition of the alcohol solution of the silver salt complex to the reducing agent solution in the solvent reaction system is performed by dropping the alcohol solution of the silver salt complex into the reducing solution.
  • the reaction temperature in the reduction reaction is in the range of 15 to 30 ° C., more preferably 18 to 30 ° C. When the reaction temperature exceeds 30 ° C., the crystallite size increases, which is not preferable.
  • the dropping rate is preferably 3 ml / min or less. When the dropping time is short, the particle size and the crystallite size tend to increase, which is not preferable.
  • the silver fine particles of the present invention can be obtained by drying the washed silver fine particles at a temperature of 30 ° C. or lower or by vacuum drying and then pulverizing them by a conventional method.
  • the drying temperature exceeds 30 ° C.
  • the crystallite diameter D X (111) of the silver fine particles increases, and the ratio of crystallite diameter D X (111) / crystallite diameter D X (200) is 1.40. This is not preferable because the low temperature sinterability is impaired.
  • the silver fine particles of the present invention can be obtained by pulverizing the silver fine particles after drying by a conventional method.
  • the silver fine particles according to the present invention are preferably subjected to a surface treatment with a polymer dispersant before the pulverization treatment.
  • a surface treatment with a polymer dispersant before the pulverization treatment.
  • the coating amount with a polymer compound having a molecular weight of 1,000 or more is preferably 0.1 to 3.0% by weight, more preferably 0.2 to 2.5% by weight, based on the silver fine particles.
  • the coating amount with a polymer compound having a molecular weight of 10,000 or more is preferably 0.2 to 4% by weight, more preferably 0.3 to 3% by weight, based on the silver fine particles.
  • the treatment amount with the polymer compound is within the above range, a sufficient treatment effect by the pulverization treatment can be obtained.
  • the surface treatment of the silver fine particles with the polymer compound is carried out by redispersing the silver fine particles after substitution and drying with a hydrophilic organic solvent in a polymer compound solution obtained by dissolving the polymer compound in the organic solvent, for 30 to 300 minutes. After gently stirring, the organic solvent is removed, and drying is performed at 30 ° C. or lower using a dryer or vacuum drying.
  • the conductive paste according to the present invention may be in any form of a fired paste and a polymer paste.
  • the conductive paste is composed of the silver fine particles and the glass frit according to the present invention.
  • Other components may be blended.
  • a polymer type paste it consists of silver fine particles and a solvent according to the present invention, and if necessary, other components such as a binder resin, a curing agent, a dispersant, and a rheology modifier may be blended.
  • binder resin those known in the art can be used.
  • cellulose resins such as ethyl cellulose and nitrocellulose
  • various modified materials such as polyester resins, urethane modified polyester resins, epoxy modified polyester resins, and acrylic modified polyesters.
  • These binder resins can be used alone or in combination of two or more.
  • solvent those known in the art can be used, and examples thereof include tetradecane, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, amylbenzene, p-cymene, tetralin, and petroleum aromatic hydrocarbon mixtures.
  • Hydrocarbon solvents ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, propylene glycol mono-t-butyl ether, diethylene glycol monoethyl ether, diethylene glycol Monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tri Ether or glycol ether solvents such as propylene glycol monomethyl ether; glycol ester solvents such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate Ketone solvents such as methyl isobutyl ketone and cyclohexanone; terpen
  • the content of silver fine particles in the conductive paste varies depending on the application, but it is preferably as close to 100% by weight as possible, for example, in the case of wiring formation.
  • the conductive paste according to the present invention is obtained by mixing and dispersing each component using various kneaders and dispersers such as a laika machine, a pot mill, a three roll mill, a rotary mixer, a twin screw mixer, and the like. Can do.
  • the conductive paste according to the present invention can be applied to various coating methods such as screen printing, ink jet method, gravure printing, transfer printing, roll coating, flow coating, spray coating, spin coating, dipping, blade coating, and plating.
  • the conductive paste according to the present invention is used for forming electrodes such as FPD (flat panel display), solar cell, organic EL, wiring for LSI substrates, and wiring for filling fine trenches, via holes, contact holes, etc. It can be used as a material.
  • FPD flat panel display
  • organic EL organic EL
  • wiring for LSI substrates and wiring for filling fine trenches, via holes, contact holes, etc.
  • It can be used as a material.
  • FPD flat panel display
  • organic EL organic EL
  • the important point in the present invention is that the ratio of the crystallite diameter in the Miller indices (111) and (200) by X-ray diffraction [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40. This is the fact that the silver fine particles described above can be fired at a low temperature.
  • the average particle diameter of the silver fine particles is (D SEM ), preferably 30 nm or more and less than 1 ⁇ m, and a very wide range of average particle diameters can be selected.
  • the silver fine particles according to the present invention are excellent in low-temperature sinterability is unclear, but as a result of many experiments conducted by the present inventors, the silver fine particles excellent in low-temperature sinterability are all crystalline. It has been found that the ratio of crystal diameters [crystallite diameter D X (111) / crystallite diameter D X (200)] has a value of 1.40 or more. This is considered to indicate that the larger the ratio of the crystallite diameter D X (111) and the crystallite diameter D X (200), the more unstable the crystal lattice is, and the more unstable the silver fine particles are. It is done.
  • Examples 1-1 to 1-9, Comparative Examples 1-1 to 1-5, Examples 2-1 to 2-9, Comparative Examples 2-1 to 2-5, and Examples Examples 3-1 to 3-9 and comparative examples 3-1 to 3-5 are examples in the first aspect of the present invention.
  • Examples 5-1 to 5-13 and Comparative examples 5-1 to 5-7 are examples in the first aspect of the present invention.
  • the average particle diameter of the silver fine particles was obtained by taking a photograph of the particles using a scanning electron micrograph “S-4800” (manufactured by HITACHI), measuring the particle diameter of 100 or more particles using the photograph, The value was calculated and taken as the average particle size (D SEM ).
  • the specific surface area of the silver fine particles was represented by a value measured by BET method using “Monosorb MS-11” (manufactured by Kantachrome Co., Ltd.).
  • the crystallite diameter D X (111) and the crystallite diameter D X (200) of the silver fine particles are obtained by using an X-ray diffractometer “RINT2500” (manufactured by Rigaku Corporation) and a plane index using Cu K ⁇ rays as a radiation source.
  • the half widths of the peaks on the (1, 1, 1) plane and the (2, 0, 0) plane were obtained, and the crystallite diameter was calculated from the Scherrer equation.
  • the ratio of the crystallite diameter in the Miller index (111) and (200) by X-ray diffraction of the silver fine particles is the above-mentioned crystallite diameter D X (111) and crystallite diameter D X (200). D X (111) / crystallite diameter D X (200)].
  • Rate of change of the crystallite diameter by heating the silver particles is the crystallite size after the fine silver particles were heated at 0.99 ° C. 30 min D X of silver particles before heating (111) crystallite diameter D X (111 ) And calculated according to the following formula 1. Note that the rate of change in crystallite diameter was determined in the same manner when the heating condition was changed to 210 ° C. for 30 minutes.
  • the characteristics of the conductive coating film using the firing paste in the example of the first aspect of the present invention were determined by the following method. That is, a baking type conductive paste described later is applied on an alumina substrate, pre-dried at 120 ° C. for 30 minutes, and then heated at 200 ° C., 300 ° C., 400 ° C., 500 ° C., and 600 ° C. for 30 minutes.
  • the measured conductive film was measured using a four-terminal electrical resistance measuring device “Loresta GP / MCP-T600” (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), and the specific resistance was calculated from the sheet resistance and film thickness.
  • the specific resistance of the conductive coating film in the example of the first aspect of the present invention is such that the conductive paste described later is applied on a polyimide film, preliminarily dried at 120 ° C., and then 150 ° C., 210 ° C. and 300 ° C.
  • Each conductive film obtained by heating and curing at each temperature for 30 minutes was measured using a four-terminal electrical resistance measuring device “Loresta GP / MCP-T600” (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), and sheet resistance The specific resistance was calculated from the film thickness.
  • Example 1-1 Production of silver fine particles> After adding 739 g of erythorbic acid (1.5 mol with respect to 1 mol of silver), 32.3 L of pure water and 780 g of ammonia water (25%) (4.1 mol with respect to 1 mol of silver) as a reducing agent to a 50 L reaction tower, While reducing to 18 ° C. or lower, mixing and stirring were performed to prepare a reducing solution. Separately, 475 g of silver nitrate and 6,300 g of pure water were added to a 20 mL plastic container, and then mixed and stirred while cooling to 18 ° C. or lower to prepare a silver nitrate aqueous solution.
  • an aqueous silver nitrate solution was added to the reducing solution while stirring (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using a filter paper, and then washed and filtered using pure water until the conductivity of the filtrate reached 7 ⁇ S / cm.
  • the obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours.
  • a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) was dispersed in a liquid for mixing pure water and methanol (water: methanol ratio 1:10).
  • 300 g of the obtained silver fine particles were added (0.8 wt% with respect to the silver fine particles), dried in a vacuum dryer at 25 ° C. for 12 hours, and then pulverized by a jet type pulverizer. Silver fine particles were obtained.
  • the obtained silver fine particles have a granular shape, an average particle diameter (D SEM ) of 268 nm, a crystallite diameter D X (111) of 14.2 nm, a crystallite diameter D X (200) of 9.0 nm, D X ( 111) / D X (200) is 1.58, BET specific surface area value is 1.5 m 2 / g, change rate of crystallite diameter (150 ° C. ⁇ 30 minutes) is 128%, change rate of crystallite diameter (210 ° C. ⁇ 30 minutes) was 179%.
  • Example 2-1 Production of conductive paste (fired paste)> Silver fine particles of Example 1-1 2.5 parts by weight of ethyl cellulose resin, 2.5 parts by weight of lead-free glass frit, 3.0 parts by weight of dinormal butyl phthalate and texanol / 1-phenoxy-2- After adding 15.4 parts by weight of propanol (1: 1) and performing premixing using a rotating / revolving mixer “Awatori Nertaro ARE-310” (registered trademark, manufactured by Sinky Corporation), three rolls The mixture was uniformly kneaded and dispersed to obtain a conductive paste (fired paste) of Example 2-1.
  • the conductive paste (baked paste) obtained above is applied onto an alumina substrate, pre-dried at 120 ° C. for 30 minutes, and then heated at 200 ° C., 300 ° C., 400 ° C., 500 ° C., and 600 ° C. for 30 minutes. As a result, a conductive coating film was obtained.
  • the temperature at which the sheet specific resistance of the obtained conductive coating film was 1.0 ⁇ 10 ⁇ 5 ⁇ ⁇ cm or less was 195 ° C.
  • the specific resistance when heat-treated at 120 ° C. for 30 minutes is 7.7 ⁇ 10 ⁇ 5 ⁇ ⁇ cm, and the specific resistance when heat-treated at 200 ° C. for 30 minutes is 9.1 ⁇ 10 ⁇ 6 ⁇ ⁇ cm.
  • the specific resistance was 4.7 ⁇ 10 ⁇ 6 ⁇ ⁇ cm when heat-treated at 400 ° C. for 30 minutes.
  • Example 3-1 Production of conductive paste (polymer type paste)> 11.0 parts by weight of polyester resin and 1.4 parts by weight of curing agent with respect to 100 parts by weight of silver fine particles of Example 1-1, and diethylene glycol monoethyl so that the content of silver fine particles in the conductive paste is 70 wt%. After adding ether and premixing, the mixture was uniformly kneaded and dispersed using three rolls to obtain the conductive paste of Example 3-1.
  • the conductive paste (polymer type paste) obtained above was applied onto a polyimide film having a thickness of 50 ⁇ m and heated at 120 ° C., 210 ° C. and 300 ° C. for 30 minutes, respectively, to obtain a conductive coating film.
  • the specific resistance when the obtained conductive film is heat-treated at 120 ° C. for 30 minutes is 3.7 ⁇ 10 ⁇ 4 ⁇ ⁇ cm, and the specific resistance when heat-treated at 210 ° C. for 30 minutes is 2.8. ⁇ a 10 -6 ⁇ ⁇ cm, the specific resistance in the case of heat treatment at 300 ° C. 30 minutes was 9.8 ⁇ 10 -6 ⁇ ⁇ cm.
  • Silver fine particles and a conductive paste were prepared according to Example 1-1, Example 2-1, and Example 3-1. Various characteristics of each production condition and the obtained silver fine particle powder and electric paste are shown.
  • the particles of Comparative Example 1-5 are commercially available micron-sized silver particle powders.
  • Example 1-6 Production of silver fine particles> After adding 595 g of silver nitrate, 38 L of pure water and 2,381 g of ammonia water (25%) (10.0 mol to 1 mol of silver) as a silver raw material to a 50 L reaction tower, the mixture was mixed while cooling to 10 ° C. or less. Stirring was performed to prepare a silver salt complex aqueous solution. Separately, after adding 925 g of erythorbic acid (1.5 mol with respect to 1 mol of silver) and 8,333 g of pure water as a reducing agent to a 20 L plastic container, mixing and stirring are performed while cooling to 10 ° C. or less. A reducing agent-containing aqueous solution was prepared.
  • the reducing agent-containing aqueous solution was added to the silver salt complex aqueous solution with stirring while cooling the reaction system to 10 ° C. or less (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using a filter paper, and then washed and filtered using pure water until the electric conductivity of the filtrate reached 20 ⁇ S / cm.
  • the obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours.
  • 3.6 g of a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) was dispersed in a pure water / methanol mixture (water: methanol ratio 1:10).
  • 300 g of the obtained silver fine particles were added (1.2% by weight based on the silver fine particles), dried in a vacuum dryer at 25 ° C. for 12 hours, and then pulverized by a jet type pulverizer.
  • Silver fine particles were obtained.
  • Table 4 shows the manufacturing conditions and various characteristics of the obtained conductive coating film.
  • Table 5 shows the manufacturing conditions and various characteristics of the obtained conductive coating film.
  • Example 4-1 Production of silver fine particles> After adding 739 g of erythorbic acid (1.5 mol with respect to 1 mol of silver), 33.4 L of pure water and 3,808 g of ammonia water (25%) (20 mol with respect to 1 mol of silver) as a reducing agent to a 50 L reaction tower, While reducing to 18 ° C. or lower, mixing and stirring were performed to prepare a reducing solution. Separately, 475 g of silver nitrate and 1,900 g of pure water were added to a 20 L plastic container, and then mixed and stirred while cooling to 18 ° C. or lower to prepare a silver nitrate aqueous solution.
  • an aqueous silver nitrate solution was added to the reducing solution while stirring (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using filter paper, and then washed and filtered using pure water until the conductivity of the filtrate reached 38 ⁇ S / cm.
  • the obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours.
  • 4.2 g of a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) dispersed in a methanol solution was added to 300 g of the obtained silver fine particles (1 per silver fine particle). 4% by weight) and after stirring and mixing for 90 minutes, the methanol was distilled off.
  • the fine particles of Example 4-1 were obtained by pulverization with a jet pulverizer.
  • the obtained silver fine particles have a granular shape, the average particle diameter (D SEM ) is 86.0 nm, the crystallite diameter D X (111) is 15.4 nm, the crystallite diameter D X (200) is 9.5 nm, D X (111) / D X (200) is 1.62, BET specific surface area value is 2.9 m 2 / g, change rate of crystallite diameter (150 ° C. ⁇ 30 minutes) is 118%, The rate of change (210 ° C. ⁇ 30 minutes) was 145%.
  • Example 5-1 Production of conductive paste> Diethylene glycol monoethyl such that 11.0 parts by weight of the polyester resin and 1.4 parts by weight of the curing agent with respect to 100 parts by weight of the silver fine particles of Example 4-1 and the content of the silver fine particles in the conductive paste is 70 wt%. Ether is added and premixed using a rotating / revolving mixer “Awatori Nertaro ARE-310” (registered trademark, manufactured by Sinky Corporation), and then uniformly mixed and dispersed using three rolls. Conductive paste was obtained.
  • the conductive paste obtained above was applied onto a polyimide film having a thickness of 50 ⁇ m and heated at 120 ° C., 210 ° C. and 300 ° C. for 30 minutes, respectively, to obtain a conductive coating film.
  • the specific resistance when the obtained conductive coating film is heat-treated at 120 ° C. for 30 minutes is 1.5 ⁇ 10 ⁇ 5 ⁇ ⁇ cm, and the specific resistance when heat-treated at 210 ° C. for 30 minutes is 6.8. ⁇ a 10 -6 ⁇ ⁇ cm, the specific resistance in the case of heat treatment at 300 ° C. 30 minutes was 3.1 ⁇ 10 -6 ⁇ ⁇ cm.
  • Silver fine particles and a conductive paste were produced according to Example 4-1 and Example 5-1. Various characteristics of each production condition and the obtained silver fine particle powder and electric paste are shown.
  • Example 4-6 Production of silver fine particles> After adding 475 g of silver nitrate and 3,808 g of ammonia water (25%) as a silver raw material to a 50 L reaction tower and mixing and stirring while cooling to 8 ° C. or lower, An aqueous complex solution was prepared. Separately, after adding 739 g of erythorbic acid (1.5 mol with respect to 1 mol of silver) and 3,530 g of pure water as a reducing agent to a 20 L plastic container, mixing and stirring while cooling to 9 ° C. or lower, A reducing agent-containing aqueous solution was prepared.
  • the reducing agent-containing aqueous solution was added to the silver salt complex aqueous solution with stirring while cooling the reaction system to 10 ° C. or less (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using a filter paper, and then washed and filtered using pure water until the conductivity of the filtrate reached 15 ⁇ S / cm.
  • the obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours.
  • 4.2 g of a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) dispersed in a methanol solution was added to 300 g of the obtained silver fine particles (1 per silver fine particle). 4% by weight) and after stirring and mixing for 90 minutes, the methanol was distilled off.
  • the fine particles of Example 4-6 were obtained by pulverization with a jet pulverizer.
  • Examples 4-7 to 4-9 and Comparative Examples 4-3 to 4-4> Silver fine particles were obtained by variously changing the production conditions of the silver fine particles.
  • Example 4-10 Production of silver fine particles> After adding 160 g of silver nitrate and 800 mL of methanol to a 2 L beaker, 151.6 g of n-butylamine was added while cooling in a water bath, and then mixed and stirred while cooling to 18 ° C. or lower to prepare solution A. . Separately, 248.8 g of erythorbic acid was weighed into a 5 L beaker, dissolved by adding 1600 mL of water and stirred, and then mixed and stirred while cooling to 18 ° C. or lower by adding 800 mL of methanol to prepare solution B. .
  • the liquid B was stirred and the reaction system was cooled to 20 ° C. or lower, and the liquid A was added dropwise to the liquid B over 1 hour and 20 minutes. After the completion of dropping, the mixture was stirred for 14 hours and then allowed to stand for 30 minutes to precipitate a solid. After removing the supernatant liquid by decantation, suction filtration was performed using a filter paper, followed by washing and filtration using methanol and pure water.
  • the obtained silver fine particles were dried in a vacuum dryer for 30 minutes for 6 hours, and then the polymer compound “DISPERBYK-106” (trade name: dispersed in a methanol solution with respect to 24 g of the obtained silver fine particles). 0.48 g (manufactured by Big Chemie Japan Co., Ltd.) was added (2.0% by weight based on silver fine particles), and after stirring and mixing for 90 minutes, methanol was distilled off. Next, after drying at 25 ° C. for 6 hours in a vacuum dryer, the fine particles of Example 4-10 were obtained by pulverization with a jet pulverizer.
  • Table 7 shows the production conditions at this time, and Table 9 shows the characteristics of the obtained silver fine particles.
  • Table 10 shows the production conditions and various characteristics of the obtained conductive coating film.
  • the silver fine particles according to the present invention have a crystallite diameter ratio [crystallite diameter D X (111) / crystallite diameter D X (200)] of 1.40 and Miller index (111) by X-ray diffraction of 1.40. Because of the above, it is suitable as a raw material for conductive paste and the like that can be fired at a low temperature.

Abstract

Provided are: fine silver particles suitable as a starting material for, e.g., a conductive paste which can be baked at a low temperature; a conductive paste containing said fine silver particles; a conductive film; and an electronic device. The fine silver particles according to the present invention are characterized by showing a ratio of the crystalline diameter at a Miller index in X-ray diffractometry of (111) to the crystalline diameter at a Miller index in X-ray diffractometry of (200) [crystalline diameter DX (111)/crystalline diameter DX (200)] of 1.40 or greater.

Description

銀微粒子並びに該銀微粒子を含有する導電性ペースト、導電性膜及び電子デバイスSilver fine particles, and conductive paste, conductive film and electronic device containing the silver fine particles
　本発明は、低温焼成が可能な導電性ペーストの原料用として好適な、平均粒子径１００ｎｍ以上又は平均粒子径１００ｎｍ未満の銀微粒子並びに該銀微粒子を含有する導電性ペースト、導電性膜及び電子デバイスに関する。 The present invention relates to a silver fine particle having an average particle size of 100 nm or more or an average particle size of less than 100 nm, and a conductive paste, a conductive film and an electronic device containing the silver fine particle, which are suitable for use as a raw material for a conductive paste capable of low-temperature firing. About.
　電子デバイスの電極や回路パターンの形成は、金属粒子を含む導電性ペーストを用いて基板上に電極や回路パターンを印刷した後、加熱焼成して導電性ペーストに含まれる金属粒子を焼結させることにより行われており、加熱焼成温度により焼成型ペーストとポリマー型ペーストに分類される。近年、その加熱焼成温度は低温化する傾向にある。 The electrodes and circuit patterns of electronic devices are formed by printing electrodes and circuit patterns on a substrate using a conductive paste containing metal particles, and then baking by heating and sintering the metal particles contained in the conductive paste. And is classified into a firing paste and a polymer paste according to the heating and firing temperature. In recent years, the heating and firing temperature tends to be lowered.
　焼成型ペーストは、一般にセラミック基板に利用されており、金属粒子とガラスフリット、溶剤等を主成分としたものであり、その加熱焼成温度は約５００℃以上である。一方、ポリマー型ペーストは、メンブレン配線板や導電性接着剤等に使用されており、金属粒子が樹脂、硬化剤、有機溶剤、分散剤等に分散されたペーストからなり、該導電性ペーストをスクリーン印刷などにより基板上に所定の導体パターンを形成し、２５０℃程度までの温度で加熱焼成して用いられる。 The fired paste is generally used for ceramic substrates, and is mainly composed of metal particles, glass frit, a solvent and the like, and the heating and firing temperature thereof is about 500 ° C. or higher. On the other hand, polymer type paste is used for membrane wiring boards, conductive adhesives, etc., and consists of a paste in which metal particles are dispersed in a resin, a curing agent, an organic solvent, a dispersing agent, etc. A predetermined conductor pattern is formed on a substrate by printing or the like, and is heated and fired at a temperature up to about 250 ° C. for use.
　上記金属粒子としては、銅粉並びに銀粉が用いられており、殊に、メンブレン配線板の回路形成に用いるスクリーン印刷用導電ペーストには、導電粒子として銀が用いられている。銀はマイグレーションを起こしやすいという欠点はあるが、同程度の比抵抗を有する銅に比べて酸化し難いために取り扱いやすく、広く利用されている。 As the metal particles, copper powder and silver powder are used. In particular, silver is used as the conductive particles in the conductive paste for screen printing used for forming the circuit of the membrane wiring board. Silver has a drawback that it tends to cause migration, but it is difficult to oxidize compared to copper having the same specific resistance, so it is easy to handle and is widely used.
　近年、導電性ペーストの加熱焼成温度は低温化する傾向にある。例えば、電子デバイスの実装基板としては、一般に、３００℃程度までの加熱が可能であり、耐熱性に優れているためポリイミド製フレキシブル基板が用いられているが、高価であるため、最近では、より安価なＰＥＴ（ポリエチレンテレフタレート）基板やＰＥＮ（ポリエチレンナフタレート）基板が代替材料として検討されている。しかしながら、ＰＥＴ基板やＰＥＮ基板はポリイミド製フレキシブル基板と比較して耐熱性が低く、殊に、メンブレン配線板に用いられるＰＥＴフィルム基板は加熱焼成を１５０℃以下で行う必要がある。 In recent years, the heating and firing temperature of conductive paste has been decreasing. For example, as a mounting substrate for an electronic device, a polyimide flexible substrate is generally used because it can be heated up to about 300 ° C. and has excellent heat resistance. Inexpensive PET (polyethylene terephthalate) substrates and PEN (polyethylene naphthalate) substrates are being investigated as alternative materials. However, PET substrates and PEN substrates have lower heat resistance than polyimide flexible substrates, and in particular, PET film substrates used for membrane wiring boards need to be heated and fired at 150 ° C. or lower.
　また、加熱焼成を２００℃より更に低い温度で行うことができれば、ポリカーボネートや紙等の基板への電極や回路パターンの形成も可能となり、各種電極材等の用途が広がることが期待される。 Also, if heating and firing can be performed at a temperature lower than 200 ° C., it becomes possible to form electrodes and circuit patterns on a substrate such as polycarbonate and paper, and it is expected that the use of various electrode materials will be expanded.
　このような低温焼成が可能な導電性ペーストの原料となる金属粒子として、ナノメートルオーダーの銀微粒子が期待されている。その理由として、金属粒子の大きさがナノメートルオーダーになると表面活性が高くなり、融点が金属のバルクのものよりもはるかに低下するため、低い温度で焼結させることが可能になるためである。 As a metal particle that is a raw material for such a conductive paste that can be fired at a low temperature, silver fine particles of nanometer order are expected. The reason for this is that when the size of the metal particles is on the order of nanometers, the surface activity becomes high and the melting point is much lower than that of the bulk metal, so that it can be sintered at a low temperature. .
　また、ナノメートルオーダーの銀微粒子は低温で焼結が可能であると共に、一度焼結すると耐熱性が維持されるという、従来のはんだにはない性質を利用した鉛フリーのはんだ代替材料としても期待されている。 In addition, nanometer-order silver fine particles can be sintered at low temperatures, and heat resistance is maintained once sintered, which is also expected as a lead-free solder replacement material using a property not found in conventional solder. Has been.
　これまでに、電子デバイスの配線材料や電極材料となる銀微粒子として、さらに、低温焼成が可能な銀微粒子として、サブミクロンからミクロンサイズの銀微粒子が提案されており、ＢＥＴ比表面積に対する結晶子径の比を限定した球状銀粉（特許文献１）、平均粒子径、結晶子径及び結晶子径に対する平均粒子径の比を限定した銀微粒子（特許文献２）、タップ密度、レーザー回折法平均粒径及び比表面積を限定した銀粉（特許文献３）、一次粒子の平均粒径０．０５～１．０μｍ、結晶子径２０～１５０ｎｍの銀微粒子の製造方法（特許文献４）、平均粒径が０．１μｍ以上、１μｍ未満であり、粒度分布がシャープでかつ高分散性である球状銀粉（特許文献５）、一次粒子径が０．０７～４．５μｍ、結晶子径が２０ｎｍ以上である高結晶銀粉（特許文献６）、銀反応工程における温度範囲を限定した、一次粒子径が１～１００ｎｍの範囲にある微小銀粒子含有組成物（特許文献７）等が知られている。 So far, silver fine particles of submicron to micron size have been proposed as silver fine particles that can be used for wiring materials and electrode materials of electronic devices, and silver fine particles that can be fired at low temperature. Spherical silver powder with limited ratio (Patent Document 1), average particle diameter, crystallite diameter and silver fine particles with limited ratio of average particle diameter to crystallite diameter (Patent Document 2), tap density, laser diffraction method average particle diameter And silver powder with a specific surface area limited (Patent Document 3), a method for producing silver fine particles having an average primary particle diameter of 0.05 to 1.0 μm and a crystallite diameter of 20 to 150 nm (Patent Document 4), and an average particle diameter of 0 .1 μm or more and less than 1 μm, spherical silver powder having a sharp particle size distribution and high dispersibility (Patent Document 5), primary particle size of 0.07 to 4.5 μm, crystallite size of 20 nm or more Crystal silver powder (Patent Document 6), with limited temperature range in silver reaction step, fine silver particle-containing composition (Patent Document 7) are known in which the primary particle diameter in the range of 1 ~ 100 nm.
特開２００５－３３０５２９号公報JP 2005-330529 A 特開２００６－１８３０７２号公報JP 2006-183072 A 特開２００７－１３１９５０号公報JP 2007-131950 A 特開２００８－３１５２６号公報JP 2008-31526 A 特開２０１０－７０７９３号公報JP 2010-70793 A 特開２００７－１６２５８号公報JP 2007-16258 A 特開２００９－１２０９４９号公報JP 2009-120949 A
　前出特許文献１から特許文献６に開示されている銀微粒子は、いずれも平均粒子径及び結晶子径、ＢＥＴ比表面積値等が限定されてはいるが、Ｘ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］については考慮されておらず、後出比較例に示す通り、上記結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０未満の場合には、良好な低温焼結性を有する銀微粒子を得ることが困難となる。また、結晶子径ＤＸ（１１１）が２０ｎｍを超える場合には、銀微粒子の結晶子径が大きいため銀微粒子内部の反応性としては低いものとなり、低温焼結には不利となる。 The silver fine particles disclosed in Patent Document 1 to Patent Document 6 are all limited in average particle diameter, crystallite diameter, BET specific surface area value, etc., but the Miller index (111) by X-ray diffraction is limited. And the ratio of the crystallite diameter in (200) [crystallite diameter D X (111) / crystallite diameter D X (200)] is not taken into consideration. When X (111) / crystallite diameter D X (200)] is less than 1.40, it is difficult to obtain silver fine particles having good low-temperature sinterability. On the other hand, when the crystallite diameter D X (111) exceeds 20 nm, the crystallite diameter of the silver fine particles is large, so that the reactivity inside the silver fine particles is low, which is disadvantageous for low-temperature sintering.
　そこで、本発明は、低温焼成が可能な導電性ペーストの原料用として好適な銀微粒子を提供することを技術的課題とする。また、得られる銀微粒子の平均粒径は広範囲であり、特に好ましくは３０ｎｍ以上１００ｎｍ未満および１００ｎｍ以上１μｍ未満の銀微粒子を得ることを目的とする。 Therefore, a technical problem of the present invention is to provide silver fine particles suitable as a raw material for conductive paste that can be fired at a low temperature. Further, the average particle diameter of the obtained silver fine particles is in a wide range, and it is particularly desirable to obtain silver fine particles of 30 nm or more and less than 100 nm and 100 nm or more and less than 1 μm.
　前記技術的課題は、次の通りの本発明によって達成できる。 The technical problem can be achieved by the present invention as follows.
　即ち、本発明は、Ｘ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０以上であることを特徴とする銀微粒子である（本発明１）。 That is, according to the present invention, the ratio of the crystallite diameter in the Miller indices (111) and (200) by X-ray diffraction [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40 or more. Silver fine particles characterized by the present invention (Invention 1).
　また、本発明は、平均粒子径（ＤＳＥＭ）が１００ｎｍ以上１μｍ未満である本発明１記載の銀微粒子である（本発明２）。 Moreover, this invention is a silver fine particle of this invention 1 whose average particle diameter ( DSEM ) is 100 nm or more and less than 1 micrometer (invention 2).
　また、本発明は、ミラー指数（１１１）における結晶子径ＤＸ（１１１）が２０ｎｍ以下である本発明１又は２記載の銀微粒子である（本発明３）。 Further, the present invention is the silver fine particle according to the first or second aspect of the present invention, wherein the crystallite diameter D X (111) at the Miller index (111) is 20 nm or less (Invention 3).
　また、本発明はミラー指数（２００）における結晶子径ＤＸ（２００）が１４ｎｍ以下である本発明１～３の何れかに記載の銀微粒子である（本発明４）。 Further, the present invention is the silver fine particles according to any one of the present inventions 1 to 3, wherein the crystallite diameter D X (200) at the Miller index (200) is 14 nm or less (Invention 4).
　また、本発明は、銀微粒子の粒子表面が数平均分子量１，０００以上の高分子系分散剤から選ばれる１種又は２種以上で被覆されている本発明１～４の何れかに記載の銀微粒子である（本発明５）。 Further, the present invention is the invention according to any one of the present inventions 1 to 4, wherein the particle surface of the silver fine particles is coated with one or more kinds selected from polymer dispersants having a number average molecular weight of 1,000 or more. Silver fine particles (Invention 5).
　また、本発明は、平均粒子径（ＤＳＥＭ）が３０ｎｍ以上１００ｎｍ未満である本発明１記載の銀微粒子である（本発明６）。 Moreover, this invention is a silver fine particle of this invention 1 whose average particle diameter (D SEM ) is 30 nm or more and less than 100 nm (this invention 6).
　また、本発明は、ミラー指数（１１１）における結晶子径ＤＸ（１１１）が２５ｎｍ以下である本発明１又は６記載の銀微粒子である（本発明７）。 Further, the present invention is the silver fine particles according to the first or sixth aspect of the present invention, wherein the crystallite diameter D X (111) at the Miller index (111) is 25 nm or less (Invention 7).
　また、本発明は、ミラー指数（２００）における結晶子径ＤＸ（２００）が１５ｎｍ以下である本発明１、６、７の何れかに記載の銀微粒子である（本発明８）。 Further, the present invention is the silver fine particles according to any one of the present inventions 1, 6, and 7 having a crystallite diameter D X (200) of Miller index (200) of 15 nm or less (Invention 8).
　また、本発明は、銀微粒子の粒子表面が分子量１０，０００以上の高分子化合物で被覆されている請求項１、６～８の何れかに記載の銀微粒子である（本発明９）。 The present invention is the silver fine particles according to any one of claims 1 and 6 to 8, wherein the surface of the silver fine particles is coated with a polymer compound having a molecular weight of 10,000 or more (Invention 9).
　また、本発明は、請求項１～９の何れかに記載の銀微粒子を含む導電性ペーストである（本発明１０）。 Further, the present invention is a conductive paste containing the silver fine particles according to any one of claims 1 to 9 (present invention 10).
　また、本発明は、請求項１０記載の導電性ペーストを用いて形成された導電性膜である（本発明１１）。 Further, the present invention is a conductive film formed using the conductive paste according to claim 10 (Invention 11).
　また、本発明は、請求項１１記載の導電性膜を有する電子デバイス（本発明１１）。 The present invention also provides an electronic device having the conductive film according to claim 11 (present invention 11).
　本発明に係る銀微粒子は、Ｘ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０以上であることから、低温焼成が可能な導電性ペースト等の原料として好適である。 The silver fine particles according to the present invention have a crystallite diameter ratio [crystallite diameter D X (111) / crystallite diameter D X (200)] of 1.40 and Miller index (111) by X-ray diffraction of 1.40. Because of the above, it is suitable as a raw material for conductive paste and the like that can be fired at a low temperature.
　本発明の構成をより詳しく説明すれば、次の通りである。 The configuration of the present invention will be described in more detail as follows.
　まず、本発明に係る銀微粒子について述べる。 First, the silver fine particles according to the present invention will be described.
　本発明に係る銀微粒子は、Ｘ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０以上であることを特徴とする銀微粒子である。 The silver fine particles according to the present invention have a crystallite diameter ratio [crystallite diameter D X (111) / crystallite diameter D X (200)] of 1.40 and Miller index (111) by X-ray diffraction of 1.40. Silver fine particles characterized by the above.
　本発明の銀微粒子の平均粒径は、用途において必要とされる条件により広範囲に決定することが出来るが、製造方法の観点から、平均粒子径（ＤＳＥＭ）が１００ｎｍ以上（第１の態様）と平均粒子径（ＤＳＥＭ）が１００ｎｍ未満（第２の態様）との場合に分類することが出来る。 The average particle size of the silver fine particles of the present invention can be determined over a wide range depending on the conditions required for the application. From the viewpoint of the production method, the average particle size (D SEM ) is 100 nm or more (first embodiment). And an average particle diameter (D SEM ) of less than 100 nm (second embodiment).
　先ず、上記第１の態様について説明する。第１の態様において、本発明に係る銀微粒子の平均粒子径（ＤＳＥＭ）は１００ｎｍ以上であり、好ましくは１００ｎｍ以上１μｍ未満、より好ましくは１００～５００ｎｍである。平均粒子径（ＤＳＥＭ）が上記範囲にあることにより、配線及び電極のファイン化への対応が容易となる。平均粒子径（ＤＳＥＭ）が１００ｎｍ未満の場合には、常温においても焼結が生じやすく、また、導電ペースト中における分散性及び分散安定性が低下する傾向にあるため、第２の態様に記載するような処方が必要となる場合がある。平均粒子径（ＤＳＥＭ）が１μｍを超える場合には、低温での焼結性が低下するため好ましくない。また、粒子サイズが大きすぎるため、これを用いて得られる電子デバイスのファイン化が困難となる。 First, the first aspect will be described. In the first embodiment, the average particle size (D SEM ) of the silver fine particles according to the present invention is 100 nm or more, preferably 100 nm or more and less than 1 μm, more preferably 100 to 500 nm. When the average particle diameter (D SEM ) is in the above range, it is easy to cope with finer wiring and electrodes. When the average particle size (D SEM ) is less than 100 nm, sintering is likely to occur even at room temperature, and the dispersibility and dispersion stability in the conductive paste tend to be reduced. Prescribing may be required. When the average particle diameter (D SEM ) exceeds 1 μm, the sinterability at low temperatures is lowered, which is not preferable. In addition, since the particle size is too large, it is difficult to refine an electronic device obtained using the particle size.
　本発明の第１の態様に係る銀微粒子のＸ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］は１．４０以上であり、好ましくは１．４４以上、より好ましくは１．４８以上である。結晶子径ＤＸ（１１１）と結晶子径ＤＸ（２００）の比が１．４０以上とすることにより、低温焼結性の優れた銀微粒子を得ることができる。 Ratio of crystallite diameter in Miller index (111) and (200) by X-ray diffraction of silver fine particles according to the first aspect of the present invention [crystallite diameter D X (111) / crystallite diameter D X (200)] Is 1.40 or more, preferably 1.44 or more, more preferably 1.48 or more. When the ratio of the crystallite diameter D X (111) to the crystallite diameter D X (200) is 1.40 or more, silver fine particles having excellent low-temperature sinterability can be obtained.
　本発明の第１の態様に係る銀微粒子のＸ線回折によるミラー指数（１１１）における結晶子径ＤＸ（１１１）は２０ｎｍ以下であることが好ましく、より好ましくは１０～１９ｎｍ、更により好ましくは１０～１８ｎｍである。結晶子径ＤＸ（１１１）が２０ｎｍを超える場合には、銀微粒子中の反応性が低下し、低温焼結性が損なわれてしまうため好ましくない。また、結晶子径ＤＸ（１１１）が１０ｎｍ未満の場合には、銀微粒子が不安定となり、常温においても部分的に焼結・融着が生じ始めるため好ましくない。 The crystallite diameter D X (111) in the Miller index (111) by X-ray diffraction of the silver fine particles according to the first aspect of the present invention is preferably 20 nm or less, more preferably 10 to 19 nm, still more preferably. 10 to 18 nm. When the crystallite diameter D X (111) exceeds 20 nm, the reactivity in the silver fine particles is lowered, and the low-temperature sinterability is impaired. In addition, when the crystallite diameter D X (111) is less than 10 nm, the silver fine particles become unstable and partial sintering and fusion start even at room temperature, which is not preferable.
　本発明の第１の態様に係る銀微粒子のＸ線回折によるミラー指数（２００）における結晶子径ＤＸ（２００）は１４ｎｍ以下であることが好ましく、より好ましくは１３ｎｍ以下、更により好ましくは１２ｎｍ以下である。結晶子径ＤＸ（２００）は、［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］を１．４０以上とするために、小さい方が好ましい。 The crystallite diameter D X (200) in the Miller index (200) by X-ray diffraction of the silver fine particles according to the first aspect of the present invention is preferably 14 nm or less, more preferably 13 nm or less, still more preferably 12 nm. It is as follows. The crystallite diameter D X (200) is preferably smaller so that [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40 or more.
　本発明の第１の態様に係る銀微粒子の低温焼結性は、後述する加熱による結晶子径の変化率［（１５０℃で３０分間加熱後の銀微粒子の結晶子径／加熱前の銀微粒子の結晶子径）×１００］によって評価を行い、１５０℃の加熱による結晶子径の変化率が１２０％以上であることが好ましく、より好ましくは１２５％以上である。結晶子径の変化率が１２０％未満の場合には、低温焼結性が優れているとは言いがたい。本発明においては、２１０℃で３０分間加熱した場合、結晶子径の変化率は１５０％以上であることが好ましく、より好ましくは１７０％以上である。 The low-temperature sinterability of the silver fine particles according to the first aspect of the present invention is the change rate of the crystallite diameter by heating described later [(crystallite diameter of silver fine particles after heating at 150 ° C. for 30 minutes / silver fine particles before heating Crystallite diameter) × 100], and the change rate of the crystallite diameter by heating at 150 ° C. is preferably 120% or more, more preferably 125% or more. When the change rate of the crystallite diameter is less than 120%, it cannot be said that the low-temperature sinterability is excellent. In the present invention, when heated at 210 ° C. for 30 minutes, the change rate of the crystallite diameter is preferably 150% or more, and more preferably 170% or more.
　本発明の第１の態様に係る銀微粒子のＢＥＴ比表面積値は、５ｍ２／ｇ以下であることが好ましい。ＢＥＴ比表面積値が５ｍ２／ｇを超える場合、これを用いて得られる導電性ペーストの粘度が高くなるため好ましくない。 The BET specific surface area value of the silver fine particles according to the first aspect of the present invention is preferably 5 m 2 / g or less. When the BET specific surface area value exceeds 5 m 2 / g, the viscosity of the conductive paste obtained by using this is not preferable.
　本発明の第２の態様に係る銀微粒子の平均粒子径（ＤＳＥＭ）は１００ｎｍ未満であり、好ましくは３０ｎｍ以上１００ｎｍ未満、より好ましくは３５ｎｍ以上１００ｎｍ未満である。平均粒子径（ＤＳＥＭ）が上記範囲にあることにより、これを用いて得られる電子デバイスのファイン化が容易となる。平均粒子径（ＤＳＥＭ）が３０ｎｍ未満の場合には、銀微粒子の持つ表面活性が高くなり、その微細な粒子径を安定に維持するために多量の有機物等を付着させる必要があるため好ましくない。 The average particle diameter (D SEM ) of the silver fine particles according to the second aspect of the present invention is less than 100 nm, preferably 30 nm or more and less than 100 nm, more preferably 35 nm or more and less than 100 nm. When the average particle diameter (D SEM ) is in the above range, it is easy to refine an electronic device obtained using the average particle diameter (D SEM ). When the average particle size (D SEM ) is less than 30 nm, the surface activity of the silver fine particles increases, and it is not preferable because a large amount of organic matter or the like needs to be adhered in order to stably maintain the fine particle size. .
　本発明の第２の態様に係る銀微粒子のＸ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］は１．４０以上であり、好ましくは１．４４以上、より好ましくは１．４８以上である。結晶子径ＤＸ（１１１）と結晶子径ＤＸ（２００）の比が１．４０以上とすることにより、低温焼結性の優れた銀微粒子を得ることができる。 Ratio of crystallite diameter in Miller index (111) and (200) by X-ray diffraction of silver fine particles according to the second aspect of the present invention [crystallite diameter D X (111) / crystallite diameter D X (200)] Is 1.40 or more, preferably 1.44 or more, more preferably 1.48 or more. When the ratio of the crystallite diameter D X (111) to the crystallite diameter D X (200) is 1.40 or more, silver fine particles having excellent low-temperature sinterability can be obtained.
　本発明の第２の態様に係る銀微粒子のＸ線回折によるミラー指数（１１１）における結晶子径ＤＸ（１１１）は２５ｎｍ以下であることが好ましく、より好ましくは２３～１０ｎｍ、更により好ましくは２０～１０ｎｍである。結晶子径ＤＸ（１１１）が２５ｎｍを超える場合には、銀微粒子中の反応性が低下し、低温焼結性が損なわれてしまうため好ましくない。また、結晶子径ＤＸ（１１１）が１０ｎｍ未満の場合には、銀微粒子が不安定となり、常温においても部分的に焼結・融着が生じ始めるため好ましくない。 The crystallite diameter D X (111) in the Miller index (111) by X-ray diffraction of the silver fine particles according to the second aspect of the present invention is preferably 25 nm or less, more preferably 23 to 10 nm, still more preferably 20 to 10 nm. When the crystallite diameter D X (111) exceeds 25 nm, the reactivity in the silver fine particles is lowered, and the low-temperature sinterability is impaired. In addition, when the crystallite diameter D X (111) is less than 10 nm, the silver fine particles become unstable and partial sintering and fusion start even at room temperature, which is not preferable.
　本発明の第２の態様に係る銀微粒子のＸ線回折によるミラー指数（２００）における結晶子径ＤＸ（２００）は１５ｎｍ以下であることが好ましく、より好ましくは１４ｎｍ以下、更により好ましくは１３ｎｍ以下である。結晶子径ＤＸ（２００）は、［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］を１．４０以上とするために、小さい方が好ましい。 The crystallite diameter D X (200) in the Miller index (200) by X-ray diffraction of the silver fine particles according to the second aspect of the present invention is preferably 15 nm or less, more preferably 14 nm or less, still more preferably 13 nm. It is as follows. The crystallite diameter D X (200) is preferably smaller so that [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40 or more.
　本発明の第２の態様に係る銀微粒子の低温焼結性は、後述する加熱による結晶子径の変化率[（１５０℃で３０分間加熱後の銀微粒子の結晶子径／加熱前の銀微粒子の結晶子径）×１００]によって評価を行い、１５０℃の加熱による結晶子径の変化率が１５０％以上であることが好ましく、より好ましくは１６０％以上である。結晶子径の変化率が１５０％未満の場合には、低温焼結性が優れているとは言いがたい。本発明においては、２１０℃で３０分間加熱した場合、結晶子径の変化率は１８０％以上であることが好ましく、より好ましくは２００％以上である。 The low-temperature sinterability of the silver fine particles according to the second aspect of the present invention is the change rate of crystallite diameter by heating described later [(crystallite diameter of silver fine particles after heating at 150 ° C. for 30 minutes / silver fine particles before heating (Crystallite diameter) × 100], and the change rate of the crystallite diameter by heating at 150 ° C. is preferably 150% or more, more preferably 160% or more. When the change rate of the crystallite diameter is less than 150%, it cannot be said that the low-temperature sinterability is excellent. In the present invention, when heated at 210 ° C. for 30 minutes, the change rate of the crystallite diameter is preferably 180% or more, and more preferably 200% or more.
　本発明の第２の態様に係る銀微粒子のＢＥＴ比表面積値は、１０ｍ２／ｇ以下であることが好ましく、より好ましくは８ｍ２／ｇ以下である。ＢＥＴ比表面積値が１０ｍ２／ｇを超える場合、これを用いて得られる導電性ペーストの粘度が高くなるため好ましくない。 The BET specific surface area value of the silver fine particles according to the second aspect of the present invention is preferably 10 m 2 / g or less, more preferably 8 m 2 / g or less. When the BET specific surface area value exceeds 10 m 2 / g, the viscosity of the conductive paste obtained by using this is not preferable.
　本発明の第１及び第２の態様に係る銀微粒子の粒子形状は、球状もしくは粒状が好ましい。 The particle shape of the silver fine particles according to the first and second aspects of the present invention is preferably spherical or granular.
　本発明の銀微粒子は、高分子系分散剤から選ばれる１種又は２種以上で被覆されていることが好ましい。本発明の第１の態様の銀微粒子および第２の態様の銀微粒子において、高分子系分散剤は、数平均分子量によって使い分けることが好ましい。 The silver fine particles of the present invention are preferably coated with one or more selected from polymer dispersants. In the silver fine particles according to the first aspect of the present invention and the silver fine particles according to the second aspect, it is preferable that the polymer dispersant is properly used depending on the number average molecular weight.
　本発明の第１の態様に係る銀微粒子は、銀微粒子の粒子表面が数平均分子量１，０００以上の高分子系分散剤から選ばれる１種又は２種以上で被覆されていることが好ましい。分散剤の数平均分子量は１，０００以上であることが好ましく、より好ましくは１，０００～１５０，０００、更により好ましくは５，０００～１００，０００である。数平均分子量が１，０００未満の分散剤を表面処理した銀微粒子粉末は、分散剤を処理した効果が不十分であり、その後の粉砕処理において、銀微粒子が凝集する傾向がある。一方、数平均分子量が１５０，０００を超える場合には分散剤の粘度が高くなり、銀微粒子表面への均一な処理が困難となる。 In the silver fine particles according to the first aspect of the present invention, the particle surface of the silver fine particles is preferably coated with one or more selected from polymer dispersing agents having a number average molecular weight of 1,000 or more. The number average molecular weight of the dispersant is preferably 1,000 or more, more preferably 1,000 to 150,000, and still more preferably 5,000 to 100,000. The silver fine particle powder obtained by surface-treating a dispersant having a number average molecular weight of less than 1,000 has an insufficient effect of treating the dispersant, and silver fine particles tend to aggregate in the subsequent pulverization treatment. On the other hand, when the number average molecular weight exceeds 150,000, the viscosity of the dispersant becomes high, and it becomes difficult to uniformly treat the surface of the silver fine particles.
　本発明の第２の態様に係る銀微粒子は、銀微粒子の粒子表面が分子量１０，０００以上の高分子化合物（高分子系分散剤）で被覆されていることが好ましい。分子量が１０，０００未満の場合、その後に行う粉砕処理において凝集塊が生じ、得られた銀微粒子は導電ペースト中での分散性が困難になるため好ましくない。また、高分子系分散剤の分子量の上限は、１００，０００程度であり、これ以上分子量が高くなると粘度が高くなり、銀微粒子表面への均一な処理が困難となる。 In the silver fine particles according to the second aspect of the present invention, the surface of the silver fine particles is preferably coated with a polymer compound (polymer dispersing agent) having a molecular weight of 10,000 or more. When the molecular weight is less than 10,000, agglomerates are produced in the subsequent pulverization treatment, and the resulting silver fine particles are not preferable because dispersibility in the conductive paste becomes difficult. In addition, the upper limit of the molecular weight of the polymeric dispersant is about 100,000. If the molecular weight is higher than this, the viscosity increases, and uniform processing on the surface of the silver fine particles becomes difficult.
　上記の何れの分子量の高分子系分散剤を用いる場合において、銀微粒子表面への高分子化合物の処理の均一性及び処理効果を考慮すれば、分散剤として、酸価とアミン価の両方を有する（酸性官能基と塩基性官能基の両方の官能基を有する）分散剤もしくは、酸価を有する分散剤とアミン価を有する分散剤とを併用することが好ましい。 In the case of using any of the above-described molecular dispersants having a molecular weight, considering the uniformity of the treatment of the polymer compound on the surface of the silver fine particles and the treatment effect, the dispersant has both an acid value and an amine value. It is preferable to use a dispersant (having both an acidic functional group and a basic functional group) or a dispersant having an acid value and a dispersant having an amine value in combination.
　分散剤の被覆量は、銀微粒子のＢＥＴ表面積値にもよるが、銀微粒子粉末に対して０．１～３．０重量％が好ましく、より好ましくは０．２～２．５重量％である。０．１重量％未満の場合には、分散剤の処理量が不十分であり、その後の粉砕処理において、銀微粒子粉末が凝集する傾向がある。３．０重量％を超える場合には、銀微粒子粉末の凝集を抑制することはできるが、導電性に関与しない有機物成分が増えるため好ましくない。 The coating amount of the dispersant is preferably 0.1 to 3.0% by weight, more preferably 0.2 to 2.5% by weight based on the silver fine particle powder, although it depends on the BET surface area value of the silver fine particles. . When the amount is less than 0.1% by weight, the amount of the dispersant is insufficient, and the silver fine particle powder tends to aggregate in the subsequent pulverization treatment. When the amount exceeds 3.0% by weight, aggregation of the silver fine particle powder can be suppressed, but an organic component not involved in conductivity increases, which is not preferable.
　前記高分子系分散剤としては、一般に顔料分散剤として市販されているものを使用することができ、具体的には、ＡＮＴＩ－ＴＥＲＲＡ－Ｕ、ＡＮＴＩ－ＴＥＲＲＡ－２０５、ＤＩＳＰＥＲＢＹＫ－１０１、ＤＩＳＰＥＲＢＹＫ－１０２、ＤＩＳＰＥＲＢＹＫ－１０６、ＤＩＳＰＥＲＢＹＫ－１０８、ＤＩＳＰＥＲＢＹＫ－１０９、ＤＩＳＰＥＲＢＹＫ－１１０、ＤＩＳＰＥＲＢＹＫ－１１１、ＤＩＳＰＥＲＢＹＫ－１１２、ＤＩＳＰＥＲＢＹＫ－１１６、ＤＩＳＰＥＲＢＹＫ－１３０、ＤＩＳＰＥＲＢＹＫ－１４０、ＤＩＳＰＥＲＢＹＫ－１４２、ＤＩＳＰＥＲＢＹＫ－１４５、ＤＩＳＰＥＲＢＹＫ－１６１、ＤＩＳＰＥＲＢＹＫ－１６２、ＤＩＳＰＥＲＢＹＫ－１６３、ＤＩＳＰＥＲＢＹＫ－１６４、ＤＩＳＰＥＲＢＹＫ－１６６、ＤＩＳＰＥＲＢＹＫ－１６７、ＤＩＳＰＥＲＢＹＫ－１６８、ＤＩＳＰＥＲＢＹＫ－１７０、ＤＩＳＰＥＲＢＹＫ－１７１、ＤＩＳＰＥＲＢＹＫ－１７４、ＤＩＳＰＥＲＢＹＫ－１８０、ＤＩＳＰＥＲＢＹＫ－１８２、ＤＩＳＰＥＲＢＹＫ－１８３、ＤＩＳＰＥＲＢＹＫ－１８４、ＤＩＳＰＥＲＢＹＫ－１８５、ＤＩＳＰＥＲＢＹＫ－２０００、ＤＩＳＰＥＲＢＹＫ－２００１、ＤＩＳＰＥＲＢＹＫ－２００８、ＤＩＳＰＥＲＢＹＫ－２００９、ＤＩＳＰＥＲＢＹＫ－２０２２、ＤＩＳＰＥＲＢＹＫ－２０２５、ＤＩＳＰＥＲＢＹＫ－２０５０、ＤＩＳＰＥＲＢＹＫ－２０７０、ＤＩＳＰＥＲＢＹＫ－２０９６、ＤＩＳＰＥＲＢＹＫ－２１５０、ＤＩＳＰＥＲＢＹＫ－２１５５、ＤＩＳＰＥＲＢＹＫ－２１６３、ＤＩＳＰＥＲＢＹＫ－２１６４、ＢＹＫ－Ｐ１０４、ＢＹＫ－Ｐ１０４Ｓ、ＢＹＫ－Ｐ１０５、ＢＹＫ－９０７６、ＢＹＫ－９０７７、ＢＹＫ－２２０Ｓ、（ビックケミー・ジャパン株式会社製）；ＥＦＫＡ　４００８、ＥＦＫＡ　４００９、ＥＦＫＡ　４０４６、ＥＦＫＡ　４０４７、ＥＦＫＡ　４０１０、ＥＦＫＡ　４０１５、ＥＦＫＡ　４０２０、ＥＦＫＡ　４０５０、ＥＦＫＡ　４０５５、ＥＦＫＡ　４０６０、ＥＦＫＡ　４０８０、ＥＦＫＡ　４３００、ＥＦＫＡ　４３３０、ＥＦＫＡ　４４００、ＥＦＫＡ　４４０１、ＥＦＫＡ　４４０２、ＥＦＫＡ　４４０３、ＥＦＫＡ　４４０６、ＥＦＫＡ　４８００、ＥＦＫＡ　５０１０、ＥＦＫＡ　５０４４、ＥＦＫＡ　５２４４、ＥＦＫＡ　５０５４、ＥＦＫＡ　５０５５、ＥＦＫＡ　５０６３、ＥＦＫＡ　５０６４、ＥＦＫＡ　５０６５、ＥＦＫＡ　５０６６、ＥＦＫＡ　５０７０（ＢＡＳＦジャパン株式会社製）；ＳＯＬＳＰＥＲＳＥ　３０００、ＳＯＬＳＰＥＲＳＥ　１３２４０、ＳＯＬＳＰＥＲＳＥ　１３９４０、ＳＯＬＳＰＥＲＳＥ　１６０００、ＳＯＬＳＰＥＲＳＥ　１７０００、ＳＯＬＳＰＥＲＳＥ　１８０００、ＳＯＬＳＰＥＲＳＥ　２００００、ＳＯＬＳＰＥＲＳＥ　２１０００、ＳＯＬＳＰＥＲＳＥ　２４０００ＳＣ、ＳＯＬＳＰＥＲＳＥ　２４０００ＧＲ、ＳＯＬＳＰＥＲＳＥ　２６０００、ＳＯＬＳＰＥＲＳＥ　２７０００、ＳＯＬＳＰＥＲＳＥ　２８０００、ＳＯＬＳＰＥＲＳＥ　３１８４５、ＳＯＬＳＰＥＲＳＥ　３２０００、ＳＯＬＳＰＥＲＳＥ　３２５００、ＳＯＬＳＰＥＲＳＥ　３２５５０、ＳＯＬＳＰＥＲＳＥ　３４７５０、ＳＯＬＳＰＥＲＳＥ　３５１００、ＳＯＬＳＰＥＲＳＥ　３５２００、ＳＯＬＳＰＥＲＳＥ　３６０００、ＳＯＬＳＰＥＲＳＥ　３６６００、ＳＯＬＳＰＥＲＳＥ　３７５００、ＳＯＬＳＰＥＲＳＥ　３８５００、ＳＯＬＳＰＥＲＳＥ　３９０００、ＳＯＬＳＰＥＲＳＥ　４１０００（日本ルーブリゾール株式会社製）；アジスパーＰＢ８２１、アジスパーＰＢ８２２、アジスパーＰＢ８８１、アジスパーＰＮ－４１１、アジスパーＰＡ－１１１、（味の素ファインテクノ株式会社製）；ＤＩＳＰＡＲＬＯＮ　ＫＳ－８６０、ＤＩＳＰＡＲＬＯＮ　ＫＳ－８７３Ｎ、ＤＩＳＰＡＲＬＯＮ　７００４、ＤＩＳＰＡＲＬＯＮ　１８３１、ＤＩＳＰＡＲＬＯＮ　１８５０、ＤＩＳＰＡＲＬＯＮ　１８６０、ＤＩＳＰＡＲＬＯＮ　ＤＡ－７３０１、ＤＩＳＰＡＲＬＯＮ　ＤＡ－３２５、ＤＩＳＰＡＲＬＯＮ　ＤＡ－３７５、ＤＩＳＰＡＲＬＯＮ　ＤＡ－２３４（楠本化成株式会社製）；フローレン　ＤＯＰＡ－１５Ｂ、フローレン　ＤＯＰＡ－１７ＨＦ、フローレン　ＤＯＰＡ－２２、フローレン　ＤＯＰＡ－３３、フローレン　Ｇ－７００、フローレン　Ｇ－８２０、フローレン　Ｇ－９００（共栄社化学株式会社製）等が挙げられる。これらの顔料分散剤は、１種類又は２種類以上を組み合わせて使用してもよい。 As the polymer dispersant, those commercially available as pigment dispersants can be used, and specifically, ANTI-TERRA-U, ANTI-TERRA-205, DISPERBYK-101, DISPERBYK-102. , DISPERBYK-106, DISPERBYK-108, DISPERBYK-109, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-116, DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK-142, DISPERBYK-142, DISPERBYK-142 -162, DISPERBYK-163, DISPERBYK-164, DISPERBYK-166, D SPERBYK-167, DISPERBYK-168, DISPERBYK-170, DISPERBYK-171, DISPERBYK-174, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK-184, DISPERBYK-185, DISPERBYK-185, DISPERBYK-185 2008, DISPERBYK-2009, DISPERBYK-2022, DISPERBYK-2025, DISPERBYK-2050, DISPERBYK-2070, DISPERBYK-2096, DISPERBYK-2150, DISPERBYK-2155, DISPERBYK-2163, DISPER416-2 BYK-P104, BYK-P104S, BYK-P105, BYK-9076, BYK-9077, BYK-220S (manufactured by BYK Japan); EFKA 4008, EFKA 4009, EFKA 4046, EFKA 4047, EFKA 4010, EFKA 4010, EFKA , EFKA 4020, EFKA 4050, EFKA 4055, EFKA 4060, EFKA 4080, EFKA 4300, EFKA 4330, EFKA 4400, EFKA 4401, EFKA 4402, EFKA 4403, EFKA 4406, EFKA 4406, EFKA 4403 5054, EFKA 5055, EFKA 5063, EFKA 5064 , EFKA 5065, EFKA 5066, EFKA 5070 (manufactured by BASF Japan Co., Ltd.); SOLSPERSE 27000, SOLSPERSE 28000, SOLSPERSE 31845, SOLSPERSE 32000, SOLSPERSE 32500, SOLSPERSE 32550, SOLSPERSE 34 50, SOLSPERSE 35100, SOLSPERSE 35200, SOLSPERSE 36000, SOLSPERSE 36600, SOLSPERSE 37500, SOLSPERSE 38500, SOLSPERSE 39000, SOLPERSE 41000 (manufactured by Nippon Lubrizol Co., Ltd.); -111, (Ajinomoto Fine Techno Co., Ltd.); DISPARLON KS-860, DISPARLON KS-873N, DISPARLON 7004, DISPARLON 1831, DISPARLON 1850, DISPARLON 1860, DISPARLON DA-73 1, DISPARLON DA-325, DISPARLON DA-375, DISPARLON DA-234 (manufactured by Enomoto Kasei Co., Ltd.); Floren DOPA-15B, Floren DOPA-17HF, Floren DOPA-22, Floren DOPA-33, Floren G-700, Floren G-820, Floren G-900 (manufactured by Kyoeisha Chemical Co., Ltd.) and the like. These pigment dispersants may be used alone or in combination of two or more.
　次に、本発明に係る銀微粒子の製造方法について述べる。 Next, a method for producing silver fine particles according to the present invention will be described.
　本発明に係る銀微粒子は、銀塩錯体含有水溶液に還元剤含有水溶液を添加して銀微粒子を還元析出させる銀微粒子の製造方法、又は、還元液に硝酸銀水溶液を添加して銀微粒子を還元析出させる銀微粒子の製造方法のいずれによっても得ることができる。また、本発明の第２の態様に係る平均粒子径（ＤＳＥＭ）が１００ｎｍ未満の銀微粒子の製造方法として銀塩錯体のアルコール溶液を還元剤溶液に添加して銀微粒子を還元析出させる溶剤反応系における銀微粒子の製造方法も採用できる。いずれの場合においても、反応から乾燥までの全ての工程を３０℃以下の温度範囲で行なうことが重要である。 The silver fine particles according to the present invention are prepared by adding a reducing agent-containing aqueous solution to a silver salt complex-containing aqueous solution to reduce and precipitate silver fine particles, or by adding a silver nitrate aqueous solution to a reducing solution and reducing and precipitating silver fine particles. It can be obtained by any method for producing silver fine particles. In addition, as a method for producing silver fine particles having an average particle diameter (D SEM ) of less than 100 nm according to the second aspect of the present invention, a solvent reaction in which an alcohol solution of a silver salt complex is added to a reducing agent solution to reduce and precipitate silver fine particles. A method for producing silver fine particles in the system can also be adopted. In any case, it is important to perform all steps from reaction to drying in a temperature range of 30 ° C. or lower.
　銀塩錯体含有水溶液に還元剤含有水溶液を添加して銀微粒子を還元析出させる銀微粒子の製造方法の場合、銀塩錯体含有水溶液と還元剤含有水溶液をそれぞれ予め調液しておく。 In the case of a method for producing silver fine particles in which a reducing agent-containing aqueous solution is added to a silver salt complex-containing aqueous solution to reduce and precipitate silver fine particles, the silver salt complex-containing aqueous solution and the reducing agent-containing aqueous solution are respectively prepared in advance.
　本発明における銀塩錯体は、銀原料として硝酸銀もしくは酢酸銀と、アンモニア水、アンモニウム塩又はキレート化合物等を混合することにより得ることができる。アンモニアの添加量としては、アンミン錯体におけるアンモニアの配位数が２であるため、銀１モルに対してアンモニアを２モル以上添加することが好ましい。生産安定性や得られる銀微粒子の粒度分布の改善を考慮すれば、アンモニアの添加量は銀１モル当たり４モル以上がより好ましく、更により好ましくは１０モル以上である。 The silver salt complex in the present invention can be obtained by mixing silver nitrate or silver acetate as a silver raw material with aqueous ammonia, ammonium salt or chelate compound. As the addition amount of ammonia, since the coordination number of ammonia in the ammine complex is 2, it is preferable to add 2 mol or more of ammonia to 1 mol of silver. In consideration of production stability and improvement in the particle size distribution of the resulting silver fine particles, the amount of ammonia added is more preferably at least 4 mol, and even more preferably at least 10 mol per mol of silver.
　本発明における還元剤としては、エリソルビン酸、アスコルビン酸、アルカノールアミン、ヒドロキノン、グルコース、ピロガロール、ヒドラジン、過酸化水素水及びホルムアルデヒドから選ばれる１種又は２種以上を用いることができる。得られる銀微粒子の導電性ペースト中における分散性向上の観点から、有機系還元剤を用いることが好ましく、より好ましくはエリソルビン酸又はアスコルビン酸である。 As the reducing agent in the present invention, one or more selected from erythorbic acid, ascorbic acid, alkanolamine, hydroquinone, glucose, pyrogallol, hydrazine, hydrogen peroxide and formaldehyde can be used. From the viewpoint of improving dispersibility of the obtained silver fine particles in the conductive paste, an organic reducing agent is preferably used, and more preferably erythorbic acid or ascorbic acid.
　還元剤の添加量は、銀１モルに対して１．０モル以上添加することが好ましく、より好ましくは１．０～２．０モルである。殊に、還元剤としてアスコルビン酸又はエリソルビン酸を用いた場合、銀１モルに対して２．０モルを超える場合には、生成した銀微粒子同士が凝集する傾向があるため好ましくない。 The amount of reducing agent added is preferably 1.0 mol or more, and more preferably 1.0 to 2.0 mol, per 1 mol of silver. In particular, when ascorbic acid or erythorbic acid is used as the reducing agent, the amount exceeding 2.0 moles relative to 1 mole of silver is not preferable because the generated silver fine particles tend to aggregate.
　還元液に硝酸銀水溶液を添加して銀微粒子を還元析出させる銀微粒子の製造方法の場合も、還元液と硝酸銀水溶液をそれぞれ予め調液しておく。 Also in the case of a method for producing silver fine particles in which a silver nitrate aqueous solution is added to a reducing solution to reduce and precipitate silver fine particles, the reducing solution and the silver nitrate aqueous solution are prepared in advance.
　本発明における硝酸銀水溶液は、硝酸銀とイオン交換水もしくは純水とを混合することにより得ることができる。水溶液中における硝酸銀の濃度は、０．０８～２．０ｍｏｌ／ｌの範囲であることが好ましく、より好ましくは０．１～１．８ｍｏｌ／ｌである。 The aqueous silver nitrate solution in the present invention can be obtained by mixing silver nitrate with ion-exchanged water or pure water. The concentration of silver nitrate in the aqueous solution is preferably in the range of 0.08 to 2.0 mol / l, more preferably 0.1 to 1.8 mol / l.
　還元液は、アンモニア水とイオン交換水もしくは純水及び還元剤を混合・攪拌することにより得ることができる。なお、還元液に用いる還元剤としては、前述の還元剤を用いることができる。 The reducing solution can be obtained by mixing and stirring ammonia water and ion exchange water or pure water and a reducing agent. In addition, as a reducing agent used for a reducing liquid, the above-mentioned reducing agent can be used.
　還元剤の添加量は、銀１モルに対して１．０モル以上添加することが好ましく、より好ましくは１．０～２．０モルである。殊に、還元剤としてアスコルビン酸又はエリソルビン酸を用いた場合、銀１モルに対して２．０モルを超える場合には、生成した銀微粒子同士が凝集する傾向があるため好ましくない。 The amount of reducing agent added is preferably 1.0 mol or more, and more preferably 1.0 to 2.0 mol, per 1 mol of silver. In particular, when ascorbic acid or erythorbic acid is used as the reducing agent, the amount exceeding 2.0 moles relative to 1 mole of silver is not preferable because the generated silver fine particles tend to aggregate.
　銀塩錯体含有水溶液、還元剤含有水溶液、還元液及び硝酸銀水溶液は、調液する際に、液温を１８℃以下に保ち、銀塩錯体含有水溶液と還元剤含有水溶液又は還元液と硝酸銀水溶液を混合・攪拌する際にも液温が２０℃を超えないよう調整することが好ましい。反応温度が２０℃を超える場合には、銀微粒子の結晶子径ＤＸ（１１１）が大きくなるとともに、結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）の比が１．４０未満となり、低温焼結性が損なわれるため好ましくない。 When preparing a silver salt complex-containing aqueous solution, a reducing agent-containing aqueous solution, a reducing solution, and a silver nitrate aqueous solution, the liquid temperature is kept at 18 ° C. or lower, and a silver salt complex-containing aqueous solution and a reducing agent-containing aqueous solution or a reducing solution and a silver nitrate aqueous solution are used. It is preferable to adjust so that the liquid temperature does not exceed 20 ° C. when mixing and stirring. When the reaction temperature exceeds 20 ° C., the crystallite diameter D X (111) of the silver fine particles increases, and the ratio of crystallite diameter D X (111) / crystallite diameter D X (200) is 1.40. This is not preferable because the low temperature sinterability is impaired.
　銀塩錯体含有水溶液への還元剤含有水溶液の添加又は還元液への硝酸銀水溶液の添加は、可能な限り短時間で行なうことが好ましく、より好ましくは２０秒以内、更により好ましくは１５秒以内である。銀塩錯体含有水溶液への還元剤含有水溶液の添加時間又は還元液への硝酸銀水溶液の添加時間が長くなると、生成した銀微粒子同士が凝集を起こし、粒子サイズが大きくなると共に、粒度分布が大きくなる傾向にある。 The addition of the reducing agent-containing aqueous solution to the silver salt complex-containing aqueous solution or the addition of the silver nitrate aqueous solution to the reducing solution is preferably performed in as short a time as possible, more preferably within 20 seconds, and even more preferably within 15 seconds. is there. When the addition time of the reducing agent-containing aqueous solution to the silver salt complex-containing aqueous solution or the addition time of the silver nitrate aqueous solution to the reducing solution is prolonged, the generated silver fine particles are aggregated to increase the particle size and the particle size distribution. There is a tendency.
　銀塩錯体含有水溶液へ還元剤含有水溶液の添加後又は還元液への硝酸銀水溶液の添加後、生成した銀微粒子同士が凝集しないようゆるやかに攪拌・混合を行った後、常法により濾過・水洗を行う。このとき、濾液の電導度が６０μＳ／ｃｍ以下になるまで洗浄を行う。 After adding the reducing agent-containing aqueous solution to the silver salt complex-containing aqueous solution or after adding the silver nitrate aqueous solution to the reducing solution, gently stirring and mixing so that the generated silver fine particles do not aggregate together, and then filtering and washing by a conventional method. Do. At this time, washing is performed until the electric conductivity of the filtrate is 60 μS / cm or less.
　得られた銀微粒子のケーキを親水性有機溶媒中に再分散させ、銀微粒子表面の水分を親水性有機溶媒に置換した後、常法により濾過した銀微粒子を、温度３０℃以下で乾燥機もしくは真空乾燥を用いて乾燥を行う。乾燥温度が３０℃を超える場合には、銀微粒子の結晶子径ＤＸ（１１１）が大きくなるとともに、結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）の比が１．４０未満となり、低温焼結性が損なわれるため好ましくない。銀微粒子表面の水分を親水性有機溶媒に置換することにより、乾燥後の銀微粒子同士が強固に凝集した状態になるのを防止することができ、その後の粉砕処理又は表面処理・粉砕処理等が容易になる。 The silver fine particle cake obtained was redispersed in a hydrophilic organic solvent, and the water on the surface of the silver fine particles was replaced with a hydrophilic organic solvent. Dry using vacuum drying. When the drying temperature exceeds 30 ° C., the crystallite diameter D X (111) of the silver fine particles increases, and the ratio of crystallite diameter D X (111) / crystallite diameter D X (200) is 1.40. This is not preferable because the low temperature sinterability is impaired. By replacing the water on the surface of the silver fine particles with a hydrophilic organic solvent, it is possible to prevent the silver fine particles after drying from being firmly agglomerated with each other, and subsequent grinding treatment or surface treatment / grinding treatment, etc. It becomes easy.
　親水性有機溶媒としては、メタノール、エタノール、プロパノール等のアルコール及びアセトン等を用いることができる。乾燥による溶媒の除去を考慮すれば、メタノール及びエタノールが好ましい。 As the hydrophilic organic solvent, alcohols such as methanol, ethanol and propanol, acetone and the like can be used. Considering removal of the solvent by drying, methanol and ethanol are preferred.
　上記の水性反応系における製造方法では、第１及び第２の態様のいずれの平均粒子径の銀微粒子を製造できるが、粒径を制御する方法としては、硝酸銀水溶液中における硝酸銀の濃度の調整や還元液中のアンモニア水の濃度の調整が挙げられる。例えば硝酸銀水溶液中における硝酸銀の濃度を高くし、還元液中のアンモニア水の濃度を低くすることにより、主として第１の態様の平均粒子径の銀微粒子を製造でき、反対に、硝酸銀水溶液中における硝酸銀の濃度を低くし、還元液中のアンモニア水の濃度を高くすることにより、主として第２の態様の平均粒子径の銀微粒子を製造できる。 In the production method in the aqueous reaction system, silver fine particles having any of the average particle diameters of the first and second embodiments can be produced. As a method for controlling the particle diameter, adjustment of the concentration of silver nitrate in the aqueous silver nitrate solution or Adjustment of the ammonia water concentration in the reducing solution can be mentioned. For example, by increasing the concentration of silver nitrate in the aqueous silver nitrate solution and lowering the concentration of aqueous ammonia in the reducing solution, the silver fine particles having the average particle diameter of the first aspect can be produced mainly. Conversely, the silver nitrate in the aqueous silver nitrate solution The silver fine particles having the average particle size of the second aspect can be mainly produced by lowering the concentration of the aqueous solution and increasing the concentration of the ammonia water in the reducing solution.
　銀塩錯体のアルコール溶液を還元剤溶液に添加して銀微粒子を還元析出させる溶剤反応系における銀塩錯体のアルコール溶液は、アルコール溶液中で硝酸銀と水溶性あるいは水可溶性であって炭素数２～４の脂肪族アミンの１種類以上とを混合することにより得ることができる。脂肪族アミンは硝酸銀１モルに対して２．０～２．５モルが好ましく、より好ましくは２．０～２．３モルである。脂肪族アミンの量が硝酸銀１モルに対して２．０モル未満の場合には、大きな粒子が生成しやすい傾向がある。 The alcohol solution of a silver salt complex in a solvent reaction system in which an alcohol solution of a silver salt complex is added to a reducing agent solution to reduce and precipitate silver fine particles is water-soluble or water-soluble with silver nitrate in the alcohol solution and has 2 to 2 carbon atoms. It can be obtained by mixing one or more of the four aliphatic amines. The aliphatic amine is preferably 2.0 to 2.5 moles, more preferably 2.0 to 2.3 moles per mole of silver nitrate. When the amount of the aliphatic amine is less than 2.0 mol with respect to 1 mol of silver nitrate, large grains tend to be generated.
　炭素数２～４の脂肪族アミンとしては、水溶性あるいは水可溶性のものを用いることが肝要であり、具体的には、エチルアミン、ｎ－プロピルアミン、ｉｓｏ－プロピルアミン、ｎ－ブチルアミン、ｉｓｏ－ブチルアミン、等を用いることができるが、銀微粒子の低温焼結性及びハンドリング性を考慮すれば、ｎ－プロピルアミン及びｎ－ブチルアミンが好ましい。 As the aliphatic amine having 2 to 4 carbon atoms, it is important to use a water-soluble or water-soluble aliphatic amine, specifically, ethylamine, n-propylamine, iso-propylamine, n-butylamine, iso- Butylamine and the like can be used, but n-propylamine and n-butylamine are preferable in view of the low-temperature sintering property and handling property of the silver fine particles.
　溶剤反応系におけるアルコールとしては、水と相溶性のあるものを用いることができる。具体的には、メタノール、エタノール、プロパノール及びイソプロパノール等を用いることができ、好ましくはメタノール及びエタノールである。これらアルコールは単独でも混合して用いてもよい。 As the alcohol in the solvent reaction system, those having compatibility with water can be used. Specifically, methanol, ethanol, propanol, isopropanol, and the like can be used, and methanol and ethanol are preferable. These alcohols may be used alone or in combination.
　溶剤反応系における還元剤溶液は、アスコルビン酸又はエリソルビン酸を水中に溶解するか、又はアスコルビン酸又はエリソルビン酸を水中に溶解させた後アルコールを添加し混合することにより得ることができる。アスコルビン酸又はエリソルビン酸は硝酸銀１モルに対して１．０～２．０モルが好ましく、より好ましくは１．０～１．８モルである。アスコルビン酸又はエリソルビン酸が硝酸銀１モルに対して２．０モルを超える場合には、生成した銀微粒子同士が凝集する傾向があるため好ましくない。 The reducing agent solution in the solvent reaction system can be obtained by dissolving ascorbic acid or erythorbic acid in water, or dissolving ascorbic acid or erythorbic acid in water and then adding alcohol and mixing. Ascorbic acid or erythorbic acid is preferably 1.0 to 2.0 moles, more preferably 1.0 to 1.8 moles per mole of silver nitrate. When ascorbic acid or erythorbic acid exceeds 2.0 mol with respect to 1 mol of silver nitrate, the generated silver fine particles tend to aggregate, which is not preferable.
　溶剤反応系における還元剤溶液への銀塩錯体のアルコール溶液の添加は、上記銀塩錯体のアルコール溶液を還元液中に滴下することにより行なう。還元反応における反応温度は１５～３０℃の範囲であり、より好ましくは１８～３０℃である。反応温度が３０℃を超える場合、結晶子径が大きくなるため好ましくない。また、滴下速度は３ｍｌ／分以下とすることが好ましい。滴下時間が短い場合には、粒子サイズ及び結晶子径が大きくなる傾向があり好ましくない。 The addition of the alcohol solution of the silver salt complex to the reducing agent solution in the solvent reaction system is performed by dropping the alcohol solution of the silver salt complex into the reducing solution. The reaction temperature in the reduction reaction is in the range of 15 to 30 ° C., more preferably 18 to 30 ° C. When the reaction temperature exceeds 30 ° C., the crystallite size increases, which is not preferable. The dropping rate is preferably 3 ml / min or less. When the dropping time is short, the particle size and the crystallite size tend to increase, which is not preferable.
　滴下終了後、１時間以上攪拌を続けた後、静置することにより銀微粒子を沈降させ、上澄み液をデカンテーションにより取り除いた後、アルコール及び水を用いて常法により濾過・水洗を行う。この時、濾液の電導度が６０μＳ／ｃｍ以下になるまで洗浄を行う。 After completion of the dropping, stirring is continued for 1 hour or more, and then the mixture is allowed to stand to precipitate silver fine particles. The supernatant is removed by decantation, and then filtered and washed with alcohol and water in a conventional manner. At this time, washing is performed until the electric conductivity of the filtrate is 60 μS / cm or less.
　洗浄した銀微粒子を温度３０℃以下で乾燥、もしくは真空乾燥後、常法により粉砕することによって本発明の銀微粒子を得ることができる。乾燥温度が３０℃を超える場合には、銀微粒子の結晶子径ＤＸ（１１１）が大きくなるとともに、結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）の比が１．４０未満となり、低温焼結性が損なわれるため好ましくない。 The silver fine particles of the present invention can be obtained by drying the washed silver fine particles at a temperature of 30 ° C. or lower or by vacuum drying and then pulverizing them by a conventional method. When the drying temperature exceeds 30 ° C., the crystallite diameter D X (111) of the silver fine particles increases, and the ratio of crystallite diameter D X (111) / crystallite diameter D X (200) is 1.40. This is not preferable because the low temperature sinterability is impaired.
　いずれの製造方法においても、乾燥後の銀微粒子は、常法により粉砕することによって本発明の銀微粒子を得ることができる。 In any of the production methods, the silver fine particles of the present invention can be obtained by pulverizing the silver fine particles after drying by a conventional method.
　本発明に係る銀微粒子は、粉砕処理前に、高分子分散剤による表面処理をしておくことが好ましい。本発明の第１の態様においては、上述のように数平均分子量１，０００以上の高分子系分散剤から選ばれる１種又は２種以上によって表面処理をしておくことが好ましい。分子量１，０００以上の高分子化合物による被覆量は、銀微粒子に対して０．１～３．０重量％であることが好ましく、より好ましくは０．２～２．５重量％である。高分子化合物による処理量が上記範囲にあることにより、粉砕処理による十分な処理効果を得ることができる。また、本発明の第２の態様においては、上述のように分子量１０，０００以上の高分子化合物によって表面処理をしておくことが好ましい。分子量１０，０００以上の高分子化合物による被覆量は、銀微粒子に対して０．２～４重量％であることが好ましく、より好ましくは０．３～３重量％である。高分子化合物による処理量が上記範囲にあることにより、粉砕処理による十分な処理効果を得ることができる。高分子化合物によって表面処理をしておくことにより、その後に行う粉砕処理において高い粉砕処理効果が得られ、より均一な粉砕処理が可能となる。一方、高分子化合物を銀微粒子の還元析出反応中に添加した場合は、処理量及び処理効果の均一性に問題があり、その後に行なう粉砕処理において凝集塊が生じ、得られた銀微粒子は導電ペースト中での分散性が困難になるため好ましくない。 The silver fine particles according to the present invention are preferably subjected to a surface treatment with a polymer dispersant before the pulverization treatment. In the 1st aspect of this invention, it is preferable to surface-treat by 1 type (s) or 2 or more types chosen from the polymeric dispersing agent with a number average molecular weight 1,000 or more as mentioned above. The coating amount with a polymer compound having a molecular weight of 1,000 or more is preferably 0.1 to 3.0% by weight, more preferably 0.2 to 2.5% by weight, based on the silver fine particles. When the treatment amount with the polymer compound is within the above range, a sufficient treatment effect by the pulverization treatment can be obtained. In the second aspect of the present invention, it is preferable to perform surface treatment with a polymer compound having a molecular weight of 10,000 or more as described above. The coating amount with a polymer compound having a molecular weight of 10,000 or more is preferably 0.2 to 4% by weight, more preferably 0.3 to 3% by weight, based on the silver fine particles. When the treatment amount with the polymer compound is within the above range, a sufficient treatment effect by the pulverization treatment can be obtained. By performing the surface treatment with the polymer compound, a high pulverization effect can be obtained in the subsequent pulverization treatment, and a more uniform pulverization treatment is possible. On the other hand, when the polymer compound is added during the reduction precipitation reaction of the silver fine particles, there is a problem in the processing amount and the uniformity of the treatment effect, and agglomerates are formed in the subsequent pulverization treatment, and the obtained silver fine particles are electrically conductive. Since dispersibility in the paste becomes difficult, it is not preferable.
　高分子化合物による銀微粒子の表面処理は、親水性有機溶媒による置換・乾燥後の銀微粒子を、高分子化合物を有機溶媒中に溶解させた高分子化合物溶液中に再分散させ、３０～３００分間ゆるやかに攪拌した後、有機溶媒を除去し、３０℃以下で乾燥機もしくは真空乾燥を用いて乾燥を行う。 The surface treatment of the silver fine particles with the polymer compound is carried out by redispersing the silver fine particles after substitution and drying with a hydrophilic organic solvent in a polymer compound solution obtained by dissolving the polymer compound in the organic solvent, for 30 to 300 minutes. After gently stirring, the organic solvent is removed, and drying is performed at 30 ° C. or lower using a dryer or vacuum drying.
　高分子化合物によって表面処理を行った銀微粒子の粉砕は、ジェット式粉砕機を用いることが好ましい。 It is preferable to use a jet type pulverizer to pulverize the silver fine particles that have been surface-treated with the polymer compound.
　次に、本発明に係る銀微粒子を含む導電性ペーストについて述べる。 Next, the conductive paste containing silver fine particles according to the present invention will be described.
　本発明に係る導電性ペーストは、焼成型ペースト及びポリマー型ペーストのいずれの形態でもよく、焼成型ペーストの場合、本発明に係る銀微粒子及びガラスフリットからなり、必要に応じてバインダー樹脂、溶剤等の他の成分を配合してもよい。また、ポリマー型ペーストの場合、本発明に係る銀微粒子及び溶剤からなり、必要に応じて、バインダー樹脂、硬化剤、分散剤、レオロジー調整剤等の他の成分を配合してもよい。 The conductive paste according to the present invention may be in any form of a fired paste and a polymer paste. In the case of a fired paste, the conductive paste is composed of the silver fine particles and the glass frit according to the present invention. Other components may be blended. Moreover, in the case of a polymer type paste, it consists of silver fine particles and a solvent according to the present invention, and if necessary, other components such as a binder resin, a curing agent, a dispersant, and a rheology modifier may be blended.
　バインダー樹脂としては、当該分野において公知のものを使用することができ、例えば、エチルセルロース、ニトロセルロース等のセルロース系樹脂、ポリエステル樹脂、ウレタン変性ポリエステル樹脂、エポキシ変性ポリエステル樹脂、アクリル変性ポリエステル等の各種変性ポリエステル樹脂、ポリウレタン樹脂、塩化ビニル・酢酸ビニル共重合体、アクリル樹脂、エポキシ樹脂、フェノール樹脂、アルキド樹脂、ブチラール樹脂、ポリビニルアルコール、ポリイミド、ポリアミドイミド等が挙げられる。これらバインダー樹脂は、単独でも、又は２種類以上を併用することもできる。 As the binder resin, those known in the art can be used. For example, cellulose resins such as ethyl cellulose and nitrocellulose, various modified materials such as polyester resins, urethane modified polyester resins, epoxy modified polyester resins, and acrylic modified polyesters. Examples include polyester resin, polyurethane resin, vinyl chloride / vinyl acetate copolymer, acrylic resin, epoxy resin, phenol resin, alkyd resin, butyral resin, polyvinyl alcohol, polyimide, and polyamideimide. These binder resins can be used alone or in combination of two or more.
　溶剤としては、当該分野において公知のものを使用することができ、例えば、テトラデカン、トルエン、キシレン、エチルベンゼン、ジエチルベンゼン、イソプロピルベンゼン、アミルベンゼン、ｐ－シメン、テトラリン及び石油系芳香族炭化水素混合物等の炭化水素系溶剤；エチレングリコールモノエチルエーテル、エチレングリコールモノブチルエーテル、プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、プロピレングリコールモノ－ｎ－ブチルエーテル、プロピレングリコールモノ－ｔ－ブチルエーテル、ジエチレングリコールモノエチルエーテル、ジエチレングリコ－ルモノブチルエーテル、ジプロピレングリコールモノメチルエーテル、ジプロピレングリコールモノブチルエーテル、トリプロピレングリコールモノメチルエーテル等のエーテル又はグリコールエーテル系溶剤；エチレングリコールモノメチルエーテルアセテート、エチレングリコールモノエチルエーテルアセテート、エチレングリコールモノブチルエーテルアセテート、プロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノエチルエーテルアセテート等のグリコールエステル系溶剤；メチルイソブチルケトン、シクロヘキサノン等のケトン系溶剤；テルピネオール、リナロール、ゲラニオール、シトロネロール等のテルペンアルコール；ｎ－ブタノール、ｓ－ブタノール、ｔ－ブタノール等のアルコール系溶剤；エチレングリコール、ジエチレングリコール等のグリコール系溶剤；γ－ブチロラクトン及び水等が挙げられる。溶剤は、単独でも、又は２種類以上を併用することもできる。 As the solvent, those known in the art can be used, and examples thereof include tetradecane, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, amylbenzene, p-cymene, tetralin, and petroleum aromatic hydrocarbon mixtures. Hydrocarbon solvents: ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-butyl ether, propylene glycol mono-t-butyl ether, diethylene glycol monoethyl ether, diethylene glycol Monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tri Ether or glycol ether solvents such as propylene glycol monomethyl ether; glycol ester solvents such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate Ketone solvents such as methyl isobutyl ketone and cyclohexanone; terpene alcohols such as terpineol, linalool, geraniol and citronellol; alcohol solvents such as n-butanol, s-butanol and t-butanol; glycol solvents such as ethylene glycol and diethylene glycol; Γ-butyrolactone and water. Solvents can be used alone or in combination of two or more.
　導電性ペースト中の銀微粒子の含有量は用途に応じて様々であるが、例えば配線形成用途の場合などは可能な限り１００重量％に近いことが好ましい。 The content of silver fine particles in the conductive paste varies depending on the application, but it is preferably as close to 100% by weight as possible, for example, in the case of wiring formation.
　本発明に係る導電性ペーストは、各成分を、ライカイ機、ポットミル、三本ロールミル、回転式混合機、二軸ミキサー等の各種混練機、分散機を用いて、混合・分散させることにより得ることができる。 The conductive paste according to the present invention is obtained by mixing and dispersing each component using various kneaders and dispersers such as a laika machine, a pot mill, a three roll mill, a rotary mixer, a twin screw mixer, and the like. Can do.
　本発明に係る導電性ペーストは、スクリーン印刷、インクジェット法、グラビア印刷、転写印刷、ロールコート、フローコート、スプレー塗装、スピンコート、ディッピング、ブレードコート、めっき等各種塗布方法に適用可能である。 The conductive paste according to the present invention can be applied to various coating methods such as screen printing, ink jet method, gravure printing, transfer printing, roll coating, flow coating, spray coating, spin coating, dipping, blade coating, and plating.
　また、本発明に係る導電性ペーストは、ＦＰＤ（フラットパネルディスプレイ）、太陽電池、有機ＥＬ等の電極形成やＬＳＩ基板の配線形成、更には微細なトレンチ、ビアホール、コンタクトホールの埋め込み等の配線形成材料として用いることができる。また、積層セラミックコンデンサや積層インダクタの内部電極形成用等の高温での焼成用途はもちろん、低温焼成が可能であることからフレキシブル基板やＩＣカード、その他の基板上への配線形成材料及び電極形成材料として好適である。また、導電性被膜として電磁波シールド膜や赤外線反射シールド等にも用いることができる。エレクトロニクス実装においては部品実装用接合材として用いることもできる。 In addition, the conductive paste according to the present invention is used for forming electrodes such as FPD (flat panel display), solar cell, organic EL, wiring for LSI substrates, and wiring for filling fine trenches, via holes, contact holes, etc. It can be used as a material. In addition to firing applications at high temperatures, such as for the formation of internal electrodes for multilayer ceramic capacitors and multilayer inductors, as well as low temperature firing, it is possible to form wiring and materials for wiring on flexible substrates, IC cards, and other substrates. It is suitable as. Moreover, it can also be used for an electromagnetic wave shielding film, an infrared reflection shield, etc. as a conductive film. In electronics mounting, it can also be used as a bonding material for component mounting.
＜作用＞
　本発明において重要な点は、Ｘ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０以上である銀微粒子は、低温焼成が可能であるという事実である。そして、この銀微粒子の平均粒子径が（ＤＳＥＭ）、好ましくは３０ｎｍ以上で１μｍ未満であり、非常に広範囲の平均粒子径を選択することが出来る。 <Action>
The important point in the present invention is that the ratio of the crystallite diameter in the Miller indices (111) and (200) by X-ray diffraction [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40. This is the fact that the silver fine particles described above can be fired at a low temperature. The average particle diameter of the silver fine particles is (D SEM ), preferably 30 nm or more and less than 1 μm, and a very wide range of average particle diameters can be selected.
　本発明に係る銀微粒子が低温焼結性に優れている理由は不明であるが、本発明者らが多数の実験を行なった結果、低温での焼結性に優れる銀微粒子は、いずれも結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０以上の値を有することを見出した。これは、結晶子径ＤＸ（１１１）と結晶子径ＤＸ（２００）の比が大きいほど結晶格子の歪みが大きく不安定であり、銀微粒子が活性であることを示しているものと考えられる。 The reason why the silver fine particles according to the present invention are excellent in low-temperature sinterability is unclear, but as a result of many experiments conducted by the present inventors, the silver fine particles excellent in low-temperature sinterability are all crystalline. It has been found that the ratio of crystal diameters [crystallite diameter D X (111) / crystallite diameter D X (200)] has a value of 1.40 or more. This is considered to indicate that the larger the ratio of the crystallite diameter D X (111) and the crystallite diameter D X (200), the more unstable the crystal lattice is, and the more unstable the silver fine particles are. It is done.
　以下に、本発明における実施例を示し、本発明を具体的に説明するが本発明は以下の実施例に限定されるものではない。なお、以下の諸例において、実施例１－１～１－９、比較例１－１～１－５、実施例２－１～２－９、比較例２－１～２－５、実施例３－１～３－９及び比較例３－１～３－５は、本発明の第１の態様における例であり、実施例４－１～４－１３、比較例４－１～４－７、実施例５－１～５－１３及び比較例５－１～５－７は本発明の第１の態様における例である。 Hereinafter, examples of the present invention will be shown and the present invention will be specifically described. However, the present invention is not limited to the following examples. In the following examples, Examples 1-1 to 1-9, Comparative Examples 1-1 to 1-5, Examples 2-1 to 2-9, Comparative Examples 2-1 to 2-5, and Examples Examples 3-1 to 3-9 and comparative examples 3-1 to 3-5 are examples in the first aspect of the present invention. Examples 4-1 to 4-13 and Comparative examples 4-1 to 4-7 Examples 5-1 to 5-13 and Comparative examples 5-1 to 5-7 are examples in the first aspect of the present invention.
　銀微粒子の平均粒子径は、走査型電子顕微鏡写真「Ｓ－４８００」（ＨＩＴＡＣＨＩ製）を用いて粒子の写真を撮影し、該写真を用いて粒子１００個以上について粒子径を測定し、その平均値を算出し、平均粒子径（ＤＳＥＭ）とした。 The average particle diameter of the silver fine particles was obtained by taking a photograph of the particles using a scanning electron micrograph “S-4800” (manufactured by HITACHI), measuring the particle diameter of 100 or more particles using the photograph, The value was calculated and taken as the average particle size (D SEM ).
　銀微粒子の比表面積は、「モノソーブＭＳ－１１」（カンタクロム株式会社製）を用いて、ＢＥＴ法により測定した値で示した。 The specific surface area of the silver fine particles was represented by a value measured by BET method using “Monosorb MS-11” (manufactured by Kantachrome Co., Ltd.).
　銀微粒子の結晶子径ＤＸ（１１１）及び結晶子径ＤＸ（２００）は、Ｘ線回折装置「ＲＩＮＴ２５００」（株式会社リガク製）を用いて、ＣｕのＫα線を線源とした面指数（１，１，１）面及び（２，０，０）面のピークの半値幅を求め、Ｓｃｈｅｒｒｅｒの式より結晶子径を計算した。 The crystallite diameter D X (111) and the crystallite diameter D X (200) of the silver fine particles are obtained by using an X-ray diffractometer “RINT2500” (manufactured by Rigaku Corporation) and a plane index using Cu Kα rays as a radiation source. The half widths of the peaks on the (1, 1, 1) plane and the (2, 0, 0) plane were obtained, and the crystallite diameter was calculated from the Scherrer equation.
　銀微粒子のＸ線回折によるミラー指数（１１１）と（２００）における結晶子径の比は、上述の結晶子径ＤＸ（１１１）及び結晶子径ＤＸ（２００）を用い、［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］より求めた。 The ratio of the crystallite diameter in the Miller index (111) and (200) by X-ray diffraction of the silver fine particles is the above-mentioned crystallite diameter D X (111) and crystallite diameter D X (200). D X (111) / crystallite diameter D X (200)].
　銀微粒子の加熱による結晶子径の変化率（％）は、銀微粒子を１５０℃で３０分間加熱した後の結晶子径ＤＸ（１１１）と加熱前の銀微粒子の結晶子径ＤＸ（１１１）を用いて、下記数１に従って算出した値である。尚、加熱条件を２１０℃で３０分間と変えた場合も同様にして結晶子径の変化率を求めた。 Rate of change of the crystallite diameter by heating the silver particles (%) is the crystallite size after the fine silver particles were heated at 0.99 ° C. 30 min D X of silver particles before heating (111) crystallite diameter D X (111 ) And calculated according to the following formula 1. Note that the rate of change in crystallite diameter was determined in the same manner when the heating condition was changed to 210 ° C. for 30 minutes.
＜数１＞
　結晶子径の変化率（％）＝加熱後の銀微粒子の結晶子径／加熱前の銀微粒子の結晶子径×１００ <Equation 1>
Change rate of crystallite diameter (%) = crystallite diameter of silver fine particles after heating / crystallite diameter of silver fine particles before heating × 100
　本発明の第１の態様における例においての焼成型ペーストを用いた導電性塗膜の特性は、下記の方法により求めた。即ち、後述する焼成型の導電性ペーストをアルミナ基板上に塗布し、１２０℃で３０分予備乾燥した後、２００℃、３００℃、４００℃、５００℃、６００℃で３０分間加熱することにより得られた導電性膜について、４端子電気抵抗測定装置「ロレスタＧＰ／ＭＣＰ－Ｔ６００」（株式会社三菱化学アナリテック製）を用いて測定し、シート抵抗と膜厚より比抵抗を算出し、グラフの横軸に温度、縦軸にシート比抵抗をプロットし、シート比抵抗が１×１０－５Ω・ｃｍ以下となる温度で示した。また、１２０℃、２００℃及び４００℃でそれぞれ３０分間加熱したときの導電性膜のシート比抵抗を示した。 The characteristics of the conductive coating film using the firing paste in the example of the first aspect of the present invention were determined by the following method. That is, a baking type conductive paste described later is applied on an alumina substrate, pre-dried at 120 ° C. for 30 minutes, and then heated at 200 ° C., 300 ° C., 400 ° C., 500 ° C., and 600 ° C. for 30 minutes. The measured conductive film was measured using a four-terminal electrical resistance measuring device “Loresta GP / MCP-T600” (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), and the specific resistance was calculated from the sheet resistance and film thickness. temperature on the horizontal axis, and plots the sheet resistivity on the vertical axis, the sheet resistivity exhibited at a temperature equal to or less than 1 × 10 -5 Ω · cm. Moreover, the sheet specific resistance of the conductive film when heated at 120 ° C., 200 ° C., and 400 ° C. for 30 minutes, respectively, is shown.
　また、ポリマー型ペーストの場合は、後述する導電性ポリマー型の導電性ペーストを、膜厚５０μｍのポリイミドフィルム上に塗布した導電膜を、１２０℃、２１０℃及び３００℃でそれぞれ３０分間加熱したときの導電性膜のシート比抵抗を示した。 In the case of a polymer type paste, when a conductive film obtained by applying a conductive polymer type conductive paste described later on a polyimide film having a thickness of 50 μm is heated at 120 ° C., 210 ° C., and 300 ° C. for 30 minutes, respectively. The sheet specific resistance of the conductive film was shown.
　本発明の第１の態様における例においての導電性塗膜の比抵抗は、後述する導電性ペーストをポリイミドフィルム上に塗布し、１２０℃で予備乾燥した後、１５０℃、２１０℃及び３００℃の各温度において３０分間加熱硬化さることにより得られた導電性膜それぞれについて、４端子電気抵抗測定装置「ロレスタＧＰ／ＭＣＰ－Ｔ６００」（株式会社三菱化学アナリテック製）を用いて測定し、シート抵抗と膜厚より比抵抗を算出した。 The specific resistance of the conductive coating film in the example of the first aspect of the present invention is such that the conductive paste described later is applied on a polyimide film, preliminarily dried at 120 ° C., and then 150 ° C., 210 ° C. and 300 ° C. Each conductive film obtained by heating and curing at each temperature for 30 minutes was measured using a four-terminal electrical resistance measuring device “Loresta GP / MCP-T600” (manufactured by Mitsubishi Chemical Analytech Co., Ltd.), and sheet resistance The specific resistance was calculated from the film thickness.
＜実施例１－１：銀微粒子の製造＞
　５０Ｌの反応塔に還元剤としてエリソルビン酸７３９ｇ（銀１ｍｏｌに対して１．５ｍｏｌ）、純水３２．３Ｌ及びアンモニア水（２５％）７８０ｇ（銀１ｍｏｌに対して４．１ｍｏｌ）を加えた後、１８℃以下となるよう冷却しながら混合・攪拌を行い、還元液を調整した。別に、２０ｍＬのポリ容器に硝酸銀４７５ｇと純水６，３００ｇを加えた後、１８℃以下となるよう冷却しながら混合・攪拌を行い、硝酸銀水溶液を調整した。 <Example 1-1: Production of silver fine particles>
After adding 739 g of erythorbic acid (1.5 mol with respect to 1 mol of silver), 32.3 L of pure water and 780 g of ammonia water (25%) (4.1 mol with respect to 1 mol of silver) as a reducing agent to a 50 L reaction tower, While reducing to 18 ° C. or lower, mixing and stirring were performed to prepare a reducing solution. Separately, 475 g of silver nitrate and 6,300 g of pure water were added to a 20 mL plastic container, and then mixed and stirred while cooling to 18 ° C. or lower to prepare a silver nitrate aqueous solution.
　次いで、反応系を２０℃以下になるよう冷却しつつ、攪拌しながら硝酸銀水溶液を還元液に添加した（添加時間は１０秒以下）。添加終了後、３０分間攪拌した後、３０分間静置して固形物を沈降させた。上澄み液をデカンテーションにより取り除いた後、ろ紙を用いて吸引ろ過し、続いて、純水を用いてろ液の電導度が７μＳ／ｃｍになるまで洗浄・ろ過を行った。 Next, while cooling the reaction system to 20 ° C. or less, an aqueous silver nitrate solution was added to the reducing solution while stirring (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using a filter paper, and then washed and filtered using pure water until the conductivity of the filtrate reached 7 μS / cm.
　得られた銀微粒子のケーキをメタノール溶液中に再分散させ、銀微粒子表面の水分をメタノールに置換・濾過後、真空乾燥機中２５℃で６時間乾燥した。次いで、純水とメタノールの混合用液（水：メタノール比が１：１０）中に高分子化合物「ＤＩＳＰＥＲＢＹＫ－１０６」（商品名：ビックケミー・ジャパン株式会社製）を２．４ｇ分散させた溶液に、得られた銀微粒子３００ｇを添加（銀微粒子に対して０．８重量％）し、真空乾燥機中２５℃で１２時間乾燥した後、ジェット式粉砕機により粉砕して実施例１－１の銀微粒子を得た。 The obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours. Next, 2.4 g of a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) was dispersed in a liquid for mixing pure water and methanol (water: methanol ratio 1:10). Then, 300 g of the obtained silver fine particles were added (0.8 wt% with respect to the silver fine particles), dried in a vacuum dryer at 25 ° C. for 12 hours, and then pulverized by a jet type pulverizer. Silver fine particles were obtained.
　得られた銀微粒子の粒子形状は粒状、平均粒子径（ＤＳＥＭ）は２６８ｎｍ、結晶子径ＤＸ（１１１）は１４．２ｎｍ、結晶子径ＤＸ（２００）は９．０ｎｍ、ＤＸ（１１１）／ＤＸ（２００）は１．５８、ＢＥＴ比表面積値は１．５ｍ２／ｇであり、結晶子径の変化率（１５０℃×３０分）は１２８％、結晶子径の変化率（２１０℃×３０分）は１７９％であった。 The obtained silver fine particles have a granular shape, an average particle diameter (D SEM ) of 268 nm, a crystallite diameter D X (111) of 14.2 nm, a crystallite diameter D X (200) of 9.0 nm, D X ( 111) / D X (200) is 1.58, BET specific surface area value is 1.5 m 2 / g, change rate of crystallite diameter (150 ° C. × 30 minutes) is 128%, change rate of crystallite diameter (210 ° C. × 30 minutes) was 179%.
＜実施例２－１：導電性ペーストの製造（焼成型ペースト）＞
　実施例１－１の銀微粒子　１００重量部に対してエチルセルロース樹脂　２．５重量部、無鉛ガラスフリット　２．５重量部、フタル酸ジノルマルブチル　３．０重量部及びテキサノール／１－フェノキシ－２－プロパノール（１：１）　１５．４重量部を加え、自転・公転ミキサー「あわとり練太郎　ＡＲＥ－３１０」（株式会社シンキー社製、登録商標）を用いてプレミックスを行った後、３本ロールを用いて均一に混練・分散処理を行い、実施例２－１の導電性ペースト（焼成型ペースト）を得た。 <Example 2-1: Production of conductive paste (fired paste)>
Silver fine particles of Example 1-1 2.5 parts by weight of ethyl cellulose resin, 2.5 parts by weight of lead-free glass frit, 3.0 parts by weight of dinormal butyl phthalate and texanol / 1-phenoxy-2- After adding 15.4 parts by weight of propanol (1: 1) and performing premixing using a rotating / revolving mixer “Awatori Nertaro ARE-310” (registered trademark, manufactured by Sinky Corporation), three rolls The mixture was uniformly kneaded and dispersed to obtain a conductive paste (fired paste) of Example 2-1.
　上記で得られた導電性ペースト（焼成型ペースト）をアルミナ基板上に塗布し、１２０℃で３０分予備乾燥した後、２００℃、３００℃、４００℃、５００℃、６００℃で３０分間加熱することにより導電性塗膜を得た。 The conductive paste (baked paste) obtained above is applied onto an alumina substrate, pre-dried at 120 ° C. for 30 minutes, and then heated at 200 ° C., 300 ° C., 400 ° C., 500 ° C., and 600 ° C. for 30 minutes. As a result, a conductive coating film was obtained.
　得られた導電性塗膜のシート比抵抗が１．０×１０－５Ω・ｃｍ以下になる温度は１９５℃であった。また、１２０℃で３０分間加熱処理した場合の比抵抗は７．７×１０－５Ω・ｃｍであり、２００℃で３０分間加熱処理した場合の比抵抗は９．１×１０－６Ω・ｃｍであり、４００℃で３０分間加熱処理した場合の比抵抗は４．７×１０－６Ω・ｃｍであった。 The temperature at which the sheet specific resistance of the obtained conductive coating film was 1.0 × 10 −5 Ω · cm or less was 195 ° C. The specific resistance when heat-treated at 120 ° C. for 30 minutes is 7.7 × 10 −5 Ω · cm, and the specific resistance when heat-treated at 200 ° C. for 30 minutes is 9.1 × 10 −6 Ω · cm. The specific resistance was 4.7 × 10 −6 Ω · cm when heat-treated at 400 ° C. for 30 minutes.
＜実施例３－１：導電性ペーストの製造（ポリマー型ペースト）＞
　実施例１－１の銀微粒子１００重量部に対してポリエステル樹脂１１．０重量部及び硬化剤１．４重量部と、導電性ペーストにおける銀微粒子の含有量が７０ｗｔ％となるようにジエチレングリコールモノエチルエーテルを加え、プレミックスを行った後、３本ロールを用いて均一に混練・分散処理を行い、実施例３－１の導電性ペーストを得た。 <Example 3-1: Production of conductive paste (polymer type paste)>
11.0 parts by weight of polyester resin and 1.4 parts by weight of curing agent with respect to 100 parts by weight of silver fine particles of Example 1-1, and diethylene glycol monoethyl so that the content of silver fine particles in the conductive paste is 70 wt%. After adding ether and premixing, the mixture was uniformly kneaded and dispersed using three rolls to obtain the conductive paste of Example 3-1.
　上記で得られた導電性ペースト（ポリマー型ペースト）を膜厚５０μｍのポリイミドフィルム上に塗布し、１２０℃、２１０℃及び３００℃でそれぞれ３０分間加熱することにより導電性塗膜を得た。 The conductive paste (polymer type paste) obtained above was applied onto a polyimide film having a thickness of 50 μm and heated at 120 ° C., 210 ° C. and 300 ° C. for 30 minutes, respectively, to obtain a conductive coating film.
　得られた導電性塗膜を１２０℃で３０分間加熱処理した場合の比抵抗は３．７×１０－４Ω・ｃｍであり、２１０℃で３０分間加熱処理した場合の比抵抗は２．８×１０－６Ω・ｃｍであり、３００℃で３０分間加熱処理した場合の比抵抗は９．８×１０－６Ω・ｃｍであった。 The specific resistance when the obtained conductive film is heat-treated at 120 ° C. for 30 minutes is 3.7 × 10 −4 Ω · cm, and the specific resistance when heat-treated at 210 ° C. for 30 minutes is 2.8. × a 10 -6 Ω · cm, the specific resistance in the case of heat treatment at 300 ° C. 30 minutes was 9.8 × 10 -6 Ω · cm.
　前記実施例１－１、実施例２－１及び実施例３－１に従って銀微粒子及び導電性ペーストを作製した。各製造条件及び得られた銀微粒子末及び電性ペーストの諸特性を示す。 Silver fine particles and a conductive paste were prepared according to Example 1-1, Example 2-1, and Example 3-1. Various characteristics of each production condition and the obtained silver fine particle powder and electric paste are shown.
＜実施例１－２～１－４及び比較例１－１～１－２＞
　銀微粒子の生成条件を種々変更することにより、銀微粒子得た。なお、比較例１－５の粒子は市販のミクロンサイズの銀粒子粉末である。 <Examples 1-2 to 1-4 and Comparative Examples 1-1 to 1-2>
Silver fine particles were obtained by variously changing the production conditions of the silver fine particles. The particles of Comparative Example 1-5 are commercially available micron-sized silver particle powders.
　このときの製造条件を表１に、得られた銀微粒子の諸特性を表３に示す。 The production conditions at this time are shown in Table 1, and the characteristics of the obtained silver fine particles are shown in Table 3.
＜実施例１－６：銀微粒子の製造＞
　５０Ｌの反応塔に銀原料として硝酸銀５９５ｇ、純水３８Ｌ及びアンモニア水（２５％）２，３８１ｇ（銀１ｍｏｌに対して１０．０ｍｏｌ）を加えた後、１０℃以下となるよう冷却しながら混合・攪拌を行い、銀塩錯体水溶液を調整した。別に、２０Ｌのポリ容器に還元剤としてエリソルビン酸９２５ｇ（銀１ｍｏｌに対して１．５ｍｏｌ）、と純水８，３３３ｇを加えた後、１０℃以下となるよう冷却しながら混合・攪拌を行い、還元剤含有水溶液を調整した。 <Example 1-6: Production of silver fine particles>
After adding 595 g of silver nitrate, 38 L of pure water and 2,381 g of ammonia water (25%) (10.0 mol to 1 mol of silver) as a silver raw material to a 50 L reaction tower, the mixture was mixed while cooling to 10 ° C. or less. Stirring was performed to prepare a silver salt complex aqueous solution. Separately, after adding 925 g of erythorbic acid (1.5 mol with respect to 1 mol of silver) and 8,333 g of pure water as a reducing agent to a 20 L plastic container, mixing and stirring are performed while cooling to 10 ° C. or less. A reducing agent-containing aqueous solution was prepared.
　次いで、反応系を１０℃以下になるよう冷却しつつ、攪拌しながら還元剤含有水溶液を銀塩錯体水溶液に添加した（添加時間は１０秒以下）。添加終了後、３０分間攪拌した後、３０分間静置して固形物を沈降させた。上澄み液をデカンテーションにより取り除いた後、ろ紙を用いて吸引ろ過し、続いて、純水を用いてろ液の電導度が２０μＳ／ｃｍになるまで洗浄・ろ過を行った。 Next, the reducing agent-containing aqueous solution was added to the silver salt complex aqueous solution with stirring while cooling the reaction system to 10 ° C. or less (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using a filter paper, and then washed and filtered using pure water until the electric conductivity of the filtrate reached 20 μS / cm.
　得られた銀微粒子のケーキをメタノール溶液中に再分散させ、銀微粒子表面の水分をメタノールに置換・濾過後、真空乾燥機中２５℃で６時間乾燥した。次いで、純水とメタノールの混合用液（水：メタノール比が１：１０）中に高分子化合物「ＤＩＳＰＥＲＢＹＫ－１０６」（商品名：ビックケミー・ジャパン株式会社製）を３．６ｇ分散させた溶液に、得られた銀微粒子３００ｇを添加（銀微粒子に対して１．２重量％）し、真空乾燥機中２５℃で１２時間乾燥した後、ジェット式粉砕機により粉砕して実施例１－１の銀微粒子を得た。 The obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours. Next, 3.6 g of a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) was dispersed in a pure water / methanol mixture (water: methanol ratio 1:10). Then, 300 g of the obtained silver fine particles were added (1.2% by weight based on the silver fine particles), dried in a vacuum dryer at 25 ° C. for 12 hours, and then pulverized by a jet type pulverizer. Silver fine particles were obtained.
＜実施例１－７～１－９及び比較例１－３～１－４＞
　銀微粒子の生成条件を種々変更することにより、銀微粒子得た。 <Examples 1-7 to 1-9 and Comparative Examples 1-3 to 1-4>
Silver fine particles were obtained by variously changing the production conditions of the silver fine particles.
　このときの製造条件を表２に、得られた銀微粒子の諸特性を表３に示す。 The production conditions at this time are shown in Table 2, and the characteristics of the obtained silver fine particles are shown in Table 3.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
＜導電性ペースト（焼成型ペースト）の製造＞
＜実施例２－２～２－９及び比較例２－１～２－５＞
　銀微粒子の種類を種々変化させた以外は、前記実施例２－１の導電性ペースト（焼成型ペースト）の作製方法に従って導電性ペースト及び導電性塗膜を製造した。 <Manufacture of conductive paste (fired paste)>
<Examples 2-2 to 2-9 and Comparative Examples 2-1 to 2-5>
A conductive paste and a conductive coating film were produced according to the method for producing a conductive paste (baked paste) of Example 2-1 except that the type of silver fine particles was variously changed.
　このときの製造条件及び得られた導電性塗膜の諸特性を表４に示す。 Table 4 shows the manufacturing conditions and various characteristics of the obtained conductive coating film.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
＜導電性ペースト（ポリマー型ペースト）の製造＞
＜実施例３－２～３－９及び比較例３－１～３－５＞
　銀微粒子の種類を種々変化させた以外は、前記実施例３－１の導電性ペースト（ポリマー型ペースト）の作製方法に従って導電性ペースト及び導電性塗膜を製造した。 <Manufacture of conductive paste (polymer type paste)>
<Examples 3-2 to 3-9 and Comparative Examples 3-1 to 3-5>
A conductive paste and a conductive coating film were manufactured according to the method for preparing a conductive paste (polymer type paste) of Example 3-1 except that the type of silver fine particles was variously changed.
　このときの製造条件及び得られた導電性塗膜の諸特性を表５に示す。 Table 5 shows the manufacturing conditions and various characteristics of the obtained conductive coating film.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
＜実施例４－１：銀微粒子の製造＞
　５０Ｌの反応塔に還元剤としてエリソルビン酸７３９ｇ（銀１ｍｏｌに対して１．５ｍｏｌ）、純水３３．４Ｌ及びアンモニア水（２５％）３，８０８ｇ（銀１ｍｏｌに対して２０ｍｏｌ）を加えた後、１８℃以下となるよう冷却しながら混合・攪拌を行い、還元液を調整した。別に、２０Ｌのポリ容器に硝酸銀４７５ｇと純水１，９００ｇを加えた後、１８℃以下となるよう冷却しながら混合・攪拌を行い、硝酸銀水溶液を調整した。 <Example 4-1: Production of silver fine particles>
After adding 739 g of erythorbic acid (1.5 mol with respect to 1 mol of silver), 33.4 L of pure water and 3,808 g of ammonia water (25%) (20 mol with respect to 1 mol of silver) as a reducing agent to a 50 L reaction tower, While reducing to 18 ° C. or lower, mixing and stirring were performed to prepare a reducing solution. Separately, 475 g of silver nitrate and 1,900 g of pure water were added to a 20 L plastic container, and then mixed and stirred while cooling to 18 ° C. or lower to prepare a silver nitrate aqueous solution.
　次いで、反応系を２０℃以下になるよう冷却しつつ、攪拌しながら硝酸銀水溶液を還元液に添加した（添加時間は１０秒以下）。添加終了後、３０分間攪拌した後、３０分間静置して固形物を沈降させた。上澄み液をデカンテーションにより取り除いた後、ろ紙を用いて吸引ろ過し、続いて、純水を用いてろ液の電導度が３８μＳ／ｃｍになるまで洗浄・ろ過を行った。 Next, while cooling the reaction system to 20 ° C. or less, an aqueous silver nitrate solution was added to the reducing solution while stirring (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using filter paper, and then washed and filtered using pure water until the conductivity of the filtrate reached 38 μS / cm.
　得られた銀微粒子のケーキをメタノール溶液中に再分散させ、銀微粒子表面の水分をメタノールに置換・濾過後、真空乾燥機中２５℃で６時間乾燥した。次いで、得られた銀微粒子３００ｇに対してメタノール溶液中に分散させた高分子化合物「ＤＩＳＰＥＲＢＹＫ－１０６」（商品名：ビックケミー・ジャパン株式会社製）を４．２ｇ添加し（銀微粒子に対して１．４重量％）、９０分攪拌・混合した後、メタノールを蒸留除去した。次いで、真空乾燥機中２５℃で６時間乾燥した後、ジェット式粉砕機により粉砕して実施例４－１の銀微粒子を得た。 The obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours. Next, 4.2 g of a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) dispersed in a methanol solution was added to 300 g of the obtained silver fine particles (1 per silver fine particle). 4% by weight) and after stirring and mixing for 90 minutes, the methanol was distilled off. Next, after drying in a vacuum dryer at 25 ° C. for 6 hours, the fine particles of Example 4-1 were obtained by pulverization with a jet pulverizer.
　得られた銀微粒子の粒子形状は粒状、平均粒子径（ＤＳＥＭ）は８６．０ｎｍ、結晶子径ＤＸ（１１１）は１５．４ｎｍ、結晶子径ＤＸ（２００）は９．５ｎｍ、ＤＸ（１１１）／ＤＸ（２００）は１．６２、ＢＥＴ比表面積値は２．９ｍ２／ｇであり、結晶子径の変化率（１５０℃×３０分）は１１８％、結晶子径の変化率（２１０℃×３０分）は１４５％であった。 The obtained silver fine particles have a granular shape, the average particle diameter (D SEM ) is 86.0 nm, the crystallite diameter D X (111) is 15.4 nm, the crystallite diameter D X (200) is 9.5 nm, D X (111) / D X (200) is 1.62, BET specific surface area value is 2.9 m 2 / g, change rate of crystallite diameter (150 ° C. × 30 minutes) is 118%, The rate of change (210 ° C. × 30 minutes) was 145%.
＜実施例５－１：導電性ペーストの製造＞
　実施例４－１の銀微粒子１００重量部に対してポリエステル樹脂１１．０重量部及び硬化剤１．４重量部と、導電性ペーストにおける銀微粒子の含有量が７０ｗｔ％となるようにジエチレングリコールモノエチルエーテルを加え、自転・公転ミキサー「あわとり練太郎　ＡＲＥ－３１０」（株式会社シンキー社製、登録商標）を用いてプレミックスを行った後、３本ロールを用いて均一に混練・分散処理を行い、導電性ペーストを得た。 <Example 5-1: Production of conductive paste>
Diethylene glycol monoethyl such that 11.0 parts by weight of the polyester resin and 1.4 parts by weight of the curing agent with respect to 100 parts by weight of the silver fine particles of Example 4-1 and the content of the silver fine particles in the conductive paste is 70 wt%. Ether is added and premixed using a rotating / revolving mixer “Awatori Nertaro ARE-310” (registered trademark, manufactured by Sinky Corporation), and then uniformly mixed and dispersed using three rolls. Conductive paste was obtained.
　上記で得られた導電性ペーストを膜厚５０μｍのポリイミドフィルム上に塗布し、１２０℃、２１０℃及び３００℃でそれぞれ３０分間加熱することにより導電性塗膜を得た。 The conductive paste obtained above was applied onto a polyimide film having a thickness of 50 μm and heated at 120 ° C., 210 ° C. and 300 ° C. for 30 minutes, respectively, to obtain a conductive coating film.
　得られた導電性塗膜を１２０℃で３０分間加熱処理した場合の比抵抗は１．５×１０－５Ω・ｃｍであり、２１０℃で３０分間加熱処理した場合の比抵抗は６．８×１０－６Ω・ｃｍであり、３００℃で３０分間加熱処理した場合の比抵抗は３．１×１０－６Ω・ｃｍであった。 The specific resistance when the obtained conductive coating film is heat-treated at 120 ° C. for 30 minutes is 1.5 × 10 −5 Ω · cm, and the specific resistance when heat-treated at 210 ° C. for 30 minutes is 6.8. × a 10 -6 Ω · cm, the specific resistance in the case of heat treatment at 300 ° C. 30 minutes was 3.1 × 10 -6 Ω · cm.
　前記実施例４－１及び実施例５－１に従って銀微粒子及び導電性ペーストを作製した。各製造条件及び得られた銀微粒子末及び電性ペーストの諸特性を示す。 Silver fine particles and a conductive paste were produced according to Example 4-1 and Example 5-1. Various characteristics of each production condition and the obtained silver fine particle powder and electric paste are shown.
＜実施例４－２～４－５及び比較例４－１～４－２＞
　銀微粒子の生成条件を種々変更することにより、銀微粒子得た。 <Examples 4-2 to 4-5 and Comparative Examples 4-1 to 4-2>
Silver fine particles were obtained by variously changing the production conditions of the silver fine particles.
　このときの製造条件を表６に、得られた銀微粒子の諸特性を表９に示す。 The production conditions at this time are shown in Table 6, and the various characteristics of the obtained silver fine particles are shown in Table 9.
＜実施例４－６：銀微粒子の製造＞
　５０Ｌの反応塔に銀原料として硝酸銀４７５ｇ及びアンモニア水（２５％）３，８０８ｇ（銀１ｍｏｌに対して２０ｍｏｌ）を加えた後、８℃以下となるよう冷却しながら混合・攪拌を行い、銀塩錯体水溶液を調整した。別に、２０Ｌのポリ容器に還元剤としてエリソルビン酸７３９ｇ（銀１ｍｏｌに対して１．５ｍｏｌ）、と純水３，５３０ｇを加えた後、９℃以下となるよう冷却しながら混合・攪拌を行い、還元剤含有水溶液を調整した。 <Example 4-6: Production of silver fine particles>
After adding 475 g of silver nitrate and 3,808 g of ammonia water (25%) as a silver raw material to a 50 L reaction tower and mixing and stirring while cooling to 8 ° C. or lower, An aqueous complex solution was prepared. Separately, after adding 739 g of erythorbic acid (1.5 mol with respect to 1 mol of silver) and 3,530 g of pure water as a reducing agent to a 20 L plastic container, mixing and stirring while cooling to 9 ° C. or lower, A reducing agent-containing aqueous solution was prepared.
　次いで、反応系を１０℃以下になるよう冷却しつつ、攪拌しながら還元剤含有水溶液を銀塩錯体水溶液に添加した（添加時間は１０秒以下）。添加終了後、３０分間攪拌した後、３０分間静置して固形物を沈降させた。上澄み液をデカンテーションにより取り除いた後、ろ紙を用いて吸引ろ過し、続いて、純水を用いてろ液の電導度が１５μＳ／ｃｍになるまで洗浄・ろ過を行った。 Next, the reducing agent-containing aqueous solution was added to the silver salt complex aqueous solution with stirring while cooling the reaction system to 10 ° C. or less (addition time was 10 seconds or less). After completion of the addition, the mixture was stirred for 30 minutes and then allowed to stand for 30 minutes to precipitate the solid matter. After removing the supernatant by decantation, the filtrate was suction filtered using a filter paper, and then washed and filtered using pure water until the conductivity of the filtrate reached 15 μS / cm.
　得られた銀微粒子のケーキをメタノール溶液中に再分散させ、銀微粒子表面の水分をメタノールに置換・濾過後、真空乾燥機中２５℃で６時間乾燥した。次いで、得られた銀微粒子３００ｇに対してメタノール溶液中に分散させた高分子化合物「ＤＩＳＰＥＲＢＹＫ－１０６」（商品名：ビックケミー・ジャパン株式会社製）を４．２ｇ添加し（銀微粒子に対して１．４重量％）、９０分攪拌・混合した後、メタノールを蒸留除去した。次いで、真空乾燥機中２５℃で６時間乾燥した後、ジェット式粉砕機により粉砕して実施例４－６の銀微粒子を得た。 The obtained silver fine particle cake was redispersed in a methanol solution, the water on the surface of the silver fine particles was replaced with methanol, filtered, and dried in a vacuum dryer at 25 ° C. for 6 hours. Next, 4.2 g of a polymer compound “DISPERBYK-106” (trade name: manufactured by Big Chemie Japan Co., Ltd.) dispersed in a methanol solution was added to 300 g of the obtained silver fine particles (1 per silver fine particle). 4% by weight) and after stirring and mixing for 90 minutes, the methanol was distilled off. Next, after drying at 25 ° C. for 6 hours in a vacuum dryer, the fine particles of Example 4-6 were obtained by pulverization with a jet pulverizer.
＜実施例４－７～４－９及び比較例４－３～４－４＞
　銀微粒子の生成条件を種々変更することにより、銀微粒子得た。 <Examples 4-7 to 4-9 and Comparative Examples 4-3 to 4-4>
Silver fine particles were obtained by variously changing the production conditions of the silver fine particles.
　このときの製造条件を表７に、得られた銀微粒子の諸特性を表９に示す。 The production conditions at this time are shown in Table 7, and the various characteristics of the obtained silver fine particles are shown in Table 9.
＜実施例４－１０：銀微粒子の製造＞
　２Ｌのビーカーに硝酸銀１６０ｇとメタノール８００ｍＬを加えた後、水浴にて冷却しながらｎ－ブチルアミン１５１．６ｇを添加した後、１８℃以下となるよう冷却しながら混合・攪拌してＡ液を調製した。別に、５Ｌのビーカーにエリソルビン酸２４８．８ｇを量り取り、水１６００ｍＬを加え攪拌して溶解した後、メタノール８００ｍＬを加えて１８℃以下となるよう冷却しながら混合・攪拌を行いＢ液を調製した。 <Example 4-10: Production of silver fine particles>
After adding 160 g of silver nitrate and 800 mL of methanol to a 2 L beaker, 151.6 g of n-butylamine was added while cooling in a water bath, and then mixed and stirred while cooling to 18 ° C. or lower to prepare solution A. . Separately, 248.8 g of erythorbic acid was weighed into a 5 L beaker, dissolved by adding 1600 mL of water and stirred, and then mixed and stirred while cooling to 18 ° C. or lower by adding 800 mL of methanol to prepare solution B. .
　次いで、Ｂ液を攪拌し、反応系を２０℃以下になるよう冷却しつつ、Ａ液をＢ液に１時間２０分かけて滴下した。滴下終了後、１４時間攪拌した後、３０分間静置して固形物を沈降させた。上澄み液をデカンテーションにより取り除いた後、ろ紙を用いて吸引ろ過し、続いて、メタノールと純水を用いて洗浄・ろ過した。 Next, the liquid B was stirred and the reaction system was cooled to 20 ° C. or lower, and the liquid A was added dropwise to the liquid B over 1 hour and 20 minutes. After the completion of dropping, the mixture was stirred for 14 hours and then allowed to stand for 30 minutes to precipitate a solid. After removing the supernatant liquid by decantation, suction filtration was performed using a filter paper, followed by washing and filtration using methanol and pure water.
　得られた銀微粒子の固形物を真空乾燥機中３０分で６時間乾燥した後、得られた銀微粒子２４ｇに対してメタノール溶液中に分散させた高分子化合物「ＤＩＳＰＥＲＢＹＫ－１０６」（商品名：ビックケミー・ジャパン株式会社製）を０．４８ｇ添加し（銀微粒子に対して２．０重量％）、９０分攪拌・混合した後、メタノールを蒸留除去した。次いで、真空乾燥機中２５℃で６時間乾燥した後、ジェット式粉砕機により粉砕して実施例４－１０の銀微粒子を得た。 The obtained silver fine particles were dried in a vacuum dryer for 30 minutes for 6 hours, and then the polymer compound “DISPERBYK-106” (trade name: dispersed in a methanol solution with respect to 24 g of the obtained silver fine particles). 0.48 g (manufactured by Big Chemie Japan Co., Ltd.) was added (2.0% by weight based on silver fine particles), and after stirring and mixing for 90 minutes, methanol was distilled off. Next, after drying at 25 ° C. for 6 hours in a vacuum dryer, the fine particles of Example 4-10 were obtained by pulverization with a jet pulverizer.
　このときの製造条件を表８に、得られた銀微粒子の諸特性を表９に示す。 The production conditions at this time are shown in Table 8, and the characteristics of the obtained silver fine particles are shown in Table 9.
＜実施例４－１１～４－１３及び比較例４－５～４－６＞
　銀微粒子の生成条件を種々変更することにより、銀微粒子得た。 <Examples 4-11 to 4-13 and Comparative Examples 4-5 to 4-6>
Silver fine particles were obtained by variously changing the production conditions of the silver fine particles.
　このときの製造条件を表７に、得られた銀微粒子の諸特性を表９に示す。 Table 7 shows the production conditions at this time, and Table 9 shows the characteristics of the obtained silver fine particles.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
＜導電性塗料の製造＞
＜実施例５－２～５－１３及び比較例５－１～５－７＞
　銀微粒子の種類を種々変化させた以外は、前記実施例５－１の導電性塗料の作製方法に従って導電性塗料及び導電性膜を製造した。 <Manufacture of conductive paint>
<Examples 5-2 to 5-13 and Comparative Examples 5-1 to 5-7>
A conductive paint and a conductive film were produced according to the method for producing a conductive paint of Example 5-1 except that the type of silver fine particles was variously changed.
　このときの製造条件及び得られた導電性塗膜の諸特性を表１０に示す。 Table 10 shows the production conditions and various characteristics of the obtained conductive coating film.
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
　本発明に係る銀微粒子は、Ｘ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０以上であることから、低温焼成が可能な導電性ペースト等の原料として好適である。 The silver fine particles according to the present invention have a crystallite diameter ratio [crystallite diameter D X (111) / crystallite diameter D X (200)] of 1.40 and Miller index (111) by X-ray diffraction of 1.40. Because of the above, it is suitable as a raw material for conductive paste and the like that can be fired at a low temperature.

Claims (12)

  1. 　　Ｘ線回折によるミラー指数（１１１）と（２００）における結晶子径の比［結晶子径ＤＸ（１１１）／結晶子径ＤＸ（２００）］が１．４０以上であることを特徴とする銀微粒子。 The ratio of the crystallite diameter in the Miller index (111) and (200) by X-ray diffraction [crystallite diameter D X (111) / crystallite diameter D X (200)] is 1.40 or more. Silver fine particles.
  2. 　平均粒子径（ＤＳＥＭ）が１００ｎｍ以上１μｍ未満である請求項１記載の銀微粒子。 Silver fine particles according to claim 1, wherein the average particle size (D SEM ) is 100 nm or more and less than 1 µm.
  3. 　ミラー指数（１１１）における結晶子径ＤＸ（１１１）が２０ｎｍ以下である請求項１又は２記載の銀微粒子。 Silver fine particles according to claim 1 or 2, wherein the crystallite diameter D X (111) in the Miller index (111) is 20 nm or less.
  4. 　ミラー指数（２００）における結晶子径ＤＸ（２００）が１４ｎｍ以下である請求項１～３の何れかに記載の銀微粒子。 The silver fine particles according to any one of claims 1 to 3, wherein the crystallite diameter D X (200) at the Miller index (200) is 14 nm or less.
  5. 　銀微粒子の粒子表面が数平均分子量１，０００以上の高分子系分散剤から選ばれる１種又は２種以上で被覆されている請求項１～４の何れかに記載の銀微粒子。 The silver fine particles according to any one of claims 1 to 4, wherein the surface of the silver fine particles is coated with one or more kinds selected from polymer dispersants having a number average molecular weight of 1,000 or more.
  6. 　平均粒子径（ＤＳＥＭ）が３０ｎｍ以上１００ｎｍ未満である請求項１記載の銀微粒子。 The silver fine particles according to claim 1, having an average particle size (D SEM ) of 30 nm or more and less than 100 nm.
  7. 　ミラー指数（１１１）における結晶子径ＤＸ（１１１）が２５ｎｍ以下である請求項１又は６記載の銀微粒子。 Silver fine particles according to claim 1 or 6, wherein the crystallite diameter D X (111) in the Miller index (111) is 25 nm or less.
  8. 　ミラー指数（２００）における結晶子径ＤＸ（２００）が１５ｎｍ以下である請求項１、６、７の何れかに記載の銀微粒子。 Silver fine particles according to any one of claims 1, 6, and 7, wherein the crystallite diameter D X (200) in the Miller index (200) is 15 nm or less.
  9. 　銀微粒子の粒子表面が分子量１０，０００以上の高分子化合物で被覆されている請求項１、６～８の何れかに記載の銀微粒子。 9. The silver fine particles according to claim 1, wherein the surface of the silver fine particles is coated with a polymer compound having a molecular weight of 10,000 or more.
  10. 　請求項１～９の何れかに記載の銀微粒子を含む導電性ペースト。 A conductive paste containing the silver fine particles according to any one of claims 1 to 9.
  11. 　請求項１０記載の導電性ペーストを用いて形成された導電性膜。 A conductive film formed using the conductive paste according to claim 10.
  12. 　請求項１１記載の導電性膜を有する電子デバイス。 An electronic device having the conductive film according to claim 11.
PCT/JP2012/068939 2011-07-29 2012-07-26 Fine silver particles, conductive paste containing fine silver particles, conductive film and electronic device WO2013018645A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201280036601.7A CN103702786B (en) 2011-07-29 2012-07-26 Silver microparticle and the conductive paste containing this silver-colored microparticle, conductive film and electronic device
KR1020147001483A KR20140047663A (en) 2011-07-29 2012-07-26 Fine silver particles, conductive paste containing fine silver particles, conductive film and electronic device

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2011-167364 2011-07-29
JP2011167368A JP5773148B2 (en) 2011-07-29 2011-07-29 Silver fine particles, and conductive paste, conductive film and electronic device containing the silver fine particles
JP2011-167368 2011-07-29
JP2011167364A JP5773147B2 (en) 2011-07-29 2011-07-29 Silver fine particles, and conductive paste, conductive film and electronic device containing the silver fine particles

Publications (1)

Publication Number Publication Date
WO2013018645A1 true WO2013018645A1 (en) 2013-02-07

Family

ID=47629170

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/068939 WO2013018645A1 (en) 2011-07-29 2012-07-26 Fine silver particles, conductive paste containing fine silver particles, conductive film and electronic device

Country Status (4)

Country Link
KR (1) KR20140047663A (en)
CN (1) CN103702786B (en)
TW (1) TW201315685A (en)
WO (1) WO2013018645A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018181083A1 (en) * 2017-03-28 2018-10-04 Ｄｏｗａエレクトロニクス株式会社 Bonding material and bonded body using same
US10639713B2 (en) 2014-03-05 2020-05-05 Sekisui Chemical Co., Ltd. Conductive filler, method for manufacturing conductive filler, and conductive paste

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6948764B2 (en) * 2015-06-05 2021-10-13 Ｄｏｗａエレクトロニクス株式会社 Silver fine particle dispersion
CN108650873B (en) * 2018-05-15 2021-03-02 河南科技大学第一附属医院 Environment-friendly device for eliminating radiation hazard of nuclear magnetic resonance to human body

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008190025A (en) * 2007-01-09 2008-08-21 Dowa Electronics Materials Co Ltd Silver fine powder and method for producing the same, and ink
JP2011021252A (en) * 2009-07-16 2011-02-03 Noritake Co Ltd Silver fine particle and method for producing the same
JP2012036481A (en) * 2010-08-11 2012-02-23 Mitsui Mining & Smelting Co Ltd Flat silver particle, and method for producing the same

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4489388B2 (en) * 2003-07-29 2010-06-23 三井金属鉱業株式会社 Method for producing fine silver powder
JP4606012B2 (en) * 2003-11-14 2011-01-05 三井金属鉱業株式会社 Silver paste
JP2005330529A (en) * 2004-05-19 2005-12-02 Dowa Mining Co Ltd Spherical silver powder and its production method
JP2006040650A (en) * 2004-07-26 2006-02-09 Mitsui Mining & Smelting Co Ltd Silver paste and its manufacturing method
JP4756163B2 (en) * 2005-09-16 2011-08-24 Ｄｏｗａエレクトロニクス株式会社 Dispersion and paste of composite particle powder and method for producing silver particle powder used therefor
JP2011080094A (en) * 2009-10-02 2011-04-21 Toda Kogyo Corp Fine silver particle, method for producing same, conductive paste containing the fine silver particles, conductive film, and electronic device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008190025A (en) * 2007-01-09 2008-08-21 Dowa Electronics Materials Co Ltd Silver fine powder and method for producing the same, and ink
JP2011021252A (en) * 2009-07-16 2011-02-03 Noritake Co Ltd Silver fine particle and method for producing the same
JP2012036481A (en) * 2010-08-11 2012-02-23 Mitsui Mining & Smelting Co Ltd Flat silver particle, and method for producing the same

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10639713B2 (en) 2014-03-05 2020-05-05 Sekisui Chemical Co., Ltd. Conductive filler, method for manufacturing conductive filler, and conductive paste
WO2018181083A1 (en) * 2017-03-28 2018-10-04 Ｄｏｗａエレクトロニクス株式会社 Bonding material and bonded body using same
JP2018165387A (en) * 2017-03-28 2018-10-25 Ｄｏｗａエレクトロニクス株式会社 Bonding material and bonding body comprising the same

Also Published As

Publication number Publication date
TW201315685A (en) 2013-04-16
CN103702786B (en) 2015-07-29
CN103702786A (en) 2014-04-02
KR20140047663A (en) 2014-04-22

Similar Documents

Publication Publication Date Title
TWI490063B (en) Silver fine particles and a method for producing the same, and an electric paste containing the silver fine particles, a conductive film, and an electronic device
WO2013099818A1 (en) Silver fine particles, production process therefor, and conductive paste, conductive membrane and electronic device, containing said silver fine particles
Lee et al. A low-cure-temperature copper nano ink for highly conductive printed electrodes
JP5761483B2 (en) Silver fine particles and production method thereof, and conductive paste, conductive film and electronic device containing the silver fine particles
Deng et al. Antioxidative effect of lactic acid-stabilized copper nanoparticles prepared in aqueous solution
JP6274444B2 (en) Method for producing copper powder
JP5773148B2 (en) Silver fine particles, and conductive paste, conductive film and electronic device containing the silver fine particles
KR101533860B1 (en) Copper fine particle, method for producing the same, and copper fine particle dispersion
JP5826435B1 (en) Copper powder
KR101004553B1 (en) Micro Silver Particle-Containing Composition, Method for Producing It, Method for Producing Micro Silver Particle
WO2012133627A1 (en) Silver-coated copper powder and method for producing same, silver-coated copper powder-containing conductive paste, conductive adhesive agent, conductive film, and electric circuit
KR101777342B1 (en) A method to prepare a metallic nanoparticle dispersion
WO2013115339A1 (en) Silver microparticles, method for producing same, and electronic device, conductive film, and conductive paste containing said silver microparticles
JP5924481B2 (en) Method for producing silver fine particles, silver fine particles obtained by the method for producing silver fine particles, and conductive paste containing the silver fine particles
WO2013018645A1 (en) Fine silver particles, conductive paste containing fine silver particles, conductive film and electronic device
JP4879762B2 (en) Silver powder manufacturing method and silver powder
JP5773147B2 (en) Silver fine particles, and conductive paste, conductive film and electronic device containing the silver fine particles
JP2012031478A (en) Silver fine particle and method of manufacturing the same, conductive paste containing the silver fine particle, conductive film, and electronic device
JP7048193B2 (en) Method for manufacturing cuprous oxide particles
KR100819904B1 (en) Metallic ink, and method for forming of electrode using the same and substrate
JP5991459B2 (en) Silver fine particles, production method thereof, and conductive paste, conductive film and electronic device containing the silver fine particles
KR100850874B1 (en) Manufacturing method of ni nano-particles, ni nano-particles and ink composition comprising the same
JP2021501267A (en) Method of manufacturing silver powder and conductive paste containing silver powder
KR20090043262A (en) Surface treated nano-particles, manufacturing method thereof and ink composition comprising the same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12820704

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20147001483

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12820704

Country of ref document: EP

Kind code of ref document: A1