WO2016052275A1 - 被覆銅粒子及びその製造方法 - Google Patents

被覆銅粒子及びその製造方法 Download PDF

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WO2016052275A1
WO2016052275A1 PCT/JP2015/076764 JP2015076764W WO2016052275A1 WO 2016052275 A1 WO2016052275 A1 WO 2016052275A1 JP 2015076764 W JP2015076764 W JP 2015076764W WO 2016052275 A1 WO2016052275 A1 WO 2016052275A1
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copper
copper particles
carboxylic acid
coated copper
aliphatic carboxylic
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PCT/JP2015/076764
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English (en)
French (fr)
Japanese (ja)
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邦宏 福本
優 小山
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協立化学産業株式会社
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Priority to CN201580053024.6A priority Critical patent/CN107073578B/zh
Priority to KR1020177010816A priority patent/KR102200822B1/ko
Publication of WO2016052275A1 publication Critical patent/WO2016052275A1/ja

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/102—Metallic powder coated with organic material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/16—Making metallic powder or suspensions thereof using chemical processes
    • B22F9/30—Making metallic powder or suspensions thereof using chemical processes with decomposition of metal compounds, e.g. by pyrolysis
    • 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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2301/00—Metallic composition of the powder or its coating
    • B22F2301/10—Copper

Definitions

  • the present invention relates to coated copper particles and a method for producing the same.
  • Gold and silver which are noble metals, have characteristics that are relatively difficult to be oxidized. Therefore, when a fine particle dispersion is prepared, it is possible to maintain the contained metal fine particles without forming an oxide film on the surface. Easy. Copper, on the other hand, has a characteristic that it is relatively easily oxidized. When copper particles having a particle diameter of 5 ⁇ m or less, particularly fine copper particles having a particle diameter of 200 nm or less, are related to the size effect and specific surface area, The trend is even more pronounced. For example, when a fine particle dispersion is prepared, the contained fine particles are covered with an oxide film in a short time, and the thickness of the oxide film increases with time. Often converted to a surface oxide layer of copper oxide.
  • the activity of the particle surface is very high. For this reason, even in a method of heating and baking under an inert atmosphere such as nitrogen gas or under vacuum conditions, oxidation may proceed due to a small amount of oxygen present in the atmosphere, and sintering of fine particles may be inhibited. Further, the increase in the surface oxide layer during firing may cause volume shrinkage during reduction and decrease in firing density when reduction firing is performed using hydrogen gas or the like at the final stage of firing.
  • the melting point drop due to the size effect is 1,064 ° C. when gold is taken as an example.
  • the particle diameter is 2 nm
  • the melting point is about 300 ° C.
  • the melting point decreases to a temperature that can be used for electronic materials.
  • it has been reported that almost no drop in melting point is observed when the particle diameter exceeds 20 nm. Therefore, if the particle size is a single nano size of about 2 nm, a melting point drop can be sufficiently expected.
  • a copper fine particle dispersion whose surface is coated with an aliphatic monocarboxylic acid obtained by reducing copper oxide particles in the presence of an aliphatic monocarboxylic acid is known and sintered at a low temperature.
  • the surface treatment copper powder which provided the surface treatment layer formed with the metal salt of the fatty acid on the surface of the copper powder is known, and it is said that the paste viscosity can be reduced when processed into a copper paste ( For example, see JP-A-2002-332502.
  • a method for producing a copper powder for copper paste in which the copper powder is surface-treated with a carboxylic acid-containing organic solvent, is known, and it is said that the viscosity of the copper paste can be reduced (for example, JP-A-2004-2004) (Ref. No. 225122)
  • the manufacturing method of the copper powder which makes a fatty acid containing solution contact the metal copper produced
  • the copper fine particle dispersion described in Japanese Patent Application Laid-Open No. 2013-047365 and the surface-treated copper powder described in Japanese Patent Application Laid-Open No. 2002-332502 tend to fail to obtain sufficient oxidation resistance of the copper particles.
  • the copper powders described in JP-A-2002-332502, JP-A-2004-225122, and JP-A-2003-342621 it is difficult to sufficiently reduce the particle diameter of the copper powder, and sufficient sintering is required. There was a tendency not to be able to obtain cohesion.
  • the present invention provides a coated copper particle having excellent oxidation resistance and sinterability, which has been difficult to achieve with the prior art, and a method for producing the same, which have solved the problems of the prior art. For the purpose.
  • the present inventors have arranged an aliphatic carboxylic acid at a specific density on the surface of copper particles, thereby providing a coated copper having excellent oxidation resistance and sinterability. It was found that particles were obtained.
  • the present invention includes the following aspects.
  • a coated copper particle comprising copper particles and a coating layer containing an aliphatic carboxylic acid arranged at a density of 2.5 to 5.2 molecules per 1 nm 2 on the surface of the copper particles.
  • the coating layer is a thermal decomposition product of the aliphatic carboxylic acid copper complex. It is a covering copper particle given in any 1 paragraph of (1) to (3).
  • the coated copper particles according to any one of (1) to (4) wherein the total content of copper oxide and copper hydroxide is 5% by mass or less.
  • a conductive composition comprising the coated copper particles according to any one of (1) to (6) and a medium.
  • a circuit formed article comprising a substrate and a wiring pattern or a bonding layer, which is disposed on the substrate and is a heat-treated product of the conductive composition according to (8).
  • FIG. 3 is a result of Tof-SIMS measurement of coated copper particles produced in Example 1. It is a result of IR spectrum measurement of the coated copper particles produced in Example 1. 3 is a result of TG-DTA measurement of coated copper particles produced in Example 1.
  • FIG. 3 is an SEM observation image of coated copper particles produced in Example 2. It is a result of IR spectrum measurement of the coated copper particles produced in Example 2. It is the result of the XRD measurement which measured the coated copper particle produced in Example 1 after 2 months storage in air
  • atmosphere. 4 is an SEM observation image of coated copper particles created in Comparative Example 2.
  • the term “process” is not limited to an independent process, and is included in the term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes.
  • the content of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition.
  • the coated copper particles of the present embodiment include copper particles and a coating layer containing an aliphatic carboxylic acid arranged at a density of 2.5 to 5.2 molecules per 1 nm 2 on the surface of the copper particles.
  • the surfaces of the copper particles are coated with a coating layer containing an aliphatic carboxylic acid.
  • the aliphatic carboxylic acid that coats the copper particles is a coating material that localizes on the surface of the copper particles and suppresses oxidation and aggregation, is removed from the particle surface during sintering, and further decomposes or volatilizes below the sintering temperature. Therefore, it is considered that the remaining in the copper film formed by sintering is suppressed.
  • the aliphatic carboxylic acid is adsorbed at a high density on the surface of the copper particles, a strong van der Waals force acts between the aliphatic carboxylic acid molecules, and the aggregates are formed on the surface of the copper particles. It is thought that it has formed.
  • the van der Waals force between the aliphatic carboxylic acids that are coated decreases, so that the coating density decreases.
  • the aliphatic carboxylic acid molecules, which are the coating material that has not been adsorbed are appropriately removed, and better sinterability is exhibited in the portion where the coating density is reduced.
  • the coated copper particles obtained by the production method described later have a uniform particle diameter, they are excellent in dispersibility. Furthermore, since the difference between the crystallite diameter of the copper particles constituting the coated copper particles and the SEM observation diameter is small, the coated copper particles are not constituted by aggregation of a plurality of copper particles, and the coating material and impurities at the aggregated particle boundary portion, It is considered that the presence of an oxide layer or the like inhibits sintering.
  • the particle diameter of the copper particles constituting the coated copper particles is not particularly limited, and can be appropriately selected according to the purpose.
  • the average primary particle diameter of the copper particles is 0.02 ⁇ m or more and 5.0 ⁇ m or less, 0.02 ⁇ m or more and 1.0 ⁇ m or less, 0.02 ⁇ m or more and 0.5 ⁇ m or less, and 0 It can be set to 0.02 ⁇ m or more and 0.2 ⁇ m or less.
  • the average primary particle diameter of the copper particles is calculated as an arithmetic average value of the primary particle diameters of any 20 copper particles by SEM observation.
  • the average primary particle diameter of the copper particles can be regarded as substantially the same as the average primary particle diameter of the coated copper particles.
  • the purity of the copper constituting the copper particles is not particularly limited, and can be appropriately selected depending on the purpose.
  • the purity of the copper particles is, for example, 95% by mass or more, and preferably 97% by mass or more.
  • the total content rate of the copper oxide and copper hydroxide contained in a copper particle is 5 mass% or less, for example, it is preferable that it is 3 mass% or less, and it is especially preferable that it is 1 mass% or less.
  • the copper oxide includes copper (II) oxide and cuprous oxide.
  • the shape of the copper particles is not particularly limited and can be appropriately selected according to the purpose.
  • Examples of the shape of the copper particles include a substantially spherical shape, a plate shape, and a rod shape, and a substantially spherical shape is preferable.
  • the type of the aliphatic carboxylic acid arranged on the surface of the copper particles is not particularly limited, and can be appropriately selected according to the purpose.
  • the number of carboxy groups possessed by the aliphatic carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose and the like.
  • the number of carboxy groups is, for example, 1 to 2, and preferably 1. That is, an aliphatic monocarboxylic acid is preferably used.
  • the aliphatic carboxylic acid may be a saturated aliphatic carboxylic acid or an unsaturated aliphatic carboxylic acid.
  • the aliphatic carboxylic acid is an unsaturated aliphatic carboxylic acid, the number of unsaturated bonds contained in the unsaturated aliphatic group is, for example, 1 to 3, and preferably 1 to 2.
  • the aliphatic group contained in the aliphatic carboxylic acid may be linear or branched, and is preferably linear.
  • the number of carbon atoms of the aliphatic group is, for example, 5 or more, preferably 5 to 21, more preferably 5 to 17, more preferably 7 to 17, and particularly preferably 9 to 17.
  • the boiling point of the aliphatic carboxylic acid is preferably higher than the temperature of the thermal decomposition treatment in the production method described later.
  • the boiling point of the aliphatic carboxylic acid is preferably 120 ° C. or higher, and more preferably 130 ° C. or higher.
  • the upper limit of the boiling point is not particularly limited, and is, for example, 400 ° C. or lower. There exists a tendency for the sinterability of a covering copper particle to improve more that a boiling point is 400 degrees C or less.
  • aliphatic carboxylic acid examples include unsaturated aliphatic carboxylic acids such as oleic acid and linoleic acid; and saturated aliphatic carboxylic acids such as stearic acid, heptadecanoic acid, lauric acid, and octanoic acid. It is preferable that it is at least 1 type selected from.
  • the aliphatic carboxylic acid may be used alone or in combination of two or more.
  • Aliphatic carboxylic acid is disposed on the surface of the copper particles at a density of 2.5 to 5.2 molecules per nm 2 . That is, the surface of the copper particles is coated with a coating layer containing an aliphatic carboxylic acid, and the coating density of the aliphatic carboxylic acid on the surface of the copper particles is 2.5 to 5.2 molecules / nm 2 .
  • Coating density of aliphatic carboxylic acids is preferably 3.0 to 5.2 molecules / nm 2, and more preferably from 3.5 5.2 molecules / nm 2 .
  • the coating density of the aliphatic carboxylic on the surface of the copper particles can be calculated as follows.
  • an organic component adhering to the surface is extracted using LC according to the method described in JP 2012-88242 A and component analysis is performed.
  • TG-DTA measurement thermogravimetry / differential thermal analysis
  • the amount of aliphatic carboxylic acid contained in the coated copper particles is calculated together with the LC analysis result.
  • the average primary particle diameter of a copper particle is measured by SEM image observation. From the above analysis results, the number of molecules of the aliphatic carboxylic acid contained in 1 g of the coated copper particles is represented by the following formula (a).
  • [Number of molecules of aliphatic carboxylic acid] M acid / (M w / N A ) (a)
  • M acid is an aliphatic carboxylic acid content in the coated copper particles 1g (g)
  • M w is the molecular weight of the aliphatic carboxylic acid (g / mol)
  • N A is the Avogadro constant.
  • the number of copper particles in 1 g of the coated copper particles is expressed by the following formula (b) from the copper particle amount M Cu (g) by subtracting the organic component amount from the mass of the coated copper particles by approximating the shape of the copper particles to a sphere. Is done.
  • Number copper particles] M Cu / [(4 ⁇ r 3/3) ⁇ d ⁇ 10 -21] ⁇ (b)
  • M Cu is the amount (g) of copper particles contained in 1 g of the coated copper particles
  • r is the radius (nm) of the primary particle diameter calculated by SEM image observation
  • the surface area of the copper particles contained in 1 g of the coated copper particles is represented by the following formula (c) from the formula (b).
  • the bonding state between the aliphatic carboxylic acid and the copper particles in the coated copper particles is not particularly limited, and may be an ionic bond or physical adsorption.
  • the aliphatic carboxylic acid is preferably physically adsorbed on the surface of the copper particle, and more preferably physically adsorbed on the surface of the copper particle with a carboxy group.
  • the physical adsorption of the aliphatic carboxylic acid to the copper particles can be confirmed by analyzing the surface composition of the coated copper particles. Specifically, Tof-SIMS surface analysis is performed on the coated copper particles, and only substantially free aliphatic carboxylic acid is detected, and aliphatic carboxylic acid bonded to 63 Cu or 65 Cu is substantially detected. It can be confirmed by not being done.
  • the fact that the aliphatic carboxylic acid bonded to 63 Cu or 65 Cu is not substantially detected means that the detected amount is 5% or less with respect to the detected amount of only the free aliphatic carboxylic acid. This means that it is preferably 1% or less.
  • the fact that the aliphatic carboxylic acid is physically adsorbed on the surface of the copper particle by a carboxy group is that the coated copper particle is subjected to infrared absorption spectrum measurement, and a stretching vibration peak substantially derived from the carboxylic acid-metal salt. It can be confirmed that only the stretching vibration peak derived from the free carboxylic acid is not substantially observed.
  • the particle diameter of the coated copper particles is not particularly limited and can be appropriately selected depending on the purpose and the like.
  • the average primary particle diameter of the coated copper particles is, for example, 0.02 ⁇ m or more and 5.0 ⁇ m or less, 0.02 ⁇ m or more and 1.0 ⁇ m or less, 0.02 ⁇ m or more and 0.5 ⁇ m or less, It can be 0.02 ⁇ m or more and 0.2 ⁇ m or less.
  • the average primary particle diameter of the coated copper particles is calculated as an arithmetic average value D SEM of primary particle diameters of arbitrary 20 coated copper particles by SEM observation.
  • the value of the variation coefficient (standard deviation SD / average primary particle diameter D SEM ) of the particle size distribution of the coated copper particles is, for example, 0.01 to 0.5, and preferably 0.05 to 0.3.
  • the variation coefficient of the particle size distribution is small, and the particle diameter can be made uniform. Since the coefficient of variation of the particle size distribution of the coated copper particles is small, the effect of being excellent in dispersibility and producing a high-concentration dispersion is obtained.
  • the ratio D XRD / D SEM to the average primary particle diameter D SEM by SEM observation of the crystal particle diameter D XRD obtained from powder X-ray measurement is, for example, 0.25 to 1.00, 0.5 to 1.00 is preferred.
  • the difference between the crystal particle diameter and the average primary particle diameter can be reduced by being manufactured by the method for manufacturing coated copper particles described later. As a result, the effect of better oxidation resistance and improved sinterability can be obtained.
  • the coated copper particles are excellent in oxidation resistance.
  • the excellent oxidation resistance can be confirmed, for example, by the fact that the production of copper oxide and copper hydroxide in the coated copper particles is suppressed after a predetermined time from production.
  • the total content of copper oxide and copper hydroxide in the coated copper particles after 2 months from the production is preferably 5% by mass or less, and more preferably 3% by mass or less.
  • the formation of copper oxide in the coated copper particles can be confirmed by XRD measurement of the coated copper particles.
  • coated copper particles of this embodiment are excellent in oxidation resistance and sinterability, they can be suitably used for conductive compositions that form wiring patterns and the like on a substrate. Details of the conductive composition containing the coated copper particles will be described later.
  • the method for producing the coated copper particles is not particularly limited as long as the desired coated copper particles are obtained.
  • the method for producing the coated copper particles preferably includes thermally decomposing the aliphatic carboxylic acid copper complex.
  • the structure of the aliphatic carboxylate copper complex applied to the method for producing coated copper particles is not particularly limited as long as the desired coated copper particles are obtained.
  • the aliphatic carboxylate copper complex is preferably formed from a reaction solution containing copper formate, amino alcohol, aliphatic carboxylic acid and a solvent, and copper formate, amino alcohol, a fatty acid having an aliphatic group having 5 or more carbon atoms. More preferably, it is formed from a reaction solution containing an aromatic carboxylic acid and a solvent.
  • the aliphatic carboxylate copper complex By subjecting the aliphatic carboxylate copper complex to thermal decomposition treatment, copper ions are reduced to produce metallic copper particles. Next, the aliphatic carboxylic acid is physically adsorbed on the surface of the generated metal copper particles, for example, so that a coating layer containing the aliphatic carboxylic acid having a predetermined coating density is formed, and desired coated copper particles are obtained. .
  • the method for producing coated copper particles includes a reaction liquid containing copper formate, amino alcohol, aliphatic carboxylic acid having an aliphatic group having 5 or more carbon atoms, and a solvent prior to thermally decomposing the aliphatic carboxylic acid copper complex.
  • the ⁇ SP value which is the difference in SP value between the amino alcohol and the solvent, is more preferably 4.2 or more. That is, the method for producing coated copper particles includes obtaining a reaction solution containing copper formate, amino alcohol, aliphatic carboxylic acid having an aliphatic group having 5 or more carbon atoms and a solvent, and forming a complex compound in the reaction solution.
  • a method for producing particles is particularly preferred.
  • the thermal decomposition and reduction reaction of the copper formate complex proceeds in the liquid phase, and as the reaction proceeds, amino alcohol that is incompatible with this is released from the copper formate complex into the reaction solvent.
  • a new reaction field similar to Water-in-Oil Emulsion is formed, in which copper nuclei are continuously generated, while the nucleus growth reaction proceeds, resulting in excellent oxidation resistance and sinterability. It is considered that reduced copper particles having a controlled particle size and uniform particle size are produced.
  • supply of a solute is controlled by appropriately controlling the thermal decomposition rate of the copper formate complex. Thereby, it is considered that the growth of metal nuclei is controlled and reduced copper particles having a more uniform particle size are generated.
  • the presence of the aliphatic carboxylic acid in the liquid phase is considered to cover the reduced copper particles generated by the aliphatic carboxylic acid by physical adsorption at a high density.
  • the coated copper particles produced in this way are composed of reduced copper particles with almost no oxide film, and the surface is coated with aliphatic carboxylic acid by physical adsorption, so it has an excellent balance between oxidation resistance and sinterability. Yes.
  • the aliphatic carboxylic acid which is an organic protective agent coating the copper particles, is removed at a temperature of 400 ° C. or less, and it is not necessary to use a reducing atmosphere such as hydrogen gas.
  • the coated copper particles can be sintered together.
  • conventional copper particles that require a reducing atmosphere for sintering can be used effectively even at sites where application is difficult, for example, where hydrogen embrittlement or alteration due to reaction with hydrogen is a problem. can do.
  • it can sinter using existing facilities, such as a nitrogen substitution reflow furnace, and is excellent also in terms of economy.
  • the reaction liquid used in the method for producing coated copper particles is copper formate, at least one amino alcohol, and at least one aliphatic carboxylic acid (preferably an aliphatic group having an aliphatic group having 5 or more carbon atoms). Carboxylic acid) and a solvent are preferably included.
  • the reaction solution may further contain other additives as required.
  • Copper formate is composed of divalent copper ions and 2 moles of formate ions per 1 mole of copper ions. Copper formate may be anhydrous or hydrated. In addition, copper formate may be a commercially available product or a newly prepared one. A method for thermally reducing copper formate to obtain fine particles of reduced copper is disclosed in, for example, Japanese Patent Publication No. 61-19682. Formic acid is different from ordinary carboxylic acid and has reducibility. Therefore, when copper formate is thermally decomposed, divalent copper ions can be reduced. For example, anhydrous copper formate is known to thermally decompose at 210 to 250 ° C. to produce metallic copper when heated in an inert gas.
  • the content of copper formate in the reaction solution is not particularly limited and can be appropriately selected according to the purpose and the like.
  • the content of copper formate in the reaction solution is, for example, preferably from 1.0 mol / liter to 2.5 mol / liter, and from 1.5 mol / liter to 2.5 mol from the viewpoint of production efficiency.
  • / L or less is more preferable, and 2.0 mol / L or more and 2.5 mol / L or less is particularly preferable.
  • the amino alcohol is an alcohol compound having at least one amino group, and is not particularly limited as long as it can form a complex compound with copper formate. Due to the presence of amino alcohol in the reaction solution, a complex compound can be formed from copper formate and solubilized in a solvent.
  • the amino alcohol is preferably a monoamino monoalcohol compound, and more preferably a monoamino monoalcohol compound in which the amino group is unsubstituted.
  • the amino alcohol is also preferably a monodentate monoamino monoalcohol compound.
  • the boiling point of amino alcohol is not particularly limited, but is preferably higher than the reaction temperature of the thermal decomposition treatment. Specifically, the boiling point of amino alcohol is preferably 120 ° C. or higher, and more preferably 130 ° C. or higher.
  • the upper limit of the boiling point is not particularly limited, and is, for example, 400 ° C. or lower, preferably 300 ° C. or lower.
  • the amino alcohol has an SP value of preferably 11.0 or more, more preferably 12.0 or more, and further preferably 13.0 or more from the viewpoint of polarity.
  • the upper limit of the SP value of aminoalcohol is not particularly limited, and is, for example, 18.0 or less, preferably 17.0 or less.
  • the SP value is the square root of the intermolecular bond energy E 1 per 1 mL of the sample at 25 ° C. according to the definition of Hildebrand.
  • the SP value was calculated by the method described on the “Japan Petroleum Institute website” (http://sekiyu-gakkai.or.jp/jp/dictionary/petdicsolvent.html#solubility2). Specifically, it is calculated as follows.
  • Intermolecular bonding energy E 1 is a value obtained by subtracting the gas energy from the latent heat of vaporization.
  • the latent heat of vaporization Hb is given by the following equation as the boiling point Tb of the sample.
  • Hb 21 ⁇ (273 + Tb) From this Hb value, the molar latent heat of vaporization H 25 at 25 ° C. is obtained by the following equation.
  • H 25 Hb ⁇ [1 + 0.175 ⁇ (Tb ⁇ 25) / 100]
  • Molar latent heat of vaporization H 25 intermolecular bonding energy E from is determined by the following equation.
  • E H 25 -596
  • Intermolecular bonding energy E 1 per sample 1mL from intermolecular bonding energy E is calculated by the following equation.
  • E 1 E ⁇ D / Mw
  • D the density of the sample
  • Mw the molecular weight of the sample
  • SP value is obtained from E 1 by the following equation.
  • SP (E 1 ) 1/2 Note that a solvent containing OH groups needs to be corrected by +1 for each OH group. [For example, Mitsubishi Oil Technology, No. 42, p3, p11 (1989)]
  • amino alcohols include 2-aminoethanol (boiling point: 170 ° C., SP value: 14.54), 3-amino-1-propanol (boiling point: 187 ° C., SP value: 13.45), 5-amino -1-pentanol (boiling point: 245 ° C., SP value: 12.78), DL-1-amino-2-propanol (boiling point: 160 ° C., SP value: 12.74), N-methyldiethanolamine (boiling point: 247) C., SP value: 13.26) and the like are exemplified, and at least one selected from the group consisting of these is preferable.
  • ⁇ Amino alcohol may be used alone or in combination of two or more.
  • the content of amino alcohol in the reaction solution is not particularly limited and can be appropriately selected according to the purpose and the like.
  • the content of amino alcohol is, for example, preferably in the range of 1.5 to 4.0 moles, more preferably in the range of 1.5 to 3.0 moles with respect to the copper ions in the reaction solution.
  • the content of amino alcohol is 1.5 times mol or more with respect to copper ions, sufficient solubility of copper formate can be obtained, and the time required for the reaction can be shortened.
  • the contamination of the produced coated copper particles can be suppressed when the amount is 4.0 times mol or less.
  • the aliphatic carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose and the like. Among these, from the viewpoint of oxidation resistance, an aliphatic carboxylic acid having an aliphatic group having 5 or more carbon atoms (hereinafter also referred to as “long-chain carboxylic acid”) is preferable.
  • the aliphatic group may be linear or branched, and may be either a saturated aliphatic group or an unsaturated aliphatic group.
  • the aliphatic group has 5 or more carbon atoms, preferably 5 or more and 17 or less, and more preferably 7 or more and 17 or less.
  • the variation rate that serves as an index of the particle size distribution tends to be small. This can be explained, for example, by the fact that the length of the carbon chain is highly correlated with the magnitude of the van der Waals force that determines the associating force.
  • carboxylic acids having a long carbon chain have a strong associative power and contribute to stabilization of the phase similar to the water-in-oil emulsion which is a micro reaction field, so that copper particles having a uniform particle diameter can be efficiently produced. It is done.
  • the boiling point of the aliphatic carboxylic acid is preferably higher than the temperature of the thermal decomposition treatment.
  • the boiling point of the aliphatic carboxylic acid is preferably 120 ° C. or higher, and more preferably 130 ° C. or higher.
  • the upper limit of the boiling point is not particularly limited, and is, for example, 400 ° C. or lower. There exists a tendency for the sinterability of a covering copper particle to improve more that a boiling point is 400 degrees C or less.
  • aliphatic carboxylic acid examples include oleic acid, linoleic acid, stearic acid, heptadecanoic acid, lauric acid, and octanoic acid, and are preferably at least one selected from the group consisting of these.
  • the aliphatic carboxylic acid may be used alone or in combination of two or more.
  • the content of the aliphatic carboxylic acid in the reaction solution is not particularly limited as long as desired coated copper particles are obtained.
  • the content of the aliphatic carboxylic acid is, for example, preferably in the range of 2.5 to 25 mol%, more preferably in the range of 5.0 to 15 mol% with respect to the copper ions in the reaction solution. There exists a tendency which can suppress the viscosity raise of a reaction system as content of aliphatic carboxylic acid is 25 mol% or less with respect to a copper ion.
  • the solvent constituting the reaction solution is preferably selected such that it does not excessively inhibit the reduction reaction with formic acid and the ⁇ SP value, which is the difference in SP value from amino alcohol, is 4.2 or more, and is usually used. It can be suitably selected from organic solvents.
  • the ⁇ SP value which is the difference between the SP value of the amino alcohol and the SP value of the solvent, is 4.2 or more, the coated copper particles having a narrow particle size distribution and a uniform particle diameter are formed. can get.
  • the ⁇ SP value is preferably 4.5 or more, more preferably 5.0 or more, from the viewpoint of reaction field formability and the quality of the coated copper particles.
  • the upper limit of the ⁇ SP value is not particularly limited.
  • the ⁇ SP value is 11.0 or less, and preferably 10.0 or less.
  • the SP value of the solvent is more preferably smaller than amino alcohol.
  • the SP value of the solvent is preferably 11.0 or less, and more preferably 10.0 or less.
  • the lower limit of the SP value of the solvent is not particularly limited.
  • the SP value of the solvent is preferably 7.0 or more.
  • the boiling point of the solvent is preferably higher than the temperature of the thermal decomposition treatment.
  • the boiling point of the solvent is preferably 120 ° C. or higher, and more preferably 130 ° C. or higher.
  • the upper limit of the boiling point is not particularly limited, and for example, the boiling point is 400 ° C. or lower, and preferably 300 ° C. or lower.
  • the solvent is also preferably an organic solvent capable of forming an azeotrope with water. If an azeotropic mixture with water can be formed, the water generated in the reaction solution by the thermal decomposition treatment can be easily removed from the reaction system.
  • the solvent examples include ethylcyclohexane (boiling point: 132 ° C., SP value: 8.18), C9 cyclohexane [manufactured by Maruzen Petroleum, trade name: Swaclean # 150] (boiling point: 149 ° C., SP value). : 799), n-octane (boiling point: 125 ° C., SP value: 7.54) and the like, and at least one selected from the group consisting of these is preferable.
  • the solvent may be used alone or in combination of two or more.
  • the solvent is a combination of two or more, it is preferable to include a main solvent that is not compatible with amino alcohol and an auxiliary solvent that is compatible with amino alcohol.
  • the main solvent are as described above.
  • a preferred embodiment of the boiling point of the auxiliary solvent is the same as that of the main solvent.
  • the SP value of the auxiliary solvent is preferably larger than that of the main solvent, and more preferably large enough to be compatible with amino alcohol.
  • the auxiliary solvent include glycol ethers such as EO glycol ether, PO glycol ether, and dialkyl glycol ether.
  • EO glycol ethers such as methyl diglycol, isopropyl glycol, butyl glycol
  • PO glycol ethers such as methyl propylene diglycol, methyl propylene triglycol, propyl propylene glycol, butyl propylene glycol, dimethyl diglycol, etc. And at least one selected from the group consisting of these is preferred.
  • cosolvents are all available from Nippon Emulsifier Co., Ltd.
  • the SP value of the solvent is calculated as an average SP value considering the SP value and molar volume of each solvent contained in the solvent.
  • the average SP value is calculated by the following equation when the solvent is composed of two kinds of solvent 1 and solvent 2.
  • ⁇ 3 [V 1 ⁇ ⁇ 1 + V 2 ⁇ ⁇ 2 ] / (V 1 + V 2 ) ⁇ 3 : average SP value of mixed solvent, ⁇ 1 : SP value of solvent 1, V 1 : molar volume of solvent 1, ⁇ 2 : SP value of solvent 2, V 2 : molar volume of solvent 2
  • the amount of solvent contained in the reaction solution is preferably selected so that the concentration of copper ions is 1.0 to 2.5 mol / liter, preferably 1.5 to 2.5 mol / liter. More preferably.
  • concentration of copper ions is 1.0 to 2.5 mol / liter or more, productivity is further improved, and when it is 2.5 mol / liter or less, an increase in the viscosity of the reaction solution is suppressed, and good stirring is achieved. Sex is obtained.
  • a complex compound derived from copper formate is generated.
  • the structure of a complex compound is not specifically limited, It may consist of 1 type and may contain 2 or more types.
  • the composition of the complex compound present in the reaction solution may change as the thermal decomposition treatment proceeds. That is, the complex compound mainly present in the early stage of the thermal decomposition treatment and the complex compound mainly present in the later stage of the thermal decomposition treatment may have different configurations.
  • the complex compound produced in the reaction solution preferably contains copper ions and formate ions and amino alcohols as ligands. By including amino alcohol as a ligand, the thermal decomposition temperature of the complex compound is lowered.
  • the complex compound produced in the reaction solution is a complex compound in which two molecules of formate ion and two molecules of amino alcohol are coordinated to one copper ion, and one molecule of formate ion to one copper ion. And a complex compound in which one molecule of an aliphatic carboxylic acid and two molecules of an amino alcohol are coordinated.
  • the complex compound preferably contains an aliphatic carboxylic acid copper complex formed from copper formate, amino alcohol and aliphatic carboxylic acid at least at the initial stage of the thermal decomposition treatment.
  • the complex compound produced in the reaction solution produces metallic copper by thermal decomposition treatment. What is necessary is just to select the temperature of a thermal decomposition process suitably according to the structure of a complex compound, etc.
  • the thermal decomposition temperature of copper formate is about 220 ° C., but copper formate forms a complex compound with amino alcohol, and as described in, for example, JP-A-2008-013466, the heat The decomposition temperature is considered to be about 110 ° C to 120 ° C. Therefore, the temperature of the pyrolysis treatment is preferably 100 ° C. to 130 ° C., more preferably 110 ° C. to 130 ° C. When the temperature of the thermal decomposition treatment is 130 ° C. or lower, the formation of acid amides due to the dehydration reaction between the aliphatic carboxylic acid and amino alcohol is suppressed, and the washability of the resulting coated copper particles tends to be improved.
  • Metallic copper is produced by the thermal decomposition treatment of the complex compound, and the coated copper particles whose surface is coated with the aliphatic carboxylic acid are adsorbed on the surface of the produced metallic copper by adsorbing the aliphatic carboxylic acid present in the reaction solution. Obtainable.
  • the adsorption of the aliphatic carboxylic acid on the surface of metallic copper is preferably physical adsorption. This improves the sinterability of the coated copper particles. By suppressing the formation of copper oxide in the thermal decomposition treatment of the complex compound, physical adsorption of the aliphatic carboxylic acid is promoted.
  • the thermal decomposition treatment it is preferable to remove at least a part of the water generated with the thermal decomposition reaction of the complex compound. By removing water in the thermal decomposition treatment, the production of copper oxide can be suppressed more efficiently.
  • the method for removing water is not particularly limited, and can be appropriately selected from conventionally used water removal methods. For example, it is preferable to remove the water produced by azeotropy using an organic solvent capable of forming an azeotrope with water as the solvent.
  • the time for the pyrolysis treatment may be appropriately selected according to the temperature of the pyrolysis treatment. For example, it can be 30 minutes to 180 minutes.
  • the atmosphere for the pyrolysis treatment is preferably an inert atmosphere such as a nitrogen atmosphere.
  • factors that control the particle size distribution of the produced coated copper particles include, for example, the type and amount of aliphatic carboxylic acid, the concentration of copper formate complex, and the ratio of the mixed solvent (main solvent / auxiliary Solvent) and the like.
  • Factors that control the size of the coated copper particles can be matched by appropriately maintaining the heating rate that governs the number of metal nuclei generated, that is, the stirring rate related to the amount of heat input to the reaction system and the size of the micro reaction field. it can.
  • the method for producing coated copper particles is a simple operation of preparing a reaction solution containing copper formate, amino alcohol, aliphatic carboxylic acid and a solvent, and performing a thermal decomposition treatment at a desired temperature. It is possible to efficiently produce coated copper particles having excellent properties and sinterability.
  • coated copper particles having a narrow particle size distribution are obtained.
  • This can be considered as follows, for example. That is, by setting the ⁇ SP value, which is the difference in SP value between the amino alcohol as a complexing agent for solubilizing copper formate in the reaction solvent and the solvent, to 4.2 or more, for example, the copper formate amino alcohol complex or In the state of a copper formate amino alcohol complex in which one molecule of formic acid is substituted with an aliphatic carboxylic acid, it is dissolved, but when the complex is thermally decomposed and amino alcohol as a complexing agent is released, the released amino alcohol is It cannot be compatible with the solvent and begins to form two phases.
  • the released amino alcohol has a high affinity with copper formate and copper formate amino alcohol complex, behaves as a new complexing agent or solvent of copper formate, forms a highly polar inner core (droplet), A two-phase structure similar to Water in oil Emulsion surrounded by a low-polarity solvent is assumed, and this is presumed to function as a microreaction field.
  • water in the reaction system and formic acid eliminated by substitution of the aliphatic carboxylic acid are also present in this microreaction field.
  • the metal nucleus, its growing particles, and the copper formate amino alcohol complex that is the source of the metal nucleus, the copper formate amino alcohol complex in which one molecule of formic acid is replaced with an aliphatic carboxylic acid, water and formic acid are sequestered.
  • the reaction proceeds.
  • the aliphatic carboxylic acid is immobilized as a coating material for the copper metal growth particles and decreases, the thermal decomposition mechanism of the copper formate complex progresses in the reaction formulas 1 to 3 described later. The process proceeds by this mechanism, and the generated gas component changes.
  • CuO is produced by hydrolysis of the copper formate amino alcohol complex with water shown in Reaction Formula 5, but is reduced again via Reaction Formula 6 or Reaction Formula 7, so cuprous oxide or copper oxide.
  • the copper particle which does not contain can be manufactured. Further, since the number of copper atoms contained in the micro reaction field is limited, the particle diameter of the copper particles is controlled to be constant.
  • the method for producing coated copper particles may further include a washing step, a separation step, a drying step, and the like of the coated copper particles after the thermal decomposition treatment.
  • a washing process of covering copper particles a washing process by an organic solvent can be mentioned, for example.
  • the organic solvent used in the washing step include alcohol solvents such as methanol and ketone solvents such as acetone. These may be used alone or in combination of two or more.
  • the conductive composition of the present embodiment includes at least one kind of the above-described coated copper particles and a medium.
  • the conductive composition can be suitably used for forming a wiring pattern, a bonding layer, and the like, and can easily form a wiring pattern, a bonding layer, and the like that are excellent in conductivity at a low temperature.
  • the configuration of the medium contained in the conductive composition can be appropriately selected according to the purpose of the conductive composition.
  • examples of the medium include hydrocarbon solvents, higher alcohol solvents, cellosolve, cellosolve acetate solvents, and the like.
  • the solid content concentration of the conductive composition for screen printing can be set to 40 to 95% by mass, for example.
  • the solid content of the conductive composition means the total amount of nonvolatile components.
  • examples of the medium include hydrocarbon solvents, higher alcohol solvents, cellosolve, cellosolve acetate solvents, and the like.
  • the solid content concentration of the conductive composition for inkjet printing can be set to 40 to 90% by mass, for example.
  • the conductive composition may further contain other additives as required in addition to the coated copper particles and the medium.
  • additives include coupling agents such as silane coupling agents and titanate coupling agents, and dispersants such as polyester dispersants and polyacrylic acid dispersants.
  • the circuit formed product of this embodiment includes a base material and a wiring pattern or a bonding layer that is a heat-treated product of the conductive composition disposed on the base material.
  • the wiring pattern or the bonding layer is excellent in conductivity.
  • the degree of freedom in selecting a base material is large.
  • Examples of the material of the base material include polyimide film, glass, ceramics, and metal.
  • the thickness in particular of a base material is not restrict
  • the thickness of a base material can be 0.01 mm or more and 5 mm or less, for example.
  • the formation of the wiring pattern can be performed, for example, by applying the conductive composition on the base material so as to have a desired pattern and heat-treating the applied conductive composition.
  • the bonding layer is, for example, a region where the semiconductor element is disposed by die bonding, and the shape, size, thickness, and the like may be appropriately selected according to the purpose. That is, the circuit formed product can be manufactured by a manufacturing method including, for example, a step of preparing a base material, a step of applying a conductive composition on the base material, and a step of heat-treating the conductive composition.
  • the method for applying the conductive composition is not particularly limited, and can be performed by, for example, an inkjet printing method, a screen printing method, a flexographic printing method, a dispensing method, or the like.
  • the application amount of the conductive composition can be appropriately selected according to the purpose and the like.
  • the thickness after the heat treatment can be 1 ⁇ m or more and 100 ⁇ m or less.
  • the temperature of the heat treatment of the conductive composition can be, for example, 200 to 600 ° C., and preferably 200 to 450 ° C.
  • the heat treatment time can be, for example, 1 to 120 minutes, and is preferably 1 to 60 minutes.
  • the heat treatment atmosphere is preferably a low oxygen atmosphere. Examples of the low oxygen atmosphere include a nitrogen atmosphere and an argon atmosphere. Moreover, it is preferable that oxygen concentration is 1,000 ppm or less.
  • Measuring device FE-EPMA JXA-8510F manufactured by JEOL Measurement conditions: acceleration voltage: 6KV or 15KV Observation magnification: x10,000 to x75,000
  • XRD-6100 manufactured by Shimadzu Measurement conditions: Target: Cu Tube voltage: 40 KV, tube current: 30.0 mA
  • ⁇ Tof-SIMS time-of-flight secondary ion mass spectrometer measurement>
  • Measuring instrument PHI TRIFT IV type manufactured by ULVAC-PHI Measurement conditions: Primary ion species: Au, acceleration voltage: 30 KV
  • Samples for LC measurement were prepared as follows. 1 g of coated copper particles and 9 mL of acetonitrile were added to the sample bottle. 1 mL of 0.36 weight% hydrochloric acid aqueous solution was added there. This mixed solution was subjected to ultrasonic irradiation treatment for 30 minutes and stirred and mixed. After completion of the extraction process, the slurry was allowed to stand and solid-liquid separation was performed, and then the supernatant was collected. The supernatant was filtered through a 0.2 ⁇ m filter to obtain a sample for LC measurement.
  • Example 1 A 3000 mL glass four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a 75 mL Dean Stark tube, and a nitrogen introduction tube was placed in an oil bath.
  • the precipitate was transferred to a 500 mL eggplant flask while being washed with 550 g of methanol (manufactured by Kanto Chemical Co., Inc.). The mixture was allowed to stand for 30 minutes or longer, the supernatant was decanted, and the resulting precipitate was placed on a rotary evaporator and vacuum dried at 40 ° C. and 1 kPa or less. After completion of the vacuum drying, the pressure was released while cooling to room temperature and substituting with nitrogen to obtain 194 g of brown coated copper particles.
  • Example 2 In Example 1, 200 g of coated copper particles were obtained in the same manner as in Example 1 except that oleic acid was used instead of lauric acid.
  • Example 3 In Example 1, 200 g of coated copper particles were obtained in the same manner as in Example 1 except that stearic acid was used instead of lauric acid.
  • Example 4 In Example 1, 200 g of coated copper particles was obtained in the same manner as in Example 1 except that lauric acid was changed to 68.1 g and 3-amino-1-propanol was changed to 712 g.
  • Example 5 In Example 4, 200 g of coated copper particles were obtained in the same manner as in Example 4 except that the temperature increase rate was changed to about 0.5 ° C./min. A sample having an average primary particle size larger than that of Example 4 was obtained.
  • coated copper particles were synthesized as follows. 71.5 g (0.5 mol) of cuprous oxide (I) (manufactured by Furukawa Chemicals) as the copper compound, 15.0 g (250 mmol) of acetic acid as the coating material, hydrazine monohydrate as the reducing agent (Wako Pure Chemicals) [Manufactured by Kogyo Co., Ltd.] 25.0 g (0.5 mol) and 500 ml of isopropanol as a solvent were mixed and added to a 1,000 ml four-necked flask containing a condenser, a thermometer, a nitrogen inlet tube and a stirring device.
  • cuprous oxide (I) manufactured by Furukawa Chemicals
  • acetic acid 15.0 g (250 mmol)
  • hydrazine monohydrate as the reducing agent
  • 25.0 g (0.5 mol) and 500 ml of isopropanol as a solvent were mixed and added to a 1,000 ml
  • the coated copper particle dispersion was designated as Kiriyama Filter Paper No.
  • the powder was filtered off under reduced pressure with 5B.
  • the filtered powder was washed three times with methanol (manufactured by Kanto Chemical Co., Inc.), dried under reduced pressure at 40 ° C. and 1 kPa or less, cooled to room temperature, purged with nitrogen, and taken out to obtain 62 g of brown powder.
  • a surface-treated copper powder was obtained in the following manner according to the example of JP-A-2002-332502. Add 50 g of copper powder with an average primary particle size of 672 nm and 0.025 g of oleic acid (manufactured by NOF Corporation) in 50 g of methanol (manufactured by Kanto Chemical Co., Inc.), and stir and mix to form a surface treatment layer on the surface of the copper powder. did. Then, Kiriyama filter paper No. The powder was filtered off under reduced pressure with 5B.
  • the surface-treated copper powder is filtered and washed, dried under reduced pressure at 40 ° C. and 1 kPa or less, cooled to room temperature, purged with nitrogen, and taken out. 20 g of brown powder was obtained.
  • the crystal particle size was calculated from Scherrer's equation from the diffraction angle and half-value width of the powder X-ray. Scherrer's equation is expressed by equation (1).
  • D K ⁇ / ( ⁇ cos ⁇ ) (1)
  • ⁇ is a wavelength of a measured X-ray (CuK ⁇ : 1.5418 ⁇ )
  • ⁇ is expressed by Equation (2).
  • the ⁇ b ⁇ B (2)
  • b is the half width of the peak
  • the crystallite diameter D XRD of the coated copper particles was 31.3 nm. Since the average primary particle diameter D SEM calculated from the SEM observation result (FIG. 2) is 59.2 nm, the calculation of D XRD / D SEM gives 0.53, and the crystallite diameter relative to the average primary particle diameter is relatively large. I understand.
  • Tof-SIMS measurement was performed to examine the surface composition of the coated copper particles obtained in Example 1. According to the Tof-SIMS measurement result (FIG. 3), free lauric acid was detected almost quantitatively. Since lauric acid bonded to 63 Cu and 65 Cu was not detected, it was found that what is present on the surface of the coated copper particles is lauric acid that is coated by physical adsorption.
  • infrared absorption (IR) spectrum measurement was performed in order to examine how the lauric acid coating the surface of the copper particles adhered to the metal surface.
  • IR spectrum measurement result FIG. 4
  • only the stretching vibration peak derived from the carboxylic acid-metal salt was detected.
  • No stretching vibration peak of free carboxylic acid was observed, suggesting that lauric acid forms a monomolecular film and is physically adsorbed on the copper surface.
  • TG-DTA measurement was performed in order to examine the amount of organic components covering the surface of the coated copper particles obtained in Example 1 (FIG. 5). From the TG-DTA measurement results, it can be seen that the loss on heating is 1.79% by mass, and that almost all of it is desorbed near the boiling point of lauric acid. This result also suggests that lauric acid is physically adsorbed, and it is assumed that the coated copper particles can exhibit low-temperature sinterability.
  • M acid is heated loss measured mass values (g)
  • M W is the molecular lauric acid weight (g / mo l)
  • N A is the Avogadro constant (6.02 ⁇ 10 23 present / mol).
  • the number of particles in 1 g of copper particles is expressed by the following equation (4).
  • Number of particles in 1g] M Cu / [( 4 ⁇ r 3/3) ⁇ d ⁇ 10 -21] ⁇ (4)
  • M Cu is a calculated mass value (g) obtained from the measured heat loss
  • r is the radius (nm) of the primary particle diameter calculated by SEM observation
  • the particle surface area in 1 g of copper particles is represented by the formula (5) using the formula (4).
  • the coating density of lauric acid in the coated copper particles was 4.83 molecules / nm 2 .
  • the minimum area is calculated from the van der waals radius of the stearic acid molecule from “Chemistry and Education, Vol. 40, No. 2, (1992) Obtaining the cross-sectional area of the stearic acid molecule—experimental values and calculated values—”.
  • the theoretical value of the saturated covered area converted from is about 5.00 molecules / nm 2 . From this theoretical value, it is presumed that the coated copper particles of this embodiment have lauric acid adsorbed on the particle surface at a relatively high density. This dense coating effect can be considered as a reason why the lauric acid coating is excellent in oxidation resistance in spite of physical adsorption that is weaker than chemical adsorption.
  • Example 2 the coated copper particles obtained in Example 2 were evaluated in the same manner as described above. From the results of SEM observation (FIG. 6) and XRD measurement, the average primary particle size was 65.7 nm, and the crystallite size was 33.9 nm. Further, according to the IR spectrum measurement result (FIG. 7), only the stretching vibration peak derived from the carboxylic acid-metal salt was detected. Since no stretching vibration peak of free carboxylic acid was observed, it is suggested that oleic acid forms a monomolecular film and is physically adsorbed on the copper surface. From the TG-DTA measurement results, it was found that the weight loss on heating was 1.68% by mass, and almost all was eliminated near the boiling point of oleic acid. LC measurement was performed. According to the results of LC measurement, oleic acid was mainly detected as the organic component.
  • the coating density of oleic acid covering the surfaces of the copper particles was calculated in the same manner as described above, and it was 3.53 molecules / nm 2 .
  • Oleic acid is an unsaturated fatty acid having a double bond, and has a molecular structure bent at the position of this double bond. Compared with a saturated fatty acid such as lauric acid, when oleic acid forms a monomolecular film, it tends to form a liquid expansion film due to its steric hindrance. From "Science of Emulsion (V) by Tetsuya Hanai” (Cooking Science, Vol. 7, No.
  • the coating density of oleic acid in the surface membrane model on the water surface is It can be calculated as about 1.25 molecules / nm 2 .
  • the coated copper particles produced in Example 2 had a relatively high density coating effect and formed a monomolecular film close to a liquid aggregated film.
  • the coating density of oleic acid coating the surface of the copper particles was calculated in the same manner as described above, and was 1.17 molecule / nm 2 .
  • Example 1 Evaluation of oxidation resistance
  • FIG. 9 shows the results of the powder X-ray measurement immediately after production in Comparative Example 1 and the same measurement results after storage for 2 months at 25 ° C. in an air atmosphere. As shown in FIG. 9, in the coated copper particles produced under the conditions of Comparative Example 1, a signal derived from cuprous oxide was clearly observed after 2 months.

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Cited By (4)

* Cited by examiner, † Cited by third party
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WO2019146412A1 (ja) * 2018-01-26 2019-08-01 日清エンジニアリング株式会社 銀微粒子の製造方法および銀微粒子
WO2019146411A1 (ja) * 2018-01-26 2019-08-01 日清エンジニアリング株式会社 微粒子の製造方法および微粒子
KR20220099976A (ko) 2019-11-18 2022-07-14 닛신 엔지니어링 가부시키가이샤 미립자의 제조 장치 및 미립자의 제조 방법
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Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111344815A (zh) * 2017-11-13 2020-06-26 京瓷株式会社 膏组合物、半导体装置以及电气/电子部件
JP6892120B2 (ja) * 2017-11-28 2021-06-18 協立化学産業株式会社 被覆金属粒子、導電性組成物、導電体、接合用積層体、回路形成物及び焼結体の製造方法
EP3718661A4 (en) * 2017-11-29 2021-06-09 National University Corporation Hokkaido University LOW TEMPERATURE SINTERABLE COPPER PARTICLE AND METHOD FOR MANUFACTURING A SINTERED COMPACT USING THE SAME
JP6818359B2 (ja) * 2018-03-19 2021-01-20 協立化学産業株式会社 導電性ペースト組成物、導電体、導電性ペースト組成物の塗工方法、及び導電体の製造方法
JP7380256B2 (ja) * 2020-01-28 2023-11-15 三菱マテリアル株式会社 接合用シート
JP7121884B1 (ja) 2021-03-29 2022-08-19 三菱マテリアル株式会社 銅粒子及びその製造方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008013837A (ja) * 2006-07-10 2008-01-24 Sumitomo Metal Mining Co Ltd 微小銅粉及びその製造方法
JP2008013466A (ja) * 2006-07-04 2008-01-24 Seiko Epson Corp ギ酸銅錯体、銅粒子の製造方法および配線基板の製造方法
JP2011032558A (ja) * 2009-08-04 2011-02-17 Harima Chemicals Inc 金属銅微粒子の製造方法
JP2012226841A (ja) * 2011-04-15 2012-11-15 Fukuda Metal Foil & Powder Co Ltd 銅超微粒子分散ペーストおよび導電膜の形成方法
JP2013159830A (ja) * 2012-02-06 2013-08-19 Toyota Central R&D Labs Inc 表面被覆金属ナノ粒子、およびその製造方法

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1061579C (zh) * 1995-03-08 2001-02-07 上海市合成树脂研究所 电磁屏蔽导电涂料用铜粉的制备方法
US7393586B2 (en) * 2001-04-27 2008-07-01 Dowa Electronics Materials Co., Ltd. Highly oxidation-resistant copper powder for conductive paste and process for producing the powder
JP3890205B2 (ja) 2001-05-10 2007-03-07 三井金属鉱業株式会社 銅ペースト用の表面処理銅粉、その表面処理銅粉の製造方法、その表面処理銅粉を用いた銅ペースト及びその銅ペーストを用いたプリント配線板
JP4195581B2 (ja) 2002-05-27 2008-12-10 三井金属鉱業株式会社 銅粉の製造方法及びその方法で得られた銅粉
JP4530617B2 (ja) 2003-01-23 2010-08-25 三井金属鉱業株式会社 銅ペースト用の銅粉の製造方法及びその製造方法により得られる銅ペースト用の銅粉
EP1660243A4 (en) * 2003-07-09 2011-11-16 Fry Metals Inc ÜBERZUGSMETALLTEILCHEN
CN101232963B (zh) * 2005-07-25 2011-05-04 住友金属矿山株式会社 铜微粒分散液及其制造方法
KR100814295B1 (ko) * 2006-10-10 2008-03-18 삼성전기주식회사 구리 나노입자의 제조방법 및 그에 의해 제조된 구리나노입자
CN100556584C (zh) * 2007-03-26 2009-11-04 中南大学 一种导电浆料用铜粉的表面修饰方法
WO2009060803A1 (ja) * 2007-11-05 2009-05-14 Sumitomo Metal Mining Co., Ltd. 銅微粒子とその製造方法及び銅微粒子分散液
JP6241908B2 (ja) * 2011-02-04 2017-12-06 国立大学法人山形大学 被覆金属微粒子とその製造方法
JP5848552B2 (ja) 2011-08-29 2016-01-27 日立金属株式会社 銅微粒子分散液の製造方法、銅微粒子の製造方法、銅微粒子分散液および銅微粒子
CN102601355A (zh) * 2012-03-20 2012-07-25 昆明理工大学 一种提高铜金粉耐腐蚀性的表面改性方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008013466A (ja) * 2006-07-04 2008-01-24 Seiko Epson Corp ギ酸銅錯体、銅粒子の製造方法および配線基板の製造方法
JP2008013837A (ja) * 2006-07-10 2008-01-24 Sumitomo Metal Mining Co Ltd 微小銅粉及びその製造方法
JP2011032558A (ja) * 2009-08-04 2011-02-17 Harima Chemicals Inc 金属銅微粒子の製造方法
JP2012226841A (ja) * 2011-04-15 2012-11-15 Fukuda Metal Foil & Powder Co Ltd 銅超微粒子分散ペーストおよび導電膜の形成方法
JP2013159830A (ja) * 2012-02-06 2013-08-19 Toyota Central R&D Labs Inc 表面被覆金属ナノ粒子、およびその製造方法

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019146412A1 (ja) * 2018-01-26 2019-08-01 日清エンジニアリング株式会社 銀微粒子の製造方法および銀微粒子
WO2019146411A1 (ja) * 2018-01-26 2019-08-01 日清エンジニアリング株式会社 微粒子の製造方法および微粒子
CN111819018A (zh) * 2018-01-26 2020-10-23 日清工程株式会社 微粒子的制造方法及微粒子
JPWO2019146412A1 (ja) * 2018-01-26 2021-01-07 日清エンジニアリング株式会社 銀微粒子の製造方法および銀微粒子
JPWO2019146411A1 (ja) * 2018-01-26 2021-01-07 日清エンジニアリング株式会社 微粒子の製造方法および微粒子
JP7090651B2 (ja) 2018-01-26 2022-06-24 日清エンジニアリング株式会社 銀微粒子の製造方法および銀微粒子
JP7282691B2 (ja) 2018-01-26 2023-05-29 日清エンジニアリング株式会社 微粒子の製造方法
US11691200B2 (en) 2018-01-26 2023-07-04 Nisshin Engineering Inc. Silver fine particle production method and silver fine particles
KR20220099976A (ko) 2019-11-18 2022-07-14 닛신 엔지니어링 가부시키가이샤 미립자의 제조 장치 및 미립자의 제조 방법
CN115348907A (zh) * 2020-03-31 2022-11-15 三井金属矿业株式会社 铜颗粒及其制造方法

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