WO2011114579A1 - Method for producing low-melting-point metal nanoparticles - Google Patents

Method for producing low-melting-point metal nanoparticles Download PDF

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WO2011114579A1
WO2011114579A1 PCT/JP2010/070565 JP2010070565W WO2011114579A1 WO 2011114579 A1 WO2011114579 A1 WO 2011114579A1 JP 2010070565 W JP2010070565 W JP 2010070565W WO 2011114579 A1 WO2011114579 A1 WO 2011114579A1
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point metal
low
melting
melting point
metal nanoparticles
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PCT/JP2010/070565
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French (fr)
Japanese (ja)
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雄一 石川
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Ｄｏｗａホールディングス株式会社
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/02—Making metallic powder or suspensions thereof using physical processes
    • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
    • B22F2009/042—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling using a particular milling fluid
    • 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
    • B22F2301/30—Low melting point metals, i.e. Zn, Pb, Sn, Cd, In, Ga
    • 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
    • B22F2303/00—Functional details of metal or compound in the powder or product
    • B22F2303/01—Main component

Definitions

  • the present invention relates to a method for producing low melting point metal nanoparticles having a fine particle size.
  • metal particles have a different particle size and exhibit characteristics different from those of bulk metals when the particle size becomes several tens of nanometers (10 ⁇ 9 m) or less.
  • the melting point is drastically lowered as compared with that in a bulk state. Therefore, in the case of metal particles having a particle size of submicron (over 0.1 ⁇ m), even if the metal particles are only melted at high temperature, the temperature is lower in the case of metal particles having a particle size of several tens of nanometers or less. It can be melted by heating. Utilizing this property, silver nanoparticles (silver particles having an average particle diameter of several tens of nanometers) that can be melted at a low temperature to form a metal wiring have been put into practical use.
  • a metal wiring can be formed by pasting the silver nanoparticle powder, creating a conductive paste, and applying and firing. In this case, in order to obtain a highly conductive metal wiring, firing is performed. It was necessary to set the temperature to about 120 ° C. or higher.
  • a conductive paste that can be sintered at a low temperature of less than 100 ° C., preferably about 80 ° C. or less can be produced by a simple method, its application can be expected to be significantly expanded.
  • an inexpensive antenna in which fine wiring is drawn on a PET (polyethylene terephthalate) substrate having a low glass transition temperature, an IC tag using paper as a material, and the like can be realized more easily.
  • Patent Document 1 discloses a method in which an indium gas is brought into contact with a low vapor pressure liquid.
  • Patent Document 1 can obtain nanoparticles of indium, which is a low melting point metal
  • the environment in which indium is used as a gas and in contact with the low vapor pressure liquid is set to a high vacuum of 10 ⁇ 1 Pa or less. Need expensive equipment. Further, since a high vacuum container is required, it is considered that it is not easy to scale up, and there is room for improvement in terms of manufacturing cost and productivity.
  • an object of the present invention is to provide a method for producing low melting point metal nanoparticles that can produce low melting point metal nanoparticles without the need for a high vacuum vessel and can obtain alloy nanopowder with a stable metal composition ratio.
  • a metal having a melting point of 25 ° C. or higher (solid at room temperature) and 300 ° C. or lower is referred to as a low melting point metal.
  • the present inventors put a solid or liquid low melting point metal, a non-aqueous solvent, and a grinding ball having a diameter of 0.015 mm to 5 mm in a container. Obtaining a mixture, heating the mixture within a temperature range from 5 ° C. to 20 ° C.
  • a low melting point metal nanoparticle having an average particle size of 3 nm or more and less than 50 nm is obtained. Knowing that particles can be obtained, the present invention has been completed.
  • a step of obtaining a mixture by placing a solid or liquid low melting point metal, a non-aqueous solvent, and a pulverizing ball having a diameter of 0.015 mm to 5 mm in a container; Is heated from the melting point of the low melting point metal to -5 ° C. to the melting point of the low melting point metal + 20 ° C., and the ball for pulverization is separated from the mixture after stirring to obtain a low melting point metal nanoparticle and a non-aqueous system.
  • a method for producing a low-melting-point metal nanoparticle comprising a step of obtaining a solvent mixture and a step of obtaining a low-melting-point metal nanoparticle by solid-liquid separation of the low-melting-point metal nanoparticle and non-aqueous solvent mixture.
  • the low-melting-point metal may be one or more selected from the group of In, Ga, Bi, and Sn.
  • the non-aqueous solvent may be an organic solvent having an aldehyde group or a hydroxy group.
  • the non-aqueous solvent may be an organic solvent containing at least one of a primary amino group, a secondary amino group, or a tertiary amino group.
  • the stirring step may be performed by rotating a stirring blade at a peripheral speed of 200 cm / second to 200000 cm / second.
  • the solid-liquid separation may be performed by centrifugation.
  • the mixture of the low-melting-point metal nanoparticles and the non-aqueous solvent may be subjected to solid-liquid separation, and then the low-melting-point metal nanoparticles may be washed with an organic solvent having a boiling point of 150 ° C. or lower.
  • the volume of the metal may be 0.1 volume% to 20 volume% of the volume of the non-aqueous solvent.
  • low melting point metal nanoparticles that can produce low melting point metal nanoparticles having an average particle size of less than 50 nm without the need for a high vacuum container, and can obtain alloy nanopowder with a stable metal composition ratio. It is in providing the manufacturing method of.
  • Example 1 of this invention It is a figure which shows the measurement result in Example 1 of this invention. It is a figure which shows the observation result in Example 1 of this invention.
  • Metal composition of low melting point metal nanoparticles As the metal composition of the low melting point metal nanoparticles in the present invention, it is possible to use a metal having a melting point in the range of 25 ° C. to 300 ° C. and an alloy of the metal. Specific examples of the metal element include In, Ga, Bi, Sn, and alloys composed of two or more of these metals. These metals or alloys have a low melting point, which is advantageous in applying the production method of the present invention that is stirred in a solvent.
  • the metal or alloy may contain other metal elements as required, as long as the melting point is not outside the range of 25 ° C. to 300 ° C.
  • the average particle size of the low melting point metal nanoparticles is preferably 3 nm or more and less than 50 nm. In the case of 50 nm or more, the sintering temperature may not be sufficiently lowered, and the low melting point metal nanoparticles of less than 3 nm have a high surface activity and may cause problems due to alteration such as oxidation. From the viewpoint of sufficiently lowering the sintering temperature, the average particle size of the low melting point metal nanoparticles is more preferably less than 30 nm, and even more preferably 20 nm or less.
  • low-melting-point metal nanoparticles having an average particle size of less than 50 nm can be produced through the following steps (1) to (4).
  • ⁇ Raw metal> As the raw metal of the low melting point metal nanoparticles, for example, an alloy composed of In, Ga, Bi, Sn, and two or more of these metals having the same metal composition as the low melting point metal nanoparticles to be obtained is used. can do.
  • the non-aqueous solvent in the present invention preferably has a boiling point equal to or higher than the melting point of the raw metal (bulk).
  • the melting point of the non-aqueous solvent is preferably 156.6 ° C. or higher.
  • the non-aqueous solvent has a melting point of 271.3 ° C.
  • a nonaqueous solvent having a boiling point higher by 10 ° C. or higher than the melting point of the raw material metal (bulk) is particularly suitable, and a solvent having a boiling point of 20 ° C. or higher is particularly suitable.
  • a pressure vessel is used as a vessel for stirring.
  • the boiling point is desirably higher by 10 ° C. or more than the melting point of the raw material metal (bulk) to be obtained.
  • a solvent having a reducing property is more preferable.
  • an alcohol solvent having a boiling point in the range of 150 ° C. to 400 ° C. is an example of such a non-aqueous solvent.
  • the non-aqueous solvent includes a monohydric alcohol or a dihydric alcohol glycol.
  • the monohydric alcohol include butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, decyl alcohol, nonyl alcohol, cyclopentanol, benzyl alcohol, and cinnamyl alcohol.
  • glycol solvents include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, benzpinacol, hydro Benzoyl, cyclopentadiol, cyclohexanediol, cyclohexanediol, glycolic acid amide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monoethyl ether, diethylene glycol dibutyl ether, acetic acid diethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, etc.
  • glycol solvents include glycerin, ethylene glycol, diethylene glycol, triethylene glyco
  • glycols and diols are preferable because they have two hydroxyl groups and thus have polarity and contribute to the dispersibility of the powder.
  • examples of such a solvent include —CH2-CHOH, or —CHR—CHOH, —CR1R2-CHOH, ⁇ CHCHOH, ⁇ CRCHOH (R, R1, R2: side chain) in the molecule, and the solvent Has a boiling point of at least 100 ° C. or higher.
  • an organic compound having an aldehyde group —CHO has the same effect.
  • Examples include aliphatic aldehydes such as succindialdehyde, aliphatic unsaturated aldehydes such as crotonaldehyde, and aromatic aldehydes such as benzaldehyde, tolualdehyde, salicylaldehyde, and cinnamaldehyde. And naphthaldehyde, and the heterocyclic aldehyde includes furfural.
  • aliphatic aldehydes such as succindialdehyde
  • aliphatic unsaturated aldehydes such as crotonaldehyde
  • aromatic aldehydes such as benzaldehyde, tolualdehyde, salicylaldehyde, and cinnamaldehyde.
  • naphthaldehyde, and the heterocyclic aldehyde includes furfural.
  • amine-based reducing solvents examples include hexylamine, hebutinamine, octylamine, undecylamine, tridecylamine, tetradecylamine, pentadecylamine, cetylamine, dibutylamine, diamylamine, cyclohexylamine, aniline, naphthylamine, and toluidine. is there.
  • ⁇ Crushing ball> As the grinding balls used in the present invention, alumina balls, zirconia balls, mullite balls, glass balls, metal stainless steel balls or iron balls using ceramics as materials can be used, and the material is not particularly limited. However, zirconia and alumina are particularly suitable as the material for the ball for pulverization, which has the advantages of high durability and low mixing of impurities into the low melting point metal nanoparticles.
  • the grinding balls preferably have a particle size of 0.015 mm to 5 mm. If only pulverizing balls having a particle diameter of more than 5 mm are used, it becomes difficult to obtain low melting point metal nanoparticles having a desired fine particle diameter. If only pulverizing balls having a particle diameter of less than 0.015 mm are used, stirring is performed. Subsequent solid-liquid separation may take time. In order to easily obtain a low melting point metal nanoparticle having a smaller particle diameter, the particle diameter of the ball for pulverization is more preferably 0.05 to 3 mm, further preferably 0.1 to 1 mm, and 0.1 to 0.00. 5 mm is even more preferable.
  • the large ball size need not be particularly concerned with the particle size of 5 mm, and may be, for example, a particle size of 10 mm. It is necessary that at least 50% by mass of grinding balls having a particle diameter of 0.015 mm to 5 mm is contained.
  • a diamond-like carbon (DLC) or a compound such as B, C, or N, which is a material to which a low melting point metal hardly adheres, can be formed on the surface of the grinding ball.
  • the volume ratio of the mixture is preferably 0.05% by volume to 20% by volume, and more preferably 0.1% by volume to 10% by volume with respect to the volume of the non-aqueous solvent used.
  • the grinding balls are preferably 20% by volume to 600% by volume with respect to the volume of the non-aqueous solvent used.
  • the metal raw material is less than 0.1% by volume, the productivity is low, and when it exceeds 20% by volume, the particle size of the obtained low melting point metal nanoparticles may not be sufficiently small.
  • the pulverizing ball is less than 20% by volume, the resulting low melting point metal nanoparticles may not have a sufficiently small particle size.
  • the surface of the pulverizing ball contains a large amount of raw material metal. It may become attached.
  • the volume ratio of the grinding ball to the non-aqueous solvent is set so that the height of the top surface of the grinding ball and the top surface of the non-aqueous solvent are substantially the same. The adjustment is more preferable because low melting point metal nanoparticles can be easily obtained.
  • the atmosphere for heating and stirring is preferably an inert gas or a reducing gas.
  • the atmosphere is air, a thick oxide film may be formed on the surface of the generated low melting point metal nanoparticles, and it is preferable that the oxygen concentration in the atmosphere is low.
  • the inert gas include nitrogen and argon
  • the reducing gas include hydrogen or a mixed gas of hydrogen and an inert gas.
  • the heating temperature of the mixture may be higher than the melting point of the metal raw material (bulk) to be used, but it may be heated to a temperature 5 ° C. lower than the melting point to 20 ° C. higher than the melting point. preferable. More preferably, the temperature may be the same temperature as the melting point to 15 ° C. higher than the melting point. More preferably, the temperature may be 5 ° C. higher than the melting point to 10 ° C. higher than the melting point.
  • the heating temperature is set to a temperature lower than the boiling point of the non-aqueous solvent to be used (in the case of heating and stirring under pressure, the boiling point under pressure).
  • Stirring can be performed by rotating a stirring blade, and may be performed using a pulverizer that can use pulverizing balls such as a mill.
  • the pulverization conditions such as the number of revolutions may be appropriately selected according to the content of the mixture and the average particle diameter of the low melting point metal nanoparticles to be obtained, and can be obtained by increasing the number of revolutions of the stirring blade and the like.
  • the average particle diameter of the melting point metal nanoparticles can be reduced.
  • the rotation speed can be set in the range of 100 to 100,000 rpm
  • the peripheral speed of the stirring blade can be set in the range of 100 to 5000 cm / sec.
  • Solid-liquid separation of the mixture of the low-melting-point metal nanoparticles obtained in the above step and the non-aqueous solvent is performed. Solid-liquid separation can be performed by centrifugation. In addition, when the used non-aqueous solvent does not have a trouble as a dispersion medium of a low melting-point metal nanoparticle, it does not necessarily need to perform solid-liquid separation. In the solid obtained by the solid-liquid separation, agglomerates of low melting point metal nanoparticles may be present. In this case, aggregation can be dispersed by dispersing the solid in a solvent and irradiating with ultrasonic waves.
  • the ultrasonic irradiation can be performed for 1 minute or longer using an ultrasonic cleaning apparatus.
  • the treatment can be performed for 1 minute to 1 hour.
  • dispersing the solid in a solvent and centrifuging under a condition of about 500 rpm to 1500 rpm agglomerated low melting point metal nanoparticles can be separated.
  • the solid-liquid separated metal nanoparticles can be washed with a solvent.
  • a solvent is an organic solvent of alcohol having a low boiling point such as methanol or ethanol.
  • the powder is dried by a method that does not perform high-temperature heating such as vacuum drying, whereby low-melting-point metal nanoparticle powders with little residual non-aqueous solvent used can be obtained.
  • low melting point metal nanoparticles were produced by the method for producing low melting point metal nanoparticles according to the present invention, and the produced low melting point metal nanoparticles were measured and observed. Further, as Comparative Examples 1 and 2, the requirement of the present invention is that the mixture is heated and stirred at the melting point of the low melting point metal, which is the material of the mixture, from ⁇ 5 ° C. to the melting point of the low melting point metal + 20 ° C. Attempts were made to produce low-melting-point metal nanoparticles in a state that was changed outside the scope of the present invention.
  • Example 1 10 g of 6N indium was weighed, and this indium was put into a 500 mL separable flask. As a result of measuring the melting point of indium with a differential scanning calorimeter (DSC) (Thermoplus DSC8230, manufactured by Rigaku Corporation), the melting point was 157 ° C. Next, 1 kg of 0.3 mm ⁇ zirconia balls was charged into the separable flask, and 300 mL of tetraethylene glycol was further charged to obtain a mixture. Thereafter, the upper lid of the separable flask was sealed and sealed, and nitrogen gas was allowed to flow at 100 mL / min to perform gas replacement for 10 minutes.
  • DSC differential scanning calorimeter
  • the mixture was heated to 161 ° C. (heating temperature) in a state where stirring was performed by rotating a stirring blade made of stainless steel having a rotational diameter of 6 cm, which had been installed in the separable flask, by rotating 700 rpm.
  • the temperature of the mixture was measured with a thermocouple installed in a separable flask.
  • the mixture was cooled at a cooling rate of 5 ° C./min while maintaining the stirring state.
  • the mixture became 40 ° C. or lower, the rotation of the stirring blade was stopped.
  • the mixture was then passed through a mesh of 250 mesh nylon fabric to separate 0.3 mm ⁇ zirconia balls from the mixture. On the filtered side, a solvent (tetraethylene glycol) in which the low melting point metal nanoparticles were dispersed was recovered.
  • the solvent in which the low-melting-point metal nanoparticles are dispersed is centrifuged at 3500 rpm for 3 hours to perform solid-liquid separation, and the supernatant liquid is removed to recover the solid content. did. Thereafter, cleaning was performed in the following manner.
  • the collected solid content is stirred and mixed with 500 mL of ethanol for 1 hour, redispersed, centrifuged at 3500 rpm for 3 hours and solid-liquid separation, and the operation of removing the supernatant liquid is repeated 3 times. A solid content containing a small amount of was obtained.
  • FIG. 2 shows the result of drying this dispersion and observing it with a TEM (transmission electron microscope, 400,000 magnifications). It was found that nanoparticles of around 8 nm were generated.
  • the average particle diameter of the low melting point metal nanoparticles was determined from the TEM image obtained above.
  • TEM transmission electron microscope
  • 50 independent particle diameters (major axis diameters) that do not overlap are measured to calculate an average particle diameter.
  • the average particle size results are shown in Table 1.
  • Example 2 The production and measurement of low melting point metal nanoparticles were attempted in the same manner as in Example 1 except that the heating temperature was changed from 161 ° C to 156 ° C and 166 ° C. Table 1 shows the average particle size of the obtained low melting point metal nanoparticles. The results of X-ray diffraction were the same as in Example 1 at 156 ° C. and 166 ° C.
  • Example 1 The production of low melting point metal nanoparticles was attempted in the same manner as in Example 1 except that the heating temperature was changed from 161 ° C. to 150 ° C. and 180 ° C. When large particles of In particles were formed and the mixture was passed through a mesh of 250 mesh nylon fabric, it could hardly pass through and low melting point metal nanoparticles were not obtained.
  • Example 3 The production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 1 except that the raw material metal used was changed from 6N indium to 6N gallium and the heating temperature was changed from 161 ° C to 35 ° C. Table 2 shows the average particle diameter of the obtained low melting point metal nanoparticles. As a result of X-ray diffraction, a peak corresponding to the Ga peak position was confirmed.
  • Example 4 Except for changing the heating temperature from 35 ° C. to 29 ° C. and 40 ° C., production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 3. Table 2 shows the average particle diameter of the obtained low melting point metal nanoparticles.
  • Example 2 The production of low melting point metal nanoparticles was attempted in the same manner as in Example 3 except that the heating temperature was changed from 35 ° C. to 24 ° C. and 50 ° C. When Ga particles having large particle sizes were formed and the mixture was passed through a mesh of 250 mesh nylon fabric, it was hardly possible to pass through the mixture, and low melting point metal nanoparticles were not obtained.
  • Example 5 The production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 1 except that the raw material metal used was changed from 6N indium to bismuth and the heating temperature was changed from 161 ° C to 276 ° C. Table 3 shows the average particle size of the obtained low-melting-point metal nanoparticles. As a result of X-ray diffraction, a peak corresponding to the Bi peak position was confirmed.
  • Example 6 The production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 5 except that the heating temperature was changed from 276 ° C. to 271 ° C. and 281 ° C. Table 3 shows the average particle size of the obtained low-melting-point metal nanoparticles.
  • the present invention can be applied to a method for producing low melting point metal nanoparticles having a fine particle size.

Abstract

Provided is a method for producing low-melting-point metal nanoparticles, which can produce low-melting-point metal nanoparticles without using a high-vacuum container and which can produce alloy nanoparticles having a stable metal composition ratio. Specifically, provided is a method for producing low-melting-point metal nanoparticles, which involves: a step for obtaining a mixture by placing a solid or liquid low-melting-point metal, a non-water-based solvent, and pulverization balls having a diameter of 0.015mm to 5mm in a container; a step for stirring and heating the aforementioned mixture between the temperatures of -5°C to +20°C of the melting point of the aforementioned low-melting-point metal; a step for separating the aforementioned pulverization balls from the stirred mixture, and for obtaining a mixture of low-melting-point metal nanoparticles and the non-water-based solvent; and a step for performing solid-liquid separation on the mixture of the low-melting-point nanoparticles and the non-water-based solvent, and for obtaining low-melting-point nanoparticles.

Description

低融点金属ナノ粒子の製造方法Method for producing low melting point metal nanoparticles
　本発明は、粒径が微細である低融点金属ナノ粒子の製造方法に関する。 The present invention relates to a method for producing low melting point metal nanoparticles having a fine particle size.
　一般に金属粒子は粒径を小さくし、粒径が、数十ナノメートル（１０－９ｍ）以下になると、バルク金属とは異なる特性を発現することが知られている。特に、金属粒子の場合は、融点がバルク状態のものに比べ劇的に低下することが知られている。そのため、粒径がサブミクロン（０．１μｍ超）である金属粒子では、高温でしか溶融しなかったようなものでも、粒径が、数十ナノメートル以下の金属粒子の場合には、より低温に加熱することで、溶融させることができる。この性質を利用して、低温で溶融し、金属配線を形成することができる銀ナノ粒子（平均粒径が数十ナノメートルの銀粒子）が実用化されている。 In general, it is known that metal particles have a different particle size and exhibit characteristics different from those of bulk metals when the particle size becomes several tens of nanometers (10 −9 m) or less. In particular, in the case of metal particles, it is known that the melting point is drastically lowered as compared with that in a bulk state. Therefore, in the case of metal particles having a particle size of submicron (over 0.1 μm), even if the metal particles are only melted at high temperature, the temperature is lower in the case of metal particles having a particle size of several tens of nanometers or less. It can be melted by heating. Utilizing this property, silver nanoparticles (silver particles having an average particle diameter of several tens of nanometers) that can be melted at a low temperature to form a metal wiring have been put into practical use.
前記の銀ナノ粒子粉末をペースト化し、導電性ペーストを作成し、塗布・焼成することにより、金属配線を形成することができるが、この場合、導電性の高い金属配線を得るためには、焼成温度を１２０℃程度以上とすることが必要であった。 A metal wiring can be formed by pasting the silver nanoparticle powder, creating a conductive paste, and applying and firing. In this case, in order to obtain a highly conductive metal wiring, firing is performed. It was necessary to set the temperature to about 120 ° C. or higher.
もし、１００℃未満、好ましくは８０℃程度以下の低い温度で焼結させることのできる導電性ペーストが簡便な手法で生産可能になれば、その用途は著しく拡大することが期待できる。例えば、ガラス転位温度が低いＰＥＴ（ポリエチレンテレフタレート）基板上に微細配線を描画した安価なアンテナや、紙を素材にしたＩＣタグなども、より容易に実現可能になると考えられる。さらに、導電性高分子へ直接金属配線を描画することも可能になると考えられ、各種電極材等の用途が広がることが期待される。 If a conductive paste that can be sintered at a low temperature of less than 100 ° C., preferably about 80 ° C. or less, can be produced by a simple method, its application can be expected to be significantly expanded. For example, an inexpensive antenna in which fine wiring is drawn on a PET (polyethylene terephthalate) substrate having a low glass transition temperature, an IC tag using paper as a material, and the like can be realized more easily. Furthermore, it is considered that it is possible to draw a metal wiring directly on a conductive polymer, and it is expected that applications of various electrode materials will be expanded.
銀ナノ粒子粉末を用いた導電ペーストでは、バルクとしての銀の融点が高いために、導電性の高い金属配線を得るために必要な焼結温度を更に低下させることは困難であることが予想される。更に低い温度で焼結させることのできる導電性ペーストを得る方法として、低融点金属のナノ粒子粉末を導電性ペーストに配合することが考えられる。低融点金属のナノ粒子を得る方法として、特許文献１にインジウム類の気体を低蒸気圧液体に接触させる方法が開示されている。 In the conductive paste using silver nanoparticle powder, the melting point of silver as a bulk is high, so it is expected that it is difficult to further lower the sintering temperature necessary to obtain highly conductive metal wiring. The As a method for obtaining a conductive paste that can be sintered at a lower temperature, it is conceivable to mix a low melting point metal nanoparticle powder into the conductive paste. As a method for obtaining low melting point metal nanoparticles, Patent Document 1 discloses a method in which an indium gas is brought into contact with a low vapor pressure liquid.
特開２００９－２４０９６８号公報JP 2009-240968 A
　しかしながら、上記特許文献１の方法では、低融点金属であるインジウムのナノ粒子を得ることができるが、インジウムを気体とし、低蒸気圧液体に接触させる環境を、１０－１Ｐａ以下の高真空とする必要があり、高価な設備を必要とする。また、高真空容器が必要なことから、スケールアップすることが容易ではないと考えられ、製造コスト、生産性の点で改善の余地があった。また、２種類以上の金属元素を含む合金のナノ粒子を製造しようとする場合、固体または液体の金属を気体とする際に、安定した金属元素組成比をもつ金属気体を得ることが難しく、金属組成比の安定した合金ナノ粉末の得ることが困難であると考えられた。 However, although the method of Patent Document 1 can obtain nanoparticles of indium, which is a low melting point metal, the environment in which indium is used as a gas and in contact with the low vapor pressure liquid is set to a high vacuum of 10 −1 Pa or less. Need expensive equipment. Further, since a high vacuum container is required, it is considered that it is not easy to scale up, and there is room for improvement in terms of manufacturing cost and productivity. In addition, when producing nanoparticles of an alloy containing two or more kinds of metal elements, it is difficult to obtain a metal gas having a stable metal element composition ratio when a solid or liquid metal is used as a gas. It was considered difficult to obtain alloy nanopowder having a stable composition ratio.
そこで、本発明の目的は、低融点金属のナノ粒子を高真空容器を必要とせず製造でき、金属組成比の安定した合金ナノ粉末の得ることができる低融点金属ナノ粒子の製造方法を提供することにある。なお、本発明では、融点が２５℃以上（室温で固体）であり、３００℃以下である金属を低融点金属と称する。 Accordingly, an object of the present invention is to provide a method for producing low melting point metal nanoparticles that can produce low melting point metal nanoparticles without the need for a high vacuum vessel and can obtain alloy nanopowder with a stable metal composition ratio. There is. In the present invention, a metal having a melting point of 25 ° C. or higher (solid at room temperature) and 300 ° C. or lower is referred to as a low melting point metal.
　前記の目的を達成するため、本発明者らは、鋭意研究の結果、容器中に、固体または液体の低融点金属と、非水系溶媒と、直径０．０１５ｍｍ～５ｍｍの粉砕用ボールとを入れ、混合物を得て、前記混合物を前記低融点金属の融点と比較して５℃低い温度から２０℃高い温度範囲内に加熱し、攪拌した後、前記混合物から粉砕用ボールを分離して、低融点金属のナノ粒子と非水系溶媒の混合物を得て、前記低融点金属のナノ粒子と非水系溶媒の混合物を固液分離することにより、平均粒径３ｎｍ以上、５０ｎｍ未満の低融点金属のナノ粒子を得られることを知見し、本発明を完成するに至った。 In order to achieve the above-mentioned object, the present inventors, as a result of intensive studies, put a solid or liquid low melting point metal, a non-aqueous solvent, and a grinding ball having a diameter of 0.015 mm to 5 mm in a container. Obtaining a mixture, heating the mixture within a temperature range from 5 ° C. to 20 ° C. higher than the melting point of the low melting point metal, stirring, and then separating the grinding balls from the mixture to By obtaining a mixture of a melting point metal nanoparticle and a non-aqueous solvent and subjecting the mixture of the low melting point metal nanoparticle and the non-aqueous solvent to solid-liquid separation, a low melting point metal nanoparticle having an average particle size of 3 nm or more and less than 50 nm is obtained. Knowing that particles can be obtained, the present invention has been completed.
　かかる知見に基づく本発明によれば、容器中に、固体または液体の低融点金属と、非水系溶媒と、直径０．０１５ｍｍ～５ｍｍの粉砕用ボールとを入れ、混合物を得る工程と、前記混合物を前記低融点金属の融点－５℃～前記低融点金属の融点＋２０℃に加熱し、攪拌する工程と、攪拌後の前記混合物から粉砕用ボールを分離して、低融点金属ナノ粒子と非水系溶媒の混合物を得る工程と、前記低融点金属ナノ粒子と非水系溶媒の混合物を固液分離して、低融点金属ナノ粒子を得る工程を有する、低融点金属ナノ粒子の製造方法が提供される。 According to the present invention based on such knowledge, a step of obtaining a mixture by placing a solid or liquid low melting point metal, a non-aqueous solvent, and a pulverizing ball having a diameter of 0.015 mm to 5 mm in a container; Is heated from the melting point of the low melting point metal to -5 ° C. to the melting point of the low melting point metal + 20 ° C., and the ball for pulverization is separated from the mixture after stirring to obtain a low melting point metal nanoparticle and a non-aqueous system. Provided is a method for producing a low-melting-point metal nanoparticle comprising a step of obtaining a solvent mixture and a step of obtaining a low-melting-point metal nanoparticle by solid-liquid separation of the low-melting-point metal nanoparticle and non-aqueous solvent mixture. .
　上記低融点金属ナノ粒子の製造方法において、前記低融点金属が、Ｉｎ、Ｇａ、Ｂｉ、Ｓｎの群から選択される１種以上であってもよい。また、前記非水系溶媒はアルデヒド基またはヒドロキシ基を有する有機溶媒であってもよい。また、前記非水系溶媒は一級アミノ基、または二級アミノ基、または三級アミノ基の内の少なくとも一種以上を含む有機溶媒であってもよい。 In the method for producing low-melting-point metal nanoparticles, the low-melting-point metal may be one or more selected from the group of In, Ga, Bi, and Sn. The non-aqueous solvent may be an organic solvent having an aldehyde group or a hydroxy group. The non-aqueous solvent may be an organic solvent containing at least one of a primary amino group, a secondary amino group, or a tertiary amino group.
　また、前記攪拌する工程は、攪拌羽根を周速２００ｃｍ／秒～２０００００ｃｍ／秒で回転させることにより行われてもよい。また、前記固液分離を遠心分離により行ってもよい。また、前記低融点金属のナノ粒子と非水系溶媒の混合物を固液分離した後、低融点金属のナノ粒子を沸点１５０℃以下の有機溶媒で洗浄してもよい。また、前記金属の体積が、前記非水系溶媒の体積の０．１体積％～２０体積％であってもよい。 Further, the stirring step may be performed by rotating a stirring blade at a peripheral speed of 200 cm / second to 200000 cm / second. The solid-liquid separation may be performed by centrifugation. The mixture of the low-melting-point metal nanoparticles and the non-aqueous solvent may be subjected to solid-liquid separation, and then the low-melting-point metal nanoparticles may be washed with an organic solvent having a boiling point of 150 ° C. or lower. The volume of the metal may be 0.1 volume% to 20 volume% of the volume of the non-aqueous solvent.
　本発明によれば、平均粒径が５０ｎｍ未満と小さい低融点金属のナノ粒子を高真空容器を必要とせず製造でき、金属組成比の安定した合金ナノ粉末の得ることができる低融点金属ナノ粒子の製造方法を提供することにある。 According to the present invention, low melting point metal nanoparticles that can produce low melting point metal nanoparticles having an average particle size of less than 50 nm without the need for a high vacuum container, and can obtain alloy nanopowder with a stable metal composition ratio. It is in providing the manufacturing method of.
本発明の実施例１における測定結果を示す図である。It is a figure which shows the measurement result in Example 1 of this invention. 本発明の実施例１における観察結果を示す図である。It is a figure which shows the observation result in Example 1 of this invention.
　以下、本発明の実施の形態について説明する。なお、本実施の形態は本発明を限定するものではない。 Hereinafter, embodiments of the present invention will be described. Note that this embodiment does not limit the present invention.
＜低融点金属ナノ粒子の金属組成＞
本発明における低融点金属ナノ粒子の金属組成としては、融点が２５℃～３００℃の範囲内である金属および前記金属の合金を用いることが可能である。具体的な金属元素としては、Ｉｎ、Ｇａ、Ｂｉ、Ｓｎ、とこれらの金属２種以上からなる合金が挙げられる。これらの金属または合金は低融点であり、溶媒中で攪拌する本発明の製造方法を適用する上で、有利である。前記の金属または合金は、必要に応じて、融点２５℃～３００℃の範囲外とならない範囲で、他の金属元素を含んでもよい。 <Metal composition of low melting point metal nanoparticles>
As the metal composition of the low melting point metal nanoparticles in the present invention, it is possible to use a metal having a melting point in the range of 25 ° C. to 300 ° C. and an alloy of the metal. Specific examples of the metal element include In, Ga, Bi, Sn, and alloys composed of two or more of these metals. These metals or alloys have a low melting point, which is advantageous in applying the production method of the present invention that is stirred in a solvent. The metal or alloy may contain other metal elements as required, as long as the melting point is not outside the range of 25 ° C. to 300 ° C.
＜低融点金属ナノ粒子の平均粒径＞
　低融点金属ナノ粒子の平均粒径は、３ｎｍ以上、５０ｎｍ未満であることが好ましい。５０ｎｍ以上の場合には、焼結温度を十分低くできない場合があり、３ｎｍ未満の低融点金属ナノ粒子は、表面活性が高く、酸化等の変質による問題が生じることがある。焼結温度を十分低くする観点から、低融点金属ナノ粒子の平均粒径は、３０ｎｍ未満とすることが更に好ましく、２０ｎｍ以下とすることが一層好ましい。 <Average particle size of low melting point metal nanoparticles>
The average particle size of the low melting point metal nanoparticles is preferably 3 nm or more and less than 50 nm. In the case of 50 nm or more, the sintering temperature may not be sufficiently lowered, and the low melting point metal nanoparticles of less than 3 nm have a high surface activity and may cause problems due to alteration such as oxidation. From the viewpoint of sufficiently lowering the sintering temperature, the average particle size of the low melting point metal nanoparticles is more preferably less than 30 nm, and even more preferably 20 nm or less.
本発明によれば、平均粒径５０ｎｍ未満の低融点金属ナノ粒子は、以下の（１）～（４）に示す工程を経ることにより、製造することができる。
（１）容器中に、固体または液体の金属と、非水系溶媒と、直径０．０１５ｍｍ～５ｍｍの粉砕用ボールとを入れ、混合物を得る工程。
（２）前記混合物を前記金属の融点より５℃低い温度（融点－５℃）～前記金属の融点よ
り２０℃高い温度（融点＋２０℃）に加熱し、攪拌する工程。
（３）前記混合物から粉砕用ボールを分離して、低融点金属ナノ粒子と非水系溶媒の混合物を得る工程。
（４）前記低融点金属ナノ粒子と非水系溶媒の混合物を固液分離して、低融点金属ナノ粒子を得る工程。
　必要に応じて、得られた低融点金属ナノ粒子に対して、洗浄、乾燥等を行ってもよい。 According to the present invention, low-melting-point metal nanoparticles having an average particle size of less than 50 nm can be produced through the following steps (1) to (4).
(1) A step of placing a solid or liquid metal, a non-aqueous solvent, and a grinding ball having a diameter of 0.015 mm to 5 mm in a container to obtain a mixture.
(2) A step of heating the mixture from a temperature 5 ° C. lower than the melting point of the metal (melting point −5 ° C.) to a temperature 20 ° C. higher than the melting point of the metal (melting point + 20 ° C.) and stirring.
(3) A step of separating the balls for grinding from the mixture to obtain a mixture of low melting point metal nanoparticles and a non-aqueous solvent.
(4) A step of obtaining a low melting point metal nanoparticle by solid-liquid separation of the mixture of the low melting point metal nanoparticle and the non-aqueous solvent.
As needed, you may perform washing | cleaning, drying, etc. with respect to the obtained low melting metal nanoparticle.
＜原料金属＞
　低融点金属ナノ粒子の原料金属としては、得ようとする低融点金属ナノ粒子と同一の金属組成を持つ、例えば、Ｉｎ、Ｇａ、Ｂｉ、Ｓｎ、とこれらの金属２種以上からなる合金を使用することができる。 <Raw metal>
As the raw metal of the low melting point metal nanoparticles, for example, an alloy composed of In, Ga, Bi, Sn, and two or more of these metals having the same metal composition as the low melting point metal nanoparticles to be obtained is used. can do.
＜非水系溶媒＞
本発明での非水系溶媒とはその沸点が、原料金属（バルク）の融点以上であるものが好適である。例えば、原料金属が、Ｉｎの場合には、非水系溶媒の融点は１５６．６℃以上が好適であり、例えば、原料金属が、Ｂｉの場合には、非水系溶媒の融点は２７１．３℃以上が好適である。非水系溶媒の沸点が、原料金属（バルク）の融点と比較して１０℃以上高いものが特に好適であり、２０℃以上高いものが特に好適である。後述するように、低融点金属ナノ粒子を得るためには、非水系溶媒として得ようとする低融点金属ナノ粒子の融点よりも高い沸点を持つものが好ましいが、攪拌をおこなう容器に圧力容器を用いることにより、雰囲気圧力を上げ、常圧の沸点が原料金属（バルク）の融点より低い非水系溶媒でも、使用が可能である。しかしながら製造装置に耐圧性能が必要となるので、沸点は、得ようとする原料金属（バルク）の融点よりも１０℃以上高いことが望ましい。更に非水系溶媒として、低融点金属ナノ粒子が酸素と反応して、表面に酸化物を形成しやすいために、還元性を有する溶媒であることが更に好ましい。 <Non-aqueous solvent>
The non-aqueous solvent in the present invention preferably has a boiling point equal to or higher than the melting point of the raw metal (bulk). For example, when the raw material metal is In, the melting point of the non-aqueous solvent is preferably 156.6 ° C. or higher. For example, when the raw metal is Bi, the non-aqueous solvent has a melting point of 271.3 ° C. The above is preferable. A nonaqueous solvent having a boiling point higher by 10 ° C. or higher than the melting point of the raw material metal (bulk) is particularly suitable, and a solvent having a boiling point of 20 ° C. or higher is particularly suitable. As will be described later, in order to obtain low-melting point metal nanoparticles, those having a boiling point higher than the melting point of the low-melting point metal nanoparticles to be obtained as the non-aqueous solvent are preferable, but a pressure vessel is used as a vessel for stirring. By using it, it is possible to use even a non-aqueous solvent in which the atmospheric pressure is increased and the boiling point of atmospheric pressure is lower than the melting point of the raw metal (bulk). However, since the pressure resistance performance is required for the production apparatus, the boiling point is desirably higher by 10 ° C. or more than the melting point of the raw material metal (bulk) to be obtained. Furthermore, as the non-aqueous solvent, since the low melting point metal nanoparticles react with oxygen and easily form an oxide on the surface, a solvent having a reducing property is more preferable.
例えば、このような非水系溶媒の一例として、沸点が１５０℃から４００℃の範囲のアルコール系溶媒が挙げられる。具体的には、非水系溶媒として、一価アルコール、または二価アルコールのグリコールがある。一価アルコールとしては、例えば、ブチルアルコール、アミルアルコール、ヘキシルアルコール、ヘプチルアルコール、オクチルアルコール、デシルアルコール、ノニルアルコール、シクロペンタノール、ベンジルアルコール、シンナミルアルコール等がある。グリコール系の溶媒としては、グリセリン、エチレングリコール、ジエチレングリコール、トリエチレングリコール、プロピレングリコール、トリメチレングリコール、ブタンジオール、ペンタンジオール、ヘキサンジオール、ヘプタンジオール、オクタンジオール、ノナンジオール、デカンジオール、ベンズピナコール、ヒドロベンゾイル、シクロペンダジオール、シクロヘキサンジオール、シクロヘキサンジオール、グリコール酸アミド、ジエチレングリコールジメチルエーテル、ジエチレングリコールジエチルエーテル、プロピレングリコールモノエチルエーテル、ジエチレングリコールジブチルエーテル、酢酸ジ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アセタート等があり、分子量の大きいものではポリエチレングリコール、ポリエチレングリコールエステル、ポリエチレングリコールエーテルがある。特にグリコール、ジオール系のものは水酸基を二つ持つものであるため、極性を持ち、粉の分散性に寄与するので望ましい。このような溶媒としては、例えば－ＣＨ２－ＣＨＯＨ、または－ＣＨＲ－ＣＨＯＨ、－ＣＲ１Ｒ２－ＣＨＯＨ、＝ＣＨＣＨＯＨ、＝ＣＲＣＨＯＨ（Ｒ、Ｒ１、Ｒ２：側鎖）を分子中に含まれるもので、且つ溶媒の沸点は少なくとも１００℃以上のものである。更にはアルデヒド基－ＣＨＯを持つ有機化合物も同様な効果を持ち、例えば、脂肪族飽和アルデヒドとして、ラウリンアルデヒド、トリデシルアルデヒド、ミリスチンアルデヒド、カプロンアルデヒド、ヘプトアルデヒド、ペンタデシルアルデヒド、パルミチンアルデヒド、マルガリンアルデヒド、ステアリンアルデヒドが挙げられ、脂肪族ジアルデヒドとしては例えばスクシンジアルデヒドがあり、脂肪族不飽和アルデヒドとして、クロトンアルデヒド、更には芳香族アルデヒドには、ベンズアルデヒド、トルアルデヒド、サリチルアルデヒド、シンナムアルデヒド、ナフトアルデヒド等があり、複素環式アルデヒドにはフルフラールが挙げられる。アミン系の還元性溶媒としては、ヘキシルアミン、ヘブチンアミン、オクチルアミン、ウンデシルアミン、トリデシルアミン、テトラデシルアミン、ペンタデシルアミン、セチルアミン、ジブチルアミン、ジアミルアミン、シクロヘキシルアミン、アニリン、ナフチルアミン、トルイジン等がある。 For example, an alcohol solvent having a boiling point in the range of 150 ° C. to 400 ° C. is an example of such a non-aqueous solvent. Specifically, the non-aqueous solvent includes a monohydric alcohol or a dihydric alcohol glycol. Examples of the monohydric alcohol include butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, decyl alcohol, nonyl alcohol, cyclopentanol, benzyl alcohol, and cinnamyl alcohol. Examples of glycol solvents include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, benzpinacol, hydro Benzoyl, cyclopentadiol, cyclohexanediol, cyclohexanediol, glycolic acid amide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monoethyl ether, diethylene glycol dibutyl ether, acetic acid diethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, etc. big Intended polyethylene glycol, polyethylene glycol esters, polyethylene glycol ethers. In particular, glycols and diols are preferable because they have two hydroxyl groups and thus have polarity and contribute to the dispersibility of the powder. Examples of such a solvent include —CH2-CHOH, or —CHR—CHOH, —CR1R2-CHOH, ═CHCHOH, ═CRCHOH (R, R1, R2: side chain) in the molecule, and the solvent Has a boiling point of at least 100 ° C. or higher. Furthermore, an organic compound having an aldehyde group —CHO has the same effect. Examples include aliphatic aldehydes such as succindialdehyde, aliphatic unsaturated aldehydes such as crotonaldehyde, and aromatic aldehydes such as benzaldehyde, tolualdehyde, salicylaldehyde, and cinnamaldehyde. And naphthaldehyde, and the heterocyclic aldehyde includes furfural. Examples of amine-based reducing solvents include hexylamine, hebutinamine, octylamine, undecylamine, tridecylamine, tetradecylamine, pentadecylamine, cetylamine, dibutylamine, diamylamine, cyclohexylamine, aniline, naphthylamine, and toluidine. is there.
＜粉砕用ボール＞
本発明に用いる粉砕用ボールとしては、材質としてセラミックス系を用いたアルミナボール、ジルコニアボール、ムライトボール、ガラスボール、金属系のステンレスボールや鉄ボール等を使用することができ、特に材質に制限はないが、粉砕用ボールの材質として、耐久性が高く、低融点金属ナノ粒子への不純物の混入が少ない利点のある、ジルコニア、アルミナが特に好適である。 <Crushing ball>
As the grinding balls used in the present invention, alumina balls, zirconia balls, mullite balls, glass balls, metal stainless steel balls or iron balls using ceramics as materials can be used, and the material is not particularly limited. However, zirconia and alumina are particularly suitable as the material for the ball for pulverization, which has the advantages of high durability and low mixing of impurities into the low melting point metal nanoparticles.
粉砕用ボールは、粒径が０．０１５ｍｍ～５ｍｍであることが好ましい。粒径５ｍｍ超の粉砕用ボールのみを使用すると、目的とする微細な粒径を持つ低融点金属ナノ粒子を得ることが難しくなり、粒径０．０１５ｍｍ未満の粉砕用ボールのみを使用すると、攪拌後の固液分離に時間を要することがある。より粒径の小さい低融点金属ナノ粒子を容易に得るためには、粉砕用ボールの粒径は、０．０５～３ｍｍが更に好ましく、０．１～１ｍｍが一層好ましく、０．１～０．５ｍｍが更に一層好ましい。粉砕用ボールを大きな粒径のものと小さな粒径のものとを組み合わせて使用することも可能である。この場合には、大きなボールサイズは特に粒径５ｍｍにこだわる必要はなく、例えば、粒径１０ｍｍでも良い。少なくとも粒径０．０１５ｍｍ～５ｍｍの粉砕用ボールが５０質量％入っていることが必要である。 The grinding balls preferably have a particle size of 0.015 mm to 5 mm. If only pulverizing balls having a particle diameter of more than 5 mm are used, it becomes difficult to obtain low melting point metal nanoparticles having a desired fine particle diameter. If only pulverizing balls having a particle diameter of less than 0.015 mm are used, stirring is performed. Subsequent solid-liquid separation may take time. In order to easily obtain a low melting point metal nanoparticle having a smaller particle diameter, the particle diameter of the ball for pulverization is more preferably 0.05 to 3 mm, further preferably 0.1 to 1 mm, and 0.1 to 0.00. 5 mm is even more preferable. It is also possible to use a pulverizing ball in combination of a large particle size and a small particle size. In this case, the large ball size need not be particularly concerned with the particle size of 5 mm, and may be, for example, a particle size of 10 mm. It is necessary that at least 50% by mass of grinding balls having a particle diameter of 0.015 mm to 5 mm is contained.
粉砕用ボールの表面に、低融点金属が付着しにくい材質であるダイヤモンドライクカーボン（ＤＬＣ）やＢ，Ｃ，Ｎ等の化合物を形成することができる。 A diamond-like carbon (DLC) or a compound such as B, C, or N, which is a material to which a low melting point metal hardly adheres, can be formed on the surface of the grinding ball.
＜混合物の体積比＞
前記混合物の体積比は、用いる非水系溶媒の体積に対して、金属原料は、０．０５体積％～２０体積％が好ましく、０．１体積％～１０体積％が一層好ましい。粉砕用ボールは、用いる非水系溶媒の体積に対して、２０体積％～６００体積％が好ましい。金属原料が０．１体積％未満の場合、生産性が低くなり、２０体積％超の場合には、得られる低融点金属ナノ粒子の粒径が十分小さくならないことがある。粉砕用ボールが２０体積％未満の場合には、得られる低融点金属ナノ粒子の粒径が十分小さくならないことがあり、６００体積％超の場合は、粉砕用ボールの表面に原料用金属が多く付着した状態となることがある。前記混合物を容器中で静置したときに、前記粉砕用ボールの上面と前記非水系溶媒の上面の高さが、略同一となるように、前記粉砕用ボールの前記非水系溶媒に対する体積比率を調整することにより、低融点金属ナノ粒子が得やすくなるので、更に好ましい。 <Volume ratio of the mixture>
The volume ratio of the mixture is preferably 0.05% by volume to 20% by volume, and more preferably 0.1% by volume to 10% by volume with respect to the volume of the non-aqueous solvent used. The grinding balls are preferably 20% by volume to 600% by volume with respect to the volume of the non-aqueous solvent used. When the metal raw material is less than 0.1% by volume, the productivity is low, and when it exceeds 20% by volume, the particle size of the obtained low melting point metal nanoparticles may not be sufficiently small. When the pulverizing ball is less than 20% by volume, the resulting low melting point metal nanoparticles may not have a sufficiently small particle size. When the pulverizing ball exceeds 600% by volume, the surface of the pulverizing ball contains a large amount of raw material metal. It may become attached. When the mixture is allowed to stand in a container, the volume ratio of the grinding ball to the non-aqueous solvent is set so that the height of the top surface of the grinding ball and the top surface of the non-aqueous solvent are substantially the same. The adjustment is more preferable because low melting point metal nanoparticles can be easily obtained.
＜加熱・攪拌工程＞
前記金属原料と、前記非水系溶媒と、前記粉砕用ボールの混合物を加熱・攪拌することにより、平均粒径が３ｎｍ以上、５０ｎｍ未満である低融点金属ナノ粒子を生成することができる。 <Heating and stirring process>
By heating and stirring the mixture of the metal raw material, the non-aqueous solvent, and the ball for grinding, low melting point metal nanoparticles having an average particle size of 3 nm or more and less than 50 nm can be generated.
加熱・攪拌する雰囲気は、不活性ガスまたは還元性ガスとすることが好ましい。雰囲気を空気とした場合、生成した低融点金属ナノ粒子の表面に厚い酸化膜が生成することがあり、雰囲気中の酸素濃度は低いほうが好ましい。不活性ガスとしては、窒素、アルゴン等が挙げられ、還元性ガスとしては、水素または水素と不活性ガスの混合ガスが挙げられる。 The atmosphere for heating and stirring is preferably an inert gas or a reducing gas. When the atmosphere is air, a thick oxide film may be formed on the surface of the generated low melting point metal nanoparticles, and it is preferable that the oxygen concentration in the atmosphere is low. Examples of the inert gas include nitrogen and argon, and examples of the reducing gas include hydrogen or a mixed gas of hydrogen and an inert gas.
加熱・攪拌する際、混合物の加熱温度は、使用する金属原料（バルク）の融点より高い温度とすればよいが、前記融点より５℃低い温度～前記融点より２０℃高い温度に加熱することが好ましい。より好ましくは、前記融点と同じ温度～前記融点より１５℃高い温度とすればよい。また、さらに好ましくは、前記融点より５℃高い温度～前記融点より１０℃高い温度とすればよい。使用する原料金属（バルク）の融点近傍の温度で加熱・攪拌を行うことで低融点金属ナノ粒子の収率（低融点金属ナノ粒子収量／金属原料投入量）が好適なものとなる。前記加熱温度は、使用する非水系溶媒の沸点（加圧下で加熱・攪拌する場合には、該加圧下での沸点）未満の温度とする。 When heating and stirring, the heating temperature of the mixture may be higher than the melting point of the metal raw material (bulk) to be used, but it may be heated to a temperature 5 ° C. lower than the melting point to 20 ° C. higher than the melting point. preferable. More preferably, the temperature may be the same temperature as the melting point to 15 ° C. higher than the melting point. More preferably, the temperature may be 5 ° C. higher than the melting point to 10 ° C. higher than the melting point. By heating and stirring at a temperature in the vicinity of the melting point of the raw material metal (bulk) to be used, the yield of the low melting point metal nanoparticles (low melting point metal nanoparticle yield / metal raw material input amount) becomes suitable. The heating temperature is set to a temperature lower than the boiling point of the non-aqueous solvent to be used (in the case of heating and stirring under pressure, the boiling point under pressure).
攪拌は、攪拌羽根を回転することにより行うことができ、ミル等の粉砕用ボールを用いることができる粉砕機を用いて行ってもよい。回転数等の粉砕条件は、混合物の内容と得ようとする低融点金属ナノ粒子の平均粒径に応じて、適宜選択すれば良く、攪拌羽根等の回転数を上昇させることにより、得られる低融点金属ナノ粒子の平均粒径を小さくすることができる。例えば、攪拌羽根を用いる場合、その回転数は、１００～１０００００ｒｐｍの範囲、攪拌羽根の周速は、１００～５０００ｃｍ／ｓｅｃの範囲に設定することができる。 Stirring can be performed by rotating a stirring blade, and may be performed using a pulverizer that can use pulverizing balls such as a mill. The pulverization conditions such as the number of revolutions may be appropriately selected according to the content of the mixture and the average particle diameter of the low melting point metal nanoparticles to be obtained, and can be obtained by increasing the number of revolutions of the stirring blade and the like. The average particle diameter of the melting point metal nanoparticles can be reduced. For example, when a stirring blade is used, the rotation speed can be set in the range of 100 to 100,000 rpm, and the peripheral speed of the stirring blade can be set in the range of 100 to 5000 cm / sec.
＜粉砕用ボールの分離＞
加熱・攪拌後、混合物は、攪拌をおこなった状態で、原料金属（バルク）の融点より１０℃以上低い温度まで冷却する。その後、混合物から粉砕用ボールをメッシュを通す等の公知の手段により分離して、低融点金属ナノ粒子と非水系溶媒の混合物を得る。 <Separation of balls for grinding>
After the heating and stirring, the mixture is cooled to a temperature lower by 10 ° C. or more than the melting point of the raw material metal (bulk) in the state of stirring. Thereafter, the mixture is separated from the mixture by a known means such as passing a pulverizing ball through a mesh to obtain a mixture of low melting point metal nanoparticles and a non-aqueous solvent.
＜固液分離＞
前記工程で得られた低融点金属ナノ粒子と非水系溶媒の混合物の固液分離をおこなう。固液分離は、遠心分離によりおこなうことができる。なお、用いた非水系溶媒が、低融点金属ナノ粒子の分散媒として支障ない場合には、必ずしも固液分離をおこなわなくてもよい。前記固液分離で得られた固体中に、低融点金属ナノ粒子が凝集したものが存在していることがある。この場合には、前記固体を溶媒に分散させて、超音波照射することにより、凝集を分散させることができる。前記超音波照射は、超音波洗浄装置を用い、１分間以上処理することができる。前記処理は、１分間～１時間とすることができる。また、前記固体を溶媒に分散させて、５００ｒｐｍ～１５００ｒｐｍ程度の条件で遠心分離をおこなうことにより、低融点金属ナノ粒子が凝集したものを分離することができる。 <Solid-liquid separation>
Solid-liquid separation of the mixture of the low-melting-point metal nanoparticles obtained in the above step and the non-aqueous solvent is performed. Solid-liquid separation can be performed by centrifugation. In addition, when the used non-aqueous solvent does not have a trouble as a dispersion medium of a low melting-point metal nanoparticle, it does not necessarily need to perform solid-liquid separation. In the solid obtained by the solid-liquid separation, agglomerates of low melting point metal nanoparticles may be present. In this case, aggregation can be dispersed by dispersing the solid in a solvent and irradiating with ultrasonic waves. The ultrasonic irradiation can be performed for 1 minute or longer using an ultrasonic cleaning apparatus. The treatment can be performed for 1 minute to 1 hour. In addition, by dispersing the solid in a solvent and centrifuging under a condition of about 500 rpm to 1500 rpm, agglomerated low melting point metal nanoparticles can be separated.
＜洗浄・乾燥＞
固液分離した金属ナノ粒子は、溶媒で洗浄することができる。前記溶媒としては、メタノール、エタノール等の低沸点であるアルコールの有機溶媒が好適な例としてあげられる。洗浄後、真空乾燥等の高温加熱をおこなわない方法で乾燥することにより、使用した非水系溶媒の残留が少ない低融点金属ナノ粒子粉末を得ることができる。 <Washing and drying>
The solid-liquid separated metal nanoparticles can be washed with a solvent. A suitable example of the solvent is an organic solvent of alcohol having a low boiling point such as methanol or ethanol. After washing, the powder is dried by a method that does not perform high-temperature heating such as vacuum drying, whereby low-melting-point metal nanoparticle powders with little residual non-aqueous solvent used can be obtained.
　実施例１～６として本発明にかかる低融点金属ナノ粒子の製造方法によって低融点金属ナノ粒子を製造し、製造された低融点金属ナノ粒子についての測定・観察を行った。また、比較例１、２として、本発明の要件である、混合物をその混合物の材料である低融点金属の融点－５℃～前記低融点金属の融点＋２０℃でもって加熱・攪拌を行うという条件を、本発明要件の範囲外に変更した状態で低融点金属ナノ粒子の製造を試みた。 As Examples 1 to 6, low melting point metal nanoparticles were produced by the method for producing low melting point metal nanoparticles according to the present invention, and the produced low melting point metal nanoparticles were measured and observed. Further, as Comparative Examples 1 and 2, the requirement of the present invention is that the mixture is heated and stirred at the melting point of the low melting point metal, which is the material of the mixture, from −5 ° C. to the melting point of the low melting point metal + 20 ° C. Attempts were made to produce low-melting-point metal nanoparticles in a state that was changed outside the scope of the present invention.
　［実施例１］
６Ｎのインジウムを１０ｇ秤量し、このインジウムを５００ｍＬのセパラブルフラスコに投入した。前記インジウムの融点を示差走査熱量計（ＤＳＣ）（株式会社リガク製、Ｔｈｅｒｍｏｐｌｕｓ　ＤＳＣ８２３０）で測定した結果、融点は、１５７℃であった。次に０．３ｍｍΦのジルコニアボール１ｋｇを前記セパブルフラスコに投入し、更に、テトラエチレングリコール３００ｍＬを投入して、混合物を得た。この後、セパラブルフラスコの上蓋をして密封し、窒素ガスを１００ｍＬ／ｍｉｎで流し、１０分間ガス置換をした。次に、セパブルフラスコ内に設置してあった回転径が６ｃｍのステンレス製の攪拌羽根を７００ｒｐｍ回転させることにより攪拌をおこなった状態で、混合物を１６１℃（加熱温度）まで加熱した。なお、混合物の温度は、セパブルフラスコ内に設置された熱電対により測定した。混合物を前記加熱温度で５時間保持した後、前記攪拌状態を維持したまま、前記混合物を５℃／ｍｉｎの冷却速度で冷却した。混合物が４０℃以下になった段階で攪拌羽根の回転を止めた。次にこの混合物を２５０メッシュのナイロン生地の網を通過させて、０．３ｍｍΦのジルコニアボールを混合物から分離した。ろ過された側には低融点金属ナノ粒子が分散した溶媒（テトラエチレングリコール）が回収された。 [Example 1]
10 g of 6N indium was weighed, and this indium was put into a 500 mL separable flask. As a result of measuring the melting point of indium with a differential scanning calorimeter (DSC) (Thermoplus DSC8230, manufactured by Rigaku Corporation), the melting point was 157 ° C. Next, 1 kg of 0.3 mmφ zirconia balls was charged into the separable flask, and 300 mL of tetraethylene glycol was further charged to obtain a mixture. Thereafter, the upper lid of the separable flask was sealed and sealed, and nitrogen gas was allowed to flow at 100 mL / min to perform gas replacement for 10 minutes. Next, the mixture was heated to 161 ° C. (heating temperature) in a state where stirring was performed by rotating a stirring blade made of stainless steel having a rotational diameter of 6 cm, which had been installed in the separable flask, by rotating 700 rpm. The temperature of the mixture was measured with a thermocouple installed in a separable flask. After maintaining the mixture at the heating temperature for 5 hours, the mixture was cooled at a cooling rate of 5 ° C./min while maintaining the stirring state. When the mixture became 40 ° C. or lower, the rotation of the stirring blade was stopped. The mixture was then passed through a mesh of 250 mesh nylon fabric to separate 0.3 mmΦ zirconia balls from the mixture. On the filtered side, a solvent (tetraethylene glycol) in which the low melting point metal nanoparticles were dispersed was recovered.
　テトラエチレングリコールを洗浄除去するために、前記低融点金属ナノ粒子が分散した溶媒を３５００ｒｐｍ、３時間の処理条件で遠心分離して固液分離し、上澄みの液体を除去して、固形分を回収した。この後、下記の要領で、洗浄を行った。回収した固形分を５００ｍLのエタノールと1時間攪拌混合し、再分散した後、３５００ｒｐｍ、３時間の処理条件で遠心分離して固液分離し、上澄みの液体を除去する操作を３回繰り返し、エタノールを少量含む固形分を得た。 In order to wash away tetraethylene glycol, the solvent in which the low-melting-point metal nanoparticles are dispersed is centrifuged at 3500 rpm for 3 hours to perform solid-liquid separation, and the supernatant liquid is removed to recover the solid content. did. Thereafter, cleaning was performed in the following manner. The collected solid content is stirred and mixed with 500 mL of ethanol for 1 hour, redispersed, centrifuged at 3500 rpm for 3 hours and solid-liquid separation, and the operation of removing the supernatant liquid is repeated 3 times. A solid content containing a small amount of was obtained.
　前記エタノールを少量含む固形分を乾燥後、Ｘ線回折装置（株式会社リガク製、ＲＩＮＴ－１２００）を用いて、Ｘ線回折測定をおこなった。測定結果を図１に示す。検出されたピーク位置は、Ｉｎと一致しており、Ｉｎ２Ｏ３と一致していなかった。このことから、得られた粒子粉末は、Ｉｎ粒子粉末であることが確認された。 After the solid content containing a small amount of ethanol was dried, X-ray diffraction measurement was performed using an X-ray diffractometer (RINT-1200, manufactured by Rigaku Corporation). The measurement results are shown in FIG. The detected peak position was coincident with In, and did not coincide with In 2 O 3 . From this, it was confirmed that the obtained particle powder was In particle powder.
　前記エタノールを少量含む固形分０．１ｇを分取して、エタノール５０ｍＬに添加した後、超音波洗浄装置を用いて１０分間処理し、分散させた。この分散液を乾燥し、ＴＥＭ（透過型電子顕微鏡、４０万倍）で観察した結果を図２に示す。８ｎｍ前後のナノ粒子が生成していることがわかった。 A solid content of 0.1 g containing a small amount of ethanol was collected and added to 50 mL of ethanol, and then treated and dispersed for 10 minutes using an ultrasonic cleaning device. FIG. 2 shows the result of drying this dispersion and observing it with a TEM (transmission electron microscope, 400,000 magnifications). It was found that nanoparticles of around 8 nm were generated.
　前記で得られたＴＥＭ像から低融点金属ナノ粒子の平均粒径を求めた。本発明では、低融点金属ナノ粒子の平均粒子径としてＴＥＭ（透過型電子顕微鏡）により求まる平均粒子径ＤＴＥＭを採用する。本発明では、ＴＥＭにより倍率４００，０００倍で観察される粒子のうち、重なっていない独立した５０個の粒子径（長軸径）を計測して、平均粒子径を算出する。平均粒径の結果を表１に示す。
Figure JPOXMLDOC01-appb-T000001
 The average particle diameter of the low melting point metal nanoparticles was determined from the TEM image obtained above. In the present invention, employing the average particle diameter D TEM of an average particle diameter of the low melting point metal nanoparticles obtained by TEM (transmission electron microscope). In the present invention, among the particles observed by a TEM at a magnification of 400,000, 50 independent particle diameters (major axis diameters) that do not overlap are measured to calculate an average particle diameter. The average particle size results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
　［実施例２］  
加熱温度を１６１℃から１５６℃、１６６℃に変更した以外は、実施例１と同様に低融点金属ナノ粒子の生成と測定を試みた。得られた低融点金属ナノ粒子の平均粒径を表１に示す。１５６℃、１６６℃の場合とも、Ｘ線回折の結果は実施例１と同様であった。 [Example 2]
The production and measurement of low melting point metal nanoparticles were attempted in the same manner as in Example 1 except that the heating temperature was changed from 161 ° C to 156 ° C and 166 ° C. Table 1 shows the average particle size of the obtained low melting point metal nanoparticles. The results of X-ray diffraction were the same as in Example 1 at 156 ° C. and 166 ° C.
　［比較例１］  
加熱温度を１６１℃から１５０℃、１８０℃に変更した以外は、実施例１と同様に低融点金属ナノ粒子の生成を試みた。大粒径のＩｎ粒子が生成して、混合物を２５０メッシュのナイロン生地の網を通過させる際に、ほとんど通過することができず、低融点金属ナノ粒子は得られなかった。 [Comparative Example 1]
The production of low melting point metal nanoparticles was attempted in the same manner as in Example 1 except that the heating temperature was changed from 161 ° C. to 150 ° C. and 180 ° C. When large particles of In particles were formed and the mixture was passed through a mesh of 250 mesh nylon fabric, it could hardly pass through and low melting point metal nanoparticles were not obtained.
　［実施例３］  
使用する原料金属を６Ｎのインジウムから６Ｎのガリウムに変更し、加熱温度を１６１℃から３５℃に変更した以外は、実施例１と同様に低融点金属ナノ粒子の生成と測定を試みた。得られた低融点金属ナノ粒子の平均粒径を表２に示す。Ｘ線回折の結果、Ｇａのピーク位置と一致するピークが確認された。 [Example 3]
The production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 1 except that the raw material metal used was changed from 6N indium to 6N gallium and the heating temperature was changed from 161 ° C to 35 ° C. Table 2 shows the average particle diameter of the obtained low melting point metal nanoparticles. As a result of X-ray diffraction, a peak corresponding to the Ga peak position was confirmed.
　［実施例４］  
加熱温度を３５℃から２９℃、４０℃に変更した以外は、実施例３と同様に低融点金属ナノ粒子の生成と測定を試みた。得られた低融点金属ナノ粒子の平均粒径を表２に示す。
Figure JPOXMLDOC01-appb-T000002
 [Example 4]
Except for changing the heating temperature from 35 ° C. to 29 ° C. and 40 ° C., production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 3. Table 2 shows the average particle diameter of the obtained low melting point metal nanoparticles.
Figure JPOXMLDOC01-appb-T000002
　［比較例２］  
加熱温度を３５℃から２４℃、５０℃に変更した以外は、実施例３と同様に低融点金属ナノ粒子の生成を試みた。大粒径のＧａ粒子が生成して、混合物を２５０メッシュのナイロン生地の網を通過させる際に、ほとんど通過することができず、低融点金属ナノ粒子は得られなかった。 [Comparative Example 2]
The production of low melting point metal nanoparticles was attempted in the same manner as in Example 3 except that the heating temperature was changed from 35 ° C. to 24 ° C. and 50 ° C. When Ga particles having large particle sizes were formed and the mixture was passed through a mesh of 250 mesh nylon fabric, it was hardly possible to pass through the mixture, and low melting point metal nanoparticles were not obtained.
　［実施例５］  
使用する原料金属を６Ｎのインジウムからビスマスに変更し、加熱温度を１６１℃から２７６℃に変更した以外は、実施例１と同様に低融点金属ナノ粒子の生成と測定を試みた。得られた低融点金属ナノ粒子の平均粒径を表３に示す。Ｘ線回折の結果、Ｂｉのピーク位置と一致するピークが確認された。 [Example 5]
The production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 1 except that the raw material metal used was changed from 6N indium to bismuth and the heating temperature was changed from 161 ° C to 276 ° C. Table 3 shows the average particle size of the obtained low-melting-point metal nanoparticles. As a result of X-ray diffraction, a peak corresponding to the Bi peak position was confirmed.
　［実施例６］  
加熱温度を２７６℃から２７１℃、２８１℃に変更した以外は、実施例５と同様に低融点金属ナノ粒子の生成と測定を試みた。得られた低融点金属ナノ粒子の平均粒径を表３に示す。
Figure JPOXMLDOC01-appb-T000003
 [Example 6]
The production and measurement of low-melting-point metal nanoparticles were attempted in the same manner as in Example 5 except that the heating temperature was changed from 276 ° C. to 271 ° C. and 281 ° C. Table 3 shows the average particle size of the obtained low-melting-point metal nanoparticles.
Figure JPOXMLDOC01-appb-T000003
　本発明は、粒径が微細である低融点金属ナノ粒子の製造方法に適用できる。 The present invention can be applied to a method for producing low melting point metal nanoparticles having a fine particle size.

Claims (8)

  1. 容器中に、固体または液体の低融点金属と、非水系溶媒と、直径０．０１５ｍｍ～５ｍｍの粉砕用ボールとを入れ、混合物を得る工程と、
    前記混合物を前記低融点金属の融点－５℃～前記低融点金属の融点＋２０℃に加熱し、攪拌する工程と、
    攪拌後の前記混合物から粉砕用ボールを分離して、低融点金属ナノ粒子と非水系溶媒の混合物を得る工程と、
    前記低融点金属ナノ粒子と非水系溶媒の混合物を固液分離して、低融点金属ナノ粒子を得る工程を有する、低融点金属ナノ粒子の製造方法。     Placing a solid or liquid low melting point metal, a non-aqueous solvent, and grinding balls having a diameter of 0.015 mm to 5 mm in a container to obtain a mixture;
    Heating the mixture from the melting point of the low melting point metal to -5 ° C. to the melting point of the low melting point metal + 20 ° C. and stirring;
    Separating the balls for grinding from the mixture after stirring to obtain a mixture of low melting point metal nanoparticles and a non-aqueous solvent;
    A method for producing a low-melting-point metal nanoparticle comprising a step of solid-liquid separation of a mixture of the low-melting-point metal nanoparticle and a non-aqueous solvent to obtain a low-melting-point metal nanoparticle.
  2. 前記低融点金属が、Ｉｎ、Ｇａ、Ｂｉ、Ｓｎの群から選択される１種以上である、請求項１に記載の低融点金属ナノ粒子の製造方法。 The method for producing low-melting-point metal nanoparticles according to claim 1, wherein the low-melting-point metal is at least one selected from the group of In, Ga, Bi, and Sn.
  3. 前記非水系溶媒はアルデヒド基またはヒドロキシ基を有する有機溶媒である、請求項１に記載の低融点金属ナノ粒子の製造方法。 The method for producing low-melting-point metal nanoparticles according to claim 1, wherein the non-aqueous solvent is an organic solvent having an aldehyde group or a hydroxy group.
  4. 前記非水系溶媒は一級アミノ基、または二級アミノ基、または三級アミノ基の内の少なくとも一種以上を含む有機溶媒である、請求項１に記載の低融点金属ナノ粒子の製造方法。 The method for producing low-melting-point metal nanoparticles according to claim 1, wherein the non-aqueous solvent is an organic solvent containing at least one of a primary amino group, a secondary amino group, or a tertiary amino group.
  5. 前記攪拌する工程は、攪拌羽根を周速２００ｃｍ／秒～２０００００ｃｍ／秒で回転させることにより行われる、請求項１に記載の低融点金属ナノ粒子の製造方法。 The method for producing low-melting-point metal nanoparticles according to claim 1, wherein the stirring step is performed by rotating a stirring blade at a peripheral speed of 200 cm / sec to 200000 cm / sec.
  6. 前記固液分離を遠心分離により行う、請求項１に記載の低融点金属ナノ粒子の製造方法。 The method for producing low-melting-point metal nanoparticles according to claim 1, wherein the solid-liquid separation is performed by centrifugation.
  7. 前記低融点金属ナノ粒子と非水系溶媒の混合物を固液分離した後、低融点金属ナノ粒子を沸点１５０℃以下の有機溶媒で洗浄する、請求項１に記載の低融点金属ナノ粒子の製造方法。 The method for producing low-melting-point metal nanoparticles according to claim 1, wherein after the mixture of the low-melting-point metal nanoparticles and the non-aqueous solvent is solid-liquid separated, the low-melting-point metal nanoparticles are washed with an organic solvent having a boiling point of 150 ° C or lower. .
  8. 前記低融点金属の体積が、前記非水系溶媒の体積の０．１体積％～２０体積％である、請求項１に記載の低融点金属ナノ粒子の製造方法。 The method for producing low-melting-point metal nanoparticles according to claim 1, wherein the volume of the low-melting-point metal is 0.1 vol% to 20 vol% of the volume of the non-aqueous solvent.
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Publication number Priority date Publication date Assignee Title
CN103212716A (en) * 2013-04-23 2013-07-24 吴鋆 Method of preparing metal zinc powder
CN111774576A (en) * 2020-07-09 2020-10-16 东莞职业技术学院 Preparation method of nano metal particles
CN114592151A (en) * 2022-03-08 2022-06-07 太原理工大学 Alloy used as electronic printing ink and preparation method thereof

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JPS64204A (en) * 1987-06-22 1989-01-05 Fukuda Metal Foil & Powder Co Ltd Production of low melting point metal powder
JPH0533017A (en) * 1991-07-15 1993-02-09 Minnesota Mining & Mfg Co <3M> Preparation of low melting point metal fine particle and composition containing it
JPH06346118A (en) * 1993-06-04 1994-12-20 Japan Energy Corp Method for pulverizing indium or indium alloy
WO2009011981A2 (en) * 2007-05-31 2009-01-22 The Administrators Of The Tulane Educational Fund Method of forming stable functionalized nanoparticles

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JPS64204A (en) * 1987-06-22 1989-01-05 Fukuda Metal Foil & Powder Co Ltd Production of low melting point metal powder
JPH0533017A (en) * 1991-07-15 1993-02-09 Minnesota Mining & Mfg Co <3M> Preparation of low melting point metal fine particle and composition containing it
JPH06346118A (en) * 1993-06-04 1994-12-20 Japan Energy Corp Method for pulverizing indium or indium alloy
WO2009011981A2 (en) * 2007-05-31 2009-01-22 The Administrators Of The Tulane Educational Fund Method of forming stable functionalized nanoparticles

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103212716A (en) * 2013-04-23 2013-07-24 吴鋆 Method of preparing metal zinc powder
CN111774576A (en) * 2020-07-09 2020-10-16 东莞职业技术学院 Preparation method of nano metal particles
CN114592151A (en) * 2022-03-08 2022-06-07 太原理工大学 Alloy used as electronic printing ink and preparation method thereof

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