WO2006070571A1

WO2006070571A1 - Atomized gold powder, conductive gold paste using same and gold clay for decoration

Info

Publication number: WO2006070571A1
Application number: PCT/JP2005/022461
Authority: WO
Inventors: Yukio Iijima; Masakatsu Sato; Koji Yamamoto; Yosuke Igarashi
Original assignee: Nippon Atomized Metal Powders Corporation
Priority date: 2004-12-27
Filing date: 2005-12-07
Publication date: 2006-07-06
Also published as: JP2006183076A

Abstract

Disclosed is a gold powder produced by an atomization process. The crystal grain size of the gold powder is 100-800 nm, and the average particle diameter of the powder is 1-10 μm. The temperature at which shrinking of the gold powder begins during the sintering process is not less than 350˚C.

Description

Atomized gold powder and conductive gold paste and decorative gold using it

Technical field

The present invention relates to a gold powder obtained by atomization and a conductive gold paste and a decorative gold clay using the same, and in particular, a conductor paste for forming an electronic circuit and a ring 'necklace' Such as jewelry · It relates to atomized gold powder used for gold clay to make decorative products.

Background art

Conductive paste is used as a material for forming conductive films (wirings, electrodes, etc.) of a predetermined pattern on ceramic wiring substrates used in integrated circuits, multichip modules, etc., and other electronic components etc. Be For example, when a conductive film is formed on a substrate, the occurrence of structural defects such as delamination and cracks of the conductive film must be prevented. In addition, conductive metal powder is required which suppresses expansion and contraction phenomena in the firing process as much as possible, and the sintering start temperature is high!

[0003] For example, Japanese Patent Application Laid-Open No. 2002-20809 discloses a spherical, uniform, high-purity, high-density, high-dispersion spherical particle size suitable for a thick film paste, particularly a conductor paste for producing a ceramic laminated electronic component. Disclosed is a method of producing a fine, highly crystalline metal powder! In this publication, as a required characteristic for a conductive metal powder to be used for a conductor paste for forming an electronic circuit, it is necessary to use a fine powder having few impurities and having an average particle diameter of about 0.1 l m-l O ^ m. Certainly, the particle shape and the particle diameter are uniform, it is monodispersed particles without aggregation, the dispersibility in the paste is good, and the crystallinity is good so as not to cause non-uniform sintering. Is pointed out (paragraph 0002). Here, good crystallinity means that it is in the form of spheres, low in activity, high in crystallinity, or single crystals in which expansion and contraction due to oxidation reduction does not occur during sintering and the sintering start temperature is high. Meaning, ru (paragraph 0002)

[0004] On the other hand, recently, with regard to precious metal jewelry such as rings and necklaces and art and crafts etc. Precious metal clays are marketed to allow individuals to easily and easily make originals. Such clay-like materials are shaped or sculpted into a desired shape, and then heated and sintered to produce the above-mentioned jewelry or craft. At that time, the size and shape can be made as desired by minimizing the expansion / contraction amount in the sintering process.

[0005] Japanese Patent Application Publication No. 2003-193101 discloses a paste for forming a gold film or a gold alloy film on the surface of a silver clay sintered body and a method of forming the same. According to this publication, if the gold or gold alloy powder contained in the fluid paste is made into a fine powder having an average particle diameter of 3 μm, which is finer than the silver powder contained in silver clay, the gold or gold alloy is simply applied to the flame. It is described that a film can be formed, and it is further described that a spherical gold fine powder with an average particle diameter of less than 3 / zm can be obtained by a chemical reduction method (paragraph 0005).

[0006] As a method of producing a gold powder, there are a spray pyrolysis method, a chemical reduction method, an atomization method and the like.

The properties of the conductive paste and clay material largely depend on the properties of the gold powder contained in them.

Also, the powder properties of the gold powder vary greatly depending on the method of production.

[0007] Japanese Patent Application Laid-Open No. 10-102108 discloses a method of producing a noble metal powder for thick film paste by a spray pyrolysis method. In the spray pyrolysis method, a solution containing a metal salt constituting a powder is sprayed into droplets, and the droplets are heated at a temperature higher than the decomposition temperature of the metal salt (above the melting point of the metal) to form the metal salt. By thermal decomposition to precipitate metal powder.

The chemical reduction method also described in JP-A-2003-193101 is a method of producing a powder by reducing a solution (a raw material salt solution) containing a salt of a metal constituting the powder.

The atomizing method is a method of heating a metal constituting a powder to a molten state, atomizing the molten metal to form droplets, and solidifying in the process of cooling to produce powder particles. JP-A-8-134501 discloses a sintered material for precious metal products obtained by pulverizing a precious metal material by a water atomizing method. In this publication, an organic binder solution and lead oxide are added to a noble metal powder obtained by a water atomizing method, and either one or both of silicon oxide and alumina are further added to clay. It is described that a precious metal jewelry product is manufactured by producing a metal-like material and forming and sintering it. Here, as the oxide to be added to the gold powder, in addition to silicon oxide or alumina, lead oxide is not essential. This is to obtain a sintered body having high color strength and high strength (paragraph 0011).

[0010] As seen in the above prior art, gold (Au) is one of metal powders used in conductive pastes and clay materials. As described above, for the conductive film formed on the ceramic wiring substrate or the like, it is necessary to suppress the expansion and contraction phenomena of the conductive film during firing as much as possible. In addition, in order to finish precious metal clay containing gold powder into jewelry of a desired size and shape, it is necessary to minimize the amount of expansion and contraction in the sintering process as much as possible.

The inventors of the present invention have found that the crystal grain size of gold powder is closely related to the expansion and contraction phenomena in the process of sintering paste and clay. In Japanese Patent Application Laid-Open Nos. 2002-20809, 2003-193101, 10-102108 and 8-134501 cited above, the description of the grain size of the gold powder is given. Absent.

According to the spray pyrolysis method, it is possible to produce a powder having a fine texture, such as 50 nm (nm 2), in the crystal grain size that constitutes the base of the gold powder. When gold powder having such a fine grain size is used as a paste or clay material, the phenomenon of diffusion and sintering between gold powder particles significantly progresses at a low temperature during the heating process, resulting in abnormal shrinkage. Show the behavior. This abnormal shrinkage behavior causes problems such as cracks in the paste thin film and peeling from the substrate, and causes appearance defects such as deformation of the jewelry and dimensional errors. In order to prevent such anomalous shrinkage behavior, it is necessary to make the grain size of the gold powder larger. However, in spray pyrolysis, a more appropriate grain size range, eg, ΙΟΟπ! It is difficult to produce gold powder with a grain size of ~ 1 μm.

[0013] Also in the method of producing a gold powder by the chemical reduction method, it is difficult to produce a gold powder having a crystal grain size of about 100 nm to 1 μm as in the spray pyrolysis method.

Japanese Patent Application Laid-Open No. 8-134501 describes the use of a gold powder obtained by a water atomization method as a sintered material for precious metal products. Then, in order to improve the strength of the sintered body, an organic binder solution and lead oxide are added to noble metal powder such as gold, and either one of silicon oxide and alumina, or It is characterized by adding both to make it like clay. In the case of this method, fine acid oxide particles tend to aggregate, so the strength of the sintered body is reduced rather than if sufficient stirring treatment is not performed. In addition, environmental aspect is also lead component It can be pointed out that the essential use of lead acid with acid is undesirable. Therefore, in order to improve the strength of the sintered body, another method that does not rely on an approach such as addition of acid oxide particles as disclosed in JP-A-8-134501 is required.

Disclosure of the invention

[0015] An object of the present invention is to provide a gold powder which can suppress the amount of expansion and contraction in the sintering process.

[0016] Another object of the present invention is to provide a conductive gold paste using the above-mentioned gold powder.

[0017] Still another object of the present invention is to provide a decorative gold clay using the above-mentioned gold powder.

The present invention is a gold powder obtained by an atomizing method, and has a crystal grain size of 100 to 800 nanometers (nm). In the present specification, “crystal grain size” means an average crystal grain size.

The crystal grain size of the more preferable gold powder is 200 to 500 nm.

The average particle size of the preferred gold powder is 1 to: LO / z m, more preferably 3 to 5 μm

[0021] Preferably, the gold powder has the property of not exhibiting expansion behavior during the sintering process. In the present specification, the term "sintering" and the term "sintering" are not strictly used, but the terms "sintering" and "sintering" are mainly used as a concept including both.

Preferably, the shrinkage behavior start temperature in the sintering process of the gold powder is 350 ° C. or more.

Preferably, the melting point of the gold powder is 600 ° C. or more, more preferably 800 ° C. or more.

The gold powder is preferably a water-atomized gold powder obtained by solidifying a fine droplet from molten gold by spraying water.

The conductive gold paste according to the present invention is characterized by using the above-described atomized gold powder.

The decorative gold clay according to the present invention is characterized by using the above-described atomized gold powder. Preferably, the decorative gold clay comprises, in addition to the atomized gold powder, an organic binder solution and oxide particles. In this case, the oxide particles are aluminum oxide, silicon oxide, It is one or more oxides selected from the group consisting of tin oxide, calcium oxide, magnesium oxide, copper oxide and silver oxide.

[0027] The configuration of the present invention is as described above, but the function, effect, meaning and the like of each component will be described in the section "Best Mode for Carrying Out the Invention" below. Brief description of the drawings

FIG. 1 is a view showing the results of measurement of expansion and contraction behavior of a gold powder produced by a water atomization method in the heating process using a dermatometer.

FIG. 2 is a diagram showing the results of measurement of expansion / contraction behavior in the heating process of a gold powder produced by a chemical reduction method using a delatometer.

[FIG. 3] A diagram showing the results of measurement of expansion and contraction behavior of a gold powder produced by a spray pyrolysis method in the heating process using a dermatometer.

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Grain size of atomized gold powder

The inventors of the present invention have found that the grain size of the gold powder greatly affects the expansion / shrinkage behavior in the sintering process and the strength of the sintered body when it is used for the conductive paste or clay-like material. I found it. The grain size of the gold powder needs to be in the range of 100 to 800 nanometers (nm), and a more preferable range is 200 to 500 nm.

[0030] The inventor of the present invention has found that, if the crystal grain size of the gold powder is less than lOOnm, the diffusion between the gold powder particles is likely to progress through a large number of trial manufactures and experiments. It has been found that an abnormal contraction phenomenon occurs in the burning process. Therefore, when a gold powder having a crystal grain size of less than 10 O nm is used as the conductive paste, shrinkage causes problems such as cracks in the paste film and peeling between the substrate and the paste. In addition, when gold powder with such a fine crystal grain size is used as a sintered clay material for jewelry, the dimensional change and deformation of the jewelry after sintering are remarkable as compared with the clay state before sintering. Therefore, it can not be used as jewelry and crafts.

Furthermore, in the case of a gold powder having a crystal grain size of less than 100 nm, the melting point falls below 700 to 800 ° C., and as a result, the clay molded body melts in the sintering process, resulting in a jewelery product. Production becomes difficult. FIG. 1 to FIG. 3 show the results of measurement of expansion / contraction behavior in the heating process by using a delatometer with respect to gold powders having different crystal grain sizes. Fig. 1 shows the results when using gold powder produced by water atomization, Fig. 2 shows the results when using gold powder produced by chemical reduction, and Fig. 3 shows spray pyrolysis. It is the result at the time of using the gold powder produced by the method. The crystal grain size and the powder mean grain size of each powder were as follows.

In the case of the gold powder produced by the water atomization method of FIG. 1, the crystal grain size was 255 nm and the powder average grain size was 4.6 m. In the case of the gold powder produced by the chemical reduction method of FIG. 2, the crystal grain size was 54 nm and the powder average grain size was 0. In the case of the gold powder prepared by the spray heat decomposition method of Fig. 3, the crystal grain size is 55 nm and the powder average grain size is 5. 7 μm7.

The water atomized gold powder with a grain size of 255 nm shown in FIG. 1 starts the shrinkage phenomenon at 407 ° C., whereas the gold powder by a chemical reduction method with a grain size of 5 lnm shown in FIG. The contraction phenomenon starts in a low temperature region such as 221 ° C. Further, in the case of the gold powder according to the spray pyrolysis method with a crystal grain diameter of 55 mm in FIG. In the case where a gold powder causing such an expansion phenomenon is used as a conductive paste, there is a problem that the expansion phenomenon causes separation between the substrate and the paste.

On the other hand, when comparing the melting point of each powder, while the gold powder by the water atomizing method in FIG. 1 has a melting point of about 1000 ° C., fine grains of less than lOOnm shown in FIG. 2 and FIG. It can be seen that gold powder by chemical reduction or spray pyrolysis with diameter has a low V, melting point such as 680-700 ° C.

[0036] The conductive paste and the clay-like material sinter at around 600 to 800 ° C. In Figs. 1 to 3, for example, when the amount of shrinkage of each gold powder at 600 ° C is compared, it is 0.4% in water atomized gold powder, but the gold by the chemical reduction method or the spray pyrolysis method is 0.4%. The powder has a high value of 2.5% and 2. 7%, respectively! As a result, in the case of a gold powder having a fine crystal grain size of less than 100 mm, the sintering progresses remarkably, and as a result, the amount of shrinkage in the sintering process increases, causing cracks in the paste film and the like. It causes appearance defects such as peeling from the substrate, cracks and deformations in jewelry, and dimensional errors.

On the other hand, the strength of the paste film or sintered clay after sintering is determined by the grain size of the gold powder. Should be small. When the crystal grain size exceeds 800 nm, sufficient strength and hardness can not be obtained in the sintered paste film or clay sintered body. In addition, in the case of a gold powder having a large grain size of more than 800 nm, it is difficult to obtain a good paste having high conductivity because the sinterability is lowered.

As described above, in order to reduce the amount of shrinkage in the sintering process as much as possible and to improve the strength after sintering, a gold powder is produced by an atomizing method and the crystal grain size thereof. Needs to be in the range of 100 nm to 800 nm. As a more preferable crystal grain size, it is 200-50 Onm.

(2) Average Particle Size of Atomized Gold Powder

The particle size of the gold powder is one of the factors governing the sinterability between the powders. The average particle size of the atomized gold powder according to the invention is preferably in the range of 1 to: LO / z m. Furthermore, in order to suppress the abnormal shrinkage phenomenon in the sintering process and to ensure good sinterability, it is more desirable to make the average particle size of the gold powder in the range of 3 to 5 μm.

When the average particle size of the gold powder is less than 1 μm, the surface diffusion among the powders is promoted, so the onset temperature of the shrinkage phenomenon accompanying sintering becomes below 350 ° C., and the paste or clay form When used in materials, the above-mentioned defects occur. In addition, powder agglomeration and reduced tap density cause problems which make it unsuitable for conductive paste.

On the other hand, when the average particle diameter of the gold powder exceeds 10 μm, it becomes difficult to form a fine electronic circuit pattern, which is a required characteristic as a paste.

The gold powder produced by the chemical reduction method is as fine as 0.5 to 1 μm or less in the average particle diameter of the powder, and therefore, as described above, the powder surface diffusion is facilitated to proceed as described above. Sintering between powders starts near C. Therefore, in the sintering at 600 to 800 ° C., an abnormal shrinkage phenomenon is accompanied and problems such as cracking in the paste film and peeling from the substrate occur.

(3) Behavior and melting point in the sintering process of atomized gold powder

As described above, when gold powder which causes expansion phenomenon in the sintering process is used as the conductive paste, the expansion phenomenon causes separation between the substrate and the paste. Therefore, preferably, the atomized gold powder has the property of not exhibiting expansion behavior in the sintering process in an inert gas atmosphere or in the air. Anomalous shrinkage behavior in the low temperature range of the sintering process can be suppressed by setting the crystal grain size and the powder mean grain size of the gold powder in appropriate ranges. Although some shrinkage phenomena accompanying sintering can not be avoided, in the case of the gold powder of the present invention, preferably, the shrinkage behavior start temperature in the sintering process in an inert gas atmosphere or in the atmosphere is 350 ° C. or higher. is there.

[0045] The gold powder produced by the atomization method exhibits a higher melting point in the sintering process in an inert gas atmosphere or in the air, as compared to the gold powder produced by the spray pyrolysis method or the chemical reduction method. The preferred melting point of the gold powder is 600 ° C. or more, more preferably 800 ° C. or more.

In the atomizing method, there is a force with a gas atomizing method and a water atomizing method. In order to obtain gold powder having physical characteristics such as crystal grain diameter and powder average particle diameter in the appropriate range as described above, water atomizing method is used. Is preferred. Specifically, the gold powder is preferably a water atomized gold powder obtained by spraying water onto fine droplets of molten gold and solidifying it.

(4) Conductive gold paste using atomized gold powder

The conductive gold base using the atomized gold powder having the preferred physical properties as described above can suppress the expansion and contraction phenomena of the conductive film in the sintering process, so that the conductive film has high reliability. You can get

(5) Gold clay for decoration using atomized gold powder

If an organic binder solution and oxide particles are added to the atomized gold powder having preferable physical properties as described above to prepare gold clay, high strength and small amount of dimensional change, high dimensional accuracy can be obtained. Can produce gold jewelry and gold crafts etc. The oxide particles to be added are aluminum oxide, silicon oxide, tin oxide, calcium oxide, magnesium oxide, copper oxide, and a group of copper oxide and silver oxide, and one or more selected oxides. is there.

As described above, in the method for producing gold clay disclosed in JP-A-8-134501, the addition of lead oxide is essential for the purpose of improving the strength of the sintered body. From the environmental point of view, it is not preferable to use lead acid containing lead. On the other hand, even in the case of using oxide particles other than lead oxide in the water atomized gold powder which is a preferred embodiment of the present invention, the crystal grain diameter is in an appropriate range of 100 to 800 nm. Satisfyingly, it has high strength, and it is possible to have dimensional change before and after sintering, in particular, with abnormal shrinkage. You can get good gold jewelry and gold crafts.

Example 1

[0050] In the ring of 'deer) ^ ratio: ratio of

Gold powder (average grain size: 280 nm) prepared by the water atomization method with an average particle size of 3 μm is prepared as 92% by weight ratio and 8% water-soluble cellulose clay, and they are mixed to obtain atomized gold Powdered gold clay (referred to as clay A) was prepared. On the other hand, a gold powder (average grain size: 60 nm) prepared by a chemical reduction method having an average grain size of 1 is similarly mixed with a water-soluble cellulose clay at the same mixing ratio and contains a gold powder made from chemical reduction. Gold clay (designated as clay B) was made. Five ring-shaped test pieces each having a thickness of 3 mm and a diameter of 13 mm were prepared for each of clay A and clay B force, and each was put in a drier with an internal atmosphere temperature of 150 ° C. for 10 minutes for drying. After that, it was heated and held in a baking furnace at 800 ° C. for 10 minutes for baking, and the shrinkage rate was measured. At that time, it was evaluated whether the force at which 5% or more expansion and contraction occurred with respect to the diameter of the test piece before firing was generated. As a result, all of the test pieces of clay A had a shrinkage of less than 5%. On the other hand, in each of the specimens of clay B, a large shrinkage phenomenon of about 7 to 12% was observed.

Example 2

[0051] A gold powder (powder A) having an average particle diameter of 3. 1 ^ m and an average crystal particle diameter of 315 nm produced by a water atomizing method, and the gold powder heat treated to give an average crystal particle diameter of 2. Powder (powder B) and gold powder (powder C) having an average particle diameter of 0.9 / ζπι and an average crystal particle diameter of 45 nm prepared by the ichological reduction method are prepared, and ceramic wiring boards are manufactured using these. A conductive gold paste was prepared. A wiring pattern was prepared on a substrate using each paste and fired. In powder A, a good wiring without cracks and without peeling from the substrate was obtained. On the other hand, when powder B was used, many cracks were generated in the paste thin film because sintering between gold powders did not proceed sufficiently. In powder C, peeling occurred with the substrate where the amount of shrinkage of the paste after firing was large.

Example 3

[0052] A gold powder having different average particle sizes and average crystal grain sizes was produced by a water atomization method. In addition, heat treatment was performed on a part of the gold powder in a vacuum atmosphere in order to adjust the average grain size. The average grain size and the average grain size of each powder are shown in Table 1. Each gold The expansion and contraction behavior of the powder during the heating process was evaluated using a dermatometer. The contraction initiation temperature is shown in Table 1 below. In addition, a mixture of gold powder and water-soluble cellulose clay is blended so that the content of gold powder is 92% by weight of the whole, and a ring-shaped test piece is produced from the obtained gold clay, Each was subjected to a drying step at 150 ° C. and baked at 800 ° C. for 20 minutes. The radial crushing strength of the obtained ring test piece was measured. The results are shown in Table 1 below.

[Table 1]

In Table 1, sample Nos. 4 to 9 are inventive examples, and sample Nos. 1 to 3 and 10 are comparative examples.

In the atomized gold powder of the example of the present invention, by having an appropriate average particle diameter and an average crystal grain diameter, a favorable ring-shaped sintered body free of cracks and the like is obtained after firing at 800 ° C. Moreover, the strength as a ring is also sufficient. On the other hand, the following problems were confirmed in the comparative example.

That is, in samples No. 1 and 2, since the average grain size and the average crystal grain size are small, large anomalous shrinkage occurs in the firing process, and as a result, in the sample No. 1, the ring shape can not be maintained. Was impossible. Further, in sample No. 2, the ring strength decreased due to the deformation. In Samples No. 3 and 4, since the average grain size was larger than the appropriate value, sintering did not proceed sufficiently in the firing at 800 ° C., and as a result, the strength of the ring body decreased.

Example 4

Gold powder having an average particle size of 3. 1 ^ m and an average crystal particle size of 315 nm prepared by a water atomizing method As an organic binder, a 6% aqueous solution of methylcellulose and a mixed powder of tin oxide and aluminum oxide (70:30 by weight ratio) were prepared. Mix 98% gold powder and 2% of the above mixed oxide powder by weight, add 10% of the above methylcellulose aqueous solution by weight to the above mixed powder, and mix it. It was clay-like. The gold clay was filled in a ring-shaped mold, and after being molded and solidified, the molded body was dried at 100 ° C. or less for 30 minutes and subsequently sintered at 780 ° C. for 30 minutes to prepare a ring-shaped sintered body. . The obtained sintered body exhibited no cracks or deformation as small as 1.8% in average shrinkage ratio with respect to the size of the molded body before drying, and the strength was also sufficient. From this fact, it was found that by using this atomized gold powder, good gold clay can be obtained without using lead acid which has an influence on the environment and human body. The purpose of the drying step is to evaporate and remove the moisture and the organic binder in the molded body.

Example 5

[0058] Gold powder having an average particle diameter of 4.2 m and an average crystal particle diameter of 416 nm prepared by a water atomizing method, a 6% aqueous solution of ethylcellulose as an organic binder, magnesium oxide and calcium oxide Mixed powder (50: 50 by weight) was prepared. Blend 98% gold powder and 2% of the above mixed oxide powder on a weight basis, add 10% on a weight basis to this blended powder to the aqueous solution of ethyl cellulose, and mix the mixed powder It was clay-like. The gold clay was filled in a ring-shaped mold, and after being molded and solidified, the molded body was dried at 180 ° C. for 30 minutes and subsequently baked at 800 ° C. for 30 minutes to prepare a ring-shaped sintered body. The obtained sintered body exhibited no cracks or deformation as small as 2.1% of the average shrinkage ratio with respect to the size of the molded body before drying, and the strength was sufficient. From this, it was found that by using this atomized gold powder, good gold clay can be obtained without using lead oxide that affects the environment and human body. The purpose of the drying step is to evaporate and remove the moisture and the organic binder in the molded body.

As described above, the force for which the embodiment of the present invention has been described with reference to the drawings. The present invention is not limited to the illustrated embodiment. Various modifications and variations can be made to the illustrated embodiment within the same or equivalent scope of the present invention. Industrial applicability

The present invention can be advantageously used for gold powder and conductive gold paste and decorative gold clay using it.

Claims

The scope of the claims

[I] An atomized gold powder, which is a gold powder obtained by an atomization method, and having a crystal grain size of 100 to 800 nm (nm).

[2] The atomized gold powder according to claim 1, wherein the crystal grain size of the gold powder is 200 to 500 nm.

[3] The atomized gold powder according to claim 1, wherein the average particle size of the gold powder is 1 to: LO μm.

[4] The atomized gold powder according to claim 1, wherein the average particle size of the gold powder is 3 to 5 μm.

[5] The atomized gold powder according to claim 1, wherein the gold powder does not show expansion behavior in the sintering process!

[6] The atomized gold powder according to claim 1, wherein a contraction behavior start temperature in a sintering process of the gold powder is 350 ° C. or more.

[7] The atomized gold powder according to claim 1, wherein the melting point of the gold powder is 600 ° C. or higher.

[8] The atomized gold powder according to claim 1, wherein the melting point of the gold powder is 800 ° C. or higher.

[9] The atomized gold powder according to claim 1, wherein the gold powder is a water-atomized gold powder obtained by solidifying a fine droplet from a molten metal by spraying water.

[10] A conductive gold paste using the atomized gold powder according to claim 1.

[I I] A decorative gold clay using the atomized gold powder according to claim 1.

[12] The decorative gold clay comprises, in addition to the atomized gold powder, an organic binder solution and acid oxide particles,

The oxide particles may be selected from one or more of aluminum oxide, silicon oxide, tin oxide, calcium oxide, magnesium oxide, copper oxide and silver oxide. The ornamental gold clay according to claim 11, which is.