TWI438044B - A simple method for producing micro silver-copper composite powder - Google Patents

Description

A simple method for producing micron silver-copper composite powder

The invention relates to a method for preparing a silver-copper composite powder, in particular to a production process which is harmless to the environment and suitable for scale-up production.

The synthesis of micron and nano metal particles has been extensively studied and discussed in recent decades, and can be generally divided into three categories: liquid phase, gas phase and solid phase method. Among them, the synthesis of nano metal particles by liquid phase method has the advantage of setting cost compared with gas phase and solid phase method, so the present invention uses liquid phase chemical method as the production of submicron and nano copper powder. the way.

In the Republic of China Patent Publication No. I279269, "Microcapsule Solution Containing Nano Metals and Its Manufacturing Method", a method of manufacturing a nano metal polymer by a microcell method or an inverse microcell method is mentioned, and a patent of the Republic of China is also provided. Announcement No. I280949 "Manufacturing Method of Metallic Nanoparticles" mainly refers to a method of producing nano-metals by using biological methods and by plant photosynthesis; in addition, in the method of preparing nanoparticles, the Republic of China Patent Publication No. I290930, It is mainly mentioned that the production of nano-metals by the stencil method; and the method of manufacturing the metal nano-particles of the Republic of China Patent Publication No. I304101 is characterized in that the rod-shaped nano-particles are prepared by electrochemical type and adding a surfactant. Metal particles; and in the Republic of China Patent Publication No. I307646 "Nuclear-Shell Nanoparticles and Their Preparation Methods", mainly discussed The content is the preparation method of the core-shell type nanoparticle; in the Republic of China Patent Publication No. I307640, "Using the nano-scale powder forming method", the main part is the application part of the back end of the nano metal particle; the Republic of China patent announcement 201024004 No. "Silver-containing silver particles and a method for producing the same, and a dispersion thereof," are mainly discussed for the synthesis of nano-silver metal particles, wherein the nano silver particles synthesized by the method contain about 1 to 1000 ppm. The copper component, but the main purpose of adding copper is to improve the uniformity of the silver particles; in the method of manufacturing the silver-copper composite powder of the fine particle silver particles and the silver-copper composite powder of the fine particle silver particles, It mainly introduces silver-plated silver-copper powder with a silver content of about 30~70% with the strong reducing agent bisamine for controlling drugs. Another Republic of China Patent Announcement 200925291 "Nano silver-copper alloy slurry and nano silver-copper alloy In the preparation method of the powder, the silver salt and the copper salt are simultaneously added to the initial solution, and the expensive polymer protective agent is used to produce the nano-scale silver-copper alloy powder. In addition, the Republic of China Patent Publication No. 200831214, "Silver-plated copper micropowder, conductive paste made of silver-plated copper micropowder, and silver-plated copper micropowder", describes the use of surface treatment agents to enhance silver plating. In the way of efficiency, after multiple pickling and alkali washing, the calcination process is carried out in a reducing atmosphere after the silver plating process, and finally a silver-plated copper powder is obtained.

In summary, the prior art is different from the production method used in the present invention, and the manufacturing procedures mentioned in the above patents are not only complicated, but some of them also use controlled drugs.

The present invention relates to a method for preparing a silver-copper composite powder, which firstly comprises 0.01 to 0.45 wt%, a purity of 99% or more of sodium citrate, and 0.1 to 10 wt%, a median diameter (D). ₅₀ ) <10μm, purity of 99.5% or more of pure copper powder suspension, and control the stirring rate of 100~1200RPM to maintain the dispersion between the copper powder particles, in addition to a saturated concentration of 0.015M silver sulfate solution and add 0.05 in each ~1Vol.% and a concentration of 35% ammonium hydroxide with 0.05~5Wt.% and a purity of 99% or more of sodium citrate. After the pure copper powder suspension and the silver sulfate solution are all configured, the silver sulfate will be disposed. The solution is added to the pure copper powder suspension, and the reaction is continued for 5 to 60 minutes at a temperature of 30 to 120 ° C; the liquid is separated from the silver-copper composite powder by filtration, and then the obtained silver-copper composite powder is deionized water. After cleaning for 2~8 times, after 0.5~8 hours, 80~130°C drying process, the silver-copper composite powder with uniform particle size distribution (particle size range: 0.1~10μm) can be obtained.

The method for carrying out the invention is shown in the first figure. The following describes the implementation method for several ratios. The other Table 1 is for the silver-copper composite powder product synthesized by the patent and the commercially available pure silver product (Metalor, Switzerland). In comparison, the specific resistance test procedure is to transfer different powders into a specific colloid at a solid concentration of 50%. After being uniformly coated on a glass plate after being adjusted, the film was dried at 100 ° C for 10 minutes, and then the specific resistance value was measured by a micro-resistance meter.

(Embodiment 1)

First, 10L is contained in an amount of 0.01 to 0.45 wt% (preferably 0.05 to 0.18 wt%, more preferably 0.09 wt%), and the purity is 99% or more of sodium citrate, and 0.1 to 10 wt% (preferably 0.5 to 5 wt%, More preferably, it is 2.5 Wt%), a pure copper powder suspension having a median diameter (D ₅₀ ) of <10 μm and a purity of 99.5% or more, and a stirring rate of 100 to 1200 RPM (preferably 300 to 600 RPM) to maintain copper. The dispersion between the powder particles is additionally disposed with 34 L of a silver sulfate solution 12 having a saturation concentration of 0.015 M and added 0.05 to 1 Vol.% (preferably 0.1 to 0.25 Vol.%, more preferably 0.125 Vol.%) and concentration. 35% ammonium hydroxide and 0.05~5Wt.% (preferably 0.1~2.5Wt%, more preferably 0.25~1Wt%) and the purity of 99% or more of sodium citrate, the pure copper powder suspension 11 and sulfuric acid After the silver solution 12 is disposed, the silver sulfate solution 12 is added to the pure copper powder suspension 11 at a temperature of 2 to 30 to 120 ° C (preferably 40 to 100 ° C, more preferably 70 to 80 ° C). After the aging reaction 3 is carried out for about 5 to 60 minutes (preferably 10 to 30 ° C), the liquid is separated from the silver-copper composite powder 41 by the filtration process 4, and then the obtained silver-copper composite powder 41 is passed through a surface cleaning program. 5 wash with deionized water for 2~8 times (more After 4 times), the powder is dried by drying procedure 6 for 0.5-8 hours (preferably 1~2 hours) and 80-130 °C, and finally silver and copper with uniform particle size distribution can be obtained. Silver copper composite powder product with a ratio of 37:63 (particle size range: 0.1 to 10 μm).

(Embodiment 2)

First, 10L is contained in an amount of 0.01 to 0.45 wt% (preferably 0.05 to 0.18 wt%, more preferably 0.09 wt%), and the purity is 99% or more of sodium citrate, and 0.1 to 10 wt% (preferably 0.5 to 5 wt%, More preferably, it is 2.5 Wt%), a pure copper powder suspension having a median diameter (D ₅₀ ) of <10 μm and a purity of 99.5% or more, and a stirring rate of 100 to 1200 RPM (preferably 300 to 600 RPM) to maintain copper. The dispersion between the powder particles is additionally provided with 53 L of a silver sulfate solution 12 having a saturated concentration of 0.015 M and added 0.05 to 1 Vol.% (preferably 0.1 to 0.25 Vol.%, more preferably 0.125 Vol.%) and concentration. 35% ammonium hydroxide and 0.05~5Wt.% (preferably 0.1~2.5Wt%, more preferably 0.25~1Wt%) and the purity of 99% or more of sodium citrate, the pure copper powder suspension 11 and sulfuric acid After the silver solution 12 is disposed, the silver sulfate solution 12 is added to the pure copper powder suspension 11 at a temperature of 2 to 30 to 120 ° C (preferably 40 to 100 ° C, more preferably 70 to 80 ° C). After the aging reaction 3 is carried out for about 5 to 60 minutes (preferably 10 to 30 ° C), the liquid is separated from the silver-copper composite powder 41 by the filtration process 4, and then the obtained silver-copper composite powder 41 is passed through a surface cleaning program. 5 wash with deionized water for 2~8 times (more After 4 times), the powder is dried by drying procedure 6 for 0.5-8 hours (preferably 1~2 hours) and 80-130 °C, and finally silver and copper with uniform particle size distribution can be obtained. Silver copper composite powder product with a ratio of 53:47 (particle size range: 0.1 to 10 μm).

(Embodiment 3)

First, 10L is contained in an amount of 0.01 to 0.45 Wt% (preferably 0.05 to 0.18 Wt%, more preferably 0.09 Wt%), and the purity is 99% or more of sodium citrate, and 0.1 to 10 wt% (preferably 0.5 to 5 Wt%, More preferably, it is 2.5 Wt%), a pure copper powder suspension having a median diameter (D ₅₀ ) of <10 μm and a purity of 99.5% or more, and a stirring rate of 100 to 1200 RPM (preferably 300 to 600 RPM) to maintain copper. The dispersion between the powder particles is additionally provided with 120 L of a silver sulfate solution 12 having a saturated concentration of 0.015 M and added 0.05 to 1 Vol.% (preferably 0.1 to 0.25 Vol.%, more preferably 0.125 Vol.%) and concentration. 35% ammonium hydroxide and 0.05~5Wt.% (preferably 0.1~2.5Wt%, more preferably 0.25~1Wt%) and the purity of 99% or more of sodium citrate, the pure copper powder suspension 11 and sulfuric acid After the silver solution 12 is disposed, the silver sulfate solution 12 is added to the pure copper powder suspension 11 at a temperature of 2 to 30 to 120 ° C (preferably 40 to 100 ° C, more preferably 70 to 80 ° C). After the aging reaction 3 is carried out for about 5 to 60 minutes (preferably 10 to 30 ° C), the liquid is separated from the silver-copper composite powder 41 by the filtration process 4, and then the obtained silver-copper composite powder 41 is passed through a surface cleaning program. 5 wash 2~8 times with deionized water ( After 4 times), the powder is dried by drying procedure 6 for 0.5-8 hours (preferably 1~2 hours) and 80-130 °C, and finally silver and copper with uniform particle size distribution can be obtained. Silver copper composite powder product with a ratio of 73:27 (particle size range: 0.1 to 10 μm).

In order to make the present invention more apparent in its industrial applicability, the advantages of the present invention are enumerated as follows:

1. The invention does not require the addition of controlled drugs.

2. The operating procedure of the present invention is simple.

3. The price of the product of the invention is much lower than that of silver powder and is highly competitive in the market.

4. The invention has the potential to quantify production.

5. The silver-copper composite powder product of the invention can be used as a source of conductive materials for the PCB board, the conductive adhesive, the conductive paste and other manufacturers who need to use the silver-copper composite powder of this specification.

6. The invention can produce the utilization value of the silver-copper composite powder with different proportions according to different industries.

In summary, the invention has met the application requirements of the invention patent, and filed an application according to law, praying for the examination of the member of the bureau, and granting the patent right of the invention.

The first figure is the production process (flow chart) of the first example to the third micron silver-copper composite powder product.

The second figure is the result of electron microscopic analysis of the micron silver-copper composite powder obtained in the first embodiment (image image)

11‧‧‧ pure copper powder suspension

12‧‧‧ Silver sulfate solution

2‧‧‧ Temperature Control Program

3‧‧ ‧ ripening reaction

4‧‧‧Filtering procedures

41‧‧‧Silver copper composite powder

5‧‧‧Surface cleaning procedures

51‧‧‧Silver copper-copper composite powder after cleaning

6‧‧‧Drying procedure

7‧‧‧Silver copper composite powder products

Claims (5)

A simple method for producing micron silver-copper composite powder comprises the steps of: arranging sodium citrate in a pure copper powder suspension, the sodium citrate containing 0.01-0.45 wt% and 99% or more purity, the pure copper powder suspension Containing 0.1~10Wt%, medium particle size (D ₅₀ )<10μm and 99.5% purity; controlling the stirring rate is 100~1200RPM; arranging a silver sulfate solution, the silver sulfate solution has a saturation concentration of 0.015M; adding 0.05~ 1Vol.% one of ammonium hydroxide and 0.05~5Wt.%, more than 99% purity one of sodium citrate; the silver sulfate solution is added to the pure copper powder suspension, and the temperature is controlled at 30~120 °C The aging reaction is carried out for about 5 to 60 minutes; a liquid is separated from the silver-copper composite powder by a filtration process; the silver-copper composite powder is washed by deionized water through a surface cleaning procedure for 2 to 8 times; after a drying procedure, 0.5~ After 8 hours and 80 to 130 ° C, the powder is dried to obtain a silver-copper composite powder having a uniform particle size distribution. The method according to claim 1, wherein the silver sulfate solution having a saturation concentration of 0.015 M has a capacity of 34 L, 53 L and 120 L. The method of claim 2, wherein the silver-copper composite powder product has a ratio of silver to copper of 37:63, 53:47, and 73:27. The method of claim 3, wherein the silver-copper composite powder has a particle size ranging from 0.1 to 10 μm. The method of claim 1, wherein the ammonium hydroxide has a concentration of about 35%.