CN1704191A

CN1704191A - Silver-copper alloy powder and preparation method thereof

Info

Publication number: CN1704191A
Application number: CN 200410037057
Authority: CN
Inventors: 曹晓国; 吴伯麟
Original assignee: Guilin University of Technology
Current assignee: Guilin University of Technology
Priority date: 2004-05-25
Filing date: 2004-05-25
Publication date: 2005-12-07

Abstract

The invention discloses a copper-silver alloy power and it's preparing method. The copper-silver alloy power is a mixing alloy power of sheet alloy power S.Ag(Cu). with crystal size at 10- 15m and annular alloy power S.Cu(Ag). with crystal size at 1-4m, wherein the mass percent of silver content is 50-95%, and the mass percent of copper content is 5-50%. It adopts liquid phase reduction and uses ascorbic acid to reduce Cu.2+. and Ag.+. to prepare copper-silver alloy power, and uses high polymer distinction to improve the collecting condition of the powder.

Description

A kind of cu-ag alloy powders and preparation method thereof

Technical field

The present invention relates to a kind of cu-ag alloy powders and preparation method thereof.

Background technology

Conductive filler is as the important component part of conducing composite material, and its performance, pattern and size distribution all directly affect the electric conductivity and the stability thereof of conducing composite material.Generally speaking, the particle diameter of conductive filler is more little, and the electric conductivity of conducing composite material is good more, this is that its specific area increases, and is in contact with one another a little and also increases because along with the reducing of conductive filler granularity, the possibility that forms three-dimensional conduction network chain increases, so the specific insulation of material reduces.The electric conductivity of sheet conductive filler is better than the electric conductivity of spherical conductive filler, mainly is a contact between spherical conductive filler, and mainly is the face contact between the sheet conductive filler, helps the conduction of electric charge.Size distribution is uneven and have the conductive filler that exists than granule to help improving the electric conductivity of conducing composite material.This is owing to there being some very little spaces between conducting particles bigger in the conductive material, the conducting particles that granularity is little can be filled these spaces effectively, increase intergranular contact point, conductive channel is increased, and reduce intergranular separation layer, reduce electronics and pass through the obstruction of separation layer, thereby the electric conductivity of conducing composite material is improved.

Silver is that conductive filler is the conductive filler of developing the earliest, it has good electric conductivity and oxidative resistance, but under the effect of DC voltage, the transport phenomena of Yi Fashengyin and cause short circuit, this has become electronic product march toward miniaturization, highly integrated a great problem.The copper powder low price, anti-migration performance is much higher than silver, and has good electric conductivity, but it is easily oxidized in preparation and application process, and the electric conductivity of conducing composite material is weakened.For improving the non-oxidizability of copper powder, more to the research of silver-plated copper powder both at home and abroad, but by the very difficult complete coating that realizes copper powder of reduction Ag+, and the surface irregularity of the silver-plated copper powder of preparation, this has influenced its non-oxidizability and electric conductivity to a great extent.

Summary of the invention

The present invention is directed to above problem, a kind of cu-ag alloy powders and preparation method thereof is provided, prepared cu-ag alloy powders is the sheet alloyed powder S of particle diameter 10～15m _{Ag (Cu)}The spherical alloyed powder S of (copper forms the discontinuous solid solution of rich silver in silver-colored crystal) and particle diameter 1～4m _{Cu (Ag)}The hybrid alloys powder of (silver forms the discontinuous solid solution of rich copper in copper crystal), it has good environment resistant and electric conductivity, it is the desirable conductive filler of conducing composite material, be particularly suitable for conductance and require high, the stable environment of performance requirement, as electromagnetic-shielding conductive coating, surface-assembled conducting resinl.

The content of silver is 50～95% in the above-mentioned cu-ag alloy powders, and the content of copper is 5～50%, more than is mass percent.

The preparation method of above-mentioned cu-ag alloy powders provided by the invention is: prepare certain density CuSO respectively ₄And AgNO ₃Solution is pressed CuSO ₄With AgNO ₃Certain ratio of mol ratio is mixed in the reactor, and adds a certain amount of macromolecule dispersing agent, with mixed liquor constant temperature in 50～90 ℃ of reaction temperatures; Compound concentration is the ascorbic acid solution of 0.5～2mol/L in another container, under agitation ascorbic acid solution is pressed ascorbic acid molal quantity and CuSO ₄And AgNO ₃The ratio of molal quantity sum equals 1～1.4: 1 ratio and is added drop-wise in the reactor, and reaction 20～60min washes the powder that makes with water, and the gained powder is 40～80 ℃ of oven dry in vacuum drying oven, promptly get required cu-ag alloy powders.

Above-mentioned CuSO ₄With AgNO ₃Mol ratio 0.3～9: in 1 the scope.

Above-mentioned macromolecule dispersing agent is a kind of among gelatin, PVP, the PVA, and its consumption is used CuSO ₄And AgNO ₃2～20% of gross mass.

The specific embodiment

Embodiment 1: compound concentration is the CuSO of 0.2mol/L respectively ₄And AgNO ₃Solution is pressed CuSO ₄With AgNO ₃Mol ratio is that 1: 1 ratio is mixed in the reactor, and adds 8% PVP, with mixed liquor constant temperature in 70 ℃.Compound concentration is the ascorbic acid solution of 1.20mol/L in another container.Under agitation ascorbic acid solution is pressed ascorbic acid molal quantity and CuSO ₄And AgNO ₃The ratio of molal quantity sum equals 1.2: 1 ratio and is added drop-wise in the reactor, and reaction 40min gives a baby a bath on the third day after its birth the powder water that makes time, and the gained powder is 80 ℃ of oven dry in vacuum drying oven, promptly get required cu-ag alloy powders.Prepared cu-ag alloy powders is the sheet alloyed powder S about particle diameter 15m _{Ag (Cu)}With the spherical alloyed powder S about particle diameter 2m _{Cu (Ag)}The hybrid alloys powder; Wherein Yin content is about 75%, and the content of copper is about 25%, more than is mass percent.This cu-ag alloy powders does not increase weight at 300 ℃ of calcining 15min; Behind 700 ℃ of calcining 15min, only increase weight 0.227%, and contact resistance value is 0.3 Ω (the universal meter internal resistance value is 0.3 Ω).

Embodiment 2: remove CuSO ₄Concentration is that all the other prescriptions, reaction condition and step are with embodiment 1 outside the gelatin of 0.05mol/L, adding 5%.Prepared cu-ag alloy powders is the sheet alloyed powder S about particle diameter 13m _{Ag (Cu)}With the spherical alloyed powder S about particle diameter 2m _{Cu (Ag)}The hybrid alloys powder; Wherein Yin content is about 80%, and the content of copper is about 20%, more than is mass percent.This cu-ag alloy powders increases weight 1.209% behind 300 ℃ of calcining 15min, but contact resistance value still is 0.3 Ω (the universal meter internal resistance value is 0.3 Ω).

Embodiment 3: except that reaction temperature is 60 ℃, all the other prescriptions, reaction condition and step are with embodiment 1.Prepared cu-ag alloy powders is the sheet alloyed powder S about particle diameter 15m _{Ag (Cu)}With the spherical alloyed powder S about particle diameter 3m _{Cu (Ag)}The hybrid alloys powder; Wherein Yin content is about 85%, and the content of copper is about 15%, more than is mass percent.This cu-ag alloy powders does not increase weight at 700 ℃ of calcining 15min, and contact resistance value is 0.3 Ω (the universal meter internal resistance value is 0.3 Ω).

Claims

1. a cu-ag alloy powders is characterized in that cu-ag alloy powders is the sheet alloyed powder S of particle diameter 10～15m _{Ag (Cu)}The spherical alloyed powder S of (copper forms the discontinuous solid solution of rich silver in silver-colored crystal) and particle diameter 1～4m _{Cu (Ag)}The hybrid alloys powder of (silver forms the discontinuous solid solution of rich copper in copper crystal); Wherein Yin content is 50～95%, and the content of copper is 5～50%, more than is mass percent.

2. the preparation method of the described cu-ag alloy powders of claim 1 is characterized in that: prepare certain density CuSO respectively ₄And AgNO ₃Solution is pressed CuSO ₄With AgNO ₃Certain ratio of mol ratio is mixed in the reactor, and adds a certain amount of macromolecule dispersing agent, with mixed liquor constant temperature in 50～90 ℃ of reaction temperatures; Compound concentration is the ascorbic acid solution of 0.5～2mol/L in another container, under agitation ascorbic acid solution is pressed ascorbic acid molal quantity and CuSO ₄And AgNO ₃The ratio of molal quantity sum equals 1～1.4: 1 ratio and is added drop-wise in the reactor, and reaction 20～60min washes the powder that makes with water, and the gained powder is 40～80 ℃ of oven dry in vacuum drying oven, promptly get required cu-ag alloy powders.

3. as the preparation method of right 2 described cu-ag alloy powderses, it is characterized in that used CuSO ₄With AgNO ₃Mol ratio 0.3～9: in 1 the scope.

4. as the preparation method of right 2 described cu-ag alloy powderses, it is characterized in that used macromolecule dispersing agent is a kind of among gelatin, PVP, the PVA, its consumption is used CuSO ₄And AgNO ₃2～20% of gross mass.