CN106862576A

CN106862576A - A kind of manufacture craft of flake silver powder

Info

Publication number: CN106862576A
Application number: CN201710202554.3A
Authority: CN
Inventors: 李程峰; 韩玉成; 龚漫莉; 邵振宇; 胡滔
Original assignee: China Zhenhua Group Yunke Electronics Co Ltd
Current assignee: China Zhenhua Group Yunke Electronics Co Ltd
Priority date: 2017-03-30
Filing date: 2017-03-30
Publication date: 2017-06-20

Abstract

The invention discloses a kind of, manufacture craft of flake silver powder, comprise the following steps：Step 1, the silver powder that will be cleaned up, i.e. silver powder water conductivity are less than 100uS/m, add dispersant；Step 2, will add the silver powder of dispersant to be put into oven for drying；Step 3, plays powder dispersion；Step 4, roller mill is carried out with the steel ball of diameter 10mm in stainless cylinder of steel, and the agglomerate reunited is clapped and dissipated by each hour, altogether roller mill 8h；Step 5, discharging；Present invention eliminates vacuum drying process, add 0.6 0.7% dispersant by flake silver powder drying time by original 48 hours before baking, be reduced to 16 hours, shorten the production cycle so that producing efficiency is higher.

Description

A kind of manufacture craft of flake silver powder

Technical field

The invention belongs to a kind of manufacture craft of flake silver powder.

Background technology

Flake silver powder is filled primarily with material for the low-temperature solidified silver pastes such as impregnated silver pulp, conducting resinl, and its production cycle is more long, Process step design is more, therefore its stability embodies the resonable degree of technological parameter and technical process, current flake silver powder Production process include：Reduction → 24h vacuum dehydrations → 16h, 70 DEG C of drying → ball milling → detections, at least 5 days its production cycle, Along with 5 day production cycle of low-temperature solidified silver paste so that low production efficiency.

The content of the invention

Goal of the invention：The present invention provides a kind of manufacture craft of flake silver powder, and the manufacture craft shortens the cycle of production, To reach expeditiously complete and make.

Technical scheme：A kind of manufacture craft of flake silver powder, comprises the following steps：

Step 1, the silver powder that will be cleaned up, i.e. silver powder water conductivity are less than 100uS/m, add dispersant to be sufficiently stirred for, Ensure that dispersant is fully mixed with silver powder；

Step 2, will add the silver powder of dispersant to be put into drying tray, silver powder is laid in drying tray with uniform thickness, And it is put in drying in baking oven；

Step 3, powder dispersion is fully played with mechanical crusher；

Step 4, roller mill is carried out with the steel ball of diameter 10mm in stainless cylinder of steel, and the agglomerate reunited is clapped and dissipated by each hour, Roller grinds 8h altogether；

Step 5, discharging.

Specifically, dispersant uses hexadecanol or stearic acid in the step 1.

Specifically, the addition of dispersant is 0.6-0.7% in the step 1.

Specifically, drying time is 16h in the step 2.

Specifically, drying temperature is 60-90 degree in the step 2.

Beneficial effect：Compared with prior art, the advantage of the invention is that：The manufacture craft eliminates vacuum drying mistake Journey, before baking add 0.6-0.7% dispersant by flake silver powder drying time by original 48 hours, be reduced to 16 small When, shorten the production cycle so that producing efficiency is higher.

Brief description of the drawings

Fig. 1 is prior art particle size distribution figure；

Fig. 2 is the application particle size distribution figure.

Specific embodiment

With reference to the accompanying drawings and detailed description, the present invention is furture elucidated.

A kind of manufacture craft of flake silver powder, comprises the following steps：

Step 1, the silver powder that will be cleaned up, i.e. silver powder water conductivity are less than 100uS/m, add dispersant to be sufficiently stirred for, Ensure that dispersant is fully mixed with silver powder, dispersant uses hexadecanol or stearic acid etc waxy substance, the addition of dispersant It is 0.6-0.7%, optimal addition is 0.6%；

Step 2, will add the silver powder of dispersant to be put into drying tray, silver powder is laid in drying tray with uniform thickness, And 60-90 degree drying in baking oven is put in, drying time is 16h；

Step 3, powder dispersion is fully played with mechanical crusher；

Step 4, roller mill, the agglomerate that each hour will be reunited with spades are carried out with the steel ball of diameter 10mm in stainless cylinder of steel Clap and dissipate, altogether roller mill 8h；

Step 5, discharging.

The application cancels the vacuum drying process after silver powder reducing process first, is directly dried using normal pressure, and to drying Time is recorded, and the scaling loss of powder tests to determine whether powder fully dries after to drying；By experiment The optimal time for solving direct normal pressure drying is 16h.

Due to eliminating vacuum drying process, the residual volume of dispersant is more than the 0.3% of conventional technique in silver powder after drying, Reach 0.7%；Excessive residual dispersant causes silver powder hardened in mechanical milling process, causes the only hardened block silver of surface portion Powder rapid flaking by the abrading-ball effect of being rolled, the silver powder flaking time of hardened piece of inside then will accordingly increase, finally Cause the excessive flaking of surface portion silver powder, or even produce the thick silver strip of reunion state and silver-colored pearl, so as to increase the flat of flake silver powder Equal particle diameter.In order to solve this problem, we reduce the addition of dispersant in reduction process, and have carried out ball milling reality Test, so as to obtain optimal dispersant addition for 0.6%-0.7%.

In order to analyze the variation tendency of silver powder particle diameter in mechanical milling process, we are in mechanical milling process with the frequency of 1h to silver Powder is sampled, and is tested by the particle diameter for sampling, and silver powder is disperseed by abrading-ball first in mechanical milling process, and average grain diameter gradually subtracts It is small, start flaking occur after 3h, average grain diameter kept stable between 7-9h, therefore we determined that ball-milling technology most The good time maintains the 8h of former technique.

Confirmed through overtesting, the application carries out piece powder and produces 14 batches altogether before completing, wherein there are 6 batches of average grain diameters to exceed standard Upper limit 8um, in this six batches there is the silver-colored agglomerated particle more than 100um in the two batches of most serious, it is impossible to normally use in the slurry, must Sieving treatment must be carried out, Fig. 1 is the batch particle size distribution figure before this experiment is completed；After the completion of this experiment, 6 batches of sheet silver are produced altogether Powder, its average grain diameter meets critical field, and its distribution situation is as shown in Figure 2.

By Fig. 1 and Fig. 2 contrasts it can be seen that the method that the application is used can effectively solve flake silver powder batch stabilization Property difference problem, and greatly reduce the flake silver powder production time.

Claims

1. a kind of manufacture craft of flake silver powder, it is characterised in that comprise the following steps：

Step 1, the silver powder that will be cleaned up, i.e. silver powder water conductivity are less than 100uS/m, add dispersant to be sufficiently stirred for, it is ensured that Dispersant is fully mixed with silver powder；

Step 2, will add the silver powder of dispersant to be put into drying tray, silver powder is laid in drying tray with uniform thickness, and put Dried in baking oven；

Step 3, powder dispersion is fully played with mechanical crusher；

Step 4, roller mill is carried out with the steel ball of diameter 10mm in stainless cylinder of steel, and the agglomerate reunited is clapped and dissipated by each hour, altogether roller Mill 8h；

Step 5, discharging.

2. the manufacture craft of a kind of flake silver powder according to claim 1, it is characterised in that：Dispersant in the step 1 Using hexadecanol or stearic acid.

3. the manufacture craft of a kind of flake silver powder according to claim 1, it is characterised in that：Dispersant in the step 1 Addition be 0.6-0.7%.

4. the manufacture craft of a kind of flake silver powder according to claim 1, it is characterised in that：When being dried in the step 2 Between be 16h.

5. the manufacture craft of a kind of flake silver powder according to claim 1, it is characterised in that：Temperature is dried in the step 2 It is 60-90 degree to spend.