Micron-scale silver chloride for electronic probe and preparation method of micron-scale silver chloride

Abstract

The invention discloses micron-scale silver chloride for an electronic probe and a preparation method thereof.The preparation method comprises the steps that a dispersing agent solution is added into a receiving tank of a reaction kettle, stirring is started, then a chlorine salt solution and a complexing agent / silver salt solution are added into a pipeline reactor, the angle of the pipeline reactor is controlled to range from 15 degrees to 20 degrees, and the length of the pipeline reactor can be adjusted according to the needed particle size; when the reaction is started, a coating agent solution is dropwise added into the receiving tank according to a certain proportion; and the reaction solution is subjected to alcohol cleaning, centrifugal dewatering, vacuum drying and crushing, and then micron-sized silver chloride powder with the stable particle size can be obtained. An existing reaction kettle type liquid phase reduction method is not adopted, the pipeline reactor is combined with reaction time and temperature, and process amplification mass production can be achieved. According to the method, the pipeline reactor which is non-toxic, pollution-free, low in energy consumption, easy to operate and capable of achieving continuous production is adopted, the micron-sized silver chloride powder with excellent dispersity is obtained, and the method is suitable for silver chloride electronic probes and silver chloride alloy materials.

Description

Technical Field

[0001] The invention relates to a preparation method for continuous production of micron-level silver chloride powder, belonging to the field of micro-nano material preparation. Background Art

[0002] Metallic silver has excellent physical and chemical properties. At present, a lot of technical research has been done in China on silver powder in the photovoltaic field, and the main use is in photovoltaic silver powder. However, silver salt products are widely used in special alloys, special electrodes, medical electrodes and other fields. For a long time, there has been no research on related silver salt projects in China, resulting in the development of the silver salt series basically staying in the experimental stage and unable to meet the needs of mass production. There are relatively few manufacturers specializing in silver series in the domestic market, and they basically rely on imports. Among them, the emergence of micron-level silver chloride powder has taken a big step forward in the technical research of silver powder, and has a more significant role in replacing imports, and has broad prospects.

[0003] At present, the preparation methods of micro-nano materials can be simply divided into physical methods and chemical methods. The physical method requires large investment and low efficiency. Manufacturers on the market rarely use physical methods to produce nano-level powder materials. The current mainstream reaction system is still the liquid phase reduction and replacement system, and the liquid phase system is currently the most in-depth and thorough reaction system studied in China. The equipment, process, operation, etc. of this method are relatively simple and controllable. However, the current preparation method of micron-level silver chloride powder also has many defects, such as instability between batches, low yield, and the reaction system is affected by many factors, resulting in product defects. In addition, there are theoretical deviations in the design of traditional stirring paddle reactors, which makes the growth and nucleation of powders unstable during the reaction process. Therefore, it is particularly important to develop a simple, stable, continuous and efficient production reaction system. Summary of the invention

[0004] The present invention overcomes the technical prejudice of the prior art that micron-sized silver chloride powder is prepared by reaction in a reactor, and adopts a straight tube reactor. The length of the pipeline satisfies the requirements of the change of reaction time, and the particle size can be accurately controlled, and the stability is better. In order to solve the problem that the particle size is unstable as the amount of material input increases in the traditional liquid phase method, and the overall reaction cannot be enlarged, the present invention provides a reaction system with controllable particle size, which is not subject to the problems of poor crystal dispersion and different morphologies caused by the increase in the reaction amount. The solution temperature, reaction time and reaction concentration of the reaction system are uniform, the particle size is stable, the dispersibility is good, and the operation is simple and efficient, and it is suitable for continuous production.

[0005] The present invention adopts the following technical scheme.

[0006] A method for preparing micron-level silver chloride for an electronic probe comprises the following steps:

[0007] (1) mixing a complexing agent with a silver salt aqueous solution to prepare a solution E having a pH between 9 and 10;

[0008] (2) mixing the dispersant with water to obtain solution B;

[0009] (3) A soluble chloride salt or hydrochloric acid is added to water to obtain solution C;

[0010] (4) mixing the coating agent and the solvent to obtain a solution D;

[0011] (5) Through the pipeline reactor, solution E and solution C are simultaneously added dropwise to the reactor receiving tank containing solution B and solution D, and then coated to obtain micron-level silver chloride for electronic probe.

[0012] In the present invention, solution B is stirred in a reactor receiving tank until bubbles appear on the surface, then solution D is added dropwise, stirring is maintained, and then solution E and solution C are added dropwise through a pipeline reactor at the same time, and then coated; after coating, the solution is centrifugally dehydrated, vacuum dried, and crushed to obtain micron-level silver chloride for an electronic probe. Specifically, after coating, the solution is centrifugally dehydrated to obtain a solid, and the solid is vacuum dried and crushed to obtain the micron-level silver chloride for the electronic probe; the steps after coating are conventional techniques. Preferably, the stirring speed is controlled at 150-300 r / min, and the surface bubble height is 10-20 cm; the dripping speed of solution E is 30-80 ml / min, preferably 40-60 ml / min, the dripping speed of solution C is 10-50 ml / min, preferably 20-40 ml / min, and the inclination angle of the pipeline reactor is 10°-20°, preferably 15°-20°.

[0013] In the present invention, the silver salt aqueous solution is solution A, and its pH is controlled between 4-4.8. A complexing agent is added to complex the silver ions, and the reaction speed and nucleation conditions of the silver salt solution are controlled; the silver content in solution A is between 4% and 8%, which refers to the mass content, wherein the silver salt can be silver nitrate or silver acetate, preferably silver nitrate. The complexing agent generally uses disodium EDTA and ammonia water. In order to avoid the introduction of new ions into the powder, which makes it difficult to clean the silver nitrate, the present invention preferably uses ammonia water to form a silver ammonia solution complex; when the complexing agent is mixed with the silver salt aqueous solution, the end point is that the solution E is clear and transparent, and the pH is controlled between 9 and 10.

[0014] In the present invention, the dispersant can be triethanolamine oleic acid soap, gelatin, polyvinyl pyrrolidone, polyvinyl alcohol, Indek H8302, preferably H8302. The dispersant is used in a proportion of 3% to 6% of the weight of the silver salt. In solution B, the weight ratio of the dispersant to water is 1:20 to 25.

[0015] In the present invention, the soluble chloride salt may be sodium chloride or potassium chloride, and hydrochloric acid is preferred to avoid the introduction of new ions. In solution C, the mass ratio of chloride salt or hydrochloric acid to water is between 1:10 and 15.

[0016] In the present invention, the coating agent is stearic acid or lauric acid, and the solvent is alcohol or isopropanol; the amount of the coating agent is between 3% and 5% of the weight of the silver salt; in solution D, the weight ratio of the coating agent to the solvent is between 1:50 and 70.

[0017] The present invention adds solution B into a reactor receiving tank under the condition of 20-25°C, starts stirring, controls the stirring speed at 150-300r / min, starts dripping the prepared coating agent solution D after the foaming height of the dispersant surface is 10-20cm, preferably 12-17cm, controls the dripping speed of the coating agent at 60ml / min, starts dripping solution E and solution C at the same time after dripping for 5min, enters the receiving tank after passing through a pipeline reactor, wherein the dripping speed of solution E is 50ml / min, the dripping speed of solution C is 30ml / min, the inclination angle of the pipeline reactor is 15°, and the reacted solution enters the receiving tank, and directly performs coating to obtain highly dispersible silver chloride powder. Further, after coating for 1-5min, the upper liquid level discharge port of the reactor is opened to perform continuous discharging, and when the material reaction is finished, the bottom valve is opened to completely discharge the powder solution obtained by the remaining reaction, and the material is centrifugally dehydrated, vacuum dried, and crushed to obtain a finished product.

[0018] As an example, the method for preparing the above-mentioned highly dispersible micron-sized silver chloride powder of the present invention comprises the following steps:

[0019] (1) Soluble silver salt is dissolved in pure water, uniformly prepared in a preparation tank, and the silver ion concentration is tested; the solution pH is controlled between 4-4.8, a complexing agent is added to complex the silver ions, and the reaction speed and nucleation conditions of the silver salt solution are controlled;

[0020] (2) Dispersant and pure water are mixed in a ratio of 4% and added to the reactor receiving tank. Stirring is started at a speed of 300 r / min. When the bubble height reaches 15 cm, the prepared coating agent solution D is added dropwise. After the temperature is controlled at 25° C., the reaction is started.

[0021] (3) Through the pipeline reactor, the length of the pipeline reactor is selected to be 15 cm, and a spiral spoiler is added inside the pipeline to control the reaction time. The temperature of the silver salt solution and the chloride salt solution are both controlled at 20°C, wherein the dropping speed of solution E is 50 ml / min, and the dropping speed of solution C is 30 ml / min. The inclination angle of the pipeline reactor is 15°. After the solution passing through the pipeline reactor enters the reactor receiving tank, it is immediately coated. After coating for 2 minutes, the liquid level discharge port on the reactor is opened to continuously discharge the material. When the material reaction is completed, the bottom valve is opened to discharge all the powder solution obtained by the remaining reaction. The material can be obtained after centrifugal dehydration, vacuum drying and crushing.

[0022] The invention discloses micron-level silver chloride for electronic probes prepared according to the preparation method, and application of the micron-level silver chloride for electronic probes in preparing silver chloride electronic probes and silver chloride alloy materials.

[0023] Compared with the traditional liquid phase method, the pipeline reaction method of the present invention has the advantages of good stability and continuous production. From the reaction data, if it is a traditional reactor for feeding reaction mode, as the material input amount increases, the particle size will be unstable, and the overall reaction cannot be enlarged. When the material addition amount exceeds 15kg / batch, the reaction D50 basically cannot be controlled. However, the pipeline reactor will not have such problems. The pipeline reactor is a continuous production. As time goes by, the particle size basically fluctuates slightly and will not fluctuate greatly. Therefore, the present application system selects a pipeline reactor for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of a straight tube reactor according to an embodiment of the present invention;

[0025] Figure 2 This is an electron microscope image of wet powder obtained using a pipeline reactor;

[0026] Figure 3 This is an electron microscope image of wet powder obtained using a pipeline reactor;

[0027] Figure 4 This is an electron microscope image obtained after drying and crushing using a pipeline reactor, a 10μm reference electron microscope image;

[0028] Figure 5 This is an electron microscope image obtained after drying and crushing using a pipeline reactor, and a 5μm reference electron microscope image. DETAILED DESCRIPTION

[0029] Conventional powder material manufacturing generally has a maximum of 10kg per batch. After the reaction of this batch is completed, the material needs to be discharged and then fed back for the next batch. The continuous production of the present invention means that the product is continuous, and the reaction can continue as long as there is enough solution.

[0030] The method for preparing the highly dispersible spherical micron-sized silver chloride powder disclosed in the present invention comprises the following steps:

[0031] (1) dissolving a soluble silver salt in pure water in a certain proportion to obtain a solution A, wherein the silver salt comprises silver nitrate, and the mass content of silver in the solution A is between 4% and 8%;

[0032] (2) adding a dispersant to pure water in a certain proportion to obtain solution B: the dispersant is triethanolamine oleic acid soap, gelatin, polyvinyl pyrrolidone K60, polyvinyl pyrrolidone K90, polyvinyl alcohol or Indek H8302; the dispersant is used in a proportion of 3% to 6% of the weight of the silver salt, and the weight ratio of the dispersant to pure water is between 1:20 and 1:25;

[0033] (3) Soluble chloride salt or hydrochloric acid is added to pure water to prepare soluble C, wherein the chloride salt is sodium chloride; the volume ratio of chloride salt or hydrochloric acid to pure water is between 1:10 and 1:15;

[0034] (4) preparing a coating agent into a solution D, wherein the coating agent is stearic acid or oleic acid, the solvent is alcohol or isopropanol, the amount of the coating agent is between 3% and 5% of the weight of the silver salt, and the weight ratio of the coating agent to the solvent in the solution preparation is between 1:50 and 1:70;

[0035] (5) Adding a complexing agent to solution A in a certain proportion, wherein the complexing agent is generally EDTA disodium and ammonia water. In order to avoid introducing new ions into the powder, which makes it difficult to wash the silver nitrate, ammonia water is preferably used to form a silver ammonia solution complex. The addition ratio is 1:1, and the end point is when solution E becomes clear and transparent, and the pH is controlled between 9 and 10;

[0036] (6) At 20-25°C, add solution B to the reactor receiving tank, start stirring, and control the stirring speed at 150-300r / min. After the bubble height of the dispersant surface is 15cm, start dripping the prepared coating agent solution, and control the dripping speed of the coating agent at 60ml / min. After dripping for 5min, you can start dripping solution E and solution C at the same time, and enter the receiving tank after passing through the pipeline reactor, wherein the dripping speed of solution E is 50ml / min, and the dripping speed of solution C is 30ml / min. The inclination angle of the pipeline reactor is 15°. After the reaction is completed, the solution enters the receiving tank, and directly coats to obtain highly dispersed silver chloride powder. Further, after coating for 1-5min, open the liquid level discharge port on the reactor to discharge continuously (as common sense, the diameter of the discharge port is larger than the diameter of the feed port, as long as the liquid level is basically within a certain range), and the material is centrifuged, vacuum dried, and crushed to obtain the finished product.

[0037] The raw materials used in the present invention are all existing products, and the specific preparation operations and performance tests are all conventional technologies. The determination of the foam thickness is conventional technology: the water inlet into the reactor is a standard value, and there is a scale at 15 cm above the liquid surface, and the foam height is observed according to the scale. The particle size is tested with the dispersion of the reaction system, and the particle size detector is a Malvern particle size tester.

[0038] In the present invention, the straight tube reactor is a tube structure with a spiral spoiler inside. The main structure is a dn20 or dn25 glass tube. The upper end and the left side of the glass tube correspond to solution inlets with a diameter of 1-2 cm respectively. The two solutions enter the addition port through a flow meter. The solutions react in contact inside the pipe. A spoiler is added below the inlet mainly to allow the two solutions to mix better. The shape of the specific spoiler is conventional technology, and those skilled in the art design it according to production applications; the straight tube reactor is conventionally connected to the feed port of the reactor receiving tank. See Figure 1 , is a schematic diagram of the structure of a straight tube reactor according to an embodiment of the present invention, A is a solution inlet with a diameter of 2 cm, and B is a solution inlet with a diameter of 1 cm.

[0039] Embodiment 1 A method for preparing micron-level silver chloride for electronic probe comprises the following steps.

[0040] Prepare silver nitrate solution, with 10L of pure water for every kilogram, and add 100kg of silver salt at one time. After the proportion is completed, stir for 15 minutes and test the pH value of the solution. The pH value of the solution is between 4-4.8; then add complexing agent ammonia water to adjust the pH of the solution. When the solution becomes clear and transparent and the pH reaches between 9-10, the preparation of silver salt solution E is completed.

[0041] To prepare the chloride-containing salt solution, add 80 L of 37.5% analytical pure hydrochloric acid to 1000 L of pure water to prepare chloride salt solution C.

[0042] Solution D was obtained by mixing coating agent oleic acid and isopropanol in a certain ratio, wherein 30 g of coating agent was dissolved in 100 ml of isopropanol.

[0043] Prepare 200L solution of dispersant H8302 according to 5% mass ratio (5Kg) and add it into the reactor receiving tank, start stirring, adjust the stirring speed to 300r / min, and when the bubble thickness reaches 15cm, start dripping the prepared coating agent solution, and the dripping speed of the coating agent is controlled at 60ml / min. After dripping for 5min, solution E and solution C are dripped at the same time, and enter the receiving tank after passing through the pipeline reactor, where the dripping speed of solution E is 50ml / min, and the dripping speed of solution C is 30ml / min. The speed is controlled by the flow meter, and it enters the reactor with an inclination angle of 15° at the same time to react, and then enters the receiving tank for coating.

[0044] After coating for 2 minutes, the reactor receiving tank is opened to discharge the material, and the liquid containing the silver chloride powder enters a flat centrifuge (a solid-liquid separator can also be used) for dehydration. After the dehydration is completed, the powder is washed with ethanol. After the washing is completed, the amount of the coating agent is less than 3%, and the amount of the coating agent is measured by high-temperature burning loss.

[0045] The silver chloride test results obtained by the above method are as follows (the length of this reactor is 25 cm and the reaction time in the pipeline is 1.2 s):

[0046]

[0047] The electron microscope images of this result are shown below. Figure 1 , Figure 2 , is the wet powder particle size obtained by using a pipeline reactor. Since it has not undergone conventional post-processing procedures, slight agglomeration is normal. As can be seen from the figure, the powder has good uniformity, reasonable particle size distribution, and the pipeline reactor can well avoid the uncontrollable factors at the back end caused by traditional reactors. Figure 3 , Figure 4 , is the particle size obtained after drying and crushing in a pipeline reactor. As can be seen from the figure, the particle size of the powder is basically spherical, the particle size is relatively uniform, and it is also within the control range, which is essentially different from the traditional silver chloride precipitation.

[0048] The pipeline reactor determines the reaction time. Referring to the above method, the particle size distribution obtained after pipeline reactors of different lengths is preferably 20-30 cm in length. The specific particle size results are as follows:

[0049]

[0050]

[0051] Embodiment 2

[0052] A continuous reaction was carried out on the basis of the embodiment, that is, after coating for 2 minutes, the reactor receiving tank was opened to discharge the material for post-processing, and the raw material was continued to be added dropwise. The results corresponding to different continuous reaction times are as follows, and 85 kg can be produced in 2 hours.

[0053]

[0054] According to the method of the present invention, the pipeline flow rate is 300L-500L per hour, and the corresponding solution is configured according to the size of the configuration kettle. The configuration kettle is selected to be 3000L, and 200kg of silver nitrate solution is configured to correspond to 1800-2000L of water, that is, 4h-6h is needed to complete the preparation of 1800-2000L of solution, and 170kg of finished product can be obtained with good particle size uniformity. Compared with the traditional reactor, a maximum of 12 batches can be made in 6h, and the maximum production capacity is only 36kg, which greatly improves the production efficiency.

[0055] Comparative Example 1

[0056] Traditional liquid phase reduction method: The main steps are to prepare the reducing agent, coating agent and dispersant according to the amount of silver salt, use the dispersant as the base liquid, and add the silver salt solution and the reducing agent to the reaction system at the same time. The traditional liquid phase reduction kettle system generally adopts the method of first preparing 30L of 10% silver nitrate solution in the kettle, adding the complexing agent (ammonia water) for complexation, the ratio is 1:1 (with the mass ratio of silver nitrate), and preparing 10L of hydrochloric acid with a mass concentration of 13%. 3% (reference silver nitrate weight) of dispersant H8302 is prepared into an aqueous solution and added to the reactor, stirring is turned on, and after stirring for 5 minutes, the speed is adjusted to 300r / min, and the silver nitrate complexing solution and hydrochloric acid solution are added at the same time, and the addition is completed within 2 minutes. After the addition is completed, stirring is continued for 3 minutes, and then oleic acid with a mass ratio of 5% (reference silver nitrate weight) of the coating agent is dissolved in ethanol and added to the reaction solution. Stirring is continued for 15 minutes to complete the reaction, and then the material is placed in a solid-liquid separator and washed with ethanol. The coating content is washed to about 2%, and then it can be put into the oven.

[0057] The traditional reaction system equipment is simple, but due to the continuous decrease in the concentration of silver salt during the stirring and re-reaction process, the particle size of the powder is uncontrollable at the end of the reaction, and agglomeration and enlargement will occur; and as the amount of silver salt reaction increases, the liquid phase system in the reactor will increase. During the reaction of the solution, the final end reaction will be uncontrollable, making it impossible to scale up the reaction; the specific reaction time and results are shown in the following table:

[0058]

[0059] According to the characteristics of electronic probe products, the particle size of the powder is required to be stable and uniform to have better mixing performance, with a D50 range of 0.8-1.1μm and a D99 of <3μm. Compared with the traditional liquid phase method, the pipeline reactor of the present invention has the advantages of good stability and continuous production. From the reaction data, if it is a traditional reactor for feeding reaction mode, as the material input increases, the particle size will be unstable, and the overall reaction cannot be enlarged. After the material addition amount exceeds 15kg / batch, the reaction cannot be controlled. However, the pipeline reactor will not have such problems. The pipeline reactor is a continuous production. As time goes by, the particle size basically fluctuates slightly and will not fluctuate greatly. Therefore, the present invention selects a pipeline reactor for industrial production.

[0060] Example 3: Silver nitrate is the main raw material for this product. This example uses the correspondence between different concentrations of silver nitrate and the reaction particle size (the rest refers to the method of Example 1), and the detection instrument is Malvern laser particle size analyzer.

[0061]

[0062] From the perspective of reaction particle size, changes in silver nitrate concentration have a greater impact on the powder particle size, especially when the concentration exceeds 15%, D90 becomes seriously larger and agglomerates. The main reason is that the silver ion concentration is too high, which leads to intensified reaction and poor control of the overall reaction, resulting in abnormal particle morphology and particle size.

[0063] The invention discloses a method for preparing micron-sized silver chloride. The method does not adopt the existing reactor-type liquid phase reduction method, but adopts a pipeline reactor to accurately control the reaction time and temperature, including a process amplification study after mass production, and makes a detailed study on the temperature, concentration and stirring method. The method comprises the following steps: 1) dissolving a soluble silver salt in water in a certain proportion to form a solution A, wherein the pH value of the solution is controlled between 4 and 5; 2) adding a special dispersant to pure water in a certain proportion to form a solution B; 3) preparing a soluble chloride salt or hydrochloric acid in a certain proportion to form a solution C; 4) mixing a coating agent with alcohol or isopropanol in a certain proportion to form a solution D; 5) adding a complexing agent to solution A in a certain proportion to obtain a solution E, wherein the pH value of the solution E is controlled within a range of 9 to 10; 6) adding solution B to a receiving tube of a reactor and stirring is started, and the temperature is controlled at 20 to 25° C., and then adding the prepared solution E and solution C to a pipeline reactor at a fixed speed, wherein the angle of the pipeline reactor is controlled between 15 and 20°, and the length is selected according to the particle size, and the particle size can be adjusted as required. When the reaction is started, adding a certain proportion of solution D to the receiving tank; 7) washing the reaction solution with alcohol, centrifugal dehydration, vacuum drying and crushing the reaction solution to obtain a micron-grade silver chloride powder with a stable particle size. The preparation method of the invention adopts a pipeline reactor which is non-toxic, pollution-free, low-energy-consuming, easy to operate and capable of continuous production, and obtains micron-sized silver chloride powder with excellent dispersibility, which is suitable for silver chloride electronic probes and silver chloride alloy materials.

[0064] The technical content and technical solutions of the present invention have been fully demonstrated, and professionals familiar with the field may still make modifications and substitutions based on the parameters and reaction principles of the present invention without violating the present invention. Therefore, the present invention should not be limited to the specific implementation content of this application, but should include various modifications and substitutions that do not violate the invention and are covered by the claims of this patent application.

Claims

1. A method for preparing micron-level silver chloride for electronic probe, characterized in that: The following steps are involved: (1) mixing a complexing agent with a silver salt aqueous solution to prepare a solution E having a pH between 9 and 10; (2) mixing the dispersant with water to obtain solution B; (3) A soluble chloride salt or hydrochloric acid is added to water to obtain solution C; (4) mixing the coating agent and the solvent to obtain a solution D; (5) Through the pipeline reactor, solution E and solution C are simultaneously added dropwise to the reactor receiving tank containing solution B and solution D, and then coated to obtain micron-level silver chloride for electronic probe.

2. The method for preparing micron-level silver chloride for electronic probe according to claim 1, characterized in that: Solution B is stirred in the reactor receiving tank until bubbles appear on the surface, then solution D is added dropwise, stirring is maintained, and solution E and solution C are added dropwise through the pipeline reactor at the same time, followed by coating; after coating, the solution is centrifuged for dehydration, vacuum dried, and crushed to obtain micron-level silver chloride for electronic probes.

3. The method for preparing micron-level silver chloride for electronic probe according to claim 2, characterized in that: The stirring speed is controlled at 150-300 r / min; the dropping speed of solution E is 50-80 ml / min, and the dropping speed of solution C is 10-50 ml / min; the inclination angle of the pipeline reactor is 10°-20°.

4. The method for preparing micron-level silver chloride for electronic probe according to claim 1, characterized in that: The pH of the silver salt aqueous solution is controlled between 4 and 4.8; the silver salt can be silver nitrate and / or silver acetate; and the complexing agent can be disodium EDTA and / or ammonia water.

5. The method for preparing micron-level silver chloride for electronic probe according to claim 1, characterized in that: The dispersant is one or more of triethanolamine oleic acid soap, gelatin, polyvinyl pyrrolidone, polyvinyl alcohol, and Indek H8302; the use ratio of the dispersant is 3% to 6% of the weight of the silver salt.

6. The method for preparing micron-level silver chloride for electronic probe according to claim 1, characterized in that: The soluble chloride salt is sodium chloride and / or potassium chloride; the mass ratio of the chloride salt or hydrochloric acid to water is 1:10-15.

7. The method for preparing micron-level silver chloride for electronic probe according to claim 1, characterized in that: The coating agent is stearic acid or lauric acid, and the solvent is alcohol or isopropanol; the amount of the coating agent is 3% to 5% of the weight of the silver salt.

8. Micron-level silver chloride for electronic probe prepared by the method for preparing micron-level silver chloride for electronic probe according to claim 1.

9. An electronic probe or silver chloride alloy material, comprising the micron-level silver chloride for the electronic probe according to claim 8.

10. Use of the micron-level silver chloride for electronic probe according to claim 9 in the preparation of silver chloride electronic probe or silver chloride alloy material.

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