Preparation method of carbon black composite material for conductive paste

Abstract

The invention belongs to the field of conductive paste, and particularly relates to a preparation method of a carbon black composite material for conductive paste, which comprises the following steps: depositing metal on the surface of carbon black to be coated by adopting a vapor deposition mode to obtain the carbon black composite material with a metal coating layer. The carbon black composite material prepared by the method has good conductivity and stability, and the conductive paste prepared from the carbon black composite material can achieve a good conductive effect at room temperature.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of conductive paste, and particularly relates to a preparation method of a carbon black composite material for conductive paste. BACKGROUND

[0002] Conductive paste is a key material in the field of electronic information and is widely used in the fields of printed electronics, flexible electronics, semiconductor packaging, new energy photovoltaic cells and the like. However, traditional conductive paste (such as silver paste) needs high-temperature sintering to achieve good conductivity, which not only increases energy consumption but also limits its application on some high-temperature-resistant substrates. In addition, the conductivity and stability of traditional conductive paste need to be further improved. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a preparation method of a carbon black composite material for conductive paste. The carbon black composite material prepared by the method has good conductivity and stability, and the conductive paste made of the carbon black composite material can achieve good conductive effect at room temperature.

[0004] The present application provides a preparation method of a carbon black composite material for conductive paste, comprising the following steps:

[0005] The metal is deposited on the surface of the carbon black to be coated by gas phase deposition to obtain a carbon black composite material with a metal coating layer.

[0006] Preferably, the specific surface area of the carbon black to be coated is 100-1200 m 2 / g, and the average particle size is 10-100 nm.

[0007] Preferably, the carbon black to be coated is pretreated before gas phase deposition; the pretreatment method includes heating activation and / or ultrasonic cleaning.

[0008] Preferably, the pressure of the gas phase deposition is 0.001-1 Torr.

[0009] Preferably, the deposition rate of the gas phase deposition is 0.1-1 nm / min.

[0010] Preferably, the method of the gas phase deposition is physical vapor deposition or chemical vapor deposition.

[0011] Preferably, the method of the chemical vapor deposition is plasma-enhanced chemical vapor deposition.

[0012] Preferably, the metal coating layer is a nickel layer, a copper layer or a silver layer.

[0013] Preferably, the mass fraction of the metal coating layer in the carbon black composite material is 10-30%.

[0014] Preferably, the method further comprises the steps of washing and drying the obtained carbon black composite material.

[0015] Compared with the prior art, the present application provides a preparation method of a carbon black composite material for conductive paste, comprising the following steps: depositing a metal on the surface of the carbon black to be coated by using a gas phase deposition method, to obtain a carbon black composite material with a metal coating layer. The carbon black composite material prepared by the method of the present application has good conductivity and stability. The conductive paste made of the carbon black composite material can achieve good conductivity at room temperature. More specifically, the technical solution of the present application has at least the following advantages:

[0016] (1) Carbon black itself has high specific surface area and good conductivity, and when added to the paste, it can form a conductive network to improve the electrical conductivity. After the surface of the carbon black is coated with a metal layer, the high conductivity of the metal combines with the conductive network of the carbon black, further improving the overall conductivity of the conductive paste, so that it can achieve good conductivity at room temperature.

[0017] (2) Carbon black is chemically stable and is not prone to chemical reactions with other substances. It will not be affected by environmental changes and can maintain stable performance of the conductive paste for a long time. On this basis, the coating of the metal layer can reduce the performance fluctuations of the carbon black under the influence of environmental factors such as humidity and temperature changes, further improving the stability of the conductive paste and ensuring its stable conductivity under different conditions.

[0018] (3) Carbon black is more cost-effective than traditional conductive materials such as precious metals. Replacing part of the precious metal powder with carbon black can effectively reduce costs. The gas phase deposition method is relatively simple, which can reduce complex preparation steps and further reduce production costs, improve the performance-price ratio of the conductive paste, and make it competitive in more application fields.

[0019] (4) By controlling the process parameters of the gas phase deposition method, such as temperature, pressure, gas flow, etc., the thickness and uniformity of the metal layer can be accurately controlled, so as to optimize the performance of the conductive paste and meet the needs of different application scenarios. The process stability of the gas phase deposition method is high, and it is easy to realize large-scale production, ensuring the consistency of product quality.

[0020] (5) The composite structure of carbon black and metal can enhance the flexibility and adhesion of the conductive paste. The coating of the metal layer not only improves the connection strength between carbon black particles, but also makes the conductive paste form a more stable adhesion on the surface of the substrate, so that the conductive paste performs well in application scenarios that require certain mechanical strength and flexibility, such as flexible circuits and wearable devices, and is not easily affected by mechanical deformation. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0022] The present application provides a preparation method of carbon black composite material for conductive paste, comprising the following steps:

[0023] The metal is deposited on the surface of the carbon black to be coated by using the gas phase deposition method, so as to obtain the carbon black composite material with the metal coating layer.

[0024] In the preparation method provided by the present application, the specific surface area of the carbon black to be coated is preferably 100-1200 m 2 / g, and specifically can be 100 m 2 / g, 200 m 2 / g, 250 m 2 / g, 260 m 2 / g, 300 m 2 / g, 400 m 2 / g, 500 m 2 / g, 600 m 2 / g, 700 m 2 / g, 800 m 2 / g, 900 m 2 / g, 1000 m 2 / g, 1100 m 2 / g or 1200 m 2 / g; and the average particle size of the carbon black to be coated is preferably 10-100 nm, and specifically can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm or 100 nm.

[0025] In the preparation method provided by the present application, the carbon black to be coated is preferably pretreated before the gas phase deposition; and the pretreatment method preferably comprises heating activation and / or ultrasonic cleaning.

[0026] In the preparation method provided by the present application, the heating activation is preferably performed in an oxygen-containing atmosphere; the oxygen-containing atmosphere is preferably air; the temperature of the heating activation is preferably 200-400℃, and specifically can be 200℃, 250℃, 300℃, 350℃ or 400℃; and the time of the heating activation is preferably 1-5 h, and specifically can be 1 h, 2 h, 3 h, 4 h or 5 h.

[0027] In the preparation method provided by the application, the medium for ultrasonic cleaning is preferably carried out in ethanol and / or water; preferably, a dispersing agent is added to the water; the dispersing agent is preferably sodium dodecyl benzene sulfonate (SDBS); the content of the dispersing agent in the ultrasonic medium is preferably 0.05-0.2 wt%, and can be specifically 0.05 wt%, 0.1 wt%, 0.15 wt% or 0.2 wt%; the power of ultrasonic cleaning is preferably 100-500 W, and can be specifically 100 W, 200 W, 300 W, 400 W or 500 W; the frequency of ultrasonic cleaning is preferably 20-50 kHz, and can be specifically 20 kHz, 28 kHz, 30 kHz, 40 kHz or 50 kHz; the time of ultrasonic cleaning is preferably 0.5-2 h, and can be specifically 0.5 h, 1 h, 1.5 h or 2 h; after the ultrasonic cleaning is completed, the cleaned carbon black is dried; the drying method is preferably vacuum drying; the drying temperature is preferably 50-200 DEG C, and can be specifically 50 DEG C, 60 DEG C, 100 DEG C, 150 DEG C or 200 DEG C; the drying time is preferably 6-48 h, and can be specifically 6 h, 12 h, 24 h, 36 h or 48 h.

[0028] In the preparation method provided by the application, the temperature of gas phase deposition is preferably 10-800 DEG C, and can be specifically 10 DEG C, 15 DEG C, 20 DEG C, 25 DEG C, 30 DEG C, 35 DEG C, 40 DEG C, 50 DEG C, 70 DEG C, 100 DEG C, 120 DEG C, 150 DEG C, 200 DEG C, 250 DEG C, 300 DEG C, 400 DEG C, 500 DEG C, 600 DEG C, 700 DEG C or 800 DEG C. In the application, the deposition temperature is preferably accurately controlled according to the characteristics of different metals and carbon black, and selecting a suitable deposition temperature can make the metal atoms have suitable migration activity, and a more uniform and continuous coating layer can be formed.

[0029] In the preparation method provided by the application, the pressure of gas phase deposition is preferably 0.001-1 Torr, and can be specifically 0.001 Torr, 0.003 Torr, 0.005 Torr, 0.007 Torr, 0.01 Torr, 0.03 Torr, 0.05 Torr, 0.07 Torr, 0.1 Torr, 0.3 Torr, 0.5 Torr, 0.7 Torr or 1 Torr. In the application, in this pressure range, the average free path of gas molecules increases, and the freedom of movement is significantly improved, which can more efficiently contact and react with the surface of carbon black, reduce unnecessary collision loss in the gas phase, and improve the deposition efficiency and quality.

[0030] In the preparation method provided by the application, the flow rates of the metal source vapor, the carrier gas (argon, nitrogen, etc.) and the reaction gas (oxygen, hydrogen, etc.) in the vapor deposition process are preferably strictly controlled. The flow rate of the carrier gas is preferably controlled at 10-1000 sccm, which is used to stably transport the metal source vapor to the deposition area; the flow rate of the reaction gas is adjusted according to the specific chemical reaction, which directly affects the metal deposition rate and the quality of the coating layer, and the optimal value needs to be determined through experiments.

[0031] In the preparation method provided by the application, the deposition rate of the vapor deposition is preferably 0.1-1 nm / min, and can be 0.1 nm / min, 0.2 nm / min, 0.3 nm / min, 0.4 nm / min, 0.5 nm / min, 0.6 nm / min, 0.7 nm / min, 0.8 nm / min, 0.9 nm / min or 1 nm / min.

[0032] In the preparation method provided by the application, the vapor deposition is preferably physical vapor deposition (PVD) or chemical vapor deposition (CVD). The physical vapor deposition is to convert the metal source substance into atomic or ionic state by high-temperature evaporation or electric field sputtering, and the metal particles are deposited onto the carbon black surface in a straight line motion in a vacuum environment to form a metal coating layer. This method has the characteristics of fast deposition rate and high purity of the film layer. The chemical vapor deposition is to introduce a gaseous precursor containing metal elements into a reaction chamber, and the gaseous precursor is decomposed to form a metal coating layer under the conditions of high temperature, catalyst, etc. This method can realize accurate control of the composition and structure of the metal layer. In the application, the chemical vapor deposition is preferably plasma-enhanced chemical vapor deposition (PECVD).

[0033] In the preparation method provided by the application, the product is cooled after the vapor deposition. In the application, the cooling method should be selected according to the actual needs. Natural cooling is suitable for scenes with low cooling rate requirements; air cooling or water cooling can realize rapid cooling, effectively inhibit the oxidation and agglomeration of the metal on the carbon black surface, and ensure the stability and integrity of the coating layer.

[0034] In the preparation method provided by the application, the product is preferably cleaned and dried after cooling. The cleaning is preferably carried out in multiple steps using organic solvents (such as ethanol, acetone) combined with ultrapure water to completely remove the residual impurities, unreacted precursors and by-products on the surface of the product; the drying is preferably vacuum drying or oven drying; the water content of the dried product is preferably reduced to below 0.5%.

[0035] In the preparation method provided by the application, the metal coating layer is preferably a nickel layer, a copper layer or a silver layer.

[0036] In the preparation method provided by the present application, the mass ratio of the metal coating layer in the carbon black composite material is preferably 10-30%, and can be specifically 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%.

[0037] In some embodiments provided by the present application, the carbon black composite material coated with a nickel layer is preferably prepared by a chemical vapor deposition method, and the specific preparation steps include:

[0038] a) heating and activating the carbon black to be coated in an air atmosphere, and cooling to obtain activated carbon black;

[0039] b) placing a nickel precursor in a heating jacket at the gas inlet end of a tube furnace, placing the activated carbon black in the constant temperature zone at the center of the tube furnace, sealing the tube furnace and vacuumizing, and then introducing inert gas into the tube furnace through the gas inlet end for purging;

[0040] c) continuously introducing inert gas into the tube furnace through the gas inlet end, and heating the tube furnace to a reaction temperature; then switching the gas introduced into the tube furnace to reducing gas and maintaining for a period of time;

[0041] d) opening the heating jacket to vaporize the nickel precursor, while adjusting the gas introduced into the tube furnace to a mixed gas of inert gas and reducing gas, and the vaporized nickel precursor enters the tube furnace along with the mixed gas and is reduced and deposited on the surface of the carbon black;

[0042] e) after deposition, closing the heating jacket, and cooling the product to room temperature in the presence of reducing gas.

[0043] In the preparation method of the carbon black composite material coated with a nickel layer provided by the present application, in step a), the heating and activation is preferably heated at a rate of 1-10°C / min, and can be specifically 5°C / min; the terminal temperature of the heating and activation is preferably 200-400°C, and can be specifically 300°C; and the holding time of the heating and activation is preferably 1-3h, and can be specifically 2h.

[0044] In the preparation method of the carbon black composite material coated with a nickel layer provided by the present application, in step b), the nickel precursor is preferably nickelocene; and the inert gas is preferably argon.

[0045] In the preparation method of the nickel-coated carbon black composite material provided in the present application, in step c), the heating rate for heating to the reaction temperature is preferably 5-20°C / min, and specifically can be 10°C / min; the reaction temperature is preferably 500-700°C, and specifically can be 600°C; the reducing gas is preferably hydrogen; and the holding time is preferably 10-60 min, and specifically can be 30 min.

[0046] In the preparation method of the nickel-coated carbon black composite material provided in the present application, in step d), the heating temperature of the heating jacket is preferably 120-180°C, and specifically can be 150°C; the vapor pressure of the nickel precursor after vaporization is preferably 0.8-1 Torr; the inlet flow rate of the mixed gas is preferably 80-150 sccm, and specifically can be 100 sccm; the inlet volume flow ratio of the inert gas to the reducing gas in the mixed gas is preferably 1:(0.5-2), and specifically can be 1:1; and the reducing deposition time is preferably 0.5-2 h, and specifically can be 1 h.

[0047] In the preparation method of the nickel-coated carbon black composite material provided in the present application, in step e), the cooling rate is preferably 10-20°C / min, and specifically can be 15°C / min.

[0048] In some embodiments provided in the present application, the copper-coated carbon black composite material is preferably prepared by physical vapor deposition, and the specific preparation steps include:

[0049] a) dispersing the carbon black to be coated in anhydrous ethanol, ultrasonic treatment, solid-liquid separation, and drying to obtain treated carbon black;

[0050] b) installing a copper target in a magnetron sputtering chamber, and after vacuumizing the magnetron sputtering chamber, introducing an inert gas to pre-sputter and clean the target surface at a certain power;

[0051] c) laying the treated carbon black on a copper foil substrate, and then placing it on the sample stage of the magnetron sputtering chamber, and then vacuumizing and performing Ar plasma cleaning;

[0052] d) adjusting the inert gas flow rate in the magnetron sputtering chamber and the chamber pressure, and performing magnetron sputtering to deposit copper on the surface of the carbon black at a certain power;

[0053] e) after the deposition is completed, the product is cooled to room temperature in the presence of an inert gas; and then washed and dried.

[0054] In the preparation method of the copper-coated carbon black composite material provided by the application, in step a), the adding amount of the carbon black to be coated in anhydrous ethanol is preferably 5-20 g / L, and specifically can be 10 g / L; the power of the ultrasonic treatment is preferably 100-300 W, and specifically can be 200 W; the frequency of the ultrasonic treatment is preferably 20-60 kHz, and specifically can be 40 kHz; the time of the ultrasonic treatment is preferably 0.5-2 h, and specifically can be 1 h; the drying mode is preferably vacuum drying; the drying temperature is preferably 100-200 ℃, and specifically can be 150 ℃; the drying pressure is preferably 0.5*10 -3 -5*10 - 3 Torr, and specifically can be 10 -3 Torr; and the drying time is preferably 6-24 h, and specifically can be 12 h.

[0055] In the preparation method of the copper-coated carbon black composite material provided by the application, in step b), the vacuum extraction is preferably to 1*10 -7 -10*10 -7 Torr, and specifically can be 5*10 -7 Torr; the inert gas is preferably argon; the power of the pre-sputtering is preferably 200-400 W, and specifically can be 300 W; and the time of the pre-sputtering is preferably 2-10 min, and specifically can be 5 min.

[0056] In the preparation method of the copper-coated carbon black composite material provided by the application, in step c), the vacuum extraction is preferably to 0.5*10 -6 -5*10 -6 Torr, and specifically can be 1*10 -6 Torr; the power of the Ar plasma cleaning is preferably 40-60 W, and specifically can be 50 W; the pressure of the Ar plasma cleaning is preferably 2-8 mTorr, and specifically can be 5 mTorr; and the time of the Ar plasma cleaning is preferably 2-10 min, and specifically can be 5 min.

[0057] In the preparation method of the copper-coated carbon black composite material provided by the application, in step d), the inert gas is preferably argon; the inert gas flow is preferably 10-50 sccm, and specifically can be 20 sccm; the chamber pressure is preferably 1-5 mTorr, and specifically can be 3 mTorr; the power of the magnetron sputtering is preferably 50-200 W, and specifically can be 100 W; the sample table rotation speed during the magnetron sputtering is preferably 2-10 rpm, and specifically can be 5 rpm; and the deposition time is preferably 10-60 min, and specifically can be 30 min.

[0058] In the preparation method of the copper-coated carbon black composite material provided in the present application, in step e), the washing method is preferably alcohol washing; the drying method is preferably vacuum drying; and the drying temperature is preferably 40-80°C, and specifically 60°C.

[0059] In some embodiments provided in the present application, the silver-coated carbon black composite material is preferably prepared by plasma-enhanced chemical vapor deposition, and the specific preparation steps include:

[0060] a) dispersing the carbon black to be coated in water added with a dispersing agent, ultrasonic treatment, solid-liquid separation, and drying to obtain treated carbon black;

[0061] b) placing a silver precursor in a vaporization device connected to a deposition chamber, placing the treated carbon black in the deposition chamber, and then vacuumizing the deposition chamber;

[0062] c) introducing inert gas and reducing gas into the deposition chamber, and starting a radio frequency power source to generate plasma to treat the carbon black for a period of time;

[0063] d) continuously introducing inert gas and reducing gas into the deposition chamber, and introducing the vaporized silver precursor into the deposition chamber; under the assistance of plasma, the silver precursor is reduced and deposited on the surface of the carbon black;

[0064] e) after the deposition is completed, the product is cooled to room temperature in the presence of inert gas; and then washed and dried.

[0065] In the preparation method of the silver-coated carbon black composite material provided in the present application, in step a), the addition amount of the carbon black to be coated in water is preferably 2-10 g / L, and specifically 5 g / L; the power of the ultrasonic treatment is preferably 200-500 W, and specifically 300 W; the frequency of the ultrasonic treatment is preferably 20-40 kHz, and specifically 28 kHz; the time of the ultrasonic treatment is preferably 0.5-2 h, and specifically 1 h; the drying method is preferably vacuum drying; the drying temperature is preferably 40-80°C, and specifically 60°C; and the drying time is preferably 12-48 h, and specifically 24 h.

[0066] In the preparation method of the silver-coated carbon black composite material provided in the present application, in step b), the silver precursor is preferably silver hexafluoroacetylacetone; and the vacuumization is preferably to 0.5×10 -3 -5×10 -3 Torr, and specifically 10 - 3 Torr.

[0067] In the preparation method of the silver-coated carbon black composite material provided by the application, in step c), the inert gas is preferably argon; the reducing gas is preferably hydrogen; the volume flow ratio of the inert gas to the reducing gas is preferably (2-6):1, and specifically can be 4:1; the power of the radio frequency power source is preferably 20-80 W, and specifically can be 50 W; the plasma treatment time is preferably 2-10 min, and specifically can be 5 min.

[0068] In the preparation method of the silver-coated carbon black composite material provided by the application, in step d), the inert gas is preferably argon; the reducing gas is preferably hydrogen; the volume flow ratio of the inert gas to the reducing gas is preferably (1-5):2, and specifically can be 3:2; the deposition chamber pressure during the reduction deposition process is preferably 70-150 mTorr, and specifically can be 100 mTorr; the radio frequency power source power during the reduction deposition process is preferably 20-80 W, and specifically can be 50 W; the deposition chamber temperature during the reduction deposition process is preferably 100-200 DEG C, and specifically can be 150 DEG C; the reduction deposition time is preferably 30-60 min, and specifically can be 45 min.

[0069] In the preparation method of the silver-coated carbon black composite material provided by the application, in step e), the washing mode is preferably alcohol washing; the drying mode is preferably vacuum drying; the drying temperature is preferably 60-100 DEG C, and specifically can be 80 DEG C; the drying time is preferably 4-8 h, and specifically can be 6 h.

[0070] The carbon black composite material prepared by the method has good conductivity and stability, and the conductive paste made of the carbon black composite material can achieve good conductivity at room temperature. More specifically, the technical scheme of the application has at least the following advantages:

[0071] (1) Carbon black itself has high specific surface area and good conductivity, and can form a conductive network when added to the paste, thereby improving the electrical conductivity; after the surface of the carbon black is coated with metal, the high conductivity of the metal and the conductive network of the carbon black are combined, thereby further improving the overall conductivity of the conductive paste, so that the conductive paste can achieve good conductivity at room temperature.

[0072] (2) Carbon black is chemically stable and is not prone to chemical reaction with other substances, and will not be affected by environmental changes, so that the conductivity of the conductive paste can be kept stable for a long time; on this basis, the coating of the metal layer can reduce the performance fluctuation of the carbon black under the influence of environmental factors (such as humidity and temperature change), thereby further improving the stability of the conductive paste and ensuring that the conductive paste can maintain stable conductivity under different conditions.

[0073] (3) Carbon black is more cost-effective than traditional conductive materials such as precious metals. Replacing part of the precious metal powder with carbon black can effectively reduce costs. The vapor deposition method is relatively simple, which can reduce complex preparation steps, further reduce production costs, and improve the performance-price ratio of conductive paste, making it competitive in more application fields.

[0074] (4) By controlling the process parameters of the vapor deposition method, such as temperature, pressure, gas flow, etc., the thickness and uniformity of the metal layer can be accurately controlled, thereby optimizing the performance of the conductive paste to meet the needs of different application scenarios. The process stability of the vapor deposition method is high, easy to realize large-scale production, and ensure the consistency of product quality.

[0075] (5) The composite structure of carbon black and metal can enhance the flexibility and adhesion of the conductive paste. The wrapping of the metal layer not only improves the connection strength between carbon black particles, but also makes the conductive paste form a more secure adhesion on the substrate surface, thereby making the conductive paste perform well in application scenarios that require certain mechanical strength and flexibility, such as flexible circuits and wearable devices, and not easily affected by mechanical deformation.

[0076] For a clearer understanding, the following examples are described in detail below.

[0077] Example 1

[0078] Chemical vapor deposition (CVD) method was used to prepare nickel-coated carbon black composite material, as follows:

[0079] 1. Materials and equipment:

[0080] Carbon black: Vulcan XC-72R (specific surface area 254 m 2 / g, average particle size 30-50 nm);

[0081] Precursor: Nickelocene (Ni(C5H5)2, purity 99.9%);

[0082] Gas source:

[0083] Hydrogen (H2, purity 99.999%) as carrier gas and reducing agent;

[0084] Argon (Ar, purity 99.999%) as carrier gas and protective gas;

[0085] Equipment:

[0086] Horizontal tube furnace (Thermo Scientific, maximum temperature 1200℃);

[0087] Quartz tube (inner diameter 50 mm, length 1200 mm);

[0088] Heating jacket (for precursor vaporization, temperature range 20-200℃).

[0089] 2. Detailed steps:

[0090] (1) Carbon black pretreatment:

[0091] Put 5 g of carbon black in a ceramic boat and place it in a tube furnace; introduce air (flow rate 200 sccm) and heat to 300℃ at a rate of 5℃ / min, and keep the temperature for 2 hours; naturally cool to room temperature to obtain activated carbon black with oxygen-containing groups (-OH, -COOH) on the surface.

[0092] (2) Build the deposition system:

[0093] Put 2 g of nickelocene in a quartz boat and place it in the heating jacket at the gas inlet end of the tube furnace; place 0.5 g of pretreated carbon black flat in another quartz boat in the constant temperature zone of the tube furnace; seal the system, vacuumize to 10 -2 Torr, and then introduce Ar (300 sccm) to purge for 15 minutes.

[0094] (3) Nickel deposition process:

[0095] ① Heating stage:

[0096] Keep the Ar flow rate at 100 sccm and heat to 600℃ at a rate of 10℃ / min; switch to H2 (100 sccm) and keep it for 30 minutes to reduce the surface of the carbon black.

[0097] ② Deposition stage:

[0098] Turn on the precursor heating jacket to 150℃ (nickelocene vapor pressure is about 1 Torr); adjust the H2 flow rate to 50 sccm and the Ar flow rate to 50 sccm (total flow rate 100 sccm); keep the temperature at 600℃ for 1 hour, and the nickel precursor decomposes and deposits: Ni(C5H5)2→ Ni + 2C5H5 (gas phase cracking).

[0099] ③ Cooling stage:

[0100] Turn off the precursor heating and keep the H2 flow rate, and cool to room temperature at a rate of 15℃ / min; switch back to Ar (200 sccm) protection, and take out the sample.

[0101] Example 2

[0102] Copper-coated carbon black composite material was prepared by physical vapor deposition (PVD) as follows:

[0103] 1. Materials and equipment:

[0104] Carbon black: Ketjenblack EC-300J (specific surface area 800 m 2 / g, average particle size 50-80 nm);

[0105] Target: Copper target (purity 99.99%, diameter 76.2 mm, thickness 6 mm);

[0106] Gas source: Argon (Ar, purity 99.999%) as carrier gas and plasma working gas;

[0107] Equipment:

[0108] Magnetron sputtering system (Kurt J. Lesker PVD75);

[0109] Radio frequency power supply (RF 13.56 MHz, 1000 W);

[0110] Rotary sample stage (0-30 rpm).

[0111] 2. Detailed steps:

[0112] (1) Carbon black pretreatment:

[0113] Disperse carbon black in anhydrous ethanol (10 g / L), ultrasonic treatment (power 200 W, frequency 40 kHz) for 1 hour, vacuum filtration, collect the filter cake, and dry in a vacuum drying box (150°C, 10 -3 Torr) for 12 hours.

[0114] (2) Target installation and chamber cleaning:

[0115] Install the copper target, adjust the target-substrate distance to 10 cm; vacuum the chamber to 5x10 -7 Torr, introduce Ar (100 sccm), and pre-sputter the target surface for 5 minutes at a power of 300 W to clean the target surface.

[0116] (3) Copper deposition process:

[0117] ① Sample loading and pretreatment:

[0118] Uniformly lay 0.2 g of pretreated carbon black on the copper foil substrate and place it in the sample stage; vacuum to 1x10 -6 Torr, and clean with Ar plasma (power 50 W, pressure 5 mTorr, 5 minutes).

[0119] ② Sputter deposition:

[0120] Adjust the Ar flow to 20 sccm and the working pressure to 3 mTorr; turn on the RF power supply (power 100 W) and rotate the sample stage at 5 rpm; deposit for 30 minutes at a deposition rate of about 0.5 nm / min.

[0121] ③ Post-treatment:

[0122] The power was turned off, the Ar purge was maintained, and the sample was allowed to cool to room temperature. The sample was removed, dispersed in absolute ethanol by sonication, centrifuged, and dried under vacuum at 60 °C.

[0123] Example 3

[0124] Silver-coated carbon black composites were prepared by plasma-enhanced chemical vapor deposition (PECVD) as follows:

[0125] 1. Materials and equipment:

[0126] Carbon black: Printex XE2-B (specific surface area 1000 m 2 / g, average particle size 20-40 nm);

[0127] Precursor: silver hexafluoroacetylacetonate (Ag(hfac), purity 99.9%);

[0128] Gas sources:

[0129] Argon (Ar, purity 99.999%) as carrier and plasma working gas;

[0130] Hydrogen (H2, purity 99.999%) as reducing agent;

[0131] Equipment:

[0132] Parallel-plate PECVD system (Plasma-Therm 790);

[0133] RF power source (13.56 MHz, 500 W);

[0134] Heating stage (room temperature - 300 °C, accuracy ± 5 °C);

[0135] Bubble (for precursor vaporization).

[0136] 2. Detailed procedure:

[0137] (1) Carbon black pretreatment:

[0138] The carbon black was dispersed in deionized water (5 g / L) with 0.1 wt% sodium dodecylbenzenesulfonate (SDBS) as dispersant, sonicated (power 300 W, frequency 28 kHz) for 1 h, centrifuged, and dried under vacuum at 60 °C for 24 h.

[0139] (2) Deposition system preparation:

[0140] The Ag(hfac) was placed in the bubbler and heated to 120 °C (vapor pressure ~ 5 Torr); 0.3 g of pretreated carbon black was loaded onto the sample stage, and the chamber was evacuated to 10 -3 Torr.

[0141] (3) Silver deposition process:

[0142] ① Plasma pretreatment:

[0143] Introduce Ar (80 sccm) and H2 (20 sccm) with total pressure of 100 mTorr; turn on RF power (power 50 W) to generate plasma for 5 minutes.

[0144] ② Silver deposition:

[0145] Adjust the flow rate of Ar carrier gas to 30 sccm, keep the flow rate of H2 unchanged, and the bubbler pressure at 500 mTorr; keep the total pressure at 100 mTorr, RF power at 50 W, and the temperature at 150℃; deposit for 45 minutes, and the reaction mechanism is Ag (hfac) + H2→ Ag↓+ hfacH (plasma assisted reduction).

[0146] ③ Post-treatment:

[0147] Turn off the precursor heating and RF power, continue to introduce Ar (100 sccm) to cool to room temperature; collect the sample, wash with anhydrous ethanol for 3 times, and vacuum dry at 80℃ for 6 hours.

[0148] Comprehensive evaluation

[0149] The key condition parameters and product resistivity test results of examples 1-3 are summarized in the following table:

[0150]

[0151]

[0152] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for producing a carbon black composite material for conductive paste, characterized by, The method comprises the following steps: The metal is deposited on the surface of the carbon black to be coated by gas deposition to obtain a carbon black composite material with a metal coating layer.

2. The production method according to claim 1, characterized by, The specific surface area of the carbon black to be coated is 100-1200 m 2 / g, and the average particle size is 10-100 nm.

3. The preparation method according to claim 1, characterized in that, The carbon black to be coated is pretreated before gas deposition; the pretreatment method comprises heating activation and / or ultrasonic cleaning.

4. The method of claim 1, wherein, The pressure of the gas deposition is 0.001-1 Torr.

5. The preparation method according to claim 1, characterized in that, The deposition rate of the gas deposition is 0.1-1 nm / min.

6. The method of claim 1, wherein, The gas deposition method is physical vapor deposition or chemical vapor deposition.

7. The production method according to claim 6, wherein The chemical vapor deposition method is plasma-enhanced chemical vapor deposition.

8. The method of claim 1, wherein, The metal coating layer is a nickel layer, a copper layer or a silver layer.

9. The method of claim 1, wherein, The mass ratio of the metal coating layer in the carbon black composite material is 10-30%.

10. The method of claim 1, wherein, The method further comprises the following steps: The obtained carbon black composite material is washed and dried.

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