Production process for improving conductivity of carbon black

Abstract

The invention relates to the technical field of carbon black, in particular to a production process for improving conductivity of carbon black, which comprises the following steps: activating carbon black with carbon dioxide, then treating with nitric acid to obtain a porous carbon black material, treating the porous carbon black material with a mixed amino acid solution to obtain a carbon black material loaded with a mixed amino acid adsorption layer; then adding a silver nitrate solution, stirring and mixing, dropwise adding a sodium borohydride solution, controlling the reaction temperature and pH, and filtering, washing and drying after the reaction is finished, so as to obtain a high-conductivity carbon black product. By adopting the production process, the conductivity of the carbon black can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon black, in particular to a production process for improving the conductivity of carbon black. Background Art

[0002] Carbon black, a form of amorphous carbon, possesses diverse properties, including dispersion, adsorption, and conductivity. Due to these diverse properties, it is widely used in a variety of fields, including environmental protection, chemical engineering, food and medicine. In the battery and energy sectors, carbon black is often used as an additive to improve the conductivity of electrode materials. However, existing carbon black exhibits poor conductivity, which impacts the performance of batteries or electrode materials. Therefore, it is necessary to develop a production process to improve carbon black conductivity. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a production process for improving the conductivity of carbon black is provided, and a carbon black product with higher conductivity can be obtained by utilizing the production process.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: A production process for improving the conductivity of carbon black, the production process comprising the following steps: (1) Take carbon black, introduce nitrogen into it for preheating, then introduce carbon dioxide into it for activation, and after the activation is completed, introduce nitrogen into it again to cool it to room temperature, wash it, and dry it to obtain the pore-forming carbon black material for use; (2) taking the carbon black material after pore formation described in step (1), adding nitric acid and heating and stirring, washing to neutrality after the reaction, filtering, and drying the obtained porous carbon black material for use; (3) Take the porous carbon black material described in step (2), add the mixed amino acid solution, adjust the pH, heat, ultrasonically disperse, filter, and dry to obtain a carbon black material loaded with a mixed amino acid adsorption layer for later use; (4) Take the carbon black material loaded with the mixed amino acid adsorption layer in step (3), add deionized water and stir, add silver nitrate solution to the obtained carbon black liquid, stir and mix, then add sodium borohydride solution dropwise and continue stirring, control the pH and reaction temperature, filter, wash and dry after the reaction is completed, and then obtain a highly conductive carbon black product.

[0005] As an improved technical solution, during the preheating treatment in step (1), the carbon black material is heated to 300-450°C at a heating rate of 5-10°C / min.

[0006] As an improved technical solution, the flow rate of carbon dioxide during the activation treatment in step (1) is 20-60 mL / min, the temperature of the activation treatment is controlled to be 700-900° C., and the time of the activation treatment is controlled to be 1-2 h.

[0007] As an improved technical solution, the pore-forming carbon black material in step (2) is mixed with the nitric acid in a mass ratio of 1:4-8, and the concentration of the nitric acid is 40-50wt%.

[0008] As an improved technical solution, in step (2), the temperature is heated to 100-120°C and the reaction time is controlled to be 2-4 hours.

[0009] As an improved technical solution, the porous carbon black material in step (3) is mixed with the mixed amino acid solution in a mass-to-volume ratio of 1:1.2-1.8; the mixed amino acid solution is a solution formed by mixing lysine, phenylalanine and purified water in a mass-to-volume ratio of 2-4 mg:1-3 mg:5-15 mL.

[0010] As an improved technical solution, in step (3), the pH is adjusted to 7-8, the mixture is heated to 50-70°C, the power of ultrasonic dispersion is 400-500w, and the time of ultrasonic dispersion is 15-35min.

[0011] As an improved technical solution, the carbon black material loaded with the mixed amino acid adsorption layer in step (4) is mixed with the deionized water in a mass-to-volume ratio of 1:1.2-1.5.

[0012] As an improved technical solution, the mass ratio of the carbon black material loaded with the mixed amino acid adsorption layer in step (4) to the silver nitrate in the silver nitrate solution is 2-3.2:1, and the concentration of the silver nitrate solution and the concentration of the sodium borohydride are both 0.08-0.18 mol / L.

[0013] As an improved technical solution, in step (4), the pH is controlled at 8-10 and the reaction temperature is controlled at 25-45°C.

[0014] After adopting the above technical solution, the beneficial effects of the present invention are: The present invention first activates carbon black with carbon dioxide to form abundant micropores and mesopores inside the carbon black particles, significantly increasing their specific surface area and porosity, providing more active sites and space for the introduction of functional groups, amino acid adsorption and metal particle loading in subsequent steps; then it is oxidized with nitric acid to introduce oxygen-containing functional groups such as carboxyl (-COOH), hydroxyl (-OH), and carbonyl (C=O), thereby increasing the hydrophilicity and chemical activity of the carbon black surface and enhancing its interaction with subsequent amino acid solutions and metal ions. A mixed amino acid adsorption layer is then constructed, which can, on the one hand, increase the dispersibility of carbon black in aqueous solution and avoid particle agglomeration; on the other hand, the amino (-NH2) and carboxyl (-COOH) functional groups in the amino acid molecules can serve as coordination groups to react with silver ions (Ag) in subsequent steps. + ) to coordinate, thus increasing the adsorption amount and binding stability of silver ions on the carbon black surface; then by controlling the reaction conditions, silver nitrate provides Ag + Sodium borohydride (NaBH4) is used as a strong reducing agent to reduce Ag + Reduced to metallic silver (Ag) nanoparticles; the amino acid adsorption layer on the carbon black surface captures Ag through coordination + , so that silver nanoparticles are evenly loaded on the surface and pores of carbon black. Since the loaded silver nanoparticles can form a conductive path between carbon black particles, the contact resistance of carbon black is reduced and the overall conductive performance is significantly improved. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Example 1

[0016] A production process for improving the conductivity of carbon black comprises the following steps: (1) Take 100 mg of carbon black with a particle size of 30-40 nm (specific surface area of ​​80-130 m 2 / g), firstly introduce nitrogen for preheating treatment (heat the carbon black material to 300℃ at a heating rate of 5℃ / min), then introduce carbon dioxide at a flow rate of 20mL / min for activation treatment (the activation temperature is 700℃ and the activation time is 1h), introduce nitrogen again to cool to room temperature, wash with deionized water, and dry to obtain 94.2mg of carbon black material after pore formation (specific surface area of ​​500-800m 2 / g) standby; (2) Take 94.2 mg of the carbon black material after pore formation in step (1), add 40 wt% nitric acid in a mass ratio of 1:4, stir and heat to 100 ° C for reflux treatment, react for 2 hours, wash to neutrality, filter and dry to obtain 88.8 mg of porous carbon black material (specific surface area of ​​800-1000m 2 / g) standby; (3) Take 88.8 mg of the porous carbon black material in step (2), add a mixed amino acid solution (a solution prepared by mixing lysine, phenylalanine and purified water in a mass volume ratio of 2 mg:1 mg:5 mL) in a mass volume ratio of 1:1.2 (mg / ml), adjust the pH to 7, heat to 50°C, and ultrasonically disperse (ultrasonic dispersion power is 400 w, ultrasonic dispersion time is 15 min), rinse, filter, and dry to obtain 112.3 mg of carbon black material loaded with a mixed amino acid adsorption layer for use; (4) Take 112.3 mg of the carbon black material loaded with the mixed amino acid adsorption layer in step (3), add deionized water in a mass-to-volume ratio of 1:1.2 (mg / ml), add 0.08 mol / L silver nitrate solution to the carbon black liquid after stirring and mixing (the mass ratio of the carbon black material to the silver nitrate in the silver nitrate solution is 3.2:1), and then add 0.08 mol / L sodium borohydride solution and continue stirring. Control the reaction pH to 8 and the reaction temperature to 25°C. After the reaction is completed, filter, wash, and dry to obtain 134.6 mg of a highly conductive carbon black product. Example 2

[0017] A production process for improving the conductivity of carbon black comprises the following steps: (1) Take 100 mg of carbon black with a particle size of 30-40 nm (specific surface area of ​​80-130 m 2 / g), firstly introduce nitrogen for preheating treatment (heat the carbon black material to 350℃ at a heating rate of 6.5℃ / min), then introduce carbon dioxide at a flow rate of 30mL / min for activation treatment (the activation temperature is 750℃ and the activation time is 1.2h), introduce nitrogen again to cool to room temperature, wash with deionized water, and dry to obtain 93.1mg of carbon black material after pore formation (specific surface area of ​​600-900m 2 / g) standby; (2) Take 93.1 mg of the carbon black material after pore formation in step (1), add 42 wt% nitric acid in a mass ratio of 1:5, stir and heat to 105 ° C for reflux treatment, react for 2.5 hours, wash to neutrality, filter and dry to obtain 85.8 mg of porous carbon black material (specific surface area of ​​900-1300m 2 / g) standby; (3) Take 85.8 mg of the porous carbon black material in step (2), add a mixed amino acid solution (a solution prepared by mixing lysine, phenylalanine and purified water in a mass volume ratio of 2.5 mg:1.5 mg:8 mL) in a mass ratio of 1:1.5 (mg / ml), adjust the pH to 7.2, heat to 55°C, and perform ultrasonic dispersion treatment (ultrasonic dispersion power is 420 W, ultrasonic dispersion time is 20 min), rinse, filter, and dry to obtain 112.5 mg of carbon black material loaded with a mixed amino acid adsorption layer for use; (4) Take 112.5 mg of the carbon black material loaded with the mixed amino acid adsorption layer in step (3), add deionized water in a mass-to-volume ratio of 1:1.3 (mg / ml), stir and mix, then add 0.1 mol / L silver nitrate solution (the mass ratio of the carbon black material to the silver nitrate in the silver nitrate solution is 3:1), stir and mix, then add dropwise 0.1 mol / L sodium borohydride solution, control the reaction pH to 8.5, the reaction temperature to 30°C, filter, wash and dry after the reaction is completed, and then obtain 136.2 mg of a highly conductive carbon black product. Example 3

[0018] A production process for improving the conductivity of carbon black comprises the following steps: (1) Take 100 mg of carbon black with a particle size of 30-40 nm (specific surface area of ​​80-130 m 2 / g), firstly introduce nitrogen for preheating treatment (heat the carbon black material to 400℃ at a heating rate of 7.5℃ / min), then introduce carbon dioxide at a flow rate of 40mL / min for activation treatment (the activation temperature is 800℃ and the activation time is 1.5h), introduce nitrogen again to cool to room temperature, wash with deionized water, and dry to obtain 92.5mg of carbon black material after pore formation (specific surface area is 800-1100m 2 / g) standby; (2) Take 92.5 mg of the carbon black material after pore formation in step (1), add 45 wt% nitric acid in a mass ratio of 1:6, stir and heat to 110 ° C for reflux treatment, react for 3 hours, wash to neutrality, filter and dry to obtain 84.6 mg of porous carbon black material (1100-1400 m 2 / g) standby; (3) Take 84.6 mg of the porous carbon black material in step (2), add a mixed amino acid solution (a solution prepared by mixing lysine, phenylalanine and purified water in a mass volume ratio of 3.5 mg:2.8 mg:12 mL) in a mass volume ratio of 1:1.7 (mg / ml), adjust the pH to 7.5, heat to 60°C, and perform ultrasonic dispersion treatment (ultrasonic dispersion power of 450 W, ultrasonic dispersion time of 25 min), rinse, filter, and dry to obtain 119.1 mg of carbon black material loaded with a mixed amino acid adsorption layer for use; (4) 119.1 mg of the carbon black material loaded with the mixed amino acid adsorption layer in step (3) was taken, and deionized water was added with stirring at a mass volume ratio of 1:1.4 (mg / ml), and then 0.13 mol / L of silver nitrate solution was added (the mass ratio of the carbon black material to the silver nitrate in the silver nitrate solution was 2:1). After stirring and mixing, 0.13 mol / L of sodium borohydride solution was added dropwise and continued to stir and mix. The reaction pH was controlled to 9 and the reaction temperature was controlled to 35°C. After the reaction was completed, filtration, washing, and drying were performed to obtain 156.8 mg of a highly conductive carbon black product. Example 4

[0019] A production process for improving the conductivity of carbon black comprises the following steps: (1) Take 100 mg of carbon black with a particle size of 30-40 nm (specific surface area of ​​80-130 m 2 / g), firstly introduce nitrogen for preheating treatment (heat the carbon black material to 420℃ at a heating rate of 8.5℃ / min), then introduce carbon dioxide at a flow rate of 50mL / min for activation treatment (the activation temperature is 850℃ and the activation time is 1.8h), introduce nitrogen again to cool to room temperature, wash with deionized water, and dry to obtain 91.7mg of carbon black material after pore formation (specific surface area of ​​900-1200m 2 / g) standby; (2) Take 91.7 mg of the carbon black material after pore formation in step (1), add 48 wt% nitric acid in a mass ratio of 1:7, stir and heat to 115 ° C for reflux treatment, react for 3.5 hours, wash to neutrality, filter and dry to obtain 83.1 mg of porous carbon black material (specific surface area of ​​1200-1500m 2 / g) standby; (3) Take 83.1 mg of the porous carbon black material in step (2), add a mixed amino acid solution (a solution prepared by mixing lysine, phenylalanine and purified water in a mass volume ratio of 3 mg:2.5 mg:10 mL) in a mass volume ratio of 1:1.3 (mg / ml), adjust the pH to 7.8, heat to 65°C, and perform ultrasonic dispersion treatment (ultrasonic dispersion power is 480 W, ultrasonic dispersion time is 30 min), rinse, filter, and dry to obtain 108.8 mg of carbon black material loaded with a mixed amino acid adsorption layer for use; (4) Take 108.8 mg of the carbon black material loaded with the mixed amino acid adsorption layer in step (3), add deionized water in a mass-to-volume ratio of 1:1.5 (mg / ml), stir and mix, then add 0.16 mol / L silver nitrate solution (the mass ratio of the carbon black material to the silver nitrate in the silver nitrate solution is 2.5:1), stir and mix, then add dropwise 0.16 mol / L sodium borohydride solution and continue stirring and mixing, control the pH to 9.5, control the reaction temperature to 40°C, filter, wash and dry after the reaction is completed, and obtain 136.3 mg of a highly conductive carbon black product. Example 5

[0020] A production process for improving the conductivity of carbon black comprises the following steps: (1) Take 100 mg of carbon black with a particle size of 30-40 nm (specific surface area of ​​80-130 m 2 / g), firstly introduce nitrogen for preheating treatment (heat the carbon black material to 450℃ at a heating rate of 10℃ / min), then introduce carbon dioxide at a flow rate of 60mL / min for activation treatment (the activation temperature is 900℃ and the activation time is 2h), introduce nitrogen again to cool to room temperature, wash with deionized water, and dry to obtain 90.2mg of carbon black material (specific surface area of ​​900-1300m2) after pore formation. 2 / g) standby; (2) Take 90.2 mg of the carbon black material after pore formation in step (1), add 50 wt% nitric acid in a mass ratio of 1:8, stir and heat to 120 ° C for reflux treatment, react for 4 hours, wash to neutrality, filter and dry to obtain 81.1 mg of porous carbon black material (specific surface area of ​​1300-1600 m 2 / g) standby; (3) Take 81.1 mg of the porous carbon black material in step (2), add a mixed amino acid solution (a solution prepared by mixing lysine, phenylalanine and purified water in a mass volume ratio of 4 mg:3 mg:15 mL) in a mass volume ratio of 1:1.8 (mg / ml), adjust the pH to 8, heat to 70°C, and perform ultrasonic dispersion treatment (ultrasonic dispersion power is 500 W, ultrasonic dispersion time is 35 min), rinse, filter, and dry to obtain 113.3 mg of carbon black material loaded with a mixed amino acid adsorption layer for use; (4) Take 113.3 mg of the carbon black material loaded with the mixed amino acid adsorption layer in step (3), add deionized water in a mass-to-volume ratio of 1:1.5 (mg / ml), stir and mix, then add 0.18 mol / L silver nitrate solution (the mass ratio of the carbon black material to the silver nitrate in the silver nitrate solution is 2.3:1), stir and mix, then add dropwise 0.18 mol / L sodium borohydride solution and continue stirring and mixing, control the pH to 10, the reaction temperature to 45°C, filter, wash and dry after the reaction is completed, and then obtain 144.3 mg of a highly conductive carbon black product.

[0021] To better demonstrate that the process of the present invention can produce highly conductive carbon black products, the following comparative examples are provided, using Example 3 as a reference. The DBP oil absorption values ​​of the conductive carbon blacks in Examples 1-5 and the comparative example were measured using the experimental method specified in the national standard GB / T3780.2-2003, "Carbon Black Part 2: Determination of Dibutyl Phthalate Absorption." The resistivity of the conductive carbon blacks in Examples 1-5 and the comparative example was measured using the method specified in the national standard GB / T3781.9-2006, "Acetylene Black Part 9: Determination of Resistivity." See Table 1 for details.

[0022] Comparative Example 1 The difference from Example 3 is that the pH is adjusted to 6 in step (3), and the other operations are the same; wherein step (3) obtains 92.9 mg of carbon black material loaded with a mixed amino acid adsorption layer for standby use; and step (4) obtains 104.6 mg of a highly conductive carbon black product.

[0023] Comparative Example 2 The difference from Example 3 is that the pH is adjusted to 9 in step (3), and the other operations are the same; wherein 95.8 mg of carbon black material loaded with a mixed amino acid adsorption layer is obtained in step (3) for standby use; and 110.7 mg of a highly conductive carbon black product is obtained in step (4).

[0024] Comparative Example 3 The difference from Example 3 is that the heating to 45° C. is performed in step (3), and the remaining operations are the same; wherein 98.7 mg of carbon black material loaded with a mixed amino acid adsorption layer is obtained in step (3) for standby use; and 112.3 mg of a highly conductive carbon black product is obtained in step (4).

[0025] Comparative Example 4 The difference from Example 3 is that the temperature is heated to 75° C. in step (3), and the remaining operations are the same. In step (3), 107.9 mg of carbon black material loaded with a mixed amino acid adsorption layer is obtained for standby use; in step (4), 123.4 mg of a highly conductive carbon black product is obtained.

[0026] Comparative Example 5 The difference from Example 3 is that the reaction temperature in step (4) is controlled to 20° C., and the other operations are the same. In step (4), 140.5 mg of a highly conductive carbon black product is obtained.

[0027] Comparative Example 6 The difference from Example 3 is that the reaction temperature in step (4) is controlled to 50°C, and the other operations are the same. In step (4), 134.6 mg of a highly conductive carbon black product is obtained.

[0028] Comparative Example 7 The difference from Example 3 is that the mass ratio of the carbon black material to the silver nitrate in the silver nitrate solution in step (4) is 1.5:1, and the remaining operations are the same. In step (4), 164.2 mg of a highly conductive carbon black product is obtained.

[0029] Comparative Example 8 The difference from Example 3 is that the mass ratio of the carbon black material to the silver nitrate in the silver nitrate solution in step (4) is 4:1, and the remaining operations are the same. In step (4), 138 mg of a highly conductive carbon black product is obtained.

[0030] Comparative Example 9 The difference from Example 3 is that step (3) is omitted, and the remaining operations are the same. In step (4), 94.7 mg of a highly conductive carbon black product is obtained.

[0031]

[0032] From the data in Table 1, it can be found that the carbon black product prepared by the process method of Example 3 of the present invention has better overall conductive properties than other embodiments and comparative examples.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A production process for improving the electrical conductivity of carbon black, characterized in that: The production process comprises the following steps: (1) Take carbon black, introduce nitrogen into it for preheating, then introduce carbon dioxide into it for activation, and after the activation is completed, introduce nitrogen into it again to cool it to room temperature, wash it, and dry it to obtain the pore-forming carbon black material for use; (2) taking the carbon black material after pore formation described in step (1), adding nitric acid and heating and stirring, washing to neutrality after the reaction, filtering, and drying the obtained porous carbon black material for use; (3) Take the porous carbon black material described in step (2), add the mixed amino acid solution, adjust the pH, heat, ultrasonically disperse, filter, and dry to obtain a carbon black material loaded with a mixed amino acid adsorption layer for later use; (4) Take the carbon black material loaded with the mixed amino acid adsorption layer in step (3), add deionized water and stir, add silver nitrate solution to the obtained carbon black liquid, stir and mix, then add sodium borohydride solution dropwise and continue stirring, control the pH and reaction temperature, filter, wash and dry after the reaction is completed, and then obtain a highly conductive carbon black product.

2. A production process for improving carbon black conductivity according to claim 1, characterized in that: During the preheating treatment in step (1), the carbon black material is heated to 300-450°C at a heating rate of 5-10°C / min.

3. A production process for improving the conductivity of carbon black according to claim 1, characterized in that: During the activation treatment in step (1), the flow rate of carbon dioxide is 20-60 mL / min, the temperature of the activation treatment is controlled to be 700-900° C., and the time of the activation treatment is controlled to be 1-2 h.

4. A production process for improving carbon black conductivity according to claim 1, characterized in that: The carbon black material after pore formation in step (2) is mixed with the nitric acid in a mass ratio of 1:4-8, and the concentration of the nitric acid is 40-50wt%.

5. A production process for improving carbon black conductivity according to claim 1, characterized in that: In step (2), the temperature is heated to 100-120°C and the reaction time is controlled to be 2-4 hours.

6. A production process for improving carbon black conductivity according to claim 1, characterized in that: The porous carbon black material in step (3) is mixed with the mixed amino acid solution in a mass volume ratio of 1 mg:1.2 ml-1.8 ml; the mixed amino acid solution is a solution formed by mixing lysine, phenylalanine and purified water in a mass volume ratio of 2-4 mg:1-3 mg:5-15 mL.

7. A production process for improving the conductivity of carbon black according to claim 1, characterized in that: In step (3), the pH is adjusted to 7-8, the mixture is heated to 50-70°C, the power of ultrasonic dispersion is 400-500w, and the time of ultrasonic dispersion is 15-35min.

8. A production process for improving carbon black conductivity according to claim 1, characterized in that: In step (4), the carbon black material loaded with the mixed amino acid adsorption layer is mixed with the deionized water in a mass volume ratio of 1 mg:1.2 ml-1.5 ml.

9. A production process for improving the conductivity of carbon black according to claim 1, characterized in that: The mass ratio of the carbon black material loaded with the mixed amino acid adsorption layer in step (4) to the silver nitrate in the silver nitrate solution is 2-3.2:1, and the concentration of the silver nitrate solution and the concentration of the sodium borohydride are both 0.08-0.18 mol / L.

10. The production process for improving the conductivity of carbon black according to claim 1, characterized in that: In step (4), the pH is controlled at 8-10 and the reaction temperature is controlled at 25-45°C.

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