Production method and application of medium-high pigment carbon black

Abstract

The invention relates to the technical field of high-pigment carbon black, in particular to a production method and application of medium-high-pigment carbon black. Raw oil, air and natural gas are introduced into the carbon black reaction furnace for secondary combustion; quenching for four times at the outlet of the reaction furnace after combustion; and arranging a main bag filter at an outlet of the reaction furnace to collect carbon black, and granulating by using a dry granulator to obtain the medium-high pigment carbon black. By optimizing the carbon black production process, on the premise of not using strong acid oxidation, the oxygen-containing functional group can be efficiently introduced on the surface of the carbon black only by accurately regulating and controlling the air inlet amount, the reaction temperature and the retention time. According to the method, the problems of pH imbalance and activity reduction caused by traditional acid treatment are avoided, the surface polarity of the carbon black can be remarkably enhanced, meanwhile, a low pH value of 6-7 and high surface activity are kept, the iodine absorption value is increased, the coloring power is enhanced, and the contradiction of activity loss and performance reduction existing in a traditional oxidation process is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of high - pigment carbon black, and more specifically, to a production method and application of medium - high - pigment carbon black. Background Art

[0002] As a petrochemical material with a long history, carbon black was first used in the preparation of ink and black pigments. With the development of industrial technology, carbon black has evolved into a material system with various functional characteristics, and its physical and chemical properties mainly depend on key factors such as raw material types, pyrolysis processes, and production conditions. Among various types of carbon black, pigment carbon black occupies an important position due to its special applications in fields such as inks, coatings, and plastics, accounting for about 5% - 8% of the total global carbon black production, and its market size is second only to carbon black for rubber use. In the performance evaluation system of pigment carbon black, the plate blackness, as the core index, directly reflects the dispersion performance of the product. Since the surface of conventional carbon black lacks polar functional groups and is difficult to be compatible with polar solvent systems, modern production processes introduce surface oxidation treatment technology to construct oxygen - containing functional groups on the surface of carbon black particles to enhance its surface polarity, thereby significantly improving its dispersion stability in media such as coatings, paints, and inks. This technological breakthrough has greatly expanded the application scope of pigment carbon black in high - quality coatings and printing fields.

[0003] However, the methods for improving the dispersibility of carbon black through oxidation treatment in the prior art still have certain limitations. On the one hand, excessive oxidation will cause the pH value of the carbon black surface to increase (usually reaching 8 - 10), making it strongly alkaline. This not only may affect the stability of some pH - sensitive resin systems but also reduce the activity of carbon black and its compatibility with the base material. On the other hand, although carbon black with a high degree of oxidation has good dispersibility, its blackness and coloring power tend to decrease, and at the same time, the oil absorption value increases, affecting the rheological properties of the final product. In addition, the oxidation process usually requires strong acid treatment or high - temperature oxidation, which not only consumes a large amount of energy but also may cause environmental problems such as waste water and waste gas. Therefore, how to control the pH value of carbon black, maintain a high surface activity, and optimize the production process while ensuring good dispersibility is still a difficult problem to be solved in the current technical field of pigment carbon black. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, an object of one aspect of the present invention is to provide a production method of medium - high - pigment carbon black, and the specific steps of the production method are as follows: S1. Feedstock oil, air, and natural gas are introduced into the carbon black reaction furnace for secondary combustion. S2. Four - stage rapid cooling is set at the outlet of the reaction furnace after combustion is completed. S3. A main bag filter is set at the outlet of the reaction furnace to collect carbon black, and then granulation is carried out using a dry granulator to obtain medium - high - pigment carbon black pellets.

[0005] Preferably, in S1, the flow rate of the feedstock oil is 1800 kg / h, and the preheating temperature of the feedstock oil is controlled at 190°C to 210°C.

[0006] Preferably, in S1, the volume ratio of air to natural gas is 17 - 18:1.

[0007] Preferably, in S1, the air flow rate is 6500 Nm 3 / h, and the natural gas flow rate is 400 Nm 3 / h.

[0008] Preferably, in S1, the secondary combustion temperature is 1600°C to 1700°C.

[0009] Preferably, in S2, for the four - stage rapid cooling, the temperature of the first rapid cooling stage is 1100°C to 1050°C, the temperature of the second rapid cooling stage is 1050°C to 900°C, the temperature of the third rapid cooling is 600°C to 500°C, and the temperature of the fourth rapid cooling is 500°C to 350°C.

[0010] Preferably, in S3, the time interval between the shakings of the main bag filter is adjusted to 10 - 12 s.

[0011] Preferably, in S3, the frequency of the dry granulator is controlled at 0.8 Hz.

[0012] Preferably, the medium - high pigment carbon black is in powder or granular form.

[0013] Another object of the present invention is to provide an application of medium - high pigment carbon black, and the medium - high pigment carbon black is applied in inks, coatings, batteries, plastics, and papermaking.

[0014] The beneficial effects of the present invention are as follows: By optimizing the carbon black production process, the present invention can efficiently introduce oxygen - containing functional groups on the carbon black surface only by precisely controlling the air intake, reaction temperature, and residence time without using strong acid oxidation. This method not only avoids the problems of pH imbalance and activity decline caused by traditional acid treatment, but also significantly enhances the surface polarity of carbon black, while maintaining a relatively low pH value of 6 - 7 and high surface activity, improving the iodine absorption value and coloring ability, and effectively solving the contradiction between activity loss and performance decline existing in traditional oxidation processes.

[0015] The additional aspects and advantages of the present invention will become apparent in the following description or be understood through the practice of the present invention. Detailed Embodiments

[0016] To more clearly understand the above objects, features, and advantages of the present invention, the present invention will be further described in detail below with reference to specific embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments may be combined with each other.

[0017] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0018] Example 1 Feedstock oil, air, and natural gas are introduced into the carbon black reactor for secondary combustion. The volume ratio of air to natural gas entering the reactor is controlled to be 18:1, the air flow rate is 6500 Nm 3 / h, and the natural gas flow rate is 400 Nm 3 / h, allowing more surplus air to enter the reaction chamber and participate in the secondary combustion with the feedstock oil in the reaction chamber to increase the carbon black cracking reaction temperature; the feedstock oil flow rate is 1800 kg / h, the preheating temperature of the feedstock oil is controlled at 200 °C, and the secondary combustion temperature is 1600 - 1700 °C; Four quenching steps are set at the outlet of the reactor. The temperature of the first quenching section is controlled at 1080 °C, the temperature of the second quenching section is 980 °C, and three quenching steps and four quenching steps are set after the high-altitude preheater. The temperature of the third quenching is 580 °C, and the temperature of the fourth quenching is 480 °C to extend the reaction time, enable sufficient contact between the carbon black surface and oxygen before the reaction terminates, increase the oxygen-containing groups on the carbon black surface, and improve the surface activity of the carbon black.

[0019] A main bag filter is set at the outlet of the reactor to collect carbon black. The vibration time interval of the main bag filter is 12 s to increase the contact time between carbon black and oxygen, increase the surface oxidation time of carbon black, reduce the pH of carbon black, and improve the surface activity of carbon black; then a dry granulator is used for granulation to obtain medium-high pigment carbon black, and the frequency of the dry granulator is controlled at about 0.8 Hz.

[0020] Example 2 Feedstock oil, air, and natural gas are introduced into the carbon black reactor for secondary combustion. The volume ratio of air to natural gas entering the reactor is controlled to be 18:1, the air flow rate is 6500 Nm 3 / h, and the natural gas flow rate is 400 Nm 3 / h, allowing more surplus air to enter the reaction chamber and participate in the secondary combustion with the feedstock oil in the reaction chamber to increase the carbon black cracking reaction temperature; the feedstock oil flow rate is 1800 kg / h, the preheating temperature of the feedstock oil is controlled at 200 °C, and the secondary combustion temperature is 1600 - 1700 °C; Four-stage quenching is set at the reactor outlet to complete combustion. The temperature of the first-stage quenching section is controlled at 1050 °C, and the temperature of the second-stage quenching section is 940 °C. The third-stage quenching and the fourth-stage quenching are set after the high-altitude preheater. The temperature of the third-stage quenching is 550 °C, and the temperature of the fourth-stage quenching is 430 °C, so as to extend the reaction time, make the carbon black surface fully contact with oxygen before the reaction terminates, increase the oxygen-containing groups on the carbon black surface, and improve the surface activity of carbon black.

[0021] A main bag filter is set at the reactor outlet to collect carbon black. The vibration time interval of the main bag filter is 11 s, so as to increase the contact time between carbon black and oxygen, increase the surface oxidation time of carbon black, reduce the pH of carbon black, and improve the surface activity of carbon black; then a dry granulator is used for granulation to obtain medium-high pigment carbon black, and the frequency of the dry granulator is controlled at about 0.8 Hz.

[0022] Example Three Feedstock oil, air and natural gas are introduced into the carbon black reactor for secondary combustion. The volume ratio of air to natural gas entering the reactor is controlled at 18:1, the air flow rate is 6500 Nm 3 / H, and the natural gas flow rate is 400 Nm 3 / H, so that more surplus air enters the reaction chamber to participate in the secondary combustion with the feedstock oil in the reaction chamber, and the carbon black cracking reaction temperature is increased; the feedstock oil flow rate is 1800 kg / h, the preheating temperature of the feedstock oil is controlled at 200 °C, and the secondary combustion temperature is 1600 - 1700 °C; Four-stage quenching is set at the reactor outlet to complete combustion. The temperature of the first-stage quenching section is controlled at 1060 °C, and the temperature of the second-stage quenching section is 920 °C. The third-stage quenching and the fourth-stage quenching are set after the high-altitude preheater. The temperature of the third-stage quenching is 510 °C, and the temperature of the fourth-stage quenching is 400 °C, so as to extend the reaction time, make the carbon black surface fully contact with oxygen before the reaction terminates, increase the oxygen-containing groups on the carbon black surface, and improve the surface activity of carbon black.

[0023] A main bag filter is set at the reactor outlet to collect carbon black. The vibration time interval of the main bag filter is 10 s, so as to increase the contact time between carbon black and oxygen, increase the surface oxidation time of carbon black, reduce the pH of carbon black, and improve the surface activity of carbon black; then a dry granulator is used for granulation to obtain medium-high pigment carbon black, and the frequency of the dry granulator is controlled at about 0.8 Hz.

[0024] The quality indexes of the medium-high pigment carbon black obtained by the production method of the present invention and the general medium-high pigment carbon black are compared as shown in Table 1 below.

[0025] Table 1. Comparison of quality indexes between the high pigment carbon black of the present invention and the general medium-high pigment carbon black Name of raw material General medium-high pigment carbon black Modified carbon black Modified carbon black Modified carbon black Modified carbon black Test items Index Index Measured value 1 Measured value 2 Measured value 3 Iodine absorption value g / kg 150-200 160-220 218 210 203 <![CDATA[DBP absorption value 10 -5 m 3 / kg]]> 45-55 40-50 45 44 46 Color strength % 125±5 130±5 132 133 131 <![CDATA[Nitrogen adsorption specific surface area 10 3 m 2 / kg]]> 120-160 130-180 150 148 152 Ash content % ≤0.7 ≤0.7 0.5 0.4 0.5 pH 8-10 6-8 6.8 7.2 7.0 Impurities None None None None None Toluene transmittance % ≥98 ≥99 99.2 99.3 99.1 Residue on 325-mesh sieve mg / kg ≥50 ≤50 20 19 21 Heating loss % ≤1.0% ≤1.0% 0.6 0.5 0.6 The medium-high pigment carbon black obtained by the above process and the general medium-high pigment carbon black are used for PVC plate making under the same conditions, and a comparative test is carried out.

[0026] Weigh 50 g of PVC and 0.25 g of the obtained medium-high pigment carbon black. Mix the obtained medium-high pigment carbon black into the weighed PVC and stir to mix evenly. Wear gloves and pour the evenly mixed PVC between the two rolls of the open mill. Press the start button to start the rollers and start timing simultaneously. Use a spatula to push the materials on both sides of the rollers towards the middle, clean up the materials scattered in the receiving tray, pour them between the rollers for mixing, and try to mix all of them to reduce losses. When all the materials are mixed and there is no obvious white agent, cut it and wrap it around the rear roller. Keep using the spatula to strike the board left and right to mix the materials on both sides towards the middle. When the timer reaches 10 min, adjust the roll gap to 0.4 mm, and continue to mix the materials on both sides towards the middle. Stop the open mill at 11 min, cut the material with a cutter, and place the material sheet on a flat, dry, and clean metal plate. Mark the information of the medium-high pigment carbon black obtained by the above process and the general medium-high pigment carbon black. At least two material sheets of PVC are mixed for vulcanization comparison. Cut out small pieces of the same size from the two material sheets and place them in the middle of the glass surface of the stainless steel mold. Cover the other layer of the mold. After the temperature of the flat plate of the vulcanizer and the mold stabilizes at (170 ± 1) °C, place the mold in the center of the lower flat plate and long-press the mold closing button. Control the pressure at 3 MPa, and open the mold after timing for 45 s. Quickly place it in the cooling vulcanizer to close the mold for cooling. Control the pressure at 3 MPa, take it out and open the mold after timing for 1.5 min. Mark the information of the medium-high pigment carbon black obtained by the above process and the general medium-high pigment carbon black, and place it on a medical viewing lamp sheet for comparison.

[0027] Comparison of the data of the blackness index of the struck board: Standard sample Example 1 Example 2 Example 3 L* 29.62 28.13 27.93 27.73 a* -0.06 -0.08 -0.09 -0.07 b* -0.98 -0.94 -0.95 -0.95 ΔL -1.49 -1.69 -2.39 Δa -0.02 -0.03 -0.01 Δb 0.04 0.03 0.03 ΔE1 = 1.49, ΔE2 = 1.69, ΔE1.89 L represents light and dark, and the lower ΔL is, the blacker it is.

[0028] ΔE represents the total color difference. ΔE = √(ΔL) 2 +(Δa) 2 +(Δb) 2 The blackness of the struck board of the medium-high pigment carbon black obtained by the described production method in the test is significantly better than that of the general medium-high pigment carbon black.

[0029] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can also have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for producing medium and high pigment carbon black, characterized in that: The specific steps of the production method are as follows: S1. Feeding raw oil, air and natural gas into the carbon black reactor for secondary combustion; S2. After the combustion is completed, four quenching steps are set at the reactor outlet; S3. A main bag filter is set at the reactor outlet to collect carbon black, and then a dry granulator is used to granulate it to obtain medium and high pigment carbon black.

2. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: The crude oil flow rate in S1 is 1800 kg / h, and the crude oil preheating temperature is controlled at 190°C~210°C.

3. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: The volume ratio of air to natural gas in S1 is 17-18:

1.

4. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: The air flow rate in S1 is 6500Nm 3 / H, natural gas flow rate is 400Nm 3 / H.

5. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: The secondary combustion temperature in S1 is 1600-1700°C.

6. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: In the four rapid cooling in S2, the temperature of the first rapid cooling section is 1100-1050°C, the temperature of the second rapid cooling section is 1050°C-900°C, the temperature of the third rapid cooling section is 600°C-500°C, and the temperature of the fourth rapid cooling section is 500°C-350°C.

7. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: The vibration time interval of the main bag filter in S3 is adjusted to 10-12s.

8. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: The frequency of the dry granulator in S3 is controlled at 0.8 Hz.

9. The method for producing medium-high pigment carbon black according to claim 1, characterized in that: The medium and high color carbon black is in powder or granular form.

10. The use of a medium-high pigment carbon black according to claim 1, characterized in that: The medium and high pigment carbon black is used in ink, coating, battery, plastic and paper making.