Highly conductive carbon black powder and manufacturing method thereof

Abstract

Disclosed are a highly conductive carbon black powder having excellent processability and dispersibility and clearly reducing grit, which is an impurity, and a manufacturing method thereof. To this end, the highly conductive carbon black powder and the manufacturing method thereof according to the present invention introduce a feedstock two-stage spray method to produce carbon black so as to have a wide aggregate size distribution (ASD), thereby improving dispersibility and processability without deteriorating the conductivity of the carbon black powder.

Description

High-conductivity carbon black powder and its manufacturing method

[0001] The present invention relates to a high-conductivity carbon black powder and a method for producing the same, and more particularly, to a high-conductivity carbon black powder having excellent processability and dispersibility and significantly reducing grit, which is an impurity, and a method for producing the same.

[0002]

[0003] Carbon black refers to an aggregate of very fine spherical particles obtained through the incomplete combustion of hydrocarbons or carbon-containing compounds. Carbon black forms primary particles in a reactor, and these primary particles fuse together to form grape-shaped aggregates. Meanwhile, carbon black can be broadly divided into acetylene black and furnace black. Among these, furnace black has the advantage of being inexpensive, but has the disadvantage of being difficult to achieve high crystallinity compared to acetylene black.

[0004] Carbon black's physical properties influence the quality of the materials it is used in. These properties include crystallinity, specific surface area, structure, and particle size. Carbon black's properties can be tailored through various post-treatments. Carbon black is used in a variety of fields, including as an industrial additive, industrial paints, coating compositions, and various printed materials.

[0005] Carbon black, which has excellent electrical conductivity, is widely used as a material for wires and ESD (Electro-Static Discharge), and in particular, it serves as a key conductive filler in the semi-conductive part of wires.

[0006] In the case of wires, surface smoothness is very important during extrusion, and if the surface is not flat due to surface protrusions, it causes electrical treeing of the wire, which causes problems such as wire breakage or shortened lifespan.

[0007] Conventional carbon blacks with excellent electrical conductivity are typically manufactured with a high OAN (structure). However, this leads to poor dispersibility and processability, which can lead to the formation of protrusions on the wire surface. Furthermore, grit, an impurity in carbon black, can also cause surface protrusions if located on the compound surface.

[0008]

[0009] In view of the above-described technical problems, the present invention aims to provide a highly conductive carbon black powder having excellent processability and dispersibility and significantly reducing grit, which is an impurity, and a method for producing the same.

[0010]

[0011] In order to achieve the above object, a method for producing high-conductivity carbon black powder according to an embodiment of the present invention comprises the steps of: (a) producing carbon black in a reactor and then filtering it by passing it through a main bag filter; (b) transferring the filtered carbon black to a grit trap system to primarily remove impurities in the carbon black having relatively large particle sizes; (c) transferring the carbon black from which the impurities have been primarily removed to a low grit system to secondarily remove impurities in the carbon black having relatively small particle sizes; (d) transferring the carbon black from which the impurities have been secondarily removed to a grinder to grind it; and (e) pelletizing the ground product and then drying it to obtain high-conductivity carbon black powder.

[0012] In the above step (a), the manufacturing temperature of the carbon black is carried out under conditions of 1,300 to 1,800°C.

[0013] In the step (a), the reactor comprises at least one supply section having an air supply section and a fuel supply section; a reaction section into which high-temperature combustion gas introduced through the supply section is introduced; a discharge section (throat) extending from the reaction section and formed to have a diameter decreasing from the reaction section; and a quench section extending from the discharge section and having a diameter larger than the discharge section.

[0014] The above discharge unit and rapid cooling unit are designed to satisfy the following equation 1.

[0015] Equation 1: 0.36 ≤ (diameter of discharge part / diameter of quenching part) ≤ 0.44

[0016] The above grit trap system is installed so as to be connected to the discharge portion of the reactor.

[0017] The above grit trap system is designed so that the pipe through which the carbon black flows is installed vertically and air is injected into the inside of the pipe to form a vortex, thereby increasing the residence time of the carbon black transported inside the pipe.

[0018] The feedstock is supplied in a two-stage feedstock injection method that is connected to the discharge portion of the above reactor and injects the feedstock from two different locations of the discharge portion of the above reactor.

[0019] The above feedstock two-stage injection method primarily supplies at a rate of 300 to 600 kg / hour using a feedstock nozzle, and secondarily supplies at a rate of 1,000 to 2,000 kg / hour using a feedstock nozzle.

[0020] In the first supply using the above feedstock nozzle, 20 to 25 wt% of the total 100 wt% is supplied, and in the second supply using the above feedstock nozzle, 75 to 80 wt% of the total 100 wt% is supplied.

[0021] The above feedstock two-stage injection is connected to the discharge portion of the reactor, and feedstock is injected simultaneously from two different locations of the discharge portion of the reactor.

[0022] In the above grit trap system, grit exceeding an average diameter of 150㎛ is removed.

[0023] In the above step (d), the pulverization is performed using any one selected from among a hammer mill, a high-speed mixer, a ball mill, and an air jet mill.

[0024]

[0025] A high-conductivity carbon black powder according to an embodiment of the present invention for achieving the above purpose is a carbon black powder manufactured by a high-conductivity carbon black powder manufacturing method, wherein the carbon black powder is characterized in that it has a grit having an average diameter of 50 to 150 ㎛ and is 10 ppm or less.

[0026]

[0027] Highly conductive carbon black powder and its manufacturing method according to the present invention were produced by changing the diameter of the discharge part of the reactor to control the ratio with the diameter of the quenching part, and reflecting the operating conditions accordingly.

[0028] In particular, the high-conductivity carbon black powder and the method for producing the same according to the present invention introduce a two-stage feedstock injection method to produce a wide aggregate size distribution (ASD) of carbon black, thereby improving dispersibility and processability without lowering the conductivity of the carbon black powder.

[0029] To this end, the high-conductivity carbon black powder and the manufacturing method thereof according to the present invention are designed such that a pipe through which carbon black flows is installed vertically, and a grit trap system is designed such that air is injected into the inside of the pipe to form a vortex to increase the residence time of the carbon black being transported within the pipe. Accordingly, grit impurities having relatively heavy weights fall in the direction of gravity as the residence time increases and decreases due to the vortex, thereby removing grit of relatively large size in advance before the carbon black is introduced into the low-grit system, thereby manufacturing carbon black powder with reduced grit overall.

[0030] As a result, the high-conductivity carbon black powder manufactured by the method according to the present invention not only has excellent electrical conductivity but also excellent processability and dispersibility, and can significantly reduce grit, which is the cause of surface protrusions.

[0031] Therefore, the highly conductive carbon black powder manufactured by the method according to the present invention is suitable for use as a high-voltage wire semiconducting masterbatch and ESD (Electro-Static Discharge) material.

[0032] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0033]

[0034] Figure 1 is a process flow diagram showing a method for manufacturing high-conductivity carbon black powder according to an embodiment of the present invention.

[0035] Figure 2 is a process schematic diagram for explaining a method for manufacturing high-conductivity carbon black powder according to an embodiment of the present invention.

[0036] Figure 3 is a cross-sectional view specifically showing a reactor according to an example of the present invention.

[0037] Figure 4 is a schematic diagram illustrating the connection structure of a reactor and a grit trap system according to an example of the present invention.

[0038] Figure 5 is a computational simulation photograph of a grit trap system according to an embodiment of the present invention.

[0039] Figure 6 is a graph showing the results of ASD (aggregate size distribution) analysis of carbon black powders manufactured according to Example 1 and Comparative Examples 1 to 2.

[0040] Figure 7 is a photograph of a cross-section of a carbon black compound manufactured according to Example 1 and Comparative Examples 1 to 2.

[0041] Figure 8 is a photograph showing the surface of a carbon black compound manufactured according to Example 1 and Comparative Examples 1 to 2.

[0042]

[0043] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0044] Any details not described in this specification that can be sufficiently technically inferred by a person skilled in the art will be omitted.

[0045] In this specification, the phrase "any component is disposed "on (or below)" a component or "on (or below)" a component may mean not only that any component is disposed in contact with the upper surface (or lower surface) of said component, but also that another component may be interposed between said component and any component disposed on (or below) said component.

[0046] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "contains," "has (has)," or "includes" should not necessarily be construed as including all components described in the specification, and should be construed to mean that some of the components may not be included, or that additional components may be included.

[0047] Hereinafter, with reference to the attached drawings, a high-conductivity carbon black powder and a method for manufacturing the same according to a preferred embodiment of the present invention will be described in detail.

[0048]

[0049] FIG. 1 is a process flow diagram showing a method for manufacturing a high-conductivity carbon black powder according to an embodiment of the present invention, and FIG. 2 is a process schematic diagram explaining a method for manufacturing a high-conductivity carbon black powder according to an embodiment of the present invention. In addition, FIG. 3 is a cross-sectional view specifically showing a reactor according to an example of the present invention, and FIG. 4 is a schematic diagram explaining the connection structure of a reactor and a grit trap system according to an example of the present invention.

[0050] Referring to FIGS. 1 and 2, a method for manufacturing a high-conductivity carbon black powder according to an embodiment of the present invention includes a carbon black manufacturing and filtering step (S110), a first impurity removal step (S120), a second impurity removal step (S130), a grinding step (S140), and a pelletizing and drying step (S150).

[0051]

[0052] Carbon black manufacturing and filtering

[0053] In the carbon black manufacturing and filtering step (S110), granulated carbon black is manufactured in a reactor (110) and then filtered by passing it through a main bag filter (120).

[0054] At this stage, it is desirable to manufacture carbon black at a temperature of 1,300 to 1,800°C.

[0055] As illustrated in FIG. 3, the reactor (110) may include at least one supply section (112) having an air supply section and a fuel supply section, a reaction section (114) into which high-temperature combustion gas introduced through the supply section (112) is introduced, a discharge section (115: throat) extending from the reaction section (114) and formed to have a diameter decreasing from the reaction section (114), and a quench section (116) extending from the discharge section (115) and having a diameter larger than that of the discharge section (115).

[0056] In particular, in the present invention, it is preferable that the discharge unit (115) and the rapid cooling unit (116) be designed to satisfy the following equation 1.

[0057] Equation 1: 0.36 ≤ (diameter of discharge part / diameter of quenching part) ≤ 0.44

[0058] In this way, if the ratio of (diameter of discharge part / diameter of quenching part) does not satisfy 0.36 to 0.44, it becomes difficult to produce a wide ASD (aggregate size distribution) of carbon black, and there is a concern that dispersibility and processability may not be good.

[0059]

[0060] Primary impurity removal

[0061] In the first impurity removal step (S120), the filtered carbon black is transferred to a grit trap system (130) to primarily remove impurities in the carbon black with relatively large particle sizes.

[0062] Here, as shown in FIG. 4, the grit trap system (130) may be installed to communicate with the discharge portion (115) of the reactor (110).

[0063] At this time, the grit trap system (130) is designed so that the pipe through which carbon black flows is installed vertically, and air is injected into the inside of the pipe to form a vortex, thereby increasing the residence time of the carbon black transported inside the pipe.

[0064] In this step, the feedstock can be supplied in a two-stage feedstock injection method in which the feedstock is injected from two different locations in the discharge portion (115) of the reactor (110). At this time, the two-stage feedstock injection method can sequentially inject the feedstock from two different locations in the discharge portion (115) of the reactor (110).

[0065] In this case, it is desirable that the feedstock two-stage injection method primarily supplies at a rate of 300 to 600 kg / hour using the feedstock nozzle, and secondarily supplies at a rate of 1,000 to 2,000 kg / hour using the feedstock nozzle.

[0066] More specifically, in the first supply using the feedstock nozzle, 20 to 25 wt% of the total 100 wt% is supplied, and in the second supply using the feedstock nozzle, 75 to 80 wt% of the total 100 wt% is supplied.

[0067] Additionally, the feedstock two-stage injection can simultaneously inject the feedstock from two different locations in the discharge portion (115) of the reactor (110).

[0068] To this end, the feedstock two-stage injection is mounted so that the feedstock nozzle is inserted into the part indicated by a circle in the discharge portion (115) of the reactor (110). Accordingly, the feedstock two-stage injection is performed in the discharge portion (115) of the reactor (110) as a method for producing a wide aggregate size distribution (ASD).

[0069] In addition, the two-stage feedstock injection can be carried out for the purpose of improving processability by producing a wide ASD (aggregate size distribution) of carbon black by simultaneously injecting feedstock from two different locations in the discharge portion (115) of the reactor.

[0070] Next, the grit trap system (130) is a primary impurity removal process that first removes relatively large grit. Therefore, in the grit trap system (130), grit exceeding an average diameter of 150 μm is removed.

[0071]

[0072] Table 1 shows the results calculated through computational simulation of the grit trap system, and Fig. 5 is a photograph of the computational simulation of the grit trap system.

[0073]

[0074] [Table 1]

[0075]

[0076] As shown in Table 1 and FIG. 5, the results of the computing simulation of the grit trap system (130) show that the case of Grit 35mesh achieves 100% grit trap, and thus no grit residue exists.

[0077] In this way, it was found that it is desirable to design the grit trap system (130) so that the pipe through which carbon black flows is installed vertically and air is injected into the inside of the pipe to form a vortex to increase the residence time of the carbon black being transported inside the pipe. This design removes grit of a relatively large size in advance before the carbon black is introduced into the low grit system (140) by causing relatively heavy grit impurities to fall in the direction of gravity as the residence time increases and decreases due to the vortex, thereby reducing the overall grit.

[0078]

[0079] Removal of secondary impurities

[0080] In the secondary impurity removal step (S130), the carbon black from which impurities have been removed in the first step is transferred to a low grit system (140) to remove impurities in the carbon black with a relatively small particle size in the second step.

[0081] In this way, in the past, only a low grit system (140) (eACM) was used, but in the present invention, a grit trap system (130) is additionally installed at the front end of the low grit system (140).

[0082] Therefore, in the present invention, by first removing impurities of carbon black having relatively large particle sizes by passing it through a grit trap system (130), and then secondarily removing impurities of carbon black having relatively small particle sizes by passing it through a low grit system (140) mounted at the rear end of the grit trap system (130), the grit can be further reduced.

[0083]

[0084] smash

[0085] In the crushing step (S140), carbon black from which impurities have been removed for the second time is transferred to a crusher (150) and crushed.

[0086] In this step, the grinding can be performed using any one selected from among a hammer mill, a high-speed mixer, a ball mill, and an air jet mill, and among these, grinding using a high-speed rotating hammer mill is preferred. Through this grinding step (S140), the carbon black can be ground into fine powder having an average diameter of 500 μm or less.

[0087]

[0088] Pelletizing and drying

[0089] In the pelletizing and drying step (S150), the crushed material is pelletized and then dried to obtain high-conductivity carbon black powder.

[0090] For this purpose, a pelletizer and a dryer (160) may be sequentially installed at the rear end of the crusher (140).

[0091] In order to facilitate the transport and handling of carbon black, which is a fine powder during pelletizing, it is preferable to add a binder, an emulsion solution, and a solvent to the pulverized powder. In this way, during pelletizing, a binder, an emulsion solution, and a solvent are added together to the pulverized powder, and the powder is granulated into 1 to 2 mm-sized granules through a rotating centrifugal action, thereby pelletizing.

[0092] Thereafter, moisture is evaporated using a heat source and air flow, and the particles of the pulverized material are dried to obtain carbon black particles. During this drying process, it is preferable to dry at 150 to 250°C for 1 to 2 hours to remove moisture (50% → less than 0.5%) within the pulverized material. Furthermore, it is preferable to use a rotating cylinder-type dryer for drying, and the desired moisture content can be obtained by precisely controlling the temperature and time during the drying process.

[0093] The carbon black powder that has completed these pelletizing and drying steps (S150) can be packaged as a final product through a packaging process after exiting the dryer.

[0094] With this, the method for manufacturing high-conductivity carbon black powder according to an embodiment of the present invention can be completed.

[0095]

[0096] The high-conductivity carbon black powder and the method for producing the same according to the embodiment of the present invention described above were produced by changing the diameter of the discharge portion of the reactor to adjust the ratio with the diameter of the quenching portion, and reflecting the operating conditions accordingly.

[0097] In particular, the high-conductivity carbon black powder and the method for producing the same according to an embodiment of the present invention introduce a two-stage feedstock injection method to produce a wide aggregate size distribution (ASD) of carbon black, thereby improving dispersibility and processability without lowering the conductivity of the carbon black powder.

[0098] Previously, only a low grit system (eACM) was used to reduce the grit of carbon black, but the present invention enables the production of carbon black powder with further reduced grit by adding a grit trap system in front of the low grit system.

[0099] To this end, the high-conductivity carbon black powder and the manufacturing method thereof according to the embodiment of the present invention are designed such that a pipe through which carbon black flows is installed vertically, and a grit trap system is designed such that air is injected into the inside of the pipe to form a vortex to increase the residence time of the carbon black being transported inside the pipe. Accordingly, grit impurities having relatively heavy weights fall in the direction of gravity as the residence time increases and decreases due to the vortex, thereby removing grit of relatively large size in advance before the carbon black is introduced into the low-grit system, thereby manufacturing carbon black powder with reduced grit overall.

[0100] As a result, the high-conductivity carbon black powder manufactured by the method according to the embodiment of the present invention not only has excellent electrical conductivity but also excellent processability and dispersibility, and can significantly reduce grit, which is the cause of surface protrusions.

[0101] Therefore, the highly conductive carbon black powder manufactured by the method according to the embodiment of the present invention is suitable for use as a high-voltage wire semiconducting masterbatch and ESD (Electro-Static Discharge) material.

[0102]

[0103] Example

[0104] Hereinafter, the structure and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0105] Anything not described here will be omitted as it is technically feasible for those skilled in this field to infer.

[0106]

[0107] 1. Carbon black manufacturing

[0108] Table 2 shows the manufacturing process and properties of carbon black powder according to Example 1 and Comparative Examples 1 to 2. At this time, the carbon black powder according to Example 1 and Comparative Examples 1 to 2 was manufactured under the process conditions described in Table 1. Comparative Example 1 was produced in a general reactor, and Comparative Example 2 was produced after changing the ratio by changing the throat size of the reactor. In addition, Example 1 was produced by introducing a two-stage feedstock injection method in a state where the ratio was changed by changing the throat size of the reactor.

[0109]

[0110] (1) IA (Iodine Adsorption Number)

[0111] This method analyzes the specific surface area of ​​carbon black based on its iodine adsorption capacity. Measurements were conducted according to ASTM-D1510. The higher the iodine adsorption capacity, the smaller the carbon black particle size. Conversely, the lower the iodine adsorption capacity, the larger the particle size.

[0112]

[0113] (2) OAN (Oil Absorption number)

[0114] The OAN value is an evaluation of the absorption amount of DBP (dibutyl phthalate) that can be contained in 100 g of carbon black, and is measured according to the ASTM-D2414 standard. A higher OAN value indicates a more complex and developed carbon black structure.

[0115]

[0116] (3) Tint

[0117] Measured according to ASTM-D3265. Tint is a value indicating the color of carbon black. A higher tint indicates a smaller particle size and a simpler structure. Conversely, a lower tint indicates a larger particle size and a more complex structure.

[0118]

[0119] (4) Grit

[0120] Measured according to ASTM-D1514. This value is the weight of the unwashed residue in the sieve layer of each mesh when carbon black is placed in 35, 100, and 325 mesh sieves and washed with high-pressure water. Grit is an analysis utilizing the property of not being washed away by water.

[0121]

[0122] [Table 2]

[0123]

[0124]

[0125] 2. Carbon black property evaluation

[0126] Fig. 6 is a graph showing the results of the ASD (aggregate size distribution) analysis of carbon black powders manufactured according to Example 1 and Comparative Examples 1 and 2. At this time, the ASD (aggregate size distribution) analysis method of carbon black is a value that classifies the aggregate of carbon black by size and expresses the distribution in a graph. The analysis was performed using Brookhaven's BI-DCP equipment. After diluting carbon black in a solvent, the time it takes for it to fall to the bottom through centrifugation was converted into AS (aggregate size) and analyzed. At this time, carbon black that falls quickly has a large AS (aggregate size), and carbon black that falls slowly has a small AS (aggregate size).

[0127] As shown in Table 2 and FIG. 6, it was confirmed that the carbon black powder manufactured according to Example 1 had an increased OAN value and a decreased Tint value compared to the carbon black powder manufactured according to Comparative Examples 1 and 2.

[0128] In particular, it was confirmed that the carbon black powder manufactured according to Example 1 had a significantly reduced grit compared to the carbon black powder manufactured according to Comparative Examples 1 and 2.

[0129] In addition, it was confirmed that the carbon black powder manufactured according to Example 1 had a larger AS (aggregate size) of carbon black compared to the carbon black powder manufactured according to Comparative Examples 1 and 2.

[0130]

[0131] 3. Carbon black compound analysis

[0132] Table 3 shows the analysis results of compounds prepared by mixing the carbon black powders manufactured according to Example 1 and Comparative Examples 1 to 2 with a binder resin. At this time, the carbon black compound was prepared by mixing the carbon black powders manufactured according to Example 1 and Comparative Examples 1 to 2 into ethylene vinyl acetate (EVA) resin (Hanwha Total, E-156W) in an amount of 30 wt% and mixing the mixture using an internal mixer (HAAKE Rheocord 90) at 90°C for 15 minutes.

[0133]

[0134] (1) Volume resistance

[0135] Volume resistivity was measured using Mitubishi's MCP-T610. A lower volume resistivity indicates higher electrical conductivity. A compound was prepared by mixing 70 wt% EVA resin with 30 wt% carbon black powder, which was then processed into a 100 mm (width) × 100 mm (length) × 2 mm (height) sheet, and the volume resistivity was measured at room temperature.

[0136]

[0137] (2) Melt index

[0138] The melt flow index (MFI) is a value obtained by measuring the discharge amount of a carbon black compound under the same temperature and pressure. A higher value indicates better processability. The MFI was measured using CEAST's Melt Flow Modular Line equipment. Specifically, a compound was prepared by mixing 70 wt% EVA resin with 30 wt% carbon black, which was then crushed and pelletized. The compound pellets were measured at 190°C for 10 minutes using a 21.6 kg pressure weight.

[0139]

[0140] (3) FPV(Filter pressure value)

[0141] Filter pressure value (FPV) was measured according to EN13900-5. The pressure applied to the filter die was measured by extruding only EVA resin from a carbon black compound device, and the reference pressure was set. Then, the increasing pressure value while extruding the carbon black compound was measured according to Equation 1 below. At this time, a 25㎛ filter was used. The value increases as the dispersibility, processability, and carbon black grit content increase.

[0142] Equation 1: FPV = (P max - P s ) / m

[0143] Here, P max represents the maximum pressure after carbon black powder is added, and P s represents the average pressure value after EVA resin injection, and m represents the amount of carbon black powder added.

[0144]

[0145] [Table 3]

[0146]

[0147] As shown in Table 3, the results of the carbon black compound analysis showed that in the case of Example 1, the volume resistance was lower than that of Comparative Example 1 and showed a value almost similar to that of Comparative Example 2, confirming that the electrical conductivity was hardly reduced.

[0148] In particular, in the case of Example 1, it was confirmed that the melt flow index was significantly increased compared to Comparative Examples 1 and 2, and as a result, it was found that Example 1 exhibited superior processability compared to Comparative Examples 1 and 2.

[0149] In addition, in the case of Example 1, it was confirmed that the FPV (Filter pressure value) was significantly lower than in Comparative Examples 1 and 2, and as a result, it was confirmed that Example 1 had a lower grit content than in Comparative Examples 1 and 2, and thus had superior dispersibility and processability.

[0150]

[0151] 4. Variance Analysis

[0152] Table 4 is a graph showing the results of dispersibility evaluation of carbon black compounds manufactured according to Example 1 and Comparative Examples 1 to 2, and Fig. 7 is a photograph showing the cross-section of carbon black compounds manufactured according to Example 1 and Comparative Examples 1 to 2.

[0153]

[0154] (1) Carbon black dispersibility analysis

[0155] A carbon black compound was prepared by mixing the carbon black powder manufactured according to Example 1 and Comparative Examples 1 and 2 into ethylene vinyl acetate (EVA) resin (Hanwha Total, E-156W) at a content of 30 wt%, mixing the mixture using an internal mixer (HAAKE Rheocord 90) at 90°C for 15 minutes, and then processing the mixture into a 100 mm (width) × 100 mm (length) × 2 mm (height) sheet.

[0156] Afterwards, the cross-section of each sheet was cut and images were taken under a microscope. The undispersed carbon black (black dots) were counted by size and the dispersibility score was determined from 0 to 9.5 rating based on Table 5. A higher number indicates a greater amount of undispersed carbon black, and a lower number indicates better dispersibility. The analysis was conducted in accordance with the ISO 18553 standard.

[0157]

[0158] [Table 4]

[0159]

[0160]

[0161] [Table 5]

[0162]

[0163] As shown in Tables 4 and 5 and FIG. 7, the dispersibility analysis results showed that the carbon black compound manufactured according to Example 1 had a lower rating than the carbon black compounds manufactured according to Comparative Examples 1 and 2. Therefore, it was confirmed that the carbon black compound manufactured according to Example 1 had improved dispersibility than the carbon black compounds manufactured according to Comparative Examples 1 and 2.

[0164]

[0165] 5. Surface protrusion analysis

[0166] Table 6 is a graph showing the results of surface protrusion analysis of carbon black compounds manufactured according to Example 1 and Comparative Examples 1 to 2, and Fig. 8 is a photograph showing the surface of carbon black compounds manufactured according to Example 1 and Comparative Examples 1 to 2.

[0167]

[0168] (1) Surface protrusion measurement

[0169] Carbon black compounds were prepared by mixing 30 wt% of the carbon black powders manufactured according to Example 1 and Comparative Examples 1 and 2 into ethylene vinyl acetate (EVA) resin (Hanwha Total, E-156W) and mixing them using an internal mixer (HAAKE Rheocord 90) at 90°C for 15 minutes. Then, a 2 mm thick sheet was extruded using a single extruder, and the size and number of surface protrusions were measured. The size and number of surface protrusions (black dots on the screen) were measured using self-developed software.

[0170]

[0171] [Table 6]

[0172]

[0173] As shown in Table 6 and Figure 8, the results of the surface protrusion analysis showed that, in the case of the carbon black compound manufactured according to Example 1, both the total number of surface protrusions and the number of surface protrusions of 50 μm or more were reduced compared to the carbon black compounds manufactured according to Comparative Examples 1 and 2.

[0174] In particular, in the case of the carbon black compound manufactured according to Example 1, it was confirmed that the number of surface protrusions of 50㎛ or more, which are known to cause treeing of wires, was significantly reduced.

[0175]

[0176] While the above description focuses on specific embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made. Such modifications and variations, as long as they do not depart from the scope of the technical concept provided by the present invention, are considered to be within the scope of the present invention. Therefore, the scope of the present invention should be determined by the claims set forth below.

[0177]

[0178] [Explanation of symbols]

[0179] S110: Carbon black manufacturing and filtering steps

[0180] S120: 1st impurity removal stage

[0181] S130: Secondary impurity removal stage

[0182] S140: Crushing stage

[0183] S150: Pelletizing and drying stage

Claims

1. (a) A step of manufacturing carbon black in a reactor and then filtering it by passing it through a main bag filter; (b) a step of transporting the filtered carbon black to a grit trap system to first remove impurities of carbon black having relatively large particle sizes; (c) a step of transporting the carbon black from which the above impurities have been first removed to a low grit system to secondarily remove impurities in the carbon black having relatively small particle sizes; (d) a step of transferring the carbon black from which the impurities have been removed for the second time to a crusher and crushing it; and (e) a step of pelletizing the above-mentioned pulverized material and drying it to obtain a high-conductivity carbon black powder; characterized by including, Method for producing high-conductivity carbon black powder.

2. In paragraph 1, In step (a) above, The manufacturing temperature of the above carbon black is Characterized by being carried out under conditions of 1,300 to 1,800℃, Method for producing high-conductivity carbon black powder.

3. In paragraph 1, In step (a) above, The above reactor At least one supply section having an air supply section and a fuel supply section; A reaction section into which high-temperature combustion gas supplied through the above supply section is introduced; A discharge portion (throat) extending from the above reaction portion and formed so as to have a diameter decreasing from the above reaction portion; and A quenching section extending from the discharge section and having a diameter larger than the discharge section; characterized by including, Method for producing high-conductivity carbon black powder.

4. In paragraph 3, The above discharge part and rapid cooling part Characterized in that it is designed to satisfy the following equation 1: Method for producing high-conductivity carbon black powder. Equation 1: 0.36 ≤ (diameter of discharge part / diameter of quenching part) ≤ 0.44 5. In paragraph 3, The above grit trap system Characterized in that it is installed so as to be connected to the discharge portion of the above reactor. Method for producing high-conductivity carbon black powder.

6. In paragraph 5, The above grit trap system The pipe through which the carbon black flows is installed vertically, and air is injected into the inside of the pipe to form a vortex, thereby increasing the residence time of the carbon black transported inside the pipe. Method for producing high-conductivity carbon black powder.

7. In paragraph 3, It is characterized in that the feedstock is supplied in a two-stage feedstock injection method that is connected to the discharge portion of the reactor and injects the feedstock at two different locations of the discharge portion of the reactor. Method for producing high-conductivity carbon black powder.

8. In paragraph 7, The above feedstock two-stage injection method It is initially supplied at a speed of 300 to 600 kg / hour using a feedstock nozzle, It is characterized by supplying secondarily at a speed of 1,000 to 2,000 kg / hour using a feedstock nozzle. Method for producing high-conductivity carbon black powder.

9. In paragraph 8, When supplying for the first time using the above feedstock nozzle, 20 to 25 wt% of the total 100 wt% is supplied, In the secondary supply using the above feedstock nozzle, it is characterized in that 75 to 80 wt% of the total 100 wt% is supplied. Method for producing high-conductivity carbon black powder.

10. In paragraph 6, The above feedstock 2-stage injection It is characterized in that it is connected to the discharge part of the above reactor and simultaneously injects the feedstock from two different locations of the discharge part of the above reactor. Method for producing high-conductivity carbon black powder.

11. In clause 9 or 10, In the above grit trap system, Characterized in that grit exceeding an average diameter of 150㎛ is removed. Method for producing high-conductivity carbon black powder.

12. In paragraph 1, In step (d) above, The above grinding characterized by using one selected from among a hammer mill, a high-speed mixer, a ball mill and an air jet mill. Method for producing high-conductivity carbon black powder.

13. A carbon black powder manufactured by a method for manufacturing a high-conductivity carbon black powder according to any one of claims 1 to 12, The above carbon black powder is characterized in that it has grit having an average diameter of 50 to 150㎛ and is less than 10 ppm. High conductivity carbon black powder.

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