High-quality carbon black powder for rubber composite additive and rubber composite comprising same

Abstract

Disclosed are high-quality carbon black powder for a rubber composite additive and a rubber composite comprising same, wherein the high-quality carbon black powder increases the specific surface area by steam activation treatment of recycled carbon black recovered in a waste tire pyrolysis process through a steam activation treatment process, and improves physical properties such as mechanical strength, abrasion resistance, and durability by utilizing the steam-activated recycled carbon black with an increased specific surface area as an additive for a rubber composite.

Description

High-quality carbon black powder for rubber composite additives and rubber composites containing the same

[0001] The present invention relates to a high-quality carbon black powder for use as a rubber composite additive and a rubber composite containing the same. More specifically, the invention relates to a high-quality carbon black powder for use as a rubber composite additive and a rubber composite containing the same, wherein the specific surface area of ​​recycled carbon black recovered from a waste tire pyrolysis process is increased by steam activation treatment through a steam activation treatment process, and the steam-activated recycled carbon black with an increased specific surface area is utilized as an additive to the rubber composite, thereby improving physical properties such as mechanical strength, wear resistance, and durability.

[0002]

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

[0004] Carbon black influences the quality of materials used based on its inherent physical properties, which include crystallinity, specific surface area, structure, and particle size. These properties can be controlled through various post-treatments. Carbon black is used in diverse fields, such as industrial additives, industrial paints, coating compositions, and various printed materials.

[0005] In particular, carbon black used in the manufacture of tires is an essential additive that increases the bonding strength of rubber, the main component of tires, and requires a purity of over 99%. In addition, pyrolysis is widely used as a method to recover carbon black from waste tires.

[0006] As such, research is being conducted on carbon black recycling methods to establish a circular economy for waste tires. Recovered carbon black (rCB) is a product made by processing char obtained after the pyrolysis of waste tires, and is currently used by tire companies as a simple input during the manufacture of some tire compounds at a content ratio of about 1 to 5 wt%.

[0007] Recently, with the increasing demand for the use of sustainable materials and compliance with ESG regulations, the use of recovered carbon black (rCB), obtained from the pyrolysis of waste tires, is gradually expanding. However, conventional recovered carbon black has limitations in meeting the requirements of high-performance rubber composites due to its low specific surface area and activity. In particular, the low specific surface area and activity of recovered carbon black lead to reduced bonding strength in rubber composites, which can consequently result in a degradation of physical properties. Accordingly, post-processing technologies are required to enhance the performance of recovered carbon black.

[0008]

[0009] Based on the aforementioned technical problems, the present invention aims to provide a high-quality carbon black powder for use as a rubber composite additive and a rubber composite containing the same, wherein physical properties such as mechanical strength, wear resistance, and durability are improved by increasing the specific surface area of ​​recycled carbon black recovered from a waste tire pyrolysis process through a steam activation treatment process and utilizing the steam-activated recycled carbon black with an increased specific surface area as an additive to the rubber composite.

[0010]

[0011] A high-quality carbon black powder for a rubber composite additive according to an embodiment of the present invention for achieving the above objective comprises 5 to 25 weight% of steam-activated recycled carbon black powder; and 75 to 95 weight% of ordinary carbon black; wherein the steam-activated recycled carbon black powder is characterized by having an increased specific surface area.

[0012] The steam-activated recycled carbon black powder contains a content ratio of 5 to 15 weight percent.

[0013] The above steam-activated regenerated carbon black powder has an IA value of 100 to 550 g / kg, an N2SA value of 100 to 380 m² / g, an OAN value of 100 to 200 ml / 100g, and a Tint value of 45 to 55% ITRB.

[0014]

[0015] A rubber composite according to an embodiment of the present invention for achieving the above objective is a rubber composite comprising a high-quality carbon black powder for rubber composite additives, wherein the high-quality carbon black powder comprises 5 to 25 weight% of steam-activated recycled carbon black powder; and 75 to 95 weight% of ordinary carbon black; and wherein the steam-activated recycled carbon black powder is characterized by having an increased specific surface area.

[0016] The above high-quality carbon black powder has an IA value of 40 to 130 g / kg, an N2SA value of 40 to 130 m² / g, an OAN value of 90 to 130 ml / 100g, and a Tint value of 40 to 60% ITRB.

[0017] The above rubber composite comprises the high-quality carbon black powder and the rubber composition, and the high-quality carbon black powder comprises 1 to 30 parts by weight per 100 parts by weight of the rubber composition.

[0018] The above rubber composite has a tensile strength (TB) of 221 to 230 kgf / ㎠, a tensile modulus (M300) of 104 to 110 kgf / ㎠, and an elongation (EB) of 500 to 520%.

[0019]

[0020] The high-quality carbon black powder for rubber composite additives according to the present invention and the rubber composite containing the same improve the specific surface area and structural characteristics of recycled carbon black (rCB) through steam activation treatment, thereby enabling the steam-activated recycled carbon black to exhibit stronger performance within the rubber composite than simple recycled carbon black that has not undergone steam activation treatment.

[0021] In addition, the high-quality carbon black powder for rubber composite additives according to the present invention and the rubber composite containing the same enhance the interaction between the regenerated carbon black (rCB) and the rubber composition through steam activation treatment, thereby significantly improving the dispersibility and bonding strength of the regenerated carbon black within the rubber composite. Consequently, the mechanical properties of the rubber composite, such as tensile strength (TB), tensile modulus (M300), and elongation (EB), are significantly improved.

[0022] In particular, the high-quality carbon black powder for rubber composite additives according to the present invention and the rubber composite containing the same can achieve optimal performance of the rubber composite by mixing steam-activated recycled carbon black with commercial carbon black through variable input of 5 to 25 weight percent, thereby enhancing the wear resistance and durability required for high-durability products such as tires. As a result, it contributes to increasing the wear resistance of the rubber composite, providing an economical and environmentally friendly alternative for tires and industrial rubber products. Therefore, the steam-activated recycled carbon black of the present invention exhibits significant technical effects that enable the simultaneous realization of resource recycling and cost reduction through these characteristics.

[0023] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below.

[0024]

[0025] FIG. 1 is a process flowchart showing a method for manufacturing high-quality carbon black powder for rubber composite additives according to an embodiment of the present invention.

[0026]

[0027] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0028] Details not described in this specification that can be sufficiently technically inferred by a person skilled in the art are to be omitted.

[0029] In this specification, the statement that any component is disposed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any component is disposed in contact with the upper (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.

[0030] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "contains," "has," or "includes" should not be interpreted as necessarily including all of the various components described in the specification, and should be interpreted as meaning that some of the components may not be included or that additional components may be included.

[0031] The following is a detailed description of a high-quality carbon black powder for rubber composite additives and a rubber composite containing the same according to a preferred embodiment of the present invention, with reference to the attached drawings.

[0032]

[0033] A high-quality carbon black powder for a rubber composite additive according to an embodiment of the present invention comprises 5 to 25 weight% of steam-activated recycled carbon black powder; and 75 to 95 weight% of ordinary carbon black. More preferably, the steam-activated recycled carbon black powder comprises a content ratio of 5 to 15 weight%.

[0034] If the steam-activated recycled carbon black powder is included in a content ratio of less than 5 weight% with respect to 100 weight% of the total steam-activated recycled carbon black powder and ordinary carbon black, the amount of recycled carbon black powder added is too small, so the recycled carbon black powder is not sufficiently recycled, which may result in a lack of economic feasibility. Conversely, if the steam-activated recycled carbon black powder is included in a content ratio exceeding 25 weight% with respect to 100 weight% of the total steam-activated recycled carbon black powder and ordinary carbon black, it is undesirable because it may act as a factor that degrades the physical properties of the rubber composite when added to the rubber composition and applied to the rubber composite.

[0035] In this way, high-quality carbon black powder obtained by mixing steam-activated recycled carbon black powder with ordinary carbon black powder is used as an additive to rubber composites, which can significantly improve key physical properties such as mechanical strength, wear resistance, and durability of the rubber composites.

[0036] Here, steam-activated recycled carbon black powder is used in which the specific surface area has been increased by steam activation treatment in a reactor under a nitrogen atmosphere.

[0037] It is preferable to use steam-activated recycled carbon black powder that has undergone steam activation treatment by supplying steam at a rate of 10 to 1,000 ml / min in a reactor under a nitrogen atmosphere.

[0038] In addition, it is preferable to use steam-activated recycled carbon black powder that has been steam-activated at 900 to 1,000°C for 1 to 9 hours. More preferably, the steam activation treatment should be performed at 900 to 1,000°C for 2 to 6 hours, and most preferably, the steam activation treatment should be performed at 900 to 1,000°C for 2 to 4 hours. If the steam activation treatment temperature is below 900°C or the steam activation treatment time is less than 1 hour, the activation treatment is not properly performed, and the effect of increasing the specific surface area of ​​the recycled carbon black (rCB) may be negligible. Conversely, if the steam activation treatment temperature exceeds 1,000°C or the steam activation treatment time exceeds 9 hours, additional improvement in physical properties is possible, but it is not desirable because the longer process time leads to increased energy consumption and costs, and the effect of performance improvement is limited.

[0039] Accordingly, in the present invention, it was confirmed through experiments that maintaining the steam activation treatment at 900 to 1,000°C for 2 to 4 hours is a condition that can optimize the economic efficiency and physical properties of recycled carbon black (rCB). As such, in the present invention, by thoroughly controlling the steam activation treatment temperature, time, and steam injection amount, it is possible to produce high-quality recycled carbon black (rCB) with an increased specific surface area.

[0040] As a result, the steam-activated recycled carbon black powder has an IA value of 100 to 550 g / kg and an N2SA value of 100 to 380 m² / g.

[0041] In addition, steam-activated regenerated carbon black powder has an OAN value of 100 to 200 ml / 100g and a Tint value of 45 to 55% ITRB.

[0042] In this way, the high-quality carbon black powder for rubber composite additives according to the embodiment of the present invention increases the specific surface area by steam-activating recycled carbon black recovered from a waste tire pyrolysis process through a steam activation treatment process, and by utilizing the steam-activated recycled carbon black with an increased specific surface area as an additive to the rubber composite, it is possible to improve physical properties such as mechanical strength, wear resistance, and durability of the rubber composite.

[0043]

[0044] Meanwhile, the rubber composite comprising high-quality carbon black powder according to an embodiment of the present invention is a rubber composite comprising high-quality carbon black powder for use as a rubber composite additive, wherein the high-quality carbon black powder comprises 5 to 25 weight% of steam-activated recycled carbon black powder; and 75 to 95 weight% of ordinary carbon black. More preferably, the steam-activated recycled carbon black powder is preferably included in a content ratio of 5 to 15 weight%.

[0045] Here, steam-activated recycled carbon black powder is used in which the specific surface area has been increased by steam activation treatment in a reactor under a nitrogen atmosphere.

[0046] It is preferable to use steam-activated recycled carbon black powder that has undergone steam activation treatment by supplying steam at a rate of 10 to 1,000 ml / min in a reactor under a nitrogen atmosphere.

[0047] As a result, steam-activated recycled carbon black powder is added at 5 to 25 weight percent of the total weight of high-quality carbon black powder, having an IA value of 40 to 130 g / kg and an N2SA value of 40 to 130 m² / g.

[0048] In addition, steam-activated recycled carbon black powder is added at 5 to 25 weight percent of the total weight of high-quality carbon black powder, having an OAN value of 90 to 130 ml / 100g and a Tint value of 40 to 60% ITRB.

[0049] In addition, a rubber composite containing high-quality carbon black powder according to an embodiment of the present invention comprises high-quality carbon black powder and a rubber composition, wherein the high-quality carbon black powder comprises 1 to 30 parts by weight per 100 parts by weight of the rubber composition.

[0050] Here, if high-quality carbon black powder is added in an amount of less than 1 part by weight per 100 parts by weight of the rubber composition, the effect of improving mechanical properties such as tensile strength (TB), tensile modulus (M300), and elongation (EB) of the rubber composite may be negligible. Conversely, if high-quality carbon black powder is added in excess of 30 parts by weight per 100 parts by weight of the rubber composition, the viscosity increases, which increases energy consumption during the mixing process with the rubber composition and may have a somewhat adverse effect on processability, so it is not desirable.

[0051] In order to optimize the bonding strength with the rubber composition by considering the specific surface area characteristics of steam-activated recycled carbon black, it is desirable to apply a method of maintaining conditions of a low temperature of 130°C or lower and a low mixing speed of 40 to 60 RPM during the mixing process between the rubber composition and high-quality carbon black powder.

[0052] A rubber composite containing high-quality carbon black powder according to an embodiment of the present invention has a tensile strength (TB) of 210 to 230 kgf / ㎠, a tensile modulus (M300) of 100 to 110 kgf / ㎠, and an elongation (EB) of 500 to 520%.

[0053]

[0054] As described above, the high-quality carbon black powder for rubber composite additives according to the embodiments of the present invention and the rubber composite containing the same can be added to a rubber composition used in tire manufacturing to improve key physical properties such as mechanical strength, wear resistance, and durability of the rubber composite. Furthermore, by using steam-activated recycled carbon black mixed with general carbon black at an optimal mixing ratio, it becomes possible to manufacture a rubber composite with excellent key physical properties such as mechanical strength, wear resistance, and durability in an eco-friendly and economical manner.

[0055] In this way, the high-quality carbon black powder for rubber composite additives according to the embodiment of the present invention and the rubber composite containing the same effectively increase the specific surface area of ​​recycled carbon black recovered by the pyrolysis process of waste tires using steam activation treatment technology, and by mixing the recycled carbon black with the increased specific surface area with the rubber composition to further strengthen the interaction with the rubber composition, the physical properties of the rubber composite can be significantly improved.

[0056] In particular, the high-quality carbon black powder for rubber composite additives and the rubber composite containing it according to the embodiment of the present invention utilize a method of mixing steam-activated recycled carbon black with general carbon black (N660). Conventionally, it was common to apply recycled carbon black to rubber composites at a low ratio of approximately 5 weight percent; however, as a result of improving performance through the steam activation process, the application ratio of recycled carbon black can be expanded to 5 to 25 weight percent. This variable input method allows for flexible adjustment of the amount of recycled carbon black used, thereby enabling an optimized formulation design according to the performance requirements of the rubber composite.

[0057] Furthermore, the high-quality carbon black powder for rubber composite additives and the rubber composite containing the same according to the embodiment of the present invention applied a method of maintaining low temperature of 130°C or lower and low RPM conditions during the compounding process to optimize the bonding strength with the rubber composition by considering the specific surface area characteristics of steam-activated recycled carbon black. Through this, the reduction in the specific surface area of ​​steam-activated recycled carbon black (rCB) is minimized, enabling uniform dispersion of steam-activated recycled carbon black (rCB) within the rubber composite, and as a result, the mechanical performance and durability of the rubber composite can be further improved.

[0058] Accordingly, the high-quality carbon black powder for rubber composite additives and the rubber composite containing the same, according to an embodiment of the present invention, can significantly improve key physical properties such as mechanical strength, wear resistance, and durability of the rubber composite along with the economical utilization of recycled carbon black, thereby providing a technical basis for simultaneously securing eco-friendliness and economic efficiency in various rubber products, including tire manufacturing.

[0059]

[0060] Hereinafter, a method for manufacturing high-quality carbon black powder for rubber composite additives according to an embodiment of the present invention will be described with reference to the attached drawings.

[0061] FIG. 1 is a process flowchart showing a method for manufacturing high-quality carbon black powder for rubber composite additives according to an embodiment of the present invention.

[0062] Referring to FIG. 1, a method for manufacturing high-quality carbon black powder for rubber composite additives according to an embodiment of the present invention includes a regenerated carbon black transfer step (S110), a steam activation treatment step (S120), a regenerated carbon black powder obtaining step (S130), and a step of mixing the regenerated carbon black powder and ordinary carbon black powder (S140).

[0063]

[0064] Recycled carbon black transfer

[0065] In the recycled carbon black transfer step (S110), the recycled carbon black recovered by the pyrolysis process of waste tires is transferred to a reactor in a nitrogen atmosphere.

[0066] In the present invention, the term recycled carbon black may be referred to as recovered carbon black, recycle carbon black, recycled CB, RCB, rCB, and r-CB, respectively, and these are all defined as corresponding to synonyms.

[0067] In this way, in the recycled carbon black transfer step (S110), the recycled carbon black recovered by the pyrolysis process of waste tires is transferred into the reactor of a steam activation treatment device maintained in a nitrogen atmosphere for steam activation treatment. At this time, it is desirable to maintain a clean state so that impurities that may occur during the process do not enter the reactor of the steam activation device.

[0068] Here, creating a nitrogen atmosphere inside the reactor of the steam activation treatment device is intended to control the process so that oxidation reactions do not occur at high temperatures by removing oxygen.

[0069]

[0070] Steam activation processing

[0071] In the steam activation treatment step (S120), steam activation treatment is performed on the regenerated carbon black transferred to a reactor in a nitrogen atmosphere to increase the specific surface area of ​​the regenerated carbon black.

[0072] This steam activation treatment process is carried out for the purpose of improving the specific surface area and structural characteristics of recycled carbon black (rCB) to enhance the physical properties of the rubber composite through mixing with the rubber composition.

[0073] In this step, it is preferable to perform the steam activation treatment at 900 to 1,000°C for 1 to 10 hours. More preferably, it is preferable to perform the steam activation treatment at 900 to 1,000°C for 2 to 4 hours.

[0074] In this way, the steam activation treatment is performed by heating the inside of the reactor of the steam activation treatment device to 900 to 1,000°C and maintaining a high temperature state, and then reacting the regenerated carbon black (rCB) with steam for 1 to 9 hours to activate it.

[0075] At this time, the steam injected into the reactor of the steam activation treatment device acts as an activator to expand the pores on the surface of the regenerated carbon black (rCB) and increase the specific surface area. To this end, during the steam activation treatment, it is desirable to supply steam at a rate of 10 to 1,000 ml / min into the reactor under a nitrogen atmosphere.

[0076] Here, if the steam activation treatment temperature is below 900°C or the steam activation treatment time is less than 1 hour, the activation treatment is not properly performed, and the effect of increasing the specific surface area of ​​the regenerated carbon black (rCB) may be negligible. Conversely, if the steam activation treatment temperature exceeds 1,000°C or the steam activation treatment time exceeds 10 hours, additional improvement in physical properties is possible, but it is not desirable because the longer the process time, the higher the energy consumption and cost, and the limited effect of performance improvement.

[0077] Accordingly, in the present invention, it was confirmed through experiments that maintaining the steam activation treatment at 900 to 1,000°C for 2 to 6 hours is a condition that can optimize the economic efficiency and physical properties of regenerated carbon black (rCB). As such, in the present invention, high-quality regenerated carbon black (rCB) with an increased specific surface area was produced by thoroughly controlling the steam activation treatment temperature, time, and steam injection amount.

[0078]

[0079] Obtaining recycled carbon black powder

[0080] In the step of obtaining regenerated carbon black powder (S130), the steam-activated regenerated carbon black is cooled, then dried and ground to obtain steam-activated regenerated carbon black powder.

[0081] In this step, the steam-activated regenerated carbon black passes through a cooling section to maintain its activated state and prevent damage to the micropore structure. At this time, cooling may be performed by air cooling or water cooling, but is not limited thereto.

[0082] Subsequently, the cooled regenerated carbon black passes through a drying section to be dried, and then is ground to optimize particle size and distribution. This drying can be performed by residence drying at 150 to 250°C for 1 to 6 hours, but is not limited thereto. At this time, a rotary cylinder type dryer may be used for drying.

[0083] In addition, grinding can be performed using any one selected from a hammer mill, a high-speed mixer, a ball mill, and an air jet mill, and among these, it is preferable to grind using a high-speed rotating hammer mill. After such grinding, the steam-activated regenerated carbon black can be ground into a fine powder having an average diameter of 500 μm or less.

[0084] In this step, the steam-activated recycled carbon black powder has an IA value of 100 to 550 g / kg and an N2SA value of 100 to 380 m² / g.

[0085] In addition, steam-activated regenerated carbon black powder has an OAN value of 100 to 200 ml / 100g and a Tint value of 45 to 55% ITRB.

[0086]

[0087] Mixture of recycled carbon black powder and regular carbon black powder

[0088] In the step of mixing regenerated carbon black powder and ordinary carbon black powder (S140), the steam-activated regenerated carbon black powder is mixed with ordinary carbon black powder.

[0089] In this step, it is preferable to mix steam-activated recycled carbon black powder in a ratio of 5 to 25 weight% and ordinary carbon black in a ratio of 75 to 95 weight%. More preferably, it is better to mix the steam-activated recycled carbon black powder in a ratio of 5 to 15 weight%.

[0090] When steam-activated recycled carbon black powder is mixed with a content ratio of less than 5% by weight relative to 100% by weight of the total steam-activated recycled carbon black powder and ordinary carbon black, the amount of recycled carbon black powder added is too small, so the recycled carbon black powder is not sufficiently recycled, which may result in a lack of economic feasibility. Conversely, when steam-activated recycled carbon black powder is mixed with a content ratio exceeding 25% by weight relative to 100% by weight of the total steam-activated recycled carbon black powder and ordinary carbon black, it is undesirable because it may act as a factor that degrades the physical properties of the rubber composite when added to the rubber composition and applied to the rubber composite.

[0091] In this way, high-quality carbon black powder obtained by mixing steam-activated recycled carbon black powder with ordinary carbon black powder is used as an additive to rubber composites, which can significantly improve key physical properties such as mechanical strength, wear resistance, and durability of the rubber composites.

[0092] With this, the method for manufacturing high-quality carbon black powder for rubber composite additives according to an embodiment of the present invention may be concluded.

[0093]

[0094] Examples

[0095] Hereinafter, the structure and operation of the present invention will be explained 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 interpreted in any way as limiting the present invention.

[0096] Details not listed here can be sufficiently technically inferred by a person skilled in this field, so their explanation will be omitted.

[0097]

[0098] 1. Physical properties of recycled carbon black

[0099] Table 1 shows the results of the evaluation of physical properties of recycled carbon black according to the steam activation treatment time. At this time, to evaluate the physical properties of recycled carbon black according to the steam activation treatment time, recycled carbon black recovered from a waste tire pyrolysis process was subjected to steam activation treatment at a high temperature of 950°C under a nitrogen atmosphere for 0 hours (Comparative Example 1), 3 hours (Example 1), 6 hours (Example 2), and 10 hours (Comparative Example 2), respectively.

[0100]

[0101] (1) IA (Iodine Adsorption Number)

[0102] This is a method for analyzing the specific surface area of ​​carbon black based on the amount of iodine adsorbed. It was measured according to ASTM-D1510 standards. The higher the amount of iodine adsorbed, the smaller the particle size of the carbon black becomes, and conversely, the lower the amount of iodine adsorbed, the larger the particle size becomes.

[0103]

[0104] (2) N2SA (Nitrogen Surface Area, BET, ㎡ / g)

[0105] N2SA is a value representing the specific surface area of ​​carbon black measured using nitrogen gas in accordance with ASTM D-6556 standards. It is expressed in units of m² / g by measuring the area where nitrogen is adsorbed onto the carbon black surface through BET analysis. A higher BET surface area indicates smaller carbon black particle sizes and a larger surface area.

[0106]

[0107] (3) OAN (Oil Absorption number)

[0108] The OAN value is a value representing the amount of DBP (Dibutyl phthalate) oil absorbed that can be contained in 100g of carbon black. OAN was measured according to the analysis method based on ASTM D2414 (measuring the amount of dibutyl phthalate oil adsorbed in 100g of carbon black (ml / 100g)). A higher OAN value indicates that the carbon black structure is more complex and developed.

[0109]

[0110] (4)COAN (Compressed Oil Absorption Number, ㎖ / 100g)

[0111] COAN is a value that measures the amount of oil carbon black can absorb under compressed conditions according to ASTM D-3493, and represents the bonding strength between particles. It measures the amount of oil absorbed per 100g of carbon black under compressed conditions and generally has a lower value than OAN.

[0112]

[0113] (5) Tint

[0114] Tint was measured according to ASTM-D3265 standards. As a value (% ITRB) representing the color of carbon black, a higher tint value indicates that the carbon black has a smaller particle size and a simpler structure. Conversely, a lower tint value indicates that the carbon black has a larger particle size and a more complex structure.

[0115]

[0116] [Table 1]

[0117]

[0118] As shown in Table 1, it was confirmed that when steam activation treatment was not performed on the regenerated carbon black as in Comparative Example 1, the IA value (Iodine Adsorption), specific surface area (N2SA), and oil absorption amount (OAN) did not satisfy the target values ​​of 100 to 550 g / kg IA value, 100 to 380 m² / g N2SA value, 100 to 200 ml / 100g OAN value, and 45 to 55% Tint value.

[0119] On the other hand, as in Manufacturing Examples 1 and 2 and Manufacturing Comparative Example 2, it was confirmed that the IA value (Iodine Adsorption), specific surface area (N2SA), and oil absorption amount (OAN) of the regenerated carbon black gradually increased as the steam activation treatment time for the regenerated carbon black increased.

[0120] However, as in Manufacturing Comparative Example 2, it was confirmed that when the steam activation treatment time for the recycled carbon black is excessively performed for 10 hours, the IA value, OAN value, and Tint value deviate from the target values.

[0121] As a result, it was determined that when recycled carbon black with an increased specific surface area through optimal steam activation treatment, as in Manufacturing Examples 1 and 2, is applied as an additive to a rubber composite, the bonding strength with the rubber composition is increased, which can contribute to the improvement of key physical properties such as wear resistance, heat resistance, and mechanical strength.

[0122] As can be seen from the experimental results above, the physical properties of recycled carbon black, such as IA and N2SA values, are improved depending on whether steam activation treatment is performed or not. In particular, after 2 hours of steam activation treatment on the recycled carbon black, the IA and N2SA values ​​satisfy the target values, confirming that the carbon black powder has physical properties suitable for use in special tires such as racing cars, rather than general vehicle tires.

[0123]

[0124] 2. Physical properties of variable input mixtures of steam-activated recycled carbon black

[0125] Table 2 shows the blending amount of steam-activated recycled carbon black and the optimal process conditions to maximize the properties of the rubber composite. The blending conditions described here are optimal conditions to maximize the properties of the rubber composite while preserving the properties of the steam-activated recycled carbon black (rCB).

[0126]

[0127] [Table 2]

[0128]

[0129] The properties of the variable input blend of recycled carbon black prepared according to steam activation treatment time were evaluated by applying the blending conditions listed in Table 2 above. At this time, the blending evaluation was conducted by applying the recycled carbon black (rCB), which was steam-activated for 0, 3, 6, and 10 hours, in variable amounts of 5 wt%, 10 wt%, 15 wt%, 25 wt%, and 30 wt% based on 50 phr of general carbon black (nCB: N660).

[0130] Through this, the correlation between changes in the physical properties of rubber composites and the inclusion of high-quality carbon black powder, prepared according to the mixing ratios of recycled carbon black (rCB) and general carbon black (nCB) for different steam activation treatment times, as an additive in rubber composites was confirmed, and the potential for their application in tires and rubber products was examined.

[0131]

[0132] 3. Evaluation of Rubber Composite Properties

[0133] Table 3 shows the results of the physical property evaluation of the rubber composite according to Comparative Example 1, Table 4 shows the results of the physical property evaluation of the rubber composite according to Example 1, Table 5 shows the results of the physical property evaluation of the rubber composite according to Example 2, and Table 6 shows the results of the physical property evaluation of the rubber composite according to Comparative Example 2. More specifically, Comparative Example 1 shows the results of the physical property evaluation of the rubber composite according to the mixing ratio of recycled carbon black (Manufacturing Comparative Example 1) and general carbon black (nCB: N660) before steam activation treatment (0 hours), and Example 1 shows the results of the physical property evaluation of the rubber composite according to the mixing ratio of recycled carbon black (Manufacturing Example 1) and general carbon black (nCB: N660) after 3 hours of steam activation treatment. In addition, Example 2 shows the results of evaluating the physical properties of a rubber composite according to the mixing ratio of regenerated carbon black (Manufacturing Example 2) and general carbon black (nCB: N660) after 6 hours of steam activation treatment, and Comparative Example 2 shows the results of evaluating the physical properties of a rubber composite according to the mixing ratio of regenerated carbon black (Manufacturing Comparative Example 2) and general carbon black (N660) after 10 hours of steam activation treatment. Here, the rubber composite was prepared by adding carbon black powder, zinc oxide, stearic acid, TDAE (Treated Distillate Aromatic Extracted) oil, and 6PPD and RD (2,2,4-Trimethyl-1,2-dihydroquinoline (TMQ)) as additives to raw rubber, respectively, and then stirring at 150°C for 5 minutes to prepare a master batch. Next, a master batch prepared by adding S (Sulfur) and NS (rubber vulcanization accelerator, TBBS) and stirring at 110°C for 2 minutes was used.

[0134]

[0135] (1) Mooney viscosity (ML1+4, 100℃)

[0136] Mooney viscosity (MV) was measured for each rubber composite according to ASTM D 1646: RUBBER FROM NATURAL OR SYNTHETIC SOURCES-VISCOSITY AND VULCANIZATION CHARACTERISTICS (MOONEY VISCOMETER). 50-ML1+4(100℃), where 50-M is the viscosity number, L indicates the use of a large rotor, 1 means the motor was preheated for 1 minute before operation, 4 means the specified measurement time, and 100℃ means the measurement temperature. A higher Mooney viscosity indicates poorer dispersibility of the components within the rubber composition. Mooney viscosity was measured at 50-ML1+4 (100°C) for each rubber composition according to ASTM D 1646. This measurement reflects the dispersibility of each component, and the MV value (Mooney unit, MU) increases as the activation time increases. This was determined to be because the interaction with the rubber composition was strengthened as the specific surface area and structure of the recycled carbon black (rCB) changed due to the steam activation treatment.

[0137]

[0138] (2) Vulcanization properties

[0139] Hardness was measured according to ASTM D-2240, and tensile stress (tensile modulus, M300), elongation break (EB), and tensile strength (Tensile break, TB) were measured according to ASTM 412-98a.

[0140]

[0141] [Table 3]

[0142]

[0143]

[0144] [Table 4]

[0145]

[0146]

[0147] [Table 5]

[0148]

[0149]

[0150] [Table 6]

[0151]

[0152] As shown in Tables 2 to 6, for the rubber composites according to Examples 1 and 2 and Comparative Example 2, as the mixing ratio of recycled carbon black increases to 5 to 30 wt%, the specific surface area (N2SA) and IA value (Iodine Adsorption) of the carbon black increase, thereby increasing the contact surface with the rubber composition, and as a result, the physical bonding force between the rubber composite and the carbon black powder is strengthened. This causes the rubber composite to become harder.

[0153] In addition, in the case of the rubber composites according to Examples 1 and 2 and Comparative Example 2, as the oil absorption amount (OAN) increases, the internal structure and pores of the carbon black powder become more complex, and the interaction with the rubber composition increases. This structure tends to result in the carbon black powder being more uniformly dispersed within the rubber composition, and the density of the rubber composite increasing, leading to a higher hardness.

[0154] In addition, for the rubber composites according to Examples 1 and 2 and Comparative Example 2, the tensile stress (tensile modulus, M300) and elongation break (EB) are increased as the specific surface area and structural properties of the regenerated carbon black change with longer steam activation treatment times, thereby strengthening the bonding force with the rubber composition. As a result, the carbon black powder within the rubber composite bonds more strongly with the rubber molecules, increasing the resistance of the rubber. Consequently, the tensile stress (tensile modulus, M300) required to stretch the rubber by 300% increases.

[0155] However, if a large amount of recycled carbon black (rCB) is added to general carbon black (nCB) at a blending ratio exceeding 25 wt%, the stress dispersion ability within the compound decreases, resulting in a decrease in tensile stress (tensile modulus, M300). This is because excessive carbon black dispersion causes aggregation, disrupting the flexibility and balance of the rubber composite. Conversely, as the tensile stress (tensile modulus, M300) value increases, the strength of the polymer composite increases, but flexibility decreases, leading to a lower elongation break (EB) value. When the tensile stress (tensile modulus, M300) value begins to decrease, flexibility recovers, and the elongation break (EB) value tends to rise.

[0156] In the case of the rubber composites of Examples 1 and 2 and Comparative Example 2, the tensile strength (Tensile break, TB) decreased as the surface area (N2SA) and oil absorption amount (OAN) of the recycled carbon black powder increased with increasing steam activation treatment time. However, beyond a certain level, as the content of the steam-activated recycled carbon black increased, it was not uniformly dispersed within the rubber, and stress concentration occurred in specific areas. Additionally, as the steam activation treatment time increased, physical property values ​​of the rubber composite, such as Mooney Viscosity (MV), also increased. Since rubber flow tended to decrease when the Mooney Viscosity (MV) value increased by more than 10% compared to general carbon black, a higher Mooney Viscosity (MV) value is disadvantageous in terms of processability. Accordingly, in the case of the rubber composite according to Comparative Example 2, when the content of recycled carbon black (rCB) is added at 30 wt% (Comparative Example 2-5), which exceeds 25 wt%, the Mooney viscosity (MV) value is more than 25% higher than that of general carbon black, so uniform dispersion within the rubber composite is not achieved, resulting in a decrease in the tensile modulus (M300), and it was confirmed that the processability and tensile stress of the rubber composite tend to decrease.

[0157] In addition, it was confirmed that in the case of the rubber composite according to Comparative Example 1, key physical properties such as tensile strength (TB) and tensile modulus (M300) fell short of the target values.

[0158]

[0159] 4. Conclusion

[0160] As a result of measuring the physical properties of high-quality carbon black powder according to steam activation treatment, the physical properties of carbon black that affect rubber properties such as IA and OAN changed when recycled carbon black was simply added according to 5 to 25 wt% formulations.

[0161] In addition, the results of the analysis of the physical properties of the rubber composite also showed that as the proportion of recycled carbon black increased from 5 to 25 wt%, the level of degradation in tensile properties compared to general carbon black increased. Through this, it was confirmed that it is desirable to add recycled carbon black (rCB) at 25 wt% or less when simply mixing general carbon black (nCB) and recycled carbon black (rCB).

[0162] In particular, in the case of the rubber composites according to Examples 1 and 2 and Comparative Example 2 using recycled carbon black (rCB) that was steam-activated for 3, 6, and 10 hours, the main physical properties such as hardness, tensile strength (TB), and tensile modulus (M300) were generally increased compared to Comparative Example 1, which used recycled carbon black (rCB) that was not steam-activated.

[0163] However, in the rubber composites according to Examples 1 and 2 and Comparative Example 2 using steam-activated recycled carbon black (rCB), there were cases where the Mooney viscosity (MV) value increased by more than 10% compared to general carbon black as the content of recycled carbon black (rCB) increased. While this increase in Mooney viscosity (MV) value indicates that the interaction between recycled carbon black (rCB) and rubber within the rubber composite has been strengthened, it may have a somewhat adverse effect on processability due to the uniform dispersion within the rubber composite. In particular, if the Mooney viscosity (MV) value increases by more than 20% compared to general carbon black, energy consumption during the rubber mixing process increases, and processing may become difficult. Therefore, a high increase in Mooney viscosity (MV) value may result in increased strength of the rubber composite due to increased bonding strength between the rubber and carbon black, but may lead to a somewhat reduced processability.

[0164] In terms of rubber processability, when the steam activation treatment time was 10 hours or more (Comparative Example 2), the variability of the Mooney viscosity (MV) value increased by more than 20% compared to general carbon black (nCB).

[0165] Through this, it was confirmed that high-quality carbon black powder blended with 5 to 25 wt% of recycled carbon black with a steam activation treatment time of less than 10 hours is desirable for use as a rubber composite additive in terms of rubber processability.

[0166] In particular, as the steam activation treatment time increased, physical properties such as specific surface area (N2SA), IA value (Iodine Adsorption), and oil absorption (OAN) improved, significantly enhancing the physical bonding strength between the rubber and recycled carbon black. This enhanced bonding strength increases the hardness of the rubber composite and raises the tensile modulus (M300) factor, which acts as an important factor in improving the durability and mechanical strength of rubber products.

[0167] Furthermore, it was confirmed that activating recycled carbon black through steam activation treatment and applying it to rubber composites together with general carbon black can achieve superior physical properties compared to existing methods and can serve as an effective alternative for improving the performance of tires and other high-performance rubber products.

[0168] However, considering the balance between economic feasibility, rubber properties, and carbon black properties, it was confirmed that steam activation treatment for 2 to 6 hours provides optimal results. When steam activation treatment exceeded 6 hours, the improvement effect was limited. As the content of recycled carbon black (rCB), which has increased properties such as specific surface area (N2SA) and oil absorption (OAN) through steam activation treatment for more than 6 hours, increased, it became undispersed within the rubber, resulting in a decrease in properties. Furthermore, as the steam activation treatment time increased, the properties of the rubber composite, such as MV (Mooney Viscosity), also increased. Additionally, as the process time lengthened, energy consumption and costs rose, and the performance improvement effect may be limited. Therefore, considering economic feasibility, it is desirable to perform steam activation treatment for 2 to 6 hours, and it is determined that performing it for 2 to 4 hours is the most effective.

[0169] As such, by including a blending ratio of 5 to 25 wt% of recycled carbon black (rCB) in high-quality carbon black powder for rubber composite additives due to the increase in the specific surface area (N2SA) and IA value (Iodine Adsorption) of recycled carbon black achieved through optimal steam activation treatment, it is possible to achieve optimal performance of the rubber composite while simultaneously realizing resource recycling and cost reduction, thus allowing for economic and eco-friendly effects.

[0170]

[0171] Although the present invention has been described above with reference to embodiments, various changes and modifications can be made by those skilled in the art to which the present invention pertains. Such changes and modifications are considered to be within the scope of the present invention as long as they do not depart from the technical concept provided by the present invention. Accordingly, the scope of rights of the present invention should be determined by the claims set forth below.

[0172]

[0173] [Explanation of the symbol]

[0174] S110: Recycled Carbon Black Transfer Step

[0175] S120: Steam activation processing steps S

[0176] S130: Step to obtain recycled carbon black powder

[0177] S140: Mixing step of recycled carbon black powder and ordinary carbon black powder

Claims

1. 5 to 25 wt% of steam-activated recycled carbon black powder; and Contains 75 to 95 weight percent of general carbon black; and The above steam-activated recycled carbon black powder is characterized by having an increased specific surface area. High-quality carbon black powder for rubber composite additives.

2. In Paragraph 1, The above steam-activated recycled carbon black powder is Characterized by containing a content ratio of 5 to 15 weight percent, High-quality carbon black powder for rubber composite additives.

3. In Paragraph 1, The above steam-activated recycled carbon black powder is Characterized by having an IA value of 100 to 550 g / kg, an N2SA value of 100 to 380 m² / g, an OAN value of 100 to 200 ml / 100g, and a Tint value of 45 to 55% ITRB, High-quality carbon black powder for rubber composite additives.

4. A rubber composite comprising high-quality carbon black powder for rubber composite additives according to any one of claims 1 to 3, The above high-quality carbon black powder is, 5 to 25 wt% of steam-activated recycled carbon black powder; and Contains 75 to 95 weight percent of general carbon black; and The above steam-activated recycled carbon black powder is characterized by having an increased specific surface area. Rubber composite containing high-quality carbon black powder.

5. In Paragraph 4, The above high-quality carbon black powder is Characterized by having an IA value of 40 to 130 g / kg, an N2SA value of 40 to 130 m² / g, an OAN value of 90 to 130 ml / 100g, and a Tint value of 40 to 60% ITRB, Rubber composite containing high-quality carbon black powder.

6. In Paragraph 4, The above rubber composite is The high-quality carbon black powder and rubber composition described above are included, wherein the high-quality carbon black powder comprises 1 to 30 parts by weight per 100 parts by weight of the rubber composition. Rubber composite containing high-quality carbon black powder.

7. In Paragraph 4, The above rubber composite is Characterized by having a tensile strength (TB) of 221 to 230 kgf / ㎠, a tensile modulus (M300) of 104 to 110 kgf / ㎠, and an elongation (EB) of 500 to 520%. Rubber composite containing high-quality carbon black powder.

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