Method for reducing strength of cracked carbon black particles, carbon black particles and rubber

Abstract

The invention provides a method for reducing the strength of cracked carbon black particles, the carbon black particles and rubber, and belongs to the technical field of carbon black modification and rubber. The method for reducing the strength of the cracked carbon black particles comprises the steps that cracked carbon black powder and an aqueous solvent containing a softening agent are granulated, the carbon black particles are obtained, the mass percent of the softening agent in the aqueous solvent is 0.1%-0.6%, and the softening agent comprises saturated paraffin oil.

Description

Technical Field

[0001] The present disclosure belongs to the field of modification and rubber technology, and in particular relates to a method for reducing the strength of cracked carbon black particles, carbon black particles, and rubber. Background Art

[0002] An effective treatment for waste rubber is to thermally crack it to produce pyrolysis carbon black, which is then used as a reinforcing material in the production of rubber products, such as tires. However, the complex origin and composition of waste rubber results in high ash content and the presence of undecomposed rubber debris on the surface, which compromises the reinforcing properties of the pyrolysis carbon black.

[0003] In terms of application, pyrolysis carbon black is currently mainly used as a rubber reinforcing agent. However, because pyrolysis carbon black particles are small, if they are directly added to rubber, they are prone to flying during mixing, which not only causes dust pollution that harms the health of operators, but also leads to waste of raw materials and unstable quality of the mixed rubber. Therefore, in actual use, it is often necessary to make pyrolysis carbon black powder into particles with a diameter of about 1mm before adding it to the rubber for mixing. However, due to the complex composition of pyrolysis carbon black and the possibility of impurities such as rubber crumbs, SiO2, and ZnO mixed on the surface, the particles made from pyrolysis carbon black are relatively strong and difficult to break during mixing. At the same time, the particles dispersed in the rubber are larger in size, resulting in poor dispersion uniformity and reinforcement effect, which to a certain extent limits its application in rubber reinforcement. Summary of the Invention

[0004] To address the above-mentioned problems, the present disclosure provides a method for reducing the strength of pyrolyzed carbon black particles, carbon black particles, and rubber, in order to at least partially resolve the above-mentioned technical problems. The technical solutions provided by the present disclosure are as follows.

[0005] As a first aspect of the present disclosure, the present disclosure provides a method for reducing the strength of cracked carbon black particles, comprising: granulating cracked carbon black powder with an aqueous solvent containing a softener to obtain carbon black particles, wherein the mass percentage of the softener in the aqueous solvent is 0.1%-0.6%, and the softener includes saturated paraffin oil.

[0006] As a second aspect of the present disclosure, a carbon black particle is provided, which is prepared by the above method.

[0007] As a third aspect of the present disclosure, a carbon black particle-modified rubber is provided, which comprises, by mass, 100 parts of natural rubber, 3 parts of stearic acid, 5 parts of zinc oxide, 0.6 parts of an accelerator, 2.5 parts of sulfur, and 50 parts of carbon black particles; wherein the carbon black particles are the carbon black particles of the second aspect.

[0008] Based on the above technical solution, the present disclosure provides a method for reducing the strength of cracked carbon black particles, carbon black particles, and rubber, which have at least one of the following beneficial effects:

[0009] (1) In the embodiments of the present disclosure, an aqueous solvent containing saturated paraffin oil (softener) is added to the granulation process of the pyrolysis carbon black to perform granulation. The softener is used to change the surface properties of the pyrolysis carbon black powder and reduce the interaction force between the pyrolysis carbon black powders, thereby achieving the purpose of reducing the strength of the pyrolysis carbon black particles after granulation.

[0010] (2) In the embodiments of the present disclosure, cracked carbon black particles with reduced strength are applied to rubber as a reinforcing agent. During the mixing process, the strength of the cracked carbon black particles is reduced and they are easily crushed, thereby improving their dispersibility in the rubber, particle size, and mixing operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The figures are particle strength graphs of pyrolysis carbon black particles obtained by granulating different softeners with pyrolysis carbon black powder, wherein (a) is a particle strength graph of paraffin oil-pyrolysis carbon black particles obtained by granulating paraffin oil with pyrolysis carbon black powder in Example 1 of the present disclosure, (b) is a particle strength graph of linseed oil-pyrolysis carbon black particles obtained by granulating linseed oil with pyrolysis carbon black powder in Comparative Example 1 of the present disclosure, (c) is a particle strength graph of castor oil-pyrolysis carbon black particles obtained by granulating castor oil with pyrolysis carbon black powder in Comparative Example 2 of the present disclosure, and (d) is a particle strength graph of glycerol-pyrolysis carbon black particles obtained by granulating glycerol with pyrolysis carbon black powder in Comparative Example 3 of the present disclosure;

[0012] Figure 2 Figures 3 and 4 are particle strength diagrams of pyrolysis carbon black particles obtained at different granulation times in Example 3 of the present disclosure, wherein (a) is a particle strength diagram of pyrolysis carbon black particles obtained after granulation for 14 minutes, (b) is a particle strength diagram of pyrolysis carbon black particles obtained after granulation for 16 minutes, and (c) is a particle strength diagram of pyrolysis carbon black particles obtained after granulation for 18 minutes;

[0013] Figure 3 The particle strength diagram of paraffin oil-pyrolysis carbon black particles obtained by granulating paraffin oil with pyrolysis carbon black powder in Example 2 of the present disclosure at an addition amount of 0.6 wt %. DETAILED DESCRIPTION

[0014] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0015] With the development of the transportation industry, the demand and production of tires have grown rapidly, and this has also been accompanied by the generation of a large number of waste tires, causing serious environmental pollution and waste of resources. In the process of implementing the invention disclosed herein, it was discovered that one way to effectively treat waste tires is to pyrolyze waste tires at high temperature (300-1000°C) and in a vacuum environment to produce pyrolysis carbon black, and use it as a reinforcing material for rubber in tire production (accounting for about 30% of the tire's weight). Using pyrolysis carbon black produced by pyrolysis of waste tires to replace virgin carbon black can not only save a lot of energy and fuel use and reduce CO2 emissions, but also use it as a tire reinforcement material to reduce tire production costs, achieve considerable economic benefits, and realize the recycling of tire production materials. In other words, pyrolysis carbon black generated by high-temperature pyrolysis of waste tires is an important way to achieve green, low-carbon and economic circulation.

[0016] However, the structure of scrap tires is complex, encompassing various components such as the tread and sidewall. The varying performance requirements of each component lead to differences in the raw material composition required for each component. Furthermore, tire formulations vary between different brands, leading to a complex raw material composition and diverse sources for the production of pyrolysis carbon black. This diverse raw material source results in a complex composition and unstable quality of pyrolysis carbon black. Its composition includes not only virgin carbon black and silica (SiO2) of varying particle sizes added during tire production, but also various additives used in tire formulations, such as ZnO and sulfur. This complex composition results in an uneven particle size distribution, high ash content, and a high level of impurities in the pyrolysis carbon black particles. The high ash content and impurities in pyrolysis carbon black, as well as the potential for residual undecomposed rubber debris on the surface, are the primary reasons for the rubber's poor performance.

[0017] In terms of application, pyrolysis carbon black is currently primarily used as a rubber reinforcing agent in tire production. However, due to the small size of pyrolysis carbon black particles, if added directly to rubber for mixing, they will fly, causing dust pollution that harms the health of operators, as well as waste of raw materials and unstable rubber compound quality. Therefore, in actual use, the pyrolysis carbon black powder is often refined into pellets with a diameter of approximately 1mm through a process of mixing with water, granulation, and drying, and then added to the rubber for mixing. To facilitate mixing and dispersion of pyrolysis carbon black in rubber, the resulting carbon black pellets must be easily crushed during mixing. However, due to the complex composition of pyrolysis carbon black and the potential presence of impurities such as rubber crumbs, SiO2, and ZnO on its surface, the pellets produced from pyrolysis carbon black have a high strength, making them difficult to crush and disperse into the rubber during mixing. This results in larger particles dispersed into the rubber, poor dispersion uniformity, and poor reinforcement, which to some extent limits its application in rubber reinforcement.

[0018] In addition, the surface activity of pyrolysis carbon black is low, the interaction between it and rubber is weak, and the reinforcement effect is poor. In actual production, it is often necessary to add different surfactants to increase the surface activity of pyrolysis carbon black and improve its interaction with rubber. However, while adding surfactants to improve the interaction between carbon black and rubber, it also increases the interaction between pyrolysis carbon black powders, further increasing the particle strength of pyrolysis carbon black, and limiting the mixing uniformity between it and rubber.

[0019] In response to the problem that the pyrolysis carbon black has high particle strength during granulation, which limits its good dispersibility in rubber during mixing, the present invention selects a suitable softener to mix with the pyrolysis carbon black powder for granulation, thereby reducing the particle strength of the pyrolysis carbon black, so that the obtained pyrolysis carbon black can be easily crushed and evenly dispersed in the rubber, thereby enhancing the uniformity and operability of the pyrolysis carbon black particles in the rubber without significantly affecting the performance of the rubber.

[0020] Specifically, as a first aspect of the present disclosure, a method for reducing the strength of cracked carbon black particles is provided, comprising: granulating cracked carbon black powder with an aqueous solvent containing a softener to obtain carbon black particles, wherein the mass percentage of the softener in the aqueous solvent is 0.1%-0.6%, and the softener includes saturated paraffin oil.

[0021] In the embodiments disclosed herein, a saturated paraffin oil is selected as a softener. An aqueous solvent containing the softener is added during the granulation of the pyrolysis carbon black powder. The softener modifies the surface properties of the pyrolysis carbon black powder and reduces the interaction between the pyrolysis carbon black powder, thereby achieving the purpose of reducing the strength of the pyrolysis carbon black particles after granulation. The reason for selecting saturated paraffin oil as a softener is that saturated paraffin oil is mainly composed of alkane compounds, rich in hydrocarbons, and does not contain unsaturated functional groups such as double bonds and triple bonds. It has low activity. After adding pyrolysis carbon black, it does not change the activity of the pyrolysis carbon black surface. It mainly plays a softening and lubricating role, thereby reducing the strength of the pyrolysis carbon black particles. Unsaturated fatty acids, on the other hand, contain a large number of carbon-carbon unsaturated bonds, carboxylic acids, hydroxyl groups, etc. After adding pyrolysis carbon black, the number of active groups on the pyrolysis carbon black surface increases, and the interaction between the pyrolysis carbon black is enhanced, resulting in an increase in the strength of the pyrolysis carbon black particles after granulation compared to the strength of the pyrolysis carbon black particles obtained by direct granulation of the pyrolysis carbon black powder. When hydroxyl-containing alcohols are added to pyrolysis carbon black powder and pelletized, the increased number of hydroxyl groups on the carbon black surface increases its surface activity and interactions, thereby increasing the strength of the pellets after pelletization. However, some hydroxyl-containing alcohols (such as glycerol) act as lubricants. While the introduction of active groups like hydroxyl groups increases the strength of the carbon black pellets, this lubricating effect can reduce the pellet strength, partially offsetting the increase in strength caused by the active groups. This significantly reduces the overall strength of the pellets, sometimes even reducing the pellet strength to below that of pellets without a softener. Therefore, it is preferable to use a saturated paraffin oil as a softener to reduce the pellet strength of the pyrolysis carbon black after pelletization.

[0022] Furthermore, according to an embodiment of the present disclosure, the saturated paraffin oil includes: paraffin oil; and the aqueous solvent containing the softener is emulsified, and the aqueous solvent is deionized water. The main component of paraffin oil is full paraffin oil, which is mainly a mixture of several hydrocarbons such as normal alkanes, cycloalkanes, and straight-chain alkanes. It does not contain active substances such as double bonds, triple bonds, hydroxyl groups, and carboxyl groups, thereby reducing the particle strength of the cracked carbon black. In addition, because the saturated paraffin oil is insoluble in water (such as deionized water), ultrasonic emulsification with water (frequency of 40kHz-60kHz) can evenly disperse the saturated paraffin oil in water to form an aqueous solvent containing saturated paraffin oil, thereby strengthening the contact and uniform mixing of the cracked carbon black and the softener during the granulation process.

[0023] According to embodiments of the present disclosure, pyrolysis carbon black is a cracking product of waste rubber, where the rubber can be derived from waste tires. Furthermore, the disclosed method for reducing the strength of pyrolysis carbon black particles can also be applied to virgin carbon black or silica. Applying a softener to these virgin carbon black and silica can also reduce particle strength. The principle is the same as for pyrolysis carbon black in this application and will not be further elaborated here.

[0024] According to an embodiment of the present disclosure, during the granulation process, the mass of the aqueous solvent is 40%-60% of the mass of the pyrolysis carbon black powder. Within this range, the pyrolysis carbon black powder can form granules during the granulation process, and the formed granules are not easily dispersed. Furthermore, the granulation process is a stirring granulation process with a rotation speed of 30 rpm and a granulation time of 14-18 minutes. The length of the granulation time affects the change in the strength of the granules. A shortened granulation time (e.g., less than 14 minutes) does not change the strength of the granules, and increasing the granulation time does not further reduce the strength of the pyrolysis carbon black granules.

[0025] As a second aspect of the present disclosure, a carbon black particle is provided, which is prepared by the above-mentioned method for reducing the strength of cracked carbon black particles.

[0026] In the examples disclosed herein, the carbon black pellets produced using the above method exhibited a 20%-30% decrease in strength compared to virgin pyrolysis carbon black pellets obtained by direct granulation of pyrolysis carbon black powder without the addition of a softener. Furthermore, the softener containing unsaturated fatty acids resulted in an increase in pellet strength compared to virgin pyrolysis carbon black pellets without the addition of a softener.

[0027] As a third aspect of the present disclosure, the present disclosure provides a rubber modified with carbon black particles, which comprises, in parts by mass: 100 parts of natural rubber, 3 parts of stearic acid, 5 parts of zinc oxide, 0.6 parts of an accelerator, 2.5 parts of sulfur, and 50 parts of carbon black particles; wherein the carbon black particles are obtained by granulating cracked carbon black powder with an aqueous solvent containing a softener, the mass percentage of the softener in the aqueous solvent is 0.1%-0.6%, and the softener comprises a saturated paraffin oil.

[0028] In the embodiments of the present disclosure, the particle strength of the pyrolysis carbon black treated with a softener is reduced, and when the pyrolysis carbon black is added to the rubber as a reinforcing agent for mixing, the reinforcing properties of the obtained rubber are slightly increased.

[0029] To make the technical solution of this disclosure more clear and understandable, and to highlight its advantages, the following detailed description of the method for reducing the strength of pyrolyzed carbon black particles, carbon black particles, and rubber is provided in conjunction with specific examples. It should be noted that the following examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. The raw materials and reagents used in this disclosure are all commercially available.

[0030] Example 1

[0031] In Example 1, the pyrolysis carbon black powder was granulated by a wet granulation method to obtain pyrolysis carbon black particles. The specific granulation process is as follows.

[0032] Preparation of an aqueous solvent containing a softener: Since paraffin oil is insoluble in water, 0.4 wt% (0.4 g of paraffin oil is added to every 100 g of water) of paraffin oil is taken, the paraffin oil is added to deionized water (stratification occurs), and ultrasonicated for 10 minutes at a frequency of 40 kHz and 80 W using an ultrasonic machine to fully emulsify the paraffin oil in the water to obtain an aqueous solvent containing paraffin oil.

[0033] Granulation: Take 500g of pyrolysis carbon black powder, take 200g of prepared aqueous solvent containing softener and mix it into the pyrolysis carbon black powder according to the weight ratio of 40%, and use a mixer to stir and granulate at high speed to obtain pyrolysis carbon black particles of different particle size, and measure the particle strength. The rotation speed is 30 rpm and the granulation time is 14min. Subsequently, 30 pyrolysis carbon black particles with a particle size of about 1mm were selected from the granulated samples by screening method, and the strength of each particle was measured respectively. Based on this, the overall particle strength variation range and average particle strength were calculated as the particle strength value of the batch of samples, which further shows that the strength values ​​of different particles fluctuate within a certain range. The specific test results are as follows: Figure 1 As shown in (a) in the figure, the strength of particles produced under the same conditions fluctuates and is distributed, and the average value of the fit is generally used as the evaluation standard.

[0034] Based on the principle of ease of dispersion, the present disclosure also selected different softeners for experimentation. Because both vegetable oils and petroleum oils have significant softening and lubricating effects, the present disclosure selected unsaturated fatty acids (such as linseed oil and castor oil) and alcohols (such as glycerol) as softeners for mixed granulation (wherein the amount of linseed oil, castor oil, and glycerol was 0.4wt%). A screening method was then used to select 30 1mm-sized pyrolysis carbon black particles, and the specific tests for measuring the particle strength were the same as those described above, and the specific experiments are as shown in Comparative Examples 1 to 3. Furthermore, the same proportion of deionized water was added to the pyrolysis carbon black without any softener, and granulation and particle strength values ​​were measured according to the same process flow as in Example 1. This was used as a control group for comparison with the carbon black particle strength with the softener.

[0035] Among them, the calculation method of particle strength under the same test conditions is:

[0036] .

[0037] in, Indicates the change in particle strength; It represents the strength value of the original pyrolysis carbon black pellets (i.e. the original sample control) obtained after granulation of water and pyrolysis carbon black powder. It indicates the strength value of the pyrolysis carbon black (softener-pyrolysis carbon black) particles obtained by granulating the aqueous solvent containing softener and pyrolysis carbon black powder. The unit of particle strength is centinewton (cN).

[0038] Comparative Example 1

[0039] In Comparative Example 1, linseed oil was used as a softener (0.4 g of linseed oil was added to every 100 g of water, i.e., 0.4 wt%). Linseed oil-pyrolysis carbon black particles were obtained according to the aqueous solvent containing the softener and the granulation method in Example 1. The strength of the particles in Comparative Example 1 was measured. The specific test results are shown in FIG. Figure 1 As shown in (b) in .

[0040] Comparative Example 2

[0041] In Comparative Example 2, castor oil was selected as a softener (0.4 g of castor oil was added to every 100 g of water, i.e., 0.4 wt%), and castor oil-pyrolysis carbon black particles were obtained according to the aqueous solvent containing a softener and the granulation method in Example 1. The strength of the particles in Comparative Example 1 was measured. The specific test results are shown in FIG. Figure 1 As shown in (c) in the figure.

[0042] Comparative Example 3

[0043] In Comparative Example 3, glycerol was selected as a softener (0.4 g of glycerol was added to every 100 g of water, i.e., 0.4 wt%), and glycerol-pyrolysis carbon black particles were obtained according to the aqueous solvent containing a softener and the granulation method in Example 1. The strength of the particles in Comparative Example 1 was measured. The specific test results are shown in FIG. Figure 1 As shown in (d) in the figure.

[0044] It should be noted that Figure 1 (a)-(d) in the figure are samples from different batches, so the test results in the original sample control are different, but in the same figure (such as Figure 1 The original control and paraffin oil in (a) are from the same batch of samples. The different figures show the results of samples from different batches, and the intensity changes are compared by reducing the ratio.

[0045] Figure 1The graphs are of the particle strength of pyrolysis carbon black particles obtained by granulating different softeners with pyrolysis carbon black powder, wherein (a) is a graph of the particle strength of paraffin oil-pyrolysis carbon black particles obtained by granulating paraffin oil with pyrolysis carbon black powder in Example 1 of the present disclosure, (b) is a graph of the particle strength of linseed oil-pyrolysis carbon black particles obtained by granulating linseed oil with pyrolysis carbon black powder in Comparative Example 1 of the present disclosure, (c) is a graph of the particle strength of castor oil-pyrolysis carbon black particles obtained by granulating castor oil with pyrolysis carbon black powder in Comparative Example 2 of the present disclosure, and (d) is a graph of the particle strength of glycerol-pyrolysis carbon black particles obtained by granulating glycerol with pyrolysis carbon black powder in Comparative Example 3 of the present disclosure. It should be noted that Figure 1 With subsequent Figure 2 These were two independent experiments, and the raw materials were from different batches. The corresponding particle strength values ​​were different. The data mainly correspond to horizontal comparisons within the same batches, and no vertical comparison was made.

[0046] like Figure 1 The results show that the strength of pyrolysis carbon black pellets decreased by 24% after pelletization when paraffin oil was used as a softener, while the strength of pellets mixed with vegetable oils increased slightly. For example, the strength of linseed oil pellets increased by approximately 27.8%, and that of castor oil pellets increased by approximately 3.5%. The strength of pellets decreased by approximately 3.4% after the addition of glycerol. This difference in pellet strength is primarily due to the structural differences between the softeners. Although the addition of glycerol increases the strength of carbon black pellets by introducing more hydroxyl groups onto the carbon black surface, glycerol itself has a softening and lubricating effect, which reduces the pellet strength. This indicates that the overall strength of carbon black pellets decreases after the addition of glycerol. Linseed oil and castor oil are primarily unsaturated fatty acids, each containing a large number of reactive groups such as carbon-carbon unsaturated bonds, carboxylic acid groups, and hydroxyl groups. When pyrolysis carbon black is mixed with pyrolysis carbon black and pelletized, the surface active groups increase, enhancing interactions and resulting in a slight increase in pellet strength compared to pellets without the addition of a softener. The main component of paraffin oil is full paraffin oil, which is mainly a mixture of several hydrocarbons such as normal alkanes, cycloalkanes, branched alkanes, etc. It is rich in hydrocarbons, does not contain double bonds and triple bonds, and has low activity. Adding paraffin oil will not increase its surface activity. It mainly plays a lubricating and softening role to reduce the particle strength of cracked carbon black.

[0047] Example 2

[0048] The same softener and method as in Example 1 were used to prepare pyrolysis carbon black particles, with the only difference being that the softener was added in an amount of 0.6 wt % (ie, 0.6 g of paraffin oil per 100 g of water).

[0049] Figure 3 The particle strength diagram of paraffin oil-pyrolysis carbon black particles obtained by granulating paraffin oil with pyrolysis carbon black powder in Example 2 of the present disclosure at an addition amount of 0.6 wt %.

[0050] like Figure 3 As shown in the figure, when the amount of paraffin oil was added to 0.6wt%, it was found that the powder was difficult to granulate during granulation, and the strength value of the obtained particles decreased significantly, reaching 51.9%, indicating that the addition of 0.4wt% had the best effect.

[0051] Example 3

[0052] There is a close relationship between particle strength and granulation time. The same softener and method as in Example 1 were used to prepare pyrolysis carbon black particles. At the same time, 0.4wt% paraffin oil was added and the granulation time was 14 minutes, 16 minutes, and 18 minutes respectively. Pyrolysis carbon black particles with different granulation times were obtained and their particle strength was measured. The specific test results are shown in Figure 2. Figure 2 shown.

[0053] Figure 2 These are strength diagrams of the cracked carbon black particles obtained at different granulation times in Example 3 of the present disclosure, wherein (a) is a particle strength diagram of the cracked carbon black particles obtained after granulation for 14 minutes, (b) is a particle strength diagram of the cracked carbon black particles obtained after granulation for 16 minutes, and (c) is a particle strength diagram of the cracked carbon black particles obtained after granulation for 18 minutes.

[0054] like Figure 2 As shown in the figure, the strength of the pyrolysis carbon black particles with granulation time of 14 minutes, 16 minutes and 18 minutes respectively decreased by 28.4%, 27.2% and 26.4%, respectively, indicating that the longer the granulation time, the lower the reduction rate, among which the granulation time of 14 minutes is the best.

[0055] To further analyze the effect of paraffin oil treatment on the rubber reinforcement of pyrolysis carbon black, paraffin oil-pyrolysis carbon black pellets were prepared by adding 0.4 wt% paraffin oil as a softener. Rubber compounds were also prepared using the same virgin pyrolysis carbon black pellets according to the formulation shown in Table 1. These rubber films were then vulcanized at 145°C and 10 MPa for 30 minutes in a vulcanizer to produce 2 mm thick rubber films. The mechanical properties of the films were then tested using a universal tensile testing machine. The results are shown in Table 2.

[0056] Table 1

[0057]

[0058] Table 2

[0059]

[0060] As shown in Table 1, the particle strength of the pyrolysis carbon black treated with paraffin oil is significantly reduced, but the reinforcing performance of the rubber is slightly increased, but the increase is not significant. This shows that paraffin oil reduces the strength of the pyrolysis carbon black particles without affecting the performance of the pyrolysis carbon black modified rubber.

[0061] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present disclosure. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A method for reducing the strength of pyrolysis carbon black particles, comprising: The pyrolysis carbon black powder is granulated with an aqueous solvent containing a softener to obtain carbon black particles. The mass percentage of the softener in the aqueous solvent is 0.1%-0.6%, and the softener comprises saturated paraffin oil.

2. The method according to claim 1, wherein The saturated paraffin oil includes paraffin oil; and the aqueous solvent containing the softener is emulsified.

3. The method according to claim 2, wherein: The emulsification includes ultrasonic emulsification.

4. The method according to claim 1, wherein The pyrolysis carbon black is a pyrolysis product of waste rubber.

5. The method according to claim 1, wherein During the granulation process, the mass of the aqueous solvent is 40%-60% of the mass of the pyrolysis carbon black powder.

6. The method according to claim 1, wherein The aqueous solvent is deionized water.

7. The method according to claim 1, wherein The granulation process is stirring granulation, the rotation speed is 30 revolutions per minute, and the granulation time is 14-18 minutes.

8. Carbon black particles prepared by the method according to any one of claims 1 to 7.

9. A carbon black particle-modified rubber comprising, in parts by mass: 100 parts of natural rubber, 3 parts of stearic acid, 5 parts of zinc oxide, 0.6 parts of accelerator, 2.5 parts of sulfur, 50 parts of carbon black particles; Wherein, the carbon black particles are the carbon black particles according to claim 8.

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