Novel carbon black as well as preparation method and application thereof

Abstract

The invention discloses novel carbon black and a preparation method and application thereof.According to the method, waste tire thermal cracking carbon black is sequentially subjected to light oxidation treatment, high-temperature treatment, ultrasonic treatment, modification and grinding classification, the novel carbon black good in abrasion resistance is obtained, and the novel carbon black has the advantages of being high in dispersity, medium and high in abrasion resistance, low in heat generation and the like; the device can be used in tires or conveyor belts.

Description

Technical Field

[0001] The invention relates to the technical field of waste tire recycling, and in particular to a novel carbon black and a preparation method and application thereof. Background Art

[0002] The waste tire pyrolysis process is a thermal degradation process of polymer materials in an oxygen-deficient or oxygen-free environment. The solid phase product of pyrolysis is a mixed carbon slag, which is processed by iron removal and grinding to obtain the product called waste tire pyrolysis carbon black.

[0003] Waste tire pyrolysis carbon black is composed of various types of carbon black, white carbon black, inorganic additives and coke substances formed by cracking and disproportionation reactions in the tire formula, and the main component is carbon black. The generation process of waste tire pyrolysis carbon black is completely different from that of industrial carbon black. Industrial carbon black is composed of hydrocarbon molecules that are cracked, dehydrogenated and polymerized at high temperature to generate fine particles with a diameter of 1-2nm. The collision between the fine particles generates spherical particles with a diameter of 10-50nm and melts into grape-like aggregate units. In contrast, pyrolysis carbon black is composed of micron-sized particles produced by mechanical grinding and classification. Each particle is composed of countless nano-sized carbon black particles that are aggregated and wrapped by inorganic, organic and coke layers. Due to the large particle size, low specific surface area, low surface activity, low dispersion in rubber, and less rubber bonding, pyrolysis carbon black has poor mechanical properties and wear resistance when used as rubber carbon black. It is not suitable for use in tire tread rubber or conveyor belt covering during recycling. Summary of the invention

[0004] In order to improve the performance defects of pyrolysis carbon black, the present invention proposes a preparation method of a novel carbon black and the obtained novel carbon black and application thereof.

[0005] In the first aspect of the present invention, the present invention provides a method for treating waste tire pyrolysis carbon black. According to a specific embodiment of the present invention, the method comprises:

[0006] (1) subjecting waste tire thermal cracking carbon black powder to light oxidation treatment;

[0007] (2) subjecting the carbon black after light oxidation treatment to high temperature treatment;

[0008] (3) subjecting the carbon black subjected to high temperature treatment to ultrasonic treatment;

[0009] (4) The carbon black after ultrasonic treatment is modified and ground and classified to obtain a new type of carbon black.

[0010] In the second aspect of the present invention, the present invention provides a new type of carbon black prepared by the method described in the first aspect of the present invention.

[0011] In the third aspect of the present invention, the present invention proposes an application scheme of the new carbon black described in the second aspect of the present invention, and the application includes the application of the new carbon black in tires and / or conveyor belts.

[0012] Beneficial effects of the present invention:

[0013] By subjecting waste tire pyrolysis carbon black to light oxidation treatment, high temperature treatment, ultrasonic treatment, modification and grinding classification in sequence, a new type of carbon black with good wear resistance is obtained. It has the advantages of high dispersibility, medium to high wear resistance, low heat generation, etc., and can be used in tires or conveyor belts.

[0014] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0015] The embodiments of the present invention are described in detail below, which are intended to explain the present invention but should not be construed as limiting the present invention.

[0016] In the first aspect of the present invention, the present invention provides a method for treating waste tire pyrolysis carbon black. According to a specific embodiment of the present invention, the method comprises:

[0017] S100: Light oxidation treatment of waste tire pyrolysis carbon black powder

[0018] In this step, the waste tire pyrolysis carbon black powder is lightly oxidized to obtain lightly oxidized carbon black. The inventors found that the pyrolysis carbon black has very few oxygen-containing functional groups on the surface, and light oxidation treatment can increase the oxygen-containing functional groups on the carbon black surface, thereby improving the bonding strength with rubber.

[0019] In some embodiments, the light oxidation treatment is performed in an atmosphere furnace. Specifically, the light oxidation treatment includes: placing the thermal cracking carbon black in the atmosphere furnace, first introducing oxygen, and then heating and keeping the furnace warm.

[0020] In some embodiments, the flow rate of the oxygen is 0.2 to 1 L / min.

[0021] In some embodiments, the heating rate is 2-10° C. / min.

[0022] In some embodiments, the end point of the temperature increase is 200-350°C, for example, 200°C, 250°C, 300°C, 350°C, etc.

[0023] In some embodiments, the insulation time is 10 to 40 minutes.

[0024] Preferably, the waste tire pyrolysis carbon black is crushed in advance to obtain waste tire pyrolysis carbon black powder, and the powder with a certain particle size distribution range is screened. Specifically, the waste tire pyrolysis carbon black powder has a D50 particle size of 8 to 13 μm, a D90 particle size of 20 to 40 μm, and a particle size distribution width span of 1.5 to 2.5.

[0025] S200: High temperature treatment of carbon black after light oxidation treatment

[0026] In this step, the carbon black after light oxidation treatment is subjected to high temperature treatment to obtain high temperature treated carbon black. Through high temperature treatment, some impurities (such as residual rubber hydrocarbons, pyrolysis oil, etc.) covering the surface of waste tire pyrolysis carbon black can be removed, which is beneficial to subsequent ultrasonic and grinding treatments. In addition, the surface functional groups of pyrolysis carbon black can be exposed, the structure and specific surface area of ​​pyrolysis carbon black can be improved, and the interaction between carbon black particles and rubber molecular chains can be improved.

[0027] In some embodiments, the high temperature treatment comprises: heating the waste tire pyrolysis carbon black at 400-900° C. for 20-60 min in an inert gas environment.

[0028] S300: Ultrasonic treatment of carbon black after high temperature treatment

[0029] In this step, the carbon black after high temperature treatment is subjected to ultrasonic treatment to obtain ultrasonically treated carbon black. Ultrasonic treatment can further separate substances on the surface of thermally cracked carbon black, for example, substances such as silicon dioxide and zinc oxide that are originally bonded and coated on the surface can be physically separated to the greatest extent, and the shear force generated by high-speed stirring is conducive to separating substances wrapped inside the carbon black.

[0030] In some embodiments, the ultrasonic treatment comprises: dispersing the carbon black after the high temperature treatment in water, and then sequentially performing ultrasonic treatment, stirring, solid-liquid separation and drying treatment.

[0031] In some embodiments, the ultrasound frequency is 20 to 40 kHz, and the duration is 20 to 30 min;

[0032] In some embodiments, the stirring speed is 2000-4000 r / min, and the time is 10-20 min;

[0033] In some embodiments, the drying is performed at a temperature of 100 to 150° C. for 2 to 3 hours.

[0034] S400: Modification and grinding of ultrasonically treated carbon black

[0035] In this step, the ultrasonically treated carbon black is modified and ground and classified to obtain a new type of carbon black. The ultrasonic treatment reduces the agglomeration of carbon black aggregates, and the grinding and classification makes the carbon black particle size smaller and the distribution width narrower, so that the reinforcing performance in rubber will be better.

[0036] In some embodiments, the polyether polyol includes at least one of polytetramethylene glycol, polyethylene glycol, and polypropylene glycol.

[0037] In some embodiments, the mass ratio of the carbon black to the polyether polyol after the ultrasonic treatment is 100:1-3.

[0038] In some embodiments, the grinding and classification is performed in an impact mill and a classifier, the frequency of the mill main machine of the impact mill is 40 to 50 Hz, and the frequency of the classifier is 20 to 40 Hz.

[0039] In some embodiments, the carbon black after grinding and classification has a D50 particle size of 4 to 10 μm, a D90 particle size of 7 to 13 μm, and a particle size distribution width Span of no more than 1.0.

[0040] In the second aspect of the present invention, the present invention provides a new type of carbon black prepared by the method described in the first aspect of the present invention.

[0041] It should be noted that the characteristics and advantages described above for the method for treating waste tire pyrolysis carbon black are also applicable to the new carbon black and will not be described in detail here.

[0042] In the third aspect of the present invention, the present invention proposes an application scheme of the new carbon black described in the second aspect of the present invention, and the application includes the application of the new carbon black in tires and / or conveyor belts.

[0043] It should be noted that the characteristics and advantages described above for the method for treating waste tire pyrolysis carbon black and the new carbon black are also applicable to this application and will not be repeated here.

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Unless otherwise specified, the preparation processes in the following embodiments and comparative examples are all conventional means in the prior art in the art, and therefore, they are not described in detail.

[0046] The waste tire pyrolysis carbon black powder is a commercially available product purchased from Qingdao Ixstar Technology Co., Ltd. with a brand name of FN330.

[0047] Example 1

[0048] (1) 60 g of thermal cracking carbon black powder (D50 particle size of 10 μm, D90 particle size of 30 μm, particle size distribution width span of 1.5) was placed in an atmosphere furnace, and then oxygen (oxygen flow rate of 0.5 L / min) was introduced, and the temperature in the furnace was increased at a rate of 5°C / min to 300°C and maintained for 20 minutes;

[0049] (2) placing the carbon black after light oxidation treatment into a rotary graphite high temperature furnace and heating it at 600° C. for 0.5 h in a nitrogen atmosphere to obtain carbon black after high temperature treatment;

[0050] (3) mixing the high temperature treated carbon black with water in a mass ratio of 1:3, oscillating in 20kHz ultrasound for 20 minutes, and then stirring with a stirring paddle at a speed of 2000 r / min for 20 minutes, and then vacuum filtering the carbon black solution and placing it in an oven at 125° C. for 2-3 hours to dry, thereby obtaining ultrasonically treated carbon black;

[0051] (4) mixing the ultrasonically treated carbon black and polyethylene glycol in a mass ratio of 100:1.5 and placing them in an impact mill with a main machine frequency of 50 Hz, and then classifying them using a classifier with a frequency of 30 Hz to obtain ground and classified carbon black;

[0052] Example 2

[0053] In step (1), the oxygen feed rate was 0.2 L / min, the end point of the temperature rise was 200° C., the holding time was 10 min, and the rest was the same as in Example 1.

[0054] Example 3

[0055] Step (2) heating at 800°C for 0.5h, and the rest is the same as in Example 1.

[0056] Example 4

[0057] In step (4), the carbon black and polyethylene glycol after ultrasonic treatment are mixed in a mass ratio of 100:1.5, and the rest is the same as in Example 1.

[0058] Comparative Example 1

[0059] The commercially available waste tire thermal pyrolysis carbon black is not subjected to any treatment.

[0060] The carbon black obtained in each embodiment and comparative example was tested for performance, and the results are shown in Table 1. The testing method is as follows:

[0061] (1) STSA: refer to GB / T 10722-2014;

[0062] (2) DBP absorption value: refer to GB / T 3780.2-2017;

[0063] (3) Resilience: refer to GB / T 1681-2009;

[0064] (4) Heat generation: refer to GB / T 1687.3-2016;

[0065] (5) 300% tensile stress: refer to GB / T 3780.18-2017;

[0066] (6) DIN wear index: refer to GB / T 9867-2008;

[0067] (7) Akron wear volume: refer to GB / T 1689-2014.

[0068] Table 1 Performance test results of the new carbon black in each embodiment and comparative example

[0069]

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0071] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for treating waste tire thermal cracking carbon black, characterized in that: The method comprises: (1) subjecting waste tire thermal cracking carbon black powder to light oxidation treatment; (2) subjecting the carbon black after light oxidation treatment to high temperature treatment; (3) subjecting the carbon black subjected to high temperature treatment to ultrasonic treatment; (4) The carbon black after ultrasonic treatment is modified and ground and classified to obtain a new type of carbon black.

2. The method according to claim 1, characterized in that In step (1), the flow rate of oxygen is 0.2 to 1 L / min; and / or, The heating rate is 2-10°C / min; and / or, The end point of the heating is 200-350°C; and / or, The insulation time is 10 to 40 minutes.

3. The method according to claim 1, characterized in that In step (2), the high temperature treatment comprises: heating the waste tire thermal cracking carbon black at 400 to 900° C. for 20 to 60 minutes in an inert gas environment.

4. The method according to claim 1, characterized in that: In step (3), the ultrasonic treatment comprises: dispersing the carbon black after high temperature treatment in water, and sequentially performing ultrasonic treatment, stirring, solid-liquid separation and drying; and / or, The frequency of the ultrasound is 20 to 40 kHz, and the duration is 20 to 30 minutes; and / or, The stirring speed is 2000-4000 r / min, and the stirring time is 10-20 min; and / or, The drying temperature is 100-150° C. and the drying time is 2-3 hours.

5. The method according to claim 1, characterized in that In step (4), the grinding and classification are carried out in an impact mill and a classifier, the frequency of the mill host is 40 to 50 kHz, and the frequency of the classifier is 20 to 30 kHz.

6. The method according to claim 1 or 5, characterized in that: In step (4), the D50 particle size of the novel carbon black is 4 to 6 μm, the D90 particle size is 7 to 13 μm, and the particle size distribution width Span is not greater than 0.

8.

7. The method according to claim 1, characterized in that In step (4), the polyether polyol comprises at least one of polytetrahydrofuran diol, polyethylene glycol, and polypropylene glycol; and / or, The mass ratio of the carbon black to the polyether polyol after the ultrasonic treatment is 100:1-3.

8. A novel carbon black, characterized in that: The method of preparing the product is as described in any one of claims 1 to 8.

9. Use of the novel carbon black as claimed in claim 8 in tires and / or conveyor belts.

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