High-performance rubber material containing waste tire extract and preparation method thereof

Abstract

The invention relates to the technical field of plastic waste recycling, in particular to a high-performance rubber material containing a waste tire extract and a preparation method of the high-performance rubber material. The problems that the extraction efficiency of the substances in the waste tires is low, and the comprehensive performance of the rubber material prepared from the extracted substances is poor are solved. The method comprises the following steps: thermally decomposing organic components of waste tires in a low-oxygen and inert atmosphere, cracking a hydrocarbon mixture, removing interfering metals by combining processes such as crushing, magnetic separation and acid treatment, carrying out secondary cracking to improve the carbon quality, and extracting zinc oxide, regenerated white carbon black and carbon black by adopting alkali liquor dissolution and carbon dioxide precipitation, so that the extraction rates of the three products are remarkably improved. On the basis of raw materials obtained by an optimized extraction process, the adding sequence, dosage and mixing conditions of different types of fillers and auxiliaries are optimized, and a stable vulcanization network is constructed by step-by-step mixing, so that the rebound resilience, wear resistance and wet skid resistance of the high-performance rubber material are improved, and efficient recovery of waste tires and preparation of the high-performance rubber material are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling of plastic waste, and specifically to a high-performance rubber material containing extracts from waste tires and a preparation method thereof. Background Art

[0002] With the rapid development of the automotive industry, the generation amount of waste tires has been increasing year by year. How to efficiently dispose of waste tires has become a global environmental and resource problem. Traditional methods for disposing of waste tires, such as landfilling and incineration, not only cause waste of resources, but also bring a series of environmental problems such as soil pollution and air pollution. Therefore, it is of great economic and environmental significance to recycle waste tires resourcefully and extract useful components such as zinc oxide, silica, and carbon black from them.

[0003] In the field of waste tire recycling, the existing technologies face many challenges in practical applications: Firstly, the decomposition efficiency of organic components in the pyrolysis process is insufficient, and the residual organic matter easily interferes with subsequent metal separation and filler purification, resulting in low product purity; Secondly, the separation process of carbon black and zinc oxide is complex, and traditional acid treatment and magnetic separation technologies are difficult to completely remove interfering metals such as iron, affecting the performance of recycled fillers; Thirdly, the extraction of silicate components and the control of the carbonization reaction are not accurate enough, resulting in a low specific surface area and loose structure of silica, which cannot meet the requirements for reinforcing high-performance rubber. The low extraction efficiency makes it difficult for recycled fillers to meet the industrial application standards in terms of resource utilization rate and performance stability.

[0004] In the high molecular rubber materials used in tires, with the continuous improvement of people's requirements for automotive safety, comfort, and fuel economy, higher standards have been put forward for their performance. High resilience can improve driving comfort and reduce energy loss during vehicle driving; excellent wear resistance can extend the service life of rubber products and reduce the replacement frequency; good anti-slip performance is directly related to driving safety, especially on wet and slippery road conditions such as rainy days, which can effectively prevent vehicles from skidding out of control. However, the existing technologies for preparing high molecular rubber materials have difficulties in achieving a balance of the above performances. When improving the anti-slip performance of rubber materials, their resilience and wear resistance are often sacrificed; or in order to enhance the wear resistance, the rubber materials become hard, resulting in a decrease in resilience and anti-slip performance.

[0005] Therefore, a high-performance rubber material containing extracts from waste tires and a preparation method thereof are proposed. Summary of the Invention

[0006] The object of the present invention is to provide a high-performance rubber material containing waste tire extract and a preparation method thereof. By precisely controlling hydrocarbon cracking through low-oxygen thermal decomposition combined with a two-chamber furnace reactor, supplemented by crushing, magnetic separation, acid treatment, and treatment with an iron ion adsorption resin, interference metals are effectively removed and the quality of carbon black is improved; the zinc oxide and regenerated silica are respectively extracted by an alkali solution dissolution and carbon dioxide precipitation process to achieve efficient resource recovery. By optimizing the parameters of the sodium silicate solution and reaction conditions, the high specific surface area and uniform dispersion of the regenerated silica are ensured, significantly enhancing the wet skid resistance of the rubber material; at the same time, the multi-stage mixing process reasonably regulates the addition sequence of fillers and additives and the vulcanization conditions, avoids early vulcanization, strengthens the filler-matrix interface bonding, and constructs a uniform cross-linked network, ultimately obtaining a rubber material with high resilience, low rolling resistance, and excellent wear resistance. The present invention solves the problems of impurity residues, insufficient filler performance, and low mixing efficiency in traditional recycling processes, providing an efficient and environmentally friendly technical route for the resource utilization of waste tires and the development of high-performance rubber products.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The present invention provides a preparation method of a high-performance rubber material containing waste tire extract, and the preparation method is as follows:

[0009] First-stage mixing: Add regenerated silica, coupling agent, and carbon black to raw rubber, mix, and discharge the rubber at 115 - 127 °C to obtain a first-stage mixed material;

[0010] Second-stage mixing: Add the remaining regenerated silica, the coupling agent, and zinc oxide, mix, and discharge the rubber at 105 - 110 °C to obtain a second-stage mixed material;

[0011] Third-stage mixing: Add sulfur and accelerator, mix, discharge the rubber at 95 - 105 °C, stand for vulcanization, and obtain the high-performance rubber material; the thickness of the pressed sheet is 10 - 15 mm;

[0012] The accelerator is obtained by mixing tetrabenzylthiuram disulfide and 2-mercaptobenzimidazole in a mass ratio of 1:1, does not release carcinogenic nitrosamines, and the N-nitrosamine content is < 0.5 ppm, meeting the EU REACH regulation;

[0013] The waste tire extract is composed of the regenerated silica, the carbon black, and the zinc oxide.

[0014] Preferably, the total amount of the regenerated silica used in the first-stage mixing and the second-stage mixing is 24 - 46 phr; the amount of the zinc oxide used is 3.5 - 5.2 phr; the total amount of the coupling agent used in the first-stage mixing and the second-stage mixing is 3.6 - 5.4 phr; the amount of the carbon black used is 2.5 - 5 phr; the amount of the zinc oxide used is 3.5 - 10 phr.

[0015] Preferably, the preparation method of the carbon black is as follows:

[0016] The waste tires are crushed to remove steel wires, and after further crushing, they are pyrolyzed at 450 - 550 °C to obtain pyrolysis oil and rubber residues.

[0017] The pyrolysis oil enters a double-chamber furnace reactor and is burned successively in a first chamber at 1500 - 1700 °C and a second chamber at 1000 - 1300 °C, followed by quenching separation and grinding to obtain the carbon black.

[0018] Preferably, the preparation method of the zinc oxide is as follows:

[0019] The rubber residues are pulverized, and after two magnetic separations, ultrafine rubber residues are obtained; the ultrafine rubber residues are subjected to secondary pyrolysis treatment at 300 - 500 °C; then acid treatment is carried out for 2 - 4 h, and the rubber residue filter cake and the acidified liquid precursor are separated; the acidified liquid precursor is treated with an anion exchange resin to obtain the acidified liquid; the particle size of the ultrafine rubber residues is 100 - 400 mesh; the acid agent used for the acid treatment is one of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid.

[0020] The acidified liquid is concentrated to a solid content of 15% - 18%, mixed with an alkali solution for reaction, and the resulting precipitate is calcined at 450 - 600 °C for 2 h and then ground to obtain the zinc oxide.

[0021] Preferably, the preparation method of the regenerated white carbon black is as follows:

[0022] Caustic soda solution is added to the rubber residue filter cake, and it is dissolved and treated at 50 - 180 °C and 0.05 - 1.3 MPa for 0.1 - 5 h, followed by plate-and-frame filtration to obtain a mixed solution containing sodium silicate solution; carbon dioxide is introduced into the mixed solution, and the reaction is carried out at 40 - 98 °C for 1 - 5 h, and white carbon black filter cake and the mixed alkali solution are generated through plate-and-frame filtration; the mixed alkali solution is recycled; the white carbon black filter cake is washed and dried to obtain the regenerated white carbon black filter cake; the regenerated white carbon black filter cake is ground to obtain the regenerated white carbon black; the solid content of sodium silicate in the mixed solution is 5% - 30%, and the modulus is 1.5 - 3.8; more preferably, the solid content is 10% - 20%, and the modulus is 2.5 - 3.5.

[0023] The particle size of the regenerated white carbon black is 7 - 12 μm; the particle size of the zinc oxide is 0.5 - 2 μm; the particle size of the carbon black agglomerate is 80 - 300 nm.

[0024] Sodium silicate is expressed by the composition ratio of Na2O·nSiO2. The molar ratio of SiO2 to Na2O is called the modulus, and the modulus can vary. As the modulus changes, its properties also change; sodium silicate with a modulus greater than 3 is neutral water glass, and that less than 3 is alkaline water glass. By adjusting the modulus, the particle size, structural compactness, and dispersibility of the prepared regenerated silica can be adjusted, so that the finally prepared rubber material has high performance.

[0025] Preferably, the two magnetic separations are the first magnetic separation and the second magnetic separation; the magnetic separation intensity of the first magnetic separation is 0.1 - 0.3T; the magnetic separation intensity of the second magnetic separation is 0.5 - 0.8T.

[0026] Preferably, the feeding flow rate of carbon dioxide is 0.5 - 2.0L / min; the pH value of the reaction system when carbon dioxide is introduced is 7.5 - 9.5.

[0027] The above preparation method is applicable to the manufacture of car tire tread materials. For the tire sidewall, carcass ply, inner liner, or other parts of the tire, the regenerated silica, zinc oxide, and carbon black used in the formulation can be adjusted according to the specific preparation method of the present invention, and the formulation types and dosages can be adjusted according to actual requirements.

[0028] The present invention provides a high-performance rubber material containing waste tire extracts. The high-performance rubber material is prepared by the preparation method described in any one of the above; the raw materials for preparing the high-performance rubber material include the waste tire extracts, raw rubber, coupling agent, stearic acid, Fischer-Tropsch wax, epoxidized soybean oil, sulfur, and accelerator; the waste tire extracts include regenerated silica, carbon black, and zinc oxide; the raw rubber is obtained by mixing a random copolymer of butadiene and styrene monomers and rare-earth cis-polybutadiene rubber in a mass ratio of 9:1; the high-performance rubber material has a 0°C tanδ of 0.353 - 0.551, a 60°C tanδ of 0.105 - 0.135, and a rebound value of 34.2% - 39.0%.

[0029] At 0°C, a high tanδ value indicates that the material has a stronger viscous dissipation ability, can absorb more energy through the friction and deformation of molecular chains, enhance the friction hysteresis effect between the tire and the wet road surface, thereby shortening the braking distance and enhancing the wet grip; and the mobility of polymer chain segments decreases at low temperatures. A high tanδ value means that more internal friction is generated when the material deforms, effectively suppressing the slip between the tire tread and the road surface, and improving the driving safety in low-temperature environments;

[0030] At a high temperature of 60 °C, a low tanδ value indicates that the elastic behavior of the material dominates, with less energy loss, reducing the heat accumulation generated by repeated deformation during tire rolling, thereby reducing fuel consumption; and the hysteresis loss is reduced. At high temperatures, the molecular chain mobility increases, and a low tanδ value means that the filler is evenly dispersed and the cross-linking network is stable, avoiding energy waste caused by filler agglomeration or interfacial slip, and improving the fuel economy of the tire.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. Zinc oxide, regenerated silica, and carbon black are extracted from waste tires according to the method of the present invention. By thermally decomposing the organic components of waste tires and using a two-chamber furnace reactor to control the temperature and combustion time to crack the hydrocarbon mixture, combined with steps such as crushing, secondary magnetic separation, acid treatment, and treatment with an iron ion-specific adsorption resin to remove interfering metals and performing secondary cracking to improve the quality of carbon black. At the same time, zinc oxide and regenerated silica are extracted through processes such as alkali solution dissolution and carbon dioxide precipitation. Through the above means, the extraction rates of the three products are effectively improved. Compared with traditional methods, the target products can be obtained more fully from waste tires, realizing the efficient recycling of resources and providing a high-quality and sufficient raw material basis for the preparation of subsequent high-performance rubber materials.

[0033] 2. Based on the optimization of the waste tire extraction process, zinc oxide, regenerated silica, and carbon black raw materials are effectively obtained, thereby improving the resilience, abrasion resistance, and wet skid resistance of the final high-performance rubber material. By reasonably controlling various parameters in the extraction process, such as adjusting the solid content and modulus of the sodium silicate solution and precisely regulating the reaction conditions, the regenerated silica extracted has good properties. The regenerated silica with a high specific surface area is evenly dispersed in the rubber, forming a dense filler network, enhancing the viscous dissipation of the rubber molecular chains, and improving the wet traction, that is, the wet skid resistance; and the optimized extraction process ensures the quality of each component, enabling the rubber material to maintain appropriate elasticity while having a good reinforcing effect, avoiding a decrease in elasticity caused by improper addition of fillers, thereby effectively improving the resilience and abrasion resistance of the rubber material and endowing the high-performance rubber material with good comprehensive properties.

[0034] 3. By reasonably arranging the addition sequence of fillers and additives and the mixing conditions, the performance of high-performance rubber materials has been significantly improved. In the first-stage mixing, partial recycled silica, coupling agents, etc. are added to promote the surface coupling of silane and recycled silica. At the same time, stearic acid, wax, etc. are used to improve the dispersibility, and epoxy soybean oil is used to remove acidic substances. In the second stage, the remaining recycled silica and silane are added to further strengthen the dispersion and coupling. In the third stage, sulfur and accelerators are added at low temperature to avoid early vulcanization. This step-by-step mixing method realizes the good dispersion of fillers and additives, fully exerts the interaction between filler-filler and filler-polymer, and constructs a stable and uniform vulcanization network. Compared with the traditional mixing method, it effectively avoids problems such as uneven filler dispersion, poor interfacial bonding, and early vulcanization, and significantly improves the resilience, wear resistance, and wet skid resistance of rubber materials. Description of the Drawings

[0035] Figure 1 It is a process diagram for the preparation of waste tire extract;

[0036] Figure 2 It is a test result diagram for the wet skid resistance of high-performance rubber materials. Detailed Embodiments

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0038] Please refer to Figures 1 to 2 , the present invention provides a high-performance rubber material containing waste tire extract and its preparation method, and the technical solutions are as follows:

[0039] The substances involved in the present invention are as follows: The waste tires used in S1 are from discarded sedan and electric sedan tires; The random copolymer of butadiene and styrene monomers (SSBR), grade F3438K, is purchased from LG Chem Co., Ltd. of South Korea; The rare earth cis-1,4-polybutadiene rubber (NdBR), grade BR9101, is purchased from China National Petroleum Corporation; The silane coupling agent is coupling agent Si69, grade CG-Si69, purchased from Jiangsu Chenguang Coupling Agent Co., Ltd.; The strongly basic anion exchange resin is purchased from Clear Seas (Beijing) Technology Co., Ltd.; The antioxidant 4020 is purchased from Shandong Xinlongyuan Energy Co., Ltd.; The Fischer-Tropsch wax is purchased from Jiangsu Farl Wax Industry Co., Ltd.; Stearic acid CAS: 57-11-4; Epoxy soybean oil CAS: 8013-07-8; Tetrabenzylthiuram disulfide CAS: 10591-85-2; 2-Mercaptobenzimidazole CAS: 583-39-1.

[0040] Example 1

[0041] S1. Remove the steel wires from the waste tires through a crushing step, and then continue to crush them into rubber blocks with a size of 1 - 5 cm. Feed them into a cracking furnace for cracking at a cracking temperature of 450°C to finally obtain cracking oil and rubber residue.

[0042] S2. Pump the high - temperature cracking oil obtained by cracking to a reactor. The reactor is a double - chamber furnace reactor. It passes through the first chamber at 1600°C and the second chamber at 1300°C in sequence. Air and oxygen are introduced into the combustion chamber. The ratio of air to oxygen in the first chamber is 3:1, and the combustion time is 0.5 s. The ratio of air to oxygen in the second chamber is 5:1, and the combustion time is 3 s. Conduct combustion to produce carbon black. After quenching, separation, and grinding, carbon black is obtained, and the separated tail gas is recycled.

[0043] S3. Use a ring - roll mill to super - finely crush the rubber residue produced by cracking in S1. After the fine powder is removed of iron slag through two - stage magnetic separation, super - fine rubber residue is obtained. The particle size of the super - fine rubber residue is 100 mesh. Then use a cracking gasification furnace to conduct secondary cracking treatment at 400°C to remove the organic rubber hydrocarbons in the rubber residue. Then conduct acidification treatment with a hydrochloric acid solution. The mass fraction of hydrochloric acid is 30%, and the treatment time is 2 h. After solid - liquid separation, a rubber residue filter cake and an acidification liquid precursor are obtained. The magnetic separation intensity of the first - stage magnetic separation is 0.1 T, and the magnetic separation intensity of the second - stage magnetic separation is 0.6 T. The acidification liquid precursor is filtered after being treated with a strongly basic anion exchange resin to obtain an acidification liquid. The mixing mass ratio of the acidification liquid precursor to the strongly basic anion exchange resin is 100:1, and after stirring and mixing, it is left standing for 3 h for treatment.

[0044] S4. The acidification liquid is concentrated by flash drying to a solid content of 15%, and reacted with the by - product mixed alkali solution in S5 until a precipitate appears. After stabilization, solid - liquid separation is carried out, followed by drying, calcination at 500°C for 2 h, and then grinding to obtain zinc oxide.

[0045] S5. Add a 40% caustic soda solution to the rubber residue filter cake. The mass ratio of the alkali solution to the treated material is 15:100. Dissolve and treat it at 100°C and 0.10 MPa for 3 h, and then conduct plate - and - frame filtration to remove the undissolved residual carbon and insoluble ash to obtain a mixed liquid containing sodium silicate solution. Transfer the mixed liquid to a centrifugal atomization tower, introduce carbon dioxide, and react at 75°C and a pH value of 8.0 for 3.5 h. After plate - and - frame filtration, a white carbon black filter cake and a mixed alkali solution are obtained. The white carbon black filter cake is washed and dried to obtain a regenerated white carbon black filter cake, and the mixed alkali solution is recycled for use in S4. The carbon dioxide concentration in the carbon dioxide gas is 90%, and the feeding flow rate is 1.5 L / (min·L reaction liquid).

[0046] S6. After the regenerated white carbon black filter cake is pulped, ground by a ball mill, and dried, regenerated white carbon black is obtained.

[0047] The specific preparation process of the waste tire extract is as follows Figure 1 as shown.

[0048] Examples 1 - 6

[0049] In the examples, the overall treatment steps of the waste tires are the same as those in Example 1, but some parameters have changed, as shown in Tables 1 - 1 to 1 - 3 specifically.

[0050] Table 1 - 1 Preparation conditions of S1 and S2

[0051]

[0052] The concentration of the acid used in Table 1 - 2 is the same.

[0053] Table 1 - 2 Preparation conditions of S3 and S4

[0054]

[0055] Table 1 - 3 Preparation conditions of S5

[0056]

[0057]

[0058] Except for the changes in the parameters and preparation methods listed below, the other preparation methods of Comparative Examples 1 - 11 are the same as those in Example 1.

[0059] The cracking temperature in S1 of Comparative Example 1 is 350 °C.

[0060] The combustion time in the first chamber of S2 in Comparative Example 2 is 1 s, and the combustion time in the second chamber is 8 s.

[0061] (One - stage combustion) In Comparative Example 3, the combustion of S2 is carried out in a furnace black reactor, the calcination temperature is 1000 °C, and the combustion time is 10 s.

[0062] The particle size of the ultra - fine rubber residue in S3 of Comparative Example 4 is 10 mesh.

[0063] In Comparative Example 5, no secondary cracking treatment is carried out for S3.

[0064] In Comparative Example 6, after acidification treatment of S3, it is not mixed and treated with strongly basic anion exchange resin.

[0065] In Comparative Example 7, magnetic separation is not carried out during the process of S3.

[0066] In Comparative Example 8, the solid content of sodium silicate in S5 is 5%, and the modulus is 1.5.

[0067] In Comparative Example 9, the solid content of sodium silicate in S5 is 30%, and the modulus is 3.8.

[0068] In Comparative Example 10S5, the reaction temperature was 150 °C.

[0069] Comparative Example 11 (directly using precipitated silica obtained by extraction instead of recycled precipitated silica): Waste tires were crushed into rubber powder (particle size < 1 mm); precipitated silica was directly separated from the rubber powder by techniques such as air classification and electrostatic separation.

[0070] Washing and drying: Remove residual rubber hydrocarbons on the surface.

[0071] Experimental Example 1

[0072] The extraction rates of zinc oxide, recycled precipitated silica, and carbon black obtained from the above examples and comparative examples were tested. The extraction rate = dry weight of the substance / mass of waste tires × 100%. The test results are shown in Table 2.

[0073] Table 2 Substance extraction results

[0074]

[0075]

[0076] The present invention uses waste tires as the extraction raw material. Under the conditions of Examples 1-6, the extraction rate of zinc oxide in the product is 1.1%-1.9%, the extraction rate of regenerated white carbon black is 16.0%-21.7%, and the extraction rate of carbon black is 22.0%-27.9%. By adjusting the preparation method, the extraction rates of the three products are relatively high; under the conditions of Examples 1-6, the solid content in the sodium silicate solution is 10%-20%, and the modulus is 2.5-3.5. S1 thermally decomposes the organic components (rubber polymers, fibers, and some carbon black binding structures) under low oxygen or inert atmosphere. High temperature decomposes long-chain polymers into smaller volatile hydrocarbons (oil and gas), leaving a solid carbon residue composed of original carbon black, inorganic fillers (zinc oxide, silica, ash), and incompletely decomposed residual carbon; the obtained steel wire is a physical component of the tire and needs to be separated from the rubber matrix; in S2, a two-chamber furnace reactor is set up to adjust the temperature and combustion time of different reaction chambers, and a cracking reaction is carried out on the complex mixture of hydrocarbon cracking oil. Fine carbon black particles are formed through high-temperature thermal cracking and partial combustion, and rapid quenching stops particle growth; in S3, first, crushing is carried out to reduce the size of the carbon residue particles and increase the surface area, which is beneficial to subsequent separation and chemical treatment. Through secondary magnetic separation and acid treatment, and finally, treatment with an iron ion-specific adsorption resin is used to remove interfering metals; the type of acid is optimized. Among them, hydrochloric acid has the lowest cost and good treatment effect; sulfuric acid reacts with metal oxides to form sulfates, but the reaction of sulfuric acid may generate more heat, and the solubility of sulfates may be relatively low, especially when treating metals such as calcium, precipitates may be formed; nitric acid has strong oxidizing properties, which can cause further oxidation of organic substances, generate harmful gases, and has a high cost; phosphoric acid is a medium-strong acid with low corrosiveness, but the reaction rate is slow and the cost is high. And secondary cracking / gasification is carried out: at a moderate temperature, the residual volatile organic compounds and sulfur in the carbon residue are removed, and the carbon residue may be further carbonized to improve the quality of the carbon; in S4, zinc is recovered by wet method. By adding alkali, the pH is increased to provide hydroxide ions to precipitate zinc ions in the acidified solution. Zinc hydroxide and zinc carbonate precipitates are separated, dried, and heated and calcined to be converted into zinc oxide, and the alkali liquor flow of the S5 process is used to increase the material saving amount; in S5, silica is extracted from the carbon residue by dissolving with alkali liquor, and then precipitated with carbon dioxide to form amorphous silica. The hot concentrated caustic soda solution dissolves the silicates present in the tire ash / carbon residue, including metal silicates, to form soluble sodium silicate, and the solid residue (unreacted carbon, undissolved ash) is filtered out; carbon dioxide is introduced into the sodium silicate solution, resulting in the precipitation of silicic acid, which is then dehydrated and aggregated into amorphous silica particles, that is, regenerated white carbon black; the by-product is sodium carbonate solution, which can be recycled to the alkali flow of S4; finally, grinding is carried out to obtain the three extracted final products.

[0077] In Comparative Example 1, the organic matter residue in the low-temperature pyrolyzed glue residue was difficult to acidify, resulting in a reduced extraction rate; in Comparative Example 2, the combustion time was too long, the carbon black was over-oxidized, generating gases such as carbon dioxide, and the yield decreased; in Comparative Example 3, the single-chamber furnace could not form aggregates, reducing the extraction rates of the three components; in Comparative Example 4, the coarse particle size led to incomplete acidification reaction, reducing the extraction efficiency of zinc oxide and regenerated silica; in Comparative Example 5, without secondary pyrolysis, the hydrocarbon content in the glue residue interfered with acidification, and the extraction rate of zinc oxide decreased significantly; in Comparative Example 6, without the treatment of mixing with strong basic anion exchange resin, the resin was mainly used to remove iron ions, but it also had a certain adsorption effect on zinc ions. Omitting this step increased the extraction rate of the final zinc oxide, and the contents of the other two substances did not change significantly; in Comparative Example 7, without magnetic separation, the results were not significantly different from those of Example 1; in Comparative Examples 8 and 9, the solid content was too low or too high, with the modulus being 1.5 and 3.8 respectively, and there was no significant effect on the extraction of substances; in Comparative Example 10, too high temperature and pressure damaged the sodium silicate structure, hindering the formation of regenerated silica.

[0078] Preparation Example 1

[0079] The preparation method of the high-performance rubber material is as follows: First-stage mixing: 90 Kg of SSBR and 10 Kg of NdBR are uniformly mixed at 60 rpm. Add 1 / 2 (compared with the total mass of the regenerated silica) of the regenerated silica, 2 / 3 (compared with the total mass of the coupling agent) of the silane coupling agent, and 3.5 phr of carbon black. Adjust the rotation speed to 65 rpm. After mixing for 2 min, add a dispersant, 3.0 phr of stearic acid, 2.5 phr of Fischer-Tropsch wax, and 2.5 phr of epoxidized soybean oil, and mix for 2 min. Adjust the temperature to 130 °C and mix at 75 rpm for 180 s. Finally, discharge the rubber at 127 °C to obtain the first-stage mixing material; the total addition amount of the regenerated silica is 30 phr, and the total addition amount of the silane coupling agent is 5.0 phr;

[0080] Second-stage mixing: The first-stage mixing material is stirred at 60 rpm for 1 min, then add the remaining regenerated silica and silane coupling agent, 5.2 phr of zinc oxide, and 0.3 phr of antioxidant 4020. After stirring for 4 min, discharge the rubber at 110 °C for 1 min to obtain the second-stage mixing material;

[0081] Third-stage mixing: The second-stage mixing material is stirred at 45 rpm for 1 min, then add 2.8 phr of sulfur and 1.2 phr of accelerator. After stirring for 3 min, discharge the rubber, press it into sheets, cool it, and place it at room temperature for 20 h. Finally, vulcanize it at 160 °C and 15 Mpa for 15 min to obtain the high-performance rubber material. The zinc oxide, regenerated silica, and carbon black used are all prepared according to the preparation method of Example 1.

[0082] Preparation Examples 2-9 respectively correspond to the zinc oxide, regenerated silica, and carbon black products prepared according to Examples 2-6, Comparative Example 6, 7, and 11.

[0083] Example 2

[0084] The high-performance rubber materials obtained in Preparation Examples 1-9 were subjected to performance tests, mainly for resilience, wear resistance and wet skid resistance. A dynamic mechanical analyzer (DMA) was used to perform temperature scanning in double cantilever mode. The test conditions were: frequency 10 Hz, temperature range -60 to 80 ° C, heating rate 2 K min, and tan δ at 0 ° C and 60 ° C was recorded. Tan δ is the loss factor, requiring 0 ° C tan δ ≥ 0.35 and 60 ° C tan δ ≤ 0.15; and the rebound value and DIN wear value were tested. The test results are shown in Table 3.

[0085] Table 3 Resilience, wear resistance and wet skid resistance test results

[0086]

[0087] Under the condition that the overall preparation method of the high-performance rubber material is consistent, the preparation methods of the zinc oxide, regenerated white carbon black and carbon black used therein are adjusted, so that the high-performance rubber material has good resilience, wear resistance and wet skid resistance. The raw materials obtained by the preparation method of Examples 1-6 are used to further obtain the high-performance rubber materials of Preparation Examples 1-6, wherein 0°C tanδ is 0.353-0.551, 60°C tanδ is 0.105-0.143, the rebound value is 32.8%-39.0%, and the DIN wear loss is 102.3mm 3 -115.4mm 3 , with good comprehensive performance. The high 0℃ tanδ comes from the high specific surface area and uniform dispersion of regenerated silica, forming a dense filler network, enhancing the viscous dissipation of the rubber molecular chain, and improving wet grip. In the scheme, the sodium silicate modulus is adjusted to a reasonable range, and the carbon dioxide flow rate is regulated, so that the regenerated silica has good performance. Excessive addition of regenerated silica and carbon black will reduce the elasticity of the rubber material, but the present invention reasonably adjusts the dosage to obtain a high-performance rubber material with good elasticity, low wear and high wear resistance. Preparation Examples 7 and 8 are carried out according to the methods of Comparative Examples 6 and 7, respectively, and the comprehensive performance of the high-performance rubber material obtained is reduced. Not mixing with a strong alkaline anion exchange resin and not performing magnetic separation will cause the residue of interfering metals to be mixed in the raw materials, reducing the crosslinking and vulcanization degree of the rubber material, resulting in a decrease in the final performance. Preparation Example 9 uses directly extracted regenerated silica to prepare a high-performance rubber material. The regenerated silica loses its performance during long-term use and has poor reinforcement. Therefore, the overall performance of the obtained high-performance rubber material is reduced to the minimum.

[0088] Preparation Example 10-12

[0089] Different from Preparation Example 2, the following preparation conditions were changed, as specifically shown in Table 4.

[0090] Table 4 Preparation Conditions of High-Performance Rubber Materials

[0091]

[0092] For the preparation comparison, except for the conditions listed below, other preparation methods were the same as those in Preparation Example 2.

[0093] In Preparation Comparison 1, all the regenerated silica and silane coupling agent were added during the first-stage mixing process without a segmented addition process.

[0094] In Preparation Comparison 2, the amount of regenerated silica used was 60 phr, and the amount of zinc oxide used was 10 phr.

[0095] In Preparation Comparison 3, no silane coupling agent was added.

[0096] In Preparation Comparison 4, the discharge temperature of the first-stage mixing was 140 °C, the discharge temperature of the second-stage mixing was 120 °C, and the discharge temperature of the third-stage mixing was 100 °C.

[0097] In Preparation Comparison 5, after pressing and cooling during the three-stage mixing process, it was not left standing at room temperature and was directly vulcanized.

[0098] In Preparation Comparison 6, instead of using three-stage mixing, all the raw materials were directly added during the first-stage mixing process. The reaction and discharge temperatures remained unchanged. After mixing, it was placed at room temperature for 20 h, and finally vulcanized at 160 °C and 15 Mpa for 15 min to obtain the high-performance rubber material.

[0099] Experimental Example 3

[0100] The high-performance rubber materials obtained in Preparation Example 2, 10 - 12 and Preparation Comparisons 1 - 5 were subjected to performance tests. The test method was carried out according to the method in Experimental Example 2, and the test results are shown in Table 5 and Figure 2 as follows.

[0101] Table 5 Performance Test Results of Preparation Example 2, 10 - 12 and Preparation Comparisons 1 - 6

[0102]

[0103]

[0104] For the high-performance rubber materials of Preparation Example 2, 10 - 12, among which, the tanδ at 0 °C was 0.463 - 0.551, the tanδ at 60 °C was 0.105 - 0.135, the resilience value was 34.2% - 39.0%, and the DIN abrasion was 102.3 mm 3 -112.7 mm 3Through the multi-stage mixing process, good dispersion of fillers and additives is achieved, filler-filler and filler-polymer interactions are developed, and early vulcanization is prevented by adding the vulcanization system in the final low-temperature stage. In the first stage of mixing, part of the regenerated silica and coupling agent are added to achieve the coupling of silane with the surface of the regenerated silica under elevated temperature conditions. Stearic acid and wax are used to improve dispersibility, which is beneficial to the wetting and dispersion of fillers. The addition of epoxidized soybean oil is used to remove residual acidic substances to avoid adverse effects; the remaining regenerated silica and silane are added in the second stage, which helps further dispersion and coupling; the added zinc oxide is an activator for sulfur vulcanization, which forms zinc stearate with the stearic acid in the first stage, thereby improving the final performance; in the third stage of mixing, sulfur and accelerators are added at a lower discharge temperature to introduce the vulcanization system without causing early vulcanization (scorch) procedures. In Preparation Comparison 1, regenerated silica and silane coupling agent were added at one time, resulting in uneven filler dispersion, poor interface bonding, and increased hysteresis loss; in Preparation Comparison 2, regenerated silica and zinc oxide were excessive, the filler network was too dense, the elasticity decreased, and the rolling resistance increased significantly; in Preparation Comparison 3, no silane coupling agent was added: the regenerated silica had poor bonding with the rubber matrix, severe interface slippage, and a sharp drop in wear resistance; in Preparation Comparison 4, the discharge temperature was too high, causing partial thermal degradation of the rubber, loose cross-linking network, and deterioration of dynamic performance; in Preparation Comparison 5, direct vulcanization was performed without standing: the vulcanizing agent was unevenly distributed, the cross-linking density fluctuated, and the resilience and wear resistance decreased simultaneously; in Preparation Comparison 6, a one-stage mixing method was adopted, which affected the dispersion of the filler and the formation of the vulcanization network, thereby reducing the dynamic mechanical properties.

[0105] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Preparation method of high-performance rubber material containing waste tire extract, characterized in that: The preparation method is as follows: First-stage mixing: Add recycled silica, coupling agent, and carbon black to raw rubber, mix, and discharge the rubber to obtain a first-stage mixed material; Second-stage mixing: Add the remaining recycled silica, the coupling agent, and zinc oxide to the first-stage mixed material, mix, and discharge the rubber to obtain a second-stage mixed material; Third-stage mixing: Add sulfur and accelerator to the second-stage mixed material, mix, discharge the rubber, and let it stand for vulcanization to obtain the high-performance rubber material; The waste tire extract is composed of the recycled silica, the carbon black, and the zinc oxide.

2. The preparation method of the high-performance rubber material containing waste tire extract according to claim 1, characterized in that: The total amount of recycled silica used in the first-stage mixing and the second-stage mixing is 24 - 46 phr; the amount of zinc oxide used is 3.5 - 5.2 phr; the total amount of coupling agent used in the first-stage mixing and the second-stage mixing is 3.6 - 5.4 phr; the amount of carbon black used is 2.5 - 5 phr; the amount of zinc oxide used is 3.5 - 10 phr.

3. The preparation method of the high-performance rubber material containing waste tire extract according to claim 1, characterized in that: The preparation method of the carbon black is as follows: Crush the waste tire to remove the steel wire, continue to crush it, and pyrolyze it at 450 - 550 °C to obtain pyrolysis oil and rubber residue; The pyrolysis oil enters a double-chamber furnace reactor, burns successively through a first chamber at 1500 - 1700 °C and a second chamber at 1000 - 1300 °C, is quenched, separated, and ground to obtain the carbon black.

4. The preparation method of the high-performance rubber material containing waste tire extract according to claim 3, characterized in that: The preparation method of the zinc oxide is as follows: Crush the rubber residue, obtain superfine rubber residue after two-stage magnetic separation; the superfine rubber residue is subjected to secondary pyrolysis treatment at 300 - 500 °C; then perform acid treatment for 2 - 4 h to separate a rubber residue filter cake and an acidified liquid precursor; the acidified liquid precursor is treated with an anion exchange resin to obtain an acidified liquid; the particle size of the superfine rubber residue is 100 - 400 mesh; the acid agent used for the acid treatment is one of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; The acidified liquid is concentrated to a solid content of 15% - 18%, mixed with an alkali solution for reaction, and the generated precipitate is calcined at 450 - 600 °C for 2 h and then ground to obtain the zinc oxide.

5. The preparation method of the high-performance rubber material containing waste tire extract according to claim 4, characterized in that: The preparation method of the recycled silica is as follows: Add caustic soda solution to the rubber residue filter cake, dissolve and treat it at 50 - 180 °C and 0.05 - 1.3 MPa for 0.1 - 5 h, and perform plate-and-frame filtration to obtain a mixed liquid containing sodium silicate solution; introduce carbon dioxide into the mixed liquid, react at 40 - 98 °C for 1 - 5 h, and generate a silica filter cake and the mixed alkali solution through plate-and-frame filtration; The mixed alkali solution is recycled; the silica filter cake is washed and dried to obtain a recycled silica filter cake; the recycled silica filter cake is ground to obtain the recycled silica; the solid content of sodium silicate in the mixed liquid is 10% - 20%, and the modulus is 2.5 - 3.

5.

6. The preparation method of the high-performance rubber material containing waste tire extract according to claim 4, characterized in that: The two-stage magnetic separation is the first-stage magnetic separation and the second-stage magnetic separation; the magnetic separation intensity of the first-stage magnetic separation is 0.1 - 0.3 T; the magnetic separation intensity of the second-stage magnetic separation is 0.5 - 0.8 T.

7. The preparation method of the high-performance rubber material containing waste tire extract according to claim 5, characterized in that: The flow rate of carbon dioxide introduced is 0.5 - 2.0 L / min; the pH value of the reaction system when carbon dioxide is introduced is 7.5 - 9.

5.

8. High-performance rubber material containing waste tire extract, characterized in that: The high-performance rubber material is prepared by the preparation method described in any one of claims 1-7; the raw materials for preparing the high-performance rubber material include the waste tire extract, raw rubber, coupling agent, stearic acid, Fischer-Tropsch wax, epoxidized soybean oil, sulfur and accelerator; the waste tire extract includes regenerated silica, carbon black and zinc oxide; the raw rubber is obtained by mixing a random copolymer of butadiene and styrene monomers and rare earth cis-polybutadiene rubber in a mass ratio of 9:1; the high-performance rubber material has a tanδ value of 0.353-0.551 at 0 °C, a tanδ value of 0.105-0.135 at 60 °C, and a resilience value of 34.2%-39.0%.

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