Environment-friendly high-strength recycled rubber composite formula and production process thereof

Abstract

This invention discloses a composite formulation and production process for environmentally friendly, high-strength reclaimed rubber, relating to the field of rubber regeneration technology. The composite formulation includes 100 parts truck tire tread rubber powder, 2.8-3.9 parts high-efficiency composite activator, 10-15 parts composite environmentally friendly softener, 2.7-3.6 parts anti-aging reinforcing agent, and 0.3-0.5 parts deodorizer. The production process includes rubber powder pretreatment, rubber compound premixing, segmented pre-stirring desulfurization, screw extrusion desulfurization, segmented cooling, precision filtration, and refining molding. This invention uses high-quality truck tire tread rubber powder, combined with the synergistic effect of high-efficiency composite activator, composite environmentally friendly softener, and anti-aging reinforcing agent, significantly improving the surface activity and dispersibility of the rubber powder. Combined with the segmented pre-stirring and screw extrusion dual-effect desulfurization process, it improves the tensile strength of the reclaimed rubber. The polycyclic aromatic hydrocarbon content is controlled throughout the entire process from formulation to manufacturing, producing reclaimed rubber with both high strength and environmental friendliness, meeting the needs of the high-end market.

Description

Technical Field

[0001] This invention relates to the field of rubber recycling technology, and in particular to a composite formulation of environmentally friendly high-strength recycled rubber and its production process. Background Technology

[0002] In the traditional rubber recycling process, due to limitations in formulation and technology, there are problems such as low strength, poor elasticity, excessive polycyclic aromatic hydrocarbon content, and uneven desulfurization of recycled rubber. At the same time, the products generally have an irritating odor. Most environmentally friendly recycled rubber products are still mainly low-to-mid-end, with tensile strength generally below 12MPa, which cannot meet the urgent needs of high-end tires, engineering rubber and other fields for high-strength and high-elongation materials. Summary of the Invention

[0003] The purpose of this invention is to provide a composite formulation and production process for environmentally friendly, high-strength reclaimed rubber. It utilizes high-quality truck tire tread rubber powder, combined with a highly efficient composite activator, a composite environmentally friendly softener, and an anti-aging reinforcing agent to significantly improve the surface activity and dispersibility of the rubber powder. By combining a dual-effect desulfurization process of segmented pre-stirring desulfurization and screw extrusion desulfurization, the tensile strength of the reclaimed rubber is greatly enhanced. The polycyclic aromatic hydrocarbon content is controlled throughout the entire process, from formulation to manufacturing, producing reclaimed rubber that combines high strength and environmental friendliness, meeting the needs of the high-end market.

[0004] The above-mentioned technical objective of the present invention is achieved through the following technical solution: An environmentally friendly, high-strength recycled rubber compound formulation, based on 100 parts by weight of truck tire tread rubber powder, includes the following components: Truck tire tread rubber powder: 100 parts, particle size 20-40 mesh, metal and fiber impurity removal rate ≥99.5%; Highly efficient composite activator: 2.8-3.9 parts, composed of 0.3-0.5 parts of 2-mercaptobenzothiazole, 0.4-0.6 parts of 2-mercaptobenzoimidazolium, 0.7-0.9 parts of modified nano magnesium oxide, 1.2-1.6 parts of modified nano zinc oxide, and 0.2-0.3 parts of triethanolamine; Composite environmentally friendly softener: 10-15 parts, composed of 6-8 parts of environmentally friendly aromatic oil, 2-3 parts of pine tar, and 2-4 parts of methyl oleate; Anti-aging and reinforcing agent: 2.7-3.6 parts, composed of 0.5-0.7 parts phenolic antioxidant, 0.7-0.9 parts stearic acid, and 1.5-2.0 parts modified nano-silica; Odor remover: 0.3-0.5 parts activated charcoal powder.

[0005] Furthermore, the modified nano-magnesium oxide is modified with stearic acid at a mass ratio of 1:0.08, the modified nano-zinc oxide is modified with a silane coupling agent at a mass ratio of 1:0.1, and the modified nano-silica is modified with a silane coupling agent at a mass ratio of 1:0.12.

[0006] A production process for environmentally friendly, high-strength recycled rubber, using the above-mentioned composite formula, specifically includes the following steps: S1. Pretreatment of rubber powder: The raw materials of truck tire tread rubber powder are subjected to coarse crushing, washing, drying, fine crushing and three-stage impurity removal in sequence to obtain 20-40 mesh truck tire tread rubber powder. S2. Rubber premixing: The pretreated truck tire tread rubber powder, high-efficiency composite activator, composite environmentally friendly softener, anti-aging reinforcing agent and deodorizer are added to the premixer in proportion and mixed thoroughly. S3. Segmented pre-mixing desulfurization: The pre-mixed rubber compound is added into a 10 cubic meter pre-mixing desulfurization tank, and pre-mixing desulfurization is carried out by segmented heating and pressurization. S4. Screw extrusion desulfurization: The pre-mixed desulfurized rubber compound is fed into the screw extruder for segmented temperature-controlled desulfurization. S5. Segmented cooling: The desulfurized rubber compound undergoes primary cooling and secondary cooling sequentially. S6. Precision filtration: The cooled rubber material is sent into a precision filter for multi-stage filtration to remove residual impurities. S7. Refining and molding: The filtered rubber material is fed into a refining machine for molding, followed by weighing, packaging and stacking.

[0007] Further, in step S1, the particle size of the truck tire tread rubber powder raw material after coarse crushing is 8 mesh, the cleaning is performed by ultrasonic cleaning for 15-20 minutes, the drying temperature is 80-90℃, the drying time is 10-15 minutes, and the particle size after fine crushing is 20-40 mesh.

[0008] Furthermore, the three-stage impurity removal in step S1 includes magnetic separation, air separation and electrostatic separation performed sequentially, and the removal rate of metal and fiber impurities in the three-stage impurity removal is ≥99.5%.

[0009] Furthermore, in step S2, the rotation speed of the premixer is 600-800 r / min, the premixing temperature is 80-90℃, and the premixing time is 10-15 min.

[0010] Further, in step S3, the segmented heating and pressurization includes a preheating stage, a desulfurization stage, and a heat preservation stage. The temperature of the preheating stage is 150-160℃, the pressure is 1.2-1.4MPa, and the time is 20-25min. The temperature of the desulfurization stage is 190-200℃, the pressure is 2.0-2.2MPa, and the time is 30-35min. The temperature of the heat preservation stage is 170-180℃, the pressure is 1.6-1.8MPa, and the time is 10-15min.

[0011] Furthermore, in step S4, the segmented temperature-controlled desulfurization includes a feeding section, a compression section, a desulfurization section, and a discharge section, with operating temperatures of 160-170℃, 180-190℃, 200-210℃, and 170-180℃ respectively, and the screw speed of the screw extruder is 60-70 r / min.

[0012] Furthermore, in step S5, the temperature of the first-stage cooling is 120-130℃ and the cooling time is 2-3 minutes, and the temperature of the second-stage cooling is 70-80℃ and the cooling time is 3-5 minutes.

[0013] Furthermore, in step S6, the multi-stage filtration consists of 30-mesh filter and 100-mesh filter.

[0014] In summary, the present invention has the following beneficial effects: 1. This invention uses high-quality truck tire tread rubber powder with a purification rate of ≥99.5%, combined with a high-efficiency composite activator, a composite environmentally friendly softener, and an anti-aging reinforcing agent. It also incorporates a dual-effect desulfurization process of segmented pre-stirring desulfurization and screw extrusion desulfurization to greatly improve the tensile strength of reclaimed rubber. This produces reclaimed rubber that combines high strength and environmental friendliness, with a tensile strength of ≥16MPa, meeting the needs of the high-end market. 2. This invention uses a composite environmentally friendly softener and deodorizer, pre-stirred desulfurization with segmented heating and pressurization, screw extrusion desulfurization with segmented temperature control, and controls the polycyclic aromatic hydrocarbon content throughout the entire process from formulation to process, thereby reducing product odor. The total polycyclic aromatic hydrocarbon content is <150ppm / kg, which is far below the national standard limit and meets environmental protection requirements. 3. In this invention, pre-stirring desulfurization and screw extrusion desulfurization are combined to desulfurize the rubber compound multiple times. Pre-stirring allows for segmented heating and pressurization, while screw extrusion desulfurization has segmented temperature control, which effectively ensures the uniformity of desulfurization of the rubber compound and avoids incomplete or excessive desulfurization. 4. The present invention employs optimized steps such as segmented cooling and multi-stage precision filtration to prevent internal stress from causing cracking in the product, thereby further improving the stability of product quality. Attached Figure Description

[0015] Figure 1This is a flowchart of a production process for environmentally friendly high-strength recycled rubber according to the present invention; Figure 2 This is a performance comparison chart of Embodiments 1 to 8 of the present invention with Comparative Examples 1 and 2. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0017] Example 1: An environmentally friendly, high-strength recycled rubber compound formulation, based on 100 parts by weight of truck tire tread rubber powder, includes the following components: Truck tire tread rubber powder: 100 parts, made from waste truck tire tread rubber as raw material. After pretreatment, the particle size is controlled at 20-40 mesh, and the removal rate of metal and fiber impurities is ≥99.5% to ensure the purity of the raw material.

[0018] High-efficiency composite activator: 2.8-3.9 parts, composed of 0.3-0.5 parts of 2-mercaptobenzothiazole, 0.4-0.6 parts of 2-mercaptobenzimidazole, 0.7-0.9 parts of modified nano-magnesium oxide, 1.2-1.6 parts of modified nano-zinc oxide, and 0.2-0.3 parts of triethanolamine. The modified nano-magnesium oxide is modified with stearic acid at a mass ratio of 1:0.08, and the modified nano-zinc oxide is modified with a silane coupling agent at a mass ratio of 1:0.1. 2-mercaptobenzothiazole and 2-mercaptobenzimidazole work synergistically to break sulfur, promote the cleavage of cross-linking bonds, improve desulfurization efficiency, and increase the tensile strength of the product. Modified nano-magnesium oxide and modified nano-silica enhance compatibility with the rubber powder and strengthen the activation effect. Triethanolamine acts as a co-activator, promoting the dispersion of each activating component and further improving the desulfurization effect.

[0019] Composite environmentally friendly rubber softener: 10-15 parts, composed of 6-8 parts environmentally friendly aromatic oil, 2-3 parts pine tar, and 2-4 parts methyl oleate. The environmentally friendly aromatic oil and pine tar work synergistically to penetrate the rubber network, causing it to swell and lowering the glass transition temperature. The environmentally friendly aromatic oil has an extremely low polycyclic aromatic hydrocarbon content, while the pine tar has a certain tackifying and reinforcing effect, and the methyl oleate can reduce odor and improve elongation.

[0020] Anti-aging reinforcing agent: 2.7-3.6 parts, composed of 0.5-0.7 parts phenolic antioxidant, 0.7-0.9 parts stearic acid, and 1.5-2.0 parts modified nano-silica; the modified nano-silica is modified by a silane coupling agent with a modification mass ratio of 1:0.12. The phenolic antioxidant can improve the anti-aging performance of the product and extend its service life. Stearic acid, as a lubricant and activator, improves the flowability of the rubber compound and promotes the function of the activator. The modified nano-silica has excellent reinforcing effect, significantly improving the tensile strength and hardness of reclaimed rubber. The phenolic antioxidant is one or more of antioxidant 264, antioxidant 1010, and antioxidant 1076; in Examples 1 to 8 of this invention, antioxidant 1010 is selected.

[0021] Odor remover: 0.3-0.5 parts activated carbon powder. Activated carbon powder effectively adsorbs odors generated during the desulfurization process by utilizing its adsorption properties.

[0022] In this embodiment, the specific amounts of each component are as follows: The product contains 100 parts truck tire tread rubber powder, 2.8 parts high-efficiency composite activator (specifically 0.3 parts 2-mercaptobenzothiazole, 0.4 parts 2-mercaptobenzoimidazolium, 0.7 parts modified nano magnesium oxide, 1.2 parts modified nano zinc oxide, and 0.2 parts triethanolamine), 10 parts composite environmentally friendly softener (specifically 6 parts environmentally friendly aromatic oil, 2 parts pine tar, and 2 parts methyl oleate), 2.7 parts anti-aging and reinforcing agent (specifically 0.5 parts phenolic antioxidant, 0.7 parts stearic acid, and 1.5 parts modified nano silica), and 0.3 parts activated carbon powder as deodorizer.

[0023] A production process for environmentally friendly, high-strength recycled rubber, employing the aforementioned composite formula, such as... Figure 1 As shown, the specific steps include the following: S1. Pretreatment of Rubber Powder: The raw material of truck tire tread rubber powder is subjected to coarse crushing, washing, drying, fine crushing, and three-stage impurity removal treatment in sequence to obtain 20-40 mesh truck tire tread rubber powder. Specifically, the particle size of the raw material after coarse crushing is 8 mesh; washing is performed using ultrasonic cleaning for 15-20 minutes; drying temperature is 80-90℃; drying time is 10-15 minutes; and the particle size after fine crushing is 20-40 mesh. The three-stage impurity removal includes sequential magnetic separation, air separation, and electrostatic separation, with a removal rate of ≥99.5% for metal and fiber impurities. In this step, the washing and drying steps are inserted after coarse crushing and before fine crushing to remove some impurities and reduce moisture content before fine crushing, ensuring that the fine crushing directly yields relatively qualified rubber powder. The three-stage impurity removal ensures the effectiveness of impurity removal and guarantees the high purity of the obtained truck tire tread rubber powder.

[0024] S2. Rubber compound premixing: The pretreated truck tire tread rubber powder, high-efficiency composite activator, composite environmentally friendly softener, anti-aging reinforcing agent, and deodorizer are added to a premixer in the specified proportions and thoroughly mixed to achieve uniform dispersion and mixing of each component, avoiding local concentrations that are too high or too low, which would affect the effectiveness of each component. The premixer speed is 600-800 r / min, the premixing temperature is 80-90℃, and the premixing time is 10-15 min.

[0025] S3. Segmented Pre-mixing Desulfurization: The premixed rubber compound is added to a 10 cubic meter pre-mixing desulfurization tank, and pre-mixing desulfurization is carried out through segmented heating and pressurization. The segmented heating and pressurization includes a preheating stage, a desulfurization stage, and a holding stage. The preheating stage has a temperature of 150-160℃, a pressure of 1.2-1.4 MPa, and a time of 20-25 min; the desulfurization stage has a temperature of 190-200℃, a pressure of 2.0-2.2 MPa, and a time of 30-35 min; and the holding stage has a temperature of 170-180℃, a pressure of 1.6-1.8 MPa, and a time of 10-15 min. Segmented heating and pressurization achieves uniform desulfurization, avoiding incomplete or excessive desulfurization and improving the tensile strength of the product.

[0026] S4. Screw Extrusion Desulfurization: The pre-mixed desulfurized rubber compound is fed into a screw extruder for segmented temperature-controlled desulfurization. This segmented temperature-controlled desulfurization includes a feeding section, a compression section, a desulfurization section, and a discharge section, with operating temperatures of 160-170℃, 180-190℃, 200-210℃, and 170-180℃ respectively. The screw speed of the screw extruder is 60-70 r / min. Using segmented temperature control for further desulfurization, compared to single-stage desulfurization, the combined effect of segmented pre-mixed desulfurization and screw extrusion desulfurization better ensures desulfurization uniformity and improves the tensile properties of the product.

[0027] S5. Segmented Cooling: The desulfurized rubber compound undergoes primary and secondary cooling sequentially to avoid rapid cooling, which can easily lead to internal stress and prevent product cracking. The primary cooling temperature is 120-130℃, and the cooling time is 2-3 minutes. The secondary cooling temperature is 70-80℃, and the cooling time is 3-5 minutes.

[0028] S6. Precision filtration: The cooled rubber material is fed into a precision filter and undergoes multi-stage filtration using 30-mesh and 100-mesh screens to remove residual impurities and further improve product quality.

[0029] S7. Refining and Molding: The filtered rubber material is fed into a refining machine for molding to obtain environmentally friendly high-strength recycled rubber, which is then weighed, packaged, and stacked.

[0030] In this embodiment, the specific process parameters for steps S1-S6 are as follows: In S1, the particle size after coarse crushing is 8 mesh, the washing is ultrasonic cleaning for 20 minutes, the drying temperature is 90℃ and the drying time is 15 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0031] In S2, the premixer rotates at 800 r / min, the premixing temperature is 90℃, and the premixing time is 15 min.

[0032] In S3, the preheating stage has a temperature of 160℃, a pressure of 1.4MPa, and a time of 25min; the desulfurization stage has a temperature of 200℃, a pressure of 2.2MPa, and a time of 35min; and the heat preservation stage has a temperature of 180℃, a pressure of 1.8MPa, and a time of 15min.

[0033] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization are 170℃, 190℃, 210℃, and 180℃ respectively, and the screw speed of the screw extruder is 70r / min.

[0034] In S5, the primary cooling temperature is 130℃ and the cooling time is 3 minutes, while the secondary cooling temperature is 80℃ and the cooling time is 5 minutes.

[0035] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0036] Example 2: A composite formulation of environmentally friendly, high-strength recycled rubber differs from Example 1 in that the specific amounts of each component in this example are as follows: The product contains 100 parts truck tire tread rubber powder, 3.35 parts high-efficiency composite activator (specifically 0.4 parts 2-mercaptobenzothiazole, 0.5 parts 2-mercaptobenzoimidazolium, 0.8 parts modified nano magnesium oxide, 1.4 parts modified nano zinc oxide, and 0.25 parts triethanolamine), 12.5 parts composite environmentally friendly softener (specifically 7 parts environmentally friendly aromatic oil, 2.5 parts pine tar, and 3 parts methyl oleate), 3.1 parts anti-aging and reinforcing agent (specifically 0.6 parts phenolic antioxidant, 0.8 parts stearic acid, and 1.7 parts modified nano silica), and 0.4 parts activated carbon powder as deodorizer.

[0037] A production process for environmentally friendly high-strength recycled rubber differs from the previous embodiment in that it employs the composite formulation of this embodiment, and the specific process parameters for steps S1-S6 in this embodiment are as follows: In S1, the particle size after coarse crushing is 8 mesh, the washing is ultrasonic cleaning for 18 minutes, the drying temperature is 85℃, the drying time is 12 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0038] In S2, the premixer speed is 700 r / min, the premixing temperature is 85℃, and the premixing time is 12 min.

[0039] In S3, the preheating stage has a temperature of 155℃, a pressure of 1.3MPa, and a time of 22min; the desulfurization stage has a temperature of 195℃, a pressure of 2.1MPa, and a time of 32min; and the heat preservation stage has a temperature of 175℃, a pressure of 1.7MPa, and a time of 12min.

[0040] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization are 165℃, 185℃, 205℃, and 175℃ respectively, and the screw speed of the screw extruder is 65r / min.

[0041] In S5, the primary cooling temperature is 125℃ and the cooling time is 2 minutes, while the secondary cooling temperature is 75℃ and the cooling time is 4 minutes.

[0042] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0043] Example 3: A composite formulation of environmentally friendly, high-strength recycled rubber differs from Example 1 in that the specific amounts of each component in this example are as follows: The product contains 100 parts of truck tire tread rubber powder, 3.9 parts of a high-efficiency composite activator (specifically 0.5 parts of 2-mercaptobenzothiazole, 0.6 parts of 2-mercaptobenzoimidazolium, 0.9 parts of modified nano magnesium oxide, 1.6 parts of modified nano zinc oxide, and 0.3 parts of triethanolamine), 15 parts of a composite environmentally friendly softener (specifically 8 parts of environmentally friendly aromatic oil, 3 parts of pine tar, and 4 parts of methyl oleate), 3.6 parts of an anti-aging and reinforcing agent (specifically 0.7 parts of phenolic antioxidant, 0.9 parts of stearic acid, and 2.0 parts of modified nano silica), and 0.5 parts of activated carbon powder as a deodorizer.

[0044] A production process for environmentally friendly high-strength recycled rubber differs from the previous embodiment in that it employs the composite formulation of this embodiment, and the specific process parameters for steps S1-S6 in this embodiment are as follows: In S1, the particle size after coarse crushing is 8 mesh, the cleaning is performed by ultrasonic cleaning for 18 minutes, the drying temperature is 85℃, the drying time is 13 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0045] In S2, the premixer speed is 700 r / min, the premixing temperature is 85℃, and the premixing time is 13 min.

[0046] In S3, the preheating stage has a temperature of 155℃, a pressure of 1.3MPa, and a time of 23min; the desulfurization stage has a temperature of 195℃, a pressure of 2.1MPa, and a time of 33min; and the heat preservation stage has a temperature of 175℃, a pressure of 1.7MPa, and a time of 13min.

[0047] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization are 165℃, 185℃, 205℃, and 175℃ respectively, and the screw speed of the screw extruder is 65r / min.

[0048] In S5, the primary cooling temperature is 125℃ and the cooling time is 3 minutes, while the secondary cooling temperature is 75℃ and the cooling time is 4 minutes.

[0049] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0050] Example 4: A composite formulation of environmentally friendly, high-strength recycled rubber differs from Example 1 in that the specific amounts of each component in this example are as follows: The product contains 100 parts truck tire tread rubber powder, 3.3 parts high-efficiency composite activator (specifically 0.5 parts 2-mercaptobenzothiazole, 0.4 parts 2-mercaptobenzoimidazolium, 0.9 parts modified nano magnesium oxide, 1.2 parts modified nano zinc oxide, and 0.3 parts triethanolamine), 13 parts composite environmentally friendly softener (specifically 8 parts environmentally friendly aromatic oil, 2 parts pine tar, and 3 parts methyl oleate), 3.3 parts anti-aging and reinforcing agent (specifically 0.6 parts phenolic antioxidant, 0.9 parts stearic acid, and 18 parts modified nano silica), and 0.5 parts activated carbon powder as deodorizer.

[0051] A production process for environmentally friendly high-strength recycled rubber differs from the previous embodiment in that it employs the composite formulation of this embodiment, and the specific process parameters for steps S1-S6 in this embodiment are as follows: In S1, the particle size after coarse crushing is 8 mesh, the washing is ultrasonic cleaning for 15 minutes, the drying temperature is 80℃, the drying time is 15 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0052] In S2, the premixer rotates at 600 r / min, the premixing temperature is 90℃, and the premixing time is 10 min.

[0053] In S3, the preheating stage has a temperature of 150℃, a pressure of 1.2MPa, and a time of 25min; the desulfurization stage has a temperature of 190℃, a pressure of 2.2MPa, and a time of 30min; and the heat preservation stage has a temperature of 170℃, a pressure of 1.8MPa, and a time of 15min.

[0054] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization system are 160℃, 190℃, 210℃, and 170℃, respectively, and the screw speed of the screw extruder is 60 r / min.

[0055] In S5, the primary cooling temperature is 120℃ and the cooling time is 3 minutes, while the secondary cooling temperature is 70℃ and the cooling time is 5 minutes.

[0056] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0057] Example 5: A composite formulation of environmentally friendly, high-strength recycled rubber differs from Example 1 in that the specific amounts of each component in this example are as follows: The product contains 100 parts of truck tire tread rubber powder, 3 parts of a high-efficiency composite activator (specifically 0.4 parts of 2-mercaptobenzothiazole, 0.4 parts of 2-mercaptobenzoimidazolium, 0.8 parts of modified nano magnesium oxide, 1.2 parts of modified nano zinc oxide, and 0.2 parts of triethanolamine), 11 parts of a composite environmentally friendly softener (specifically 7 parts of environmentally friendly aromatic oil, 2 parts of pine tar, and 2 parts of methyl oleate), 2.8 parts of an anti-aging and reinforcing agent (specifically 0.5 parts of phenolic antioxidant, 0.8 parts of stearic acid, and 1.5 parts of modified nano silica), and 0.4 parts of activated carbon powder as a deodorizer.

[0058] A production process for environmentally friendly high-strength recycled rubber differs from the previous embodiment in that it employs the composite formulation of this embodiment, and the specific process parameters for steps S1-S6 in this embodiment are as follows: In S1, the particle size after coarse crushing is 8 mesh, the washing is ultrasonic cleaning for 18 minutes, the drying temperature is 85℃, the drying time is 15 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0059] In S2, the premixer speed is 700 r / min, the premixing temperature is 85℃, and the premixing time is 10 min.

[0060] In S3, the preheating stage has a temperature of 170℃, a pressure of 1.4MPa, and a time of 20min; the desulfurization stage has a temperature of 195℃, a pressure of 2.2MPa, and a time of 30min; and the heat preservation stage has a temperature of 175℃, a pressure of 1.8MPa, and a time of 10min.

[0061] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization system are 165℃, 180-190℃, 205℃, and 175℃, respectively, and the screw speed of the screw extruder is 65 r / min.

[0062] In S5, the primary cooling temperature is 125℃ and the cooling time is 2 minutes, while the secondary cooling temperature is 75℃ and the cooling time is 5 minutes.

[0063] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0064] Example 6: A composite formulation of environmentally friendly, high-strength recycled rubber differs from Example 1 in that the specific amounts of each component in this example are as follows: The product contains 100 parts of truck tire tread rubber powder, 3.65 parts of a high-efficiency composite activator (specifically, 0.4 parts of 2-mercaptobenzothiazole, 0.6 parts of 2-mercaptobenzoimidazolium, 0.8 parts of modified nano magnesium oxide, 1.6 parts of modified nano zinc oxide, and 0.25 parts of triethanolamine), 14 parts of a composite environmentally friendly softener (specifically, 7 parts of environmentally friendly aromatic oil, 3 parts of pine tar, and 4 parts of methyl oleate), 3.1 parts of an anti-aging and reinforcing agent (specifically, 0.7 parts of phenolic antioxidant, 0.8 parts of stearic acid, and 1.6 parts of modified nano silica), and 0.4 parts of activated carbon powder as a deodorizer.

[0065] A production process for environmentally friendly high-strength recycled rubber differs from the previous embodiment in that it employs the composite formulation of this embodiment, and the specific process parameters for steps S1-S6 in this embodiment are as follows: In S1, the particle size after coarse crushing is 8 mesh, the washing is ultrasonic cleaning for 15 minutes, the drying temperature is 80℃, the drying time is 10 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0066] In S2, the premixer rotates at 600 r / min, the premixing temperature is 80℃, and the premixing time is 15 min.

[0067] In S3, the preheating stage has a temperature of 150℃, a pressure of 1.2MPa, and a time of 25min; the desulfurization stage has a temperature of 190℃, a pressure of 2.0MPa, and a time of 35min; and the heat preservation stage has a temperature of 170℃, a pressure of 1.6MPa, and a time of 15min.

[0068] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization are 160℃, 180℃, 200℃, and 170℃ respectively, and the screw speed of the screw extruder is 60r / min.

[0069] In S5, the primary cooling temperature is 120℃ and the cooling time is 3 minutes, while the secondary cooling temperature is 70℃ and the cooling time is 5 minutes.

[0070] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0071] Example 7: A composite formulation of environmentally friendly, high-strength recycled rubber differs from Example 1 in that the specific amounts of each component in this example are as follows: The product contains 100 parts of truck tire tread rubber powder, 2.9 parts of a high-efficiency composite activator (specifically, 0.5 parts of 2-mercaptobenzothiazole, 0.4 parts of 2-mercaptobenzoimidazolium, 0.6 parts of modified nano magnesium oxide, 1.2 parts of modified nano zinc oxide, and 0.2 parts of triethanolamine), 10.5 parts of a composite environmentally friendly softener (specifically, 6 parts of environmentally friendly aromatic oil, 2.5 parts of pine tar, and 2 parts of methyl oleate), 3.3 parts of an anti-aging and reinforcing agent (specifically, 0.5 parts of phenolic antioxidant, 0.9 parts of stearic acid, and 1.9 parts of modified nano silica), and 0.5 parts of activated carbon powder as a deodorizer.

[0072] A production process for environmentally friendly high-strength recycled rubber differs from the previous embodiment in that it employs the composite formulation of this embodiment, and the specific process parameters for steps S1-S6 in this embodiment are as follows: In S1, the particle size after coarse crushing is 8 mesh, ultrasonic cleaning is performed for 20 minutes, drying temperature is 90℃, drying time is 10 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0073] In S2, the premixer rotates at 600 r / min, the premixing temperature is 90℃, and the premixing time is 10 min.

[0074] In S3, the preheating stage has a temperature of 150℃, a pressure of 1.2MPa, and a time of 20min; the desulfurization stage has a temperature of 190℃, a pressure of 2.0MPa, and a time of 30min; and the heat preservation stage has a temperature of 170℃, a pressure of 1.6MPa, and a time of 10min.

[0075] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization system are 160℃, 180℃, 210℃, and 180℃ respectively, and the screw speed of the screw extruder is 60r / min.

[0076] In S5, the primary cooling temperature is 130℃ and the cooling time is 2 minutes, while the secondary cooling temperature is 80℃ and the cooling time is 3 minutes.

[0077] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0078] Example 8: A composite formulation of environmentally friendly, high-strength recycled rubber differs from Example 1 in that the specific amounts of each component in this example are as follows: The product contains 100 parts of truck tire tread rubber powder, 3.4 parts of a high-efficiency composite activator (specifically, 0.3 parts of 2-mercaptobenzothiazole, 0.5 parts of 2-mercaptobenzoimidazolium, 0.9 parts of modified nano magnesium oxide, 1.4 parts of modified nano zinc oxide, and 0.3 parts of triethanolamine), 14.5 parts of a composite environmentally friendly softener (specifically, 8 parts of environmentally friendly aromatic oil, 2.5 parts of pine tar, and 4 parts of methyl oleate), 3.4 parts of an anti-aging and reinforcing agent (specifically, 0.7 parts of phenolic antioxidant, 0.7 parts of stearic acid, and 2.0 parts of modified nano silica), and 0.4 parts of activated carbon powder as a deodorizer.

[0079] A production process for environmentally friendly high-strength recycled rubber differs from the previous embodiment in that it employs the composite formulation of this embodiment, and the specific process parameters for steps S1-S6 in this embodiment are as follows: In S1, the particle size after coarse crushing is 8 mesh, ultrasonic cleaning is performed for 20 minutes, drying temperature is 90℃, drying time is 10 minutes, the particle size after fine crushing is 20-40 mesh, and the impurity removal rate of the three-stage impurity removal is ≥99.5%.

[0080] In S2, the premixer speed is 800 r / min, the premixing temperature is 85℃, and the premixing time is 13 min.

[0081] In S3, the preheating stage has a temperature of 160℃, a pressure of 1.4MPa, and a time of 23min; the desulfurization stage has a temperature of 200℃, a pressure of 2.2MPa, and a time of 32min; and the heat preservation stage has a temperature of 180℃, a pressure of 1.8MPa, and a time of 12min.

[0082] In S4, the operating temperatures of the feeding section, compression section, desulfurization section, and discharge section of the segmented temperature-controlled desulfurization are 170℃, 190℃, 200℃, and 170℃ respectively, and the screw speed of the screw extruder is 70r / min.

[0083] In S5, the primary cooling temperature is 130℃ and the cooling time is 3 minutes, while the secondary cooling temperature is 80℃ and the cooling time is 5 minutes.

[0084] In S6, 30-mesh and 100-mesh meshes are used for multi-stage filtration.

[0085] Comparative Example 1: The desulfurization process used 0.8 parts of 2-mercaptobenzimidazole and 12 parts of aromatic oil as single activators, without any reinforcing agents or deodorizing agents. A 10 cubic meter pre-stirred desulfurization tank was used for single-stage desulfurization, with the temperature controlled at 200℃, the pressure at 2.0 MPa, and the time at 60 min. Precision filtration was performed using two-stage filtration with 30-mesh and 100-mesh screens. The remaining steps and parameters were the same as in Example 1.

[0086] Comparative Example 2: Commercially available high-strength reclaimed rubber products with a strength of 14MPa are produced using standard formulations and processes.

[0087] The mechanical and environmental properties of the reclaimed rubber prepared in Examples 1 to 8 of this invention were compared with those of the reclaimed rubber prepared in Comparative Example 1 and the purchased reclaimed rubber in Comparative Example 2. Specifically, the mechanical properties, environmental properties, tensile strength, elongation at break, Shore hardness, and total polycyclic aromatic hydrocarbons were compared. The comparison results are as follows: Figure 2 As shown.

[0088] according to Figure 2 The comparison results show that the reclaimed rubber prepared using the formula and process of this invention has a tensile strength ≥16MPa, an elongation at break >500%, a Shore hardness between 60 and 70, and a total polycyclic aromatic hydrocarbon content <150ppm / kg. Its mechanical properties and environmental performance are superior to conventional high-strength reclaimed rubber products currently on the market.

[0089] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A composite formulation of environmentally friendly, high-strength recycled rubber, characterized in that: Based on 100 parts by weight of truck tire tread compound, it includes the following components: Truck tire tread rubber powder: 100 parts, particle size 20-40 mesh, metal and fiber impurity removal rate ≥99.5%; Highly efficient composite activator: 2.8-3.9 parts, composed of 0.3-0.5 parts of 2-mercaptobenzothiazole, 0.4-0.6 parts of 2-mercaptobenzoimidazolium, 0.7-0.9 parts of modified nano magnesium oxide, 1.2-1.6 parts of modified nano zinc oxide, and 0.2-0.3 parts of triethanolamine; Composite environmentally friendly softener: 10-15 parts, composed of 6-8 parts of environmentally friendly aromatic oil, 2-3 parts of pine tar, and 2-4 parts of methyl oleate; Anti-aging and reinforcing agent: 2.7-3.6 parts, composed of 0.5-0.7 parts phenolic antioxidant, 0.7-0.9 parts stearic acid, and 1.5-2.0 parts modified nano-silica; Odor remover: 0.3-0.5 parts activated charcoal powder.

2. The composite formulation of environmentally friendly high-strength recycled rubber according to claim 1, characterized in that: The modified nano-magnesium oxide is modified with stearic acid at a mass ratio of 1:0.08, the modified nano-zinc oxide is modified with silane coupling agent at a mass ratio of 1:0.1, and the modified nano-silica is modified with silane coupling agent at a mass ratio of 1:0.

12.

3. A production process for environmentally friendly, high-strength recycled rubber, characterized in that: The composite formulation described in any one of claims 1-2 specifically includes the following steps: S1. Pretreatment of rubber powder: The raw materials of truck tire tread rubber powder are subjected to coarse crushing, washing, drying, fine crushing and three-stage impurity removal in sequence to obtain 20-40 mesh truck tire tread rubber powder. S2. Rubber premixing: The pretreated truck tire tread rubber powder, high-efficiency composite activator, composite environmentally friendly softener, anti-aging reinforcing agent and deodorizer are added to the premixer in proportion and mixed thoroughly. S3. Segmented pre-mixing desulfurization: The pre-mixed rubber compound is added into a 10 cubic meter pre-mixing desulfurization tank, and pre-mixing desulfurization is carried out by segmented heating and pressurization. S4. Screw extrusion desulfurization: The pre-mixed desulfurized rubber compound is fed into the screw extruder for segmented temperature-controlled desulfurization. S5. Segmented cooling: The desulfurized rubber compound undergoes primary cooling and secondary cooling sequentially. S6. Precision filtration: The cooled rubber material is sent into a precision filter for multi-stage filtration to remove residual impurities. S7. Refining and molding: The filtered rubber material is fed into a refining machine for molding, followed by weighing, packaging and stacking.

4. The production process of environmentally friendly high-strength recycled rubber according to claim 3, characterized in that: In step S1, the particle size of the truck tire tread rubber powder raw material after coarse crushing is 8 mesh, the cleaning is performed by ultrasonic cleaning for 15-20 minutes, the drying temperature is 80-90℃, the drying time is 10-15 minutes, and the particle size after fine crushing is 20-40 mesh.

5. The production process of environmentally friendly high-strength recycled rubber according to claim 4, characterized in that: The three-stage impurity removal in step S1 includes magnetic separation, air separation and electrostatic separation performed sequentially, and the removal rate of metal and fiber impurities in the three-stage impurity removal is ≥99.5%.

6. The production process of environmentally friendly high-strength recycled rubber according to claim 3, characterized in that: In step S2, the premixer rotates at 600-800 r / min, the premixing temperature is 80-90℃, and the premixing time is 10-15 min.

7. The production process of environmentally friendly high-strength recycled rubber according to claim 3, characterized in that: In step S3, the segmented heating and pressurization includes a preheating stage, a desulfurization stage, and a heat preservation stage. The temperature of the preheating stage is 150-160℃, the pressure is 1.2-1.4MPa, and the time is 20-25min. The temperature of the desulfurization stage is 190-200℃, the pressure is 2.0-2.2MPa, and the time is 30-35min. The temperature of the heat preservation stage is 170-180℃, the pressure is 1.6-1.8MPa, and the time is 10-15min.

8. The production process of environmentally friendly high-strength recycled rubber according to claim 3, characterized in that: In step S4, the segmented temperature-controlled desulfurization includes a feeding section, a compression section, a desulfurization section, and a discharge section, with operating temperatures of 160-170℃, 180-190℃, 200-210℃, and 170-180℃ respectively, and the screw speed of the screw extruder is 60-70 r / min.

9. The production process of environmentally friendly high-strength recycled rubber according to claim 3, characterized in that: In step S5, the temperature of the first-stage cooling is 120-130℃ and the cooling time is 2-3 minutes, while the temperature of the second-stage cooling is 70-80℃ and the cooling time is 3-5 minutes.

10. The production process of environmentally friendly high-strength recycled rubber according to claim 3, characterized in that: In step S6, the multi-stage filtration consists of 30-mesh filter and 100-mesh filter.

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