Production method of silicon dioxide slurry for wet mixing of rubber
By incorporating high-temperature and sulfate-resistant dispersants, primary treatment agents, and fatty alcohol polyoxyethylene ether phosphates through specific synthesis reactions and pulping steps, the problems of poor filler dispersibility and stability in wet mixing processes are solved, thereby improving the strength and stability of rubber products, extending their service life, and reducing energy consumption.
Patent Information
- Application Number
- CN202511577359.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-02-27
AI Technical Summary
In existing wet mixing processes, the poor dispersibility and stability of fillers result in poor strength and stability of rubber products, limiting their application range and lifespan.
By employing specific synthesis reactions and pulping steps, and adding high-temperature and sulfate-resistant dispersants, primary treatment agents, and fatty alcohol polyoxyethylene ether phosphate, combined with nanoparticles and composite liquids, the dispersibility and stability of the slurry are enhanced, avoiding sedimentation and viscosity changes.
It improves the compatibility between silica slurry and rubber, enhances the strength and stability of rubber products, extends service life, and reduces energy consumption and costs.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of silica technology, specifically relating to a method for producing silica slurry for wet rubber compounding. Background Technology
[0002] Wet-process rubber compounding is a process in which fillers (such as silica, carbon black, etc.) are directly dispersed into rubber latex in the form of a slurry, and then the compound is prepared through processes such as blending, flocculation, and drying.
[0003] Compared to traditional dry mixing, wet mixing significantly improves filler dispersibility, reduces dust pollution, and enhances rubber properties such as wet slip resistance and rolling resistance. The basic process involves selecting suitable fillers such as silica (precipitation or fumed silica) and carbon black, pre-dispersing them with water to form a high-solids slurry (target solids content 20-30%), then adding a dispersant and using high-speed shearing or grinding equipment to fully disperse the filler, reduce viscosity, and adjust the pH to 8-10 to prevent flocculation or sedimentation. A suitable latex is then diluted to the appropriate concentration, and the slurry-state silica and latex are mixed while maintaining stirring. Other additives (such as coupling agent Si-69, antioxidants, accelerators, etc.) are added, and after mixing to the appropriate state, acid or salt is added to promote latex stability degradation, causing the rubber and filler to precipitate together. The moisture and residual electrolytes are then removed by dehydration and washing. After further drying using a screw extrusion dryer, fluidized bed or vacuum drying equipment, the product is granulated and finally mixed and post-treated to ensure the stability and processability (Mooney viscosity, dispersibility, etc.) of the rubber compound.
[0004] Compared to dry mixing, this method results in more uniform filler dispersion and saves on the high energy consumption of dry mixing. However, since the filler still uses dried solid silica, which is then remixed with water to form a slurry, not only is there a significant waste of energy, but the dispersibility and stability of the silica are also greatly reduced. When mixed with rubber, the silica exhibits poor interfacial compatibility and severe agglomeration, which in turn affects the homogeneity of the rubber compound, reduces its strength and stability, shortens its service life, and limits its application range.
[0005] This invention provides a production technology for silica slurry for wet rubber compounding. By treating the washed silica slurry for dispersion and stability, it can not only meet the requirements of wet rubber compounding for fillers, but also maintain stability during transportation and storage, without flocculation or sedimentation. The resulting rubber compound has excellent strength and stability. Summary of the Invention
[0006] To address the technical problems existing in the prior art, this invention provides a method for producing silica slurry for rubber compounding. The silica slurry exhibits good quality stability and low sedimentation rate. When used in rubber compounding, it demonstrates good compatibility with rubber, effectively improving the strength of rubber products, ensuring performance in complex environments, and extending product lifespan.
[0007] To address the technical problems, the present invention adopts the following technical solution: A method for producing silica slurry for wet rubber compounding includes a synthesis reaction and a slurry preparation step, the specific operation of which is as follows: 1. Synthesis reaction Liquid sodium silicate was first added to the synthesis reactor, and the stirring speed was controlled at 60-90 rpm. While stirring, the temperature was raised to 82-90℃, and deionized water was added to obtain the base material. The concentration of the base material was controlled at 0.095-0.105 mol / L, with a concentration of 0.5-0.6 mg / L. 3 Sulfuric acid solution was added at a rate of / h, followed by a second addition of liquid sodium silicate at a rate of 7.15-8.0m. 3 The addition rate is 7.8-8.0 m. 3 The addition rate is 55-60 minutes per hour. After the liquid sodium silicate is added, the addition rate of sulfuric acid solution is reduced to 0.3-0.4 minutes per hour. 3 / h, when the pH of the feed solution in the synthesis reactor is 4.5-5.0, stop adding sulfuric acid solution, keep warm and mature for 30-60 min, add 180-200 kg of ammonium polyacrylate, stir at 60-90 rpm for 10-15 min and discharge, wash and filter, control the filtration pressure at 0.3-0.8 MPa to obtain silica filter cake; The volume-to-mass ratio of the first addition of liquid sodium silicate, the subsequent addition of liquid sodium silicate, and the addition of ammonium polyacrylate is 5.0 m³. 3 7.15-8.0m 3 180-200kg; The liquid sodium silicate has a modulus of 2.8-3.6 and a concentration of 0.75-1.5 mol / L; The sulfuric acid solution has a mass concentration of 93-98%; 2. Pulping The silica filter cake is slurried and added to a suspension. The addition rate of the suspension is controlled at 5-6 kg / min. After the addition is complete, nanoparticles and composite liquid are added. The mixture is stirred at 32-36℃ for 1.0-1.3 h. Deionized water is added to obtain a silica slurry with a solid content of 25-35%. The mass ratio of the suspension to ammonium polyacrylate is 280-300:200; The mass ratio of the suspension, nanopowder, and composite liquid is 280-300:30-40:100-110; The suspension is prepared by adding toluene to a reaction apparatus, raising the temperature to 60-63°C under a nitrogen atmosphere, adding hydrogenated castor oil, stirring at 220-230 rpm for 30-40 min, adding antioxidant 1010, stirring for 10-14 min, adding maleic anhydride, stirring for 20-26 min, then raising the temperature to 82-85°C at a rate of 1.2-1.6°C / min, adding benzoyl peroxide, maintaining the temperature and stirring for 3.0-3.5 h, removing toluene and drying to obtain a primary treatment agent; adding the primary treatment agent to deionized water, stirring evenly, adding fatty alcohol polyoxyethylene ether phosphate, stirring and dispersing at 1200-1500 rpm for 15-20 min to obtain a suspension; In the method for preparing the suspension, the mass ratio of toluene, hydrogenated castor oil, antioxidant 1010, maleic anhydride, and benzoyl peroxide is 100:16-20:0.2-0.3:2.2-2.5:0.1-0.2. The mass ratio of the primary treatment agent, deionized water and fatty alcohol polyoxyethylene ether phosphate is 80-85:200:17-20. The method for preparing the nanopowder is as follows: aluminum nitride powder and zirconium oxide powder are added to an ethanol solution, stirred evenly, the temperature is raised to 58-64℃, kH560 silane coupling agent is added, and the mixture is stirred at 200-230 rpm for 2.0-2.5 h. After filtration and washing, the nanopowder is dried at 110-115℃ for 8-10 h to obtain the nanopowder. In the preparation method of the nanopowder, the mass ratio of the ethanol solution, aluminum nitride powder, zirconium oxide powder, and kH560 silane coupling agent is 80:4.5-4.7:5.3-5.5:1.0-1.2. The aluminum nitride powder has a particle size of 60-90 nm. The zirconium oxide powder has a particle size of 30-50 nm. The mass concentration of the ethanol solution is 62-65; The method for preparing the composite solution is as follows: raise the temperature of deionized water to 52-58℃, add sodium hexametaphosphate while stirring at 100-120 rpm, continue stirring for 15-20 min, lower the temperature to 34-38℃, add sodium carboxymethyl cellulose, and stir at 220-250 rpm for 25-35 min to obtain the composite solution. In the preparation method of the composite liquid, the mass ratio of deionized water, sodium hexametaphosphate, and sodium carboxymethyl cellulose is 20:2-5:1-5.
[0008] 1. This invention employs a specific synthesis process in the chemical synthesis reaction stage. A high-temperature resistant and sulfate-resistant dispersant is added in the final stage of the synthesis reaction. Furthermore, a primary treatment agent and fatty alcohol polyoxyethylene ether phosphate are added in the pulping step. The primary treatment agent is prepared from hydrogenated castor oil and maleic anhydride, acting as an interfacial bridge. Its polar anhydride / carboxyl groups can be anchored on the silica surface, while its non-polar long chains entangle with the rubber matrix, exhibiting good compatibility. This enhances the dispersibility and stability of the pulp in the organic matrix. Combined with fatty alcohol polyoxyethylene ether phosphate, it ensures… To ensure the stability of the slurry and prevent sedimentation during storage and transportation, nanoparticles and composite liquids are added to the slurry preparation process. These can enhance the strength and stability of the rubber through the nano-reinforcing effect. The combination of sodium hexametaphosphate and sodium carboxymethyl cellulose in the composite liquid, along with the suspension, further improves the dispersion stability of the slurry, avoiding the problem of instability of the filler system during end use, reducing the high requirements of the storage process, eliminating the energy consumption of adding water to the dried product again for slurry preparation, reducing process energy consumption and cost, and improving the quality and stability of rubber products. 2. The silica slurry prepared by the method of the present invention has a sedimentation rate of 0.95-1.06% after being placed at 32°C and 65% relative humidity for 168 hours, and a viscosity change rate of 1.48-1.77% after being placed at 45°C and 65% relative humidity for 21 days. 2. Rubber products made from the silica slurry prepared by the method of this invention have a tensile strength of 33.1-35.4 MPa, a 300% elongation stress of 10.9-12.5 MPa, an elongation at break of 613-621%, and an Akron abrasion of 0.057-0.064 cm. 3 / 1.61km; 3. Rubber products made from the silica slurry prepared by the method of this invention are first immersed in a 15wt% sodium chloride solution for 24 hours, then removed, washed, and dried. The temperature is then increased to 88°C at a rate of 10°C / min, and held at that temperature for 24 hours. This process constitutes one treatment cycle. After 10 consecutive treatment cycles, the tensile strength is measured again to be 31.1-33.7 MPa, the 300% elongation stress is 10.2-11.8 MPa, the elongation at break is 581-597%, and the Akron abrasion is 0.063-0.074 cm. 3 / 1.61km. Detailed Implementation
[0009] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.
[0010] Example 1 1. Synthesis reaction Add 5.0 m to the synthesis reactor. 3 Liquid sodium silicate was stirred at 90 rpm, and the temperature was raised to 90°C while stirring. Deionized water was then added to obtain the base material, with a concentration of 0.105 mol / L. The mixture was then prepared at a concentration of 0.5 mg / L. 3 Sulfuric acid solution is added at a rate of / h, at 8.0m 3 Liquid sodium silicate was added at a rate of 0.5 m / h, and the addition was stopped after 60 min. Then the addition rate of sulfuric acid solution was reduced to 0.3 m / h. 3 / h, when the pH of the feed solution in the synthesis reactor is 5.0, stop adding sulfuric acid solution, keep warm and mature for 60min, add 200kg of ammonium polyacrylate, stir at 90rpm for 15min and discharge, wash and filter, control the filtration pressure to 0.8MPa to obtain silica filter cake. The liquid sodium silicate has a modulus of 3.6 and a concentration of 1.5 mol / L. The sulfuric acid solution has a mass concentration of 98%.
[0011] 2. Pulping The silica filter cake was slurried and 300 kg of suspension was added. The addition rate of the suspension was controlled at 6 kg / min. After the addition was completed, 40 kg of nano powder and -110 kg of composite liquid were added. The mixture was stirred at 36°C for 1.3 h. Deionized water was added to obtain a silica slurry with a solid content of 35%. The mass ratio of the suspension to ammonium polyacrylate is 300:200; The suspension is prepared by adding 100 kg of toluene to a reaction apparatus, raising the temperature to 63°C under a nitrogen atmosphere, adding 20 kg of hydrogenated castor oil, stirring at 230 rpm for 40 min, adding 0.3 kg of antioxidant 1010, stirring for 14 min, adding 2.5 kg of maleic anhydride, stirring for 26 min, then raising the temperature to 85°C at a rate of 1.6°C / min, adding 0.1 kg of benzoyl peroxide, maintaining the temperature and stirring for 3.5 h, removing toluene, and drying to obtain the primary treatment agent; adding 85 kg of the primary treatment agent to 200 kg of deionized water, stirring evenly, adding 20 kg of fatty alcohol polyoxyethylene ether phosphate, stirring and dispersing at 1500 rpm for 20 min to obtain the suspension; The method for preparing the nanopowder is as follows: 4.7 kg of aluminum nitride powder and 5.3 kg of zirconium oxide powder are added to 80 kg of 65 wt% ethanol solution, stirred evenly, the temperature is raised to 64 °C, 1.2 kg of kH560 silane coupling agent is added, and the mixture is stirred at 230 rpm for 2.5 h. After filtration and washing, the nanopowder is dried at 115 °C for 10 h to obtain the nanopowder. The aluminum nitride powder has a particle size of 90 nm. The zirconium oxide powder has a particle size of 50 nm. The method for preparing the composite solution is as follows: 20 kg of deionized water is heated to 58°C, 5 kg of sodium hexametaphosphate is added while stirring at 120 rpm, stirring is continued for 20 min, the temperature is lowered to 38°C, 5 kg of sodium carboxymethyl cellulose is added, and stirring is carried out at 250 rpm for 35 min to obtain the composite solution.
[0012] Example 2 1. Synthesis reaction Add 5.0 m to the synthesis reactor. 3 Liquid sodium silicate was stirred at 80 rpm, and the temperature was raised to 85°C while stirring. Deionized water was then added to obtain the base material, with a concentration of 0.100 mol / L. The mixture was then prepared at a concentration of 0.5 mg / L. 3 Sulfuric acid solution was added at a rate of 7.8 m / h. 3 Liquid sodium silicate was added at a rate of 0.5 m / h, and the addition was stopped after 58 min. Then the addition rate of sulfuric acid solution was reduced to 0.3 m / h. 3 / h, when the pH of the feed solution in the synthesis reactor is 4.8, stop adding sulfuric acid solution, keep warm and mature for 40 min, add 190 kg of ammonium polyacrylate, stir at 75 rpm for 13 min and discharge, wash and filter, control the filtration pressure to 0.5 MPa to obtain silica filter cake. The liquid sodium silicate has a modulus of 3.0 and a concentration of 1.0 mol / L; The sulfuric acid solution has a mass concentration of 95%.
[0013] 2. Pulping The silica filter cake was slurried and 290 kg of suspension was added. The addition rate of the suspension was controlled at 5.5 kg / min. After the addition was completed, 35 kg of nano powder and 105 kg of composite liquid were added. The mixture was stirred at 34°C for 1.2 h. Deionized water was added to obtain a silica slurry with a solid content of 30%. The mass ratio of the suspension to ammonium polyacrylate is 290:200; The suspension is prepared as follows: 100 kg of toluene is added to the reaction apparatus, and the temperature is raised to 62°C under a nitrogen atmosphere. 18 kg of hydrogenated castor oil is added, and the mixture is stirred at 230 rpm for 35 min. 0.3 kg of antioxidant 1010 is added, and the mixture is stirred for 12 min. Then, 2.3 kg of maleic anhydride is added, and the mixture is stirred for 23 min. The temperature is then raised to 83°C at a rate of 1.4°C / min, and 0.1 kg of benzoyl peroxide is added. The mixture is kept warm and stirred for 3.3 h. After removing the toluene, the mixture is dried to obtain the primary treatment agent. 82 kg of the primary treatment agent is added to 200 kg of deionized water, stirred evenly, and then 18 kg of fatty alcohol polyoxyethylene ether phosphate is added. The mixture is stirred and dispersed at 1300 rpm for 18 min to obtain the suspension. The method for preparing the nanopowder is as follows: 4.6 kg of aluminum nitride powder and 5.4 kg of zirconium oxide powder are added to 80 kg of 63 wt% ethanol solution, stirred evenly, the temperature is raised to 60 °C, 1.1 kg of kH560 silane coupling agent is added, stirred at 210 rpm for 2.3 h, filtered, washed, and dried at 112 °C for 9 h to obtain the nanopowder. The aluminum nitride powder has a particle size of 70 nm. The zirconium oxide powder has a particle size of 40 nm. The method for preparing the composite solution is as follows: 20 kg of deionized water is heated to 55°C, 4 kg of sodium hexametaphosphate is added while stirring at 110 rpm, stirring is continued for 17 min, the temperature is lowered to 35°C, 3 kg of sodium carboxymethyl cellulose is added, and stirring is carried out at 230 rpm for 30 min to obtain the composite solution.
[0014] Example 3 1. Synthesis reaction Add 5.0 m to the synthesis reactor. 3 Liquid sodium silicate was stirred at 60 rpm, and the temperature was raised to 82°C while stirring. Deionized water was then added to obtain the base material, with a concentration of 0.095 mol / L. The solution was then prepared at a concentration of 0.6 m... 3 Sulfuric acid solution was added at a rate of 7.8 m / h. 3 Liquid sodium silicate was added at a rate of 0.8 h / h, and the addition was stopped after 55 min. Then the addition rate of sulfuric acid solution was reduced to 0.4 m / h. 3 / h, when the pH of the feed solution in the synthesis reactor is 4.5, stop adding sulfuric acid solution, keep warm and mature for 30 min, add 180 kg of ammonium polyacrylate, stir at 60 rpm for 10 min and discharge, wash and filter, control the filtration pressure to 0.3 MPa to obtain silica filter cake. The liquid sodium silicate has a modulus of 2.8 and a concentration of 0.75 mol / L; The sulfuric acid solution has a mass concentration of 93%.
[0015] 2. Pulping The silica filter cake was slurried and 280 kg of suspension was added. The addition rate of the suspension was controlled at 5 kg / min. After the addition was completed, 30 kg of nano powder and 100 kg of composite liquid were added. The mixture was stirred at 32°C for 1.0 h. Deionized water was added to obtain a silica slurry with a solid content of 25%. The mass ratio of the suspension to ammonium polyacrylate is 280:200; The suspension is prepared as follows: 100 kg of toluene is added to the reaction apparatus, and the temperature is raised to 60°C under a nitrogen atmosphere. 16 kg of hydrogenated castor oil is added, and the mixture is stirred at 220 rpm for 30 min. 0.2 kg of antioxidant 1010 is added, and the mixture is stirred for 10 min. Then, 2.2 kg of maleic anhydride is added, and the mixture is stirred for 20 min. The temperature is then raised to 82°C at a rate of 1.2°C / min, and 0.2 kg of benzoyl peroxide is added. The mixture is kept warm and stirred for 3.0 h. After removing the toluene, the mixture is dried to obtain the primary treatment agent. 80 kg of the primary treatment agent is added to 200 kg of deionized water, stirred evenly, and then 17 kg of fatty alcohol polyoxyethylene ether phosphate is added. The mixture is stirred and dispersed at 1200 rpm for 15 min to obtain the suspension. The method for preparing the nanopowder is as follows: 4.5 kg of aluminum nitride powder and 5.5 kg of zirconium oxide powder are added to 80 kg of 62 wt% ethanol solution, stirred evenly, the temperature is raised to 58 °C, 1.0 kg of kH560 silane coupling agent is added, and the mixture is stirred at 200 rpm for 2.0 h. After filtration and washing, the nanopowder is dried at 110 °C for 8 h to obtain the nanopowder. The aluminum nitride powder has a particle size of 60 nm. The zirconium oxide powder has a particle size of 30 nm. The method for preparing the composite solution is as follows: 20 kg of deionized water is heated to 52°C, 2 kg of sodium hexametaphosphate is added while stirring at 100 rpm, stirring is continued for 15 min, the temperature is lowered to 34°C, 1 kg of sodium carboxymethyl cellulose is added, and stirring is carried out at 220 rpm for 25 min to obtain the composite solution.
[0016] Comparative Example 2-1 Based on Example 2, the following changes were made: 1. In the synthesis reaction steps, the operation step of "adding 190 kg of ammonium polyacrylate and stirring at 75 rpm for 13 min" is omitted; 2. In the pulping step, the suspension is prepared by adding 100 kg of fatty alcohol polyoxyethylene ether phosphate to 200 kg of deionized water and stirring and dispersing at 1300 rpm for 18 min to obtain the suspension. The remaining operations are exactly the same as in Example 2.
[0017] Comparative Example 2-2 Based on Example 2, the following changes were made: In the pulping step, the nanoparticles are prepared by mixing 4.6 kg of aluminum nitride powder and 5.4 kg of zirconium oxide powder evenly to obtain nanoparticles. The aluminum nitride powder has a particle size of 70 nm. The zirconium oxide powder has a particle size of 40 nm. In the pulping process, the step of adding the compound solution is omitted; The remaining operations are exactly the same as in Example 2.
[0018] Performance testing 1. Silica slurry The silica slurries prepared in Examples 1-3, Comparative Examples 2-1, and Comparative Examples 2-2 were subjected to product quality tests, including sedimentation rate and viscosity change rate. The sedimentation rate was measured after the silica slurry was placed at 32°C and 65% relative humidity for 168 hours; the viscosity change rate was measured after the silica slurry was placed at 45°C and 65% relative humidity for 21 days. The specific test results are as follows:
[0019] 2. Rubber products The silica slurries obtained in Examples 1-3, Comparative Examples 2-1, and Comparative Examples 2-2 were used to prepare rubber product test samples. The preparation method for the rubber product test samples was as follows: 10 kg of silica slurry was added to 17 kg of natural rubber latex at a rate of 0.4-0.5 kg / min, and the mixture was stirred at 300 rpm for 30 min. Then, 3.0 kg of silane coupling agent solution was added, and stirring continued for 15 min. Finally, 0.2 kg of antioxidant RD and 0.1 kg of accelerator DM were added. Stirring at a constant speed for 40 minutes, adding sulfuric acid solution to adjust the pH to 4.2, stirring at 200 rpm for 15 minutes, letting stand for 30 minutes, and then dehydrating, washing, and drying to obtain raw rubber material; adding 13 kg of raw rubber material to a two-roll mill, milling at 50°C for 6 minutes, adding 0.5 kg of zinc oxide, 0.3 kg of sulfur, and 0.05 kg of accelerator CZ, and milling for 6 minutes to obtain rubber material to be vulcanized; placing the rubber material to be vulcanized in a flat vulcanizing machine, vulcanizing at 145°C for 20 minutes to obtain rubber product samples for testing; The natural rubber latex has a solid content of 60% and a particle size of 230 nm. The silane coupling solution is prepared by adding 0.4 kg of Si-69 silane coupling agent to 1.1 kg of 55 wt% ethanol solution and stirring for 30 min to obtain the silane coupling solution.
[0020] (1) Basic performance The rubber products prepared in Examples 1-3, Comparative Example 2-1, and Comparative Example 2-2 were subjected to basic performance tests. The test results are as follows:
[0021] (2) Stability The rubber products prepared in Examples 1-3, Comparative Examples 2-1, and Comparative Examples 2-2 were first immersed in a 15wt% sodium chloride solution for 24 hours. After being removed, washed and dried, the temperature was increased to 88°C at a rate of 10°C / min, and the samples were kept at this temperature for 24 hours. This process was repeated as one treatment cycle. After 10 consecutive treatment cycles, the strength properties were tested again. The test results are as follows:
[0022] The experimental results above show that Comparative Example 2-1 omitted ammonium polyacrylate in the synthesis reaction step and replaced the primary treatment agent with fatty alcohol polyoxyethylene ether phosphate in the slurry preparation step. The resulting silica slurry was prone to sedimentation and had a high viscosity change rate after standing. The product obtained by wet mixing had poor dispersibility and compatibility between the silica slurry and latex, weak interfacial bonding, poor homogeneity, low strength, and poor stability of the resulting rubber product. Comparative Example 2-2 did not treat aluminum nitride and zirconium oxide with silane and did not add composite liquid components. The resulting slurry had weak suspension stability, which reduced the overall performance of the final rubber product.
[0023] Unless otherwise specified, all proportions mentioned in this invention are mass proportions, and all percentages are mass percentages.
[0024] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for producing a silica slurry for rubber wet mixing, characterized by, The production method comprises a synthesis reaction step and a pulping step; The synthesis reaction step comprises: adding liquid sodium silicate into a synthesis reactor for the first time, raising the temperature to 82-90℃, adding deionized water to obtain a base material, controlling the concentration of the base material to be 0.095-0.105 mol / L, adding a sulfuric acid solution, and adding liquid sodium silicate for the second time; after the addition of the liquid sodium silicate is completed, the addition rate of the sulfuric acid solution is reduced, and when the pH value of the material liquid in the synthesis reactor is 4.5-5.0, the addition of the sulfuric acid solution is stopped; after heat preservation and aging, polyammonium acrylate is added, and the mixture is stirred and discharged; after washing and filtration, a silicon dioxide filter cake is obtained; The pulping step comprises: pulping the silicon dioxide filter cake, adding a suspension, controlling the addition rate of the suspension to be 5-6 kg / min, and after the addition is completed, adding nano powder and a composite liquid, stirring at 32-36℃ for 1.0-1.3 h, and adding deionized water to obtain a silicon dioxide slurry with a solid content of 25-35%; The preparation method of the suspension comprises: adding toluene into a reaction device, raising the temperature to 60-63℃ under a nitrogen atmosphere, adding hydrogenated castor oil and antioxidant 1010, stirring uniformly, then adding maleic anhydride, stirring for 20-26 min, raising the temperature to 82-85℃, adding benzoyl peroxide, and after heat preservation and stirring for 3.0-3.5 h, drying after removing the toluene to obtain a first treatment agent; and adding the first treatment agent into deionized water, adding fatty alcohol polyoxyethylene ether phosphate, and stirring uniformly to obtain the suspension.
2. The production method of the silicon dioxide slurry for rubber wet mixing according to claim 1, characterized in that, The synthetic reaction step is that liquid sodium silicate is first added into a synthetic reaction kettle, stirring speed is controlled at 60-90 rpm, temperature is raised to 82-90℃ under stirring, deionized water is added to obtain a base material, the concentration of the base material is controlled at 0.095-0.105 mol / L, sulfuric acid solution is added at a rate of 0.5-0.6 m 3 / h, liquid sodium silicate is secondly added, the addition amount is 7.15-8.0 m 3 / h, the addition rate is 7.8-8.0 m 3 / h, and the addition time is 55-60 min; after the addition of liquid sodium silicate is completed, the addition rate of the sulfuric acid solution is reduced to 0.3-0.4 m 3 / h, when the pH value of the material liquid in the synthetic reaction kettle is 4.5-5.0, the addition of the sulfuric acid solution is stopped, heat preservation is carried out for 30-60 min, 180-200 kg of polyacrylammonium is added, stirring is carried out at 60-90 rpm for 10-15 min to discharge, after washing, filtration is carried out, the filtration pressure is controlled at 0.3-0.8 MPa, and a silicon dioxide filter cake is obtained.
3. The production method of the silicon dioxide slurry for rubber wet mixing according to claim 2, characterized in that, The volume mass ratio of the first amount of liquid sodium silicate, the second amount of liquid sodium silicate and the ammonium polyacrylate is 5.0 m 3 :7.15-8.0 m 3 :180-200 kg; The liquid sodium silicate has a modulus of 2.8-3.6 and a concentration of 0.75-1.5 mol / L; The mass concentration of the sulfuric acid solution is 93-98%.
4. The production method of the silicon dioxide slurry for rubber wet mixing according to claim 1, characterized in that, In the pulping step, the mass ratio of the suspension to polyammonium acrylate is 280-300:200; The mass ratio of the suspension, the nano powder and the composite liquid is 280-300:30-40:100-110.
5. The production method of the silicon dioxide slurry for rubber wet mixing according to claim 1, characterized in that, In the preparation method of the suspension, the mass ratio of the toluene, the hydrogenated castor oil, the antioxidant 1010, the maleic anhydride, the benzoyl peroxide is 100:16-20:0.2-0.3:2.2-2.5:0.1-0.2; The mass ratio of the first treatment agent, the deionized water and the fatty alcohol polyoxyethylene ether phosphate is 80-85:200:17-20.
6. The production method of the silicon dioxide slurry for rubber wet mixing according to claim 1, characterized in that, The preparation method of the nano-powder is that aluminum nitride powder and zirconium oxide powder are added into ethanol solution, stirred uniformly, then the temperature is raised to 58-64 DEG C, kH560 silane coupling agent is added, stirred at 200-230 rpm for 2.0-2.5 h, filtered and washed, dried at 110-115 DEG C for 8-10 h to obtain the nano-powder. 7.The method according to claim 6, characterized in that, The mass ratio of the ethanol solution, aluminum nitride powder, zirconium oxide powder and kH560 silane coupling agent is 80:4.5-4.7:5.3-5.5:1.0-1.2; The particle size of the aluminum nitride powder is 60-90 nm; The particle size of the zirconium oxide powder is 30-50 nm; The mass concentration of the ethanol solution is 62-65. 8.The method according to claim 1, characterized in that, The preparation method of the composite liquid is that deionized water is raised to 52-58 DEG C, sodium hexametaphosphate is added under the condition of 100-120 rpm stirring, stirring is continued for 15-20 min, the temperature is lowered to 34-38 DEG C, sodium carboxymethyl cellulose is added, and stirring is carried out at 220-250 rpm for 25-35 min to obtain the composite liquid. 9.The method according to claim 8, characterized in that, The mass ratio of the deionized water, sodium hexametaphosphate and sodium carboxymethyl cellulose is 20:2-5:1-5.