Preparation method of supported highly dispersed white carbon black

Abstract

This invention belongs to the field of rubber filler technology, specifically disclosing a method for preparing supported highly dispersed silica, including the following steps: mixing a nanotube carrier with a water glass solution, adding a precipitant to prepolymerize and co-precipitate it to obtain a precursor; preparing a low-alkali water glass solution for the carbon fractionation process and heating it, then adding a nucleating agent and the obtained precursor to it, continuously stirring, and after the temperature stabilizes, introducing carbon dioxide to begin preparing a colloid; after the colloid preparation is completed, stopping the introduction of carbon dioxide and continuing stirring to homogenize its particles; preparing a fused water glass solution for the carbon fractionation process, adding it together with carbon dioxide to the colloidal solution, heating and co-precipitating to obtain supported highly dispersed silica. This invention directly processes the upstream raw material water glass of silica, using finished carbon nanotube emulsions or halloysite nanotubes for preparation, ensuring in-situ growth of silica on the nanotube surface, which not only effectively controls the structure but also greatly improves the product's dispersion performance.

Description

Technical Field

[0001] This invention belongs to the field of rubber filler technology, and relates to the preparation of silica, particularly to a method for preparing supported highly dispersed silica. Background Technology

[0002] Tire's wet grip resistance, low rolling resistance, and high wear resistance are known as the "magic triangle" of tires. High wear resistance provides longer service life, safety, fuel savings, lower noise, and environmental protection, while low rolling resistance reduces heat generation, saves fuel, and increases tire life. When a tire undergoes periodic deformation, the rubber material is subjected to dynamic alternating stress. Under the action of external forces, the rubber molecular chains and filler particles move relative to each other, causing relative sliding between the rubber molecular chains, between the molecular chains and filler particles, and between the filler particles themselves. The part of the tire in contact with the ground undergoes compression, shearing, and stretching processes. Microscopically, rubber wear is due to the continuous compression, shearing, and stretching under periodic stress. Each compression, shearing, and stretching process causes changes in the internal structure of the rubber and generates energy loss. The heat generated by this energy loss, combined with the dynamic stress, accelerates the aging and breakage of rubber molecules. This cycle repeats itself, eventually leading to fatigue failure of rubber materials. Rubber wear resistance is quantitatively related to friction and crack propagation characteristics. Adding rod-shaped rigid materials, such as carbon nanotubes and halloysite nanotubes, can effectively improve the structural strength of rubber and increase the wear resistance of filled rubber. Moreover, like most polymers, rubber is a poor conductor of heat, and therefore cannot quickly transfer internal heat to the outside. This manifests macroscopically as significant internal heat generation and high energy consumption, accelerating rubber aging and reducing the safety and lifespan of rubber products. Therefore, high-component, high-thermal-conductivity carbon nanotubes also provide a new method for controlling the dynamic temperature rise of rubber. In this case, the ideal state of the loaded filler is to partially load silica on the surface of carbon nanotubes. This can both enable the thermal conductivity of carbon nanotubes and prevent carbon nanotube agglomeration, while the agglomeration of silica is solved by the silane system.

[0003] Common filler and rubber processing techniques involve directly adding the materials to the mixing process. However, for silica-rubber systems, the high specific surface area and strong adsorption of carbon nanotubes / haloysite nanotubes lead to severe agglomeration, resulting in uneven mixing and subsequent agglomeration. Pre-mixing silica with carbon nanotubes / haloysite nanotubes using a loading method before mixing can significantly reduce the agglomeration of both fillers, increase dispersion, and improve performance. However, this may increase costs. Such loaded materials require a high-conductivity carbon nanotube / haloysite nanotube matrix, with silica partially loaded onto its surface. This simultaneously achieves the reinforcement of silica and the high conductivity / structural strength of carbon nanotubes or the structural strength of halloysite nanotubes.

[0004] Currently, among the carbon nanotube loading processes: Patent CN115433391A discloses a loading method in which an aqueous dispersion of carbon nanotubes is modified with plant polyphenols, and an aqueous dispersion of finished silica is modified with olefin compounds. The two are then mixed and bonded together via hydrogen bonding to form a loading material. Patent CN115584060A discloses a loading method in which sodium carboxymethyl cellulose is added to an aqueous dispersion of carbon nanotubes and finished silica, and then acid is added to generate carboxymethyl cellulose in situ. This carboxymethyl cellulose acts as a binder to bond the two materials, thus forming a loading material. Patent CN112635734B discloses a loading method in which finished silica is amination-treated with toluene as a solvent to obtain a colloid, and carbon nanotubes are carboxylated with acid. The two are then blended and vacuum-dried to obtain the loading material. However, this method uses a large amount of solvent, leading to… The high-temperature reduction step carries significant energy consumption risks and post-processing risks. Patent CN107603280A discloses a loading method in which finished silica and carbon source aqueous solution are mixed and then carbonized and reduced to obtain the loaded material. Patent CN110342528A discloses a gas-phase in-situ process in which carbon source gas is added and reacted together to prepare the loaded material. Patent CN110372911A discloses a loading method in which silica filter cake is first used to prepare silica loaded with metal catalyst, and after high-temperature reduction, carbon source gas is reacted in-situ into carbon nanotubes by CVD reaction to obtain the loaded material. Patent CN105836749A discloses a loading method in which finished silica and nickel-based catalyst are mixed and reduced at high temperature, and then CVD reaction is carried out in air to obtain the loaded material. In the process of halloysite loading: CN117164961A discloses a loading method in which halloysite is first modified with silane, water glass is precipitated with sulfuric acid in the presence of ethanol solvent to generate silica in situ, and then dried to obtain the loaded material; CN105924677B discloses a loading method in which one of the finished silica / haloysite nanotubes is modified with silane, and then the two are dispersed in a solvent and the loaded material is prepared by electrostatic self-assembly; CN109020472A and a series of related patents, CN117358164A, CN118652 CN114053881B and other publications disclose a loading method in which halloysite nanotubes are first modified with silane and other modifiers, and then blended and polymerized with tetraethyl orthosilicate to prepare a loaded material. CN106279772B discloses a loading method in which halloysite is first modified with ammonia and a catalyst, and then mixed and co-precipitated with methyl / ethyl orthosilicate or sodium silicate silicon source to generate silica in situ, thereby preparing a loaded material. CN118459900B discloses a loading method in which halloysite nanotubes are modified with silane and then blended and polymerized with silane to prepare a loaded material.

[0005] Most of the aforementioned patents on carbon nanotube-supported silica use finished silica. Besides the initial high-temperature granulation process during the initial granulation, a second high-temperature granulation is performed after modification. These processes often employ in-situ carbon nanotube generation, which involves growing carbon nanotubes on the surface of the silica, posing a risk of nanotube aggregation. Patents on halloysite nanotube-supported silica mostly use ammonia and organosilanes for dispersion and modification of halloysite nanotubes, resulting in complex processes and reagent risks. The silicon source often uses a system of methyl / ethyl orthosilicate and solvent, posing solvent risks. Some use finished silica, also presenting energy consumption issues due to secondary granulation. The precipitant used in some cases is sulfuric acid, which precipitates silica and may cause aluminum-hydrogen replacement of some halloysite nanotubes, resulting in nanotube loss. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing supported highly dispersed silica. This invention starts with the processing of water glass, the upper-grade raw material of silica, and uses finished carbon nanotube emulsions or halloysite nanotubes for preparation. This ensures that silica is grown in situ on the surface of carbon nanotubes or halloysite nanotubes, which not only effectively controls the structure but also greatly improves the dispersion performance of the product.

[0007] This invention is achieved through the following technical solution:

[0008] A method for preparing supported highly dispersed silica includes the following steps:

[0009] (1) Prepolymerization: After mixing the carrier with water glass solution in a certain proportion, a precipitant is added to make it prepolymerized and coprecipitated to obtain the precursor;

[0010] (2) Colloid preparation: Prepare the low-alkali water glass solution in the carbon fractionation process and heat it to 40-95℃. Then add the nucleating agent and the precursor obtained in step (1) into it, stir continuously, and after the temperature stabilizes, introduce carbon dioxide to start the preparation of colloid.

[0011] (3) Homogenization: After the colloid is prepared, stop the carbon dioxide flow and keep stirring to homogenize the particles;

[0012] (4) Precipitation: Prepare the condensed water glass solution in the carbon separation process, add it together with carbon dioxide into the colloidal liquid, keep the temperature at 40-95℃, and co-precipitate to obtain highly dispersible carbon nanotube-supported silica.

[0013] The carrier is a carbon nanotube emulsion or halloysite nanotubes.

[0014] A further improvement to the present invention is as follows:

[0015] The concentration of the carbon nanotube emulsion is 0.1-5 wt%.

[0016] Furthermore, the modulus of the water glass raw material is 1.0-3.5, and the concentration of the water glass solution is 1.96-20 SiO2wt%.

[0017] Preferably, the concentration of the water glass solution is 3.84-8.23 wt% SiO2.

[0018] The concentration of the bottom-alkali water glass solution is 2.00-9.00 wt% SiO2;

[0019] The concentration of the condensed water glass solution is 4.70-15.0 wt% SiO2;

[0020] Furthermore, based on the mass of SiO2 and carbon nanotubes, the ratio of the carbon nanotube emulsion to the water glass solution is 1:0.1 to 1, and the ratio of the halloysite nanotubes to the water glass solution is 1:0.1 to 12.

[0021] Preferably, based on the mass of SiO2 and carbon nanotubes, the ratio of the carbon nanotube emulsion to the water glass solution is 1:0.4 to 0.6, and the ratio of the halloysite nanotubes to the water glass solution is 1:2 to 10.

[0022] Furthermore, the precipitant mentioned in step (1) is one or a mixture of two or more of sulfuric acid, hydrochloric acid, nitric acid or carbonic acid.

[0023] Preferably, the precipitant is a combination of carbonic acid and sulfuric acid. The specific process is as follows: first, carbon dioxide is bubbled in until the pH of the prepolymer solution remains constant, and then sulfuric acid is used to adjust the pH of the prepolymer solution to 6.0-7.0, wherein the gas flow rate of carbon dioxide is 200-600 L / h.

[0024] Preferably, the gas flow rate of carbon dioxide is 400-600 L / h.

[0025] Furthermore, the nucleating agent in step (2) is a monovalent metal salt, such as sodium or potassium carbonates, bicarbonates, hydroxides, sulfates, chlorides, nitrates, acetates, etc.; an amino compound, such as ammonia, urea, or tetrapropylammonium hydroxide, etc.; or a surfactant, such as sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide, polyethylene glycol, etc., one or more of the following three categories.

[0026] Preferably, the nucleating agent is one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide, potassium carbonate, potassium bicarbonate, and potassium hydroxide.

[0027] Furthermore, the stirring rate in step (2) is 5-100 Hz; the carbon dioxide flow rate is 200-600 L / h.

[0028] Preferably, in step (2), the temperature is heated to 80-90℃; the carbon dioxide flow rate is 300-500L / h; and the stirring rate is 35-45Hz.

[0029] Furthermore, the temperature in step (4) is 80-90℃; the carbon dioxide flow rate is 200-600L / h; and the stirring rate is 5-100Hz.

[0030] Preferably, the carbon dioxide flow rate is 300-500 L / h; the stirring rate is 35-45 Hz.

[0031] In this invention, the low-alkali water glass solution is a low-concentration water glass solution used for the initial preparation of silica sol; the co-current water glass solution is a high-concentration water glass solution used for the second stage of addition to the sol for further polymerization and precipitation. The co-current flow method is adopted, hence the name co-current.

[0032] A further improvement of the present invention is as follows:

[0033] Application of the prepared supported highly dispersed silica in rubber preparation.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] This invention employs a one-step co-precipitation method, which, compared to using finished silica, reduces one high-temperature granulation process, significantly lowering energy consumption, and offers a greater energy advantage compared to the gas-phase method; it does not use additional modifiers or organic solvents, reducing process difficulty and cost; and it does not introduce additional metal elements, ensuring the purity of the product.

[0036] This invention starts with water glass, a high-grade raw material for silica, and uses finished carbon nanotube emulsions or halloysite nanotubes for preparation. This ensures in-situ growth of silica on the surface of carbon nanotubes or halloysite nanotubes, which not only effectively controls the structure but also greatly improves the product's dispersion performance. The process of this invention avoids demulsification, resulting in a well-loaded product with minimal agglomeration of carbon nanotubes or halloysite nanotubes.

[0037] This invention is highly related to the carbon fractionation process for silica, and its properties, such as specific surface area, particle size, and surface hydroxyl content, can be freely adjusted without being restricted by commercially available silica products.

[0038] In the carbon nanotube or halloysite nanotube-supported silica of the present invention, the carbon nanotube component can be controlled at 0.01-50 wt%, and the halloysite nanotube component can be controlled at 0.01-200 wt%. Attached Figure Description

[0039] Figure 1 The TEM images of carbon nanotube-loaded silica prepared in the comparative examples and embodiments of this invention are shown.

[0040] Figure 2 The images show SEM images of carbon nanotube-supported silica prepared in the comparative examples and embodiments of this invention. Detailed Implementation

[0041] The present invention will now be described in detail with reference to specific embodiments.

[0042] Materials and instruments used in the embodiments of this invention:

[0043] The concentration of carbon nanotube emulsion used was 0-5 wt%, and the dispersant in the emulsion was 10% carbon nanotubes; the purity of halloysite nanotubes used was above 99%; the modulus of water glass was 1.0-3.3; the concentration of SiO2 in the water glass solution was 4.75-8.23%; the concentration of ammonia was 26%; the concentration of sulfuric acid was 50%; carbon dioxide and all nucleating agents were chemically pure; and the prepolymerization effect was tested by TEM, SEM, and BET.

[0044] TEM testing instrument information: FEI Tecnai F20 (USA).

[0045] SEM testing instrument information: Hitachi Regulus 8100 (Japan).

[0046] BET testing instrument information: Beijing Jingwei Gaobo JW-BK222-01.

[0047] Comparative Example 1

[0048] Carbon nanotubes and silica were blended at a ratio of 2:100 and stirred at high speed to obtain a sample.

[0049] Comparative Example 2

[0050] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 2 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0051] Comparative Example 3

[0052] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 427 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.57 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0053] Comparative Example 4

[0054] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 533 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.47 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0055] Comparative Example 5

[0056] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 640 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.36 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0057] Comparative Example 6

[0058] A carbon nanotube emulsion was diluted to a concentration of 6 wt%. 500 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0059] Comparative Example 7

[0060] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 300 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0061] Comparative Example 8

[0062] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. The pH was adjusted to 6.0-7.0 at room temperature using 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was passed through at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was passed through to co-precipitate and prepare the supported material.

[0063] Comparative Example 9

[0064] Halloysite nanotubes and silica were blended at a mass ratio of 14.3:100 and stirred vigorously to obtain a sample.

[0065] Comparative Example 10

[0066] 300g of halloysite nanotubes were added to 22kg of a low-alkali water glass solution with a SiO2 content of 4.75wt%. After adding a certain amount of sodium carbonate, carbon dioxide was passed through at a flow rate of 500L / h to prepare a colloid. After homogenization, 12kg of a fused water glass solution with a SiO2 content of 8.23wt% was added, and carbon dioxide was passed through to co-precipitate and prepare the supported material.

[0067] Comparative Example 11

[0068] 300g of halloysite nanotubes were dispersed in 2000g of water, 200ml of 26% ammonia and 1g of tetrabutylammonium bromide were added, and the mixture was ultrasonically stirred for 30min. The dispersion was then added to 22kg of a low-alkali water glass solution with a SiO2 content of 4.75wt%. After adding a certain amount of sodium carbonate, carbon dioxide was passed through at a flow rate of 500L / h to prepare a colloid. After homogenization, 12kg of a fused water glass solution with a SiO2 content of 8.23wt% was added, and carbon dioxide was passed through to coprecipitate and prepare the supported material.

[0069] Comparative Example 12

[0070] 30g of halloysite nanotubes and 300g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h at room temperature until the pH no longer changed and the viscosity appeared to increase, thus obtaining a prepolymer. The prepolymer was then added to 21.7kg of a low-alkali water glass solution with a SiO2 content of 4.75wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h to prepare a colloid. After homogenization, 12.00kg of a fused water glass solution with a SiO2 content of 8.23wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0071] Comparative Example 13

[0072] 90g of halloysite nanotubes and 300g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h at room temperature until the pH no longer changed and the viscosity appeared to increase, thus obtaining a prepolymer. The prepolymer was added to 21.7kg of a low-alkali water glass solution with a SiO2 content of 4.75wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h to prepare a colloid. After homogenization, 12.00kg of a fused water glass solution with a SiO2 content of 8.23wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0073] Comparative Example 14

[0074] 200g of halloysite nanotubes and 300g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h at room temperature until the pH no longer changed and the viscosity appeared to increase, thus obtaining a prepolymer. The prepolymer was added to 21.7kg of a low-alkali water glass solution with a SiO2 content of 5.75wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h to prepare a colloid. After homogenization, 12.00kg of a fused water glass solution with a SiO2 content of 8.23wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0075] Example 1

[0076] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 107 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.89 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0077] Example 2

[0078] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 213 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.79 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0079] Example 3

[0080] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0081] Example 4

[0082] A carbon nanotube emulsion was diluted to a concentration of 2 wt%. 1500 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0083] Example 5:

[0084] A carbon nanotube emulsion was diluted to a concentration of 5 wt%. 600 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0085] Example 6

[0086] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 400 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was bubbled through the mixture at a flow rate of 400 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0087] Example 7

[0088] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 2 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of ammonia, carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0089] Example 8

[0090] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 2 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium dodecyl sulfonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0091] Example 9

[0092] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 600 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.68 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was bubbled through the mixture at a flow rate of 600 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0093] Example 10

[0094] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 6818 g of the diluted emulsion and 800 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 21.20 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused-liquid water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0095] Example 11

[0096] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 13636 g of the diluted emulsion and 1600 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50% sulfuric acid to obtain a prepolymer. The prepolymer was added to 20.40 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0097] Example 12

[0098] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 27273 g of the diluted emulsion and 3200 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 18.80 kg of a low-alkali water glass solution with a SiO2 content of 4.75 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0099] Example 13

[0100] A carbon nanotube emulsion was diluted to a concentration of 1.1 wt%. 2727 g of the diluted emulsion and 320 g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75 wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h at room temperature until the pH no longer changed. The pH was then adjusted to 6.0-7.0 with 50 wt% sulfuric acid to obtain a prepolymer. The prepolymer was added to 14.68 kg of a low-alkali water glass solution with a SiO2 content of 6.53 wt%. After adding a certain amount of sodium carbonate, carbon dioxide was bubbled through the mixture at a flow rate of 500 L / h to prepare a colloid. After homogenization, 12.00 kg of a fused water glass solution with a SiO2 content of 8.23 ​​wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0101] Example 14

[0102] 300g of halloysite nanotubes and 1500g of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h at room temperature until the pH no longer changed and the viscosity appeared to increase, thus obtaining a prepolymer. The prepolymer was then added to 20.5kg of a low-alkali water glass solution with a SiO2 content of 4.75wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h to prepare a colloid. After homogenization, 12.00kg of a fused water glass solution with a SiO2 content of 8.23wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0103] Example 15

[0104] 3000g of halloysite nanotubes and 15kg of a water glass solution with a modulus of 3.25 and a SiO2 content of 4.75wt% were added to a reaction flask and mixed thoroughly. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h at room temperature until the pH no longer changed and the viscosity appeared to increase, thus obtaining a prepolymer. The prepolymer was then added to 7kg of a low-alkali water glass solution with a SiO2 content of 4.75wt%, and a certain amount of sodium carbonate was added. Carbon dioxide was bubbled through the mixture at a flow rate of 500L / h to prepare a colloid. After homogenization, 12.00kg of a fused water glass solution with a SiO2 content of 8.23wt% was added, and carbon dioxide was bubbled through the mixture to co-precipitate and prepare the supported material.

[0105] The analytical data of the products obtained in the comparative examples and embodiments are shown in the table below.

[0106]

[0107]

[0108] As shown in the table above, this invention does not rely on finished silica, has controllable performance, and has a greater distribution of macropores, which is more conducive to the reinforcement of rubber fillers.

[0109] The morphological characteristics of the silica prepared in some comparative examples and embodiments are shown in the figures. Figure 1 and Figure 2 .Depend on Figure 1 and Figure 2 It can be seen that the product provided by the method of the present invention has good dispersion performance, good loading effect, and mild agglomeration phenomenon.

[0110] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing supported highly dispersed silica, characterized in that, Includes the following steps: (1) Prepolymerization: After mixing the carrier with water glass solution in a certain proportion, a precipitant is added to make it prepolymerized and coprecipitated to obtain the precursor; (2) Colloid preparation: Prepare the low-alkali water glass in the carbon fractionation process and heat it to 40-95℃. Then add the nucleating agent and the precursor obtained in step (1) into it and stir continuously. After the temperature stabilizes, introduce carbon dioxide to start the preparation of colloid. (3) Homogenization: After the colloid is prepared, stop the carbon dioxide flow and keep stirring to homogenize the particles; (4) Precipitation: The co-liquid water glass and carbon dioxide in the carbon separation process are added to the colloidal liquid, and the temperature is maintained at 40-95℃. Co-precipitation is carried out to obtain the supported high-dispersion silica. The carrier is a carbon nanotube emulsion or halloysite nanotubes.

2. The method for preparing supported highly dispersed silica according to claim 1, characterized in that: The concentration of the carbon nanotube emulsion is 0.1-5 wt%.

3. The method for preparing supported highly dispersed silica according to claim 1, characterized in that: The modulus of the water glass raw material is 1.0-3.5, and the concentration of the water glass solution is 1.96-20wt%.

4. The method for preparing supported highly dispersed silica according to claim 1, characterized in that: The ratio of the carbon nanotube emulsion to the water glass solution is 1:0.1~1 based on the mass of SiO2 and carbon nanotubes, and the ratio of the halloysite nanotubes to the water glass solution is 1:0.1~12 based on the mass of SiO2 and halloysite nanotubes.

5. The method for preparing supported highly dispersed silica according to claim 1, characterized in that: The nucleating agent is selected from monovalent metal salts, amino compounds, or surfactants. The monovalent metal salt is a carbonate, bicarbonate, sulfate, chloride, nitrate, or acetate of sodium or potassium. The amino compound is ammonia, urea, or tetrapropylammonium hydroxide. The surfactant is sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide, or polyethylene glycol.

6. The method for preparing supported highly dispersed silica according to claim 1, characterized in that: The precipitant is one or a mixture of two or more of sulfuric acid, hydrochloric acid, nitric acid, or carbonic acid.

7. The method for preparing supported highly dispersed silica according to claim 6, characterized in that: The precipitant is a combination of carbonic acid and sulfuric acid. The specific process is as follows: first, carbon dioxide is bubbled in until the pH of the prepolymer solution remains constant, and then sulfuric acid is used to adjust the pH of the prepolymer solution to 6.0-7.0, wherein the gas flow rate of carbon dioxide is 200-600 L / h.

8. The method for preparing supported highly dispersed silica according to claim 1, characterized in that: In step (2), the carbon dioxide flow rate is 200-600 L / h.

9. The method for preparing supported highly dispersed silica according to claim 1, characterized in that: The temperature in step (4) is 80-90℃; the carbon dioxide flow rate is 200-600L / h.

10. The application of the supported highly dispersed silica prepared by the method according to any one of claims 1 to 9 in the preparation of rubber.

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