Modified white carbon black as well as preparation method and application thereof
By uniformly infiltrating high molecular weight polymers on the surface and inside of silica, the problems of complexity and poor effect of existing modification methods are solved, efficient modification of silica is achieved, its dispersibility, compatibility and stability are improved, and its application areas are expanded.
Patent Information
- Application Number
- CN202511185877.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-22
- Publication Date
- 2025-10-17
AI Technical Summary
The existing silica modification methods are complex to operate and difficult to control process conditions, resulting in low grafting rate, poor modification effect, and difficulty in improving properties such as dispersibility and compatibility.
Modified silica is prepared by mixing a modifier with silica wet gel and using EB curing or other methods to make the high molecular polymer evenly adhere to the surface of silica and penetrate into the interior thereof, thereby improving its dispersibility, compatibility and stability.
The efficient modification of silica is achieved, which significantly improves its dispersibility, compatibility, stability and water resistance, expands its application field, and the process is simple and easy to control, making it suitable for large-scale industrial applications.
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Figure CN120793949A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of powder preparation, and particularly relates to modified white carbon black, a preparation method and application thereof. BACKGROUND
[0002] White carbon black (precipitated silica) as a high-performance inorganic non-metallic material has seen a sustained increase in market demand in recent years and is widely used in the fields of coatings and inks, rubber, electronic products, etc. Due to the fact that the surface of white carbon black is rich in hydrophilic silicon hydroxyl groups (≡Si-OH), white carbon black is prone to agglomeration, and has poor compatibility with resin matrix and insufficient interfacial bonding capacity, so it is usually necessary to modify white carbon black before use.
[0003] Existing modification methods usually include: first grafting silane coupling agents on the surface of white carbon black to introduce reactive functional groups, and then growing polymer branches (such as polyacrylate) through polymer reaction. However, this modification method is complex to operate and difficult to control the process conditions, and due to the fact that white carbon black is prone to agglomeration, it is prone to result in low grafting rate and poor modification effect, and it is difficult to effectively improve the dispersibility, compatibility and other properties of white carbon black. SUMMARY
[0004] To solve the above problems, the purpose of the embodiments of the present application includes providing modified white carbon black, a preparation method and application thereof, the preparation method effectively improves the dispersibility, compatibility, stability, water resistance, solvent resistance and other properties of white carbon black, and the comprehensive performance is significantly improved, thereby improving the application effect of white carbon black and expanding the application field. In a first aspect, the embodiments of the present application provide a preparation method of modified white carbon black, comprising the following steps: Mixing silica wet gel prepared by a precipitation method or a sol-gel method with a modifier to obtain a mixture; wherein the modifier comprises a solidified monomer and / or an oligomer; Drying and crushing the mixture in sequence to obtain white carbon black containing the solidified monomer and / or the oligomer; Solidifying the solidified monomer and / or the oligomer in the white carbon black to obtain modified white carbon black.
[0005] In the above technical solution, by directly mixing the modifier with the silica wet gel, the modifier can be uniformly dispersed in the silica wet gel, and the high molecular polymer formed by solidification is uniformly attached to the surface of the white carbon black, and due to the porous structure of the white carbon black, the high molecular polymer will also uniformly penetrate into the interior of the white carbon black, thereby realizing efficient modification of the white carbon black, effectively improving the compatibility, dispersibility, stability, water resistance, solvent resistance and other properties of the white carbon black, and significantly improving the comprehensive performance, thereby improving the application effect of the white carbon black and expanding the application field.
[0006] And, the preparation method is simple in operation, easy to control in process condition, and high in curing efficiency and speed, and does not need a complicated post-treatment step, which is beneficial to large-scale industrial application.
[0007] In some embodiments, the curing manner comprises at least one of UV curing, EB curing, microwave curing, laser curing, thermal curing or standing curing. In the technical solution, by controlling the composition of the modifier and the type of the curing monomer, the preparation method can be effectively applied to various curing manners.
[0008] Preferably, the curing manner comprises EB curing.
[0009] In the technical solution, EB curing directly irradiates the curing monomer or oligomer in the material by high-energy electron beams, without the need of curing aids such as initiators and curing agents, and has strong penetrating ability, wide application range, high curing efficiency and speed, uniform curing, and excellent environmental protection, and the cured white carbon black powder has better compatibility, dispersibility, stability, water resistance and solvent resistance.
[0010] Preferably, the modifier further comprises a curing aid. Further, the curing aid comprises at least one of an initiator, a catalyst or a curing agent. When a curing manner other than EB curing is used, the curing aid is added to initiate the curing reaction. In some embodiments, the curing monomer is an unsaturated monomer.
[0011] In the technical solution, the unsaturated monomer usually contains a carbon-carbon double bond, has fast curing speed and high curing efficiency, and has mild curing conditions and wide adaptability, and can meet various performance requirements by selecting different types; and the unsaturated monomer forms a three-dimensional cross-linked network after curing, and has better stability and mechanical strength. Preferably, the curing monomer is an unsaturated monomer capable of EB curing.
[0012] Preferably, the unsaturated monomer comprises at least one of a monofunctional unsaturated monomer, a bifunctional unsaturated monomer or a multifunctional unsaturated monomer. By controlling the number of functional groups in the unsaturated monomer, the curing efficiency can be further improved, and the performance of the powder after curing can be improved.
[0013] Preferably, the unsaturated monomer comprises at least one of an acrylic acid and a derivative thereof, an acrylamide and a derivative thereof, a vinyl, a maleic acid derivative, an allyl or a fluorine-containing olefin.
[0014] Preferably, the oligomer comprises at least one of an acrylate, a vinyl, a vinyl ether, a siloxane acrylate, an epoxy resin, a polyurethane, a phenolic resin or an organic silicon.
[0015] In some embodiments, the modifier further comprises at least one of a coupling agent, a leveling agent, a defoaming agent, a dispersing agent, a colorant, or an organic wax. In the above technical solution, by adding a coupling agent, it is beneficial to further improve the dispersibility of the modified white carbon black, reduce agglomeration, enhance the interfacial bonding force of the powder and the resin matrix, and improve the water resistance and solvent resistance of the material, etc. By adding a leveling agent, it is beneficial to reduce the surface tension of the curing monomer and / or oligomer, promote uniform spreading and wetting in the powder, and make the curing more uniform. By adding a defoaming agent, the bubbles generated in the curing system (especially in the liquid mixing stage) can be eliminated or inhibited, thereby further improving the mechanical properties of the modified white carbon black, and the water resistance, solvent resistance, etc. By adding a dispersing agent, it is beneficial to improve the uniformity of the dispersion of the powder, and further improve the uniformity of the curing. By adding a colorant, the modified white carbon black can be given a specific appearance color, further expanding the application range. By adding an organic wax, through lubrication, migration or film formation, the gloss, wear resistance, scratch resistance, etc. of the powder are further improved.
[0016] In some embodiments, the amount of the curing monomer and / or oligomer added is 0.1wt% to 60wt% of the total mass of the white carbon black. Preferably, the amount of the curing monomer and / or oligomer added is 3wt% to 35wt% of the total mass of the white carbon black. In the above technical solution, the content of the high molecular polymer in the product can be adjusted by the amount of the curing monomer and / or oligomer, so as to adjust the performance improvement effect of the modified white carbon black.
[0017] In some embodiments, the conditions for mixing the silica wet gel with the modifier include a temperature of 0°C to 99°C and a time of 5min to 72h. Controlling the temperature and time in a suitable range is beneficial to further improve the uniformity of the mixing of the modifier in the silica wet gel, and is beneficial to the uniform wetting and spreading of the curing monomer and / or oligomer, thereby being beneficial to improving the curing modification effect.
[0018] Preferably, the conditions for mixing the silica wet gel with the modifier include a temperature of 40°C to 60°C and a time of 1h to 4h.
[0019] In some embodiments, mixing the silica wet gel with the modifier comprises: emulsifying the mixture of the curing monomer and / or oligomer, the emulsifying agent, and water to form a modified emulsion; mixing the silica wet gel and the modified emulsion.
[0020] In the above technical solution, by forming an emulsion and mixing with the silica wet gel, it is beneficial to further improve the uniformity of the dispersion of the curing monomer and / or oligomer in the silica wet gel.
[0021] Preferably, the mass ratio of the solidified monomer and / or oligomer, the emulsifier and the water is 1: (0.1-0.5): (5-10).
[0022] Preferably, the emulsifying step comprises high-speed shearing emulsification at a speed of 5000 rpm-15000 rpm at 0℃-80℃.
[0023] In some embodiments, the drying method comprises at least one of spray drying, flash evaporation or vacuum drying, and the pulverizing method comprises at least one of air flow pulverization, ultrasonic pulverization, plasma pulverization, microwave-assisted pulverization, acoustic resonance pulverization, magnetic field-assisted high-energy ball milling, laser pulverization or grinding. The solidified monomer and / or oligomer can be processed to a target particle size by the above drying and pulverizing methods.
[0024] Preferably, the drying and pulverizing of the mixture in sequence comprises spray drying and air flow pulverization of the mixture in sequence.
[0025] Preferably, the drying temperature is lower than 100℃. Further preferably, the drying temperature is 60℃-100℃.
[0026] Preferably, the particle size of the white carbon black is 0.1 μm-500 μm. The solidified monomer and / or oligomer can be processed to a target particle size by drying and pulverizing.
[0027] Preferably, the particle size of the white carbon black is 1 μm-200 μm.
[0028] In some embodiments, the method for preparing the silica wet gel comprises mixing sodium silicate, an acidifying agent and water, acidifying, aging, filtering and washing to obtain the silica wet gel.
[0029] Preferably, the method for preparing the silica wet gel comprises adding an acidifying agent to an aqueous solution of sodium silicate to form a mixed system under stirring at 30℃-60℃, controlling the pH value of the mixed system to be 9-10, adding the acidifying agent to the mixed system until the pH value is 3-4, i.e. the acidification is completed, continuing to stir and age for 1h-4h, then filtering and washing the residue until the conductivity is less than 100 μs / cm to obtain the silica wet gel.
[0030] In the above technical solution, the silica wet gel is prepared by the precipitation method, i.e. acidification, aging, precipitation and control of reaction conditions, which is low in production cost, simple and controllable in operation, and high in product quality.
[0031] Preferably, the acidifying agent comprises at least one of sulfuric acid, hydrochloric acid or carbonic acid.
[0032] Preferably, the mass concentration of the aqueous solution of sodium silicate is 5wt%-15wt%, and the modulus is 2.5-3.5.
[0033] Preferably, the rotation speed of the stirring is 200rpm-500rpm. In a second aspect, the embodiments of the present application provide a modified white carbon black prepared by the above preparation method. The modified white carbon black comprises white carbon black and a polymer penetrating into the interior of the white carbon black and adhering to the surface of the white carbon black.
[0034] In the above technical solution, the modified white carbon black prepared by the above preparation method has the polymer uniformly coated on the surface and uniformly penetrated into the interior, can greatly improve the compatibility with the resin matrix, reduce agglomeration, effectively enhance the interfacial bonding force with the resin matrix, and can impart the modified white carbon black with specific properties through the type of the polymer, thereby effectively expanding the application field.
[0035] In some embodiments, the particle size of the modified white carbon black is 0.1μm-500μm. Preferably, the particle size of the modified white carbon black is 1μm-200μm.
[0036] In a third aspect, the embodiments of the present application provide the application of the above modified white carbon black in preparing paints and inks, plastics, rubbers, films, electronic products, cosmetics, advanced ceramics, microelectronics, aerospace, biopharmaceuticals or optical detection products. BRIEF DESCRIPTION OF DRAWINGS
[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.
[0038] Figure 1 The process flow chart of the preparation method of the modified white carbon black provided by the embodiments of the present application. DETAILED DESCRIPTION
[0039] Hereinafter, the modified white carbon black and the preparation method and application thereof in the present application will be described in detail with appropriate reference to the drawings, but there will be cases of omitting unnecessary detailed description. For example, there are cases of omitting detailed description of matters well known and repeated description of actually identical structures. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following description are provided to enable those skilled in the art to fully understand the present application, and are not intended to limit the subject matter recited in the claims.
[0040] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values listed are 1 and 2, and if the maximum range values listed are 3, 4, and 5, then the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, wherein a and b are both real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, stating that a parameter is an integer ≥ 2 is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
[0041] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. Unless otherwise specified, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution. Unless otherwise specified, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, it is mentioned that the method may also include step (c), which means that step (c) can be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
[0042] Figure 1 This is a process flow chart of the preparation method of modified silica provided in the examples of this application. Figure 1 The present invention provides a method for preparing modified silica, comprising the following steps: S1: Mixing a wet silica gel prepared by a precipitation method or a sol-gel method with a modifier to obtain a mixture; wherein the modifier includes a curing monomer and / or an oligomer.
[0043] It is appreciated that the silica wet gel can be prepared by a method conventional in the art, such as a precipitation method or a sol-gel method, which is not specifically limited in the present application.
[0044] In some embodiments, the method for preparing the silica wet gel by the precipitation method can include: mixing sodium silicate, an acidifying agent and water, acidifying, aging, filtering and washing to obtain the silica wet gel.
[0045] It is appreciated that the sodium silicate first undergoes a metathesis reaction with the acidifying agent to form a silica gel, then the gel is aged to promote colloidal polymerization and structural stability, and then the impurities are removed by filtering and washing to obtain a silica wet gel with high purity.
[0046] In other embodiments, the method for preparing the silica wet gel by the sol-gel method can include: hydrolysis and condensation of an organosilicon compound (such as tetraethyl orthosilicate) in an acidic or alkaline aqueous solution system to form a sol, continued polycondensation by heating to form a gel, and finally aging to obtain the silica wet gel.
[0047] Further, the method for preparing the silica wet gel by the precipitation method includes: (1) under the conditions of 30°C to 60°C and stirring, an acidifying agent is added to a sodium silicate aqueous solution to form a mixed system, and the pH value of the mixed system is controlled to be 9 to 10.
[0048] By way of example, the temperature in step (1) can be 30°C, 40°C, 50°C, 60°C or any intermediate value between any two of the above values. Controlling the reaction temperature is conducive to controlling the reaction rate.
[0049] Further, the acidifying agent includes at least one of sulfuric acid, hydrochloric acid or carbonic acid. Preferably, the acidifying agent includes sulfuric acid.
[0050] Further, the mass concentration of the sodium silicate aqueous solution is 5wt% to 15wt%, and the modulus is 2.5 to 3.5. By way of example, the mass concentration of the sodium silicate aqueous solution can be 5wt%, 8wt%, 10wt%, 12wt%, 15wt% or any intermediate value between any two of the above values; and the modulus can be 2.5, 2.8, 3.0, 3.2, 3.5 or any intermediate value between any two of the above values.
[0051] Herein, the modulus of the sodium silicate aqueous solution refers to the molar ratio of silicon dioxide (SiO2) to sodium oxide (Na2O).
[0052] Further, the pH value of the mixed system can be controlled to be 9, 9.2, 9.5, 9.8, 10 or any intermediate value between any two of the above values.
[0053] Further, the stirring speed is 200 rpm to 500 rpm. As an example, the stirring speed can be 200 rpm, 300 rpm, 400 rpm, 500 rpm, or any value between any two of the values. The stirring can avoid local over-acidification that causes particle agglomeration.
[0054] (2) adding acidifying agent to the mixed system until the pH is 3 to 4, i.e., the acidification is completed, continuing to stir and age for 1 h to 4 h, then filtering and washing the residue until the conductivity is less than 100 μs / cm, to obtain a silica wet gel.
[0055] Further, in step (2), the acidifying agent can be slowly added dropwise to the mixed system until the pH is 3 to 4. The stirring and aging time can be 1 h, 2 h, 3 h, 4 h, or any value between any two of the values. Controlling the stirring and aging time is conducive to promoting the stability of the powder crystal form.
[0056] In step (2), filtering and washing the residue until the conductivity is less than 100 μs / cm can effectively remove residual Na + , SO4 2- , and other impurity ions.
[0057] In some embodiments, the curing monomer is an unsaturated monomer.
[0058] Further, the curing monomer is an unsaturated monomer capable of EB curing.
[0059] Further, the unsaturated monomer includes at least one of a monofunctional unsaturated monomer, a bifunctional unsaturated monomer, or a multifunctional unsaturated monomer.
[0060] Further, the unsaturated monomer includes at least one of an acrylic acid and derivatives thereof, an acrylamide and derivatives thereof, a vinyl, a maleic acid derivative, an allyl, or a fluorine-containing olefin.
[0061] As an example, the unsaturated monomer includes at least one of acrylic acid (AA), methacrylic acid (MAA), itaconic acid (IA), acrylamide (AM), N-vinyl pyrrolidone (NVP), sodium styrene sulfonate (SSS), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), n-butyl methacrylate (NBMA), hydroxyethyl methacrylate (HEMA), hydroxypropyl acrylate (HPA), polyethylene glycol diacrylate (PEGDA), trimethylolpropane triacrylate (TMPTA), methacryloyloxyethyl trimethyl ammonium chloride (DMC), maleic anhydride (MAH), glycidyl acrylate (GMA), dodecyl methacrylate (DMA), butyl acrylate (BA), hexafluorobutyl methacrylate (HFBMA), perfluorooctyl ethyl acrylate (FOEA), vinyl trimethoxysilane (VTMS), methacryloyloxypropyl trimethoxysilane (MAPTMS), dioctyl maleate (DOM), allyloxy surfactant monomer, 1,1-difluoroethylene.
[0062] In some embodiments, the oligomer includes at least one of an acrylate, a vinyl, a vinyl ether, a silicone acrylate, an epoxy, a polyurethane, a phenol-formaldehyde resin, or a silicone.
[0063] As an example, the oligomer includes at least one of an epoxy acrylate (EA), a polyurethane acrylate (PUA), a polyester acrylate (PEA), a polyether acrylate, a hydroxyl-terminated polybutadiene (HTPB).
[0064] In some embodiments, the modifier further includes a curing aid. Further, the curing aid includes at least one of an initiator, a catalyst, or a curing agent. When a curing method other than EB curing is used, the curing aid is added to initiate the curing reaction.
[0065] In some embodiments, the modifier further includes at least one of a coupling agent, a leveling agent, a defoaming agent, a dispersant, a colorant, or an organic wax.
[0066] Further, the coupling agent includes a silane, a titanate, an aluminate, a zirconium aluminate, an organic complex, a phosphate coupling agent, etc. Further preferably, the coupling agent is a silane coupling agent with a vinyl group.
[0067] Further, the leveling agent includes a silicone, an acrylic, an organofluorine-modified silicone, a wax, a polyester-modified silicone, etc.
[0068] Further, the defoaming agent can include a silicone (such as BYK-066N), a powder defoaming agent (such as FoamStar PB 2941, FoamStar PB 2922, etc.), a mineral oil, a polyether, etc.
[0069] Further, the colorant can include an organic colorant or an inorganic colorant, and can be a color paste or a color powder. As an example, the inorganic colorant can be carbon black, titanium dioxide, zinc sulfide, iron oxide, chromium oxide, nickel oxide, chromium oxide, antimony oxide, titanium oxide, cobalt oxide, and bismuth vanadate, etc.; the organic colorant can be azo, phthalocyanine, polycyclic, such as phthalocyanine, triphenylmethane, anthraquinone (cyan / blue), monoazo / diazo complex (magenta / red), lemon yellow (yellow), diazo / polyazo complex, azo / metal complex, etc.
[0070] Further, the organic wax powder can be a PP wax powder and a PE wax powder, etc.
[0071] Further, the dispersant can include an anionic surfactant, such as sodium dodecyl benzene sulfonate (SDBS), sodium dioctyl sulfosuccinate, etc., or a non-ionic surfactant, such as polyoxyethylene octylphenol ether (OP-10), polyoxyethylene sorbitan ester (Tween series), etc.; and can also include a polycarboxylate dispersant (such as BYK-110, EFKA-4046, etc.), a polyurethane type dispersant, etc.
[0072] In some embodiments, the conditions for mixing the silica wet gel with the modifier include a temperature of 0°C to 99°C and a time of 5 minutes to 72 hours.
[0073] As an example, the temperature for mixing the silica wet gel with the modifier is 0°C, 10°C, 20°C, 50°C, 70°C, 99°C, or any intermediate value between any two of the above values, and the time is 5 minutes, 30 minutes, 1 hour, 5 hours, 10 hours, 24 hours, 72 hours, or any intermediate value between any two of the above values.
[0074] Further, the conditions for mixing the silica wet gel with the modifier include a temperature of 40°C to 60°C and a time of 1 hour to 4 hours.
[0075] In some embodiments, mixing the silica wet gel with the modifier includes: emulsifying the solidified monomer and / or oligomer, the emulsifier, and the water after mixing to form a modified emulsion; mixing the silica wet gel and the modified emulsion.
[0076] Further, the mass ratio of the solidified monomer and / or oligomer, the emulsifier, and the water is 1:(0.1-0.5):(5-10).
[0077] Further, the emulsifying step includes high-speed shearing emulsification at a speed of 5000 rpm to 15000 rpm at a temperature of 0°C to 80°C.
[0078] S2: sequentially drying and crushing the mixture to obtain the white carbon black containing the cured monomer and / or oligomer.
[0079] In some embodiments, the cured monomer and / or oligomer accounts for 0.1wt~60wt% of the total mass of the white carbon black. As an example, the added amount of the cured monomer and / or oligomer accounts for 0.1wt, 1wt%, 10wt%, 20wt%, 40wt%, 60wt% or any intermediate value between any two of the above values of the total mass of the white carbon black.
[0080] Further, the added amount of the cured monomer and / or oligomer accounts for 3wt~35wt% of the total mass of the white carbon black.
[0081] In some embodiments, the drying method includes at least one of spray drying, flash or vacuum drying.
[0082] In some embodiments, the drying temperature is lower than 100℃. As an example, the drying temperature can be 20℃, 30℃, 50℃, 60℃, 80℃, 100℃ or any intermediate value between any two of the above values.
[0083] Further, the drying temperature is 60℃~100℃.
[0084] In some embodiments, the crushing method includes at least one of air flow crushing, ultrasonic crushing, plasma crushing, microwave-assisted crushing, acoustic resonance crushing, magnetic field-assisted high-energy ball milling, laser crushing or grinding.
[0085] In some embodiments, the air flow crushing (air flow mill) can include supersonic air flow crushing (steam kinetic energy mill); the grinding can include ball milling, vibration milling, etc.
[0086] Further, the sequentially drying and crushing the mixture includes sequentially spray drying and air flow crushing the mixture.
[0087] In some embodiments, the particle size of the white carbon black is 0.1μm~500μm. As an example, the particle size of the white carbon black is 0.1μm~5μm, 2μm~8μm, 10μm~50μm, 50μm~100μm, 100μm~500μm, etc.
[0088] Further, the particle size of the white carbon black is 1μm~200μm. Still further, the particle size of the white carbon black is 2μm~8μm.
[0089] S3: curing the cured monomer and / or oligomer in the white carbon black to obtain the modified white carbon black.
[0090] In some embodiments, the curing method includes at least one of UV curing, EB curing, microwave curing, laser curing, thermal curing or standing curing.
[0091] For example, the conditions for UV curing can include a power of 20 mW to 20 kW and a time of 0.1 s to 8 h; the conditions for EB curing can include a voltage of 10 kV to 500 kV and an electron beam dose of 30 kGy to 60 kGy; the conditions for thermal curing can include a temperature of 80°C to 180°C and a time of 1 s to 8 h; and the time for static curing can be 1 day to 90 days.
[0092] Preferably, the curing method includes EB curing.
[0093] When the curing method is EB curing, the silica containing the cured monomers and / or oligomers can be scattered by high-pressure nitrogen gas and then rapidly cured in an EB curing area.
[0094] In addition, the application also provides a modified silica prepared by the above preparation method, which includes silica and a polymer attached to the surface of the silica and penetrating into the interior of the silica.
[0095] In some embodiments, the particle size of the modified silica is 0.1 μm to 500 μm. Preferably, the particle size of the modified silica is 1 μm to 200 μm.
[0096] In addition, the application also provides the use of the above modified silica in the preparation of paints and inks, plastics, rubber, films, electronic products, cosmetics, advanced ceramics, microelectronics, aerospace, biopharmaceuticals, or optical detection products.
[0097] For example, the modified silica can be used as a matting powder in the paint and ink system, which can effectively improve the dispersibility, compatibility, water resistance, solvent resistance, stability, dust resistance, and matting performance.
[0098] Hereinafter, the embodiments of the application are described. The embodiments described below are exemplary and are only used to explain the application and cannot be understood as a limitation of the application. If the specific technology or condition is not specified in the embodiments, the technology or condition described in the literature in the art or according to the product manual is used. If the reagent or instrument is not specified by the manufacturer, it is a conventional product that can be obtained by market purchase.
[0099] Example 1 The present embodiment provides a modified silica, and a preparation method thereof includes the following steps: (1) Dilute the aqueous sodium silicate solution to a modulus of 3.0 and a concentration of 10wt% at 50°C and a rotation speed of 300 rpm, mix with sulfuric acid by stirring, control the pH to be 9-10 to form a silica sol, continue to add an acidifying agent to adjust the pH to 3-4, promote the silica sol to form flocculent precipitate, stir and age for 2h, filter and wash to obtain a silica wet gel.
[0100] (2) Stir and mix the silica wet gel with the modifier (polyester acrylate PEA: trimethylolpropane triacrylate TMPTA: n-butyl methacrylate NBMA = 2:4:4) at 60°C for 2h to obtain a mixture.
[0101] (3) Spray dry and jet mill the mixture in sequence to obtain white carbon black with a particle size of 2-8μm.
[0102] (4) EB-cure the white carbon black powder to obtain modified white carbon black.
[0103] Example 2 The modified white carbon black of this example is prepared by a method different from that of Example 1, which is characterized in that: In step (2), (polyester acrylate PEA: trimethylolpropane triacrylate TMPTA: n-butyl methacrylate), emulsifier sodium dodecyl sulfate (SDS) and water are sheared at a mass ratio of 1:0.2:6 at 50°C to obtain a modified emulsion.
[0104] Stir and mix the silica wet gel with the modified emulsion at 60°C for 2h to obtain a mixture.
[0105] The modified white carbon black prepared in Example 1 above is used as a matting powder, and is compared with the matting powder product Winkler OK520 (Comparative Example 1) already on the market, unmodified white carbon black (Comparative Example 2), and the white carbon black of step (3) of Example 1 which has not been cured (Comparative Example 2) to prepare paint films for comparison and application. The specific paint film raw material composition is shown in Table 1.
[0106] In Table 1, "parts" are mass parts; the resin is acrylic resin GNU2450 (Guangzhou Jiaxin New Materials); the mixed solvent is butyl acetate / xylene / PMA = 5 / 3 / 2; the ratio of auxiliaries including defoamer and leveling agent is 3:1, wherein the leveling agent is 10% BYK333 (Borchem), and the defoamer is BYK141 (Borchem).
[0107] Table 1 Paint composition of paint film
[0108] The matting powder and paint film prepared in the above embodiment 1, comparative example 1 and comparative examples 1-2 were subjected to performance tests, and the test results are shown in Table 2. The specific test methods are as follows: (1) Wet dispersibility: the paint was subjected to high-speed stirring at a speed of 1200 rpm-1500 rpm, and the time required for the fineness to be qualified (≤25 μm) was determined, and the shorter the time, the better the wet dispersibility of the matting powder.
[0109] (2) Water resistance: the paint film was immersed in water, and the time when the appearance changed obviously was recorded. Among them, the appearance changed obviously refers to bubbling, wrinkling, peeling or discoloration, etc.
[0110] (3) Solvent resistance: the paint film was immersed in ethanol, and the time when the appearance changed obviously was recorded. Among them, the appearance changed obviously refers to bubbling, wrinkling, peeling or discoloration, etc.
[0111] (4) Stability: the paint was placed for 60 days, then the dried film was sprayed on the board, and the gloss value was compared with the initial gloss value of the paint film, and the change rate ≤5% was grade 1, and >5% was grade 2.
[0112] (5) Compatibility: the transparency of the matting powder when added by 5% in the acrylic resin system, polyurethane resin system, epoxy resin system and polyester resin system was observed. The completely transparent was grade 1, semi-transparent was grade 2, and opaque was grade 3, and the average value was taken.
[0113] (6) Anti-settling property: the paint was stored for 3 days in the natural environment, and the degree of sedimentation was observed. The judgment criteria are as follows: 10 levels: no sedimentation; 8 levels: slight sedimentation (sedimentation layer <5% of the total volume); 6 levels: moderate sedimentation (5%-15% of the total volume); 4 levels: more serious sedimentation (15%-30% of the total volume); 2 levels: serious sedimentation (>30% of the total volume); 0 levels: hard sedimentation cannot be dispersed.
[0114] (7) Matting efficiency: the gloss value was measured by a gloss meter (Haze-Gloss, made by BYK-Garner Company) under the condition of 60 degrees-60 degrees, and the evaluation was carried out according to the following evaluation criteria. (Evaluation criteria) A level: the gloss value is below 40%, and the matting property is good; B level: the gloss value is more than 40%, and the matting property is insufficient.
[0115] Table 2 Performance test results
[0116] As can be seen from Table 1 and Table 2, compared with the matting powder product on the market in comparative example 1, the unmodified white carbon black in comparative example 1 and the unmodified white carbon black in comparative example 2, the modified white carbon black in the present application has better wet dispersibility, water resistance, solvent resistance and anti-settling property, and still has good compatibility and matting efficiency after modification.
[0117] The embodiments described above are only part of the embodiments of the present application, rather than all the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application claimed, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative labor are within the scope of protection of the present application.
Claims
1. A method for preparing modified silica, characterized in that: The following steps are involved: Mixing a wet silica gel prepared by a precipitation method or a sol-gel method with a modifier to obtain a mixture; wherein the modifier includes a curing monomer and / or an oligomer; The mixture is dried and crushed in sequence to obtain white carbon black containing curing monomers and / or oligomers; The curing monomers and / or oligomers in the white carbon black are cured to obtain modified white carbon black.
2. The method for preparing modified silica according to claim 1, wherein The curing method includes at least one of UV curing, EB curing, microwave curing, laser curing, thermal curing or static curing; Preferably, the curing method includes EB curing; Preferably, the modifier further comprises a curing aid; Preferably, the curing aid includes at least one of an initiator, a catalyst or a curing agent.
3. The method for preparing modified silica according to claim 1, wherein The curing monomer is an unsaturated monomer; Preferably, the curing monomer is an unsaturated monomer capable of EB curing; Preferably, the unsaturated monomer includes at least one of a monofunctional unsaturated monomer, a difunctional unsaturated monomer or a multifunctional unsaturated monomer; Preferably, the unsaturated monomer includes at least one of acrylic acid and its derivatives, acrylamide and its derivatives, vinyl, maleic acid derivatives, allyl or fluorine-containing olefins; Preferably, the oligomer comprises at least one of acrylates, vinyls, vinyl ethers, silicone acrylates, epoxies, polyurethanes, phenolics or silicones.
4. The method for preparing modified silica according to claim 1, wherein The modifier further comprises at least one of a coupling agent, a leveling agent, a defoaming agent, a dispersant, a colorant or an organic wax.
5. The method for preparing modified silica according to claim 1, wherein The added amount of the curing monomer and / or oligomer accounts for 0.1wt% to 60wt% of the total mass of the white carbon black; Preferably, the added amount of the curing monomer and / or oligomer accounts for 3 wt% to 35 wt% of the total mass of the silica.
6. The method for preparing modified silica according to claim 1, wherein The conditions for mixing the wet silica gel with the modifier include: a temperature of 0° C. to 99° C. and a time of 5 minutes to 72 hours; Preferably, the conditions for mixing the silicon dioxide wet gel with the modifier include: a temperature of 40° C. to 60° C. and a time of 1 hour to 4 hours.
7. The method for preparing modified silica according to claim 1, wherein Mixing the silicon dioxide wet gel with a modifier comprises: mixing the curing monomer and / or oligomer, emulsifier and water and emulsifying the mixture to form a modified emulsion; mixing the silicon dioxide wet gel and the modified latex; Preferably, the mass ratio of the curing monomer and / or oligomer, the emulsifier and the water is 1:(0.1-0.5):(5-10); Preferably, the emulsification step comprises: performing high-speed shear emulsification at a temperature of 0°C to 80°C and a rotation speed of 5000rpm to 15000rpm.
8. The method for preparing modified silica according to claim 1, wherein: The drying method includes at least one of spray drying, flash evaporation or vacuum drying, and the pulverization method includes at least one of air flow pulverization, ultrasonic pulverization, plasma pulverization, microwave-assisted pulverization, acoustic resonance pulverization, magnetic field-assisted high-energy ball milling, laser pulverization or grinding; Preferably, sequentially drying and pulverizing the mixture comprises: sequentially spray drying and air flow pulverizing the mixture; Preferably, the drying temperature is lower than 100°C; Preferably, the drying temperature is 60°C to 100°C; Preferably, the particle size of the white carbon black is 0.1 μm to 500 μm; Preferably, the particle size of the white carbon black is 1 μm to 200 μm.
9. The method for preparing modified silica according to claim 1, wherein: The preparation method of the silicon dioxide wet gel comprises: mixing sodium silicate, an acidifying agent and water, acidifying, aging, filtering and washing to obtain the silicon dioxide wet gel; Preferably, the preparation method of the wet silica gel comprises: adding an acidifying agent to an aqueous solution of sodium silicate at 30° C. to 60° C. under stirring conditions to form a mixed system, and controlling the pH value of the mixed system to be 9 to 10; adding the acidifying agent to the mixed system until the pH reaches 3 to 4, i.e., completing the acidification; continuing stirring and aging for 1 to 4 hours; and then filtering and washing the filter residue until the conductivity is less than 100 μs / cm to obtain the wet silica gel; Preferably, the acidifying agent comprises at least one of sulfuric acid, hydrochloric acid or carbonic acid; Preferably, the mass concentration of the aqueous solution of sodium silicate is 5wt%~15wt%, and the modulus is 2.5~3.5; Preferably, the stirring speed is 200 rpm to 500 rpm.
10. A modified silica, characterized in that: The modified silica is prepared by the preparation method according to any one of claims 1 to 9, and includes silica and a high molecular polymer attached to the surface of the silica and permeated into the interior of the silica.
11. The modified silica according to claim 10, characterized in that The particle size of the modified silica is 0.1 μm to 500 μm; Preferably, the particle size of the modified silica is 1 μm to 200 μm.
12. Use of the modified silica according to claim 10 or 11 in the preparation of coatings and inks, plastics, rubbers, films, electronic products, cosmetics, advanced ceramics, microelectronics, aerospace, biopharmaceuticals or optical detection products.