High performance flame retardant inkjet ink and method of making same

Abstract

The application relates to the technical field of flame-retardant materials, and discloses high-performance flame-retardant inkjet ink, which comprises the following components in percentage by mass: ammonium polyphosphate 20-35%; organosiloxane 8-15%; melamine polyphosphate 10-20%; modified montmorillonite 5-10%; nanosilicate 2-8%; boron nitride flake 1-5%; rare earth oxide 0.5-2%; color paste 2-10%; dispersant 1-3%; film-forming aid 1-3%; viscosity regulator 2-6%; and deionized water 25-35%. Through the synergistic effect of ammonium polyphosphate and melamine polyphosphate, a continuous and dense carbon layer is formed under high-temperature environment; compared with the single-scale enhanced flame-retardant system in the prior art, the carbon layer structure is continuously optimized at multiple temperature stages, and the defects of easy cracking and weak oxidation resistance of the carbon layer are overcome.

Description

Technical Field

[0001] This invention relates to the field of flame retardant materials technology, specifically to a high-performance flame retardant inkjet ink and its preparation method. Background Technology

[0002] With rapid industrialization and urbanization, the increasing risk of fire has led to a growing demand for flame-retardant materials in fields such as construction, electronics, and transportation. Against this backdrop, flame-retardant coatings and inks have gradually gained widespread attention due to their ease of application and multifunctionality.

[0003] The flame-retardant properties of existing flame-retardant inks typically rely on a single char-forming agent (such as ammonium polyphosphate) or a simple char-forming filler (such as silicate) to generate a char layer through high-temperature decomposition. However, this single-function char layer often exhibits crack propagation and increased porosity at high temperatures, significantly reducing the thermal barrier function of the char layer and thus affecting its flame-retardant performance.

[0004] Current research indicates that the density and mechanical properties of the char layer directly determine its resistance to high-temperature oxidation and its heat insulation effect. However, in traditional flame-retardant systems, the char layer formation path is singular and lacks a dynamic reinforcement mechanism, making it difficult to effectively inhibit crack propagation. This deficiency causes existing flame-retardant inks to exhibit char layer embrittlement and decreased flame-retardant performance when exposed to high temperatures for extended periods.

[0005] For example, while traditional phosphorus-based flame retardants can catalyze char formation in the early stages of combustion, the char formation efficiency is limited, and the char layer structure is loose. In addition, although the ceramicization reaction of silicon-based materials at high temperatures can improve some char layer properties, its poor dispersibility and single reaction window result in insufficient synergy. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a high-performance flame-retardant inkjet ink and its preparation method, solving the problem of insufficient carbon layer density in existing flame-retardant inkjet inks.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-performance flame-retardant inkjet ink, comprising the following components by mass percentage:

[0008] Ammonium polyphosphate: 20%–35%;

[0009] Organosiloxanes: 8%–15%;

[0010] Melamine polyphosphate: 10%–20%;

[0011] Modified montmorillonite: 5%–10%;

[0012] Nano-silicate: 2%–8%;

[0013] Boron nitride thin films: 1%–5%;

[0014] Rare earth oxides: 0.5%–2%;

[0015] Pigment: 2%–10%;

[0016] Dispersant: 1%–3%;

[0017] Film-forming aids: 1%–3%;

[0018] Viscosity modifier: 2%–6%;

[0019] Deionized water: 25%–35%.

[0020] Preferably, the thermal decomposition temperature of the pigment is ≥400℃.

[0021] Preferably, the modified montmorillonite is modified with a silane coupling agent, and the amount of silane coupling agent is 0.5% to 2% of the mass of the modified montmorillonite.

[0022] Preferably, the rare earth oxide is cerium oxide.

[0023] Preferably, the dispersant is polyvinylpyrrolidone.

[0024] Preferably, the film-forming aid is ethylene glycol monobutyl ether, and the viscosity modifier is polyethylene glycol.

[0025] A method for preparing high-performance flame-retardant inkjet ink includes the following steps:

[0026] S1. Modified montmorillonite and nano-silicate are mixed to obtain nano-composite particles;

[0027] S2. Mix ammonium polyphosphate and melamine polyphosphate, add deionized water and stir to form a flame-retardant base slurry;

[0028] S3. Add the dynamic reinforcing component, nanocomposite particles, color paste and auxiliary components to the flame retardant base slurry in sequence, and stir evenly;

[0029] S4. Perform ultrasonic dispersion treatment on the mixture;

[0030] S5. The ink is obtained by sequentially passing through filtration and vacuum degassing processes.

[0031] Preferably, step S1 includes treating modified montmorillonite and nano-silicate in a ratio of 2:1 to 5:1 in a ball mill at a speed of 100 to 300 rpm for 2 to 4 hours.

[0032] Preferably, the ultrasonic dispersion treatment time in step S4 is 15 to 30 minutes, and the temperature is 25 to 40°C.

[0033] Preferably, the filter membrane used in step S5 has a pore size of 0.2 μm, the vacuum degree of the vacuum degassing process is -0.08 to -0.1 MPa, and the time is 15 to 30 minutes.

[0034] This invention provides a high-performance flame-retardant inkjet ink and its preparation method. It has the following beneficial effects:

[0035] 1. This invention utilizes the synergistic effect of ammonium polyphosphate and melamine polyphosphate, combined with the dynamic release of nano-silicates and boron nitride flakes, to form a continuous and dense char layer under high temperature conditions. Compared with the single-scale enhanced flame retardant system in the prior art, this invention continuously optimizes the char layer structure at multiple temperature stages, overcoming the shortcomings of the char layer being easy to decompose and having weak oxidation resistance.

[0036] 2. This invention optimizes the type and particle size of the pigment paste, selects inorganic pigments with excellent thermal stability and specific dispersants, ensuring the pigment stability at high temperatures without interfering with the decomposition pathway of the flame-retardant base material. This not only improves the coloring ability of the ink but also enhances the density of the carbon layer under high-temperature conditions.

[0037] 3. This invention employs a stepwise processing technology of modified nanoparticles and dynamic reinforcing components. Through precise parameter control of processes such as mechanochemistry, ultrasonic dispersion, and vacuum degassing, the dispersibility and uniformity of flame-retardant ink are improved. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the preparation method steps of the present invention. Detailed Implementation

[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Please see the appendix Figure 1 Example 1: Preparation of Flame Retardant Ink with Multi-Scale Synergistic Enhancement of Dynamic Carbon Layers

[0041] Nanofiller pretreatment: Modified montmorillonite (MMT) and nano silicate (NS) were mixed at a mass ratio of 3:1 and placed in a ball mill. The mixture was treated at 150 rpm for 3 hours. Then, silane coupling agent (SCA) (at a mass ratio of 1% of the total filler mass) was added and stirred at 70°C for 90 minutes to obtain nanocomposite particles.

[0042] Preparation of flame retardant base material: Ammonium polyphosphate (APP) and melamine polyphosphate (MPP) are mixed at a mass ratio of 2:1. Deionized water (DI water) is added (solid-liquid ratio 1:4), and the mixture is stirred at 350 rpm for 20 minutes to form a homogeneous slurry.

[0043] Dynamic reinforcement component addition: Polydimethylsiloxane emulsion (PDMS emulsion, 10% by mass) and boron nitride nanosheets (BN, 3% by mass) were added sequentially to the base slurry along with the aforementioned nanocomposite particles. The stirring speed was controlled at 600 rpm for 40 minutes.

[0044] Addition of pigments and additives: Carbon black pigment (CB, 5%, particle size 100 nm), polyvinylpyrrolidone dispersant (PVP, 2%), ethylene glycol monobutyl ether (EGBE, 2%, film-forming aid), polyethylene glycol (PEG, 4%, viscosity modifier), and rare earth oxide (REO, cerium oxide, 1% by mass).

[0045] The mixture was treated in an ultrasonic disperser for 25 minutes at a temperature controlled at 30°C.

[0046] Filtration and degassing: Large particles are removed by filtration using a 0.2μm pore size filter membrane. Vacuum degassing (-0.09MPa) for 25 minutes yields flame-retardant inkjet ink.

[0047] Example 2: Preparation of ink with optimized compatibility of color paste and flame retardant properties

[0048] Nanofiller pretreatment: Modified montmorillonite (MMT) and nanosilicate (NS) were mixed in a 2:1 ratio. The mixture was then treated using a ball mill at 200 rpm for 4 hours.

[0049] Flame retardant base material preparation: APP and MPP are mixed in a 3:1 ratio, DI Water (solid-liquid ratio 1:3) is added, and the mixture is stirred at 400 rpm for 30 minutes.

[0050] Dynamic reinforcement component addition: PDMS emulsion (12% by mass), BN (4% by mass), and the aforementioned nanofiller were added to the base slurry; the stirring speed was 700 rpm and the stirring time was 50 minutes.

[0051] Addition of pigments and additives: Add iron oxide pigment (IOP, 7% by mass, 80 nm particle size), PVP dispersant (2%), EGBE (2%, film-forming aid), PEG (3%, viscosity modifier), and REO (cerium oxide, 1.5% by mass), and treat with an ultrasonic disperser for 30 minutes.

[0052] Filtration and degassing: Filtration was performed using a 0.2μm pore size filter membrane, followed by vacuum degassing (-0.1MPa) for 30 minutes.

[0053] Example 3: Ink Preparation with Optimized Refined Processes

[0054] Nanofiller pretreatment: Modified montmorillonite (MMT) and nano silicate (NS) were mixed at a mass ratio of 3:1 and ball-milled at 150 rpm for 3.5 hours. SCA (mass fraction 1.2%) was added and stirred at 70°C for 1.5 hours.

[0055] Flame retardant base material preparation: APP and MPP are mixed at a mass ratio of 3:1, DI Water (solid-liquid ratio 1:4) is added, and the mixture is stirred at 400 rpm for 25 minutes to form a uniform base material slurry.

[0056] Dynamic enhancement components added: PDMS emulsion (10% by mass), BN (5% by mass), and the aforementioned nanocomposite particles. Stir at 600 rpm for 45 minutes.

[0057] Add the following color paste and additives: IOP (5% by mass), PVP dispersant (2%), EGBE (2%, film-forming aid), PEG (4%, viscosity modifier), REO (cerium oxide, 1.8% by mass), and ultrasonically disperse for 20 minutes.

[0058] Filtration and degassing: After filtration using a 0.2μm filter membrane, degas under vacuum (-0.09MPa) for 20 minutes.

[0059] Comparative Example 1: Preparation of Flame Retardant Ink Without Dynamic Reinforcement

[0060] Nanofiller pretreatment: The mixing treatment of montmorillonite and nanosilicate is omitted, and untreated montmorillonite particles (unmodified) are added directly without adding silane coupling agent.

[0061] Preparation of flame retardant base material: Ammonium polyphosphate and melamine polyphosphate are directly mixed without slurry stirring and used directly as base material.

[0062] Dynamic enhancement component addition: Do not add PDMS, only add APP and MPA, reduce the stirring speed to 300 rpm, and the time is 10 minutes.

[0063] Addition of color paste and additives: Add undispersed carbon black (particle size 500nm), and add dispersant and film-forming aid in the usual proportion, but without ultrasonic dispersion treatment.

[0064] Filtration and degassing: The filter membrane pore size was adjusted to 1μm, and the vacuum degassing time was reduced to 10 minutes.

[0065] Comparative Example 2: Preparation of Unoptimized Pigment Flame Retardant Ink

[0066] Nanofiller pretreatment: Using unmodified montmorillonite, the ball milling time is reduced to 1 hour.

[0067] Preparation of flame retardant base material: Ammonium polyphosphate and melamine polyphosphate are mixed in a ratio of 2:1, the solid-liquid ratio of deionized water is changed to 1:2, and the stirring speed is 250 rpm.

[0068] Dynamic enhancement component addition: PDMS addition amount reduced to 5%, stirring speed changed to 400 rpm.

[0069] Addition of color paste and additives: Add undispersed phthalocyanine blue paste (particle size 800nm), dispersant and film-forming aid are added in proportion, but ultrasonic dispersion is not performed.

[0070] Filtration and degassing: The filter membrane pore size was adjusted to 0.5μm, and the vacuum degassing process was omitted.

[0071] Comparative Example 3: Ink prepared using an unoptimized process

[0072] Nanofiller pretreatment: Modified montmorillonite and nano-silicate were directly mixed without ball milling.

[0073] Preparation of flame retardant base material: The mixing ratio of APP and MPA was changed to 1:1, the stirring speed was reduced to 200 rpm, and the time was shortened to 10 minutes.

[0074] Dynamic enhancement component addition: PDMS addition is 2%, BN flakes are not added.

[0075] Color paste and additives: The color paste used is iron oxide with a particle size of 1µm. The proportions of dispersant and film-forming aid are halved. Ultrasonic dispersion was not performed.

[0076] Filtration and degassing: The filter membrane pore size was adjusted to 1µm, and no degassing treatment was performed.

[0077] The following experimental setup, based on the aforementioned embodiments and comparative examples, combined with practical application scenarios, included test experiments covering flame retardant performance, color performance, ink compatibility, and overall stability.

[0078] Experiment 1: Detailed Experimental Instructions for Flame Retardant Performance Testing

[0079] Experimental objective:

[0080] The flame retardant properties of inks from different embodiments and comparative examples were verified, and the density and flame retardant effect of char layer formation were evaluated by UL-94 vertical burning test.

[0081] Experimental materials:

[0082] Coated substrate: 3mm thick polycarbonate sheet (PC sheet).

[0083] Test samples: Flame-retardant inkjet inks prepared in Examples 1 and 3, and Comparative Examples 1 and 3.

[0084] Tools and equipment: UL-94 vertical burning tester, electronic balance (accuracy 0.01g).

[0085] Experimental steps:

[0086] Preparation of coated samples:

[0087] The inks from different embodiments and comparative examples were uniformly coated onto the surface of a PC board, and the coating thickness was controlled to be 50 μm.

[0088] Allow to air dry naturally at room temperature for 24 hours.

[0089] Combustion test:

[0090] The coated sample is fixed onto the fixture of the UL-94 vertical flammability tester.

[0091] Ignite the bottom of the sample with a flame of the specified size for 10 seconds.

[0092] After removing the flame, observe and record: the self-extinguishing time of the sample; the thickness of the residual char layer; and the flame spread height. Char layer residue determination:

[0093] The burned sample was weighed using an electronic balance, and the percentage of residual char was calculated (residual char mass / initial sample mass × 100%). The cracks and integrity of the char layer were visually inspected and recorded.

[0094] Experimental replication:

[0095] Each group of samples was tested 5 times, and the average value was taken as the final data.

[0096] Experimental data table:

[0097]

[0098] Experiment Summary

[0099] The density of the char layer is clearly one of the core advantages of this invention, especially with the synergistic effect of the dynamically reinforcing components, which significantly improves the residual mass of the char layer. In Examples 1 and 3, the initial molding efficiency of the char layer is significantly improved through the dynamic release of ammonium polyphosphate (APP) and PDMS. In contrast, the crack density of the char layer in Comparative Examples 1 and 3 is higher, and the residual char mass is lower. It can be seen that the lack of a dynamic ceramization pathway will cause the oxidation resistance of the char layer to decrease rapidly, making it difficult to guarantee the flame retardant effect.

[0100] Regarding the comparison of flame propagation height, the flame height of Example 3 was only 9 mm, a reduction of nearly 60% compared to Comparative Example 3. This is not due to the effect of a single material, but rather the result of the synergistic effect of multiple components. The SiO2 released by the nano-silicate during the medium-to-high temperature stage clearly participated in crack filling and simultaneously formed a stable barrier layer. This enhancing effect was even more pronounced for the gas-phase and condensed-phase flame-retardant reactions at high temperatures. The integrity of the char layer remained stable even after multiple tests, indicating that the design of the dynamic char layer achieved good optimization.

[0101] The difference in self-extinguishing time fully demonstrates the importance of the multi-scale synergistic mechanism. The self-extinguishing time of Example 1 was only 2.1 seconds, while that of Comparative Example 1 reached 4.7 seconds, a difference of nearly double. This is largely because the dynamic reinforcing component failed to effectively stimulate the cross-linking reaction of the char layer. In contrast, the cross-action between siloxane and melamine polyphosphate was particularly crucial in the examples. The high-strength network formed by cross-linking clearly improved the physical strength of the char layer and enhanced its crack resistance, a characteristic directly reflected in the improved flame retardant rating during testing.

[0102] Experiment 2: Compatibility Test of Color Performance and Flame Retardant Performance

[0103] Experimental Objective

[0104] The performance of the colorant in the flame-retardant inkjet ink of this invention was tested, including color saturation and flame-retardant properties of the coating, and the compatibility of the colorant and flame-retardant components was verified.

[0105] Experimental materials

[0106] Coating substrate: White smooth PVC board (100×100mm).

[0107] Test samples: inks prepared in Examples 2 and 3, and Comparative Examples 2 and 3.

[0108] Tools and equipment: Spectrophotometer (colorimetric device), UL-94 vertical flammability tester.

[0109] Experimental steps

[0110] Color coating preparation

[0111] Each sample was coated onto the surface of a PVC board, with the ink coating thickness controlled at 40 μm.

[0112] Let it stand naturally to dry for 12 hours at 25℃ and 50% relative humidity.

[0113] Color performance test

[0114] The CIE-Lab* values ​​(reflecting brightness, hue, and saturation in the color space) of the coated samples were measured using a spectrophotometer.

[0115] Compare the color difference value ΔE of each sample with the standard color chart, and record the saturation.

[0116] Flame retardant performance test

[0117] According to the UL-94 vertical burning test, the PVC board coating sample was fixed in the tester fixture.

[0118] Ignite the flame in 10 seconds and record the burning time, flame spread height, and self-extinguishing time.

[0119] Coating distribution observation

[0120] The uniformity of the pigment coating was observed under natural light.

[0121] Use a microscope to magnify and observe the particle aggregation phenomenon to determine whether the color paste and flame retardant are evenly dispersed.

[0122] Experimental repetition

[0123] Each test was repeated 3 times, and the average value was taken.

[0124] Experimental data table:

[0125]

[0126] Experiment Summary

[0127] The compatibility of color and flame retardant properties has always been a challenge in industrial applications. In this experiment, the performance of the examples was impressive. Example 2 showed a color difference value ΔE of only 3.2, almost indistinguishable from the standard color chart. Simultaneously, its saturation reached 85, exhibiting vivid and rich color. This is clearly due to the precise control of the pigment particle size, coupled with the optimized design of the dispersant, allowing the pigment particles to be uniformly suspended. In Comparative Example 2, the undispersed phthalocyanine blue formed large agglomerates, resulting in a color difference of 5.9 and a significant decrease in saturation. Insufficient dispersion rendered the color performance almost meaningless.

[0128] The data on flame retardant performance are more intuitive. Example 3 exhibits a self-extinguishing time of only 2.1 seconds, with flame spread height controlled within 9 mm. This effect is inseparable from the reinforcing effect of the dynamic char layer. The colorant not only does not interfere with the flame-retardant base material but also plays a subtle role in the densification of the char layer. Comparative Example 3 is completely different. The thermal decomposition of the colorant not only generates combustion promoters but also disrupts the decomposition pathway of the flame retardant.

[0129] Observation of the coating distribution also revealed the importance of compatibility optimization. The color paste coating in the example exhibited outstanding uniformity, with almost no particle aggregation visible under a microscope. This performance is clearly due to the effect of the dispersant. In contrast, the particles in the comparative example were relatively coarse, even showing obvious sedimentation and aggregation. This uneven distribution negatively impacted both color and flame retardant properties. Compatibility optimization is crucial. It not only ensures vibrant and long-lasting colors but also significantly improves flame retardant performance.

[0130] Experiment 3: Carbon Layer Structure and Compactness Test

[0131] Experimental Objective

[0132] The effectiveness of the dynamic carbon layer reinforcement technology in this invention was evaluated through high-temperature carbonization experiments and carbon layer mechanical property tests, and the performance advantages of the carbon layer in terms of crack number, density and compressive strength were verified.

[0133] Experimental materials

[0134] Coating substrate: 50×50×2mm stainless steel sheet.

[0135] Test samples: Flame-retardant inks from Examples 1 and 3, and Comparative Examples 1 and 3.

[0136] Equipment: High-temperature furnace, scanning electron microscope (SEM, 1000×), nanoindenter (for measuring compressive strength).

[0137] Experimental steps

[0138] Sample preparation: Different ink samples were uniformly coated onto the surface of a stainless steel sheet, with the coating thickness controlled at 50 μm. The samples were then allowed to dry at room temperature for 24 hours to ensure the coating was stable and fully adhered to the substrate.

[0139] High-temperature treatment: Place the dried sample into a high-temperature furnace and heat it to 600°C at a heating rate of 10°C / min, and hold it at that temperature for 10 minutes.

[0140] The sample was removed from the furnace and cooled to room temperature before the carbon layer formed by the carbonization of the coating was observed.

[0141] Microstructure analysis:

[0142] The number, length, and distribution of microcracks in the carbon layer were observed using SEM.

[0143] The focus is on whether the cracks are concentrated, whether the propagation path is uniform, and the overall surface density of the carbon layer.

[0144] Compressive strength test

[0145] The compressive strength of the carbon layer was determined using a nanoindenter.

[0146] Three test points were selected on the surface of the carbon layer for measurement. The compressive strength value of each point was recorded and the average value was calculated.

[0147] Experimental repetition

[0148] Each sample group was tested three times to ensure the accuracy and repeatability of the results.

[0149] Experimental data table:

[0150]

[0151] Experiment Summary

[0152] The comparison of crack number and length has revealed the importance of the dynamic enhancement mechanism. In Example 1, the carbon layer had only 14 cracks, while in Comparative Example 1, the number reached 27, almost double. The formation process of the dynamic carbon layer depends on a synergistic reaction, especially the combined release of ammonium polyphosphate and siloxane. At high temperatures, nanosilicates and boron nitride flakes effectively filled the cracks in the initial stage of crack formation, preventing further crack propagation. This behavior is not a single reaction but a synergistic result of the components. The comparative sample not only had a large number of cracks but also complex paths, clearly failing to form an effective inhibition mechanism.

[0153] The difference in compressive strength is even more significant. Example 3 achieved a compressive strength of 45.8 MPa, more than twice that of Comparative Example 1. During the high-temperature carbonization process, the decomposition products of the dynamic reinforcing components formed a cross-linked network with the carbon layer, giving it superior mechanical properties. In particular, the addition of rare earth oxides significantly improved the compressive strength of the carbon layer. Comparative Example 1, lacking this reinforcing mechanism, suffered a significant reduction in the mechanical properties of its carbon layer. This strength difference is not accidental, but a direct reflection of the differences in the high-temperature reaction pathway design.

[0154] The density score of the char layer fully demonstrates the advantages of dynamic synergy. The char layer score of the example is close to 9, while that of the comparative example is only between 4 and 6. In the later stages at high temperature, the nanoparticles in the example filled the micropores through a ceramicization reaction, making the char layer surface more complete. This difference in density is not just a superficial issue, but also directly affects the persistence of flame retardant performance. The denser the char layer, the more difficult it is for oxygen to penetrate, and the slower the spread of combustion. In the comparative example, due to the propagation of cracks and the accumulation of defects, the char layer rapidly ruptured at high temperature, failing to form an effective protective barrier. This weakening of the structure rendered the final performance of the comparative example almost unusable for industrial applications.

[0155] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-performance flame-retardant inkjet ink, wherein the high-performance flame-retardant inkjet ink comprises the following components in weight percentage: ammonium polyphosphate: 20%–35%; organosiloxane: 8%–15%; melamine polyphosphate: 10%–20%; modified montmorillonite: 5%–10%; nano-silicate: 2%–8%; boron nitride flakes: 1%–5%; rare earth oxides: 0.5%–2%; color paste: 2%–10%; Dispersant: 1%–3%; Film-forming aid: 1%–3%; Viscosity modifier: 2%–6%; Deionized water: 25%–35%; the method includes the following steps: S1. Modified montmorillonite and nano-silicate are mixed to obtain nano-composite particles; step S1 includes mixing modified montmorillonite and nano-silicate in a ratio of 2:1 to 5:1 and treating them in a ball mill at a speed of 100 to 300 rpm for 2 to 4 hours. S2. Mix ammonium polyphosphate and melamine polyphosphate, add deionized water and stir to form a flame-retardant base slurry; S3. Add polydimethylsiloxane emulsion, boron nitride flakes, modified montmorillonite, nano silicate, color paste, polyvinylpyrrolidone, ethylene glycol monobutyl ether, polyethylene glycol, cerium oxide, and deionized water to the flame retardant base slurry in sequence, and stir until uniform. S4. Perform ultrasonic dispersion treatment on the mixture; S5. The ink is obtained by sequentially passing through filtration and vacuum degassing processes. The filter membrane used in step S5 has a pore size of 0.2 μm, the vacuum degree of the vacuum degassing process is -0.08 to -0.1 MPa, and the time is 15 to 30 minutes.

2. The method for preparing high-performance flame-retardant inkjet ink according to claim 1, characterized in that, In step S4, the ultrasonic dispersion treatment time is 15-30 minutes and the temperature is 25-40℃.

3. The method for preparing high-performance flame-retardant inkjet ink according to claim 1, characterized in that, The thermal decomposition temperature of the pigment is ≥400℃.

4. The method for preparing high-performance flame-retardant inkjet ink according to claim 1, characterized in that, The modified montmorillonite is modified with a silane coupling agent, and the amount of silane coupling agent is 0.5% to 2% of the mass of the modified montmorillonite.

5. The method for preparing high-performance flame-retardant inkjet ink according to claim 1, characterized in that, The rare earth oxide is cerium oxide.

6. The method for preparing high-performance flame-retardant inkjet ink according to claim 1, characterized in that, The dispersant is polyvinylpyrrolidone.

7. The method for preparing high-performance flame-retardant inkjet ink according to claim 1, characterized in that, The film-forming aid is ethylene glycol monobutyl ether, and the viscosity modifier is polyethylene glycol.

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