Aluminum hydroxide composite flame retardant for water-based cable fire-retardant coating and preparation method thereof

Abstract

The application discloses a preparation method of an aluminum hydroxide composite flame retardant for water-based cable fireproof paint. First, phytic acid is uniformly dispersed in water for dilution; then, a silica sol aqueous solution is added into the phytic acid dispersion liquid, and stirring and mixing are uniformly performed to obtain a dispersion system; then, the dispersion system is neutralized to be neutral by a weak base; then, aluminum hydroxide is added; then, grinding balls are added for grinding and dispersion; then, the filter residue is collected after filtration, and is dried and then crushed and ground again to obtain the phytic acid and silica sol modified aluminum hydroxide composite flame retardant. The composite flame retardant provided by the application is based on the phytic acid modified silica sol and coats aluminum hydroxide particles, improves the dispersibility of the aluminum hydroxide in the water-based system while retaining the complete structure of the aluminum hydroxide, fully plays the synergistic mechanism of P\Si\Al, produces a segmented flame retardant effect, effectively prolongs the carbon layer expansion and reduces the substrate temperature rising rate. The preparation process of the application is simple, and the composite flame retardant has the characteristics of low cost and stable quality.

Description

Technical Field

[0001] The present invention belongs to the field of cable fire retardant coatings, relates to the additive technology of cable fire retardant coatings, and specifically relates to an aluminum hydroxide composite flame retardant for water-based cable fire retardant coatings and a preparation method thereof. Background Art

[0002] Power cables are an indispensable component of electrical engineering, their primary function being to transmit and distribute electrical energy. With the rapid development of China's economy and the push toward urban informatization and modernization, the demand for power cables continues to increase, making their safe operation particularly crucial. Power cables are flammable and often connected in series. Therefore, cable design requires the use of materials with excellent fire resistance, flame retardancy, and thermal insulation properties, along with appropriate fire-resistant structural design, to ensure the proper operation of electrical systems. Intumescent fire retardant coatings, due to their excellent fire resistance and excellent processability, have gained widespread application in cable protection.

[0003] Conventional intumescent fire-retardant coatings are usually based on acrylic resin or epoxy resin and are combined with an NPC ternary flame retardant system. Among them, ammonium polyphosphate is used as a dehydration carbonization catalyst, pentaerythritol or dipentaerythritol is used as a carbonizing agent, and melamine is used as a foaming agent. When exposed to fire or high temperatures, these components work synergistically to form a heat-insulating carbonized layer, slowing down the heating rate of the substrate in a fire environment. Aluminum hydroxide (ATH), a commonly used metal oxide halogen-free flame retardant additive, can decompose and release water vapor when heated. At high temperatures, it can react with ammonium polyphosphate to release non-flammable ammonia, absorb a large amount of heat, thereby reducing the surface temperature of the material, and forming a heat-insulating layer. It has three major functions: flame retardancy, smoke suppression, and filling, and is widely used in various fire-retardant coatings.

[0004] However, in water-based coating systems, because each aluminum ion in aluminum hydroxide's structure is surrounded by six hydroxide ions, interconnected by hydrogen bonds, aluminum hydroxide can adsorb anions or small particles in the aqueous solution due to intermolecular van der Waals forces, forming floccules. Water-based fire-retardant coating systems inherently contain a large amount of pigments and fillers, primarily using water as a diluent. Therefore, the use of untreated aluminum hydroxide in water-based coatings may negatively impact the coating's storage stability and other film properties.

[0005] Phytic acid is a common bio-based phosphorus-containing flame retardant with a phosphorus content of 28%. It is the primary source of phosphorus in plant tissues and is primarily found in plant roots, stems, and leaves. As a recyclable natural resource, the acid produced by pyrolysis of phytic acid can promote the rapid dehydration and carbonization of oxygen-containing polymer materials, forming a dense char layer that effectively isolates the release of oxygen, heat, and volatile combustible gases. However, when used alone as a flame retardant, phytic acid has low flame retardant efficiency. Because it is an acidic substance, it is generally not suitable for direct use in conventional water-based acrylic emulsion systems. Summary of the Invention

[0006] To solve the above problems, the present invention provides an aluminum hydroxide composite flame retardant for water-based cable fire retardant coatings and a preparation method. The aluminum hydroxide composite flame retardant is obtained by using phytic acid and silica sol to modify aluminum hydroxide. When used as a flame retardant for water-based cable fire retardant coatings, a good flame retardant effect is achieved.

[0007] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0008] In one aspect, the present invention provides a method for preparing an aluminum hydroxide composite flame retardant for a water-based cable fire retardant coating, comprising the following steps:

[0009] S100, evenly dispersing phytic acid (PA) in water for dilution;

[0010] S200, adding the silica sol aqueous solution to the phytic acid dispersion, stirring and mixing uniformly to obtain a dispersion system;

[0011] S300, use weak base to neutralize the dispersion system to neutrality;

[0012] S400, adding aluminum hydroxide (ATH);

[0013] S500, adding grinding balls for grinding and dispersion;

[0014] S600, after filtering, collecting the filter residue, drying, and then crushing and grinding again to obtain a phytic acid-synergistic silica sol-modified aluminum hydroxide composite flame retardant, which is recorded as PA-Si@ATH composite flame retardant.

[0015] Furthermore, in step S100, the concentration of phytic acid dispersed in water is 0.1-1 g / ml. Using an appropriate concentration of phytic acid can achieve a good balance between flame retardant yield and product quality.

[0016] Furthermore, in step S200, the mass concentration of the silica sol aqueous solution is 25-35%. Within this range, the silica sol aqueous solution can provide a better modification effect.

[0017] Furthermore, in the dispersed system, the mass ratio of phytic acid to silica sol is 0.5:1-1:0.5. The appropriate mass ratio makes it easier to form a hydrophobic silica film.

[0018] Furthermore, the dispersion system is formed by stirring at room temperature for 1-4 hours, which is sufficient time to make the dispersion system uniform without causing the preparation time to be too long.

[0019] Furthermore, the weak base is ammonia water, low-concentration sodium hydroxide, or potassium hydroxide, with ammonia water being the best, which can adjust the pH value and provide nitrogen elements to promote expansion and flame retardancy.

[0020] Furthermore, the mass ratio of the aluminum hydroxide and phytic acid added is 1-7:1, and the appropriate ratio is conducive to forming a better isolation effect, so that the fireproof function of the aluminum hydroxide can be fully exerted.

[0021] Furthermore, in step S500, the grinding balls are zirconium beads, and the fineness after grinding is no more than 20 microns.

[0022] Furthermore, the particle size of the zirconium beads is 1-2 mm.

[0023] Furthermore, in step S600, the filter residue is collected by centrifugal filtration and rinsed with clean water multiple times after collection.

[0024] Furthermore, in step S600, the powdered aluminum hydroxide composite flame retardant is obtained by crushing and grinding again and then passing through a 300-mesh sieve.

[0025] On the other hand, the present invention provides an aluminum hydroxide composite flame retardant for water-based cable fire retardant coating, which is prepared using the above-mentioned preparation method.

[0026] The flame retardant mechanism of the aluminum hydroxide composite flame retardant of the present invention when used in water-based cable fire retardant coatings is as follows:

[0027] Silica sol is a dispersion of nano-scale silica particles dispersed in a solvent. When burning, silica can crack the carbon layer and improve the oxidation resistance of the carbon layer, which has a certain flame retardant effect. Under suitable conditions, a hydrophobic silica film can be formed on the surface of aluminum hydroxide through the sol-gel method, cutting off the adsorption and flocculation mechanism produced by the hydrolysis and ionization of aluminum ions, while retaining the complete structure of aluminum hydroxide. Pure silica coating is not conducive to dispersion. Furthermore, phytic acid and silica sol are grafted and bonded through silicon hydroxyl groups and hydrogen ions to form hydrophilic organic molecular segments, which can promote uniform dispersion in water and enhance compatibility with the system, such as Figure 5Based on the above method, a PA-Si@ATH composite flame retardant was prepared. Finally, the PA-Si@ATH composite flame retardant was added to a water-based cable fire retardant coating system to prepare a fire retardant coating with excellent fire and smoke suppression properties.

[0028] When the PA-Si@ATH-based composite flame retardant material of the present invention is mixed with the NPC ternary expansion flame retardant system to configure an intumescent fire retardant coating, the coating of the intumescent fire retardant coating is decomposed by heat to generate an acidic substance, polyphosphoric acid, when it encounters fire or high temperature. Subsequently, polyphosphoric acid and a polyol compound (pentaerythritol or dipentaerythritol) undergo an esterification reaction, and the product is dehydrated into carbon to form a carbon layer, at which time the base resin melts. The water vapor, ammonia, etc. produced by the esterification reaction and the incombustible gas produced by melamine are filled into the carbon layer, causing the system to expand and foam, forming a porous foam carbon layer. However, the expanded carbon layer formed at this time has a loose structure and low strength, and is prone to loosening and falling off. The PA-Si@ATH-based composite flame retardant material of the present invention can produce a segmented flame retardant effect, effectively helping to extend the system carbon layer expansion time and strength and reduce the substrate heating rate, and has the effects of catalyzing the reaction of the flame retardant system, increasing the amount of carbonization, and improving the quality of the carbon layer. At the beginning of combustion, the phytic acid in the outermost layer works synergistically with ammonium polyphosphate, and the radicals decompose to produce some phosphorus-containing free radicals, such as HPO•, PO• and HPO2•, which can capture the active HO• and H• produced during the combustion of the polymer material, extinguish the combustion chain reaction, thereby reducing the flammability of the substrate and promoting the rapid dehydration and carbonization of the water-based acrylic polymer; afterward, the silica in the outer shell of the flame retardant material participates in the catalytic carbonization reaction of pentaerythritol to generate an inorganic oxygen-isolating and heat-insulating protective layer and an expanded carbon layer with Si-O bonds and (or) Si-C bonds, thereby improving the physical barrier effect; finally, the aluminum hydroxide in the inner core further dilutes the oxygen concentration with water vapor released at high temperature, delaying the thermal decomposition of the polymer material, and reacts with the remaining ammonium polyphosphate at high temperature to generate aluminum phosphate, forming a protective layer, which further improves the strength of the carbon layer and the residual carbon rate.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) It has high flame retardant and smoke suppression efficiency. Through the synergistic effect of phytic acid, silica and aluminum hydroxide, it can produce a segmented flame retardant effect, effectively helping to prolong the expansion time and strength of the system carbon layer and reduce the heating rate of the substrate. It has the functions of catalyzing the reaction of the flame retardant system, increasing the amount of carbonization, and improving the quality of the carbon layer.

[0031] (2) Phytic acid modified silica sol coated aluminum hydroxide not only retains the complete structure of aluminum hydroxide, but also promotes its more uniform dispersion in the coating system, improves the compatibility and improves the overall performance of the coating.

[0032] (3) The preparation process is simple. PA-Si@ATH composite flame retardant can be obtained through mild reaction and preparation process, and fire retardant coating can be further prepared through reasonable process optimization, which has the characteristics of low cost and stable quality.

[0033] (4) Halogen-free and environmentally friendly, PA-Si@ATH composite flame retardant is halogen-free, non-toxic and highly efficient. It has great practical significance for the development of the environmental protection industry and the widespread use of green flame retardants, and adapts to the trend of halogen-free flame retardants. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The figure is a schematic diagram of the process for preparing the aluminum hydroxide composite flame retardant according to the present invention.

[0035] Figure 2a is the XRD pattern of aluminum hydroxide;

[0036] Figure 2b is the XRD pattern of the phytic acid-silica sol mixture;

[0037] Figure 2c This is the XRD pattern of the modified aluminum hydroxide composite flame retardant.

[0038] Figure 3 The SEM morphology of aluminum hydroxide before and after modification, among which, Figure 3 (a) is the SEM morphology of aluminum hydroxide before modification. Figure 3 (b) is the SEM image of the modified aluminum hydroxide, namely PA-Si@ATH.

[0039] Figure 4 is the EDS element spectrum before and after aluminum hydroxide modification, among which, Figure 4 (a) is the EDS element map of aluminum hydroxide before modification. Figure 4 (b) is the EDS elemental map of the modified aluminum hydroxide, namely PA-Si@ATH.

[0040] Figure 5 Schematic diagram of the flame retardant expansion of the cable fire retardant coating after combustion in Test Example 1.

[0041] Figure 6 Schematic diagram of the principle of grafting bonding between phytic acid and silica sol on the surface of aluminum hydroxide through silanol and hydrogen ions. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not intended to limit the present invention. Any simple improvements to the preparation method of the present invention based on the concept of the present invention are within the scope of protection of the present invention.

[0043] Example 1

[0044] A method for preparing an aluminum hydroxide composite flame retardant for a water-based cable fire retardant coating comprises the following steps:

[0045] 10g of phytic acid (PA) was evenly dispersed in 20ml of water for dilution. Then, 30g of a 30% silica sol aqueous solution was added dropwise to the PA dispersion and stirred at room temperature for 2h. The phytic acid was neutralized with ammonia water to make the pH of the system neutral. Then, 40g of ATH powder was added, and an equal volume of zirconium beads with a particle size of 1-2mm were added for grinding and dispersion to a fineness of less than 20 microns. The upper suspension was centrifuged and rinsed with clean water several times, filtered and dried, and then crushed and ground. The mixture was passed through a 300 sieve to obtain a phytic acid-silica sol-modified aluminum hydroxide composite flame retardant, labeled PA-Si@ATH.

[0046] Qualitative analysis of XRD test on samples before and after aluminum hydroxide modification, the results are as follows Figure 2a-2c As shown: Figure 2a is the XRD pattern of unmodified aluminum hydroxide, Figure 2b is the XRD pattern of phytic acid-silica sol mixture, Figure 2c This is the XRD pattern of the modified aluminum hydroxide composite flame retardant. Figure 2a The middle diffraction peak is sharp and the phase is clear, indicating that the aluminum hydroxide has good crystallinity and high purity. Figure 2a Since silica has an amorphous structure, the X-ray diffraction pattern of this type of non-crystalline structure has many burrs, and the characteristic peak of amorphous silica is around 23°. Figure 2c In the diffraction spectrum, a long and sharp diffraction peak can be observed, which corresponds to aluminum hydroxide, while the overall amorphous peak spectrum area is large and the characteristics are more obvious, indicating that there is a large amount of silicon dioxide on the surface of aluminum hydroxide. Further SEM morphology analysis of aluminum hydroxide before and after modification is performed, as shown in the following figure: Figure 3 As shown, Figure 3 (a) is the SEM image of aluminum hydroxide before modification. Figure 3 (b) is the SEM image of the modified aluminum hydroxide, namely PA-Si@ATH; Figure 3 It can be seen that the original aluminum hydroxide surface is relatively smooth and evenly distributed. After treatment and modification, the surface edges of aluminum hydroxide are no longer prominent. EDS elemental spectrum measurement of aluminum hydroxide before and after modification is carried out. The results are as follows Figure 4 As shown, Figure 4 (a) is the EDS element map of aluminum hydroxide before modification. Figure 4(b) shows the EDS elemental map of the modified aluminum hydroxide, PA-Si@ATH. A surface scan of the original aluminum hydroxide reveals that it is primarily composed of Al and O, indicating high purity. After modification, Si and P elements are added to its surface, indicating that the phytic acid-modified silica sol has coated the aluminum hydroxide surface. Combined XRD, SEM, and EDS analysis in Figures 2-3 demonstrates that the phytic acid-modified silica sol has successfully coated the aluminum hydroxide particles.

[0047] Example 2

[0048] A method for preparing an aluminum hydroxide composite flame retardant for a water-based cable fire retardant coating comprises the following steps:

[0049] 10g of phytic acid (PA) was evenly dispersed in 20ml of water for dilution. Then, 30g of a 30% silica sol aqueous solution was added dropwise to the PA dispersion and stirred at room temperature for 2h. The phytic acid was neutralized with ammonia water to make the pH of the system neutral. Then, 10g of ATH powder was added, and an equal volume of zirconium beads with a particle size of 1-2mm were added for grinding and dispersion to a fineness of less than 20 microns. The upper suspension was centrifuged and rinsed with clean water several times, filtered and dried, and then crushed and ground. The mixture was passed through a 300 sieve to obtain a phytic acid-silica sol-modified aluminum hydroxide composite flame retardant, labeled PA-Si@ATH.

[0050] Example 3

[0051] A method for preparing an aluminum hydroxide composite flame retardant for a water-based cable fire retardant coating comprises the following steps:

[0052] 10g of phytic acid (PA) was evenly dispersed in 20ml of water for dilution. Then, 30g of a 30% silica sol aqueous solution was added dropwise to the PA dispersion and stirred at room temperature for 2h. The phytic acid was neutralized with ammonia water to make the pH of the system neutral. Then, 70g of ATH powder was added, and an equal volume of zirconium beads with a particle size of 1-2mm were added for grinding and dispersion to a fineness of less than 20 microns. The upper suspension was centrifuged and rinsed with clean water several times, filtered and dried, and then crushed and ground. The mixture was passed through a 300 sieve to obtain a phytic acid-silica sol-modified aluminum hydroxide composite flame retardant, labeled PA-Si@ATH.

[0053] The aluminum hydroxide composite flame retardant prepared in Example 1 was used to prepare a PA-Si@ATH based waterborne intumescent fire retardant coating and tested as follows:

[0054] Test Example 1:

[0055] iSlurry preparation:

[0056] Weigh 14.5 parts of deionized water, slowly add 0.5 parts of dispersant at a speed of 300-500 rpm and disperse for 5-8 minutes, then add 9 parts of melamine (MEL), 9 parts of pentaerythritol (PER), 20 parts of ammonium polyphosphate (APP), 8 parts of mixed pigments and fillers (titanium dioxide: talc powder mass ratio of 7:2), 4 parts of PA-Si@ATH composite flame retardant, and 1 part of ultraviolet absorber (UV-531), and adjust the speed to 2000 rpm and disperse for 10-15 minutes. During this process, the stirring shaft and the cylinder wall powder are cleaned with 1 part of propylene glycol and 2 parts of deionized water; then replace the sand mill disc, add glass beads at a weight ratio of 1:1, start the circulating water in the sand mill, continue stirring and grinding and dispersing until the system fineness is ≤60μm; after filtration, the sand mill slurry is obtained.

[0057] ii. Coating preparation:

[0058] Weigh the above-mentioned sand-grinded slurry, slowly add 28 parts of aqueous emulsion at a speed of 600-800 rpm, stir for 5-10 minutes; 1 part of 10% aqueous bentonite slurry, then add 0.3 parts of defoamer and the remaining co-solvent 2 parts of dodecyl alcohol ester, continue to disperse at 1500-2500 rpm for 10-20 minutes, after uniform dispersion, filter and package to obtain an expandable water-based cable protective coating.

[0059] Test Example 2:

[0060] iSlurry preparation:

[0061] Weigh 14.5 parts of deionized water, slowly add 0.5 parts of dispersant at a speed of 300-500 rpm and disperse for 5-8 minutes, then add 9 parts of melamine (MEL), 9 parts of pentaerythritol (PER), 20 parts of ammonium polyphosphate (APP), 8 parts of mixed pigments and fillers (titanium dioxide: talc powder mass ratio of 7:2), 1 part of PA-Si@ATH composite flame retardant, and 1 part of ultraviolet absorber (UV-531), and adjust the speed to 2000 rpm and disperse for 10-15 minutes. During this process, the stirring shaft and the cylinder wall powder are cleaned with 1 part of propylene glycol and 2 parts of deionized water; then replace the sand mill disc, add glass beads at a weight ratio of 1:1, start the circulating water in the sand mill, continue stirring and grinding and dispersing until the system fineness is ≤60μm; after filtration, the sand mill slurry is obtained.

[0062] ii. Coating preparation:

[0063] Weigh the above-mentioned sand-grinded slurry, slowly add 28 parts of aqueous emulsion at a speed of 600-800 rpm, stir for 5-10 minutes; 1 part of 10% aqueous bentonite slurry, then add 0.3 parts of defoamer and the remaining co-solvent 2 parts of dodecyl alcohol ester, continue to disperse at 1500-2500 rpm for 10-20 minutes, after uniform dispersion, filter and package to obtain an expandable water-based cable protective coating.

[0064] Comparative Example 1

[0065] iSlurry preparation:

[0066] Weigh 14.5 parts of deionized water, slowly add 0.5 parts of dispersant at a speed of 300-500 rpm and disperse for 5-8 minutes, then add 9 parts of melamine (MEL), 9 parts of pentaerythritol (PER), 20 parts of ammonium polyphosphate (APP), 8 parts of mixed pigments and fillers (titanium dioxide: talc powder mass ratio of 7:2), 4 parts of unmodified aluminum hydroxide, and 1 part of ultraviolet absorber (UV-531), and adjust the speed to 2000 rpm and disperse for 10-15 minutes. During this process, the stirring shaft and the cylinder wall powder are cleaned with 1 part of propylene glycol and 2 parts of deionized water; then replace the sand mill disc, add glass beads at a weight ratio of 1:1, start the circulating water in the sand mill, continue stirring and grinding and dispersing until the system fineness is ≤60μm; after filtration, the sand mill slurry is obtained.

[0067] ii. Coating preparation:

[0068] Weigh the above-mentioned sand-grinded slurry, slowly add 28 parts of aqueous emulsion at a speed of 600-800 rpm, stir for 5-10 minutes; 1 part of 10% aqueous bentonite slurry, then add 0.3 parts of defoamer and the remaining co-solvent 2 parts of dodecyl alcohol ester, continue to disperse at 1500-2500 rpm for 10-20 minutes, after uniform dispersion, filter and package to obtain an expandable water-based cable protective coating.

[0069] Comparative Example 2

[0070] iSlurry preparation:

[0071] Weigh 14.5 parts of deionized water, slowly add 0.5 parts of dispersant at a speed of 300-500 rpm and disperse for 5-8 minutes, then add 9 parts of melamine (MEL), 9 parts of pentaerythritol (PER), 20 parts of ammonium polyphosphate (APP), 8 parts of mixed pigments and fillers (titanium dioxide: talc powder mass ratio of 7:2), 4 parts of silica sol, and 1 part of ultraviolet absorber (UV-531), and adjust the speed to 2000 rpm and disperse for 10-15 minutes. During this process, the stirring shaft and the cylinder wall powder are cleaned with 1 part of propylene glycol and 2 parts of deionized water; then replace the sand grinding disc, add glass beads at a weight ratio of 1:1, start the circulating water in the sand grinding cylinder, continue stirring and grinding and dispersing until the system fineness is ≤60μm; after filtration, the sand grinding slurry is obtained.

[0072] ii. Coating preparation:

[0073] Weigh the above-mentioned sand-grinded slurry, slowly add 28 parts of aqueous emulsion at a speed of 600-800 rpm, stir for 5-10 minutes; 1 part of 10% aqueous bentonite slurry, then add 0.3 parts of defoamer and the remaining co-solvent 2 parts of dodecyl alcohol ester, continue to disperse at 1500-2500 rpm for 10-20 minutes, after uniform dispersion, filter and package to obtain an expandable water-based cable protective coating.

[0074] The performance of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in the following table:

[0075] Table 1 Cable fire retardant coating performance

[0076]

[0077] As shown in Table 1 above, the addition of PA-Si@ATH composite flame retardant can significantly improve the flame retardant performance, with excellent performance, fully meeting the requirements of GB / T 28374 cable fire retardant coating standard. Furthermore, combined with the XRD in Figure 2, it is shown that amorphous silica can form a coating on the surface of ATH. Figure 3 and Figure 4 The morphology of aluminum hydroxide before and after modification and the EDS element map of the surface are shown. The surface of the modified aluminum hydroxide has Si and P elements, which can play a synergistic role in the cable fire retardant coating. Through the combustion test of the PA-Si@ATH-based water-based intumescent cable fire retardant coating in Test Example 1, Figure 5 As shown, it has excellent expansion flame retardant effect, and a white aluminum-containing protective layer can be formed on its surface.

[0078] The above embodiments are intended to illustrate the present invention only and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that various combinations, modifications, or equivalent substitutions of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and should be encompassed by the scope of the claims of the present invention.

Claims

1. A method for preparing an aluminum hydroxide composite flame retardant for a water-based cable fire retardant coating, characterized in that: The following steps are involved: Evenly disperse phytic acid in water for dilution; Adding the silica sol aqueous solution to the phytic acid dispersion, stirring and mixing uniformly to obtain a dispersion system; Use a weak base to neutralize the dispersed system to neutrality; Add aluminum hydroxide; Add grinding balls for grinding and dispersion; After filtering, the filter residue is collected, dried, and then crushed and ground again to obtain a phytic acid-synergistic silica sol-modified aluminum hydroxide composite flame retardant.

2. The method for preparing the aluminum hydroxide composite flame retardant according to claim 1, wherein: The concentration of the phytic acid dispersed in water is 0.1-1 g / ml.

3. The method for preparing the aluminum hydroxide composite flame retardant according to claim 1, wherein: The mass concentration of the silica sol aqueous solution is 25-35%.

4. The method for preparing the aluminum hydroxide composite flame retardant according to claim 1, wherein: The dispersed system is formed by stirring at room temperature for 1-4 hours.

5. The method for preparing the aluminum hydroxide composite flame retardant according to claim 1, wherein: The weak base is aqueous ammonia.

6. The method for preparing the aluminum hydroxide composite flame retardant according to claim 1, wherein: The mass ratio of the aluminum hydroxide and phytic acid added is 1-7:

1.

7. The method for preparing the aluminum hydroxide composite flame retardant according to claim 1, wherein: The grinding balls are zirconium beads, and the fineness after grinding is not greater than 20 microns.

8. The method for preparing the aluminum hydroxide composite flame retardant according to claim 1, wherein: The filter residue is collected by centrifugal filtration and rinsed with clean water several times after collection.

9. An aluminum hydroxide composite flame retardant for water-based cable fire retardant coating, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

Images