Metal phthalocyanine-mof hybrid materials, methods of making and use thereof in the preparation of fireproof materials

Abstract

This invention provides a metal phthalocyanine-MOF hybrid material, its preparation method, and its application in the preparation of fire-retardant materials, belonging to the field of fire-retardant materials. The hybrid material comprises a ZIF-8 core and a tetraaminometal phthalocyanine shell. It is prepared by grafting tetraaminometal phthalocyanine onto ZIF-8 particles through an amino condensation reaction under the action of an amino condensing agent, forming a core-shell structure. This invention also provides an application of the above-mentioned hybrid material in conjunction with silicate gel-modified microspheres in the preparation of fire-retardant materials. When the hybrid material is exposed to fire, the metal oxides formed react with the silicate gel layer on the surface of the silicate gel-modified microspheres in a multi-metal ceramicization reaction. The reaction product is embedded in the char layer to improve the thermal stability and mechanical strength of the char layer, delaying char layer cracking and detachment. Simultaneously, it achieves a synergistic effect of multiple flame-retardant mechanisms, effectively enhancing the strength of the char layer formed during the flame-retardant process of organic polymer materials, delaying or preventing char layer cracking, and improving thermal insulation performance.

Description

Technical Field

[0001] This invention relates to the field of fire-retardant materials, specifically to a metal phthalocyanine-MOF hybrid material, its preparation method, and its application in the preparation of fire-retardant materials. Background Technology

[0002] With the continuous increase in the number of high-rise and super high-rise buildings and public buildings, the application of building windows, fire-resistant partition doors and windows and fire escape doors and windows is becoming more and more common. Their fire resistance performance is directly related to the safety of people's lives and property. Moreover, building doors and windows in chemical industrial parks and coastal high-corrosion areas need to meet the dual requirements of fire resistance and corrosion resistance at the same time, which is difficult to achieve with existing door and window materials. While UPVC (unplasticized polyvinyl chloride) door and window profiles offer excellent thermal insulation, sound insulation, and corrosion resistance, and are significantly cheaper than aluminum alloy and steel doors and windows, they are inherently flammable materials with an oxygen index of only about 18%-20%. When exposed to fire, they easily melt and drip, potentially causing the flames to spread. This makes it difficult to meet the fire-retardant requirements for doors and windows in high-rise buildings, fire compartments, and fire escape routes as stipulated in GB 55036-2022 "General Code for Fire Protection of Buildings". Existing fire-resistant doors and windows (such as fire-resistant thermally broken aluminum and steel fire-resistant windows) meet fire protection requirements, but they suffer from poor thermal insulation and sound insulation, weak corrosion resistance, and high raw material costs, failing to simultaneously meet the multiple demands of fire resistance, energy saving, corrosion resistance, and cost.

[0003] Currently, the main technical approaches to improve the fire resistance of UPVC profiles include adding intumescent flame retardants (such as the APP / PER / MEL system) or inorganic fillers (such as hollow glass microspheres). However, the existing technologies have the following shortcomings: (1) The traditional intumescent flame retardant system of APP / PER / MEL is prone to migration and precipitation during processing, which affects the long-term flame retardant effect; (2) The formed char layer has low strength and loose structure, and is prone to cracking and falling off when exposed to fire; (3) Although hollow glass microspheres can be used as lightweight fillers to improve processing performance and reduce density, their flame retardant effect is limited when used alone, and the compounding with flame retardants is mostly a simple physical mixing with weak interfacial bonding.

[0004] MOFs (metal-organic frameworks) have gained attention in the flame retardant field in recent years, mainly due to the synergistic effects of multiple mechanisms, including metal-catalyzed char formation, porous physical barrier, ligand endothermic release of inert gases, and free radical capture. They also possess advantages such as tunable structure, matrix compatibility, and high efficiency with low addition levels. Phthalocyanines are aromatic heterocyclic compounds with a large π-conjugated system, whose centers can coordinate to various metal ions (such as Cu). 2+ Zn 2+ Fe 2+(etc.), possessing high thermal stability and catalytic activity. Combining metal phthalocyanines with MOFs is expected to improve the flame retardant properties of UPVC through their synergistic effect, but there are no reports in the existing technology on how to combine the two and synergistically enhance flame retardant properties. Summary of the Invention

[0005] ZIF-8 (zeolite imidazole ester framework material-8) belongs to MOFs. Upon heating, it decomposes to release non-combustible gases and generate ZnO, catalyzing char formation, thus exhibiting both gas-phase and condensed-phase flame-retardant mechanisms. Therefore, one of the main objectives of this invention is to provide a metal phthalocyanine-MOF hybrid material by chemically grafting ZIF-8 with metal phthalocyanine. This hybrid material possesses stable interfacial bonding, which is beneficial for its uniform dispersion and synergistic effect in flame-retardant applications.

[0006] Specifically, a metal phthalocyanine-MOF hybrid material has a core-shell structure, comprising ZIF-8 as the core and tetraaminometal phthalocyanine as the shell.

[0007] Furthermore, the hybrid material is prepared by grafting tetraaminometal phthalocyanine onto ZIF-8 particles through an amino condensation reaction under the action of an amino condensing agent to form a core-shell structure. The amino condensing agent used in this invention includes N,N'-dicyclohexylcarbodiimide (DCC) or 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl).

[0008] A second objective of this invention is to enhance the interfacial bonding strength between ZIF and tetraaminometal phthalocyanine, which is beneficial for the uniform dispersion of the flame-retardant component in the matrix and the exertion of its synergistic effect. To achieve this objective, this invention provides a method for preparing the above-mentioned metal phthalocyanine-MOF hybrid material, comprising the following steps: Amination of ZIF-8: ZIF-8 nanoparticles were amination-treated to obtain ZIF-8-NH2 particles. Amino condensation grafting reaction: Under the action of an amino condensing agent, the ZIF-8-NH2 particles and tetraaminometal phthalocyanine undergo an amino condensation reaction to graft the tetraaminometal phthalocyanine onto the ZIF-8 nanoparticles, forming a core-shell structure.

[0009] In one specific embodiment, the amination step of ZIF-8 includes: first dispersing the ZIF-8 nanoparticles in an amino compound, and then heating and reacting at 90-150°C for 12-48 hours to obtain the ZIF-8-NH2 particles; wherein the solid-liquid ratio of the ZIF-8 nanoparticles to the amino compound is (5-12) g : (80-200) mL. The amino compound is selected from at least one of ethylenediamine, 3-aminopropyltriethoxysilane, 3-amino-1,2,4-triazole, and polyethyleneimine.

[0010] In one specific embodiment, the amino condensation grafting reaction step includes: dispersing the ZIF-8-NH2 and the tetraamino metal phthalocyanine in N,N-dimethylformamide (DMF) at a mass ratio of 3-5:1, adding the amino condensing agent, and reacting at 80-120°C for 8-16 hours to obtain the metal phthalocyanine-MOF hybrid material.

[0011] A third objective of this invention is to provide an application of the aforementioned metal phthalocyanine-MOF hybrid material combined with silicate gel-modified microspheres in the preparation of fire-retardant materials. Specifically, the silicate gel-modified microspheres of this invention consist of hollow glass microspheres and a silicate gel layer coating the surface of the hollow glass microspheres.

[0012] Furthermore, the silicate gel-modified microbeads are mainly prepared by the following methods: Activated microspheres: Hollow glass microspheres are treated with oxygen plasma to activate the surface of the hollow glass microspheres and introduce hydroxyl functional groups to obtain hydroxyl-modified microspheres. Sodium silicate-coated microspheres: Hydroxyl-modified microspheres are added to an aqueous solution of sodium silicate to carry out a surface coating reaction, so that sodium silicate is uniformly coated on the surface of the microspheres, forming a secondary modification system of microspheres; Gel-modified microbeads: The pH of the secondary modification system of the microbeads is adjusted to 6.5-7.0 to hydrolyze and condense sodium silicate to form a silicate gel layer, which is then dried to obtain the silicate gel-modified microbeads.

[0013] The fourth objective of this invention is to provide a composite flame retardant comprising a uniformly mixed metal phthalocyanine-MOF hybrid material and silicate gel-modified microspheres, wherein the mass ratio of the two is 12-22 : 8-15. Thus, through the compounding of ZIF-8@metal phthalocyanine and silicate gel-modified microspheres, a synergistic effect of multiple flame retardant mechanisms is achieved, including gas-phase flame retardancy, condensed-phase flame retardancy, ceramic reinforcement, and graphitized reinforcing agent thermal barrier.

[0014] The fifth objective of this invention is to provide an application of the above-mentioned metal phthalocyanine-MOF hybrid material or the above-mentioned composite flame retardant in the preparation of fire-retardant materials, wherein the matrix material of the fire-retardant material is an organic polymer material.

[0015] The sixth objective of this invention is to provide a flame-retardant modified UPVC composite material, mainly composed of the following raw materials in parts by weight: 100 parts of PVC resin with a degree of polymerization of 1000-1200, 12-22 parts of the aforementioned metal phthalocyanine-MOF hybrid material, 8-15 parts of the aforementioned silicate gel-modified microspheres, 3-5 parts of calcium-zinc stabilizer, 2-4 parts of acrylate processing aid (ACR), 5-8 parts of resin-type chlorinated polyethylene (CPE), 4-6 parts of titanium dioxide, 0.5-1.5 parts of calcium stearate, and 0.3-0.8 parts of polyethylene wax. The flame-retardant modified UPVC composite material has an oxygen index ≥35%, a vertical burning rating of V-0, a smoke density rating SDR ≤42, and a back-fire surface temperature rise rate ≤16℃ / min. Furthermore, the composite char layer formed after the composite material is exposed to fire remains intact and crack-free after being burned at 500℃ for 15 minutes. Preferably, the metal phthalocyanine-MOF hybrid material consists of particles of 200-600 nm.

[0016] The seventh objective of this invention is to provide a method for preparing the above-mentioned flame-retardant modified UPVC composite material, comprising: firstly, stirring and mixing the PVC resin, calcium-zinc stabilizer, acrylate processing aid, resin-type chlorinated polyethylene, titanium dioxide, calcium stearate, and polyethylene wax to form a matrix raw material premix; then adding the above-mentioned metal phthalocyanine-MOF hybrid material and silicate gel modified microspheres and mixing them uniformly to form a UPVC fire-retardant raw material mixture; and performing melt blending extrusion treatment on the UPVC fire-retardant raw material mixture to obtain the flame-retardant modified UPVC composite material.

[0017] To further ensure uniform dispersion of each component without damaging the material structure, the method for forming the UPVC fire-retardant raw material mixture includes: mixing the metal phthalocyanine-MOF hybrid material, silicate gel modified microspheres, and matrix raw material premix at 100-110°C for 8-10 minutes at a stirring speed of 800-1200 r / min.

[0018] Furthermore, the melt blending extrusion process includes: adding the UPVC fire-retardant raw material mixture into a parallel twin-screw extruder for melt blending extrusion, wherein the temperature of the parallel twin-screw extruder is set as follows: Zone 1 160-165℃, Zone 2 165-170℃, Zone 3 170-175℃, Zone 4 170-175℃, and Die Head 165-170℃, and the screw speed is 150-200 r / min, to obtain the flame-retardant modified UPVC composite material.

[0019] The eighth objective of this invention is to provide an application of the above-mentioned flame-retardant modified UPVC composite material in the preparation of door and window profiles, flame-retardant building pipes, interior decorative wall panels, wire and cable insulation sheaths, and automotive interior parts.

[0020] The ninth objective of this invention is to provide a finished UPVC fireproof door and window frame profile, made of the aforementioned flame-retardant modified UPVC composite material. This finished UPVC fireproof door and window frame profile can be used in fireproof doors and windows in high-rise buildings, public buildings, and chemical / coastal corrosive areas, filling the market gap in existing door and window materials that balance fire resistance, energy conservation, corrosion resistance, high performance, and low cost.

[0021] Therefore, in the above-mentioned technical solution provided by the present invention, a hybrid material with a core-shell structure is formed by chemically grafting ZIF-8 with metal phthalocyanine. This hybrid material works synergistically with silicate gel-modified microspheres to effectively enhance the strength of the char layer formed during the flame retardant process, delay or prevent char layer cracking, and improve thermal insulation performance. It can improve the problems of low char layer strength, easy cracking, and insufficient thermal insulation performance of existing organic fireproof materials. The prepared organic composite fireproof material has excellent fire resistance, flame retardancy, thermal insulation, sound insulation, and corrosion resistance. It can accurately meet the flame retardant requirements of high-end automotive interior parts, as well as the requirements of fireproof doors and windows, flame-retardant pipes, interior decorative wall panels, and wire and cable insulation sheaths for high-rise buildings, public buildings, and industrial buildings. It fills the market gap of existing building fireproof materials that "combine fire resistance with energy saving and corrosion prevention, and balance high performance with low cost". Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the structure of the metal phthalocyanine-MOF hybrid material provided by the present invention; Figure 2 This is a SEM image of the ZIF-8@CuTAPc hybrid material provided in Embodiment 1 of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0024] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0025] In this invention, unless otherwise specified and / or stated, all numerical values ​​involving component amounts are by weight. Unless otherwise specified, the terminology used in this invention is common in the relevant field. Unless otherwise specified, the preparation methods, plasma treatment methods, process steps, testing methods, etc., used in the various embodiments are conventional means well known to those skilled in the art, and the raw materials and equipment used are all available from publicly available commercial sources.

[0026] To further improve the flame retardant properties of organic polymer fire-retardant materials, this invention mainly utilizes the chemical grafting of tetraaminometal phthalocyanine with ZIF-8 to form a core-shell structured metal phthalocyanine-MOF hybrid material. This hybrid material, in synergy with silicate-modified hollow glass microspheres, effectively enhances the strength of the char layer formed during the flame retardant process of the organic fire-retardant material, delays or prevents char layer cracking, and improves thermal insulation performance. The specific implementation scheme of this invention is as follows: In a first aspect, the present invention provides a metal phthalocyanine-MOF hybrid material, such as Figure 1 The diagram shows a core-shell structure comprising a ZIF-8 core layer and a tetraaminometal phthalocyanine shell grafted onto the ZIF-8 core layer. The ZIF-8 core layer and the tetraaminometal phthalocyanine shell layer are connected via an amino condensation reaction. Specifically, the metal phthalocyanine-MOF hybrid material is prepared by grafting tetraaminometal phthalocyanine onto ZIF-8 via an amino condensation reaction under the action of an amino condensing agent, forming a core-shell structure. The amino condensing agent used in this invention includes N,N'-dicyclohexylcarbodiimide (DCC) or 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl). Preferably, the hybrid material consists of particles with a particle size of 200-600 nm, which can be directly used as a finished product; more preferably, the particle size of the hybrid material is 200-430 nm.

[0027] The ZIF-8 of this invention is preferably formed by coordination bonds between zinc ions and 2-methylimidazole in a molar ratio of 1:6-8; the preferred particle size is 180-350 nm. The metal ion M in the tetraaminometal phthalocyanine (MTAPc) of this invention... 2+ Cu is preferred 2+ Zn 2+ and Fe 2+ At least one of them.

[0028] Secondly, the present invention provides a method for preparing the above-mentioned MTAPC-MOF hybrid material, comprising the following steps: Amination of ZIF-8: ZIF-8 nanoparticles were amination-treated to obtain ZIF-8-NH2 particles. Amino condensation grafting reaction: Under the action of an amino condensing agent, the ZIF-8-NH2 particles and MTAPC undergo an amino condensation reaction to graft MTAPC onto the ZIF-8 nanoparticles, forming a core-shell structure.

[0029] Because MTAPC possesses a π-conjugated system, a central metal ion, multiple monocyclic heterocyclic structures, and tetraamino functional groups, its π-conjugated system can be graphitized at high temperatures to form a dense carbon layer; the central metal ion, such as Cu... 2+ Zn 2+ and Fe 2+ When heated, these components can generate a metal oxide ceramic phase, enhancing the strength of the char layer. The multiple mono- and mono-heterocyclic structures within them can release non-flammable gases such as N2 and NH3 upon heating. Due to the large spatial size of MTAPC molecules, they cannot diffuse into the ZIF-8 channels. They can only undergo a condensation grafting reaction with the exposed -NH2 on the outer surface of ZIF-8-NH2 under the action of an amino condensing agent. The phthalocyanine component can only gradually bond and accumulate on the outer side of the ZIF-8 grains, unable to penetrate into the interior due to spatial obstruction. Therefore, the tetraamino functional groups in MTAPC react with the amino groups in ZIF-8-NH2 to form a core-shell structure, and the MTAPC component firmly adheres to the outer layer of the ZIF-8 particles, forming a coated outer shell layer. Therefore, the metal phthalocyanine-MOF hybrid material prepared by the method provided in this invention has a more stable interfacial bond compared to a simple physical mixture of MTAPC and ZIF-8, which is beneficial for the uniform dispersion of the flame-retardant component in the matrix and the exertion of a synergistic effect.

[0030] In one specific embodiment, the amination step of ZIF-8 includes: first dispersing the ZIF-8 nanoparticles in an amino compound, and then heating and reacting at 90-150°C for 12-48 hours to obtain the ZIF-8-NH2 particles. The solid-liquid ratio of the ZIF-8 nanoparticles to the amino compound is (5-12) g : (80-200) mL. In this step, the nitrogen atom in the amino group (-NH2) of the amino compound carries a lone pair of electrons and has a strong coordinating ability; it can coordinate with the unsaturated Zn in the ZIF-8 framework. 2+ The active site undergoes coordination, introducing the amino group into the material surface or pores, thus achieving amino functionalization modification of ZIF-8. Therefore, the amino compound is selected from at least one of ethylenediamine, 3-aminopropyltriethoxysilane, 3-amino-1,2,4-triazole, and polyethyleneimine. Preferably, the amino compound is ethylenediamine, wherein the amino group can directly coordinate with the unsaturated Zn group in the ZIF-8 structure. 2+The active site coordinates to form a coordinate bond; it can also partially replace the organic ligand of 2-methylimidazole in the ZIF-8 skeleton. Through this ligand exchange, the amino compound is successfully grafted onto the ZIF-8 skeleton, thereby introducing free amino groups (-NH2) into the ZIF-8 surface or pores, which is beneficial to further enhance the interfacial bonding strength between ZIF and tetraamino phthalocyanine.

[0031] In one specific embodiment, the amino condensation grafting reaction step includes: dispersing the ZIF-8-NH2 particles and the MTAPc in N,N-dimethylformamide (DMF) at a mass ratio of 3-5:1, adding the amino condensing agent, and reacting at 80-120°C for 8-16 hours to obtain the metal phthalocyanine-MOF hybrid material, which can be represented as "ZIF-8@MTAPc".

[0032] In one specific embodiment, the preparation method of the ZIF-8 nanoparticles includes: using 2-methylimidazole and a soluble zinc salt as raw materials, a self-assembly reaction is carried out at room temperature, followed by washing and drying to obtain the ZIF-8 nanoparticles; wherein the molar ratio of the soluble zinc salt and 2-methylimidazole is 1:6-8. The soluble zinc salt is selected from at least one of zinc nitrate hexahydrate (Zn(NO3)2•6H2O), zinc acetate dihydrate (Zn(CH3COO)2·2H2O), zinc chloride (ZnCl2), and zinc sulfate (ZnSO4).

[0033] In one specific embodiment, the method for preparing the MTAPc includes: Synthesis of tetranitrophthalocyanine metal: 4-nitrophthalonitrile, a soluble metal salt, urea, and ammonium molybdate are mixed and ground evenly in a mass ratio of 4-6 : 1-2 : 8-12 : 0.1-0.3, and then melted and reacted at 200-250℃ for 2-4 hours to obtain tetranitrophthalocyanine metal; preferably, the soluble metal salt is selected from at least one of copper chloride CuCl2, zinc chloride ZnCl2, and ferrous chloride FeCl2.

[0034] Synthesis of tetraaminophthalocyanine metal: Tetranitrophthalocyanine metal is dissolved in an aqueous sodium sulfide solution and subjected to a nitro reduction reaction at 60-80℃ for 2-4 hours to obtain MTAPC, wherein the metal M is Cu, Zn or Fe.

[0035] Thirdly, the present invention provides an application of the above-mentioned metal phthalocyanine-MOF hybrid material combined with silicate gel modified microspheres in the preparation of fire-retardant materials, wherein the silicate gel modified microspheres are composed of hollow glass microspheres and a silicate gel layer covering the surface of the hollow glass microspheres, and the two are bonded together by a bonding action.

[0036] In one specific embodiment, to facilitate control of the thickness of the silicate gel layer to 100-300 nm, the silicate gel modified microspheres are mainly prepared through the following steps: Activated microspheres: Hollow glass microspheres are subjected to oxygen plasma treatment in an oxygen atmosphere to activate the surface of the hollow glass microspheres and introduce hydroxyl functional groups to obtain hydroxyl-modified microspheres. Sodium silicate-coated microspheres: Hydroxyl-modified microspheres are added to a 5%-10% sodium silicate aqueous solution and stirred at 60-80℃ for 1-2 hours to uniformly coat the surface of the microspheres with sodium silicate, forming a secondary modification system for microspheres. Gel-modified microspheres: Dilute acid is added to the microsphere secondary modification system and the pH is adjusted to 6.5-7.0 to hydrolyze and condense sodium silicate to form a silicate gel layer. The gel layer is then filtered, washed, and dried at 100-110 °C for 1.5-2.5 hours to obtain the silicate gel-modified microspheres.

[0037] In the preparation of the silicate gel-modified microspheres, the purpose of the microsphere activation step is to provide chemical bonding sites for subsequent sodium silicate coating. Its effectiveness can be verified by conventional characterization methods such as contact angle testing, XPS, or FTIR. There is no need to limit the specific amount of hydroxyl groups introduced, as long as the coating layer can form uniformly and stably. In this step, existing methods are used to treat the hollow glass microspheres with oxygen plasma in an oxygen atmosphere. During oxygen plasma treatment, high-energy oxygen plasma particles break the Si-O-Si bonds on the surface of the glass microspheres, forming unsaturated active sites. These active sites react with active oxygen species or trace amounts of water vapor in the plasma, thereby introducing hydroxyl functional groups onto the surface of the glass microspheres and enhancing surface reactivity.

[0038] During the process of coating the microspheres with sodium silicate, after the hydroxyl-modified microspheres are added to the sodium silicate aqueous solution, the sodium silicate undergoes hydrolysis in the water to generate silicate ions (HSiO3). -The microspheres contain silica monomers (Si(OH)4). Under heating conditions of 60-80℃, these silica monomers undergo a condensation reaction to form oligomers containing siloxane bonds (Si-O-Si). At this point, the hydroxyl functional groups (Si-OH) introduced onto the surface of the microspheres through plasma treatment play a crucial role: on the one hand, the Si-OH on the surface of the microspheres undergoes a dehydration condensation reaction with the silica oligomers in the solution, forming stable Si-O-Si covalent bonds. This allows the silica oligomers to preferentially nucleate and grow on the surface of the microspheres, rather than spontaneously condensing in the solution; this is known as "chemical anchoring." On the other hand, the hydroxyl groups on the surface of the microspheres physically adsorb some of the silica oligomers through hydrogen bonding, further enhancing the interfacial bonding. As the reaction time increases, the silica oligomers continuously condense and crosslink, gradually forming a continuous, dense three-dimensional network silicate gel layer on the surface of the microspheres. During this process, most of the hydroxyl groups on the surface of the microspheres are consumed and converted into Si-O-Si bonds through the condensation reaction, with a small amount remaining at the interface between the microspheres and the gel layer. Finally, by adjusting the reaction temperature to 60-80℃, the reaction time to 1-2 hours, and the sodium silicate concentration to 5%-10%, the thickness of the resulting silicate gel layer can be controlled within the range of 100-300 nm.

[0039] In the step of coating microspheres with sodium silicate, the preferred mass ratio of the hollow glass microspheres to the sodium silicate in the sodium silicate aqueous solution is 1:0.2-1:0.5. That is, if a 10% sodium silicate aqueous solution is used, 200-500 mL of sodium silicate aqueous solution needs to be added for every 100g of hollow glass microspheres; if a 5% sodium silicate aqueous solution is used, 400-1000 mL of sodium silicate aqueous solution needs to be added. This ratio is determined mainly based on the following four considerations: First, hollow glass microspheres have a low density and a large volume for the same mass, requiring a sufficient liquid volume to ensure that the microspheres are completely submerged and freely agitated during stirring, achieving uniform coating; Second, the target thickness of the silicate gel layer is 100-300 μm. nm is the optimal thickness required for high-temperature ceramization reinforcement. Too low a concentration (sodium silicate to microsphere mass ratio below 0.2) will result in an excessively thin or discontinuous gel layer, failing to form an effective ceramic phase protective layer at high temperatures. Too high a concentration (ratio above 0.5) will result in an excessively thick gel layer, increasing brittleness and cracking, thus reducing the thermal insulation effect. Third, excessive use of sodium silicate increases the difficulty of post-treatment washing and wastewater generation, which is detrimental to process economy. Fourth, in experimental operation, the appropriate concentration can be judged by observing the following phenomena: after the reaction, pouring the supernatant, if the liquid is light milky white, indicates the formation of a uniform nanoscale gel, indicating an appropriate concentration; if it is completely clear, it indicates insufficient sodium silicate concentration or concentration; if it is too viscous or even forms blocky gels, it indicates excessive concentration. Therefore, controlling the mass ratio of hollow glass microspheres to sodium silicate at 1:0.2-1:0.5 is the optimal choice to balance coating effect, ceramization performance, and process economy.

[0040] The main purpose of the gel-modified microsphere step is to trigger further hydrolysis and condensation crosslinking of sodium silicate, thereby forming a stable silicate gel layer on the surface of the microspheres. Under alkaline conditions (pH>10), sodium silicate mainly exists as silicate ions (HSiO3). - It exists in oligomer form and the degree of condensation reaction is low, with the coating layer still in a soluble or semi-soluble state. When dilute acid is slowly added dropwise to lower the pH value, the hydrogen ions (H+) in the system... + First, it neutralizes the negative charge carried by silicate ions, eliminating electrostatic repulsion and promoting the approach of silicate molecules; simultaneously, H... + This process promotes the breaking and rearrangement of siloxane bonds (Si-O-Si), accelerating the formation of silicic acid monomers. When the pH drops to the neutral range of 6.5-7.0, the condensation reaction rate between silicic acid molecules reaches its maximum. The silanol groups (Si-OH) of adjacent silicic acid molecules undergo dehydration condensation to form a three-dimensional network of siloxane bonds (Si-O-Si), which gradually crosslink and harden into a water-insoluble silicate gel layer. This process is called the "sol-gel transition," which is the transformation from a flowable silicic acid sol to a solid gel network with a certain strength. At this point, the gel layer is firmly anchored to the surface of hollow glass microspheres through the previously formed Si-O-Si covalent bonds and hydrogen bonds. Subsequent filtration and washing steps are used to remove residual sodium ions (Na+) from the system. + The gel layer is dried at 100-110℃ to remove unreacted silicate ions and physically adsorbed water and some structural water, causing the gel layer to shrink and densify. This process ultimately yields modified hollow glass microspheres with a continuous, dense silicate gel layer on the surface, which helps ensure stable product quality and batch consistency. The dilute acid used in the gel modification process can be dilute hydrochloric acid, dilute sulfuric acid (H2SO4), dilute nitric acid (HNO3), acetic acid (CH3COOH), etc.

[0041] The main reason why the aforementioned metal phthalocyanine-MOF hybrid material combined with silicate gel-modified microspheres can be used in the preparation of fire-retardant materials is that: when the fire temperature is ≥500℃, ZIF-8@MTAPc undergoes a multi-metal ceramicization reaction with the silicate on the surface of the silicate gel-modified microspheres: the ZIF-8 core decomposes to generate ZnO; the MTPAc shell decomposes to generate MO (CuO / ZnO / Fe2O3); ZnO and MO react with silicate to generate a ZnSiO3 and MSiO3 composite metal silicate ceramic phase; this composite metal silicate ceramic phase is embedded in the carbon layer, forming a reinforced structure similar to "reinforced concrete," which can improve the thermal stability and mechanical strength of the carbon layer and delay the cracking and peeling of the carbon layer; at the same time, the porous structure of ZIF-8 and MTPAc adsorbs smoke particles. Therefore, by combining the metal phthalocyanine-MOF hybrid material with silicate gel-modified microspheres, a synergistic effect of multiple flame-retardant mechanisms, including gas-phase flame retardancy, condensed-phase flame retardancy, ceramicization reinforcement, and graphitization reinforcement thermal barrier, is achieved.

[0042] Fourthly, this invention provides a composite flame retardant comprising a uniformly mixed metal phthalocyanine-MOF hybrid material and silicate gel-modified microspheres, wherein the mass ratio of the two is 12-22 : 8-15. Thus, through the compounding of ZIF-8@metal phthalocyanine and silicate gel-modified microspheres, a synergistic effect of multiple flame retardant mechanisms is achieved: ZIF-8 and metal phthalocyanine decompose and release non-combustible gases such as CO2, N2, and NH3 to achieve gas-phase flame retardancy; ZnO and MO catalyze char formation, forming a dense char layer to achieve condensed-phase flame retardancy; the multi-element metal silicate ceramic phase enhances the strength of the char layer, delays char layer cracking and detachment, and provides long-term barrier protection; the large π structure of metal phthalocyanine promotes graphitization of the char layer, forming a dense protective layer that effectively inhibits the escape of combustible volatiles and significantly reduces smoke and CO release; simultaneously, the porous structure of ZIF-8 and metal phthalocyanine synergistically physically adsorbs smoke particles, playing a role in smoke suppression and toxicity reduction; the hollow structure of the hollow glass microspheres provides physical insulation, creating a thermal barrier.

[0043] Fifthly, this invention provides the application of the aforementioned metal phthalocyanine-MOF hybrid material or the aforementioned composite flame retardant in the preparation of fire-resistant materials. The matrix material of the fire-resistant material can be a polymer such as rigid polyvinyl chloride (UPVC), epoxy resin (EP), polyurethane (PU) foam, or polyolefin (PP / PE) cable material, with rigid polyvinyl chloride being the preferred matrix material. The aforementioned composite flame retardant exhibits the best flame-retardant effect in rigid polyvinyl chloride fire-resistant building materials, and also demonstrates good synergistic flame-retardant effects in epoxy resin composites, polyurethane insulation foam, and polyolefin cable materials. When the aforementioned composite flame retardant is applied to rigid polyvinyl chloride materials, the two can work together to form a stable and dense protective char layer, effectively inhibiting the release of smoke and toxic gases, meeting the usage standards for fire-resistant building profiles. The aforementioned composite flame retardant, when applied to epoxy resin systems, can improve the material's thermal stability and charring ability, making it suitable for flame-retardant structural components and encapsulation materials. Adding the aforementioned composite flame retardant to polyurethane foam can effectively prevent molten dripping, improving the fire safety of insulation materials. When the above-mentioned composite flame retardant is applied to polyolefin cable materials, it can achieve low-smoke, environmentally friendly flame retardant effects, taking into account both material performance and flame retardant properties.

[0044] Sixthly, the present invention provides a flame-retardant modified UPVC composite material, mainly prepared by melt blending the following raw materials in parts by weight: 100 parts of PVC resin with a degree of polymerization of 1000-1200, 12-22 parts of the above-mentioned metal phthalocyanine-MOF hybrid material, 8-15 parts of the above-mentioned silicate gel modified microspheres, 3-5 parts of calcium-zinc stabilizer, 2-4 parts of acrylate processing aid (ACR), 5-8 parts of resin-type chlorinated polyethylene (CPE), 4-6 parts of titanium dioxide, 0.5-1.5 parts of calcium stearate, and 0.3-0.8 parts of polyethylene wax. Preferably, the metal phthalocyanine-MOF hybrid material is composed of particles with a size of 200-600 nm. The raw materials used in the flame-retardant modified UPVC composite material are all commercially available industrial-grade products. Specifically: the calcium-zinc stabilizer is a calcium-zinc composite organic acid salt stabilizer with a calcium content ≥6.5% and a zinc content ≥10.5%; the ACR processing aid is a core-shell structured acrylate copolymer with a molecular weight of 300,000-1,000,000; the chlorinated polyethylene is a chlorinated polyethylene elastomer with a chlorine content of 35%-38%; the titanium dioxide is rutile titanium dioxide; the calcium stearate is a saturated fatty acid calcium salt; and the polyethylene wax is a low-density polyethylene homopolymer with a softening point of 100-115℃, a melt viscosity of 10-60 cps at 140℃, a penetration of 3-8 dmm, a molecular weight of 1500-5000, and is non-oxidizing. Applicable commercially available varieties include, but are not limited to: Qingdao Haihao H100P and H108P, Thailand SCG LP0040P, Thailand SQI H108, Honeywell AC-6A, etc. The flame-retardant modified UPVC composite material has an oxygen index ≥35%, a vertical burning rating of V-0, a smoke density rating SDR ≤42, a back-fire surface temperature rise rate ≤16℃ / min, and the composite char layer formed after being exposed to fire remains intact and crack-free after being burned at 500℃ for 15 minutes.

[0045] In a seventh aspect, the present invention provides a method for preparing the above-mentioned flame-retardant modified UPVC composite material, comprising: The PVC resin, calcium-zinc stabilizer, acrylate processing aid, resin-type chlorinated polyethylene, titanium dioxide, calcium stearate and polyethylene wax are put into a high-speed mixer with a stirring speed of 800-1200 r / min and stirred and mixed at 80-100℃ for 5-8 minutes to obtain the matrix raw material premix. Next, add the aforementioned metal phthalocyanine-MOF hybrid material and silicate gel modified microspheres to the high-speed mixer, and continue stirring and mixing for 8-10 minutes, with the mixing temperature controlled at 100-110℃, to obtain the UPVC fire-retardant raw material mixture. In this step, the mixing temperature is precisely controlled within the range of 100-110℃, which can ensure that the PVC particles are moderately softened to adsorb each component and expel moisture, and can also avoid thermal degradation and additive failure. This is the optimal process window for achieving uniform dispersion of flame retardants and ensuring the stable quality of subsequent extruded profiles. The UPVC fire-retardant raw material mixture is fed into a parallel twin-screw extruder for melt blending and extrusion. The extruder temperature is set as follows: Zone 1 160-165℃, Zone 2 165-170℃, Zone 3 170-175℃, Zone 4 170-175℃, and Die Head 165-170℃. The screw speed is 150-200 r / min to obtain the flame-retardant modified UPVC composite material.

[0046] Eighthly, based on the excellent fire-retardant, heat-insulating, sound-insulating, and corrosion-resistant properties of the UPVC composite material, this invention provides an application of the above-mentioned flame-retardant modified UPVC composite material in the preparation of door and window profiles, flame-retardant building pipes, interior decorative wall panels, wire and cable insulation sheaths, and automotive interior parts.

[0047] Ninthly, the present invention provides a finished UPVC fireproof door and window frame profile, the material of which is the aforementioned flame-retardant modified UPVC composite material. Further, the extrudate of the UPVC fireproof raw material mixture is melt-blended and formed into a door and window profile through a mold, and then vacuum cooled and shaped, and traction-cut to obtain the finished product.

[0048] The raw material cost of the UPVC fireproof door and window frame profile is far lower than that of traditional fireproof thermally broken aluminum and steel fireproof windows. It can precisely meet the fireproof door and window needs of high-rise buildings, public buildings, and chemical / coastal corrosive areas, filling the market gap in existing door and window materials that balance fire resistance, energy saving, and corrosion resistance, as well as high performance and low cost. Therefore, in a tenth aspect, this invention provides an application of the aforementioned UPVC fireproof door and window frame profile in fireproof doors and windows of high-rise buildings, public buildings, and industrial buildings (such as chemical plants and coastal facilities).

[0049] The technical solution to be protected by the present invention will be further explained below with reference to specific embodiments. Example 1 (ZIF-8@CuTAPc + modified hollow glass microspheres)

[0050] This embodiment provides a ZIF-8@CuTAPc hybrid material and its preparation method, which includes the following steps: (1) Synthesis of ZIF-8: 6.16 g of 2-methylimidazole was dissolved in 100 mL of methanol, and 2.94 g of zinc nitrate hexahydrate (Zn(NO3)2•6H2O) was dissolved in 100 mL of methanol. After mixing, the mixture was stirred at room temperature for 2 hours, centrifuged, washed and dried to obtain ZIF-8 particles with a particle size concentrated in 180-350 nm.

[0051] (2) Preparation of ZIF-8-NH2: 5 g of ZIF-8 was dispersed in 80 mL of ethylenediamine and reacted at 110 °C for 24 hours. After centrifugation and washing, ZIF-8-NH2 was obtained.

[0052] (3) Synthesis of tetraaminophthalocyanine copper (CuTAPc): 5 g of 4-nitrophthalonitrile was mixed and ground with 1.2 g of copper chloride, 10 g of urea and 0.2 g of ammonium molybdate, and melted at 220 °C for 3 hours. After cooling, it was washed and dried to obtain tetranitrophthalocyanine copper. It was dissolved in 100 mL of 10% sodium sulfide aqueous solution and reacted at 70 °C for 3 hours to reduce it. After centrifugation, washing and drying, CuTAPc particles were obtained.

[0053] (4) Grafting reaction: 4 g of ZIF-8-NH2 and 1 g of CuTAPc were dispersed in 100 mL of DMF, and 0.5 g of DCC was added. The reaction was carried out at 100 °C for 12 hours. After centrifugation, washing, and drying, ZIF-8@CuTAPc core-shell hybrid materials with a particle size concentration of 220-420 nm were obtained, such as... Figure 2 As shown.

[0054] This embodiment also provides a composite flame-retardant material, comprising the above-mentioned ZIF-8@CuTAPc core-shell hybrid material and silicate gel-modified microspheres, with a mass ratio of 3:2. The silicate gel-modified microspheres are prepared by the following method: Hollow glass microspheres with a particle size of 10-50 μm and a wall thickness of 1-2 μm were placed in the reaction chamber of a plasma treatment device and evacuated to a chamber pressure ≤9 Pa. Oxygen was introduced and the oxygen flow rate was controlled at 0.2-0.5 L / min. The microspheres were treated for 4 minutes at a power of 120-130 W. During the treatment, the microspheres were kept in a state of agitation to ensure that their surface was uniformly activated and hydroxyl functional groups were introduced to obtain hydroxyl-modified microspheres. 2) The hydroxyl-modified microspheres were added to an 8% sodium silicate aqueous solution, and the mass ratio of hollow glass microspheres to sodium silicate was controlled to be 1:0.35. The mixture was stirred and reacted at about 70°C for 1.5 hours to uniformly coat the surface of the microspheres with sodium silicate. 3) Slowly add 0.1 mol / L dilute hydrochloric acid to the reaction system in step 2) to adjust the pH to 6.5-7.0, so that sodium silicate hydrolyzes and condenses to form a silicate gel layer, which coats the surface of the hollow glass microspheres; filter, wash, and dry at 105°C for 2 hours to obtain the silicate gel modified microspheres.

[0055] This embodiment also provides a UPVC fireproof door and window frame profile and its preparation method, which specifically includes the following steps: The raw materials are weighed according to the following parts by weight: 100 parts of PVC resin with a degree of polymerization of 1000, 30 parts of the composite flame retardant material provided in this embodiment, 4 parts of calcium-zinc stabilizer (calcium content ≥6.5%, zinc content ≥10.5%), 3 parts of ACR processing aid, 6 parts of resin-type CPE, 5 parts of titanium dioxide (rutile type), 1 part of calcium stearate (saturated fatty acid calcium salt), and 0.5 parts of PE wax; wherein, the ACR processing aid is a core-shell structure acrylate copolymer with a molecular weight of 300,000-1,000,000; the chlorine content in the resin-type CPE is 35%-38%; the PE wax is a low-density polyethylene homopolymer with a softening point of 100-115℃, a melt viscosity of 10-60cps at 140℃, a penetration of 3-8 dmm, a molecular weight of 1500-5000, and is non-oxidizing.

[0056] Raw material premixing: The PVC resin, calcium zinc stabilizer, acrylate processing aid, chlorinated polyethylene, titanium dioxide, calcium stearate, and PE wax are put into a high-speed mixer and stirred for 7 minutes at 90°C with a speed of about 900 r / min to obtain the matrix raw material premix. Add flame retardant components: Add the above-mentioned composite flame retardant material to a high-speed mixer, continue stirring and mixing for 8-10 minutes, and control the mixing temperature at 100-110℃ to ensure that the components are fully and evenly dispersed to obtain UPVC fireproof raw material mixture. Melt blending extrusion: The UPVC fire-retardant raw material mixture is fed into a parallel twin-screw extruder for melt blending extrusion to obtain a molten flame-retardant modified UPVC composite material; wherein, the extruder temperature is set as follows: Zone 1 160-165℃, Zone 2 165-170℃, Zone 3 170-175℃, Zone 4 170-175℃, and Die head 165-170℃, and the screw speed is 150-200 r / min; Molding and shaping: The molten flame-retardant modified UPVC composite material extruded in the previous step is molded into door and window profiles through a mold, and then vacuum cooled and shaped, and traction cut to obtain the finished UPVC fireproof door and window frame profiles.

[0057] Performance testing: (1) Limiting Oxygen Index (LOI) test: conducted according to GB / T 2406.2-2009, the profile was cut into 120×6.5×3mm strips. The test result was 36.2%, indicating that the material has good flame retardant properties.

[0058] (2) Vertical burning test: According to GB / T 2408-2008, the profile was cut into 130×13×3mm strips. After two 10-second ignitions, the afterflame time of the strip in Example 1 was 2.1 seconds and 1.8 seconds, respectively, and no molten droplets ignited the degreased cotton, reaching the V-0 level.

[0059] (3) Smoke density rating (SDR) test: conducted according to GB / T 8627-2007, the profile was cut into strips of 25.4×25.4×3mm. The test result was 38, indicating a low smoke density.

[0060] (4) Back-fire surface temperature rise test: The profile was made into a 300×300mm test plate and tested according to the ISO 834 fire temperature rise curve. The back-fire surface temperature rise was 14.5℃ / min after 60 minutes.

[0061] (5) Mechanical property test: The tensile strength was tested according to GB / T 1040.2-2006 and the result was 47.2MPa; the unnotched impact strength of the simply supported beam was tested according to GB / T 1043.1-2008 and the result was 32.5kJ / m².

[0062] (6) Observation of char layer integrity: The profile sample was placed in a muffle furnace and burned at 500°C for 15 minutes. After cooling, it was observed. The char layer formed by the UPVC fireproof door and window frame profile provided in Example 1 during the combustion process was complete and the surface was dense. There was no obvious peeling when pressed with a finger and no visible cracks. Example 2 (ZIF-8@ZnTAPc + modified hollow glass microspheres)

[0063] This embodiment provides a ZIF-8@ZnTAPc hybrid material and its preparation method. The preparation method is basically the same as that in Example 1, except that zinc chloride is used instead of copper chloride in this embodiment, and the ZIF-8@ZnTAPc core-shell hybrid material with a particle size concentrated in 210-420 nm is finally obtained.

[0064] This embodiment also provides a composite flame-retardant material, comprising the ZIF-8@ZnTAPc core-shell hybrid material and silicate gel-modified microspheres provided in this embodiment, with a mass ratio of 1:1. The silicate gel-modified microspheres used in this embodiment are the same as those used in Example 1.

[0065] This embodiment also provides a UPVC fireproof door and window frame profile and its preparation method. The preparation method is basically the same as that in Embodiment 1, except that the composite flame retardant material in Embodiment 1 is replaced with the same mass of the composite flame retardant material provided in this embodiment.

[0066] Using the same performance testing method as in Example 1, the performance test results of the UPVC profile in this example are as follows: Limiting oxygen index: 35.8%; Vertical burning rating: V-0 (afterflame time 2.5 seconds, 2.2 seconds); Smoke density rating: 40; Back-fired surface temperature rise rate (60 min): 15.2℃ / min; Tensile strength: 46.8 MPa; Impact strength: 32.0 kJ / m 2; Carbon layer condition: After being burned at 500℃ for 15 minutes, the carbon layer was intact, with minor cracks but no peeling. Example 3 (ZIF-8@FeTAPc + modified hollow glass microspheres)

[0067] This embodiment provides a ZIF-8@FeTAPc hybrid material and its preparation method. The preparation method is basically the same as that in Example 1, except that: in this embodiment, ferrous chloride is used instead of copper chloride to finally obtain a ZIF-8@FeTAPc core-shell hybrid material with a particle size concentrated in the range of 200-420 nm.

[0068] This embodiment also provides a composite flame-retardant material, comprising the ZIF-8@FeTAPc core-shell hybrid material and silicate gel-modified microspheres provided in this embodiment, with a mass ratio of 11:10. The silicate gel-modified microspheres used in this embodiment are the same as those used in Example 1.

[0069] This embodiment also provides a UPVC fireproof door and window frame profile and its preparation method. The preparation method is basically the same as that in Embodiment 1, except that 32 parts of the above-mentioned composite flame retardant material provided in this embodiment are used instead of 30 parts of the composite flame retardant material in Embodiment 1.

[0070] Using the same performance testing method as in Example 1, the performance test results of the UPVC profile in this example are as follows: Limiting oxygen index: 36.5%; Vertical burning rating: V-0 (afterflame time 1.9 seconds, 1.7 seconds); Smoke density rating: 36; Back-fired surface temperature rise rate (60 min): 13.8 ℃ / min; Tensile strength: 47.5 MPa; Impact strength: 32.8 kJ / m 2 ; Carbon layer condition: After being burned at 500℃ for 15 minutes, the carbon layer is intact and dense, without cracks.

[0071] Comparative Example 1 (Pure UPVC) This comparative example provides a UPVC fireproof door and window frame profile, the preparation method of which is basically the same as that of Example 1. The main difference is that the composite flame-retardant material in Example 1 is not added in this comparative example.

[0072] Comparative Example 2 (ZIF-8@CuTAPc added only, hollow glass microspheres not added) This comparative example provides a UPVC fireproof door and window frame profile, the preparation method of which is basically the same as that of Example 1. The main difference is that 18 parts of ZIF-8@CuTAPc provided in Example 1 are used in this comparative example to replace 30 parts of composite flame retardant material in Example 1. That is, the silicate gel modified microspheres used in Example 1 are omitted from the flame retardant material of this comparative example.

[0073] Comparative Example 3 (hollow glass microspheres added only, ZIF-8@CuTAPc not added) This comparative example provides a UPVC fireproof door and window frame profile, the preparation method of which is basically the same as that of Example 1. The main difference is that in this comparative example, 10 parts of silicate gel modified microspheres used in Example 1 are used instead of 30 parts of composite flame retardant material in Example 1. That is, the ZIF-8@CuTAPc provided in Example 1 is omitted from the flame retardant material of this comparative example.

[0074] Comparative Example 4 (ZIF-8 and CuTAPc physically mixed, without chemical grafting) This comparative example provides a UPVC fireproof door and window frame profile, the preparation method of which is basically the same as that of Example 1. The main difference is that in this comparative example, 14.4 parts of ZIF-8 and 3.6 parts of CuTAPc are physically mixed in equal mass to replace the ZIF-8@CuTAPc hybrid material in Example 1. That is, the ZIF-8 and CuTAPc used in this comparative example are not chemically grafted.

[0075] The performance of the UPVC fireproof door and window frame profiles provided in Comparative Examples 1-4 was tested using the same performance testing method as in Example 1. The results are shown in Table 1.

[0076] Table 1 Performance test results of the UPVC fireproof door and window frame profiles provided in Example 1 and Comparative Examples 1-4 Limiting oxygen index (%) 36.2 18.5 33.5 24.5 31.5 Vertical burning rating V-0: after flame time 2.1 s, 1.8 s No rating V-0: after flame time 2.8 s, 2.5 s V-2 V-1 : after flame time 5.2 s, 4.8 s Smoke density rating (SDR) 38 85 48 68 52 Back face temperature rise rate (°C / min) 14.5 45.2 20.5 28.5 23.5 Tensile strength (MPa) 47.2 41.5 44.2 45.0 43.5 Impact strength (kJ / m2) 32.5 25.2 28.5 29.5 27.8 Char layer integrity Complete and compact No char layer With micro-cracks Loose cracks Crack drop out Among them, the phenomenon of "no rating" in the "vertical burning rating" test item in the table is: the sample continues to burn to the fixture, and the melt drips and ignites the degreased cotton; the phenomenon of "V-2" is: there is afterflame but there is a tendency to self-extinguish, and there are melt drips.

[0077] As can be seen from Table 1: Compared with Comparative Example 1 (pure UPVC), Example 1 showed a 95.7% increase in limiting oxygen index, a 55.3% decrease in smoke density rating, a 67.9% decrease in back-fire surface temperature rise rate, an improvement in vertical combustion rating from no rating to V-0, and significant improvements in mechanical properties.

[0078] Compared with Comparative Example 2 (ZIF-8@CuTAPc only, without microspheres), Example 1 showed a 20.8% reduction in smoke density level, a 29.3% reduction in the rate of temperature rise on the unexposed side, and an improvement in the carbon layer from having microcracks to being complete and dense, indicating that the addition of hollow glass microspheres significantly enhanced the thermal insulation effect and structural integrity of the carbon layer.

[0079] Compared with Comparative Example 3 (microbeads only, without ZIF-8@CuTAPc), Example 1 showed a 47.8% increase in limiting oxygen index, a 44.1% decrease in smoke density level, and a 49.1% decrease in back-fire surface temperature rise rate, indicating that the catalytic char formation and ceramicization of ZIF-8@CuTAPc are key to improving flame retardant performance.

[0080] Compared to Comparative Example 4 (physical mixing), Example 1 showed a 14.9% increase in limiting oxygen index, a 26.9% decrease in smoke density, a 38.3% decrease in the rate of temperature rise on the unexposed side, and an improvement in the char layer from cracked and flaking to a complete and dense structure. This indicates that the chemical grafting of ZIF-8 with metal phthalocyanine is key to achieving their synergistic effect, and physical mixing cannot achieve the same enhancement.

[0081] Therefore, the ZIF-8@metal phthalocyanine core-shell flame retardant provided in this embodiment of the invention exhibits a significant synergistic effect with the surface-modified hollow glass microspheres. The core-shell structure formed by chemical grafting tightly binds ZIF-8 and metal phthalocyanine at the molecular level. Upon exposure to fire, the ZnO generated from the decomposition of ZIF-8 and the MO generated from the decomposition of metal phthalocyanine form a multi-metal oxide system, which reacts with the silicates on the surface of the microspheres to generate a composite metal silicate ceramic phase. Simultaneously, the large π structure of the metal phthalocyanine promotes the graphitization of the carbon layer, thereby forming a dense and high-strength composite carbon layer. Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific embodiments of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of the present invention, and all such modifications should be covered within the scope of the technical solution claimed in the present invention.

Claims

1. A metal phthalocyanine-MOF hybrid material, characterized in that, It includes ZIF-8 as the core and tetraaminometal phthalocyanine as the outer shell.

2. The hybrid material according to claim 1, characterized in that, It is prepared by grafting tetraaminometal phthalocyanine onto ZIF-8 particles through an amino condensation reaction under the action of an amino condensing agent to form a core-shell structure; wherein the amino condensing agent includes N,N'-dicyclohexylcarbodiimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.

3. A method for preparing the hybrid material according to claim 1 or 2, comprising the steps of: Amination of ZIF-8: ZIF-8 nanoparticles were subjected to amination treatment to obtain the amination-treated ZIF-8 particles. Amino condensation grafting reaction: Under the action of an amino condensing agent, the amino-modified ZIF-8 particles and tetraaminometal phthalocyanine undergo an amino condensation reaction to graft the tetraaminometal phthalocyanine onto the ZIF-8 nanoparticles, forming a core-shell structure.

4. The preparation method according to claim 3, characterized in that, The amination step of ZIF-8 includes: first dispersing the ZIF-8 nanoparticles in an amino compound, and then heating and reacting at 90-150℃ for 12-48 hours to obtain the amination ZIF-8 particles; wherein, the solid-liquid ratio of the ZIF-8 nanoparticles to the amino compound is (5-12) g : (80-200) mL, and the amino compound is selected from at least one of ethylenediamine, 3-aminopropyltriethoxysilane, 3-amino-1,2,4-triazole, and polyethyleneimine.

5. The preparation method according to claim 3, characterized in that, The amino condensation grafting reaction step includes: dispersing the aminated ZIF-8 particles and the tetraamino metal phthalocyanine in N,N-dimethylformamide at a mass ratio of 3-5:1, adding the amino condensing agent, and reacting at 80-120℃ for 8-16 hours to obtain the metal phthalocyanine-MOF hybrid material.

6. The application of the hybrid material of claim 1 or 2 combined with silicate gel-modified microspheres in the preparation of fire-retardant materials, wherein, The silicate gel modified microspheres consist of hollow glass microspheres and a silicate gel layer coating the surface of the hollow glass microspheres.

7. The application according to claim 6, characterized in that, The silicate gel-modified microspheres are mainly prepared by the following methods: Activated microspheres: Hollow glass microspheres are treated with oxygen plasma to activate the surface of the hollow glass microspheres and introduce hydroxyl functional groups to obtain hydroxyl-modified microspheres. Sodium silicate-coated microspheres: Hydroxyl-modified microspheres are added to an aqueous solution of sodium silicate to carry out a surface coating reaction, so that sodium silicate is uniformly coated on the surface of the microspheres, forming a secondary modification system of microspheres; Gel-modified microbeads: The pH of the secondary modification system of the microbeads is adjusted to 6.5-7.0 to hydrolyze and condense sodium silicate to form a silicate gel layer, which is then dried to obtain the silicate gel-modified microbeads.

8. A composite flame retardant, characterized in that, The mixture comprises a uniformly mixed hybrid material as described in claim 1 or 2 and silicate gel modified microspheres, wherein the mass ratio of the two is 12-22 : 8-15; wherein the silicate gel modified microspheres are composed of hollow glass microspheres and a silicate gel layer covering the surface of the hollow glass microspheres.

9. The application of the hybrid material according to claim 1 or 2 or the composite flame retardant according to claim 8 in the preparation of fire-retardant materials, wherein, The matrix material of the fireproof material is an organic polymer material.

10. A flame-retardant modified UPVC composite material, characterized in that, It is mainly made by melt blending the following raw materials in parts by weight: 100 parts of PVC resin with a degree of polymerization of 1000-1200, 12-22 parts of the hybrid material as described in claim 1 or 2, 8-15 parts of silicate gel modified microspheres, 3-5 parts of calcium zinc stabilizer, 2-4 parts of acrylate processing aid, 5-8 parts of resin-type chlorinated polyethylene, 4-6 parts of titanium dioxide, 0.5-1.5 parts of calcium stearate, and 0.3-0.8 parts of polyethylene wax; wherein, the silicate gel modified microspheres are composed of hollow glass microspheres and a silicate gel layer covering the surface of the hollow glass microspheres.

11. A method for preparing the flame-retardant modified UPVC composite material according to claim 10, comprising: First, the PVC resin, calcium-zinc stabilizer, acrylate processing aids, resin-type chlorinated polyethylene, titanium dioxide, calcium stearate, and polyethylene wax are stirred and mixed to form a matrix raw material premix; then, the hybrid material and silicate gel modified microspheres are added and mixed evenly to form a UPVC fire-retardant raw material mixture; the UPVC fire-retardant raw material mixture is subjected to melt blending and extrusion treatment to obtain the flame-retardant modified UPVC composite material.

12. The preparation method according to claim 11, characterized in that, The method for forming the UPVC fire-retardant raw material mixture includes: mixing the hybrid material, silicate gel modified microspheres and matrix raw material premix at 100-110°C for 8-10 minutes, and the stirring speed is 800-1200 r / min.

13. The preparation method according to claim 11 or 12, characterized in that, The melt blending extrusion process includes: adding the UPVC fire-retardant raw material mixture into a parallel twin-screw extruder for melt blending extrusion, wherein the temperature of the parallel twin-screw extruder is set as follows: Zone 1 160-165℃, Zone 2 165-170℃, Zone 3 170-175℃, Zone 4 170-175℃, and Die Head 165-170℃, and the screw speed is 150-200 r / min, to obtain the flame-retardant modified UPVC composite material.

14. The application of the flame-retardant modified UPVC composite material of claim 10 in the preparation of door and window profiles, flame-retardant building pipes, interior decorative wall panels, wire and cable insulation sheaths or automotive interior parts.

15. A finished UPVC fireproof door and window frame profile, wherein the material is the flame-retardant modified UPVC composite material as described in claim 10.

Images