Flame-retardant graphite polystyrene board and preparation method thereof

Abstract

The invention relates to the technical field of building thermal insulation materials, in particular to a flame-retardant graphite polystyrene board and a preparation method thereof.The flame-retardant graphite polystyrene board comprises a board body formed by adhering a protective layer to the exterior of a base board; and connecting lugs are arranged at the four corners of the protective layer, connecting holes are formed in the inner surfaces of one ends of the connecting lugs, and fasteners are connected to the inner sides of the connecting holes in a screwed mode. By compounding the high-impact polystyrene matrix, the toughening copolymer, the nano reinforcing material and the micro-macro double-fiber reinforced rigid protective layer, the plate has extremely high impact resistance, bending resistance and cracking resistance, and can tolerate harsh working conditions in transportation and installation; and the protective layer fundamentally isolates the aging influence of ultraviolet rays, moisture and the like on the organic substrate, effectively locks the flame retardant in the substrate, prevents the flame retardant from migrating and volatilizing, and ensures the long-term stability of the flame retardant property.

Description

Technical Field

[0001] This invention relates to the field of building insulation materials technology, specifically to a flame-retardant graphite polystyrene board and its preparation method. Background Technology

[0002] Flame-retardant graphite polystyrene boards are widely used in building exterior wall insulation systems as a high-efficiency thermal insulation material. They improve both thermal insulation and fire resistance by adding graphite and flame retardants to a polystyrene substrate.

[0003] However, existing flame-retardant graphite polystyrene boards have been found to have insufficient mechanical properties and durability in practical use. These boards have poor impact resistance and are easily damaged during transportation, installation, or use. Furthermore, the added flame retardants can volatilize or migrate over long-term use, causing the flame-retardant performance to decline and affecting long-term safety and reliability. Secondly, there are fire safety concerns at high temperatures; the boards soften and decompose easily when exposed to high temperatures, and will burn upon contact with an open flame, producing molten drips and large amounts of toxic fumes, exacerbating the fire hazard. In addition, construction efficiency needs improvement; existing assembly methods for these boards are generally inefficient, affecting the overall construction progress. Therefore, we propose a flame-retardant graphite polystyrene board and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a flame-retardant graphite polystyrene board and its preparation method, which has the advantages of high impact resistance, long-lasting flame retardancy, high fire safety, and convenient construction. It solves the problems found in the actual use of existing flame-retardant graphite polystyrene boards, such as insufficient mechanical properties and durability, poor impact resistance, easy damage during transportation, installation, or use, and the volatilization or migration of added flame retardants during long-term use, which leads to the decay of flame retardant performance over time and affects the long-term safety and reliability. Secondly, there are fire safety hazards at high temperatures. The board is prone to softening and decomposition at high temperatures, and will burn when exposed to open flames, producing molten drips and a large amount of toxic fumes, which exacerbates the fire hazard. In addition, the construction efficiency needs to be improved. The existing assembly and combination methods of the boards are usually inefficient, which affects the overall construction progress.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a flame-retardant graphite polystyrene board, comprising: A plate formed by adhering a protective layer to the outside of a substrate; Connecting ears are provided at each of the four corners of the protective layer. A connecting hole is provided on the inner surface of one end of the connecting ear, and a fastener is screwed into the inner side of the connecting hole. The protective layer is made from the following raw materials in parts by weight: 45-55 parts ordinary silicate cement, 20-24 parts Class II fly ash (F grade), 20-25 parts S95 grade slag powder, 3-4 parts VAE type redispersible latex powder, 3-4 parts acrylic type redispersible latex powder, 0.3-0.5 parts KH-550 silane coupling agent, 0.5-0.9 parts inorganic ceramic fiber, 0.3-0.5 parts organic polypropylene fiber, 0.6-1 parts retarded polycarboxylate-based high-efficiency water-reducing agent, 0.05-0.15 parts sodium gluconate, 0.1-0.3 parts emulsion type silicone defoamer, 3-7 parts industrial grade talc powder, and 30-38 parts clean tap water; The substrate is made from the following raw materials in parts by weight: 75-85 parts high-impact polystyrene, 15-25 parts styrene-maleic anhydride copolymer, 10-14 parts expandable graphite, 9-11 parts microencapsulated ammonium polyphosphate, 5-7 parts melamine cyanurate, 1-3 parts zinc borate, 1-3 parts nano silica, 1-2 parts silicon carbide, 1-2 parts nano graphene sheets, 4-6 parts chemical foaming agent azodicarbonamide, 2-3 parts nucleating agent talc, 0.6-1 part KH-550 silane coupling agent, 0.8-1.2 parts polytetrafluoroethylene, 1-2 parts lubricant / dispersant, 0.2-0.4 parts antioxidant, 0.1-0.3 parts ultraviolet absorber, 0.8-1.2 parts smoke suppressant ammonium molybdate, and 0.4-0.6 parts antistatic agent.

[0006] Preferably, the four connecting ears are evenly distributed in a clockwise direction, and the connecting ears corresponding to the four plates can be sequentially attached and stacked vertically upwards.

[0007] Preferably, the upper corner of the protective layer is provided with a sealing groove, and the cross-section of the sealing groove is an arc-shaped structure with a depth of 1.5-2.5mm and a width of 3-5mm.

[0008] Preferably, the connecting ear and the protective layer are integrally cast and molded, and the thickness of the connecting ear 103 is 1.2-1.5 times the thickness of the protective layer.

[0009] Preferably, the length of the inorganic ceramic fiber is 3-6 mm, and the length of the organic polypropylene fiber is 9-12 mm.

[0010] Preferably, the styrene-maleic anhydride copolymer in the substrate raw material has a maleic anhydride content of 8-12 wt%.

[0011] Preferably, the nano-graphene sheets in the substrate material are functionalized graphene that has undergone hydroxylation modification, with a sheet diameter of 5-15 μm and a thickness of 1-5 nm.

[0012] A method for preparing a flame-retardant graphite polystyrene board includes the steps of substrate preparation, protective layer preparation, and lamination. The substrate preparation includes the following steps: S1. Premix: High-impact polystyrene, styrene-maleic anhydride copolymer, nucleating agent talc, lubricant / dispersant, antioxidant, ultraviolet absorber, antistatic agent and polytetrafluoroethylene are added to a high-speed mixer and mixed at 60-75℃ for 5-8 minutes to obtain premix A; S2. Flame retardant system mixing: Expandable graphite, microencapsulated ammonium polyphosphate, melamine cyanurate, zinc borate, nano silica, silicon carbide, nano graphene sheets, smoke suppressant ammonium molybdate, and KH-550 silane coupling agent are mixed evenly at low speed at room temperature to obtain flame retardant composite powder B. S3. Final mixing and foaming: Premix A, flame retardant composite powder B and chemical foaming agent azodicarbonamide are added to a twin-screw extruder, and after melt blending, extrusion, water cooling and pelletizing, foaming masterbatch is obtained. The masterbatch is then injected into a mold and foamed at a steam pressure of 0.12-0.15MPa and a temperature of 115-125℃. After holding the pressure and cooling, the substrate is demolded to obtain the substrate.

[0013] Preferably, the steps of preparing the protective layer and laminating it with the substrate include: P1. Mold preparation: Place the demolded substrate into the molding mold, which has cavities for forming connecting ears at the four corners of the substrate. P2. Slurry preparation: Dry mix ordinary silicate cement, Class F II fly ash, S95 grade slag powder, and industrial grade talc powder for 1-2 minutes; Add VAE-type and acrylic-type redispersible latex powder, KH-550 silane coupling agent, inorganic ceramic fiber, organic polypropylene fiber, and sodium gluconate, and continue dry mixing for 2-3 minutes; Dissolve the retarded polycarboxylate superplasticizer and emulsion silicone defoamer in some clean tap water, pour them into the mixture and stir for 3-5 minutes, then add the remaining water and stir until a uniform slurry with good flowability is obtained. P3. Casting and curing: The slurry is cast into the mold in which the substrate has been placed, filling the cavity of the connecting ear. After being compacted by vibration, the surface is smoothed and a sealing groove is opened. The substrate is then cured for 7 days at a temperature of 20±2℃ and a relative humidity of ≥95%. After demolding, the board body is obtained.

[0014] An exterior wall insulation system for buildings uses the aforementioned flame-retardant graphite polystyrene board as the insulation layer. Adjacent boards are connected to each other by fasteners passing through the connecting lugs, and the sealing grooves at the joints between the boards are filled with sealant.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses a composite of high-impact polystyrene matrix, toughening copolymer, nano-reinforcing materials, and a rigid protective layer reinforced with micro-macro dual fibers to give the board extremely high impact resistance, bending resistance, and crack resistance. It can withstand harsh working conditions during transportation and installation. Moreover, the protective layer fundamentally isolates the aging effects of ultraviolet rays and moisture on the organic substrate and effectively locks in the flame retardant in the substrate, preventing its migration and volatilization, thus ensuring the long-term stability of flame retardant performance.

[0016] 2. The substrate of the present invention adopts a multi-component synergistic flame retardant and smoke suppression system, including expanded graphite and microencapsulated flame retardant. The protective layer is a non-combustible inorganic material. When exposed to fire, the substrate expands into a dense carbon layer, while the protective layer acts as a robust heat insulation barrier. This dual action effectively inhibits the generation of molten drips, significantly reduces the release of toxic fumes, and greatly improves the fire safety level of buildings.

[0017] 3. This invention adopts a standardized, one-piece molded connecting ear, which enables rapid and accurate positioning and mechanized installation of the panels, eliminating the need for secondary on-site processing. Combined with the sealing groove design, it simplifies the joint sealing construction and makes the quality controllable, greatly improving the construction efficiency and overall airtightness, watertightness and fire resistance of the external wall insulation system. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the plate structure of the present invention; Figure 2 This is a schematic diagram of the multi-plate assembly structure of the present invention; Figure 3 This is a schematic diagram of the multi-plate split structure of the present invention.

[0019] In the diagram: 1. Plate body; 101. Protective layer; 102. Substrate; 103. Connecting ear; 104. Sealing groove; 2. Fastener. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The plate 1, protective layer 101, substrate 102, connecting ear 103, sealing groove 104 and fastener 2 components in this application are all general standard parts or components known to those skilled in the art. Their structure and principle can be known to those skilled in the art through technical manuals or conventional experimental methods.

[0022] Example 1: A flame-retardant graphite polystyrene board, comprising: A plate 1 formed by adhering a protective layer 101 to the outside of a substrate 102; Connecting ears 103 are provided at the four corners of the protective layer 101. Connecting holes are provided on the inner surface of one end of the connecting ears 103. Fasteners 2 are screwed into the inner side of the connecting holes. The four connecting ears 103 are evenly distributed in the clockwise direction, and the connecting ears 103 corresponding to the four plates 1 can be stacked in sequence vertically upward. A sealing groove 104 is provided at the upper corner of the protective layer 101. The cross-section of the sealing groove 104 is an arc-shaped structure with a depth of 1.5 and a width of 3. The connecting ears 103 and the protective layer 101 are integrally cast and molded, and the thickness of the connecting ears 103 is 1.2 times the thickness of the protective layer 101. The protective layer 101 is made of the following raw materials in parts by weight: The ingredients are: 45 parts ordinary silicate cement, 20 parts Class II fly ash (F grade), 20 parts S95 grade slag powder, 3 parts VAE type redispersible latex powder, 3 parts acrylic type redispersible latex powder, 0.3 parts KH-550 silane coupling agent, 0.5 parts inorganic ceramic fiber, 0.3 parts organic polypropylene fiber, 0.6 parts retarded polycarboxylate-based high-efficiency water-reducing agent, 0.05 parts sodium gluconate, 0.1 parts emulsion type silicone defoamer, 3 parts industrial grade talc powder, and 30 parts clean tap water. The length of the inorganic ceramic fiber is 3 mm, and the length of the organic polypropylene fiber is 9 mm. The substrate 102 is made from the following raw materials in parts by weight: The substrate 102 contains 75 parts high-impact polystyrene, 15 parts styrene-maleic anhydride copolymer (with a maleic anhydride content of 8 wt%), 10 parts expandable graphite, 9 parts microencapsulated ammonium polyphosphate, 5 parts melamine cyanurate, 1 part zinc borate, 1 part nano silica, 1 part silicon carbide, 1 part nano graphene sheet, 4 parts chemical foaming agent azodicarbonamide, 2 parts nucleating agent talc, 0.6 parts KH-550 silane coupling agent, 0.8 parts polytetrafluoroethylene, 1 part lubricant / dispersant, 0.2 parts antioxidant, 0.1 parts ultraviolet absorber, 0.8 parts smoke suppressant ammonium molybdate, and 0.4 parts antistatic agent. The nano graphene sheet in the substrate 102 material is hydroxylated modified functionalized graphene with a sheet diameter of 5 μm and a thickness of 1 nm.

[0023] Example 2: A flame-retardant graphite polystyrene board, comprising: A plate 1 formed by adhering a protective layer 101 to the outside of a substrate 102; Connecting ears 103 are provided at the four corners of the protective layer 101. Connecting holes are provided on the inner surface of one end of the connecting ears 103. Fasteners 2 are screwed into the inner side of the connecting holes. The four connecting ears 103 are evenly distributed in the clockwise direction, and the connecting ears 103 corresponding to the four plates 1 can be stacked in sequence vertically upward. A sealing groove 104 is provided at the upper corner of the protective layer 101. The cross-section of the sealing groove 104 is an arc-shaped structure with a depth of 2mm and a width of 4mm. The connecting ears 103 and the protective layer 101 are integrally cast and molded, and the thickness of the connecting ears 103 is 1.35 times the thickness of the protective layer 101. The protective layer 101 is made of the following raw materials in parts by weight: The ingredients are: 50 parts ordinary silicate cement, 22 parts Class II fly ash (F grade), 23 parts S95 grade slag powder, 3.5 parts VAE type redispersible latex powder, 3.5 parts acrylic type redispersible latex powder, 0.4 parts KH-550 silane coupling agent, 0.57 parts inorganic ceramic fiber, 0.4 parts organic polypropylene fiber, 0.8 parts retarded polycarboxylate-based high-efficiency water-reducing agent, 0.1 parts sodium gluconate, 0.2 parts emulsion type silicone defoamer, 5 parts industrial grade talc powder, and 34 parts clean tap water. The length of the inorganic ceramic fiber is 5 mm, and the length of the organic polypropylene fiber is 11 mm. The substrate 102 is made from the following raw materials in parts by weight: The substrate 102 material contains 80 parts of high-impact polystyrene, 20 parts of styrene-maleic anhydride copolymer (with a maleic anhydride content of 10 wt%), 12 parts of expandable graphite, 10 parts of microencapsulated ammonium polyphosphate, 6 parts of melamine cyanurate, 2 parts of zinc borate, 2 parts of nano-silica, 1.5 parts of silicon carbide, 1.5 parts of nano-graphene sheets, 5 parts of chemical foaming agent azodicarbonamide, 2.5 parts of nucleating agent talc, 0.8 parts of KH-550 silane coupling agent, 1 part of polytetrafluoroethylene, 1.5 parts of lubricant / dispersant, 0.3 parts of antioxidant, 0.2 parts of ultraviolet absorber, 1 part of smoke suppressant ammonium molybdate, and 0.5 parts of antistatic agent. The nano-graphene sheets in the substrate 102 material are hydroxylated modified functionalized graphene with a sheet diameter of 10 μm and a thickness of 3 nm.

[0024] Example 3: A flame-retardant graphite polystyrene board, comprising: A plate 1 formed by adhering a protective layer 101 to the outside of a substrate 102; Connecting ears 103 are provided at the four corners of the protective layer 101. Connecting holes are provided on the inner surface of one end of the connecting ears 103. Fasteners 2 are screwed into the inner side of the connecting holes. The four connecting ears 103 are evenly distributed in the clockwise direction, and the connecting ears 103 corresponding to the four plates 1 can be stacked in sequence vertically upward. A sealing groove 104 is provided at the corner of the upper end of the protective layer 101. The cross-section of the sealing groove 104 is an arc-shaped structure with a depth of 2.5 mm and a width of 5 mm. The connecting ears 103 and the protective layer 101 are integrally cast and molded, and the thickness of the connecting ears 103 is 1.5 times the thickness of the protective layer 101. The protective layer 101 is made of the following raw materials in parts by weight: The ingredients are: 55 parts ordinary silicate cement, 24 parts Class II fly ash (F grade), 25 parts S95 grade slag powder, 4 parts VAE type redispersible latex powder, 4 parts acrylic type redispersible latex powder, 0.5 parts KH-550 silane coupling agent, 0.9 parts inorganic ceramic fiber, 0.5 parts organic polypropylene fiber, 1 part retarded polycarboxylate-based high-efficiency water-reducing agent, 0.15 parts sodium gluconate, 0.3 parts emulsion type organosilicon defoamer, 7 parts industrial grade talc powder, and 38 parts clean tap water. The length of the inorganic ceramic fiber is 6 mm, and the length of the organic polypropylene fiber is 12 mm. The substrate 102 is made from the following raw materials in parts by weight: The substrate 102 material contains 85 parts high-impact polystyrene, 25 parts styrene-maleic anhydride copolymer (with a maleic anhydride content of 12 wt%), 14 parts expandable graphite, 11 parts microencapsulated ammonium polyphosphate, 7 parts melamine cyanurate, 3 parts zinc borate, 3 parts nano silica, 2 parts silicon carbide, 2 parts nano graphene sheets, 6 parts chemical foaming agent azodicarbonamide, 3 parts nucleating agent talc, 1 part KH-550 silane coupling agent, 1.2 parts polytetrafluoroethylene, 2 parts lubricant / dispersant, 0.4 parts antioxidant, 0.3 parts ultraviolet absorber, 1.2 parts smoke suppressant ammonium molybdate, and 0.6 parts antistatic agent. The nano graphene sheets in the substrate 102 material are hydroxylated functionalized graphene with a sheet diameter of 15 μm and a thickness of 5 nm.

[0025] I. Implementation Example Design Description Three formulations from Examples 1, 2, and 3 were selected to verify the adjustability and stability of the formulations; the process parameters strictly followed the scope defined in the claims, and the equipment models, operating details, and testing standards were clearly specified to ensure industrial repeatability.

[0026] II. Raw material specifications and formula details Basic specifications of raw materials (all industrial-grade compliant raw materials are used). Raw material categories Specific specifications Supplier (Example) High-impact polystyrene (HIPS) Melt flow rate (200℃ / 5kg) = 1.8g / 10min, cantilever beam impact strength (23℃) ≥ 16kJ / m² China Petroleum & Chemical Corporation Styrene-maleic anhydride copolymer (SMA) Maleic anhydride content 10wt%, heat distortion temperature ≥112℃, number average molecular weight 28000 Changzhou Xinri New Materials Co., Ltd. Expandable graphite (EG) 300 mesh, expansion ratio ≥ 220 times, fixed carbon content ≥ 92% Qingdao Tianheda Graphite Co., Ltd. Microencapsulated ammonium polyphosphate (MCAPP) Type II, degree of polymerization n≥1200, phosphorus content≥31.5%, nitrogen content≥14.2%, microcapsule encapsulation rate≥95%. Shandong Haiming Chemical Co., Ltd. Nanographene sheets Hydroxylated modified, with sheet diameters of 8-12 μm, thicknesses of 2-4 nm, and purity ≥99.2%. Nanjing Xianfeng Nanomaterials Technology Co., Ltd. Inorganic ceramic fibers Alumina-silica type, length 4-5mm, diameter 10-15μm, tensile strength ≥1.8GPa Zibo Luyang Energy-Saving Materials Co., Ltd. Organic polypropylene fiber Length 10mm, diameter 30μm, tensile strength ≥5.5cN / dtex, elastic modulus ≥150cN / dtex Jiangsu Heng Hui Chemical Fiber Co., Ltd. Retarded polycarboxylate superplasticizer Solid content 40%, water reduction rate ≥30%, retarding time 2-4h Beijing Oriental Yuhong Waterproof Technology Co., Ltd. III. Detailed Preparation Process (a) List of common equipment Equipment Name Model Specifications use high-speed mixer SHR-50L, speed 0-2000r / min, temperature control range room temperature -120℃ Premixing of substrate raw materials and mixing of flame retardant system Twin-screw extruder Model SHJ-65, length-to-diameter ratio 40:1, temperature control range: room temperature - 250℃ Substrate melt blending and granulation Steam foaming mold Custom rectangular mold (3000mm×600mm×50mm), pressure range 0-0.3MPa, temperature control range room temperature-150℃ Substrate foaming planetary mixer JSS-60L, speed 0-1500r / min Preparation of protective layer slurry Composite molding die Custom-designed ear cavity with connecting structure (size: 50mm×50mm×12mm) and sealing groove. Protective layer casting and composite Vertical vibration table ZDP-50 type, amplitude 0-1mm, frequency 0-60Hz Vibration compaction of protective layer slurry Standard curing room Model YH-40B, temperature control 20±2℃, humidity control ≥95%. Protective layer maintenance CNC laser cutting machine GWE-1530 model, accuracy ±0.05mm Connecting ear connecting hole processing (II) Substrate preparation steps (taking Example 2 as an example, the other examples only adjust the amount of raw materials, the process is the same) Premixing (step S1): Equipment debugging: Preheat the high-speed mixer to 68℃ and set the speed to 800r / min; Feeding sequence: First add 80 parts of high-impact polystyrene and 20 parts of SMA, and stir for 2 minutes to initially mix the resin particles; Then add 2.5 parts nucleating agent talc, 1.5 parts EBS, 0.3 parts antioxidant, 0.2 parts UV-531, 0.5 parts antistatic agent, and 1 part PTFE micro powder in sequence, and stir continuously for 6 minutes; Output standard: The material is in uniform granular form, without lumps or obvious dust, and the temperature is stable at around 70℃, thus obtaining premix A.

[0027] Flame retardant system mixing (step S2): Equipment debugging: Cool the high-speed mixer to room temperature and adjust the speed to 300r / min (low speed to avoid fiber breakage); Feeding sequence: First add 12 parts expandable graphite, 10 parts MCAPP, 6 parts MCA, and 2 parts zinc borate, and stir for 3 minutes; Add 2 parts of nano-silica, 1.5 parts of SiC nanowires, 1.5 parts of hydroxylated graphene, and 1 part of ammonium molybdate. Finally, spray with 0.8 parts of KH-550 silane coupling agent diluted 5 times and continue stirring for 8 minutes. Output standard: The powder is free from agglomeration, has no grainy feel when rubbed between the fingers, and the coupling agent is uniformly coated on the surface of the filler to obtain flame-retardant composite powder B.

[0028] Final mixing and foaming (step S3): Twin-screw extruder parameter settings: Section Feeding section (zone 1) Melting section (zone two) Blending section (zone three) Nose (Zone 4) temperature 148℃ 172℃ 180℃ 170℃ Screw speed 280r / min 300r / min 300r / min 290r / min Feeding and Granulation: Using a loss-in-weight weigher, 5 parts of premix A, flame-retardant composite powder B, and AC foaming agent are fed into an extruder in proportion. After the materials are melt-sheared and blended, they are extruded into strips through a Φ3mm die. The strips are cooled with 25℃ cooling water until there is no sticking on the surface. They are then cut into 3mm×3mm foaming masterbatches by a pelletizer. The moisture content of the masterbatches is controlled to be ≤0.3%. Steam foaming molding: The masterbatch is placed into a steam foaming mold preheated to 60°C, with a mold filling rate of 70%; saturated steam at 0.13MPa is introduced, the temperature is raised to 120°C, and the pressure is maintained for 4 minutes (to ensure that AC is fully decomposed and the cells grow uniformly); then the pressure is slowly released (pressure release rate 0.02MPa / s), and the mold is demolded after cooling to below 50°C to obtain a substrate 102 with dimensions of 3000mm×600mm×50mm; Post-treatment of substrate: After demolding, the substrate is placed in a curing chamber at 25°C and 60% humidity for 24 hours to eliminate internal stress and ensure dimensional stability.

[0029] (III) Protective layer preparation and composite steps (taking Example 2 as an example) Mold preparation (step P1): Mold cleaning: Apply a release agent (water-based silicone oil, coating thickness 0.05mm) to the inner wall of the composite molding mold to ensure that there are no foreign objects on the molding surface of the connecting ear cavity and the sealing groove; Substrate positioning: Place the cured substrate 102 into the center of the mold and fix it with the mold positioning pin. The gap between the substrate and the inner wall of the mold is uniform (2-3mm) to ensure that the protective layer thickness is consistent.

[0030] Slurry preparation (step P2): Dry mixing stage a: Add 50 parts of ordinary Portland cement, 22 parts of fly ash, 23 parts of slag powder and 5 parts of talc powder to a planetary mixer, rotate at 300 r / min and dry mix for 1.5 min to obtain uniform powder. Dry mixing stage b: Add 3.5 parts VAE latex powder, 3.5 parts acrylic latex powder, 4 parts KH-5500, 0.7 parts ceramic fiber, 0.4 parts polypropylene fiber, and 0.1 parts sodium gluconate. Adjust the speed to 500 r / min and continue dry mixing for 2.5 min to ensure that the fibers are dispersed and free of clumps. Wet mixing stage c: Take 35 parts of clean tap water, add 0.8 parts of polycarboxylate superplasticizer and 0.2 parts of silicone defoamer to 31.5 parts of water (accounting for 90% of the total water volume), and stir until completely dissolved; pour the aqueous solution into a mixer, and stir at 800 r / min for 4 min; then add the remaining 3.5 parts of water, adjust the speed to 1000 r / min, and stir for 1 min; Slurry testing: The slurry fluidity is controlled at 190mm (tested according to GB / T8077-2012), with no obvious bubbles or stratification, and the fluidity loss is ≤5mm after standing for 5 minutes.

[0031] Pouring and curing (step P3): Casting process: Slowly inject the slurry along the edge of the mold to avoid direct impact on the substrate surface, and completely fill the cavity of the connecting ear; Vibration compaction: Place the mold on a vibration table with an amplitude of 0.5 mm and a frequency of 50 Hz for 25 seconds to remove air bubbles from the slurry. Stop when no obvious air bubbles are observed overflowing from the surface of the slurry. Sealing groove forming: Before the slurry initially sets (30 minutes after pouring, when there is no obvious indentation when pressed with a finger), use a custom arc-shaped tool (2mm radius, 4mm width) to press a sealing groove 104 at the upper edge of the plate. The groove is 2mm deep and 4mm wide, ensuring continuity without any breaks. Standard curing: Move the mold into the standard curing room and cure it for 7 days at 20℃ and 96% relative humidity; during the curing period, check the humidity regularly every day to prevent condensation from forming on the mold surface and dripping onto the slurry surface; Demolding and post-processing: After curing, demold slowly (to avoid breakage of the connecting ear under stress); use a CNC laser cutting machine to process a Φ6mm countersunk hole (countersunk depth 3mm) on the inner surface of the connecting ear to obtain a complete plate 1.

[0032] IV. Key Performance Test Results (Example 2) Performance indicators Detection methods Test results Technical Requirements (This Invention) Total thickness of plate GB / T6342-1996 55mm 50±5mm Protective layer thickness Vernier caliper measurement (multi-point) 5mm 4-6mm Connecting ear thickness Vernier caliper measurement 6.5mm 1.2-1.5 times the thickness of the protective layer Interlayer adhesion GB / T29906-2013 0.38MPa ≥0.3MPa Impact resistance (1kg drop weight, 1m height) GB / T1843-2008 No damage, no cracks No structural damage Flame retardant rating GB8624-2012 A2 grade (non-flammable) ≥A2 level Molten dripping (after 30 seconds of open flame) GB / T8624-2012 No dripping No molten dripping Combustion toxicity (CO release) GB / T20284-2006 420ppm ≤550ppm Thermal conductivity (25℃) GB / T10294-2008 0.031 W / (m·K) ≤0.035W / (m·K) Volumetric water absorption rate (after 24 hours of soaking) GB / T8810-2017 2.8% ≤3.5% Dimensional stability (70℃, 24h) GB / T8811-2019 0.3% ≤0.5% V. Comparison of Examples and Process Adaptation Explanation Formula compatibility: Example 1: The cost is 12% lower than Example 2, and the long-term retention rate of impact strength and flame retardant performance is slightly lower (0.32MPa and 88%, respectively), but it meets the basic requirements for thermal insulation of ordinary buildings; Example 3: Impact strength reaches 0.45MPa, flame retardant performance retention rate is 95% over a long period of time, and thermal conductivity is as low as 0.029W / (m・K), making it suitable for scenarios with extremely high performance requirements. The cost is 18% higher than that of Example 2.

[0033] Key process control points: Substrate foaming: When the steam pressure is below 0.12MPa, AC decomposition is insufficient and the cell density is ≤450 cells / cm³; when it is above 0.15MPa, the cells are prone to rupture and the closed-cell rate drops to below 90%, so 0.13MPa is preferred. The fluidity of the protective layer slurry is as follows: when it is less than 180mm, the slurry cannot completely fill the cavity of the connecting ear; when it is greater than 200mm, the slurry is prone to flow, resulting in uneven thickness of the protective layer. Therefore, it is controlled at 185-195mm. Curing time: If the curing time is less than 6 days, the compressive strength of the protective layer will be ≤28MPa and the interlayer adhesion will be ≤0.25MPa; if the curing time is more than 8 days, the efficiency will decrease and the performance will not be significantly improved, so the curing time is determined to be 7 days.

[0034] Construction compatibility verification: Connecting lugs: Using M5 stainless steel fasteners 2 (compatible with connecting holes), the positioning time for splicing adjacent panels is ≤90s, which is 40% more efficient than traditional splicing methods; Sealing groove: Filled with silicone sealant (modulus 2.0MPa), the sealant layer adheres tightly to the groove, and after 72 hours of water immersion test, there is no water leakage, and the water tightness meets the standard.

[0035] VI. Precautions The nano-graphene sheets in the substrate material need to be stored in a sealed container to avoid moisture absorption and agglomeration. They need to be dried in an 80°C oven for 2 hours before use. After each use, the barrel of the twin-screw extruder must be cleaned with pure HIPS resin to avoid residual flame retardant affecting the next production. During the curing period of the protective layer, violent vibration of the mold is prohibited to prevent micro-cracks from forming at the junction of the connecting lug and the protective layer. Finished boards should be stacked to a height of ≤10 layers when stored, with foam boards placed between each layer to protect the connecting ears from compression and deformation.

[0036] This embodiment verifies the feasibility of the formula and process of the present invention by precisely controlling the specifications of raw materials and process parameters. The prepared flame-retardant graphite polystyrene board meets the design requirements in terms of mechanical properties, flame-retardant safety and construction convenience, and can be industrialized and mass-produced.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A flame-retardant graphite polystyrene board, characterized in that, include: A plate (1) formed by adhering a protective layer (101) to the outside of a substrate (102); The protective layer (101) is provided with connecting ears (103) at each of the four corners. The inner surface of one end of the connecting ear (103) is provided with a connecting hole, and a fastener (2) is screwed into the inner side of the connecting hole. The protective layer (101) is made of the following raw materials in parts by weight: 45-55 parts ordinary silicate cement, 20-24 parts Class II fly ash (F grade), 20-25 parts S95 grade slag powder, 3-4 parts VAE type redispersible latex powder, 3-4 parts acrylic type redispersible latex powder, 0.3-0.5 parts KH-550 silane coupling agent, 0.5-0.9 parts inorganic ceramic fiber, 0.3-0.5 parts organic polypropylene fiber, 0.6-1 parts retarded polycarboxylate-based high-efficiency water-reducing agent, 0.05-0.15 parts sodium gluconate, 0.1-0.3 parts emulsion type silicone defoamer, 3-7 parts industrial grade talc powder, and 30-38 parts clean tap water; The substrate (102) is made from the following raw materials in parts by weight: 75-85 parts high-impact polystyrene, 15-25 parts styrene-maleic anhydride copolymer, 10-14 parts expandable graphite, 9-11 parts microencapsulated ammonium polyphosphate, 5-7 parts melamine cyanurate, 1-3 parts zinc borate, 1-3 parts nano silica, 1-2 parts silicon carbide, 1-2 parts nano graphene sheets, 4-6 parts chemical foaming agent azodicarbonamide, 2-3 parts nucleating agent talc, 0.6-1 part KH-550 silane coupling agent, 0.8-1.2 parts polytetrafluoroethylene, 1-2 parts lubricant / dispersant, 0.2-0.4 parts antioxidant, 0.1-0.3 parts ultraviolet absorber, 0.8-1.2 parts smoke suppressant ammonium molybdate, and 0.4-0.6 parts antistatic agent.

2. The flame-retardant graphite polystyrene board according to claim 1, characterized in that: The four connecting ears (103) are evenly distributed in the clockwise direction, and the connecting ears (103) corresponding to the four plates (1) can be stacked in sequence vertically upward.

3. The flame-retardant graphite polystyrene board according to claim 1, characterized in that: The protective layer (101) has a sealing groove (104) at the corner of its upper end, and the sealing groove (104) has an arc-shaped cross-section with a depth of 1.5-2.5 mm and a width of 3-5 mm.

4. The flame-retardant graphite polystyrene board according to claim 1, characterized in that: The connecting ear (103) and the protective layer (101) are integrally cast structures, and the thickness of the connecting ear (103) is 1.2-1.5 times the thickness of the protective layer (101).

5. A flame-retardant graphite polystyrene board according to claim 1, characterized in that: The inorganic ceramic fiber has a length of 3-6 mm, and the organic polypropylene fiber has a length of 9-12 mm.

6. The flame-retardant graphite polystyrene board according to claim 1, characterized in that: The styrene-maleic anhydride copolymer in the substrate (102) raw material has a maleic anhydride content of 8-12 wt%.

7. The flame-retardant graphite polystyrene board and its preparation method according to claim 1, characterized in that: The nano-graphene sheets in the substrate (102) material are functionalized graphene that has been modified by hydroxylation, with a sheet diameter of 5-15 μm and a thickness of 1-5 nm.

8. A method for preparing a flame-retardant graphite polystyrene board as described in any one of claims 1-7, characterized in that, The process includes the preparation of a substrate (102), the preparation of a protective layer (101), and a composite step. The preparation of the substrate (102) includes the following steps: S1. Premix: High-impact polystyrene, styrene-maleic anhydride copolymer, nucleating agent talc, lubricant / dispersant, antioxidant, ultraviolet absorber, antistatic agent and polytetrafluoroethylene are added to a high-speed mixer and mixed at 60-75℃ for 5-8 minutes to obtain premix A; S2. Flame retardant system mixing: Expandable graphite, microencapsulated ammonium polyphosphate, melamine cyanurate, zinc borate, nano silica, silicon carbide, nano graphene sheets, smoke suppressant ammonium molybdate, and KH-550 silane coupling agent are mixed evenly at low speed at room temperature to obtain flame retardant composite powder B. S3. Final mixing and foaming: Premix A, flame retardant composite powder B and chemical foaming agent azodicarbonamide are added to a twin-screw extruder, and the mixture is melt-blended, extruded, water-cooled and pelletized to obtain foaming masterbatch. The masterbatch is then injected into a mold and foamed at a steam pressure of 0.12-0.15MPa and a temperature of 115-125℃. After holding the pressure and cooling, the mixture is demolded to obtain the substrate (102).

9. The flame-retardant graphite polystyrene board and its preparation method according to claim 8, characterized in that: The steps of preparing the protective layer (101) and bonding it with the substrate (102) include: P1. Mold preparation: Place the demolded substrate (102) into the molding mold, wherein the mold has cavities for molding connecting ears (103) at the four corners corresponding to the substrate (102); P2. Slurry preparation: Dry mix ordinary silicate cement, Class F II fly ash, S95 grade slag powder, and industrial grade talc powder for 1-2 minutes; Add VAE-type and acrylic-type redispersible latex powder, KH-550 silane coupling agent, inorganic ceramic fiber, organic polypropylene fiber, and sodium gluconate, and continue dry mixing for 2-3 minutes; Dissolve the retarded polycarboxylate superplasticizer and emulsion silicone defoamer in some clean tap water, pour them into the mixture and stir for 3-5 minutes, then add the remaining water and stir until a uniform slurry with good flowability is obtained. P3. Pouring and curing: The slurry is poured into the mold in which the substrate (102) has been placed, filling the cavity of the connecting ear (103). After being vibrated and compacted, the surface is smoothed and a sealing groove (104) is opened, and then cured for 7 days at a temperature of 20±2℃ and a relative humidity of ≥95%. After demolding, the board body (1) is obtained.

10. A building exterior wall insulation system, characterized in that: The flame-retardant graphite polystyrene board as described in any one of claims 1-7 is used as the insulation layer. Adjacent boards (1) are connected to each other by fasteners (2) passing through the connecting lugs (103), and the sealing grooves (104) at the joints between the boards (1) are filled with sealant.

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