Enhanced connection composite insulation board and construction method of external wall thermal insulation system thereof

Abstract

This invention discloses a construction method for an enhanced composite insulation board and its external wall insulation system, belonging to the technical field of building insulation materials. The insulation board adopts a five-layer symmetrical structure: "outer crack-resistant layer - first adhesive layer - insulation layer - second adhesive layer - inner crack-resistant layer," using rock wool strips as the insulation layer and rigid crack-resistant layers on both the inner and outer sides. Stable bonding and composite bonding of each layer is achieved through a modified polyurethane adhesive. This invention synthesizes a modified DOPO with both phosphorus-phenanthroline flame-retardant groups and dicarboxyl interfacial anchoring groups through molecular design. The adhesive prepared using this modifier achieves a synergistic improvement in intrinsic flame retardancy and high-strength bonding, fundamentally solving the core performance shortcomings of traditional adhesives. The accompanying cast-in-place construction method allows for one-time casting and permanent rigid anchoring of the insulation board to the main building structure, significantly improving the fire safety, structural durability, and construction efficiency of the insulation system, and is widely applicable to various building external wall insulation projects.

Description

Technical Field

[0001] This invention relates to the field of building insulation materials technology, and in particular to a construction method for an enhanced connection composite insulation board and its external wall insulation system. Background Technology

[0002] With the continuous deepening of my country's building energy conservation policies and the continuous improvement of building energy conservation design standards, some regions have fully implemented the construction requirements for ultra-low energy consumption and near-zero energy consumption buildings. The thermal insulation performance of building envelopes has become a core control link in achieving building energy conservation goals. External wall insulation systems, with their advantages of high insulation efficiency, no occupation of indoor space, and protection of the main structure, have long been the mainstream technical solution for energy-saving exterior wall projects in civil and public buildings in my country. Under the development trend of building industrialization and green construction, the integrated insulation and structural formwork technology, with its characteristics of simultaneous completion of main structure construction and insulation layer installation, significantly shortening the construction period, and reducing high-altitude operations, has become an important development direction for external wall insulation technology. However, in practical engineering applications, composite insulation boards adapted to the non-removable casting process always face industry pain points such as difficulty in simultaneously addressing fire safety, interface adhesion durability, structural stability, and construction adaptability, which seriously restricts the large-scale promotion and application of integrated insulation and structural technology. Currently, the most widely used exterior wall insulation system in building construction is still the traditional thin-plaster exterior wall insulation system. This system employs a two-stage construction process, where the main building structure is poured first, followed by the application of the insulation layer. This process has inherent drawbacks that are difficult to overcome. The construction procedures are complex, involving a large amount of wet work on-site. This not only significantly extends the overall construction period but is also highly susceptible to the influence of the on-site construction environment and the skill level of the workers. It is difficult to achieve uniform and stable control over the bonding quality and surface flatness of the insulation boards, resulting in significant variations in project quality. Meanwhile, this system involves a high proportion of high-altitude operations, posing significant safety risks during construction. More importantly, the insulation layer is connected to the main structure solely through a "point-bonding + subsequent anchor bolt" method, resulting in limited interfacial bonding. Under long-term hot and cold cycles, alternating wet and dry conditions, and UV aging, the bonding layer is prone to performance degradation and failure, leading to hollowing, cracking, or even large-scale detachment of the insulation layer. The numerous safety accidents involving the detachment of external wall insulation layers in China in recent years have fully exposed the fatal flaws of this system in terms of long-term service safety, and it also fails to meet the design requirement that the insulation system and the main building structure have the same service life. To address the shortcomings of traditional secondary construction processes, the industry has gradually developed various no-removal formwork composite insulation board products. However, existing products have significant weaknesses in core performance, particularly the adhesive layer material, which is the core structure of the composite board and a key bottleneck restricting product performance. Rock wool, as a Class A non-combustible insulation core material, is the mainstream core material choice for no-removal insulation boards. However, its bonding effect with the inner and outer rigid surface layers depends entirely on the performance of the adhesive. Existing composite insulation boards mostly use ordinary polyurethane adhesives, which are inherently flammable and have poor fire resistance, making it difficult to meet the stringent requirements of building fire codes. Conventional flame-retardant modification schemes often use physical blending to add flame retardants, which not only leads to the migration, precipitation, and loss of flame retardants during long-term use, causing irreversible degradation of fire resistance, but also damages the cohesive strength and bonding performance of the adhesive itself, resulting in a technical contradiction of "improved flame retardancy but decreased bonding performance." Even though some solutions employ chemical copolymerization for flame retardant modification, they only focus on improving the flame retardant properties of polyurethane, neglecting the interfacial compatibility of adhesives with porous rock wool fibers and calcium silicate / cement inorganic boards. Ordinary polyurethane adhesives have high surface tension and poor wettability with inorganic substrates, making it impossible to form a strong bond with them. This easily leads to interfacial debonding and interlayer separation. At the same time, they have poor resistance to damp heat aging and freeze-thaw cycles. In complex outdoor service environments, their bonding performance deteriorates rapidly, making it impossible to guarantee the structural integrity of the composite insulation board throughout its entire life cycle. In addition, existing non-removable composite insulation boards also have significant defects in structural design and supporting construction systems. Most products do not form a symmetrical rigid protective structure, but only have a rigid surface layer on one side. When temperature and humidity change, the shrinkage and expansion stress on both sides of the board cannot be balanced, which easily leads to problems such as board warping and interlayer debonding. At the same time, they are also unable to withstand the lateral pressure and vibration load during the pouring of cast-in-place concrete. During construction, problems such as pressure damage, displacement, and grout leakage of the rock wool core material are prone to occur. The supporting anchoring connection system is not well designed and cannot achieve rigid permanent anchoring between the insulation board and the cast-in-place concrete main structure. Even if the one-time pouring is completed, it is difficult to guarantee the connection safety during long-term service, and there is still a risk of insulation layer detachment. At the same time, the joint treatment and joint waterproofing and crack resistance design of existing products are not perfect. After on-site installation, common engineering problems such as joint leakage, thermal bridging effect, and later cracking are prone to occur. A lot of on-site secondary treatment procedures are still required. It does not truly achieve the integration of insulation and structural construction and cannot meet the comprehensive requirements of modern buildings for the safety, durability, and efficient construction of insulation systems. In summary, existing external wall insulation technologies, whether traditional secondary construction systems or existing non-removable composite insulation systems, all have technical bottlenecks that are difficult to resolve in a coordinated manner in terms of fire safety, interface adhesion, structural stability, and engineering adaptability. They cannot meet the comprehensive requirements of current building energy conservation, fire protection codes, and long-term safe service of engineering projects. There is an urgent need to develop a reinforced composite insulation board and supporting construction methods that combine intrinsic high flame retardancy, high-strength interface adhesion, structural stability, and compatibility with cast-in-place integrated construction. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a construction method for an enhanced connection composite insulation board and its external wall insulation system.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a reinforced composite insulation board, comprising, from the outside to the inside, an outer crack-resistant layer, a first adhesive layer, an insulation layer, a second adhesive layer, and an inner crack-resistant layer.

[0005] Preferably, the outer crack-resistant layer and the inner crack-resistant layer are made of rigid boards; the rigid boards include fiber-reinforced calcium silicate boards or cement boards. It should be noted that the outer crack-resistant layer and the inner crack-resistant layer can also be made of rigid boards of other materials.

[0006] More preferably, the rigid board is a fiber-reinforced calcium silicate board with a thickness of 5 mm.

[0007] Preferably, the first adhesive layer and the second adhesive layer are made of modified polyurethane adhesive.

[0008] Preferably, the insulation layer is made of rock wool strips.

[0009] Preferably, the preparation method of the modified polyurethane adhesive includes the following steps: Step S01: Under nitrogen protection, DOPO and triphenylphosphine are added to a toluene / tetrahydrofuran mixed solvent, heated to 60-70℃ and stirred until dissolved. Then, 3-hydroxy-2,5-furandione is added in portions over 1 hour. After the addition is complete, the temperature is raised to 90-100℃ and the reaction is maintained for 8-12 hours. After cooling to room temperature, the mixture is filtered. The filter cake is washed three times with a tetrahydrofuran / ethanol mixed solvent and then dried to obtain intermediate A. The chemical reaction equation is as follows: ; Step S02: Under nitrogen protection, intermediate A and epichlorohydrin are added to anhydrous acetonitrile and stirred until completely dissolved. Anhydrous potassium carbonate is then added, and the mixture is heated to 65-75°C and reacted in the dark for 10-12 hours. After the reaction is complete, the mixture is cooled to room temperature, filtered, and the filtrate is distilled under reduced pressure to remove epichlorohydrin and solvent, yielding intermediate B. The chemical reaction equation is as follows: ; Step S03: Under nitrogen protection, intermediate B is added to anhydrous dichloromethane and stirred until dissolved. Then, 1,7-bis-BOC-1,4,7-triazaheptane is added, the temperature is raised to 30-40°C, and the reaction is stirred for 3-6 hours. After cooling to room temperature, the solvent is removed by vacuum distillation to obtain intermediate C, which can be directly proceeded to the next step without purification. The chemical reaction equation is as follows: ; Step S04: Under nitrogen protection, intermediate C is added to anhydrous dichloromethane and stirred until homogeneous. Trifluoroacetic acid is added dropwise at room temperature over 30-60 minutes. After the addition is complete, the mixture is stirred at room temperature for 4-6 hours. After filtration, the filter cake is added to deionized water and heated to 40-45°C with stirring for 2-3 hours. The temperature is then lowered to 0-5°C, and the pH of the system is adjusted to 5-5.5 with sodium hydroxide aqueous solution. At this point, a large amount of solid precipitates out. After standing for 30 minutes, the mixture is filtered. The filter cake is washed and dried to obtain modified DOPO. The chemical reaction equation is as follows: ; Step S05: Under nitrogen protection, polypropylene glycol and 4,4'-diphenylmethane diisocyanate are added to a reaction vessel and heated to 70-80℃ with stirring. The reaction is maintained at this temperature for 2-3 hours, with periodic sampling during the process. The isocyanate group content in the system is determined using the di-n-butylamine method. When the isocyanate group content reaches the theoretically calculated value, the temperature is lowered to 15-20℃. Modified DOPO is dissolved in anhydrous ethyl acetate and added dropwise to the system over a period of 30-60 minutes. After the addition is complete, the system is brought back to room temperature and stirred for 0.5-1.5 hours. Anhydrous ethyl acetate is added to adjust the solid content of the system to 30-40%. Then, defoamer and rheology modifier are added, and the mixture is stirred evenly. The mixture is then degassed under vacuum to obtain the modified polyurethane adhesive.

[0010] Preferably, in step S01, the molar ratio of DOPO, triphenylphosphine, and 3-hydroxy-2,5-furandione is 1:0.01-0.015:1-1.1.

[0011] Preferably, in step S01, the DOPO and toluene / tetrahydrofuran mixed solvent are in a weight ratio of 1:5-10.

[0012] Preferably, in step S01, the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran mixed solvent is 1:1.

[0013] Preferably, in step S01, the volume ratio of tetrahydrofuran to ethanol in the tetrahydrofuran / ethanol mixed solvent is 1:1.

[0014] Preferably, in step S02, the molar ratio of intermediate A, epichlorohydrin, and anhydrous potassium carbonate is 1:1.5-2.5:2-3.

[0015] Preferably, in step S02, intermediate A and anhydrous acetonitrile are in a weight ratio of 1:4-10.

[0016] Preferably, in step S03, the molar ratio of intermediate B and 1,7-bis-BOC-1,4,7-triazaheptane is 1:1.1-1.2.

[0017] Preferably, in step S03, intermediate B and anhydrous dichloromethane are in a weight ratio of 1:8-12.

[0018] Preferably, in step S04, the molar ratio of intermediate C to trifluoroacetic acid is 1:3-5.

[0019] Preferably, in step S04, the intermediate C, anhydrous dichloromethane, and deionized water are in a weight ratio of 1:10-15:5-10.

[0020] Preferably, the concentration of the sodium hydroxide aqueous solution in step S04 is 5-15 wt%.

[0021] Preferably, in step S05, the weight ratio of polypropylene glycol, 4,4'-diphenylmethane diisocyanate, modified DOPO, defoamer, and rheology modifier is 60-70:15-20:12-20:0.5-1:0.3-0.8.

[0022] Preferably, the number-average molecular weight of the polypropylene glycol in step S05 is 2000.

[0023] Preferably, the defoamer in step S05 refers to BYK-066N.

[0024] Preferably, the rheology modifier in step S05 refers to BYK-410.

[0025] Preferably, in step S05, periodic sampling refers to taking a sample of the reaction system every 20-30 minutes during the heat preservation reaction, and determining the isocyanate group content using the di-n-butylamine titration method.

[0026] Preferably, the theoretical calculation value of the isocyanate group content in step S05 refers to the mass fraction of the remaining isocyanate groups in the system after the reaction is complete, calculated based on the molar ratio of polypropylene glycol to 4,4'-diphenylmethane diisocyanate and the stoichiometric ratio of hydroxyl to isocyanate groups of 1:1.

[0027] Furthermore, the present invention also provides a method for preparing a reinforced composite insulation board, comprising the following steps: S1. Cut the rock wool strips to the design size, clean the surface of dust, loose fibers and debris, and ensure that the bonding surface is clean and dry to obtain the insulation layer; S2. Cut the rigid boards used for the outer crack-resistant layer and the inner crack-resistant layer to the design size, clean the dust, oil stains and release agent residue on the surfaces of the boards to be bonded, and ensure that the board surfaces are clean and dry; S3. Apply a 1mm thick modified polyurethane adhesive evenly to the inner side of the outer crack-resistant layer to form the first adhesive layer. Lay the insulation layer flat on the first adhesive layer and press lightly to ensure full adhesion. Then apply a 1mm thick modified polyurethane adhesive evenly to the other side of the insulation layer to form the second adhesive layer. Lay the inner crack-resistant layer flat on the second adhesive layer and align the four sides to obtain the laminated board. S4. After letting the laminated boards stand at room temperature for 20-40 minutes, they are sent to a flatbed cold press and pressed at 0.3-0.5MPa for 15-25 minutes. After depressurization, the boards are sent to an oven and treated at 65-75℃ in a forced ventilation environment for 40-60 minutes. Then, they are cured in an environment of 15-25℃ and relative humidity ≥50% for 7 days. After trimming, shaping, and tongue and groove jointing, the reinforced composite insulation board is obtained.

[0028] Preferably, the design dimensions are any one of the following: width 300mm, 400mm, 600mm, 800mm, 900mm or 1200mm, and height 2800mm-3000mm.

[0029] More preferably, the design dimensions are 600mm in width and 2800mm in height.

[0030] Preferably, in S4, forced ventilation refers to an air velocity of 0.6-1.2 m / s inside the oven.

[0031] Furthermore, the present invention also provides a construction method for an external wall insulation system with reinforced composite insulation boards, comprising the following steps: a. Pre-construction preparation: Complete the reinforcement binding of the external shear walls, beams and columns. After acceptance, bind cement mortar protective layer limiting blocks on the outside of the reinforcement, with a block density of no less than 4 blocks / m². 2 Based on the building axis, mark the wall edge lines, formwork control lines, and insulation board installation positioning lines; b. Insulation board installation: According to the prefabricated layout drawing, install the reinforced composite insulation boards in the order of first the corner panels and then the main wall panels. Adjacent insulation boards are spliced ​​by interlocking tongue and groove joints, with sealant pre-filled inside the tongue and groove joints. The joint width after splicing is ≤3mm. After positioning, use binding steel wire to fix the insulation board to the wall reinforcement, ensuring that the verticality deviation of the board surface is ≤3mm / m. c. System connector installation: Drill holes in the insulation board at the preset points, hammer in the system connectors, and ensure that the effective length of the end of the system connector anchored into the cast-in-place concrete is ≥100mm. The number of system connectors installed per square meter shall not be less than 8, and they shall be evenly arranged in a quincunx pattern. The spacing between adjacent connectors shall be ≤400mm. Additional system connectors shall be installed within 200mm around the door and window openings. After installation, the inner end of the system connector shall be firmly tied to the wall reinforcement. d. Template system installation: Install the inner wall template and matching support brackets, and install through-wall tie bolts at the corresponding positions. Use water-stop bolts with water-stop plates for the waterproof parts of the outer wall. The bolt holes should avoid the joints of the insulation board and be ≥50mm away from the edge of the board joint. Install the main and secondary ribs of the template, and tighten them after correcting the verticality and flatness of the board surface and the design thickness of the wall. e. Concrete pouring and curing: Concrete with a slump of 160±20mm shall be poured in layers continuously, with each layer height ≤500mm. An immersion vibrator shall be used for compaction. During the compaction process, the vibrator shall not be allowed to directly contact the reinforced composite insulation board, system connectors and formwork. After pouring, the concrete shall be kept moist and cured in accordance with the specifications. f. Formwork Removal and Joint Treatment: After the concrete reaches the design demolding strength, remove the inner formwork, main and secondary ribs, and support system; fill and level the joints of the insulation boards with polymer crack-resistant mortar, and lay alkali-resistant fiberglass mesh with a width of ≥300mm at the joints for crack resistance reinforcement; waterproof and seal the corners, door and window openings, tie bolt holes, and reserved holes for crack resistance reinforcement. g. Finishing layer construction: According to the exterior facade design requirements, complete the construction of the leveling layer, crack-resistant layer and finishing layer, and complete the construction of the external wall insulation system with reinforced connection composite insulation board.

[0032] Preferably, the main rod of the system connector in c is an HRB400 grade 8mm diameter threaded steel bar, with an anti-corrosion anchor plate of ≥60mm diameter at the outer end. The rod body passing through the insulation board and the outer side of the anchor plate are wrapped with engineering plastic hot melt anti-corrosion coating. The tensile bearing capacity and pull-out force of a single connector are both ≥0.60kN.

[0033] Preferably, the working mechanism of the reinforced connection composite insulation board of the present invention is explained as follows: The core performance of this composite insulation board stems from the modified polyurethane adhesive. Through molecular structure design, a functional monomer integrating DOPO phosphaphenanthrene flame-retardant groups, bis-primary amino chain-extending reaction sites, and bis-carboxyl interfacial anchoring groups was synthesized. This monomer, acting as a diamine chain extender, permanently embeds itself into the polyurethane molecular backbone through covalent bonding in a reaction with isocyanate. This is completely different from physically added flame retardants, fundamentally eliminating the problems of flame-retardant group migration, precipitation, and loss, achieving complete synchronization between flame-retardant effect and adhesive lifespan. The phosphaphenanthrene groups possess a dual-effect flame-retardant mechanism in both the gas and condensed phases. At high temperatures, they can decompose in the gas phase to generate phosphorus-oxygen free radicals, capturing active intermediates in the combustion chain reaction to interrupt the combustion process. Simultaneously, they can promote the rapid formation of a dense and stable char layer in the condensed phase, isolating heat and oxygen transfer, and inhibiting the generation of smoke and molten droplets. Combined with the fire-retardant properties of the rock wool core material, this ensures the fire safety of the composite insulation board throughout its entire lifespan. Meanwhile, the highly polar dicarboxyl groups in the monomer molecules can significantly reduce the surface tension of the adhesive system and improve its wettability to the rough interfaces of rock wool porous fibers and calcium silicate boards / cement boards. It can penetrate into the pores of rock wool fiber bundles and inorganic boards to form mechanical anchoring, and can also form strong hydrogen bonds and chelate chemical bonds with the silanol groups and calcium ions on the surface of inorganic substrates. This completely solves the problems of weak interfacial bonding, easy debonding, and poor resistance to humid heat aging of ordinary polyurethane adhesives to inorganic substrates. The highly polar urea bonds generated by the reaction of amino groups and isocyanates can form a strong intermolecular hydrogen bond network, which can significantly improve the cohesive strength and flexibility of the adhesive itself. This can ensure the long-term stability of interlayer bonding and alleviate the stress deformation caused by the difference in thermal expansion coefficients between different materials, avoiding interlayer cracking and delamination after thermal cycling.

[0034] This invention employs a five-layer symmetrical composite structure consisting of an outer crack-resistant layer, a first adhesive layer, a rock wool insulation layer, a second adhesive layer, and an inner crack-resistant layer, achieving integrated functional layering and structural reinforcement protection. The fiber-reinforced calcium silicate board or cement board on both the inner and outer sides provides double-sided rigid protection for the central rock wool insulation core material. This enhances the overall impact resistance, crack resistance, and dimensional stability of the board, while also achieving dual-purpose functionality. The inner rigid board can be directly used as a permanent, non-removable external formwork for cast-in-place concrete, bearing the lateral pressure and vibration loads during concrete pouring, preventing pressure damage and displacement of the rock wool core material. The outer rigid board can be directly used as a crack-resistant protective base layer for external wall insulation, eliminating the need for on-site plastering of the exterior wall and significantly simplifying the on-site construction process. The symmetrical double-rigid-layer design effectively balances the shrinkage and expansion stresses caused by changes in environmental temperature and humidity on both the inner and outer sides of the board, fundamentally avoiding board warping and interlayer debonding problems that are common with single-sided rigid layers. The modified polyurethane adhesive bonding layers on both the top and bottom sides achieve high-strength and aging-resistant bonding between the rigid surface layer and the rock wool insulation layer, eliminating interface gaps and weak bonding areas between different materials, ensuring the structural integrity of the composite board throughout the entire process of industrial production, transportation, and on-site installation, and adapting to the complex application conditions of building engineering.

[0035] The composite insulation board of this invention, through a matching anchoring system and cast-in-place construction method, ultimately achieves integrated molding and service life of the insulation system and the main building structure. The matching system connector has one end tightly bonded to the outer rigid layer of the insulation board via an anchoring plate, while the other end's threaded steel bar is directly anchored into the cast-in-place concrete wall and firmly tied to the main structural steel reinforcement. This creates a permanent rigid connection between the composite insulation board and the concrete structure, completely different from the traditional "point bonding + later anchor bolt fixing" method of external wall insulation, fundamentally eliminating the major safety hazard of insulation layer detachment. Simultaneously, the tongue-and-groove design on the side of the composite insulation board, combined with sealant filling and crack-resistant reinforcement at the joints, ensures accurate positioning during on-site installation and forms a fitted, sealed structure, blocking the thermal bridging effect and the path of rainwater and moisture penetration at the joints, solving the common engineering problems of leakage and cracking at the joints of traditional insulation boards. The entire system is formed by casting together with the shear wall of the main building in one go, which completely changes the traditional secondary construction mode of external wall insulation. It significantly shortens the total construction period of the building project, reduces the safety risks of high-altitude operations, and ultimately forms an external wall insulation system that integrates thermal insulation, fire safety, structural non-dismantling, and long-term durability, achieving the same service life as the main building structure.

[0036] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, through molecular structure design, achieves a synergistic improvement in the intrinsic flame retardancy and interfacial adhesion properties of polyurethane adhesives, solving the industry pain point of mutual constraint between flame retardant modification and adhesion performance in traditional polyurethane adhesives. By covalently embedding phosphaphenanthrene flame retardant groups into the polyurethane molecular backbone, the problems of flame retardant migration, precipitation, and loss are eliminated, ensuring long-term fire resistance stability. The dicarboxylic acid anchoring groups significantly improve the adhesive's wettability and bonding strength to inorganic substrates, achieving high-strength and stable adhesion between various structural layers.

[0037] 2. This invention employs a five-layer symmetrical composite structure design, providing double-sided rigid protection for the rock wool insulation core material. This effectively balances the shrinkage and expansion stresses caused by temperature and humidity changes on both sides of the board, preventing board warping and interlayer debonding from the structural source. Simultaneously, the inner rigid layer can be directly used as a permanent, non-removable external formwork for cast-in-place concrete, capable of withstanding lateral pressure and vibration loads during pouring. The outer rigid layer can be directly used as a crack-resistant protective base layer for the insulation system, significantly simplifying on-site construction procedures.

[0038] 3. The rigid anchoring system and cast-in-place integrated construction method of this invention achieve one-time casting and permanent rigid connection between the insulation board and the main building structure, fundamentally solving the major safety hazards of hollowing and detachment of the insulation layer in traditional external wall insulation systems. Combined with the tongue-and-groove splicing design of the boards, it effectively blocks the thermal bridging effect and rainwater penetration path at the joints, avoiding common engineering problems such as cracking and leakage later on, and achieving the same service life as the main building structure.

[0039] 4. This invention comprehensively addresses the core requirements of building exterior wall insulation, including fire safety, thermal insulation, structural durability, and efficient construction. It overcomes the performance bottlenecks of existing non-removable composite insulation boards, and all performance indicators meet the stringent requirements of current building energy conservation and fire protection codes. The product is manufactured using industrial prefabrication, resulting in uniform and stable finished product quality. On-site installation is simple, significantly shortening the construction period and reducing overall project costs. It possesses excellent application value in various building exterior wall insulation projects. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the reinforced connection composite insulation board proposed in this invention; Figure 2 The modified DOPO prepared in Example 2 of this invention 1 H NMR spectrum. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0042] Preparation Example 1: A specific preparation method for modified polyurethane adhesive, including the following steps: Step S01: Under nitrogen protection, 1 mol (216.18 g) of DOPO and 0.01 mol of triphenylphosphine were added to 1080.9 g of toluene / tetrahydrofuran mixed solvent (toluene and tetrahydrofuran volume ratio of 1:1). The mixture was heated to 60 °C and stirred until dissolved. Then, 1 mol of 3-hydroxy-2,5-furandione was added in portions over 1 hour. After the addition was complete, the mixture was heated to 90 °C and kept at that temperature for 8 hours. After cooling to room temperature, the mixture was filtered. The filter cake was washed three times with tetrahydrofuran / ethanol mixed solvent (tetrahydrofuran and ethanol volume ratio of 1:1) and then dried to obtain intermediate A. Step S02: Under nitrogen protection, 1 mol (330.23 g) of intermediate A and 1.5 mol of epichlorohydrin were added to 1320.92 g of anhydrous acetonitrile and stirred until completely dissolved. Then, 1.5 mol of anhydrous potassium carbonate was added, and the temperature was raised to 65°C. The reaction was carried out in the dark for 10 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filtrate was distilled under reduced pressure to remove epichlorohydrin and solvent, yielding intermediate B. Step S03: Under nitrogen protection, 1 mol (386.3 g) of intermediate B was added to 3090.4 g of anhydrous dichloromethane and stirred until dissolved. Then, 1.1 mol of 1,7-bis-BOC-1,4,7-triazaheptane was added, the temperature was raised to 30 °C, and the reaction was stirred for 3 h. After cooling to room temperature, the solvent was removed by vacuum distillation to obtain intermediate C, which can be directly proceeded to the next step without purification. Step S04: Under nitrogen protection, 1 mol (689.7 g) of intermediate C was added to 6897 g of anhydrous dichloromethane and stirred until homogeneous. 3 mol of trifluoroacetic acid was added dropwise at room temperature over 30 min. After the addition was complete, the mixture was stirred at room temperature for 4 h. After filtration, the filter cake was added to 3448.5 g of deionized water and heated to 40 °C for 2 h with stirring. The temperature was then lowered to 0-5 °C, and the pH of the system was adjusted to 5-5.5 with a 5 wt% sodium hydroxide aqueous solution. At this point, a large amount of solid precipitated out. After standing for 30 min, the mixture was filtered. The filter cake was washed and dried to obtain modified DOPO. Step S05: Under nitrogen protection, 600g of polypropylene glycol (number average molecular weight 2000) and 150g of 4,4'-diphenylmethane diisocyanate were added to a reaction vessel. The mixture was heated to 70℃ with stirring and kept at this temperature for 2 hours. Samples were taken every 20 minutes during the reaction. The isocyanate group content in the system was determined using the di-n-butylamine method. When the isocyanate group content reached the theoretically calculated value, the temperature was lowered to 15-20℃. 120g of modified DOPO was dissolved in anhydrous ethyl acetate and added dropwise to the system over a period of 30 minutes. After the addition was complete, the mixture was brought back to room temperature and stirred for 0.5 hours. Anhydrous ethyl acetate was added to adjust the solid content of the system to 30-40%. Then, 5g of BYK-066N and 3g of BYK-410 were added. After stirring evenly, the mixture was degassed under vacuum to obtain the modified polyurethane adhesive.

[0043] Preparation Example 2: A specific preparation method for modified polyurethane adhesive, including the following steps: Step S01: Under nitrogen protection, 1 mol (216.18 g) of DOPO and 0.012 mol of triphenylphosphine were added to 1.8 kg of toluene / tetrahydrofuran mixed solvent (toluene and tetrahydrofuran volume ratio of 1:1). The mixture was heated to 65 °C and stirred until dissolved. Then, 1.05 mol of 3-hydroxy-2,5-furandione was added in portions over 1 hour. After the addition was complete, the mixture was heated to 95 °C and kept at that temperature for 10 hours. After cooling to room temperature, the mixture was filtered. The filter cake was washed three times with tetrahydrofuran / ethanol mixed solvent (tetrahydrofuran and ethanol volume ratio of 1:1) and then dried to obtain intermediate A. Step S02: Under nitrogen protection, 1 mol (330.23 g) of intermediate A and 2 mol of epichlorohydrin were added to 2 kg of anhydrous acetonitrile and stirred until completely dissolved. Then, 2.5 mol of anhydrous potassium carbonate was added, and the temperature was raised to 70°C. The reaction was carried out in the dark for 11 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filtrate was distilled under reduced pressure to remove epichlorohydrin and solvent, yielding intermediate B. Step S03: Under nitrogen protection, 1 mol (386.3 g) of intermediate B was added to 3.9 kg of anhydrous dichloromethane and stirred until dissolved. Then, 1.15 mol of 1,7-bis-BOC-1,4,7-triazaheptane was added, the temperature was raised to 35 °C, and the reaction was stirred for 4 h. After cooling to room temperature, the solvent was removed by vacuum distillation to obtain intermediate C, which can be directly proceeded to the next step without purification. Step S04: Under nitrogen protection, 1 mol (689.7 g) of intermediate C was added to 8.3 kg of anhydrous dichloromethane and stirred until homogeneous. 4 mol of trifluoroacetic acid was added dropwise at room temperature over 45 min. After the addition was complete, the mixture was stirred at room temperature for 5 h. After filtration, the filter cake was added to 5.5 kg of deionized water, and the mixture was heated to 42 °C and reacted for 2.5 h with stirring. The temperature was then lowered to 0-5 °C, and the pH of the system was adjusted to 5-5.5 with a 10 wt% sodium hydroxide aqueous solution. At this point, a large amount of solid precipitated out. After standing for 30 min, the mixture was filtered. The filter cake was washed and dried to obtain modified DOPO. The product was then processed... 1 Characterization was performed using 1H NMR, and the characterization spectra are as follows: Figure 2 As shown; Step S05: Under nitrogen protection, 650g of polypropylene glycol (number average molecular weight 2000) and 180g of 4,4'-diphenylmethane diisocyanate were added to a reaction vessel. The mixture was heated to 75℃ with stirring and kept at this temperature for 2.5h. Samples were taken every 25min during the reaction. The isocyanate group content in the system was determined using the di-n-butylamine method. When the isocyanate group content reached the theoretically calculated value, the temperature was lowered to 15-20℃. 160g of modified DOPO was dissolved in anhydrous ethyl acetate and added dropwise to the system over a period of 45min. After the addition was complete, the mixture was brought back to room temperature and stirred for 1h. Anhydrous ethyl acetate was added to adjust the solid content of the system to 30-40%. Then, 8g of BYK-066N and 5g of BYK-410 were added. After stirring evenly, the mixture was degassed under vacuum to obtain the modified polyurethane adhesive.

[0044] Preparation Example 3: A specific preparation method for modified polyurethane adhesive, including the following steps: Step S01: Under nitrogen protection, 1 mol (216.18 g) of DOPO and 0.015 mol of triphenylphosphine were added to 2161.8 g of toluene / tetrahydrofuran mixed solvent (toluene and tetrahydrofuran volume ratio of 1:1). The mixture was heated to 70 °C and stirred until dissolved. Then, 1.1 mol of 3-hydroxy-2,5-furandione was added in portions over 1 hour. After the addition was complete, the mixture was heated to 100 °C and kept at that temperature for 12 hours. After cooling to room temperature, the mixture was filtered. The filter cake was washed three times with tetrahydrofuran / ethanol mixed solvent (tetrahydrofuran and ethanol volume ratio of 1:1) and then dried to obtain intermediate A. Step S02: Under nitrogen protection, 1 mol (330.23 g) of intermediate A and 2.5 mol of epichlorohydrin were added to 3302.3 g of anhydrous acetonitrile and stirred until completely dissolved. Then, 3 mol of anhydrous potassium carbonate was added, and the temperature was raised to 75°C. The reaction was carried out in the dark for 12 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filtrate was distilled under reduced pressure to remove epichlorohydrin and solvent, yielding intermediate B. Step S03: Under nitrogen protection, 1 mol (386.3 g) of intermediate B was added to 4635.6 g of anhydrous dichloromethane and stirred until dissolved. Then, 1.2 mol of 1,7-bis-BOC-1,4,7-triazaheptane was added, the temperature was raised to 40 °C, and the reaction was stirred for 6 h. After cooling to room temperature, the solvent was removed by vacuum distillation to obtain intermediate C, which can be directly proceeded to the next step without purification. Step S04: Under nitrogen protection, 1 mol (689.7 g) of intermediate C was added to 10345.5 g of anhydrous dichloromethane and stirred until homogeneous. 5 mol of trifluoroacetic acid was added dropwise at room temperature over 60 min. After the addition was complete, the mixture was stirred at room temperature for 6 h. After filtration, the filter cake was added to 6897 g of deionized water and heated to 45 °C for 3 h with stirring. The temperature was then lowered to 0-5 °C, and the pH of the system was adjusted to 5-5.5 with a 15 wt% sodium hydroxide aqueous solution. At this point, a large amount of solid precipitated out. After standing for 30 min, the mixture was filtered. The filter cake was washed and dried to obtain modified DOPO. Step S05: Under nitrogen protection, 700g of polypropylene glycol (number average molecular weight 2000) and 200g of 4,4'-diphenylmethane diisocyanate were added to a reaction vessel. The mixture was heated to 80℃ with stirring and kept at this temperature for 3 hours. Samples were taken every 30 minutes during the reaction. The isocyanate group content in the system was determined using the di-n-butylamine method. When the isocyanate group content reached the theoretically calculated value, the temperature was lowered to 15-20℃. 200g of modified DOPO was dissolved in anhydrous ethyl acetate and added dropwise to the system over a period of 60 minutes. After the addition was complete, the mixture was brought back to room temperature and stirred for 1.5 hours. Anhydrous ethyl acetate was added to adjust the solid content of the system to 30-40%. Then, 10g of BYK-066N and 8g of BYK-410 were added. After stirring evenly, the mixture was degassed under vacuum to obtain the modified polyurethane adhesive.

[0045] Comparative Preparation Example 1: The difference between Comparative Preparation Example 1 and Preparation Example 2 is that steps S01-S04 are omitted, the modified DOPO in step S05 is replaced with DOPO-MA, and 56.21g of diethyltoluene diamine is added as a chain extender. The chemical structural formula of DOPO-MA is as follows: .

[0046] Comparative Preparation Example 2: The difference between Comparative Preparation Example 2 and Preparation Example 2 is that steps S01-S04 are omitted, and the modified DOPO in step S05 is replaced with 6-(3-(bis(2-aminoethylpropyl)dibenzo[c,e][1,2]oxophosphazenecyclohexane-6-oxide), the chemical structure of which is as follows: .

[0047] Comparative Preparation Example 3: The difference between Comparative Preparation Example 3 and Preparation Example 2 is that steps S01-S04 are omitted, the modified DOPO in step S05 is replaced with DOPO, and 56.21g of diethyltoluene diamine is added as a chain extender.

[0048] Comparative Preparation Example 4: The difference between Comparative Preparation Example 4 and Preparation Example 2 is that steps S01-S04 are omitted, and in step S05, modified DOPO is not added, but 56.21g of diethyltoluene diamine is added as a chain extender.

[0049] The alternative compounds in the comparative preparation examples can all be prepared using conventional synthetic methods, and their synthetic steps will not be described in detail here.

[0050] Example 1: A specific preparation method of an enhanced connection composite insulation board, comprising the following steps: S1. Cut the rock wool strips to a width of 600mm and a height of 2800mm, clean the surface of dust, loose fibers and debris, and ensure that the bonding surface is clean and dry to obtain the insulation layer; S2. Cut the fiber-reinforced calcium silicate boards used for the outer and inner crack-resistant layers to a width of 600mm and a height of 2800mm. Clean the dust, oil, and release agent residue from the surfaces of the boards to be bonded, ensuring that the boards are clean and dry. S3. A 1 mm thick layer of modified polyurethane adhesive prepared according to Preparation Example 1 is uniformly coated on the inner side surface of the outer fiber-reinforced calcium silicate board to form a first adhesive layer. The insulation layer is laid flat on the first adhesive layer and lightly pressed to ensure full adhesion. Then, a 1 mm thick layer of modified polyurethane adhesive is uniformly coated on the other side of the insulation layer to form a second adhesive layer. The inner fiber-reinforced calcium silicate board is laid flat on the second adhesive layer, and the four sides are aligned to obtain a laminated board. S4. The laminated boards are fed into a flatbed cold press and held at 0.3MPa for 20 minutes. After depressurization, the boards are sent into an oven and treated at 65℃ with forced ventilation (air velocity inside the oven is 0.6 m / s) for 40 minutes. They are then cured in an environment of 15-25℃ and relative humidity ≥50% for 7 days. After trimming, shaping, and tongue and groove jointing, the reinforced composite insulation board is obtained.

[0051] Example 2: A specific preparation method of an enhanced connection composite insulation board, comprising the following steps: S1. Cut the rock wool strips to a width of 600mm and a height of 2800mm, clean the surface of dust, loose fibers and debris, and ensure that the bonding surface is clean and dry to obtain the insulation layer; S2. Cut the fiber-reinforced calcium silicate boards used for the outer and inner crack-resistant layers to a width of 600mm and a height of 2800mm. Clean the dust, oil, and release agent residue from the surfaces of the boards to be bonded, ensuring that the board surfaces are clean and dry. S3. A 1 mm thick layer of modified polyurethane adhesive prepared according to Preparation Example 2 is uniformly coated on the inner side of the outer fiber-reinforced calcium silicate board to form a first adhesive layer. The insulation layer is laid flat on the first adhesive layer and lightly pressed to ensure full adhesion. Then, a 1 mm thick layer of modified polyurethane adhesive is uniformly coated on the other side of the insulation layer to form a second adhesive layer. The inner fiber-reinforced calcium silicate board is laid flat on the second adhesive layer, and the four sides are aligned to obtain a laminated board. S4. The laminated boards are fed into a flat cold press and held at 0.4MPa for 30 minutes. After depressurization, the boards are sent into an oven and treated at 70℃ with forced ventilation (air velocity inside the oven is 1.0 m / s) for 50 minutes. They are then cured in an environment of 15-25℃ and relative humidity ≥50% for 7 days. After trimming, shaping, and tongue and groove jointing, the reinforced composite insulation board is obtained.

[0052] Example 3: A specific preparation method of an enhanced connection composite insulation board, comprising the following steps: S1. Cut the rock wool strips to a width of 600mm and a height of 2800mm, clean the surface of dust, loose fibers and debris, and ensure that the bonding surface is clean and dry to obtain the insulation layer; S2. Cut the fiber-reinforced calcium silicate boards used for the outer and inner crack-resistant layers to a width of 600mm and a height of 2800mm. Clean the dust, oil, and release agent residue from the surfaces of the boards to be bonded, ensuring that the board surfaces are clean and dry. S3. A 1 mm thick layer of modified polyurethane adhesive prepared according to Preparation Example 3 is uniformly coated on the inner side surface of the outer fiber-reinforced calcium silicate board to form a first adhesive layer. The insulation layer is laid flat on the first adhesive layer and lightly pressed to ensure full adhesion. Then, a 1 mm thick layer of modified polyurethane adhesive is uniformly coated on the other side of the insulation layer to form a second adhesive layer. The inner fiber-reinforced calcium silicate board is laid flat on the second adhesive layer, and the four sides are aligned to obtain a laminated board. S4. The laminated boards are fed into a flatbed cold press and held at 0.5MPa for 40 minutes. After depressurization, the boards are sent into an oven and treated at 75℃ with forced ventilation (air velocity inside the oven is 1.2 m / s) for 60 minutes. They are then cured in an environment of 15-25℃ and relative humidity ≥50% for 7 days. After trimming, shaping, and tongue and groove jointing, the reinforced composite insulation board is obtained.

[0053] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that the modified polyurethane adhesive prepared according to Preparation Example 2 in S2 is replaced with the modified polyurethane adhesive prepared according to Comparative Preparation Example 1.

[0054] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that the modified polyurethane adhesive prepared according to Preparation Example 2 in S2 is replaced with the modified polyurethane adhesive prepared according to Comparative Preparation Example 2.

[0055] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the modified polyurethane adhesive prepared according to Preparation Example 2 in S2 is replaced with the modified polyurethane adhesive prepared according to Comparative Preparation Example 3.

[0056] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that the modified polyurethane adhesive prepared according to Preparation Example 2 in S2 is replaced with the modified polyurethane adhesive prepared according to Comparative Preparation Example 4.

[0057] Application example: Construction and application of external wall insulation systems with reinforced composite insulation boards. This application example uses the reinforced composite insulation board (specifications: width 600mm, height 2800mm) prepared in Example 2 to carry out the cast-in-place construction of the external wall insulation system. The specific steps are as follows: Pre-construction preparation: After completing the reinforcement binding of the shear walls and edge components of the standard floor of the residential project and passing the supervisor's acceptance, cement mortar protective layer limiting blocks are bound to the outside of the reinforcement. The strength of the blocks is consistent with the strength of the wall concrete, and the arrangement density is 4 blocks / m². 2 Based on the building's baseline axis, accurately project the wall edge lines, formwork control lines, and insulation board installation positioning lines, and verify that the elevations are correct; complete the detailed layout of the insulation boards and the technical and safety briefings for the construction team in advance; and ensure that the supporting system connectors, formwork system materials, and concrete have all been inspected and approved upon arrival on site. Insulation board installation: Install according to the prefabricated layout drawing, following the order of first installing the corner panels and then the main wall panels. Adjacent insulation boards are spliced ​​together by prefabricated tongue and groove joints on the sides. The tongue and groove joints are pre-filled with building sealant. After splicing, the joint width is controlled within 3mm. After each board is in place, use galvanized binding steel wire to tie and fix the insulation board to the wall's reinforcing steel bars. Check that the verticality deviation of the board surface is ≥3mm / m and that the flatness of the board surface meets the requirements. System connector installation: Drill holes in the insulation board using an impact drill according to the preset quincunx pattern, and hammer in the system connectors. Ensure that the effective length of the un-corrosion-protected section of the connector end is anchored into the cast-in-place concrete ≥ 100mm. The number of connectors installed on the board surface is 8 per m. 2 Two connectors are added on each side within a 200mm radius around the door and window openings. After installation, the inner end of the connector is firmly tied to the reinforcing steel bar of the wall. Installation of the inner formwork system: Install 15mm thick plywood formwork and matching steel pipe support brackets on the inner side of the wall. Drill holes at the corresponding positions and install through-wall tie bolts. Use permanent water-stop bolts with water-stop plates on the water-facing side of the outer wall. The bolt holes should avoid the joints of the insulation board and be ≥50mm away from the edge of the board joint. Install the vertical secondary ribs and horizontal main ribs of the formwork. Adjust and correct the verticality, flatness and wall design thickness of the board surface by using tie bolts. After acceptance, tighten and fix it. Apply sponge strips to the joints of the formwork to seal and prevent grout leakage. Concrete pouring and curing: Use commercial concrete with a design strength grade of C30, slump controlled at 160±20mm, maximum coarse aggregate size ≤20mm, pour the wall concrete in layers continuously, with each layer height ≤500mm, and use a φ30 immersion vibrator for compaction. During the compaction process, it is strictly forbidden for the vibrator to directly contact the composite insulation board, system connectors and formwork to avoid damage or displacement of the boards. After pouring, the top surface of the concrete should be finished according to the specifications, and a film covering and moisture retention curing should be carried out for a curing time of not less than 14 days. Formwork removal and joint treatment: After the concrete strength reaches the design requirement for formwork removal, remove the main and secondary ribs, inner formwork, and support system in sequence; fill and level the joints of the insulation boards with polymer crack-resistant mortar, and lay 300mm wide alkali-resistant fiberglass mesh at the joints for crack resistance reinforcement; lay reinforcing mesh at the inside and outside corners and the four corners of door and window openings, fill the tie bolt holes with polyurethane foam, and then seal and level them with waterproof mortar, and do a good job of waterproofing and crack resistance; Finishing layer construction: The surface of the fiber-reinforced calcium silicate board on the outside of the insulation board is flat and does not require overall plastering. Apply two coats of water-resistant putty directly, sand it smooth, and then apply the primer and exterior wall elastic topcoat according to the exterior facade design requirements to complete the construction of the entire exterior wall insulation system.

[0058] Performance testing: The performance tests used the reinforced composite insulation boards prepared in Examples 1-3 and Comparative Examples 1-3, along with the corresponding modified polyurethane adhesives, as the test objects. All samples were conditioned for 24 hours in a standard test environment (temperature 23±2℃, relative humidity 50±5%) before testing. The testing process strictly followed the current national and industry standards such as GB / T 20284-2006, GB / T 8624-2012, GB / T 2406.2-2009, GB / T 7124-2008, JG / T 536-2017, GB / T 5486-2008, and JGJ 144-2019. The experimental results are shown in Table 1.

[0059] Table 1 Performance Test Results

[0060] Data Analysis: As can be seen from the performance test data in Table 1, the composite insulation board prepared by the technical solution of the present invention in the embodiments shows significant comprehensive advantages in the core performance of building insulation composite boards, such as fire resistance, interface adhesion, and thermal insulation performance. In particular, Embodiment 2 achieves a balance of key performances, with the best comprehensive performance. All indicators are better than the industry standard limits and also better than the comparative sample.

[0061] The comprehensive advantages of this invention in terms of combustion-related fire-retardant performance stem from the intrinsic flame-retardant molecular design of the modified polyurethane adhesive. This invention synthesizes a functional monomer integrating DOPO phosphaphenanthrene flame-retardant groups, bis-primary amino chain-extending sites, and bis-carboxyl anchoring groups. This monomer, acting as a diamine chain extender, directly participates in the polyurethane polymerization reaction, allowing the phosphaphenanthrene flame-retardant groups to be permanently embedded in the polyurethane molecular backbone through stable covalent bonds. This is completely different from physical blending modification methods, fundamentally eliminating the migration and loss of flame retardants, and achieving a uniform and stable distribution of flame-retardant groups in the polyurethane system. The DOPO phosphaphenanthrene groups possess a dual-effect flame-retardant mechanism in both the gas and condensed phases. At high temperatures, they can decompose in the gas phase to generate phosphorus-oxygen free radicals, capturing active intermediates in the combustion chain reaction to interrupt the combustion process. Simultaneously, in the condensed phase, they promote the rapid formation of a dense and stable char layer in the polyurethane matrix, isolating heat and oxygen transfer, significantly improving the flame-retardant performance of the adhesive itself. This results in the adhesives in the embodiments having a high limiting oxygen index and achieving the highest V-0 vertical burning rating. Combined with the non-combustible properties of the rock wool core material, the composite insulation board in this embodiment consistently meets the Class A fire resistance standard. At the same time, key combustion indicators such as total calorific value, combustion growth rate index, and total heat release in the first 600 seconds are all at extremely low levels, fully meeting the stringent fire resistance requirements for building exterior wall insulation materials.

[0062] The significant advantages of this invention in terms of mechanical bonding performance stem from the modified DOPO's dicarboxyl interfacial anchoring structure design. In the adhesive's molecular structure, the strongly polar dicarboxyl groups do not participate in the polyurethane cross-linking and curing reaction, remaining intact in the cured adhesive layer. On one hand, this significantly reduces the surface tension of the adhesive system, improving wettability to the rough inorganic interfaces of porous rock wool fibers and calcium silicate boards, allowing the adhesive to fully penetrate the micropores of the substrate and form a strong mechanical anchoring structure after curing. On the other hand, the carboxyl groups can form strong hydrogen bonds and stable chelate chemical bonds with the silanol groups and hydrated calcium ions on the surface of the inorganic substrate, completely solving the problem of weak interfacial bonding of ordinary polyurethane adhesives to inorganic substrates. Simultaneously, the highly polar urea bonds generated by the reaction of the functional monomer's primary amino groups with isocyanates can form a strong intermolecular hydrogen bond network in the polyurethane system, significantly improving the adhesive's cohesive strength and thus significantly enhancing the mechanical properties of the adhesive layer itself. The synergistic effect of the two results in the composite insulation board of the embodiment having a much higher vertical tensile strength and minimum vertical bonding strength between layers than the comparative examples, achieving a high-strength bond between the rigid surface layer and the rock wool insulation layer, and ensuring the structural integrity of the composite board.

[0063] In terms of the two fundamental properties of density and thermal conductivity, there were no significant differences in the test data of the examples and comparative examples. The overall density of the composite insulation board is mainly determined by the rock wool core material and the fiber-reinforced calcium silicate board. The proportion of polyurethane adhesive in the composite board is low, so adjustments to different adhesive formulations will not have a significant impact on the overall density of the composite board, and the density values ​​of each group only show slight normal fluctuations. As for the thermal conductivity of the composite insulation board, it is mainly dominated by the inorganic fiber structure of the rock wool insulation layer. The adhesive modification scheme of this invention only optimizes the flame retardant and bonding performance of the bonding layer, without destroying the thermal insulation structure of the rock wool core material. Therefore, the thermal conductivity of all samples is at the same level. This invention significantly improves the fire resistance and bonding performance of the composite board while completely retaining the original low thermal conductivity advantage of the rock wool core material, ensuring the core thermal insulation function of the composite insulation board.

[0064] In comparison, Comparative Example 1 uses DOPO-MA monomers containing only flame-retardant groups and hydrophilic anchoring carboxyl groups, combined with a common diamine chain extender to prepare the adhesive, achieving only physical flame-retardant modification of polyurethane. Test data shows that the flame-retardant performance of the adhesive in Comparative Example 1 is acceptable, achieving a vertical burning rating of V-0. Combined with rock wool core material, it can also achieve a Class A fire resistance rating for the composite board. The combustion-related indicators are similar to those of the embodiment. However, its vertical tensile strength and interlayer vertical bond strength are far lower than those of the embodiment of this invention. The fundamental reason is that the flame-retardant components in its adhesive system, being physically blended, exhibit uneven phase distribution and are prone to precipitation. This prevents the formation of strong bonds with inorganic substrates such as rock wool and calcium silicate board, resulting in physical weaknesses and weakened interfacial adhesion.

[0065] Comparative Example 2 uses a DOPO-type flame-retardant chain extender containing diamino groups. Although this allows flame-retardant groups to be covalently attached to the polyurethane main chain, ensuring the basic flame-retardant properties of the adhesive and achieving a Class A fire rating for the composite board, its molecular structure lacks dicarboxyl interfacial anchoring groups, failing to address the interfacial compatibility issue between the polyurethane and the inorganic substrate. Therefore, while the bonding performance of Comparative Example 2 is slightly better than that of Comparative Example 1, it still falls short of the embodiments of this invention, failing to achieve high-strength bonding between the rigid surface layer and the rock wool core material, and thus is ill-suited to the engineering application requirements of composite insulation boards.

[0066] Comparative Example 3 uses a conventional physical blending method to add DOPO flame retardant, failing to achieve molecular-level copolymerization modification, which is also the most significantly flawed approach in existing technologies. Regarding flame retardant performance, the DOPO flame retardant exists only in a physically dispersed form within the polyurethane system, without chemical bonding to the matrix. Its flame retardant efficiency is far lower than the covalent bonding approach of this invention. Consequently, the limiting oxygen index of the adhesive is significantly lower, and the vertical burning rating only reaches V-1. The overall fire resistance rating of the composite insulation board also drops to B1. Combustion indicators such as total calorific value, combustion growth rate, and total heat release all show significant deterioration, failing to meet high-level fire resistance requirements. Furthermore, this system lacks any interfacial bonding reinforcement design. Ordinary polyurethane adhesives have poor adhesion to inorganic substrates, resulting in extremely low vertical tensile strength and interlayer bond strength, completely failing to meet the requirements for composite insulation board use.

[0067] Comparative Example 4 is a conventional polyurethane adhesive without any flame-retardant modification, prepared using only a standard diamine chain extender. It lacks both the DOPO flame-retardant groups of this invention and the interfacially reinforced carboxyl anchoring groups. Test data shows that this polyurethane adhesive completely fails to meet fire resistance standards. The adhesive has no vertical burning rating, and the composite insulation board has a fire rating of only B2. Its total calorific value, combustion growth rate, and total heat release far exceed the standard limits, posing a significant fire safety hazard. Furthermore, the conventional polyurethane adhesive exhibits weak interfacial bonding to inorganic substrates; its vertical tensile strength and interlayer bond strength are the lowest among all samples, making it unable to achieve stable bonding between structural layers and completely unsuitable for building exterior wall insulation applications.

[0068] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A reinforced composite insulation board, characterized in that, From the outside to the inside, it includes an outer crack-resistant layer, a first adhesive layer, a thermal insulation layer, a second adhesive layer, and an inner crack-resistant layer. The outer crack-resistant layer and the inner crack-resistant layer are made of rigid board material; the rigid board material includes fiber-reinforced calcium silicate board or cement board. The first adhesive layer and the second adhesive layer are made of modified polyurethane adhesive; The insulation layer is made of rock wool strips; The preparation method of the modified polyurethane adhesive includes the following steps: Step S01: Under nitrogen protection, DOPO and triphenylphosphine are added to a toluene / tetrahydrofuran mixed solvent, heated to 60-70℃ and stirred until dissolved. Then, 3-hydroxy-2,5-furandione is added in batches over 1 hour. After the addition is complete, the temperature is raised to 90-100℃ and the reaction is maintained for 8-12 hours. After cooling to room temperature, the mixture is filtered. The filter cake is washed three times with a tetrahydrofuran / ethanol mixed solvent and then dried to obtain intermediate A. Step S02: Under nitrogen protection, intermediate A and epichlorohydrin are added to anhydrous acetonitrile and stirred until completely dissolved. Anhydrous potassium carbonate is added, and the temperature is raised to 65-75℃. The reaction is carried out in the dark for 10-12 hours. After the reaction is completed, the mixture is cooled to room temperature and filtered. The filtrate is then distilled under reduced pressure to remove epichlorohydrin and solvent, yielding intermediate B. Step S03: Under nitrogen protection, intermediate B is added to anhydrous dichloromethane and stirred until dissolved. Then, 1,7-bis-BOC-1,4,7-triazaheptane is added, the temperature is raised to 30-40℃, and the reaction is stirred for 3-6 hours. After cooling to room temperature, the solvent is removed by vacuum distillation to obtain intermediate C. Step S04: Under nitrogen protection, intermediate C is added to anhydrous dichloromethane and stirred until homogeneous. Trifluoroacetic acid is added dropwise at room temperature over 30-60 minutes. After the addition is complete, the mixture is stirred at room temperature for 4-6 hours. After filtration, the filter cake is added to deionized water and heated to 40-45°C with stirring for 2-3 hours. The temperature is then lowered to 0-5°C, and the pH of the system is adjusted to 5-5.5 with sodium hydroxide aqueous solution. At this point, a large amount of solid precipitates out. After standing for 30 minutes, the mixture is filtered. The filter cake is washed and dried to obtain modified DOPO. Step S05: Under nitrogen protection, polypropylene glycol and 4,4'-diphenylmethane diisocyanate are added to a reaction vessel and heated to 70-80℃ with stirring. The reaction is maintained at this temperature for 2-3 hours, with periodic sampling during the process. The isocyanate group content in the system is determined using the di-n-butylamine method. When the isocyanate group content reaches the theoretically calculated value, the temperature is lowered to 15-20℃. Modified DOPO is dissolved in anhydrous ethyl acetate and added dropwise to the system over a period of 30-60 minutes. After the addition is complete, the system is brought back to room temperature and stirred for 0.5-1.5 hours. Anhydrous ethyl acetate is added to adjust the solid content of the system to 30-40%. Then, defoamer and rheology modifier are added, and the mixture is stirred evenly. The mixture is then degassed under vacuum to obtain the modified polyurethane adhesive.

2. The reinforced composite insulation board according to claim 1, characterized in that, In step S01, the molar ratio of DOPO, triphenylphosphine, and 3-hydroxy-2,5-furandione is 1:0.01-0.015:1-1.1; the weight ratio of DOPO and toluene / tetrahydrofuran mixed solvent is 1:5-10; the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran mixed solvent is 1:1; and the volume ratio of tetrahydrofuran to ethanol in the tetrahydrofuran / ethanol mixed solvent is 1:

1.

3. The reinforced composite insulation board according to claim 1, characterized in that, In step S02, the molar ratio of intermediate A, epichlorohydrin, and anhydrous potassium carbonate is 1:1.5-2.5:2-3; the weight ratio of intermediate A and anhydrous acetonitrile is 1:4-10.

4. The reinforced composite insulation board according to claim 1, characterized in that, In step S03, intermediate B and 1,7-bis-BOC-1,4,7-triazaheptane are in a molar ratio of 1:1.1-1.2; intermediate B and anhydrous dichloromethane are in a weight ratio of 1:8-12.

5. The reinforced composite insulation board according to claim 1, characterized in that, In step S04, the molar ratio of intermediate C to trifluoroacetic acid is 1:3-5; the weight ratio of intermediate C, anhydrous dichloromethane, and deionized water is 1:10-15:5-10; and the concentration of the sodium hydroxide aqueous solution is 5-15 wt%.

6. The reinforced composite insulation board according to claim 1, characterized in that, In step S05, the weight ratio of polypropylene glycol, 4,4'-diphenylmethane diisocyanate, modified DOPO, defoamer, and rheology modifier is 60-70:15-20:12-20:0.5-1:0.3-0.8; the number average molecular weight of polypropylene glycol is 2000; the defoamer is BYK-066N; and the rheology modifier is BYK-410.

7. A method for preparing a reinforced composite insulation board as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Cut the rock wool strips to the design size, clean the surface of dust, loose fibers and debris, and ensure that the bonding surface is clean and dry to obtain the insulation layer; S2. Cut the rigid boards used for the outer crack-resistant layer and the inner crack-resistant layer to the design size, clean the dust, oil stains and release agent residue on the surfaces of the boards to be bonded, and ensure that the board surfaces are clean and dry; S3. Apply a 1mm thick modified polyurethane adhesive evenly to the inner side of the outer crack-resistant layer to form the first adhesive layer. Lay the insulation layer flat on the first adhesive layer and press lightly to ensure full adhesion. Then apply a 1mm thick modified polyurethane adhesive evenly to the other side of the insulation layer to form the second adhesive layer. Lay the inner crack-resistant layer flat on the second adhesive layer and align the four sides to obtain the laminated board. S4. After letting the laminated boards stand at room temperature for 20-40 minutes, they are sent to a flatbed cold press and pressed at 0.3-0.5MPa for 15-25 minutes. After depressurization, the boards are sent to an oven and treated at 65-75℃ in a forced ventilation environment for 40-60 minutes. Then, they are cured in an environment of 15-25℃ and relative humidity ≥50% for 7 days. After trimming, shaping, and tongue and groove jointing, the reinforced composite insulation board is obtained.

8. The method for preparing the reinforced composite insulation board according to claim 7, characterized in that, The design dimensions are any one of the following: width 300mm, 400mm, 600mm, 800mm, 900mm or 1200mm, and height 2800mm-3000mm.

9. The method for preparing the reinforced composite insulation board according to claim 7, characterized in that, In S4, forced ventilation refers to an air velocity of 0.6-1.2 m / s inside the oven.

10. A construction method for an external wall insulation system with reinforced composite insulation board as described in claims 1-6, characterized in that, Includes the following steps: a. Pre-construction preparation: Complete the reinforcement binding of the external shear walls, beams and columns. After acceptance, bind cement mortar protective layer limiting blocks on the outside of the reinforcement, with a block density of no less than 4 blocks / m². 2 Based on the building axis, mark the wall edge lines, formwork control lines, and insulation board installation positioning lines; b. Insulation board installation: According to the prefabricated layout drawing, install the reinforced composite insulation boards in the order of first the corner panels and then the main wall panels. Adjacent insulation boards are spliced ​​by interlocking tongue and groove joints, with sealant pre-filled inside the tongue and groove joints. The joint width after splicing is ≤3mm. After positioning, use binding steel wire to fix the insulation board to the wall reinforcement, ensuring that the verticality deviation of the board surface is ≤3mm / m. c. System connector installation: Drill holes in the insulation board at the preset points, hammer in the system connectors, and ensure that the effective length of the end of the system connector anchored into the cast-in-place concrete is ≥100mm. The number of system connectors installed per square meter shall not be less than 8, and they shall be evenly arranged in a quincunx pattern. The spacing between adjacent connectors shall be ≤400mm. Additional system connectors shall be installed within 200mm around the door and window openings. After installation, the inner end of the system connector shall be firmly tied to the wall reinforcement. d. Template system installation: Install the inner wall template and matching support brackets, and install through-wall tie bolts at the corresponding positions. Use water-stop bolts with water-stop plates for the waterproof parts of the outer wall. The bolt holes should avoid the joints of the insulation board and be ≥50mm away from the edge of the board joint. Install the main and secondary ribs of the template, and tighten them after correcting the verticality and flatness of the board surface and the design thickness of the wall. e. Concrete pouring and curing: Concrete with a slump of 160±20mm shall be poured in layers continuously, with each layer height ≤500mm. An immersion vibrator shall be used for compaction. During the compaction process, the vibrator shall not be allowed to directly contact the reinforced composite insulation board, system connectors and formwork. After pouring, the concrete shall be kept moist and cured in accordance with the specifications. f. Formwork Removal and Joint Treatment: After the concrete reaches the design demolding strength, remove the inner formwork, main and secondary ribs, and support system; fill and level the joints of the insulation boards with polymer crack-resistant mortar, and lay alkali-resistant fiberglass mesh with a width of ≥300mm at the joints for crack resistance reinforcement; waterproof and seal the corners, door and window openings, tie bolt holes, and reserved holes for crack resistance reinforcement. g. Finishing layer construction: According to the exterior facade design requirements, complete the construction of the leveling layer, crack-resistant layer and finishing layer, and complete the construction of the external wall insulation system with reinforced composite insulation board; The main rod of the system connector is an HRB400 grade 8mm diameter threaded steel bar, with an anti-corrosion anchor plate of ≥60mm diameter at the outer end. The rod body passing through the insulation board and the outer side of the anchor plate are wrapped with engineering plastic hot melt anti-corrosion coating. The tensile bearing capacity and pull-out force of a single connector are both ≥0.60kN.

Images