A heat-reflecting aerogel PET composite insulation board and a preparation method thereof

Abstract

The present application relates to the technical field of covering or lining made of organic plastic with or without reinforcement or filling material, discloses a heat-reflecting aerogel PET composite thermal insulation board and a preparation method thereof, in the present application, the inventor finds that, since the ductility of inorganic adhesive is very poor after curing, and the stiffness of foamed PET substrate cannot effectively resist deformation, the adhesive film of inorganic adhesive is broken by shear force when being pulled. At the same time, the inorganic adhesive and the foamed PET substrate have large difference in thermal deformation, and the adhesive film is broken and falls off due to temperature stress. Based on this finding, the inventor improves the ductility of the adhesive film by adding aerogel powder, so that the adhesive film is not easy to break when bearing shear force, and the thermal deformation is consistent with that of the foamed PET substrate, so that subsequent building construction can be carried out on the aerogel modified layer without difficulty. At the same time, the aerogel modified layer is fireproof, waterproof, mildewproof, and the infrared reflectivity is above 0.85, so that the fireproof and thermal insulation performance of the composite thermal insulation board is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of covering or lining technology using organic plastics with or without reinforcements or fillers, and in particular to a heat-reflective aerogel PET composite insulation board and its preparation method. Background Technology

[0002] Aerogel is a novel type of thermal insulation material with significantly better insulation performance than other types of insulation materials. Aerogel has open pores with a pore size of 20-50 nanometers. Commercially available aerogel products mainly exist in the form of aerogel powder and aerogel felt.

[0003] Foamed PET boards are building panels made of foamed polyester plastic. Their raw materials are widely available, including discarded mineral water bottles, thus achieving waste utilization. Unlike other building insulation materials, foamed PET boards possess good mechanical strength and can be used as load-bearing components.

[0004] However, foamed PET boards have a major drawback that is very difficult to overcome: they are difficult to bond with other building materials.

[0005] Organic adhesive bonding: Due to the chemical properties of the foamed PET board itself, the adhesive film formed by water-based organic adhesives cannot effectively bond with the foamed PET board and will separate from each other shortly after curing; while oil-based organic adhesives will corrode the foamed PET board.

[0006] Cement mortar bonding: The bond between the foamed PET board and the cement mortar is very weak, with an adhesion of less than 0.1 MPa.

[0007] Inorganic adhesive bonding: Inorganic adhesives have better adhesion than cement mortar, but the bonding is very easy to fail. After other building components are bonded to foamed PET boards with inorganic adhesives, they will fall off due to thermal expansion and contraction or repeated pulling.

[0008] Mechanical connections: It is difficult to seal the holes (with gaps around the holes) that penetrate the foamed PET board using mechanical connectors such as bolts, because the materials used to seal holes in conventional building materials are essentially adhesives or cement mortar. If foamed PET boards are used on building exterior walls, mechanical connections can lead to building leaks.

[0009] For the reasons mentioned above, the application of existing foamed PET boards is quite limited. Foamed PET boards are not suitable for use in scenarios where subsequent decoration or electromechanical construction is required on the boards, such as building wall panels. Summary of the Invention

[0010] This invention provides a heat-reflective aerogel PET composite insulation board and its preparation method.

[0011] The technical problem to be solved is that foamed PET boards are difficult to connect with other building materials and are not suitable for use in scenarios where subsequent decoration or electromechanical construction needs to be carried out on the boards.

[0012] To solve the above technical problems, the present invention adopts the following technical solution: a heat-reflective aerogel PET composite insulation board, comprising a foamed PET substrate and an aerogel modified layer coated on both sides of the foamed PET substrate, wherein an anti-crack mesh is embedded in the aerogel modified layer to prevent the extension of cracks in the aerogel modified layer.

[0013] The aerogel modified layer is an inorganic adhesive doped with aerogel powder and is in the form of a bendable foamed material.

[0014] Furthermore, the infrared reflectance of the aerogel modified layer is not less than 0.85.

[0015] Furthermore, the inorganic adhesive is a silicate adhesive.

[0016] Furthermore, the aerogel powder is silica aerogel powder.

[0017] Furthermore, the closed-cell rate of the foamed PET substrate is not less than 85%.

[0018] Furthermore, the crack-resistant mesh is a basalt mesh or a carbon fiber mesh.

[0019] A method for preparing a heat-reflective aerogel-PET composite insulation board, characterized by the following steps: The method comprises preparing the aforementioned aerogel-PET composite insulation board, which facilitates subsequent construction.

[0020] Step 1: Stir and mix the aerogel powder and inorganic adhesive thoroughly;

[0021] Step 2: Apply the inorganic adhesive containing aerogel powder to the surface of the flat foamed PET substrate to form an aerogel modified layer. Then, spread the anti-crack mesh on the aerogel modified layer and smooth it out so that the anti-crack mesh is embedded in the aerogel modified layer.

[0022] Step 3: After the aerogel modified layer solidifies, flip the foamed PET substrate and repeat step 2 to ensure that both sides of the foamed PET substrate are coated.

[0023] Furthermore, in step one, the aerogel powder and the inorganic adhesive are mixed under constant temperature or cooling conditions, and ultrasonic treatment is not allowed during the mixing process to ensure that the air in the aerogel powder is not replaced by the inorganic adhesive.

[0024] Compared with existing technologies, the present invention provides a heat-reflective aerogel PET composite insulation board and its preparation method, which have the following advantages:

[0025] In this invention, the inventors discovered that the reason why the connection of other building components to a foamed PET substrate using inorganic adhesives is prone to failure is that inorganic adhesives (whether silicate or phosphate adhesives) have poor ductility after curing. They are easily broken under shear forces perpendicular to the adhesive film direction. Furthermore, the foamed PET substrate is less rigid than steel or concrete, and cannot effectively resist deformation when the building components bonded to it by the inorganic adhesive are pulled, leading to the breakage of the inorganic adhesive film under shear forces. Simultaneously, the difference in thermal deformation between the inorganic adhesive and the foamed PET substrate (which serves as the foaming material) is significant. During thermal expansion and contraction, the inorganic adhesive film is subjected to enormous temperature stress, causing it to crack and detach.

[0026] Based on this discovery, the inventors significantly improved the ductility of the adhesive film by adding aerogel powder to the inorganic adhesive, transforming it into a foaming material. This made the film less prone to breakage under shear force, and its thermal deformation was consistent with that of the foamed PET substrate, preventing cracking and detachment due to large differences in thermal deformation. Furthermore, the addition of an anti-crack mesh prevented further cracking even if the film did crack. Both the aerogel and the foamed PET substrate effectively bonded together, encapsulating the substrate. Subsequent construction work could then be carried out on the aerogel-modified layer, eliminating problems caused by difficult bonding or corrosion of the foamed PET substrate. Simultaneously, the aerogel also improved the thermal insulation performance of the foamed PET substrate.

[0027] The composite insulation board of this invention utilizes the combined action of adhesives and fiber mesh to enhance the board's rigidity, enabling it to bear structural loads. Simultaneously, the aerogel-modified layer exhibits fire resistance, water resistance, mildew resistance, and an infrared reflectivity exceeding 0.85 (the inventors discovered that the mixture of inorganic adhesives and aerogel powder possesses infrared reflective properties), and also reinforces the foamed PET substrate. This enhances the fire resistance and strength of the composite insulation board, providing both thermal insulation and heat reflection capabilities. The composite board's thermal resistance R-value is superior to that of the foamed PET substrate itself. The combination of these factors allows the composite insulation board of this invention to meet various requirements for structural strength, thermal insulation, and sound insulation in building walls / floors with extremely light weight and thin thickness. Its application in construction can achieve unprecedented new effects, such as building walls entirely fixed to light steel keels with adhesive, and ultra-thin, ultra-light underfloor heating systems. Attached Figure Description

[0028] Figure 1 This is a perspective view of a heat-reflective aerogel PET composite insulation board according to the present invention.

[0029] Figure 2 This is a cross-sectional view of a heat-reflective aerogel PET composite insulation board according to the present invention.

[0030] In the figure, 1-foamed PET substrate, 2-aerogel modified layer, 3-crack-resistant mesh. Detailed Implementation

[0031] like Figure 1-2 As shown, a heat-reflective aerogel PET composite insulation board includes a foamed PET substrate 1 and an aerogel modified layer 2 coated on both sides of the foamed PET substrate 1. An anti-crack mesh 3 is embedded in the aerogel modified layer 2 to prevent the extension of cracks in the aerogel modified layer 2.

[0032] The aerogel modified layer 2 is an inorganic adhesive doped with aerogel powder and is in the form of a bendable foamed material.

[0033] If the aerogel-modified layer 2 is a foamed material, its thermal deformation is consistent with that of the foamed PET substrate 1, while its ductility is significantly improved. In practical applications, the composite insulation board of this invention will not have the aerogel-modified layer 2 fall off even after repeated trampling by construction workers, and it can be firmly attached to tiles, junction boxes, cement mortar, various paints, wallpaper, and decorative panels. The surface texture of the aerogel-modified layer 2 is similar to frosted glass, a flat yet quite rough surface that can bond firmly to cement mortar without the need for roughening or scraping.

[0034] It is very difficult to make inorganic adhesives into foam materials that can be directly bonded to the foamed PET substrate 1. Existing inorganic adhesives, whether silicate-based or phosphate-based, cannot maintain stable air bubbles after being spread into a thin layer, and they will escape before curing.

[0035] However, if, as in this invention, powder containing air bubbles is incorporated into an inorganic adhesive to form a foamed material (because the adhesive film can only hold powder), it also presents numerous difficulties. In practice, it was found that closed-cell powder incorporated into an inorganic adhesive floats to the surface. While the floating phenomenon is improved with open-cell powder, the internal air bubbles are displaced by the inorganic adhesive during mixing, resulting in poor performance. After numerous attempts, the inventors discovered that because the pores in the aerogel powder are extremely small, by carefully controlling the stirring conditions, it is possible to ensure that the internal air bubbles are not displaced by the inorganic adhesive during mixing.

[0036] The infrared reflectance of the aerogel-modified layer 2 is not less than 0.85. Different inorganic adhesives exhibit different changes in infrared reflectance after the addition of aerogel powder; therefore, the amount of aerogel powder added needs to be adjusted according to the actual situation to change the infrared reflectance. Generally, the more aerogel powder added, the higher the infrared reflectance.

[0037] In this embodiment, the inorganic adhesive is a silicate adhesive, and the aerogel powder is silica aerogel powder. The interaction between the two in this combination is significant, effectively resisting buoyancy during mixing. Simultaneously, this combination bonds firmly to cement mortar (it can also bond reliably to other adhesives, but cement mortar is the most commonly used in construction).

[0038] In this embodiment, the closed-cell ratio of the foamed PET substrate 1 is not less than 85%. If the foamed PET substrate 1 is to be used as a building exterior wall panel, it needs to have sufficient waterproof effect. Therefore, there is a requirement for the closed-cell ratio to ensure that the waterproof effect is sufficient.

[0039] The crack-resistant mesh 3 is made of basalt mesh or carbon fiber mesh, which can be firmly bonded to the inorganic adhesive used here.

[0040] A method for preparing a heat-reflective aerogel PET composite insulation board, comprising the following steps:

[0041] Step 1: Stir and mix the aerogel powder and inorganic adhesive thoroughly;

[0042] Step 2: Apply the inorganic adhesive containing aerogel powder to the surface of the flat foamed PET substrate 1 to form the aerogel modified layer 2. Here, a toothed scraper can be used to control the thickness of the aerogel modified layer 2.

[0043] Then, the crack-resistant mesh 3 is spread on the aerogel modified layer 2 and smoothed, so that the crack-resistant mesh 3 is embedded in the aerogel modified layer 2;

[0044] Step 3: After the aerogel modified layer 2 solidifies, flip the foamed PET substrate 1 and repeat step 2 to complete the coating on both sides of the foamed PET substrate 1.

[0045] In step one, the aerogel powder and inorganic adhesive are mixed under constant temperature or cooling conditions, and ultrasonic treatment is prohibited during the mixing process to ensure that the air inside the aerogel powder is not displaced by the inorganic adhesive. The formulation of the inorganic adhesive and aerogel powder mentioned above ensures that the aerogel powder will not float. Here, the conditions during the stirring process are controlled to prevent the air bubbles in the aerogel powder from being displaced. Unlike the pores in catalyst particles, the pores in the aerogel powder contain air, which is immiscible with the inorganic adhesive. Furthermore, because the pores are small enough, as long as the air inside doesn't escape, it can prevent the inorganic adhesive from entering. Therefore, the temperature during the stirring process is controlled to prevent the air from expanding and escaping from the aerogel powder due to increased temperature. Ultrasonic vibration must also be avoided. While ultrasonic stirring is an efficient stirring method, its application here would expel the air from the aerogel powder.

[0046] In this embodiment, the composite insulation board has been sampled and sent for testing. The testing units are: Beijing CITIC Testing Holding Group Co., Ltd. and the National Building Materials Industry Building Materials and Structure Safety Quality Supervision and Inspection Center.

[0047] Test results show that the adhesion between the foamed PET substrate 1 and the aerogel modified layer 2 exceeds 0.6 MPa, while 0.35 MPa is sufficient to meet the requirements for tiling.

[0048] Meanwhile, the composite insulation board (12mm thick) in this embodiment has a surface density of 2.5 kg / m², while the surface density of paper-faced gypsum board of the same thickness is 8.7 kg / m², and the surface density of fiberglass high-strength gypsum board of the same thickness is 10 kg / m². The surface density of PET composite board is 1 / 3 to 1 / 4 of the above two types of gypsum board, but it has higher structural strength, insulation effect and other performance.

[0049] In addition, the thermal conductivity of the aerogel heat-reflective PET composite board is lower than that of the foamed PET substrate 1 of the same thickness, resulting in better heat preservation.

[0050] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A heat-reflective aerogel PET composite insulation board, characterized in that: It includes a foamed PET substrate (1) and an aerogel modified layer (2) coated on both sides of the foamed PET substrate (1). An anti-crack mesh (3) is embedded in the aerogel modified layer (2) to prevent the aerogel modified layer (2) from cracking. The aerogel modified layer (2) is an inorganic adhesive doped with aerogel powder and is in the form of a bendable foamed material; the thermal deformation of the aerogel modified layer (2) is consistent with that of the foamed PET substrate. Aerogel powder and inorganic adhesive are mixed under constant temperature or cooling conditions, and ultrasonic treatment is not allowed during the mixing process to ensure that the air in the aerogel powder is not replaced by the inorganic adhesive.

2. The heat-reflective aerogel PET composite insulation board according to claim 1, characterized in that: The infrared reflectance of the aerogel modified layer (2) is not less than 0.

85.

3. The heat-reflective aerogel PET composite insulation board according to claim 1, characterized in that: The inorganic adhesive is a silicate adhesive.

4. The heat-reflective aerogel PET composite insulation board according to claim 3, characterized in that: The aerogel powder is silica aerogel powder.

5. The heat-reflective aerogel PET composite insulation board according to claim 1, characterized in that: The closed-cell rate of the foamed PET substrate (1) is not less than 85%.

6. The heat-reflective aerogel PET composite insulation board according to claim 1, characterized in that: The crack-resistant mesh (3) is a basalt mesh or a carbon fiber mesh.

7. A method for preparing a heat-reflective aerogel PET composite insulation board, characterized in that: The method for preparing a heat-reflective aerogel PET composite insulation board as described in claim 4 includes the following steps: Step 1: Stir and mix the aerogel powder and inorganic adhesive thoroughly; Step 2: Apply the inorganic adhesive containing aerogel powder to the surface of the flat foamed PET substrate (1) to form an aerogel modified layer (2). Then spread the anti-crack mesh (3) on the aerogel modified layer (2) and smooth it out so that the anti-crack mesh (3) is embedded in the aerogel modified layer (2). Step 3: After the aerogel modified layer (2) solidifies, flip the foamed PET substrate (1) and repeat step 2 to complete the coating on both sides of the foamed PET substrate (1).

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