A kind of polyimide light fireproof composite board and preparation method thereof

Abstract

The present application provides a polyimide lightweight fireproof composite board and a preparation method thereof, the composite board comprises a heat insulation layer, a first anti-cracking layer and a first exterior layer stacked in sequence, and the adjacent layers are bonded by an adhesive layer; the heat insulation layer is composed of polyimide foam; the first anti-cracking layer is composited by silicone resin and polyimide filament woven mesh layer; the first exterior layer is composited by multiple layers of carbon fiber prepreg with a ceramic matrix; the adhesive layer is a polyimide resin layer. The composite board of the present application is made lighter by providing an exterior layer composed of carbon fiber prepreg with a ceramic matrix and a polyimide foam heat insulation layer, and the heat resistance and fire resistance of the composite board are increased; by using a polyimide filament woven mesh layer as the anti-cracking layer material, the overall structural strength and fire resistance and heat insulation of the composite board are improved; and the use of polyimide resin as an adhesive layer can effectively improve the toughening strength and temperature stability of the composite board.

Description

Technical Field

[0001] The present application belongs to the technical field of composite panels, and more specifically, relates to a polyimide lightweight fireproof composite panel and a preparation method thereof. Background Art

[0002] With the improvement of living standards, the requirements for building and home decoration materials are also constantly increasing. Sandwich panels are not only for decorative effects. Composite panels are made of polyimide and resin as the main raw materials and processed at high temperatures. Existing sandwich panels are monotonous in color, rough in surface, low in foundation strength, heavy in weight, and poor in sound absorption and noise reduction. If the preparation process is not handled properly, it is easy to cause corrosion and rust on the sandwich panels, which cannot meet people's demand for sandwich panels. At the same time, when multiple sandwich panels are spliced, they are usually glued together, with poor connection firmness and low overall strength.

[0003] At present, most of the sandwich panels on the market have flammable items in the middle of the interlayer fillers, and their own protection ability is low and the impact resistance is weak. However, when used in the fireproof sealing of the building interlayer structure, the sandwich panels are required to have higher fire resistance requirements. Ordinary sandwich panels cannot meet this requirement. At the same time, when one of the sandwich panels is damaged, it is easy to fail to play a fireproof role in the event of a fire. Moreover, it is heavy in weight and difficult to move in the event of collapse. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a polyimide lightweight fireproof composite board and a preparation method thereof, so as to solve the technical problems of low strength, poor fireproof performance and heavy material quality of sandwich panels in the prior art.

[0005] To achieve the above-mentioned object, in a first aspect of the present application, a polyimide lightweight fireproof composite panel is provided, wherein the composite panel comprises a heat insulation layer, a first anti-cracking layer and a first exterior layer stacked in sequence, and adjacent layers are bonded by an adhesive layer;

[0006] The heat insulation layer is composed of polyimide foam;

[0007] The first anti-cracking layer is composited by a silicone resin and a polyimide filament woven mesh layer;

[0008] The first exterior layer is composited with a multi-layer ceramic matrix carbon fiber prepreg;

[0009] The adhesive layer is a polyimide resin layer.

[0010] Furthermore, the composite plate is provided with countersunk holes, and the countersunk holes are used to drive countersunk nails.

[0011] Furthermore, a refuge chamber is provided in the heat insulation layer, and the refuge chamber is filled with polyimide resin.

[0012] Furthermore, it also includes a second anti-crack layer and a second exterior layer, wherein the second anti-crack layer and the first anti-crack layer are arranged in a mirror-symmetrical manner with respect to the heat insulation layer;

[0013] The second exterior decoration layer and the first exterior decoration layer are arranged in mirror symmetry with respect to the heat insulation layer.

[0014] Furthermore, the viscosity of the silicone resin is 5-8 Pa.s, and the shear strength is ≥15 kgf / cm 2 .

[0015] Furthermore, the breaking strength of the polyimide filament woven mesh layer is 3.9-4.4 GPa.

[0016] In a second aspect of the present application, a method for preparing a polyimide lightweight fireproof composite board is also provided, comprising the following steps:

[0017] Vacuum molding a multi-layer ceramic matrix of carbon fiber prepreg to obtain a first exterior layer;

[0018] Coating the organic silicone resin on the front and back sides of the high-strength and high-modulus mesh layer, and allowing the organic silicone resin to penetrate into the gaps of the high-strength and high-modulus mesh layer by extrusion to obtain a first anti-cracking layer;

[0019] Use polyimide foam as thermal insulation;

[0020] The first exterior layer, the first anti-cracking layer and the heat insulation layer are stacked in sequence, and a polyimide resin adhesive layer is applied between adjacent layers for bonding to obtain a composite board precursor;

[0021] Pre-curing the composite panel precursor at 120-130° C.;

[0022] The pre-cured board is vacuum cured at 300-320° C. to obtain a composite board.

[0023] Furthermore, the preparation process of the first anti-cracking layer also includes the step of coating a mixture of toluene and alkoxysilane on both sides of the high-strength and high-modulus mesh layer.

[0024] Furthermore, the mixture contains the following components in percentage by mass: 65-75% toluene, 5-10% alkoxysilane, 15-25% 2-propanol, and ≤5% tin fatty acid salt.

[0025] Furthermore, the pre-curing time is 0.1-1h; and / or the vacuum curing time is 0.1-1h.

[0026] Compared with the prior art, this application has the following technical effects:

[0027] A polyimide lightweight fireproof composite board of the present application is made lighter and has increased heat resistance and fire resistance of the composite board by setting an outer decorative layer composed of carbon fiber prepreg with a ceramic matrix and a polyimide foam insulation layer; the present application uses a high-strength and high-modulus mesh layer as the anti-cracking layer material, so that the silicone resin of the anti-cracking layer is distributed more evenly in the high-strength and high-modulus mesh layer, the compressive resistance is greatly improved, and the continuous use temperature is relatively increased. In terms of thermal insulation performance, the thermal conductivity coefficient is lower, the conduction distribution is more uniform, and the thermal conduction speed is slower, thereby improving the overall structural strength and fire resistance and heat insulation of the composite board; the present application uses a polyimide resin as an adhesive layer, and the polyimide resin has self-extinguishing properties when away from fire and has no droplets. The outer decorative layer composed of the carbon fiber prepreg is combined with the anti-cracking layer, which can maintain sufficient strength and modulus at high temperatures while reducing the heat conduction speed, thereby improving the buffering performance of the board, and improving the overall heat resistance and wear resistance of the board.

[0028] Existing polyimide foam insulation materials will generate dust during the installation and use process, are easy to break during the cutting and forming process, and the cut shape must completely conform to the surface to be bonded, otherwise it will not stick firmly and is not resistant to impact and vibration. The present application adopts a combination of an anti-cracking layer and polyimide foam to greatly reduce the overall thermal expansion coefficient of the board, while improving the sound insulation, vibration isolation and other functions of the board. Even in extremely cold and hot environments, its performance can be maintained unchanged, and it has extremely strong resistance to chemical agents. The composite board of the present application is anisotropic, and the arrangement of the anti-cracking layer can be designed according to different manufacturing conditions.

[0029] The present application uses polyimide resin as the bonding reinforcement material between the layers, which can effectively improve the toughening strength and temperature stability of the composite board, effectively improve the bonding strength and tensile strength between the board layers, make the composite board have a higher thermal decomposition temperature, and further improve the flame retardant effect of the composite board.

[0030] The preparation method of the polyimide lightweight fireproof composite board of the present application is simple, and each process condition of the preparation process is stable and controllable, and large-scale preparation can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A schematic structural diagram of a polyimide lightweight fireproof composite board provided in an embodiment of the present application.

[0033] In the figure, each reference numeral is:

[0034] 1. thermal insulation layer, 201. first anti-cracking layer, 202. second anti-cracking layer, 301. first exterior decoration layer, 302. second exterior decoration layer, 4. adhesive layer, 5. countersunk nails. DETAILED DESCRIPTION

[0035] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0036] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0037] In the present application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple, respectively.

[0038] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0039] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0040] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0041] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0042] In the first aspect, the present application provides a polyimide lightweight fireproof composite board, the structure of which is as follows: Figure 1 The composite board comprises a heat insulation layer 1, a first anti-cracking layer 201 and a first exterior layer 301 which are stacked in sequence, and the adjacent layers are bonded by an adhesive layer 4. The heat insulation layer 1 is made of polyimide foam, the first anti-cracking layer 201 is composited by silicone resin and a high-strength and high-modulus mesh layer, and the high-strength and high-modulus mesh layer is a polyimide filament woven mesh layer; the first exterior layer 301 is composited by a multi-layer ceramic matrix carbon fiber prepreg, and the adhesive layer 4 is a polyimide resin layer.

[0043] The first outer decorative layer 301 of the embodiment of the present application is composed of a multi-layer ceramic matrix carbon fiber prepreg. The first outer decorative layer 301 has a high hardness and is difficult to be damaged; the silicone resin inside the first anti-cracking layer 201 has a high resilience performance and a buffering effect under external force impact, so that the overall structural performance of the composite board is further improved, and each layer is a new heat-resistant and fire-proof material. Even if the heating temperature is higher than the limit temperature of each layer of material, the material inside the composite board of the embodiment of the present application is carbonized without afterburning and will not catch fire. The first outer decorative layer 301 of the embodiment of the present application is 15%-30% lighter than the traditional aluminum alloy material. The tensile strength of the outer decorative layer can reach more than 3500MPa, which is 7-9 times that of steel. It is also significantly higher than steel in terms of tensile modulus, and has a high modulus, high hardness, and impact resistance. The thermal expansion coefficient of the outer decorative layer is small, not easy to expand and deform, and has excellent corrosion and aging resistance. Generally, acid, alkali, and salt substances will not affect the outer decorative layer, and no hydrolysis reaction will occur in humid air.

[0044] The composite board of the embodiment of the present application uses polyimide foam as the thermal insulation layer 1. The polyimide foam is inherently flame retardant, environmentally friendly and non-toxic, has a wide temperature tolerance range, low thermal conductivity, radiation resistance, light weight, and can be used under extreme conditions such as ultra-high temperature, ultra-low temperature, high salt fog, strong noise, and strong corrosion. Most of the thermal insulation materials currently used are rock wool, which is 10-30 times heavier than polyimide foam. It has the disadvantages of high weight, easy water absorption and failure, and short service life. Compared with rock wool, polyimide foam as the material of the thermal insulation layer 1 is easier to process and install.

[0045] The first anti-cracking layer 201 of the composite board of the embodiment of the present application is a combination of a high-strength and high-modulus mesh layer and a high-heat-resistant silicone resin, which has high tensile strength, and has the advantages of reducing noise and better wear resistance; in addition, the first anti-cracking layer 201 of the embodiment of the present application has low density, light weight, high strength, high modulus, a long life cycle, anti-aging, no melting droplets when burning, no toxic gas, etc. The silicone resin is set in this layer to increase its surface buffering performance, the high-strength mesh layer protects its internal structure, and disperses and reduces the heat conduction of the first exterior layer 301, making the heat conduction slow and evenly dispersed.

[0046] Polyimide resin is used as an adhesive between the composite board layers in the embodiment of the present application. The polyimide resin has a heat deformation temperature of 360°C under a load of 1.8 MPa, and has excellent electrical properties. It has excellent mechanical properties, electrical insulation properties, radiation resistance, high temperature resistance and wear resistance, good melt fluidity, and a molding shrinkage rate of 0.5%-0.7%. It can be used for injection and extrusion molding. It is used as a bond between layers. It has high toughness, high tensile strength, and a bending strength of 250 MPa. It has excellent affinity for the materials in this plate and excellent bonding properties.

[0047] A polyimide lightweight fireproof composite board according to an embodiment of the present application is provided with a first exterior layer 301 composed of a carbon fiber prepreg of a ceramic matrix and a polyimide foam insulation layer 1, so that the composite board becomes lighter and the heat resistance and fire resistance of the composite board are increased; the embodiment of the present application uses a high-strength and high-modulus mesh layer as the material of the first anti-cracking layer 201, so that the silicone resin of the first anti-cracking layer 201 is distributed more evenly in the high-strength and high-modulus mesh layer, the compressive capacity is greatly improved, and the continuous use temperature is relatively increased. In terms of thermal insulation performance, the thermal conductivity coefficient is lower, the conduction distribution is more uniform, and the thermal conduction speed is slower, thereby improving the overall structural strength and fire resistance and thermal insulation of the composite board; the embodiment of the present application uses a polyimide resin as an adhesive layer 4, and the polyimide resin has a self-extinguishing property when away from fire and has no droplets. Using it as an adhesive reinforcement material between the layers can effectively improve the toughening strength and temperature resistance stability of the composite board, so that the composite board has a higher thermal decomposition temperature, and further improves the flame retardant effect of the composite board.

[0048] Furthermore, countersunk holes are provided on the composite board of the embodiment of the present application, and the countersunk holes are used to drive countersunk nails 5. By driving the countersunk nails 5 into the countersunk holes, the firmness of the connection between the thermal insulation layer 1, the first anti-cracking layer 201 and the first exterior decorative layer 301 can be further improved, so that even if a certain material of the composite board of the embodiment of the present application is damaged due to external reasons, it will not affect the stability of the overall structure of the composite board and its heat-resistant and fire-proof properties.

[0049] Furthermore, a avoidance bin is provided in the thermal insulation layer 1 of the embodiment of the present application, that is, a plurality of holes are opened in the thermal insulation layer 1, and the avoidance bin (holes) are filled with polyimide resin. The avoidance bin can further play a buffering role, thereby improving the structural strength of the composite board when subjected to external force and enhancing its anti-destruction ability.

[0050] Furthermore, the composite board of the embodiment of the present application also includes a second anti-crack layer 202 and a second exterior layer 302, and the second anti-crack layer 202 and the first anti-crack layer 201 are arranged in mirror symmetry with respect to the thermal insulation layer 1; the second exterior layer 302 and the first exterior layer 301 are arranged in mirror symmetry with respect to the thermal insulation layer 1. By symmetrically arranging the anti-crack layer and the exterior layer on the upper and lower sides of the thermal insulation layer 1, the structural strength and fireproof and heat-resistant performance of the composite board can be further improved. The overall thickness of the composite board of the embodiment of the present application is about 6 cm, the thickness of the thermal insulation layer is about 3 cm, the thickness of the anti-crack layer and the exterior layer is about 0.8 cm each, and the thickness of the adhesive layer 4 is 2-4 mm. The anti-crack layer here includes the first anti-crack layer 201 and the second anti-crack layer 202, and the exterior layer includes the first exterior layer 301 and the second exterior layer 302.

[0051] The viscosity of the silicone resin used in the present application is 5-8 Pa.s, and the shear strength is ≥15 kgf / cm 2 , the elongation is 150%.

[0052] The high-strength and high-modulus mesh layer used in the embodiment of the present application is woven from high-strength and high-modulus polyimide filaments. Specifically, it is woven from polyimide filaments according to the warp and weft of 17*17, and has a breaking strength of 3.9-4.4GPa.

[0053] A second aspect of the embodiment of the present application further provides a method for preparing a polyimide lightweight fireproof composite board, comprising the following steps:

[0054] (1) vacuum molding a carbon fiber prepreg of a multilayer ceramic matrix to obtain a first exterior layer;

[0055] (2) coating the organic silicone resin on the front and back surfaces of the high-strength and high-modulus mesh layer, and allowing the organic silicone resin to penetrate into the gaps of the high-strength and high-modulus mesh layer by extrusion to obtain a first anti-cracking layer;

[0056] (3) Using polyimide foam as a thermal insulation layer;

[0057] (4) stacking the first exterior layer, the first anti-cracking layer and the heat insulation layer in sequence, and coating adjacent layers with a polyimide resin adhesive layer for bonding to obtain a composite panel precursor;

[0058] (5) pre-curing the composite board precursor at 120-130° C.;

[0059] (6) The pre-cured board is vacuum cured at 300-320° C. to obtain a composite board.

[0060] When the composite panel of the embodiment of the present application also includes a second anti-crack layer and a second exterior decorative layer, it also includes the step of sequentially bonding and stacking the second anti-crack layer and the second exterior decorative layer on the other side of the thermal insulation layer, and the second anti-crack layer and the first anti-crack layer are arranged in a mirror-symmetrical manner with respect to the thermal insulation layer; the second exterior decorative layer and the first exterior decorative layer are arranged in a mirror-symmetrical manner with respect to the thermal insulation layer.

[0061] In the above step (1), the preparation of the first exterior decorative layer can specifically adopt the following method: select the carbon fiber prepreg of the ceramic matrix, cut the carbon fiber prepreg of the ceramic matrix according to the required size, and determine the number of layers of the carbon fiber prepreg of the ceramic matrix according to the required thickness. The thicker the plate, the more carbon fiber prepreg of the ceramic matrix needs to be stacked. Taking 1mm3K carbon fiber plate as an example, 4 layers of carbon fiber prepreg of the ceramic matrix are required. During preparation, a release agent is coated on the bottom, and a vacuum film is attached to the top of the carbon fiber prepreg of the ceramic matrix. The stacked multi-layer carbon fiber prepreg of the ceramic matrix is ​​placed in a mold and film is closed, and then placed in a press for compression molding. The exterior decorative layer obtained by compression molding closes the mold due to pressure, densifies the material, and is better cured. The carbon fiber prepreg of the ceramic matrix of the embodiment of the present application is a carbon fiber unidirectional prepreg, model 175, purchased from Zhongfu Shenying Carbon Fiber Co., Ltd.

[0062] In the above step (2), the preparation process of the first anti-cracking layer also includes the step of coating a mixture of toluene and alkoxysilane on both sides of the high-strength and high-modulus mesh layer. Furthermore, the mixture contains the following mass percentage components: toluene 65-75%, alkoxysilane 5-10%, 2-propanol 15-25%, tin fatty acid salt ≤5%. By coating the mixture, the vertical and horizontal hardness of the fabric can be ensured, while increasing the bonding strength between the fabric and the resin, reducing the gaps between the vertical and horizontal tows, and controlling the gaps to ≤0.5%, further improving the elastic properties, and then improving the compressive properties of the composite board. In the embodiment of the present application, the coating amount of the silicone resin accounts for 30-45% of the mass of the high-strength and high-modulus polyimide filament mesh layer (warp and weft 17*17 weaving); the coating amount of the mixture accounts for 8-15% of the mass of the high-strength and high-modulus polyimide filament mesh layer (warp and weft 17*17 weaving).

[0063] In the above step (5), the pre-curing time is 0.1-1h; in the above step (6), the vacuum curing time is 0.1-1h.

[0064] A polyimide lightweight fireproof composite board and a preparation method thereof according to an embodiment of the present application are illustrated below through a plurality of specific embodiments.

[0065] Example 1

[0066] Embodiment 1 of the present application provides a polyimide lightweight fireproof composite board and a preparation method thereof, comprising the following steps:

[0067] (1) vacuum molding 15 layers of carbon fiber prepreg with a ceramic matrix to obtain a first outer layer; the same method is used to obtain a second outer layer; the thickness of the first outer layer and the second outer layer are both 2.7 mm;

[0068] (2) Apply silicone resin on both sides of the polyimide filament mesh layer (17*17 weft and longitude), and then apply a mixture of toluene and alkoxysilane, the mixture containing the following components in percentage by weight: 75% toluene, 10% alkoxysilane, and 15% 2-propanol. The amount of silicone resin applied accounts for 35% of the mass of the high-strength and high-modulus polyimide filament mesh layer (17*17 weft and longitude); the amount of the mixture applied accounts for 10% of the mass of the high-strength and high-modulus polyimide filament mesh layer (17*17 weft and longitude). The silicone resin is infiltrated into the gaps of the high-strength and high-modulus mesh layer by extrusion to obtain a first anti-cracking layer; the second anti-cracking layer is obtained by the same method; the thickness of the first anti-cracking layer and the second anti-cracking layer are both 3.7 mm;

[0069] (3) Using 2.6 mm thick polyimide foam as the thermal insulation layer;

[0070] (4) stacking the first exterior layer, the first anti-cracking layer, the heat insulation layer, the second anti-cracking layer and the second exterior layer in sequence, and coating adjacent layers with a polyimide resin adhesive layer for bonding to obtain a composite panel precursor;

[0071] (5) placing the composite plate precursor on a vulcanizer and hot pressing at 120° C. for 10 min for pre-curing, so that the viscosity of the polyimide resin decreases through heat conduction, and the gaps between the layers are reduced and made tight by hot pressing;

[0072] (6) The pre-cured board is placed in an autoclave and vacuum-cured at 300°C for 30 minutes to obtain a composite board.

[0073] Example 2

[0074] Embodiment 2 of the present application provides a polyimide lightweight fireproof composite board and a preparation method thereof, comprising the following steps:

[0075] (1) vacuum molding 18 layers of carbon fiber prepreg with a ceramic matrix to obtain a first outer layer; the same method is used to obtain a second outer layer; the thickness of the first outer layer and the second outer layer are both 3.24 mm;

[0076] (2) Apply silicone resin on both sides of the polyimide filament mesh layer (17*17 weft and longitude), and then apply a mixture of toluene and alkoxysilane, the mixture containing the following components by mass percentage: 75% toluene, 10% alkoxysilane, and 15% 2-propanol. The coating amount of silicone resin accounts for 40% of the mass of the high-strength and high-modulus polyimide filament mesh layer (17*17 weft and longitude); the coating amount of the mixture accounts for 12% of the mass of the high-strength and high-modulus polyimide filament mesh layer (17*17 weft and longitude). The silicone resin is infiltrated into the gaps of the high-strength and high-modulus mesh layer by extrusion to obtain a first anti-cracking layer; the second anti-cracking layer is obtained by the same method; the thickness of the first anti-cracking layer and the second anti-cracking layer are both 3.8 mm;

[0077] (3) Use 2.8 cm thick polyimide foam as the insulation layer;

[0078] (4) stacking the first exterior layer, the first anti-cracking layer, the heat insulation layer, the second anti-cracking layer and the second exterior layer in sequence, and coating adjacent layers with a polyimide resin adhesive layer for bonding to obtain a composite panel precursor;

[0079] (5) placing the composite plate precursor on a vulcanizer and hot pressing at 130° C. for 30 min for pre-curing, so that the viscosity of the polyimide resin is reduced by heat conduction, and the gaps between the layers are reduced and made tight by hot pressing;

[0080] (6) The pre-cured board is placed in an autoclave and vacuum-cured at 320° C. for 30 min to obtain a composite board.

[0081] Example 3

[0082] Embodiment 3 of the present application provides a polyimide lightweight fireproof composite board and a preparation method thereof, comprising the following steps:

[0083] (1) vacuum molding 18 layers of carbon fiber prepreg with a ceramic matrix to obtain a first outer layer; the same method is used to obtain a second outer layer; the thickness of the first outer layer and the second outer layer are both 3.24 mm;

[0084] (2) Apply silicone resin on both sides of the polyimide filament mesh layer (17*17 weft and longitude), and then apply a mixture of toluene and alkoxysilane, the mixture containing the following components by mass percentage: 75% toluene, 10% alkoxysilane, and 15% 2-propanol. The coating amount of silicone resin accounts for 40% of the mass of the high-strength and high-modulus polyimide filament mesh layer (17*17 weft and longitude); the coating amount of the mixture accounts for 12% of the mass of the high-strength and high-modulus polyimide filament mesh layer (17*17 weft and longitude). The silicone resin is infiltrated into the gaps of the high-strength and high-modulus mesh layer by extrusion to obtain a first anti-cracking layer; the second anti-cracking layer is obtained by the same method; the thickness of the first anti-cracking layer and the second anti-cracking layer are both 3.8 mm;

[0085] (3) Use 3 cm thick polyimide foam as the insulation layer;

[0086] (4) stacking the first exterior layer, the first anti-cracking layer, the heat insulation layer, the second anti-cracking layer and the second exterior layer in sequence, and coating adjacent layers with a polyimide resin adhesive layer for bonding to obtain a composite panel precursor;

[0087] (5) placing the composite plate precursor on a vulcanizer and hot pressing at 120° C. for 30 min for pre-curing, so that the viscosity of the polyimide resin decreases through heat conduction, and the gaps between the layers are reduced and made tight by hot pressing;

[0088] (6) The pre-cured board is placed in an autoclave and vacuum-cured at 320° C. for 60 min to obtain a composite board.

[0089] The composite panels prepared in Examples 1 to 3 of the present application were tested according to GB / T 25206.1-2014 Composite sandwich panel building combustion performance test Part 1: Small chamber method, and GB 8624-2012 Combustion performance classification of building materials and products. The test results are shown in the following table.

[0090]

[0091]

[0092] It can be seen from the test data in the above table that the composite panels prepared in the embodiments of the present application all exhibit good compression and tensile resistance, high structural strength, and good heat resistance and fire retardancy.

[0093] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A polyimide lightweight fireproof composite board, characterized in that: The composite board comprises a heat insulation layer, a first anti-cracking layer and a first exterior decoration layer stacked in sequence, and adjacent layers are bonded by an adhesive layer; The heat insulation layer is composed of polyimide foam; The first anti-cracking layer is composited by a silicone resin and a polyimide filament woven mesh layer; The first exterior decorative layer is composited by a multi-layer ceramic matrix carbon fiber prepreg; the multi-layer ceramic matrix carbon fiber prepreg is a carbon fiber unidirectional prepreg; The adhesive layer is a polyimide resin layer.

2. A polyimide lightweight fireproof composite board as claimed in claim 1, characterized in that: The composite plate is provided with countersunk holes, and the countersunk holes are used for driving countersunk nails.

3. A polyimide lightweight fireproof composite board as claimed in claim 1, characterized in that: A refuge chamber is arranged in the heat insulation layer, and the refuge chamber is filled with polyimide resin.

4. A polyimide lightweight fireproof composite board according to any one of claims 1 to 3, characterized in that: It also includes a second anti-crack layer and a second exterior layer, wherein the second anti-crack layer and the first anti-crack layer are arranged in a mirror-symmetrical manner with respect to the heat insulation layer; The second exterior decoration layer and the first exterior decoration layer are arranged in mirror symmetry with respect to the heat insulation layer.

5. A polyimide lightweight fireproof composite board according to any one of claims 1 to 3, characterized in that: The viscosity of the silicone resin is 5-8 pa.s, and the shear strength is ≥15 kgf / cm².

6. A polyimide lightweight fireproof composite board according to any one of claims 1 to 3, characterized in that: The polyimide filament woven mesh layer has a breaking strength of 3.9-4.4 GPa.

7. A method for preparing a polyimide lightweight fireproof composite board, characterized in that: The following steps are involved: The carbon fiber prepreg of the multi-layer ceramic matrix is ​​vacuum molded to obtain a first exterior layer; the carbon fiber prepreg of the multi-layer ceramic matrix is ​​a carbon fiber unidirectional prepreg; The organic silicone resin is coated on both sides of the high-strength and high-modulus mesh layer, and the organic silicone resin is infiltrated into the gaps of the high-strength and high-modulus mesh layer by extrusion to obtain a first anti-cracking layer; the high-strength and high-modulus mesh layer is woven from high-strength and high-modulus polyimide filaments, specifically, the polyimide filaments are woven according to the warp and weft of 17×17, and the breaking strength is 3.9-4.4 Gpa; Use polyimide foam as thermal insulation; The first exterior layer, the first anti-cracking layer and the heat insulation layer are stacked in sequence, and a polyimide resin adhesive layer is applied between adjacent layers for bonding to obtain a composite board precursor; Pre-curing the composite board precursor at 120-130° C.; The pre-cured board is vacuum cured at 300-320° C. to obtain a composite board.

8. The method for preparing a polyimide lightweight fireproof composite board according to claim 7, characterized in that: The preparation process of the first anti-cracking layer also includes the step of coating a mixture of toluene and alkoxysilane on both sides of the high-strength and high-modulus mesh layer.

9. The method for preparing a polyimide lightweight fireproof composite board according to claim 8, characterized in that: The mixture contains the following components in percentage by mass: 65-75% toluene, 5-10% alkoxysilane, 15-25% 2-propanol, and ≤5% tin fatty acid salt.

10. The method for preparing a polyimide lightweight fireproof composite board according to claim 7, characterized in that: The pre-curing time is 0.1-1 h; and / or, the vacuum curing time is 0.1-1 h.

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