A lightweight polyimide thermal insulation board and its preparation method

Abstract

The present invention discloses a lightweight polyimide thermal insulation board and a preparation method thereof. The lightweight polyimide thermal insulation board is characterized in that: the lightweight polyimide thermal insulation board is made by hot-pressing multiple layers of overlapping modified polyimide thermal insulation resin fiber fabric prepreg; the modified polyimide thermal insulation resin fiber fabric prepreg is obtained by coating a modified polyimide thermal insulation resin adhesive on an aramid fiber fabric and then baking it; the modified polyimide thermal insulation resin adhesive is composed of a mixture of 100 parts by weight of a polyimide resin, 15 to 35 parts by weight of an organosilicon resin, 5 to 35 parts by weight of a nano-modifier, 0.04 to 0.13 parts by weight of a modifying treatment agent, 0.005 to 0.1 parts by weight of an accelerator, and 50 to 200 parts by weight of a solvent. The lightweight polyimide thermal insulation board of the present invention has the characteristics of light weight, low thermal conductivity, high mechanical strength, high mechanical toughness, and high flame retardancy, and is suitable for use in transportation, building insulation, energy industry, and other fields.

Description

Technical Field

[0001] This invention relates to laminated panels and their preparation, specifically to a lightweight polyimide insulation board and its preparation method. The lightweight polyimide insulation board is suitable for use in transportation, building insulation, the energy industry, and other fields, and is particularly suitable as a lightweight insulation material for new energy vehicles, lithium battery packs, and submarine pipeline transportation. Background Art

[0002] Thermal insulation materials are materials or composites that have insulating properties and act as a shield against heat flow. They are typically lightweight, loose, porous, and have low thermal conductivity. They are widely used in industry to prevent heat loss from thermal equipment and pipelines, or in freezing and low-temperature conditions, hence the name "heat or cold insulation." Their porous or fibrous structure provides excellent sound absorption, making them widely used in the construction industry. Lightweight thermal insulation materials are a new type of material that is lightweight, efficient, energy-efficient, and environmentally friendly. Their widespread application will help reduce energy consumption, minimize environmental pollution, and improve economic and social benefits. They are widely used in transportation, building insulation, the energy industry, and other fields.

[0003] Thermal runaway is the leading cause of power battery pack safety accidents. At high energy densities, battery fire or explosion can occur due to factors such as batch consistency, inherent thermal stability of the materials, compatibility between battery components, and the highly flammable electrolyte. After a single battery cell experiences thermal runaway, the battery system must remain fire- and explosion-free for five minutes. Achieving a "five-minute safe escape time" requires further improvements to the battery pack's insulation materials to delay the explosion of faulty battery packs. With the continued rapid growth of China's new energy vehicle and lithium battery energy storage markets, demand for thermal management, flame-retardant, and insulation materials for lithium batteries is poised to surge.

[0004] To keep pace with the trend toward increasingly compact battery packs in terms of overall volume and weight, lithium battery manufacturers are placing revolutionary demands on the separators used in their battery pack designs. These demands require continuous optimization of the battery pack's volumetric energy density. Besides ensuring overall lightness (low density), high energy efficiency (low thermal conductivity), and high safety (flame retardancy), these separators must also possess excellent support strength, deformation resistance (mechanical strength), insulation properties (electrical strength), and thinner sheet thicknesses (0.5mm or greater). These requirements are unattainable with existing foam materials, which have low mechanical strength and large thickness. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and provide a lightweight polyimide insulation board and a preparation method thereof.3 ~1.75g / cm 3 ), high thermal insulation (thermal conductivity (25°C) less than 0.2w / m·k), high strength (flexural strength of 380MPa~450MPa, tensile strength of 365MPa~387MPa), high heat resistance (flexural strength at 180°C 267MPa~331MPa), high toughness (notched impact strength of 60KJ / m 2 ~70KJ / m 2 ), excellent insulation (insulation resistance greater than or equal to 10 8 The invention relates to a lightweight polyimide heat-insulating board with high thermal conductivity (MΩ), flame retardancy (reaching UL94 V-0 grade) and thin board thickness (which can be greater than or equal to 0.5 mm) and a preparation method thereof.

[0006] The present invention provides a lightweight polyimide thermal insulation board, characterized in that the lightweight polyimide thermal insulation board is formed by hot pressing multiple layers of overlapping modified polyimide thermal insulation resin fiber fabric prepreg (the number of layers of the modified polyimide thermal insulation resin fiber fabric prepreg is not limited and can be 1-500 layers as required);

[0007] The modified polyimide thermal insulation resin fiber fabric prepreg is obtained by coating a modified polyimide thermal insulation resin adhesive on an aramid fiber fabric and then baking the prepreg.

[0008] The modified polyimide thermal insulation resin adhesive is composed of 100 parts by weight of polyimide resin, 15-35 parts by weight of silicone resin, 5-35 parts by weight of nano-modifier, 0.04-0.13 parts by weight of modification treatment agent, 0.005-0.1 parts by weight of accelerator and 50-200 parts by weight of solvent.

[0009] The aramid fiber fabric is at least one of aramid fiber plain fabric, aramid fiber twill fabric, aramid fiber gingham fabric, aramid fiber multi-axial fabric, and aramid fiber composite fabric (the aramid fiber fabric is produced and provided by the following companies and product models (brands): AK-200P, AK-240P of Hephaestus Protection Technology (Guangdong) Co., Ltd., Kevlar fabric of Guangdong Teweilong New Materials Application Co., Ltd., etc.).

[0010] In the modified polyimide thermal insulation resin adhesive of the present invention:

[0011] The polyimide resin is polyimide resin powder [the polyimide resin powder is produced by the following companies and product models (brands): PIPower-I of Lilo Group, PI powder of Wuhan Zhisheng Technology Co., Ltd., etc.];

[0012] The organic silicone resin [the production and supply enterprises and product models (brands) of the organic silicone resin include: SI-101 of Laiyang Shengbang Organic Silicone Technology Co., Ltd., KR-271 of Shin-Etsu Chemical Co., Ltd. of Japan, SM1153D of Sanmu Group, etc.];

[0013] The nano-modifier is one or a mixture of two of fumed silica [the production and supply companies and product models (brands) of the fumed silica include: TT 1000 granulate of Suzhou Unico Insulation Technology Co., Ltd.] and hollow glass microspheres [the production and supply companies and product models (brands) of the hollow glass microspheres include: C-40 of Zhongke Huaxing New Materials Co., Ltd., S4630 of 3M Company, etc.];

[0014] The modifying agent is any one of 3-aminopropyltriethoxysilane [the production and product models (trademarks) of the 3-aminopropyltriethoxysilane include: Shandong Tianming Biotechnology Development Co., Ltd., Shandong Xiya Chemical Co., Ltd., Linyi Azeroth Biotechnology Co., Ltd., etc.], 3-glycidyloxypropyltrimethoxysilane [the production and product models (trademarks) of the 3-glycidyloxypropyltrimethoxysilane include: Hubei Yongkuo Technology Co., Ltd., Nantong Runfeng Petrochemical Co., Ltd., Guangdong Wengjiang Chemical Reagent Co., Ltd., etc.], γ-aminopropyltriethoxysilane [the production and product models (trademarks) of the γ-aminopropyltriethoxysilane include: Hangzhou Jessica Chemical Co., Ltd., Henan Wanshan New Materials Technology Co., Ltd., etc.], and γ-glycidyloxypropyltrimethoxysilane [the production and product models (trademarks) of the γ-glycidyloxypropyltrimethoxysilane include: Henan Xinpeng Chemical Products Co., Ltd., Henan Xiye Chemical Co., Ltd., etc.] or a mixture of two or more thereof;

[0015] The accelerator is any one of imidazole [the production and product models (trademarks) of the imidazole include: 2-methylimidazole of Linyi Mingpin Chemical Co., Ltd., N,N'-carbonyldiimidazole of Shanghai Nuotai Chemical Co., Ltd., etc.], diaminodiphenylmethane [the production and product models (trademarks) of the diaminodiphenylmethane include: Wuhan Zhisheng Technology Co., Ltd., Zhangjiagang Yarui Chemical Co., Ltd., Guangzhou Yangming Chemical Technology Co., Ltd., etc.], and boron trifluoride ethylamine [the production and product models (trademarks) of boron trifluoride ethylamine include: Beijing Xinao Xunchi Chemical Co., Ltd., Nanjing Chemical Reagent Co., Ltd., etc.] or a mixture of two or more thereof;

[0016] The solvent is any two of acetone [the acetone production and supply enterprises and product models (trademarks) include: Jinan Daliang Chemical Co., Ltd., Kunshan Minglong Chemical Co., Ltd.], butanone [the butanone production and supply enterprises and product models (trademarks) include: Langfang Jinhai Chemical Co., Ltd., Shandong Qixing Chemical Co., Ltd., etc.], N,N-dimethylformamide [the N,N-dimethylformamide production and supply enterprises and product models (trademarks) include: Dongguan Nanjian Fine Chemical Co., Ltd., Guangzhou Futuo Trading Co., Ltd., etc.] and a mixture of two or more thereof.

[0017] In the content of the present invention: the hot pressing molding is: after preheating the template at 145°C to 175°C, the modified polyimide insulation resin fiber fabric prepreg is overlapped (including matching and laminating) and placed in the template, and after closing the mold, it is hot pressed under the conditions of temperature 210°C to 220°C and pressure 1MPa to 25MPa, and the hot pressing time is 0.5h to 50h (h means hours, the same below).

[0018] In the content of the present invention: the baking is: placing the aramid fiber fabric coated with a modified polyimide thermal insulation resin adhesive (by a gluing machine) into a drying tunnel, the drying tunnel is 50m long and divided into 4 sections, each section is 12.5m, the baking temperature range is 100°C to 185°C, wherein: the first section is 105°C to 125°C, the second section is 135°C to 165°C, the third section is 165°C to 185°C, and the fourth section is 100°C to 110°C, and the speed of the gluing machine is 10m / min to 25m / min.

[0019] In the content of the present invention: the preparation method of the modified polyimide thermal insulation resin adhesive is: at a temperature of 50°C to 85°C, the nano-modifier, the modification treatment agent, the polyimide resin and the silicone resin are stirred and mixed at a speed of 800r / min to 1500r / min, and stirred for 3h to 5h to prepare a modified resin for standby use. After cooling to room temperature, a solvent and a promoter are added and stirred. The resin molding time is tested at 180°C for 150s to 300s (s means seconds, the same below), and the modified polyimide thermal insulation resin adhesive is obtained.

[0020] In the content of the present invention: in the modified polyimide thermal insulation resin fiber fabric prepreg: the weight percentage of the (semi-cured) modified polyimide thermal insulation resin adhesive is 30% to 50%, and the weight percentage of the aramid fiber fabric is 50% to 70%.

[0021] In the context of the present invention: the lightweight polyimide insulation board has a light weight (density of 1.55g / cm 3 ~1.75g / cm 3), high thermal insulation (thermal conductivity (25°C) less than 0.2w / m·k), high strength (flexural strength of 380MPa~450MPa, tensile strength of 365MPa~387MPa), high heat resistance (flexural strength at 180°C 267MPa~331MPa), high toughness (notched impact strength of 60KJ / m 2 ~70KJ / m 2 ), excellent insulation (insulation resistance greater than or equal to 10 8 The invention relates to a lightweight polyimide thermal insulation board having the characteristics of high thermal conductivity (MΩ), flame retardancy (reaching UL94 V-0 grade) and thin board thickness (which can be greater than or equal to 0.5 mm) and a preparation method thereof.

[0022] Another aspect of the present invention is a method for preparing a lightweight polyimide insulation board, which is characterized by comprising the following steps:

[0023] a. Ingredients: Prepare the raw materials of each component according to the ratio of 100 parts by weight of polyimide resin, 15-35 parts by weight of silicone resin, 5-35 parts by weight of nano-modifier, 0.04-0.13 parts by weight of modification treatment agent, 0.005-0.1 parts by weight of accelerator and 50-200 parts by weight of solvent;

[0024] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 50° C. to 85° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin are stirred and mixed at a speed of 800 r / min to 1500 r / min, and stirred for 3 h to 5 h to prepare a modified resin for standby use. After cooling to room temperature, a solvent and a accelerator are added and stirred. The resin molding time is tested to be 150 s to 300 s at 180° C. to obtain a modified polyimide thermal insulation resin adhesive;

[0025] c. Preparing a modified polyimide thermal insulation resin fiber fabric prepreg: coating the modified polyimide thermal insulation resin adhesive prepared in step b on an aramid fiber fabric, and then baking to obtain a modified polyimide thermal insulation resin fiber fabric prepreg;

[0026] The aramid fiber fabric is at least one of aramid fiber plain cloth, aramid fiber twill cloth, aramid fiber woven cloth, aramid fiber multiaxial cloth, and aramid fiber composite cloth;

[0027] d. Preparation of lightweight polyimide insulation board: preheating the template at 145°C to 175°C, overlapping the modified polyimide insulation resin fiber fabric prepreg and placing it in the template, closing the mold and hot pressing it at a temperature of 210°C to 220°C and a pressure of 1MPa to 25MPa for 0.5h to 50h to obtain a lightweight polyimide insulation board.

[0028] In another aspect of the present invention, the baking step is to place the aramid fiber fabric coated with a modified polyimide thermal insulation resin adhesive (through a gluing machine) into a drying tunnel, the drying tunnel being 50 m long and divided into four sections, each 12.5 m long. The baking temperature range is 100° C. to 185° C., wherein the first section is 105° C. to 125° C., the second section is 135° C. to 165° C., the third section is 165° C. to 185° C., and the fourth section is 100° C. to 110° C. The speed of the gluing machine is 10 m / min to 25 m / min.

[0029] Another aspect of the present invention relates to a method for preparing a lightweight polyimide thermal insulation board, wherein the ingredients in step a are:

[0030] The polyimide resin is polyimide resin powder [the polyimide resin powder is produced by the following companies and product models (brands): PIPower-I of Lilo Group, PI powder of Wuhan Zhisheng Technology Co., Ltd., etc.];

[0031] The organic silicone resin [the production and supply enterprises and product models (brands) of the organic silicone resin include: SI-101 of Laiyang Shengbang Organic Silicone Technology Co., Ltd., KR-271 of Shin-Etsu Chemical Co., Ltd. of Japan, SM1153D of Sanmu Group, etc.];

[0032] The nano-modifier is one or a mixture of two of fumed silica [the production and supply companies and product models (brands) of the fumed silica include: TT 1000 granulate of Suzhou Unico Insulation Technology Co., Ltd.] and hollow glass microspheres [the production and supply companies and product models (brands) of the hollow glass microspheres include: C-40 of Zhongke Huaxing New Materials Co., Ltd., S4630 of 3M Company, etc.];

[0033] The modifying agent is any one of 3-aminopropyltriethoxysilane [the production and product models (trademarks) of the 3-aminopropyltriethoxysilane include: Shandong Tianming Biotechnology Development Co., Ltd., Shandong Xiya Chemical Co., Ltd., Linyi Azeroth Biotechnology Co., Ltd., etc.], 3-glycidyloxypropyltrimethoxysilane [the production and product models (trademarks) of the 3-glycidyloxypropyltrimethoxysilane include: Hubei Yongkuo Technology Co., Ltd., Nantong Runfeng Petrochemical Co., Ltd., Guangdong Wengjiang Chemical Reagent Co., Ltd., etc.], γ-aminopropyltriethoxysilane [the production and product models (trademarks) of the γ-aminopropyltriethoxysilane include: Hangzhou Jessica Chemical Co., Ltd., Henan Wanshan New Materials Technology Co., Ltd., etc.], and γ-glycidyloxypropyltrimethoxysilane [the production and product models (trademarks) of the γ-glycidyloxypropyltrimethoxysilane include: Henan Xinpeng Chemical Products Co., Ltd., Henan Xiye Chemical Co., Ltd., etc.] or a mixture of two or more thereof;

[0034] The accelerator is any one of imidazole [the production and product models (trademarks) of the imidazole include: 2-methylimidazole of Linyi Mingpin Chemical Co., Ltd., N,N'-carbonyldiimidazole of Shanghai Nuotai Chemical Co., Ltd., etc.], diaminodiphenylmethane [the production and product models (trademarks) of the diaminodiphenylmethane include: Wuhan Zhisheng Technology Co., Ltd., Zhangjiagang Yarui Chemical Co., Ltd., Guangzhou Yangming Chemical Technology Co., Ltd., etc.], and boron trifluoride ethylamine [the production and product models (trademarks) of boron trifluoride ethylamine include: Beijing Xinao Xunchi Chemical Co., Ltd., Nanjing Chemical Reagent Co., Ltd., etc.] or a mixture of two or more thereof;

[0035] The solvent is any two or more of acetone [the acetone production and supply enterprises and product models (trademarks) include: Jinan Daliang Chemical Co., Ltd., Kunshan Minglong Chemical Co., Ltd.], butanone [the butanone production and supply enterprises and product models (trademarks) include: Langfang Jinhai Chemical Co., Ltd., Shandong Qixing Chemical Co., Ltd., etc.], and N,N-dimethylformamide [the N,N-dimethylformamide production and supply enterprises and product models (trademarks) include: Dongguan Nanjian Fine Chemical Co., Ltd., Guangzhou Futuo Trading Co., Ltd., etc.] or a mixture of two or more.

[0036] In another aspect of the present invention, the performance parameters of the prepared lightweight polyimide insulation board are: bending strength of 380MPa~450MPa at room temperature, bending strength of 267MPa~331MPa at 180℃, tensile strength of 365MPa~387MPa, notched impact strength of 60KJ / m 2 ~70KJ / m 2 , insulation resistance is greater than or equal to 10 8 MΩ, flame retardancy reaches UL94 V-0 level, thermal conductivity (25℃) is less than 0.2w / m·k, density is 1.55g / cm 3 ~1.75g / cm 3 The thickness of the plate is thin (may be greater than or equal to 0.5 mm).

[0037] In another aspect of the present invention: in the modified polyimide thermal insulation resin fiber fabric prepreg described in step c: the weight percentage of the modified polyimide thermal insulation resin adhesive is 30% to 50%, and the weight percentage of the aramid fiber fabric is 50% to 70%.

[0038] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0039] (1) The lightweight polyimide thermal insulation board of the present invention uses polyimide resin and silicone resin as the matrix, supplemented by modified resin and nano-modifier to improve the overall microscopic topological structure of the system. On the basis of simple medium and low temperature modification and grafting, supplemented by high-performance aramid fiber fabric, the laminate is made to have excellent halogen-free flame retardancy and insulation, especially high temperature resistance, low thermal conductivity and excellent impact toughness, thereby obtaining a lightweight thermal insulation board with excellent comprehensive performance;

[0040] (2) The present invention uses a mixed resin (such as polyimide resin, silicone resin) as the matrix and uses ultrafine nano-inorganic materials with a smaller mass ratio (which can be: accounting for greater than or equal to 3.7% of the total mass of the matrix resin) for modification, replacing the usual organic foaming agent foaming to improve thermal insulation, and achieves better thermal insulation performance (thermal conductivity at 25°C reaches 0.122w / m·k0.136w / m·k) than common hard insulation boards (usually, the thermal conductivity at 25°C is greater than or equal to 0.45w / m·k). At the same time, it also effectively solves the problem of the thick thickness of existing common organic or inorganic foamed boards (usually greater than or equal to 8mm), and achieves a thickness range of greater than or equal to 0.5mm for thermal insulation boards, making them more widely used in electronic appliances and industries with high requirements for product intensiveness;

[0041] (3) The present invention makes full use of the combined effect of the dilution effect of the self-released gas and its own heat covering effect when the material is heated and burned, and achieves a highly effective flame retardant effect (reaching UL94V-0) without adding any flame retardant additives. It breaks through the problem that the existing common foaming materials are easy to burn and have thick smoke when burning, and meets the urgent requirements of my country for the "green" development of modern industry. At the same time, the present invention also solves the industry consensus that the addition of flame retardant additives significantly reduces the mechanical strength of the material, especially its temperature resistance, and produces a new type of thermal insulation material with excellent comprehensive performance (excellent mechanical strength, which can refer to the bending strength at 23℃±2℃ reaching 380MPa450MPa, the bending strength at 180℃±2℃ reaching 267MPa331MPa, that is: the bending strength retention rate at 180℃±2℃ is greater than or equal to 70%, and the thermal conductivity at 25℃ reaches 0.122w / m·k0.136w / m·k);

[0042] (4) The present invention uses aramid fiber fabric instead of common glass fiber, which ensures that the board has low thermal conductivity while achieving excellent mechanical strength, especially impact toughness (which can be: impact strength, notched specimen, up to 60KJ / m 2 70KJ / m 2Solve the problem that adding rubber elastomer additives often reduces the overall mechanical strength and heat resistance of the material (for example, as described in "The Effect of Toughening Agents on the Properties of Epoxy Resins" by Ma Tianxin and Jiang Bo);

[0043] (5) In the preparation process of the modified polyimide thermal insulation resin adhesive of the lightweight polyimide thermal insulation board of the present invention, the raw materials are gradually added by a medium-low temperature synthesis reaction method, and stirred and mixed at medium-low temperature to obtain a uniform modified polyimide thermal insulation resin adhesive that meets the prepreg preparation process; and the preparation process is simple, with low requirements on production equipment and operators, which can better meet my country's requirements for "green, environmentally friendly, and efficient" production of enterprises, and greatly reduce production costs, simplify processes, and improve quality. It has significant practical use value and application prospects;

[0044] (6) The present invention adopts a compound resin (polyimide resin combined with silicone resin) as the main resin, and then impregnates the aramid fiber fabric after modification, thereby obtaining a fabric with better thermal insulation (the thermal conductivity coefficient at 25°C can be 0.122w / m·k0.136w / m·k), good mechanical strength, insulation and flame retardancy, and especially better impact toughness (the impact strength under the notch can be 60KJ / m 2 ~70KJ / m 2 ), low density (density can be 1.55g / cm 3 ~1.75g / cm 3 ) characteristics of a new type of thermal insulation material; at the same time, the present invention also solves the problem of adding less inorganic modifier (specifically, the inorganic modifier can account for 3.7% or more of the total amount of the base resin), avoiding the problems of poor mechanical strength of the board (especially in terms of toughness) and difficulty in mixing and stirring the resin raw materials, which makes it difficult for the resin glue to evenly impregnate the fibers, ultimately affecting the quality stability of the board;

[0045] (7) The product of the present invention has a simple preparation process, simple procedures, easy operation and strong practicality. DETAILED DESCRIPTION

[0046] The following embodiments are intended to further illustrate the present invention, but should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0047] In the following Examples 1-19, the specific unit of "parts by weight" is "gram".

[0048] Example 1:

[0049] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0050] a. Ingredients: prepare 100 parts by weight of polyimide resin, 17 parts by weight of silicone resin, 7 parts by weight of nano-modifier (hollow glass microspheres), 0.052 parts by weight of modifying agent (3-glycidyloxypropyltrimethoxysilane), 0.008 parts by weight of accelerator (imidazole) and solvent (40 parts by weight of N,N-dimethylformamide and 27 parts by weight of butanone);

[0051] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 75° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 950 r / min, and stirred for 3.25 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 282 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0052] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0053] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0054] Example 2:

[0055] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0056] a. Ingredients: prepare 100 parts by weight of polyimide resin, 18 parts by weight of silicone resin, 5 parts by weight of nano-modifier (fumed silica), 0.07 parts by weight of modifying agent (3-aminopropyltriethoxysilane), 0.005 parts by weight of accelerator (diaminodiphenylmethane), and solvent (39 parts by weight of N,N-dimethylformamide, 39 parts by weight of butanone);

[0057] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 65° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 800 r / min, and stirred for 3.15 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested at 180° C. for 265 seconds to obtain a modified polyimide thermal insulation resin adhesive;

[0058] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0059] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0060] Example 3:

[0061] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0062] a. Ingredients: prepare 100 parts by weight of polyimide resin, 16 parts by weight of silicone resin, 11 parts by weight of nano-modifier (fumed silica), 0.04 parts by weight of modifying agent (γ-aminopropyltriethoxysilane), 0.012 parts by weight of accelerator (boron trifluoride ethylamine) and solvent (20 parts by weight of acetone, 30 parts by weight of butanone);

[0063] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 60° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 900 r / min, and stirred for 3 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 249 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0064] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0065] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0066] Example 4:

[0067] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0068] a. Ingredients: prepare 100 parts by weight of polyimide resin, 15 parts by weight of silicone resin, 9 parts by weight of nano-modifier (hollow glass microspheres), 0.06 parts by weight of modification agent (γ-glycidyloxypropyltrimethoxysilane), 0.015 parts by weight of accelerator (boron trifluoride ethylamine) and solvent (25 parts by weight of butanone, 64 parts by weight of N,N-dimethylformamide);

[0069] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 50° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 850 r / min, and stirred for 3.25 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 216 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0070] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0071] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0072] Example 5:

[0073] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0074] a. Ingredients: prepare 100 parts by weight of polyimide resin, 22 parts by weight of silicone resin, 15 parts by weight of nano-modifier (fumed silica), 0.052 parts by weight of modifying agent (3-aminopropyltriethoxysilane and 0.041 parts by weight of 3-glycidoxypropyltrimethoxysilane), 0.019 parts by weight of accelerator (imidazole), and solvent (33 parts by weight of acetone and 60 parts by weight of N,N-dimethylformamide);

[0075] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 70° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1050 r / min, and stirred for 3.65 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 273 seconds at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0076] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0077] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0078] Example 6:

[0079] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0080] a. Ingredients: prepare 100 parts by weight of polyimide resin, 21 parts by weight of silicone resin, 12 parts by weight of nano-modifier (hollow glass microspheres), modifying agent (0.023 parts by weight of γ-aminopropyltriethoxysilane and 0.05 parts by weight of 3-aminopropyltriethoxysilane), 0.021 parts by weight of accelerator (imidazole) and solvent (10 parts by weight of N,N-dimethylformamide and 92 parts by weight of acetone);

[0081] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 55° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1150 r / min, and stirred for 4.15 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 258 s at 180° C. to obtain a modified polyimide thermal insulation resin adhesive;

[0082] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0083] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0084] Example 7:

[0085] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0086] a. Ingredients: prepare 100 parts by weight of polyimide resin, 19 parts by weight of silicone resin, 17 parts by weight of nano-modifier (fumed silica), 0.035 parts by weight of modifying agent (γ-glycidyloxypropyltrimethoxysilane and 0.041 parts by weight of 3-aminopropyltriethoxysilane), 0.029 parts by weight of accelerator (diaminodiphenylmethane), and solvent (77 parts by weight of acetone and 32 parts by weight of N,N-dimethylformamide);

[0087] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 72° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1000 r / min. After stirring for 4 hours, a modified resin was prepared for standby use. After cooling to room temperature, a solvent and a accelerator were added and stirred. The resin molding time was tested to be 262 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0088] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0089] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0090] Example 8:

[0091] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0092] a. Ingredients: prepare 100 parts by weight of polyimide resin, 26 parts by weight of silicone resin, 16 parts by weight of nano-modifier (fumed silica), 0.012 parts by weight of modifying agent (0.1 parts by weight of γ-glycidyloxypropyltrimethoxysilane and 0.1 parts by weight of 3-glycidyloxypropyltrimethoxysilane), 0.026 parts by weight of accelerator (diaminodiphenylmethane), and solvent (74 parts by weight of acetone and 42 parts by weight of butanone);

[0093] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 65° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1150 r / min, and stirred for 4.25 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 209 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0094] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0095] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0096] Example 9:

[0097] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0098] a. Ingredients: prepare 100 parts by weight of polyimide resin, 23 parts by weight of silicone resin, 19 parts by weight of nano-modifier (hollow glass microspheres), modifying agent (0.033 parts by weight of γ-aminopropyltriethoxysilane and 0.05 parts by weight of 3-glycidyloxypropyltrimethoxysilane), 0.035 parts by weight of accelerator (boron trifluoride ethylamine) and solvent (81 parts by weight of N,N-dimethylformamide and 38 parts by weight of butanone);

[0099] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 58° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1200 r / min. After stirring for 3.5 hours, a modified resin was prepared for standby use. After cooling to room temperature, a solvent and a accelerator were added and stirred. The resin molding time was tested to be 184 s at 180° C., thereby obtaining a modified polyimide thermal insulation resin adhesive;

[0100] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0101] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0102] Example 10:

[0103] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0104] a. Ingredients: prepare 100 parts by weight of polyimide resin, 28 parts by weight of silicone resin, nano-modifier (8 parts by weight of fumed silica and 10 parts by weight of hollow glass microspheres), modifying agent (0.009 parts by weight of γ-aminopropyltriethoxysilane and 0.082 parts by weight of γ-glycidyloxypropyltrimethoxysilane), accelerator (0.016 parts by weight of imidazole and 0.016 parts by weight of boron trifluoride ethylamine) and solvent (86 parts by weight of acetone and 41 parts by weight of N,N-dimethylformamide);

[0105] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 67° C., the nano-modifier, modifying agent, polyimide resin and silicone resin were stirred and mixed at a speed of 1100 r / min, and stirred for 4.45 hours to prepare a modified resin for standby use. After cooling to room temperature, a solvent and a accelerator were added and stirred. The resin molding time was tested to be 192 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0106] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0107] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0108] Example 11:

[0109] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0110] a. Ingredients: prepare 100 parts by weight of polyimide resin, 25 parts by weight of silicone resin, nano-modifier (3 parts by weight of hollow glass microspheres and 20 parts by weight of fumed silica), modifying agent (0.022 parts by weight of 3-glycidoxypropyltrimethoxysilane and 0.067 parts by weight of 3-aminopropyltriethoxysilane), accelerator (0.04 parts by weight of imidazole and 0.004 parts by weight of diaminodiphenylmethane) and solvent (90 parts by weight of acetone and 45 parts by weight of butanone);

[0111] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 63° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1300 r / min. After stirring for 3.75 hours, a modified resin was prepared for standby use. After cooling to room temperature, a solvent and a accelerator were added and stirred. The resin molding time was tested to be 211 seconds at 180° C., thereby obtaining a modified polyimide thermal insulation resin adhesive;

[0112] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0113] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0114] Example 12:

[0115] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0116] a. Ingredients: prepare 100 parts by weight of polyimide resin, 30 parts by weight of silicone resin, nano-modifier (12 parts by weight of hollow glass microspheres and 8 parts by weight of fumed silica), modification treatment agent (0.008 parts by weight of 3-aminopropyltriethoxysilane and 0.071 parts by weight of γ-glycidyloxypropyltrimethoxysilane), accelerator (0.024 parts by weight of diaminodiphenylmethane and 0.017 parts by weight of boron trifluoride ethylamine) and solvent (62 parts by weight of acetone and 82 parts by weight of N,N-dimethylformamide);

[0117] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 54° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1450 r / min, and stirred for 4.15 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 268 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0118] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0119] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0120] Example 13:

[0121] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0122] a. Ingredients: prepare 100 parts by weight of polyimide resin, 27 parts by weight of silicone resin, nano-modifier (19 parts by weight of fumed silica and 6 parts by weight of hollow glass microspheres), modifying agent (0.019 parts by weight of 3-aminopropyltriethoxysilane and 0.077 parts by weight of γ-aminopropyltriethoxysilane), accelerator (0.037 parts by weight of boron trifluoride ethylamine and 0.016 parts by weight of diaminodiphenylmethane) and solvent (52 parts by weight of butanone, 52 parts by weight of acetone and 52 parts by weight of N,N-dimethylformamide);

[0123] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 74° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1350 r / min, and stirred for 4.45 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 226 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0124] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0125] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0126] Example 14:

[0127] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0128] a. Ingredients: prepare 100 parts by weight of polyimide resin, 33 parts by weight of silicone resin, nano-modifier (9.5 parts by weight of hollow glass microspheres and 17.5 parts by weight of fumed silica), modification treatment agent (0.054 parts by weight of γ-aminopropyltriethoxysilane and 0.061 parts by weight of γ-glycidyloxypropyltrimethoxysilane), accelerator (0.034 parts by weight of boron trifluoride ethylamine and 0.023 parts by weight of imidazole) and solvent (28 parts by weight of butanone, 48 parts by weight of acetone and 91 parts by weight of N,N-dimethylformamide);

[0129] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 80° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1400 r / min, and stirred for 5 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested at 180° C. for 300 seconds to obtain a modified polyimide thermal insulation resin adhesive;

[0130] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0131] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0132] Example 15:

[0133] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0134] a. Ingredients: prepare 100 parts by weight of polyimide resin, 31 parts by weight of silicone resin, nano-modifier (18 parts by weight of fumed silica and 12 parts by weight of hollow glass microspheres), modifying agent (0.038 parts by weight of 3-glycidyloxypropyltrimethoxysilane and 0.075 parts by weight of γ-glycidyloxypropyltrimethoxysilane), accelerator (0.035 parts by weight of imidazole and 0.03 parts by weight of diaminodiphenylmethane) and solvent (48 parts by weight of butanone, 72 parts by weight of acetone and 53 parts by weight of N,N-dimethylformamide);

[0135] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 85° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1500 r / min. After stirring for 3.25 hours, a modified resin was prepared for standby use. After cooling to room temperature, a solvent and a accelerator were added and stirred. The resin molding time was tested to be 225 seconds at 180° C. to obtain a modified polyimide thermal insulation resin adhesive;

[0136] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0137] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0138] Example 16:

[0139] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0140] a. Ingredients: prepare 100 parts by weight of polyimide resin, 35 parts by weight of silicone resin, nano-modifier (11 parts by weight of fumed silica and 20 parts by weight of hollow glass microspheres), modifying agent (0.024 parts by weight of 3-glycidoxypropyltrimethoxysilane and 0.095 parts by weight of γ-aminopropyltriethoxysilane), accelerator (0.05 parts by weight of imidazole and 0.023 parts by weight of diaminodiphenylmethane) and solvent (81 parts by weight of butanone, 62 parts by weight of acetone and 46 parts by weight of N,N-dimethylformamide);

[0141] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 83° C., the nano-modifier, modifying agent, polyimide resin and silicone resin were stirred and mixed at a speed of 1350 r / min, and stirred for 4.65 h to prepare a modified resin for standby use. After cooling to room temperature, a solvent and a accelerator were added and stirred. The resin molding time was tested to be 234 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0142] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0143] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0144] Example 17:

[0145] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0146] a. Ingredients: prepare 100 parts by weight of polyimide resin, 32 parts by weight of silicone resin, nano-modifier (17 parts by weight of hollow glass microspheres and 17 parts by weight of fumed silica), modifying agent (0.03 parts by weight of 3-aminopropyltriethoxysilane, 0.05 parts by weight of 3-glycidoxypropyltrimethoxysilane and 0.05 parts by weight of γ-aminopropyltriethoxysilane), accelerator (0.041 parts by weight of boron trifluoride ethylamine and 0.041 parts by weight of diaminodiphenylmethane) and solvent (61 parts by weight of butanone, 32 parts by weight of acetone and 107 parts by weight of N,N-dimethylformamide);

[0147] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 76° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1450 r / min, and stirred for 4.15 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 276 s at 180° C. to obtain a modified polyimide thermal insulation resin adhesive;

[0148] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0149] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0150] Example 18:

[0151] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0152] a. Ingredients: prepare 100 parts by weight of polyimide resin, 30 parts by weight of silicone resin, nano-modifier (15 parts by weight of fumed silica and 20 parts by weight of hollow glass microspheres), modifying agent (0.016 parts by weight of 3-glycidyloxypropyltrimethoxysilane, 0.014 parts by weight of γ-aminopropyltriethoxysilane and 0.091 parts by weight of γ-glycidyloxypropyltrimethoxysilane), accelerator (0.03 parts by weight of boron trifluoride ethylamine and 0.07 parts by weight of imidazole) and solvent (28 parts by weight of butanone, 75 parts by weight of acetone and 91 parts by weight of N,N-dimethylformamide);

[0153] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 73° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1250 r / min, and stirred for 3.75 h to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested to be 291 s at 180° C., thereby preparing a modified polyimide thermal insulation resin adhesive;

[0154] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0155] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1 MPa to 25 MPa for 0.5 h to 50 h. Specific process parameters are shown in Table 2, thereby obtaining a lightweight polyimide insulation board.

[0156] Example 19:

[0157] A method for preparing a lightweight polyimide thermal insulation board comprises the following steps:

[0158] a. Ingredients: prepare 100 parts by weight of polyimide resin, 34 parts by weight of silicone resin, nano-modifier (13 parts by weight of fumed silica and 19 parts by weight of hollow glass microspheres), modifying agent (0.044 parts by weight of γ-aminopropyltriethoxysilane, 0.024 parts by weight of 3-glycidyloxypropyltrimethoxysilane, 0.051 parts by weight of 3-aminopropyltriethoxysilane and 0.006 parts by weight of γ-glycidyloxypropyltrimethoxysilane), accelerator (0.019 parts by weight of imidazole, 0.073 parts by weight of boron trifluoride ethylamine and 0.004 parts by weight of diaminodiphenylmethane) and solvent (61 parts by weight of butanone, 43 parts by weight of acetone and 93 parts by weight of N,N-dimethylformamide);

[0159] b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 65° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin were stirred and mixed at a speed of 1400 r / min, and stirred for 4.5 hours to prepare a modified resin for standby use. After cooling to room temperature, the solvent and the accelerator were added and stirred. The resin molding time was tested at 180° C. for 150 seconds to obtain a modified polyimide thermal insulation resin adhesive;

[0160] c. Preparation of modified polyimide thermal insulation resin fiber fabric prepreg: The modified polyimide thermal insulation resin adhesive prepared in step b is coated on the aramid fiber fabric through a gluing machine, and then the aramid fiber fabric coated with the modified polyimide thermal insulation resin adhesive is placed in a drying tunnel. The drying tunnel is 50m long and divided into 4 sections, each 12.5m long. The baking temperature range is 100℃~185℃, wherein: the first section is 105℃~125℃, the second section is 135℃~165℃, the third section is 165℃~185℃, and the fourth section is 100℃~110℃. The speed of the gluing machine is 10m / min~25m / min to obtain the modified polyimide thermal insulation resin fiber fabric prepreg. The drying tunnel is pre-baked before baking. The soluble resin content of the fiber fabric prepreg is greater than or equal to 95%, and the volatile matter is less than or equal to 2%; the specific process parameters are shown in Table 1;

[0161] d. Preparation of lightweight polyimide insulation board: preheat the template at 145°C to 175°C, overlap the modified polyimide insulation resin fiber fabric prepreg and place it in the template. After closing the mold, hot press molding is performed at a temperature of 210°C to 220°C and a pressure of 1MPa to 25MPa. The hot press time is 0.5h to 50h. The specific process parameters are shown in Table 2. The lightweight polyimide insulation board is thus obtained.

[0162] The specific process parameters of Examples 1 to 19 and the technical performance test results of the lightweight polyimide insulation board are shown in Tables 1, 2, and 3 below respectively:

[0163] Table 1: Preparation process parameters and central control technical indicators of modified polyimide thermal insulation resin fiber fabric prepreg in Example

[0164]

[0165]

[0166] Table 2: Lightweight polyimide insulation board pressing process parameters

[0167]

[0168]

[0169] Table 3: Technical performance test data of lightweight polyimide insulation boards prepared in Examples 1-19

[0170]

[0171]

[0172] As shown in Table 1 and Table 2, the lightweight polyimide insulation board of the present invention has a bending strength of 380MPa to 450MPa at room temperature, a bending strength of 267MPa to 331MPa at 180°C, a tensile strength of 365MPa to 387MPa, and a notched impact strength of 60KJ / m 2 ~70KJ / m 2 , insulation resistance is greater than or equal to 10 8 MΩ, flame retardancy reaches UL94 V-0 level, thermal conductivity (25℃) is less than 0.2w / m·k and density is 1.55g / cm 3 ~1.75g / cm 3 , especially suitable for use in the field of lightweight thermal insulation.

[0173] Example 20:

[0174] A lightweight polyimide thermal insulation board is made by hot-pressing multiple layers of overlapping modified polyimide thermal insulation resin fiber fabric prepreg (the number of layers of the modified polyimide thermal insulation resin fiber fabric prepreg is not limited and can be any one of 1 to 500 layers as required);

[0175] The modified polyimide thermal insulation resin fiber fabric prepreg is obtained by coating a modified polyimide thermal insulation resin adhesive on an aramid fiber fabric and then baking the prepreg.

[0176] The modified polyimide thermal insulation resin adhesive is composed of 100 parts by weight of polyimide resin, 35 parts by weight of silicone resin, 35 parts by weight of nano-modifier, 0.13 parts by weight of modification treatment agent, 0.1 parts by weight of accelerator and 200 parts by weight of solvent;

[0177] The aramid fiber fabric is any one of aramid fiber plain cloth, aramid fiber twill cloth, aramid fiber gingham cloth, aramid fiber multiaxial cloth, and aramid fiber composite cloth.

[0178] Example 21:

[0179] A lightweight polyimide thermal insulation board is made by hot-pressing multiple layers of overlapping modified polyimide thermal insulation resin fiber fabric prepreg (the number of layers of the modified polyimide thermal insulation resin fiber fabric prepreg is not limited and can be any one of 1 to 500 layers as required);

[0180] The modified polyimide thermal insulation resin fiber fabric prepreg is obtained by coating a modified polyimide thermal insulation resin adhesive on an aramid fiber fabric and then baking the prepreg.

[0181] The modified polyimide thermal insulation resin adhesive is composed of 100 parts by weight of polyimide resin, 15 parts by weight of silicone resin, 5 parts by weight of nano-modifier, 0.04 parts by weight of modification treatment agent, 0.005 parts by weight of accelerator and 50 parts by weight of solvent;

[0182] The aramid fiber fabric is any one of aramid fiber plain cloth, aramid fiber twill cloth, aramid fiber gingham cloth, aramid fiber multiaxial cloth, and aramid fiber composite cloth.

[0183] Example 22:

[0184] A lightweight polyimide thermal insulation board is made by hot-pressing multiple layers of overlapping modified polyimide thermal insulation resin fiber fabric prepreg (the number of layers of the modified polyimide thermal insulation resin fiber fabric prepreg is not limited and can be any one of 1 to 500 layers as required);

[0185] The modified polyimide thermal insulation resin fiber fabric prepreg is obtained by coating a modified polyimide thermal insulation resin adhesive on an aramid fiber fabric and then baking the prepreg.

[0186] The modified polyimide thermal insulation resin adhesive is composed of 100 parts by weight of polyimide resin, 25 parts by weight of silicone resin, 20 parts by weight of nano-modifier, 0.085 parts by weight of modification treatment agent, 0.053 parts by weight of accelerator and 130 parts by weight of solvent;

[0187] The aramid fiber fabric is any one of aramid fiber plain cloth, aramid fiber twill cloth, aramid fiber gingham cloth, aramid fiber multiaxial cloth, and aramid fiber composite cloth.

[0188] The foregoing description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the concept described herein through the above teachings or techniques or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be protected by the appended claims.

[0189] In the above embodiments, the percentages used, unless otherwise specified, are all weight (mass) percentages or percentages known to those skilled in the art; the ratios used, unless otherwise specified, are all weight (mass) ratios; and the weight parts may be grams or kilograms.

[0190] In the above embodiments, the process parameters (temperature, pressure, time, vehicle speed, rotation speed, etc.) and the amounts of the components in each step are ranges, and any point can be applied.

[0191] The technical contents not specifically described in the present invention and the above embodiments are the same as the prior art, and the raw materials are all commercially available products.

[0192] The present invention is not limited to the above embodiments, and all of the contents of the present invention can be implemented and have the above good effects.

Claims

1. A lightweight polyimide insulation board, characterized by: The lightweight polyimide thermal insulation board is a lightweight polyimide thermal insulation board made by hot pressing multiple layers of overlapping modified polyimide thermal insulation resin fiber fabric prepreg; The modified polyimide thermal insulation resin fiber fabric prepreg is obtained by coating a modified polyimide thermal insulation resin adhesive on an aramid fiber fabric and then baking the prepreg. The modified polyimide thermal insulation resin adhesive is composed of 100 parts by weight of polyimide resin, 15-35 parts by weight of silicone resin, 5-35 parts by weight of nano-modifier, 0.04-0.13 parts by weight of modification treatment agent, 0.005-0.1 parts by weight of accelerator and 50-200 parts by weight of solvent. The aramid fiber fabric is at least one of aramid fiber plain cloth, aramid fiber twill cloth, aramid fiber woven cloth, aramid fiber multiaxial cloth, and aramid fiber composite cloth; In the modified polyimide thermal insulation resin adhesive: The nano-modifier is one or a mixture of fumed silica and hollow glass microspheres; The modifying agent is any one of 3-aminopropyltriethoxysilane and 3-glycidoxypropyltrimethoxysilane or a mixture of the two; The accelerator is any one of imidazole, diaminodiphenylmethane, and boron trifluoride ethylamine, or a mixture of two or more thereof; The solvent is a mixture of two or more of acetone, butanone, and N,N-dimethylformamide.

2. The lightweight polyimide thermal insulation board according to claim 1, characterized in that: The hot pressing molding is as follows: after preheating the template at 145°C to 175°C, the modified polyimide insulation resin fiber fabric prepreg is overlapped and placed in the template, and after closing the mold, hot pressing molding is performed under the conditions of temperature of 210°C to 220°C and pressure of 1MPa to 25MPa, and the hot pressing time is 0.5h to 50h.

3. The lightweight polyimide thermal insulation board according to claim 1 or 2, characterized in that: The baking method comprises the following steps: placing an aramid fiber fabric coated with a modified polyimide thermal insulation resin adhesive into a drying tunnel, wherein the drying tunnel is 50 meters long and divided into four sections, each section being 12.5 meters long; and the baking temperature ranges from 100° C. to 185° C., wherein the first section is 105° C. to 125° C., the second section is 135° C. to 165° C., the third section is 165° C. to 185° C., and the fourth section is 100° C. to 110° C. The speed of the gluing machine is 10 m / min to 25 m / min.

4. The lightweight polyimide thermal insulation board according to claim 1 or 2, characterized in that: The preparation method of the modified polyimide thermal insulation resin adhesive is as follows: at a temperature of 50°C to 85°C, the nano-modifier, the modification treatment agent, the polyimide resin and the silicone resin are stirred and mixed at a speed of 800r / min to 1500r / min, and the modified resin is prepared after stirring for 3h to 5h for standby use. After cooling to room temperature, a solvent and a accelerator are added and stirred to obtain the modified polyimide thermal insulation resin adhesive.

5. The lightweight polyimide thermal insulation board according to claim 1 or 2, characterized in that: In the modified polyimide thermal insulation resin fiber fabric prepreg, the weight percentage of the modified polyimide thermal insulation resin adhesive is 30% to 50%, and the weight percentage of the aramid fiber fabric is 50% to 70%.

6. The method for preparing a lightweight polyimide thermal insulation board according to claim 1, characterized in that The following steps are involved: a. Ingredients: Prepare the raw materials of each component according to the ratio of 100 parts by weight of polyimide resin, 15-35 parts by weight of silicone resin, 5-35 parts by weight of nano-modifier, 0.04-0.13 parts by weight of modification treatment agent, 0.005-0.1 parts by weight of accelerator and 50-200 parts by weight of solvent; The nano-modifier is one or a mixture of fumed silica and hollow glass microspheres; The modifying agent is any one of 3-aminopropyltriethoxysilane and 3-glycidoxypropyltrimethoxysilane or a mixture of the two; The accelerator is any one of imidazole, diaminodiphenylmethane, and boron trifluoride ethylamine, or a mixture of two or more thereof; The solvent is a mixture of two or more of acetone, butanone, and N,N-dimethylformamide; b. Preparation of modified polyimide thermal insulation resin adhesive: at a temperature of 50° C. to 85° C., the nano-modifier, the modifying agent, the polyimide resin and the silicone resin are stirred and mixed at a speed of 800 r / min to 1500 r / min, and stirred for 3 h to 5 h to prepare a modified resin for standby use. After cooling to room temperature, a solvent and a accelerator are added and stirred to obtain a modified polyimide thermal insulation resin adhesive; c. Preparing a modified polyimide thermal insulation resin fiber fabric prepreg: coating the modified polyimide thermal insulation resin adhesive prepared in step b on an aramid fiber fabric, and then baking to obtain a modified polyimide thermal insulation resin fiber fabric prepreg; The aramid fiber fabric is at least one of aramid fiber plain cloth, aramid fiber twill cloth, aramid fiber woven cloth, aramid fiber multiaxial cloth, and aramid fiber composite cloth; d. Preparation of lightweight polyimide insulation board: preheating the template at 145°C to 175°C, overlapping the modified polyimide insulation resin fiber fabric prepreg and placing it in the template, closing the mold and hot pressing it at a temperature of 210°C to 220°C and a pressure of 1MPa to 25MPa for 0.5h to 50h to obtain a lightweight polyimide insulation board.

7. The method for preparing the lightweight polyimide thermal insulation board according to claim 6, characterized in that: The baking method comprises placing an aramid fiber fabric coated with a modified polyimide thermal insulation resin adhesive into a drying tunnel. The drying tunnel is 50 meters long and divided into four sections, each section is 12.5 meters long. The baking temperature range is 100° C. to 185° C., wherein the first section is 105° C. to 125° C., the second section is 135° C. to 165° C., the third section is 165° C. to 185° C., and the fourth section is 100° C. to 110° C. The speed of the gluing machine is 10 m / min to 25 m / min.

8. The method for preparing the lightweight polyimide thermal insulation board according to claim 6 or 7, characterized in that: The performance parameters of the prepared lightweight polyimide insulation board are: bending strength at room temperature is 380MPa ～ 450MPa, flexural strength 267MPa at 180℃ ～ 331MPa, tensile strength 365MPa~387MPa, notched impact strength 60KJ / m 2 ～ 70KJ / m 2 , insulation resistance is greater than or equal to 10 8 MΩ, flame retardancy reaches UL94 V-0 level, thermal conductivity is less than 0.2w / m•k at 25℃, density is 1.55g / cm 3 ~1.75g / cm 3 .

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