Lightweight high-efficiency heat-insulating / medium-preventing sealing composite material and preparation method thereof

Abstract

The invention belongs to the technical field of heat insulation materials, and particularly relates to a light efficient heat insulation / medium prevention sealing composite material and a preparation method thereof.The composite material comprises a heat insulation core material, a protective layer is arranged on the outer surface of the heat insulation core material, the heat insulation core material takes resin slurry as a base body, the resin slurry is injected into a fiber needled felt, and the fiber needled felt is formed; the resin slurry is composed of temperature-resistant resin, an organic solvent and a heat-insulating filler in a mass ratio of (36-60): (65-96): 1, and the protective layer comprises a temperature-resistant isolating film, a temperature-resistant adhesive film and a temperature-resistant prepreg which are laid on the outer surface of the heat-insulating core material and are heated and cured to form a sealing structure. The preparation method is simple in preparation process, controllable in process parameters, high in feasibility, good in repeatability, excellent in material sealing performance and excellent in environment resistance, can effectively maintain light weight and efficient heat insulation performance for a long time in complex industrial environment application, and greatly prolongs the service life of the composite material.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermal insulation materials, and particularly relates to a light-weight high-efficiency thermal insulation / medium-proof sealing composite material and a preparation method thereof. BACKGROUND

[0002] With the development of science and technology, the limitations of traditional thermal insulation materials have gradually become one of the important factors restricting the development of equipment. Early thermal insulation materials, such as glass wool / rock wool, calcium silicate board, and vermiculite, have good thermal insulation performance, but poor sealing performance, and the porous structure is easy to permeate water vapor or air, resulting in a decrease in thermal insulation performance. In addition, the durability is insufficient, the strength is low, the moisture absorption is easy, the aging is easy, and the mechanical stress is easy to destroy. There are also health and environmental risks. In order to overcome the defects of traditional materials, thermal insulation materials have gradually evolved towards the direction of composite, multifunctional, lightweight, and environmentally friendly.

[0003] In the thermal insulation composite material, the fiber-reinforced resin-based composite material is widely used, which has the advantages of light weight, high strength, high temperature resistance, corrosion resistance, and strong designability. Through the design of the ideal structure model of the matrix and the reinforcing body, a light-weight thermal insulation composite material with excellent performance can be prepared. However, due to the structural characteristics of the fiber-reinforced resin-based composite material, the resin matrix has poor environmental resistance, and in actual application, it is easy to be affected by high and low temperature environments and industrial media, resulting in an increase in the weight of the composite material, a decrease in performance, and even failure. Therefore, it is urgent to develop a new type of light-weight high-efficiency thermal insulation / medium-proof sealing composite material.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provides a light-weight high-efficiency thermal insulation / medium-proof sealing composite material and a preparation method thereof. The present application innovatively researches and prepares a thermal insulation core material, and designs a protective layer sealing coating on the surface of the thermal insulation core material, thereby solving the technical problem of poor environmental resistance of the resin matrix.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: On the one hand, the present application provides a light-weight high-efficiency thermal insulation / medium-proof sealing composite material, which comprises a thermal insulation core material, the outer surface of the thermal insulation core material is provided with a protective layer, the thermal insulation core material is injected into a fiber needle felt with a resin slurry as a matrix, the resin slurry is composed of temperature-resistant resin, organic solvent and thermal insulation filler with a mass ratio of 36-60:65-96:1, and the protective layer comprises a sealing structure formed by laying and pasting a temperature-resistant isolation film, a temperature-resistant adhesive film and a temperature-resistant prepreg on the outer surface of the thermal insulation core material and then heating and curing.

[0007] Further, the temperature-resistant resin is one of a silicone resin, a phenolic resin, and a silicone-modified phenolic resin; specifically, each of the above resins is selected from a thermosetting resin. The organic solvent is one of benzene, alcohol, and ester solvent. The heat-insulating filler is potassium hexatitanate or hollow glass microsphere.

[0008] The bulk density of the fiber needle-punched felt is 0.12-0.20 g / cm3. 3 .

[0009] Further, the temperature-resistant film is one of an epoxy film and a cyanate ester film. Further, the temperature-resistant prepreg is composed of a resin and a fiber cloth, wherein the resin is a thermosetting resin selected from one of an epoxy resin, a bismaleimide resin, a cyanate ester resin, and a polyimide resin; and the fiber cloth is one of a quartz fiber cloth, a glass fiber cloth, and a carbon fiber cloth. Specifically, the temperature-resistant prepreg is obtained by uniformly brushing the temperature-resistant resin on the fiber cloth by using a hand lay-up method and then performing heat treatment.

[0010] Further, the areal density of the fiber cloth is 140-300 g / m2. 2 .

[0011] In another aspect, the present application provides a preparation method of the light-weight and high-efficiency heat-insulating / medium-proof sealing composite material, for preparing the light-weight and high-efficiency heat-insulating / medium-proof sealing composite material as described above, comprising the following steps: Step 1, pretreatment: pretreating the fiber needle-punched felt; Step 2, preparing resin slurry: mixing the temperature-resistant resin, the organic solvent, and the heat-insulating filler according to a mass ratio of 36-60:65-96:1, uniformly dispersing, and then sieving to obtain resin slurry for injection molding; Step 3, preparing heat-insulating core material: loading the pretreated fiber needle-punched felt into an injection molding tool that is wiped clean with anhydrous ethanol, vacuumizing, then injecting the resin slurry obtained in Step 2 into the injection molding tool through the glue injection port of the injection molding tool by using gradient glue injection pressure, so that the resin slurry is fully infiltrated and dispersed in the fiber needle-punched felt, and then sequentially performing gelation, volatilization, and curing treatment on the fiber needle-punched felt to obtain the heat-insulating core material; Step 4, preparing protective layer: setting the protective layer on the upper and lower surfaces and the side edges of the heat-insulating core material obtained in Step 3, and then performing curing treatment to complete the preparation of the light-weight and high-efficiency heat-insulating / medium-proof sealing composite material.

[0012] Further, the specific process of Step 1 is as follows: placing the fiber needle-punched felt into an oven at 80-120 ℃ and heating for 80-120 min to obtain the pretreated fiber needle-punched felt.

[0013] Further, in step 2, the raw materials are loaded into a container in a mass ratio and placed on a dispersion homogenizer, the dispersion rotation speed is set to 3000-5000 r / min, and the dispersion time is 60-120 min, to obtain a resin slurry; The temperature-resistant resin is one of thermosetting silicone resin, phenolic resin and silicon-modified phenolic resin; the organic solvent is one of benzene, alcohol and ester solvent; and the heat-insulating filler is potassium hexatitanate or hollow glass microsphere.

[0014] Further, in step 3, the specific process of vacuumizing is as follows: vacuumizing to -0.08 to -0.10 MPa and keeping for 30-60 min; The gradient glue injection pressure is in the range of 0.1-1 MPa, and the pressure keeping time is 40-120 min.

[0015] Further, in step 3, the specific process of gelling is as follows: keeping the injection molding tooling sealed and placing it into an oven, gelling at 80-150℃ for 6-12 h; The specific process of volatilizing is as follows: removing the upper forming mold after gelling, heat treating at 80-150℃ for 60-120 min, re-installing the upper forming mold after heat treatment, removing the lower forming mold, heat treating at 80-150℃ for 60-120 min, and re-installing the lower forming mold after heat treatment; The specific process of curing is as follows: placing the injection molding tooling with all the molds into an oven, curing at 80-100℃ for 60-120 min, then curing at 140-160℃ for 60-120 min, and curing at 180-200℃ for 120-180 min, and removing the injection molding tooling with all the molds after curing, to obtain the heat-insulating core material.

[0016] Further, in step 4, the specific process of preparing the protective layer is as follows: (1) wiping the upper forming mold and the lower forming mold of the laying tooling with anhydrous ethanol, naturally air-drying, and uniformly applying release agent 2-5 times at an interval of 15-20 min each time; (2) sequentially laying, from bottom to top, temperature-resistant isolation film, temperature-resistant prepreg, temperature-resistant adhesive film, heat-insulating core material, temperature-resistant adhesive film, temperature-resistant prepreg and temperature-resistant isolation film on the surface of the lower forming mold of the laying tooling, wherein the size of the temperature-resistant isolation film is larger than that of the temperature-resistant prepreg, the periphery of the temperature-resistant isolation film is edge-sealed, the temperature-resistant isolation film on the top is covered with a glue-absorbing air-permeable felt, and the above structure is sealed in a vacuum bag by a sealing rubber strip, and the vacuum bag is pre-vacuumized to remove air between the layers; (3) removing the vacuum bag and the glue-absorbing air-permeable felt, installing the upper forming mold, fixing, and placing the laying tooling into an oven to cure the surface protective layer under the set process parameters.

[0017] Specifically, the specific process of the curing treatment is: 100-140 DEG C heat treatment for 20-60 min, followed by 130-180 DEG C heat treatment for 60-130 min, and then 180-220 DEG C heat treatment for 60-180 min.

[0018] Compared with the prior art, the present application has the following beneficial effects: 1) The light-weight high-efficiency heat-insulating / medium-proof sealing composite material proposed by the present application has excellent sealing performance due to the sealing and covering design and integrated forming preparation of the heat-insulating core material / surface protective layer in the overall structure, has excellent environmental resistance, can effectively maintain the light weight and high-efficiency heat-insulating performance for a long time in complex industrial environment applications, and greatly improves the service life of the composite material.

[0019] 2) The heat-insulating core material of the light-weight high-efficiency heat-insulating / medium-proof sealing composite material comprises fiber needle punching felt, temperature-resistant resin and heat-insulating filler, and solid-solid heat transfer, gas-solid heat transfer and interstitial gas phase convection are formed among the three, thereby improving the heat-insulating efficiency of the composite material. In addition, the surface protective layer comprises temperature-resistant resin and temperature-resistant adhesive film, the overall temperature resistance is improved, and the purpose of sealing the overall structure is achieved.

[0020] 3) In the preparation process of the resin matrix, the heat-insulating filler with extremely low thermal conductivity is introduced, which can effectively regulate the overall heat-insulating performance of the heat-insulating core material under the premise of maintaining the low density of the heat-insulating composite material; in addition, when the resin flows and gathers downward due to its own gravity factor when entering the inside of the fiber needle punching felt, the gradient glue injection process is adopted for the heat-insulating core material in the present application to ensure the effective wettability of the resin slurry and the fiber needle punching felt, so that the resin of the injection-molded blank part is uniformly dispersed.

[0021] 4) The preparation method provided by the present application has simple preparation process, controllable process parameters, strong feasibility and good repeatability. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings incorporated into the specification and forming a part thereof, together with the specification, serve to explain the principles of the present application.

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The flowchart of the preparation method of the present application. DETAILED DESCRIPTION

[0025] The example embodiments will be described in detail below with reference to the accompanying drawings, the implementations described in the following example embodiments are not representative of all implementations consistent with the present application. Rather, they are merely examples consistent with some aspects of the present application as detailed in the appended claims.

[0026] Embodiment 1 In one aspect, the present embodiment provides a light-weight and high-efficiency thermal / medium-proof sealing composite material, comprising a thermal insulation core material, an outer surface of the thermal insulation core material being provided with a protective layer, the thermal insulation core material being injected into a quartz fiber needle-punched felt with a resin slurry as a matrix, the resin slurry being composed of a temperature-resistant resin, an organic solvent and a thermal insulation filler in a mass ratio of 36:80:1, the protective layer comprising a sealing structure formed by laying a temperature-resistant isolation film, a cyanate adhesive film and a cyanate quartz fiber prepreg on the outer surface of the thermal insulation core material.

[0027] Further, the temperature-resistant resin is a thermosetting silicone resin, the organic solvent is xylene, and the thermal insulation filler is a low-density hollow glass microsphere.

[0028] Further, the fiber needle-punched felt is a quartz fiber needle-punched felt, and the bulk density of the quartz fiber needle-punched felt is 0.16-0.17 g / cm 3 , and the thickness is 8 mm.

[0029] In another aspect, referring to Figure 1 , the present embodiment provides a preparation method of a light-weight and high-efficiency thermal / medium-proof sealing composite material, which is used for preparing the light-weight and high-efficiency thermal / medium-proof sealing composite material as described above, comprising the following steps: Step 1, pretreating the quartz fiber needle-punched felt to remove water vapor; placing the fiber needle-punched felt into a 100℃ oven and heating for 120 min to obtain the pretreated fiber needle-punched felt; Step 2, mixing the temperature-resistant resin, the organic solvent and the thermal insulation filler in a mass ratio of 36:80:1, and uniformly dispersing and sieving to obtain a resin slurry for injection molding; using a thermosetting silicone resin as the temperature-resistant resin, xylene as the organic solvent, and a low-density hollow microsphere as the thermal insulation filler, mixing in a mass ratio of 36:80:1, adjusting the dispersion rotation speed to 3000 r / min, and stirring for 60 min to obtain the resin slurry.

[0030] Step 3, the pre-processed quartz fiber needle felt is loaded into an injection molding tool cleaned with anhydrous ethanol, vacuumed to-0.08 MPa and maintained for 40 min, then the resin slurry obtained in step 2 is injected into the injection molding tool by gradient injection process, specifically by gradient pressure injection: 0.1 MPa pressure is applied by the RTM injection molding machine, pressure maintaining for 40 min, pressure relief; 0.2 MPa pressure is applied, pressure maintaining for 40 min, pressure relief; 0.2 MPa pressure is repeatedly applied, pressure maintaining for 40 min, without pressure relief; after the injection is completed, the resin slurry is fully infiltrated and dispersed in the quartz fiber needle felt; then the injection molding tool is placed at a temperature of 130°C for 12h for gelation, after the gelation is completed, the injection molding tool is cooled to room temperature, and then solvent evaporation is performed, the solvent evaporation procedure is: the upper forming mold of the injection molding tool is removed, the remaining tool is placed at a temperature of 140°C for 120 min for heat preservation, after the heat preservation is completed, the injection molding tool is cooled to room temperature, the upper mold is installed, the injection molding tool is turned upside down, the lower mold of the injection molding tool is removed, and the remaining tool is placed at a temperature of 140°C for 120 min for heat preservation, after the heat preservation is completed, the injection molding tool is cooled to room temperature, the mold is reassembled, and curing begins; the curing procedure is: the injection molding tool after the mold is assembled is moved into an oven for curing at 100°C for 60 min, then at 140°C for 60 min, and then at 200°C for 180 min, and when the injection molding tool is cooled to room temperature, the thermal insulation core material is taken out from the injection molding tool.

[0031] Step 4, surface protection layer preparation (1) The upper forming mold and the lower forming mold of the laying tool are wiped with anhydrous ethanol and naturally air-dried; the release agent is evenly applied 3 times with an interval of 15 min each time; (2) On the surface of the lower forming mold of the laying tool, the temperature-resistant isolation film, the cyanate ester quartz fiber prepreg, the cyanate ester adhesive film, the thermal insulation core material, the cyanate ester adhesive film, the cyanate ester quartz fiber prepreg, and the temperature-resistant isolation film are sequentially laid from bottom to top, wherein the size of the temperature-resistant isolation film is larger than that of the temperature-resistant prepreg, the cyanate ester adhesive film, and the thermal insulation core material, the edges of the temperature-resistant isolation film are sealed, then the glue-absorbing air-permeable felt is covered on the top temperature-resistant isolation film and sealed in the vacuum bag by a sealing rubber strip, and the vacuum bag is pre-vacuumed; (3) Vacuum to-0.09 MPa, vacuum for 30 min, after completion, remove the glue-absorbing air-permeable felt, install the upper forming mold, fix, and place the laying tool in an oven for surface protection layer curing, i.e. curing treatment, under the set process parameters.

[0032] Further, in step 4, the specific process of the curing treatment is: 120°C heat treatment for 30 min, then 150°C heat treatment for 120 min, and then 180°C heat treatment for 60 min.

[0033] The operation sequence of steps 1 and 2 is not limited.

[0034] Embodiment 2 In one aspect, the embodiment provides a light-weight and high-efficiency thermal / medium-proof sealing composite material, which comprises a thermal insulation core material, an outer surface of the thermal insulation core material is provided with a protective layer, the thermal insulation core material is injected into a quartz fiber needle-punched felt with a resin slurry as a matrix, the resin slurry is composed of a temperature-resistant resin, an organic solvent and a thermal insulation filler with a mass ratio of 44:65:1, and the protective layer comprises a sealing structure formed by laying a temperature-resistant isolation film, an epoxy adhesive film and an epoxy resin quartz fiber prepreg on the outer surface of the thermal insulation core material.

[0035] Further, the temperature-resistant resin is a silicon-modified phenolic resin, the organic solvent is an analytical grade anhydrous ethanol, and the thermal insulation filler is a low-density hollow glass microsphere.

[0036] Further, the fiber needle-punched felt is a quartz fiber needle-punched felt, and the bulk density of the quartz fiber needle-punched felt is 0.18-0.20 g / cm 3 , and the thickness is 5 mm.

[0037] In another aspect, the embodiment provides a preparation method of a light-weight and high-efficiency thermal / medium-proof sealing composite material, which is used for preparing the light-weight and high-efficiency thermal / medium-proof sealing composite material as described above, and comprises the following steps: Step 1, pretreating a quartz fiber needle-punched felt; The fiber needle-punched felt is placed into a 100℃ oven for heating for 120 min to obtain the pretreated fiber needle-punched felt.

[0038] Step 2, mixing a silicon-modified phenolic resin, ethanol and a low-density hollow microsphere according to a mass ratio of 44:65:1 to obtain the resin slurry; the dispersion rotation speed is 4000 r / min, and the dispersion time is 60 min. Step 3, the pretreated quartz fiber needle felt is loaded into an injection tool cleaned with anhydrous ethanol, vacuumed to -0.10 MPa and kept for 40 min, then the resin slurry obtained in step 2 is injected into the injection tool by gradient injection process, specifically, gradient pressure injection is adopted: 0.2 MPa pressure is applied by an RTM injection machine, pressure keeping for 100 min, pressure release; 0.4 MPa pressure is applied, pressure keeping for 60 min, pressure release; 0.6 MPa pressure is applied, pressure keeping for 40 min, no pressure release; after the injection is completed, the resin slurry is allowed to fully infiltrate and disperse in the quartz fiber needle felt; then the injection tool is placed at a temperature of 90°C for 12 h of gelation, after the gelation is completed, the injection tool is allowed to cool to room temperature, and then solvent evaporation is performed, the solvent evaporation procedure is as follows: the upper forming die of the injection tool is removed, the remaining tool is placed at a temperature of 100°C for 120 min of heat preservation, after the heat preservation is completed, the injection tool is allowed to cool to room temperature, the upper die is installed, the injection tool is turned upside down, the lower die of the injection tool is removed, the remaining tool is placed at a temperature of 100°C for 120 min of heat preservation, after the heat preservation is completed, the injection tool is reassembled, and curing is started; the cured injection tool is moved into an oven for curing at 100°C for 60 min, then at 140°C for 60 min, and then at 180°C for 180 min, and when the injection tool cools to room temperature, the thermal insulation core material is taken out from the injection tool.

[0039] Step 4, surface protection layer preparation (1) The upper forming die and the lower forming die of the laying tool are wiped with anhydrous ethanol and naturally air-dried; release agent is evenly applied twice with an interval of 20 min each time; (2) On the surface of the lower forming die of the laying tool, the temperature-resistant isolation film, the epoxy resin quartz fiber prepreg, the epoxy adhesive film, the thermal insulation core material, the epoxy adhesive film, the epoxy resin quartz fiber prepreg and the temperature-resistant isolation film are sequentially laid from bottom to top, wherein the size of the temperature-resistant isolation film is larger than that of the epoxy resin quartz fiber prepreg, the epoxy adhesive film and the thermal insulation core material, the edges of the temperature-resistant isolation film are sealed, then the glue-absorbing air-permeable felt is covered on the top temperature-resistant isolation film and sealed in a vacuum bag by a sealing rubber strip, and the vacuum bag is pre-vacuumized; (3) Vacuum to -0.10 MPa, vacuum for 30 min, after completion, remove the glue-absorbing air-permeable felt, install the upper forming die, fix, and place the laying tool in an oven for surface protection layer curing under the set process parameters.

[0040] Further, in step 4, the specific process of curing treatment is: 100°C heat treatment for 30 min, then 130°C heat treatment for 60 min, and then 180°C heat treatment for 60 min.

[0041] Example 3 In one aspect, the embodiment provides a light-weight and high-efficiency thermal / medium-proof sealing composite material, comprising a thermal core material, an outer surface of the thermal core material being provided with a protective layer, the thermal core material being injected into a quartz fiber needle felt with a resin slurry as a matrix, the resin slurry being composed of a temperature-resistant resin, an organic solvent and a thermal insulation filler with a mass ratio of 53:65:1, the protective layer comprising a sealing structure formed by laying a temperature-resistant isolation film, an epoxy adhesive film and an epoxy resin carbon fiber prepreg on the outer surface of the thermal core material.

[0042] Further, the temperature-resistant resin is a silicone resin, the organic solvent is ethyl acetate, and the thermal insulation filler is low-thermal-conductivity potassium hexatitanate particles.

[0043] Further, the fiber needle felt is a glass fiber needle felt, and the bulk density of the glass fiber needle felt is 0.13-0.14 g / cm 3 , and the thickness is 9 mm.

[0044] In another aspect, the embodiment provides a preparation method of a light-weight and high-efficiency thermal / medium-proof sealing composite material, which is used for preparing the light-weight and high-efficiency thermal / medium-proof sealing composite material as described above, and comprises the following steps: Step 1, pretreating a glass fiber needle felt; The fiber needle felt is placed in a 100℃ oven and heated for 120 min to obtain the pretreated fiber needle felt.

[0045] Step 2, mixing a silicone resin, dimethylbenzene and potassium hexatitanate according to a mass ratio of 53:65:1, placing an iron bucket containing the mixed resin slurry on a dispersion homogenizer, adjusting the rotation speed to 4000 r / min, and stirring at room temperature for 60 min to obtain the resin slurry; Step 3, the pretreated glass fiber needle felt is loaded into an injection molding tool cleaned with anhydrous ethanol, vacuumed to -0.09 MPa and kept for 30 min, and then the resin slurry obtained in step 2 is injected into the injection molding tool by gradient injection process, specifically by gradient pressure injection: 0.3 MPa pressure is applied by an RTM injection machine, pressure keeping for 95 min, and then pressure release; 0.6 MPa pressure is applied, pressure keeping for 80 min, and then pressure release; 0.9 MPa pressure is applied once, pressure keeping for 50 min, and then no pressure release; after the injection is completed, the resin slurry is allowed to fully infiltrate and disperse in the glass fiber needle felt; then the injection tool is placed at a temperature of 140°C for 10 h of gelation, after the gelation is completed, the injection tool is allowed to cool to room temperature, and then solvent evaporation is performed, the solvent evaporation procedure being: the upper forming die of the injection tool is removed, the remaining tool is placed at a temperature of 150°C for 120 min of heat preservation, after the heat preservation is completed, the injection tool is allowed to cool to room temperature, the lower forming die of the injection tool is removed, the remaining tool is placed at a temperature of 150°C for 120 min of heat preservation, after the heat preservation is completed, the injection tool is allowed to cool to room temperature, and then the upper forming die is installed, the injection tool is turned upside down, and the insulation core material in the injection tool is taken out.

[0046] Step 4, surface protection layer preparation (1) The upper forming die and the lower forming die of the laying tool are wiped with anhydrous ethanol and naturally air-dried; the release agent is uniformly applied 3 times with an interval of 15 min each time; (2) On the surface of the lower forming die of the laying tool, the temperature-resistant isolation film, the epoxy carbon fiber prepreg, the epoxy film, the insulation core material, the epoxy film, the epoxy carbon fiber prepreg, and the temperature-resistant isolation film are sequentially laid from bottom to top, wherein the size of the temperature-resistant isolation film is larger than that of the epoxy carbon fiber prepreg, the epoxy film, and the insulation core material, the edges of the temperature-resistant isolation film are sealed, the glue-absorbing air-permeable felt is then covered on the top temperature-resistant isolation film, and the vacuum bag is sealed by a sealing rubber strip, and the vacuum bag is pre-vacuumed; (3) Vacuuming to -0.09 MPa is performed for 30 min, after completion, the glue-absorbing air-permeable felt is removed, the upper forming die is installed and fixed, and the laying tool is placed in an oven for surface protection layer curing under the set process parameters.

[0047] Further, in step 4, the specific process of the curing treatment is: 100°C heat treatment for 30 min, then 130°C heat treatment for 60 min, and then 180°C heat treatment for 120 min.

[0048] Example 4 The embodiment provides a preparation method of a light-weight high-efficiency thermal / medium-proof sealing composite material, comprising the following steps: Step 1, pretreatment of the glass fiber needle-punched felt; The fiber needle-punched felt is placed into an 80°C oven and heated for 100 min to obtain the pretreated fiber needle-punched felt. The glass fiber needle-punched felt body density is 0.14-0.15 g / cm 3 , and the thickness is 8 mm.

[0049] Step 2, the temperature-resistant resin, the organic solvent and the thermal insulation filler are mixed in a mass ratio of 40:75:1, uniformly dispersed and sieved to obtain resin slurry for injection molding. The phenolic resin is used as the temperature-resistant resin, the analytical grade anhydrous ethanol is used as the organic solvent, the low-density hollow microspheres are used as the thermal insulation filler, and the mixing ratio is 40:75:1, the dispersion rotation speed is adjusted to 3500 r / min, and the stirring time is 120 min to obtain the resin slurry.

[0050] Step 3, the pretreated quartz fiber needle-punched felt is placed into the injection molding tool cleaned with anhydrous ethanol, vacuumized to-0.08 MPa and kept for 60 min, then the resin slurry obtained in step 2 is injected into the injection molding tool by using gradient injection process, specifically, gradient pressure injection is adopted: 0.1 MPa pressure is applied by using an RTM injection molding machine, pressure keeping for 60 min and pressure unloading; 0.2 MPa pressure is applied, pressure keeping for 50 min and pressure unloading; 0.3 MPa pressure is applied, pressure keeping for 30 min and pressure unloading; 0.1 MPa pressure is applied, pressure keeping for 60 min and pressure unloading; 0.2 MPa pressure is applied, pressure keeping for 50 min and pressure unloading; 0.3 MPa pressure is applied, pressure keeping for 30 min and pressure unloading; injection is finished, the resin slurry is fully infiltrated and dispersed in the quartz fiber needle-punched felt; then the injection molding tool is placed at a temperature of 80°C for gelation for 12 h, after gelation, the injection molding tool is taken out after the temperature of the injection molding tool decreases to room temperature, solvent evaporation is carried out, the solvent evaporation procedure is as follows: the upper forming mold of the injection molding tool is removed, the remaining tool is placed at a temperature of 100°C for heat preservation for 60 min, after heat preservation, the temperature of the injection molding tool decreases to room temperature, the lower mold of the injection molding tool is removed, the remaining tool is placed at a temperature of 100°C for heat preservation for 60 min, after heat preservation, the temperature of the injection molding tool decreases to room temperature, the injection molding tool is reassembled, and solidification is started; the solidification procedure is as follows: the reassembled injection molding tool is moved into an oven and solidified at 80°C for 60 min, then solidified at 150°C for 60 min and then solidified at 180°C for 120 min, the thermal insulation core material is taken out from the injection molding tool when the temperature of the injection molding tool decreases to room temperature.

[0051] Step 4, surface protection layer preparation (1) Wipe the upper forming mold and the lower forming mold of the laying tool with anhydrous ethanol and dry naturally; evenly apply release agent 5 times, with an interval of 20 min each time; (2) Place the temperature-resistant release film, the bismaleimide quartz fiber prepreg, the cyanate ester adhesive film, the thermal insulation core material, the cyanate ester adhesive film, the bismaleimide quartz fiber prepreg, and the temperature-resistant release film on the surface of the lower forming mold of the laying tool from bottom to top, wherein the size of the temperature-resistant release film is larger than that of the bismaleimide quartz fiber prepreg, the cyanate ester adhesive film, and the thermal insulation core material, and the edges of the temperature-resistant release film are sealed, then the glue-absorbing air-permeable felt is covered on the top temperature-resistant release film, and the vacuum bag is sealed by a sealing rubber strip, and the vacuum bag is pre-vacuumized; (3) Vacuumize to -0.09 MPa, and vacuumize for 30 min, then remove the glue-absorbing air-permeable felt, install the upper forming mold, fix, and place the laying tool in an oven for surface protective layer curing, i.e., curing treatment, under the set process parameters.

[0052] Further, in step 4, the specific process of the curing treatment is: 140℃ heat treatment for 50 min, then 170℃ heat treatment for 110 min, and then 200℃ heat treatment for 60 min.

[0053] Example 5 The embodiment provides a preparation method of a lightweight and efficient thermal / medium-resistant sealing composite material, comprising the following steps: Step 1, pretreat the quartz fiber needle-punched felt; Place the fiber needle-punched felt in a 120℃ oven and heat for 80 min to obtain the pretreated fiber needle-punched felt; The quartz fiber needle-punched felt has a bulk density of 0.16-0.17 g / cm 3 and a thickness of 8 mm.

[0054] Step 2, mix the temperature-resistant resin, the organic solvent, and the thermal insulation filler according to a mass ratio of 60:96:1, uniformly disperse, and sieve to obtain resin slurry for injection molding; Mix the silicone resin as the temperature-resistant resin, the dimethylbenzene as the organic solvent, and the low-density hollow microspheres as the thermal insulation filler according to a mass ratio of 60:96:1, adjust the dispersion rotation speed to 5000 r / min, stir for 80 min, and obtain the resin slurry.

[0055] Step 3, the pretreated quartz fiber needle felt is loaded into an injection molding tool cleaned with anhydrous ethanol, vacuumed to -0.08 MPa and kept for 50 min, then the resin slurry obtained in step 2 is injected into the injection molding tool by gradient injection process, specifically, gradient pressure injection is adopted: 0.2 MPa pressure is applied by the RTM injection molding machine, pressure keeping for 100 min, pressure release; 0.4 MPa pressure is applied, pressure keeping for 80 min, pressure release; 0.6 MPa pressure is applied, pressure keeping for 60 min, no pressure release; after the injection is completed, the resin slurry is fully infiltrated and dispersed in the quartz fiber needle felt; then the injection molding tool is placed at a temperature of 150°C for 6h for gelation, after the gelation is completed, the solvent is volatilized after the temperature of the injection molding tool decreases to room temperature, the solvent volatilization procedure is as follows: the upper forming mold of the injection molding tool is removed, the remaining tool is placed at a temperature of 160°C for 100 min for heat preservation, after the heat preservation is completed, the temperature of the injection molding tool decreases to room temperature, the upper mold is installed, the injection molding tool is turned upside down, the lower mold of the injection molding tool is removed, the remaining tool is placed at a temperature of 160°C for 100 min for heat preservation, after the heat preservation is completed, the temperature of the injection molding tool decreases to room temperature, the mold is closed again, and the curing starts; the curing procedure is as follows: the injection molding tool after the mold is closed is moved into an oven for curing at 90°C for 80 min, continues to be cured at 150°C for 90 min, and continues to be cured at 190°C for 150 min, when the tool decreases to room temperature, the thermal insulation core material is taken out from the injection molding tool.

[0056] Step 4, surface protection layer preparation (1) The upper forming mold and the lower forming mold of the laying tool are wiped with anhydrous ethanol and naturally air dried; the release agent is evenly applied 4 times with an interval of 16 min each time; (2) On the surface of the lower forming mold of the laying tool, the temperature-resistant isolation film, the polyimide resin quartz fiber prepreg, the cyanate ester adhesive film, the thermal insulation core material, the cyanate ester adhesive film, the polyimide resin quartz fiber prepreg and the temperature-resistant isolation film are sequentially laid from bottom to top, wherein the size of the temperature-resistant isolation film is larger than that of the polyimide resin quartz fiber prepreg, the cyanate ester adhesive film and the thermal insulation core material, the edges of the temperature-resistant isolation film are sealed, then the glue absorption air permeable felt is covered on the top temperature-resistant isolation film, and the above structure is sealed in a vacuum bag by a sealing rubber strip, and the vacuum bag is pre-vacuumized; (3) Vacuum to -0.09 MPa, vacuum for 30 min, after completion, remove the glue absorption air permeable felt, install the upper forming mold, fix, and place the laying tool in an oven for surface protection layer curing, i.e. curing treatment, under the set process parameters.

[0057] Further, in step 4, the specific process of the curing treatment is as follows: 130°C heat treatment for 20 min, then 180°C heat treatment for 130 min, and then 220°C heat treatment for 180 min.

[0058] To verify the performance of the light-weight and high-efficiency heat insulation / medium-proof sealing composite material prepared in Examples 1-5, the composite material samples prepared in Examples 1-5 were respectively subjected to performance tests, and the specific results are shown in Table 1 below, wherein the heat insulation performance test is based on the GJB10304 standard, the thickness test is based on the GB / T 6672 standard, and the areal density test is based on the GB / T 9775 standard.

[0059] Table 1: Performance test results of materials in various examples From the above verification results, it can be seen that the composite material prepared in the present application not only meets the required heat insulation performance, but also has good medium resistance performance.

[0060] The above description is merely specific embodiments of the present application, which enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application.

[0061] It should be understood that the present application is not limited to the above-described and that various modifications and changes can be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A lightweight, high-efficiency thermal / medium-resistant sealing composite material, characterized in that, The application relates to a light-weight high-efficiency heat-insulating / medium-proof sealing composite material, which comprises a heat-insulating core material, the outer surface of the heat-insulating core material is provided with a protective layer, the heat-insulating core material is injected into a fiber needle-punched felt with resin slurry as a matrix, the resin slurry is composed of temperature-resistant resin, organic solvent and heat-insulating filler in a mass ratio of 36-60:65-96:1, and the protective layer comprises sealing structures formed by laying and pasting temperature-resistant isolation films, temperature-resistant adhesive films and temperature-resistant prepregs on the outer surfaces of the heat-insulating core material and then heating and curing.

2. The lightweight, high-performance thermal / medium-resistant sealing composite material according to claim 1, wherein, The temperature-resistant resin is one of silicon resin, phenolic resin and silicon-modified phenolic resin; The organic solvent is one of benzene, alcohol and ester solvents; The heat-insulating filler is potassium hexatitanate or hollow glass microspheres.

3. The lightweight, high-performance thermal / medium-resistant sealing composite material according to claim 1, wherein, The temperature-resistant adhesive film is an epoxy adhesive film or a cyanate ester adhesive film; The temperature-resistant prepreg is composed of resin and fiber cloth, and the resin is one of epoxy resin, bismaleimide resin, cyanate ester resin and polyimide resin.

4. A method of making a lightweight, high-efficiency thermal / medium-resistant sealing composite material, characterized by, The application further discloses a preparation method of the light-weight high-efficiency heat-insulating / medium-proof sealing composite material. Step 1: pretreatment, the fiber needle-punched felt is pretreated; Step 2: preparation of resin slurry, the temperature-resistant resin, the organic solvent and the heat-insulating filler are mixed in a mass ratio of 36-60:65-96:1, and are uniformly dispersed and sieved to obtain resin slurry for injection molding; Step 3: preparation of the heat-insulating core material, the pretreated fiber needle-punched felt is loaded into injection molding equipment which is wiped clean with anhydrous ethanol, vacuum is drawn, then the resin slurry obtained in step 2 is injected into the injection molding equipment through a glue injection port of the injection molding equipment by adopting gradient glue injection pressure, the resin slurry is fully infiltrated and dispersed in the fiber needle-punched felt, then the fiber needle-punched felt is sequentially subjected to gelation, volatilization and curing treatment to obtain the heat-insulating core material; Step 4: preparation of the protective layer, the protective layer is arranged on the upper and lower surfaces and the side edges of the heat-insulating core material obtained in step 3, and then curing treatment is carried out, so that the preparation of the light-weight high-efficiency heat-insulating / medium-proof sealing composite material is completed.

5. The preparation method according to claim 4, characterized in that, The specific process of step 1 is that the fiber needle-punched felt is placed into an oven at 80-120 DEG C and heated for 80-120 min to obtain the pretreated fiber needle-punched felt.

6. The preparation method according to claim 4, characterized in that, In step 2, the raw materials are loaded into a container in a mass ratio and placed on a dispersing homogenizer, the dispersing rotation speed is set to 3000-5000 r / min, and the dispersing time is 60-120 min, so as to obtain the resin slurry.

7. The preparation method according to claim 4, characterized in that, In step 3, the specific process of vacuumizing is that vacuumizing is carried out to-0.08 to-0.10 MPa and maintained for 30-60 min; The gradient glue injection pressure is in the range of 0.1-1 MPa, and the pressure maintaining time is 40-120 min.

8. The preparation method according to claim 4, characterized in that, In step 3, the specific process of gelation is that the injection molding equipment is kept sealed and placed into an oven, gelation is carried out at 80-150 DEG C for 6-12 h; The specific process of volatilization is that the upper forming mold is removed after gelation, heat treatment is carried out at 80-150 DEG C for 60-120 min, and the upper forming mold is reinstalled after the heat treatment is completed; The lower forming mold is removed, heat treatment is carried out at 80-150 DEG C for 60-120 min, and the lower forming mold is reinstalled after the heat treatment is completed; The curing process is as follows: the reassembled injection tooling is placed in an oven, cured at 80-100°C for 60-120 min, then cured at 140-160°C for 60-120 min, and then cured at 180-200°C for 120-180 min. After curing, all the molds of the injection tooling are removed, and the thermal insulation core material is obtained.

9. The preparation method according to claim 4, characterized in that, In step 4, the specific process for preparing the protective layer is as follows: (1) Wipe the upper and lower forming molds of the laying tooling with anhydrous ethanol, and naturally air dry. Apply release agent 2-5 times, with an interval of 15-20 min each time. (2) Place the temperature-resistant isolation film, temperature-resistant prepreg, temperature-resistant adhesive film, thermal insulation core material, temperature-resistant adhesive film, temperature-resistant prepreg, and temperature-resistant isolation film on the surface of the lower forming mold of the laying tooling from bottom to top. The size of the temperature-resistant isolation film is larger than that of the temperature-resistant prepreg. Seal the edges of the temperature-resistant isolation film, cover the top temperature-resistant isolation film with a glue-absorbing air-permeable felt, then seal the structure in a vacuum bag with a sealing rubber strip, and pre-evacuate the vacuum bag to remove air between the layers. (3) Remove the vacuum bag and the glue-absorbing air-permeable felt, install the upper forming mold, fix it, and place the laying tooling in an oven for surface protective layer curing under the set process parameters.

10. The method of claim 4, wherein, In step 4, the specific process for curing is as follows: heat treatment at 100-140°C for 20-60 min, then heat treatment at 130-180°C for 60-130 min, and then heat treatment at 180-220°C for 60-180 min.

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