CN117601512B

CN117601512B - Aerogel composite board and preparation method thereof

Info

Publication number: CN117601512B
Application number: CN202311625242.5A
Authority: CN
Inventors: 张秋华; 卫荣辉; 赵真真; 谭堂航; 邓文彬; 江小华; 陈淑娟; 王友华; 李阳辉
Original assignee: Guangdong Ellison Technology Co ltd
Current assignee: Guangdong Ellison Technology Co ltd
Filing date: 2023-11-30
Publication date: 2024-07-02
Anticipated expiration: 2043-11-30

Abstract

The application relates to an aerogel composite board and a preparation method thereof. The preparation method comprises the following steps: preparing sol by adopting an inorganic silicon source; preparing gel particles by adopting an organosilicon source; mixing the gel particles, the first reinforcing fibers and the inorganic particles with the sol to prepare a mixed glue solution; coating the mixed glue solution on the first base layer to form a glue solution layer; paving second reinforcing fibers on the glue layer to form a fiber layer; setting a second base layer on the fiber layer to obtain an intermediate plate; and (3) aging and drying the intermediate plate to prepare the aerogel composite plate. In the preparation method, the sol, the gel particles, the first reinforcing fibers, the inorganic particles, the second reinforcing fibers, the first base layer and the second base layer are cooperatively matched, so that the mechanical properties of the obtained aerogel composite board are improved.

Description

Aerogel composite board and preparation method thereof

Technical Field

The application relates to the field of aerogel preparation, in particular to an aerogel composite board and a preparation method thereof.

Background

The aerogel composite board is usually formed by compounding silica aerogel and reinforcing fibers, wherein the silica aerogel has the advantages of good heat insulation performance, small density and large specific surface area, the reinforcing fibers play a supporting role, the mechanical properties of the composite board can be guaranteed, and the aerogel composite board has been applied to the fields of construction, automobiles, aerospace and the like. At present, the preparation of the aerogel composite board still has the problems of high raw material cost and complex production process, and meanwhile, the mechanical properties of the aerogel composite board still need to be improved.

Disclosure of Invention

Based on the above, it is necessary to provide an aerogel composite board with good mechanical properties and a preparation method thereof.

In a first aspect of the present application, there is provided a method of preparing an aerogel composite panel, comprising the steps of:

preparing sol by adopting an inorganic silicon source;

Preparing gel particles by adopting an organosilicon source;

mixing the gel particles, the first reinforcing fibers and the inorganic particles with the sol to prepare a mixed glue solution;

Coating the mixed glue solution on the first base layer to form a glue solution layer;

Paving second reinforcing fibers on the glue layer to form a fiber layer;

setting a second base layer on the fiber layer to obtain an intermediate plate;

and (3) aging and drying the intermediate plate to prepare the aerogel composite plate.

According to the preparation method, the sol, the gel particles, the first reinforcing fibers and the inorganic particles are prepared into the mixed glue solution, wherein the sol prepared by adopting the inorganic silicon source has certain viscosity, can play a role in bonding and film forming, is beneficial to self bonding of each component in the mixed glue solution, and improves the bonding strength of each component in the obtained aerogel composite board; the gel particles prepared by adopting the organic silicon source have higher strength, can be used as seed crystals in aging treatment, shortens the gel aging time of a glue solution layer in the middle plate, and improves the gelation effect. Further, the first reinforcing fibers in the mixed glue solution can effectively strengthen the transverse tensile strength of the composite board, and the second reinforcing fibers compounded with the mixed glue solution can improve the longitudinal tensile strength of the composite board, so that the strength performance of the composite board can be improved in two directions. In addition, the first and second base layers may further improve the strength properties of the composite panel. In the preparation method, the sol, the gel particles, the first reinforcing fibers, the inorganic particles, the second reinforcing fibers, the first base layer and the second base layer are cooperatively matched, so that the mechanical properties of the obtained aerogel composite board are improved.

In addition, the inorganic silicon source and the organic silicon source are compounded and used in the preparation method, so that the water content in the mixed glue solution can be reduced, the drying process is simplified, and the drying time is shortened. And compared with the traditional technology for preparing aerogel by adopting an organosilicon source, the method can reduce the cost of raw materials.

In some embodiments, the volume ratio of the gel particles to the sol is (1-8): 1.

In some embodiments, the volume ratio of the first reinforcing fiber to the sol is (0.125-4): 1, a step of;

And/or the volume ratio of the inorganic particles to the sol is (0.1-0.5): 1.

In some of these embodiments, the first reinforcing fibers comprise staple fibers having a length of no more than 5 cm;

And/or, the second reinforcing fibers comprise alkali-free glass fiber filaments.

In some embodiments, the preparation method satisfies at least one of the following (1) - (5):

(1) The inorganic silicon source comprises at least one of sodium silicate, potassium silicate, sodium metasilicate and potassium metasilicate;

(2) The organic silicon source comprises at least one of methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, polymethyltrimethoxysilane, polymethyltriethoxysilane and hexamethyldisiloxane;

(3) The first reinforcing fiber is at least one selected from glass fiber, aluminum silicate fiber, quartz fiber, high silica fiber, aramid fiber and polyester fiber;

(4) The inorganic particles include at least one of calcium carbonate, aluminum silicate, aluminum oxide, and titanium oxide;

(5) The materials of the first base layer and the second base layer are each independently selected from at least one of glass fiber cloth, polyester cloth and non-woven fabric.

In some of these embodiments, the step of preparing a sol using an inorganic silicon source comprises:

the mass ratio is (1-8): (0.0015 to 0.5): and (3) mixing the inorganic silicon source, the acid catalyst and alcohol in the step (1-8) to prepare the sol.

In some of these embodiments, the step of preparing the gel particles using a silicone source comprises:

the molar ratio was set to 1: (1-5): mixing the organic silicon source, water and alcohol in the step (2-30), and sequentially adding an acid catalyst and an alkaline catalyst to prepare colloid;

and (3) carrying out aging treatment and forming treatment on the colloid to prepare the gel particles.

In some of these embodiments, prior to the step of disposing the second base layer on the fibrous layer, further comprising the steps of:

the steps of forming the gum layer and forming the fiber layer are alternately repeated until a specified thickness is reached.

In some embodiments, the preparation method satisfies at least one of the following (1) - (3):

(1) The thickness of the gum layer and the fiber layer are respectively and independently selected from 0.5 mm-7 mm;

(2) The specified thickness is 1 mm-30 mm;

(3) Before the step of forming the gum layer, the method further comprises the step of flattening the fiber layer formed in the previous time.

In a second aspect of the present application, there is provided an aerogel composite panel made according to the method of the first aspect.

Drawings

FIG. 1 is a schematic illustration of a step of preparing an intermediate panel in an aerogel composite panel, according to one embodiment.

Reference numerals illustrate:

1-first basic unit, 2-gum liquid layer, 3-fibrous layer, 4-second basic unit, 5-first unreeling roller, 6-second unreeling roller, 7-third unreeling roller, 8-compression roller, 9-extruder.

Detailed Description

The present application will be described more fully hereinafter in order to facilitate an understanding of the present application. This application may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the description of the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

The weights of the relevant components mentioned in the description of the embodiments of the present application may refer not only to the specific contents of the components, but also to the proportional relationship between the weights of the components, so long as the contents of the relevant components in the description of the embodiments of the present application are scaled up or down within the scope of the disclosure of the embodiments of the present application. Specifically, the weight described in the specification of the embodiment of the application can be mass units known in the chemical industry field such as mu g, mg, g, kg.

In the preparation of silica aerogel materials, an organosilicon source or an inorganic silicon source is generally used as a raw material. The cost of the organosilicon source is high, and particularly in the preparation of aerogel composite panels, a large amount of organosilicon source is consumed in order to obtain panels with high strength and density. However, when the inorganic silicon source is used to prepare the aerogel, the inorganic silicon source needs to be prepared into an aqueous solution, which causes the obtained wet gel to contain more water, so that the water in the wet gel needs to be replaced by an organic solvent before the wet gel is dried, thereby reducing the production efficiency and increasing the manufacturing cost. In addition, the density and strength of conventional aerogel composite panels remain to be improved. Based on the above, the technical staff of the application improves the traditional preparation method and provides a brand new preparation method of the aerogel composite board.

The embodiment of the application provides a preparation method of an aerogel composite board, which comprises the following steps S100-S700.

S100, preparing sol by adopting an inorganic silicon source.

In some of these embodiments, the inorganic silicon source comprises at least one of sodium silicate, potassium silicate, sodium metasilicate, and potassium metasilicate.

In a specific embodiment, the inorganic silicon source comprises at least one of an aqueous sodium silicate solution, an aqueous potassium silicate solution, an aqueous sodium metasilicate solution, and an aqueous potassium metasilicate solution. In this example, the inorganic silicon source is provided in the form of an aqueous solution, and the specific content of the inorganic silicon-containing compound in the aqueous solution can be determined by one skilled in the art according to actual needs. Further, the aqueous sodium silicate solution is also called water glass, and the aqueous potassium silicate solution is also called potash water glass.

In some of these embodiments, step S100 includes:

the mass ratio is (1-8): (0.0015 to 0.5): mixing the inorganic silicon source, the acid catalyst and alcohol in the (1-8) to prepare sol.

Understandably, the inorganic silicon source undergoes a hydrolysis reaction under the action of an acidic catalyst to form a silica sol. In addition, as the hydrolysis reaction consumes water in the inorganic silicon source, the obtained sol has lower water content and higher viscosity, and can play roles of bonding and film forming in the subsequent preparation process, thereby being beneficial to self-bonding and forming of the aerogel composite board. Further, the mass ratio of the inorganic silicon source, the acid catalyst and the alcohol is controlled to be (1-8): (0.0015 to 0.5): (1-8) can fully hydrolyze the inorganic silicon source and control the water content in the sol to be lower.

Alternatively, the mass ratio of the inorganic silicon source, the acidic catalyst, and the alcohol may be 1:0.0015: 1. 1:0.01: 1. 1:0.05: 1. 4:0.0015: 4. 4:0.01: 4. 4:0.05: 4. 8:0.0015: 8. 8:0.01: 8. 8:0.05: 8. 1:0.5:8 or 4:1:2, the mass ratio of the inorganic silicon source, the acid catalyst and the alcohol can be (1-8): (0.0015 to 0.5): and (1) to (8) and other suitable choices are made.

In a specific embodiment, the acidic catalyst of step S100 includes at least one of hydrofluoric acid, hydrochloric acid, nitric acid, oxalic acid, acetic acid, and sulfuric acid.

In a specific embodiment, the alcohol of step S100 comprises at least one of methanol and ethanol.

In a specific embodiment, the inorganic silicon source, the acidic catalyst and the alcohol are mixed at 10-40 ℃ for 5-40 min to prepare the sol.

S200, preparing gel particles by adopting an organosilicon source.

Understandably, the strength properties of aerogels produced from silicone sources are better than those of inorganic sources, and the wet gel water content formed from silicone sources is lower, typically without solvent replacement for direct drying. However, the organosilicon sources are expensive, resulting in higher raw material costs for the aerogel. In the embodiment, the organic silicon source is adopted to prepare the gel particles, so that the strength performance of the obtained composite board can be improved, and the gel particles can be used as seed crystals to improve the effect of aging treatment in the subsequent aging treatment process.

In some of these embodiments, the silicone source comprises at least one of methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, polymethyltrimethoxysilane, polymethyltriethoxysilane, and hexamethyldisiloxane.

In some embodiments, the step S200 includes the following steps S210-S220.

S210, the molar ratio is 1: (1-5): mixing the organic silicon source, water and alcohol in the step (2-30), and sequentially adding an acid catalyst and an alkaline catalyst to prepare colloid;

S220, aging and molding the colloid to prepare gel particles.

Understandably, the organosilicon source hydrolyzes under the action of an acidic catalyst to form a silica sol, which is subsequently gelled under the action of a basic catalyst to form a primarily gelled colloid. Then the gel is fully gelled by aging treatment, and gel particles can be prepared after the molding treatment.

In some of these embodiments, the alcohol of step S210 comprises at least one of methanol and ethanol.

In some of these embodiments, the acidic catalyst of step S210 comprises at least one of hydrofluoric acid, hydrochloric acid, nitric acid, oxalic acid, acetic acid, and sulfuric acid.

In some of these embodiments, the alkaline catalyst of step S210 comprises at least one of ammonia, sodium hydroxide, and sodium bicarbonate.

In some of these embodiments, step S210 includes the steps of:

the molar ratio was set to 1: (1-5): mixing the organic silicon source, water and alcohol in the step (2-30), adding an acid catalyst, and regulating the pH to 5-6.5;

and then adding an alkaline catalyst, and regulating the pH to 6.5-7 to prepare the colloid.

In some embodiments, the aging treatment time in step S220 is 4-48 hours, and the aging treatment temperature is 20-60 ℃.

In some of these embodiments, the molding process of step S220 includes the steps of:

placing the aged colloid into a forming die to prepare a flaky gel colloid;

crushing the flaky gel colloid to prepare gel particles.

In a specific embodiment, the gel particles have a particle size of no more than 2 cm.

In some of these embodiments, the gel particles are prepared from an aerogel recovered in an aerogel production process.

In a specific embodiment, the preparation feedstock for the recovered aerogel includes a silicone source.

S300, mixing gel particles, first reinforcing fibers, inorganic particles and sol to prepare mixed glue solution.

In some embodiments, the volume ratio of gel particles to sol is (1-8): 1.

According to the embodiment, the relationship between the raw material cost and the density and strength of the obtained aerogel composite board can be balanced by regulating the volume ratio of gel particles to sol, so that the raw material cost of the aerogel composite board is reduced, a certain density is maintained, and the mechanical property of the composite board is improved. In addition, the gel particles and the sol are cooperated, so that the mixed glue solution has lower water content while ensuring the gel aging effect of the mixed glue solution, and the organic solvent in the gel particles can dilute the water content of the mixed sol after gelation in the drying process, so that the mixed sol is easy to dry and separate, the drying treatment step can be simplified, and the drying effect and the drying quality can be improved.

Further, compared to the conventional technique of preparing aerogel using pure inorganic silicon source, the amount of inorganic silicon source used can be relatively reduced due to the addition of gel particles in this embodiment. Thus, the wet gel formed after the aging treatment has a lower water content in the present embodiment, and the drying process can be simplified and the drying time can be shortened. Furthermore, compared with the traditional technology for preparing aerogel by adopting a pure organic silicon source, the sol prepared by the inorganic silicon source is added in the embodiment, so that the usage amount of the organic silicon source can be relatively reduced, and the density and the strength of the obtained aerogel composite board can be ensured, and meanwhile, the raw material cost can be reduced.

Alternatively, the volume ratio of gel particles to sol may be 1: 1. 2: 1.3: 1. 4: 1. 5: 1. 6: 1. 7:1 or 8:1, the volume ratio of gel particles to sol can be (1-8): other suitable choices are made within the scope of 1.

In some embodiments, the volume ratio of the first reinforcing fiber to the sol is (0.125-4): 1. according to the embodiment, the transverse strength of the aerogel composite board can be effectively improved by adjusting and controlling the volume ratio of the first reinforcing fibers to the sol.

Alternatively, the volume ratio of the first reinforcing fibers to the sol may be 0.125: 1. 0.5: 1. 1:1. 1.5: 1. 2: 1. 2.5: 1. 3: 1. 3.5:1 or 4:1, the volume ratio of the first reinforcing fiber to the sol may be (0.125-4): other suitable choices are made within the scope of 1. One skilled in the art can determine the specific volume ratio of the first reinforcing fiber to the sol according to the actual strength requirement, that is, the aerogel composite board with different strengths can be prepared according to the actual requirement in the embodiment so as to meet various application requirements.

In some of these embodiments, the first reinforcing fibers comprise staple fibers having a length of no more than 5 cm. When the length of the first reinforcing fiber meets the above conditions, the transverse strength of the aerogel composite panel can be more effectively improved.

In some of these embodiments, the first reinforcing fibers have a diameter of no more than 7 μm. Optionally, the first reinforcing fibers are fiber particles.

In some of these embodiments, the first reinforcing fibers are selected from at least one of glass fibers, aluminum silicate fibers, quartz fibers, high silica fibers, aramid fibers, and polyester fibers.

In some embodiments, the volume ratio of inorganic particles to sol is (0.1-0.5): 1. according to the embodiment, the density and strength performance of the aerogel composite board can be effectively improved by adjusting and controlling the volume ratio of the inorganic particles to the sol.

Alternatively, the volume ratio of inorganic particles to sol may be 0.1: 1. 0.2: 1. 0.3: 1. 0.4: 1. or 0.5:1, the volume ratio of the inorganic particles to the sol can be (0.1-0.5): other suitable choices are made within the scope of 1.

In some of these embodiments, the inorganic particles comprise at least one of calcium carbonate, aluminum silicate, aluminum oxide, and titanium oxide.

In some embodiments, the mixing temperature in step S300 is 20-30 ℃ and the mixing time is 10-60 min.

S400, coating the mixed glue solution on the first base layer to form a glue solution layer.

In some of these embodiments, the first base layer is selected from at least one of fiberglass cloth, polyester cloth, and non-woven cloth.

In some embodiments, the first base layer has a thickness of 0.2 mm to 1 mm.

In some of these embodiments, the mixed liquor is coated onto the first substrate using an extruder.

S500, paving second reinforcing fibers on the glue layer to form a fiber layer.

In some of these embodiments, the second reinforcing fibers comprise alkali-free glass fiber filaments.

The second reinforcing fibers are understandably laid along the glue layer direction and cover the glue layer. Further, the length of the second reinforcing fiber is not limited, and in the actual production process, the coiled second reinforcing fiber is paved on the glue solution layer, and when the glue solution layer is covered by the second reinforcing fiber, the second reinforcing fiber is cut off.

In some of these embodiments, after forming the fibrous layer, a step of planarizing the fibrous layer is included. In a specific embodiment, the planarization process is performed using a pressing roller.

And S600, setting a second base layer on the fiber layer to obtain the intermediate plate.

Understandably, a formed sheet, i.e., an intermediate sheet, can be obtained through steps S400 to S600. Since the mixed glue solution in the intermediate plate is not completely gelled, it is necessary to sufficiently gel the mixed glue solution by aging treatment to obtain wet gel, and then remove moisture in the wet gel by drying treatment to obtain the aerogel composite plate.

In some of these embodiments, the material of the second base layer is each independently selected from at least one of fiberglass cloth, polyester cloth, and non-woven cloth.

In some embodiments, the second base layer has a thickness of 0.2 mm to 1 mm.

In some of these embodiments, prior to the step of disposing the second base layer on the fibrous layer, the method further comprises the steps of:

Understandably, in this embodiment, the glue layer and the fiber layer are combined in a layer-by-layer assembly manner, specifically, the glue layer and the fiber layer are sequentially laminated on the first base layer, and after reaching a specified thickness, the second base layer is further arranged, so that the intermediate plate is obtained.

Further, the step of forming the fiber layer may be performed after the step of forming the dope layer is completed, that is, after the mixed dope is completely coated on the designated area of the first base layer, the step of forming the fiber layer is performed. The step of forming the fiber layer may be performed after the mixed glue solution is coated for a certain distance, that is, after the mixed glue solution is partially coated on the designated area of the first base layer, the second reinforcing fiber is laid, thereby improving the production efficiency.

For example, reference may be made to fig. 1, which illustrates the steps of preparing an intermediate sheet in one embodiment. Specifically, the first unreeling roller 5 unreels the first base layer 1, and performs a flattening process by a press roller 8 adjacent to the first unreeling roller 5, and then the mixed glue is extruded by an extruder 9 adjacent to the press roller 8, and coated on the first base layer 1, thereby forming the first glue layer 2. The second unreeling roller 6 then unreels the second reinforcing fibers and the first fiber layer 3 is formed by flattening the second reinforcing fibers by the press roller 8 adjacent to the second unreeling roller 6. The steps of forming the glue layer 2 and forming the fibre layer 3 are repeated until the specified thickness is reached. Next, the third unreeling roller 7 unreels the second base layer 4, and a flattening process is performed by the press roller 8 adjacent to the third unreeling roller 7, whereby an intermediate board can be obtained.

In some of these embodiments, prior to the step of forming the gum layer, a step of planarizing the previously formed fibrous layer is included. In a specific embodiment, the planarization process is performed using a pressing roller.

In some embodiments, the thickness of the gum layer is 0.5 mm-7 mm. Optionally, the thickness of the glue layer may be 0.5mm, 4 mm, 5mm, 6 mm or 7 mm, and the thickness of the glue layer may be selected from the range of 0.5mm to 7 mm.

In some of these embodiments, the fibrous layer has a thickness of 0.5mm to 7 mm. Alternatively, the thickness of the fiber layer may be 0.5mm, 4 mm, 5mm, 6 mm, or 7 mm, and the thickness of the fiber layer may be selected from the range of 0.5mm to 7 mm.

In some of these embodiments, the specified thickness is 1mm to 30 mm. Alternatively, the specified thickness may be 1mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, or 30 mm, and the specified thickness may be selected from a range of 1mm to 30 mm.

In some of these embodiments, a preheating treatment is also included after the step of obtaining the intermediate sheet. Specifically, the preheating treatment is performed after the second base layer is provided.

Understandably, the components in the mixed glue solution can be fully dissolved by the preheating treatment, and the fluidity of the mixed glue solution can be improved, so that the thickness uniformity of the glue solution layer is improved. Optionally, the temperature of the preheating treatment is 20-60 ℃ and the time is 1-10 min.

And S700, aging and drying the intermediate plate to prepare the aerogel composite plate.

In some embodiments, the temperature of the aging treatment of step S700 is 20 ℃ to 60 ℃.

In some embodiments, the aging treatment in step S700 is performed for 4h to 48 h.

In some embodiments, the aging process may further comprise placing the intermediate sheet in a pre-shaped mold for injection molding and then aging.

It is understood that intermediate panels of different shapes can be obtained by injection molding, whereby aerogel composite panels of different shapes can be obtained to meet different application requirements. Illustratively, the pre-shaping mold may be square, semi-circular, or shell-and-tube.

In some of these embodiments, a modification treatment is also included after the aging treatment and before the drying treatment. In a specific embodiment, the modification treatment comprises a hydrophobic treatment.

In some of these embodiments, the drying process of step S700 includes supercritical drying.

In some of these embodiments, the supercritical medium employed for supercritical drying comprises at least one of supercritical ethanol and supercritical carbon dioxide.

In some embodiments, the supercritical drying temperature is 60-80 ℃, the pressure is 11-13 MPa, and the time is 2-5 h.

Another embodiment of the present application provides an aerogel composite panel made according to the above-described method of making.

The aerogel composite board has higher strength and can be applied to but not limited to the field of building heat preservation and heat insulation and the field of furnace body heat insulation. In addition, the aerogel composite board has low raw material cost and wide application prospect.

The following are specific examples.

Example 1

(1) Preparation of sols

The mass ratio is 4:1:2, mixing and stirring the sodium silicate, the hydrofluoric acid and the ethanol at 20 ℃ for 0.5 h to obtain sol.

(2) Preparation of gel particles

The molar ratio was set to 1:3:8, water and ethanol are uniformly mixed at the temperature of 10 ℃, then hydrofluoric acid is added, the pH value of the system is regulated to be 6, ammonia water is added after stirring for 0.25 h, the pH value of the system is regulated to be 6.5, and stirring is continued for 0.25 h, so that the colloid is obtained.

Placing the colloid in an injection molding sol box of a molding die, aging at 30 ℃ for 12 h to obtain a flaky gel colloid, and then crushing the flaky gel colloid to prepare gel particles with the particle size not exceeding 2 cm.

(3) Preparation of Mixed glue solution

Mixing the gel particles, glass fibers and inorganic particles prepared in the step (2) with the sol prepared in the step (1), and stirring at 25 ℃ for 0.5 h to obtain a mixed glue solution.

Wherein, the volume ratio of gel particles to sol is 2:1, the volume ratio of the first reinforcing fiber to the sol is 1:1, the volume ratio of the inorganic particles to the sol is 0.5:1, and the mass ratio of the inorganic particles is 1:1 and aluminum silicate.

(4) Intermediate plate for preparing aerogel composite plate

As shown in fig. 1, the first unreeling roller 5 pays out and transfers the first base layer 1 onto a transfer platform (not shown in the figure), the first base layer 1 is flattened by a press roller 8 adjacent to the first unreeling roller 5, and then the mixed glue is extruded by an extruder 9 adjacent to the press roller 8 and spread on the first base layer 1, thereby forming a first glue layer 2 having a thickness of about 0.5 mm. The second unreeling roller 6 then unreels the second reinforcing fibers and the first fiber layer 3 is formed by flattening the second reinforcing fibers by the press roller 8 adjacent to the second unreeling roller 6. The steps of forming the gum layer 2 and forming the fiber layer 3 were repeated 2 times until 10 mm was reached. Next, the third unreeling roller 7 unreels the second base layer 4, and a flattening process is performed by the press roller 8 adjacent to the third unreeling roller 7. The composite material laid with the second base layer 4 was then transferred to a preheating zone for preheating treatment at 50c for 5min c, thereby obtaining an intermediate board.

Wherein, the material of the first base layer 1 is glass fiber cloth, the second reinforcing fiber is alkali-free glass fiber long fiber, the thickness of the fiber layer is about 0.5 mm, and the material of the second base layer 4 is glass fiber cloth.

The resulting intermediate sheet was placed in a pre-set mold for injection molding and then aged at 30 ℃ for 8h to gel the mixed gum solution in the gum layer. And then placing the intermediate plate subjected to the ageing treatment in a supercritical drying kettle, and performing solvent replacement (namely liquid exchange), modification treatment and drying treatment.

Specifically, ethanol is firstly injected into a supercritical drying kettle, the temperature is raised to 50 ℃, the pressure is raised to 5MPa ℃, the heat and pressure are maintained for 0.5: 0.5 h, the exchange liquid is exchanged, and then the exchange liquid is discharged. Then injecting the mixed modifying liquid and the supercritical medium, heating to 50 ℃, raising the temperature to 5MPa ℃, preserving heat and pressure to 0.5 h, and discharging the residual mixed modifying liquid after treatment. And then carrying out supercritical drying, heating to 70 ℃, boosting to 12 MPa, and drying to 3 h to obtain the aerogel composite board.

Example 2

The preparation method of example 2 is substantially the same as that of example 1, except that: in the step (3), the volume ratio of gel particles to sol is 1:1.

Example 3

The preparation method of example 3 is substantially the same as that of example 1, except that: in the step (3), the volume ratio of gel particles to sol is 8:1.

Example 4

The preparation method of example 4 is substantially the same as that of example 1, except that: in the step (3), the volume ratio of the first reinforcing fiber to the sol is 0.125:1.

Example 5

The preparation method of example 5 is substantially the same as that of example 1, except that: in the step (3), the volume ratio of the first reinforcing fiber to the sol is 4:1.

Example 6

The preparation method of example 6 was substantially the same as that of example 1, except that: in the step (3), the volume ratio of the inorganic particles to the sol is 0.1:1.

Comparative example 1

The preparation method of comparative example 1 was substantially the same as that of example 1, except that: in step (3), no gel particles are added.

Comparative example 2

The preparation method of comparative example 2 was substantially the same as that of example 1, except that: in step (3), the first reinforcing fibers are not added.

The volume ratios of the gel particles, the first reinforcing fibers, and the inorganic particles to the sol in the preparation methods of examples 1 to 6 and comparative examples 1 to 2 are as follows in table 1:

TABLE 1

The composite aerogel sheets prepared in examples 1 to 6 and comparative examples 1 to 2 were subjected to density and strength performance tests, and the test results are shown in table 2 below.

The test standards of each performance test project are as follows:

density: tested using the method of GB/T34336-2017.

Compressive strength: tested using the method of GB/T13480.

Bending failure load: tested using the method of GB/T34336-2017.

TABLE 2

As can be seen from the above Table 2, the composite aerogel plates of examples 1 to 6 have higher density and compressive strength, and the bending damage load is greater than 60N, which indicates that the preparation method of the application can obtain the composite aerogel plate with better mechanical properties.

Comparative example 1 contained no gel particles, and the mixed dope consisted mainly of an inorganic silicon source and a first fiber, and the obtained composite aerogel plate was inferior in strength although the density could meet the requirement. This is because the inorganic silicon source of comparative example 1 forms a higher sol ratio than that of example 1 at the same thickness, the water content in the mixed glue solution is higher, the drying effect is poor when drying, and the number of nano Kong Tanta of aerogel in the obtained composite board is large, so that although the density can meet the requirement, the rebound resilience is lost under a certain pressure, and the compressive strength is low. And the surface of the composite board is easy to crack under the action of pressure.

Comparative example 2 did not add the first reinforcing fiber for the gel particles and the sol directly combined, the combination between the two was weak, after forming the composite sheet, the density was lower, the mechanical properties were poor, compressive strength was low, and cracking was easy under the effect of pressure.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. The preparation method of the aerogel composite board is characterized by comprising the following steps of:

preparing sol by adopting an inorganic silicon source;

Preparing gel particles by adopting an organosilicon source;

Mixing the gel particles, the first reinforcing fibers and the inorganic particles with the sol to prepare a mixed glue solution; the volume ratio of the first reinforcing fiber to the sol is (1-4): 1, a step of; the volume ratio of the gel particles to the sol is (1-8): 1, a step of; the volume ratio of the inorganic particles to the sol is (0.1-0.5): 1, a step of;

Paving second reinforcing fibers on the glue layer to form a fiber layer;

setting a second base layer on the fiber layer to obtain an intermediate plate;

Aging and drying the intermediate plate to prepare the aerogel composite plate;

wherein, the step of preparing sol by using inorganic silicon source comprises:

the mass ratio is (1-8): (0.0015 to 0.5): mixing the inorganic silicon source, the acidic catalyst and the alcohol of (1-8) to prepare the sol;

the step of preparing gel particles using a silicone source comprises:

the molar ratio was set to 1: (1-5): mixing the organosilicon source, water and alcohol of (2-30), and sequentially adding an acid catalyst and an alkaline catalyst to prepare colloid;

Aging and molding the colloid to prepare the gel particles;

the inorganic silicon source comprises at least one of sodium silicate, potassium silicate, sodium metasilicate and potassium metasilicate; the organic silicon source comprises at least one of methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane and hexamethyldisiloxane; the first reinforcing fiber is at least one selected from glass fiber, aluminum silicate fiber, quartz fiber, high silica fiber, aramid fiber and polyester fiber; the inorganic particles include at least one of calcium carbonate, aluminum silicate, aluminum oxide, and titanium oxide; the materials of the first base layer and the second base layer are each independently selected from at least one of glass fiber cloth, polyester cloth and non-woven fabric.

2. The method of preparing an aerogel composite panel as claimed in claim 1, wherein the volume ratio of the first reinforcing fiber to the sol is (1-3): 1.

3. The method of making an aerogel composite panel of claim 1, wherein the first reinforcing fibers comprise staple fibers having a length of no more than 5 cm.

4. The method of making an aerogel composite panel of claim 1, wherein the second reinforcing fibers comprise alkali-free glass fiber long fibers.

5. The method of making an aerogel composite panel as claimed in any one of claims 1 to 4, further comprising, prior to the step of disposing a second base layer on the fibrous layer, the steps of:

6. The method of producing an aerogel composite panel as claimed in claim 5, wherein the method of producing satisfies at least one of the following (1) to (3):

(2) The specified thickness is 1 mm-30 mm;

7. An aerogel composite panel produced according to the production method of any one of claims 1 to 6.