Aluminum silicate fiberboard and preparation method thereof

Abstract

The invention relates to the technical field of thermal insulation materials, in particular to an aluminum silicate fiberboard and a preparation method thereof.According to the preparation method, inorganic silicon source aerogel and inorganic fibers are combined, use of organic matter is avoided, the product has higher fire resistance and incombustibility, and meanwhile good thermal insulation and sound insulation performance is guaranteed; and the stability and environmental protection property of the product are improved by using the inorganic material.

Description

Technical Field

[0001] The invention relates to the technical field of thermal insulation materials, and in particular to an aluminum silicate fiberboard and a preparation method thereof. Background Art

[0002] In order to smoothly develop the "dual carbon" goal, promoting green, energy-saving and low-carbon building materials is one of the inevitable ways. One of the more important measures for low carbonization is to develop thermal insulation materials. Thermal insulation materials have the properties of high temperature resistance, low thermal conductivity, low density and high porosity. Their loose, lightweight and porous characteristics can play a role in heat preservation and are widely used in aerospace, national defense, chemical industry and construction. For every ton of mineral wool insulation products used in buildings, about one ton of oil is saved per year. Therefore, vigorously developing thermal insulation materials is of great significance to my country's economic construction and stable development. Today's global building materials are developing in the direction of energy saving, high efficiency, thin layer, fire prevention, heat insulation, sound insulation and waterproof integration.

[0003] Most of the aluminum silicate fiberboards in the prior art are formed by curing after mixing inorganic fibers with organic solutions or organic adhesives. The aluminum silicate fiberboards prepared in this way have a relatively flat surface, which meets the basic requirements for appearance flatness in some conventional application scenarios. However, due to the introduction of organic components, the product has fatal defects in fire resistance. When the board body encounters a high temperature environment or even an open flame, the organic matter therein will rapidly undergo a combustion reaction. Under the action of the flame, the board surface will quickly turn black in a very short time. This is because the carbonization process of organic matter proceeds rapidly at high temperatures, accompanied by the generation of a large amount of black smoke. This combustion phenomenon will not only cause serious damage to the structural integrity of the fiberboard, causing it to lose its original thermal insulation function, but also the thick smoke released will pollute the environment and may hinder the evacuation of personnel and fire rescue work in a fire scene, greatly increasing the safety risk when a fire occurs.

[0004] With the increasingly stringent fire safety standards and the increasing emphasis on fire safety, this traditional aluminum silicate fiberboard containing organic matter has been unable to meet the needs of actual use. Especially in industries such as petrochemicals, electric power, and high-temperature kilns, the ambient temperature around the equipment is often high, which places extremely high demands on the fire resistance of the material. Therefore, it is urgent to develop a production process for aluminum silicate fiberboard with excellent fire resistance. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a method for preparing an aluminum silicate fiberboard, which solves the technical problems that the aluminum silicate fiberboard itself is not fire-resistant, is easy to burn at high temperature, and the board surface quickly turns black and emits black smoke when burned by flames.

[0007] (II) Technical solution

[0008] In a first aspect, the present invention provides a method for preparing an aluminum silicate fiberboard, comprising the following steps:

[0009] Step 1: using a dispersant to stir and disperse the aluminum silicate fibers, remove the slag, and dilute to obtain a slurry, using a wet-laid web forming technology to obtain an aluminum silicate fiber wet felt, and removing moisture to obtain an aluminum silicate fiber felt;

[0010] Step 2: dispersing lithium silicate and silica sol in an acetic acid aqueous solution to prepare an inorganic aerogel silicon source solution;

[0011] Step 3: impregnating the aluminum silicate fiber wet felt with the inorganic aerogel silicon source solution, and then performing aerogel gelation and microwave aging treatment to obtain a primary aluminum silicate fiber board;

[0012] Step 4: the primary aluminum silicate fiberboard is impregnated with a mixed solution of a hydrophobic modifier and a reinforcing agent, and then subjected to a combined microwave and far infrared treatment;

[0013] Step 5: Adjust thickness and cut to size to obtain aluminum silicate fiberboard.

[0014] Optionally, in step 1, the speed of the mixer is 500 to 2000 rpm;

[0015] The dispersant is selected from one or more of polyacrylic acid amide anion, polyacrylic acid amide cation, sodium hexametaphosphate, sodium tripolyphosphate, sodium polyacrylate, and hydroxypropyl methylcellulose HPMC.

[0016] The dispersant can break up the inorganic aluminum silicate fibers to a certain extent, because the fiber dispersant can reduce the interaction forces between the fibers, such as van der Waals forces, etc. The inorganic aluminum silicate fibers may agglomerate during production and storage, and the dispersant can penetrate into the fiber agglomerates to weaken the bonding forces between the fibers, thereby achieving the purpose of breaking up the fibers.

[0017] It can also keep the fibers evenly dispersed in the diluted solution, prevent the fibers from flocculating or settling due to dilution, and ensure a uniform and stable slurry.

[0018] Optionally, in step 1, the wet-laid web-forming technology is an inclined-net scooping wet-laid web-forming technology, the inclined net has an inclination angle of 5 to 9 degrees, and a mesh size of 40 to 50;

[0019] The moisture in the wet felt of aluminum silicate fibers is removed by vacuum filtration.

[0020] Optionally, in step three, the impregnation method is selected from aerogel spraying, continuous flow impregnation tank or pool impregnation, and vacuum impregnation.

[0021] Optionally, in step 4, the hydrophobic modifier is methyl trimethylsiloxane, the reinforcing agent is boric acid; the impregnation method is one of pool impregnation, vacuum impregnation and gas impregnation;

[0022] In the preparation of aerogel, due to its porous structure, it has a large specific surface area, which is easy to absorb moisture and affect its performance. Methyltrimethoxysilane can introduce hydrophobic methyl groups on the surface of aerogel through chemical reaction, making the surface of aerogel hydrophobic, thereby reducing the adsorption of moisture. At the same time, the introduction of these organic groups can also enhance the flexibility of aerogel to a certain extent and improve its mechanical properties.

[0023] Boric acid may play the role of a cross-linking agent or reinforcing agent in this system to improve the mechanical strength and heat resistance of the material.

[0024] The immersion temperature is 25-45°C and the time is 5-30 minutes.

[0025] Optionally, in step three, the drying temperature of the microwave aging treatment is 60 to 150° C., and the time is 20 to 180 min;

[0026] In step 4, the drying temperature of the combined microwave and far infrared treatment is 60-110° C. and the drying time is 10-120 min.

[0027] The aging and drying in the prior art generally adopt the traditional hot air drying method, which is often inefficient and has high energy consumption. The present invention uses a process combining "primary microwave aging" and "secondary microwave + far infrared drying". This combination not only improves the drying speed, but also better controls the structural stability and performance changes of the product; microwave technology can heat the material more evenly, reduce thermal stress, and avoid deformation and cracking of the product.

[0028] Optionally, step five also includes post-processing, namely spraying waterproofing agent, trimming and laminating.

[0029] Optionally, the amount of each raw material is as follows: 10-70 parts by mass of aluminum silicate fiber, 0.1-2 parts by mass of dispersant, 10-40 parts by mass of inorganic aerogel silicon source solution and 30-120 parts by mass of water; the inorganic aerogel silicon source solution is obtained by dissolving lithium silicate and silica sol in acetic acid solution; 5-15 parts by mass of lithium silicate, 85-95 parts by mass of silica sol.

[0030] Optionally, the preparation raw material further comprises a hydrophobic modifier and a reinforcing agent, the hydrophobic modifier is methyltrimethoxysilane, and the reinforcing agent is boric acid.

[0031] Optionally, the hydrophobic modifier is 10 to 20 parts by mass and the reinforcing agent is 5 to 20 parts by mass.

[0032] In a second aspect, the present invention provides an aluminum silicate fiberboard prepared by the preparation method described in the first aspect.

[0033] (III) Beneficial effects

[0034] (1) The fiberboard of the present invention uses inorganic fiber as a supporting skeleton and aerogel solution as a filler. It is non-toxic and harmless, and has the characteristics of fire prevention, heat preservation and sound insulation. It has great development potential in the field of construction and can be used as interior and exterior wall surfaces in various large-scale projects such as low-energy houses, exhibition halls, museums, residential buildings, schools, hospitals, office buildings, etc. Its light weight and integrated functions have certain advantages in high-rise buildings, and it can also be used in indoor and bathroom ceilings, etc.

[0035] (2) Fiberboard can be compounded with other materials to increase its functional diversity. For example, it can be combined with inorganic artificial stone, gypsum board, glass magnesium board, cement fiberboard and other hard materials to make it a lightweight, high-strength, functionally integrated building practical board. Since inorganic materials are used in the preparation, it contributes to a new direction for the development of green, low-carbon and functionally integrated materials.

[0036] (3) The research and application of aluminum silicate fiberboard is conducive to promoting the green and low-carbon development of the building materials industry with the characteristics of "thin, light, wide and strong", and helping the country to achieve green and low-carbon building materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention is a flow chart of the preparation method of the aluminum silicate fiberboard. DETAILED DESCRIPTION

[0038] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0039] The dosage of each raw material of the aluminum silicate fiberboard of the present invention is as follows: 10-70 parts by mass of aluminum silicate fiber, 0.1-2 parts by mass of dispersant, 10-40 parts by mass of inorganic aerogel silicon source solution and 30-120 parts by mass of water; the inorganic aerogel silicon source solution is obtained by dissolving lithium silicate and silica sol in acetic acid solution; 5-15 parts by mass of lithium silicate and 85-95 parts by mass of silica sol.

[0040] The raw materials for preparing the aluminum silicate fiberboard of the present invention further comprise a hydrophobic modifier and a reinforcing agent, wherein the hydrophobic modifier is methyltrimethoxysilane and the reinforcing agent is boric acid; the hydrophobic agent comprises 10 to 20 parts by mass and the reinforcing agent comprises 5 to 20 parts by mass.

[0041] In the present invention, lithium silicate is used as a silicon source, silica sol is used as an auxiliary silicon source, and acetic acid is used as a catalyst, and an inorganic aerogel silicon source solution is formed under the combined action of the two.

[0042] The production process of the present invention combines an inorganic aerogel silicon source with an inorganic fiber, avoiding the use of organic matter, so that the product has higher fire resistance and non-flammability, while ensuring good thermal insulation and sound insulation performance; the use of inorganic materials improves the stability and environmental protection of the product.

[0043] Example 1

[0044] The method for preparing the aluminum silicate fiberboard of this embodiment comprises the following steps:

[0045] Step 1, using a dispersant polyacrylic acid amide anion to stir and break up the aluminum silicate fiber, with the stirring speed of the mixer being 500 rpm; removing slag and diluting to obtain a slurry, and using an inclined net scooping wet web forming technology to obtain an aluminum silicate fiber wet felt, wherein the inclined net has an inclination angle of 6 degrees and a mesh size of 40, and vacuum filtration is used to remove moisture to obtain an aluminum silicate fiber felt;

[0046] Step 2: dispersing lithium silicate and silica sol in an acetic acid aqueous solution to prepare an inorganic aerogel silicon source solution;

[0047] Step 3: subjecting the aluminum silicate fiber wet felt to continuous flow impregnation tank impregnation with the inorganic aerogel silicon source solution, and then subjecting it to aerogel gelation and microwave aging treatment, with a drying temperature of 130° C. for 30 min to obtain a primary aluminum silicate fiberboard;

[0048] Step 4: The primary aluminum silicate fiberboard is vacuum impregnated with a mixed solution of a hydrophobic modifier, methyl trimethylsiloxane, and a reinforcing agent, boric acid, at a temperature of 30° C. for 25 min; and then subjected to a combined microwave and far infrared treatment at a drying temperature of 70° C. for 100 min.

[0049] Step 5: Adjust thickness and cut to size, then spray waterproofing agent, trim and coat to obtain aluminum silicate fiberboard.

[0050] The amounts of the raw materials of the aluminum silicate fiberboard of this embodiment are as follows: 10Kg of aluminum silicate fiber, 0.1Kg of polyacrylamide anion, 10Kg of inorganic aerogel silicon source solution, 10Kg of methyl trimethylsiloxane, 5Kg of boric acid and 30Kg of water;

[0051] The inorganic aerogel silicon source solution is obtained by dissolving lithium silicate and silica sol in acetic acid solution; 5 kg of lithium silicate and 95 kg of silica sol.

[0052] Example 2

[0053] The method for preparing the aluminum silicate fiberboard of this embodiment comprises the following steps:

[0054] Step 1, using sodium hexametaphosphate as a dispersant to stir and break up the aluminum silicate fiber, with the stirring speed of the mixer being 2000 rpm; removing slag and diluting to obtain a slurry, and using an inclined net scooping wet web forming technology to obtain an aluminum silicate fiber wet felt, wherein the inclined net has an inclination angle of 9 degrees and a mesh size of 50, and vacuum filtration is used to remove moisture to obtain an aluminum silicate fiber felt;

[0055] Step 2: dispersing lithium silicate and silica sol in an acetic acid aqueous solution to prepare an inorganic aerogel silicon source solution;

[0056] Step 3: vacuum impregnating the aluminum silicate fiber wet felt with the inorganic aerogel silicon source solution, and then subjecting it to aerogel gelation and microwave aging treatment at a drying temperature of 80° C. for 150 min to obtain a primary aluminum silicate fiberboard;

[0057] Step 4: The primary aluminum silicate fiberboard is vacuum impregnated with a mixed solution of methyl trimethylsiloxane, a hydrophobic modifier, and boric acid, a reinforcing agent, at a temperature of 40° C. for 10 min; and then subjected to a combined microwave and far infrared treatment at a drying temperature of 100° C. for 30 min;

[0058] Step 5: Adjust thickness and cut to size, then spray waterproofing agent, trim and coat to obtain aluminum silicate fiberboard.

[0059] The amounts of the raw materials of the aluminum silicate fiberboard of this embodiment are as follows: 70 kg of aluminum silicate fiber, 2 kg of sodium hexametaphosphate, 40 kg of inorganic aerogel silicon source solution, 20 kg of methyl trimethylsiloxane, 20 kg of boric acid and 120 kg of water;

[0060] The inorganic aerogel silicon source solution is obtained by dissolving lithium silicate and silica sol in acetic acid solution; 15 kg of lithium silicate and 85 kg of silica sol.

[0061] Example 3

[0062] The method for preparing the aluminum silicate fiberboard of this embodiment comprises the following steps:

[0063] Step 1, using a dispersant sodium polyacrylate to stir and break up the aluminum silicate fiber, the mixer speed is 1000 rpm; and removing slag and diluting to obtain a slurry, using an inclined net scooping wet web forming technology to obtain an aluminum silicate fiber wet felt, wherein the inclined net has an inclination angle of 7 degrees and a mesh size of 45, and vacuum filtration is used to remove moisture to obtain an aluminum silicate fiber felt;

[0064] Step 2: dispersing lithium silicate and silica sol in an acetic acid aqueous solution to prepare an inorganic aerogel silicon source solution;

[0065] Step 3: The aluminum silicate fiber wet felt is immersed in the inorganic aerogel silicon source solution, and then subjected to aerogel gelation and microwave aging treatment at a drying temperature of 100° C. for 100 min to obtain a primary aluminum silicate fiberboard;

[0066] Step 4: The primary aluminum silicate fiberboard is vacuum impregnated with a mixed solution of a hydrophobic modifier, methyl trimethylsiloxane, and a reinforcing agent, boric acid, at a temperature of 40° C. for 20 min; and then subjected to a combined microwave and far infrared treatment at a drying temperature of 90° C. for 80 min.

[0067] Step 5: Adjust thickness and cut to size, then spray waterproofing agent, trim and coat to obtain aluminum silicate fiberboard.

[0068] The amounts of the raw materials of the aluminum silicate fiberboard of this embodiment are as follows: 40 kg of aluminum silicate fiber, 1 kg of sodium polyacrylate, 25 kg of inorganic aerogel silicon source solution, 15 kg of methyl trimethylsiloxane, 12 kg of boric acid and 80 kg of water;

[0069] The inorganic aerogel silicon source solution is obtained by dissolving lithium silicate and silica sol in acetic acid solution; 10 kg of lithium silicate and 90 kg of silica sol.

[0070] Comparative Example 1

[0071] The amounts of the raw materials used in the aluminum silicate fiberboard of this comparative example are as follows: 800 kg of water, 8 kg of aluminum silicate fiber, 150 kg of organic binder CMC (sodium carboxymethyl cellulose), 0.5 kg of a mixture of bentonite and kaolin as additives, and 3 kg of a modifier polyacrylamide.

[0072] Comparative Example 2

[0073] The dosage of each raw material of the aluminum silicate fiberboard of this comparative example is as follows: 60 kg of aluminum silicate fiber, 5 kg of organic binder corn starch, and 20 kg of reinforcing auxiliary agent alkali-free glass fiber powder.

[0074] Test example

[0075] Thermal conductivity: Tested in accordance with "YB / T 4130-2005 Test method for thermal conductivity of refractory materials";

[0076] Combustion performance: tested in accordance with GB / T 5464-2010 Test method for non-combustibility of building materials;

[0077] Bulk density Kg / m 3 :The test is carried out using GB / T 17911-2006 Test methods for refractory ceramic fiber products;

[0078] The compressive strength is MPa and is tested using the "GB / T5072-2008 Test method for compressive strength of refractory materials at room temperature".

[0079] Table 1 Various properties of aluminum silicate fiberboards of Examples 1-3 of the present invention and Comparative Examples 1-2

[0080]

[0081] The production process of the present invention combines inorganic aerogel silicon source with inorganic fiber, so that the product has higher fire resistance and non-flammability, while ensuring good thermal insulation and sound insulation performance.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an aluminum silicate fiberboard, characterized in that: The steps include: Step 1: using a dispersant to stir and disperse the aluminum silicate fibers, remove the slag, and dilute to obtain a slurry, using a wet-laid web forming technology to obtain an aluminum silicate fiber wet felt, and removing moisture to obtain an aluminum silicate fiber felt; Step 2: dispersing lithium silicate and silica sol in an acetic acid aqueous solution to prepare an inorganic aerogel silicon source solution; Step 3: impregnating the aluminum silicate fiber wet felt with the inorganic aerogel silicon source solution, and then performing aerogel gelation and microwave aging treatment to obtain a primary aluminum silicate fiber board; Step 4: the primary aluminum silicate fiberboard is impregnated with a mixed solution of a hydrophobic modifier and a reinforcing agent, and then subjected to a combined microwave and far infrared treatment; Step 5: Adjust thickness and cut to size to obtain aluminum silicate fiberboard.

2. The preparation method according to claim 4, characterized in that: In step 1, the speed of the mixer is 500 to 2000 rpm; The dispersant is selected from one or more of polyacrylic acid amide anion, polyacrylic acid amide cation, sodium hexametaphosphate, sodium tripolyphosphate, sodium polyacrylate, and hydroxypropyl methylcellulose HPMC.

3. The preparation method according to claim 4, characterized in that: In step 1, the wet-laid web-forming technology is an inclined-net scooping wet-laid web-forming technology, the inclined net has an inclination angle of 5 to 9 degrees, and a mesh size of 40 to 50; The moisture in the wet felt of aluminum silicate fibers is removed by vacuum filtration.

4. The preparation method according to claim 4, characterized in that: In step three, the impregnation method is selected from one of aerogel spraying, continuous flow impregnation tank or pool impregnation, and vacuum impregnation.

5. The preparation method according to claim 4, characterized in that: In step 4, the hydrophobic modifier is methyl trimethylsiloxane, the reinforcing agent is boric acid; the impregnation method is one of pool impregnation, vacuum impregnation and gas impregnation; The immersion temperature is 25-45°C and the time is 5-30 minutes.

6. The preparation method according to claim 4, characterized in that: In step 3, the drying temperature of the microwave aging treatment is 60-150° C. and the time is 20-180 min; In step 4, the drying temperature of the combined microwave and far infrared treatment is 60-110° C. and the drying time is 10-120 min.

7. The preparation method according to claim 4, characterized in that: Step five also includes post-processing, namely spraying waterproofing agent, trimming and laminating.

8. The preparation method according to claim 1, characterized in that: The dosage of each raw material is as follows: 10-70 parts by weight of aluminum silicate fiber, 0.1-2 parts by weight of dispersant, 10-40 parts by weight of inorganic aerogel silicon source solution and 30-120 parts by weight of water; the inorganic aerogel silicon source solution is obtained by dissolving lithium silicate and silica sol in acetic acid solution; 5-15 parts by weight of lithium silicate and 85-95 parts by weight of silica sol.

9. The preparation method according to claim 8, characterized in that: The preparation raw materials also contain a hydrophobic modifier and a reinforcing agent, wherein the hydrophobic modifier is methyltrimethoxysilane and the reinforcing agent is boric acid.

10. An aluminum silicate fiberboard, characterized in that: The method is prepared by any one of claims 1 to 9.

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