Lightweight vermiculite insulation board and preparation method thereof

Abstract

The invention provides a light vermiculite insulation board and a preparation method thereof, and particularly relates to the technical field of insulation boards. The light vermiculite insulation board comprises a flexible magnesium oxychloride cementing material, expanded vermiculite, inorganic fibers, a film-forming agent and a film-forming curing agent. The flexible magnesium oxychloride cementing material comprises a first component and a second component, the first component comprises an ethylene-vinyl acetate copolymer emulsion, a silicone acrylic emulsion, magnesium chloride hexahydrate, a thickening time control agent and water; the second component comprises light calcined magnesia. The light vermiculite insulation board has the characteristics of light weight, high strength, low heat conductivity and water resistance, is suitable for building envelope structures with higher requirements on weight, heat preservation and durability, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation board technology, and in particular to a lightweight vermiculite thermal insulation board and its preparation method. Background Technology

[0002] Vermiculite board, as a common thermal insulation material, possesses certain thermal insulation and fire-resistant properties, but its practical application faces several limitations, primarily in its physical properties and durability. Firstly, conventional vermiculite board has relatively low strength, making it highly susceptible to damage during transportation and construction. This not only increases material waste but can also lead to a decline in construction quality. Furthermore, vermiculite board is highly absorbent, which not only reduces its insulation performance but can also cause mold growth in humid environments, thus affecting its durability. This water absorption problem is particularly pronounced with long-term use, especially in humid environments, where the performance of vermiculite board gradually declines, significantly shortening its lifespan.

[0003] To improve the performance of vermiculite boards, organic adhesives such as polyurethane are typically used for bonding. However, while this approach improves the strength of vermiculite boards to some extent, it also introduces new problems. Polyurethane and other organic adhesives are not only expensive, but they are also prone to mold growth in humid environments. This not only affects the appearance of the vermiculite boards but may also pose a potential threat to the structural safety of buildings. Furthermore, the use of organic adhesives increases the production cost of vermiculite boards, which limits their market promotion and use, especially in cost-sensitive construction projects where this high-cost material is often not considered.

[0004] On the other hand, while inorganic adhesives have good compatibility with vermiculite, they also have significant drawbacks in practical applications. Inorganic adhesives are generally quite brittle, meaning they have limited ability to improve the strength of vermiculite boards, especially when faced with significant external impacts, where the boards remain prone to cracking. This brittleness not only affects the toughness of the vermiculite boards but also limits their use in applications requiring higher toughness. Therefore, although inorganic adhesives have addressed the durability issues of organic adhesives to some extent, their ability to improve the overall performance of vermiculite boards remains significantly limited.

[0005] In summary, vermiculite boards face numerous challenges in practical applications, including insufficient strength, high water absorption, poor durability, and high cost. These issues not only affect the market competitiveness of vermiculite boards but also limit their widespread application in building insulation. Therefore, developing a new type of vermiculite board material that possesses both high strength and toughness while effectively addressing the problems of water absorption and durability has become an important direction in current building materials research.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a lightweight vermiculite insulation board and its preparation method, so as to alleviate at least one of the above-mentioned technical problems in the prior art.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A first aspect of the present invention provides a lightweight vermiculite insulation board, comprising a flexible magnesium oxychloride cementitious material, expanded vermiculite, inorganic fibers, a film-forming agent, and a film-forming curing agent; The flexible magnesium oxychloride gelling material comprises a first component and a second component; the first component comprises ethylene-vinyl acetate copolymer emulsion, silicone-acrylic emulsion, magnesium chloride hexahydrate, setting regulator and water; the second component comprises lightly calcined magnesium oxide.

[0009] Furthermore, the lightweight vermiculite insulation board, by weight, comprises the following components: the first component includes 0.5-1 parts of ethylene-vinyl acetate copolymer emulsion, 0.5-2 parts of silicone-acrylic emulsion, 3.3-5.6 parts of magnesium chloride hexahydrate, 0.03-0.7 parts of setting regulator, and 1.5-4.5 parts of water; the second component includes 10 parts of lightly calcined magnesium oxide.

[0010] Furthermore, the lightweight vermiculite insulation board, by weight, comprises 16-24 parts of flexible magnesium oxychloride cementitious material, 40-60 parts of expanded vermiculite, 2-6 parts of inorganic fiber, 0.5-1.5 parts of film-forming agent, and 0.01-0.2 parts of film-forming curing agent.

[0011] Furthermore, the Brookfield viscosity of the ethylene-vinyl acetate copolymer emulsion is 1300~4000 cps.

[0012] Preferably, the solid content of the ethylene-vinyl acetate copolymer emulsion is 50-60%.

[0013] Furthermore, the active magnesium oxide content in the lightly calcined magnesium oxide is 60-65%.

[0014] Furthermore, the setting agent includes at least one of citric acid, oxalic acid, and phosphoric acid.

[0015] Preferably, the film-forming agent includes sodium silicate and polyvinyl alcohol.

[0016] Preferably, the film-forming curing agent includes sodium fluorosilicate and glycol.

[0017] Furthermore, the inorganic fiber includes at least one of sepiolite fiber, basalt fiber, glass fiber, and ceramic fiber.

[0018] The second aspect of the present invention provides a method for preparing the lightweight vermiculite insulation board, wherein expanded vermiculite, inorganic fiber, a second component, a film-forming agent and a film-forming curing agent are added to a first component and stirred evenly to obtain a slurry. The slurry is then poured into a mold for installation and molding. After pre-pressing, cold pressing and curing, a lightweight vermiculite insulation board is obtained.

[0019] Furthermore, the cold pressing pressure is 0.2~1MPa, and the time is 12~36h.

[0020] Furthermore, the curing temperature is 20~25℃, the humidity is 50~65%RH, and the time is 7~14 days.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects: The lightweight vermiculite insulation board provided by this invention has a density of only 180~300 kg / m³. 3 This lightweight vermiculite insulation board significantly reduces building load, facilitating transportation and construction. With compressive strength ranging from 0.75 to 1.70 MPa and tensile strength from 0.25 to 0.52 MPa, it meets building load-bearing requirements while exhibiting good crack resistance and structural stability. Its thermal conductivity is 0.036 to 0.075 W / (m·K), providing excellent insulation performance and effectively reducing building energy consumption. With a volumetric water absorption rate of only 1.3% to 3.9%, it is resistant to humid environments and is not easily degraded by moisture over long-term use. This lightweight vermiculite insulation board combines lightweight, high strength, low thermal conductivity, and water resistance, making it suitable for building envelopes with high requirements for weight, insulation, and durability, and has broad application prospects.

[0022] The method for preparing lightweight vermiculite insulation board provided by this invention employs pre-pressing and cold-pressing processes, which effectively reduces internal porosity of the material and improves the density and mechanical strength of the insulation board. Secondly, by optimizing the slurry ratio and molding process, it ensures uniform dispersion of expanded vermiculite and inorganic fibers, enhancing the material's crack resistance and toughness. Furthermore, the combination of cold-pressing and curing processes reduces energy consumption, improves production efficiency, and ensures product dimensional stability and durability. Finally, this preparation method is simple to operate and easy to industrialize, and the resulting lightweight vermiculite insulation board possesses excellent thermal insulation performance, mechanical properties, and water resistance, making it suitable for the field of building energy conservation. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of the invention, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0025] A first aspect of the present invention provides a lightweight vermiculite insulation board, comprising a flexible magnesium oxychloride cementitious material, expanded vermiculite, inorganic fibers, a film-forming agent, and a film-forming curing agent; The flexible magnesium oxychloride gelling material comprises a first component and a second component; the first component comprises ethylene-vinyl acetate copolymer emulsion, silicone-acrylic emulsion, magnesium chloride hexahydrate, setting regulator and water; the second component comprises lightly calcined magnesium oxide.

[0026] The lightweight vermiculite insulation board provided by this invention has a density of only 180~300 kg / m³. 3 This lightweight vermiculite insulation board significantly reduces building load, facilitating transportation and construction. With compressive strength ranging from 0.75 to 1.70 MPa and tensile strength from 0.25 to 0.52 MPa, it meets building load-bearing requirements while exhibiting good crack resistance and structural stability. Its thermal conductivity is 0.036 to 0.075 W / (m·K), providing excellent insulation performance and effectively reducing building energy consumption. With a volumetric water absorption rate of only 1.3% to 3.9%, it is resistant to humid environments and is not easily degraded by moisture over long-term use. This lightweight vermiculite insulation board combines lightweight, high strength, low thermal conductivity, and water resistance, making it suitable for building envelopes with high requirements for weight, insulation, and durability, and has broad application prospects.

[0027] In lightweight vermiculite insulation boards, the ethylene-vinyl acetate copolymer emulsion, due to its good viscosity and fluidity, can penetrate into the intercalation structure of expanded vermiculite, thereby enhancing the bonding ability between the polymer matrix and the expanded vermiculite. Simultaneously, the hydroxyl groups generated by its hydrolysis can adsorb silicone-acrylic emulsion particles to improve the film-forming properties of the polymer matrix, thus enhancing the mechanical properties of the board. The silicone-acrylic emulsion, with its excellent film-forming properties and the interpenetrating network structure formed by its carboxyl groups and magnesium oxychloride cementitious material, can adsorb magnesium oxychloride cementitious material particles, enhancing the toughness of the adhesive layer. Furthermore, its sterically hindered hydrophobic groups -Si(OCH3)... This further enhances the water resistance of the adhesive layer; the inorganic fiber has good compatibility with magnesium oxychloride cementitious material, which can not only effectively improve the crack resistance of the adhesive matrix, but also improve the brittleness of vermiculite, thus playing a role in strengthening and toughening; the film-forming agent and the film-forming curing agent react and cure to form a film, which not only improves the water resistance of vermiculite and magnesium oxychloride cementitious material, but also plays an auxiliary adhesive role. In addition, the foam-like porous expansion layer formed by heating when using sodium silicate film-forming agent and the network Si-O-Si structure composed of silicate short chains further enhance the flame retardant properties and thermal stability of vermiculite material.

[0028] Furthermore, the lightweight vermiculite insulation board, by weight, comprises the following components: the first component includes 0.5-1 parts of ethylene-vinyl acetate copolymer emulsion, 0.5-2 parts of silicone-acrylic emulsion, 3.3-5.6 parts of magnesium chloride hexahydrate, 0.03-0.7 parts of setting regulator, and 1.5-4.5 parts of water; the second component includes 10 parts of lightly calcined magnesium oxide.

[0029] Typically, but not limitingly, in the first component of lightweight vermiculite insulation board, the amount of ethylene-vinyl acetate copolymer emulsion can be, for example, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, or 1 part, or any value within the range of 0.5 parts to 1 part; the amount of silicone-acrylic emulsion can be, for example, 0.5 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, or 2 parts, or any value within the range of 0.5 parts to 2 parts; the amount of magnesium chloride hexahydrate can be, for example, 3.3 parts, 3.8 parts, ... The dosage of the coagulant can be 4.2 parts, 4.7 parts, or 5.6 parts, or any value within the range of 3.3 parts to 5.6 parts; the dosage of the setting agent can be, for example, 0.03 parts, 0.05 parts, 0.08 parts, 0.1 parts, 0.3 parts, 0.5 parts, or 0.7 parts, or any value within the range of 0.03 parts to 0.7 parts; the dosage of water can be, for example, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 3.8 parts, 4 parts, 4.2 parts, or 4.5 parts, or any value within the range of 1.5 parts to 4.5 parts. In the second component, the dosage of lightly calcined magnesium oxide is 10 parts.

[0030] Furthermore, the lightweight vermiculite insulation board, by weight, comprises 16-24 parts of flexible magnesium oxychloride cementitious material, 40-60 parts of expanded vermiculite, 2-6 parts of inorganic fiber, 0.5-1.5 parts of film-forming agent, and 0.01-0.2 parts of film-forming curing agent.

[0031] Typical, but not limiting, components of lightweight vermiculite insulation boards may include: flexible magnesium oxychloride cementitious material in quantities of, for example, 16, 18, 20, 22, or 24 parts, or any value within the range of 16 to 24 parts; expanded vermiculite in quantities of, for example, 40, 45, 50, 55, or 60 parts, or any value within the range of 40 to 60 parts; and inorganic fibers in quantities of, for example, 2, 3, or 4 parts. The amount of film-forming agent can be 0.5, 0.7, 1, 1.2, or 1.5 parts, or any value within the range of 0.5 to 1.5 parts; the amount of film-forming curing agent can be 0.01, 0.02, 0.05, 0.1, 0.15, or 0.2 parts, or any value within the range of 0.01 to 0.2 parts.

[0032] Furthermore, the Brookfield viscosity of the ethylene-vinyl acetate copolymer emulsion is 1300~4000 cps.

[0033] Typically, but not limitingly, the Brookfield viscosity of the ethylene-vinyl acetate copolymer emulsion may be, for example, 1300 cps, 1500 cps, 1800 cps, 2000 cps, 2500 cps, 3000 cps, 3500 cps or 4000 cps, or any value in the range of 1300 cps to 4000 cps.

[0034] Preferably, the solid content of the ethylene-vinyl acetate copolymer emulsion is 50-60%.

[0035] Typically, but not limitingly, the solid content of the ethylene-vinyl acetate copolymer emulsion can be, for example, 50%, 52%, 55%, 58% or 60%, or any value within the range of 50% to 60%.

[0036] Furthermore, the active magnesium oxide content in the lightly calcined magnesium oxide is 60-65%.

[0037] Typically, but not limitingly, the active magnesium oxide content in the lightly calcined magnesium oxide can be, for example, 60%, 61%, 62%, 63%, 64% or 65%, or any value within the range of 60% to 65%.

[0038] Furthermore, the setting agent includes at least one of citric acid, oxalic acid, and phosphoric acid.

[0039] Preferably, the film-forming agent includes sodium silicate and polyvinyl alcohol.

[0040] Preferably, the film-forming curing agent includes sodium fluorosilicate and glycol.

[0041] Furthermore, the inorganic fiber includes at least one of sepiolite fiber, basalt fiber, glass fiber, and ceramic fiber.

[0042] The second aspect of the present invention provides a method for preparing the lightweight vermiculite insulation board, wherein expanded vermiculite, inorganic fiber, a second component, a film-forming agent and a film-forming curing agent are added to a first component and stirred evenly to obtain a slurry. The slurry is then poured into a mold for installation and molding. After pre-pressing, cold pressing and curing, a lightweight vermiculite insulation board is obtained.

[0043] The method for preparing lightweight vermiculite insulation board provided by this invention employs pre-pressing and cold-pressing processes, which effectively reduces internal porosity of the material and improves the density and mechanical strength of the insulation board. Secondly, by optimizing the slurry ratio and molding process, it ensures uniform dispersion of expanded vermiculite and inorganic fibers, enhancing the material's crack resistance and toughness. Furthermore, the combination of cold-pressing and curing processes reduces energy consumption, improves production efficiency, and ensures product dimensional stability and durability. Finally, this preparation method is simple to operate and easy to industrialize, and the resulting lightweight vermiculite insulation board possesses excellent thermal insulation performance, mechanical properties, and water resistance, making it suitable for the field of building energy conservation.

[0044] The first component is prepared by mixing the raw materials in the first component.

[0045] Furthermore, the cold pressing pressure is 0.2~1MPa, and the time is 12~36h.

[0046] Typically, but not limitingly, the cold pressing pressure can be, for example, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, or 1 MPa, or any value within the range of 0.2 MPa to 1 MPa; the cold pressing time can be, for example, 12 h, 15 h, 18 h, 21 h, 24 h, 27 h, 30 h, 33 h, or 36 h, or any value within the range of 12 h to 36 h.

[0047] Furthermore, the curing temperature is 20~25℃, the humidity is 50~65%RH, and the time is 7~14 days.

[0048] Typically, but not limitingly, the curing temperature can be, for example, 20°C, 21°C, 22°C, 23°C, 24°C, or 25°C, or any value within the range of 20°C to 25°C; the curing humidity can be, for example, 50% RH, 52% RH, 55% RH, 58% RH, 60% RH, 62% RH, or 65% RH, or any value within the range of 50% RH to 65% RH; the curing time can be, for example, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, or 14 days, or any value within the range of 7 days to 14 days.

[0049] The present invention is further illustrated below with specific embodiments and comparative examples. However, it should be understood that these embodiments are merely for illustrative purposes and should not be construed as limiting the invention in any way. Unless otherwise specified, the raw materials used in the embodiments and comparative examples of the present invention were carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0050] Example 1 This embodiment provides a lightweight vermiculite insulation board, the preparation method of which is as follows: 1. Weigh 0.5 kg of ethylene-vinyl acetate copolymer emulsion, 0.5 kg of silicone-acrylic emulsion, 5 kg of magnesium chloride hexahydrate, 3 kg of water, and 0.03 kg of citric acid as a setting regulator to prepare the first component.

[0051] 2. After the first component is mixed evenly with 40 kg of expanded vermiculite and 2 kg of basalt fiber, 10 kg of lightly calcined magnesium oxide, 0.6 kg of sodium silicate and 0.06 kg of sodium fluorosilicate are added and mixed thoroughly to obtain the vermiculite insulation board raw material.

[0052] 3. The above-mentioned vermiculite insulation board raw material is laid in a mold and pre-pressed. After cold pressing at room temperature of 30℃ and pressure of 0.2 MPa for 12 hours, it is cut and shaped. It is then cured at 25℃ and 65%RH humidity for 7 days to obtain lightweight vermiculite insulation board.

[0053] Example 2 This embodiment provides a lightweight vermiculite insulation board, the preparation method of which is as follows: 1. Weigh 1 kg of ethylene-vinyl acetate copolymer emulsion, 2 kg of silicone-acrylic emulsion, 3.5 kg of magnesium chloride hexahydrate, 4.6 kg of water, and 0.06 kg of phosphoric acid as a setting regulator to prepare the first component.

[0054] 2. After the first component is mixed evenly with 60 kg of expanded vermiculite and 6 kg of sepiolite fiber, 10 kg of lightly calcined magnesium oxide, 1.2 kg of sodium silicate and 0.18 kg of sodium fluorosilicate are added and mixed thoroughly to obtain vermiculite insulation board raw material.

[0055] 3. The above-mentioned vermiculite insulation board raw material is laid in a mold and pre-pressed. After being cold-pressed at 0℃ and 1 MPa for 36 hours, it is cut and shaped. It is then cured at 20℃ and 50%RH for 14 days to obtain a lightweight vermiculite insulation board.

[0056] Example 3 This embodiment provides a lightweight vermiculite insulation board, the preparation method of which is as follows: 1. Weigh 0.5 kg of ethylene-vinyl acetate copolymer emulsion, 0.5 kg of silicone-acrylic emulsion, 4 kg of magnesium chloride hexahydrate, 4.5 kg of water, and 0.04 kg of oxalic acid as a coagulant to prepare the first component.

[0057] 2. After the first component is mixed evenly with 50 kg of expanded vermiculite and 3 kg of ceramic fiber, 10 kg of lightly calcined magnesium oxide, 0.7 kg of sodium silicate and 0.08 kg of sodium fluorosilicate are added and mixed thoroughly to obtain the vermiculite insulation board raw material.

[0058] 3. The above-mentioned vermiculite insulation board raw material is laid in a mold and pre-pressed. After being cold-pressed at room temperature of 25℃ and pressure of 0.5 MPa for 24 hours, it is cut and shaped. It is then cured at 25℃ and 60%RH humidity for 12 days to obtain lightweight vermiculite insulation board.

[0059] Comparative Example 1 This comparative example provides a lightweight vermiculite insulation board. Unlike Example 3, the raw materials do not use ethylene-vinyl acetate copolymer emulsion. The other raw materials and amounts are the same as in Example 3, and will not be repeated here.

[0060] Comparative Example 2 This comparative example provides a lightweight vermiculite insulation board. Unlike Example 3, silicone-acrylic emulsion is not used in the raw materials. The other raw materials and amounts are the same as in Example 3, and will not be described again here.

[0061] Comparative Example 3 This comparative example provides a lightweight vermiculite insulation board. Unlike Example 3, ceramic fibers are not used in the raw materials. The other raw materials and quantities are the same as in Example 3, and will not be described again here.

[0062] Comparative Example 4 This comparative example provides a lightweight vermiculite insulation board. Unlike Example 3, sodium silicate and sodium fluorosilicate are not used in the raw materials. Basalt fiber is used instead of ceramic fiber. The other raw materials and dosages are the same as in Example 3, and will not be repeated here.

[0063] Comparative Example 5 This comparative example provides a lightweight vermiculite insulation board. Unlike Example 3, oxalic acid is not used in the raw materials. The other raw materials and their amounts are the same as in Example 3, and will not be described again here.

[0064] Test case The lightweight vermiculite insulation boards obtained in the above embodiments and comparative examples were subjected to performance tests, including density, compressive strength, thermal conductivity, and volume water absorption rate, specifically in accordance with the requirements of JC / T 2341-2015 "Expanded Vermiculite Fireproof Board".

[0065] Table 1 Performance data of lightweight vermiculite insulation board

[0066] As can be seen from Examples 1-3, the lightweight vermiculite insulation board prepared according to the appropriate raw material ratio meets the performance requirements of wall insulation materials in JC / T2341-2015 "Expanded Vermiculite Fireproof Board", and the performance of the sample prepared in this application is significantly better than the standard requirements.

[0067] As can be seen from Comparative Example 1 and Example 3, without the addition of ethylene-vinyl acetate copolymer emulsion, the tensile strength of the resulting board significantly decreased, falling below the standard value, and the volumetric water absorption significantly increased. This is because the ethylene-vinyl acetate copolymer emulsion has good viscosity and flowability, forming an interpenetrating network structure with the magnesium oxychloride cementitious material, which effectively improves the toughness of the matrix. Simultaneously, it can densify the voids in the magnesium oxychloride cementitious material, improving the water resistance of the matrix. Furthermore, without the ethylene-vinyl acetate copolymer emulsion, the silicone-acrylic emulsion is not easily dispersed evenly, thus affecting its effect on improving the water resistance of the matrix.

[0068] As can be seen from Comparative Example 2 and Example 3, without the addition of silicone-acrylic emulsion, the volume water absorption rate of the board is significantly increased, while the tensile strength of the matrix is ​​also significantly reduced. This is because silicone-acrylic emulsion can form a synergistic effect with ethylene-vinyl acetate, enhancing the bonding ability between magnesium oxychloride cementitious material and vermiculite, thus realizing the preparation of lightweight insulation board.

[0069] As can be seen from Comparative Example 3 and Example 3, without the addition of inorganic fibers, the compressive strength and tensile strength of the finished board both decrease significantly. This is because the fiber structure of inorganic fibers can disperse the pressure of the vermiculite insulation board and play a role in reinforcing and toughening. At the same time, its fiber reinforcement can effectively disperse tensile stress and improve the tensile strength of the vermiculite insulation board.

[0070] As can be seen from Comparative Example 4 and Example 3, without the addition of sodium silicate and sodium fluorosilicate, the water resistance and compressive strength of the slab decreased to varying degrees. This is because the film-forming effect of sodium silicate penetrates between vermiculite and magnesium oxychloride cementitious materials, enhancing their bonding performance. Simultaneously, the cured sodium silicate exhibits good waterproofing and dense filling properties, thereby reducing the volumetric water absorption rate of the slab.

[0071] As can be seen from Comparative Example 5 and Example 3, without the addition of setting regulators such as oxalic acid, the magnesium oxychloride cementitious material cures quickly, and the pressing process produces significant heat release. Some of the lightly calcined magnesium oxide reacts to form magnesium hydroxide, which affects the bonding performance of the magnesium oxychloride cementitious material to vermiculite, and thus affects the mechanical properties of the finished board. At the same time, excessively high magnesium hydroxide content leads to a significant increase in the volumetric water absorption rate of the finished board.

[0072] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A lightweight vermiculite insulation board, characterized in that, Including flexible magnesium oxychloride cementitious materials, expanded vermiculite, inorganic fibers, film-forming agents, and film-forming curing agents; The flexible magnesium oxychloride gelling material includes a first component and a second component. The first component includes ethylene-vinyl acetate copolymer emulsion, silicone-acrylic emulsion, magnesium chloride hexahydrate, setting regulator, and water; The second component includes lightly calcined magnesium oxide.

2. The lightweight vermiculite insulation board according to claim 1, characterized in that, Based on parts by weight, the first component comprises 0.5 to 1 part of ethylene-vinyl acetate copolymer emulsion, 0.5 to 2 parts of silicone-acrylic emulsion, 3.3 to 5.6 parts of magnesium chloride hexahydrate, 0.03 to 0.7 parts of setting regulator, and 1.5 to 4.5 parts of water; The second component comprises 10 parts by weight of lightly calcined magnesium oxide.

3. The lightweight vermiculite insulation board according to claim 1, characterized in that, The composition, by weight, includes 16-24 parts of flexible magnesium oxychloride cementitious material, 40-60 parts of expanded vermiculite, 2-6 parts of inorganic fiber, 0.5-1.5 parts of film-forming agent, and 0.01-0.2 parts of film-forming curing agent.

4. The lightweight vermiculite insulation board according to any one of claims 1 to 3, characterized in that, The Brookfield viscosity of the ethylene-vinyl acetate copolymer emulsion is 1300~4000 cps; Preferably, the solid content of the ethylene-vinyl acetate copolymer emulsion is 50-60%.

5. The lightweight vermiculite insulation board according to any one of claims 1 to 3, characterized in that, The active magnesium oxide content in the lightly calcined magnesium oxide is 60-65%.

6. The lightweight vermiculite insulation board according to any one of claims 1 to 3, characterized in that, The setting agent includes at least one of citric acid, oxalic acid, and phosphoric acid; Preferably, the film-forming agent includes sodium silicate and polyvinyl alcohol; Preferably, the film-forming curing agent includes sodium fluorosilicate and glycol.

7. The lightweight vermiculite insulation board according to any one of claims 1 to 3, characterized in that, The inorganic fibers include at least one of sepiolite fiber, basalt fiber, glass fiber, and ceramic fiber.

8. A method for preparing the lightweight vermiculite insulation board according to any one of claims 1 to 7, characterized in that, Expanded vermiculite, inorganic fiber, second component, film-forming agent and film-forming curing agent are added to the first component and stirred evenly to obtain a slurry. The slurry is then poured into a mold for installation and shaping. After pre-pressing, cold pressing and curing, a lightweight vermiculite insulation board is obtained.

9. The preparation method according to claim 8, characterized in that, The cold pressing pressure is 0.2~1MPa, and the time is 12~36h.

10. The preparation method according to claim 8, characterized in that, The curing temperature is 20~25℃, the humidity is 50~65%RH, and the time is 7~14 days.

Images