Soluble fiber inorganic ceramic plate and preparation method thereof

Abstract

The invention provides a soluble fiber inorganic ceramic plate and a preparation method thereof, and the method comprises the following steps: S10: carrying out polysiloxane coating treatment on soluble ceramic fibers to obtain modified soluble ceramic fibers; wherein the polysiloxane contains an amino group; s20, dispersing the modified soluble ceramic fibers in water to obtain a first mixed solution; s30, adding an epoxy silane coupling agent into the silica sol binder to graft epoxy groups on the surface of silicon dioxide in the silica sol binder to obtain a second mixed solution; and S40, mixing the first mixed solution and the second mixed solution to obtain slurry, performing wet vacuum forming on the slurry, and drying to obtain the soluble fiber inorganic ceramic plate. The soluble fiber inorganic ceramic plate obtained by the method has good moisture resistance and strength.

Description

Technical Field

[0001] The present application relates to the technical field of fiberboards, and in particular to a soluble fiber inorganic ceramic board and a preparation method thereof. Background Art

[0002] Traditional ceramic fiber products are primarily composed of Al2O3 and SiO2. These ceramic fibers, when manufactured and used in other thermal insulation materials, suffer from fatal flaws: Their small diameters, mostly below 6μm, are also brittle and easily break, producing fiber dust that can be easily inhaled, potentially impacting health. Soluble ceramic fiber is an alkaline earth silicate fiber primarily composed of SiO2, MgO, and CaO. Its solubility in body fluids reduces any potential health risks, shortening its residence time in the body and minimizing or preventing any potential health damage. Therefore, soluble fiber inorganic ceramic boards made from soluble ceramic fibers are expected to replace conventional inorganic ceramic boards in certain applications and represent an important development direction in this field.

[0003] Compared with ceramic fibers, soluble ceramic fibers generally have a higher silica content and are generally glassy fibers. They have stronger hygroscopicity, which may cause the soluble ceramic fibers to absorb moisture during use, weakening the bonding force between the soluble ceramic fibers and the binder. In addition, water can also dissolve the alkali metal oxides in the soluble ceramic fibers, which will cause the strength of the soluble fiber inorganic ceramic board to decrease.

[0004] Patent CN118756526A discloses an inorganic soluble fiberboard and a method for preparing the same. The method comprises the following steps: S10: dispersing inorganic soluble fibers, a silica sol binder, and an unsaturated silane coupling agent in water, grafting unsaturated carbon-carbon bonds onto the surfaces of the inorganic soluble fibers and the silica sol to obtain a mixed solution; S20: adding an acrylamide monomer and a crosslinking agent to the mixed solution, initiating a polymerization reaction and flocculating the mixture to obtain a slurry; S30: wet vacuum forming the slurry, and drying the resulting inorganic soluble fiberboard. According to the present application, the inorganic soluble fiberboard exhibits excellent moisture resistance and strength.

[0005] The above-mentioned inorganic soluble fiberboard is produced by grafting unsaturated carbon-carbon bonds onto inorganic soluble fibers and silica sol, followed by cross-linking and polymerization with acrylamide monomers. This produces a uniform and dense inorganic soluble fiberboard, which reduces moisture diffusion into the fiberboard and exhibits good moisture resistance. However, due to the use of acrylamide monomers, the amide groups in which these monomers have a certain degree of hydrophilicity, and thus their moisture resistance needs to be further improved.

[0006] Therefore, it is necessary to provide a soluble fiber inorganic ceramic board that is moisture-resistant and has high strength. Summary of the Invention

[0007] The present application provides a soluble fiber inorganic ceramic board and a preparation method thereof. The soluble fiber inorganic ceramic board has good moisture resistance and strength.

[0008] In a first aspect, the present application provides a method for preparing a soluble fiber inorganic ceramic board, comprising the following steps:

[0009] S10: coating the soluble ceramic fiber with polysiloxane to obtain a modified soluble ceramic fiber; wherein the polysiloxane contains an amino group;

[0010] S20: dispersing the modified soluble ceramic fiber in water to obtain a first mixed solution;

[0011] S30: adding an epoxy silane coupling agent to the silica sol binder to graft epoxy groups onto the surface of the silica in the silica sol binder to obtain a second mixed solution;

[0012] S40: mixing the first mixed liquid and the second mixed liquid to obtain a slurry, wet vacuum forming the slurry, and drying it to obtain a soluble fiber inorganic ceramic plate.

[0013] According to the present application, the moisture resistance of the soluble ceramic fiber can be improved by modifying the soluble ceramic fiber to be hydrophobic and coating its surface with polysiloxane. The polysiloxane contains amino groups, which can promote the coagulation and precipitation of the modified soluble ceramic fiber and the silica colloidal particles in the silica sol binder, and undergo cross-linking reaction with the epoxy groups on the surface of the silica colloidal particles during the subsequent drying process. While avoiding the addition of a hydrophilic organic binder, the various components in the soluble fiber inorganic ceramic board are tightly combined, thereby effectively reducing the intrusion of moisture and improving the strength. The resulting soluble fiber inorganic ceramic board has good moisture resistance and strength.

[0014] In some embodiments, the soluble ceramic fiber is an inorganic alkaline earth silicate fiber, and the length of the soluble ceramic fiber is 0.1 to 10 mm.

[0015] In some embodiments, step S10 includes:

[0016] S11: adding the soluble ceramic fiber to a nitric acid aqueous solution for activation treatment to obtain activated soluble ceramic fiber;

[0017] S12: dissolving and dispersing the activated soluble ceramic fiber, silane coupling agent and catalyst in ethanol for polycondensation reaction, so that the surface of the soluble ceramic fiber is coated with polysiloxane to obtain modified soluble ceramic fiber; wherein the silane coupling agent includes a trifunctional aminosilane coupling agent.

[0018] In some embodiments, the S11 comprises: dispersing 10 parts by mass of soluble ceramic fibers in 50 to 500 parts by mass of a 2 wt% to 6 wt% nitric acid aqueous solution, activating the fibers at 25 to 40° C. for 10 to 30 minutes, and filtering and drying the fibers to obtain the activated soluble ceramic fibers.

[0019] In some embodiments, S12 includes: dissolving and dispersing 10 parts by mass of activated soluble ceramic fiber, 10 to 30 parts by mass of silane coupling agent and 0.1 to 1 part by mass of catalyst in 300 to 700 parts by mass of ethanol, carrying out polycondensation reaction at 70 to 90° C. for 18 to 30 hours, filtering and drying to obtain modified soluble ceramic fiber.

[0020] In some embodiments, in step S12, the silane coupling agent further includes a trifunctional fluorine-containing silane coupling agent, the polysiloxane further contains fluorine atoms, and the mass ratio of the trifunctional aminosilane coupling agent to the trifunctional fluorine-containing silane coupling agent is 1:0.1-0.3.

[0021] In some embodiments, step S20 specifically includes: dispersing 10 parts by mass of the modified soluble ceramic fiber in 50 to 200 parts by mass of water to obtain a first mixed solution.

[0022] In some embodiments, step S30 specifically includes: adding 0.2 to 1 parts by mass of epoxy silane coupling agent to 1 to 5 parts by mass of silica sol binder with a solid content of 20 wt% to 40 wt%, stirring and reacting at 30 to 60° C. for 1 to 4 hours to obtain a second mixed solution.

[0023] In some embodiments, in step S40, the wet vacuum forming includes: using a vacuum degree of 0.03-0.06 MPa for filtration, and using a roller to press with a roller pressure of 0.05-0.1 MPa; the drying conditions include: drying at 100-150° C. for 5-12 hours.

[0024] In a second aspect, the present application provides a soluble fiber inorganic ceramic plate prepared according to the method described in any embodiment of the first aspect. DETAILED DESCRIPTION

[0025] The various embodiments or implementation schemes in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments.

[0026] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0028] In order to further improve the moisture resistance and strength of soluble fiber inorganic ceramic boards, the present application provides a soluble fiber inorganic ceramic board and a preparation method thereof. The inventors perform hydrophobic modification on the surface of the soluble fiber inorganic ceramic board, and at the same time, the coating layer contains amino groups, thereby avoiding the use of hydrophilic organic binders, and by grafting epoxy groups on the surface of silica in the silica sol binder, the bonding force between the modified soluble ceramic fiber and the silica sol binder interface is enhanced through the cross-linking reaction between the epoxy groups and the amino groups. The soluble fiber inorganic ceramic board thus obtained has good moisture resistance and strength. The specific implementation methods of the present application are described in detail below.

[0029] In a first aspect, the present application provides a method for preparing a soluble fiber inorganic ceramic board, comprising the following steps:

[0030] S10: coating the soluble ceramic fiber with polysiloxane to obtain a modified soluble ceramic fiber; wherein the polysiloxane contains an amino group;

[0031] S20: dispersing the modified soluble ceramic fiber in water to obtain a first mixed solution;

[0032] S30: adding an epoxy silane coupling agent to the silica sol binder to graft epoxy groups onto the surface of the silica in the silica sol binder to obtain a second mixed solution;

[0033] S40: mixing the first mixed liquid and the second mixed liquid to obtain a slurry, wet vacuum forming the slurry, and drying it to obtain a soluble fiber inorganic ceramic plate.

[0034] According to the present application, the moisture resistance of the soluble ceramic fiber can be improved by modifying the soluble ceramic fiber to be hydrophobic and coating its surface with polysiloxane. The polysiloxane contains amino groups, which can promote the coagulation and precipitation of the modified soluble ceramic fiber and the silica colloidal particles in the silica sol binder, and undergo cross-linking reaction with the epoxy groups on the surface of the silica colloidal particles during the subsequent drying process. While avoiding the addition of a hydrophilic organic binder, the various components in the soluble fiber inorganic ceramic board are tightly combined, thereby effectively reducing the intrusion of moisture and improving the strength. The resulting soluble fiber inorganic ceramic board has good moisture resistance and strength.

[0035] Specifically, in step S10, in order to reduce the influence of moisture on the soluble ceramic fiber and improve the moisture resistance of the soluble ceramic fiber, the present application coats the surface of the soluble ceramic fiber with polysiloxane. Polysiloxane has good hydrophobicity and can effectively reduce the infiltration of moisture to protect the soluble ceramic fiber. In addition, since the modified soluble ceramic fiber obtained by polysiloxane coating will affect its bonding performance with the silica sol binder, the polysiloxane contains amino groups. On the one hand, the positive charge carried by the amino group can be flocculated and precipitated with the silica silica particles in the silica sol through electrostatic action. On the other hand, the amino group can undergo a cross-linking reaction with the epoxy group grafted on the surface of the silica silica particles in the silica sol, thereby improving the interfacial bonding force between the modified soluble fiber and the silica sol binder. The cross-linking structure can effectively reduce the penetration of moisture into the interior of the ceramic board, while improving the strength of the soluble fiber inorganic ceramic board.

[0036] In step S30, the silica colloidal particles in the silica sol binder are modified by using an epoxy silane coupling agent, and epoxy groups are grafted on their surface. The epoxy groups have good reactivity with the amino groups on the surface of the modified soluble ceramic fibers. The epoxy groups can undergo a cross-linking reaction with the amino groups to tightly bond the modified soluble ceramic fibers to the silica sol binder, thereby overcoming the effect of the hydrophobic coating on the bonding performance of the soluble ceramic fibers and the silica sol binder. It can be understood that the polysiloxane coated on the surface of the soluble ceramic fibers is a flexible material, and the etheramine bond obtained by the reaction of the epoxy groups and the amino groups is a flexible chain segment. The two work together to effectively disperse the stress inside the soluble fiber inorganic ceramic board, thereby improving the strength of the soluble fiber inorganic ceramic board.

[0037] In step S40, the first mixed liquid and the second mixed liquid are mixed to obtain a slurry. The modified soluble ceramic fiber and the epoxy-grafted silica sol binder in the slurry are flocculated and settled by electrostatic action, and are wet-vacuum-formed, which is beneficial to increasing the density of the wet blank after forming, thereby increasing the density of the soluble fiber inorganic ceramic board, and enabling the soluble fiber inorganic ceramic board to have good moisture resistance and strength. In the subsequent drying process, the amino groups on the surface of the modified soluble ceramic fiber and the epoxy groups on the surface of the silica in the silica sol undergo a cross-linking reaction, thereby increasing the interfacial bonding force between the modified soluble ceramic fiber and the silica sol binder, thereby improving the moisture resistance and strength of the soluble fiber inorganic ceramic board.

[0038] In some embodiments, the soluble ceramic fiber is an inorganic alkaline earth silicate fiber, and the length of the soluble ceramic fiber is 0.1 to 10 mm.

[0039] In some of the above embodiments, the soluble ceramic fiber is an inorganic alkaline earth silicate fiber with SiO2, MgO, and CaO as the main components, which has strong in vitro solubility. The use of the above fibers can make the soluble ceramic fiber have better biosafety. As an example, the soluble ceramic fiber used in this application is purchased from Suzhou Gaowei Thermal Energy Technology Co., Ltd. Soluble fiber cotton.

[0040] In some embodiments, step S10 includes:

[0041] S11: adding the soluble ceramic fiber to a nitric acid aqueous solution for activation treatment to obtain activated soluble ceramic fiber;

[0042] S12: dissolving and dispersing the activated soluble ceramic fiber, the silane coupling agent and the catalyst in ethanol for polycondensation reaction, so that the surface of the soluble ceramic fiber is coated with polysiloxane to obtain a modified soluble ceramic fiber; wherein the silane coupling agent includes a trifunctional aminosilane coupling agent.

[0043] In some of the above embodiments, a method for coating soluble ceramic fibers with polysiloxane is specifically defined. By activating the soluble ceramic fibers in an aqueous nitric acid solution, impurities on the surface of the soluble fibers can be removed and the hydroxyl groups on the surface thereof can be activated, making it easier for the silane coupling agent to polymerize and coat the surface thereof to form polysiloxane. The silane coupling agent includes a trifunctional aminosilane coupling agent. The trifunctional aminosilane coupling agent has better reactivity, increases the cross-linking density of the polysiloxane, thereby improving the protection of the soluble ceramic fibers and further improving the moisture resistance of the soluble fiber inorganic ceramic board. At the same time, the surface of the polysiloxane obtained by polymerization of the aminosilane coupling agent contains amino groups, providing reaction sites with epoxy groups.

[0044] It is understood that the trifunctional aminosilane coupling agent has a well-known meaning in the art, wherein the trifunctionality refers to the aminosilane coupling agent including three hydrolyzable siloxy groups, and the aminosilane coupling agent refers to a silane coupling agent including an amino group; by way of example, the trifunctional aminosilane coupling agent may be 3-aminopropyltriethoxysilane.

[0045] In some embodiments, S11 includes: dispersing 10 parts by mass of soluble ceramic fibers in 50 to 500 parts by mass of a 2 wt% to 6 wt% nitric acid aqueous solution, activating the fibers at 25 to 40° C. for 10 to 30 minutes, and filtering and drying the fibers to obtain activated soluble ceramic fibers.

[0046] In the above embodiment, under the above conditions, impurities on the surface of the soluble ceramic fiber can be effectively removed and the activity of the hydroxyl groups on the surface of the soluble ceramic fiber can be increased, promoting the polymerization and coating of the silane coupling agent on its surface, which is beneficial to obtaining modified soluble ceramic fibers with good hydrophobicity and improving the moisture resistance of the soluble fiber inorganic ceramic board.

[0047] In some embodiments, S12 includes: dissolving and dispersing 10 parts by mass of activated soluble ceramic fiber, 10 to 30 parts by mass of silane coupling agent and 0.1 to 1 part by mass of catalyst in 300 to 700 parts by mass of ethanol, carrying out a condensation reaction at 70 to 90° C. for 18 to 30 hours, filtering and drying to obtain modified soluble ceramic fiber.

[0048] In the above embodiment, under the above conditions, the surface of the soluble ceramic fiber can be completely coated with polysiloxane to obtain a well-modified soluble ceramic fiber, thereby improving the moisture resistance of the soluble fiber inorganic ceramic board.

[0049] It is understood that the catalyst can be selected from catalysts known in the art that can catalyze the polymerization of silane coupling agents. For example, the catalyst can be dibutyltin dilaurate.

[0050] In some embodiments, in step S12, the silane coupling agent further includes a trifunctional fluorine-containing silane coupling agent, the polysiloxane further includes fluorine atoms, and the mass ratio of the trifunctional aminosilane coupling agent to the trifunctional fluorine-containing silane coupling agent is 1:0.1-0.3.

[0051] In some of the above embodiments, the silane coupling agent also includes a trifunctional fluorinated silane coupling agent. In this case, the polysiloxane on the surface of the modified soluble ceramic fiber also includes fluorine atoms, and the mass ratio of the aminosilane coupling agent with a functional group and the trifunctional fluorinated silane coupling agent in the silane coupling agent is controlled within the above range. On the one hand, the amino groups on the surface of the modified soluble ceramic fiber flocculate and precipitate with the silica in the silica sol through electrostatic action. However, as the drying proceeds, the electrostatic action weakens, which will cause the silica in the silica sol binder to float, resulting in the formation of inorganic particles on the soluble fiber. The uneven distribution of silica in the ceramic board affects its moisture resistance and strength. The strong interaction between the fluorine atoms on the surface of the soluble ceramic fiber and the silica silica particles can limit the floating of the silica silica particles during the drying process when the electrostatic effect weakens, making the distribution of the silica silica particles more uniform, further improving the moisture resistance and strength of the soluble fiber inorganic ceramic board; on the other hand, the fluorine atoms on the surface of polysiloxane can reduce the surface energy of the modified soluble ceramic fiber, further reducing the penetration of moisture into the fiber, thereby further improving the moisture resistance of the soluble fiber inorganic ceramic board.

[0052] It is understood that the trifunctional fluorinated silane coupling agent has a well-known meaning in the art, and the trifunctionality means that the fluorinated silane coupling agent includes three siloxy groups that can be hydrolyzed, and the fluorinated silane coupling agent refers to a silane coupling agent including fluorine atoms; as an example, the trifunctional fluorinated silane coupling agent can be (3,3,3,-trifluoropropyl)trimethoxysilane.

[0053] In some embodiments, step S20 specifically includes: dispersing 10 parts by mass of the modified soluble ceramic fiber in 50 to 200 parts by mass of water to obtain a first mixed solution.

[0054] In some embodiments, step S30 specifically includes adding 0.2 to 1 parts by weight of an epoxy silane coupling agent to 1 to 5 parts by weight of a silica sol binder having a solid content of 20 to 40 wt%, stirring the mixture at 30 to 60°C for 1 to 4 hours to obtain a second mixed solution. Based on the above embodiments, the conditions for modifying the silica sol binder with the epoxy silane coupling agent are specifically defined, under which epoxy groups can be grafted onto the silica particles in the silica sol binder. It is understood that the silica sol binder is a silica sol dispersed in water. By way of example, the silica sol binder used in this application is a silica sol with a solid content of 30 wt% and a silica particle size of 10 to 15 nm. The term "epoxy silane coupling agent" has a well-known meaning in the art and is a silane coupling agent containing epoxy groups. By way of example, the epoxy silane coupling agent can be γ-glycidoxypropyltrimethoxysilane.

[0055] In some embodiments, in step S40, wet vacuum forming includes: filtration using a vacuum degree of 0.03 to 0.06 MPa, and rolling using a pressure roller at a pressure of 0.05 to 0.1 MPa; and drying conditions include: drying at 100 to 150°C for 5 to 12 hours. Based on the above embodiment, vacuum filtration and rolling under the above conditions can further increase the density of the ceramic fiber board. Drying under the above conditions facilitates crosslinking between amino groups on the surface of the modified soluble ceramic fibers and epoxy groups on the surface of the silica colloidal particles in the silica sol binder, thereby further improving the heat resistance and strength of the unfired ceramic fiber board.

[0056] In a second aspect, the present application provides a soluble fiber inorganic ceramic plate prepared according to the method described in any embodiment of the first aspect.

[0057] According to the present application, since the soluble fiber inorganic ceramic plate is prepared according to the method of any embodiment of the first aspect, it has the beneficial effects of the first aspect.

[0058] Below, the embodiment of the present application is described. The embodiment described below is exemplary and is only used to explain the present application, and is not to be construed as limiting the present application. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially.

[0059] Soluble ceramic fiber: The raw material is purchased from Suzhou Gaowei Thermal Energy Technology Co., Ltd. The soluble fiber cotton is dispersed in water and chopped using a ceramic fiber chopper, and sieved and washed using a filter with a mesh size of 5 mm to obtain soluble ceramic fiber for later use.

[0060] Silica sol was purchased from Shandong Better New Materials Co., Ltd., model SS3015, particle size 10-15 nm, and silica mass content 30%±1%.

[0061] Example 1

[0062] Preparation of soluble fiber inorganic ceramic board:

[0063] 300 g of soluble ceramic fibers were dispersed in 5000 g of a 5 wt% nitric acid aqueous solution, activated at 35° C. for 15 min, and filtered and dried to obtain activated soluble ceramic fibers;

[0064] Activated soluble ceramic fiber, 500 g of 3-aminopropyltriethoxysilane, 100 g of (3,3,3,-trifluoropropyl)trimethoxysilane and 10 g of dibutyltin dilaurate were dissolved and dispersed in 12 kg of ethanol, stirred and reacted at 85 ° C for 24 h, and filtered and dried to obtain modified soluble ceramic fiber;

[0065] Dispersing the modified soluble ceramic fiber in 3000 g of water to obtain a first mixed solution;

[0066] 18 g of γ-glycidyloxypropyltrimethoxysilane was added to 90 g of 30 wt % silica sol binder, and the mixture was stirred and reacted at 50° C. for 2 h to obtain a second mixed solution.

[0067] The first mixed liquid and the second mixed liquid were mixed to obtain a slurry, which was filtered using a vacuum degree of 0.05 MPa and rolled using a roller with a rolling pressure of 0.05 MPa to obtain a wet blank, which was then dried at 115°C for 8 hours to obtain a soluble fiber inorganic ceramic board.

[0068] Example 2

[0069] Preparation of soluble fiber inorganic ceramic board:

[0070] 300 g of soluble ceramic fibers were dispersed in 5000 g of a 5 wt% nitric acid aqueous solution, activated at 35° C. for 15 min, and filtered and dried to obtain activated soluble ceramic fibers;

[0071] The activated soluble ceramic fiber, 600 g of 3-aminopropyltriethoxysilane and 10 g of dibutyltin dilaurate were dissolved and dispersed in 12 kg of ethanol, stirred and reacted at 85° C. for 24 h, and filtered and dried to obtain the modified soluble ceramic fiber;

[0072] Dispersing the modified soluble ceramic fiber in 3000 g of water to obtain a first mixed solution;

[0073] 18 g of γ-glycidyloxypropyltrimethoxysilane was added to 90 g of 30 wt % silica sol binder, and the mixture was stirred and reacted at 50° C. for 2 h to obtain a second mixed solution.

[0074] The first mixed liquid and the second mixed liquid were mixed to obtain a slurry, which was filtered using a vacuum degree of 0.05 MPa and rolled using a roller with a rolling pressure of 0.05 MPa to obtain a wet blank, which was then dried at 115°C for 8 hours to obtain a soluble fiber inorganic ceramic board.

[0075] Example 3

[0076] Preparation of soluble fiber inorganic ceramic board:

[0077] 300 g of soluble ceramic fibers were dispersed in 5000 g of a 5 wt% nitric acid aqueous solution, activated at 35° C. for 15 min, and filtered and dried to obtain activated soluble ceramic fibers;

[0078] Activated soluble ceramic fiber, 300 g of 3-aminopropyltriethoxysilane, 300 g of (3,3,3,-trifluoropropyl)trimethoxysilane and 10 g of dibutyltin dilaurate were dissolved and dispersed in 12 kg of ethanol, stirred and reacted at 85 ° C for 24 h, and filtered and dried to obtain modified soluble ceramic fiber;

[0079] Dispersing the modified soluble ceramic fiber in 3000 g of water to obtain a first mixed solution;

[0080] 18 g of γ-glycidyloxypropyltrimethoxysilane was added to 90 g of 30 wt % silica sol binder, and the mixture was stirred and reacted at 50° C. for 2 h to obtain a second mixed solution.

[0081] The first mixed liquid and the second mixed liquid were mixed to obtain a slurry, which was filtered using a vacuum degree of 0.05 MPa and rolled using a roller with a rolling pressure of 0.05 MPa to obtain a wet blank, which was then dried at 115°C for 8 hours to obtain a soluble fiber inorganic ceramic board.

[0082] Comparative Example 1

[0083] Preparation of soluble fiber inorganic ceramic board:

[0084] 300 g of soluble ceramic fiber was dispersed in 3000 g of water, and after uniform dispersion, 90 g of 30 wt% silica sol binder was added to obtain a mixed solution; 20 g of polyacrylamide was then added, and flocculation and precipitation were performed to obtain a slurry.

[0085] The product was filtered using a vacuum degree of 0.05 MPa and rolled using a roller with a rolling pressure of 0.05 MPa to obtain a wet blank, which was then dried at 115° C. for 8 h to obtain a soluble fiber inorganic ceramic plate.

[0086] Comparative Example 2

[0087] Preparation of soluble fiber inorganic ceramic board:

[0088] 300 g of soluble ceramic fibers were dispersed in 5000 g of a 5 wt% nitric acid aqueous solution, activated at 35° C. for 15 min, and filtered and dried to obtain activated soluble ceramic fibers;

[0089] The activated soluble ceramic fiber, 600 g of 3-aminopropyltriethoxysilane and 10 g of dibutyltin dilaurate were dissolved and dispersed in 12 kg of ethanol, stirred and reacted at 85° C. for 24 h, and filtered and dried to obtain the modified soluble ceramic fiber;

[0090] Dispersing the modified soluble ceramic fiber in 3000 g of water to obtain a first mixed solution;

[0091] 90 g of 30 wt% silica sol binder was added to the first mixed liquid to obtain a mixed liquid; 20 g of polyacrylamide was then added to obtain a slurry by flocculation and precipitation, which was filtered using a vacuum degree of 0.05 MPa and rolled using a roller with a rolling pressure of 0.05 MPa to obtain a wet blank, which was then dried at 115°C for 8 hours to obtain a soluble fiber inorganic ceramic plate.

[0092] The soluble fiber inorganic ceramic boards obtained in Examples 1-3 and Comparative Examples 1 and 2 were tested for flexural strength according to GB / T3001-2017. The boards were then placed in an insulated box at 80°C and 100% relative humidity for 72 hours, removed, cooled to room temperature, and then tested for flexural strength. The difference in strength before and after insulated conditions was calculated, as shown in Table 1.

[0093] Table 1

[0094]

[0095] According to Table 1, the moisture resistance and strength of the soluble fiber inorganic ceramic boards obtained in each example of the present application are superior to those of the comparative example, indicating that the soluble fiber inorganic ceramic boards obtained by the method of the present application have good moisture resistance and strength. It should be noted that in order to verify the moisture resistance of the soluble fiber inorganic ceramic boards of the present application, an accelerated moisture absorption simulation was conducted in a high temperature and high humidity oven, and the strength difference before and after insulation was calculated to evaluate the moisture resistance of the soluble fiber inorganic ceramic boards. The soluble fiber inorganic ceramic board obtained in Comparative Example 1 has the worst moisture resistance, which may be due to its strong hygroscopicity. Under the action of moisture, the interfacial bonding force between the soluble ceramic fiber and the silica sol binder will be reduced. At the same time, moisture will also reduce the strength of the soluble ceramic fiber itself, resulting in poor moisture resistance; the soluble fiber inorganic ceramic board in Comparative Example 2 has the worst strength before insulation, which may be due to the poor interfacial bonding between the hydrophobically modified soluble ceramic fiber and the silica sol binder, resulting in loose bonding between the components, low strength, and easier penetration of moisture into the board, resulting in poor moisture resistance; however, its moisture resistance is better than that of Comparative Example 1, which may be because the coating has less effect on the soluble ceramic fiber, and the moisture resistance is improved relative to Comparative Example 1.

[0096] According to Examples 1 to 3, the soluble fiber inorganic ceramic board obtained in Example 1 has the highest moisture resistance and strength. The reason may be that: in Example 2, the polysiloxane coated on the surface of the soluble ceramic fiber contains only amino groups, which may cause uneven distribution of the silica sol binder during the drying process, resulting in its strength and moisture resistance being inferior to those of Example 1; although the polysiloxane coated on the surface of the soluble ceramic fiber in Example 3 contains both amino groups and fluorine atoms, the amino group content is relatively low, and its cross-linking density is lower than that of Examples 1 and 2, resulting in its strength being lower than that of Examples 1 and 2, but more fluorine atoms are beneficial to reducing the penetration of moisture into the interior of the ceramic board and the soluble ceramic fiber, so its moisture resistance is better than that of Example 2; in Example 1, by controlling the appropriate ratio of amino groups and fluorine atoms on the polysiloxane coated on the surface of the soluble ceramic fiber, the uniform distribution of the silica sol binder can be promoted and the penetration of moisture can be reduced, thereby having good strength and moisture resistance.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application 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 make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a soluble fiber inorganic ceramic board, characterized in that: The following steps are involved: S10: coating the soluble ceramic fiber with polysiloxane to obtain modified soluble ceramic fiber; wherein the polysiloxane contains amino groups; S20: dispersing the modified soluble ceramic fiber in water to obtain a first mixed solution; S30: adding an epoxy silane coupling agent to the silica sol binder to graft epoxy groups onto the surface of the silica in the silica sol binder to obtain a second mixed solution; S40: mixing the first mixed liquid and the second mixed liquid to obtain a slurry, wet vacuum forming the slurry, and drying it to obtain a soluble fiber inorganic ceramic plate.

2. The method according to claim 1, characterized in that The soluble ceramic fiber is an inorganic alkaline earth silicate fiber, and the length of the soluble ceramic fiber is 0.1 to 10 mm.

3. The method according to claim 1, characterized in that The step S10 includes: S11: adding the soluble ceramic fiber to a nitric acid aqueous solution for activation treatment to obtain activated soluble ceramic fiber; S12: dissolving and dispersing the activated soluble ceramic fiber, the silane coupling agent, and the catalyst in ethanol to carry out a polycondensation reaction, so that the surface of the soluble ceramic fiber is coated with polysiloxane to obtain a modified soluble ceramic fiber; Wherein, the silane coupling agent includes a trifunctional aminosilane coupling agent.

4. The method according to claim 3, characterized in that The S11 includes: 10 parts by mass of soluble ceramic fibers are dispersed in 50 to 500 parts by mass of a 2 to 6 wt % nitric acid aqueous solution, activated at 25 to 40° C. for 10 to 30 minutes, and filtered and dried to obtain activated soluble ceramic fibers.

5. The method according to claim 3, characterized in that The S12 includes: 10 parts by mass of activated soluble ceramic fiber, 10 to 30 parts by mass of silane coupling agent and 0.1 to 1 part by mass of catalyst are dissolved and dispersed in 300 to 700 parts by mass of ethanol, subjected to polycondensation reaction at 70 to 90° C. for 18 to 30 hours, and filtered and dried to obtain modified soluble ceramic fiber.

6. The method according to any one of claims 3 to 5, characterized in that In step S12, the silane coupling agent further includes a trifunctional fluorine-containing silane coupling agent, the polysiloxane further contains fluorine atoms, and the mass ratio of the trifunctional aminosilane coupling agent to the trifunctional fluorine-containing silane coupling agent is 1:0.1-0.

3.

7. The method according to claim 1, characterized in that The step S20 specifically includes: 10 parts by mass of modified soluble ceramic fibers are dispersed in 50 to 200 parts by mass of water to obtain a first mixed solution.

8. The method according to claim 7, characterized in that The step S30 specifically includes: 0.2 to 1 parts by mass of epoxy silane coupling agent are added to 1 to 5 parts by mass of silica sol binder with a solid content of 20 wt% to 40 wt%, and the mixture is stirred and reacted at 30 to 60°C for 1 to 4 hours to obtain a second mixed solution.

9. The method according to claim 1, characterized in that In the step S40, The wet vacuum forming comprises: using a vacuum degree of 0.03 to 0.06 MPa for filtration, and using a roller to press at a roller pressure of 0.05 to 0.1 MPa; The drying conditions include: drying at 100-150° C. for 5-12 hours.

10. A soluble fiber inorganic ceramic board, characterized in that: Prepared according to the method according to any one of claims 1 to 9.

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