Rock wool waterproof board based on silicon carbide and preparation method thereof

Abstract

The invention discloses a rock wool waterproof board based on silicon carbide and a preparation method thereof, and belongs to the technical field of rock wool boards. Comprising the following steps: step 1, uniformly mixing basalt, dolomite, coke, slag and silicon carbide whiskers, heating and melting, centrifuging at a rotating speed, and stretching and guiding to obtain rock wool fibers; 2, rock wool fibers are settled through negative pressure suction to form a primary cotton belt, a composite binder is sprayed to the primary cotton belt, then the primary cotton belt is fed into a pendulum bob machine to be folded, and a primary rock wool layer is obtained; 3, the primary rock wool layer is pre-pressed, heated and cured, and then the rock wool waterproof board is obtained. By introducing cerium ion modified silicon dioxide, the network crosslinking and hydrophobicity of the binder are enhanced, and the mechanical strength and lasting waterproof performance of the rock wool board are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of rock wool board technology, specifically, it relates to silicon carbide-based rock wool waterproof board and its preparation method. Background Technology

[0002] Rock wool boards, a Class A non-combustible material widely used in building insulation, are favored for their excellent fire resistance, heat insulation, and sound absorption properties. However, traditional rock wool boards are mainly made from mineral raw materials such as basalt, which are melted at high temperatures, centrifuged into fibers, and then cured with organic binders such as phenolic resin. These binders are prone to decomposition and aging at high temperatures, leading to decreased board strength and insufficient durability. More importantly, rock wool boards are hydrophilic, and their porous fiber structure easily absorbs and permeates moisture, resulting in a high water absorption rate. When the boards are in a humid environment for a long time, the presence of moisture will significantly reduce their insulation performance and may cause a series of problems such as corrosion of metal anchors and mold growth on walls, seriously affecting the safety and service life of buildings.

[0003] To improve the waterproof performance of rock wool boards, existing technologies typically employ methods such as coating the surface of the molded board with a waterproof coating or adding water-repellent agents (such as organosilicon substances). However, the surface coating is easily worn or damaged during transportation and construction, leading to the failure of its waterproof function. Furthermore, purely physically mixed water-repellent agents suffer from problems such as weak adhesion to rock wool fibers, easy migration, and poor durability, making it difficult to maintain a low water absorption rate stably over a long period. In addition, existing technologies often focus on simply physically blocking moisture, failing to fundamentally enhance the structural stability and hydrophobicity of the adhesive network. Therefore, after being subjected to mechanical stress or thermal cycling, its waterproof capability and mechanical strength are prone to significant degradation.

[0004] Therefore, developing a rock wool board that combines excellent mechanical strength, structural stability, and durable and efficient waterproof performance has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and to provide a silicon carbide-based rock wool waterproof board and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions: The preparation method of silicon carbide-based rock wool waterproof board includes the following steps: Step 1: Mix basalt, dolomite, coke, slag, and silicon carbide whiskers evenly, heat and melt them, and then guide them by centrifugation and stretching to obtain rock wool fibers; Step 2: Rock wool fibers are settled by negative pressure suction to form a primary cotton strip. A composite adhesive is sprayed onto the primary cotton strip, and then it is sent into a pendulum machine for folding to obtain a primary rock wool layer. Step 3: Pre-compress the primary rock wool layer and heat it to cure to obtain the rock wool waterproof board.

[0007] In a more optimized manner, the raw materials for preparing the rock wool fiber include the following components: by weight, 40-60 parts basalt, 15-25 parts dolomite, 5-8 parts coke, 20-30 parts slag, and 5-8 parts silicon carbide whiskers.

[0008] In a more optimized manner, the composite adhesive comprises sodium silicate, potassium methylsilicate, and modified silica in a mass ratio of (50-70):(20-25):(10-15).

[0009] In a more optimized manner, the preparation process of the modified silica is as follows: S1: Under a protective atmosphere, 4'-bromo-2,2':6',2''-terpyridine, p-phenylenediamine, cuprous iodide, o-phenanthroline, potassium carbonate, and dimethyl sulfoxide were mixed and stirred until homogeneous. The temperature was then raised to 100-120℃ and reacted for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, post-processed, and purified to obtain product A. S2: Add product A and cerium nitrate hexahydrate to anhydrous ethanol, raise the temperature to 50-60℃, react for 6-7 hours, filter, wash, and dry to obtain the modifier; S3: Epoxidized silica is dispersed in dimethyl sulfoxide, and modifier and triethylamine are slowly added. After stirring evenly, the temperature is raised to 50-60℃ and the reaction is carried out for 2-3 hours. After the reaction is completed, the silica is filtered, washed, and dried to obtain modified silica.

[0010] In the scheme, firstly, 4'-bromo-2,2':6',2''-terpyridine is condensed with p-phenylenediamine to construct an organic ligand (product A) containing both a terpyridine chelating group and an active amino group; subsequently, the terpyridine group is used in conjunction with cerium ions (Ce... 3+ The strong coordination ability of ) enables product A to react with cerium nitrate hexahydrate to synthesize a metal-organic modifier with cerium as the central ion; finally, the active amino group at the end of the modifier undergoes a ring-opening addition reaction with the epoxy group on the surface of epoxidized silica, and the cerium-terpyridine functional unit is firmly anchored on the silica surface through covalent bonding, thereby obtaining the modified silica.

[0011] The structure of the modified silica is shown below: In a more optimized manner, the preparation principle of product A includes the following components: by weight, 10-12 parts of 4'-bromo-2,2':6',2''-terpyridine, 3-4 parts of p-phenylenediamine, 0.5-0.8 parts of cuprous iodide, 1-1.5 parts of o-phenanthroline, 10-15 parts of potassium carbonate, and 150-180 parts of dimethyl sulfoxide.

[0012] In a more optimized manner, the raw materials for preparing the modifier include the following components: by weight, 10-12 parts of product A, 5-7 parts of cerium nitrate hexahydrate, and 100-120 parts of anhydrous ethanol.

[0013] In a more optimized manner, the raw materials for preparing the modified silica include the following components: by weight, 10-12 parts of epoxidized silica, 100-120 parts of dimethyl sulfoxide, 5-8 parts of modifier, and 1-2 parts of triethylamine.

[0014] The beneficial effects of this invention are: This invention improves the performance of rock wool waterproofing boards in multiple ways by introducing modified silica with a specific structure. Specifically: First, in terms of mechanical strength and durability, cerium ions (Ce) anchored on silicon dioxide... 3+ / Ce 4+ Cerium ions can strongly interact with the silicon-oxygen bonds (Si-O) in sodium silicate, forming a composite structure that remains stable at high temperatures. This greatly enhances the thermal stability and integrity of the binder network, giving the rock wool board higher strength and resistance to deformation under mechanical loads. Simultaneously, the variable valence of cerium ions catalyzes the curing reaction of sodium silicate, shortening drying time and inducing self-healing of microcracks under thermal or UV conditions, thus extending the material's service life.

[0015] Secondly, regarding waterproof and moisture-resistant properties, the introduction of modified silica achieves a synergistic enhancement from physical barrier to chemical hydrophobicity. On one hand, it significantly improves the density of the binder network by strengthening its cross-linking density, thereby effectively blocking the capillary channels and diffusion paths for water penetration. On the other hand, the organic functional units grafted onto the silica surface themselves have certain hydrophobic properties. Working synergistically with potassium methylsilicate in the formulation, they further reduce the surface energy of the material, making it more difficult for water droplets to wet and adhere, thus jointly endowing the rock wool board with excellent and durable waterproof and moisture-resistant properties. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] In the following examples, the epoxidized silica is nano-silica modified with silane coupling agent KH-560.

[0018] Example 1: A method for preparing a silicon carbide-based rock wool waterproof board, comprising the following steps: Step 1: Mix 40 parts basalt, 15 parts dolomite, 5 parts coke, 20 parts slag, and 5 parts silicon carbide whiskers evenly, heat and melt them, and then guide them by centrifugation and stretching to obtain rock wool fibers. Step 2: Rock wool fibers are settled by negative pressure suction to form a primary cotton strip. A composite binder (including sodium silicate, potassium methyl silicate, and modified silica in a mass ratio of 50:20:10) is sprayed onto the primary cotton strip. Then, it is sent into a pendulum machine for folding to obtain the primary rock wool layer. Step 3: Pre-compress the primary rock wool layer and heat it to cure to obtain the rock wool waterproof board; The preparation process of modified silica is as follows: S1: Under a protective atmosphere, 10 parts of 4'-bromo-2,2':6',2''-terpyridine, 3 parts of p-phenylenediamine, 0.5 parts of cuprous iodide, 1 part of o-phenanthroline, 10 parts of potassium carbonate, and 150 parts of dimethyl sulfoxide were mixed and stirred evenly. The temperature was raised to 100℃ and reacted for 24 h. After the reaction was completed, the mixture was cooled to room temperature, post-processed, and purified to obtain product A. S2: Add 10 parts of product A and 5 parts of cerium nitrate hexahydrate to 100 parts of anhydrous ethanol, raise the temperature to 50°C, react for 6 hours, filter, wash, and dry to obtain the modifier. S3: Disperse 10 parts of epoxidized silica into 100 parts of dimethyl sulfoxide, slowly add 5 parts of modifier and 1 part of triethylamine, stir evenly, raise the temperature to 50°C, react for 2 hours, filter, wash, and dry to obtain modified silica.

[0019] Example 2: A method for preparing a silicon carbide-based rock wool waterproof board, comprising the following steps: Step 1: Mix 60 parts basalt, 25 parts dolomite, 8 parts coke, 30 parts slag, and 8 parts silicon carbide whiskers evenly, heat and melt them, and then guide them by centrifugation and stretching to obtain rock wool fibers. Step 2: Rock wool fibers are settled by negative pressure suction to form a primary cotton strip. A composite binder (including sodium silicate, potassium methyl silicate, and modified silica in a mass ratio of 70:25:15) is sprayed onto the primary cotton strip. Then, it is sent into a pendulum machine for folding to obtain the primary rock wool layer. Step 3: Pre-compress the primary rock wool layer and heat it to cure to obtain the rock wool waterproof board; The preparation process of modified silica is as follows: S1: Under a protective atmosphere, 12 parts of 4'-bromo-2,2':6',2''-terpyridine, 4 parts of p-phenylenediamine, 0.8 parts of cuprous iodide, 1.5 parts of o-phenanthroline, 15 parts of potassium carbonate, and 180 parts of dimethyl sulfoxide were mixed and stirred evenly. The temperature was raised to 120°C and the reaction was carried out for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, post-processed, and purified to obtain product A. S2: Add 12 parts of product A and 7 parts of cerium nitrate hexahydrate to 120 parts of anhydrous ethanol, raise the temperature to 60°C, react for 7 hours, filter, wash, and dry to obtain the modifier. S3: Disperse 12 parts of epoxidized silica into 120 parts of dimethyl sulfoxide, slowly add 8 parts of modifier and 2 parts of triethylamine, stir evenly, raise the temperature to 60℃, react for 3 hours, filter, wash and dry to obtain modified silica.

[0020] Example 3: A method for preparing a silicon carbide-based rock wool waterproof board, comprising the following steps: Step 1: Mix 50 parts basalt, 20 parts dolomite, 6.5 parts coke, 25 parts slag, and 6.5 parts silicon carbide whiskers evenly, heat to melt, and then guide the mixture by centrifugation and stretching to obtain rock wool fibers. Step 2: Rock wool fibers are settled by negative pressure suction to form a primary cotton strip. A composite binder (including sodium silicate, potassium methyl silicate, and modified silica in a mass ratio of 60:22.5:12.5) is sprayed onto the primary cotton strip. Then, it is sent into a pendulum machine for folding to obtain the primary rock wool layer. Step 3: Pre-compress the primary rock wool layer and heat it to cure to obtain the rock wool waterproof board; The preparation process of modified silica is as follows: S1: Under a protective atmosphere, 11 parts of 4'-bromo-2,2':6',2''-terpyridine, 3.5 parts of p-phenylenediamine, 0.65 parts of cuprous iodide, 1.25 parts of o-phenanthroline, 12.5 parts of potassium carbonate, and 165 parts of dimethyl sulfoxide were mixed and stirred evenly. The temperature was raised to 110°C and reacted for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, post-processed, and purified to obtain product A. S2: Add 11 parts of product A and 6 parts of cerium nitrate hexahydrate to 110 parts of anhydrous ethanol, raise the temperature to 55°C, and react for 6.5 h. After the reaction is complete, filter, wash, and dry to obtain the modifier. S3: Disperse 11 parts of epoxidized silica into 110 parts of dimethyl sulfoxide, slowly add 6.5 parts of modifier and 1.5 parts of triethylamine, stir evenly, raise the temperature to 55℃, and react for 2.5 h. After the reaction is complete, filter, wash, and dry to obtain modified silica.

[0021] Comparative Example 1: Modification of silica without using a modifier, as detailed below: Step 1: Mix 50 parts basalt, 20 parts dolomite, 6.5 parts coke, 25 parts slag, and 6.5 parts silicon carbide whiskers evenly, heat to melt, and then guide the mixture by centrifugation and stretching to obtain rock wool fibers. Step 2: Rock wool fibers are settled by negative pressure suction to form a primary cotton strip. A composite binder (including sodium silicate, potassium methyl silicate, and epoxidized silica in a mass ratio of 60:22.5:12.5) is sprayed onto the primary cotton strip. Then, it is sent into a pendulum machine for folding to obtain the primary rock wool layer. Step 3: Pre-compress the primary rock wool layer and heat it to cure to obtain the rock wool waterproof board.

[0022] Testing experiment: (1) The tensile strength of the rock wool boards in the examples and comparative examples was tested in accordance with the standard GB / T 25975-2018 "Rock wool products for external thermal insulation of building exterior walls"; (2) The water absorption rate of the rock wool boards in the examples and comparative examples was tested according to standard GB / T 5480; The obtained data is shown in the table below: Conclusion: Based on the present invention and experimental data, the silicon carbide-based rock wool waterproof boards prepared in Examples 1, 2, and 3 exhibit excellent performance in terms of tensile strength and water absorption. The tensile strengths reach 158 kPa, 161 kPa, and 165 kPa, respectively, and the water absorption rates are 0.6%, 0.55%, and 0.5%, respectively, significantly better than the tensile strength of 120 kPa and the water absorption rate of 2.5% in Comparative Example 1. This indicates that the present invention effectively improves the mechanical strength and waterproof performance of the rock wool board by introducing modified silica.

[0023] The main reason for the performance degradation in Comparative Example 1 is that it did not use modified silica, but instead used epoxidized silica directly, resulting in a lack of cerium ions (Ce) in the composite binder network. 3+ / Ce 4+The modified silica enhances the bonding properties of rock wool boards. Specifically, cerium ions in the modified silica can form a stable composite structure with the silicon-oxygen bonds in sodium silicate, improving the thermal stability and crosslinking density of the adhesive, thereby enhancing tensile strength and durability. Simultaneously, the variable valence of cerium ions catalyzes the curing reaction and induces self-healing, reducing microcracks. In terms of waterproofing, the organic functional units on the surface of the modified silica provide hydrophobic properties, synergistically reducing the surface energy of the material with potassium methylsilicate and blocking water penetration pathways. In contrast, the first modified silica lacks this synergistic effect, resulting in insufficient adhesive network density and a significantly increased water absorption rate. Therefore, the introduction of modified silica is a key factor in achieving high performance in rock wool boards.

[0024] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the 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 one or more embodiments or examples.

[0025] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing a silicon carbide-based rock wool waterproof board, characterized in that, Includes the following steps: Step 1: Mix basalt, dolomite, coke, slag, and silicon carbide whiskers evenly, heat and melt them, and then guide them by centrifugation and stretching to obtain rock wool fibers; Step 2: Rock wool fibers are settled by negative pressure suction to form a primary cotton strip. A composite adhesive is sprayed onto the primary cotton strip, and then it is sent into a pendulum machine for folding to obtain a primary rock wool layer. Step 3: Pre-compress the primary rock wool layer and heat it to cure to obtain the rock wool waterproof board.

2. The method for preparing the silicon carbide-based rock wool waterproof board according to claim 1, characterized in that, The raw materials for preparing the rock wool fiber include the following components: by weight, 40-60 parts basalt, 15-25 parts dolomite, 5-8 parts coke, 20-30 parts slag, and 5-8 parts silicon carbide whiskers.

3. The method for preparing the silicon carbide-based rock wool waterproof board according to claim 1, characterized in that, The composite adhesive comprises sodium silicate, potassium methyl silicate, and modified silica in a mass ratio of (50-70):(20-25):(10-15).

4. The method for preparing the silicon carbide-based rock wool waterproof board according to claim 3, characterized in that, The preparation process of the modified silica is as follows: S1: Under a protective atmosphere, 4'-bromo-2,2':6',2''-terpyridine, p-phenylenediamine, cuprous iodide, o-phenanthroline, potassium carbonate, and dimethyl sulfoxide were mixed and stirred until homogeneous. The temperature was then raised to 100-120℃ and reacted for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, post-processed, and purified to obtain product A. S2: Add product A and cerium nitrate hexahydrate to anhydrous ethanol, raise the temperature to 50-60℃, react for 6-7 hours, filter, wash, and dry to obtain the modifier; S3: Epoxidized silica is dispersed in dimethyl sulfoxide, and modifier and triethylamine are slowly added. After stirring evenly, the temperature is raised to 50-60℃ and the reaction is carried out for 2-3 hours. After the reaction is completed, the silica is filtered, washed, and dried to obtain modified silica.

5. The method for preparing the silicon carbide-based rock wool waterproof board according to claim 4, characterized in that, The preparation principle of product A includes the following components: by weight, 10-12 parts of 4'-bromo-2,2':6',2''-terpyridine, 3-4 parts of p-phenylenediamine, 0.5-0.8 parts of cuprous iodide, 1-1.5 parts of o-phenanthroline, 10-15 parts of potassium carbonate, and 150-180 parts of dimethyl sulfoxide.

6. The method for preparing the silicon carbide-based rock wool waterproof board according to claim 4, characterized in that, The raw materials for preparing the modifier include the following components: by weight, 10-12 parts of product A, 5-7 parts of cerium nitrate hexahydrate, and 100-120 parts of anhydrous ethanol.

7. The method for preparing the silicon carbide-based rock wool waterproof board according to claim 4, characterized in that, The raw materials for preparing the modified silica include the following components: by weight, 10-12 parts of epoxidized silica, 100-120 parts of dimethyl sulfoxide, 5-8 parts of modifier, and 1-2 parts of triethylamine.

8. The rock wool waterproof board obtained by the preparation method of silicon carbide-based rock wool waterproof board according to any one of claims 1-7.

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