A graphite rock wool product and preparation method thereof

Abstract

The present invention relates to the field of thermal insulation building materials, and in particular to a graphite rock wool product and a preparation method thereof. The preparation method of the graphite rock wool product comprises: pre-drying the rock wool product, then mixing the graphite dispersion obtained by ultrasonic dispersion with the rock wool product under a pre-vacuum state, pressurizing and performing a pressure impregnation treatment, unloading the pressure and performing a post-vacuum treatment under a post-vacuum state, and obtaining the graphite rock wool product through post-treatment; the solvent of the graphite dispersion is an aqueous solution of a surfactant, and the graphite is natural flake graphite. The present invention produces graphite-modified rock wool products by a pressure impregnation method under a vacuum state with the assistance of ultrasonic dispersion, and can evenly disperse graphite on the surface and inside of the rock wool product. The rock wool product has a uniform color and a better thermal conductivity. The present invention can well reduce the thermal conductivity of the rock wool product and improve the fire resistance and thermal insulation effect of the rock wool product.

Description

Technical Field

[0001] The invention relates to the field of thermal insulation building materials, and in particular to a graphite rock wool product and a preparation method thereof. Background Art

[0002] Rock wool is a commonly used external wall insulation material. It has a wide range of raw materials, a fireproof grade of A and good durability. It can last the same lifespan as the building. However, rock wool has a high thermal conductivity and is heavy. In order to achieve the heat transfer coefficient required for ultra-low energy consumption, its thickness is often very large. There is a greater risk of it falling off after being installed on the wall, so the thermal conductivity of rock wool needs to be reduced.

[0003] Natural flake graphite is added to rock wool products. The thermal radiation effect of its smooth surface can reflect infrared rays, thereby effectively reducing the thermal conductivity of rock wool, thereby reducing the thickness of rock wool. On the one hand, it can reduce the risk of rock wool products falling off the exterior wall. On the other hand, it can reduce the cost of building construction, reduce carbon emissions, and help achieve the dual carbon goals. However, graphite is neither hydrophilic nor oleophilic, and it is easy to agglomerate due to van der Waals forces. Adding it directly to rock wool alone can easily cause uneven dispersion, resulting in uneven color and uneven thermal conductivity of rock wool products. At present, there is a study on graphite-modified rock wool products, that is, adding graphite to the raw materials for the production of rock wool products. The preparation method changes the raw materials and production process of rock wool products, and because graphite is easy to agglomerate and difficult to disperse directly, the color distribution and thermal conductivity of rock wool products prepared by this method are uneven, which can easily cause hidden dangers during use. At present, the field urgently needs to provide a new modified rock wool product that reduces the thermal conductivity of rock wool products and its preparation method and process. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a graphite rock wool product and a preparation method thereof. The present invention proposes a pressure impregnation method, using ultrasound assistance, without changing the raw materials and production process of the rock wool, the produced rock wool product is immersed in a uniformly dispersed graphite dispersion, so that the graphite can be evenly dispersed on the surface and inside of the rock wool, thereby obtaining a graphite rock wool product with uniform thermal conductivity.

[0005] In a first aspect, the preparation method of the graphite rock wool product provided by the present invention comprises: pre-treating the rock wool product by drying, then mixing the graphite dispersion obtained by ultrasonic dispersion with the rock wool product under a pre-vacuum state, pressurizing and performing a pressurized impregnation treatment, depressurizing and performing a post-vacuum treatment under a post-vacuum state, and obtaining the graphite rock wool product through post-treatment; the solvent of the graphite dispersion is an aqueous solution of a surfactant, and the graphite is natural flake graphite.

[0006] The present invention produces graphite-modified rock wool products by a pressure impregnation method under a vacuum state, and can evenly disperse natural flake graphite on the surface and inside of the rock wool products. The rock wool products have uniform color and uniform thermal conductivity. The present invention can better produce graphite rock wool products with uniform color and texture, and improve the fireproof performance and thermal insulation effect of the rock wool products.

[0007] Preferably, in the graphite dispersion, the feeding ratio of graphite is 1-8% of the mass of the rock wool product, the concentration of the aqueous solution of the surfactant is 0.1-10 g / L, and the ratio of the aqueous solution of the surfactant to the rock wool product is 1-6L:500-1500g, preferably 2-3L:1000g.

[0008] More preferably, the surfactant is selected from one or more of sodium taurodeoxycholate, OP-10, sodium dodecylbenzene sulfonate and TW-80, preferably TW-80 or OP-10.

[0009] In the present invention, it is further found through research that the graphite dispersion prepared by using the above-mentioned graphite dispersion under the preferred ratio, especially the graphite feed ratio of 2-5%, and the surfactant TW-80 or OP-10, the concentration of 5-7g / L, and the ratio of the aqueous solution of the surfactant to the rock wool product of 2-3L:1000g, is more conducive to improving the dispersion degree of graphite in water and the stability of the suspension, which is conducive to the color and texture of the low thermal conductivity graphite rock wool product being more uniform, and further improving the fire resistance and thermal insulation effect of the rock wool product.

[0010] The present invention selects an aqueous solution of a surfactant to disperse graphite, which is non-toxic, harmless, environmentally friendly, easy to remove, and does not affect the subsequent use of rock wool. In addition, the present invention finds that when the graphite dispersant with the above specific proportion and composition is used, the graphite can be better dispersed, so that the graphite of the rock wool product is more evenly dispersed, and the fireproof performance and thermal insulation effect of the rock wool product are further improved.

[0011] Further preferably, the preparation of the graphite dispersion comprises mixing graphite with an aqueous solution of a surfactant and then subjecting the mixture to ultrasonic treatment; preferably, the frequency of the ultrasonic treatment is 20 to 80 kHz, preferably 20 to 40 kHz, the power is 80 to 450 W, preferably 80 to 180 W, and the time is 0.5 to 5 h, preferably 1 to 3 h.

[0012] More preferably, the vacuum degree of the pre-vacuum state is 0.06 to 0.09 MPa, preferably 0.07 to 0.09 MPa, and the treatment time of the pre-vacuum state is 1 to 30 min, preferably 10 to 20 min.

[0013] More preferably, the pressurized pressure is 0.1 to 1.5 MPa, preferably 1.2 to 1.5 MPa, and the pressurized immersion treatment time is 10 to 20 min, preferably 15 to 20 min.

[0014] More preferably, the vacuum degree of the post-vacuum state is 0.05 to 0.08 MPa, preferably 0.07 to 0.08 MPa, and the post-vacuum treatment time is 1 to 20 min, preferably 15 to 20 min.

[0015] In the present invention, the graphite is better dispersed in the aqueous solution of the surfactant through the above-mentioned ultrasonic treatment, which can further reduce the surface tension of the graphite in water and achieve the effect of uniform dispersion. At the same time, under the above-mentioned vacuum and treatment conditions, it can be more evenly dispersed on the surface and inside of the rock wool through the pressure impregnation method, further improving the comprehensive performance of the product.

[0016] Preferably, the rock wool product can be prepared by conventional methods in the art, for example, the preparation includes raw material melting, fiber forming, wool collecting, wool folding, extrusion stacking and / or longitudinal folding, curing, and cutting to obtain the rock wool product.

[0017] Preferably, the post-treatment comprises the steps of releasing the vacuum, withdrawing the non-immersed graphite dispersion and drying.

[0018] Further preferably, the method comprises the following steps:

[0019] 1) Pre-treating the rock wool products including drying and pre-vacuum treatment in the impregnation tank;

[0020] 2) mixing graphite with an aqueous solution of a surfactant and subjecting the mixture to ultrasonic treatment to obtain a graphite dispersion;

[0021] 3) Under vacuum condition, the vacuum pump continues to operate, and the graphite dispersion is injected into the impregnation tank and stirred;

[0022] 4) Pressurize, continue the pressure value for the set time to perform the pressurized immersion treatment, release the pressure, and perform the post-vacuum treatment under the post-vacuum state;

[0023] 5) releasing the vacuum, pumping back the un-immersed graphite dispersion by a centrifugal pump, and drying to obtain the graphite rock wool product. The present invention optimizes the preparation process of graphite rock wool and the graphite dispersion, combines specific pre-vacuum treatment, vacuum pressure impregnation and post-vacuum treatment, and optimizes the process parameters to significantly improve the surface and internal color and texture uniformity, thermal conductivity and its uniformity, fire resistance and thermal insulation effect of the graphite rock wool board.

[0024] The preparation method of the modified rock wool product with reduced thermal conductivity of rock wool of the present invention, under the premise of not changing the rock wool production process, adds a pressurized impregnation equipment line, and injects the homogeneous suspension of graphite into the rock wool uniformly by the pressurized impregnation method, so as to obtain the graphite modified rock wool product. Graphite particles can reflect thermal radiation like a mirror, and when graphite is uniformly dispersed inside the rock wool, the thermal radiation of the rock wool can be increased, the thermal conductivity of the rock wool can be reduced, and the heat loss of the house can be reduced. After the rock wool is produced, the present invention is placed in a pressure vessel after a series of pretreatments such as drying, and a certain negative pressure is formed by a vacuum pump to remove the gas in the rock wool cavity; then the graphite dispersion liquid formed by ultrasonic dispersion in the aqueous solution of the surfactant to form a stable suspension state is injected into the impregnation tank, and then a certain pressure is applied to the tank by a pressure device, and the graphite dispersion liquid is pressed into the rock wool, and then a series of steps such as pressure maintenance, pressure relief, and drying are obtained to obtain the graphite modified rock wool product, and the graphite modified rock wool product can further improve the comprehensive effect of the graphite rock wool product.

[0025] In a second aspect, the graphite rock wool product provided by the present invention is prepared by the preparation method of the graphite rock wool product.

[0026] Preferably, the thermal conductivity of the graphite rock wool product is 0.030-0.042 W / m·K; preferably, the graphite rock wool product is a graphite rock wool product with uniform color.

[0027] Further preferably, the thermal conductivity of the graphite rock wool product is 0.030-0.040 W / m·K; the graphite rock wool product is a graphite rock wool product with uniform color; preferably, the surface and interior of the graphite rock wool product board are uniform in color and texture.

[0028] The beneficial effect of the present invention is at least that: the present invention obtains graphite-modified rock wool products by adding pressurized impregnation equipment without changing the rock wool production process. The thermal conductivity of rock wool can be significantly reduced, and the graphite particles in the product can reflect thermal radiation like a mirror. The graphite of the present invention is more evenly dispersed on the surface and inside of the rock wool, which can better increase the thermal radiation of rock wool, reduce the thermal conductivity of rock wool, and reduce the heat loss of the house. The method of the present invention can also overcome the problem that graphite is neither hydrophilic nor oleophilic, and because of the easy agglomeration of van der Waals force, it is easy to cause uneven dispersion when directly added to rock wool, thereby causing the color of rock wool products to be uneven, and the thermal conductivity is uneven at the same time. By ultrasonic treatment, the graphite is dispersed in an aqueous solution of a surfactant, which can reduce the surface tension of graphite in water and achieve the effect of uniform dispersion. Then, it is evenly dispersed on the surface and inside of rock wool by pressurized impregnation, which effectively reduces the thermal conductivity of rock wool, thereby reducing the use thickness of rock wool. On the one hand, it can reduce the risk of rock wool products falling off from the exterior wall, and on the other hand, it can reduce the cost of building construction, reduce carbon emissions, and help achieve the dual carbon goals. The present invention selects an aqueous solution of a surfactant to disperse graphite, which can also be non-toxic, harmless, environmentally friendly, easy to remove and does not affect the subsequent use of rock wool. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below. The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention. If the specific technology or conditions are not specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0030] In the embodiment of the present invention, the rock wool products are selected from the rock wool boards and rock wool strips commonly found on the market. The rock wool products prepared by the present invention include rock wool products, rock wool strips and composite products prepared with rock wool products or rock wool strips as core materials.

[0031] In the following examples of the present invention, unless otherwise specified, the graphite used is natural flake graphite.

[0032] The method for preparing a graphite rock wool product provided in an embodiment of the present invention comprises:

[0033] 1) Pre-treating the rock wool products including drying and pre-vacuum treatment in the impregnation tank;

[0034] 2) mixing graphite with an aqueous solution of a surfactant and subjecting the mixture to ultrasonic treatment to obtain a graphite dispersion;

[0035] 3) In a vacuum state, i.e., the vacuum pump continues to operate, injecting the graphite dispersion into an impregnation tank and stirring;

[0036] 4) Pressurize, continue the pressure value for pressurized infusion treatment, release the pressure, and perform post-vacuum treatment at the post-vacuum degree;

[0037] 5) releasing the vacuum, pumping back the unimmersed graphite dispersion by a centrifugal pump, and drying to obtain the graphite rock wool product.

[0038] Example 1

[0039] The preparation method of the graphite rock wool product provided in this embodiment includes:

[0040] 1. After drying the commercially available rock wool board, put it into the impregnation tank for pre-vacuum treatment with a vacuum degree of 0.08MPa for 10 minutes;

[0041] 2. While the plate is being vacuum treated, 5% of the natural flake graphite by mass of the rock wool board is evenly dispersed in the TW-80 aqueous solution by a 120W, 40kHz ultrasonic cleaning machine. The ultrasonic time is 1h, the concentration of TW-80 is 6g / L, and the ratio of the volume of the TW-80 aqueous solution to the mass of the rock wool board is 2L:1000g;

[0042] 3. The vacuum pump continues to run, and under the above vacuum state, the graphite dispersion is injected into the impregnation tank and stirred;

[0043] 4. Pressurize to 1.5MPa, maintain this pressure value for 20 minutes, then release the pressure and perform post-vacuum treatment with a vacuum degree of 0.08MPa for 20 minutes;

[0044] 5. Release the vacuum, use a centrifugal pump to draw back the unimmersed graphite dispersion, and repeatedly dry the rock wool product to obtain the graphite rock wool product.

[0045] The surface and internal color and texture of the graphite rock wool board prepared in this embodiment are very uniform, and the uniformity is very good. The thermal conductivity and uniformity of the rock wool product are better than those of existing products. The thermal conductivity of the graphite rock wool product is 0.032W / m·K, which significantly improves the fire resistance and thermal insulation effect of the rock wool product, and has the best comprehensive performance.

[0046] Example 2

[0047] 1. After drying the commercially available rock wool board, put it into the impregnation tank for pre-vacuum treatment with a vacuum degree of 0.08MPa for 10 minutes;

[0048] 2. While the plate is being vacuum treated, 5% of the natural flake graphite by mass of the rock wool board is evenly dispersed in an OP-10 aqueous solution by a 120W, 40kHz ultrasonic cleaning machine. The ultrasonic time is 1h, the concentration of OP-10 is 6g / L, and the ratio of the volume of the TW-80 aqueous solution to the mass of the rock wool board is 2L:1000g;

[0049] 3. The vacuum pump continues to run, and under the above vacuum state, the graphite dispersion is injected into the impregnation tank and stirred;

[0050] 4. Pressurize to 1.5MPa, maintain this pressure value for 20 minutes, then release the pressure and perform post-vacuum treatment with a vacuum degree of 0.08MPa for 20 minutes;

[0051] 5. Release the vacuum, use a centrifugal pump to draw back the unimmersed graphite dispersion, and repeatedly dry the rock wool product to obtain the graphite rock wool product.

[0052] The graphite rock wool product board prepared in this embodiment has uniform color on the surface and inside, a thermal conductivity of 0.032 W / m·K, and excellent comprehensive performance.

[0053] Example 3

[0054] 1. After drying the commercially available rock wool board, put it into the impregnation tank for pre-vacuum treatment with a vacuum degree of 0.08MPa for 10 minutes;

[0055] 2. While the plate is being vacuum treated, 10% of the natural flake graphite by mass of the rock wool board is evenly dispersed in the TW-80 aqueous solution by a 120W, 40kHz ultrasonic cleaning machine. The ultrasonic time is 1h, the concentration of TW-80 is 6g / L, and the ratio of the volume of the TW-80 aqueous solution to the mass of the rock wool board is 2L:1000g;

[0056] 3. The vacuum pump continues to run, and under the above vacuum state, the graphite dispersion is injected into the impregnation tank and stirred;

[0057] 4. Pressurize to 1.5MPa, maintain this pressure value for 20 minutes, then release the pressure and perform post-vacuum treatment with a vacuum degree of 0.08MPa for 20 minutes;

[0058] 5. Release the vacuum, use a centrifugal pump to draw back the unimmersed graphite dispersion, and repeatedly dry the rock wool product to obtain the graphite rock wool product.

[0059] The graphite rock wool board prepared in this embodiment has uniform color on the surface and inside, a thermal conductivity of 0.038 W / m·K, and excellent comprehensive performance.

[0060] Example 4

[0061] 1. Dry the commercially available rock wool strips and put them into the impregnation tank for pre-vacuum treatment with a vacuum degree of 0.08MPa for 10min;

[0062] 2. While the plate is being vacuum treated, 5% of the natural flake graphite by mass of the rock wool board is evenly dispersed in the TW-80 aqueous solution by a 120W, 40kHz ultrasonic cleaning machine. The ultrasonic time is 1h, the concentration of TW-80 is 6g / L, and the ratio of the volume of the TW-80 aqueous solution to the mass of the rock wool board is 2L:1000g;

[0063] 3. The vacuum pump continues to run, and under the above vacuum state, the graphite dispersion is injected into the impregnation tank and stirred;

[0064] 4. Pressurize to 1.5MPa, maintain this pressure value for 20 minutes, then release the pressure and perform post-vacuum treatment with a vacuum degree of 0.08MPa for 20 minutes;

[0065] 5. Release the vacuum, use a centrifugal pump to draw back the unimmersed graphite dispersion, and repeatedly dry the rock wool product to obtain the graphite rock wool product.

[0066] The graphite rock wool strip prepared in this embodiment has uniform color on the surface and inside, a thermal conductivity of 0.040 W / m·K, and excellent comprehensive performance.

[0067] Comparative Example 1

[0068] 1. After drying the commercially available rock wool board, put it into the impregnation tank for pre-vacuum treatment with a vacuum degree of 0.08MPa for 10 minutes;

[0069] 2. Directly add 10% graphite into water and stir mechanically. The ratio of the volume of water to the mass of the rock wool board is 2L:1000g;

[0070] 3. The vacuum pump continues to run, and under the above vacuum state, the graphite dispersion is injected into the impregnation tank and stirred;

[0071] 4. Pressurize to 1.5MPa, maintain this pressure value for 20 minutes, then release the pressure and perform post-vacuum treatment with a vacuum degree of 0.08MPa for 20 minutes;

[0072] 5. Release the vacuum, use a centrifugal pump to draw back the unimmersed graphite dispersion, and repeatedly dry the rock wool product to obtain the graphite rock wool product.

[0073] The graphite rock wool board prepared in this comparative example has different shades of color, black and yellow, and the graphite cannot form a uniform and stable dispersion liquid, and all settles at the bottom of the tank, and thus cannot penetrate into the surface and interior of the rock wool board. The effect is worse than that of Example 1.

[0074] Comparative Example 2

[0075] 1. Dry the commercially available rock wool strips and put them into the impregnation tank for pre-vacuum treatment with a vacuum degree of 0.08MPa for 10min;

[0076] 2. While the rock wool strips are being vacuum treated, 12% of the graphite by mass of the rock wool board is evenly dispersed in a TW-80 aqueous solution using a 120W, 40kHz ultrasonic cleaning machine. The ultrasonic time is 1h, the concentration of TW-80 is 6g / L, and the ratio of the volume of the TW-80 aqueous solution to the mass of the rock wool board is 2L:1000g;

[0077] 3. The vacuum pump continues to run, and under the above vacuum state, the graphite dispersion is injected into the impregnation tank and stirred;

[0078] 4. Pressurize to 1.5MPa, maintain this pressure value for 20 minutes, then release the pressure and perform post-vacuum treatment with a vacuum degree of 0.08MPa for 20 minutes;

[0079] 5. Release the vacuum, use a centrifugal pump to draw back the unimmersed graphite dispersion, and repeatedly dry the rock wool product to obtain the graphite rock wool product.

[0080] The graphite rock wool strips prepared in this comparative example have uniform color, but due to excessive addition of graphite, visible graphite particles are stacked on the surface of the rock wool strips, and the thermal conductivity is not optimized, which is 0.045 W / m·K, and the effect is not good.

[0081] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a graphite rock wool product, characterized in that: include: The rock wool product is subjected to a drying pretreatment, and then the graphite dispersion obtained by ultrasonic dispersion is mixed with the rock wool product under a pre-vacuum state, pressurized and subjected to a pressure impregnation treatment, and the pressure is released and subjected to a post-vacuum treatment under a post-vacuum state, and a graphite rock wool product is obtained through post-treatment; the solvent of the graphite dispersion is an aqueous solution of a surfactant, and the graphite is natural flake graphite; In the graphite dispersion, the feeding ratio of graphite is 2-5% of the mass of the rock wool product, the concentration of the aqueous solution of the surfactant is 5-7 g / L, the ratio of the aqueous solution of the surfactant to the rock wool product is 2-3 L: 1000 g, and the surfactant is TW-80 or OP-10; The preparation of the graphite dispersion comprises mixing graphite with an aqueous solution of a surfactant and then performing an ultrasonic treatment; the ultrasonic treatment has a frequency of 20 to 80 kHz, a power of 80 to 450 W, and a time of 0.5 to 5 hours; The vacuum degree of the pre-vacuum state is 0.06-0.09 MPa, and the treatment time of the pre-vacuum state is 1-30 min; the vacuum degree of the post-vacuum state is 0.05-0.08 MPa, and the treatment time of the post-vacuum state is 1-20 min; the pressurized pressure is 0.1-1.5 MPa.

2. The method for preparing graphite rock wool products according to claim 1, characterized in that: The preparation of the graphite dispersion comprises mixing graphite with an aqueous solution of a surfactant and then performing ultrasonic treatment; the ultrasonic treatment has a frequency of 20 to 40 kHz, a power of 80 to 180 W, and a time of 1 to 3 hours.

3. The method for preparing graphite rock wool products according to claim 1, characterized in that: The time of the pressure immersion treatment is 10 to 20 minutes.

4. The method for preparing graphite rock wool products according to claim 1, characterized in that: The post-treatment includes the steps of releasing the vacuum, withdrawing the non-immersed graphite dispersion, and drying.

5. The method for preparing a graphite rock wool product according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) Pre-treat the rock wool products including drying and pre-vacuum treatment in the impregnation tank; 2) mixing graphite with an aqueous solution of a surfactant and subjecting it to ultrasonic treatment to obtain a graphite dispersion; 3) Under vacuum condition, the vacuum pump continues to run, and the graphite dispersion is injected into the impregnation tank and stirred; 4) Pressurize, continue the pressure value for the set time to perform pressurized immersion treatment, release the pressure, and perform post-vacuum treatment under the post-vacuum state; 5) releasing the vacuum, pumping back the unimmersed graphite dispersion by a centrifugal pump, and drying to obtain the graphite rock wool product.

6. A graphite rock wool product, characterized in that: The graphite rock wool product is prepared by the preparation method of the graphite rock wool product according to any one of claims 1 to 5.

7. The graphite rock wool product according to claim 6, characterized in that: The thermal conductivity of the graphite rock wool product is 0.030-0.042 W / m·K; the graphite rock wool product is a graphite rock wool product with uniform color.

8. The graphite rock wool product according to claim 7, characterized in that: The thermal conductivity of the graphite rock wool product is 0.030-0.040 W / m·K; the graphite rock wool product is a graphite rock wool product with uniform color.

9. The graphite rock wool product according to claim 8, characterized in that: The surface and interior of the graphite rock wool product are uniform in color and texture.