A sound-absorbing and conductive composite plate and its preparation method

Abstract

This invention discloses a sound-absorbing and conductive composite board and its preparation method, relating to the field of new materials technology. The invention first fills the voids in basalt particles with polyurethane. After impregnation under vacuum pressure, the filled basalt particles are added to a foam matrix to obtain a foamed material. The foamed material is crushed and dispersed in styrene to obtain a dispersion. Three-dimensional graphene is prepared using chemical vapor deposition. Using the three-dimensional graphene as a substrate, large-size graphene aerogel is prepared by freeze-drying. After heat treatment, the dispersion is injected into the large-size graphene aerogel using a vacuum-assisted infusion method to obtain a sound-absorbing and conductive core material. The sound-absorbing and conductive core material is placed between two layers of polyvinyl chloride foam boards, and the two are bonded together using an adhesive. After heavy pressure shaping, the sound-absorbing and conductive composite board is obtained. The sound-absorbing and conductive composite board prepared by this invention is lightweight and has good mechanical properties while being sound-absorbing and conductive.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, specifically to a sound-absorbing and conductive composite plate and its preparation method. Background Technology

[0002] As people's demands for comfort and functionality in modern buildings increase, the development and research of various building structures and materials have become a hot topic in the industry. To meet the sound absorption requirements of modern buildings, a large number of sound-absorbing materials have emerged and are applied in the construction field. However, most of these sound-absorbing materials are heavy and their sound absorption effect is not very good. Therefore, it is necessary to prepare a composite board with strong sound absorption properties.

[0003] The composite board produced by this invention not only has good sound absorption and light weight, but also has electrical conductivity, thus meeting the dual requirements of sound absorption and electrical conductivity in special locations. Summary of the Invention

[0004] The purpose of this invention is to provide a sound-absorbing and conductive composite plate and its preparation method, so as to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a sound-absorbing and conductive composite plate, characterized in that the process flow for preparing the sound-absorbing and conductive composite plate is as follows:

[0006] Filler, vacuum pressure treatment, mixing, dispersion preparation, three-dimensional graphene preparation, large-size graphene aerogel preparation, heat treatment, filling, finished product.

[0007] Furthermore, a method for preparing a sound-absorbing and conductive composite plate is characterized by comprising the following specific steps:

[0008] (1) After cleaning the basalt, ball milling is performed to obtain basalt particles. The basalt particles are placed in a mold for later use. The polyurethane particles are placed in a three-necked flask equipped with a stirrer, heated at a constant temperature in an oil bath and stirred initially until the polyurethane melts. The stirring speed is adjusted for secondary stirring. The melted polyurethane is then poured into the mold, the mold is sealed, and a vacuum is applied. The vacuum-treated mold is then placed in a constant temperature drying oven for curing to obtain pre-treated particles.

[0009] (2) Place the pretreated particles in a vacuum press and perform vacuum pressure treatment. Set the power of the vacuum press to 100W, the pressure to 2 atmospheres, the time to 10~20min, and the vacuum degree to 2~3Pa.

[0010] (3) Add the pretreated particles after vacuum pressure treatment to the polyacrylate foaming system, add the foaming agent sodium bicarbonate, start stirring, and then cure after stirring. After curing, the foamed material is obtained.

[0011] (4) After ball milling the foaming material, foaming material powder is obtained. The foaming material powder is added to styrene, and the mass ratio of foaming material powder to styrene is controlled to be 3:4~3:5. After being dispersed evenly, a dispersion is obtained.

[0012] (5) Prepare graphene oxide into a graphene dispersion with a concentration of 20 mg / ml, disperse it evenly by ultrasonication, dilute it into a dispersion with a concentration of 10 mg / ml, pour the dispersion into a freeze-drying mold, first set the freeze dryer to the freezing mode, cool it down and freeze it, then set the freeze dryer to the drying mode, perform vacuuming, set the vacuum degree to 1 Pa, then heat the mold, keep it warm for a period of time, and obtain three-dimensional graphene after cooling.

[0013] (6) Add three-dimensional graphene into a tube furnace, introduce a mixture of hydrogen and argon, raise the temperature to 1000℃, keep the reaction at the temperature, and obtain large-size graphene aerogel after cooling.

[0014] (7) After soaking the large-size graphene aerogel in 75% hydrazine hydrate, put it into a desiccator, then seal the desiccator and put it into a forced-air drying oven. The temperature is raised to 90°C for the first time to start the reaction. After the reaction is completed, the temperature of the forced-air drying oven is raised to 200°C and the reaction is kept at a constant temperature. After cooling, the heat-treated large-size graphene aerogel is obtained.

[0015] (8) Mix the dispersion and curing agent vinyltriamine evenly to obtain a curing liquid. Pour the curing liquid into a mold and immerse the heat-treated large-size graphene aerogel into the curing liquid so that the large-size graphene aerogel absorbs the curing liquid to saturation. Perform vacuum drying to obtain a cured block. Place the cured block in a drying oven to continue curing to obtain a sound-absorbing and conductive core material.

[0016] (9) Place the sound-absorbing and conductive core material between two layers of polyvinyl chloride foam board, use phenolic resin as an adhesive to bond the two together, and then press and shape it to obtain a sound-absorbing and conductive composite board.

[0017] Furthermore, in step (1) above, the basalt particles after ball milling have a particle size of 3~5mm, the ball milling time is 5~10min, the oil bath temperature is 230~240℃, the initial stirring speed is 200r / min, the secondary stirring speed is 800r / min, the stirring time is 6~10min, the vacuum degree is set to -0.1MPa, and the temperature is 80℃ and the drying time is 10~12h during constant temperature blower drying.

[0018] Furthermore, in step (3) above, the mass ratio of pretreated particles, polyacrylate and foaming agent sodium bicarbonate is 5:7:0.3~5:7:0.5, the stirring rate is 1000r / min, and the stirring time is 15~20min.

[0019] Furthermore, in step (5) above, the temperature is lowered to -45℃ and the freezing time is 4~5h; the heating rate is controlled at 1℃ / h, the temperature is raised to 30℃, and the holding time is 24h.

[0020] Furthermore, in step (6) above, the volume ratio of hydrogen to argon is 1:9; the heating rate is 10℃ / min; and the holding time is 2~3h.

[0021] Furthermore, in step (7) above, the first heating rate is 1℃ / min, the reaction time is 24h, and the constant temperature reaction time is 30min.

[0022] Furthermore, in step (8) above, the mass ratio of dispersion to curing agent vinyltriamine is 9:1 to 10:1; vacuum is applied to -0.1 MPa, and the drying time is 1 to 2 hours; the temperature in the drying oven is 80°C, and the drying time is 5 to 6 hours.

[0023] Furthermore, the sound-absorbing and conductive composite board prepared by the method comprises the following raw materials in parts by weight: 50-60 parts of sound-absorbing and conductive core material, 100-120 parts of polyvinyl chloride foam board, and 200-300 parts of phenolic resin adhesive; the foam material is prepared by processing basalt, polyurethane, and polyacrylate; the sound-absorbing and conductive core material is prepared by processing foam material, styrene, and three-dimensional graphene.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0025] This invention involves surface-treating basalt, ball-milling it into powder, and filling the voids in the basalt particles with polyurethane to obtain pretreated particles. Using polyacrylate as the foaming matrix, the pretreated particles are vacuum-pressure treated and then added to the foaming system. After curing, a foamed material is obtained. The basalt surface treatment removes large impurities, and the powder is ball-milled. Although basalt is very hard, its numerous pores make the particles brittle. Filling the voids in the basalt particles with polyurethane, due to its energy-absorbing properties and resistance to deformation, allows the polyurethane to participate in compression deformation when the basalt fibers are compressed, absorbing compressive energy and alleviating the pressure load on the basalt particles. This significantly inhibits the overall deformation of the pretreated particles. This process increases the load-bearing capacity of the basalt particles, improves their brittleness, and reduces their porosity, leading to thicker pore walls that make them more resistant to compression and deformation under load. The pre-treated particles also exhibit improved sound absorption. Vacuum pressure treatment forces air out of the particles, causing the polyurethane filling to become uneven, further enhancing sound absorption. Adding the pre-treated particles to the foaming matrix during foaming increases the degree of polyacrylate foaming and saves time. The foaming matrix undergoes self-crosslinking with the polyurethane under the catalysis of an external crosslinking agent, introducing the pre-treated particles into the polyacrylate molecules. This increases both the sound absorption performance of the composite board and the stability of the pre-treated particles within the sound-absorbing matrix.

[0026] Foaming material was ball-milled to obtain foaming material powder, which was then dispersed in styrene to prepare a dispersion. Three-dimensional graphene was prepared using freeze-drying. Large-size graphene aerogels were prepared using the three-dimensional graphene as a substrate. After heat treatment, the dispersion was infused into the large-size graphene aerogels using a vacuum-assisted infusion method to obtain a sound-absorbing and conductive core material. The large-size graphene aerogels prepared by freeze-drying have a low density. The heat treatment step further stabilizes the three-dimensional graphene mesh structure and increases its density. After thermal reduction, graphene exhibits improved electrical conductivity. The dispersion solidifies inside the large-size graphene aerogel after being poured in. Surface tension causes the dispersion to adhere to the graphene, and the nanoscale foaming material powder in the dispersion fills the gaps in the large-size graphene aerogel. This ensures sound absorption while increasing the mechanical properties of the sound-absorbing and conductive core material. Simultaneously, the limiting effect of the dispersion and the large-size graphene aerogel on the foaming material powder increases its dispersibility and stability, enabling the sound-absorbing and conductive composite board to achieve electrical conductivity while absorbing sound. Detailed Implementation

[0027] 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.

[0028] To more clearly illustrate the method provided by the present invention, the following embodiments are provided in detail. The test methods for various indicators of the sound-absorbing and conductive composite board produced in the following embodiments are as follows:

[0029] Sound absorption performance: The sound-absorbing and conductive composite boards of Examples 1, 2 and Comparative Example 2 were subjected to material sound absorption tests. The sound-absorbing and conductive composite board prepared by this invention was placed in a KTV karaoke room for testing. With the door closed, a decibel meter was used to test it from outside the door. The lower the decibel reading, the better the sound absorption effect of the sound-absorbing and conductive composite board.

[0030] Conductivity: Conductivity tests were conducted on the sound-absorbing and conductive composite boards of Examples 1, 2, and Comparative Example 1. The resistivity of the sound-absorbing and conductive composite boards was measured. The higher the resistivity, the worse the conductivity.

[0031] Example 1

[0032] A sound-absorbing and conductive composite board, by weight, mainly comprises: 60 parts sound-absorbing and conductive core material, 120 parts polyvinyl chloride foam board, and 300 parts phenolic resin adhesive; the foam material is obtained by processing basalt, polyurethane, and polyacrylate; the sound-absorbing and conductive core material is obtained by processing foam material, styrene, and three-dimensional graphene.

[0033] A method for preparing a sound-absorbing and conductive composite plate, the method mainly includes the following preparation steps:

[0034] (1) After cleaning the basalt, ball milling was performed. The basalt particles after ball milling had a particle size of 5 mm and a milling time of 10 min. The basalt particles were placed in a mold for later use. The polyurethane particles were placed in a three-necked flask equipped with a stirrer and heated in an oil bath at a constant temperature. Initial stirring was started at an oil bath temperature of 240℃ and an initial stirring speed of 200 r / min until the polyurethane melted. The stirring speed was adjusted and a second stirring was performed at a second stirring speed of 800 r / min for 10 min. The melted polyurethane was then poured into a mold, the mold was sealed, and a vacuum was drawn with a vacuum degree of -0.1 MPa. The vacuumed mold was then placed in a constant temperature drying oven for curing at a temperature of 80℃ for 12 h to obtain pretreated particles.

[0035] (2) Place the pretreated particles in a vacuum press and perform vacuum pressure treatment. Set the power of the vacuum press to 100W, the pressure to 2 atmospheres, the time to 20min, and the vacuum degree to 3Pa.

[0036] (3) Add the pretreated particles after vacuum pressure treatment to the polyacrylate foaming system, add the foaming agent sodium bicarbonate, and the mass ratio of pretreated particles, polyacrylate and foaming agent sodium bicarbonate is 5:7:0.5. Start stirring, the stirring speed is 1000r / min, the stirring time is 20min, and then solidify after stirring. After solidification, the foamed material is obtained.

[0037] (4) After ball milling the foaming material, foaming material powder is obtained. The foaming material powder is added to styrene, and the mass ratio of foaming material powder to styrene is controlled to be 3:5. After being dispersed evenly, a dispersion is obtained.

[0038] (5) Graphene oxide was prepared into a graphene dispersion with a concentration of 20 mg / ml, which was ultrasonically dispersed evenly and diluted to a dispersion with a concentration of 10 mg / ml. The dispersion was poured into a freeze-drying mold. The freeze dryer was first set to freezing mode and cooled to -45℃ for 5 hours. Then the freeze dryer was set to drying mode and vacuum was applied. The vacuum degree was set to 1 Pa. The mold was then heated and the heating rate was controlled at 1℃ / h. The temperature was raised to 30℃ and kept warm for 24 hours. After cooling, three-dimensional graphene was obtained.

[0039] (6) Add three-dimensional graphene into a tube furnace, introduce a mixture of hydrogen and argon, control the volume ratio of hydrogen to argon to be 1:9, raise the temperature to 1000℃, raise the temperature rate to 10℃ / min, keep the reaction time for 3h, and obtain large-size graphene aerogel after cooling.

[0040] (7) After soaking the large-size graphene aerogel in 75% hydrazine hydrate, it was placed in a desiccator, then the desiccator was sealed and placed in a forced-air drying oven. The temperature was raised to 90℃ for the first time, and the heating rate was 1℃ / min. The reaction was carried out for 24 hours. After the reaction was completed, the temperature of the forced-air drying oven was raised to 200℃ and the reaction was kept at a constant temperature for 30 minutes. After cooling, the heat-treated large-size graphene aerogel was obtained.

[0041] (8) Mix the dispersion and curing agent vinyltriamine evenly, and control the mass ratio of the dispersion to the curing agent vinyltriamine to be 10:1 to obtain the curing liquid. Pour the curing liquid into the mold, immerse the heat-treated large-size graphene aerogel into the curing liquid, so that the large-size graphene aerogel absorbs the curing liquid to saturation, and perform vacuum drying. Vacuum the aerogel to -0.1MPa and dry for 2 hours to obtain the cured block. Place the cured block in the drying oven to continue curing. Set the temperature in the drying oven to 80℃ and dry for 6 hours to obtain the sound-absorbing and conductive core material.

[0042] (9) Place the sound-absorbing and conductive core material between two layers of polyvinyl chloride foam board, use phenolic resin as an adhesive to bond the two together, and then press and shape it to obtain a sound-absorbing and conductive composite board.

[0043] Example 2

[0044] A sound-absorbing and conductive composite board, by weight, mainly comprises: 50 parts sound-absorbing and conductive core material, 100 parts polyvinyl chloride foam board, and 200 parts phenolic resin adhesive; the foam material is obtained by processing basalt, polyurethane, and polyacrylate; the sound-absorbing and conductive core material is obtained by processing foam material, styrene, and three-dimensional graphene.

[0045] A method for preparing a sound-absorbing and conductive composite plate, the method mainly includes the following preparation steps:

[0046] (1) After cleaning the basalt, ball milling was performed. The basalt particles after ball milling were 3 mm in diameter and the ball milling time was 5 min. The basalt particles were placed in a mold for later use. The polyurethane particles were placed in a three-necked flask equipped with a stirrer and heated in an oil bath at a constant temperature. Initial stirring was started at an oil bath temperature of 230°C and an initial stirring speed of 200 r / min until the polyurethane melted. The stirring speed was adjusted and a second stirring was performed at a second stirring speed of 800 r / min for 6 min. The melted polyurethane was then poured into a mold, the mold was sealed, and a vacuum was drawn with a vacuum degree of -0.1 MPa. The vacuumed mold was then placed in a constant temperature drying oven for curing at a temperature of 80°C for 10 h to obtain pretreated particles.

[0047] (2) Place the pretreated particles in a vacuum press and perform vacuum pressure treatment. Set the power of the vacuum press to 100W, the pressure to 2 atmospheres, the time to 10min, and the vacuum degree to 2Pa.

[0048] (3) Add the pretreated particles after vacuum pressure treatment to the polyacrylate foaming system, add the foaming agent sodium bicarbonate, and the mass ratio of pretreated particles, polyacrylate and foaming agent sodium bicarbonate is 5:7:0.3. Start stirring, the stirring speed is 1000r / min, the stirring time is 15min, and then solidify after stirring. After solidification, the foamed material is obtained.

[0049] (4) After ball milling the foaming material, foaming material powder is obtained. The foaming material powder is added to styrene, and the mass ratio of foaming material powder to styrene is controlled to be 3:4. After being dispersed evenly, a dispersion is obtained.

[0050] (5) Graphene oxide was prepared into a graphene dispersion with a concentration of 20 mg / ml, which was ultrasonically dispersed and diluted to a dispersion with a concentration of 10 mg / ml. The dispersion was poured into a freeze-drying mold. The freeze dryer was first set to freezing mode and cooled to -45℃ for 4 hours. Then the freeze dryer was set to drying mode and vacuum was applied. The vacuum degree was set to 1 Pa. The mold was then heated and the heating rate was controlled at 1℃ / h. The temperature was raised to 30℃ and kept warm for 24 hours. After cooling, three-dimensional graphene was obtained.

[0051] (6) Add three-dimensional graphene into a tube furnace, introduce a mixture of hydrogen and argon, control the volume ratio of hydrogen to argon to be 1:9, raise the temperature to 1000℃, raise the temperature rate to 10℃ / min, keep the reaction time for 2h, and obtain large-size graphene aerogel after cooling.

[0052] (7) After soaking the large-size graphene aerogel in 75% hydrazine hydrate, it was placed in a desiccator, then the desiccator was sealed and placed in a forced-air drying oven. The temperature was raised to 90℃ for the first time, and the heating rate was 1℃ / min. The reaction was carried out for 24 hours. After the reaction was completed, the temperature of the forced-air drying oven was raised to 200℃ and the reaction was kept at a constant temperature for 30 minutes. After cooling, the heat-treated large-size graphene aerogel was obtained.

[0053] (8) Mix the dispersion and curing agent vinyltriamine evenly, and control the mass ratio of dispersion to curing agent vinyltriamine to be 9:1 to obtain curing liquid. Pour the curing liquid into a mold, immerse the heat-treated large-size graphene aerogel into the curing liquid, so that the large-size graphene aerogel absorbs the curing liquid to saturation, and perform vacuum drying. Vacuum the aerogel to -0.1MPa and dry for 1 hour to obtain a cured block. Place the cured block in a drying oven to continue curing. Set the temperature in the drying oven to 80℃ and dry for 5 hours to obtain sound-absorbing and conductive core material.

[0054] (9) Place the sound-absorbing and conductive core material between two layers of polyvinyl chloride foam board, use phenolic resin as an adhesive to bond the two together, and then press and shape it to obtain a sound-absorbing and conductive composite board.

[0055] Comparative Example 1

[0056] A sound-absorbing and conductive composite board, by weight, mainly comprises: 120 parts polyvinyl chloride foam board and 300 parts phenolic resin adhesive; the foaming material is obtained by processing basalt, polyurethane, and polyacrylate.

[0057] A method for preparing a sound-absorbing and conductive composite plate, the method mainly includes the following preparation steps:

[0058] (1) After cleaning the basalt, ball milling is performed. The particle size of the basalt particles after ball milling is 3~5mm. The ball milling time is 5~10min. Basalt particles are obtained and placed in a mold for later use. Polyurethane particles are placed in a three-necked flask equipped with a stirrer. The flask is heated at a constant temperature in an oil bath and initial stirring is started. The oil bath temperature is 230~240℃ and the initial stirring speed is 200r / min until the polyurethane melts. The stirring speed is adjusted and a second stirring is performed. The second stirring speed is 800r / min and the stirring time is 6~10min. Then the melted polyurethane is poured into the mold. The mold is sealed and vacuumed. The vacuum degree is set to -0.1MPa. The vacuumed mold is then placed in a constant temperature drying oven for curing. The temperature is set to 80℃ and the drying time is 10~12h to obtain pretreated particles.

[0059] (2) Place the pretreated particles in a vacuum press and perform vacuum pressure treatment. Set the power of the vacuum press to 100W, the pressure to 2 atmospheres, the time to 10~20min, and the vacuum degree to 2~3Pa.

[0060] (3) Add the pretreated particles after vacuum pressure treatment to the polyacrylate foaming system, add the foaming agent sodium bicarbonate, and the mass ratio of pretreated particles, polyacrylate and foaming agent sodium bicarbonate is 5:7:0.3~5:7:0.5. Start stirring, the stirring speed is 1000r / min, the stirring time is 15~20min, and after stirring, it is cured to obtain the foamed material.

[0061] (4) Place the foaming material between two layers of polyvinyl chloride foam board, use phenolic resin as an adhesive to bond the two together, and then press and shape it to obtain a sound-absorbing and conductive composite board.

[0062] Comparative Example 2

[0063] A sound-absorbing and conductive composite board, by weight, mainly comprises: 60 parts sound-absorbing and conductive core material, 120 parts polyvinyl chloride foam board, and 300 parts phenolic resin adhesive; wherein the sound-absorbing and conductive core material is obtained by processing foam material, styrene, and three-dimensional graphene.

[0064] A method for preparing a sound-absorbing and conductive composite plate, the method mainly includes the following preparation steps:

[0065] (1) Basalt powder is obtained by ball milling basalt. The basalt powder is added to styrene and the mass ratio of foaming material powder to styrene is controlled to be 3:5. After being dispersed evenly, a dispersion is obtained.

[0066] (2) Graphene oxide was prepared into a graphene dispersion with a concentration of 20 mg / ml, which was ultrasonically dispersed evenly and diluted to a dispersion with a concentration of 10 mg / ml. The dispersion was poured into a freeze-drying mold. The freeze dryer was first set to freezing mode and cooled to -45℃ for 5 hours. Then the freeze dryer was set to drying mode and vacuum was applied. The vacuum degree was set to 1 Pa. The mold was then heated and the heating rate was controlled at 1℃ / h. The temperature was raised to 30℃ and kept warm for 24 hours. After cooling, three-dimensional graphene was obtained.

[0067] (3) Three-dimensional graphene was added into a tube furnace, and a mixture of hydrogen and argon was introduced. The volume ratio of hydrogen to argon was controlled to be 1:9. The temperature was raised to 1000℃, the heating rate was 10℃ / min, the heat preservation reaction time was 3h, and large-size graphene aerogel was obtained after cooling.

[0068] (4) After soaking the large-size graphene aerogel in 75% hydrazine hydrate, it was placed in a desiccator, then the desiccator was sealed and placed in a forced-air drying oven. The temperature was raised to 90℃ for the first time, and the heating rate was 1℃ / min. The reaction was carried out for 24 hours. After the reaction was completed, the temperature of the forced-air drying oven was raised to 200℃ and the reaction was kept at a constant temperature for 30 minutes. After cooling, the heat-treated large-size graphene aerogel was obtained.

[0069] (5) Mix the dispersion and curing agent vinyltriamine evenly, and control the mass ratio of the dispersion to the curing agent vinyltriamine to be 10:1 to obtain the curing liquid. Pour the curing liquid into the mold, immerse the heat-treated large-size graphene aerogel into the curing liquid, so that the large-size graphene aerogel absorbs the curing liquid to saturation, and perform vacuum drying. Vacuum the vacuum to -0.1MPa and dry for 2 hours to obtain the cured block. Place the cured block in the drying oven to continue curing. Set the temperature in the drying oven to 80℃ and dry for 6 hours to obtain the sound-absorbing and conductive core material.

[0070] (6) Place the sound-absorbing and conductive core material between two layers of polyvinyl chloride foam board, use phenolic resin as an adhesive to bond the two together, and then press and shape it to obtain a sound-absorbing and conductive composite board.

[0071] Example of effect 1

[0072] Table 1 below presents the sound absorption performance analysis results of the sound-absorbing and conductive composite plates prepared using the components of Example 1, Example 2 and Comparative Example 2 of this invention.

[0073] Table 1

[0074]

[0075] Decibels are mainly used to measure the intensity of sound. The environmental noise limit stipulates that KTVs should not exceed 70 decibels during the day. As shown in the table above, the sound-absorbing and conductive composite board prepared by the components of Example 1 has a better sound absorption effect than Example 2 and Comparative Example 2. This indicates that vacuum pressure treatment can squeeze out the air inside the pretreated particles. The polyurethane filling inside the particles becomes uneven due to the air overflow, which increases the sound absorption performance of the material.

[0076] Example 2

[0077] Table 2 below shows the conductivity analysis results of the sound-absorbing and conductive composite plates prepared using the components of Example 1, Example 2 and Comparative Example 1 of this invention.

[0078] Table 2

[0079]

[0080] Resistivity is an important indicator of the conductivity of conductive materials; the higher the resistivity, the worse the conductivity. As shown in the table above, the sound-absorbing and conductive composite board prepared in Example 1 exhibits better conductivity than that of Example 2 and Comparative Example 1. This indicates that using graphene as the core material skeleton, while ensuring its sound absorption performance, also increases the mechanical properties of the sound-absorbing and conductive core material. Simultaneously, the limiting effect of the dispersion liquid and large-size graphene aerogel on the foaming material powder increases the dispersibility and stability of the foaming material powder, thus achieving the conductive performance of the sound-absorbing and conductive composite board.

[0081] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for preparing a sound-absorbing and conductive composite plate, characterized in that, The process flow for preparing the sound-absorbing and conductive composite board is as follows: filler, vacuum pressure treatment, mixing, dispersion preparation, three-dimensional graphene preparation, large-size graphene aerogel preparation, heat treatment, filling, and finished product. The method for preparing the sound-absorbing and conductive composite plate includes the following specific steps: (1) After cleaning the basalt, ball milling is performed to obtain basalt particles. The basalt particles are placed in a mold for later use. The polyurethane particles are placed in a three-necked flask equipped with a stirrer, heated at a constant temperature in an oil bath and stirred initially until the polyurethane melts. The stirring speed is adjusted for secondary stirring. The melted polyurethane is then poured into the mold, the mold is sealed, and a vacuum is applied. The vacuum-treated mold is then placed in a constant temperature drying oven for curing to obtain pre-treated particles. (2) Place the pretreated particles in a vacuum press and perform vacuum pressure treatment. Set the power of the vacuum press to 100W, the pressure to 2 atmospheres, the time to 10~20min, and the vacuum degree to 2~3Pa. (3) Add the pretreated particles after vacuum pressure treatment to the polyacrylate foaming system, add the foaming agent sodium bicarbonate, start stirring, and then cure after stirring. After curing, the foamed material is obtained. (4) After ball milling the foaming material, foaming material powder is obtained. The foaming material powder is added to styrene, and the mass ratio of foaming material powder to styrene is controlled to be 3:4~3:

5. After being dispersed evenly, a dispersion is obtained. (5) Prepare graphene oxide into a graphene dispersion with a concentration of 20 mg / ml, disperse it evenly by ultrasonication, dilute it into a dispersion with a concentration of 10 mg / ml, pour the dispersion into a freeze-drying mold, first set the freeze dryer to the freezing mode, cool it down and freeze it, then set the freeze dryer to the drying mode, perform vacuuming, set the vacuum degree to 1 Pa, then heat the mold, keep it warm for a period of time, and obtain three-dimensional graphene after cooling. (6) Add three-dimensional graphene into a tube furnace, introduce a mixture of hydrogen and argon, raise the temperature to 1000℃, keep the reaction at the temperature, and obtain large-size graphene aerogel after cooling. (7) After soaking the large-size graphene aerogel in 75% hydrazine hydrate, put it into a desiccator, then seal the desiccator and put it into a forced-air drying oven. The temperature is raised to 90°C for the first time to start the reaction. After the reaction is completed, the temperature of the forced-air drying oven is raised to 200°C and the reaction is kept at a constant temperature. After cooling, the heat-treated large-size graphene aerogel is obtained. (8) Mix the dispersion and curing agent vinyltriamine evenly to obtain a curing liquid. Pour the curing liquid into a mold and immerse the heat-treated large-size graphene aerogel into the curing liquid so that the large-size graphene aerogel absorbs the curing liquid to saturation. Perform vacuum drying to obtain a cured block. Place the cured block in a drying oven to continue curing to obtain a sound-absorbing and conductive core material. (9) Place the sound-absorbing and conductive core material between two layers of polyvinyl chloride foam board, use phenolic resin as an adhesive to bond the two together, and then press and shape it to obtain a sound-absorbing and conductive composite board.

2. The method for preparing a sound-absorbing and conductive composite plate according to claim 1, characterized in that, In step (1) above, the basalt particles after ball milling have a particle size of 3~5mm, the ball milling time is 5~10min, the oil bath temperature is 230~240℃, the initial stirring speed is 200r / min, the secondary stirring speed is 800r / min, the stirring time is 6~10min, the vacuum degree is set to -0.1MPa, and the temperature is 80℃ and the drying time is 10~12h during constant temperature blower drying.

3. The method for preparing a sound-absorbing and conductive composite plate according to claim 1, characterized in that, In step (3) above, the mass ratio of pretreated particles, polyacrylate and foaming agent sodium bicarbonate is 5:7:0.3~5:7:0.5, the stirring rate is 1000r / min, and the stirring time is 15~20min.

4. The method for preparing a sound-absorbing and conductive composite plate according to claim 1, characterized in that, In step (5) above, the temperature is lowered to -45℃ and the freezing time is 4~5h; the heating rate is controlled at 1℃ / h, the temperature is raised to 30℃, and the holding time is 24h.

5. The method for preparing a sound-absorbing and conductive composite plate according to claim 1, characterized in that, In step (6) above, the volume ratio of hydrogen to argon is 1:9; the heating rate is 10℃ / min; and the holding time is 2~3h.

6. The method for preparing a sound-absorbing and conductive composite plate according to claim 1, characterized in that, In step (7) above, the first heating rate is 1℃ / min, the reaction time is 24h, and the constant temperature reaction time is 30min.

7. The method for preparing a sound-absorbing and conductive composite plate according to claim 1, characterized in that, In step (8) above, the mass ratio of dispersion to curing agent vinyltriamine is 9:1 to 10:1; vacuum is applied to -0.1 MPa, and the drying time is 1 to 2 hours; the temperature in the drying oven is 80°C, and the drying time is 5 to 6 hours.

8. The method for preparing a sound-absorbing and conductive composite plate according to claim 1, characterized in that, The sound-absorbing and conductive composite board prepared by the method described herein comprises the following raw materials in parts by weight: 50-60 parts sound-absorbing and conductive core material, 100-120 parts polyvinyl chloride foam board, and 200-300 parts phenolic resin adhesive; the foam material is prepared by processing basalt, polyurethane, and polyacrylate; the sound-absorbing and conductive core material is prepared by processing foam material, styrene, and three-dimensional graphene.

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