A paper-faced gypsum board and a process for producing the same

Abstract

The application relates to the technical field of gypsum boards, and particularly discloses a paper-faced gypsum board and a production process thereof. The paper-faced gypsum board comprises a board core and face paper adhered to two surfaces of the board core, and the raw materials of the board core comprise: 80-120 parts of plaster clinker; 5-15 parts of vermiculite powder; 5-10 parts of modified elastic microspheres; 6-12 parts of porous sound insulation mineral particles; 3-7 parts of glass fiber; 5-10 parts of silica aerogel particles; 3-7 parts of aluminum hydroxide powder; 2-5 parts of acrylate emulsion; 2-5 parts of talcum powder; 0.5-2 parts of water reducing agent; and 30-50 parts of water; the modified elastic microspheres are nitrile rubber microspheres coated with ethylene-vinyl acetate copolymer. The paper-faced gypsum board of the application effectively improves the crack resistance and sound insulation performance of the paper-faced gypsum board through the synergistic effect of the modified elastic microspheres, the porous sound insulation mineral particles and other raw materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gypsum board, more specifically, it relates to a paper-faced gypsum board and a production process thereof. BACKGROUND

[0002] Paper-faced gypsum board is a lightweight building board made of building gypsum as the main raw material, mixed with a proper amount of additives and fiber reinforced materials, through processes such as water mixing, pulp making, molding, cutting, and drying. Its core structure is composed of two layers of high-strength face paper and an intermediate gypsum core material, and has the advantages of light weight, fireproof, sound insulation, and convenient construction, and is widely used in indoor suspended ceilings, partition walls, and decoration engineering. With the characteristics of strong processability and recyclability, paper-faced gypsum board has become one of the most widely used wall and ceiling materials in modern construction.

[0003] In the related art, a patent application file with publication number CN114380566A discloses a water-resistant high-strength paper-faced gypsum board and a preparation method thereof. The preparation raw materials of the water-resistant high-strength paper-faced gypsum board include: gypsum clinker, hydrogen-containing silicone oil, inert silicone oil, emulsifier, carbon nanotube, emulsion, fiber, binder, water reducing agent, foaming agent, and water. The water-resistant high-strength paper-faced gypsum board in the above technical solution has ultra-low water absorption, ultra-low surface water absorption, and excellent mechanical properties. It solves the problem of softening and strength decay of traditional gypsum board in a humid environment.

[0004] However, although the above-mentioned related technical solution significantly improves the water resistance and mechanical properties of the paper-faced gypsum board by adding modified components such as hydrogen-containing silicone oil and carbon nanotubes, the improvement direction is still focused on optimizing the material properties, and the key problems in engineering application have not been effectively solved. On the one hand, the interface stress problem caused by the difference in thermal expansion coefficient of the gypsum core material has not been fundamentally improved, and in an environment with large fluctuations in temperature and humidity, the joints of the gypsum board are still prone to cracking due to stress concentration, affecting the appearance and durability of the building. On the other hand, the existing gypsum board has limited sound barrier effect on low-frequency sound waves, and the sound insulation performance of conventional thickness board is difficult to meet the high-standard sound insulation requirements of residential, school, and other places, and increasing the thickness of the board to improve the sound insulation amount will significantly increase the cost and construction complexity. Therefore, developing a paper-faced gypsum board with high crack resistance and excellent sound insulation performance has become a technical problem to be solved in the field. SUMMARY

[0005] In order to improve the crack resistance and sound insulation performance of the paper-faced gypsum board, the present application provides a paper-faced gypsum board and a production process thereof.

[0006] The paper-faced gypsum board and the production process thereof provided by the present application adopt the following technical solution:

[0007] A paper-faced gypsum board includes a core and facing paper adhered to both sides of the core, wherein the core comprises the following raw materials in parts by weight:

[0008] 80-120 parts of gypsum clinker;

[0009] 5-15 parts vermiculite powder;

[0010] 5-10 parts of modified elastic microspheres;

[0011] 6-12 parts of porous sound-insulating mineral particles;

[0012] 3-7 parts glass fiber;

[0013] 5-10 parts of silica aerogel particles;

[0014] 3-7 parts of aluminum hydroxide micro powder;

[0015] 2-5 parts of acrylic emulsion;

[0016] 2-5 parts talcum powder;

[0017] Water-reducing agent 0.5-2 parts;

[0018] 30-50 parts water;

[0019] The modified elastic microspheres are nitrile rubber microspheres coated with ethylene-vinyl acetate copolymer.

[0020] By adopting the above technical solution, the modified elastic microspheres introduced into the formula, obtained by coating nitrile rubber microspheres with ethylene-vinyl acetate copolymer, are the core component for crack resistance. Due to the high elasticity of nitrile rubber, it can buffer the difference in thermal expansion coefficients between the gypsum core material and the facing paper, reducing interfacial stress caused by temperature and humidity changes. The outer ethylene-vinyl acetate copolymer has excellent compatibility with gypsum clinker and acrylic emulsion, enhancing the bonding force between the microspheres and the core material, preventing localized stress concentration caused by microsphere detachment, and fundamentally reducing the risk of joint cracking. Simultaneously, the addition of glass fiber forms a three-dimensional support network, improving the overall tensile strength of the core material and further inhibiting crack formation. Talc powder optimizes the fluidity of the gypsum slurry, reducing internal porosity and stress defects during the molding process, indirectly improving crack resistance.

[0021] The porous sound-insulating mineral particles in the above components absorb low- and mid-frequency sound waves through their porous structure, thus consuming sound energy. Silica aerogel particles are ultra-low-density porous materials; their nanoscale pores effectively block sound wave propagation, especially high-frequency sound waves. Together with the gypsum core material, they form a "porous-aerogel" composite sound insulation structure, significantly improving overall sound insulation without increasing the board thickness, meeting the high standards required for residences, schools, and other similar locations. Furthermore, the layered structure of vermiculite powder further weakens sound wave transmission, and while aluminum hydroxide micropowder primarily functions as a flame retardant, it also helps improve sound insulation performance by filling pores and optimizing the core material density distribution.

[0022] The gypsum board core prepared by the above components has excellent crack resistance and also effectively enhances the sound insulation performance of the paper-faced gypsum board.

[0023] Optionally, the modified elastic microspheres are prepared by the following method:

[0024] (1) Add nitrile rubber microspheres to deionized water and stir at 600-800 r / min for 30-50 min to form a dispersion;

[0025] (2) After mixing ethylene-vinyl acetate copolymer with deionized water, heat the mixture to 60-70℃, add dioctyl phthalate and stir for 20-30 min to obtain the coating solution;

[0026] (3) Add the coating solution to the dispersion at a rate of 1-2 mL / min, heat to 75-85℃ and stir at 800-1000 r / min. After the addition is complete, add ammonium persulfate, keep warm and stir for 2-3 hours, cool down and let stand, then centrifuge to separate, and obtain modified elastic microspheres after washing and drying.

[0027] By adopting the above technical solution, the above preparation method prepares "dispersion liquid-coating liquid-polymer coating" in steps, which can ensure that the nitrile rubber microspheres are uniformly coated by the ethylene-vinyl acetate copolymer: avoid uneven elastic distribution caused by microsphere agglomeration, ensure consistent stress buffering capacity in all areas of the core material, prevent local cracks caused by microsphere loss, and thus help ensure the crack resistance of the core.

[0028] Optionally, in step (1), the mass ratio of nitrile rubber microspheres to deionized water is 1:(15-25).

[0029] By adopting the above technical solution, the above ratio can form a stable low-concentration dispersion, which avoids microsphere agglomeration due to insufficient water and prevents excessive water from increasing subsequent drying energy consumption. At the same time, the low-concentration dispersion allows the copolymer to adhere more precisely to the surface of individual microspheres when the coating liquid is added later, forming a coating layer of uniform thickness, ensuring that the elastic buffering effect of each microsphere is consistent.

[0030] Optionally, in step (2), the mass ratio of ethylene-vinyl acetate copolymer to deionized water is 1:(4-8), and the amount of dioctyl phthalate added is 10%-20% of the ethylene-vinyl acetate copolymer.

[0031] Optionally, in step (3), the mass ratio of the coating solution to the dispersion is 1:(3-5); the amount of ammonium persulfate added is 0.5%-1% of the total mass of the coating solution and the dispersion.

[0032] By adopting the above technical solution, the above ratio ensures that the coating liquid can completely cover the microspheres in the dispersion, and no uncoated "bare spheres" appear (bare spheres are prone to poor compatibility with gypsum core material, leading to local defects); ammonium persulfate, as an initiator, can efficiently initiate the copolymer polymerization reaction to form a dense coating layer. If the addition amount is too low, the polymerization will be insufficient and the coating layer will easily fall off; if it is too high, too many polymerization by-products will be generated, affecting the elasticity of the microspheres. This ratio can achieve a balance between polymerization efficiency and microsphere performance.

[0033] Optionally, the porous sound-insulating mineral particles are prepared by the following method:

[0034] A. Soak expanded perlite particles in a silane coupling agent-ethanol solution for 2-3 hours, filter, and dry at 60-80℃ to obtain active expanded perlite.

[0035] B. Mix diatomaceous earth with nano-titanium dioxide sol, sonicate for 30-40 minutes, and then dry at 120-150℃ to obtain photocatalytically modified diatomaceous earth;

[0036] C. Mix activated expanded perlite and photocatalytic modified diatomite, add water-based epoxy resin emulsion, and press under 15-20 MPa pressure to obtain composite mineral particles.

[0037] D. The composite mineral particles are first calcined at 300-400℃ for 1-2 hours, then heated to 700-800℃ and calcined for 2-3 hours. After natural cooling, porous sound-insulating mineral particles are obtained.

[0038] By adopting the above technical solution and the above method, composite particles with both high porosity and structural strength are prepared: the porous structure of expanded perlite is the basis for sound insulation, the micropores of diatomite can further refine the pore distribution, and gradient calcination (pre-calcination at 300-400℃ to remove impurities, and calcination at 700-800℃ to strengthen the structure) can prevent the particles from collapsing during calcination and ensure the stability of the pore structure. Therefore, the contradiction between the incompatibility between porosity and strength of traditional porous particles is solved, which can ensure the sound insulation effect and withstand the pressure of gypsum board molding without breaking.

[0039] Optionally, in step A, the mass fraction of silane coupling agent in the silane coupling agent-ethanol solution is 5%-8%; the mass ratio of expanded perlite particles to silane coupling agent-ethanol solution is 1:(8-12).

[0040] Optionally, in step B, the mass concentration of the nano-titanium dioxide sol is 3%-5%; the mass ratio of the diatomaceous earth to the nano-titanium dioxide sol is 10:(1-2).

[0041] Optionally, in step C, the mass ratio of activated expanded perlite to photocatalytic modified diatomite is (3-5):1; the amount of waterborne epoxy resin emulsion added accounts for 2%-4% of the total mass of activated expanded perlite and photocatalytic modified diatomite.

[0042] By adopting the above technical solution, the above ratio allows the particles to use the large pores of perlite as the "main sound insulation channel" and the small pores of diatomite as the "auxiliary sound insulation channel," forming a "gradient pore structure"—the large pores can initially block high-frequency sound waves, while the small pores can absorb mid- and low-frequency sound waves, resulting in a wider sound insulation band; the addition of 2%-4% epoxy resin can form a bonding network inside the particles, improving structural strength, while not clogging the pores (if the addition is too high, it will fill the pores and reduce the sound insulation effect), ensuring that the particles in the gypsum core material can maintain sound insulation performance and withstand external forces during construction and use.

[0043] Secondly, this application also provides a production process for paper-faced gypsum board, employing the following technical solution:

[0044] A production process for paper-faced gypsum board includes the following steps:

[0045] S1. Mix gypsum clinker, vermiculite powder, talc powder, and water-reducing agent and stir for 10-20 minutes. Then add modified elastic microspheres and porous sound-insulating mineral particles and stir for 6-10 minutes. Then add glass fiber, silica aerogel particles, aluminum hydroxide micro powder, acrylic emulsion, and water and stir for 30-50 minutes to obtain gypsum slurry.

[0046] S2. Lay the facing paper on the upper and lower conveyor belts of the molding machine, pour the gypsum slurry from step S1 evenly onto the lower facing paper, cover it with the upper facing paper, and extrude it through the extrusion rollers to form it. Control the molding pressure to 0.4-0.6MPa to obtain the gypsum board blank. Place the gypsum board blank in a pre-curing chamber at 45-55℃ for 1.5-2.5h, and then transfer it to a drying kiln at 130-150℃ for 5-7h to obtain paper-faced gypsum board.

[0047] By adopting the above technical solution, the above preparation method first mixes inorganic raw materials such as gypsum clinker and vermiculite powder, then adds modified elastic microspheres and porous sound insulation particles, and finally adds glass fiber and liquid components. This can prevent the elastic microspheres from being scratched by glass fiber, thus avoiding affecting the integrity of the coating layer. It also prevents the sound insulation particles from being soaked by the liquid added earlier, which would cause the pores to absorb water and become blocked, thus avoiding affecting the sound insulation. This ensures that the functional components are evenly distributed in the core material and that the performance is stable.

[0048] In summary, this application has the following beneficial effects:

[0049] 1. This application employs a crack-resistant synergistic system composed of modified elastic microspheres and glass fibers. The modified elastic microspheres rely on the high elasticity of nitrile rubber to buffer interfacial stress, while the outer ethylene-vinyl acetate copolymer enhances the bonding force with the core material; the glass fibers can form a three-dimensional support network, improving the overall tensile strength of the core material. The two work together to address the problem from two dimensions: stress buffering and structural reinforcement, ultimately significantly reducing the risk of joint cracking in gypsum board under fluctuating temperature and humidity conditions, and greatly improving the durability of the board.

[0050] 2. This application preferably employs a composite sound insulation structure composed of porous sound-insulating mineral particles and silica aerogel particles. The porous sound-insulating mineral particles undergo gradient calcination treatment to form a gradient pore structure, which can specifically adsorb mid-to-low frequency sound waves; the nanoscale pores of the silica aerogel particles can efficiently block high frequency sound waves. The combined effect of these two materials achieves wide-band sound insulation without increasing the board thickness, significantly improving the sound insulation performance of conventionally thick paper-faced gypsum board. This meets the high-standard sound insulation requirements of residences, schools, and other similar locations, while avoiding the increased cost and construction complexity caused by thicker boards.

[0051] 3. In the preparation method of this application, modified elastic microspheres and porous sound-insulating mineral particles are prepared in steps. For example, the microspheres are prepared using a dispersion, coating, and polymerization process, while the particles are prepared using a modification, composite, and gradient calcination process. Simultaneously, the mixing sequence of the gypsum slurry is optimized: inorganic raw materials are mixed first, then functional particles are added, and finally liquid components are added. The molding and curing parameters are also optimized, controlling the molding pressure at 0.4-0.6 MPa, and using a gradient temperature zone for curing and drying. These operations ensure the stable performance of the functional components and their uniform distribution in the core material, ultimately achieving synergistic compliance of the crack resistance and sound insulation performance of the paper-faced gypsum board, while also ensuring the stability of the production process and the yield rate. Detailed Implementation

[0052] The present application will be further described in detail below with reference to the embodiments.

[0053] Preparation example of modified elastic microspheres

[0054] Preparation Example 1

[0055] Modified elastic microspheres were prepared by the following method:

[0056] (1) Add 1 kg of nitrile rubber microspheres to 15 kg of deionized water and stir at 600 r / min for 50 min to form a dispersion;

[0057] (2) Mix 1 kg of ethylene-vinyl acetate copolymer with 4 kg of deionized water and heat to 60 °C. Add 0.1 kg of dioctyl phthalate and stir for 30 min to obtain the coating solution.

[0058] (3) 5 kg of coating solution was added dropwise to 15 kg of dispersion at 1 mL / min, then the temperature was raised to 75 °C and stirred at 800 r / min. After the dropwise addition was complete, 0.1 kg of ammonium persulfate was added, and the mixture was kept warm and stirred for 3 h. After cooling and standing, the mixture was centrifuged at 3000 r / min for 20 min, the solid particles were collected, washed with deionized water until neutral, and finally dried in a vacuum drying oven at 60 °C for 6 h to obtain modified elastic microspheres.

[0059] Preparation Example 2

[0060] Modified elastic microspheres were prepared by the following method:

[0061] (1) Add 1 kg of nitrile rubber microspheres to 20 kg of deionized water and stir at 700 r / min for 40 min to form a dispersion;

[0062] (2) Mix 1 kg of ethylene-vinyl acetate copolymer with 6 kg of deionized water and heat to 65 °C. Add 0.15 kg of dioctyl phthalate and stir for 25 min to obtain the coating solution.

[0063] (3) 5 kg of coating solution was added dropwise to 20 kg of dispersion at 1.5 mL / min. Then the temperature was raised to 80 °C and stirred at 900 r / min. After the dropwise addition was complete, 0.2 kg of ammonium persulfate was added and the mixture was kept warm and stirred for 2.5 h. After cooling and standing, the mixture was centrifuged at 3500 r / min for 18 min. The solid particles were collected, washed with deionized water until neutral, and finally dried in a vacuum drying oven at 65 °C for 5 h to obtain modified elastic microspheres.

[0064] Preparation Example 3

[0065] Modified elastic microspheres were prepared by the following method:

[0066] (1) Add 1 kg of nitrile rubber microspheres to 25 kg of deionized water and stir at 800 r / min for 30 min to form a dispersion;

[0067] (2) Mix 1 kg of ethylene-vinyl acetate copolymer with 8 kg of deionized water and heat to 70 °C. Add 0.2 kg of dioctyl phthalate and stir for 20 min to obtain the coating solution.

[0068] (3) 5 kg of coating solution was added dropwise to 25 kg of dispersion at 2 mL / min, then the temperature was raised to 85 °C and stirred at 1000 r / min. After the dropwise addition was complete, 0.3 kg of ammonium persulfate was added, and the mixture was kept warm and stirred for 2 h. After cooling and standing, the mixture was centrifuged at 4000 r / min for 15 min, the solid particles were collected, washed with deionized water until neutral, and finally dried in a vacuum drying oven at 70 °C for 4 h to obtain modified elastic microspheres.

[0069] Example of preparation of porous sound-insulating mineral particles

[0070] Preparation Example 4

[0071] Porous sound-insulating mineral particles are prepared by the following method:

[0072] A. Soak 1 kg of expanded perlite particles with an average particle size of 1 mm in 8 kg of 5% KH-470-ethanol solution for 2 h, filter, and dry at 60 °C to obtain active expanded perlite.

[0073] B. Mix 1 kg of diatomaceous earth with an average particle size of 80 μm with 0.1 kg of nano-titanium dioxide sol with a mass concentration of 3%, sonicate at 300 W for 40 min, and then dry in an oven at 120 °C to obtain photocatalytic modified diatomaceous earth.

[0074] C. Mix 0.9 kg of activated expanded perlite with 0.3 kg of photocatalytic modified diatomite, add 0.024 kg of water-based epoxy resin emulsion and stir evenly. Press under 15 MPa pressure for 5 min to obtain composite mineral particles.

[0075] D. Place the composite mineral particles into a muffle furnace, calcine at 300℃ for 2 hours, then raise the temperature to 700℃ and calcine for 3 hours. After natural cooling, porous sound-insulating mineral particles are obtained.

[0076] Preparation Example 5

[0077] Porous sound-insulating mineral particles are prepared by the following method:

[0078] A. Soak 1 kg of expanded perlite particles with an average particle size of 1.2 mm in 10 kg of 6.5% KH-470-ethanol solution of silane coupling agent for 2.5 h, filter, and dry at 70 °C to obtain active expanded perlite.

[0079] B. Mix 1 kg of diatomaceous earth with an average particle size of 90 μm with 0.15 kg of nano-titanium dioxide sol with a mass concentration of 4%, sonicate at 350 W for 35 min, and then dry in an oven at 135 ° C to obtain photocatalytic modified diatomaceous earth.

[0080] C. Mix 0.9 kg of activated expanded perlite with 0.3 kg of photocatalytic modified diatomite, add 0.036 kg of water-based epoxy resin emulsion and stir evenly. Press under 18 MPa pressure for 4 min to obtain composite mineral particles.

[0081] D. Place the composite mineral particles into a muffle furnace, calcine at 350℃ for 1.5 hours, then raise the temperature to 750℃ and calcine for 2.5 hours. After natural cooling, porous sound-insulating mineral particles are obtained.

[0082] Preparation Example 6

[0083] Porous sound-insulating mineral particles are prepared by the following method:

[0084] A. Soak 1 kg of expanded perlite particles with an average particle size of 1.5 mm in 12 kg of 8% KH-470-ethanol solution of silane coupling agent for 3 h, filter, and dry at 80 °C to obtain active expanded perlite.

[0085] B. Mix 1 kg of diatomaceous earth with an average particle size of 100 μm with 0.2 kg of nano-titanium dioxide sol with a mass concentration of 5%, sonicate at 400 W for 30 min, and then dry in an oven at 150 °C to obtain photocatalytic modified diatomaceous earth.

[0086] C. Mix 0.9 kg of activated expanded perlite with 0.3 kg of photocatalytic modified diatomite, add 0.048 kg of water-based epoxy resin emulsion and stir evenly. Press under 20 MPa pressure for 3 min to obtain composite mineral particles.

[0087] D. Place the composite mineral particles into a muffle furnace, calcine at 400℃ for 1 hour, then raise the temperature to 800℃ and calcine for 2 hours. After natural cooling, porous sound-insulating mineral particles are obtained.

[0088] Preparation Example 7

[0089] The porous sound-insulating mineral particles differ from those in Preparation Example 6 in step D. Specifically, step D is as follows:

[0090] The composite mineral particles were placed in a muffle furnace and calcined at 800℃ for 1 hour, then cooled to 300℃ and calcined for 2 hours. After natural cooling, porous sound-insulating mineral particles were obtained.

[0091] Example

[0092] Example 1

[0093] A paper-faced gypsum board includes a core and facing paper adhered to both sides of the core. The facing paper is made of virgin wood pulp. The raw material composition and formulation of the core are shown in Table 1. Specifically, the modified elastic microspheres are those prepared in Preparation Example 1, the porous sound-insulating mineral particles are those prepared in Preparation Example 4, the water-reducing agent is a naphthalene-based water-reducing agent, and the solid content of the acrylic emulsion is 50%.

[0094] The production process of paper-faced gypsum board is as follows:

[0095] S1. Mix gypsum clinker, vermiculite powder, talc powder and water-reducing agent and stir for 10 minutes. Then add modified elastic microspheres and porous sound-insulating mineral particles and stir for 6 minutes. Then add glass fiber, silica aerogel particles, aluminum hydroxide micro powder, acrylic emulsion and water and stir for 30 minutes to obtain gypsum slurry.

[0096] S2. Lay the facing paper on the upper and lower conveyor belts of the molding machine, pour the gypsum slurry from step S1 evenly onto the lower facing paper, cover it with the upper facing paper, and extrude it through the extrusion rollers to form it. Control the molding pressure to 0.4MPa to obtain the gypsum board blank. Place the gypsum board blank in a 45℃ pre-curing chamber for 1.5h, and then transfer it to a 130℃ drying kiln for 5h to obtain paper-faced gypsum board.

[0097] Example 2

[0098] A paper-faced gypsum board includes a core and facing paper adhered to both sides of the core. The facing paper is made of virgin wood pulp. The raw material composition and formulation of the core are shown in Table 1. Specifically, the modified elastic microspheres are those prepared in Preparation Example 2, the porous sound-insulating mineral particles are those prepared in Preparation Example 5, the water-reducing agent is a naphthalene-based water-reducing agent, and the solid content of the acrylic emulsion is 50%.

[0099] The production process of paper-faced gypsum board is as follows:

[0100] S1. Mix gypsum clinker, vermiculite powder, talc powder and water-reducing agent and stir for 15 minutes. Then add modified elastic microspheres and porous sound-insulating mineral particles and stir for 8 minutes. Then add glass fiber, silica aerogel particles, aluminum hydroxide micro powder, acrylic emulsion and water and stir for 40 minutes to obtain gypsum slurry.

[0101] S2. Lay the facing paper on the upper and lower conveyor belts of the molding machine, pour the gypsum slurry from step S1 evenly onto the lower facing paper, cover it with the upper facing paper, and extrude it through the extrusion rollers to form it. Control the molding pressure to 0.5MPa to obtain the gypsum board blank. Place the gypsum board blank in a 50℃ pre-curing chamber for 2 hours, and then transfer it to a 140℃ drying kiln for 6 hours to obtain paper-faced gypsum board.

[0102] Example 3

[0103] A paper-faced gypsum board includes a core and facing paper adhered to both sides of the core. The facing paper is made of virgin wood pulp. The raw material composition and formulation of the core are shown in Table 1. Specifically, the modified elastic microspheres are those prepared in Preparation Example 3, the porous sound-insulating mineral particles are those prepared in Preparation Example 6, the water-reducing agent is a naphthalene-based water-reducing agent, and the solid content of the acrylic emulsion is 50%.

[0104] The production process of paper-faced gypsum board is as follows:

[0105] S1. Mix gypsum clinker, vermiculite powder, talc powder and water-reducing agent and stir for 20 minutes. Then add modified elastic microspheres and porous sound-insulating mineral particles and stir for 10 minutes. Then add glass fiber, silica aerogel particles, aluminum hydroxide micro powder, acrylic emulsion and water and stir for 50 minutes to obtain gypsum slurry.

[0106] S2. Lay the facing paper on the upper and lower conveyor belts of the molding machine, pour the gypsum slurry from step S1 evenly onto the lower facing paper, cover it with the upper facing paper, and extrude it through the extrusion rollers to form it. Control the molding pressure to 0.6MPa to obtain the gypsum board blank. Place the gypsum board blank in a 55℃ pre-curing chamber for 2.5h, and then transfer it to a 150℃ drying kiln for 7h to obtain paper-faced gypsum board.

[0107] Table 1. Raw material composition and dosage (kg) of the core material in Examples 1-3

[0108]

[0109] Example 4

[0110] A paper-faced gypsum board, which differs from Example 1 in that the solid content of the acrylic emulsion in this example is 30%.

[0111] Example 5

[0112] A paper-faced gypsum board, which differs from Example 1 in that the water-reducing agent used in this example is a lignosulfonate water-reducing agent.

[0113] Comparative Example

[0114] Comparative Example 1

[0115] The paper-faced gypsum board was prepared according to the method described in Example 1 of the patent application document with publication number CN114380566A entitled "A water-resistant high-strength paper-faced gypsum board and its preparation method".

[0116] Comparative Example 2

[0117] A paper-faced gypsum board differs from Example 1 in that an equal amount of nitrile rubber microspheres are used instead of modified elastic microspheres in this comparative example.

[0118] Comparative Example 3

[0119] A paper-faced gypsum board differs from Example 1 in that an equal amount of expanded perlite particles are used instead of porous sound-insulating mineral particles in this comparative example.

[0120] Comparative Example 4

[0121] A paper-faced gypsum board, which differs from Example 1 in that silica aerogel particles were not added in this comparative example, and the difference was made up with gypsum clinker.

[0122] Comparative Example 5

[0123] A paper-faced gypsum board, which differs from Example 1 in that the porous sound-insulating mineral particles used in this example are those prepared in Preparation Example 7.

[0124] Performance testing

[0125] The performance of the 20mm thick paper-faced gypsum boards prepared in Examples 1-5 and Comparative Examples 1-5 was tested, and the results are shown in Table 2. Supplementary testing (verifying crack resistance effect) was conducted using a temperature and humidity cycling crack resistance test for this application.

[0126] Temperature and humidity cycle crack resistance test method: Place the gypsum board sample (2440×1220×20) mm in a cycle environment of "-10℃ (2h) → 23℃ / 50%RH (2h) → 40℃ / 90%RH (2h)" for 50 consecutive cycles; Evaluation: After the cycle, observe whether cracks appear on the board surface and at the joints and whether the cracks are extensive. The qualified standard is "no visible cracks (width < 0.05mm)".

[0127] Table 2 Experimental Results

[0128]

[0129] In Examples 1-3, as the amount of modified elastic microspheres and glass fiber increased, the flexural strength of the gypsum board gradually improved from 2.65 MPa to 2.98 MPa, without any cracks. This indicates that the modified elastic microspheres can buffer stress, and the glass fiber can enhance tensile properties. The synergistic effect of the two effectively improves the crack resistance of the gypsum board, reduces the risk of cracking at the joints of paper-faced gypsum board under fluctuating temperature and humidity conditions, and significantly improves the durability of the board.

[0130] In Comparative Example 2, an equal amount of nitrile rubber microspheres were used to replace the modified elastic microspheres. Due to the lack of stress buffering effect of the modified elastic microspheres, the flexural strength dropped sharply to 1.72 MPa and the cracks became dense, directly verifying the core role of the modified elastic microspheres in the crack-resistant system.

[0131] In Comparative Example 5, the porous particles underwent reverse calcination (high temperature followed by low temperature), resulting in a decrease in particle structure integrity and weakened local support of the core material. This led to a slight reduction in flexural strength to 2.61 MPa and the appearance of one microcrack. In contrast, Examples 1-3 employed gradient calcination (low temperature for impurity removal followed by high temperature for strengthening), demonstrating the importance of gradient calcination in maintaining particle strength and ensuring the crack resistance of the gypsum board.

[0132] In Example 5, the solid content of the acrylic emulsion was reduced from 50% to 30%, resulting in a slight decrease in adhesion and a minor decrease in flexural strength to 2.52 MPa. However, no cracks were observed, indicating that the low-solid-content emulsion could still meet the basic bonding requirements. In Example 6, the water-reducing agent was replaced with lignosulfonate. The slurry fluidity was slightly worse, but it did not affect the core material structure. The flexural strength decreased slightly to 2.48 MPa, but no cracks were observed. This indicates that although the water-reducing efficiency was slightly lower with lignosulfonate, the gypsum board still had good crack resistance.

[0133] In Comparative Example 1, the existing water-resistant gypsum board lacks crack-resistant functional components, has a flexural strength as low as 2.15 MPa, and exhibits numerous cracks, further demonstrating the advantages of the crack-resistant system of this application compared to conventional gypsum board.

[0134] In Examples 1-3, as the amount of porous sound-insulating mineral particles and silica aerogel increased, the mid-to-high frequency sound insulation gradually improved, increasing from 30.2 dB to 32.8 dB at 200 Hz and from 38.8 dB to 41.5 dB at 1000 Hz. This demonstrates the synergistic effect of "porous adsorption of mid-to-low frequencies + aerogel blocking of high frequencies," achieving wide-band sound insulation. In Example 4, reverse calcination of the porous sound-insulating mineral particles led to pore blockage, resulting in a decrease in mid-to-low frequency sound insulation, reaching 28.5 dB at 200 Hz and 32.1 dB at 500 Hz. This verifies the importance of gradient calcination on the particle pore structure, as the pore structure affects the adsorption capacity of porous particles for mid-to-low frequency sound waves. In Comparative Example 3, without porous sound-insulating mineral particles, the adsorption of mid-to-low frequency sound waves was insufficient, and the sound insulation at 200 Hz and 500 Hz plummeted to 24.8 dB and 27.5 dB, respectively, demonstrating the crucial role of porous particles in mid-to-low frequency sound insulation. In Comparative Example 4, the core material contained no silica aerogel, resulting in reduced high-frequency sound wave blocking. The sound insulation at 1000Hz decreased to 34.1dB, verifying the core role of aerogel in high-frequency sound insulation. In Comparative Example 1, there was no composite sound insulation structure, and the sound insulation across the entire frequency band was low, demonstrating the advantages of the sound insulation system in this application compared to conventional gypsum board.

[0135] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A paper-faced gypsum board, comprising a core and facing paper adhered to both sides of the core, characterized in that, The core of the board comprises the following raw materials in parts by weight: 80-120 parts gypsum clinker, 5-15 parts vermiculite powder, 5-10 parts modified elastic microspheres, 6-12 parts porous sound-insulating mineral particles, 3-7 parts glass fiber, 5-10 parts silica aerogel particles, 3-7 parts aluminum hydroxide micro powder, 2-5 parts acrylic emulsion, 2-5 parts talc powder, 0.5-2 parts water-reducing agent, and 30-50 parts water; The modified elastic microspheres are nitrile rubber microspheres coated with ethylene-vinyl acetate copolymer; The porous sound-insulating mineral particles are prepared by the following method: A. Soak expanded perlite particles in a silane coupling agent-ethanol solution for 2-3 hours, filter, and dry at 60-80℃ to obtain active expanded perlite. B. Mix diatomaceous earth with nano-titanium dioxide sol, sonicate for 30-40 minutes, and then dry at 120-150℃ to obtain photocatalytically modified diatomaceous earth; C. Mix activated expanded perlite and photocatalytic modified diatomite, add water-based epoxy resin emulsion, and press under 15-20 MPa pressure to obtain composite mineral particles. D. The composite mineral particles are first calcined at 300-400℃ for 1-2 hours, then heated to 700-800℃ and calcined for 2-3 hours. After natural cooling, porous sound-insulating mineral particles are obtained.

2. The paper-faced gypsum board according to claim 1, characterized in that: The modified elastic microspheres were prepared by the following method: (1) Add nitrile rubber microspheres to deionized water and stir at 600-800 r / min for 30-50 min to form a dispersion; (2) After mixing ethylene-vinyl acetate copolymer with deionized water, heat the mixture to 60-70℃, add dioctyl phthalate and stir for 20-30 min to obtain the coating solution; (3) Add the coating solution to the dispersion at a rate of 1-2 mL / min, heat to 75-85℃ and stir at 800-1000 r / min. After the addition is complete, add ammonium persulfate, keep warm and stir for 2-3 hours, cool down and let stand, then centrifuge to separate, and obtain modified elastic microspheres after washing and drying.

3. The paper-faced gypsum board according to claim 2, characterized in that: In step (1), the mass ratio of nitrile rubber microspheres to deionized water is 1:(15-25).

4. A paper-faced gypsum board according to claim 2, characterized in that: In step (2), the mass ratio of ethylene-vinyl acetate copolymer to deionized water is 1:(4-8), and the amount of dioctyl phthalate added is 10%-20% of the ethylene-vinyl acetate copolymer.

5. A paper-faced gypsum board according to claim 2, characterized in that: In step (3), the mass ratio of coating solution to dispersion is 1:(3-5); the amount of ammonium persulfate added is 0.5%-1% of the total mass of coating solution and dispersion.

6. A paper-faced gypsum board according to claim 1, characterized in that: In step A, the mass fraction of silane coupling agent in the silane coupling agent-ethanol solution is 5%-8%; the mass ratio of expanded perlite particles to silane coupling agent-ethanol solution is 1:(8-12).

7. A paper-faced gypsum board according to claim 1, characterized in that: In step B, the mass concentration of the nano-titanium dioxide sol is 3%-5%; the mass ratio of the diatomaceous earth to the nano-titanium dioxide sol is 10:(1-2).

8. A paper-faced gypsum board according to claim 1, characterized in that: In step C, the mass ratio of activated expanded perlite to photocatalytic modified diatomite is (3-5):1; the amount of waterborne epoxy resin emulsion added accounts for 2%-4% of the total mass of activated expanded perlite and photocatalytic modified diatomite.

9. A production process for paper-faced gypsum board according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Mix gypsum clinker, vermiculite powder, talc powder, and water-reducing agent and stir for 10-20 minutes. Then add modified elastic microspheres and porous sound-insulating mineral particles and stir for 6-10 minutes. Then add glass fiber, silica aerogel particles, aluminum hydroxide micro powder, acrylic emulsion, and water and stir for 30-50 minutes to obtain gypsum slurry. S2. Lay the facing paper on the upper and lower conveyor belts of the molding machine, pour the gypsum slurry from step S1 evenly onto the lower facing paper, cover it with the upper facing paper, and extrude it through the extrusion rollers to form it. Control the molding pressure to 0.4-0.6MPa to obtain the gypsum board blank. Place the gypsum board blank in a pre-curing chamber at 45-55℃ for 1.5-2.5h, and then transfer it to a drying kiln at 130-150℃ for 5-7h to obtain paper-faced gypsum board.

Images