A semi-dry process gypsum fiberboard substrate composite reinforcing agent, and a preparation method and application thereof

Abstract

The application discloses a semi-dry process gypsum fiberboard substrate composite reinforcing agent and a preparation method and application thereof. The semi-dry process gypsum fiberboard substrate composite reinforcing agent comprises, in mass parts, 5-12 parts of styrene-acrylate redispersible emulsion powder, 3-8 parts of 24-88 type polyvinyl alcohol and 8-18 parts of reinforcing fiber. The application adopts a ternary core compounding system of styrene-acrylate redispersible emulsion powder, 24-88 type polyvinyl alcohol and reinforcing fiber, matches various functional auxiliary materials, accurately adapts to the production conditions of semi-dry process, low moisture, high-pressure forming and gradient drying, realizes the integration of interface toughening, interlayer bonding and skeleton reinforcement, and comprehensively improves the comprehensive performance of gypsum fiberboard under the premise of controlling production cost.

Description

Technical Field

[0001] This application relates to the field of functional additives for inorganic building materials and the technology of material preparation, and in particular to a semi-dry gypsum fiberboard substrate composite reinforcing agent, its preparation method and application. Background Technology

[0002] Gypsum fiberboard is a green and environmentally friendly building material that uses building gypsum as the cementitious matrix and plant fibers as the reinforcement. It has advantages such as fire resistance, sound insulation, heat insulation, easy processing, low carbon emissions, and no pollution. It is widely used in building decoration, home decoration, commercial decoration, and the laminate flooring industry. At present, the mainstream production processes of gypsum fiberboard are divided into wet process and semi-dry process. Among them, the semi-dry process adopts a production mode of low water ratio, semi-dry material mixing, high pressure molding, and gradient drying. Compared with the traditional wet process, the drying energy consumption is lower, the board density is more uniform, the internal pores are fewer, and the overall structural strength is higher. It has now become the mainstream mass production process in the industry.

[0003] Existing semi-dry gypsum fiber reinforcing agents have several technical defects. Multiple batches of standardized experiments have verified the following specific problems: First, traditional wet-process latex powders and fiber-based additives have poor compatibility. In a semi-dry 70% low-moisture system, the powder and fiber are prone to agglomeration and clumping, significantly reducing the uniformity of material mixing. Simultaneously, insufficient hydration of the latex powder prevents the formation of a continuous adhesive film during high-temperature drying, resulting in weak interfacial bonding between the fiber and the gypsum matrix, leading to delamination and cracking in the finished boards. Second, while single 24-88 type polyvinyl alcohol (PVA) can improve the breaking load, static bending strength, internal bond strength, and nail-holding force of the board, this material relies solely on interfacial adhesion and cannot improve the core hardness and puncture resistance. Furthermore, when the addition amount reaches 3% or higher, many mechanical properties of the board show a decline, and the shear force value is abnormal, posing risks to production and testing. Third, single styrene-acrylate redispersible latex powder has excellent high-temperature film-forming properties and can improve the toughness of the board, but it lacks rigid skeletal support, resulting in insufficient impact and deformation resistance. Fourth, in single-fiber reinforced systems, the wettability between fibers and semi-dry gypsum materials is poor, and there are numerous micropores at the interface, limiting the reinforcing effect of simple reinforcement. Fifth, other types of additives have significant drawbacks: SBR styrene-butadiene rubber powder has weak reinforcing effect and high raw material costs; dispersed plant gums have a significant retarding effect and are prone to adhering to conveyor belts during production; PVAC polyvinyl acetate requires an extremely long drying cycle and cannot be adapted to semi-dry gradient drying conditions.

[0004] At present, there is no latex powder-fiber composite reinforcement system specifically designed for semi-dry process conditions. Traditional additives cannot solve multiple problems such as material dispersion, interface bonding, skeleton reinforcement, coagulation control, and water resistance stability at the same time, resulting in inconsistent quality of semi-dry gypsum fiberboard products.

[0005] Therefore, developing a specialized composite reinforcing agent that is compatible with semi-dry processes and has excellent overall performance is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0006] In view of this, this application provides a semi-dry gypsum fiberboard substrate composite reinforcing agent, which comprehensively improves the overall performance of gypsum fiberboard while controlling production costs.

[0007] This application provides a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising, by weight parts: 5 to 12 parts of styrene-acrylate redispersible latex powder, 3 to 8 parts of type 24-88 polyvinyl alcohol, and 8 to 18 parts of reinforcing fiber.

[0008] In some specific implementations, the particle size of the styrene-acrylate redispersible latex powder is 90 mesh to 120 mesh; And / or, the melt film-forming temperature of the styrene-acrylate redispersible latex powder is 110°C to 130°C.

[0009] In some specific implementations, the degree of polymerization of the 24-88 type polyvinyl alcohol is 2000 to 3000; And / or, the degree of alcoholysis of the 24-88 type polyvinyl alcohol is 80 to 90.

[0010] In some specific implementations, the reinforcing fiber includes chopped inorganic fibers; The chopped inorganic fibers are one or both of chopped glass fibers and chopped basalt fibers.

[0011] In some specific implementations, the length of the reinforcing fiber is 4 mm to 10 mm; And / or, the diameter of the reinforcing fiber is from 7 μm to 20 μm.

[0012] In some specific implementations, the following components are also included by weight: 1 to 3 parts of gypsum accelerator; The gypsum accelerator is a gypsum seed crystal; the initial setting time of the gypsum is 3 to 6 minutes, and the final setting time is 6 to 9 minutes.

[0013] In some specific implementations, the mixture also includes 0.5 to 3 parts by weight of a hydrophobic agent; The hydrophobic agent includes one or both of hydrogen-containing silicone oil and potassium methylsilicate.

[0014] This application also provides a method for preparing a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising: Styrene-acrylate redispersible latex powder, type 24-88 polyvinyl alcohol and reinforcing fibers are mixed, atomized and modified and sieved to obtain a semi-dry gypsum fiberboard substrate composite reinforcing agent.

[0015] In some specific implementations, the styrene-acrylate redispersible latex powder, type 24-88 polyvinyl alcohol, and reinforcing fibers are each initially screened independently and then mixed. The initial screening is performed using an 80-mesh sieve. And / or, the mixture comprises styrene-acrylate redispersible latex powder, 24-88 type polyvinyl alcohol stirred at 200 r / min to 250 r / min for 4 min to 6 min, and reinforcing fibers added and stirred at 700 r / min to 800 r / min for 8 min to 12 min; And / or, the atomization modification includes adding an organosilicon hydrophobic agent and stirring for 2 to 5 minutes under a pressure of 0.2 MPa to 0.4 MPa; And / or, the sieving is performed using a 90-mesh to 100-mesh sieve.

[0016] This application also provides a gypsum fiberboard comprising, by weight, 82 parts of building gypsum, 15 to 20 parts of virgin paper fiber and 1 to 2 parts of semi-dry gypsum fiberboard substrate composite reinforcing agent. The semi-dry gypsum fiberboard substrate composite reinforcing agent is the semi-dry gypsum fiberboard substrate composite reinforcing agent as described above or the semi-dry gypsum fiberboard substrate composite reinforcing agent prepared according to the preparation method described above.

[0017] This application uses styrene-acrylate redispersible latex powder, 24-88 type polyvinyl alcohol, and reinforcing fiber as a ternary core compound system, combined with a variety of functional auxiliary materials, to precisely adapt to the semi-dry low moisture, high pressure molding, and gradient drying production conditions, so as to achieve integrated interface toughening, interlayer bonding, and skeleton reinforcement, and comprehensively improve the overall performance of gypsum fiberboard while controlling production costs.

[0018] High adaptability to working conditions: All components are compatible with gradient drying process, and the film-forming and bonding effect of latex powder and polyvinyl alcohol is stable, without the need to modify the existing semi-dry production line. Excellent overall performance: The ternary core components work synergistically to balance interfacial toughness, interlayer bonding, and skeleton strength, resulting in a 30% or more increase in the breaking load, static bending strength, and internal bond strength of the board compared to the blank group; at the same time, it makes up for the deficiency of insufficient hardness of single polyvinyl alcohol core and does not have the problem of abnormal mechanical data with high dosage. High production stability: The compound gypsum accelerator precisely controls the gypsum setting time, completely solving production problems such as slow setting and belt sticking of traditional plant glue, and can meet the requirements of continuous mass production. Good water resistance and dimensional stability: The silicone hydrophobic agent significantly reduces the water absorption rate of the board, making the board less prone to warping and cracking under dry and wet cycles and high and low temperature environments, effectively extending its service life; Excellent cost performance: All raw materials used are common chemical products on the market, making procurement convenient; the optimal dosage is 1% to 2%, and the additional cost per unit area is controllable, far lower than high-cost additives such as SBR and PVAC, making it suitable for large-scale industrial promotion. Wide range of applications: It can produce gypsum fiberboard with different thicknesses from 8 to 30 mm, which can be used as a special substrate for reinforced flooring, as well as for building partitions, furniture boards and other applications. Detailed Implementation

[0019] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0020] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0021] It should be understood that the order of steps or the sequence of actions is not important as long as this application remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0022] The use of any and all instances or exemplary language such as “e.g.” or “include” in this document is intended merely to better illustrate the application and does not constitute a limitation on the scope of the application. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of this application.

[0023] Furthermore, the numerical ranges and parameters used to define this application are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise explicitly stated, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately." Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0024] The purpose of this application is to overcome the shortcomings of existing technologies, such as the unsuitability of wet-process reinforcing agents for semi-dry processes, the significant performance limitations of single additives, and the problems of traditional additives such as retarding, belt adhesion, and abnormal mechanical data at high dosages. This application provides a composite reinforcing agent for semi-dry gypsum fiberboard substrates. This application uses styrene-acrylate redispersible latex powder, 24-88 type polyvinyl alcohol, and composite fibers as a ternary core compounding system, combined with various functional additives. It precisely adapts to the production conditions of semi-dry processes, including low moisture content, high-pressure molding, and gradient drying, achieving integrated interface toughening, interlayer bonding, and skeletal reinforcement. This comprehensively improves the overall performance of gypsum fiberboard while controlling production costs.

[0025] This application provides a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising, by weight parts: 5 to 12 parts of styrene-acrylate redispersible latex powder, 3 to 8 parts of type 24-88 polyvinyl alcohol, and 8 to 18 parts of reinforcing fiber.

[0026] The semi-dry gypsum fiberboard substrate composite reinforcing agent described in this application includes styrene-acrylate redispersible latex powder. In some specific implementations, the particle size of the styrene-acrylate redispersible latex powder is 90 mesh to 120 mesh, preferably 100 mesh to 120 mesh; the melt film-forming temperature of the styrene-acrylate redispersible latex powder is 110°C to 130°C, preferably 110°C. Its function is to form a continuous elastic film during the semi-dry gradient drying process, coating the fiber surface, eliminating micro-gaps at the interface between the fiber and the gypsum matrix, improving interfacial adhesion and board toughness, and mitigating the inherent brittleness of the gypsum matrix. The mass fraction of the styrene-acrylate redispersible latex powder is 5 parts to 12 parts, specifically 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, or 12 parts.

[0027] The semi-dry gypsum fiberboard substrate composite reinforcing agent described in this application includes type 24-88 polyvinyl alcohol. In some specific implementations, the degree of polymerization of the type 24-88 polyvinyl alcohol is 2000 to 3000, preferably 3000; the degree of alcoholysis of the type 24-88 polyvinyl alcohol is 80 to 90, preferably 80. Its function is to form an adhesive film after dissolving in water, strengthening the bonding strength between gypsum particles, and significantly improving the breaking load, static bending strength, internal bond strength, and nail-holding force of the board. This application strictly controls its dosage to avoid performance degradation and data anomalies caused by high dosage. The mass fraction of the type 24-88 polyvinyl alcohol is 3 to 8 parts, which can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, or 8 parts.

[0028] The semi-dry gypsum fiberboard substrate composite reinforcing agent described in this application includes reinforcing fibers. In some specific implementations, the reinforcing fibers include chopped inorganic fibers; the chopped inorganic fibers are one or both of chopped glass fibers and chopped basalt fibers. The length of the reinforcing fibers is 4 mm to 10 mm, preferably 6 mm; in some specific implementations, the diameter of the reinforcing fibers is 7 μm to 20 μm, preferably 10 μm. Its function is to form a three-dimensional mesh-like reinforcing skeleton inside the board blank, disperse external loads, and compensate for the shortcomings of polyvinyl alcohol in improving the core hardness and puncture resistance. The mass fraction of the reinforcing fibers is 8 to 18 parts, and can be 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 parts.

[0029] The semi-dry gypsum fiberboard substrate composite reinforcing agent described in this application includes a gypsum accelerator. In some specific implementations, the gypsum accelerator is a gypsum seed crystal; after adding the gypsum accelerator, the initial setting time of the gypsum is 3 to 6 minutes, and the final setting time is 6 to 9 minutes. Its function is to precisely control the gypsum setting time, completely eliminate the problem of slow setting, and prevent belt sticking during production. The mass fraction of the gypsum accelerator is 1 to 3 parts, specifically 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts.

[0030] The semi-dry gypsum fiberboard substrate composite reinforcing agent described in this application includes a hydrophobic agent. In some specific implementations, the hydrophobic agent includes hydrogen-containing silicone oil, potassium methylsilicate, etc., which functions to block the capillary channels of the board, reduce water absorption, and improve the dimensional stability and strength retention rate of the board in humid environments. The mass fraction of the hydrophobic agent is 0.5 to 3 parts, specifically 0.5, 1, 1.5, 2, 2.5, or 3 parts.

[0031] The semi-dry gypsum fiberboard substrate composite reinforcing agent described in this application is mainly used in the fields of reinforced flooring gypsum substrate, building interior partition boards, furniture boards, and prefabricated gypsum substrates.

[0032] This application also provides a method for preparing a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising: Styrene-acrylate redispersible latex powder, type 24-88 polyvinyl alcohol and reinforcing fibers are mixed, atomized and modified and sieved to obtain a semi-dry gypsum fiberboard substrate composite reinforcing agent.

[0033] Specifically, this application first separately screens the styrene-acrylate redispersible latex powder, type 24-88 polyvinyl alcohol, and reinforcing fibers using an 80-mesh sieve. The raw materials are weighed according to the formula and screened using an 80-mesh sieve to remove lumps and agglomerated particles, while the fibers are broken, dispersed, and homogenized.

[0034] This application involves adding gypsum accelerator, styrene-acrylate redispersible latex powder, and 24-88 type polyvinyl alcohol into a closed dry powder mixer, stirring at 200-250 rpm for 4-6 minutes, then adding reinforcing fibers and stirring at 700-800 rpm for 8-12 minutes to ensure the fibers do not clump and the powder does not separate. Atomization modification and sieving are then performed to obtain a semi-dry gypsum fiberboard substrate composite reinforcing agent. In some specific implementations, atomization modification involves spraying an organosilicon hydrophobic agent into the mixture under a pressure of 0.2-0.4 MPa, followed by continuous stirring for 2-5 minutes, preferably 3 minutes. In some specific implementations, sieving is performed using a 90-100 mesh sieve to remove trace amounts of agglomerates, followed by sealed packaging.

[0035] This application also provides a gypsum fiberboard comprising, by weight, 82 parts of building gypsum, 15 to 20 parts of virgin paper fiber and 1 to 2 parts of semi-dry gypsum fiberboard substrate composite reinforcing agent. The semi-dry gypsum fiberboard substrate composite reinforcing agent is the semi-dry gypsum fiberboard substrate composite reinforcing agent as described above or the semi-dry gypsum fiberboard substrate composite reinforcing agent prepared according to the preparation method described above.

[0036] (1) Ingredients: Based on the total mass of building gypsum, add 1% to 2% of the above-mentioned semi-dry gypsum fiberboard substrate composite reinforcing agent; the fixed ratio of substrate is 82% building gypsum and 18% virgin paper fiber; (2) Semi-dry mixing: Add water to the raw material system, control the water-gypsum ratio to 70%, spray water at room temperature, and obtain a uniform semi-dry blank; (3) High pressure molding: After the blank is laid out, press the blank to a thickness of the specified thickness under a pressure of 12 to 15 MPa; (4) Gradient drying: Dry the blank in a dryer at 180 to 210℃ for 50 minutes to achieve a moisture content of ≤0.8% and obtain the finished gypsum fiberboard; (5) Post-treatment: Sand the board, spray waterproofing agent, and cut it according to product requirements.

[0037] The present application is further illustrated below with reference to embodiments. The scope of protection of the present application is not limited to the following embodiments.

[0038] Example 1

[0039] This embodiment provides a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising, by weight parts: 7 parts styrene-acrylate redispersible latex powder (the particle size of the styrene-acrylate redispersible latex powder is 120 mesh; the melt film-forming temperature of the styrene-acrylate redispersible latex powder is 110℃), 4 parts 24-88 type polyvinyl alcohol (the degree of polymerization of the 24-88 type polyvinyl alcohol is 3000; the degree of alcoholysis of the 24-88 type polyvinyl alcohol is 80), 1 part 6 mm long and 10 μm diameter short glass fiber, 2 parts gypsum accelerator (seed crystal), and 1 part hydrophobic agent (hydrogen-containing silicone oil).

[0040] The preparation method includes: pre-treatment of raw materials through an 80-mesh sieve (initial sieving); low-speed stirring at 220 r / min for 5 min; high-speed stirring at 750 r / min for 9 min; spraying hydrophobic agent with atomized solution and stirring for 3 min; and sealing and packaging after sieving through a 90-mesh sieve.

[0041] Application method: Add the semi-dry gypsum fiberboard substrate composite reinforcing agent at 1.5% of the weight of building gypsum, and prepare gypsum fiberboard by semi-dry method: fiber content 18%, gypsum powder content 82%, water-gypsum ratio 70%, mixing time 30min, holding time 30min, pressure 10-15MPa, thickness set at 10mm, dry material is evenly spread, and after spraying molding water on the upper surface, it is pressed and molded by press.

[0042] Example 2

[0043] This embodiment provides a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising, by weight: 10 parts styrene-acrylate redispersible latex powder, 6 parts 24-88 type polyvinyl alcohol, 1 part chopped basalt fiber, 2.5 parts gypsum accelerator (seed crystal), and 1.8 parts hydrophobic agent (containing hydrosilicone oil). The parameters, preparation method, and application of the styrene-acrylate redispersible latex powder, 24-88 type polyvinyl alcohol, and chopped glass fiber are consistent with those in the previous embodiment.

[0044] Example 3

[0045] This embodiment provides a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising, by weight parts: 12 parts styrene-acrylate redispersible latex powder, 7 parts 24-88 type polyvinyl alcohol, 1 part chopped basalt fiber, 3 parts gypsum setting accelerator (seed crystal), and 2.5 parts hydrophobic agent (containing hydrosilicone oil). The parameters, preparation method, and application of the styrene-acrylate redispersible latex powder, 24-88 type polyvinyl alcohol, and chopped glass fiber are consistent with those in the previous embodiment.

[0046] Example 4

[0047] This embodiment provides a semi-dry gypsum fiberboard substrate composite reinforcing agent, comprising, by weight parts: 14 parts styrene-acrylate redispersible latex powder, 8 parts 24-88 type polyvinyl alcohol, 1 part chopped basalt fiber, 3 parts gypsum setting accelerator (seed crystal), and 2.5 parts hydrophobic agent (containing hydrosilicone oil). The parameters, preparation method, and application of the styrene-acrylate redispersible latex powder, 24-88 type polyvinyl alcohol, and chopped glass fiber are consistent with those in the previous embodiment.

[0048] Comparative Example 1

[0049] This comparative example provides a method for preparing gypsum fiberboard using a semi-dry method, which differs from Example 1 in that it does not include a semi-dry gypsum fiberboard composite reinforcing agent.

[0050] Comparative Example 2

[0051] This comparative example provides a method for preparing gypsum fiberboard using a semi-dry method. The difference from Example 1 is that the composite reinforcing agent of the semi-dry gypsum fiberboard is replaced with 1.5% of type 24-88 polyvinyl alcohol.

[0052] Comparative Example 3

[0053] This comparative example provides a method for preparing gypsum fiberboard using a semi-dry method. The difference from Example 1 is that the composite reinforcing agent of the semi-dry gypsum fiberboard is replaced with 1.5% styrene-acrylate redispersible latex powder.

[0054] Comparative Example 4

[0055] This comparative example provides a method for preparing gypsum fiberboard using a semi-dry method. The difference from Example 1 is that the composite reinforcing agent of the semi-dry gypsum fiberboard is replaced with 1.5% short-cut glass fibers with a length of 6 mm and a diameter of 10 μm.

[0056] Comparative Example 5

[0057] This comparative example provides a method for preparing gypsum fiberboard using a semi-dry method. The difference from Example 1 is that the composite reinforcing agent of the semi-dry gypsum fiberboard is replaced with 1.5% SBR styrene-butadiene rubber powder.

[0058] Comparative Example 6

[0059] This comparative example provides a method for preparing gypsum fiberboard using a semi-dry method. The difference from Example 1 is that the composite reinforcing agent of the semi-dry gypsum fiberboard is replaced with 1.5% HYM-2 dispersed plant adhesive powder.

[0060] Comparative Example 7

[0061] This comparative example provides a method for preparing gypsum fiberboard using a semi-dry method. The difference from Example 1 is that the composite reinforcing agent of the semi-dry gypsum fiberboard is replaced with a 1:1 mixture of 1.5% cold water-soluble partially hydrolyzed polyvinyl alcohol powder and ethylene-vinyl acetate copolymer.

[0062] The performance of gypsum fiberboard prepared by the semi-dry method provided in Examples 1-4 and Comparative Examples 1-7 was tested, and the test methods are as follows: Fracture load: As specified in JC / T 2702; Core hardness: As specified in JC / T 2702; Shear force: as specified in JC / T 2702; Static bending strength: As specified in Clause 4.7 of GB / T 17657-2022; Elastic modulus: As specified in Clause 4.7 of GB / T 17657-2022; Nail holding force: As specified in Clause 4.21 of GB / T 17657-2022; Internal bond strength: As specified in Clause 4.17 of GB / T 17657-2022; 24-hour water absorption rate: As specified in Clause 4.6 of GB / T 17657-2022; The test results are shown in Table 1.

[0063] Table 1

[0064] The test results in the table above show that the semi-dry gypsum fiberboard substrate composite reinforcing agent described in this application is uniformly dispersed in a semi-dry low-moisture system. There are no issues such as retardation or belt sticking during the production process. After gradient drying, the film formation and bonding effect of each component are stable. The mechanical properties and water resistance of the examples are comprehensively superior to the blank group and various single-agent groups, effectively solving the problems of insufficient hardness of single polyvinyl alcohol core, weak impact resistance of single adhesive powder, and poor interfacial bonding of pure fibers. At the same time, the component dosage is strictly controlled, and no abnormal shear force phenomenon occurs with high dosage. The overall product performance is stable, and the comprehensive cost-effectiveness is far higher than that of high-cost additives such as SBR and PVAC, demonstrating good industrial application value.

[0065] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and application concept of this application, should be included within the scope of protection of this application.

Claims

1. A semi-dry gypsum fiberboard substrate composite reinforcing agent, characterized in that, It comprises, by weight parts: 5 to 12 parts styrene-acrylate redispersible latex powder, 3 to 8 parts type 24-88 polyvinyl alcohol and 8 to 18 parts reinforcing fiber.

2. The semi-dry gypsum fiberboard substrate composite reinforcing agent according to claim 1, characterized in that, The particle size of the styrene-acrylate redispersible latex powder is 90 to 120 mesh. And / or, the melt film-forming temperature of the styrene-acrylate redispersible latex powder is 110°C to 130°C.

3. The semi-dry gypsum fiberboard substrate composite reinforcing agent according to claim 1, characterized in that, The degree of polymerization of the 24-88 type polyvinyl alcohol is 2000 to 3000; And / or, the degree of alcoholysis of the 24-88 type polyvinyl alcohol is 80 to 90.

4. The semi-dry gypsum fiberboard substrate composite reinforcing agent according to claim 1, characterized in that, The reinforcing fibers include chopped inorganic fibers; The chopped inorganic fibers are one or both of chopped glass fibers and chopped basalt fibers.

5. The semi-dry gypsum fiberboard substrate composite reinforcing agent according to claim 1, characterized in that, The length of the reinforcing fiber is 4 mm to 10 mm; And / or, the diameter of the reinforcing fiber is from 7 μm to 20 μm.

6. The semi-dry gypsum fiberboard substrate composite reinforcing agent according to claim 1, characterized in that, The semi-dry gypsum fiberboard substrate composite reinforcing agent further includes, by weight, 1 to 3 parts of gypsum accelerator; The gypsum accelerator is a gypsum seed crystal; the initial setting time of the gypsum is 3 to 6 minutes, and the final setting time is 6 to 9 minutes.

7. The semi-dry gypsum fiberboard substrate composite reinforcing agent according to claim 1, characterized in that, The semi-dry gypsum fiberboard substrate composite reinforcing agent also includes 0.5 to 3 parts of hydrophobic agent by weight. The hydrophobic agent includes one or both of hydrogen-containing silicone oil and potassium methylsilicate.

8. A method for preparing a semi-dry gypsum fiberboard substrate composite reinforcing agent, characterized in that, include: Styrene-acrylate redispersible latex powder, type 24-88 polyvinyl alcohol and reinforcing fibers are mixed, atomized and modified and sieved to obtain a semi-dry gypsum fiberboard substrate composite reinforcing agent.

9. The preparation method according to claim 8, characterized in that, The styrene-acrylate redispersible latex powder, type 24-88 polyvinyl alcohol, and reinforcing fibers are each initially screened independently, and then mixed. The initial screening is performed using an 80-mesh sieve. And / or, the mixture comprises styrene-acrylate redispersible latex powder, 24-88 type polyvinyl alcohol stirred at 200 r / min to 250 r / min for 4 min to 6 min, and reinforcing fibers added and stirred at 700 r / min to 800 r / min for 8 min to 12 min; And / or, the atomization modification includes adding an organosilicon hydrophobic agent and stirring for 2 to 5 minutes under a pressure of 0.2 MPa to 0.4 MPa; And / or, the sieving is performed using a 90-mesh to 100-mesh sieve.

10. A gypsum fiberboard, characterized in that, The composite reinforcing agent comprises, by weight, 82 parts building gypsum, 15 to 20 parts virgin paper fiber and 1 to 2 parts semi-dry gypsum fiberboard substrate; The semi-dry gypsum fiberboard substrate composite reinforcing agent is the semi-dry gypsum fiberboard substrate composite reinforcing agent as described in any one of claims 1 to 7, or the semi-dry gypsum fiberboard substrate composite reinforcing agent prepared according to the preparation method described in claim 8 or 9.

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