Phosphogypsum anti-glare panel and preparation method thereof

Abstract

The invention discloses an ardealite anti-glare panel and a preparation method thereof, and relates to the technical field of bridges. The specific preparation method comprises the following steps: drying type II anhydrite to obtain dried type II anhydrite, sequentially adding stearic acid and acrylic resin into the dried type II anhydrite, and mixing to obtain a mixed material; adding polyvinyl chloride resin, polyethylene wax, chlorinated polyethylene, an impact modifier, titanium dioxide, a compound stabilizer, a fiber mixture, an antioxidant and a light stabilizer into the mixed material, heating, stirring and mixing, and then cooling to obtain a premix; the premix is subjected to extrusion molding and then cooled, and the phosphogypsum anti-glare panel is obtained. The anti-glare panel is prepared in an extrusion molding mode, comprehensive recycling of ardealite is achieved, the prepared anti-glare panel is of a hollow structure, a steel wire or a steel plate can be added into the hollow cavity to improve the strength of the anti-glare panel, and the anti-glare panel can cope with the working condition of large wind power.

Description

Technical Field

[0001] This invention relates to a phosphogypsum anti-glare board and its preparation method, belonging to the field of bridge technology. Background Technology

[0002] Phosphogypsum is a solid waste generated by the phosphate chemical industry. The amount of phosphogypsum in China and the amount of newly added phosphogypsum each year are huge. The comprehensive utilization of phosphogypsum has attracted much attention. Promoting the comprehensive utilization of phosphogypsum can help reduce the environmental pollution risk caused by phosphogypsum stockpiling. However, the existing comprehensive utilization of phosphogypsum in China is based on low-value and low-cost utilization methods, such as mine backfilling, ecological restoration, roadbed paving, and stone building materials. Due to the high transportation costs, these utilization methods are difficult to achieve cross-regional utilization.

[0003] Therefore, a new approach to the comprehensive utilization of phosphogypsum—high-value comprehensive utilization of phosphogypsum—is proposed. This involves combining phosphogypsum with high-value materials to enhance its value. Based on this concept, this invention proposes a phosphogypsum anti-glare board and its preparation method, achieving high-value comprehensive utilization of phosphogypsum. This is achieved by combining type II anhydrous phosphogypsum obtained through purification with resin, fiber, and various modifying agents to synergistically achieve functional transformation. However, phosphogypsum has poor bonding ability with resin and fiber, and its low stability and poor flowability lead to processing difficulties and challenges in continuous production.

[0004] Currently, most anti-glare panels are made of fiberglass, which is brittle and prone to powdering, fading, and breakage when exposed to the outdoors for a long time. Some anti-glare panels are blow-molded hollow anti-glare panels, which have a closed cavity structure and have extremely high toughness and are resistant to breakage, but their strength is insufficient. They are prone to softening and deformation and losing their anti-glare ability when exposed to the sun for a long time. Therefore, the relevant technologies have defects and shortcomings and need to be further improved and developed. Summary of the Invention

[0005] To address the shortcomings of related technologies, this invention provides a phosphogypsum anti-glare board and its preparation method. This phosphogypsum anti-glare board possesses advantages such as excellent ductility, low cost, and superior impact resistance, solving the problems of poor toughness, easy breakage, and insufficient weather resistance of fiberglass anti-glare boards. The phosphogypsum-based raw material described in this invention specifically refers to type II anhydrous gypsum obtained from industrial by-product phosphogypsum through purification, calcination, or crystallization processes. This material retains the main component of phosphogypsum (calcium sulfate) while overcoming its defects of poor fluidity and instability, making it suitable for composite with polymer resins.

[0006] One of the objectives of this invention is to provide a phosphogypsum anti-glare board, wherein the raw material composition of the phosphogypsum anti-glare board comprises, by weight: 95-115 parts of polyvinyl chloride resin, 95-115 parts of type II anhydrous gypsum, 1-3 parts of stearic acid, 1-3 parts of polyethylene wax, 10-15 parts of chlorinated polyethylene, 5-10 parts of acrylic resin, 10-12 parts of impact modifier, 3-6 parts of titanium dioxide, 10-15 parts of composite stabilizer, 20-30 parts of fiber mixture, 1-3 parts of antioxidant, and 1-3 parts of light stabilizer. The phosphogypsum anti-glare board has a double-layer hollow structure.

[0007] Preferably, the anhydrous gypsum of type II has a mesh size of 800-1200; the fiber mixture is a fiber mixture formed by mixing glass fiber and wood fiber or a fiber mixture formed by mixing basalt fiber and wood fiber; the impact modifier is one or more of the following: ethylene-octene copolymer grafted with maleic anhydride POE-g-MAH, acrylate impact modifier ACR-ZB-401, and ethylene propylene diene monomer (EPDM); the composite stabilizer is a calcium-zinc composite stabilizer; the antioxidant is a composite antioxidant of Irganox 1076 and Irgafos 168; and the light stabilizer is one or more of the following: light stabilizer 770, light stabilizer 622, and light stabilizer 119.

[0008] The second objective of this invention is to provide a method for preparing a phosphogypsum anti-glare board, specifically including the following steps: (1) Dry the type II anhydrous gypsum to obtain the dried type II anhydrous gypsum. First, add stearic acid to the dried type II anhydrous gypsum and mix. Then add acrylic resin and mix to obtain a mixture.

[0009] (2) Add polyvinyl chloride resin, polyethylene wax, chlorinated polyethylene, impact modifier, titanium dioxide, composite stabilizer, fiber mixture, antioxidant and light stabilizer to the mixture, heat and stir to mix, and then cool to obtain premix.

[0010] (3) The premixed material is extruded (preferably a twin-screw extruder is used as the extrusion device), and then cooled to obtain phosphogypsum anti-glare board.

[0011] Preferably, the drying conditions in step (1) are: drying at 60-100℃ for 30-60 minutes.

[0012] Preferably, the conditions for adding stearic acid in step (1) are: stirring and mixing at 100-300 rpm for 5-20 minutes at 60-100℃; the conditions for adding acrylic resin are: stirring and mixing at 100-300 rpm for 5-20 minutes at 60-100℃.

[0013] Preferably, the heating and stirring conditions in step (2) are: stirring and mixing at 3000-6000 rpm for 20-30 minutes at 105-110℃.

[0014] Preferably, the temperature of the extrusion melting section in step (3) is 175-190℃ and the die head pressure is 10-20MPa.

[0015] Mechanism of the invention: This invention uses the solid product from the wet process of producing phosphoric acid from phosphate rock to prepare type II anhydrous gypsum, and introduces resin, fiber, and various modifying agents. The anti-glare board is prepared by extrusion. Through the synergistic effect of the anti-glare board raw materials and extrusion technology, this invention achieves a stable combination of phosphogypsum, resin, and fiber, enabling the continuous production of high-strength, antioxidant phosphogypsum anti-glare boards.

[0016] The beneficial effects of this invention are: (1) Green and environmentally friendly: This invention uses Type II anhydrous gypsum, which is obtained by deep processing of industrial phosphogypsum, as the main inorganic filler. Through the synergistic effect of anti-glare board raw materials and extrusion technology, it achieves a high-strength combination of Type II anhydrous gypsum with resin and fiber, overcomes the problems of low stability and poor fluidity of original phosphogypsum, realizes the high-value comprehensive utilization of phosphogypsum, increases the rigidity and strength of the product, and realizes continuous production.

[0017] (2) Energy saving and consumption reduction: The present invention uses type II anhydrous gypsum to prepare anti-glare board. This material absorbs heat quickly, dissipates heat quickly, and has a short high-pressure heat preservation and curing time, which greatly improves production efficiency.

[0018] (3) Antioxidant: The present invention uses type II anhydrous gypsum to prepare anti-glare board, whose main component is calcium sulfate, which has stronger corrosion resistance than traditional inorganic fillers and can effectively extend the service life of the product.

[0019] (4) Crack resistance: Phosphogypsum is a single-phase material with small hardening and temperature deformation. The product does not have hollow areas or cracks. The surface is free of peeling, cracks, and pinholes. The overall molding is complete and without obvious skewing.

[0020] (5) Self-cleaning performance: The surface of the phosphogypsum anti-glare board is smooth, with rounded edges, no burrs, and no flash; it can be self-cleaned by rainwater and leaves no dust residue.

[0021] (6) Split design: It consists of an anti-glare panel and a base. If the anti-glare panel is damaged, only the anti-glare panel needs to be replaced, saving maintenance costs.

[0022] (7) Special formula: strong weather resistance, anti-corrosion and anti-oxidation, service life of 10-15 years.

[0023] (8) Recyclable: The main materials are all recyclable materials, which can be directly recycled for secondary processing. The recycling is easy and efficient, and can be recycled at half price.

[0024] (9) Unique Structure: The phosphogypsum anti-glare board of this invention is designed as a double-layer hollow structure with a 1.2mm reinforced inner steel plate slot reserved in the middle. The finished board is 6.2mm thick, with a single-layer wall thickness of 2.5mm, a width of 200mm, and a height of 600~1000mm. The size can be customized, and the overall shape can be designed as an inverted S (e.g., Figure 1 (As shown) or straight surface; the finished phosphogypsum anti-glare board has a single-layer wall thickness of 2.5mm, which can meet the requirements of laser engraving process for customized surface texture engraving, or film coating process; the phosphogypsum anti-glare board base of this invention is formed in one piece, and the three-dimensional view of the base is shown. Figure 2 As shown, stainless steel bolts are used to fix the anti-glare panel to the base, and expansion bolts are used to fix the base to the crash barrier. The phosphogypsum anti-glare panel of this invention adopts a double-layer hollow structure, and steel plates can be added inside the hollow structure to enhance the strength of the anti-glare panel and cope with greater wind conditions. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the inverted S-shaped cross-section of the phosphogypsum anti-glare board prepared according to the present invention.

[0026] Figure 2 This is a perspective view of the inverted S-shaped base of the phosphogypsum anti-glare plate prepared according to the present invention. Detailed Implementation

[0027] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this invention are all commercially available products. The type II anhydrous gypsum used in the embodiments of this invention refers to the solid product generated from the wet process of producing phosphoric acid from phosphate rock, prepared by high-temperature calcination or crystal transformation of calcium sulfate dihydrate.

[0028] Example 1 A method for preparing a phosphogypsum anti-glare board specifically includes the following steps: The raw material composition of this embodiment, by weight, includes: 95 parts polyvinyl chloride resin, 115 parts type II anhydrous gypsum (800~1200 mesh), 3 parts stearic acid, 1 part polyethylene wax, 10 parts chlorinated polyethylene, 5 parts acrylic resin, 10 parts impact modifier, 6 parts titanium dioxide, 10 parts calcium zinc composite stabilizer, 20 parts fiber mixture, 3 parts antioxidant, and 3 parts light stabilizer. The impact modifier is a mixture of POE-g-MAH, ACR-ZB-401, and EPDM in a mass ratio of 1:1:1. The fiber mixture is a mixture of glass fiber and wood fiber in a mass ratio of 1:1. The antioxidant is a mixture of Irganox 1076 and Irgafos 168 in a mass ratio of 1:1. The light stabilizer is light stabilizer 770.

[0029] (1) Type II anhydrous gypsum (800~1200 mesh) was dried at 60°C for 60 min to obtain dried Type II anhydrous gypsum. Stearic acid was added to the dried Type II anhydrous gypsum and stirred at 300 rpm for 5 min at 60°C. Then acrylic resin was added and stirred at 300 rpm for 5 min at 60°C to obtain a mixture.

[0030] (2) Add polyvinyl chloride resin, polyethylene wax, chlorinated polyethylene, impact modifier, titanium dioxide, calcium zinc composite stabilizer, fiber mixture, antioxidant and light stabilizer to the mixture, and stir and mix at 4000 rpm for 20 min at 110℃, and then cool for 60 min to obtain the premix.

[0031] (3) The premixed material is placed in a twin-screw extruder and extruded at a melting temperature of 180°C and a die head pressure of 15MPa. After cooling, the phosphogypsum anti-glare board is obtained.

[0032] Example 2 A method for preparing a phosphogypsum anti-glare board specifically includes the following steps: The raw material composition of this embodiment, by weight, includes: 115 parts polyvinyl chloride resin, 95 parts type II anhydrous gypsum (800~1200 mesh), 1 part stearic acid, 3 parts polyethylene wax, 15 parts chlorinated polyethylene, 10 parts acrylic resin, 12 parts impact modifier, 3 parts titanium dioxide, 15 parts calcium-zinc composite stabilizer, 30 parts fiber mixture, 1 part antioxidant, and 1 part light stabilizer. The impact modifier is a mixture of POE-g-MAH and EPDM in a 1:1 mass ratio; the fiber mixture is a mixture of basalt fiber and wood fiber in a 2:1 mass ratio; the antioxidant is a mixture of Irganox 1076 and Irgafos 168 in a 1:2 mass ratio; and the light stabilizer is a mixture of light stabilizer 770, light stabilizer 622, and light stabilizer 119 in a 1:1:1 mass ratio.

[0033] (1) Type II anhydrous gypsum (800~1200 mesh) was dried at 100℃ for 30 min to obtain dried Type II anhydrous gypsum. Stearic acid was added to the dried Type II anhydrous gypsum and stirred at 100 rpm for 20 min at 100℃. Then acrylic resin was added and stirred at 100 rpm for 20 min at 100℃ to obtain a mixture.

[0034] (2) Add polyvinyl chloride resin, polyethylene wax, chlorinated polyethylene, impact modifier, titanium dioxide, calcium zinc composite stabilizer, fiber mixture, antioxidant and light stabilizer to the mixture, and stir and mix at 6000 rpm for 30 min at 105℃, and then cool for 120 min to obtain the premix.

[0035] (3) The premixed material is placed in a twin-screw extruder and extruded at a melting temperature of 175°C and a die head pressure of 10 MPa. After cooling, the phosphogypsum anti-glare board is obtained.

[0036] Example 3 A method for preparing a phosphogypsum anti-glare board specifically includes the following steps: The raw material composition of this embodiment, by weight, includes: 100 parts polyvinyl chloride resin, 100 parts type II anhydrous gypsum (800~1200 mesh), 2 parts stearic acid, 2 parts polyethylene wax, 12 parts chlorinated polyethylene, 8 parts acrylic resin, 11 parts impact modifier, 4 parts titanium dioxide, 12 parts calcium zinc composite stabilizer, 25 parts fiber mixture, 2 parts antioxidant, and 2 parts light stabilizer. The impact modifier is ACR-ZB-401. The fiber mixture is a mixture of glass fiber and wood fiber in a mass ratio of 1:2. The antioxidant is a mixture of Irganox 1076 and Irgafos 168 in a mass ratio of 2:1. The light stabilizer is a mixture of light stabilizer 770 and light stabilizer 119 in a mass ratio of 1:1.

[0037] (1) Type II anhydrous gypsum (800~1200 mesh) was dried at 80°C for 50 min to obtain dried Type II anhydrous gypsum. Stearic acid was added to the dried Type II anhydrous gypsum and stirred at 250 rpm for 10 min at 80°C. Then acrylic resin was added and stirred at 250 rpm for 10 min at 80°C to obtain a mixture.

[0038] (2) Add polyvinyl chloride resin, polyethylene wax, chlorinated polyethylene, impact modifier, titanium dioxide, calcium zinc composite stabilizer, fiber mixture, antioxidant and light stabilizer to the mixture, and stir and mix at 3000 rpm for 25 min at 107℃, and then cool for 100 min to obtain the premix.

[0039] (3) The premixed material is placed in a twin-screw extruder and extruded at a melting temperature of 190°C and a die head pressure of 20 MPa. After cooling, the phosphogypsum anti-glare board is obtained.

[0040] Comparative Example 1 A method for preparing a fiberglass anti-glare panel specifically includes the following steps: (1) Clean and demold the mold. Preheat the fiberglass mold at 40°C for 30 minutes, then spray polyvinyl alcohol release agent evenly and dry at 40°C for 20 minutes to obtain the pretreated mold.

[0041] (2) In the pretreated mold cavity, 30g / m 2 One layer of glass fiber surface mat, 450g / m 2 Three layers of chopped strand mat are used, with fiberglass reinforcing ribs pre-placed in key stress areas to obtain a reinforced material preform.

[0042] (3) Lay porous release cloth and resin guide net on the reinforcing material preform in sequence, and arrange resin injection pipe and vacuum extraction pipe. Then use vacuum bag film to completely seal it, maintain it at a vacuum degree of -0.095MPa for 10 minutes, check the integrity of the seal, and obtain the vacuum injection system.

[0043] (4) The unsaturated polyester resin, methyl ethyl ketone peroxide and cobalt isooctanoate solution are mixed at 200 rpm for 5 min at 25°C in a weight ratio of 100:1.2:1.5 to obtain the resin solution.

[0044] (5) Under a vacuum of -0.09MPa, the resin solution is introduced into the vacuum injection system through the injection pipe for 15 minutes. After the resin is filled, the vacuum pressure is maintained for 120 minutes to obtain a pre-cured fiberglass anti-glare plate blank.

[0045] (6) The fiberglass anti-glare plate blank and the mold are cured at 60°C for 60 minutes, then demolded, and after edge trimming, grinding and drilling, the fiberglass anti-glare plate is obtained.

[0046] The performance of the phosphogypsum anti-glare board prepared in the embodiments of the present invention and the fiberglass anti-glare board prepared in Comparative Example 1 were tested and compared. The comparison results are shown in Table 1. Table 1 Comparative analysis reveals that the embodiments of this invention use phosphogypsum as a raw material, achieving high-strength bonding with resin, fiber, and various modifying agents. The phosphogypsum anti-glare board is synergistically prepared through extrusion. The preparation method of these embodiments achieves low-defect, impurity-free production of the anti-glare board, which exhibits excellent ductility, flame retardancy, and oxidation resistance, and has a long service life. Due to the use of hollow extrusion, the phosphogypsum anti-glare board prepared in these embodiments has double-layer protection and excellent impact resistance. The recycling method for this phosphogypsum anti-glare board is low-energy, efficient, simple, and more environmentally friendly. In contrast, the fiberglass anti-glare board prepared in the comparative example has numerous burrs and impurities on its surface, a fixed color that cannot be customized, weak impact resistance due to its single-layer structure, heavy material, poor toughness, and low flame retardancy; toxic during production and installation; non-recyclable; high cost; prone to fading; and short service life, exhibiting numerous defects in practical applications.

[0047] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A phosphogypsum anti-glare board, characterized in that, The raw material composition of the phosphogypsum anti-glare board, by weight, includes: 95-115 parts of polyvinyl chloride resin, 95-115 parts of type II anhydrous gypsum, 1-3 parts of stearic acid, 1-3 parts of polyethylene wax, 10-15 parts of chlorinated polyethylene, 5-10 parts of acrylic resin, 10-12 parts of impact modifier, 3-6 parts of titanium dioxide, 10-15 parts of composite stabilizer, 20-30 parts of fiber mixture, 1-3 parts of antioxidant, and 1-3 parts of light stabilizer; the phosphogypsum anti-glare board has a double-layer hollow structure.

2. The phosphogypsum anti-glare board according to claim 1, characterized in that, The anhydrous gypsum of type II has a mesh size of 800-1200 mesh; the fiber mixture is a fiber mixture formed by mixing glass fiber and wood fiber in any proportion or a fiber mixture formed by mixing basalt fiber and wood fiber in any proportion; the impact modifier is one or more of the following: ethylene-octene copolymer grafted with maleic anhydride POE-g-MAH, acrylate impact modifier ACR-ZB-401, and ethylene propylene diene monomer (EPDM); the composite stabilizer is a calcium-zinc composite stabilizer; the antioxidant is a composite antioxidant of Irganox 1076 and Irgafos 168; and the light stabilizer is one or more of the following: light stabilizer 770, light stabilizer 622, and light stabilizer 119.

3. The method for preparing the phosphogypsum anti-glare board according to claim 1, characterized in that, Specifically, the following steps are included: (1) Dry the type II anhydrous gypsum to obtain the dried type II anhydrous gypsum. First, add stearic acid to the dried type II anhydrous gypsum and mix. Then add acrylic resin and mix to obtain a mixture. (2) Add polyvinyl chloride resin, polyethylene wax, chlorinated polyethylene, impact modifier, titanium dioxide, composite stabilizer, fiber mixture, antioxidant and light stabilizer to the mixture, heat and stir to mix, and then cool to obtain premix; (3) The premixed material is extruded and then cooled to obtain phosphogypsum anti-glare board.

4. The method for preparing the phosphogypsum anti-glare board according to claim 3, characterized in that, The drying conditions in step (1) are: drying at 60-100℃ for 30-60 minutes.

5. The method for preparing the phosphogypsum anti-glare board according to claim 3, characterized in that, The conditions for adding stearic acid in step (1) are: stirring and mixing at 100-300 rpm for 5-20 minutes at 60-100℃; the conditions for adding acrylic resin are: stirring and mixing at 100-300 rpm for 5-20 minutes at 60-100℃.

6. The method for preparing the phosphogypsum anti-glare board according to claim 3, characterized in that, The conditions for heating and stirring in step (2) are: stirring and mixing at 3000-6000 rpm for 20-30 minutes at 105-110℃.

7. The method for preparing the phosphogypsum anti-glare board according to claim 3, characterized in that, In step (3), the temperature of the extrusion melting section is 175-190℃ and the pressure of the die head is 10-20MPa.

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