Bio-based phosphorus-containing intrinsic flame-retardant polyurethane carrier roller winding pipe body for coal mine

Abstract

The invention discloses a bio-based phosphorus-containing intrinsic flame-retardant polyurethane carrier roller winding pipe body for a coal mine, the pipe body is made of a continuous fiber reinforced flame-retardant antistatic polyurethane composite material, and the flame-retardant antistatic polyurethane composite material is composed of polyurethane resin and glass fiber; the polyurethane resin comprises a component A, a component B, bio-based phosphorus-containing polyol, a flame retardant and an antistatic agent, by introducing the bio-based phosphorus-containing polyol and a continuous fiber reinforcement technology and combining with an optimized winding process, the carrier roller pipe body with high strength, wear resistance, flame retardance and static electricity resistance is prepared.

Description

Technical Field

[0001] The invention belongs to the technical fields of idlers for coal mines and flame-retardant and antistatic composite materials, and relates to a bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding pipe body for coal mines. Background Art

[0002] Idlers are important components of belt conveyors and are widely used in the material transportation systems of industries such as coal mines, power plants, and ports. Their main function is to support the weight of the conveyor belt and the materials thereon, ensuring the smooth operation of the conveyor belt. There are various types and a large number of idlers, accounting for about 35% of the total cost of belt conveyors. Their performance directly affects the operation efficiency, maintenance cost, and service life of the conveyor. According to different materials, idlers can be divided into various types such as metal idlers, ceramic idlers, rubber idlers, and plastic idlers. Each type of idler has specific performance characteristics and applicable scenarios, but there are also certain limitations.

[0003] Metal idlers are commonly used in heavy-duty working conditions due to their high impact resistance and rigidity. However, metal idlers are prone to rust in humid or corrosive environments, and materials are easily adhered to their surfaces, resulting in increased running resistance and higher noise. In addition, metal idlers are prone to wear during long-term use, and the worn surface may cause tearing damage to the conveyor belt. Their anti-corrosion and sealing performance are also relatively poor, increasing the maintenance cost. Ceramic idlers have excellent insulation, wear resistance, and corrosion resistance, and are not easily adhered to materials, making them suitable for use in corrosive environments. However, the impact resistance of ceramic idlers is poor, and they are prone to fracture, limiting their application in high-impact occasions. Rubber idlers are light in weight and have good shock absorption effects, which can effectively reduce running noise. However, their friction coefficient is large, they are not corrosion-resistant, and they are prone to aging during long-term use, resulting in a short service life. Plastic idlers have the advantages of dust prevention, corrosion prevention, waterproofing, low power consumption, low noise, and small wear on the conveyor belt, and have a long service life. However, plastic idlers have poor rigidity, are difficult to withstand high-intensity loads, and have high production costs and expensive prices, limiting their wide promotion in industries such as coal mines.

[0004] With the continuous improvement of the requirements for coal mine safety production, the flame retardancy and antistatic performance of idler materials have become the focus of attention. The environment in coal mine shafts is complex, with flammable gases and dust. Idler materials must have excellent flame retardant performance to reduce the fire risk, and at the same time, good antistatic performance to prevent static electricity accumulation from causing sparks. Traditional plastic idlers meet these requirements to a certain extent, but the problems of insufficient strength and high cost have not been effectively solved. In addition, in the existing idler preparation process, the welding process generally has problems of low efficiency and unstable quality. Traditional manual welding or simple mechanical welding is difficult to ensure the uniformity and reliability of the weld, resulting in quality problems that are likely to occur during the use of idlers, affecting the overall performance and service life.

[0005] In recent years, the application of composite materials in the manufacture of idlers has gradually increased. For example, fiber-reinforced composite materials have attracted attention due to their high strength and wear resistance. However, their preparation process is complex and the cost is relatively high, making it difficult to promote on a large scale. The introduction of flame retardants can improve the flame retardant properties of materials. However, traditional flame retardants may cause environmental pollution and have poor compatibility with matrix materials, affecting the mechanical properties of materials. Bio-based materials have become a research hotspot due to their renewable and environmentally friendly characteristics, but their application in flame-retardant polyurethane composite materials is still in the exploratory stage. Phosphorus-containing flame retardants have been widely studied due to their high-efficiency flame retardant properties. However, their combination in bio-based materials and application in the winding tube body of idlers still face technical challenges. In addition, the existing winding process has deficiencies in aspects such as fiber angle control, resin infiltration uniformity, and curing process optimization, resulting in unstable performance of the prepared idler tube body and difficulty in meeting the requirements of high strength and high durability in coal mines.

[0006] In summary, there are many deficiencies in the existing idler materials in terms of strength, flame retardancy, antistatic performance, cost, and production efficiency. It is urgent to develop a new type of idler material and preparation method to meet the needs of the coal mine industry for high-performance idlers. Summary of the Invention

[0007] In view of this, the present invention provides a bio-based phosphorus-containing inherently flame-retardant polyurethane winding tube body for coal mines, aiming to solve the problems of insufficient strength of traditional idler materials, poor flame retardant and antistatic performance, low preparation process efficiency, and unstable quality. The present invention prepares a high-strength, wear-resistant, flame-retardant, and antistatic idler tube body by introducing bio-based phosphorus-containing polyols and continuous fiber reinforcement technology and combining with an optimized winding process.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A bio-based phosphorus-containing inherently flame-retardant polyurethane winding tube body for coal mines. The tube body material is a continuous fiber-reinforced flame-retardant and antistatic polyurethane composite material, and the flame-retardant and antistatic polyurethane composite material is composed of polyurethane resin and glass fiber; the polyurethane resin includes components A and B. Among them, component A is diphenylmethane diisocyanate, and component B is a polyol mixture obtained by mixing polyester polyol, bio-based phosphorus-containing polyol, flame retardant, and antistatic agent in a set ratio.

[0010] Among them, component A is diphenylmethane diisocyanate (MDI), and component B is polyester polyol; the bio-based phosphorus-containing polyol has the structural formula I: Among R1 to R11, there are 2 to 4 compounds with the structural formula II, and the rest are The structural formula II is

[0011]

[0012] Further, the preparation method of the tube body includes the following steps:

[0013] Step 1: The traction fibers respectively pass through a tensioner and enter an impregnating bath; then they are traction-wound onto a mandrel.

[0014] Step 2: Prepare a bio-based phosphorus-containing polyol, and mix it with a polyester polyol, a flame retardant, and an antistatic agent in proportion to obtain Component B. Then add Components A and B to a two-component resin mixer.

[0015] Step 3: Start the two-component resin mixer and inject the mixed resin into the impregnating bath.

[0016] Step 4: Start the winding machine and move the impregnating bath along the track, and adjust the fiber winding angle by adjusting the speeds of the two.

[0017] Step 5: After winding is completed, put the mandrel and the winding layer into an oven.

[0018] Step 6: After the winding layer is cured, demold it with a demolding machine to obtain a wound tube.

[0019] Step 7: Perform surface treatment on the wound tube.

[0020] Step 8: Composite a wear-resistant layer on the surface of the wound tube to obtain a high-strength and wear-resistant polyurethane composite roller tube body for coal mines.

[0021] Further, in Step 2, the method for preparing the bio-based phosphorus-containing polyol includes the following steps:

[0022] (1) Add phytic acid and ammonia water to a reaction kettle in sequence, dissolve them with water, heat to 30 - 80 °C, carry out a condensation reflux reaction for 20 - 200 min, and obtain an intermediate of Structural Formula III after purification and drying.

[0023] (2) Add the compound of Structural Formula II to a flask equipped with a condensation device, add an organic solvent and heat to 30 °C - 100 °C to dissolve. At 25 °C - 150 °C, add the intermediate of Structural Formula III obtained in step (1) and react for 1 h - 10 h, then remove the solvent. After drying, the bio-based phosphorus-containing polyol can be obtained.

[0024] The Structural Formula III is wherein R13 - R24 contain 2 - 4 H⁺, and the rest are

[0025] The Structural Formula II is

[0026] Preferably, in step (1), the molar ratio of phytic acid to ammonia water is 1:8 - 10.

[0027] Preferably, in step (2), the organic solvent is any one or more of acetone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, chlorobenzene, dichlorobenzene, trichlorobenzene, ethylene glycol methyl ether, ethylene glycol ethyl ether, or 1,4-dioxane.

[0028] Preferably, in step (2), the molar ratio of the compound of formula II to the intermediate of formula III is 2-4:1.

[0029] Preferably, in step 5, the oven temperature is 60°C - 150°C, and the winding tube heating and curing parameters are: 150°C, 2 h.

[0030] Furthermore, the formula for calculating the fiber winding angle is:

[0031]

[0032] Where:

[0033] v: the moving speed of the dipping tank, m / min;

[0034] N: the rotational speed of the mold mandrel, rpm;

[0035] r: the radius of the pipe body, m.

[0036] Preferably, in step 7, the method for surface treatment of the winding tube is any one or more of sanding, laser treatment, plasma treatment, ablation.

[0037] Preferably, the material of the wear-resistant layer is any one or more of polyurethane, nylon, polytetrafluoroethylene, ultra-high molecular weight polyethylene, and the composite process adopts any one of injection molding, gluing, casting, molding, mechanical connection.

[0038] The beneficial effects of the present invention are as follows:

[0039] 1. High-efficiency intrinsic flame retardancy: The present invention uses bio-based phosphorus-containing polyols to directly incorporate bio-based DOPO derivatives into the polyurethane molecular chain to form an intrinsically flame-retardant and antistatic polyurethane composite material. When this material burns, it can self-crosslink and expand to form a dense carbon layer, and crosslink with polymer pyrolysis small molecules to generate a carbon layer with high thermal stability, effectively isolating oxygen and heat. The flame retardancy reaches UL94 V-0 level, the oxygen index meets the requirements of GB / T 2406, and meets the MT113 standard. Compared with traditional externally added flame retardants, the intrinsic flame retardant design eliminates the problem of flame retardant precipitation, significantly improves the flame retardancy efficiency, reduces the amount of flame retardant used, and lowers the material cost and environmental pollution risk.

[0040] 2. Excellent mechanical properties: Through continuous glass fiber reinforcement technology and chemical bonding between bio-based phosphorus-containing polyols and polyurethane resins, the roller tube body of the present invention has excellent mechanical properties. Tests show that the tensile strength is ≥800 MPa, about 6 times higher than that of traditional plastic rollers, and it has a relatively high ring stiffness. The introduction of DOPO derivatives not only enhances the rigidity of the molecular chain but also improves the overall strength of the composite material, enabling the roller to withstand high loads and impacts in underground coal mines and extending the service life by about 1.5 times.

[0041] 3. Excellent antistatic performance: The synergistic effect of bio-based phosphorus-containing polyols and antistatic agents can make the surface resistivity of the roller tube body ≤3×10 8 Ω, meeting the MT113 standard, which can effectively prevent the accumulation of static electricity and reduce the fire risk caused by static sparks. This characteristic significantly improves the safety of the roller in the complex environment of underground coal mines.

[0042] 4. Halogen-free environmental protection and sustainability: The bio-based binary terminal hydroxyl DOPO derivative flame retardant of the present invention adopts a halogen-free environmental protection design. The synthesis monomers (such as phytic acid) are widely sourced and renewable, reducing the carbon footprint in the production process and dependence on non-renewable resources. Compared with traditional halogen-containing flame retardants, the present invention avoids the generation of toxic gases during combustion, meets the requirements of green manufacturing and sustainable development, and has significant environmental friendliness.

[0043] 5. Excellent wear resistance and corrosion resistance: By surface-composite wear-resistant layers (such as polyurethane, ultra-high molecular weight polyethylene, etc.), the wear resistance of the roller tube body is increased by 15% - 25%, effectively resisting the wear of materials and the environment and reducing the damage to the conveyor belt. The corrosion resistance of the polyurethane composite material is better than that of metal rollers, and it can operate stably for a long time in humid and corrosive environments, especially suitable for the complex and harsh environment of underground coal mines, reducing the maintenance cost.

[0044] 6. Lightweight design: The density of the polyurethane composite material is only about one-fourth of that of the steel tube body, realizing the lightweight design of the roller. This not only reduces the overall weight of the roller, lowers the transportation and installation costs, but also reduces the inertial force during the operation of the roller, thereby reducing the friction between the roller and the conveyor belt and improving the operating efficiency of the conveyor.

[0045] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] To make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, where:

[0047] Figure 1 It is a schematic diagram of the preparation process of the bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding tube body for coal mines in the present invention.

[0048] Figure 2 It is a schematic diagram of the arrangement of different angles of fiber winding in the present invention.

[0049] Figure 3 It is the composite structure of the winding tube and the composite wear-resistant layer in the present invention. Specific Embodiments

[0050] The following uses specific specific examples to illustrate the embodiments of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0051] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and cannot be understood as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0052] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be understood as a limitation to the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0053] Please refer to Figures 1 to 3, a bio-based phosphorus-containing intrinsically flame-retardant polyurethane roller winding tube body for coal mines. The tube body material is a continuous fiber-reinforced flame-retardant and antistatic polyurethane composite material, and the flame-retardant and antistatic polyurethane composite material is composed of polyurethane resin and glass fiber; the polyurethane resin includes components A and B. Among them, component A is diphenylmethane diisocyanate, and component B is a polyol mixture obtained by mixing polyester polyol, bio-based phosphorus-containing polyol, flame retardant, and antistatic agent in a set ratio;

[0054] Among them, component A can be selected from 4,4'-MDI, modified MDI, polymeric MDI (PMDI), etc. MDI for pultrusion; the polyester polyol in component B can be selected from adipic acid-based polyester polyols, phthalic anhydride (PA)-based polyester polyols, hydrolysis-resistant polyester polyols, etc., polyols for pultrusion;

[0055] The mixing ratio of the flame retardant and the bio-based phosphorus-containing polyol is determined according to the flame retardant grade requirements. For example, to achieve V0-level flame retardancy, the mass ratio of polyester polyol to bio-based phosphorus-containing polyol is 72:28; to meet the MT113 flame retardant requirements, the mass ratio of polyester polyol to bio-based phosphorus-containing polyol is: 63:37.

[0056] The antistatic agent can be selected from one or a mixture of 1,3-dimethylimidazolium tetrafluoroborate, N-octylpyridinium bromide, N-butyl-N-methylpiperidinium bromide, N-butyl-N-methylpyrrolidinium bromide, tributylmethylammonium chloride, N-ethyl,methylmorpholinium bromide, and tributylethylphosphonium bromide ionic liquids, as well as carbon fiber, etc. According to the different surface resistances achieved, the dosage of the antistatic agent is different. For example, when the surface resistance reaches 10 9 Ω, the polyol mixture: antistatic agent is 72:28; when the surface resistance reaches 10 8 Ω, the polyol mixture: antistatic agent is 65:35; when the surface resistance < 10 8 Ω, carbon fiber is used on the surface.

[0057] The bio-based phosphorus-containing polyol is of structural formula Ⅰ: Among them, R1 to R11 contain 2 to 4 compounds of structural formula Ⅱ, and the rest are Structural formula Ⅱ is

[0058]

[0059] The preparation method of the tube body includes the following steps:

[0060] Step 1: The traction fibers respectively pass through a tensioner and enter an impregnating tank; then they are traction-wound onto a die mandrel;

[0061] Step 2: Prepare bio-based phosphorus-containing polyol, and mix it with polyester polyol, flame retardant, antistatic agent, etc. in proportion to obtain Component B. Then add Components A and B into a two-component resin mixer;

[0062] Step 3: Turn on the two-component resin mixer, and inject the mixed resin into the dipping tank;

[0063] Step 4: Turn on the winding machine and make the dipping tank move along the track, and adjust the fiber winding angle by adjusting the speeds of the two;

[0064] Step 5: After winding is completed, put the mandrel and the winding layer into the oven;

[0065] Step 6: After the winding layer is cured, use a demolding machine for demolding to obtain a wound pipe;

[0066] Step 7: Perform surface treatment on the wound pipe;

[0067] Step 8: Compound a wear-resistant layer on the surface of the wound pipe to obtain a high-strength and wear-resistant polyurethane composite roller pipe body for coal mines.

[0068] Among them, in Step 2, the method for preparing bio-based phosphorus-containing polyol includes the following steps:

[0069] (1) Add phytic acid and ammonia water into the reaction kettle in sequence, and the molar ratio of phytic acid to ammonia water is 1:8 - 10; after adding water to dissolve, heat to 30 - 80 °C, and carry out condensation reflux reaction for 20 - 200 min. After purification and drying, obtain the intermediate of Structural Formula III;

[0070] (2) Add the compound of Structural Formula II (DOPO-OH) into the flask equipped with a condensation device, add an organic solvent, and heat up to 30 °C - 100 °C for dissolution. The organic solvent is any one or several of acetone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, chlorobenzene, dichlorobenzene, trichlorobenzene, ethylene glycol methyl ether, ethylene glycol ethyl ether or 1,4-dioxane. At 25 °C - 150 °C, add the intermediate of Structural Formula III obtained in step (1) and react for 1 h - 10 h, then remove the solvent. After drying, bio-based phosphorus-containing polyol can be obtained;

[0071] Among them, Structural Formula III is Among R13 - R24, there are 2 - 4 H+, and the rest are

[0072] Structural Formula II is The molar ratio of the compound of Structural Formula II to the intermediate of Structural Formula III is 2 - 4:1.

[0073] Among them, in Step 4, the calculation formula for the fiber winding angle is:

[0074]

[0075] Wherein:

[0076] v: The moving speed of the dipping tank, m / min;

[0077] N: The rotational speed of the mold mandrel, rpm;

[0078] r: The radius of the pipe body, m.

[0079] In Step 5, the oven temperature: The oven temperature is 60°C - 150°C, 100°C in summer, and 60°C in winter. The heating and curing parameters of the winding pipe are: 150°C, 2h.

[0080] In Step 7, the method for surface treatment of the winding pipe is any one or several of roughening, laser, plasma, ablation.

[0081] In Step 8, the material of the wear-resistant layer is any one or several of polyurethane, nylon, polytetrafluoroethylene, ultra-high molecular weight polyethylene, and the composite process adopts any one of injection molding, gluing, casting, molding, mechanical connection.

[0082] In the following examples, Component A used is 4,4'-MDI, the polyester polyol in Component B is adipic acid-based polyester polyol, the flame retardant is aluminum hydroxide, and the antistatic agent is 1,3-dimethylimidazolium tetrafluoroborate.

[0083] Example 1

[0084] Formulation: Polyester polyol 24.2 phr, bio-based phosphorus-containing polyol 15.4 phr, antistatic agent 15.4 phr; MDI: 45 phr; Glass fiber: 80 wt%; Glass fiber winding angle: ±55°.

[0085] Process: The moving speed of the dipping tank is 0.5 m / min, and the heating and curing parameters of the pipe body are: 150°C, 2h.

[0086] Example 2

[0087] Formulation: Polyester polyol: 14.6 phr, bio-based phosphorus-containing polyol: 20.4 phr, antistatic agent: 20 phr; MDI: 45 phr; Glass fiber: 80 wt%; Glass fiber winding angle: ±30°.

[0088] Process: The moving speed of the dipping tank is 0.5 m / min, and the heating and curing parameters of the pipe body are: 150°C, 2h.

[0089] Example 3

[0090] Formulation: 16.6 phr of polyester polyol, 13 phr of bio-based phosphorus-containing polyol, 10 phr of liquid flame retardant, 15.4 phr of antistatic agent; MDI: 45 phr; glass fiber: 80 wt%; glass fiber winding angle: ±80°.

[0091] Process: The moving speed of the dipping tank is 0.5 m / min, and the tube body heating and curing parameters are: 150 °C, 2 h.

[0092] Example 4

[0093] Formulation: 34.6 phr of polyester polyol, 20.4 phr of bio-based phosphorus-containing polyol, surface carbon fiber of antistatic agent; MDI: 45 phr; glass fiber: 80 wt%; glass fiber winding angle: ±55°:±30° = 1:1.

[0094] Process: The moving speed of the dipping tank is 0.5 m / min, and the tube body heating and curing parameters are: 150 °C, 2 h.

[0095] Comparative Example 1

[0096] Formulation: 55 phr of polyester polyol, MDI: 45 phr; glass fiber: 80 wt%; glass fiber winding angle: ±55°:±80° = 1:1.

[0097] Process: The moving speed of the dipping tank is 0.5 m / min, and the tube body heating and curing parameters are: 150 °C, 2 h.

[0098] Comparative Example 2

[0099] Formulation: 14.6 phr of polyester polyol, 25 phr of liquid flame retardant, 15.4 phr of antistatic agent; MDI: 45 phr; glass fiber: 80 wt%; glass fiber winding angle: ±55°:±10° = 1:1.

[0100] Process: The moving speed of the dipping tank is 0.5 m / min, and the tube body heating and curing parameters are: 150 °C, 2 h.

[0101] The products prepared in the above examples were tested, and the test results are shown in the following table:

[0102]

[0103] From the comparison results, it can be seen that due to the participation of the bio-based phosphorus-containing polyol in the reaction, this characteristic can not only ensure that the composite material prepared without adding a flame retardant (additive type) can achieve the flame retardant effect (the flame retardancy can reach MT113), but also maintain the mechanical properties of the composite material. At the same time, a large amount of other additives (such as antistatic agent, making the surface resistance ≤ 3×10 8The mechanical properties of the composite material are only slightly reduced, as shown in Example 2; by reducing the amounts of bio-based phosphorus-containing polyol and antistatic agent, composite materials with different flame retardant and antistatic specifications can be prepared. For example, the flame retardant performance of the composite material in Example 1 reaches V0, and the surface resistance reaches 3.8×10 9 Ω, and the mechanical properties are excellent; due to the high price of bio-based phosphorus-containing polyol, using a method of mixing bio-based phosphorus-containing polyol with additive flame retardant or completely using additive flame retardant to prepare the composite material to reduce the cost will reduce the mechanical properties of the composite material, such as in Example 3 and Comparative Example 2; to further reduce the surface resistance of the composite material profile, using carbon fiber on the surface of the composite material can make the surface resistance ≤10 3 Ω, and the mechanical properties are almost the same as those of the non-flame retardant and antistatic composite material, as shown in Example 4.

[0104] The winding angle (the angle with the axis) of the fiber will affect the tensile strength and ring stiffness of the pipe body. The influencing method is that the angle is directly proportional to the ring stiffness and inversely proportional to the tensile strength. To balance the tensile strength and ring stiffness, multi-angle hybrid winding can be used.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding tube body for coal mines, characterized in that: The tube body material is a continuous fiber-reinforced flame-retardant and antistatic polyurethane composite material, and the flame-retardant and antistatic polyurethane composite material is composed of polyurethane resin and glass fiber; the polyurethane resin includes components A and B. Among them, component A is diphenylmethane diisocyanate, and component B is a polyol mixture obtained by mixing polyester polyol, bio-based phosphorus-containing polyol, flame retardant, and antistatic agent in a set ratio; The bio-based phosphorus-containing polyol is of structural formula I: Among R1 to R11, there are 2 to 4 compounds of structural formula II, and the rest are The structural formula II is 2. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding tube body for coal mines according to claim 1, wherein The preparation method of the tube body includes the following steps: Step 1: The traction fiber passes through the tensioner and enters the dipping tank respectively; then it is traction-wound onto the die mandrel; Step 2: Prepare the bio-based phosphorus-containing polyol, and mix it with polyester polyol, flame retardant, and antistatic agent in proportion to obtain component B, and add components A and B to the two-component resin mixer; Step 3: Turn on the two-component resin mixer and inject the mixed resin into the dipping tank; Step 4: Turn on the winding machine and make the dipping tank move along the track, and adjust the fiber winding angle by adjusting the speeds of the two; Step 5: After winding is completed, put the mandrel and the winding layer into the oven; Step 6: After the winding layer is cured, use a demolding machine for demolding to obtain a wound tube; Step 7: Perform surface treatment on the wound tube; Step 8: Compound a wear-resistant layer on the surface of the wound tube to obtain a high-strength and wear-resistant polyurethane composite material idler tube body for coal mines.

3. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding tube body for coal mines according to claim 2, characterized in that, In step 2, the method for preparing the bio-based phosphorus-containing polyol includes the following steps: (1) Add phytic acid and ammonia water to the reaction kettle in sequence, dissolve with water and heat to 30-80 °C, carry out condensation reflux reaction for 20-200 min, and obtain the intermediate of structural formula III after purification and drying; (2) Add the compound of structural formula II to the flask equipped with a condensation device, add an organic solvent and heat up to 30 °C - 100 °C to dissolve, and react with the intermediate of structural formula III obtained in step (1) at 25 °C - 150 °C for 1 h - 10 h, then remove the solvent, and obtain the bio-based phosphorus-containing polyol after drying; The structural formula Ⅲ is Among R13 to R24, there are 2 to 4 H+, and the rest are The structural formula II is 4. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding pipe body for coal mines according to claim 3, wherein: In step (1), the molar ratio of phytic acid to ammonia water is 1:8 - 10.

5. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding tube body for coal mines according to claim 3, characterized in that In step (2), the organic solvent is any one or several of acetone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, chlorobenzene, dichlorobenzene, trichlorobenzene, ethylene glycol methyl ether, ethylene glycol ethyl ether, or 1,4-dioxane.

6. The bio-based phosphorus-containing intrinsically flame-retardant polyurethane idler winding tube body for coal mines according to claim 3, wherein: In step (2), the molar ratio of the compound of structural formula II to the intermediate of structural formula III is 2 - 4:

1.

7. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding pipe body for coal mines according to claim 2, wherein: In step 5, the oven temperature: the oven temperature is 60 °C - 150 °C, and the heating and curing parameters of the wound tube are: 150 °C, 2 h.

8. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding tube body for coal mines according to claim 2, wherein, The calculation formula for the fiber winding angle is: Where: v: the moving speed of the dipping tank, m / min; N: the rotation speed of the die mandrel, rpm; r: the radius of the tube body, m.

9. The bio-based phosphorus-containing intrinsically flame-retardant polyurethane idler winding pipe body for coal mines according to claim 2, characterized in that: In step 7, the method for surface treatment of the wound tube is any one or several of sandblasting, laser, plasma, ablation.

10. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding pipe body for coal mines according to claim 2, wherein: The material of the wear-resistant layer is any one or several of polyurethane, nylon, polytetrafluoroethylene, ultra-high molecular weight polyethylene, and the composite process adopts any one of injection molding, adhesive bonding, casting, molding, and mechanical connection.

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