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

Abstract

The invention discloses a bio-based phosphorus-containing intrinsic flame-retardant polyurethane carrier roller winding pultrusion 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 pultrusion process, the carrier roller pipe body with high strength, wear resistance, flame retardance and static electricity resistance is prepared.

Description

Technical Field

[0001] The present 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 intrinsically flame-retardant polyurethane idler winding and pultrusion 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 approximately 35% of the total cost of belt conveyors. Their performance directly affects the operating 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 likely to adhere 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 surfaces may cause tearing damage to the conveyor belt. Their anti-corrosion and sealing performances are also relatively poor, increasing the maintenance cost. Ceramic idlers have excellent insulation, wear resistance, and corrosion resistance, and are not prone to material adhesion, 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 situations. 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 little wear on the conveyor belt, and have a relatively long service life. However, plastic idlers have poor rigidity, are difficult to withstand high-intensity loads, and have high production costs and expensive prices, which limit 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 underground environment of coal mines 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 welds, resulting in quality problems of idlers during use, affecting the overall performance and service life.

[0005] In recent years, the application of composite materials in idler manufacturing has gradually increased. For example, fiber-reinforced composite materials have attracted attention due to their high strength and wear resistance, but 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, but 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 nature, 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, but their combination in bio-based materials and their application in the winding and pultrusion tube bodies of idlers still face technical challenges. In addition, the existing winding and pultrusion processes have deficiencies in aspects such as fiber angle control, resin infiltration uniformity, and curing process optimization, resulting in unstable performance of the prepared idler tube bodies and difficulty in meeting the requirements of high strength and high durability in coal mines.

[0006] In summary, the existing idler materials have many deficiencies in terms of strength, flame retardancy, antistatic performance, cost, and production efficiency. There is an urgent need to develop a new type of idler material and preparation method to meet the needs of the coal mining 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 and pultrusion tube body for coal mines, aiming to solve the problems of insufficient strength, poor flame retardant and antistatic performance of traditional idler materials, as well as 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, combined with an optimized winding and pultrusion 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 and pultrusion 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, wherein 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 has the structural formula Ⅰ:

[0010] Among them, R1 to R11 contain 2 to 4 compounds with the structural formula Ⅱ, and the rest are The structural formula Ⅱ is

[0011]

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

[0013] Step 1: The traction fibers pass through the oven and are traction-fed into the mold; the traction felt / cloth enters the mold, and the fibers in the yarn bobbin are wound onto the mold mandrel.

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

[0015] Step 3: Turn on the mold heating device for 1.5 h to fully heat the mold.

[0016] Step 4: Turn on the oven, start the traction device, and start the forward / backward winding device.

[0017] Step 5: Turn on the injection machine and the cutting machine.

[0018] Step 6: The resin and glass fiber are cured in the mold to obtain a flame-retardant and antistatic bio-based phosphorus-containing intumescent flame-retardant polyurethane pipe, which is cut to a fixed length by the cutting machine to obtain a polyurethane composite winding pultrusion pipe.

[0019] Step 7: Perform surface treatment on the winding pultrusion pipe.

[0020] Step 8: Composite a wear-resistant layer on the surface of the winding pipe to obtain a high-strength and wear-resistant polyurethane composite idler pipe 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 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.

[0023] (2) Add the compound of Structural Formula II to the flask equipped with a condensation device, add an organic solvent and heat to 30 °C - 100 °C to dissolve, and 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, and obtain the bio-based phosphorus-containing polyol after drying.

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

[0025] The Structural Formula II is

[0026] Further, 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] Furthermore, in step (2), the molar ratio of the compound of structural formula II to the intermediate of structural formula III is 2 - 4:1.

[0029] Furthermore, in step 3, the heating temperature of the mold: 150°C - 210°C, divided into three zones. The mold temperature at the front end of the mold near the yarn inlet is 150°C - 170°C, the middle section is 170°C - 190°C, and the rear section near the outlet of the tubular profile is 190°C - 210°C.

[0030] In step 4, the oven temperature: the oven temperature is 60°C - 150°C, and the fiber drawing speed: 0.2 - 2 m / min; in step 5, the injection pressure: 0.5 - 1 MPa.

[0031] Furthermore, the calculation formula for the fiber winding angle is:

[0032]

[0033] Where:

[0034] v: the pultrusion drawing speed of the tube body, m / min;

[0035] N: the rotational speed of the positive / negative winding device, RPM;

[0036] r: the radius of the tube body, m.

[0037] Preferably, in step 7, the method for surface treatment of the wound tube is any one or more of roughening, laser treatment, plasma treatment, ablation.

[0038] 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.

[0039] The beneficial effects of the present invention are as follows:

[0040] 1. High-efficiency inherent flame retardancy: The present invention uses bio-based phosphorus-containing polyols to directly incorporate bio-based DOPO derivatives into the polyurethane molecular chain, forming an inherently 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 the pyrolysis small molecules of the polymer to generate a carbon layer with high thermal stability, effectively isolating oxygen and heat. The flame retardancy can reach UL94 V-0 level and meet the MT113 standard. Compared with traditional additive flame retardants, the inherent flame retardancy design eliminates the problem of flame retardant precipitation, significantly improves the flame retardancy efficiency, reduces the dosage of additive flame retardants, and improves the mechanical properties of the flame-retardant polyurethane composite material.

[0041] 2. Excellent mechanical properties: Through continuous glass fiber reinforcement technology and chemical bonding between bio-based phosphorus-containing polyols and polyurethane resin, reducing the dosage of additive flame retardants, the roller tube body of the present invention has excellent mechanical properties. Tests show that the tensile strength of the composite material prepared by the pultrusion process is ≥600 MPa, about 6 times higher than that of traditional plastic rollers, and has a high ring stiffness. The introduction of DOPO derivatives reduces or eliminates the use of additive flame retardants, not only enhancing the rigidity of the molecular chain but also improving the overall strength of the composite material, enabling the roller to withstand high loads and impacts in coal mines and extending its service life by about 1.5 times.

[0042] 3. Outstanding 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, effectively preventing static electricity accumulation and reducing the fire risk caused by static sparks. This characteristic significantly improves the safety of the roller in the complex environment of coal mines.

[0043] 4. Halogen-free environmental protection and sustainability: The bio-based binary hydroxyl-terminated 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.

[0044] 5. Excellent wear resistance and corrosion resistance: By surface compounding a wear-resistant layer (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 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 coal mines, reducing the maintenance cost.

[0045] 6. Lightweight design: The density of the polyurethane composite material is only about one-fourth of that of the steel pipe body, achieving the lightweight design of the idler. This not only reduces the overall weight of the idler, lowers the transportation and installation costs, but also decreases the inertial force during the operation of the idler, thereby reducing the friction between the idler and the conveyor belt and improving the operation efficiency of the conveyor.

[0046] 7. High production efficiency: Using a large amount of additive flame retardants to achieve a good flame retardant effect will affect the curing time and quality of the polyurethane, resulting in a slow pultrusion speed (below 0.25 m / min). Since the bio-based phosphorus-containing polyol used in the present invention participates in the reaction of the polyurethane and belongs to inherent flame retardancy, it has no impact on the reaction of the polyurethane, with a fast pultrusion speed and high production efficiency.

[0047] 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 taught 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

[0048] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in preferred detail below in conjunction with the drawings, where:

[0049] Figure 1 It is a schematic diagram of the preparation process of the bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding and pultrusion pipe body in the present invention.

[0050] Figure 2 is Figure 1 A schematic diagram of the structure of the forward / backward winding device used in the preparation process.

[0051] Figure 3 It is a schematic diagram of the arrangement of different angles of fiber winding in the present invention.

[0052] Figure 4 It is the composite structure of the winding pipe and the composite wear-resistant layer in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0053] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand 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 implementation manners, and 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 diagrams provided in the following examples only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following examples and the features in the examples can be combined with each other.

[0054] Among them, the accompanying drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; in order to better illustrate the embodiments of the present invention, some components in the accompanying drawings will be omitted, enlarged or reduced, which does not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted.

[0055] In the accompanying 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 accompanying drawings, and are 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 accompanying drawings are only for illustrative purposes and should not be construed 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.

[0056] Please refer to Figures 1 to 4 , a bio-based phosphorus-containing intrinsically flame-retardant polyurethane roller winding and pultrusion tube for coal mines. The tube 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.

[0057] Among them, the bio-based phosphorus-containing polyol has the structural formula I:

[0058] Among them, R1 to R11 contain 2 to 4 compounds with the structural formula II, and the rest are The structural formula II is

[0059]

[0060] Among them, component A can select MDI for pultrusion such as 4,4'-MDI, modified MDI, and polymeric MDI (PMDI), and the polyester polyol in component B can select polyester polyols for pultrusion such as adipic acid-based polyester polyols, phthalic anhydride (PA)-based polyester polyols, and hydrolysis-resistant polyester polyols.

[0061] 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 the polyester polyol to the bio-based phosphorus-containing polyol is 72:28; to meet the MT113 flame retardant requirement, the mass ratio of the polyester polyol to the bio-based phosphorus-containing polyol is 63:37.

[0062] The antistatic agent can be selected from one or a mixture of more than one 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 mass ratio of the polyol mixture to the antistatic agent is 72:28; when the surface resistance reaches 10 8 Ω, the mass ratio of the polyol mixture to the antistatic agent is 65:35; when the surface resistance < 10 8 Ω, carbon fiber is used on the surface.

[0063] The bio-based phosphorus-containing polyol has the structural formula Ⅰ: Among them, R1 to R11 contain 2 to 4 compounds with the structural formula Ⅱ, and the rest are The structural formula Ⅱ is

[0064]

[0065] The preparation method of the pipe body includes the following steps:

[0066] Step 1: The traction fiber passes through the oven and is drawn into the mold; the traction felt / cloth enters the mold, and the fiber in the yarn bobbin is wound around the mold mandrel;

[0067] Step 2: Prepare the bio-based phosphorus-containing polyol, and mix it with the polyester polyol, flame retardant, antistatic agent, etc. in proportion to obtain component B, and add components A and B to the two-component resin mixer;

[0068] Step 3: Turn on the mold heating device for 1.5 h to fully heat the mold; in Step 3, the mold heating temperature is 150°C - 210°C, divided into three zones. The mold temperature at the front end near the yarn inlet is 150°C - 170°C, the middle section is 170°C - 190°C, and the rear section near the pipe profile outlet is 190°C - 210°C;

[0069] Step 4: Turn on the oven, and the oven temperature is 60°C - 150°C; start the traction device, and the fiber traction speed is 0.2 - 2 m / min; start the positive / negative winding device;

[0070] Step 5: Turn on the injection molding machine and the cutting machine, and the injection pressure is 0.5 - 1 MPa;

[0071] Step 6: The resin and glass fiber are cured in a mold to obtain a flame-retardant and antistatic bio-based phosphorus-containing intumescent polyurethane tube, which is cut to a fixed length by a cutting machine to obtain a polyurethane composite winding and pultrusion tube;

[0072] Step 7: Surface treatment is carried out on the winding and pultrusion tube; the method for surface treatment of the winding tube is any one or several of roughening, laser, plasma, and ablation.

[0073] Step 8: A wear-resistant layer is compounded on the surface of the winding tube to obtain a high-strength and wear-resistant polyurethane composite idler tube body for coal mines. Among them, the material of the wear-resistant layer is any one or several of polyurethane, nylon, polytetrafluoroethylene, and ultra-high molecular weight polyethylene, and the composite process adopts any one of injection molding, gluing, casting, molding, and mechanical connection.

[0074] Among them, in Step 2, the method for preparing the bio-based phosphorus-containing polyol includes the following steps:

[0075] (1) Phytic acid and ammonia water are sequentially added to a reaction kettle, the molar ratio of phytic acid to ammonia water is 1:8 - 10, after adding water to dissolve, it is heated to 30 - 80 °C, and the condensation reflux reaction is carried out for 20 - 200 min. After purification and drying, an intermediate of Structural Formula III is obtained;

[0076] (2) The compound of Structural Formula II is added to a flask equipped with a condensation device, after adding an organic solvent, it is heated to 30 °C - 100 °C to dissolve, and at 25 °C - 150 °C, the intermediate of Structural Formula III obtained in step (1) is added and reacted for 1 h - 10 h, then the solvent is removed, and after drying, the bio-based phosphorus-containing polyol can be obtained;

[0077] Structural Formula III is Among them, R13 - R24 contains 2 - 4 H+, and the rest are

[0078] Structural Formula II is

[0079] 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. The molar ratio of the compound of Structural Formula II (DOPO-OH) to the intermediate of Structural Formula III is 2 - 4:1.

[0080] The calculation formula for the fiber winding angle is:

[0081]

[0082] Among them:

[0083] v: Pultrusion traction speed of the pipe body, m / min;

[0084] N: Rotation speed of the positive / negative winding device, RPM;

[0085] r: Radius of the pipe body, m.

[0086] 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.

[0087] Example 1 (basic formulation)

[0088] 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: ±60°.

[0089] Process parameters: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0090] Example 2 (high flame retardant formulation)

[0091] 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: ±70°.

[0092] Process parameters: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0093] 3. Example 3

[0094] Formulation: Polyester polyol 16.6 phr, bio-based phosphorus-containing polyol 13 phr, liquid flame retardant 10 phr, antistatic agent 15.4 phr; MDI: 45 phr; Glass fiber: 80 wt%; Glass fiber winding angle: ±80°.

[0095] Process parameters: Pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0096] 4. Example 4

[0097] Formulation: Polyester polyol 34.6 phr, bio-based phosphorus-containing polyol 20.4 phr, antistatic agent surface carbon fiber; MDI: 45 phr; Glass fiber: 80 wt%; Glass fiber winding angle: ±50°.

[0098] Process parameters: pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0099] 5. Comparative Example 1

[0100] Formulation: polyester polyol 55 phr, MDI: 45 phr; glass fiber: 80 wt%; glass fiber winding angle: ±40°.

[0101] Process parameters: pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0102] 6. Comparative Example 2

[0103] Formulation: polyester polyol 14.6 phr, liquid flame retardant 25 phr, antistatic agent 15.4 phr; MDI: 45 phr; glass fiber: 80 wt%; glass fiber winding angle: ±30°.

[0104] Process parameters: pultrusion speed 0.5 m / min, die temperature at the front section 160 °C, middle section 180 °C, rear section 190 °C, injection pressure 0.8 MPa.

[0105] The products prepared from the above examples were tested, and the test results are shown in the following table:

[0106]

[0107] From the comparison results, it can be seen that due to the participation of 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 (flame retardant up to MT113), but also maintain the mechanical properties of the composite material. At the same time, when adding a large amount of other additives (such as antistatic agent, making the surface resistance ≤ 3×10 8 Ω), the mechanical properties of the composite material only decrease slightly, as shown in Example 2; reducing the dosage of bio-based phosphorus-containing polyol and antistatic agent can prepare composite materials with different flame retardant and antistatic specifications. For example, in Example 1, the flame retardant performance of the composite material reaches V0, 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 an additive type flame retardant or completely using an additive type flame retardant to prepare the composite material to reduce the cost will reduce the mechanical properties of the composite material, such as 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.

[0108] The winding angle of the fiber (the angle with the axis) 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.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. 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 spirit and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A bio-based phosphorus-containing intrinsically flame-retardant polyurethane idler winding and pultrusion 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 has the structural formula I: Among them, among R1 to R11, there are 2 to 4 compounds with the structural formula II, and the rest are The structural formula II is 2. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding and pultrusion tube body for coal mines according to claim 1, characterized in that, The preparation method of the tube body includes the following steps: Step 1: The traction fibers pass through the oven and are drawn into the mold; the traction felt / cloth enters the mold, and the fibers in the yarn bobbin are wound around the mold mandrel; Step 2: Prepare the bio-based phosphorus-containing polyol, and mix it with the polyester polyol, flame retardant, and antistatic agent in proportion to obtain the B component, and add the A and B components to the two-component resin mixer; Step 3: Turn on the mold heating device for 1.5 h to fully heat the mold; Step 4: Turn on the oven, start the traction device, and start the positive / negative winding device; Step 5: Turn on the glue injection machine and the cutting machine; Step 6: The resin and glass fiber are cured through the mold to obtain a flame-retardant and antistatic bio-based phosphorus-containing intumescent flame-retardant polyurethane tube, which is cut to a fixed length by the cutting machine to obtain a polyurethane composite winding and pultrusion tube; Step 7: Perform surface treatment on the winding and pultrusion tube; Step 8: Compound a wear-resistant layer on the surface of the winding tube to obtain a high-strength and wear-resistant polyurethane composite idler tube body for coal mines.

3. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding and pultrusion 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 to 30 °C - 100 °C to dissolve, and 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, and dry to obtain the bio-based phosphorus-containing polyol; 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 and pultrusion tube for coal mines according to claim 3, characterized in that: In step (1), the molar ratio of the phytic acid to the ammonia water is 1:8 - 10.

5. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding and pultrusion tube body for coal mines according to claim 3, wherein 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.

6. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding and pultrusion tube body for coal mines according to claim 3, characterized in that: 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 intrinsically flame-retardant polyurethane idler winding and pultrusion tube body for coal mines according to claim 2, wherein: In step 3, the mold heating temperature is 150 °C - 210 °C, which is divided into three zones. The mold temperature at the front end of the mold near the yarn inlet is 150 °C - 170 °C, the middle section is 170 °C - 190 °C, and the rear section near the tube profile outlet is 190 °C - 210 °C; In step 4, the oven temperature is 60 °C - 150 °C, and the fiber traction speed is 0.2 - 2 m / min; in step 5, the glue injection pressure is 0.5 - 1 MPa.

8. The bio-based phosphorus-containing inherently flame-retardant polyurethane idler winding and pultrusion pipe body for coal mines according to claim 2, characterized in that, The calculation formula for the fiber winding angle is: Where: v: The pultrusion traction speed of the tube body, m / min; N: The rotation speed of the positive / negative winding device, RPM; r: The radius of the tube body, m.

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

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

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