A TPU idler roller tube material for underground coal mines and its preparation method

Abstract

This invention relates to the field of thermoplastic new materials technology, and discloses a TPU idler roller tube material for underground coal mines and its preparation method. The TPU idler roller tube material, based on 100 parts by weight, contains: 60-80 parts by weight of thermoplastic polyurethane, 10-35 parts by weight of chlorinated polyvinyl chloride, 0.4-2 parts by weight of polyphosphonic acrylonitrile, 2-5 parts by weight of conductive carbon black, 0.1-0.6 parts by weight of graphene, 0.1-0.5 parts by weight of antioxidant, and 0.2-1 parts by weight of lubricant. This invention, by using a combination of CPVC and polyphosphonic acrylonitrile as a flame retardant and conductive carbon black and graphene as an antistatic agent, enables the obtained TPU idler roller tube material for underground coal mines to possess the necessary physical and mechanical properties of idler rollers while maintaining all the excellent elasticity, wear resistance, and antistatic properties required by TPU materials, making it widely applicable in the coal mining field.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic new materials technology, specifically to a TPU idler roller tube material for use in underground coal mines and its preparation method. Background Technology

[0002] Coal, as a vital basic energy source and industrial raw material in my country, has strongly supported the country's economic and social development. my country is the world's largest producer and consumer of coal, accounting for approximately half of global production and consumption. Coal is primarily used in industries such as power generation, metallurgy, and building materials, providing a continuous source of power for the sustained and rapid growth of China's economy.

[0003] In the mining and transportation of coal, rubber belt conveyors are widely used. Idler rollers are crucial components of belt conveyors, coming in various types and in large quantities. They bear the weight of the conveyor belt, reduce belt running resistance, and ensure that the belt's verticality does not exceed a certain limit to guarantee smooth operation. Idler rollers account for 35% of the total cost of a belt conveyor and generate over 70% of the resistance; therefore, their quality is extremely important.

[0004] Idler rollers are made of either steel or polymer materials. Currently, most idlers on the market are made of steel. However, steel is prone to corrosion in humid conditions, resulting in a short lifespan. Furthermore, steel idlers are heavy, leading to high energy consumption during transportation, high installation costs, and are time-consuming, labor-intensive, and inefficient. Additionally, the operation of idlers requires significantly more electricity.

[0005] Non-metallic polymer idler rollers made of nylon, PVC, and other materials for coal mines significantly reduce their weight and improve their operating environment to some extent. By reinforcing, toughening, and functionally modifying nylon and PVC resins, they meet the requirements for materials used in coal mine pipelines. These non-metallic idler rollers are flame-retardant, anti-static, lightweight, and easy to install and adjust; they also exhibit low energy consumption and low noise during operation. However, the poor wear resistance of these non-metallic polymer idler roller materials limits their application.

[0006] Currently, TPU materials used in underground coal mines are mainly coated onto the outside of metal pipes as idler roller bodies to improve the wear resistance of the metal pipes and increase the service life of the idler roller bodies. However, commercially available TPU materials for underground coal mines use TPU as the main body, with added halogen compounds and inorganic materials such as antimony trioxide as flame retardants, and conductive carbon black as an antistatic agent to meet the requirements for flame retardancy and antistatic properties. Because the addition of these flame retardants and antistatic agents affects the elasticity of the TPU material itself and reduces the wear resistance of both the TPU material and the idler roller body, this material has not gained widespread application in the market. Summary of the Invention

[0007] The purpose of this invention is to overcome the problem of poor wear resistance of existing TPU materials used in underground coal mines, and to provide a TPU idler roller tube material for underground coal mines and its preparation method.

[0008] To achieve the above objectives, the present invention provides a TPU idler roller tube material for use in coal mines. Based on 100 parts by weight of the total weight of the TPU idler roller tube material, the material comprises: 60-80 parts by weight of thermoplastic polyurethane, 10-35 parts by weight of chlorinated polyvinyl chloride, 0.4-2 parts by weight of polyphosphonic acrylonitrile, 2-5 parts by weight of conductive carbon black, 0.1-0.6 parts by weight of graphene, 0.1-0.5 parts by weight of antioxidant, and 0.2-1 parts by weight of lubricant.

[0009] Preferably, the TPU roller tube material contains: 65-80 parts by weight of thermoplastic polyurethane, 14-30 parts by weight of chlorinated polyvinyl chloride, 0.5-2 parts by weight of polyphosphazene, 2-5 parts by weight of conductive carbon black, 0.2-0.5 parts by weight of graphene, 0.1-0.4 parts by weight of antioxidant and 0.3-0.8 parts by weight of lubricant.

[0010] Preferably, the chlorinated polyvinyl chloride has a chlorine content of 65-70%.

[0011] Preferably, the degree of polymerization of the chlorinated polyvinyl chloride is 1000-1350.

[0012] Preferably, the polyphosphononitrile has a structure as shown in structural formula (I):

[0013]

[0014] R1 and R2 are each independently selected from alkyl groups and their derivatives, and n is ≥100.

[0015] Preferably, the antioxidant is antioxidant 1010 and / or antioxidant 168.

[0016] Preferably, the lubricant is polyethylene wax.

[0017] The present invention also proposes a method for preparing the TPU idler roller tube material for underground coal mines as described above. The method includes: mixing chlorinated polyvinyl chloride, polyphosphazene, conductive carbon black, graphene, antioxidant, lubricant and thermoplastic polyurethane, and then co-extruding and granulating the mixture.

[0018] Preferably, the process of mixing chlorinated polyvinyl chloride, polyphosphazene, conductive carbon black, graphene, antioxidant, lubricant, and thermoplastic polyurethane includes:

[0019] Polyphosphazene and chlorinated polyvinyl chloride are mixed to obtain a first mixture;

[0020] Graphene was mixed with conductive carbon black to obtain a second mixture;

[0021] Antioxidants, lubricants, and a portion of thermoplastic polyurethane are mixed to obtain a third mixture;

[0022] The first mixture, the second mixture, the third mixture, and the remaining thermoplastic polyurethane are mixed.

[0023] Preferably, the temperature of the blend extrusion granulation is 160-180℃ and the rotation speed is 10-30 r / min.

[0024] The third aspect of this invention provides a TPU idler roller tube material for use in coal mines prepared by the method described above.

[0025] In the technical solution provided by this invention, chlorinated polyvinyl chloride (CPVC) and polyphosphonic acrylonitrile are used as a flame retardant, which can fully utilize the synergistic effects of chlorine, phosphorus, and nitrogen in the material, and the composite flame retardant has little impact on the elasticity of thermoplastic polyurethane elastomer (TPU). Simultaneously, conductive carbon black and graphene are used as an antistatic agent, which greatly reduces the amount of conductive carbon black used, thereby reducing the impact of the antistatic agent on the elasticity of TPU. Therefore, through the combined action of the various raw material components, this invention enables the obtained TPU idler roller tube material for underground coal mines to possess the necessary physical and mechanical properties of idlers while maintaining all the excellent elasticity, wear resistance, and antistatic properties required by TPU materials, making it widely applicable in the coal mining field. Detailed Implementation

[0026] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0027] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] This invention provides a TPU idler roller tube material for use in coal mines. Based on 100 parts by weight of the total weight of the TPU idler roller tube material, the material contains: 60-80 parts by weight of thermoplastic polyurethane, 10-35 parts by weight of chlorinated polyvinyl chloride, 0.4-2 parts by weight of polyphosphazene, 2-5 parts by weight of conductive carbon black, 0.1-0.6 parts by weight of graphene, 0.1-0.5 parts by weight of antioxidant, and 0.2-1 parts by weight of lubricant.

[0029] In a preferred embodiment, based on 100 parts by weight of the total weight of the TPU roller tube material, the TPU roller tube material contains: 65-80 parts by weight of thermoplastic polyurethane, 14-30 parts by weight of chlorinated polyvinyl chloride, 0.5-2 parts by weight of polyphosphonic acrylonitrile, 2-5 parts by weight of conductive carbon black, 0.2-0.5 parts by weight of graphene, 0.1-0.4 parts by weight of antioxidant, and 0.3-0.8 parts by weight of lubricant.

[0030] The coal mine underground idler roller tube material provided by this invention uses TPU as a base, providing excellent elasticity and wear resistance. A "CPVC + polyphosphonic acrylonitrile" combined flame retardant provides the system with highly efficient "Cl + P + N" flame retardancy, with minimal impact on TPU elasticity. "Conductive carbon black + graphene" is used as an antistatic agent, reducing the amount of conductive carbon black and thus minimizing its impact on the system's elasticity. Therefore, the TPU idler roller tube material for coal mines provided by this invention possesses the necessary physical and mechanical properties for idlers while maintaining all the excellent elasticity, wear resistance, and antistatic properties required by TPU materials, enabling its widespread application in the coal mining industry.

[0031] The present invention does not limit the specific structure of the thermoplastic polyurethane, and it can be any conventional thermoplastic polyurethane in the art. Furthermore, the present invention does not impose any special restrictions on the source of the thermoplastic polyurethane; it can be a commercially available product or prepared by means well known to those skilled in the art. In one specific embodiment, the thermoplastic polyurethane was purchased from Yantai Wanhua, and its brand name is WHT-1565IC.

[0032] In a preferred embodiment, the chlorinated polyvinyl chloride (CPVC) has a chlorine content of 65-70%. More preferably, the degree of polymerization of the chlorinated polyvinyl chloride is 1000-1350. By using chlorinated polyvinyl chloride with the above-mentioned chlorine content and degree of polymerization, its impact on the elasticity of TPU is reduced, thereby improving the wear resistance of the resulting TPU idler roller tube material for underground coal mines.

[0033] In this invention, the polyphosphononil has the chemical formula [NPR1R2]n. In a preferred embodiment, the polyphosphononil has a structure as shown in structural formula (I):

[0034]

[0035] R1 and R2 are each independently selected from alkyl groups and their derivatives, and n is ≥100.

[0036] In specific embodiments, R1 and R2 can be the same or different. The alkyl derivative can be methoxy, ethoxy, phenoxy, p-methylphenoxy, 1-6 carbofluorooxy groups, amino groups, or aniline groups, etc. Preferably, n is an integer between 100 and 250.

[0037] The present invention does not limit the specific type of antioxidant, which can be a conventional antioxidant in the art. In a preferred embodiment, the antioxidant is antioxidant 1010 and / or antioxidant 168, more preferably a mixture of antioxidant 1010 and antioxidant 168.

[0038] In a preferred embodiment, the lubricant is polyethylene wax (PE wax), also known as polymer wax.

[0039] The present invention also proposes a method for preparing the TPU idler roller tube material for underground coal mines as described above. The method includes: mixing chlorinated polyvinyl chloride, polyphosphazene, conductive carbon black, graphene, antioxidant, lubricant and thermoplastic polyurethane, and then co-extruding and granulating the mixture.

[0040] It is understood that in the method described in this invention, during the production of TPU roller tube material, it is essential to ensure the dryness of all raw material components. Therefore, all raw materials need to be dehumidified first. In a specific embodiment, the dehumidification process includes: dehumidifying TPU and CPVC by heating with hot air at a temperature of 70-80°C for 4-5 hours; other raw materials (polyphosphazene, conductive carbon black, graphene, antioxidants, and lubricants) can be stored in a cool, ventilated, and dry place and are ready to use after opening the bag.

[0041] Because the amounts of polyphosphononitrile, graphene, composite antioxidants, and lubricants are relatively small, they are not easily dispersed uniformly. To better ensure uniform dispersion of the raw material components, in a preferred embodiment, the process of mixing chlorinated polyvinyl chloride, polyphosphononitrile, conductive carbon black, graphene, antioxidants, lubricants, and thermoplastic polyurethane includes:

[0042] Polyphosphazene and chlorinated polyvinyl chloride are mixed to obtain a first mixture;

[0043] Graphene was mixed with conductive carbon black to obtain a second mixture;

[0044] Antioxidants, lubricants, and a portion of thermoplastic polyurethane are mixed to obtain a third mixture;

[0045] The first mixture, the second mixture, the third mixture, and the remaining thermoplastic polyurethane are mixed.

[0046] By using the above mixing method, the pre-dispersed small dose of additives can be more evenly dispersed into the TPU main material, achieving the goal of uniform dispersion of each raw material component in the system.

[0047] In a preferred embodiment, the blending extrusion granulation is carried out in a twin-screw extruder.

[0048] In a preferred embodiment, the temperature of the blend extrusion granulation is 160–180°C, and the rotation speed is 10–30 r / min.

[0049] The present invention also provides a TPU idler roller tube material for use in coal mines prepared by the method described above.

[0050] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto. Unless otherwise specified, the experimental materials used in the following embodiments are all commercially available products.

[0051] In the following embodiments, the TPU was purchased from Yantai Wanhua, and its brand name was WHT-1565IC;

[0052] CPVC has a degree of polymerization of 1150 and a chlorine content of 67%.

[0053] The chemical formula of polyphosphononitrile is [NPR1R2]n, where R1 is p-methylphenoxy, R2 is also p-methylphenoxy, and n is 200;

[0054] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168, wherein the weight ratio of antioxidant 1010 to antioxidant 168 is 1:2;

[0055] The lubricant is polyethylene wax.

[0056] The amounts of each raw material added in Examples 1-5 and Comparative Examples 1-2 were weighed according to Table 1 below (the table shows the parts by weight).

[0057] Table 1

[0058] TPU 66 68 72 76 78 CPVC 30 27 22 17 14 Polyphosphazene 0.5 1 1.25 1.5 1.7 Conductive carbon black 2.4 2.9 3.5 4.2 5 graphene 0.5 0.4 0.35 0.3 0.2 antioxidants 0.3 0.3 0.3 0.3 0.3 lubricant 0.3 0.4 0.6 0.7 0.8

[0059] Example 1

[0060] (1) Weigh the raw materials according to Table 1, and then dehumidify each raw material component;

[0061] (2) Polyphosphazene is uniformly stirred in CPVC to obtain a first mixture; graphene is uniformly dispersed in conductive carbon black to obtain a second mixture; antioxidant and lubricant are uniformly dispersed in a portion of TPU (5 parts by weight) to obtain a third mixture;

[0062] (3) The first mixture, the second mixture, the third mixture and the remaining TPU are stirred evenly, and then granulated by co-extrusion at 170°C and 20r / min to obtain TPU roller tube material A1 for underground coal mines.

[0063] Example 2

[0064] (1) Weigh the raw materials according to Table 1, and then dehumidify each raw material component;

[0065] (2) Polyphosphazene is uniformly stirred in CPVC to obtain a first mixture; graphene is uniformly dispersed in conductive carbon black to obtain a second mixture; antioxidant and lubricant are uniformly dispersed in a portion of TPU (5 parts by weight) to obtain a third mixture;

[0066] (3) The first mixture, the second mixture, the third mixture and the remaining TPU are stirred evenly, and then granulated by co-extrusion at 170°C and 20r / min to obtain TPU roller tube material A2 for underground coal mines.

[0067] Example 3

[0068] (1) Weigh the raw materials according to Table 1, and then dehumidify each raw material component;

[0069] (2) Polyphosphazene is uniformly stirred in CPVC to obtain a first mixture; graphene is uniformly dispersed in conductive carbon black to obtain a second mixture; antioxidant and lubricant are uniformly dispersed in a portion of TPU (5 parts by weight) to obtain a third mixture;

[0070] (3) The first mixture, the second mixture, the third mixture and the remaining TPU are stirred evenly, and then granulated by co-extrusion at 170°C and 20r / min to obtain TPU roller tube material A3 for underground coal mines.

[0071] Example 4

[0072] (1) Weigh the raw materials according to Table 1, and then dehumidify each raw material component;

[0073] (2) Polyphosphazene is uniformly stirred in CPVC to obtain a first mixture; graphene is uniformly dispersed in conductive carbon black to obtain a second mixture; antioxidant and lubricant are uniformly dispersed in a portion of TPU (5 parts by weight) to obtain a third mixture;

[0074] (3) The first mixture, the second mixture, the third mixture and the remaining TPU are stirred evenly, and then granulated by co-extrusion at 170°C and 20r / min to obtain TPU roller tube material A4 for underground coal mines.

[0075] Example 5

[0076] (1) Weigh the raw materials according to Table 1, and then dehumidify each raw material component;

[0077] (2) Polyphosphazene is uniformly stirred in CPVC to obtain a first mixture; graphene is uniformly dispersed in conductive carbon black to obtain a second mixture; antioxidant and lubricant are uniformly dispersed in a portion of TPU (5 parts by weight) to obtain a third mixture;

[0078] (3) The first mixture, the second mixture, the third mixture and the remaining TPU are stirred evenly, and then granulated by co-extrusion at 170°C and 20r / min to obtain TPU roller tube material A5 for underground coal mines.

[0079] Comparative Example 1

[0080] The method described in Example 2 was implemented, except that polyphosphononitrile was not added (it was replaced with an equal amount of CPVC), resulting in TPU roller tube material D1.

[0081] That is, weigh the following raw materials: 68 parts by weight of thermoplastic polyurethane, 28 parts by weight of CPVC, 2.9 parts by weight of conductive carbon black, 0.4 parts by weight of graphene, 0.3 parts by weight of antioxidant and 0.4 parts by weight of lubricant.

[0082] Comparative Example 2

[0083] The method described in Example 2 was implemented, except that graphene was not added (it was replaced with an equal amount of conductive carbon black), resulting in TPU roller tube material D2.

[0084] That is, weigh the following raw materials: 68 parts by weight of thermoplastic polyurethane, 27 parts by weight of chlorinated polyvinyl chloride, 1.0 part by weight of polyphosphazene, 3.3 parts by weight of conductive carbon black, 0.3 parts by weight of antioxidant and 0.4 parts by weight of lubricant.

[0085] Test Example 1

[0086] The yield strength, elongation at break, Vicat softening point, Akron abrasion, flame retardant oxygen index, and surface resistivity of the TPU idler roller tube materials prepared in Examples 1-5 and Comparative Examples 1-2 were tested respectively, and the results are shown in Table 2. The performance indicators of the TPU idler roller tube materials used in underground coal mines are shown in Table 3.

[0087] The test method for yield strength is GB / T1040.1-2018;

[0088] The test method for elongation at break is GB / T1040.1-2018;

[0089] The test method for Vicat softening point is GB / T1633-2000;

[0090] The test method for Akron wear is GB / T1689-2014;

[0091] The test method for the flame retardant oxygen index is GB / T 2406.2-2009;

[0092] The test method for surface resistivity is MT / T 113-1995.

[0093] Table 2

[0094] Yield strength / MPa 9.5 9.2 9.0 8.5 8.2 9.1 9.3 Elongation at break / % 710 755 830 875 950 760 733 Vicat softening point / °C 72 71 70.5 67 65.5 70 71.5 Akron wear / % 0.3 0.27 0.26 0.23 0.21 0.42 0.25 Flame retardant oxygen index 35 39 37 38 36 24 38 Surface resistance / Ω <![CDATA[7*10 6 ]]> <![CDATA[9*10 6 ]]> <![CDATA[3*10 7 ]]> <![CDATA[8*10 7 ]]> <![CDATA[5*10 6 ]]> <![CDATA[6*10 6 ]]> <![CDATA[2*10 9 ]]>

[0095] Table 3

[0096] Yield strength MPa ≥8.0 Elongation at break ％ ≧700 Vika softening ℃ ≥65 Akron wear <![CDATA[cm 3 ]]> ≤0.3 Flame retardant rating Oxygen Index ≥35 Surface resistance Ω <![CDATA[≤2*10 8 ]]>

[0097] As can be seen from Table 1, the mechanical properties, wear resistance, and antistatic properties of the TPU roller tube materials for underground coal mines prepared in Examples 1-5 of this invention all meet the performance requirements for TPU roller tube materials for underground coal mines. This indicates that by utilizing a highly efficient CPVC + polyphosphazene flame retardant, and simultaneously utilizing a combination of conductive carbon black + graphene, this invention achieves the system's functionality while ensuring the excellent elasticity and wear resistance of the TPU material.

[0098] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A TPU idler roller tube material for use in underground coal mines, characterized in that, Based on 100 parts by weight of the total weight of the TPU roller tube material, the TPU roller tube material contains: 65-80 parts by weight of thermoplastic polyurethane, 14-30 parts by weight of chlorinated polyvinyl chloride, 0.5-2 parts by weight of polyphosphonic acrylonitrile, 2-5 parts by weight of conductive carbon black, 0.2-0.5 parts by weight of graphene, 0.1-0.4 parts by weight of antioxidant, and 0.3-0.8 parts by weight of lubricant; The chlorinated polyvinyl chloride contains 65-70% chlorine. The degree of polymerization of the chlorinated polyvinyl chloride is 1000~1350; The polyphosphazene has a structure as shown in structural formula (Ⅰ): （Ⅰ） Wherein, R1 is p-methylphenoxy, R2 is p-methylphenoxy, and n is 200.

2. The TPU idler roller tube material for underground coal mines according to claim 1, characterized in that, The antioxidant is antioxidant 1010 and / or antioxidant 168.

3. The TPU idler roller tube material for underground coal mines according to claim 1, characterized in that, The lubricant is polyethylene wax.

4. A method for preparing the TPU idler roller body material for underground coal mines as described in any one of claims 1-3, characterized in that, The method includes: Chlorinated polyvinyl chloride, polyphosphazene, conductive carbon black, graphene, antioxidant, lubricant and thermoplastic polyurethane are mixed and then co-extruded and granulated.

5. The method according to claim 4, characterized in that, The process of mixing chlorinated polyvinyl chloride, polyphosphazene, conductive carbon black, graphene, antioxidant, lubricant, and thermoplastic polyurethane includes: Polyphosphazene and chlorinated polyvinyl chloride are mixed to obtain a first mixture; Graphene was mixed with conductive carbon black to obtain a second mixture; Antioxidants, lubricants, and a portion of thermoplastic polyurethane are mixed to obtain a third mixture; The first mixture, the second mixture, the third mixture, and the remaining thermoplastic polyurethane are mixed.

6. The method according to claim 4, characterized in that, The temperature of the blend extrusion granulation is 160~180℃, and the rotation speed is 10~30r / min.

7. The TPU idler roller tube material for underground coal mines prepared by the method according to any one of claims 4-6.

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