Flame-retardant PVC material for drag chain cables and method for producing the same

Abstract

The present application relates to a kind of drag chain cable with flame-retardant PVC material and its preparation method, belong to cable material technical field;The present application is prepared by a kind of flame-retardant compatibilizer, the good compatibility of the flame-retardant compatibilizer in tri-chloro-phenyl structure and PVC phase, and the siloxane structure in it can crosslink with the siloxane in modified TPU masterbatch in heat treatment crosslinking process and improve the compatibility of TPU phase, the present application innovatively flame-retardant component as the third component compatibilizer, not only solve the uneven problem of dispersion of flame-retardant component in PVC / TPU composite material, also effectively improve the interface bonding force of PVC phase and TPU phase, improve the modification effect of PVC of TPU, so that the flame-retardant PVC material obtained finally can have more excellent dynamic adaptability and environmental tolerance.

Description

Technical Field

[0001] This invention belongs to the field of cable material technology, specifically, it relates to a flame-retardant PVC material for drag chain cables and its preparation method. Background Technology

[0002] Drag chain cables need to reciprocate at high frequency and with a small radius within a closed track, which places extremely stringent requirements on the flexibility and bending fatigue resistance of the cable's outer sheath material.

[0003] PVC (polyvinyl chloride) resin has long been the mainstream material for cable sheaths due to its low cost and ease of processing. However, when used in the outer sheath of drag chain cables, PVC's poor elastic recovery often fails to meet the dynamic requirements of high-frequency bending. To improve the bending fatigue life of PVC, the industry typically modifies it by blending it with TPU (thermoplastic polyurethane). However, PVC and TPU have poor compatibility, requiring the addition of compatibilizers during blending. Furthermore, to meet mandatory safety standards for cables, flame retardants must be added to ensure the cable's flame retardancy. These added flame retardants are difficult to disperse in incompatible two-phase matrices and further damage the already fragile two-phase interface, leading to a significant decrease in the material's mechanical properties, especially dynamic fatigue performance. To address these technical shortcomings, this invention provides a flame-retardant PVC material for drag chain cables and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a flame-retardant PVC material for drag chain cables and its preparation method, in order to solve the problems mentioned in the background art.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A flame-retardant PVC material for drag chain cables is formed by mixing and granulating modified TPU masterbatch and flame-retardant PVC masterbatch, wherein the mass ratio of modified TPU masterbatch to flame-retardant PVC masterbatch is 20-30:80-90. The flame-retardant PVC masterbatch contains the following raw materials in parts by mass: 100 parts PVC resin, 30-60 parts plasticizer, 2-5 parts stabilizer, 0.5-2 parts lubricant, 15-30 parts filler, 0.3-0.8 parts antioxidant, and 15-20 parts flame-retardant compatibilizer.

[0007] Furthermore, the modified TPU masterbatch comprises the following raw materials in parts by weight: 100 parts TPU resin, 1.5 to 2.5 parts silane coupling agent, 0.3 to 0.8 parts lubricant, and 0.1 to 0.5 parts antioxidant.

[0008] Furthermore, the plasticizer is a phthalate plasticizer.

[0009] Furthermore, the stabilizer is a calcium-zinc composite stabilizer.

[0010] Furthermore, the lubricant is one of calcium stearate or polyethylene wax.

[0011] Furthermore, the filler is nano-silica.

[0012] Furthermore, the silane coupling agent is silane coupling agent KH-560.

[0013] Furthermore, the antioxidant is one or more of antioxidant 1010, antioxidant 1035, and antioxidant 168.

[0014] Furthermore, the flame retardant compatibilizer is prepared by the following steps:

[0015] S1. An esterification reaction is carried out between bis(1-chloro-2-propyl) phosphate and 3,4,5-trichlorophenol to obtain a flame retardant;

[0016]

[0017]

[0018] The reaction process is as follows: bis(1-chloro-2-propyl)phosphate and acetonitrile are mixed in a reaction vessel. After stirring, thionyl chloride is added dropwise to the reaction vessel. After the addition is complete, the reaction is carried out at a temperature of 40-60℃ for 2-3 hours. Then, the mixture is cooled to room temperature and 3,4,5-trichlorophenol and triethylamine are added to the system. The reaction is carried out at room temperature for 8-12 hours. After the reaction is completed, the reaction solution is poured into deionized water. After filtering to separate the solid, the obtained solid is washed with deionized water and dried to obtain the flame retardant.

[0019] S2. A flame retardant compatibilizer is obtained by reacting the flame retardant with (N,N-dimethyl-3-aminopropyl)trimethoxysilane as a quaternary ammonium salt.

[0020]

[0021] The reaction process is as follows: the flame retardant, (N,N-dimethyl-3-aminopropyl)trimethoxysilane, and acetonitrile are mixed in a reaction vessel, and the mixture is stirred and reacted at a temperature of 40-60℃ for 6-12 hours. After the reaction is completed, the solvent is removed by rotary evaporation of the reaction solution, and the remaining solid is recrystallized from petroleum ether to obtain the flame retardant compatibilizer.

[0022] A method for preparing flame-retardant PVC material for drag chain cables includes the following steps:

[0023] The first step is to mix TPU resin, silane coupling agent, lubricant, and antioxidant, and then melt extrude and granulate to obtain modified TPU masterbatch;

[0024] The second step involves mixing PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame retardant compatibilizer, followed by melt extrusion granulation to obtain flame retardant PVC masterbatch.

[0025] The third step involves mixing modified TPU masterbatch with flame-retardant PVC masterbatch, then melting and extruding the mixture to obtain a cable blank. The cable blank is then heat-treated and cross-linked to obtain flame-retardant PVC material for drag chain cables.

[0026] Furthermore, the temperature for melt extrusion granulation of the modified TPU masterbatch in the first step is 180–200°C.

[0027] Furthermore, the temperature for melt extrusion granulation of the flame-retardant PVC masterbatch in the second step is 170–180°C.

[0028] Furthermore, in the third step, the temperature for melt extrusion plasticization after mixing the modified TPU masterbatch with the flame-retardant PVC masterbatch is 180–190°C.

[0029] Furthermore, the heat treatment crosslinking conditions described in the third step are treatment in warm water at a temperature of 60–80°C for 4–8 hours.

[0030] The beneficial effects of this invention are:

[0031] This invention prepares a flame-retardant compatibilizer. The trichlorophenyl structure in this flame-retardant compatibilizer has good compatibility with the PVC phase, while the siloxane structure can crosslink with the siloxane in the modified TPU masterbatch during heat treatment crosslinking, thereby improving the compatibility with the TPU phase. This invention innovatively uses the flame-retardant component as a third-component compatibilizer, which not only solves the problem of uneven dispersion of the flame-retardant component in the PVC / TPU composite material, but also effectively improves the interfacial bonding force between the PVC phase and the TPU phase, and enhances the modification effect of TPU on PVC. This results in a flame-retardant PVC material with better dynamic adaptability and environmental resistance.

[0032] The flame retardant compatibilizer designed in this invention integrates the flame retardant effects of three flame retardant elements: phosphorus, nitrogen, and silicon, achieving integrated gas-phase and condensed-phase synergistic flame retardancy, resulting in a more efficient flame retardant enhancement effect.

[0033] The flame retardant compatibilizer designed in this invention also contains a positively charged quaternary ammonium salt structure. The quaternary ammonium salt structure can form conductive ion channels in the composite material, effectively eliminating the static charge accumulated in the high-speed reciprocating motion of the drag chain cable, avoiding electrostatic discharge, and improving the safety performance of the drag chain cable. Attached Figure Description

[0034] Figure 1 The image shows the infrared spectrum of the flame retardant compatibilizer in Example 1 of this invention. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] A flame-retardant PVC material for drag chain cables is formed by mixing and granulating modified TPU masterbatch and flame-retardant PVC masterbatch, with a mass ratio of modified TPU masterbatch to flame-retardant PVC masterbatch of 20:80. The flame-retardant PVC masterbatch contains the following raw materials in parts by mass: 100 parts PVC resin, 30 parts plasticizer, 2 parts stabilizer, 0.5 parts lubricant, 15 parts filler, 0.3 parts antioxidant, and 15 parts flame-retardant compatibilizer. The modified TPU masterbatch contains the following raw materials in parts by mass: 100 parts TPU resin, 1.5 parts silane coupling agent, 0.3 parts lubricant, and 0.1 parts antioxidant.

[0038] In this embodiment, the plasticizer used is di(2-ethylhexyl) phthalate, the stabilizer used is calcium-zinc stabilizer CZ113, the lubricant used is calcium stearate, the filler used is nano-silica, the antioxidant used is antioxidant 1010, the silane coupling agent used is silane coupling agent KH-560, and the flame retardant compatibilizer used is prepared by the following steps:

[0039] S1. Mix 25 parts of bis(1-chloro-2-propyl) phosphate and 200 parts of acetonitrile in a reaction vessel. After stirring, add 12 parts of thionyl chloride dropwise to the reaction vessel. After the addition is complete, react at 40°C for 3 hours. Then cool to room temperature and add 20 parts of 3,4,5-trichlorophenol and 12 parts of triethylamine to the system. React at room temperature for 12 hours. After the reaction is complete, pour the reaction solution into deionized water. After filtering to separate the solid, wash the obtained solid with deionized water and dry it to obtain the flame retardant.

[0040] S2. Mix 32 parts of flame retardant, 35 parts of (N,N-dimethyl-3-aminopropyl)trimethoxysilane and 180 parts of acetonitrile in a reaction vessel. After stirring, react at 40°C for 12 hours. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution. The remaining solid is recrystallized from petroleum ether to obtain the flame retardant compatibilizer.

[0041] A method for preparing flame-retardant PVC material for drag chain cables includes the following steps:

[0042] Step 1: Mix TPU resin, silane coupling agent, lubricant, and antioxidant, then melt-extrude and granulate at 180℃ to obtain modified TPU masterbatch;

[0043] The second step involves mixing PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame retardant compatibilizer, and then melting and extruding the mixture at 170°C to obtain flame retardant PVC masterbatch.

[0044] The third step involves mixing the modified TPU masterbatch with the flame-retardant PVC masterbatch and then melting and extruding the mixture at 180°C to obtain a cable blank. The cable blank is then treated in warm water at 60°C for 8 hours to obtain the flame-retardant PVC material for drag chain cables.

[0045] Example 2

[0046] A flame-retardant PVC material for drag chain cables is formed by mixing and granulating modified TPU masterbatch and flame-retardant PVC masterbatch, with a mass ratio of modified TPU masterbatch to flame-retardant PVC masterbatch of 22.5:82.5. The flame-retardant PVC masterbatch contains the following raw materials in parts by mass: 100 parts PVC resin, 37.5 parts plasticizer, 2.75 parts stabilizer, 0.875 parts lubricant, 18.75 parts filler, 0.425 parts antioxidant, and 16.25 parts flame-retardant compatibilizer. The modified TPU masterbatch contains the following raw materials in parts by mass: 100 parts TPU resin, 1.75 parts silane coupling agent, 0.425 parts lubricant, and 0.2 parts antioxidant.

[0047] In this embodiment, the plasticizer used is diisononyl phthalate, the stabilizer used is calcium-zinc stabilizer CZ113, the lubricant used is calcium stearate, the filler used is nano-silica, the antioxidant used is antioxidant 1035, the silane coupling agent used is silane coupling agent KH-560, and the flame retardant compatibilizer used is prepared by the following steps:

[0048] S1. Mix 25 parts of bis(1-chloro-2-propyl) phosphate and 200 parts of acetonitrile in a reaction vessel. After stirring, add 12 parts of thionyl chloride dropwise to the reaction vessel. After the addition is complete, react at 40°C for 3 hours. Then cool to room temperature and add 20 parts of 3,4,5-trichlorophenol and 12 parts of triethylamine to the system. React at room temperature for 12 hours. After the reaction is complete, pour the reaction solution into deionized water. After filtering to separate the solid, wash the obtained solid with deionized water and dry it to obtain the flame retardant.

[0049] S2. Mix 32 parts of flame retardant, 35 parts of (N,N-dimethyl-3-aminopropyl)trimethoxysilane and 180 parts of acetonitrile in a reaction vessel. After stirring, react at 40°C for 12 hours. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution. The remaining solid is recrystallized from petroleum ether to obtain the flame retardant compatibilizer.

[0050] A method for preparing flame-retardant PVC material for drag chain cables includes the following steps:

[0051] Step 1: Mix TPU resin, silane coupling agent, lubricant, and antioxidant, then melt extrude and granulate at 185℃ to obtain modified TPU masterbatch;

[0052] The second step involves mixing PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame retardant compatibilizer, and then melt-extruding and granulating the mixture at a temperature of 172.5℃ to obtain flame retardant PVC masterbatch.

[0053] The third step involves mixing the modified TPU masterbatch with the flame-retardant PVC masterbatch and then melting and extruding the mixture at 182.5℃ to obtain a cable blank. The cable blank is then treated in warm water at 65℃ for 7 hours to obtain flame-retardant PVC material for drag chain cables.

[0054] Example 3

[0055] A flame-retardant PVC material for drag chain cables is formed by mixing and granulating modified TPU masterbatch and flame-retardant PVC masterbatch, with a mass ratio of modified TPU masterbatch to flame-retardant PVC masterbatch of 25:85. The flame-retardant PVC masterbatch contains the following raw materials in parts by mass: 100 parts PVC resin, 45 parts plasticizer, 3.5 parts stabilizer, 1.25 parts lubricant, 22.5 parts filler, 0.55 parts antioxidant, and 17.5 parts flame-retardant compatibilizer. The modified TPU masterbatch contains the following raw materials in parts by mass: 100 parts TPU resin, 2 parts silane coupling agent, 0.55 parts lubricant, and 0.3 parts antioxidant.

[0056] In this embodiment, the plasticizer used is diisodecyl phthalate, the stabilizer used is calcium-zinc stabilizer CZ116, the lubricant used is polyethylene wax, the filler used is nano-silica, the antioxidant used is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 4:1, the silane coupling agent used is silane coupling agent KH-560, and the flame retardant compatibilizer used is prepared by the following steps:

[0057] S1. Mix 25 parts of bis(1-chloro-2-propyl) phosphate and 200 parts of acetonitrile in a reaction vessel. After stirring, add 12 parts of thionyl chloride dropwise to the reaction vessel. After the addition is complete, react at 50°C for 2.5 h. Then cool to room temperature and add 20 parts of 3,4,5-trichlorophenol and 12 parts of triethylamine to the system. React at room temperature for 10 h. After the reaction is complete, pour the reaction solution into deionized water. After filtering to separate the solid, wash the obtained solid with deionized water and dry to obtain the flame retardant.

[0058] S2. Mix 32 parts of flame retardant, 35 parts of (N,N-dimethyl-3-aminopropyl)trimethoxysilane and 180 parts of acetonitrile in a reaction vessel, start stirring and react at 50°C for 9 hours. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution, and the remaining solid is recrystallized from petroleum ether to obtain the flame retardant compatibilizer.

[0059] A method for preparing flame-retardant PVC material for drag chain cables includes the following steps:

[0060] Step 1: Mix TPU resin, silane coupling agent, lubricant, and antioxidant, then melt-extrude and granulate at 190℃ to obtain modified TPU masterbatch;

[0061] The second step involves mixing PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame retardant compatibilizer, and then melting and extruding the mixture at 175°C to obtain flame retardant PVC masterbatch.

[0062] The third step involves mixing the modified TPU masterbatch with the flame-retardant PVC masterbatch and then melting and extruding the mixture at 185°C to obtain a cable blank. The cable blank is then treated in warm water at 70°C for 6 hours to obtain the flame-retardant PVC material for drag chain cables.

[0063] Example 4

[0064] A flame-retardant PVC material for drag chain cables is formed by mixing and granulating modified TPU masterbatch and flame-retardant PVC masterbatch, with a mass ratio of modified TPU masterbatch to flame-retardant PVC masterbatch of 27.5:87.5. The flame-retardant PVC masterbatch contains the following raw materials in parts by mass: 100 parts PVC resin, 52.5 parts plasticizer, 4.25 parts stabilizer, 1.625 parts lubricant, 26.25 parts filler, 0.675 parts antioxidant, and 18.75 parts flame-retardant compatibilizer. The modified TPU masterbatch contains the following raw materials in parts by mass: 100 parts TPU resin, 2.25 parts silane coupling agent, 0.675 parts lubricant, and 0.4 parts antioxidant.

[0065] In this embodiment, the plasticizer used is diisononyl phthalate, the stabilizer used is calcium-zinc stabilizer CZ116, the lubricant used is polyethylene wax, the filler used is nano-silica, the antioxidant used is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 5:1, the silane coupling agent used is silane coupling agent KH-560, and the flame retardant compatibilizer used is prepared by the following steps:

[0066] S1. Mix 25 parts of bis(1-chloro-2-propyl) phosphate and 200 parts of acetonitrile in a reaction vessel. After stirring, add 12 parts of thionyl chloride dropwise to the reaction vessel. After the addition is complete, react at 50°C for 2.5 h. Then cool to room temperature and add 20 parts of 3,4,5-trichlorophenol and 12 parts of triethylamine to the system. React at room temperature for 10 h. After the reaction is complete, pour the reaction solution into deionized water. After filtering to separate the solid, wash the obtained solid with deionized water and dry to obtain the flame retardant.

[0067] S2. Mix 32 parts of flame retardant, 35 parts of (N,N-dimethyl-3-aminopropyl)trimethoxysilane and 180 parts of acetonitrile in a reaction vessel, start stirring and react at 50°C for 9 hours. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution, and the remaining solid is recrystallized from petroleum ether to obtain the flame retardant compatibilizer.

[0068] A method for preparing flame-retardant PVC material for drag chain cables includes the following steps:

[0069] Step 1: Mix TPU resin, silane coupling agent, lubricant, and antioxidant, then melt-extrude and granulate at 195℃ to obtain modified TPU masterbatch;

[0070] The second step involves mixing PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame retardant compatibilizer, and then melt-extruding and granulating the mixture at a temperature of 177.5℃ to obtain flame retardant PVC masterbatch.

[0071] The third step involves mixing the modified TPU masterbatch with the flame-retardant PVC masterbatch and then melting and extruding the mixture at a temperature of 187.5℃ to obtain a cable blank. The cable blank is then treated in warm water at a temperature of 75℃ for 5 hours to obtain flame-retardant PVC material for drag chain cables.

[0072] Example 5

[0073] A flame-retardant PVC material for drag chain cables is formed by mixing and granulating modified TPU masterbatch and flame-retardant PVC masterbatch, with a mass ratio of modified TPU masterbatch to flame-retardant PVC masterbatch of 30:90. The flame-retardant PVC masterbatch contains the following raw materials in parts by mass: 100 parts PVC resin, 60 parts plasticizer, 5 parts stabilizer, 2 parts lubricant, 30 parts filler, 0.8 parts antioxidant, and 20 parts flame-retardant compatibilizer. The modified TPU masterbatch contains the following raw materials in parts by mass: 100 parts TPU resin, 2.5 parts silane coupling agent, 0.8 parts lubricant, and 0.5 parts antioxidant.

[0074] In this embodiment, the plasticizer used is diisodecyl phthalate, the stabilizer used is calcium-zinc stabilizer CZ116, the lubricant used is polyethylene wax, the filler used is nano-silica, the antioxidant used is a mixture of antioxidant 1035 and antioxidant 168 in a mass ratio of 3:1, the silane coupling agent used is silane coupling agent KH-560, and the flame retardant compatibilizer used is prepared by the following steps:

[0075] S1. Mix 25 parts of bis(1-chloro-2-propyl) phosphate and 200 parts of acetonitrile in a reaction vessel. After stirring, add 12 parts of thionyl chloride dropwise to the reaction vessel. After the addition is complete, react at 60°C for 2 hours. Then cool to room temperature and add 20 parts of 3,4,5-trichlorophenol and 12 parts of triethylamine to the system. React at room temperature for 8 hours. After the reaction is complete, pour the reaction solution into deionized water. After filtering to separate the solid, wash the obtained solid with deionized water and dry it to obtain the flame retardant.

[0076] S2. Mix 32 parts of flame retardant, 35 parts of (N,N-dimethyl-3-aminopropyl)trimethoxysilane and 180 parts of acetonitrile in a reaction vessel. After stirring, react at 60°C for 6 hours. After the reaction is completed, remove the solvent by rotary evaporation of the reaction solution. The remaining solid is recrystallized from petroleum ether to obtain the flame retardant compatibilizer.

[0077] A method for preparing flame-retardant PVC material for drag chain cables includes the following steps:

[0078] Step 1: Mix TPU resin, silane coupling agent, lubricant, and antioxidant, then melt-extrude and granulate at 200℃ to obtain modified TPU masterbatch;

[0079] The second step involves mixing PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame retardant compatibilizer, and then melting and extruding the mixture at 180°C to obtain flame retardant PVC masterbatch.

[0080] The third step involves mixing the modified TPU masterbatch with the flame-retardant PVC masterbatch and then melting and extruding the mixture at 190°C to obtain a cable blank. The cable blank is then treated in warm water at 80°C for 4 hours to obtain the flame-retardant PVC material for drag chain cables.

[0081] Comparative Example 1

[0082] The difference between this comparative example and Example 1 is that, instead of preparing a flame retardant compatibilizer separately, an equal mass of bis(1-chloro-2-propyl) phosphate is used to replace the flame retardant compatibilizer in the raw materials.

[0083] The flame retardant compatibilizer obtained in Example 1 was characterized by infrared spectroscopy. Infrared spectroscopy was performed on a Fourier transform infrared spectrometer after potassium bromide tableting. Figure 1As shown, in the range of 3100–3000 cm -1 There are hydrocarbon absorption peaks on the benzene ring at 2950–2850 cm⁻¹. -1 An alkyl absorption peak appears at 1300–1150 cm⁻¹. -1 An absorption peak for phosphorus-oxygen double bonds appears at 1100–1000 cm⁻¹. -1 A siloxane absorption peak appears at 950–750 cm⁻¹. -1 The presence of carbon-chlorine bond absorption peaks indicates that the preparation method of this invention can produce flame retardant compatibilizers.

[0084] The performance of the flame-retardant PVC material for the drag chain cables in Examples 1-5 and Comparative Example 1 was tested. The tensile strength and elongation at break of each component sample were tested according to national standard GB / T 1040.2-2006; the oxygen limiting index of each component sample was tested according to national standard GB / T 2406.2-2009; the volume resistivity of each component sample was tested according to national standard GB / T 31838.2-2019; and the flexural fatigue life of each component sample was tested according to industry standard JB / T 10696.3-2007. The test results are shown in Table 1.

[0085] Table 1

[0086]

[0087] As can be seen from Table 1, due to the improved compatibility, the flame-retardant PVC materials for drag chain cables in Examples 1-5 have better mechanical properties, toughness, and flame-retardant properties. Although more flame-retardant components were added in Comparative Example 1, the uneven distribution of the flame-retardant components ultimately resulted in a lower limiting oxygen index than the flame-retardant PVC materials for drag chain cables in Examples 1-5. Moreover, the addition of flame retardants further reduced the interfacial compatibility between the PVC phase and the TPU phase, leading to a significant reduction in bending fatigue life.

[0088] The present invention provides a detailed description of a flame-retardant PVC material for drag chain cables and its preparation method. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combination method. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A flame-retardant PVC material for drag chain cables, characterized in that, It is made by mixing and granulating modified TPU masterbatch and flame-retardant PVC masterbatch. The flame-retardant PVC masterbatch contains the following raw materials: PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame-retardant compatibilizer. The flame retardant compatibilizer is prepared by the following steps: S1. Bis(1-chloro-2-propyl)phosphate and acetonitrile are mixed in a reaction vessel. After stirring, thionyl chloride is added dropwise to the reaction vessel. After the addition is complete, the reaction is carried out at a temperature of 40-60℃ for 2-3 hours. Then, the mixture is cooled to room temperature and 3,4,5-trichlorophenol and triethylamine are added to the system. The reaction is carried out at room temperature for 8-12 hours. After the reaction is completed, the reaction solution is poured into deionized water. After filtering to separate the solid, the obtained solid is washed with deionized water and dried to obtain the flame retardant. S2. The flame retardant, (N,N-dimethyl-3-aminopropyl)trimethoxysilane and acetonitrile are mixed in a reaction vessel. After stirring, the mixture is reacted at 40-60℃ for 6-12 hours. After the reaction is completed, the solvent is removed by rotary evaporation of the reaction solution. The remaining solid is recrystallized from petroleum ether to obtain the flame retardant compatibilizer. The flame-retardant PVC masterbatch comprises the following parts by weight of raw materials: 100 parts PVC resin, 30-60 parts plasticizer, 2-5 parts stabilizer, 0.5-2 parts lubricant, 15-30 parts filler, 0.3-0.8 parts antioxidant, and 15-20 parts flame-retardant compatibilizer; the modified TPU masterbatch comprises the following parts by weight of raw materials: 100 parts TPU resin, 1.5-2.5 parts silane coupling agent, 0.3-0.8 parts lubricant, and 0.1-0.5 parts antioxidant; The plasticizer is a phthalate plasticizer, the stabilizer is a calcium-zinc composite stabilizer, the lubricant is one of calcium stearate and polyethylene wax, the filler is nano silica, the antioxidant is one or more of antioxidant 1010, antioxidant 1035 and antioxidant 168, and the silane coupling agent is silane coupling agent KH-560.

2. A method for preparing flame-retardant PVC material for drag chain cables as described in claim 1, characterized in that, Includes the following steps: The first step is to mix TPU resin, silane coupling agent, lubricant, and antioxidant, and then melt extrude and granulate to obtain modified TPU masterbatch; The second step involves mixing PVC resin, plasticizer, stabilizer, lubricant, filler, antioxidant, and flame retardant compatibilizer, followed by melt extrusion granulation to obtain flame retardant PVC masterbatch. The third step involves mixing modified TPU masterbatch with flame-retardant PVC masterbatch, then melting and extruding the mixture to obtain a cable blank. The cable blank is then heat-treated and cross-linked to obtain flame-retardant PVC material for drag chain cables.

3. The method for preparing a flame-retardant PVC material for drag chain cables according to claim 2, characterized in that, The temperature for melt extrusion granulation of the modified TPU masterbatch in the first step is 180–200°C.

4. The method for preparing a flame-retardant PVC material for drag chain cables according to claim 2, characterized in that, The temperature for melt extrusion granulation of the flame-retardant PVC masterbatch in the second step is 170–180°C.

5. The method for preparing a flame-retardant PVC material for drag chain cables according to claim 2, characterized in that, The mass ratio of the modified TPU masterbatch to the flame-retardant PVC masterbatch in the third step is 20-30:80-90.

6. The method for preparing a flame-retardant PVC material for drag chain cables according to claim 2, characterized in that, The temperature for melt extrusion plasticization of the modified TPU masterbatch and flame-retardant PVC masterbatch in the third step is 180-190℃.

7. The method for preparing a flame-retardant PVC material for drag chain cables according to claim 2, characterized in that, The heat treatment crosslinking conditions described in the third step are: treatment in warm water at 60–80°C for 4–8 hours.

Images