A high-barrier, wear-resistant, and flame-retardant CPVC cable protection material and its preparation method

Abstract

This invention belongs to the technical field of polymer cable protection materials, specifically disclosing a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material and its preparation method. The method involves first premixing CPVC resin with basic additives, then pre-wetting a barrier material with a layered acid-capturing structure using a first-part epoxidized wetting component, followed by CPVC pre-gelation treatment. Subsequently, the pre-gelled material is cooled, and then organically coated phosphorus-nitrogen flame-retardant microcapsules, a sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc, and the remaining epoxidized wetting component are premixed and added. Finally, the mixture is extruded and granulated. This method can reduce the thermal shear damage of the flame-retardant microcapsules and sheet-like wear-resistant barrier material during the high-temperature pre-gelation stage, improving the retention of flame-retardant and barrier properties after material wear.

Description

Technical Field

[0001] This invention relates to the technical field of polymer cable protection materials, and in particular to a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material and its preparation method. Background Technology

[0002] Chlorinated polyvinyl chloride (CPVC) is a thermoplastic resin obtained by further chlorination of polyvinyl chloride. It possesses good heat resistance, corrosion resistance, flame retardancy, and mechanical properties, and is widely used in power cable protection pipes, communication pipelines, chemical pipelines, and buried pipes. Compared to ordinary polyvinyl chloride, CPVC has improved temperature resistance and flame retardancy, making it suitable for complex environments such as cable laying, underground pipe networks, and outdoor engineering.

[0003] Existing CPVC cable protection materials are typically obtained by adding stabilizers, lubricants, impact modifiers, fillers, flame retardants, and other additives to CPVC resin, followed by mixing, plasticizing, extrusion, or granulation. For example, existing technologies have disclosed methods for preparing CPVC power cable protection pipes using chlorinated polyvinyl chloride resin, stabilizers, lubricants, heat resistant agents, anti-aging agents, modifiers, antioxidants, and inorganic fillers as raw materials. Other technical solutions improve the flame retardancy, abrasion resistance, and mechanical properties of cable protection pipes by adding flame retardants, fillers, and lubricating impact modifiers to the PVC or PVC-C system.

[0004] However, in actual use, cable protection materials often undergo external wear and tear from handling, dragging, cable pulling friction, backfill compaction, underground particle friction, and long-term service. For these materials, good initial flame retardant or initial barrier properties are insufficient to meet long-term service requirements. When the material surface is worn down, the original flame retardant and barrier components are prone to degradation due to surface structure damage, changes in dispersion, or interruption of functional pathways, leading to a decline in flame retardant and barrier properties. Especially after continuous friction or localized scratching of the outer wall of the cable protection conduit, the material surface's barrier ability against flames, oxygen, water vapor, or corrosive media may decrease, thus affecting the safety and service stability of the cable protection material.

[0005] Therefore, how to improve the flame retardant and barrier properties of CPVC cable protection materials after wear while maintaining their basic processing and mechanical properties is a technical problem that still needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned problems existing in the prior art and provide a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material and its preparation method, so that the obtained CPVC cable protection material maintains good processing performance and mechanical properties while retaining good flame-retardant performance and barrier performance after wear.

[0007] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material, comprising the following steps: S1. Chlorinated polyvinyl chloride resin is premixed with heat stabilizer, processing aid, lubricant, chlorinated polyethylene and core-shell impact modifier to obtain basic premix; S2. Add a first part of epoxidized wetting component and a barrier material with a layered acid trapping structure to the basic premix, and mix them at a temperature lower than the subsequent pregelation temperature, so that the barrier material with a layered acid trapping structure is wetted by the first part of epoxidized wetting component before the chlorinated polyvinyl chloride resin is pregelated, to obtain a pre-wetting acid trapping material. S3. The pre-wetting acid capture material is heated to the pre-gelling temperature and pre-gelled to form a pre-gelled matrix of chlorinated polyvinyl chloride resin, thus obtaining a pre-gelled material. S4. Cool the pregelated material to a post-addition temperature that is 16-28°C lower than the pregelation temperature to obtain a cooled pregelated material. S5. The organic-coated phosphorus-nitrogen flame-retardant microcapsules, the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc, and the remaining epoxidized wetting component are premixed to pre-wet the organic-coated phosphorus-nitrogen flame-retardant microcapsules and the sheet-like wear-resistant barrier material, thereby obtaining a post-added functional premix. S6. Add the post-added functional premix to the cooled pregelated material and mix it at a temperature and speed lower than that in step S3, so that the organic-coated phosphorus and nitrogen flame-retardant microcapsules and the sheet-like wear-resistant barrier material are dispersed in the cooled chlorinated polyvinyl chloride pregelated matrix to obtain a functionalized mixture. S7. Extrude and granulate the functionalized mixture to obtain the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material; Wherein, the first portion of the epoxidized wetting component accounts for 60% to 85% of the total weight of the epoxidized wetting component, and the remaining portion of the epoxidized wetting component accounts for 15% to 40% of the total weight of the epoxidized wetting component; Both the organically coated phosphorus and nitrogen flame-retardant microcapsules and the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc are added as functional premixes after the pregelation treatment in step S3, and do not participate in the pregelation treatment in step S3.

[0008] Through the above preparation method, the CPVC resin first forms a relatively uniform basic mixture with the basic additives and impact-modifying components, which is beneficial for establishing a continuous and stable resin support matrix in the subsequent pre-gelling stage. The first part, the epoxidized wetting component, first wets the barrier material with a layered acid-capturing structure, allowing the layered material to enter the base system and form a better dispersion state before the CPVC resin pre-gellest. CPVC may produce a small amount of acidic substances under heating and shearing conditions. The barrier material with a layered acid-capturing structure can adsorb, fix, or neutralize and buffer the acidic substances using its interlayer structure, hydroxyl sites, and basic sites. The epoxidized wetting component further improves the contact state between this type of layered material and the CPVC base system, making it less likely for acidic substances to accumulate in local areas. This makes the pre-gelling process more stable and reduces the impact of the local acidic environment on the stability of the CPVC continuous phase and the interface of subsequent functional components.

[0009] In the above process, the organically coated phosphorus-nitrogen flame-retardant microcapsules and the sheet-like abrasion-resistant barrier material containing hexagonal boron nitride and talc do not participate in the high-temperature pregelation treatment of CPVC. Instead, they are added as post-added functional premixes after the CPVC has formed a pregelated matrix and cooled down. In this way, the high-temperature pregelation stage is mainly used to form a continuous load-bearing matrix for CPVC, preventing the organically coated flame-retardant microcapsules and sheet-like abrasion-resistant barrier material from directly bearing the high-temperature, high-shear stress of this stage. While this treatment method superficially reduces the early mixing time of the functional components, it is more beneficial for protecting the integrity of the organic coating layer and the sheet-like structure, ensuring that the functional components enter the pregelated CPVC matrix, which already possesses a certain encapsulation and load-bearing capacity.

[0010] Cooling the pregelated material to a subsequent application temperature 16–28°C lower than the pregelation temperature creates a suitable entry window for functional components. On one hand, the cooled CPVC pregelated matrix still retains some encapsulation and dispersion capabilities, allowing it to accommodate subsequently added microcapsule flame-retardant components and sheet-like abrasion-resistant barrier components. On the other hand, the system temperature is already below the main pregelation processing temperature, reducing the risk of short-term softening, adhesion, localized debonding, or detachment of the organic coating layer. It also reduces the possibility of hexagonal boron nitride and talc sheets stacking, breaking, or functional pathway interruption under high-temperature, high-shear conditions. Therefore, this cooling is not ordinary cooling, but a process control that balances matrix acceptability and functional component protection.

[0011] The epoxidized wetting component is used in stages. The first part is used for wetting the initial layered acid-capturing material, and the remaining part is used for pre-wetting the subsequent organically coated phosphorus-nitrogen flame-retardant microcapsules and sheet-like abrasion-resistant barrier materials. Initial wetting facilitates the entry of the acid-capturing material into the CPVC base system before pre-gelling, while subsequent wetting helps reduce dry friction, localized adhesion, and interface defects between microcapsules, between sheet-like materials, and between both and the cooled pre-gelled matrix. By using the same type of wetting component at different stages to serve the construction of the acid buffer environment and the interface protection of sensitive functional components, interface control during processing can be made more continuous and stable.

[0012] Therefore, the obtained high-barrier, wear-resistant, and flame-retardant CPVC cable protection material not only maintains good processing stability, impact resistance, flame retardancy, wear resistance, and barrier properties, but also helps to maintain the functional integrity of the flame-retardant component and the sheet barrier component after dragging, cable threading, burying, and external friction, thereby improving the retention of flame retardant and barrier properties after material wear.

[0013] Preferably, the raw materials comprise the following components by weight: 100 parts chlorinated polyvinyl chloride resin; 2-4.5 parts heat stabilizer; 1-3.5 parts processing aid; 0.3-1.8 parts lubricant; 1.5-4 parts epoxidized wetting component; 4-11 parts barrier material with a layered acid-capturing structure; 4-8.5 parts organically coated phosphorus-nitrogen flame-retardant microcapsules; 5.5-12 parts sheet-like abrasion-resistant barrier material containing hexagonal boron nitride and talc; 4-10 parts chlorinated polyethylene; and 2.5-7 parts core-shell impact modifier. The above component proportions can balance the processing fluidity, thermal stability, impact resistance, flame retardancy, abrasion resistance, and barrier properties of CPVC materials. CPVC resin serves as the main continuous phase, while heat stabilizers and processing aids ensure stability during processing. Chlorinated polyethylene and core-shell impact modifiers improve the impact resistance of the pipes during use. Epoxidized wetting components, layered acid trapping and barrier materials, microencapsulated flame retardants, and sheet-like abrasion-resistant barrier materials work together to ensure processing stability and maintain functionality after wear. This ensures that the material does not rely solely on a single filler to improve a single property, but rather forms a structural combination among multiple components.

[0014] Preferably, the epoxidized wetting component includes one or more of epoxidized vegetable oil, epoxidized fatty acid ester, and epoxidized polybutadiene. The above-mentioned epoxidized wetting component has good organic phase compatibility and interfacial wetting ability, and its epoxy structure can also provide a certain stabilizing auxiliary effect in the CPVC processing environment. When used for segmented wetting, it can enable inorganic layered materials, microencapsulated flame retardants, and sheet-like abrasion-resistant barrier materials to achieve a smoother interfacial transition at different stages, reducing localized friction, agglomeration, and interfacial defects that occur when functional components directly contact the resin semi-gel system.

[0015] Preferably, the barrier material with a layered acid-capturing structure comprises layered double hydroxides and layered silicates, wherein the mass ratio of the layered double hydroxides to the layered silicates is 1:0.25 to 1:1.5. The layered double hydroxides possess acid adsorption and buffering capabilities, while the layered silicates provide sheet-like barrier and pathway extension functions. When combined, they can form a layered functional structure in the CPVC system that combines acid buffering and pathway barrier construction. This is beneficial for reducing local acid accumulation during the pre-gelling stage and for extending the diffusion path of oxygen, water vapor, or corrosive media after material molding, thereby improving the barrier stability of the material.

[0016] Preferably, the layered double hydroxide comprises one or more of magnesium aluminum hydrotalcite, zinc aluminum hydrotalcite, and magnesium zinc aluminum hydrotalcite; the layered silicate comprises one or more of montmorillonite, mica powder, vermiculite, and kaolinite. The aforementioned layered double hydroxides can provide relatively stable layered alkaline sites and acid trapping sites in a heated processing environment, while the layered silicate has a high aspect ratio and lamellar barrier characteristics. Using both in a CPVC system can create a more dispersed layered shielding structure within the material, which is beneficial for reducing the adverse effects of localized acidic substances during processing and for improving the barrier retention capability of the material during service.

[0017] Preferably, the barrier material with a layered acid-capturing structure comprises magnesium aluminum hydrotalcite and sodium montmorillonite, wherein the mass ratio of magnesium aluminum hydrotalcite to sodium montmorillonite is 1:0.35 to 1:0.9. Magnesium aluminum hydrotalcite has good acid-capturing and thermal stabilizing effects, while sodium montmorillonite has good lamellar barrier and dispersion modification properties. When the two are combined in this ratio, insufficient acid-capturing components can be avoided, leading to inadequate processing buffering. Conversely, an excessively high proportion of lamellar silicates can also be avoided, resulting in increased system viscosity, agglomeration, or decreased processing fluidity. This achieves a better balance between processing stability and barrier effect.

[0018] Preferably, the organically coated phosphorus-nitrogen flame-retardant microcapsules comprise a phosphorus-nitrogen flame-retardant core material and an organic coating layer covering the outer surface of the phosphorus-nitrogen flame-retardant core material; the phosphorus-nitrogen flame-retardant core material comprises one or more of ammonium polyphosphate, melamine polyphosphate, and piperazine pyrophosphate; the organic coating layer comprises one or more of siloxane resin, polyurea resin, polyurethane resin, and siloxane-polyurea composite layer. The phosphorus-nitrogen flame-retardant core material can promote charring, expansion, and thermal insulation when heated, while the organic coating layer can improve the interfacial state between the flame-retardant core material and the CPVC matrix, and reduce the risk of migration, moisture absorption, or interfacial detachment of the flame-retardant core material during processing and service. Adding these microcapsules after pre-gelation better protects the integrity of the organic coating layer, allowing it to maintain a relatively stable flame-retardant synergistic effect when the material is subjected to heat.

[0019] Preferably, the organically coated phosphorus-nitrogen flame-retardant microcapsules use ammonium polyphosphate and piperazine pyrophosphate as the phosphorus-nitrogen flame-retardant core materials, with the mass ratio of ammonium polyphosphate to piperazine pyrophosphate being 1:0.2 to 1:1.2. The organic coating layer is a siloxane-polyurea composite layer, and the organic coating layer accounts for 3% to 15% of the total weight of the organically coated phosphorus-nitrogen flame-retardant microcapsules. The combination of ammonium polyphosphate and piperazine pyrophosphate provides an acid source, gas source, and char-forming promoter when heated, resulting in a more continuous char layer formation. The siloxane-polyurea composite layer also possesses a certain degree of flexible interface and heat-resistant shielding, which helps improve the dispersion stability of the flame-retardant core material in the CPVC system. Controlling the coating layer ratio within the above range provides sufficient interface protection without weakening the effective content of the flame-retardant core material due to excessive coating thickness.

[0020] Preferably, in the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc, the mass ratio of hexagonal boron nitride to talc is 1:2 to 1:5. Hexagonal boron nitride has a sheet-like structure, good lubrication and wear resistance properties, and thermal stability, while talc also has a layered structure and a certain degree of rigidity reinforcement. When combined, they can form a relatively continuous sheet-like barrier and wear-resistant support structure within the CPVC matrix, making it less likely for the functional layers to be rapidly damaged when the material surface is subjected to friction. This ratio allows the lubrication and wear resistance of hexagonal boron nitride and the layered barrier and support functions of talc to complement each other, thereby improving barrier retention and surface functional stability after wear.

[0021] Preferably, the total amount of the barrier material with a layered acid-capturing structure, the organically coated phosphorus-nitrogen flame-retardant microcapsules, and the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc is 13.5 to 30 parts; the mass ratio of the barrier material with the layered acid-capturing structure to the organically coated phosphorus-nitrogen flame-retardant microcapsules is 1:0.45 to 1:1.7, and the mass ratio of the organically coated phosphorus-nitrogen flame-retardant microcapsules to the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc is 1:0.8 to 1:2.4. The total amount and mutual ratio of the three functional components create a relatively stable synergistic relationship between acid buffering, flame retardant charring, and sheet-like wear-resistant barrier. The layered acid-capturing material provides a basic stable environment during the processing and service stages, the microcapsule flame retardant provides flame retardant charring ability under thermal action, and the hexagonal boron nitride and talc provide the path for sheet-like wear-resistant barrier. By controlling the proportions of the three components, it is possible to avoid excessive amounts of a certain type of functional component, which could lead to decreased processing fluidity, increased interface defects, or unbalanced functional distribution, resulting in a material with better overall performance in terms of initial properties and functional retention after wear.

[0022] The present invention, by adopting the above technical solution, has the following beneficial effects: (1) In this invention, the first part of the epoxidized wetting component pre-wets the barrier material with a layered acid-capturing structure, so that it forms a better dispersion and interfacial contact state before the CPVC resin is pre-gelled. The layered material can adsorb, fix or neutralize and buffer the acidic substances that may be generated during the thermal shearing of CPVC, thereby reducing the impact of local acid accumulation on the stability of the continuous phase of the resin and the interface of subsequent functional components, and improving the stability of the material processing.

[0023] (2) In this invention, without the organically coated phosphorus-nitrogen flame-retardant microcapsules and sheet-like abrasion-resistant barrier materials participating in high-temperature pre-gelling treatment, the CPVC resin is first used to form a pre-gelled matrix, and then the above-mentioned functional components are introduced in the form of a post-added functional premix after cooling. This method allows the microcapsule flame-retardant components and sheet-like abrasion-resistant barrier components to enter the resin matrix under milder conditions, reducing the risk of softening and adhesion of the coating layer, local desorption, and failure of sheet-like material stacking.

[0024] (3) In this invention, the epoxidized wetting component is used in stages. The first stage is used to wet the layered acid capture and barrier material, and the second stage is used to wet the organically coated phosphorus and nitrogen flame-retardant microcapsules and the sheet-like wear-resistant barrier material. This allows the same type of wetting component to play a role in dispersing the acid capture material and protecting the interface of sensitive functional components at different processing stages. This staged wetting method helps to reduce the agglomeration of functional components, dry friction, and interface defects, so that the flame-retardant, wear-resistant, and barrier functions are maintained in a relatively stable distribution state in the CPVC matrix.

[0025] (4) This invention combines layered acid-capturing barrier materials, organically coated phosphorus and nitrogen flame-retardant microcapsules, and sheet-like wear-resistant barrier materials containing hexagonal boron nitride and talc, enabling the materials to simultaneously possess processing stability, flame retardant charring, sheet-like barrier properties, and wear-resistant support. The resulting CPVC cable protection material can improve flame retardant, wear-resistant, and barrier properties while maintaining good processing and mechanical properties, and is particularly beneficial in maintaining good flame retardant and barrier properties after dragging, cable threading, burial, and external friction. 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] Unless otherwise defined, all scientific and technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0028] 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.

[0029] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0030] The present invention will now be described in detail with reference to specific embodiments, which are intended to understand rather than limit the invention.

[0031] Unless otherwise specified, in the following examples, the CPVC resin is powdered chlorinated polyvinyl chloride resin, CAS number 68648-82-8, with a chlorine mass fraction of 67.3% and a Vicat softening temperature of 116.7℃; the calcium-zinc composite heat stabilizer is a powdered calcium-zinc heat stabilizer suitable for CPVC processing, mainly including calcium organic acid salts, zinc organic acid salts, and β-diketone auxiliary stabilizing components; the processing aid is a methyl methacrylate-acrylate copolymer processing aid; the polyethylene wax has CAS number 9002-88-4 and a dropping melting point of 108.9℃; the calcium stearate has CAS number 1592-23-0 and is an industrial-grade powder; the epoxidized soybean oil has CAS number 8013-07-8 and an epoxy value of 6.1%; magnesium aluminum molten metal... Talc is a magnesium-aluminum layered double hydroxide, CAS number 11097-59-9, with a D50 particle size of 1.86 μm; sodium montmorillonite is a layered sodium montmorillonite, CAS number 1318-93-0, with a D50 particle size of 3.42 μm; hexagonal boron nitride is a plate-like hexagonal boron nitride, CAS number 10043-11-5, with a D50 particle size of 4.18 μm; talc is a plate-like talc powder, CAS number 14807-96-6, with a D50 particle size of 6.74 μm; the chlorine mass fraction of chlorinated polyethylene is 35.2%; the core-shell impact modifier is a methyl methacrylate-butadiene-styrene core-shell impact modifier; the CAS number of heavy calcium carbonate is 471-34-1, with a D50 particle size of 6.47 μm.

[0032] The organic-coated phosphorus-nitrogen flame-retardant microcapsules have a D50 particle size of 8.63 μm. The core material is ammonium polyphosphate and piperazine pyrophosphate. The CAS number of ammonium polyphosphate is 68333-79-9, and the mass ratio of ammonium polyphosphate to piperazine pyrophosphate is 1:0.55. The coating layer is a siloxane-polyurea composite layer with a mass fraction of 9.3%. These organic-coated phosphorus-nitrogen flame-retardant microcapsules can be prepared using conventional interfacial polymerization coating methods in the art. Specifically, ammonium polyphosphate and piperazine pyrophosphate are dispersed in an aqueous phase containing a nonionic dispersant. An aminosilane modifier and an isocyanate-based polyurea film-forming component are added, and the mixture is stirred and reacted at 40℃–55℃ for 2–4 hours, allowing the siloxane-polyurea composite layer to coat the surface of the phosphorus-nitrogen flame-retardant core material. After solid-liquid separation, washing, and drying, the product is obtained. Alternatively, commercially available organic-coated phosphorus-nitrogen flame-retardant microcapsules that meet the above requirements for core material composition, coating layer composition, coating layer mass fraction, and particle size can be selected.

[0033] Example 1

[0034] This embodiment discloses a method for preparing a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material. The raw materials, by weight, include: 100 parts of CPVC resin, 3.2 parts of calcium-zinc composite heat stabilizer, 2.1 parts of processing aid, 0.7 parts of polyethylene wax, 0.5 parts of calcium stearate, 2.8 parts of epoxidized soybean oil, 5 parts of magnesium aluminum hydrotalcite, 2.5 parts of sodium montmorillonite, 6.2 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 2.2 parts of hexagonal boron nitride, 6.6 parts of talc, 7 parts of chlorinated polyethylene, and 4.5 parts of core-shell impact modifier.

[0035] S1. Add CPVC resin, calcium-zinc composite heat stabilizer, processing aid, polyethylene wax, calcium stearate, chlorinated polyethylene and core-shell type impact modifier to a high-speed mixer and mix for 4 minutes at 45℃ and 500r / min to obtain the basic premix.

[0036] S2. First, add 1.96 parts of epoxidized soybean oil, 5 parts of magnesium aluminum hydrotalcite and 2.5 parts of sodium montmorillonite to a low-speed mixer and mix for 3 minutes at 50°C and 420 r / min to obtain a wetted layered acid capture material. Then, add the wetted layered acid capture material to the basic premix and heat the high-speed mixer to 78°C and mix for 6 minutes at 760 r / min to obtain a pre-wetted acid capture material.

[0037] S3. Continue heating the pre-wetting acid capture material to 116℃ and pre-gelatinize it at 1100r / min for 9min to form a pre-gelatinized matrix of CPVC resin, thus obtaining the pre-gelatinized material.

[0038] S4. Turn on the cooling water in the jacket of the high-speed mixer and reduce the stirring speed to 250 r / min. Cool the pregelated material from 116℃ to 94℃ for 4 minutes to obtain the cooled pregelated material.

[0039] S5. Add 6.2 parts of organically coated phosphorus and nitrogen flame retardant microcapsules, 2.2 parts of hexagonal boron nitride, 6.6 parts of talc and 0.84 parts of epoxidized soybean oil to a low-speed mixer and mix for 5 minutes at 45℃ and 450r / min to pre-wet the organically coated phosphorus and nitrogen flame retardant microcapsules, hexagonal boron nitride and talc, to obtain the post-added functional premix.

[0040] S6. Add the post-added functional premix to the cooled pregelated material, control the mixing temperature to 94℃, and mix for 6 minutes at 520r / min to disperse the organic-coated phosphorus and nitrogen flame-retardant microcapsules, hexagonal boron nitride and talc in the cooled CPVC pregelated matrix to obtain the functionalized mixture.

[0041] S7. The functionalized mixture is added to a twin-screw extruder for extrusion granulation. The twin-screw extruder has a screw length-to-diameter ratio of 40:1, and the temperatures of each zone are 155℃, 165℃, 172℃, 178℃, 180℃, and 178℃ respectively. The die head temperature is 175℃, the screw speed is 160 r / min, and the vacuum degree of the vacuum exhaust section is -0.06 MPa. After water cooling, traction, and pelletizing, the extrudate is dried at 80℃ for 3 hours to obtain high-barrier, wear-resistant, and flame-retardant CPVC cable protection material.

[0042] Example 2

[0043] This embodiment discloses a method for preparing a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material. Compared with Embodiment 1, the difference is that the raw materials, by weight, include 100 parts of CPVC resin, 3.5 parts of calcium-zinc composite heat stabilizer, 2.2 parts of processing aid, 0.8 parts of polyethylene wax, 0.5 parts of calcium stearate, 3.2 parts of epoxidized soybean oil, 7 parts of magnesium aluminum hydrotalcite, 2.5 parts of sodium montmorillonite, 5.8 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 2 parts of hexagonal boron nitride, 7 parts of talc, 7.5 parts of chlorinated polyethylene, and 4.5 parts of core-shell impact modifier.

[0044] In step S2, 2.56 parts of epoxidized soybean oil, 7 parts of magnesium aluminum hydrotalcite, and 2.5 parts of sodium montmorillonite are mixed at 50℃ and 420 r / min for 3 min to obtain a wetted layered acid-capturing material. This material is then added to the basic premix and mixed at 80℃ and 780 r / min for 6 min to obtain a pre-wetted acid-capturing material. In step S3, the pregelation temperature is 118℃, the pregelation speed is 1120 r / min, and the pregelation time is 9 min. In step S4, the pregelated material is cooled from 118℃ to 98℃. In step S5, 5.8 parts of organically coated phosphorus-nitrogen flame-retardant microcapsules, 2 parts of hexagonal boron nitride, 7 parts of talc, and 0.64 parts of epoxidized soybean oil are added, and the mixing conditions are 45℃, 450 r / min, and 5 min. In step S6, the mixing temperature is controlled at 98℃, the mixing speed at 520 r / min, and the mixing time is 6 min. The other raw materials and operating procedures are the same as in Example 1.

[0045] Example 3

[0046] This embodiment discloses a method for preparing a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material. Compared with Embodiment 1, the difference is that the raw materials, by weight, include 100 parts of CPVC resin, 3.4 parts of calcium-zinc composite heat stabilizer, 2.3 parts of processing aid, 0.7 parts of polyethylene wax, 0.6 parts of calcium stearate, 3.4 parts of epoxidized soybean oil, 4.5 parts of magnesium aluminum hydrotalcite, 2.3 parts of sodium montmorillonite, 7.8 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 2.6 parts of hexagonal boron nitride, 7.8 parts of talc, 7 parts of chlorinated polyethylene, and 5 parts of core-shell impact modifier.

[0047] In step S2, 2.11 parts of epoxidized soybean oil, 4.5 parts of magnesium aluminum hydrotalcite, and 2.3 parts of sodium montmorillonite are mixed at 50℃ and 420 r / min for 3 min to obtain a wetted layered acid-capturing material. This material is then added to the basic premix and mixed at 78℃ and 760 r / min for 6 min to obtain a pre-wetted acid-capturing material. In step S3, the pregelation temperature is 118℃, the pregelation speed is 1100 r / min, and the pregelation time is 10 min. In step S4, the pregelated material is cooled from 118℃ to 92℃. In step S5, 7.8 parts of organically coated phosphorus-nitrogen flame-retardant microcapsules, 2.6 parts of hexagonal boron nitride, 7.8 parts of talc, and 1.29 parts of epoxidized soybean oil are added, and the mixing conditions are 45℃, 450 r / min, and 5 min. In step S6, the mixing temperature is controlled at 92°C, the mixing speed is 480 r / min, and the mixing time is 7 min. Other raw materials and operating procedures are the same as in Example 1.

[0048] Example 4

[0049] This embodiment discloses a method for preparing a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material. Compared with Embodiment 1, the difference is that the raw materials, by weight, include 100 parts of CPVC resin, 3 parts of calcium-zinc composite heat stabilizer, 2 parts of processing aid, 0.7 parts of polyethylene wax, 0.5 parts of calcium stearate, 2.6 parts of epoxidized soybean oil, 4.8 parts of magnesium aluminum hydrotalcite, 2.4 parts of sodium montmorillonite, 6 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 2.1 parts of hexagonal boron nitride, 6.3 parts of talc, 7 parts of chlorinated polyethylene, and 4.5 parts of core-shell impact modifier.

[0050] In step S2, 1.82 parts of epoxidized soybean oil, 4.8 parts of magnesium aluminum hydrotalcite, and 2.4 parts of sodium montmorillonite are mixed at 50°C and 420 r / min for 3 min to obtain a wetted layered acid-capturing material; this material is then added to the basic premix and mixed at 78°C and 760 r / min for 6 min. In step S3, the pregelation temperature is 114°C, the pregelation speed is 1080 r / min, and the pregelation time is 9 min. In step S4, the pregelated material is cooled from 114°C to 97°C, a temperature difference of 17°C. In step S5, 6 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 2.1 parts of hexagonal boron nitride, 6.3 parts of talc, and 0.78 parts of epoxidized soybean oil are added. In step S6, the mixing temperature is controlled at 97°C, the mixing speed is 540 r / min, and the mixing time is 6 min. Other raw materials and operating procedures are the same as in Example 1.

[0051] Comparative Example 1 This comparative example discloses a method for preparing CPVC cable protection material. Compared with Example 1, the difference lies in the omission of the post-addition of functional premix in steps S4 to S6. Specifically, in step S1, CPVC resin, calcium-zinc composite heat stabilizer, processing aid, polyethylene wax, calcium stearate, chlorinated polyethylene, and core-shell impact modifier are mixed. In step S2, 2.8 parts of epoxidized soybean oil, 5 parts of magnesium aluminum hydrotalcite, 2.5 parts of sodium montmorillonite, 6.2 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 2.2 parts of hexagonal boron nitride, and 6.6 parts of talc are added all at once, and the mixture is stirred at 78°C and 760 r / min for 6 min. Subsequently, in step S3, the temperature is raised to 116°C, and the mixture is pre-gelled at 1100 r / min for 9 min. After pre-gelling, the mixture is directly extruded and granulated according to step S7 of Example 1. Other raw materials and process conditions are the same as in Example 1.

[0052] Comparative Example 2 This comparative example discloses a method for preparing CPVC cable protection material. Compared with Example 1, the difference is that in step S4, the pregelatinized material is cooled from 116°C to 108°C, with a temperature difference of 8°C; in step S6, the added functional premix is ​​added and mixed for 6 minutes at 108°C and 520 r / min. Other raw materials, steps S1 to S3, S5, and S7 are the same as in Example 1.

[0053] Comparative Example 3 This comparative example discloses a method for preparing CPVC cable protection material. Compared with Example 1, the difference is that: all 2.8 parts of epoxidized soybean oil are added in step S2 for mixing with 5 parts of magnesium aluminum hydrotalcite and 2.5 parts of sodium montmorillonite; in step S5, epoxidized soybean oil is no longer added, and only 6.2 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 2.2 parts of hexagonal boron nitride, and 6.6 parts of talc are dry-mixed at 45°C and 450 r / min for 5 min as a post-added functional premix. Other raw materials and process conditions are the same as in Example 1.

[0054] Comparative Example 4 This comparative example discloses a method for preparing CPVC cable protection material. The difference from Example 1 is that the pre-wetting treatment of the layered acid-capturing material is omitted in step S2. Specifically, 1.96 parts of epoxidized soybean oil are directly added to the basic premix and mixed at 78°C and 760 r / min for 3 min; then 5 parts of magnesium aluminum hydrotalcite and 2.5 parts of sodium montmorillonite are added, and the mixture is further mixed at 78°C and 760 r / min for 3 min to obtain the mixture. Subsequent steps S3 to S7 are the same as in Example 1.

[0055] Comparative Example 5 This comparative example discloses a method for preparing CPVC cable protection material. Compared with Example 1, the difference is that 8.8 parts of heavy calcium carbonate are used instead of 2.2 parts of hexagonal boron nitride and 6.6 parts of talc. In step S5, 6.2 parts of organically coated phosphorus and nitrogen flame-retardant microcapsules, 8.8 parts of heavy calcium carbonate, and 0.84 parts of epoxidized soybean oil are added to a low-speed mixer and mixed for 5 minutes at 45°C and 450 r / min to obtain a post-functionalized premix. Other raw materials and process conditions are the same as in Example 1.

[0056] Performance testing

[0057] To verify the technical effectiveness of the present invention, performance tests were conducted on the CPVC cable protection materials obtained in Examples 1-4 and Comparative Examples 1-5. The following test data are obtained from tests conducted on samples from the same batch under the same conditions, and the average value of 5 parallel samples is taken for each group of data.

[0058] Sample preparation and conditioning: The granules obtained in Examples 1-4 and Comparative Examples 1-5 were dried at 80°C for 3 hours, and then standard specimens for tensile, flexural, impact, and flammability tests were prepared using an injection molding machine. Sheets with a thickness of 1 mm were prepared by hot-pressing at 175°C and 10 MPa for 5 minutes using a flat vulcanizing machine, followed by cold pressing to room temperature for water vapor transmission rate and oxygen transmission rate testing. After specimen preparation, the specimens were conditioned for 24 hours in an environment with a temperature of 23°C and a relative humidity of 50% according to GB / T 2918-2018 Standard Environment for Conditioning and Testing of Plastic Specimens before testing.

[0059] 1. Oxygen Index Detection The limiting oxygen index of the specimens was tested according to GB / T 2406.2-2009 Determination of flammability by oxygen index method for plastics – Part 2: Room temperature test. To evaluate the flame retardant retention of the material after abrasion, one side of the standard oxygen index specimen was first abraded, and then the oxygen index after abrasion was tested. The abrasion treatment was performed using a sliding friction and wear tester with a load of 20 N, a rotation speed of 200 r / min, and an abrasion time of 20 min. After abrasion, surface debris was removed with a lint-free cloth, and no further surface treatment was performed. The oxygen index retention rate was calculated as the ratio of the oxygen index after abrasion to the oxygen index before abrasion. The test results are shown in Table 1.

[0060] Table 1. Oxygen Index and its Retention After Wear Example 1 35.8 34.1 95.3 Example 2 35.5 34.2 96.3 Example 3 36.7 35.4 96.5 Example 4 34.9 33.1 94.8 Comparative Example 1 34.6 28.7 82.9 Comparative Example 2 35.1 30.4 86.6 Comparative Example 3 35.3 31.2 88.4 Comparative Example 4 35.2 32.4 92.1 Comparative Example 5 33.8 31.5 93.2 As shown in Table 1, the oxygen index of Examples 1-4 before wear was 34.9%-36.7%, and after wear, the oxygen index remained at 33.1%-35.4%, with an oxygen index retention rate of 94.8%-96.5%. This indicates that the obtained CPVC cable protection material can still maintain good flame retardant performance after surface wear. In Comparative Example 1, the flame retardant microcapsules and sheet-like wear-resistant barrier material underwent high-temperature pre-gelling treatment together, and the oxygen index retention rate after wear decreased to 82.9%. Comparative Example 2 had insufficient cooling, and Comparative Example 3 omitted the subsequent epoxidation wetting protection, resulting in a significantly lower oxygen index retention rate after wear compared to the Examples. The above results indicate that cooling after pre-gelling, subsequent wetting protection, and avoiding premature high-temperature strong shearing of the flame retardant microcapsules are beneficial to improving the flame retardant retention ability of the material after wear.

[0061] 2. Vertical burning detection Vertical burning tests were conducted according to GB / T 2408-2021 "Determination of Burning Performance of Plastics - Horizontal and Vertical Methods", with a sample thickness of 3.2 mm. Before testing, one set of samples was directly subjected to the vertical burning test; the other set of samples underwent surface abrasion treatment according to the abrasion conditions in the oxygen index test before undergoing the vertical burning test. The vertical burning rating was determined according to the standard specifications. The test results are shown in Table 2.

[0062] Table 2. Vertical Combustion Performance Test Results Example 1 V-0 V-0 5.8 Example 2 V-0 V-0 5.3 Example 3 V-0 V-0 4.9 Example 4 V-0 V-0 6.6 Comparative Example 1 V-0 V-2 23.7 Comparative Example 2 V-0 V-1 14.8 Comparative Example 3 V-0 V-1 12.9 Comparative Example 4 V-0 V-1 9.7 Comparative Example 5 V-1 V-1 11.6 As shown in Table 2, Examples 1-4 all achieved a V-0 rating before and after abrasion, with a maximum afterflame time of 4.9s-6.6s after abrasion, indicating that the material still possesses relatively stable self-extinguishing ability after surface abrasion. Comparative Example 1 decreased to a V-2 rating after abrasion, while Comparative Examples 2 and 3 decreased to a V-1 rating. This indicates that the combined participation of functional components in high-temperature pre-gelation, insufficient cooling, and lack of subsequent wetting protection all affect the flame retardant stability after abrasion. Comparative Example 5 maintained a V-1 rating both before and after abrasion, demonstrating that ordinary heavy calcium carbonate cannot replace the role of hexagonal boron nitride and talc flakes in flame retardant retention and surface protection.

[0063] 3. Wear resistance test The sliding friction and wear test was conducted according to GB / T 3960-2016, "Test Method for Sliding Friction and Wear of Plastics". The sample size was 30mm × 7mm × 6mm, the friction ring was a No. 45 steel ring, the test load was 20N, the rotation speed was 200r / min, and the test time was 30min. The sample mass was weighed before and after the test, the wear mass loss was calculated, and the average friction coefficient was recorded. The test results are shown in Table 3.

[0064] Table 3 Abrasion resistance test results Example 1 0.318 18.6 Example 2 0.326 19.4 Example 3 0.305 16.8 Example 4 0.334 21.7 Comparative Example 1 0.389 31.6 Comparative Example 2 0.371 28.4 Comparative Example 3 0.358 25.9 Comparative Example 4 0.346 23.5 Comparative Example 5 0.427 39.2 As shown in Table 3, the average friction coefficients of Examples 1-4 ranged from 0.305 to 0.334, and the wear mass loss ranged from 16.8 mg to 21.7 mg, indicating that the obtained materials have good wear resistance. Among them, Example 3 had a lower friction coefficient and wear mass loss due to the higher wetting ratio in the later stage and the higher amount of sheet-like wear-resistant barrier material. In Comparative Example 5, after replacing the combination of hexagonal boron nitride and talc with heavy calcium carbonate, the average friction coefficient increased to 0.427, and the wear mass loss increased to 39.2 mg, indicating that non-sheet-like ordinary inorganic fillers are difficult to form effective slip protection and wear-resistant support. The wear mass losses of Comparative Examples 1 and 2 were also higher than those of the Examples, indicating that the sheet-like material is more conducive to maintaining its wear resistance when dispersed later under milder conditions.

[0065] 4. Water vapor transmission rate test Water vapor transmission rate was tested according to GB / T 1037-2021 "Determination of Water Vapor Transmission Performance of Plastic Films and Sheets - Cup-type Weight Gain and Weight Loss Method". Since the material of this invention is CPVC cable protection material, the granules obtained from the examples and comparative examples were hot-pressed into sheets with a thickness of 1 mm to evaluate the water vapor barrier performance of the material itself. The test temperature was 38℃, and the relative humidity difference was 90%. For the water vapor transmission rate test after abrasion, one side of the sheet was first abraded under the following conditions: load 20N, rotation speed 200 r / min, and abrasion time 20 min. Then, the abraded surface was turned towards the high humidity side for testing. The barrier retention rate was calculated as the ratio of the water vapor transmission rate before abrasion to the water vapor transmission rate after abrasion. The test results are shown in Table 4.

[0066] Table 4. Test results of water vapor barrier performance Example 1 4.82 5.39 89.4 Example 2 4.64 5.13 90.4 Example 3 4.57 4.98 91.8 Example 4 5.18 5.96 86.9 Comparative Example 1 5.62 8.74 64.3 Comparative Example 2 5.27 7.42 71 Comparative Example 3 5.09 6.82 74.6 Comparative Example 4 5.36 6.61 81.1 Comparative Example 5 7.28 10.96 66.4 As shown in Table 4, the water vapor transmission rates before wear in Examples 1-4 were 4.57 g·m⁻²·d⁻¹ to 5.18 g·m⁻²·d⁻¹, and the water vapor barrier retention rates after wear were 86.9% to 91.8%, indicating that the materials can still maintain good water vapor barrier performance after surface wear. In Comparative Example 5, after replacing the combination of hexagonal boron nitride and talc with heavy calcium carbonate, the water vapor transmission rates before and after wear increased significantly, and the water vapor barrier retention rate was only 66.4%, indicating that ordinary fillers are difficult to form stable sheet-like barrier paths. The barrier retention rates after wear in Comparative Examples 1, 2, and 3 were all lower than those in the Examples, indicating that the high-temperature pre-gelling treatment, insufficient cooling, and lack of wetting protection in the later stage are all detrimental to the retention of the sheet-like barrier structure after wear.

[0067] 5. Oxygen permeability test Oxygen permeability testing was conducted according to GB / T 1038.1-2022 Test Methods for Gas Permeability of Plastic Products (Films and Sheets) Part 1: Differential Pressure Method. Since the material of this invention is CPVC cable protection material, the granules obtained in the examples and comparative examples were hot-pressed into sheets with a thickness of 1 mm to evaluate the oxygen barrier performance of the material itself. The test temperature was 23℃, and the test gas was oxygen. For the oxygen permeability test after wear, the sample was first subjected to single-sided wear treatment with a load of 20 N, a rotation speed of 200 r / min, and a wear time of 20 min, and then the worn surface was faced towards the oxygen side for testing. The oxygen barrier retention rate was calculated as the ratio of the oxygen permeability before wear to the oxygen permeability after wear. The test results are shown in Table 5.

[0068] Table 5 Oxygen Barrier Performance Test Results Example 1 42.6 48.9 87.1 Example 2 40.8 46.2 88.3 Example 3 39.7 44.2 89.8 Example 4 45.3 53.6 84.5 Comparative Example 1 51.8 79.4 65.2 Comparative Example 2 48.7 68.5 71.1 Comparative Example 3 47.5 63.9 74.3 Comparative Example 4 49.6 60.7 81.7 Comparative Example 5 66.9 98.8 67.7 As shown in Table 5, the oxygen permeability before wear in Examples 1-4 was 39.7 cm. 3·m -2 ·d -1 0.1MPa -1 ~45.3cm 3 ·m -2 ·d -1 0.1MPa -1 The oxygen barrier retention rate after wear was 84.5%–89.8%, indicating that the obtained material has good oxygen barrier performance and retention capacity after wear. In Example 3, due to the higher wetting ratio and functional component ratio in the later stage, the oxygen barrier retention rate after wear reached 89.8%. The oxygen permeability before and after wear of Comparative Example 5 was significantly higher than that of the Example, indicating that heavy calcium carbonate is difficult to replace hexagonal boron nitride and talc in constructing sheet-like barrier pathways. The significant increase in oxygen permeability after wear in Comparative Examples 1 and 2 indicates that premature high-temperature pre-gelation of the functional components or excessively high post-treatment temperatures weaken the stable retention of the sheet-like barrier pathways.

[0069] 6. Mechanical property testing Tensile properties were tested according to GB / T 1040.2-2022 "Determination of tensile properties of plastics - Part 2: Test conditions for molded and extruded plastics", with a tensile speed of 50 mm / min. Flexural properties were tested according to GB / T 9341-2008 "Determination of flexural properties of plastics", with a test speed of 2 mm / min. Notched impact strength of simply supported beams was tested according to GB / T 1043.1-2008 "Determination of impact properties of simply supported beams of plastics - Part 1: Non-instrumental impact testing". Five parallel specimens were taken for each group, and the average value was used. The test results are shown in Table 6.

[0070] Table 6 Mechanical Performance Test Results Example 1 51.8 78.6 8.73 Example 2 50.9 79.4 8.41 Example 3 50.2 77.1 8.66 Example 4 52.4 80.2 8.28 Comparative Example 1 47.3 72.8 7.16 Comparative Example 2 48.5 74.1 7.54 Comparative Example 3 49.1 75.7 7.81 Comparative Example 4 49.6 76.2 8.03 Comparative Example 5 53.2 82.7 7.39 As shown in Table 6, the tensile strength of Examples 1-4 is 50.2 MPa to 52.4 MPa, the flexural strength is 77.1 MPa to 80.2 MPa, and the notched impact strength is 8.28 kJ·m. -2 ~8.73kJ·m -2 This demonstrates that the present invention can maintain good mechanical properties while introducing flame-retardant, abrasion-resistant, and barrier functional components. The tensile strength, flexural strength, and notched impact strength of Comparative Examples 1, 2, and 3 are generally lower than those of the Example, indicating that the timing of the addition of functional components and the interfacial wetting state affect the continuity and mechanical stability of the CPVC matrix. Although Comparative Example 5 exhibits higher tensile and flexural strength due to the rigid filling effect of heavy calcium carbonate, its notched impact strength is lower, and considering the aforementioned abrasion resistance and barrier results, its overall performance is inferior to that of the Example.

[0071] 7. Thermal stability test The static thermal stability time of the material was tested according to GB / T 2917.1-2002, "Determination of the Release of Hydrogen Chloride and Any Other Acidic Products at High Temperature from Blends and Products Mainly Based on Polyvinyl Chloride Homopolymers and Copolymers—Congo Red Method". The granules obtained in the examples and comparative examples were pulverized and passed through a 40-mesh sieve. 2g of sample was placed in a test tube and heated in an oil bath at 200℃. Congo red test paper was placed above the test tube, and the time required for the test paper to change from red to blue was recorded. Each group was tested three times, and the average value was taken. This method can reflect the trend of CPVC material releasing hydrogen chloride or other acidic products during heating, thereby evaluating the material's thermal stability and buffering effect against acidic substances. The test results are shown in Table 7.

[0072] Table 7. Results of Static Thermal Stability Time Test Example 1 42.6 Example 2 45.1 Example 3 40.8 Example 4 39.7 Comparative Example 1 34.2 Comparative Example 2 36.8 Comparative Example 3 38.5 Comparative Example 4 32.9 Comparative Example 5 39.4 As shown in Table 7, the static thermal stability times of Examples 1-4 ranged from 39.7 min to 45.1 min, significantly higher than those of Comparative Examples 1-4. This indicates that pre-wetting of the acid-capturing material and the segmented wetting process are beneficial for improving the stability of CPVC materials during heating. Specifically, Example 2, due to its higher proportion of pre-epoxidized wetting components and higher amount of layered acid-capturing material, achieved a static thermal stability time of 45.1 min. Comparative Example 4, without pre-wetting treatment with layered acid-capturing material, had a static thermal stability time reduced to 32.9 min. This suggests that the layered acid-capturing material, after forming a wetted and dispersed state before pre-gelling, is more conducive to the adsorption, fixation, or neutralization buffering of hydrogen chloride or other acidic products generated during CPVC heating. In Comparative Example 1, the functional components underwent high-temperature pre-gelling treatment, resulting in a lower static thermal stability time, indicating that this processing method is not conducive to maintaining the thermal stability of the system.

[0073] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-barrier, wear-resistant, and flame-retardant CPVC cable protection material, characterized in that, Includes the following steps: S1. Chlorinated polyvinyl chloride resin is premixed with heat stabilizer, processing aid, lubricant, chlorinated polyethylene and core-shell impact modifier to obtain basic premix; S2. Add a first part of epoxidized wetting component and a barrier material with a layered acid trapping structure to the basic premix, and mix them at a temperature lower than the subsequent pregelation temperature, so that the barrier material with a layered acid trapping structure is wetted by the first part of epoxidized wetting component before the chlorinated polyvinyl chloride resin is pregelated, to obtain a pre-wetting acid trapping material. S3. The pre-wetting acid capture material is heated to the pre-gelling temperature and pre-gelled to form a pre-gelled matrix of chlorinated polyvinyl chloride resin, thus obtaining a pre-gelled material. S4. Cool the pregelated material to a post-addition temperature that is 16-28°C lower than the pregelation temperature to obtain a cooled pregelated material. S5. The organic-coated phosphorus-nitrogen flame-retardant microcapsules, the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc, and the remaining epoxidized wetting component are premixed to pre-wet the organic-coated phosphorus-nitrogen flame-retardant microcapsules and the sheet-like wear-resistant barrier material, thereby obtaining a post-added functional premix. S6. Add the post-added functional premix to the cooled pregelated material and mix it at a temperature and speed lower than that in step S3, so that the organic-coated phosphorus and nitrogen flame-retardant microcapsules and the sheet-like wear-resistant barrier material are dispersed in the cooled chlorinated polyvinyl chloride pregelated matrix to obtain a functionalized mixture. S7. Extrude and granulate the functionalized mixture to obtain the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material; Wherein, the first portion of the epoxidized wetting component accounts for 60% to 85% of the total weight of the epoxidized wetting component, and the remaining portion of the epoxidized wetting component accounts for 15% to 40% of the total weight of the epoxidized wetting component; Both the organically coated phosphorus and nitrogen flame-retardant microcapsules and the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc are added as functional premixes after the pregelation treatment in step S3, and do not participate in the pregelation treatment in step S3.

2. The preparation method of the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 1, characterized in that, The raw materials comprise the following components by weight: 100 parts of chlorinated polyvinyl chloride resin; 2-4.5 parts of heat stabilizer; Processing aids: 1-3.5 parts; Lubricant 0.3–1.8 parts; Epoxidized wetting component: 1.5–4 parts; 4 to 11 parts of a barrier material with a layered acid trapping structure; Organically coated phosphorus and nitrogen flame-retardant microcapsules, 4–8.5 parts; 5.5–12 parts of a sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc; 4-10 parts of chlorinated polyethylene; 2.5 to 7 parts of core-shell impact modifier.

3. The method for preparing the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 1 or 2, characterized in that, The epoxidized wetting component includes one or more of epoxidized vegetable oil, epoxidized fatty acid ester, and epoxidized polybutadiene.

4. The method for preparing the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 1 or 2, characterized in that, The barrier material with a layered acid trapping structure includes a layered double hydroxide and a layered silicate, wherein the mass ratio of the layered double hydroxide to the layered silicate is 1:0.25 to 1:1.

5.

5. The preparation method of the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 4, characterized in that, The layered double hydroxide includes one or more of magnesium aluminum hydrotalcite, zinc aluminum hydrotalcite, and magnesium zinc aluminum hydrotalcite. The layered silicate includes one or more of montmorillonite, mica powder, vermiculite, and kaolin.

6. The method for preparing the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 5, characterized in that, The barrier material with a layered acid-capturing structure includes magnesium aluminum hydrotalcite and sodium montmorillonite, wherein the mass ratio of magnesium aluminum hydrotalcite to sodium montmorillonite is 1:0.35 to 1:0.

9.

7. The method for preparing the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 1 or 2, characterized in that, The organically coated phosphorus-nitrogen flame-retardant microcapsule includes a phosphorus-nitrogen flame-retardant core material and an organic coating layer covering the outer surface of the phosphorus-nitrogen flame-retardant core material; The phosphorus-nitrogen flame-retardant core material includes one or more of ammonium polyphosphate, melamine polyphosphate, and piperazine pyrophosphate. The organic coating layer includes one or more of the following: siloxane resin, polyurea resin, polyurethane resin, and siloxane-polyurea composite layer.

8. The method for preparing the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 7, characterized in that, The organically coated phosphorus-nitrogen flame-retardant microcapsules use ammonium polyphosphate and piperazine pyrophosphate as phosphorus-nitrogen flame-retardant core materials, with the mass ratio of ammonium polyphosphate to piperazine pyrophosphate being 1:0.2 to 1:1.

2. The organic coating layer is a siloxane-polyurea composite layer, and the organic coating layer accounts for 3% to 15% of the total weight of the organically coated phosphorus and nitrogen flame retardant microcapsules.

9. The method for preparing the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 1 or 2, characterized in that, In the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc, the mass ratio of hexagonal boron nitride to talc is 1:2 to 1:

5.

10. The method for preparing the high-barrier, wear-resistant, and flame-retardant CPVC cable protection material according to claim 2, characterized in that, The total amount of the barrier material with the layered acid-capturing structure, the organic-coated phosphorus and nitrogen flame-retardant microcapsules, and the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc is 13.5 to 30 parts. The mass ratio of the barrier material with the layered acid-capturing structure to the organically coated phosphorus-nitrogen flame-retardant microcapsules is 1:0.45 to 1:1.7, and the mass ratio of the organically coated phosphorus-nitrogen flame-retardant microcapsules to the sheet-like wear-resistant barrier material containing hexagonal boron nitride and talc is 1:0.8 to 1:2.4.