High-mechanical modified CPVC cable protection pipe

Abstract

The present application relates to cable protection pipe technical field, specifically to a kind of high mechanics modified CPVC cable protection pipe.In the present application, additive is made into organic-inorganic composite microparticle by needle-like wollastonite, nano bohmite and CPE-g-GMA by blending extrusion in advance, then added into CPVC matrix, the CPE-g-GMA elastomer phase in the composite microparticle can form stress concentration point when material is impacted by external force, impact energy is absorbed and dissipated by elastic deformation, the toughness of pipe is improved, the fibrous structure of needle-like wollastonite can form microskeleton in matrix, bear load and improve deformation resistance, the nano filling effect of nano bohmite can enhance the compactness of matrix, the three synergies make pipe keep good rigidity while significantly improve impact resistance, solve the problem that elastomer toughening and rigid filler reinforcing simple blending in prior art cannot realize complementary advantages, realize the purpose of high rigidity and high toughness.

Description

Technical Field

[0001] This invention relates to the field of cable protection pipe technology, specifically to a high-mechanical-modified CPVC cable protection pipe. Background Technology

[0002] CPVC cable protection pipes are pipes made from chlorinated polyvinyl chloride resin. They possess excellent heat resistance, chemical corrosion resistance, insulation, and flame-retardant self-extinguishing properties, and are widely used for the laying and protection of power cables and communication cables. With the advancement of urban power grid renovation and infrastructure construction, cable protection pipes often need to be laid in complex geological environments or subjected to large external loads, which places higher demands on the mechanical properties of the pipes. Improving the mechanical properties of CPVC pipes, especially impact resistance and rigidity, through formula modification and processing optimization is an important research direction in the field of cable protection pipes.

[0003] Existing CPVC cable protection pipes are often modified by adding elastomers or rigid fillers to improve their mechanical properties. However, while elastomers increase toughness, they often reduce the pipe's rigidity and heat resistance, while rigid fillers, while reinforcing, can easily lead to increased brittleness and poor processing fluidity. Simple blending of the two methods fails to achieve complementary advantages. The main challenge facing existing technologies is how to effectively improve the pipe's toughness while ensuring high rigidity and heat resistance, achieving a balance between high strength and high impact resistance. Therefore, this invention provides a highly mechanically modified CPVC cable protection pipe and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-mechanical-modified CPVC cable protection pipe, which solves the problem that the simple blending of elastomer toughening and rigid filler reinforcement in the prior art is difficult to achieve complementary advantages, and achieves the goal of simultaneously achieving high rigidity and high toughness.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-mechanical-modified CPVC cable protection pipe, comprising the following raw materials in parts by weight: 100 parts CPVC resin, 1-1.6 parts additives, 3-4 parts additives, 1.5-2.2 parts stabilizer, 0.15-0.35 parts aluminum magnesium hydrotalcite, 0.35-0.55 parts lubricant, 0.1-0.2 parts calcium stearate, 0.2-0.3 parts oxidized polyethylene wax, 0.15-0.35 parts antioxidant, 0.2-0.5 parts rutile titanium dioxide, and 0.08-0.1 parts pigment; The additive is prepared by the following method: S1: Material pretreatment. The materials selected are acicular wollastonite, nano boehmite, and CPE-g-GMA. The raw materials are pretreated and ready for use. S2: Blending treatment, the pretreated raw materials are blended to obtain the additive.

[0006] Preferably, the material pretreatment method is as follows: acicular wollastonite is dried at 105-110℃ for 3-3.5h, nano-boehmite is dried at 110-115℃ for 3-3.5h, and CPE-g-GMA is dried at 55-65℃ for 1-2h to complete the pretreatment of each raw material, and dried acicular wollastonite, nano-boehmite, and CPE-g-GMA are obtained.

[0007] Preferably, the blending process is as follows: Weigh dried wollastonite and nano-boehmite, and mix them in a low-speed mixer at 60-150 rpm for 10-20 minutes to obtain a premix. The dried CPE-g-GMA is fed into a twin-screw extruder through the main feed port, and then the premix is ​​fed in through the side feed port. After extrusion, it is hot-cut into particles of 0.5-1.5 mm to obtain the additive.

[0008] Preferably, the mass ratio of dried wollastonite, nanoboehmite and CPE-g-GMA is 4-4.5:1:1.2-1.3.

[0009] Preferably, in the blending process, the temperature of the feeding section is set to 110-115℃, the temperature of the conveying section is set to 120-125℃, the temperature of the first mixing section is set to 140-145℃, the temperature of the second mixing section is set to 150-155℃, the temperature of the homogenization section is set to 155-160℃, and the temperature of the die head is set to 150-155℃.

[0010] Preferably, the component content of the additive is: 0.2-0.6% methacrylic acid, 1.5-4% n-butyl acrylate, 4-8% ethyl acrylate, with the balance supplemented by methyl methacrylate to 100%.

[0011] Preferably, the CPE in the CPE-g-GMA has a chlorine content of 32-38% and an effective grafting rate of GMA of 0.8-1.5%.

[0012] Preferably, the chlorine content of the CPVC resin is 67-68.5%, and the original degree of polymerization of PVC is 700-900.

[0013] Preferably, the stabilizer is methyltin thiolate, the lubricant is pentaerythritol stearate, and the antioxidant is prepared by mixing antioxidant 168 and antioxidant 1010 in a mass ratio of 1:0.5.

[0014] Preferably, the preparation method of high mechanical strength modified CPVC cable protection pipe includes the following steps: weighing CPVC resin, additives, aluminum magnesium hydrotalcite and antioxidant, and stirring at 40-60 rpm for 4-8 minutes, then stirring at 200-300 rpm for 8-12 minutes, controlling the material temperature at 40-50℃, adding stabilizer, and continuing to mix at 200-300 rpm for 8-12 minutes, adding additives, rutile titanium dioxide and pigment at 60-70℃, and mixing at 250-350 rpm for 12-18 minutes, adding lubricant at 75-85℃, and mixing at 250-350 rpm for 12-18 minutes, and adding calcium stearate and oxidized polyethylene wax at 95-100℃. The material is hot-mixed at 108-112℃ and 120-180rpm for 6-10 minutes. After discharge, it is transferred to a mixer and stirred at room temperature at 120-180rpm for 10-20 minutes. After stirring, it is sealed and matured for 6-12 hours. The resulting product is transferred to a twin-screw extruder with the screw speed set at 15-25rpm, the feeding section temperature at 160-168℃, the compression section temperature at 168-176℃, the plasticizing section temperature at 176-184℃, the metering section temperature at 182-190℃, the connecting body temperature at 186-192℃, and the die temperature at 188-194℃. Then, a two-stage cooling and sizing process is used. The first sizing water temperature is 28-32℃, and the second stage is 20-25℃, to produce a high-mechanical-strength modified CPVC cable protection pipe.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, the additive is pre-formed into organic-inorganic composite microparticles by blending and extruding acicular wollastonite, nano-boehmite, and CPE-g-GMA, and then added to the CPVC matrix. The CPE-g-GMA elastomer phase in the composite microparticles can form stress concentration points when the material is subjected to external impact. It absorbs and dissipates impact energy through elastic deformation, thereby improving the toughness of the pipe. The fibrous structure of acicular wollastonite can form a micro-skeleton in the matrix, bearing the load and improving the resistance to deformation. The nano-filling effect of nano-boehmite can enhance the density of the matrix. The three work synergistically to significantly improve the impact resistance of the pipe while maintaining good rigidity. This solves the problem that it is difficult to achieve complementary advantages in the simple blending of elastomer toughening and rigid filler reinforcement in the prior art, and achieves the goal of simultaneously achieving high rigidity and high toughness.

[0016] 2. In this invention, the additive is a methyl methacrylate-acrylate copolymer, which has good compatibility with CPE-g-GMA. Its introduction helps to promote the uniform dispersion of the additive in the CPVC matrix, optimize the interface state between the organic and inorganic phases, reduce energy loss in the stress transmission process, and make the toughening and strengthening effects of each organic and inorganic component in the additive more fully realized.

[0017] 3. In this invention, the pipe preparation adopts a segmented temperature-controlled feeding process. In the low-temperature stage, the CPVC resin is fully mixed with additives and stabilizers to avoid local overheating that causes premature resin decomposition. In the high-temperature stage, additives, lubricants and processing aids are gradually added so that each component can be dispersed and plasticized at different temperature windows. Combined with a two-stage cooling and sizing process, the pipe is cooled evenly inside and out, has high dimensional accuracy, strong process controllability, and is suitable for continuous industrial production. Attached Figure Description

[0018] Figure 1 The present invention provides a flowchart of a high mechanical strength modified CPVC cable protection pipe. Detailed Implementation

[0019] The following will combine the embodiments of the present invention with... Figure 1 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

[0020] It should be noted that the raw materials used in the following embodiments are all commercially available.

[0021] Example 1:

[0022] Raw materials (parts by weight): 100 parts CPVC resin, 1.3 parts additives, 3.5 parts additives, 1.8 parts stabilizer, 0.25 parts aluminum magnesium hydrotalcite, 0.45 parts lubricant, 0.15 parts calcium stearate, 0.25 parts oxidized polyethylene wax, 0.25 parts antioxidant, 0.35 parts rutile titanium dioxide, and 0.09 parts pigment; CPVC resin: chlorine content is 67.5%, and the original degree of polymerization of PVC is 800; Additives: 0.4% methacrylic acid, 2.5% n-butyl acrylate, 6% ethyl acrylate, with the balance supplemented by methyl methacrylate to bring the total to 100%; CPE-g-GMA: CPE has a chlorine content of 35%, and the effective grafting rate of GMA is 1.2%; Stabilizer: Methyltin thiolate salt is selected; Lubricant: Pentaerythritol stearate is selected; Antioxidant: Prepared by mixing antioxidant 168 and antioxidant 1010 at a mass ratio of 1:0.5.

[0023] Preparation method: Preparation of additives: S1: Material pretreatment. The materials selected are acicular wollastonite, nano boehmite, and CPE-g-GMA. The raw materials are pretreated and ready for use. S2: Blending treatment, the pretreated raw materials are blended to obtain the additive.

[0024] The material pretreatment method is as follows: acicular wollastonite is dried at 108℃ for 3.2h, nano-boehmite is dried at 112℃ for 3.2h, and CPE-g-GMA is dried at 60℃ for 1.5h. The pretreatment of each raw material is completed to obtain dried acicular wollastonite, nano-boehmite, and CPE-g-GMA.

[0025] The blending process is as follows: Weigh the dried wollastonite and nano-boehmite, and mix them in a low-speed mixer at 100 rpm for 15 minutes to obtain a premix. The dried CPE-g-GMA is then fed into a twin-screw extruder through the main feed port, and the premix is ​​then fed in through the side feed port. After extrusion, it is thermally cut into 1 mm particles to obtain the additive.

[0026] The mass ratio of dried wollastonite, nano-boehmite, and CPE-g-GMA is 4.25:1:1.25. During the blending process, the temperature of the feeding section is set to 112℃, the temperature of the conveying section is set to 123℃, the temperature of the first mixing section is set to 143℃, the temperature of the second mixing section is set to 152℃, the temperature of the homogenization section is set to 158℃, and the temperature of the die head is set to 152℃.

[0027] Preparation of high-mechanical-strength modified CPVC cable protection pipe: Weigh CPVC resin, additives, aluminum-magnesium hydrotalcite, and antioxidant, and stir at 50 rpm for 6 minutes, then at 250 rpm for 10 minutes, controlling the material temperature at 45℃. Add stabilizer, and continue mixing at 250 rpm for 10 minutes. When the material temperature reaches 65℃, add additives, rutile titanium dioxide, and pigments, and mix at 300 rpm for 15 minutes. When the material temperature reaches 80℃, add lubricant, and mix at 300 rpm for 15 minutes. When the material temperature reaches 98℃, add calcium stearate and oxidized polyethylene wax. The material was hot-mixed at 110℃ and 150 rpm for 8 minutes. After discharge, it was transferred to a mixer and stirred at room temperature at 150 rpm for 15 minutes. After stirring, it was sealed and matured for 8 hours. The resulting product was transferred to a twin-screw extruder with the screw speed set at 20 rpm, the feeding section temperature at 164℃, the compression section temperature at 172℃, the plasticizing section temperature at 180℃, the metering section temperature at 186℃, the connecting body temperature at 189℃, and the die temperature at 191℃. Then, a two-stage cooling and sizing process was used, with the first sizing water temperature at 30℃ and the second at 22℃, to produce a high-mechanical-strength modified CPVC cable protection pipe.

[0028] Example 2:

[0029] Raw materials (parts by weight): 100 parts CPVC resin, 1 part additives, 3 parts additives, 1.5 parts stabilizer, 0.15 parts aluminum magnesium hydrotalcite, 0.35 parts lubricant, 0.1 parts calcium stearate, 0.2 parts oxidized polyethylene wax, 0.15 parts antioxidant, 0.2 parts rutile titanium dioxide and 0.08 parts pigment; CPVC resin: chlorine content is 67%, and the original degree of polymerization of PVC is 700; Additives: 0.2% methacrylic acid, 1.5% n-butyl acrylate, 4% ethyl acrylate, with the remainder supplemented to 100% by methyl methacrylate; CPE-g-GMA: CPE has a chlorine content of 32%, and the effective grafting rate of GMA is 0.8%; Stabilizer: Methyltin thiolate salt is selected; Lubricant: Pentaerythritol stearate is selected; Antioxidant: Prepared by mixing antioxidant 168 and antioxidant 1010 at a mass ratio of 1:0.5.

[0030] Preparation method: Preparation of additives: S1: Material pretreatment. The materials selected are acicular wollastonite, nano boehmite, and CPE-g-GMA. The raw materials are pretreated and ready for use. S2: Blending treatment, the pretreated raw materials are blended to obtain the additive.

[0031] The material pretreatment method is as follows: acicular wollastonite is dried at 105℃ for 3 hours, nano-boehmite is dried at 110℃ for 3 hours, and CPE-g-GMA is dried at 55℃ for 1 hour to complete the pretreatment of each raw material and obtain dried acicular wollastonite, nano-boehmite, and CPE-g-GMA.

[0032] The blending process is as follows: Weigh the dried wollastonite and nano-boehmite, and mix them in a low-speed mixer at 60 rpm for 10 minutes to obtain a premix. The dried CPE-g-GMA is then fed into a twin-screw extruder through the main feed port, and the premix is ​​then fed in through the side feed port. After extrusion, it is hot-cut into 0.5 mm particles to obtain the additive.

[0033] The mass ratio of dried wollastonite, nano-boehmite, and CPE-g-GMA is 4:1:1.2. During the blending process, the temperature of the feeding section is set to 110℃, the temperature of the conveying section is set to 120℃, the temperature of the first mixing section is set to 140℃, the temperature of the second mixing section is set to 150℃, the temperature of the homogenization section is set to 155℃, and the temperature of the die head is set to 150℃.

[0034] Preparation of high-mechanical-strength modified CPVC cable protection pipe: Weigh CPVC resin, additives, aluminum-magnesium hydrotalcite, and antioxidant, and stir at 40 rpm for 4 minutes, then at 200 rpm for 8 minutes, controlling the material temperature at 40℃. Add stabilizer, and continue mixing at 200 rpm for 8 minutes. When the material temperature reaches 60℃, add additives, rutile titanium dioxide, and pigments, and mix at 250 rpm for 12 minutes. When the material temperature reaches 75℃, add lubricant, and mix at 250 rpm for 12 minutes. When the material temperature reaches 95℃, add calcium stearate and oxidized polyethylene wax. The material was heated at 108℃ and 120rpm for 6 minutes. After discharge, it was transferred to a mixer and stirred at room temperature for another 10 minutes at 120rpm. After stirring, it was sealed and matured for 6 hours. The resulting product was transferred to a twin-screw extruder with the screw speed set at 15rpm, the feeding section temperature at 160℃, the compression section temperature at 168℃, the plasticizing section temperature at 176℃, the metering section temperature at 182℃, the connecting body temperature at 186℃, and the die temperature at 188℃. Then, a two-stage cooling and sizing process was used, with the first sizing water temperature at 28℃ and the second at 20℃, to produce a high-mechanical-strength modified CPVC cable protection pipe.

[0035] Example 3:

[0036] Raw materials (parts by weight): 100 parts CPVC resin, 1.6 parts additives, 4 parts additives, 2.2 parts stabilizer, 0.35 parts aluminum magnesium hydrotalcite, 0.55 parts lubricant, 0.2 parts calcium stearate, 0.3 parts oxidized polyethylene wax, 0.35 parts antioxidant, 0.5 parts rutile titanium dioxide, and 0.1 parts pigment; CPVC resin: chlorine content is 68.5%, and the original degree of polymerization of PVC is 900; Additives: 0.6% methacrylic acid, 4% n-butyl acrylate, 8% ethyl acrylate, with the remainder supplemented to 100% by methyl methacrylate; CPE-g-GMA: CPE has a chlorine content of 38%, and the effective grafting rate of GMA is 1.5%; Stabilizer: Methyltin thiolate salt is selected; Lubricant: Pentaerythritol stearate is selected; Antioxidant: Prepared by mixing antioxidant 168 and antioxidant 1010 at a mass ratio of 1:0.5.

[0037] Preparation method: Preparation of additives: S1: Material pretreatment. The materials selected are acicular wollastonite, nano boehmite, and CPE-g-GMA. The raw materials are pretreated and ready for use. S2: Blending treatment, the pretreated raw materials are blended to obtain the additive.

[0038] The material pretreatment method is as follows: acicular wollastonite is dried at 110℃ for 3.5h, nano-boehmite is dried at 115℃ for 3.5h, and CPE-g-GMA is dried at 65℃ for 2h to complete the pretreatment of each raw material and obtain dried acicular wollastonite, nano-boehmite, and CPE-g-GMA.

[0039] The blending process is as follows: Weigh dried wollastonite and nano-boehmite, mix them in a low-speed mixer at 150 rpm for 20 minutes to obtain a premix. The dried CPE-g-GMA is fed into a twin-screw extruder through the main feed port, and then the premix is ​​fed in through the side feed port. After extrusion, it is hot-cut into 1.5 mm particles to obtain the additive.

[0040] The mass ratio of dried wollastonite, nano-boehmite, and CPE-g-GMA is 4.5:1:1.3. During the blending process, the temperature of the feeding section is set to 115℃, the temperature of the conveying section is set to 125℃, the temperature of the first mixing section is set to 145℃, the temperature of the second mixing section is set to 155℃, the temperature of the homogenization section is set to 160℃, and the temperature of the die head is set to 155℃.

[0041] Preparation of high-mechanical-strength modified CPVC cable protection pipe: Weigh CPVC resin, additives, aluminum-magnesium hydrotalcite, and antioxidant, and stir at 60 rpm for 8 minutes, then at 300 rpm for 12 minutes, controlling the material temperature at 50℃. Add stabilizer, and continue mixing at 300 rpm for 12 minutes. When the material temperature reaches 70℃, add additives, rutile titanium dioxide, and pigments, and mix at 350 rpm for 18 minutes. When the material temperature reaches 85℃, add lubricant, and mix at 350 rpm for 18 minutes. When the material temperature reaches 100℃, add calcium stearate and oxidized polyethylene wax. The material was hot-mixed at 112℃ and 180 rpm for 10 minutes. After discharge, it was transferred to a mixer and stirred at room temperature at 180 rpm for 20 minutes. After stirring, it was sealed and matured for 12 hours. The resulting product was transferred to a twin-screw extruder with the screw speed set at 25 rpm, the feeding section temperature at 168℃, the compression section temperature at 176℃, the plasticizing section temperature at 184℃, the metering section temperature at 190℃, the connecting body temperature at 192℃, and the die temperature at 194℃. Then, a two-stage cooling and sizing process was used, with the first sizing water temperature at 32℃ and the second at 25℃, to produce a high-mechanical-strength modified CPVC cable protection pipe.

[0042] Comparative Example 1: Raw materials (parts by weight): Same as in Example 1; CPVC resin: Same as in Example 1; Additives: Same as in Example 1; Stabilizer: Same as in Example 1; Lubricant: Same as in Example 1; Antioxidant: Same as in Example 1.

[0043] Additives: CPE with a chlorine content of 35% is selected.

[0044] Preparation method: Preparation of additives: None.

[0045] Preparation of high mechanical strength modified CPVC cable protection pipe: same as in Example 1.

[0046] Comparative Example 2: Raw materials (parts by weight): Same as in Example 1; CPVC resin: Same as in Example 1; Additives: Same as in Example 1; Stabilizer: Same as in Example 1; Lubricant: Same as in Example 1; Antioxidant: Same as in Example 1; Additive: Needle-shaped wollastonite is selected.

[0047] Preparation method: Preparation of additives: None.

[0048] Preparation of high mechanical strength modified CPVC cable protection pipe: same as in Example 1.

[0049] Comparative Example 3: Raw materials (parts by weight): Same as in Example 1; CPVC resin: Same as in Example 1; Additives: Same as in Example 1; CPE-g-GMA: Same as Example 1; Stabilizer: Same as in Example 1; Lubricant: Same as in Example 1; Antioxidant: Same as in Example 1.

[0050] Preparation method: Preparation of additives: S1: Material pretreatment. The materials selected are needle-shaped wollastonite, nano-boehmite, and CPE-g-GMA. The raw materials are pretreated and ready for use.

[0051] The material pretreatment method is as follows: acicular wollastonite is dried at 108℃ for 3.2h, nano-boehmite is dried at 112℃ for 3.2h, and CPE-g-GMA is dried at 60℃ for 1.5h. The pretreatment of each raw material is completed to obtain dried acicular wollastonite, nano-boehmite, and CPE-g-GMA.

[0052] The mass ratio of dried wollastonite, nano-boehmite, and CPE-g-GMA is 4.25:1:1.25.

[0053] Preparation of high-mechanical-modified CPVC cable protection pipe: Weigh CPVC resin, additives, aluminum-magnesium hydrotalcite, and antioxidant, and stir at 50 rpm for 6 minutes, then at 250 rpm for 10 minutes, controlling the material temperature at 45℃. Add stabilizer, and continue mixing at 250 rpm for 10 minutes. When the material temperature reaches 65℃, add dried needle-like wollastonite, nano-boehmite, CPE-g-GMA, rutile titanium dioxide, and pigment, and mix at 300 rpm for 15 minutes. When the material temperature reaches 80℃, add lubricant, and mix at 300 rpm for 15 minutes. When the material temperature reaches 98℃, add hardener. Calcium fatty acid and oxidized polyethylene wax were hot-mixed at 110℃ and 150 rpm for 8 minutes. After discharge, the mixture was transferred to a mixer and stirred at room temperature for another 15 minutes at 150 rpm. After stirring, the mixture was sealed and cured for 8 hours. The resulting product was then transferred to a twin-screw extruder with the screw speed set at 20 rpm, the feeding section temperature at 164℃, the compression section temperature at 172℃, the plasticizing section temperature at 180℃, the metering section temperature at 186℃, the connecting body temperature at 189℃, and the die temperature at 191℃. A two-stage cooling and sizing process was then used, with the first sizing water temperature at 30℃ and the second at 22℃, to produce a high-mechanical-strength modified CPVC cable protection pipe.

[0054] Performance testing: The CPVC cable protection pipes prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance testing.

[0055] Table 1: Performance test data for each embodiment and comparative example

[0056] In the performance test, the CPVC cable protection pipes prepared in Examples 1-3 and Comparative Examples 1-3 were tested. The cantilever beam notched impact strength was tested with reference to ASTM D256-2024, and the bending strength was tested with reference to ASTM D790. Analysis of the data in Table 1 shows that, according to the data from Examples 1-3, the notched impact strength of the cantilever beam is 108-115 J / m, and the flexural strength is 81.5-82.3 MPa. The differences in these three values ​​are small, indicating that the material has both high impact resistance and high flexural strength, achieving a good balance between rigidity and toughness. In contrast, Comparative Example 1 only has the elastomer CPE without the reinforcing effect of acicular wollastonite and nano-boehmite. The impact strength increases to 135 J / m, but the flexural strength drops to 62.5 MPa, indicating a severe deterioration in rigidity. Comparative Example 2 only has the rigid filler acicular wollastonite without the toughening effect of the CPE-g-GMA elastomer phase. The flexural strength increases to 86.8 MPa, but the impact strength drops sharply to 45 J / m, indicating a significant increase in material brittleness. Comparative Example 3 only undergoes pretreatment without blending, and the additive components are simply dry-mixed without forming organic-inorganic composite microparticles. The synergistic effect is greatly reduced, and the impact strength drops to 72 J / m and the flexural strength drops to 75.6 MPa. Both of these properties are significantly inferior to those of the Examples.

[0057] This indicates that in this invention, the additive is pre-formed into organic-inorganic composite microparticles by blending and extruding acicular wollastonite, nano-boehmite, and CPE-g-GMA, and then added to the CPVC matrix. The CPE-g-GMA elastomer phase in these composite microparticles can form stress concentration points when the material is subjected to external impact, absorbing and dissipating impact energy through elastic deformation, thereby improving the toughness of the pipe. The fibrous structure of acicular wollastonite can form a micro-skeleton in the matrix, bearing the load and improving the resistance to deformation. The nano-filling effect of nano-boehmite can enhance the density of the matrix. The three work synergistically to significantly improve the impact resistance of the pipe while maintaining good rigidity. This solves the problem that in the prior art, simple blending of elastomer toughening and rigid filler reinforcement is difficult to achieve complementary advantages, thus achieving the goal of simultaneously achieving high rigidity and high toughness.

[0058] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-mechanical-strength modified CPVC cable protection pipe, characterized in that: The raw materials include the following parts by weight: 100 parts CPVC resin, 1-1.6 parts additives, 3-4 parts additives, 1.5-2.2 parts stabilizer, 0.15-0.35 parts aluminum magnesium hydrotalcite, 0.35-0.55 parts lubricant, 0.1-0.2 parts calcium stearate, 0.2-0.3 parts oxidized polyethylene wax, 0.15-0.35 parts antioxidant, 0.2-0.5 parts rutile titanium dioxide, and 0.08-0.1 parts pigment; The additive is prepared by the following method: S1: Material pretreatment. The materials selected are acicular wollastonite, nano boehmite, and CPE-g-GMA. The raw materials are pretreated and ready for use. S2: Blending treatment, the pretreated raw materials are blended to obtain the additive.

2. The high mechanical strength modified CPVC cable protection pipe according to claim 1, characterized in that, The material pretreatment method is as follows: acicular wollastonite is dried at 105-110℃, nano-boehmite is dried at 110-115℃, and CPE-g-GMA is dried at 55-65℃ to complete the pretreatment of each raw material and obtain dried acicular wollastonite, nano-boehmite, and CPE-g-GMA.

3. The high mechanical strength modified CPVC cable protection pipe according to claim 1, characterized in that, The blending process is as follows: dried wollastonite and nano-boehmite are weighed and mixed in a low-speed mixer to obtain a premix. Dried CPE-g-GMA is fed into a twin-screw extruder through the main feed port, and then the premix is ​​fed in through the side feed port. After extrusion, it is hot-cut into particles of 0.5-1.5 mm to obtain the additive.

4. The high mechanical strength modified CPVC cable protection pipe according to claim 2, characterized in that, The mass ratio of dried wollastonite, nano-boehmite, and CPE-g-GMA is 4-4.5:1:1.2-1.

3.

5. The high mechanical strength modified CPVC cable protection pipe according to claim 1, characterized in that, In the blending process, the temperature of the feeding section is set to 110-115℃, the temperature of the conveying section is set to 120-125℃, the temperature of the first mixing section is set to 140-145℃, the temperature of the second mixing section is set to 150-155℃, the temperature of the homogenization section is set to 155-160℃, and the temperature of the die head is set to 150-155℃.

6. The high mechanical strength modified CPVC cable protection pipe according to claim 1, characterized in that, The additive comprises: 0.2-0.6% methacrylic acid, 1.5-4% n-butyl acrylate, 4-8% ethyl acrylate, with the remainder supplemented by methyl methacrylate to bring the total to 100%.

7. The high mechanical strength modified CPVC cable protection pipe according to claim 1, characterized in that, The CPE in the CPE-g-GMA has a chlorine content of 32-38% and an effective grafting rate of GMA of 0.8-1.5%.

8. The high mechanical strength modified CPVC cable protection pipe according to claim 1, characterized in that, The CPVC resin has a chlorine content of 67-68.5% and an original PVC degree of polymerization of 700-900.

9. The high mechanical strength modified CPVC cable protection pipe according to claim 1, characterized in that, The stabilizer is selected from methyltin thiolate, the lubricant is selected from pentaerythritol stearate, and the antioxidant is prepared from antioxidant 168 and antioxidant 1010.

10. The method for preparing the high mechanical strength modified CPVC cable protection pipe according to any one of claims 1-9, characterized in that, Includes the following steps: Weigh out CPVC resin, additives, aluminum-magnesium hydrotalcite, and antioxidants, and mix them sequentially at low and high speeds, controlling the material temperature at 40-50℃. Add stabilizer and continue high-speed mixing. When the material temperature reaches 60-70℃, add additives, rutile titanium dioxide, and pigments, and continue high-speed mixing. When the material temperature reaches 75-85℃, add lubricant and continue high-speed mixing. When the material temperature reaches 95-100℃, add calcium stearate and oxidized polyethylene wax, and perform hot mixing at 108-112℃. After discharge, transfer the mixture to a mixer and continue mixing at room temperature. After stirring, the mixture is sealed and matured for 6-12 hours. The resulting product is then transferred to a twin-screw extruder. The feeding section temperature is 160-168℃, the compression section temperature is 168-176℃, the plasticizing section temperature is 176-184℃, the metering section temperature is 182-190℃, the connecting body temperature is 186-192℃, and the die temperature is 188-194℃. Subsequently, a two-stage cooling and sizing process is adopted. The first sizing water temperature is 28-32℃, and the second stage is 20-25℃, thus producing a high-mechanical-strength modified CPVC cable protection pipe.

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