Super strong pressure-resistant HPVC pipe and preparation method thereof

Abstract

The application relates to the technical field of polyvinyl chloride pipes, in particular to a super compression-resistant HPVC pipe and a preparation method thereof. The super compression-resistant HPVC pipe comprises the following raw materials in parts by weight: 60-90 parts of polyvinyl chloride resin, 10-30 parts of modified resin, 5-12 parts of a filling agent, 1-5 parts of a heat stabilizer, 2-3 parts of a processing modification aid, 1-2 parts of a lubricant and 0.5-1 part of an impact modification aid. The super compression-resistant HPVC pipe has excellent compression resistance and can be used in different environments, thereby increasing the use range of the HPVC pipe.

Description

A high-strength, pressure-resistant HPVC pipe and its preparation method Technical Field

[0001] This invention relates to the field of polyvinyl chloride pipe technology, and in particular to an ultra-strong pressure-resistant HPVC pipe and its preparation method. Background Technology

[0002] PVC was once the world's most produced general-purpose plastic, with extremely wide applications. It is widely used in building materials, industrial products, daily necessities, linoleum, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, and fibers. In the pipe sector, PVC pipes possess excellent properties such as light weight, high mechanical strength, chemical resistance, corrosion resistance, chemical resistance, heat insulation, and electrical insulation. They also have a long lifespan and are inexpensive, making them widely used in construction engineering, transportation engineering, environmental engineering, energy and water conservancy projects, and more.

[0003] HPVC pipes are generally used for the protection of buried communication optical (electrical) cables and power cables in various construction fields such as outdoor bridge cladding, tunnels, light rail, airports, subways, stadiums, and real estate, and can replace plastic-coated or galvanized steel pipes. However, current HPVC solid-wall pipes are prone to cracking in some outdoor applications, such as road construction compaction and excavation, especially at low temperatures. Under such conditions, the pipes are more likely to crack or even break, affecting their usability. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an ultra-high pressure resistant HPVC pipe and its preparation method, so that the HPVC pipe has excellent pressure resistance and can also adapt to different environments, thereby increasing the application range of HPVC pipe.

[0005] The present invention solves the above-mentioned technical problems through the following technical means:

[0006] A super-strong pressure-resistant HPVC pipe comprises the following raw materials in parts by weight: 60-90 parts of polyvinyl chloride resin, 10-30 parts of modified resin, 5-12 parts of filler, 1-5 parts of heat stabilizer, 2-3 parts of processing modifier, 1-2 parts of lubricant, and 0.5-1 parts of impact modifier.

[0007] Modifying polyvinyl chloride (PVC) with modified resins and fillers can greatly enhance the compressive strength of PVC pipes. Furthermore, the synergistic effect of impact modifiers further enhances the compressive strength of PVC pipes. By selecting appropriate processing aids, the processing performance of PVC pipes can be improved, preventing the formation of blemishes.

[0008] Preferably, the polyvinyl chloride resin has a K value of 60-68 and a viscosity of 60-200 ml / g.

[0009] More preferably, the polyvinyl chloride resin has a K value of 66-68, a degree of polymerization of 970-1070, and a viscosity of 80-160 ml / g.

[0010] By using polyvinyl chloride resin with a KK value of 66-68 and a viscosity of 80-160 ml / g, the resin melt exhibits better flowability and plasticity while possessing superior tensile properties and impact strength, making it more suitable for processing.

[0011] Preferably, the modified resin is a mixture of chlorinated polyethylene and chlorinated polyvinyl chloride, wherein the mass ratio of chlorinated polyethylene to chlorinated polyvinyl chloride is 1:(0.2-0.5).

[0012] Chlorinated polyethylene (CPE) possesses excellent weather resistance, ozone resistance, chemical resistance, and aging resistance. It also exhibits good oil resistance, flame retardancy, and colorability. It has good toughness (remaining flexible at -30℃) and good compatibility with other polymers. Furthermore, it is an excellent impact modifier for PVC plastics. Chlorinated polyvinyl chloride (PVC) is a further chlorination modification of PVC. It not only retains the properties of PVC but also improves its heat resistance, resistance to corrosion from acids, alkalis, salts, and oxidants, as well as its resin solubility and heat distortion temperature.

[0013] By using chlorinated polyethylene and chlorinated polyvinyl chloride as modified resins, the impact resistance, low-temperature flexibility and heat resistance of polyvinyl chloride can be improved. In addition, chlorinated polyethylene and chlorinated polyvinyl chloride are well compatible with polyvinyl chloride resin, which is beneficial to improving processing performance.

[0014] The preferred mass ratio of chlorinated polyethylene to chlorinated polyvinyl chloride is 1:0.4. By controlling the mass ratio of chlorinated polyethylene to chlorinated polyvinyl chloride, it is beneficial to highlight the impact resistance of polyvinyl chloride.

[0015] Preferably, the filler is modified basalt fiber and silica, and the preparation of the filler includes the following steps:

[0016] B1. Place the basalt fiber in a dilute acid solution and stir for 4-8 hours. After stirring, wash and dry to obtain the pretreated basalt fiber.

[0017] B2. The pretreated basalt fibers are surface modified by low-temperature plasma to obtain modified basalt fibers;

[0018] B3. Pre-disperse silica in water to form a slurry, then place modified basalt fiber in the slurry, add silane coupling agent, stir for 3-7 hours, wash, and dry to obtain the filler.

[0019] Basalt fiber has high strength, as well as excellent properties such as electrical insulation, corrosion resistance, high temperature resistance, oxidation resistance, radiation resistance, heat insulation and sound insulation, high compressive strength and shear strength, and adaptability to use in various environments. By first cleaning the surface of the basalt fiber and then treating it with low-temperature plasma, the surface energy of the basalt fiber is increased, which is beneficial to the use of basalt fiber with other materials.

[0020] Silica is heat-resistant, non-flammable, tasteless, odorless, and has excellent electrical insulation properties. It can also be used as a reinforcing agent and thickener. However, silica has a large specific surface area and small particle size, which makes it easy to fly away during use and disperse unevenly in resins, forming granules.

[0021] In this scheme, basalt fiber is preferably basalt short fiber with a single filament diameter of 10-15 μm. First, the silica is dispersed to form a slurry, and then crosslinked with the surface-treated basalt fiber, which is beneficial to the use of silica and its dispersion in the resin.

[0022] Preferably, in step S2, the conditions for low-temperature plasma treatment are: using air as the working gas, a pressure of 50 Pa, and a discharge power of 150 W for 5-10 minutes of low-temperature plasma treatment.

[0023] Preferably, the silica is one of precipitated silica, fumed silica, and ultrafine silica gel.

[0024] Further preferred, fumed silica is preferred.

[0025] Preferably, in steps S1 and S3, the drying conditions are as follows: baking at 80-100°C for 2-5 hours.

[0026] Preferably, the heat stabilizer is an environmentally friendly calcium-zinc stabilizer, the processing modifier is a methyl methacrylate copolymer, the impact modifier is one of ARC impact modifier, MBS impact modifier, methyl methacrylate-butadiene-styrene graft copolymer, chlorinated polyethylene, and ethylene-vinyl acetate copolymer, and the lubricant is one or a combination of stearic acid, oxidized polyethylene wax, polyethylene wax, glyceryl monostearate, glyceryl distearate, or pentaerythritol monostearate.

[0027] A further preferred impact modifier is a methyl methacrylate-butadiene-styrene graft copolymer, which can further improve the impact resistance of PVC pipes and can synergistically work with processing modifiers to further improve processing performance.

[0028] More preferably, the lubricant is polyethylene wax and glyceryl monostearate, wherein polyethylene wax is used as an external lubricant and glyceryl monostearate is used as an internal lubricant, and the mass ratio of polyethylene wax to glyceryl monostearate is 1:1.

[0029] This application also discloses a method for preparing a high-strength, pressure-resistant HPVC pipe, comprising the following steps:

[0030] A1. Add the modified resin to a high-speed mixer and stir until homogeneous. Then add the filler and stir until homogeneous to obtain a premix.

[0031] A2. Add polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add heat stabilizer, processing modifier, lubricant and impact modifier, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0032] A3. Add the masterbatch to a single-screw extruder, extrude, and cool to obtain a high-strength, pressure-resistant HPVC pipe.

[0033] By first preparing a premix by mixing chlorinated polyethylene, chlorinated polyvinyl chloride, modified basalt fiber, and silica, the chlorinated polyethylene can be fully combined with silica and basalt fiber, and silica and basalt fiber can form a network skeleton and combine with chlorinated polyvinyl chloride, thereby improving the bonding performance and impact resistance of the two and reducing the impact on processing performance. As a result, when the premix is ​​melt-blended with polyvinyl chloride, the impact resistance of polyvinyl chloride pipes can be improved.

[0034] Preferably, in step A3, the rotational speed of the single-screw extruder is 250-350 r / min.

[0035] Further preferably, the rotational speed of the single-screw extruder is 320 r / min.

[0036] The invention employing the above-described solution has the following beneficial effects:

[0037] 1. By adding modified resins and processing aids to polyvinyl chloride (PVC), the compressive strength and processing performance of PVC pipes can be improved. The addition of modified basalt fiber and silica further improves the compressive strength of PVC pipes and also improves their impact resistance at low temperatures, thus expanding the application range of PVC pipes.

[0038] 2. By first mixing the modified resin and the filler, on the one hand, the potential problems caused by the filler during use can be avoided, and on the other hand, the chlorinated polyethylene can be fully combined with the silica and basalt fiber, and the silica and basalt fiber can form a network skeleton and combine with the chlorinated polyvinyl chloride, thereby improving the bonding performance and impact resistance of the two, reducing the impact on processing performance, and thus enhancing the compressive strength of the polyvinyl chloride pipe. Detailed Implementation

[0039] 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:

[0040] Example 1: Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0041] In this embodiment, the polyvinyl chloride (PVC) used is from Qilu Petrochemical, grade S-1000, with a K value of 66-68 and a viscosity of 80-160 ml / g; the mass ratio of chlorinated polyethylene (PE) to chlorinated PVC is 1:0.4, wherein the chlorinated polyethylene is from Zhongqiao Chemical, grade CPE-135A; the chlorinated PVC is from Shandong Ketian Chemical, grade CPVC J-700; and the silica is silica Q702.

[0042] Preparation of fillers

[0043] B1. Place 10 parts by mass of basalt fiber in a 0.2 mol / L dilute hydrochloric acid solution and stir for 4 hours. After stirring, wash with soft water 3-5 times and then bake in an oven at 80°C for 3 hours to obtain pretreated basalt fiber.

[0044] B2. Ten parts by mass of pretreated basalt fiber were surface modified by low-temperature plasma. The conditions for low-temperature plasma treatment were: air as working gas, pressure of 50 Pa, discharge power of 150 W, and low-temperature plasma treatment for 5-10 min to obtain modified basalt fiber.

[0045] B3. Disperse 5 parts by weight of silica in 10 parts by weight of soft water to form a slurry. Then place 5 parts by weight of modified basalt fiber in the slurry, add 0.5 parts by weight of silane coupling agent, stir for 3 hours, wash with soft water 3-5 times, and then bake in an oven at 80°C for 3 hours to obtain the filler.

[0046] Preparation of high-strength, pressure-resistant HPVC pipes

[0047] A1. Add 10 parts by weight of chlorinated polyethylene and 4 parts by weight of chlorinated polyvinyl chloride into a high-speed mixer, stir evenly, then add 5 parts by weight of filler, stir evenly to obtain a premix.

[0048] A2. Add 60 parts by weight of polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add 2 parts by weight of calcium-zinc stabilizer, 2 parts by weight of methyl methacrylate copolymer, 1 part by weight of polyethylene wax and glyceryl monostearate mixture and 0.5 parts by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0049] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0050] Example 2, Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0051] In this embodiment, the raw materials for polyvinyl chloride are the same as in Example 1; the mass ratio of chlorinated polyethylene and chlorinated polyvinyl chloride, as well as the raw materials, are the same as in Example 1; and the silica used is silica Q702.

[0052] Preparation of fillers

[0053] B1. Place 20 parts by weight of basalt fiber in a 0.2 mol / L dilute hydrochloric acid solution and stir for 6 hours. After stirring, wash with soft water 3-5 times and then bake in an oven at 80°C for 4 hours to obtain pretreated basalt fiber.

[0054] B2. 20 parts by mass of pretreated basalt fiber were surface modified by low-temperature plasma. The conditions for low-temperature plasma treatment were: air as working gas, pressure of 50 Pa, discharge power of 150 W, and low-temperature plasma treatment for 5-10 min to obtain modified basalt fiber.

[0055] B3. Disperse 10 parts by weight of silica in 20 parts by weight of soft water to form a slurry. Then place 10 parts by weight of modified basalt fiber in the slurry, add 1.0 part by weight of silane coupling agent, stir for 5 hours, wash with soft water 3-5 times, and then bake in an oven at 80°C for 4 hours to obtain the filler.

[0056] Preparation of high-strength, pressure-resistant HPVC pipes

[0057] A1. Add 15 parts by weight of chlorinated polyethylene and 6 parts by weight of chlorinated polyvinyl chloride into a high-speed mixer, stir evenly, then add 8 parts by weight of filler, stir evenly to obtain a premix.

[0058] A2. Add 80 parts by weight of polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt-blend, then add 3.6 parts by weight of calcium-zinc stabilizer, 2.5 parts by weight of methyl methacrylate copolymer, 1.6 parts by weight of polyethylene wax and glyceryl monostearate mixture and 0.8 parts by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0059] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0060] Example 3: Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0061] In this embodiment, the raw materials for polyvinyl chloride are the same as in Example 1; the mass ratio of chlorinated polyethylene and chlorinated polyvinyl chloride, as well as the raw materials, are the same as in Example 1; and the silica used is silica Q702.

[0062] Preparation of fillers

[0063] B1. Place 30 parts by weight of basalt fiber in a 0.2 mol / L dilute hydrochloric acid solution and stir for 8 hours. After stirring, wash with soft water 3-5 times and then bake in an oven at 80°C for 5 hours to obtain pretreated basalt fiber.

[0064] B2. 30 parts by mass of pretreated basalt fiber were surface modified by low-temperature plasma. The conditions for low-temperature plasma treatment were: air as working gas, pressure of 50 Pa, discharge power of 150 W, and low-temperature plasma treatment for 5-10 min to obtain modified basalt fiber.

[0065] B3. Disperse 20 parts by weight of silica in 35 parts by weight of soft water to form a slurry. Then place 15 parts by weight of modified basalt fiber in the slurry, add 1.8 parts by weight of silane coupling agent, stir for 7 hours, wash with soft water 3-5 times, and then bake in an oven at 80°C for 5 hours to obtain the filler.

[0066] Preparation of high-strength, pressure-resistant HPVC pipes

[0067] A1. Add 20 parts by weight of chlorinated polyethylene and 8 parts by weight of chlorinated polyvinyl chloride into a high-speed mixer, stir evenly, then add 12 parts by weight of filler, stir evenly to obtain a premix.

[0068] A2. Add 90 parts by weight of polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add 4.5 parts by weight of calcium-zinc stabilizer, 3 parts by weight of methyl methacrylate copolymer, 2 parts by weight of polyethylene wax and glyceryl monostearate mixture and 1 part by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0069] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0070] Example 4 (Comparative Example 1): Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0071] In this embodiment, the raw materials for polyvinyl chloride are the same as in Example 1; the mass ratio of chlorinated polyethylene and chlorinated polyvinyl chloride, as well as the raw materials, are the same as in Example 1; the silica used is silica Q702, and the mass ratio of basalt short fibers to silica is 1:1.

[0072] Preparation of high-strength, pressure-resistant HPVC pipes

[0073] A1. Add 20 parts by weight of chlorinated polyethylene and 8 parts by weight of chlorinated polyvinyl chloride into a high-speed mixer and stir evenly. Then add 12 parts by weight of a mixture of silica and basalt short fibers and stir evenly to obtain a premix.

[0074] A2. Add 90 parts by weight of polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add 4.5 parts by weight of calcium-zinc stabilizer, 3 parts by weight of methyl methacrylate copolymer, 2 parts by weight of polyethylene wax and glyceryl monostearate mixture and 1 part by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0075] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0076] Example 5 (Comparative Example 2): Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0077] In this embodiment, the raw materials for polyvinyl chloride are the same as in Example 1; the mass ratio of chlorinated polyethylene and chlorinated polyvinyl chloride, as well as the raw materials, are the same as in Example 1; and basalt short fibers are used as the filler.

[0078] A1. Add 20 parts by weight of chlorinated polyethylene and 8 parts by weight of chlorinated polyvinyl chloride into a high-speed mixer and stir evenly. Then add 12 parts by weight of basalt short fiber and stir evenly to obtain a premix.

[0079] A2. Add 90 parts by weight of polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add 4.5 parts by weight of calcium-zinc stabilizer, 3 parts by weight of methyl methacrylate copolymer, 2 parts by weight of polyethylene wax and glyceryl monostearate mixture and 1 part by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0080] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0081] Example 6 (Comparative Example 3): Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0082] In this embodiment, the raw materials for polyvinyl chloride are the same as in Example 1; the mass ratio of chlorinated polyethylene and chlorinated polyvinyl chloride, as well as the raw materials, are the same as in Example 1; and silica is used as the filler.

[0083] A1. Add 20 parts by weight of chlorinated polyethylene and 8 parts by weight of chlorinated polyvinyl chloride into a high-speed mixer and stir evenly. Then add 12 parts by weight of fumed silica and stir evenly to obtain a premix.

[0084] A2. Add 90 parts by weight of polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add 4.5 parts by weight of calcium-zinc stabilizer, 3 parts by weight of methyl methacrylate copolymer, 2 parts by weight of polyethylene wax and glyceryl monostearate mixture and 1 part by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0085] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0086] Example 7 (Comparative Example 4): Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0087] In this embodiment, the polyvinyl chloride used is Qilu Petrochemical, grade S-1000, with a K value of 66-68 and a viscosity of 80-160 ml / g; the modified resin used is chlorinated polyethylene, which is Zhongqiao Chemical, CPE-135A; and the filler used is the filler prepared in Example 3.

[0088] Preparation of high-strength, pressure-resistant HPVC pipes

[0089] A1. Add 20 parts by weight of chlorinated polyethylene into a high-speed mixer and stir evenly. Then add 12 parts by weight of filler and stir evenly to obtain a premix.

[0090] A2. Add 90 parts by weight of polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add 4.5 parts by weight of calcium-zinc stabilizer, 3 parts by weight of methyl methacrylate copolymer, 2 parts by weight of polyethylene wax and glyceryl monostearate mixture and 1 part by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch;

[0091] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0092] Example 8 (Comparative Example 5): Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0093] In this embodiment, the polyvinyl chloride used is Qilu Petrochemical, grade S-1000, with a K value of 66-68 and a viscosity of 80-160 ml / g; the filler used is the filler prepared in Example 3.

[0094] Preparation of high-strength, pressure-resistant HPVC pipes

[0095] A2. Add 90 parts by weight of polyvinyl chloride resin to a high-speed mixer and stir evenly. Add 20 parts by weight of chlorinated polyethylene and 12 parts by weight of filler, stir evenly, heat to 140-160℃, melt and blend, then add 4.5 parts by weight of calcium-zinc stabilizer, 3 parts by weight of methyl methacrylate copolymer, 2 parts by weight of polyethylene wax and glyceryl monostearate mixture and 1 part by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to a screw extruder, extrude and granulate to obtain masterbatch;

[0096] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0097] Example 9 (Comparative Example 6): Preparation of Ultra-Strong Pressure-Resistant HPVC Pipe

[0098] In this embodiment, the raw materials for polyvinyl chloride are the same as in Example 1; the mass ratio of chlorinated polyethylene and chlorinated polyvinyl chloride, as well as the raw materials, are the same as in Example 1.

[0099] Preparation of high-strength, pressure-resistant HPVC pipes

[0100] A2. Add 90 parts by weight of polyvinyl chloride resin to a high-speed mixer and stir evenly. Add 20 parts by weight of chlorinated polyethylene and 8 parts by weight of chlorinated polyvinyl chloride, stir evenly, heat to 140-160℃, melt and blend, then add 4.5 parts by weight of calcium-zinc stabilizer, 3 parts by weight of methyl methacrylate copolymer, 2 parts by weight of polyethylene wax and glyceryl monostearate mixture and 1 part by weight of methyl methacrylate-butadiene-styrene graft copolymer, mix evenly, transfer to a screw extruder, extrude and granulate to obtain masterbatch;

[0101] A3. At a temperature of 200℃, a single screw extruder is used to extrude and form the HPVC pipe at a screw speed of 320 r / min. After cooling, a high-strength, pressure-resistant HPVC pipe is obtained.

[0102] The physical properties of the HPVC pipes prepared in Examples 1-9 were tested.

[0103] Tensile strength was tested according to GB / T1040, Vicat softening point according to GB / T1633, longitudinal shrinkage rate according to GB / T6671-2001, and ring stiffness according to conventional test methods; each set of data was tested 5 times, and the average value was taken. The drop hammer impact test involved fixing the tubes of the above embodiments and comparative examples to the ground, then dropping a 20 kg conical hammer from a height of 5 m onto the tube, and the height from which the hammer caused the tube to break was determined as the drop hammer height. In this case, the higher the drop hammer height, the better the drop hammer strength.

[0104] The test results are shown in Table 1:

[0105]

[0106]

[0107] As can be seen from the data in Table 1, the HPVC pipes prepared in Examples 1-3 of this application have better tensile strength and drop hammer impact strength, and the Vicat softening point temperature and longitudinal shrinkage rate are significantly improved. In terms of overall performance, the HPVC pipe prepared in Example 3 has better tensile strength, Vicat softening point temperature and ring stiffness than ordinary PVC pipes.

[0108] A comparison of the data from Examples 3 and 4 shows that by modifying the filler, the tensile strength and low-temperature drop weight test of HPVC pipes can be improved, that is, the compressive strength of HPVC pipes can be improved.

[0109] A comparison of the data from Examples 3 and 5-6 shows that, by modifying the filler, the tensile strength, longitudinal shrinkage rate, and ring stiffness of HPVC pipes can be improved compared to using basalt fiber or silica alone, and the drop hammer test results are better.

[0110] A comparison of the data from Examples 3 and 7-9 shows that using a mixture of chlorinated polyethylene and chlorinated polyvinyl chloride, compared to using chlorinated polyethylene or chlorinated polyvinyl chloride alone, or not using either chlorinated polyethylene or chlorinated polyvinyl chloride, can improve the tensile strength, Vicat softening point temperature, and longitudinal shrinkage rate of HPVC pipes, and the drop weight test results are better.

[0111] The above provides a detailed description of the ultra-high pressure-resistant HPVC pipe and its preparation method provided by the present invention. The specific embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0112] It should be noted that: for experimental steps or conditions not specified in the examples, the procedures and conditions described in conventional experimental procedures in the literature of this art can be followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0113] The above examples are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by anyone under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

Claims

1. A high-strength, pressure-resistant HPVC pipe, characterized in that, The raw materials include the following parts by weight: 60-90 parts of polyvinyl chloride resin, 10-30 parts of modified resin, 5-12 parts of filler, 1-5 parts of heat stabilizer, 2-3 parts of processing modifier, 1-2 parts of lubricant, and 0.5-1 parts of impact modifier; the modified resin is a mixture of chlorinated polyethylene and chlorinated polyvinyl chloride, with a mass ratio of chlorinated polyethylene to chlorinated polyvinyl chloride of 1:(0.2-0.5); the filler is modified basalt fiber and silica, and the preparation of the filler includes the following steps: B1. Placing basalt fiber in a dilute acid solution and stirring for 4-8 hours. After stirring, washing and drying are performed to obtain pretreated basalt fiber. B2. The pretreated basalt fibers are surface modified by low-temperature plasma to obtain modified basalt fibers; B3. Pre-disperse silica in water to form a slurry, then place modified basalt fiber in the slurry, add silane coupling agent, stir for 3-7 hours, wash, and dry to obtain filler; the preparation method of the super-strong pressure-resistant HPVC pipe includes the following steps: A1. Put the modified resin into a high-speed mixer, stir evenly, then add filler, stir evenly to obtain premix; A2. Add polyvinyl chloride resin to the premix, stir evenly, heat to 140-160℃, melt and blend, then add heat stabilizer, processing modifier, lubricant and impact modifier, mix evenly, transfer to screw extruder, extrude and granulate to obtain masterbatch; A3. Add masterbatch to single screw extruder, extrude, cool to obtain ultra-strong pressure resistant HPVC pipe.

2. The high-strength, pressure-resistant HPVC pipe according to claim 1, characterized in that, The polyvinyl chloride resin has a K value of 60-68 and a viscosity of 60-200 ml / g.

3. The high-strength, pressure-resistant HPVC pipe according to claim 1, characterized in that, In step B2, the conditions for low-temperature plasma treatment are as follows: using air as the working gas, with a pressure of 50 Pa and a discharge power of 150 W, the low-temperature plasma treatment is carried out for 5-10 minutes.

4. The high-strength, pressure-resistant HPVC pipe according to claim 1, characterized in that, The silica is one of precipitated silica, fumed silica, and ultrafine silica gel.

5. The high-strength, pressure-resistant HPVC pipe according to claim 1, characterized in that, In steps B1 and B3, the drying conditions are as follows: baking at 80°C for 3-5 hours.

6. The high-strength, pressure-resistant HPVC pipe according to claim 1, characterized in that, The heat stabilizer is an environmentally friendly calcium-zinc stabilizer; the processing modifier is a methyl methacrylate copolymer; the impact modifier is one of ACR impact modifier, methyl methacrylate-butadiene-styrene graft copolymer, chlorinated polyethylene, and ethylene-vinyl acetate copolymer; and the lubricant is one or a combination of stearic acid, oxidized polyethylene wax, polyethylene wax, glyceryl monostearate, glyceryl distearate, or pentaerythritol monostearate.

7. The high-strength, pressure-resistant HPVC pipe according to claim 1, characterized in that, In step A3, the rotational speed of the single-screw extruder is 250-350 r / min.

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