Special toughening color master batch for PP-R pipe and preparation method of special toughening color master batch

Abstract

The invention discloses a special toughening color master batch for a PP-R pipe and a preparation method of the special toughening color master batch, the preparation method comprises the following steps: pre-drying, feeding, plasticizing, mixing and dispersing, homogenizing, exhausting, compressing and molding, the prepared toughening color master batch comprises 40-70% of toughening matrix resin, 20-45% of pigment, 5-7% of polyethylene wax, 1-3% of EBS, 0.5-1.5% of zinc stearate, 0.3-0.7% of antioxidant 1010 and 0.1-0.5% of antioxidant 168, the PP-R toughening master batch and the PP-R color master batch are combined into one, so that the problem of low-temperature brittleness of the PP-R material is solved, the physical shock resistance of the PP-R pipe at low temperature is improved, meanwhile, the modified material and the PP-R material are ensured to have good compatibility, and the material cannot crack due to phase separation under the condition of long-term pressure bearing.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and particularly relates to a toughening color masterbatch for PP-R pipes and a preparation method thereof. Background Art

[0002] As the mainstream pipeline for cold and hot water pipes, PP-R pipes have a series of advantages. However, PP-R pipes exhibit brittleness at low temperatures. Under external physical impact, the pipes are prone to cracking, and in severe cases, even fragmentation. This results in the fact that in the cold winter in the north, during transportation and construction, PP-R pipes are easily damaged due to external physical impact, and finally leakage problems occur during use.

[0003] At present, in order to solve the problem of low-temperature brittleness of PP-R pipes, the following two basic solutions are generally adopted to solve the above problems. The first is to eliminate the internal stress generated during the production of PP-R pipes by means of heat treatment annealing of PP-R pipes, so that the pipes are recrystallized, and the low-temperature brittleness of PP-R pipes is improved. The second is to modify by blending tough materials such as PPB, PE-RT, or POE with PP-R to increase the toughness of PP-R materials. For the first solution using heat treatment, generally, PP-R pipes need to be baked in a drying oven at about 90 - 110 °C for about 2 hours and then naturally cooled. This greatly reduces the production efficiency of PP-R pipes, and also greatly increases the production cost and energy consumption. For PP-R pipes after heat treatment, although the internal stress during production is eliminated, the crystallization state of PP-R pipes is improved, and the low-temperature brittleness of PP-R pipes is improved to a certain extent, but the improvement effect is limited, and essentially the low-temperature brittleness of PP-R pipes has not changed fundamentally. For the second solution, the compatibility between the toughening material and PP-R material is poor. Under the long-term pressure-bearing state of PP-R pipes, due to phase separation between materials, the mechanical properties of the materials decline, and cracking problems are prone to occur. This reduces the overall pressure-bearing capacity of PP-R pipes and cannot meet the long service life of 50 years. Therefore, it is necessary to propose a toughening color masterbatch for PP-R pipes and a preparation method thereof. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems in the background art and provide a preparation method for a toughening color masterbatch for PP-R pipes.

[0005] The above technical object of the present invention is achieved through the following technical solutions: A preparation method for a toughening color masterbatch for PP-R pipes includes the following steps: S1, pre-drying, drying the materials; S2, Feeding: Continuously and stably feed the toughened matrix resin into the screw through the main feeding section of the twin-screw extruder. The screw groove of this section of the screw is relatively deep to ensure that the material can smoothly enter the equipment and provide a stable material supply for subsequent processing. The temperature range of the feeding section is 140 - 160 °C; S3, Plasticization: The toughened matrix resin undergoes heating and shearing in the plasticization section of the twin-screw extruder and gradually melts. At the same time, it is preliminarily mixed with the added antioxidant 1010 and antioxidant 168, laying a foundation for further uniform mixing and dispersion. The temperature of the plasticization section is 170 - 200 °C; S4, Mixing and Dispersion: The pigment is fully mixed and dispersed with the plasticized material in the mixing section of the twin-screw extruder. Soon after the colorant is added, polyethylene wax and EBS are also added in the mixing section. The structural design of the mixing section usually has a strong shearing and kneading effect in this section, enabling the pigment to be evenly distributed in the resin matrix, achieving good coloring and functional addition effects. The temperature of the mixing section is 180 - 220 °C; S5, Homogenization: Then zinc stearate is added to the material in the homogenization section of the twin-screw extruder and fully mixed and dispersed. The temperature of the homogenization section is 170 - 200 °C; S6, Exhaust: Since the material contains moisture, air, or low-molecular volatile substances generated during the processing, and zinc stearate is a substance with certain hygroscopicity, in the exhaust section of the twin-screw extruder, adjust the size of the exhaust port according to requirements to fully discharge these substances to improve product quality; S7, Compression: After the previous homogenization and exhaust, the material is further compressed in the compression section, making the material more dense and preparing for subsequent granulation and forming. The screw groove of this section of the screw gradually becomes shallower, exerting a compression effect on the material and improving the density and uniformity of the material; S8, Forming: Extrude through the die head of the twin-screw extruder, then form by water-cooled pulling, and then cut to form the toughened color masterbatch.

[0006] In the present invention, the formulation of the toughening color masterbatch is added separately. The toughening matrix resin is used as the main material and continuously and stably added into the twin-screw granulation equipment through the main feeding port. The barrel temperature is usually set at 140 - 160 °C, which can gradually preheat Hifax CA 10 A during transportation to prepare for subsequent melting. It forms a material matrix, and other subsequent components are mixed and dispersed on this basis. When Hifax CA 10 A enters the melting and plasticizing zone, the temperature rises to 170 - 200 °C. At this time, antioxidants 1010 and 168 are added through the side feeding port. At this stage, the resin begins to melt, and the antioxidants can quickly mix with the resin and play an antioxidant role in a timely manner during high-temperature processing to protect the resin molecular chain from oxidative degradation. After the material is basically melted and plasticized, it enters the mixing and dispersing zone, where the temperature is maintained at 180 - 220 °C. These pigments are added through the side feeding port. At this temperature, the resin has good fluidity, which is conducive to the uniform dispersion of the colorant in the resin matrix to achieve a good coloring effect. Similarly, in the mixing and dispersing zone, shortly after the colorant is added, polyethylene wax and EBS are added through the side feeding port. As lubricants and dispersants, they can reduce the viscosity of the material melt, further promote the dispersion of additives such as the colorant, and improve the fluidity and mixing uniformity of the material. In the homogenization and degassing zone, the temperature is generally 170 - 200 °C, and zinc stearate is added through the side feeding port. At this stage, the material is fully mixed, and zinc stearate plays a role in lubrication, demolding, and thermal stability. At the same time, during the degassing process, it helps to discharge the gas and volatiles in the material, thereby improving the dispersion effect of the product and enhancing the quality and appearance of the product. During the production process, the addition amounts of various materials can be adjusted at any time according to needs. For some materials that require precise control of the addition amount, such as antioxidant 1010, antioxidant 168, etc., separate addition can better achieve precise metering and addition.

[0007] A toughening color masterbatch special for PP-R pipes, comprising 40 - 70% by weight of toughening matrix resin, 20 - 45% by weight of pigments, 5 - 7% by weight of polyethylene wax, 1 - 3% by weight of EBS, 0.5 - 1.5% by weight of zinc stearate, 0.3 - 0.7% by weight of antioxidant 1010, and 0.1 - 0.5% by weight of antioxidant 168.

[0008] Comprising 60.00% - 70.00% by weight of toughening matrix resin, 1.00% - 2.00% by weight of green powder, 1.50% - 2.50% by weight of yellow powder, 20.00% - 25.00% by weight of titanium dioxide, 0.10% - 0.30% by weight of carbon black powder, 5.00% - 7.00% by weight of polyethylene wax, 1.50% - 2.50% by weight of EBS, 0.50% - 1.50% by weight of zinc stearate, 0.30% - 0.50% by weight of antioxidant 1010, and 0.10% - 0.30% by weight of antioxidant 168.

[0009] The toughened matrix resin selected is a copolymer mainly composed of propylene, copolymerized with monomers such as ethylene and butene, with a melting point of about 140 °C and an elastic modulus lower than 200 MPa. Except for the Hifax CA 10 A grade, other resin grades of the same type only have different melt indexes. The performance indexes of the Hifax CA 10 A resin of Basell Company have a melting point of 142 °C, which is close to the melting point of PP-R resin. However, its elastic modulus is only 90 Ma, which is about one-ninth of that of PP-R resin.

[0010] The present invention combines the PP-R toughening masterbatch and the PP-R color masterbatch into one, which not only improves the low-temperature brittleness problem of PP-R materials, enhances the physical impact resistance of PP-R pipes at low temperatures, but also ensures good compatibility between the modified material and PP-R material. Under long-term pressure, the material will not crack due to phase separation. The long-term hydrostatic performance of PP-R pipes meets the relevant national standards, ensuring a 50-year service life of PP-R pipes. It can also dye PP-R pipes and prepare PP-R toughened color masterbatches of different colors.

[0011] The present invention also adds antioxidant 1010 and 168. Their synergistic effect can better prevent the oxidation and aging of the masterbatch during processing and use, extend the service life of the product. Through the action of polyethylene wax, EBS, zinc stearate, etc., the pigments can be better dispersed in the carrier. Compared with some ordinary existing masterbatches, by reasonably adjusting the dosage and proportion of these additives, a better dispersion effect can be achieved.

[0012] Preferably, the twin-screw extruder includes a heating barrel. The heating barrel is provided with a main feeding section, a plasticizing section, a mixing section, and a homogenizing section from left to right. Feed ports are provided on the main feeding section, the plasticizing section, the mixing section, and the homogenizing section, and uniform feeding mechanisms are provided on the feed ports. Two uniform feeding mechanisms are provided in the mixing section. An exhaust port is provided on the barrel wall of the heating barrel located in the homogenizing section, and an on-line stepless adjustable exhaust port mechanism is provided on the exhaust port. A sensor for monitoring the volatile content is provided near the exhaust port. The sensor for monitoring the volatile content can be a NIR sensor, and a vacuum exhaust system can be connected to the exhaust port.

[0013] By setting multiple uniform feeding mechanisms, different types of materials can enter the screw grooves of the twin-screw extruder evenly according to the preset ratio and speed. Under the rotation and shearing action of the screw, the materials can contact, mix, and disperse more fully, improving the performance uniformity and stability of the product, enhancing the mixing efficiency and quality, reducing product performance defects caused by uneven mixing, and also reducing the pressure fluctuation during the extrusion process, avoiding defects such as uneven product thickness, uneven surface, or bubbles caused by unstable pressure.

[0014] In the present invention, the volatile content sensor continuously monitors the volatile content at the exhaust port, and transmits the data to the control system in real time. The control system receives the volatile concentration data provided by the volatile content sensor and compares it with a preset target value. If the volatile concentration is higher than the target value, the control system determines that the exhaust volume needs to be increased; if the volatile concentration is lower than the target value, the control system determines that the exhaust volume needs to be decreased. Then, the control system adjusts the size of the exhaust port by driving the motor to ensure that the volatile concentration always remains within the target range. Through continuous monitoring and adjustment, precise control of volatile emissions is achieved, process parameters are optimized, and bubbles and voids in the product are reduced. Pigments and fillers such as green powder, yellow powder, titanium dioxide powder, and carbon black powder are sensitive to volatiles. Monitoring the volatile content ensures uniform dispersion of the pigments and fillers. Adjusting the size of the exhaust port avoids pigment aggregation or discoloration caused by excessive volatiles, improves product quality, and optimizes color and appearance.

[0015] Preferably, the online continuously adjustable exhaust port mechanism includes a fixed disk, a sliding adjustment piece, and a rotating moving disk. The fixed disk is fixedly connected to the exhaust port. The rotating moving disk is arranged above the fixed disk and inside the rotating moving disk. The sliding adjustment piece is arranged between the fixed disk and the rotating moving disk. An air outlet is provided in the middle of both the fixed disk and the rotating moving disk. A plurality of the sliding adjustment pieces are slidably arranged on the rotating moving disk. After the plurality of sliding adjustment pieces are spliced together, an adjustment port is formed at the tail end, and the adjustment port corresponds to the air outlet. A rotating gear is provided on the back of the rotating moving disk, and the rotating gear meshes with a driving gear. The driving gear is fixedly connected to a first rotating motor; A plurality of guiding through grooves are provided on the fixed disk, and a guiding annular groove is provided on the rotating moving disk. A guiding column that cooperates with the guiding through groove is provided at the bottom of the sliding adjustment piece, and a guiding block that cooperates with the guiding annular groove is provided at the top of the sliding adjustment piece.

[0016] The present invention controls the rotation of the motor, thereby controlling the rotation of the rotating moving disk, driving the sliding adjustment piece to slide in the guiding through groove and the guiding annular groove, thereby controlling the size of the adjustment port and achieving the function of adjusting the exhaust port.

[0017] Preferably, the uniform feeding mechanism includes a storage tank, a stirring disk with heating wires inside, a spiral conveyor, and a discharge pipe. The discharge pipe is arranged on the side wall of the storage tank and is in communication with the interior of the storage tank. The spiral conveyor is rotatably arranged at the inner bottom of the storage tank through a motor. One end of the spiral conveyor extends outside the storage tank, and the other end extends into the discharge pipe. Teeth are provided on the outer circle of the stirring disk, and the teeth are meshed with the spiral conveyor. The stirring disk is rotatably arranged on the side wall of the storage tank. A blanking pipe is provided at the end of the discharge pipe.

[0018] In the present invention, the rotation of the spiral conveyor promotes the uniform output of the materials in the storage box. At the same time, it drives the stirring wheel to continuously stir the powder in the container, drying the materials, enabling the automatic and uniform conveyance of the materials, allowing the materials to fully contact, mix, and disperse with each other, improving the performance uniformity and stability of the product. At the same time, by driving the spiral conveyor, both the spiral conveyor and the stirring wheel can be driven to rotate, saving energy.

[0019] Preferably, stirring rods are provided on both side walls of the stirring disk. A number of stirring rods are arrayed on the stirring disk. A guiding through-hole is provided in the middle of the stirring disk, enabling the flipping of the materials during the stirring of the stirring disk and improving the drying efficiency.

[0020] Preferably, a temperature sensor is provided in the storage tank. The stirring rods are made of heat-conducting materials, which can measure the temperature of the heating wires in real time and feedback the temperature signal to the controller. The controller compares the received temperature signal with the set temperature, and adjusts the control quantity according to the deviation value, such as adjusting the voltage, current, etc., to keep the temperature of the heating wires near the set value. This closed-loop control method can be automatically adjusted according to the actual temperature, with high control precision and stability.

[0021] Preferably, an exhaust mechanism is provided at the top of the storage tank. The exhaust mechanism includes an exhaust cavity in communication with the top of the storage tank. An inclined filter plate is provided in the exhaust cavity. An exhaust hole is provided at the lower right of the exhaust cavity, and the exhaust hole is connected to an exhaust pipe to reasonably process the dried gas. The inclined filter plate prevents the powder from being sucked into the exhaust pipe during the exhaust process.

[0022] The inclined filter plate includes two filter plates. A number of bouncing beads are provided between the two filter plates, and adjacent bouncing beads are separated by partition plates. A knocking mechanism is provided on the right side of the inclined filter plate. The knocking mechanism includes a second rotating motor, a rotating plate, a connecting rod, a piston, a fixed cylinder with a hollow interior, a knocking piece, and a connecting rod. The rotating plate is arranged on the output end of the second rotating motor. An eccentric hole is provided on the rotating plate. One end of the connecting rod is connected to the eccentric hole, and the other end is rotatably connected to the piston. The piston slides in the fixed cylinder, and the fixed cylinder is fixed on the inner wall of the exhaust cavity. The connecting rod is fixed to the end of the piston, and the knocking piece is fixed to the end of the connecting rod.

[0023] In the present invention, the first rotating motor drives the rotation of the rotating plate, thereby driving the eccentric hole to perform circular motion, and then transmitting it to the connecting rod. Since the piston can only move back and forth in the fixed cylinder, during the rotation of the rotating plate, the piston performs reciprocating motion back and forth, thereby driving the knocking piece to perform high-frequency linear vibration impact, causing the bouncing beads to bounce inside the filter plate, colliding with the filter plate, cleaning the holes of the inclined filter plate, enabling the powder to fall into the storage tank, and avoiding the blockage of the holes, which affects the exhaust.

[0024] In summary, the beneficial effects of the present invention are as follows: 1. The present invention combines the PP-R toughening masterbatch and the PP-R color masterbatch into one, which not only improves the low-temperature brittleness problem of the PP-R material, enhances the physical impact resistance of the PP-R pipe at low temperature, but also ensures good compatibility between the modified material and the PP-R material. Under long-term pressure, the material will not crack due to phase separation. The long-term hydrostatic performance of the PP-R pipe meets the relevant national standards, ensuring the 50-year service life of the PP-R pipe, and can also dye the PP-R pipe, and different colors of PP-R toughening color masterbatch can be prepared. 2. By adopting the method of separately adding the formula of the toughening color masterbatch in the present invention, the product is evenly mixed, improving the quality and appearance of the product. During the production process, the addition amount of various materials can be adjusted at any time according to needs. For some materials that require precise control of the addition amount, such as antioxidant 1010, antioxidant 168, etc., separate addition can better achieve precise metering and addition. 3. The present invention continuously monitors the volatile content at the exhaust port through a volatile content sensor, and transmits the data to the control system in real time. The control system receives the volatile concentration data provided by the volatile content sensor, compares it with a preset target value, and then adjusts the size of the exhaust port by driving a motor, ensuring that the volatile concentration always remains within the target range, reducing bubbles and voids in the product. Pigments and fillers such as green powder, yellow powder, titanium dioxide powder, and carbon black powder are sensitive to volatiles. By adjusting the size of the exhaust port, it is ensured that the pigments and fillers are evenly dispersed, avoiding pigment aggregation or discoloration caused by excessive volatiles, improving product quality, and optimizing color and appearance. 4. The present invention uniformly outputs the materials in the storage box by the rotation of the spiral conveyor rod, and at the same time drives the stirring wheel to continuously stir the powder in the container to dry the materials, enabling the automatic and uniform conveyance of the materials, allowing the materials to fully contact, mix, and disperse with each other, improving the performance uniformity and stability of the product. At the same time, by driving the spiral conveyor rod, both the spiral conveyor rod and the stirring wheel can be driven to rotate, saving energy. 5. The present invention drives the rotation of the rotating plate through the first rotating motor, thereby driving the eccentric hole to perform circular motion, and then transmitting it to the connecting rod. Since the piston can only move back and forth in the fixed cylinder, when the rotating plate rotates, the piston performs reciprocating motion back and forth, driving the striking member to perform high-frequency linear vibration impacts, causing the bouncing beads to bounce inside the filter plate, colliding with the filter plate, cleaning the holes of the inclined filter plate, and enabling the powder to fall into the storage tank, avoiding blockage of the holes and affecting exhaust. Description of the Drawings

[0025] Figure 1 is a process schematic diagram of the twin-screw extruder of the present invention; Figure 2 is a schematic diagram of the online stepless adjustable exhaust port mechanism of the present invention with the rotating gear removed; Figure 3 is a cross-sectional schematic diagram of the online stepless adjustable exhaust port mechanism of the present invention; Figure 4 is a schematic diagram of the rotating moving disk of the present invention; Figure 5 is a schematic diagram of the fixed disk of the present invention; Figure 6 is a schematic diagram of the back of the rotating moving disk of the present invention; Figure 7 is a schematic diagram of the sliding adjusting piece of the present invention; Figure 8 is a cross-sectional schematic diagram of the uniform feeding mechanism of the present invention; Figure 9 is an overall schematic diagram of the uniform feeding mechanism of the present invention; Figure 10It is a schematic diagram of the present invention after removing the storage tank; Figure 11 It is a cross-sectional schematic diagram of the exhaust mechanism of the present invention; Figure 12 It is a schematic diagram of the knocking mechanism of the present invention; Figures 13 - 17 It is a schematic diagram of the inspection report of the PP-R pipe with toughened masterbatch of the present invention; Brief Description of the Drawings: 1. Twin-screw extruder; 2. Heating barrel; 21. Main feeding section; 22. Plasticizing section; 23. Mixing section; 24. Homogenizing section; 210. Feeding port; 3. Uniform feeding mechanism; 25. Exhaust port; 4. Online stepless adjustable exhaust port mechanism; 61. Fixed disk; 62. Sliding adjusting piece; 63. Rotating moving disk; 64. Air outlet; 65. Adjusting port; 66. Rotating gear; 67. Driving gear; 68. First rotating motor; 611. Guide through groove; 631. Guide annular groove; 621. Guide post; 622. Guide block; 31. Storage tank; 321. Heating wire; 32. Stirring disk; 35. Feeding pipe; 323. Stirring rod; 322. Guide through hole; 5. Exhaust mechanism; 51. Exhaust cavity; 52. Inclined filter plate; 53. Exhaust hole; 521. Filter plate; 522. Bouncing bead; 523. Partition board; 7. Knocking mechanism; 71. Second rotating motor; 72. Rotating plate; 73. Connecting rod; 74. Piston; 75. Fixed cylinder; 76. Knocking piece; 77. Connecting rod; 721. Eccentric hole. Detailed Embodiment

[0026] The following specific embodiments are only explanations of the present invention, and they do not limit the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0027] The present invention will be described in detail below with reference to the drawings by way of examples.

[0028] Embodiment 1

[0029] A preparation method of a toughened masterbatch special for PP-R pipes includes the following steps: S1. Pre-drying, drying the materials; S2. Feeding, continuously and stably feeding the toughened matrix resin into the screw through the main feeding section of the twin-screw extruder 1. The screw groove of this section of the screw is deeper to ensure that the materials can smoothly enter the equipment and provide a stable material supply for subsequent processing. The temperature range of the feeding section is 150°C; S3. Plasticization and toughening: The matrix resin is heated and sheared in the plasticization section of the twin-screw extruder 1 and gradually melted. At the same time, it is preliminarily mixed with the added antioxidant 1010 and antioxidant 168, laying a foundation for further uniform mixing and dispersion. The temperature of the plasticization section is 180°C. S4. Mixing and dispersion: The pigment is fully mixed and dispersed with the plasticized material in the mixing section of the twin-screw extruder 1. Shortly after the colorant is added, polyethylene wax and EBS are also added in the mixing section. The structural design of the mixing section usually has a strong shearing and kneading effect in this section, enabling the pigment to be evenly distributed in the resin matrix, achieving good coloring and functional addition effects. The temperature of the mixing section is 200°C. S5. Homogenization: Then, zinc stearate is added to the material in the homogenization section of the twin-screw extruder 1 and fully mixed and dispersed. The temperature of the homogenization section is 180°C. S6. Exhaust: Since the material contains moisture, air, or low-molecular volatile substances generated during the processing, and zinc stearate is a substance with a certain hygroscopicity, in the exhaust section of the twin-screw extruder 1, the size of the exhaust port is adjusted according to requirements to fully discharge these substances to improve the product quality. S7. Compression: After the previous homogenization and exhaust, the material is further compressed in the compression section, making the material more dense and preparing for subsequent granulation and molding. The screw groove of the screw in this section gradually becomes shallower, exerting a compression effect on the material and improving the density and uniformity of the material. S8. Molding: It is extruded through the die head of the twin-screw extruder 1, then water-cooled and drawn into strips for molding, and then cut to form the toughened color masterbatch.

[0030] As Figure 1 shown, the twin-screw extruder 1 includes a heating barrel 2. The heating barrel 2 is provided with a main feeding section 21, a plasticization section 22, a mixing section 23, and a homogenization section 24 from left to right. The main feeding section 21, the plasticization section 22, the mixing section 23, and the homogenization section 24 are all provided with feeding ports 210. Uniform feeding mechanisms 3 are provided on the feeding ports 210. Two uniform feeding mechanisms 3 are provided in the mixing section. An exhaust port 25 is provided on the barrel wall of the heating barrel 2 located in the homogenization section 24. An on-line stepless adjustable exhaust port mechanism 4 is provided on the exhaust port 25. A sensor for monitoring the volatile content is provided near the exhaust port 25. A vacuum exhaust system is connected to the exhaust port 25. The vacuum exhaust system is prior art and will not be elaborated in this case.

[0031] As Figures 2 - 7As shown in the figure, the online stepless adjustable exhaust port mechanism 6 includes a fixed disk 61, a sliding adjustment piece 62, and a rotating moving disk 63. The fixed disk 61 is fixedly connected to the exhaust port 25. The rotating moving disk 63 is arranged above the fixed disk 61 and inside the rotating moving disk 63. The sliding adjustment piece 62 is arranged between the fixed disk 61 and the rotating moving disk 63. An air outlet 64 is provided in the middle of both the fixed disk 61 and the rotating moving disk 63. A plurality of the sliding adjustment pieces 62 are slidably arranged on the rotating moving disk 63. After the plurality of the sliding adjustment pieces 62 are spliced with each other, an adjustment port 65 is formed at the tail end. The adjustment port 65 corresponds to the air outlet 64. A rotating gear 66 is provided on the back of the rotating moving disk 63. The rotating gear 66 meshes with a driving gear 67. The driving gear 67 is fixedly connected to a first rotating motor 68. A plurality of guiding through grooves 611 are provided on the fixed disk 61. A guiding annular groove 631 is provided on the rotating moving disk 63. A guiding column 621 that cooperates with the guiding through grooves 611 is provided at the bottom of the sliding adjustment piece 62. A guiding block 622 that cooperates with the guiding annular groove 631 is provided at the top of the sliding adjustment piece 62.

[0032] As Figures 8 - 10 shown in the figure, the uniform feeding mechanism 3 includes a storage tank 31, a stirring disk 32 with a heating wire 321 inside, a spiral conveyor 33, and a discharge pipe 34. The discharge pipe 34 is arranged on the side wall of the storage tank 31 and is in communication with the inside of the storage tank 31. The spiral conveyor 33 is rotatably arranged on the inner bottom of the storage tank 31 through a motor. One end of the spiral conveyor 33 extends outside the storage tank 31, and the other end extends into the discharge pipe 34. Teeth are provided on the outer ring of the stirring disk 32, and the teeth mesh with the spiral conveyor 33. The stirring disk 32 is rotatably arranged on the side wall of the storage tank 31. A blanking pipe 35 is provided at the end of the discharge pipe 34. Stirring rods 323 are provided on both side walls of the stirring disk 32. A plurality of the stirring rods 323 are arrayed on the stirring disk 32. A guiding through hole 322 is provided in the middle of the stirring disk 32. A temperature sensor is provided inside the storage tank 31. The stirring rods 323 are made of a heat-conducting material.

[0033] As Figures 11 - 12As shown, an exhaust mechanism 5 is provided at the top of the storage tank 31. The exhaust mechanism 5 includes an exhaust cavity 51 that communicates with the top of the storage tank 31. An inclined filter plate 52 is provided in the exhaust cavity 51. An exhaust hole 53 is provided at the lower right of the exhaust cavity 51. The inclined filter plate 52 includes two filter plates 521. A number of bouncing beads 522 are provided between the two filter plates 521. Adjacent bouncing beads 522 are separated by a partition plate 523. A knocking mechanism 7 is provided on the right side of the inclined filter plate 52. The knocking mechanism 7 includes a second rotating motor 71, a rotating plate 72, a connecting rod 73, a piston 74, a fixed cylinder 75 with a hollow interior, a knocking member 76, and a connecting rod 77. The rotating plate 72 is provided at the output end of the second rotating motor 71. An eccentric hole 721 is provided on the rotating plate 72. One end of the connecting rod 73 is connected to the eccentric hole 721, and the other end is rotatably connected to the piston 74. The piston 74 slides within the fixed cylinder 75, and the fixed cylinder 75 is fixed to the inner wall of the exhaust cavity 51. The connecting rod 67 is fixed to the end of the piston 74. The knocking member 76 is fixed to the end of the connecting rod 67.

[0034] Select a copolymer material copolymerized with ethylene and butene monomers with propylene as the main body as the main resin of the toughening color masterbatch. For example, Hifax CA10A resin from Basell and PP NS06 resin from SINOPEC Zhongke.

[0035] Mix the toughening matrix resin and the color powder additives related to the preparation of the color masterbatch evenly, and granulate them into modified masterbatch through a twin-screw granulation device. According to the addition ratio of 5%, it is used in the production of PP-R pipes, which can not only dye PP-R but also toughen PP-R.

[0036] The formula of the PP-R green toughening color masterbatch is as follows:

[0037] Example 2 The formula of the PP-R green toughening color masterbatch is as follows:

[0038] S1. Pre-dry and dry the materials. S2. Feed the material. Continuously and stably add the toughening matrix resin into the screw through the main feeding section of the twin-screw extruder 1. The screw groove of this section of the screw is deeper to ensure that the material can smoothly enter the equipment and provide a stable material supply for subsequent processing. The temperature range of the feeding section is 140°C. S3, Plasticization: The toughened matrix resin undergoes heating and shearing in the plasticization section of the twin-screw extruder 1 and gradually melts. At the same time, it is preliminarily mixed with the added antioxidant 1010 and antioxidant 168, laying the foundation for further uniform mixing and dispersion. The temperature of the plasticization section is 170°C; S4, Mixing and Dispersion: The pigment is fully mixed and dispersed with the plasticized material in the mixing section of the twin-screw extruder 1. Shortly after the addition of the colorant, polyethylene wax and EBS are also added in the mixing section. The structural design of the mixing section usually has a strong shearing and kneading effect in this section, enabling the pigment to be evenly distributed in the resin matrix, achieving good coloring and functional additive effects. The temperature of the mixing section is 180°C; S5, Homogenization: Subsequently, zinc stearate is added to the material in the homogenization section of the twin-screw extruder 1 and fully mixed and dispersed. The temperature of the homogenization section is 170°C; S6, Exhaust: Since the material contains moisture, air, or low-molecular volatile substances generated during the processing, and zinc stearate is a substance with a certain hygroscopicity, in the exhaust section of the twin-screw extruder 1, the size of the exhaust port is adjusted according to requirements to fully discharge these substances to improve the product quality; S7, Compression: After the previous homogenization and exhaust, the material is further compressed in the compression section, making the material more dense and preparing for subsequent pelletizing. The screw groove of the screw in this section gradually becomes shallower, exerting a compression effect on the material and improving the density and uniformity of the material; S8, Molding: It is extruded through the die head of the twin-screw extruder 1, then cooled and formed by pulling with water, and then cut to form the toughened color masterbatch.

[0039] The prepared modified masterbatch is used in the production of PP-R pipes at an addition ratio of 2%.

[0040] Example 3

[0041] The formula of the PP-R green toughened color masterbatch is as follows:

[0042] S1, Pre-drying: The material is dried; S2, Feeding: The toughened matrix resin is continuously and stably added to the screw through the main feeding section of the twin-screw extruder 1. The screw groove of the screw in this section is deeper to ensure that the material can smoothly enter the equipment and provide a stable material supply for subsequent processing. The temperature range of the feeding section is 160°C; S3, Plasticization: The toughened matrix resin undergoes heating and shearing in the plasticization section of the twin-screw extruder 1 and gradually melts. At the same time, it is preliminarily mixed with the added antioxidant 1010 and antioxidant 168, laying the foundation for further uniform mixing and dispersion. The temperature of the plasticization section is 200°C; S4. Mixing and Dispersing: The pigments are thoroughly mixed and dispersed with the plasticized materials in the mixing section of the twin-screw extruder 1. Shortly after the addition of the colorant, polyethylene wax and EBS are also added in the mixing section. The structural design of the mixing section usually has strong shearing and kneading effects in this section, enabling the pigments to be evenly distributed in the resin matrix, achieving good coloring and functional addition effects. The temperature of the mixing section is 220°C. S5. Homogenizing: Then, zinc stearate is added to the materials in the homogenizing section of the twin-screw extruder 1 for thorough mixing and dispersion. The temperature of the homogenizing section is 200°C. S6. Exhausting: Since the materials contain moisture, air, or low-molecular volatile substances generated during the processing, and zinc stearate has a certain hygroscopic property, at the exhaust section of the twin-screw extruder 1, the size of the exhaust port is adjusted according to requirements to fully discharge these substances to improve the product quality. S7. Compressing: After the previous homogenizing and exhausting, the materials are further compressed in the compression section, making the materials more dense, preparing for the subsequent pelletizing and forming. The screw grooves of the screw in this section gradually become shallower, exerting a compression effect on the materials, improving the density and uniformity of the materials. S8. Forming: It is extruded through the die head of the twin-screw extruder 1, then formed by water cooling and stretching, and then cut to form the toughened color masterbatch.

[0043] The prepared modified masterbatch is used in the production of PP-R pipes at an addition ratio of 8%.

[0044] Example 4

[0045] The formula of the PP-R white toughened color masterbatch is as follows:

[0046] Example 5 The formula of the PP-R white toughened color masterbatch is as follows:

[0047] Example 6 The formula of the PP-R white toughened color masterbatch is as follows:

[0048] Performance Testing 1. Low-temperature Physical Impact Resistance Performance Testing Low-temperature Falling Weight Impact Test Testing Method: GB / T 14152 "Test Method for Resistance of Thermoplastic Plastics Pipes to External Impact - Clockwise Rotation Method" Testing Conditions: After the pipes are immersed in an ice-water mixture at 0°C for 30 minutes, the falling weight impact test is carried out.

[0049] Test data: The above toughened masterbatch and ordinary toughened masterbatch were extruded to prepare PP-R pipes, and then the low-temperature falling weight test was carried out.

[0050]

[0051] The results are shown in the following table

[0052] The results show that the PP-R pipes made with the modified masterbatch of this case have better physical impact resistance at low temperatures.

[0053] 2. Long-term hydrostatic performance experiment GB / T 6111 "Test Method for Resistance to Internal Pressure of Thermoplastic Pipes for Fluid Transportation" Test conditions: In accordance with the requirements of GB / T 18742 "Polypropylene Pipe Systems for Cold and Hot Water" Test data: The toughened masterbatch and PP-R were prepared into PP-R pipes with a specification of D25X4.2, and then the long-term hydrostatic performance test was carried out. The test results are as follows:

[0054] As Figures 13 - 17 shown, the long-term hydrostatic performance of the PP-R pipes meets the relevant national standard requirements.

Claims

1. A preparation method of a toughened color masterbatch for PP-R pipes, characterized in that, It includes the following steps: S1. Pre-drying: drying the materials; S2. Feeding: continuously and stably feeding the toughened matrix resin into the screw through the main feeding section of the twin-screw extruder (1), and the temperature range of the feeding section is 140 - 160 °C; S3. Plasticizing: the toughened matrix resin undergoes heating and shearing in the plasticizing section of the twin-screw extruder (1), gradually melts, and is preliminarily mixed with the added antioxidant 1010 and antioxidant 168 at the same time. The temperature of the plasticizing section is 170 - 200 °C; S4. Mixing and dispersing: the pigment is fully mixed and dispersed with the plasticized materials in the mixing section of the twin-screw extruder (1). Soon after the colorant is added, polyethylene wax and EBS are also added in the mixing section at the same time, so that the pigment can be evenly distributed in the resin matrix. The temperature of the mixing section is 180 - 220 °C; S5. Homogenizing: then zinc stearate is added to the materials in the homogenizing section of the twin-screw extruder (1) and fully mixed and dispersed. The temperature of the homogenizing section is 170 - 200 °C; S6. Exhausting: Since the materials contain moisture, air or low-molecular volatile substances generated during the processing, and at the same time zinc stearate is a substance with certain hygroscopicity, at the exhaust section of the twin-screw extruder (1), adjust the size of the exhaust port according to the requirements to fully discharge these substances to improve the product quality; S7. Compressing: After the previous homogenizing and exhausting, the materials are further compressed in the compression section to improve the density and uniformity of the materials; S8. Forming: extruding through the die head of the twin-screw extruder (1), then cooling and drawing into strips for forming, and then cutting to form the toughened masterbatch.

2. The preparation method of a toughened color masterbatch special for PP-R pipes according to claim 1, characterized in that, The twin-screw extruder (1) includes a heating barrel (2). The heating barrel (2) is provided with a main feeding section (21), a plasticizing section (22), a mixing section (23), and a homogenizing section (24) from left to right. The main feeding section (21), the plasticizing section (22), the mixing section (23), and the homogenizing section (24) are all provided with feeding ports (210). The feeding ports (210) are all provided with uniform feeding mechanisms (3). An exhaust port (25) is provided on the barrel wall of the heating barrel (2) located at the homogenizing section (24). An on-line stepless adjustable exhaust port mechanism (4) is provided on the exhaust port (25). A sensor for monitoring the volatile content is provided near the exhaust port (25). A vacuum exhaust system is connected to the exhaust port (25).

3. The preparation method of a toughened color masterbatch specifically for PP-R pipes according to claim 2, wherein The online stepless adjustable exhaust port mechanism (6) includes a fixed disk (61), a sliding adjustment piece (62), and a rotating moving disk (63). The fixed disk (61) is fixedly connected to the exhaust port (25). The rotating moving disk (63) is arranged above the fixed disk (61) and inside the rotating moving disk (63). The sliding adjustment piece (62) is arranged between the fixed disk (61) and the rotating moving disk (63). An air outlet (64) is provided in the middle of both the fixed disk (61) and the rotating moving disk (63). A plurality of the sliding adjustment pieces (62) are slidably arranged on the rotating moving disk (63). After the plurality of the sliding adjustment pieces (62) are spliced with each other, an adjustment port (65) is formed at the tail end. The adjustment port (65) corresponds to the air outlet (64). A rotating gear (66) is provided on the back of the rotating moving disk (63). The rotating gear (66) meshes with a driving gear (67). The driving gear (67) is fixedly connected to a first rotating motor (68).

4. The preparation method of a toughened color masterbatch special for PP-R pipes according to claim 3, characterized in that A plurality of guiding through grooves (611) are provided on the fixed disk (61). A guiding annular groove (631) is provided on the rotating moving disk (63). A guiding column (621) that cooperates with the guiding through groove (611) is provided at the bottom of the sliding adjustment piece (62). A guiding block (622) that cooperates with the guiding annular groove (631) is provided at the top of the sliding adjustment piece (62).

5. The preparation method of a toughening color masterbatch special for PP-R pipes according to claim 4, characterized in that, The uniform feeding mechanism (3) includes a storage tank (31), a stirring disk (32) with a heating wire (321) inside, a spiral conveying rod (33), and a discharge pipe (34). The discharge pipe (34) is arranged on the side wall of the storage tank (31) and is in communication with the inside of the storage tank (31). The spiral conveying rod (33) is rotatably arranged at the inner bottom of the storage tank (31) by a motor. One end of the spiral conveying rod (33) extends outside the storage tank (31), and the other end extends into the discharge pipe (34). Teeth are provided on the outer ring of the stirring disk (32), and the teeth mesh with the spiral conveying rod (33). The stirring disk (32) is rotatably arranged on the side wall of the storage tank (31). A blanking pipe (35) is provided at the end of the discharge pipe (34).

6. The preparation method of a toughening color masterbatch dedicated to PP-R pipes according to claim 5, characterized in that Stirring rods (323) are provided on both side walls of the stirring disk (32). A plurality of the stirring rods (323) are arrayed on the stirring disk (32). A guiding through hole (322) is provided in the middle of the stirring disk (32).

7. The preparation method of a toughening color masterbatch special for PP-R pipes according to claim 6, characterized in that An exhaust mechanism (5) is provided at the top of the storage tank (31). The exhaust mechanism (5) includes an exhaust cavity (51) that is in communication with the top of the storage tank (31). An inclined filter plate (52) is provided in the exhaust cavity (51). An exhaust hole (53) is provided at the lower right of the exhaust cavity (51).

8. The preparation method of a toughened color masterbatch special for PP-R pipes according to claim 7, characterized in that, The inclined filter plate (52) includes two filter plates (521). A number of bouncing beads (522) are provided between the two filter plates (521). Adjacent bouncing beads (522) are separated by a partition plate (523). A knocking mechanism (7) is provided on the right side of the inclined filter plate (52). The knocking mechanism (7) includes a second rotating motor (71), a rotating plate (72), a connecting rod (73), a piston (74), a fixed cylinder (75) with a hollow interior, a knocking member (76), and a connecting rod (77). The rotating plate (72) is arranged at the output end of the second rotating motor (71). An eccentric hole (721) is provided on the rotating plate (72). One end of the connecting rod (73) is connected to the eccentric hole (721), and the other end is rotatably connected to the piston (74). The piston (74) slides in the fixed cylinder (75), and the fixed cylinder (75) is fixed to the inner wall of the exhaust cavity (51). The connecting rod (67) is fixed to the end of the piston (74). The knocking member (76) is fixed to the end of the connecting rod (77).

9. A toughened color masterbatch prepared by the preparation method of the toughened color masterbatch special for PP-R pipes according to any one of claims 1-8, characterized in that, It includes a toughened matrix resin with a weight ratio of 40 - 70%, 20 - 45% pigment, 5 - 7% polyethylene wax, 1 - 3% EBS, 0.5 - 1.5% zinc stearate, 0.3 - 0.7% antioxidant 1010, and 0.1 - 0.5% antioxidant 168.

10. A toughening color masterbatch for PP-R pipes according to claim 9, characterized in that, It includes a toughened matrix resin with a weight ratio of 60.00% - 70.00%, 1.00% - 2.00% green powder, 1.50% - 2.50% yellow powder, 20.00% - 25.00% titanium dioxide, 0.10% - 0.30% carbon black powder, 5.00% - 7.00% polyethylene wax, 1.50% - 2.50% EBS, 0.50% - 1.50% zinc stearate, 0.30% - 0.50% antioxidant 1010, and 0.10% - 0.30% antioxidant 168.

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