Large-diameter hdpe pipe and method for producing the same
By using a specific combination of PE100 grade resin and inorganic modified reinforcing and toughening agents in large-diameter HDPE pipes, the problems of uneven wall thickness and poor pressure bearing capacity are solved, the toughness and structural stability of the pipes are improved, and the requirements of engineering applications are met.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG HUSHUNTONG PLASTIC ENG TECH CO LTD
- Filing Date
- 2026-03-24
- Publication Date
- 2026-06-05
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This application relates to the field of plastic products, and in particular to a large-diameter HDPE pipe and its preparation method. Background Technology
[0002] High-density polyethylene (HDPE) pipes have significant advantages such as light weight, corrosion resistance, resistance to environmental stress cracking, reliable connections, and long service life, and have been widely used in the drainage field. With the expansion of engineering construction scale and the increase in drainage demand, the application scenarios of large-diameter HDPE drainage pipes are becoming increasingly widespread, playing an important role in urban drainage network renovation, municipal drainage, and large-scale park drainage projects.
[0003] Currently, large-diameter HDPE drainage pipes are mostly manufactured using extrusion molding, which easily leads to numerous technical challenges during production. Uneven wall thickness is a particularly prominent issue, specifically manifested as a thinner upper section and a thicker lower section. This problem not only affects the dimensional accuracy and material utilization of the pipes but also causes localized stress concentration, thereby reducing their pressure-bearing capacity and structural stability, making it difficult to meet the long-term safe operation requirements of drainage projects.
[0004] To improve the pressure resistance and mechanical properties of large-diameter HDPE drainage pipes, the industry often uses inorganic fillers to modify HDPE resin. However, inorganic fillers have poor compatibility with the HDPE matrix, and simple physical blending easily leads to problems such as filler agglomeration and weak interfacial bonding. This not only fails to effectively improve pipe performance but may also reduce its toughness and processing stability. Although existing modification technologies attempt to improve compatibility through coupling agents, the modification effect is limited, and it is still difficult to solve the core problems of uneven wall thickness, insufficient pressure resistance, and insufficient toughness during the extrusion process of large-diameter drainage pipes. Therefore, how to solve the problems of uneven wall thickness, poor pressure bearing capacity, and insufficient toughness in the production process of large-diameter HDPE drainage pipes is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0005] In order to improve the problems of uneven wall thickness, poor pressure bearing capacity and low toughness of large-diameter HDPE drainage pipes in related technologies, this application provides a large-diameter HDPE pipe and its preparation method.
[0006] In a first aspect, this application provides a large-diameter HDPE pipe, wherein, by weight, the raw materials for preparing the large-diameter HDPE pipe include 80-85 parts HDPE resin, 3-5 parts organic toughening agent, 8-10 parts inorganic modified reinforcing toughening agent, 0.1-0.3 parts antioxidant, and 0.3-0.4 parts lubricant; wherein, the HDPE resin is a bimodal PE100 grade HDPE resin with a melt flow rate of 0.1-0.5 g / 10 min at 190℃ and a weight ratio of 5 kg; the raw materials for the inorganic modified reinforcing toughening agent include an aminosilane coupling agent, inorganic filler, maleic anhydride grafted polyethylene, and long-chain alkyl primary amine in a weight ratio of (0.2-0.3):100:(8-10):(3-5).
[0007] To address the issues of uneven wall thickness (thinner upper section and thicker lower section) and poor pressure resistance in large-diameter HDPE pipes during production, this application uses bimodal PE100 grade HDPE resin with a melt flow rate of 0.1-0.5 g / min as the main material. This prevents sagging during the processing of large-diameter HDPE pipes. It also incorporates an aminosilane coupling agent reacting with inorganic fillers to obtain aminated inorganic fillers, followed by the reaction of the amino groups in the aminated inorganic fillers with maleic anhydride-grafted anhydride groups in polyethylene to obtain pre-... The modified reinforcing and toughening agent, and finally the inorganic modified reinforcing and toughening agent obtained by reacting the residual anhydride groups in the pre-modified reinforcing and toughening agent with the amino groups in the long-chain alkyl primary amine, have better dispersibility and compatibility in specific HDPE resins compared with existing silane coupling agent modified inorganic fillers. In addition, when combined with appropriate amounts of organic toughening agents, antioxidants, and lubricants, it can improve the pressure-bearing capacity of large-diameter pipes while improving their toughness, which is beneficial to obtaining large-diameter HDPE pipes with uniform wall thickness, good pressure-bearing capacity, and good toughness.
[0008] In some preferred embodiments, the HDPE resin is a bimodal PE100 grade HDPE resin with a melt flow rate of 0.1-0.3 g / 10 min at 190°C and a density of 5 kg.
[0009] In some specific embodiments, the inorganic filler is a composition of talc powder and nano-calcium carbonate in a weight ratio of (2-3):1.
[0010] In this application, the inorganic filler is a composition of talc powder and nano-calcium carbonate in a weight ratio of (2-3):1, which can leverage the advantages of both materials. Talc powder has a good lamellar structure, which can form a certain skeleton in the pipe, improving the rigidity and dimensional stability of the pipe; nano-calcium carbonate particles are small, have a larger specific surface area, and more stress concentration points per unit volume, which can generate more micro-yield zones and improve the toughness of the material.
[0011] The talc powder has a mesh size range of 1250-2000 mesh, and the nano-calcium carbonate has a particle size range of 20-50 nm.
[0012] In some specific embodiments, the maleic anhydride grafting rate in the maleic anhydride-grafted polyethylene is 0.8-1.2%.
[0013] In some specific embodiments, the long-chain alkyl primary amine is at least one of C14-C18 alkyl primary amines.
[0014] In this application, at least one of C14-C18 alkyl primary amines was chosen as the long-chain alkyl primary amine because these long-chain alkyl primary amines have suitable carbon chain lengths. Their longer carbon chains can better interact with HDPE resin and other raw materials, further improving the compatibility and dispersibility of the inorganic modified reinforcing and toughening agent in the HDPE resin system. Furthermore, incorporating longer carbon chains into maleic anhydride-grafted polyethylene also facilitates the formation of a comb-like structure by the inorganic modified reinforcing and toughening agent, thereby synergistically improving the dispersibility of the inorganic modified reinforcing and toughening agent in the HDPE resin system.
[0015] In some specific embodiments, the preparation method of the inorganic modified reinforcing and toughening agent includes the following steps: The inorganic filler was added to an ethanol solution, and then an aminosilane coupling agent was added. The mixture was refluxed and stirred at 60-80°C for 3-4 hours. The solid was then separated, washed, and dried to obtain the aminated inorganic filler. The maleic anhydride-grafted polyethylene was added to the first organic solvent and stirred until dissolved. Then it was mixed with the aminated inorganic filler and refluxed at 120-130°C for 3-4 hours. After the reaction was completed, the mixture was cooled, the solid was separated, washed, and the pre-modified reinforcing and toughening agent was obtained. Long-chain alkyl primary amines are added to a second organic solvent and stirred until dissolved. Then, they are mixed evenly with the pre-modified reinforcing and toughening agent and refluxed at 120-130°C for 1-2 hours. The solid is then separated, washed, and dried to obtain the inorganic modified reinforcing and toughening agent.
[0016] In this application, an aminosilane coupling agent is first reacted with an inorganic filler to obtain an aminated inorganic filler. Then, the amino groups in the aminated inorganic filler react with the anhydride groups in maleic anhydride-grafted polyethylene to obtain a pre-modified reinforcing and toughening agent. Finally, the residual anhydride groups in the pre-modified reinforcing and toughening agent react with the amino groups in long-chain alkyl primary amines to obtain an inorganic modified reinforcing and toughening agent. This inorganic modified reinforcing and toughening agent can be uniformly dispersed in bimodal PE100 grade HDPE resin with a melt flow rate of 0.1-0.5 g / min, and simultaneously plays a reinforcing and toughening role.
[0017] In some specific embodiments, the organic toughening agent is a linear styrene-butadiene thermoplastic elastomer, wherein the mass percentage of styrene in the styrene-butadiene thermoplastic elastomer is 20-30%.
[0018] In some preferred embodiments, the lubricant is a composition of polyethylene wax and zinc stearate in a weight ratio of (2-3):1.
[0019] In some preferred embodiments, the antioxidant is a composition of antioxidant 1010 and antioxidant 168 in a weight ratio of (1-1.5):1.
[0020] In some specific embodiments, the nominal outer diameter of the large-diameter HDPE pipe is 1000mm-2000mm.
[0021] Secondly, this application provides a method for preparing the above-mentioned large-diameter HDPE pipe, comprising the following steps: HDPE resin, organic toughening agent, inorganic modified reinforcing toughening agent, antioxidant, and lubricant are uniformly mixed and fed into a screw extruder. The mixture is then extruded through a die to produce the desired large-diameter HDPE pipe.
[0022] In some specific implementations, the screw extruder body temperature is 180-190℃, and the die head temperature is 185-190℃.
[0023] In summary, this application includes at least the following beneficial technical effects: (1) This application uses bimodal PE100 grade HDPE resin with a melt flow rate of 0.1-0.5 g / min as the main material, which can prevent the sagging phenomenon during the processing of large-diameter HDPE pipes. It is combined with an inorganic modified toughening agent obtained by reacting an aminosilane coupling agent with an inorganic filler, then obtaining a pre-modified reinforcing toughening agent by reacting the amino groups in the amino-silane coupling agent with the anhydride groups in the maleic anhydride grafted polyethylene, and finally obtaining an inorganic modified reinforcing toughening agent obtained by reacting the residual anhydride groups in the pre-modified reinforcing toughening agent with the amino groups in the long-chain alkyl primary amine. Compared with the existing silane coupling agent modified inorganic filler, the inorganic modified reinforcing toughening agent of this application has better dispersibility and compatibility in specific HDPE resins. In addition, it can work synergistically with appropriate amounts of organic toughening agents, antioxidants, and lubricants to improve the pressure bearing capacity of large-diameter pipes while improving the toughness of large-diameter pipes. This is conducive to obtaining large-diameter HDPE pipes with uniform wall thickness, good pressure bearing capacity, and good toughness.
[0024] (2) In this application, the inorganic filler is a combination of talc powder and nano-calcium carbonate in a weight ratio of (2-3):1, which can give full play to the advantages of the two materials. Talc powder has a good lamellar structure, which can form a certain skeleton in the pipe and improve the rigidity and dimensional stability of the pipe; nano-calcium carbonate particles are small, the larger the specific surface area, the more stress concentration points per unit volume, and can generate more micro-yield zones, which can improve the toughness of the material.
[0025] (3) In this application, at least one of C14-C18 alkyl primary amines was selected as a long-chain alkyl primary amine because such long-chain alkyl primary amines have suitable carbon chain lengths. Their longer carbon chains can better interact with HDPE resin and other raw materials, further improving the compatibility and dispersibility of the inorganic modified reinforcing and toughening agent in the HDPE resin system. In addition, the incorporation of longer carbon chains into maleic anhydride-grafted polyethylene is also beneficial for the inorganic modified reinforcing and toughening agent to form a comb-like structure, so as to synergistically improve the dispersibility of the inorganic modified reinforcing and toughening agent in the HDPE resin system. Detailed Implementation
[0026] The following section provides further explanation of this application in conjunction with specific experiments.
[0027] Preparation Example
Preparation Example 1
[0028] The preparation method of the inorganic modified reinforcing and toughening agent in this preparation example is as follows: S1. Add the inorganic filler to a 95% (v / v) aqueous ethanol solution, then add the aminosilane coupling agent KH550, reflux and stir at 60°C for 4 hours, then separate the solid, wash and dry to obtain the aminated inorganic filler. S2. Maleic anhydride-grafted polyethylene is added to the first organic solvent and stirred until dissolved. Then, it is added to the above-mentioned aminated inorganic filler and mixed evenly. The mixture is refluxed at 120°C for 4 hours. After the reaction is completed, the mixture is cooled, the solid is separated, washed, and the pre-modified reinforcing and toughening agent is obtained. S3. Add octadecyl primary amine to the second organic solvent, stir and dissolve evenly, then add it to the above pre-modified reinforcing and toughening agent and mix evenly. Reflux at 120°C for 2 hours, then separate the solid, wash and dry it to obtain the inorganic modified reinforcing and toughening agent.
[0029]
Preparation Example 2
[0030] The preparation method of the inorganic modified reinforcing and toughening agent in this preparation example is as follows: S1. Add the inorganic filler to a 95% (v / v) aqueous ethanol solution, then add the aminosilane coupling agent KH550, reflux and stir at 80°C for 3 hours, then separate the solid, wash and dry to obtain the aminated inorganic filler. S2. Maleic anhydride-grafted polyethylene is added to the first organic solvent and stirred until dissolved. Then, it is added to the above-mentioned aminated inorganic filler and mixed evenly. The mixture is refluxed at 130°C for 3 hours. After the reaction is completed, the mixture is cooled, the solid is separated, washed, and the pre-modified reinforcing and toughening agent is obtained. S3. Add octadecyl primary amine to the second organic solvent, stir and dissolve evenly, then add it to the above pre-modified reinforcing and toughening agent and mix evenly. Reflux at 130°C for 1 hour, then separate the solid, wash and dry it to obtain the inorganic modified reinforcing and toughening agent.
[0031]
Preparation Example 3
[0032]
Preparation Example 4
[0033] The preparation method of the inorganic modified reinforcing and toughening agent in this preparation example is as follows: S1. Add the inorganic filler to a 95% (v / v) aqueous ethanol solution, then add the aminosilane coupling agent KH550, reflux and stir at 60°C for 4 hours, then separate the solid, wash and dry to obtain the aminated inorganic filler. S2. Add octadecanoic acid to the second organic solvent, stir and dissolve evenly, then add it to the above-mentioned aminated inorganic filler and mix evenly. Reflux at 120°C for 2 hours, then separate the solid, wash and dry it to obtain the inorganic modified reinforcing and toughening agent.
[0034]
Preparation Example 5
[0035]
Example 1
[0036] In this embodiment, the preparation method of large-diameter HDPE pipe is as follows: HDPE resin, organic toughening agent, inorganic modified reinforcing toughening agent, antioxidant, and lubricant are mixed evenly according to the formula and output to a single screw extruder. After extrusion through a die and cooling, the required large-diameter HDPE pipe is obtained. The body temperature of the single screw extruder is 185-190℃, and the die head temperature is 190℃.
[0037]
Example 2
[0038] In this embodiment, the preparation method of large-diameter HDPE pipe is as follows: HDPE resin, organic toughening agent, inorganic modified reinforcing toughening agent, antioxidant, and lubricant are mixed evenly according to the formula and output to a single-screw extruder. After extrusion through a die and cooling, the required large-diameter HDPE pipe is obtained. The body temperature of the single-screw extruder is 180-185℃, and the die head temperature is 185℃.
[0039] Comparative Example Comparative Example 1 A large-diameter HDPE pipe differs from [Example 1] in that the inorganic modified reinforcing and toughening agent used is the inorganic modified reinforcing and toughening agent prepared in [Preparation Example 3].
[0040] Comparative Example 2 A large-diameter HDPE pipe differs from [Example 1] in that the inorganic modified reinforcing and toughening agent used is the inorganic modified reinforcing and toughening agent prepared in [Preparation Example 4].
[0041] Comparative Example 3 A large-diameter HDPE pipe differs from [Example 1] in that the inorganic modified reinforcing and toughening agent used is the inorganic modified reinforcing and toughening agent prepared in [Preparation Example 5].
[0042] Comparative Example 4 A large-diameter HDPE pipe differs from [Example 1] in that the raw material ratios of the components are different. In this comparative example, the raw materials for preparing the large-diameter HDPE pipe are as follows: 90 kg HDPE resin, 8 kg styrene-butadiene thermoplastic elastomer, 5 kg inorganic modified reinforcing and toughening agent obtained in [Preparation Example 1], 0.1 kg antioxidant, and 0.4 kg lubricant.
[0043] Performance testing Coefficient of variation for wall thickness uniformity: Refer to section 5.2.3 of GB / T 8806-2008 to test the average wall thickness X, then calculate the standard deviation S of the wall thickness, and calculate the coefficient of variation for uniformity according to the formula CV=(S / X)*100%. The requirement is that the coefficient of variation for wall thickness uniformity is ≤5%.
[0044] Ring stiffness: Tested in accordance with GB / T 9647-2015, with a sample length of 450 mm and a loading speed of 20 mm / min.
[0045] Elongation at break: Tested in accordance with GB / T 8804.1-2020. The specimen is a dumbbell-shaped specimen with a length of 50 mm. The conditioning conditions are 0℃ air bath, conditioning time is 240 min, and tensile speed is 50 mm / min.
[0046] Table 1
[0047] Based on the test data in Table 1, it can be seen that the large-diameter HDPE pipes produced in Examples 1-2 of this application meet the requirements of wall thickness uniformity variation coefficient < 5% and ring stiffness > 40 KN / m. 2The requirement of elongation at break >700% was also met. Furthermore, compared to Example 1, the inorganic modified reinforcing and toughening agent used in Comparative Example 1 for the large-diameter HDPE pipe omitted the modification step of octadecylamine; the inorganic modified reinforcing and toughening agent used in Comparative Example 2 for the large-diameter HDPE pipe omitted the modification step of maleic anhydride-grafted polyethylene, and octadecanoic acid was used instead of octadecylamine to react with the aminated inorganic filler; and the weight ratio between the main components in the inorganic modified reinforcing and toughening agent used in Comparative Example 3 for the large-diameter HDPE pipe was outside the scope of this application. As a result, the ring stiffness and toughness of the large-diameter HDPE pipes in Comparative Examples 1-3 were reduced, indicating that the specific inorganic modified reinforcing and toughening agent of this application has excellent dispersibility and compatibility in specific HDPE resins, which is beneficial for preparing pipes that simultaneously meet the requirements of wall thickness uniformity variation coefficient <5% and ring stiffness >40KN / m. 2 Large-diameter HDPE pipes with an elongation at break >700%. In Comparative Example 4, the component ratios of the large-diameter HDPE pipes are outside the scope of this application. As a result, the ring stiffness and toughness of the large-diameter HDPE pipes in Comparative Example 4 are also reduced, indicating that the component ratios are also within the scope of this application, simultaneously satisfying the requirements of wall thickness uniformity variation coefficient <5% and ring stiffness >40KN / m. 2 The key to large-diameter HDPE pipes with an elongation at break of >700%.
[0048] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this specific embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A large-diameter HDPE pipe, characterized in that, The raw materials for preparing the large-diameter HDPE pipe, by weight, include 80-85 parts HDPE resin, 3-5 parts organic toughening agent, 8-10 parts inorganic modified reinforcing toughening agent, 0.1-0.3 parts antioxidant, and 0.3-0.4 parts lubricant; wherein, the HDPE resin is a bimodal PE100 grade HDPE resin with a melt flow rate of 0.1-0.5 g / 10 min at 190℃ and a weight ratio of 5 kg; the raw materials for the inorganic modified reinforcing toughening agent include an aminosilane coupling agent, inorganic filler, maleic anhydride grafted polyethylene, and long-chain alkyl primary amine in a weight ratio of (0.2-0.3):100:(8-10):(3-5).
2. The large-diameter HDPE pipe according to claim 1, characterized in that, The inorganic filler is a composition of talc powder and nano-calcium carbonate in a weight ratio of (2-3):
1.
3. The large-diameter HDPE pipe according to claim 1, characterized in that, In the maleic anhydride-grafted polyethylene, the maleic anhydride grafting rate is 0.8-1.2%.
4. The large-diameter HDPE pipe according to claim 1, characterized in that, The long-chain alkyl primary amine is at least one of C14-C18 alkyl primary amines.
5. A large-diameter HDPE pipe according to any one of claims 1-4, characterized in that, The preparation method of the inorganic modified reinforcing and toughening agent includes the following steps: The inorganic filler was added to an ethanol solution, and then an aminosilane coupling agent was added. The mixture was refluxed and stirred at 60-80°C for 3-4 hours. The solid was then separated, washed, and dried to obtain the aminated inorganic filler. The maleic anhydride-grafted polyethylene was added to the first organic solvent and stirred until dissolved. Then it was mixed with the aminated inorganic filler and refluxed at 120-130°C for 3-4 hours. After the reaction was completed, the mixture was cooled, the solid was separated, washed, and the pre-modified reinforcing and toughening agent was obtained. Long-chain alkyl primary amines are added to a second organic solvent and stirred until dissolved. Then, they are mixed evenly with the pre-modified reinforcing and toughening agent and refluxed at 120-130°C for 1-2 hours. The solid is then separated, washed, and dried to obtain the inorganic modified reinforcing and toughening agent.
6. A large-diameter HDPE pipe according to claim 1, characterized in that, The organic toughening agent is a linear styrene-butadiene thermoplastic elastomer, wherein the mass percentage of styrene in the styrene-butadiene thermoplastic elastomer is 20-30%.
7. A large-diameter HDPE pipe according to claim 1, characterized in that, The lubricant is a composition of polyethylene wax and zinc stearate in a weight ratio of (2-3):
1.
8. A large-diameter HDPE pipe according to claim 1, characterized in that, The antioxidant is a composition of antioxidant 1010 and antioxidant 168 in a weight ratio of (1-1.5):
1.
9. A large-diameter HDPE pipe according to claim 1, characterized in that: The nominal outer diameter of the large-diameter HDPE pipe is 1000mm-2000mm.
10. A method for preparing a large-diameter HDPE pipe, used to prepare a large-diameter HDPE pipe as described in any one of claims 1-9, characterized in that, Includes the following steps: HDPE resin, organic toughening agent, inorganic modified reinforcing toughening agent, antioxidant, and lubricant are uniformly mixed and fed into a screw extruder. The mixture is then extruded through a die to produce the desired large-diameter HDPE pipe.