A weather-resistant and scale-resistant PE drainage pipe and its preparation method

Abstract

The present invention discloses a weather-resistant and scale-resistant PE drainage pipe and a preparation method thereof, relating to the field of pipe materials. Among them, the weather-resistant and scale-resistant PE drainage pipe comprises a scale-resistant PE inner layer and a weather-resistant PE outer layer. The preparation raw materials of the scale-resistant PE inner layer include 100 parts by weight of a first HDPE resin, 4.5 - 5.5 parts by weight of modified zinc oxide whiskers, 1 - 2 parts by weight of polyolefin wax, and 0.005 - 0.01 parts by weight of a first initiator. The modified zinc oxide whiskers are obtained by modifying zinc oxide whiskers with at least a vinyl / allyl silane coupling agent. Through the synergistic cooperation of the modified zinc oxide whiskers and polyethylene wax, the present application can obtain a PE drainage pipe with excellent scale-resistant performance.

Description

Technical Field

[0001] The present application relates to the field of pipe materials, and in particular to a weather-resistant and scale-resistant PE drainage pipe and a preparation method thereof. Background Art

[0002] Due to its good chemical stability, corrosion resistance, and convenient construction, PE drainage pipes are widely used in construction, municipal engineering and other projects. However, there are still some problems to be solved urgently in the actual use of existing PE drainage pipes.

[0003] For example: there are often various microorganisms and impurities in drainage pipes. The growth of microorganisms and the attachment of impurities are likely to form dirt, which will not only affect the drainage efficiency of drainage pipes, but also may cause pipe blockage and increase maintenance costs. Although zinc oxide whiskers have antibacterial effects and can inhibit the growth of microorganisms, theoretically, they can improve the scale resistance of PE drainage pipes. However, there are problems with poor interfacial compatibility between zinc oxide whiskers and the resin matrix in PE resin, which will cause uneven dispersion of zinc oxide or poor interfacial bonding strength, greatly reducing the effect of improving the antibacterial and scale resistance ability. Summary of the Invention

[0004] In order to improve the scale resistance of PE drainage pipes, the present application provides a weather-resistant and scale-resistant PE drainage pipe and a preparation method thereof.

[0005] In the first aspect, a weather-resistant and scale-resistant PE drainage pipe provided by the present application adopts the following technical solution:

[0006] A weather-resistant and scale-resistant PE drainage pipe includes a scale-resistant PE inner layer and a weather-resistant PE outer layer. The preparation raw materials of the scale-resistant PE inner layer include 100 parts by weight of a first HDPE resin, 4.5 - 5.5 parts by weight of modified zinc oxide whiskers, 1 - 2 parts by weight of polyolefin wax, and 0.005 - 0.01 parts by weight of a first initiator. The modified zinc oxide whiskers are obtained by modifying zinc oxide whiskers with at least vinyl / allyl silane coupling agents; the preparation raw materials of the weather-resistant PE outer layer include 100 parts by weight of a second HDPE resin, 0.002 - 0.004 parts by weight of a PE-carbon black masterbatch, 6.5 - 7.5 parts by weight of acrylate-capped silicone oil, and 0.01 - 0.015 parts by weight of a second initiator.

[0007] Zinc oxide whiskers have antibacterial effects and can inhibit the growth of microorganisms, which can improve the scale resistance of the scale-resistant PE inner layer. However, zinc oxide whiskers are prone to poor interfacial compatibility between the resin matrixes in PE resin, which is likely to cause problems such as uneven dispersion of zinc oxide or poor interfacial bonding strength.

[0008] Therefore, in the anti-scaling PE inner layer of the PE drain pipe of the present application, modified zinc oxide whiskers are used instead of zinc oxide whiskers. The modified zinc oxide whiskers are obtained by modifying zinc oxide whiskers with vinyl / allyl silane coupling agents at least. Among them, the silanol groups generated after hydrolysis of the vinyl / allyl silane coupling agent react with the hydroxyl groups on the surface of the zinc oxide whiskers to graft the vinyl / allyl silane coupling agent onto the surface of the zinc oxide whiskers. Then, the free radicals decomposed by the first initiator in a high-temperature environment initiate the cross-linking reaction between the carbon-carbon double bonds in the modified zinc oxide whiskers and the first HDPE resin to form a cross-linked network, effectively improving the interfacial bonding strength between the vinyl / allyl silane coupling agent-modified zinc oxide whiskers and the first HDPE resin, which is beneficial to obtaining a PE anti-scaling inner layer with long-term antibacterial effects. Polyolefin wax can reduce the melt viscosity of the first HDPE resin, which is beneficial to promoting the uniform dispersion of the modified zinc oxide whiskers in the melt of the first HDPE resin, improving the melt fluidity after incorporating the modified zinc oxide whiskers, and facilitating the preparation of an anti-scaling PE inner layer with a smooth inner wall and small roughness, so as to weaken the adhesion of the scale-forming substances on the anti-scaling PE inner layer and reduce the attachment of the scale-forming substances. That is, under the combined action of the antibacterial modified zinc oxide whiskers and the anti-scaling PE inner layer with a smooth inner wall in the present application, a PE drain pipe with good anti-scaling performance can be obtained.

[0009] In addition, in the weather-resistant PE outer layer of the present application, a PE-carbon black masterbatch capable of effectively absorbing ultraviolet rays is added to prevent the problem of aging of the PE drain pipe due to ultraviolet irradiation during outdoor use; acrylate-capped silicone oil and a second initiator are added, and under the initiation of the second initiator, the acrylate-capped silicone oil reacts with the second HDPE resin to cross-link, which can further improve the heat-aging resistance of the weather-resistant PE outer layer and is beneficial to obtaining a PE drain pipe with good weather resistance.

[0010] In some specific embodiments, the diameter of the modified zinc oxide whiskers is 30-40 nm, the length is 200-300 nm, and the aspect ratio is 5-10.

[0011] In some specific embodiments, the structural formula of the acrylate-capped silicone oil is as follows:

[0012] CH2=CR1COO(CH2)3SiR2R3O(SiR2R3O) n SiR2R3(CH2)3OOCCR1=CH2;

[0013] Among them, R1 is H or an alkyl group, R2 and R3 are alkyl groups or phenyl groups, and the value range of n is 40-50.

[0014] In some specific embodiments, the acrylate-capped silicone oil includes acrylate-capped silicone oil A and acrylate-capped silicone oil B, and the weight ratio of acrylate-capped silicone oil A to acrylate-capped silicone oil B is (3 - 4):1; wherein, in acrylate-capped silicone oil A, R1 is H, and R2 and R3 are methyl groups; in acrylate-capped silicone oil B, R1 is a methyl group, R2 is a methyl group, and R3 is a phenyl group.

[0015] This application preferably uses a composition of acrylate-capped silicone oil A and acrylate-capped silicone oil B as the acrylate-capped silicone oil, which can effectively improve the heat aging performance while improving the ring stiffness and low-temperature impact resistance of the PE drainage pipe, thereby obtaining a PE drainage pipe with excellent weather resistance.

[0016] In some specific embodiments, the raw materials for preparing the PE-carbon black masterbatch include 50 - 60 parts by weight of PE resin, 40 - 50 parts by weight of modified carbon black, and 0.1 - 0.2 parts by weight of silicone masterbatch; wherein, the modified carbon black is obtained by jointly modifying carbon black with a vinyl / allyl silane coupling agent and an epoxy silane coupling agent. In the raw materials for preparing the modified carbon black, the weight ratio of the vinyl / allyl silane coupling agent, the epoxy silane coupling agent to carbon black is (0.15 - 0.25):(0.15 - 0.25):1.

[0017] In some specific embodiments, the modified zinc oxide whiskers are obtained by jointly modifying zinc oxide whiskers with a vinyl / allyl silane coupling agent and an amino silane coupling agent. In the raw materials for preparing the modified zinc oxide whiskers, the weight ratio of the vinyl / allyl silane coupling agent, the amino silane coupling agent to zinc oxide whiskers is (0.3 - 0.4):(0.3 - 0.4):1.

[0018] In this application, the modified carbon black is the modified carbon black obtained by jointly modifying carbon black with a vinyl / allyl silane coupling agent and an epoxy silane coupling agent. By selecting a specific weight ratio among the vinyl / allyl silane coupling agent, the epoxy silane coupling agent and carbon black, the vinyl / allyl silane coupling agent and the epoxy silane coupling agent are simultaneously grafted onto the carbon black. The modified zinc oxide whiskers are the modified zinc oxide whiskers obtained by jointly modifying zinc oxide whiskers with a vinyl / allyl silane coupling agent and an amino silane coupling agent. By selecting a specific weight ratio among the vinyl / allyl silane coupling agent, the amino silane coupling agent and zinc oxide whiskers, the vinyl / allyl silane coupling agent and the amino silane coupling agent are simultaneously grafted onto the zinc oxide whiskers.

[0019] Among them, the vinyl / allyl silane coupling agent on the modified carbon black can crosslink with the resin of the weather-resistant PE outer layer, improving the bonding strength between the modified carbon black and the weather-resistant PE outer layer resin, which is beneficial to improving the low-temperature embrittlement and heat aging problems of the weather-resistant PE outer layer; the epoxy silane coupling agent on the modified carbon black can chemically bond with the amino silane coupling agent on the modified zinc oxide whiskers, which can enhance the bonding strength between the anti-scaling PE inner layer and the weather-resistant PE outer layer, thereby improving the low-temperature embrittlement and heat aging problems of the PE drainage pipe. The vinyl / allyl silane coupling agent on the modified zinc oxide whiskers can crosslink with the resin of the anti-scaling PE inner layer, which can improve the bonding strength between the modified zinc oxide whiskers and the anti-scaling PE inner layer resin, and is beneficial to improving the low-temperature embrittlement and heat aging problems of the anti-scaling PE inner layer. After effectively improving the low-temperature embrittlement and heat aging problems of the weather-resistant PE outer layer, the anti-scaling PE inner layer, and the bonding interface between the anti-scaling PE inner layer and the weather-resistant PE outer layer, it is beneficial to obtain a PE drainage pipe with excellent low-temperature embrittlement resistance and heat aging resistance.

[0020] In some specific embodiments, the thickness ratio of the anti-scaling PE inner layer to the weather-resistant PE outer layer is (4 - 6):1.

[0021] In some specific embodiments, the first initiator and the second initiator are respectively at least one of benzoyl peroxide and diisopropylbenzene peroxide.

[0022] In some specific embodiments, the vinyl / allyl silane coupling agent is at least one of vinyltriethoxysilane, vinyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, and γ-(methacryloyloxy)propyltriethoxysilane.

[0023] In a second aspect, a preparation method of the weather-resistant and anti-scaling PE drainage pipe provided by the present application adopts the following technical solution:

[0024] A preparation method of a weather-resistant and anti-scaling PE drainage pipe includes the following steps:

[0025] Put the preparation raw materials of the anti-scaling PE inner layer into extruder A according to the ratio, and melt and mix them evenly at 195 - 205 °C to obtain the anti-scaling PE inner layer melt;

[0026] Put the preparation raw materials of the weather-resistant PE outer layer into extruder B according to the ratio, and melt and mix them evenly at 195 - 205 °C to obtain the weather-resistant PE outer layer melt;

[0027] Distribute the anti-scaling PE inner layer melt to the inner layer of the two-layer co-extrusion die, distribute the weather-resistant PE outer layer melt to the outer layer of the two-layer co-extrusion die, and co-extrude them at 180 - 190 °C, then vacuum shape, cool, and cut to obtain the weather-resistant and anti-scaling PE drainage pipe.

[0028] In some specific embodiments, in the vacuum sizing step, the vacuum degree is controlled to be -0.02 Mpa to -0.06 Mpa.

[0029] In summary, the present application at least includes the following beneficial technical effects:

[0030] In the weather-resistant and scale-resistant PE drainage pipe of the present application, the modified zinc oxide whiskers in the scale-resistant PE inner layer are at least obtained by modifying zinc oxide whiskers with vinyl / allyl silane coupling agents, which can improve the interfacial bonding strength between the modified zinc oxide whiskers and the resin matrix, and is beneficial to obtaining a PE scale-resistant inner layer with long-term antibacterial effects. In addition, adding a certain amount of polyethylene wax can achieve uniform dispersion of the modified zinc oxide whiskers, which is beneficial to obtaining a scale-resistant PE inner layer with a smooth inner wall and small roughness, and reducing the adhesion of scale-forming substances. That is, the present application can obtain a PE drainage pipe with excellent scale resistance through the synergistic cooperation of modified zinc oxide whiskers and polyethylene wax.

[0031] In the weather-resistant PE outer layer of the present application, a PE-carbon black masterbatch capable of effectively absorbing ultraviolet rays is added to prevent the problem of aging of the PE drainage pipe due to ultraviolet irradiation during outdoor use; acrylate-capped silicone oil and a second initiator are added, and under the initiation of the second initiator, the acrylate-capped silicone oil and the second HDPE resin undergo a cross-linking reaction, which can further improve the heat aging performance of the weather-resistant PE outer layer.

[0032] Preferably, the acrylate-capped silicone oil in the present application is a composition of acrylate-capped silicone oil A and acrylate-capped silicone oil B, which can effectively improve the heat aging performance while improving the ring stiffness and low-temperature impact resistance of the PE drainage pipe, so as to obtain a PE drainage pipe with excellent weather resistance. Specific Embodiments

[0033] The following further illustrates the present application in combination with specific experiments.

[0034] Preparation Example of Modified Zinc Oxide

[0035]

Preparation Example 1-1

[0036] A kind of modified zinc oxide whiskers, and its preparation method includes the following steps:

[0037] Add 0.35 kg of vinyltriethoxysilane to 10 kg of ethanol aqueous solution, stir and dissolve evenly, then add 1 kg of zinc oxide whiskers (diameter 30-40 nm, length 200-300 nm, aspect ratio 5-10), ultrasonically disperse evenly, then heat up to 40 °C, stir and react for 2 h, and then filter to obtain the solid and dry it to obtain modified zinc oxide whiskers.

[0038]

Preparation Example 1-2

[0039] A modified zinc oxide whisker, and its preparation method comprises the following steps:

[0040] Add 0.35 kg of vinyltriethoxysilane and 0.35 kg of amino silane coupling agent KH550 into 10 kg of ethanol aqueous solution. After stirring and dissolving evenly, add 1 kg of zinc oxide whiskers (with a diameter of 30 - 40 nm, a length of 200 - 300 nm, and an aspect ratio of 5 - 10). Disperse evenly by ultrasonic wave, then heat up to 40 °C, stir and react for 2 h, and then filter to obtain the solid and dry it to get the modified zinc oxide whisker.

[0041]

Preparation Example 1 - 3

[0042] A modified zinc oxide whisker, and its preparation method comprises the following steps:

[0043] Add 0.1 kg of vinyltriethoxysilane and 0.6 kg of amino silane coupling agent KH550 into 10 kg of ethanol aqueous solution. After stirring and dissolving evenly, add 1 kg of zinc oxide whiskers (with a diameter of 30 - 40 nm, a length of 200 - 300 nm, and an aspect ratio of 5 - 10). Disperse evenly by ultrasonic wave, then heat up to 40 °C, stir and react for 2 h, and then filter to obtain the solid and dry it to get the modified zinc oxide whisker.

[0044] Preparation Example of Modified Carbon Black

[0045]

Preparation Example 2 - 1

[0046] A modified carbon black, and its preparation method comprises the following steps:

[0047] Add 0.2 kg of vinyltriethoxysilane and 0.2 kg of epoxy silane coupling agent KH560 into 10 kg of ethanol aqueous solution. After stirring and dissolving evenly, add 1 kg of carbon black. Disperse evenly by ultrasonic wave, then heat up to 40 °C, stir and react for 2 h, and then filter to obtain the solid and dry it to get the modified carbon black.

[0048]

Preparation Example 2 - 2

[0049] A modified carbon black, and its preparation method comprises the following steps:

[0050] Add 0.05 kg of vinyltriethoxysilane and 0.35 kg of epoxy silane coupling agent KH560 into 10 kg of ethanol aqueous solution. After stirring and dissolving evenly, add 1 kg of carbon black. Disperse evenly by ultrasonic wave, then heat up to 40 °C, stir and react for 2 h, and then filter to obtain the solid and dry it to get the modified carbon black.

[0051] Examples

[0052]

Example 1

[0053] A weather-resistant and scale-resistant PE drainage pipe, comprising a scale-resistant PE inner layer and a weather-resistant PE outer layer, and the thickness ratio of the scale-resistant PE inner layer to the weather-resistant PE outer layer is 5:1. The raw materials for preparing the scale-resistant PE inner layer include 100 kg of the first HDPE resin (Formosa Plastics 8001, Taiwan), 4.5 kg of the modified zinc oxide whiskers prepared in [Preparation Example 1-1], 1 kg of polyethylene wax, and 0.005 kg of dicumyl peroxide; the raw materials for preparing the weather-resistant PE outer layer include 100 kg of the second HDPE resin (Formosa Plastics 8001, Taiwan) and 0.002 kg of PE-carbon black masterbatch. Among them, the raw materials for preparing the PE-carbon black masterbatch include 50 kg of PE resin (Formosa Plastics 8001, Taiwan), 50 kg of the modified carbon black prepared in [Preparation Example 2-1], and 0.2 kg of silicone masterbatch.

[0054] In this embodiment, the preparation method of the weather-resistant and scale-resistant PE drainage pipe comprises the following steps:

[0055] Put the raw materials for preparing the scale-resistant PE inner layer into extruder A according to the ratio, melt and mix evenly at 195 - 205 °C to obtain a scale-resistant PE inner layer melt;

[0056] Put the raw materials for preparing the weather-resistant PE outer layer into extruder B according to the ratio, melt and mix evenly at 195 - 205 °C to obtain a weather-resistant PE outer layer melt;

[0057] Distribute the scale-resistant PE inner layer melt to the inner layer of the two-layer co-extrusion die, distribute the weather-resistant PE outer layer melt to the outer layer of the two-layer co-extrusion die, and perform composite co-extrusion at 180 - 190 °C, then shape, cool, and cut under a vacuum degree of -0.02 Mpa to obtain the weather-resistant and scale-resistant PE drainage pipe.

[0058]

Example 2

[0059] A weather-resistant and scale-resistant PE drainage pipe, comprising a scale-resistant PE inner layer and a weather-resistant PE outer layer, and the thickness ratio of the scale-resistant PE inner layer to the weather-resistant PE outer layer is 5:1. The raw materials for preparing the scale-resistant PE inner layer include 100 kg of the first HDPE resin (Formosa Plastics 8001, Taiwan), 5.5 kg of the modified zinc oxide whiskers prepared in [Preparation Example 1-1], 2 kg of polyethylene wax, and 0.01 kg of dicumyl peroxide; the raw materials for preparing the weather-resistant PE outer layer include 100 kg of the second HDPE resin (Formosa Plastics 8001, Taiwan) and 0.004 kg of PE-carbon black masterbatch. Among them, the raw materials for preparing the PE-carbon black masterbatch include 60 kg of PE resin (Formosa Plastics 8001, Taiwan), 40 kg of the modified carbon black prepared in [Preparation Example 2-1], and 0.1 kg of silicone masterbatch.

[0060] In this embodiment, the preparation method of the weather-resistant and scale-resistant PE drainage pipe comprises the following steps:

[0061] Put the raw materials for preparing the anti-scaling PE inner layer into extruder A according to the ratio, and melt and mix them evenly at 195 - 205 °C to obtain the anti-scaling PE inner layer melt;

[0062] Put the raw materials for preparing the weather-resistant PE outer layer into extruder B according to the ratio, and melt and mix them evenly at 195 - 205 °C to obtain the weather-resistant PE outer layer melt;

[0063] Distribute the anti-scaling PE inner layer melt to the inner layer of the two-layer co-extrusion die, and distribute the weather-resistant PE outer layer melt to the outer layer of the two-layer co-extrusion die, and co-extrude them at 180 - 190 °C. Then, shape, cool, and cut them under a vacuum degree of -0.06 Mpa to obtain the weather-resistant and anti-scaling PE drainage pipe.

[0064]

Example 3

[0065] A weather-resistant and anti-scaling PE drainage pipe, the difference from

Example 1

[0066] The modified zinc oxide whiskers are the modified zinc oxide whiskers prepared by

Preparation Example 1 - 2

[0067]

Example 4

[0068] A weather-resistant and anti-scaling PE drainage pipe, the difference from

Example 3

[0069] In this example, the raw materials for preparing the weather-resistant PE outer layer include 100 kg of the second HDPE resin (Formosa Plastics 8001), 0.002 kg of PE-carbon black masterbatch, 6.5 kg of acrylate-capped silicone oil, and 0.012 kg of diisopropylbenzene peroxide. Among them, the acrylate-capped silicone oil specifically uses acrylate-capped silicone oil A, and the structural formula of acrylate-capped silicone oil A is as follows:

[0070] CH2=CR1COO(CH2)3SiR2R3O(SiR2R3O) n SiR2R3(CH2)3OOCCR1=CH2;

[0071] Among them, R1 is H, R2 and R3 are methyl groups, and the value of n is 45.

[0072]

Example 5

[0073] A weather-resistant and anti-scaling PE drainage pipe, the difference from

Example 4

[0074] In this example, the acrylate-capped silicone oil specifically uses acrylate-capped silicone oil B, and the structural formula of acrylate-capped silicone oil B is as follows:

[0075] CH2=CR1COO(CH2)3SiR2R3O(SiR2R3O) n SiR2R3(CH2)3OOCCR1=CH2;

[0076] Wherein, R1 is methyl, R2 is methyl, R3 is phenyl, and the value of n is 45.

[0077]

Example 6

[0078] A weather-resistant and scale-resistant PE drainage pipe, which is different from

Example 3

[0079] In this example, the acrylate-capped silicone oil adopts a composition of acrylate-capped silicone oil A and acrylate-capped silicone oil B, and the weight ratio of acrylate-capped silicone oil A to acrylate-capped silicone oil B is 1:1.

[0080]

Example 7

[0081] A weather-resistant and scale-resistant PE drainage pipe, which is different from

Example 3

[0082] In this example, the acrylate-capped silicone oil adopts a composition of acrylate-capped silicone oil A and acrylate-capped silicone oil B, and the weight ratio of acrylate-capped silicone oil A to acrylate-capped silicone oil B is 3:1.

[0083]

Example 8

[0084] A weather-resistant and scale-resistant PE drainage pipe, which is different from

Example 7

[0085]

Example 9

[0086] A weather-resistant and scale-resistant PE drainage pipe, which is different from

Example 7

Preparation Example 1-3

Preparation Example 2-2

[0087] Comparative Example

[0088]

Comparative Example 1

[0089] A PE drainage pipe, which is different from [Example 1] in that: different modified zinc oxide whiskers are used. In this comparative example, the modified zinc oxide whiskers are obtained by modifying with the amino silane coupling agent KH550.

[0090]

Comparative Example 2

[0091] A PE drainage pipe, which is different from [Example 1] in that: polyethylene wax is not added.

[0092] Performance detection test

[0093] Preparation of test specimens: According to the methods described in each example and comparative example, pipes with a nominal size of 500 mm, a minimum inner diameter of 490 mm, and a nominal wall thickness of 46 mm are prepared.

[0094] Inner wall roughness coefficient: For each example and comparative example, 10 PE drainage pipes of the same size are taken to test the inner wall roughness coefficient, and the average value is taken.

[0095] Inner wall antibacterial property: The test is carried out with reference to JC / T 939-2004 "Antibacterial Properties of Antibacterial Plastic Pipes for Building Use", and the test strain is Staphylococcus aureus.

[0096] Ring stiffness: The test is carried out with reference to GB / T9647-2015 "Determination of Ring Stiffness of Thermoplastic Pipe".

[0097] Ring flexibility: The test is carried out with reference to GB / T39385-2020 "Plastics piping systems - Determination of the ring flexibility of thermoplastic pipes".

[0098] Impact performance: For each example and comparative example, 50 PE drainage pipes of the same size are taken, and a drop hammer with a weight of 1.5 kg is used to impact the PE drainage pipe at a height of 1.0 m, and the number of damaged pipes (including the number of cracks, delaminations, and blisters) is calculated. Among them, when the damage rate ≤ 10%, it is qualified.

[0099] Low-temperature impact performance: For each example and comparative example, 50 PE drainage pipes of the same size are taken, left standing in an environment of -10 °C for 168 h, then placed at room temperature, and a drop hammer with a weight of 1.5 kg is used to impact the PE drainage pipe at a height of 1.0 m, and the number of damaged pipes (including the number of cracks, delaminations, and blisters) is calculated. Among them, when the damage rate ≤ 10%, it is qualified.

[0100] Thermal aging impact performance: For each example and comparative example, 10 PE drainage pipes of the same size are taken, left standing in an environment of 80 °C for 168 h, then cooled to room temperature, and a drop hammer with a weight of 1.5 kg is used to impact the PE drainage pipe at a height of 1.0 m, and the number of damaged pipes (including the number of cracks, delaminations, and blisters) is calculated. Among them, when the damage rate ≤ 10%, it is qualified.

[0101] Table 1

[0102]

[0103] Table 2

[0104]

[0105] Table 3

[0106]

[0107] Combined with the content recorded in Examples 1-8 and Tables 1-3, it can be seen that: the inner wall of the weather-resistant and scale-resistant PE drain pipes provided in Examples 1-8 of the present application has low roughness, good antibacterial property, high ring stiffness and ring flexibility, and has good impact performance, low-temperature impact performance and heat-aging impact performance, with excellent comprehensive performance.

[0108] Combined with the content recorded in Example 1 and Comparative Examples 1-2 and Tables 1-3, it can be seen that after the modified zinc oxide whiskers are modified separately with a vinyl-free silane coupling agent or the addition of polyethylene wax is omitted, it is not conducive to the uniform dispersion of the modified zinc oxide, and it is difficult to obtain a PE drain pipe with a pipe wall roughness coefficient lower than 0.011. In addition, the antibacterial persistence of the PE drain pipe also decreases, and scale formation is likely to occur after long-term use.

[0109] Combined with the content recorded in Example 1 and Example 3 and Tables 1-3, it can be seen that in the PE scale-resistant inner layer, the product obtained by co-modifying zinc oxide whiskers with vinyltriethoxysilane and amino-silane coupling agent KH550 can further improve the ring stiffness, low-temperature impact resistance and heat-aging impact resistance of the PE drain pipe, that is, it is beneficial to further improve the strength and weather resistance of the PE drain pipe.

[0110] Combined with the content recorded in Example 3 and Examples 4-8 and Tables 1-3, it can be seen that in the weather-resistant PE outer layer, adding acrylate-capped silicone oil or vinyl-capped silicone oil to crosslink and modify the main resin of the weather-resistant PE outer layer is beneficial to improving the heat-aging performance of the PE drain pipe. Among them, when the acrylate-capped silicone oil adopts a composition of acrylate-capped silicone oil A and acrylate-capped silicone oil B with a weight ratio of 3:1, it can effectively improve the heat-aging performance while improving the ring stiffness and low-temperature impact resistance of the PE drain pipe, so as to obtain a PE drain pipe with excellent weather resistance.

[0111] Combined with the content recorded in Example 7 and Example 9 and Tables 1-3, it can be seen that the weight ratio of the two silane coupling agents in the modified zinc oxide whiskers and modified carbon black affects the pipe wall roughness coefficient, ring stiffness, low-temperature impact resistance and heat-aging impact resistance of the PE drain pipe.

[0112] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this specific embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A weather-resistant and scale-resistant PE drainage pipe, characterized in that: It includes an anti-scaling PE inner layer and a weather-resistant PE outer layer. The raw materials for preparing the anti-scaling PE inner layer include 100 parts by weight of a first HDPE resin, 4.5 - 5.5 parts by weight of modified zinc oxide whiskers, 1 - 2 parts by weight of polyolefin wax, and 0.005 - 0.01 parts by weight of a first initiator; the raw materials for preparing the weather-resistant PE outer layer include 100 parts by weight of a second HDPE resin, 0.002 - 0.004 parts by weight of a PE-carbon black masterbatch, 6.5 - 7.5 parts by weight of acrylate-capped silicone oil, and 0.01 - 0.015 parts by weight of a second initiator; The modified zinc oxide whiskers are obtained by jointly modifying zinc oxide whiskers with a vinyl / allyl silane coupling agent and an amino silane coupling agent. In the raw materials for preparing the modified zinc oxide whiskers, the weight ratio of the vinyl / allyl silane coupling agent, the amino silane coupling agent, and the zinc oxide whiskers is (0.3 - 0.4):(0.3 - 0.4):1; The raw materials for preparing the PE-carbon black masterbatch include 50 - 60 parts by weight of a PE resin, 40 - 50 parts by weight of modified carbon black, and 0.1 - 0.2 parts by weight of a silicone masterbatch; among them, the modified carbon black is obtained by jointly modifying carbon black with a vinyl / allyl silane coupling agent and an epoxy silane coupling agent. In the raw materials for preparing the modified carbon black, the weight ratio of the vinyl / allyl silane coupling agent, the epoxy silane coupling agent, and the carbon black is (0.15 - 0.25):(0.15 - 0.25):1; The acrylate-capped silicone oil includes acrylate-capped silicone oil A and acrylate-capped silicone oil B with a weight ratio of (3 - 4):

1. The structural general formulas of acrylate-capped silicone oil A and acrylate-capped silicone oil B are as follows: CH2=CR1COO(CH2)3SiR2R3O(SiR2R3O) n SiR2R3(CH2)3OOCCR1=CH2; Among them, in acrylate-capped silicone oil A, R1 is H, R2 and R3 are methyl groups, and the value range of n is 40 - 50; in acrylate-capped silicone oil B, R1 is methyl, R2 is methyl, R3 is phenyl, and the value range of n is 40 - 50.

2. The weather-resistant and scale-resistant PE drain pipe according to claim 1, wherein: The diameter of the modified zinc oxide whiskers is 30 - 40 nm, the length is 200 - 300 nm, and the aspect ratio is 5 - 10.

3. A weather-resistant and scale-resistant PE drainage pipe according to any one of claims 1-2, characterized in that: The thickness ratio of the anti-scaling PE inner layer to the weather-resistant PE outer layer is (4 - 6):

1.

4. A preparation method of a weather-resistant and scale-resistant PE drainage pipe according to any one of claims 1-3, characterized in that, It includes the following steps: Put the raw materials for preparing the anti-scaling PE inner layer into extruder A according to the ratio, and melt and mix them evenly at 195 - 205 °C to obtain an anti-scaling PE inner layer melt; Put the raw materials for preparing the weather-resistant PE outer layer into extruder B according to the ratio, and melt and mix them evenly at 195 - 205 °C to obtain a weather-resistant PE outer layer melt; Distribute the anti-scaling PE inner layer melt to the inner layer of a two-layer co-extrusion die, distribute the weather-resistant PE outer layer melt to the outer layer of the two-layer co-extrusion die, and co-extrude and compound them at 180 - 190 °C, then vacuum shape, cool, and cut to obtain a weather-resistant and anti-scaling PE drainage pipe.

5. The preparation method of a weather-resistant and scale-resistant PE drainage pipe according to claim 4, characterized in that: In the vacuum shaping step, the vacuum degree is controlled to be -0.02 Mpa to -0.06 Mpa.

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