Multifunctional Masterbatch for Recycled High-Density Polyethylene Pipe Material and Its Preparation Method

Abstract

This invention relates to the field of polymer materials, and particularly to a multifunctional masterbatch for recycled high-density polyethylene (HDPE) pipe materials and its preparation method. It is composed of the following raw materials in parts by weight: 93.5-99.7 parts carrier; 0.1-5 parts multifunctional additive; 0.1-0.5 parts dispersant; and 0.1-1 parts other additives. Compared with the prior art, the multifunctional masterbatch for recycled HDPE pipe materials of this invention can effectively reduce the melt flow rate of recycled HDPE while improving the tensile strength and impact strength of HDPE. Furthermore, this multifunctional masterbatch has the advantages of low dosage, low cost, and no irritating odor.

Description

[Technical Field]

[0001] This invention relates to the field of polymer materials, and in particular to a multifunctional masterbatch for recycled high-density polyethylene pipe materials and its preparation method. [Background Technology]

[0002] Technological advancements in polymer materials have driven the rapid development of the global plastics industry. my country's plastics industry has also grown rapidly, with annual output increasing at a rate of over 10%. Consequently, the amount of plastic products consumed each year has also increased, generating a large amount of waste plastics. If waste plastics are not recycled and processed in a timely manner, it will not only waste resources but also cause great harm to the environment.

[0003] HDPE pipes possess outstanding properties such as corrosion resistance, temperature resistance, abrasion resistance, no pollution to the transported medium, long service life, and low manufacturing and installation costs. They have been widely used in gas transmission, water supply, heating, and building water supply and drainage, and their usage has grown rapidly in recent years. However, producing HDPE pipes from virgin materials consumes petroleum resources and exacerbates environmental pressure. Therefore, recycling, modifying, and reusing recycled HDPE for pipe manufacturing has become an important method to reduce HDPE costs and improve the environment.

[0004] Currently, the main base material for recycled HDPE used in the HDPE pipe industry is small hollow recycled material, which comes from milk bottles, juice bottles, shampoo bottles, and shower gel bottles. After repeated heating and UV irradiation, these recycled polyethylene materials undergo partial degradation and aging, resulting in a decrease in molecular weight. Furthermore, the addition of small amounts of injection-grade polyethylene or polypropylene during the recycling process leads to a high melt flow rate and low melt strength. Direct application in pipe production can cause "melt sag," resulting in uneven pipe thickness. In addition, pure small hollow recycled material has insufficient mechanical properties, posing a risk of pipe breakage if used directly. Therefore, the recycled small hollow material needs to be modified before use.

[0005] Chinese patent CN106117746A discloses a high-density polyethylene toughening masterbatch, its preparation method, and its application in high-density polyethylene pipes. This invention toughens HDPE by adding carboxyl-terminated nitrile rubber to high-density polyethylene resin and adding ultrafine phosphogypsum powder to compensate for the decrease in rigidity and reduce costs. However, it does not improve the melt flow rate and tensile strength of the material, and the addition of ultrafine phosphogypsum powder increases the ash content of the pipe material.

[0006] Chinese patent CN102585256A (abandoned) discloses a method for toughening recycled high-density polyethylene plastic. This invention prepares high-density polyethylene with a toughness increase of more than 75% by adding LDPE and crosslinking agents to recycled high-density polyethylene material. However, the addition of LDPE will cause a decrease in the rigidity of the material, and it also uses peroxide crosslinking agents with a strong pungent odor and phthalic crosslinking agents that do not meet RoHS requirements.

[0007] Chinese patent CN110776687B discloses a PE melt flow index regulating masterbatch and its preparation method. This invention uses peroxide grafted with maleic anhydride onto polyethylene to prepare a masterbatch with excellent melt flow rate regulating function, effectively reducing the melt flow rate of recycled polyethylene. However, it does not study the mechanical properties of recycled polyethylene and also uses peroxide compounds with an irritating odor.

[0008] Existing toughening modification methods for recycled high-density polyethylene (HDPE) include blending with LDPE, LLDPE, or thermoplastic elastomers POE and SEBS. These methods are costly and significantly reduce the tensile strength and flexural modulus of HDPE. Using peroxide crosslinking to reduce the melt flow rate of recycled HDPE has drawbacks: strong odor, difficulty in dispersion due to insufficient dosage, low decomposition temperature, and difficulty in controlling the degree of crosslinking, leading to uneven material properties and surface defects. [Summary of the Invention]

[0009] To overcome the above problems, this invention proposes a multifunctional masterbatch for recycled high-density polyethylene pipe materials and its preparation method, which can effectively solve the above problems.

[0010] The present invention provides a technical solution to the above-mentioned technical problems: a multifunctional masterbatch for recycled high-density polyethylene pipe materials is composed of the following raw materials in parts by mass:

[0011]

[0012] The multifunctional additive is one or more of the following: bismaleimide, m-phenylenebismaleimide, N,N'-(4,4'-methylenediphenyl)bismaleimide, and 1,6-bis(maleimide)hexane.

[0013] Preferably, the carrier is one or more of HDPE, LDPE, LLDPE raw materials or recycled materials.

[0014] Preferably, the dispersant is one or more of naphthenic oil, paraffin oil, and aromatic oil.

[0015] Preferably, the other additives are one or more of lubricants, fillers, antioxidants, and colorants.

[0016] A method for preparing a multifunctional masterbatch for recycled high-density polyethylene pipe materials is provided, comprising the following steps:

[0017] Step S1: Prepare the raw materials of each component according to the formula;

[0018] Step S2: Add the multifunctional additive and other additives into a high-speed mixer and mix to obtain pre-dispersed material A; in step S2, the mixing time is 20-30 minutes.

[0019] Step S3: Add the carrier and dispersant to a high-speed mixer and mix to obtain material B; in step S3, the mixing time is 5 to 10 minutes.

[0020] Step S4: Add material A and material B into a high-speed mixer and mix to obtain material C; in step S4, the mixing time is 10 to 20 minutes.

[0021] In step S5, material C is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded. In step S5, the extrusion temperature of the twin-screw extruder is 120–165°C.

[0022] Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch granules.

[0023] Preferably, the high-speed mixer has a rotational speed of 300-800 r / min, and the twin-screw extruder has a screw rotational speed of 150-300 r / min.

[0024] A method for preparing recycled high-density polyethylene pipe material is provided, comprising the following steps:

[0025] Step X1: HDPE small hollow recycled material and multifunctional masterbatch are added to a horizontal mixer in proportion and mixed to obtain material D; in step X1, the mixing time is 30 to 60 minutes.

[0026] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, and then mixed, plasticized, and extruded by the twin-screw extruder to obtain material E; in step X2, the extrusion temperature of the twin-screw extruder is set to 160-240℃.

[0027] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material.

[0028] Preferably, in step X1, the HDPE small hollow recycled material and the multifunctional masterbatch are arranged in the following mass proportions:

[0029] 90-99.5 parts of HDPE small hollow recycled material;

[0030] Multifunctional masterbatch 0.5 to 10 parts.

[0031] Preferably, the HDPE small hollow recycled material has a melt flow rate of 1.3-2.5 g / 10 min (190℃, 5 kg), a moisture content of <1.5%, and an ash content of <3%.

[0032] Preferably, the horizontal mixer has a rotation speed of 30-200 r / min, and the twin-screw extruder has a screw rotation speed of 200-600 r / min.

[0033] Compared with the prior art, the present invention provides a multifunctional masterbatch for recycled high-density polyethylene pipe materials, which can effectively reduce the melt flow rate of recycled HDPE while improving the tensile strength and impact strength of HDPE. In addition, this multifunctional masterbatch has the advantages of low addition amount, low cost and no irritating odor. [Specific implementation method]

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0035] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] The multifunctional masterbatch for recycled high-density polyethylene pipe materials of the present invention is composed of the following raw materials in parts by weight:

[0037]

[0038] The carrier is one or more of the following: HDPE (high-density polyethylene), LDPE (low-density polyethylene), LLDPE (linear low-density polyethylene) raw materials or recycled materials. Recycled materials include recycled HDPE film granules, recycled LDPE film granules, recycled LLDPE film granules, and recycled LDPE / PA composite film granules.

[0039] The multifunctional additive is one or more of the following: bismaleimide, m-phenylenebismaleimide, N,N'-(4,4'-methylenediphenyl)bismaleimide, and 1,6-bis(maleimide)hexane.

[0040] The dispersant is one or more of naphthenic oil, paraffinic oil, and aromatic oil. The naphthenic oil includes naphthenes. The paraffinic oil includes Fischer-Tropsch wax.

[0041] The other additives are one or more of the following: lubricants, fillers, antioxidants, and colorants. The fillers include nano-silica.

[0042] The preparation method of the multifunctional masterbatch for recycled high-density polyethylene pipe materials of the present invention includes the following steps:

[0043] Step S1: Prepare the raw materials of each component according to the formula.

[0044] Step S2: Add the multifunctional additive and other additives to a high-speed mixer and mix to obtain pre-dispersed material A. In step S2, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 20-30 minutes.

[0045] Step S3: The carrier and dispersant are added to a high-speed mixer and mixed to obtain material B. In step S3, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 5-10 minutes.

[0046] In step S4, materials A and B are added to a high-speed mixer and mixed to obtain material C. In step S4, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 10-20 minutes.

[0047] In step S5, material C is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded. In step S5, the extrusion temperature of the twin-screw extruder is 120–165°C, and the screw speed is 150–300 r / min.

[0048] Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch granules.

[0049] The method for preparing recycled high-density polyethylene pipe material of the present invention includes the following steps:

[0050] Step X1: HDPE small hollow recycled material and multifunctional masterbatch are added to a horizontal mixer in a certain proportion and mixed to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0051] In step X1, the HDPE small hollow recycled material and the multifunctional masterbatch are arranged in the following mass proportions:

[0052] 90-99.5 parts of HDPE small hollow recycled material;

[0053] Multifunctional masterbatch 0.5-10 parts;

[0054] The HDPE small hollow recycled material has a melt flow rate of 1.3 to 2.5 g / 10 min (190℃, 5 kg), a moisture content of <1.5%, and an ash content of <3%.

[0055] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0056] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material.

[0057] The present invention will be further described below with reference to specific embodiments.

[0058] Example 1: A multifunctional masterbatch for recycled high-density polyethylene pipe materials.

[0059] Step S1, Raw material selection: by mass, 97 parts LLDPE raw material, 2 parts m-phenylene bismaleimide, 0.1 parts cycloalkanes, 0.4 parts Fischer-Tropsch wax, and 0.5 parts nano silica.

[0060] In step S2, m-phenylenebismaleimide, Fischer-Tropsch wax, and nano-silica are added to a high-speed mixer and mixed to obtain pre-dispersed material A. In step S2, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 20-30 minutes.

[0061] Step S3: Add LLDPE raw materials and cycloalkanes to a high-speed mixer and mix to obtain material B. In step S3, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 5-10 minutes.

[0062] In step S4, materials A and B are added to a high-speed mixer and mixed to obtain material C. In step S4, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 10-20 minutes.

[0063] In step S5, material C is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded. In step S5, the extrusion temperature of the twin-screw extruder is 120–165°C, and the screw speed is 150–300 r / min.

[0064] Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch granules 1.

[0065] Example 2, a multifunctional masterbatch for recycled high-density polyethylene pipe materials 2.

[0066] Step S1, Raw material selection: by mass, 94 parts of recycled LDPE film granules, 5 parts of m-phenylene bismaleimide, 0.2 parts of cycloalkanes, 0.3 parts of Fischer-Tropsch wax, and 0.5 parts of nano-silica.

[0067] In step S2, m-phenylenebismaleimide, Fischer-Tropsch wax, and nano-silica are added to a high-speed mixer and mixed to obtain pre-dispersed material A. In step S2, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 20-30 minutes.

[0068] Step S3: The recycled LDPE membrane granules and cycloalkanes are added to a high-speed mixer and mixed to obtain material B. In step S3, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 5-10 minutes.

[0069] In step S4, materials A and B are added to a high-speed mixer and mixed to obtain material C. In step S4, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 10-20 minutes.

[0070] In step S5, material C is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded. In step S5, the extrusion temperature of the twin-screw extruder is 120–165°C, and the screw speed is 150–300 r / min.

[0071] Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch granules 2.

[0072] Example 3: A multifunctional masterbatch 3 for recycled high-density polyethylene pipe materials.

[0073] Step S1, Raw material selection: By mass, 96.5 parts of recycled LDPE / PA composite film granules, 2.5 parts of m-phenylene bismaleimide, 0.1 parts of cycloalkanes, 0.4 parts of Fischer-Tropsch wax, and 0.5 parts of nano-silica.

[0074] In step S2, m-phenylenebismaleimide, Fischer-Tropsch wax, and nano-silica are added to a high-speed mixer and mixed to obtain pre-dispersed material A. In step S2, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 20-30 minutes.

[0075] Step S3: Add the recycled LDPE / PA composite membrane granules and cycloalkanes to a high-speed mixer and mix to obtain material B. In step S3, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 5-10 minutes.

[0076] In step S4, materials A and B are added to a high-speed mixer and mixed to obtain material C. In step S4, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 10-20 minutes.

[0077] In step S5, material C is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded. In step S5, the extrusion temperature of the twin-screw extruder is 120–165°C, and the screw speed is 150–300 r / min.

[0078] Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch granules 3.

[0079] Example 4: A multifunctional masterbatch for recycled high-density polyethylene pipe materials.

[0080] Step S1, Raw material selection: By mass, 96.5 parts of recycled LDPE film granules, 1 part of m-phenylenebismaleimide, 1.5 parts of 1,6-di(maleimide)hexane, 0.2 parts of cycloalkanes, 0.3 parts of Fischer-Tropsch wax, and 0.5 parts of nano-silica.

[0081] In step S2, m-phenylenebismaleimide, 1,6-di(maleimide)hexane, Fischer-Tropsch wax, and nano-silica are added to a high-speed mixer and mixed to obtain pre-dispersed material A. In step S2, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 20-30 minutes.

[0082] Step S3: The recycled LDPE membrane granules and cycloalkanes are added to a high-speed mixer and mixed to obtain material B. In step S3, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 5-10 minutes.

[0083] In step S4, materials A and B are added to a high-speed mixer and mixed to obtain material C. In step S4, the speed of the high-speed mixer is set to 300-800 r / min, and the mixing time is 10-20 minutes.

[0084] In step S5, material C is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded. In step S5, the extrusion temperature of the twin-screw extruder is 120–165°C, and the screw speed is 150–300 r / min.

[0085] Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch particles 4.

[0086] Example 5, a recycled high-density polyethylene pipe material 1.

[0087] Step X1: By weight, 98 parts of HDPE small hollow recycled material and 2 parts of multifunctional masterbatch 1 are added to a horizontal mixer in a specific ratio and mixed to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0088] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0089] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 1.

[0090] Example 6, a recycled high-density polyethylene pipe material 2.

[0091] Step X1: By weight, 98 parts of HDPE small hollow recycled material and 2 parts of multifunctional masterbatch 2 are added to a horizontal mixer in a specific ratio and mixed to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0092] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0093] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 2.

[0094] Example 7, a recycled high-density polyethylene pipe material 3.

[0095] Step X1: By weight, 97.6 parts of HDPE small hollow recycled material and 2.4 parts of multifunctional masterbatch 3 are added to a horizontal mixer in a certain proportion to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0096] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0097] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 3.

[0098] Example 8, a recycled high-density polyethylene pipe material 4.

[0099] Step X1: By weight, 97.6 parts of HDPE small hollow recycled material and 2.4 parts of multifunctional masterbatch 4 are added to a horizontal mixer in a certain proportion to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0100] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0101] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 4.

[0102] Example 9, a recycled high-density polyethylene pipe material 5.

[0103] Step X1: By weight, 96 parts of HDPE small hollow recycled material and 4 parts of multifunctional masterbatch 4 are added to a horizontal mixer in a specific ratio and mixed to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0104] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0105] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 5.

[0106] Example 10, a recycled high-density polyethylene pipe material 6.

[0107] Step X1: By weight, 92 parts of HDPE small hollow recycled material and 8 parts of multifunctional masterbatch 4 are added to a horizontal mixer in a specific ratio and mixed to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0108] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0109] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 6.

[0110] Comparative Example 1: A recycled high-density polyethylene pipe material 7.

[0111] Step X1: By weight, 98 parts of HDPE small hollow recycled material and 2 parts of POE (polyethylene octene co-elastomer) are added to a horizontal mixer in a specific ratio and mixed to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0112] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0113] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 7.

[0114] Comparative Example 2, a recycled high-density polyethylene pipe material 8.

[0115] Step X1: By weight, 80 parts of HDPE small hollow recycled material and 20 parts of LLDPE are added to a horizontal mixer in a specific ratio and mixed to obtain material D. In step X1, the speed of the horizontal mixer is set to 30-200 r / min, and the mixing time is 30-60 minutes.

[0116] Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240°C, and the screw speed is set to 200–600 r / min.

[0117] Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 8.

[0118] Comparative Example 3, a recycled high-density polyethylene pipe material 9.

[0119] Step X1: By weight, 100 parts of recycled HDPE small hollow core material are fed into the feeding hopper of a twin-screw extruder. The material is then mixed, plasticized, and extruded through the twin-screw extruder to obtain material E. In step X2, the extrusion temperature of the twin-screw extruder is set to 160–240℃, and the screw speed to 200–600 r / min.

[0120] Step X2: Cool and granulate material E to obtain recycled high-density polyethylene pipe material 9.

[0121] The recycled high-density polyethylene pipe materials prepared in Examples 5-10 and Comparative Examples 1-3 were subjected to performance tests, and the results are shown in the table below.

[0122]

[0123] Compared to Comparative Example 3, adding POE elastomer to Comparative Example 1 improved the impact strength of recycled HDPE. Although the melt flow rate was also improved, it caused a decrease in the tensile strength and flexural modulus of the recycled HDPE. Adding LLDPE to Comparative Example 2 improved the impact strength of recycled HDPE, but it increased the melt flow rate of the recycled HDPE and caused a significant decrease in the tensile strength and flexural modulus of the recycled HDPE.

[0124] Examples 5-10 show that adding multifunctional masterbatch can effectively reduce the melt flow rate of recycled HDPE, improve its impact strength, tensile strength, and flexural modulus. Examples 8-10 demonstrate that by increasing the amount of multifunctional masterbatch added, recycled HDPE pipe materials with progressively improved overall performance can be obtained. Example 6 illustrates that by increasing the amount of multifunctional additive, a higher concentration of multifunctional masterbatch can be prepared, and even a relatively low amount can significantly improve the overall performance of recycled HDPE pipe materials.

[0125] Compared with the prior art, the present invention provides a multifunctional masterbatch for recycled high-density polyethylene pipe materials, which can effectively reduce the melt flow rate of recycled HDPE while improving the tensile strength and impact strength of HDPE. In addition, this multifunctional masterbatch has the advantages of low addition amount, low cost and no irritating odor.

[0126] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any modifications, equivalent substitutions and improvements made within the concept of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A multifunctional masterbatch for recycled high-density polyethylene pipe materials, characterized in that, Composed of the following raw materials in parts by weight: The carrier comprises 93.5-99.7 parts, wherein the carrier is one or more of LDPE, LLDPE raw materials or recycled materials, and the recycled materials are recycled LDPE membrane granules, recycled LLDPE membrane granules, or recycled LDPE / PA composite membrane granules. 2-5 parts of a multifunctional additive, wherein the multifunctional additive is a mixture of m-phenylene bismaleimide and 1,6-di(maleimide)hexane, and the mass ratio of m-phenylene bismaleimide to 1,6-di(maleimide)hexane is 2:3; 0.1-0.5 parts of dispersant, wherein the dispersant is naphthenic oil; Other additives: 0.8-1 parts, wherein the other additives are lubricants and nano-silica, and the nano-silica is 0.5 parts; The preparation method of the multifunctional masterbatch for recycled high-density polyethylene pipe materials includes the following steps: Step S1: Prepare the raw materials of each component according to the formula; Step S2: Add the multifunctional additive and other additives into a high-speed mixer and mix to obtain pre-dispersed material A; in step S2, the mixing time is 20-30 minutes. Step S3: Add the carrier and dispersant to a high-speed mixer and mix to obtain material B; in step S3, the mixing time is 5-10 minutes. Step S4: Add material A and material B into a high-speed mixer and mix to obtain material C; in step S4, the mixing time is 10-20 minutes. In step S5, material C is fed into the feeding hopper of a twin-screw extruder, where it is mixed, plasticized, and extruded. In step S5, the extrusion temperature of the twin-screw extruder is 120~165℃. Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch granules.

2. A method for preparing a multifunctional masterbatch for recycled high-density polyethylene pipe materials as described in claim 1, characterized in that, Includes the following steps: Step S1: Prepare the raw materials of each component according to the formula; Step S2: Add the multifunctional additive and other additives into a high-speed mixer and mix to obtain pre-dispersed material A; in step S2, the mixing time is 20-30 minutes. Step S3: Add the carrier and dispersant to a high-speed mixer and mix to obtain material B; in step S3, the mixing time is 5-10 minutes. Step S4: Add material A and material B into a high-speed mixer and mix to obtain material C; in step S4, the mixing time is 10-20 minutes. Step S5: Material C is fed into the feeding hopper of the twin-screw extruder, and then mixed, plasticized, and extruded by the twin-screw extruder. In step S5, the extrusion temperature of the twin-screw extruder is 120~165℃; Step S6 involves cooling and granulating the material extruded through the twin-screw extruder die to obtain multifunctional masterbatch granules.

3. The method for preparing the multifunctional masterbatch for recycled high-density polyethylene pipe materials as described in claim 2, characterized in that, The high-speed mixer has a rotation speed of 300~800 r / min, and the twin-screw extruder has a screw rotation speed of 150~300 r / min.

4. A method for preparing recycled high-density polyethylene pipe material, characterized in that, Includes the following steps: Step X1: HDPE small hollow recycled material and the multifunctional masterbatch described in claim 1 are added to a horizontal mixer in proportion and mixed to obtain material D; in step X1, the mixing time is 30~60 minutes. Step X2: Material D is fed into the feeding hopper of a twin-screw extruder, and then mixed, plasticized, and extruded by the twin-screw extruder to obtain material E; in step X2, the extrusion temperature of the twin-screw extruder is set to 160~240℃. Step X3: Cool and granulate material E to obtain recycled high-density polyethylene pipe material; In step X1, the HDPE small hollow recycled material and the multifunctional masterbatch are arranged in the following mass parts: 90-99.5 parts of HDPE small hollow recycled material; Multifunctional masterbatch 0.5~10 parts.

5. The method for preparing recycled high-density polyethylene pipe material as described in claim 4, characterized in that, The HDPE small hollow recycled material has a melt flow rate of 1.3~2.5g / 10min, a moisture content of <1.5%, and an ash content of <3% under the international standard test conditions of 190℃ and 5kg.

6. The method for preparing recycled high-density polyethylene pipe material as described in claim 4, characterized in that, The horizontal mixer has a rotation speed of 30~200 r / min, and the twin-screw extruder has a screw rotation speed of 200~600 r / min.

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