Polyethylene composite material, preparation method thereof and polyethylene product

Abstract

The invention relates to a polyethylene composite material, a preparation method thereof and a polyethylene product. The polyethylene composite material is prepared from the following raw materials in parts by weight: 60-70 parts of first polyethylene; 10 to 20 parts of polyethylene; 10 to 20 parts of third polyethylene; and 0.9 to 2 parts of an auxiliary agent. The viscosity-average molecular weight of the first polyethylene is 200,000-300,000, the viscosity-average molecular weight of the second polyethylene is 25,000-35,000, and the viscosity-average molecular weight of the third polyethylene is 600,000-1,000,000. The first polyethylene, the second polyethylene and the third polyethylene with different viscosity-average molecular weights are matched with the auxiliary agent according to a specific proportion, so that the environmental stress cracking resistance is greatly improved on the basis of ensuring that the mechanical property is not influenced, and the environmental stress cracking resistance can be met; meanwhile, the polyethylene composite material also has better processability.

Description

Technical Field

[0001] The present application relates to the field of material technology, and in particular to a polyethylene composite material and a preparation method thereof, and a polyethylene product. Background Art

[0002] Polyethylene is a polymer compound formed by the polymerization of ethylene. It is widely used in the fields of industry, agriculture, medicine, health and daily necessities. It is the first of the five largest synthetic resins in terms of global production and consumption. Polyethylene has strong rigidity and toughness, as well as good solvent resistance and steam permeation resistance. It is widely used in corrosion-resistant strong acid containers, oil tanks, oil drums, food packaging, and other container shells. However, traditional polyethylene materials are prone to brittle cracking when encountering surfactants such as alcohol, soap, and detergent under certain stress conditions.

[0003] Therefore, it is necessary to improve the traditional technology. Summary of the invention

[0004] Based on this, the present application provides a polyethylene composite material having good resistance to environmental stress cracking while taking into account processing performance, a preparation method thereof, and a polyethylene product.

[0005] The technical solution of this application to solve the above technical problems is as follows.

[0006] On one hand, the present application provides a polyethylene composite material, wherein the raw materials for preparing the polyethylene composite material include, by weight:

[0007] 60 to 70 parts of the first polyethylene;

[0008] 10 to 20 parts of the second polyethylene;

[0009] 10 to 20 parts of the third polyethylene; and

[0010] Additives 0.9~2 parts;

[0011] The viscosity average molecular weight of the first polyethylene is 200,000 to 300,000, the viscosity average molecular weight of the second polyethylene is 25,000 to 35,000, and the viscosity average molecular weight of the third polyethylene is 600,000 to 1,000,000.

[0012] In some embodiments, in the polyethylene composite material, the density of the first polyethylene is 0.955 g / cm 3 ~0.96 g / cm 3 .

[0013] In some embodiments, in the polyethylene composite material, the density of the second polyethylene is 0.92 g / cm 3 ~0.93 g / cm 3.

[0014] In some embodiments, in the polyethylene composite material, the density of the third polyethylene is 0.945 g / cm 3 ~0.95 g / cm 3 .

[0015] In some embodiments, in the polyethylene composite material, the melt index of the first polyethylene at 2.16 kg and 190° C. is 1 g / 10 min to 3 g / 10 min; and / or

[0016] The melt index of the second polyethylene at 2.16 kg and 190° C. is 2 g / 10 min to 3 g / 10 min; and / or

[0017] The third polyethylene has a melt index of 0.3 g / 10 min to 0.5 g / 10 min at 21.6 kg and 190° C.

[0018] In some of the embodiments, in the polyethylene composite material, the additive includes at least one of an antioxidant additive, a light stabilizing additive and a lubricating additive.

[0019] In some of the embodiments, in the polyethylene composite material, in the raw materials for preparing the polyethylene composite material, the additives include 0.3 to 0.5 parts of antioxidant additives, 0.3 to 0.5 parts of light stabilizing additives and 0.3 to 1 parts of lubricating additives, by weight.

[0020] In some embodiments, in the polyethylene composite material, the antioxidant comprises at least one of hindered phenols, phosphites and thioesters; and / or

[0021] The light stabilizing agent includes at least one of hindered amines and ultraviolet absorbers; and / or

[0022] The lubricating aid includes a metal soap lubricant.

[0023] On the one hand, the present application provides a method for preparing a polyethylene composite material, comprising the following steps:

[0024] In parts by weight, 60 to 70 parts of a first polyethylene, 10 to 20 parts of a second polyethylene, 10 to 20 parts of a third polyethylene and 0.9 to 2 parts of an additive are melt-blended and extruded and granulated in sequence to prepare a polyethylene composite material; wherein the viscosity average molecular weight of the first polyethylene is 200,000 to 300,000, the viscosity average molecular weight of the second polyethylene is 25,000 to 35,000, and the viscosity average molecular weight of the third polyethylene is 600,000 to 1,000,000.

[0025] In one aspect, the present application provides a polyethylene product, comprising the polyethylene composite material mentioned above or the polyethylene composite material prepared by the above preparation method.

[0026] Compared with the prior art, the polyethylene composite material of the present application has the following beneficial effects:

[0027] The polyethylene composite material of the present application is prepared by combining the first polyethylene, the second polyethylene, and the third polyethylene with different viscosity-average molecular weights with an additive in a specific proportion, thereby greatly improving the environmental stress cracking resistance while ensuring that the mechanical properties are not affected, so that the polyethylene composite material can meet the requirements of environmental stress resistance applications; at the same time, the polyethylene composite material also has good processing performance. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in conjunction with the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0029] It should also be understood that the present application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent forms obtained also fall within the scope of protection of the present application. For example, the features illustrated or described as part of one embodiment can be combined in another embodiment in a suitable manner to produce a new embodiment. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application. It should be understood that the present application can be implemented without one or more of these details.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing implementation modes and embodiments and are not intended to limit this application.

[0031] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0032] In the present application, "plurality", "multiple", "multiple times", etc., unless otherwise specified, refer to a quantity greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0033] As used herein, "combination thereof", "any combination thereof", "any combination thereof" etc. include all suitable combinations of any two or more of the listed items.

[0034] Herein, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc., shall be based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0035] Herein, "preferred", "better", "more preferred", and "suitable" are only used to describe implementation methods or examples with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of this application. If multiple "preferred" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "preferred" item is independent.

[0036] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0037] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0038] In the present application, the terms "first", "second", "third", "fourth", etc. in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0039] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0040] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed herein should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including numerical interval types such as percentage intervals, ratio intervals, and ratio intervals.

[0041] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0042] In this application, the term "room temperature" or "normal temperature" generally refers to 4°C to 35°C, for example, 20°C ± 5°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10°C to 30°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 20°C to 30°C.

[0043] In this application, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0044] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the invention purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0045] The mass or weight of the relevant components mentioned in the specification of the embodiments of the present application may not only refer to the specific content of each component, but also indicate the proportional relationship of the mass or weight between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the specification of the embodiments of the present application, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass or weight described in the specification of the embodiments of the present application may be units known in the chemical industry such as μg, mg, g, and kg.

[0046] An embodiment of the present application provides a polyethylene composite material. The raw materials for preparing the polyethylene composite material include, by weight:

[0047] 60 to 70 parts of the first polyethylene;

[0048] 10 to 20 parts of the second polyethylene;

[0049] 10 to 20 parts of the third polyethylene; and

[0050] Additives 0.9~2 parts;

[0051] The viscosity average molecular weight of the first polyethylene is 200,000 to 300,000, the viscosity average molecular weight of the second polyethylene is 25,000 to 35,000, and the viscosity average molecular weight of the third polyethylene is 600,000 to 1,000,000.

[0052] The polyethylene composite material of the present application is prepared by combining the first polyethylene, the second polyethylene, and the third polyethylene with different viscosity-average molecular weights with an additive in a specific proportion, thereby greatly improving the environmental stress cracking resistance while ensuring that the mechanical properties are not affected, so that the polyethylene composite material can meet the requirements of environmental stress resistance applications; at the same time, the polyethylene composite material also has good processing performance.

[0053] It can be understood that in the raw materials for preparing polyethylene composite materials, the weight parts of the first polyethylene include but are not limited to 60 parts, 62 parts, 65 parts, 68 parts, and 70 parts; the weight parts of the second polyethylene include but are not limited to 10 parts, 12 parts, 13 parts, 15 parts, 16 parts, 17 parts, 18 parts, and 20 parts; the weight parts of the third polyethylene include but are not limited to 10 parts, 12 parts, 13 parts, 15 parts, 16 parts, 17 parts, 18 parts, and 20 parts; the weight parts of the auxiliary agent include but are not limited to 0.9 parts, 1 parts, 1.2 parts, 1.55 parts, 1.8 parts, and 2 parts; in some examples, any two of these point values ​​can be within the range formed by the end values, the same below.

[0054] Furthermore, the viscosity average molecular weight of the first polyethylene includes but is not limited to 200,000, 210,000, 220,000, 230,000, 240,000, 250,000, 260,000, 270,000, 280,000, 290,000, and 300,000; the viscosity average molecular weight of the second polyethylene includes but is not limited to 25,000, 26,000, 27,000, 28,000, 29,000, 30,000, 31,000, 32,000, 33,000, 34,000, and 35,000; the viscosity average molecular weight of the third polyethylene includes but is not limited to 600,000, 620,000, 650,000, 680,000, 700,000, 720,000, 750,000, 780,000, 800,000, 820,000, 850,000, 880,000, 900,000, 920,000, 950,000, 980,000, and 1 million.

[0055] In some of the examples, in the polyethylene composite material, the raw materials for preparing the polyethylene composite material include, by weight:

[0056] 60 to 65 parts of the first polyethylene;

[0057] 16 to 20 parts of the second polyethylene;

[0058] 17 to 20 parts of the third polyethylene; and

[0059] 1.5~2 parts of additives.

[0060] In some of the examples, in the polyethylene composite material, the density of the first polyethylene is 0.955 g / cm 3 ~0.96g / cm 3 .

[0061] It is understood that the density of the first polyethylene includes but is not limited to 0.955 g / cm 3 , 0.958 g / cm 3 , 0.96 g / cm 3 .

[0062] In some of the examples, in the polyethylene composite material, the density of the second polyethylene is 0.92 g / cm 3 ~0.93g / cm 3 .

[0063] It is understood that the density of the second polyethylene includes but is not limited to 0.92 g / cm 3 , 0.922 g / cm 3 , 0.925 g / cm 3 , 0.928 g / cm 3 , 0.93 g / cm 3 .

[0064] In some of the examples, the density of the third polyethylene in the polyethylene composite is 0.945 g / cm 3~0.95g / cm 3 .

[0065] It is understood that the density of the third polyethylene includes but is not limited to 0.945 g / cm 3 , 0.948 g / cm 3 , 0.95 g / cm 3 .

[0066] In some of the examples, in the polyethylene composite material, the melt index of the first polyethylene at 2.16 kg and 190° C. is 1 g / 10 min to 3 g / 10 min.

[0067] It can be understood that the melt index of the first polyethylene at 2.16 kg and 190°C includes but is not limited to 1 g / 10min, 1.2 g / 10min, 1.5 g / 10min, 1.8 g / 10min, 2g / 10min, 2.2 g / 10min, 2.5 g / 10min, 2.8 g / 10min, and 3 g / 10min.

[0068] In some of the examples, in the polyethylene composite material, the melt index of the second polyethylene at 2.16 kg and 190° C. is 2 g / 10 min to 3 g / 10 min.

[0069] It can be understood that the melt index of the second polyethylene at 2.16 kg and 190° C. includes but is not limited to 2 g / 10 min, 2.2 g / 10 min, 2.5 g / 10 min, 2.8 g / 10 min, and 3 g / 10 min.

[0070] In some of the examples, in the polyethylene composite material, the melt index of the third polyethylene at 21.6 kg and 190° C. is 0.3 g / 10 min to 0.5 g / 10 min.

[0071] It can be understood that the melt index of the third polyethylene at 21.6 kg and 190°C includes but is not limited to 0.3 g / 10 min, 0.32 g / 10 min, 0.35 g / 10 min, 0.38 g / 10 min, 0.4 g / 10 min, 0.42 g / 10 min, 0.45 g / 10 min, 0.48 g / 10 min, and 0.5 g / 10 min.

[0072] In some of the examples, in the polyethylene composite material, the additive includes at least one of an antioxidant additive, a light stabilizer additive, and a lubricating additive.

[0073] In some of the examples, in the polyethylene composite material, in the raw materials for preparing the polyethylene composite material, the additives include 0.3 to 0.5 parts of antioxidant additives, 0.3 to 0.5 parts of light stabilizing additives and 0.3 to 1 parts of lubricating additives, calculated by weight.

[0074] It can be understood that in the raw materials for preparing polyethylene composite materials, the weight parts of additives include but are not limited to 0.3 parts, 0.4 parts, and 0.5 parts; the weight parts of light stabilizing additives include but are not limited to 0.3 parts, 0.4 parts, and 0.5 parts; the weight parts of lubricating additives include but are not limited to 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, and 1 part.

[0075] It can be further understood that, in parts by weight, the raw materials for preparing the polyethylene composite material include:

[0076] 60 to 70 parts of the first polyethylene;

[0077] 10 to 20 parts of the second polyethylene;

[0078] 10 to 20 parts of the third polyethylene;

[0079] 0.3~0.5 parts of antioxidant additives;

[0080] 0.3 to 0.5 parts of light stabilizer; and

[0081] Lubricating agent: 0.3~1 part.

[0082] In some of the examples, in the polyethylene composite material, the raw materials for preparing the polyethylene composite material include, by weight:

[0083] 60 to 65 parts of the first polyethylene;

[0084] 16 to 20 parts of the second polyethylene;

[0085] 17 to 20 parts of the third polyethylene;

[0086] 0.4~0.5 parts of antioxidant additives;

[0087] 0.4 to 0.5 parts of light stabilizing agent; and

[0088] Lubricating agent 0.7~1 part.

[0089] In some examples, in the polyethylene composite material, the antioxidant comprises at least one of hindered phenols, phosphites and thioesters, such as at least one of antioxidants 1010 and 168.

[0090] In some examples, in the polyethylene composite material, the light stabilizing agent includes at least one of a hindered amine and an ultraviolet absorber, such as UV-5590.

[0091] In some of these examples, in polyethylene composites, the lubricating aid includes a metal soap lubricant, such as CaSt.

[0092] An embodiment of the present application provides a method for preparing a polyethylene composite material, comprising the following steps:

[0093] In parts by weight, 60 to 70 parts of a first polyethylene, 10 to 20 parts of a second polyethylene, 10 to 20 parts of a third polyethylene and 0.9 to 2 parts of an additive are melt-blended and extruded and granulated in sequence to prepare a polyethylene composite material; wherein the viscosity average molecular weight of the first polyethylene is 200,000 to 300,000, the viscosity average molecular weight of the second polyethylene is 25,000 to 35,000, and the viscosity average molecular weight of the third polyethylene is 600,000 to 1,000,000.

[0094] In some of the examples, in the method for preparing the polyethylene composite material, the temperature of melt blending is 25° C. to 35° C. It can be understood that the melt blending is performed at room temperature.

[0095] In some of the examples, in the method for preparing the polyethylene composite material, the rotation speed of the melt blending is 350 rpm to 400 rpm. It is understood that rpm refers to revolutions per minute; further, the rotation speed of the melt blending includes but is not limited to 350 rpm, 360 rpm, 370 rpm, 380 rpm, 390 rpm, and 400 rpm.

[0096] In some of the examples, in the method for preparing the polyethylene composite material, the melt blending time is 10 min to 15 min. It is understood that the melt blending time includes but is not limited to 10 min, 11 min, 12 min, 13 min, 14 min, and 15 min.

[0097] In some of the examples, in the method for preparing the polyethylene composite material, the temperature of extrusion granulation is 190° C. to 210° C. It is understood that the temperature of extrusion granulation includes but is not limited to 190° C., 200° C., 205° C., and 210° C.

[0098] In some of the examples, in the method for preparing the polyethylene composite material, the screw speed of the extrusion granulation is 300 rpm to 400 rpm. It is understood that rpm refers to revolutions per minute; further, the speed of the melt blending includes but is not limited to 300 rpm, 310 rpm, 320 rpm, 330 rpm, 350 rpm, 360 rpm, 370 rpm, 380 rpm, 390 rpm, and 400 rpm.

[0099] One embodiment of the present application provides the use of the polyethylene composite material or the polyethylene composite material prepared by the above preparation method in the preparation of polyethylene products. Another embodiment of the present application provides a polyethylene product, including the polyethylene composite material or the polyethylene composite material prepared by the above preparation method.

[0100] The above-mentioned polyethylene composite material or the polyethylene composite material prepared by the above-mentioned preparation method is used to prepare polyethylene products, which can give the polyethylene products higher environmental stress cracking resistance, especially environmental stress cracking resistance to surfactants such as alcohol, soap, and detergent.

[0101] In some embodiments, the polyethylene products include but are not limited to oil tanks, oil drums, food packaging, and other container shells.

[0102] The present application is further described in detail below in conjunction with specific implementation methods, but the implementation methods of the present application are not limited thereto.

[0103] Example 1

[0104] In parts by weight, the raw materials include: 70 parts of the first polyethylene, 10 parts of the second polyethylene, 18 parts of the third polyethylene, 0.5 parts of antioxidant, 0.5 parts of light stabilizer and 1 part of lubricating agent; wherein the viscosity average molecular weight of the first polyethylene is 250,000, the viscosity average molecular weight of the second polyethylene is 30,000, and the viscosity average molecular weight of the third polyethylene is 800,000; the density of the first polyethylene is 0.96 g / cm 3 , the density of the second polyethylene is 0.92 g / cm 3 , the density of the third polyethylene is 0.95 g / cm 3 The melting index of the first polyethylene at 2.16kg and 190°C is 2g / 10min, the melting index of the second polyethylene at 2.16kg and 190°C is 3g / 10min, and the melting index of the third polyethylene at 21.6kg and 190°C is 0.5g / 10min; the antioxidant additive is 1010, the light stabilizing additive is UV-5590, and the lubricating additive is CaSt.

[0105] The first polyethylene, the second polyethylene, the third polyethylene, the antioxidant, the light stabilizer and the lubricating agent were melt-blended and then extruded and granulated to prepare a polyethylene composite material; the melt-blending temperature was room temperature, the rotation speed was 400 rpm, and the time was 10 min; the extrusion granulation temperature was 205°C, and the screw speed was 350 rpm.

[0106] Examples 2 to 8 are basically the same as Example 1, except that the number of components of the raw materials used in the preparation is different, as shown in Table 1. Taking Example 2 as an example, the raw materials used in the preparation of Example 2 are as follows:

[0107] In parts by weight, the prepared raw materials include: 70 parts of a first polyethylene, 15 parts of a second polyethylene, 13 parts of a third polyethylene, 0.5 parts of an antioxidant, 0.5 parts of a light stabilizing agent and 1 part of a lubricating agent.

[0108] Comparative Example 1

[0109] It is basically the same as Example 1, except that the second polyethylene and the third polyethylene are omitted, and the weight proportion of the first polyethylene is 98 parts.

[0110] Comparative Example 2

[0111] It is basically the same as Example 1, except that the third polyethylene is omitted, the weight proportion of the first polyethylene is 78 parts, and the weight proportion of the second polyethylene is 20 parts.

[0112] Comparative Example 3

[0113] It is basically the same as Example 1, except that the second polyethylene is omitted, the weight proportion of the first polyethylene is 78 parts, and the weight proportion of the third polyethylene is 20 parts.

[0114] Comparative Example 4

[0115] The method is basically the same as Example 1, except that the number of components of the raw materials used is different, as follows:

[0116] 78 parts of the first polyethylene, 10 parts of the second polyethylene, 10 parts of the third polyethylene, 0.5 parts of an antioxidant, 0.5 parts of a light stabilizer and 1 part of a lubricating agent.

[0117] Comparative Example 5

[0118] The same as Example 5, except that the first polyethylene is replaced by an equal weight portion of the fourth polyethylene, the viscosity average molecular weight of the fourth polyethylene is 400,000, and the density of the fourth polyethylene is 0.96 g / cm 3 The melt index of the fourth polyethylene at 2.16 kg and 190° C. is 0.5 g / 10 min.

[0119] The raw materials and the proportions of the polyethylene composite materials of the embodiments and comparative examples are shown in Table 1.

[0120] Table 1

[0121]

[0122] The polyethylene composite materials prepared in each embodiment and comparative example were tested for notched impact strength (ISO 179), tensile strength (ISO 527), environmental stress cracking resistance (ASTM 1693), and melt index (ISO 1133). The results are shown in Table 2.

[0123] Table 2

[0124]

[0125] It can be seen from Table 2 that, compared with Comparative Examples 1 to 4, the polyethylene composite materials prepared in each embodiment have better environmental stress cracking resistance, better fluidity and better processing performance on the basis of ensuring higher notched impact strength and tensile strength; while Comparative Example 5 has better environmental stress cracking resistance, but poor fluidity, and cannot take into account both environmental stress cracking resistance and processing performance.

[0126] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0127] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A polyethylene composite material, characterized in that: In parts by weight, the raw materials for preparing the polyethylene composite material include: 60 to 70 parts of the first polyethylene; 10 to 20 parts of the second polyethylene; 10 to 20 parts of the third polyethylene; and Additives 0.9~2 parts; The viscosity average molecular weight of the first polyethylene is 200,000 to 300,000, the viscosity average molecular weight of the second polyethylene is 25,000 to 35,000, and the viscosity average molecular weight of the third polyethylene is 600,000 to 1,000,000.

2. The polyethylene composite material according to claim 1, characterized in that: The density of the first polyethylene is 0.955 g / cm 3 ~0.96 g / cm 3 .

3. The polyethylene composite material according to claim 1, characterized in that: The density of the second polyethylene is 0.92 g / cm 3 ~0.93 g / cm 3 .

4. The polyethylene composite material according to claim 1, characterized in that: The density of the third polyethylene is 0.945 g / cm 3 ~0.95 g / cm 3 .

5. The polyethylene composite material according to claim 1, characterized in that: The first polyethylene has a melt index of 1 g / 10 min to 3 g / 10 min at 2.16 kg and 190° C.; and / or The melt index of the second polyethylene at 2.16 kg and 190° C. is 2 g / 10 min to 3 g / 10 min; and / or The third polyethylene has a melt index of 0.3 g / 10 min to 0.5 g / 10 min at 21.6 kg and 190° C.

6. The polyethylene composite material according to any one of claims 1 to 5, characterized in that The auxiliary agent includes at least one of an antioxidant auxiliary agent, a light stabilizing auxiliary agent and a lubricating auxiliary agent.

7. The polyethylene composite material according to claim 6, characterized in that: In the raw materials for preparing the polyethylene composite material, the additives include 0.3 to 0.5 parts of antioxidant additives, 0.3 to 0.5 parts of light stabilizing additives and 0.3 to 1 parts of lubricating additives, by weight.

8. The polyethylene composite material according to claim 7, characterized in that: The antioxidant auxiliary agent includes at least one of hindered phenols, phosphites and thioesters; and / or The light stabilizing agent includes at least one of hindered amines and ultraviolet absorbers; and / or The lubricating aid includes a metal soap lubricant.

9. A method for preparing a polyethylene composite material, characterized in that: The following steps are involved: In parts by weight, 60 to 70 parts of a first polyethylene, 10 to 20 parts of a second polyethylene, 10 to 20 parts of a third polyethylene and 0.9 to 2 parts of an additive are melt-blended and extruded and granulated in sequence to prepare a polyethylene composite material; wherein the viscosity average molecular weight of the first polyethylene is 200,000 to 300,000, the viscosity average molecular weight of the second polyethylene is 25,000 to 35,000, and the viscosity average molecular weight of the third polyethylene is 600,000 to 1,000,000.

10. A polyethylene product, characterized in that: The invention comprises the polyethylene composite material as described in any one of claims 1 to 8 or the polyethylene composite material prepared by the preparation method as described in claim 9.

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