Scratch-resistant composite polyethylene heat-seal film, method of manufacture and packaging material

Abstract

The application belongs to the field of composite polyethylene heat-seal film, and particularly relates to a scratch-resistant composite polyethylene heat-seal film, a preparation method and packaging material. The scratch-resistant composite polyethylene heat-seal film comprises a first composite layer, a second composite layer and a third composite layer in sequence. The raw material of the first composite layer is composed of low-density polyethylene and linear low-density polyethylene. The raw material of the second composite layer is composed of low-density polyethylene and high-density polyethylene. The raw material of the third composite layer is composed of high-density polyethylene, a composite metal ion polymer and a slip agent. The raw material of the composite metal ion polymer comprises DuPont Surlyn resin, a metal oxide, 2-acrylamide-2-methylpropanesulfonic acid and acryloyloxyethyl trimethylammonium chloride. The scratch-resistant composite polyethylene heat-seal film provided by the application can maintain excellent scratch resistance while overcoming the problems of environmental pollution and heat-seal difficulty caused by the large amount of fluorine-containing additives in the conventional technology.

Description

Technical Field

[0001] This application belongs to the field of composite polyethylene heat-sealing film, specifically relating to a scratch-resistant composite polyethylene heat-sealing film, its preparation method, and packaging material. Background Technology

[0002] With continuous innovation and progress in science and technology, the manufacturing industry has ushered in an unprecedented period of vigorous development and prosperity. In this rapid development process, the various industrial products produced by the manufacturing industry have not only become increasingly diverse in variety, but have also achieved significant improvements in precision and quality. These high-precision industrial products have placed more stringent and demanding requirements on packaging technology, making industrial product packaging a crucial technological industry whose importance is self-evident.

[0003] Composite polyethylene heat-sealable film, as a widely used and favored packaging material, is extensively applied in product packaging across various industries due to its excellent performance and practicality. Its presence can be seen in food, pharmaceuticals, electronics, and many other fields. However, despite its important role in the packaging field, composite polyethylene heat-sealable film still faces some insurmountable technical challenges in practical applications. For example, this film performs poorly in scratch resistance, easily generating debris during transportation and handling due to friction. Once this debris falls off, it can potentially contaminate the packaged product, affecting its quality and safety, causing unnecessary trouble and losses for businesses and consumers. Therefore, effectively solving this problem and improving the performance of composite polyethylene heat-sealable film has become a pressing technical challenge for the packaging industry.

[0004] Therefore, it is particularly important to develop a scratch-resistant composite polyethylene heat-sealing film to solve the problems existing in current traditional technologies. Summary of the Invention

[0005] The purpose of this application is to address the shortcomings of existing technologies and provide a scratch-resistant composite polyethylene heat-sealing film, its preparation method, and packaging material, specifically adopting the following technical solution:

[0006] First, this application provides a scratch-resistant composite polyethylene heat-sealing film, the structure of which includes, in sequence:

[0007] First composite layer, second composite layer and third composite layer;

[0008] By weight percentage, the first composite layer comprises 30%-50% low-density polyethylene and 50%-70% linear low-density polyethylene; the second composite layer comprises 10%-30% low-density polyethylene and 70%-90% high-density polyethylene; the third composite layer comprises 50%-70% high-density polyethylene, 30%-50% composite metal ion polymer, and 1%-2% slip agent; the density of high-density polyethylene is 0.936 g / cm³. 3 -0.972g / cm 3 The melt flow index is 0.5 g / 10 min - 0.7 g / 10 min;

[0009] The raw materials for the composite metal ion polymer include: DuPont Surlyn resin, metal oxides, 2-acrylamide-2-methylpropanesulfonic acid, and acryloyloxyethyltrimethylammonium chloride.

[0010] In the technical solution provided in this application, a first composite layer, a second composite layer, and a third composite layer are constructed by using specific raw materials in specific proportions. The first composite layer comprises a specific ratio of low-density polyethylene and linear low-density polyethylene. This combination gives the first composite layer excellent thermal adhesion and anti-fouling properties, as well as excellent toughness. Therefore, as the outermost layer in the structure composed of the first, second, and third composite layers, it provides strong protection in contact with the external environment, preventing damage to the scratch-resistant composite polyethylene heat-sealing film provided in this application. The second composite layer is composed of a specific content of low-density polyethylene and a specific content of high-density polyethylene, which makes the second composite layer... The first composite layer not only provides excellent barrier properties and film strength, but also works in conjunction with the third composite layer to ensure dimensional stability of the third and first composite layers at different temperatures. This avoids the deformation problem caused by inconsistent shrinkage of different layers in the scratch-resistant composite polyethylene heat-sealing film provided in this application at different temperatures. The third composite layer, as the layer that directly contacts the packaged object in the scratch-resistant composite polyethylene heat-sealing film provided in this application, achieves excellent scratch resistance through the combination of specific proportions of raw materials in a specific composition. Moreover, it avoids the problem of traditional technical solutions where adding a large amount of fluorine-containing components to increase scratch resistance leads to a decrease in heat-sealing performance and is not environmentally friendly. This approach improves performance while avoiding environmental pollution.

[0011] In some specific implementations, the mass ratio of DuPont Surlyn resin, metal oxide, 2-acrylamide-2-methylpropanesulfonic acid and acryloyloxyethyltrimethylammonium chloride is (67-81):(1-7):(12-15):(9-14).

[0012] In the technical solution provided in this application, DuPont Surlyn resin is a commonly used additive in the raw materials of composite metal ion polymers, but its performance is limited and cannot meet the requirements of the technical solution provided in this application. Therefore, further development has been carried out on the basis of existing DuPont Surlyn resin, so that when it is added to the third composite layer, it can work synergistically with other components to further improve the performance of the composite solution provided in this application.

[0013] In some specific implementations, the mass ratio of DuPont Surlyn resin, metal oxide, 2-acrylamide-2-methylpropanesulfonic acid and acryloyloxyethyltrimethylammonium chloride is (75-78):(4-6):13:(10-12).

[0014] In the above formula, certain ingredients, when in specific proportions, can produce superior technical effects and deliver better performance.

[0015] In some specific implementations, the preparation method of the composite metal ion polymer includes the following process: mixing DuPont Surlyn resin, metal oxide, 2-acrylamide-2-methylpropanesulfonic acid and acryloyloxyethyltrimethylammonium chloride, and kneading modification at 165℃-195℃.

[0016] In this application, a relatively reliable example is provided for the preparation method of the aforementioned metal ion polymer, which enables simple, efficient, and rapid synthesis, and its performance meets the expected technical effects of this application.

[0017] In some specific implementations, the metal oxide includes at least one of zinc oxide, titanium oxide, and aluminum oxide.

[0018] In particular, this application provides specific technical solutions under specific embodiments of metal oxides, such as zinc oxide, titanium oxide and aluminum oxide, which enable the technical solutions provided by this application to have superior technical effects and bring excellent performance.

[0019] In some specific implementation scenarios, the density of linear low-density polyethylene is 0.90 g / cm³. 3 -0.93g / cm 3 The density of low-density polyethylene is 0.90 g / cm³. 3 -0.92g / cm 3 .

[0020] By combining linear low-density polyethylene and low-density polyethylene of a specific density, the performance of the scratch-resistant composite polyethylene heat-sealing film provided in this application can be improved.

[0021] In some specific implementation scenarios, this application also provides specific proportions for the superior first composite layer, second composite layer, and third composite layer. By mass percentage, the raw materials for the first composite layer include 46% low-density polyethylene and 54% linear low-density polyethylene; the raw materials for the second composite layer include 13% low-density polyethylene and 87% high-density polyethylene; and the raw materials for the third composite layer include 57.5% high-density polyethylene, 41% composite metal ion polymer, and 1.5% slip agent.

[0022] Secondly, this application also provides a method for preparing the above-mentioned scratch-resistant composite polyethylene heat-sealing film, comprising the following steps: mixing the raw materials of the first composite layer, the second composite layer, and the third composite layer uniformly according to a certain ratio, and then sequentially extruding, blowing, cooling and shaping, and winding. The method for preparing the above-mentioned scratch-resistant composite polyethylene heat-sealing film provided by this application is relatively simple, has good winding effect, and is convenient for practical applications.

[0023] Finally, this application also provides a packaging material comprising the aforementioned scratch-resistant composite polyethylene heat-sealing film. The scratch-resistant composite polyethylene heat-sealing film provided in this application has broad application prospects in specific packaging materials. In some specific packaging material products, it can be covered with other materials to change the color and enhance the visual effect, and it can also be used in conjunction with other media.

[0024] The beneficial effects of this application are as follows: The first composite layer, the second composite layer, and the third composite layer prepared by this application using specific raw materials in a specific ratio work together to bring about excellent scratch resistance. Moreover, the metal ion polymer composed of DuPont Surlyn resin, metal oxide, 2-acrylamide-2-methylpropanesulfonic acid, and acryloyloxyethyltrimethylammonium chloride is used as an additive, which enables the third composite layer to have excellent scratch resistance while ensuring excellent adhesion. At the same time, it avoids other problems such as environmental impact caused by fluorinated compounds in traditional technologies. Detailed Implementation

[0025] The following will provide a clear and complete description of the concept and technical effects of this application in conjunction with embodiments, so as to fully understand the purpose, solution and effects of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0026] Example 1

[0027] First, this embodiment provides a scratch-resistant composite polyethylene heat-sealable film, which consists of three layers: a first composite layer, a second composite layer, and a third composite layer. In this embodiment, by mass percentage, the first composite layer contains 46% low-density polyethylene and 54% linear low-density polyethylene; the second composite layer contains 13% low-density polyethylene and 87% high-density polyethylene; and the third composite layer contains 57.5% high-density polyethylene, 41% composite metal ion polymer, and 1.5% slip agent. The density of the high-density polyethylene used is 0.942 g / cm³. 3 The melt flow index is 0.6 g / 10 min; the density of linear low-density polyethylene is 0.912 g / cm³. 3 The density of low-density polyethylene is 0.915 g / cm³. 3 .

[0028] The specific preparation method of the composite metal ion polymer includes the following process: by mass, 77 parts of DuPont Surlyn resin, 1 part of zinc oxide, 3 parts of aluminum oxide, 13 parts of 2-acrylamide-2-methylpropanesulfonic acid and 12 parts of acryloyloxyethyltrimethylammonium chloride are added to a kneader and kneaded at 175°C to obtain the metal ion polymer.

[0029] In this embodiment, the specific preparation method of the scratch-resistant composite polyethylene heat-sealing film includes the following steps: by weight, 3 parts by weight of the raw material of the first composite layer, 5 parts by weight of the raw material of the second composite layer, and 3 parts by weight of the raw material of the third composite layer are mixed evenly by a mixer, and then extruded, blown, cooled and shaped, and wound up by an extruder in sequence to obtain the finished scratch-resistant composite polyethylene heat-sealing film.

[0030] The scratch-resistant composite polyethylene heat-sealing film obtained in this embodiment was subjected to a scratch resistance test. The specific method was as follows: a 5kg metal rod with a spherical metal head was taken, and the scratch-resistant composite polyethylene heat-sealing film provided in this embodiment was wrapped around the spherical metal head, so that the third composite layer was exposed on the outermost side. Then, it was brought into contact with a horizontally placed metal plate, and the film was rubbed back and forth with the metal rod at a uniform speed until powder was produced. The degree of wear resistance was evaluated by the number of times this was performed. The scratch-resistant composite polyethylene heat-sealing film provided in this embodiment produced powder after 35 rubs.

[0031] Example 2

[0032] First, this embodiment provides a scratch-resistant composite polyethylene heat-sealable film, which consists of three layers: a first composite layer, a second composite layer, and a third composite layer. In this embodiment, by weight percentage, the first composite layer contains 46% low-density polyethylene and 54% linear low-density polyethylene; the second composite layer contains 13% low-density polyethylene and 87% high-density polyethylene; and the third composite layer contains 49.5% high-density polyethylene, 49% composite metal ion polymer, and 1.5% slip agent. The density of the high-density polyethylene used is 0.942 g / cm³. 3 The melt flow index is 0.6 g / 10 min; the density of linear low-density polyethylene is 0.912 g / cm³. 3 The density of low-density polyethylene is 0.915 g / cm³. 3 .

[0033] The specific preparation method of the composite metal ion polymer includes the following process: by mass, 77 parts of DuPont Surlyn resin, 1 part of zinc oxide, 3 parts of aluminum oxide, 13 parts of 2-acrylamide-2-methylpropanesulfonic acid and 12 parts of acryloyloxyethyltrimethylammonium chloride are added to a kneader and kneaded at 175°C to obtain the metal ion polymer.

[0034] In this embodiment, the specific preparation method of the scratch-resistant composite polyethylene heat-sealing film includes the following steps: by weight, 3 parts by weight of the raw material of the first composite layer, 5 parts by weight of the raw material of the second composite layer, and 3 parts by weight of the raw material of the third composite layer are mixed evenly by a mixer, and then extruded, blown, cooled and shaped, and wound up in sequence by an extruder to obtain the finished scratch-resistant composite polyethylene heat-sealing film.

[0035] The scratch-resistant composite polyethylene heat-sealing film obtained in this embodiment was subjected to a scratch resistance test. The specific method was as follows: A 5kg metal rod with a spherical metal head was taken, and the scratch-resistant composite polyethylene heat-sealing film provided in this embodiment was wrapped around the spherical metal head, exposing the third composite layer on the outermost side. Then, it was brought into contact with a horizontally placed metal plate. The film was rubbed back and forth against the metal plate at a uniform speed until powder was produced. The degree of wear resistance was evaluated by the number of rubs. The scratch-resistant composite polyethylene heat-sealing film provided in this embodiment produced powder after 33 rubs.

[0036] Example 3

[0037] First, this embodiment provides a scratch-resistant composite polyethylene heat-sealable film, which consists of three layers: a first composite layer, a second composite layer, and a third composite layer. In this embodiment, by mass percentage, the first composite layer contains 46% low-density polyethylene and 54% linear low-density polyethylene; the second composite layer contains 13% low-density polyethylene and 87% high-density polyethylene; and the third composite layer contains 57.5% high-density polyethylene, 41% composite metal ion polymer, and 1.5% slip agent. The density of the high-density polyethylene used is 0.942 g / cm³. 3 The melt flow index is 0.6 g / 10 min; the density of linear low-density polyethylene is 0.912 g / cm³. 3 The density of low-density polyethylene is 0.915 g / cm³. 3 .

[0038] The specific preparation method of the composite metal ion polymer includes the following process: by mass, 81 parts of DuPont Surlyn resin, 3 parts of zinc oxide, 3 parts of aluminum oxide, 13 parts of 2-acrylamide-2-methylpropanesulfonic acid and 14 parts of acryloyloxyethyltrimethylammonium chloride are added to a kneader and kneaded at 175°C to obtain the metal ion polymer.

[0039] In this embodiment, the specific preparation method of the scratch-resistant composite polyethylene heat-sealing film includes the following steps: by weight, 3 parts by weight of the raw material of the first composite layer, 5 parts by weight of the raw material of the second composite layer, and 3 parts by weight of the raw material of the third composite layer are mixed evenly by a mixer, and then extruded, blown, cooled and shaped, and wound up in sequence by an extruder to obtain the finished scratch-resistant composite polyethylene heat-sealing film.

[0040] The scratch-resistant composite polyethylene heat-sealing film obtained in this embodiment was subjected to a scratch resistance test. The specific method was as follows: a 5kg metal rod with a spherical metal head was taken, and the scratch-resistant composite polyethylene heat-sealing film provided in this embodiment was wrapped around the spherical metal head, so that the third composite layer was exposed on the outermost side. Then, it was brought into contact with a horizontally placed metal plate, and the film was rubbed back and forth with the metal rod at a uniform speed until powder was produced. The degree of wear resistance was evaluated by the number of times this was performed. The scratch-resistant composite polyethylene heat-sealing film provided in this embodiment produced powder after 36 rubs.

[0041] Comparative Example 1

[0042] First, this comparative example provides a polyethylene heat-sealable film, which consists of three layers: a first composite layer, a second composite layer, and a third composite layer. In this comparative example, by mass percentage, the first composite layer contains 46% low-density polyethylene and 54% linear low-density polyethylene; the second composite layer contains 13% low-density polyethylene and 87% high-density polyethylene; and the third composite layer is made entirely of low-density polyethylene, with the high-density polyethylene having a density of 0.942 g / cm³. 3 The melt flow index is 0.6 g / 10 min; the density of linear low-density polyethylene is 0.912 g / cm³. 3 The density of low-density polyethylene is 0.915 g / cm³. 3 .

[0043] In this comparative example, the specific preparation method of the polyethylene heat-sealing film includes the following steps: by weight, 3 parts by weight of the raw material of the first composite layer, 5 parts by weight of the raw material of the second composite layer, and 3 parts by weight of the raw material of the third composite layer are mixed evenly by a mixer, and then extruded, blown, cooled and shaped, and wound up by an extruder in sequence to obtain the finished polyethylene heat-sealing film.

[0044] The scratch resistance of the polyethylene heat-sealing film obtained in this comparative example was tested. The specific method was as follows: a 5kg metal rod with a spherical metal head was taken, and the polyethylene heat-sealing film provided in this comparative example was wrapped around the spherical metal head, so that the third composite layer was exposed on the outermost side. Then it was brought into contact with a horizontally placed metal plate, and the film was rubbed back and forth with the metal rod at a uniform speed until powder was produced. The degree of wear resistance was evaluated by the number of times the film was rubbed. The polyethylene heat-sealing film provided in this comparative example produced powder after 7 rubs.

[0045] Comparative Example 2

[0046] First, this comparative example provides a polyethylene heat-sealable film, which consists of three layers: a first composite layer, a second composite layer, and a third composite layer. In this comparative example, by mass percentage, the first composite layer contains 46% low-density polyethylene and 54% linear low-density polyethylene; the second composite layer contains 13% low-density polyethylene and 87% high-density polyethylene; and the third composite layer contains 50% low-density polyethylene and 50% linear low-density polyethylene, with the high-density polyethylene used having a density of 0.942 g / cm³. 3 The melt flow index is 0.6 g / 10 min; the density of linear low-density polyethylene is 0.912 g / cm³. 3 The density of low-density polyethylene is 0.915 g / cm³. 3 .

[0047] In this comparative example, the specific preparation method of the polyethylene heat-sealing film includes the following steps: by weight, 3 parts by weight of the raw material of the first composite layer, 5 parts by weight of the raw material of the second composite layer, and 3 parts by weight of the raw material of the third composite layer are mixed evenly by a mixer, and then extruded, blown, cooled and shaped, and wound up by an extruder in sequence to obtain the finished polyethylene heat-sealing film.

[0048] The scratch resistance of the polyethylene heat-sealing film obtained in this comparative example was tested. The specific method was as follows: a 5kg metal rod with a spherical metal head was taken, and the polyethylene heat-sealing film provided in this comparative example was wrapped around the spherical metal head, so that the third composite layer was exposed on the outermost side. Then it was brought into contact with a horizontally placed metal plate, and the film was rubbed back and forth with the metal rod at a uniform speed until powder was produced. The degree of wear resistance was evaluated by the number of times the film was rubbed. The polyethylene heat-sealing film provided in this comparative example produced powder after 10 rubs.

[0049] Comparative Example 3

[0050] First, this comparative example provides a scratch-resistant composite polyethylene heat-sealable film, which consists of three layers: a first composite layer, a second composite layer, and a third composite layer. In this comparative example, by mass percentage, the first composite layer contains 46% low-density polyethylene and 54% linear low-density polyethylene; the second composite layer contains 13% low-density polyethylene and 87% high-density polyethylene; and the third composite layer contains 57.5% high-density polyethylene, 41% DuPont Surlyn resin, and 1.5% slip agent. The density of the high-density polyethylene used is 0.942 g / cm³. 3 The melt flow index is 0.6 g / 10 min; the density of linear low-density polyethylene is 0.912 g / cm³. 3 The density of low-density polyethylene is 0.915 g / cm³. 3 .

[0051] In this comparative example, the specific preparation method of the scratch-resistant composite polyethylene heat-sealing film includes the following steps: by weight, 3 parts by weight of the raw material of the first composite layer, 5 parts by weight of the raw material of the second composite layer, and 3 parts by weight of the raw material of the third composite layer are mixed evenly by a mixer, and then extruded, blown, cooled and shaped, and wound up in sequence by an extruder to obtain the finished scratch-resistant composite polyethylene heat-sealing film.

[0052] The scratch-resistant composite polyethylene heat-sealing film obtained in this comparative example was subjected to a scratch resistance test. The specific method was as follows: a 5kg metal rod with a spherical metal head was taken, and the scratch-resistant composite polyethylene heat-sealing film provided in this comparative example was wrapped around the spherical metal head, so that the third composite layer was exposed on the outermost side. Then it was brought into contact with a horizontally placed metal plate, and the film was rubbed back and forth with the metal rod at a uniform speed until powder was produced. The degree of wear resistance was evaluated by the number of times the film was rubbed. The scratch-resistant composite polyethylene heat-sealing film provided in this comparative example produced powder after 21 rubs.

[0053] Comparative Example 4

[0054] First, this comparative example provides a scratch-resistant composite polyethylene heat-sealing film, which consists of three layers: a first composite layer, a second composite layer, and a third composite layer. In this comparative example, by mass percentage, the first composite layer contains 46% low-density polyethylene and 54% linear low-density polyethylene; the second composite layer contains 13% low-density polyethylene and 87% high-density polyethylene; and the third composite layer contains 57.5% high-density polyethylene, 41% composite metal ion polymer, and 1.5% slip agent. The density of the high-density polyethylene used is 0.942 g / cm³. 3 The melt flow index is 0.6 g / 10 min; the density of linear low-density polyethylene is 0.912 g / cm³. 3 The density of low-density polyethylene is 0.915 g / cm³. 3 .

[0055] The specific preparation method of the composite metal ion polymer includes the following process: by mass, 150 parts of DuPont Surlyn resin, 1 part of zinc oxide, 3 parts of aluminum oxide, 13 parts of 2-acrylamide-2-methylpropanesulfonic acid and 12 parts of acryloyloxyethyltrimethylammonium chloride are added to a kneader and kneaded at 175°C to obtain the metal ion polymer.

[0056] In this comparative example, the specific preparation method of the scratch-resistant composite polyethylene heat-sealing film includes the following steps: by weight, 3 parts by weight of the raw material of the first composite layer, 5 parts by weight of the raw material of the second composite layer, and 3 parts by weight of the raw material of the third composite layer are mixed evenly by a mixer, and then extruded, blown, cooled and shaped, and wound up in sequence by an extruder to obtain the finished scratch-resistant composite polyethylene heat-sealing film.

[0057] The scratch-resistant composite polyethylene heat-sealing film obtained in this comparative example was subjected to a scratch resistance test. The specific method was as follows: a 5kg metal rod with a spherical metal head was taken, and the scratch-resistant composite polyethylene heat-sealing film provided in this comparative example was wrapped around the spherical metal head, so that the third composite layer was exposed on the outermost side. Then, it was brought into contact with a horizontally placed metal plate, and the film was rubbed back and forth with the metal rod at a uniform speed until powder was produced. The degree of wear resistance was evaluated by the number of times the film was rubbed. The scratch-resistant composite polyethylene heat-sealing film provided in this comparative example produced powder after 29 rubs.

[0058] It is evident from the above embodiments and comparative examples that the scratch-resistant composite polyethylene heat-sealing film provided in this application possesses excellent scratch resistance.

[0059] Although the description of this application has been quite detailed and particularly focused on several of the described embodiments, it is not intended to limit itself to any of these details or embodiments or any particular embodiment. Rather, it should be considered as providing a broad possible interpretation of the claims by referring to the appended claims and taking into account the prior art, thereby effectively covering the intended scope of this application. Furthermore, the foregoing description of this application with respect to embodiments foreseeable by the applicant is intended to provide a useful description, and non-substantial modifications to this application that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A scratch-resistant composite polyethylene heat-sealable film, characterized in that, In order, they include: First composite layer, second composite layer and third composite layer; By weight percentage, the raw materials of the first composite layer include 30%-50% low-density polyethylene and 50%-70% linear low-density polyethylene; the raw materials of the second composite layer include 10%-30% low-density polyethylene and 70%-90% high-density polyethylene; the raw materials of the third composite layer include 48%-70% high-density polyethylene, 28%-50% composite metal ion polymer, and 1%-2% slip agent; the density of the high-density polyethylene is 0.936 g / cm³. 3 -0.972g / cm 3 The melt flow index is 0.5 g / 10 min - 0.7 g / 10 min; The raw materials for the composite metal ion polymer include: DuPont Surlyn resin, metal oxide, 2-acrylamide-2-methylpropanesulfonic acid, and acryloyloxyethyltrimethylammonium chloride; The mass ratio of the DuPont Surlyn resin, the metal oxide, the 2-acrylamide-2-methylpropanesulfonic acid and the acryloyloxyethyltrimethylammonium chloride is (67-81):(1-7):(12-15):(9-14). The preparation method of the composite metal ion polymer includes the following process: mixing the DuPont Surlyn resin, the metal oxide, the 2-acrylamide-2-methylpropanesulfonic acid and the acryloyloxyethyltrimethylammonium chloride, and kneading modification at 165℃-195℃. The metal oxide includes at least one of zinc oxide, titanium oxide, and aluminum oxide.

2. The scratch-resistant composite polyethylene heat-sealable film according to claim 1, characterized in that, The mass ratio of the DuPont Surlyn resin, the metal oxide, the 2-acrylamide-2-methylpropanesulfonic acid and the acryloyloxyethyltrimethylammonium chloride is (75-78):(4-6):13:(10-12).

3. The scratch-resistant composite polyethylene heat-sealable film according to claim 1, characterized in that, The linear low-density polyethylene has a density of 0.90 g / cm³. 3 -0.93g / cm 3 .

4. The scratch-resistant composite polyethylene heat-sealable film according to claim 1, characterized in that, The density of the low-density polyethylene is 0.90 g / cm³. 3 -0.92g / cm 3 .

5. The scratch-resistant composite polyethylene heat-sealable film according to claim 1, characterized in that, By weight percentage, the raw materials of the first composite layer include 46% low-density polyethylene and 54% linear low-density polyethylene; the raw materials of the second composite layer include 13% low-density polyethylene and 87% high-density polyethylene; and the raw materials of the third composite layer include 57.5% high-density polyethylene, 41% composite metal ion polymer and 1.5% slip agent.

6. A method for preparing a scratch-resistant composite polyethylene heat-sealable film as described in any one of claims 1-5, characterized in that, Includes the following steps: The raw materials for the first composite layer, the second composite layer, and the third composite layer are mixed evenly according to the proportions, and then extruded, blown, cooled and shaped, and wound up in sequence.

7. A packaging material, characterized in that, The packaging material includes the scratch-resistant composite polyethylene heat-sealable film as described in any one of claims 1-5.