Matt material for BOPE matt film, and BOPE matt film and preparation method therefor

Abstract

The present invention belongs to the technical field of bidirectionally stretched polyethylene matt films, and relates to a matt material for a BOPE matt film, and a BOPE matt film and a preparation method therefor. The matt material comprises: a first component, a second component and an optional auxiliary, wherein the first component comprises a first polyethylene resin, a second polyethylene resin, and an optional cyclic olefin resin; the second component comprises a polypropylene resin and an optional nucleating agent; and the matt material comprises at least one of a cyclic olefin resin and a nucleating agent. The BOPE matt film prepared by using the matt material of the present invention has a high haze and a low gloss, and the entire thin film has a good matt uniformity.

Description

Matting agents for BOPE matte film and BOPE matte film and their preparation methods

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411578300.8, filed on November 6, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of biaxially oriented polyethylene (BOPE) matte film technology, and more specifically, to a matte material for BOPE matte film, a BOPE matte film, and a method for preparing the same. Background Technology

[0004] Biaxially oriented polyethylene (BOPE) film is obtained by simultaneously or asynchronously stretching polyethylene cast sheets in both the longitudinal and transverse directions. After stretching, the molecular chains and lamellar crystals of polyethylene are highly oriented along the stretching direction, giving BOPE film the characteristics of high tensile strength, good transparency, low-temperature resistance, puncture resistance, impact resistance, easy tearing, and very few pinhole defects. Therefore, it is widely used in agricultural greenhouse films, composite bag making, low-temperature packaging, and medical packaging.

[0005] BOPE film boasts excellent performance, significantly expanding the application areas of plastic films while aligning with the trends of lightweight and environmentally friendly packaging, thus possessing broad market prospects. However, the increasingly mature packaging market urgently needs functional BOPE films, with BOPE matte film being particularly favored and used as a high-value, premium packaging film. BOPE matte film is produced by adding BOPE matte material to the surface of a co-extruded film, followed by biaxial stretching, resulting in a roughened surface structure that diffuses light, thus achieving a matte (glossy) effect. Matte film on packaged products conveys a soft, stylish, and elegant high-end feel, while also reducing eye strain; therefore, the application of BOPE matte film in the packaging field is becoming increasingly widespread.

[0006] However, the production technology for matte materials and films used in BOPE matte films is not yet mature. Due to the complexity of the biaxial stretching process, matte-specific materials such as those for blown or cast PE films and BOPP films are difficult to apply to the production of BOPE matte films. Therefore, there is an urgent need to develop matching BOPE matte film materials based on BOPE film materials and their biaxial stretching process. In the prior art, CN110876264A discloses a biaxially oriented polyethylene multilayer film with a matte surface, which is prepared by directly extruding and casting a mixture of a certain proportion of polyethylene and polypropylene on a biaxial stretching machine. In this method, the matte layer raw materials are only extruded and mixed once in the entire process, which may result in uneven dispersion of polyethylene and polypropylene in the formulation, leading to poor matte effect. In addition, CN 111978625A discloses a matting material for BOPE matting film, its preparation method, and a BOPE matting film. This matting material for BOPE matting film includes copolymer polyethylene, polypropylene, masterbatch A, and masterbatch B. Masterbatch A includes a masterbatch matrix and hydrogenated petroleum resin. Masterbatch B includes a masterbatch matrix and PPA processing aid. The masterbatch matrix is ​​copolymer polyethylene. The BOPE matting film obtained by this invention has a maximum haze of 87.4% and a minimum gloss of 8.7%, resulting in a poor matting effect. Summary of the Invention

[0007] The purpose of this invention is to provide a matting agent for BOPE matting film, a BOPE matting film, and a method for preparing the same. The BOPE matting film prepared using the matting agent of this invention has high haze, low gloss, and good uniformity of matting throughout the film.

[0008] To achieve the above objectives, a first aspect of the present invention provides a matting agent for BOPE matting film, the matting agent comprising: a first component, a second component, and optional additives;

[0009] The first component comprises: a first polyethylene resin, a second polyethylene resin, and a cyclic olefin resin; the content of the cyclic olefin resin is 1-15 wt% based on the total weight of the first component.

[0010] The second component includes: polypropylene resin and optional nucleating agent.

[0011] A second aspect of the present invention provides a method for preparing the above-mentioned matting material for BOPE matte film, the method comprising: mixing a first component, a second component and optional additives, extruding, granulating and drying to obtain the matting material for BOPE matte film;

[0012] Preferably, the preparation method includes: mixing, extruding, granulating and drying the first component granules, the second component granules and optional additives to obtain the matting material for BOPE matting film.

[0013] A third aspect of the present invention provides a BOPE matte film, which comprises, in sequence, a first surface layer, an intermediate layer, and a second surface layer.

[0014] At least one of the first surface layer and the second surface layer is a matte layer;

[0015] The surface of the matting layer has a three-dimensional mesh structure, which includes fibers and hill-shaped protrusions.

[0016] A fourth aspect of the present invention provides a BOPE matte film, which is made from raw materials including the above-mentioned matte material for BOPE matte film;

[0017] The haze of the BOPE matte film is greater than 90%, and the absolute value of the difference between the haze values ​​of any two points per square meter of the BOPE matte film is less than 3%, preferably less than 1%.

[0018] The gloss of the BOPE matte film is less than 9.5%, and the absolute value of the difference between the gloss values ​​of any two points on each square meter of the BOPE matte film is less than 3.1%, preferably less than 0.5%.

[0019] The fifth aspect of the present invention provides a method for preparing the above-mentioned BOPE matte film, the method comprising:

[0020] The raw materials of each layer are co-extruded and cast to obtain a cast sheet; then the cast sheet is subjected to longitudinal stretching and preheating, longitudinal stretching, transverse stretching and preheating, transverse stretching and shaping in sequence to obtain the BOPE matte film.

[0021] The technical solution of the present invention has the following beneficial effects:

[0022] (1) The BOPE matte film prepared using the matte material of the present invention has high haze, low gloss, and good matte uniformity as a whole.

[0023] (2) The matting material of the present invention is not only simple to prepare, but also has excellent processing performance and good stretching and film-forming properties. Attached Figure Description

[0024] Figure 1 shows an atomic force microscope (AFM) image of the matting layer in the BOPE matting film of Example 2.

[0025] Figure 2 shows an atomic force microscope (AFM) image of the matting layer in the BOPE matting film of Example 5.

[0026] Figure 3 shows an atomic force microscope (AFM) image of the matting layer in the BOPE matting film of Comparative Example 1. Detailed Implementation

[0027] In this invention, unless otherwise specified, "first" and "second" do not indicate a sequence or limit the specific materials or steps; they are merely used to distinguish that these are not the same material or step. For example, in "first polyethylene resin" and "second polyethylene resin," "first" and "second" are used only to indicate that these are not the same polyethylene resin component.

[0028] A first aspect of the present invention provides a matting agent for BOPE matting film, the matting agent comprising: a first component, a second component, and optional additives;

[0029] The first component comprises: a first polyethylene resin, a second polyethylene resin, and a cyclic olefin resin; wherein, based on the total weight of the first component, the content of the cyclic olefin resin is 1-15 wt%.

[0030] The second component includes: polypropylene resin and optional nucleating agent.

[0031] In this invention, the inventors discovered through extensive research that adding component C (cyclic olefin resin) to the matting material for BOPE matting film enables the first and second components of the BOPE matting material to form a better phase separation interface, creating fiber and hill-like protrusion structures on the film surface. This ensures that the BOPE matting film has excellent matting performance. In addition, the addition of component C can better refine the bicontinuous phase structure formed by the first and second components, resulting in better in-situ fiberization and uniformity of film surface matting during subsequent stretching.

[0032] In this invention, the inventors discovered that when the content of cyclic olefin resin in the first component is within the aforementioned range, it can promote and regulate the phase separation of polyethylene and polypropylene, thereby forming a fibrous and hill-like protrusion structure on the film surface, ensuring that the matte film has high haze and low gloss. Specifically, when the content of cyclic olefin resin, based on the total weight of the first component, is less than 1 wt%, it cannot effectively promote and regulate the phase separation of polyethylene and polypropylene, and cannot form fibers and hill-like protrusions on the film surface, resulting in low haze, high gloss, and poor uniformity of the film; when the content of cyclic olefin resin, based on the total weight of the first component, exceeds 15 wt%, the matte layer breaks during the subsequent biaxial stretching process, making it difficult to achieve continuous and stable production of biaxially stretched matte films.

[0033] In this invention, the content of the cyclic olefin resin is 1-15 wt% based on the total weight of the first component, for example, it can be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, and any range of two values.

[0034] In a preferred embodiment of the present invention, the content of the cyclic olefin resin is 5-15 wt% based on the total weight of the first component.

[0035] According to the present invention, preferably, the content of the first component, based on the sum of the weights of the first component and the second component, is 30-70 wt%, for example, it can be 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, or any range of two values; the content of the second component is 30-70 wt%, for example, it can be 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, or any range of two values.

[0036] And / or, based on the sum of the weights of the first component and the second component, the content of the adjuvant is 0-0.8 wt%, for example, it can be 0 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, and any range of two values;

[0037] And / or, based on the total weight of the first component, the content of the first polyethylene resin is 10-30 wt%, for example, it can be 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt%, 30 wt%, or any two of these values; the content of the second polyethylene resin is 55-85 wt%, for example, it can be 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, or any two of these values; the content of the cyclic olefin resin is 1-15 wt%, for example, it can be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, or any two of these values.

[0038] And / or, based on the total weight of the second component, the content of the polypropylene resin is 99-100 wt%, for example, it can be 99 wt%, 99.1 wt%, 99.2 wt%, 99.3 wt%, 99.4 wt%, 99.5 wt%, 99.6 wt%, 99.7 wt%, 99.8 wt%, 99.9 wt%, 100 wt%, and any range of two values; the content of the nucleating agent is 0-1 wt%, for example, it can be 0 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, and any range of two values.

[0039] In this invention, the first component and the second component are preferably used in a suitable ratio so that the first component and the second component in the matting material for BOPE matting film can form a better bicontinuous phase structure, which can ensure that the BOPE matting film has better matting effect and matting uniformity after subsequent casting-biaxial stretching.

[0040] In a preferred embodiment of the present invention, preferably, the content of the first component is 40-60 wt% and the content of the second component is 40-60 wt% based on the sum of the weights of the first component and the second component.

[0041] And / or, the content of the auxiliary agent is 0.2-0.8 wt%, based on the sum of the weights of the first component and the second component;

[0042] And / or, based on the total weight of the first components, the content of the first polyethylene resin is 10-30 wt%, the content of the second polyethylene resin is 55-85 wt%, and the content of the cyclic olefin resin is 5-15 wt%.

[0043] And / or, based on the total weight of the second component, the content of the polypropylene resin is 99-99.9 wt%, and the content of the nucleating agent is 0.1-1 wt%.

[0044] In this invention, the inventors discovered that by adding a cyclic olefin resin to the first component and adding a specific amount of nucleating agent to the second component, the presence of the nucleating agent can further refine the spherulites of crystalline polypropylene, which is more conducive to the cyclic olefin resin promoting and regulating the phase separation of polyethylene and polypropylene. The two work synergistically to jointly regulate the surface structure of the film and further improve the extinction uniformity of the film.

[0045] According to the present invention, preferably, the melt index of the first polyethylene resin at 190°C and 2.16 kg is 0.5-2 g / 10 min, for example, it can be 0.5 g / 10 min, 0.6 g / 10 min, 0.7 g / 10 min, 0.8 g / 10 min, 0.9 g / 10 min, 1 g / 10 min, 1.1 g / 10 min, 1.2 g / 10 min, 1.3 g / 10 min, 1.4 g / 10 min, 1.5 g / 10 min, 1.6 g / 10 min, 1.7 g / 10 min, 1.8 g / 10 min, 1.9 g / 10 min, 2 g / 10 min, or any range of two values; the density of the first polyethylene resin is 0.916 g / cm³. 3 -0.924g / cm 3 For example, it can be 0.916 g / cm³ 3 0.917 g / cm 3 0.918 g / cm 3 0.919 g / cm 3 0.920 g / cm 3 0.921 g / cm 3 0.922 g / cm 3 0.923 g / cm 3 0.924 g / cm 3 , and the range consisting of any two values;

[0046] The melt flow index of the second polyethylene resin at 190°C and 2.16 kg is 20-70 g / 10 min, for example, it can be 20 g / 10 min, 22 g / 10 min, 24 g / 10 min, 26 g / 10 min, 28 g / 10 min, 30 g / 10 min, 32 g / 10 min, 34 g / 10 min, 36 g / 10 min, 38 g / 10 min, 40 g / 10 min, 42 g / 10 min, 44 g / 10min, 46g / 10min, 48g / 10min, 50g / 10min, 52g / 10min, 54g / 10min, 56g / 10min, 58g / 10min, 60g / 10min, 62g / 10min, 64g / 10min, 66g / 10min, 68g / 10min, 70g / 10min, and any range of two values; the density of the second polyethylene resin is 0.924g / cm³. 3 -0.930g / cm 3 For example, it can be 0.924 g / cm³. 3 0.925g / cm 3 0.926 g / cm 30.927 g / cm 3 0.928 g / cm 3 0.929 g / cm 3 0.930 g / cm 3 , and the range of any two values.

[0047] In this invention, the inventors discovered that by selecting two polyethylene resins with different densities and melt indices in the first component for compounding, the first polyethylene resin with low density and low melt index ensures sufficient physical entanglement points during the subsequent biaxial stretching process, ensuring a larger stretching ratio, thereby ensuring sufficient phase separation and improving matting performance; while the second polyethylene resin with high density and high melt index has sufficient melt fluidity, enabling the matting layer to pass uniformly through the casting die to form a uniform matting layer, thereby ensuring the uniformity of the subsequent matting film.

[0048] Furthermore, by selecting a first polyethylene resin with the aforementioned specific density and specific melt index, and a second polyethylene resin with the aforementioned specific density and specific melt index, it is possible to ensure that the matting material has good melt flowability while also ensuring that it can achieve a large biaxial stretching ratio in the subsequent biaxial stretching process, thereby improving the matting performance and uniformity of the matting film thus obtained.

[0049] In a preferred embodiment of the present invention, the melt index of the first polyethylene resin at 190°C and 2.16 kg is 0.5-2 g / 10 min; the density of the first polyethylene resin is 0.916-0.920 g / cm³. 3 ;

[0050] The melt flow index of the second polyethylene resin at 190℃ and 2.16 kg is 20-50 g / 10 min; the density of the second polyethylene resin is 0.924-0.928 g / cm³. 3 .

[0051] In this invention, there is no particular limitation on the types of the first polyethylene resin and the second polyethylene resin, as long as the density and melt flow index of the first polyethylene resin and the second polyethylene resin independently meet the requirements of this invention.

[0052] In one specific embodiment of the present invention, the first polyethylene resin is low-density polyethylene and / or linear low-density polyethylene.

[0053] In one specific embodiment of the present invention, the second polyethylene resin is low-density polyethylene and / or linear low-density polyethylene.

[0054] According to the present invention, preferably, the cyclic olefin resin is a cyclic olefin copolymer and / or a cyclic olefin homopolymer.

[0055] In this invention, the cyclic olefin homopolymer is a polymer obtained by hydrogenation of a single type of cyclic olefin monomer (such as norbornene and its derivatives) through ring-opening polymerization.

[0056] In this invention, the cyclic olefin copolymer is a polymer product obtained by catalytic copolymerization of cyclic olefins and olefin monomers.

[0057] In this invention, there is no particular limitation on the type of cyclic olefin resin, and all types can achieve the purpose of this invention.

[0058] According to the present invention, the glass transition temperature of the cyclic olefin resin is below 110°C.

[0059] In this invention, the inventors further discovered that the addition of cyclic olefin resin can improve the uniformity of the matte film because cyclic olefin polymers are amorphous polymers. When the glass transition temperature of the cyclic olefin resin is lower than the melting point of the BOPE resin raw material, the cyclic olefin resin can deform under biaxial stretching temperature without forming stress concentration points. This not only prevents the BOPE film from breaking but also makes the roughness more uniform, thereby optimizing the uniformity of the matte film.

[0060] According to the present invention, preferably, the polypropylene resin is homopolymer polypropylene and / or binary copolymer polypropylene.

[0061] According to the present invention, preferably, the density of the polypropylene resin is 0.89 g / cm³. 3 -0.91g / cm 3 For example, it can be 0.89 g / cm³. 3 0.9g / cm 3 0.91g / cm 3The melt index of the polypropylene resin at 230°C and 2.16 kg is 0.1-2 g / 10 min, and the range of any two values ​​is also specified. For example, it could be 0.1 g / 10 min, 0.2 g / 10 min, 0.3 g / 10 min, 0.4 g / 10 min, 0.5 g / 10 min, 0.6 g / 10 min, 0.7 g / 10 min, 0.8 g / 10 min, 0.9 g / 10 min, 1 g / 10 min, 1.1 g / 10 min, 1.2 g / 10 min, 1.3 g / 10 min, 1.4 g / 10 min, etc. The melting point of the polypropylene resin is greater than or equal to 160°C, for example, it can be 160°C, 161°C, 162°C, 163°C, 164°C, 165°C, 166°C, 167°C, 168°C, 169°C, 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C and above, and any range of two values.

[0062] In this invention, when the density, melt index, and melting point of the polypropylene resin meet the above-mentioned ranges, it can achieve a better phase separation effect with the first component, thereby enabling the film produced to achieve higher haze and lower gloss.

[0063] In a preferred embodiment of the present invention, preferably, the density of the polypropylene resin is 0.89-0.90 g / cm³. 3 The polypropylene resin has a melt index of 0.5-2 g / 10 min at 230℃ and 2.16 kg; the polypropylene resin has a melting point of 160-168℃.

[0064] According to the present invention, preferably, the binary copolymer polypropylene is ethylene-propylene copolymer polypropylene or propylene-butadiene copolymer polypropylene.

[0065] According to the present invention, preferably, the nucleating agent is at least one selected from sorbitol derivatives, organocarboxylic acid metal salts, amides, organophosphates, and organophosphates.

[0066] According to the present invention, preferably, the absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is less than 8.1°C, for example, it can be 8°C, 7°C, 6°C, 5°C, 4°C, 3°C, 2°C, 1°C, or 0°C.

[0067] In this invention, when the absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component meets the above-mentioned range, the nucleating agent can further enhance the refining effect on the crystalline polypropylene spherulites. Through subsequent biaxial stretching, the microstructure of the matting film surface can be further regulated, ensuring the matting performance and uniformity of the matting film.

[0068] In a preferred embodiment of the present invention, preferably, the absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is less than 5°C.

[0069] In one specific embodiment of the present invention, the melting point of the polypropylene resin (component A) in the second component is greater than or equal to 160°C, the second component contains a nucleating agent, the polypropylene resin is homopolymer polypropylene and / or binary copolymer polypropylene, and the absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is preferably less than 5°C.

[0070] In this invention, the melting point of component A (polypropylene resin) in the second component is greater than or equal to 160°C, and the absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is preferably less than 5°C, so that the surface of the matte film can be better fibroed in situ; the addition of the nucleating agent makes the crystal structure of the crystalline polypropylene more refined, thereby further reducing the diameter of the spherulites, further reducing the gloss of the BOPE matte film, and increasing the haze of the BOPE matte film.

[0071] In a preferred embodiment of the present invention, the polypropylene resin content is 99-99.9 wt% and the nucleating agent content is 0.1-1 wt% based on the total weight of the second component; the polypropylene resin has a melting point greater than or equal to 160°C, and the polypropylene resin is homopolymer polypropylene and / or binary copolymer polypropylene; preferably, the absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is less than 5°C. Using this preferred embodiment, the aspect ratio of the fibers in the three-dimensional network structure of the BOPE matte film surface can be further optimized and adjusted.

[0072] In this invention, unless otherwise specified, the term "auxiliary agent" refers to other conventional auxiliary agents in the art, excluding antistatic agents.

[0073] In a preferred embodiment of the present invention, the adjuvant is preferably an antioxidant.

[0074] In this invention, there is no particular limitation on the type of antioxidant, which can be a conventional type of antioxidant in the art, such as antioxidant 1010 and / or antioxidant 168.

[0075] More preferably, the antioxidant is composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 and antioxidant 168 is (1-4):1, for example, it can be 1:1, 2:1, 3:1, 4:1, or any range of two values.

[0076] In this invention, the addition of antioxidants serves two purposes: firstly, it better prevents the degradation of the matting material used in BOPE matte film from causing excessive fluctuations in the melt index, which in turn leads to unstable wavy patterns on the film surface; secondly, it better prevents the formation of gel points that could affect subsequent film stretching and cause subsequent BOPE film breakage.

[0077] In a preferred embodiment of the present invention, the matting material further includes an antistatic agent, wherein the content of the antistatic agent is 0.1-10 wt%, based on the sum of the weights of the first component and the second component, for example, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.2 wt%, 1.4 wt%, 1.6 wt%, 1.8 wt%, 2 wt%, 2.2 wt%, 2.4 wt%, 2.6 wt%, 2.8 wt%, 3 wt%, 3.2 wt%, 3.4 wt%, 3.6 wt%, 3. 8wt%, 4wt%, 4.2wt%, 4.4wt%, 4.6wt%, 4.8wt%, 5wt%, 5.2wt%, 5.4wt%, 5.6wt%, 5.8wt%, 6wt%, 6.2wt%, 6.4wt%, 6.6wt%, 6.8wt%, 7wt%, 7.2wt%, 7.4wt%, 7.6wt%, 7.8wt%, 8wt%, 8.2wt%, 8.4wt%, 8.6wt%, 8.8wt%, 9wt%, 9.2wt%, 9.4wt%, 9.6wt%, 9.8wt%, 10wt%, and any range of two values, preferably 0.5-5wt%.

[0078] In this invention, the inventors discovered that adding an antistatic agent to the matting agent can effectively reduce the surface resistivity of the BOPE matting film, thereby eliminating or reducing static electricity accumulation, improving processing and ease of use, and without affecting the haze, gloss, and matting uniformity of the matting film made from the matting agent.

[0079] According to the present invention, preferably, the antistatic agent is at least one of the following: nonionic antistatic agent (such as polyethylene glycol and its derivatives, glycerol esters, etc.), cationic antistatic agent (such as quaternary ammonium salts, etc.), amphoteric antistatic agent (such as betaine, etc.), and polymeric antistatic agent (such as polyether copolymers, polyamide-polyether block copolymers, polymers containing ionic groups, etc.).

[0080] In a preferred embodiment of the present invention, the antistatic agent is selected from at least one of glycerol fatty acid ester antistatic agents, betaine antistatic agents, and polyamide-polyether block copolymers.

[0081] In one specific embodiment of the present invention, the antistatic agent is a composition of a betaine-based antistatic agent and a polyamide-polyether block copolymer, wherein the weight ratio of the betaine-based antistatic agent to the polyamide-polyether block copolymer is 1:1-5, for example, it can be 1:1, 1:2, 1:3, 1:4, 1:5, or any range of two values.

[0082] A second aspect of the present invention provides a method for preparing the above-mentioned matting material for BOPE matte film, the method comprising: mixing a first component, a second component and optional additives, extruding, granulating and drying to obtain the matting material for BOPE matte film.

[0083] In this invention, the preparation method of the matting material for BOPE matting film is simple, has good processing fluidity, and the raw materials are mixed evenly, which effectively improves the overall fluidity and tensile uniformity of the surface layer of the matting film, thereby facilitating the acquisition of BOPE matting film with good matting effect and high matting uniformity.

[0084] In a preferred embodiment of the present invention, the preparation method includes: mixing, extruding, granulating and drying a first component, a second component, an antistatic agent and optional additives to obtain the matting material for BOPE matting film.

[0085] In one specific embodiment of the present invention, preferably, the preparation method includes: mixing, extruding, granulating and drying the first component granules, the second component granules and optional additives to obtain the matting material for BOPE matting film.

[0086] In a preferred embodiment of the present invention, the preparation method includes: mixing, extruding, granulating and drying a first component granule, a second component granule, an antistatic agent and optional additives to obtain the matting material for BOPE matting film.

[0087] According to the present invention, preferably, the extrusion temperature is 180-250°C, for example, it can be 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, or any range of two values. This extrusion temperature refers to the extrusion temperature of the matte material used to prepare the BOPE matte film.

[0088] According to the present invention, preferably, the method for preparing the first component granules includes the following steps: mixing, extruding, granulating and drying the components of the first component to obtain the first component granules.

[0089] In one specific embodiment of the present invention, preferably, in the preparation of the first component granules: the mixing time is 1-10 min, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or any range of two values; the extrusion temperature is 180-250℃, for example, it can be 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, or any range of two values.

[0090] According to the present invention, when the second component includes polypropylene resin and nucleating agent, the preparation method of the second component granules includes the following steps: mixing, extruding, granulating and drying the components of the second component to obtain the second component granules.

[0091] In a specific embodiment of the present invention, preferably, in the preparation of the second component granules: the mixing time is 1-10 min, for example, it can be 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or any range of two values; the extrusion temperature is 180-250℃, for example, it can be 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, or any range of two values.

[0092] In this invention, when the second component is polypropylene resin, the second component granules are commercially available polypropylene resin granules.

[0093] In this invention, multiple twin-screw processing steps allow for more thorough mixing of the components.

[0094] A third aspect of the present invention provides a BOPE matte film, which comprises, in sequence, a first surface layer, an intermediate layer, and a second surface layer.

[0095] At least one of the first surface layer and the second surface layer is a matte layer;

[0096] The surface of the matting layer has a three-dimensional mesh structure, which includes fibers and hill-shaped protrusions.

[0097] In this invention, the surface of the matting layer has a three-dimensional mesh structure similar to a fishing net; and the three-dimensional mesh structure includes fibers and hill-shaped protrusions, which makes the matting film have higher haze and lower gloss, and has a more excellent matting effect.

[0098] In this invention, the surface structure of the matting layer was observed using an atomic force microscope (AFM).

[0099] In this invention, the surface of the matte layer refers to the side of the matte film that is in contact with air.

[0100] In this invention, the "three-dimensional network structure" refers to a three-dimensional network structure formed by in-situ fiberization of the matting material throughout the entire matting layer. The hill-like protrusions exist in the pores formed by the three-dimensional network structure and protrude from the fiber structure formed by the in-situ fiberization of the matting material constituting the three-dimensional network structure, or from the intersection of multiple fiber structures formed by the in-situ fiberization of the matting material.

[0101] In this invention, the "hill-shaped protrusion" refers to a protrusion in which the ratio of the maximum length to the minimum length of the plane at the contact point between the protrusion and the fiber structure or the aforementioned intersection is less than 2.

[0102] In one specific embodiment of the present invention, the average diameter of the fiber is 0.1-10 μm, for example, it can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm. m, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm m, 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm, 5μm, 5.1μm, 5.2μm, 5.3μm, 5.4μm, 5 .5μm, 5.6μm, 5.7μm, 5.8μm, 5.9μm, 6μm, 6.1μm, 6.2μm, 6.3μm, 6.4μm, 6.5μm, 6.6μm, 6.7μm, 6.8μm, 6.9μm, 7 μm, 7.1μm, 7.2μm, 7.3μm, 7.4μm, 7.5μm, 7.6μm, 7.7μm, 7.8μm, 7.9μm, 8μm, 8.1μm, 8.2μm, 8.3μm, 8.4μm, 8.5 μm, 8.6μm, 8.7μm, 8.8μm, 9.9μm, 10μm, and any range of two values; wherein the average minimum aspect ratio of the fiber is ≥2, for example, it can be 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, 4.2, 4.4, 4.6, 4.8, 5, 5.2, 5.4, 5.6, 5.8, 6, 6.2, 6.4, 6.6, 6.8, 7, 7.2, 7.4, 7.6, 7.8 and above.

[0103] In this invention, when the average diameter and minimum aspect ratio of the fibers in the three-dimensional mesh structure on the surface of the matting layer meet the above-mentioned range, the matting film can have higher haze, lower gloss, and a more superior matting effect.

[0104] In a preferred embodiment of the present invention, the average diameter of the fiber is 1-3 μm.

[0105] In this invention, the average diameter of the fiber is measured using atomic force microscopy (AFM). Specifically, the surface of the matting film is characterized using AFM. 200 AFM images of the matting film surface with an area of ​​50 μm × 50 μm are randomly selected. In a specific AFM image, 3-5 locations of a single fiber are randomly selected using NanoScope Analysis 1.9 software to test the diameter. The average value is then used to obtain the diameter of the single fiber. The diameters of all fibers within the field of view of the AFM image are tested, and the average value is used to obtain the diameter of the fiber in the three-dimensional mesh structure of the AFM image. The average diameter of the diameters obtained from the 200 AFM images is then calculated.

[0106] In this invention, the minimum aspect ratio of the fiber is the ratio of the straight-line distance between the two ends (entanglement points or intersection points of continuous fibers) of any single fiber in the AFM image to the diameter of that single fiber. The average minimum aspect ratio of the fiber is measured by atomic force microscopy. Specifically, atomic force microscopy is used to characterize the surface of the matting film. 200 AFM images of the matting film surface with an area of ​​50μm×50μm are randomly selected. In a specific AFM image, 3-5 positions of a single fiber are randomly selected using NanoScope Analysis 1.9 software to test the diameter. The average value is taken to obtain the diameter of the single fiber. The straight-line distance between the two ends of the single fiber is also tested, and the aspect ratio of the single fiber is calculated. The diameter of all fibers within the field of view of the AFM image and the straight-line distance between the two ends of the fibers were tested respectively. The aspect ratio of all fibers was calculated and the minimum value was taken to obtain the minimum aspect ratio of the fibers in the three-dimensional mesh structure of the AFM image. The average of the minimum aspect ratios obtained from 200 AFM images is the average minimum aspect ratio of the fibers.

[0107] In one specific embodiment of the present invention, the average diameter of the bottom surface of the hill-shaped protrusion is 0.3-11 μm, for example, it can be 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, 2.1 μm, or 2.2 μm. , 2.3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3. 6μm, 3.7μm, 3.8μm, 3.9μm, 4μm, 4.1μm, 4.2μm, 4.3μm, 4.4μm, 4.5μm, 4.6μm, 4.7μm, 4.8μm, 4.9μm, 5μm, 5.1μm, 5.2μm, 5.3μm, 5.4μm, 5.5μm, 5.6μm, 5.7μm, 5.8μm, 5.9μm, 6μm, 6.1μm, 6.2μm, 6.3μm , 6.4μm, 6.5μm, 6.6μm, 6.7μm, 6.8μm, 6.9μm, 7μm, 7.1μm, 7.2μm, 7.3μm, 7.4μm, 7.5μm, 7.6μm, 7.7 μm, 7.8μm, 7.9μm, 8μm, 8.1μm, 8.2μm, 8.3μm, 8.4μm, 8.5μm, 8.6μm, 8.7μm, 8.8μm, 9.9μm, 10μm, 10.1μm, 10.2μm, 10.3μm, 10.4μm, 10.5μm, 10.6μm, 10.7μm, 10.8μm, 10.9μm, 11μm, and any range of two values.

[0108] In this invention, when the average diameter of the bottom surface of the hill-shaped protrusions in the three-dimensional mesh structure on the surface of the matting layer meets the above-mentioned range, the matting film can have higher haze and lower gloss, and thus have a more superior matting effect.

[0109] In this invention, the "bottom surface of the hill-shaped protrusion" refers to the plane at the contact point between the hill-shaped protrusion and the three-dimensional mesh structure.

[0110] In this invention, the average diameter of the base of the hill-shaped protrusion is measured using atomic force microscopy (AFM). Specifically, the surface of the matting film is characterized using AFM. 200 AFM images of the matting film surface with an area of ​​50 μm × 50 μm are randomly selected. In a specific AFM image, the maximum and minimum lengths of the base of a particular hill-shaped protrusion are measured using NanoScope Analysis 1.9 software. The arithmetic mean ((maximum length + minimum length) / 2) is taken as the diameter of the base of that hill-shaped protrusion. The maximum and minimum lengths of the bases of all hill-shaped protrusions within the field of view of the AFM image are measured, and the diameter of the base of each hill-shaped protrusion is calculated. The average value is taken as the diameter of the base of the hill-shaped protrusion in the AFM image. The average diameter of the bases of the hill-shaped protrusions obtained from the 200 AFM images is taken as the average diameter of the base of the hill-shaped protrusion.

[0111] Wherein, the maximum length refers to the distance between the two points furthest apart on the contour of the “plane at the contact point”, and the minimum length refers to the length between the intersection points of the “plane at the contact point” that are perpendicular to the line containing the maximum length and intersect the contour of the “plane at the contact point”.

[0112] In a preferred embodiment of the present invention, the average diameter of the bottom surface of the hill-shaped protrusion is 1.1-4 μm.

[0113] In one specific embodiment of the present invention, the average surface roughness R of the matte layer is... q Values ​​range from 300 to 800 nm, for example, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, 500 nm, 510 nm, 520 nm, 530 nm, 540 nm, 5 50nm, 560nm, 570nm, 580nm, 590nm, 600nm, 610nm, 620nm, 630nm, 640nm, 650nm, 660nm, 670nm, 680nm, 690nm, 700nm, 710nm, 720nm, 730nm, 740nm, 750nm, 760nm, 770nm, 780nm, 790nm, 800nm, and any range of any two values.

[0114] In this invention, when the average roughness of the matting layer surface meets the above-mentioned range, the matting film can have higher haze and lower gloss, resulting in a more superior matting effect.

[0115] In this invention, the average roughness of the matte film surface is measured by atomic force microscopy. Specifically, atomic force microscopy is used to characterize the surface of the matte film. 200 AFM images of the matte film surface with an area of ​​50μm×50μm are randomly selected. In a specific AFM image, the surface roughness of the matte layer in the AFM image is obtained by analyzing it using NanoScope Analysis 1.9 software. The average roughness obtained from the 200 AFM images is taken as the average surface roughness of the matte layer.

[0116] In a preferred embodiment of the present invention, the average surface roughness R of the matte layer is... q The value ranges from 310 to 730 nm.

[0117] In one specific embodiment of the present invention, the average density of the hill-shaped protrusions on the surface of the matte layer is 5-120 per 2500 μm. 2 For example, it can be 5 per 2500μm 2 10 per 2500μm 2 15 per 2500μm 2 20 per 2500μm 2 25 per 2500μm 2 30 per 2500μm 2 35 per 2500μm 2 40 per 2500μm 2 45 per 2500μm 2 50 per 2500μm 2 55 per 2500μm 2 60 / 2500μm 2 65 per 2500μm 2 70 / 2500μm 2 75 per 2500μm 2 80 / 2500μm 2 85 / 2500μm 2 90 / 2500μm 2 95 per 2500μm 2 100 / 2500μm 2 105 / 2500μm 2 110 / 2500μm 2 115 / 2500μm 2 120 / 2500μm 2 , and the range of any two values.

[0118] In this invention, when the density range of the hill-shaped protrusions on the surface of the matting layer meets the above requirements, the matting film can have higher haze, lower gloss, and a more superior matting effect.

[0119] In this invention, the average density of hill-shaped protrusions on the surface of the matting layer is measured using an atomic force microscope (AFM). Specifically, an AFM is used to characterize the surface of the matting film. 200 AFM images of the matting film surface with an area of ​​50 μm × 50 μm are randomly selected. In a specific AFM image, NanoScope Analysis 1.9 software is used for analysis to count the number of all hill-shaped protrusions within the 50 μm × 50 μm field of view, which is the density of hill-shaped protrusions in that AFM. The average density of the hill-shaped protrusions is obtained by averaging the densities obtained from the 200 AFM images and rounding down.

[0120] In a preferred embodiment of the present invention, the average density of the hill-shaped protrusions on the surface of the matte layer is 10-90 per 2500 μm. 2 .

[0121] In one specific embodiment of the present invention, the average diameter of the pores in the three-dimensional mesh structure is 1-30 μm, for example, it can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, or any range of two values.

[0122] In this invention, when the average diameter of the pores in the three-dimensional mesh structure meets the above-mentioned range, the matting film can have higher haze and lower gloss, resulting in a more superior matting effect.

[0123] In this invention, the "pores" refer to the pore structure formed by the fibers formed after multiple matting materials are in situ fiberized in the three-dimensional network structure on the surface of the matting film through methods such as entanglement and crossing. The "pores" are distributed in three dimensions on the surface of the matting film.

[0124] The average diameter of the "hole" refers to the average diameter of the plane of the "hole" (the plane shown in the AFM image (2D)). The average diameter of the "hole" is measured by atomic force microscopy. Specifically, atomic force microscopy is used to characterize the surface of the matting film. 200 AFM images of the matting film surface with an area of ​​50μm×50μm are randomly selected. In a specific AFM image, the maximum and minimum lengths of a certain hole in the AFM image are measured using NanoScope Analysis 1.9 software, and the average value is recorded as the diameter of the hole. The maximum and minimum lengths of all holes within the field of view of the AFM image are measured, and the diameters of all holes are calculated and averaged to obtain the diameter of the hole in the AFM image. The average diameter of the holes obtained from the 200 AFM images is recorded as the average diameter of the hole.

[0125] The maximum length refers to the distance between the two points furthest apart in the plane of the "hole", and the minimum length refers to the length between the intersection points in the plane of the "hole" that are perpendicular to the line containing the maximum length and intersect the outline of the plane of the "hole".

[0126] In a preferred embodiment of the present invention, the average diameter of the holes in the three-dimensional mesh structure is 3-20 μm.

[0127] Referring to Figures 1-2, the three-dimensional mesh structure of the surface of the matting layer of the present invention will be further described. As shown in Figures 1 and 2, in the AFM image, the long and continuous fibers within a certain length range are the fibers in the three-dimensional mesh structure of the present invention. The areas formed by the entanglement or intersection of the above fibers are the pores of the present invention. The protrusions existing in the pores and located on the fibers or at the intersections of different fibers are the hill-shaped protrusions of the present invention.

[0128] According to the present invention, at least one of the first surface layer and the second surface layer is made of the matting material for BOPE matting film as described in the first aspect of the present invention.

[0129] In one specific embodiment of the present invention, in the BOPE matte film, the first surface layer is a matte layer and the second surface layer is a heat-sealing layer;

[0130] The heat-sealing layer is made of a heat-sealing layer composition.

[0131] The heat-sealing layer composition includes polyethylene resin, polyolefin elastomer, and optional additives;

[0132] In the heat-sealing layer composition, based on the sum of the weights of the polyethylene resin and the polyolefin elastomer, the content of the polyethylene resin is 50-90 wt%, for example, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or any two of these values; the content of the polyolefin elastomer is 10-50 wt%, for example, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, or any two of these values; and the content of the additives is 0-0.8 wt%, for example, 0 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, or any two of these values.

[0133] In this invention, the inventors discovered that by adding a specific amount of polyolefin elastomer and optional additives to the polyethylene resin in the BOPE heat-sealing layer composition, the heat-sealing layer made from the composition can achieve heat sealing at a lower temperature and maintain high heat-sealing strength.

[0134] In this invention, a specific amount of polyolefin elastomer is added to polyethylene resin. On the one hand, the addition of polyolefin elastomer can disrupt the regularity of the molecular chain arrangement of polyethylene resin, thereby reducing the melting point and crystallinity of polyethylene resin. On the other hand, compared with polyethylene resin, polyolefin elastomer has a significantly lower melting point. For the above reasons, the opening temperature of the heat-sealing layer of the BOPE heat-sealing layer composition containing polyolefin elastomer is significantly reduced.

[0135] Furthermore, compared to polyethylene resin, polyolefin elastomers have a higher melt index and lower density, resulting in superior flowability in the molten state. This enhances the melt's spreading ability during heat sealing, significantly improving the heat-sealing effect. Moreover, polyolefin elastomers effectively absorb impact energy, contributing to improved impact resistance of BOPE matte films.

[0136] In a preferred embodiment of the present invention, the content of the polyethylene resin is 50-70 wt%, the content of the polyolefin elastomer is 30-50 wt%, and the content of the additives is 0.2-0.8 wt%, based on the sum of the weights of the polyethylene resin and the polyolefin elastomer.

[0137] According to the present invention, in the heat-sealing layer composition, the polyethylene resin is selected from low-density polyethylene resin and / or linear low-density polyethylene resin.

[0138] According to the present invention, in the heat-sealing layer composition, the polyethylene resin has a melt index of 2-4 g / 10 min at 190°C and 2.16 kg, for example, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, or any combination of two values; the density of the polyethylene resin is 0.91-0.93 g / cm³. 3 For example, it can be 0.91 g / cm³. 3 0.92g / cm 3 0.93g / cm 3 , and the range of any two values.

[0139] In this invention, controlling the melt index and density of polyethylene resin within the above-mentioned range can, on the one hand, maintain sufficient fluidity and processability, which helps to maintain good film-forming properties of the film during biaxial stretching, and on the other hand, maintain similar fluidity and processability of the heat-sealing layer and the intermediate layer. This can effectively avoid defects such as deformation, uneven shrinkage, or interlayer delamination after co-extrusion of multilayer films. In addition, low-density polyethylene helps to reduce the heat-sealing temperature of the film and improve impact toughness.

[0140] According to the present invention, the polyolefin elastomer is selected from at least one of vinyl elastomers, propylene elastomers, and butene elastomers.

[0141] In one specific embodiment of the present invention, the polyolefin elastomer is a vinyl elastomer.

[0142] According to the present invention, the vinyl elastic comonomer is butene and / or octene.

[0143] According to the present invention, the melting point of the vinyl elastomer is 40-85°C, for example, it can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or any range of two values.

[0144] According to the present invention, the melt index of the vinyl elastomer at 190°C and 2.16 kg is 2-10 g / 10 min.

[0145] According to the present invention, the density of the vinyl elastomer is 0.86-0.96 g / cm³. 3 .

[0146] In this invention, when at least one of the melting point, melt index, and density of the vinyl elastomer meets the above-mentioned range, it is possible to effectively reduce the film initiation temperature and improve the heat sealing strength, while also taking into account the good processing performance of the heat sealing layer composition and the interlayer composite of the multilayer film.

[0147] Furthermore, the melting point of the vinyl elastomer is 50-70°C.

[0148] Furthermore, the vinyl elastomer has a melt index of 2-6 g / 10 min at 190°C and 2.16 kg.

[0149] Furthermore, the density of the vinyl elastomer is 0.86-0.90 g / cm³. 3 .

[0150] In this invention, there is no particular limitation on the content of comonomers in the vinyl elastomer, as long as the melting point, melt index, and density of the vinyl elastomer meet the requirements of this invention. For example, the content of comonomers in the vinyl elastomer is 8-26 mol%, preferably 10-20 mol%.

[0151] In one specific embodiment of the present invention, the polyolefin elastomer is a propylene-based elastomer, and the comonomer of the propylene-based elastomer is selected from at least one of ethylene, butene, and hexene.

[0152] According to the present invention, the melting point of the propylene-based elastomer is below 80°C, for example, it can be 75°C, 70°C, 65°C, 60°C, 55°C, 50°C and below.

[0153] According to the present invention, the melt index of the propylene-based elastomer at 190°C and 2.16 kg is 2-10 g / 10 min, for example, it can be 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, 10 g / 10 min, and any range of two values.

[0154] According to the present invention, the density of the propylene-based elastomer is 0.86-0.96 g / cm³. 3 For example, it can be 0.86 g / cm³ 3 0.87 g / cm 3 0.88g / cm 3 0.89 g / cm 3 0.9g / cm 3 0.91g / cm 3 0.92g / cm 3 0.93g / cm 3 0.94 g / cm 3 0.95g / cm 3 0.96 g / cm 3 , and the range of any two values.

[0155] In this invention, when at least one of the melting point, melt index, and density of the propylene-based elastomer meets the above-mentioned range, it is possible to effectively reduce the film initiation temperature and improve the heat sealing strength while taking into account the good processing performance of the heat sealing layer composition and the interlayer composite of the multilayer film.

[0156] Furthermore, the melting point of the propylene-based elastomer is below 70°C.

[0157] Furthermore, the melt index of the propylene-based elastomer at 190°C and 2.16 kg is 2-6 g / 10 min.

[0158] Furthermore, the density of the propylene-based elastomer is 0.86-0.90 g / cm³. 3 .

[0159] In this invention, there is no particular limitation on the content of comonomers in the propylene-based elastomer, as long as the melting point, melt index, and density of the propylene-based elastomer meet the requirements of this invention. For example, the content of comonomers in the propylene-based elastomer is 5-20 mol%, preferably 10-15 mol%.

[0160] In one specific embodiment of the present invention, the polyolefin elastomer is a butene-based elastomer.

[0161] According to the present invention, the melting point of the butene-based elastomer is below 80°C, for example, 75°C, 70°C, 65°C, 60°C, 55°C, 50°C and below.

[0162] According to the present invention, the melt index of the butene-based elastomer at 190°C and 2.16 kg is 2-10 g / 10 min, for example, it can be 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, 10 g / 10 min, and any range of two values.

[0163] According to the present invention, the density of the butene-based elastomer is 0.86-0.96 g / cm³. 3 For example, it can be 0.86 g / cm³ 3 0.87 g / cm 3 0.88g / cm 3 0.89 g / cm 3 0.9g / cm 3 0.91g / cm 3 0.92g / cm 3 0.93g / cm 3 0.94 g / cm 3 0.95g / cm3 0.96 g / cm 3 , and the range of any two values.

[0164] In this invention, when the melting point and / or melt index and / or density of the butene-based elastomer meet the above-mentioned ranges, it is possible to effectively reduce the film sealing temperature and improve the heat sealing strength while taking into account the good processing performance of the heat sealing layer composition and the interlayer composite of the multilayer film.

[0165] In a preferred embodiment of the present invention, the melting point of the butene-based elastomer is below 70°C.

[0166] In a preferred embodiment of the present invention, the melt index of the butene-based elastomer at 190°C and 2.16 kg is 2-6 g / 10 min, for example, it can be 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, or any range of two values.

[0167] In a preferred embodiment of the present invention, the density of the butene-based elastomer is 0.86-0.90 g / cm³. 3 For example, it can be 0.86 g / cm³ 3 0.87 g / cm 3 0.88g / cm 3 0.89 g / cm 3 0.9g / cm 3 , and the range of any two values.

[0168] In this invention, there is no particular limitation on the content of comonomer in the butene-based elastomer, as long as the melting point, melt index and density of the butene-based elastomer meet the requirements of this invention. For example, the content of comonomer in the butene-based elastomer is 10-20 mol%, such as 10 mol%, 12 mol%, 14 mol%, 16 mol%, 18 mol%, 20 mol%, and any range of two values.

[0169] According to the present invention, the additive in the heat-sealing layer composition is an antioxidant.

[0170] In this invention, the addition of antioxidants can prevent the heat-sealing layer composition from undergoing oxidative cross-linking or degradation during granulation under high temperature and high shear twin-screw extrusion conditions, thereby causing fluctuations in its melting point and affecting its heat-sealing performance and uniformity. At the same time, preventing oxidative cross-linking or degradation also helps to obtain a complete, smooth and uniform BOPE film in the subsequent biaxial stretching process.

[0171] In a preferred embodiment of the present invention, the antioxidant in the heat-sealing layer composition is antioxidant 1010 and / or antioxidant 168.

[0172] More preferably, the antioxidant is composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 and antioxidant 168 is (1-4):1, for example, it can be 1:1, 2:1, 3:1, 4:1, or any range of two values.

[0173] In this invention, the melt flow index of the BOPE heat-sealing composition at 190°C and 2.16 kg is 1-5 g / 10 min, for example, it can be 1 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, or any range of two values.

[0174] In this invention, the method for preparing the BOPE heat-sealing layer composition includes: blending polyethylene resin, polyolefin elastomer and optional additives, twin-screw extrusion, granulation, and drying to obtain the BOPE heat-sealing layer composition.

[0175] In this invention, the preparation method of the BOPE heat-sealing layer composition is simple, with good processing performance and flowability. The raw materials of each component can be uniformly mixed, which effectively improves the surface morphology, uniformity and functionality of the BOPE film, and is conducive to obtaining a film with excellent low heat-sealing temperature and high heat-sealing strength.

[0176] Preferably, the method includes: blending polyethylene granules, polyolefin elastomer granules and additives, twin-screw extrusion, granulation, and drying to obtain the BOPE heat-sealing layer composition.

[0177] According to the present invention, preferably, when preparing the BOPE heat-sealing layer composition, the blending time is 1-10 min and the twin-screw extrusion temperature is 170-250°C.

[0178] In this invention, multiple twin-screw extrusion processes help to ensure thorough and uniform mixing of the components.

[0179] In one specific embodiment of the present invention, the BOPE matte film comprises, in sequence: a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer; wherein, at least one of the first surface layer and the second surface layer is a matte layer.

[0180] The barrier layer is made from a BOPE barrier layer composition, wherein the composition includes polyvinyl alcohol resin, plasticizer, and optional additives;

[0181] In the BOPE barrier layer composition, based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer, the content of the polyvinyl alcohol resin is 60-90 wt%, for example, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or any two of these values; the content of the plasticizer is 10-40 wt%, for example, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or any two of these values; and the content of the additives is 0-0.9 wt%, for example, 0 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, or any two of these values.

[0182] In this invention, the barrier layer is prepared using a BOPE barrier layer composition comprising polyvinyl alcohol resin, plasticizer, and optional additives. This composition exhibits excellent oxygen barrier properties, enhancing the oxygen barrier effect of the BOPE matte film. Furthermore, when the content of polyvinyl alcohol resin, plasticizer, and additives in the BOPE barrier layer composition meets the aforementioned range, the polyvinyl alcohol resin can be better plasticized, ensuring the melt processing fluidity of the polyvinyl alcohol resin and achieving a balance between the melt processing and biaxial tensile properties of the polyvinyl alcohol resin.

[0183] In this invention, the BOPE barrier layer composition with the above-mentioned specific composition and ratio is used as the barrier layer, which enables the BOPE matte film to have excellent oxygen barrier performance without affecting the haze, gloss and matting uniformity of the BOPE matte film.

[0184] In a preferred embodiment of the present invention, the content of the polyvinyl alcohol resin is 60-80 wt%, the content of the plasticizer is 20-40 wt%, and the content of the additives is 0.3-0.9 wt%, based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer.

[0185] According to the present invention, the degree of polymerization of the polyvinyl alcohol resin is 1700-2500, for example, it can be 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, and any range of two values.

[0186] And / or, the degree of alcoholysis of the polyvinyl alcohol resin is 80-99%, for example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, and any range of two values.

[0187] In this invention, when the degree of polymerization and / or degree of hydrolysis of polyvinyl alcohol resin meets the above-mentioned range, not only does the BOPE matte film containing the barrier layer made of the BOPE barrier layer composition described in this invention have excellent oxygen barrier properties, but it can also ensure the plasticizing and melt processing performance of polyvinyl alcohol.

[0188] Furthermore, the degree of polymerization of the polyvinyl alcohol resin is 1700-1800;

[0189] And / or, the degree of alcoholysis of the polyvinyl alcohol resin is 87-99%.

[0190] According to the present invention, the additive in the BOPE barrier layer composition is an antioxidant.

[0191] In this invention, the addition of antioxidants serves two purposes: firstly, it better prevents the polyvinyl alcohol resin from oxidizing and yellowing, thus affecting the appearance of the final product; secondly, it inhibits the formation of small molecules due to oxidative degradation during processing, which can lead to bubble formation.

[0192] In this invention, the specific type of antioxidant in the BOPE barrier layer composition is not particularly limited, and can be a conventional type of antioxidant in the art, for example, the antioxidant is antioxidant 1010 and / or antioxidant 168.

[0193] In one specific embodiment of the BOPE barrier layer composition of the present invention, the antioxidant is composed of antioxidant 1010 and antioxidant 168, wherein the mass ratio of antioxidant 1010 and antioxidant 168 is (1-4):1, for example, it can be 1:1, 2:1, 3:1, 4:1, or any range of two values.

[0194] According to the present invention, the plasticizer comprises small molecule polyols and polymeric polyols, wherein, based on the total weight of the plasticizer, the content of the small molecule polyols is 50-95 wt%, for example, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt%, or any two of these values; and the content of the polymeric polyols is 5-50 wt%, for example, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, or any two of these values.

[0195] In this invention, a combination of small molecule polyols and polymeric polyols is used as a plasticizer. The synergistic effect of the two can overcome the shortcomings of single polyol plasticizers and achieve a balance of comprehensive performance. Specifically, small molecule polyols can rapidly reduce the melting temperature of polyvinyl alcohol resin, increase the melt index, and improve melt flowability; while polymeric polyols can "anchor" small molecule polyols, reducing precipitation. Furthermore, polymeric polyols have a larger average molecular weight and their own ether bonds have a certain polarity, thus causing less damage to the hydrogen bond network and crystal structure of polyvinyl alcohol resin. Compared with single polyol systems, the combination system of small molecule polyols and polymeric polyols can significantly improve the water vapor and oxygen barrier properties of BOPE matte films.

[0196] Furthermore, when the content of small molecule polyols and polymeric polyols in the plasticizer meets the above range, the rapid plasticizing ability of the larger proportion of small molecule polyols improves the melt flowability of PVA; while the polymeric polyols have an anchoring effect on the small molecule polyols, inhibiting their migration. The two work together to ensure that the BOPE barrier layer composition has excellent processing performance.

[0197] According to the present invention, the small molecule polyol is selected from at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, 2,3-butanediol, 1,2-hexanediol, trimethylolpropane diethylene glycol, sorbitol, and pentaerythritol.

[0198] In a preferred embodiment of the present invention, the small molecule polyol is selected from glycerol and / or 1,4-butanediol.

[0199] According to the present invention, the average molecular weight of the polymer polyol is 200-800 g / mol, for example, it can be 200 g / mol, 300 g / mol, 400 g / mol, 500 g / mol, 600 g / mol, 700 g / mol, 800 g / mol, or any range of two values.

[0200] In this invention, polymeric polyols with the aforementioned specific average molecular weight are selected. This not only anchors small molecule polyols and inhibits their migration, but also causes less damage to the crystalline regions of polyvinyl alcohol resin in the BOPE barrier layer composition. This preserves the oxygen-blocking crystalline structure to the maximum extent, thereby ensuring the gas barrier performance of the BOPE matte film made from this composition.

[0201] According to the present invention, the polymeric polyol is polyethylene glycol.

[0202] In this invention, the melt flow index of the BOPE barrier layer composition at 200°C and 10 kg is 2.5-55 g / 10 min, for example, it can be 2.5 g / 10 min, 5 g / 10 min, 10 g / 10 min, 15 g / 10 min, 20 g / 10 min, 25 g / 10 min, 30 g / 10 min, 35 g / 10 min, 40 g / 10 min, 45 g / 10 min, 50 g / 10 min, 55 g / 10 min, or any range of two values.

[0203] In this invention, the method for preparing the BOPE barrier layer composition includes:

[0204] The polyvinyl alcohol resin, plasticizer, and optional additives are mixed, extruded, and granulated to obtain the composition for the BOPE barrier layer.

[0205] In this invention, the preparation method of the BOPE barrier layer composition is simple, with good processing performance and flowability. The raw materials of each component can be uniformly mixed, which effectively improves the surface morphology, uniformity and functionality of the BOPE film, and is conducive to obtaining a BOPE matte film with excellent barrier performance.

[0206] According to the present invention, the extrusion temperature of the composition for preparing the BOPE barrier layer is 130-200°C.

[0207] In this invention, there is no particular limitation on the mixing time of polyvinyl alcohol resin, plasticizer and additives, as long as the polyvinyl alcohol resin, plasticizer and additives are fully and evenly mixed.

[0208] In a preferred embodiment of the present invention, the method further includes: pre-mixing small molecule polyols and polymeric polyols to obtain the plasticizer.

[0209] In this invention, the mixing time of the small molecule polyol and the polymer polyol is 5-15 min.

[0210] In this invention, the materials of the first adhesive layer and the second adhesive layer are each independently maleic anhydride-grafted polyethylene and / or ethylene-acrylic acid copolymer.

[0211] According to the present invention, preferably, the intermediate layer is a glossy layer.

[0212] In one specific embodiment of the present invention, the material forming the intermediate layer is polyethylene resin for BOPE film.

[0213] In another specific embodiment of the present invention, the intermediate layer is made of a resin composition for BOPE;

[0214] The BOPE resin composition comprises a first high-density polyethylene, a second high-density polyethylene, and a cyclic olefin resin.

[0215] Based on the total weight of the BOPE resin composition, the content of the first high-density polyethylene is 10-80 wt%, for example, it can be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, or any range of two values; the content of the second high-density polyethylene is 10-80 wt%, for example, it can be 10 wt%, 15 wt%, 20 wt%, 25 wt%, or any range of two values. The content of cyclic olefin resin is 2-15 wt%, for example, it can be 2 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, and any range of two values;

[0216] In this invention, adding cyclic olefin resin to the BOPE resin composition can improve the temperature resistance and reduce the heat shrinkage rate of BOPE. This is mainly because the cyclic olefin resin molecular chain is highly rigid and has good compatibility with high-density polyethylene at low content. After BOPE film formation, the rigid molecular chains of the cyclic olefin resin can intertwine with the polyethylene molecular chains, forming anchored physical entanglement points, reducing the molecular chain mobility of polyethylene, and thus reducing the heat shrinkage rate. However, when the cyclic olefin resin content is too high, the rigid molecular chains of the cyclic olefin resin are difficult to deform significantly during biaxial stretching, leading to film rupture during the biaxial stretching process, which is difficult for continuous industrial production.

[0217] In this invention, only when the amounts of the first high-density polyethylene, the second high-density polyethylene, and the cyclic olefin resin in the BOPE resin composition meet the above-mentioned range can the polyethylene be stretched at a larger ratio and a faster speed, and the addition of the cyclic olefin resin can reduce the shrinkage rate of the BOPE film at high temperatures.

[0218] In a preferred embodiment of the present invention, the content of the first high-density polyethylene is 30-70 wt%, the content of the second high-density polyethylene is 30-70 wt%, and the content of the cyclic olefin resin is 5-15 wt%, based on the total weight of the BOPE resin composition.

[0219] According to the present invention, the melt index of the first high-density polyethylene at 190°C and 2.16 kg is 0.05-2 g / 10 min, for example, it can be 0.05 g / 10 min, 0.1 g / 10 min, 0.15 g / 10 min, 0.2 g / 10 min, 0.25 g / 10 min, 0.3 g / 10 min, 0.35 g / 10 min, 0.4 g / 10 min, 0.45 g / 10 min, 0.5 g / 10 min, 0.55 g / 10 min, 0.6 g / 10 min, 0.65 g / 10 min, 0.7 g / 10 min. The values ​​are: 0.75 g / 10 min, 0.8 g / 10 min, 0.85 g / 10 min, 0.9 g / 10 min, 0.95 g / 10 min, 1 g / 10 min, 1.1 g / 10 min, 1.2 g / 10 min, 1.3 g / 10 min, 1.4 g / 10 min, 1.5 g / 10 min, 1.6 g / 10 min, 1.7 g / 10 min, 1.8 g / 10 min, 1.9 g / 10 min, 2 g / 10 min, and any range of two values; the density of the first high-density polyethylene is 0.941 g / cm³. 3 -0.965g / cm 3 For example, it can be 0.941 g / cm³. 3 0.942 g / cm 3 0.943 g / cm 3 0.944 g / cm 3 0.945 g / cm 3 0.946 g / cm 3 0.947 g / cm 3 0.948 g / cm 3 0.949 g / cm 3 0.95g / cm 3 0.951 g / cm 3 0.952 g / cm 3 0.953 g / cm 3 0.954 g / cm 3 0.955g / cm 3 0.956 g / cm 3 0.957 g / cm 3 0.958 g / cm 3 0.959 g / cm 3 0.96 g / cm 3 0.961 g / cm 3 0.962 g / cm 3 0.963 g / cm 30.964 g / cm 3 0.965g / cm 3 , and the range of any two values.

[0220] The melt index of the second high-density polyethylene at 190°C and 2.16 kg is 10-20 g / 10 min, for example, it can be 10 g / 10 min, 12 g / 10 min, 14 g / 10 min, 16 g / 10 min, 18 g / 10 min, 20 g / 10 min, or any range of two values; the density of the second high-density polyethylene is 0.941 g / cm³. 3 -0.955g / cm 3 For example, it can be 0.941 g / cm³. 3 0.942 g / cm 3 0.943 g / cm 3 0.944 g / cm 3 0.945 g / cm 3 0.946 g / cm 3 0.947 g / cm 3 0.948 g / cm 3 0.949 g / cm 3 0.95g / cm 3 0.951 g / cm 3 0.952 g / cm 3 0.953 g / cm 3 0.954 g / cm 3 0.955g / cm 3 , and the range of any two values.

[0221] In this invention, the BOPE resin composition uses high melt index and low melt index high-density polyethylene. The low melt index first high-density polyethylene ensures sufficient physical entanglement points during subsequent biaxial stretching to guarantee a large expansion ratio. The high melt index second high-density polyethylene has sufficient melt flowability, which can significantly reduce the extruder load and increase the extrusion volume, thereby ensuring that BOPE film can be produced at a fast linear speed.

[0222] Furthermore, the melt flow index of the first high-density polyethylene at 190°C and 2.16 kg is 0.05-1 g / 10 min; the density of the first high-density polyethylene is 0.95-0.96 g / cm³. 3 .

[0223] Furthermore, the melt index of the second high-density polyethylene at 190°C and 2.16 kg is 10-20 g / 10 min; the density of the second high-density polyethylene is 0.941-0.95 g / cm³. 3 .

[0224] In this invention, the cyclic olefin resin in the BOPE resin composition may be the same as or different from the cyclic olefin resin in the matting agent for BOPE matte film described in the first aspect of this invention. Preferably, the cyclic olefin resin in the BOPE resin composition is the same as the cyclic olefin resin in the matting agent for BOPE matte film described in the first aspect of this invention.

[0225] In this invention, the glass transition temperature of the cyclic olefin resin in the BOPE resin composition is below 110°C.

[0226] In this invention, the inventors discovered that when the cyclic olefin resin content in the BOPE resin composition is high or the glass transition temperature is higher than 110°C, the cyclic olefin resin does not deform under biaxial stretching temperature, forming stress concentration points, which can lead to film rupture during biaxial stretching and make continuous film production difficult.

[0227] In this invention, the melt flow index of the BOPE resin composition at 190°C and 2.16 kg is 0.1-3 g / 10 min, for example, it can be 0.1 g / 10 min, 0.2 g / 10 min, 0.3 g / 10 min, 0.4 g / 10 min, 0.5 g / 10 min, 0.6 g / 10 min, 0.7 g / 10 min, 0.8 g / 10 min, 0.9 g / 10 min, 1 g / 10 min, 1.1 g / 10 min, 1.2 g / 10 min, or 1.3 g / 10 min. 1.4g / 10min, 1.5g / 10min, 1.6g / 10min, 1.7g / 10min, 1.8g / 10min, 1.9g / 10min, 2g / 10min, 2.1g / 10min, 2.2g / 10min, 2.3g / 10min, 2.4g / 10min, 2.5g / 10min, 2.6g / 10min, 2.7g / 10min, 2.8g / 10min, 2.9g / 10min, 3g / 10min, and any range of two values.

[0228] In one specific embodiment of the present invention, the method for preparing the BOPE resin composition includes: mixing, extruding, granulating and drying a first high-density polyethylene, a second high-density polyethylene and a cyclic olefin resin to obtain the BOPE resin composition.

[0229] In this invention, the preparation method of the BOPE resin composition is simple, with good processing performance and flowability. The raw materials of each component can be uniformly mixed, which effectively improves the surface morphology, uniformity and functionality of the BOPE film, and is conducive to obtaining a BOPE film with excellent high temperature resistance and low shrinkage.

[0230] According to the present invention, when preparing the resin composition for BOPE, the mixing time is 1-10 min.

[0231] According to the present invention, when preparing the resin composition for BOPE, the extrusion temperature is 180-250°C.

[0232] According to the present invention, the absolute value of the difference between the melt flow indexes of any two of the intermediate layer, the adhesive layer (first adhesive layer or second adhesive layer) and the surface layer (first surface layer or second surface layer) under the conditions of 190°C and 2.16 kg is ≤2 g / 10 min.

[0233] In this invention, the inventors discovered that by controlling the difference in melt index between any two layers among the intermediate layer, adhesive layer, and surface layer within the aforementioned range, the deformation of the intermediate layer, adhesive layer, and surface layer during biaxial stretching can be made more consistent, thereby obtaining a BOPE matte film with a better uniform in-situ fibrous structure.

[0234] In a preferred embodiment of the present invention, preferably, the absolute value of the difference in melt index between the intermediate layer, the adhesive layer and the surface layer at 190°C and 2.16 kg is less than 2 g / 10 min.

[0235] According to the present invention, when the BOPE matte film comprises a first surface layer, an intermediate layer and a second surface layer in sequence, the thickness of the first surface layer is 1.3-4 μm;

[0236] The thickness of the second surface layer is 1.3-4 μm;

[0237] The thickness of the intermediate layer is 9-25 μm.

[0238] According to the present invention, when the BOPE matte film comprises, in sequence, a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer, the thickness of the BOPE matte film is 22-60 μm.

[0239] In one specific embodiment of the present invention, the thickness of the first surface layer and the second surface layer are each independently 7-15% of the thickness of the BOPE matte film;

[0240] The thickness of the barrier layer is 10-20% of the thickness of the BOPE matte film;

[0241] The thickness of the intermediate layer is 60-70% of the thickness of the BOPE matte film;

[0242] The thickness of the first adhesive layer and the second adhesive layer are each independently 2.5-5% of the thickness of the BOPE matte film.

[0243] In this invention, the total thickness of the first surface layer, the second surface layer, the barrier layer, the intermediate layer, the first adhesive layer, and the second adhesive layer is the thickness of the BOPE matte film.

[0244] In this invention, when the thickness of each layer in the BOPE matting film meets the above-mentioned range, the thickness ratio of the matting layer, the barrier layer, and the intermediate layer is appropriate, and the BOPE matting film has good matting performance and oxygen and water vapor barrier performance.

[0245] According to the present invention, preferably, the haze of the BOPE matte film is greater than 90%, and the absolute value of the difference between the haze values ​​of any two points per square meter of the BOPE matte film is less than 3%.

[0246] The gloss of the BOPE matte film is less than 9.5%, and the absolute value of the difference between the gloss values ​​of any two points on the BOPE matte film per square meter is less than 3.1%.

[0247] In this invention, the surface of the matte layer has a three-dimensional mesh structure similar to a fishing net; due to the special structure of the BOPE matte film, the haze of the BOPE matte film is greater than 90%, and preferably the absolute value of the difference between the haze values ​​of any two points per square meter of BOPE matte film is less than 3%; the gloss of the BOPE matte film is less than 9.5%, and preferably the absolute value of the difference between the gloss values ​​of any two points per square meter of BOPE matte film is less than 3.1%.

[0248] In a preferred embodiment of the present invention, the haze of the BOPE matte film is greater than 90%, and the absolute value of the difference between the haze values ​​of any two points per square meter of the BOPE matte film is less than 1%; the gloss of the BOPE matte film is less than 9.5%, and the absolute value of the difference between the gloss values ​​of any two points per square meter of the BOPE matte film is less than 0.5%.

[0249] In one specific embodiment of the present invention, the surface resistivity of the BOPE matte film is less than or equal to 1×10⁻⁶. 12 Ω / sq, preferably less than or equal to 1×10 11 Ω / sq.

[0250] In one specific embodiment of the present invention, the initial sealing temperature of the BOPE matte film is ≤100℃, preferably ≤90℃;

[0251] The heat-sealing strength of the BOPE matte film is ≥10N / 15mm, preferably ≥13N / 15mm;

[0252] The impact energy of the BOPE matte film is ≥0.290J, preferably ≥0.310J.

[0253] In one specific embodiment of the present invention, the water vapor transmission rate of the BOPE matte film is less than or equal to 7 g / m². 2 / day, preferably less than 6.8 g / m 2 / day; the oxygen permeability of the BOPE matting film is less than 11 CC / m 2 / day, preferably less than or equal to 9.9CC / m 2 / day.

[0254] In one specific embodiment of the present invention, the shrinkage rate of the BOPE matte film along the MD direction is less than 5%, preferably less than 1%; and the shrinkage rate along the TD direction is less than 6%, preferably less than 1%.

[0255] A fourth aspect of the present invention provides a BOPE matte film, wherein the BOPE matte film is made from raw materials including the above-mentioned matte material for BOPE matte film.

[0256] According to the present invention, the haze of the BOPE matte film is greater than 90%, and the absolute value of the difference between the haze values ​​of any two points per square meter of the BOPE matte film is less than 3%, preferably less than 1%.

[0257] The gloss of the BOPE matte film is less than 10%, and the absolute value of the difference in gloss values ​​between any two points per square meter of the BOPE matte film is less than 3.1%, preferably less than 0.5%.

[0258] In one specific embodiment of the present invention, the surface resistivity of the BOPE matte film is less than or equal to 1×10⁻⁶. 12 Ω / sq, preferably less than or equal to 1×10 11 Ω / sq.

[0259] In one specific embodiment of the present invention, the initial sealing temperature of the BOPE matte film is ≤100℃, preferably ≤90℃;

[0260] The heat-sealing strength of the BOPE matte film is ≥10N / 15mm, preferably ≥13N / 15mm;

[0261] The impact energy of the BOPE matte film is ≥0.290J, preferably ≥0.310J.

[0262] In one specific embodiment of the present invention, the water vapor transmission rate of the BOPE matte film is less than or equal to 7 g / m². 2 / day, preferably less than or equal to 6.8g / m 2 / day; the oxygen permeability of the BOPE matting film is less than or equal to 10 CC / m 2 / day, preferably less than or equal to 9.9CC / m 2 / day.

[0263] In one specific embodiment of the present invention, the shrinkage rate of the BOPE matte film along the MD direction is less than 5%, preferably less than 1%; and the shrinkage rate along the TD direction is less than 6%, preferably less than 1%.

[0264] According to the present invention, the BOPE matte film comprises, in sequence, a first surface layer, an intermediate layer, and a second surface layer;

[0265] At least one of the first surface layer and the second surface layer is a matte layer;

[0266] Preferably, the intermediate layer is a glossy layer.

[0267] In one specific embodiment of the present invention, the first surface layer is a matte layer and the second surface layer is a heat-sealing layer.

[0268] In one specific embodiment of the present invention, the BOPE matte film comprises, in sequence: a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer; wherein, at least one of the first surface layer and the second surface layer is a matte layer.

[0269] According to the present invention, the surface of the matting layer has a three-dimensional mesh structure, the three-dimensional mesh structure comprising fibers and hill-shaped protrusions.

[0270] According to the present invention, the average diameter of the fiber is 0.1-10 μm, preferably 1-3 μm; the average minimum aspect ratio of the fiber is ≥2;

[0271] And / or, the average diameter of the bottom surface of the hill-shaped protrusion is 0.3-11 μm, preferably 1.1-4 μm;

[0272] And / or, on the surface of the matte layer, the average density of the hill-like protrusions is 5-120 per 2500 μm. 2 Preferably 10-90 per 2500μm 2 ;

[0273] And / or, the average surface roughness R of the matte layer q The value is 300 to 800 nm, preferably 310 to 730 nm;

[0274] And / or, the average diameter of the pores in the three-dimensional mesh structure is 1-30 μm, preferably 3-20 μm.

[0275] The fifth aspect of the present invention provides a method for preparing the above-mentioned BOPE matte film, the method comprising:

[0276] The raw materials of each layer are co-extruded and cast to obtain a cast sheet; then the cast sheet is subjected to longitudinal stretching and preheating, longitudinal stretching, transverse stretching and preheating, transverse stretching and shaping in sequence to obtain the BOPE matte film.

[0277] In this invention, as a preferred embodiment, the raw materials of each layer are added to the extruder of each layer and co-extruded and cast to obtain a cast sheet; then the cast sheet is subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching and shaping in sequence to obtain the BOPE matte film.

[0278] In this invention, preferably, the BOPE matte film is prepared on a biaxially oriented production line, which is preferably a BOPP production line or a BOPE production line.

[0279] According to the present invention, preferably, the temperature of the longitudinal stretching preheating is 110-130°C, the temperature of the longitudinal stretching is 110-130°C, and the longitudinal stretching ratio is 3-6.

[0280] And / or, the temperature for preheating the transverse stretching is 115-135℃, the temperature for transverse stretching is 115-135℃, and the transverse stretching ratio is 5-10;

[0281] And / or, the shaping temperature is 115-135℃.

[0282] The present invention is further illustrated by the following examples:

[0283] The adjuvants used in the following embodiments and comparative examples are all antioxidants, which are composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is 2:1.

[0284] In the following examples and comparative examples, the crystallization temperature and melting point were determined according to the following method:

[0285] The crystallization temperature and melting point of the sample were tested using differential scanning calorimetry (DSC). Specifically, a sample with a mass of about 5-8 mg was placed in an aluminum crucible and heated from 40 °C to 250 °C at a heating and cooling rate of 10 °C / min using a PerkinElmer DSC8000 differential scanning calorimeter, and then cooled from 250 °C to 40 °C to test the melting and crystallization behavior of the sample. The entire test was conducted under a nitrogen atmosphere, and the melting point and crystallization temperature of the sample were finally obtained.

[0286] The surface information of the matting layer was collected using atomic force microscopy (AFM) in tapping mode (equipment model: Dimension icon, Bruker, USA). The specific test method is as described above and will not be repeated here.

[0287] The melt index of the matting agent for matte film and the resin composition for BOPE was determined according to standard GB / T 3682.1-2018, with a test temperature of 190℃ and a load of 2.16kg.

[0288] The melt index of the composition for BOPE barrier layer was determined according to standard GB / T 3682.1-2018, with a test temperature of 200℃ and a load of 10kg.

[0289] The cast co-extrusion castings were prepared using a multi-layer extrusion casting machine, model LCR400, from Labtech, Sweden, and equipped with a composite die with a multi-layer structure.

[0290] The biaxially oriented film was prepared using a KaroIV biaxial stretching machine manufactured by Brückner GmbH, Germany. In the following examples and comparative examples, the thickness of each layer in the BOPE matte film was controlled by controlling the extrusion rate of each layer extrusion casting machine, the melt pump speed, and the stretching ratio of the biaxial stretching.

[0291] The polypropylene resin, polyethylene resin, and polyolefin elastomer used in the following examples and comparative examples are all granules;

[0292] The commercially available BOPE-specific polyethylene resin used in the examples and comparative examples was PE-L F232ZR from China Petroleum & Chemical Corporation.

[0293] Polyvinyl alcohol resin with a degree of polymerization of 1700 and a degree of alcoholysis of 88% was purchased from China Petrochemical Great Wall Energy Chemical (Ningxia) Co., Ltd.

[0294] Glycerol, 1,4-Butanediol, and polyvinyl alcohol were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0295] Example 1

[0296] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0297] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³.3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0298] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0299] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0300] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0301] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0302] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0303] Example 2

[0304] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0305] The first component comprises: a melt index of 2 g / 10 min (190 °C, 2.16 kg) and a density of 0.918 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: Component A (25 wt%), Component B (70 wt%), and Component C (5 wt%), based on the total weight of the first components.

[0306] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of homopolymer polypropylene (component A) with a melting point of 165℃ and aromatic diamide nucleating agent TMB-5 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.2 wt%; the crystallization temperature of the obtained second component is 10℃ higher than that of pure polypropylene resin.

[0307] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0308] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4.5℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0309] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0310] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0311] Example 3

[0312] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 60 wt% and the content of the second component is 40 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0313] The first component comprises: a melt index of 0.95 g / 10 min (190 °C, 2.16 kg) and a density of 0.921 g / cm³. 3Linear low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0314] The second component comprises: a melt index of 0.3 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component comprises ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and sorbitol derivative nucleating agent TH-3988 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.2 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0315] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0316] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 3℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0317] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0318] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0319] Example 4

[0320] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 50 wt% and the content of the second component is 50 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0321] The first component comprises: a melt index of 1.7 g / 10 min (190 °C, 2.16 kg) and a density of 0.919 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.924 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: Component A (30 wt%), Component B (60 wt%), and Component C (10 wt%), based on the total weight of the first components.

[0322] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component is a copolymer of ethylene and propylene polypropylene (component A) with a melting point of 165℃, and a nucleating agent NA-21 (component B) replacing aryl heterocyclic phosphate. The total weight of the second component is 99.8 wt% for component A and 0.2 wt% for component B. The crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0323] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0324] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 2℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0325] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0326] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0327] Example 5

[0328] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 55 wt% and the content of the second component is 45 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0329] The first component comprises: a melt index of 0.95 g / 10 min (190 °C, 2.16 kg) and a density of 0.921 g / cm³. 3Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: 15 wt% of component A, 70 wt% of component B, and 15 wt% of component C, based on the total weight of the first components.

[0330] The second component comprises: a melt index of 0.3 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component is a copolymer of ethylene and propylene polypropylene (component A) with a melting point of 165℃, and a nucleating agent NA-21 (component B) replacing aryl heterocyclic phosphate. The total weight of the second component is 99 wt% for component A and 1 wt% for component B. The crystallization temperature of the obtained second component is 10℃ higher than that of pure polypropylene resin.

[0331] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0332] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0333] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0334] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0335] Example 6

[0336] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 60 wt% and the content of the second component is 40 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0337] The first component comprises: a melt index of 2 g / 10 min (190 °C, 2.16 kg) and a density of 0.918 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.924 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: Component A (30 wt%), Component B (60 wt%), and Component C (10 wt%), based on the total weight of the first components.

[0338] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of homopolymer polypropylene (component A) with a melting point of 165℃ and sorbitol derivative nucleating agent TH-3988 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.2 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0339] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0340] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 3℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0341] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0342] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0343] Example 7

[0344] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, polypropylene resin, and additives; the content of the first component is 40 wt% and the content of the polypropylene resin is 60 wt% based on the sum of the weights of the first component and the polypropylene resin; the content of the additives is 0.3 wt% based on the sum of the weights of the first component and the polypropylene resin.

[0345] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0346] The second component is polypropylene resin, which has a melt index of 1.8 g / 10 min (230℃, 2.16 kg) and a density of 0.9 g / cm³. 3 1. Ethylene-propylene copolymer polypropylene with a melting point of 165℃.

[0347] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0348] The first component is mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature of each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the first component granules are obtained. The absolute value of the difference between the crystallization temperature of the polypropylene resin and the melting point of the first component is 8℃. Then, the first component granules, polypropylene resin, and additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature of each layer is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the matte material for BOPE matte film is obtained.

[0349] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0350] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0351] Comparative Example 1

[0352] This comparative example provides a matting agent for BOPE matting film, which includes: a first component, polypropylene resin, and additives; the content of the first component is 40 wt% and the content of the polypropylene resin is 60 wt% based on the sum of the weights of the first component and the polypropylene resin; the content of the additives is 0.3 wt% based on the sum of the weights of the first component and the polypropylene resin.

[0353] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 Linear low-density polyethylene (component B); wherein, based on the total weight of the first component, component A is 20 wt% and component B is 80 wt%.

[0354] The second component is polypropylene resin, which has a melt index of 1.8 g / 10 min (230℃, 2.16 kg) and a density of 0.9 g / cm³. 3 1. Ethylene-propylene copolymer polypropylene with a melting point of 165℃.

[0355] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0356] The first component is mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the first component granules are obtained. Then, the first component granules, polypropylene resin, and additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte finish for BOPE matte film is obtained. The absolute value of the difference between the crystallization temperature of the polypropylene resin and the melting point of the first component is 10℃.

[0357] This comparative example also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made from the matte material used in the BOPE matte film of this comparative example. The intermediate layer is a glossy layer, made from commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0358] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0359] Comparative Example 2

[0360] This comparative example provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0361] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 65 wt% of component B, and 20 wt% of component C, based on the total weight of the first components.

[0362] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0363] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0364] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4.1℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0365] This comparative example also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made from the matte material used in this embodiment of the BOPE matte film. The intermediate layer is a glossy layer, made from commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0366] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with an extrusion temperature of 230°C for each layer. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C. In Comparative Example 2, the first and second surface layers of the matte film cracked.

[0367] Example 8

[0368] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0369] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The first component is a linear low-density polyethylene (component B) and a cyclic olefin copolymer (Topas COC 8007F-600, Japan Polyplastics) with a glass transition temperature of 78°C (component C); wherein, based on the total weight of the first component, component A is 17 wt%, component B is 80 wt%, and component C is 3 wt%.

[0370] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0371] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0372] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4.3℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0373] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0374] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0375] Example 9

[0376] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0377] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0378] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0379] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0380] The first component, the second component, and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperatures for each stage are 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃.

[0381] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0382] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0383] Example 10

[0384] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0385] The first component comprises: a melt index of 2 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 2 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0386] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0387] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0388] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 3℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0389] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0390] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0391] Example 11

[0392] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0393] The first component comprises: a melt index of 0.1 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The first component is a linear low-density polyethylene (component B) and a cyclic olefin copolymer (Topas COC 8007F-600, Japan Polyplastics) with a glass transition temperature of 78°C (component C); wherein, based on the total weight of the first component, component A is 17 wt%, component B is 80 wt%, and component C is 3 wt%.

[0394] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0395] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0396] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 3.9℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0397] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0398] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0399] Example 12

[0400] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0401] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 The composition comprises linear low-density polyethylene (component A), linear low-density polyethylene with a melt index of 10 g / 10 min (190 °C, 2.16 kg) and a density of 0.926 g / cm³ (component B), and a cyclic olefin copolymer (Topas COC 8007F-600 from Polyplastics Japan) with a glass transition temperature of 78 °C (component C); wherein, based on the total weight of the first components, component A is 17 wt%, component B is 80 wt%, and component C is 3 wt%.

[0402] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0403] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0404] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4.2℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0405] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0406] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0407] Example 13

[0408] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0409] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3Linear low-density polyethylene (component A) with a melt index of 0.5 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The first component is a linear low-density polyethylene (component B) and a cyclic olefin copolymer (Topas COC 8007F-600, Japan Polyplastics) with a glass transition temperature of 78°C (component C); wherein, based on the total weight of the first component, component A is 17 wt%, component B is 80 wt%, and component C is 3 wt%.

[0410] The second component comprises: a melt index of 0.1 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0411] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0412] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 3.8℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0413] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0414] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0415] Comparative Example 3

[0416] This comparative example provides a matting agent for BOPE matting film, which includes: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0417] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 Linear low-density polyethylene (component B); wherein, based on the total weight of the first component, component A is 20 wt% and component B is 80 wt%.

[0418] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0419] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0420] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature of each layer is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the first component granules and the second component granules are obtained respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the first component granules, the second component granules and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the matte material for BOPE matte film is obtained.

[0421] This comparative embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made from the matte material used in this embodiment. The intermediate layer is a glossy layer made from commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0422] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0423] Test Example 1

[0424] Melt index tests were conducted on the matte materials prepared in the examples and comparative examples (test conditions: 190°C, 2.16 kg). The test data are as follows:

[0425] Table 1

[0426] As shown in Table 1, the matte material in the examples has a high melt index, and therefore has good processing performance.

[0427] Test Example 2

[0428] The matting layers of the matting films prepared in Examples 2, 5 and Comparative Example 1 were tested by atomic force microscopy, and the specific results are shown in Figures 1-3.

[0429] As shown in Figures 1-2, the surface of the matte film prepared in the embodiment has a three-dimensional network structure, which includes fibers and hill-shaped protrusions. As shown in Figure 3, the matte film of Comparative Example 1 does not have the three-dimensional network structure formed by in-situ fiberization of the matte material, but only contains a hill-shaped protrusion structure.

[0430] The average fiber diameter, average minimum aspect ratio of the fiber, average diameter of the bottom surface of the hill-shaped protrusions, average density of the hill-shaped protrusions on the surface of the matte layer, average surface roughness of the matte layer, and average diameter of the pores of the BOPE matte film prepared by atomic force microscopy are shown in Table 2.

[0431] Test Example 3

[0432] Haze and gloss tests were performed on the BOPE matte films prepared in the examples and comparative examples. Haze tests were conducted according to GB / T2410-2008, with the matte surface facing the light source. Gloss tests were conducted according to GB / T8807-1988, with an incident angle of 45° and the matte surface facing the light source. To characterize the uniformity of haze and gloss of the BOPE matte film, the results were expressed as the absolute value of the difference between haze values ​​at any two points per square meter of BOPE matte film, or the absolute value of the difference between gloss values ​​at any two points per square meter of BOPE matte film. Specific test results are shown in Table 2.

[0433] Table 2

[0434] Table 2 (continued)

[0435] As shown in Table 2, compared with the examples, Comparative Example 1, when the BOPE matting material does not contain cyclic olefin resin and polypropylene nucleating agent, cannot form a three-dimensional network structure containing fibers and hill-like protrusions, resulting in poor matting performance and uniformity of the BOPE matting film. Compared with the examples, Comparative Example 3, when the BOPE matting material contains only polypropylene nucleating agent and no cyclic olefin resin, results in a matting film surface with only hill-like protrusions and a simpler surface structure, thus achieving higher surface gloss. Compared with the examples, the cyclic olefin resin content in the BOPE matting material in Comparative Example 2 is higher, leading to surface film breakage during subsequent biaxial stretching, making it difficult to achieve continuous and stable production of biaxially stretched matting films. Through comparison between different examples, by optimizing the composition and preparation process of the matting material in the examples, the surface structure of the BOPE matting film containing a three-dimensional network structure with fibers and hill-like protrusions can be controlled, thereby achieving control over the matting performance and uniformity of the BOPE matting film in the examples.

[0436] Example A1

[0437] This embodiment provides a high-temperature resistant, low-shrinkage BOPE matte film surface layer matte material and an intermediate layer resin composition. The surface layer matte material includes: a first component, a second component, and an additive; the content of the first component is 50 wt% and the content of the second component is 50 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0438] The first component comprises: a melt index of 1.7 g / 10 min (190 °C, 2.16 kg) and a density of 0.919 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.924 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: Component A (30 wt%), Component B (60 wt%), and Component C (10 wt%), based on the total weight of the first components.

[0439] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3The second component is a copolymer of ethylene and propylene polypropylene (component A) with a melting point of 165℃, and a nucleating agent NA-21 (component B) replacing aryl heterocyclic phosphate. The total weight of the second component is 99.8 wt% for component A and 0.5 wt% for component B. The crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0440] The intermediate layer resin composition comprises: a first high-density polyethylene, a second high-density polyethylene, and a first cyclic olefin resin. The intermediate layer raw materials, based on their total weight, contain 45 wt% of the first high-density polyethylene, 45 wt% of the second high-density polyethylene, and 10 wt% of the cyclic olefin resin. The first high-density polyethylene has a melt index of 0.05 g / 10 min at 190°C and 2.16 kg, and a density of 0.95 g / cm³. 3 The melt flow index of the second high-density polyethylene at 190°C and 2.16 kg was 10 g / 10 min; the density of the second high-density polyethylene was 0.95 g / cm³. 3 The cyclic olefin resin is a cyclic olefin copolymer with a glass transition temperature of 65°C (Topas COC 9506F-500 from Polyplastics, Japan).

[0441] The preparation method of the above-mentioned matting agent for the surface layer of BOPE matting film is as follows:

[0442] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 2℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte finish for BOPE matte film is obtained.

[0443] The preparation method of the above-mentioned resin composition for the intermediate layer of BOPE matte film is as follows:

[0444] High-density polyethylene (HDPE), high-density polyethylene (HDPE), and cyclic olefin resin were mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperatures for each stage were 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a resin composition for the intermediate layer of BOPE matte film was obtained.

[0445] This embodiment also provides a high-temperature resistant, low-shrinkage BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made from the BOPE matte layer composition of this embodiment. The intermediate layer is a glossy layer made from the intermediate layer resin composition of this embodiment. The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0446] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 260°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 260°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 125°C, the longitudinal stretching temperature is 125°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 132°C, the transverse stretching temperature is 132°C, the transverse stretching ratio is 8, and the setting temperature is 132°C.

[0447] Example A2

[0448] This embodiment provides a high-temperature resistant, low-shrinkage BOPE matte film surface matte material and an intermediate layer resin composition. The surface matte material includes: a first component, a second component, and an additive; the content of the first component is 55 wt% and the content of the second component is 45 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0449] The first component comprises: a melt index of 0.95 g / 10 min (190 °C, 2.16 kg) and a density of 0.921 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: 15 wt% of component A, 70 wt% of component B, and 15 wt% of component C, based on the total weight of the first components.

[0450] The second component comprises: a melt index of 0.3 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³.3 The second component is a copolymer of ethylene and propylene polypropylene (component A) with a melting point of 165℃, and a nucleating agent NA-21 (component B) replacing aryl heterocyclic phosphate. The total weight of the second component is 99 wt% for component A and 1 wt% for component B. The crystallization temperature of the obtained second component is 10℃ higher than that of pure polypropylene resin.

[0451] The intermediate layer resin composition comprises: a first high-density polyethylene, a second high-density polyethylene, and a cyclic olefin resin. The intermediate layer raw material, by weight, contains 50 wt% of the first high-density polyethylene, 45 wt% of the second high-density polyethylene, and 5 wt% of the cyclic olefin resin. The first high-density polyethylene has a melt index of 0.73 g / 10 min at 190°C and 2.16 kg; its density is 0.954 g / cm³. 3 The melt flow index of the second high-density polyethylene at 190°C and 2.16 kg was 20 g / 10 min; the density of the second high-density polyethylene was 0.941 g / cm³. 3 The cyclic olefin resin is a cyclic olefin copolymer with a glass transition temperature of 65°C (Topas COC 9506F-500 from Polyplastics, Japan).

[0452] The preparation method of the above-mentioned matting agent for the surface layer of BOPE matting film is as follows:

[0453] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for the surface layer of BOPE matte film is obtained.

[0454] The preparation method of the above-mentioned resin composition for the intermediate layer of BOPE matte film is as follows:

[0455] High-density polyethylene (HDPE), high-density polyethylene (HDPE), and cyclic olefin resin were mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperatures for each stage were 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a resin composition for the intermediate layer of BOPE matte film was obtained.

[0456] This embodiment also provides a high-temperature resistant, low-shrinkage BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers, made from the BOPE matte layer composition of this embodiment. The intermediate layer is a glossy layer, made from the resin composition used for the intermediate layer of the BOPE matte film of this embodiment. The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0457] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 260°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 260°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 125°C, the longitudinal stretching temperature is 125°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 132°C, the transverse stretching temperature is 132°C, the transverse stretching ratio is 8, and the setting temperature is 132°C.

[0458] Example A3

[0459] This embodiment provides a high-temperature resistant, low-shrinkage BOPE matte film surface matte material and a special resin for the intermediate layer. The surface matte material includes: a first component, a second component, and an additive; the content of the first component is 60 wt% and the content of the second component is 40 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0460] The first component comprises: a melt index of 2 g / 10 min (190 °C, 2.16 kg) and a density of 0.918 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.924 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: Component A (30 wt%), Component B (60 wt%), and Component C (10 wt%), based on the total weight of the first components.

[0461] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3The second component consists of homopolymer polypropylene (component A) with a melting point of 165℃ and sorbitol derivative nucleating agent TH-3988 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.2 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0462] The intermediate layer resin composition comprises: a first high-density polyethylene, a second high-density polyethylene, and a first cyclic olefin resin. The intermediate layer raw material, by weight, contains 60 wt% of the first high-density polyethylene, 30 wt% of the second high-density polyethylene, and 10 wt% of the cyclic olefin resin. The first high-density polyethylene has a melt index of 0.1 g / 10 min at 190°C and 2.16 kg, and a density of 0.95 g / cm³. 3 The melt flow index of the second high-density polyethylene at 190°C and 2.16 kg was 15 g / 10 min; the density of the second high-density polyethylene was 0.95 g / cm³. 3 The cyclic olefin resin is a cyclic olefin copolymer with a glass transition temperature of 65°C (Topas COC 8007F-600 from Polyplastics, Japan).

[0463] The preparation method of the above-mentioned matting agent for the surface layer of BOPE matting film is as follows:

[0464] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 3℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for the surface layer of BOPE matte film is obtained.

[0465] The preparation method of the above-mentioned resin composition for the intermediate layer of BOPE matte film is as follows:

[0466] High-density polyethylene (HDPE), high-density polyethylene (HDPE), and cyclic olefin resin were mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperatures for each stage were 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a resin composition for the intermediate layer of BOPE matte film was obtained.

[0467] This embodiment also provides a high-temperature resistant, low-shrinkage BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers, made from the BOPE matte layer composition of this embodiment. The intermediate layer is a glossy layer, made from the resin composition used for the intermediate layer of the BOPE matte film of this embodiment. The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0468] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 260°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 260°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 125°C, the longitudinal stretching temperature is 125°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 132°C, the transverse stretching temperature is 132°C, the transverse stretching ratio is 8, and the setting temperature is 132°C.

[0469] The melt flow index of the matte materials and intermediate layer resin compositions prepared in Examples A1-A3 was tested (test conditions: 190°C, 2.16 kg). The test data are as follows:

[0470] Table A1

[0471] As shown in Table A1, the matte materials of Examples A1-A3 have high melt flow rates, thus exhibiting good processing performance. The intermediate layer resin compositions prepared in Examples A1-A3 have suitable melt flow rates, ensuring both good casting and processing performance, and subsequent biaxial stretching film formation.

[0472] The average fiber diameter, average minimum aspect ratio of the fiber, average diameter of the bottom surface of the hill-shaped protrusions, average density of the hill-shaped protrusions on the surface of the matte layer, average surface roughness of the matte layer, and average diameter of the pores obtained by atomic force microscopy for the BOPE matte films prepared in Examples A1-A3 are shown in Table A2.

[0473] Table A2

[0474] The BOPE matte films prepared in Examples A1-A3 were subjected to haze, gloss, and heat shrinkage tests. The heat shrinkage rate was measured using a heated oven at 120°C for 2 minutes, according to the method specified in GB / T 10003-2008. Specific test results are shown in Table A3.

[0475] Table A3

[0476] As can be seen from the results in Tables A2 and A3, using the BOPE resin composition with specific composition and ratio in this invention as the raw material for preparing the intermediate layer of the BOPE matte film can result in a BOPE matte film that not only has high haze and low gloss, but also good uniformity of matte finish, and has a low thermal shrinkage rate at high temperatures.

[0477] Example B1

[0478] This embodiment provides a BOPE matte layer composition comprising: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0479] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0480] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0481] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0482] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0483] This embodiment also provides a BOPE barrier layer composition, which includes: polyvinyl alcohol resin, plasticizer, and additives; the content of polyvinyl alcohol resin is 80 wt% and the content of plasticizer is 20 wt% based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer; the content of additives is 0.5 wt% based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer.

[0484] The polyvinyl alcohol resin includes: a polyvinyl alcohol resin with a degree of polymerization of 1700 and a degree of alcoholysis of 88%.

[0485] The plasticizer comprises: glycerol (a small molecule polyol) and polyethylene glycol (a polymeric polyol with a molecular weight of 400 g / mol); wherein, based on the total weight of the plasticizer, the small molecule polyol accounts for 70 wt% and the polymeric polyol accounts for 30 wt%.

[0486] The preparation method of the above-mentioned BOPE barrier layer composition is as follows: small molecule polyol and polymer polyol are mixed for 10 min to obtain plasticizer. Polyvinyl alcohol resin, plasticizer and additives are mixed in a metered ratio by a high-speed mixer and extruded and granulated by a twin-screw extruder. The extrusion temperature of each section is 140℃-160℃-175℃-180℃-180℃-180℃-180℃-180℃, and then the BOPE barrier layer composition is obtained.

[0487] This embodiment also provides a high-BOPE matte film, the film comprising a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer. Both the first and second surface layers are matte layers, made from the matte material used in the BOPE matte film of this embodiment. The barrier layer is made from the BOPE barrier layer composition of this embodiment. The adhesive layer is made from commercially available maleic anhydride-grafted polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The intermediate layer is a glossy layer, made from commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the film is 50 μm, wherein the first and second surface layers are both 3.7 μm thick, the barrier layer is 10 μm thick, the first and second adhesive layers are both 1.3 μm thick, and the intermediate layer is 30 μm thick.

[0488] The film production is carried out on a BOPP pilot line. Specifically, the first surface layer, first adhesive layer, barrier layer, second adhesive layer, intermediate layer, and second surface layer are respectively fed into extruders A, B, C, D, E, and F for co-extrusion casting. The extrusion processing temperature of the first surface layer, second surface layer, and intermediate layer extruders is 230°C, the extrusion processing temperature of the first adhesive layer and second adhesive layer extruders is 210°C, and the extrusion processing temperature of the barrier layer extruder is 180°C. After co-extrusion casting, a cast sheet is obtained, wherein the casting die temperature is 190°C. Then, the cast sheet is subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting in sequence, and finally wound up to obtain the film. The longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 7, and the setting temperature is 125°C.

[0489] Example B2

[0490] This embodiment provides a BOPE matte layer composition comprising: a first component, a second component, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0491] The first component comprises: a melt index of 2 g / 10 min (190 °C, 2.16 kg) and a density of 0.918 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: Component A (25 wt%), Component B (70 wt%), and Component C (5 wt%), based on the total weight of the first components.

[0492] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of homopolymer polypropylene (component A) with a melting point of 165℃ and aromatic diamide nucleating agent TMB-5 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.2 wt%; the crystallization temperature of the obtained second component is 10℃ higher than that of pure polypropylene resin.

[0493] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0494] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4.5℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0495] This embodiment also provides a BOPE barrier layer composition, which includes: polyvinyl alcohol resin, plasticizer, and additives; the content of polyvinyl alcohol resin is 80 wt% and the content of plasticizer is 20 wt% based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer; the content of additives is 0.5 wt% based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer.

[0496] The polyvinyl alcohol resin includes: a polyvinyl alcohol resin with a degree of polymerization on the order of 1700 and a degree of alcoholysis of 88%.

[0497] The plasticizer comprises: glycerol (a small molecule polyol) and polyethylene glycol (a polymeric polyol with a molecular weight of 400 g / mol); wherein, based on the total weight of the plasticizer, the small molecule polyol accounts for 80 wt% and the polymeric polyol accounts for 20 wt%.

[0498] The preparation method of the above-mentioned BOPE barrier layer composition is as follows: small molecule polyol and polymer polyol are mixed for 10 min to obtain plasticizer. Polyvinyl alcohol resin, plasticizer and additives are mixed in a metered ratio by a high-speed mixer and extruded and granulated by a twin-screw extruder. The extrusion temperature of each section is 140℃-160℃-175℃-180℃-180℃-180℃-180℃-180℃, and then the BOPE barrier layer composition is obtained.

[0499] This embodiment also provides a high-BOPE matte film, the film comprising a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer. Both the first and second surface layers are matte layers, made from the BOPE matte layer composition of this embodiment. The barrier layer is made from the BOPE barrier layer composition of this embodiment. The adhesive layer is made from commercially available maleic anhydride-grafted polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The intermediate layer is a glossy layer, made from commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the film is 50 μm, wherein the first and second surface layers are both 3.7 μm thick, the barrier layer is 10 μm thick, the first and second adhesive layers are both 1.3 μm thick, and the intermediate layer is 30 μm thick.

[0500] The film production is carried out on a BOPP pilot line. Specifically, the first surface layer, first adhesive layer, barrier layer, second adhesive layer, intermediate layer, and second surface layer are respectively fed into extruders A, B, C, D, E, and F for co-extrusion casting. The extrusion processing temperature of the first surface layer, second surface layer, and intermediate layer extruders is 230°C, the extrusion processing temperature of the first adhesive layer and second adhesive layer extruders is 210°C, and the extrusion processing temperature of the barrier layer extruder is 180°C. After co-extrusion casting, a cast sheet is obtained, wherein the casting die temperature is 190°C. Then, the cast sheet is subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting in sequence, and finally wound up to obtain the film. The longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 7, and the setting temperature is 125°C.

[0501] Example B3

[0502] This embodiment provides a BOPE matte layer composition, which includes: a first component, a second component, and an additive; the content of the first component is 60 wt% and the content of the second component is 40 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0503] The first component comprises: a melt index of 0.95 g / 10 min (190 °C, 2.16 kg) and a density of 0.921 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0504] The second component comprises: a melt index of 0.3 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component comprises ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and sorbitol derivative nucleating agent TH-3988 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0505] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0506] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 3℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0507] This embodiment also provides a BOPE barrier layer composition, which includes: polyvinyl alcohol resin, plasticizer, and additives; the content of polyvinyl alcohol resin is 80 wt% and the content of plasticizer is 20 wt% based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer; the content of additives is 0.5 wt% based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer.

[0508] The polyvinyl alcohol resin includes: a polyvinyl alcohol resin with a degree of polymerization on the order of 1700 and a degree of alcoholysis of 88%.

[0509] The plasticizer comprises: glycerol (a small molecule polyol) and polyethylene glycol (a polymeric polyol with a molecular weight of 400 g / mol); wherein, based on the total weight of the plasticizer, the small molecule polyol is 90 wt% and the polymeric polyol is 10 wt%.

[0510] The preparation method of the above-mentioned BOPE barrier layer composition is as follows: small molecule polyol and polymer polyol are mixed for 10 min to obtain plasticizer. Polyvinyl alcohol resin, plasticizer and additives are mixed in a metered ratio by a high-speed mixer and extruded and granulated by a twin-screw extruder. The extrusion temperature of each section is 140℃-160℃-175℃-180℃-180℃-180℃-180℃-180℃, and then the BOPE barrier layer composition is obtained.

[0511] This embodiment also provides a high-BOPE matte film, the film comprising a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer. Both the first and second surface layers are matte layers, made from the BOPE matte layer composition of this embodiment. The barrier layer is made from the BOPE barrier layer composition of this embodiment. The adhesive layer is made from commercially available maleic anhydride-grafted polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The intermediate layer is a glossy layer, made from commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the film is 50 μm, wherein the first and second surface layers are both 3.7 μm thick, the barrier layer is 10 μm thick, the first and second adhesive layers are both 1.3 μm thick, and the intermediate layer is 30 μm thick.

[0512] The film production is carried out on a BOPP pilot line. Specifically, the first surface layer, first adhesive layer, barrier layer, second adhesive layer, intermediate layer, and second surface layer are respectively fed into extruders A, B, C, D, E, and F for co-extrusion casting. The extrusion processing temperature of the first surface layer, second surface layer, and intermediate layer extruders is 230°C, the extrusion processing temperature of the first adhesive layer and second adhesive layer extruders is 210°C, and the extrusion processing temperature of the barrier layer extruder is 180°C. After co-extrusion casting, a cast sheet is obtained, wherein the casting die temperature is 190°C. Then, the cast sheet is subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting in sequence, and finally wound up to obtain the film. The longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 7, and the setting temperature is 125°C.

[0513] The melt index of the BOPE matte film material prepared in Examples B1-B3 was tested (test conditions: 190°C, 2.16 kg), and the melt index of the BOPE barrier layer composition was tested (test conditions: 200°C, 10 kg). The test data are shown in Table B1.

[0514] Table B1

[0515] As shown in Table B1, the BOPE matte layer compositions and BOPE barrier layer compositions of Examples B1-B3 all have high melt flow rates, thus the BOPE matte layer compositions and BOPE barrier layer compositions have good processing performance.

[0516] The average fiber diameter, average minimum aspect ratio of the fiber, average diameter of the bottom surface of the hill-shaped protrusions, average density of the hill-shaped protrusions on the surface of the matte layer, average surface roughness of the matte layer, and average diameter of the pores obtained by atomic force microscopy for the BOPE matte films prepared in Examples B1-B3 are shown in Table B2.

[0517] Table B2

[0518] The BOPE matte films prepared in Examples B1-B3 were subjected to haze and gloss tests, and the specific test results are shown in Table B3.

[0519] Table B3

[0520] The BOPE matte films prepared in Examples B1-B3 were subjected to oxygen and water vapor barrier tests. The oxygen barrier test was performed according to GB / T1038.1-2022, with a test temperature of 23°C and a humidity of 50%. The water vapor barrier test was performed according to GB / T21529-2008, with a test temperature of 38°C and a humidity of 90%. The specific test results are shown in Table B4.

[0521] Table B4

[0522] As can be seen from Tables B3 and B5, using the BOPE barrier layer composition with specific composition and ratio in this invention as the barrier layer for preparing BOPE matte film can ensure that the BOPE matte film has high haze, low gloss and excellent matting uniformity, while also having excellent oxygen barrier performance.

[0523] Example C1

[0524] (1) Preparation of heat-sealing layer composition: This embodiment provides a BOPE ultra-low temperature heat-sealing layer composition, which includes: polyethylene resin, polyolefin elastomer and additives; the polyethylene resin content is 50 wt% and the polyolefin elastomer content is 50 wt% based on the sum of the weights of the polyethylene resin and the polyolefin elastomer; the additive content is 0.3 wt% based on the sum of the weights of the polyethylene resin and the polyolefin elastomer.

[0525] The polyethylene resin is linear low-density polyethylene with a melt flow index of 2 g / 10 min (190℃, 2.16 kg) and a density of 0.918 g / cm³. 3 ;

[0526] The polyolefin elastomer is a vinyl elastomer (Mitsui, Japan, DF740), with a melt index of 3.6 g / 10 min (190°C, 2.16 kg), a melting point of 52°C, and a density of 0.88 g / cm³. 3 ;

[0527] The preparation method of the above-mentioned BOPE ultra-low heat-sealing layer composition is as follows:

[0528] The linear low-density polyethylene resin and vinyl elastomer were mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, a BOPE ultra-low temperature heat-sealing layer composition was obtained.

[0529] (2) Preparation of BOPE matte layer composition: This embodiment also provides a BOPE matte layer composition, which includes: a first component, a second component and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0530] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0531] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0532] The preparation method of the above-mentioned BOPE matte layer composition is as follows:

[0533] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, a BOPE matte layer composition is obtained.

[0534] (3) Preparation of BOPE matte film: The BOPE matte film comprises an upper surface layer, an intermediate layer, and a lower surface layer. The upper surface is a matte layer made of the BOPE matte layer composition of this embodiment, and the lower surface is an ultra-low temperature heat-sealing layer made of the BOPE ultra-low temperature heat-sealing layer composition of this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190℃, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, of which the upper surface layer is 3.7 μm thick, the lower surface layer is 3.7 μm thick, and the intermediate layer is 22.6 μm thick.

[0535] The specific preparation method of the BOPE matte film is as follows: Each layer composition is added to the respective hoppers of a co-extrusion casting machine (such as the LCR400 co-extrusion casting machine from Labtech, Sweden) equipped with a three-layer composite die head. After co-extrusion casting, a cast sheet is obtained, wherein the upper surface of the cast sheet is a matte layer, the middle layer is an intermediate layer, and the lower surface is a heat-sealing layer. The casting extrusion temperature is 160-260℃, and the cooling roller temperature is 15-85℃. Then, the cast sheet is subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and shaping using a Karo IV biaxial stretching machine from Brückner, Germany. Finally, it is wound up to obtain the BOPE ultra-low temperature heat-sealing matte film. Specifically, the longitudinal stretching preheating temperature is 120℃, the longitudinal stretching temperature is 120℃, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125℃, the transverse stretching temperature is 125℃, the transverse stretching ratio is 8, and the shaping temperature is 125℃.

[0536] Example C2

[0537] (1) Preparation of heat-sealing layer composition: This embodiment provides a BOPE ultra-low temperature heat-sealing layer composition, which includes: polyethylene resin, polyolefin elastomer and additives; based on the sum of the weights of the polyethylene resin and polyolefin elastomer, the polyethylene resin content is 60 wt% and the polyolefin elastomer content is 40 wt%; based on the sum of the weights of the polyethylene resin and polyolefin elastomer, the additive content is 0.3 wt%.

[0538] The polyethylene resin is low-density polyethylene with a melt flow index of 2 g / 10 min (190℃, 2.16 kg) and a density of 0.92 g / cm³. 3 ;

[0539] The polyolefin elastomer is a vinyl elastomer (Dow Chemical, USA). TM 8200), with a melt index of 4.4 g / 10 min (190℃, 2.16 kg), a melting point of 66.2℃, and a density of 0.87 g / cm³.3 ;

[0540] The preparation method of the above-mentioned BOPE ultra-low heat-sealing layer composition is as follows:

[0541] The low-density polyethylene resin and vinyl elastomer were mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, a BOPE ultra-low temperature heat-sealing layer composition was obtained.

[0542] (2) Preparation of BOPE matte layer composition: This embodiment also provides a BOPE matte layer composition, which includes: a first component, a second component and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0543] The first component comprises: a melt index of 2 g / 10 min (190 °C, 2.16 kg) and a density of 0.918 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (TopasCOC8007F-600 from Polyplastics, Japan) with a glass transition temperature of 78°C (component C) are present. The components are: Component A (25 wt%), Component B (70 wt%), and Component C (5 wt%), based on the total weight of the first components.

[0544] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of homopolymer polypropylene (component A) with a melting point of 165℃ and aromatic diamide nucleating agent TMB-5 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.2 wt%; the crystallization temperature of the obtained second component is 10℃ higher than that of pure polypropylene resin.

[0545] The preparation method of the above-mentioned BOPE matte layer composition is as follows:

[0546] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4.5℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, a BOPE matte layer composition is obtained.

[0547] (3) Preparation of BOPE matte film: The BOPE matte film comprises an upper surface layer, an intermediate layer, and a lower surface layer. The upper surface is a matte layer made of the BOPE matte layer composition of this embodiment, and the lower surface is an ultra-low temperature heat-sealing layer made of the BOPE ultra-low temperature heat-sealing layer composition of this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190℃, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, of which the upper surface layer is 3.7 μm thick, the lower surface layer is 3.7 μm thick, and the intermediate layer is 22.6 μm thick.

[0548] The specific preparation method of the BOPE matte film is as follows: Each layer composition is added to the respective hoppers of a co-extrusion casting machine (such as the LCR400 co-extrusion casting machine from Labtech, Sweden) equipped with a three-layer composite die head. After co-extrusion casting, a cast sheet is obtained, wherein the upper surface of the cast sheet is a matte layer, the middle layer is an intermediate layer, and the lower surface is a heat-sealing layer. The casting extrusion temperature is 160-260℃, and the cooling roller temperature is 15-85℃. Then, the cast sheet is subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and shaping using a Karo IV biaxial stretching machine from Brückner, Germany. Finally, it is wound up to obtain the BOPE ultra-low temperature heat-sealing matte film. Specifically, the longitudinal stretching preheating temperature is 120℃, the longitudinal stretching temperature is 120℃, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125℃, the transverse stretching temperature is 125℃, the transverse stretching ratio is 8, and the shaping temperature is 125℃.

[0549] Example C3

[0550] (1) Preparation of heat-sealing layer composition: This embodiment provides a BOPE ultra-low temperature heat-sealing layer composition, which includes: polyethylene resin, polyolefin elastomer and additives; based on the sum of the weights of the polyethylene resin and polyolefin elastomer, the polyethylene resin content is 60 wt% and the polyolefin elastomer content is 40 wt%; based on the sum of the weights of the polyethylene resin and polyolefin elastomer, the additive content is 0.3 wt%.

[0551] The polyethylene resin is low-density polyethylene with a melt flow index of 2 g / 10 min (190℃, 2.16 kg) and a density of 0.918 g / cm³. 3 ;

[0552] The polyolefin elastomer is a propylene-based elastomer (ExxonMobil, Vistamaxx 3000), with a melt index of 3.7 g / 10 min (190℃, 2.16 kg), a melting point of 67.3℃, and a density of 0.873 g / cm³. 3 ;

[0553] The preparation method of the above-mentioned BOPE ultra-low heat-sealing layer composition is as follows:

[0554] The low-density polyethylene resin and propylene-based elastomer were mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, a BOPE ultra-low temperature heat-sealing layer composition was obtained.

[0555] (2) Preparation of BOPE matte layer composition: This embodiment also provides a method for preparing a BOPE matte layer composition, which includes: a first component, a second component and an additive; the content of the first component is 55 wt% and the content of the second component is 45 wt% based on the sum of the weights of the first component and the second component; the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0556] The first component comprises: a melt index of 0.95 g / 10 min (190 °C, 2.16 kg) and a density of 0.921 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 9506F-500, Polyplastics Japan) with a glass transition temperature of 65°C (component C) are present. The components are: 15 wt% of component A, 70 wt% of component B, and 15 wt% of component C, based on the total weight of the first components.

[0557] The second component comprises: a melt index of 0.3 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3The second component is a copolymer of ethylene and propylene polypropylene (component A) with a melting point of 165℃, and a nucleating agent NA-21 (component B) replacing aryl heterocyclic phosphate. The total weight of the second component is 99 wt% for component A and 1 wt% for component B. The crystallization temperature of the obtained second component is 10℃ higher than that of pure polypropylene resin.

[0558] The preparation method of the above-mentioned BOPE matte layer composition is as follows:

[0559] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the granules of the first and second components and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder at an extrusion temperature of 170℃-220℃. After drying, a BOPE matte layer composition is obtained.

[0560] (3) Preparation of BOPE matte film: The BOPE matte film comprises an upper surface layer, an intermediate layer, and a lower surface layer. The upper surface is a matte layer made of the BOPE matte layer composition of this embodiment, and the lower surface is an ultra-low temperature heat-sealing layer made of the BOPE ultra-low temperature heat-sealing layer composition of this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190℃, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, of which the upper surface layer is 3.7 μm thick, the lower surface layer is 3.7 μm thick, and the intermediate layer is 22.6 μm thick.

[0561] The specific preparation method of the BOPE matte film is as follows: Each layer composition is added to the respective hoppers of a co-extrusion casting machine (such as the LCR400 co-extrusion casting machine from Labtech, Sweden) equipped with a three-layer composite die head. After co-extrusion casting, a cast sheet is obtained, wherein the upper surface of the cast sheet is a matte layer, the middle layer is an intermediate layer, and the lower surface is a heat-sealing layer. The casting extrusion temperature is 160-260℃, and the cooling roller temperature is 15-85℃. Then, the cast sheet is subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and shaping using a Karo IV biaxial stretching machine from Brückner, Germany. Finally, it is wound up to obtain the BOPE ultra-low temperature heat-sealing matte film. Specifically, the longitudinal stretching preheating temperature is 120℃, the longitudinal stretching temperature is 120℃, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125℃, the transverse stretching temperature is 125℃, the transverse stretching ratio is 8, and the shaping temperature is 125℃.

[0562] The melt flow index of the matte layer compositions and heat-sealing layer compositions prepared in Examples C1-C3 was tested (test conditions: 190°C, 2.16 kg), and the test data are shown in Table C1.

[0563] Table C1

[0564] As shown in Table C1, the matte layer compositions of Examples C1-C3 have a high melt index, thus exhibiting good processability. The heat-sealing layer compositions of Examples C1-C3 also have a high melt index, which helps ensure good processability, good low-temperature heat-sealing properties, and contributes to improving the uniformity of heat-sealing strength.

[0565] The average fiber diameter, average minimum aspect ratio of the fiber, average diameter of the bottom surface of the hill-shaped protrusions, average density of the hill-shaped protrusions on the surface of the matte layer, average surface roughness of the matte layer, and average diameter of the pores obtained by atomic force microscopy for the BOPE matte films prepared in Examples C1-C3 are shown in Table C2.

[0566] Table C2

[0567] The BOPE ultra-low temperature heat-sealed matte films prepared in Examples C1-C3 were subjected to haze and gloss tests, and the test results are shown in Table C3.

[0568] Table C3

[0569] The initial heat-sealing temperature, heat-sealing strength, and impact resistance of the BOPE matte films prepared in Examples C1-C3 were tested. Specifically, the test methods were as follows: the heat-sealing time was 5 seconds, and the heat-sealing temperature was adjusted flexibly within the range of 70-120℃ according to the actual heat-sealing conditions, according to standard GB / T2358-1988; the heat-sealing strength test was conducted using a film tensile testing machine with a sample width of 15 mm, a clamp spacing of 50 mm, and a strain rate of 300 mm / min, and 5-10 sets of data were taken and the average value was taken; the impact resistance was tested according to standard GB / T8809-2015, and the results are shown in Table C4.

[0570] Table C4

[0571] As can be seen from Tables C2-C4, the BOPE matte film containing the heat-sealing layer composition provided by the present invention significantly reduces the initial heat-sealing temperature of the heat-sealing layer and improves the heat-sealing strength and the impact resistance of the film without substantially affecting the optical properties of the BOPE matte film matte layer.

[0572] Example D1

[0573] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, an antistatic agent, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the antistatic agent is 2 wt% and the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0574] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0575] The second component comprises: a melt index of 1.8 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0576] The antistatic agent is dodecyl dimethyl betaine (BS-12).

[0577] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0578] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the first component granules and the second component granules are obtained respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the first component granules, the second component granules, the antistatic agent and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the matte material for BOPE matte film is obtained.

[0579] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0580] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0581] Example D2

[0582] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, an antistatic agent, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the antistatic agent is 5 wt% and the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0583] The first component comprises: a melt index of 2 g / 10 min (190 °C, 2.16 kg) and a density of 0.918 g / cm³. 3 Low-density polyethylene (component A) with a melt index of 20 g / 10 min (190℃, 2.16 kg) and a density of 0.928 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: Component A (25 wt%), Component B (70 wt%), and Component C (5 wt%), based on the total weight of the first components.

[0584] The second component comprises: a melt index of 2 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of homopolymer polypropylene (component A) with a melting point of 165℃ and aromatic diamide nucleating agent TMB-5 (component B); wherein, based on the total weight of the second component, component A is 99.8 wt% and component B is 0.2 wt%; the crystallization temperature of the obtained second component is 10℃ higher than that of pure polypropylene resin.

[0585] The antistatic agent is a polyamide-polyether block copolymer ( P22, BASF).

[0586] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0587] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, granules of the first and second components are obtained, respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4.5℃. Then, the granules of the first and second components, the antistatic agent, and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, a matte material for BOPE matte film is obtained.

[0588] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0589] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0590] Example D3

[0591] This embodiment provides a matting agent for BOPE matting film, which includes: a first component, a second component, an antistatic agent, and an additive; the content of the first component is 40 wt% and the content of the second component is 60 wt% based on the sum of the weights of the first component and the second component; the content of the antistatic agent is 4 wt% and the content of the additive is 0.3 wt% based on the sum of the weights of the first component and the second component.

[0592] The first component comprises: a melt index of 0.5 g / 10 min (190 °C, 2.16 kg) and a density of 0.916 g / cm³. 3 Linear low-density polyethylene (component A) with a melt index of 50 g / 10 min (190℃, 2.16 kg) and a density of 0.926 g / cm³. 3 The linear low-density polyethylene (component B) and the cyclic olefin copolymer (Topas COC 8007F-600, Polyplastics Japan) with a glass transition temperature of 78°C (component C) are present. The components are: 15 wt% of component A, 80 wt% of component B, and 5 wt% of component C, based on the total weight of the first components.

[0593] The second component comprises: a melt index of 0.1 g / 10 min (230 °C, 2.16 kg) and a density of 0.9 g / cm³. 3 The second component consists of ethylene-propylene copolymer polypropylene (component A) with a melting point of 165℃ and organophosphate nucleating agent NA-9930T (component B); wherein, based on the total weight of the second component, component A is 99.9 wt% and component B is 0.1 wt%; the crystallization temperature of the obtained second component is 7℃ higher than that of pure polypropylene resin.

[0594] The antistatic agent is dodecyl dimethyl betaine (BS-12) and polyamide-polyether block copolymer ( P22 (BASF) compound, with a weight ratio of 1:3.

[0595] The preparation method of the above-mentioned matting agent for BOPE matting film is as follows:

[0596] The first and second components are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the first component granules and the second component granules are obtained respectively. The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is 4℃. Then, the first component granules, the second component granules, the antistatic agent and the additive composition are mixed in a metered ratio using a high-speed mixer, and then extruded and granulated using a twin-screw extruder. The extrusion temperature for each stage is 180℃-200℃-210℃-210℃-210℃-210℃. After drying, the matte material for BOPE matte film is obtained.

[0597] This embodiment also provides a BOPE matte film, which includes an upper surface layer (first surface layer), an intermediate layer, and a lower surface layer (second surface layer). Both the upper and lower surface layers are matte layers made of the matte material used in this embodiment. The intermediate layer is a glossy layer made of commercially available BOPE-specific polyethylene resin with a melt index of 3 g / 10 min (190°C, 2.16 kg). The total thickness of the BOPE matte film is 30 μm, with the upper and lower surface layers each having a thickness of 3.7 μm, and the intermediate layer having a thickness of 22.6 μm.

[0598] The BOPE matte film is produced on a BOPP production line, specifically as follows: Raw materials for each layer are added to the extruders of each layer, with each extrusion temperature at 230°C. After co-extrusion casting, a cast sheet is obtained, with the casting die temperature at 230°C. The cast sheet is then subjected to longitudinal stretching preheating, longitudinal stretching, transverse stretching preheating, transverse stretching, and setting sequentially, and finally wound up to obtain the antistatic BOPE matte film. Specifically, the longitudinal stretching preheating temperature is 120°C, the longitudinal stretching temperature is 120°C, and the longitudinal stretching ratio is 5; the transverse stretching preheating temperature is 125°C, the transverse stretching temperature is 125°C, the transverse stretching ratio is 8, and the setting temperature is 125°C.

[0599] The melt flow index of the matte materials prepared in Examples D1-D3 was tested (test conditions: 190℃, 2.16 kg), and the test data are as follows:

[0600] Table D1

[0601] As shown in Table D1, the matte materials of Examples D1-D3 have a high melt index, and therefore have good processing performance.

[0602] The average fiber diameter, average minimum aspect ratio of the fiber, average diameter of the bottom surface of the hill-shaped protrusions, average density of the hill-shaped protrusions on the surface of the matte layer, average surface roughness of the matte layer, and average diameter of the pores obtained by atomic force microscopy for the BOPE matte films prepared in Examples D1-D3 are shown in Table D2.

[0603] Table D2

[0604] The BOPE matte films prepared in Examples D1-D3 were subjected to haze, gloss, and surface resistivity tests. The surface resistivity was measured using a Keithley 6517B Electrometer. The results are shown in Table D3.

[0605] Table D3

[0606] As can be seen from Tables D2 and D3, when using the matting material containing antistatic agent for BOPE matting film as the raw material for preparing the matting layer of BOPE matting film in this invention, it is possible to ensure that the matting film has high haze, low gloss and excellent matting uniformity, while also making the matting film have low surface resistivity and exhibiting excellent antistatic properties.

Claims

1. A matting agent for BOPE matting film, characterized in that, The matting agent comprises: a first component, a second component, and optional additives; The first component comprises: a first polyethylene resin, a second polyethylene resin, and a cyclic olefin resin; wherein, based on the total weight of the first component, the content of the cyclic olefin resin is 1-15 wt%. The second component includes: polypropylene resin and optional nucleating agent.

2. The matting agent for BOPE matting film according to claim 1, wherein, Based on the sum of the weights of the first component and the second component, the content of the first component is 30-70 wt%, and the content of the second component is 30-70 wt%. And / or, based on the sum of the weights of the first component and the second component, the content of the auxiliary agent is 0-0.8 wt%, preferably 0.2-0.8 wt%; And / or, based on the total weight of the first components, the content of the first polyethylene resin is 10-30 wt%, the content of the second polyethylene resin is 55-85 wt%, and the content of the cyclic olefin resin is 5-15 wt%. And / or, based on the total weight of the second component, the content of the polypropylene resin is 99-100 wt%, preferably 99-99.9 wt%, and the content of the nucleating agent is 0-1 wt%, preferably 0.1-1 wt%.

3. The matting agent for BOPE matting film according to claim 1 or 2, wherein, The melt flow index of the first polyethylene resin at 190℃ and 2.16 kg is 0.5-2 g / 10 min; the density of the first polyethylene resin is 0.916 g / cm³. 3 -0.924g / cm 3 ; Preferably, the first polyethylene resin is low-density polyethylene and / or linear low-density polyethylene; The melt flow index of the second polyethylene resin at 190℃ and 2.16 kg is 20-70 g / 10 min; the density of the second polyethylene resin is 0.924 g / cm³. 3 -0.930g / cm 3 ; Preferably, the second polyethylene resin is low-density polyethylene and / or linear low-density polyethylene.

4. The matting agent for BOPE matting film according to any one of claims 1-3, wherein, The cyclic olefin resin is a cyclic olefin copolymer and / or a cyclic olefin homopolymer; Preferably, the glass transition temperature of the cycloolefin resin is below 110°C.

5. The matting agent for BOPE matting film according to any one of claims 1-4, wherein, The polypropylene resin is homopolymer polypropylene and / or binary copolymer polypropylene; Preferably, the density of the polypropylene resin is 0.89 g / cm3-0.91 g / cm3; the melt index of the polypropylene resin at 230℃ and 2.16 kg is 0.1-2 g / 10 min; and the melting point of the polypropylene resin is greater than 160℃. Preferably, the binary copolymer polypropylene is ethylene-propylene copolymer polypropylene or propylene-butadiene copolymer polypropylene.

6. The matting agent for BOPE matting film according to any one of claims 1-5, wherein, The nucleating agent is at least one of sorbitol derivatives, organocarboxylic acid metal salts, amides, organophosphates, and organophosphates.

7. The matting agent for BOPE matting film according to any one of claims 1-6, wherein, The absolute value of the difference between the crystallization temperature of the second component and the melting point of the first component is less than 8.1°C, preferably less than 5°C.

8. The matting agent for BOPE matting film according to any one of claims 1-7, wherein, The adjuvant is an antioxidant; Preferably, the antioxidant is antioxidant 1010 and / or antioxidant 168; More preferably, the antioxidant is composed of antioxidant 1010 and antioxidant 168, and the mass ratio of antioxidant 1010 to antioxidant 168 is (1-4):

1.

9. The matting agent for BOPE matting film according to any one of claims 1-8, wherein, The matting agent also includes an antistatic agent, wherein the content of the antistatic agent is 0.1-10 wt%, preferably 0.5-5 wt%, based on the sum of the weights of the first component and the second component.

10. The matting agent for BOPE matting film according to claim 9, wherein, The antistatic agent is selected from at least one of nonionic antistatic agents, cationic antistatic agents, amphoteric antistatic agents, and polymeric antistatic agents.

11. A method for preparing the matting agent for BOPE matting film according to any one of claims 1-10, characterized in that, The preparation method includes: mixing, extruding, granulating and drying the first component, the second component, optional additives and optional antistatic agents to obtain the matting material for BOPE matting film; Preferably, the preparation method includes: mixing, extruding, granulating, and drying the first component granules, the second component granules, optional additives, and optional antistatic agents to obtain the matting material for BOPE matting film.

12. The preparation method according to claim 11, wherein, The preparation method of the first component granules includes the following steps: mixing, extruding, granulating and drying the components of the first component to obtain the first component granules; Preferably, in the preparation of the first component granules: the mixing time is 1-10 min, and the extrusion temperature is 180-250℃; When the second component includes polypropylene resin and a nucleating agent, the preparation method of the second component granules includes the following steps: mixing, extruding, granulating and drying the components of the second component to obtain the second component granules; Preferably, in the preparation of the second component granules: the mixing time is 1-10 min, and the extrusion temperature is 180-250℃.

13. The preparation method according to claim 10 or 11, wherein, The extrusion temperature is 180-250℃.

14. A BOPE matte film, characterized in that, The BOPE matte film comprises, in sequence, a first surface layer, an intermediate layer, and a second surface layer; Wherein, at least one of the first surface layer and the second surface layer is a matte layer; The surface of the matting layer has a three-dimensional mesh structure, which includes fibers and hill-shaped protrusions.

15. The BOPE matte film according to claim 14, wherein, The average diameter of the fiber is 0.1-10 μm, preferably 1-3 μm; the average minimum aspect ratio of the fiber is ≥2.

16. The BOPE matte film according to claim 14 or 15, wherein, The average diameter of the bottom surface of the hill-shaped protrusion is 0.3-11 μm, preferably 1.1-4 μm; And / or, on the surface of the matte layer, the average density of the hill-like protrusions is 5-120 per 2500 μm. 2 Preferably 10-90 per 2500μm 2 ; And / or, the average surface roughness R of the matte layer q The value is 300 to 800 nm, preferably 310 to 730 nm.

17. The BOPE matte film according to any one of claims 14-16, wherein, The average diameter of the pores in the three-dimensional mesh structure is 1-30 μm, preferably 3-20 μm.

18. The BOPE matte film according to any one of claims 14-17, wherein, At least one of the first and second surface layers is made from the matting material for BOPE matting film as described in any one of claims 1-10.

19. The BOPE matte film according to any one of claims 14-18, wherein, The first surface layer is a matte layer; the second surface layer is a heat-sealing layer; The heat-sealing layer is made of a heat-sealing layer composition. The heat-sealing layer composition includes polyethylene resin, polyolefin elastomer, and optional additives; In the heat-sealing layer composition, based on the sum of the weights of the polyethylene resin and the polyolefin elastomer, the content of the polyethylene resin is 50-90 wt%, the content of the polyolefin elastomer is 10-50 wt%, and the content of the additives is 0-0.8 wt%.

20. The BOPE matte film according to claim 19, wherein, The polyethylene resin in the heat-sealing layer composition is selected from low-density polyethylene resin and / or linear low-density polyethylene resin; Preferably, the polyethylene resin in the heat-sealing layer composition has a melt index of 2-4 g / 10 min at 190°C and 2.16 kg; and the density of the polyethylene resin in the heat-sealing layer composition is 0.91-0.93 g / cm³. 3 .

21. The BOPE matte film according to claim 19 or 20, wherein, The polyolefin elastomer is selected from at least one of vinyl elastomers, propylene elastomers, and butene elastomers.

22. The BOPE matte film according to claim 21, wherein, The comonomer of the vinyl elastomer is butene and / or octene; And / or, the melting point of the vinyl elastomer is 40-85°C; And / or, the vinyl elastomer has a melt index of 2-10 g / 10 min at 190°C and 2.16 kg. And / or, the density of the vinyl elastomer is 0.86-0.96 g / cm³. 3 .

23. The BOPE matte film according to claim 21, wherein, The comonomer of the propylene-based elastomer is selected from at least one of ethylene, butene, and hexene; And / or, the melting point of the propylene-based elastomer is below 80°C; And / or, the propylene-based elastomer has a melt index of 2-10 g / 10 min at 190°C and 2.16 kg. And / or, the density of the propylene-based elastomer is 0.86-0.96 g / cm³. 3 .

24. The BOPE matte film according to claim 21, wherein, The comonomer of the butene-based elastomer is ethylene; And / or, the melting point of the butene-based elastomer is below 80°C; And / or, the butene-based elastomer has a melt index of 2-10 g / 10 min at 190 °C and 2.16 kg. And / or, the density of the butene-based elastomer is 0.86-0.96 g / cm³. 3 .

25. The BOPE matte film according to any one of claims 14-24, wherein, The BOPE matte film comprises, in sequence: a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer; wherein, at least one of the first surface layer and the second surface layer is a matte layer. The barrier layer is made from a BOPE barrier layer composition, wherein the BOPE barrier layer composition includes polyvinyl alcohol resin, plasticizer, and optional additives. In the BOPE barrier layer composition, the content of polyvinyl alcohol resin is 60-90 wt%, the content of plasticizer is 10-40 wt%, and the content of additives is 0-0.9 wt%, based on the sum of the weights of the polyvinyl alcohol resin and the plasticizer.

26. The BOPE matte film according to claim 25, wherein, The degree of polymerization of the polyvinyl alcohol resin is 1700-2500; And / or, the degree of alcoholysis of the polyvinyl alcohol resin is 80-99%.

27. The BOPE matte film according to claim 25 or 26, wherein, The plasticizer comprises small molecule polyols and polymeric polyols, wherein, based on the total weight of the plasticizer, the content of the small molecule polyols is 50-95 wt%, and the content of the polymeric polyols is 5-50 wt%. Preferably, the small molecule polyol is selected from at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, 1,4-butanediol, 2,3-butanediol, 1,2-hexanediol, trimethylolpropane diethylene glycol, sorbitol, and pentaerythritol. Preferably, the average molecular weight of the polymer polyol is 200-800 g / mol; Preferably, the polymeric polyol is polyethylene glycol.

28. The BOPE matte film according to any one of claims 25-27, wherein, The first adhesive layer and the second adhesive layer are each independently made of maleic anhydride-grafted polyethylene and / or ethylene-acrylic acid copolymer.

29. The BOPE matte film according to any one of claims 14-28, wherein, The intermediate layer is a smooth layer; Preferably, the intermediate layer is made of polyethylene resin for BOPE films, or... The intermediate layer is made of a BOPE resin composition, wherein the BOPE resin composition comprises a first high-density polyethylene, a second high-density polyethylene, and a cyclic olefin resin. In the BOPE resin composition, the content of the first high-density polyethylene is 10-80 wt%, the content of the second high-density polyethylene is 10-80 wt%, and the content of the cyclic olefin resin is 2-15 wt%, based on the total weight of the composition.

30. The BOPE matte film according to claim 29, wherein, The melt flow index of the first high-density polyethylene at 190℃ and 2.16 kg is 0.05-2 g / 10 min; the density of the first high-density polyethylene is 0.941 g / cm³. 3 -0.965g / cm 3 ; The melt flow index of the second high-density polyethylene at 190°C and 2.16 kg was 10-20 g / 10 min; the density of the second high-density polyethylene was 0.941 g / cm³. 3 -0.955g / cm 3 .

31. The BOPE matte film according to claim 29 or 30, wherein, In the BOPE resin composition, the cyclic olefin resin is a cyclic olefin copolymer and / or a cyclic olefin homopolymer; Preferably, in the BOPE resin composition, the glass transition temperature of the cyclic olefin resin is below 110°C.

32. The BOPE matte film according to any one of claims 14-31, wherein, The absolute value of the difference between the melt indexes of any two of the intermediate layer, top layer, and optional adhesive layer at 190°C and 2.16 kg is ≤2 g / 10 min.

33. The BOPE matte film according to any one of claims 14-32, wherein, The haze of the BOPE matte film is greater than 90%, and the absolute value of the difference between the haze values ​​of any two points per square meter of the BOPE matte film is less than 3%, preferably less than 1%. The gloss of the BOPE matte film is less than 9.5%, and the absolute value of the difference between the gloss values ​​of any two points on each square meter of the BOPE matte film is less than 3.1%, preferably less than 0.5%. Preferably, the surface resistivity of the BOPE matte film is less than or equal to 1×10⁻⁶. 12 Ω / sq, preferably less than or equal to 1×10 11 Ω / sq; Preferably, the initial sealing temperature of the BOPE matte film is ≤100℃, more preferably ≤90℃; The heat-sealing strength of the BOPE matte film is ≥10N / 15mm, preferably ≥13N / 15mm; The impact energy of the BOPE matte film is ≥0.290J, preferably ≥0.310J; Preferably, the water vapor transmission rate of the BOPE matte film is less than or equal to 7 g / m³. 2 / day, preferably less than or equal to 6.8g / m 2 / day; the oxygen permeability of the BOPE matting film is less than or equal to 11 CC / m 2 / day, preferably less than or equal to 9.9CC / m 2 / day; Preferably, the shrinkage rate of the BOPE matte film along the MD direction is less than 5%, more preferably less than 1%; and the shrinkage rate along the TD direction is less than 6%, more preferably less than 1%.

34. The BOPE matte film according to any one of claims 14-33, wherein, When the BOPE matte film comprises a first surface layer, an intermediate layer, and a second surface layer in sequence, the thickness of the first surface layer is 1.3-4 μm; The thickness of the second surface layer is 1.3-4 μm; The thickness of the intermediate layer is 9-25 μm; or, When the BOPE matte film sequentially comprises: a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer, the thickness of the first surface layer and the second surface layer are each independently 7-15% of the thickness of the BOPE matte film. The thickness of the barrier layer is 10-20% of the thickness of the BOPE matte film; The thickness of the intermediate layer is 60-70% of the thickness of the BOPE matte film; The thickness of the first adhesive layer and the second adhesive layer are each independently 2.5-5% of the thickness of the BOPE matte film.

35. A BOPE matte film, characterized in that, The BOPE matte film is made from raw materials including the matte material for BOPE matte film as described in any one of claims 1-10.

36. The BOPE matte film according to claim 35, wherein, The haze of the BOPE matte film is greater than 90%, and the absolute value of the difference between the haze values ​​of any two points per square meter of the BOPE matte film is less than 3%, preferably less than 1%. The gloss of the BOPE matte film is less than 9.5%, and the absolute value of the difference between the gloss values ​​of any two points on each square meter of the BOPE matte film is less than 3.1%, preferably less than 0.5%. Preferably, the surface resistivity of the BOPE matte film is less than or equal to 1×10⁻⁶. 12 Ω / sq, preferably less than or equal to 1×10 11 Ω / sq; Preferably, the initial sealing temperature of the BOPE matte film is ≤100℃, more preferably ≤90℃; The heat-sealing strength of the BOPE matte film is ≥10N / 15mm, preferably ≥13N / 15mm; The impact energy of the BOPE matte film is ≥0.290J, preferably ≥0.310J; Preferably, the water vapor transmission rate of the BOPE matte film is less than or equal to 7 g / m³. 2 / day, preferably less than or equal to 6.8g / m 2 / day; the oxygen permeability of the BOPE matting film is less than or equal to 11 CC / m 2 / day, preferably less than or equal to 9.9CC / m 2 / day; Preferably, the shrinkage rate of the BOPE matte film along the MD direction is less than 5%, more preferably less than 1%; and the shrinkage rate along the TD direction is less than 6%, more preferably less than 1%.

37. The BOPE matte film according to claim 35 or 36, wherein, The BOPE matte film comprises, in sequence, a first surface layer, an intermediate layer, and a second surface layer; At least one of the first and second surface layers is a matte layer; or The BOPE matte film comprises, in sequence: a first surface layer, a first adhesive layer, a barrier layer, a second adhesive layer, an intermediate layer, and a second surface layer; wherein, at least one of the first surface layer and the second surface layer is a matte layer. Preferably, the intermediate layer is a glossy layer; Preferably, the first surface layer is a matte layer, and the second surface layer is a heat-sealing layer.

38. The BOPE matte film according to any one of claims 35-37, wherein, The surface of the matting layer has a three-dimensional mesh structure, which includes fibers and hill-shaped protrusions.

39. The BOPE matte film according to claim 38, wherein, The average diameter of the fiber is 0.1-10 μm, preferably 1-3 μm; the average minimum aspect ratio of the fiber is ≥2. And / or, the average diameter of the bottom surface of the hill-shaped protrusion is 0.3-11 μm, preferably 1.1-4 μm; And / or, on the surface of the matte layer, the average density of the hill-like protrusions is 5-120 per 2500 μm. 2 Preferably 10-90 per 2500μm 2 ; And / or, the average surface roughness R of the matte layer q The value is 300 to 800 nm, preferably 310 to 730 nm; And / or, the average diameter of the pores in the three-dimensional mesh structure is 1-30 μm, preferably 3-20 μm.

40. A method for preparing the BOPE matte film according to any one of claims 14-39, characterized in that, The method includes: The raw materials of each layer are co-extruded and cast to obtain a cast sheet; then the cast sheet is subjected to longitudinal stretching and preheating, longitudinal stretching, transverse stretching and preheating, transverse stretching and shaping in sequence to obtain the BOPE matte film.

41. The preparation method according to claim 40, wherein, The longitudinal stretching preheating temperature is 110-130℃, the longitudinal stretching temperature is 110-130℃, and the longitudinal stretching ratio is 3-6. And / or, the temperature for preheating the transverse stretching is 115-135℃, the temperature for transverse stretching is 115-135℃, and the transverse stretching ratio is 5-10; And / or, the shaping temperature is 115-135℃.

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