A biaxially oriented polypropylene oxygen barrier film and preparation method thereof

Abstract

The present invention relates to the technical field of film preparation, and specifically discloses a biaxially oriented polypropylene oxygen barrier film and a preparation method thereof. The biaxially oriented polypropylene oxygen barrier film comprises a surface layer, a core layer and an inner layer; it is characterized in that the raw material for preparing the surface layer comprises the following components in parts by weight: 95-98 parts of copolymerized polypropylene resin and 2-5 parts of anti-blocking agent; the raw material for preparing the core layer is homopolymerized polypropylene resin; the raw material for preparing the inner layer comprises the following components in parts by weight: 95-98 parts of copolymerized polypropylene resin and 2-5 parts of anti-blocking agent. The biaxially oriented polypropylene oxygen barrier film has good oxygen barrier capability and also has good anti-slip performance.

Description

Technical Field

[0001] This invention relates to the field of thin film preparation technology, specifically to a biaxially oriented polypropylene oxygen barrier film and its preparation method. Background Technology

[0002] Biaxially oriented polypropylene (BOP) film is generally a multilayer co-extruded film, produced by co-extruded polypropylene granules into sheets, followed by stretching in both longitudinal and transverse directions. Due to its good physical stability, mechanical strength, and high transparency and gloss, it is widely used in printed films.

[0003] Chinese invention patent 201010505435.3 is a prior patent application filed by the inventor of this invention; it discloses a heat-shrinkable biaxially oriented film, which has three layers with a total thickness of 20-23 micrometers, wherein the surface layer is 0.5-1.5 micrometers thick, the core layer is 19-22 micrometers thick, and the inner layer is 0.5-1.5 micrometers thick. The surface layer is composed of the following components by weight percentage: 97%-99% copolymer polypropylene resin, 0.5%-2% lubricant, and 0.1%-1% anti-blocking agent; the core layer is composed of the following components: 80%-93% homopolymer polypropylene resin, 0.3%-3% antistatic agent, 0.1%-0.5% crystal regulator, 1%-2% surfactant, 5%-18% stiffening agent, and 0.5%-1% lubricant; the inner layer is composed of the following components: 97%-99% copolymer polypropylene resin, 0.5%-2% lubricant, and 0.1%-1% anti-blocking agent. The film has a stable thermal shrinkage rate, which changes little with storage time.

[0004] However, the inventors discovered in further research that the existing biaxially oriented films generally have only moderate oxygen barrier capabilities and need further improvement. Summary of the Invention

[0005] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides a biaxially oriented polypropylene oxygen barrier film.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] A biaxially oriented polypropylene oxygen barrier membrane includes a surface layer, a core layer, and an inner layer;

[0008] The raw materials for preparing the surface layer include the following components in parts by weight: 95-98 parts of copolymer polypropylene resin and 2-5 parts of anti-blocking agent;

[0009] The core layer is prepared from homopolymer polypropylene resin;

[0010] The raw materials for preparing the inner layer include the following components in parts by weight: 95-98 parts of copolymer polypropylene resin and 2-5 parts of anti-blocking agent.

[0011] Extensive experimental research has shown that the biaxially oriented polypropylene oxygen barrier membrane prepared by using copolymer polypropylene resin and antiblocking agent as the surface and inner layer raw materials, and homopolymer polypropylene resin as the core layer raw material, has a low gas permeability and good oxygen barrier capability.

[0012] Most preferably, the raw materials for preparing the surface layer contain the following components in parts by weight: 97 parts of copolymer polypropylene resin and 3 parts of anti-blocking agent;

[0013] The core layer is prepared from homopolymer polypropylene resin;

[0014] The raw materials for preparing the inner layer include the following components in parts by weight: 97 parts of copolymer polypropylene resin and 3 parts of anti-blocking agent.

[0015] Preferably, the anti-blocking agents for the surface and inner layers are composed of mica powder and talc powder.

[0016] The inventors further discovered in their research that a biaxially oriented polypropylene oxygen barrier film prepared by adding an anti-blocking agent composed of mica powder and talc powder to the surface and inner layers has a high coefficient of friction and good anti-slip performance.

[0017] Preferably, the weight ratio of mica powder to talc powder is 2 to 4:1;

[0018] Most preferably, the weight ratio of mica powder to talc powder is 3:1.

[0019] Preferably, the anti-blocking agents for the surface and inner layers are modified anti-blocking agents;

[0020] The modified anti-blocking agent is prepared by the following method:

[0021] (1) Mix mica powder and talc powder, then add water and stir evenly to obtain an anti-blocking agent dispersion;

[0022] (2) Heat the anti-blocking agent dispersion to 70-90°C, then add iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride, and stir at 70-90°C for 1-3 hours. After separating the solid, dry the solid to obtain the modified anti-blocking agent.

[0023] In further research, the inventors were surprised to find that the modified anti-blocking agent obtained by modifying mica powder and talc powder using the above method can significantly improve the anti-slip performance of the prepared biaxially oriented polypropylene oxygen barrier film compared with the unmodified mica powder and talc powder; at the same time, it can also significantly improve the oxygen barrier capacity of the prepared biaxially oriented polypropylene oxygen barrier film.

[0024] Here, the inventors need to clarify that in the above modification method, the modified anti-blocking agent obtained by simultaneously modifying mica powder and talc powder with iron oxide, methyltrioctylammonium chloride, and dodecyl dimethyl benzylammonium chloride is necessary to significantly improve the anti-slip performance and oxygen barrier capacity of the prepared biaxially oriented polypropylene (BOP) oxygen barrier film. Modified anti-blocking agents obtained by modifying mica powder and talc powder with only one or two of these raw materials cannot significantly improve the anti-slip performance or oxygen barrier capacity of the prepared BOP oxygen barrier film. The modified anti-blocking agent obtained by simultaneously modifying mica powder and talc powder with iron oxide, methyltrioctylammonium chloride, and dodecyl dimethyl benzylammonium chloride can synergistically improve both the anti-slip performance and oxygen barrier capacity of the prepared BOP oxygen barrier film.

[0025] More preferably, the weight ratio of mica powder and talc powder in step (1) is 2 to 4:1;

[0026] Most preferably, the weight ratio of mica powder to talc powder is 3:1.

[0027] More preferably, in step (1), the total weight ratio of mica powder and talc powder to water is 1:8 to 12.

[0028] Most preferably, in step (1), the total weight ratio of mica powder and talc powder to water is 1:9.

[0029] More preferably, in step (2), the weight ratio of iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride to the anti-blocking agent dispersion is 0.1-0.3:0.5-1:0.4-0.6:9-13.

[0030] Most preferably, in step (2), the weight ratio of iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride to the anti-blocking agent dispersion is 0.2:0.8:0.5:10.

[0031] More preferably, the thickness of the surface layer is 0.5–1.5 μm; the thickness of the core layer is 15–25 μm; and the thickness of the inner layer is 0.5–1.5 μm.

[0032] The present invention also provides a method for preparing the above-mentioned biaxially oriented polypropylene oxygen barrier film, which includes the following steps:

[0033] The raw materials for the surface layer, core layer, and inner layer are mixed evenly and then melt-extruded in their respective extruders. After casting, cooling, longitudinal stretching, transverse stretching, traction thickness measurement, and winding, the biaxially oriented polypropylene oxygen barrier film is obtained.

[0034] Beneficial Effects: This invention provides a novel biaxially oriented polypropylene (BOPP) oxygen barrier membrane. The BOPP oxygen barrier membrane prepared using copolymer polypropylene resin and an anti-blocking agent as the surface and inner layer raw materials, and homopolymer polypropylene resin as the core layer raw material, exhibits low gas permeability and good oxygen barrier capability. Furthermore, the BOPP oxygen barrier membrane prepared by adding an anti-blocking agent composed of mica powder and talc powder to the surface and inner layers has a high coefficient of friction and good anti-slip performance. In particular, the modified anti-blocking agent obtained by modifying mica powder and talc powder using the method described in this invention significantly improves the anti-slip performance of the prepared BOPP oxygen barrier membrane compared to unmodified mica powder and talc powder; it also significantly improves the oxygen barrier capability of the prepared BOPP oxygen barrier membrane. Detailed Implementation

[0035] The present invention will be further explained below with reference to specific embodiments, but the embodiments do not limit the present invention in any way.

[0036] The copolymer polypropylene resin used in the following examples is Exxon's 7032E3 copolymer polypropylene; the homopolymer polypropylene resin used is Exxon's PP4792E1 copolymer polypropylene. All other raw materials not specified are conventional raw materials that can be purchased through ordinary channels by those skilled in the art.

[0037] Example 1: Preparation of biaxially oriented polypropylene oxygen barrier film

[0038] The biaxially oriented polypropylene oxygen barrier membrane includes a surface layer, a core layer, and an inner layer;

[0039] The raw material composition of the surface layer is as follows by weight: 97 parts of copolymer polypropylene resin and 3 parts of anti-blocking agent.

[0040] The core layer is prepared from homopolymer polypropylene resin;

[0041] The raw material composition of the inner layer is as follows by weight: 97 parts copolymer polypropylene resin and 3 parts anti-blocking agent.

[0042] The anti-blocking agents for the surface and inner layers are composed of mica powder and talc powder in a weight ratio of 3:1.

[0043] Preparation method: The raw materials for the surface layer, core layer and inner layer are mixed evenly and then melt-extruded in their respective extruders. After casting and cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment, a biaxially oriented polypropylene oxygen barrier film with a surface layer thickness of 1μm, a core layer thickness of 18μm and an inner layer thickness of 1μm is obtained.

[0044] Example 2: Preparation of biaxially oriented polypropylene oxygen barrier film

[0045] The biaxially oriented polypropylene oxygen barrier membrane includes a surface layer, a core layer, and an inner layer;

[0046] The raw material composition of the surface layer is as follows by weight: 97 parts copolymer polypropylene resin and 3 parts modified anti-blocking agent.

[0047] The core layer is prepared from homopolymer polypropylene resin;

[0048] The raw material composition of the inner layer is as follows: 97 parts copolymer polypropylene resin and 3 parts modified anti-blocking agent.

[0049] The modified anti-blocking agents for the surface and inner layers are prepared by the following method:

[0050] (1) Mix mica powder and talc powder in a weight ratio of 3:1, then add water and stir evenly to obtain an anti-blocking agent dispersion; wherein the total weight of mica powder and talc powder to the weight ratio of water is 1:9.

[0051] (2) Heat the anti-blocking agent dispersion to 80°C, then add iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride, stir at 80°C for 2 hours, separate the solid, and dry the solid to obtain the modified anti-blocking agent; wherein, the weight ratio of iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride to the anti-blocking agent dispersion is 0.2:0.8:0.5:10;

[0052] Preparation method: The raw materials for the surface layer, core layer and inner layer are mixed evenly and then melt-extruded in their respective extruders. After casting and cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment, a biaxially oriented polypropylene oxygen barrier film with a surface layer thickness of 1μm, a core layer thickness of 18μm and an inner layer thickness of 1μm is obtained.

[0053] Example 3: Preparation of biaxially oriented polypropylene oxygen barrier film

[0054] The biaxially oriented polypropylene oxygen barrier membrane includes a surface layer, a core layer, and an inner layer;

[0055] The raw material composition of the surface layer is as follows by weight: 98 parts copolymer polypropylene resin and 2 parts modified anti-blocking agent.

[0056] The core layer is prepared from homopolymer polypropylene resin;

[0057] The raw material composition of the inner layer is as follows by weight: 98 parts copolymer polypropylene resin and 2 parts modified anti-blocking agent;

[0058] The modified anti-blocking agents for the surface and inner layers are prepared by the following method:

[0059] (1) Mix mica powder and talc powder in a weight ratio of 4:1, then add water and stir evenly to obtain an anti-blocking agent dispersion; wherein the total weight of mica powder and talc powder is in a weight ratio of 1:8 to water.

[0060] (2) Heat the anti-blocking agent dispersion to 90°C, then add iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride, stir at 90°C for 3 hours, separate the solid, and dry the solid to obtain the modified anti-blocking agent; wherein, the weight ratio of iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride to the anti-blocking agent dispersion is 0.3:1:0.4:9;

[0061] Preparation method: The raw materials for the surface layer, core layer and inner layer are mixed evenly and then melt-extruded in their respective extruders. After casting and cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment, a biaxially oriented polypropylene oxygen barrier film with a surface layer thickness of 1μm, a core layer thickness of 18μm and an inner layer thickness of 1μm is obtained.

[0062] Example 4: Preparation of biaxially oriented polypropylene oxygen barrier film

[0063] The biaxially oriented polypropylene oxygen barrier membrane includes a surface layer, a core layer, and an inner layer;

[0064] The raw material composition of the surface layer is as follows by weight: 95 parts copolymer polypropylene resin and 5 parts modified anti-blocking agent.

[0065] The core layer is prepared from homopolymer polypropylene resin;

[0066] The raw material composition of the inner layer is as follows by weight: 95 parts copolymer polypropylene resin and 5 parts modified anti-blocking agent.

[0067] The modified anti-blocking agents for the surface and inner layers are prepared by the following method:

[0068] (1) Mix mica powder and talc powder in a weight ratio of 2:1, then add water and stir evenly to obtain an anti-blocking agent dispersion; wherein the total weight of mica powder and talc powder to the weight ratio of water is 1:12.

[0069] (2) Heat the anti-blocking agent dispersion to 70°C, then add iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride, stir at 70°C for 1 hour, separate the solid, and dry the solid to obtain the modified anti-blocking agent; wherein, the weight ratio of iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride to the anti-blocking agent dispersion is 0.1:0.5:0.6:13;

[0070] Preparation method: The raw materials for the surface layer, core layer and inner layer are mixed evenly and then melt-extruded in their respective extruders. After casting and cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment, a biaxially oriented polypropylene oxygen barrier film with a surface layer thickness of 1μm, a core layer thickness of 18μm and an inner layer thickness of 1μm is obtained.

[0071] Comparative Example 1: Preparation of Biaxially oriented Polypropylene Oxygen Barrier Film

[0072] The difference between Comparative Example 1 and Example 2 is that the preparation methods of the modified anti-blocking agents for the surface and inner layers are different, while the rest are the same as in Example 2.

[0073] In Comparative Example 1, only iron oxide was used to modify mica powder and talc powder;

[0074] The modified anti-blocking agents for the surface and inner layers are prepared by the following method:

[0075] (1) Mix mica powder and talc powder in a weight ratio of 3:1, then add water and stir evenly to obtain an anti-blocking agent dispersion; wherein the total weight of mica powder and talc powder to the weight ratio of water is 1:9.

[0076] (2) Heat the anti-blocking agent dispersion to 80°C, then add iron oxide, stir at 80°C for 2 hours, separate the solid, and dry the solid to obtain the modified anti-blocking agent; wherein the weight ratio of iron oxide to anti-blocking agent dispersion is 0.2:10.

[0077] Comparative Example 2: Preparation of Biaxially oriented Polypropylene Oxygen Barrier Film

[0078] The difference between Comparative Example 2 and Example 2 is that the preparation methods of the modified anti-blocking agents for the surface and inner layers are different, while the rest are the same as Example 2.

[0079] In Comparative Example 2, only methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride were used to modify mica powder and talc powder;

[0080] The modified anti-blocking agents for the surface and inner layers are prepared by the following method:

[0081] (1) Mix mica powder and talc powder in a weight ratio of 3:1, then add water and stir evenly to obtain an anti-blocking agent dispersion; wherein the total weight of mica powder and talc powder to the weight ratio of water is 1:9.

[0082] (2) Heat the anti-blocking agent dispersion to 80°C, then add methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride, stir at 80°C for 2 hours, separate the solid, and dry the solid to obtain the modified anti-blocking agent; wherein, the weight ratio of methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride to the anti-blocking agent dispersion is 0.8:0.5:10.

[0083] Comparative Example 3: Preparation of Biaxially Stretched Polypropylene Oxygen Barrier Film

[0084] The difference between Comparative Example 3 and Example 2 is that the preparation methods of the modified anti-blocking agents for the surface and inner layers are different, while the rest are the same as Example 2.

[0085] In Comparative Example 3, only iron oxide and methyltrioctylammonium chloride were used to modify mica powder and talc powder;

[0086] The modified anti-blocking agents for the surface and inner layers are prepared by the following method:

[0087] (1) Mix mica powder and talc powder in a weight ratio of 3:1, then add water and stir evenly to obtain an anti-blocking agent dispersion; wherein the total weight of mica powder and talc powder to the weight ratio of water is 1:9.

[0088] (2) Heat the anti-blocking agent dispersion to 80°C, then add iron oxide and methyltrioctylammonium chloride, stir at 80°C for 2 hours, separate the solid, and dry the solid to obtain the modified anti-blocking agent; wherein the weight ratio of iron oxide and methyltrioctylammonium chloride to the anti-blocking agent dispersion is 0.2:1.3:10.

[0089] Comparative Example 4: Preparation of Biaxially Stretched Polypropylene Oxygen Barrier Film

[0090] The difference between Comparative Example 4 and Example 2 is that the preparation methods of the modified anti-blocking agents for the surface and inner layers are different, while the rest are the same as Example 2.

[0091] In Comparative Example 4, only iron oxide and dodecyl dimethyl benzyl ammonium chloride were used to modify mica powder and talc powder;

[0092] The modified anti-blocking agents for the surface and inner layers are prepared by the following method:

[0093] (1) Mix mica powder and talc powder in a weight ratio of 3:1, then add water and stir evenly to obtain an anti-blocking agent dispersion; wherein the total weight of mica powder and talc powder to the weight ratio of water is 1:9.

[0094] (2) Heat the anti-blocking agent dispersion to 80°C, then add iron oxide and dodecyl dimethyl benzyl ammonium chloride, stir at 80°C for 2 hours, separate the solid, and dry the solid to obtain the modified anti-blocking agent; wherein the weight ratio of iron oxide and dodecyl dimethyl benzyl ammonium chloride to the anti-blocking agent dispersion is 0.2:1.3:10.

[0095] The gas permeability of the biaxially oriented polypropylene oxygen barrier membranes prepared in Examples 1-4 and Comparative Examples 1-4 was tested according to the method in GB / T 1038.1-2022. In addition, the friction coefficient of the biaxially oriented polypropylene oxygen barrier membranes prepared in Examples 1-4 and Comparative Examples 1-4 was tested using a friction coefficient tester. The test results are shown in Table 1.

[0096] Table 1.

[0097]

[0098] As can be seen from the experimental data in Table 1, the biaxially oriented polypropylene oxygen barrier membrane prepared in Example 1 has a low gas permeability and a high coefficient of friction; this indicates that the biaxially oriented polypropylene oxygen barrier membrane of the present invention has good oxygen barrier capability and good anti-slip performance.

[0099] As can be seen from the experimental data in Table 1, the gas permeability of the biaxially oriented polypropylene (BOPP) oxygen barrier films prepared in Examples 2-4 is significantly lower than that of the BOPP oxygen barrier film prepared in Example 1, while their coefficient of friction is significantly higher. This indicates that the modified anti-blocking agent obtained by modifying mica powder and talc powder using the method described in this invention can significantly improve the anti-slip performance of the prepared BOPP oxygen barrier film compared to unmodified mica powder and talc powder; it can also significantly improve the oxygen barrier capacity of the prepared BOPP oxygen barrier film.

[0100] As can be seen from the experimental data in Table 1, the gas permeability of the biaxially oriented polypropylene (BOPP) oxygen barrier films prepared in Comparative Examples 1-4 did not decrease significantly compared to Example 1, and the decrease was much smaller than that in Example 2. Similarly, the coefficient of friction did not increase significantly compared to Example 1, and the increase was also much smaller than that in Example 2. This indicates that the modification method of the modified anti-blocking agent is crucial. Only by simultaneously using iron oxide, methyltrioctylammonium chloride, and dodecyl dimethyl benzylammonium chloride to modify mica powder and talc powder can the modified anti-blocking agent significantly improve the anti-slip performance and oxygen barrier capacity of the prepared BOPP oxygen barrier film. Using only one or two of these raw materials to modify mica powder and talc powder cannot significantly improve the anti-slip performance or oxygen barrier capacity of the prepared BOPP oxygen barrier film. Meanwhile, the modified anti-blocking agent obtained by modifying mica powder and talc powder with iron oxide, methyltrioctylammonium chloride and dodecyl dimethyl benzylammonium chloride can synergistically improve the anti-slip performance and oxygen barrier capacity of the prepared biaxially oriented polypropylene oxygen barrier film.

Claims

1. A biaxially oriented polypropylene oxygen barrier film, comprising a surface layer, a core layer and an inner layer; characterized in that: The raw materials for preparing the surface layer include the following components in parts by weight: 95-98 parts of copolymerized polypropylene resin and 2-5 parts of anti-blocking agent; The raw material for preparing the core layer is homopolymer polypropylene resin; The raw materials for preparing the inner layer include the following components in parts by weight: 95-98 parts of copolymerized polypropylene resin and 2-5 parts of anti-blocking agent; The anti-adhesive agent of the surface layer and the inner layer is a modified anti-adhesive agent; The modified anti-adhesive agent is prepared by the following method: (1) Mix mica powder and talc powder, then add them into water and stir evenly to obtain an anti-adhesive agent dispersion; (2) heating the anti-blocking agent dispersion to 70-90° C., then adding iron oxide, methyl trioctyl ammonium chloride and dodecyl dimethyl benzyl ammonium chloride, maintaining the temperature at 70-90° C. and stirring for 1-3 hours, separating the solid, and drying the solid to obtain the modified anti-blocking agent; In step (2), the weight ratio of iron oxide, methyl trioctyl ammonium chloride and dodecyl dimethyl benzyl ammonium chloride to the anti-adhesive dispersion is 0.1-0.3:0.5-1:0.4-0.6:9-13.

2. The biaxially oriented polypropylene oxygen barrier film according to claim 1; characterized in that: The raw materials for preparing the surface layer include the following components in parts by weight: 97 parts of copolymerized polypropylene resin and 3 parts of anti-blocking agent; The raw material for preparing the core layer is homopolymer polypropylene resin; The raw materials for preparing the inner layer include the following components in parts by weight: 97 parts of copolymerized polypropylene resin and 3 parts of anti-blocking agent.

3. The biaxially oriented polypropylene oxygen barrier film according to claim 1, characterized in that: The weight ratio of mica powder to talcum powder in step (1) is 2-4:

1.

4. The biaxially oriented polypropylene oxygen barrier film according to claim 3, characterized in that: The weight ratio of mica powder to talc powder in step (1) is 3:

1.

5. The biaxially oriented polypropylene oxygen barrier film according to claim 1, characterized in that: In step (1), the weight ratio of the total weight of mica powder and talcum powder to water is 1:8-12.

6. The biaxially oriented polypropylene oxygen barrier film according to claim 5, characterized in that: In step (1), the weight ratio of the total weight of mica powder and talcum powder to water is 1:

9.

7. The biaxially oriented polypropylene oxygen barrier film according to claim 1, characterized in that: In step (2), the weight ratio of iron oxide, methyl trioctyl ammonium chloride and dodecyl dimethyl benzyl ammonium chloride to the anti-blocking agent dispersion is 0.2:0.8:0.5:

10.

8. The biaxially oriented polypropylene oxygen barrier film according to claim 1, characterized in that: The thickness of the surface layer is 0.5 to 1.5 μm; the thickness of the core layer is 15 to 25 μm; and the thickness of the inner layer is 0.5 to 1.5 μm.

9. The method for preparing the biaxially oriented polypropylene oxygen barrier film according to any one of claims 1 to 8, characterized in that: The following steps are included: The raw materials of the surface layer, the core layer and the inner layer are mixed evenly and put into respective extruders for melt extrusion, and then subjected to casting cooling, longitudinal stretching, transverse stretching, traction thickness measurement and winding treatment to obtain the biaxially oriented polypropylene oxygen barrier film.

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