Nine-layer upward-blowing asymmetric PE / PA soft packaging film and preparation method thereof

Abstract

The invention discloses a nine-layer upward-blowing asymmetric PE / PA soft packaging film and a preparation method thereof, and relates to the technical field of packaging film materials, the film sequentially comprises an A layer, a B layer, a C layer, a D layer, an E layer, an F layer, a G layer, an H layer and an I layer from top to bottom; wherein the A layer is a PA layer; the B layer is a TIE layer; the C layer is an LLDPE / POP (Linear Low Density Polyethylene / Polyoxymethylene) composite layer; the D layer is an LLDPE / POP (Linear Low Density Polyethylene / Polyoxymethylene) composite layer; the layer E is an LDPE (Low-Density Polyethylene) layer; the F layer is a TIE layer; the G layer is a PA layer; the H layer is a TIE layer; and the layer I is an LLDPE / LDPE (linear low density polyethylene / low density polyethylene) composite layer. The PE / PA film provided by the invention is prepared by an up-blowing method, has a nine-layer structural design, is high in strength and large in toughness, and also shows excellent flexibility and stability even in a low-temperature environment in winter.

Description

Technical Field

[0001] The present application relates to the field of packaging film material technology, and in particular to a nine-layer upward-blown asymmetric PE / PA soft packaging film and a preparation method thereof. Background Art

[0002] Currently, PE (polyethylene) / PA (polyamide) film has played an important role in many fields such as food packaging and medical packaging due to its excellent barrier properties and outstanding mechanical strength. This film material can not only effectively isolate oxygen, moisture and odor to ensure the freshness and safety of the items in the package, but also has sufficient strength to support various packaging needs, showing extremely high practical value.

[0003] However, despite the excellent performance of PE / PA film at room temperature, its application in low temperature environment faces challenges, especially in the cold winter, when the temperature drops sharply, PE / PA film will become brittle, its toughness will be greatly reduced, and it will be easy to break. This phenomenon not only affects the use effect of the film, but also greatly limits its wide application in cold areas and under low temperature storage conditions. Therefore, how to improve the low temperature resistance of PE / PA film so that it can still maintain good flexibility and strength in low temperature environment has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In order to improve the low temperature resistance of PE / PA film, the present application provides a nine-layer upward-blown asymmetric PE / PA soft packaging film and a preparation method thereof.

[0005] The present application provides a nine-layer upward-blown asymmetric PE / PA soft packaging film, which adopts the following technical solution: A nine-layer upward-blown asymmetric PE / PA soft packaging film, the film comprises A, B, C, D, E, F, G, H, and I layers from top to bottom; wherein the A layer is a PA layer; the B layer is a TIE layer; the C layer is an LLDPE / POP composite layer; the D layer is an LLDPE / POP composite layer; the E layer is an LDPE layer; the F layer is a TIE layer; the G layer is a PA layer; the H layer is a TIE layer; the The I layer is a LLDPE / LDPE composite layer; the mass ratios of the raw materials of the A, B, C, D, E, F, G, H, and I layers are 0.124-0.134: 0.064-0.070: 0.071-0.081: 0.071-0.081: 0.215-0.227: 0.064-0.070: 0.100-0.112: 0.064-0.070: 0.182-0.202.

[0006] By adopting the above technical solution, using a specific nine-layer structure design, and using POP resin to increase flexibility, the problem of PE / PA film becoming brittle at low temperatures was solved while maintaining good mechanical properties.

[0007] Preferably, the mass ratio of the raw materials of the A, B, C, D, E, F, G, H, and I layers is 0.129:0.067:0.076:0.076:0.221:0.067:0.106:0.067:0.192.

[0008] Preferably, each layer A, B, C, D, E, F, G, H, and I comprises the following raw materials in terms of mass percentage: The A layer includes 95-98% PA resin and 2-5% low temperature toughening agent; Layer B includes 100% TIE resin; The C layer includes 65-75% LLDPE resin and 25-35% POP resin; The D layer includes 65-75% LLDPE resin and 25-35% POP resin; The E layer includes 96-99% LDPE resin and 1-4% low temperature toughening agent; The F layer includes 100% TIE resin; The G layer includes 95-98% PA resin and 2-5% low temperature toughening agent; The H layer includes 100% TIE resin; Layer I includes 55-65% LLDPE resin, 35-45% LDPE resin.

[0009] Preferably, each layer A, B, C, D, E, F, G, H, and I comprises the following raw materials in terms of mass percentage: The A layer includes 97% PA resin and 3% low temperature toughening agent; Layer B includes 100% TIE resin; The C layer includes 70% LLDPE resin and 30% POP resin; The D layer includes 70% LLDPE resin and 30% POP resin; The E layer includes 98% LDPE resin and 2% low temperature toughening agent; The F layer includes 100% TIE resin; The G layer includes 97% PA resin and 3% low temperature toughening agent; The H layer includes 100% TIE resin; Layer I includes 60% LLDPE resin, 40% LDPE resin.

[0010] Preferably, the low-temperature resistant toughening agent is EPDM-g-MAH; the EPDM-g-MAH is prepared from the following raw materials in parts by weight: 2-4 parts of EPDM grafted rubber, 70-100 parts of xylene, and 130-190 parts of acetone.

[0011] Preferably, the EPDM rubber graft is prepared from the following raw materials in parts by weight: 50-70 parts of EPDM rubber particles, 1-1.4 parts of maleic anhydride, 0.125-0.175 parts of dicumyl peroxide, 0.1-0.14 parts of antioxidant, and 9.6-12 parts of acetone.

[0012] Preferably, the preparation method of the EPDM-g-MAH comprises the following steps: The EPDM rubber particles, maleic anhydride, dicumyl peroxide and other additives are added to acetone, uniformly mixed and dried, and the mixture is put into a twin-screw extruder for melt extrusion, and pelletized by a pelletizer to obtain an EPDM rubber graft; the EPDM rubber graft is added to xylene, heated to reflux for 2-4 hours, acetone is added, and the refluxed solution is filtered while hot to obtain a precipitate, the precipitate is dried, and EPDM-g-MAH is obtained after purification.

[0013] By adopting the above technical scheme, the present application grafts maleic anhydride onto ethylene propylene diene monomer rubber to obtain a toughening agent EPDM-g-MAH, which has excellent toughness and low-temperature resistance. Adding EPDM-g-MAH to the film raw material can effectively enhance the mechanical strength and low-temperature resistance of the PA resin layer and the LDPE resin layer.

[0014] Preferably, the TIE resin is a mixture of anhydride-modified ethylene-vinyl acetate copolymer and maleic anhydride-grafted modified polyolefin, and the mass ratio of the two is 1:0.7-1.1.

[0015] Preferably, the POP resin is one of Dow 1900 and Dow 1950, or a mixture of the two.

[0016] By adopting the above technical solution, Dow 1900 or Dow 1950 has excellent processing performance, and can still maintain excellent flexibility and toughness at low temperatures, and is not easy to become brittle or cracked. Adding it as POP resin to PE / PA film can enable the PE / PA film to maintain excellent mechanical properties at low temperatures.

[0017] The present application also provides a method for preparing a nine-layer upward-blown asymmetric PE / PA soft packaging film using the following technical solution: A method for preparing a nine-layer upward-blown asymmetric PE / PA soft packaging film comprises the following steps: S1. Weigh the raw materials of layers A, B, C, D, E, F, G, H, and I according to the mass ratio, put the raw materials into the hopper of the nine-layer co-extrusion film blowing machine in turn, set the screw barrel temperature corresponding to the hopper to 210-220°C, and then extrude the base films of layers A, B, C, D, E, F, G, H, and I through screw extrusion; S2. The base films of layers A, B, C, D, E, F, G, H, and I are passed through the die head of a nine-layer co-extrusion film blowing machine under the action of a screw, and are extruded and blown to form finished films. The die head temperature of the nine-layer co-extrusion film blowing machine is set to 210-220°C, and the blowing ratio is 1:1.3-1.5.

[0018] By adopting the above technical solution, the nine-layer co-extrusion blown film mechanism has many advantages such as high process stability, high production efficiency, excellent film performance and convenient operation, and can effectively obtain PE / PA film with excellent mechanical properties and low temperature resistance.

[0019] In summary, the present application includes at least one of the following beneficial technical effects: 1. This application adopts a specific nine-layer structure design, using POP to increase flexibility, solving the problem of PE / PA film becoming brittle at low temperatures, while maintaining good mechanical properties; 2. In the present application, maleic anhydride is grafted onto EPDM rubber to obtain a toughening agent EPDM-g-MAH, which has excellent toughness and low-temperature resistance. Adding EPDM-g-MAH to film raw materials can effectively enhance the mechanical strength and low-temperature resistance of PA resin films and LDPE resin films; 3. The nine-layer co-extrusion blown film mechanism used in this application has many advantages such as high process stability, high production efficiency, excellent film performance and convenient operation. DETAILED DESCRIPTION

[0020] The present application is further described in detail below with reference to the embodiments.

[0021] Preparation Example Preparation of low temperature resistant toughening agent EPDM-g-MAH Preparation Example 1 T1. 50 g of EPDM rubber particles, 1 g of maleic anhydride, 0.125 g of dicumyl peroxide and 0.1 g of antioxidant 1010 were added to 9.6 g of acetone, uniformly mixed and dried, and the mixture was put into a twin-screw extruder, melt-extruded at 200 ° C, and pelletized by a pelletizer to obtain an EPDM rubber graft; T2. Add 2 g of EPDM grafted rubber obtained from T1 into 70 g of xylene, heat and reflux for 2 h, add 130 g of acetone, and then filter the refluxed solution while hot to obtain a precipitate. Dry the precipitate and purify it to obtain EPDM-g-MAH.

[0022] Preparation Example 2 T1. 60 g of EPDM rubber particles, 1.2 g of maleic anhydride, 0.15 g of dicumyl peroxide and 0.12 g of antioxidant 1010 were added to 10.8 g of acetone, uniformly mixed and dried, and the mixture was put into a twin-screw extruder, melt-extruded at 200 ° C, and pelletized by a pelletizer to obtain an EPDM rubber graft; T2. Add 3 g of EPDM grafted rubber obtained by T1 into 85 g of xylene, heat and reflux for 3 h, add 160 g of acetone, and then filter the refluxed solution while hot to obtain a precipitate. Dry the precipitate and purify it to obtain EPDM-g-MAH.

[0023] Preparation Example 3 T1. 70 g of EPDM rubber particles, 1.4 g of maleic anhydride, 0.175 g of dicumyl peroxide and 0.14 g of antioxidant 1010 were added to 12 g of acetone, uniformly mixed and dried, and the mixture was put into a twin-screw extruder, melt-extruded at 200 ° C, and pelletized by a pelletizer to obtain an EPDM rubber graft; T2. Add 4 g of EPDM grafted rubber obtained from T1 into 100 g of xylene, heat and reflux for 4 h, add 190 g of acetone, and then filter the refluxed solution while hot to obtain a precipitate. Dry the precipitate and purify it to obtain EPDM-g-MAH. Example

[0024] Example 1 A nine-layer upward-blown asymmetric PE / PA soft packaging film, comprising A, B, C, D, E, F, G, H, and I layers from top to bottom; wherein the A layer is a PA layer; the B layer is a TIE layer; the C layer is an LLDPE / POP composite layer; the D layer is an LLDPE / POP composite layer; the E layer is an LDPE layer; the F layer is a TIE layer; the G layer is a PA layer; the H layer is a TIE layer; the I layer is an LLDPE / LDPE composite layer; the masses of the raw materials of the A, B, C, D, E, F, G, H, and I layers are 0.124 g, 0.064 g, 0.071 g, 0.071 g, 0.215 g, 0.064 g, 0.100 g, 0.064 g, and 0.182 g, respectively; The A, B, C, D, E, F, G, H, and I layers respectively include the following raw materials by mass percentage: The A layer includes 95% PA resin and 5% low temperature toughening agent; Layer B includes 100% TIE resin; The C layer includes 65% LLDPE resin and 35% POP resin; The D layer includes 65% LLDPE resin and 35% POP resin; The E layer includes 96% LDPE resin and 4% low temperature toughening agent; The F layer includes 100% TIE resin; The G layer includes 95% PA resin and 5% low temperature toughening agent; The H layer includes 100% TIE resin; Layer I includes 55% LLDPE resin and 45% LDPE resin; The low temperature toughening agent used in this embodiment is from Preparation Example 1; the POP resin used is Dow 1900; the TIE resin used is a mixture of anhydride-modified ethylene-vinyl acetate copolymer and maleic anhydride-grafted modified polyolefin, the mass ratio of the two being 1:0.7; The method for preparing the nine-layer upward blowing asymmetric PE / PA soft packaging film adopts a nine-layer co-extrusion upward blowing method to prepare the film, comprising the following steps: S1. The above raw materials are sequentially placed in the hopper of a nine-layer co-extrusion film blowing machine, the screw barrel temperature corresponding to the hopper is set to 210°C, and then the base films A, B, C, D, E, F, G, H, and I layers are obtained by screw extrusion; S2. The base films of layers A, B, C, D, E, F, G, H, and I are passed through the die head of a nine-layer co-extrusion film blowing machine under the action of a screw, and are extruded and blown to form finished films. The die head temperature of the nine-layer co-extrusion film blowing machine is set to 210°C, and the blowing ratio is 1:1.3.

[0025] Example 2 A nine-layer upward-blown asymmetric PE / PA soft packaging film, comprising A, B, C, D, E, F, G, H, and I layers from top to bottom; wherein the A layer is a PA layer; the B layer is a TIE layer; the C layer is an LLDPE / POP composite layer; the D layer is an LLDPE / POP composite layer; the E layer is an LDPE layer; the F layer is a TIE layer; the G layer is a PA layer; the H layer is a TIE layer; the I layer is an LLDPE / LDPE composite layer; the masses of the raw materials of the A, B, C, D, E, F, G, H, and I layers are 0.129 g, 0.067 g, 0.076 g, 0.076 g, 0.221 g, 0.067 g, 0.106 g, 0.067 g, and 0.192 g, respectively; The A, B, C, D, E, F, G, H, and I layers respectively include the following raw materials by mass percentage: The A layer includes 97% PA resin and 3% low temperature toughening agent; Layer B includes 100% TIE resin; The C layer includes 70% LLDPE resin and 30% POP resin; The D layer includes 70% LLDPE resin and 30% POP resin; The E layer includes 98% LDPE resin and 2% low temperature toughening agent; The F layer includes 100% TIE resin; The G layer includes 97% PA resin and 3% low temperature toughening agent; The H layer includes 100% TIE resin; Layer I includes 60% LLDPE resin and 40% LDPE resin; The low temperature toughening agent used in this embodiment is from Preparation Example 1; the POP resin used is Dow 1900; the TIE resin used is a mixture of anhydride-modified ethylene-vinyl acetate copolymer and maleic anhydride-grafted modified polyolefin, the mass ratio of the two being 1:0.7; The method for preparing the nine-layer upward blowing asymmetric PE / PA soft packaging film adopts a nine-layer co-extrusion upward blowing method to prepare the film, comprising the following steps: S1. The above raw materials are sequentially placed into the hopper of a nine-layer co-extrusion film blowing machine, the screw barrel temperature corresponding to the hopper is set to 215°C, and then the base films A, B, C, D, E, F, G, H, and I layers are obtained by screw extrusion; S2. The base films of layers A, B, C, D, E, F, G, H, and I are passed through the die head of a nine-layer co-extrusion film blowing machine under the action of a screw, and are extruded and blown to form finished films. The die head temperature of the nine-layer co-extrusion film blowing machine is set to 215°C, and the blowing ratio is 1:1.4.

[0026] Example 3 A nine-layer upward-blown asymmetric PE / PA soft packaging film, comprising A, B, C, D, E, F, G, H, and I layers from top to bottom; wherein the A layer is a PA layer; the B layer is a TIE layer; the C layer is an LLDPE / POP composite layer; the D layer is an LLDPE / POP composite layer; the E layer is an LDPE layer; the F layer is a TIE layer; the G layer is a PA layer; the H layer is a TIE layer; the I layer is an LLDPE / LDPE composite layer; the masses of the raw materials of the A, B, C, D, E, F, G, H, and I layers are 0.134 g, 0.070 g, 0.081 g, 0.081 g, 0.227 g, 0.070 g, 0.112 g, 0.070 g, and 0.202 g, respectively; The A, B, C, D, E, F, G, H, and I layers respectively include the following raw materials by mass percentage: The A layer includes 98% PA resin and 2% low temperature toughening agent; Layer B includes 100% TIE resin; The C layer includes 75% LLDPE resin and 25% POP resin; The D layer includes 75% LLDPE resin and 25% POP resin; The E layer includes 99% LDPE resin and 1% low temperature toughening agent; The F layer includes 100% TIE resin; The G layer includes 98% PA resin and 2% low temperature toughening agent; The H layer includes 100% TIE resin; Layer I includes 65% LLDPE resin and 35% LDPE resin; The low temperature toughening agent used in this embodiment is from Preparation Example 1; the POP resin used is Dow 1900; the TIE resin used is a mixture of anhydride-modified ethylene-vinyl acetate copolymer and maleic anhydride-grafted modified polyolefin, the mass ratio of the two being 1:0.7; The method for preparing the nine-layer upward blowing asymmetric PE / PA soft packaging film adopts a nine-layer co-extrusion upward blowing method to prepare the film, comprising the following steps: S1. The above raw materials are sequentially placed in the hopper of a nine-layer co-extrusion film blowing machine, the screw barrel temperature corresponding to the hopper is set to 220°C, and then the base film A, B, C, D, E, F, G, H, and I layers are obtained by screw extrusion; S2. The base films of layers A, B, C, D, E, F, G, H, and I are passed through the die head of a nine-layer co-extrusion film blowing machine under the action of a screw, and are extruded and blown to form finished films. The die head temperature of the nine-layer co-extrusion film blowing machine is set to 220°C, and the blowing ratio is 1:1.5.

[0027] Example 4 The difference between Example 4 and Example 1 is that the low-temperature resistant toughening agent used in Example 4 comes from Preparation Example 2.

[0028] Example 5 The difference between Example 5 and Example 1 is that the low-temperature resistant toughening agent used in Example 5 comes from Preparation Example 3.

[0029] Example 6 The difference between Example 6 and Example 1 is that the POP resin used in Example 6 is a mixture of Dow 1900 and Dow 1950, and the mass ratio of the two is 1:1.

[0030] Example 7 The difference between Example 7 and Example 1 is that the mass ratio of the TIE resin anhydride-modified ethylene-vinyl acetate copolymer and the maleic anhydride (MAH) graft-modified polyolefin used in Example 7 is 1:0.9.

[0031] Example 8 The difference between Example 8 and Example 1 is that the mass ratio of the TIE resin anhydride-modified ethylene-vinyl acetate copolymer and the maleic anhydride (MAH) graft-modified polyolefin used in Example 8 is 1:1.1.

[0032] Example 9 The difference between Example 9 and Example 1 is that the mass ratio of the TIE resin anhydride-modified ethylene-vinyl acetate copolymer and the maleic anhydride (MAH) graft-modified polyolefin used in Example 9 is 1:0.5.

[0033] Example 10 The difference between Example 10 and Example 1 is that the mass ratio of the TIE resin anhydride-modified ethylene-vinyl acetate copolymer and the maleic anhydride (MAH) graft-modified polyolefin used in Example 10 is 1:1.3.

[0034] Embodiment 11 The difference between Example 11 and Example 1 is that no low-temperature resistant toughening agent is added to the raw materials of layer A, layer E, and layer G in Example 11.

[0035] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the masses of the raw materials of layers A, B, C, D, E, F, G, H, and I in Comparative Example 1 are 0.119 g, 0.061 g, 0.066 g, 0.066 g, 0.209 g, 0.061 g, 0.094 g, 0.061 g, and 0.172 g, respectively.

[0036] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the masses of the raw materials of layers A, B, C, D, E, F, G, H, and I in Comparative Example 2 are 0.139 g, 0.073 g, 0.086 g, 0.086 g, 0.233 g, 0.073 g, 0.118 g, 0.073 g, and 0.212 g, respectively.

[0037] Performance testing 1. Using GB / T 1040.3-2006 "Determination of tensile properties of plastics Part 3 Film / sheet test conditions", the tensile strength and elongation at break of the nine-layer upblown asymmetric PE / PA soft packaging films obtained in Examples 1-11 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0038] 2. The low-temperature impact strength of the nine-layer upblown asymmetric PE / PA soft packaging films obtained in Examples 1-11 and Comparative Examples 1-2 at -30°C was tested using GB / T 9639-2008 "Test method for impact resistance of plastic films and sheets - free-falling dart method". The results are shown in Table 1.

[0039] The specific test results are as follows: Table 1 Performance test results It can be seen from the test results in Table 1 that the nine-layer upward-blown asymmetric PE / PA soft packaging film and the preparation method thereof provided in the present application have high tensile strength and elongation at break, indicating that the nine-layer upward-blown asymmetric PE / PA soft packaging film provided in the present application has strong mechanical strength; the film has high low-temperature resistance and impact strength at -30°C, indicating that the nine-layer upward-blown asymmetric PE / PA soft packaging film provided in the present application has excellent low-temperature resistance.

[0040] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A nine-layer upward-blown asymmetric PE / PA soft packaging film, characterized in that: The film comprises A, B, C, D, E, F, G, H, and I layers from top to bottom; wherein, the A layer is a PA layer; the B layer is a TIE layer; the C layer is an LLDPE / POP composite layer; the D layer is an LLDPE / POP composite layer; the E layer is an LDPE layer; the F layer is a TIE layer; the G layer is a PA layer; the H layer is a TIE layer; the I layer is an LLDPE / LDPE composite layer; the mass ratio of the raw materials of the A, B, C, D, E, F, G, H, and I layers is 0.124-0.134: 0.064-0.070: 0.071-0.081: 0.071-0.081: 0.215-0.227: 0.064-0.070: 0.100-0.112: 0.064-0.070: 0.182-0.

202.

2. The nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 1, characterized in that: The mass ratio of the raw materials of the A, B, C, D, E, F, G, H, and I layers is 0.129: 0.067: 0.076: 0.076: 0.221: 0.067: 0.106: 0.067: 0.

192.

3. The nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 1, characterized in that: The A, B, C, D, E, F, G, H, and I layers respectively include the following raw materials by mass percentage: The A layer includes 95-98% PA resin and 2-5% low temperature toughening agent; Layer B includes 100% TIE resin; The C layer includes 65-75% LLDPE resin and 25-35% POP resin; The D layer includes 65-75% LLDPE resin and 25-35% POP resin; The E layer includes 96-99% LDPE resin and 1-4% low temperature toughening agent; The F layer includes 100% TIE resin; The G layer includes 95-98% PA resin and 2-5% low temperature toughening agent; The H layer includes 100% TIE resin; Layer I includes 55-65% LLDPE resin, 35-45% LDPE resin.

4. The nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 3, characterized in that: The A, B, C, D, E, F, G, H, and I layers respectively include the following raw materials by mass percentage: The A layer includes 97% PA resin and 3% low temperature toughening agent; Layer B includes 100% TIE resin; The C layer includes 70% LLDPE resin and 30% POP resin; The D layer includes 70% LLDPE resin and 30% POP resin; The E layer includes 98% LDPE resin and 2% low temperature toughening agent; The F layer includes 100% TIE resin; The G layer includes 97% PA resin and 3% low temperature toughening agent; The H layer includes 100% TIE resin; Layer I includes 60% LLDPE resin and 40% LDPE resin.

5. A nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 3 or 4, characterized in that: The low temperature resistant toughening agent is EPDM-g-MAH; the EPDM-g-MAH is prepared from the following raw materials in parts by weight: 2-4 parts of EPDM grafted rubber, 70-100 parts of xylene, and 130-190 parts of acetone.

6. The nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 5, characterized in that: The EPDM rubber graft is prepared from the following raw materials in parts by weight: 50-70 parts of EPDM rubber particles, 1-1.4 parts of maleic anhydride, 0.125-0.175 parts of dicumyl peroxide, 0.1-0.14 parts of antioxidant, and 9.6-12 parts of acetone.

7. A nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 5 or 6, characterized in that: The preparation method of the EPDM-g-MAH comprises the following steps: Adding EPDM rubber particles, maleic anhydride, dicumyl peroxide and an antioxidant into acetone, uniformly mixing and drying, putting the mixture into a twin-screw extruder for melt extrusion, and pelletizing it through a pelletizer to obtain an EPDM rubber graft; The EPDM grafted product is added to xylene, heated under reflux for 2-4 hours, and then acetone is added. The refluxed solution is filtered while hot to obtain a precipitate. The precipitate is dried and purified to obtain EPDM-g-MAH.

8. The nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 3 or 4, characterized in that: The TIE resin is a mixture of anhydride-modified ethylene-vinyl acetate copolymer and maleic anhydride-grafted modified polyolefin, and the mass ratio of the two is 1:0.7-1.

1.

9. The nine-layer upward-blown asymmetric PE / PA soft packaging film according to claim 3 or 4, characterized in that: The POP resin is one of Dow 1900 and Dow 1950 or a mixture of the two.

10. A method for preparing a nine-layer upward-blown asymmetric PE / PA soft packaging film according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Weigh the raw materials of layers A, B, C, D, E, F, G, H, and I according to the mass ratio, put the raw materials into the hopper of the nine-layer co-extrusion film blowing machine in turn, set the screw barrel temperature corresponding to the hopper to 210-220°C, and then extrude the base films of layers A, B, C, D, E, F, G, H, and I through screw extrusion; S2. The base films of layers A, B, C, D, E, F, G, H, and I are passed through the die head of a nine-layer co-extrusion film blowing machine under the action of a screw, and are extruded and blown to form finished films. The die head temperature of the nine-layer co-extrusion film blowing machine is set to 210-220°C, and the blowing ratio is 1:1.3-1.5.

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