CN108724877B - Multilayer polymer film and method for producing same - Google Patents

Abstract

The present invention provides a multilayer polymer film and a preparation method thereof, comprising at least one polar engineering plastic layer, at least one non-polar polyolefin layer, and an adjacent polar engineering plastic layer and a non-polar engineering plastic layer. The compatibility modification layer between the polar polyolefin layers, the compatibility modification layer comprises polar engineering plastics and copolymerization-modified polyolefin. The invention adopts the non-polar polyolefin polymer and the common polar engineering plastics as basic materials, and solves the problem of poor compatibility between the polar engineering plastics and the non-polar polyolefin polymer by adding a compatibility modification layer. The interlayer compatibility of multilayer polymer films is improved. Compared with the traditional polyolefin film, the multi-layer polymer film prepared by the invention not only has higher mechanical strength and weather resistance, but also has better corrosion resistance and water resistance compared with the polar engineering plastic film.

Description

Multilayer polymer film and method of making the same

technical field

The present invention relates to the field of multilayer polymer films, and more particularly, to a multilayer polymer film and a preparation method thereof.

Background technique

As we all know, plastic film has been widely used in food packaging, agricultural greenhouses, fish farming, industrial packaging, outdoor facilities and other fields. Traditional polyolefin plastics (such as polyethylene, polypropylene, etc.) film products have the advantages of low cost and easy molding, but generally have poor mechanical properties and weather resistance. However, if polymer materials with higher strength and weather resistance are used (such as polyethylene terephthalate (PET), nylon (PA), polymethyl methacrylate (PMMA), etc.), the cost of raw materials will be significantly increased , and water resistance, corrosion resistance, surface properties and other shortcomings limit the application.

In order to balance this contradiction, the composite plastic film can be formed by layered co-extrusion of a variety of polymers, so that the two polymers can complement each other in performance. However, the polar engineering plastics have poor compatibility with non-polar polyolefins, and the formed composite film is easily peeled off and cannot be used, thus limiting the choice of core polymer and the mechanical properties of the composite film. properties such as strength and weatherability.

SUMMARY OF THE INVENTION

In view of the problems existing in the background technology, the object of the present invention is to provide a multilayer polymer film and a preparation method thereof, which can improve the compatibility of polar engineering plastics and non-polar polyolefin polymers, and can improve the compatibility of polar engineering plastics with non-polar polyolefin polymers. The layer co-extrusion method produces a multi-layer polymer film with the characteristics of both polar engineering plastic films and polyolefin films. It has excellent comprehensive properties, high mechanical strength, good weather resistance, water resistance and corrosion resistance. Etc.

In order to achieve the above object, in a first aspect, the present invention provides a multilayer polymer film, which comprises at least one polar engineering plastic layer, at least one nonpolar polyolefin layer, and polar The compatibility modification layer between the engineering plastic layer and the non-polar polyolefin layer, the compatibility modification layer comprises polar engineering plastics and copolymerization-modified polyolefin.

Further, the multilayer polymer film has a five-layer structure, and the five-layer structure includes: a polyolefin layer-compatibility modified layer-polar engineering plastic layer-compatibility modified layer-polyolefin layer.

Further, the multilayer polymer film has a seven-layer structure, and the seven-layer structure includes: functionalized surface layer-polyolefin layer-compatible modified layer-polar engineering plastic layer-compatible modified layer-polyolefin layer - A functionalized surface layer, the functionalized surface layer includes at least one of a hydrophilic modified layer, an anti-ultraviolet layer, an antistatic layer, and a matte layer.

Further, the multilayer polymer film has a nine-layer structure, and the nine-layer structure includes: functionalized surface layer-compatibility modification layer-polyolefin layer-compatibility modification layer-polar engineering plastic layer-compatibility modification layer. Properties layer-polyolefin layer-compatible modified layer-functionalized surface layer, the functionalized surface layer includes at least one of a hydrophilic modified layer, an anti-ultraviolet layer, an antistatic layer, and a matte layer.

In order to achieve the above object, in a second aspect, the present invention provides a method for preparing a multilayer polymer film for preparing the multilayer polymer film according to the first aspect of the present invention, which comprises the steps: (1) Mix polyolefin, initiator and compatibility modifier in proportion, and carry out copolymerization modification to obtain copolymerization-modified polyolefin particles; (2) mixing polar engineering plastics and copolymerization-modified polyolefin particles in proportion to obtain (3) Add the compatible modified material, polyolefin and polar engineering plastics to different extruders in the multi-layer co-extrusion molding equipment respectively, and extrude them at the same time. molding to obtain a multilayer polymer film.

Further, the polyolefin includes at least one of polyethylene, polypropylene, polybutene, and ethylene propylene copolymer; the polar engineering plastics include at least nylon, polyethylene terephthalate, polyethylene terephthalate, and polyethylene terephthalate. One of butylene phthalate, polymethyl methacrylate, thermoplastic polyester elastomer, thermoplastic polyamide elastomer, polycarbonate or its recycled resin; the initiator includes at least diphenyl peroxide One of acyl, di-tert-butyl peroxide, di-tert-butyl peroxide, potassium persulfate, diisopropyl peroxydicarbonate, hydrogen peroxide, azobisisobutyronitrile or azobisisoheptanenitrile ; The compatibility modifier includes at least one of maleic anhydride, bismaleimide, glycidyl methacrylate, vinyl silane, maleic anhydride-acrylic acid, polyethylene-glycidyl methacrylate kind.

Further, in step (1), the weight ratio of the polyolefin, the initiator and the compatibility modifier is 100:0.1-0.5:1-4.

Further, in step (2), a chain extender is added to blend with polar engineering plastics and copolymerized modified polyolefin, and the chain extender at least comprises 1,4-butanediol, 1,6-hexanediol, Glycerin, Trimethylolpropane, Diethylene Glycol, Triethylene Glycol, Neopentyl Glycol, Sorbitol, Diethylaminoethanol, Ethylenediamine, N,N-Dihydroxy(diisopropyl)aniline, Hydroquinone- One of bis(β-hydroxyethyl) ether and styrene-acrylonitrile-glycidyl methacrylate terpolymer.

Further, in step (2), the compatible modified material is further subjected to extrusion granulation.

Further, in step (3), the multi-layer co-extrusion molding equipment is a co-extrusion blow molding or co-extrusion casting equipment.

The beneficial effects of the present invention are as follows:

The invention adopts the non-polar polyolefin polymer and the common polar engineering plastics as basic materials, and solves the problem of poor compatibility between the polar engineering plastics and the non-polar polyolefin polymer by adding a compatibility modification layer. The interlayer compatibility of multilayer polymer films is improved.

Compared with the traditional polyolefin film, the multi-layer polymer film prepared by the invention not only has higher mechanical strength and weather resistance, but also has better corrosion resistance and water resistance compared with the polar engineering plastic film.

The polar engineering plastic used in the present invention can be recycled polar engineering plastic film or multi-layer plastic film material containing polar engineering plastic, which is green and environmentally friendly, and greatly reduces the cost of raw materials.

The modification and forming method used in the present invention does not need to add special equipment, is easy to implement and operate, and can be produced on the existing general film forming equipment.

The multi-layer polymer film of the present invention can be widely used in food packaging, agricultural greenhouses, fish farming, industrial packaging, outdoor facilities and other fields.

Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below.

Many specific details are set forth in the following description to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can do so without departing from the connotation of the present invention. Similar promotion, therefore, the present invention is not limited by the specific embodiments disclosed below.

First, the multilayer polymer film according to the first aspect of the present invention will be described.

The multilayer polymer film according to the first aspect of the present invention comprises at least one polar engineering plastic layer, at least one non-polar polyolefin layer, and an adjacent polar engineering plastic layer and non-polar polyolefin layer interposed therebetween A compatibility modified layer between the two, the compatibility modified layer comprises polar engineering plastics and copolymerized modified polyolefin.

In one embodiment, the multi-layer polymer film has a three-layer structure, and the three-layer structure includes: a polyolefin layer-compatibility modification layer-polar engineering plastic layer.

In one embodiment, the multi-layer polymer film has a four-layer structure, and the four-layer structure includes: a polyolefin layer - a compatibility modification layer - a polar engineering plastic layer - a functionalized surface layer, the functionalized surface layer At least one of a hydrophilic modified layer, an anti-ultraviolet layer, an antistatic layer and a matte layer is included. Different functionalized surface layers have different functions and functions. In practice, they should be selected according to actual needs.

In one embodiment, the multi-layer polymer film has a five-layer structure, and the five-layer structure includes: a polyolefin layer-compatible modified layer-polar engineering plastic layer-compatible modified layer-polyolefin layer. In another embodiment, the multi-layer polymer film has a five-layer structure, and the five-layer structure includes: polar engineering plastic layer-compatible modified layer-polyolefin layer-compatible modified layer-polar engineering plastic Floor.

In one embodiment, the multi-layer polymer film has a six-layer structure, and the six-layer structure includes: polyolefin layer-compatible modified layer-polar engineering plastic layer-compatible modified layer-polyolefin layer-function The functionalized surface layer includes at least one of a hydrophilic modified layer, an anti-ultraviolet layer, an antistatic layer, and a matte layer.

In one embodiment, the multilayer polymer film has a seven-layer structure, and the seven-layer structure includes: functionalized surface layer-polyolefin layer-compatible modified layer-polar engineering plastic layer-compatible modified layer- Polyolefin layer-functionalized surface layer, the functionalized surface layer includes at least one of a hydrophilic modified layer, an anti-ultraviolet layer, an antistatic layer, and a matte layer.

In one embodiment, the multilayer polymer film has a nine-layer structure, and the nine-layer structure includes: polyolefin layer-compatible modified layer-polar engineering plastic layer-compatible modified layer-polyolefin layer-phase Compatibility modification layer - polar engineering plastic layer - compatibility modification layer - polyolefin layer.

In another embodiment, the multi-layer polymer film has a nine-layer structure, and the nine-layer structure includes: functionalized surface layer-compatible modified layer-polyolefin layer-compatible modified layer-polar engineering plastic layer - Compatibility modification layer - Polyolefin layer - Compatibility modification layer - Functionalized surface layer, the functionalized surface layer includes at least one of a hydrophilic modified layer, an anti-ultraviolet layer, an antistatic layer, and a matte layer .

The number of layers of the multi-layer polymer film is not limited, and the functionalized surface layer is not limited. In practical application, selection is made according to specific performance and functional requirements, as long as the concept of the present invention is satisfied, it is within the protection scope of the present invention.

Next, a method for producing the multilayer polymer film according to the second aspect of the present invention will be described.

The method for preparing the multilayer polymer film according to the second aspect of the present invention is used to prepare the multilayer polymer film according to the first aspect of the present invention, comprising the steps of: (1) mixing polyolefins (which can be powder or granules) in proportions , initiator and compatibility modifier, perform block or graft copolymerization modification to obtain copolymerized modified polyolefin particles; (2) mix polar engineering plastics (which can be powder or particles) and copolymerization modified polyolefin particles in proportion; (3) Compatible modifier, polyolefin (can be powder or granule), polar engineering plastic (can be powder or granules) are separately fed into different extruders in the multi-layer co-extrusion molding equipment, and extruded at the same time to obtain a multi-layer polymer film.

In one embodiment, the polyolefin includes at least one of polyethylene, polypropylene, polybutene, and ethylene-propylene copolymer.

In one embodiment, the polar engineering plastics at least include nylon (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polymethyl methacrylate Ester (PMMA), Thermoplastic Polyester Elastomer (TPEE), Thermoplastic Polyamide Elastomer (TPAE), Polycarbonate (PC) or one of its recycled resins.

In one embodiment, the initiator includes at least dibenzoyl peroxide (BPO), di-tert-butyl peroxide, di-tert-butyl peroxide, potassium persulfate, diisopropyl peroxydicarbonate, One of hydrogen oxide, azobisisobutyronitrile or azobisisoheptanenitrile.

In one embodiment, the compatibility modifier includes at least maleic anhydride, bismaleimide, glycidyl methacrylate, vinyl silane, maleic anhydride-acrylic acid, polyethylene-methacrylic acid glycidyl One of the glycerides.

In one embodiment, in step (1), the weight ratio of the polyolefin, the initiator and the compatibility modifier is 100:0.1-0.5:1-4.

In one embodiment, in step (2), the compatible modified material is further subjected to extrusion granulation. Extrusion granulation can be carried out using a twin-screw extruder.

In one embodiment, in step (2), a chain extender is added to blend with polar engineering plastics and copolymerized modified polyolefin, and the chain extender at least includes 1,4-butanediol (BDO), 1 , 6-hexanediol, glycerin, trimethylolpropane, diethylene glycol (DEG), triethylene glycol, neopentyl glycol (NPG), sorbitol, diethylaminoethanol (DEAE), ethylenediamine (DA) , N,N-dihydroxy(diisopropyl)aniline (HPA), hydroquinone-di(β-hydroxyethyl) ether (HQEE), styrene-acrylonitrile-glycidyl methacrylate terpolymer (SAG) one.

In one embodiment, in step (3), the multi-layer co-extrusion molding equipment is a co-extrusion blow molding or co-extrusion casting equipment. The amount of extrusion can be the same or a certain ratio to obtain a multilayer polymer film with the same thickness or a certain ratio of each layer.

Hereinafter, the preparation method of the photochemically hydrophilic modified polymer film of the present invention will be described in detail with reference to specific examples.

Example 1

(1) Raw material ratio of compatible modified material:

Linear low density polyethylene: 100 parts, polymethyl methacrylate: 100 parts, dibenzoyl peroxide: 0.5 parts, glycidyl methacrylate: 2 parts.

(2) using dibenzoyl peroxide as an initiator, the linear low-density polyethylene particles and glycidyl methacrylate are mixed with a high-speed mixer at a rotating speed of 1000 rev/min, under the condition of a temperature of 50 ° C for 15 minutes, Add to the intermeshing co-rotating twin-screw extruder, extrude and granulate to obtain graft-modified linear low-density polyethylene particles; then blend with polymethyl methacrylate to obtain a compatible modified material for molding phase Modified layer. The temperature of each zone of the extruder: 150 °C in the first zone, 170 °C in the second zone, 180 °C in the third zone, and 175 °C in the fourth zone;

(3) The compatible modified material, linear low-density polyethylene particles, and polymethyl methacrylate particles are respectively added to different extruders in the five-layer co-extrusion blow molding equipment, and extruded at the same time to obtain a linear structure. Low density polyethylene-compatible modified layer-polymethyl methacrylate-compatible modified layer-linear low density polyethylene multilayer co-extrusion film, the thickness ratio of each layer is 1:1:1:1: 1. The total thickness is 0.1mm.

Example 2

(1) Raw material ratio of compatible modified material:

Polypropylene: 100 parts, polyethylene terephthalate recycled material: 150 parts, azobisisobutyronitrile: 0.1 part, maleic anhydride: 4 parts, glycidyl methacrylate: 4.5 parts.

(2) After dissolving azobisisobutyronitrile and maleic anhydride with acetone, mix with polypropylene pellets in a high-speed mixer, rotating speed 1000 rev/min, temperature 50 ℃, after mixing and stirring for 15 minutes, Add to the intermeshing co-rotating twin-screw extruder, extrude and granulate to obtain graft-modified polypropylene particles; the temperature of each zone of the extruder: 150°C in the first zone, 170°C in the second zone, 180°C in the third zone, and 4th zone. 175℃, head 170℃.

(3) then the polyethylene terephthalate recycling material and glycidyl methacrylate (GMA) are blended, and the meshing co-rotating twin-screw extruder is extruded and granulated to obtain modified polyparaphenylene Ethylene glycol diformate recycled material. The temperature of each zone of the extruder: 250°C for the first zone, 265°C for the second zone, 270°C for the third zone, 270°C for the fourth zone, and 265°C for the die head. The modified polyethylene terephthalate recycled material is mixed with the graft-modified polypropylene particles to obtain a compatible modified material for forming a compatible modified layer.

(4) The compatible modified material, polypropylene particles, and modified polyethylene terephthalate recycled material are respectively added to different extruders in the five-layer co-extrusion casting equipment, and extruded at the same time. A five-layer co-extruded film with a structure of polypropylene-compatible modified layer-polyethylene terephthalate-compatible modified layer-polypropylene was obtained, and the thickness ratio of each layer was 1:1:1:1 :1, the total thickness is 0.1mm.

Example 3

(1) Raw material ratio of compatible modified material:

Low density polyethylene: 100 parts, nylon 6: 300 parts, diisopropyl peroxydicarbonate: 0.2 parts, maleic anhydride: 1 part, polyethylene wax: 1 part, styrene grafted maleic anhydride random copolymerization Items: 5 servings.

(2) The initiator diisopropyl peroxydicarbonate, polyethylene wax and maleic anhydride are in the high-speed mixer, under the condition of rotating speed 1000 rev/min and temperature 150 ℃, after mixing and stirring for 45 minutes, press The proportion of low-density polyethylene particles, nylon 6 particles and styrene grafted maleic anhydride random copolymer was added and mixed for 10 minutes. Finally, the mixture was added to the meshing co-rotating twin-screw extruder, and extruded and pelletized to obtain a compatible modification. The temperature of each zone of the extruder: 250°C for the first zone, 270°C for the second zone, 280°C for the third zone, 275°C for the fourth zone, and 260°C for the die head.

(3) The compatible modified material, low density polyethylene particles and nylon 6 particles are respectively added to different extruders in the five-layer co-extrusion casting equipment, and extruded at the same time to obtain a low density polyethylene-phase structure. Compatibility modification layer-nylon 6-compatible modification layer-low density polyethylene five-layer co-extrusion film, the thickness ratio of each layer is 1:1:2:1:1, and the total thickness is 0.1mm.

Example 4

The same as the preparation method of the compatible modified material of Example 2, the difference is:

Add the blend of compatible modified material, polypropylene particles, polypropylene particles and antistatic masterbatch (AT4082PP) with a weight ratio of 3:1, and the modified polyethylene terephthalate particle recycled material respectively. Different extruders in seven-layer co-extrusion casting equipment to obtain the structure of antistatic polypropylene-polypropylene-compatible modified layer-polyethylene terephthalate-compatible modified layer-polypropylene - Seven-layer co-extruded film of antistatic polypropylene layer, the thickness ratio of each layer is 0.5:1:1:1:1:1:0.5, and the total thickness is 0.1mm.

Example 5

The same as the preparation method of the compatible modified material of Example 3, the difference is:

The compatible modified material, low density polyethylene particles and nylon 6 particles are respectively added to different extruders in the nine-layer co-extrusion casting equipment, and extruded at the same time to obtain the structure of low density polyethylene-compatible modification Layer-Nylon 6-Compatible Modified Layer-Low Density Polyethylene-Compatible Modified Layer-Nylon 6-Compatible Modified Layer-Low Density Polyethylene Nine-layer co-extruded film, the thickness ratio of each layer is 1:1 :1:1:2:1:1:1:1, the total thickness is 0.15mm.

Comparative Example 1

Pure linear low density polyethylene film, thickness 0.1mm.

Comparative Example 2

Polyethylene terephthalate film, thickness 0.1mm.

Comparative Example 3

Except that the compatibility modification layer is not used, other preparation processes are the same as those in Example 1.

Performance Testing

1. Determination of tensile strength and elongation at break

According to the national standard "Determination of Tensile Properties of Plastics" (GB\T1040.3-2006), Part 3, test conditions for films and sheets: dumbbell-shaped splines with a length of 150mm, a narrow parallel width of 10mm, and a tensile speed of 50mm/min, room temperature 25℃.

2. Determination of tear strength

Refer to GB/T 16578-1996 "Test method for tear resistance of plastic films and sheets", trouser-shaped tearing method, and the tensile speed is 200±20mm/min.

3. Determination of peel strength

The film sample is 15mm wide and 200mm long; the polar engineering plastic layer and the polyolefin layer are peeled off in advance in the length direction of the sample, T-type peeling is performed, the average peeling force (N) is measured, and the test speed is 300mm/min.

4. Determination of oxygen transmission rate

Refer to the national standard "Test Method for Gas Permeability of Plastic Films and Sheets" (GB/T1038-2000).

5. Thermal aging test

Referring to the national standard "Plastic Thermal Aging Test Method" (GB/T7141-2008), the tensile strength was tested in a gravity convection thermal aging box at a temperature of 90 °C and an aging time of 24 hours.

The performance test results are shown in Table 1.

Table 1 Performance test results

It can be seen from the above examples that the compatible modified layer used in the present invention significantly improves the adhesive force between the polyolefin layer and the engineering plastic layer; the engineering plastic and polyolefin composite multilayer polymer film prepared by co-extrusion and Compared with pure polyolefin film, it has higher mechanical strength, and compared with pure engineering plastic film, the tensile strength does not decrease significantly after aging, and has better aging resistance; secondly, the polar engineering plastic used in the present invention can be It is a polar engineering plastic film recycling material or a multi-layer polar engineering plastic film recycling material containing polar engineering plastics, which belongs to waste recycling, which is not only environmentally friendly, but also reduces the cost of raw materials; in addition, the modification and molding used in the present invention are The method can be produced on the existing general film forming equipment, is simple and practical, and does not need to add special equipment.

The multi-layer polymer film of the present invention can be widely used in food packaging, agricultural greenhouses, fish farming, industrial packaging, outdoor facilities and other fields.

While some specific embodiments of the present invention have been described in detail by way of example, those skilled in the art will appreciate that the above examples are provided for illustration only and not for the purpose of limiting the scope of the invention. Those skilled in the art will appreciate that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the invention is defined by the appended claims.

Claims (6)

1. a multilayer polymer film is characterized in that, comprises at least one layer of polar engineering plastics, at least one layer of non-polar polyolefin layer, and between adjacent polar engineering plastic layer and non-polar polyolefin layer a compatibility modification layer between the layers, the compatibility modification layer comprises polar engineering plastics and copolymerized modified polyolefin; The multi-layer polymer film has a five-layer, seven-layer or nine-layer structure, and the five-layer structure includes: polyolefin layer-compatible modified layer-polar engineering plastic layer-compatible modified layer-polyolefin layer; seven The layer structure includes: functionalized surface layer-polyolefin layer-compatible modified layer-polar engineering plastics layer-compatible modified layer-polyolefin layer-functionalized surface layer; the nine-layer structure includes: functionalized surface layer- Compatibility modification layer - polyolefin layer - compatibility modification layer - polar engineering plastic layer - compatibility modification layer - polyolefin layer - compatibility modification layer - functionalized surface layer, the functionalized surface layer at least It includes one of a hydrophilic modified layer, an anti-ultraviolet layer, an antistatic layer and a matte layer. 2. The multilayer polymer film according to claim 1, wherein the five-layer structure is: polypropylene-compatible modified layer-polyethylene terephthalate layer-compatible modified Layer - five-layer co-extruded film of polypropylene, the thickness ratio of each layer is 1:1:1:1:1, and the total thickness is 0.1mm; the compatible modified layer is made of modified polyethylene terephthalate The alcohol ester recycled material is mixed with graft-modified polypropylene particles and formed. 3. a preparation method of a multilayer polymer film, for preparing the multilayer polymer film as claimed in any one of claims 1-2, characterized in that, comprising the steps: (1) mixing polyolefin, initiator and compatibility modifier in a weight ratio of 100:0.1-0.5:1-4, and performing block or graft copolymerization modification to obtain copolymerization-modified polyolefin particles; (2) mixing polar engineering plastics and copolymerized modified polyolefin particles in proportion, and extruding and granulating to obtain a compatible modified material for forming a compatible modified layer; (3) The compatible modified material, polyolefin and polar engineering plastic are respectively added to different extruders in the multi-layer co-extrusion molding equipment, and extruded at the same time to obtain a multi-layer polymer film. 4. the preparation method of multilayer polymer film according to claim 3, is characterized in that, The polyolefin includes at least one of polyethylene, polypropylene, polybutene, and ethylene propylene copolymer; The polar engineering plastics at least include nylon, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, thermoplastic polyester elastomer, thermoplastic polyamide elastomer, polyamide Carbonate or one of its recycled resins; The initiator includes at least dibenzoyl peroxide, di-tert-butyl peroxide, di-tert-butyl peroxide, potassium persulfate, diisopropyl peroxydicarbonate, hydrogen peroxide, azobisisobutyronitrile or one of azobisisoheptanenitrile; The compatibility modifier includes at least one of maleic anhydride, bismaleimide, glycidyl methacrylate, vinyl silane, maleic anhydride-acrylic acid, polyethylene-glycidyl methacrylate . 5. The preparation method of multi-layer polymer film according to claim 3, characterized in that, in step (2), adding a chain extender and blending with polar engineering plastics and copolymerization-modified polyolefin, the extending Chain agents include at least 1,4-butanediol, 1,6-hexanediol, glycerin, trimethylolpropane, diethylene glycol, triethylene glycol, neopentyl glycol, sorbitol, diethylaminoethanol, ethylene glycol A kind of amine, N,N-dihydroxy(diisopropyl)aniline, hydroquinone-di(β-hydroxyethyl)ether, styrene-acrylonitrile-glycidyl methacrylate terpolymer. 6 . The method for preparing a multi-layer polymer film according to claim 3 , wherein the multi-layer co-extrusion molding equipment in step (3) is a co-extrusion blow molding or co-extrusion casting equipment. 7 .