CN106848111A - Stack film and manufacturing method thereof - Google Patents

Abstract

The invention provides a stacked film layer and a manufacturing method thereof. The stacked film layer includes a metal layer, a first resin layer, a second resin layer and an adhesive layer. The metal layer has a first surface and a second surface opposite to each other. The first resin layer is disposed on the first surface of the metal film. The second resin layer is disposed on the second surface of the metal film. The adhesive layer is disposed on the second resin layer and is located between the metal film and the second resin layer. The invention has simplified process steps and can accurately control film thickness and process yield.

Description

Stacked film layers and its manufacturing method

technical field

The invention relates to a stacked film layer and a manufacturing method thereof, in particular to a stacked film layer used as a packaging material and a manufacturing method thereof.

Background technique

Lithium batteries are used as storage batteries for portable devices such as notebook personal computers and mobile phones, and for hybrid vehicles and electric vehicles. With the increasing market demand for lithium batteries that can be repeatedly charged and discharged with the characteristics of light weight, high voltage value and high energy density, the demand for lithium batteries such as light weight, durability, high voltage, high energy density and high safety The requirements are also getting higher and higher.

Generally speaking, the aluminum-plastic film used to pack lithium batteries has a laminated structure, and the simplest laminated structure can include a nylon film 11 and a first adhesive layer 12 in sequence from top to bottom as shown in Figure 1. , a metal aluminum foil layer 13 , a second adhesive layer 14 and a sealing layer 15 . As far as the nylon film 11 as the outer layer is concerned, it can improve puncture resistance and formability, but the production steps of the nylon film 11 are relatively complicated, which includes firstly passing nylon plastic pellets through an extruder to form a film, and then passing through a double-layer film to form a film. The shaft stretching machine forms the biaxially stretched nylon film 11 . In addition, in order to have a good adhesive strength between the nylon film 11 and the metal aluminum foil layer 13, it is necessary to apply an adhesive layer to form the first adhesive layer 12 to bond the nylon film 11 to the metal aluminum foil layer 13. superior. In addition, the chemical resistance of the nylon membrane 11 is poor, and the electrolyte may produce whitening marks on the surface of the nylon membrane 11 , resulting in defective products with appearance defects, thereby reducing the yield of finished products.

Therefore, how to improve the insufficient chemical resistance of the outer layer of the aluminum-plastic film to meet the current industry requirements is a problem that those skilled in the art are eager to solve.

Contents of the invention

The invention provides a stacked film layer and a manufacturing method thereof. The stacked film layer has a novel structure, high puncture resistance, chemical resistance and formability. The manufacturing method of the stacked film layer can simplify the process steps, so that it has high process efficiency, and the use of the aluminum-plastic film on the lithium battery can improve the process yield.

A stacked film layer of the present invention includes a metal layer, a first resin layer, a second resin layer and an adhesive layer. The metal layer has a first surface and a second surface opposite to each other. The first resin layer is configured on the first surface of the metal film. The second resin layer is configured on the second surface of the metal film. The adhesive layer is configured on the second resin layer and located between the metal film and the second resin layer.

In an embodiment of the present invention, the material of the metal layer includes aluminum film.

In an embodiment of the present invention, the thickness of the metal layer is 25 microns to 40 microns.

In an embodiment of the present invention, the material of the first resin layer includes polyvinyl butyral.

In an embodiment of the present invention, the thickness of the first resin layer is 5 microns to 30 microns.

In an embodiment of the present invention, the material of the second resin layer includes polypropylene.

In an embodiment of the present invention, the second resin layer has a thickness of 30 microns to 80 microns.

In one embodiment of the present invention, the material of the adhesive layer includes acid-modified polyolefin or acid-modified polypropylene.

In an embodiment of the present invention, the adhesive layer has a thickness of 3 microns to 15 microns.

A method for manufacturing stacked film layers of the present invention includes the following steps: providing a metal layer and a second resin layer, wherein the metal layer has a first surface and a second surface opposite to each other; then, forming an adhesive layer on the second resin layer And between the metal layers, the second resin layer is pasted on the second surface of the metal layer; finally, the first resin layer is formed on the first surface of the metal layer.

In one embodiment of the present invention, the step of laminating the second resin layer on the second surface of the metal layer includes coating an adhesive layer on the second surface of the metal layer by a coating process, and applying the adhesive layer The second resin layer is bonded to the surface of the metal layer, and the second resin layer is bonded to the metal layer.

In one embodiment of the present invention, the step of laminating the second resin layer on the second surface of the metal layer includes coating an adhesive layer on the second resin layer by a coating process, and applying the adhesive layer to the second surface of the metal layer. The surface of the second resin layer is attached to the second surface of the metal layer, so that the second resin layer is attached to the metal layer.

In one embodiment of the present invention, the step of bonding the second resin layer on the second surface of the metal layer includes forming an adhesive layer on the second surface of the metal layer by a coating process; The surface of the layer is placed on the second resin layer, and the second resin layer is bonded to the metal layer by a heat-pressing process.

Based on the above, since the first resin layer in the stack structure of the present invention is disposed on the first surface of the metal film, in addition to good adhesion between the first resin layer and the metal layer, the stack structure of the present invention has a higher Puncture resistance, chemical resistance and formability. In addition, based on the structure of the above-mentioned stacked structure, the manufacturing method of the stacked film layer of the present invention has simplified process steps, and can precisely control film thickness and process yield.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, specific embodiments are described below in detail.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a stack of known battery packaging materials;

2 is a schematic cross-sectional view of a stacked film layer according to an embodiment of the present invention;

3A to 3C are schematic cross-sectional views of the process flow of the method for fabricating stacked film layers according to an embodiment of the present invention.

Reference signs:

11: Nylon membrane

12: The first adhesive layer

13: metal aluminum foil layer

14: Second adhesive layer

15: sealing layer

110: metal layer

110a: first surface

110b: second surface

120: first resin layer

130: Adhesive layer

140: second resin layer

detailed description

Herein, a range indicated by "one value to another value" is a general representation to avoid enumerating all values in the range in the specification. Therefore, the description of a specific numerical range covers any numerical value in the numerical range and the smaller numerical range bounded by any numerical value in the numerical range, as if the arbitrary numerical value and the smaller numerical value are expressly written in the specification. same range.

FIG. 2 is a schematic cross-sectional view of a stacked film layer according to an embodiment of the present invention. Referring to FIG. 2 , a stacked film layer of the present invention includes a metal layer 110 , a first resin layer 120 , an adhesive layer 130 and a second resin layer 140 . In this embodiment, taking the application of the stacked film layers to the aluminum-plastic film of the battery packaging material as an example, the aforementioned film layers will be described in detail below.

The metal layer 110 has a first surface 110a and a second surface 110b opposite to each other. In this embodiment, the material of the metal layer 110 includes aluminum film, which has the function of preventing water vapor and blocking. In one embodiment, the thickness of the metal layer 110 is, for example, 25 microns to 40 microns. For example, in the following embodiments, the thickness of the metal layer 110 is, for example, 40 microns, but the present invention is not limited thereto.

The first resin layer 120 is used as an outer layer of the stacked film layer and is disposed on the first surface 110 a of the metal layer 110 . In addition, the first resin layer 120 is in direct contact with the first surface 110a of the metal layer 110, and serves as a protective film for the stacked film layers to maintain the high puncture resistance of the aluminum-plastic film and the moldability of the battery, and to give Aluminum plastic film has the characteristics of high chemical resistance. In this embodiment, the material of the first resin layer 120 includes, for example, polyvinyl butyral (PVB). In one embodiment, the thickness of the first resin layer 120 is, for example, 5 microns to 30 microns.

The second resin layer 140 is used as an inner layer of the stacked film layer and is disposed on the second surface 110 b of the metal film 110 . The second resin layer 140 is used as an isolation layer for covering the inner core of the battery and isolating the metal layer 110 from the inner core of the battery. In this embodiment, the material of the second resin layer 140 includes, for example, polypropylene (PP). In one embodiment, the thickness of the second resin layer 140 is, for example, 30 microns to 80 microns, and the present invention is not limited thereto.

The adhesive layer 130 is disposed on the second resin layer 140 and located between the metal film 110 and the second resin layer 140 . In this embodiment, the material of the adhesive layer 130 includes, for example, acid-modified polyolefin (mPO) or acid-modified polypropylene (mPP). In one embodiment, the thickness of the adhesive layer 130 is, for example, 3 microns to 15 microns.

Hereinafter, the fabrication method of stacked film layers will be described in detail. 3A to 3C are schematic cross-sectional views of the process flow of the method for fabricating stacked film layers according to an embodiment of the present invention.

First, please refer to FIG. 3A , a metal layer 110 is provided, wherein the metal layer 110 has a first surface 110 a and a second surface 110 b opposite to each other. In this embodiment, the material of the metal layer 110 includes aluminum film. In one embodiment, the thickness of the metal layer 110 is, for example, 25 micrometers to 40 micrometers, but the invention is not limited thereto.

Next, an adhesive layer 130 is formed between the second resin layer 140 and the metal layer 110 , so that the second resin layer 140 is attached to the second surface 110 b of the metal layer 110 , as shown in FIG. 3B . For example, the material of the adhesive layer 130 is acid-modified polyolefin or acid-modified polypropylene. In one embodiment, the thickness of the adhesive layer 130 is, for example, 3 micrometers to 15 micrometers, and the present invention is not limited thereto. In addition, in one embodiment, the material of the second resin layer 140 is, for example, polypropylene, and the thickness of the second resin layer 140 is, for example, 30 micrometers to 80 micrometers, and the present invention is not limited thereto.

Specifically, in one embodiment, when the material of the adhesive layer 130 is, for example, acid-modified polyolefin, the acid-modified polyolefin is coated on the second surface 110b of the metal layer 110 through a coating process. , to form the adhesive layer 130 , and place the surface of the adhesive layer 130 opposite to the metal layer 110 directly on the second resin layer 140 , so that the second resin layer 140 is attached to the metal layer 110 . In another embodiment, when the material of the adhesive layer 130 is, for example, acid-modified polyolefin, the adhesive layer 130 is coated on the second resin layer 140 through a coating process to form the adhesive layer 130, and The surface of the adhesive layer 130 opposite to the second resin layer 140 is directly placed on the second surface 110 b of the metal layer 110 , so that the second resin layer 140 is adhered to the metal layer 110 . In addition, in yet another embodiment, when the material of the adhesive layer 130 is, for example, acid-modified polypropylene, the acid-modified polypropylene is coated on the second surface 110b of the metal layer 110 through a coating process. , to form the adhesive layer 130, and then directly place the adhesive layer 130 on the surface of the metal layer 110 on the second resin layer 140, heat up and increase the pressure, and use a thermocompression process to bond the second resin layer 140 to the metal layer 110 . The coating process includes roll coating, blade coating, slide coating, slot-die or wire bar coating. cloth.

Finally, a first resin layer 120 is formed on the first surface 110 a of the metal layer 110 , as shown in FIG. 3C . Specifically, the first resin layer 120 is coated on the first surface 110a of the metal layer 110 through a coating process, and is completely cured by thermosetting to form a film on the first surface 110a of the metal layer 110. on a surface 110a. In detail, the coating process includes roller coating, doctor blade coating, inclined plate coating, extrusion coating or wire bar coating. In this embodiment, the material of the first resin layer 120 includes polyvinyl butyral, for example. In one embodiment, the thickness of the first resin layer 120 is, for example, 5 micrometers to 30 micrometers, and the present invention is not limited thereto. So far, the stacked film layer of the present invention has been completed. In addition, the above-mentioned manufacturing method is an example in which the second resin layer 140 is formed first, and then the first resin layer 120 is formed, but the present invention is not limited thereto; in other embodiments, the first resin layer can also be formed first After 120, a second resin layer 140 is formed.

It is worth noting that the material of the first resin layer 120 of the present invention includes polyvinyl butyral, which is a cross-linked resin, which not only has high puncture resistance and moldability, but also has high chemical resistance. . In addition, there is good bonding strength between the first resin layer 120 and the metal layer 110 . Among them, the production procedure of the first resin layer 120 only needs a single coating process step, and can be dried and formed into a film by using a thermosetting method, which can effectively control the thickness of the film layer, and can save additional adhesive requirements (ie: There is no adhesive layer between the first resin layer 120 and the metal layer 110 ), thereby ensuring the accuracy of the coating process and the process yield. Since the main structure of the first resin layer 120 of the present invention is a cross-linked resin, the use of the first resin layer 120 will not be limited to the manufacturing process of the second resin layer 140 (that is: the second resin layer 140 is the adhesive layer 130 is directly pasted on the second surface 110b of the metal layer 110 or the adhesive layer 130 is pasted on the second surface 110b of the metal layer 110 by thermocompression).

Examples 1 to 4 and Comparative Examples 1 to 2 including the stacked film layers of the present invention are described below.

<Example>

Please refer to the previous article about the structure and manufacturing method of stacked film layers. Hereinafter, the features of the present invention will be described more specifically with reference to Examples 1-4. Although Examples 1 to 4 below are described, materials used, film thicknesses, processing details, processing flow, and the like can be appropriately changed without departing from the scope of the present invention. Therefore, the present invention should not be limitedly interpreted by the Examples described below.

Example 1

At room temperature, an acid-modified polyolefin (mPO) was coated onto an aluminum film having a film thickness of about 40 micrometers using a knife coating method. Then, the surface of the aluminum layer with acid-modified polyolefin is placed on the polypropylene (polypropylene, PP) film as the inner layer and bonded, so that the polypropylene film is bonded to the aluminum film by the acid-modified polyolefin combination, wherein the acid-modified polyolefin as the adhesive layer has a film thickness of about 3 microns to 5 microns, and the polypropylene film has a film thickness of about 40 microns. Next, a resin layer with polyvinyl butyral (polyvinyl butyral, PVB) is directly coated on the other surface of the aluminum film using a doctor blade coating method, and dried to form a film by a thermosetting method to form a film with The outer layer is 25 microns thick. The stacked film layer of the present invention is completed by the above steps.

Example 2

The stacked film layer of Example 2 is prepared by the same steps as Example 1. The difference is that the film thickness of the outer layer is changed (as shown in Table 1), wherein the film thickness of the outer layer in Example 2 is 15 microns.

Example 3

At room temperature, an acid-modified polypropylene (mPP) is formed into an aluminum film with a film thickness of about 40 microns using a coating process. Then, the surface of the aluminum layer with acid-modified polypropylene is placed on the polypropylene film as the inner layer, and the temperature is raised to 150 degrees Celsius and the pressure is increased to 5 kgf (kilogram-force, kgf), and the heat-pressed The method makes the polypropylene film adhere to the aluminum film by acid-modified polypropylene, wherein the film thickness of the acid-modified polypropylene as an adhesive layer is about 10 microns to 15 microns, and the polypropylene film has a thickness of about 30 microns to 35 microns. Micron film thickness. Next, the resin layer with PVB was directly coated on the other surface of the aluminum film by a doctor blade coating method, and dried to form a film by a thermosetting method to form an outer layer with a film thickness of 25 microns. The stacked film layer of the present invention is completed by the above steps.

Example 4

The stacked film layer of Example 4 was prepared in the same steps as Example 3. The difference is that the film thickness of the outer layer is changed (as shown in Table 1), wherein the film thickness of the outer layer in Example 4 is 15 microns.

<Comparative example>

The structure of the stacked film layers of Comparative Example 1 to Comparative Example 2 can refer to the stacked structure of FIG. layer of sealing layer 15.

The manufacturing method of the stacked film layers of Comparative Example 1 to Comparative Example 2 is the same or similar to that of the existing aluminum-plastic film; in simple terms, the nylon plastic pellets are formed into a film through an extruder, and then passed through a biaxial stretching machine Form a biaxially stretched nylon film 11; through the first adhesive layer 12, the nylon layer 11 as the outer layer is bonded to the metal aluminum foil layer 13; and through the second adhesive layer 14, the sealing layer 15 as the inner layer is bonded to the The other surface of the metal aluminum foil layer 13 is attached to each other. Accordingly, the metal aluminum foil layer 13 is located between the nylon film 11 and the sealing layer 15 .

In contrast, the stacked film layer of the present invention differs from the stacked film layers of Comparative Example 1 to Comparative Example 2 in that: in the stacked film layer of the present invention, the outer layer of the present invention (for example: the first resin layer 120) is directly bonded to the metal layer 110.

Comparative example 1

The stacked film layer of Comparative Example 1 is Showa 113um (product name), manufactured by Showa Corporation of Japan, wherein the stacked film layer of Comparative Example 1 is prepared by steps similar to those of Example 1. The difference is that there is an additional first adhesive layer between the outer layer and the metal aluminum foil layer of Comparative Example 1. Therefore, for the lamination process between the inner layer and the metal aluminum foil layer of Comparative Example 1, please refer to the preparation steps of Example 1, which will not be repeated here. For the bonding process between the outer layer and the metal aluminum foil layer in Comparative Example 1, please refer to the description below.

At room temperature, apply the modified acrylic resin to the surface of the metal aluminum foil layer with a film thickness of about 40 microns, and then attach the surface of the metal aluminum foil layer with the modified acrylic resin to a nylon film with a film thickness of about 25 microns bonding, so that the first adhesive layer formed by the modified acrylic resin of the nylon film and the metal aluminum foil layer are bonded together. The film thickness of the first adhesive layer is 3 microns to 5 microns. Accordingly, the stacked film layer of Comparative Example 1 has been completed.

Comparative example 2

The stacked film layer of Comparative Example 2 is DNP D-EL40H (product name), produced by Dainippon Printing Co., Ltd., wherein the stacked film layer of Comparative Example 2 is prepared by steps similar to Example 3. The difference is that there is an additional first adhesive layer between the outer layer and the metal aluminum foil layer of Comparative Example 2. Therefore, for the lamination process between the inner layer and the metal aluminum foil layer of Comparative Example 2, please refer to the preparation steps of Example 3, which will not be repeated here. For the bonding process between the outer layer and the metal aluminum foil layer in Comparative Example 2, please refer to the description below.

At room temperature, apply the modified acrylic resin to the surface of the metal aluminum foil layer with a film thickness of about 40 microns, and then attach the surface of the metal aluminum foil layer with the modified acrylic resin to a nylon film with a film thickness of about 25 microns bonding, so that the first adhesive layer formed by the modified acrylic resin of the nylon film and the metal aluminum foil layer are bonded together. The film thickness of the first adhesive layer is 3 microns to 5 microns. Accordingly, the stacked film layer of Comparative Example 2 has been completed.

PVB: polyvinyl butyral

mPO: acid-modified polyolefin

mPP: acid-modified polypropylene (acid-modified polypropylene)

PP: polypropylene (polypropylene)

A: The product name is Showa 113um, produced by Showa Corporation of Japan

B: The product name is DNP D-EL40H, produced by Dainippon Printing Co.

<Measurement of Peel Strength>

First, the stacked film layers of Examples 1-4 and Comparative Examples 1-2 were cut into test samples with a width of 15 mm. Then, use a universal testing machine (manufactured by Shimadzu Scientific Instrument Co., Ltd. (SHIMADZU), the equipment is called AG-1S) to test the outer layer in each test sample (that is: the resin layer with PVB in the present invention/comparative example) Nylon layer) and the metal layer are subjected to a peel strength test at an angle of 180 degrees at a peeling speed of 50mm/min, and these test samples are stretched to a tensile length of 50mm. Wherein, the tensile length is the median value of 6 test samples. It is worth mentioning that, in the standard set by the industry, for the test of the outer layer and the metal layer, the peel strength of the outer layer must be at least greater than 4N/15mm. Therefore, if the peel strength of the outer layer is greater than 4N/15mm, "○" is recorded in Table 2; if the peel strength of the outer layer is less than or equal to 4N/15mm, "×" is recorded in Table 2.

<Measurement of puncture resistance>

Firstly, the stacked film layers of Examples 1-4 and Comparative Examples 1-2 were respectively made into test samples with a length and width of 10 cm×10 cm. Then, using an intelligent electronic tensile testing machine (manufactured by Labthin Corporation), the outer layer in each test sample is subjected to a puncture test of 0.5 degrees with a needle with a diameter of 2.03 mm at a puncture speed of 50 mm/min. , and find the puncture strength (N) at this time, please refer to Table 2. It is worth mentioning that the greater the puncture strength of the outer layer, the less likely the outer layer will be damaged by external forces. That is to say, the outer layer has strong puncture resistance.

<Measurement of drawing depth>

First, the stacked film layers of Examples 1-4 and Comparative Examples 1-2 were made into test samples with a length and width of 8 cm×10 cm, respectively. Next, each test sample was subjected to a cold stamping test with a pressure of 6 kg, and these test samples were drawn to a depth greater than 4 mm. After the cold punching shell test, observe whether the test sample is broken or delaminated. If there is no perforation or delamination, "○" is recorded in Table 2. If there is a break or delamination, the "×" is recorded.

<Measurement of heat resistance>

First, the stacked film layers of Examples 1-4 and Comparative Examples 1-2 were made into test samples with a length and width of 3 cm×15 cm, respectively. Next, a hot-press test was performed on each test sample at a temperature of 220 degrees Celsius and a pressure of 0.3 MPa for 3 seconds. After the hot pressing test, observe whether the outer layer of the test sample is damaged, if the outer layer is not damaged, then record "○" in Table 2, and if the outer layer is damaged, then record "×" in Table 2.

<Measurement of solvent resistance>

Firstly, the stacked film layers of Examples 1-4 and Comparative Examples 1-2 were respectively made into test samples with a length and width of 10 cm×10 cm. Next, the outer layer of each test sample was wiped with alcohol and methyl ethyl ketone (MEK) respectively, and left for 1 minute. After 1 minute, observe whether the outer layer of the test sample is damaged (for example: the surface of the outer layer is eroded), if the outer layer is not damaged, then record "○" in Table 2, if the outer layer is damaged, then Table 2 "×" is recorded in .

<Measurement of anti-electrolyte>

Firstly, the stacked film layers of Examples 1-4 and Comparative Examples 1-2 were respectively made into test samples with a length and width of 10 cm×10 cm. Next, the outer layer in each test sample was wiped with an electrolytic solution (DEC/EMC/EC=1/1/1 (wt%)+LiPF ₆ ), and left for 1 minute. After 1 minute, observe whether the outer layer of the test sample is damaged (for example: the surface of the outer layer is eroded), if the outer layer is not damaged, then record "○" in Table 2, if the outer layer is damaged, then Table 2 "×" is recorded in .

Table 2

It can be seen from Table 2 that compared with Comparative Examples 1-2, the stacked film layers of Examples 1-4 also maintain good performance in peel strength test, drawing depth test, heat resistance test and solution resistance test, which means The stacked film layers of Examples 1-4 have good adhesive strength and formability. In addition, it can also be seen from Table 2 that compared with Comparative Example 1-2, the stacked film layer of Example 1-4 does have better performance in the puncture resistance test and the anti-electrolyte test, which means that Example 1- The stacked film layer of 4 has good puncture resistance and chemical resistance.

In summary, since the first resin layer in the stack structure of the present invention is disposed on the first surface of the metal film, there is good adhesion between the first resin layer and the metal layer; and the first resin layer can be used as The outer protective film of the metal layer makes the stack structure of the present invention have high puncture resistance, chemical resistance and formability. In addition, since the stacking structure of the present invention is different from the existing stacking structure, compared with the existing stacking structure manufacturing method, the manufacturing method of the stacking film layer of the present invention has relatively simplified process steps, which only A single coating process is required, and the outer layer can be dried and formed into a film by using the thermosetting method, which can effectively control the thickness of the film layer and save the need for additional adhesive materials (namely: between the first resin layer and the metal layer) There is no adhesive layer between them), thereby ensuring the accuracy of the coating process and the process yield.

Although the present invention has been disclosed above in terms of implementation, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of the invention should be determined by the appended claims.

Claims (13)

1. a kind of storehouse film layer, it is characterised in that including：

Metal level, with each other relative first surface and second surface；

First resin bed, is configured on the first surface of the metal film；

Second resin bed, is configured on the second surface of the metal film；And

Adhesion layer, is configured on second resin bed, and positioned at the metal film and described second Between resin bed.

2. storehouse film layer according to claim 1, it is characterised in that the material bag of the metal level Include aluminium film.

3. storehouse film layer according to claim 1, it is characterised in that the thickness of the metal level is 25 microns to 40 microns.

4. storehouse film layer according to claim 1, it is characterised in that the material of first resin bed Material includes polyvinyl butyral resin.

5. storehouse film layer according to claim 1, it is characterised in that the thickness of first resin bed Spend is 5 microns to 30 microns.

6. storehouse film layer according to claim 1, it is characterised in that the material of second resin bed Material includes polypropylene.

7. storehouse film layer according to claim 1, it is characterised in that the thickness of second resin bed Spend is 30 microns to 80 microns.

8. storehouse film layer according to claim 1, it is characterised in that the material bag of the adhesion layer Include acid modified polyolefin or sour modified polypropene.

9. storehouse film layer according to claim 1, it is characterised in that the thickness of the adhesion layer is 3 Micron is to 15 microns.

10. a kind of preparation method of storehouse film layer, it is characterised in that including：

Metal level and the second resin bed are provided, wherein the metal level has each other relative first surface With second surface；

Adhesion layer is formed between second resin bed and the metal level, makes second resin bed Fit on the second surface of the metal level；And

In forming the first resin bed on the first surface of the metal level.

11. preparation methods according to claim 10, it is characterised in that make second resin bed The step on the second surface of the metal level is fitted in, including：

With coating process, the adhesion layer is applied on the second surface of the metal level；And

The adhesion layer is fitted on second resin bed relative to the surface of the metal level, makes institute The second resin bed is stated to be fitted with the metal level.

12. preparation methods according to claim 10, it is characterised in that make second resin bed The step on the second surface of the metal level is fitted in, including：

With coating process, the adhesion layer is applied on second resin bed；And

The adhesion layer is fitted in described the of the metal level relative to the surface of second resin bed On two surfaces, second resin bed is set to be fitted with the metal level.

13. preparation methods according to claim 10, it is characterised in that make second resin bed The step on the second surface of the metal level is fitted in, including：

With film processing procedure, the adhesion layer is formed on the second surface of the metal level；

The adhesion layer is positioned on second resin bed relative to the surface of the metal level；And

With hot pressing manufacture procedure, second resin bed is set to fit in the metal level.