CN115000594A

CN115000594A - Metal-plastic composite film with high stability

Info

Publication number: CN115000594A
Application number: CN202210654906.XA
Authority: CN
Inventors: 庄志; 王卉; 刘倩倩; 程跃
Original assignee: Jiangsu Ruijie New Material Technology Co ltd
Current assignee: Jiangsu Ruijie New Material Technology Co ltd
Priority date: 2022-06-10
Filing date: 2022-06-10
Publication date: 2022-09-02
Anticipated expiration: 2042-06-10
Also published as: CN115000594B

Abstract

The invention provides a metal-plastic composite film with high stability, wherein an anti-corrosion layer is formed on at least one side of a metal layer, the content of each element in the anti-corrosion layer is in gradient distribution, the initial peeling strength and the adhesive property between the metal layer and a second resin layer of the metal-plastic composite film are improved by controlling the content of each element in the anti-corrosion layer, a bridging agent can be added into the anti-corrosion layer, the crosslinking density of the anti-corrosion layer can be improved, and the resistance of the anti-corrosion layer to electrolyte as a content and hydrogen fluoride generated by the reaction of the electrolyte and water is stabilized.

Description

Metal-plastic composite film with high stability

Technical Field

The invention relates to the technical field of metal plastic film production, in particular to a metal plastic composite film with high stability.

Background

At present, lithium ion batteries mainly comprise three types, namely square, cylinder and soft package, wherein the square and cylinder shells mainly adopt hard shells of aluminum alloy, stainless steel and the like, the aluminum alloy shell can be made of aluminum materials, and the soft package shell formed by stacking metal and resin adopts a metal-plastic composite film, so that the problem of inflexible appearance design of hard-package batteries is greatly improved.

The metal-plastic composite film sequentially comprises an outer base material resin layer, an intermediate metal layer, an inner adhesive layer and a thermal welding resin layer from outside to inside, and needs to have temperature and moisture resistance as a battery outer packaging material, so that the problems of layering and the like of a battery shell can be prevented, and the service life of the battery can be ensured.

Generally, metals in the metal-plastic composite film for lithium ion battery external packaging are subjected to corrosion prevention treatment, and when the corrosion prevention treatment effect is not good, the outer base resin layer and the intermediate metal layer are bonded unstably during the use of the battery under severe environments, such as high temperature and high humidity conditions, so that the intermediate metal layer and the outer base resin layer are separated, the outer layer of the battery shell is foamed, the intermediate metal layer is corroded, the service life of the battery is shortened rapidly, and the like, and therefore the metal corrosion prevention treatment has a great influence on the metal-plastic composite film.

At present, the main components of the corrosion prevention treatment solution of the metal-plastic composite film are trivalent chromium compounds, fluorides, aminated phenol resin and phosphoric acid. After the metal is subjected to the anti-corrosion treatment by the anti-corrosion liquid, the corrosion resistance of the metal plastic composite membrane can be improved in some common electrolyte environments, but the water of the battery can possibly permeate through the outer package of the battery to permeate when the battery is used for a long time, so that the intermediate metal layer is separated from the outer base material resin layer, and the outer layer of the battery shell is foamed.

Disclosure of Invention

The invention aims to provide a metal-plastic composite film with high stability, which uses an anti-corrosion layer containing carbon elements and metal elements, and the distribution of various elements in a first anti-corrosion area, a second anti-corrosion area and a third anti-corrosion area presents gradient distribution, thereby realizing high stable bonding performance and further greatly reducing the possibility of interlayer separation of the metal-plastic composite film.

Another object of the present invention is to provide a metal-plastic composite film having high stability, in which a bridging agent is added to an anti-corrosion layer to increase the crosslinking density of the anti-corrosion layer and to stabilize the resistance of the anti-corrosion layer against an electrolyte as a content and hydrogen fluoride generated by the reaction of the electrolyte with water.

To achieve the above object, the present invention provides a metal-plastic composite film with high stability, comprising:

a metal layer; and

an anti-corrosion layer disposed on at least one side of the metal layer, the anti-corrosion layer including a first anti-corrosion region, a second anti-corrosion region, a third anti-corrosion region, a carbon element and a metal element, the first corrosion prevention region is the side of the corrosion prevention layer far away from the metal layer, the second corrosion prevention region is positioned between the first corrosion prevention region and the third corrosion prevention region, and the third corrosion prevention region is the side of the corrosion prevention layer close to the metal layer, and in the first anti-corrosion area, the content ratio of the carbon element is 40-100%, and the content ratio of the metal element is 5-30%, in the second anti-corrosion region, the content ratio of the metal element is 10-70%, and in the third corrosion prevention area, the content ratio of the metal elements is 20-100%.

Preferably, the metal layer further includes a first resin layer and a second resin layer, the first resin layer is disposed on one side of the metal layer, and the second resin layer is disposed on the other side of the metal layer.

Preferably, the first resin layer is bonded to the metal layer by a first adhesive.

Preferably, the material of the first adhesive is at least one of block copolymer polypropylene resin (B-PP), random copolymer polypropylene resin (R-PP) or homopolymer polypropylene resin (H-PP), and the content of polypropylene (PP) in the block copolymer polypropylene resin (B-PP), the random copolymer polypropylene resin (R-PP) and the homopolymer polypropylene resin (H-PP) is not less than 50%.

Preferably, the second resin layer is bonded to the metal layer by a second adhesive.

Preferably, the first resin layer is a heat-sealing resin layer, wherein the material of the first resin layer is at least one of polyolefin, cyclic polyolefin or modified polyolefin.

Preferably, the modified polyolefin is at least one of aliphatic carboxylic acid modified polyolefin, carboxylic acid modified cyclic polyolefin, methacrylic acid modified polyolefin, acrylic acid modified polyolefin, crotonic acid modified polyolefin or imide modified polyolefin.

Preferably, the material of the metal layer is composed of at least one of aluminum alloy, stainless steel, titanium steel or nickel-plated steel plate.

Preferably, the anti-corrosion layer is formed by an anti-corrosion liquid, the anti-corrosion liquid is formed by mixing a trivalent chromium compound, an inorganic acid and an organic resin with water or an organic solvent, the trivalent chromium compound accounts for 1.9-6% of the anti-corrosion liquid, the inorganic acid accounts for 0.3-6% of the anti-corrosion liquid, the organic resin accounts for 0.6-6% of the anti-corrosion liquid, and the water or the organic solvent accounts for 78.6-97.2% of the anti-corrosion liquid.

Preferably, the trivalent chromium compound is composed of at least one of chromium nitrate or chromium fluoride.

Preferably, the inorganic acid is at least one of phosphoric acid, nitric acid or hydrofluoric acid.

Preferably, the organic resin is at least one of an acrylic resin, a methacrylic resin, a hydroxyacrylic resin, a polyvinyl alcohol resin, an olefin resin, and a phenol resin.

Preferably, the organic solvent is at least one of isopropanol, ethanol and ethylene glycol butyl ether.

Preferably, the corrosion-resistant layer contains a bridging agent, wherein the bridging agent is at least one of an amino resin, a melamine resin, a phenol resin, an epoxy compound, a blocked isocyanate compound, an oxazoline compound, a carbodiimide compound, a condensate of formaldehyde and a C1-4 alkyl monohydric alcohol, and a condensation product of carbolic acid or formaldehyde.

Preferably, the content of the bridging agent in the solid content of the corrosion protection solution is 0.05% -15%, or the content of the bridging agent in the solid content of the corrosion protection layer is 0.01% -30%.

Preferably, the corrosion prevention layer includes a titanium (Ti) compound and a zirconium (Zr) compound, a content ratio of the titanium (Ti) compound is not more than 0.6%, and a content ratio of the zirconium (Zr) compound is not more than 2.8%.

Preferably, the titanium (Ti) compound is composed of at least one of titanium fluoride or titanium nitrate, and the zirconium (Zr) compound is composed of at least one of zirconium fluoride and zirconium nitrate.

In order to achieve another object, the present invention provides a method for forming a metal-plastic composite film with high stability, comprising the steps of:

a metal layer; and

the anti-corrosion layer is arranged on at least one side of the metal layer and comprises a first anti-corrosion area, a second anti-corrosion area, a third anti-corrosion area, a carbon element, a metal element and a bridging agent, the first anti-corrosion area is the side of the anti-corrosion layer far away from the metal layer, the second anti-corrosion area is positioned between the first anti-corrosion area and the third anti-corrosion area, the third anti-corrosion area is the side of the anti-corrosion layer close to the metal layer, the content proportion of the carbon element in the first anti-corrosion area is 40-100%, the content proportion of the metal element is 5-30%, the content proportion of the metal element in the second anti-corrosion area is 10-70%, and the third anti-corrosion area, the content ratio of the metal elements is 20-100%.

Preferably, the trivalent chromium compound is at least one of chromium nitrate or chromium fluoride, the inorganic acid is at least one of phosphoric acid, nitric acid or hydrofluoric acid, the organic resin is at least one of acrylic resin, methacrylic resin, hydroxy acrylic resin, polyvinyl alcohol resin, olefin resin or phenolic resin, and the organic solvent is at least one of isopropanol, ethanol and ethylene glycol butyl ether.

Preferably, the crosslinking agent is at least one of an amino resin, a melamine resin, a phenol resin, an epoxy compound, a blocked isocyanate compound, an oxazoline compound, a carbodiimide compound, a condensate of formaldehyde and an alkyl monohydric alcohol having 1 to 4 carbon atoms, a condensate of carbolic acid and formaldehyde, and a derivative thereof.

Preferably, the bridging agent comprises at least one of a silicon compound, a zirconium compound, a metal chelate compound, or an inorganic bridging substance of a metal salt.

Preferably, the silicon compound is silicon dioxide.

Preferably, the zirconium compound is at least one of zirconium ammonium fluoride or zirconium ammonium carbonate.

Preferably, the metal chelate is a titanium chelate.

Preferably, the metal salt is composed of at least one of calcium (Ca), aluminum (Al), magnesium (Mg), iron (Fe), and zinc (Zn).

Preferably, the titanium (Ti) compound is composed of at least one of titanium fluoride or titanium nitrate, and the zirconium (Zr) compound is composed of at least one of zirconium fluoride or zirconium nitrate.

The metal-plastic composite film has the beneficial effects that the anti-corrosion layer with the elements in gradient distribution is formed on the metal layer, so that the initial peeling strength and the bonding property between the metal layer and the second resin layer of the metal-plastic composite film can be improved, the bonding stability of the metal layer and the second resin layer is further ensured, and a bridging agent can be further added to improve the crosslinking density of the anti-corrosion layer, so that the tolerance of the anti-corrosion layer to electrolyte serving as a content and hydrogen fluoride generated by the reaction of the electrolyte and water is stabilized.

Drawings

FIG. 1 is a schematic structural view of a metal plastic composite film according to a first embodiment of the present invention;

FIG. 2 is a schematic view showing a structure of a metal-plastic composite film according to a second embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a metal plastic composite film according to a third embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a metal plastic composite film according to a fourth embodiment of the present invention; and

FIG. 5 is a schematic structural diagram of a metal plastic composite film according to a fifth embodiment of the present invention.

Detailed Description

In order to make the aforementioned and/or other objects, features, and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below:

please refer to fig. 1-5, which are schematic structural diagrams of the metal plastic composite film according to the first to fifth embodiments of the present invention. As shown in the drawings, the structural differences of the metal-plastic composite film 1 are different embodiments of the present invention, and the metal-plastic composite film 1 with high stability of the present invention includes a metal layer 11 and an anti-corrosion layer 12, and further, the metal-plastic composite film 1 further includes a first resin layer 13 and a second resin layer 14, wherein the anti-corrosion layer 12 is disposed on at least one side of the metal layer, the first resin layer 13 is disposed on one side of the metal layer 11, and the second resin layer 14 is disposed on the other side of the metal layer 11, and the details are as follows:

the metal layer 11 functions as a barrier layer for inhibiting moisture penetration, wherein the material of the metal layer 11 is at least one of aluminum alloy, stainless steel, titanium steel and nickel plating, and in one embodiment, the metal layer 11 may be of a metal plate type or a metal foil type, but not limited thereto, and wherein when an aluminum alloy foil is used, a soft aluminum alloy foil made of annealed aluminum alloy or the like is more preferable, from the viewpoint of further improving formability, or an aluminum alloy foil containing an iron component is preferable, and silica, magnesium or the like may be added according to the need of electrolyte resistance or the like, and when a stainless steel foil is used, an austenite system, ferrite system, austenite ferrite system, martensite system, precipitation hardening system stainless steel foil, such as SUS304, SUS301 or 316L, preferably SUS304, may be used.

In one embodiment, when the metal layer 11 is in the form of a metal foil, the thickness of the metal layer 11 is 9 μm to 200 μm, preferably, the thickness of the metal layer 11 is 9 μm to 100 μm, and more preferably, the thickness of the metal layer 11 is 9 μm to 50 μm, but not limited thereto, as long as the metal layer 11 can function to inhibit moisture penetration.

In another embodiment, when the metal layer 11 is a metal plate type, it is preferable that a nickel plating layer is formed on one side of the metal layer 11, so that the metal layer 11 further increases its corrosion prevention effect such as rust prevention, and the surface cleanliness of the metal layer 11 is also improved, and the electrolyte resistance is dramatically improved by the corrosion prevention property of the nickel plating layer and the synergistic effect with the corrosion prevention layer 12, wherein the thickness of the nickel plating layer is not more than 20 μm, and more preferably, the thickness of the metal layer 11 is preferably 1 μm to 5 μm, and when it exceeds 20 μm, although the corrosion prevention property is improved, cracks are easily generated under external pressure load, but not limited thereto.

For this reason, conventionally, when the metal layer 11 has an alloy component, the alloy component is precipitated on the surface of the metal layer 11, or when the annealing step is performed in the rolling step, the volatility of the rolling oil is affected, and therefore, in the adjustment of the alloy component, it is important to manage the surface cleanliness of the metal layer 11 by a method using a wetting agent test wettability as an index or a method using a contact angle as an index, wherein the index as the wettability is class a to class D, preferably class B, and when the index as the contact angle is measured by pure water, the contact angle is not more than 25 °, preferably not more than 20 °, more preferably not more than 15 °, and in one embodiment, the method for measuring the surface wettability of the metal layer 11 may employ "national standard for the republic of china GB/T225638.5-2016, a metal test method, section 5: and the contact angle test method of the metal layer 11 can adopt 'national standard of the people's republic of China GB/T22638.9-2008, part 9 of the metal test method: measurement of hydrophilicity ", but not limited thereto.

When the wettability is lower than D class or the contact angle exceeds 25 DEG, the reactivity or initial adhesion of the corrosion-preventing layer 12 is deteriorated, and if the reactivity is deteriorated, the reaction between the corrosion-preventing layer 12 and the metal layer 11 becomes insufficient, the resistance to permeation of an electrolyte as a battery and the resistance to hydrogen fluoride generated by the reaction between the electrolyte and water are lowered, so that the adhesion of the corrosion-preventing layer 12 to the metal layer 11 is remarkably lowered with the passage of time, the corrosion-preventing layer 12 is dissolved, the metal layer 11 and the corrosion-preventing layer 12 are peeled off, and the battery life is shortened, and the same is true when the initial adhesion of the corrosion-preventing layer 12 and the metal layer 11 is deteriorated, and the present invention adjusts the alloy composition so that the ratio of the alloy is within a certain range, thereby suppressing the precipitation of the alloy from the metal layer 11, in addition, in the annealing step in the rolling step, the temperature and time conditions can be easily controlled.

The anti-corrosion layer 12 comprises a carbon element and a metal element, in one embodiment, the second resin layer 14 is disposed on the side of the metal layer 11 to form the anti-corrosion layer 12, so that the side surface of the metal layer 11 can be stably uniform, variation in adhesion (wettability) can be reduced, the anti-corrosion layer 12 can prevent delamination between the second resin layer 14 and the metal layer 11 when stored in a high-temperature and high-humidity environment for a long time, preferably, the anti-corrosion layer 12 can be further formed on both sides of the metal layer 11, the anti-corrosion layer 12 is formed on the side of the metal layer 11 where the first resin layer 13 is disposed, which mainly prevents hydrogen fluoride generated by reaction of an electrolyte and moisture from corroding the side surface of the metal layer 11, thereby preventing separation between the metal layer 11 and the first resin layer 13, and simultaneously maintains uniformity of the surface of the metal layer 11, so that variation in adhesion (wettability) is small, and the anti-delamination between the first resin layer 13 and the metal layer 11 can be prevented, but not limited thereto.

In addition, the distribution of each element from the side of the corrosion-resistant layer 12 far away from the metal layer 11 to the side close to the metal layer 11 presents gradient distribution, in one embodiment, the corrosion-resistant layer includes a first corrosion-resistant region, a second corrosion-resistant region and a third corrosion-resistant region, the first corrosion-resistant region is the side of the corrosion-resistant layer far away from the metal layer, the second corrosion-resistant region is located between the first corrosion-resistant region and the third corrosion-resistant region, and the third corrosion-resistant region is the side of the corrosion-resistant layer close to the metal layer, therefore, in the first corrosion-resistant region, the content ratio of the carbon element is 40% -100%, and the content ratio of the metal element is not more than 5%; in the second anti-corrosion area, the content ratio of the metal element is 10% -70%, the content ratio of the fluorine element is not more than 30%, and the ratio value of the fluorine element to the metal element is not more than 2; and in the third corrosion prevention area, the content ratio of the metal element is 20-100%, the content ratio of the fluorine element is not more than 20%, and the ratio of the fluorine element to the metal element is not more than 1, but not limited thereto.

In one embodiment, the carbon content of the corrosion protection layer 12 from the side of the second resin layer 14 increases the carbon content of the second resin layer 14 in contact with the corrosion protection layer 12, so that the stability of the composition of the second resin layer 14 and the metal layer 11 can be ensured, if the adhesion of the second resin layer 14 is unstable, and the adhesion and peeling strength are unstable under a high-temperature and high-humidity environment for a long time, the measured metal element in the corrosion protection layer 12 increases with depth, which means that the adhesion of the corrosion protection layer 12 and the metal layer 11 increases, and the capability of resisting the intrusion of external moisture gradually increases, but if the measured metal element in the corrosion protection layer 12 is too high, i.e. the metal element in the first corrosion protection region is more than 30%, or the content of the metal element in the second corrosion protection region is more than 70%, the crosslinking reaction of the metal element with the corrosion protection solution is too much, and the corrosion protection layer 12 formed by the method has high hardness and high brittleness, cracking and pinholes in the corrosion-resistant layer 12 are likely to occur in the subsequent molding process, and external moisture penetrates into the corrosion-resistant layer 12, thereby reducing the adhesiveness of the second resin layer 14.

In an embodiment, the anti-corrosion layer 12 is formed by an anti-corrosion solution, and the anti-corrosion solution is formed by mixing a trivalent chromium compound, an inorganic acid, an organic resin, and water or an organic solvent, wherein the trivalent chromium compound accounts for 1.9-6% of the anti-corrosion solution, the inorganic acid accounts for 0.3-6% of the anti-corrosion solution, the organic resin accounts for 0.6-6% of the anti-corrosion solution, and the water or the organic solvent accounts for 78.6-97.2% of the anti-corrosion solution, and the organic solvent plays a role in reducing the surface tension of the anti-corrosion solution to increase the leveling property of the anti-corrosion solution on the surface of the metal layer 11, but not limited thereto.

In an embodiment, the trivalent chromium compound is at least one of chromium nitrate or chromium fluoride, and the trivalent chromium compound is used to form a coordination crosslinking structure centered on chromium (Cr) atoms on the surface of the metal layer 11, and at this time, the trivalent chromium compound serves to increase the crosslinking degree of the corrosion-resistant film on the surface of the metal layer 11, and is preferably at least one of chromium nitrate and chromium fluoride, wherein the chromium nitrate and chromium fluoride react with the resin, the metal layer 11 and the inorganic acid in the corrosion-resistant layer 12, and the chromium fluoride can improve the temperature resistance and moisture resistance of the corrosion-resistant layer 12, so that the stability of the peeling strength between the second resin layer 14 and the metal layer 11 can be ensured during long-term storage; the inorganic acid is at least one of phosphoric acid, nitric acid or hydrofluoric acid; the organic resin is at least one of acrylic resin, methacrylic resin, hydroxy acrylic resin, polyvinyl alcohol resin, olefin resin or phenolic resin, and the organic resin can improve the bonding stability of the metal layer 11 and the second resin layer 14, wherein the reaction product of the resin component and chromium (Cr), titanium (Ti) or zirconium (Zr) has resistance to external moisture, and can improve the stability of the peeling strength of the second resin layer 14 and the metal layer 11; and the organic solvent is at least one of isopropanol, ethanol and ethylene glycol monobutyl ether, wherein the organic solvent can be used alone as the solvent or added into water, and can improve the wettability of the anti-corrosion liquid and the reaction stability of the anti-corrosion layer 12 and the metal layer 11. At the same time, the surface tension of the corrosion preventing liquid can be reduced, and the uniformity of the coating film can be improved, but the invention is not limited thereto.

In an embodiment, the corrosion protection solution further includes a titanium (Ti) compound or a zirconium (Zr) compound, and the titanium (Ti) compound or the zirconium (Zr) compound is used as a sub-central cross-linking point to enhance corrosion protection of the surface of the metal layer 11, wherein the titanium (Ti) compound accounts for no more than 0.6% of the corrosion protection solution, and the zirconium (Zr) compound accounts for no more than 2.8% of the corrosion protection solution, and the titanium (Ti) compound is at least one of titanium fluoride and titanium nitrate, and the zirconium (Zr) compound is at least one of zirconium fluoride and zirconium nitrate, but not limited thereto.

Further, it is presumed that the effective component in the corrosion preventing liquid reacts with the metal layer 11 to generate a reaction product, for example, a reaction product of a resin component in the corrosion preventing layer 12 and chromium (Cr), titanium (Ti), or zirconium (Zr), a reaction product of an inorganic acid and chromium (Cr), and a reaction product of a fluoride or an inorganic acid in the metal layer 11 and the corrosion preventing layer 12.

In one embodiment, the corrosion protection solution further comprises a bridging agent, wherein the bridging agent is selected from an organic bridging agent and an inorganic bridging agent, the inorganic bridging agent comprises at least one of silica compounds such as silica, zirconium compounds such as zirconium ammonium fluoride and zirconium ammonium carbonate, metal chelates such as titanium chelates, and metal salts such as Ca, Al, Mg, Fe, Zn, and the organic bridging agent comprises at least one of amino resins, melamine resins, phenolic resins, epoxy compounds, blocked isocyanate compounds, oxazoline compounds, carbodiimide compounds, condensates of formaldehyde and C1-4 alkyl monohydric alcohols, and condensates of carbolic acid and formaldehyde, but not limited thereto.

In one embodiment, the bridging agent is at least one of a compound having any one of an isocyanate chemical group, a glycidyl chemical group, a carboxyl chemical group, an oxazoline chemical group, and a silane coupling agent, but not limited thereto.

In one embodiment, the ratio of the bridging agent to the solid component of the corrosion protection solution is 0.01% to 30%, or the ratio of the bridging agent to the solid component of the corrosion protection layer 12 is 0.05% to 15%, but not limited thereto, wherein when the ratio of the bridging agent to the corrosion protection solution is less than 0.1%, the corrosion resistance of the corrosion protection layer 12 cannot be improved by adding the bridging agent, whereas when the ratio of the bridging agent to the corrosion protection solution exceeds 50%, the crosslinking density of the corrosion protection layer 12 becomes large, which causes the corrosion protection layer 12 to be too hard, so that the cracking or peeling of the corrosion protection layer 12 is relatively easy to occur during the forming process, thereby reducing the corrosion resistance, but not limited thereto.

In one embodiment, when the bridging agent is a condensate of formaldehyde and a monohydric alkyl alcohol having 1 to 4 carbon atoms or a condensate of carbolic acid and formaldehyde, the content of the bridging agent in the solid content of the corrosion-resistant layer 12 is 0.01% to 1.0%, and when the content of the bridging agent is less than 0.01, the corrosion resistance of the corrosion-resistant layer 12 cannot be improved by adding the bridging agent, whereas when the content of the bridging agent in the corrosion-resistant solution exceeds 1.0%, the crosslinking density of the corrosion-resistant layer 12 increases, and the corrosion-resistant layer 12 is excessively hard, so that the cracking or peeling of the corrosion-resistant layer 12 is relatively likely to occur during the forming process, thereby reducing the corrosion resistance, but not limited thereto.

In addition, the corrosion-preventing layer 12 may be formed of a plurality of corrosion-preventing liquids currently used, which include at least one of a phosphate, nitric acid, chromate, fluoride and rare earth oxide, wherein, when a phosphate or chromate is used, at least one of, for example, chromium chromate treatment, chromium phosphate treatment, phosphoric acid-chromate treatment or chromate treatment is required, and a chromium compound used for the treatment is, for example, at least one of chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium diphosphate, chromium acetate, chromium chloride or chromium sulfate, and, in the chromate treatment, at least one of etching chromate treatment, electrolytic chromate treatment or coating chromate treatment is mainly used, preferably, coating chromate treatment is preferable.

The coating chromate treatment further includes degreasing treatment in which a treatment solution containing at least one of a metal phosphate such as a chromium phosphate (Cr) salt, a titanium phosphate (Ti) salt, a zirconium phosphate (Zr) salt, and a lead (Zn) phosphite or a nonmetal phosphate salt as a main component is mixed with a synthetic resin, and the treatment solution is applied and dried by a known application method such as a roll coating method, a gravure printing method, and an immersion method, and water, an alcohol solvent, a hydrocarbon solvent, a ketone solvent, an ester solvent, and an ether solvent, preferably water, may be used as the treatment solution.

In one embodiment, the corrosion prevention layer 12 is formed by applying a particulate material in which at least one metal oxide selected from aluminum oxide, titanium oxide, cerium oxide and tin oxide and precipitated barium sulfate are dispersed in phosphoric acid to the surface of the metal layer 11 and sintering the applied particulate material at 150 ℃ or higher, and the surface of the metal layer 11 is degreased by at least one of an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an oxygen activation method and a heat treatment (annealing treatment) during rolling, and the surface of the metal layer 11 is coated with a corrosion prevention liquid by at least one of a bar coating method, a roll coating method, a gravure coating method and a dipping method or subjected to a high-temperature chemical combination reaction, and the amount of the corrosion prevention liquid applied wet film on the metal layer 11 is in the range of 1.6 to 3.2g/m ² And heat-treating at 130-200 deg.C for 0.5-5min after coating the anti-corrosion liquid to form the anti-corrosion layer 12.

In one embodiment, the corrosion prevention layer 12 may be a thin film obtained by a coating type corrosion prevention treatment including at least one component selected from an oxide sol of a rare earth element, an anionic polymer, and a cationic polymer, and the coating type corrosion prevention treatment includes, but is not limited to, a cross-linking agent having phosphoric acid, a phosphate, or a cross-linking agent for cross-linking the polymer.

In one embodiment, the oxide sol is a liquid dispersion medium in which fine particles of a rare earth oxide, for example, particles having an average particle diameter of 100nm or less, are dispersed, the rare earth oxide containing at least one component selected from the group consisting of cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide, and preferably cerium oxide from the viewpoint of further improving the adhesion, and the liquid dispersion medium of the rare earth oxide sol is at least one solvent selected from the group consisting of water, an alcohol solvent, a hydrocarbon solvent, a ketone solvent, an ester compound solvent, and an ether solvent, and preferably water, but not limited thereto.

In one embodiment, the cationic polymer comprises polyethylene pipe imine, a complex ion polymer complex formed by a polymer containing polyethylene pipe imine and carboxylic acid, primary amine Graaff acrylic resin grafted and copolymerized with primary amine on an acrylic main chain, polyacetic acid or a derivative thereof, and at least one of aminated phenol.

In one embodiment, the anionic polymer comprises poly (methyl) acrylic acid or its salt, or a copolymer having (methyl) acrylic acid or its salt as a main component, and the crosslinking agent used is preferably at least one of a compound having any one of an isocyanate chemical group, a glycidyl chemical group, a carboxyl chemical group, an oxazoline chemical group, and a silane coupling agent.

In one embodiment, the corrosion preventing solution is applied to at least one side of the surface of the metal layer 11 to form the corrosion preventing layer 12, but not limited thereto, and more preferably, the corrosion preventing layer 12 is formed on both sides of the surface of the metal layer 11, and the corrosion preventing layer 12 functions to prevent hydrogen fluoride generated by the reaction of the electrolyte and moisture from corroding the surface of the metal layer 11, and at the same time, to maintain the uniformity of the surface of the metal layer 11 so that the change of the adhesiveness, i.e., the wettability, is small, and therefore, the corrosion preventing layer 12 can allow the metal layer 11 to be stored in a high-temperature and high-humidity environment for a long time, and for this reason, the thickness of the corrosion preventing layer 12 is not particularly limited, and in one embodiment, the thickness of the corrosion preventing layer 12 is 1nm to 3.0 μm, and preferably 1nm to 1.5 μm, but not limited thereto.

Furthermore, the metal-plastic composite film 1 of the present invention further includes a first resin layer 13 and a second resin layer 14, the first resin layer 13 is disposed on one side of the metal layer 11, and the second resin layer 14 is disposed on the other side of the metal layer 11, in an embodiment, the first resin layer 13 is bonded to one side of the metal layer 11 by a first adhesive 131, but not limited thereto, or the first adhesive 131 may not be used, and the second resin layer 14 may also be bonded to the other side of the metal layer 11 by a second adhesive 141, or the second adhesive 141 may not be used, wherein the first resin layer 13 is mainly thermally welded, and the material of the first resin layer 13 is at least one of polyolefin, cyclic polyolefin, or acid-modified polyolefin, but not limited thereto.

The polyolefin material may be at least one of polyethylene ethylene- α -olefin copolymers such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene, homopolypropylene, polypropylene block copolymers (for example, block copolymers of propylene and ethylene), polypropylene random copolymers (for example, random copolymers of propylene and ethylene), and the like, propylene- α -olefin copolymers, and ethylene-butene-propylene terpolymers, among which polypropylene is preferable, and when a copolymer is used, the polyolefin may be a block copolymer or a random copolymer, and these polyolefin materials may be used alone or in combination of two or more.

The acid-modified polyolefin may be at least one of an aliphatic carboxylic acid-modified polyolefin, a carboxylic acid-modified cyclic polyolefin, a methacrylic acid-modified polyolefin, an acrylic acid-modified polyolefin, a crotonic acid-modified polyolefin, and an imide-modified polyolefin, wherein the acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of an acid component with a polyolefin, and for this purpose, the acid-modified polyolefin may be formed by copolymerization of a polar molecule such as polyacrylic acid or methacrylic acid with a polyolefin, and the acid component used for acid modification may be a carboxylic acid, sulfonic acid, or acid anhydride such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, and preferably, acrylic acid, maleic acid, or acid anhydride may be used, but not limited thereto.

In one embodiment, the first resin layer 13 further includes a slip agent, which has an effect of improving the moldability of the exterior material for a lithium ion battery, wherein the total class of the slip agent is not particularly limited, and may be selected from known ranges, and the slip agent may be used singly or in combination, preferably, an amide-based slip agent may be selected, but not limited thereto.

When a slipping agent is present on the surface of the first resin layer 13, the content thereof is not particularly limited, and from the viewpoint of improving moldability of the electronic packaging material, a slipping agent content of 10mg/m may be preferred ² -50mg/m ² Preferably 15mg/m ² -40mg/m ² Meanwhile, the slipping agent may be exuded from the resin of the thermal welding resin layer, or may be coated on the surface of the first resin layer 13.

In one embodiment, the first resin layer 13 further includes an antioxidant, which can inhibit thermal degradation in the manufacturing process, wherein the type of the antioxidant is not particularly limited, and may be selected from a known range, and the antioxidant is used singly or in combination.

In one embodiment, the first resin layer 13 functions as a heat-fusible resin layer for sealing the battery module by heat fusion when the battery is assembled, the first resin layer 13 may be made of a single or multiple resins, and the first resin layer 13 may be made of a single-layer or multi-layer resin, and further may be made of the same or different resins.

In one embodiment, the thickness of the first resin layer 13 is required to satisfy the function of sealing the battery module after thermal welding, and therefore, the thickness is not greater than 100 μm, and preferably, 25 μm to 80 μm, and if the thickness of the first resin layer 13 is less than 20 μm, variation in the size and conditions of mechanical processing such as a thermal sealing device may not be sufficiently covered, and it is difficult to obtain a uniform thermal welding portion, resulting in unstable sealing performance, whereas if the thickness of the first resin layer 13 exceeds 100 μm, the amount of water vapor permeation may increase, so that moisture inside the battery increases, and gas may be generated by reaction with the electrolyte, and thus, there is a risk of expansion, rupture, or leakage, and the battery life may be reduced.

In one embodiment, the heat-sealing resin layer may contain an antioxidant component for suppressing thermal deterioration in the production process, and the type of the antioxidant is not particularly limited and may be selected from known ranges, but is not limited thereto.

Meanwhile, the melting point of the first resin layer 13 is in the range of 120 ℃ to 162 ℃, and, preferably, in the range of 130 ℃ to 162 ℃, for example, a single layer or a composite layer composed of at least one mixture of MFR (230 ℃) of 2 to 15g/10min, and more preferably MFR (230 ℃) of 3 to 12g/10min, but not limited thereto, in an embodiment, when the first resin layer 13 is a composite layer, the side not in contact with the metal layer 11 has a thickness of not less than 2 μm, and the melting point is in the range of 130 ℃ to 152 ℃.

When the melting point is below 120 ℃, the resin fluidity can be improved by heating, and, when the resin is pressurized and heat-sealed, the thickness of the resin can be thinned, the adhesive force with the metal layer 11 can be reduced, meanwhile, the resin can flow to the non-extruded edge from the extruded part inside the battery by pressurization, at the moment, the expansion and contraction of the battery and the external force of bending processing can cause cracks, so that the electrolyte can permeate to the metal layer 11 through the cracks, the insulation resistance of the first resin layer 13 is reduced, the electric leakage phenomenon is generated, and the service life of the battery is shortened.

On the other hand, when the melting point exceeds 162 ℃, the crystallinity of the resin is improved, so that the resin fluidity is relatively lowered at the time of pressure heat sealing, and the heat resistance is improved, and a hard and brittle resin layer is formed, so that cracks are caused by external force of expansion and contraction of the battery and bending processing, and stable sealing property is not obtained, and similarly, the same problem is caused when MFR (230 ℃) is less than 2g/10min or when MFR (230 ℃) of the resin is more than 15g/10min, and the same problem is caused when the resin flows to the non-pressed edge portion at the pressed portion in the battery by pressing, and cracks are caused by external force of expansion and contraction of the battery and bending processing, and the electrolyte penetrates into the metal layer 11 through the cracks, so that the insulation resistance of the heat-fusion resin layer is lowered, and the leakage phenomenon occurs, and the battery life is shortened.

The first adhesive 131 mainly serves to bond the metal layer 11 and the first resin layer 13, and therefore, the thickness of the first adhesive 131 is only required to have a function as an adhesive layer, and the thickness ranges from 1 μm to 80 μm, and preferably from 1 μm to 50 μm, in one embodiment, the material of the first adhesive 131 is resin, and the resin may or may not contain a polyolefin main chain, and preferably contains a polyolefin main chain, wherein the polyolefin and its modified resin used for the first adhesive 131 are the same as the resin used for the first resin layer 13, and are polypropylene resin, propylene or ethylene copolymer, but not limited thereto.

In one embodiment, the first adhesive 131 may be a resin composition containing an acid-modified polyolefin and a curing agent, and when the acid-modified polyolefin is used, it is preferably maleic anhydride or acrylic acid-modified polyolefin, and the curing agent used is not particularly limited as long as the acid-modified polyolefin is cured, and preferably, a curing agent of at least one composition of an epoxy-based curing agent, a polyfunctional isocyanate-based curing agent, a carbodiimide-based curing agent, or an oxazoline-based curing agent may be used, but not limited thereto.

When the curing agent is an epoxy-based curing agent, a compound having at least one epoxy group may be used, for example, at least one combination of bisphenol a diglycidyl ether, modified bisphenol a diglycidyl ether, novolac glycidyl ether, glycerol polyglycidyl ether, or polyglycerol polyglycidyl ether; when the curing agent is a polyfunctional isocyanate-based curing agent, only a compound having at least two isocyanate groups is required, and for example, a polymerized or added component of isophorone diisocyanate (PDI), Hexamethylene Diisocyanate (HDI), Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), or a reaction product of such a mixture with another polymer; when the curing agent is a carbodiimide-based curing agent, only a compound having at least one carbodiimide group (-N ═ C ═ N-) is required, for example, a polycarbodiimide compound having at least two carbodiimide groups; and when an oxazoline curing agent is used as the curing agent, only a compound having an oxazoline skeleton is required, but the curing agent may be composed of two or more compounds.

In an embodiment, the material of the first adhesive 131 is a mixture of at least one of a modified polyolefin resin, a block copolymer polypropylene resin (B-PP) containing polypropylene (PP) more than 50%, a random copolymer polypropylene resin (R-PP), or a homo-polypropylene resin (H-PP), and the structure is a single layer or a multi-layer, but not limited thereto.

When the first adhesive 131 compounds the metal layer 11 and the first resin layer 13, a solution type first adhesive 131 may be used, or a hot melt type first adhesive 131 may be used, wherein the solution type first adhesive 131 is formed by using an acid modified polyolefin resin as a main solvent, and at least one of isocyanate, epoxy resin or oxazoline series as a curing agent, or an amine compound such as triethylamine, N-dimethylethanolamine as a curing agent, and dissolving in a solvent of at least one combination of water, ethanol, isopropanol, ethyl acetate, methyl ethyl ketone, toluene and methylcyclohexane, and then uniformly coating the solvent on the surface of the metal layer 11, and heating to volatilize the solvent, so that the thickness of the first adhesive 131 can achieve the desired effect, preferably about 1-10 μm, and more preferably 1-5 μm.

When the thickness of the first adhesive 131 is less than 1 μm, the adhesion between the metal layer 11 and the first resin layer 13 is lowered, causing a problem in adhesion, and when the thickness of the first adhesive 131 exceeds 10 μm, a hard resin layer is formed in the case where a curing agent is reacted, in which case the bending resistance is deteriorated, the flexibility of the metal-plastic composite film 1 is lowered, and there is a risk of crack generation in bending.

The melting point of the acid modified polyolefin resin in the solution type first adhesive 131 is 60-155 ℃, the weight average molecular weight is 10000-150000, the acid value of the solution type first adhesive 131 is 0.5-200mgKOH/g, and the solution type first adhesive 131 mainly comprises the acid modified polyolefin and amine compound as a hardening agent under the condition of no curing agent, wherein the ratio of the acid modified polyolefin to the amine compound is 10-125:1, preferably 15-50:1, the acid used by the modified polyolefin is maleic acid, fumaric acid, methacrylic acid and the like, the amine compound is at least one combination of triethylamine or N, N-2 methyl ethanolamine, the acid modified polyolefin is polypropylene with the melting point of more than 110 ℃, and the content of the polypropylene is more than 50%.

When the melting point of the acid-modified polyolefin is 60 ℃ or lower, the heat resistance is low, and in this case, the metal layer 11 and the first resin layer 13 may be peeled off at a high temperature, and when the melting point of the acid-modified polyolefin exceeds 155 ℃, the heat resistance is relatively good, but when the acid-modified polyolefin reacts with a curing agent, a hard resin layer is formed, and the bending property is not good, so that the flexibility of the metal-plastic composite film 1 is lowered, or cracks are generated by bending, and the metal layer 11 and the first resin layer 13 may be peeled off.

When the weight average molecular weight of the acid-modified polyolefin resin is 10000 or less, the resin has high fluidity when heated, the thickness of the first adhesive 131 becomes seriously thin when heat-sealed, the adhesive strength between the metal layer 11 and the first resin layer 13 becomes low when the curing agent is added, and the sealing performance is problematic, whereas when the weight average molecular weight of the acid-modified polyolefin resin exceeds 150000, the metal layer 11 and the first resin layer 13 form a hard resin layer when the curing agent is added, the bending resistance is deteriorated, the flexibility of the metal-plastic composite film 1 is reduced, or cracks are generated by bending, and the metal layer 11 and the first resin layer 13 are peeled off.

When the acid value of the acid-modified polyolefin resin is less than 0.5mgKOH/g, the curing reaction points with the curing agent are small, and thus the adhesion between the metal layer 11 and the first resin layer 13 is unstable, and when the acid value of the acid-modified polyolefin resin exceeds 200mgKOH/g, the curing reaction between the curing agent and the acid-modified polyolefin resin is too severe, and a hard resin layer is formed, and the bending resistance is deteriorated, so that the flexibility of the metal-plastic composite film 1 is reduced, or cracks are generated due to bending, and the metal layer 11 and the first resin layer 13 may be peeled off.

The first adhesive 131 of hot melt type is an acid-modified polyolefin resin having a melting point of 135-165 ℃ and MFR (230 ℃) of 3-15g/10 min, the thickness of the first adhesive 131 is 2-80 μm, preferably 5-50 μm, the degree of modification of the acid-modified polyolefin resin used for the first adhesive 131 is 1-15%, preferably 3-12%, when the melting point of the acid-modified polyolefin resin is 135 ℃ or lower, the resin fluidity increases by heating, and the thickness becomes thin seriously at the time of heat sealing under pressure, and the adhesion strength between the metal layer 11 and the first resin layer 13 becomes low, which causes a problem of sealability.

On the other hand, when the melting point of the acid-modified polyolefin resin is 165 ℃ or higher, the fluidity at the time of pressure heat sealing is relatively low and the heat resistance is improved, but when the acid-modified polyolefin resin is compounded with the metal layer 11, the heat shrinkage amount is increased to increase the internal stress, the adhesion between the heat-fusion type first adhesive 131 and the metal layer 11 is lowered, and therefore, when the resin is compounded with the metal layer 11 for a long period of time, peeling from the metal layer 11 may occur, and further, when the heat shrinkage is further caused by heating at the time of heat sealing, the adhesion between the metal layer 11 is lowered and the sealing strength is lowered, and when the MFR (230 ℃) of the acid-modified polyolefin resin is less than 3g/10 min, the extrusion film forming property is unstable when the resin is extruded and compounded on the metal layer 11 after the heat fusion, whereas when the MFR (230 ℃) of the acid-modified polyolefin resin is more than 15g/10min, the resin fluidity is increased by heating, and when the acid-modified polyolefin resin is subjected to pressure heat sealing, the thickness becomes too small, and the adhesion strength between the metal layer 11 and the first resin layer 13 becomes low, which causes a problem of sealing property.

When the thickness of the hot-melt type first adhesive 131 is less than 2 μm, the thermal shrinkage amount is too large when the first adhesive is combined with the metal layer 11, and thus the thermal shrinkage cannot be absorbed, and thus the adhesion force with the metal layer 11 is reduced due to an increase in internal stress, and thus, if the first adhesive is left for a long time, the first adhesive may be peeled from the metal layer 11, and if the thickness of the hot-melt type first adhesive 131 exceeds 80 μm, physical problems may not be generated, but the production price may be increased, and if the degree of modification of the hot-melt type first adhesive 131 is less than 1%, the adhesiveness with the metal layer 11 may be unstable, and if the degree of modification of the hot-melt type first adhesive 131 exceeds 15%, physical problems may not be generated, but the production price may be increased.

The second resin layer 14 is a base material of the packaging material for the lithium ion battery, and has at least an insulation property as a limit, and therefore, the thickness of the second resin layer 14 is not particularly limited as long as the second resin layer functions as a base material, and in one embodiment, the resin of the second resin layer 14 is, for example, polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluorine resin, polyurethane, silicone resin, phenolic resin, or a modified product of these resins, and the resin forming the second resin layer 14 may be a copolymer or a modified product of a copolymer of these resins, or a mixture of these resins, and preferably, at least one of polyester and polyamide.

In one embodiment, the polyester used in the second resin layer 14 may be at least one of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, or a copolyester, wherein the copolyester may be a copolyester mainly comprising ethylene terephthalate as a repeating unit, specifically, a copolyester obtained by polymerizing ethylene terephthalate as a repeating unit with ethylene isophthalate, that is, at least one of copolyester (terephthalate/isophthalate)), copolyester (terephthalate/adipate), copolyester (terephthalate/sodium isophthalate), copolyester (terephthalate/phenyl-dicarboxylate), and copolyester (terephthalate/decanedicarboxylate), these polyesters may be used alone or in combination of plural kinds, but are not limited thereto.

In an embodiment, the polyamide used in the second resin layer 14 may be at least one combination of aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and nylon 6 and nylon 66 copolymer, hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (I represents isophthalic acid, and T represents terephthalic acid) containing terephthalic acid and/or isophthalic acid structural units, and aromatic polyamides such as polyamide MXD6 (polyamide PACM6 (poly (4-aminocyclohexyl) methane azide), which may be used alone or in combination of a plurality of types.

In one embodiment, the second resin layer 14 preferably includes at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, preferably at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film, preferably at least one of a biaxially stretched polyethylene terephthalate film, a biaxially stretched polybutylene terephthalate film, a biaxially stretched nylon film, and a biaxially stretched polypropylene film, and the second resin layer 14 may be a single layer or a multilayer, but is not limited thereto.

When the second resin layer 14 is composed of a plurality of layers, the second resin layer 14 may be a composite film formed by the action of the second adhesive 141, a multilayer resin composite film formed by co-extruding resins, and the second resin layer 14 may be formed in an unstretched state or a second resin layer 14 formed by uniaxial stretching or biaxial stretching, and when the second resin layer 14 is a multilayer resin composite film, the thickness of the resin film constituting each layer is preferably in the range of 2 μm to 30 μm, and the total thickness of the second resin layer 14 is preferably in the range of 5 μm to 35 μm, and when the thickness is less than 5 μm, moldability and insulation properties are relatively poor, whereas when it exceeds 35 μm, flexibility is deteriorated.

In an embodiment, the second resin layer 14 may be a single-layer or multi-layer composite film formed by at least one of blown nylon, synchronous or asynchronous biaxially oriented polyethylene terephthalate (PET), synchronous or asynchronous biaxially oriented polybutylene terephthalate (PBT), Polyimide (PI), and the like, and may be adhered to the metal layer 11 by at least one of co-extrusion, coating, compounding, and heat bonding, but not limited thereto.

In one embodiment, when the second resin layer 14 is a multilayer resin composite film, it is preferably at least one combination of a polyester film and nylon film, a multilayer nylon composite film, and a multilayer polyester composite film, preferably a laminate of a stretched nylon film and a stretched polyester film, a multilayer stretched nylon composite film, and a multilayer stretched polyester composite film,

when the outer base resin layer is a multilayer resin composite film, it is preferably a composite film of a polyester resin film and a polyester resin film, a composite film of a polyamide resin film and a polyamide resin film, or a composite film of a polyester resin film and a polyamide resin film, preferably a composite film of a polyethylene terephthalate film and a polyethylene terephthalate film, a composite film of a polybutylene terephthalate film and a polybutylene terephthalate film, a composite film of a nylon film and a nylon film, or a composite film of a polyethylene terephthalate film and a nylon film, and further, since a polyester resin is less likely to change its color when it adheres to the surface due to an electrolytic solution, when the second resin layer 14 is a multilayer resin composite film, it is preferable that the polyester resin film is used as the outermost layer of the second resin layer 14, wherein the multilayer resin films may also be compounded by an adhesive, a glue solution having the same composition as the second adhesive 141 can be used as a preferable adhesive.

In one embodiment, at least one of additives such as a lubricant, a flame retardant, an anti-blocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent may be further added to the surface and the inside of the second resin layer 14, for example, a lubricant, preferably an amide-based lubricant, is applied to the surface of the second resin layer 14, and the application amount of the lubricant is not less than 3mg/m ² Preferably, the coating content is in the range of 4 to 30mg/m ² And, the lubricant present on the surface of the second resin layer 14 may be a lubricant oozed out from the second resin layer 14 containing the lubricant, or a lubricant applied on the surface of the second resin layer 14, wherein the amide-based lubricant includes at least one combination of a saturated fatty acid amide, an unsaturated fatty acid amide, a substituted amide, a methylolamide, a saturated fatty acid bisamide, an unsaturated fatty acid bisamide, a fatty acid amide, and an aromatic bisamide, but is not limited thereto.

In one embodiment, when the lubricant employs saturated fatty acid amide, it includes at least one combination of lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide; when unsaturated fatty acid amides are employed as the lubricant, they include oleamide, erucamide, and the like. The substituted amide comprises at least one combination of N-oil palmitamide, N-stearamide, N-oil stearamide and N-stearamide; when the lubricant employs methylol amides, it includes at least one combination of methylol stearic acid amides; when the lubricant employs a saturated fatty acid bisamide, it includes methylenebisstearamide, ethylenebisoctanoamide, ethylenebislaurate amide, ethylenebisstearamide, ethylenebishydroxystearamide, ethylenebisbehenamide, and hexamethylenebisstearamide, n '-distearyladipamide, n' -distearylsebacate amide, and the like. The unsaturated fatty acid bisamide comprises at least one combination of ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, n '-dioleyl adipic acid amide and n, n' -dioleyl sebacic acid amide; when the lubricant employs a fatty acid ester amide, it comprises at least one combination of stearamide ethyl stearate; and when the lubricant adopts aromatic bisamide, the lubricant comprises at least any one combination of m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide and n, n' -distearyl isophthalic acid amide, but is not limited thereto.

The second resin layer 14 may be formed by a method such as directly forming a resin film from a resin or coating a resin, wherein the resin film is an unstretched film or an elongated film and the elongated film is a uniaxially elongated film or a biaxially elongated film, preferably a biaxially elongated film, and as a method for forming a biaxially elongated film, for example, a stepwise biaxial elongation method, a blown film method or a simultaneous stretching method, and a method for coating a resin, for example, a roll coating method, a gravure coating method or an extrusion coating method, but is not limited thereto.

The second adhesive 141 serves to improve the adhesion between the second resin layer 14 and the metal layer 11, and for this reason, the thickness of the second adhesive 141 is in a range of 1 μm to 10 μm, preferably 2 μm to 5 μm, and the second adhesive 141 is, for example, a two-component curing type adhesive or a one-component curing type adhesive, wherein the second adhesive 141 may be at least one combination of a chemical reaction type, a solvent volatilization type, a hot melt type, a hot press type, and the like, and the second adhesive 141 may be a single layer or a multilayer, but is not limited thereto.

In an embodiment, the second adhesive 141 is a two-component polyurethane adhesive formed by using polyester polyol, polyurethane modified polyol, and the like as a diol main agent, and aromatic or aliphatic isocyanate as a curing agent, wherein the curing agent may be selected according to a functional group of the adhesive component, and for example, the curing agent may be at least one of a multifunctional epoxy resin, a polymer containing methanesulfonic acid, a porlyamine resin, and an inorganic acid, but not limited thereto.

In one embodiment, the second adhesive 141 further includes at least one combination of polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, and copolyester, polyether resins, polyurethane resins, epoxy resins, phenol resins, polyamide resins such as nylon 6, nylon 66, nylon 12, and copolyamides, polyolefin resins such as polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin, polyolefin resins such as polyvinyl acetate, cellulose, (meth) acrylic resins, polyimide resins, polycarbonate, urea resins, and melamine resins, rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber, and silicone resins, but the combination of the second adhesive 141 is not limited thereto, and is preferably a binary or multi-component polyester, polyethylene isophthalate, or copolyester, and the like, The urethane-modified polyester may be a combination of any of polyurethane-modified polyesters and isocyanates, and the isocyanates are not particularly limited to compounds having a plurality of isocyanate groups in the molecule, and examples thereof include at least a mixture of polymers such as isophorone diisocyanate (IPDI), Toluene Diisocyanate (TDI), diphenylmethane-4, 4' -diisocyanate (MDI), and 1, 6-Hexamethylene Diisocyanate (HDI).

The second adhesive 141 may further contain at least one of a coloring agent, a thermoplastic elastomer, a tackifier, and a filler, and the second adhesive 141 contains the coloring agent, so that the packaging material for a lithium ion battery can be colored, and when the coloring agent is used, at least one combination of a pigment and a dye can be used, and when the pigment is an organic pigment, for example, at least one of an azo type, a phthalocyanine type, a quinacridone type, an anthraquinone type, a dioxazine type, an indigo type, a perylene type, and an isoindoline type can be used, and when the pigment is an inorganic pigment, for example, at least one of a carbon black type, a titanium oxide type, a cadmium type, a lead type, and an isoindoline type can be used, and the average particle size of the pigment is in a range of 0.05 μm to 5 μm, preferably in a range of 0.08 μm to 2 μm, and the packaging material for a lithium ion battery is colored, the pigment content thus ranges from 5% to 60%, preferably from 10% to 40%.

In an embodiment, a coloring layer 15 may be further disposed between the second resin layer 14 and the second adhesive 141, for example, the coloring layer 15 is coated on the surface of the second resin layer 14, the surface of the second adhesive 141, or the surface of the metal layer 11 by using ink containing a coloring agent, and the coloring agent used in the coloring layer 15 is the same as that described above, and thus, the description thereof is omitted.

The forming process of the metal-plastic composite film is explained as follows:

before the anti-corrosion liquid is coated, the metal layer 11 needs to be subjected to deoiling treatment on the coating side, the surface wettability of the metal layer 11 is 65dyn/cm, preferably not less than 70dyn/cm, or the titration contact angle of distilled water is not more than 15 degrees, preferably not more than 10 degrees, if the wettability or the surface water contact angle of the metal layer 11 exceeds a given range, the possibility that rolling oil still remains on the metal in the manufacturing stage is shown, so that the interface adhesion capability formed between the anti-corrosion layer 12, the metal layer 11 and the first resin layer 13 is deteriorated, and the battery has the risk of falling off between the metal layer 11 and the first resin layer 13 under long-term storage, and the like, and the battery leakage is easy to occur, and as a preventive measure, the annealing treatment at not less than 150 ℃ can be carried out, and simultaneously, the deoiling can be carried out by plasma, corona method and alkali liquor, wherein, the alkali deoiling method includes immersing the metal layer 11 in 50-65 ℃ alkali liquor, washing the metal layer with deionized water for 2 times after a certain period of time, and drying to obtain the deoiled metal layer 11, but not limited to this.

After the metal layer 11 is deoiled, the surface of the metal layer 11, which is in contact with the metal layer 11, of the second resin layer 14 is coated with an anti-corrosion solution, and then is subjected to a high-temperature heat treatment for a period of time, while the anti-corrosion layer 12 is formed on the side, in another embodiment, the anti-corrosion liquid can be coated on both sides of the metal layer 11, so as to form the anti-corrosion layer 12 on both sides, at this time, further coat the polyurethane adhesive dissolved by the organic solvent, and heat for a period of time to promote the volatilization of the organic solvent, further forming a second adhesive 141, and further compounding the second resin layer 14, the second adhesive 141 and the metal layer 11 at a certain temperature and pressure, and after storing at a certain temperature, causing a curing reaction of the second adhesive 141, thereby obtaining a composite resin layer consisting of the second resin layer 14, the second adhesive 141 and the metal layer 11 in this order.

In one embodiment, the second resin layer 14 and the metal layer 11 can be compounded without using the second adhesive 141 by heating and pressing the metal layer 11 and the second resin layer 14, and the second resin layer 14 is formed into a film by heat treatment, ultraviolet treatment or electron beam treatment to obtain a composite resin layer composed of the second resin layer 14 and the metal layer 11,

the compounding method of the first resin layer 13 may be selected from a different compounding method from the second resin layer 14, and the compounding method using the first adhesive 131 can be roughly classified into the following four methods:

1. the dry lamination method comprises coating the metal layer 11 with a solution-type first adhesive 131, drying, thermally laminating the solution-type first adhesive 131 with the adhesive surface of the first resin layer 13 at a predetermined temperature and pressure, and curing to form a composite of the second resin layer 14/the metal layer 11/the first adhesive 131/the first resin layer 13, preferably, the adhesive surface of the first resin layer 13 in contact with the first adhesive 131 is subjected to corona treatment in advance, and further, the curing treatment may be performed at a temperature of 60 ℃ or less than the melting point of the first adhesive 131.

2. The melt extrusion method is a method in which the first adhesive 131 of a hot melt type is formed on the metal layer 11 to have a predetermined thickness by melt extrusion of a resin, and the surface of the first adhesive 131 is thermally combined with the adhesive surface of the first resin layer 13 to form a composite of the second resin layer 14/the metal layer 11/the first adhesive 131/the first resin layer 13, and further, in order to increase the peeling force between the metal layer 11 and the first resin layer 13, a heat treatment at a temperature of 60 ℃ or less than the melting point of the first adhesive 131 is performed.

3. Melt extrusion method, a composite of the second resin layer 14/the metal layer 11/the first adhesive 131/the first resin layer 13 is formed by co-extrusion of the first adhesive 131 of a hot melt type and the first resin layer 13, and a heat treatment at a temperature of 60 ℃ or less than the melting point of the first adhesive 131 is performed to increase the peeling force between the metal layer 11 and the first resin layer 13.

4. The heat bonding method comprises coating the metal layer 11 with an aqueous solution type first adhesive 131, drying, and heat-bonding the coating with the bonding surface of the first resin layer 13 at a predetermined temperature and pressure to form a composite of the second resin layer 14/the metal layer 11/the first adhesive 131/the first resin layer 13, and further, in order to increase the peeling force between the metal layer 11 and the first resin layer 13, heat treatment at a temperature not higher than 60 ℃ which is the melting point of the first adhesive 131 may be performed, wherein the first resin layer 13 may be formed by extrusion or a film may be used, and when a film is used, it is preferable that the bonding surface of the first resin layer 13 which is in contact with the first adhesive 131 is subjected to corona treatment in advance.

Specifically, the metal-plastic composite film 1 is composed of the second resin layer 14, the second adhesive 141, the metal layer 11, the first adhesive 131, and the first resin layer 13. The thicknesses of the second resin layer 14 and the metal layer 11 may vary according to individual embodiments.

In one embodiment, the stacking method may be used as follows:

the second resin layer 14 contacting the second adhesive 141 was corona-treated, a non-crystalline polyester polyol having a weight average molecular weight of 5000, Tg of 50 ℃, and a hydroxyl value of 25mg KOH/g was mixed with a non-crystalline polyester polyol having a weight average molecular weight of 20000, Tg of-17 ℃, and a hydroxyl value of 8mg KOH/g at a weight ratio of 3:2, Toluene Diisocyanate (TDI) was added to form the second adhesive 141 having an NCO/OH ratio of 6.2, and coated on the metal layer 11, an adhesive layer having a thickness of 3 μm is formed on the metal layer 11, and the second adhesive 141 on the metal layer 11 and the second resin layer 14 are thermally compounded, then, the second resin layer 14/the second adhesive 141/the metal layer 11 were formed by aging treatment at 80 ℃ for 3 days, and both surfaces of the metal layer 11 were subjected to corrosion prevention treatment in advance.

The anticorrosive solutions used in examples 1 to 6 and comparative example 1 were uniformly applied to both sides of the metal layer 11 by coating rolls and baked at 190 ℃ for 2min, and the coating wet film amount of the anticorrosive solution was 5g/m ² 。

Comparative example 2 heating conditions were set to 100 ℃ and heat-baking was carried out for 2 minutes. The amount of the wet coating film of the corrosion-preventing liquid was 5g/m ² 。

And finally, preparing a semi-finished product: the second resin layer 14/the second adhesive 141/the metal layer 11 combines the first adhesive 131 and the first resin layer 13.

Fusion type first adhesive 131 compounding method:

the first adhesive 131 is a melt type resin of anhydrous maleic anhydride modified polypropylene, and is formed with a thickness of 15 μm on the anti-corrosion layer 12 of the metal layer 11 in contact with the first resin layer 13, and further compounded with the first resin layer 13 having a thickness of 30 μm, wherein the first adhesive 131 and the first resin layer 13 are compounded to the anti-corrosion layer 12 of the metal layer 111 in contact with the first resin layer 13 by melt coextrusion, and the first adhesive 131 used is an anhydrous maleic anhydride modified random copolymer polypropylene 60% (by weight) having a melting point of 140 ℃, an MFR (230 ℃) of 5g/10min, a degree of modification of the random copolymer polypropylene by anhydrous maleic anhydride of 10%, a melting point of 160 ℃, an MFR (230 ℃) of 2.6g/10min, and a density of 0.87g/cm3 (by weight), a mixture of 8% by weight of a crystalline copolymer elastomer of ethylene and propylene having a melting point of 130 ℃ and an MFR (230 ℃) of 9.5g/10min and a density of 0.91g/cm3 and 8% by weight of a low-density polyethylene having a melting point of 105 ℃ and an MFR (230 ℃) of 12g/10 min.

In one embodiment, the first resin layer 13 is composed of two resin layers, and has a structure of:

1. resin layer in contact with first adhesive 131:

a mixture layer comprising 62% by weight of a random copolymer polypropylene having a melting point of 155 ℃ and an MFR (230 ℃) of 4g/10min, 33% by weight of an amorphous propylene-based elastomer, and 5% by weight of a low-density polyethylene having a melting point of 110 ℃ and an MFR (230 ℃) of 7.5g/10 min; and

2. resin layer away from the first adhesive 131: a layer consisting of a random copolymer polypropylene having a melting point of 155 ℃ and an MFR (230 ℃) of 15g/10 min.

Wherein the thickness ratio of the resin layer in contact with the first adhesive 131 to the resin layer distant from the first adhesive 131 is 8: 2.

After the metal layer 11 is compounded with the first adhesive 131 and the first resin layer 13, heat treatment is performed at 180 ℃ for 2 seconds to form the metal-plastic composite film 1 with the structure of the second resin layer 14/the second adhesive 141/the metal layer 11/the first adhesive 131/the first resin layer 13 in sequence.

The peel strength between the metal layer 11 and the second resin layer 14 of the metal-plastic composite film 1 was tested as follows:

initial peel strength test:

preparing the metal-plastic composite film 1 into a straight strip shape, wherein the size of a sample strip is 100mm x 15mm, performing a peeling test between the metal layer 11 and the second resin layer 14 by using a tensile test device, placing the peeled second resin layer 14 film in an upper clamping plate of a stretching test device, placing the metal layer 11 in a lower clamping plate, performing T-shaped peeling with a peeling surface of 180 degrees under the condition that the stretching speed is 50 mm/min, and starting to measure the peeling strength between the metal layer 11 and the second resin layer 14, wherein the peeling strength is read in a way that the moving distance between the metal layer 11 and the second resin layer 14 is 50mm, the average value of the peeling strengths between the moving distance of 10mm and 40 mm is selected, and 5 parallel tests are performed per group.

The high temperature and high humidity resistance test of the metal-plastic composite film 1 is as follows:

preparing a finished product of the metal-plastic composite film into a 92(TD) × 76(MD) mm sheet shape, forming the metal-plastic composite film 1 by using a deep punching experimental device, wherein the forming depth is 7mm, the surface pressure of the metal-plastic composite film during forming is 1MPa, the forming time is 5s, and the forming size is 62(TD) × 46(MD), observing the integrity of a sample in a dark room through a light source after the forming is finished, particularly observing whether four corners are damaged, discarding the sample for re-cutting and forming if the sample is broken, and selecting a complete sample.

And then, downwards arranging the groove of the complete deep-drawing sample on a module, wherein the size of the module is 61 x 45mm, the height of the module is 5.5mm, applying downward pressure right above the groove of the sample, and carrying out deformation treatment on the sample, wherein the deformation depth is 1.5mm, meanwhile, the temperature and humidity of a constant temperature and humidity box are adjusted to 65 ℃ 90% RH, after the sample is stabilized, putting the sample which is kept complete after the deep-drawing deformation treatment into the constant temperature and humidity box, observing whether the second resin layer 14 floats at the forming part after 5 days, 10 days and 30 days, and carrying out parallel test by 10 groups.

The measurement method is as follows:

1. water contact Angle measurement

The water contact angle of the metal surface is measured by using a German KRUSS DSA25 contact angle measuring instrument, the metal is flatly placed on an instrument worktable, the water yield of each time of the injector is controlled to be 2 mu mL, the liquid adding speed is 2.67 mu mL/s, and the contact angle value of the metal surface on which the water drops just drop is recorded.

2. Determination of dyne value

Continuously drawing 2 straight lines with the length of 10cm on the metal surface by using a German Architest dyne pen, if the straight line is shrunk by more than 10 percent within 3 seconds, indicating that the dyne value of the metal surface does not reach the dyne value of the dyne pen at the moment, and selecting the dyne pen with the low dyne value for retesting.

3. Elemental determination of the Corrosion protection layer 12

The element distribution of the corrosion-resistant layer 12 was measured by the ESCA method using XPS (AXIS supra, Shimadzu, UK). The Ar ions sputter the metal surface of a sample, the diameter of an ion beam is 800 micrometers, the voltage is 15KV, the sputtering depth of the ion beam is 5nm, the sputtering rate is 3 nm/min, the sputtering times are 7 times, the detection depth of a signal source is 5nm, the detection limit is 1 per thousand, and the detection times are 8 times.

The liquid-resistant sample manufacturing method comprises the following steps: the metal forming the corrosion prevention layer 12 was cut into a strip having a width of 20mm and a length of 100mm, and the strip was immersed in dimethyl carbonate (DMC) containing 1mol/LLiPF 6: diethyl carbonate (DEC): adding 1000PPM water accounting for the total mass of the electrolyte into a solvent with the Ethylene Carbonate (EC) ratio of 1:1:1, soaking for 3 days at the temperature of 85 ℃, taking out, washing for 15 minutes, and wiping off water.

Example 1

The metal layer 11 was made of aluminum foil, the 8021 type annealed metal having a thickness of 40 μm and a water contact angle of 20 ° was used as the metal layer 11, both surfaces of the metal layer 11 were subjected to corrosion prevention treatment, and the respective elements in the corrosion prevention layers 12 on both surfaces of the metal layer 11 were contained in the ratios, and chromium fluoride, hydrofluoric acid, and polyvinyl alcohol resin on the surface of the metal layer 11 were obtained as described in table 1The content ratio is 15:1:3, the chromium (Cr) content coated on the surface of the metal layer 11 is 10mg/m ² 。

Example 2

The metal layer 11 is made of aluminum foil, the used 8021 series annealing treatment metal with the metal layer 11 thickness of 40 μm and the dyne value of 75dyn/cm, both surfaces of the metal layer 11 are subjected to corrosion prevention treatment, the proportion of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 is as shown in Table 1, the content ratio of chromium fluoride, hydrofluoric acid, polyvinyl alcohol resin and titanium fluoride on the surface of the obtained metal layer 11 is 15:1:3:2, and the content of chromium (Cr) coated on the surface of the metal layer 11 is 15mg/m ² 。

Example 3

The metal layer 11 is made of aluminum foil, the used 8021-series annealing treatment metal with the thickness of the metal layer 11 of 40 μm and the water contact angle of 10 degrees is adopted, both surfaces of the metal layer 11 are subjected to corrosion prevention treatment, the proportion of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 is as shown in Table 1, the content ratio of chromium phosphate, phosphoric acid and phenolic resin on the surface of the obtained metal layer 11 is 5:2:1, and the content of chromium (Cr) coated on the surface of the metal layer 11 is 12mg/m ² 。

Example 4

The metal layer 11 is made of aluminum foil, the used 8021-series annealing treatment metal with the thickness of the metal layer 11 of 33 microns and the water contact angle of 15 degrees is used, the metal layer 11 is cleaned by alkaline cleaning agent, both surfaces of the surface of the metal layer 11 are subjected to anti-corrosion treatment, the proportion of each element in the anti-corrosion layers 12 on both surfaces of the surface of the metal layer 11 is as shown in table 1, the content ratio of chromium nitrate, phosphoric acid and acrylic resin on the surface of the obtained metal layer 11 is 2:2:1, and the content of chromium (Cr) coated on the surface of the metal layer 11 is 30mg/m ² 。

Example 5

The metal layer 11 is made of aluminum foil, the adopted 8021-series annealing treatment metal with the thickness of the metal layer 11 being 50 microns and the water contact angle being 15 degrees is used, the metal layer 11 is cleaned by alkaline cleaning agent, both surfaces of the surface of the metal layer 11 are subjected to anti-corrosion treatment, the proportion of each element in the anti-corrosion layers 12 on both surfaces of the surface of the metal layer 11 is as shown in table 1, the content ratio of the chromium nitrate, the phosphoric acid and the acrylic resin on the surface of the obtained metal layer 11 is 2:2:1, and the chromium is coated on the surface of the metal layer 11The (Cr) content is 25mg/m ² 。

Example 6

The metal layer 11 is made of aluminum foil, the used 8021-series annealing treatment metal with the thickness of the metal layer 11 being 40 mu m and the water contact angle being 15 degrees is adopted, both surfaces of the metal layer 11 are subjected to corrosion prevention treatment, the content of the bridging agent in the corrosion prevention liquid is 0.06 percent, the proportion of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 is as shown in Table 1, the content ratio of the chromium nitrate, the phosphoric acid and the acrylic resin on the surface of the obtained metal layer 11 is 2:2:1, and the content of the chromium (Cr) coated on the surface of the metal layer 11 is 15mg/m ² 。

Example 7

The metal layer 11 is made of aluminum foil, the used 8021-series annealing treatment metal with the thickness of the metal layer 11 being 40 mu m and the water contact angle being 15 degrees is adopted, both surfaces of the metal layer 11 are subjected to corrosion prevention treatment, the content of the bridging agent in the corrosion prevention liquid is 8.3 percent, the proportion of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 is as shown in Table 1, the content ratio of the chromium nitrate, the phosphoric acid and the acrylic resin on the surface of the obtained metal layer 11 is 2:2:1, and the content of the chromium (Cr) coated on the surface of the metal layer 11 is 15mg/m ² 。

Example 8

The metal layer 11 is an aluminum foil, the used 8021 annealing treatment metal with the metal layer 11 thickness of 40 μm and the water contact angle of 15 degrees is adopted, both surfaces of the metal layer 11 are subjected to corrosion prevention treatment, the content of the bridging agent in the corrosion prevention liquid is 14.93%, the proportion of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 is as shown in table 1, the content ratio of chromium nitrate, phosphoric acid and acrylic resin on the surface of the obtained metal layer 11 is 2:2:1, and the content of chromium (Cr) coated on the surface of the metal layer 11 is 15mg/m ² 。

Comparative example 1

The method comprises annealing an 8021-based annealed metal having a metal layer 11 thickness of 40 μm and a water contact angle of 15 °, subjecting both surfaces of the metal layer 11 to corrosion prevention treatment, and obtaining a metal layer 11 containing chromium fluoride, hydrofluoric acid, and polyvinyl alcohol resin at a ratio of 2:1:5, and a metal layer 11 surface coating chromium (Cr) content of 5, wherein the ratio of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 is as shown in Table 1mg/m ² 。

In examples 1 to 8, the initial peel strength of the metal-plastic composite film was 6.5N/15mm or more, and no lifting or delamination was observed after 5 days in a high-temperature and high-humidity environment (90% at 60 ℃) after molding.

In comparative example 1, the carbon element content of the first corrosion prevention region was 97%, and the metal element content was 4.0%; the content of the metal element in the second anti-corrosion area is 8 percent and is lower; and the content of metal elements in the third corrosion prevention area is 17 percent, and is lower.

At this time, although the initial strength was 7.1N/15mm, the floating delamination was observed after 5 days in a high temperature and high humidity environment (90% 60 ℃ C.) after molding, and the durability was remarkably inferior to that of comparative example 1 and examples 1 to 8.

Comparative example 2

The 8021-based annealed metal having a metal layer 11 thickness of 40 μm and a dyne value of 75dyn/cm was used, both surfaces of the metal layer 11 were subjected to corrosion prevention treatment, the ratio of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 was as shown in table 1, and the content ratio of chromium nitrate, phosphoric acid, and acrylic resin on the surface of the metal layer 11 was 1:2:1, and the content of chromium (Cr) coated on the surface of the metal layer 11 was 15mg/m 2.

In comparative example 2, the carbon element content of the first corrosion prevention region was 38%, and the metal element content was 43.0%, and the metal element content of the second corrosion prevention region was 77%, which is higher; and the content of metal elements in the third corrosion prevention area is 93 percent, which is higher.

In this case, the initial strength was 4.1N/15mm, and all of them were low as compared with examples 1 to 8.

It is presumed that when the content of the metal element in the corrosion-preventing layer 12 is too high, the degree of the bridging reaction is too high, and the formed corrosion-preventing layer 12 is hard and brittle, and is not favorable for molding, and cracks or pinholes are liable to occur, and moisture enters the damaged portion to cause delamination and lifting during storage in a severe environment.

Comparative example 3

The 8021 type annealing treatment metal with the thickness of the metal layer 11 of 40 μm and the dyne value of 75dyn/cm is used, both surfaces of the metal layer 11 are subjected to corrosion prevention treatment, the content of the bridging agent in the corrosion prevention solution is 25%, the proportion of each element in the corrosion prevention layers 12 on both surfaces of the metal layer 11 is 1:2:1, and the content ratio of chromium nitrate, phosphoric acid and acrylic resin on the surface of the metal layer 11 is 1:2:1, and the content of chromium (Cr) coated on the surface of the metal layer 11 is 15mg/m2, as shown in Table 1.

In comparative example 3, the carbon element content of the first corrosion prevention region was 74%, and the metal element content was 26.0%, and the metal element content of the second corrosion prevention region was 52%; (ii) a The content of metal elements in the third corrosion-prevention area is 78%.

At this time, the initial strength was 12.7N/15 mm. Although the peeling strength was superior to that in examples 1 to 8 in the initial stage, the bridging reaction degree in the corrosion-preventing layer 12 was too high due to the content of the bridging agent in the corrosion-preventing solution, the formed corrosion-preventing layer was hard and brittle, and was not easy to mold, and cracks or pinholes were likely to occur, so that moisture was introduced into the damaged portion during storage in a severe environment, and delamination was floated.

TABLE 1 statistics of various data of metal-plastic composite films

In conclusion, compared with the prior art, the active effects of the present invention are that the elements in the anti-corrosion layer 12 on the surface of the metal layer 11 are distributed in a gradient manner, the initial peel strength between the metal layer 11 and the second resin layer 14 of the metal-plastic composite film 1 is improved by controlling the contents of the carbon element and the metal element in the first anti-corrosion region, the contents of the metal element in the second anti-corrosion region and the third anti-corrosion region in the anti-corrosion layer 12, and the content of the bridging agent added thereto, and as can be seen from table one, the cases of examples 1 to 8 are better than those of comparative examples 1 to 3 in the high temperature and high humidity test.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these modifications and improvements should also be considered as the scope of the present invention.

Claims

1. A metal-plastic composite film having high stability, comprising:

a metal layer; and

an anti-corrosion layer disposed on at least one side of the metal layer, the anti-corrosion layer including a first anti-corrosion region, a second anti-corrosion region, a third anti-corrosion region, a carbon element and a metal element, the first corrosion prevention region is the side of the corrosion prevention layer far away from the metal layer, the second corrosion prevention region is positioned between the first corrosion prevention region and the third corrosion prevention region, and the third corrosion prevention region is the side of the corrosion prevention layer close to the metal layer, and in the first anti-corrosion area, the content ratio of the carbon element is 40-100%, and the content proportion of the metal element is 5 to 30 percent, in the second anti-corrosion area, the content proportion of the metal element is 10 to 70 percent, and in the third corrosion prevention area, the content ratio of the metal elements is 20-100%.

2. The metal-plastic composite film according to claim 1, further comprising a first resin layer and a second resin layer, wherein the first resin layer is disposed on one side of the metal layer, and the second resin layer is disposed on the other side of the metal layer.

3. The metal-plastic composite film according to claim 2, wherein the first resin layer is bonded to the metal layer by a first adhesive.

4. The metal-plastic composite film with high stability according to claim 3, wherein the material of the first adhesive is at least one of a block copolymer polypropylene resin (B-PP), a random copolymer polypropylene resin (R-PP) and a homopolymer polypropylene resin (H-PP), and the content of polypropylene (PP) in the block copolymer polypropylene resin (B-PP), the random copolymer polypropylene resin (R-PP) and the homopolymer polypropylene resin (H-PP) is not less than 50%.

5. The metal-plastic composite film according to claim 2, wherein the second resin layer is bonded to the metal layer by a second adhesive.

6. The metal plastic composite film with high stability according to claim 2, wherein the first resin layer is a thermal welding resin layer, wherein the material of the first resin layer is at least one of polyolefin, cyclic polyolefin or modified polyolefin.

7. The metal-plastic composite film according to claim 6, wherein the modified polyolefin is at least one of aliphatic carboxylic acid modified polyolefin, carboxylic acid modified cyclic polyolefin, methacrylic acid modified polyolefin, acrylic acid modified polyolefin, crotonic acid modified polyolefin, and imide modified polyolefin.

8. The metal-plastic composite film with high stability according to claim 1, wherein the material of the metal layer is at least one of aluminum alloy, stainless steel, titanium steel or nickel-plated steel plate.

9. The metal plastic composite film according to claim 1, wherein the corrosion-resistant layer is formed by an anti-corrosion solution, the anti-corrosion solution is formed by mixing a trivalent chromium compound, an inorganic acid and an organic resin with water or an organic solvent, the trivalent chromium compound accounts for 1.9-6% of the anti-corrosion solution, the inorganic acid accounts for 0.3-6% of the anti-corrosion solution, the organic resin accounts for 0.6-6% of the anti-corrosion solution, and the water or the organic solvent accounts for 78.6-97.2% of the anti-corrosion solution.

10. The metal-plastic composite film with high stability according to claim 9, wherein the trivalent chromium compound is at least one of chromium nitrate or chromium fluoride, the inorganic acid is at least one of phosphoric acid, nitric acid or hydrofluoric acid, the organic resin is at least one of acrylic resin, methacrylic resin, hydroxyacrylic resin, polyvinyl alcohol resin, olefin resin or phenolic resin, and the organic solvent is at least one of isopropyl alcohol, ethanol and ethylene glycol butyl ether.

11. The metal plastic composite film with high stability according to claim 9, wherein the corrosion prevention solution comprises a bridging agent, wherein the bridging agent is at least one of amino resin, melamine resin, phenol resin, epoxy compound, blocked isocyanate compound, oxazoline compound, carbodiimide compound, condensate of formaldehyde and C1-4 alkyl-mono alcohol, condensate of carbolic acid and formaldehyde, and derivatives thereof.

12. The metal-plastic composite film with high stability according to claim 11, wherein the bridging agent is contained in an amount of 0.05% to 15% in the solid content of the corrosion prevention liquid, or the bridging agent is contained in an amount of 0.01% to 30% in the solid content of the corrosion prevention layer.

13. The metal-plastic composite film having high stability according to claim 1, wherein the corrosion prevention layer comprises a titanium (Ti) compound and a zirconium (Zr) compound, the content ratio of the titanium (Ti) compound is not more than 0.6%, and the content ratio of the zirconium (Zr) compound is not more than 2.8%.

14. The metal-plastic composite film having high stability according to claim 13, wherein the titanium (Ti) compound is composed of at least one of titanium fluoride or titanium nitrate, and the zirconium (Zr) compound is composed of at least one of zirconium fluoride or zirconium nitrate.

15. A metal-plastic composite film having high stability, comprising:

a metal layer; and

the anti-corrosion layer is arranged on at least one side of the metal layer and comprises a first anti-corrosion area, a second anti-corrosion area, a third anti-corrosion area, a carbon element, a metal element and a bridging agent, the first anti-corrosion area is the side of the anti-corrosion layer far away from the metal layer, the second anti-corrosion area is positioned between the first anti-corrosion area and the third anti-corrosion area, the third anti-corrosion area is the side of the anti-corrosion layer close to the metal layer, in addition, in the first anti-corrosion area, the content proportion of the carbon element is 40-100%, in addition, the content proportion of the metal element is 5-30%, in the second anti-corrosion area, the content proportion of the metal element is 10-70%, and in the third anti-corrosion area, the content ratio of the metal elements is 20-100%.

16. The metal-plastic composite film according to claim 15, further comprising a first resin layer and a second resin layer, wherein the first resin layer is disposed on one side of the metal layer, and the second resin layer is disposed on the other side of the metal layer.

17. The metal-plastic composite film according to claim 16, wherein the first resin layer is bonded to the metal layer by a first adhesive.

18. The metal-plastic composite film with high stability according to claim 17, wherein the material of the first adhesive is at least one of a block copolymer polypropylene resin (B-PP), a random copolymer polypropylene resin (R-PP), or a homo-polypropylene resin (H-PP), and the content of polypropylene (PP) in the block copolymer polypropylene resin (B-PP), the random copolymer polypropylene resin (R-PP), or the homo-polypropylene resin (H-PP) is not less than 50%.

19. The metal-plastic composite film according to claim 16, wherein the second resin layer is bonded to the metal layer by a second adhesive.

20. The metal-plastic composite film according to claim 16, wherein the first resin layer is a thermal welding resin layer, and wherein the first resin layer is made of at least one of polyolefin, cyclic polyolefin, and modified polyolefin.

21. The metal-plastic composite film according to claim 20, wherein the modified polyolefin is at least one of an aliphatic carboxylic acid modified polyolefin, a carboxylic acid modified cyclic polyolefin, a methacrylic acid modified polyolefin, an acrylic acid modified polyolefin, a crotonic acid modified polyolefin, and an imide modified polyolefin.

22. The metal-plastic composite film with high stability according to claim 15, wherein the material of the metal layer is at least one of aluminum alloy, stainless steel, titanium steel or nickel-plated steel plate.

23. The metal-plastic composite film according to claim 15, wherein the anti-corrosion layer is formed by an anti-corrosion solution, the anti-corrosion solution is formed by mixing a trivalent chromium compound, an inorganic acid and an organic resin with water or an organic solvent, the trivalent chromium compound accounts for 1.9-6% of the anti-corrosion solution, the inorganic acid accounts for 0.3-6% of the anti-corrosion solution, the organic resin accounts for 0.6-6% of the anti-corrosion solution, and the water or the organic solvent accounts for 78.6-97.2% of the anti-corrosion solution.

24. The metal-plastic composite film according to claim 23, wherein the trivalent chromium compound is at least one of chromium nitrate and chromium fluoride, the inorganic acid is at least one of phosphoric acid, nitric acid and hydrofluoric acid, the organic resin is at least one of acrylic resin, methacrylic resin, hydroxyacrylic resin, polyvinyl alcohol resin, olefin resin and phenol resin, and the organic solvent is at least one of isopropyl alcohol, ethanol and butyl glycol ether.

25. The metal-plastic composite film according to claim 23, wherein the bridging agent is contained in an amount of 0.05% to 15% in the solid content of the corrosion preventing solution, or the bridging agent is contained in an amount of 0.01% to 30% in the solid content of the corrosion preventing layer.

26. The metal plastic composite film according to claim 15, wherein the bridging agent is at least one of an amino resin, a melamine resin, a phenol resin, an epoxy compound, a blocked isocyanate compound, an oxazoline compound, a carbodiimide compound, a condensate of formaldehyde and an alkyl-alcohol having 1 to 4 carbon atoms, a condensate of carbolic acid and formaldehyde, and a derivative thereof.

27. The metal-plastic composite film according to claim 15, wherein the bridging agent comprises at least one of silicon compound, zirconium compound, metal chelate or inorganic bridging substance of metal salt.

28. The metal-plastic composite film having high stability according to claim 15, wherein the corrosion prevention layer comprises a titanium (Ti) compound and a zirconium (Zr) compound, the content ratio of the titanium (Ti) compound is not more than 0.6%, and the content ratio of the zirconium (Zr) compound is not more than 2.8%.

29. The metal-plastic composite film according to claim 28, wherein the titanium (Ti) compound is at least one of titanium fluoride or titanium nitrate, and the zirconium (Zr) compound is at least one of zirconium fluoride or zirconium nitrate.