CN112389033A

CN112389033A - Color aluminum plastic film for battery packaging and preparation method thereof

Info

Publication number: CN112389033A
Application number: CN202011078024.0A
Authority: CN
Inventors: 赵金保; 代威明
Original assignee: Xiamen University
Current assignee: Xiamen University
Priority date: 2020-10-10
Filing date: 2020-10-10
Publication date: 2021-02-23

Abstract

The invention discloses a colored aluminum-plastic film for packaging a battery and a preparation method thereof, wherein the colored aluminum-plastic film sequentially comprises a substrate layer, a first adhesive layer, a metal-plated film layer, an aluminum foil layer, a second adhesive layer and a heat-sealing layer from outside to inside; the aluminum foil layer comprises an intermediate layer and an anodic oxidation layer, and the anodic oxidation layer is arranged on one side or two sides of the intermediate layer; the metal-plated film layer is attached to the surface of the anodic oxide layer by an ion sputtering method, and the same metal film layer can show different colors such as red, orange, yellow, green, blue, purple, gray and the like by changing parameters such as electrolyte, oxidation voltage, current, time and the like of anodic oxidation; the substrate layer is made of transparent insulating materials. According to the invention, the aluminum foil is subjected to anodic oxidation and ion sputtering technology, so that the aluminum plastic film is colored, good bonding force of the substrate layer and the aluminum foil layer is ensured, and good character prominence and color variability are provided.

Description

Color aluminum plastic film for battery packaging and preparation method thereof

Technical Field

The invention belongs to the technical field of aluminum-plastic films for batteries, and particularly relates to a colored aluminum-plastic film for battery packaging and a preparation method thereof.

Background

In recent years, along with the increase in performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, cellular phones, and the like, batteries are required to have not only high energy density but also various shapes, as well as thin and light weight. However, the metal-made battery packaging materials that have been used in many cases have the following disadvantages: it is difficult to follow the diversification of the shape, and there is a limit to the reduction in weight.

Then, the aluminum plastic film is used as an outer packaging material of the battery to package the battery. The battery packaged with the aluminum plastic film has advantages of high energy density, easy processing into various shapes, and realization of thinning and light weight compared with the conventional metal-case battery.

Although the aluminum plastic film endows the battery with a plurality of excellent performances, the existing aluminum plastic film still has the following defects: the existing aluminum-plastic film is mainly composed of a transparent cast polypropylene film, transparent polyamide fibers, a transparent adhesive and an aluminum foil, so that the aluminum-plastic film shows the color of the aluminum foil in appearance, when the color of characters which are printed on the surface of the aluminum-plastic film and represent product information is white or other light color systems, the appearance prominence is poor, and the appearance design of the aluminum-plastic film is not rich enough.

The common aluminum plastic film for the battery is not printed, the appearance looks monotonous in metallic color, and most of the common aluminum plastic film for the battery have the problems of high coloring difficulty, difficulty in color blending and high color keeping difficulty, and are easy to deform, difficult to process and the like. Some adopt the adhesive to add into the ink, mainly black, the color is monotonous, and carbon black addition is too much, difficult to disperse, easy to subside, the ink has reduced the compound interlaminar strength, the adhesive force of adhesive to polyamide can decline, cause the plastic-aluminum membrane formability to reduce, the delaminating phenomenon happens very easily, influence use and final apparent of plastic-aluminum membrane. Statistics shows that in the actual production process, the process of coating the black matte oil can cause about 30-40% of aluminum-plastic film loss, and the cost is greatly increased.

Therefore, the single metal color of the existing aluminum plastic film packaging material for the battery limits the design of the outer packaging patterns of the battery, and the use of the ink easily causes the reduction of the yield and the performance of the aluminum plastic film.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a colored aluminum-plastic film for battery packaging and a preparation method thereof.

One of the technical schemes adopted by the invention for solving the technical problems is as follows: the color aluminum plastic film for packaging the battery comprises a substrate layer, a first adhesive layer, a metal-plated film layer, an aluminum foil layer, a second adhesive layer and a heat sealing layer from outside to inside in sequence;

the aluminum foil layer comprises an intermediate layer and an anodic oxidation layer, and the anodic oxidation layer is arranged on one side or two sides of the intermediate layer; the metal-plated film layer is attached to the surface of the anodic oxidation layer by an ion sputtering method and is used for presenting a color different from that of the aluminum foil or the plated metal; the substrate layer is made of transparent insulating materials.

In a preferred embodiment of the present invention, the thickness of the metal-plated film layer is 1 to 100nm, the plating metal includes gold, platinum and chromium, and the particle size of the plating metal is 1 to 100 nm.

In a preferred embodiment of the present invention, the thickness of the anodized layer is 10 to 2000nm, and holes with a diameter of 30 to 140nm are uniformly distributed on the anodized layer.

The second technical scheme adopted by the invention for solving the technical problems is as follows: the preparation method of the color aluminum plastic film comprises the following steps:

(1) preparing an aluminum foil layer: anodizing the aluminum foil on one side or two sides to obtain an aluminum foil layer consisting of an intermediate layer and an anodic oxidation layer; the anodic oxidation voltage is 3-120V or the current density is 50-800 mA/dm²The oxidation time is 5-60 min, the electrolyte adopts at least one of 0.1-0.5 mol/L phosphoric acid, sulfuric acid and oxalic acid, and the temperature of an electrolyte tank is 20-30 ℃;

(2) spraying a metal coating layer: spraying metal on the surface of the anodic oxide layer aluminum foil layer by using an ion sputtering instrument for 15-60 s to obtain a colored laminated body;

(3) a composite base material layer: connecting a base material layer on the surface of the colored laminate obtained in the step (2) by using a first adhesive layer to obtain a laminate combined with the base material;

(4) preparing a heat sealing layer: and (3) compounding hot-melt resin to the surface, far away from the base material layer, of the laminated body in the step (3) by using a second adhesive to form a heat sealing layer, and aging and heating the heat sealing layer at the temperature of 60-120 ℃ for 3-4 days to obtain the colored aluminum plastic film.

In a preferred embodiment of the present invention, the aluminum foil in step (1) is annealed, and is pretreated by alkali washing to remove oil, water washing, acid washing neutralization and water washing before anodic oxidation.

In a preferred embodiment of the present invention, the step (3) and the step (4) adopt a dry lamination method or an extrusion molding method to realize interlayer connection.

Compared with the background technology, the technical scheme has the following advantages:

1. the aluminum-plastic film is enabled to display different colors such as red, orange, yellow, purple, blue and the like by combining constant-voltage or constant-current anodic oxidation with an ion sputtering technology, the colors are regularly controlled by adjusting parameters of anodic oxidation (particularly, the aluminum foil layer generates different colors when the same metal is used for spray coating by changing the types and concentration of the anodic oxidation electrolyte and the process parameters such as oxidation voltage, time and the like), the aluminum foil layer is endowed with multiple colors, and better character saliency and color variability are provided;

2. the scheme replaces printing ink to enable the aluminum-plastic film to be colored, ensures good bonding force of the substrate layer and the aluminum foil layer, effectively avoids the phenomenon that the forming performance of the aluminum-plastic film is reduced and delaminated due to the printing ink, and obtains the colored aluminum-plastic film meeting the packaging requirements of the battery.

Drawings

FIG. 1 is a layer structure diagram of a color aluminum plastic film of example 1.

FIG. 2 is a layer structure diagram of the color aluminum plastic film of example 2.

FIG. 3 is a schematic diagram of an apparatus for double-sided anodization.

FIG. 4 is a schematic view of a single-sided anodization apparatus.

The composite material comprises, by weight, 1-a substrate layer, 2-a first adhesive layer, 3-a metal-plated film layer, 4-an anodic oxidation layer (outer layer), 5-a middle layer, 6-a second adhesive layer, 7-a heat sealing layer, 8-a colored aluminum plastic film, 9-an anodic oxidation layer (inner layer), 10-an ammeter, 11-an anodic oxidation power supply, 12-a voltmeter, 13-a graphite plate, 14-an anodic oxidation tank, 15-an anodic oxidation electrolyte and 16-a graphite plate (double-sided anodic oxidation).

Detailed Description

The invention relates to a colored aluminum-plastic film for packaging a battery, which sequentially comprises a substrate layer, a first adhesive layer, a metal-plated film layer, an aluminum foil layer, a second adhesive layer and a heat sealing layer from outside to inside;

1. Substrate layer

The thickness of the base material layer is not more than 30 μm, and the base material layer 1 is a layer located on the outermost layer side. The material for forming the base layer 1 is not particularly limited as long as it has insulation properties. Examples of the material for forming the base layer 1 include polyamide, polyester, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenolic resin, polyetherimide, polyimide, polycarbonate, and a mixture or copolymer thereof.

Specific examples of the polyamide include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; aromatic-containing polyamides such as hexamethylenediamine-isophthalic acid-terephthalic acid copolyamides including constituent units derived from terephthalic acid and/or isophthalic acid, nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (I represents isophthalic acid and T represents terephthalic acid), and polyamides such as polymetaxylylene adipamide (MXD 6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM 6); polyamide obtained by copolymerizing a lactam component and/or an isocyanate component such as 4, 4' -diphenylmethane-diisocyanate, a polyester amide copolymer or a polyether ester amide copolymer which is a copolymer of a copolymerized polyamide with a polyester or a polyalkylene ether glycol; copolymers thereof, and the like. These polyamides may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The stretched polyamide film has excellent stretchability, can prevent whitening due to cracking of the resin of the base layer 1 during molding, and is suitable for use as a material for forming the base layer 1.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, a copolyester mainly composed of ethylene terephthalate and a copolyester mainly composed of isobutylene terephthalate. Specific examples of the copolyester mainly composed of ethylene terephthalate as a repeating unit include a copolyester mainly composed of ethylene terephthalate and polymerized with ethylene isophthalate (hereinafter, polyethylene (terephthalate/isophthalate)), polyethylene (terephthalate/isophthalate), polyethylene (terephthalate/adipate), polyethylene (terephthalate/sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate), and polyethylene (terephthalate/decanedicarboxylate). Specific examples of the copolyester mainly composed of a butylene terephthalate as a repeating unit include a copolyester mainly composed of a butylene terephthalate as a repeating unit and polymerized with a butylene isophthalate (hereinafter, the copolyester is not referred to as polybutylene (terephthalate/isophthalate)), polybutylene (terephthalate/adipate), polybutylene (terephthalate/sebacate), and polybutylene naphthalate. These polyesters may be used alone in 1 kind, or may be used in combination in 2 or more kinds. The polyester has advantages such as excellent electrolyte resistance and difficulty in whitening due to adhesion to the electrolyte, and is suitable for use as a material for forming the substrate layer 1.

The base layer 1 may be formed of a 1-axis or 2-axis stretched resin film, or may be formed of an unstretched resin film. Among them, a 1-or 2-axis stretched resin film, particularly a 2-axis stretched resin film, is preferably used as the base material layer 1 because heat resistance is improved by oriented crystallization. Among these, as the resin film forming 1, from the viewpoint of exhibiting high moldability, nylon and polyester are preferably used, 2-axis stretch nylon and 2-axis stretch polyester are more preferably used, and 2-axis stretch nylon is particularly preferably used.

The thickness of the polyamide film layer is not particularly limited, but is preferably 30 μm or less, more preferably about 1 to 25 μm, and still more preferably about 10 to 25 μm, from the viewpoint of making the aluminum plastic film thinner and exhibiting excellent moldability.

The thickness of the polyester film layer is not particularly limited, but is preferably about 20 μm or less, more preferably about 1 to 15 μm, and still more preferably about 3 to 12 μm, from the viewpoint of making the aluminum plastic film thinner and exhibiting excellent moldability.

2. First adhesive layer

The first adhesive layer 2 is provided between the base layer 1 and the plated film layer 3 as necessary to firmly bond them.

The first adhesive layer is formed of an adhesive capable of bonding the base layer and the plated metal film layer. The adhesive used to form the first adhesive layer may be a two-component curing adhesive or a one-component curing adhesive. The bonding mechanism of the adhesive for forming the first adhesive layer is not particularly limited, and any type of adhesive such as a chemical reaction type, a solvent volatilization type, a hot melt type, and a hot press type may be used.

Specific examples of the adhesive components that can be used to form the first adhesive layer include: polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester; a polyether adhesive; a polyurethane adhesive; an epoxy resin; a phenolic resin; polyamide resins such as nylon 6, nylon 66, nylon 12, and copolyamide; polyolefin resins such as polyolefin, carboxylic acid-modified polyolefin, and metal-modified polyolefin, and polyvinyl acetate resins; a cellulose-based binder; (meth) acrylic resins; a polyimide-based resin; a polycarbonate; amino resins such as urea resins and melamine resins; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; silicone resins, and the like. These adhesive components can be used alone in 1, or can be used in combination of 2 or more. Among these adhesive components, a polyurethane adhesive is preferably used.

The polyurethane adhesive includes, for example, a polyurethane adhesive containing a main component containing a polyol component (a) containing a polyester polyol (a1) and a curing agent containing a polyisocyanate component (B), wherein the polyester polyol (a1) is a polyester polyol composed of a polybasic acid component and a polyol component and having a number average molecular weight of5000-50000 polyester polyol containing 45-95 mol% of aromatic polybasic acid component in 100 mol% of polybasic acid component, and the tensile stress at 100% stretching of adhesive layer is 100kg/cm²Above 500kg/cm²The following. For example, there can be mentioned a polyurethane adhesive comprising a main agent and a polyisocyanate curing agent, wherein the main agent comprises a polyol component (A) and a silane coupling agent (B), the polyol component (A) comprises 5 to 50% by mass of a polyester polyol (A1) having a glass transition temperature of 40 ℃ or higher and 95 to 50% by mass of a polyester polyol (A2) having a glass transition temperature of less than 40 ℃, and the equivalent ratio of isocyanate groups contained in the curing agent to the total of hydroxyl groups and carboxyl groups derived from the polyol component (A) [ NCO ] is the equivalent ratio of the isocyanate groups [ NCO ] in the curing agent]/([OH]+[COOH]) Is 1 to 30.

The thickness of the first adhesive layer is not particularly limited as long as it can function as an adhesive layer, but from the viewpoint of making the aluminum plastic film thinner and lighter, the thickness of the first adhesive layer is preferably about 1 to 10 μm, more preferably about 1 to 5 μm, and still more preferably about 1 to 3 μm.

3. Metal-plated film layer

The metal-plated film layer is sprayed on the anodic oxide layer through an ion sputtering technology, so that the appearance of various colors can be formed, better character prominence and color variability are provided, and the effect of the colored aluminum-plastic film is realized. It should be noted that by changing the electrolyte type and concentration, the oxidation voltage, the time and other process parameters of the anodic oxidation process of the aluminum foil layer, the aluminum foil layer can generate different colors when the same metal is used for spraying. For example, aluminum foil treated with gold sprayed under different anodization conditions will produce different colors such as red, orange, yellow, violet, blue, etc.

The plating metal selected by the plating metal film layer is one or more of gold, platinum, silver, titanium, chromium and the like, and the metals of gold, platinum and chromium are preferred.

The thickness of the plating layer of the plating is not particularly limited, and for economic and aesthetic reasons, for example, the plating layer thickness is about 1 to 100nm, and preferably about 2 to 30 nm.

4. Anodic oxide layer

The anodic oxidation layer is obtained by anodizing the aluminum foil layer and is mainly used as a substrate of the metal-plated layer, and meanwhile, the holes formed by anodizing have good corrosion resistance and adsorbability and are beneficial to improving the adhesive force with the adhesive layer 1.

The anodic oxidation layer is obtained through a constant voltage or constant current anodic oxidation process, and the temperature of anodic oxidation bath solution is controlled to be 20-30 ℃. The aluminum foil layer is subjected to alkali washing to remove oil, water washing, acid washing neutralization, water washing, anodic oxidation, water washing and drying processes to obtain the aluminum foil. The thickness of the oxide layer is 10-2000 nm, preferably 20-1500nm, and more preferably 50-1000 nm. The oxide layer is observed by a Scanning Electron Microscope (SEM) to be uniformly distributed with holes, and the diameter of the holes is 30-140 nm, preferably 30-120nm, and more preferably 30-100 nm.

The anodic oxidation voltage range is 3-120V, and the current density is 50-300 mA/dm²The oxidation time is 5-60 min.

The electrolyte for anodic oxidation can adopt at least one of 0.1-0.5 mol/L phosphoric acid, sulfuric acid and oxalic acid; or the like, or, alternatively,

the electrolyte for anodic oxidation may employ at least one of phosphoric acid, sulfuric acid, oxalic acid, and at least one of an acid salt or fluoride corresponding to the acid radical.

5. Aluminium foil layer

The aluminum foil layer is a layer that not only improves the strength of the aluminum plastic film, but also has a function of preventing water vapor, oxygen, light, and the like from entering the battery. From the viewpoint of preventing generation of wrinkles or pinholes in the aluminum foil layer, it is more preferably formed of a soft aluminum alloy foil such as annealed aluminum (JIS H4160: 1994A8021H-O, JIS H4160: 1994A8079H-O, JIS H4000: 2014A8021P-O, JIS H4000: 2014A 8079P-O).

The thickness of the aluminum foil layer is not particularly limited as long as it can function as a barrier layer for water vapor or the like, and from the viewpoint of making the aluminum plastic film for a battery thinner and lighter, for example, the upper limit is about 100 μm or less, preferably about 80 μm or less, more preferably about 50 μm or less, and still more preferably about 40 μm or less, and the lower limit is preferably about 10 μm or more, and the range of the thickness can be about 10 to 100 μm, about 10 to 80 μm, preferably about 10 to 50 μm, and about 10 to 40 μm.

6. Second adhesive layer

The second adhesive layer is a layer provided between the aluminum foil layer and the heat seal layer as necessary to firmly adhere these layers.

The second adhesive layer is formed of an adhesive capable of bonding the aluminum foil layer and the heat seal layer. The adhesive used for forming the second adhesive layer 6 has the same adhesion mechanism, the same type of adhesive component, and the like as those of the adhesive layer 2. As the adhesive component used for the second adhesive layer 6, a polyolefin adhesive which is less swollen by an electrolytic solution is preferably used, and a polyolefin resin is preferably mentioned, and the second adhesive layer may be a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, from the viewpoint of making the thickness of the battery aluminum film thin and producing the battery aluminum film excellent in shape stability after molding. The acid-modified polyolefin is preferably a compound similar to the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin.

The curing agent is not particularly limited as long as it can cure the acid-modified polyolefin. Examples of the curing agent include epoxy curing agents, polyfunctional isocyanate curing agents, carbodiimide curing agents, and oxazoline curing agents.

The epoxy curing agent is not particularly limited as long as it is a compound having at least 1 epoxy group. Examples of the epoxy curing agent include epoxy resins such as bisphenol a diglycidyl ether, modified bisphenol a diglycidyl ether, novolac glycidyl ether, glycerol polyglycidyl ether, and polyglycerol polyglycidyl ether.

The polyfunctional isocyanate curing agent is not particularly limited as long as it is a compound having 2 or more isocyanate groups. Specific examples of the polyfunctional isocyanate curing agent include isophorone diisocyanate (IPDI), Hexamethylene Diisocyanate (HDI), Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), products obtained by polymerizing or urethanizing these isocyanates, mixtures thereof, and copolymers with other polymers.

The carbodiimide-based curing agent is not particularly limited as long as it is a compound having at least 1 carbodiimide group (-N ═ C ═ N —). The carbodiimide-based curing agent is preferably a polycarbodiimide compound having at least 2 or more carbodiimide groups.

The oxazoline-based curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the oxazoline-based curing agent include Epocros series products manufactured by Nippon catalyst Co.

The curing agent may be composed of 2 or more compounds from the viewpoint of improving the adhesion between the aluminum foil layer and the heat seal layer by the second adhesive layer.

The content of the curing agent in the resin composition forming the second adhesive layer is preferably in the range of about 0.1 to 50 mass%, more preferably about 0.1 to 30 mass%, and still more preferably about 0.1 to 10 mass%.

The thickness of the second adhesive layer is not particularly limited as long as it can function as an adhesive layer, but from the viewpoint of making the aluminum plastic film thinner and lighter, the thickness of the second adhesive layer is preferably about 1 to 10 μm, more preferably about 1 to 5 μm, and still more preferably about 1 to 3 μm.

7. Heat-sealing layer

The heat seal layer has a function of imparting heat sealability to the aluminum plastic film while having excellent chemical resistance to an electrolyte solution or the like used in a battery and having high corrosiveness.

The resin component used for the heat seal layer is not particularly limited, and examples thereof include polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin. That is, the heat-sealable layer may comprise a polyolefin backbone, and preferably comprises a polyolefin backbone. The analysis method is not particularly limited, and analysis can be performed by fourier infrared spectroscopy, gas chromatography-mass spectrometry, or the like. For example, when the maleic anhydride-modified polyolefin is measured by Fourier infrared spectroscopy, peaks derived from maleic anhydride are detected in the vicinity of 1760cm-1 wavenumber and 1780cm-1 wavenumber. Among them, when the acid modification degree is low, the peak is decreased and may not be detected. In this case, the analysis can be performed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include: polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene, linear low density polyethylene, etc.; polypropylene such as homopolypropylene, a block copolymer of polypropylene (for example, a block copolymer of propylene and ethylene), a random copolymer of polypropylene (for example, a random copolymer of propylene and ethylene), and the like; ethylene-butene-propylene terpolymers, and the like. Among these polyolefins, polyethylene and polypropylene are preferably cited.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin as a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, isoprene, and the like. Examples of the cyclic monomer as a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene, and specific examples thereof include cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic olefins are preferred, and norbornene is more preferred.

The acid-modified polyolefin is a polymer obtained by modifying the polyolefin by block polymerization or graft polymerization using an acid component such as a carboxylic acid. Examples of the acid component used for modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, and anhydrides thereof.

The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of monomers constituting the cyclic polyolefin with an α, β -unsaturated carboxylic acid or an anhydride thereof, or by block polymerization or graft polymerization of the α, β -unsaturated carboxylic acid or the anhydride thereof and the cyclic polyolefin. The cyclic polyolefin modified with a carboxylic acid is the same as above. The carboxylic acid used for the modification is the same as the acid component used for the modification of the polyolefin.

Among these resin components, polyolefins such as polypropylene and carboxylic acid-modified polyolefins are preferable, and polypropylene and acid-modified polypropylene are more preferable.

The heat-seal layer may be formed of 1 resin component alone, or may be formed of a blend polymer in which 2 or more resin components are combined. The heat-seal layer may be formed of only 1 layer, or may be formed of 2 or more layers using the same or different resin components.

The thickness of the heat seal layer is not particularly limited, but from the viewpoint of making the battery aluminum plastic film thinner and exhibiting excellent moldability, the upper limit is preferably about 80 μm or less, the amount of resin used can be reduced, and the cost can be reduced, and the lower limit is preferably about 10 μm or more, and the occurrence of pinholes can be sufficiently prevented, and therefore, the thickness is preferably about 10 μm to 80 μm, and more preferably about 10 to 40 μm.

8. Preparation method

The first adhesive layer and the base material layer are laminated on the metal-plated film layer of the colored laminate, and specifically, the lamination can be performed by a dry lamination method as follows: the adhesive for forming the first adhesive layer is applied to the base layer or the metal-plated film layer by a coating method such as an extrusion method, a gravure coating method, or a roll coating method, and dried, and then the metal-plated film layer or the base layer is laminated and the first adhesive layer is cured.

Next, the second adhesive layer and the heat seal layer are laminated on the aluminum foil layer of the colored laminate. The second adhesive layer and the heat seal layer are laminated on the aluminum foil layer, and the following methods can be mentioned: (1) a method of laminating the aluminum foil layer of the colored laminate by co-extrusion of the second adhesive layer and the heat seal layer (co-extrusion lamination method); (2) a method of forming a laminate obtained by laminating a second adhesive layer and a heat seal layer and laminating the laminate on the aluminum foil layer of the colored laminate by a heat lamination method; (3) a dry lamination method in which the resin composition for forming the second adhesive layer is applied to the aluminum foil layer of the colored laminate by a coating method such as a gravure coating method or a roll coating method, dried, and then the heat seal layer is laminated and the second adhesive layer is cured; (4) and a method (interlayer lamination method) in which the molten second adhesive layer is poured between the aluminum foil layer of the colored laminate and the heat seal layer formed in a sheet shape in advance, and the colored laminate and the heat seal layer are bonded via the second adhesive layer. Among these methods, the method (3) is preferred. In the case of the method (3), it is preferable that the resin composition forming the second adhesive layer is laminated on the aluminum foil layer and then dried at a temperature of about 60 to 120 ℃. When the heat-seal layer is a multilayer, the innermost layer of the heat-seal layer is preferably a layer formed by dry lamination or extrusion molding.

In addition, each layer constituting the laminate is subjected to surface activation treatment such as corona discharge treatment, sandblast treatment, ozone treatment and the like as necessary for improving or stabilizing film formability, lamination processing, 2-pass processing (packaging, embossing) suitability of the final product and the like.

9. Use of

The battery using the colored aluminum plastic film for battery of the present invention can be provided by covering a battery element having at least a positive electrode, a negative electrode and an electrolyte so that a flange portion (a region where heat seal layer resins are in contact with each other) can be formed at the edge of the battery element in a state where metal terminals connected to the positive electrode and the negative electrode are protruded outward, and sealing the heat seal layers of the flange portion by heat sealing. When the colored aluminum plastic film for a battery of the present invention is used to house a battery element, the heat seal layer resin portion of the colored aluminum plastic film for a battery of the present invention is used so as to be on the inside (the surface in contact with the battery element).

The colored aluminum plastic film for a battery of the present invention can be used for either a primary battery or a secondary battery, and is preferably used for a secondary battery. The type of secondary battery to which the colored aluminum plastic film for battery of the present invention is applied is not particularly limited, and examples thereof include lithium ion batteries, lithium ion polymer batteries, lead storage batteries, nickel-hydrogen storage batteries, nickel-cadmium storage batteries, nickel-iron storage batteries, nickel-zinc storage batteries, silver oxide-zinc storage batteries, metal air batteries, polyvalent cation batteries, and capacitors. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are preferable as an application object of the colored aluminum plastic film for batteries of the present invention.

Example 1

The embodiment of the invention relates to a preparation method of a color aluminum plastic film for battery packaging, which comprises the following steps:

and (3) removing oil from the aluminum foil layer (with the thickness of 40 mu m) by alkali washing, neutralizing by acid washing, and washing by water to obtain a clean aluminum foil layer.

The aluminum foil layer is subjected to double-sided anodization to obtain an anodized layer 4 (see fig. 3 for an anodization apparatus) including an ammeter 10, an anodization power source 11, a voltmeter 12,

graphite plate electrodes

13 and 16, an anodization bath 14, and an electrolyte 15 in the bath. The formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, a constant voltage of 5V is adopted, the anodic oxidation time is 10min, and the temperature is 25 ℃, so that an anodic oxidation layer 4 (thickness 1 μm) and an anodic oxidation layer (inner layer) 9 (thickness 1 μm) are obtained. The anodized aluminum foil layer shows the original color of the aluminum foil under naked eyes.

And (3) spraying gold (element symbol Au) on the anodic oxide layer 4 by using an ion sputtering instrument for 30s to obtain a gold-plated film layer 3 (with the thickness of 20nm) to form a laminated body A. At this time, although the plating metal is only gold (element symbol Au), the plating metal shows a purple color instead of the gold itself because of the difference in the time parameter of the anodization process, thereby forming a purple laminate a.

Next, a biaxially stretched nylon film (base layer 1, thickness 25 μm) was dry-laminated on the metal-plated film layer 3 of the laminate a via a 2-pack type urethane adhesive (first adhesive layer 2, thickness 3 μm), and was pressure-bonded by sandwiching between a rubber nip roll and a lamination roll heated to 100 ℃.

Then, one surface of the unstretched polypropylene film (hot-melt resin layer 7, thickness: 80 μm) was laminated to the other surface of the aluminum foil layer after dry lamination via a 2-pack type maleic anhydride-modified polypropylene adhesive (second adhesive layer 6, thickness: 3 μm).

Then, the laminate was aged at 75 ℃ for 4 days to obtain a purple aluminum plastic film for a battery, having a total thickness of 153 μm and comprising a laminate of a base material layer 1, a first adhesive layer 2, a plated metal film layer 3, an aluminum foil anodized layer 4, an intermediate layer 5, an aluminum foil anodized layer (inner layer) 9, a second adhesive layer 6 and a hot-melt resin layer 7, which were laminated in this order, having a structure shown in FIG. 1.

Example 2

Then, one surface of the aluminum foil layer was laminated on one surface of an unstretched polypropylene film (hot-melt resin layer 7, thickness: 80 μm) with a 2-pack type maleic anhydride-modified polypropylene adhesive (second adhesive layer 6, thickness: 3 μm) interposed therebetween to form a laminate B.

Next, on the other side of the aluminum foil layer of the laminate B, a single-side anodizing process (an anodizing apparatus shown in fig. 4) including an ammeter 10, an anodizing power supply 11, a voltmeter 12, a graphite plate electrode 13, an anodizing bath 14, and an electrolyte 15 in the bath was performed. The formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, the constant voltage is 5V, the anodic oxidation time is 50min, and the temperature is 25 ℃, so that an anodic oxidation layer 4 (the thickness is 1 μm) is obtained.

Next, gold (element symbol Au) was sprayed on the anodized layer 4 for 30 seconds by an ion sputtering apparatus to obtain a gold-plated film layer 3 (thickness 20nm) in which the color of the plating metal was yellow instead of the color of the gold body, thereby forming a yellow laminate C.

Next, a biaxially stretched nylon film (base layer 1, thickness 25 μm) was dry-laminated on the plated metal film layer 3 via a 2-pack type urethane adhesive (first adhesive layer 2, thickness 3 μm), and sandwiched between a rubber nip roller and a laminating roller heated to 100 ℃.

Then, the resulting film was aged at 75 ℃ and heated for 4 days to obtain a yellow aluminum plastic film for a battery, having a total thickness of 152 μm and comprising a laminate of a base material layer 1, a first adhesive layer 2, a plated metal film layer 3, an aluminum foil anodized layer 4, an intermediate layer, a second adhesive layer 6 and a hot-melt resin layer 7, which were laminated in this order, having a structure shown in FIG. 2.

Example 3

The aluminum foil layer is subjected to double-sided anodization to provide an anodized layer 4 (see fig. 3 for an anodization apparatus). The formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, and the constant current is 800mA/dm²Anodizing time of 5min at 25 ℃ to obtain an anodized layer 4 (thickness 1 μm) and an aluminum foil anodized layer (inner layer) 9 (thickness 1 μm).

And (3) spraying gold (element symbol Au) on the anodic oxide layer 4 by using an ion sputtering instrument for 30s to obtain a gold-plated film layer 3 (with the thickness of 20nm) to form a laminated body A. At this time, although the plating metal has only one element of gold (element symbol Au), the plating metal shows a blue color instead of the color of the gold itself because of the difference in the time parameter of the anodization process, thereby forming a blue laminate a.

Then, one surface of the unstretched polypropylene film (hot-melt resin layer 7, thickness: 40 μm) was laminated to the other surface of the aluminum foil layer after dry lamination via a 2-pack type maleic anhydride-modified polypropylene adhesive (second adhesive layer 6, thickness: 3 μm).

Then, the resultant was aged at 75 ℃ for 4 days to obtain a blue-colored aluminum plastic film for a battery, having a total thickness of 113 μm and comprising a laminate of a base material layer 1, a first adhesive layer 2, a plated metal film layer 3, an aluminum foil anodized layer 4, an intermediate layer, an aluminum foil anodized layer (inner layer) 9, a second adhesive layer 6 and a hot-melt resin layer 7, which were laminated in this order, having a structure shown in FIG. 1.

Example 4

Then, one surface of the aluminum foil layer was laminated on one surface of an unstretched polypropylene film (hot-melt resin layer 7, thickness: 40 μm) with a 2-pack type maleic anhydride-modified polypropylene adhesive (second adhesive layer 6, thickness: 3 μm) interposed therebetween to form a laminate B.

Next, on the other surface of the aluminum foil layer of the laminate B, a single-sided anodic oxidation process was performed (see fig. 4 for an anodic oxidation apparatus). The formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, and the constant current is 150mA/dm²Anodizing time was 30min at 25 ℃ to obtain an anodized layer 4 (thickness 1 μm).

Next, platinum (element symbol Pt) was sprayed on the anodized layer 4 for 30 seconds by an ion sputtering apparatus to obtain a gold-plated film layer 3 (thickness 20nm) in which the color of the plating metal was not that of the platinum body but purple, thereby forming a purple laminate C.

Then, the resulting film was aged at 75 ℃ and heated for 4 days to obtain a purple aluminum plastic film for a battery, having a total thickness of 112 μm and comprising a laminate of a base material layer 1, a first adhesive layer 2, a plated metal film layer 3, an aluminum foil anodized layer 4, an intermediate layer, a second adhesive layer 6 and a hot-melt resin layer 7, which were laminated in this order, having a structure shown in FIG. 2.

Example 5

As an anodic oxidation process, the formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, and a constant current of 130mA/dm is adopted²A green aluminum-plastic film for a battery was obtained in the same manner as in example 1, except that the anodizing time was 30 min.

Example 6

As an anodic oxidation process, the formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, the constant voltage is 120V, and the anodic oxidation time is 10 min. Except for this, a red aluminum plastic film for a battery was obtained in the same manner as in example 1.

Example 7

As an anodic oxidation process, the formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, and a constant current of 250mA/dm is adopted² Anodizing time 10 min. Except for this, an orange aluminum plastic film for a battery was obtained in the same manner as in example 1.

Example 8

As an anodic oxidation process, the formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, and a constant current of 250mA/dm is adopted²Anodizing time 20 min. Except for this, a yellow aluminum plastic film for a battery was obtained in the same manner as in example 1.

Example 9

As the anodic oxidation process, the electrolyte formula of anodic oxidation is 0.1mol/L phosphoric acid and 2g/L sodium fluoride, and a constant current of 250mA/dm is adopted²Anodizing time 30 min. Except for this, a gray aluminum-plastic film for batteries was obtained in the same manner as in example 1.

Example 10

As an anodic oxidation process, the formulation of the electrolyte for anodic oxidation is 0.1mol/L phosphoric acid, and a constant current of 150mA/dm is adopted²Anodizing time 40 min. Except for this, a green aluminum plastic film for a battery was obtained in the same manner as in example 4.

The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A colored aluminum plastic film for battery packaging is characterized in that: the aluminum foil comprises a substrate layer, a first adhesive layer, a metal-plated film layer, an aluminum foil layer, a second adhesive layer and a heat-sealing layer from outside to inside in sequence;

2. The colored aluminum plastic film for battery encapsulation according to claim 1, wherein: the thickness of the plating metal film layer is 1-100 nm, the plating metal comprises gold, platinum and chromium, and the particle size of the plating metal is 1-100 nm.

3. The colored aluminum plastic film for battery encapsulation according to claim 1, wherein: the thickness of the anodic oxidation layer is 10-2000 nm, and holes with the aperture of 30-140 nm are uniformly distributed on the anodic oxidation layer.

4. The colored aluminum plastic film for battery encapsulation according to claim 1, wherein: the thickness of the middle layer is 10-100 mu m.

5. The colored aluminum plastic film for battery encapsulation according to claim 1, wherein: the thickness of the substrate layer is not more than 30 μm, and the substrate layer comprises polyamide, polyester, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenolic resin, polyetherimide, polyimide, polycarbonate, or a mixture or copolymer of the above materials.

6. The colored aluminum plastic film for battery encapsulation according to claim 1, wherein: the first adhesive layer has a thickness of 1 to 10 μm, the second adhesive layer uses a polyolefin adhesive, and the second adhesive layer has a thickness of 1 to 10 μm.

7. The colored aluminum plastic film for battery encapsulation according to claim 1, wherein: the thickness of the heat sealing layer is not more than 80 μm.

8. The method for preparing a colored aluminum plastic film for battery encapsulation according to any one of claims 1 to 7, wherein: the method comprises the following steps:

(1) preparing an aluminum foil layer: anodizing the aluminum foil on one side or two sides to obtain an aluminum foil layer consisting of an intermediate layer and an anodic oxidation layer; the anodic oxidation voltage is 3-120V or the current density is 50-800 mA/dm²The oxidation time is 5-60 min, the electrolyte comprises 0.1-0.5 mol/L of at least one of phosphoric acid, sulfuric acid and oxalic acid, and the temperature of the electrolyte tank is 20-30 ℃;

9. The method for preparing a colored aluminum plastic film for battery encapsulation according to claim 8, wherein: the aluminum foil in the step (1) is subjected to annealing treatment and is subjected to pretreatment of alkali washing for removing oil, water washing, acid washing for neutralization and water washing before anodic oxidation.

10. The method for preparing a colored aluminum plastic film for battery encapsulation according to claim 8, wherein: and (3) and (4) realizing interlayer connection by adopting a dry lamination method or an extrusion molding method.