WO2020071490A1 - Packaging material for electricity storage devices, electricity storage device, method for producing said packaging material for electricity storage devices, and method for producing said electricity storage device - Google Patents

Abstract

The present invention provides a packaging material for electricity storage devices, which has high adhesion between a base material layer and a barrier layer even though a layer containing a material that enables the formation of an image is arranged between the base material layer and the barrier layer, and which does not require enhancement of the output of laser light and therefore suppresses deterioration of the base material layer 1 due to irradiation of the laser light. This packaging material for electricity storage devices is configured of a multilayer body that is sequentially provided with at least a base material layer, an adhesive layer, a barrier layer and a thermally fusible resin layer in this order; the adhesive layer is in area contact with the barrier layer; and the adhesive layer contains a material that enables the formation of an image by means of irradiation of laser light.

Description

Packaging material for power storage device, power storage device, and method of manufacturing these

The present invention relates to a packaging material for a power storage device, a power storage device, and a method for manufacturing these.

Conventionally, various types of power storage devices have been developed, but in all power storage devices, a packaging material is an indispensable member for sealing power storage device elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been frequently used as packaging for power storage devices.

On the other hand, in recent years, as the performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, and the like has increased, various shapes have been required for the power storage devices, and thinner and lighter weights have been required. However, a metal packaging material for a power storage device, which has been frequently used in the past, has a drawback that it is difficult to keep up with diversification of shapes and there is a limit to weight reduction.

Therefore, in recent years, as a packaging material for an electricity storage device that can be easily processed into various shapes and can be made thinner and lighter, a base material layer on the outer layer side, a barrier layer, and a heat-fusible resin layer on the inner layer side have been developed. Are sequentially laminated (see, for example, Patent Document 1). In such a packaging material for an electric storage device, generally, a concave portion is formed by cold molding, and an electric storage device element such as an electrode or an electrolytic solution is arranged in a space formed by the concave portion. By heat-sealing the layers, an electricity storage device in which the electricity storage device element is accommodated inside the electricity storage device packaging material is obtained.

In various packaging materials composed of the above laminates, ink is printed on the surface of the base material layer to form barcodes, patterns, characters, etc., and is adhered on the base material layer on the printed side. A method of printing on a packaging material by a method of laminating an agent and a barrier layer (generally called back printing) has been widely adopted. However, if such a printed surface exists between the base layer and the barrier layer on the outer layer side, the adhesion between the base layer and the barrier layer is reduced, and delamination is likely to occur between the layers. In particular, since the power storage device to which the power storage device packaging material is applied is required to have high security, such a method of printing by back printing is avoided in the power storage device packaging material. Therefore, conventionally, when forming a print such as a bar code on the packaging material for an electric storage device, a method of attaching a seal formed with the print to the surface of the outer layer is generally adopted.

However, when the seal on which the print is formed is attached to the surface of the outer layer, the thickness and weight of the power storage device packaging material increase. In view of the recent trend of further thinning and lightening of the power storage device packaging material, there is also a method of printing by printing ink directly on the surface of the outer layer of the power storage device packaging material.

パ ッ ド As a method of printing by printing ink directly on the surface of the outer layer of the packaging material for a power storage device, for example, pad printing (also referred to as tampo printing) or inkjet printing is known. Pad printing is the following printing method. First, ink is poured into a concave portion of a flat plate on which a pattern to be printed is etched. Next, a silicon pad is pressed from above the concave portion to transfer the ink to the silicon pad. Next, the ink transferred to the surface of the silicon pad is transferred to a printing target to form a print on the printing target. In such pad printing, the ink is transferred to the printing object using an elastic silicon pad or the like, so that it is easy to print on the surface of the formed power storage device packaging material, and the power storage device element is used for the power storage device. After sealing with a packaging material, there is an advantage that printing can be performed on the electricity storage device. In addition, similar advantages are obtained in ink jet printing.

However, when printing is performed directly on the surface of the outer layer of the packaging material for an electric storage device with ink, the printing is peeled off when an organic solvent or the like adheres to the printed portion or rubs the printed portion in a subsequent process. Is easy to occur.

JP 2008-287971 A

Instead of a method of performing printing with ink on the surface of the outer layer of the power storage device packaging material, a material that enables image formation on the power storage device packaging material by laser light irradiation between the outer layer and the barrier layer is included. There is also a method of forming an image inside a base layer of a packaging material for an electric storage device by providing a printing layer and irradiating the printing layer with laser light.

However, in the case where a printing layer containing a material capable of forming an image is provided on the packaging material for an electric storage device by irradiation with a laser beam, there is a problem that the adhesion between the base material layer and the barrier layer is reduced. That is, the printing layer contains a material capable of forming an image, and is a thinly formed layer. Since the content of the binder resin is small and the adhesiveness is poor, the printing layer is formed between the base layer and the barrier layer. The adhesiveness is reduced by providing. Further, for example, when an adhesive layer is provided between the printing layer and the barrier layer in order to solve the problem of a decrease in adhesion due to the provision of the printing layer, the number of manufacturing steps of the power storage device packaging material and the power storage device increases. There is a problem of doing.

Also, in the case where a printing layer containing a material capable of forming an image by irradiation with laser light is not provided, image formation is possible by increasing the output of laser light, but the minimum amount of laser light capable of forming an image properly can be obtained. When the output is increased, there is also a problem that the base material layer through which the laser light has passed tends to deteriorate.

Under such circumstances, the present invention, between the base layer and the barrier layer, despite the fact that a layer containing a material capable of forming an image is provided, between the base layer and the barrier layer Since it has high adhesiveness and does not need to increase the output of laser light (the minimum output of laser light capable of forming an image properly can be reduced), the base by image formation using laser light is used. A main object is to provide a packaging material for an electric storage device in which deterioration of a material layer is suppressed. Further, another object of the present invention is to provide a method for manufacturing the packaging material for a power storage device, a power storage device using the packaging material for a power storage device, and a method for manufacturing the power storage device.

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, at least a base layer, an adhesive layer, a barrier layer, and a laminate having a heat-fusible resin layer in this order, the adhesive layer is in contact with the barrier layer, the adhesive The packaging material for an electricity storage device whose layer contains a material capable of forming an image by irradiation with laser light has a structure in which a layer containing a material capable of forming an image is provided between a base layer and a barrier layer. The high adhesion between the substrate layer and the barrier layer, and it is not necessary to increase the output of the laser light, so that the deterioration of the substrate layer due to the image formation using the laser light is suppressed. Was found. The present invention has been completed by further study based on these findings.

That is, the present invention provides a packaging material for a power storage device and a power storage device according to the following aspects.
Item 1. At least a positive electrode, a negative electrode, and a power storage device element including an electrolyte are housed in a package made of a power storage device packaging material, a power storage device,
The packaging material for the electricity storage device is at least composed of a laminate including a base layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer in this order,
The adhesive layer is in contact with the barrier layer,
The power storage device, wherein the adhesive layer includes a material that can form an image by irradiation with a laser beam.
Item 2. 2. The electricity storage device according to claim 1, wherein the adhesive layer has a content of the material capable of forming an image by laser light irradiation of 0.1 to 50% by mass.
Item 3. Item 3. The power storage device according to Item 1 or 2, wherein the material capable of forming an image by irradiation with a laser beam includes a bismuth-based compound.
Item 4. Item 4. The power storage device according to any one of Items 1 to 3, wherein the material capable of forming an image by irradiation with a laser beam includes a black pigment.
Item 5. Item 5. The power storage device according to any one of Items 1 to 4, wherein an image is formed on the adhesive layer.
Item 6. Item 6. The power storage device according to any one of Items 1 to 5, wherein an adhesive strength between the base layer and the barrier layer is 3 N / 15 mm or more.
Item 7. Item 7. The power storage device according to any one of Items 1 to 6, wherein an image is formed on the adhesive layer.
Item 8. Item 7. The power storage device according to any one of Items 1 to 6, wherein an image visible from the outside is formed.
Item 9. At least, a base layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer, which is composed of a laminate including in this order,
The adhesive layer is in contact with the barrier layer,
The packaging material for an electric storage device, wherein the adhesive layer includes a material that enables an image to be formed by irradiation with a laser beam.
Item 10. At least, a step of laminating the base material layer, the adhesive layer, the barrier layer, and the heat-fusible resin layer in this order,
The adhesive layer is in contact with the barrier layer,
The adhesive layer includes a material that enables image formation by irradiation with laser light,
A method for producing a packaging material for a power storage device.
Item 11. A housing step of housing at least a positive electrode, a negative electrode, and a power storage device element including an electrolyte in a package made of the power storage device packaging material according to item 9,
Before or after the accommodation step, irradiating the adhesive layer with a laser beam to form an image,
A method for manufacturing a power storage device, comprising:
Item 12. Item 12. The method for manufacturing a power storage device according to Item 11, wherein the laser light is a YAG laser light, a YVO ₄ laser light, or a fiber laser light.

According to the present invention, high adhesion between the base material layer and the barrier layer is achieved despite the fact that a layer containing a material capable of forming an image is provided between the base material layer and the barrier layer. Since there is no need to increase the output of the laser light, it is possible to provide a packaging material for an electric storage device in which deterioration of the base layer due to image formation using laser light is suppressed. Further, according to the present invention, it is possible to provide a method for manufacturing the power storage device packaging material, a power storage device using the power storage device packaging material, and a method for manufacturing the power storage device.

It is a schematic diagram which shows an example of the cross-section of the packaging material for electrical storage devices of this invention. It is a schematic diagram which shows an example of the cross-section of the packaging material for electrical storage devices of this invention. It is a schematic diagram which shows an example of the cross-section of the packaging material for electrical storage devices of this invention. SEM image (scanning electron microscope) of a cross section (a portion irradiated with laser) of the base material layer (biaxially stretched iron film) / adhesive layer / barrier layer (aluminum alloy foil) in the packaging material for an electric storage device of Example 1. Is an image obtained by observing the cross section.

The packaging material for an electricity storage device of the present invention includes at least a substrate layer, an adhesive layer, a barrier layer, and a laminate including a heat-fusible resin layer in this order, and the adhesive layer includes a barrier layer and The adhesive layers are in contact with each other, and include a material capable of forming an image by irradiation with a laser beam. Hereinafter, a packaging material for a power storage device, a method for manufacturing the packaging material for a power storage device, a power storage device using the packaging material for a power storage device, and a method for manufacturing a power storage device of the present invention will be described in detail.

In this specification, the numerical range indicated by “to” means “more than” and “less than or equal to”. For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. Laminated Structure of Energy Storage Device Packaging Material As shown in FIGS. 1 to 3, the energy storage device packaging material of the present invention comprises at least a base material layer 1, an adhesive layer 2, a barrier layer 3, and a heat-fusible resin. It consists of a laminate having layers 4 in this order. In the packaging material for an electric storage device of the present invention, the base material layer 1 is on the outermost layer side, and the heat-fusible resin layer 4 is on the innermost layer. That is, at the time of assembling the power storage device, the heat-fusible resin layers 4 located on the periphery of the power storage device element are heat-sealed to seal the power storage device element, whereby the power storage device element is sealed.

に お い て In the packaging material for an electric storage device of the present invention, the adhesive layer 2 is in contact with the barrier layer 3. In addition, the adhesive layer 2 may or may not be in contact with the base material layer 1. For example, an adhesive layer containing no material capable of forming an image may exist between the base material layer 1 and the adhesive layer 2. Deterioration of the base material layer 1 due to image formation using laser light without improving the adhesion between the base material layer 1 and the barrier layer 3 via the adhesive layer 2 and without increasing the output of laser light. It is preferable that the adhesive layer 2 is in contact with the base material layer 1 from the viewpoint of suppressing the above.

As shown in FIGS. 2 and 3, the packaging material for an electric storage device of the present invention is bonded between a barrier layer 3 and a heat-fusible resin layer 4 as necessary for the purpose of enhancing their adhesiveness. A layer 5 may be provided. Further, as shown in FIG. 3, a surface coating layer 6 may be provided outside the base material layer 1 (on the side opposite to the heat-fusible resin layer 4) as necessary.

The thickness of the laminate constituting the packaging device 10 for a power storage device of the present invention is not particularly limited, but from the viewpoint of reducing the thickness of the packaging material for a power storage device and increasing the energy density of the power storage device, for example, 180 μm The thickness is preferably 150 μm or less, more preferably about 60 to 180 μm, and still more preferably about 60 to 150 μm.

2. Each layer forming the packaging material for a power storage device [base layer 1]
In the present invention, the base material layer 1 is a layer provided for the purpose of, for example, exhibiting a function as a base material of a packaging material for an electricity storage device. The base material layer 1 is located on the outer layer side of the packaging material for a power storage device.

素材 The material for forming the base material layer 1 is not particularly limited as long as it has a function as a base material, that is, at least an insulating property. The base layer 1 can be formed using, for example, a resin, and the resin may include an additive described below.

When the base layer 1 is formed of a resin, the base layer 1 may be, for example, a resin film formed of a resin, or may be formed by applying a resin. The resin film may be an unstretched film or a stretched film. Examples of the stretched film include a uniaxially stretched film and a biaxially stretched film, and a biaxially stretched film is preferable. Examples of a stretching method for forming a biaxially stretched film include a sequential biaxial stretching method, an inflation method, and a simultaneous biaxial stretching method. Examples of the method for applying the resin include a roll coating method, a gravure coating method, and an extrusion coating method.

樹脂 Examples of the resin forming the base layer 1 include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, and phenol resin, and modified products of these resins. The resin forming the base material layer 1 may be a copolymer of these resins or a modified product of the copolymer. Further, a mixture of these resins may be used.

樹脂 As the resin forming the base material layer 1, among these, polyester and polyamide are preferable.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester. Examples of the copolymerized polyester include a copolymerized polyester mainly composed of ethylene terephthalate as a repeating unit. Specifically, a copolymer polyester (hereinafter abbreviated to polyethylene (terephthalate / isophthalate)) which is polymerized with ethylene isophthalate with ethylene terephthalate as a main repeating unit, polyethylene (terephthalate / adipate), polyethylene (terephthalate / Sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), polyethylene (terephthalate / decanedicarboxylate) and the like. These polyesters may be used alone or in a combination of two or more.

Examples of the polyamide include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid. Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamide such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (I represents isophthalic acid and T represents terephthalic acid) containing a structural unit derived therefrom, polyamide MXD6 (polymethacrylate) Polyamide containing an aromatic compound such as silylene adipamide; alicyclic polyamide such as polyamide PACM6 (polybis (4-aminocyclohexyl) methane adipamide); and a lactam component or an isocyanate component such as 4,4'-diphenylmethane-diisocyanate. Polyamides obtained by copolymerizing, copolymerized polyamide and polyester or polyalkylene polyester amide copolymer is a copolymer of a polyether glycol and a polyether ester amide copolymers, polyamides such as a copolymer thereof. These polyamides may be used alone or in a combination of two or more.

The base material layer 1 preferably includes at least one of a polyester film, a polyamide film, and a polyolefin film, and preferably includes at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, It is more preferable to include at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film. It is further preferable that at least one of the biaxially stretched polypropylene films is included.

The base material layer 1 may be a single layer or may be composed of two or more layers. When the base material layer 1 is composed of two or more layers, the base material layer 1 may be a laminate in which a resin film is laminated with an adhesive or the like, or may be co-extruded with a resin to form two or more layers. It may be a laminated body of a resin film obtained. In addition, a laminate of resin films in which two or more layers are formed by co-extrusion of a resin may be used as the base material layer 1 without stretching, or may be used as the base material layer 1 by uniaxial stretching or biaxial stretching.

In the base layer 1, specific examples of a laminate of two or more resin films include a laminate of a polyester film and a nylon film, a laminate of two or more nylon films, and a laminate of two or more polyester films. Preferred are a laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more stretched nylon films, and a laminate of two or more stretched polyester films. For example, when the base material layer 1 is a laminate of a two-layer resin film, a laminate of a polyester resin film and a polyester resin film, a laminate of a polyamide resin film and a polyamide resin film, or a laminate of a polyester resin film and a polyamide resin film. A laminate is preferable, and a laminate of a polyethylene terephthalate film and a polyethylene terephthalate film, a laminate of a nylon film and a nylon film, or a laminate of a polyethylene terephthalate film and a nylon film is more preferable. When the base material layer 1 is a laminate of two or more resin films, for example, the polyester resin is hardly discolored when the electrolytic solution adheres to the surface. It is preferably located on the outermost layer.

When the base material layer 1 is a laminate of two or more resin films, the two or more resin films may be laminated via an adhesive. Preferred adhesives include those similar to the adhesive exemplified in the adhesive layer 2 described later. The method for laminating two or more resin films is not particularly limited, and a known method can be employed. Examples thereof include a dry lamination method, a sandwich lamination method, an extrusion lamination method, and a thermal lamination method. A lamination method may be used. When laminating by a dry lamination method, it is preferable to use a polyurethane adhesive as the adhesive. At this time, the thickness of the adhesive is, for example, about 2 to 5 μm. Further, an anchor coat layer may be formed on the resin film and laminated. The anchor coat layer may be the same as the adhesive exemplified in the adhesive layer 2 described later. At this time, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 μm.

Further, even if additives such as a lubricant, a flame retardant, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent are present on at least one of the surface and the inside of the base material layer 1. Good. Only one type of additive may be used, or two or more types may be mixed and used.

に お い て In the present invention, it is preferable that a lubricant is present on the surface of the base material layer 1 from the viewpoint of enhancing the moldability of the packaging material for an electric storage device. The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Specific examples of the amide-based lubricant include, for example, saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylolamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, fatty acid ester amide, aromatic bisamide and the like. Specific examples of the saturated fatty acid amide include lauric amide, palmitic amide, stearic amide, behenic amide, and hydroxystearic amide. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitic amide, N-stearyl stearamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide, and the like. Specific examples of methylolamide include methylol stearamide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearin Acid amide, hexamethylenebisbehenamide, hexamethylenehydroxystearic acid amide, N, N'-distearyladipamide, N, N'-distearylsebacic amide and the like. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bis oleic acid amide, N, N'-dioleyl adipamide, N, N'-dioleyl sebacic amide And the like. Specific examples of the fatty acid ester amide include stearoamidoethyl stearate. Specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N, N'-distearylisophthalic acid amide, and the like. One type of lubricant may be used alone, or two or more types may be used in combination.

When a lubricant is present on the surface of the base material layer 1, the amount thereof is not particularly limited, but is preferably about 3 mg / m ² or more, more preferably about 4 to 15 mg / m ² , and still more preferably 5 to 14 mg / m ^2. / M ² .

The lubricant present on the surface of the base material layer 1 may be obtained by oozing out the lubricant contained in the resin constituting the base material layer 1 or by applying the lubricant to the surface of the base material layer 1. You may.

厚 み The thickness of the substrate layer 1 is not particularly limited as long as it functions as a substrate, and is, for example, about 3 to 50 μm, preferably about 10 to 35 μm. When the base material layer 1 is a laminate of two or more resin films, the thickness of the resin film constituting each layer is preferably about 2 to 25 μm, respectively.

に お い て In the present invention, it is preferable to select a substrate through which the wavelength of the laser beam is easily transmitted as the substrate layer 1. When the laser light used for image formation is, for example, a laser light having a wavelength of 1067 nm, it is more preferable to select the base material layer 1 having a light transmittance of 1067 nm of 80% or more. As such a base material layer 1, a polyamide film, a polyester film, or the like is preferable. The light transmittance of the base material layer 1 can be measured by, for example, an ultraviolet-visible spectrophotometer (UV-1900) manufactured by Shimadzu Corporation.

[Adhesive layer 2]
In the packaging material 10 for an electric storage device of the present invention, the adhesive layer 2 is a layer that firmly adheres the base layer 1 and the barrier layer 3 and that can form an image by irradiating the adhesive layer 2 with laser light. is there. The adhesive layer 2 is provided between the base material layer 1 and the barrier layer 3 and is in contact with the barrier layer 3. The adhesive layer 2 may or may not be in contact with the base material layer 1. For example, an adhesive layer containing no material capable of forming an image may exist between the base material layer 1 and the adhesive layer 2. The adhesion between the base material layer 1 and the barrier layer 3 via the adhesive layer 2 is improved, and the deterioration of the base material layer 1 due to image formation using laser light is not required without increasing the output of laser light. From the viewpoint of suppression, it is preferable that the surface is in contact with the base material layer 1.

In the packaging material 10 for an electricity storage device of the present invention, the adhesive layer 2 is a layer on which an image can be formed by irradiating a laser beam, and may be in a state where an image is formed on the adhesive layer 2, A state in which no image is formed on the layer 2 may be employed. Even when an image is not formed on the adhesive layer 2 of the power storage device packaging material 10, an image can be formed on the adhesive layer 2 by irradiating the adhesive layer 2 with laser light. In the packaging material 10 for an electricity storage device of the present invention, the color or brightness of the portion irradiated with the laser light changes due to the laser light irradiation, and it is visually recognized that an image is formed. That is, in the power storage device, the image formed outside is visually confirmed.

The adhesive layer 2 is formed of an adhesive containing a material capable of forming an image on the power storage device packaging material 10 by irradiation with a laser beam, and an adhesive component capable of adhering the base layer 1 and the barrier layer 3. You.

材料 As a material that can form an image by irradiation with laser light, a conventionally known material can be used, and examples thereof include a bismuth compound and a black pigment. In the present invention, it is preferable to use, as the material, a coloring material that is colored by irradiation with laser light.

ビ ス As a color-forming material for suitably forming a color by irradiation with a laser beam, a bismuth-based compound is preferably used.

The bismuth-based compound is not particularly limited, and examples thereof include an organic salt of bismuth and / or an inorganic salt of bismuth. Specifically, for example, bismuth oxide; bismuth nitrate compounds such as bismuth nitrate and bismuth oxynitrate; bismuth halide compounds such as bismuth chloride; bismuth oxychloride, bismuth sulfate, bismuth acetate, bismuth citrate, bismuth hydroxide , Bismuth titanate, bismuth subcarbonate, and the like are preferable as a coloring material that is colored by a low-output laser beam. Among them, bismuth hydroxide, bismuth oxide, bismuth subcarbonate, and bismuth nitrate are particularly preferably used. As the bismuth-based compound, only one kind may be used, or two or more kinds may be used in combination.

When a bismuth-based compound is used in the adhesive layer 2, the content of the bismuth-based compound contained in the adhesive layer 2 is not particularly limited, but the adhesive layer 2 contains a material capable of forming an image. Nevertheless, high adhesion between the base material layer 1 and the barrier layer 3 via the adhesive layer 2 is exhibited, and furthermore, deterioration of each layer such as the base material layer 1 due to laser light irradiation is minimized. From the viewpoint of suppressing the concentration, the lower limit is preferably about 0.1% by mass or more, more preferably about 1% by mass or more, further preferably about 2% by mass or more, and the upper limit is preferably about 50% by mass or less. And more preferably about 30% by mass or less, further preferably about 25% by mass or less, and the preferable range is about 0.1 to 50% by mass, about 0.1 to 30% by mass, 0.1 to 25% by mass. About 1% to 50% The amount% of about 1 to 30 wt%, about 1 to 25 wt%, about 2 to 50 wt%, about 2 to 30 wt%, about 2 to 25% by weight thereof.

In the present invention, it is preferable to use a black pigment such as carbon black in combination with a bismuth-based compound as a material capable of forming an image by irradiation with laser light. By using a bismuth-based compound and a black pigment together, it is possible to form an image on the adhesive layer 2 by irradiating a laser beam, so that the deterioration of the base layer 1 due to the image formation using the laser beam is suppressed. It can be suitably suppressed, and the adhesion between the base material layer and the barrier layer can be increased. Further, by using a black pigment, it is possible to form an image of another color (for example, white) by irradiating the adhesive layer 2 colored with a black color with laser light. When a bismuth-based compound and a black pigment are used in combination, it is considered that the sublimation speed of the black pigment is increased by the absorption of the bismuth laser light, and as a result, it is possible to form an image with lower energy laser light.

When a black pigment is used in the adhesive layer 2, the total content of the material capable of forming an image by irradiating a laser beam is not particularly limited, but includes a material capable of forming an image of the adhesive layer 2. Nevertheless, a high adhesion between the base material layer 1 and the barrier layer 3 is exhibited, the adhesive layer 2 is made black, and furthermore, the deterioration of each layer such as the base material layer due to the irradiation of the laser beam is suppressed. From the viewpoint of minimization, the lower limit is preferably about 0.1% by weight or more, more preferably about 1% by weight or more, further preferably about 2% by weight or more, and the upper limit is preferably about 50% by weight. % Or less, more preferably about 30% by weight or less, further preferably about 25% by weight or less, and the preferable range is about 0.1 to 50% by weight, about 0.1 to 30% by weight, 0.1 to About 25% by mass, 1 About 50 wt%, about 1 to 30 wt%, about 1 to 25 wt%, about 2 to 50 wt%, about 2 to 30 wt%, about 2 to 25% by weight thereof.

In the adhesive layer 2, as a particularly preferable embodiment of the material capable of forming an image by irradiation with laser light, the material capable of forming an image by irradiation of laser light may include only a bismuth-based compound (particularly, bismuth oxide) of 4 to 4. Those containing about 30% by mass are exemplified. In the case where an image of another color (for example, white) is formed by irradiating a laser beam to the adhesive layer 2 colored black, it is possible to form an image by irradiating the laser beam. Examples of the material to be used include a material containing about 1 to 10% by mass of a bismuth-based compound (particularly, bismuth oxide) and about 10 to 20% by mass of a black pigment (particularly, carbon black).

When a bismuth-based compound and a black pigment are used in combination in the adhesive layer 2, the base material layer via the adhesive layer 2 is formed despite the fact that the adhesive layer 2 contains a material capable of forming an image. From the viewpoint of exhibiting high adhesiveness between the first and barrier layers 3 and increasing the output of the laser beam, there is no need to increase the output of the laser beam. The mass ratio of the bismuth compound to the black pigment contained in the agent layer 2 (bismuth compound: black pigment) is preferably about 1: 0.5 to 15, more preferably about 1: 0.8 to 15, More preferably, the ratio is about 1: 1 to 8.

着色 Coloring agents such as dyes and pigments, clays, and the like can be used as other materials capable of forming an image by laser beam irradiation. Specifically, yellow iron oxide, inorganic lead compounds, manganese violet, metal compounds such as cobalt violet, metals such as mercury, cobalt, copper, nickel, pearlescent pigments, silicon compounds, mica, kaolins, silica sand, Diatomaceous earth, talc, titanium oxide-coated mica, tin dioxide-coated mica, antimony-coated mica, tin + antimony-coated mica, tin + antimony + titanium oxide-coated mica can also be used.

The total content of the material capable of forming an image by irradiation with a laser beam in the adhesive layer 2 is not particularly limited. From the viewpoint of exhibiting high adhesion between the base material layer 1 and the barrier layer 3 via the agent layer 2 and further minimizing the deterioration of each layer such as the base material layer 1 due to laser light irradiation, The lower limit is preferably about 0.1% by weight or more, more preferably about 1% by weight or more, and still more preferably about 2% by weight or more, and the upper limit is preferably about 50% by weight or less, more preferably about 50% by weight or less. It is at most 30% by mass, more preferably at most about 25% by mass, and the preferred range is about 0.1 to 50% by mass, about 0.1 to 30% by mass, about 0.1 to 25% by mass, About 50% by mass, 1 to 30 The amount% of about 1 to 25 wt%, about 2 to 50 wt%, about 2 to 30 wt%, about 2 to 25% by weight thereof.

The adhesive layer 2 may also include one or more inorganic compounds for improving the coloring efficiency. Examples of such inorganic compounds include metal oxides such as titanium oxide, magnesium oxide, zinc oxide, aluminum oxide, silicon oxide, nickel oxide, tin oxide, neodymium oxide, mica, zeolite, kaolinite, copper compounds, and molybdenum. System compounds, copper / molybdenum composite oxides, copper / tungsten compounds, metal salts and the like.

As the copper compound, for example, copper oxide, copper halide, formic acid, citric acid, salicylic acid, lauric acid, oxalic acid, organic acid copper such as maleic acid, copper phosphate, and inorganic copper such as copper hydroxyphosphate are preferable. Can be used.

と し て As the molybdenum-based compound, molybdenum, molybdenum dioxide, molybdenum trioxide, molybdenum chloride, and molybdate metal (metals: K, Zn, Ca, Ni, bismuth, Mg, etc.) can be preferably used.

と し て As the metal salt, a salt of an acid such as sulfuric acid, nitric acid, oxalic acid, or carbonic acid and a metal such as barium, cobalt, magnesium, nickel, or iron can be used.

場合 When the adhesive layer 2 contains an inorganic compound, the content of the inorganic compound in the adhesive layer 2 is preferably about 5 to 65% by mass.

接着 The adhesive component contained in the adhesive forming the adhesive layer 2 may be a two-component curing type or a one-component curing type. Also, the bonding mechanism of the bonding component is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a hot-melt type, and a hot-pressure type.

Specific examples of the adhesive component that can be used for forming the adhesive layer 2 include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester; polyethers; polyurethane Epoxy resins; phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefin resins such as polyolefins, acid-modified polyolefins, and metal-modified polyolefins; polyvinyl acetate resins; (Meth) acrylic resin; polyimide; amino resin such as urea resin and melamine resin; silicone resin; rubber or tree such as chloroprene rubber, nitrile rubber, styrene-butadiene rubber; And the like. One of these adhesive components may be used alone, or two or more thereof may be used in combination. Among these adhesive components, polyurethane is preferable.

Although the content of the adhesive component in the adhesive layer 2 is not particularly limited, the base layer 1 with the adhesive layer 2 interposed therebetween despite the fact that the adhesive layer 2 contains a material capable of forming an image. From the viewpoint of exhibiting a high adhesion between the substrate layer 3 and the barrier layer 3 and eliminating the need to increase the output of the laser beam, and suppressing the deterioration of the base layer 1 due to the image formation using the laser beam, the lower limit is set. Is preferably about 50% by weight or more, more preferably about 60% by weight or more, further preferably about 65% by weight or more, further preferably about 70% by weight or more, and still more preferably about 75% by weight or more. Is preferably about 99.9% by mass or less, more preferably about 99% by mass or less, and still more preferably about 98% by mass or less. The preferred ranges are about 50 to 99.9% by mass, 50 to 99% by mass. About 50% to 98% by mass, about 60 to 99.9% by mass, about 60 to 99% by mass, about 60 to 98% by mass, about 65 to 99.9% by mass, about 65 to 99% by mass, About 65 to 98% by mass, about 70 to 99.9% by mass, about 70 to 99% by mass, about 70 to 98% by mass, about 75 to 99.9% by mass, about 75 to 99% by mass, 75 to 98% by mass %. The content of the adhesive component in the adhesive layer 2 may be determined by observing the cross-section of the adhesive layer 2 (for example, by observing a cross-section with a scanning electron microscope, energy dispersive X-ray analysis, or infrared absorption spectroscopy). Analysis method). The content of the material capable of forming an image by irradiating a laser beam in the adhesive layer 2 can be similarly measured by various known analysis methods.

In the packaging material for an electric storage device of the present invention, the adhesive strength between the base material layer 1 and the barrier layer 3 is preferably 3 N / 15 mm or more, more preferably 4 N / 15 mm or more, and further preferably 5 N / 15 mm or more. No. The upper limit of the adhesive strength is, for example, 6 N / 15 mm or less. The method for measuring the adhesive strength is as follows.

(Measurement method of adhesive strength)
A test sample is prepared by cutting out a packaging material for an electricity storage device (not irradiated with laser light) into a size of 100 mm in length and 15 mm in width. Next, using a tensile tester (for example, an autograph manufactured by Shimadzu Corporation), at a tensile speed of 200 mm / min, a peel angle of 180 °, and a distance between chucks of 50 mm, the base layer and the barrier layer of each test sample were tested. The space is peeled in the length direction, and the peel strength (N / 15 mm) is measured. When a test sample of the above size cannot be prepared due to circumstances such as the size of the packaging material for an electricity storage device being small, the size is measured with a measurable size, and the adhesive strength is calculated by converting it to a width of 15 mm.

The thickness of the adhesive layer 2 is high between the base layer 1 and the barrier layer 3 via the adhesive layer 2 even though the adhesive layer 2 includes a material capable of forming an image. The lower limit is preferably about 1 μm or more, from the viewpoint of demonstrating the adhesiveness and increasing the output of the laser light without the necessity of increasing the output of the laser light, and suppressing the deterioration of the base material layer 1 due to the image formation using the laser light. It is preferably about 2 μm or more, and the upper limit is preferably about 10 μm or less, more preferably about 5 μm or less, and the preferred range is about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, About 5 μm.

(Image formation by laser light)
The image formation of the adhesive layer 2 by the laser beam is performed by using a YAG (yttrium (Y), aluminum (A), garnet (G)) laser beam (wavelength = 1.64 μm), a YVO ₄ (yttrium vanadate) laser beam (wavelength). = 1.064 µm), and a fiber laser beam (for example, wavelength = 1090 nm) is preferably used. These lasers have a property of transmitting through a transparent body, and by utilizing the property, generation of smoke and the like at the time of image formation can be suppressed, and color development density and influence on each layer can be adjusted. As a result, even when an image is formed by a laser beam, an extremely clear image without holes or the like can be formed.

In the power storage device packaging material of the present invention or the power storage device of the present invention described later, by irradiating these laser beams from the base material layer 1 side, the deterioration of each layer such as the base material layer can be achieved at a low output. An image can be suitably formed on the adhesive layer 2 while minimizing it.

The pulse condition of the laser beam is, for example, a pulse speed of 300 to 4000 mm / s, more preferably 1500 to 4000 mm / s, using a fiber laser machine (for example, Panasonic LPX-250, manufactured by SUNX Co., Ltd., wavelength 1060 nm). Conditions are used. By performing image formation under these conditions, high-speed image formation is possible and a clear image can be obtained.

The image includes characters, numbers, symbols, designs, barcodes, patterns, logos, and the like, and the shape of the image is not limited to these. In the image forming process using laser light, a clear image, for example, a clear character can be formed even if the average output of the laser is set low or the scan speed is set high.

(4) The diameter of the discoloration area formed by laser beam spot irradiation is desirably about 40 μm to 1 mm, more preferably about 200 to 700 μm. A clear image is obtained in this discolored area. If the diameter of the discoloration area is smaller than this, loss of the image or thinning of the line width occurs, resulting in a lack of visibility. On the other hand, if it is larger than this, the image is undesirably destroyed. The diameter of the dots formed by the laser beam spot irradiation is, for example, about 80 to 500 μm.

[Barrier layer 3]
In the packaging material for an electric storage device, the barrier layer 3 is a layer that suppresses at least ingress of moisture.

Examples of the barrier layer 3 include a metal foil having a barrier property, a vapor-deposited film, and a resin layer. Examples of the deposited film include a metal deposited film, an inorganic oxide deposited film, and a carbon-containing inorganic oxide deposited film, and examples of the resin layer include polyvinylidene chloride. Examples of the barrier layer 3 include a resin film provided with at least one of these deposited films and resin layers. A plurality of barrier layers 3 may be provided. The barrier layer 3 preferably includes a layer made of a metal material. Specific examples of the metal material forming the barrier layer 3 include an aluminum alloy, stainless steel, and titanium steel. When the metal material is used as the metal foil, it may include at least one of an aluminum alloy foil and a stainless steel foil. preferable.

The aluminum alloy foil is more preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy from the viewpoint of improving the formability of the packaging material for an electric storage device, and further improving the formability. Therefore, it is preferable to use an aluminum alloy foil containing iron. In the aluminum alloy foil containing iron (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, and more preferably 0.5 to 2.0% by mass. When the iron content is 0.1% by mass or more, a packaging material for an electric storage device having more excellent moldability can be obtained. When the iron content is 9.0% by mass or less, a packaging material for an electric storage device having more excellent flexibility can be obtained. Examples of the soft aluminum alloy foil include, for example, an aluminum alloy having a composition specified by JIS H4160: 1994 A8021HO, JIS H4160: 1994 A8079HO, JIS H4000: 2014 A8021PO, or JIS H4000: 2014 A8079PO. Foil.

ス テ ン レ ス Examples of the stainless steel foil include austenitic, ferritic, austenitic / ferritic, martensitic, and precipitation hardening stainless steel foils. Further, from the viewpoint of providing a packaging material for an electricity storage device having excellent moldability, the stainless steel foil is preferably made of austenitic stainless steel.

具体 Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L and the like, among which SUS304 is particularly preferred.

In the case of a metal foil, the thickness of the barrier layer 3 may be at least a function as a barrier layer that suppresses intrusion of moisture, and is, for example, about 9 to 200 μm. The thickness of the barrier layer 3 is, for example, preferably about 85 μm or less, more preferably about 50 μm or less, still more preferably about 40 μm or less, particularly preferably about 35 μm or less, and the lower limit is preferably about 10 μm or more, more preferably about 20 μm or more, and more preferably about 25 μm or more. A preferable range of the thickness is about 10 to 85 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 35 μm, or about 20 to About 85 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 35 μm, about 25 to 85 μm, about 25 to 50 μm, about 25 to 40 μm, about 25 to 35 μm. When the barrier layer 3 is made of an aluminum alloy foil, the above range is particularly preferable. In particular, when the barrier layer 3 is made of stainless steel foil, the upper limit of the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, and still more preferably about 40 μm or less. More preferably, the thickness is about 30 μm or less, particularly preferably about 25 μm or less, and the lower limit is preferably about 10 μm or more, more preferably about 15 μm or more, and the preferred thickness range is about 10 to 60 μm. About 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

In the case where the barrier layer 3 is a metal foil, it is preferable to provide a corrosion-resistant coating on at least the surface opposite to the base material layer in order to prevent dissolution and corrosion. The barrier layer 3 may have a corrosion resistant film on both sides. Here, the corrosion-resistant coating is, for example, a hot-water conversion treatment such as a boehmite treatment, a chemical conversion treatment, an anodic oxidation treatment, and a corrosion prevention treatment of applying a coating agent on the surface of the barrier layer. Refers to a thin film having properties (eg, acid resistance, alkali resistance, etc.). The corrosion-resistant coating specifically means a coating that improves the acid resistance of the barrier layer (acid-resistant coating), a coating that improves the alkali resistance of the barrier layer (alkali-resistant coating), and the like. As the treatment for forming the corrosion resistant film, one kind may be performed, or two or more kinds may be combined. Among these treatments, the hydrothermal alteration treatment and the anodic oxidation treatment are treatments in which the surface of the metal foil is dissolved by a treating agent to form a metal compound having excellent corrosion resistance. Note that these processes may be included in the definition of the chemical conversion process. When the barrier layer 3 has a corrosion-resistant film, the barrier layer 3 includes the corrosion-resistant film.

As the corrosion-resistant film formed by the chemical conversion treatment, various types are known, and at least one of a phosphate, a chromate, a fluoride, a triazine thiol compound, and a rare earth oxide is mainly used. And a corrosion-resistant film containing. As the rare earth oxide, a cerium compound is preferable, and among them, cerium oxide is preferable. Examples of the chemical conversion treatment using phosphate or chromate include chromate chromate treatment, phosphoric acid chromate treatment, phosphoric acid-chromate treatment, chromate treatment, and the like. Examples of the compound include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, acetyl chromate, chromium chloride, potassium chromium sulfate, and the like. Examples of the phosphorus compound used for these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid. Examples of the chromate treatment include an etching chromate treatment, an electrolytic chromate treatment, and a coating type chromate treatment, and a coating type chromate treatment is preferable. In this coating type chromate treatment, at least the inner layer side of a barrier layer (for example, an aluminum alloy foil) is first exposed to a known method such as an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, and an acid activation method. A degreasing treatment is performed by a treatment method, and then a phosphate metal such as a Cr (chromium) salt, a Ti (titanium) phosphate, a Zr (zirconium) phosphate, or a Zn (zinc) salt is formed on the degreasing surface. A treatment liquid (aqueous solution) mainly containing a salt and a mixture of these metal salts, or a treatment liquid (aqueous solution) mainly containing a non-metallic phosphate and a mixture of these non-metal salts, or This is a process of applying a treatment liquid (aqueous solution) composed of a mixture of the resin and a synthetic resin or the like by a known coating method such as a roll coating method, a gravure printing method, or a dipping method, and drying. Examples of the resin component used at this time include water-soluble polymers such as phenol and polyacrylic acid. An aminated phenol polymer having a repeating unit represented by the following general formulas (1) to (4) is used. Chromate treatment. In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. Is also good.

In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ¹ and R ² are the same or different and each represents a hydroxy group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, A straight-chain or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group is exemplified. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, A straight or branched chain having 1 to 4 carbon atoms, in which one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group and 4-hydroxybutyl group is substituted And an alkyl group. In the general formulas (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxy group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulas (1) to (4) is preferably, for example, about 500 to 1,000,000, and is preferably about 1,000 to 20,000. More preferred. The aminated phenol polymer is produced, for example, by subjecting a phenol compound or a naphthol compound to formaldehyde to polycondensation to produce a polymer comprising a repeating unit represented by the above general formula (I) or (III), And an amine (R ¹ R ² NH) to introduce a water-soluble functional group (—CH ₂ NR ¹ R ² ) into the polymer obtained above. The aminated phenolic polymer is used alone or in combination of two or more.

The corrosion-resistant film prevents delamination between a barrier layer (for example, an aluminum alloy foil) and a base material layer during molding of a packaging material for an electricity storage device, and is formed by hydrogen fluoride generated by a reaction between an electrolyte and moisture. , Dissolution and corrosion of the barrier layer surface, especially when the barrier layer is an aluminum alloy foil, to prevent aluminum oxide present on the barrier layer surface from dissolving and corroding, and adhesion (wetting) of the barrier layer surface And the effect of preventing delamination between the base layer and the barrier layer during heat sealing and preventing delamination between the base layer and the barrier layer during molding.

Another example of the corrosion resistant film is formed by a coating type corrosion prevention treatment in which a coating agent containing at least one selected from the group consisting of a rare earth oxide sol, an anionic polymer and a cationic polymer is applied. Thin film to be formed. The coating agent may further contain a phosphoric acid or a phosphate, and a crosslinking agent for crosslinking the polymer. In the rare earth oxide sol, fine particles of the rare earth oxide (for example, particles having an average particle diameter of 100 nm or less) are dispersed in a liquid dispersion medium. Examples of the rare earth element oxide include cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide. Cerium oxide is preferable from the viewpoint of further improving the adhesion. The rare earth element oxides contained in the corrosion resistant film can be used alone or in combination of two or more. As the liquid dispersion medium of the rare earth element oxide sol, for example, various solvents such as water, an alcohol solvent, a hydrocarbon solvent, a ketone solvent, an ester solvent, and an ether solvent can be used, and water is preferable. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin in which a primary amine is graft-polymerized on an acrylic main skeleton, polyallylamine or a derivative thereof. And aminated phenols are preferred. The anionic polymer is preferably a poly (meth) acrylic acid or a salt thereof, or a copolymer containing (meth) acrylic acid or a salt thereof as a main component. Further, it is preferable that the crosslinking agent is at least one selected from the group consisting of a compound having any functional group of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent. Further, the phosphoric acid or phosphate is preferably condensed phosphoric acid or condensed phosphate.

As an example of the corrosion-resistant film, a dispersion of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide or fine particles of barium sulfate in phosphoric acid is applied to the surface of the barrier layer. Those formed by performing a baking treatment at a temperature of not less than ° C.

(4) The corrosion-resistant film may have a laminated structure in which at least one of a cationic polymer and an anionic polymer is further laminated, if necessary. Examples of the cationic polymer and the anionic polymer include those described above.

組成 The analysis of the composition of the corrosion-resistant coating can be performed, for example, using a time-of-flight secondary ion mass spectrometry.

The amount of the corrosion-resistant film formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited. For example, in the case of performing a coating type chromate treatment, a chromic acid compound per 1 m ² of the surface of the barrier layer 3 is used. Is, for example, about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of chromium, the phosphorus compound is, for example, about 0.5 to 50 mg, preferably about 1.0 to 40 mg, in terms of phosphorus, and an aminated phenol polymer Is desirably contained at a ratio of, for example, about 1.0 to 200 mg, preferably about 5.0 to 150 mg.

The thickness of the corrosion-resistant coating is not particularly limited, but is preferably about 1 nm to 20 μm, more preferably 1 nm to 100 nm, from the viewpoint of the cohesion of the coating and the adhesion to the barrier layer and the heat-fusible resin layer. And more preferably about 1 nm to 50 nm. The thickness of the corrosion resistant film can be measured by observation with a transmission electron microscope or a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy. The time-of-flight secondary ion mass spectrometry analysis of the composition of the corrosion resistant coating using, for example, secondary ion consisting Ce and P and O ^{_{(e.g., Ce 2 PO 4 +, CePO}} 4 - at least 1, such as species) or, for example, secondary ion of Cr and P and O (e.g., CrPO ₂ ^+, CrPO ₄ ^- peak derived from at least one), such as is detected.

The chemical conversion treatment involves applying a solution containing a compound used for forming a corrosion-resistant film to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, an immersion method, and the like. By heating to about 70 to 200 ° C. Before the chemical conversion treatment is performed on the barrier layer, the barrier layer may be subjected to a degreasing treatment by an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like in advance. By performing the degreasing treatment in this manner, it is possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer. In addition, by using an acid degreaser obtained by dissolving a fluorine-containing compound with an inorganic acid for the degreasing treatment, it is possible to form not only the degreasing effect of the metal foil but also a passivated metal fluoride. In such a case, only the degreasing treatment may be performed.

[Heat-fusible resin layer 4]
In the packaging material for an electricity storage device of the present invention, the heat-fusible resin layer 4 corresponds to the innermost layer, and the heat-fusible resin layers are heat-sealed with each other during assembly of the electricity storage device to seal the electricity storage device element. It is.

The resin component used in the heat-fusible resin layer 4 is not particularly limited as long as it is heat-fusible, and examples thereof include polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin. That is, the resin constituting the heat-fusible resin layer 4 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy or gas chromatography / mass spectrometry, and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), and polypropylene. Polypropylene (eg, a random copolymer of propylene and ethylene); a terpolymer of ethylene-butene-propylene; and the like. Among these polyolefins, polyethylene and polypropylene are preferred.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer. Examples of the olefin constituting the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, isoprene, and the like. Is mentioned. Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include a cyclic alkene such as norbornene; specifically, a cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, a cyclic alkene is preferable, and norbornene is more preferable.

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

The acid-modified cyclic polyolefin is obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin in place of α, β-unsaturated carboxylic acid or its anhydride, or by adding α, β- to the cyclic polyolefin. It is a polymer obtained by subjecting an unsaturated carboxylic acid or its anhydride to block polymerization or graft polymerization. The cyclic polyolefin to be acid-modified is the same as described above. The acid component used for modification is the same as that used for modifying the polyolefin.

中 で も Among these resin components, preferred are acid-modified polyolefins; more preferred are acid-modified polypropylene.

(4) The heat-fusible resin layer 4 may be formed of one type of resin component alone, or may be formed of a blend polymer in which two or more types of resin components are combined. Further, the heat-fusible resin layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resin components.

In the present invention, a lubricant is preferably present on the surface of the heat-fusible resin layer 4 from the viewpoint of enhancing the moldability of the packaging material for an electric storage device. Since the lubricant is present on the surface of the heat-fusible resin layer 4 and the lubricant layer is formed, curl due to molding of the power storage device packaging material is suppressed, and the formability of the power storage device packaging material is improved. Can be. The lubricant is not particularly limited, and a known lubricant can be used. A lubricant may be used alone or in combination of two or more.

The lubricant is not particularly limited, but preferably includes an amide lubricant. Specific examples of the lubricant include saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylolamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide and the like. Specific examples of the saturated fatty acid amide include lauric amide, palmitic amide, stearic amide, behenic amide, and hydroxystearic amide. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitic amide, N-stearyl stearamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide, and the like. Specific examples of methylolamide include methylol stearamide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearin Acid amide, hexamethylenebisbehenamide, hexamethylenehydroxystearic acid amide, N, N'-distearyladipamide, N, N'-distearylsebacic amide and the like. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bis oleic acid amide, N, N'-dioleyl adipamide, N, N'-dioleyl sebacic amide And the like. Specific examples of the fatty acid ester amide include stearoamidoethyl stearate. Specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N, N'-distearylisophthalic acid amide, and the like. One type of lubricant may be used alone, or two or more types may be used in combination.

The amount of the lubricant present on the surface of the heat-fusible resin layer 4 is not particularly limited. From the viewpoint of improving the moldability of the packaging material for an electric storage device, it is preferably 10 in an environment at a temperature of 24 ° C. and a relative humidity of 60%. About 50 mg / m ² , more preferably about 15 to 40 mg / m ² .

The heat-fusible resin layer 4 may contain a lubricant. In addition, the lubricant present on the surface of the heat-fusible resin layer 4 may be formed by exuding the lubricant contained in the resin constituting the heat-fusible resin layer 4, or may be formed by leaching the heat-fusible resin layer. The surface of No. 4 may be coated with a lubricant.

Further, the thickness of the heat-fusible resin layer 4 can be set according to the presence or absence of the adhesive layer 5, the thickness of the adhesive layer 5, and the like. Although not limited, the upper limit is, for example, about 100 μm or less, preferably about 85 μm or less, more preferably 60 μm or less, and the lower limit is, for example, about 15 μm or more, preferably 20 μm or more. About 15 to 100 μm, about 15 to 85 μm, about 15 to 60 μm, about 20 to 100 μm, about 20 to 85 μm, about 20 to 60 μm. In particular, for example, when the thickness of an adhesive layer 5 described later is 10 μm or more, the upper limit of the thickness of the heat-fusible resin layer 4 is preferably about 85 μm or less, more preferably about 60 μm or less. The lower limit is, for example, about 15 μm or more, preferably 20 μm or more, and the preferable range is about 15 to 85 μm, about 15 to 60 μm, about 20 to 85 μm, or about 20 to 60 μm. Further, for example, when the thickness of an adhesive layer 5 described below is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-fusible resin layer 4 is preferably about 20 μm or more, more preferably About 35 to 85 μm.

[Adhesive layer 5]
In the packaging material for an electric storage device of the present invention, the adhesive layer 5 is a layer provided as necessary between the barrier layer 3 and the heat-fusible resin layer 4 in order to firmly adhere them.

The adhesive layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4. As the resin used for forming the adhesive layer 5, polyolefin resins such as the polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin exemplified in the heat-fusible resin layer 4 described above can be suitably used. As the polyolefin resin, polypropylene resins such as polypropylene, cyclic polypropylene, acid-modified polypropylene, and acid-modified cyclic polypropylene can be preferably used. In this case, the heat-fusible resin layer 4 and the adhesive layer 5 can be suitably formed by extrusion.

樹脂 Further, as the resin used for forming the adhesive layer 5, the same resin as the adhesive exemplified in the adhesive layer 2 can be used.

From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, the polyolefin resin is preferably a polyolefin or an acid-modified polyolefin, and particularly preferably a polypropylene or an acid-modified polypropylene. That is, the resin constituting the adhesive layer 5 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy or gas chromatography / mass spectrometry, and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

接着 From the viewpoint of improving the adhesion between the barrier layer 3 (or the corrosion-resistant film) and the heat-fusible resin layer 4, the adhesive layer 5 preferably contains an acid-modified polyolefin. The acid-modified polyolefin is a polymer obtained by modifying a polyolefin by block polymerization or graft polymerization with an acid component such as carboxylic acid. Examples of the acid component used for the modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, and anhydrides thereof. Examples of the polyolefin to be modified include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), and polypropylenes. Polypropylene such as a random copolymer (for example, a random copolymer of propylene and ethylene); and a terpolymer of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferred.

In the adhesive layer 5, among the acid-modified polyolefins, a maleic anhydride-modified polyolefin, particularly, a maleic anhydride-modified polypropylene is preferable.

Further, from the viewpoint of reducing the thickness of the packaging material for an electrical storage device and making the packaging material for an electrical storage device excellent in shape stability after molding, the adhesive layer 5 is a resin composition containing an acid-modified polyolefin and a curing agent. More preferably, the cured product is Preferred examples of the acid-modified polyolefin include those described above.

The adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. Preferably, the cured product is a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group and a compound having an epoxy group. Further, the adhesive layer 5 preferably includes at least one selected from the group consisting of a urethane resin, an ester resin, and an epoxy resin, and more preferably includes a urethane resin and an epoxy resin. As the ester resin, for example, an amide ester resin is preferable. The amide ester resin is generally formed by a reaction between a carboxyl group and an oxazoline group. The adhesive layer 5 is more preferably a cured product of a resin composition containing at least one of these resins and the acid-modified polyolefin. In the case where an unreacted product of a compound having an isocyanate group, a compound having an oxazoline group, and a curing agent such as an epoxy resin remains in the adhesive layer 5, the presence of the unreacted product is determined by, for example, infrared spectroscopy. It can be confirmed by a method selected from Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

Further, from the viewpoint of further improving the adhesion between the barrier layer 3 (or the corrosion-resistant film), the heat-fusible resin layer 4 and the adhesive layer 5, the adhesive layer 5 includes an oxygen atom, a heterocyclic ring, a C = N bond, And a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of C—O—C bonds. Examples of the curing agent having a heterocyclic ring include a curing agent having an oxazoline group and a curing agent having an epoxy group. Examples of the curing agent having a C ＝ N bond include a curing agent having an oxazoline group and a curing agent having an isocyanate group. Examples of the curing agent having a C—O—C bond include a curing agent having an oxazoline group, a curing agent having an epoxy group, and a urethane resin. The fact that the adhesive layer 5 is a cured product of the resin composition containing these curing agents may be determined, for example, by gas chromatography mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF) SIMS) and X-ray photoelectron spectroscopy (XPS).

化合物 The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively increasing the adhesion between the barrier layer 3 (or the corrosion resistant film) and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate-based curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), And a mixture thereof, a copolymer with another polymer, and the like.

The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. More preferably, it is within the range.

The compound having an oxazoline group is not particularly limited as long as it has a oxazoline skeleton. Specific examples of the compound having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Examples of commercially available products include Epocross series manufactured by Nippon Shokubai Co., Ltd.

The proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. Thereby, the adhesion between the barrier layer 3 (or the corrosion resistant film) and the adhesive layer 5 can be effectively increased.

The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by an epoxy group present in the molecule, and a known epoxy resin can be used. The weight average molecular weight of the epoxy resin is preferably about 50 to 2,000, more preferably about 100 to 1,000, and further preferably about 200 to 800. In the present invention, the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC) under the condition using polystyrene as a standard sample.

Specific examples of the epoxy resin include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether. One type of epoxy resin may be used alone, or two or more types may be used in combination.

The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferred. Thereby, the adhesion between the barrier layer 3 (or the corrosion resistant film) and the adhesive layer 5 can be effectively increased.

In the present invention, the adhesive layer 5 is a resin composition containing at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and an epoxy resin, and the acid-modified polyolefin. In the case of a product, the acid-modified polyolefin functions as a main agent, and the compound having an isocyanate group, the compound having an oxazoline group, and the epoxy resin each function as a curing agent.

The thickness of the adhesive layer 5 is preferably about 30 μm or less, more preferably about 20 μm or less, more preferably about 5 μm or less, and the lower limit is about 0.1 μm or more, about 0.5 μm or more, The thickness is preferably about 0.1 to 30 μm, about 0.1 to 20 μm, about 0.1 to 5 μm, about 0.5 to 30 μm, about 0.5 to 20 μm, and about 0.5 to about 20 μm. About 5 μm.

The carbodiimide-based curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N = C = N-). As the carbodiimide-based curing agent, a polycarbodiimide compound having at least two or more carbodiimide groups is preferable.

硬化 From the viewpoint of enhancing the adhesion between the barrier layer 3 and the heat-fusible resin layer 4 by the adhesive layer 5, the curing agent may be composed of two or more compounds.

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of about 0.1 to 50% by mass, more preferably in the range of about 0.1 to 30% by mass. More preferably, it is in the range of about 0.1 to 10% by mass.

Furthermore, the adhesive layer 5 can be suitably formed using, for example, an adhesive. Examples of the adhesive include a non-crystalline polyolefin resin (A) having a carboxyl group, a polyfunctional isocyanate compound (B), and a tertiary amine having no functional group that reacts with the polyfunctional isocyanate compound (B) ( C) and the polyfunctional isocyanate compound (B) in an amount of 0.3 to 10 mol based on 1 mol of the carboxyl group, based on 1 mol of the carboxyl group. And those formed from an adhesive composition containing the tertiary amine (C) in a range of 1 to 10 mol. The adhesive contains a styrene-based thermoplastic elastomer (A), a tackifier (B), and a polyisocyanate (C), and contains a styrene-based thermoplastic elastomer (A) and a tackifier (B). ), The styrene-based thermoplastic elastomer (A) is contained in an amount of 20 to 90% by weight, and the tackifier (B) is contained in an amount of 10 to 80% by weight in 100% by weight of the styrene-based thermoplastic elastomer (A). Having an active hydrogen derived from an amino group or a hydroxyl group of 0.003 to 0.04 mmol / g, and the tackifier (B) based on 1 mol of the active hydrogen derived from the styrene thermoplastic elastomer (A). The active hydrogen derived from the functional group is 0 to 15 mol, and the polyisocyanate (C) is composed of the active hydrogen derived from the styrene-based thermoplastic elastomer (A) and the active hydrogen derived from the tackifier (B). The total one mole of the sexual hydrogen, may also be mentioned such as those isocyanate groups is formed by three-adhesive composition consisting of those that are included in a range of 150 mol.

About the thickness of the adhesive layer 5, about a lower limit, Preferably about 2 micrometers or more, about 10 micrometers or more, about 13 micrometers or more, about 15 micrometers or more, about 20 micrometers or more are mentioned, About an upper limit, about 50 micrometers or less, about 45 micrometers or less. The preferred range is about 2 to 50 μm, about 10 to 50 μm, about 13 to 50 μm, about 15 to 50 μm, about 20 to 50 μm, about 2 to 45 μm, about 10 to 45 μm, about 13 to 45 μm, about 15 to 45 μm. About 45 μm, and about 20 to 45 μm. As the adhesive layer 5, it is preferable to use a polyolefin resin such as the polyolefin resin exemplified in the heat-fusible resin layer 4 and the acid-modified polyolefin resin. In this case, the lower limit of the thickness of the adhesive layer is about The thickness is preferably 10 μm or more and about 20 μm or more, and the upper limit is particularly preferably about 50 μm or less. Also, the adhesive exemplified for the adhesive layer 2 can be used. In this case, the thickness of the adhesive layer is preferably about 2 to 10 μm and about 2 to 5 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, and still more preferably about 0.5 to 5 μm. In the case of an adhesive layer formed from the above-mentioned adhesive composition, the thickness after drying and curing is about 1 to 30 g / m ² . When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like.

[Surface coating layer 6]
In the packaging material for an electricity storage device of the present invention, if necessary, the base material layer 1 (the barrier layer of the base material layer 1) may be provided for the purpose of improving design, electrolytic solution resistance, abrasion resistance, and moldability. On the side opposite to the layer 3), a surface coating layer 6 may be provided as necessary. The surface coating layer 6 is the outermost layer when the electric storage device is assembled.

The surface coating layer 6 can be formed of, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, or the like. Among these, the surface coating layer 6 is preferably formed of a two-component curable resin. Examples of the two-component curable resin forming the surface coating layer 6 include a two-component curable urethane resin, a two-component curable polyester resin, and a two-component curable epoxy resin. The surface coating layer 6 may contain an additive. The additive to be added may function, for example, as a matting agent, and the surface coating layer may function as a mat layer. For example, when the surface coating layer is a mat layer, it is difficult to form an image on the surface of the surface coating layer by printing using a conventional inkjet printing machine or the like. An image is formed by the irradiation of light, so that a clear image can be formed.

Examples of the additive include fine particles having a particle size of 0.5 nm to 5 μm. The material of the additive is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, and organic substances. Also, the shape of the additive is not particularly limited, and examples thereof include a sphere, a fiber, a plate, an irregular shape, and a balloon. As an additive, specifically, talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high Melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel and the like can be mentioned. These additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate and titanium oxide are preferable from the viewpoint of dispersion stability and cost. In addition, various surface treatments such as an insulation treatment and a high dispersibility treatment may be applied to the surface of the additive.

The method for forming the surface coating layer 6 is not particularly limited, and includes, for example, a method of applying a two-component curable resin for forming the surface coating layer 6 to one surface of the base material layer 1. In the case of adding an additive, the additive may be added to the two-component curable resin, mixed, and then applied.

When the surface coating layer 6 is provided, from the viewpoint of suitably irradiating the adhesive layer 2 of the power storage device packaging material 10 with laser light, the surface coating layer 6 is transparent or translucent enough to transmit the laser light. It is preferred that In addition, the transparent and translucent include colored transparent and colored translucent.

厚 み The thickness of the surface coating layer 6 is not particularly limited as long as the above-mentioned function as the surface coating layer 6 is exhibited, and is, for example, about 0.5 to 10 μm, preferably about 1 to 5 μm.

3. Manufacturing method of packaging material for power storage device In the manufacturing method of packaging material for power storage device of the present invention, at least the base layer 1, the adhesive layer 2, the barrier layer 3, and the heat-fusible resin layer 4 are in this order. Is provided. As described above, the adhesive layer 2 is laminated so as to be in contact with the barrier layer 3. Further, the adhesive layer 2 includes a material capable of forming an image by irradiating a laser beam. The details of the base material layer 1, the adhesive layer 2, the barrier layer 3, and the heat-fusible resin layer 4 are as described above. In the method for manufacturing a packaging material for an electric storage device of the present invention, the above-described adhesive layer 5 and surface coating layer 6 can be laminated as necessary.

Further, in the method for producing a packaging material for an electric storage device of the present invention, the adhesive layer 2 is irradiated with laser light from the base material layer 1 side of the electric storage device packaging material to form an image on the adhesive layer 2. You may. Specifically, for example, a base material layer 1, an adhesive layer 2, a barrier layer 3, an adhesive layer 5 provided as needed, and a heat-fusible resin layer 4 are laminated to produce a packaging material for an electricity storage device. By irradiating the adhesive layer 2 with laser light from the base layer 1 side of the obtained packaging material for an electric storage device, an image can be formed on the adhesive layer 2. Further, a laminate of the base material layer 1, the adhesive layer 2, and the barrier layer 3 is formed, and the adhesive layer 2 is irradiated with laser light from the base material layer 1 side of the laminate, and After forming an image, the adhesive layer 5 and the heat-fusible resin layer 4 provided as necessary may be laminated on the barrier layer 3 of the laminate to manufacture a packaging material for an electric storage device. Details of the laser light used for image formation and the irradiation conditions are as described above.

例 An example of the method for manufacturing the packaging material for an electricity storage device of the present invention is as follows. First, a laminate in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are sequentially laminated (hereinafter, sometimes referred to as “laminate A”) is formed. Specifically, the laminate A is formed by applying the adhesive used for forming the adhesive layer 2 to the base material layer 1 or the barrier layer 3 whose surface is subjected to a chemical conversion treatment, if necessary, by a gravure coating method or a roll method. After coating and drying by a coating method such as a coating method, the coating can be performed by a dry lamination method in which the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured.

Next, the adhesive layer 5 and the heat-fusible resin layer 4 are laminated on the barrier layer 3 of the laminate A in this order. For example, (1) a method in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated by co-extrusion on the barrier layer 3 of the laminate A (co-extrusion laminating method); A laminate formed by laminating the heat-fusible resin layer 4 and the heat-fusible resin layer 4 and laminating the laminate on the barrier layer 3 of the laminate A by a thermal laminating method; (3) bonding the laminate on the barrier layer 3 of the laminate A An adhesive for forming the layer 5 is laminated by an extrusion method or a solution coating method, dried at a high temperature, or baked at a high temperature, and the heat-fusible resin layer 4 previously formed into a sheet is formed on the adhesive layer 5. A method of laminating by a thermal lamination method, (4) bonding while laminating the melted adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-fusible resin layer 4 formed in a sheet shape in advance. The laminate A and the heat-fusible resin layer 4 are Ri fit method (sandwich lamination method).

When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base material layer 1 on the side opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above-described resin forming the surface coating layer 6 to the surface of the base material layer 1. The order of the step of laminating the barrier layer 3 on the surface of the substrate layer 1 and the step of laminating the surface coating layer 6 on the surface of the substrate layer 1 are not particularly limited. For example, after forming the surface coating layer 6 on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer 6.

As described above, surface coating layer 6 / base layer 1 / adhesive layer 2 / barrier layer 3 whose surface has been subjected to chemical conversion treatment if necessary / adhesive layer 5 / heat-fusible resin provided as required A laminate composed of the layer 4 is formed. In order to strengthen the adhesiveness of the adhesive layer 2 or the adhesive layer 5, further heating such as a hot roll contact type, a hot air type, a near infrared type or a far infrared type is performed. It may be subjected to processing. The conditions of such a heat treatment include, for example, a temperature of 150 to 250 ° C. for 1 minute to 5 minutes.

In the packaging material for an electric storage device of the present invention, each layer constituting the laminate improves or stabilizes film forming properties, lamination processing, and suitability for secondary processing of final products (pouching, embossing) as required. For this purpose, a surface activation treatment such as a corona treatment, a blast treatment, an oxidation treatment, and an ozone treatment may be performed.

4. Use of packaging material for power storage device and power storage device The packaging material for power storage device of the present invention is used for a package for hermetically containing a power storage device element such as a positive electrode, a negative electrode, and an electrolyte. That is, a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the power storage device packaging material of the present invention, and can be a power storage device of the present invention. In the packaging material for a power storage device of the present invention, an image may be formed on the adhesive layer 2 or an image may not be formed. With respect to the packaging material for a power storage device of the present invention in which an image is not formed on the adhesive layer 2, an image can be formed on the adhesive layer 2 after the power storage device containing the power storage device element is formed. For this reason, the packaging material for an electric storage device of the present invention in which an image is not formed on the adhesive layer 2 becomes an image forming body of the electric storage device.

Specifically, at least a positive electrode, a negative electrode, and a power storage device element provided with an electrolyte, with the power storage device packaging material of the present invention, in a state of protruding outside metal terminals connected to each of the positive electrode and the negative electrode. In order to form a flange portion (a region where the heat-fusible resin layers are in contact with each other) around the periphery of the power storage device element, the heat-sealable resin layers of the flange portion are sealed by heat-sealing. Thus, an electricity storage device using the electricity storage device packaging material is provided. When the power storage device element is accommodated in a package formed of the power storage device packaging material of the present invention, the heat-fusible resin portion of the power storage device packaging material of the present invention is located inside (the surface in contact with the power storage device element). ) To form a package.

The method for manufacturing a power storage device of the present invention includes: a housing step of housing a power storage device element having at least a positive electrode, a negative electrode, and an electrolyte in a package made of a power storage device packaging material; and any one of before and after the housing step. On the other hand, a step of irradiating the adhesive layer 2 with a laser beam to form an image may be provided. Thereby, an electricity storage device having an image formed on the adhesive layer 2 is obtained. Details of the laser beam used for image formation are as described above.

包装 The packaging material for an electricity storage device of the present invention may be used for any of a primary battery and a secondary battery. The type of the secondary battery is not particularly limited. For example, a lithium ion battery, a lithium ion polymer battery, an all solid state battery, a lead storage battery, a nickel hydrogen storage battery, a nickel cadmium storage battery, a nickel iron storage battery, and a nickel zinc storage battery , Silver oxide / zinc storage batteries, metal-air batteries, polyvalent cation batteries, capacitors, capacitors and the like. Among these secondary batteries, suitable applications of the packaging material for an electricity storage device of the present invention include lithium ion batteries, lithium ion polymer batteries, and all solid state batteries. That is, in the lithium ion battery and the lithium ion polymer battery, as in the case of the power storage device packaging material of the present invention, a packaging material having a laminated structure in which a base material layer, a barrier layer, a heat-fusible resin layer, and the like are laminated is preferable. The packaging material for an electric storage device of the present invention can also be suitably used for these batteries. In particular, in the case of an all-solid battery, friction occurs on the surface of the outer layer during expansion and contraction and pressure restraint, and is easily peeled off by conventional printing. Therefore, the packaging material for an electric storage device of the present invention can be suitably used.

The present invention will be described in detail below with reference to Examples and Comparative Examples. However, the present invention is not limited to the embodiments.

(Example 1-10 and Comparative Example 1-2)
<Manufacture of packaging materials for power storage devices>
A biaxially stretched nylon film (15 μm in thickness, light transmittance at 1067 nm of 80% or more) as a base layer and an aluminum alloy foil (35 μm in thickness) as a barrier layer were prepared. In addition, a resin composition having a composition shown in Table 1 was prepared as a resin composition for forming an adhesive layer for bonding them. A two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was used as the resin composition, and a bismuth-based compound (bismuth oxide) and carbon black were used as materials capable of forming an image by laser light irradiation. A resin composition for forming an adhesive layer (thickness: 3 μm) is applied to one surface of the barrier layer by a dry lamination method, and a base layer is laminated on the resin composition by a dry lamination method. By performing an aging treatment, a laminate of the base material layer / adhesive layer / barrier layer was produced. Incidentally, a chemical conversion treatment was applied to both surfaces of the aluminum alloy foil. The chemical conversion treatment of the aluminum alloy foil is performed by a roll coating method using a treatment solution comprising a phenol resin, a chromium fluoride compound, and phosphoric acid so that the applied amount of chromium is 10 mg / m ² (dry mass). And baking. Next, on the barrier layer of the laminate, a maleic anhydride-modified polypropylene (disposed on the barrier layer side, thickness: 15 μm) as an adhesive layer, and a random polypropylene (disposed on the innermost layer side) as a heat-fusible resin layer, By laminating (thickness: 20 μm), the adhesive layer and the heat-fusible resin layer are respectively laminated on the barrier layer, and the base layer / adhesive layer / barrier layer / adhesive layer / heat-fusible resin layer is formed. A packaging material for a power storage device laminated in order was obtained.

(Image formation by laser beam irradiation)
The adhesive layer is irradiated with laser light from the base layer side of each of the above-mentioned packaging materials for an electric storage device so that the laser beam has the optimum output (W (2000 mmsec)) in Table 1. As a laser light irradiation device, a fiber laser machine (LP-Z250, manufactured by Panasonic Device SUNX Co., Ltd., wavelength 1060 nm) was used, scan speed 2000 mm / sec, pulse period 40 μs, character size length 1 An image was formed under the following conditions: 0.5 mm, 1.5 mm in width, 1.1 mm in character width, 0.3 mm in character line width, and character content "BEFMOQRWXUVYI1346890 +-".

(Image formation evaluation)
For each of the power storage device packaging materials on which the “image formation by laser beam irradiation” was performed, the power storage device packaging material was visually observed from the base layer side, and the image formation evaluation was performed according to the following criteria. Table 1 shows the results.
A: All characters can be decoded B: Some characters can be decoded C: All characters cannot be decoded

(Evaluation of deterioration of base material layer due to laser beam irradiation)
For each of the power storage device packaging materials on which the “image formation by laser beam irradiation” has been performed, a cross section in the thickness direction of a portion where an image is formed is obtained (the cross section is the entire power storage device packaging material). (Obtained by cutting in the thickness direction), the cross section of the base layer (the position where the BEF of the character content is formed) is observed with a laser microscope (magnification: 1000 to 5000 times), and the base layer is deteriorated. Was evaluated according to the following criteria. Table 1 shows the results.
A: No crack in base material in cross-section observation B: 1 to 3 cracks in base material in cross-section observation C: 4 or more cracks in base material in cross-section observation

(Peel strength between base layer and barrier layer)
A test sample was prepared by cutting each of the packaging materials for the storage device (not irradiated with laser light) obtained by the above-mentioned “Production of packaging material for storage device” into a size of 100 mm in length and 15 mm in width. Next, using a tensile tester (Autograph manufactured by Shimadzu Corporation), the distance between the base material layer and the barrier layer of each test sample was set at a tensile speed of 200 mm / min, a peel angle of 180 °, and a distance between chucks of 50 mm. Peeling was performed in the length direction, and peel strength (N / 15 mm) was measured. Table 1 shows the results.

The peel strength (N / 15 mm) of the packaging material for an electric storage device manufactured in the same manner as in Example 2 except that the chemical conversion treatment was not performed on both surfaces of the aluminum alloy foil was measured. .92 N / 15 mm. From this result, it can be seen that by subjecting the surface of the aluminum alloy foil to the chemical conversion treatment, the peel strength between the base material layer and the barrier layer is further improved.

The packaging materials for power storage devices of Examples 1 to 10 are each composed of a laminate having a base layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer in this order, and the adhesive layer is formed of a barrier layer and The adhesive layer includes a material that can form an image by irradiation with a laser beam. In the packaging materials for power storage devices of Examples 1 to 10, although a layer containing a material capable of forming an image is provided between the base material layer and the barrier layer, laser light is applied to the adhesive layer. Image formation by laser irradiation (the minimum output of laser light capable of appropriately forming an image is not too large), so that a high adhesion between the base layer and the barrier layer is provided, and the laser light irradiation It can be seen that the deterioration of the base material layer 1 due to the above is suppressed. On the other hand, in the packaging material for the electricity storage device of Comparative Example 1, the adhesive layer does not include a material that enables image formation by irradiation with laser light, and the minimum output of laser light capable of appropriately forming an image is too large. However, although an image was formed, the substrate layer was significantly deteriorated. In the power storage device packaging material of Comparative Example 2, the output was half of the minimum output of Comparative Example 1, so that the deterioration of the base material layer was suppressed, but an appropriate image could not be formed.

FIG. 4 shows an SEM image (section irradiated with laser) of a cross section of a base layer (biaxially stretched iron film) / adhesive layer / barrier layer (aluminum alloy foil) in the packaging material for an electric storage device of Example 1. 2 shows an image obtained by observing a cross section with a scanning electron microscope. In the SEM image shown in FIG. 4, the upper white layer is an aluminum foil, the thin black layer immediately below is an adhesive layer, and the layer immediately below is a biaxially stretched nylon film. It can be seen that carbon black sublimes at the portion of the adhesive layer irradiated with the laser beam, whereby the interlayer is raised.

(Comparative Example 3)
On a surface of one side of a biaxially stretched nylon film (thickness: 15 μm) as a base material layer, an ink obtained by adding 50% by mass of bismuth oxide to a urethane-based binder resin is applied in a thickness of 0.2 μm to form a printing layer. Was formed. An aluminum alloy foil (thickness: 35 μm) was prepared as a barrier layer. In addition, a resin composition having a urethane-based resin was prepared as a resin composition for forming an adhesive layer for bonding them. A resin composition for forming an adhesive layer (thickness: 3 μm) is applied to one surface of the barrier layer by a dry lamination method, and the printed layer side of the base material layer is dried on the resin composition by a dry lamination method. After lamination, the substrate was subjected to an aging treatment to produce a laminate of a base material layer / printing layer / adhesive layer / barrier layer. Incidentally, a chemical conversion treatment was applied to both surfaces of the aluminum alloy foil. The chemical conversion treatment of the aluminum alloy foil is performed by a roll coating method using a treatment solution comprising a phenol resin, a chromium fluoride compound, and phosphoric acid so that the applied amount of chromium is 10 mg / m ² (dry mass). And baking. Next, on the barrier layer of the laminate, a maleic anhydride-modified polypropylene (disposed on the barrier layer side, thickness: 15 μm) as an adhesive layer, and a random polypropylene (disposed on the innermost layer side) as a heat-fusible resin layer, (Thickness: 20 μm), the adhesive layer and the heat-fusible resin layer are respectively laminated on the barrier layer, and the substrate layer / print layer / adhesive layer / barrier layer / adhesive layer / heat-fusible A packaging material for an electricity storage device in which resin layers were sequentially laminated was obtained. The peel strength of the obtained packaging material for an electric storage device was measured in the same manner as in Example 1-10 and Comparative Example 1-2. As a result, it was 2.15 N / 15 mm.

(Evaluation of application to all solid state batteries)
As described above, in the all-solid-state battery, friction occurs on the outer layer surface during expansion / contraction or pressure restraint, and the battery is easily peeled off by conventional printing. The following method was used to confirm whether the packaging materials for power storage devices obtained in Examples 1 to 10 can be suitably used for all-solid-state batteries. Using AB-301 COLOR FASTNESS RUBBING TESTER (AB-301 COLOR FASTNESS RUBBING TESTER (TESTER SANGYO CO., LTD.)) With a 300 g load, steel wool, and a substrate. After 10 reciprocations, the surface of the base material layer was visually checked. The test speed was SPEED CONTROL 100 (corresponding to a maximum speed of 30 cpm × 100% = 120 mm / s), the movement width was 100 mm, the load was 300 g, and the sample size was 250 mm (MD) × 2.5 mm (TD). As a result, it was confirmed that the packaging materials for power storage devices of Examples 1 to 10 did not peel off the printing, and could be suitably used as a packaging material for an all-solid-state battery. On the other hand, except that the lamination position of the printing layer was set to the outside of the base material layer (that is, the outermost layer of the packaging material for an electricity storage device becomes the printing layer), the packaging for the electricity storage device produced in the same manner as in Comparative Example 3 When the material was evaluated for application to an all-solid-state battery in the same manner as in Examples 1 to 10, the printed layer was peeled off, and it was confirmed that the material was not suitable for application to an all-solid-state battery.

REFERENCE SIGNS LIST 1 base material layer 2 adhesive layer 3 barrier layer 4 heat-fusible resin layer 5 adhesive layer 6 surface coating layer 10 packaging material for power storage device

Claims (12)

At least a positive electrode, a negative electrode, and a power storage device element including an electrolyte are housed in a package made of a power storage device packaging material, a power storage device,
The packaging material for the electricity storage device is at least composed of a laminate including a base layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer in this order,
The adhesive layer is in contact with the barrier layer,
The power storage device, wherein the adhesive layer includes a material that can form an image by irradiation with a laser beam. The power storage device according to claim 1, wherein the content of the material capable of forming an image by laser beam irradiation is 0.1 to 50% by mass in the adhesive layer. 3. The power storage device according to claim 1, wherein the material capable of forming an image by irradiation with a laser beam includes a bismuth-based compound. 4. (4) The power storage device according to any one of (1) to (3), wherein the material capable of forming an image by irradiation with a laser beam contains a black pigment. (5) The power storage device according to any one of (1) to (4), wherein an image is formed on the adhesive layer. (6) The power storage device according to any one of (1) to (5), wherein the adhesive strength between the base layer and the barrier layer is 3 N / 15 mm or more. The power storage device according to any one of claims 1 to 6, wherein an image is formed on the adhesive layer. The power storage device according to any one of claims 1 to 6, wherein an image that is visible from the outside is formed. At least, a base layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer, which is composed of a laminate including in this order,
The adhesive layer is in contact with the barrier layer,
The packaging material for an electric storage device, wherein the adhesive layer includes a material that enables an image to be formed by irradiation with a laser beam. At least, a step of laminating the base material layer, the adhesive layer, the barrier layer, and the heat-fusible resin layer in this order,
The adhesive layer is in contact with the barrier layer,
The adhesive layer includes a material that enables image formation by irradiation with laser light,
A method for producing a packaging material for a power storage device. A housing step of housing at least a positive electrode, a negative electrode, and a power storage device element including an electrolyte in a package made of the power storage device packaging material according to claim 9,
Before or after the accommodation step, irradiating the adhesive layer with a laser beam to form an image,
A method for manufacturing a power storage device, comprising: The laser beam, YAG laser beam, YVO ₄ laser, or a fiber laser beam, method for producing the electric storage device according to claim 11.

Images