KR20200096494A - Battery packaging material, battery, manufacturing method thereof, and polyester film - Google Patents

Abstract

At least, it is composed of a laminate comprising a substrate layer, a barrier layer, and a heat-fusible resin layer positioned on the outermost surface in this order, and the outermost surface of the substrate layer is composed of a polyester film layer, and Fourier A battery packaging material that satisfies the following equation when obtaining an infrared absorption spectrum in 18 directions in increments of 10° from 0° to 170° with respect to the surface of the polyester film layer using the total reflection method of the converted infrared spectroscopy method :
Y _max /Y _min <1.4

Description

Battery packaging material, battery, manufacturing method thereof, and polyester film

The present invention relates to a battery packaging material, a battery, a manufacturing method thereof, and a polyester film.

Conventionally, various types of batteries have been developed, but in all batteries, packaging materials have become an indispensable member for sealing battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been widely used as packaging for batteries.

On the other hand, in recent years, along with the high performance of electric vehicles, hybrid electric vehicles, computers, cameras, mobile phones, etc., various shapes are required for batteries, and thinner and lighter weights are also required. However, in the metal battery packaging material that has been widely used in the past, it is difficult to keep up with the diversification of shapes, and there is a drawback in that there is a limit to weight reduction.

Therefore, in recent years, as a battery packaging material that can be easily processed into various shapes and can realize thinner or lighter weight, a film-type laminate in which a substrate/barrier layer/heat-fusible resin layer is sequentially laminated has been proposed. (For example, refer to patent document 1). In such a battery packaging material, in general, a concave portion is formed by cold forming, and a battery element such as an electrode or an electrolyte is disposed in a space formed by the concave portion, and heat-fusible resin layers are thermally fused together. A battery in which a battery element is housed inside a battery packaging material is obtained.

In the various packaging materials composed of the above laminate, in a method of printing ink on the surface of the substrate layer to form barcodes, patterns, characters, etc., and laminating an adhesive and a barrier layer on the substrate layer on the printed side. Accordingly, a method of printing a packaging material (generally referred to as reverse printing) is widely adopted. However, if such a printing surface exists between the substrate layer and the barrier layer, the adhesion between the substrate layer and the barrier layer decreases, and delamination tends to occur between layers. Particularly, since high safety is required for a battery to which a battery packaging material is applied, such a method of printing by reverse printing has been elaborated in battery packaging materials. Therefore, conventionally, in the case of forming printing such as a barcode on a battery packaging material, a method of attaching a seal on which printing is formed to the surface of a base layer is generally employed.

Japanese Laid-Open Patent No. 2008-287971

However, when the sealing on which the printing is formed is attached to the surface of the base layer, the thickness and weight of the battery packaging material increase. Accordingly, the present inventors considered a method of printing directly on the surface of the base layer of the battery packaging material by printing ink in consideration of the recent trend of further reduction in thickness and weight of the battery packaging material.

As a method of printing directly on the surface of the substrate layer of a battery packaging material by ink printing, for example, pad printing (also referred to as tampon printing) or inkjet printing is known. Pad printing is the following printing method. First, ink is poured into the concave portion of the plate on which the pattern to be printed is etched. Next, the silicon pad is pressed against the concave portion to transfer ink to the silicon pad. Next, the ink transferred to the surface of the silicon pad is transferred to the object to be printed, and printing is formed on the object to be printed. In such pad printing, since ink is transferred to the object to be printed by using an elastic silicone pad, etc., it is easy to print on the surface of the battery packaging material after molding, and after sealing the battery element with the battery packaging material, printing on the battery is performed. It has the advantage of being able to. In addition, it has the same advantage in inkjet printing.

By the way, as the inventors studied, in a battery packaging material having a polyester film layer on the outermost surface, when ink is printed on the surface of the polyester film layer, the expansion of ink on the surface of the polyester film layer The problem was found that it is difficult to form a print of a desired size and shape, because the dot of the printing portion formed by ink tends to become disproportionate, or the dots of the printing portion formed by ink tend to become distorted.

Under such circumstances, the main object of the present invention is to provide a battery packaging material having a polyester film layer on the outermost surface and excellent in printing aptitude on the surface of the polyester film layer.

In order to solve the above problems, the present inventor has conducted a careful examination. As a result, at least, it is composed of a laminate comprising a substrate layer, a barrier layer, and a heat-fusible resin layer located on the outermost surface in this order, and the outermost surface of the substrate layer is composed of a polyester film layer. , Using the total reflection method of Fourier transform infrared spectroscopy, for the surface of the polyester film layer, in the case of obtaining an infrared absorption spectrum of 18 directions in increments of 10° from 0° to 170°, the battery packaging satisfying the following equation As for the material, it was found that the expansion of the ink on the surface of the polyester film layer became inappropriate or that the dots of the printing portion became crushed, and excellent printing aptitude was exhibited.

Y _max /Y _min <1.4

Y _max is the maximum of the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. .

Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions.

In the calculation of the maximum value Y _max and the minimum value Y _min , Y ₁₃₄₀ /Y ₁₄₁₀ is obtained for each of the 18 directions, and from these, the maximum value Y _max and the minimum value Y _min are respectively selected.

The present invention has been completed by repeating further studies based on these findings.

That is, the present invention provides the invention of the aspect shown below.

Item 1. At least, it is composed of a laminate comprising a substrate layer, a barrier layer, and a heat-fusible resin layer located on the outermost surface in this order,

The outermost surface of the substrate layer is composed of a polyester film layer,

Battery packaging that satisfies the following equation when obtaining an infrared absorption spectrum in 18 directions in increments of 10° from 0° to 170° with respect to the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy material.

Y _max /Y _min <1.4

Y _max is the maximum value obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. .

Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions.

Item 2. The battery packaging material according to item 1, which is used for a purpose in which printing is performed on the surface of the polyester film layer.

Item 3. The battery packaging material according to item 1 or 2, wherein the arithmetic mean roughness Ra measured with respect to the surface of the polyester film layer is 10 nm or more according to the method specified in JIS B 0601-2001.

Item 4. An adhesive layer is provided between the barrier layer and the heat-fusible resin layer,

The battery packaging material according to any one of items 1 to 3, wherein the adhesive layer contains an acid-modified polyolefin.

Item 5. The acid-modified polyolefin of the adhesive layer is maleic anhydride-modified polypropylene,

The battery packaging material according to item 4, wherein the heat-fusible resin layer contains polypropylene.

Item 6. Any one of items 4 to 5, wherein the adhesive layer is a cured product of a resin composition comprising 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. The battery packaging material described in.

Item 7. Any one of items 4 to 6, wherein the adhesive layer is a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of an oxygen atom, a heterocycle, a C=N bond, and a COC bond. The battery packaging material described in.

Item 8. The battery packaging material according to any one of items 4 to 7, wherein the adhesive layer contains at least one selected from the group consisting of urethane resin, ester resin, and epoxy resin.

Item 9. The battery packaging material according to any one of items 4 to 8, wherein the thickness of the adhesive layer is 50 µm or less.

Item 10. The battery packaging material according to any one of items 4 to 8, wherein the adhesive layer has a thickness of 10 µm or more and 50 µm or less.

Item 11. The battery packaging material according to any one of items 4 to 10, which is a coextruded laminate of the adhesive layer and the heat-fusible resin layer.

Item 12. The battery packaging material according to any one of items 1 to 11, wherein the polyester film layer has a thickness of 10 µm or more and 50 µm or less.

Item 13. The battery packaging material according to any one of items 1 to 12, wherein the polyester film layer is formed of a stretched polyester film.

Item 14. Using the total reflection method of Fourier transform infrared spectroscopy, in the case of obtaining the infrared absorption spectrum in 18 directions by 10° from 0° to 170° for the surface of the polyester film layer, the following equation is satisfied. And the battery packaging material according to any one of items 1 to 13.

1.1≤Y _max /Y _min <1.4

Item 15. An acid-resistant film is provided on at least one surface of the barrier layer,

With respect to the acid-resistant film, the time-of-flight when analyzed using a secondary ion mass spectrometry, Ce ₂ PO ₄ ^+, CePO ₄ ^- at least one member selected from the group consisting of ^-, CrPO ₂ ^+, and CrPO ₄ The battery packaging material according to any one of items 1 to 14, wherein the derived peak is detected.

Item 16. Items 1 to 15, wherein at least one surface of the barrier layer is provided with an acid-resistant coating comprising at least one selected from the group consisting of phosphorus compounds, chromium compounds, fluorides, and triazinethiol compounds. The battery packaging material according to any one of claims.

Item 17. The battery packaging material according to any one of items 1 to 16, wherein an acid-resistant film containing a cerium compound is provided on at least one surface of the barrier layer.

Item 18. The battery packaging material according to any one of items 1 to 17, wherein a lubricant is present in at least one of the inside and the surface of the polyester film layer.

Item 19. A battery, wherein a battery element including at least a positive electrode, a negative electrode, and an electrolyte is accommodated in a package formed of the battery packaging material according to any one of items 1 to 18.

Item 20. The battery according to item 19, having a printing portion on the surface of the polyester film layer.

Item 21. An accommodation step of accommodating a battery element provided with at least a positive electrode, a negative electrode, and an electrolyte in a package made of the battery packaging material according to any one of items 1 to 18;

Step of performing printing on the surface of the polyester film layer in at least one of before and after the receiving step

Containing, the method of manufacturing a battery.

Item 22. A polyester film for use in a polyester film layer positioned on the outermost surface of a battery packaging material,

A polyester film that satisfies the following formula when obtaining an infrared absorption spectrum of 18 directions in increments of 10° from 0° to 170° for the surface of the polyester film by using the total reflection method of Fourier transform infrared spectroscopy. .

Y _max /Y _min <1.4

Y _max is the maximum value obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. .

Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions.

Item 23. A polyester that satisfies the following equation when the infrared absorption spectrum in 18 directions is obtained in increments of 10° from 0° to 170° on the surface of the polyester film by using the total reflection method of Fourier transform infrared spectroscopy. Use of a film as a polyester film layer positioned on the outermost surface of a battery packaging material.

Y _max /Y _min <1.4

Y _max is the maximum of the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. .

Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions.

ADVANTAGE OF THE INVENTION According to this invention, in the battery packaging material provided with the polyester film layer on the outermost surface, it is possible to provide the battery packaging material excellent in printing suitability of the surface of the said polyester film layer.

1 is a diagram showing an example of a cross-sectional structure of a battery packaging material of the present invention.
Fig. 2 is a diagram showing an example of a cross-sectional structure of the battery packaging material of the present invention.
3 is a diagram showing an example of a cross-sectional structure of the battery packaging material of the present invention.
4 is an image of a printing portion formed on the surface of a biaxially stretched polyethylene terephthalate film observed with a laser microscope in Example 2;
Fig. 5 is an image of a printing portion formed on the surface of a biaxially stretched polyethylene terephthalate film observed with a laser microscope for Comparative Example 7.

The battery packaging material of the present invention is composed of a laminate comprising at least a base layer, a barrier layer, and a heat-fusible resin layer positioned on the outermost surface in this order, and the outermost surface of the base layer is a polyester film layer. In the case of obtaining an infrared absorption spectrum in 18 directions in increments of 10° from 0° to 170° for the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy, the following equation It characterized in that it meets. Hereinafter, the battery packaging material of the present invention will be described in detail.

Y _max /Y _min <1.4

In the above equation, Y _max is the absorption peak intensity Y ₁₃₄₀ (CH ₂ vertical vibration) at wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum, respectively, in each direction in the 18 directions, absorption at wave number 1410 cm ^-1 Peak intensity Y is the maximum value divided by ₁₄₁₀ (C=C stretching vibration).

Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions.

In the calculation of the maximum value Y _max and the minimum value Y _min , Y ₁₃₄₀ /Y ₁₄₁₀ is obtained for each of the 18 directions, and from these, the maximum value Y _max and the minimum value Y _min are respectively selected.

Hereinafter, the battery packaging material of the present invention will be described in detail. And in this specification, about the numerical range, the numerical range represented by "-" means "above" and "below". For example, the notation of 2-15 mm means 2 mm or more and 15 mm or less.

1. Laminated structure of battery packaging materials

The battery packaging material of the present invention includes, for example, a base layer 1, a barrier layer 3, and a heat-sealable resin layer 4 positioned on the outermost surface as shown in FIG. 1 in this order. It becomes a laminated body. In addition, the outermost surface of the base material layer 1 is constituted by a polyester film layer. In the battery packaging material of the present invention, the polyester film layer becomes the outermost layer side, and the heat-fusible resin layer 4 becomes the innermost layer. That is, at the time of assembling the battery, the heat-fusible resin layers 4 positioned at the peripheral edges of the battery element are thermally fused to seal the battery element, thereby sealing the battery element.

As described later, the base material layer 1 may be provided with another layer in addition to the polyester film layer. Moreover, when the base material layer 1 includes the said other layer, the polyester film layer and another layer may be bonded by an adhesive layer. In addition, the battery packaging material of the present invention is, for example, as shown in Fig. 2, between the base layer 1 and the barrier layer 3, for the purpose of improving the adhesion thereof, if necessary an adhesive layer ( You may have 2). Further, between the barrier layer 3 and the heat-fusible resin layer 4, an adhesive layer 5 may be formed as necessary for the purpose of improving their adhesiveness.

The total thickness of the laminate constituting the battery packaging material of the present invention is not particularly limited, but from the viewpoint of improving the moldability while making the total thickness of the laminate as thin as possible, it is preferably about 180 μm or less, more preferably About 35 to 160 micrometers, More preferably, about 45 to 150 micrometers is mentioned.

The battery packaging material of the present invention can be preferably used for applications in which printing is performed on the surface of the polyester film layer located on the outermost surface. As printing by ink, for example, the above-described pad printing, inkjet printing, etc. are suitable, and in particular, inkjet printing is suitable. Examples of the solvent contained in the ink include methyl ethyl ketone, acetone, isopropyl alcohol, and ethanol. The solvent may be used individually by 1 type, and may be used in combination of 2 or more types.

2. Each layer forming battery packaging material

[Substrate layer (1)]

In the battery packaging material of the present invention, the base layer 1 is a layer located on the outermost surface. The outermost surface of the base material layer 1 is constituted by a polyester film layer. And in the present invention, even when the lubricant is present on the surface of the polyester film layer, the polyester film layer to which the lubricant is adhered constitutes the outermost surface of the battery packaging material. Therefore, also for the base layer 1 on which the lubricant is present on the surface, the base layer 1 is a layer located on the outermost surface of the battery packaging material.

In the battery packaging material of the present invention, the polyester film layer constituting the outermost surface is 10° from 0° to 170° with respect to the surface of the polyester film layer using a total reflection method of Fourier transform infrared spectroscopy. In the case of obtaining the infrared absorption spectra of 18 directions each, it is characterized by satisfying the following equation.

Y _max /Y _min <1.4

Y _max is the maximum of the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. .

In addition, Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each direction in the 18 directions, respectively. to be.

In the calculation of the maximum value Y _max and the minimum value Y _min , Y ₁₃₄₀ /Y ₁₄₁₀ is obtained for each of the 18 directions, and from these, the maximum value Y _max and the minimum value Y _min are respectively selected.

In the battery packaging material of the present invention, the outermost surface of the substrate layer is constituted by a polyester film layer, and the polyester film layer has the specific surface orientation degree, so that the outermost surface is a polyester film. Despite being constituted by, excellent printing aptitude is exhibited. As this mechanism, for example, it can be considered as follows. That is, in the battery packaging material of the present invention, since the polyester film layer constituting the outermost surface has the specific surface orientation degree, it can be said that the orientation degree of the polyester molecules in the polyester film layer is low. For this reason, on the surface of the polyester film layer, it is considered that ink is easily spread in a uniform direction, and excellent printing suitability is exhibited. In the conventional battery packaging material, when using a polyester film layer for the base layer, from the viewpoint of enhancing moldability, etc., a polyester film having a high degree of orientation of polyester molecules has been used by greatly stretching the polyester film. In the invention, excellent printing aptitude is exhibited by having the surface orientation degree with respect to the polyester film layer constituting the outermost surface. There exists a method of improving printing aptitude by making a lubricant present on the surface of the substrate layer or by performing a surface treatment on the substrate layer, and this method can also be employed in the present invention, but in the present invention, a polyester film Since the layer has the specific degree of surface orientation, excellent printing aptitude is exhibited even though the outermost surface is made of a polyester film.

Measurement conditions in which the infrared absorption spectrum is specific are as follows. And the measurement of the infrared absorption spectrum on the surface of the polyester film layer can be performed in the state of being laminated on the battery packaging material.

(Infrared absorption spectrum measurement conditions)

Spectroscope (single reflection ATR accessory included)

Detector: MCT (Hg Cd Te)

Wavenumber resolution: 8cm ^-1

Total number of times: 128

IRE: Ge

Incidence angle: 30°

Polarizer: wire grid, S polarization

Baseline: average value of intensity in the range of 1800 to 2000 cm ^-1 wavenumber

Absorption peak intensity at wavenumber 1340cm ^-1 Y ₁₃₄₀ : The maximum value of peak intensity in the range of wavenumber 1335∼1342cm ^-1 minus the value of baseline

Absorption peak intensity at wave number 1410cm ^-1 Y ₁₄₁₀ : The maximum value of peak intensity in the range of wavenumber 1400 to 1410cm ^-1 minus the value of baseline

Acquisition of the infrared absorption spectrum in the 18 directions is performed by placing the sample exposed with the polyester film horizontally on the sample holder and rotating by 10° for each Ge crystal placed on the sample. The angle of incidence is the angle between the perpendicular (normal) and incident light.

From the viewpoint of improving the printing aptitude of the battery packaging material, the surface orientation degree (Y _max /Y _min ) is less than 1.4 with respect to the upper limit. For the upper limit, preferably about 1.3 or less, and for the lower limit, preferably about 1.0 or more, more preferably about 1.1 or more, more preferably about 1.2 or more, and for a preferred range , About 1.0 or more and less than 1.4, about 1.0 to 1.3, about 1.1 or more and less than 1.4, about 1.1 to 1.3, about 1.2 or more and less than 1.4, about 1.2 to 1.3, and the like. When the surface orientation degree (Y _max /Y _min ) is about 1.1 or more, the moldability can be preferably improved while improving the printing aptitude of the battery packaging material.

The polyester film having the above-described degree of surface orientation: Y _max /Y _min is appropriately adjusted, for example, the stretching method, stretching ratio, stretching rate, cooling temperature, heat setting temperature, etc. when producing a polyester film. It can be manufactured by doing.

In addition, in the battery packaging material of the present invention, as the arithmetic average roughness Ra of the polyester film layer constituting the outermost surface, from the viewpoint of improving the printing aptitude of the battery packaging material, the upper limit is preferably about 1000 nm. Hereinafter, more preferably, about 500 nm or less, for the lower limit, preferably about 10 nm or more, more preferably about 20 nm or more, and about 10 to 1000 nm for a preferred range. , About 20 to 500 nm is mentioned.

The arithmetic average roughness Ra of the polyester film layer constituting the outermost surface is a value obtained with respect to the surface of the polyester film layer in accordance with the method specified in JIS B 0601-2001. For a specific measurement method, the method described in Examples can be adopted. In addition, the measurement of the arithmetic average roughness Ra of the polyester film layer can be performed in a state of being laminated on a battery packaging material.

The arithmetic average roughness Ra of the surface of the polyester film layer can be adjusted by the height and density of the irregularities on the surface of the cooling roll when producing the polyester film. In addition, the polyester film layer may contain additives (flame retardant, anti-blocking agent, antioxidant, light stabilizer, tackifier, antistatic agent, etc.) described later as particles, and the arithmetic average roughness Ra is adjusted by the particles. You can do it. The average particle diameter of the particles is, for example, about 0.1 to 5 µm, and the content of the particles is, for example, about 0.01 to 0.1 mass%.

As the polyester constituting the polyester film layer, specifically, copolymerization of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and ethylene terephthalate as the main body of the repeating unit And copolymerized polyesters containing polyester and butylene terephthalate as a main body of a repeating unit. In addition, as a copolymerized polyester containing ethylene terephthalate as the main body of the repeating unit, specifically, a copolymer polyester polymerized with ethylene isophthalate using ethylene terephthalate as the main body of the repeating unit (hereinafter, polyethylene (terephthalate/isophthalate) ), polyethylene (terephthalate/isophthalate), polyethylene (terephthalate/adipate), polyethylene (terephthalate/sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/isophthalate) Phthalate/phenyl-dicarboxylate), polyethylene (terephthalate/decanedicarboxylate), etc. are mentioned. In addition, as a copolymer polyester having butylene terephthalate as the main body of the repeating unit, specifically, a copolymer polyester in which butylene terephthalate as the main body of the repeating unit and polymerizing with butylene isophthalate (hereinafter, polybutylene ( Terephthalate/isophthalate), polybutylene (terephthalate/adipate), polybutylene (terephthalate/sebacate), polybutylene (terephthalate/decanedicarboxylate), polybutyl Rennaphthalate, etc. are mentioned. These polyesters may be used alone, or may be used in combination of two or more. Polyester is advantageous in that it is excellent in heat resistance and electrolyte resistance, and it is difficult to cause whitening or the like with respect to adhesion of an electrolyte solution, and is therefore preferably used as a material for forming the base layer 1.

The polyester film layer may be either a stretched polyester film or an unstretched polyester film, but from the viewpoint of preferably improving the moldability of the battery packaging material, preferably a stretched polyester film, more preferably a biaxial It can be composed of a stretched polyester film, more preferably a biaxially stretched polyethylene terephthalate film. And as a stretching method, a sequential biaxial stretching method, inflation, simultaneous biaxial stretching method, etc. are mentioned, for example.

The thickness of the polyester film layer is not particularly limited, but from the viewpoint of improving moldability while thinning the battery packaging material, the upper limit is, for example, about 50 µm or less, preferably about 30 µm or less, more preferably Preferably, about 25 µm or less may be mentioned, and the lower limit is preferably about 1 µm or more, more preferably about 5 µm or more, and further about 10 µm or more, and for a preferred range, 1 to 50 About ㎛, about 1~30㎛, about 1~25㎛, about 5~50㎛, about 5~30㎛, about 5~25㎛, about 10~50㎛, about 10~30㎛, about 10~25㎛ Can be mentioned.

The polyester film layer may be a single layer or a multilayer (multilayer structure). And when the polyester film layer is a multilayer, it is sufficient that the polyester film located at least on the outermost layer side (the side opposite to the barrier layer 3) satisfies the above-described surface orientation degree, and the other polyester film, Surface orientation degree: Y _max /Y _min may be 1.4 or more.

In addition, for the purpose of improving the moldability of the battery packaging material, the base layer 1 is, in addition to the polyester film layer, on the barrier layer side of the polyester film layer, a resin of a material different from polyester. At least one of a film and a coating may be laminated (multilayered structure) to form the base layer 1.

Other resin films used for the base layer 1 include, for example, polyamide, polyolefin, epoxy resin, acrylic resin, fluorine resin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and these A resin film composed of a mixture or copolymer or the like can be mentioned. As a specific example of a structure in which a polyester film and a resin film of a different material are laminated, a multilayer structure in which a polyester film layer and a polyamide film layer are laminated may be mentioned.

Specific examples of the polyamide film constituting the polyamide film layer include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 66; Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamides, such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing structural units derived from terephthalic acid and/or isophthalic acid Polyamides containing aromatics such as polyamide MXD6 (polymethaxylylene adipamide); Alicyclic polyamides such as polyaminomethylcyclohexyladipamide (PACM6); In addition, polyamides obtained by copolymerizing lactam components and isocyanate components such as 4,4'-diphenylmethane-diisocyanate, polyesteramide copolymers or polyether esters that are copolymers of copolymerized polyamides and polyesters or polyalkylene ether glycols Amide copolymer; Polyamide films, such as these copolymers, are mentioned. These polyamide films may be used alone or in combination of two or more. The polyamide film is excellent in stretchability, can prevent the occurrence of whitening due to resin cracking during molding, and is preferably used as a resin film used for the base layer 1 together with a polyester film.

As a specific example of the case where the base material layer 1 is a multilayer structure of a polyester film and a case where the other resin film is provided, a laminate of a polyester film and a nylon film, and a laminate obtained by laminating a plurality of polyester films are preferable. , A laminate of a stretched polyester film and a stretched nylon film, and a laminate obtained by laminating a plurality of stretched polyester films are more preferable. For example, when the base layer 1 has a two-layer structure, it is preferable to have a structure in which a polyester film and a polyamide film are laminated, or a structure in which a polyester film and a polyester film are laminated, and polyethylene terephthalate It is more preferable to have a structure in which and nylon are laminated, or a structure in which polyethylene terephthalate and polyethylene terephthalate are laminated. In addition, the polyester film is hardly discolored when, for example, an electrolyte is adhered to the surface, and in the battery packaging material of the present invention, the polyester film layer constitutes the outermost surface, so that the composition has excellent electrolyte resistance. You can do it.

When the base layer 1 has a multilayer structure, the thickness of the polyester film not located on the outermost layer or the resin film other than the polyester film, with respect to the lower limit, is preferably about 3 μm or more, more preferably About 5 μm or more may be mentioned, and the upper limit is preferably about 30 μm or less, preferably about 25 μm or less, and for a preferred range, about 3 to 30 μm, about 3 to 25 μm, About 5 to 30 micrometers and about 5 to 25 micrometers are mentioned.

When the base material layer 1 has a multilayer structure, the polyester film and each resin film may be bonded through an adhesive, or may be directly laminated without passing through the adhesive. In the case of bonding without passing through an adhesive, for example, a method of bonding in a heat-melted state such as a coextrusion method, a sandwich lamination method, and a thermal lamination method may be mentioned. In the case of bonding through an adhesive, the adhesive to be used may be a two-liquid curable adhesive or a one-liquid curable adhesive. Further, the bonding mechanism of the adhesive is not particularly limited, and may be a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, an electron beam curing type or an ultraviolet curing type. As a specific example of an adhesive, the thing similar to the adhesive exemplified by the adhesive layer 2 is mentioned. In addition, the thickness of the adhesive may be similar to that of the adhesive layer 2.

In addition, when the base layer 1 has a multilayer structure, as the adhesive for bonding the polyester film or each resin film, preferably, a resin composition containing a modified thermoplastic resin graft-modified with an unsaturated carboxylic acid derivative component is used. Can be heard. As the modified thermoplastic resin, preferably, a resin obtained by modifying a polyolefin, a styrene-based elastomer, a polyester-based elastomer, or the like with an unsaturated carboxylic acid derivative component is mentioned. This resin may be used individually by 1 type, and may be used in combination of 2 or more types. Moreover, as an unsaturated carboxylic acid derivative component, an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, an ester of an unsaturated carboxylic acid, etc. are mentioned. As the unsaturated carboxylic acid derivative component, one type may be used alone, or two or more types may be used in combination.

Examples of the polyolefin in the modified thermoplastic resin include low density polyethylene, medium density polyethylene, and high density polyethylene; Ethylene-?olefin copolymer; Homo, block or random polypropylene; Propylene-?olefin copolymer; Copolymers obtained by copolymerizing polar molecules such as acrylic acid and methacrylic acid with the above materials; Polymers, such as a crosslinked polyolefin, etc. are mentioned. One type of polyolefin may be used alone, or a combination of two or more types may be used.

Examples of the styrenic elastomer in the modified thermoplastic resin include a copolymer of styrene (hard segment), butadiene or isoprene, or a hydrogenated product thereof (soft segment). One type of polyolefin resin may be sufficient, and a combination of two or more types may be sufficient as it.

Examples of the polyester elastomer in the modified thermoplastic resin include a copolymer of crystalline polyester (hard segment) and polyalkylene ether glycol (soft segment). One type of polyolefin may be used alone, or a combination of two or more types may be used.

Examples of unsaturated carboxylic acids in the modified thermoplastic resin include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and bicyclo[2,2,1]hepto-2-ene. -5,6-dicarboxylic acid, etc. are mentioned. In addition, as an acid anhydride of an unsaturated carboxylic acid, for example, maleic anhydride, itaconic anhydride, cytraconic anhydride, tetrahydrophthalic anhydride, bicyclo[2,2,1]hepto-2-ene-5,6- Dicarboxylic anhydride and the like. In addition, as an ester of an unsaturated carboxylic acid, for example, methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, diethyl fumarate, dimethyl itaconic acid, citracone Esters of unsaturated carboxylic acids such as diethyl acid, dimethyl tetrahydrophthalate anhydride, and dimethyl bicyclo[2,2,1]hepto-2-ene-5,6-dicarboxylic acid.

As the modified thermoplastic resin, it is obtained by reacting about 0.2 to 100 parts by mass of the unsaturated carboxylic acid derivative component by heating in the presence of a radical initiator with respect to 100 parts by mass of the base thermoplastic resin.

The reaction temperature is preferably about 50 to 250°C, more preferably about 60 to 200°C. The reaction time also depends on the production method, but in the case of a melt graft reaction by a twin screw extruder, about 2 to 30 minutes, which is within the residence time of the extruder, is preferable, and about 5 to 10 minutes is more preferable. In addition, the denaturation reaction can be carried out under any conditions of normal pressure and pressurization.

Examples of the radical initiator used in the modification reaction include organic peroxides. As the organic peroxide, various materials can be selected depending on temperature conditions and reaction time. For example, alkyl peroxide, aryl peroxide, acyl peroxide, ketone peroxide, peroxy ketal, peroxy carbonate, peroxy ester, Hydroperoxide, etc. are mentioned. In the case of the melt graft reaction by the above-described twin screw extruder, alkyl peroxide, peroxy ketal, and peroxy ester are preferable, and di-tert-butyl peroxide, 2,5-dimethyl-2,5-di- It is more preferable to use tert-butylperoxy-hexine-3 and dicumyl peroxide.

When the base material layer 1 has a multilayer structure, the thickness of the adhesive layer positioned between the polyester film or each resin film is preferably about 0.1 to 5 µm, more preferably about 0.5 to 3 µm. I can. In addition, the adhesive layer may contain the same colorant as the adhesive layer 2 described later.

In the present invention, from the viewpoint of improving the moldability of the battery packaging material, it is preferable that the lubricant is present in at least one of the inside and the surface of the polyester film layer. That is, the lubricant may be contained in the polyester film layer, or the lubricant may be present on the surface of the battery packaging material. Further, the lubricant present on the surface of the polyester film layer may be one that exudes the lubricant contained in the polyester film layer, or may be a lubricant applied to the surface of the polyester film layer.

Although it does not specifically limit as a lubricant, Preferably, an amide type lubricant and a silicone type lubricant are mentioned. 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, fatty acid ester amide, and aromatic bisamide. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid 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-oleylpalmitic acid amide, N-stearyl stearic acid amide, N-stearyloleic acid amide, N-oleylstearic acid amide, and N-stearyl erucic acid amide. . Moreover, methylol stearic acid amide etc. are mentioned as a specific example of methylolamide. Specific examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, and hexamethylenebis Stearic acid amide, hexamethylenebisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyladipic acid amide, and N,N'-distearyl sebacic acid amide. As a specific example of the unsaturated fatty acid bisamide, ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N'-dioleyyladipic acid amide, N,N'-dioleyyl sebacic acid amide, etc. Can be heard. As a specific example of fatty acid ester amide, stearamide ethyl stearate etc. are mentioned. Further, specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide. Further, as the silicone lubricant, non-reactive modified silicone oils such as alkyl modified silicone oils, higher fatty acid ester modified silicone oils, and polyether modified silicone oils are preferred. Lubricants may be used alone or in combination of two or more.

When the lubricant is present on the surface of the polyester film layer, the amount of the lubricant is not particularly limited, but from the viewpoint of exhibiting excellent printing properties, it is preferably about 3 mg/m 2 or more, more preferably about 3 to 15 mg/m 2 , More preferably about 4 to 14 mg/m 2. And even when the lubricant is present on the surface of the polyester film layer, it is possible to measure the above infrared absorption spectrum with respect to the surface of the polyester film layer where the lubricant is present on the surface.

Further, additives such as flame retardants, anti-blocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be present in at least one of the inside and the surface of the base layer 1. Only one type of additive may be used, or two or more types may be mixed and used.

The thickness (total thickness) of the substrate layer 1 is not particularly limited, but from the viewpoint of improving moldability while reducing the thickness of the battery packaging material, the upper limit is, for example, about 50 μm or less, preferably about 40 μm. The following can be mentioned, and the lower limit is preferably about 3 µm or more, more preferably about 5 µm or more, even more preferably about 10 µm or more, and the preferred thickness of the base layer 1 is , About 3 to 50 µm, about 3 to 40 µm, about 5 to 50 µm, about 5 to 40 µm, about 10 to 50 µm, and about 10 to 40 µm.

[Adhesive layer (2)]

In the battery packaging material of the present invention, the adhesive layer 2 is a layer formed between the base layer 1 and the barrier layer 3, if necessary, in order to firmly adhere the base layer 1 and the barrier layer 3 therebetween.

The adhesive layer 2 is formed of an adhesive capable of bonding the base layer 1 and the barrier layer 3 to each other. The adhesive used for forming the adhesive layer 2 may be a two-liquid curable adhesive or a one-liquid curable adhesive. Further, the bonding mechanism of the adhesive used for forming the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a hot melting type, a hot pressure type, and the like.

As an adhesive component that can be used for the formation of the adhesive layer 2, specifically, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester; Polyether adhesives; Polyurethane adhesive; Epoxy resin; Phenolic resin; Polyamides such as nylon 6, nylon 66, nylon 12, and copolymerized polyamide; Polyolefins such as polyolefin, carboxylic acid-modified polyolefin, and metal-modified polyolefin, and polyvinyl acetate; Cellulose adhesive; (Meth)acrylic resin; Polyimide; Polycarbonate; Amino resins such as urea resin and melamine resin; Rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; And silicone resins. These adhesive components may be used individually by 1 type, and may be used in combination of 2 or more types. Among these adhesive components, a polyurethane adhesive is preferably used.

As a polyurethane adhesive, it is a polyurethane adhesive containing a main material containing a polyol component (A) and a curing agent containing a polyisocyanate component (B), and the polyol component (A) is a polyester polyol (A1). Containing, and polyester polyol (A1) is a polyester polyol having a number average molecular weight of 5000 to 500,000 composed of a polybasic acid component and a polyhydric alcohol component, containing 45 to 95 mol% of an aromatic polybasic acid component in 100 mol% of the polybasic acid component, , The tensile stress at the time of 100% elongation of the adhesive layer is 100 kg/cm 2 or more and 500 kg/cm 2 or less. In addition, as a polyurethane adhesive for battery packaging materials containing a main material and a polyisocyanate curing agent, 5 to 50% by weight of a polyester polyol (A1) having a main value, a glass transition temperature of 40°C or higher, and a polyester polyol having a glass transition temperature of less than 40°C. (A2) The equivalent ratio of isocyanate groups contained in the curing agent to the total of the hydroxy groups and carboxyl groups derived from the polyol component (A) and the silane coupling agent (B) containing 95-50% by weight [NCO]/([OH]+[COOH]) is 1-30.

In addition, any one (A) of one or more resins (A) selected from the group consisting of modified polypropylene and acrylic resins, or a coupling agent (B) containing at least one of a silane coupling agent and a titanate-based coupling agent Or the adhesive containing the resin containing (B) is also mentioned.

In addition, the adhesive layer 2 may contain a colorant. When the adhesive layer 2 contains a colorant, the battery packaging material can be colored. As the colorant, known ones such as pigments and dyes can be used. In addition, only one type of coloring agent may be used, and two or more types may be mixed and used.

For example, as a specific example of an inorganic pigment, Preferably, carbon black, titanium oxide, etc. are mentioned. Moreover, as a specific example of an organic pigment, Preferably, an azo pigment, a phthalocyanine pigment, a condensed polycyclic pigment etc. are mentioned. Examples of azo pigments include soluble pigments such as watching red and carmine 6C; Insoluble azo pigments such as monoazo yellow, disazo yellow, pyrazolone orange, pyrazolone red, and permanent red may be mentioned. As the phthalocyanine pigment, a blue pigment or a green pigment as a copper phthalocyanine pigment and a metal-free phthalocyanine pigment may be used. Examples of condensed polycyclic pigments include dioxazine violet and quinacridone violet. Moreover, as a pigment, a pearl pigment, a fluorescent pigment, etc. can also be used.

Among the colorants, for example, in order to make the appearance of the battery packaging material black, carbon black is preferable.

The average particle diameter of the pigment is not particularly limited, for example, about 0.05 to 5 µm, preferably about 0.08 to 2 µm. In addition, the average particle diameter of a pigment is made into the median diameter measured by a laser diffraction/scattering type particle diameter distribution measuring apparatus.

The content of the pigment in the adhesive layer 2 is not particularly limited as long as the battery packaging material is colored, and for example, about 5 to 60% by mass is mentioned.

The thickness of the adhesive layer 2 is not particularly limited as long as it exhibits a function as an adhesive layer, but may be, for example, about 1 to 10 µm, preferably about 2 to 5 µm.

[Coloring layer]

The colored layer is a layer formed as necessary between the base layer 1 and the adhesive layer 2 (not shown). By forming the colored layer, the battery packaging material can be colored.

The colored layer can be formed, for example, by applying an ink containing a colorant to the surface of the base layer 1 or the surface of the barrier layer 3. As the colorant, known ones such as pigments and dyes can be used. In addition, only one type of coloring agent may be used, and two or more types may be mixed and used.

As a specific example of the colorant contained in the colored layer, the same thing as exemplified in the column of [adhesive layer (2)] is illustrated.

[Barrier layer (3)]

In the battery packaging material, the barrier layer 3 is a layer having a function of preventing water vapor, oxygen, light, and the like from entering the inside of the battery in addition to improving the strength of the battery packaging material. The barrier layer 3 can be formed of a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film in which these vapor deposition layers are formed, or the like, and is preferably a layer formed of metal. Examples of the metal constituting the barrier layer 3 include aluminum, stainless steel, titanium steel, and the like, and preferably aluminum or stainless steel. The barrier layer 3 is preferably formed of a metal foil, and more preferably formed of an aluminum alloy foil or a stainless steel foil.

From the viewpoint of preventing wrinkles or pinholes from occurring in the barrier layer 3 during manufacture of the battery packaging material, the barrier layer is, for example, annealing-treated aluminum (JIS H4160:1994 A8021H-O, It is more preferable to form with a soft aluminum foil, such as JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O).

Further, examples of the stainless steel foil include austenitic stainless steel foil and ferritic stainless steel foil. The stainless steel foil is preferably made of an austenitic stainless steel.

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

The thickness of the barrier layer 3 is not particularly limited as long as it exhibits a function as a barrier layer such as water vapor, but from the viewpoint of thinning the thickness of the battery packaging material, the upper limit is preferably about 85 μm or less, more preferably About 50 μm or less, more preferably 45 μm or less may be mentioned, and the lower limit is preferably about 10 μm or more, and the range of the thickness is, for example, about 10 to 85 μm, preferably May be about 10 to 50 µm, more preferably about 10 to 45 µm. And, when the barrier layer 3 is made of stainless steel foil, the thickness of the stainless steel foil is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, furthermore Preferably, it is about 30 μm or less, particularly preferably about 25 μm or less, and the lower limit is about 10 μm or more, and the preferred thickness range is about 10 to 85 μm and about 10 to 50 μm. , More preferably, about 10 to 40 µm, more preferably about 10 to 30 µm, and still more preferably about 15 to 25 µm.

In addition, the barrier layer 3 is preferably subjected to chemical conversion treatment on at least one side, preferably both sides, in order to stabilize adhesion and prevent dissolution or corrosion. Here, the chemical conversion treatment refers to a treatment for forming an acid-resistant film on the surface of the barrier layer. When an acid-resistant film is formed on the surface of the barrier layer 3 of the present invention, an acid-resistant film is contained in the barrier layer 3. Examples of the chemical conversion treatment include chromic acid chromate treatment using a chromic acid compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium hydroxide, chromium bicarbonate, acetyl acetate, chromium chloride, and potassium chromium sulfate; Phosphoric acid chromate treatment using phosphoric acid compounds such as sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid; Chromate treatment using an aminated phenol polymer having a repeating unit represented by the following general formulas (1) to (4), and the like. In addition, in the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be included singly or in any combination of two or more.

In 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. In addition, R ¹ and R ² are the same or different, respectively, and represent 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 methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and isobutyl group. and a linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group. In addition, examples of the hydroxyalkyl group represented by X, R ¹ and R ² include hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, and 2-hydroxypropyl group. , 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group, and other hydroxy groups of 1 to 4 carbon atoms substituted Or a branched chain alkyl group is mentioned. In General Formulas (1) to (4), the alkyl group and hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different, respectively. In general formulas (1) to (4), it is preferable that X is a hydrogen atom, a hydroxy group, or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having repeating units represented by the general formulas (1) to (4) is, for example, preferably 5 to 1 million, more preferably 10 to 20,000.

In addition, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, a coating obtained by dispersing fine particles of a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide or barium sulfate in phosphoric acid is coated, and at least 150°C. A method of forming an acid-resistant film on the surface of the barrier layer 3 is exemplified by performing the baking treatment at. Further, on the acid-resistant film, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and carboxylic acid, a primary amine graft acrylic resin obtained by graft polymerization of a primary amine on an acrylic main skeleton, and polyallyl And amines, derivatives thereof, and aminophenols. As these cationic polymers, only one type may be used, or two or more types may be used in combination. Further, examples of the crosslinking agent include a compound having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. As these crosslinking agents, only one type may be used, or two or more types may be used in combination.

In addition, as a method of specifically forming the acid-resistant film, for example, at least the surface of the inner layer side of the aluminum foil (barrier layer) is first, alkali immersion method, electrolytic cleaning method, pickling method, electrolytic pickling method, acid activation. Degreasing treatment is performed by a known treatment method such as a method, and thereafter, phosphoric acid metal salts such as phosphate Cr (chromium) salt, phosphate Ti (titanium) salt, phosphate Zr (zirconium) salt, phosphate Zn (zinc) salt, etc. And a treatment liquid (aqueous solution) containing a mixture of these metal salts as a main component, or a treatment liquid (aqueous solution) containing a mixture of phosphate nonmetallic salts and a mixture of these nonmetallic salts as a main component, or an aqueous system such as acrylic resin, phenol resin, polyurethane, etc. An acid-resistant film can be formed by applying a treatment liquid (aqueous solution) made of a mixture with a synthetic resin by a known coating method such as a roll coating method, a gravure printing method, and an immersion method. For example, in the case of treatment with a Cr phosphate (chromium) salt-based treatment solution, CrPO ₄ (chromium phosphate), AlPO ₄ (aluminum phosphate), Al ₂ O ₃ (aluminum oxide), Al(OH) _x (aluminum hydroxide) , AlFx (aluminum fluoride), etc., and when treated with a Zn phosphate (zinc) salt-based treatment solution, Zn ₂ PO ₄ 4H ₂ O (zinc phosphate hydrate), AlPO ₄ (aluminum phosphate), Al ₂ It becomes an acid-resistant coating made of O ₃ (aluminum oxide), Al(OH) _x (aluminum hydroxide), AlF _x (aluminum fluoride), and the like.

In addition, as another example of a specific method for forming an acid-resistant film, for example, at least the surface of the inner layer side of the aluminum foil is first, known as an alkali immersion method, an electrolytic washing method, an acid washing method, an electrolytic acid washing method, an acid activation method, etc. An acid-resistant film can be formed by performing a degreasing treatment as a treatment method and then performing a known anodizing treatment on the degreasing treatment surface.

Further, as another example of the acid-resistant coating, a coating of a phosphorus compound (for example, a phosphate type) or a chromium compound (a chromic acid type) can be mentioned. As a phosphate type, zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, chromium phosphate, etc. are mentioned, As a chromic acid type, chromium chromate etc. are mentioned.

In addition, as another example of the acid-resistant coating, by forming an acid-resistant coating such as phosphate, chromate, fluoride, triazinethiol compound, etc., delamination between aluminum and the substrate layer during embossing is prevented, and in reaction by electrolyte and moisture. The generated hydrogen fluoride prevents the dissolution and corrosion of the aluminum surface, particularly the aluminum oxide present on the aluminum surface from being dissolved and corroded, and also improves the adhesion (wetting) of the aluminum surface, and improves the heat sealing. In the case of preventing delamination of the base layer and aluminum, and in the embossed type, the effect of preventing delamination between the base layer and aluminum during press formation is achieved. Among the substances forming the acid-resistant film, an aqueous solution composed of three components of a phenol resin, a chromium (III) fluoride compound, and phosphoric acid is applied to the aluminum surface, and the drying and baking treatment is good.

In addition, the acid-resistant coating includes a layer having cerium oxide, phosphoric acid or phosphate, an anionic polymer, and a crosslinking agent for crosslinking the anionic polymer, and the phosphoric acid or phosphate is based on 100 parts by mass of the cerium oxide, 1 to 100 parts by mass may be blended. It is preferable that the acid-resistant coating has a multilayer structure further including a layer having a cationic polymer and a crosslinking agent for crosslinking the cationic polymer.

Moreover, it is preferable that the said anionic polymer is a copolymer containing poly(meth)acrylic acid or its salt, or (meth)acrylic acid or its salt 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 among an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent.

Further, it is preferable that the phosphoric acid or phosphate is a condensed phosphoric acid or a condensed phosphate.

Chemical conversion treatment may be performed by only one type of chemical conversion treatment, or may be performed in combination of two or more types of chemical conversion treatment. In addition, these chemical conversion treatments may be performed using one type of compound alone, or may be performed using a combination of two or more types of compounds. Among the chemical conversion treatments, chromic acid chromate treatment, chromate treatment in which a chromic acid compound, a phosphoric acid compound, and an aminated phenol polymer are combined are preferable.

Specific examples of the acid-resistant coating include those containing at least one of a phosphorus compound (phosphate, etc.), a chromium compound (chromate), a fluoride, and a triazinethiol compound. Further, an acid-resistant coating containing a cerium compound is also preferable. As the cerium compound, cerium oxide is preferable.

Further, specific examples of the acid-resistant coating include a phosphate-based coating, a chromate-based coating, a fluoride-based coating, and a triazinethiol compound coating. As an acid-resistant coating, one type of these may be sufficient and a combination of multiple types may be sufficient as them. In addition, as the acid-resistant coating, after degreasing the chemical conversion treatment surface of the barrier layer, a treatment liquid made of a mixture of a metal phosphate salt and an aqueous synthetic resin, or a treatment liquid made of a mixture of a non-metallic phosphate and an aqueous synthetic resin may be used. .

In addition, the composition analysis of the acid-resistant film can be performed using, for example, a time-of-flight secondary ion mass spectrometry. By composition analysis with an acid-resistant film using time-of-flight secondary ion mass spectrometry, for example, at least one of secondary ions composed of Ce, P, and O (eg, Ce ₂ PO ₄ ⁺ , CePO ₄ ^-, etc. Species) or, for example, a peak derived from a secondary ion composed of Cr, P, and O (eg, at least one of CrPO ₂ ⁺ , CrPO ₄ ^−, etc.) is detected.

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

The thickness of the acid-resistant film is not particularly limited, but from the viewpoint of the cohesive strength of the film and the adhesion to the barrier layer or heat-fusible resin layer, preferably about 1 nm to 20 µm, more preferably about 1 to 100 nm, More preferably, about 1 to 50 nm is used. In addition, the thickness of the acid-resistant film can be measured by a combination of observation with a transmission electron microscope or observation with a transmission electron microscope, and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.

In chemical conversion treatment, after applying a solution containing a compound used to form an acid-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, or the like, the temperature of the barrier layer is 70 It is performed by heating so that it may become -200 degreeC. Further, before performing chemical conversion treatment on the barrier layer, the barrier layer may be previously 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. By performing the degreasing treatment in this way, it becomes possible to perform the chemical conversion treatment on the surface of the barrier layer more efficiently.

[Heat-Fusing Resin Layer (4)]

In the battery packaging material of the present invention, the heat-fusible resin layer 4 corresponds to the innermost layer, and is a layer in which the heat-fusible resin layers are thermally fused to each other when assembling the battery to seal the battery element.

The resin component used for the heat-fusible resin layer 4 is not particularly limited as a limit on what can be heat-sealed, but for example, polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin are used. Can be heard. That is, the resin constituting the heat-fusible resin layer 4 may or may not contain a polyolefin skeleton, and it is preferable that a polyolefin skeleton is included. The fact that the resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly relevant. For example, when the infrared spectroscopy measurement of a maleic anhydride modified polyolefin, wavenumber 1760cm ^-1 and near the wave number of 1780cm a maleic anhydride-derived peak is detected in the vicinity of ^-1. However, when the acid denaturation degree is low, the peak becomes small and may not 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; Polypropylenes such as homopolypropylene, block copolymers of polypropylene (eg, block copolymers of propylene and ethylene), and random copolymers of polypropylene (eg, random copolymers of propylene and ethylene); Terpolymers of ethylene-butene-propylene, and the like. Among these polyolefins, polyethylene and polypropylene are preferably mentioned.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, and isoprene. Moreover, as a cyclic monomer which is a constituent monomer of the said cyclic polyolefin, For example, cyclic alkenes, such as norbornene; Specifically, cyclic dienes, such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and novonadiene, etc. are mentioned. Among these polyolefins, cyclic alkenes are preferred, and norbornene is more preferred. Moreover, styrene can also be used as a constituent monomer.

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

The carboxylic acid-modified cyclic polyolefin refers to a part of the monomer constituting the cyclic polyolefin, by copolymerization in place of the α,β-unsaturated carboxylic acid or an anhydride thereof, or the α,β-unsaturated carboxylic acid or an anhydride thereof with respect to the cyclic polyolefin. It is a polymer obtained by block polymerization or graft polymerization. About the cyclic polyolefin modified with carboxylic acid, it is the same as above. In addition, the carboxylic acid used for modification is the same as that used for modification of the polyolefin.

Among these resin components, Preferably, it is a carboxylic acid-modified polyolefin; More preferably, a carboxylic acid-modified polypropylene is used.

The heat-fusible resin layer 4 may be formed of one type of resin component alone, or may be formed of a blend polymer obtained by combining two or more types of resin components. Further, the heat-fusible resin layer 4 may be formed of only one layer, but may be formed of two or more layers of the same or different resin components.

In the heat-fusible resin layer 4, a lubricant may be contained. Further, the lubricant present on the surface of the heat-fusible resin layer 4 may be one obtained by exuding the lubricant contained in the resin constituting the heat-fusible resin layer 4, or A lubricant may be applied to the surface. When the heat-fusible resin layer 4 contains a lubricant, the moldability of the battery packaging material can be improved. It does not specifically limit as a lubricant, A well-known lubricant can be used, For example, what was illustrated by the said base material layer 1, etc. are mentioned. Lubricants may be used singly or in combination of two or more. The amount of the lubricant present on the surface of the heat-fusible resin layer 4 is not particularly limited, and from the viewpoint of enhancing the moldability of the electronic packaging material, it is preferably about 10 to 50 mg/m 2, more preferably 15 to About 40mg/m2 is mentioned.

In addition, the thickness of the heat-fusible resin layer 4 is not particularly limited as long as it exhibits a function as a heat-fusible resin layer, but for example, about 100 µm or less, preferably about 85 µm or less, more preferably About 15 to 85 micrometers is mentioned. And, for example, when the thickness of the adhesive layer 5 to be described later is 10 μm or more, the thickness of the heat-fusible resin layer 4 is preferably about 85 μm or less, more preferably about 15 to 65 μm. For example, when the thickness of the adhesive layer 5 to be described later is less than 10 μm or when the adhesive layer 5 is not formed, 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 battery packaging material of the present invention, the adhesive layer 5 is a layer formed between them as necessary in order to firmly adhere the barrier layer 3 and the heat-fusible resin layer 4 therebetween.

The adhesive layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4 to each other. As the resin used for the formation of the adhesive layer 5, the adhesive mechanism, the kind of the adhesive component, and the like can be the same as those of the adhesive exemplified in the adhesive layer 2. In addition, as the resin used for the formation of the adhesive layer 5, polyolefins such as polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins exemplified in the heat-fusible resin layer 4 can also be used. From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, as the polyolefin, a carboxylic acid-modified polyolefin is preferable, and a carboxylic acid-modified polypropylene is particularly preferable. That is, the resin constituting the adhesive layer 5 may or may not contain a polyolefin skeleton, and it is preferable that a polyolefin skeleton is included. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method does not particularly matter. For example, when measuring the maleic anhydride-modified polyolefin in infrared spectroscopy, near wavenumber 1760cm ^-1 and 1780cm wave number of the maleic anhydride-derived peak is detected in the vicinity of ^-1. However, when the acid denaturation degree is low, the peak becomes small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

From the viewpoint of improving the adhesion between the barrier layer 3 (or the acid-resistant coating) and the heat-fusible resin layer 4, it is preferable that the adhesive layer 5 contains an acid-modified polyolefin. The acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of a polyolefin with an acid component such as carboxylic acid. Examples of the acid component used for denaturation include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or anhydrides thereof. Further, examples of the modified polyolefin include polyethylenes such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene; Polypropylenes such as homopolypropylene, a block copolymer of polypropylene (for example, a block copolymer of propylene and ethylene), and a random copolymer of polypropylene (for example, a random copolymer of propylene and ethylene); Terpolymers of ethylene-butene-propylene, and the like. Among these polyolefins, polyethylene and polypropylene are preferably mentioned.

In the adhesive layer 5, among the acid-modified polyolefins, maleic anhydride-modified polyolefin and further maleic anhydride-modified polypropylene are particularly preferred.

In addition, from the viewpoint of making the battery packaging material thinner and having excellent shape stability after molding, the adhesive layer 5 is more preferably a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. As the acid-modified polyolefin, preferably the above can be illustrated.

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

In addition, from the viewpoint of further enhancing the adhesion between the barrier layer 3 (or the acid-resistant coating), the heat-fusible resin layer 4 and the adhesive layer 5, the adhesive layer 5 is an oxygen atom, a heterocycle, a C=N bond, And a curing agent having at least one selected from the group consisting of COC bonds. Examples of the curing agent having a heterocycle include a curing agent having an oxazoline group and a curing agent having an epoxy group. Further, 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. Further, 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 adhesive layer 5 is a cured product of a resin composition containing these curing agents, for example, gas chromatography mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF-SIMS), It can be confirmed by methods such as X-ray photoelectron spectroscopy (XPS).

Although it does not specifically limit as a compound which has an isocyanate group, From a viewpoint of improving the adhesiveness of the acid-resistant film and the adhesive layer 5 effectively, Preferably a polyfunctional isocyanate compound is mentioned. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate curing agent include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymerizing them. Nurated, mixtures of these, copolymers with other polymers, and the like.

As the content of the compound having an isocyanate group in the adhesive layer 5, the resin composition constituting 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. desirable.

The compound having an oxazoline group is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the compound having an oxazoline group include those having a polystyrene main chain and an acrylic main chain. Moreover, as a commercial item, the Nippon Shokubai company Epocross series etc. are mentioned, for example.

As the proportion of the compound having an oxazoline group in the adhesive layer 5, the resin composition constituting the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and in the range of 0.5 to 40% by mass. More preferable. Thereby, the adhesion between the barrier layer 3 (or the acid-resistant coating) and the adhesive layer 5 can be effectively improved.

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. As a weight average molecular weight of an epoxy resin, Preferably it is about 50-2000, More preferably, about 100-1000, More preferably, about 200-800 is mentioned. In addition, in the present invention, the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC), measured under conditions using polystyrene as a standard sample.

Specific examples of the epoxy resin include trimethylolpropane glycidyl ether derivatives, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin poly And glycidyl ether. Epoxy resin may be used individually by 1 type, and may be used combining two or more types.

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 . Thereby, the adhesion between the barrier layer 3 (or the acid-resistant coating) and the adhesive layer 5 can be effectively improved.

And, in the present invention, when the adhesive layer (5) is a cured product of 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. , The acid-modified polyolefin functions as a main material, and the compound having an isocyanate group, the compound having an oxazoline group, and the epoxy resin function as a curing agent, respectively.

The carbodiimide 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 curing agent, a polycarbodiimide compound having at least two or more carbodiimide groups is preferable.

From the viewpoint of improving 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 types of 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 mass%, more preferably in the range of about 0.1 to 30 mass%, and 0.1 to 10 mass% It is more preferable to be in a range of degrees.

In addition, the adhesive layer 5 can also be preferably formed using, for example, an adhesive. As the adhesive, for example, an amorphous polyolefin resin (A) having a carboxyl group, a polyfunctional isocyanate compound (B), and a tertiary amine (C) having no functional group reacting with the polyfunctional isocyanate compound (B) are contained, , Polyfunctional isocyanate compound (B) is contained in a range in which the amount of isocyanate groups is 0.3 to 10 moles per 1 mole of the total carboxyl groups, and tertiary amine (C) is 1 to 10 moles per mole of the total carboxyl groups. The thing formed from the adhesive composition contained in the range of a mole is mentioned. In addition, as the adhesive, a styrene-based thermoplastic elastomer (A), a tackifier (B), and a polyisocyanate (C) are contained, and a total of 100 weights of the styrene-based thermoplastic elastomer (A) and the tackifier (B) In %, 20 to 90% by weight of the styrenic thermoplastic elastomer (A), 10 to 80% by weight of the tackifier (B), and 0.003 to 0.04 mmol/g of the styrenic thermoplastic elastomer (A) It has an active hydrogen derived from an amino group or a hydroxyl group of, and with respect to 1 mole of the active hydrogen derived from the styrene-based thermoplastic elastomer (A), the active hydrogen derived from the functional group of the tackifier (B) is 0 to 15 moles, Isocyanate (C) is contained in the range of 3 to 150 moles of isocyanate groups with respect to 1 mole of the total 1 mole of the active hydrogen derived from the styrene-based thermoplastic elastomer (A) and the active hydrogen derived from the tackifier (B). The thing formed by the adhesive composition which consists of a thing, etc. are also mentioned.

The thickness of the adhesive layer 5 is not particularly limited as long as it exhibits a function as an adhesive layer, but for example, about 50 μm or less, about 40 μm or less, preferably about 30 μm or less, more preferably about 20 μm or less, More preferably, about 5 μm or less can be mentioned, and the lower limit is about 0.1 μm or more, about 0.5 μm or more, and about 10 μm or more, and the range of the thickness is preferably about 0.1 to 50 μm. , About 0.1 to 40 μm, about 0.1 to 30 μm, about 0.1 to 20 μm, about 0.1 to 5 μm, about 0.5 to 50 μm, about 0.5 to 40 μm, about 0.5 to 30 μm, about 0.5 to 20 μm, 0.5 About -5 micrometers, about 10-50 micrometers, about 10-40 micrometers, about 10-30 micrometers, and about 10-20 micrometers are mentioned. More specifically, in the case of using the adhesive exemplified in the adhesive layer 2, it is preferably 2 to 10 µm, more preferably about 2 to 5 µm. In addition, when using the resin illustrated in the heat-fusible resin layer 4, it is preferably about 2 to 50 µm, more preferably about 10 to 40 µm. In addition, in the case of a cured product of an acid-modified polyolefin and a curing agent, 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 the adhesive layer formed from the above-described adhesive composition, the thickness after drying and curing may be about 1 to 30 g/m 2. And, 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 by heating or the like.

As described later, in the production of a laminate constituting the battery packaging material of the present invention, on the barrier layer 3, a method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 in this order As an example, a method of laminating on the barrier layer 3 by coextruding the adhesive layer 5 and the heat-fusible resin layer 4 can be adopted. That is, in the battery packaging material of the present invention, the adhesive layer and the heat-fusible resin layer can be a coextrusion laminate.

3. Manufacturing method of battery packaging material

The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate obtained by laminating each layer of a predetermined composition is obtained. The manufacturing method of the battery packaging material includes, for example, a step of laminating at least a base layer, a barrier layer, and a heat-fusible resin layer positioned on the outermost surface in this order to obtain a laminate, and the base layer The outermost surface of the polyester film layer is composed of a polyester film layer, and as a polyester film, by using a total reflection method of Fourier transform infrared spectroscopy, on the surface of the polyester film, from 0° to 180° by 10° When the infrared absorption spectrum in 18 directions is acquired, the maximum value of the ratio of the absorption peak intensity Y _{1340 at 1340} cm ^-1 of this infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at ₁₄₁₀ cm ^-1 (Y ₁₃₄₀ / Y ₁₄₁₀ ) A method using a ratio of Y _max and minimum value Y _min (surface orientation degree: Y _max /Y _min ) of less than 1.4 is mentioned.

As an example of the manufacturing method of the battery packaging material of this invention, it is as follows. First, a laminate in which the base layer 1, the adhesive layer 2, and the barrier layer 3 are sequentially stacked (hereinafter, also referred to as "laminate A") is formed. In the formation of the laminate A, specifically, an adhesive used for formation of the adhesive layer 2 on the substrate layer 1 or on the barrier layer 3 whose surface has been chemically converted as needed, is applied by a gravure coating method or a roll. After coating and drying by a coating method such as a coating method, the barrier layer 3 or the base layer 1 may be laminated to cure the adhesive layer 2 by a dry lamination method.

Next, on the barrier layer 3 of the laminate A, the adhesive layer 5 and the heat-fusible resin layer 4 are laminated in this order. For example, (1) a method of laminating by coextrusion of the adhesive layer 5 and the heat-fusible resin layer 4 on the barrier layer 3 of the laminate A (co-extrusion lamination method), (2) separately , A method of forming a laminate in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated, and laminating this on the barrier layer 3 of the laminate A by a thermal lamination method, (3) laminate A On the barrier layer 3 of, an adhesive for forming the adhesive layer 5 is laminated by extrusion method or solution coating, drying at high temperature, baking, etc., and previously formed into a sheet form on the adhesive layer 5 A method of laminating the heat-fusible resin layer 4 by the thermal lamination method, (4) melting between the barrier layer 3 of the laminate A and the heat-fusible resin layer 4 previously formed into a sheet shape. A method of bonding the layered product A and the heat-fusible resin layer 4 through the adhesive layer 5 while being put along the adhesive layer 5 (sandwich lamination method), and the like.

As described above, the base layer (1) / the adhesive layer (2) formed as needed / the barrier layer (3) with the surface chemically treated as necessary (3) / the adhesive layer (5) / heat-fusible resin layer (4) A laminate made of is formed, but in order to make the adhesiveness of the adhesive layer 2 or the adhesive layer 5 strong, it may be further subjected to a heat treatment such as a hot roll contact type, a hot air type, a near infrared ray type, or a far infrared ray type. Conditions for such heat treatment include, for example, about 1 to 5 minutes at about 150 to 250°C.

In the battery packaging material of the present invention, each layer constituting the laminate is, if necessary, to improve or stabilize film forming properties, lamination processing, secondary processing of the final product (pouching, embossing), etc. , Corona treatment, blast treatment, oxidation treatment, ozone treatment, or other surface activation treatment may be performed.

4. Use of battery packaging materials

The battery packaging material of the present invention is used in a package for sealing and accommodating battery elements such as a positive electrode, a negative electrode, and an electrolyte. That is, a battery element provided with at least a positive electrode, a negative electrode, and an electrolyte can be accommodated in a package body formed of the battery packaging material of the present invention to obtain a battery. The battery packaging material of the present invention is suitably used for applications in which printing is performed on the surface of the polyester film layer located on the outermost surface.

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is used as the battery packaging material of the present invention, with the metal terminals connected to each of the positive electrode and the negative electrode protruding outward, and the peripheral edge of the battery element A battery using a battery packaging material is provided by covering the flange portion (a region in which the heat-fusible resin layers contact each other) to be formed on the flange portion, and sealing the heat-sealing resin layers of the flange portion by heat sealing. . And, when the battery element is accommodated in the package formed by the battery packaging material of the present invention, the heat-fusible resin portion of the battery packaging material of the present invention is made inside (the surface in contact with the battery element) to form the package. do. The infrared absorption spectrum and the arithmetic mean roughness Ra on the surface of the polyester film layer can be measured by obtaining a battery packaging material from a battery and measuring the polyester film layer of the obtained battery packaging material. However, the measurement of the infrared absorption spectrum and the arithmetic mean roughness Ra of the battery packaging material obtained from the battery is different from that of the peripheral edge flange (part where heat-fusible resin layers are heat-sealed) or the side part of the battery, respectively. The battery packaging material of the part (preferably the top or bottom surface of the battery) is negatively defined.

In the present invention, in at least one of a receiving step of accommodating a battery element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed of the battery packaging material of the present invention, and before and after the receiving step, A battery in which printing has been performed on the surface of the polyester film layer can be manufactured by a method including a step of performing printing on the surface of the polyester film layer located on the outermost surface. That is, the battery of the present invention can be a battery having a printing portion on its surface. The printing part is a part in which barcodes, patterns, characters, symbols, etc. formed on the surface of the battery are printed.

In the battery packaging material of the present invention, when evaluation of the printing aptitude on the surface of the polyethylene terephthalate film is performed under the following conditions, the radius of the dot forming the printing portion is preferably 130 µm or more, 135 µm or more, and 140 It is preferable to be equal to or greater than µm, and equal to or less than 151 µm and equal to or less than 149 µm, and preferred ranges of the radius include approximately 130 to 151 µm, approximately 130 to 149 µm, approximately 135 to 151 µm, approximately 135 to 149 µm, and 140 About -151 micrometers and about 140-149 micrometers are mentioned. When the radius of the dot satisfies such a value, it can be evaluated as excellent in printing aptitude. Specifically, printing of barcodes, patterns, characters, symbols, etc. is formed by an aggregate of ink dots, and if the radius of the dot forming the printing portion satisfies the above value, the radius of the dot is too small or too large, or It is not done, and desired printing can be performed appropriately.

In addition, in the battery packaging material of the present invention, when evaluation of printing suitability on the surface of a polyethylene terephthalate film is performed under the following conditions, it is preferable that the circularity of the dots forming the printing portion is 0.725 or more. The closer the circularity of the printing portion is to 1, the better the printability can be evaluated. Specifically, for printing of barcodes, patterns, characters, symbols, etc., if the circularity of the dots forming the printing portion satisfies the above values, the shape of the dots is not distorted, and desired printing can be performed appropriately.

<Evaluation of printing aptitude on the surface of polyethylene terephthalate film>

In an environment of a temperature of 24°C and a relative humidity of 50%, on the surface of the polyethylene terephthalate film of each battery packaging material prepared above, an inkjet printer (9040 (1.1M head) manufactured by Markem Image Co., Ltd.) was used. Ink is dripped and dried for 10 seconds. Next, the printing aptitude of the polyethylene terephthalate film surface is evaluated based on the radius and circularity of the dots of the printing portion formed on the surface of the polyethylene terephthalate film. The printing conditions were set as ink viscosity: 3.4 cps, temperature: 34°C, pressure: 270 bar, nozzle size: 50 μm in diameter, and resolution (dot density): 115 dpi. The method of negatively determining the radius and circularity of the dots of the printing portion is as described later. The evaluation is performed in the state of the battery packaging material. Incidentally, the radius and circularity of the dots of the printing portion are taken as the average value of N number 3. And in performing the evaluation, operations such as wiping the surface of the polyethylene terephthalate film are not performed.

The distance between the print head of the inkjet printer and the surface of the polyethylene terephthalate film is 20 mm, and 5157E standard ink is used as the ink.

In addition, for observation of the radius and circularity of the dots of the printed portion formed on the surface of the polyethylene terephthalate film, a laser microscope (for example, a laser microscope VK-9710 manufactured by KEYENCE) is used, and the magnification is 10 times.

(How to determine the radius of the dot in the print section)

Image analysis software (for example, analysis software VK Analyzer Ver2.4.0.0 manufactured by KEYENCE) was used for the image observed with the above laser microscope for the shape of the dot of the printing portion dropped on the surface of each polyethylene terephthalate film. Then, by analysis using a three-point circle, the radius of a circle passing through three points (= the radius of the dot of the printing portion) is obtained.

(Evaluation of the circularity of the dots in the printed area)

The circularity of the dots of the printing portion formed by the ink dropped on the surface of each polyethylene terephthalate film is negatively determined using image analysis software (for example, image analysis software WinROOF (Ver6.6.0) manufactured by Shoji Mitani). Then, it analyzes as a target a figure connecting the center points of the boundary pixels constituting the outline of the dot. In the analysis screen of WinRoof, it is a value indicated by circularity II. And the circularity of the dot of the printing part is calculated by the following formula.

The circularity of the dots of the printing area = 4π × (area of dots)/(circumference of dots) ²

The battery packaging material of the present invention may be used for either a primary battery or a secondary battery, but is preferably a secondary battery. The type of secondary battery to which the battery packaging material of the present invention is applied is not particularly limited, and examples include lithium ion batteries, lithium ion polymer batteries, lead acid batteries, nickel-hydrogen storage batteries, nickel-cadmium storage batteries, nickel-iron Storage batteries, nickel/zinc storage batteries, silver oxide/zinc storage batteries, metal air batteries, polyvalent cation batteries, capacitors, capacitors, and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are mentioned as suitable targets for application of the battery packaging material of the present invention.

5. Polyester film

The polyester film of the present invention is a polyester film used for use in a polyester film layer positioned on the outermost surface of a battery packaging material. The polyester film of the present invention uses the total reflection method of Fourier transform infrared spectroscopy to obtain an infrared absorption spectrum in 18 directions from 0° to 170° in increments of 10° with respect to the surface of the polyester film, Y _max /Y _min <1.4. The specific configuration (composition, thickness, etc.) of the polyester film of the present invention is described in "2. Each layer forming a battery packaging material" WHEREIN: It is the same as the polyester film of the polyester film layer which comprises the outermost surface. In addition, the measurement of the infrared absorption spectrum on the surface of the polyester film can be performed in the state of only the polyester film with respect to the surface serving as the outermost surface side of the battery packaging material. Further, the measurement of the arithmetic average roughness Ra of the polyester film can also be performed in the state of only the polyester film with respect to the surface serving as the outermost surface side of the battery packaging material.

<Example>

The present invention will be described in detail by presenting examples and comparative examples below. However, the present invention is not limited to the examples.

<Manufacture of battery packaging materials>

Each battery packaging material of Examples 1 to 3 and Comparative Examples 1 to 7 was manufactured by the following method.

(Example 1)

An aluminum foil (JIS H4160:1994) in which an acid-resistant coating was formed on both sides of a biaxially-stretched polyethylene terephthalate film (thickness 25 μm, surface orientation of Table 1: Y _max /Y _min and arithmetic average roughness Ra) as a base layer. A8021H-O, a thickness of 40 µm) was laminated by a dry lamination method. Specifically, a two-liquid curable urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of the aluminum foil, and an adhesive layer (thickness 3 μm) was formed on the aluminum foil having an acid-resistant coating formed on both sides. Next, after laminating an adhesive layer on an aluminum foil and a biaxially stretched polyethylene terephthalate film, an aging treatment was performed to prepare a laminate of a base material layer/adhesive layer/barrier layer. In addition, the chemical conversion treatment of forming the acid-resistant film of the aluminum foil used as the barrier layer was carried out in a roll coating method such that a treatment solution consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid was applied to a chromium amount of 10 mg/m 2 (dry mass) It applied to both surfaces of an aluminum foil by this, and performed by baking. And the aluminum foil used as a barrier layer has an acid-resistant coating containing chromium oxide and phosphate.

Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (25 µm in thickness) as an adhesive layer and random polypropylene (55 µm in thickness) as a heat-sealable resin layer were coextruded on the barrier layer by coextrusion. The heat-fusible resin layer was laminated. Next, the obtained laminate was aged and heated to obtain a battery packaging material in which a substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer with an acid-resistant coating on both sides were laminated in this order.

The analysis of the acid-resistant coating was performed as follows. First, the barrier layer and the adhesive layer were separated. At this time, it was physically peeled off without using water, an organic solvent, or an aqueous solution of an acid or an alkali. After peeling between the barrier layer and the adhesive layer, since the adhesive layer remained on the surface of the barrier layer, the remaining adhesive layer was removed by etching with Ar-GCIB. With respect to the surface of the barrier layer thus obtained, the acid-resistant coating was analyzed using a time-of-flight secondary ion mass spectrometry. As a result, secondary ions composed of Ce and P and O such as Ce ₂ PO ₄ ⁺ and CePO ₄ ⁻ were detected from the acid-resistant coating. The details of the measurement device and measurement conditions of the time-of-flight secondary ion mass spectrometry are as follows.

Measurement device: Time-of-flight secondary ion mass spectrometer TOF manufactured by ION-TOF. SIMS5

Measuring conditions

Primary ions: double charged ions of bismuth clusters (Bi ₃ ⁺⁺ )

Primary ion acceleration voltage: 30kV

Mass range (m/z): 0 to 1500

Measurement range: 100㎛×100㎛

Number of scans: 16 scan/cycle

Number of pixels (one side): 256 pixels

Etching ions: Ar gas cluster ion beam (Ar-GCIB)

Etch ion acceleration voltage: 5.0 kV

(Example 2)

On the surface of a biaxially stretched polyethylene terephthalate film (thickness 25 μm, surface orientation in Table 1: Y _max / Y _min and arithmetic mean roughness Ra), a lubricant (erucic acid amide (applied amount is 6 mg/m 2 )) and poly A battery packaging material was obtained in the same manner as in Example 1 except that ether-modified silicone oil (application amount is 1 mg/m 2 )) was applied (application amount was 7 mg/m 2 in total).

(Example 3)

As the base layer, a biaxially stretched polyethylene terephthalate film (thickness 12 µm, surface orientation in Table 1: Y _max /Y _min and arithmetic mean roughness Ra) and a biaxially oriented nylon film (thickness 15 µm) were dry laminated. The laminated film laminated by was prepared. In this laminated film, between the biaxially stretched polyethylene terephthalate film and the biaxially stretched nylon film, a urethane adhesive (thickness after curing of 3 µm) using a polyol and an isocyanate curing agent is bonded to each other. Next, on the side of the biaxially stretched nylon film, a barrier layer composed of aluminum foil (JIS H4160:1994 A8021H-O, thickness 40 μm) with an acid-resistant coating was laminated by performing chemical conversion treatment on both sides by a dry lamination method. Made it. Specifically, a two-component polyurethane-based adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of an aluminum foil provided with an acid-resistant film, and an adhesive layer (thickness 3 μm) was formed on the aluminum foil. Next, after laminating the adhesive layer on the aluminum foil and the biaxially stretched nylon film side of the base layer, by performing an aging treatment, the base layer (biaxially stretched polyethylene terephthalate film / adhesive / biaxially stretched nylon film) / adhesive A laminate of a barrier layer provided with an acid-resistant coating on both sides/layer was produced. And the aluminum foil used as a barrier layer has an acid-resistant film containing chromium oxide and phosphate on both surfaces. The analysis of the acid-resistant film on the barrier layer was performed using a time-of-flight secondary ion mass spectrometry method in the same manner as in Example 1. As a result, secondary ions composed of Cr, P and O, such as CrPO ₂ ⁺ and CrPO ₄ ^- , were detected from the acid-resistant coating.

Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (thickness 40 µm) as an adhesive layer and random polypropylene (thickness 40 µm) as a heat-sealable resin layer were coextruded on the barrier layer. /The heat-fusible resin layer was laminated. Next, the obtained laminate was aged and heated to obtain a battery packaging material in which a substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

(Comparative Example 1)

As the biaxially stretched polyethylene terephthalate film of the base layer, a battery packaging material was obtained in the same manner as in Example 3, except that one having a surface orientation degree: Y _max /Y _min and arithmetic average roughness Ra shown in Table 1 was used.

(Comparative Example 2)

A polyethylene terephthalate film and a nylon film were laminated by coextrusion, and a laminated film biaxially stretched was prepared. Biaxially stretched polyethylene terephthalate film (thickness 5㎛, surface orientation of Table 1: Y _max /Y _min and arithmetic mean roughness Ra) and biaxially stretched nylon film (thickness 20㎛) of the laminated film constituting the base layer ), there is an adhesive layer (thickness of 1 µm) made of polyester (polyester elastomer). In the laminated film, a biaxially stretched polyethylene terephthalate film/adhesive/bis-axially stretched nylon film is sequentially laminated. Next, the surface of the biaxially stretched nylon film side was subjected to chemical conversion treatment on both sides, and a barrier layer composed of an aluminum foil (JIS H4160:1994 A8021H-O, thickness 40 μm) with an acid-resistant coating was dry-laminated. Laminated by Specifically, a two-component polyurethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of an aluminum foil provided with an acid-resistant film to form an adhesive layer (thickness of 3 μm). Subsequently, after laminating the adhesive layer on the barrier layer with the acid-resistant film and the biaxially stretched nylon film side of the base layer, an aging treatment is performed, whereby the base layer (biaxially stretched polyethylene terephthalate film/adhesive/two-axis stretching Nylon film)/adhesive layer/barrier layer laminated with acid-resistant coatings on both sides was prepared.

Next, an amorphous polyolefin resin having a carboxyl group and an adhesive made of a polyfunctional isocyanate compound (thickness after curing of 2 μm) were applied, dried at 100° C., and the barrier layer side of the obtained laminate and non-stretched polypropylene A film (CPP, thickness of 80 µm) was passed between two rolls set at 60° C. and adhered to thereby laminate an adhesive layer/heat-fusible resin layer on the barrier layer. Next, by performing the aging treatment, the base layer (biaxially stretched polyethylene terephthalate film/adhesive/2-axis stretched nylon film)/adhesive layer/barrier layer/adhesive layer/unstretched polypropylene film is laminated in this order. Got the ingredients.

(Comparative Example 3)

As the biaxially stretched polyethylene terephthalate film of the base layer, a battery packaging material was obtained in the same manner as in Example 3, except that one having a surface orientation degree: Y _max /Y _min and arithmetic average roughness Ra shown in Table 1 was used.

(Comparative Example 4)

As the biaxially stretched polyethylene terephthalate film of the base layer, a battery packaging material was obtained in the same manner as in Example 3, except that one having a surface orientation degree: Y _max /Y _min and arithmetic average roughness Ra shown in Table 1 was used.

(Comparative Example 5)

As the biaxially stretched polyethylene terephthalate film of the substrate layer, a battery packaging material was obtained in the same manner as in Example 3, except that one having a surface orientation degree: Y _max /Y _min and arithmetic average roughness Ra shown in Table 1 was used.

(Comparative Example 6)

A lubricant (erucic acid amide) was applied to the surface of a biaxially stretched polyethylene terephthalate film (thickness 25 μm, surface orientation in Table 1: Y _max /Y _min and arithmetic average roughness Ra) (application amount is 7 mg/ Except for m2), it carried out similarly to Comparative Example 2, and obtained the battery packaging material.

(Comparative Example 7)

A lubricant (erucic acid amide) was applied to the surface of a biaxially stretched polyethylene terephthalate film (thickness 25 μm, surface orientation degree in Table 1: Y _max /Y _min and arithmetic average roughness Ra) (application amount is 10 mg/ Except for m2), it carried out similarly to Comparative Example 2, and obtained the battery packaging material.

<Measurement of surface orientation>

With respect to the biaxially stretched polyethylene terephthalate film surface (the surface opposite to the barrier layer) of each of the battery packaging materials produced above, using a total reflection method (ATR) of Fourier transform infrared spectroscopy (FT-IR), respectively, from 0 ° to 170 ° obtaining the infrared absorption spectrum of a 10 by 18 ° direction, and 18 Y in the absorption peak intensity at the wavenumber 1340cm ^-1 in the infrared absorption spectrum ₁₃₄₀ for the direction (CH ₂ vertical vibration) and a wavenumber 1410cm ^- from the value of the absorption peak intensity at ¹ Y ₁₄₁₀ (C = C stretching vibration) calculating a Y ₁₃₄₀ / Y _1410, respectively, from the maximum value Y _max and the minimum value Y _min of them, the surface orientation degree: calculated Y _max / Y _min I did. The specific measurement conditions of the infrared absorption spectrum are as follows. Table 1 shows the results.

And, for Example 2, Comparative Example 6, and Comparative Example 7, the lubricant on the surface of the biaxially stretched polyethylene terephthalate film was wiped off with 2-butanone, and the surface orientation was measured with respect to the surface of the biaxially stretched polyethylene terephthalate film. I did.

(Infrared absorption spectrum measurement conditions)

Spectrometer: Nicolet iS10 FT-IR from Thermo Fisher Scientific

Attachment: Single reflection ATR reflection attachment (Seagull)

Detector: MCT (Hg Cd Te)

Wavenumber resolution: 8cm ^-1

Total number of times: 128

IRE: Ge

Incidence angle: 30°

Polarizer: wire grid, S polarization

Baseline: Average value of intensity in the range of wavenumber 1800-2000cm ^-1

The absorption peak intensity at the wavenumber 1340cm ^-1 Y _1340: wave number ^-1 1335~1342cm minus the value of the base line from the maximum value of the peak intensity in the range of

The absorption peak intensity at the wavenumber 1410cm ^-1 Y _1410: a value obtained by subtracting the value of the base line from the maximum value of the peak intensity in the range of wave number 1400~1410cm ^-1

The acquisition of the infrared absorption spectrum in the 18 directions was performed by placing the sample to which the polyester film was exposed horizontally on a sample holder and rotating by 10° for each Ge crystal placed on the sample. The angle of incidence is the angle between the perpendicular (normal) and incident light.

<Measurement of arithmetic mean roughness Ra of the surface of a polyethylene terephthalate film>

In accordance with the method specified in JIS B 0601-2001, the arithmetic average roughness Ra is measured for the surface of the biaxially stretched polyethylene terephthalate film (polyester film layer) constituting the outermost surface of each battery packaging material obtained above. I did. As a measuring apparatus for arithmetic mean roughness Ra, a white interferometer NewView 7300 manufactured by Zygo was used, and measurement was performed under conditions of a measurement area of 0.22 mm (50 times the objective lens and 1 time zoom lens) and with tilt correction (Cylinder). . The arithmetic mean roughness Ra was measured in the state of a battery packaging material. And during the measurement, operations such as wiping the surface of the polyethylene terephthalate film are not performed. Table 1 shows the results.

<Evaluation of printing aptitude on the surface of polyethylene terephthalate film>

On the surface of the biaxially stretched polyethylene terephthalate film of each battery packaging material produced above in an environment of a temperature of 24°C and a relative humidity of 50%, an inkjet printing machine (9040 (1.1M head) manufactured by Markem-Imaji Co., Ltd.) Ink was dripped using, and dried for 10 seconds. Next, the printing aptitude of the surface of the biaxially stretched polyethylene terephthalate film was evaluated based on the radius and circularity of the dots of the printing portion formed on the surface of the biaxially stretched polyethylene terephthalate film. The printing conditions were set to be ink viscosity: 3.4 cps, temperature: 34°C, pressure: 270 bar, nozzle size: 50 μm in diameter, and resolution (dot density): 115 dpi. The method of measuring the radius and circularity of the dots of the printing portion is as described later. The evaluation was carried out in the state of the battery packaging material. In addition, the radius and circularity of the dots of the printing part were made into the average value of N number 3. And when performing the evaluation, operations such as wiping the surface of the polyethylene terephthalate film are not performed. Table 1 shows the results.

The distance between the inkjet printer print head and the surface of the biaxially stretched polyethylene terephthalate film was 20 mm, and 5157E standard ink was used as the ink.

In addition, a laser microscope (laser microscope VK-9710 manufactured by KEYENCE) was used to observe the radius and circularity of the dots of the printed portion formed on the surface of the biaxially stretched polyethylene terephthalate film, and the magnification was 10 times. For reference, with respect to Example 2 and Comparative Example 7, the images of the printing portions formed on the surface of the biaxially stretched polyethylene terephthalate film observed with a laser microscope were respectively shown in Figs. 4 (Example 2) and 5 (Comparative Example 7). Shown in

(Method of measuring the radius of the dot of the print part)

With respect to the image observed with the above laser microscope, the shape of the dot of the printing portion dropped on the surface of each biaxially stretched polyethylene terephthalate film was analyzed using KEYENCE's analysis software VK Analyzer Ver2.4.0.0 using a three-point source. By analysis, the radius of a circle passing through three points (= radius of the dot of the print portion) was obtained. Table 1 shows the results.

(Evaluation of the circularity of the dots in the printed area)

The circularity of the dot of the printing part formed by the ink dripped on the surface of each biaxially stretched polyethylene terephthalate film was measured using the image analysis software WinROOF (Ver6.6.0) manufactured by Shoji Mitani. In addition, the analysis was performed on a figure connecting the center points of the boundary pixels constituting the outline of the dot. In the analysis screen of WinRoof, it is a value indicated by circularity II. And the circularity of the dot of the printing part is calculated by the following formula. The circularity of the dots of the printed part was evaluated according to the following criteria. Table 1 shows the results. For reference, for Example 2 (FIG. 4) and Comparative Example 7 (FIG. 5), actual measured values of the circularity of the dots of the printing portion are shown in Table 1.

The circularity of the dots of the printing area = 4π × (area of dots)/(circumference of dots) ²

A: The circularity of the dots in the printing area is 0.725 or more, and on the surface of the biaxially stretched polyethylene terephthalate film, the dots in the printing area have a neat circle.

B: The circularity of the dots in the printing area is 0.700 or more and less than 0.725, and on the surface of the biaxially stretched polyethylene terephthalate film, the dots in the printing area have a crushed circle.

[Table 1]

In the battery packaging materials of Examples 1 to 3, the polyester film layer constituting the outermost surface satisfies the relationship of the formula: Y _max /Y _min <1.4, the radius of the dot in the printing portion is small, and the printing portion The evaluation of the circularity of the dot is also excellent, and the printing aptitude is excellent. From the results of Examples 1 to 3, it can be seen that excellent printing aptitude is exhibited regardless of whether a lubricant is present on the surface of the polyester layer. On the other hand, in the battery packaging materials of Comparative Examples 1 to 7, the polyester film layer constituting the outermost surface does not satisfy the relationship of the formula: Y _max /Y _min <1.4, and the radius of the dot in the printing portion is large or Or, evaluation of the circularity of the dot of the printing part was inferior. For example, in Comparative Example 7, although the radius of the dot in the printing area was small, the circularity was as small as 0.723, and on the surface of the polyethylene terephthalate film layer, the dot in the printing area had a crushed circle, and printing aptitude was inferior ( 5). In Comparative Example 6, a lubricant was present on the surface of the polyester layer, and the radius of the dot in the printing portion was about the same as in Comparative Example 2, but the radius of the dot in the printing portion was larger than in Examples 1 to 3, and printing aptitude was inferior. . In addition, in Comparative Example 7, in which the amount of lubricant was increased from Comparative Example 6, the radius of the dots in the printing portion was small as described above, but the dots in the printing portion had a crushed circle, and printing suitability was inferior.

1: base layer
2: adhesive layer
3: barrier layer
4: heat-fusible resin layer
5: adhesive layer

Claims (18)

At least, it is composed of a laminate comprising a substrate layer, a barrier layer, and a heat-fusible resin layer located on the outermost surface in this order,
The outermost surface of the substrate layer is composed of a polyester film layer,
Battery packaging that satisfies the following equation when obtaining an infrared absorption spectrum in 18 directions in increments of 10° from 0° to 170° with respect to the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy material:
Y _max /Y _min <1.4
In the above formula, Y _max is a value obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. Is the maximum value,
Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. The method of claim 1,
A battery packaging material used for a purpose in which printing is performed on the surface of the polyester film layer. The method according to claim 1 or 2,
A battery packaging material having an arithmetic mean roughness Ra of 10 nm or more measured on the surface of the polyester film layer in accordance with the method specified in JIS B 0601-2001. The method according to any one of claims 1 to 3,
An adhesive layer is provided between the barrier layer and the heat-fusible resin layer,
The battery packaging material, wherein the adhesive layer contains an acid-modified polyolefin. The method of claim 4,
The acid-modified polyolefin of the adhesive layer is maleic anhydride-modified polypropylene,
The battery packaging material, wherein the heat-fusible resin layer contains polypropylene. The method according to claim 4 or 5,
The battery packaging material, wherein the adhesive layer has a thickness of 50 μm or less. The method according to claim 4 or 5,
The battery packaging material, wherein the adhesive layer has a thickness of 10 µm or more and 50 µm or less. The method according to any one of claims 4 to 7,
A battery packaging material, which is a coextruded laminate of the adhesive layer and the heat-fusible resin layer. The method according to any one of claims 1 to 8,
The battery packaging material, wherein the polyester film layer has a thickness of 10 μm or more and 50 μm or less. The method according to any one of claims 1 to 9,
An acid-resistant coating is provided on at least one surface of the barrier layer,
With respect to the acid-resistant film, the time-of-flight when analyzed using a secondary ion mass spectrometry, Ce ₂ PO ₄ ^+, CePO ₄ ^- at least one member selected from the group consisting of ^-, CrPO ₂ ^+, and CrPO ₄ A battery packaging material in which the derived peak is detected. The method according to any one of claims 1 to 10,
A battery packaging material comprising, on at least one surface of the barrier layer, an acid-resistant coating comprising at least one selected from the group consisting of phosphorus compounds, chromium compounds, fluorides, and triazinethiol compounds. The method according to any one of claims 1 to 11,
A battery packaging material comprising an acid-resistant coating containing a cerium compound on at least one surface of the barrier layer. The method according to any one of claims 1 to 12,
A battery packaging material in which a lubricant is present in at least one of the inside and the surface of the polyester film layer. At least, it includes a step of laminating a substrate layer, a barrier layer, and a heat-fusible resin layer positioned on the outermost surface in this order to obtain a laminate,
The outermost surface of the substrate layer is composed of a polyester film layer,
Battery packaging that satisfies the following equation when obtaining an infrared absorption spectrum in 18 directions in increments of 10° from 0° to 170° with respect to the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy How to make the material:
Y _max /Y _min <1.4
In the above formula, Y _max is a value obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. Is the maximum value,
Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. A battery, wherein a battery element provided with at least a positive electrode, a negative electrode, and an electrolyte is accommodated in a package formed of the battery packaging material according to any one of claims 1 to 13. The method of claim 15,
A battery having a printing portion on the surface of the polyester film layer. An accommodation step of accommodating a battery element provided with at least a positive electrode, a negative electrode, and an electrolyte in a package made of the battery packaging material according to any one of claims 1 to 13; And
Step of performing printing on the surface of the polyester film layer in at least one of before and after the receiving step
Containing, the method of manufacturing a battery. As a polyester film for use in a polyester film layer positioned on the outermost surface of a battery packaging material,
A polyester film that satisfies the following formula when obtaining an infrared absorption spectrum of 18 directions in increments of 10° from 0° to 170° for the surface of the polyester film by using the total reflection method of Fourier transform infrared spectroscopy. :
Y _max /Y _min <1.4
In the above formula, Y _max is a value obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions. Is the maximum value,
Y _min is the minimum of values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number ₁₃₄₀ cm ^-1 of the infrared absorption spectrum and the absorption peak intensity Y ₁₄₁₀ at the wave number ₁₄₁₀ cm ^-1 in each of the 18 directions.

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