JPWO2019112020A1 - Battery packaging material, battery, manufacturing method thereof, and polyester film - Google Patents

Abstract

At least, a substrate layer positioned on the outermost surface, a barrier layer, and a heat-fusible resin layer, which is composed of a laminate including in this order, the outermost surface of the substrate layer is configured by a polyester film layer. When the infrared reflection spectrum in 18 directions is acquired from 0 ° to 170 ° in steps of 10 ° from the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy, the following formula is satisfied. , Packaging materials for batteries. Ymax / Ymin <1.4

Description

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

  Conventionally, various types of batteries have been developed. In any battery, a packaging material is an indispensable member for sealing battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been frequently used as battery packaging.

  On the other hand, in recent years, with the improvement in performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes, and are also required to be thinner and lighter. However, metal battery packaging materials that have been widely used in the past have the disadvantages that it is difficult to follow the diversification of shapes and 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 be reduced in thickness and weight, a film-like laminate in which a base material / barrier layer / heat-sealable resin layer are sequentially laminated. Has been proposed (see, for example, Patent Document 1). In such battery packaging materials, generally, recesses are formed by cold forming, and battery elements such as electrodes and electrolytes are arranged in the spaces formed by the recesses, and the heat-fusible resin layers Is heat-sealed to obtain a battery in which the battery element is accommodated in the battery packaging material.

  In various packaging materials composed of the laminates as described above, ink is printed on the surface of the base material layer to form barcodes, patterns, characters, etc., and adhered onto the base material layer on the printed side A method of printing on a packaging material (generally referred to as back printing) is widely adopted by a method of laminating an agent and a barrier layer. However, when such a printing surface exists between the base material layer and the barrier layer, the adhesion between the base material layer and the barrier layer is lowered, and delamination is likely to occur between the layers. In particular, since high safety is required for a battery to which the battery packaging material is applied, such a method of printing by back-printing is avoided in the battery packaging material. Therefore, conventionally, when printing a barcode or the like on a battery packaging material, a method of sticking a seal on which a print is formed on the surface of a base material layer is generally employed.

JP 2008-287971 A

  However, when the seal on which the print is formed is affixed to the surface of the base material layer, the thickness and weight of the battery packaging material increase. Therefore, the present inventors considered a method of printing directly on the surface of the base material layer of the battery packaging material by printing ink in consideration of the recent trend of further thinner and lighter battery packaging materials. investigated.

  As a method for printing directly on the surface of the base material layer of the battery packaging material by ink printing, for example, pad printing (also referred to as tampo printing) or ink jet printing is known. Pad printing is a printing method as follows. First, ink is poured into a concave portion of a flat plate in which a pattern to be printed is etched. Next, the silicon pad is pressed from above the concave portion to transfer the ink to the silicon pad. Next, the ink transferred to the surface of the silicon pad is transferred to the printing object to form a print on the printing object. In such pad printing, since the ink is transferred to the object to be printed using an elastic silicon pad or the like, it is easy to print on the surface of the battery packaging material after molding, and the battery element is made of the battery packaging material. After sealing, the battery can be printed. In addition, ink jet printing has similar advantages.

  However, the present inventors have examined that, 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, ink spreading is inappropriate on the surface of the polyester film layer. And the dots of the printed part formed with ink tend to be distorted, and it is difficult to form a print with a desired size and shape.

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

The present inventor has intensively studied to solve the above problems. As a result, at least a base material layer located on the outermost surface, a barrier layer, and a heat-fusible resin layer are configured in this order, and the outermost surface of the base material layer is configured by a polyester film layer. In the case where an infrared absorption spectrum in 18 directions is obtained in 10 ° increments from 0 ° to 170 ° on the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy, the following equation is obtained. The battery packaging material that satisfies the above requirements prevents the spreading of ink on the surface of the polyester film layer and the dots on the printed part from becoming irregularly shaped, and exhibits excellent printability. I found.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
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 the maximum value Y _max and the minimum value Y _min are selected from these, respectively.

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

That is, this invention provides the invention of the aspect hung up below.
Item 1. It is composed of a laminate including at least a base material layer located on the outermost surface, a barrier layer, and a heat-fusible resin layer in this order,
The outermost surface of the base material layer is composed of a polyester film layer,
When an infrared absorption spectrum in 18 directions is acquired in increments of 10 ° from 0 ° to 170 ° on the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy, the following equation is satisfied. Battery packaging material.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Item 2. Item 2. The battery packaging material according to Item 1, which is used for printing on the surface of the polyester film layer.
Item 3. Item 3. The battery packaging material according to Item 1 or 2, wherein the arithmetic average roughness Ra measured on the surface of the polyester film layer is 10 nm or more in accordance with a method defined in JIS B 0601-2001.
Item 4. An adhesive layer is provided between the barrier layer and the heat-fusible resin layer,
Item 4. 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;
Item 5. The battery packaging material according to Item 4, wherein the heat-fusible resin layer contains polypropylene.
Item 6. Any of paragraphs 4 to 5, wherein the adhesive layer is a cured product of a resin composition including 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. A packaging material for a battery according to claim 1.
Item 7. Item 4. The adhesive layer is a cured product of a resin composition including a curing agent having at least one selected from the group consisting of an oxygen atom, a heterocyclic ring, a C═N bond, and a C—O—C bond. The battery packaging material according to any one of -6.
Item 8. 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 a urethane resin, an ester resin, and an epoxy resin.
Item 9. Item 9. The battery packaging material according to any one of Items 4 to 8, wherein the adhesive layer has a thickness of 50 μm or less.
Item 10. Item 9. 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 co-extrusion laminate of the adhesive layer and the heat-fusible resin layer.
Item 12. 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 to 50 μm.
Item 13. Item 13. The battery packaging material according to any one of Items 1 to 12, wherein the polyester film layer is composed of a stretched polyester film.
Item 14. When an infrared absorption spectrum in 18 directions is acquired in increments of 10 ° from 0 ° to 170 ° on the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy, the following equation is satisfied. The battery packaging material according to any one of Items 1 to 13.
1.1 ≦ Y _max / Y _min <1.4
Item 15. At least one surface of the barrier layer is provided with an acid resistant film,
When the acid-resistant film is analyzed using time-of-flight secondary ion mass spectrometry, at least one selected from the group consisting of Ce ₂ PO ⁴⁺ , CePO ⁴⁻ , CrPO ²⁺ , and CrPO ^4−. Item 15. The battery packaging material according to any one of Items 1 to 14, wherein a peak derived from the seed is detected.
Item 16. The item according to any one of Items 1 to 15, further comprising an acid-resistant film containing at least one selected from the group consisting of a phosphorus compound, a chromium compound, a fluoride, and a triazine thiol compound on at least one surface of the barrier layer. A packaging material for a battery as described in 1.
Item 17. 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. 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 in which 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. Item 20. The battery according to Item 19, which has a printing portion on the surface of the polyester film layer.
Item 21. A housing step of housing a battery element including 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,
In at least one of the before and after the containing step, a step of printing on the surface of the polyester film layer;
A method for producing a battery.
Item 22. A polyester film for use in a polyester film layer located on the outermost surface of a battery packaging material,
Using the total reflection method of Fourier transform infrared spectroscopy, when the infrared absorption spectrum in 18 directions is obtained in increments of 10 ° from 0 ° to 170 ° for the surface of the polyester film, the following equation is satisfied: Polyester film.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Item 23. Polyester film satisfying the following formula when an infrared absorption spectrum in 18 directions is acquired in increments of 10 ° from 0 ° to 170 ° on the surface of the polyester film using the total reflection method of Fourier transform infrared spectroscopy. Of the polyester film layer located on the outermost surface of the battery packaging material.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.

  ADVANTAGE OF THE INVENTION According to this invention, the battery packaging material which is equipped with the polyester film layer in the outermost surface can provide the battery packaging material excellent in the printability of the surface of the said polyester film layer.

It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. 4 is an image of a printed part formed on the surface of a biaxially stretched polyethylene terephthalate film, observed with a laser microscope, for Example 2. FIG. It is an image of the printing part formed in the biaxially-stretched polyethylene terephthalate film surface observed with the laser microscope about the comparative example 7. FIG.

The battery packaging material of the present invention is composed of a laminate comprising at least a base material layer located on the outermost surface, a barrier layer, and a heat-fusible resin layer in this order, and the outermost surface of the base material layer is It is composed of a polyester film layer, and using the total reflection method of Fourier transform infrared spectroscopy, an infrared absorption spectrum in 18 directions was obtained in steps of 10 ° from 0 ° to 170 ° on the surface of the polyester film layer. In this case, the following expression is satisfied. Hereinafter, the battery packaging material of the present invention will be described in detail.
Y _max / Y _min <1.4
In the above formula, Y _max, the at 18 each direction direction, respectively, the infrared absorption spectrum at a wavenumber of 1340 cm ^-1 absorption peak intensity Y ₁₃₄₀ in the (CH ₂ wagging vibrations), the absorption peak intensity at a wave number 1410 cm ^-1 This is the maximum value among the values divided by Y ₁₄₁₀ (C = C stretching vibration).
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
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 the maximum value Y _max and the minimum value Y _min are selected from these, respectively.

  Hereinafter, the battery packaging material of the present invention will be described in detail. In the present specification, for the numerical range, the numerical range indicated by “to” means “above” or “below”. For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. Laminated structure of battery packaging material The battery packaging material of the present invention includes a base material layer 1, a barrier layer 3, and a heat-fusible resin layer 4 positioned in this order, for example, as shown in FIG. It consists of a laminate. Moreover, the outermost surface of the base material layer 1 is comprised by the polyester film layer. In the battery packaging material of the present invention, the polyester film layer is the outermost layer side, and the heat-fusible resin layer 4 is the innermost layer. That is, when the battery is assembled, the battery element is sealed by heat-sealing the heat-fusible resin layers 4 positioned at the periphery of the battery element to seal the battery element.

  As will be described later, the base material layer 1 may include other layers in addition to the polyester film layer. Moreover, when the base material layer 1 is provided with the said other layer, the polyester film layer and the other layer may be adhere | attached with the adhesive bond layer. In addition, as shown in FIG. 2, for example, the battery packaging material of the present invention is provided with an adhesive layer 2 between the base material layer 1 and the barrier layer 3 for the purpose of enhancing their adhesion. You may have. Moreover, you may provide the contact bonding layer 5 between the barrier layer 3 and the heat-fusible resin layer 4 as needed in order to improve these adhesiveness.

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

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

2. Each layer forming the battery packaging material [base material layer 1]
In the battery packaging material of the present invention, the base material 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. In the present invention, even when a lubricant is present on the surface of the polyester film layer, the polyester film layer to which the lubricant is attached constitutes the outermost surface of the battery packaging material. For this reason, also about the base material layer 1 which has a lubricant in the surface, the base material layer 1 is a layer located in the outermost surface of the packaging material for batteries.

In the battery packaging material of the present invention, the polyester film layer constituting the outermost surface uses a total reflection method of Fourier transform infrared spectroscopy, and the surface of the polyester film layer is 10 ° from 0 ° to 170 °. When infrared absorption spectra in 18 directions are acquired in increments, the following expression is satisfied.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is a value obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. The minimum value.
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 the maximum value Y _max and the minimum value Y _min are selected from these, respectively.

  In the battery packaging material of the present invention, the outermost surface of the base material layer is composed of a polyester film layer, and the polyester film layer has the specific degree of surface orientation. Despite being constituted by a polyester film, excellent printability 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, it is considered that the ink easily spreads in the uniform direction on the surface of the polyester film layer, and excellent printability is exhibited. In a conventional battery packaging material, when a polyester film layer is used as a base material layer, a polyester film having a high degree of orientation of the polyester molecule has been used from the viewpoint of enhancing the moldability, etc. However, in the present invention, the polyester film layer constituting the outermost surface exhibits the above-described degree of surface orientation, thereby exhibiting excellent printability. There are techniques for improving the printability by causing a lubricant to be present on the surface of the base material layer, or by subjecting the base material layer to a surface treatment. In the present invention, these techniques can also be adopted. Since the polyester film layer has the specific degree of surface orientation, excellent printability is exhibited even though the outermost surface is composed of the polyester film.

  Specific measurement conditions of the infrared absorption spectrum are as follows. In addition, the measurement of the infrared absorption spectrum in the surface of a polyester film layer can be performed in the state laminated | stacked on the packaging material for batteries.

(Infrared absorption spectrum measurement conditions)
Spectrometer (attached with a one-time reflection ATR accessory)
Detector: MCT (Hg Cd Te)
Wave number resolution: 8cm ^-1
Integration count: 128 times IRE: Ge
Incident angle: 30 °
Polarizer: wire-grid, S-polarized light Baseline: absorption peak intensity at average wavenumber 1340 cm ^-1 of the intensity in the wave number range of 1800~2000cm ^-1 Y _1340: the maximum value of the peak intensity in the range of wave number 1335～1342Cm ^-1 based absorption peak intensity at a wave number 1410 cm ^-1 minus the value of the line Y _1410: minus the baseline values from the maximum value of the peak intensity in the range of wave number 1400～1410Cm ^-1

  The infrared absorption spectrum in 18 directions is obtained by placing a sample with the polyester film exposed horizontally on a sample holder and rotating the Ge crystal placed on the sample by 10 °. The incident angle is an angle between a normal line (normal line) and incident light.

From the viewpoint of improving the printability of the battery packaging material, the surface orientation degree (Y _max / Y _min ) is less than 1.4 for the upper limit. The upper limit is preferably about 1.3 or less, and the lower limit is preferably about 1.0 or more, more preferably about 1.1 or more, and still more preferably about 1.2 or more. Preferred range About 1.0 to less than 1.4, about 1.0 to 1.3, about 1.1 to less than 1.4, about 1.1 to 1.3, about 1.2 to less than 1.4 1.2 to 1.3 or the like. When the surface orientation degree (Y _max / Y _min ) is about 1.1 or more, the formability can be suitably improved while improving the printability of the battery packaging material.

The polyester film having the above surface orientation degree: Y _max / Y _min is obtained by appropriately adjusting, for example, a stretching method, a stretching ratio, a stretching speed, a cooling temperature, a heat setting temperature, etc. in manufacturing the polyester film. Can be manufactured.

  In the battery packaging material of the present invention, the arithmetic average roughness Ra of the polyester film layer constituting the outermost surface is preferably about about the upper limit from the viewpoint of improving the printability of the battery packaging material. The lower limit is preferably about 10 nm or more, more preferably about 20 nm or more, and the preferred range is about 10 to 1000 nm, or about 20 to 500 nm. .

  The arithmetic average roughness Ra of the polyester film layer constituting the outermost surface is a value obtained in accordance with the method defined in JIS B 0601-2001 for the surface of the polyester film layer. For specific measurement methods, the methods described in the examples can be employed. In addition, the measurement of the said arithmetic mean roughness Ra of a polyester film layer can be performed in the state laminated | stacked on the packaging material for batteries.

  The arithmetic average roughness Ra of the surface of the polyester film layer can be adjusted by the height, density and the like of the unevenness of the surface of the cooling roll when the polyester film is produced. The polyester film layer may contain the following additives (flame retardant, anti-blocking agent, antioxidant, light stabilizer, tackifier, antistatic agent, etc.) as particles. The arithmetic average roughness Ra may be adjusted. 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% by mass.

  As the polyester constituting the polyester film layer, specifically, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolymerized polyester mainly composed of ethylene terephthalate, Examples thereof include copolymer polyesters mainly composed of butylene terephthalate as a repeating unit. The copolymer polyester mainly composed of ethylene terephthalate is a copolymer polyester that polymerizes with ethylene isophthalate mainly composed of ethylene terephthalate (hereinafter, polyethylene (terephthalate / isophthalate)). Abbreviated), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) And polyethylene (terephthalate / decanedicarboxylate). In addition, as a copolymer polyester mainly composed of butylene terephthalate as a repeating unit, specifically, a copolymer polyester that polymerizes with butylene isophthalate having butylene terephthalate as a repeating unit (hereinafter referred to as polybutylene (terephthalate / isophthalate)). For example), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate and the like. These polyesters may be used individually by 1 type, and may be used in combination of 2 or more type. Polyester has the advantage that it is excellent in heat resistance and electrolytic solution resistance, and is less likely to cause whitening due to the adhesion of the electrolytic solution, and is suitably used as a material for forming the base material layer 1.

  The polyester film layer may be either a stretched polyester film or an unstretched polyester film, but from the viewpoint of suitably improving the moldability of the battery packaging material, it is preferably a stretched polyester film, more preferably a biaxially stretched polyester. It can be constituted by a film, more preferably a biaxially stretched polyethylene terephthalate film. Examples of the stretching method include a sequential biaxial stretching method, an inflation method, and a simultaneous biaxial stretching method.

  The thickness of the polyester film layer is not particularly limited, but from the viewpoint of improving the moldability while reducing the thickness of the battery packaging material, the upper limit is, for example, about 50 μm or less, preferably about 30 μm or less, more preferably The lower limit is preferably about 1 μm or more, more preferably about 5 μm or more, and further about 10 μm or more. Preferred ranges are about 1 to 50 μm, about 1 to 30 μm, 1 to Examples include about 25 μm, about 5 to 50 μm, about 5 to 30 μm, about 5 to 25 μm, about 10 to 50 μm, about 10 to 30 μm, and about 10 to 25 μm.

The polyester film layer may be a single layer or a multilayer (multilayer structure). When the polyester film layer is a multilayer, at least the polyester film located on the outermost layer side (the side opposite to the barrier layer 3) only needs to satisfy the degree of surface orientation described above. The polyester film may have a surface orientation degree: Y _max / Y _min of 1.4 or more.

  In addition to the polyester film layer, the base material layer 1 has a resin film and a coating made of a material different from polyester on the barrier layer side of the polyester film layer in order to improve the moldability of the battery packaging material. It is also possible to form a base material layer 1 by laminating at least one of them (multilayer structure).

  Examples of other resin films used for the base material layer 1 include polyamide, polyolefin, epoxy resin, acrylic resin, fluorine resin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and mixtures and copolymers thereof. Examples thereof include a resin film composed of an object. Specific examples of the configuration in which a polyester film and a resin film made of different materials are laminated include a multilayer structure in which a polyester film layer and a polyamide film layer are laminated.

  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 6,6; Hexamethylenediamine-isophthalic acid-terephthalic acid copolymer such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing structural units derived from acid and / or isophthalic acid Polyamide, polyamide MXD6 (polyamide containing aromatics such as polymetaxylylene adipamide; alicyclic polyamide such as polyaminomethylcyclohexyl adipamide (PACM6); and lactam component, 4,4′-diphenylmethane diisocyanate, etc. Isocyanine Polyamides copolymerized with polyester components, polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of copolymerized polyamides and polyesters or polyalkylene ether glycols; polyamide films such as these copolymers These polyamide films may be used singly or in combination of two or more, and the polyamide film is excellent in stretchability and is whitened by resin cracking during molding. Generation | occurrence | production can be prevented and it is used suitably as a resin film used for the base material layer 1 with a polyester film.

  Specific examples of the case where the base material layer 1 has a multilayer structure of a polyester film and the case where the other resin film is provided include a laminate of a polyester film and a nylon film, and a laminate in which a plurality of polyester films are laminated. More preferably, a laminate of a stretched polyester film and a stretched nylon film and a laminate in which a plurality of stretched polyester films are laminated. For example, when the base material 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, or a structure in which polyethylene terephthalate and nylon are laminated, or More preferably, polyethylene terephthalate and polyethylene terephthalate are laminated. In addition, the polyester film is hardly discolored when, for example, the electrolytic solution adheres to the surface. In the battery packaging material of the present invention, the polyester film layer constitutes the outermost surface, so that the electrolytic solution resistance is excellent. Can be configured.

  When the base material layer 1 has a multilayer structure, the lower limit of the thickness of the polyester film that is not located in the outermost layer or the resin film other than the polyester film is preferably about 3 μm or more, more preferably about 5 μm or more. The upper limit is preferably about 30 μm or less, preferably about 25 μm or less, and the preferred range is about 3 to 30 μm, about 3 to 25 μm, about 5 to 30 μm, or about 5 to 25 μm.

  When the base material layer 1 has a multilayer structure, the polyester film or each resin film may be bonded via an adhesive, or may be directly laminated without using an adhesive. In the case of bonding without using an adhesive, for example, a method of bonding in a hot-melt state such as a co-extrusion method, a sandwich lamination method, or a thermal lamination method can be used. Moreover, when making it adhere | attach through an adhesive agent, the adhesive agent to be used may be a two-component curable adhesive, or a one-component curable adhesive. Furthermore, the adhesive mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, an electron beam curable type, an ultraviolet curable type, and the like. Specific examples of the adhesive include those similar to the adhesive exemplified in the adhesive layer 2. Further, the thickness of the adhesive can be the same as that of the adhesive layer 2.

  Moreover, when the base material layer 1 has a multilayer structure, the adhesive composition for adhering the polyester film and each resin film is preferably a resin composition containing a modified thermoplastic resin graft-modified with an unsaturated carboxylic acid derivative component. Is mentioned. The modified thermoplastic resin is preferably a resin obtained by modifying a polyolefin, a styrene elastomer, a polyester elastomer or the like with an unsaturated carboxylic acid derivative component. The said 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, unsaturated carboxylic acid, an acid anhydride of unsaturated carboxylic acid, ester of unsaturated carboxylic acid, etc. are mentioned. As the unsaturated carboxylic acid derivative component, one kind may be used alone, or two or more kinds may be used in combination.

  Polyolefins in the modified thermoplastic resin include low density polyethylene, medium density polyethylene, high density polyethylene; ethylene-α olefin copolymer; homo, block or random polypropylene; propylene-α olefin copolymer; And copolymers obtained by copolymerizing polar molecules such as methacrylic acid; polymers such as crosslinked polyolefin. One kind of polyolefin may be used alone, or two or more kinds of combinations may be used.

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

  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 kind of polyolefin may be used alone, or two or more kinds of combinations may be used.

  Examples of the unsaturated carboxylic acid in the modified thermoplastic resin include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, bicyclo [2,2,1] hept-2-ene- Examples include 5,6-dicarboxylic acid. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo [2,2,1] hept-2-ene-5,6- And dicarboxylic acid anhydride. Examples of the unsaturated carboxylic acid ester include methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, diethyl fumarate, dimethyl itaconate, diethyl citraconic acid, tetrahydro And esters of unsaturated carboxylic acids such as dimethyl phthalic anhydride and dimethyl bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylate.

  As the modified thermoplastic resin, with respect to 100 parts by mass of the base thermoplastic resin, about 0.2 to 100 parts by mass of the unsaturated carboxylic acid derivative component is heated and reacted in the presence of a radical initiator. Can be obtained.

  The reaction temperature is preferably about 50 to 250 ° C, more preferably about 60 to 200 ° C. Although the reaction time depends on the production method, in the case of a melt graft reaction by a twin screw extruder, the reaction time is preferably about 2 to 30 minutes, more preferably about 5 to 10 minutes. Further, the denaturation reaction can be carried out under both normal pressure and pressurized conditions.

  Examples of the radical initiator used in the modification reaction include organic peroxides. Various materials can be selected as the organic peroxide depending on temperature conditions and reaction time. For example, alkyl peroxides, aryl peroxides, acyl peroxides, ketone peroxides, peroxyketals, peroxycarbonates, peroxides. Examples thereof include oxyesters and hydroperoxides. In the case of the melt graft reaction by the above-described twin screw extruder, alkyl peroxides, peroxyketals, and peroxyesters are preferable, and di-t-butyl peroxide, 2,5-dimethyl-2,5-di-t- It is more preferable to use butylperoxy-hexyne-3, dicumyl peroxide.

  When the base material layer 1 has a multilayer structure, the thickness of the adhesive layer positioned between the polyester film and each resin film is preferably about 0.1 to 5 μm, more preferably about 0.5 to 3 μm. It is done. In addition, the said adhesive bond layer may contain the coloring agent similar to the adhesive bond layer 2 mentioned later.

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

  Although it does not restrict | limit especially 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, aromatic bisamide and the like. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxy stearic acid amide and the like. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide and the like. Specific examples of methylolamide include methylol stearamide. Specific examples of saturated fatty acid bisamides include methylene bis stearamide, ethylene biscapric amide, ethylene bis lauric acid amide, ethylene bis stearic acid amide, ethylene bishydroxy stearic acid amide, ethylene bisbehenic acid amide, hexamethylene bis stearic acid amide. Examples include acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N, N′-distearyl adipic acid amide, N, N′-distearyl sebacic acid amide, and the like. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide Etc. Specific examples of the fatty acid ester amide include stearoamidoethyl stearate. Specific examples of the aromatic bisamide include m-xylylene bis stearic acid amide, m-xylylene bishydroxy stearic acid amide, N, N′-distearyl isophthalic acid amide and the like. Further, as the silicone-based lubricant, non-reactive modified silicone oils such as alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, and polyether-modified silicone oil are preferable. One type of lubricant may be used alone, or two or more types may be used in combination.

When there is a lubricant on the surface of the polyester film layer, the amount of the lubricant is not particularly limited, but from the viewpoint of exhibiting excellent printability, it is preferably about 3 mg / m ² or more, more preferably 3 to 15 mg / m. m ² approximately, more preferably include about 4~14mg / m ^2. Even when a lubricant is present on the surface of the polyester film layer, the infrared absorption spectrum can be measured on the surface of the polyester film layer where the lubricant is present on the surface.

  Additives such as a flame retardant, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent may be present in at least one of the inside and the surface of the base material layer 1. Only one type of additive may be used, or two or more types may be mixed and used.

  Although it does not restrict | limit especially as thickness (total thickness) of the base material layer 1, From a viewpoint of improving a moldability, making a battery packaging material thin, about an upper limit, for example, is about 50 micrometers or less, Preferably it is about 40 micrometers or less. The lower limit is preferably about 3 μm or more, more preferably about 5 μm or more, and further about 10 μm or more. The preferred range of the thickness of the base layer 1 is about 3 to 50 μm, 3 to Examples include about 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 provided between the base material layer 1 and the barrier layer 3 as necessary in order to firmly bond them.

  The adhesive layer 2 is formed of an adhesive capable of bonding the base material layer 1 and the barrier layer 3 together. The adhesive used for forming the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Furthermore, 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 heat melting type, a hot pressure type, and the like.

  Specific examples of adhesive components that can be used to form the adhesive layer 2 include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolymer polyester, and other polyesters; Agent; Polyurethane adhesive; Epoxy resin; Phenol resin; Polyamide such as nylon 6, nylon 66, nylon 12 and copolymerized polyamide; Polyolefin such as polyolefin, carboxylic acid modified polyolefin, metal modified polyolefin, polyvinyl acetate; Cellulose adhesive ; (Meth) acrylic resin; polyimide; polycarbonate; amino resin such as urea resin and melamine resin; rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; Butter, and the like can be mentioned. These adhesive components may be used individually by 1 type, and may be used in combination of 2 or more type. Among these adhesive components, a polyurethane adhesive is preferable.

The polyurethane adhesive is a polyurethane adhesive containing a main component containing a polyol component (A) and a curing agent containing a polyisocyanate component (B), and the polyol component (A) is a polyester polyol (A1). The polyester polyol (A1) is a polyester polyol having a number average molecular weight of 5,000 to 50,000, which is composed of a polybasic acid component and a polyhydric alcohol component. Examples include those containing an acid component of 45 to 95 mol% and having a tensile stress of 100 kg / cm ² or more and 500 kg / cm ² or less when the adhesive layer is 100% elongated. Moreover, it is the polyurethane adhesive for battery packaging materials containing a main ingredient and a polyisocyanate hardening | curing agent, Comprising: The main ingredient is polyester polyol (A1) 5-50 weight% with a glass transition temperature of 40 degreeC or more, and a glass transition temperature. Curing agent for the total of hydroxy groups and carboxyl groups derived from the polyol component (A), comprising a polyol component (A) containing 95 to 50% by weight of the polyester polyol (A2) lower than 40 ° C. and the silane coupling agent (B). The equivalent ratio [NCO] / ([OH] + [COOH]) of isocyanate groups contained therein is 1 to 30.

  Furthermore, either one or more resins (A) selected from the group consisting of modified polypropylene and acrylic resins, or any one of coupling agents (B) containing at least one of a silane coupling agent and a titanate coupling agent ( The adhesive containing resin containing (A) or (B)) is also mentioned.

  Moreover, the adhesive layer 2 may contain a colorant. When the adhesive layer 2 includes a colorant, the battery packaging material can be colored. As the colorant, known ones such as pigments and dyes can be used. Moreover, only 1 type may be used for a coloring agent, and 2 or more types may be mixed and used for it.

  For example, specific examples of inorganic pigments preferably include carbon black and titanium oxide. Specific examples of organic pigments preferably include azo pigments, phthalocyanine pigments, and condensed polycyclic pigments. Examples of the azo pigment 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. Examples of the phthalocyanine pigment include copper phthalocyanine pigment, no pigment Examples of the metal phthalocyanine pigment include a blue pigment and a green pigment, and examples of the condensed polycyclic pigment include dioxazine violet and quinacridone violet. Moreover, as a pigment, a pearl pigment, a fluorescent pigment, etc. can be used.

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

  The average particle diameter of the pigment is not particularly limited, and examples thereof include about 0.05 to 5 μm, preferably about 0.08 to 2 μm. In addition, let the average particle diameter of a pigment be the median diameter measured with the laser diffraction / scattering type particle size 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 examples thereof include about 5 to 60% by mass.

  Although it will not restrict | limit especially if the thickness of the adhesive bond layer 2 exhibits the function as an adhesive layer, For example, about 1-10 micrometers, Preferably about 2-5 micrometers is mentioned.

[Colored layer]
The colored layer is a layer provided as necessary between the base material layer 1 and the adhesive layer 2 (illustration is omitted). By providing 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 material layer 1 or the surface of the barrier layer 3. As the colorant, known ones such as pigments and dyes can be used. Moreover, only 1 type may be used for a coloring agent, and 2 or more types may be mixed and used for it.

  Specific examples of the colorant contained in the colored layer are the same as those exemplified in the column of [Adhesive layer 2].

[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 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-deposited film, an inorganic oxide vapor-deposited film, a carbon-containing inorganic oxide vapor-deposited film, a film provided with these vapor-deposited layers, or the like, and is a layer formed of metal. Preferably there is. Specific examples of the metal constituting the barrier layer 3 include aluminum, stainless steel, titanium steel, 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 the generation of wrinkles and pinholes in the barrier layer 3 during the production of the battery packaging material, the barrier layer is made of, for example, annealed aluminum (JIS H4160: 1994 A8021H-O, JIS H4160: (1994 A8079H-O, JIS H4000: 2014 A8021P-O, JIS H4000: 2014 A8079P-O) and the like are more preferable.

  Examples of the stainless steel foil include austenitic stainless steel foil and ferritic stainless steel foil. The stainless steel foil is preferably made of austenitic stainless steel.

  Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L, etc. Among them, SUS304 is particularly preferable.

  The thickness of the barrier layer 3 is not particularly limited as long as it functions as a barrier layer such as water vapor, but from the viewpoint of reducing the thickness of the battery packaging material, the upper limit is preferably about 85 μm or less, more preferably The lower limit is preferably about 10 μm or more, and the thickness range is, for example, about 10 to 85 μm, preferably about 10 to 50 μm, more preferably about 50 μm or less. It can be set to about 10 to 45 μm. 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, still more preferably about 40 μm or less, and further preferably about 30 μm or less. The lower limit is about 10 μm or more, and the preferable thickness range is about 10 to 85 μm, about 10 to 50 μm, more preferably about 10 to 40 μm, and more preferably. About 10-30 micrometers is mentioned, More preferably, about 15-25 micrometers is mentioned.

  The barrier layer 3 is preferably subjected to chemical conversion treatment on at least one surface, preferably both surfaces, for stabilization of adhesion, prevention of dissolution and corrosion, and the like. 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, the barrier layer 3 includes an acid resistant film. As the chemical conversion treatment, for example, chromate chromate using chromic acid compounds such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromic acetyl acetate, chromium chloride, potassium sulfate chromium, etc. Treatment; Phosphoric acid chromate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; aminated phenol having a repeating unit represented by the following general formulas (1) to (4) Examples include chromate treatment using a polymer. 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. Also good.

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. R ¹ and R ² are the same or different and each represents a hydroxy group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, C1-C4 linear or branched alkyl groups, such as a tert- butyl group, are mentioned. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, 3- C1-C4 straight or branched chain in which one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group is substituted An alkyl group is mentioned. In the 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. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxy group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having a repeating unit represented by the general formulas (1) to (4) is, for example, preferably 500 to 1,000,000, and more preferably 1,000 to 20,000. .

  Further, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, a phosphoric acid is coated with a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide, or barium sulfate fine particles dispersed therein. A method of forming an acid-resistant film on the surface of the barrier layer 3 by performing a baking treatment at 150 ° C. or higher can be mentioned. Further, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed on the acid resistant film. Here, examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine graft acrylic resin obtained by graft polymerization of a primary amine on an acrylic main skeleton, and polyallylamine. Or the derivative, aminophenol, etc. are mentioned. As these cationic polymers, only one type may be used, or two or more types may be used in combination. 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, and a silane coupling agent. As these crosslinking agents, only one type may be used, or two or more types may be used in combination.

As a specific method of providing an acid-resistant film, for example, as an example, at least the surface on the inner layer side of an aluminum foil (barrier layer) is first subjected to an alkali dipping method, electrolytic cleaning method, acid cleaning method, electrolytic A degreasing treatment is performed by a known treatment method such as an acid cleaning method or an acid activation method, and then a phosphoric acid Cr (chromium) salt, phosphoric acid Ti (titanium) salt, phosphoric acid Zr (zirconium) salt, phosphorus Treatment liquid (aqueous solution) mainly composed of a metal phosphate such as Zn (zinc) salt and a mixture of these metals, or a mixture of a non-metal phosphate and a mixture of these non-metals The treatment liquid (aqueous solution) or a treatment liquid (aqueous solution) composed of a mixture of these with an aqueous synthetic resin such as an acrylic resin, a phenol resin, or polyurethane is subjected to a roll coating method, a gravure printing method, or an immersion method. By coating with a known coating method, it is possible to form the acid-resistant coating. For example, when treated with a Cr (chromium) phosphate-based treatment solution, CrPO ₄ (chromium phosphate), AlPO ₄ (aluminum phosphate), Al ₂ O ₃ (aluminum oxide), Al (OH) _x (water Zn ₂ PO ₄ · 4H ₂ O (zinc phosphate hydrate) when treated with an acid-resistant film made of aluminum oxide), AlF _x (aluminum fluoride), etc. ), AlPO ₄ (aluminum phosphate), Al ₂ 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 providing an acid-resistant film, for example, at least the surface on the inner layer side of the aluminum foil, first, an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid activity An acid-resistant film can be formed by performing a degreasing process by a known processing method such as a chemical conversion method and then performing a known anodizing process on the degreasing surface.

  Moreover, as another example of an acid-resistant film | membrane, the film | membrane of a phosphorus compound (for example, phosphate type) and a chromium compound (chromic acid type) is mentioned. Examples of the phosphate system include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, and chromium phosphate. Examples of the chromic acid system include chromium chromate.

  In addition, as another example of the acid-resistant film, by forming an acid-resistant film such as phosphate, chromate, fluoride, triazine thiol compound, between the aluminum and the base material layer at the time of embossing molding Prevention of delamination, hydrogen fluoride generated by the reaction between electrolyte and moisture prevents dissolution and corrosion of the aluminum surface, especially the dissolution and corrosion of aluminum oxide present on the aluminum surface, and adhesion of the aluminum surface This improves the wettability and prevents delamination between the base material layer and aluminum at the time of heat sealing. In the embossed type, it shows the effect of preventing delamination between the base material layer and aluminum at the time of press molding. Among substances that form an acid-resistant film, an aqueous solution composed of three components of a phenol resin, a chromium fluoride (3) compound, and phosphoric acid is applied to the aluminum surface, and the dry baking treatment is good.

  The acid-resistant film includes a layer having cerium oxide, phosphoric acid or phosphate, an anionic polymer, and a crosslinking agent that crosslinks the anionic polymer, and the phosphoric acid or phosphate is 1-100 mass parts may be mix | blended with respect to 100 mass parts of cerium oxides. It is preferable that the acid-resistant film has a multilayer structure further including a layer having a cationic polymer and a crosslinking agent for crosslinking the cationic polymer.

  Furthermore, it is preferable that the anionic polymer is poly (meth) acrylic acid or a salt thereof, or a copolymer having (meth) acrylic acid or a salt thereof as a main component. Moreover, it is preferable that the said crosslinking agent is at least 1 sort (s) chosen from the group which has a functional group in any one of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent.

  The phosphoric acid or phosphate is preferably condensed phosphoric acid or condensed phosphate.

  As the chemical conversion treatment, only one type of chemical conversion treatment may be performed, or two or more types of chemical conversion treatment may be performed in combination. Furthermore, these chemical conversion treatments may be carried out using one kind of compound alone, or may be carried out using a combination of two or more kinds of compounds. Among the chemical conversion treatments, chromic acid chromate treatment, chromate treatment combining a chromic acid compound, a phosphoric acid compound, and an aminated phenol polymer are preferable.

  Specific examples of the acid-resistant film include those containing at least one of a phosphorus compound (such as phosphate), a chromium compound (chromate), a fluoride, and a triazine thiol compound. An acid resistant film containing a cerium compound is also preferable. As the cerium compound, cerium oxide is preferable.

  Specific examples of the acid-resistant film include a phosphate film, a chromate film, a fluoride film, and a triazine thiol compound film. As an acid-resistant film, one of these may be used, or a plurality of combinations may be used. Furthermore, as an acid-resistant film, after degreasing the chemical conversion treatment surface of the barrier layer, from a treatment liquid composed of a mixture of a metal phosphate and an aqueous synthetic resin, or a mixture of a non-metal phosphate and an aqueous synthetic resin It may be formed with a treatment liquid.

The composition of the acid resistant film can be analyzed using, for example, time-of-flight secondary ion mass spectrometry. By analyzing the composition of the acid-resistant film using time-of-flight secondary ion mass spectrometry, for example, at least one secondary ion composed of Ce, P and O (for example, Ce ₂ PO ₄ ⁺ , CePO ₄ ^−, etc.) ) Or a peak derived from a secondary ion composed of Cr, P, and O (for example, at least one kind of CrPO ₂ ⁺ , CrPO ₄ ^−, etc.) is detected.

The amount of the acid-resistant film to be formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited. For example, if the above chromate treatment is performed, a chromic acid compound is present per 1 m ² of the surface of the barrier layer 3. About 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of chromium, about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of phosphorus, and 1. It is desirable that it is contained in a proportion of about 0 to 200 mg, preferably about 5.0 to 150 mg.

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

  In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method, etc., and then the temperature of the barrier layer is 70. It is performed by heating so as to be ˜200 ° C. In addition, before the chemical conversion treatment is performed on the barrier layer, the barrier layer may be previously subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing process in this manner, it is possible to more efficiently perform the chemical conversion process on the surface of the barrier layer.

[Heat-fusion 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 that heat-fuses the heat-fusible resin layers and seals the battery element when the battery is assembled.

The resin component used in the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-sealed, and examples thereof include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins. It is done. That is, the resin constituting the heat-fusible resin layer 4 may or may not include a polyolefin skeleton, and preferably includes a polyolefin skeleton. The fact that the resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc., and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the acid modification degree is low, the peak may be 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; homopolypropylene, polypropylene block copolymer (for example, block copolymer of propylene and ethylene), polypropylene Polypropylenes such as random copolymers of (for example, random copolymers of propylene and ethylene); ethylene-butene-propylene terpolymers and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

  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. It is done. Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkene is preferable, and norbornene is more preferable. Styrene can also be used as a constituent monomer.

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

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

  Among these resin components, carboxylic acid-modified polyolefin is preferable; carboxylic acid-modified polypropylene is more preferable.

  The heat-fusible resin layer 4 may be formed of one kind of resin component alone or may be formed of a blend polymer in which two or more kinds of resin components are combined. Furthermore, the heat-fusible resin layer 4 may be formed of only one layer, but may be formed of two or more layers using the same or different resin components.

A lubricant may be included in the heat-fusible resin layer 4. Further, the lubricant present on the surface of the heat-fusible resin layer 4 may be one in which a lubricant contained in the resin constituting the heat-fusible resin layer 4 is exuded, or the heat-fusible resin layer. 4 may be obtained by applying a lubricant to the surface. When the heat-fusible resin layer 4 contains a lubricant, the moldability of the battery packaging material can be improved. The lubricant is not particularly limited, and a known lubricant can be used, and examples thereof include those exemplified in the base material layer 1 described above. One type of lubricant may be used alone, or two or more types may be used in combination. The amount of lubricant present on the surface of the heat-fusible resin layer 4 is not particularly limited, and is preferably about 10 to 50 mg / m ² , more preferably 15 to 50% from the viewpoint of improving the moldability of the electronic packaging material. About 40 mg / m ² can be mentioned.

  The thickness of the heat-fusible resin layer 4 is not particularly limited as long as it functions as a heat-fusible resin layer. For example, the thickness is about 100 μm or less, preferably about 85 μm or less, more preferably about 15 to 85 μm. Is mentioned. For example, when the thickness of the adhesive layer 5 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. When the thickness of the adhesive layer 5 described later is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-fusible resin layer 4 is preferably about 20 μm or more, more preferably 35 to 85 μm. Degree.

[Adhesive layer 5]
In the battery packaging material of the present invention, the adhesive layer 5 is a layer provided between the barrier layer 3 and the heat-fusible resin layer 4 as necessary in order to firmly bond the barrier layer 3 and the heat-fusible resin layer 4.

The adhesive layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4. As the resin used for forming the adhesive layer 5, the adhesive mechanism, the kind of the adhesive component, and the like can be the same as the adhesive exemplified in the adhesive layer 2. Moreover, as resin used for formation of the contact bonding layer 5, polyolefin, such as polyolefin illustrated by the above-mentioned heat-fusible resin layer 4, cyclic polyolefin, carboxylic acid modified polyolefin, carboxylic acid modified cyclic polyolefin, can also be used. From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, the polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene. That is, the resin constituting the adhesive layer 5 may or may not include a polyolefin skeleton, and preferably includes a polyolefin skeleton. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc., and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the acid modification degree is low, the peak may be 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 acid resistant film) and the heat-fusible resin layer 4, the adhesive layer 5 preferably contains an acid-modified polyolefin. The acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of polyolefin with an acid component such as carboxylic acid. Examples of the acid component used for modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or anhydrides thereof. Polyolefins to be modified include polyethylenes such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene; homopolypropylene, polypropylene block copolymers (for example, block copolymers of propylene and ethylene), polypropylene Polypropylenes such as random copolymers (for example, random copolymers of propylene and ethylene); ethylene-butene-propylene terpolymers and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

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

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

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

  Further, from the viewpoint of further improving the adhesion between the barrier layer 3 (or acid-resistant film), the heat-fusible resin layer 4 and the adhesive layer 5, the adhesive layer 5 includes an oxygen atom, a heterocyclic ring, a C = N bond, and It is preferably a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of C—O—C bonds. Examples of the curing agent having a heterocyclic ring include a curing agent having an oxazoline group and a curing agent having an epoxy group. Examples of the curing agent having a C═N bond include a curing agent having an oxazoline group and a curing agent having an isocyanate group. In addition, 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) and X-ray photoelectron spectroscopy (XPS).

  Although it does not restrict | limit especially as a compound which has an isocyanate group, From a viewpoint of improving the adhesiveness of an acid-resistant membrane | film | coat and the contact bonding 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 and nurating them. And a mixture thereof and a copolymer with other polymers.

  As content of the compound which has an isocyanate group in the contact bonding layer 5, it is preferable to exist in the range of 0.1-50 mass% in the resin composition which comprises the contact bonding layer 5, 0.5-40 mass% More preferably, it is in the range.

  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 those having an acrylic main chain. Moreover, as a commercial item, the Epocross series by Nippon Shokubai Co., Ltd. etc. are mentioned, for example.

  The proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. More preferably. Thereby, the adhesiveness of the barrier layer 3 (or acid-resistant film | membrane) and the contact bonding layer 5 can be improved effectively.

  The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure with 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, it is about 100-1000, More preferably, about 200-800 is mentioned. 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 derivative, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, and the like. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 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 in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. Thereby, the adhesiveness of the barrier layer 3 (or acid-resistant film | membrane) and the contact bonding layer 5 can be improved effectively.

  In the present invention, the adhesive layer 5 is a cured 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. When it is a product, the acid-modified polyolefin functions as a main agent, and the compound having an isocyanate group, the compound having an oxazoline group, and the epoxy resin each function as a curing agent.

  The 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 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 kinds 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% by mass, more preferably in the range of about 0.1 to 30% by mass, More preferably, it is in the range of about 0.1 to 10% by mass.

  Furthermore, the adhesive layer 5 can also be suitably formed using, for example, an adhesive. As the adhesive, for example, a non-crystalline polyolefin resin (A) having a carboxyl group, a polyfunctional isocyanate compound (B), and a tertiary amine having no functional group that reacts with the polyfunctional isocyanate compound (B) ( C), the polyfunctional isocyanate compound (B) is contained in a range where the amount of the isocyanate group is 0.3 to 10 mol with respect to a total of 1 mol of carboxyl groups, and with respect to a total of 1 mol of carboxyl groups. And the one formed from the adhesive composition containing the tertiary amine (C) in the range of 1 to 10 mol. Moreover, as an adhesive agent, a styrene-type thermoplastic elastomer (A), a tackifier (B), and a polyisocyanate (C) are contained, and a styrene-type thermoplastic elastomer (A) and a tackifier (B ) And 20 to 90% by weight of the styrenic thermoplastic elastomer (A) and 10 to 80% by weight of the tackifier (B), and the styrenic thermoplastic elastomer (A) is , 0.003 to 0.04 mmol / g of active hydrogen derived from amino group or hydroxyl group, and 1 mol of active hydrogen derived from styrenic thermoplastic elastomer (A), the tackifier (B) The active hydrogen derived from the functional group is 0 to 15 mol, and the polyisocyanate (C) is derived from the active hydrogen derived from the styrenic thermoplastic elastomer (A) and the tackifier (B). The total one mole of the sexual hydrogen, an isocyanate group also such as those formed by the adhesive composition consisting of those that are included within an amount of 3-150 mol.

The thickness of the adhesive layer 5 is not particularly limited as long as it functions as an adhesive layer. For example, the thickness is 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. The lower limit is about 0.1 μm or more, about 0.5 μm or more, about 10 μm or more, and the thickness range is preferably about 0.1 to 50 μm, 0.1 to 40 μm About 0.1-30 μm, about 0.1-20 μm, about 0.1-5 μm, about 0.5-50 μm, about 0.5-40 μm, about 0.5-30 μm, about 0.5-20 μm About 0.5 to 5 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, and about 10 to 20 μm. More specifically, when the adhesive exemplified in the adhesive layer 2 is used, it is preferably 2 to 10 μm, more preferably about 2 to 5 μm. Moreover, when using resin illustrated by the heat-fusible resin layer 4, Preferably it is about 2-50 micrometers, More preferably, about 10-40 micrometers is mentioned. Moreover, if it is a hardened | cured material of acid-modified polyolefin and a hardening | curing agent, Preferably it is about 30 micrometers or less, More preferably, it is about 0.1-20 micrometers, More preferably, about 0.5-5 micrometers is mentioned. If it is the adhesive bond layer formed with the above-mentioned adhesive composition, about 1-30 g / m < ² > is mentioned as thickness after dry-curing. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like.

  As described later, in the production of the laminate constituting the battery packaging material of the present invention, as a method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 on the barrier layer 3 in this order, the barrier layer A method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 on 3 by co-extrusion can be employed. That is, in the battery packaging material of the present invention, the adhesive layer and the heat-fusible resin layer can be a coextruded laminate.

3. Production method of battery packaging material The production method of the battery packaging material of the present invention is not particularly limited as long as a laminate in which layers of a predetermined composition are laminated is obtained. The method for producing a battery packaging material includes, for example, a step of obtaining a laminate by laminating at least a base material layer, a barrier layer, and a heat-fusible resin layer located on the outermost surface in this order. The outermost surface of the base material layer is composed of a polyester film layer, and as the polyester film, the total reflection method of Fourier transform infrared spectroscopy is used, and the surface of the polyester film is 0 ° to 180 °. If you get the 18 direction of the infrared absorption spectrum at 10 ° increments, the ratio of the absorption peak intensity Y ₁₃₄₀ in 1340 cm ^-1 of the infrared absorption spectrum, the absorption peak intensity Y ₁₄₁₀ in 1410cm ^-1 (Y ₁₃₄₀ / _Examples include a method in which the ratio of Y ₁₄₁₀ ) between the maximum value Y _max and the minimum value Y _min (surface orientation degree: Y _max / Y _min ) is less than 1.4.

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

  Next, the adhesive layer 5 and the heat-fusible resin layer 4 are laminated on the barrier layer 3 of the laminate A in this order. For example, (1) a method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 on the barrier layer 3 of the laminate A by coextrusion (coextrusion laminating method), (2) a separate adhesive layer 5 And a layered product of the heat-fusible resin layer 4 and a method of laminating the layered product on the barrier layer 3 of the layered product A by a thermal laminating method. (3) Adhering to the barrier layer 3 of the layered product A An adhesive for forming the layer 5 is formed by extrusion or solution coating, and is laminated at a high temperature by drying or baking, and the heat-fusible resin layer 4 previously formed into a sheet on the adhesive layer 5 is formed. (4) Adhesion while pouring a molten adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-fusible resin layer 4 previously formed into a sheet shape. Laminate A and heat-fusible resin layer 4 are pasted through layer 5 The method (sandwich lamination method), and the like to match.

  As described above, base material layer 1 / adhesive layer 2 provided as necessary / laminated layer 3 / adhesive layer 5 / heat-fusible resin layer 4 whose surface is subjected to chemical conversion treatment as needed Although a body is formed, in order to strengthen the adhesiveness of the adhesive layer 2 or the adhesive layer 5, it may be further subjected to a heat treatment such as a hot roll contact type, a hot air type, a near infrared type or a far infrared type. Good. Examples of such heat treatment conditions include, for example, about 150 to 250 ° C. and about 1 to 5 minutes.

  In the battery packaging material of the present invention, each layer constituting the laminate improves or stabilizes film forming properties, lamination processing, suitability for final processing (pouching, embossing), etc., as necessary. Therefore, surface activation treatment such as corona treatment, blast treatment, oxidation treatment, ozone treatment may be performed.

4). Application of Battery Packaging Material The battery packaging material of the present invention is used in a package for sealing and housing battery elements such as a positive electrode, a negative electrode, and an electrolyte. That is, a battery element including at least a positive electrode, a negative electrode, and an electrolyte can be accommodated in a package 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 including at least a positive electrode, a negative electrode, and an electrolyte is formed using 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. By covering the periphery of the element so that a flange portion (region where the heat-fusible resin layers are in contact with each other) can be formed, and heat-sealing the heat-fusible resin layers of the flange portion to seal the battery A battery using the packaging material is provided. When the battery element is housed in the package formed of the battery packaging material of the present invention, the heat-fusible resin portion of the battery packaging material of the present invention is on the inner side (surface in contact with the battery element). Thus, a package is formed. In addition, the measurement of the infrared absorption spectrum and the arithmetic mean roughness Ra on the surface of the polyester film layer is obtained by obtaining the battery packaging material from the battery and measuring the obtained polyester film layer of the battery packaging material. Can do. However, the measurement of the infrared absorption spectrum and the arithmetic mean roughness Ra of the battery packaging material obtained from the battery is performed by measuring the peripheral flange of the battery (the part where the heat-fusible resin layers are heat-sealed). ) Or a part different from the side part (preferably, the top or bottom of the battery) is measured for the battery packaging material.

  In the present invention, in the package formed of the battery packaging material of the present invention, an accommodating step of accommodating a battery element having at least a positive electrode, a negative electrode, and an electrolyte, and at least one before and after the accommodating step In the method, a battery in which the surface of the polyester film layer is printed can be produced by a method comprising a step of 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 the surface. The printed portion is a portion on which a barcode, pattern, character, symbol or the like formed on the surface of the battery is printed.

  In the battery packaging material of the present invention, when the printability evaluation of the polyethylene terephthalate film surface is performed under the following conditions, the radius of the dots forming the print portion is preferably 130 μm or more, 135 μm or more, 140 μm or more. In addition, it is preferably 151 μm or less and 149 μm or less, and preferable ranges of the radius include about 130 to 151 μm, about 130 to 149 μm, about 135 to 151 μm, about 135 to 149 μm, about 140 to 151 μm, and about 140 to 149 μm. Degree. When the radius of the dot satisfies such a value, it can be evaluated that the printability is excellent. Specifically, printing of barcodes, patterns, characters, symbols, etc. is formed by a collection of ink dots, and if the radius of the dots forming the print section satisfies the above value, the radius of the dots is too small. Desired printing can be performed appropriately.

  In the battery packaging material of the present invention, when the printability of the polyethylene terephthalate film surface is evaluated under the following conditions, the circularity of the dots forming the print portion may be 0.725 or more. preferable. It can be evaluated that the closer the circularity of the printed portion is to 1, the better the printability. Specifically, in the printing of barcodes, patterns, characters, symbols, etc., when the circularity of the dots forming the printing portion satisfies the above value, the dot shape is not irregular and the desired printing is performed appropriately. be able to.

<Evaluation of printability of polyethylene terephthalate film surface>
Ink was printed on the surface of the polyethylene terephthalate film of each of the battery packaging materials produced above in an environment of a temperature of 24 ° C. and a relative humidity of 50% using an inkjet printer (9040 (1.1M head) manufactured by Markem Image Co., Ltd.). And let dry for 10 seconds. Next, the printability of the polyethylene terephthalate film surface is evaluated on the basis of the dot radius and circularity of the printed portion formed on the polyethylene terephthalate film surface. The printing setting conditions are ink viscosity: 3.4 cps, temperature: 34 ° C., pressure: 270 bar, nozzle size: diameter 50 μm, resolution (dot density): 115 dpi. The method for measuring the dot radius and circularity of the printing portion is as described later. The said evaluation is performed in the state of the packaging material for batteries. In addition, the dot radius and circularity of the printing portion are average values of N = 3. In performing the evaluation, an operation such as wiping off the surface of the polyethylene terephthalate film is 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.

  A laser microscope (for example, a laser microscope VK-9710 manufactured by KEYENCE) is used for observing the dot radius and circularity of the printed part formed on the surface of the polyethylene terephthalate film, and the magnification is 10 times.

(Measurement method of dot radius of printed part)
For the image observed with the laser microscope, the shape of the dot of the printed portion dropped on the surface of each polyethylene terephthalate film is measured using image analysis software (for example, analysis software VK Analyzer Ver 2.4.0.0 manufactured by KEYENCE). In the analysis using the three-point circle, the radius of the circle passing through the three points (= the dot radius of the printing portion) is obtained.

(Evaluation of the circularity of the dots on the printed part)
The circularity of the dots of the printed portion formed by the ink dropped on the surface of each polyethylene terephthalate film is measured using image analysis software (for example, image analysis software WinROOF (Ver 6.6.0) manufactured by Mitani Corporation). . It should be noted that the figure connecting the center points of the boundary pixels constituting the outline of the dot is analyzed as an object. On the WinRoof analysis screen, the value is displayed as circularity II. It should be noted that the circularity of the dots in the print portion is calculated by the following formula.
Circularity of dots in the print area = 4π × (dot area) / (dot perimeter) 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. For example, a lithium ion battery, a lithium ion polymer battery, a lead storage battery, a nickel-hydrogen storage battery, a nickel-cadmium storage battery, a nickel- Examples include iron storage batteries, nickel / zinc storage batteries, silver oxide / zinc storage batteries, metal-air batteries, multivalent cation batteries, capacitors, capacitors, and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are suitable applications for 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 located 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, and 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, It is characterized by satisfying Y _max / Y _min <1.4. The specific configuration (composition, thickness, etc.) of the polyester film of the present invention is the same as the polyester film of the polyester film layer constituting the outermost surface in “2. Each layer forming battery packaging material”. . In addition, the measurement of the infrared absorption spectrum in the surface of a polyester film can be performed in the state only of a polyester film about the surface used as the outermost surface side of the packaging material for batteries. Moreover, the measurement of the arithmetic average roughness Ra of the polyester film can also be carried out in the state of only the polyester film on the surface which is the outermost surface side of the battery packaging material.

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

<Manufacture of battery packaging materials>
The battery packaging materials of Examples 1 to 3 and Comparative Examples 1 to 7 were produced by the following method.

(Example 1)
Aluminum having an acid-resistant film formed on both sides on a biaxially stretched polyethylene terephthalate film (having a thickness of 25 μm, having a surface orientation degree of Y _max / Y _min and an arithmetic average roughness Ra in Table 1) as a base material layer A barrier layer made of a foil (JIS H4160: 1994 A8021H-O, thickness 40 μm) was laminated by a dry laminating method. Specifically, a two-component curable urethane adhesive (a polyol compound and an aromatic isocyanate compound) is applied to one surface of an aluminum foil, and an adhesive layer (thickness 3 μm) is formed on the aluminum foil having an acid-resistant film formed on both surfaces. ) Was formed. Subsequently, after laminating the adhesive layer on the aluminum foil and the biaxially stretched polyethylene terephthalate film, an aging treatment was performed to prepare a base material layer / adhesive layer / barrier layer laminate. In addition, the chemical conversion treatment which forms the acid-resistant film | membrane of the aluminum foil used as a barrier layer is 10 mg / m < ² > (dry mass) of the coating amount of chromium in the process liquid which consists of a phenol resin, a chromium fluoride compound, and phosphoric acid. It was performed by applying and baking on both surfaces of the aluminum foil by a roll coating method. In addition, the aluminum foil used as a barrier layer is provided with an acid resistant film containing chromium oxide and phosphate.

  Next, maleic anhydride-modified polypropylene (thickness 25 μm) as an adhesive layer and random polypropylene (thickness 55 μm) as a heat-fusible resin layer are coextruded on the barrier layer of the obtained laminate. By doing so, the adhesive layer / heat-fusible resin layer was laminated on the barrier layer. Next, the resulting laminate is aged and heated to laminate the base layer / adhesive layer / barrier layer / adhesive layer / heat-sealable resin layer with an acid-resistant film on both sides in this order. A battery packaging material was obtained.

The acid-resistant film was analyzed as follows. First, the barrier layer and the adhesive layer were peeled off. At this time, physical peeling was performed without using water, an organic solvent, an aqueous solution of acid or alkali, or the like. Since the adhesive layer remained on the surface of the barrier layer after peeling between the barrier layer and the adhesive layer, the remaining adhesive layer was removed by etching with Ar-GCIB. The surface of the barrier layer thus obtained was analyzed for an acid-resistant film using time-of-flight secondary ion mass spectrometry. As a result, secondary ions composed of Ce, P, and O such as Ce ₂ PO ₄ ⁺ and CePO ₄ ⁻ were detected from the acid-resistant film. Details of the measuring apparatus and measuring conditions of the time-of-flight secondary ion mass spectrometry are as follows.

Measuring apparatus: Time-of-flight secondary ion mass spectrometer TOF. Manufactured by ION-TOF. SIMS5
Measurement conditions Primary ion: Double charged ion of Bismuth cluster (Bi ₃ ⁺⁺ )
Primary ion acceleration voltage: 30 kV
Mass range (m / z): 0 to 1500
Measurement range: 100 μm × 100 μm
Number of scans: 16 scan / cycle
Number of pixels (one side): 256 pixels
Etching ions: Ar gas cluster ion beam (Ar-GCIB)
Etching ion acceleration voltage: 5.0 kV

(Example 2)
On 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), a lubricant (erucic acid amide (coating amount is 6 mg / m ² )) In addition, a battery packaging material was obtained in the same manner as in Example 1 except that polyether-modified silicone oil (application amount: 1 mg / m ² )) was applied (a total application amount was 7 mg / m ² ).

(Example 3)
As a base material layer, a biaxially stretched polyethylene terephthalate film (thickness 12 μm, surface orientation degree in Table 1: Y _max / Y _min and arithmetic average roughness Ra) and a biaxially stretched nylon film (thickness 15 μm) are dry laminated. A laminated film laminated by the method was prepared. In the laminated film, the biaxially stretched polyethylene terephthalate film and the biaxially stretched nylon film are bonded with a urethane adhesive using a polyol and an isocyanate curing agent (thickness after curing is 3 μm). Next, a barrier layer composed of an aluminum foil (JIS H4160: 1994 A8021H-O, thickness 40 μm) provided with an acid-resistant film by performing chemical conversion treatment on both sides on the biaxially stretched nylon film side is dry-laminated. Laminated. Specifically, a two-component polyurethane adhesive (polyol compound and aromatic isocyanate compound) is applied to one surface of an aluminum foil provided with an acid-resistant film, and an adhesive layer (thickness 3 μm) is formed on the aluminum foil. Formed. Next, after laminating the adhesive layer on the aluminum foil and the biaxially stretched nylon film side of the base material layer, the base material layer (biaxially stretched polyethylene terephthalate film / adhesive / biaxial) was performed by performing an aging treatment. Stretched nylon film) / adhesive layer / barrier layer laminate having an acid-resistant film on both sides was prepared. In addition, the aluminum foil used as a barrier layer is equipped with the acid-resistant film | membrane containing chromium oxide and a phosphate on both surfaces. The analysis of the acid-resistant film on the barrier layer was performed using time-of-flight secondary ion mass spectrometry 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 film.

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

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

(Comparative Example 2)
A polyethylene terephthalate film and a nylon film were laminated by coextrusion to prepare a biaxially stretched laminated film. A biaxially stretched polyethylene terephthalate film (having a thickness of 5 μm, having a surface orientation degree of Y _max / Y _min and an arithmetic average roughness Ra in Table 1) and a biaxially stretched nylon film (thickness) of the laminated film constituting the base material layer The adhesive layer (thickness: 1 μm) composed of polyester (polyester elastomer) is present between them. In the laminated film, a biaxially stretched polyethylene terephthalate film / adhesive / biaxially stretched nylon film is laminated in order. Next, dry laminating a barrier layer composed of an aluminum foil (JIS H4160: 1994 A8021H-O, thickness 40 μm), which is subjected to a chemical conversion treatment on both surfaces of the biaxially stretched nylon film side and provided with an acid-resistant film Laminated by the method. Specifically, a two-component polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of an aluminum foil provided with an acid-resistant film to form an adhesive layer (thickness 3 μm). Subsequently, after laminating the adhesive layer on the barrier layer provided with the acid resistant film and the biaxially stretched nylon film side of the base material layer, the base layer (biaxially stretched polyethylene terephthalate film) / Adhesive / biaxially stretched nylon film) / adhesive layer / barrier layer laminate having an acid-resistant film on both sides was prepared.

  Next, an amorphous polyolefin resin having a carboxyl group and an adhesive composed of a polyfunctional isocyanate compound (thickness after curing is 2 μm) are applied and dried at 100 ° C., and the resulting laminate has a barrier layer side. An unstretched polypropylene film (CPP, thickness 80 μm) was passed between two rolls set at 60 ° C. and bonded, thereby laminating an adhesive layer / heat-sealable resin layer on the barrier layer. Next, by carrying out an aging treatment, a base material layer (biaxially stretched polyethylene terephthalate film / adhesive / biaxially stretched nylon film) / adhesive layer / barrier layer / adhesive layer / unstretched polypropylene film is laminated in this order. A battery packaging material was obtained.

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

(Comparative Example 4)
As the biaxially stretched polyethylene terephthalate film of the base material layer, the same as in Example 3 except that a film having the degree of surface orientation shown in Table 1: Y _max / Y _min and arithmetic average roughness Ra was used. A battery packaging material was obtained.

(Comparative Example 5)
As the biaxially stretched polyethylene terephthalate film of the base material layer, the same as in Example 3 except that a film having the degree of surface orientation shown in Table 1: Y _max / Y _min and arithmetic average roughness Ra was used. A battery packaging material was obtained.

(Comparative Example 6)
A lubricant (erucic 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) (the coating amount was 7 mg). / M ² ) A battery packaging material was obtained in the same manner as in Comparative Example 2 except that.

(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) (the coating amount was 10 mg). / M ² ) A battery packaging material was obtained in the same manner as in Comparative Example 2 except that.

<Measurement of surface orientation>
For the biaxially stretched polyethylene terephthalate film surface (surface opposite to the barrier layer) of each battery packaging material prepared above, the total reflection method (ATR) of Fourier transform infrared spectroscopy (FT-IR) is used. Infrared absorption spectra in 18 directions are acquired in increments of 10 ° from 0 ° to 170 °, and absorption peak intensity Y ₁₃₄₀ (CH ₂ longitudinal vibration) at a wave number of ₁₃₄₀ cm ⁻¹ of the infrared absorption spectrum in 18 directions is obtained. Y ₁₃₄₀ / Y ₁₄₁₀ is calculated from the value of the absorption peak intensity Y ₁₄₁₀ (C = C stretching vibration) at a wave number of ₁₄₁₀ cm ⁻¹ , and the surface orientation degree is calculated from the maximum value Y _max and the minimum value Y _min among them. Y _max / Y _min was calculated. Specific measurement conditions of the infrared absorption spectrum are as follows. The results are shown in Table 1.

  For Example 2 and Comparative Examples 6 and 7, the lubricant on the surface of the biaxially stretched polyethylene terephthalate film was wiped with 2-butanone, and the degree of surface orientation was measured for the surface of the biaxially stretched polyethylene terephthalate film.

(Infrared absorption spectrum measurement conditions)
Spectrometer: Nicolet iS10 FT-IR manufactured by Thermo Fisher Scientific
Attached device: One-time reflection ATR accessory device (Seagull)
Detector: MCT (Hg Cd Te)
Wave number resolution: 8cm ^-1
Integration count: 128 times IRE: Ge
Incident angle: 30 °
Polarizer: wire-grid, S-polarized light Baseline: absorption peak intensity at average wavenumber 1340 cm ^-1 of the intensity in the wave number range of 1800-2000cm ^-1 Y _1340: the maximum value of the peak intensity in the range of wave number 1335～1342Cm ^-1 absorption peak intensity Y ₁₄₁₀ in the value wavenumber 1410 cm ^-1 obtained by subtracting the baseline values: a value obtained by subtracting the baseline values from the maximum value of the peak intensity in the range of wave number 1400～1410Cm ^-1

  The infrared absorption spectrum in 18 directions was obtained by placing a sample with the polyester film exposed horizontally on a sample holder and rotating the Ge crystal placed on the sample by 10 °. The incident angle is an angle between a normal line (normal line) and incident light.

<Measurement of arithmetic average roughness Ra of polyethylene terephthalate film surface>
Arithmetic average roughness of the surface of the biaxially stretched polyethylene terephthalate film (polyester film layer) constituting the outermost surface of each battery packaging material obtained in accordance with the method defined in JIS B 0601-2001. Ra was measured. As a measuring device for arithmetic average roughness Ra, a white interferometer NewView 7300 manufactured by Zygo was used, and measurement was performed under the conditions of a measuring area of 0.22 mm square (objective lens 50 times, zoom lens 1 time) and tilt correction (Cylinder). Went. The arithmetic average roughness Ra was measured in the state of the battery packaging material. In the measurement, an operation such as wiping the surface of the polyethylene terephthalate film is not performed. The results are shown in Table 1.

<Evaluation of printability of polyethylene terephthalate film surface>
In an environment of a temperature of 24 ° C. and a relative humidity of 50%, an ink jet printer (9040 (1.1M head) manufactured by Markem Image Co., Ltd.) was applied to the surface of the biaxially stretched polyethylene terephthalate film of each battery packaging material produced above. The ink was dropped using and dried for 10 seconds. Next, the printability of the biaxially stretched polyethylene terephthalate film surface was evaluated based on the dot radius and circularity of the dots formed on the biaxially stretched polyethylene terephthalate film surface. The printing setting conditions were ink viscosity: 3.4 cps, temperature: 34 ° C., pressure: 270 bar, nozzle size: diameter 50 μm, resolution (dot density): 115 dpi. The method for measuring the dot radius and circularity of the printing portion is as described later. The said evaluation was performed in the state of the packaging material for batteries. In addition, the dot radius and circularity of the printed part were average values of N = 3. In performing the evaluation, an operation such as wiping the surface of the polyethylene terephthalate film is not performed. The results are shown in Table 1.

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

  A laser microscope (a laser microscope VK-9710 manufactured by KEYENCE) was used for observing the dot radius and circularity of the printed portion formed on the surface of the biaxially stretched polyethylene terephthalate film, and the magnification was 10 times. For reference, the images of the printed part formed on the surface of the biaxially stretched polyethylene terephthalate film in Example 2 and Comparative Example 7 observed with a laser microscope are shown in FIG. 4 (Example 2) and FIG. 5 (Comparative Example), respectively. 7).

(Measurement method of dot radius of printed part)
The dot shape of the printed part dropped on the surface of each biaxially stretched polyethylene terephthalate film was analyzed using the analysis software VK Analyzer Ver 2.4.0.0 manufactured by KEYENCE for the three-point circle. The radius of the circle passing through the three points (= the radius of the dots on the printed portion) was obtained by the analysis according to the above. The results are shown in Table 1.

(Evaluation of the circularity of the dots on the printed part)
The circularity of the dots of the printed part formed by the ink dropped on the surface of each biaxially stretched polyethylene terephthalate film was measured using image analysis software WinROOF (Ver 6.6.0) manufactured by Mitani Corporation. In addition, the figure which connects the center point of the boundary pixel which comprises the outline of a dot was analyzed as object. On the WinRoof analysis screen, the value is displayed as circularity II. It should be noted that the circularity of the dots in the print portion is calculated by the following formula. The circularity of the dots in the printed part was evaluated according to the following criteria. The results are shown in Table 1. For reference, Table 1 shows the actual measured values of the circularity of the dots in the printing portion for Example 2 (FIG. 4) and Comparative Example 7 (FIG. 5).
Circularity of dots in the print area = 4π × (dot area) / (dot perimeter) ²
A: The circularity of the dots in the printed portion is 0.725 or more, and the dots in the printed portion have a beautiful circle on the surface of the biaxially stretched polyethylene terephthalate film.
B: The degree of circularity of the dots in the printed part is 0.700 or more and less than 0.725, and the dots in the printed part have an irregular circle shape on the surface of the biaxially stretched polyethylene terephthalate film.

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, and the dot radius of the printed portion is small. In addition, the evaluation of the circularity of the dots in the printing portion was excellent, and the printing suitability was excellent. From the results of Examples 1 to 3, it can be seen that excellent printability 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 printing portion The dot radius was large, or the dot circularity of the printed part was poorly evaluated. For example, in Comparative Example 7, although the dot radius of the print portion is small, the circularity is as small as 0.723, and the dot of the print portion has an irregular circle shape on the surface of the polyethylene terephthalate film layer, which is suitable for printing. (See FIG. 5). In Comparative Example 6, there is a lubricant on the surface of the polyester layer, and the dot radius of the printed portion is about the same as that of Comparative Example 2, but the dot radius of the printed portion is larger than in Examples 1-3, The printability was poor. Further, in Comparative Example 7 in which the amount of lubricant was increased as compared with Comparative Example 6, the dot radius of the printed portion was small as described above, but the dot of the printed portion had an irregular circle and was inferior in printability. .

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-fusion resin layer 5 Adhesive layer

Claims (18)

It is composed of a laminate including at least a base material layer located on the outermost surface, a barrier layer, and a heat-fusible resin layer in this order,
The outermost surface of the base material layer is composed of a polyester film layer,
When an infrared absorption spectrum in 18 directions is acquired in increments of 10 ° from 0 ° to 170 ° on the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy, the following equation is satisfied. Battery packaging material.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.   The battery packaging material according to claim 1, wherein the battery packaging material is used for printing on the surface of the polyester film layer.   The battery packaging material according to claim 1 or 2, wherein the arithmetic average roughness Ra measured on the surface of the polyester film layer is 10 nm or more in accordance with a method defined in JIS B 0601-2001. An adhesive layer is provided between the barrier layer and the heat-fusible resin layer,
The battery packaging material according to any one of claims 1 to 3, wherein the adhesive layer contains an acid-modified polyolefin. The acid-modified polyolefin of the adhesive layer is maleic anhydride-modified polypropylene;
The battery packaging material according to claim 4, wherein the heat-fusible resin layer contains polypropylene.   The battery packaging material according to claim 4, wherein the adhesive layer has a thickness of 50 μm or less.   The battery packaging material according to claim 4 or 5, wherein the adhesive layer has a thickness of 10 µm or more and 50 µm or less.   The battery packaging material according to any one of claims 4 to 7, which is a coextruded laminate of the adhesive layer and the heat-fusible resin layer.   The battery packaging material according to any one of claims 1 to 8, wherein the thickness of the polyester film layer is 10 µm or more and 50 µm or less. At least one surface of the barrier layer is provided with an acid resistant film,
When the acid-resistant film is analyzed using time-of-flight secondary ion mass spectrometry, at least one selected from the group consisting of Ce ₂ PO ⁴⁺ , CePO ⁴⁻ , CrPO ²⁺ , and CrPO ^4−. The battery packaging material according to any one of claims 1 to 9, wherein a peak derived from a seed is detected.   The acid-resistant film comprising at least one selected from the group consisting of a phosphorus compound, a chromium compound, a fluoride, and a triazine thiol compound is provided on at least one surface of the barrier layer. A packaging material for a battery according to claim 1.   The battery packaging material according to any one of claims 1 to 11, wherein an acid-resistant film containing a cerium compound is provided on at least one surface of the barrier layer.   The battery packaging material according to any one of claims 1 to 12, wherein a lubricant is present in at least one of the inside and the surface of the polyester film layer. At least a base material layer located on the outermost surface, a barrier layer, and a heat-fusible resin layer are provided so as to be laminated in this order to obtain a laminate.
The outermost surface of the base material layer is composed of a polyester film layer,
When an infrared absorption spectrum in 18 directions is acquired in increments of 10 ° from 0 ° to 170 ° on the surface of the polyester film layer using the total reflection method of Fourier transform infrared spectroscopy, the following equation is satisfied. , A method for producing a battery packaging material.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.   A battery in which 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 claim 1.   The battery according to claim 15, further comprising a printing portion on a surface of the polyester film layer. A housing step of housing a battery element including at least a positive electrode, a negative electrode, and an electrolyte in the packaging body made of the battery packaging material according to claim 1;
At least one of before and after the containing step, a step of printing on the surface of the polyester film layer; and
A method for producing a battery. A polyester film for use in a polyester film layer located on the outermost surface of a battery packaging material,
Using the total reflection method of Fourier transform infrared spectroscopy, when the infrared absorption spectrum in 18 directions is obtained in increments of 10 ° from 0 ° to 170 ° for the surface of the polyester film, the following equation is satisfied: Polyester film.
Y _max / Y _min <1.4
Y _max is the maximum value among values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at a wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at a wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.
Y _min is the minimum value among the values obtained by dividing the absorption peak intensity Y ₁₃₄₀ at the wave number of ₁₃₄₀ cm ⁻¹ in the infrared absorption spectrum by the absorption peak intensity Y ₁₄₁₀ at the wave number of ₁₄₁₀ cm ⁻¹ in each of the 18 directions. It is.