WO2019039504A1 - Packaging material for batteries, battery, and production method for packaging material for batteries - Google Patents

Abstract

Provided is a packaging material for batteries that has excellent surface electrolyte resistance and ink printing characteristics, as well as high rigidity and resistance to forming wrinkles when tape is peeled therefrom. The packaging material for batteries comprises a laminate having, in the following order, at least a protective layer, a base material layer, a stainless steel foil, and a heat-fusible resin layer. When measured by attenuated total reflection using Fourier transform infrared spectroscopy from the outermost surface side of the protective layer, the maximum value A of absorbance in which the detected infrared wavenumber is within the range of 2,800 to 3,000 cm–1 and the maximum value B of absorbance in which the detected infrared wavenumber is within the range of 2,200 to 2,300 cm–1 fulfil the relationship 0.05 ≤ B/A ≤ 0.75.

Description

Packaging material for battery, battery, and method of manufacturing packaging material for battery

The present invention relates to a battery packaging material, a battery, and a method of manufacturing the battery packaging material.

Conventionally, various types of batteries have been developed, but in all batteries, a packaging material has become an indispensable member for sealing battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been widely used as packaging for batteries, but in recent years, various shapes are required for batteries as the performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc. is improved. Needs to be thinner and lighter. However, in the case of metal battery packaging materials that have been widely used in the past, it is difficult to follow the diversification of the shape, and there is also a drawback that there is a limit to weight reduction.

Therefore, a film shape in which a base material layer / adhesive layer / barrier layer / thermal adhesive resin layer are sequentially laminated as a packaging material for a battery which can be easily processed into various shapes and can realize thinning and weight reduction The packaging material for batteries of is proposed (for example, refer to patent documents 1). In such a film-like battery packaging material, the battery element can be sealed by heat-sealable resin layers facing each other and heat-sealing the peripheral portion by heat sealing.

When manufacturing a battery using the above packaging materials for batteries, electrolyte solution may adhere to the base material layer located in the outermost layer surface of the packaging materials for batteries. When the electrolytic solution adheres to the base material layer, the base material layer may be discolored, so a protective layer having electrolytic solution resistance and the like may be provided on the base material layer.

In addition, the ink is printed on the surface of the base material layer side of the battery packaging material for the purpose of imparting distinctiveness to the battery packaging material, etc. to form a bar code, a pattern, characters, etc. A method (generally referred to as reverse printing) for printing on a battery packaging material by a method of laminating an adhesive and a metal foil on the substrate layer of the above is widely adopted. However, when such a printing surface is present between the base material layer and the barrier layer, the adhesion between the base material layer and the barrier layer is reduced, and delamination tends to occur between the layers. In particular, since the battery to which the battery packaging material is applied requires high safety, the method of printing by such reverse printing is avoided in the battery packaging material. Therefore, conventionally, in the case of forming a print such as a bar code on the packaging material for a battery, generally, a method of sticking a seal on which the print is formed on the surface on the base layer side is employed.

However, when the seal on which the print is formed is attached to the surface on the base layer side, the thickness and weight of the battery packaging material increase. Therefore, from the recent trend of thinning and weight reduction of the packaging material for batteries, a method of printing directly on the surface of the packaging material for batteries by printing with ink has been studied.

As a method of printing by direct printing of ink on the surface of the base material layer side of the battery packaging material, for example, pad printing (also referred to as tampo printing) is known. Pad printing is the following printing method. First, the ink is poured into the concave portion of the flat plate in which the pattern to be printed is etched. Next, the silicon pad is pressed from above the recess to transfer the ink to the silicon pad. Next, the ink transferred to the surface of the silicon pad is transferred to a print target to form a print on the print target. Such pad printing is easy to print on the surface of the battery packaging material after molding because the ink is transferred to the printing object using an elastic silicon pad or the like, and the battery element is a battery packaging material. After sealing, it has the advantage of being able to print on the battery.

JP 2008-287971A

As described above, when the electrolytic solution adheres to the base material layer, the base material layer may be discolored, and thus a protective layer having electrolytic solution resistance and the like may be provided on the base material layer. As such a protective layer, for example, a protective layer cured using a curing agent such as a curing agent having an isocyanate group is known (for example, International Publication WO 2013/069698). However, when the present inventors examined, when providing the protective layer hardened using the curing agent which has an isocyanate group, the reaction of an isocyanate group is inadequate (a large amount of unreacted isocyanate remains) If this is the case, the electrolyte resistance does not develop, while the reaction of the isocyanate group proceeds too much (no unreacted isocyanate remains), although the electrolyte resistance is improved, the surface of such a protective layer When it was tried to print the ink on the surface of the protective layer, it was found that the ink was repelled to make it difficult for the ink to be fixed, resulting in the occurrence of a missing portion where the ink is not formed. In particular, it has become clear that the printability tends to be inadequate when printed by pad printing.

Further, in recent years, in order to further increase the energy density of the battery and further miniaturize the battery, a further reduction in thickness of the battery packaging material is required. On the other hand, at the time of manufacturing of a battery, at the time of transportation of a product on which the battery is mounted, at the time of use, etc., a large impact may be applied to the product. At this time, a large external force may be applied to the battery packaging material containing the battery element from the inside or the outside.

Along with the demand for thinner packaging materials for batteries, thinner barriers are being considered for the barrier layer, but while aluminum foil is excellent in formability, its rigidity is low and a large external force is generated from the inside or outside of the packaging material for batteries. When it is added, a hole may be formed in the aluminum foil, and the battery element may be exposed to the outside.

In addition, in the battery manufacturing process, a masking tape is attached to the surface of the battery (that is, the surface of the battery packaging material sealing the battery element) from the viewpoint of suppressing damage to the surface of the battery. May be exfoliated before the battery is used. Also, the battery may be fixed to a housing or the like using a tape or the like, but the tape may be peeled off the surface of the battery, for example, in order to correct the position of the tape once attached. Thus, when peeling the tape from the surface of the battery, the battery packaging material follows the tape to form a wrinkle on the surface of the battery, and the wrinkle is formed by the wrinkle, and the cell comprising the battery packaging material and the positive electrode / separator / negative electrode There may be gaps between them. Then, the electrolytic solution moves from the cell to the air gap, which causes the deterioration of the battery performance, or the air gap causes the battery packaging material and the cell to be in contact when the cell is vibrated, and the battery packaging material The heat-sealable resin layer may be damaged and cause corrosion.

Under such circumstances, the present invention is excellent in the electrolyte resistance of the surface and the printing characteristics of the ink, and further has high rigidity, and it is difficult to form wrinkles when peeling the tape. The main purpose is to provide materials. Furthermore, another object of the present invention is to provide a method for producing the battery packaging material and a battery using the battery packaging material.

The present inventors diligently studied to solve the above-mentioned problems. As a result, it is composed of a laminate having at least a protective layer, a base material layer, a stainless steel foil, and a heat fusible resin layer in this order, from the outermost surface side of the protective layer when measured by attenuated total reflection, and the maximum value a of the absorbance wave number of infrared rays are detected from 2800 cm ^-1 in the range of 3000 cm ^-1, the maximum value of absorbance detected from 2200 cm ^-1 in the range of 2300 cm ^-1 By satisfying the relationship of 0.05 ≦ B / A ≦ 0.75 with B, not only the electrolytic solution resistance is excellent, but also the printing characteristics of the ink are excellent, and further, high rigidity is obtained. It has been found that it becomes a battery packaging material in which wrinkles are less likely to be formed when peeling the tape. The present invention has been completed by further studies based on these findings.

That is, the present invention provides the invention of the aspects listed below.
Item 1. It comprises a laminate having at least a protective layer, a base material layer, a stainless steel foil, and a heat fusible resin layer in this order,
Wherein when measured by attenuated total reflection Fourier transform infrared spectroscopy from the outermost surface side of the protective layer, the maximum value A of the absorbance wave number of infrared rays are detected from 2800 cm ^-1 in the range of 3000 cm ^-1, 2200 cm ^- A battery packaging material, wherein the maximum absorbance B detected in the range of ¹ to 2300 cm ^-1 satisfies the relationship of 0.05 ≦ B / A ≦ 0.75.
Item 2. The packaging material for batteries of item | item 1 in which the said protective layer contains the compound which has an isocyanate group.
Item 3. Item 1 or, wherein the protective layer comprises a urethane resin formed of at least one polyol selected from the group consisting of polyester polyols having an hydroxyl group-containing group in a side chain and an acrylic polyol, and a compound having an isocyanate group. The packaging material for batteries as described in 2.
Item 4. The battery packaging material according to any one of Items 1 to 3, which is used by printing an ink on at least a part of the surface of the protective layer.
Item 5. 5. The battery packaging material according to any one of items 1 to 4, further comprising an information carrier made of ink on at least a part of the surface of the protective layer.
Item 6. The thickness of the laminate is 45 μm or more and 120 μm or less,
The thickness of the stainless steel foil is 15 μm or more and 40 μm or less,
The battery packaging material according to any one of Items 1 to 5, wherein the bending stiffness of the laminate is 0.60 gf · cm ² / cm or more and 6.0 gf · cm ² / cm or less.
Item 7. The battery packaging material according to any one of Items 1 to 6, which has an adhesive layer between the base material layer and the stainless steel foil.
Item 8. The battery packaging material according to any one of Items 1 to 7, which has an adhesive layer between the stainless steel foil and the heat-fusible resin layer.
Item 9. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is contained in a package formed of the battery packaging material according to any one of Items 1 to 8.
Item 10. Laminating at least a protective layer, a base material layer, a stainless steel foil, and a heat fusible resin layer to obtain a laminate;
A curing step of curing the protective layer;
Equipped with
In the curing step, when measured by attenuated total reflection Fourier transform infrared spectroscopy from the outermost surface side of the protective layer, the maximum value of absorbance wave number of infrared rays are detected from 2800 cm ^-1 in the range of 3000 cm ^-1 and a, as the wave number of the infrared and the maximum value B of the absorbance detected from 2200 cm ^-1 in the range of 2300 cm ^-1, satisfy the relationship of 0.05 ≦ B / a ≦ 0.75, the protective layer Of curing the battery packaging material.

According to the present invention, there is provided a battery packaging material which is excellent in the electrolytic solution resistance of the surface and the printing characteristics of the ink, and further has high rigidity and is difficult to form wrinkles when peeling the tape. be able to. Furthermore, according to the present invention, a battery using the battery packaging material and a method of manufacturing the battery packaging material can also be provided.

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 schematic diagram for demonstrating the evaluation method of tape adhesiveness. It is a schematic diagram for demonstrating the evaluation method of tape adhesiveness. It is a schematic diagram for demonstrating the evaluation method of the tape peelability in an Example.

The battery packaging material of the present invention comprises a laminate having at least a protective layer, a base material layer, a stainless steel foil, and a heat fusible resin layer in this order, and Fourier transform from the outermost surface side of the protective layer when measured by attenuated total reflection infrared spectroscopy, and the maximum value a of the absorbance wave number of infrared rays are detected from 2800 cm ^-1 in the range of 3000 cm ^-1, detected from 2200 cm ^-1 in the range of 2300 cm ^-1 And the maximum value B of the absorbance satisfies the relationship of 0.05 ≦ B / A ≦ 0.75. Hereinafter, the battery packaging material of the present invention, the method for producing the battery packaging material, and the battery using the battery packaging material will be described in detail.

In the present specification, with regard to 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 comprises at least a protective layer 6, a base layer 1, a stainless steel foil 3 and a heat fusible resin layer 4 as shown in FIG. 1 and FIG. In the order listed. In the battery packaging material of the present invention, the protective layer 6 is the outermost layer, and the thermally fusible resin layer 4 is the innermost layer. That is, when assembling the battery, the battery element is sealed by sealing the battery element by thermally fusing the heat-fusible resin layers 4 located on the peripheral edge of the battery element.

In the battery packaging material of the present invention, as shown in FIG. 1, an adhesive layer 2 is provided between the base material layer 1 and the stainless steel foil 3 as needed for the purpose of enhancing the adhesiveness thereof. It may be In addition, as shown in FIG. 2, an adhesive layer 5 may be provided between the stainless steel foil 3 and the heat-fusible resin layer 4 as necessary for the purpose of enhancing the adhesiveness thereof.

The thickness of the laminate constituting the battery packaging material of the present invention is not particularly limited, but it has high rigidity while being a thin battery packaging material and it is difficult to form wrinkles when peeling the tape From the viewpoint of forming a battery packaging material, preferably about 45 to 120 μm is mentioned. When the battery packaging material of the present invention is so thin, the energy density of the battery can be increased.

The thickness of the laminate constituting the battery packaging material of the present invention is a thin battery packaging material, and has high rigidity, and it is difficult to form wrinkles when peeling off the tape. In view of the above, the lower limit is preferably about 45 μm or more, more preferably about 50 μm or more, and the upper limit is preferably about 120 μm or less, preferably about 91 μm or less, preferably about 86 μm or less, more preferably About 82 micrometers or less are mentioned. The preferred range of the thickness of the laminate is about 50 to 120 μm, about 55 to 120 μm, about 45 to 91 μm, about 45 to 86 μm, about 45 to 82 μm, about 50 to 91 μm, about 50 to 86 μm, about 50 to 82 μm And about 55 to 91 μm, about 55 to 86 μm, and about 55 to 82 μm. In addition, the thickness of the laminated body which comprises the packaging material 10 for batteries can be measured using a commercially available thickness measuring device.

The bending stiffness of the laminate constituting the battery packaging material of the present invention is preferably in the range of 0.60 to 6.0 gf · cm ² / cm. By setting the bending stiffness of the laminate constituting the battery packaging material of the present invention within such a specific range, excellent formability can be exhibited, and further, when the tape is peeled off Can further effectively suppress the formation of wrinkles.

From the viewpoint of exerting excellent formability while reducing the thickness of the battery packaging material and further suppressing formation of wrinkles more effectively when peeling the tape, the lower limit of the bending stiffness is as follows: Preferably, it is about 0.60 gf · cm ² / cm or more, more preferably about 0.65 gf · cm ² / cm or more, still more preferably about 0.70 gf · cm ² / cm or more, still more preferably about 0.80 gf · cm ^And the upper limit thereof is preferably about 6.0 gf · cm ² / cm or less, more preferably about 1.60 gf · cm ² / cm or less, still more preferably about 1.55 gf ··. cm ² / cm or less can be mentioned. As a preferable range of the bending stiffness, about 0.60 to 6.0 gf · cm ² / cm, about 0.65 to 6.0 gf · cm ² / cm, about 0.70 to 6.0 gf · cm ² / cm , About 0.80 to 6.0 gf · cm ² / cm, about 0.60 to 1.55 gf · cm ² / cm, about 0.65 to 1.60 gf · cm ² / cm, about 0.65 to 1.55 gf · Cm ² / cm, about 0.70 to 1. 60 gf · cm ² / cm, about 0.70 to 1.55 gf · cm ² / cm, about 0.80 to 1. 60 gf · cm ² / cm, 0 There may be about 80 to 1.55 gf · cm ² / cm.

The bending stiffness of the laminate constituting the battery packaging material 10 can be adjusted, for example, by the thickness, composition, and the like of the layers constituting the laminate.

In the present invention, the method of measuring the bending stiffness of the laminate constituting the battery packaging material is as follows. Specifically, it can be measured by the method described in the examples.

<Measurement of bending stiffness>
The battery packaging material is cut into a rectangle (width perpendicular to the flow direction during film formation: TD) 80 mm and length (flow direction during film formation: MD 100 mm) to obtain a test sample. The obtained test sample is obtained. The bending stiffness (gf · cm ² / cm) is measured using a commercially available bending stiffness tester under the following conditions: curvature change rate: 0.1 / cm · sec, clamping distance: 1 cm, maximum curvature The average value of the bending stiffness for 10 test samples is 2.5 cm ^-1 , and the average value of the bending stiffness is taken as the bending stiffness of the battery packaging material, so that the 80 mm wide edge of the test sample coincides with the clamp axial direction. Fasten to 2 clamps.

From the viewpoint of exerting excellent formability while reducing thickness of the battery packaging material and further suppressing formation of wrinkles more effectively when peeling off the tape, the battery packaging material of the present invention The layered product preferably has a puncture strength of at least 15 N when pierced from the side of the base material layer measured by a method according to JIS Z 1 707: 1997, and is in the range of 15 to 60 N It is more preferable that

In the present invention, the method of measuring the puncture strength of the laminate constituting the battery packaging material 10 is as follows. Specifically, it can be measured by the method described in the examples.

<Measurement of piercing strength>
The puncture strength from the base material layer side of the laminate constituting the battery packaging material is measured by the method according to the definition of JIS Z1707: 1997. Specifically, in a measurement environment of 23 ± 2 ° C. and relative humidity (50 ± 5)%, a test piece is fixed with a stand of 115 mm in diameter having a 15 mm opening at the center and a pressing plate, diameter 1.0 mm, A semicircular needle with a tip shape radius of 0.5 mm is pierced at a speed of 50 ± 5 mm per minute, and the maximum stress until the needle penetrates is measured. The number of test pieces is five, and the average value is determined. When the number of test pieces is insufficient and five can not be measured, the measurable number is measured, and the average value is determined.

In addition, as a tape which fixes a battery to a housing etc., for example, as a pressure-sensitive adhesive component, a rubber-based component, an acrylic-based component, a urethane-based component, a silicone-based component and a styrene-isoprene block copolymer (SIS) -based component The adhesive tape used is mentioned, and such an adhesive tape is easily commercially available.

2. Composition of each layer forming the battery packaging material [Protective layer 6]
In the battery packaging material of the present invention, a protective layer 6 is provided for the purpose of improving the electrolyte resistance and the printing characteristics of the ink. The protective layer 6 is a layer located on the outermost layer (opposite to the heat fusible resin layer) when the battery is assembled.

In the present invention, attenuated total reflection Fourier transform infrared (FT-IR) spectroscopy from the outermost surface side of the protective layer; when measured at (ATR Attenuated Total Reflection), 3000cm wave number of infrared ray from 2800 cm ^{-1 -} and the maximum value a of the absorbance is detected in ^one of the ranges, the maximum value B of the absorbance wave number of infrared rays are detected from 2200 cm ^-1 in the range of 2300 cm ^-1 is, 0.05 ≦ B / a ≦ 0.75 Satisfy the relationship. The maximum value of absorbance in the present invention is the maximum value of absorbance measured by attenuated total reflection in Fourier transform infrared spectroscopy, and is measured as the number of integrations 32 times and wave number resolution 4 cm ⁻¹ .

The maximum value of the absorbance detected in the infrared wave number range of 2800 cm ^-1 to 3000 cm ^-1 mainly represents the maximum value of the absorbance due to the C—H stretching vibration. The maximum value of absorbance wave number of infrared rays are detected from 2200 cm ^-1 in the range of 2300 cm ^-1 mainly represents the maximum value of the absorbance derived from N = C = O stretching vibration. Specific measurement conditions of attenuated total reflection in Fourier transform infrared spectroscopy are as follows. The "range from 2800 cm ^-1 3000 cm ^-1" includes 2800 cm ^-1 and 3000 cm ^-1, the "range of 2200 cm ^-1 in 2300 cm ^-1", the include 2200 cm ^-1 and 2300 cm ^-1 Be

(Measurement conditions of attenuated total reflection by Fourier transform infrared spectroscopy)
Prism: Germanium wave number resolution: 4 cm ^-1
Number of integrations: 32 times maximum of absorbance A: A baseline is taken by connecting wave numbers 2750 to 3100 cm ^-1 with a straight line, and the maximum intensity absorbance up to the maximum value of absorbance at the baseline and wave number range of 2800 to 3000 cm ^-1 Value B: A baseline is drawn by connecting a wave number of 2000 to 2500 cm ^-1 with a straight line, and the intensity to the maximum value of the absorbance at the baseline and the wave number range of 2200 to 2300 cm ^-1

Fourier transform was measured by attenuated total reflection infrared spectroscopy, absorption by C-H stretching vibration wave number of the infrared rays are detected from 2800 cm ^-1 in the range of 3000 cm ^-1 is mainly formed of the protective layer 6 It originates in the resin (main agent that reacts with the curing agent). Further, absorption by N = C = O stretching vibration wave number of the infrared rays are detected from 2200 cm ^-1 in the range of 2300 cm ^-1 is mainly due to the compound having an isocyanate group (curing agent). That is, the protective layer 6 preferably contains a compound having an isocyanate group (for example, a part of the compound having an isocyanate group used as a curing agent remains without reacting with the main agent). The protective layer 6 is preferably formed of at least one polyol (main agent) selected from the group consisting of a polyester polyol having an hydroxyl group in the side chain and an acrylic polyol, and a compound having an isocyanate group. It contains urethane resin. For example, in the battery packaging material of the present invention, by leaving a predetermined amount of unreacted isocyanate group of the curing agent, not only the electrolytic solution resistance by the protective layer 6 is improved, but also on the surface of the protective layer 6 The ink is easily fixed and the printing characteristics of the ink are further improved.

From the viewpoint of further improving the electrolytic solution resistance of the battery packaging material of the present invention and the printing characteristics of the ink, the maximum value A of the absorbance and the maximum value B of the absorbance satisfy 0.10 ≦ B / A ≦ 0. It is preferable to satisfy 70 relationships. Further, from the viewpoint of improving the abrasion resistance in addition to the electrolytic solution resistance and the printing characteristics of the ink, the maximum value A of the absorbance and the maximum value B of the absorbance satisfy 0.10 ≦ B / A ≦ 0.60. It is particularly preferred to satisfy the relationship

In the battery packaging material of the present invention, the resin (main agent that reacts with the curing agent) that forms the protective layer 6 includes a functional group (for example, hydroxyl group, amino group) that reacts with the later-described isocyanate group-containing compound (curing agent). And the like, and examples thereof include polyol compounds such as polyester polyols and acrylic polyols.

Examples of polyester polyols include polyester polyols obtained by reacting one or more kinds of dibasic acids with one or more kinds of compounds having three or more hydroxyl groups. The unreacted part of the hydroxyl groups of the compound having three or more hydroxyl groups becomes the hydroxyl group of the side chain of the polyester polyol.

Examples of dibasic acids include aliphatic dibasic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and brassic acid; isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid and the like Aromatic dibasic acids and the like.

Examples of the compound having three or more hydroxyl groups include hexanetriol, trimethylolpropane, pentaerythritol and the like.

Moreover, the polyester polyol may be added to the compound having three or more of the dibasic acid and the hydroxyl group, and a compound in which a diol is reacted may be used as needed. Examples of the diol include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, etc .; cyclohexanediol, Alicyclic diols such as hydrogenated xylylene glycol; aromatic diols such as xylylene glycol and the like.

As an acryl polyol, the copolymer which has as a main component the repeating unit derived from (meth) acrylic acid obtained by copolymerizing at least a hydroxyl-containing acryl monomer and (meth) acrylic acid is mentioned, for example.

Examples of the hydroxyl group-containing acrylic monomer include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. As a component copolymerized with a hydroxyl group-containing acrylic monomer and (meth) acrylic acid, alkyl (meth) acrylate monomers (as an alkyl group, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group) Group, i-butyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group etc.); (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide (alkyl) Examples of the group include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group and the like), N -Alkoxy (meth) acrylamide, N, N-dialkoxy (meth) acrylamide (as an alkoxy group Amide group-containing monomers such as methoxy group, ethoxy group, butoxy group, isobutoxy group etc., N-methylol (meth) acrylamide, N-phenyl (meth) acrylamide etc; glycidyl (meth) acrylate, allyl glycidyl ether etc Glycidyl group-containing monomers; silane-containing monomers such as (meth) acryloxypropyltrimethoxysilane and (meth) acryloxypropyltriethoxysilane; and isocyanate group-containing monomers such as (meth) acryloxypropylisocyanate.

The polyol compound can be used according to the required function or performance, and one type may be used alone, or two or more types may be used in combination. The protective layer 6 formed of a polyurethane resin can be obtained by using the polyol compound (main agent) and the compound having an isocyanate group (hardening agent).

As a polyol compound, an acrylic polyol is preferable because it is more excellent in electrolytic solution resistance.

In the present invention, the resin contained in the protective layer 6 may be one in which all functional groups capable of reacting with isocyanate groups have reacted with a compound having an isocyanate group (curing agent), or the curing agent and the unreacted one. (For example, those in which the hydroxyl group of the polyol compound at least partially remains) may be included.

The curing agent having an isocyanate group is not particularly limited, and known isocyanate compounds can be used. Specific examples of isocyanate compounds include aliphatic diisocyanates such as hexamethylene diisocyanate (HMDI) and trimethylhexamethylene diisocyanate (TMDI); alicyclic diisocyanates such as isophorone diisocyanate (IPDI); xylylene diisocyanate (XDI) and the like Aromatic aliphatic diisocyanates; aromatic diisocyanates such as tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI); dimer acid diisocyanate (DDI), hydrogenated TDI (HTDI), hydrogenated Hydrogenated diisocyanates such as XDI (H6XDI), hydrogenated MDI (H12 MDI), etc .; dimers, trimers of these diisocyanate compounds, and higher molecular weight polyisos Aneto like; polyhydric alcohols or water, such as trimethylol propane, or the like adduct of a low molecular weight polyester resin. The curing agent may be used alone or in combination of two or more.

The method for forming the protective layer 6 is not particularly limited. For example, a resin composition containing a main agent and a curing agent having an isocyanate group is coated on one surface of the base layer 1, and heating, light irradiation, etc. And a method of curing a part of the curing agent.

The thickness of the protective layer 6 is not particularly limited, but is preferably about 0.5 to 10 μm, more preferably about 1 to 5 μm from the viewpoint of further improving the electrolyte resistance and the printing characteristics of the ink. .

The protective layer 6 may contain an additive. Examples of the additive include fine particles having a particle diameter of about 0.5 nm to 5 μm. The material of the additive is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, and organic substances. Further, the shape of the additive is not particularly limited, and examples thereof include spheres, fibers, plates, indeterminate shapes, and balloons. As an additive, specifically, talc, silica, graphite, kaolin, montmorrroid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high Melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel and the like can be mentioned. These additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate and titanium oxide are preferably mentioned from the viewpoint of dispersion stability and cost. In addition, the surface may be subjected to various surface treatments such as insulation treatment, high dispersion treatment, and the like.

The content of the additive in the protective layer 6 is not particularly limited, but preferably about 5 to 30% by mass, more preferably about 5 to 20% by mass.

Further, in the step of fixing the battery to a protective case made of plastic or the like, the step of fixing the battery packaging material and the protective case with an adhesive tape is carried out. By adding an additive (for example, a filler such as silica particles) to the protective layer 6 and making the surface of the protective layer 6 uneven, the adhesion area of the adhesive tape and the protective layer 6 increases, and the battery packaging material and the protective case There is an advantage that fixation of can be made more rigid.

In the battery packaging material of the present invention, the ink can be suitably printed on at least a part of the surface of the protective layer 6. That is, in the battery packaging material in which the ink is printed on the surface of the protective layer 6 in the present invention, the ink (cured product of ink, dried product, etc.) printed on the surface of the protective layer 6 is exposed. The printed ink can form an information carrier by printing, for example, a bar code, a pattern, characters and the like. At least a part of the surface of the protective layer 6 may be provided with an information carrier made of ink. The ink used for printing is not particularly limited, and any known ink can be used. For example, a photocurable ink which is cured by irradiation with ultraviolet light, an inkjet ink used for an ink jet printer, etc. It can be used. The ink usually contains a component having a functional group that reacts with an isocyanate group such as a hydroxyl group or an amino group.

[Base material layer 1]
In the battery packaging material of the present invention, the base material layer 1 is a layer located between the protective layer 6 and the stainless steel foil 3.

About the raw material which forms the base material layer 1, it does not restrict | limit in particular that it is what is provided with insulation. Examples of the material for forming the base material layer 1 include polyester, polyamide, epoxy resin, acrylic resin, fluorine resin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and mixtures and copolymers thereof. It can be mentioned.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolymer polyester having ethylene terephthalate as the main component of the repeating unit, and butylene terephthalate as the main component of the repeating unit. Copolymerized polyesters and the like. Further, as a copolymerized polyester having ethylene terephthalate as the main component of the repeating unit, specifically, a copolymer polyester in which ethylene terephthalate is polymerized as the main component of the repeating unit with ethylene isophthalate (hereinafter, polyethylene (terephthalate / isophthalate) Polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) And polyethylene (terephthalate / decanedicarboxylate). Further, as a copolymerized polyester having butylene terephthalate as the main component of the repeating unit, specifically, a copolymer polyester in which butylene terephthalate is polymerized with butylene isophthalate as the main component of the repeating unit (hereinafter, polybutylene (terephthalate / isophthalate) And polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate and the like. These polyesters may be used alone or in combination of two or more. Polyester has an advantage that it is excellent in electrolytic solution resistance and is less likely to be whitened due to adhesion of the electrolytic solution, and is suitably used as a forming material of the base material layer 1.

Further, as polyamides, specifically, aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamide such as nylon 6 I, nylon 6 T, nylon 6 IT, nylon 6 I 6 T (I is isophthalic acid, T represents terephthalic acid) containing constitutional units derived from An aromatic polyamide such as pamide (MXD6); an alicyclic polyamide such as polyaminomethylcyclohexyl adipamide (PACM 6); and a copolymer of a lactam component and an isocyanate component such as 4,4'-diphenylmethane diisocyanate. Polya De, copolymerized polyamide and polyester and a copolymer of a polyalkylene ether glycol polyester amide copolymer and polyether ester amide copolymers; and copolymers thereof. These polyamides may be used alone or in combination of two or more. The stretched polyamide film is excellent in stretchability, can prevent the occurrence of whitening due to resin cracking of the base material layer 1 at the time of molding, and is suitably used as a forming material of the base material layer 1.

The base material layer 1 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, in particular a biaxially stretched resin film, is suitably used as the substrate layer 1 because its heat resistance is improved by orientation crystallization. In addition, the base material layer 1 may be formed by coating the above-described material on the stainless steel foil 3.

Among these, as a resin film which forms the base material layer 1, Preferably nylon, polyester, More preferably, biaxially stretched nylon, biaxially stretched polyester, Especially preferably biaxially stretched nylon is mentioned.

The thickness of the base material layer 1 may be, for example, about 3 to 20 μm. More specifically, when the base material layer 1 is made of polyamide such as nylon, the thickness of the base material layer 1 is preferably about 3 to 20 μm, more preferably about 10 to 15 μm. When the substrate layer 1 is made of polyester such as polyethylene terephthalate, the thickness of the substrate layer 1 is preferably about 3 to 15 μm, more preferably about 3 to 10 μm.

[Adhesive layer 2]
In the battery packaging material of the present invention, the adhesive layer 2 is a layer provided as needed in order to bond the base material layer 1 and the stainless steel foil 3.

The adhesive layer 2 is formed of an adhesive that can bond the base material layer 1 and the stainless steel foil 3. The adhesive used to form the adhesive layer 2 may be a two-part curable adhesive, or may be a one-part curable adhesive. Furthermore, the adhesion mechanism of the adhesive used to form 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 heat pressure type, and the like.

Specific examples of the resin component of the adhesive that can be used to form the adhesive layer 2 include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, copolyester, etc. Polyether-based adhesive; Polyurethane-based adhesive; Epoxy-based resin; Phenolic resin; Polyamide-based resin such as nylon 6, nylon 66, nylon 12, copolymerized polyamide; Polyolefin, acid-modified polyolefin, metal-modified polyolefin, etc. Polyolefin resins; Polyvinyl acetate resins; Cellulose adhesives; (Meth) acrylic resins; Polyimide resins; Urea resins, amino resins such as melamine resins; Chloroprene rubber, Nitrile rubber Silicone resin; - styrene rubbers such as butadiene rubber, such as fluorinated ethylene propylene copolymer. These adhesive components may be used alone or in combination of two or more. The combination mode of two or more adhesive components is not particularly limited, but, for example, as the adhesive component, a mixed resin of a polyamide and an acid-modified polyolefin, a mixed resin of a polyamide and a metal-modified polyolefin, a polyamide and a polyester, Examples thereof include mixed resins of polyester and acid-modified polyolefin, and mixed resins of polyester and metal-modified polyolefin. Among them, the ductility, durability under high humidity conditions and yellowing suppression action, thermal degradation suppressing action during heat sealing, etc. are excellent, and the laminate strength between the base material layer 1 and the stainless steel foil 3 is lowered. From the viewpoint of suppressing the generation of delamination effectively, it is preferable to use a polyurethane-based two-component curable adhesive; polyamide, polyester, or a blend resin of these with modified polyolefin.

Also, the adhesive layer 2 may be multilayered with different adhesive components. When the adhesive layer 2 is multilayered with different adhesive components, the adhesive component disposed on the substrate layer 1 side is used as a base from the viewpoint of improving the lamination strength of the base material layer 1 and the stainless steel foil 3 It is preferable to select a resin that is excellent in adhesion to the layer 1 and to select an adhesive component that is excellent in adhesiveness to the stainless steel foil 3 as the adhesive component disposed on the stainless steel foil 3 side. When the adhesive layer 2 is multilayered with different adhesive components, specifically, as an adhesive component disposed on the stainless steel foil 3 side, preferably, acid-modified polyolefin, metal-modified polyolefin, polyester and acid-modified A mixed resin with a polyolefin, a resin containing a copolyester, etc. may be mentioned.

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

For example, as a specific example of the inorganic pigment, preferably, carbon black, titanium oxide and the like can be mentioned. Moreover, as a specific example of the pigment of an organic type, Preferably an azo pigment, a phthalocyanine pigment, a condensation polycyclic pigment etc. are mentioned. Examples of azo pigments include soluble pigments such as watching red and carmine 6C; insoluble azo pigments such as monoazo yellow, disazo yellow, pyrazolone orange, pyrazolone red and permanent red, and examples of phthalocyanine pigments include copper phthalocyanine pigments, no Blue-based pigments and green-based pigments as metal phthalocyanine pigments may be mentioned, and as condensed polycyclic pigments, dioxazine violet, quinacridone violet etc. may be mentioned. In addition, as pigments, pearl pigments, fluorescent pigments and the like can be used.

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

The average particle size of the pigment is not particularly limited, and, for example, 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 by laser diffraction / scattering type particle diameter distribution measuring apparatus.

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

A colored layer may be provided between the base material layer 1 and the adhesive layer 2. The colored layer can be formed, for example, by applying an ink containing a colorant to the surface of the base layer 1. As the colorant, known ones such as pigments and dyes can be used. Moreover, only one type of colorant may be used, or two or more types may be mixed and used. In addition, as a specific example of the coloring agent contained in a colored layer, the same thing as what was illustrated in the column of [adhesive layer 2] is illustrated. The ink for forming the colored layer is not particularly limited, and known inks can be used. Specific examples of the ink include, for example, an ink containing a colorant, a diamine, a polyol, and a curing agent. In addition, as a solvent contained in ink, a well-known thing can be used, for example, toluene etc. are mentioned.

The thickness of the adhesive layer 2 is, for example, about 2 to 10 μm, preferably about 3 to 5 μm.

[Stainless steel foil 3]
In the battery packaging material of the present invention, the stainless steel foil 3 is a layer which functions as a barrier layer for preventing water vapor, oxygen, light and the like from invading the inside of the battery in addition to the strength improvement of the battery packaging material. is there.

Examples of the stainless steel foil 3 include austenitic stainless steel foil and ferritic stainless steel foil. In the present invention, the stainless steel foil 3 is an austenitic stainless steel from the viewpoint of providing a battery packaging material having high rigidity and being difficult to form wrinkles when peeling the tape and further having excellent formability. Preferably, it is made of steel.

Specific examples of austenitic stainless steel constituting the stainless steel foil 3 include SUS304, SUS301, SUS316L, etc. Among them, for batteries having high piercing strength and excellent electrolyte resistance and formability From the viewpoint of forming a packaging material, SUS304 is particularly preferable.

The thickness of the stainless steel foil 3 is not particularly limited, but from the viewpoint of making the packaging material for a battery thinner, it has a high piercing strength and is excellent in electrolyte resistance and formability. From the above, it is preferably 40 μm or less, more preferably about 10 to 40 μm, more preferably about 10 to 30 μm, and still more preferably about 15 to 25 μm.

The stainless steel foil 3 is subjected to chemical conversion treatment on at least one surface, preferably at least the surface on the side of the heat-fusible resin layer 4, and more preferably on both surfaces, for stabilization of adhesion, prevention of dissolution and corrosion, etc. Is preferred. Here, the chemical conversion treatment is a treatment for forming an acid resistant film on the surface of the stainless steel foil 3. The chemical conversion treatment is, for example, chromate treatment using a chromium compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromium acetate, acetyl acetate, chromium chloride, potassium chromium sulfate, etc .; phosphoric acid Phosphoric acid treatment using phosphoric acid compounds such as sodium, potassium phosphate, ammonium phosphate, polyphosphoric acid and the like; using an aminated phenol polymer consisting of repeating units represented by the following general formulas (1) to (4) Chromate treatment etc. are mentioned. In the aminated phenol polymer, repeating units represented by the following general formulas (1) to (4) may be contained singly or in any combination of two or more. It is also good.

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

Moreover, as a chemical conversion treatment method for imparting corrosion resistance to stainless steel foil 3, a coating in which fine particles of metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide or barium sulfate are dispersed in phosphoric acid is coated And a method of forming a corrosion resistant treatment layer on the surface of the stainless steel foil 3 by baking at about 150 ° C. or higher. In addition, on the corrosion-resistant layer, a resin layer may be formed by crosslinking the cationic polymer with a crosslinking agent. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, primary amine grafted acrylic resin having a primary amine grafted on an acrylic main skeleton, polyallylamine or Its derivatives, aminophenol and the like can be mentioned. These cationic polymers may be used alone or in combination of two or more. Moreover, as a crosslinking agent, the compound which has an at least 1 sort (s) of functional group chosen from the group which consists of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent etc. are mentioned, for example. These crosslinking agents may be used alone or in combination of two or more.

In these chemical conversion treatments, one type of chemical conversion treatment may be performed alone, or two or more types of chemical conversion treatments may be performed in combination. Furthermore, these chemical conversion treatments may be performed using one type of compound alone, or may be performed using two or more types of compounds in combination. Among these, preferred is a chromic acid treatment, more preferably a chemical conversion treatment in which a chromium compound, a phosphoric acid compound, and an aminated phenol polymer are combined. Among the chromium compounds, chromic acid compounds are preferred.

The amount of the acid resistant coating formed on the surface of the stainless steel foil 3 in the chemical conversion treatment is not particularly limited, but may be, for example, the case where chromate treatment is performed by combining a chromic acid compound, a phosphoric acid compound, and an aminated phenol polymer. For example, the chromic acid compound is about 0.5 to 50 mg, preferably about 1.0 to 40 mg, in terms of chromium, and the phosphorus compound is about 0.5 to 50 mg, preferably in terms of phosphorus, per 1 m ² of the surface of stainless steel foil 3 It is desirable that about 1.0 to 40 mg and an aminated phenolic polymer be contained at a ratio of about 1 to 200 mg, preferably about 5.0 to 150 mg.

The chemical conversion treatment is performed by applying a solution containing a compound used to form an acid-resistant film on the surface of the stainless steel foil 3 by a bar coating method, a roll coating method, a gravure coating method, an immersion method, etc. The heating temperature is about 70 to 200.degree. C. In addition, before the stainless steel foil 3 is subjected to the chemical conversion treatment, the stainless steel foil 3 may be subjected in advance to a degreasing treatment by an alkaline immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method or the like. By performing the degreasing treatment as described above, the chemical conversion treatment of the surface of the stainless steel foil 3 can be performed more efficiently.

[Heat-fusible resin layer 4]
In the battery packaging material of the present invention, the thermally fusible resin layer 4 corresponds to the innermost layer, and is a layer that thermally fuses the thermally fusible resin layers when the battery is assembled to seal the battery element.

The resin component used for the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-fused, but examples include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins. Be That is, the resin constituting the heat-fusible resin layer 4 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The resin constituting the heat-fusible resin layer 4 can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, etc., as long as it contains a polyolefin skeleton, 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 denaturation degree is low, the peak may be small and not detected. In that case, analysis is possible by nuclear magnetic resonance spectroscopy.

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

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

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

The carboxylic acid-modified cyclic polyolefin is obtained by copolymerizing part of the monomers constituting the cyclic polyolefin with an α, β-unsaturated carboxylic acid or an anhydride thereof, or α, β 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 carboxylic acid modified is the same as described above. Moreover, as carboxylic acid used for modification | denaturation, it is the same as that used for modification | denaturation of the said carboxylic acid modified polyolefin.

Among these resin components, preferred are carboxylic acid-modified polyolefins; more preferred are carboxylic acid-modified polypropylenes.

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

In the battery packaging material of the present invention, the heat-fusible resin layer 4 may contain a lubricant. The lubricant is not particularly limited, but preferably includes amide lubricants. The amide-based lubricant is not particularly limited as long as it has an amide group, and preferably includes fatty acid amides and aromatic bisamides. The lubricant may be used alone or in combination of two or more.

Examples of fatty acid amides include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides and the like. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic 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. In addition, specific examples of methylolamide include methylol stearic acid amide and the like. Specific examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylene bisstearin Acid amide, hexamethylene bisbehenamide, hexamethylene hydroxystearic amide, N, N'-distearyl adipamide, N, N'-distearyl sebacate amide and the like can be mentioned. Specific examples of unsaturated fatty acid bisamides include ethylene bis oleic acid amide, ethylene bis erucic acid amide, hexamethylene bis oleic acid amide, N, N'-dioleyl adipic acid amide, N, N'-dioleyl sebacic acid amide Etc. Specific examples of fatty acid ester amides include stearoamidoethyl stearate and the like. Further, specific examples of the aromatic bisamides include m-xylylene bis-stearic acid amide, m-xylylene bis-hydroxystearic acid amide, N, N'-distearyl isophthalic acid amide and the like.

When the heat-fusible resin layer 4 contains a lubricant, the content thereof may be appropriately selected, but is preferably about 700 to 1200 ppm, more preferably about 800 to 1100 ppm. In the present invention, the content of the lubricant in the heat fusible resin layer 4 is the content of the lubricant present inside the heat fusible resin layer 4 and the lubricant present in the surface of the heat fusible resin layer 4. It is a total amount.

The thickness of the heat-fusible resin layer 4 can be appropriately selected, and may be about 10 to 40 μm, preferably about 15 to 30 μm.

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

The adhesive layer 5 is formed of a resin capable of adhering the stainless steel foil 3 and the heat fusible resin layer 4. As resin used for formation of adhesion layer 5, the thing of the adhesion mechanism, the kind of adhesive agent component, etc. can be used for the adhesive agent illustrated by adhesive agent layer 2, and the like. Moreover, as resin used for formation of the contact bonding layer 5, polyolefin resin, such as polyolefin mentioned above-mentioned heat-fusion resin layer 4, cyclic polyolefin, carboxylic acid modified polyolefin, carboxylic acid modified cyclic polyolefin, can also be used. . As the polyolefin, a carboxylic acid-modified polyolefin is preferable, and a carboxylic acid-modified polypropylene is particularly preferable, from the viewpoint of excellent adhesion between the stainless steel foil 3 and the heat sealable resin layer 4. That is, the resin constituting the adhesive layer 5 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. It is possible to analyze that the resin constituting the adhesive layer 5 contains a polyolefin skeleton, for example, by infrared spectroscopy, gas chromatography mass spectrometry, etc., and there is no particular limitation on the analysis method. 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 denaturation degree is low, the peak may be small and not detected. In that case, analysis is possible by nuclear magnetic resonance spectroscopy.

Furthermore, from the viewpoint of making the battery packaging material excellent in moldability while reducing the thickness of the battery packaging material, the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. Is also preferred. As the acid-modified polyolefin, preferably, the same ones as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat fusible resin layer 4 can be exemplified.

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

The epoxy curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of the epoxy curing agent include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether and the like.

The polyfunctional isocyanate-based curing agent is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate-based curing agents include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), those obtained by polymerizing or nurifying these, and mixtures thereof And copolymers with other polymers.

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 a carbodiimide type | system | group hardening | curing agent, the polycarbodiimide compound which has a carbodiimide group 2 or more at least is preferable.

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

From the viewpoint of, for example, enhancing the adhesion between the stainless steel foil 3 and the heat sealable resin layer 4 by the adhesive layer 5, the curing agent may be composed of two or more types of compounds.

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

The thickness of the adhesive layer 5 is not particularly limited as long as it exhibits the function as an adhesive layer, but when using the adhesive exemplified in the adhesive layer 2, it is preferably about 2 to 10 μm, more preferably 2 to 10 There is about 5 μm. Further, in the case of using the resin exemplified for the heat fusible resin layer 4, it is preferably about 2 to 30 μm, more preferably about 10 to 20 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, it is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, and still more preferably about 0.5 to 5 μm. 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.

3. Method for Producing Battery Packaging Material The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate obtained by laminating each layer of a predetermined composition is obtained. That is, in the battery packaging material of the present invention, at least a protective layer, a base material layer, a stainless steel foil, and a heat-fusible resin layer are laminated to obtain a laminate, and the protective layer is cured. And, in the curing step, the infrared wave number is in the range of 2800 cm.sup.- ¹ to 3000 cm.sup.- ¹ as measured by attenuated total reflection from the outermost surface side of the protective layer by Fourier transform infrared spectroscopy. sufficiency and the detected absorbance maximum value a of the maximum value B of the absorbance wave number of infrared rays are detected from 2200 cm ^-1 in the range of 2300 cm ^-1 is a relation 0.05 ≦ B / a ≦ 0.75 As an example, a method of curing the protective layer is exemplified. Specifically, for example, it can be manufactured as follows.

First, a laminate (hereinafter sometimes referred to as “laminate A”) in which at least the base material layer 1 and the stainless steel foil 3 are sequentially laminated is formed. The laminate A is formed, for example, by a gravure coating method using an adhesive used for forming the adhesive layer 2 on the base material layer 1 or on the stainless steel foil 3 whose surface has been subjected to a chemical conversion treatment as needed. It can carry out by the dry lamination method which makes the stainless steel foil 3 or the substrate layer 1 concerned laminate, and hardens the adhesive layer 2 after applying and drying with application methods, such as a coating method.

Next, the heat fusible resin layer 4 is laminated on the stainless steel foil 3 of the laminate A. In the case where the heat fusible resin layer 4 is directly laminated on the stainless steel foil 3, the resin component constituting the heat fusible resin layer 4 is gravure-coated on the stainless steel foil 3 of the laminate A. It may be applied by a coating method or the like. When the adhesive layer 5 is provided between the stainless steel foil 3 and the heat fusible resin layer 4, for example, (1) the adhesive layer 5 and the heat fusible property on the stainless steel foil 3 of the laminate A Method of laminating by co-extrusion of the resin layer 4 (co-extrusion laminating method) (2) Separately, a laminated body in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated is formed. Method of laminating on the stainless steel foil 3 by thermal lamination method, (3) extruding or solution coating an adhesive for forming the adhesive layer 5 on the stainless steel foil 3 of the laminated body A, drying at high temperature and further drying A method of laminating by a method such as baking and laminating a thermally adhesive resin layer 4 previously formed into a sheet on the adhesive layer 5 by a thermal laminating method, (4) stainless steel foil 3 of a laminated body A, Heat-weldable wood pre-formed into a sheet Between the layer 4, while pouring the adhesive layer 5 was melted, and a method of bonding a laminate A and the heat-welding resin layer 4 through the adhesive layer 5 (sandwich lamination method). Next, the resin composition for forming the protective layer 6 is applied to the surface of the base layer 1, and a part of the isocyanate groups of the curing agent is reacted to cure the protective layer. As a method of reacting a part of isocyanate group of a hardening agent, heating, light irradiation, etc. are mentioned. For example, in the case of heating, by performing an aging step under an environment of about 24 to 120 hours at a temperature of about 30 to 90 ° C., the infrared ray measured by attenuated total reflection in Fourier transform infrared spectroscopy is and the maximum value a of the absorbance wavenumber is detected from 2800 cm ^-1 in the range of 3000 cm ^-1, and the maximum value B of the absorbance detected from 2200 cm ^-1 in the range of 2300cm ^-1, 0.05 ≦ B / a It can be adjusted to satisfy the relationship of ≦ 0.75. The step of forming the protective layer 6 on the surface of the base layer 1 may be performed before laminating the base layer 1 and the stainless steel foil 3. For example, after the protective layer 6 is formed on the surface of the base layer 1, the stainless steel foil 3 may be formed on the surface of the base layer 1 opposite to the protective layer 6. In addition, after laminating the base material layer 1 and the stainless steel foil 3, the protective layer 6 may be formed on the surface of the base material layer 1 before laminating the thermally fusible resin layer 4.

In the battery packaging material of the present invention, each layer constituting the laminate improves or stabilizes film forming ability, lamination processing, final product secondary processing (pouching, embossing) suitability, etc., as necessary. For this purpose, surface activation treatments such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

Furthermore, in the battery packaging material of the present invention, before or after molding the battery packaging material (forming for forming a space for sealing the battery element), or before or after housing the battery element after molding, The ink may be printed on the surface of the protective layer 6. Although it does not restrict | limit especially as a printing method, When printing is performed to the packaging material for batteries after shaping | molding, pad printing is preferable. The battery packaging material obtained by the manufacturing method of the present invention has an infrared wavenumber of 2800 cm.sup.- ¹ to 3000 cm.sup.- ¹ when measured by attenuated total reflection of Fourier transform infrared spectroscopy from the outermost surface side of the protective layer 6. and the maximum value a of the absorbance is detected in the range, the maximum value B of the absorbance detected from 2200 cm ^-1 in the range of 2300 cm ^-1 is a certain relationship 0.05 ≦ B / a ≦ 0.75 sufficiency Therefore, the ink can be suitably printed even by pad printing in which the ink is easily repelled. Therefore, on at least a part of the surface of the protective layer 6, for example, printing of a bar code, a handle, characters and the like can be suitably formed. The ink used for printing is as described above.

4. Applications of Battery Packaging Material The battery packaging material of the present invention is used to form a package for sealing and housing battery elements such as a positive electrode, a negative electrode, and an electrolyte. That is, the battery element can be accommodated in a package formed of the battery packaging material of the present invention.

Specifically, the battery element provided with at least a positive electrode, a negative electrode, and an electrolyte is covered with the metal terminal connected to each of the positive electrode and the negative electrode using the package formed of the battery packaging material of the present invention. In a state in which the flange portion (area in which the heat fusible resin layers are in contact) can be formed on the periphery of the battery element, and the heat fusible resin layers of the flange portion are heat sealed Sealing provides a battery using the battery packaging material. In addition, when accommodating a battery element using the battery packaging material of this invention, it is used so that the heat fusible resin part of the battery packaging material of this invention may become inside (surface which contacts a battery element).

Since the battery packaging material of the present invention is used in the battery of the present invention, for example, the battery packaging material of the present invention is preferably molded, and is also suitable for the surface of the battery after the battery element is sealed. The ink can be printed, and the information carrier can be suitably formed on at least a part of the surface of the battery, for example, by printing a bar code, a handle, characters and the like.

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, lithium ion battery, lithium ion polymer battery, lead storage battery, nickel hydrogen storage battery, nickel cadmium storage battery, nickel Iron storage batteries, nickel-zinc storage batteries, silver oxide-zinc storage batteries, metal air batteries, multivalent cation batteries, capacitors, capacitors and the like can be mentioned. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are mentioned as a suitable application object of the packaging material for batteries of the present invention.

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

<Manufacture of battery packaging materials>
Example 1-3 and Comparative Examples 1 and 2
On the base material layer 1 made of a stretched nylon film (ONY), a barrier layer made of stainless steel foil (SUS) subjected to chemical conversion treatment on both sides was laminated by a dry lamination method. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) is applied to one surface of a stainless steel foil to form an adhesive layer 2 (3 μm thick) on the stainless steel foil 3 did. Then, the adhesive layer 2 and the base material layer 1 on the stainless steel foil 3 are bonded by pressure heating, and then an aging process is performed to laminate the base material layer 1 / adhesive layer 2 / stainless steel foil 3 The body was prepared. The chemical conversion treatment of stainless steel foil is carried out by a roll coating method so that the coating amount of chromium is 10 mg / m ² (dry weight) of a treatment liquid composed of a phenol resin, a chromium fluoride compound and phosphoric acid. It apply | coated on both surfaces of a foil, and carried out by baking on the conditions which become 180 degreeC or more in film | membrane temperature.

Next, a two-component olefin adhesive (a resin composition containing an acid-modified polypropylene resin and an epoxy resin) was applied to the stainless steel foil 3 side of the laminate, and an adhesive layer 5 was formed on the stainless steel foil 3. Furthermore, the unstretched polypropylene film (CPP) as the heat-fusible resin layer 4 was laminated on the adhesive layer 5. Next, the obtained laminate was heated and subjected to an aging treatment. Next, on the base material layer 1, a resin composition for forming the protective layer 6 (20% by mass of polyester polyol having a hydroxyl value of 7 mg KOH / g and weight average molecular weight 15000, and aroma as a curing agent having an isocyanate group Resin composition containing 15% by mass of tolylene diisocyanate (TDI), which is an aliphatic diisocyanate curing agent, and 65% by mass of a solvent of methyl ethyl ketone by a gravure coating method to form a protective layer 6 on the surface of the substrate layer 1 (Thickness 2.5 μm). Thus, a battery packaging material comprising a laminated film in which protective layer 6 / base material layer 1 / adhesive layer 2 / stainless steel foil 3 / adhesive layer 5 / heat sealable resin layer 4 are sequentially laminated is obtained. .

In the battery packaging materials of Example 1-3 and Comparative Examples 1 and 2, aging was performed under the conditions described in Table 1 after all of the layers were laminated. The total thickness of the drawn nylon film (ONY), stainless steel foil (SUS), the adhesive layer, the heat fusible resin layer, and the laminate is as described in Table 1. In Examples 1-3 and Comparative Examples 1 and 2, SUS304 (austenitic stainless steel foil) was used as the stainless steel foil.

Examples 4-7, 13, 15 and Comparative Examples 3, 4
In Examples 4-7, 13, 15 and Comparative Examples 3, 4, the filler (silica particles having an average particle diameter of 1.0 μm) such that the proportion in the resin composition forming the protective layer 6 is 10% by mass. A battery packaging material was produced in the same manner as in Example 1-3 and Comparative Examples 1 and 2, respectively, except that the above were added. In the battery packaging materials of Examples 4-7, 13 and 15 and Comparative Examples 3 and 4, after all the layers were laminated, aging was performed under the conditions described in Table 1, respectively. The total thickness of the drawn nylon film (ONY), stainless steel foil (SUS), the adhesive layer, the heat fusible resin layer, and the laminate is as described in Table 1. In Examples 4-7 and 15 and Comparative Examples 3 and 4, SUS304 (austenitic stainless steel foil) was used as the stainless steel foil. In Example 13, SUS444 (ferritic stainless steel foil) was used as the stainless steel foil.

Examples 8-12 and 14
On the base material layer 1 which consists of a polyethylene terephthalate film (PET), the barrier layer which consists of stainless steel foil (SUS) which gave chemical conversion treatment on both surfaces was laminated by the dry lamination method. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) is applied to one surface of a stainless steel foil to form an adhesive layer 2 (3 μm thick) on the stainless steel foil 3 did. Then, the adhesive layer 2 and the base material layer 1 on the stainless steel foil 3 are bonded by pressure heating, and then an aging process is performed to laminate the base material layer 1 / adhesive layer 2 / stainless steel foil 3 The body was prepared. The chemical conversion treatment of the stainless steel foil was performed in the same manner as in Example 1-3 and Comparative Examples 1 and 2.

Next, in Examples 8, 9, 11, 12 and 14, a two-component olefin adhesive (a resin composition containing an acid-modified polypropylene resin and an epoxy resin) is applied to the stainless steel foil 3 side of the laminate. The adhesive layer 5 was formed on the stainless steel foil 3. Furthermore, the unstretched polypropylene film (CPP) as the heat-fusible resin layer 4 was laminated on the adhesive layer 5. Next, the obtained laminate was heated and subjected to an aging treatment.

In Example 10, on the stainless steel foil 3 side of the laminate, coextrusion of maleic anhydride polypropylene (PPa) as the adhesive layer 5 and polypropylene (PP) as the heat fusible resin layer 4 did.

Next, as in Example 4-7 and Comparative Examples 3 and 4, a filler (silica particles having an average particle diameter of 1.0 μm) was added so that the proportion in the resin composition forming the protective layer 6 would be 10% by mass. In addition, a protective layer 6 was formed (thickness 3 μm). Thus, a battery packaging material comprising a laminated film in which protective layer 6 / base material layer 1 / adhesive layer 2 / stainless steel foil 3 / adhesive layer 5 / heat sealable resin layer 4 are sequentially laminated is obtained. .

In the battery packaging materials of Examples 8-12 and 14, after all the layers were laminated, aging was performed under the conditions described in Table 1, respectively. The total thickness of the polyethylene terephthalate film (PET), stainless steel foil (SUS), the adhesive layer, the heat fusible resin layer, and the laminate is as described in Table 1. In Examples 8-10, SUS304 (austenitic stainless steel foil) was used as the stainless steel foil. In Example 11, as stainless steel foil, SUS301 (austenitic stainless steel foil) was used. In Example 12, as stainless steel foil, SUS316L (austenitic stainless steel foil) was used. In Example 14, SUS444 (ferritic stainless steel foil) was used as the stainless steel foil.

Comparative Example 5-7 and Reference Example 1
On the base material layer 1 which consists of an oriented nylon film (ONY), the barrier layer which consists of aluminum foil (ALM) which gave chemical conversion treatment on both surfaces was laminated by the dry lamination method. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of an aluminum foil to form an adhesive layer 2 (3 μm in thickness) on the aluminum foil. Then, after bonding the adhesive layer 2 on the aluminum foil and the base layer 1 under pressure heating, an aging treatment was carried out to prepare a laminate of base layer 1 / adhesive layer 2 / aluminum foil. . The chemical conversion treatment of the aluminum foil was performed in the same manner as the chemical conversion treatment of the stainless steel foils of Example 1-3 and Comparative Examples 1 and 2.

Next, in Comparative Example 6, a two-component olefin adhesive (a resin composition containing an acid-modified polypropylene resin and an epoxy resin) is applied to the aluminum foil side of the laminate to form an adhesive layer 5 on the aluminum foil. did. Furthermore, the unstretched polypropylene film (CPP) as the heat-fusible resin layer 4 was laminated on the adhesive layer 5. Next, the obtained laminate was heated and subjected to an aging treatment.

In Comparative Examples 5 and 7 and Reference Example 1, maleic anhydride polypropylene (PPa) as the adhesive layer 5 and polypropylene (PP) as the heat-fusible resin layer 4 were formed on the aluminum foil side of the laminate. And co-extruded.

Next, as in Example 4-7 and Comparative Example 3-5, a filler (silica particles having an average particle diameter of 1.0 μm) was added so that the proportion in the resin composition forming the protective layer 6 would be 10% by mass. In addition, a protective layer 6 was formed (thickness 3 μm). Thus, a battery packaging material comprising a laminated film in which the protective layer 6 / the base material layer 1 / the adhesive layer 2 / the aluminum foil / the adhesive layer 5 / the heat fusible resin layer 4 are sequentially laminated is obtained.

In the battery packaging materials of Comparative Example 5-7 and Reference Examples 1 and 2, aging was performed under the conditions described in Table 1 after all of the layers were laminated. In addition, the total thickness of the stretched nylon film (ONY), the aluminum foil (ALM), the adhesive layer, the heat fusible resin layer, and the laminate is as described in Table 1, respectively. Further, in Comparative Examples 5-7 and Reference Examples 1 and 2, as the aluminum foil, one having a composition of JIS H4000: 2014 A8021 P-O was used.

[Measurement of B / A of Protective Layer]
The attenuated total reflection of Fourier transform infrared spectroscopy was measured from the outermost surface side of the protective layer of the battery packaging material obtained above using a Thermo Scientific Nicolet 380. Up from the obtained measurement results, the wave number of infrared ray and the maximum value A of the absorbance detected from 2800 cm ^-1 in the range of 3000 cm ^-1, wave number of infrared absorbance detected in 2300 cm ^-1 range of 2200 cm ^-1 Based on the value B, the value of B / A was calculated. The results are shown in Table 1. In the present invention, the maximum value of absorbance is the maximum value of absorbance measured by attenuated total reflection in Fourier transform infrared spectroscopy, and is measured as integration number 32 times and wave number resolution 4 cm ⁻¹ . Specific measurement conditions of attenuated total reflection in Fourier transform infrared spectroscopy are as follows.

(Measurement conditions of attenuated total reflection by Fourier transform infrared spectroscopy)
Prism: Germanium wave number resolution: 4 cm ^-1
Number of integrations: 32 times maximum of absorbance A: A baseline is taken by connecting wave numbers 2750 to 3100 cm ^-1 with a straight line, and the maximum intensity absorbance up to the maximum value of absorbance at the baseline and wave number range of 2800 to 3000 cm ^-1 Value B: A baseline is drawn by connecting a wave number of 2000 to 2500 cm ^-1 with a straight line, and the intensity to the maximum value of the absorbance at the baseline and the wave number range of 2200 to 2300 cm ^-1

[Evaluation of electrolytic solution resistance]
From the battery packaging material obtained above, a test piece of 100 mm wide and 100 mm long was cut out. Next, an electrolyte (containing 1 M of LiPF ₆ and a mixed solution of ethylene carbonate, diethyl carbonate and dimethyl carbonate (volume ratio 1: 1: 1)) is dripped on the surface of the protective layer, and the relative humidity is 24 ° C. After standing for 6 hours in a 50% environment, the electrolyte was wiped off with ethanol and the surface change was observed. At this time, the thing which did not change at all was taken as A, and the thing which was discolored was taken as C. The results are shown in Table 1.

[Evaluation of printing characteristics of ink]
Pad printing was performed on the surface of the protective layer of the battery packaging material obtained above to evaluate the printing characteristics of the ink. The pad printing machine used SPACE PAD 6GX made by Mishima Co., Ltd. Further, as the ink, UV ink PJU-A black manufactured by Navitas Co., Ltd. was used. The ink printed on the surface of the protective layer was cured by irradiation with UV for 30 seconds from a distance of 10 cm at an ultraviolet wavelength of 254 nm with a handy UV lamp SUV-4 manufactured by As One. The area of the printing surface was 100 mm ² . The printed surface after curing was observed with an optical microscope to evaluate the printing characteristics of the ink according to the following criteria. The following evaluations A and B indicate that the printing characteristics of the ink are good. The printing of the ink was performed under an environment of a temperature of 24 ° C. and a relative humidity of 50%. The results are shown in Table 1.
A: The omission of printing is less than 5% of the whole printing pattern B: The omission of printing is 5% or more and 10% or less of the whole printing pattern C: The omission of printing is more than 10% of the whole printing pattern

[Evaluation of wear resistance]
According to the method defined in JIS P 8136, the protective layer of the battery packaging material obtained above was subjected to an abrasion resistance test under the condition of 30 strokes, and the presence or absence of a scratch was visually confirmed . When the protective layer after the test was not damaged, it was evaluated as A, and when it was damaged, it was evaluated as C. The results are shown in Table 1.

[Evaluation of tape adhesion]
As shown in FIGS. 3 and 4, each battery packaging material 10 obtained above is cut out in a size of width 15 mm and length 175 mm, and a double-sided adhesive tape 20 (width 5 mm and length 125 mm) is formed on the surface of the protective layer. 3M company # 610, thickness 120 μm) was pasted. Over this, the surface of the protective layer 6 of the battery packaging material 10 cut out with a width of 15 mm and a length of 300 mm is overlapped, and the crimping device described in JIS-Z0237: 2009 adhesive tape and adhesive sheet test method 10.2.4. The battery packaging material 10 and the double-sided adhesive tape 20 were pressure-bonded using In an environment with a temperature of 24 ° C. and a relative humidity of 50%, the mass of the roller of the pressure bonding apparatus reciprocates twice at a speed of 2 kg and 10 mm / sec. After being crimped with a roller and stored for 1 hour at a temperature of 24 ° C. and a relative humidity of 50% RH, the battery packaging material 10 cut out with a width of 15 mm and a length of 300 mm was folded back at 180 ° at the end of the double-sided adhesive tape 20 The battery packaging material 10 was fixed at the top and bottom of a tensile tester, and a tensile test was performed at a temperature of 24 ° C. and a relative humidity of 50% at a peeling angle of 180 ° and a speed of 50 mm / min to evaluate tape adhesion. . The obtained peel strength was calculated as an average value excluding the first 25 mm and the last 20 mm of the measurement, and the tape adhesion was evaluated based on the criteria shown below. The results are shown in Table 1.
A: Peeling strength 5 N / 5 mm or more B: Peeling strength 3 N / 5 mm or more, less than 5 N / 5 mm C: Peeling strength 3 N / 5 mm

[Measurement of bending stiffness]
Each of the battery packaging materials obtained above is cut into a rectangle having a width (direction perpendicular to the flow direction during film formation: TD) 80 mm and a length (flow direction during film formation: MD) 100 mm. I got The bending stiffness (gf · cm ² / cm) of the obtained test sample was measured using a bending stiffness measuring machine (SMT / JTC-911BT). Measurement conditions were a curvature change rate of 0.1 / cm · sec, a clamp interval of 1 cm, and a maximum curvature of 2.5 cm ^-1, and the average value of bending stiffness for 10 test samples was obtained above. The bending stiffness of the packaging material for each battery. In addition, it fixed to two clamps so that the edge of width 80 mm of a test sample might correspond with clamp axial direction.
The evaluation criteria of bending stiffness are as follows. The results are shown in Table 1.
A: bending stiffness 6.0 gf · cm ² / cm or less, 0.60 gf · cm ² / cm or more C: bending stiffness 0.59 gf · cm ² / cm or less

[Measurement of piercing strength]
Each battery packaging material obtained above was cut into a rectangle having a width of 80 mm and a length of 120 mm to obtain a test sample. About the obtained test sample, the piercing strength was measured from the base material layer side by the method based on JISZ1707: 1997. Specifically, in a measurement environment of 23 ± 2 ° C. and relative humidity (50 ± 5)%, a test piece is fixed with a stand of 115 mm in diameter having a 15 mm opening at the center and a pressing plate, diameter 1.0 mm, A semicircular needle with a tip shape radius of 0.5 mm was pierced at a speed of 50 ± 5 mm per minute, and the maximum stress until the needle penetrated was measured. The number of test pieces was 5, and the average value was calculated. In addition, ZTS-500N (force gauge) and MX-500N (measurement stand) made by Imada Co., Ltd. were used as a measurement apparatus of piercing strength. Evaluation criteria of puncture strength are as follows. The results are shown in Table 1.
A: Penetration strength 60 N or less, 25 N or more B: Penetration strength 15 N or more, less than 25 N C: Perforation strength less than 15 N

[Measurement of critical forming depth]
Each battery packaging material obtained above was cut into a rectangle of width 90 mm and length 150 mm to obtain a test sample. Next, in an environment with a temperature of 24 ° C. and a relative humidity of 50%, using a female die having a bore of 30 mm × 50 mm and a corresponding male die, from a molding depth of 0.5 mm at a pressing pressure of 0.9 MPa. Molding was carried out by increasing the molding depth in units of 0.5 mm, and the molding depth 0.5 mm shallower than the molding depth when pinholes were generated in the battery packaging material was taken as the limit molding depth of the sample. In molding, the male mold was placed on the side of the heat fusible resin layer to form a concave portion on the heat fusible resin layer side and a convex portion on the base layer side. The clearance between male and female molds was 0.3 mm. In addition, the surface of the female die has a maximum height roughness (nominal value of Rz) of 3.2 μm as defined in Table 2 of the surface roughness standard piece for comparison in JIS B 0 656-1: 2002 Annex 1 (Reference). It is. The surface of the male mold has a maximum height roughness (nominal value of Rz) specified in Table 2 of the surface roughness standard piece for comparison in JIS B 0 656-1: 2002 Annex 1 (reference) is 1.6 μm. . The evaluation criteria for formability are as follows. The results are shown in Table 1.
A: Limit forming depth 3.0 mm or more B: Limit forming depth 2.0 mm to 2.5 mm or less C: Limit forming depth 1.5 mm or less

[Evaluation of formation of wrinkles by tape peeling]
Each of the battery packaging materials 10 obtained above is molded using a female die and a male die at a pressing pressure of 0.9 MPa in an environment with a temperature of 24 ° C. and a relative humidity of 50% to obtain the following battery sizes 1 and 2 The concave portion of the In molding, a male mold is disposed on the side of the heat fusible resin layer 4 to form a recessed portion on the heat fusible resin layer 4 side and a convex portion on the protective layer 6 side. The The clearance between male and female molds was 0.3 mm. In addition, the surface of the female die has a maximum height roughness (nominal value of Rz) of 3.2 μm as defined in Table 2 of the surface roughness standard piece for comparison in JIS B 0 656-1: 2002 Annex 1 (Reference). It is. The surface of the male mold has a maximum height roughness (nominal value of Rz) specified in Table 2 of the surface roughness standard piece for comparison in JIS B 0 656-1: 2002 Annex 1 (reference) is 1.6 μm. .
Battery size 1: Width of recess 30 mm, length 90 mm, molding depth 3 mm
Battery size 2: Width of recess 94 mm, length 128 mm, molding depth 3 mm
In Examples 8, 11, 12 and 13 in which the formability evaluation is evaluation B, the forming depth of battery size 1 and cell size 2 is 2 mm, and the formability evaluation is evaluation C in Example 14 The molding depths of the battery size 1 and the battery size 2 were respectively 1.5 mm.

Next, as shown in the schematic view of FIG. 5, an acrylic plate 21 having a width of 91 mm, a length of 125 mm, and a height of 3 mm (corresponding to the direction of molding depth) in the concave portion of the battery packaging material of battery size 2 Inserted. The inserted acrylic plate 21 was fixed using double-sided tape NO 751B manufactured by Teraoka Seisakusho Co., Ltd. so as to be in close contact with the bottom of the concave portion of the battery packaging material 10. Next, double-sided tape 31 (# 610 manufactured by 3M, 120 μm thick) and aluminum foil 41 (35 μm) with a width of 5 mm and a length of 50 mm as an adhesive tape on surface 10a of the convex part of the molded part And the double-sided tape 31 is attached to the surface 10a of the convex portion side of the molding portion of the battery packaging material 10 by making one reciprocation from the top of the aluminum foil 41 with a rubber roller of 200 g. Next, hold the end of the double-sided tape not attached to the convex part of the formed part with a finger and pull the double-sided tape 31 together with the aluminum foil 41 in the 180 ° direction (the direction of the arrow in FIG. 5). It peeled from the surface 10a of. Next, the surface of the formed portion from which the double-sided tape 31 was peeled was observed visually, and the formation of wrinkles by tape peeling was evaluated according to the following criteria. The evaluation results are shown in Table 1.
A: Since the molding portion did not follow the tape, no wrinkles were formed on the surface, and the tape was properly peeled from the surface of the battery packaging material.
C: The formed portion follows the tape, and a wrinkle is formed on the surface.

In Examples 13 and 14, SUS444 (ferritic stainless steel foil) was used as a stainless steel foil.

In Table 1, ONY is a stretched nylon film, PET is a polyethylene terephthalate film, SUS is a stainless steel foil, ALM is an aluminum foil, UR is a cured product of a two-component urethane adhesive, and OE is a cured polyolefin resin and epoxy resin. CPP means unstretched polypropylene film, PPa means maleic anhydride polypropylene, and PP means polypropylene. Moreover, the numerical value described behind the layer means the thickness (μm) of the layer, for example, “ONY10” means “stretched nylon film with a thickness of 10 μm”.

As apparent from the results shown in Table 1, in the battery packaging materials of Examples 1 to 15, the barrier layer is made of stainless steel foil, and the B / A value is 0.10 to 0.70. In addition to electrolyte resistance, the printing properties and abrasion resistance of the ink are also excellent, and the evaluation of formation of wrinkles due to bending stiffness, puncture strength, and tape peeling is also possible. It turns out that it is excellent. In addition, in the battery packaging materials of Examples 4 to 15 in which the filler is added to the resin composition forming the protective layer 6, it is understood that the tape adhesion is also excellent.

DESCRIPTION OF SYMBOLS 1 base material layer 2 adhesive agent layer 3 stainless steel foil 4 heat sealing | fusion resin layer 5 adhesive layer 6 protective layer 10 ... battery packaging material 10a ... surface 20 of convex part side of molding part of battery packaging material ... double-sided adhesive Tape 21 ... acrylic board 31 ... double-sided tape 41 ... aluminum foil

Claims (10)

It comprises a laminate having at least a protective layer, a base material layer, a stainless steel foil, and a heat fusible resin layer in this order,
Wherein when measured by attenuated total reflection Fourier transform infrared spectroscopy from the outermost surface side of the protective layer, the maximum value A of the absorbance wave number of infrared rays are detected from 2800 cm ^-1 in the range of 3000 cm ^-1, 2200 cm ^- A battery packaging material, wherein the maximum absorbance B detected in the range of ¹ to 2300 cm ^-1 satisfies the relationship of 0.05 ≦ B / A ≦ 0.75. The packaging material for batteries of Claim 1 in which the said protective layer contains the compound which has an isocyanate group. The protective layer comprises a urethane resin formed of at least one polyol selected from the group consisting of a polyester polyol having an hydroxyl group-containing group in a side chain and an acrylic polyol, and a compound having an isocyanate group. Or the packaging material for batteries as described in 2. The battery packaging material according to any one of claims 1 to 3, wherein ink is printed and used on at least a part of the surface of the protective layer. The battery packaging material according to any one of claims 1 to 4, further comprising an information carrier made of ink on at least a part of the surface of the protective layer. The thickness of the laminate is 45 μm or more and 120 μm or less,
The thickness of the stainless steel foil is 15 μm or more and 40 μm or less,
The battery packaging material according to any one of claims 1 to 5, wherein the bending stiffness of the laminate is 0.60 gf cm ² / cm or more and 6.0 gf cm ² / cm or less. The battery packaging material according to any one of claims 1 to 6, wherein an adhesive layer is provided between the base layer and the stainless steel foil. The battery packaging material according to any one of claims 1 to 7, further comprising an adhesive layer between the stainless steel foil and the heat sealable resin layer. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is contained in a package formed of the battery packaging material according to any one of claims 1 to 8. Laminating at least a protective layer, a base material layer, a stainless steel foil, and a heat fusible resin layer to obtain a laminate;
A curing step of curing the protective layer;
Equipped with
In the curing step, when measured by attenuated total reflection Fourier transform infrared spectroscopy from the outermost surface side of the protective layer, the maximum value of absorbance wave number of infrared rays are detected from 2800 cm ^-1 in the range of 3000 cm ^-1 and a, as the wave number of the infrared and the maximum value B of the absorbance detected from 2200 cm ^-1 in the range of 2300 cm ^-1, satisfy the relationship of 0.05 ≦ B / a ≦ 0.75, the protective layer Of curing the battery packaging material.

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