JP7095700B2 - Battery packaging materials, batteries, and methods for manufacturing battery packaging materials - Google Patents

Description

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

Conventionally, various types of batteries have been developed, but in all batteries, packaging materials are indispensable members for encapsulating battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been widely used for battery packaging, but in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes. At the same time, there is a demand for thinner and lighter weight. However, the metal packaging material for batteries, which has been widely used in the past, has a drawback that it is difficult to keep up with the diversification of shapes and there is a limit to weight reduction.

Therefore, as a battery packaging material that can be easily processed into various shapes and can be made thinner and lighter, it is in the form of a film in which a base material layer / adhesive layer / barrier layer / heat-sealing resin layer is sequentially laminated. (For example, see Patent Document 1). Such a film-shaped packaging material for a battery is formed so that the battery element can be sealed by heat-sealing the peripheral portions of the heat-sealing resin layers so as to face each other.

When a battery is manufactured using the battery packaging material as described above, the electrolytic solution may adhere to the base material layer located on the outermost surface of the battery packaging material. When the electrolytic solution adheres to the base material layer, the base material layer may be discolored. Therefore, a protective layer having electrolytic solution resistance or the like may be provided on the base material layer.

Further, conventionally, when printing a bar code or the like is formed on a battery packaging material, a method of attaching a sticker on which the printing is formed to the surface on the base material layer side is generally adopted.

However, when the printed seal is attached to the surface of the base material layer side, the thickness and weight of the battery packaging material increase. Therefore, in view of the recent tendency of the packaging material for batteries to become thinner and lighter, a method of printing by printing ink directly on the surface of the packaging material for batteries on the base material layer side has been studied.

As a method of printing directly on the surface of the battery packaging material on the base material layer side by printing ink, 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 on 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 the object to be printed to form a print on the object to be printed. In such pad printing, since the ink is transferred to the object to be printed using an elastic silicon pad or the like, it is easy to print on the surface of the battery packaging material after molding, and the battery element is used as the battery packaging material. It has the advantage that it can be printed on the battery after being sealed.

Japanese Unexamined Patent Publication No. 2008-287971

As described above, when the electrolytic solution adheres to the base material layer, the base material layer may be discolored. Therefore, a protective layer having electrolytic solution resistance or the like may be provided on the base material layer. As such a protective layer, a protective layer cured by using a curing agent such as a curing agent having an isocyanate group is known (for example, International Publication WO2013 / 069698). However, as a result of studies by the present inventors, when a protective layer cured with a curing agent having an isocyanate group is provided, the reaction of the isocyanate group is insufficient (a large amount of unreacted isocyanate remains). If this is the case, the electrolytic solution resistance is not exhibited, and on the other hand, if the reaction of the isocyanate group proceeds too much (no unreacted isocyanate remains), the electrolytic solution resistance is improved, but the surface of such a protective layer. When an attempt was made to print ink on the surface of the protective layer, it became clear that the ink was repelled on the surface of the protective layer, making it difficult for the ink to fix, and there may be a missing portion where the ink was not formed. In particular, it has become clear that the printability when printed by pad printing tends to be insufficient.

Further, for the purpose of imparting distinctiveness to the battery packaging material, a colored layer is further provided between the base material layer and the barrier layer, so that the colored layer is formed on the surface of the battery packaging material on the base material layer side. There is an advantage that the distinctiveness given to the packaging material for batteries and the variation of the design are expanded by the combination with the printing.

Under such circumstances, the present invention relates to a battery packaging material comprising a laminate having at least a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer in this order. The main purpose is to provide a packaging material for a battery having excellent surface electrolytic solution resistance and ink printing characteristics. Further, it is also an object of the present invention to provide a method for manufacturing the packaging material for a battery and a battery using the packaging material for the battery.

The present inventors have made diligent studies to solve the above problems. As a result, it is composed of a laminate having at least a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer in this order, and Fourier-converted infrared spectroscopy from the outermost surface side of the protective layer. The maximum absorbance A detected in the range of 2800 cm ^-1 to 3000 cm ^-1 and the absorbance detected in the range of 2200 cm ^-1 to 2300 cm ^-1 when measured by the attenuation total reflection of the analysis method. By satisfying the relationship of 0.05 ≤ B / A ≤ 0.75, the maximum value B of B is not only excellent in electrolytic solution resistance but also excellent in ink printing characteristics. I found that it would be. The present invention has been completed by further studies based on these findings.

That is, the present invention provides the inventions of the following aspects.
Item 1. It is composed of a laminate having at least a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer in this order.
When measured from the outermost surface side of the protective layer by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis, the maximum value A of the absorbance detected in the range of 2800 cm ^-1 to 3000 cm ^{-1 and} 2200 cm- A packaging material for a battery, wherein the maximum value B of the absorbance detected in the range of ¹ to 2300 cm ^-1 satisfies the relationship of 0.05 ≦ B / A ≦ 0.75.
Item 2. Item 2. The battery packaging material according to Item 1, wherein the colored layer is composed of an adhesive layer containing a colorant.
Item 3. Item 2. The battery packaging material according to Item 1, wherein an adhesive layer is provided between the colored layer and the barrier layer.
Item 4. Item 6. The battery packaging material according to any one of Items 1 to 3, wherein the protective layer contains a compound having an isocyanate group.
Item 5. Items 1 to 1, wherein the protective layer contains at least one polyol selected from the group consisting of polyester polyols and acrylic polyols having a group having a hydroxyl group in the side chain, and a urethane resin formed of a compound having an isocyanate group. The packaging material for a battery according to any one of 4.
Item 6. Item 2. The battery packaging material according to any one of Items 1 to 5, which is used by printing ink on at least a part of the surface of the protective layer.
Item 7. Item 2. The packaging material for a battery according to any one of Items 1 to 6, wherein an information carrying portion composed of ink is provided on at least a part of the surface of the protective layer.
Item 8. Item 2. The packaging material for a battery according to any one of Items 1 to 7, which has an adhesive layer between the barrier layer and the heat-sealing resin layer.
Item 9. Item 6. The battery packaging material according to any one of Items 1 to 8, wherein the barrier layer is aluminum foil.
Item 10. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of Items 1 to 9.
Item 11. At least, a laminating step of laminating a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer to obtain a laminated body.
The curing step of curing the protective layer and
Equipped with
In the curing step, the maximum value of the absorbance detected in the range of 2800 cm ^-1 to 3000 cm ^-1 when the infrared wave number is measured from the outermost surface side of the protective layer by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method. The protective layer so that A and the maximum value B of the absorbance detected in the range of 2200 cm ^-1 to 2300 cm ^-1 in the infrared wave number satisfy the relationship of 0.05 ≤ B / A ≤ 0.75. A method of manufacturing packaging materials for batteries that cures.

According to the present invention, in a battery packaging material composed of a laminate having at least a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer in this order, the surface of the packaging material is electrolytically resistant. It is possible to provide a packaging material for a battery having excellent liquid properties and printing characteristics of an ink. Further, according to the present invention, it is also possible to provide a battery using the battery packaging material and a method for manufacturing the battery packaging material.

It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a schematic diagram for demonstrating the evaluation method of tape adhesion. It is a schematic diagram for demonstrating the evaluation method of tape adhesion.

The packaging material for a battery of the present invention is composed of a laminate having at least a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer in this order, and is on the outermost surface side of the protective layer. Maximum absorbance A detected in the range of 2800 cm ^-1 to 3000 cm ^-1 and the range of 2200 cm ^-1 to 2300 cm ^-1 when measured by the attenuated total reflection of infrared spectroscopic analysis. It is characterized in that the maximum value B of the absorbance detected in the above satisfies the relationship of 0.05 ≦ B / A ≦ 0.75. Hereinafter, the battery packaging material of the present invention, the method for manufacturing the battery packaging material, and the battery using the battery packaging material will be described in detail.

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

1. 1. Laminated structure of battery packaging material As shown in FIG. 1, the battery packaging material of the present invention has at least a protective layer 6, a base material layer 1, a colored layer 7, a barrier layer 3, and a heat-sealing resin layer 4. It is composed of a laminated body having in this order. In the battery packaging material of the present invention, the protective layer 6 is the outermost layer, and the heat-sealing resin layer 4 is the innermost layer. That is, at the time of assembling the battery, the heat-sealing resin layers 4 located on the peripheral edge of the battery element are heat-sealed to seal the battery element, whereby the battery element is sealed.

As shown in FIGS. 1 to 4, the battery packaging material of the present invention is provided with an adhesive layer 2 between the base material layer 1 and the barrier layer 3 as needed for the purpose of enhancing their adhesiveness. It may have been. FIGS. 1 and 3 show a diagram in which a colorant is blended in the adhesive layer 2 and the adhesive layer 2 constitutes the colored layer 7. Further, FIGS. 2 and 4 show an embodiment in which the adhesive layer 2 is provided between the colored layer 7 and the barrier layer 3 separately from the colored layer 7. As will be described later, in the embodiments of FIGS. 2 and 4, for example, a colored layer formed on the surface of the base material layer 1 is prepared, and this is laminated with a barrier layer, a heat-sealing resin layer, or the like. It is possible to manufacture packaging materials for batteries. As shown in FIGS. 3 and 4, an adhesive layer 5 may be provided between the barrier layer 3 and the heat-bondable resin layer 4 for the purpose of enhancing their adhesiveness, if necessary.

The total thickness of the packaging material for a battery of the present invention is not particularly limited, but is preferably about 50 to 200 μm, and more preferably about 60 to 160 μm.

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

In the present invention, the wave number of infrared rays is 2800 cm ^-1 to 3000 cm-when measured from the outermost surface side of the protective layer by attenuation total reflection (ATR) of Fourier transformed infrared (FT ^- IR) spectroscopy. The maximum value A of the absorbance detected in the range of ¹ and the maximum value B of the absorbance detected in the range of 2200 cm ^-1 to 2300 cm ^-1 of the infrared wave number are 0.05 ≤ B / A ≤ 0.75. Satisfies the relationship. The maximum value of the absorbance in the present invention is the maximum value of the absorbance measured by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method, and is measured with 32 integration times and a wave number resolution of 4 cm ^-1 .

The maximum value of the absorbance detected in the range of 2800 cm ^-1 to 3000 cm ^-1 in the infrared wave number mainly represents the maximum value of the absorbance due to the CH expansion and contraction vibration. Further, the maximum value of the absorbance detected in the range of 2200 cm ^-1 to 2300 cm ^-1 of the infrared wave number mainly represents the maximum value of the absorbance due to N = C = O expansion and contraction vibration. The specific measurement conditions for the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method are as follows. The "range of 2800 cm ^-1 to 3000 cm ^-1 " includes 2800 cm ^-1 and 3000 cm ^-1 , and the "range of 2200 cm ^-1 to 2300 cm ^-1 " includes 2200 cm ^-1 and 2300 cm ^-1 . Is done.

(Measurement conditions for attenuation total reflection by Fourier transform infrared spectroscopy)
Prism: Germanium wavenumber resolution: 4cm ^-1
Number of integrations: 32 times Maximum value of absorbance A: Wave number 2750 to 3100 cm ^-1 is connected by a straight line to take a baseline, and the maximum intensity absorbance up to the maximum value of absorbance in the range of wave number 2800 to 3000 cm ^-1 with the baseline. Value B: Wave number 2000-2500 cm ^-1 is connected by a straight line to take a baseline, and the intensity of the absorbance up to the maximum value in the range of wave number 2200-2300 cm ^-1 with the baseline.

Absorption by CH stretch vibration, where the wave number of infrared rays is detected in the range of 2800 cm ^-1 to 3000 cm ^-1 , mainly formed by the protective layer 6, measured by the attenuation total reflection of the Fourier transform infrared spectroscopic analysis method. It is caused by the resin (main agent that reacts with the curing agent). Further, the absorption due to the N = C = O expansion / contraction vibration detected in the range of 2200 cm ^-1 to 2300 cm ^-1 in the infrared wave number is mainly due to the compound (curing agent) having an isocyanate group. 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). Further, the protective layer 6 is preferably formed of at least one polyol (main agent) selected from the group consisting of polyester polyols and acrylic polyols having a group having a hydroxyl group in the side chain, and a compound having an isocyanate group. Contains urethane resin. For example, in the battery packaging material of the present invention, by leaving a predetermined amount of unreacted isocyanate groups of the curing agent, not only the electrolytic solution resistance of the protective layer 6 is improved, but also the electrolytic solution resistance of the protective layer 6 is improved, and the surface of the protective layer 6 is covered. 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 and the printing characteristics of the ink of the packaging material for batteries of the present invention, the maximum value A of the absorbance and the maximum value B of the absorbance are 0.10 ≦ B / A ≦ 0. It is preferable to satisfy the relationship of 70. 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 are 0.10 ≦ B / A ≦ 0.60. It is particularly preferable to satisfy the relationship of.

In the packaging material for batteries of the present invention, the resin (main agent that reacts with the curing agent) forming the protective layer 6 is a functional group (for example, a hydroxyl group or an amino group) that reacts with a compound having an isocyanate group (curing agent) described later. Etc.), and examples thereof include polyol compounds such as polyester polyols and acrylic polyols.

Examples of the polyester polyol include a polyester polyol obtained by reacting one or more of dibasic acids with one or more of compounds having three or more hydroxyl groups. Of the hydroxyl groups of the compound having three or more hydroxyl groups, the unreacted moiety becomes the hydroxyl group of the side chain of the polyester polyol.

Examples of the dibasic acid include aliphatic dibasic acids such as succinic acid, glutaric acid, adipic acid, pimelli acid, suberic acid, azelaic acid, sebacic acid, and brassic acid; isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and the like. Examples include the aromatic dibasic acid of.

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

Further, as the polyester polyol, in addition to the compound having three or more dibasic acids and hydroxyl groups, a compound reacted with a diol may be used, if necessary. Examples of the diol include aliphatic diols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, and dodecanediol; cyclohexanediol, Alicyclic diols such as hydrogenated xylylene glycol; aromatic diols such as xylylene glycol and the like can be mentioned.

Examples of the acrylic polyol include a copolymer obtained by copolymerizing at least a hydroxyl group-containing acrylic monomer and (meth) acrylic acid and having a repeating unit derived from (meth) acrylic acid as a main component.

Examples of the hydroxyl group-containing acrylic monomer include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. As a component that copolymerizes with the hydroxyl group-containing acrylic monomer and (meth) acrylic acid, an alkyl (meth) acrylate-based monomer (as an alkyl group, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, or an-butyl). Groups, i-butyl groups, t-butyl groups, 2-ethylhexyl groups, cyclohexyl groups, etc.); (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide (alkyl). Examples of the group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, a 2-ethylhexyl group, a cyclohexyl group and the like), N. -Akyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide (examples of the alkoxy group include a methoxy group, an ethoxy group, a butoxy group, an isobutoxy group, etc.), N-methylol (meth) acrylamide, N. -Amid group-containing monomers such as phenyl (meth) acrylamide; glycidyl group-containing monomers such as glycidyl (meth) acrylate and allyl glycidyl ether; Silane-containing monomers; Examples thereof include isocyanate group-containing monomers such as (meth) acryloxypropyl isocyanate.

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

As the polyol compound, an acrylic polyol is preferable because it is superior in resistance to an electrolytic solution.

In the present invention, the resin contained in the protective layer 6 may be one in which all functional groups capable of reacting with the isocyanate group have reacted with a compound (curing agent) having an isocyanate group, or may not react with the curing agent. (For example, those in which at least a part of the hydroxyl group of the polyol compound remains) may be included.

The curing agent having an isocyanate group is not particularly limited, and a known isocyanate compound can be used. Specific examples of the isocyanate compound include aliphatic diisocyanates such as hexamethylene diisocyanate (HMDI) and trimethylhexamethylene diisocyanate (TMDI); alicyclic diisocyanates such as isophorone diisocyanate (IPDI); and xylylene diisocyanate (XDI). Aromatic aliphatic diisocyanates; aromatic diisocyanates such as toluene diisocyanate (TDI) and 4,4-diphenylmethane diisocyanate (MDI); diisocyanate dimerate (DDI), hydrogenated TDI (HTDI), hydrogenated XDI Hydrogenated diisocyanates such as (H6XDI) and hydrided MDI (H12MDI); diisocyanates and trimer of these diisocyanate compounds, and higher molecular weight polyisocyanates; polyhydric alcohol or water such as trimethylolpropane, or Examples thereof include an additive with a low molecular weight polyester resin. One type of curing agent may be used alone, or two or more types may be used in combination.

The method for forming the protective layer 6 is not particularly limited, but for example, a resin composition containing a main agent and a curing agent having an isocyanate group is applied onto one surface of the base material layer 1, and heating, light irradiation, or the like is performed. A method of curing a part of the curing agent can be mentioned. Examples of the components contained in the resin composition include the above-mentioned resin and the additives described below.

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 electrolytic solution resistance and the printing characteristics of the ink. ..

The protective layer 6 may contain additives. Examples of the additive include fine particles having a particle size 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. The shape of the additive is also not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a balloon shape. As additives, specifically, talc, silica, graphite, kaolin, montmoriloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodium 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 Examples thereof include melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. These additives may be used alone or in combination of two or more. Among these additives, silica and barium sulfate are preferable from the viewpoint of dispersion stability and cost, and the surface of the additive is subjected to various surface treatments such as insulation treatment and high dispersibility treatment. May be good.

The content of the additive in the protective layer 6 is not particularly limited, but is preferably about 5 to 30% by mass, and more preferably about 10 to 20% by mass.

Further, in the step of fixing the battery to a protective case made of plastic or the like, a step of fixing the battery packaging material and the protective case with an adhesive tape is carried out. By adding a filler as an additive to the protective layer 6 and making the surface of the protective layer 6 uneven, the adhesive area between the adhesive tape and the protective layer 6 can be increased, and the battery packaging material and the protective case can be more firmly fixed. There is an advantage that a matte feeling can be given to the packaging material for batteries. Specific examples of the filler include inorganic fillers such as titanium oxide, silica, talc, clay, heavy calcium carbonate, light calcium carbonate, barium sulfate, calcium silicate, synthetic silicate, aluminum hydroxide, and fine powder of silicate. Can be mentioned. Only one type of filler may be used, or two or more types may be mixed and used. Among the inorganic fillers, an inorganic filler made of silica or precipitated barium sulfate is preferable because it is easy to handle and obtain. The precipitated barium sulfate refers to barium sulfate produced by utilizing a chemical reaction, and is characterized by being able to control the particle size. The content of the filler in the protective layer 6 is preferably about 2.0 to 8.7% by mass, for example, when the filler is silica having an average particle diameter of about 1.0 to 3.0 μm. Further, for example, when the filler is a precipitate barium sulfate having an average particle diameter smaller than 1.5 μm, it is preferably about 13.0 to 40.0% by mass. The content of the filler is the content of the filler in the protective layer 6, and is the content after the solvent is volatilized from the above-mentioned resin composition for forming the protective layer 6 containing the filler. The average particle size of the filler is the median diameter measured by the laser diffraction / scattering type particle size distribution measuring device.

In the battery packaging material of the present invention, ink can be suitably printed on at least a part of the surface of the protective layer 6. That is, in the present invention, in the battery packaging material in which the ink is printed on the surface of the protective layer 6, the ink (cured product, dried product, etc.) printed on the surface of the protective layer 6 is exposed. The printed ink can form an information-carrying portion by printing, for example, a barcode, a pattern, a character, or the like. An information carrier made of ink may be provided on at least a part of the surface of the protective layer 6. The ink used for printing is not particularly limited, and known inks can be used. For example, photocurable inks that cure by irradiating with ultraviolet rays, inkjet inks used in inkjet printers, and the like can be used. Can be used. The ink usually contains a component having a functional group that reacts with an isocyanate group such as a hydroxyl group and 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 colored layer 7.

The material forming the base material layer 1 is not particularly limited as long as it has an insulating property. Examples of the material forming the base material layer 1 include polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and a mixture or copolymer thereof. Can be mentioned.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and ethylene terephthalate as the main constituents of the copolymerized polyester and butylene terephthalate as the main constituent of the repeating unit. Examples thereof include the copolymerized polyester. Further, as the copolymerized polyester having ethylene terephthalate as the main body of the repeating unit, specifically, a copolymer polyester having ethylene terephthalate as the main body of the repeating unit and polymerizing with ethylene isophthalate (hereinafter, polyethylene (terephthalate / isophthalate)). (Abbreviated after), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) , Polyethylene (terephthalate / decandicarboxylate) and the like. The copolymerized polyester having butylene terephthalate as the main body of the repeating unit is specifically a copolymer polyester having butylene terephthalate as the main body of the repeating unit and polymerizing with butylene isophthalate (hereinafter, polybutylene (terephthalate / isophthalate)). (Abbreviated after), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decandicarboxylate), polybutylene naphthalate and the like. These polyesters may be used alone or in combination of two or more. Polyester has an advantage that it has excellent electrolytic solution resistance and is less likely to cause whitening due to adhesion of the electrolytic solution, and is suitably used as a material for forming the base material layer 1.

Specific examples of the polyamide include an aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid. Nylon 6I, Nylon 6T, Nylon 6IT, Nylon 6I6T (I stands for isophthalic acid, T stands for terephthalic acid) and other hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamides, polymethoxylylenazi Aroma-containing polyamides such as pamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); further copolymerized with a lactam component and an isocyanate component such as 4,4'-diphenylmethane-diisocyanate. Examples thereof include polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of the polyamides and copolymerized polyamides with polyesters and polyalkylene ether glycols; and copolymers thereof. These polyamides may be used alone or in combination of two or more. The stretched polyamide film has excellent stretchability, can prevent whitening due to resin cracking of the base material layer 1 during molding, and is suitably used as a material for forming 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, particularly a biaxially stretched resin film, has improved heat resistance due to orientation crystallization, and is therefore preferably used as the base material layer 1. Further, the base material layer 1 may be formed by coating the above material on the barrier layer 3.

Among these, examples of the resin film forming the base material layer 1 include nylon and polyester, more preferably biaxially stretched nylon, biaxially stretched polyester, and particularly preferably biaxially stretched nylon.

The thickness of the base material layer 1 is, for example, about 5 to 50 μm, preferably about 15 to 30 μm.

[Colored layer 7]
The colored layer 7 is a layer provided between the base material layer 1 and the barrier layer 3 for the purpose of imparting distinctiveness to the battery packaging material. By providing the coloring layer 7, the packaging material for a battery can be colored.

The colored layer 7 can be formed, for example, by applying an ink containing a colorant to the surface of the base material layer 1. When the battery packaging material of the present invention has the adhesive layer 2 between the base material layer 1 and the barrier layer 3, the adhesive layer 2 is formed by blending the adhesive layer 2 with a colorant. Can also be used as the colored layer 7. By using the adhesive layer 2 as the colored layer 7, the adhesive layer 2 can exhibit both a function of adhering the base material layer 1 and the barrier layer 3 and a function of coloring the battery packaging material. can.

As the colorant contained in the color layer 7, known substances such as pigments and dyes can be used. Further, as the colorant, only one kind may be used, or two or more kinds may be mixed and used.

Specific examples of the inorganic pigment include carbon black and titanium oxide. Specific examples of the organic pigment include azo pigments, phthalocyanine pigments, condensed polycyclic pigments and the like. Examples of the azo pigment include soluble pigments such as watching red and carmine 6C; insoluble azo pigments such as monoazo yellow, disazo yellow, pyrazolone orange, pyrazolone red and permanent red, and examples of the phthalocyanine pigment include copper phthalocyanine pigment and none. Examples of the metal phthalocyanine pigment include blue pigments and green pigments, and examples of the condensed polycyclic pigment include dioxazine violet and quinacridone violet. Further, as the pigment, a pearl pigment, a fluorescent pigment, or the like can also be used.

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

When the colored layer 7 is provided separately from the adhesive layer 2, the colored layer 7 can be formed, for example, by applying ink to the surface of the base material layer 1. The ink forming the colored layer 7 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. As the solvent contained in the ink, a known solvent can be used, and examples thereof include toluene and the like.

The diamine is not particularly limited, and examples thereof include ethylenediamine, dimerdiamine, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, dicyclohexylmethanediamine, and 2-hydroxyethylpropylenediamine. Among them, as the diamine, it is preferable to use one or more diamines selected from the group consisting of ethylenediamine, dimerdiamine, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine and dicyclohexylmethanediamine.

Diamine has a faster reaction rate with a curing agent (isocyanate, etc.) than polyol, and can be cured in a short time. That is, the diamine reacts with the curing agent together with the polyol to promote the cross-linking curing of the ink.

The polyol is not particularly limited, but it is preferable to use one or more of the polyols selected from the group consisting of polyurethane-based polyols, polyester-based polyols and polyether-based polyols.

The number average molecular weight of the polyol is preferably in the range of about 1000 to 8000. When it is 1000 or more, the adhesive strength after curing can be increased, and when it is 8000 or less, the reaction rate with the curing agent can be increased.

The curing agent is not particularly limited, and examples thereof include isocyanate compounds. As the isocyanate compound, for example, various aromatic, aliphatic, and alicyclic isocyanate compounds can be used. Specific examples thereof include toluene diisocyanate (TDI), diphenylmethane diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate and the like.

When the coloring layer 7 is provided separately from the adhesive layer 2, the content of the coloring agent in the coloring layer 7 is not particularly limited as long as the packaging material for batteries can be colored, and examples thereof include about 5 to 60% by mass. .. For example, when the colorant is carbon black, the content of carbon black is preferably about 20 to 50% by mass. The total content of the diamine, the polyol, and the curing agent is preferably about 40 to 85% by mass. The curing agent is preferably about 2 to 20 parts by mass with respect to 100 parts by mass of the total amount of the colorant, diamine and polyol.

When the colored layer 7 is provided separately from the adhesive layer 2, the thickness of the colored layer 7 (after drying) is preferably about 1 to 4 μm. When the thickness is 1 μm or more, the color tone of the colored layer 7 does not remain transparent, and the color and gloss of the barrier layer 3 can be sufficiently concealed. Further, when the thickness is 4 μm or less, it is possible to sufficiently prevent the colored layer 7 from being partially cracked during molding.

When the colored layer 7 is provided separately from the adhesive layer 2, the colored layer 7 can be formed, for example, by applying an ink for forming the colored layer 7 to the surface of the base material layer 1. Examples of the ink application method include a printing method such as a gravure printing method, a reverse roll coating method, and a lip roll coating method.

[Adhesive layer 2]
In the packaging material for batteries of the present invention, the adhesive layer 2 is a layer provided as necessary for adhering the base material layer 1 and the barrier layer 3. Further, as described above, the adhesive layer 2 can be made into the colored layer 7 by blending the colorant with the adhesive layer 2. In the present invention, both the colored layer 7 provided separately from the adhesive layer 2 and the adhesive layer 2 (that is, the colored layer 7) containing the colorant may be provided.

The adhesive layer 2 is formed by an adhesive capable of adhering the base material layer 1 or the colored layer 7 and the barrier layer 3. The adhesive used to form the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism used for forming the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatile type, a heat melting type, a thermal 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, and copolymerized polyester. Resins; polyether adhesives; polyurethane adhesives; epoxy resins; phenolic resins; polyamide resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefins, acid-modified polyolefins, metal-modified polyolefins, etc. Polyolefin resin; Polyvinyl acetate resin; Cellulosic adhesive; (Meta) acrylic resin; Polyimide resin; Amino resin such as urea resin and melamine resin; Rubber such as chloroprene rubber, nitrile rubber, styrene-butadiene rubber ; Silicone-based resin; Fluoroethylene propylene copolymer and the like can be mentioned. These adhesive components may be used alone or in combination of two or more. The combination mode of the two or more kinds of adhesive components is not particularly limited, and examples thereof include a mixed resin of polyamide and acid-modified polyolefin, a mixed resin of polyamide and metal-modified polyolefin, and polyamide and polyester. Examples thereof include a mixed resin of polyester and acid-modified polyolefin, and a mixed resin of polyester and metal-modified polyolefin. Among these, it is excellent in spreadability, durability under high humidity conditions, yellowing suppressing action, heat deterioration suppressing action at the time of heat sealing, etc., and suppresses a decrease in laminate strength between the base material layer 1 and the barrier layer 3. From the viewpoint of effectively suppressing the occurrence of delamination, a polyurethane-based two-component curable adhesive; polyamide, polyester, or a blended resin of these and a modified polyolefin can be mentioned.

Further, the adhesive layer 2 may be multi-layered with different adhesive components. When the adhesive layer 2 is multi-layered with different adhesive components, the adhesive component arranged on the base layer 1 side is used as the base layer from the viewpoint of improving the lamination strength between the base layer 1 and the barrier layer 3. It is preferable to select a resin having excellent adhesiveness to 1 and to select an adhesive component having excellent adhesiveness to the barrier layer 3 as the adhesive component arranged on the barrier layer 3 side. When the adhesive layer 2 is multi-layered with different adhesive components, specifically, the adhesive component arranged on the barrier layer 3 side is preferably an acid-modified polyolefin, a metal-modified polyolefin, a polyester and an acid-modified polyolefin. Examples thereof include a resin mixed with and a resin containing a copolymerized polyester.

The adhesive layer 2 contains a colorant in the case of the colored layer 7. Since the adhesive layer 2 contains a colorant, the battery packaging material can be colored. As the colorant, known ones such as pigments and dyes can be used. Further, as the colorant, only one kind may be used, or two or more kinds may be mixed and used. Examples of the colorant include the same as those exemplified in the column of [Colored layer 7].

In the adhesive layer 2, the average particle size of the pigment is not particularly limited, and examples thereof include about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle size of the pigment is the median diameter measured by the laser diffraction / scattering type particle size distribution measuring device.

The content of the colorant in the adhesive layer 2 is not particularly limited as long as the battery packaging material is colored, and examples thereof include about 5 to 60% by mass.

The thickness of the adhesive layer 2 is, for example, about 2 to 50 μm, preferably about 3 to 25 μm.

[Barrier layer 3]
In the battery packaging material, the barrier layer 3 is a layer having a function of improving the strength of the battery packaging material and preventing water vapor, oxygen, light and the like from entering the inside of the battery. The barrier layer 3 can be formed of a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film provided with these vapor deposition films, or the like, and is formed of a metal foil. Is preferable. Specific examples of the metal constituting the barrier layer 3 include aluminum, stainless steel, titanium, and the like, preferably aluminum. From the viewpoint of preventing wrinkles and pinholes from being generated in the barrier layer 3 during the manufacture of the packaging material for batteries, the barrier layer may be, for example, annealed aluminum (JIS H4160: 1994 A8021HO, JIS H4160: It is more preferably formed from a soft aluminum alloy foil such as 1994 A8079H-O, JIS H4000: 2014 A8021P-O, JIS H4000: 2014 A8079P-O).

The thickness of the barrier layer 3 is, for example, about 10 to 200 μm, preferably about 20 to 100 μm.

Further, in the barrier layer 3, at least one surface, preferably at least one surface on the heat-sealing resin layer 4 side, and more preferably both sides are subjected to chemical conversion treatment in order to stabilize adhesion, prevent dissolution and corrosion, and the like. It is preferable to have. Here, the chemical conversion treatment is a treatment for forming an acid-resistant film on the surface of the barrier layer 3. The chemical conversion treatment is a chromate treatment using a chromium compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium bicarbonate, acetylacetate chromate, chromium chloride, potassium sulfate chromium; phosphoric acid. Phosphoric acid treatment with a phosphoric acid compound such as sodium, potassium phosphate, ammonium phosphate, polyphosphate; an aminoated phenol polymer composed of repeating units represented by the following general formulas (1) to (4) was used. Chromate treatment and the like can be mentioned. In the aminoated phenol polymer, the repeating unit represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. May be 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. Further, R ¹ and R ² indicate the same or different hydroxy group, alkyl group, or 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 a linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group. Examples of the hydroxyalkyl groups represented by X, R ¹ and R ² include hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group and 3-. A linear or branched chain having 1 to 4 carbon atoms in which one hydroxy group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, or a 4-hydroxybutyl group is substituted. Alkyl groups can be mentioned. In the general formulas (1) to (4), X is preferably any one of a hydrogen atom, a hydroxy group, and a hydroxyalkyl group. The number average molecular weight of the amino acid phenol polymer composed of the repeating units represented by the general formulas (1) to (4) is, for example, about 5 to 1,000,000, preferably about 1000 to 20,000.

Further, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, a material in which metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide and fine particles of barium sulfate are dispersed in phosphoric acid is coated. A method of forming a corrosion resistant layer on the surface of the barrier layer 3 by performing a baking treatment at about 150 ° C. or higher can be mentioned. Further, a resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be formed on the corrosion resistant layer. Here, examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine-grafted acrylic resin obtained by grafting a primary amine on an acrylic main skeleton, polyallylamine, or a polyallylamine. The derivative, aminophenol and the like can be mentioned. These cationic polymers may be used alone or in combination of two or more. Examples of the cross-linking agent include a compound having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. These cross-linking agents may be used alone or in combination of two or more.

In these chemical conversion treatments, one kind of chemical conversion treatment may be carried out alone, or two or more kinds of chemical conversion treatments may be carried out in combination. Further, these chemical conversion treatments may be carried out by using one kind of compound alone or by using two or more kinds of compounds in combination. Among these, chromic acid treatment is preferable, and chemical conversion treatment in which a chromium compound, a phosphoric acid compound, and an amination phenol polymer are combined is more preferable. Among the chromium compounds, a chromic acid compound is preferable.

The amount of the acid-resistant film formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited, but for example, in the case of performing the chromate treatment by combining a chromic acid compound, a phosphoric acid compound, and an amination phenol polymer. The chromic acid compound is about 0.5 to 50 mg in terms of chromium, preferably about 1.0 to 40 mg, and the phosphorus compound is about 0.5 to 50 mg in terms of phosphorus, preferably about 1. per 1 m ² of the surface of the barrier layer 3. It is desirable that about 0 to 40 mg and about 1 to 200 mg, preferably about 5.0 to 150 mg of the amination phenol polymer are contained.

In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the barrier layer 3 by a bar coating method, a roll coating method, a gravure coating method, a dipping method, or the like, and then the temperature of the barrier layer 3 is applied. It is carried out by heating so that the temperature becomes about 70 to 200 ° C. Further, before the chemical conversion treatment is applied to the barrier layer 3, the barrier layer 3 may be subjected to a degreasing treatment by an alkaline dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method or the like in advance. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer 3.

[Heat-fused resin layer 4]
In the battery packaging material of the present invention, the heat-sealing resin layer 4 corresponds to the innermost layer, and is a layer in which the heat-sealing resin layers are heat-sealed to seal the battery element when the battery is assembled.

The resin component used in the heat-bondable resin layer 4 is not particularly limited as long as it can be heat-fused, and examples thereof include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins. Be done.

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

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

The carboxylic acid-modified polyolefin is a polymer modified by block-polymerizing or graft-polymerizing 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 a part of the monomers constituting the cyclic polyolefin in place of α, β-unsaturated carboxylic acid or an anhydride thereof, or α, β with respect to the cyclic polyolefin. -A polymer obtained by block polymerization or graft polymerization of an unsaturated carboxylic acid or an anhydride thereof. The same applies to the cyclic polyolefin that is modified with carboxylic acid. The carboxylic acid used for the modification is the same as that used for the modification of the carboxylic acid-modified polyolefin.

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

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

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

Examples of the fatty acid amide include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, 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 unsaturated fatty acid amides include oleic acid amides and erucic acid amides. Specific examples of the substituted amide include N-oleyl palmitate amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucate amide and the like. Further, specific examples of trimethylolamide include trimethylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, and hexamethylene bisstea. Examples thereof include acid amides, hexamethylene bisbechenic acid amides, hexamethylene hydroxystearic acid amides, N, N'-distealyl adipic acid amides, N, N'-distearyl sebasic acid amides and the like. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amides, ethylene biserukaic acid amides, hexamethylene bisoleic acid amides, N, N'-diorail adipic acid amides, and N, N'-diorail sebacic acid amides. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N, N'-distearylisophthalic acid amide.

When the heat-sealing 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-sealing resin layer 4 is the lubricant existing inside the heat-sealing resin layer 4 and the lubricant existing on the surface of the heat-sealing resin layer 4. The total amount.

The thickness of the heat-sealing resin layer 4 can be appropriately selected, but may be about 10 to 100 μm, preferably about 15 to 50 μm.

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

The adhesive layer 5 is formed by an adhesive capable of adhering the barrier layer 3 and the heat-sealing resin layer 4. Regarding the adhesive used for forming the adhesive layer 5, the adhesive mechanism, the type of the adhesive component, and the like are the same as in the case of the adhesive layer 2. Examples of the adhesive component used in the adhesive layer 5 include a polyolefin-based resin, more preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene.

The thickness of the adhesive layer 5 is, for example, about 2 to 50 μm, preferably about 15 to 30 μm.

3. 3. Method for Manufacturing Battery Packaging Material The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate in which each layer having a predetermined composition is laminated can be obtained. That is, the battery packaging material of the present invention is at least protected by a laminating step of laminating a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer to obtain a laminate. It is equipped with a curing step that cures the layer, and in the curing process, the wave number of infrared rays is 2800 cm ^-1 to 3000 cm ^-1 when measured from the outermost surface side of the protective layer by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method. The maximum value A of the absorbance detected in the range of 2200 cm ^-1 to the maximum value B of the absorbance detected in the range of 2200 cm ^-1 to 2300 cm -1 is 0.05 ≤ B / A ≤ 0.75. A method of curing the protective layer so as to satisfy the relationship is exemplified. Specifically, for example, it can be manufactured as follows.

First, at least, a laminated body in which the base material layer 1, the colored layer 7, and the barrier layer 3 are laminated in this order (hereinafter, may be referred to as “laminated body A”) is formed. The laminate A is formed, for example, by applying an adhesive used for forming the adhesive layer 2 to a barrier layer 3 having a chemical conversion treatment on the base material layer 1 or, if necessary, by a gravure coating method or a roll coating. It can be carried out by a dry laminating method in which the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being applied and dried by a coating method such as a method. When a colorant is blended with the adhesive forming the adhesive layer 2, the adhesive layer 2 can be the colored layer 7. When the colored layer 7 is provided separately from the adhesive layer 2, an ink for forming the colored layer 7 is previously applied to the surface of one side of the base layer 1 so that the colored layer 1 of the base layer 1 is provided. By laminating the 7 side and the barrier layer 3 via the adhesive layer 2, a laminated body A in which the base material layer 1, the colored layer 7, the adhesive layer 2, and the barrier layer 3 are laminated in this order can be obtained.

Next, the heat-sealing resin layer 4 is laminated on the barrier layer 3 of the laminated body A. When the heat-sealing resin layer 4 is directly laminated on the barrier layer 3, the resin components constituting the heat-sealing resin layer 4 are coated on the barrier layer 3 of the laminated body A by a gravure coating method or a roll coating method. It may be applied by a method such as. When the adhesive layer 5 is provided between the barrier layer 3 and the heat-sealing resin layer 4, for example, (1) the adhesive layer 5 and the heat-sealing resin layer are placed on the barrier layer 3 of the laminated body A. A method of laminating 4 by co-extruding (co-extrusion laminating method), (2) Separately, a laminated body in which the adhesive layer 5 and the heat-sealing resin layer 4 are laminated is formed, and this is used as a barrier layer of the laminated body A. A method of laminating on 3 by a thermal laminating method, (3) a method of extruding an adhesive for forming an adhesive layer 5 on the barrier layer 3 of the laminated body A, coating with a solution, drying at a high temperature, and baking. A method of laminating a heat-sealing resin layer 4 which has been previously formed into a sheet shape on the adhesive layer 5 by a thermal laminating method, and (4) a barrier layer 3 of a laminated body A, which is made into a sheet shape in advance. A method of laminating the laminate A and the heat-sealing resin layer 4 via the adhesive layer 5 while pouring the melted adhesive layer 5 between the filmed heat-sealing resin layer 4 (sandwich laminating method). And so on. Next, the resin composition forming the protective layer 6 is applied to the surface of the base material layer 1 and a part of the isocyanate groups of the curing agent is reacted to cure the protective layer. Examples of the method for reacting a part of the isocyanate group of the curing agent include heating and light irradiation. For example, in the case of heating, the infrared rays measured by the attenuation total reflection of the Fourier transform infrared spectroscopic analysis method by performing an aging step in an environment of about 24 to 120 hours at a temperature of about 30 to 90 ° C. The maximum value A of the absorbance detected in the range of 2800 cm ^-1 to 3000 cm ^-1 and the maximum value B of the absorbance detected in the range of 2200 cm ^-1 to 2300 cm ^-1 are 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 material layer 1 may be performed before laminating the base material layer 1 and the barrier layer 3. For example, after forming the protective layer 6 on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the protective layer 6. Further, the protective layer 6 may be formed on the surface of the base material layer 1 after laminating the base material layer 1 and the barrier layer 3 and before laminating the heat-sealing resin layer 4.

In the packaging material for batteries of the present invention, each layer constituting the laminated body improves or stabilizes film forming property, laminating process, suitability for secondary processing (pouching, embossing) of the final product, and the like, if necessary. Therefore, surface activation treatments such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

Further, in the battery packaging material of the present invention, both before and after molding the battery packaging material (molding for forming a space for enclosing the battery element) and before and after accommodating the battery element after molding. Ink may be printed on the surface of the protective layer 6. The printing method is not particularly limited, but pad printing is preferable when printing is performed on the packaging material for a battery after molding. The battery packaging material obtained by the manufacturing method of the present invention has an infrared wave number of 2800 cm ^-1 to 3000 cm ^-1 when measured from the outermost surface side of the protective layer 6 by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method. The maximum absorbance A detected in the range and the maximum absorbance B detected in the range 2200 cm ^-1 to 2300 cm ^-1 satisfy the specific relationship of 0.05 ≤ B / A ≤ 0.75. Therefore, the ink can be suitably printed even by pad printing in which the ink is easily repelled. Therefore, for example, printing of barcodes, patterns, characters, etc. can be suitably formed on at least a part of the surface of the protective layer 6. The ink used for printing is as described above.

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

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is connected to each of the positive electrode and the negative electrode by using a package formed of the battery packaging material of the present invention on the outside. The battery element is coated so that a flange portion (a region where the heat-sealing resin layers come into contact with each other) can be formed on the peripheral edge of the battery element, and the heat-sealing resin layers of the flange portion are heat-sealed. By sealing the battery, a battery using a battery packaging material is provided. When the battery element is housed using the battery packaging material of the present invention, the heat-sealing resin portion of the battery packaging material of the present invention is used so as to be inside (the surface in contact with the battery element).

Since the battery packaging material of the present invention is used in the battery of the present invention, for example, it is also suitable for the surface of the battery after the battery packaging material is molded and the battery element is sealed. Ink can be printed on the surface of the battery, and an information carrying portion can be suitably formed on at least a part of the surface of the battery by printing, for example, a bar code, a pattern, a character, or the like. Further, since the colored layer 7 is provided between the base material layer 1 and the barrier layer 3, it is applied to the battery packaging material by combining with the printing formed on the surface of the battery packaging material on the base material layer side. It is also possible to expand the variety of distinctiveness and design.

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 the secondary battery to which the packaging material for a battery of the present invention is applied is not particularly limited, and for example, a lithium ion battery, a lithium ion polymer battery, a lead storage battery, a nickel / hydrogen storage battery, a nickel / cadmium storage battery, a nickel / Examples include iron storage batteries, nickel / zinc storage batteries, silver oxide / zinc storage batteries, metal air batteries, polyvalent cation batteries, capacitors, and capacitors. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be mentioned as suitable application targets of the battery packaging material of the present invention.

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

<Manufacturing of packaging materials for batteries>
Example 1 and Comparative Example 1
A barrier layer 3 made of aluminum foil (thickness 40 μm) having chemical conversion treatment on both sides was laminated on a base material layer 1 made of a stretched nylon film (thickness 25 μm) by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) containing carbon black (median diameter 0.191 μm) is applied to one surface of the aluminum foil, and the barrier layer 3 is colored. Layer 7 (adhesive layer 2) (thickness 4 μm) was formed. Next, the colored layer 7 (adhesive layer 2) on the barrier layer 3 and the base material layer 1 are pressure-heated and bonded, and then an aging treatment is performed to obtain the base material layer 1 / colored layer 7 (adhesive layer 7). 2) / A laminated body of the barrier layer 3 was prepared. In the chemical conversion treatment of the aluminum foil used as the barrier layer 3, a treatment liquid composed of a phenol resin, a chromium fluoride compound, and phosphoric acid was rolled so that the coating amount of chromium was 10 mg / m ² (dry weight). It was applied to both sides of the aluminum foil by the coating method and baked under the condition that the film temperature was 180 ° C. or higher. The average particle size of carbon black is a median diameter measured by a laser diffraction / scattering type particle size distribution measuring device (“LA-950” manufactured by HORIBA, Ltd.).

Next, the acid-modified polypropylene resin (thickness 23 μm) and the polypropylene resin (thickness 23 μm) forming the heat-sealing resin layer 4 on the barrier layer 3 side of the laminate are co-extruded in a molten state (250 ° C.). As a result, the heat-sealing resin layer 4 (thickness 46 μm) was laminated on the barrier layer 3. Next, a resin composition for forming the protective layer 6 on the base material layer 1 (20% by mass of a polyester polyol having a hydroxyl value of 7 mgKOH / g and a weight average molecular weight of 15,000) and an aromatic as a curing agent having an isocyanate group. A resin composition containing 15% by mass of toluene diisocyanate (TDI), which is a diisocyanate curing agent, and 65% by mass of a solvent of methyl ethyl ketone) was applied by a gravure coating method to form a protective layer 6 on the surface of the base material layer 1 (thickness). 3 μm). Thus, a packaging material for a battery made of a laminated film in which a protective layer 6 / a base material layer 1 / a colored layer 7 (adhesive layer 2) / a barrier layer 3 / a heat-sealing resin layer 4 are laminated in this order was obtained. .. In the battery packaging materials of Example 1 and Comparative Example 1, after laminating each layer, aging was performed under the conditions shown in Table 1, respectively.

Examples 2 and 3 and Comparative Example 2
An ink containing a black pigment was printed on the base material layer 1 made of a stretched nylon film (thickness 25 μm) so as to have a thickness of 1 μm to form a black colored layer. Next, a barrier layer 3 made of aluminum foil (thickness 40 μm) having been subjected to chemical conversion treatment on both sides was laminated on the colored layer side of the base material layer by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum foil to form an adhesive layer 2 (thickness 4 μm) on the barrier layer 3. Next, the adhesive layer 2 on the barrier layer 3 and the base material layer 1 are pressure-heated and bonded together, and then an aging treatment is performed to perform a base material layer 1 / colored layer 7 / adhesive layer 2 / barrier layer 3. Laminates were prepared. In the chemical conversion treatment of the aluminum foil used as the barrier layer 3, a treatment liquid composed of a phenol resin, a chromium fluoride compound, and phosphoric acid was rolled so that the coating amount of chromium was 10 mg / m ² (dry weight). It was applied to both sides of the aluminum foil by the coating method and baked under the condition that the film temperature was 180 ° C. or higher.

Next, the acid-modified polypropylene resin (thickness 23 μm) and the polypropylene resin (thickness 23 μm) forming the heat-sealing resin layer 4 on the barrier layer 3 side of the laminate are co-extruded in a molten state (250 ° C.). As a result, the heat-sealing resin layer 4 (thickness 46 μm) was laminated on the barrier layer 3. Next, a resin composition for forming the protective layer 6 on the base material layer 1 (20% by mass of a polyester polyol having a hydroxyl value of 7 mgKOH / g and a weight average molecular weight of 15,000) and an aromatic as a curing agent having an isocyanate group. A resin composition containing 15% by mass of toluene diisocyanate (TDI), which is a diisocyanate curing agent, and 65% by mass of a solvent of methyl ethyl ketone) was applied by a gravure coating method to form a protective layer 6 on the surface of the base material layer 1 (thickness). 3 μm). Thus, a packaging material for a battery was obtained, which was a laminated film in which a protective layer 6 / a base material layer 1 / a colored layer 7 / an adhesive layer 2 / a barrier layer 3 / a heat-sealing resin layer 4 were laminated in this order. In the battery packaging materials of Examples 2 and 3 and Comparative Example 2, after laminating each layer, aging was performed under the conditions shown in Table 1, respectively.

Example 4 and Comparative Example 3
In Example 4, the same as in Example 1 except that a filler (silica particles having an average particle diameter of 1.0 μm) was added so that the ratio in the resin composition forming the protective layer 6 was 10% by mass. To prepare a packaging material for batteries. Further, in Comparative Example 3, Comparative Example 1 except that a filler (silica particles having an average particle diameter of 1.0 μm) was added so that the ratio in the resin composition forming the protective layer 6 was 10% by mass. In the same manner as above, a packaging material for batteries was produced. In the battery packaging materials of Example 4 and Comparative Example 3, after laminating each layer, aging was performed under the conditions shown in Table 1, respectively.

Examples 5 and 6 and Comparative Example 4
In Examples 5 and 6 and Comparative Example 4, a filler (silica particles having an average particle diameter of 1.0 μm) was added so that the ratio in the resin composition forming the protective layer 6 was 10% by mass. , Each of the same as in Examples 2 and 3, a packaging material for a battery was produced. Further, in Comparative Example 4, Comparative Example 2 except that a filler (silica particles having an average particle diameter of 1.0 μm) was added so that the ratio in the resin composition forming the protective layer 6 was 10% by mass. In the same manner as above, a packaging material for batteries was produced. In the battery packaging materials of Examples 5 and 6, each layer was laminated and then aged under the conditions shown in Table 1.

[Measurement of B / A of protective layer]
Attenuated total reflection by Fourier transform infrared spectroscopy was measured from the outermost surface side of the protective layer of the battery packaging material obtained above using Nicolet 380 manufactured by Thermo Scientific. From the obtained measurement results, the maximum value A of the absorbance detected in the range of 2800 cm ^-1 to 3000 cm ^-1 for the infrared wave number and the maximum value of the absorbance detected in the range of 2200 cm ^-1 to 2300 cm ^-1 for the infrared wave number. The value of B / A was calculated based on the value B. The results are shown in Table 1. The maximum value of the absorbance in the present invention is the maximum value of the absorbance measured by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method, and is measured with 32 integration times and a wave number resolution of 4 cm ^-1 . The specific measurement conditions for the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method are as follows.

(Measurement conditions for attenuation total reflection by Fourier transform infrared spectroscopy)
Prism: Germanium wavenumber resolution: 4cm ^-1
Number of integrations: 32 times Maximum value of absorbance A: Wave number 2750 to 3100 cm ^-1 is connected by a straight line to take a baseline, and the maximum intensity absorbance up to the maximum value of absorbance in the range of wave number 2800 to 3000 cm ^-1 with the baseline. Value B: Wave number 2000-2500 cm ^-1 is connected by a straight line to take a baseline, and the intensity of the absorbance up to the maximum value in the range of wave number 2200-2300 cm ^-1 with the baseline.

[Evaluation of electrolyte resistance]
From the battery packaging material obtained above, a test piece having a width of 100 mm and a length of 100 mm was cut out. Next, an electrolytic solution (composed of a mixed solution of 1 M LiPF ₆ and ethylene carbonate, diethyl carbonate and dimethyl carbonate (volume ratio 1: 1: 1)) was dropped on the surface of the protective layer at 24 ° C. and relative humidity. After leaving it in a 50% environment for 6 hours, the electrolytic solution was wiped off with ethanol, and changes in the surface were observed. At this time, the one with no change was designated as A, and the one with discoloration was designated as C. The results are shown in Table 1.

[Evaluation of ink printing characteristics]
Pad printing was applied to the surface of the protective layer of the battery packaging material obtained above, and the printing characteristics of the ink were evaluated. As the pad printing machine, SPACE PAD 6GX manufactured by Mishima Co., Ltd. was used. As the ink, UV ink PJU-A white manufactured by Navitas Co., Ltd. was used. The ink printed on the surface of the protective layer was cured by irradiating UV from a distance of 10 cm at an ultraviolet wavelength of 254 nm for 30 seconds with a handy UV lamp SUV-4 manufactured by AS ONE. The area of the printed surface was 100 mm ² . The printed surface after curing was observed with an optical microscope, and the printing characteristics of the ink were evaluated according to the following criteria. The following evaluations A and B can be said to have good ink printing characteristics. The ink was printed in an environment with a temperature of 24 ° C. and a relative humidity of 50%. The results are shown in Table 1.
A: Printing omissions are less than 5% of the entire printed pattern B: Printing omissions are 5% or more and 10% or less of the entire printed pattern C: Printing omissions are more than 10% of the entire printed pattern

[Evaluation of wear resistance]
In accordance with the method specified in JIS P 8136, the protective layer of the battery packaging material obtained above was subjected to a wear resistance test under the condition of 30 strokes, and the presence or absence of scratches was visually confirmed. .. If the protective layer after the test was not scratched, it was evaluated as A, and if it was scratched, it was evaluated as C. The results are shown in Table 1.

[Evaluation of tape adhesion]
As shown in FIGS. 5 and 6, each battery packaging material obtained above is cut out in a size of 15 mm in width and 175 mm in length, and a double-sided adhesive tape 20 (Tesa SE) having a width of 5 mm and a length of 125 mm is formed on the surface of the protective layer. The company's tesa (registered trademark) 70415) was attached. The surface of the protective layer 10 of the battery packaging material cut out with a width of 15 mm and a length of 300 mm is overlapped on the surface thereof, and the crimping device described in JIS-Z0237: 2009 Adhesive Tape / Adhesive Sheet Test Method 10.2.4 is applied. The packaging material for batteries and the adhesive tape were crimped using. In an environment with a temperature of 24 ° C. and a relative humidity of 50%, the mass of the rollers of the crimping device reciprocates twice at a speed of 2 kg and 10 mm / sec. After crimping with a roller and storing at a temperature of 24 ° C. and a relative humidity of 50% RH for 1 hour, the packaging material for batteries cut out with a width of 15 mm and a length of 300 mm is folded back to 180 ° at the end of the double-sided adhesive tape, and is used for the above-mentioned battery. The packaging material was fixed above and below the tensile tester, and a tensile test was performed in an environment with a peeling angle of 180 °, a temperature of 24 ° C. and a relative humidity of 50% at a speed of 50 mm / min, and the adhesion of the tape was evaluated. 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 according to the following criteria. The results are shown in Table 1.
A: Peeling strength 5N / 5mm or more B: Peeling strength 3N / 5mm or more and less than 5N / 5mm C: Peeling strength smaller than 3N / 5mm

In Table 1, the notation of the colored layer (adhesive layer) indicates that the colored layer is composed of an adhesive layer containing a colorant.

As is clear from the results shown in Table 1, in the battery packaging materials of Examples 1 to 3 in which the B / A value is set in the range of 0.10 to 0.70, not only the electrolytic solution resistance but also the electrolytic solution resistance It can be seen that the printing characteristics of the ink are also excellent. Further, in the battery packaging materials of Examples 1 and 2 in which the B / A value is set in the range of 0.10 to 0.50, not only the electrolytic solution resistance and the printing characteristics of the ink but also the wear resistance. It turns out that it is also excellent. It can be seen that the battery packaging materials of Examples 4, 5 and 6 in which the filler is added to the resin composition forming the protective layer 6 are also excellent in tape adhesion. Further, in the packaging material for batteries of Examples 1-6, a colored layer was provided, and the distinguishability was better than in the case where the colored layer was not provided.

1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-sealing resin layer 5 Adhesive layer 6 Protective layer 7 Colored layer

Claims (11)

It is composed of a laminate having at least a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer in this order.
When measured from the outermost surface side of the protective layer by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis, the maximum value A of the absorbance detected in the range of 2800 cm ^-1 to 3000 cm ^{-1 and} 2200 cm- A packaging material for a battery, wherein the maximum value B of the absorbance detected in the range of ¹ to 2300 cm ^-1 satisfies the relationship of 0.05 ≦ B / A ≦ 0.75. The packaging material for a battery according to claim 1, wherein the colored layer is composed of an adhesive layer containing a colorant. The packaging material for a battery according to claim 1, wherein an adhesive layer is provided between the colored layer and the barrier layer. The battery packaging material according to any one of claims 1 to 3, wherein the protective layer contains a compound having an isocyanate group. 1. The protective layer comprises a urethane resin formed of at least one polyol selected from the group consisting of a polyester polyol having a group having a hydroxyl group in a side chain and an acrylic polyol, and a compound having an isocyanate group. The packaging material for a battery according to any one of 4 to 4. The battery packaging material according to any one of claims 1 to 5, which is used by printing ink on at least a part of the surface of the protective layer. The packaging material for a battery according to any one of claims 1 to 6, wherein an information carrying portion made of ink is provided on at least a part of the surface of the protective layer. The packaging material for a battery according to any one of claims 1 to 7, which has an adhesive layer between the barrier layer and the heat-sealing resin layer. The battery packaging material according to any one of claims 1 to 8, wherein the barrier layer is aluminum foil. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of claims 1 to 9. At least, a laminating step of laminating a protective layer, a base material layer, a colored layer, a barrier layer, and a heat-sealing resin layer to obtain a laminated body.
The curing step of curing the protective layer and
Equipped with
In the curing step, the maximum value of the absorbance detected in the range of 2800 cm ^-1 to 3000 cm ^-1 when the infrared wave number is measured from the outermost surface side of the protective layer by the attenuated total reflection of the Fourier transform infrared spectroscopic analysis method. The protective layer so that A and the maximum value B of the absorbance detected in the range of 2200 cm ^-1 to 2300 cm ^-1 in the infrared wave number satisfy the relationship of 0.05 ≤ B / A ≤ 0.75. A method of manufacturing packaging materials for batteries that cures.

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