JP7440997B2 - laminate material - Google Patents

Description

The present invention relates to a laminate material used for packaging power storage devices such as notebook computers, mobile phones, vehicle-mounted and stationary secondary batteries and capacitors, foods and pharmaceuticals, and related technologies.

In the claims and specification of the present application, the term "centerline average roughness (Ra)" means centerline average roughness (Ra) measured in accordance with JIS B0601-2001.

As the above-mentioned packaging material, a laminate material in which resin layers are bonded to both sides of metal foil is used. The above-mentioned laminate material can be formed into a three-dimensional shape by stretch molding or deep drawing to ensure a housing space for the case (see Patent Documents 1 and 2).

Therefore, it is possible to mold the product to fit the space where it will be used. However, in the case of secondary batteries, for example, the three-dimensional shape is created with the minimum necessary space, so it is possible to create a mold that is inadvertently connected to other circuits within the device housing. It is fixed with adhesive tape to prevent it from coming into contact with the

Patent No. 6249062 JP2003-288865A

By the way, the laminate material produced by bonding each layer is wound up into a roll and stored in the roll until it is molded. The inner resin layer of the laminate material contains a lubricant to prevent blocking, and the lubricant precipitates due to temperature, giving it smoothness. When the laminate material is rolled up into a roll, the outer resin layer, which is the outer surface of the case, and the inner resin layer, which is the inner surface of the case, are in contact with each other, so the lubricant that is blended into the inner resin layer and precipitated on the surface is transferred to the outer resin layer. be done. The lubricant transferred to the outer resin layer has the effect of increasing slipperiness when molding into a three-dimensional shape and is useful.

However, the lubricant that adheres to the outside surface of the finished product case reduces the adhesion of the adhesive tape, making it easier for the tape to peel off from the case, making it impossible to secure the case and potentially causing damage to the circuit.

In view of the background art described above, the present invention aims to provide a laminate material that controls the amount of lubricant transferred from the inner layer to the outer layer and does not reduce the adhesion of the adhesive tape.

That is, the present invention has the configurations described in [1] to [7] below.

[1] A laminate material including an outer layer, an inner layer, and a metal foil layer disposed between the outer layer and the inner layer,
The inner layer consists of one layer or multiple layers,
The innermost layer of the inner layer is made of a resin composition containing a heat-fusible resin and a lubricant and having a lubricant concentration of 1000 ppm to 5000 ppm,
The surface of the innermost layer of the inner layer is characterized by having one or more convex portions that are 0.3 μm or more higher than the reference height per 1 mm ² when the average value of the surface height is the reference height. laminate material.

[2] The laminate material according to item 1, wherein the area ratio of a portion of the surface of the innermost layer of the inner layer that is higher than the reference height by 0.3 μm or more is 20% to 80%.

[3] The laminate material according to item 1 or 2 above, wherein the center line average roughness Ra of the surface of the inner layer is 0.05 μm to 1 μm.

[4] The laminate material according to any one of items 1 to 3 above, wherein the lubricant contains at least an aliphatic amide.

[5] The heat-fusible resin of the resin composition constituting the innermost layer of the inner layer is mainly composed of a random copolymer containing propylene and a copolymer component other than propylene as a copolymer component. 4. The laminate material according to any one of 4.

[6] An exterior case made of a molded body of the laminate material according to any one of items 1 to 5 above.

[7] A power storage device main body,
An exterior member comprising the laminate material according to any one of the preceding clauses 1 to 5 and/or the exterior case for an electricity storage device according to the preceding clause 6,
An electricity storage device, wherein the electricity storage device main body is covered with the exterior member.

In the laminate material described in [1] above, the resin composition constituting the innermost layer of the inner layer contains 1000 ppm to 5000 ppm of a lubricant, and the surface of the innermost layer has convex portions that are 0.3 μm or more higher than the reference value per mm ^{2 .} It has one or more. Due to the uneven structure on the surface of the innermost layer of the inner layer, the innermost layer contacts the outer layer in dots, and the lubricant deposited on the surface of the innermost layer is transferred to the outer layer in dots, thereby suppressing the amount of transfer. By suppressing the amount of lubricant transferred, it is possible to impart slipperiness to the outer layer and prevent a decrease in adhesiveness of the adhesive tape.

The laminate material described in [2] above has an area ratio of 20% to 80% of the portion of the surface of the innermost layer that is 0.3 μm or more higher than the reference value, so the amount of lubricant transferred should be set to an appropriate value. Can be controlled.

Since the laminate material described in [3] above has surface irregularities with a center line average roughness Ra of 0.05 μm to 1 μm on the surface of the innermost layer of the inner layer, the amount of lubricant transferred can be controlled to an appropriate value.

Since the laminate material described in [4] above is an aliphatic amide in which the lubricant contained in the innermost layer of the inner layer is easily precipitated and easily transferred, it is significant to suppress the amount of transfer.

The laminate material described in [5] above is a random copolymer in which the heat-fusible resin of the resin composition constituting the innermost layer of the inner layer contains propylene as a copolymer component and another copolymer component other than propylene. Since it is soft, lubricant tends to precipitate on the surface. Therefore, even a low concentration of lubricant can be deposited on the surface, and it is easy to predict the amount of transfer based on the amount of precipitated lubricant.

The exterior case described in [6] above is a molded body of the laminate material described in any one of [1] to [5] above, and the innermost layer of the laminate material is a lubricant contained in the layer. The outer layer has good slipperiness, and the outer layer can maintain slipperiness and improve tape adhesion due to the lubricant transferred from the innermost layer.

According to the electricity storage device described in [7] above, since the amount of lubricant transferred from the innermost layer of the inner layer to the outer layer of the laminate material, which is the outer side of the exterior member, is suppressed, the adhesion of the adhesive tape is good. .

FIG. 1 is a cross-sectional view of one embodiment of a laminate material according to the present invention. It is a figure explaining the convex part of the surface of an inner layer. It is a figure explaining the number of convex parts on the surface of an inner layer. It is a figure explaining the number of convex parts on the surface of an inner layer. It is a sectional view of other embodiments of the laminate material concerning the present invention. 1 is a cross-sectional view showing an embodiment of a power storage device according to the present invention. 6 is an exploded perspective view of the electricity storage device of FIG. 5. FIG.

FIG. 1 shows an embodiment of the laminate material according to the present invention.

The laminate material 1 includes a heat-resistant resin layer 11 as an outer layer forming the outer surface of the case, a sealant layer 12 as an inner layer forming the inner surface of the case, and a metal foil layer 13 disposed between these layers. They are laminated and integrated via adhesive layers 14 and 15. The laminate material 1 is used as a secondary battery case material, and the sealant layer 12 has excellent chemical resistance even against highly corrosive electrolytes and the like, and also provides heat sealability to the laminate material 1. It is responsible for the role of Further, in the laminate material 1, the inner layer is a single layer of the sealant layer 12, and the sealant layer 12 corresponds to the innermost layer of the inner layers in the present invention.

[Innermost layer of inner layer]
The sealant layer 12 is made of a resin composition containing a heat-fusible resin and a lubricant, and the surface 12a has an uneven structure in which a large number of fine convex portions 20 are formed and the surface is roughened. When the sealant layer 12 and the heat-resistant resin layer 11 are overlapped, such as when the laminate material 1 is wound into a roll, the convex portions 20 on the surface 12a of the sealant layer 12 contact the heat-resistant resin layer 11 in a dotted manner. Therefore, the lubricant deposited on the surface 12a of the sealant layer 12 is transferred to the heat-resistant resin layer 11 in a dotted manner, giving the heat-resistant resin layer 11 slipperiness. Since the lubricant is transferred in dots, the amount of the lubricant transferred to the heat-resistant resin layer 11 is suppressed compared to when both are in close contact with each other. The decline can be prevented. If the amount of lubricant transferred to the heat-resistant resin layer 11 is 0.4 μg/cm ² or less, the adhesion of the adhesive tape is good, and it is more desirable if the amount is 0.3 μg/cm ² or less.

The present invention controls the transfer amount of the outer layer of lubricant by specifying the surface morphology of the innermost layer of the inner layer of the laminate material and the resin composition constituting the innermost layer.

(Surface morphology)
In the present invention, as shown in FIGS. 2, 3A, and 3B, the uneven structure of the surface 12a of the sealant layer 12 is defined as follows.

The sealant layer 12 has, on the surface 12a, at least one convex portion 20 per 1 mm ² which is higher than the reference height Hs by 0.3 μm or more, when the average value of the surface height H is the reference height Hs. The requirement is that the A surface having less than one convex portion 20 of such height is insufficiently roughened and is a relatively smooth surface, so that an excessive amount of lubricant in the sealant layer 12 is transferred. The number of the protrusions 20 is such that the number of vertices is 0.3 μm or more higher than the reference height Hs, and the depth of the valley between adjacent protrusions 20 does not matter. 3A and 3B are examples of cross-sectional views when the sealant layer 12 is cut along a plane P that is perpendicular to the thickness direction of the laminate material 1 and passes through a point 0.3 μm higher than the reference height Hs. FIG. 3A shows that four convex portions 20a are scattered in a plane area of 1 mm×1 mm, and the valleys between adjacent convex portions 20a are located at a position lower than the plane P. In FIG. 3B, four convex portions 20b exist in a plane area of 1 mm x 1 mm, the valleys between adjacent convex portions 20b are located at a higher position than the plane P, and the four convex portions 20b are connected in the plane P. It shows that there is. 3A and 3B both show that four convex portions 20a and 20b are present in a plane area of 1 mm×1 mm.

Further, in the present invention, as the degree of roughening of the surface of the sealant layer 12, the area ratio and surface roughness of a portion higher than the reference height Hs by 0.3 μm or more are defined as follows. By roughening the surface in a specified manner, the transfer amount of the lubricant can be controlled to an appropriate value, and it is possible to impart slipperiness to the heat-resistant resin layer 11 and prevent a decrease in adhesiveness of the adhesive tape.

On the surface of the sealant layer 12, it is preferable that the area ratio of a portion higher than the reference height Hs by 0.3 μm or more is 20% to 80%. Since FIGS. 3A and 3B are cross-sectional views at a plane P that is 0.3 μm higher than the reference height Hs, the parts that are 0.3 μm or more higher than the reference height Hs in these figures are the hatched parts. . A more preferable area ratio of the portion higher than the reference height Hs by 0.3 μm or more is 30% to 70%.

Further, the center line average roughness Ra of the surface 12a of the sealant layer 12 is preferably 0.05 μm to 1 μm, and more preferably the center line average roughness Ra is 0.1 μm to 1 μm.

Moreover, the uneven structure on the surface 12a of the sealant layer 12 has the effect of increasing slipperiness, and the slipperiness of the inner layer of the laminate material 1 is enhanced by both the lubricant and the uneven structure.

The method for forming the above-mentioned uneven structure will be described in detail later.

(Resin composition)
The sealant layer 12 is made of a resin composition containing a heat-fusible resin and a lubricant. The type of lubricant is not limited, and one or more types of aliphatic amide, aromatic amide, wax, silicone, paraffin, etc. can be used. Among these lubricants, aliphatic amide is easily transferred, and the application of the present invention has great significance in that the amount of transfer to the heat-resistant resin layer is suppressed by the sealant layer 12 having an uneven structure on the surface. The aliphatic amide is not particularly limited, and examples thereof include erucic acid amide, behenic acid amide, and the like. The lubricant concentration in the resin composition is 1000 ppm to 5000 ppm. When the lubricant concentration is less than 1000 ppm, the amount of transferred lubricant is small, so problems caused by the transferred lubricant are less likely to occur. On the other hand, since the lubricant concentration of 5000 ppm sufficiently increases the slipperiness during molding, a high concentration of lubricant exceeding 5000 ppm is uneconomical. A particularly preferred lubricant concentration is 1000 ppm to 3000 ppm.

The heat-fusible resin constituting the resin composition of the sealant layer 12 is not limited, but propylene and other copolymer resins other than propylene can be used as copolymerized resins that can improve slipperiness by depositing a lubricant on the surface. A compound whose main component is (contains 50% or more) a random copolymer containing a polymerization component (hereinafter abbreviated as "propylene random copolymer") can be recommended. Copolymerization components other than propylene are not particularly limited, but include olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene, and 4 - methyl-1-pentene. , butadiene, etc. Polypropylene has excellent chemical resistance and heat sealability, and the random copolymer is soft and easily deposits lubricant, and even low concentrations of lubricant can be deposited on the surface. Furthermore, it is easy to predict the amount of lubricant transferred to the heat-resistant resin layer 11 based on the amount of precipitated lubricant.

The polypropylene random copolymer preferably has a melt flow rate (MFR) at 230° C. in a range of 1 g/10 minutes to 10 g/10 minutes. By using the random copolymer having an MFR in the range of 1 g/10 min to 10 g/10 min, the roughening agent described below can be finely and uniformly dispersed, and the main body of the power storage device can be used as an exterior material. The sealing performance when sealing inside is improved, sufficient heat sealing strength is obtained, and reduction in the thickness of the sealant layer after heat sealing can be suppressed, and insulation properties can be further improved. When an ethylene-propylene random copolymer is used as the random copolymer, the ethylene content in the random copolymer is preferably 3% by mass to 7% by mass, and in this case, the relative temperature of about 200°C High heat-sealing strength can be obtained even if heat-sealing is performed at a relatively low heat-sealing temperature. Further, the melting point of the random copolymer is preferably in the range of 140°C to 155°C.

[Other laminated forms of inner layer]
The inner layer of the laminate material of the present invention is composed of one or more layers, and the conditions of the present invention described above are imposed on the surface morphology and resin composition of the innermost layer of the inner layer. Since the inner layer of the laminate material 1 in FIG. 1 is a single layer of the sealant layer 12, the sealant layer 12 is the innermost layer of the inner layer, and is subject to the uneven structure of the surface and the conditions of the resin composition. The laminate material 2 in FIG. 4 has a sealant layer 22 with a two-layer structure including an innermost layer 22a that becomes the inner surface of the case, and an intermediate layer 22b on the metal foil layer 13 side of the innermost layer 22a. Conditions are imposed. Note that the inner layer can also be composed of three or more layers.

As the resin constituting the intermediate layer 22b of the inner layer 22, it is preferable to use an elastomer-modified olefin resin. The elastomer-modified olefin resin (polypropylene block copolymer) is preferably composed of elastomer-modified homopolypropylene and/or elastomer-modified random copolymer. The elastomer-modified random copolymer is an elastomer-modified product of a random copolymer containing "propylene" and "other copolymer components other than propylene" as copolymer components; The "component" is not particularly limited, but includes, for example, olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene, and 4 - methyl-1-pentene, as well as butadiene. The elastomer is not particularly limited, but it is preferable to use an olefin thermoplastic elastomer. The olefin thermoplastic elastomer is not particularly limited, but examples include EPR (ethylene propylene rubber), propylene-butene elastomer, propylene-butene-ethylene elastomer, and EPDM (ethylene-propylene-diene rubber). Among them, it is preferable to use EPR (ethylene propylene rubber).

Regarding the elastomer-modified olefin-based resin, the "elastomer-modified" aspect may be one obtained by graft polymerization of an elastomer, or one in which an elastomer is added to an olefin-based resin (homopolypropylene or/and the random copolymer). or may be in other modified form.

[Method for forming uneven structure on the surface of the innermost layer]
Methods for forming an uneven structure on the surface of the innermost layer of the inner layer include, for example, adding a roughening agent to the inner resin layer, pressing a roll on which unevenness is formed to transfer the unevenness, or forming an uneven structure between the inner resin layer and metal foil. There are methods such as providing unevenness by gravure coating when applying the adhesive layer between the layers, and adding insoluble fine particles to the adhesive layer. Note that the method for forming the uneven structure is not limited to these methods.

[Materials of other layers]
The present invention does not limit the materials of each layer other than the inner layer, and they are appropriately selected depending on the use of the laminate material. The following are examples of preferred materials for the exterior case for power storage devices.

Note that the use of the laminate material of the present invention is not limited to exterior cases for power storage devices, but can also be suitably used as cases for foods, medicines, and the like.

(outer layer)
As the heat-resistant resin constituting the heat-resistant resin layer 11, a heat-resistant resin that does not melt at the heat-sealing temperature when heat-sealing the outer case is used. As the heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point higher than the melting point of the sealant layer 12 by 10° C. or more, and it is particularly preferable to use a heat-resistant resin having a melting point higher than the melting point of the sealant layer 12 by 20° C. or more. preferable.

The heat-resistant resin layer 11 is not particularly limited, but includes, for example, polyamide films such as nylon films, polyester films, etc., and stretched films of these are preferably used. Among them, the heat-resistant resin layer 11 may be a biaxially oriented polyamide film such as a biaxially oriented nylon film, a biaxially oriented polybutylene terephthalate (PBT) film, a biaxially oriented polyethylene terephthalate (PET) film, or a biaxially oriented polyethylene terephthalate (PBT) film. Particular preference is given to using phthalate (PEN) films. The nylon film is not particularly limited, and examples thereof include 6 nylon film, 6,6 nylon film, MXD nylon film, and the like. Note that the outer layer may be formed of a single layer, or may be formed of a multilayer consisting of, for example, a polyester film/polyamide film (a multilayer consisting of a PET film/nylon film, etc.). In addition, in the case of the multi-layer structure, it is preferable to arrange the polyester film side at the outermost side.

Alternatively, a protective layer may be laminated on the outside of the heat-resistant resin layer 11, and the protective layer may be the outermost layer of the outer layers.

(metal foil layer)
The metal foil layer 13 serves to provide a gas barrier that prevents oxygen and moisture from entering the case. The metal foil layer 13 is not particularly limited, but includes, for example, aluminum foil, SUS foil (stainless steel foil), copper foil, nickel foil, etc. Among them, it is preferable to use aluminum foil. The thickness of the metal foil layer 13 is preferably 15 μm to 100 μm. By having a diameter of 15 μm or more, it is possible to prevent the occurrence of pinholes during rolling when manufacturing metal foil, and by having a diameter of 100 μm or less, it is possible to reduce stress during forming such as stretch forming and drawing forming, thereby improving formability. be able to. Among these, the thickness of the metal foil layer 4 is more preferably 15 μm to 45 μm.

It is preferable that at least the inner surface (the surface on the sealant layer 12 side) of the metal foil layer 13 is subjected to a chemical conversion treatment. By performing such a chemical conversion treatment, corrosion of the metal foil surface by contents (such as battery electrolyte) can be sufficiently prevented. Examples of such chemical conversion treatment include chromate treatment.

(Adhesive layer)
The adhesive layer 14 between the metal foil layer 13 and the outer layer 11 is not particularly limited, but includes, for example, a polyurethane polyolefin adhesive layer, a polyurethane adhesive layer, a polyester polyurethane adhesive layer, a polyether polyurethane adhesive layer, etc. Examples include an adhesive layer and the like. The thickness of the outer adhesive layer 14 is preferably set to 1 μm to 6 μm.

The adhesive layer 15 between the metal foil layer 13 and the inner layer 12 is not particularly limited, and for example, the adhesive layer 14 exemplified as the outer adhesive layer 14 can also be used, but it may be difficult to swell with the electrolytic solution. It is preferred to use less polyolefin adhesive. Among these, it is particularly preferable to use acid-modified polyolefin adhesives. Examples of the acid-modified polyolefin adhesive include maleic acid-modified polypropylene adhesive, fumaric acid-modified polypropylene adhesive, and the like. The thickness of the adhesive layer 15 is preferably set to 1 μm to 5 μm.

[Electricity storage device]
As shown in FIGS. 5 and 6, a three-dimensional exterior case 31 can be obtained by molding (deep drawing, stretch molding, etc.) the laminate material 1 of the present invention. The sealant layer 12 of the laminate material 1 contains a lubricant, and since the lubricant of the sealant layer 12 is transferred to the heat-resistant resin layer 11, both surfaces have good slipperiness and good moldability. Note that the laminate material 1 can also be used as it is as the planar exterior material 32 without being subjected to molding.

5 and 6 show an embodiment of a power storage device 40 using the laminate material 1 of the present invention as the exterior member 30. This power storage device 40 is a lithium ion secondary battery. The exterior member 30 includes a three-dimensional exterior case 31 and a planar exterior member 32. A substantially rectangular parallelepiped-shaped power storage device main body (electrochemical element, etc.) 41 is housed in the housing recess of the exterior case 31, and the exterior material 32 is placed on top of the power storage device main body 41 as an inner layer (sealant layer). ) 12 side inward (lower side), and the peripheral edge of the inner layer 12 of the exterior material 32 and the inner layer (sealant layer) of the flange portion (sealing peripheral edge) 33 of the exterior case 31. 12 are sealed and sealed by heat sealing, thereby forming the electricity storage device 40. The inner surface of the housing recess of the exterior case 31 is an inner layer (sealant layer) 12, and the outer surface of the housing recess is an outer layer (heat-resistant resin layer) 11.

In FIG. 5, reference numeral 34 denotes a heat-sealed portion in which the peripheral edge of the exterior material 32 and the flange portion (sealing peripheral edge) 33 of the exterior case 31 are joined (fused). In addition, in the electricity storage device 40, the tip of the tab lead connected to the electricity storage device main body 41 is led out to the outside of the exterior member 30, but is not shown. The power storage device main body 41 is not particularly limited, and examples thereof include a battery main body, a capacitor main body, a capacitor main body, and the like.

The width of the heat seal portion 34 is preferably set to 0.5 mm or more. By setting it to 0.5 mm or more, sealing can be performed reliably. Among these, the width of the heat seal portion 34 is preferably set to 3 mm to 15 mm.

In the embodiment described above, the exterior member 30 is composed of the three-dimensional exterior case 31 and the planar exterior member 32, but the combination is not particularly limited to this. For example, the exterior member may be configured to include a pair of planar exterior materials 32, or may be configured to include a pair of three-dimensional exterior cases 31.

Next, specific examples of the laminate material of the present invention will be described, but the present invention is not particularly limited to these examples.

The laminate material produced in each example has a laminated structure as shown in FIG. 1, in which the outer layer is a single-layer heat-resistant resin layer 11 and the inner layer is a single-layer sealant layer 12.

(Examples 1 , 2, 5, Reference Examples 3, 4, 6, 7 , Comparative Example 2)
A chemical conversion treatment solution consisting of a trivalent chromium compound, water, and alcohol was applied to both sides of an aluminum foil 13 having a thickness of 35 μm in accordance with JIS H4160-A8079, and then dried at 180° C. to form a chemical conversion film. The amount of chromium deposited on this chemical conversion film was 2 mg/m ² per side.

Next, a polyester urethane resin adhesive is applied to one side of the chemical conversion treated aluminum foil 13 to form an adhesive layer 14 with a coating amount of 3.5 g/m ² after drying, and a heat-resistant As the resin layer 11, a biaxially stretched polyamide film having a thickness of 15 μm was bonded together by a dry lamination method.

Next, a polyacrylic adhesive was applied to the other surface of the chemical conversion treated aluminum foil 13 to form an adhesive layer 15, and an unstretched polypropylene film having a thickness of 30 μm was bonded to the adhesive layer 15 as a sealant layer 12. The unstretched polypropylene film is made of a resin composition based on an ethylene-propylene random copolymer and containing erucic acid amide as a lubricant and high-density polyethylene powder as a roughening agent at the concentrations shown in Table 1. The high-density polyethylene powder has an MFR of 0.2 g/10 min at 190°C, a density of 0.963 g/cm3, and a swell of 40%, and was manufactured by a slurry loop method using a Phillips catalyst. The average particle size is 0.5 μm.

(Comparative example 1)
The laminate material 1 was made using the same materials and methods as in Example 1, except that the resin composition constituting the unstretched polypropylene film as the sealant layer 12 contained 1000 ppm of erucic acid amide and did not contain a roughening agent. Created.

Each of the produced laminate materials 1 was wound up into a roll, and after being left at room temperature for 10 days, the following items were evaluated. The evaluation results are shown in Table 1.

(Surface morphology)
Each of the produced laminate materials was cut into a size of 10 mm x 10 mm, and the surface condition of the sealant layer 12 was observed using a scanning white interference microscope (VS1330) in an approximately 1 mm square area. The measurement conditions were a 5x (5x) two-beam interference objective lens, a wavelength filter of 520 nm, and Ra was determined. The area ratio was calculated by drawing a 0.3 μm contour line from the obtained distribution map and calculating the area by the gravimetric method.

(Transfer amount of lubricant)
The amount of lubricant adhering to the surface of the heat-resistant resin layer 11 was measured by the following method.

After cutting out two rectangular test pieces measuring 100 mm long x 100 mm wide from the laminate material 1, these two test pieces were stacked together so that the heat-resistant resin layer 11 (biaxially stretched polyamide film) was on the inside. After sealing each other's peripheral edges with PP tape, the three sides were secured with clips to prevent the seal from peeling off, thereby producing a bag body. 1 mL of acetone was injected into the internal space of this bag using a syringe, and the surface of the heat-resistant resin layer 11 was left in contact with the acetone for 3 minutes, after which the acetone inside the bag was extracted. By measuring and analyzing the amount of lubricant contained in this extracted liquid using a gas chromatograph, the amount of lubricant (mg/m ² ) present on the surface of the heat-resistant resin layer 11 is determined, and this is μg/cm ² It was converted into

(adhesive tape adhesion)
The laminate material 1 was cut into 150 mm x 150 mm to obtain a test piece. An adhesive tape with a width of 5 mm and a length of 100 mm was applied to the heat-resistant resin layer 11 of the test piece, and a roller weighing 2 kg was applied with a load to the adhesive tape and moved back and forth over the adhesive tape 5 times. Thereafter, it was allowed to stand at room temperature of 25° C. for 1 hour.

Regarding the adhesive tape attached to the test piece, in accordance with JIS K6854-3 (1999), using Strograph AGS-5kNX manufactured by Shimadzu Corporation, the test piece was narrowly fixed with one chuck and fixed with the other chuck. The adhesive tape was fixed, and the 180° peel strength was measured and evaluated based on the following criteria.

◎: Peel strength is 6 N/5 mm or more ○: Peel strength is 5 N/5 mm or more, but less than 6 N/5 mm ×: Peel strength is less than 5 N/5 mm

From Table 1, it was confirmed that by regulating the lubricant concentration and surface morphology in the sealant layer 12, it was possible to suppress the amount of lubricant transferred and maintain the adhesiveness of the adhesive tape.

The laminate material of the present invention can be used as a packaging material for power storage devices, foods, and medicines.

1, 2... Laminate material 11... Heat-resistant resin layer (outer layer)
12...Sealant layer (innermost layer of inner layer)
13...Metal foil layer 20, 20a, 20b...Convex portion 22...Inner layer 22a...Innermost layer Hs of inner layer...Reference height (average height)
30...Exterior member 31...Three-dimensional exterior case 32...Planar exterior material 40...Electricity storage device 41...Device body

Claims (7)

A laminate material comprising an outer layer, an inner layer, and a metal foil layer disposed between the outer layer and the inner layer,
The inner layer consists of one layer or multiple layers,
The innermost layer of the inner layer contains a heat-fusible resin, a lubricant, and a roughening agent, and has a lubricant concentration of 1000.
ppm to 3000 ppm, and consists of a resin composition with a roughening agent content of 1 wt% to 5 wt%,
The surface of the innermost layer of the inner layer has four or more convex portions that are 0.3 μm or more higher than the reference height per 1 mm ² when the average value of the surface height is the reference height,
The lubricant deposited on the surface of the innermost layer of the inner layer is transferred in dots onto the surface of the outer layer, and the amount of lubricant transferred is 0.4 μg/cm ² or less ,
The amount of lubricant transferred is determined by leaving acetone in contact with the surface of the outer layer for 3 minutes, wiping off the acetone, and measuring and analyzing the amount of lubricant contained in the wiped liquid using a gas chromatograph. A laminate material that is characterized by meeting the requirements of The laminate material according to claim 1, wherein the area ratio of a portion of the surface of the innermost layer of the inner layer that is higher than the reference height by 0.3 μm or more is 20% to 80%. The laminate material according to claim 1 or 2, wherein the center line average roughness Ra of the surface of the inner layer is 0.05 μm to 1 μm. The laminate material according to any one of claims 1 to 3, wherein the lubricant contains at least an aliphatic amide. Claims 1 to 4, wherein the heat-fusible resin of the resin composition constituting the innermost layer of the inner layer is mainly composed of a random copolymer containing propylene and a copolymer component other than propylene as a copolymer component. The laminate material according to any one of the above. An exterior case comprising a molded body of the laminate material according to any one of claims 1 to 5. A power storage device main body,
An exterior member comprising the laminate material according to any one of claims 1 to 5 and/or the exterior case for an electricity storage device according to claim 6,
An electricity storage device, wherein the electricity storage device main body is covered with the exterior member.

Images