TWI877115B - Laminated materials - Google Patents

Abstract

The present invention provides a laminated material, which can control the amount of lubricant transferred from the inner layer to the outer layer of the laminated material and prevent the adhesion of the adhesive tape from decreasing.

The present invention provides a laminated material, which includes an outer layer, an inner layer, and a metal foil layer disposed between the outer layer and the inner layer. In addition, the inner layer 12 of the first laminated material 1 is composed of one or more layers; the innermost layer 12 of the inner layer 12 is composed of a resin composition including a hot-melt resin and a lubricant, and the lubricant concentration is 1000ppm to 5000ppm; and the surface 12a of the innermost layer 12 of the inner layer 12 has one or more protrusions ²⁰ per 1mm2 that are 0.3μm or higher than the above-mentioned reference height when the average value of the surface height is used as the reference height. In addition, the outer layer of the second layer of the laminate is composed of one or more layers; the surface of the outermost layer of the outer layer has one or more protrusions per 1 ^mm2 that are 0.2 μm or more higher than the reference height when the average value of the surface height is used as the reference height; and the inner layer is composed of a resin composition including a hot-melt resin and a lubricant, and the lubricant concentration is 100 ppm to 5000 ppm.

Description

Laminated materials

The present invention relates to a laminated material used for packaging of power storage devices such as secondary batteries and capacitors for notebook computers, mobile phones, vehicles, and stationary devices, and food and medicines, and related technologies.

In addition, in the patent application scope and specification of this case, the term "center line average roughness (Ra)" refers to the center line average roughness (Ra) measured in accordance with JIS B0601-2001.

As the above-mentioned packaging material, a laminated material with resin layers attached to both sides of a metal foil is used. The laminated material is formed into a three-dimensional shape by stretching or deep drawing, thereby ensuring the storage space of the shell (refer to patent documents 1 and 2).

In order to prevent pinholes and cracks from occurring in such a three-dimensional shape and to form it in a good condition, a lubricant is added to the resin layer on the inner side of the shell to improve the sliding property relative to the forming tool (see Patent Document 2).

Furthermore, although it can be formed to fit the space of the location where it is used, in the case of a secondary battery, for example, since a three-dimensional shape is provided in the minimum necessary space, it is fixed with an adhesive tape to avoid accidental contact with other circuits in the housing of the device.

[Prior Technical Literature] 【Patent Literature】

[Patent document 1] Japanese Patent No. 6249062

[Patent Document 2] Japanese Patent Application Publication No. 2003-288865

In other words, the laminated material made by bonding the layers is rolled up by a roller and kept by the roller until the forming process is performed. The inner resin layer of the laminated material contains a lubricant to prevent agglomeration, and the lubricant precipitates with the temperature to provide sliding properties. The laminated material stacked and rolled up on the roller, because the outer resin layer as the outer surface of the shell and the inner resin layer as the inner surface are in contact, the lubricant that is mixed with the inner resin layer and precipitated on the surface will be transferred to the outer resin layer. The lubricant transferred to the outer resin layer has the effect of improving the sliding property when forming into a three-dimensional shape, and is useful.

However, the lubricant attached to the outer surface of the finished product shell will reduce the adhesion of the adhesive tape, so the adhesive tape is easily peeled off from the shell and cannot fix the shell, which may damage the inside of the circuit.

The present invention is based on the above-mentioned prior art and aims to provide a laminating material and related technology that can control the transfer amount of lubricant from the inner layer to the outer layer without reducing the adhesion of the adhesive tape.

That is, the present invention has the structure described in the following [1] to [11].

[1] A laminated material comprising an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer, wherein the inner layer is composed of one or more layers; the innermost layer of the inner layer is composed of a resin composition comprising a hot-melt resin and a lubricant, wherein the lubricant concentration is 1000ppm to 5000ppm; and the surface of the innermost layer of the inner layer has one or more protrusions per ^1mm2 that are higher than the reference height by 0.3μm or more when the average value of the surface height is used as the reference height.

[2] The laminated material as described in the preceding paragraph 1, wherein the area ratio of the portion of the surface of the innermost layer of the inner layer that is higher than the reference height by 0.3 μm is 20% to 80%.

[3] The laminated material as described in the preceding item 1, wherein the centerline average roughness Ra of the surface of the inner layer is 0.05 μm to 1 μm.

[4] The laminate as described in item 1 above, wherein the lubricant comprises at least aliphatic amide.

[5] The laminate as described in the above paragraph 1, wherein the hot-melt resin constituting the innermost resin composition of the inner layer is mainly composed of a random copolymer containing propylene and other copolymer components other than propylene as copolymer components.

[6] A laminated material comprising an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer, wherein the outer layer is composed of one or more layers; the surface of the outermost layer of the outer layer has one or more protrusions per 1 ^mm2 which are higher than the reference height by 0.2 μm or more when the average value of the surface height is taken as the reference height; and the inner layer is composed of a resin composition comprising a hot-melt resin and a lubricant, wherein the lubricant concentration is 100 ppm to 5000 ppm.

[7] The laminated material as described in item 6 above, wherein the area ratio of the portion of the surface of the outermost layer of the outer layer that is higher than the reference height by 0.2 μm is 20% to 80%.

[8] The laminated material as described in item 6 above, wherein the outer layer is bonded to the metal foil layer via an adhesive layer having a concave-convex surface on the side surface of the outer layer.

[9] The laminated material as described in item 6 above, wherein the outer layer is composed of a plurality of layers, and the outermost layer is a protective layer.

[10] An outer casing, characterized in that it is formed from a formed body of the laminated material as described in any one of Items 1 to 9 above.

[11] A power storage device characterized by comprising: a power storage device body and an exterior component formed by a laminate as described in any one of Items 1 to 9 and/or an exterior casing for a power storage device as described in Item 10; wherein the power storage device body is exteriorized by the exterior component.

The laminate described in [1] above has a resin composition constituting the innermost layer of the inner layer containing 1000ppm to 5000ppm of lubricant, and has one or more convex portions per ^1mm2 on the surface of the innermost layer that are 0.3μm or more higher than the reference value. By having such a concave-convex structure on the surface of the innermost layer of the inner layer, the innermost layer contacts the outer layer in a dot-like manner, so that the lubricant precipitated on the surface of the innermost layer is transferred to the outer layer in a dot-like manner, thereby suppressing the amount of transfer. Furthermore, by suppressing the amount of lubricant transferred, it is possible to impart slipperiness to the outer layer while preventing the adhesive tape from decreasing in adhesion.

In the laminated material described in [2] above, since the area ratio of the portion of the innermost surface of the inner layer that is 0.3 μm or more higher than the reference value is 20% to 80%, the amount of lubricant transferred can be controlled to an appropriate value.

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

In the laminated material described in [4] above, since the lubricant contained in the innermost layer of the inner layer is an aliphatic amide that is easy to precipitate and transfer, it is of great significance to suppress the transfer amount.

In the laminate described in [5] above, since the hot-melt resin constituting the innermost resin composition of the inner layer is a random copolymer containing propylene and other copolymer components other than propylene as copolymer components and is soft, the lubricant easily precipitates on the surface. Therefore, even a low concentration of lubricant can be precipitated on the surface, and the transfer amount can be easily predicted based on the amount of lubricant precipitated.

The laminate described in [6] above has a resin composition constituting the inner layer containing 100ppm to 5000ppm of lubricant, and the outermost layer has one or more convex portions per ^1mm2 that are 0.2μm or more higher than the reference value. By having such a concavo-convex structure on the outermost surface of the outer layer, the outermost layer contacts the inner layer in a dot-like manner, so that the lubricant precipitated on the surface of the innermost layer is transferred to the outer layer in a dot-like manner, thereby generating an area where no lubricant is present, thereby suppressing the amount of transfer. Furthermore, by suppressing the amount of lubricant transferred, it is possible to impart slipperiness to the outer layer while preventing a decrease in the adhesion of the adhesive tape.

In the laminated material described in [7] above, since the area ratio of the portion of the outermost surface of the outer layer that is 0.3 μm or more higher than the reference value is 20% to 80%, the amount of lubricant transferred can be controlled to an appropriate value.

In the laminated material described in [8] above, since the irregularities on the surface of the adhesive layer can be easily formed by coating or adding additives, and will be reflected on the surface of the outer layer, the expected surface morphology of the outermost layer can be obtained, and the transfer amount of the lubricant can be easily controlled.

According to the invention described in the above-mentioned [9], a laminated material having a protective layer as the outermost layer of the outer layer can obtain the effect of the laminated material described in the above-mentioned [6].

The outer casing described in [10] is a molded body of the laminated material described in any one of [1] to [9], wherein the innermost layer of the inner layer of the laminated material has good sliding properties due to the lubricant contained in the layer, and the outer layer can maintain sliding properties while improving the adhesion of the adhesive tape due to the lubricant transferred from the innermost layer.

According to the power storage device described in [11] above, the amount of lubricant transferred from the innermost layer of the inner layer to the outer layer of the laminated material serving as the outer side of the exterior component can be suppressed, thereby improving the adhesion of the adhesive tape.

1, 2, 3, 4...Layer Pressed Material

11. Heat-resistant resin layer (outer layer)

12‧‧‧Sealing layer (the innermost layer of the inner layer)

13. Metal foil layer

14, 15... Then the agent layer

20, 20a, 20b, 120, 120a, 120b‧‧‧Protrusion

22‧‧‧Sealing layer (inner layer)

22a‧‧‧Innermost layer of the inner layer

30‧‧‧Exterior parts

31. Three-dimensional outer shell

32‧‧‧Plane-shaped exterior materials

40‧‧‧Electrical storage device

41‧‧‧Device body

111‧‧‧Heat-resistant resin layer (outer layer or outermost layer of the outer layer)

112‧‧‧Sealing layer (inner layer)

122‧‧‧Protective layer (outermost layer)

HIs‧‧‧The base height of the innermost convex part (average height)

HOs‧‧‧The base height of the convex part of the outermost layer (average height)

[Fig. 1] A cross-sectional view of one embodiment of the first layer of the press material of the present invention.

【Fig. 2】A diagram illustrating the convex portion of the inner layer surface.

[Fig. 3A] A diagram illustrating the number of convexities on the inner layer surface.

FIG3B is a diagram illustrating the number of convexities on the inner layer surface.

[Fig. 4] A cross-sectional view of another embodiment of the first layer of the pressing material of the present invention.

[Fig. 5] A cross-sectional view of one embodiment of the second layer press material of the present invention.

[Fig. 6] A diagram illustrating the convex portion of the outer layer surface.

FIG. 7A is a diagram illustrating the number of convex portions on the outer layer surface.

FIG. 7B is a diagram illustrating the number of convex portions on the outer layer surface.

[Fig. 8] A cross-sectional view of another embodiment of the second layer press material of the present invention.

[Fig. 9] is a cross-sectional view showing one embodiment of the power storage device of the present invention.

[Figure 10] An exploded perspective view of the power storage device of Figure 9.

The laminated materials of the present invention can be roughly divided into two types. The common structure of the two laminated materials is: including an outer layer, an inner layer and a metal foil layer arranged between the outer layer and the inner layer. In addition, in the first laminated material, the inner layer is composed of one or more layers, and the resin composition constituting the innermost layer of the inner layer and the convex part of the innermost layer are specified. In addition, in the second laminated material, the outer layer is composed of one or more layers, and the resin composition constituting the inner layer and the convex part of the outermost layer are specified.

The two types of laminates are described in detail below.

<1> First layer of press material

One embodiment of the first layer of laminate is shown in FIG1 .

The laminate 1 includes a heat-resistant resin layer 11 as an outer layer forming the outer surface of the case, a sealing layer 12 as an inner layer forming the inner surface of the case, and a metal foil layer 13 disposed between the two layers, which are laminated and integrated via adhesive layers 14 and 15. The laminate 1 is used as a secondary battery case material, and the sealing layer 12 has excellent chemical resistance to highly corrosive electrolytes and the like, and also plays a role in giving the laminate 1 heat sealing properties. In addition, in the aforementioned laminated material 1, the inner layer is a single layer of the sealing layer 12, and the sealing layer 12 corresponds to the innermost layer of the inner layer of the present invention.

[Innermost layer of the inner layer]

The sealing layer 12 is made of a resin composition including a hot melt resin and a lubricant, and has a roughened concavo-convex structure with a large number of fine convex portions 20 formed on the surface 12a. When the sealing layer 12 and the heat-resistant resin layer 11 are superimposed, such as when the laminate 1 is rolled on a roll, the convex portions 20 on the surface 12a of the sealing layer 12 contact the heat-resistant resin layer 11 in a dot-like manner. As a result, the lubricant precipitated on the surface 12a of the sealing layer 12 is transferred to the heat-resistant resin layer 11 in a dot-like manner, thereby providing the heat-resistant resin layer 11 with sliding properties. By transferring the lubricant in a dot-like manner, the amount of the lubricant transferred to the heat-resistant resin layer 11 can be reduced compared to the case where the two are closely attached, so that the problem of decreased adhesion to the adhesive tape caused by the lubricant can be prevented on the surface of the heat-resistant resin layer 11. If the amount of the 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 if it is 0.3 μg/cm ² or less, it is more ideal.

The first layer of laminate controls the amount of lubricant transferred to the outer layer by defining the surface morphology of the innermost layer of the inner layer and the resin composition that constitutes the innermost layer.

(Surface morphology)

In the present invention, referring to FIG. 2 , FIG. 3A and FIG. 3B , the concavo-convex structure of the surface 12a of the sealing layer 12 is defined as follows.

The aforementioned sealing layer 12, in the surface 12a, is required to have one or more protrusions 20 per 1 ^mm2 that are 0.3 μm or more higher than the aforementioned reference height HIs when the average value of the surface height HI is taken as the reference height HIs. A surface having less than one protrusion 20 of such a height is not sufficiently roughened and is a relatively smooth surface, so the amount of lubricant transferred into the sealing layer 12 will be excessive. The number of the aforementioned protrusions 20 is the number of vertices that are 0.3 μm or more higher than the reference height HIs, regardless of the depth of the valley between adjacent protrusions 20. Figures 3A and 3B are examples of cross-sectional views when the sealing layer 12 is cut by a plane PI that is perpendicular to the thickness direction of the laminate 1 and passes through a point that is 0.3 μm higher than the reference height HIs. FIG3A shows that four convex portions 20a are scattered in a plane area of 1 mm×1 mm, and the valley between adjacent convex portions 20a is located at a position lower than the plane PI. FIG3B shows that four convex portions 20b exist in a plane area of 1 mm×1 mm, and the valley between adjacent convex portions 20b is located at a position higher than the plane PI, and the four convex portions 20b are connected on the plane P. Both FIG3A and FIG3B show that four convex portions 20a and 20b exist in a plane area of 1 mm×1 mm.

In addition, in the present invention, as the roughening degree of the surface of the sealing layer 12, the area ratio and surface roughness of the portion that is 0.3 μm or higher than the reference height HIs are specified as follows. The specified roughening can control the transfer amount of the lubricant to an appropriate value, and can provide the heat-resistant resin layer 11 with slipperiness while preventing the adhesive tape from decreasing in adhesion.

The area ratio of the portion of the surface of the sealing layer 12 that is 0.3 μm higher than the reference height HIs is preferably 20% to 80%. Since FIG. 3A and FIG. 3B are cross-sectional views of a plane PI that is 0.3 μm higher than the reference height HIs, the portion that is 0.3 μm higher than the reference height HIs in these figures is the portion with a diagonal line. The area ratio of the portion that is 0.3 μm higher than the reference height HIs is further preferably 30% to 70%.

In addition, the center line average roughness Ra of the surface 12a of the sealing layer 12 is preferably 0.05 μm to 1 μm, and the more preferred center line average roughness Ra is 0.1 μm to 1 μm.

In addition, the concavo-convex structure of the surface 12a of the sealing layer 12 has the effect of improving the sliding property, and the inner layer of the laminate 1 can improve the sliding property by both the lubricant and the concavo-convex structure.

The method for forming the above-mentioned concavo-convex structure is described in detail below.

(Resin composition)

The aforementioned sealing layer 12 is composed of a resin composition including a hot-melt resin and a lubricant. The type of lubricant is not limited, and one or more aliphatic amides, aromatic amides, waxes, silicones, waxes, etc. can be used. Among these lubricants, aliphatic amides are easy to transfer, and the application significance of the present invention is very large in that the amount of transfer to the heat-resistant resin layer is suppressed by the sealing layer 12 having a concave-convex structure on the surface. The aforementioned aliphatic amide is not particularly limited, and examples thereof include: mustard amide, behenyl amide, etc. The lubricant concentration in the aforementioned resin composition is 1000ppm~5000ppm. When the lubricant concentration is less than 1000ppm, the amount of transfer is small and the problem caused by the transfer of lubricant is not easy to occur. On the other hand, if it is 5000ppm, the slipperiness during molding is sufficiently improved, so a high concentration of lubricant exceeding 5000ppm is not economical. The optimal lubricant concentration is 1000ppm~3000ppm.

Although the hot-melt resin constituting the resin composition of the aforementioned sealing layer 12 is not limited, as a resin that can make the lubricant precipitate to the surface and improve the slipperiness, a compound containing propylene and other copolymer components other than propylene as copolymer components (hereinafter referred to as "propylene random copolymer") as the main component (containing more than 50%) is recommended. The aforementioned other copolymer components other than propylene are not particularly limited, for example: olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, etc., and butadiene, etc. can also be listed. Polypropylene has excellent chemical resistance and heat sealing properties, and the random copolymer is soft and easy to precipitate the lubricant, and even a low concentration of the lubricant can be precipitated to the surface. Furthermore, the amount of the lubricant transferred to the heat-resistant resin layer 11 can be easily predicted based on the amount of lubricant leached out.

The melt flow rate (MFR) of the aforementioned propylene random copolymer at 230°C is preferably in the range of 1 g/10 min to 10 g/10 min. By using the aforementioned random copolymer having an MFR in the range of 1 g/10 min to 10 g/10 min, the roughening material described later can be finely and uniformly dispersed. In addition, the sealing property when sealing the battery device body in the exterior material is improved to obtain sufficient heat sealing strength, and the thickness reduction of the sealing layer after heat sealing can be suppressed to further improve the insulation. As the aforementioned random copolymer, in the case of using an ethylene-propylene random copolymer, the ethylene content of the random copolymer is preferably 3% by mass to 7% by mass. In this case, even if heat sealing is performed at a relatively low heat sealing temperature of about 200°C, a high heat sealing strength can be obtained. In addition, the melting point of the random copolymer is preferably in the range of 140°C to 155°C.

[Other layer types of inner layers]

The inner layer of the first laminate is composed of one or more layers, and the surface morphology and resin composition of the innermost layer of the inner layer are subjected to the above-mentioned conditions. Since the inner layer of the laminate 1 of FIG. 1 is a single layer of the sealing layer 12, the sealing layer 12 is the innermost layer of the inner layer, and the surface concave-convex structure and the resin composition conditions are applied. The laminate 2 of FIG. 4 is a sealing layer 22 of a two-layer structure of the innermost layer 22a as the inner surface of the shell and the middle layer 22b on the side of the metal foil layer 13 of the innermost layer 22a, and the innermost layer 22a is subjected to the conditions of the present invention. Furthermore, the inner layer may be composed of three or more layers.

The resin constituting the middle layer 22b of the inner layer 22 is preferably an elastomer-modified olefin resin. The elastomer-modified olefin resin (polypropylene block copolymer) is preferably composed of an elastomer-modified homopolypropylene or/and an elastomer-modified random copolymer. The elastomer-modified random copolymer is an elastomer-modified random copolymer containing "propylene" and "other copolymer components other than propylene" as copolymer components; the "other copolymer components other than propylene" are not particularly limited, for example: olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, etc., in addition, butadiene, etc. can be listed. The aforementioned elastomer is not particularly limited, and preferably an olefinic thermoplastic elastomer is used. The aforementioned olefinic thermoplastic elastomer is not particularly limited, and examples thereof include EPR (ethylene propylene rubber), propylene-butylene elastomer, propylene-butylene-ethylene elastomer, EPDM (ethylene-propylene-diene rubber), etc. Among them, EPR (ethylene propylene rubber) is preferably used.

Regarding the aforementioned elastomer-modified olefinic resin, the state of "elastomer modification" may be a graft polymerization of elastomer, or an addition of elastomer to the olefinic resin (homopolymer polypropylene and/or the aforementioned random copolymer), or may be other modification states.

[Method for forming the concavo-convex structure on the inner layer surface]

Methods for forming the concavoconvex structure on the innermost surface of the inner layer include, for example, adding a roughening material to the inner resin layer, transferring the concavoconvex by pressing a roller formed with concavoconvex, providing the concavoconvex by gravure coating when applying the adhesive layer between the inner resin layer and the metal foil layer, providing the concavoconvex by adding insoluble particles to the adhesive layer, etc. The method for forming the concavoconvex structure is not limited to these methods.

<2> Second layer of press material

One embodiment of the second layer of laminate is shown in FIG5 .

The laminate 3 is formed by laminating a heat-resistant resin layer 111 as an outer layer forming the outer surface of the case, a sealing layer 112 as an inner layer forming the inner surface of the case, and a metal foil layer 13 disposed between the two layers through adhesive layers 14 and 15. The laminate 3 is used as a secondary battery case material, and the sealing layer 112 has excellent chemical resistance to highly corrosive electrolytes and the like, and also plays a role in giving the laminate 3 heat sealing properties. In addition, the sealing layer 112 is composed of a resin composition containing a hot-melt resin and a lubricant. In addition, in the aforementioned laminate 3, since the outer layer is a single layer of the heat-resistant resin layer 111, the heat-resistant resin layer 111 corresponds to the outermost layer of the outer layer of the present invention.

[Outermost layer of the outer layer]

The surface 111a of the heat-resistant resin layer 111 has a roughened concavoconvex structure formed with a large number of fine convex portions 120. When the sealing layer 112 and the heat-resistant resin layer 111 are superimposed on each other, such as when the laminate 3 is rolled on a roll, the convex portions 120 on the surface 111a of the heat-resistant resin layer 111 contact the sealing layer 112 in a dot-like manner. As a result, the lubricant precipitated on the surface of the sealing layer 112 is transferred to the heat-resistant resin layer 111 in a dot-like manner, thereby providing the heat-resistant resin layer 111 with sliding properties. By transferring the lubricant in a dot-like manner, the amount of the lubricant transferred to the heat-resistant resin layer 111 can be reduced compared to the case where the two are closely attached, so that the problem of reduced adhesion to the adhesive tape caused by the lubricant can be prevented on the surface of the heat-resistant resin layer 111. If the amount of the lubricant transferred to the heat-resistant resin layer 111 is 1.0 μg/ ^cm2 or less, the adhesion of the adhesive tape is good, and if it is 0.3 μg/ ^cm2 or less, it is more ideal.

The second layer of laminate controls the amount of lubricant transferred to the outer layer by defining the surface morphology of the outermost layer of the outer layer and the resin composition constituting the inner layer.

(Surface morphology)

In the present invention, referring to FIG. 6 , FIG. 7A and FIG. 7B , the concavo-convex structure of the surface 111a of the heat-resistant resin layer 111 is defined as follows.

The heat-resistant resin layer 111 is required to have one or more convex portions 120 per 1 ^mm2 on the surface 111a, when the average value of the surface height HO is taken as the reference height HOs, which is 0.2 μm or higher than the reference height HOs. A surface with less than one convex portion 120 of such a height is not sufficiently roughened and is a relatively smooth surface, so the amount of lubricant transferred to the sealing layer 112 will be excessive. The number of the convex portions 120 is the number of vertices that are 0.2 μm or higher than the reference height HOs, regardless of the depth of the valley between adjacent convex portions 120. Fig. 7A and Fig. 7B are examples of cross-sectional views of the heat-resistant resin layer 111 cut along a plane PO perpendicular to the thickness direction of the laminate 3 and passing through a point 0.2 μm higher than the reference height HOs. Fig. 7A shows that four convex portions 120a are scattered in a plane area of 1 mm×1 mm, and the valley between adjacent convex portions 120a is located at a position lower than the plane PO. Fig. 7B shows that four convex portions 120b exist in a plane area of 1 mm×1 mm, and the valley between adjacent convex portions 120b is located at a position higher than the plane PO, and the four convex portions 120b are connected on the plane PO. Fig. 7A and Fig. 7B both show that four convex portions 120a, 120b exist in a plane area of 1 mm×1 mm.

In addition, in the present invention, as the roughening degree of the surface 111a of the heat-resistant resin layer 111, the area ratio of the portion that is 0.2 μm or higher than the reference height HOs is specified as follows. The specified roughening can control the transfer amount of the lubricant to an appropriate value, and can provide the heat-resistant resin layer 111 with slipperiness while preventing the adhesive tape from decreasing in adhesion.

In the surface of the heat-resistant resin layer 111, the area ratio of the portion that is 0.2 μm higher than the reference height HOs is preferably 20% to 80%. Since FIG. 7A and FIG. 7B are cross-sectional views of a plane PO that is 0.2 μm higher than the reference height HOs, the portion that is 0.2 μm higher than the reference height HOs in these figures is the portion with a diagonal line. The area ratio of the portion that is 0.2 μm higher than the reference height HOs is further preferably 30% to 70%.

In addition, the concavo-convex structure of the surface 111a of the aforementioned heat-resistant resin layer 111 has the effect of improving the sliding property, and the outer layer of the aforementioned laminate 3 can improve the sliding property by both the lubricant transferred from the sealing layer 112 and the concavo-convex structure.

The method for forming the above-mentioned concavo-convex structure is described in detail below.

(Composition of heat-resistant resin layer)

The heat-resistant resin constituting the heat-resistant resin layer (outer layer) 111 is a heat-resistant resin that does not melt at the heat-sealing temperature when the outer casing is heat-sealed. The heat-resistant resin is preferably a heat-resistant resin having a melting point higher than that of the sealing layer 112 by 10°C or more, and particularly preferably a heat-resistant resin having a melting point higher than that of the sealing layer 112 by 20°C or more.

The aforementioned heat-resistant resin layer 111 is not particularly limited, and examples thereof include polyamide films such as nylon films, polyester films, and preferably, stretched films of the above are used. Among them, the aforementioned heat-resistant resin layer 111 is particularly preferably a biaxially stretched polyamide film such as a biaxially stretched nylon film, a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polyethylene terephthalate (PET) film, or a biaxially stretched polyethylene naphthalate (PEN) film. The aforementioned nylon film is not particularly limited, and examples thereof include 6 nylon film, 6,6 nylon film, MXD nylon film, and the like. The outer layer may be formed as a single layer or as a multilayer formed of, for example, polyester film/polyamide film (or a multilayer formed of PET film/nylon film). In the case of the multilayer, it is preferred that the polyester film side is disposed on the outermost side.

(Other layer types for the outer layer)

The outer layer of the second laminate is composed of one or more layers, and the surface morphology of the outermost layer of the outer layer is subjected to the above-mentioned conditions. Since the outer layer of the laminate 3 of FIG5 is a single layer of the heat-resistant resin layer 111, the heat-resistant resin layer 111 is the outermost layer of the outer layer, and the surface concave-convex structure condition is applied. The outer layer of the laminate 4 shown in FIG8 is an outer layer of a two-layer structure in which a protective layer 122 is laminated on the outer side of the heat-resistant resin layer 111, and the surface morphology condition of the present invention is applied to the protective layer 122 as the outermost layer. Furthermore, the outer layer may be composed of three or more layers.

The protective layer 122 may be made of phenoxy resin, polyurethane resin, epoxy resin, acrylic resin, or the like. In addition, microparticles may be added to these resins as a matting agent. The microparticles may be metal oxides such as silicon dioxide and aluminum oxide, resin beads such as acrylic resin beads, or the like. The protective layer 122 may be formed by applying a liquid having fluidity adjusted by a solvent to the heat-resistant resin layer 111 and then drying the liquid, or by laminating the heat-resistant resin layer 111 as a thin film.

[Inner layer]

The aforementioned sealing layer 112 is composed of a resin composition including a hot melt resin and a lubricant. Although the types of the aforementioned hot melt resin and lubricant are the same as the resin composition of the sealing layer 12 constituting the first layer of the press material, the lubricant concentration is different. The lubricant concentration in the resin composition constituting the sealing layer of the second layer of the press material is 100ppm~5000ppm. When the lubricant concentration is less than 100ppm, the transfer amount is small and therefore sufficient sliding property may not be obtained. On the other hand, a high lubricant concentration exceeding 5000ppm is not economical because sufficient slip is not achieved, and there is a possibility of over-transfer rather than dot transfer. The optimal lubricant concentration is 300ppm~3000ppm.

Furthermore, the inner layer may be composed of a plurality of layers. Among the inner layers composed of a plurality of layers, the conditions for the sealing layer 112 described above are applied to the innermost layer.

[Method for forming the concavo-convex structure on the outer layer surface]

The concavoconvex structure on the surface of the inner layer mentioned above includes the following methods: adding a roughening material to the outer layer, transferring the concavoconvex by pressing a roller with concavoconvex, applying the adhesive layer between the outer layer and the metal foil layer by gravure coating to provide the concavoconvex, adding insoluble particles to the adhesive layer to provide the concavoconvex, etc. The method of forming the concavoconvex structure is not limited to these methods.

In the above method, the method of providing the concavoconvexity in the adhesive layer is detailed as follows.

As shown in FIG. 5 , since the heat-resistant resin layer 111 is bonded to the metal foil layer 13 via the adhesive layer 14 , if there are irregularities on the surface of the heat-resistant resin layer 111 side of the adhesive layer 14 , the thin film-like heat-resistant resin layer 111 superimposed on the adhesive layer 14 will deform along with the irregularities, and the irregularities of the adhesive layer 14 will be reflected in the surface morphology of the heat-resistant resin layer 111 . For example, in the step of dry lamination, when the metal foil layer 13 is coated with adhesive, a gravure roller is used to slightly change the coating thickness, and then drying is performed to form an adhesive layer 14 with a concave-convex surface. Then, the heat-resistant resin layer 111 is attached, and a convex portion 120 is formed on the surface 111a of the heat-resistant resin layer 111. 8, in the case where the protective layer 122 is laminated on the heat-resistant resin layer 111, a protective layer resin is applied to the heat-resistant resin layer 111 bonded to the metal foil layer 13, or a film integrating the heat-resistant resin layer 111 and the protective layer 122 is prepared in advance and bonded to the metal foil layer 13 laminated with the adhesive layer 14.

The above method is a technique to reflect the surface morphology of the adhesive layer on the outermost layer. Specifically, the surface morphology of the outermost layer is determined by the surface shape of the roller that applies the adhesive. By using such a method, the surface morphology of the adhesive layer can be easily formed based on the surface shape of the roller, and the expected surface morphology of the outermost layer can be obtained. Furthermore, the transfer amount of the lubricant can be easily controlled.

In addition, in the case of forming the concavity and convexity on the surface of the inner layer, the concavity and convexity are formed on the surface of the adhesive layer 15 on the inner layer side by the same method, and the surface morphology of the adhesive layer 15 is reflected on the innermost layer of the inner layer.

<3>Materials of the first layer of pressed material and other layers of the second layer of pressed material

In the present invention, except that the inner layer is composed of a resin composition including a hot-melt resin and a lubricant, the materials of each layer are not limited and can be appropriately selected according to the purpose of the laminate. The materials of the inner layer and the outer layer listed in "<1> First layer laminate" and "<2> Second layer laminate" are examples of ideal materials for the outer casing of a storage device. The ideal metal foil and adhesive layer in the outer casing of a storage device are described in detail below. In addition, the use of the laminate of the present invention is not limited to the outer casing of a storage device, and can also be appropriately used as a casing for food, medicine, etc.

The ideal material of the outer side layer of the first layer of laminate shall be based on the material of the outer side layer of the second layer of laminate mentioned above.

In addition, the metal foil layer 13 and the adhesive layers 14 and 15 of the first and second layers of the pressing material are the same, and the ideal materials of each layer are as follows.

(Metal foil layer)

The aforementioned metal foil layer 13 plays the role of providing gas barrier properties to prevent oxygen and moisture from invading the shell. The aforementioned metal foil layer 13 is not particularly limited, and examples thereof include: aluminum foil, SUS foil (stainless steel foil), copper foil, nickel foil, etc., among which aluminum foil is preferably used. The thickness of the aforementioned metal foil layer 13 is ideally 15μm~100μm. By having a thickness of 15μm or more, pinholes can be prevented from being generated by interstitial pressure delay in manufacturing the metal foil. At the same time, by having a thickness of 100μm or less, the stress during forming such as stretch forming and elongation forming can be reduced, thereby improving the formability. Among them, the thickness of the aforementioned metal foil layer 13 is more preferably 15μm~45μm.

The metal foil layer 13 is preferably subjected to a chemical conversion treatment at least on the inner surface (the surface on the sealing layer 12, 112 side). By subjecting the metal foil layer 13 to such chemical conversion treatment, corrosion of the metal foil surface caused by the contents (electrolyte of the battery, etc.) can be sufficiently prevented. Examples of such chemical conversion treatment include chromate treatment.

(Following the agent layer)

The adhesive layer 14 between the metal foil layer 13 and the outer layers 11, 111 is not particularly limited, and examples thereof include polyurethane polyolefin adhesive layer, polyurethane adhesive layer, polyester polyurethane adhesive layer, polyether polyurethane adhesive layer, etc. 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, 112 is not particularly limited. For example, the adhesive layer 14 illustrated as the outer side may be used. However, it is desirable to use a polyolefin adhesive that has less swelling caused by the electrolyte. Among them, it is particularly desirable to use an acid-modified polyolefin adhesive. Examples of the acid-modified polyolefin adhesive include maleic acid-modified polypropylene adhesive and fumaric acid-modified polypropylene adhesive. The thickness of the adhesive layer 15 is ideally set to 1 μm to 5 μm.

<4>External casing and power storage device

As shown in Figures 9 and 10, by forming (deep drawing forming, stretching forming, etc.) the laminated material of the present invention, a three-dimensional exterior shell 31 can be obtained. The exterior shell 31 shown in the example is made of the first laminated material 1 or the second laminated material 3 mentioned above. Since the sealing layers 12 and 112 of the laminated materials 1 and 3 contain lubricants, and the heat-resistant resin layers 11 and 111 are transferred with the lubricants of the sealing layers 12 and 112, both sides have good sliding properties and good formability. In addition, the laminated materials 1 and 3 can also be used directly as a flat exterior shell 32 without being formed.

9 and 10 show an embodiment of a power storage device 40 using the laminated materials 1 and 3 as an exterior member 30. The power storage device 40 is a lithium ion secondary battery. The exterior member 30 is composed of a three-dimensional exterior case 31 and a planar exterior material 32. In addition, a storage device body (electrochemical element, etc.) 41 having a slightly rectangular shape is housed in the housing recess of the aforementioned outer casing 31, and the aforementioned outer casing material 32 is arranged on the upper side of the storage device body 41 in a manner such that the inner layer (sealing layer) 12, 112 side is the inner side (lower side), and the peripheral portion of the inner layer 12, 112 of the outer casing material 32 is sealed and joined to the inner layer (sealing layer) 12, 112 of the flange portion (sealing peripheral portion) 33 of the aforementioned outer casing 31 by heat sealing, thereby forming a storage device 40. Furthermore, the inner surface of the receiving recess of the aforementioned outer shell 31 is the inner layer (sealing layer) 12, 112, and the outer surface of the receiving recess is the outer layer (heat-resistant resin layer) 11, 111.

In FIG. 9 , 34 is a heat-sealed portion after the peripheral portion of the aforementioned exterior material 32 and the flange portion (sealing peripheral portion) 33 of the exterior shell 31 are joined (fused). In addition, in the aforementioned power storage device 40, although the front end portion of the tab connected to the power storage device body 41 is led out to the outside of the exterior component 30, it is omitted in the illustration. The aforementioned power storage device body 41 is not particularly limited, and examples thereof include: a battery body, a capacitor body, a condenser body, etc.

The width of the heat-sealed portion 34 is preferably set to be greater than 0.5 mm. By setting it to be greater than 0.5 mm, sealing can be performed reliably. Among them, the width of the heat-sealed portion 34 is preferably set to be 3 mm to 15 mm.

In the above embodiment, although the exterior component 30 is composed of a three-dimensional exterior shell 31 and a planar exterior material 32, it is not particularly limited to this combination. For example, the exterior component may be composed of a pair of planar exterior materials 32, or may be composed of a pair of three-dimensional exterior shells 31.

[Implementation Example]

Next, specific embodiments of the laminated material of the present invention are described, but the present invention is not particularly limited to these embodiments.

[1] First layer of press material

The laminated material produced in each example has a layered structure as shown in FIG1 , wherein the outer layer is a single-layer heat-resistant resin layer 11, and the inner layer is a single-layer sealing layer 12.

(Examples 1, 2, 5, Reference Examples 3, 4, 6, 7, Comparative Example 2)

A chemical treatment solution consisting of trivalent chromium compound, water and alcohol was applied to both sides of an aluminum foil 13 with a thickness of 35 μm in accordance with JIS H4160-A8079, and then dried at 180°C to form a chemical film. The chromium adhesion amount of the chemical film was 2 mg/m ² per side.

Next, a polyester polyurethane resin adhesive is coated on one side of the aluminum foil 13 that has completed the above-mentioned chemical treatment to form an adhesive layer 14 with a coating weight of 3.5 g/ ^m2 after drying, and a biaxially oriented polyamide film with a thickness of 15 μm is bonded as a heat-resistant resin layer 11 by dry lamination.

Next, a polyacrylic acid adhesive is applied to the other side of the aluminum foil 13 that has been subjected to the chemical treatment to form an adhesive layer 15, and a 30 μm thick unstretched polypropylene film is attached as a sealing layer 12. The unstretched polypropylene film is composed of a resin composition having an ethylene-propylene random copolymer as a base and containing erucic acid amide as a lubricant and high-density polyethylene powder as a roughening material at a concentration shown in Table 1. The high-density polyethylene powder has an MFR of 0.2 g/10 minutes at 190°C, a density of 0.963 g/ ^cm3 , and a swell of 40%. It is produced by a slurry loop method using a Phillips catalyst and has an average particle size of 0.5 μm.

(Comparison Example 1)

Except that the resin composition of the unstretched polypropylene film constituting the sealing layer 12 contains 1000 ppm of erucic acid amide and does not contain roughening material, the laminate 1 is made using the same materials and methods as those in Example 1.

Each layer of the prepared press material 1 was wound on a roller and placed at room temperature for 10 days, and then the following items were evaluated. The evaluation results are shown in Table 1.

(Surface morphology)

Each layer of the produced pressed material was cut into 10mm×10mm, and the surface state of the sealing layer 12 of about 1mm square was observed using a scanning white light interference microscope (VS1330). The measurement conditions were set to 5× double beam interference objective lens, wavelength filter: 520nm, and the center line average roughness Ra was obtained. The area ratio of the convex part was calculated by drawing a 0.3μm contour line from the obtained distribution map and obtaining the area by the weight method.

(Lubricant transfer amount)

The amount of lubricant adhering to the surface of the heat-resistant resin layer 11 is measured using the following method.

Two rectangular test pieces of 100 mm in length and 100 mm in width were cut out from the laminate 1, and the two test pieces were overlapped with the heat-resistant resin layer 11 (biaxially oriented polyamide film) as the inner side, and the peripheral ends of each other were sealed with PP tape, and then the three sides were fixed with clips so that the seal would not fall off to make a bag. 1 mL of acetone was injected into the inner space of the bag using a syringe, and the surface of the heat-resistant resin layer 11 was left in contact with the acetone for 3 minutes, and then the acetone in the bag was extracted. The amount of lubricant contained in the extract was measured and analyzed using a gas chromatograph to obtain the amount of lubricant present on the surface of the heat-resistant resin layer 11 (mg/m ² ), which was then converted into μg/cm ² .

(Adhesion of adhesive tape)

Cut the laminate 1 into 150mm×150mm pieces as test pieces. Paste an adhesive tape with a width of 5mm×length of 100mm on the heat-resistant resin layer 11 of the test piece, and apply weight to the adhesive tape with a 2kg roller and move it back and forth 5 times. Then, leave it at room temperature of 25℃ for 1 hour.

For the adhesive tape attached to the above test piece, according to JIS K6854-3 (1999), use the strograph AGS-5kNX manufactured by Shimadzu Corporation, clamp and fix the test piece with the chuck on one side, and fix the adhesive tape with the chuck on the other side, measure the 180° peel strength and evaluate it according to the following standards.

◎: Peeling strength is 6N/5mm or more

○: Peel strength is 5N/5mm or more and less than 6N/5mm

×: Peel strength less than 5N/5mm

Table 1 shows that by regulating the lubricant concentration and surface morphology in the sealing layer 12, the amount of lubricant transferred can be suppressed and the adhesion of the adhesive tape can be maintained.

[2] Second layer of press material

(Examples 11 to 17, Comparative Example 12)

A laminated material 3 with a layered structure as shown in FIG5 is manufactured, that is, a laminated material 3 with a single-layer heat-resistant resin layer 111 as the outer layer and a single-layer sealing layer 112 as the inner layer is manufactured.

The metal foil layer 13 uses aluminum foil that has been chemically treated, just like in Example 1.

Next, a polyester polyurethane resin adhesive is applied to one side of the metal foil 13 using a gravure roller to slightly change the coating thickness, and dried to form an adhesive layer 14 having a concave-convex surface. In addition, although the dry weight of the adhesive layer 14 in each example is 3.5 g/m ² , the surface morphology will vary depending on the outer peripheral shape of the gravure roller used. In addition, a biaxially oriented polyamide film with a thickness of 15 μm is bonded to the metal foil layer 13 formed with the adhesive layer 14 by dry lamination as a heat-resistant resin layer 111.

Next, a polyacrylic acid adhesive is applied to the other side of the metal foil 13 to form an adhesive layer 15, and a 30 μm thick unstretched polypropylene film is attached as a sealing layer 112. The unstretched polypropylene film is composed of a resin composition with an ethylene-propylene random copolymer as a base and containing erucamide as a lubricant at a concentration shown in Table 2.

(Examples 18, 19, Comparative Example 13)

A laminated material 4 having a layered structure as shown in FIG8 is manufactured, that is, a laminated material 4 having a heat-resistant resin layer 111 and a protective layer 122 as two layers on the outer side and a single-layer sealing layer 112 as the inner side.

By the same method as in Example 11, a heat-resistant resin layer 111, an adhesive layer 14, a metal foil layer 13, an adhesive layer 15, and a sealing layer 112 are laminated. Then, a protective layer resin composition is applied on the heat-resistant resin layer 111 to form a protective layer 122. The protective layer 122 resin composition of Example 18 is a mixture of phenoxy resin and polyurethane resin in a mass ratio of 2:3. The protective layer resin composition of Example 19 and Comparative Example 13 is a resin mixture of Example 18 with 10wt% of silica having an average particle size of 2μm.

(Comparison Example 11)

A laminated material 3 with a layered structure as shown in FIG5 is manufactured, that is, a laminated material 3 with a single-layer heat-resistant resin layer 111 as the outer layer and a single-layer sealing layer 112 as the inner layer is manufactured.

As a method for forming the subsequent agent layer 14, except for changing the gravure roller to a scraper, the other methods are the same as those in Example 11 to make the laminate 3.

The prepared laminated materials 3 and 4 were wound around rollers and left at room temperature for 10 days, and then evaluated for the following items. The evaluation results are shown in Table 2.

(Surface morphology)

Each layer of the laminate was cut into 10 mm x 10 mm, and the surface state of the outermost layer of the outer layer was observed using a scanning white light interference microscope (VS1330). The measurement conditions were set to a 5× double beam interference objective lens and a wavelength filter: 520 nm. The area ratio of the convex portion was calculated by drawing a 0.2 μm contour line from the obtained distribution map and obtaining the area by the weight method.

(Lubricant transfer amount)

The amount of lubricant attached to the outermost surface of each of the prepared press materials was measured in the same manner as for the first press material.

(Adhesive tape adhesion)

The adhesive tape adhesion of each layer of laminated material was evaluated in the same manner and using the same criteria as the first layer of laminated material.

It can be confirmed from Table 2 that by specifying the surface morphology of the outermost layer of the outer layer and the lubricant concentration in the sealing layer 112, the amount of lubricant transferred can be suppressed and the adhesion of the adhesive tape can be maintained.

【Industrial Utilization】

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

1.Layered material

11. Heat-resistant resin layer (outer layer)

12‧‧‧Sealing layer (the innermost layer of the inner layer)

12a‧‧‧Surface of sealing layer 12

13. Metal foil layer

14, 15... Then the agent layer

20‧‧‧convex part

Claims (10)

A laminated material comprises an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer, wherein the inner layer is composed of one or more layers; the innermost layer of the inner layer is composed of a resin composition comprising a hot-melt resin, a lubricant and a roughening material, and the lubricant concentration is 1000ppm to 3000ppm; and the surface of the innermost layer of the inner layer is 1000ppm to 1000ppm when the average value of the surface height is taken as the reference height. ² having two or more convex portions which are higher than the aforementioned base height by more than 0.3 μm; on the surface of the aforementioned outer layer, the lubricant precipitated to the surface of the innermost layer of the aforementioned inner layer is transferred in a dotted manner, the lubricant transfer amount is less than 0.4 μg/ ^cm2 , and there is an area on the surface of the aforementioned outer layer where the lubricant is not present. For the laminated material described in Item 1 of the patent application, the area ratio of the portion of the surface of the innermost layer of the inner layer that is higher than the reference height by 0.3μm is 20% to 80%. For the laminated material described in Item 1 of the patent application, the center line average roughness Ra of the surface of the aforementioned inner layer is 0.05μm~1μm. As described in item 1 of the patent application scope, the lubricant contains at least aliphatic amide. As described in the first item of the patent application scope, the hot-melt resin constituting the innermost resin composition of the aforementioned inner layer is mainly composed of a random copolymer containing propylene and other copolymer components other than propylene as copolymer components. A laminated material comprises an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer, wherein the outer layer is bonded to the metal foil layer via an adhesive layer having a concave-convex surface on the side of the outer layer; the outer layer is composed of one or more layers; the surface of the outermost layer of the outer layer has a surface height of 1 mm when the average surface height is taken as the reference height. ² having two or more convex portions that are 0.2 μm or more higher than the aforementioned base height; and the aforementioned inner layer is composed of a resin composition including a hot-melt resin and a lubricant, and the lubricant concentration is 100 ppm to 5000 ppm; on the surface of the aforementioned outer layer, the lubricant precipitated to the surface of the innermost layer of the aforementioned inner layer is transferred in a dot manner, and the lubricant transfer amount is 1.0 μg/cm ² or less, and there is an area on the surface of the outer layer where no lubricant is present; the peel strength of the adhesive tape relative to the outer layer is 5N/5mm or more, wherein the peel strength is measured in the following manner: the laminate is cut into 150mm×150mm pieces as test pieces, and an adhesive tape having a width of 5mm×a length of 100mm is attached to the outer layer of the test piece, and a 2kg roller is applied to the adhesive tape and moved back and forth on the adhesive tape 5 times, and then the tape is left to stand at room temperature of 25°C for 1 hour, and then the 180° peel strength is measured in accordance with JIS K6854-3(1999). For the laminated material described in Item 6 of the patent application, the area ratio of the portion of the surface of the outermost layer of the outer layer that is higher than the aforementioned reference height by 0.2μm is 20% to 80%. For example, the laminated material described in Item 6 of the patent application scope, wherein the outer layer is composed of a plurality of layers, and the outermost layer is a protective layer. An outer casing characterized in that it is formed of a laminated material as described in any one of items 1 to 8 of the patent application scope. A power storage device, characterized by comprising: a power storage device body, and an exterior component formed by a laminated material as described in any one of items 1 to 8 of the patent application scope and/or an exterior casing as described in item 9 of the patent application scope; and the power storage device body is exteriorized by the exterior component.

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