CN110722848A

CN110722848A - Laminated material

Info

Publication number: CN110722848A
Application number: CN201910644214.5A
Authority: CN
Inventors: 南堀勇二
Original assignee: Showa Denko Packaging Co Ltd
Current assignee: Resonac Packaging Corp
Priority date: 2018-07-17
Filing date: 2019-07-16
Publication date: 2020-01-24
Also published as: TW202005799A; CN116442605A; KR20200008955A

Abstract

The present invention relates to a laminate. The transfer amount of the lubricant transferred from the inner layer to the outer layer of the laminate is controlled to prevent the adhesive tape from being reduced in adhesiveness. Laminated materialComprises an outer layer, an inner layer and a metal foil layer arranged between the outer layer and the inner layer. The first laminate is characterized in that the inner layer is formed of one or more layers, the innermost layer of the inner layer is formed of a resin composition containing a heat-fusible resin and a lubricant and having a lubricant concentration of 1000ppm to 5000ppm, and the average surface height of the innermost layer of the inner layer is 1mm per reference height²Has 1 or more convex parts higher than the standard height by 0.3 μm or more. The second laminate is one or more layers in which the outer layer is formed, and on the surface of the outermost layer of the outer layer, the average value of the surface heights is 1mm per reference height²The inner layer is formed of a resin composition containing a heat-fusible resin and a lubricant and having a lubricant concentration of 100ppm to 5000 ppm.

Description

Laminated material

Technical Field

The present invention relates to a laminate material used for packaging electric storage devices such as notebook personal computers, cellular phones, vehicles, stationary secondary batteries, and capacitors, foods, and pharmaceuticals, and a related technique thereof.

In the scope of the claims of the present application and the specification, the term "center line average roughness (Ra)" means the center line average roughness (Ra) measured according to JIS B0601-2001.

Background

As the packaging material, a laminate in which resin layers are laminated on both surfaces of a metal foil is used. The laminate is molded into a three-dimensional shape by bulging or deep drawing, thereby ensuring a housing space of the case (see patent documents 1 and 2).

In order to mold the resin layer into such a three-dimensional shape in a good state without pinholes, cracks, or the like, a lubricant is added to the resin layer on the side of the inner surface of the case, thereby improving the sliding property with respect to the molding tool (see patent document 2).

In addition, although the molding can be performed according to the space of the use site, in the case of a secondary battery, for example, since a three-dimensional shape is provided in a minimum necessary space, the battery is fixed by an adhesive tape so as not to be inadvertently brought into contact with other circuits in the housing of the device.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6249062

Patent document 2: japanese laid-open patent publication No. 2003-288865

Disclosure of Invention

Problems to be solved by the invention

However, the laminate produced by laminating the respective layers is wound around a roll and stored by the roll before molding. To prevent blocking, a lubricant is contained in the inner resin layer of the laminate, and the lubricant precipitates depending on the temperature, thereby imparting slidability. In the laminate wound around and superposed on the roll, the outer resin layer which is the outer surface of the case is in contact with the inner resin layer which is the inner surface, and therefore the lubricant which is blended in the inner resin layer and precipitated on the surface is transferred to the outer resin layer. The lubricant transferred to the outer resin layer has an effect of improving the sliding property when the resin is molded into a three-dimensional shape, and is useful.

However, since the lubricant adhering to the outer surface of the finished product case deteriorates the adhesion of the adhesive tape, the tape is easily peeled off from the case, and the case is not fixed any more, so that the inside of the circuit may be broken.

Means for solving the problems

In view of the background described above, an object of the present invention is to provide a laminate and a related technique thereof, in which the transfer amount of a lubricant transferred from an inner layer to an outer layer is controlled so as not to decrease the adhesiveness of an adhesive tape.

That is, the present invention has the following configurations [1] to [11 ].

[1] A laminate comprising an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer,

the inner layer is formed of one or more layers,

the innermost layer of the inner layer is formed by a resin composition which comprises a heat-fusible resin and a lubricant and has a lubricant concentration of 1000ppm to 5000ppm,

the surface of the innermost layer of the inner layers is 1mm per 1mm when the average surface height is taken as the reference height²Has 1 or more convex parts higher than the standard height by 0.3 μm or more.

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

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

[4] The laminate according to item 1 above, wherein the lubricant contains at least an aliphatic amide.

[5] The laminate as described in the above item 1, wherein the heat-fusible resin of the resin composition constituting the innermost layer of the inner layers has a random copolymer as a main component, and the random copolymer contains propylene and another copolymerizable component other than propylene as copolymerized components.

[6] A laminate comprising an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer,

the outer layer is formed of one or more layers,

on the surface of the outermost layer of the outer layer, the average value of the surface height is set as the reference height, and every 1mm²Has 1 or more convex parts higher than the standard height by 0.2 μm or more,

the inner layer is formed of a resin composition containing a heat-fusible resin and a lubricant, and having a lubricant concentration of 100ppm to 5000 ppm.

[7] The laminate according to item 6 above, wherein the area ratio of a portion of the outermost surface of the outer layer, which is higher by 0.2 μm or more than the reference height, is 20% to 80%.

[8] The laminate according to item 6 above, wherein the outer layer is bonded to the metal foil layer via an adhesive layer having irregularities on the outer layer side.

[9] The laminate according to item 6 above, wherein the outer layer is formed of a plurality of layers, and the outermost layer is a protective layer.

[10] An outer package case formed of a molded body of the laminate material described in any one of the preceding items 1 to 9.

[11] An electricity storage device, comprising:

an electric storage device main body section; and

an outer package member formed of the laminate according to any one of the above items 1 to 9 and/or the outer package casing for an electric storage device according to the above item 10,

the power storage device main body is externally coated with the outer coating member.

ADVANTAGEOUS EFFECTS OF INVENTION

As described in [1] above]The laminate is characterized in that the resin composition constituting the innermost layer of the inner layer contains 1000ppm to 5000ppm of a lubricant per 1mm of the surface of the innermost layer²Has 1 or more convex parts which are 0.3 μm or more higher than a reference value. The innermost layer is in contact with the outer layer in a dot shape due to the uneven structure of the innermost layer surface of the inner layer, and the lubricant deposited on the surface of the innermost layer is transferred to the outer layer in a dot shape, thereby suppressing the transfer amount. Further, by suppressing the transfer amount of the lubricant, it is possible to provide slidability to the outer layer and prevent the adhesive tape from being reduced in adhesion.

The laminate according to [2] above, wherein the area ratio of a portion of the surface of the innermost layer of the inner layer, which portion is higher than a reference value by 0.3 μm or more, is 20% to 80%, and therefore the transfer amount of the lubricant can be controlled to an appropriate value.

The laminate according to [3] above, which has surface irregularities having a center line average roughness Ra of 0.05 to 1 μm of the surface of the innermost layer of the inner layer, can control the transfer amount of the lubricant to an appropriate value.

The laminate according to the above [4], in which the lubricant contained in the innermost layer of the inner layer is an aliphatic amide which is likely to be deposited and transferred, is significant in terms of the amount of transfer.

In the laminate according to [5], the heat-fusible resin of the resin composition constituting the innermost layer of the inner layer is a soft random copolymer containing propylene and another copolymerized component other than propylene as copolymerized components, and therefore the lubricant is likely to be deposited on the surface. Therefore, even a lubricant having a low concentration can be deposited on the surface, and the transfer amount can be easily predicted based on the deposition amount of the lubricant.

As described in [6] above]The laminate is characterized in that the resin composition constituting the inner layer contains 100ppm to 5000ppm of a lubricant per 1mm of the outermost surface²Has 1 or more convex parts which are 0.2 μm or more higher than a reference value. The outermost layer is in contact with the inner layer in a dot shape by the uneven structure of the outermost surface of the outer layer, and is deposited on the surface of the innermost layerThe lubricant on the surface is transferred in dots to the outer layer, thereby generating a region where the lubricant does not exist, so that the transfer amount can be suppressed. Further, by suppressing the transfer amount of the lubricant, it is possible to provide slidability to the outer layer and prevent the adhesive tape from being reduced in adhesion.

The laminate according to [7] above, wherein the area ratio of a portion of the outermost surface of the outer layer, which portion is 0.3 μm or more higher than a reference value, is 20% to 80%, and therefore the transfer amount of the lubricant can be controlled to an appropriate value.

The laminate according to [8], wherein the irregularities of the surface of the pressure-sensitive adhesive layer, which can be easily molded by a coating method or by application of an additive, are reflected on the surface of the outer layer, thereby obtaining the surface morphology of the intended outermost layer and further easily controlling the amount of lubricant transferred.

According to the invention as recited in the above item [9], in the laminate having the protective layer as the outermost layer of the outer layer, the effect of the laminate as recited in the above item [6] can be obtained.

The exterior case according to [10] above, which is a molded article of the laminate according to any one of [1] to [9], wherein the innermost layer of the inner layer has good slidability due to a lubricant contained in the layer, and the outer layer has good tape adhesion while maintaining the slidability due to the lubricant transferred from the innermost layer.

According to the electricity storage device described in the above [11], the amount of the lubricant transferred from the innermost layer of the inner layer to the outer side of the outer cover member, that is, the outer layer of the laminate is suppressed, and therefore the adhesive tape has good adhesion.

Drawings

FIG. 1 is a cross-sectional view of an embodiment of a first laminate according to the present invention.

FIG. 2 is a view illustrating a convex portion on the surface of the inner layer.

Fig. 3A is a diagram illustrating the number of projections on the inner layer surface.

Fig. 3B is a diagram illustrating the number of projections on the inner layer surface.

FIG. 4 is a cross-sectional view of another embodiment of the first laminate according to the present invention.

FIG. 5 is a cross-sectional view of an embodiment of a second laminate according to the present invention.

FIG. 6 is a view illustrating a convex portion on the outer layer surface.

Fig. 7A is a diagram illustrating the number of projections on the outer layer surface.

Fig. 7B is a diagram illustrating the number of projections on the outer layer surface.

FIG. 8 is a cross-sectional view of another embodiment of the second laminate according to the present invention.

Fig. 9 is a cross-sectional view showing an embodiment of an electric storage device according to the present invention.

Fig. 10 is an exploded perspective view of the power storage device of fig. 9.

Description of the reference numerals

1. 2, 3, 4

A heat-resistant resin layer (outer layer)

Sealing layer (innermost layer of inner layer)

A metal foil layer

20. 20a, 20b, 120a, 120b

Sealing layer (inner layer)

An innermost one of the inner layers

An outer package member

An outer packaging case of three-dimensional shape

Planar-shaped outer packaging material

Electric power storage device

Device body

A heat-resistant resin layer (outer layer or outermost layer of outer layer)

Sealing layer (inner layer)

Protective layer (outermost layer of outer layer)

Reference height (average height) of convex portion of innermost layer

Reference height of convex part (average height) of outermost layer

Detailed Description

The laminate of the present invention can be broadly divided into two types. The two laminates have a common structure including an outer layer, an inner layer, and a metal foil layer disposed between the outer layer and the inner layer. In the first laminate, the inner layer is formed of one or more layers, and the resin composition constituting the innermost layer of the inner layer and the convex portion of the innermost layer are defined. In the second laminate, the outer layer is formed of one or more layers, and the resin composition constituting the inner layer and the convex portion of the outermost layer of the outer layer are defined.

Two laminates are detailed below.

<1> first laminate

One embodiment of the first laminate is shown in fig. 1.

The laminate 1 is integrally laminated with a heat-resistant resin layer 11 as an outer layer forming an outer surface of the case, a sealing layer 12 as an inner layer forming an inner surface of the case, and a metal foil layer 13 disposed between the two layers 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 even against a highly corrosive electrolyte solution or the like and plays a role in imparting heat sealability to the laminate 1. In the laminate 1, the inner layer is a single layer of the sealing layer 12, and the lamination layer 12 corresponds to the innermost layer of the inner layer in the present invention.

[ innermost layer of inner layer ]

The sealing layer 12 is formed of a resin composition containing a heat-fusible resin and a lubricant, and has a rough surface structure in which a large number of fine protrusions 20 are formed on the surface 12 a. In a state where the laminate 1 is wound around a roll or the like and the sealing layer 12 is overlapped with the heat-resistant resin layer 11, the sealing layer 12 is in contact with the heat-resistant resin layer 11 in a dot shape by the convex portions 20 on the surface 12 a. Therefore, the lubricant deposited on the surface 12a of the sealing layer 12 is transferred in a dot shape to the heat-resistant resin layer 11, and the heat-resistant resin layer 11 is provided with slidability. By causing the above-mentioned lubricant to be transferred in dots,therefore, compared with the case of adhesion between the heat-resistant resin layer and the adhesive tape, the amount of transfer to the heat-resistant resin layer 11 can be suppressed, and thus, the adhesion between the heat-resistant resin layer 11 and the adhesive tape can be prevented from being reduced by the lubricant. The amount of lubricant transferred to the heat-resistant resin layer 11 was 0.4. mu.g/cm²When the amount of the adhesive agent is less than the above range, the adhesiveness of the adhesive tape is good, and is 0.3. mu.g/cm²The following is more preferable.

In the first laminate, the surface morphology of the innermost layer of the inner layer and the resin composition constituting the innermost layer are defined, whereby the transfer amount of the outer layer of the lubricant is controlled.

(surface morphology)

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

The requirements of the sealing layer 12 are: at the surface 12a, the average value of the surface height HI was set as the reference height HIs every 1mm²The projection 20 has 1 or more projections having a height of 0.3 μm or more higher than the reference height HIs. When the number of the projections 20 having the height is less than 1, the surface is not sufficiently roughened and is relatively smooth, and therefore, the transfer amount of the lubricant in the seal layer 12 becomes excessive. The number of the projections 20 is the number of peaks higher than the reference height HIs by 0.3 μm or more, and is independent of the depth of the valley between adjacent projections 20. Fig. 3A and 3B are examples of cross-sectional views when the sealing layer 12 is cut by a plane PI perpendicular to the thickness direction of the laminate 1 and passing through a point 0.3 μm higher than the reference height HIs. Fig. 3A shows: 4 projections 20a are scattered in a plane area of 1mm × 1mm, and troughs between adjacent projections 20a are located at positions lower than the plane PI. Fig. 3B shows: 4 protrusions 20b are scattered in a plane area of 1mm × 1mm, valleys between adjacent protrusions 20b are located at a position higher than the plane PI, and the 4 protrusions 20b are connected in the plane P. Fig. 3A and 3B each show: in a planar area of 1mm × 1mm, there are 4

projections

20a, 20b.

In the present invention, the degree of roughening of the surface of the sealing layer 12 is defined as follows as the area ratio and the surface roughness of the portion higher by 0.3 μm or more than the reference height HIs. By the predetermined roughening, the transfer amount of the lubricant can be controlled to an appropriate value, and the heat-resistant resin layer 11 can be provided with slidability while preventing the adhesive tape from being deteriorated in adhesion.

The area ratio of the portion of the surface of the sealing layer 12 higher by 0.3 μm or more than the reference height HIs is preferably 20% to 80%. Since fig. 3A and 3B are cross-sectional views on the plane PI 0.3 μm higher than the reference height HIs, the portions higher than the reference height Hs by 0.3 μm or more in these figures are marked with oblique lines. A more preferable area ratio of a portion higher by 0.3 μm or more than the reference height HIs is 30% to 70%.

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

The uneven structure on the surface 12a of the sealing layer 12 has an effect of improving the sliding property, and the inner layer of the laminate 1 is improved in the sliding property by both the lubricant and the uneven structure.

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

(resin composition)

The sealing layer 12 is made of a resin composition containing a heat-fusible resin and a lubricant. The type of the lubricant is not limited, and 1 or more of aliphatic amide, aromatic amide, wax, silicone, paraffin, and the like can be used. Among these lubricants, the aliphatic amide is easy to transfer, and the application of the present invention, in which the amount of transfer to the heat-resistant resin layer is suppressed by the sealing layer 12 having the uneven structure on the surface, is significant. The aliphatic amide is not particularly limited, and examples thereof include erucamide and behenamide. The concentration of the lubricant in the resin composition is set to 1000ppm to 5000 ppm. When the lubricant concentration is less than 1000ppm, the transfer amount is small, and therefore, problems due to the transferred lubricant are not likely to occur. On the other hand, 5000ppm is not economical because the sliding property at the time of molding is sufficiently improved, and a high concentration of the lubricant exceeding 5000ppm is not preferable. Particularly preferred lubricant concentrations are from 1000ppm to 3000 ppm.

The heat-fusible resin of the resin composition constituting the sealing layer 12 is not limited, and as a resin capable of depositing a lubricant on the surface to improve the sliding property, a compound containing a random copolymer (hereinafter, simply referred to as "propylene random copolymer") containing propylene and another copolymerized component other than propylene as copolymerized components as a main component (including 50% or more) is recommended. The copolymerization components other than propylene are not particularly limited, and examples thereof include olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene and 4-methyl-1-pentene, and butadiene. Polypropylene is excellent in chemical resistance and heat sealability, and a random copolymer is soft and is easy to precipitate a lubricant, and can be precipitated on the surface even in the case of a low-concentration lubricant. In addition, the amount of transfer to the heat-resistant resin layer 11 can be easily predicted based on the amount of deposition of the lubricant.

The Melt Flow Rate (MFR) of the above-mentioned propylene random copolymer at 230 ℃ is preferably in the range of 1g/10 min to 10g/10 min. By using the random copolymer having an MFR within a range of 1g/10 min to 10g/10 min, a roughening material described later can be finely and uniformly dispersed, and the sealing property when sealing the electric storage device main body into the exterior material is improved, and a sufficient heat seal strength can be obtained, and the decrease in thickness of the seal layer after heat sealing can be suppressed, and the insulation property 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 to 7% by mass, and in this case, high heat seal strength can be obtained even when heat sealing is performed at a low heat seal temperature of about 200 ℃. The melting point of the random copolymer is preferably in the range of 140 to 155 ℃.

[ other lamination forms of inner layer ]

The inner layer of the first laminate is formed of one or more layers so that the surface morphology of the innermost layer of the inner layer and the resin composition satisfy the above-described conditions. The inner layer of the laminate 1 of fig. 1 is a separate layer of the sealing layer 12, and therefore, the sealing layer 12 becomes the innermost layer of the inner layer and satisfies the conditions of the uneven structure of the surface and the resin composition. The laminate 2 of fig. 4 is a sealing layer 22 having a two-layer structure of an innermost layer 22a on the inner surface of the case and an intermediate layer 22b on the metal foil layer 13 side of the innermost layer 22a, and the innermost layer 22a satisfies the conditions of the present invention. The inner layer may be composed of 3 or more layers.

As the resin constituting the intermediate layer 22b of the inner layer 22, an elastomer-modified olefin resin is preferably used. The elastomer-modified olefinic resin (polypropylene block copolymer) preferably contains an elastomer-modified homopolypropylene and/or an elastomer-modified random copolymer. The elastomer-modified random copolymer is an elastomer-modified random copolymer containing "propylene" and "another copolymerizable component other than propylene" as copolymerizable components, and the "another copolymerizable component other than propylene" is not particularly limited, and examples thereof include an olefin component such as ethylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene and butadiene. The elastomer is not particularly limited, and an olefin-based thermoplastic elastomer is preferably used. The olefinic thermoplastic elastomer is not particularly limited, and examples thereof include EPR (ethylene propylene rubber), propylene-butene elastomer, propylene-butene-ethylene elastomer, EPDM (ethylene-propylene-diene rubber), and the like, and among them, EPR (ethylene propylene rubber) is preferably used.

As for the elastomer-modified olefinic resin, as an aspect of "elastomer modification", an aspect in which an elastomer is graft-polymerized, an aspect in which an elastomer is added to an olefinic resin (homopolypropylene or/and the random copolymer), or another modification aspect may be employed.

[ method for Forming uneven Structure on surface of inner layer ]

As a method for forming the uneven structure on the surface of the innermost layer of the inner layer, for example, there is a method as follows: the inner resin layer is matched with a roughening material; pressing the roller with the concave-convex to transfer the concave-convex; providing unevenness by gravure coating when coating an adhesive layer between an inner resin layer and a metal foil layer; the adhesive layer is provided with irregularities by adding insoluble fine particles thereto. The method of forming the uneven structure is not limited to these methods.

<2> second laminate

One embodiment of the second laminate is shown in fig. 5.

The laminate 3 is integrally laminated with a heat-resistant resin layer 111 as an outer layer forming an outer surface of the case, a sealing layer 112 as an inner layer forming an inner surface of the case, and a metal foil layer 13 disposed between the two layers via

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 even against a highly corrosive electrolyte solution or the like, and plays a role in imparting heat sealability to the laminate 3. The sealing layer 112 is made of a resin composition containing a heat-fusible resin and a lubricant. In the laminate 13, the outer layer is a single layer of the heat-resistant resin layer 111, and therefore the heat-resistant resin layer 111 corresponds to the outermost layer of the outer layer in the present invention.

[ outermost layer of outer layer ]

The surface 111a of the heat-resistant resin layer 111 has a rough surface structure in which a large number of fine protrusions 120 are formed. In a state where the laminate 3 is wound around a roll or the like and the sealing layer 112 and the heat-resistant resin layer 111 are superposed, the heat-resistant resin layer 111 is brought into contact with the sealing layer 112 in a dot shape by the convex portions 120 on the surface 111a thereof. Therefore, the lubricant deposited on the surface of the sealing layer 112 is transferred in a dot shape to the heat-resistant resin layer 111, and the heat-resistant resin layer 111 is provided with slidability. By transferring the lubricant in a dot form, the amount of transfer to the heat-resistant resin layer 111 can be suppressed as compared with the case of adhesion between the heat-resistant resin layer and the adhesive tape, and thus, the adhesion between the heat-resistant resin layer 111 and the adhesive tape can be prevented from being lowered by the lubricant. The amount of lubricant transferred to the heat-resistant resin layer 111 was 1.0. mu.g/cm²When the amount of the adhesive agent is less than the above range, the adhesiveness of the adhesive tape is good, and is 0.3. mu.g/cm²The following is more preferable.

In the second laminate, the surface form of the outermost layer of the outer layer and the resin composition constituting the inner layer are specified, whereby the transfer amount of the lubricant in the outer layer is controlled.

(surface morphology)

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

The heat-resistant resin layer 111 has the following requirements: on the surface 111a, the average value of the surface height HO is set as a reference height Hs, every 1mm²Has 1 or more projections 120 having a height of 0.2 μm or more higher than the reference height HOs. When the number of the projections 120 having the height is less than 1, the surface is not sufficiently roughened and is relatively smooth, and therefore, the transfer amount of the lubricant in the sealing layer 112 becomes excessive. The number of the projections 120 is the number of peaks higher than the reference height HOs by 0.2 μm or more, and is independent of the depth of valleys between adjacent projections 120. Fig. 7A and 7B are examples of cross-sectional views obtained by cutting the heat-resistant resin layer 111 with 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: 4 projections 120a are scattered in a plane area of 1mm × 1mm, and valleys between adjacent projections 120a are located at a position lower than the plane PO. Fig. 7B shows: 4 protrusions 120b are scattered in a plane area of 1mm × 1mm, valleys between adjacent protrusions 120b are located at a position higher than a plane PO, and the 4 protrusions 120b are connected in the plane PO. Fig. 7A and 7B each show: in a planar area of 1mm × 1mm, there are 4 projections 120a, 120b.

In the present invention, the area ratio of the portion higher by 0.2 μm or more than the reference height HOs is defined as follows as the degree of roughening of the surface 111a of the heat-resistant resin layer 111. By the predetermined roughening, the transfer amount of the lubricant can be controlled to an appropriate value, and the heat-resistant resin layer 111 can be provided with slidability while preventing the adhesive tape from being deteriorated in adhesion.

The area ratio of the portion of the surface of the heat-resistant resin layer 111 higher by 0.2 μm or more than the reference height HOs is preferably 20% to 80%. Fig. 7A and 7B are cross-sectional views on a plane PO 0.2 μm higher than the reference height HOs, and therefore, in these figures, a portion 0.2 μm or more higher than the reference height HOs is marked by oblique lines. A more preferable area ratio of a portion higher by 0.2 μm or more than the reference height HOs is 30% to 70%.

The uneven structure on the surface 111a of the heat-resistant resin layer 111 also has an effect of improving the sliding property, and the outer layer of the laminate 1 is improved in sliding property by both the lubricant transferred from the sealing layer 112 and the uneven structure.

(composition of Heat-resistant resin layer)

As the heat-resistant resin constituting the heat-resistant resin layer (outer layer) 111, a heat-resistant resin that does not melt at a heat-sealing temperature when the exterior case is heat-sealed is used. As the heat-resistant resin, a heat-resistant resin having a melting point higher than the melting point of the sealing layer 12 by 10 ℃ or more is preferably used, and a heat-resistant resin having a melting point higher than the melting point of the sealing layer 12 by 20 ℃ or more is particularly preferably used.

The heat-resistant resin layer 111 is not particularly limited, and examples thereof include polyamide films such as nylon films, polyester films, and the like, and stretched films thereof can be preferably used. Among them, as the heat-resistant resin layer 111, 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 is particularly preferably used. The nylon film is not particularly limited, and examples thereof include a nylon 6 film, a nylon 6, 6 film, and an MXD nylon film. The outer layer may be formed as a single layer, or may be formed as a multilayer including a polyester film and a polyamide film (a multilayer including a PET film and a nylon film, for example). In the case of the multilayer, the polyester film side is preferably disposed on the outermost side.

(other lamination of outer layer)

The outer layer of the second laminate is formed of one or more layers such that the surface morphology of the outermost layer of the outer layer satisfies the above-described conditions. The outer layer of the laminate 3 in fig. 5 is a separate layer of the heat-resistant resin layer 111, and therefore, the heat-resistant resin layer 111 becomes the outermost layer of the outer layer and satisfies the condition of the uneven structure on the surface. The outer layer of the laminate 4 shown in fig. 8 is a two-layer structure in which the protective layer 122 is laminated on the outside of the heat-resistant resin layer 111, and the protective layer 122 as the outermost layer satisfies the surface form conditions of the present invention. The outer side may be formed of 3 or more layers.

As the protective layer 122, a resin such as a phenoxy resin, a urethane resin, an epoxy resin, or an acrylic resin is recommended. In addition, fine particles may be blended as a matting agent in these resins. As the fine particles, metal oxides such as silica and alumina, resin beads such as acrylic beads, and the like are recommended. The protective layer 122 may be formed by applying a liquid whose fluidity is adjusted by a solvent onto the heat-resistant resin layer 111 and drying the liquid, or may be formed by laminating the liquid onto the heat-resistant resin layer 111 in the form of a film.

[ inner layer ]

The sealing layer 112 is made of a resin composition containing a heat-fusible resin and a lubricant. The types of the heat-fusible resin and the lubricant are the same as those of the resin composition constituting the sealing layer 12 of the first laminate, but the lubricant concentration is different. The concentration of the lubricant in the resin composition constituting the sealing layer of the second laminate is set to 100ppm to 5000 ppm. When the lubricant concentration is less than 100ppm, the amount of transfer is also small, and thus sufficient sliding properties may not be obtained. On the other hand, since sufficient sliding properties are obtained, it is uneconomical to use a lubricant at a high concentration exceeding 5000ppm, and there is a possibility that the transfer is excessive and the transfer in a dot shape is not possible. Particularly preferred lubricant concentrations are 300ppm to 3000 ppm.

The inner layer may be formed of a plurality of layers. Of the inner layers composed of a plurality of layers, the innermost layer satisfies the conditions of the sealing layer 112 described above.

[ method for Forming uneven Structure on surface of outer layer ]

As in the case of the concave-convex structure on the surface of the inner layer, there is a method of: the outer layer is matched with a rough surface material; pressing the roller with the concave-convex to transfer the concave-convex; providing unevenness by gravure coating when coating an adhesive layer between an outer layer and a metal foil layer; the adhesive layer is provided with irregularities by adding insoluble fine particles thereto. The method of forming the uneven structure is not limited to these methods.

The details of the method of providing the unevenness to the pressure-sensitive adhesive layer in the above method are 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, when the surface of the adhesive layer 14 on the heat-resistant resin layer 111 side has irregularities, the film-shaped heat-resistant resin layer 111 superposed on the adhesive layer 14 deforms in accordance with the irregularities, and the irregularities of the adhesive layer 14 are reflected on the surface morphology of the heat-resistant resin layer 111. For example, in the step of the dry lamination method, when the coating thickness is finely changed by using a gravure roll and dried when the adhesive is applied to the metal foil layer 13, the adhesive layer 14 having irregularities on the surface is formed. Next, when the heat-resistant resin layer 111 is bonded, the convex portion 120 is formed on the surface 111a of the heat-resistant resin layer 11. As shown in fig. 8, when the protective layer 122 is laminated on the heat-resistant resin layer 111, a resin for a protective layer is applied to the heat-resistant resin layer 111 laminated on the metal foil layer 13, or a film in which the heat-resistant resin layer 111 and the protective layer 122 are integrated is prepared in advance and laminated on the metal foil layer 13 on which the adhesive layer 14 is laminated.

The above method is a method of reflecting the surface morphology of the adhesive layer on the outermost layer, and specifically, the surface morphology of the outermost layer is determined by the surface shape of the roll to which the adhesive is applied. According to this method, the surface morphology of the pressure-sensitive adhesive layer can be easily formed based on the surface shape of the roller, and the surface morphology of the intended outermost layer can be obtained. Further, the transfer amount of the lubricant can be easily controlled.

When the irregularities are formed on the surface of the inner layer, the irregularities are formed on the surface of the pressure-sensitive adhesive layer 15 on the inner layer side by the same method, and the surface morphology of the pressure-sensitive adhesive layer 15 is reflected on the innermost layer of the inner layer.

<3> materials of other layers of the first laminate and the second laminate

In the present invention, the material of each layer is not limited except that the inner layer is composed of a resin composition containing a heat-fusible resin and a lubricant, and is appropriately selected depending on the use of the laminate. The materials of the inner layer and the outer layer mentioned in "< 1> first laminate" and "< 2> second laminate" are examples of preferable materials for the outer casing for the electricity storage device, and hereinafter, a metal foil and an adhesive layer which are preferable for the outer casing for the electricity storage device will be described in detail. The laminate of the present invention is not limited to the outer casing for an electricity storage device, and can be suitably used as a casing for foods, pharmaceuticals, and the like.

The preferred material for the outer layer of the first laminate is in accordance with the material of the outer layer of the second laminate described above.

The metal foil layer 13 and the

adhesive layers

14 and 15 are common to the first and second laminates, and preferred materials of the respective layers are as follows.

(Metal foil layer)

The metal foil layer 13 plays a role of imparting gas barrier properties (preventing oxygen and moisture from entering the case). The metal foil layer 13 is not particularly limited, and examples thereof include an aluminum foil, a SUS foil (stainless steel foil), a copper foil, and a nickel foil, and among them, an aluminum foil is preferably used. The thickness of the metal foil layer 13 is preferably 15 μm to 100 μm. By setting the thickness to 15 μm or more, pinholes can be prevented from being generated at the time of rolling when the metal foil is manufactured, and by setting the thickness to 100 μm or less, stress at the time of forming such as bulging forming and drawing forming can be reduced, and formability can be improved. Among them, the thickness of the metal foil layer 4 is more preferably 15 μm to 45 μm.

The metal foil layer 13 is preferably subjected to chemical conversion treatment on at least the inner surface (the surface on the side of the sealant 12 or 112). By performing such chemical conversion treatment, corrosion of the surface of the metal foil due to the contents (electrolyte solution of the battery, etc.) can be sufficiently prevented. Examples of such chemical conversion treatment include chromate treatment and the like.

(adhesive layer)

The pressure-sensitive adhesive layer 14 between the metal foil layer 13 and the

outer layers

11 and 111 is not particularly limited, and examples thereof include a urethane polyolefin pressure-sensitive adhesive layer, a urethane pressure-sensitive adhesive layer, a polyester urethane pressure-sensitive adhesive layer, and a polyether urethane pressure-sensitive adhesive layer. The thickness of the outer pressure-sensitive 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 layers

12 and 112 is not particularly limited, and for example, a layer exemplified as the outer adhesive layer 14 may be used, and a polyolefin adhesive which is less swollen by an electrolyte solution is preferably used. Among these, the acid-modified polyolefin-based adhesive is particularly preferably used. Examples of the acid-modified polyolefin-based adhesive include a maleic acid-modified polypropylene adhesive and a fumaric acid-modified polypropylene adhesive. The thickness of the pressure-sensitive adhesive layer 15 is preferably set to 1 μm to 5 μm.

<4> outer casing and power storage device

As shown in fig. 9 and 10, the outer case 31 having a three-dimensional shape can be obtained by molding (deep drawing, bulging, etc.) the laminate of the present invention. The exterior case 31 illustrated in the figure is made of the first laminate 1 or the second laminate 3 described above. Since the sealing layers 12 and 112 of the laminates 1 and 3 contain a lubricant and the lubricant of the sealing layers 12 and 112 is transferred to the heat-resistant resin layers 11 and 111, both surfaces have good sliding properties and good moldability. The laminates 1 and 3 may be used as the planar outer cover 32 without being subjected to molding.

Fig. 9 and 10 show an embodiment of an electricity storage device 40 using the laminates 1 and 3 as the outer jacket member 30. The electric storage device 40 is a lithium ion secondary battery. The outer package member 30 is composed of a three-dimensional outer package case 31 and a planar outer package 32. The electric storage device 40 is configured such that an electric storage device main body portion (electrochemical element or the like) 41 having a substantially rectangular parallelepiped shape is housed in the housing recess of the outer case 31, the outer case 32 is disposed on the electric storage device main body portion 41 such that the inner layers (seal layers) 12 and 112 thereof face inward (downward), and the peripheral edge portions of the

inner layers

12 and 112 of the outer case 32 and the inner layers (seal layers) 12 and 112 of the flange portion (sealing peripheral edge portion) 33 of the outer case 31 are hermetically joined by heat sealing and sealed. The inner surfaces of the housing recesses of the outer case 31 are inner layers (sealing layers) 12 and 112, and the outer surfaces of the housing recesses are outer layers (heat-resistant resin layers) 11 and 111.

In fig. 9, reference numeral 34 denotes a heat-sealed portion formed by joining (welding) the peripheral edge portion of the outer package 32 to the flange portion (sealing peripheral edge portion) 33 of the outer case 31. In the above-described power storage device 40, the tip portions of the tabs connected to the power storage device body 41 are drawn out of the outer cover member 30, but are not shown in the drawings. The power storage device body 41 is not particularly limited, and examples thereof include a battery body, a capacitor body, and a capacitor body.

The width of the heat seal part 34 is preferably set to 0.5mm or more. By setting the thickness to 0.5mm or more, sealing can be reliably performed. The width of the heat-seal land 34 is preferably set to 3mm to 15 mm.

In the above embodiment, the outer jacket member 30 is configured to include the three-dimensional outer jacket shell 31 and the planar outer jacket material 32, but the combination is not particularly limited thereto. For example, the outer package member may be configured to include a pair of outer packages 32 having a planar shape, or may be configured to include a pair of outer packages 31 having a three-dimensional shape.

Examples

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

[1] First laminate

The laminate produced in each example was a laminate having a laminated structure as shown in fig. 1, and the outer layer was a single heat-resistant resin layer 11 and the inner layer was a single sealing layer 12.

(examples 1 to 7, comparative example 2)

A chemical conversion coating film was formed by applying a chemical conversion treatment liquid containing a trivalent chromium compound, water and an alcohol to both sides of a 35 μm thick aluminum foil 13 according to JIS H4160-A8079 and then drying the liquid at 180 ℃. The chromium deposition amount of the chemical conversion coating was 2mg/m per surface²。

Then, a polyester urethane resin adhesive was applied to one surface of the aluminum foil 13 on which the above-mentioned chemical conversion treatment was performed, to give a coating amount of 3.5g/m after drying²The pressure-sensitive adhesive layer 14 (2) was formed by bonding a biaxially stretched polyamide film having a thickness of 15 μm as the heat-resistant resin layer 11 by a dry lamination method.

Next, a polyacrylic adhesive was applied to the other surface of the aluminum foil 13 subjected to the chemical conversion treatment to form an adhesive layer 15, and an unstretched polypropylene film having a thickness of 30 μm was laminated as the sealing layer 12. The non-stretched polypropylene film was formed from a resin composition based on an ethylene-propylene random copolymer and containing erucamide as a lubricant and high-density polyethylene powder as a roughening material at concentrations shown in table 1. The high-density polyethylene powder has an MFR of 0.2g/10 min at 190 ℃ and a density of 0.963g/cm³The swelling was 40% and was produced using a Phillips catalyst and using the slurry circulation method, the average particle diameter of which was 0.5. mu.m.

Comparative example 1

Laminate 1 was produced by the same material and method as in example 1, except that the resin composition constituting the unstretched polypropylene film as seal layer 12 contained 1000ppm of erucamide and did not contain a roughening material.

Each laminate 1 thus produced was wound up on a roll and left at room temperature for 10 days, and then the following items were evaluated. The evaluation results are shown in table 1.

(surface morphology)

Each of the prepared laminates was cut into a size of 10mm × 10mm, and a surface state of about 1mm square was observed with respect to the surface of the sealing layer 12 using a scanning white interference microscope (VS 1330). The center line average roughness Ra was determined using a two-beam interference objective lens with 5 times (5X) behenamide and a wavelength filter of 520 nm. The area ratio of the convex portion was calculated by plotting a contour line of 0.3 μm from the obtained distribution chart and determining the area by a gravimetric method.

(transfer amount of Lubricant)

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

Two rectangular test pieces 100mm in length × 100mm in width were cut from the laminate 1, and the two test pieces were laminated so that the heat-resistant resin layer 11 (biaxially stretched polyamide film) was positioned inside, the peripheral ends of the two test pieces were sealed with a PP tape, and then 3 sides were fixed with clips so that the seal did not peel, to prepare a bag. Acetone was injected into the internal space of the bag body by a syringe in an amount of 1mL, the bag was left for 3 minutes in a state where the surface of the heat-resistant resin layer 11 was in contact with acetone, and then the acetone in the bag body was taken out. The amount of the lubricant contained in the extracted liquid was measured and analyzed by gas chromatography to determine the amount (mg/m) of the lubricant present on the surface of the heat-resistant resin layer 11²) And converting it into μ g/cm²。

(adhesive tape adhesion)

The laminate 1 was cut into pieces of 150mm × 150mm to prepare test pieces. An adhesive tape having a width of 5mm × a length of 100mm was attached to the heat-resistant resin layer 11 of the test piece, and the adhesive tape was reciprocated 5 times by applying a load to the adhesive tape with a roller having a weight of 2 kg. Then, the mixture was allowed to stand at room temperature of 25 ℃ for 1 hour.

The adhesive tape stuck on the test piece was evaluated by measuring 180 ° peel strength by holding and fixing the test piece with one chuck and fixing the adhesive tape with the other chuck by using Strograp AGS-5kNX manufactured by Shimadzu corporation according to JIS K6854-3(1999) and according to the following criteria.

◎ peel strength of 6N/5mm or more

○ peel strength of 5N/5mm or more and less than 6N/5mm

X: peeling strength less than 5N/5mm

[ Table 1]

As confirmed from table 1: by defining the concentration of the lubricant and the surface morphology in the sealing layer 12, the transfer amount of the lubricant can be suppressed, and the adhesion of the adhesive tape can be maintained.

[2] Second laminate

(examples 11 to 17, comparative example 12)

A laminate 3 having a laminate structure shown in fig. 5, i.e., a heat-resistant resin layer 111 having a single outer layer and a sealing layer 112 having a single inner layer was produced.

As the metal foil layer 13, an aluminum foil subjected to the same chemical conversion treatment as in example 1 was used.

Next, a polyester urethane resin adhesive was applied to one surface of the metal foil 13 using a gravure roll so as to minutely change the application thickness, and the adhesive layer 14 having irregularities on the surface was formed by drying the adhesive. The dry weight of the pressure-sensitive adhesive layer 14 in each example was 3.5g/m²The surface morphology of the gravure roll varies depending on the outer peripheral surface shape of the gravure roll. Next, a biaxially stretched polyamide film having a thickness of 15 μm was laminated as the heat-resistant resin layer 111 on the metal foil layer 13 on which the adhesive layer 14 was formed by a dry lamination method.

Next, a polyacrylic adhesive was applied to the other surface of the metal foil 13 to form an adhesive layer 15, and an unstretched polypropylene film having a thickness of 30 μm was laminated as the sealant 112. The above-mentioned unstretched polypropylene film was formed from a resin composition based on an ethylene-propylene random copolymer and containing erucamide as a lubricant at a concentration shown in table 2.

(examples 18 and 19, comparative example 13)

A laminate 4 having a laminate structure shown in fig. 8, i.e., a sealing layer 112 having two heat-resistant resin layers 111 and a protective layer 122 as outer layers and a single inner layer, was produced.

In the same manner as in example 11 and the like, the heat-resistant resin layer 111, the adhesive layer 14, the metal foil layer 13, the adhesive layer 15, and the sealing layer 112 were laminated. Next, a protective layer 122 is formed by applying a protective layer resin composition to the heat-resistant resin layer 111. The resin composition for protective layer 122 of example 18 was prepared by mixing a phenoxy resin and a polyurethane resin in the following ratio of 2: 3 in a mass ratio of 3. The resin compositions for protective layers of example 19 and comparative example 13 were prepared by adding silica having an average particle size of 2 μm to the resin mixture of example 18 in an amount of 10 wt%.

Comparative example 11

A laminate 3 was produced in the same manner as in example 11, except that the gravure roll was changed to a doctor blade as a method for forming the pressure-sensitive adhesive layer 14.

The

prepared laminates

3 and 4 were wound around rolls and left at room temperature for 10 days, and then the following items were evaluated. The evaluation results are shown in table 2.

(surface morphology)

Each laminate thus produced was cut into 10mm × 10mm, and the surface state of about 1mm square was observed with respect to the surface of the outermost layer of the outer layer using a scanning white interference microscope (VS 1330). The behenamide was set to 5 times (5X) of a two-beam interference objective lens, and the wavelength filter was 520 nm. The area ratio of the convex portion was calculated by plotting a contour line of 0.2 μm from the obtained distribution chart and determining the area by a gravimetric method.

(transfer amount of Lubricant)

The amount of the lubricant adhering to the outermost surface of the outer layer of each laminate thus produced was measured in the same manner as in the first laminate.

(adhesive tape adhesion)

The adhesive tape adhesion of each laminate thus produced was evaluated by the same method and the same reference as those for the first laminate.

As confirmed from table 2: by defining the surface morphology of the outermost layer of the outer layer and the concentration of the lubricant in the sealing layer 112, the amount of lubricant transferred can be suppressed, and the adhesion of the adhesive tape can be maintained

Industrial applicability

The laminate of the present invention is useful as a packaging material for electric storage devices, foods, and pharmaceuticals.

Claims

1. A laminate comprising an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer,

the inner layer is formed of one or more layers,

the innermost layer of the inner layer is formed of a resin composition containing a heat-fusible resin and a lubricant and having a lubricant concentration of 1000ppm to 5000ppm,

on the surface of the innermost layer of the inner layers, the average value of the surface height is set as a reference height, and every 1mm²Has 1 or more convex parts higher than the reference height by 0.3 μm or more.

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

3. The laminate according to claim 1, wherein the surface of the inner layer has a center line average roughness Ra of 0.05 μm to 1 μm.

4. The laminate of claim 1, wherein the lubricant comprises at least an aliphatic amide.

5. The laminate according to claim 1, wherein the heat-fusible resin of the resin composition constituting the innermost layer of the inner layers has a random copolymer as a main component, the random copolymer containing propylene and a copolymerizable component other than propylene as copolymerized components.

6. A laminate comprising an outer layer, an inner layer and a metal foil layer disposed between the outer layer and the inner layer,

the outer layer is formed of one or more layers,

on the surface of the outermost layer of the outer layer, the average value of the surface height is set as the reference height, and every 1mm²Has 1 or more convex parts higher than the reference height by 0.2 μm or more,

7. The laminate according to claim 6, wherein the area ratio of a portion higher by 0.2 μm or more than the reference height on the surface of the outermost layer of the outer layer is 20% to 80%.

8. The laminate according to claim 6, wherein the outer layer is bonded to the metal foil layer via an adhesive layer having irregularities on the outer layer side.

9. The laminate according to claim 6, wherein the outside layer is formed of a plurality of layers, and the outermost layer is a protective layer.

10. An outer package case formed of a molded body of the laminate material according to any one of claims 1 to 9.

11. An electricity storage device, comprising:

an electric storage device main body section; and

an outer package member formed of the laminate according to any one of claims 1 to 9 and/or the outer package casing for an electric storage device according to claim 10,

the power storage device main body portion is externally coated with the outer coating member.