JP2007161310A - Wrapping material for electronic component case, and case for electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wrapping material for an electronic component case showing a superior rigidity and capable of attaining a superior outer appearance with hardly allowing visual recognition of roll traces, scratches or the like on an aluminum foil even if a rolled trace or a scratch or the like is left at an aluminum foil. <P>SOLUTION: This wrapping material for electronic component cases comprises a heat-resistant resin oriented film layer 2 acting as an outer layer, a thermoplastic resin non-oriented film layer 3 acting as an inner layer, and an aluminum foil layer 4 arranged between these film layers. The aluminum foil layer 4 is made by laminating a hard aluminum foil 5 arranged at the inner layer 3 and an aluminum foil 6 on the outer layer 2 in which at least the outer layer is formed as a mat surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a packaging material for cases of electronic parts such as lithium ion secondary batteries and capacitors.

  In this specification and claims, the term “aluminum” is used to include aluminum and its alloys.

Lithium ion secondary batteries are widely used as power sources for notebook computers, video cameras, mobile phones, electric vehicles, and the like. As this lithium ion secondary battery, one having a configuration in which the periphery of the battery body is surrounded by a case is used. As the packaging material (101) for the case, for example, as shown in FIG. 5, an outer layer (102) made of a stretched polyamide film, a soft aluminum foil layer (104), and an inner layer (103) made of an unstretched polypropylene film are used. The thing of the structure integrally bonded and integrated in order is known (refer patent document 1).
JP 20016631 A

  By the way, recently, in some applications, a type in which the rigidity of the battery case packaging material is improved has been studied. In order to improve the rigidity as a battery case packaging material, the present inventor examined a configuration using a hard aluminum foil as the aluminum foil, and the rolling marks, scratches, etc. existing in the hard aluminum foil became conspicuous. It was found that there was a problem that the surface aesthetics were inferior.

  The present invention has been made in view of such a technical background, and is excellent in rigidity, and even if there are rolling eyes, scratches or the like on the aluminum foil, it is hardly noticeable and has a good appearance. An object of the present invention is to provide an electronic component case packaging material and an electronic component case that can be obtained.

  As a result of conducting a comparative survey with the soft aluminum foil conventionally used as the aluminum foil layer in order to investigate the cause of the appearance of the rolling marks and scratches present in the hard aluminum foil, the surface of the hard aluminum foil is It was found that because of the glossy surface, rolling marks, scratches and the like become conspicuous. That is, the soft aluminum foil conventionally used as the aluminum foil layer is generally manufactured by double rolling, so that one side (roll side) of the soft aluminum foil is glossy and the other side (superimposed side) is glossy. It is formed on the matte surface, and the matte surface is arranged on the outer layer side (heat-resistant resin stretched film layer side), so that even if there are rolling marks, scratches, etc. on the aluminum foil, it almost appears. Good appearance beauty was obtained. On the other hand, the hard aluminum foil employed in the present invention is intended to improve rigidity, so it must be formed to a certain degree of thickness, and therefore difficult to manufacture by double rolling, and both sides are rolls. It was found that the outer layer side of the hard aluminum foil becomes a glossy surface, so that rolling rolls and scratches are conspicuous. . As a result of earnestly researching means for reducing the gloss on the outer layer side of the hard aluminum foil while using the hard aluminum foil based on such cause investigation results, the present invention has been completed. That is, in order to achieve the above object, the present invention provides the following means.

  [1] A packaging material for an electronic component case, which includes a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and an aluminum foil layer disposed between the two film layers. The aluminum foil layer is a hard aluminum foil arranged on the inner layer side and an aluminum foil arranged on the outer layer side, and at least the outer layer side is formed on a matte surface (non-glossy surface). A packaging material for an electronic component case, characterized by comprising a laminate of aluminum foil.

  [2] A packaging material for an electronic component case, comprising: a heat-resistant resin stretched film layer as an outer layer; a thermoplastic resin unstretched film layer as an inner layer; and an aluminum foil layer disposed between the two film layers. The aluminum foil layer is formed by laminating a hard aluminum foil disposed on the inner layer side and a soft aluminum foil disposed on the outer layer side, and the soft aluminum foil is a double rolling method. A packaging material for an electronic component case, characterized in that the outer layer side of the soft aluminum foil is a matte surface (non-glossy surface).

  [3] A packaging material for an electronic component case, comprising a stretched heat-resistant resin film layer as an outer layer, an unstretched thermoplastic resin film layer as an inner layer, and an aluminum foil layer disposed between the two film layers. In this case, the aluminum foil layer is made of a hard aluminum foil, and the surface of the hard aluminum foil on the side of the outer layer is subjected to matting processing.

  [4] A packaging material for an electronic component case, comprising: a heat-resistant resin stretched film layer as an outer layer; a thermoplastic resin unstretched film layer as an inner layer; and an aluminum foil layer disposed between the two film layers. A packaging material for an electronic component case, wherein the aluminum foil layer is made of a hard aluminum foil, and at least one surface of the stretched heat-resistant resin film layer is matted.

  [5] The packaging material for electronic component cases according to any one of items 1 to 4, wherein the thickness of the hard aluminum foil is 50 to 200 μm.

  [6] An electronic component case obtained by molding the electronic component case packaging material according to any one of items 1 to 5.

  The term “hard aluminum foil” means a foil that has been processed (rolled) and work hardened. For example, a foil that has been hardened by work, a foil that has been subjected to appropriate heat treatment after work hardening, etc. Examples of the classification symbols HX1, HX2, HX3, HX4, HX5, HX6, HX7, HX8, HX9 generally used in the JIS standard (JIS H0001) (X: 1-3) It is done.

  Further, the term “soft aluminum foil” means an aluminum foil other than the hard aluminum foil, and examples thereof include a foil that has been softened by complete annealing, and is generally JIS standard (JIS H0001). What is called O material is mentioned.

  In the invention of [1], since a hard aluminum foil is used as the aluminum foil layer, a packaging material having excellent rigidity is provided. Also, as the aluminum foil disposed on the outer layer side, an aluminum foil having a matte surface at least on the outer layer side is used, so even if the aluminum foil has rolling eyes, scratches, etc., it is almost appearance. It is not noticeable and a good appearance can be obtained. Moreover, since what laminated | stacked the hard aluminum foil and the aluminum foil provided with the matte surface is used as an aluminum foil layer, it becomes the thing excellent in rigidity more as a packaging material. Furthermore, this packaging material has excellent resistance to electrolyte solution, and does not cause corrosion of the aluminum foil or leakage of the electrolyte solution, and is excellent in electrolyte solution resistance and gas barrier properties such as water vapor resistance. Suitable as a packaging material for cases.

  In the invention of [2], since the hard aluminum foil is used as the aluminum foil layer, a packaging material having excellent rigidity is provided. Moreover, since the soft aluminum foil arranged so that the outer layer side becomes a matte surface is laminated on the outer layer side with respect to the hard aluminum foil, even if there are rolling eyes, scratches, etc. on this aluminum foil A good appearance can be obtained without any noticeable appearance. Moreover, since what laminated | stacked the hard aluminum foil and the soft aluminum foil provided with the matte surface is used as an aluminum foil layer, it will become the thing excellent in rigidity more as a packaging material. Furthermore, this packaging material has excellent resistance to electrolyte solution, and does not cause corrosion of the aluminum foil or leakage of the electrolyte solution, and is excellent in electrolyte solution resistance and gas barrier properties such as water vapor resistance. Suitable as a packaging material for cases.

  In the invention of [3], since the hard aluminum foil is used as the aluminum foil layer, a packaging material having excellent rigidity is provided. In addition, since the surface of the outer layer side of the hard aluminum foil has been matted, even if the hard aluminum foil has rolling eyes, scratches, etc., it is hardly noticeable and has a good appearance Can be obtained. In addition, this packaging material has excellent resistance to electrolyte solution, and does not cause corrosion of the aluminum foil or leakage of the electrolyte solution, and also has excellent electrolyte solution resistance and gas barrier properties such as water vapor resistance. Suitable as a packaging material for cases.

  In the invention of [4], since a hard aluminum foil is used as the aluminum foil layer, a packaging material having excellent rigidity is provided. In addition, since at least one side of the heat-resistant resin stretched film layer that is the outer layer has been matted, even if the hard aluminum foil has rolling eyes, scratches, etc., it is hardly noticeable without appearance. A good appearance can be obtained. In addition, this packaging material has excellent resistance to electrolyte solution, and does not cause corrosion of the aluminum foil or leakage of the electrolyte solution, and also has excellent electrolyte solution resistance and gas barrier properties such as water vapor resistance. Suitable as a packaging material for cases.

  In the invention of [5], since the thickness of the hard aluminum foil is 50 to 200 μm, it is possible to ensure sufficient rigidity as a packaging material while maintaining light weight.

  The electronic component case according to the invention of [6] is excellent in rigidity, and even if the aluminum foil has rolling eyes, scratches, etc., it is hardly visible and does not stand out, and a good appearance case is provided. . In addition, it has excellent resistance to electrolytes, and does not cause corrosion of aluminum foil or leakage of electrolytes.It also has excellent resistance to electrolytes, and has excellent gas barrier properties such as water vapor resistance. is there.

  A first embodiment of a packaging material (1) for an electronic component case according to the present invention is shown in FIG. This packaging material is used as a packaging material for battery cases. The packaging material (1) has a heat-resistant resin stretched film layer (outer layer) (2) laminated and integrated on the upper surface of the aluminum foil layer (4) via an adhesive, and the aluminum foil layer (4). The thermoplastic resin unstretched film layer (inner layer) (3) is laminated and integrated on the lower surface of the resin layer via an adhesive. The aluminum foil layer (4) is composed of a hard aluminum foil (5) disposed on the inner layer (3) side and a soft aluminum foil (6) disposed on the outer layer (2) side. It consists of what was bonded and integrated. The said hard aluminum foil (5) is a foil manufactured by the single rolling method, and both surfaces are glossy surfaces. The soft aluminum foil (6) is made of a soft aluminum foil having one surface (roll side) produced by a double rolling method having a glossy surface and the other surface (overlapping surface side) being a matte surface, The matte surface is arranged so as to be the upper side (outer layer side) (6a) of the soft aluminum foil (6), and the glossy surface is the lower side (inner layer side) of the soft aluminum foil (6) (6b). ) (See FIG. 2). As shown in FIG. 6, the double rolling method is a rolling method in which two foils (30) and (30) are overlapped and rolled at the same time, and the overlapping surfaces (30a) ( 30a) becomes a matte surface, and the surface in contact with the rolling roll becomes a glossy surface.

  In the electronic component case packaging material (1) having the above-described configuration, since the hard aluminum foil (5) is used as a part of the aluminum foil layer (4), it is excellent in rigidity. Moreover, since the aluminum foil (6) provided with the matte surface is laminated | stacked on the outer layer side with respect to the hard aluminum foil (5), a rolling mark, an abrasion, etc. are carried out to aluminum foil (5) (6). Even if it exists, it is hardly conspicuous and it can obtain a good appearance. Moreover, this packaging material (1) is excellent in resistance to the electrolytic solution, and does not cause corrosion of the aluminum foil (4) or leakage of the electrolytic solution, and has excellent electrolytic solution resistance, and also has gas barrier properties such as water vapor resistance. Since it is excellent, it is suitable as a packaging material for battery cases.

  Although it does not specifically limit as an adhesive agent which adheres the said hard aluminum foil (5) and the said soft aluminum foil (6), It is preferable to use a polyamide-type adhesive agent and an epoxy-type adhesive agent, In this case, adhesive strength Can be improved.

  A second embodiment of a packaging material (1) for an electronic component case according to the present invention is shown in FIG. This packaging material is used as a packaging material for battery cases. In the packaging material (1), a heat resistant resin stretched film layer (outer layer) (2) is laminated and integrated on an upper surface of an aluminum foil layer (4) made of a hard aluminum foil (5) through an adhesive. The thermoplastic resin unstretched film layer (inner layer) (3) is laminated and integrated on the lower surface of the aluminum foil layer (4) via an adhesive. The said hard aluminum foil (5) is a foil manufactured by the single rolling method, and both surfaces are glossy surfaces. Matte printing is applied to the upper surface (outer layer side) of the hard aluminum foil (5). That is, in FIG. 3, (10) is a matte printing surface.

  In the packaging material (1) of FIG. 3, since the hard aluminum foil (5) is used as the aluminum foil layer (4), it has excellent rigidity. Further, since the matte printing is applied to the surface of the hard aluminum foil (4) on the outer layer side, even if the hard aluminum foil (4) has rolling eyes, scratches, etc., it hardly stands out. And good appearance beauty can be obtained.

  Examples of the matte printing include a method of printing a printing ink containing a matting agent such as colloidal silica or low molecular weight or medium molecular weight polyethylene on the surface of the hard aluminum foil (4). It is not limited to such a method, and any method can be used as long as the surface can be matted (processed).

  FIG. 4 shows a third embodiment of a packaging material (1) for an electronic component case according to the present invention. This packaging material is used as a packaging material for battery cases. In the packaging material (1), a heat resistant resin stretched film layer (outer layer) (2) is laminated and integrated on an upper surface of an aluminum foil layer (4) made of a hard aluminum foil (5) through an adhesive. The thermoplastic resin unstretched film layer (inner layer) (3) is laminated and integrated on the lower surface of the aluminum foil layer (4) via an adhesive. The said hard aluminum foil (5) is a foil manufactured by the single rolling method, and both surfaces are glossy surfaces. The upper surface of the heat-resistant resin stretched film layer (outer layer) (2) is matted. That is, in FIG. 4, (11) is a matte surface. In addition, this matting process may be given to the lower surface or both upper and lower surfaces of the said heat resistant resin stretched film layer (outer layer) (2).

  In the packaging material (1) of FIG. 4, since the hard aluminum foil (5) is used as the aluminum foil layer (4), it has excellent rigidity. In addition, since at least one surface of the heat resistant resin stretched film layer (2) which is the outer layer is subjected to matte processing, even if the hard aluminum foil (5) has rolling eyes, scratches, etc., it is almost appearance. Therefore, it is possible to obtain a good appearance beauty without being noticeable.

  The matting process is not particularly limited. For example, a technique of adding a matting agent such as colloidal silica or low molecular weight or medium molecular weight polyethylene to a heat resistant resin, a heat resistant resin stretched film layer (2 And a method of roughening the surface during film formation. Examples of the surface roughening treatment method include a method of transferring with a roll having a roughened surface.

  In this invention, the heat-resistant resin stretched film layer (outer layer) (2) is a member mainly responsible for ensuring good moldability as a packaging material, that is, breaking due to necking of the aluminum foil during molding. It plays a role to prevent. The heat-resistant resin stretched film (2) is not particularly limited, but a stretched film made of polyamide or polyester is preferably used. The thickness of the heat-resistant resin stretched film layer (2) is preferably set to 12 to 50 μm.

  The thermoplastic resin unstretched film layer (inner layer) (3) has excellent chemical resistance against highly corrosive electrolytes used in lithium ion secondary batteries, etc. It plays a role of imparting heat sealability. The thermoplastic resin unstretched film (3) is not particularly limited, but is at least one selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. It is preferable to use an unstretched film made of a thermoplastic resin. The thickness of the unstretched thermoplastic resin film layer (3) is preferably set to 20 to 80 μm. When the thickness is 20 μm or more, pinholes can be sufficiently prevented from being generated, and by setting the thickness to 80 μm or less, the amount of resin used can be reduced, and the cost can be reduced. Especially, it is especially preferable that the thickness of the said thermoplastic resin unstretched film layer (3) is set to 30-50 micrometers.

  The outer layer (2) and the inner layer (3) may both be a single layer or a multilayer.

  The aluminum foil layer (4) plays a role of imparting a gas barrier property to prevent oxygen and moisture from entering the packaging material. In the present invention, at least a part of the aluminum foil layer (4) is a hard aluminum foil. By using (5), sufficient rigidity and strength as the packaging material (1) can be secured.

  As said hard aluminum foil (5), the foil which consists of pure Al or an Al-Mn type alloy is used suitably, and it is preferable that thickness is 50-200 micrometers. When the thickness is 50 μm or more, sufficient rigidity can be secured, and when the thickness is 200 μm or less, the weight can be reduced. Especially, it is more preferable that the thickness of the said hard aluminum foil (5) is 80-150 micrometers, and especially suitable thickness is 100-120 micrometers.

  Moreover, when using a soft aluminum foil (6) together, as this soft aluminum foil (6), the foil of thickness 5-50 micrometers which consists of pure Al or an Al-Fe-type alloy is used suitably. Especially, it is especially preferable that the thickness of the said soft aluminum foil (6) is set to 15-50 micrometers.

  As an adhesive for bonding the aluminum foil layer (4) and the heat-resistant resin stretched film layer (2), an adhesive for bonding the aluminum foil layer (4) and the thermoplastic resin unstretched film layer (3). Although not particularly limited, for example, a urethane-based adhesive, an acrylic adhesive, an adhesive containing a thermoplastic elastomer, and the like can be given.

  An electronic component case can be obtained by molding the electronic component case packaging material (1) of the present invention. An electronic component such as a lithium battery can be obtained by enclosing an electronic component main body such as a battery such as a lithium ion secondary battery in the electronic component case.

  Next, specific examples of the present invention will be described.

<Example 1>
Manufactured by a double rolling method via a glue containing a polyamide-based adhesive and an epoxy-based adhesive on one side of a 120 μm thick hard aluminum foil (5) made of pure Al produced by a single rolling method A soft aluminum foil (6) having a thickness of 25 μm was bonded and integrated to obtain a laminated aluminum foil (4). At this time, the soft aluminum foil (6) was disposed and adhered so that the glossy surface was on the adhesion surface side (the matte surface was on the non-adhesion surface side).

  On the soft aluminum foil (6) of the laminated aluminum foil (4), a 25 μm thick heat-resistant stretched resin film (2) made of a polyethylene terephthalate film is laminated via a urethane resin adhesive, and the laminated aluminum foil (4) is laminated. By laminating a 35 μm-thick unstretched film (3) made of crystalline polypropylene on a hard aluminum foil (5) of an aluminum foil (4) with a urethane resin adhesive, a packaging material for electronic component cases (1 )

<Example 2>
Matte printing was performed on one surface of a 100 μm thick hard aluminum foil (5) made of an Al—Mn alloy produced by a single rolling method. As the matte printing ink, a printing ink containing colloidal silica as a matting agent was used. A 25 μm-thick heat-resistant stretched resin film (2) made of a polyethylene terephthalate film is laminated on the matte surface of the hard aluminum foil (5) with a urethane resin adhesive, and the hard aluminum foil ( A packaging material (1) for an electronic component case was obtained by laminating an unstretched film (3) made of crystalline polypropylene and having a thickness of 35 μm via a urethane resin adhesive on the non-printing surface of 5).

<Example 3>
One surface of a 100 μm thick hard aluminum foil (5) made of an Al—Mn alloy manufactured by a single rolling method is matted by a surface roughening treatment with a urethane resin adhesive. A laminated layer of a heat-resistant resin stretched film (2) having a thickness of 25 μm made of polyethylene terephthalate film and a thickness made of crystalline polypropylene via a urethane resin adhesive on the other surface of the hard aluminum foil (5). A packaging material (1) for an electronic component case was obtained by laminating an unstretched film (3) of 35 μm. The stretched film (2) was laminated so that the matte surface (11) was a non-laminated surface (see FIG. 4).

<Comparative Example 1>
A 25 μm thick heat-resistant resin stretched film made of polyethylene terephthalate film is laminated on one surface of a 120 μm thick hard aluminum foil via a urethane resin adhesive, and on the other surface of the hard aluminum foil. A packaging material was obtained by laminating an unstretched film made of crystalline polypropylene and having a thickness of 35 μm through a urethane resin adhesive.

  About each packaging material obtained as mentioned above, the surface appearance state was evaluated visually based on the following criteria.

“◯”: Rolled eyes and scratches are hardly visible, and the appearance is excellent. “X”: Rolled eyes, scratches, etc. can be markedly inferior, and the appearance is inferior.

  As is clear from Table 1, the packaging materials for electronic component cases of Examples 1 to 3 of the present invention were excellent in appearance appearance with almost no appearance even if the aluminum foil had rolling eyes or scratches. . On the other hand, the packaging material of Comparative Example 1 was inferior in appearance with a noticeable appearance of rolling marks and scratches.

  The packaging material for electronic component cases of the present invention is used as a packaging material for cases of electronic components such as lithium ion secondary batteries and capacitors.

It is sectional drawing which shows one Embodiment of the packaging material for electronic component cases which concerns on this invention. It is sectional drawing which shows each structural member of the packaging material of FIG. 1 in a separated state. It is sectional drawing which shows other embodiment of the packaging material for electronic component cases which concerns on this invention. It is sectional drawing which shows other embodiment of the packaging material for electronic component cases which concerns on this invention. It is sectional drawing which shows the structure of the conventional packaging material. It is explanatory drawing of a double rolling method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Packaging material for electronic component cases 2 ... Outer layer (heat-resistant resin stretched film layer)
3. Inner layer (thermoplastic resin unstretched film layer)
4 ... Aluminum foil layer 5 ... Hard aluminum foil 6 ... Soft aluminum foil 10 ... Matte printing surface 11 ... Matte processing surface

Claims (6)

In a packaging material for an electronic component case, including a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and an aluminum foil layer disposed between these two film layers,
The aluminum foil layer is formed by laminating a hard aluminum foil disposed on the inner layer side and an aluminum foil disposed on the outer layer side and at least the outer layer side formed on a matte surface. A packaging material for an electronic component case, characterized by comprising a thing. In a packaging material for an electronic component case, including a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and an aluminum foil layer disposed between these two film layers,
The aluminum foil layer is formed by laminating a hard aluminum foil arranged on the inner layer side and a soft aluminum foil arranged on the outer layer side,
The packaging material for an electronic component case, wherein the soft aluminum foil is a foil manufactured by a double rolling method, and is arranged so that an outer layer side of the soft aluminum foil becomes a matte surface. In a packaging material for an electronic component case, including a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and an aluminum foil layer disposed between these two film layers,
The packaging material for an electronic component case, wherein the aluminum foil layer is made of a hard aluminum foil, and a surface of the hard aluminum foil on the outer layer side is matted. In a packaging material for an electronic component case, including a heat-resistant resin stretched film layer as an outer layer, a thermoplastic resin unstretched film layer as an inner layer, and an aluminum foil layer disposed between these two film layers,
The packaging material for an electronic component case, wherein the aluminum foil layer is made of a hard aluminum foil, and at least one surface of the stretched heat-resistant resin film layer is matted.   The packaging material for an electronic component case according to any one of claims 1 to 4, wherein the thickness of the hard aluminum foil is 50 to 200 µm.   The case for electronic components obtained by shape | molding the packaging material for electronic component cases of any one of Claims 1-5.

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