JP5010097B2 - Electronic component case packaging material, electronic component case and electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging material for an electronic component case having high molding ability, high gas barrier ability, high adhesion strength between layers, and high electrolyte resistance even under a high temperature condition, and to provide a case for an electronic component. <P>SOLUTION: In the packaging material for the electronic component case containing a heat resistant resin oriented film layer as an outside layer, a thermoplastic resin non-oriented film layer as an inside layer, and an aluminum foil layer arranged between both film layers, the aluminum foil layer has a primary film on one surface of at least the inside layer of an aluminum foil, and the primary film is a film formed by treating the surface of the aluminum foil with a substrate treatment agent containing chitosan and a metal compound containing one kind or more metals selected from a group comprising Ti, Hf, Mo, W, Se, Ce, Fe, Cu, Zn, V, and trivalent Cr. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

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

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 this case packaging material, for example, an outer layer / adhesive layer / aluminum foil / adhesive layer / inner layer made of a stretched polyamide film is laminated and integrated in order (see, for example, Patent Document 1). In the packaging material described in Patent Document 1, at least the inner layer side surface of the aluminum foil is subjected to an easy adhesion treatment by being treated with a treatment liquid containing a metal phosphate or the like. By such treatment, the adhesive strength between the aluminum foil and the inner layer can be improved.
JP 2001-6631 A (Claims 1 and 2)

  By the way, the battery case packaging material is required to have the following functions.

1) Excellent resistance to electrolyte solution: Excellent resistance to electrolyte solution even under high temperature conditions, no corrosion of aluminum foil or leakage of electrolyte solution 2) Excellent gas barrier property: Invasion of water vapor from outside What can be prevented (When water vapor enters from the outside, the electrolyte solution is hydrolyzed to produce hydrofluoric acid, and the aluminum foil is corroded by the hydrofluoric acid, which can be sufficiently prevented)
3) The moldability is good: it can be molded into a good state. 4) It has excellent interlayer adhesion strength.

  However, the battery case packaging material according to the prior art has a problem that sufficient adhesive strength cannot be maintained under high temperature conditions although sufficient adhesive strength is obtained by the easy adhesion treatment of the aluminum foil surface. there were. In recent years, lithium-ion secondary batteries are increasingly used in outdoor environments such as laptop computers, video cameras, mobile phones, and electric vehicles. Although there is a strong demand for having an electrolyte resistance sufficient to withstand use, the above-mentioned conventional packaging materials do not have sufficient electrolyte resistance under high temperature conditions. There wasn't. If the electrolytic solution resistance is insufficient, the interlayer adhesive strength between the inner layer and the aluminum foil layer is lowered by the electrolytic solution, a peeling phenomenon occurs between the layers, and water vapor enters the inside of the battery from the outside. Hydrolysis generates hydrofluoric acid, corroding the aluminum foil, and in some cases, the electrolyte leaks from the peeled layers, which may damage the battery function.

  The present invention has been made in view of such a technical background, and has excellent moldability, excellent gas barrier properties, excellent interlayer adhesion strength, and particularly excellent electrolyte resistance even under high temperature conditions. It is an object to provide a packaging material for a component case, a case for an electronic component, and an electronic component using the case.

  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 comprises an aluminum foil having a base film formed on at least one side of the inner layer, and the base film is one or two selected from the group consisting of chitosan and chitosan derivatives. The above chitosans and a metal compound containing one or more metals selected from the group consisting of Ti, Hf, Mo, W, Se, Ce, Fe, Cu, Zn, V and trivalent Cr A packaging material for an electronic component case, which is a film formed by treating the surface of the aluminum foil with a base treatment agent contained therein.

  [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 comprises an aluminum foil having a base film formed on at least one side of the inner layer, and the base film is one or two selected from the group consisting of chitosan and chitosan derivatives. By metal cross-linking reaction between the above chitosans and one or more metals selected from the group consisting of Ti, Hf, Mo, W, Se, Ce, Fe, Cu, Zn, V and trivalent Cr A packaging material for an electronic component case, which is a formed film.

  [3] The packaging material for electronic component cases according to the above item 1 or 2, wherein trivalent Cr is used as the metal.

  [4] The aluminum foil layer and the thermoplastic resin unstretched film layer are dry-laminated via an adhesive layer containing a urethane adhesive layer, an acrylic adhesive layer, or a thermoplastic elastomer. The packaging material for electronic component cases according to any one of the preceding items 1 to 3.

  [5] The packaging material for electronic component cases according to any one of items 1 to 3, wherein the aluminum foil layer and the thermoplastic resin unstretched film layer are heat-laminated via an acid-modified polypropylene layer.

  [6] The aluminum foil layer and the thermoplastic resin unstretched film layer are heat-laminated through a coextruded acid-modified polypropylene layer and an unmodified polypropylene layer, and the acid-modified polypropylene layer is the aluminum foil. 4. The packaging material for an electronic component case according to any one of items 1 to 3, which is disposed in contact with an undercoat of the layer.

  [7] The packaging material for electronic component cases as described in [5] or [6] above, wherein the acid-modified polypropylene is maleic anhydride-modified polypropylene.

  [8] The aforementioned chitosans are one or more chitosans selected from the group consisting of chitosan, carboxymethyl chitosan, cationized chitosan, hydroxyalkyl chitosan, and salts thereof with these acids. The packaging material for electronic component cases according to any one of the above.

  [9] The electronic component case packaging material according to any one of [1] to [8], wherein the heat resistant resin stretched film layer is formed of a stretched film made of polyamide or polyester.

  [10] The unstretched thermoplastic resin film layer is an unstretched film composed of at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. 10. The packaging material for electronic component cases as set forth in any one of 1 to 9 above.

  [11] An electronic component case formed into a required shape by deep drawing or stretch forming the electronic component case packaging material according to any one of items 1 to 10.

  [12] An electronic component main body and a case surrounding the electronic component main body, wherein the case is formed by deep drawing or stretch-molding the electronic component case packaging material according to any one of items 1 to 10 above. An electronic component characterized by being formed by

  In the invention of [1], the base film formed by treating with a base treating agent containing chitosans and the metal compound containing the specific metal is at least one side of the aluminum foil (one side on the inner layer side). ), It is possible to effectively prevent the penetration of the electrolytic solution and the like by this base film, and the resistance to the electrolytic solution as a packaging material can be improved. In particular, the electrolyte solution resistance is always excellent under high temperature conditions. Therefore, the packaging material for an electronic component case of the present invention exhibits sufficiently stable electrolytic solution resistance even when used in a high temperature environment. Moreover, this packaging material for electronic component cases has good moldability, excellent gas barrier properties, and excellent interlayer adhesion strength.

  In the invention of [1], it is more preferable that the base treatment agent contains an organic compound having at least one carboxyl group in the molecule. In the invention [1], it is preferable that the undercoat is formed on both surfaces of the aluminum foil.

  In the invention of [2], since the base film formed by the cross-linking reaction between chitosans and the specific metal is provided on at least one surface (one surface on the inner layer side) of the aluminum foil, the base film is electrolyzed. Penetration of liquid or the like can be effectively prevented, and resistance to electrolytic solution as a packaging material can be improved. In particular, the electrolyte solution resistance is extremely excellent under high temperature conditions. Therefore, the packaging material for an electronic component case of the present invention exhibits sufficiently stable electrolytic solution resistance even when used in a high temperature environment. Moreover, this packaging material for electronic component cases has good moldability, excellent gas barrier properties, and excellent interlayer adhesion strength. In the invention [2], it is preferable that the undercoat is formed on both surfaces of the aluminum foil.

  In the invention of [3], since trivalent Cr is used as the metal, the resistance to electrolytic solution under high temperature conditions can be further improved, and the moldability can also be improved.

  In the invention of [4], the aluminum foil layer and the thermoplastic resin unstretched film layer are dry laminated through a urethane adhesive layer, an acrylic adhesive layer, or an adhesive layer containing a thermoplastic elastomer. Therefore, this packaging material has a low moisture permeability. Accordingly, it is possible to sufficiently prevent the water vapor from the outside from entering the inside of the battery to hydrolyze the electrolyte and generate hydrofluoric acid to corrode the aluminum foil.

  In the invention of [5], since the aluminum foil layer and the thermoplastic resin unstretched film layer are heat-laminated via an acid-modified polypropylene layer, the resistance to electrolytic solution under high temperature conditions can be further improved. it can.

  In the invention of [6], the aluminum foil layer and the thermoplastic resin unstretched film layer are heat-laminated through the coextruded acid-modified polypropylene layer and the unmodified polypropylene layer, and the acid-modified polypropylene layer is an aluminum foil. Since it is disposed in contact with the underlying coating of the layer, the resistance to electrolytic solution under high temperature conditions can be further improved. And since the unmodified polypropylene layer is laminated and integrated, good moldability can be ensured.

  In the invention of [7], maleic anhydride-modified polypropylene is used as the acid-modified polypropylene, so that the resistance to electrolytic solution under high temperature conditions can be further improved.

  In the invention of [8], the strength of the undercoat can be improved.

  In the invention of [9], since the heat resistant resin stretched film layer (outer layer) is composed of a stretched film made of polyamide or polyester, necking of the aluminum foil at the time of molding can be effectively prevented, It becomes possible to obtain a molded body (case) having a deep and sharp shape.

  In the invention of [10], the unstretched thermoplastic resin film layer (inner layer) is at least one thermoplastic selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. Since it is comprised with the unstretched film which consists of resin, heat-sealing property can fully be provided to a packaging material.

  In the invention of [11], the electronic component case exhibits sufficiently stable electrolytic solution resistance even when used in a high-temperature environment, has good moldability, and excellent gas barrier properties. Also, the interlayer adhesion strength is excellent.

  In the invention of [12], even when used in a high temperature environment, it exhibits sufficiently stable electrolytic solution resistance, good moldability, excellent gas barrier properties, and interlayer adhesion strength. An electronic component having an excellent case for electronic components is provided.

  One 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) is a two-part solution (on the base film (11)) on the upper surface of the aluminum foil layer (4) formed with the base films (11) and (12) on both sides of the aluminum foil (10). The stretched heat-resistant resin film layer (outer layer) (2) is laminated and integrated through the first adhesive layer (5) made of reactive adhesive, and is formed on the lower surface of the aluminum foil layer (4) (underlayer Under the coating (12), the thermoplastic resin unstretched film layer (inner layer) (3) is laminated and integrated through a second adhesive layer (6) made of a two-component reactive adhesive. .

  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, the role of preventing breakage due to necking of the aluminum foil during molding. It is what you bear. 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 9 to 50 μm. If it is less than 9 μm, the stretched film is insufficiently stretched when sharp molding is performed, and it is easy to cause necking of the aluminum foil, which is not preferable because it tends to cause molding defects. Further, if it exceeds 50 μm, no further improvement in moldability can be expected, and the amount of resin used is merely increased.

  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 9 to 50 μm. If it is less than 9 μm, the thickness becomes too thin and there is a concern that pinholes are generated, which is not preferable. Moreover, even if it exceeds 50 μm, it is not preferable because it only increases the amount of resin used. Especially, it is especially preferable that the thickness of the thermoplastic resin unstretched film layer (3) is set to 20 to 40 μm.

  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, and a base coating (11) (12) is formed on both sides of the aluminum foil (10). It consists of made.

  As the aluminum foil (10), an O material (soft material) having a thickness of 10 to 100 μm made of pure aluminum or aluminum-iron alloy is preferably used. The thickness of the aluminum foil (10) is particularly preferably set to 30 to 50 μm.

  The undercoat (11) (12) comprises one or more chitosans selected from the group consisting of chitosan and chitosan derivatives, and Ti, Hf, Mo, W, Se, Ce, Fe, Cu, Zn A film formed by treating both surfaces of the aluminum foil with a base treatment agent containing a metal compound containing one or more metals selected from the group consisting of V and trivalent Cr is there. By such treatment, the chitosans and one or more metals selected from the group consisting of Ti, Hf, Mo, W, Se, Ce, Fe, Cu, Zn, V and trivalent Cr Undercoat films (11) and (12) formed by the metal cross-linking reaction are formed on both front and back surfaces of the aluminum foil (10). In addition, in this embodiment, although the structure by which base film (11) (12) was formed on both surfaces of the aluminum foil (10) is employ | adopted, the one side by the side of the said inner layer (3) of aluminum foil (10) Alternatively, a configuration in which a base coating (12) is formed (on the inner surface side) may be employed.

  The chitosans will be described. The chitosan can be obtained, for example, by deacetylating 60 to 100 mol% of natural polymeric chitin extracted from crustaceans such as crabs and shrimps. The chitosan derivative is a compound obtained by, for example, carboxylation, glycolation, tosylation, sulfation, phosphorylation, etherification, alkylation, etc. with respect to the hydroxyl group or / and amino group present in chitosan. . Among these, as the chitosans, it is preferable to use one or more chitosans selected from the group consisting of chitosan, carboxymethyl chitosan, cationized chitosan, hydroxyalkyl chitosan, and salts with these acids.

  The metal compound containing one or more metals selected from the group consisting of Ti, Hf, Mo, W, Se, Ce, Fe, Cu, Zn, V, and trivalent Cr is particularly limited. For example, metal oxides, hydroxides, complex compounds, organic acid salts, and inorganic acid salts of these metals can be used.

  Among these, as the metal compound, it is preferable to use a metal compound containing trivalent Cr. In this case, the resistance to electrolytic solution under high temperature conditions can be further improved, and the moldability is also improved. Can do. Examples of the metal compound containing trivalent Cr include chromium sulfate, chromium nitrate, chromium fluoride, chromium oxalate, and chromium acetate.

  In addition to the chitosans and the metal compound, the surface treatment agent preferably further contains an organic compound having at least one carboxyl group in the molecule. By including such an organic compound, the solubility of chitosans can be improved, and the degree of metal crosslinking of chitosans can be improved (high molecular weight).

  The organic compound having at least one carboxyl group in the molecule is not particularly limited. For example, acetic acid, succinic acid, malonic acid, malic acid, tartaric acid, mellitic acid, adipic acid, succinic acid, maleic acid, phthalic acid, sebatin Examples include acid, citric acid, butanetricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, ethylenediaminetetracarboxylic acid, trimellitic acid and the like.

  The surface treatment agent may further contain a pH adjuster, various additives, and the like as necessary.

  The concentration of chitosans in the surface treatment agent is preferably set in the range of 0.001 to 10% by mass, and more preferably in the range of 0.1 to 5% by mass. Moreover, it is preferable to set the density | concentration of the metal compound in the said surface treatment agent in the range of 0.001-10 mass%, and it is more preferable to set in the range of 0.1-5 mass% especially. Moreover, about the mixing ratio of both in the said surface treating agent, it is preferable to set it as 1-1000 mass parts of said metal compounds with respect to 100 mass parts of said chitosans, and it is more preferable to set it as 10-100 mass parts especially.

  As a processing method at the time of processing aluminum foil (10) with the above-mentioned surface treating agent, after applying a surface treating agent on the surface of aluminum foil (10), it is the application processing which heat-drys or dries, or under the surface treating agent. Although the chemical conversion treatment etc. which wash the surface with water after making these components chemically react with the surface of aluminum foil (10), and dry are mentioned, it is not limited to these in particular. Examples of the coating method include a roll coating method, a spin coating method, a dipping method, and a spray method.

Thus, the dry adhesion amount of the chitosans to the aluminum foil (10) surface is in the range of 1 to 500 mg / m ^{2 in} terms of chitosan, and the dry adhesion amount of the metal compound to the aluminum foil (10) surface is It is preferably in the range of 1 to 500 mg / m ^{2 in} terms of metal. Especially, it is preferable that the adhesion amount at the time of drying with respect to the aluminum foil (10) surface of the said chitosan is 10-100 mg / m < ² > in conversion of chitosan. Moreover, it is especially preferable that the adhesion amount at the time of drying with respect to the aluminum foil (10) surface of the said metal compound is the range of 5-50 mg / m < ² > in conversion of a metal.

  The first adhesive layer (5) is not particularly limited, but is preferably a urethane-based adhesive layer formed of a urethane-based two-component reaction-type adhesive, whereby deep drawing or overhanging is performed. It becomes possible to perform sufficiently sharp molding.

  Although the said 2nd adhesive bond layer (6) is not specifically limited, The urethane type adhesive layer, acrylic adhesive layer, or thermoplastic elastomer formed with the two-component reaction type adhesive agent is contained. An adhesive layer is preferred. In the case of an acrylic adhesive layer or an adhesive layer containing a thermoplastic elastomer, the moisture permeability of the packaging material (1) becomes very small, so that water vapor from the outside enters the battery. Thus, there is an advantage that it is possible to sufficiently prevent the electrolyte from being hydrolyzed to generate hydrofluoric acid and corroding the aluminum foil (10).

  Alternatively, a configuration as shown in FIG. 2 may be employed instead of the second adhesive layer. That is, adopting a configuration comprising two layers of an acid-modified polypropylene layer (21) and an unmodified polypropylene layer (22) by coextrusion, which are disposed in contact with the base film (12) of the aluminum foil layer (4). In this case, the electrolytic solution resistance can be further improved. Such a laminate is manufactured, for example, by a method as shown in FIG. That is, while coextruding the acid-modified polypropylene layer (21) and the unmodified polypropylene layer (22), while feeding the aluminum foil layer (4) from the left side of the drawing, the thermoplastic resin unstretched film (3) from the right side of the drawing. Then, between these (4) and (3), the acid-modified polypropylene layer (21) and the unmodified polypropylene layer (22) are sandwiched by a pair of heat and pressure rolls and heat laminated.

  The acid-modified polypropylene is not particularly limited, but maleic anhydride-modified polypropylene is preferably used.

  An electronic component case can be obtained by deep drawing or stretch molding the electronic component case packaging material (1) of the present invention. In addition, in the conventional packaging materials for electronic component cases, since the electrolyte solution resistance of the undercoat is insufficient, the interlayer adhesive strength between the inner layer and the aluminum foil layer is lowered by the electrolyte, and the peeling phenomenon occurs between the layers. Water vapor enters the inside of the battery from the outside and the electrolytic solution is hydrolyzed, hydrofluoric acid is generated, corroding the aluminum foil, and in some cases, the electrolytic solution leaks from the peeled layer, damaging the battery function. However, the case for electronic parts of the present invention exhibits sufficiently stable electrolytic solution resistance even when used in a high temperature environment, and has good moldability and gas barrier properties. In addition, the interlayer adhesion strength is also excellent. It is also possible to form a deep and sharp shape.

  Thus, the electronic component of the present invention can be obtained by enclosing an electronic component body such as a battery such as a lithium ion secondary battery in the case for the electronic component.

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

<Example 1>
The liquid which mixed 500 mass parts of water, 10 mass parts of glycerylated chitosan, and 10 mass parts of 1,2,3,4-butanetetracarboxylic acid was stirred for 4 hours, and the glycerylated chitosan was fully dissolved. 5 parts by mass of chromium fluoride (trivalent Cr) was added to the resulting solution to obtain a base treatment agent. Next, after applying the surface treatment agent on both sides of a 40 μm aluminum foil with a roll coater, heating and drying at 200 ° C. for 30 seconds to form a base film (11) (12) on both sides of the aluminum foil (10). Caulking (an aluminum foil layer (4) was obtained).

  Next, a urethane two-component reactive adhesive (5) is applied to the surface of the obtained undercoat (11) with a gravure roll, dried to some extent by heating, and then the adhesive surface is made of nylon. A 25 μm stretched film (2) was laminated.

  Next, as shown in FIG. 3, a maleic anhydride-modified polypropylene layer (21) having a thickness of 3 μm and an unmodified polypropylene layer (22) having a thickness of 12 μm are coextruded. While supplying the bonded aluminum foil layer (4), an unstretched film (3) having a thickness of 30 μm made of polypropylene was supplied from the right side of the drawing and coextruded between these (4) and (3). The maleic anhydride-modified polypropylene layer (21) and the unmodified polypropylene layer (22) were sandwiched between a pair of heat and pressure rolls and heat laminated.

  Next, after applying urethane resin adhesive (5) to the surface of the base film (11) of the obtained laminated film with a gravure roll and drying to some extent by heating, the adhesive surface is made of nylon. A 25 μm stretched film (2) was laminated to obtain a battery case packaging material having a total thickness of 113 μm.

<Example 2>
The liquid obtained by mixing 500 parts by mass of water, 15 parts by mass of cationized chitosan and 15 parts by mass of 1,2,3,4-butanetetracarboxylic acid was stirred for 4 hours to sufficiently dissolve the cationized chitosan. 8 parts by mass of chromium fluoride (trivalent Cr) was added to the resulting solution to obtain a base treatment agent X. A battery case packaging material was obtained in the same manner as in Example 1 except that the surface treatment agent X was used as the surface treatment agent.

<Example 3>
The mixture of 500 parts by weight of water, 20 parts by weight of carboxymethyl chitosan, and 20 parts by weight of 1,2,3,4-butanetetracarboxylic acid was stirred for 4 hours to sufficiently dissolve carboxymethyl chitosan. 10 parts by mass of chromium fluoride (trivalent Cr) was added to the resulting solution to obtain a base treatment agent Y. A battery case packaging material was obtained in the same manner as in Example 1 except that the base treatment agent Y was used as the base treatment agent.

<Example 4>
Chitosan was fully dissolved by stirring the liquid which mixed 500 mass parts of water, 15 mass parts of chitosan, and 15 mass parts of 1,2,3,4-butanetetracarboxylic acid for 4 hours. 8 parts by mass of chromium fluoride (trivalent Cr) was added to the resulting solution to obtain a base treatment agent Z. A battery case packaging material was obtained in the same manner as in Example 1 except that the above-mentioned base treatment agent Z was used as the base treatment agent.

<Example 5>
A battery case packaging material was obtained in the same manner as in Example 1 except that 5 parts by mass of ammonium molybdate was used instead of 5 parts by mass of chromium fluoride (trivalent Cr) when preparing the base treatment agent. It was.

<Example 6>
A battery case packaging material was obtained in the same manner as in Example 1 except that 5 parts by mass of ammonium titanium fluoride was used instead of 5 parts by mass of chromium fluoride (trivalent Cr) when preparing the base treatment agent. It was.

<Example 7>
When preparing the base treatment agent, 10 parts by mass of chitosan was used instead of 10 parts by mass of glycerylated chitosan, and 5 parts by mass of ammonium titanium fluoride was used instead of 5 parts by mass of chromium fluoride (trivalent Cr). In the same manner as in Example 1, a battery case packaging material was obtained.

<Example 8>
A battery case packaging material was obtained in the same manner as in Example 1 except that a 25 μm thick stretched film made of polyester was used instead of the 25 μm thick stretched film made of nylon.

< Reference Example 1 >
The liquid which mixed 500 mass parts of water, 20 mass parts of glycerylated chitosan, and 20 mass parts of 1,2,3,4-butanetetracarboxylic acid was stirred for 4 hours, and glycerylated chitosan was fully dissolved. 10 parts by mass of chromium fluoride (trivalent Cr) was added to the resulting solution to obtain a base treatment agent. Next, the surface treatment agent was applied to both surfaces of a 40 μm aluminum foil with a roll coater, and then heated and dried at 200 ° C. for 30 seconds to form a ground film on both surfaces of the aluminum foil (an aluminum foil layer was obtained). ).

  Next, a urethane two-component reactive adhesive (5) is applied to the surface of the base film (11) of the obtained aluminum foil layer with a gravure roll, dried to some extent by heating, and then the nylon is applied to the adhesive surface. A stretched film (2) having a thickness of 25 μm was dry-laminated.

  Further, a urethane two-component reactive adhesive (6) is applied to the surface of the base film (12) of the obtained laminated film with a gravure roll, dried to some extent by heating, and then the adhesive surface is made of polypropylene. The unstretched film (3) having a thickness of 30 μm was dry-laminated to obtain a battery case packaging material having a total thickness of 101 μm.

< Reference Example 2 >
The liquid which mixed 500 mass parts of water, 10 mass parts of glycerylated chitosan, and 10 mass parts of 1,2,3,4-butanetetracarboxylic acid was stirred for 4 hours, and the glycerylated chitosan was fully dissolved. 5 parts by mass of chromium fluoride (trivalent Cr) was added to the resulting solution to obtain a base treatment agent. Next, the surface treatment agent was applied to both surfaces of a 40 μm aluminum foil with a roll coater, and then heated and dried at 200 ° C. for 30 seconds to form a ground film on both surfaces of the aluminum foil (an aluminum foil layer was obtained). ).

  Next, a urethane two-component reactive adhesive (5) is applied to the surface of the base film (11) of the obtained aluminum foil layer with a gravure roll, dried to some extent by heating, and then the nylon is applied to the adhesive surface. A stretched film (2) having a thickness of 25 μm was dry-laminated.

  Further, an acrylic two-component reactive adhesive (6) is applied to the surface of the base film (12) of the obtained laminated film with a gravure roll, dried to some extent by heating, and then the adhesive surface is made of polypropylene. The unstretched film (3) having a thickness of 30 μm was dry-laminated to obtain a battery case packaging material having a total thickness of 100 μm.

< Reference Example 3 >
A battery case packaging material was obtained in the same manner as in Reference Example 2 except that a two-component reactive adhesive (6) containing a thermoplastic elastomer was used instead of the acrylic two-component reactive adhesive (6). It was.

<Comparative Example 1>
A battery case packaging material was obtained in the same manner as in Example 1 except that an aluminum foil (40 μm) that had not been subjected to any ground treatment was used as the aluminum foil layer.

<Comparative example 2>
An aluminum foil layer obtained by applying an aqueous treatment agent (acrylic resin content: 5 mass%, zirconium fluoride: 5 mass%) on both sides of a 40 μm aluminum foil and then applying a ground treatment to both sides of the aluminum foil by drying. A battery case packaging material was obtained in the same manner as in Example 1 except that the above was used.

<Comparative Example 3>
Example 1 with the exception that a 10% by weight chromium phosphate aqueous solution was applied to both sides of a 40 μm aluminum foil and then dried to provide a base treatment on both sides of the aluminum foil as the aluminum foil layer. Similarly, a packaging material for a battery case was obtained.

  Performance evaluation was performed based on the following evaluation method with respect to each battery case packaging material obtained as described above.

<Adhesive strength evaluation method>
It peeled in the interface of an unstretched polypropylene film layer and an aluminum foil layer, and measured the adhesive strength between both. “◎” if the adhesive strength (laminate strength) is 15 N / 15 mm or more, “◯” if it is 10 N / 15 mm or more and less than 15 N / 15 mm, “△” if it is 5 N / 15 mm or more and less than 10 N / 15 mm. The thing of less than 5N / 15mm was set to "x".

<Formability evaluation method>
The packaging material was made into a blank shape of 110 × 180 mm, deep drawing one-step molding was performed with a straight mold free of molding height, and the moldability was evaluated based on the molding height of each packaging material. Molding heights of 5 mm or more were designated as “」 ”, 3 mm or more and less than 5 mm as“ ◯ ”, 2 mm or more and less than 3 mm as“ Δ ”, and less than 2 mm as“ x ”. The punch shape of the mold used was 60 mm long side, 45 mm short side, corner R: 1-2 mm, punch shoulder R: 1-2 mm, and die shoulder R: 0.5 mm.

<Evaluation of presence / absence of peeling of outer surface>
The molded product obtained by the deep drawing single-stage molding was allowed to stand at 80 ° C. for 3 hours in a dryer, and then visually observed for delamination (peeling) on the outer surface layer. Even when the molding height is 5 mm or more, “◎” indicates that no peeling occurred, “◯” indicates that peeling occurred when the molding height was 5 mm or more, and peeling occurred when the molding height was 3 mm or more. The case where “Δ” was given and the case where peeling occurred even when the molding height was less than 3 mm was taken as “x”.

<Evaluation of electrolytic solution resistance under high temperature conditions>
An electrolytic solution (dimethyl carbonate + ethyl carbonate (DMC: EC = 1: 1) + lithium salt) was injected into a molded article (container) obtained by the above-described deep drawing one-stage molding, and the container was inverted after heat sealing, In this state, it was stored at 85 ° C. for 1 month. Thereafter, the presence or absence of leakage of the electrolytic solution was examined. If there was no leakage, “◎” was assigned, and if there was leakage, “x” was assigned. In addition, the inner layer of the packaging material after being stored at 85 ° C. for 1 month was peeled off, and the presence or absence of discoloration and corrosion on the surface of the aluminum foil was examined. In the examples, “◯” indicates that the color changed, “Δ” indicates that the color changed to some extent, and “x” indicates that at least point-like corrosion was observed.

  Furthermore, each packaging material was immersed in an electrolytic solution (dimethyl carbonate + ethyl carbonate (DMC: EC = 1: 1) + lithium salt), and the packaging material was stored for 1 month at 85 ° C. in this immersion state. It peeled at the interface of a polypropylene film layer and an aluminum foil layer, and measured the adhesive strength between both. “◎” when the measured adhesive strength was almost unchanged with respect to the initial adhesive strength and the retention rate was 95% or more, and “◎” when the retention rate was 60% or more and less than 95% with respect to the initial adhesive strength. “◯”, “△” indicates that the retention rate was 30% or more and less than 60% with respect to the initial adhesive strength, and “X” indicates that the retention rate was less than 30% with respect to the initial adhesive strength.

The initial laminate strengths of the Examples and Comparative Examples in Table 2 are all good, but when looking at the laminate strength after immersion in the 85 ° C electrolyte solution, Examples 1 to 8 and Reference Examples 1 to 3 of the present invention While all the battery case packaging materials are able to maintain good laminate strength, the packaging strengths of Comparative Examples 1 to 3 are greatly reduced. Therefore, the battery case packaging material of the present invention is resistant to It turns out that it is very excellent in electrolyte solution property.

  Moreover, the packaging materials for battery cases of Comparative Examples 1 and 2 were inferior in corrosion resistance after immersion in the electrolyte, and the packaging material for battery cases in Comparative Example 3 was inferior in moldability.

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 other embodiment of the packaging material for electronic component cases which concerns on this invention. It is a figure which shows an example of the manufacturing method of the packaging material for electronic component cases which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Packaging material for electronic component cases 2 ... Outer layer 3 ... Inner layer 4 ... Aluminum foil layer 5 ... 1st adhesive layer 6 ... 2nd adhesive layer 10 ... Aluminum foil 11 ... Base film 12 ... Base film 21 ... Acid Modified polypropylene layer 22 ... Unmodified polypropylene layer

Claims (8)

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 consists of an aluminum foil having a base film formed on at least one side of the inner layer side,
The undercoat is composed of one or more chitosans selected from the group consisting of chitosan and chitosan derivatives, Ti, Hf, Mo, W, Se, Ce, Fe, Cu, Zn, V, and trivalent Cr. A film formed by treating the surface of the aluminum foil with a base treatment agent containing a metal compound containing one or more metals selected from the group consisting of:
The aluminum foil layer and the thermoplastic resin unstretched film layer are heat-laminated through a coextruded acid-modified polypropylene layer and an unmodified polypropylene layer, and the acid-modified polypropylene layer is a base of the aluminum foil layer. A packaging material for an electronic component case, which is disposed in contact with a film. The packaging material for an electronic component case according to claim 1 , wherein the acid-modified polypropylene is maleic anhydride-modified polypropylene. Electronic component case material according to claim 1 or 2 trivalent Cr is used as the metal. The chitosans, chitosan, carboxymethyl chitosan, any claim 1-3 is cationized chitosan, hydroxyalkyl chitosan and one or more chitosans selected from the group consisting of salts of these acids A packaging material for an electronic component case according to claim 1. The electronic component case packaging material according to any one of claims 1 to 4 , wherein the heat-resistant resin stretched film layer is composed of a stretched film made of polyamide or polyester. The thermoplastic resin unstretched film layer is composed of an unstretched film composed of at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. The packaging material for electronic component cases according to any one of claims 1 to 5 . An electronic component case formed into a required shape by deep drawing or stretch forming the packaging material for an electronic component case according to any one of claims 1 to 6 . An electronic component main body and a case surrounding the electronic component main body, wherein the case is formed by deep drawing or stretch-molding the electronic component case packaging material according to any one of claims 1 to 6. An electronic component that is formed.

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