JP2015217577A - Packaging material for molding and molded case - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging material for molding that causes no peeling of a heat-resistant resin layer during molding and sealing or when used under relatively severe environment of high temperature and high humidity or the like.SOLUTION: A packaging material 1 for molding includes a heat-resistant resin layer 2 as an outer layer, a thermoplastic resin layer 3 as an inner layer, a metal foil layer 4 disposed between both of the layers, and a colored ink layer 10 disposed between the metal foil layer 4 and the heat-resistant resin layer 2. The colored ink layer 10 comprises a coloring ink composition including: a two-liquid curable type polyester urethane resin binder composed of a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent; and a coloring pigment including an inorganic pigment. The polyester resin has a Mn of 8,000 to 25,000, a Mw of 15,000 to 50,000, and a ratio (Mw/Mn) of 1.3 to 2.5, and 50 mol% or more of the polyfunctional isocyanate compound is an aromatic polyfunctional isocyanate compound.

Description

  The present invention is suitably used as a case for, for example, notebook computers, mobile phones, in-vehicle, stationary secondary batteries (lithium ion secondary batteries), and also suitable as food packaging materials and pharmaceutical packaging materials. The present invention relates to a molding packaging material and a molding case used in the above.

  Batteries such as lithium ion secondary batteries are increasingly required to be colored in order to unify the appearance and color of devices such as electrical devices to be mounted. For example, in order to give a profound feeling and a high-class feeling, the device is often black, and in this case, the battery is also often black.

  This type of battery consists of a battery body packaged in a packaging material (molded case), and the packaging material is generally a laminate in which a base resin layer is laminated on both sides of a metal foil. Thus, to color the battery, the base resin layer used in the battery packaging material is colored, a colored printing layer is provided under the base resin layer, the base resin layer and the metal foil There are means such as coloring the adhesive layer between them, and coloring the adhesive layer between these layers when the base resin layer is composed of a plurality of layers.

  Conventionally, a battery packaging material having a colored layer has a structure in which a base material layer, an adhesive layer, a metal foil layer, and a heat-adhesive resin layer are laminated in this order, and the base material layer, the adhesive layer, and the metal One of the foil layers includes a pearl pigment or fluorescent pigment as an identification mark (see Patent Document 1), a base material layer, an adhesive layer, a metal foil layer, and a thermal adhesive resin layer. A structure in which a pigment as an identification mark is added to any one of a base material layer, an adhesive layer, and a metal foil layer (see Patent Document 2) is known.

  Also, a battery exterior material (see Patent Document 3) having a black body material layer such as a carbon material between a metal foil layer and an outer layer film is known for improving the heat dissipation of the battery.

International Publication No. 2011/016506 Pamphlet JP 2011-045463 A JP 2011-0965552 A

  Generally, when a film material or a sheet material is colored black, it is common to provide a printing layer with a printing ink containing an inorganic pigment such as carbon black.

  However, when a black printing layer containing carbon black as a pigment is provided on the inner surface of the outer resin layer constituting the battery packaging material in order to color the battery in black, there are the following problems.

  That is, when the black packaging material is molded into a container (case) shape by deep drawing molding or stretch molding, there is a problem that the outer resin layer peels from the black printed layer of the packaging material.

  Such exfoliation of the outer resin layer occurs when the black packaging material is sealed after enclosing the electrode or electrolyte, or when the battery packaged with the black packaging material is used in a slightly harsh environment such as high temperature and high humidity. Also occurs.

  The above-mentioned problems occur not only in black packaging materials using carbon black but also in colored packaging materials in which various colors are similarly colored with other inorganic pigments.

  The present invention has been made in view of such a technical background, and the heat-resistant resin layer is formed at the time of molding and sealing, and even when used in a slightly severe environment such as high temperature and high humidity. It aims at providing the packaging material for shaping | molding which does not peel.

  In order to achieve the above object, the present invention provides the following means.

[1] A heat resistant resin layer as an outer layer, a thermoplastic resin layer as an inner layer, a metal foil layer disposed between both layers, and between the metal foil layer and the heat resistant resin layer A packaging material for molding including an arranged colored ink layer,
The colored ink layer is
A two-component curable polyester urethane resin binder comprising a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent;
A colored ink composition comprising an inorganic pigment and a colored pigment,
The polyester resin as the main agent has a number average molecular weight (Mn) of 8000 to 25000, a mass average molecular weight (Mw) of 15,000 to 50000, and a ratio (Mw / Mn) of 1.3 to 2.5. And
A molding packaging material, wherein 50 mol% or more of the polyfunctional isocyanate compound as the curing agent is an aromatic polyfunctional isocyanate compound.

  [2] The molding packaging material according to item 1, wherein in the colored ink layer, the ratio of the content mass of the color pigment to the total mass of the polyester resin as the main agent and the color pigment is 5% by mass to 60% by mass.

  [3] The molding packaging material according to item 1 or 2, wherein 50 mol% or more of the color pigment is composed of the inorganic pigment.

  [4] The two-component curable polyester urethane resin binder may have a Young's modulus of 70 MPa to 400 MPa according to a tensile test (JIS K7162) of a cured film after the main agent and the curing agent have reacted. The molding packaging material according to claim 1.

  [5] The molding packaging material according to any one of items 1 to 4, wherein a chemical conversion film is formed on at least one surface of the metal foil layer.

  [6] A molded case formed by deep-drawing or stretch-molding the molding packaging material according to any one of items 1 to 5.

  [7] The molded case according to item 6 used as a battery case.

  In the invention of [1], since the colored ink layer is provided between the metal foil layer and the heat-resistant resin layer, the outer surface side of the molding packaging material is colored. The colored ink layer comprises a colored ink composition comprising a two-component curable polyester urethane resin binder comprising a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent, and a colored pigment containing an inorganic pigment, The polyester resin as the main agent has a number average molecular weight (Mn) of 8000 to 25000, a mass average molecular weight (Mw) of 15,000 to 50000, and a ratio thereof (Mw / Mn) of 1.3 to 2.5. Therefore, strength and elongation suitable for a colored ink layer (colored ink coating film) and excellent heat resistance can be obtained. Furthermore, since 50 mol% or more of the polyfunctional isocyanate compound is composed of an aromatic polyfunctional isocyanate compound, the adhesive strength after curing can be increased. Therefore, when the packaging material is molded by deep drawing or stretch molding, the heat resistant resin layer does not peel from the colored ink layer when the packaging material is sealed for sealing. Further, even when used in a slightly severe environment such as high temperature and high humidity, the heat resistant resin layer does not peel from the colored ink layer.

  In the invention of [2], in the colored ink layer, the content ratio of the color pigment to the total mass of the polyester urethane resin binder and the color pigment is 5% by mass to 60% by mass, and the metal foil layer is 5% by mass or more. The effect of concealing is sufficiently obtained, the metallic luster is not visually recognized, and a solid feeling and a high-class feeling can be sufficiently imparted, and the colored ink layer adheres to the heat-resistant resin layer by being 60% by mass or less. Enough power can be secured.

  In the invention of [3], since 50% by mass or more of the color pigment is composed of an inorganic pigment, a sufficient hiding power for hiding the metal foil layer can be obtained. A colored ink layer having a specific color tone that can be imparted to the ink can be formed. Conventionally, in general, when the content of the inorganic pigment in the colored pigment is designed to be 50% by mass or more in order to improve the hiding power, there is a problem that the adhesion of the colored ink layer is lowered. In the present invention, “The polyester resin as the main agent has a number average molecular weight (Mn) of 8000 to 25000, a mass average molecular weight (Mw) of 15,000 to 50000, and a ratio (Mw / Mn) of 1.3 to 2. 5 and 50 mol% or more of the polyfunctional isocyanate compound is composed of an aromatic polyfunctional isocyanate compound ”is adopted, so that 50 mass% or more of the colored pigment is an inorganic pigment. Even when the configured configuration is adopted, sufficient adhesion as a colored ink layer can be ensured.

  In the invention of [4], the above effect (the effect that the heat-resistant resin layer does not peel from the colored ink layer at the time of molding and sealing, or when used in a slightly severe environment such as high temperature and high humidity). ) Is particularly excellent.

  In the invention of [5], since the chemical conversion film is formed on at least one surface of the metal foil layer, a molding packaging material that can sufficiently prevent corrosion of the metal foil and has excellent corrosion resistance is provided.

  In the invention of [6], there is a molded case in which the heat-resistant resin layer does not peel from the colored ink layer even when used in a slightly harsh environment such as high temperature and high humidity as well as during sealing. Provided.

  In the invention of [7], there is a battery case in which the heat-resistant resin layer does not peel from the colored ink layer even when used in a slightly harsh environment such as high temperature and high humidity as well as at the time of sealing. Provided.

It is sectional drawing which shows one Embodiment of the packaging material for shaping | molding which concerns on this invention. It is sectional drawing which shows other embodiment of the packaging material for shaping | molding which concerns on this invention. It is a SS curve figure of the cured film of a two-component curing type polyester urethane resin binder.

  One embodiment of the packaging material 1 for molding according to the present invention is shown in FIG. The molding packaging material 1 is used as a packaging material for a lithium ion secondary battery case. That is, the molding packaging material 1 is used as a secondary battery case after being subjected to molding such as deep drawing.

  The molding packaging material 1 includes a heat-resistant resin layer (outer layer) 2 laminated and integrated on the upper surface of the metal foil layer 4 via a first adhesive layer 5, and a lower surface of the metal foil layer 4. (2) The thermoplastic resin layer (inner layer) 3 is laminated and integrated through an adhesive layer 6. Moreover, the colored ink layer 10 is arrange | positioned between the said metal foil layer 4 and the said heat resistant resin layer 2 (refer FIG. 1). In the present embodiment, the colored ink layer 10 is laminated on the upper surface of the metal foil layer 4 via the first adhesive layer 5, and the heat-resistant resin layer 2 is laminated on the upper surface of the colored ink layer 10. (See FIG. 1). In the present embodiment, the colored ink layer 10 is laminated on the lower surface of the heat resistant resin layer 2 by printing.

  Next, each constituent layer in the present invention will be described in detail.

(Heat resistant resin layer)
Although it does not specifically limit as the said heat resistant resin layer (outer layer) 2, For example, a polyamide film, a polyester film, etc. are mentioned, These stretched films are used preferably. Among them, the heat-resistant resin layer 2 includes a biaxially stretched polyamide film, a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polyethylene terephthalate (PET) film, or a biaxially stretched polyethylene in terms of moldability and strength. It is particularly preferable to use a naphthalate (PEN) film. The polyamide film is not particularly limited, and examples thereof include 6 nylon film, 6,6 nylon film, and MXD nylon film. The heat resistant resin layer 2 may be formed as a single layer, or may be formed as a multilayer composed of, for example, a PET film / polyamide film.

  The heat-resistant resin layer 2 preferably has a thickness of 9 μm to 50 μm. When using a polyester film, the thickness is preferably 9 μm to 50 μm, and when using a polyamide film, the thickness is preferably 10 μm to 50 μm. It is possible to secure sufficient strength as a packaging material by setting it above the preferred lower limit value, and to improve the formability by reducing the stress at the time of stretch molding or drawing by setting the preferred lower limit value or less. Can do.

(Thermoplastic resin layer)
The thermoplastic resin layer (inner layer) 3 has excellent chemical resistance against highly corrosive electrolytes used in lithium ion secondary batteries and the like, and imparts heat sealability to the packaging material. To play a role.

  Although it does not specifically limit as said thermoplastic resin layer 3, It is preferable that it is a thermoplastic resin unstretched film layer. The thermoplastic resin unstretched film layer is not particularly limited, but in terms of chemical resistance and heat sealability, the group consisting of polyethylene, polypropylene, olefin copolymers, acid-modified products thereof, and ionomers. It is preferably composed of an unstretched film made of at least one selected thermoplastic resin.

  The thickness of the thermoplastic resin layer 3 is preferably set to 20 μm 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 thermoplastic resin layer 3 is set to 30 μm to 50 μm. The thermoplastic resin layer 3 may be a single layer or a multilayer. Examples of the thermoplastic resin layer 3 having a multilayer structure include a three-layer film in which random polypropylene films are laminated on both sides of a block polypropylene film.

(Metal foil layer)
The metal foil layer 4 plays a role of imparting gas barrier properties to the molding packaging material 1 to prevent oxygen and moisture from entering. Although it does not specifically limit as said metal foil layer 4, For example, aluminum foil, copper foil, stainless steel foil etc. are mentioned, Aluminum foil is generally used. The thickness of the metal foil layer 4 is preferably 20 μm to 100 μm. When it is 20 μm or more, it can prevent the occurrence of pinholes during rolling when producing metal foil, and when it is 100 μm or less, it can reduce the stress at the time of stretch forming or draw forming and improve the formability. it can.

The metal foil layer 4 is preferably subjected to a chemical conversion treatment on at least the inner surface 4a (surface on the second adhesive layer 6 side) (see FIGS. 1 and 2). By such chemical conversion treatment, corrosion of the surface of the metal foil due to the contents (battery electrolyte, food, medicine, etc.) can be sufficiently prevented. For example, the metal foil is subjected to chemical conversion treatment by the following treatment. That is, for example, on the surface of the metal foil that has been degreased,
1) An aqueous solution of a mixture containing phosphoric acid, chromic acid, and at least one compound selected from the group consisting of a fluoride metal salt and a fluoride non-metal salt 2) phosphoric acid, an acrylic resin, An aqueous solution of a mixture comprising at least one resin selected from the group consisting of chitosan derivative resins and phenolic resins, and at least one compound selected from the group consisting of chromic acid and chromium (III) salts 3) phosphoric acid And at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins, at least one compound selected from the group consisting of chromic acid and chromium (III) salts, and fluoride After applying one of the aqueous solutions of the mixture containing at least one compound selected from the group consisting of a metal salt and a non-metal salt of fluoride, it is dried. A chemical conversion process by the applying.

(Colored ink layer)
The colored ink layer 10 is a layer disposed between the metal foil layer 4 and the heat resistant resin layer 2. In the embodiment, the first adhesive layer 5 and the heat resistant resin layer 2 are provided. It is a layer which gives a color (including an achromatic color) to the outer surface side of the packaging material 1 for molding.

  The colored ink layer 10 includes a two-component curable polyester urethane resin binder (B) made of a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent, and a colored pigment (A) containing an inorganic pigment. It consists of a cured film of an ink composition.

  As the colored pigment (A), a configuration including at least an inorganic pigment is employed. Examples of the color pigment include azo pigments, phthalocyanine pigments, and condensed polycyclic pigments in addition to the inorganic pigments. In addition, the inorganic pigment is not particularly limited, and examples thereof include carbon black, calcium carbonate, titanium oxide, zinc oxide, iron oxide, and aluminum powder. Among these, carbon black is preferably used as the inorganic pigment. As the inorganic pigment, those having an average particle diameter of 0.1 μm to 5 μm are preferable, and those having an average particle diameter of 0.5 μm to 2.5 μm are particularly preferable. When dispersing the color pigment, it is preferable to disperse the color pigment using a pigment disperser. In dispersing the colored pigment, a pigment dispersant such as a surfactant may be used.

  It is preferable that 50% by mass or more of the colored pigment (A) is composed of the inorganic pigment. In this case, it is possible to form a colored ink layer 10 having a specific color tone that can sufficiently provide a hiding power for hiding the metal foil layer 4 and sufficiently impart a heavy feeling and a high-class feeling. Among these, it is more preferable that 60% by mass or more of the colored pigment (A) is composed of the inorganic pigment.

  The two-component curable polyester urethane resin binder (B) will be described. The polyester resin as the main agent is a copolymer using dicarboxylic acid and dialcohol as raw materials, and preferred materials and compositions are as follows.

  As the dicarboxylic acid, it is preferable to use both aliphatic dicarboxylic acid and aromatic dicarboxylic acid. In addition, the odd / even number of the methylene number of the methylene chain of the aliphatic dicarboxylic acid is a factor affecting the crystallinity of the resin, and the carboxylic acid having an even number of methylene produces a hard resin with high crystallinity. It is preferable to use an aliphatic dicarboxylic acid having methylene. Examples of the aliphatic dicarboxylic acid having an even number of methylene numbers include succinic acid (methylene number 2), adipic acid (methylene number 4), suberic acid (methylene number 6), and sebacic acid (methylene number 8). Examples of the aromatic dicarboxylic acid include isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and phthalic anhydride.

  Further, by setting the content of the aromatic dicarboxylic acid to the total amount of the aliphatic dicarboxylic acid and the aromatic dicarboxylic acid in the range of 40 mol% to 80 mol%, in other words, the content of the aliphatic dicarboxylic acid is 20 mol. % To 60 mol%, a resin having high adhesive strength and good moldability can be produced, and can be molded into a case having good moldability and a high side wall, and the heat-resistant resin layer 2 can be colored. A molding packaging material that can sufficiently prevent peeling from the ink layer 10 can be obtained. When the content of the aromatic dicarboxylic acid is less than 40 mol%, the film physical properties are deteriorated and aggregation peeling is likely to occur, and peeling from the colored ink layer 10 of the heat resistant resin layer 2 is likely to occur. Absent. On the other hand, if the content of the aromatic dicarboxylic acid exceeds 80 mol%, the resin tends to be hard and the adhesion performance tends to deteriorate, such being undesirable. Especially, it is especially preferable to make content rate of aromatic dicarboxylic acid with respect to the total amount of aliphatic dicarboxylic acid and aromatic dicarboxylic acid into the range of 50 mol%-70 mol%.

  The dialcohol is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, 1,3 butanediol, 1,4-butanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,5- Examples include pentanediol, 1,6-hexanediol, octanediol, 1,4-cyclohexanediol, 2-butyl-2-ethyl-1,3-propanediol, and the like.

  The molecular weight of the polyester resin (main agent) is defined such that the number average molecular weight (Mn) is in the range of 8000 to 25000, the weight average molecular weight (Mw) is in the range of 15,000 to 50000, and the ratio (Mw / Mn) is 1. 3 to 2.5. The number average molecular weight (Mn) is 8000 or more, and the weight average molecular weight (Mw) is 15000 or more, thereby obtaining appropriate coating strength and heat resistance, and the number average molecular weight (Mn) is 25000 or less. When the weight average molecular weight (Mw) is 50000 or less, an appropriate coating film elongation can be obtained without becoming too hard. Moreover, when these ratios (Mw / Mn) are 1.3 to 2.5, an appropriate molecular weight distribution is obtained, and the balance between adhesive application suitability (wide distribution) and performance (narrow distribution) can be maintained. it can. The polyester resin has a particularly preferred number average molecular weight (Mn) of 10,000 to 23,000, a particularly preferred weight average molecular weight (Mw) of 20,000 to 40,000, and a particularly preferred (Mw / Mn) of 1.5 to 2.3. is there.

  The molecular weight of the polyester resin (main agent) can be adjusted by chain extension with a polyfunctional isocyanate. That is, when the polyester component in the main agent is connected by NCO, a polymer having a hydroxyl group at the end is generated, and the molecular weight of the polyester resin (main agent) can be adjusted by adjusting the equivalent ratio of the isocyanate group to the hydroxyl group of the polyester. In the present invention, it is preferable to use those connected so that their equivalent ratio (OH / NCO) is 1.01 to 10. Another method for adjusting the molecular weight is to adjust the reaction conditions for the copolymerization reaction of dicarboxylic acid and dialcohol (mixing molar ratio of dicarboxylic acid and dialcohol).

  An epoxy resin or an acrylic resin may be added as an additive of the main agent (an additive of the colored ink composition).

  In addition, as the polyester resin (main agent), when any one or more of the limited configurations listed as suitable configurations is adopted, a configuration in which 50% by mass or more of the color pigment is configured with an inorganic pigment is employed. However, there exists an advantage which can ensure more sufficient adhesive force as a colored ink layer. A suitable configuration of the polyester resin (main agent) is particularly technically important in that such an effect can be obtained.

  As the polyfunctional isocyanate compound as the curing agent, various aromatic, aliphatic and alicyclic polyfunctional isocyanate compounds can be used. Specific examples include one or more diisocyanates such as aliphatic hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), aromatic tolylene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI). And polyfunctional isocyanate-modified products modified based on the above. As modification means, in addition to adducts with polyfunctional active hydrogen compounds such as water, glycerin, and trimethylolpropane, polyfunctional isocyanate modified products by a multimerization reaction such as isocyanuration, carbodiimidization, and polymerization can be mentioned. These 1 type (s) or 2 or more types can also be mixed and used.

  As a polyfunctional isocyanate compound as said hardening | curing agent, the 50 mol% or more (50 mol% or more and 100 mol% or less) is comprised with an aromatic polyfunctional isocyanate compound. That is, 50 mol% or more is composed of an aromatic polyfunctional isocyanate compound with respect to 100 mol% of the total amount of the polyfunctional isocyanate compound. By comprising 50 mol% or more of an aromatic polyfunctional isocyanate compound, the adhesive strength after curing can be increased, so even when deeper molding is performed, at the time of molding or sealing, Furthermore, the heat resistant resin layer 2 can be sufficiently prevented from peeling off from the colored ink layer 10 when used in a slightly severe environment such as high temperature and high humidity. Among them, the polyfunctional isocyanate compound as the curing agent is preferably composed of 70 mol% or more of an aromatic polyfunctional isocyanate compound, and more than 80 mol% of an aromatic polyfunctional isocyanate compound. It is particularly preferable to do this.

  In addition, when any one or more of the limited configurations listed as a preferable configuration is adopted as the polyfunctional isocyanate compound (curing agent), a configuration in which 50% by mass or more of the colored pigment is configured with an inorganic pigment. Even if it employ | adopts, there exists an advantage which can ensure more sufficient adhesive force as a colored ink layer. A suitable configuration of the polyfunctional isocyanate compound (curing agent) is particularly technically important in that such an effect can be obtained.

  In the two-component curable polyester urethane resin binder, the blending ratio of the main agent and the curing agent is preferably blended at a ratio of 2 to 25 moles of isocyanate functional group (NCO) with respect to 1 mole of polyol hydroxyl group (OH). . When the molar ratio (NCO) / (OH) is less than 2 and the isocyanate functional group (NCO) is decreased, there is a possibility that adequate coating strength and heat resistance cannot be obtained without sufficient curing reaction. On the other hand, when (NCO) / (OH) exceeds 25 and the number of isocyanate functional groups (NCO) increases, the reaction with functional groups other than polyol proceeds so much that the coating film becomes too hard to obtain suitable elongation. There is a fear. A particularly preferred molar ratio (NCO) / (OH) of polyol hydroxyl group to isocyanate functional group is 5-20.

  In the two-component curable polyester urethane resin binder, the cured film after the reaction preferably has the following physical properties. That is, a configuration in which the Young's modulus by a tensile test (JIS K7162) of the cured film after the main agent and the curing agent have reacted is preferably 70 MPa to 400 MPa. A particularly preferred Young's modulus is 100 MPa to 300 MPa. Moreover, it is preferable that the breaking strength of the cured film is 20 MPa to 70 MPa, and the breaking elongation of the cured film is 50% to 400%. A particularly preferred breaking strength is 30 MPa to 50 MPa, and a particularly preferred breaking elongation is 100% to 300%. Furthermore, it is preferable that the tensile stress-strain curve (SS curve) of the cured film of the two-component curable polyester urethane resin binder does not show a decrease in strength before breaking. FIG. 3 shows three patterns of SS curves. In pattern A, the strain amount is small and the strain amount in pattern B is large with respect to the tensile stress, but in all cases, the strain amount increases with the increase in tensile stress, and no decrease in strength before breakage is observed. On the other hand, in pattern C, the tensile stress is reduced in the process of increasing the strain amount, and the strength is reduced before breaking. In the present invention, it is preferable that the cured film of the two-component curable adhesive does not have a strength decrease in the SS curve. More preferably, there is no inflection point at which the intensity changes abruptly in the SS curve.

  The adhesive containing the two-component curable polyester urethane resin is a polycondensation of dicarboxylic acid and dialcohol, which are raw materials of the polyester resin, and if necessary, chain extension with a polyfunctional isocyanate, solvent and urethanization reaction Various additives such as catalysts, coupling agents for improving adhesive strength, epoxy resins, antifoaming agents, leveling agents, UV absorbers and antioxidants are mixed to form a fluid polyester resin liquid, and this is a curing agent. Can be prepared as a low-viscosity fluid by blending a polyfunctional isocyanate compound or a solvent.

  In the colored ink layer 10, the ratio of the content mass of the color pigment to the total mass of the polyester resin (the main component of the two-component curable polyester urethane resin binder) and the color pigment (which naturally does not include a solvent) is 5 mass%. It is preferably set to ˜60% by mass. The effect of concealing the metal foil layer 4 can be sufficiently obtained when it is 5% by mass or more, and the metallic luster is not visually recognized. There is no partial color unevenness. Further, when the amount is 60% by mass or less, the colored ink layer 10 does not become hard or brittle, and the adhesive strength of the colored ink layer 10 to the heat-resistant resin layer 2 can be sufficiently ensured. In addition, it is possible to sufficiently prevent the heat-resistant resin layer 2 from being peeled off from the colored ink layer 10 at the time of sealing and when used in a somewhat severe environment such as high temperature and high humidity. Among these, in the colored ink layer 10, the ratio of the content mass of the color pigment to the total mass of the polyester resin and the color pigment is particularly preferably set to 15% by mass to 50% by mass.

  The thickness of the colored ink layer (cured film) 10 is preferably set to 1 μm to 5 μm.

(First adhesive layer)
The first adhesive layer 5 is a layer responsible for joining the metal foil layer 4 and the heat resistant resin layer 2 (colored ink layer 10 in the above embodiment). Although it does not specifically limit as said 1st adhesive bond layer 5, For example, the adhesive bond layer etc. which were formed with the 2 liquid hardening type adhesive agent are mentioned. As the two-component curable adhesive, for example, a first liquid composed of one or more of polyols selected from the group consisting of polyurethane-based polyols, polyester-based polyols, polyether-based polyols and polyester-urethane-based polyols; Examples thereof include a two-part curable adhesive composed of a second liquid (curing agent) made of isocyanate. Among them, a two-component curable type composed of a first liquid consisting of one or more polyols selected from the group consisting of polyester polyols and polyester urethane polyols and a second liquid (curing agent) consisting of isocyanate. It is preferable to use an adhesive. For example, the first adhesive layer 5 is made of an adhesive such as the two-component curable adhesive on the upper surface of the metal foil layer 4 and / or the lower surface of the heat-resistant resin layer 2 (for example, the colored ink layer 10). It is formed by applying to the lower surface by a technique such as gravure coating.

  The method for bonding the metal foil layer 4 and the heat resistant resin layer 2 is not particularly limited, but a method called dry lamination can be recommended. Specifically, the prepared first adhesive is applied to the upper surface of the metal foil layer 4 or the lower surface of the heat-resistant resin layer 2 (the lower surface of the colored ink layer 10 in the above embodiment), or both of these surfaces. After evaporating the solvent to form a dry film, the metal foil layer 4 and the heat resistant resin layer 2 are bonded together. Thereafter, curing is performed according to the curing conditions of the first adhesive. Thereby, the metal foil layer 4 and the heat resistant resin layer 2 are joined via the first adhesive layer 5. Examples of the method for applying the first adhesive include a gravure coating method, a reverse roll coating method, and a lip roll coating method.

(Second adhesive layer)
The second adhesive layer 6 is not particularly limited. For example, a polyurethane adhesive, an acrylic adhesive, an epoxy adhesive, a polyolefin adhesive, an elastomer adhesive, and a fluorine adhesive. And an adhesive layer formed of an acid-modified polypropylene adhesive or the like. Among these, it is preferable to use an acrylic adhesive or a polyolefin adhesive. In this case, the electrolytic solution resistance and the water vapor barrier property of the molding packaging material 1 can be improved.

  The method of bonding the metal foil layer 4 and the thermoplastic resin layer 3 is not particularly limited, but the second adhesive is applied in the same manner as the bonding of the metal foil layer 4 and the heat resistant resin layer 2 described above. Then, after drying, a dry laminating method in which the metal foil layer 4 and the thermoplastic resin layer 3 are bonded together can be exemplified.

  The molding packaging material 1 of the present invention is not particularly limited to the laminated structure shown in FIG. 1, and further functions can be improved as a packaging material by adding layers. The molding packaging material 1 shown in FIG. 2 is obtained by further forming a mat coat layer 20 on the outer surface of the heat resistant resin layer 2 in the packaging material having the configuration shown in FIG.

(Matte coat layer)
The mat coat layer 20 is a surface layer provided to give good slipperiness to the surface of the molding packaging material 1 and improve the moldability.

  The mat coat layer 20 is a mat coat layer made of a resin composition in which inorganic fine particles are dispersed and contained in a heat resistant resin component. Among them, the mat coat layer 20 is composed of a resin composition in which inorganic fine particles having an average particle diameter of 1 μm to 10 μm are contained in a two-component curable heat-resistant resin in an amount of 0.1% by mass to 1% by mass. Is preferred. Examples of the heat resistant resin include acrylic resins, epoxy resins, polyester resins, urethane resins, polyolefin resins, fluorine resins, phenoxy resins, and the like, which are excellent in heat resistance and chemical resistance. In this respect, it is preferable to use a fluororesin based on tetrafluoroethylene or fluoroethylene vinyl ether. The inorganic fine particles are not particularly limited, and examples thereof include silica, alumina, calcium oxide, calcium carbonate, calcium sulfate, calcium silicate, and the like. Among these, silica is preferably used.

  The mat coat layer 20 can be formed by applying and curing the above-described mat coat composition containing the inorganic fine particles and the heat resistant resin on the surface of the heat resistant resin layer 2.

  The mat coat layer 20 preferably has a thickness (thickness after curing) of 0.5 μm to 5 μm. A slip improvement effect can be sufficiently obtained by being at least the preferred lower limit, and costs can be suppressed by being at most the preferred upper limit. Among them, the thickness of the mat coat layer 20 (thickness after curing) is particularly preferably 1 μm to 3 μm.

  The gloss value of the surface of the mat coat layer 20 is preferably set to 1% to 15% as a 60 ° reflection angle measurement value based on JIS Z8741. The gloss value is a value obtained by measuring at a 60 ° reflection angle with a gloss measuring device “micro-TRI-gloss-s” manufactured by BYK.

  In addition, although the implementation time (execution order) of the process of forming the mat coat layer 20 is not particularly limited, the heat resistant resin layer is formed on the metal foil layer 4 (via the first adhesive layer 5 and the colored ink layer 10). It is preferable to carry out following the step of bonding 2 together.

  In the above embodiment, a configuration in which the mat coat layer 20 is laminated on the upper surface of the heat resistant resin layer 2 is adopted, but this mat coat layer 20 is not an essential component layer, as shown in FIG. A configuration without the mat coat layer 20 may be adopted.

  Moreover, in the said embodiment, although the structure which provided the 1st adhesive bond layer 5 and the 2nd adhesive bond layer 6 is employ | adopted, these both layers 5 and 6 are not an essential structural layer, These are these. It is also possible to adopt a configuration that is not provided.

  The molding packaging material 1 of the present invention is not limited to the one manufactured by the above-described manufacturing method including the bonding method of each layer, and the one manufactured by another manufacturing method is also included in the present invention. included.

  A molding case (battery case or the like) can be obtained by molding the molding packaging material 1 of the present invention (deep drawing molding, stretch molding or the like).

  Moreover, although the packaging material 1 for shaping | molding which concerns on this invention is used suitably as a packaging material for lithium ion secondary battery cases, it is not specifically limited to such a use.

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

<Example 1>
By applying a chemical conversion treatment solution consisting of polyacrylic acid, trivalent chromium compound, water and alcohol on both sides of an aluminum foil (A8079 aluminum foil) 4 having a thickness of 35 μm and drying at 150 ° C., a chemical conversion film is formed on both sides. The aluminum foil which formed was prepared. The amount of chromium deposited by this chemical film was 5 mg / m ^{2 on} one side.

  A polyester resin (polyester polyol) which is a main component of a two-component curable polyester urethane resin binder is prepared. 30 mol parts of neopentyl glycol, 30 mol parts of ethylene glycol and 40 mol parts of 1,6-hexanediol are melted at 80 ° C., and 30 mol parts of adipic acid which is an aliphatic dicarboxylic acid and aromatic dicarboxylic acid are stirred. A polycarboxylic acid mixture composed of 70 parts by mole of isophthalic acid was subjected to a condensation polymerization reaction at 210 ° C. for 20 hours to obtain a polyester polyol (polyester resin) as a main agent. This polyester polyol has a number average molecular weight (Mn) of 12000, a weight average molecular weight (Mw) of 20500, and a ratio thereof (Mw / Mn) of 1.71. Further, 60 parts by mass of ethyl acetate was added to 40 parts by mass of the obtained polyester polyol to obtain a fluid polyester polyol resin solution. In this polyester polyol resin solution, the hydroxyl value of the polyester polyol was 2.2 mgKOH / g (solution value).

  Next, 13.3 parts by mass of carbon black having an average particle size of 1.0 μm, 100 parts by mass of the polyester polyol resin solution (40 parts by mass of polyester polyol), and 64.4 parts by mass of ethyl acetate were mixed, and then a pigment disperser. Was used to disperse the carbon black pigment to obtain a base ink composition. The content of the solid components (polyester polyol and carbon black) in the main component ink composition is 30% by mass, and the content of the color pigment (carbon black) in the solid components is 25% by mass.

  Adduct body of tolylene diisocyanate (TDI) and trimethylolpropane (NCO%: 13.0%, solid content: 75% by mass; aromatic polyfunctional) as a curing agent with respect to 100 parts by mass of the main ink composition A colored ink composition was obtained by blending 7.1 parts by mass of an isocyanate compound) and further mixing 34.1 parts by mass of ethyl acetate and stirring.

  In the colored ink composition, the molar ratio (NCO / OH) of the isocyanate functional group (NCO) to the polyester polyol hydroxyl group (OH) is 10.

  Next, the colored ink layer 10 was formed by applying and drying the colored ink composition on one surface of a biaxially stretched nylon film (heat-resistant resin layer) 2 having a thickness of 15 μm. The thickness of the colored ink layer 10 after drying was 3 μm.

  Next, a two-component curable polyester urethane resin adhesive is applied to one surface of the aluminum foil 4 having the chemical conversion film formed on both sides and dried to form the first adhesive layer 5. The colored ink layer 10 side of the biaxially stretched nylon film 2 is bonded to the surface of the agent layer 5, and a polyacrylic adhesive is applied to the other surface of the aluminum foil 4 and dried to form a second adhesive layer 6. The unstretched polypropylene film (thermoplastic resin layer) 3 having a thickness of 30 μm was bonded to the surface of the second adhesive layer 6. By leaving this laminate for 5 days in a 40 ° C. environment, a molding packaging material 1 having the structure shown in FIG. 1 was obtained.

<Example 2>
Using the same starting materials as in Example 1, the number-average molecular weight (Mn) is 8900 and the weight-average molecular weight (Mw) is 15000 by adjusting the blending molar ratio of the total amount of diol component to the total amount of dicarboxylic acid as compared with Example 1. A polyester polyol having a ratio (Mw / Mn) of 1.69 was obtained.

  In place of the polyester polyol of Example 1, the above polyester polyol was used, and as a curing agent, an adduct of tolylene diisocyanate (TDI) and trimethylolpropane (NCO%: 13.0%, solid content: 75% by mass; 4.8 parts by mass of the aromatic polyfunctional isocyanate compound), and the molar ratio (NCO / OH) of the isocyanate functional group (NCO) and the polyester polyol hydroxyl group (OH) of the curing agent in the colored ink composition was 5. Except for the above, the molding packaging material 1 shown in FIG.

<Example 3>
The diisocyanate component of the curing agent of Example 1 was reacted with trimethylolpropane in a mixed isocyanate composed of 70 mol% of aromatic tolylene diisocyanate (TDI) and 30 mol% of hexamethylene diisocyanate (HDI) as an aliphatic isocyanate compound. The packaging material for molding 1 shown in FIG. 1 is the same as in Example 1 except that the polyfunctional isocyanate compound (NCO%: 13.0%, solid content: 75% by mass), which is an adduct obtained by the above process, is used. Got.

<Example 4>
Instead of mixing 13.3 parts by mass of carbon black having an average particle diameter of 1.0 μm, 100 parts by mass of a polyester polyol resin solution and 64.4 parts by mass of ethyl acetate in Example 1, carbon having an average particle diameter of 1.0 μm By mixing 4.4 parts by mass of black, 100 parts by mass of polyester polyol resin solution, and 43.6 parts by mass of ethyl acetate, the content ratio of carbon black to the total mass of polyester resin and carbon black was set to 10% by mass. Obtained the packaging material 1 for shaping | molding shown in FIG.

<Example 5>
Adduct body of tolylene diisocyanate (TDI) and trimethylolpropane (NCO%: 13.0%, solid content: 75% by mass; aromatic) with respect to 100 parts by mass of the base ink composition of Example 1 7.1 parts by weight of a polyfunctional isocyanate compound) and 34.1 parts by weight of ethyl acetate to obtain a colored ink composition, and curing with respect to 100 parts by weight of the base ink composition As an agent, 3.6 parts by mass of an adduct of tolylene diisocyanate (TDI) and trimethylolpropane (NCO%: 13.0%, solid content: 75% by mass; aromatic polyfunctional isocyanate compound) is further blended. By blending 31 parts by weight of ethyl acetate to obtain a colored ink composition, the isocyanate functional group (NCO) of the curing agent and the polyester polyol water Except that the molar ratio of (OH) groups of the (NCO / OH) and 5, in the same manner as in Example 1, to obtain a molded packaging material 1 shown in FIG.

<Example 6>
80 parts by mass of fluoroethylene vinyl ester (heat-resistant resin), 10 parts by mass of barium sulfate (inorganic fine particles), and 10 parts by mass of powdered silica (inorganic fine particles) were mixed to obtain a mat coat composition. This mat coat composition was applied to the surface of the biaxially stretched nylon film (heat resistant resin layer) 2 following the bonding of the biaxially stretched nylon film (heat resistant resin layer) 2 in the process of Example 1. A molding packaging material 1 having the structure shown in FIG. 2 was obtained in the same manner as in Example 1 except that the mat coat layer 20 having a thickness of 2 μm after drying was formed.

  When the gloss of the surface of the mat coat layer 20 was measured at a reflection angle of 60 ° using a gloss measuring device “micro-TRI-gloss-s” manufactured by BYK, the gloss value (JIS Z8741) of the surface of the mat coat layer 20 was measured. (Measured value of 60 ° reflection angle based on 1.9) was 1.9%.

<Comparative Example 1>
By using the same starting materials as in Example 1, the reaction conditions are changed (by adjusting the blending molar ratio of the total amount of diol component to the total amount of dicarboxylic acid as compared with Example 1), the number average molecular weight (Mn) is 6700, the weight average A polyester polyol having a molecular weight (Mw) of 8400 and a ratio (Mw / Mn) of 1.25 was obtained.

  A molding packaging material was obtained in the same manner as in Example 1 except that the above polyester polyol was used in place of the polyester polyol of Example 1. In the colored ink composition, the molar ratio (NCO / OH) of the isocyanate functional group (NCO) to the polyester polyol hydroxyl group (OH) was 4.

<Comparative Example 2>
As a curing agent, an adduct of tolylene diisocyanate (TDI) and trimethylolpropane of Example 1 (NCO%: 13.0%, solid content: 75% by mass; aromatic polyfunctional isocyanate compound) 7.1 parts by mass Instead of adduct (NCO%: 13.0%, solid) obtained by reacting trimethylolpropane with mixed isocyanate consisting of 30 mol% tolylene diisocyanate (TDI) and 70 mol% hexamethylene diisocyanate (HDI). 75% by mass; polyfunctional isocyanate compound) A packaging material for molding was obtained in the same manner as in Example 1 except that 7.1 parts by mass was used.

<Comparative Example 3>
As a curing agent, an adduct of tolylene diisocyanate (TDI) and trimethylolpropane of Example 2 (NCO%: 13.0%, solid content: 75% by mass; aromatic polyfunctional isocyanate compound) 4.8 parts by mass Instead of adduct (NCO%: 13.0%, solid) obtained by reacting trimethylolpropane with mixed isocyanate consisting of 30 mol% tolylene diisocyanate (TDI) and 70 mol% hexamethylene diisocyanate (HDI). 75% by mass; polyfunctional isocyanate compound) A packaging material for molding was obtained in the same manner as in Example 2 except that 4.8 parts by mass were used.

  Each molding packaging material obtained as described above was evaluated based on the following evaluation method. These results are shown in Table 1.

<Evaluation method of appearance (color unevenness) of molded products>
For each example and each comparative example, 30 molding packaging materials were produced, and after confirming with the naked eye that the heat-resistant resin layer 2 was not peeled from the aluminum foil 4, punches and dies Etc., in a mode in which the inner thermoplastic resin layer 3 is brought into contact with the punch, a molding case in which a deep drawing is performed in a rectangular parallelepiped shape of 50 mm in length, 35 mm in width, and 5.5 mm in depth, and a flange portion is provided around Was made.

The appearance of the produced molded case was visually observed from the heat-resistant resin layer side, and the presence or absence of color unevenness at the molding location was evaluated based on the following criteria.
(Criteria)
“◯”: Color irregularity was not recognized in all 30 “Δ”: Some color irregularities were observed “×”: Some color irregularities were observed.

<Evaluation method for the presence or absence of peeling>
For each of the examples and each of the comparative examples, 30 molding packaging materials were produced, and for these, the presence or absence of peeling of the heat-resistant resin layer was visually checked, and the following three a), b) and c) It investigated in the state and evaluated based on the following criteria.
(Criteria)
“◎”: 0 of 30 heat-resistant resin layers peeled from aluminum foil “◯”: 1 or 2 of 30 heat-resistant resin layers peeled from aluminum foil "△" ... the heat-resistant resin layer peeled from the aluminum foil is 3 to 5 out of 30 "x" ... the heat-resistant resin layer peeled off the aluminum foil is 30 , 6 to 30 pieces.

a) Molding packaging material immediately after deep drawing (that is, a molded case after the appearance evaluation of the molded product)
b) A flat molding packaging material (hereinafter referred to as “lid material”) before molding having the same configuration as the molding case of a) above was prepared. On the other hand, only the case where the heat-resistant resin layer was not peeled off was selected from the molding case a), and the lid member (peripheral edge portion) was overlapped on the flange portion of the molding case without peeling. Heat sealing was performed under conditions of 3 MPa × 6 seconds. Molding packaging material immediately after heat sealing c) From the molding case of a) above, only the one having no peeling of the heat-resistant resin layer was selected, and this molding case without peeling was selected as a high temperature and high humidity of 60 ° C. × 95% RH. Packaging material for molding after 5 days at room temperature after taking out for 72 hours in a testing machine.

<Evaluation of physical properties of cured film>
Cured film of the two-component curable polyester urethane resin binder used in Examples 1 to 6 and Comparative Examples 1 to 3 (that is, a cured film of a composition having a composition obtained by removing the colorant carbon black from each colored ink composition; Then, a cured film in which the main agent and the curing agent reacted was prepared, and the physical properties of the cured film were evaluated.

  That is, a two-component curable polyester urethane resin binder is applied to a non-adhesive untreated PP film so that the thickness after drying is 50 μm, and after the solvent is dried, the residual isocyanate becomes 5% or less. Aged at 60 ° C. until cured to form a cured film. After the cured film was peeled from the untreated PP film, the cured film was cut into a long material having a width of 15 mm and a length of 100 mm to obtain a test piece.

  The created test piece was subjected to a tensile test in accordance with JIS K7162 under the conditions of a distance between gauge points of 50 mm and a tensile speed of 200 mm / min, and the Young's modulus, breaking strength and breaking elongation were measured. Moreover, when the SS curve in this tensile test was calculated | required, the pattern was the pattern A shown in FIG. 3 in Examples 1-6, and the pattern B shown in FIG.

  As is apparent from Table 1, the packaging materials for molding of Examples 1 to 6 of the present invention are used in a high temperature and high humidity environment without the heat resistant resin layer being peeled off during molding and heat sealing. Even when heated, the heat-resistant resin layer hardly peels off.

  In contrast, in the molding packaging material of Comparative Example 1 in which the molecular weight of the polyester resin as the main component deviates from the specified range of the present invention, the heat resistance is high after heat sealing and after being used in a hot and humid environment. Many of the resin layers peeled off. Further, in the molding packaging materials of Comparative Examples 2 and 3 in which the content of the aromatic polyfunctional isocyanate compound in the polyfunctional isocyanate compound as the curing agent is less than 50 mol%, the heat-sealing and high-temperature and high-humidity environment After use, the heat resistant resin layer often peeled off.

  The molding packaging material according to the present invention is suitably used as a battery case for notebook computers, mobile phones, in-vehicle, stationary lithium ion polymer secondary batteries and the like. Although suitable as a packaging material for pharmaceuticals, it is not particularly limited to these uses. Among these, it is particularly suitable for battery cases.

1 ... Molding packaging material 2 ... Heat-resistant resin layer (outer layer)
3 ... Thermoplastic resin layer (inner layer)
4 ... Metal foil layer 10 ... Colored ink layer

Claims (7)

A heat-resistant resin layer as an outer layer, a thermoplastic resin layer as an inner layer, a metal foil layer disposed between these two layers, and disposed between the metal foil layer and the heat-resistant resin layer A packaging material for molding including a colored ink layer,
The colored ink layer is
A two-component curable polyester urethane resin binder comprising a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent;
A colored ink composition comprising an inorganic pigment and a colored pigment,
The polyester resin as the main agent has a number average molecular weight (Mn) of 8000 to 25000, a mass average molecular weight (Mw) of 15,000 to 50000, and a ratio (Mw / Mn) of 1.3 to 2.5. And
A molding packaging material, wherein 50 mol% or more of the polyfunctional isocyanate compound as the curing agent is an aromatic polyfunctional isocyanate compound.   The molding packaging material according to claim 1, wherein in the colored ink layer, the ratio of the content mass of the color pigment to the total mass of the polyester resin as the main agent and the color pigment is 5 mass% to 60 mass%.   The molding packaging material according to claim 1 or 2, wherein 50% by mass or more of the colored pigment is composed of the inorganic pigment.   4. The Young's modulus of the two-component curable polyester urethane resin binder is 70 MPa to 400 MPa according to a tensile test (JIS K7162) of the cured film after the main agent and the curing agent are reacted. The molding packaging material according to Item.   The molding packaging material according to any one of claims 1 to 4, wherein a chemical conversion film is formed on at least one surface of the metal foil layer.   A molded case formed by deep-drawing or stretch-molding the molding packaging material according to any one of claims 1 to 5.   The molded case according to claim 6, which is used as a battery case.

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