CN217073665U - Laminate and outer package for battery - Google Patents

Abstract

The utility model relates to a laminated material and an outer packaging body for batteries. Provides a laminate that does not peel off the heat-resistant resin layer during molding, sealing, and use in a slightly harsh environment such as high temperature and high humidity. The laminate (1) comprises: a heat-resistant resin layer (13) as an outer layer; a heat-fusible resin layer (15) as an inner layer; a metal foil layer (10) disposed between the two layers; and A colored layer (12) disposed between the metal foil layer (10) and the heat-resistant resin layer (13), the colored layer (12) is formed of a coloring composition containing a resin binder and a colorant, and is made of coloring A multi-layer formed by laminating two or more layers with different agent contents, the colorant content in the layer (12a) in contact with the heat-resistant resin layer (13) is lower than that in the other layers (12b) .

Description

Laminate and battery outer package

technical field

The utility model relates to a case suitable for use as, for example, a notebook computer, a mobile phone, a vehicle, a stationary secondary battery (lithium ion secondary battery), and a packaging material for food and a packaging material for pharmaceuticals of the laminate.

Background technique

Batteries such as lithium ion secondary batteries are increasingly required to be colored in order to match the appearance and color of equipment such as electrical equipment to be installed. For example, in order to give a thick and luxurious feeling, many devices are made of black, and in this case, the battery is also increasingly made of black.

Such a battery is formed by packaging a battery body with a packaging material (molded case), and the packaging material is usually a laminate in which a base resin layer is laminated on both surfaces of a metal foil. In addition, among the coloring of the battery, there are coloring of the base resin layer used in the packaging material of the battery, providing a colored printing layer under the base resin layer, and bonding between the base resin layer and the metal foil. When the base resin layer is composed of a plurality of layers, the adhesive layer between these layers is colored, and the like.

Conventionally, as a battery packaging material having a colored layer, a structure in which a base material layer, an adhesive layer, a metal foil layer, and a thermal adhesive resin layer are laminated in this order is known, and the base material layer, the adhesive One of the adhesive layer and the metal foil layer contains pearlescent pigments and fluorescent pigments as identification marks (see Patent Document 1); it has a base material layer, an adhesive layer, a metal foil layer, and a thermal adhesive resin layer in this order In the laminated structure, a pigment as an identification mark is added to any one of the base material layer, the adhesive layer, and the metal foil layer (see Patent Document 2).

In addition, there is known a battery outer packaging material (see Patent Document 3) which includes a black body material layer such as a carbon material between the metal foil layer and the outer layer film in order to improve the heat dissipation of the battery.

prior art literature

Patent Literature

Patent Document 1: International Publication No. 2011/016506 Pamphlet

Patent Document 2: Japanese Patent Laid-Open No. 2011-054563

Patent Document 3: Japanese Patent Laid-Open No. 2011-096552

Utility model content

The problem to be solved by the utility model

Generally, when a film or a sheet is colored black, a printing layer is generally provided with a printing ink containing an inorganic pigment such as carbon black.

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

That is, when the above-mentioned black packaging material is formed into a container (shell) shape by deep drawing or bulging, there is a problem that the outer resin layer is peeled from the black printed layer of the packaging material. Such peeling of the outer resin layer occurs during sealing of the black packaging material after enclosing the electrodes and the electrolyte solution, and also when the battery packaged with the black packaging material is used in a slightly severe environment such as high temperature and high humidity. The above problems are not limited to black packaging materials using carbon black, but also occur in colored packaging materials that are similarly colored in various colors using other inorganic pigments.

means of solving problems

The present invention is proposed in view of the above technical background, and aims to provide a laminated material whose heat-resistant resin layer does not peel off during molding and sealing, and when used in a slightly severe environment such as high temperature and high humidity.

That is, this invention has the structure as described in [1] - [8].

[1] A laminate comprising: a heat-resistant resin layer as an outer layer; a heat-fusible resin layer as an inner layer; a metal foil layer disposed between the two layers; and a colored layer disposed on the metal Between the foil layer and the above-mentioned heat-resistant resin layer, the above-mentioned laminated material is characterized in that:

The above-mentioned colored layer is formed of a colored composition containing a resin binder and a colorant, and the above-mentioned colored layer is a multi-layer formed by laminating two or more layers having different contents of the colorant, and is in contact with the above-mentioned heat-resistant resin layer The content of the colorant in the layer is lower than that in the other layers.

[2] The laminate according to the above item 1, wherein, in the coloring composition of the layer constituting the coloring layer in contact with the heat-resistant resin layer, the amount of the colorant in the solid content of the coloring composition is The content rate is 5 mass % or less.

[3] The laminate according to the above item 1, wherein in the coloring composition of the layers constituting the coloring layer other than the layer in contact with the heat-resistant resin layer, the solid content of the coloring composition is in the coloring composition. The content rate of the colorant is 5% by mass to 60% by mass.

[4] The laminate according to the above item 1, wherein the coloring composition of each layer of the coloring layer contains a common resin binder.

[5] The laminate according to the above item 1, wherein an adhesive layer is disposed between the colored layer and the metal foil layer, and the adhesive layer contains a resin with a coloring composition constituting the colored layer The same resin composition as the adhesive.

[6] The laminate according to any one of 1 to 5 above, wherein, in the above-mentioned coloring composition,

The above-mentioned resin adhesive is a two-liquid curable polyester urethane resin adhesive formed of a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent,

The number-average molecular weight of the above-mentioned polyester resin as the main agent, that is, Mn, is 8,000 to 25,000, and the mass-average molecular weight, that is, Mw, is 15,000 to 50,000.

50 mol% or more of the polyfunctional isocyanate compound which is the said hardening|curing agent is an aromatic polyfunctional isocyanate compound.

[7] The laminate according to the above item 1, wherein a protective layer containing a resin component and a filler component is laminated on the outer side of the heat-resistant resin layer.

[8] An outer package for a battery, wherein the merging edge portion is heat-sealed with the laminate according to any one of the preceding items 1 to 7 such that the heat-fusible resin layers face inwards, Thus, a battery element chamber in which the battery element is accommodated is formed.

The effect of the utility model

According to the laminate described in the above [1], by setting the colorant content of the layer in contact with the corrosion-resistant resin layer in the multilayered colored layers to be lower than that of the other layers, it is possible to improve the resistance to heat resistance. Adhesion of the resin layer. Therefore, even when the laminate is used in a slightly severe environment such as high temperature and high humidity, the heat-resistant resin layer is not easily peeled off. Furthermore, by preventing a non-colored layer from being present between the heat-resistant resin layer and another layer having a high colorant content, it is possible to avoid blurring or blurring of color development of the colored layer, and to obtain a stable color development state.

According to the laminate described in the above [2], in the coloring composition of the layer that is in contact with the corrosion-resistant resin layer among the colored layers constituting the multilayer, the colorant is contained in the solid content of the coloring composition due to the content of the colorant. Since the ratio is 5 mass % or less, high adhesiveness can be obtained with respect to the heat-resistant resin layer.

According to the laminate described in the above [3], in the coloring composition of the layers other than the layer in contact with the corrosion-resistant resin layer among the colored layers constituting the multilayer, the coloring in the solid content of the coloring composition is The content of the agent is 5% by mass to 60% by mass, so that the effect of shielding the metal foil layer can be sufficiently obtained, the metallic luster can be prevented from being visually recognized, and a thick and high-quality feeling can be sufficiently provided, and color unevenness is not caused. In addition, hardening and brittleness of the above-mentioned layer can be avoided, and sufficient adhesive force can be ensured.

According to the laminate described in the above [4], since the coloring composition of each layer of the coloring layer contains a common resin binder, the adhesion between layers is improved, and the layer with a high colorant content is more difficult to peel.

According to the laminate described in the above [5], the adhesive layer containing the same resin component as the resin adhesive of the coloring composition constituting the above-mentioned colored layer is arranged between the colored layer and the metal foil layer, so that the metal The foil layer and the colored layer are more difficult to peel off.

According to the laminate described in the above [6], particularly high adhesiveness can be obtained by the predetermined resin binder of the coloring composition constituting each layer of the coloring layer.

According to the laminate described in the above [7], since the matte coating can be used to give the surface good sliding properties, sliding between the heat-resistant resin layer and the colored layer is unlikely to occur during molding, etc., and the heat-resistant resin layer is The layer becomes difficult to peel from the colored layer.

According to the battery outer package described in the above [8], since the heat-resistant resin layer of the laminate material is not easily peeled off, even when the battery is used in a slightly severe environment such as high temperature and high humidity, the heat-resistant resin layer does not partially cracked and peeled off.

Description of drawings

FIG. 1 is a cross-sectional view of one embodiment of the laminate of the present invention.

FIG. 2 is a perspective view of a test material.

Description of reference numerals

1...laminate

10…Metal foil layer

11...1st adhesive bond layer

12...coloring layer

12a…Tier 1

12b…Tier 2

13...heat-resistant resin layer

14...Second adhesive layer

15...Thermal fusion resin layer

Detailed ways

One embodiment of the laminate 1 of the present invention is shown in FIG. 1 . This laminate is used as a material for an outer package (case) for a lithium ion secondary battery.

The laminated material 1 has a first adhesive layer 11 , a colored layer 12 and a heat-resistant resin layer 13 laminated in this order from the metal foil layer 10 side on one surface of the metal foil layer 10 , and on the other side of the metal foil layer 10 . The second adhesive 14 and the heat-fusible resin layer 15 are laminated and integrated on one surface in this order from the metal foil layer 10 side. When the laminated material 1 is used as an outer casing for a battery, the heat-resistant resin layer 13 is an outer layer, and the heat-sealing resin layer 15 is an inner layer.

The colored layer 12 is a layer disposed between the metal foil layer 10 and the heat-resistant resin layer 13, and in the above-described embodiment, is responsible for the bonding of the first adhesive layer 11 and the heat-resistant resin layer 13. A layer that imparts a color (including achromatic color) to the outer surface side of the laminate 1 .

[coloring layer]

The colored layer 12 has a two-layer structure in which a first layer 12a disposed in contact with the heat-resistant resin layer 13 and a second layer 12b on the metal foil layer 10 side are stacked. Each layer consists of a coloring composition containing a resin binder and a colorant. The content rate (A) of the colorant in the first coloring composition constituting the first layer 12a is set lower than the content rate (B) of the colorant in the second coloring composition constituting the second layer 12b. In this way, by setting the colorant content (A) in the first layer 12a to be low, the adhesiveness to the heat-resistant resin layer 13 can be improved, and the first layer 12a can function as a primer, and By being comprised so that a non-colored layer does not exist between the heat resistant resin layer 13 and the 2nd layer 12b, the color development of the coloring layer 12 can be prevented from being blurred or blurred, and a stable color development state can be obtained.

Moreover, it is preferable to set the thickness (cured film) of the said coloring layer 12 so that the 1st layer 12a is 0.1 micrometer - 3 micrometers, and the 2nd layer 12b is 2 micrometer - 5 micrometers.

(coloring composition)

As mentioned above, the 1st layer 12a and the 2nd layer 12b are comprised with the coloring composition containing a resin binder and a coloring agent, respectively.

In the first coloring composition constituting the first layer 12a of the coloring layer 12, the coloring pigment in the solid content of the first coloring composition is preferable from the viewpoint of improving the adhesiveness with respect to the heat-resistant resin layer 13. The content rate (A) of the powder is set to 5 mass % or less. Adding a large amount of the colorant leads to a decrease in adhesiveness, but if it is 5 mass % or less, sufficient adhesiveness can be ensured, and sufficient adhesiveness can be ensured during molding and sealing, and when used in a slightly severe environment such as high temperature and high humidity. The heat-resistant resin layer 13 is prevented from peeling from the colored layer 12 . In addition, from the viewpoint of obtaining a stable color development state of the colored layer 12, the content (A) is preferably 0.005 mass% or more. The especially preferable content ratio (A) of the coloring agent in the said 1st layer 12a is 0.01 mass % - 1 mass %.

In addition, the preferable adhesion amount of the colorant per unit area of the first layer 12a is 0.5 g/m ² to 2 g/m ² for the first layer 12 a and 2 g/m ² to 5 g/m for the second layer 12 b ² .

On the other hand, it is a necessary condition that the content rate (B) of the coloring pigment in the solid content of the second coloring composition constituting the second layer 12b of the coloring layer 12 is higher than the content rate (A) in the first layer 12a, Preferably, it is set to 5 mass % - 60 mass %. By setting the content rate (B) of the colorant to be 5 mass % or more, the effect of shielding the metal foil layer 10 can be sufficiently obtained, the metallic luster can be prevented from being visually recognized, and a heavy feeling and a high-quality feeling can be sufficiently imparted, and at the time of molding There is also no local color unevenness in the molded part. Moreover, by being 60 mass % or less, hardening or brittleness of the 2nd layer 12b can be avoided, and adhesive force can be fully ensured. The especially preferable content rate (B) of the coloring agent in the said 2nd layer 12b is 15 mass % - 50 mass %.

It is preferable that the resin binder which comprises the coloring composition of the said 1st layer 12a and the 2nd layer 12b is common. The common resin binder refers to the same or the same kind of resin binder, and by using such a resin binder, the adhesiveness of the first layer 12a and the second layer 12b is improved, and the colorant content rate is high. The second layer 12b is more difficult to peel off.

In addition, in the preparation process of the above-mentioned laminated material 1, for example, the first coloring composition is applied to one surface of the heat-resistant resin layer 13 to form a cured film of the first layer 12a, and then the second coloring is applied. The composition is used to form a cured film of the second layer 12b, whereby the colored layer 12 having a two-layer structure can be formed.

As the colorant, both pigments and dyes may be used, but pigments are preferred because they are excellent in color development and weather resistance. As the pigment, carbon black, calcium carbonate, zinc oxide, and aluminum powder can be exemplified. In addition, the average particle diameter of the pigment is preferably in the range of 0.1 µm to 5 µm, particularly preferably in the range of 0.5 µm to 2.5 µm.

As a resin component which comprises the said resin binder, a urethane type resin, an acrylic resin, a polyamide type resin, nitrocellulose (nitrocellulose), a vinyl chloride-vinyl acetate type resin, etc. can be illustrated. Among these resins, polyurethane-based resins are particularly preferred, and polyester urethane resins are further preferred.

In addition, the above-mentioned resin adhesive is a two-component curable polyester urethane resin adhesive composed of a polyester resin as a main ingredient and a polyfunctional isocyanate compound as a curing agent, and the number average of the polyester resin as the main ingredient is The molecular weight (Mn) is 8,000 to 25,000, the mass average molecular weight (Mw) is 15,000 to 50,000, the ratio (Mw/Mn) of these is 1.3 to 2.5, and preferably 50 mol% or more of the polyfunctional isocyanate compound used as the curing agent is aromatic. family of polyfunctional isocyanate compounds.

Hereinafter, the main ingredient and the curing agent in the above-mentioned two-component curable polyester urethane resin adhesive will be described in detail.

The polyester resin as the above-mentioned main ingredient is a copolymer using a dicarboxylic acid and a diol as raw materials, and preferable materials and compositions are as follows.

As the above-mentioned dicarboxylic acid, it is preferable to use both aliphatic dicarboxylic acid and aromatic dicarboxylic acid. In addition, the parity of the number of methylene groups in the methylene chain of the aliphatic dicarboxylic acid is a factor affecting the crystallinity of the resin, and a carboxylic acid having an even number of methylene groups produces a hard resin with high crystallinity, so it is preferable to use an even number of methylene groups. The methylene aliphatic dicarboxylic acid. Examples of aliphatic dicarboxylic acids having an even number of methylene groups include succinic acid (2 methylene groups), adipic acid (4 methylene groups), and suberic acid (6 methylene groups) , sebacic acid (the number of methylene groups is 8), etc. As said aromatic dicarboxylic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, phthalic anhydride, etc. can be illustrated.

In addition, by setting the content rate of the aromatic dicarboxylic acid with respect to the total amount of the aliphatic dicarboxylic acid and the aromatic dicarboxylic acid to be in the range of 40 mol % to 80 mol %, in other words, by making the aliphatic dicarboxylic acid When the acid content is in the range of 20 mol% to 60 mol%, a resin with high adhesive strength and good moldability can be produced, and a case with a high side wall can be formed with good moldability and sufficient A laminate that prevents peeling of the heat-resistant resin layer 13 from the colored layer 12 . If the content of the aromatic dicarboxylic acid is less than 40 mol %, the physical properties of the film are deteriorated, aggregation and peeling tend to occur, and peeling of the heat-resistant resin layer 13 from the colored layer 12 tends to occur, which is not preferable. On the other hand, when the content rate of the aromatic dicarboxylic acid exceeds 80 mol %, the resin tends to become hard and the adhesive performance tends to decrease, which is not preferable. Among them, it is particularly preferable to set the content rate of the aromatic dicarboxylic acid to the total amount of the aliphatic dicarboxylic acid and the aromatic dicarboxylic acid in the range of 50 mol % to 70 mol %.

Although it does not specifically limit as said glycol, For example, ethylene glycol, propylene glycol, 1, 3- butanediol, 1, 4- butanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1, 5 glycol can be illustrated. -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 ingredient) is defined as the number average molecular weight (Mn) in the range of 8,000 to 25,000, the weight average molecular weight (Mw) in the range of 15,000 to 50,000, and the ratio of these (Mw/Mn) is 1.3-2.5. Appropriate coating film strength and heat resistance can be obtained by making the number average molecular weight (Mn) 8,000 or more and the weight average molecular weight (Mw) 15,000 or more. (Mw) is 50000 or less, and it can avoid being too hard, and can obtain a suitable coating-film elongation. In addition, by setting the ratio (Mw/Mn) of the two to 1.3 to 2.5, an appropriate molecular weight distribution can be achieved, and the balance of the adhesive coating applicability (wide distribution) and performance (narrow distribution) can be maintained. The particularly preferred number average molecular weight (Mn) of the polyester resin is 10,000 to 23,000, the particularly preferred weight average molecular weight (Mw) is 20,000 to 40,000, and the particularly preferred (Mw/Mn) is 1.5 to 2.3.

The molecular weight of the polyester resin (main ingredient) can be adjusted by chain extension using a polyfunctional isocyanate. That is, by linking the polyester component in the main ingredient with NCO, a polymer having a hydroxyl group at the terminal is produced, and the molecular weight of the polyester resin (main ingredient) can be adjusted by adjusting the equivalent ratio of the isocyanate group to the hydroxyl group of the polyester. . In this invention, it is preferable to use the thing connected so that the said equivalence ratio (OH/NCO) may be 1.01-10. Moreover, as another molecular weight adjustment method, adjustment of the reaction conditions (mixing molar ratio of dicarboxylic acid and diol) of the copolymerization reaction of dicarboxylic acid and diol can be mentioned.

Epoxy resins and acrylic resins may be added as additives to the above-mentioned main ingredient (additives to the colored ink composition).

In addition, when any one or more of the limited structure mentioned as a preferable structure is employ|adopted as said polyester resin (main ingredient), there exists an advantage that more sufficient adhesive force can be ensured as a colored layer. From the viewpoint of obtaining such an effect, the preferable configuration of the above-mentioned polyester resin (main ingredient) is technically important.

As a polyfunctional isocyanate compound of the said hardening|curing agent, various polyfunctional isocyanate compounds of aromatic type, aliphatic type, and alicyclic type can be used. Specific examples include aliphatic hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), aromatic toluene diisocyanate (TDI), and diphenylmethane diisocyanate. (MDI) etc. and the polyfunctional isocyanate of 1 type or 2 or more types selected from the group of these polyfunctional isocyanate modified products. As a modification method, in addition to adducts with polyfunctional active hydrogen compounds such as water, glycerol, and trimethylolpropane, various methods such as isocyanuration, carbodiimide, and polymerization can be exemplified. The modified polyfunctional isocyanate obtained by the polymerization reaction.

50 mol% or more (50 mol% or more and 100 mol% or less) of the polyfunctional isocyanate compound as the curing agent is composed of an aromatic polyfunctional isocyanate compound. That is, 50 mol% or more is comprised with the aromatic polyfunctional isocyanate compound with respect to 100 mol% of the total amount of a polyfunctional isocyanate compound. By making 50 mol % or more of the aromatic polyfunctional isocyanate compound, the adhesive strength after curing can be increased. Therefore, even in the case of deeper molding, it can be The heat-resistant resin layer 13 is sufficiently prevented from peeling off from the colored layer 12 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 70 mol % or more of an aromatic polyfunctional isocyanate compound, and more preferably 80 mol % or more of an aromatic polyfunctional isocyanate compound.

In addition, when any one or more of the limited structures mentioned as preferable structures are employed as the above-mentioned polyfunctional isocyanate compound (curing agent), there is an advantage that a more sufficient adhesive force can be secured as a colored layer . From the viewpoint that such an effect can be obtained, the preferable configuration of the above-mentioned polyfunctional isocyanate compound (curing agent) is technically important.

In the above-mentioned two-component curable polyester urethane resin adhesive, it is preferable that the main agent curing agent is blended in a proportion of 2 to 25 moles of isocyanate functional groups (NCO) relative to 1 mole of polyol hydroxyl groups (OH). When the above molar ratio (NCO)/(OH) is less than 2 and the isocyanate functional group (NCO) is reduced, a sufficient curing reaction may not proceed, and appropriate coating film strength and heat resistance may not be obtained. On the other hand, when (NCO)/(OH) exceeds 25 and the isocyanate functional group (NCO) increases, the reaction with functional groups other than polyols proceeds excessively, the coating film becomes too hard, and an appropriate elongation cannot be obtained. possible. Particularly preferred molar ratios of polyol hydroxyl groups to isocyanate functional groups (NCO)/(OH) are 5-20.

The adhesive containing the above-mentioned two-component curable polyester urethane resin is subjected to polycondensation of dicarboxylic acid and diol as raw materials of the polyester resin, further chain extension using polyfunctional isocyanate as necessary, and the solvent and urethane are reacted Catalyst, coupling agent for improving adhesion, epoxy resin, defoaming agent, leveling agent, ultraviolet absorber, antioxidant and other additives are mixed to obtain a fluid polyester resin liquid, which is mixed with A polyfunctional isocyanate compound as a curing agent or a solvent can be further blended to prepare a low-viscosity fluid.

The solid content in the coloring composition using the above-mentioned two-component curable polyester urethane resin adhesive is a polyester resin and a colorant as the main components of the two-component curable polyester urethane resin adhesive. Therefore, the content of the colorant is set as the content rate of the colorant with respect to the total amount of the polyester resin and the colorant.

[Material of layers other than colored layers]

(Heat Resistant Resin Layer)

The heat-resistant resin layer 13 is an outer layer (substrate layer) when used as a case, and as the heat-resistant resin constituting the heat-resistant resin layer 13, it is used for a heat-resistant resin that does not melt at a heat-sealing temperature during heat-sealing. Thermal resin. As the above-mentioned heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point 10°C or more higher than the melting point of the heat-fusible resin constituting the heat-fusible resin layer 15 , and it is particularly preferable to use a melting point that is 20°C or more higher than the melting point of the heat-fusible resin. heat-resistant resin. For example, a polyamide film, a polyester film, etc. can be mentioned, and a stretched film of these films is preferably used. Among them, as the above-mentioned heat-resistant resin layer 13, from the viewpoint of formability and strength, a biaxially stretched polyamide film, a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polyamide film, a Axially stretched polyethylene terephthalate (PET) film or biaxially stretched polyethylene naphthalate (PEN) film. Although it does not specifically limit as said polyamide film, For example, a nylon 6 film, a nylon 6,6 film, a nylon MXD film, etc. are mentioned. It should be noted that the above-mentioned heat-resistant resin layer 2 may be formed of a single layer, or may be formed of a multilayer formed of, for example, a PET film/polyamide film.

It is preferable that the thickness of the said heat resistant resin layer 13 is 9 micrometers - 50 micrometers. When a polyester film is used, the thickness is preferably 9 μm to 50 μm, and when a polyamide film is used, the thickness is preferably 10 μm to 50 μm. By setting the above-mentioned preferable lower limit value or more, sufficient strength can be ensured as a packaging material, and by setting the above-mentioned preferable upper limit value or less, the stress at the time of bulging forming and deep drawing can be reduced, Formability can be improved.

Moreover, it is preferable that the said heat resistant resin layer 13 is a transparent resin from the point which can see through the colored layer 12.

(Thermal Adhesive Resin Layer)

The heat-fusible resin layer (inner layer) 15 also has excellent chemical resistance against highly corrosive electrolytes and the like used in lithium ion secondary batteries and the like, and plays a role of imparting heat-sealability to the laminate.

Although it does not specifically limit as the said heat-fusible resin layer 15, It is preferable that it is a thermoplastic resin unstretched film layer. The thermoplastic resin unstretched film layer is not particularly limited, but from the viewpoints of chemical resistance and heat sealability, it is preferably composed of an unstretched film made of polyethylene, polypropylene , olefin-based copolymers, acid-modified products of these substances, and at least one thermoplastic resin selected from the group consisting of ionomers.

It is preferable to set the thickness of the said heat-fusible resin layer 15 to 20 micrometers - 80 micrometers. By setting it to 20 micrometers or more, generation|occurrence|production of a pinhole can fully be prevented, and by setting it to 80 micrometers or less, the resin usage-amount can be reduced and cost reduction can be aimed at. Among them, it is particularly preferable to set the thickness of the heat-fusible resin layer 15 to 30 μm to 50 μm. In addition, the said heat-fusible resin layer 15 may be a single layer or a multi-layer may be sufficient as it. As the heat-fusible resin layer 15 having a multilayer structure, a three-layer film or the like in which a random polypropylene film is laminated on both surfaces of a block polypropylene film can be exemplified.

(metal foil layer)

The metal foil layer 10 described above plays a role of imparting gas barrier properties to the laminate material 1 to prevent the penetration of oxygen and moisture. Although it does not specifically limit as said metal foil layer 10, For example, aluminum foil, copper foil, stainless steel foil, etc. are mentioned, Usually, aluminum foil is used. It is preferable that the thickness of the said metal foil layer 10 is 20 micrometers - 100 micrometers. By making it 20 μm or more, it is possible to prevent the generation of pores during rolling for producing the metal foil, and by making it 100 μm or less, the stress at the time of bulging forming and deep drawing can be reduced, and the formability can be improved. .

Preferably, the metal foil layer 10 is subjected to chemical conversion treatment on at least the inner surface (surface on the second adhesive bond layer 14 side). By performing such chemical conversion treatment, corrosion of the surface of the metal foil caused by the contents (electrolyte of a battery, food, medicine, etc.) can be sufficiently prevented. For example, the chemical conversion treatment is performed on the metal foil by performing the following treatment. That is, for example, the chemical conversion treatment is carried out by applying any of the following substances to the surface of the degreasing metal foil, followed by drying:

1) Aqueous solution containing a mixture of at least one compound selected from the group consisting of phosphoric acid, chromic acid, metal salts of fluorides, and non-metallic salts of fluorides

2) At least one resin selected from the group consisting of phosphoric acid, acrylic resins, chitosan derivative resins, and phenolic resins, and at least one resin selected from the group consisting of chromic acid and chromium (III) salts Aqueous solution of a mixture of 1 compound

3) At least one resin selected from the group consisting of phosphoric acid, acrylic resin, chitosan derivative resin, and phenolic resin, and at least one resin selected from the group consisting of chromic acid and chromium (III) salts. An aqueous solution of a mixture of a compound and at least one compound selected from the group consisting of a metal salt of fluoride and a non-metallic salt of fluoride.

(1st adhesive bond layer)

The first adhesive layer 11 is a layer responsible for bonding the metal foil layer 10 and the heat-resistant resin layer 13, and is a layer after the metal foil layer 10 and the colored layer 12 are laminated in the production process of the laminate material 1. The bonded layer of the heat-resistant resin layer 13 . Although it does not specifically limit as the said 1st adhesive bond layer 11, For example, the adhesive bond layer etc. which consist of a two-component curable adhesive agent are mentioned. Examples of the above-mentioned two-liquid curable adhesive include, for example, a two-liquid curable adhesive composed of a first liquid and a second liquid (hardening agent) containing an isocyanate, wherein the first liquid contains a resin made from polyurethane One or more polyols selected from the group consisting of polyols, polyester polyols, polyether polyols, and polyester polyurethane polyols. Among them, it is preferable to use a two-liquid curable adhesive composed of a first liquid containing a polyester-based polyol and a polyester polyurethane-based polyol and a second liquid (hardening agent) containing an isocyanate. One or two or more kinds of polyols selected from the group consisting of. The above-mentioned first adhesive layer 11 applies an adhesive such as the above-mentioned two-component curable adhesive to the upper surface of the above-mentioned metal foil layer 10 and/or the above-mentioned heat-resistant resin layer 13 by a method such as a gravure coating method. the lower surface (for example, the lower surface of the colored layer 12) is formed.

The bonding method of the metal foil layer 10 and the heat-resistant resin layer 13 (heat-resistant resin layer on which the colored layer 12 is laminated) is not particularly limited, and a so-called dry lamination method can be recommended. Specifically, the prepared first surface is applied to the upper surface of the metal foil layer 10 or the lower surface of the heat-resistant resin layer 13 (in the above-described embodiment, the lower surface of the colored layer 12 ), or to both surfaces. The adhesive is formed into a dry film by evaporating the solvent, and the metal foil layer 10 and the heat-resistant resin layer 13 are bonded together. After that, it is cured according to the curing conditions of the first adhesive. Thereby, the metal foil layer 10 and the heat-resistant resin layer 13 on which the colored layer 12 is laminated|stacked are joined via the 1st adhesive bond layer 11. In addition, as a coating method of a 1st adhesive agent, a gravure coating method, a reverse roll coating method, a lip roll coating method, etc. can be illustrated.

(2nd adhesive bond layer)

It does not specifically limit as the said 2nd adhesive bond layer 14, For example, a urethane type adhesive agent, an acrylic type adhesive agent, an epoxy type adhesive agent, a polyolefin type adhesive agent, an elastomer type adhesive agent can be mentioned. Adhesive layer formed of adhesives, fluorine-based adhesives, acid-modified polypropylene adhesives, etc. Among them, an acrylic adhesive and a polyolefin-based adhesive are preferably used, and in this case, the electrolyte solution resistance and the water vapor barrier properties of the laminate 1 can be improved.

The bonding method of the metal foil layer 10 and the thermoplastic resin layer 15 is not particularly limited, and, as with the bonding of the metal foil layer 10 and the heat-resistant resin layer 13, it can be exemplified by applying a second adhesive and A dry lamination method in which the metal foil layer 10 and the heat-fusible resin layer 15 are bonded together after drying.

[Other ways of laminating material]

The laminate 1 of the present invention is not particularly limited to the laminate structure shown in FIG. 1 , and further layers can be added to form a packaging material to improve functions. For example, a laminate in which a matte coating layer is formed on the outer surface of the heat-resistant resin layer 13 (the surface on the opposite side to the colored layer 12 ) can be exemplified.

The above-mentioned matte coating layer is a surface layer provided for imparting good sliding properties to the surface of the laminate 1 and improving moldability. By providing this light coat layer, slippage between the heat-resistant resin layer and the colored layer is less likely to occur during molding or the like, and the heat-resistant resin layer is less likely to be peeled from the coloring.

The above-mentioned matte coating layer is a layer formed by dispersing a resin composition containing inorganic fine particles in a heat-resistant resin component. Among them, it is preferable that the above-mentioned matte coating layer is formed of a resin composition containing 0.1% by mass to 1% by mass of inorganic fine particles having an average particle diameter of 0.1 μm to 10 μm in a two-component curable heat-resistant resin. Examples of the above-mentioned heat-resistant resins include acrylic resins, epoxy-based resins, polyester-based resins, urethane-based resins, polyolefin-based resins, fluorine-based resins, phenoxy-based resins, and the like. From the viewpoint of being excellent in chemical resistance, a fluorine-based resin based on tetrafluoroethylene or vinyl fluoride-vinyl ether is preferably used. The inorganic fine particles are not particularly limited, and examples thereof include silica, alumina, calcium oxide, calcium carbonate, calcium sulfate, and calcium silicate. Among them, silica is preferably used.

The formation of the above-mentioned matte coating layer can be performed by applying a matte coating composition containing the above-mentioned inorganic fine particles and a heat-resistant resin to the surface of the above-mentioned heat-resistant resin layer 13 and curing it.

The thickness of the above-mentioned matte coating layer (thickness after curing) is preferably 0.5 μm to 5 μm. By making it more than the said preferable lower limit value, the slidability improvement effect can fully be acquired, and by making it less than the said preferable upper limit value, cost can be suppressed. Among them, the thickness (thickness after curing) of the above-mentioned matte coating layer is particularly preferably 1 μm to 3 μm.

The gloss value of the surface of the above-mentioned matte coating layer is preferably set to 1% to 15% in terms of a 60° reflection angle measurement value based on JIS Z8741. The above-mentioned gloss value is a value measured at a reflection angle of 60° with a gloss meter "micro-TRI-gloss-s" manufactured by BYK Corporation.

In addition, the implementation period (implementation order) of the process of forming the above-mentioned matte coating layer is not particularly limited, but is preferably the same as the process of laminating the heat-resistant resin layer 13 on which the colored layer 12 is laminated to the metal foil layer 10 proceed successively.

In addition, in the above-mentioned embodiment, the configuration in which the first adhesive layer 11 and the second adhesive layer 14 are provided is adopted, but both the layers 11 and 14 are not necessarily constitutive layers, and may be adopted without the composition of the two. In addition, the adhesiveness with the metal foil layer 10 can be improved by providing the above-mentioned adhesive bond layers 11 and 14. In particular, it is preferable to use an adhesive containing the same resin component as the resin adhesive of the second layer 12b of the colored layer 12 for the first adhesive layer 11, so that the second layer 12b can be more difficult to peel.

Moreover, you may exist between the said heat-resistant resin layer 13 and the colored layer 12, the easy-adhesion layer which does not contain a colorant may exist.

The laminated material 1 of this invention is not limited to the material manufactured using the manufacturing method exemplified above, including the bonding method of each layer, etc., and the material manufactured using other manufacturing methods is also included in this invention.

The laminated material of the present invention can be cut to a desired size or molded (deep-drawing, bulging, etc.) as required, so that a molded case such as an outer package for a battery can be produced. The battery exterior body is formed with a battery element chamber for accommodating the battery element by aligning the laminate material so that the heat-fusible resin layers face inwards, and heat-sealing the edge portion. Since the heat-resistant resin layer of the laminated material of the present invention is not easily peeled off, the heat-resistant resin layer is not easily removed even when a battery in which the laminated material is used as an outer casing for a battery is used in a slightly severe environment such as high temperature and high humidity. No local cracking and peeling.

Moreover, although the laminated material of this invention is preferably used as a packaging material for lithium ion secondary battery cases, it is not limited to such a use in particular.

Example

Next, the specific Example of this invention is demonstrated. It should be noted that the present invention is not particularly limited to this embodiment.

[Preparation of Laminate]

In the following Examples 1 to 11 and Comparative Example 2, the laminated material 1 of the laminated structure shown in FIG. 1 was prepared. These examples have the colored layer 12 having a two-layer structure. In addition, as Comparative Example 1, a laminate (not shown) having a single-layer colored layer was prepared. These laminates differ only in the structure and composition of the coloring layer, and are common to other materials. Common materials are as follows.

(common material)

The metal foil layer 10 is an aluminum foil made of A8079-O of JIS H4160 with a thickness of 35 μm, and a chemical conversion treatment liquid composed of polyacrylic acid, trivalent chromium compound, water, and alcohol is applied to both surfaces of the aluminum foil, and dried at 150° C. A chemical conversion coating is formed. The chromium adhesion amount based on this chemical conversion coating was 50 mg/m ² per single side.

The heat-resistant resin layer 13 as an outer layer is a biaxially stretched nylon film with a thickness of 15 μm, and the heat-fusible resin layer 15 as an inner layer is a non-stretched polypropylene film with a thickness of 30 μm. Moreover, as the 1st adhesive bond layer 11, a two-component curable polyester urethane resin adhesive was used, and for the 2nd adhesive bond layer 14, a polyacrylic acid adhesive was used.

As the colorant, carbon black having an average particle diameter of 0.2 μm was used.

(Examples 1 to 3, 8 to 11, Comparative Example 2)

The first coloring composition constituting the first layer 12a of the colored layer 12 and the second coloring composition constituting the second layer 12a are compositions in which a colorant is dispersed in a two-component curable polyester urethane resin adhesive. In each example, the resin binders of the first coloring composition and the second coloring composition are common, and only the content rate of the colorant is different.

First, a polyester resin (polyester polyol) as the main ingredient of the resin binder is prepared. 30 mol parts of neopentyl glycol, 30 mol parts of ethylene glycol, and 40 mol parts of 1,6-hexanediol were melted at 80° C., and 30 mol parts of aliphatic dicarboxylic acid containing 30 mol parts of the mixture was melted while stirring. A polycondensation reaction of adipic acid and 70 mole parts of a dicarboxylic acid mixture of isophthalic acid, which is an aromatic dicarboxylic acid, was carried out at 210° C. for 20 hours to obtain a polyester polyol (polyester resin) as the main ingredient. The polyester polyol had a number-average molecular weight (Mn) of 12,000, a weight-average molecular weight (Mw) of 20,500, and a ratio (Mw/Mn) of the two of 1.71. Further, 60 parts by mass of ethyl acetate was added to 40 parts by mass of the polyester polyol obtained above to prepare 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, after mixing 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, the colorants shown in Table 1 were obtained using a pigment disperser. The colorant in the amount of the content rate was dispersed to prepare the main ingredient composition for the first layer and the main ingredient composition for the second layer.

7.1 parts by mass of an adduct of toluene diisocyanate (TDI) and trimethylolpropane (NCO%: 13.0%, solid content: 75 mass %; aromatic polyfunctional isocyanate compound), and 34.1 mass parts of ethyl acetate were mix|blended and stirred, and the 1st coloring composition was produced. Similarly, a 2nd coloring composition was prepared by mixing and stirring the said main ingredient composition for 2nd layers and the said hardening|curing agent. The molar ratio (NCO/OH) of the isocyanate functional group (NCO) to the hydroxyl group (OH) of the polyester polyol was 10 in the above-mentioned first coloring composition and the second coloring composition.

Next, the first layer 12a of the colored layer 12 is formed by applying and drying the above-mentioned first coloring composition on one surface of the heat-resistant resin layer 13 . Next, the 2nd layer 12b of the colored layer 12 is formed by apply|coating and drying the 2nd coloring composition on the said 1st layer 12a. Thereby, the colored layer 12 of the two-layer structure is formed on one surface of the heat-resistant resin layer 13 . Table 1 shows the film thickness after drying of the first layer 12a and the second layer and the adhesion amount of the colorant.

Next, an adhesive is applied to one surface of the metal foil layer 10 after the chemical conversion coating has been formed on both surfaces, and it is dried to form a first adhesive layer 11 on which the first adhesive layer 11 is formed. The surface of the metal foil layer 10 is bonded to the colored layer 12 side of the above-mentioned heat-resistant resin layer 13, and an adhesive is applied to the other surface of the metal foil layer 10 and dried to form the second adhesive layer 14. 2. The surface of the adhesive bond layer 14 is bonded to the thermally fusible resin layer 15. This laminated body was left to stand in a 40 degreeC environment for 5 days, and the laminated material 1 of the structure shown in FIG. 1 was produced.

(Example 4)

Laminated material 1 was prepared using the same materials and the same method as in Example 1, except that acrylic urethane was used as the resin binder of the first layer 12a of the colored layer 12 to prepare the first colored composition.

Number-average molecular weight (Mn), weight-average molecular weight (Mw), ratio (Mw/Mn) of the above-mentioned acrylic urethane, content rate of colorant in the above-mentioned first coloring composition, first layer 12a and second layer Table 1 shows the film thickness after drying of 12b and the adhesion amount of the colorant.

(Example 5)

Laminated material 1 was prepared using the same materials and the same method as in Example 1, except that polyurethane was used as the resin binder for the first layer 12a of the colored layer 12 to prepare the first colored composition.

Number-average molecular weight (Mn), weight-average molecular weight (Mw), ratio (Mw/Mn) of said polyurethane, content rate of colorant in said first coloring composition, first layer 12a and second layer 12b The film thickness after drying and the adhesion amount of the colorant are shown in Table 1.

(Example 6)

The number average molecular weight (Mn) was obtained by changing the molar ratio and reaction conditions of the total amount of diol components to the total amount of dicarboxylic acid in Example 1 using the same starting materials as in Example 1 above. ) is 8900, the weight average molecular weight (Mw) is 13000, and the ratio (Mw/Mn) of the two is a polyester polyol of 1.46.

Next, the first coloring composition and the second coloring composition were prepared by the same method as in Example 1, the coloring layer 12 having a two-layer structure was formed on one surface of the heat-resistant resin layer 13, and the coloring layer 12 was prepared together with other materials. A laminate having the configuration shown in FIG. 1 was obtained. The molar ratio (NCO/OH) of the isocyanate functional group (NCO) to the polyester polyol hydroxyl group (OH) is 10 in the first coloring composition and the second coloring composition. In addition, the content rate of the colorant in the said 1st coloring composition and the 2nd coloring composition, the film thickness after drying of the 1st layer 12a and the 2nd layer 12b, and the adhesion amount of the colorant are shown in Table 1.

(Example 7)

The number average molecular weight (Mn) was obtained by changing the molar ratio and reaction conditions of the total amount of diol components to the total amount of dicarboxylic acid in Example 1 using the same starting materials as in Example 1 above. ) is 2100, the weight average molecular weight (Mw) is 43000, and the ratio (Mw/Mn) of the two is a polyester polyol of 2.05.

Next, the first coloring composition and the second coloring composition were prepared by the same method as in Example 1, the coloring layer 12 having a two-layer structure was formed on one surface of the heat-resistant resin layer 13, and the coloring layer 12 was prepared together with other materials. A laminate having the configuration shown in FIG. 1 was obtained. The molar ratio (NCO/OH) of the isocyanate functional group (NCO) to the polyester polyol hydroxyl group (OH) is 10 in the first coloring composition and the second coloring composition. In addition, the content rate of the colorant in the said 1st coloring composition and the 2nd coloring composition, the film thickness after drying of the 1st layer 12a and the 2nd layer 12b, and the adhesion amount of the colorant are shown in Table 1.

(Comparative Example 1)

A laminate was prepared in the same manner as in Example 1, except that the colored layer was formed as a single layer having the same composition and thickness as the second layer 12b of Example 1.

【Table 1】

Each of the laminates produced in the above-described manner was evaluated based on the following evaluation method. The results are shown in Table 2.

(coloring)

Using a spectrophotometer (CM2500C manufactured by Konica Minolta), the L value of the surface of the heat-resistant resin layer of the laminate was measured for color. When the measured L value was less than 50, it was judged as 0 (good coloration), and when 50 or more was judged as × (poor coloration).

(with or without peeling)

Using a punch, a die, or the like, deep-drawing to form the convex portion 31 of 33 mm in length x 54 mm in width x 4.0 mm in depth is performed for each laminate material so that the inner heat-fusible resin layer 15 is brought into contact with the punch, to prepare The test material 30 having the shape of a flat flange around the convex portion 31 (see FIG. 2 ).

The top surface 32 of the convex portion 31 of the test material 30 was crushed, and the crushed test material 30 was subjected to a high-temperature and high-humidity test and a warm water immersion test to investigate whether the heat-resistant resin layer 13 was peeled off.

In the high temperature and high humidity test, the crushed test material 30 was kept for 2 weeks in an atmosphere with a temperature of 70° C. and a humidity of 90%. Then, the material with no peeling of the heat-resistant resin layer was judged as 0, and the material with peeling was judged as x.

In the warm water immersion test, the crushed test material 30 was immersed in warm water at 45°C and kept for 2 weeks. Then, the material in which the heat-resistant resin layer was not peeled was determined as 0, the material in which the extremely fine peeling occurred was determined as 0, and the material in which the peeled off was determined as x.

【Table 2】

From Tables 1 and 2, it was confirmed that stability was obtained by setting the coloring layer to have a two-layer structure and setting the colorant content of the first layer in contact with the heat-resistant resin layer to be lower than that of the second layer. The color development state can be suppressed and the peeling of the heat-resistant resin layer can be suppressed.

Industrial Availability

The laminated material of the present invention is preferably used as a casing for batteries such as notebook computers, mobile phones, vehicles, stationary lithium ion polymer secondary batteries, etc., and is also preferably used as a packaging material for food, pharmaceuticals, etc. Packaging materials for products, but are not particularly limited to these uses. Among them, it is particularly preferable for use as a battery case.

Claims (5)

1. A laminate comprising: a heat-resistant resin layer as an outer layer; a heat-fusible resin layer as an inner layer; a metal foil layer disposed between the two layers; and a colored layer disposed on the metal Between the foil layer and the heat-resistant resin layer, the laminate is characterized by: The colored layer is formed of a colored composition containing a resin binder and a colorant, and the colored layer is a multilayer formed by laminating two or more layers having different contents of the colorant, and is formed with the heat-resistant resin. The content rate of the colorant in the layer in which the layers are in contact is lower than the content rate in the other layers. 2 . The laminate according to claim 1 , wherein the coloring composition of each layer of the coloring layer contains a common resin binder. 3 . 3 . The laminate according to claim 1 , wherein an adhesive layer is disposed between the colored layer and the metal foil layer, and a resin component contained in the adhesive layer and a resin component constituting the colored layer are disposed. 4 . The resin binder of the coloring composition is the same. 4 . The laminate according to claim 1 , wherein a protective layer containing a resin component and a filler component is laminated on the outer side of the heat-resistant resin layer. 5 . 5 . An outer package for a battery, characterized by heat-sealing the merging edge portions of the laminate according to claim 1 such that the heat-fusible resin layers face inwards. , thereby forming a battery element chamber for accommodating battery elements.

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