JP6818533B2 - Adhesive sheet for batteries, manufacturing method of adhesive sheet for batteries and lithium ion battery - Google Patents

Description

The present invention relates to an adhesive sheet for a battery, a method for producing an adhesive sheet for a battery, and a lithium ion battery produced by using them.

In some batteries, a strip-shaped laminate in which a positive electrode, a negative electrode, and a separator located between them are laminated is housed inside in a wound state. An electrode take-out tab made of a conductor is connected to each of the positive electrode and the negative electrode, and the positive electrode and the negative electrode are electrically connected to the positive electrode terminal and the negative electrode terminal of the battery, respectively, via these electrode take-out tabs. ..

Adhesive tape is used for winding the laminate and fixing the electrode take-out tab to the electrode. Patent Document 1 discloses such an adhesive tape. These adhesive tapes consist of a base material and an adhesive layer provided on one surface of the base material.

Japanese Unexamined Patent Publication No. 2011-138632

The adhesive tape used inside the battery may come into contact with the electrolytic solution filled inside the battery, or may be exposed to heat generated during charging / discharging or the like. Particularly in recent years, the development of small and high-performance batteries has been promoted, and the adhesive tape used inside the batteries is exposed to more severe conditions.

In order to exhibit the performance as a battery, the adhesive tape is required to exhibit good adhesive force to the adherend even when exposed to the severe conditions as described above. Further, the adhesive tape itself is also required to maintain high adhesion between the base material and the pressure-sensitive adhesive layer. However, conventional adhesive tapes may not be able to sufficiently meet such requirements.

The present invention has been made in view of such an actual situation, and even when the adhesive sheet for a battery comes into contact with an electrolytic solution, it exhibits good adhesive force to an adherend and is a base material. It is an object of the present invention to provide an adhesive sheet for a battery and a lithium ion battery having excellent adhesion between the adhesive layer and the adhesive layer, and a method for producing the adhesive sheet for a battery.

In order to achieve the above object, firstly, in the present invention, the base material, the hard coat layer provided on one surface side of the base material, and the surface side of the hard coat layer opposite to the base material. Provided is a pressure-sensitive adhesive sheet for a battery, which comprises the pressure-sensitive adhesive layer provided in the above, wherein the hard coat layer is formed from a composition for a hard coat layer containing a heat-crosslinking agent (invention). 1). In this specification, the sheet also includes the concept of tape. Further, the hard coat layer in the present specification means a layer made of a material harder than the base material, and does not mean a layer existing on the outermost layer of the film.

According to the above invention (Invention 1), the hard coat layer is provided between the base material and the pressure-sensitive adhesive layer, so that the hard coat layer is the electrolytic solution even when the pressure-sensitive adhesive sheet comes into contact with the electrolytic solution. It blocks permeation and makes it difficult for the electrolytic solution to penetrate into the adhesive layer. As a result, the pressure-sensitive adhesive layer exhibits good adhesive strength to the adherend. Further, according to the above invention (Invention 1), the hard coat layer is formed from the composition for the hard coat layer containing the heat cross-linking agent, and the action of the heat-crosslinking agent or the component derived from the heat-crosslinking agent causes the hard coat layer. The adhesion between the hard coat layer and the pressure-sensitive adhesive layer and the adhesion between the hard coat layer and the base material are improved, so that the adhesion between the base material and the pressure-sensitive adhesive layer is excellent.

In the above invention (Invention 1), it is preferable that the thermal cross-linking agent is an isocyanate-based cross-linking agent (Invention 2).

In the above inventions (Inventions 1 and 2), it is preferable that the composition for the hard coat layer contains the thermal cross-linking agent, an active energy ray-curable component, and an inorganic filler (Invention 3).

In the above inventions (Inventions 1 to 3), it is preferable that the base material is a film made of a polymer having a nitrogen-containing ring structure in the main chain (Invention 4).

In the above inventions (Inventions 1 to 4), it is preferable that the pressure-sensitive adhesive layer is formed from a pressure-sensitive composition containing a (meth) acrylic acid ester polymer (Invention 5).

Secondly, in the present invention, the base material, the hard coat layer provided on one surface side of the base material, and the pressure-sensitive adhesive layer provided on the surface of the hard coat layer opposite to the base material are provided. A method for producing an adhesive sheet for a battery, which is applied to a coating film of a composition for a hard coat layer containing at least an active energy ray-curable component and a thermal cross-linking agent applied to one surface side of a base material. For batteries, the hard coat layer formed by irradiating with a line and the coating film of the adhesive composition are laminated and then cured to form an adhesive layer in close contact with the hard coat layer. Provided is a method for producing an adhesive sheet (Invention 6).

Thirdly, the present invention is characterized in that two or more conductors are fixed in contact with each other inside the battery by using the battery adhesive sheet (Invention 1 to 5). An ion battery is provided (Invention 7).

According to the battery adhesive sheet and the lithium ion battery according to the present invention, even when the battery adhesive sheet comes into contact with the electrolytic solution, it exhibits good adhesive force to the adherend and is used with the base material. Excellent adhesion to the pressure-sensitive adhesive layer. Further, according to the method for producing an adhesive sheet for a battery according to the present invention, even when it comes into contact with an electrolytic solution, it exhibits good adhesive force to an adherend, and the base material and the adhesive layer It is possible to manufacture an adhesive sheet for a battery having excellent adhesion between the two.

It is sectional drawing of the adhesive sheet for a battery which concerns on one Embodiment of this invention. It is a partial cross-sectional exploded perspective view of the lithium ion battery which concerns on one Embodiment of this invention. It is a developed perspective view of the electrode body of the lithium ion battery which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Adhesive sheet for batteries]
As shown in FIG. 1, the battery adhesive sheet 1 according to the embodiment of the present invention includes a base material 11, a hard coat layer 12 provided on one surface side of the base material 11, and a hard coat layer 12. It is composed of a pressure-sensitive adhesive layer 13 provided on the side opposite to the base material 11 and a release sheet 14 provided on the side opposite to the hard coat layer 12 in the pressure-sensitive adhesive layer 13.

Here, the "adhesive sheet for a battery" in the present specification is an adhesive sheet used in a place where it may come into contact with an electrolytic solution in the manufacture of a battery, and is preferably an adhesive sheet used inside the battery. It may be an adhesive sheet for battery interior. The battery is preferably a non-aqueous battery. Therefore, the electrolytic solution of the battery is preferably a non-aqueous electrolytic solution. The adhesive sheet for batteries in the present specification is preferably an adhesive sheet to be attached to a portion of the non-aqueous battery that may be immersed in the electrolytic solution or a portion that may come into contact with the electrolytic solution. As the non-aqueous battery, a lithium ion battery is particularly preferable.

According to the battery adhesive sheet 1 according to the present embodiment, the electrolytic solution that has penetrated into the base material 11 is blocked by the hard coat layer 12, so that the electrolytic solution permeates the hard coat layer 12 and reaches the adhesive layer 13. Is presumed to be suppressed. It is estimated that this reduces the amount of electrolytic solution that penetrates into the pressure-sensitive adhesive layer 13.

Even if the hard coat layer 12 is laminated not between the base material 11 and the pressure-sensitive adhesive layer 13 but on the surface of the base material 11 opposite to the pressure-sensitive adhesive layer 13, the electrolytic solution can penetrate. Can be expected to some extent. However, even with such a configuration, it is presumed that the electrolytic solution infiltrated from the end portion of the base material 11 reaches the pressure-sensitive adhesive layer 13 in contact with the base material 11 via the inside of the base material 11. To. Some of the materials of the base material 11 that are generally used have extremely high permeability of the electrolytic solution, and when such a material is used, a predetermined amount of the electrolytic solution is applied to the base material even from only the end portion. It is presumed that it penetrates into 11 and then into the pressure-sensitive adhesive layer 13.

On the other hand, in the battery adhesive sheet 1 according to the present embodiment, by providing the hard coat layer 12 between the base material 11 and the pressure-sensitive adhesive layer 13, only the electrolytic solution that penetrates into the base material 11 from the main surface can be used. It is presumed that the electrolytic solution that penetrates into the base material 11 from the end is also blocked by the hard coat layer 12, so that it is suppressed from reaching the pressure-sensitive adhesive layer 13.

As described above, in the adhesive sheet 1 for batteries according to the present embodiment, the adhesive strength is maintained good by reducing the amount of the electrolytic solution that penetrates into the adhesive layer 13, and the adhesive sheet 1 is released from the adherend. Peeling is suppressed, and the amount of components of the pressure-sensitive adhesive layer 13 eluted in the electrolytic solution is reduced.

Further, the hard coat layer 12 of the battery adhesive sheet 1 according to the present embodiment is formed from a composition for a hard coat layer containing a heat cross-linking agent, and contains a heat-crosslinking agent or a component derived from the heat-crosslinking agent. contains. By the action of the heat-crosslinking agent or the component derived from the heat-crosslinking agent, the adhesion between the hard coat layer 12 and the pressure-sensitive adhesive layer 13 and the adhesion between the hard coat layer 12 and the base material 11 are improved. In particular, since the heat-crosslinking agent in the hard coat layer 12 easily reacts with the reactive functional groups of the pressure-sensitive adhesive base in the pressure-sensitive adhesive layer 13, the adhesiveness between the layers is likely to be improved. Then, even when the battery adhesive sheet 1 comes into contact with the electrolytic solution, high adhesion is maintained between the hard coat layer 12 and the adhesive layer 13 and between the hard coat layer 12 and the base material 11. As a result, the adhesion between the base material 11 and the pressure-sensitive adhesive layer 13 is excellent. As a result, in the battery manufactured by using the battery pressure-sensitive adhesive sheet 1, peeling between the base material 11 and the pressure-sensitive adhesive layer 13 is suppressed.

Further, the battery adhesive sheet 1 according to the present embodiment is provided with the hard coat layer 12, so that the insulating property can be ensured even when the base material 11 and the adhesive layer 13 are carbonized, and the battery The safety of the battery can be improved.

In the battery using the adhesive sheet 1 for a battery according to the present embodiment having the above-mentioned effects, deterioration of performance due to the adhesive sheet is suppressed, malfunction, thermal runaway and short circuit of the battery are suppressed, and the battery Improves reliability.

1. 1. Each component 1-1. Base material In the battery adhesive sheet 1 according to the present embodiment, the base material 11 preferably has a flame retardancy that satisfies the flame retardancy level V-0 of the UL94 standard. Since the base material 11 has such flame retardancy, denaturation and deformation of the base material 11 are suppressed even when heat is generated by using a normal battery. Further, even if a problem occurs in the battery and excessive heat generation occurs, ignition and combustion of the base material 11 are suppressed, and a serious accident is prevented.

The material of the base material 11 can be appropriately selected from the viewpoints of adhesion to the hard coat layer 12, flame retardancy, heat resistance, insulating property, reactivity with the electrolytic solution, permeability of the electrolytic solution, and the like. In particular, it is preferable to use a resin film as the base material 11. Examples of the resin film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyolefin films such as polyethylene film and polypropylene film, polyamide films, polyimide films, polyamideimide films, and the like containing nitrogen in the main chain. Combined film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film , Polymethylpentene film, polysulphon film, polyether ether ketone film, polyether sulfone film, polyetherimide film, fluororesin film, acrylic resin film, polyurethane resin film, norbornene-based polymer film, cyclic olefin-based polymer film , A resin film such as a cyclic conjugated diene polymer film, a vinyl alicyclic hydrocarbon polymer film, or a laminated film thereof. Among the above, a film made of a polymer containing nitrogen in the main chain is preferable, a film made of a polymer having a nitrogen-containing ring structure in the main chain is particularly preferable, and further, a nitrogen-containing ring structure and an aromatic ring structure in the main chain are preferable. A film made of a polymer having the above is preferable. Specifically, a polyimide film and a polyamide-imide film are preferable, and a polyimide film is particularly preferable. In a film made of a polymer having a nitrogen-containing ring structure in the main chain, the nitrogen-containing ring is cleaved and a reaction of adding a thermal cross-linking agent (particularly an isocyanate-based cross-linking agent) in the hard coat layer 12 is likely to occur. The adhesion to the coat layer 12 becomes higher. Among the above, the polyimide film is particularly excellent in adhesion to the hard coat layer 12 and also excellent in flame retardancy.

The thickness of the base material 11 is preferably 5 to 200 μm, particularly preferably 10 to 100 μm, and further preferably 15 to 40 μm. When the thickness of the base material 11 is 5 μm or more, appropriate rigidity is imparted to the base material 11, and even when curing shrinkage occurs when the hard coat layer 12 is formed on the base material 11, the curl Occurrence is effectively suppressed. Further, since the thickness of the base material 11 is 200 μm or less, the adhesive sheet 1 for a battery has appropriate flexibility, and is on a surface having a step as in the case of fixing an electrode and an electrode take-out tab. Even when the battery adhesive sheet 1 is attached, it is possible to follow the step well.

1-2. Hard Coat Layer (1) Composition of Hard Coat Layer The hard coat layer 12 of the battery adhesive sheet 1 according to the present embodiment is formed from a composition for a hard coat layer containing a heat-crosslinking agent. In other words, the hard coat layer 12 of the battery adhesive sheet 1 according to the present embodiment contains a thermal cross-linking agent or a component derived from the thermal cross-linking agent. As described above, the hard coat layer 12 is in contact with the pressure-sensitive adhesive layer 13 even when the battery pressure-sensitive adhesive sheet 1 comes into contact with the electrolytic solution due to the action of the heat-crosslinking agent or the component derived from the heat-crosslinking agent. And high adhesion to the base material 11 can be exhibited.

The hard coat layer 12 is preferably cured by irradiation with active energy rays. Therefore, the composition for the hard coat layer for forming the hard coat layer 12 preferably contains an active energy ray-curable component and a heat-crosslinking agent, and in particular, the active energy ray-curable component and heat-crosslinking. It is preferable to contain an agent and an inorganic filler.

(1-1) Active energy ray-curable component The active energy ray-curable component is not particularly limited as long as it is cured by irradiation with active energy rays and exhibits a desired hardness.

Specific examples of the active energy ray-curable component include a polyfunctional (meth) acrylate-based monomer and a (meth) acrylate-based prepolymer. Among them, a polyfunctional (meth) acrylate-based monomer and / or (meth) ) An acrylate-based prepolymer is preferable. The polyfunctional (meth) acrylate-based monomer and the (meth) acrylate-based prepolymer may be used alone or in combination of both. In addition, in this specification, (meth) acrylate means both acrylate and methacrylate. The same applies to other similar terms.

Examples of the polyfunctional (meth) acrylate-based monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and polyethylene glycol di. (Meta) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, dicyclopentanyl di (meth) acrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified di (meth) acrylate of phosphate, allylated Cyclohexyldi (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropantri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate ) Acrylate, propylene oxide modified trimethylolpropantri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol Examples thereof include polyfunctional (meth) acrylates such as hexa (meth) acrylates. These may be used individually by 1 type, and may be used in combination of 2 or more type. The polyfunctional (meth) acrylate-based monomer is not particularly limited, but is more preferably having a molecular weight of less than 1000 from the viewpoint of preventing the inorganic filler from coming out from the hard coat layer 12 under immersion in the electrolytic solution.

On the other hand, examples of the (meth) acrylate-based prepolymer include polyester acrylate-based, epoxy acrylate-based, urethane acrylate-based, and polyol acrylate-based prepolymers. One type of prepolymer may be used alone, or two or more types may be used in combination.

The active energy ray-curable component constituting the hard coat layer 12 of the present embodiment preferably has a glass transition point of 130 ° C. or higher after curing, more preferably 150 ° C. or higher, and the glass transition point is observed. It is particularly preferable that it is not used. Since the glass transition point of the active energy ray-curable component is as described above, the heat resistance of the hard coat layer 12 becomes excellent, and the battery adhesive sheet 1 provided with such a hard coat layer 12 is included. The performance and safety of the battery will also be excellent.

When two or more types of active energy ray-curable components are used in the hard coat layer 12 of the present embodiment, it is preferable that the active energy ray-curable components have excellent compatibility with each other.

(1-2) Thermal cross-linking agent Examples of the thermal cross-linking agent include isocyanate-based cross-linking agent, epoxy-based cross-linking agent, amine-based cross-linking agent, melamine-based cross-linking agent, aziridine-based cross-linking agent, hydrazine-based cross-linking agent, and aldehyde-based cross-linking agent. , Oxazoline-based cross-linking agent, metal alkoxide-based cross-linking agent, metal chelate-based cross-linking agent, metal salt-based cross-linking agent, ammonium salt-based cross-linking agent and the like. Among these, it is preferable to use an isocyanate-based cross-linking agent from the viewpoint of being more excellent in adhesion to the pressure-sensitive adhesive layer 13 and the base material 11. The heat cross-linking agent may be used alone or in combination of two or more.

The isocyanate-based cross-linking agent contains at least a polyisocyanate compound. Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanates, and alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate. , And their biurets, isocyanurates, and adducts, which are reactants with low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Of these, trimethylolpropane-modified aliphatic polyisocyanate is preferable, and trimethylolpropane-modified hexamethylene diisocyanate is particularly preferable, from the viewpoint of adhesion to the pressure-sensitive adhesive layer 13 and the base material 11.

The content of the heat-crosslinking agent in the composition for the hard coat layer is preferably 1 part by mass or more, more preferably 5 parts by mass or more, based on 100 parts by mass of the active energy ray-curable component. In particular, it is preferably 10 parts by mass or more, and more preferably 20 parts by mass or more. The content is preferably 90 parts by mass or less, particularly preferably 50 parts by mass or less, and further preferably 30 parts by mass or less. When the content of the thermal cross-linking agent is in the above range, the adhesion to the pressure-sensitive adhesive layer 13 and the base material 11 becomes more excellent.

(1-3) Inorganic Filler The composition for the hard coat layer constituting the hard coat layer 12 of the present embodiment preferably contains an inorganic filler. By containing the inorganic filler, the hard coat layer 12 of the present embodiment is imparted with rigidity, and the battery adhesive sheet 1 is torn or punctured due to an impact at a high temperature or under immersion in an electrolytic solution. Can be prevented.

Preferred inorganic fillers include powders of silica, alumina, boehmite, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride, zirconium oxide and the like, spherical beads, single crystal fibers and glass fibers. These can be used alone or in admixture of two or more. Among these, silica, alumina, boehmite, titanium oxide, zirconium oxide and the like are preferable, and silica, alumina and zirconium oxide are particularly preferable from the viewpoint of dispersibility in the active energy ray-curable component. In addition, these inorganic fillers can also be used in the form of a sol dispersed in a dispersion medium.

It is also preferable that the inorganic filler is surface-modified. Reactive silica can be exemplified as such an inorganic filler.

As used herein, the term "reactive silica" refers to silica fine particles surface-modified with an organic compound having an active energy ray-curable unsaturated group. The silica fine particles (reactive silica) surface-modified with an organic compound having an active energy ray-curable unsaturated group are usually composed of, for example, a silanol group on the surface of silica fine particles having an average particle size of 1 to 200 nm, and the silanol group. It can be obtained by reacting an active energy ray-curable unsaturated group-containing organic compound having a reactive functional group (for example, an isocyanate group, an epoxy group, a carboxy group, etc.). As the active energy ray-curable unsaturated group, a (meth) acryloyl group or a vinyl group can be preferably mentioned.

As an organic-inorganic hybrid material (organosilica sol) containing such a reactive silica and the above-mentioned polyfunctional (meth) acrylate-based monomer and / or (meth) acrylate-based prepolymer, for example, the trade name "Opstar Z7530". , "Opstar Z7524", "Opstar TU4086", "Opstar Z7537" (all manufactured by JSR Corporation) and the like can be used.

Other examples of preferred inorganic fillers include alumina ceramic nanoparticles, silica sol in which silica fine particles with exposed silanol groups on the silica surface are suspended in a colloidal state in a dispersion medium, and silanol groups on the silica surface are silane coupling. Examples thereof include organosilica sol surface-treated with an agent or the like.

The inorganic filler used in the present embodiment preferably has an average particle size of 1 to 1000 nm, particularly preferably 10 to 500 nm, and even more preferably 15 to 200 nm. When the average particle size of the inorganic filler is 1 nm or more, the hard coat layer 12 obtained by curing the composition for the hard coat layer has a higher surface hardness. Further, since the average particle size of the inorganic filler is 1000 nm or less, the dispersibility of the inorganic filler in the composition for the hard coat layer becomes excellent, and when the hard coat layer 12 is formed on the base material 11, the hard coat layer 12 is formed. It is possible to effectively prevent the occurrence of unevenness on the surface of the hard coat layer 12 opposite to the base material 11. Further, by forming the pressure-sensitive adhesive layer 13 on the surface, it is possible to obtain extremely high smoothness on the surface of the pressure-sensitive adhesive layer 13 opposite to the hard coat layer 12. As a result, the pressure-sensitive adhesive layer 13 can exhibit excellent adhesion to the adherend. The average particle size of the inorganic filler is measured by a laser diffraction / scattering type particle size distribution measuring device.

The content of the inorganic filler in the hard coat layer 12 of the present embodiment is preferably 0 to 90% by mass (90% by mass or less), more preferably 30 to 85% by mass, based on the hard coat layer 12. It is preferably 40 to 80% by mass, more preferably 45 to 70% by mass. When the inorganic filler is contained, the rigidity imparted to the hard coat layer 12 becomes higher when the content is 30% by mass or more. On the other hand, when the content of the inorganic filler is 90% by mass or less, layer formation using the composition for the hard coat layer becomes easy.

(1-4) Other Components The composition for forming the hard coat layer 12 of the present embodiment may contain various additives in addition to the above-mentioned components. Examples of various additives include photopolymerization initiators, antioxidants, antistatic agents, silane coupling agents, antioxidants, thermal polymerization inhibitors, colorants, surfactants, storage stabilizers, plasticizers, and lubricants. , Antifoaming agents, organic fillers and the like.

When the hard coat layer 12 is formed by using ultraviolet rays as active energy rays, it is preferable to use a photopolymerization initiator. The photopolymerization initiator is not particularly limited as long as it functions as a photopolymerization initiator of the active energy ray-curable component used, and for example, an acylphosphine oxide compound, a benzoin compound, an acetophenone compound, a titanosen compound, and a thioxanthone. Examples thereof include compounds and peroxide compounds. Specifically, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, benzoin, benzoin Examples thereof include methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldiphenyl sulfate, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, β-chloranthraquinone and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.

The content of the photopolymerization initiator in the composition for a hard coat layer is usually preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the active energy ray-curable component, and particularly 1 to 20 parts by mass. It is preferably 15 parts by mass.

(2) Thickness of Hard Coat Layer The thickness of the hard coat layer 12 is preferably 0.1 to 10 μm, particularly preferably 0.5 to 7 μm, and further preferably 1 to 4 μm. preferable. When the thickness of the hard coat layer 12 is 0.1 μm or more, the permeation of the hard coat layer 12 by the electrolytic solution is effectively blocked. Further, since the thickness of the hard coat layer 12 is 10 μm or less, the adhesive sheet 1 for a battery has appropriate flexibility, and a surface having a step as in the case of fixing an electrode and an electrode extraction tab. Even when the battery adhesive sheet 1 is attached to the battery adhesive sheet 1, the battery adhesive sheet 1 can follow the step well.

(3) Physical Properties of Hard Coat Layer In the battery adhesive sheet 1 according to the present embodiment, the hard coat layer 12 in the state of being provided on the base material 11 is a load of 250 g / cm ² using # 0000 steel wool. It is preferable that the hard coat layer 12 is rubbed 10 cm and 10 times back and forth without causing scratches. With such an evaluation of steel wool resistance, the permeation of the hard coat layer 12 of the electrolytic solution is effectively blocked, and even when the battery adhesive sheet 1 comes into contact with the electrolytic solution, the adhesive layer 13 Maintains good adhesive strength, and peeling of the battery adhesive sheet 1 from the adherend is effectively suppressed.

1-3. Adhesive layer The adhesive that constitutes the adhesive layer 13 may be any adhesive that exhibits a desired adhesive force to the adherend and can ensure adhesion to the hard coat layer 12. Examples of such adhesives include acrylic adhesives, silicone adhesives, rubber adhesives and urethane adhesives. Among them, an acrylic pressure-sensitive adhesive having excellent adhesion to the hard coat layer 12 formed from the composition for a hard coat layer containing a thermal cross-linking agent is preferable. The acrylic pressure-sensitive adhesive easily chemically reacts with the heat-crosslinking agent or the component derived from the heat-crosslinking agent in the hard coat layer 12, thereby further improving the adhesion to the hard coat layer 12 and when it comes into contact with the electrolytic solution. Even if there is, the adhesion is effectively maintained.

The acrylic pressure-sensitive adhesive is preferably obtained from a pressure-sensitive composition containing the (meth) acrylic acid ester polymer (A) (hereinafter, may be referred to as "sticky composition P"). The adhesive composition P preferably contains a cross-linking agent (B) in addition to the (meth) acrylic acid ester polymer (A), and more preferably contains a silane coupling agent (C). In addition, in this specification, "polymer" shall also include the concept of "copolymer".

(1) Each component (1-1) (meth) acrylic acid ester polymer (A)
The (meth) acrylic acid ester polymer (A) has a preferable adhesiveness by containing a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as a monomer unit constituting the polymer. Can be expressed. Examples of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, propyl (meth) acrylic acid, and n- (meth) acrylic acid. Butyl, n-pentyl (meth) acrylic acid, n-hexyl (meth) acrylic acid, 2-ethylhexyl (meth) acrylic acid, isooctyl (meth) acrylic acid, n-decyl (meth) acrylic acid, (meth) acrylic acid Examples thereof include n-dodecyl, myristyl (meth) acrylate, palmityl (meth) acrylate, and stearyl (meth) acrylate. Above all, from the viewpoint of further improving the adhesiveness, it is preferable that the (meth) acrylic acid ester having 1 to 8 carbon atoms of the alkyl group is contained. These may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (A) preferably contains 50% by mass or more of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as a monomer unit constituting the polymer. In particular, it is preferably contained in an amount of 60% by mass or more, and more preferably 70% by mass or more. When the (meth) acrylic acid alkyl ester is contained in an amount of 50% by mass or more, the (meth) acrylic acid ester polymer (A) can exhibit suitable tackiness. Further, the (meth) acrylic acid ester polymer (A) contains 97% by mass or less of the (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as a monomer unit constituting the polymer. Is preferable, and it is particularly preferable to contain 90% by mass or less, and further preferably 85% by mass or less. By adjusting the amount of the (meth) acrylic acid alkyl ester to 97% by mass or less, a suitable amount of other monomer components can be introduced into the (meth) acrylic acid ester polymer (A).

Further, the (meth) acrylic acid ester polymer (A) is a (meth) acrylic acid ester polymer having 1 to 20 carbon atoms of an alkyl group as a monomer unit constituting the polymer, and a glass transition as a homopolymer. It is also preferable to use a monomer having a temperature (Tg) of more than 0 ° C. (hard monomer) and a monomer having a glass transition temperature (Tg) of 0 ° C. or less (soft monomer) as a homopolymer in combination. Thereby, the elution resistance to the electrolytic solution can be made more excellent. In this case, the mass ratio of the hard monomer to the soft monomer is preferably 5:95 to 40:60, and particularly preferably 20:80 to 30:70.

Examples of the hard monomer include methyl acrylate (Tg10 ° C.), methyl methacrylate (Tg105 ° C.), isobornyl acrylate (Tg94 ° C.), isobornyl methacrylate (Tg180 ° C.), adamantyl acrylate (Tg115 ° C.), and methacrylic acid. Adamantane (Tg 141 ° C.) and the like can be mentioned. These may be used alone or in combination of two or more.

Among the above hard monomers, methyl acrylate, methyl methacrylate and isobornyl acrylate are preferable, and methyl acrylate and methacrylic acid are particularly preferable, from the viewpoint of further exerting the performance of the hard monomer while preventing adverse effects on properties such as adhesiveness. Methyl is preferred.

As the soft monomer, an acrylic acid alkyl ester having a linear or branched alkyl group having 2 to 12 carbon atoms is preferably mentioned. For example, 2-ethylhexyl acrylate (Tg-70 ° C.), n-butyl acrylate (Tg-54 ° C.) and the like are preferable, and n-butyl acrylate is particularly preferable. These may be used alone or in combination of two or more.

If desired, the (meth) acrylic acid ester polymer (A) may contain another monomer as a monomer unit constituting the polymer. The other monomer may be a monomer containing a reactive functional group (reactive functional group-containing monomer), or a monomer not containing a reactive functional group. By containing the reactive functional group-containing monomer, the cross-linking agent (B) described later reacts with the reactive functional group of the reactive functional group-containing monomer to form a cross-linked structure and improve the cohesive force of the pressure-sensitive adhesive. To do. Further, the thermal cross-linking agent in the hard coat layer 12 may react with the reactive functional group of the reactive functional group-containing monomer to form a chemical bond. As a result, the adhesiveness between the pressure-sensitive adhesive layer 13 and the hard coat layer 12 is further improved.

Reactive functional group-containing monomers include a monomer having a carboxy group in the molecule (carboxy group-containing monomer), a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), and a monomer having an amino group in the molecule (amino group-containing monomer). ) Etc. can be mentioned. Among these, the (meth) acrylic acid ester polymer (A) preferably contains a carboxy group-containing monomer as a monomer unit constituting the polymer. When a metal chelate-based cross-linking agent is used as the cross-linking agent (B) described later, the carboxy group derived from the carboxy group-containing monomer reacts with the metal chelate-based cross-linking agent when the (meth) acrylic acid ester polymer (A) is cross-linked. As a result, a crosslinked structure, which is a three-dimensional network structure, is formed. The pressure-sensitive adhesive having a crosslinked structure by the reaction of the carboxy group and the metal chelate-based crosslinking agent has high resistance to an electrolytic solution, particularly a non-aqueous electrolytic solution, and is difficult to elute even if it comes into contact with the electrolytic solution.

Examples of the carboxy group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Of these, acrylic acid is preferable. According to acrylic acid, the above effect is more excellent. The above-mentioned carboxy group-containing monomers may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (A) preferably contains a carboxy group-containing monomer as a lower limit value of 0.5% by mass or more, particularly 1% by mass or more, as a monomer unit constituting the polymer. It is preferable that the content is 3% by mass or more. Further, the (meth) acrylic acid ester polymer (A) preferably contains a carboxy group-containing monomer as an upper limit value of 30% by mass or less, and 25% by mass or less, as a monomer unit constituting the polymer. It is more preferable to contain 20% by mass or less, and further preferably 10% by mass or less. When the (meth) acrylic acid ester polymer (A) contains the carboxy group-containing monomer in the above amount as the monomer unit, the above effect becomes more excellent in the obtained pressure-sensitive adhesive.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and (meth). ) Hydroxyalkyl esters of (meth) acrylic acid such as 3-hydroxybutyl acrylate and 4-hydroxybutyl (meth) acrylic acid can be mentioned. These may be used alone or in combination of two or more.

Examples of the amino group-containing monomer include aminoethyl (meth) acrylate, n-butylaminoethyl (meth) acrylate and the like. These may be used alone or in combination of two or more.

The reactive functional group-containing monomer is preferably only the above-mentioned carboxy group-containing monomer so as not to inhibit the effect obtained by the cross-linked structure by the reaction of the carboxy group and the metal chelate-based cross-linking agent.

On the other hand, examples of the reactive functional group-free monomer include (meth) acrylic acid alkoxyalkyl ester such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, and N, (meth) acrylate. (Meta) acrylic acid ester having a non-crosslinkable tertiary amino group such as N-dimethylaminoethyl, N (meth) acrylate, N-dimethylaminopropyl, (meth) acryloylmorpholin, (meth) acrylamide, dimethylacrylamide , Vinyl acetate, styrene and the like. These may be used alone or in combination of two or more.

The polymerization mode of the (meth) acrylic acid ester polymer (A) may be a random copolymer or a block copolymer.

The weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably 50,000 or more, particularly preferably 100,000 or more, and further preferably 200,000 or more as the lower limit value. When the lower limit of the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is at least the above value, the elution resistance of the obtained pressure-sensitive adhesive to the electrolytic solution becomes more excellent.

The weight average molecular weight of the (meth) acrylic acid ester polymer (A) is preferably 2.5 million or less, more preferably 2 million or less, and particularly preferably 1.5 million or less, as an upper limit value. Further, it is preferably 1.3 million or less. When the upper limit of the weight average molecular weight of the (meth) acrylic acid ester polymer (A) is not more than the above, the adhesive strength of the obtained pressure-sensitive adhesive becomes more excellent. The weight average molecular weight in the present specification is a standard polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method.

In the adhesive composition P, one type of (meth) acrylic acid ester polymer (A) may be used alone, or two or more types may be used in combination.

(1-2) Crosslinking agent (B)
As the cross-linking agent (B), the same cross-linking agent as the thermal cross-linking agent that can be used in the hard coat layer 12 can be used, but it is preferable to use a metal chelate-based cross-linking agent. In this case, the (meth) acrylic acid ester polymer (A) preferably contains a carboxy group-containing monomer as a monomer unit constituting the polymer. As described above, the adhesive obtained by this combination has high resistance to an electrolytic solution, particularly a non-aqueous electrolytic solution, and is difficult to elute even if it comes into contact with the electrolytic solution. Therefore, the adhesive does not adversely affect the battery performance, thereby suppressing battery malfunction, thermal runaway and short circuit caused by the adhesive sheet.

As the metal chelate-based cross-linking agent, a metal chelate compound having a metal atom of aluminum, zirconium, titanium, zinc, iron, tin or the like can be used. Of these, aluminum chelate compounds are particularly preferable. The aluminum chelate compound exhibits the above-mentioned elution resistance to the electrolytic solution particularly effectively.

Examples of the aluminum chelate compound include diisopropoxyaluminum monooleylacetate, monoisopropoxyaluminum bisoleylacetate, monoisopropoxyaluminum monooleate monoethylacetate, diisopropoxyaluminum monolaurylacetate, and diisopropoxy. Aluminum monostearyl acetoacetate, diisopropoxyaluminum monoisostearyl acetoacetate, monoisopropoxyaluminum mono-N-lauroyl-β-alanate monolauryl acetoacetate, aluminum tris (acetylacetate), monoacetylacetonate aluminum bis ( Examples thereof include isobutylacetate) chelate, monoacetylacetonate aluminum bis (2-ethylhexylacetate) chelate, monoacetylacetonate aluminum bis (dodecylacetacetate) chelate, monoacetylacetonate aluminum bis (oleylacetacetate) chelate, and the like. .. Among these, aluminum tris (acetylacetonate) is preferable from the viewpoint of the above effects. These may be used alone or in combination of two or more.

Examples of other metal chelate compounds include titanium tetrapropionate, titanium tetra-n-butyrate, titanium tetra-2-ethylhexanoate, zirconium sec-butyrate, zirconium diethoxy-tert-butyrate, and triethanol. Examples thereof include amine titanium dipropionate, an ammonium salt of titanium lactate, and tetraoctylene glycol titanate. These may be used alone or in combination of two or more.

The above-mentioned metal chelate-based cross-linking agent may be used alone or in combination of two or more.

The content of the metal chelate-based cross-linking agent in the pressure-sensitive adhesive composition P according to the present embodiment is 0.1 part by mass or more as a lower limit value with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (A). It is preferably 0.2 parts by mass or more, and further preferably 0.3 parts by mass or more. The content of the metal chelate-based cross-linking agent is preferably 5 parts by mass or less, particularly preferably 4 parts by mass or less, and further preferably 3 parts by mass or less as an upper limit value. When the content of the metal chelate-based cross-linking agent is in the above range, the above-mentioned effect becomes more excellent.

(1-3) Silane coupling agent (C)
The adhesive composition P preferably contains a silane coupling agent (C). When the silane coupling agent (C) is contained, even when the pressure-sensitive adhesive layer 13 comes into contact with the electrolytic solution, it exhibits excellent adhesive strength to the adherend (particularly to the metal member). Further, the obtained pressure-sensitive adhesive layer 13 has higher adhesion to the hard coat layer 12. Therefore, it is necessary to prevent peeling or the like from occurring at the interface between the hard coat layer 12 and the pressure-sensitive adhesive layer 13 due to immersion of the battery adhesive sheet in the electrolytic solution solvent, and to increase the adhesive strength after immersion in the electrolytic solution solvent. Can be done. Further, when the release sheet 14 is peeled from the pressure-sensitive adhesive layer 13, it is possible to effectively prevent the pressure-sensitive adhesive layer 13 from being transferred to the release sheet 14 and peeling from the hard coat layer 12.

The silane coupling agent (C) is preferably an organosilicon compound having at least one alkoxysilyl group in the molecule and having good compatibility with the (meth) acrylic acid ester polymer (A).

Examples of the silane coupling agent (C) include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacrypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and the like. Silicon compounds having an epoxy structure such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, mercapto groups such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxymethylsilane Contains amino groups such as silicon compound, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane Contains silicon compound, 3-chloropropyltrimethoxysilane, 3-isocyanuspropyltriethoxysilane, or at least one of these and an alkyl group such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, etc. Examples thereof include a condensate with a silicon compound. Among these, from the viewpoint of the above effects, a silicon compound having an epoxy structure is preferable, and 3-glycidoxypropyltrimethoxysilane is particularly preferable. These may be used individually by 1 type and may be used in combination of 2 or more type.

The content of the silane coupling agent (C) in the adhesive composition P is preferably 0.01 part by mass or more with respect to 100 parts by mass of the (meth) acrylic acid ester polymer (A), and is 0. It is more preferably 0.05 parts by mass or more, particularly preferably 0.1 parts by mass or more, and further preferably 0.3 parts by mass or more. Further, the content is preferably 5 parts by mass or less, particularly preferably 4 parts by mass or less, and further preferably 3 parts by mass or less. When the content of the silane coupling agent (C) is in the above range, the adhesive strength after immersion in the electrolytic solution becomes more excellent.

(1-4) Various Additives Various additives usually used for acrylic pressure-sensitive adhesives, for example, tackifiers, antioxidants, softeners, fillers, etc., are added to the pressure-sensitive adhesive composition P, if desired. can do. The polymerization solvent and the dilution solvent described later are not included in the additives constituting the adhesive composition P.

(2) Production of Adhesive Composition The adhesive composition P produced a (meth) acrylic acid ester polymer (A), and the obtained (meth) acrylic acid ester polymer (A) was obtained, if desired. It can be produced by adding a cross-linking agent (B), a silane coupling agent (C), an additive and the like.

The (meth) acrylic acid ester polymer (A) can be produced by polymerizing a mixture of monomers constituting the polymer by an ordinary radical polymerization method. The polymerization of the (meth) acrylic acid ester polymer (A) can be carried out by a solution polymerization method or the like using a polymerization initiator, if desired. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone and the like, and two or more of them may be used in combination.

Examples of the polymerization initiator include azo compounds and organic peroxides, and two or more of them may be used in combination. Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane1-carbonitrile), and 2 , 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate) , 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile), 2,2'-azobis [2- (2-imidazolin-2-yl)) Propane] and the like.

Examples of the organic peroxide include benzoyl peroxide, t-butylperbenzoate, cumenehydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, and di (2-ethoxyethyl) peroxy. Examples thereof include dicarbonate, t-butylperoxyneodecanoate, t-butylperoxyvivarate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, diacetyl peroxide and the like.

In the above polymerization step, the weight average molecular weight of the obtained polymer can be adjusted by adding a chain transfer agent such as 2-mercaptoethanol.

When the (meth) acrylic acid ester polymer (A) is obtained, a cross-linking agent (B), a silane coupling agent (C), and an additive are added to the solution of the (meth) acrylic acid ester polymer (A), if desired. Etc. are added and sufficiently mixed to obtain an adhesive composition P.

The adhesive composition P is appropriately diluted with a diluting solvent or the like in addition to the above-mentioned polymerization solvent in order to adjust the viscosity to an appropriate level for coating and to adjust the pressure-sensitive adhesive layer to a desired film thickness. It may be a coating liquid described later. Examples of the diluting solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone and the like, and two or more kinds may be used in combination.

(3) Physical Properties of Adhesive / Adhesive Layer In the battery adhesive sheet 1 according to the present embodiment, the adhesive constituting the adhesive layer 13 is immersed in a solvent of a non-aqueous electrolyte solution at 80 ° C. for 72 hours for adhesion. The gel fraction of the agent is preferably 60% or more, particularly preferably 70% or more, and further preferably 80% or more as the lower limit value. When the lower limit of the gel fraction is the above, the elution amount of the pressure-sensitive adhesive when the pressure-sensitive adhesive layer 13 comes into contact with the electrolytic solution can be suppressed to a low level. As a result, malfunction, thermal runaway, and short circuit of the battery using the battery adhesive sheet 1 are effectively suppressed.

On the other hand, the upper limit of the gel fraction is preferably 100% or less, particularly preferably 99% or less, and further preferably 98% or less. When the upper limit of the gel fraction is 98% or less, the adhesive sheet 1 for a battery has appropriate flexibility, and is used for a battery on a surface having a step as in the case of fixing an electrode and an electrode extraction tab. Even when the adhesive sheet 1 is attached, it is possible to follow the step well.

The solvent of the non-aqueous electrolytic solution here is a prepared solution obtained by mixing ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1. The method for testing the gel fraction is as shown in a test example described later. ..

(4) Thickness of Adhesive Layer The thickness of the adhesive layer 13 (value measured according to JIS K7130) is preferably 1 to 50 μm, particularly preferably 3 to 15 μm, and further 4 It is preferably ~ 9 μm. When the thickness of the pressure-sensitive adhesive layer 13 is 1 μm or more, the pressure-sensitive adhesive sheet 1 for a battery can exhibit good adhesive strength. Further, when the thickness of the pressure-sensitive adhesive layer 13 is 50 μm or less, the amount of the electrolytic solution that infiltrates from the end portion of the pressure-sensitive adhesive layer 13 can be effectively reduced.

1-4. Peeling sheet The peeling sheet 14 protects the adhesive layer until the battery adhesive sheet 1 is used, and is peeled off when the battery adhesive sheet 1 is used. In the battery adhesive sheet 1 according to the present embodiment, the release sheet 14 is not always necessary.

Examples of the release sheet 14 include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene terephthalate film. , Polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film , Liquid crystal polymer film and the like are used. In addition, these crosslinked films are also used. Further, these laminated films may be used.

It is preferable that the peeling surface (the surface in contact with the pressure-sensitive adhesive layer 13) of the peeling sheet 14 is subjected to a peeling treatment. Examples of the release agent used in the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents.

The thickness of the release sheet 14 is not particularly limited, but is usually about 20 to 150 μm.

2. 2. Physical Properties of Adhesive Sheet for Batteries, etc. The adhesive strength (adhesive strength before immersion in the electrolyte solvent) of the adhesive sheet 1 for batteries according to the present embodiment is preferably 0.5 N / 25 mm or more as a lower limit value. In particular, it is preferably 0.75 N / 25 mm or more, and more preferably 1.0 N / 25 mm or more. Since the lower limit of the adhesive strength of the battery adhesive sheet 1 before immersion in the electrolytic solution solvent is as described above, the battery adhesive sheet 1 is attached to an adherend (particularly metal) before the battery adhesive sheet 1 comes into contact with the electrolytic solution. It is unlikely that the problem of peeling from the member) will occur. The upper limit of the adhesive strength before immersion in the electrolytic solution solvent is not particularly limited, but is usually preferably 50 N / 25 mm or less, particularly preferably 30 N / 25 mm or less, and further preferably 10 N / 25 mm or less. Is preferable. The adhesive strength in the present specification basically refers to the adhesive strength measured by the 180 ° peeling method according to JIS Z0237: 2009, and the detailed measurement method is as shown in a test example described later.

Further, after the battery adhesive sheet 1 according to the present embodiment is attached to an aluminum plate and immersed in a solvent of a non-aqueous electrolytic solution at 80 ° C. for 72 hours, the adhesive strength (electrolysis) of the battery adhesive sheet 1 to the aluminum plate. The lower limit of the adhesive strength after immersion in the liquid solvent is preferably 0.5 N / 25 mm or more, more preferably 0.75 N / 25 mm or more, and particularly preferably 1.0 N / 25 mm or more. Furthermore, it is preferably 2.0 N / 25 mm or more. Since the lower limit of the adhesive strength of the battery adhesive sheet 1 after being immersed in the electrolytic solution solvent is as described above, the battery adhesive sheet 1 can be used even after the battery adhesive sheet 1 is in contact with (immersed) in the electrolytic solution. It is unlikely that the problem of peeling from the adherend (especially metal member) will occur. The upper limit of the adhesive strength after immersion in the electrolytic solution solvent is not particularly limited, but is usually preferably 40 N / 25 mm or less, particularly preferably 20 N / 25 mm or less, and further preferably 10 N / 25 mm or less. Is preferable. The adhesive sheet 1 for a battery according to the present embodiment is provided with a hard coat layer 12 between the base material 11 and the adhesive layer 13, and further contains an adhesive composition P containing a silane coupling agent (C). By having the pressure-sensitive adhesive layer 13 formed by using the above range, excellent adhesive strength in the above range can be achieved. The solvent of the non-aqueous electrolytic solution here is a prepared solution obtained by mixing ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1.

The adhesive strength after immersion in the electrolytic solution solvent is preferably 50% or more, more preferably 60% or more, and particularly preferably 70% or more, based on the adhesive strength before immersion in the electrolytic solution solvent. Further, it is preferably 90% or more.

The thickness of the adhesive sheet 1 for a battery (excluding the thickness of the release sheet 14) is preferably 10 to 250 μm, particularly preferably 15 to 110 μm, and further preferably 20 to 45 μm. When the thickness of the battery adhesive sheet 1 is within the above range, the battery adhesive sheet 1 becomes more suitable because it has both adhesive strength and heat resistance.

3. 3. Method for Manufacturing Adhesive Sheet for Batteries In order to manufacture the adhesive sheet 1 for batteries according to the present embodiment, the coating film of the composition for a hard coat layer coated on one surface side of the base material 11 is irradiated with active energy rays. The hard coat layer 12 (hard coat layer 12 before curing) and the coating film of the adhesive composition P were laminated and then cured to form the pressure-sensitive adhesive layer 13 in close contact with the hard coat layer 12. It is preferable to do so. As a result, the heat-crosslinking agent in the hard coat layer 12 reacts with the (meth) acrylic acid ester polymer (A) in the adhesive composition P and chemically bonds with the hard coat layer 12 to adhere to the hard coat layer 12. Adhesion with the agent layer 13 is significantly improved. Even when the battery pressure-sensitive adhesive sheet 1 comes into contact with the electrolytic solution, the adhesion between the hard coat layer 12 and the pressure-sensitive adhesive layer 13 is very excellent, and between the layers between the hard coat layer 12 and the pressure-sensitive adhesive layer 13. The occurrence of peeling is effectively suppressed.

Specifically, the battery pressure-sensitive adhesive sheet 1 according to the present embodiment prepares a laminate of the base material 11 and the hard coat layer 12, and a laminate of the coating film of the adhesive composition P and the release sheet 14, respectively. Then, these laminates are laminated so that the hard coat layer 12 and the coating film of the adhesive composition P are in contact with each other, and then cured to form the adhesive layer 13 from the coating film of the adhesive composition P. It can be manufactured by. From the viewpoint of further improving the adhesion between the hard coat layer 12 and the pressure-sensitive adhesive layer 13, the surface to which either of these layers is bonded or the surface to which both layers are bonded is subjected to corona treatment or plasma treatment. It is also preferable to bond the two layers after performing a surface treatment such as.

The laminate of the base material 11 and the hard coat layer 12 can be produced, for example, as follows. First, a coating liquid containing a composition for a hard coat layer and, if desired, a solvent is applied to one main surface of the base material 11 and dried. The coating liquid may be applied by a conventional method, for example, by a bar coating method, a knife coating method, a Meyer bar method, a roll coating method, a blade coating method, a die coating method, or a gravure coating method. Drying can be performed, for example, by heating at 80 to 150 ° C. for about 30 seconds to 5 minutes.

Then, the layer obtained by drying the coating liquid is irradiated with active energy rays to cure the layer and form the hard coat layer 12. As the active energy beam, for example, an electromagnetic wave or a charged particle beam having an energy quantum can be used, and specifically, an ultraviolet ray, an electron beam, or the like can be used. In particular, ultraviolet rays that are easy to handle are preferable. The irradiation of ultraviolet rays can be performed by a high-pressure mercury lamp, a xenon lamp, or the like, and the irradiation amount of ultraviolet rays is preferably about 50 to 1000 mW / cm ² . Further, the light quantity is preferably 50~10000mJ / cm ^2, more preferably 80~5000mJ / cm ^2, and particularly preferably 200~2000mJ / cm ^2. On the other hand, the irradiation of the electron beam can be performed by an electron beam accelerator or the like, and the irradiation amount of the electron beam is preferably about 10 to 1000 grad.

The laminate of the coating film of the adhesive composition P and the release sheet 14 can be produced, for example, as follows.

The above-mentioned adhesive composition P and a coating liquid containing a solvent if desired are applied to the release surface of the release sheet 14 and heat-treated to form a coating film of the adhesive composition P.

The above heat treatment can also be used as a drying treatment for volatilizing the diluting solvent or the like of the coating liquid. When the heat treatment is performed, the heating temperature is preferably 50 to 150 ° C., particularly preferably 70 to 120 ° C. The heating time is preferably 30 seconds to 10 minutes, and particularly preferably 50 seconds to 2 minutes.

After the hard coat layer 12 on the base material 11 and the coating film of the adhesive composition P on the release sheet 14 are bonded together, curing is performed. This curing is usually carried out at room temperature (for example, 23 ° C., 50% RH) for about 1 to 2 weeks. As a result, the coating film of the adhesive composition P becomes the adhesive layer 13, and the adhesive layer 13 in close contact with the hard coat layer 12 is formed.

As another method for producing the adhesive sheet 1 for batteries according to the present embodiment, a hard coat layer 12 (before curing) is formed on the base material 11, and the adhesive composition is directly applied to the hard coat layer 12 (before curing). The pressure-sensitive adhesive layer 13 in close contact with the hard coat layer 12 may be formed by curing after forming the coating film of the product P.

[Lithium-ion battery]
The lithium ion battery according to the embodiment of the present invention is fixed inside the battery in a state where two or more conductors are in contact with each other by using the above-mentioned adhesive sheet for a battery. It is preferable that at least one of the two or more conductors is in the form of a sheet and at least one is in the form of a line or tape. Hereinafter, the lithium ion battery according to the preferred embodiment will be described.

As shown in FIG. 2, the lithium ion battery 2 according to the present embodiment has a bottomed cylindrical outer body 21 whose bottom constitutes a negative electrode terminal 23, and a positive electrode terminal 22 provided in an opening of the outer body 21. The electrode body 24 provided inside the exterior body 21 is provided. Further, an electrolytic solution is sealed inside the lithium ion battery 2.

The electrode body 24 is a sheet-shaped (strip-shaped) positive electrode current collector 241 on which the positive electrode active material layer 241a is laminated, and a negative electrode current collector 242 on which the negative electrode active material layer 242a is laminated, and between them. It includes an intervening separator 243. The laminated body of the positive electrode current collector 241 and the positive electrode active material layer 241a may be referred to as a positive electrode, and the laminated body of the negative electrode current collector 242 and the negative electrode active material layer 242a may be referred to as a negative electrode, and the positive electrode and the negative electrode are included. It may be called an electrode. The positive electrode, the negative electrode, and the separator 243 are each wound and inserted into the exterior body 21.

Further, as shown in FIG. 3, a linear or tape-shaped electrode take-out tab 244 is attached to the positive electrode current collector 241 by the above-mentioned battery adhesive sheet 1, whereby the electrode take-out tab 244 is attached. It is electrically connected to the positive electrode current collector 241. The electrode extraction tab 244 is also electrically connected to the positive electrode terminal 22. The negative electrode current collector 242 is electrically connected to the negative electrode terminal 23 via an electrode extraction tab (not shown).

Generally, the positive electrode current collector 241 and the negative electrode current collector 242 are made of a metal such as aluminum, and the electrode extraction tab 244 is made of a metal such as aluminum or copper.

The electrolytic solution used in the lithium ion battery 2 is usually a non-aqueous electrolytic solution. As the non-aqueous electrolyte solution, for example, a solution in which a lithium salt as an electrolyte is dissolved in a mixed solvent of a cyclic carbonate ester and a lower chain carbonate ester is preferable. Lithium salts include fluorine-based complex salts such as lithium hexafluorophosphate (LiPF ₆ ) and lithium borofluoride (LiBF ₄ ), LiN (SO ₂ Rf) ₂ , LiC (SO ₂ Rf) ₃ (however, Rf = CF ₃ , C ₂ F ₅ ) etc. are used. Further, as the cyclic carbonate, ethylene carbonate, propylene carbonate and the like are used, and as the lower chain carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and the like are preferably mentioned.

The lithium ion battery 2 according to the present embodiment can be manufactured by a usual method except that the above-mentioned battery adhesive sheet 1 is used for fixing the electrode extraction tab 244.

In the lithium ion battery 2 according to the present embodiment, the electrode extraction tab 244 is attached to the positive electrode 241 by the battery adhesive sheet 1. In this adhesive sheet 1 for batteries, by providing the hard coat layer 12 between the base material 11 and the adhesive layer 13, the amount of the electrolytic solution that penetrates into the adhesive layer 13 is reduced, so that the adhesive strength is good. It is maintained and the battery adhesive sheet 1 is prevented from peeling off from the adherend. Further, by reducing the amount of the electrolytic solution that penetrates into the pressure-sensitive adhesive layer 13, the amount of the components of the pressure-sensitive adhesive layer 13 that elutes into the electrolytic solution is reduced. As a result, malfunction, thermal runaway, and short circuit of the battery using the adhesive sheet 1 are suppressed.

Further, the adhesive sheet 1 for a battery has adhesion between the hard coat layer 12 and the pressure-sensitive adhesive layer 13 and adhesion between the hard coat layer 12 and the base material 11 even when immersed in a non-aqueous electrolytic solution. It has excellent properties and suppresses peeling between those layers.

Furthermore, since the adhesive sheet 1 for a battery includes a hard coat layer 12, the insulating property can be ensured even when the base material 11 and the adhesive layer 13 are carbonized.

From the above, the lithium ion battery 2 according to the present embodiment is highly reliable as a battery because performance deterioration, malfunction, thermal runaway and short circuit caused by the adhesive sheet are suppressed. It is expected to be excellent in temperature stability and safety even under the condition of electric current.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, in the battery adhesive sheet 1, the release sheet 14 may be omitted. Further, in the battery pressure-sensitive adhesive sheet 1, another layer may be provided between the base material 11 and the hard coat layer 12, or between the hard coat layer 12 and the pressure-sensitive adhesive layer 13.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Example 1]
1. 1. Formation of hard coat layer on substrate 40 parts by mass of dipentaerythritol hexaacrylate (material in which no glass transition point is observed after curing) as an active energy ray-curable component and 5 parts by mass of hydroxycyclohexylphenyl ketone as a photopolymerization initiator Parts, 60 parts by mass of organosilica sol as an inorganic filler (manufactured by Nissan Chemical Co., Ltd., trade name "MEK-ST"; average particle size 30 nm) (solid content conversion value; the same applies hereinafter), and trimethylolpropane as a thermal crosslinking agent A coating solution for a hard coat layer was prepared by mixing with 10 parts by mass of a modified hexamethylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name “Coronate HL”) and diluting with methyl ethyl ketone.

After applying the above coating liquid to one surface of a polyimide film as a base material (manufactured by Toray DuPont, trade name "Kapton 100H", thickness 25 μm, flame retardant level V-0 of UL94 standard) with a knife coater, It was dried at 70 ° C. for 1 minute. Next, the coating film was cured by irradiating the coating film with ultraviolet rays (illuminance 230 mW / cm ² , light intensity 510 mJ / cm ² ). As a result, a first laminate in which a hard coat layer having a thickness of 2 μm was formed on one surface of the base material was obtained.

2. 2. Formation of a coating film of an adhesive composition on a release sheet (meth) acrylic by copolymerizing 76.8 parts by mass of butyl acrylate, 19.2 parts by mass of methyl acrylate and 4 parts by mass of acrylic acid by a solution polymerization method. An acid ester polymer was prepared. When the molecular weight of this polymer was measured by gel permeation chromatography (GPC) described later, the weight average molecular weight (Mw) was 1 million.

Next, 100 parts by mass of the obtained (meth) acrylic acid ester polymer and aluminum tris (acetylacetoneate) as a metal chelate-based cross-linking agent (manufactured by Soken Kagaku Co., Ltd., trade name "M-5A") 0.93 By mixing 0.5 parts by mass with 0.5 parts by mass of 3-glycidoxypropylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403") as a silane coupling agent and diluting with methyl ethyl ketone, adhesion is achieved. A coating solution of the sex composition was prepared.

The obtained coating liquid is applied to the peeling surface of a release sheet (manufactured by Lintec Corporation, trade name "PET251130") in which one side of a polyethylene terephthalate film is peeled with a silicone-based release agent, and then applied with a knife coater, and then at 120 ° C. Heat treated for minutes. As a result, a second laminate in which the coating film of the adhesive composition was laminated on the peeled surface of the release sheet was obtained.

3. 3. Preparation of Adhesive Sheet for Batteries The surface of the first laminate prepared as described above on the hard coat layer side and the surface of the second laminate prepared as described above on the coating film side of the adhesive composition are bonded together. Then, it was cured at 23 ° C. and 50% RH for 7 days. As a result, an adhesive sheet for a battery in which the coating film of the adhesive composition was an adhesive layer was obtained. The thickness of the pressure-sensitive adhesive layer was 7 μm. The thickness of the pressure-sensitive adhesive layer was calculated by determining the total thickness of the pressure-sensitive adhesive sheet for batteries and subtracting the thicknesses of the first laminate and the release sheet from the total thickness.

[Example 2]
40 parts by mass of dipentaerythritol hexaacrylate (a material in which a glass transition point is not observed after curing) as an active energy ray-curable component, 5 parts by mass of hydroxycyclohexylphenyl ketone as a photopolymerization initiator, and an organosilica sol as an inorganic filler. (Manufactured by Nissan Chemical Co., Ltd., trade name "MEK-ST"; average particle size 30 nm) 60 parts by mass and trimethylolpropane-modified hexamethylene diisocyanate as a thermal cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL") A coating solution for a hard coat layer was prepared by mixing with 5 parts by mass and diluting with methyl ethyl ketone. An adhesive sheet for a battery was produced in the same manner as in Example 1 except that the obtained coating liquid for the hard coat layer was used as the coating liquid for the hard coat layer.

[Comparative Example 1]
40 parts by mass of dipentaerythritol hexaacrylate (material in which no glass transition point is observed after curing) as an active energy ray-curable component, 5 parts by mass of hydroxycyclohexylphenyl ketone as a photopolymerization initiator, and organosilica sol as an inorganic filler. A coating solution for a hard coat layer was prepared by mixing with 60 parts by mass (manufactured by Nissan Chemical Co., Ltd., trade name "MEK-ST"; average particle size 30 nm) and diluting with methyl ethyl ketone. An adhesive sheet for a battery was produced in the same manner as in Example 1 except that the obtained coating liquid for the hard coat layer was used as the coating liquid for the hard coat layer.

Here, the above-mentioned weight average molecular weight (Mw) is a standard polystyrene-equivalent weight average molecular weight measured under the following conditions (GPC measurement) using gel permeation chromatography (GPC).
<Measurement conditions>
-GPC measuring device: HLC-8020 manufactured by Tosoh Corporation
-GPC column (passed in the following order): TSK guard volume HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (x2)
TSK gel G2000HXL
・ Measurement solvent: tetrahydrofuran ・ Measurement temperature: 40 ° C

[Test Example 1] (Steel wool resistance test)
Regarding the surface of the hard coat layer in the first laminate obtained during the production of the adhesive sheet for batteries of Examples and Comparative Examples, using # 0000 steel wool, a load of 250 g / cm ² was applied to 10 cm, 10 cm. After reciprocating rubbing, the surface of the hard coat layer was evaluated according to the following criteria. The results are shown in Table 1.
〇: No linear scratches were seen.
X: Linear scratches were observed.

[Test Example 2] (Measurement of gel fraction by immersion in electrolyte solvent)
The surface of the adhesive composition of the second laminate obtained during the production of the adhesive sheet for batteries of Examples and Comparative Examples and one side of the polyethylene terephthalate film were peeled off with a silicone-based release agent. The peeling sheet (manufactured by Lintec Corporation, trade name "PET251130") was bonded to the peeled surface. Then, it was cured at 23 ° C. and 50% RH for 7 days to obtain a measurement sheet composed of an adhesive layer alone whose both sides were protected by a release sheet.

The obtained measurement sheet was cut into a size of 80 mm × 80 mm, the release sheet protecting both sides of the adhesive layer was peeled off, wrapped in a polyester mesh (mesh size 200), and the mass was weighed with a precision balance. The mass of the adhesive alone was calculated by subtracting the mass of the mesh alone. The mass at this time is M1. Next, the pressure-sensitive adhesive wrapped in the polyester mesh was immersed in a preparation solution prepared by mixing ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1 as an electrolytic solution solvent at 80 ° C. for 72 hours. After that, the pressure-sensitive adhesive layer is taken out and once immersed in ethanol to dissolve and remove the adhered electrolyte solvent, and then air-dried for 24 hours in an environment of a temperature of 23 ° C. and a relative humidity of 50%, and further in an oven at 80 ° C. It was dried in the oven for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the adhesive alone was calculated by subtracting the mass of the mesh alone. The mass at this time is M2. The gel fraction (%) was calculated from the formula (M2 / M1) × 100. The results are shown in Table 1.

[Test Example 3] (Measurement of adhesive strength before immersion in electrolyte solvent)
The adhesive strength of the battery adhesive sheet according to this test example was measured according to JIS Z0237: 2009 except for the operations shown below.

The battery adhesive sheets obtained in Examples and Comparative Examples were cut into a width of 25 mm and a length of 250 mm, and then the release sheet was peeled off to obtain a test piece. The exposed pressure-sensitive adhesive layer of the test piece was attached to an aluminum plate as an adherend using a 2 kg rubber roller in an environment of 23 ° C. and 50% RH. Immediately after that, the test piece is peeled from the aluminum plate at a peeling angle of 180 ° and a peeling speed of 300 mm / min using a universal tensile tester (manufactured by Orientec Co., Ltd., trade name “Tencilon UTM-4-100”). The adhesive strength (N / 25 mm) was measured. This measured value was taken as the adhesive strength before immersion in the electrolytic solution solvent. The results are shown in Table 1.

[Test Example 4] (Measurement of adhesive strength after immersion in electrolyte solvent)
The adhesive strength of the battery adhesive sheet according to this test example was measured according to JIS Z0237: 2009 except for the operations shown below.

The battery adhesive sheets obtained in Examples and Comparative Examples were cut into a width of 25 mm and a length of 250 mm, and then the release sheet was peeled off to obtain a test piece. The exposed adhesive layer of this test piece was attached to an aluminum plate as an adherend using a 2 kg rubber roller in an environment of 23 ° C. and 50% RH, and then left in the same environment for 20 minutes. Then, with the test piece attached to the aluminum plate, it was immersed in a preparation solution prepared by mixing ethylene carbonate and diethyl carbonate as an electrolytic solution solvent at a volume ratio of 1: 1 at 80 ° C. for 72 hours. Immediately after taking out from the prepared liquid, the adhesive strength (N / 25 mm) was measured in the same manner as described above. This measured value was taken as the adhesive strength after immersion in the electrolytic solution solvent. The results are shown in Table 1.

In the above test, in the battery pressure-sensitive adhesive sheet of the example, peeling did not occur between the pressure-sensitive adhesive layer and the base material (hard coat layer), but in the battery pressure-sensitive adhesive sheet of the comparative example, the pressure-sensitive adhesive layer and the base were formed. Peeling occurred between the material (hard coat layer). From this result, it was found that the battery pressure-sensitive adhesive sheet of the example was excellent in adhesion between the pressure-sensitive adhesive layer and the hard coat layer (base material) even after being immersed in the electrolytic solution solvent.

[Test Example 5] (Evaluation of Adhesive Layer Adhesion)
The release sheet was peeled off from the battery adhesive sheets obtained in Examples and Comparative Examples, and parallel cuts were made in the exposed adhesive layer at 2 mm intervals, and this was used as a test piece. The pressure-sensitive adhesive layer of the test piece is rubbed with a finger from a direction perpendicular to the pressure-sensitive adhesive layer with a force of 1.96 N, and the presence or absence of peeling of the pressure-sensitive adhesive layer is observed, and the adhesion of the pressure-sensitive adhesive layer is determined according to the following criteria. (Before immersion in the electrolyte solvent) was evaluated. The results are shown in Table 1.
◎… There was no peeling of the adhesive layer.
○… There was a slight peeling of the adhesive layer only around the notch.
×: The entire surface of the adhesive layer was peeled off.

Further, the above test piece was immersed in a preparation solution prepared by mixing ethylene carbonate and diethyl carbonate in a volume ratio of 1: 1 as an electrolytic solution solvent at 80 ° C. for 72 hours. Then, after taking it out from the preparation liquid, lightly wipe the surface of the adhesive layer of the test piece with a paper waste (manufactured by Nippon Paper Crecia, trade name "Kimwipe S-200"), and adherence of the adhesive layer (adhesion of the adhesive layer in the same manner as above). After immersion in the electrolyte solvent) was evaluated. The results are shown in Table 1.

As is clear from Table 1, the adhesive sheet for batteries of the examples showed high adhesive strength (50% or more with respect to the adhesive strength before immersion in the electrolytic solution solvent) even after being immersed in the electrolytic solution solvent. Further, the pressure-sensitive adhesive layer of the battery pressure-sensitive adhesive sheet of the example showed high adhesion to the base material (hard coat layer) even after being immersed in the electrolytic solution solvent.

The adhesive composition and the adhesive sheet for a battery according to the present invention are suitable for attaching an electrode extraction tab to an electrode (current collector) inside a lithium ion battery.

1 ... Adhesive sheet for batteries 11 ... Base material 12 ... Hard coat layer 13 ... Adhesive layer 14 ... Peeling sheet 2 ... Lithium ion battery 21 ... Exterior body 22 ... Positive electrode terminal 23 ... Negative electrode terminal 24 ... Electrode body 241 ... Positive electrode current collection Body 241a ... Positive electrode active material layer 242 ... Negative electrode current collector 242a ... Negative electrode active material layer 243 ... Separator 244 ... Electrode extraction tab

Claims (7)

With the base material
A hard coat layer provided on one surface side of the base material and
The hard coat layer is provided with an adhesive layer provided on the surface side opposite to the base material.
An adhesive sheet for a battery, wherein the hard coat layer is formed of a composition for a hard coat layer containing a thermal cross-linking agent and an active energy ray-curable component . The pressure-sensitive adhesive sheet for a battery according to claim 1, wherein the thermal cross-linking agent is an isocyanate-based cross-linking agent. The hard coat layer composition comprises a said heat cross-linking agent, cell adhesive sheet according to claim 1 or 2, and the active energy ray-curable component, characterized by containing an inorganic filler. The pressure-sensitive battery adhesive sheet according to any one of claims 1 to 3, wherein the base material is a film made of a polymer having a nitrogen-containing ring structure in the main chain. The pressure-sensitive adhesive sheet for a battery according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing a (meth) acrylic acid ester polymer. .. A battery pressure-sensitive adhesive sheet comprising a base material, a hard coat layer provided on one surface side of the base material, and an adhesive layer provided on the surface of the hard coat layer opposite to the base material. It ’s a manufacturing method,
Adhesive to a hard coat layer formed by irradiating a coating film of a composition for a hard coat layer containing at least an active energy ray-curable component and a thermal cross-linking agent applied to one surface side of a base material with active energy rays. A method for producing an adhesive sheet for a battery, which comprises laminating a coating film of a sex composition and then curing it to form an adhesive layer in close contact with the hard coat layer. Lithium ion characterized in that two or more conductors are fixed in contact with each other using the battery adhesive sheet according to any one of claims 1 to 5 inside the battery. battery.

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