Cover film attached gas adsorption sheet for secondary battery

Abstract

To provide a gas adsorption sheet capable of preferably adsorbing a sulfur gas.SOLUTION: A cover film attached gas adsorption sheet for a secondary battery includes: a gas adsorption sheet for a secondary battery including a heat-resistant base material and a gas adsorption layer disposed on at least one side of the heat-resistant base material; and a cover film disposed on a side of the gas adsorption layer opposite to the heat-resistant base material. The gas adsorption layer includes binder resin and gas adsorption particles that are formed of an inorganic porous material having pores and being capable of adsorbing a gas.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a gas adsorption sheet for a secondary battery with a cover film.

Background Art

[0002] In recent years, as secondary batteries with high energy density, all-solid-state batteries have been studied. Since all-solid-state batteries do not use flammable organic solvents in the battery, they have excellent safety, and also have advantages such as being less likely to cause electrolyte degradation due to rapid charging and operating stably in a high-temperature environment. In such all-solid-state batteries, from the viewpoint of output current, sulfide-based solid electrolytes are used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in an all-solid-state battery configured using a sulfide-based solid electrolyte, when the sulfide-based solid electrolyte comes into contact with moisture, sulfide-based gases such as hydrogen sulfide are generated, and there are problems in terms of safety due to gas leakage. The present invention has been made to solve such problems, and an object thereof is to provide a gas adsorption sheet capable of preferably adsorbing sulfide-based gases.

Means for Solving the Problems

[0005] [1] The gas adsorption sheet for a secondary battery with a cover film according to an embodiment of the present invention includes a heat-resistant substrate and a gas adsorption layer disposed on at least one side of the heat-resistant substrate, and is a gas adsorption sheet for a secondary battery; and a cover film disposed on the side of the gas adsorption layer opposite to the heat-resistant substrate; and the gas adsorption layer includes a binder resin, an inorganic porous material having pores, and gas adsorption particles capable of adsorbing gas. [2] The gas adsorption sheet for a secondary battery with a cover film according to [1] above may further include an intermediate layer disposed between the heat-resistant substrate and the gas adsorption layer. [3] In the gas adsorption sheet for a secondary battery with a cover film according to [1] or [2] above, the gas adsorption particles are a composite of at least one metal salt selected from copper, zinc, manganese, cobalt, and nickel and a silicate, and the pore volume of the gas adsorption particles is preferably 0.3 ml / g to 0.5 ml / g. [4] In the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to [3] above, the gas adsorption particles may have a surface-treated surface with silicone. [5] In the gas adsorption sheet for a secondary battery with a cover film according to [4] above, the silicone may have an ethoxysilane group or a methoxysilane group. [6] In the gas adsorption sheet for a secondary battery with a cover film according to [4] above, the silicone may be a silane coupling agent containing an epoxy group or an amino group. [7] In the gas adsorption sheet for a secondary battery with a cover film according to [4] above, the silicone may be an alkoxysilane or an organosilazane compound. [8] In the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to [7] above, the binder resin may be an acrylic resin. [9] In the gas adsorption sheet for a secondary battery with a cover film according to [7] above, the binder resin contains a structural unit derived from an alkyl (meth)acrylate, and the alkyl (meth)acrylate may have a linear or branched alkyl group having 4 to 12 carbon atoms.

[10] In the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to [9] above, the binder resin may be butyl rubber, isoprene rubber, polyisobutylene rubber, ethylene propylene rubber, or a silicone-based resin.

[11] In the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to

[10] above, the content ratio of the gas adsorption particles may be 10 parts by weight to 90 parts by weight with respect to 100 parts by weight of the gas adsorption sheet for a secondary battery.

[12] In the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to

[11] above, the material constituting the heat-resistant base material may be polyamideimide, polyetherimide, polyphenylene sulfide, polyethylene naphthalate, polyimide, or polyetheretherketone.

[13] In the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to

[12] above, the cover film may include a base material and an adhesive layer disposed on at least one side of the base material.

[14] In the gas adsorption sheet for a secondary battery with a cover film according to

[13] above, the adhesive layer is formed from an adhesive containing a base polymer, and the content ratio of the structural unit derived from the organic acid monomer may be preferably 0.5 part by weight or less with respect to 100 parts by weight of the base polymer.

[15] In the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to

[14] above, the cover film may be peelable.

[16] The all-solid-state secondary battery according to an embodiment of the present invention includes the gas adsorption sheet for a secondary battery with a cover film according to any one of [1] to

[15] above.

[17] The all-solid-state secondary battery using a sulfide-based solid electrolyte according to an embodiment of the present invention includes the gas adsorption sheet for a secondary battery with a cover film described in any one of [1] to

[15] above.

Effects of the Invention

[0006] According to the present invention, a gas adsorption sheet capable of preferably adsorbing a sulfide-based gas can be provided.

Brief Description of the Drawings

[0007]

Figure 1

Modes for Carrying Out the Invention

[0008] A. Overall structure of the gas adsorption sheet for a secondary battery with a cover film FIG. 1 is a schematic cross-sectional view of a gas adsorption sheet for a secondary battery with a cover film (hereinafter, also simply referred to as a gas adsorption sheet with a cover film) according to one embodiment of the present invention. The gas adsorption sheet 100 with a cover film includes a gas adsorption sheet 110 for a secondary battery (hereinafter, also simply referred to as a gas adsorption sheet) including a heat-resistant base material 10 and a gas adsorption layer 20 disposed on at least one side of the heat-resistant base material 10, and a cover film 120 disposed on the side opposite to the heat-resistant base material 10 of the gas adsorption layer 20. The gas adsorption layer includes a binder resin and gas adsorption particles. The gas adsorption particles are composed of an inorganic porous material having pores. In this specification, the gas adsorption particles are particles that can adsorb sulfur-based gas by the action of chemisorption and exhibit gas adsorption performance. Hydrogen sulfide is exemplified as the sulfur-based gas. In one embodiment, the gas adsorption sheet 110 further includes an intermediate layer 30 between the heat-resistant base material 10 and the gas adsorption layer 20. By forming the intermediate layer, the peeling off of the gas adsorption layer can be prevented. Also, in one embodiment, the cover film 120 includes a base material 41 and an adhesive layer 51 disposed on at least one side of the base material 4,1. The adhesive layer 51 can be laminated so as to face the gas adsorption layer 20. The gas adsorption sheet with a cover film and the gas adsorption sheet may be provided with any other appropriate layer as long as the effects of the present invention can be obtained. For example, an adhesive layer disposed on one or both outer surfaces of the gas adsorption sheet may be provided (not shown).

[0009] According to an embodiment of the present invention, by dispersing gas adsorption particles in a binder resin to form a gas adsorption layer composed of the gas adsorption particles and the binder resin and forming it into a sheet, a gas adsorption sheet that can be applied to various uses with good handleability can be obtained. Further, by providing a heat-resistant base material, the effect of improving handleability becomes more remarkable. Furthermore, by using a heat-resistant base material as the base material, it becomes possible to heat the gas adsorption sheet before use (for example, heating at 200°C for 24 hours). By heating before use, unnecessary substances attached to the gas adsorption particles can be removed, and at the time of use, the performance of the gas adsorption particles can be sufficiently exhibited.

[0010] The above gas adsorption sheet can be suitably used, for example, as a gas adsorbent for all-solid-state batteries. The above gas adsorption sheet is advantageous in that it can absorb even a trace amount of sulfur-based gas with a high absorption rate and has little re-release.

[0011] In addition, the gas adsorption sheet with a cover film can prevent the desorption, breakage, etc. of the gas adsorption layer by having the cover film, and the performance of the gas adsorption particles can be preferably exhibited. The gas adsorption sheet with a cover film can be used as a gas adsorption sheet by peeling off the cover film.

[0012] B. Gas adsorption sheet The H2S adsorption amount of the above gas adsorption sheet is preferably 10 mg / g or more, more preferably 30 mg / g or more, still more preferably 50 mg / g or more, particularly preferably 80 mg / g or more, and most preferably 100 mg / g or more. Also, the upper limit of the H2S adsorption amount of the above gas adsorption sheet is, for example, 500 mg / g, preferably 800 mg / g, and more preferably 1000 mg / g. The method for measuring the H2S adsorption amount will be described later.

[0013] One or both sides of the above gas adsorption sheet may have adhesiveness, or it may be a gas adsorption sheet without adhesiveness. Examples of the form of the gas adsorption sheet having adhesiveness include a form in which the gas adsorption layer has adhesiveness, a form in which an adhesive layer is disposed on the outermost side of the gas adsorption sheet, and the like.

[0014] When the above gas adsorption sheet has adhesiveness, the adhesive force of the gas adsorption sheet to a stainless steel plate at 23°C is preferably 0.1 N / 19 mm to 30 N / 19 mm, more preferably 0.5 N / 19 mm to 20 N / 19 mm. If it is within such a range, a gas adsorption sheet suitable for battery applications can be obtained. In this specification, the adhesive force is the adhesive force measured by a method according to JIS Z 0237:2000. A 2 kg roller is used to stick an adhesive tape to a adherend (SUS304BA) by one reciprocation, and after leaving it at 25°C for 30 minutes, the adhesive tape is peeled off and measured under the conditions of a peeling angle of 180° and a peeling speed (tensile speed) of 300 mm / min.

[0015] The thickness of the above gas adsorption sheet is preferably 10 μm to 1000 μm, more preferably 20 μm to 500 μm, still more preferably 20 μm to 150 μm, still more preferably 20 μm to 120 μm, and particularly preferably 20 μm to 110 μm. If it is within such a range, a gas adsorption sheet excellent in gas adsorption performance and handleability can be obtained.

[0016] B-1. Gas adsorption layer As described above, the gas adsorption layer contains a binder resin and gas adsorption particles dispersed in the binder resin. In the present invention, by adopting such a form, it becomes possible to form a gas adsorption layer by coating using a coating liquid containing a binder resin and gas adsorption particles. As a result, a gas adsorption layer excellent in the dispersibility of gas adsorption particles can be formed, and a gas adsorption sheet excellent in gas adsorption performance can be obtained.

[0017] The thickness of the above gas adsorption layer is preferably 5 μm to 150 μm, more preferably 5 μm to 100 μm, still more preferably 10 μm to 80 μm. If it is within such a range, a gas adsorption layer in which the performance of gas adsorption particles can be sufficiently exhibited can be obtained. Also, a gas adsorption sheet excellent in handleability can be obtained.

[0018] (Gas adsorption particles) As described above, the gas adsorption particles can adsorb sulfur-based gases by chemisorption. Chemisorption means adsorbing the target gas to be adsorbed by a chemical reaction. The gas adsorption particles are composed of an inorganic porous material having pores. In one embodiment, the gas adsorption particles can be a composite of at least one metal salt selected from copper, zinc, manganese, cobalt, and nickel and a silicate.

[0019] Preferably, as the metal (metal ion) constituting the metal salt, copper, zinc, or manganese is used, and more preferably copper or zinc is used. By using these metals, a gas adsorption sheet having particularly excellent adsorbability for sulfur-based gases can be obtained. In addition, a gas adsorption sheet that can be easily determined whether it has been used can be provided due to the coloring after gas adsorption. Examples of the acid forming the metal salt include sulfuric acid, hydrochloric acid, nitric acid, and the like.

[0020] As the silicate, an alkali metal silicate is preferable, sodium silicate or potassium silicate is more preferable, and sodium silicate is particularly preferable.

[0021] The molar ratio of the metal salt to the silicate (metal salt / silicate) is preferably 0.29 or more and less than 0.5, more preferably 0.3 to 0.45, and even more preferably 0.3 to 0.4.

[0022] In one embodiment, the gas adsorption particles have a surface-treated surface. The surface treatment can be a treatment for adjusting the affinity between the gas adsorption particles and the binder resin. By using the gas adsorption particles having a surface-treated surface, a gas adsorption layer excellent in mechanical strength and difficult to fall off can be formed. In the gas adsorption sheet with a cover film provided by laminating the cover film, when peeling the cover film during use of the gas adsorption sheet, it is particularly preferable in that damage to the gas adsorption layer can be prevented. Further, by using the gas adsorption particles having a surface-treated surface, a gas adsorption sheet excellent in workability during cutting can be obtained. For example, when punching out the gas adsorption sheet with a blade type such as a Thomson blade type, damage to the gas adsorption layer can be prevented. The surface-treated surface may be the entire surface of the gas adsorption particles or a partial surface of the surface. Examples of the surface treatment include silane coupling agent treatment, isocyanate compound treatment, thiol compound treatment, acid compound treatment, alcohol compound treatment, epoxy compound treatment, and the like. In one embodiment, the surface treatment can be a coupling treatment. By using the gas adsorption particles subjected to the coupling treatment, the effects of preventing detachment of the gas adsorption layer and improving workability become remarkable.

[0023] In one embodiment, gas adsorption particles having a surface treatment surface with silicone are used. In one embodiment, the silicone has an ethoxysilane group or a methoxysilane group. By using such silicone, a gas adsorption layer excellent in mechanical strength and difficult to fall off can be formed. The above silicone can be a silane coupling agent. Preferably, the silane coupling agent contains an epoxy group and / or an amino group. By using such a silane coupling agent, a gas adsorption layer excellent in mechanical strength and difficult to fall off can be formed. The above gas adsorption particles, that is, the gas adsorption particles surface-treated with silicone (silane coupling agent), can be obtained by bringing the silane coupling agent into contact with the surface of the gas adsorption particles and reacting the organic groups (for example, hydroxyl groups) present on the surface with the silanol groups generated by the hydrolysis of the silane coupling agent, or by bonding the oligomers generated by the condensation of silanol groups to the gas adsorption particles.

[0024] As the above silane coupling agent, for example, vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, hydrochloride of N-(vinylbenzyl)-2-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-isocyanatopropyltriethoxysilane, dithioltriazinepropyltriethoxysilane and the like can be mentioned.

[0025] In one embodiment, as the above silicone, alkoxysilanes such as phenyltrimethoxysilane; organosilazane compounds such as hexamethyldisilazane and the like are used.

[0026] The average particle diameter (median diameter D50) of the above gas adsorption particles is preferably 10 μm or less. If it is in such a range, a gas adsorption layer with a large gas adsorption amount can be formed. The average particle diameter (median diameter D50) can be measured by a laser diffraction / scattering particle size distribution measuring device.

[0027] The pore volume of the gas adsorption particles is preferably 0.3 ml / g to 0.5 ml / g, more preferably 0.35 ml / g to 0.45 ml / g. If it is within such a range, a gas adsorption sheet having particularly excellent adsorption properties for sulfur-containing gases can be obtained. The pore volume can be measured by the BET method using nitrogen gas.

[0028] The specific surface area of the gas adsorption particles is preferably 100 m 2 / g to 3000 m 2 / g. If it is within such a range, gas adsorption particles having excellent gas adsorption performance and mechanical strength can be obtained. Although gas adsorption particles having a large specific surface area are likely to aggregate, according to the present invention, a gas adsorption layer can be formed with good dispersibility of the gas adsorption particles. <{

[0029] The H2S adsorption amount of the gas adsorption particles is preferably 10 mg / g or more, more preferably 30 mg / g or more, still more preferably 50 mg / g or more, particularly preferably 80 mg / g or more, and most preferably 100 mg / g or more. Further, the upper limit of the H2S adsorption amount of the gas adsorption sheet is, for example, 500 mg / g, preferably 800 mg / g, and more preferably 1000 mg / g.

[0030] The content ratio of the gas adsorption particles is preferably 10 parts by weight to 90 parts by weight, more preferably 30 parts by weight to 80 parts by weight, and still more preferably 40 parts by weight to 70 parts by weight with respect to 100 parts by weight of the gas adsorption sheet. If it is within such a range, a gas adsorption sheet having excellent gas adsorption performance and excellent handleability can be obtained.

[0031] The content ratio of the gas adsorption particles is preferably 10 parts by weight to 2000 parts by weight, more preferably 50 parts by weight to 1500 parts by weight, still more preferably 100 parts by weight to 1000 parts by weight, and particularly preferably 280 parts by weight to 1000 parts by weight, based on 100 parts by weight of the binder resin constituting the gas adsorption layer. Within such a range, a gas adsorption layer in which the gas adsorption particles are hardly desorbed can be obtained. Further, a gas adsorption sheet excellent in gas adsorption performance and handleability can be obtained.

[0032] (Binder resin) As the above binder resin, any appropriate resin can be used as long as the effects of the present invention can be obtained. Examples of the binder resin include acrylic resins; rubber-based resins such as butyl rubber, isoprene rubber, polyisobutylene rubber, and ethylene propylene rubber; silicone resins; urethane resins; epoxy resins; alkyd resins; polyester resins; melamine resins; polyamide resins; polyimide resins; ethylene-vinyl acetate copolymer resins; polyvinyl alcohol-based resins, etc. In one embodiment, an acrylic resin, butyl rubber or silicone resin is preferably used. By using these resins, a gas adsorption layer excellent in the dispersibility of gas adsorption particles can be formed.

[0033] The above binder resin preferably has gas permeability. By using a binder resin having gas permeability, a gas adsorption sheet suitable for battery applications can be obtained. Examples of the resin excellent in gas permeability include rubber-based resins such as acrylic resins, butyl rubber, isoprene rubber, polyisobutylene rubber, and ethylene propylene rubber, silicone resins; urethane resins; epoxy resins; alkyd resins; polyester resins; melamine resins; polyamide resins; polyimide resins, etc.

[0034] In one embodiment, an acrylic resin is used as the binder resin. By using an acrylic resin, a gas adsorption layer in which gas adsorption particles are hardly desorbed can be formed. Further, a gas adsorption layer in which the gas adsorption performance of the gas adsorption particles can be sufficiently exhibited can be formed.

[0035] Examples of the acrylic resin include acrylic resins containing structural units derived from one or more (meth)acrylic acid alkyl esters. The content ratio of the structural units derived from the (meth)acrylic acid alkyl ester is preferably 50 to 97 parts by weight, more preferably 70 to 94 parts by weight, based on 100 parts by weight of the acrylic resin.

[0036] Preferably, the (meth)acrylic acid alkyl ester has a linear or branched alkyl group having 1 to 24 carbon atoms (more preferably 3 to 20 carbon atoms, still more preferably 6 to 18 carbon atoms).

[0037] In one embodiment, the (meth)acrylic acid alkyl ester preferably has a linear or branched alkyl group having 4 to 12 carbon atoms, and more preferably has a linear or branched alkyl group having 6 to 12 carbon atoms. By using an acrylic resin having such a (meth)acrylic acid alkyl ester as a main structural unit to form a gas adsorption layer, a gas adsorption sheet with suppressed discoloration and swelling in the electrolytic solution can be obtained.

[0038] Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, eicosyl (meth)acrylate, and the like.

[0039] In one embodiment, as the above (meth)acrylic acid alkyl ester, a (meth)acrylic acid alkyl ester having a branched alkyl group is used. By using a (meth)acrylic acid alkyl ester having a branched alkyl group, a gas adsorption layer capable of sufficiently exhibiting the gas adsorption performance of the gas adsorption particles can be formed. A (meth)acrylic acid alkyl ester having a linear alkyl group and a (meth)acrylic acid alkyl ester having a branched alkyl group may be used in combination. Further, as the (meth)acrylic acid alkyl ester, a (meth)acrylic acid alkyl ester having a branched alkyl group may be used alone.

[0040] In one embodiment, in the above acrylic resin, the content ratio of the structural unit derived from the (meth)acrylic acid alkyl ester having a branched alkyl group is preferably 20 parts by weight to 100 parts by weight, more preferably 30 parts by weight to 100 parts by weight, still more preferably 50 parts by weight to 100 parts by weight, and particularly preferably 70 parts by weight to 100 parts by weight with respect to 100 parts by weight of the structural unit derived from the (meth)acrylic acid alkyl ester (that is, the total amount of 100 parts by weight of the (meth)acrylic acid alkyl ester having a linear alkyl group (including methyl (meth)acrylate and ethyl (meth)acrylate) and the (meth)acrylic acid alkyl ester having a branched alkyl group).

[0041] Examples of the (meth)acrylic acid alkyl ester having a branched alkyl group include isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, stearyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, 2-methylbutyl (meth)acrylate, and the like. Among them, 2-ethylhexyl (meth)acrylate is preferable.

[0042] The above acrylic resin may contain, if necessary, structural units derived from other monomers copolymerizable with the above (meth)acrylate alkyl esters for the purpose of modifying cohesion, heat resistance, crosslinkability, etc. Such other monomers include, for example, carboxyl group-containing monomers such as (meth)acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid; acid anhydride group-containing monomers such as maleic anhydride, itaconic anhydride; phosphate group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; sulfonic acid group-containing monomers such as styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid; hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl methacrylate; (N-substituted) amide-based monomers such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methylolpropane (meth)acrylamide; (meth)acrylate aminoalkyl-based monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate; (meth)acrylate alkoxyalkyl-based monomers such as methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate; maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide; itaconimide-based monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide;Succinimide-based monomers such as N-(meth)acryloyloxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, N-(meth)acryloyl-8-oxyoctamethylene succinimide; Vinyl-based monomers such as vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methyl vinylpyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine, N-vinyl carboxamides, styrene, α-methylstyrene, N-vinyl caprolactam; Cyanoacrylate monomers such as acrylonitrile, methacrylonitrile; Epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate; Glycol-based acrylic ester monomers such as (meth)acrylic acid polyethylene glycol, (meth)acrylic acid polypropylene glycol, (meth)acrylic acid methoxyethylene glycol, (meth)acrylic acid methoxypolypropylene glycol; Acrylic ester monomers having a heterocyclic ring, halogen atom, silicon atom, etc. such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate; Polyfunctional monomers such as hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate; Olefin-based monomers such as isoprene, butadiene, isobutylene; Vinyl ether-based monomers such as vinyl ether, etc. These monomer components may be used alone or in combination of two or more.;

[0043] The content ratio of the structural unit derived from the above-mentioned other monomer is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, and still more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the acrylic resin.

[0044] In one embodiment, the acrylic resin does not contain a structural unit derived from a carboxyl group-containing monomer such as (meth)acrylic acid. By using such an acrylic resin, it is possible to preferably form a gas adsorption layer while preventing gelation even while containing the above-mentioned gas adsorption particles.

[0045] The weight average molecular weight of the acrylic resin is preferably 300,000 to 2,000,000, and more preferably 500,000 to 1,500,000. The weight average molecular weight can be measured by GPC (solvent: THF).

[0046] B-2. Heat-resistant substrate In this specification, the heat-resistant substrate is a substrate that can withstand heating for 24 hours in an atmosphere of temperature 150 °C / pressure -100 kPa to 0 kPa (preferably, in an atmosphere of temperature 200 °C / pressure -100 kPa to 0 kPa). Specifically, it means a substrate whose dimensional change is 5% or less even when heated for 24 hours in an atmosphere of temperature 150 °C / pressure -100 kPa (preferably, in an atmosphere of temperature 200 °C / pressure -100 kPa). Further, when the heat-resistant substrate is formed from a resin, the heat-resistant substrate means a substrate composed of a resin having a glass transition temperature of 80 °C or higher (preferably 100 °C or higher, more preferably 150 °C or higher). Note that the "glass transition temperature" means the temperature indicating the peak of the loss tangent (tanδ) confirmed under the conditions of a temperature increase rate of 5 °C / min, a sample width of 5 mm, a distance between chucks of 20 mm, and a frequency of 10 Hz in the DMA method (tensile method).

[0047] As the material constituting the heat-resistant substrate, any appropriate material can be adopted as long as the effects of the present invention can be obtained. Preferably, the heat-resistant substrate is made of resin. Examples of the material constituting the heat-resistant substrate include polyamideimide (PAI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyimide (PI), polyetheretherketone (PEEK), and the like. These resins are excellent in heat resistance.

[0048] The thickness of the heat-resistant substrate is preferably 5 μm to 500 μm, more preferably 10 μm to 300 μm, and even more preferably 15 μm to 100 μm. Within such a range, a gas adsorption sheet with particularly excellent handleability can be obtained.

[0049] B-3. Intermediate layer The intermediate layer contains any appropriate resin. Examples of the resin forming the intermediate layer include acrylic resins, rubber resins, silicone resins, and the like. Among them, acrylic resins can be preferably used. Also, as the adhesive, an active energy ray-curable acrylic resin may be used. Examples of the resin constituting the intermediate layer include the above binder resins. In one embodiment, the same resin as the binder resin constituting the gas adsorption layer is used as the resin constituting the intermediate layer. The intermediate layer does not contain gas adsorption particles.

[0050] By forming the intermediate layer, a gas adsorption sheet in which the gas adsorption layer is difficult to peel off can be obtained.

[0051] The thickness of the intermediate layer is preferably 1 μm to 50 μm, more preferably 2 μm to 30 μm, and even more preferably 2 μm to 20 μm.

[0052] The above intermediate layer may contain any suitable additive as required. Examples of the additive include a crosslinking agent, tackifier, plasticizer (e.g., trimellitic acid ester plasticizer, pyromellitic acid ester plasticizer), pigment, dye, filler, antioxidant, conductive agent, ultraviolet absorber, light stabilizer, peeling regulator, softening agent, surfactant, flame retardant, antioxidant, solvent, and the like.

[0053] C. Manufacturing method of the gas adsorption sheet The above gas adsorption sheet can be produced by any suitable method. In one embodiment, the above gas adsorption sheet is produced by coating (applying and drying) a composition for forming a gas adsorption layer containing the above binder resin and gas adsorption particles on a heat-resistant substrate. By forming a gas adsorption layer by coating, a gas adsorption sheet excellent in the dispersibility of gas adsorption particles and excellent in gas adsorption performance can be obtained.

[0054] In addition to the binder resin and gas adsorption particles, the above composition for forming a gas adsorption layer may further contain any suitable additive. Examples of the additive include a crosslinking agent, tackifier, plasticizer (e.g., trimellitic acid ester plasticizer, pyromellitic acid ester plasticizer), pigment, dye, filler, antioxidant, conductive agent, ultraviolet absorber, light stabilizer, peeling regulator, softening agent, surfactant, flame retardant, antioxidant, and the like. Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, amine-based crosslinking agents, and the like. Among them, isocyanate-based crosslinking agents or epoxy-based crosslinking agents are preferably used. Also, the composition for forming a gas adsorption layer may contain a solvent such as toluene or ethyl acetate.

[0055] Examples of the method for applying the composition for forming the gas adsorption layer include coating methods such as air doctor coating, blade coating, knife coating, reverse coating, transfer roll coating, gravure roll coating, kiss coating, cast coating, spray coating, slot orifice coating, calendar coating, electrodeposition coating, dip coating, die coating; printing methods such as relief printing methods such as flexographic printing, intaglio printing methods such as direct gravure printing method, offset gravure printing method, lithographic printing methods such as offset printing method, and stencil printing methods such as screen printing method.

[0056] D. Cover film In one embodiment, the cover film includes a base material and an adhesive layer disposed on at least one side of the base material.

[0057] In one embodiment, the cover film is detachably disposed. In one embodiment, the cover film is detachable from the gas adsorption sheet after heat drying at 110 ° C for 3 hours. Such a cover film can control the peelability, for example, by adjusting the adhesive strength of the cover film according to the composition of the adhesive layer and the like.

[0058] The adhesive strength of the cover film to the stainless steel plate at 25 ° C is preferably 0.05 N / 20 mm to 5 N / 20 mm, more preferably 0.1 N / 20 mm to 3 N / 20 mm, still more preferably 0.15 N / 20 mm to 2 N / 20 mm, and even more preferably 0.15 N / 20 mm to 1 N / 20 mm.

[0059] In one embodiment, the cover film is laminated to be peelable from the gas adsorption sheet. After drying the gas adsorption sheet with the cover film at 130°C for 3 hours under a reduced pressure of -100 kPa, the peel strength when peeling the cover film from the gas adsorption sheet is preferably 0.01 N / 50 mm to 5 N / 50 mm, more preferably 0.02 N / 50 mm to 3 N / 50 mm, and even more preferably 0.05 N / 50 mm to 2.5 N / 50 mm. If it is within such a range, it is possible to obtain a cover film that can be peeled while preventing damage to the gas absorption layer. The above peel strength can be measured by a method according to JIS Z 0237:2000. That is, the peel strength is measured by peeling the cover film of the gas adsorption sheet with the cover film from the gas adsorption sheet under the conditions of a measurement temperature of 25°C, a peel angle of 180°, and a peel speed (tensile speed) of 300 mm / min.

[0060] D-1. Substrate The above-mentioned substrate can be composed of any suitable material. The substrate can use various sheet-like materials, such as, for example, resin films, paper, cloth, non-woven fabrics, metal foils, or plastic laminates thereof, laminates of plastics, etc. Among them, from the viewpoints of handleability and cost, resin films are most preferred. As the material constituting the resin film, it can be selected as necessary from the viewpoints of strength, heat resistance, etc. For example, olefin resins having α-olefins such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, ethylene-vinyl acetate copolymer (EVA) as monomer components; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT); polyvinyl chloride (PVC); polyphenylene sulfide (PPS); amide resins such as polyamide (nylon), wholly aromatic polyamide (aramid); polyether ether ketone (PEEK), polyimide, polyetherimide, polystyrene, acrylic resin, etc. These materials can be used alone or in combination of two or more. Also, as the plastic film, any of an unstretched film, a uniaxially oriented film, and a biaxially oriented film may be used. Further, these films may be laminated films composed of two or more film layers, or from the viewpoint of handleability, a film added with a lubricant such as inert particles may be used as appropriate.

[0061] The thickness of the above-mentioned substrate is preferably 200 μm or less, more preferably 1 μm to 200 μm, still more preferably 5 μm to 100 μm, particularly preferably 10 μm to 100 μm, particularly preferably 20 μm to 100 μm, and most preferably 30 μm to 100 μm. Within such a range, floating when in roll shape can be prevented, and a gas adsorption sheet with a cover film excellent in workability can be obtained.

[0062] The moisture permeability of the above-mentioned substrate is preferably 500 g / m 2 ·24 hr or less, more preferably 100 g / m 2· It is 24 hours or less. The moisture permeability can be determined in accordance with the moisture permeability test (cup method) of JIS Z0208.

[0063] The above-mentioned substrate may be surface-treated. Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, ionization radiation treatment, coating treatment with an undercoat agent, etc.

[0064] D-2. Adhesive layer The thickness of the above-mentioned adhesive layer is preferably 30 μm or less, more preferably 20 μm or less, and still more preferably 10 μm or less. The lower limit of the adhesive layer thickness is, for example, 1 μm (preferably 0.5 μm).

[0065] The above-mentioned adhesive layer contains any suitable adhesive. As the adhesive, any suitable adhesive can be used as long as the effects of the present invention can be obtained. As the above-mentioned adhesive, for example, a pressure-sensitive adhesive can be used.

[0066] Examples of the pressure-sensitive adhesive include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, styrene-diene block copolymer adhesives, etc. Among them, acrylic adhesives or rubber adhesives are preferred, and acrylic adhesives are more preferred. Note that the above-mentioned adhesives may be used alone or in combination of two or more. In one embodiment, from the viewpoint of ultraviolet absorption, an adhesive containing a base polymer having an aromatic ring and / or a double bond is used. From this point as well, acrylic adhesives can be preferably used.

[0067] Examples of the acrylic pressure-sensitive adhesive include an acrylic pressure-sensitive adhesive based on an acrylic polymer (homopolymer or copolymer) using one or more (meth)acrylic acid alkyl esters as monomer components. Specific examples of the (meth)acrylic acid alkyl ester include (meth)acrylic acid methyl, (meth)acrylic acid ethyl, (meth)acrylic acid propyl, (meth)acrylic acid isopropyl, (meth)acrylic acid butyl, (meth)acrylic acid isobutyl, (meth)acrylic acid s-butyl, (meth)acrylic acid t-butyl, (meth)acrylic acid pentyl, (meth)acrylic acid hexyl, (meth)acrylic acid heptyl, (meth)acrylic acid octyl, (meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid isooctyl, (meth)acrylic acid nonyl, (meth)acrylic acid isononyl, (meth)acrylic acid decyl, (meth)acrylic acid isodecyl, (meth)acrylic acid undecyl, (meth)acrylic acid dodecyl, (meth)acrylic acid tridecyl, (meth)acrylic acid tetradecyl, (meth)acrylic acid pentadecyl, (meth)acrylic acid hexadecyl, (meth)acrylic acid heptadecyl, (meth)acrylic acid octadecyl, (meth)acrylic acid nonadecyl, (meth)acrylic acid eicosyl, and other (meth)acrylic acid C1-20 alkyl esters. Among them, (meth)acrylic acid alkyl esters having a linear or branched alkyl group with 4 to 18 carbon atoms can be preferably used.

[0068] The above acrylic polymer may, if necessary, contain units corresponding to other monomer components copolymerizable with the above alkyl (meth)acrylate for the purpose of modifying cohesion, heat resistance, crosslinkability, etc. Examples of such monomer components include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid; acid anhydride monomers such as maleic anhydride, itaconic anhydride; hydroxyl group-containing monomers such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl methacrylate; sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid; (N-substituted) amide-based monomers such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methylolpropane (meth)acrylamide; aminoalkyl (meth)acrylate-based monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate; alkoxyalkyl (meth)acrylate-based monomers such as methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate; maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide; itaconimide-based monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, N-laurylitaconimide;Succinimide-based monomers such as N-(meth)acryloyloxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, N-(meth)acryloyl-8-oxyoctamethylene succinimide; vinyl-based monomers such as vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methyl vinylpyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine, N-vinyl carboxylic acid amides, styrene, α-methylstyrene, N-vinyl caprolactam; cyanoacrylate monomers such as acrylonitrile, methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth)acrylate; glycol-based acrylic ester monomers such as (meth)acrylic acid polyethylene glycol, (meth)acrylic acid polypropylene glycol, (meth)acrylic acid methoxyethylene glycol, (meth)acrylic acid methoxypolypropylene glycol; acrylic acid ester monomers having a heterocyclic ring, a halogen atom, a silicon atom, etc. such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate; polyfunctional monomers such as hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy acrylate, polyester acrylate, urethane acrylate; olefin-based monomers such as isoprene, butadiene, isobutylene; vinyl ether-based monomers such as vinyl ether, etc. These monomer components may be used alone or in combination of two or more.;

[0069] In one embodiment, in the base polymer (for example, an acrylic polymer), the content ratio of the structural units derived from the organic acid monomer (for example, a (meth)acrylic acid group-containing monomer, a carboxyl group-containing monomer) is preferably 0.5 parts by weight or less, more preferably 0.3 parts by weight or less, based on 100 parts by weight of the base polymer. Within such a range, a cover film that is difficult to break the gas adsorption layer of the gas adsorption sheet can be obtained when peeling the gas adsorption sheet. In particular, when using surface-treated (preferably, coupling-treated) gas adsorption particles, such an effect becomes remarkable. In one embodiment, an acrylic polymer that does not contain structural units derived from the organic acid monomer is used.

[0070] In one embodiment, in the base polymer (for example, an acrylic polymer), the content ratio of the structural units derived from the nitrogen-containing monomer is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, based on 100 parts by weight of the base polymer. Within such a range, a cover film that is difficult to break the gas adsorption layer of the gas adsorption sheet can be obtained when peeling the gas adsorption sheet.

[0071] The pressure-sensitive adhesive may contain any suitable additive as needed. Examples of the additive include a crosslinking agent, a tackifier (for example, a rosin-based tackifier, a terpene-based tackifier, a hydrocarbon-based tackifier, etc.), a plasticizer (for example, a trimellitic acid ester-based plasticizer, a pyromellitic acid ester-based plasticizer), a pigment, a dye, an antioxidant, a conductive material, an antistatic agent, a light stabilizer, a release regulator, a softening agent, a surfactant, a flame retardant, an antioxidant, an ultraviolet absorber, particles, etc.

[0072] Examples of the crosslinking agent include, for example, isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, as well as urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, amine-based crosslinking agents, and the like. Among them, an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferably used. In one embodiment, from the viewpoint of ultraviolet absorption, a crosslinking agent having an aromatic ring and / or a double bond (for example, an aromatic isocyanate-based crosslinking agent) is used.

[0073] Specific examples of the isocyanate-based crosslinking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, and isophorone diisocyanate; aromatic isocyanates such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate; isocyanate adducts such as trimethylolpropane / tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name "Coronate HL"), and isocyanurate form of hexamethylene diisocyanate (manufactured by Tosoh Corporation, trade name "Coronate HX"); and the like. The content of the isocyanate-based crosslinking agent can be set to any appropriate amount according to the desired adhesive strength, and is typically 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the base polymer.

[0074] Examples of the epoxy crosslinking agent include N,N,N’,N’-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-glycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Company, trade name “Tetrad C”), 1,6-hexanediol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name “Epolite 1600”), neopentyl glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name “Epolite 1500NP”), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name “Epolite 40E”), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name “Epolite 70P”), polyethylene glycol diglycidyl ether (manufactured by NOF Corporation, trade name “Epole E-400”), polypropylene glycol diglycidyl ether (manufactured by NOF Corporation, trade name “Epole P-200”), sorbitol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name “Denacol EX-611”), glycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name “Denacol EX-314”), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation, trade name “Denacol EX-512”), sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcin diglycidyl ether, bisphenol-S-diglycidyl ether, epoxy resins having two or more epoxy groups in the molecule, and the like. The content of the epoxy crosslinking agent can be set to any appropriate amount according to the desired adhesive strength, and is typically 0.01 to 10 parts by weight, more preferably 0.03 to 5 parts by weight, based on 100 parts by weight of the base polymer.

[0075] As the above-mentioned tackifier, for example, rosin-based resins (such as rosin ester resins), terpene-based resins (such as terpene phenol copolymers (terpene-modified phenol resins), hydrogenated terpene resins, etc.), coumarone indene-based resins, alicyclic saturated hydrocarbon-based resins, petroleum-based resins (such as hydrocarbon-based petroleum resins such as aliphatic / aromatic copolymer-based petroleum resins, aromatic-based petroleum resins, etc.), phenolic resins, etc. can be mentioned. In one embodiment, from the viewpoint of ultraviolet absorption, a crosslinking agent having an aromatic ring and / or a double bond (for example, a rosin-based resin) is used. The content of the tackifier can be set to any appropriate amount according to the desired adhesive strength, and is typically 1 part by weight to 50 parts by weight, more preferably 10 parts by weight to 30 parts by weight, based on 100 parts by weight of the base polymer.

Examples

[0076] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. The evaluation methods in the examples are as follows. Also, in the examples, unless otherwise specified, "parts" and "%" are based on weight.

[0077] (1) Cover film peel strength (peeling force of the cover film from the gas adsorption layer) After drying at 130°C for 3 hours under a reduced pressure of -100 kPa, the cover film was peeled from the gas adsorption layer of the gas adsorption sheet with the cover film, and the peel strength was measured. Test speed: 300 mm / min Peeling angle: 180 degrees Measurement temperature: 25°C

[0078] (2) Cover film peelability The failure mode during the cover film peeling test was evaluated. 〇: Peeling is possible at the interface between the cover film and the gas adsorption layer △: The surface layer of the gas adsorption layer moves to the cover film side ×: All of the gas adsorption layer moves to the cover film side

[0079] (3) Gas adsorption layer strength After drying at 130 °C for 3 hours under a reduced pressure of -100 kPa, the cover film was peeled off from the gas adsorption sheet (1) with a cover film, and No. 31B manufactured by Nitto Denko Corporation was bonded to the exposed surface of the gas adsorption layer, and evaluated by its peel strength. Bonding conditions: Bonded once back and forth with a 2 kg roller in an environment of 25 °C Test speed: 300 mm / min Peel angle: 180 degrees Measurement temperature: 25 °C

[0080] (4) Heat resistance The state of the gas adsorption sheet after drying at 130 °C for 3 hours under a reduced pressure of -100 kPa was confirmed. 〇: The form of the sheet can be maintained ×: The form of the sheet cannot be maintained

[0081] (5) Adhesion of gas adsorption layer During the measurement of the gas adsorption layer strength in (3) above, the failure mode was evaluated. 〇: Cohesive failure mode of gas adsorption layer ×: Anchorage failure mode of gas adsorption layer

[0082] (6) Processability The gas adsorption sheet with a cover film was punched using a Thomson blade type (size: 5 mm × 20 mm, blade thickness: 0.7 mm, R: 0.2), and the state of the gas adsorption sheet after punching was evaluated. 〇: No chipping of the gas adsorption layer △: No chipping of the gas adsorption layer, but there is lifting and peeling of the cover film ×: There is chipping of the gas adsorption layer.

[0083] (7) Moisture resistance The gas adsorption sheet with a cover film dried at 110 °C for 3 hours under a reduced pressure of -100 kPa in a dry room with a dew point temperature of -50 °C and a room temperature of 23 °C was stored in the dry room, and the change in moisture content due to moisture absorption was measured. 〇: The moisture content could be maintained at 1% or less for 8 hours or more in the dry room ×: The moisture content could not be maintained at 1% or less for 8 hours in the dry room Moisture content measurement method (Karl Fischer method) Moisture content: AQ-2100 manufactured by HIRANUMA

[0084] (8) Adhesion of cover film The obtained cover film (1) was bonded to a SUS304BA plate, and the peel strength at the time of peeling was evaluated. Bonding conditions: Bonded with a 2 kg roller in one round trip at 25°C Test speed: 300 mm / min Peel angle: 180 degrees Peel angle: 180 degrees Measurement temperature: 25°C

[0085] (9) Handling property The defects when winding the gas adsorption sheet with a cover film around a 3-inch core made of ABS resin were evaluated. 〇: No problem ×: The absorption layer is likely to fall off, shrink thermally, or the gas absorption layer is damaged during transportation

[0086] (10) Hydrogen sulfide gas adsorption evaluation The hydrogen sulfide gas adsorption property of the gas adsorption sheet with a cover film was evaluated using the following equipment and evaluation method. Test equipment 1: Tedlar bag (10L for test gas enclosure) ※ hereinafter referred to as bag 2: Detection tube (type 4HM, 4M, 4L manufactured by Gastec) 3: Constant temperature bath (type FMU-263I manufactured by Fukushima Galilei) 4: Quantitative pump for air enclosure (type MP-Σ300NII manufactured by Shibata Science) 5: Electronic balance (type ATX224 manufactured by Shimadzu Corporation) 6: Hydrogen sulfide cylinder (purity 99.9% manufactured by Sumitomo Chemical) 7: Air cylinder (grade G2 manufactured by Taiyo Nippon Sanso) Evaluation method: Static method 1: Under atmospheric pressure, the material was dried at 130°C for 3 hours. 2: Using an electronic balance, the weighed sample was put into a bag and sealed, and the residual air in the bag was exhausted. 3: A predetermined amount of air was introduced into the bag using a metering pump. 4: Hydrogen sulfide gas was injected into the bag using a gas-tight syringe to adjust a test gas with a predetermined concentration (340 ppm). 5: The bag was left standing in a thermostatic chamber adjusted to a predetermined temperature and humidity (25°C, 0% RH). 6: After a predetermined time (24 hours) had elapsed, the bag was taken out, and the residual concentration inside the bag was measured using a detector tube.

[0087] [Production Example 1] Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler were charged 2-ethylhexyl acrylate / ethyl acrylate / methyl methacrylate / hydroxyethyl acrylate (30 parts by weight / 70 parts by weight / 5 parts by weight / 4 parts by weight), 0.2 part by weight of benzoyl peroxide as an initiator, and 244 parts by weight of toluene. While gently stirring, nitrogen gas was introduced, and the liquid temperature inside the flask was maintained at around 60°C to carry out a polymerization reaction for about 6 hours to obtain a resin composition (1) containing an acrylic copolymer (1).

[0088] [Production Example 2] Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler were charged 2-ethylhexyl acrylate / hydroxyethyl acrylate (100 parts by weight / 4 parts by weight), 0.2 part by weight of an initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate. While gently stirring, nitrogen gas was introduced, and the liquid temperature inside the flask was maintained at around 60°C to carry out a polymerization reaction for about 6 hours to obtain a resin composition (2) containing an acrylic copolymer (2).

[0089] [Production Example 3] Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 99 parts by weight of butyl acrylate / 1 part by weight of 4-hydroxybutyl acrylate, 0.2 parts by weight of an initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate were charged. While gently stirring, nitrogen gas was introduced, and the liquid temperature in the flask was maintained at around 60 °C, and a polymerization reaction was carried out for about 6 hours to obtain a resin composition (3) containing an acrylic copolymer (3).

[0090] [Production Example 4] Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 97 parts by weight of butyl acrylate / 3 parts by weight of 4-hydroxybutyl acrylate / 0.2 parts by weight of acrylic acid, 0.2 parts by weight of an initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate were charged. While gently stirring, nitrogen gas was introduced, and the liquid temperature in the flask was maintained at around 60 °C, and a polymerization reaction was carried out for about 6 hours to obtain a resin composition (4) containing an acrylic copolymer (4).

[0091] [Production Example 5] Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 95 parts by weight of 2-ethylhexyl acrylate / 5 parts by weight of acrylic acid, 0.2 parts by weight of an initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate were charged. While gently stirring, nitrogen gas was introduced, and the liquid temperature in the flask was maintained at around 60 °C, and a polymerization reaction was carried out for about 6 hours to obtain a resin composition (5) containing an acrylic copolymer (5).

[0092] [Production Example 6] Production of a heat-resistant substrate with an intermediate layer To a resin composition (5) containing 100 parts by weight of an acrylic copolymer (5), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E") and ethyl acetate were added to adjust a composition (1) for forming an intermediate layer with a base of 18%. The obtained composition (1) for forming an intermediate layer was coated on a heat-resistant substrate (a polyimide film, manufactured by Toray DuPont Co., Ltd., trade name "Kapton 100H", thickness: 25 μm) so that the thickness after drying was 10 μm to obtain a heat-resistant substrate (1) with an intermediate layer.

[0093] [Production Example 7] Surface Treatment Method of Gas Adsorbing Particles Into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a cooler, 100 parts by weight of Kesmon NS-20C (manufactured by Toagosei Co., Ltd.) as gas adsorbing particles, 4 parts by weight of KBM-4803 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent, 150 parts by weight of tetrahydrofuran, and 1.3 parts by weight of distilled water were charged. While gently stirring, nitrogen gas was introduced, and the liquid temperature in the flask was maintained at around 60°C to carry out a coupling reaction for about 6 hours to obtain surface-treated particles (1).

[0094] [Production Example 8] Production of Cover Film (1) To a resin composition (3) containing 100 parts by weight of an acrylic copolymer (3), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E") and ethyl acetate were added to adjust a composition (1) for forming an adhesive layer with a base of 15%. The composition (1) for forming an adhesive layer was applied onto a polyester film (manufactured by Toray Industries, Inc., trade name "Lumirror S10") with a thickness of 75 μm so that the thickness after drying would be 10 μm to obtain a cover film (1).

[0095] [Production Example 9] Production of Cover Film (2) A cover film (2) was obtained in the same manner as in Production Example 8, except that the coating thickness of the composition (1) for forming an adhesive layer was 20 μm.

[0096] [Production Example 10] Production of Cover Film (3) To a resin composition (4) containing 100 parts by weight of an acrylic copolymer (4), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E") and ethyl acetate were added to adjust a composition (2) for forming an adhesive layer with a base of 15%. The composition (2) for forming an adhesive layer was applied onto a polyester film (manufactured by Toray Industries, Inc., trade name "Lumirror S10") with a thickness of 75 μm so that the thickness after drying would be 10 μm to obtain a cover film (3).

[0097] [Production Example 11] Production of Cover Film (4) A cover film (4) was obtained in the same manner as in Production Example 8, except that the thickness of the polyester film was 50 μm.

[0098] [Production Example 12] Production of Cover Film (5) A cover film (5) was obtained in the same manner as in Production Example 8, except that the thickness of the polyester film was 25 μm.

[0099] [Production Example 13] Production of Cover Film (6) To the resin composition (1) containing 100 parts by weight of the acrylic copolymer (1), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E") and ethyl acetate were added to prepare a pressure-sensitive adhesive layer-forming composition (3) with a base of 15%. The pressure-sensitive adhesive layer-forming composition (3) was applied onto a polyester film (manufactured by Toray Industries, Inc., trade name "Lumirror S10") with a thickness of 50 μm so that the thickness after drying was 5 μm, to obtain a cover film (6).

[0100] [Example 1] To the resin composition (1) containing 100 parts by weight of the acrylic copolymer (1), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E"), ethyl acetate, and 900 parts by weight of hydrogen sulfide gas adsorbing particles (copper ion-supported silicate manufactured by Toagosei Co., Ltd., trade name "KESMON NS-20C", average primary particle diameter D50: 10 μm or less) were added to prepare a gas adsorbing layer-forming composition (1) with a base of 50%. The obtained gas adsorbing layer-forming composition (1) was applied onto a release-treated film (manufactured by Fuji Photo Film Co., Ltd., trade name "CA0", thickness: 75 μm) so that the thickness after drying was 60 μm, to obtain a gas adsorbing layer (1). The obtained gas adsorbing layer (1) was transferred to the intermediate layer of the heat-resistant base material (1) with an intermediate layer to obtain a gas adsorbing sheet (1). The cover film (1) was attached to the gas adsorbing layer of the gas adsorbing sheet (1) to obtain a gas adsorbing sheet with a cover film (1). The obtained gas adsorbing sheet with a cover film (1) was subjected to the above evaluation. The results are shown in Table 1.

[0101] [Examples 2 to 6] A gas adsorption sheet with a cover film was obtained in the same manner as in Example 1, except that the resin composition constituting the gas adsorption layer, the blending amount of hydrogen sulfide gas adsorption particles, the thickness of the gas adsorption layer, and the type of the cover film were as shown in Table 1. The obtained gas adsorption sheet (1) with a cover film was subjected to the above evaluation. The results are shown in Table 1.

[0102] [Comparative Example 1] To a resin composition (3) containing 100 parts by weight of an acrylic copolymer (3), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E"), ethyl acetate, and 900 parts by weight of hydrogen sulfide gas adsorption particles (copper ion-supported silicate manufactured by Toagosei Co., Ltd., trade name "Kesmon NS-20C", average primary particle diameter D50: 10 μm or less) were added to prepare a composition for forming a gas adsorption layer with a base of 50%. The composition for forming a gas adsorption layer was applied onto a heat-resistant base material (polyimide film, manufactured by Toray DuPont Co., Ltd., trade name "Kapton 100H", thickness: 25 μm) so that the thickness after drying would be 10 μm to obtain a gas adsorption sheet. The obtained gas adsorption sheet was subjected to the above evaluation. The results are shown in Table 2.

[0103] [Comparative Example 2] To a resin composition (3) containing 100 parts by weight of an acrylic copolymer (3), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E"), ethyl acetate, and 10 parts by weight of hydrogen sulfide gas adsorption particles (copper ion-supported silicate manufactured by Toagosei Co., Ltd., trade name "Kesmon NS-20C", average primary particle diameter D50: 10 μm or less) were added to prepare a composition for forming a gas adsorption layer with a base of 50%. The obtained composition for forming a gas adsorption layer was applied onto a release-treated film (manufactured by Fujicco Co., Ltd., trade name "CA0", thickness: 75 μm) so that the thickness after drying would be 80 μm to obtain a gas adsorption layer. The obtained gas adsorption layer was transferred to the intermediate layer of a heat-resistant base material (1) with an intermediate layer to obtain a gas adsorption sheet.

[0104] [Comparative Example 3] To a resin composition (3) containing 100 parts by weight of an acrylic copolymer (3), 3 parts by weight of an isocyanate crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name "Takenate D-101E"), ethyl acetate, and 250 parts by weight of hydrogen sulfide gas adsorbing particles (copper ion-supported silicate manufactured by Toagosei Co., Ltd., trade name "KESMON NS-20C", average primary particle diameter D50: 10 μm or less) were added to prepare a composition for forming a gas adsorption layer with a base of 50%. The obtained composition for forming a gas adsorption layer was applied onto a release-treated film (manufactured by Fujicopier Co., Ltd., trade name "CA0", thickness: 75 μm) so that the thickness after drying would be 80 μm to obtain a gas adsorption layer. The obtained gas adsorption layer was transferred to the intermediate layer of a heat-resistant base material (1) with an intermediate layer to obtain a gas adsorption sheet.

[0105] [Comparative Example 4] A gas adsorption sheet was obtained in the same manner as in Comparative Example 2, except that 900 parts by weight of molecular sieve 5A (manufactured by Union Showa Co., Ltd.) was used instead of 10 parts by weight of hydrogen sulfide gas adsorbing particles (copper ion-supported silicate manufactured by Toagosei Co., Ltd., trade name "KESMON NS-20C", average primary particle diameter D50: 10 μm or less).

[0106]

Table 1

[0107]

Table 2

Industrial Applicability

[0108] The gas adsorption sheet of the present invention can be suitably used as a gas adsorbent for non-aqueous secondary batteries.

Explanation of Symbols

[0109] 10 Heat-resistant base material 20 Gas adsorption layer 30 Intermediate layer 110 Gas adsorption sheet 120 Cover film 100 Gas Adsorption Sheet with Cover Film

Claims

1. A gas adsorption sheet for a secondary battery, comprising a heat-resistant substrate and a gas adsorption layer disposed on at least one side of the heat-resistant substrate, and a cover film disposed on the side of the gas adsorption layer opposite to the heat-resistant substrate, wherein the gas adsorption layer comprises a binder resin and gas adsorption particles composed of an inorganic porous material having pores, which can adsorb gas, A gas adsorption sheet for a secondary battery with a cover film.

2. The gas adsorption sheet for a secondary battery with a cover film according to claim 1, further comprising an intermediate layer between the heat-resistant substrate and the gas adsorption layer.

3. The gas adsorption particles are a composite of at least one metal salt selected from copper, zinc, manganese, cobalt and nickel and a silicate, The pore volume of the gas adsorption particles is preferably 0.3 ml / g to 0.5 ml / g, The gas adsorption sheet for a secondary battery with a cover film according to claim 1.

4. The gas adsorption sheet for a secondary battery with a cover film according to claim 1, wherein the gas adsorption particles have a surface treated with silicone.

5. The gas adsorption sheet for a secondary battery with a cover film according to claim 4, wherein the silicone has an ethoxysilane group or a methoxysilane group.

6. The gas adsorption sheet for a secondary battery with a cover film according to claim 4, wherein the silicone is a silane coupling agent containing an epoxy group or an amino group.

7. The gas adsorption sheet for a secondary battery with a cover film according to claim 4, wherein the silicone is an alkoxysilane or an organosilazane compound.

8. The gas adsorption sheet for a secondary battery with a cover film according to claim 1, wherein the binder resin is an acrylic resin.

9. The binder resin contains a structural unit derived from an alkyl (meth)acrylate, The gas adsorption sheet for a secondary battery with a cover film according to claim 6, wherein the alkyl (meth)acrylate has a linear or branched alkyl group having 4 to 12 carbon atoms.

10. The gas adsorption sheet for a secondary battery with a cover film according to claim 1, wherein the binder resin is butyl rubber, isoprene rubber, polyisobutylene rubber, ethylene propylene rubber or a silicone resin.

11. The cover film-attached gas adsorption sheet for a secondary battery according to claim 1, wherein the content ratio of the gas adsorption particles is 10 parts by weight to 90 parts by weight with respect to 100 parts by weight of the gas adsorption sheet for a secondary battery.

12. The cover film-attached gas adsorption sheet for a secondary battery according to claim 1, wherein the material constituting the heat-resistant base material is polyamideimide, polyetherimide, polyphenylene sulfide, polyethylene naphthalate, polyimide, or polyetheretherketone.

13. The cover film-attached gas adsorption sheet for a secondary battery according to claim 1, wherein the cover film includes a base material and an adhesive layer disposed on at least one side of the base material.

14. The adhesive layer is formed from an adhesive containing a base polymer, and the content ratio of the structural unit derived from the organic acid monomer is preferably 0.5 part by weight or less with respect to 100 parts by weight of the base polymer. The cover film-attached gas adsorption sheet for a secondary battery according to claim 13.

15. The cover film-attached gas adsorption sheet for a secondary battery according to claim 13, wherein the cover film is peelable.

16. An all-solid-state secondary battery using the gas adsorption sheet according to claim 1 inside a battery case.

17. An all-solid-state secondary battery using a sulfide-based solid electrolyte and using the gas adsorption sheet according to claim 1 inside a battery case.

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