Gas absorbing sheet for secondary battery with cover film

Abstract

Provided is a gas adsorption sheet that can preferably adsorb sulfur-based gases. A gas adsorption sheet for a secondary battery according to an embodiment of the present application has: a gas adsorption sheet for a secondary battery that includes 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 the heat-resistant substrate; and the gas adsorption layer includes: a binder resin and a gas adsorption particle composed of an inorganic porous material having pores and capable of adsorbing a gas.

Description

Technical Field

[0001] This invention relates to a gas adsorption sheet for secondary batteries with a covering film. Background Technology

[0002] In recent years, research on all-solid-state batteries has been advancing as a type of rechargeable battery with high energy density. All-solid-state batteries offer excellent safety because they do not use flammable organic solvents, and also possess advantages such as resistance to electrolyte degradation during rapid charging and stable operation at high temperatures. From the perspective of output current, these all-solid-state batteries utilize sulfide-based solid electrolytes.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-187855 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] However, in all-solid-state batteries using sulfide-based solid electrolytes, if the sulfide-based solid electrolyte comes into contact with moisture, sulfide gases such as hydrogen sulfide are generated, posing safety problems due to gas leakage. This invention addresses this problem by providing a gas adsorption sheet capable of preferably adsorbing sulfide gases.

[0008] Solution for solving the problem

[0009] [1] The gas adsorption sheet for secondary batteries with a cover film according to an embodiment of the present invention comprises: a gas adsorption sheet for secondary batteries, which includes 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; the gas adsorption layer includes: an adhesive resin and gas adsorption particles, wherein the gas adsorption particles are composed of an inorganic porous material having fine pores and are capable of adsorbing gas.

[0010] [2] The gas adsorption sheet for secondary batteries with a covering film as described in [1] above may further include an intermediate layer disposed between the heat-resistant substrate and the gas adsorption layer.

[0011] [3] The gas adsorption sheet for secondary batteries with a covering film as described in [1] or [2] above, wherein the gas adsorption particles may be a composite of a metal salt and a silicate selected from at least one of copper, zinc, manganese, cobalt and nickel, and the pore volume of the gas adsorption particles is preferably 0.3 ml / g to 0.5 ml / g.

[0012] [4] The gas adsorption sheet for secondary batteries with a covering film as described in any of [1] to [3] above, wherein the gas adsorption particles may have a surface treated with organosilicon.

[0013] [5] The gas adsorption sheet for secondary batteries with a covering film as described in [4] above, wherein the organosilicon may have ethoxysilyl or methoxysilyl.

[0014] [6] The gas adsorption sheet for secondary batteries with a covering film as described in [4] above, wherein the organosilicon may be a silane coupling agent containing an epoxy group or an amino group.

[0015] [7] The gas adsorption sheet for secondary batteries with a covering film as described in [4] above, wherein the organosilicon can be an alkoxysilane or an organosilicon azirane compound.

[0016] [8] The gas adsorption sheet for secondary batteries with a covering film as described in any of [1] to [7] above, wherein the adhesive resin may be an acrylic resin.

[0017] [9] In the gas adsorption sheet for secondary batteries with a covering film as described in [8] above, the adhesive resin may contain structural units derived from alkyl methacrylates, and the alkyl methacrylates may have straight-chain or branched alkyl groups having 4 to 12 carbon atoms.

[0018]

[10] The gas adsorption sheet for secondary batteries with a covering film as described in any of [1] to [9] above, wherein the adhesive resin may be butyl rubber, isoprene rubber, polyisobutylene rubber, ethylene propylene rubber or silicone resin.

[0019]

[11] The gas adsorption sheet for secondary batteries with a covering film as described in any of [1] to

[10] above, wherein the content ratio of the gas adsorption particles is 10 to 90 parts by weight relative to 100 parts by weight of the gas adsorption sheet for secondary batteries.

[0020]

[12] The gas adsorption sheet for secondary batteries with a covering film as described in any of [1] to

[11] above, wherein the material constituting the heat-resistant substrate may be polyamide imide, polyether imide, polyphenylene sulfide, polyethylene naphthalate, polyimide or polyether ether ketone.

[0021]

[13] A gas adsorption sheet for a secondary battery with a cover film as described in any of [1] to

[12] above, wherein the cover film may have a substrate and an adhesive layer disposed on at least one side of the substrate.

[0022]

[14] In the gas adsorption sheet for secondary batteries with a covering film as described in

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

[0023]

[15] The gas adsorption sheet for secondary batteries with a covering film as described in any of [1] to

[14] above may also be a cover film that can be peeled off.

[0024]

[16] The all-solid-state secondary battery of the present invention includes a gas adsorption sheet for secondary batteries with a covering film as described in any one of [1] to

[15] above.

[0025]

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

[15] above.

[0026] The effects of the invention

[0027] According to the present invention, a gas adsorption sheet capable of preferably adsorbing sulfide gases can be provided. Attached Figure Description

[0028] Figure 1 This is a schematic cross-sectional view of a gas adsorption sheet for a secondary battery according to one embodiment of the present invention. Detailed Implementation

[0029] A. The overall structure of a gas adsorption sheet for secondary batteries with a covering film.

[0030] Figure 1This is a schematic cross-sectional view of a gas adsorption sheet for secondary batteries with a cover film (hereinafter also simply referred to as a gas adsorption sheet with a cover film) according to an embodiment of the present invention. The gas adsorption sheet 100 with a cover film includes: a gas adsorption sheet for secondary batteries (hereinafter also simply referred to as a gas adsorption sheet) 110, which includes a heat-resistant substrate 10 and a gas adsorption layer 20 disposed on at least one side of the heat-resistant substrate 10; and a cover film 120 disposed on the side of the gas adsorption layer 20 opposite to the heat-resistant substrate 10. The gas adsorption layer includes an adhesive resin and gas adsorption particles. The gas adsorption particles are composed of an inorganic porous material with fine pores. In this specification, gas adsorption particles refer to particles that can adsorb sulfide gases by means of chemisorption, thus exhibiting gas adsorption performance. Hydrogen sulfide can be exemplified as a sulfide gas. In one embodiment, the gas adsorption sheet 110 further includes an intermediate layer 30 between the heat-resistant substrate 10 and the gas adsorption layer 20. By forming the intermediate layer, it is possible to prevent the gas adsorption layer from detaching. In another embodiment, the cover film 120 includes a substrate 41 and an adhesive layer 51 disposed on at least one side of the substrate 41. The adhesive layer 51 can be laminated in a manner facing the gas adsorption layer 20. As long as the effects of the present invention can be obtained, the gas adsorption sheet with the cover film and the gas adsorption sheet can also have any other suitable layers. For example, an adhesive layer (not shown) disposed on one or both sides of the outer surface of the gas adsorption sheet can also be included.

[0031] According to embodiments of the present invention, a gas adsorption sheet with good operability and applicable to various uses can be obtained by dispersing gas adsorption particles in a binder resin to form a gas adsorption layer composed of gas adsorption particles and binder resin, and then sheeting it. Furthermore, by providing a heat-resistant substrate, the effect of improving operability becomes even more significant. Moreover, by using a heat-resistant substrate as the substrate, the gas adsorption sheet can be heated (e.g., heated at 200°C for 24 hours) before use. Heating before use removes unwanted substances adsorbed on the gas adsorption particles, and allows the performance of the gas adsorption particles to be fully utilized during use.

[0032] The aforementioned gas adsorption sheet can be suitable for use as a gas adsorption material in all-solid-state batteries. This gas adsorption sheet is advantageous in that it can absorb even trace amounts of sulfide gases with good absorption rates and minimal re-release.

[0033] Furthermore, the aforementioned gas adsorption sheet with a covering film prevents the gas adsorption layer from detaching or breaking, thereby maximizing its ability to adsorb gas particles. The covering film on the gas adsorption sheet can be peeled off for use as a gas adsorption sheet.

[0034] B. Gas adsorption sheet

[0035] The H2S adsorption capacity of the above-mentioned gas adsorption tablet is preferably 10 mg / g or more, more preferably 30 mg / g or more, further preferably 50 mg / g or more, particularly preferably 80 mg / g or more, and most preferably 100 mg / g or more. Furthermore, the upper limit of the H2S adsorption capacity of the above-mentioned gas adsorption tablet is, for example, 500 mg / g, preferably 800 mg / g, and more preferably 1000 mg / g. The method for determining the H2S adsorption capacity is described below.

[0036] The aforementioned gas adsorption sheet may be adhesive on one or both sides, or it may be a non-adhesive gas adsorption sheet. Examples of adhesive gas adsorption sheets include those with an adhesive gas adsorption layer and those with an adhesive layer disposed on the outermost side of the gas adsorption sheet.

[0037] When the gas adsorption sheet described above has adhesive properties, the adhesion force of the gas adsorption sheet to the stainless steel plate at 23°C is preferably 0.1N / 19mm to 30N / 19mm, more preferably 0.5N / 19mm to 20N / 19mm. If it is within such a range, a gas adsorption sheet suitable for battery applications can be manufactured. In this specification, the term "adhesive force" refers to the adhesive force measured using a method based on JIS Z0237:2000. This measurement is performed as follows: the adhesive tape is applied to the substrate (SUS304BA) by rolling a 2kg roller back and forth once, placed at 25°C for 30 minutes, and then the adhesive tape is peeled off under the conditions of a peel angle of 180° and a peel speed (tension speed) of 300mm / min.

[0038] The thickness of the aforementioned gas adsorption sheet is preferably 10 μm to 1000 μm, more preferably 20 μm to 500 μm, even more preferably 20 μm to 150 μm, even more preferably 20 μm to 120 μm, and particularly preferably 20 μm to 110 μm. Within this range, a gas adsorption sheet with excellent gas adsorption performance and operability can be obtained.

[0039] B-1. Gas Adsorption Layer

[0040] As described above, the gas adsorption layer comprises a binder resin and gas adsorption particles dispersed within the binder resin. In this invention, by employing this configuration, a gas adsorption layer can be formed by coating with a coating liquid containing the binder resin and gas adsorption particles. As a result, a gas adsorption layer with excellent dispersion of gas adsorption particles can be formed, and a gas adsorption sheet with excellent gas adsorption performance can be obtained.

[0041] The thickness of the aforementioned gas adsorption layer is preferably 5 μm to 150 μm, more preferably 5 μm to 100 μm, and even more preferably 10 μm to 80 μm. Within this range, a gas adsorption layer capable of fully utilizing the performance of the gas adsorption particles can be manufactured. Furthermore, a gas adsorption sheet with excellent operability can be obtained.

[0042] (Gas adsorbed particles)

[0043] As described above, gas adsorption particles can adsorb sulfide gases using chemisorption. Chemisorption refers to the adsorption of a target gas through a chemical reaction. The gas adsorption particles are composed of inorganic porous materials with fine pores. In one embodiment, the gas adsorption particles may be a composite of a metal salt and a silicate selected from at least one of copper, zinc, manganese, cobalt, and nickel.

[0044] As the metal (metal ion) constituting the above-mentioned metal salt, copper, zinc, or manganese are preferred, with copper or zinc being more preferred. Using these metals yields a gas adsorption sheet with particularly excellent adsorption properties for sulfide gases. Furthermore, a gas adsorption sheet that allows for easy identification of its use by coloring after gas adsorption can be provided. Examples of acids that form the above-mentioned metal salt include sulfuric acid, hydrochloric acid, and nitric acid.

[0045] The silicate is preferably an alkali metal salt of silicate, more preferably sodium silicate or potassium silicate, and particularly preferably sodium silicate.

[0046] The molar ratio of metal salt to 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.

[0047] In one embodiment, the gas adsorption particles have a surface-treated surface. The surface treatment can be a process to adjust the affinity between the gas adsorption particles and the binder resin. Using gas adsorption particles with a surface-treated surface results in a gas adsorption layer with excellent mechanical strength and resistance to detachment. In the gas adsorption sheet with a cover film provided by laminating a cover film, damage to the gas adsorption layer is particularly preferred when peeling off the cover film during use of the gas adsorption sheet. Furthermore, using gas adsorption particles with a surface-treated surface results in a gas adsorption sheet with excellent processability during cutting. For example, when the gas adsorption sheet is punched using a die such as a Thomson die, damage to the gas adsorption layer can be prevented. The surface-treated surface can be the entire surface of the gas adsorption particle or a portion thereof. Examples of surface treatments include: silane coupling agent treatment, isocyanate compound treatment, thiol compound treatment, acid compound treatment, alcohol compound treatment, epoxy compound treatment, etc. In one embodiment, the surface treatment can be a coupling treatment. If coupled gas adsorption particles are used, the effects of preventing the detachment of the gas adsorption layer and improving processability become significant.

[0048] In one embodiment, gas adsorption particles having a surface treated with organosilicon can be used. In one embodiment, the organosilicon has an ethoxysilyl or methoxysilyl group. Using such an organosilicon allows the formation of a gas adsorption layer with excellent mechanical strength and resistance to detachment. The organosilicon can be a silane coupling agent. This silane coupling agent preferably contains epoxy groups and / or amino groups. Using such a silane coupling agent allows the formation of a gas adsorption layer with excellent mechanical strength and resistance to detachment. The aforementioned gas adsorption particles, i.e., gas adsorption particles surface-treated with organosilicon (silane coupling agent), can be obtained by contacting the silane coupling agent with the surface of the gas adsorption particles, thereby causing organic groups (e.g., hydroxyl groups) present on the surface to react with silanol groups generated by the hydrolysis of the silane coupling agent, or by causing oligomers formed by the condensation of silanol groups to bond to the gas adsorption particles.

[0049] Examples of silane coupling agents include: vinyltrimethoxysilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropyltriethoxysilane, 3-epoxypropoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 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-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, hydrochloride salt of N-(vinylbenzyl)-2-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-isocyanate-propyltriethoxysilane, dithiol triazine propyltriethoxysilane, etc.

[0050] In one embodiment, the organosilicon used may be: alkoxysilanes such as phenyltrimethoxysilane; organosilanes such as hexamethyldisilazane; etc.

[0051] The average particle size (median particle size D50) of the aforementioned gas adsorbed particles is preferably less than 10 μm. If it is within this range, a gas adsorption layer with a large amount of gas adsorption can be formed. The average particle size (median particle size D50) can be measured using a laser diffraction / scattering particle size distribution measuring device.

[0052] The pore volume of the aforementioned 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. Within this range, gas adsorption sheets exhibiting particularly excellent adsorption properties for sulfide gases can be obtained. It should be noted that the pore volume can be determined using the BET method with nitrogen.

[0053] The specific surface area of ​​the gas adsorbed particles is preferably 100 m². 2 / g~3000m 2 / g. If within such a range, gas adsorption particles with excellent gas adsorption performance and mechanical strength can be obtained. Gas adsorption particles with such a large specific surface area are prone to aggregation, but according to the present invention, the gas adsorption particles can be well dispersed to form a gas adsorption layer.

[0054] The H2S adsorption capacity of the gas adsorption particles is preferably 10 mg / g or more, more preferably 30 mg / g or more, even more preferably 50 mg / g or more, particularly preferably 80 mg / g or more, and most preferably 100 mg / g or more. Furthermore, the upper limit of the H2S adsorption capacity of the aforementioned gas adsorption sheet is, for example, 500 mg / g, preferably 800 mg / g, and more preferably 1000 mg / g.

[0055] The content ratio of the aforementioned gas adsorption particles relative to 100 parts by weight of the gas adsorption sheet is preferably 10 to 90 parts by weight, more preferably 30 to 80 parts by weight, and even more preferably 40 to 70 parts by weight. If it is within such a range, a gas adsorption sheet with excellent gas adsorption performance and excellent operability can be obtained.

[0056] The content ratio of the aforementioned gas adsorbent particles relative to 100 parts by weight of the binder resin constituting the gas adsorbent layer is preferably 10 parts by weight to 2000 parts by weight, more preferably 50 parts by weight to 1500 parts by weight, even more preferably 100 parts by weight to 1000 parts by weight, and particularly preferably 280 parts by weight to 1000 parts by weight. Within this range, a gas adsorbent layer in which the gas adsorbent particles are not easily detached can be obtained. Furthermore, a gas adsorbent sheet with excellent gas adsorption performance and operability can be obtained.

[0057] (Adhesive resin)

[0058] As the aforementioned adhesive resin, any suitable resin can be used as long as the effects of the present invention are achieved. Examples of adhesive resins 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; and polyvinyl alcohol resins. In one embodiment, acrylic resins, butyl rubber, or silicone resins are preferably used. Using these resins allows for the formation of a gas adsorption layer with excellent dispersion of gas adsorption particles.

[0059] The aforementioned binder resin preferably has gas permeability. Using a gas-permeable binder resin yields a gas-adsorbing sheet suitable for battery applications. Examples of resins with excellent gas permeability include: acrylic resins, butyl rubber, isoprene rubber, polyisobutylene rubber, ethylene propylene rubber, and other rubber-based resins; silicone resins; urethane resins; epoxy resins; alkyd resins; polyester resins; melamine resins; polyamide resins; and polyimide resins.

[0060] In one embodiment, an acrylic resin can be used as the binder resin. Using an acrylic resin allows for the formation of a gas adsorption layer where the gas adsorption particles are less likely to detach. Furthermore, a gas adsorption layer can be formed that fully utilizes the gas adsorption performance of the gas adsorption particles.

[0061] Examples of acrylic resins include those containing one or more structural units derived from (meth)acrylate alkyl esters. The content ratio of the aforementioned structural units derived from (meth)acrylate alkyl esters relative to 100 parts by weight of the acrylic resin is preferably 50 to 97 parts by weight, more preferably 70 to 94 parts by weight.

[0062] The aforementioned (meth)acrylate alkyl esters are preferably straight-chain or branched alkyl groups having 1 to 24 carbon atoms (more preferably 3 to 20, and even more preferably 6 to 18).

[0063] In one embodiment, the aforementioned (meth)acrylate alkyl ester preferably has a straight-chain or branched alkyl group having 4 to 12 carbon atoms, and more preferably has a straight-chain or branched alkyl group having 6 to 12 carbon atoms. If an acrylic resin having such a (meth)acrylate alkyl ester as the main structural unit is used to form the gas adsorption layer, a gas adsorption sheet in which discoloration and swelling in the electrolyte are suppressed can be obtained.

[0064] Examples of the aforementioned alkyl methacrylates include: methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, eicosyl methacrylate, etc.

[0065] In one embodiment, a branched alkyl methacrylate can be used as the aforementioned alkyl methacrylate. Using a branched alkyl methacrylate allows the formation of a gas adsorption layer capable of fully utilizing the gas adsorption performance of the gas adsorption particles. Alkyl methacrylates with straight-chain alkyl groups and branched alkyl methacrylates can also be used together. Alternatively, a branched alkyl methacrylate can be used alone as the alkyl methacrylate.

[0066] In one embodiment, the content ratio of structural units derived from branched alkyl (meth)acrylates in the above-mentioned acrylic resin is preferably 20 to 100 parts by weight relative to 100 parts by weight of structural units derived from alkyl (meth)acrylates (i.e., 100 parts by weight of the combined amount of straight-chain alkyl (meth)acrylates (including methyl (meth)acrylate and ethyl (meth)acrylate) and branched alkyl (meth)acrylates). More preferably, it is 30 to 100 parts by weight, even more preferably 50 to 100 parts by weight, and particularly preferably 70 to 100 parts by weight.

[0067] Examples of alkyl (meth)acrylates having branched alkyl groups include: isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecanyl (meth)acrylate, stearyl (meth)acrylate, 2-ethylbutyl (meth)acrylate, and 2-methylbutyl (meth)acrylate. Among these, 2-ethylhexyl (meth)acrylate is preferred.

[0068] For the purpose of modifying cohesion, heat resistance, crosslinking, etc., the above-mentioned acrylic resins may also include structural units derived from other monomers capable of copolymerizing with the above-mentioned alkyl methacrylates. Examples of such other monomers include: (meth)acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and other monomers containing carboxyl groups; maleic anhydride, itaconic anhydride, and other monomers containing anhydride groups; 2-hydroxyethylacryloyl phosphate, and other monomers containing phosphate groups; styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamide propanesulfonic acid, (meth)acrylic acid sulfonyl propane, (meth)acryloyloxynaphthalene sulfonic acid, and other monomers containing sulfonic acid groups; (meth)acrylic acid hydroxyethyl acrylate, (meth)acrylic acid hydroxypropyl acrylate, (meth)acrylic acid hydroxybutyl acrylate, (meth)acrylic acid hydroxyhexyl acrylate, (meth)acrylic acid... Hydroxyl octyl ester, hydroxydecyl (meth)acrylate, hydroxylauryl (meth)acrylate, methyl methacrylate (4-hydroxymethylcyclohexyl)methacrylate, and other hydroxyl-containing monomers; (N-substituted) amide monomers such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and N-hydroxymethylpropane (meth)acrylamide; (meth)acrylic acid aminoethyl ester, (meth)acrylic acid N,N-dimethylaminoethyl ester, (meth)acrylic acid tert-butylaminoethyl ester, and other (meth)acrylic acid aminoalkyl ester monomers; (meth)acrylic acid methoxyethyl ester, (meth)acrylic acid ethoxyethyl ester, and other (meth)acrylic acid alkyl ester monomers. Oxyalkyl ester monomers; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimide monomers such as N-methylitconimide, N-ethylitconimide, N-butylitconimide, N-octylitconimide, N-2-ethylhexylitconimide, N-cyclohexylitconimide, and N-laurylitconimide; succinimide monomers such as N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; vinyl acetate, Vinyl monomers such as vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazolium, vinyloxazole, vinylmorpholine, N-vinylcarboxylic amides, styrene, α-methylstyrene, and N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy-containing acrylic monomers such as glycidyl acrylate; diol-based acrylate monomers such as polyethylene glycol acrylate, polypropylene glycol acrylate, methoxyethylene glycol acrylate, and methoxypolypropylene glycol acrylate.Acrylate monomers containing heterocyclic rings, halogen atoms, or silicon atoms, such as tetrahydrofurfuryl methacrylate, fluoromethacrylate, and organosilicon methacrylate; multifunctional monomers such as hexanediol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, neopentyl glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, epoxy acrylate, polyester acrylate, and urethane acrylate; olefin monomers such as isoprene, butadiene, and isobutylene; and vinyl ether monomers such as vinyl ethers. These monomer components can be used alone or in combination of two or more.

[0069] The content of structural units derived from the other monomers mentioned above is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, and even more preferably 1 to 10 parts by weight relative to 100 parts by weight of acrylic resin.

[0070] In one embodiment, the acrylic resin described above does not contain structural units derived from carboxyl-containing monomers such as (meth)acrylic acid. When such an acrylic resin is used, gelation can be prevented and a gas adsorption layer is preferably formed, even though it contains the aforementioned gas adsorption particles.

[0071] The weight-average molecular weight of the above-mentioned acrylic resin is preferably 300,000 to 2,000,000, more preferably 500,000 to 1,500,000. The weight-average molecular weight can be determined using GPC (solvent: THF).

[0072] B-2. Heat-resistant substrate

[0073] In this specification, the term "heat-resistant substrate" refers to a substrate capable of withstanding heating for 24 hours (preferably 24 hours at a temperature of 150°C and a pressure of -100 kPa to 0 kPa). Specifically, it means a substrate whose dimensional change is less than 5% even after heating for 24 hours at a temperature of 150°C and a pressure of -100 kPa (preferably 24 hours at a temperature of 200°C and a pressure of -100 kPa). Furthermore, when the heat-resistant substrate is formed of resin, it means a substrate made of resin with a glass transition temperature of 80°C or higher (preferably 100°C or higher, more preferably 150°C or higher). Furthermore, the so-called "glass transition temperature" refers to the temperature at which the loss tangent (tanδ) peak is observed in the DMA method (stretching method) under the conditions of a heating rate of 5℃ / min, a sample width of 5mm, a chuck distance of 20mm, and a frequency of 10Hz.

[0074] As the material constituting the heat-resistant substrate described above, any suitable material can be used as long as the effects of the present invention are achieved. The heat-resistant substrate is preferably composed of resin. Examples of materials constituting the heat-resistant substrate include polyamide-imide (PAI), polyether-imide (PEI), polyphenylene sulfide (PPS), polyethylene naphthalate (PEN), polyimide (PI), and polyether ether ketone (PEEK). These resins exhibit excellent heat resistance.

[0075] The thickness of the aforementioned 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 this range, a gas adsorption sheet with particularly excellent operability can be obtained.

[0076] B-3. ​​Intermediate Layer

[0077] The aforementioned intermediate layer comprises any suitable resin. Examples of resins forming the intermediate layer include acrylic resins, rubber resins, and silicone resins. Among these, acrylic resins are preferably used. Additionally, an acrylic resin that cures via active energy lines can also be used as an adhesive. The aforementioned adhesive resin can be used as an example of the resin constituting the intermediate layer. In one embodiment, the same resin as the adhesive resin constituting the gas adsorption layer can be used as the resin constituting the intermediate layer. The intermediate layer does not contain gas adsorption particles.

[0078] By forming an intermediate layer, a gas adsorption sheet with a gas adsorption layer that is not easily detached can be obtained.

[0079] The thickness of the aforementioned 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.

[0080] The aforementioned intermediate layer may contain any suitable additives as needed. Examples of such additives include: crosslinking agents, tackifiers, plasticizers (e.g., trimellitate plasticizers, pyromellitic ester plasticizers), pigments, dyes, fillers, anti-aging agents, conductive agents, ultraviolet absorbers, light stabilizers, peel modifiers, softeners, surfactants, flame retardants, antioxidants, solvents, etc.

[0081] C. Manufacturing method of gas adsorption sheet

[0082] The gas adsorption sheet described above can be manufactured by any suitable method. In one embodiment, the gas adsorption sheet is manufactured by coating (applying / drying) a gas adsorption layer forming composition comprising the binder resin and gas adsorption particles onto a heat-resistant substrate. If a gas adsorption layer is formed by coating, a gas adsorption sheet with excellent dispersion of gas adsorption particles and excellent gas adsorption performance can be obtained.

[0083] In addition to the binder resin and gas adsorption particles, the above-mentioned gas adsorption layer forming composition may further include any suitable additives. Examples of additives include: crosslinking agents, tackifiers, plasticizers (e.g., trimellitate-based plasticizers, pyromellitic ester-based plasticizers), pigments, dyes, fillers, anti-aging agents, conductive agents, ultraviolet absorbers, light stabilizers, peel modifiers, softeners, surfactants, flame retardants, antioxidants, etc. Examples of crosslinking agents include: 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, etc. Isocyanate-based crosslinking agents or epoxy-based crosslinking agents are preferred. Furthermore, the gas adsorption layer forming composition may also include solvents such as toluene and ethyl acetate.

[0084] Examples of coating methods for the above-mentioned gas adsorption layer formation composition include: air knife coating, scraper coating, blade coating, reverse coating, conveyor roller coating, gravure roller coating, contact coating (kiss coating), cast coating, spraying, slit coating, calendering coating, electrodeposition coating, dip coating, mold coating, etc.; and printing methods such as flexographic printing, direct gravure printing, offset gravure printing, offset printing, screen printing, etc.

[0085] D. Covering film

[0086] In one embodiment, the cover film includes a substrate and an adhesive layer disposed on at least one side of the substrate.

[0087] In one embodiment, the aforementioned cover film is peelable. In another embodiment, the cover film can be peeled off from the gas adsorption sheet after being heated and dried at 110°C for 3 hours. The peelability of this cover film can be controlled, for example, by adjusting the adhesive strength of the cover film according to the composition of the adhesive layer.

[0088] The adhesion of the aforementioned covering film to the stainless steel plate at 25°C is preferably 0.05N / 20mm to 5N / 20mm, more preferably 0.1N / 20mm to 3N / 20mm, even more preferably 0.15N / 20mm to 2N / 20mm, and even more preferably 0.15N / 20mm to 1N / 20mm.

[0089] In one embodiment, the aforementioned cover film is capable of being peeled off from the gas adsorption sheet. After drying the gas adsorption sheet with the cover film attached at 130°C for 3 hours under reduced pressure of -100 kPa, the peel strength when the cover film is peeled off 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, a cover film capable of peeling off while preventing damage to the gas absorption layer can be produced. The peel strength can be measured using a method based on 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 attached from the gas adsorption sheet under the conditions of a measurement temperature of 25°C, a peel angle of 180°, and a peel speed (stretch speed) of 300 mm / min.

[0090] D-1. Substrate

[0091] The aforementioned substrate can be made of any suitable material. Examples of substrates include resin films, paper, cloth, nonwoven fabrics, metal foils, or various sheet materials such as plastic laminates or laminates of plastics. Among these, resin films are preferred from the perspectives of processability and cost. The materials constituting the resin film can be selected based on factors such as strength and heat resistance. Examples include: olefin resins with α-olefins as monomers, such as polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer (EVA); polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyvinyl chloride (PVC); polyphenylene sulfide (PPS); amide resins such as polyamide (nylon) and fully aromatic polyamide (aramid); polyetheretherketone (PEEK), polyimide, polyetherimide, polystyrene, and acrylic resins. These raw materials can be used individually or in combination of two or more. Furthermore, any type of plastic film, such as unstretched film, uniaxially oriented film, or biaxially oriented film, can be used. Additionally, these films can be laminated films containing two or more film layers, and from a processability perspective, films containing lubricants such as inactive particles can also be appropriately used.

[0092] The thickness of the aforementioned substrate is preferably 200 μm or less, more preferably 1 μm to 200 μm, even more preferably 5 μm to 100 μm, particularly preferably 10 μm to 100 μm, especially preferably 20 μm to 100 μm, and most preferably 30 μm to 100 μm. Within this range, a gas adsorption sheet with a covering film can be obtained that prevents bulging when formed into a roll shape and exhibits excellent workability.

[0093] The moisture permeability of the above-mentioned substrate is preferably 500 g / m³. 2 • Less than 24 hours, preferably 100g / m 2 • Less than 24 hours. The moisture permeability can be determined according to the moisture permeability test (cup method) of JIS Z 0208.

[0094] The aforementioned substrate may also be subjected to surface treatment. Examples of surface treatments include: corona treatment, chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, ionizing radiation treatment, and coating treatment using a primer.

[0095] D-2. Adhesive layer

[0096] The thickness of the adhesive layer is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less. The lower limit of the adhesive layer thickness is, for example, 1 μm (preferably 0.5 μm).

[0097] The adhesive layer described above comprises any suitable adhesive. Any suitable adhesive can be used as the adhesive, as long as the effects of the present invention are achieved. For example, a pressure-sensitive adhesive can be used as the adhesive described above.

[0098] Examples of pressure-sensitive adhesives include acrylic adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, and styrene-diene block copolymer adhesives. Among these, acrylic adhesives or rubber adhesives are preferred, and acrylic adhesives are more preferably used. It should be noted that the above adhesives can be used alone or in combination of two or more. In one embodiment, from the viewpoint of ultraviolet absorption, an adhesive comprising a base polymer having aromatic rings and / or double bonds can be used. From this viewpoint, acrylic adhesives are also preferably used.

[0099] Examples of acrylic adhesives include acrylic adhesives that use acrylic polymers (homopolymers or copolymers) with one or more alkyl methacrylates as monomer components as base polymers. Specific examples of alkyl methacrylates include: methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, isooctyl methacrylate, nonyl methacrylate, isononyl methacrylate, decyl methacrylate, isodecanyl methacrylate, undecyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, tetradecyl methacrylate, pentadecyl methacrylate, hexadecyl methacrylate, heptadecanyl methacrylate, octadecyl methacrylate, nonadecanyl methacrylate, eicosyl methacrylate, and other C1-20 alkyl methacrylates. Alkyl (meth)acrylates having straight-chain or branched alkyl groups having 4 to 18 carbon atoms are preferably used.

[0100] For the purpose of modifying cohesion, heat resistance, crosslinking, etc., the above-mentioned acrylic polymers may also include units corresponding to other monomer components that can copolymerize with the above-mentioned alkyl methacrylates. Examples of such monomer components include: acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and other carboxyl-containing monomers; maleic anhydride, itaconic anhydride, and other anhydride monomers; hydroxyl-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, and methyl (4-hydroxymethylcyclohexyl) methacrylate; styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, and (methyl) Monomers containing sulfonic acid groups, such as acrylamide propanesulfonic acid, sulfonyl propionate (meth)acrylate, and methacryloyloxynaphthalenesulfonic acid; (N-substituted) amide monomers, such as (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, and N-hydroxymethylpropane (meth)acrylamide; (meth)acrylate aminoethyl ester monomers, such as N,N-dimethylaminoethyl ester (meth)acrylate and tert-butylaminoethyl ester (meth)acrylate; (meth)acrylate alkoxyalkyl ester monomers, such as methoxyethyl ester (meth)acrylate and ethoxyethyl ester (meth)acrylate; N - Maleimide monomers such as cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimid monomers such as N-methylitaconimidide, N-ethylitaconimidide, N-butylitaconimidide, N-octylitaconimidide, N-2-ethylhexylitaconimidide, N-cyclohexylitaconimidide, and N-laurylitaconimidide; succinimid monomers such as N-(meth)acryloyloxymethylenesuccinimidide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimidide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimidide; vinyl acetate and vinyl propionate. Vinyl monomers such as N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazolium, vinyloxazole, vinylmorpholine, N-vinylcarboxylic amides, styrene, α-methylstyrene, and N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy-containing acrylic monomers such as glycidyl acrylate; diol-based acrylate monomers such as polyethylene glycol acrylate, polypropylene glycol acrylate, methoxyethylene glycol acrylate, and methoxypolypropylene glycol acrylate.Acrylate monomers containing heterocyclic rings, halogen atoms, or silicon atoms, such as tetrahydrofurfuryl methacrylate, fluoromethacrylate, and organosilicon methacrylate; multifunctional monomers such as hexanediol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, neopentyl glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, epoxy acrylate, polyester acrylate, and urethane acrylate; olefin monomers such as isoprene, butadiene, and isobutylene; and vinyl ether monomers such as vinyl ethers. These monomer components can be used alone or in combination of two or more.

[0101] In one embodiment, the proportion of structural units derived from organic acid monomers (e.g., monomers containing (meth)acrylate groups, monomers containing carboxyl groups) in the base polymer (e.g., an acrylic polymer) is preferably 0.5 parts by weight or less, more preferably 0.3 parts by weight or less, relative to 100 parts by weight of the base polymer. Within this range, a covering film is obtained that is less likely to be damaged when the gas adsorption sheet is peeled off. This effect is particularly significant when using surface-treated (preferably coupled) gas adsorption particles. In one embodiment, an acrylic polymer that does not contain structural units derived from organic acid monomers can be used.

[0102] In one embodiment, the proportion of structural units derived from nitrogen-containing monomers in the base polymer (e.g., an acrylic polymer) is preferably 20 parts by weight or less, more preferably 15 parts by weight or less, relative to 100 parts by weight of the base polymer. Within this range, a covering film is obtained that does not easily damage the gas adsorption layer of the gas adsorption sheet when peeled off.

[0103] The pressure-sensitive adhesives described above may contain any suitable additives as needed. Examples of such additives include: crosslinking agents, tackifiers (e.g., rosin-based tackifiers, terpene-based tackifiers, hydrocarbon-based tackifiers, etc.), plasticizers (e.g., trimellitate-based plasticizers, pyromellitic ester-based plasticizers), pigments, dyes, anti-aging agents, conductive materials, antistatic agents, light stabilizers, peel modifiers, softeners, surfactants, flame retardants, antioxidants, UV absorbers, particles, etc.

[0104] Examples of crosslinking agents include, in addition to isocyanate-based, epoxy-based, melamine-based, and peroxide-based crosslinking agents, urea-based, metal alkoxide-based, metal chelate-based, metal salt-based, carbodiimide-based, oxazoline-based, aziridine-based, and amine-based crosslinking agents. Isocyanate-based or epoxy-based crosslinking agents are preferred. In one embodiment, from the viewpoint of ultraviolet absorption, a crosslinking agent having an aromatic ring and / or double bond (e.g., an aromatic isocyanate-based crosslinking agent) can be used.

[0105] Specific examples of the aforementioned isocyanate-based crosslinking agents 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-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and phenyl diisocyanate; and isocyanate adducts such as trimethylolpropane / toluene 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"). The content of the isocyanate-based crosslinking agent can be set to any suitable amount according to the required adhesive strength, typically 0.1 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of the base polymer.

[0106] Examples of epoxy-based crosslinking agents include: N,N,N',N'-tetraglycidyl-m-phenylenediamine, diglycidyl-aniline, 1,3-bis(N,N-glycidylaminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name "Tetrad C"), 1,6-hexanediol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 1600"), neopentyl glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 1500NP"), ethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 40E"), propylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Epolight 70P"), and polyethylene glycol diglycidyl ether (manufactured by Nippon Oils & Fats Co., Ltd., trade name "EPIOL"). E-400”), polypropylene glycol diglycidyl ether (manufactured by Nippon Yushi Co., Ltd., trade name “EPIOL P-200”), sorbitol polyglycidyl ether (manufactured by Nagase Chemical Co., Ltd., trade name “DENACOL EX-611”), glycerol polyglycidyl ether (manufactured by Nagase Chemical Co., Ltd., trade name “DENACOL EX-314”), pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether (manufactured by Nagase Chemical Co., Ltd., trade name “DENACOL EX-512”), sorbitan anhydride polyglycidyl ether, trimethylolpropane polyglycidyl ether, diglycidyl adipate, diglycidyl phthalate, triglycidyl-tris(2-hydroxyethyl) isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, epoxy resins with two or more epoxy groups in the molecule, etc. The content of the epoxy crosslinking agent can be set to any suitable amount according to the required adhesive strength, typically 0.01 parts by weight to 10 parts by weight, and more preferably 0.03 parts by weight to 5 parts by weight, relative to 100 parts by weight of the base polymer.

[0107] Examples of such tackifiers include: rosin-based resins (e.g., rosin ester resins), terpene-based resins (e.g., terpene-phenol copolymers (terpene-modified phenolic resins), hydrogenated terpene resins), coumarone-indene resins, alicyclic saturated hydrocarbon resins, petroleum-based resins (e.g., aliphatic / aromatic copolymer petroleum resins, aromatic petroleum resins, and other hydrocarbon petroleum resins), and phenolic resins. In one embodiment, from the viewpoint of ultraviolet absorption, a crosslinking agent having aromatic rings and / or double bonds (e.g., rosin-based resins) can be used. The content of the tackifier can be set to any suitable amount according to the desired adhesive strength, typically 1 to 50 parts by weight relative to 100 parts by weight of the base polymer, more preferably 10 to 30 parts by weight.

[0108] [Example]

[0109] The present invention will be specifically described below through embodiments, but the present invention is not limited to these embodiments. The evaluation methods in the embodiments are described below. In addition, unless otherwise specified, "parts" and "%" are based on weight in the embodiments.

[0110] (1) Peel strength of the cover film (the peeling force of the cover film on the gas adsorption layer)

[0111] After drying at 130°C for 3 hours under reduced pressure of -100 kPa, the covering film was peeled off from the gas adsorption layer from the gas adsorption sheet with the covering film attached, and its peel strength was measured.

[0112] Test speed: 300 mm / min

[0113] Peeling angle: 180 degrees

[0114] Measurement temperature: 25℃

[0115] (2) Cover film peelability

[0116] The failure modes during the capping film peeling test were evaluated.

[0117] ○: Capable of peeling at the interface of the covering membrane / gas adsorption layer.

[0118] Δ: The surface layer of the gas adsorption layer is transferred to the side of the covering membrane.

[0119] ×: The entire gas adsorption layer is transferred to the side of the covering membrane.

[0120] (3) Gas adsorption layer strength

[0121] After drying at 130°C for 3 hours under reduced pressure of -100 kPa, the covering film is peeled off from the gas adsorption layer from the gas adsorption sheet (1) with the covering film attached. The No. 31B manufactured by Nitto Denko Corporation is then attached to the surface of the exposed gas adsorption layer after peeling, and its peel strength is evaluated.

[0122] Bonding conditions: Bonding is performed at 25°C by rolling a 2kg roller back and forth once.

[0123] Test speed: 300 mm / min

[0124] Peeling angle: 180 degrees

[0125] Measurement temperature: 25℃

[0126] (4) Heat resistance

[0127] The state of the gas adsorption sheet after drying at 130°C for 3 hours under reduced pressure of -100 kPa was confirmed.

[0128] ○: Able to maintain the shape of the slice

[0129] ×: Unable to maintain the shape of the piece

[0130] (5) Gas adsorption layer tightness

[0131] When measuring the strength of the gas adsorption layer in (3) above, its damage mode is evaluated.

[0132] ○: Cohesive failure mode of gas adsorption layer

[0133] ×: Anchoring failure mode of gas adsorption layer

[0134] (6) Processability

[0135] After punching the gas adsorption sheet with a covering film using a Thomson die (5mm×20mm size, die thickness 0.7mm, R:0.2), the condition of the gas adsorption sheet is evaluated.

[0136] ○: The gas adsorption layer has no gaps.

[0137] Δ: Although the gas adsorption layer has no gaps, the covering film bulges and peels off.

[0138] ×: There is a gap in the gas adsorption layer.

[0139] (7)Moisture resistance

[0140] Gas adsorption sheets with a covering film, which were dried at 110°C for 3 hours under reduced pressure of -100 kPa in a drying chamber with a dew point temperature of -50°C and a room temperature of 23°C, were stored in the drying chamber, and the change in moisture content caused by moisture absorption was measured.

[0141] ○: The moisture content was maintained below 1% for more than 8 hours in the drying chamber.

[0142] ×: The drying chamber cannot maintain a moisture content below 1% for 8 hours.

[0143] Moisture content determination method (Karl Fischer method)

[0144] Moisture content: AQ-2100 manufactured by HIRANUMA

[0145] (8) Cover film adhesion

[0146] The obtained cover film (1) was attached to a SUS304BA plate, and the peel strength during peeling was evaluated.

[0147] Bonding conditions: Bonding is performed at 25°C by rolling a 2kg roller back and forth once.

[0148] Test speed: 300 mm / min

[0149] Peeling angle: 180 degrees

[0150] Peeling angle: 180 degrees

[0151] Measurement temperature: 25℃

[0152] (9) Operability

[0153] The defects in the winding of gas adsorption sheets with a covering film onto a 3-inch core containing ABS resin were evaluated.

[0154] ○: No problem.

[0155] ×: The absorption layer is prone to peeling, thermal shrinkage, or damage during transport.

[0156] (10) Evaluation of hydrogen sulfide gas adsorption

[0157] The hydrogen sulfide gas adsorption capacity of a gas adsorption sheet with a covering membrane was evaluated using the following equipment and evaluation methods.

[0158] Experimental equipment

[0159] 1: Tedra sampling bag (10L for sealing test gas) ※Hereinafter referred to as bag

[0160] 2: Test tubes (manufactured by GASTEC, in 4HM, 4M, and 4L formats)

[0161] 3: Thermostatic bath (manufactured by FUKUSHIMA GALILEI, model FMU-263I)

[0162] 4: Air sealing metering pump (manufactured by SIBATA SCIENTIFIC TECHNOLOGY, model MP-Σ300NII)

[0163] 5: Electronic balance (Shimadzu Corporation, model ATX224)

[0164] 6: Hydrogen sulfide gas cylinder (manufactured by Sumitomo Chemical, 99.9% purity)

[0165] 7: Air cylinder (TAIYO NIPPON SANSO manufacturing grade G2)

[0166] Evaluation method: static method

[0167] 1. Dry the sample at 130°C under atmospheric pressure for 3 hours.

[0168] 2: Using an electronic balance, place the weighed sample into a bag and seal it, then expel any residual air from the bag.

[0169] 3: Use a metering pump to introduce a specified amount of air into the bag.

[0170] 4. Use an airtight syringe to inject hydrogen sulfide gas into the bag and adjust the test gas to the specified concentration (340 ppm).

[0171] 5. Place the bag in a constant temperature bath adjusted to the specified temperature / humidity (25℃, 0%RH).

[0172] 6: After the specified time (24 hours), remove the bag and use a test tube to determine the residual concentration inside the bag.

[0173] [Manufacturing Example 1]

[0174] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet pipe, and a condenser, 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), benzoyl peroxide as an initiator (0.2 parts by weight), and toluene (244 parts by weight) were added. Nitrogen gas was introduced while stirring slowly to maintain the liquid temperature in the flask at about 60°C and to carry out the polymerization reaction for about 6 hours to obtain a resin composition (1) containing an acrylic copolymer (1).

[0175] [Manufacturing Example 2]

[0176] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet pipe, and a condenser, 2-ethylhexyl acrylate / hydroxyethyl acrylate (100 parts by weight / 4 parts by weight), 0.2 parts by weight of initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate were added. Nitrogen gas was introduced while stirring slowly to maintain the liquid temperature in the flask at about 60°C and to carry out the polymerization reaction for about 6 hours to obtain a resin composition (2) containing an acrylic copolymer (2).

[0177] [Manufacturing Example 3]

[0178] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet pipe, and a condenser, butyl acrylate / 4-hydroxybutyl acrylate (99 parts by weight / 1 part by weight), 0.2 parts by weight of initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate were added. Nitrogen gas was introduced while stirring slowly to maintain the liquid temperature in the flask at about 60°C and to carry out the polymerization reaction for about 6 hours to obtain a resin composition (3) containing an acrylic copolymer (3).

[0179] [Manufacturing Example 4]

[0180] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet pipe, and a condenser, butyl acrylate / 4-hydroxybutyl acrylate / acrylic acid (97 parts by weight / 3 parts by weight / 0.2 parts by weight), 0.2 parts by weight of initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate were added. Nitrogen gas was introduced while stirring slowly to maintain the liquid temperature in the flask at about 60°C and to carry out the polymerization reaction for about 6 hours to obtain a resin composition (4) containing an acrylic copolymer (4).

[0181] [Manufacturing Example 5]

[0182] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet pipe, and a condenser, 2-ethylhexyl acrylate / acrylic acid (95 parts by weight / 5 parts by weight), 0.2 parts by weight of initiator (benzoyl peroxide), and 120 parts by weight of ethyl acetate were added. Nitrogen gas was introduced while stirring slowly to maintain the liquid temperature in the flask at about 60°C and to carry out the polymerization reaction for about 6 hours to obtain a resin composition (5) containing an acrylic copolymer (5).

[0183] [Manufacturing Example 6] Manufacturing of a heat-resistant substrate with an intermediate layer

[0184] To a resin composition (5) containing 100 parts by weight of an acrylic copolymer (5), 3 parts by weight of an isocyanate crosslinking agent (manufactured by Mitsui Chemicals Co., Ltd., trade name "Takenate D-101E") and ethyl acetate are added to prepare an intermediate layer forming composition (1) with a base content of 18%.

[0185] The obtained intermediate layer forming composition (1) was coated onto a heat-resistant substrate (polyimide film, manufactured by Toray DuPont, trade name "Kapton 100H", thickness: 25 μm) to a thickness of 10 μm after drying, to obtain a heat-resistant substrate (1) with an intermediate layer.

[0186] [Manufacturing Example 7] Surface Treatment Method for Gas Adsorption Particles

[0187] In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen inlet tube, and a condenser, 100 parts by weight of Kesmon NS-20C (manufactured by Toa Synthetic Co., Ltd.) as gas adsorption 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 added. Nitrogen gas was introduced while stirring slowly to maintain the liquid temperature in the flask at about 60°C and carry out the coupling reaction for about 6 hours to obtain surface-treated particles (1).

[0188] [Manufacturing Example 8] Manufacturing of Covering Film (1)

[0189] 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, trade name "Takenate D-101E") and ethyl acetate were added to prepare an adhesive layer forming composition (1) with a matrix content of 15%. The adhesive layer forming composition (1) was coated onto a polyester film (manufactured by Toray Industries, trade name "Lumirror S10") with a thickness of 75 μm after drying to obtain a cover film (1).

[0190] [Manufacturing Example 9] Manufacturing of Covering Film (2)

[0191] Except that the coating thickness of the adhesive layer forming composition (1) is set to 20 μm, the same operation as in manufacturing example 8 is performed to obtain the cover film (2).

[0192] [Manufacturing Example 10] Manufacturing of Covering Film (3)

[0193] 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, trade name "Takenate D-101E") and ethyl acetate were added to prepare an adhesive layer forming composition (2) with a matrix of 15%. The adhesive layer forming composition (2) was coated onto a polyester film (manufactured by Toray Industries, trade name "Lumirror S10") with a thickness of 75 μm after drying to obtain a cover film (3).

[0194] [Manufacturing Example 11] Manufacturing of Covering Film (4)

[0195] Except for setting the thickness of the polyester film to 50 μm, the same operation as in Manufacturing Example 8 was performed to obtain the covering film (4).

[0196] [Manufacturing Example 12] Manufacturing of Covering Film (5)

[0197] Except for setting the thickness of the polyester film to 25 μm, the same operation as in Manufacturing Example 8 was performed to obtain the covering film (5).

[0198] [Manufacturing Example 13] Manufacturing of Covering Film (6)

[0199] To a resin composition (1) containing 100 parts by weight of an acrylic copolymer (1), 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, trade name "Takenate D-101E") and ethyl acetate were added to prepare an adhesive layer forming composition (3) with a matrix of 15%. The adhesive layer forming composition (3) was coated onto a 50 μm thick polyester film (manufactured by Toray Industries, trade name "Lumirror S10") to achieve a thickness of 5 μm after drying, thereby obtaining a cover film (6).

[0200] [Example 1]

[0201] A composition (1) for forming a gas adsorption layer with a matrix of 50% was prepared by adding 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals Co., Ltd., trade name "Takenate D-101E"), ethyl acetate, and 900 parts by weight of hydrogen sulfide gas adsorption particles (copper-loaded silicate Toa Synthetic Co., Ltd., trade name "Kesmon NS-20C", average primary particle size D50: less than 10 μm) to a resin composition (1) containing 100 parts by weight of an acrylic copolymer (1).

[0202] The obtained gas adsorption layer forming composition (1) was coated onto a release film (manufactured by Fujiko Corporation, trade name "CA0", thickness: 75 μm) with a dried thickness of 60 μm to obtain the gas adsorption layer (1).

[0203] The obtained gas adsorption layer (1) is transferred to the intermediate layer of the heat-resistant substrate (1) with an intermediate layer to obtain a gas adsorption sheet (1).

[0204] A covering film (1) was attached to the gas adsorption layer of the gas adsorption sheet (1) to obtain a gas adsorption sheet (1) with a covering film. The obtained gas adsorption sheet (1) with a covering film was evaluated as described above. The results are shown in Table 1.

[0205] [Examples 2-6]

[0206] Except for the resin composition constituting the gas adsorption layer, the mixing amount of hydrogen sulfide gas adsorption particles, the thickness of the gas adsorption layer, and the type of covering film, as shown in Table 1, the operation was performed in the same manner as in Example 1 to obtain a gas adsorption sheet with a covering film. The obtained gas adsorption sheet (1) with a covering film was subjected to the above evaluation. The results are shown in Table 1.

[0207] [Comparative Example 1]

[0208] A composition for forming a gas adsorption layer with a matrix content of 50% is prepared by adding 3 parts by weight of isocyanate crosslinking agent (manufactured by Mitsui Chemicals Co., Ltd., trade name "Takenate D-101E"), ethyl acetate, and 900 parts by weight of hydrogen sulfide gas adsorption particles (copper-loaded silicate, manufactured by Toa Synthetic, trade name "Kesmon NS-20C", average primary particle size D50: less than 10 μm) to a resin composition (3) containing 100 parts by weight of an acrylic copolymer (3).

[0209] The gas adsorption layer forming composition was coated onto a heat-resistant substrate (polyimide film, manufactured by Toray DuPont, trade name "Kapton 100H", thickness: 25 μm) to a dried thickness of 10 μm, to obtain a gas adsorption sheet. The obtained gas adsorption sheet was used for the above evaluation. The results are shown in Table 2.

[0210] [Comparative Example 2]

[0211] A composition for forming a gas adsorption layer with a matrix of 50% was prepared by adding 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, trade name "Takenate D-101E"), ethyl acetate, and 10 parts by weight of hydrogen sulfide gas adsorption particles (copper-loaded silicate, manufactured by Toa Synthetic, trade name "Kesmon NS-20C", average primary particle size D50: less than 10 μm) to a resin composition (3) containing 100 parts by weight of an acrylic copolymer (3).

[0212] The obtained gas adsorption layer forming composition was coated onto a release film (manufactured by Fujiko Corporation, trade name "CA0", thickness: 75 μm) with a dried thickness of 80 μm to obtain a gas adsorption layer.

[0213] The obtained gas adsorption layer is transferred to the intermediate layer of a heat-resistant substrate (1) with an intermediate layer to obtain a gas adsorption sheet.

[0214] [Comparative Example 3]

[0215] A composition for forming a gas adsorption layer with a matrix content of 50% is prepared by adding 3 parts by weight of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, trade name "Takenate D-101E"), ethyl acetate, and 250 parts by weight of hydrogen sulfide gas adsorption particles (copper-loaded silicate, manufactured by Toa Synthetic, trade name "Kesmon NS-20C", average primary particle size D50: less than 10 μm) to a resin composition (3) containing 100 parts by weight of an acrylic copolymer (3).

[0216] The obtained gas adsorption layer forming composition was coated onto a release film (manufactured by Fujiko Corporation, trade name "CA0", thickness: 75 μm) with a dried thickness of 80 μm to obtain a gas adsorption layer.

[0217] The obtained gas adsorption layer is transferred to the intermediate layer of a heat-resistant substrate (1) with an intermediate layer to obtain a gas adsorption sheet.

[0218] [Comparative Example 4]

[0219] Except for replacing 10 parts by weight of hydrogen sulfide gas adsorption particles (copper-loaded silicate, manufactured by Toa Synthetic, trade name "Kesmon NS-20C", average primary particle size D50: 10 μm or less) with 900 parts by weight of molecular sieve 5A (manufactured by Union Showa Corporation), gas adsorption sheets were obtained by operating in the same manner as in Comparative Example 2.

[0220] [Table 1]

[0221]

[0222]

[0223] [Table 2]

[0224]

[0225] Industrial availability

[0226] The gas adsorption sheet of the present invention can be suitably used as a gas adsorption material for non-aqueous secondary batteries.

[0227] Explanation of reference numerals in the attached figures

[0228] 10 Heat-resistant substrate

[0229] 20 Gas Adsorption Layer

[0230] 30 Intermediate Layer

[0231] 110 Gas Adsorption Sheet

[0232] 120 Covering Film

[0233] 100 Gas adsorption sheets with a covering film

Claims

1. A gas adsorption sheet for secondary batteries with a covering film, comprising: A gas adsorption sheet for secondary batteries, comprising a heat-resistant substrate and a gas adsorption layer disposed on at least one side of the heat-resistant substrate; and A covering film is disposed on the side of the gas adsorption layer opposite to the heat-resistant substrate. The gas adsorption layer comprises: a binder resin and gas adsorption particles, wherein the gas adsorption particles are composed of an inorganic porous material with fine pores and are capable of adsorbing gases.

2. The gas absorbing sheet for a secondary battery with a cover film according to claim 1, wherein An intermediate layer is also provided between the heat-resistant substrate and the gas adsorption layer.

3. The gas adsorption sheet for secondary batteries with a covering film as described in claim 1, wherein, The gas adsorption particles are a complex of a metal salt and a silicate selected from at least one of copper, zinc, manganese, cobalt, and nickel. The pore volume of the gas adsorption particles is preferably 0.3 ml / g to 0.5 ml / g.

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

5. The gas absorbing sheet for a secondary battery with a cover film according to claim 4, wherein The organosilicon has an ethoxysilyl or a methoxysilyl group.

6. The gas absorbing sheet for a secondary battery with a cover film according to claim 4, wherein The organosilicon is a silane coupling agent containing epoxy or amino groups.

7. The gas absorbing sheet for a secondary battery with a cover film according to claim 4, wherein The organosilicon is an alkoxysilane or an organosilanes.

8. The gassing-absorbing sheet for a secondary battery with a cover film according to claim 1, wherein The adhesive resin is an acrylic resin.

9. The gas absorbing sheet for a secondary battery with a cover film according to claim 8, wherein The adhesive resin contains structural units derived from alkyl (meth)acrylates. The alkyl methacrylate has a straight-chain or branched alkyl group having 4 to 12 carbon atoms.

10. The gassing-absorbing sheet for a secondary battery with a cover film according to claim 1, wherein The adhesive resin is butyl rubber, isoprene rubber, polyisobutylene rubber, ethylene propylene rubber, or silicone resin.

11. The gas adsorption sheet for secondary batteries with a covering film as described in claim 1, wherein, The content ratio of the gas adsorption particles is 10 to 90 parts by weight relative to 100 parts by weight of the gas adsorption sheet for secondary batteries.

12. The gassing-absorbing sheet for a secondary battery with a cover film according to claim 1, wherein The material constituting the heat-resistant substrate is polyamide-imide, polyether-imide, polyphenylene sulfide, polyethylene naphthalate, polyimide, or polyether ether ketone.

13. The gassing-absorbing sheet for a secondary battery with a cover film according to claim 1, wherein The cover film has a substrate and an adhesive layer disposed on at least one side of the substrate.

14. The gas adsorption sheet for secondary batteries with a covering film as described in claim 13, wherein, The adhesive layer is formed of an adhesive comprising a base polymer. The proportion of structural units derived from organic acid monomers is preferably 0.5 parts by weight or less per 100 parts by weight of the base polymer.

15. The gas absorbing sheet for a secondary battery with a cover film according to claim 13, wherein The covering film can be peeled off.

16. An all-solid-state secondary battery, wherein the gas adsorption sheet of claim 1 is used inside the battery casing.

17. An all-solid-state secondary battery using a sulfide-based solid electrolyte, wherein the all-solid-state secondary battery uses the gas adsorption sheet of claim 1 inside the battery casing.

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