Adhesive compositions, laminates, packaging materials, and packaging materials for battery cases

Abstract

This adhesive composition comprises a crystalline modified olefin polymer, an acid anhydride monomer, and a crosslinking agent. The crystalline modified olefin polymer is obtained by modifying a crystalline C2-20 α-olefin polymer with a monomer having a functional group that is capable of reacting with an epoxy group or an oxazoline group. The acid anhydride monomer has a ring structure and two or more acid anhydride groups. The crosslinking agent includes an epoxy compound and / or an oxazoline compound.

Description

[Technical Field]

[0001] The present invention relates to an adhesive composition, a laminate, a packaging material, and a packaging material for a battery case, more specifically to an adhesive composition, a laminate comprising an adhesive layer made of the adhesive composition, a packaging material comprising the laminate, and a packaging material for a battery case comprising the packaging material. [Background technology]

[0002] In recent years, lithium batteries have been used in personal computers, portable terminals, and other devices due to their slim design. These lithium batteries are typically sealed in packaging materials.

[0003] Such packaging materials can be obtained, for example, by bonding an aluminum foil layer and a polypropylene film with an adhesive.

[0004] As such an adhesive, for example, an adhesive composition comprising a maleic anhydride-modified propylene-butene copolymer, an epoxy resin, and 1,2,3,6-tetrahydrophthalic anhydride has been proposed (see, for example, Example 10 of Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication 2018 / 030050 Brochure [Overview of the project] [Problems that the invention aims to solve]

[0006] On the other hand, such adhesives require good adhesion during low-temperature lamination to improve productivity.

[0007] Furthermore, such adhesives are also required to have heat resistance.

[0008] The present invention provides an adhesive composition that exhibits excellent adhesion and heat resistance during low-temperature lamination, a laminate comprising an adhesive layer made of the adhesive composition, a packaging material comprising the laminate, and a packaging material for a battery case comprising the packaging material. [Means for solving the problem]

[0009] The present invention [1] is an adhesive composition comprising a crystalline modified olefin polymer, an acid anhydride monomer, and a crosslinking agent, wherein the crystalline modified olefin polymer is a crystalline C2-C20 α-olefin polymer modified with a monomer having a functional group reactive with an epoxy group or an oxazoline group, the acid anhydride monomer has a ring structure and two or more acid anhydride groups, and the crosslinking agent comprises an epoxy compound and / or an oxazoline compound.

[0010] The present invention [2] further includes the adhesive composition described in [1] above, which comprises an amorphous hydrocarbon polymer having a kinematic viscosity at 200°C of 1 cSt or more and 100,000 cSt or less.

[0011] The present invention [3] comprises the adhesive composition described in [2] above, wherein the amorphous hydrocarbon polymer is a polymer of an olefin having 2 to 20 carbon atoms.

[0012] The present invention [4] further comprises an adhesive composition according to any one of the above [1] to [3], which includes a catalyst.

[0013] The present invention [5] comprises the adhesive composition described in [4] above, wherein the catalyst is an amine catalyst.

[0014] The present invention [6] comprises an adhesive composition according to any one of the above [1] to [5], wherein the functional group is an acid anhydride group.

[0015] The present invention [7] includes a laminate comprising a first adhesive layer made of the adhesive composition described in any one of the above [1] to [6], and a substrate, arranged sequentially toward one side in the thickness direction.

[0016] The present invention [8] includes a packaging material including an inner layer and the laminate described in [7] above, provided in this order toward one side in the thickness direction.

[0017] The present invention [9] includes a packaging material for a battery case including the packaging material described in [8] above, a second adhesive layer, and an outer layer, provided in this order toward one side in the thickness direction.

Advantages of the Invention

[0018] The adhesive composition of the present invention includes a crystalline modified olefin polymer, an acid anhydride monomer, and a crosslinking agent. In such an adhesive composition, the crystalline modified olefin polymer, the acid anhydride monomer, and the crosslinking agent undergo a crosslinking reaction and harden.

[0019] And the acid anhydride monomer has two or more acid anhydride groups. Therefore, in the above crosslinking reaction, the crosslinking density is improved. As a result, the adhesion during low-temperature lamination is improved.

[0020] Also, the acid anhydride monomer has a ring structure. As a result, the heat resistance is improved.

[0021] The laminate of the present invention includes a first adhesive layer made of the adhesive composition of the present invention. Therefore, it is excellent in adhesion and heat resistance during low-temperature lamination.

[0022] The packaging material of the present invention includes the laminate of the present invention. Therefore, it is excellent in adhesion and heat resistance during low-temperature lamination.

[0023] The packaging material for a battery case of the present invention includes the packaging material of the present invention. Therefore, it is excellent in adhesion and heat resistance during low-temperature lamination.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 is a schematic view showing an embodiment of the laminate of the present invention. [Figure 2]Figures 2A and 2B show one embodiment of the method for manufacturing a laminate according to the present invention. Figure 2A shows the first step of preparing the substrate. Figure 2B shows the second step of arranging (forming) the first adhesive layer on the other side of the substrate in the thickness direction. [Figure 3] Figure 3 is a schematic diagram showing one embodiment of the packaging material of the present invention. [Figure 4] Figure 4 is a schematic diagram showing one embodiment of the battery case packaging material of the present invention and a battery using this battery case packaging material. [Modes for carrying out the invention]

[0025] 1. Adhesive composition The adhesive composition comprises a crystalline modified olefin polymer, an acid anhydride monomer, and a crosslinking agent.

[0026] <Crystalline modified olefin polymer> Crystalline modified olefin polymers are obtained by modifying a crystalline α-olefin polymer having 2 to 20 carbon atoms with a monomer having a functional group that can react with an epoxy group or an oxazoline group.

[0027] [Crystalline α-olefin polymers with 2 to 20 carbon atoms] Crystalline α-olefin polymers having 2 to 20 carbon atoms are olefin polymers that contain constituent units derived from α-olefins having 2 to 20 carbon atoms capable of forming crystalline polymers. In other words, crystalline α-olefin polymers having 2 to 20 carbon atoms are obtained by polymerizing α-olefins having 2 to 20 carbon atoms. Crystallinity is defined as a property of a compound having a heat of fusion (described later) of 1 J / g or more.

[0028] Examples of α-olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

[0029] Preferably, the constituent units derived from α-olefins having 2 to 20 carbon atoms include those derived from α-olefins having 2 to 4 carbon atoms. More preferably, the constituent units derived from α-olefins having 2 to 20 carbon atoms include those derived from propylene and those derived from 1-butene. In other words, the crystalline α-olefin polymer having 2 to 20 carbon atoms is preferably a propylene / 1-butene copolymer.

[0030] Furthermore, the types of constituent units derived from α-olefins having 2 to 20 carbon atoms, and their respective content ratios, are selected so that the olefin polymer becomes crystalline.

[0031] Specifically, when the constituent units derived from α-olefins having 2 to 20 carbon atoms include constituent units derived from propylene and constituent units derived from 1-butene, the content ratio of propylene-derived constituent units relative to the total amount of propylene-derived constituent units and 1-butene-derived constituent units (100 mol%) is, for example, 50 mol% or more, preferably 60 mol% or more, and also, for example, 95 mol% or less, preferably 85 mol% or less. Furthermore, the content ratio of 1-butene-derived constituent units relative to the total amount of propylene-derived constituent units and 1-butene-derived constituent units (100 mol%) is, for example, 5 mol% or more, preferably 15 mol% or more, and also, for example, 50 mol% or less, preferably 40 mol% or less.

[0032] If the content of propylene-derived structural units and the content of 1-butene-derived structural units are above the lower limit and below the upper limit, the adhesion during low-temperature lamination will be excellent.

[0033] The above-mentioned content percentages are, for example, 13 This can be confirmed by known methods such as 13C-NMR measurement (the same applies hereafter).

[0034] Crystalline α-olefin polymers having 2 to 20 carbon atoms can be obtained, for example, by the methods described in Japanese Patent No. 3939464 and International Publication No. 2004 / 87775. More specifically, crystalline α-olefin polymers having 2 to 20 carbon atoms can be obtained by polymerizing α-olefins having 2 to 20 carbon atoms in the presence of a metallocene catalyst.

[0035] The heat of fusion of a crystalline α-olefin polymer having 2 to 20 carbon atoms, as measured according to JIS K7122, is, for example, 1 J / g or more, preferably 10 J / g or more, more preferably 20 J / g or more, and also, for example, 50 J / g or less, preferably 40 J / g or less.

[0036] If the heat of fusion is above the lower limit and below the upper limit, excellent adhesion is achieved during low-temperature lamination.

[0037] Furthermore, the melting point of the crystalline α-olefin polymer having 2 to 20 carbon atoms is, for example, 40°C or higher, preferably 60°C or higher, and also, for example, 100°C or lower, preferably 90°C or lower.

[0038] The melting point can be measured using a differential scanning calorimeter (the same applies hereafter).

[0039] Furthermore, the weight-average molecular weight of a crystalline α-olefin polymer having 2 to 20 carbon atoms, measured by GPC (gel permeation chromatography) and converted to standard polystyrene, is, for example, 10,000 or more, preferably 50,000 or more, and also, for example, 500,000 or less, preferably 400,000 or less.

[0040] Crystalline α-olefin polymers with 2 to 20 carbon atoms can be used alone or in combination of two or more types.

[0041] [monomer] The monomer has a functional group that can react with an epoxy group or an oxazoline group.

[0042] Examples of such functional groups include hydroxyl groups, amino groups, carboxyl groups, acid anhydride groups, ester groups, and thiol groups.

[0043] The monomer is a compound having the above-mentioned functional group, and examples include hydroxyl group-containing ethylenically unsaturated compounds, amino group-containing ethylenically unsaturated compounds, unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, vinyl ester compounds, and thiol group-containing ethylenically unsaturated compounds.

[0044] Hydroxyl group-containing ethylenically unsaturated compounds have a hydroxyl group as the functional group. Examples of hydroxyl group-containing ethylenically unsaturated compounds include hydroxyl group-containing (meth)acrylic acid esters. Examples of hydroxyl group-containing (meth)acrylic acid esters include 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate.

[0045] The amino group-containing ethylenically unsaturated compound has an amino group as the functional group. Examples of amino group-containing ethylenically unsaturated compounds include (meth)aminomethyl acrylate and (meth)propylaminoethyl acrylate.

[0046] Unsaturated carboxylic acids have a carboxyl group as the functional group described above. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornenedicarboxylic acid, and bicyclo[2,2,1]hepto-2-ene-5,6-dicarboxylic acid.

[0047] Unsaturated carboxylic acid anhydrides have an acid anhydride group as the functional group described above. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo[2,2,1]hepto-2-ene-5,6-dicarboxylic acid anhydride. Maleic anhydride is preferably given as the unsaturated carboxylic acid anhydride.

[0048] Vinyl ester compounds have an ester group as the functional group described above. Examples of vinyl ester compounds include vinyl acetate, vinyl propionate, and vinyl n-butyrate.

[0049] Thiol group-containing ethylenically unsaturated compounds have a thiol group as the functional group. Examples of thiol group-containing ethylenically unsaturated compounds include allyl mercaptan and 2-vinylbenzyl mercaptan.

[0050] Preferably, the monomer is an unsaturated carboxylic acid and / or an unsaturated carboxylic acid anhydride. In other words, preferably, the functional group is a carboxyl group and / or an acid anhydride group. If the functional group is a carboxyl group and / or an acid anhydride group, the pot life and adhesion during low-temperature lamination can be improved.

[0051] Furthermore, unsaturated carboxylic acid anhydrides are more preferably used as monomers. In other words, acid anhydride groups are more preferably used as the functional groups. If the functional group is an acid anhydride group, the pot life and adhesion during low-temperature lamination can be further improved.

[0052] Monomers can be used individually or in combination of two or more types.

[0053] [Production of crystalline modified olefin polymers] Crystalline modified olefin polymers are obtained by modifying crystalline α-olefin polymers having 2 to 20 carbon atoms with monomers.

[0054] To modify a crystalline α-olefin polymer having 2 to 20 carbon atoms using monomers, for example, first, the crystalline α-olefin polymer having 2 to 20 carbon atoms is dissolved in a known organic solvent (e.g., toluene).

[0055] Next, the monomer and radical polymerization initiator are added, and the mixture is heated and stirred.

[0056] The amount of monomer modification (introduction amount) in a modified crystalline C2-C20 α-olefin polymer, that is, the content ratio of constituent units derived from monomers in a modified crystalline C2-C20 α-olefin polymer, is, for example, 0.1% by mass or more, preferably 0.5% by mass or more, and for example, 15% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 4% by mass or less, particularly preferably 2% by mass or less, and most preferably 1.5% by mass or less, relative to the modified crystalline C2-C20 α-olefin polymer.

[0057] If the above-mentioned degradation amount is above the lower limit and below the upper limit, the pot life can be improved.

[0058] The above-mentioned amount of modification is, for example, 1 This can be confirmed by known methods such as 1H-NMR measurement.

[0059] Examples of radical polymerization initiators include organic peroxides and organic peresters.

[0060] Examples of organic peroxides include dicumyl peroxide, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoate)hexine-3, 1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexine-3, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, and tert-butyl peroxybenzoate. Examples of organic peresters include tert-butyl peracetate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl persec-octoate, tert-butyl perpivalate, cumyl perpivalate, and tert-butyl perdiethyl acetate.

[0061] Preferably, organic peroxides are used as radical polymerization initiators. More preferably, di-tert-butyl peroxide is used as a radical polymerization initiator.

[0062] The proportion of the radical polymerization initiator is, for example, 0.001 parts by mass or more, and for example, 10 parts by mass or less, per 100 parts by mass of crystalline α-olefin polymer having 2 to 20 carbon atoms.

[0063] Radical polymerization initiators can be used alone or in combination of two or more types.

[0064] The heating temperature is, for example, 50°C or higher, preferably 80°C or higher, and also, for example, 250°C or lower. The reaction time is, for example, 1 minute or more, and also 10 hours or less.

[0065] This process modifies crystalline α-olefin polymers with 2 to 20 carbon atoms using monomers, yielding crystalline modified olefin polymers (varnishes for crystalline modified olefin polymers).

[0066] Furthermore, the melting point of the crystalline modified olefin polymer is, for example, 40°C or higher, preferably 60°C or higher, and also, for example, 100°C or lower, preferably 90°C or lower.

[0067] Furthermore, the weight-average molecular weight of the crystalline modified olefin polymer, measured by the GPC method and converted to standard polystyrene, is, for example, 10,000 or more, preferably 50,000 or more, and also, for example, 500,000 or less, preferably 300,000 or less, and more preferably 200,000 or less.

[0068] The content ratio of crystalline modified olefin polymers will be described later.

[0069] <Acid anhydride monomer> Acid anhydride monomers have a ring structure and two or more acid anhydride groups. An acid anhydride group refers to a -CO-O-CO- group obtained by the intramolecular dehydration condensation of two carboxylic acid molecules.

[0070] Examples of ring structures include alicyclic structures, heterocyclic structures, and aromatic ring structures. Aromatic ring structures are preferred as the ring structure. In other words, the acid anhydride monomer is preferably an aromatic ring-containing acid anhydride monomer.

[0071] Examples of aromatic ring-containing acid anhydride monomers include aromatic ring-containing dianhydrides and aromatic ring-containing trianhydrides.

[0072] Examples of aromatic ring-containing dianhydrides include pyromellitic anhydride, bisphenol-type dianhydrides (preferably bisphenol A-type dianhydrides), ethylene glycol bisanhydrotrimellitate, naphthalene-1,4,5,8-tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 3,3',4,4'-benzophenonetetracarboxylic dianhydride.

[0073] Examples of aromatic ring-containing acidic trianhydrides include mellitic anhydride.

[0074] Preferably, aromatic ring-containing acid anhydride monomers include aromatic ring-containing acid dianhydrides. More preferably, aromatic ring-containing acid anhydride monomers include pyromellitic anhydride, bisphenol A type acid dianhydride, and / or ethylene glycol bisanhydrotrimellitate. From the viewpoint of improving adhesion and heat resistance during low-temperature lamination, pyromellitic anhydride is even more preferably used as the aromatic ring-containing acid anhydride monomer.

[0075] Acid anhydride monomers can be used alone or in combination of two or more types.

[0076] The molecular weight of the acid anhydride monomer is, for example, 1000 or less, preferably 600 or less, more preferably 400 or less, and also, for example, 100 or more.

[0077] If the molecular weight of the acid anhydride monomer is below the above upper limit, the crosslinking density will improve, thereby enhancing adhesion and heat resistance.

[0078] The content ratio of acid anhydride monomers will be discussed later.

[0079] <Crosslinking agent> The crosslinking agent includes epoxy compounds and / or oxazoline compounds.

[0080] Examples of epoxy compounds include bisphenol-type epoxy resins (e.g., bisphenol A-type epoxy resins, bisphenol F-type epoxy resins), novolac-type epoxy resins (e.g., phenol novolac-type epoxy resins, cresol novolac-type epoxy resins), aliphatic-type epoxy resins, alicyclic epoxy resins, hydrogenated bisphenol-type epoxy resins, and amine-type epoxy resins. , good Examples include novolac-type epoxy resins. More preferably, phenol novolac-type epoxy resins are used as epoxy compounds.

[0081] Examples of oxazoline compounds include oxazoline group-containing polymers. Examples of oxazoline group-containing polymers include homopolymers of oxazoline group-containing monomers, and copolymers of oxazoline group-containing monomers with other monomers copolymerizable with oxazoline group-containing monomers.

[0082] Examples of oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, 2-isopropenyl-2-oxazoline, and 2-isopropenyl-4,4-dimethyl-2-oxazoline.

[0083] Other monomers copolymerizable with oxazoline group-containing monomers include, for example, alkyl (meth)acrylates, unsaturated carboxylic acids (e.g., acrylic acid, methacrylic acid), unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile), unsaturated amides (e.g., (meth)acrylamide), vinyl esters (e.g., vinyl acetate, vinyl propionate), vinyl ethers (e.g., methyl vinyl ether, ethyl vinyl ether), α-olefins (e.g., ethylene, propylene), and unsaturated aromatic monomers (e.g., styrene, α-methylstyrene).

[0084] Preferably, the oxazoline compound is a copolymer of an oxazoline group-containing monomer and another monomer copolymerizable with the oxazoline group-containing monomer. More preferably, the oxazoline compound is oxazoline group-containing polystyrene.

[0085] The crosslinking agent preferably comprises an epoxy compound or an oxazoline compound, and more preferably, from the viewpoint of improving adhesion and heat resistance during low-temperature lamination, it contains an epoxy compound but does not contain an oxazoline compound.

[0086] Crosslinking agents can be used alone or in combination of two or more types.

[0087] The proportion of crosslinking agents will be discussed later.

[0088] <Amorphous hydrocarbon polymers> The adhesive composition may contain an amorphous hydrocarbon polymer as needed to improve its pot life. Amorphous is defined as a compound having a heat of fusion of less than 1 J / g and a Tg of 0°C or less.

[0089] Amorphous hydrocarbon polymers are polymers containing hydrocarbon-derived structural units. From the viewpoint of improving adhesion during low-temperature lamination, olefins having 2 to 20 carbon atoms are preferred as hydrocarbons. In other words, amorphous hydrocarbon polymers are preferably olefin polymers containing hydrocarbon-derived structural units. In other words, amorphous hydrocarbon polymers are preferably polymers of olefins having 2 to 20 carbon atoms.

[0090] Examples of olefins having 2 to 20 carbon atoms include ethylene, propylene, 1-butene, cis-2-butene, trans-2-butene, isobutylene (isobutene), 1-pentene, cis-2-pentene, trans-2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, 1-hexene, 2-hexene, 3-hexene, 2,3-dimethyl-2-butene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Preferably, olefins having 2 to 4 carbon atoms are included as olefins having 2 to 20 carbon atoms. More preferably, ethylene, propylene, and / or isobutylene are included as olefins having 2 to 20 carbon atoms. More preferably, the olefin having 2 to 20 carbon atoms is a combination of ethylene and propylene, or isobutylene used alone. In other words, the amorphous hydrocarbon polymer is more preferably an ethylene / propylene copolymer and / or polyisobutylene.

[0091] Furthermore, the types of hydrocarbon-derived constituent units and their proportions are selected so that the hydrocarbon polymer becomes amorphous.

[0092] Specifically, when the hydrocarbon-derived constituent units include ethylene-derived constituent units and propylene-derived constituent units, the content ratio of ethylene-derived constituent units is, for example, 40 mol% or more, preferably 50 mol% or more, and also, for example, 80 mol% or less, preferably 60 mol% or less, relative to 100 mol% of the total amount of ethylene-derived and propylene-derived constituent units. Furthermore, the content ratio of propylene-derived constituent units is, for example, 20 mol% or more, preferably 40 mol% or more, and also, for example, 60 mol% or less, preferably 50 mol% or less, relative to 100 mol% of the total amount of ethylene-derived and propylene-derived constituent units.

[0093] If the content ratio of ethylene-derived structural units and the content ratio of propylene-derived structural units are above the lower limit and below the upper limit, the adhesion during low-temperature lamination will be excellent.

[0094] Amorphous hydrocarbon polymers can be produced by the same method as the method for producing crystalline α-olefin polymers having 2 to 20 carbon atoms, as exemplified by the crystalline modified olefin polymers described above.

[0095] The kinematic viscosity of amorphous hydrocarbon polymers at 200°C is, for example, 1 cSt or more, and for example, 100,000 cSt or less. Furthermore, amorphous hydrocarbon polymers can be distinguished into amorphous hydrocarbon synthetic oils and amorphous hydrocarbon semi-solid resins based on the above kinematic viscosity. Specifically, amorphous hydrocarbon polymers having the above kinematic viscosity of 1 cSt or more, preferably 10 cSt or more, more preferably 100 cSt or more, and for example, 10,000 cSt or less, preferably 1,000 cSt or less, and more preferably 500 cSt or less are amorphous hydrocarbon synthetic oils. Furthermore, amorphous hydrocarbon polymers having the above kinematic viscosity exceeding 10,000 cSt, preferably 30,000 cSt or more, and for example, 100,000 cSt or less, preferably 60,000 cSt or less are amorphous hydrocarbon semi-solid resins.

[0096] If the kinematic viscosity at 200°C is above the lower limit and below the upper limit, adhesion during low-temperature lamination can be improved.

[0097] The kinematic viscosity at 200°C can be measured according to JIS K 2283.

[0098] Furthermore, the weight-average molecular weight of the amorphous hydrocarbon polymer, measured by the GPC method and converted to standard polystyrene, is, for example, 5,000 or more, and for example, 300,000 or less. More specifically, when the amorphous hydrocarbon polymer is an amorphous hydrocarbon synthetic oil, the above weight-average molecular weight is, for example, 5,000 or more, preferably 10,000 or more, and for example, 300,000 or less, preferably 100,000 or less, more preferably 50,000 or less, even more preferably 20,000 or less. Furthermore, when the amorphous hydrocarbon polymer is an amorphous hydrocarbon semi-solid resin, the above weight-average molecular weight is, for example, 5,000 or more, preferably 10,000 or more, more preferably 50,000 or more, even more preferably 100,000 or more, even more preferably 120,000 or more, and for example, 300,000 or less, preferably 200,000 or less, even more preferably 160,000 or less.

[0099] Amorphous hydrocarbon polymers can be used alone or in combination of two or more types.

[0100] The proportion of amorphous hydrocarbon polymers will be discussed later.

[0101] <Catalyst> Adhesive compositions may also contain catalysts to promote the crosslinking reaction of the crosslinking agent. Examples of catalysts include amine catalysts and phosphine catalysts.

[0102] Examples of amine catalysts include strongly basic tertiary amines. Examples of strongly basic tertiary amines include 1,8-diazabicyclo[5.4.0]undecene-7(DBU) and 1,6-diazabicyclo[3.4.0]-5-nonene. Preferably, 1,8-diazabicyclo[5.4.0]undecene-7(DBU) is used as the amine catalyst.

[0103] Examples of phosphine catalysts include tributylphosphine, methyldiphenylphosphine, triphenylphosphine, and phenylphosphine. Triphenylphosphine is preferred as the phosphine catalyst.

[0104] As a catalyst, amine catalysts are preferred from the viewpoint of improving adhesion and heat resistance during low-temperature lamination.

[0105] Catalysts can be used individually or in combination of two or more types.

[0106] The proportion of catalysts will be discussed later.

[0107] <Additives> The adhesive composition may also contain additives in appropriate proportions as needed.

[0108] Examples of additives include leveling agents, defoaming agents, antioxidants, heat stabilizers, UV absorbers, plasticizers, surfactants, pigments, thixotropes, thickeners, tackifiers, surface modifiers, anti-settling agents, weathering agents, pigment dispersants, antistatic agents, fillers, fungicides, and silane coupling agents.

[0109] Additives can be used individually or in combination of two or more types.

[0110] <Preparation of adhesive composition> To prepare the adhesive composition, a crystalline modified olefin polymer, an acid anhydride monomer, a crosslinking agent, an amorphous hydrocarbon polymer as needed, a catalyst as needed, and additives as needed are mixed together.

[0111] Specifically, a resin composition is first prepared by mixing a crystalline modified olefin polymer with an amorphous hydrocarbon polymer, which may be added as needed. More specifically, a varnish of the resin composition is prepared by mixing a crystalline modified olefin polymer with an amorphous hydrocarbon polymer, which may be added as needed, and dissolving it in a solvent.

[0112] Examples of solvents include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ketones, alkyl esters, glycol ether esters, ethers, and polar aprotons. Examples of aliphatic hydrocarbons include n-hexane, n-heptane, and octane. Examples of alicyclic hydrocarbons include cyclohexane and methylcyclohexane. Examples of aromatic hydrocarbons include toluene and xylene. Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of alkyl esters include methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate. Examples of glycol ether esters include methyl cellosolve acetate, ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, and ethyl-3-ethoxypropionate. Examples of ethers include diethyl ether, tetrahydrofuran, and dioxane. Examples of polar aprotons include N-methylpyrrolidone, dimethylformamide, N,N'-dimethylacetamide, dimethyl sulfoxide, and hexamethylphosphonylamide.

[0113] Preferred solvents include alicyclic hydrocarbons and alkyl esters. More preferably, methylcyclohexane and / or ethyl acetate are used as solvents.

[0114] The solvent can be used alone or in combination of two or more types. Preferably, methylcyclohexane and ethyl acetate are used together as the solvent.

[0115] The solvent is added in an amount of, for example, 200 parts by mass or more, and for example, 1000 parts by mass or less, per 100 parts by mass of the total amount of the crystalline modified olefin polymer and the amorphous hydrocarbon polymer added as needed.

[0116] The dissolution temperature is, for example, 40°C or higher, and for example, 110°C or lower. The dissolution time is, for example, 1 hour or more, and for example, 4 hours or less.

[0117] This is used to prepare the resin composition.

[0118] Furthermore, the acid value of the resin composition is, for example, 1.00 KOH mg / g or more, preferably 5.00 KOH mg / g or more, and for example, 20.00 KOH mg / g or less, preferably 15.00 KOH mg / g or less, and more preferably 10.00 KOH mg / g or less.

[0119] The method for measuring the acid value described above will be explained in detail in the examples below.

[0120] Next, the resin composition is blended with an acid anhydride monomer, a crosslinking agent, a catalyst as needed, and additives as needed.

[0121] This allows for the preparation of an adhesive composition (a varnish for the adhesive composition).

[0122] The content of the crystalline modified olefin polymer is, for example, 70 parts by mass or more, preferably 80 parts by mass or more, more preferably 85 parts by mass or more, and for example, 95 parts by mass or less, based on 100 parts by mass of the total amount of the crystalline modified olefin polymer, acid anhydride monomer, and crosslinking agent.

[0123] Furthermore, the content of the acid anhydride monomer is, for example, 0.1 parts by mass or more, preferably 1.0 part by mass or more, more preferably 1.5 parts by mass or more, and 5.0 parts by mass or less, preferably 3.0 parts by mass or less, and more preferably 2.0 parts by mass or less, based on 100 parts by mass of the total amount of the crystalline modified olefin polymer, the acid anhydride monomer, and the crosslinking agent.

[0124] Furthermore, the content of the acid anhydride monomer is, for example, 0.1 parts by mass or more, preferably 1.0 part by mass or more, more preferably 1.5 parts by mass or more, and also, for example, 5.0 parts by mass or less, preferably 3.0 parts by mass or less, more preferably 2.5 parts by mass or less, per 100 parts by mass of the crystalline modified olefin polymer.

[0125] Furthermore, the content of the acid anhydride monomer is, for example, 1.0 part by mass or more, preferably 5.0 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, or, for example, 40 parts by mass or less, preferably 30 parts by mass or less, and more preferably 25 parts by mass or less, per 100 parts by mass of the crosslinking agent.

[0126] Furthermore, the molar ratio of acid anhydride monomer to monomer (acid anhydride monomer / monomer) in crystalline C2-C20 α-olefin polymers is, for example, 0.5 or more, preferably 1.0 or more, more preferably 2.0 or more, and also, for example, 7.0 or less, preferably 6.0 or less, more preferably 5.0 or less.

[0127] Furthermore, the crosslinking agent content is, for example, 1.0 part by mass or more, preferably 5.0 parts by mass or more, more preferably 8.0 parts by mass or more, and also, for example, 20 parts by mass or less, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the total amount of the crystalline modified olefin polymer, acid anhydride monomer, and crosslinking agent.

[0128] Furthermore, the crosslinking agent content is, for example, 1.0 part by mass or more, preferably 5.0 parts by mass or more, more preferably 8.0 parts by mass or more, and also, for example, 30 parts by mass or less, preferably 20 parts by mass or less, more preferably 15 parts by mass or less, per 100 parts by mass of the crystalline modified olefin polymer.

[0129] Furthermore, if the adhesive composition contains an amorphous hydrocarbon polymer, the content of the crystalline modified olefin polymer is, for example, 60 parts by mass or more, preferably 70 parts by mass or more, and for example, 90 parts by mass or less, based on 100 parts by mass of the total amount of the crystalline modified olefin polymer and the amorphous hydrocarbon polymer. Furthermore, the content of the amorphous hydrocarbon polymer is, for example, 10 parts by mass or more, and for example, 40 parts by mass or less, and for example, 30 parts by mass or less, based on 100 parts by mass of the total amount of the crystalline modified olefin polymer and the amorphous hydrocarbon polymer.

[0130] Furthermore, the content ratio of the catalyst is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and for example, 2.0 parts by mass or less, preferably 1.0 part by mass or less, based on 100 parts by mass of the total amount of the crystalline modified olefin polymer, acid anhydride monomer, and crosslinking agent.

[0131] Furthermore, the adhesive composition may be diluted with the solvent during and / or after the above preparation.

[0132] When the adhesive composition is diluted, the solid content concentration of the varnish in the adhesive composition is, for example, 10% by mass or more, and for example, 70% by mass or less.

[0133] Furthermore, the acid value of the adhesive composition is, for example, 1.00 KOH mg / g or more, preferably 5.00 KOH mg / g or more, more preferably 10.00 KOH mg / g or more, even more preferably 15.00 KOH mg / g or more, and also, for example, 30.00 KOH mg / g or less, preferably 25.00 KOH mg / g or less.

[0134] The method for measuring the acid value described above will be explained in detail in the examples below.

[0135] <Effects and Effects> The adhesive composition comprises a crystalline modified olefin polymer, an acid anhydride monomer, and a crosslinking agent. In such an adhesive composition, the crystalline modified olefin polymer, the acid anhydride monomer, and the crosslinking agent undergo a crosslinking reaction, resulting in curing.

[0136] Furthermore, the acid anhydride monomer has two or more acid anhydride groups. Therefore, the crosslinking density is improved in the above crosslinking reaction. As a result, adhesion during low-temperature lamination is improved.

[0137] Furthermore, acid anhydride monomers have a cyclic structure. As a result, their heat resistance is improved.

[0138] Because the adhesive composition exhibits excellent adhesion and heat resistance during low-temperature lamination, it can be suitably used as an adhesive (dry laminating adhesive) for various components (e.g., electronic components, optical components, and battery components), and is particularly suitable as an adhesive for battery case packaging.

[0139] The following description details a laminate comprising an adhesive layer made of the above-mentioned adhesive composition, a packaging material comprising the laminate, and a battery case packaging material comprising the packaging material.

[0140] 2. Laminate An embodiment of the laminate of the present invention will be described with reference to Figure 1.

[0141] In Figure 1, the vertical direction of the paper is the vertical direction (thickness direction), with the top of the paper being the top (one side in the thickness direction) and the bottom of the paper being the bottom (the other side in the thickness direction). The horizontal and depth directions of the paper are plane directions perpendicular to the vertical direction. Specifically, these correspond to the directional arrows in each figure.

[0142] The laminate 10 has a film shape (including a sheet shape) with a predetermined thickness. The laminate 10 extends in a planar direction perpendicular to the thickness direction. The laminate 10 has a flat top surface and a flat bottom surface.

[0143] The laminate 10 comprises a first adhesive layer 1 and a base material 2, arranged sequentially toward one side in the thickness direction. Specifically, the laminate 10 comprises a first adhesive layer 1 and a base material 2 that is directly placed on the upper surface (one side in the thickness direction) of the first adhesive layer 1.

[0144] The thickness of the laminate 10 is not particularly limited. For example, the thickness of the laminate 10 may be 10 μm or more, or 150 μm or less.

[0145] [First adhesive layer] The first adhesive layer 1 is an adhesive layer for bonding any adherend to the substrate 2. The first adhesive layer 1 consists of an adhesive composition.

[0146] Next, to form the first adhesive layer 1, as will be described in detail later, the adhesive composition is applied to the other surface of the substrate 2 in the thickness direction, heated if necessary, and dried. This forms the first adhesive layer 1.

[0147] The thickness of the first adhesive layer 1 is, for example, 1 μm or more, and for example, 50 μm or less.

[0148] [Base material] The base material 2 has a film shape (including a sheet shape) with a predetermined thickness.

[0149] The material of the base material 2 is not particularly limited. Examples of materials for the base material 2 include polymer materials and metallic materials. Examples of polymer materials include olefin resins (e.g., polyethylene, polypropylene), acrylic resins, polyester resins, polycarbonate resins, acrylonitrile-styrene-butadiene copolymer resins (ABS resins), polyamide resins (e.g., nylon), and polyphenylene sulfide resins. Examples of metallic materials include aluminum, gold, silver, copper, nickel, zinc, titanium, cobalt, indium, and chromium. In particular, when the laminate 10 is provided in a packaging material 20 (described later), a metallic material is preferably selected as the material for the base material 2, and aluminum is more preferably selected.

[0150] The thickness of the substrate 2 is not particularly limited. For example, the thickness of the substrate 2 may be 10 μm or more, or 100 μm or less.

[0151] [Manufacturing of laminates] An embodiment of a method for manufacturing a laminate will be described with reference to Figures 2A and 2B.

[0152] The method for manufacturing the laminate 10 comprises a first step of preparing a base material 2, and a second step of applying an adhesive composition to the other surface of the base material 2 in the thickness direction and arranging (forming) the first adhesive layer 1 on the other surface of the base material 2 in the thickness direction.

[0153] In the first step, the base material 2 is prepared as shown in Figure 2A.

[0154] In the second step, as shown in Figure 2B, the first adhesive layer 1 is placed (formed) on the other side of the substrate 2 in the thickness direction.

[0155] To place (form) the first adhesive layer 1 on the other surface of the substrate 2 in the thickness direction, a varnish of the adhesive composition is applied to the other surface of the substrate 2 in the thickness direction.

[0156] To apply the varnish of the adhesive composition to the other surface of the substrate 2 in the thickness direction, first, if necessary, the other surface of the substrate 2 in the thickness direction is subjected to surface treatment.

[0157] Examples of surface treatments include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment, with corona treatment being preferred.

[0158] Next, the varnish of the adhesive composition is applied to the other surface of the substrate 2 in the thickness direction by a known method, and heated and dried as necessary.

[0159] The heating temperature is, for example, 50°C or higher, preferably 80°C or higher, and also, for example, 140°C or lower. The heating time is, for example, 10 seconds or more, and also, for example, 120 seconds or less.

[0160] This arranges (forms) a first adhesive layer 1 made of the adhesive composition on the other surface of the substrate 2 in the thickness direction. The laminate 10 is then manufactured.

[0161] Such a laminate 10 includes a first adhesive layer 1 made of an adhesive composition. Therefore, when this laminate 10 is bonded to any adherend via the first adhesive layer 1, it exhibits excellent adhesion and heat resistance during low-temperature lamination.

[0162] 3. Packaging material An embodiment of the packaging material of the present invention will be described with reference to Figure 3.

[0163] The packaging material 20 has a film shape (including a sheet shape) with a predetermined thickness. The packaging material 20 extends in a planar direction perpendicular to the thickness direction. The packaging material 20 has a flat top surface and a flat bottom surface.

[0164] The packaging material 20 comprises an inner layer 3 and a laminate 10 (a laminate 10 in which the first adhesive layer 1 and the base material 2 are arranged sequentially toward one side in the thickness direction) toward one side in the thickness direction. Specifically, the packaging material 20 comprises an inner layer 3 and a laminate 10 that is directly placed on the upper surface (one side in the thickness direction) of the inner layer 3.

[0165] The thickness of the packaging material 20 is not particularly limited. For example, the thickness of the packaging material 20 may be 15 μm or more, or 300 μm or less.

[0166] [Inner layer] The inner layer 3 is the inner layer when the packaging material 20 is formed into a bag.

[0167] The material of the inner layer 3 is appropriately selected depending on whether or not the packaging material 20 is heat-sealable and the type of contents contained in the bag. As will be explained in more detail later, if the contents are an electrolyte, a polyolefin film is selected.

[0168] The thickness of the inner layer 3 is not particularly limited. For example, the thickness of the inner layer 3 may be 10 μm or more, or 600 μm or less.

[0169] [Manufacturing of packaging materials] To manufacture the packaging material 20, the inner layer 3 is placed on the other side of the laminate 10 in the thickness direction (the other side of the first adhesive layer 1 in the thickness direction), and the first adhesive layer 1 is aged. As a result, the first adhesive layer 1 hardens, and the inner layer 3 and the laminate 10 bond together. The packaging material 20 is manufactured in this way.

[0170] The aging temperature is low because the packaging material 20 includes the laminate 10. Specifically, it is 20°C or higher, preferably 40°C or higher, and for example, 80°C or lower. The aging time is, for example, 1 day or more, and for example, 7 days or less, preferably 5 days or less.

[0171] The packaging material 20 comprises a laminate 10. Therefore, it has excellent adhesion and heat resistance during low-temperature lamination.

[0172] 4. Packaging materials for battery cases and batteries Referring to Figure 4, an embodiment of the battery case packaging material of the present invention and a battery using this battery case packaging material will be described.

[0173] The battery 30 comprises a battery case packaging material 31 and an electrolyte 32 packaged in the battery case packaging material 31. The battery 30 also comprises a positive electrode 33, a negative electrode 34, and a separator 35 housed within the battery case packaging material 31.

[0174] [Battery case packaging material] The battery case packaging material 31 is configured in a bag-like shape such that the inner layer 3 of the battery case packaging material 31 comes into contact with the electrolyte 32. Specifically, the battery case packaging material 31 packages the electrolyte 32 so that the inner layer 3 comes into contact with the electrolyte 32.

[0175] The battery case packaging material 31, as shown in the enlarged view of A in Figure 4, comprises a packaging material 20 (a packaging material 20 having an inner layer 3, a first adhesive layer 1, and a base material 2 arranged in order toward one side in the thickness direction), a second adhesive layer 4, and an outer layer 5 arranged in order toward one side in the thickness direction. Specifically, the battery case packaging material 31 comprises a packaging material 20, a second adhesive layer 4 directly disposed on the upper surface (one side in the thickness direction) of the packaging material 20, and an outer layer 5 directly disposed on the upper surface (one side in the thickness direction) of the second adhesive layer 4.

[0176] As described above, the packaging material 20 is provided with an inner layer 3, a first adhesive layer 1, and a base material 2 in order toward one side in the thickness direction. In the battery case packaging material 31, the inner layer 3 is selected as a polyolefin film from the viewpoint of chemical resistance (electrolyte resistance) to the electrolyte 32. Examples of polyolefin films include polyethylene-based films and polypropylene-based films. Examples of polyethylene-based films include low-density polyethylene film (LDPE) and linear low-density polyethylene film (LLDPE). Examples of polypropylene-based films include stretched polypropylene film (CPP film), uniaxially oriented polypropylene film, and biaxially oriented polypropylene film (OPP film). Preferably, a polypropylene-based film is used as the polyolefin film. More preferably, a stretched polypropylene film (CPP film) is used as the polyolefin film.

[0177] Furthermore, in the battery case packaging material 31, a metal material is preferably used as the material for the base material 2. More preferably, aluminum is used as the material for the base material 2.

[0178] The second adhesive layer 4 is formed from a known adhesive. Alternatively, the above-mentioned adhesive composition can be used instead of the known adhesive.

[0179] The thickness of the second adhesive layer 4 is not particularly limited. Second adhesive layer 4 The thickness is, for example, 1 μm or more, and for example, 50 μm or less.

[0180] The outer layer 5 is the outer layer of the battery case packaging material 31.

[0181] Examples of materials for the outer layer 5 include the polymer materials exemplified in the base material 2 described above, preferably polyamide resin, and more preferably nylon.

[0182] The thickness of the outer layer 5 is not particularly limited. For example, the thickness of the outer layer 5 may be 10 μm or more, or 100 μm or less.

[0183] The battery case packaging material 31 is manufactured by placing an outer layer 5 on a second adhesive layer 4, which is formed by applying a known adhesive (or adhesive composition) to one side of the packaging material 20 in the thickness direction (one side of the base material 2 in the thickness direction).

[0184] The battery case packaging material 31 includes the packaging material 20. Therefore, it has excellent adhesion and heat resistance during low-temperature lamination.

[0185] Furthermore, in Figure 4, the battery case packaging material 31 is formed into a bag shape by sealing both ends (mutually opposing inner layers 3) with heat seal.

[0186] [Electrolyte] The electrolyte 32 is not particularly limited and may contain, for example, ethylene carbonate, diethyl carbonate, dimethyl carbonate, and lithium salts such as lithium hexafluoride phosphate.

[0187] The positive electrode 33 and the negative electrode 34 are positioned opposite each other with a gap between them so as to be in contact with the electrolyte 32. The separator 35 is positioned so as to be sandwiched between the positive electrode 33 and the negative electrode 34.

[0188] The battery 30 described above is used, for example, as a lithium-ion secondary battery. In such cases, the battery case packaging material 31 is used as packaging material for a lithium-ion secondary battery case. [Examples]

[0189] Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, "parts" and "%" are based on mass. Furthermore, specific numerical values ​​such as blending ratios (content), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than") of the blending ratios (content), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above.

[0190] <Details of ingredients> The product names and abbreviations of the components used in each manufacturing example, each embodiment, and each comparative example are described in detail below. Opanol B12SFN: Amorphous hydrocarbon polymer, polyisobutylene, weight-average molecular weight: 76,000, kinematic viscosity at 200°C measured according to JIS K 2283: 37,000 cSt, manufactured by BASF. PMDA: Pyromellitic anhydride, molecular weight approximately 218, manufactured by Tokyo Chemical Industry Co., Ltd. BISDA: Bisphenol A type acidic dianhydride, molecular weight approximately 520, manufactured by SABIC. TMEG-100: Ethylene glycol bisanhydrotrimellitate, molecular weight approximately 410, manufactured by Shin-Nippon Rika Co., Ltd. TH: 1,2,3,6-tetrahydrophthalic anhydride, manufactured by Shin-Nippon Rika Co., Ltd. jER152: Phenolic novolac type epoxy resin, manufactured by Mitsubishi Chemical Corporation. RPS-1005: Oxazoline group-containing polystyrene, manufactured by Nippon Shokubai Co., Ltd. D-170N: Isocyanate compound, manufactured by Mitsui Chemicals, Inc. DBU:1,8-Diazabicyclo[5.4.0]undecene-7, manufactured by Wakosha. TPP: Triphenylphosphine, manufactured by Wakosha Co., Ltd.

[0191] <Production of crystalline modified olefin polymers> Manufacturing Example 1 [Production of crystalline α-olefin polymers with 2 to 20 carbon atoms] 900 ml of hexane and 90 g of 1-butene were charged into a 2-liter autoclave that had been thoroughly purged with nitrogen. Then, 1 mmol of triisobutylaluminum was added, and after raising the temperature to 70°C, propylene was supplied to a total pressure of 7 kg / cm². 2 Set to G, add 0.30 mmol of methylaluminoxane and 0.001 mmol of rac-dimethylsilylene-bis{1-(2-methyl-4-phenylindenyl)}zirconium dichloride (calculated as Zr atoms), and continuously supply propylene to a total pressure of 7 kg / cm². 2 Maintain the G position for 30 minutes If This was done to produce a propylene / 1-butene copolymer (a crystalline α-olefin polymer with 2 to 20 carbon atoms). After polymerization, the copolymer was degassed and recovered in a large amount of methanol, and then dried under reduced pressure at 110°C for 12 hours.

[0192] The melting point of the propylene / 1-butene copolymer was 78.3°C. The heat of fusion of the propylene / 1-butene copolymer, measured according to JIS K7122, was 29.2 J / g. The weight-average molecular weight of the propylene / 1-butene copolymer, measured by GPC and converted to standard polystyrene, was 330,000. The propylene content of the propylene / 1-butene copolymer was 67.2 mol%. The above content is... 13 This was determined by 13C-NMR measurement.

[0193] [Production of crystalline modified olefin polymers] Three kilograms of propylene / 1-butene copolymer were added to 10 liters of toluene and heated to 145°C under a nitrogen atmosphere to dissolve the propylene / 1-butene copolymer in toluene. Then, under stirring, 382 g of maleic anhydride as a monomer and 175 g of di-tert-butyl peroxide as a radical polymerization initiator were added over 4 hours, followed by stirring at 145°C for 2 hours. This produced a maleic anhydride-modified propylene / 1-butene copolymer. The mixture was then cooled, a large amount of acetone was added to precipitate the maleic anhydride-modified propylene / 1-butene copolymer, followed by filtration, washing with acetone, and vacuum drying.

[0194] The melting point of the maleic anhydride-modified propylene / 1-butene copolymer was 75.8°C. The heat of fusion of the maleic anhydride-modified propylene / 1-butene copolymer, measured according to JIS K7122, was 28.6 J / g. The weight-average molecular weight of the maleic anhydride-modified propylene / 1-butene copolymer, measured by GPC and converted to standard polystyrene, was 100,000. In the maleic anhydride-modified propylene / 1-butene copolymer, the amount of monomer modification (introduced amount) was 1% by mass. The above modification amount is 1 This was determined by 1H-NMR measurement.

[0195] <Production of amorphous hydrocarbon polymers> Manufacturing Example 2 1 liter of dehydrated and purified hexane was added to a continuously polymerizing reactor equipped with a stirring blade that had been fully nitrogen-substituted, and ethylaluminum sesquichloride (Al(C2H5) 1.5 ·Cl 1.5 ) in hexane solution was continuously fed at a rate of 500 ml / hour for 1 hour. Then, a hexane solution of VO(OC2H5)C l2 adjusted to 16 mmol / l as a catalyst and hexane were continuously fed at a rate of 500 ml / hour. On the other hand, from the upper part of the polymerization reactor, the polymerization solution was continuously withdrawn so that the volume of the polymerization solution inside the combiner was always 1 liter. Next, ethylene gas was fed at a rate of 47 L / hour, propylene gas at a rate of 47 L / hour, and hydrogen gas at a rate of 20 L / hour using a bubbling tube. The copolymerization reaction was carried out at 35 °C by circulating a refrigerant through a jacket attached outside the polymerization reactor. The obtained polymerization solution was deashed with hydrochloric acid, then poured into a large amount of methanol for precipitation, and then dried under reduced pressure at 130 °C for 24 hours. Thereby, an ethylene / propylene copolymer was produced.

[0196] The ethylene content of the ethylene / propylene copolymer was 55.9 mol%. The above content was determined by 13 13C-NMR measurement. The weight average molecular weight of the ethylene / propylene copolymer was 14,000. The kinematic viscosity at 200 °C of the ethylene / propylene copolymer measured according to JIS K 2283 was 132 cSt.

[0197] [Preparation of Adhesive Composition] Example 1 [Preparation of Resin Composition] 100 parts by mass of the crystalline modified olefin polymer of Production Example 1 and 320 parts by mass of methylcyclohexane were blended in a flask equipped with a Dean-Stark apparatus and a stirring blade, and stirred for 3 hours under reflux conditions to dissolve the crystalline modified olefin polymer of Production Example 1. Then, it was cooled to 60 °C, and then 80 parts by mass of ethyl acetate was blended. Thereby, a varnish of the resin composition (solid content concentration: 20% by mass) was prepared. The acid value of the resin composition was 7.5 KOH mg / g.

[0198] [Preparation of adhesive composition] An adhesive composition was prepared by mixing 100 parts by mass of a resin composition with 50 parts by mass of an acid anhydride monomer (a solution of 0.3 parts by mass of PMDA dissolved in 49.7 parts by mass of ethyl acetate), a crosslinking agent (a solution of 10 parts by mass of jER152 dissolved in 40 parts by mass of ethyl acetate), and a catalyst (a solution of 0.8 parts by mass of DBU dissolved in 7.2 parts by mass of ethyl acetate).

[0199] Examples 2 to 8, and Comparative Examples 1 to 3 Adhesive compositions were prepared using the same procedure as in Example 1. However, in Examples 5 and 6, in preparing the resin composition, the crystalline modified olefin polymer from Production Example 1, the amorphous hydrocarbon polymer from Production Example 2 or Production Example 3, and 320 parts by mass of methylcyclohexane were mixed in a flask with a stirring blade fitted with a Dean-Stark apparatus, and stirred under reflux conditions for 3 hours to dissolve them. After that, the mixture was cooled to 60°C, and 80 parts by mass of ethyl acetate was added. This prepared the adhesive composition.

[0200] <Rating> [Acid value] In an Erlenmeyer flask, 35 ml of toluene and 15 ml of n-butanol were added. Then, 0.8 g of a diluted solution prepared by diluting 0.1 g of special grade bromothymol blue in 100 ml of 19% ethanol was added to prepare the solution. Next, N / KOH-ethanol solution was added to this solution until the solution turned green. Then, 5 g each of the varnish for the resin composition and the varnish for the adhesive composition of each example and comparative example were added and completely dissolved. This solution was then titrated with N / KOH-ethanol solution until it turned blue, the titration volume was measured, and the acid value was calculated based on the following formula (1). The results are shown in Table 1. Acid value (KOH mg / g) = (Sample titration volume × Factor × 5.61) / Sample weight (1) The sample weights mentioned above represent the weight of the solid content in the varnish of the resin composition.

[0201] [Adhesion during low-temperature lamination] The adhesive compositions of each example and each comparative example were applied to the other side in the thickness direction of the aluminum foil used as the base material and dried at 120°C for 30 seconds (dry film thickness approximately 3 μm). This formed the first adhesive layer on the other side in the thickness direction of the aluminum foil, thereby manufacturing a laminate. Next, the other side in the thickness direction of the first adhesive layer and the corona-treated surface of the CPP film (thickness 30 μm) used as the inner layer were bonded together on a hot plate at 60°C. After that, aging was performed at 60°C for 3 days. This manufactured the packaging material.

[0202] The obtained packaging material was cut into 15 mm wide test pieces, and a 180° peel test was performed on these test pieces using a universal tensile strength measuring device at a crosshead speed of 50 mm / min in a 23°C atmosphere to measure the peel strength of the aluminum foil / CPP. The results are shown in Table 1. In addition, the adhesion in a 23°C atmosphere was evaluated based on the following criteria. The results are shown in Table 1. (standard) ◎: The peel strength of the aluminum foil / CPP was 11N / 15mm or higher. ○: The peel strength of the aluminum foil / CPP was 9N / 15mm or higher and less than 11N / 15mm. ×: The peel strength of the aluminum foil / CPP was less than 9 N / 15 mm.

[0203] [Heat resistance] The above test specimens were subjected to a 180° peel test using a universal tensile testing device at a 120°C atmosphere and a crosshead speed of 50 mm / min to measure the heat resistance strength of the aluminum foil / CPP. Furthermore, the adhesion under a 120°C atmosphere was evaluated based on the following criteria. The results are shown in Table 1. (standard) ◎: The peel strength of the aluminum foil / CPP was 3N / 15mm or higher. ○: The peel strength of the aluminum foil / CPP was 2N / 15mm or higher and less than 3N / 15mm. ×: The peel strength of the aluminum foil / CPP was less than 2N / 15mm.

[0204] [Pot life] The adhesive compositions of each example and comparative example were placed in 50cc vials and immersed in a 25°C water bath. The viscosity (initial viscosity) was measured 30 minutes after immersion and the viscosity after 24 hours, and the viscosity increase rate was calculated based on the following formula (3). Viscosity increase (%) = Viscosity after 24 hours of immersion / Initial viscosity × 100 (3)

[0205] Furthermore, the usable time was evaluated based on the following criteria. The results are shown in Table 1. (standard) ◎: The thickening rate was 105% or less. ○: The viscosity was greater than 105% and less than or equal to 130%. 。 ×: The viscosity increased by more than 130%.

[0206] <Consideration> Examples 1 to 8, which contain an acid anhydride monomer having a ring structure and two acid anhydride groups, are found to have superior adhesion and heat resistance during low-temperature lamination compared to Comparative Example 1, which does not contain an acid anhydride monomer, and Comparative Example 2, which contains an acid anhydride monomer having a ring structure and one acid anhydride group (specifically, TH).

[0207] Furthermore, while Comparative Example 3, which uses an isocyanate compound as a crosslinking agent, exhibits reduced heat resistance, Examples 1 to 8, which use an epoxy compound or an oxazoline compound as a crosslinking agent, demonstrate excellent adhesion during low-temperature lamination as well as superior heat resistance.

[0208] [Table 1]

[0209] The above invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted restrictively. Modifications of the present invention that are obvious to those skilled in the art are included in the claims below. [Industrial applicability]

[0210] The adhesive composition, laminate, packaging material, and battery case packaging material of the present invention are suitably used, for example, in the manufacture of lithium battery case packaging material. [Explanation of Symbols]

[0211] 1. First adhesive layer 2 Base material 3. Inner layer 4. Second adhesive layer 5 Outer layer 10 Laminate 20 Packaging material 31 Packaging material for battery cases

Claims

1. Crystalline modified olefin polymers, Acid anhydride monomers and An adhesive composition comprising a crosslinking agent, The aforementioned crystalline modified olefin polymer is obtained by modifying a crystalline α-olefin polymer having 2 to 20 carbon atoms with a monomer having a functional group that can react with an epoxy group or an oxazoline group. The acid anhydride monomer has a ring structure and two or more acid anhydride groups. The crosslinking agent consists of an epoxy compound and / or an oxazoline compound. The acid value of the adhesive composition is 11.8 KOH mg / g or more and 21.6 KOH mg / g or less. The content ratio of the crosslinking agent is 8 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total amount of the crystalline modified olefin polymer, the acid anhydride monomer, and the crosslinking agent. An adhesive composition wherein the acid anhydride monomer is an aromatic ring-containing acid anhydride monomer.

2. Furthermore, the adhesive composition according to claim 1 comprises an amorphous hydrocarbon polymer having a kinematic viscosity of 1 cSt or more and 100,000 cSt or less at 200°C.

3. The adhesive composition according to claim 2, wherein the amorphous hydrocarbon polymer is a polymer of an olefin having 2 to 20 carbon atoms.

4. Furthermore, the adhesive composition according to claim 1, further comprising a catalyst.

5. The adhesive composition according to claim 4, wherein the catalyst is an amine catalyst.

6. The adhesive composition according to claim 1, wherein the functional group is an acid anhydride group.

7. A laminate comprising a first adhesive layer made of the adhesive composition according to any one of claims 1 to 6, and a substrate, arranged sequentially toward one side in the thickness direction.

8. A packaging material comprising an inner layer and the laminate described in claim 7, arranged sequentially toward one side in the thickness direction.

9. A battery case packaging material comprising the packaging material described in claim 8, a second adhesive layer, and an outer layer, arranged sequentially toward one side in the thickness direction.

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