Adhesive composition, laminate, packaging material, and packaging material for battery case

Abstract

To provide an adhesive composition that is superior in adhesion during low-temperature lamination, pot life and heat resistance, a laminate with an adhesive layer comprising a dried product of the adhesive composition, a packaging material comprising the laminate, and a packaging material for battery cases comprising the packaging material.SOLUTION: An adhesive composition comprises a crystalline modified olefinic polymer and a crosslinker. The crystalline modified olefinic polymer comprises a crystalline C2-20 α-olefinic polymer modified with a monomer having an acid anhydride group. In the crystalline modified olefinic polymer, the ring-opening rate of the cyclic structure derived from the acid anhydride group is 50% or more and 90% or less. The crosslinker comprises an epoxy compound and / or an oxazoline compound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In recent years, from the viewpoint of achieving thinner designs, lithium batteries have been used as batteries for personal computers, portable terminal devices, etc. The lithium batteries are sealed, for example, in packaging.

[0003] Such a packaging material 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 has been proposed that contains a polyolefin having an acid anhydride group and an isocyanate compound as a crosslinking agent, in which the anhydride ring opening rate in the polyolefin having an acid anhydride group is 40% (see, for example, Example 3 of Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 090818 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] However, such adhesives are required to have heat resistance.

[0007] On the other hand, the adhesive composition of Patent Document 1 uses an isocyanate compound as a crosslinking agent, which causes a problem of reduced heat resistance.

[0008] Furthermore, from the viewpoint of improving productivity, such adhesives are required to have good adhesion and long usable life during low-temperature lamination.

[0009] The present invention provides an adhesive composition that exhibits excellent adhesion, usable life, and heat resistance during low-temperature lamination, a laminate having an adhesive layer made of a dried product of the adhesive composition, a packaging material having the laminate, and a packaging material for battery cases having the packaging material. [Means for solving the problem]

[0010] The present invention [1] is an adhesive composition comprising a crystalline modified olefin polymer and a crosslinking agent, wherein the crystalline modified olefin polymer is obtained by modifying a crystalline α-olefin polymer having 2 to 20 carbon atoms with a monomer having an acid anhydride group, wherein the ring-opening rate of ring structures derived from the acid anhydride group in the crystalline modified olefin polymer is 50% or more and 90% or less, and the crosslinking agent comprises an epoxy compound and / or an oxazoline compound.

[0011] The present invention [2] further includes the adhesive composition according to the above [1], which contains a non-crystalline hydrocarbon polymer having a kinematic viscosity at 200°C of 1 cSt or more and 100,000 cSt or less.

[0012] The present invention [3] includes the adhesive composition according to the above [2], in which the amorphous hydrocarbon polymer is a polymer of an olefin having 2 to 20 carbon atoms.

[0013] The present invention [4] includes the adhesive composition according to any one of the above [1] to [3], which further contains a catalyst.

[0014] The present invention [5] includes a laminate having, in order toward one side in the thickness direction, a first adhesive layer made of a dried product of the adhesive composition described in any one of [1] to [4] above and a substrate.

[0015] The present invention [6] includes a packaging material having an inner layer and the laminate described in [5] above, arranged in this order toward one side in the thickness direction.

[0016] The present invention [7] includes a packaging material for battery cases, which comprises the packaging material described in [6] above, a second adhesive layer, and an outer layer in this order toward one side in the thickness direction. [Effects of the Invention]

[0017] In the adhesive composition of the present invention, the crystalline modified olefin polymer has a ring opening rate of 50% or more and 90% or less of the ring structure derived from the acid anhydride group, which results in excellent adhesion and a long usable time during low-temperature lamination.

[0018] In addition, the crosslinking agent contains an epoxy compound and / or an oxazoline compound, which provides excellent heat resistance.

[0019] The laminate of the present invention has a first adhesive layer made of a dried product of the adhesive composition of the present invention, and therefore has excellent adhesion and heat resistance during low-temperature lamination.

[0020] The packaging material of the present invention includes the laminate of the present invention, and therefore has excellent adhesion and heat resistance during low-temperature lamination.

[0021] The battery case packaging material of the present invention includes the packaging material of the present invention, and therefore has excellent adhesion and heat resistance during low-temperature lamination. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic diagram showing one embodiment of the laminate of the present invention. [Figure 2]2A and 2B show one embodiment of the method for producing a laminate of the present invention. Fig. 2A shows the first step of preparing a substrate. Fig. 2B shows the second step of arranging (forming) a first adhesive layer on the other surface of the substrate in the thickness direction. [Figure 3] FIG. 3 is a schematic diagram showing one embodiment of the packaging material of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing one embodiment of a battery case packaging material of the present invention and a battery using this battery case packaging material. DETAILED DESCRIPTION OF THE INVENTION

[0023] 1. Adhesive composition The adhesive composition includes a crystalline modified olefin polymer and a crosslinking agent.

[0024] <Crystalline modified olefin polymer> The crystalline modified olefin polymer is obtained by modifying a crystalline α-olefin polymer having 2 to 20 carbon atoms with a monomer having an acid anhydride group.

[0025] [Crystalline α-olefin polymers having 2 to 20 carbon atoms] A crystalline α-olefin polymer having 2 to 20 carbon atoms is an olefin polymer containing structural units derived from an α-olefin having 2 to 20 carbon atoms, which can form a crystalline polymer. That is, a crystalline α-olefin polymer having 2 to 20 carbon atoms is obtained by polymerizing an α-olefin having 2 to 20 carbon atoms. Crystallinity is defined as a property of a compound having a heat of fusion of 1 J / g or more.

[0026] 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.

[0027] The structural units derived from an α-olefin having 2 to 20 carbon atoms are preferably structural units derived from an α-olefin having 2 to 4 carbon atoms. More preferably, the structural units derived from an α-olefin having 2 to 20 carbon atoms are structural units derived from propylene and structural units derived from 1-butene. In other words, the crystalline polymer of an α-olefin having 2 to 20 carbon atoms is preferably a propylene / 1-butene copolymer.

[0028] The type and content of the structural unit derived from an α-olefin having 2 to 20 carbon atoms are selected so that the olefin polymer is crystalline.

[0029] Specifically, when the structural units derived from an α-olefin having 2 to 20 carbon atoms include structural units derived from propylene and structural units derived from 1-butene, the content of the structural units derived from propylene relative to 100 mol% of the total amount of the structural units derived from propylene and 1-butene is, for example, 50 mol% or more, preferably 60 mol% or more, and for example, 95 mol% or less, preferably 80 mol% or less. Furthermore, the content of the structural units derived from 1-butene relative to 100 mol% of the total amount of the structural units derived from propylene and 1-butene is, for example, 5 mol% or more, preferably 20 mol% or more, and for example, 50 mol% or less, preferably 40 mol% or less.

[0030] When the content ratio of the propylene-derived structural unit and the content ratio of the 1-butene-derived structural unit are equal to or greater than the above lower limit and equal to or less than the above upper limit, excellent adhesion is achieved during low-temperature lamination.

[0031] The above content ratio may be, for example, 13 This can be confirmed by known means such as C-NMR measurement (the same applies below).

[0032] Crystalline α-olefin polymers having 2 to 20 carbon atoms can be obtained by, for example, the methods described in Japanese Patent No. 3939464 and International Publication No. 2004 / 87775. Specifically, crystalline α-olefin polymers having 2 to 20 carbon atoms can be obtained by polymerizing an α-olefin having 2 to 20 carbon atoms in the presence of a metallocene catalyst.

[0033] The heat of fusion of the crystalline α-olefin polymer having 2 to 20 carbon atoms, measured in accordance with JIS K7122, is, for example, 1 J / g or more, preferably 10 J / g or more, more preferably 20 J / g or more, and for example, 50 J / g or less, preferably 40 J / g or less.

[0034] When the heat of fusion is equal to or greater than the above lower limit and equal to or less than the above upper limit, the adhesiveness during low-temperature lamination is excellent.

[0035] The melting point of the crystalline α-olefin polymer having 2 to 20 carbon atoms is, for example, 40°C or higher, or preferably 60°C or higher, and for example, 100°C or lower, or preferably 80°C or lower.

[0036] The melting point can be measured by a differential scanning calorimeter (the same applies hereinafter).

[0037] The weight average molecular weight of the crystalline α-olefin polymer having 2 to 20 carbon atoms, measured by GPC, is, for example, 10,000 or more, preferably 50,000 or more, and for example, 500,000 or less, preferably 300,000 or less, more preferably 150,000.

[0038] The crystalline α-olefin polymers having 2 to 20 carbon atoms can be used alone or in combination of two or more kinds.

[0039] [Monomer] The monomer has an acid anhydride group, and examples of the monomer include unsaturated carboxylic acid anhydrides.

[0040] Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic anhydride. A preferred monomer is maleic anhydride.

[0041] The monomers can be used alone or in combination of two or more kinds.

[0042] [Production of crystalline modified olefin polymer] The crystalline modified olefin polymer can be obtained by modifying a crystalline α-olefin polymer having 2 to 20 carbon atoms with a monomer.

[0043] To modify a crystalline α-olefin polymer having 2 to 20 carbon atoms with a monomer, for example, the crystalline α-olefin polymer having 2 to 20 carbon atoms is first dissolved in a known organic solvent (for example, toluene).

[0044] Next, the monomer and the radical polymerization initiator are added, and the mixture is heated and stirred.

[0045] The modification amount (introduction amount) of the monomer in the crystalline α-olefin polymer having 2 to 20 carbon atoms, i.e., the content ratio of structural units derived from the monomer in the crystalline α-olefin polymer having 2 to 20 carbon atoms, is, for example, 0.1 mass% or more, preferably 0.5 mass% or more, and for example, 15 mass% or less, preferably 10 mass% or less, more preferably 5 mass% or less, even more preferably 4 mass% or less, particularly preferably 2 mass% or less, and most preferably 1 mass% or less, relative to the crystalline α-olefin polymer having 2 to 20 carbon atoms.

[0046] When the modification amount is equal to or greater than the lower limit and equal to or less than the upper limit, the pot life can be improved.

[0047] The above-mentioned modification amount is, for example, 1 This can be confirmed by known means such as H-NMR measurement.

[0048] Examples of the radical polymerization initiator include organic peroxides and organic peresters.

[0049] Examples of organic peroxides include dicumyl peroxide, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(peroxybenzoate)hexyne-3, 1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-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. Further, other azo compounds such as azobis-isobutylnitrile and dimethylazoisobutylnitrile may also be used as the radical polymerization initiator.

[0050] Of the radical polymerization initiators, preferred are organic peroxides, and more preferred is di-tert-butyl peroxide.

[0051] The mixing ratio of the radical polymerization initiator relative to 100 parts by mass of the crystalline α-olefin polymer having 2 to 20 carbon atoms is, for example, 0.001 parts by mass or more and, for example, 10 parts by mass or less.

[0052] The radical polymerization initiators can be used alone or in combination of two or more kinds.

[0053] The heating temperature is, for example, 50° C. or higher, preferably 80° C. or higher, and, for example, 250° C. or lower. The reaction time is, for example, 1 minute or longer and 10 hours or shorter.

[0054] In this way, the crystalline α-olefin polymer having 2 to 20 carbon atoms is modified with the monomer, and a crystalline modified olefin polymer (a crystalline modified olefin polymer varnish) is obtained.

[0055] The melting point of the crystalline modified olefin polymer is, for example, 40°C or higher, or preferably 60°C or higher, and for example, 100°C or lower, or preferably 80°C or lower.

[0056] The weight average molecular weight of the crystalline modified olefin polymer measured by GPC is, for example, 10,000 or more, preferably 50,000 or more, and for example, 500,000 or less, preferably 300,000 or less, more preferably 200,000.

[0057] In addition, in the crystalline modified olefin polymer, the ring-opening rate of the ring structure derived from the acid anhydride group is 50% or more and 90% or less.

[0058] When the ring-opening ratio is equal to or higher than the lower limit, adhesion during low-temperature lamination is improved.

[0059] On the other hand, if the ring-opening ratio is less than the lower limit, the adhesion during low-temperature lamination will decrease.

[0060] Furthermore, if the ring-opening ratio is equal to or less than the upper limit, the pot life is improved.

[0061] On the other hand, if the ring-opening rate exceeds the upper limit, the pot life decreases.

[0062] That is, as will be described in detail later, as the ring-opening rate increases, the adhesion during low-temperature lamination improves, while as the ring-opening rate decreases, the usable time tends to improve.

[0063] Specifically, from the viewpoint of adhesion during low-temperature lamination, the ring-opening ratio is 50% or more, preferably 55% or more, more preferably 60% or more, even more preferably 70% or more, and 90% or less, preferably 80% or less.

[0064] From the viewpoint of usable life, the ring-opening rate is 50% or more, preferably 55% or more, and 90% or less, preferably 80% or less, more preferably 70% or less, and even more preferably 60% or less.

[0065] The ring-opening ratio can be adjusted by dissolving the crystalline modified olefin polymer produced as described above in a solvent (described later) and by adjusting the dissolution temperature and dissolution time. Specifically, for example, in the preparation of an adhesive composition (described later), the ring-opening ratio can be adjusted by adjusting the dissolution temperature and dissolution time when dissolving a mixture of the crystalline modified olefin polymer and an optionally blended amorphous hydrocarbon polymer (described later) in a solvent (described later).

[0066] Specifically, when the dissolution temperature is high (or the dissolution time is long), the water contained in the crystalline modified olefin polymer and / or the solvent (described later) is removed, and the amount of water in the adhesive composition tends to be reduced, which can suppress ring-opening of the acid anhydride group due to reaction with water, and as a result, the ring-opening rate can be reduced.

[0067] On the other hand, if the dissolution temperature is low (or the dissolution time is short), water contained in the crystalline modified olefin polymer and / or the solvent (described later) remains, and the adhesive composition tends to contain a large amount of water, which makes it easier for the ring-opening of the acid anhydride group due to the reaction with water to proceed, thereby increasing the ring-opening rate.

[0068] The method for measuring the ring-opening ratio will be described in detail in the Examples below.

[0069] The content of the crystalline modified olefin polymer in the adhesive composition will be described later.

[0070] <Crosslinking agent> The crosslinking agent includes an epoxy compound and / or an oxazoline compound.

[0071] 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-type epoxy resins, hydrogenated bisphenol-type epoxy resins, and amine-type epoxy resins.Preferably, the epoxy compounds include novolac-type epoxy resins.More preferably, the epoxy compounds include phenol novolac-type epoxy resins.

[0072] Examples of the oxazoline compound include an oxazoline group-containing polymer, such as a homopolymer of an oxazoline group-containing monomer and a copolymer of an oxazoline group-containing monomer and another monomer copolymerizable with the oxazoline group-containing monomer.

[0073] 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.

[0074] Other monomers copolymerizable with the oxazoline group-containing monomer include, for example, (meth)acrylic acid alkyl esters, 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).

[0075] The oxazoline compound is preferably a copolymer of an oxazoline group-containing monomer and another monomer copolymerizable with the oxazoline group-containing monomer, and more preferably an oxazoline group-containing polystyrene.

[0076] The crosslinking agent preferably contains an epoxy compound or an oxazoline compound, and more preferably contains an epoxy compound but does not contain an oxazoline compound, from the viewpoint of improving adhesion and heat resistance during low-temperature lamination.

[0077] The crosslinking agents can be used alone or in combination of two or more.

[0078] The content of the crosslinking agent in the adhesive composition will be described later.

[0079] <Non-crystalline hydrocarbon polymer> The adhesive composition may optionally contain an amorphous hydrocarbon polymer to improve adhesion and usable life during low-temperature lamination. 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.

[0080] The amorphous hydrocarbon polymer is a polymer containing structural units derived from a hydrocarbon. As the hydrocarbon, an olefin having 2 to 20 carbon atoms is preferably used from the viewpoints of low-temperature adhesion and adhesion to an olefin substrate. In other words, the amorphous hydrocarbon polymer is preferably an olefin polymer containing structural units derived from an olefin having 2 to 20 carbon atoms. In other words, the amorphous hydrocarbon polymer is preferably a polymer of an olefin having 2 to 20 carbon atoms.

[0081] 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. Preferred examples of olefins having 2 to 20 carbon atoms include olefins having 2 to 4 carbon atoms. More preferred examples of olefins having 2 to 20 carbon atoms include ethylene, propylene, and isobutylene. More preferably, the olefin having 2 to 20 carbon atoms is a combination of ethylene and propylene, or isobutylene alone. That is, more preferably, the amorphous hydrocarbon polymer is an ethylene / propylene copolymer or polyisobutylene.

[0082] The type and content of the hydrocarbon-derived structural unit are selected so that the hydrocarbon polymer is non-crystalline.

[0083] Specifically, when the hydrocarbon-derived structural units include ethylene-derived structural units and propylene-derived structural units, the content of the ethylene-derived structural units relative to 100 mol% of the total of the ethylene-derived structural units and the propylene-derived structural units is, for example, 40 mol% or more, preferably 50 mol% or more, and for example, 80 mol% or less, preferably 60 mol% or less. Furthermore, relative to 100 mol% of the total of the ethylene-derived structural units and the propylene-derived structural units, the content of the propylene-derived structural units is, for example, 20 mol% or more, preferably 40 mol% or more, and for example, 60 mol% or less, preferably 50 mol% or less.

[0084] When the content ratio of the ethylene-derived structural unit and the content ratio of the propylene-derived structural unit are equal to or greater than the above lower limit and equal to or less than the above upper limit, the adhesiveness during low-temperature lamination is excellent.

[0085] The non-crystalline hydrocarbon polymer can be produced by the same method as the method for producing the crystalline α-olefin polymer having 2 to 20 carbon atoms exemplified above as the crystalline modified olefin polymer.

[0086] The kinematic viscosity of the amorphous hydrocarbon polymer 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 kinematic viscosity. Specifically, amorphous hydrocarbon polymers having a 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, more preferably 500 cSt or less, are amorphous hydrocarbon synthetic oils. Furthermore, amorphous hydrocarbon polymers having a kinematic viscosity of more than 10,000 cSt, preferably 30,000 cSt or more, and 100,000 cSt or less, preferably 60,000 cSt or less, are amorphous hydrocarbon semi-solid resins.

[0087] If the kinematic viscosity at 200°C is equal to or higher than the above lower limit and equal to or lower than the above upper limit, the adhesiveness during low-temperature lamination can be improved.

[0088] The kinematic viscosity at 200°C can be measured in accordance with JIS K 2283.

[0089] The weight average molecular weight of the amorphous hydrocarbon polymer measured by GPC is, for example, 5,000 or more, and, for example, 300,000 or less. Specifically, when the amorphous hydrocarbon polymer is an amorphous hydrocarbon synthetic oil, the 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, and even more preferably 20,000 or less. When the amorphous hydrocarbon polymer is an amorphous hydrocarbon semi-solid resin, the weight average molecular weight is, for example, 5,000 or more, preferably 10,000 or more, more preferably 50,000 or more, more preferably 100,000 or more, and even more preferably 120,000 or more, and, for example, 300,000 or less, preferably 200,000 or less, and more preferably 160,000 or less.

[0090] The amorphous hydrocarbon polymers can be used alone or in combination of two or more kinds.

[0091] The content of the non-crystalline hydrocarbon polymer in the adhesive composition will be described later.

[0092] <Catalyst> The adhesive composition may contain a catalyst to promote the crosslinking reaction of the crosslinking agent. Examples of the catalyst include a strongly basic tertiary amine (e.g., 1,8-diazabicyclo[5.4.0]undecene-7 (DBU) or 1,6-diazabicyclo[3.4.0]-5-nonene), and a phosphazene catalyst having a phosphazene base. A strongly basic tertiary amine is preferred. A more preferred catalyst is DBU.

[0093] The catalysts can be used alone or in combination of two or more.

[0094] The content of the catalyst in the adhesive composition will be described later.

[0095] <Additives> The adhesive composition may contain additives in appropriate proportions, if necessary.

[0096] Examples of additives include leveling agents, antifoaming agents, antioxidants, heat stabilizers, ultraviolet absorbers, plasticizers, surfactants, pigments, thixotropic agents, thickeners, tackifiers, surface conditioners, antisettling agents, weathering agents, pigment dispersants, antistatic agents, fillers, antifungal agents, and silane coupling agents.

[0097] The additives can be used alone or in combination of two or more kinds.

[0098] <Preparation of Adhesive Composition> To prepare the adhesive composition, a crystalline modified olefin polymer, a crosslinking agent, an optionally blended amorphous hydrocarbon polymer, an optionally blended catalyst, and optionally blended additives are mixed.

[0099] Specifically, a mixture of a crystalline modified olefin polymer and an optionally blended amorphous hydrocarbon polymer is first dissolved in a solvent to prepare a resin composition. In other words, in this case, the resin composition contains a crystalline modified olefin polymer, an optionally blended amorphous hydrocarbon polymer, and a solvent.

[0100] Examples of solvents include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ketones, alkyl esters, glycol ether esters, ethers, and polar aprotic solvents. 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 aprotic solvents include N-methylpyrrolidone, dimethylformamide, N,N'-dimethylacetamide, dimethyl sulfoxide, and hexamethylphosphonylamide.

[0101] The solvent is preferably an alicyclic hydrocarbon or an alkyl ester, more preferably methylcyclohexane or ethyl acetate.

[0102] The solvents can be used alone or in combination of two or more kinds.

[0103] The blending ratio of the solvent is, 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 blended as necessary.

[0104] The dissolution temperature is, for example, 40°C or higher and, for example, 110°C or lower.

[0105] As described above, when the dissolution temperature is increased, the ring-opening rate tends to decrease, whereas when the dissolution temperature is decreased, the ring-opening rate tends to increase.

[0106] Specifically, from the viewpoint of reducing the ring-opening rate, the dissolution temperature is, for example, 40°C or higher, preferably 70°C or higher, more preferably 90°C or lower, and even more preferably 100°C or higher, and for example, 110°C or lower.

[0107] From the viewpoint of increasing the ring-opening rate, the dissolution temperature is, for example, 40°C or higher, preferably 50°C or higher, and for example, 110°C or lower, preferably 90°C or lower, more preferably 70°C or lower.

[0108] The dissolution time is, for example, 1 hour or more and, for example, 4 hours or less.

[0109] As described above, when the dissolution time is increased, the ring-opening rate tends to decrease, whereas when the dissolution time is decreased, the ring-opening rate tends to increase.

[0110] In this way, a resin composition is prepared.

[0111] The acid value of the solid content in the resin composition is, for example, 1.00 KOHmg / g or more, preferably 5.00 KOHmg / g or more, and for example, 20.00 mg / g or less, preferably 10.00 mg / g or less, more preferably 8.00 mg / g or less.

[0112] The method for measuring the acid value will be described in detail in the Examples below.

[0113] Next, a crosslinking agent, a catalyst which is blended as required, and additives which are blended as required are blended into the resin composition.

[0114] This results in the preparation of an adhesive composition, which contains a crystalline modified olefin polymer, an optionally blended amorphous hydrocarbon polymer, a crosslinking agent, an optionally blended catalyst, an optionally blended additive, and a solvent.

[0115] When 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, per 100 parts by mass of the total amount of the crystalline modified olefin polymer and the amorphous hydrocarbon polymer. 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, preferably 30 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.

[0116] The content ratio of the crosslinking agent relative to 100 parts by mass of the crystalline modified olefin polymer is, for example, 5 parts by mass or more, and for example, 20 parts by mass or less, preferably 15 parts by mass or less.

[0117] Furthermore, when the adhesive composition contains an amorphous hydrocarbon polymer, the content of the crosslinking agent is, for example, 5 parts by mass or more and, for example, 20 parts by mass or less, preferably 12 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.

[0118] The catalyst content is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and for example, 5 parts by mass or less, preferably 3 parts by mass or less, relative to 100 parts by mass of the crystalline modified olefin polymer.

[0119] Furthermore, when the adhesive composition contains an amorphous hydrocarbon polymer, the catalyst content is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and for example, 5 parts by mass or less, preferably 3 parts by mass or less, more preferably 1 part by mass or less, per 100 parts by mass of the total amount of the crystalline modified olefin polymer and the amorphous hydrocarbon polymer.

[0120] The adhesive composition can also be diluted with the above-mentioned solvent during and / or after the preparation.

[0121] When the adhesive composition is diluted, the solid content concentration of the adhesive composition is, for example, 10% by mass or more and, for example, 70% by mass or less.

[0122] <Action and effect> In the adhesive composition, the ring opening rate of the ring structure derived from the acid anhydride group in the crystalline modified olefin polymer is 50% or more and 90% or less, which results in excellent adhesion and usable life during low-temperature lamination.

[0123] Specifically, as the ring-opening rate increases, the polarity increases and the compatibility with crosslinking agents (crosslinking agents with high polarity) improves, which facilitates the crosslinking reaction and improves adhesion during low-temperature lamination.

[0124] On the other hand, if the ring-opening rate is low, the polarity is low and the compatibility with crosslinking agents (crosslinking agents with high polarity) is low, which makes it difficult for the crosslinking reaction to proceed and improves the usable time.

[0125] That is, in this adhesive composition, by adjusting the ring opening rate to 50% or more and 90% or less, it is possible to improve both the adhesion during low-temperature lamination and the usable time.

[0126] In addition, in this adhesive composition, first, a crystalline α-olefin polymer having 2 to 20 carbon atoms is modified with a monomer having an acid anhydride group to produce a crystalline modified olefin polymer, and then this crystalline modified olefin polymer is dissolved in a solvent to prepare a resin composition, during which the ring structure derived from the acid anhydride group is opened to adjust the ring-opening rate. In other words, the ring-opening rate is adjusted after modification.

[0127] Therefore, according to this method, the ring-opening rate can be adjusted without changing the amount of modification.

[0128] On the other hand, it may also be considered to modify the α-olefin polymer in advance with a ring-opened monomer or an unsaturated carboxylic acid (for example, maleic acid), and adjust the ring-opening rate by the degree of modification.

[0129] However, since carboxylic acids have low compatibility with α-olefin polymers, the degree of modification cannot be increased, which causes the problem that the ring-opening rate cannot be sufficiently adjusted.

[0130] In contrast, according to the above method, the ring-opening rate is adjusted after modification. Therefore, the ring-opening rate can be easily adjusted. Furthermore, the α-olefin polymer and the monomer having an acid anhydride group have excellent compatibility. Therefore, the modification can be easily carried out, and productivity is excellent.

[0131] Furthermore, the adhesive composition exhibits excellent adhesion during low-temperature lamination even without containing a catalyst.

[0132] Specifically, as described above, the crosslinking reaction can be promoted by adjusting the ring-opening rate in the adhesive composition to 50% or more and 90% or less, and therefore the adhesive composition has excellent adhesion during low-temperature lamination even without containing a catalyst.

[0133] Furthermore, when the adhesive composition contains a catalyst, the acid anhydride group may react excessively with the catalyst, resulting in deactivation of the catalyst. On the other hand, in this adhesive composition, by increasing the ring-opening rate (50% to 90%), the deactivation can be suppressed, thereby improving adhesion during low-temperature lamination.

[0134] Furthermore, in the adhesive composition, the crosslinking agent contains an epoxy compound and / or an oxazoline compound, which results in excellent heat resistance.

[0135] More specifically, the adhesive composition of Patent Document 1 improves the usable time by reducing the ring-opening rate of the polyolefin having an acid anhydride group, while improving adhesion during low-temperature lamination by using a highly reactive isocyanate compound (crosslinking agent). However, the use of an isocyanate compound as a crosslinking agent has the drawback of reducing heat resistance.

[0136] In contrast, the adhesive composition uses a crosslinking agent containing an epoxy compound and / or an oxazoline compound to improve heat resistance. However, such crosslinking agents tend to have lower adhesion during low-temperature lamination compared to isocyanate compounds due to their low reactivity. Therefore, the adhesive composition improves adhesion during low-temperature lamination by increasing the ring-opening ratio.

[0137] As described above, the adhesive composition can improve adhesion during low-temperature lamination, pot life, and heat resistance.

[0138] The adhesive composition has excellent adhesion, usable life, and heat resistance during low-temperature lamination, and can therefore be suitably used, for example, as an adhesive (dry lamination adhesive) for various components (e.g., electronic components, optical components, and battery components), and in particular, as an adhesive for packaging materials for battery cases.

[0139] In the following description, a laminate having an adhesive layer made of a dried product of the adhesive composition, a packaging material having the laminate, and a packaging material for a battery case having the packaging material will be described in detail.

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

[0141] In Figure 1, the up-down direction of the paper surface is the up-down direction (thickness direction), and the upper side of the paper surface is the upper side (one side in the thickness direction), and the lower side of the paper surface is the lower side (the other side in the thickness direction). Also, the left-right direction and the depth direction of the paper surface are surface directions perpendicular to the up-down direction. Specifically, they conform 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 plane direction perpendicular to the thickness direction. The laminate 10 has a flat upper surface and a flat lower surface.

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

[0144] There are no particular limitations on the thickness of the laminate 10. The thickness of the laminate 10 is, for example, 10 μm or more and, for example, 150 μm or less.

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

[0146] Next, to arrange (form) the first adhesive layer 1, an adhesive composition is applied to the other surface in the thickness direction of the substrate 2, and if necessary, heated and dried, as described in detail below. In this way, the first adhesive layer 1 is arranged (formed).

[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 substrate 2 has a film shape (including a sheet shape) with a predetermined thickness.

[0149] The material of the substrate 2 is not particularly limited. Examples of materials for the substrate 2 include polymeric materials and metal materials. Examples of polymeric materials include olefin resins (e.g., polyethylene and 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 metal materials include aluminum, gold, silver, copper, nickel, zinc, titanium, cobalt, indium, and chromium.

[0150] There is no particular limitation on the thickness of the substrate 2. The thickness of the substrate 2 is, for example, 10 μm or more and, for example, 100 μm or less.

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

[0152] The method for manufacturing the laminate 10 includes a first step of preparing a substrate 2, and a second step of applying an adhesive composition to the other thickness-wise surface of the substrate 2 and arranging (forming) a first adhesive layer 1 on the other thickness-wise surface of the substrate 2.

[0153] In the first step, a substrate 2 is prepared as shown in FIG. 2A.

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

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

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

[0157] Examples of the surface treatment include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment, and preferably corona treatment.

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

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

[0160] As a result, the first adhesive layer 1, which is a dried product of the adhesive composition, is disposed (formed) on the other surface in the thickness direction of the substrate 2. In this way, the laminate 10 is produced.

[0161] Such a laminate 10 includes a first adhesive layer 1 made of a dried 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 FIG.

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

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

[0165] There are no particular limitations on the thickness of the packaging material 20. The thickness of the packaging material 20 is, for example, 15 μm or more and, for example, 300 μm or less.

[0166] Inner Layer The inner layer 3 is a layer that becomes the inside when the packaging material 20 is made into a bag shape.

[0167] The material of the inner layer 3 is appropriately selected depending on whether the packaging material 20 has heat sealing properties and the type of contents to be contained in the bag when the packaging material 20 is formed into a bag. As will be described in detail later, when the contents to be contained are an electrolyte solution, a polyolefin film is selected.

[0168] There are no particular limitations on the thickness of the inner layer 3. The thickness of the inner layer 3 is, for example, 30 μm or more and, for example, 600 μm or less.

[0169] [Packaging manufacturing] To manufacture the packaging material 20, the inner layer 3 is placed on the other surface in the thickness direction of the laminate 10 (the other surface in the thickness direction of the first adhesive layer 1), and the first adhesive layer 1 is aged. This hardens the first adhesive layer 1, and the inner layer 3 and the laminate 10 are bonded together. In this way, the packaging material 20 is manufactured.

[0170] The aging temperature is low because the packaging material 20 includes the laminate 10. Specifically, the aging temperature 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 longer, and, for example, 7 days or shorter, preferably 5 days or shorter.

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

[0172] 4. Battery case packaging and batteries Referring to FIG. 4, one 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 includes a battery case packaging material 31 and an electrolyte 32 packaged in the battery case packaging material 31. The battery 30 also includes a positive electrode 33, a negative electrode 34, and a separator 35 housed in the battery case packaging material 31.

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

[0175] 4A, the battery case packaging material 31 includes a packaging material 20 (the packaging material 20 including an inner layer 3, a first adhesive layer 1, and a base material 2, in that order toward one side in the thickness direction), a second adhesive layer 4, and an outer layer 5, in that order toward one side in the thickness direction. Specifically, the battery case packaging material 31 includes the packaging material 20, the second adhesive layer 4 disposed directly on the upper surface (one side in the thickness direction) of the packaging material 20, and the outer layer 5 disposed directly on the upper surface (one side in the thickness direction) of the second adhesive layer 4.

[0176] As described above, the packaging material 20 includes the inner layer 3, the first adhesive layer 1, and the base material 2, arranged in this order toward one side in the thickness direction. In the battery case packaging material 31, a polyolefin film is selected for the inner layer 3 from the viewpoint of chemical resistance (electrolyte resistance) to the electrolyte solution 32. Examples of polyolefin films include polyethylene-based films and polypropylene-based films. Examples of polyethylene-based films include low-density polyethylene films (LDPE) and linear low-density polyethylene films (LLDPE). Examples of polypropylene-based films include oriented polypropylene films (CPP films), uniaxially oriented polypropylene films, and biaxially oriented polypropylene films (OPP films). A preferred example of the polyolefin film is a polypropylene-based film. A more preferred example of the polyolefin film is an oriented polypropylene film (CPP film).

[0177] In the battery case packaging material 31, the material of the substrate 2 is preferably a metal material, and more preferably aluminum.

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

[0179] There are no particular limitations on the thickness of the second adhesive layer 4. The thickness of the inner layer 3 is, for example, 1 μm or more and, for example, 50 μm or less.

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

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

[0182] There are no particular limitations on the thickness of the outer layer 5. The thickness of the outer layer 5 is, for example, 10 μm or more and, for example, 100 μm or less.

[0183] The packaging material 31 for the battery case is manufactured by arranging an outer layer 5 on one thickness-wise surface of the packaging material 20 (one thickness-wise surface of the substrate 2) via a second adhesive layer 4 formed by applying a known adhesive (or adhesive composition).

[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] In addition, in FIG. 4, both ends (opposing inner layers 3) of the battery case packaging material 31 are sealed by heat sealing to form a bag.

[0186] [Electrolyte] The electrolytic solution 32 is not particularly limited, and may contain, for example, ethylene carbonate, diethyl carbonate, dimethyl carbonate, and a lithium salt such as lithium hexafluorophosphate.

[0187] The positive electrode 33 and the negative electrode are disposed facing each other with a gap therebetween so as to be in contact with the electrolyte solution 32. The separator is disposed so as to be sandwiched between the positive electrode 33 and the negative electrode .

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

[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. Note that "parts" and "%" are by mass unless otherwise specified. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used in the following description can be substituted with the corresponding upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or more than" or "exceeding") of the blending ratios (content ratios), physical property values, parameters, etc. described in the above "Form for Carrying Out the Invention."

[0190] <Ingredient details> The trade names and abbreviations of the components used in each Production Example, each Example, and each Comparative Example are described in detail below. Oppanol B15SFN: Amorphous hydrocarbon polymer, polyisobutylene, weight average molecular weight: 106,000, kinematic viscosity at 200°C measured according to JIS K 2283: 52,000 cSt, manufactured by BASF jER152: Phenol novolac epoxy resin, manufactured by Mitsubishi Chemical Corporation RPS-1005: Oxazoline group-containing polystyrene, manufactured by Nippon Shokubai Co., Ltd. D-127N: Isocyanate compound, manufactured by Mitsui Chemicals, Inc. DBU: 1,8-diazabicyclo[5.4.0]undecene-7, manufactured by San-Apro Co., Ltd.

[0191] <Production of crystalline modified olefin polymer> Manufacturing Example 1 [Production of crystalline α-olefin polymers having 2 to 20 carbon atoms] A 2-liter autoclave, the atmosphere of which had been thoroughly purged with nitrogen, was charged with 900 ml of hexane and 90 g of 1-butene. Then, 1 mmol of triisobutylaluminum was added, and the temperature was raised to 70°C. Propylene was then supplied to the autoclave to maintain a total pressure of 7 kg / cm. 2The temperature was adjusted to G, 0.30 mmol of methylaluminoxane and 0.001 mmol of rac-dimethylsilylene-bis{1-(2-methyl-4-phenylindenyl)}zirconium dichloride (calculated as Zr atom) were added, and propylene was continuously supplied to maintain the total pressure at 7 kg / cm. 2 The mixture was polymerized for 30 minutes while maintaining the temperature at 50°C. This produced a propylene / 1-butene copolymer (a crystalline α-olefin polymer having 2 to 20 carbon atoms). After polymerization, the mixture was degassed and the propylene / 1-butene copolymer was recovered in a large amount of methanol and 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 in accordance with JIS K7122, was 29.2 J / g. The weight average molecular weight of the propylene / 1-butene copolymer, measured by GPC, was 330,000. The propylene content of the propylene / 1-butene copolymer was 67.2 mol%.

[0193] [Production of crystalline modified olefin polymer] 3 kg of propylene / 1-butene copolymer was added to 10 L of toluene and heated to 145°C under a nitrogen atmosphere to dissolve the propylene / 1-butene copolymer in toluene. Furthermore, with 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, and the mixture was then stirred at 145°C for 2 hours. This produced a maleic anhydride-modified propylene / 1-butene copolymer. The mixture was then cooled, and a large amount of acetone was added to precipitate the maleic anhydride-modified propylene / 1-butene copolymer. The copolymer was then filtered, washed with acetone, and vacuum dried.

[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 in accordance with JIS K7122, was 28.6 J / g. The weight-average molecular weight of the maleic anhydride-modified propylene / 1-butene copolymer, measured by GPC, was 100,000. In the maleic anhydride-modified propylene / 1-butene copolymer, the modification amount (introduction amount) of the monomer in the propylene / 1-butene copolymer was 0.8 mass%.

[0195] <Production of amorphous hydrocarbon polymer> Manufacturing Example 2 In a continuous polymerization reactor equipped with a stirrer and thoroughly purged with nitrogen, 1 liter of dehydrated and purified hexane was added, and ethylaluminum sesquichloride (Al(C2H5)1.5 Cl) adjusted to 96 mmol / L was added. 1.5 A hexane solution of VO(OC2H5)C (16 mmol / L) was continuously fed at a rate of 500 ml / h for 1 hour. l2 The hexane solution was continuously fed at 500 ml / hour, and hexane at 500 ml / hour. Meanwhile, the polymerization solution was continuously withdrawn from the top of the polymerization vessel so that the polymerization solution in the vessel was always 1 liter. Next, ethylene gas was fed at 47 L / hour, propylene gas at 47 L / hour, and hydrogen gas at 20 L / hour using a bubbling tube. The copolymerization reaction was carried out at 35°C by circulating a coolant through a jacket attached to the outside of the polymerization vessel. The obtained polymerization solution was deashed with hydrochloric acid, poured into a large amount of methanol for precipitation, and then dried under reduced pressure at 130°C for 24 hours. An ethylene / propylene copolymer was thus produced.

[0196] The ethylene / propylene copolymer had an ethylene content of 55.9 mol%. The ethylene / propylene copolymer had a weight average molecular weight of 14,000. The ethylene / propylene copolymer had a kinematic viscosity at 200°C of 132 cSt, measured in accordance with JIS K 2283.

[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 was added to 400 parts by mass of a mixed solvent of methylcyclohexane / ethyl acetate = 80 / 20, and the mixture was stirred and heated to dissolve at 60°C (dissolution temperature) for 3 hours (dissolution time). This resulted in 500 parts by mass of a resin composition (solid content concentration 20% by mass, 100 parts by mass of crystalline modified olefin polymer and 400 parts by mass of solvent). The acid value of the solid content in the resin composition was 7.77 KOHmg / g. Furthermore, in the crystalline modified olefin polymer, the ring opening rate of the ring structure derived from the acid anhydride group was 78.6%.

[0198] [Preparation of adhesive composition] 500 parts by mass of the resin composition and a crosslinking agent (50 parts by mass of a solution obtained by dissolving 10 parts by mass of jER152 in 40 parts by mass of ethyl acetate) were mixed together to prepare an adhesive composition.

[0199] Example 2 , Example 5 ~ Example 7 and Comparative Example 1 ~ Comparative Example 8 An adhesive composition was prepared according to the same procedure as in Example 1, except that: comparison example 7 , comparison example 8 In Comparative Examples 1 to 3, 5, and 6, in preparing the resin compositions, a crystalline modified olefin polymer, an optional amorphous hydrocarbon polymer, and 320 parts by mass of methylcyclohexane were blended in a flask equipped with a Dean-Stark apparatus and a stirring blade, and stirred under reflux conditions at the dissolution temperature and for the dissolution time shown in Table 1. The mixture was then cooled to 60°C, and 80 parts by mass of ethyl acetate was blended. This prepared the resin compositions.

[0200] Also, Example 2, Example 5 ~ Example 6 and Comparative Examples 3 to 5 , Comparative Example 8 In the preparation of the adhesive composition, 8.0 parts by mass of a solution in which 0.8 parts by mass of DBU was dissolved in 7.2 parts by mass of ethyl acetate was used as a catalyst.

[0201] <Evaluation> [Acid value] A solution was prepared by adding 35 ml of toluene and 15 ml of n-butanol to an Erlenmeyer flask, followed by 0.8 g of a diluted solution prepared by diluting 0.1 g of special-grade bromothymol blue with 100 ml of 19% ethanol. Next, N / KOH-ethanol solution was added to this solution until the solution turned green, and then 5 g of each resin composition from each Example and Comparative Example was added and completely dissolved. The solution was then titrated with N / KOH-ethanol solution until the solution turned blue, the titer was measured, and the acid value was calculated based on the following formula (1). The results are shown in Table 1. Acid number (KOH mg / g) = (sample titration amount × factor × 5.61) / sample weight (1)

[0202] [Ring opening rate] The resin composition of each Example and Comparative Example was applied to a release PET film and dried at 40°C for 30 minutes to produce a coating film with a dry thickness of 50 μm. The infrared absorption spectrum of this coating film was measured by Fourier transform infrared spectroscopy, and the ring-opening ratio was calculated based on the following formula (2). The results are shown in Table 1. Ring opening rate (%)=D1715cm -1 / (D1715cm -1 +D1780cm -1 ) (2) D1715cm -1 : Absorbance of the ring-opened acid anhydride group D1780cm -1 :Absorbance of acid anhydride group

[0203] [Adhesion during low-temperature lamination] The adhesive composition of each Example and Comparative Example was applied to the other thickness-wise surface of the aluminum foil and dried at 120°C for 30 seconds (dry film thickness: approximately 3 μm). As a result, a first adhesive layer was disposed (formed) on the other thickness-wise surface of the aluminum foil. Next, a 40 μm-thick CPP film (one-sided corona-treated) was disposed on the other thickness-wise surface of the first adhesive layer (the other thickness-wise surface of the first adhesive layer and the corona-treated surface of the CPP film were bonded on a hot plate at 60°C). This was then aged at 60°C for 3 days. A laminate was thus produced.

[0204] The resulting laminate was cut into a 15 mm wide test piece, and a 180° peel test was performed on this test piece using a universal tensile tester at a crosshead speed of 50 mm / min in an atmosphere of 23°C to measure the peel strength of the aluminum foil / CPP. The results are shown in Table 1. The adhesion in an atmosphere of 23°C was also evaluated based on the following criteria. The results are shown in Table 1. (standard) ⊚: The peel strength of aluminum foil / CPP was 11 N / 15 mm or more. Good: The peel strength of aluminum foil / CPP was 8 N / 15 mm or more and less than 11 N / 15 mm. ×: The peel strength of aluminum foil / CPP was less than 8 N / 15 mm.

[0205] [Heat resistance] The test pieces were subjected to a 180° peel test at a crosshead speed of 50 mm / min using a universal tensile tester in a 120°C atmosphere to measure the heat resistance strength of the AL / CPP. The adhesion in a 120°C atmosphere was evaluated based on the following criteria. The results are shown in Table 1. (standard) ⊚: The peel strength of aluminum foil / CPP was 3N / 15mm or more. Good: The peel strength of aluminum foil / CPP was 1 N / 15 mm or more and less than 3 N / 15 mm. ×: The peel strength of aluminum foil / CPP was less than 1 N / 15 mm.

[0206] [Pot life] The adhesive composition of each Example and Comparative Example was placed in a 50 cc vial and immersed in a water bath at 25° C. The viscosity was measured 30 minutes and 24 hours after immersion, and the viscosity increase rate was calculated based on the following formula (3). Viscosity increase rate (%) = Viscosity after 24 hours of immersion / Viscosity after 30 minutes of immersion × 100 (3)

[0207] The pot life was also evaluated based on the following criteria, and the results are shown in Table 1. (standard) ⊚: The viscosity increase rate was 110% or less. ◯: The viscosity increase rate was more than 110% and less than 200%. ×: Gelled.

[0208] <Consideration> Example 1 in which the ring opening rate is 50% or more and 90% or less , Example 2, Example 5 ~ Example 7, Comparative Examples 7 and 8 It can be seen that the adhesive strength and usable time are excellent when laminating at low temperatures.

[0209] On the other hand, Comparative Examples 1 to 3, in which the ring opening rate is less than 50%, are excellent in pot life and heat resistance, but show reduced adhesion during low-temperature lamination.

[0210] Also, Example 1 using a crosslinking agent containing an epoxy compound and / or an oxazoline compound , Example 2, Example 5 ~ Example 7, Comparative Examples 7 and 8 It is clear that it has excellent heat resistance.

[0211] On the other hand, it is clear that Comparative Examples 4 to 6, which use an isocyanate compound as the crosslinking agent, have reduced heat resistance.

[0212] Furthermore, according to Comparative Examples 5 and 6, even if the ring-opening rate is less than 50%, if an isocyanate compound is used as a crosslinking agent, the adhesion during low-temperature lamination can be improved, but the usable time is reduced.

[0213] In contrast, Example 1 , Example 2, Example 5 ~ Example 7, Comparative Examples 7 and 8 It can be seen that the use of a crosslinking agent with lower reactivity than an isocyanate compound (a crosslinking agent containing an epoxy compound and / or an oxazoline compound) can improve the pot life, and that increasing the ring-opening rate (50% to 90%) can improve adhesion during low-temperature lamination. It can also be seen that the use of the above crosslinking agent can improve heat resistance.

[0214] From the above, it can be seen that if the ring opening rate is 50% or more and 90% or less and the crosslinking agent contains an epoxy compound and / or an oxazoline compound, the adhesion during low-temperature lamination, the usable time, and the heat resistance can be improved.

[0215] [Table 1] [Explanation of symbols]

[0216] 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. a crystalline modified olefin polymer; a cross-linking agent; the crystalline modified olefin polymer is obtained by modifying a crystalline α-olefin polymer having 2 to 20 carbon atoms with a monomer having an acid anhydride group, In the crystalline modified olefin polymer, a ring-opening rate of the ring structure derived from the acid anhydride group is 70% or more and 90% or less, The adhesive composition, wherein the crosslinking agent comprises an epoxy compound and / or an oxazoline compound.

2. 2. The adhesive composition according to claim 1, further comprising a non-crystalline hydrocarbon polymer having a kinematic viscosity at 200[deg.] C. of 1 cSt or more and 100,000 cSt or less.

3. 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. The adhesive composition of claim 1 further comprising a catalyst.

5. A laminate comprising, in order toward one side in a thickness direction, a first adhesive layer made of a dried product of the adhesive composition according to any one of claims 1 to 4 and a substrate.

6. A packaging material comprising an inner layer and the laminate according to claim 5 in this order toward one side in the thickness direction.

7. A packaging material for a battery case, comprising the packaging material according to claim 6, a second adhesive layer, and an outer layer, arranged in this order toward one side in a thickness direction.

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