Composition, method for producing same, laminate, and exterior container

Abstract

The present invention relates to a composition comprising: component (A), which is a modified propylene-based block copolymer obtained by modifying a propylene-based block copolymer, having, as constituents, component (a1) which is a propylene homopolymer or a copolymer of propylene containing 90 mass% or more and less than 100 mass% of a propylene monomer and another C2-8 α-olefin, and component (a2) which is a copolymer of propylene containing 60 mass% or more and less than 90 mass% of a propylene monomer and another C2-8 α-olefin; and component (B) which is an unmodified propylene-based polymer having a melting point of 120°C or higher.

Description

Composition and method for producing the same, laminate and outer container

[0001] The present invention relates to a composition and a method for producing the same. The present invention also relates to a laminate and an outer container having an adhesive layer made of the composition.

[0002] Lithium-ion secondary batteries have been widely used as driving sources for various electronic devices such as office automation devices such as laptop computers, smartphones, game devices, and electronic organizers, as on-board power sources for hybrid vehicles or electric vehicles, and in stationary power storage systems.

[0003] Conventionally, metal cans formed by pressing metal into cylindrical or rectangular parallelepiped cases have been used as exterior containers for lithium-ion secondary batteries. However, in recent years, in response to the demand for greater freedom in product shape, laminate exterior containers, which are bag- or tray-shaped laminates made of metal foil and resin, have been used instead of the metal cans.

[0004] More specifically, the laminate outer container is a laminate comprising a heat-resistant polymer layer as a protective layer, a metal foil as a base layer, and a heat-sealable polymer layer as an innermost layer and a sealing layer. To house the battery body inside, the laminate is drawn to form a recess, and the battery body is filled into the recess, followed by heat sealing to hermetically seal the contents.

[0005] In addition to the above, a configuration is known in which an adhesive layer is further provided between the metal foil and the heat-sealable polymer layer to increase the adhesive strength. For this adhesive layer, for example, a propylene-based polymer, such as modified polypropylene obtained by modifying polypropylene with an unsaturated carboxylic acid or a derivative thereof, has been actively investigated.

[0006] For example, Patent Document 1 discloses an adhesive resin composition containing a polymer composition consisting of a modified crystalline olefin polymer (A) containing an unsaturated carboxylic acid or its anhydride and an unmodified crystalline olefin polymer (B). Patent Document 2 discloses a composite having a composition layer (I) formed from a specific propylene copolymer, an ethylene-α-olefin copolymer, and a modified polyolefin, and a metal layer (II).

[0007] Japanese Patent Publication No. 59-138252 Japanese Patent Publication No. 2020-93428

[0008] On the other hand, in the case of an outer container of a lithium ion secondary battery, hermetic sealing is very important from the viewpoint of safety, and therefore, the composition containing a propylene-based polymer used in the adhesive layer is also required to have better adhesiveness.

[0009] Furthermore, the performance of lithium-ion secondary batteries is primarily evaluated by their volumetric energy density and gravimetric energy density. Therefore, as lithium-ion secondary batteries become thinner and lighter, the corners of laminated outer containers must have sharper shapes to maximize battery capacity within a limited installation space. Attempting to achieve such shapes increases the likelihood of breakage or peeling, resulting in insufficient strength and even the risk of fire.

[0010] Therefore, the adhesive layer and heat-sealable polymer layer of the laminate need to have mechanical properties that can withstand stretching and bending during drawing of the laminate, i.e., high whitening resistance. In contrast, the polymer composition disclosed in Patent Document 1 leaves room for improvement in adhesion to metal. Also, the composite disclosed in Patent Document 2 leaves room for improvement in adhesion to metal and whitening resistance during secondary processing.

[0011] Therefore, an object of the present invention is to provide a composition that, when used in an adhesive layer, has excellent adhesion to metals and improved resistance to whitening during secondary processing, and a method for producing the same, as well as to provide a laminate and an outer container having an adhesive layer made of the composition.

[0012] The present inventors have conducted extensive research to solve the above-mentioned problems and have found that the above-mentioned problems can be solved by preparing a composition containing two components: a modified propylene-based block copolymer obtained by modifying a specific propylene-based block copolymer, and an unmodified propylene-based polymer having a melting point within a specific range, thereby completing the present invention.

[0013] That is, the gist of the present invention is as follows: [1] A composition comprising component (A) and component (B), wherein component (A) is a modified propylene-based block copolymer obtained by modifying a propylene-based block copolymer having components (a1) and (a2) as constituents with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof, component (a1) is a propylene homopolymer or a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is 90% by mass or more and less than 100% by mass, component (a2) is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is 60% by mass or more and less than 90% by mass, and component (B) is an unmodified propylene-based polymer having a melting point of 120°C or more. [2] The composition according to [1] above, wherein the component (B) is a propylene-based block copolymer having the component (a1) and the component (a2)' as constituent components, and the component (a2)' is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is 10% by mass or more but less than 90% by mass. [3] The composition according to [2] above, wherein the component (B) is a propylene-based block copolymer having no branched structure or having short chain branches in the molecular chain. [4] The composition according to [2] or [3] above, wherein the content of the component (a1) in the component (B) is 30% by mass or more and 80% by mass or less, and the content of the component (a2)' in the component (B) is 20% by mass or more and 70% by mass or less. [5] The composition according to any one of [1] to [4] above, wherein the modification rate of the component (A) is 0.1% by mass or more and 5.0% by mass or less. [6] The composition according to any one of [1] to [5], wherein the content of the component (a1) relative to the total content of the component (a1) and the component (a2) in the component (A) is 30 mass% or more and 80 mass% or less. [7] The composition according to any one of [1] to [6], wherein the flexural modulus of the component (A) measured in accordance with ISO 178:2019 is 100 MPa or more and 700 MPa or less.[8] The composition according to any one of [1] to [7] above, wherein the component (A) has a haze of 90 or less at a thickness of 1 mm as measured in accordance with ISO 14782:2021. [9] The composition according to any one of [1] to [8] above, wherein the component (B) has a flexural modulus of 100 MPa or more and 1,300 MPa or less as measured in accordance with ISO 178:2019.

[10] The composition according to any one of [1] to [9] above, wherein the component (B) has a haze of 90 or less at a thickness of 1 mm as measured in accordance with ISO 14782:2021.

[11] The composition according to any one of [1] to

[10] above, wherein the content of the component (A) with respect to the total of the components (A) and (B) is 3% by mass or more and 60% by mass or less.

[12] The composition according to any one of [1] to

[11] above, further comprising an olefin-based elastomer as component (C), wherein the olefin-based elastomer has a melting point of less than 100°C or has no melting point.

[13] The composition according to

[12] above, wherein the content of component (C) is 5 parts by mass or more and 33 parts by mass or less per 100 parts by mass of the total of component (A) and component (B).

[14] The composition according to

[12] or

[13] above, further comprising an olefin-based polymer having a long-chain branched structure in the molecule as component (D).

[15] The composition according to

[14] above, wherein the olefin-based polymer of component (D) includes a low-density polyethylene having a melting point of 100°C or more.

[16] The composition according to

[14] or

[15] , wherein the content of the component (C) is 5 parts by mass or more and 33 parts by mass or less, and the content of the component (D) is 5 parts by mass or more and 33 parts by mass or less, relative to 100 parts by mass of the total of the component (A) and the component (B).

[0014]

[17] A laminate having a base layer, an adhesive layer made of the composition according to any one of [1] to

[16] above, and a seal layer.

[18] The laminate according to

[17] above, in which the base layer, the adhesive layer, and the seal layer are laminated in this order.

[19] The laminate according to

[17] or

[18] above, in which the base layer is made of a metal foil, a vapor-deposited film, or a resin film having barrier properties.

[20] The laminate according to

[19] above, in which the base layer is made of a metal foil, and the metal foil is an aluminum alloy foil or a stainless steel foil.

[21] The laminate according to any one of

[17] to

[20] above, in which the seal layer contains a propylene-based polymer.

[0015]

[22] An outer container having a base material layer, an adhesive layer made of the composition according to any one of [1] to

[16] above, and a seal layer.

[23] The outer container according to

[22] above, in which the base material layer, the adhesive layer, and the seal layer are laminated in this order.

[24] The outer container according to

[22] or

[23] above, in which the base material layer is made of a metal foil, a vapor-deposited film, or a resin film having barrier properties.

[25] The outer container according to

[24] above, in which the base material layer is made of a metal foil, and the metal foil is an aluminum alloy foil or a stainless steel foil.

[26] The outer container according to any one of

[22] to

[25] above, which is an outer container for a battery.

[0016]

[27] A method for producing a composition, comprising: a step of starting to produce component (a2) after starting to produce component (a1), thereby obtaining a propylene-based block copolymer; a step of reacting the obtained propylene-based block copolymer with at least one compound selected from the group consisting of unsaturated carboxylic acids and derivatives thereof in the presence of a radical generator, thereby obtaining a modified propylene-based block copolymer; and a step of melt-kneading the obtained modified propylene-based block copolymer with a propylene-based polymer having a melting point of 120°C or higher, thereby obtaining a composition, wherein component (a1) is a propylene homopolymer or a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is from 90% to less than 100% by mass, and wherein component (a2) is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is from 60% to less than 90% by mass.

[0017] According to the present invention, a composition can be obtained that, when used in an adhesive layer, exhibits excellent adhesion to metals and has improved resistance to whitening during secondary processing. It is also possible to realize a laminate and an outer container having an adhesive layer made of the composition. Even when the outer container is made into a laminate outer container for a thin, lightweight lithium-ion secondary battery or the like, it can be suitably subjected to drawing processes such as stretching and bending that have sharp corners or are deep, without whitening, while maintaining good adhesion.

[0018] <Composition> The composition according to this embodiment contains component (A) and component (B). Component (A) is a modified propylene-based block copolymer obtained by modifying a propylene-based block copolymer having components (a1) and (a2) as constituent components with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof. Here, component (a1) is a propylene homopolymer or a copolymer of propylene having a propylene monomer content of 90% by mass or more but less than 100% by mass and another α-olefin having 2 to 8 carbon atoms. Component (a2) is a copolymer of propylene having a propylene monomer content of 60% by mass or more but less than 90% by mass and another α-olefin having 2 to 8 carbon atoms. Component (B) is an unmodified propylene-based polymer having a melting point of 120°C or higher. In this specification, "mass%" and "wt%" and "parts by mass" have the same meaning.

[0019] Furthermore, the component (A) in this embodiment can also be said to be a modified propylene-based block copolymer obtained by modifying a propylene-based block copolymer obtained by starting to produce the component (a2) by polymerization after starting to produce the component (a1) by polymerization with at least one compound selected from the group consisting of unsaturated carboxylic acids and derivatives thereof.

[0020] <Mechanism> Component (A) in the composition according to this embodiment is a component that contributes to the adhesion to the substrate layer, which is the adherend, when the composition is used in an adhesive layer. Component (a1) constituting component (A) has a higher crystallinity than component (a2), which increases the cohesive force when cooled and solidified, improves the material strength, and contributes to solvent resistance and heat resistance. On the other hand, component (a2) constituting component (A) has a lower crystallinity than component (a1), which improves the wettability, i.e., adhesion, to the substrate layer, which is the adherend.

[0021] The component (A) is a modified propylene-based block copolymer modified with at least one selected from the group consisting of unsaturated carboxylic acids and their derivatives. The modification results in grafting of the unsaturated carboxylic acid or its derivative onto the propylene-based block copolymer, resulting in improved adhesiveness.

[0022] In contrast to the above, in the composition according to the present embodiment, the component (B) which is an unmodified propylene polymer has flexibility and excellent rigidity and resistance to whitening when stretched. In addition, since the component (B) has a melting point of 120°C or higher, it also imparts good heat resistance.

[0023] The composition according to the present embodiment may further contain a specific olefin-based elastomer as an optional component (C). Component (C) improves wettability to the adherend and also has the effect of alleviating the stress caused by shrinkage during solidification after melt molding, thereby contributing to improved adhesion.

[0024] The composition according to the present embodiment may further include a specific olefin polymer as an optional component (D). Component (D) has a long-chain branched structure in the molecular chain, high melt elasticity, and improved moldability. When the composition according to the present embodiment further includes component (D), component (a2) and component (C), which are components of component (A), have the effect of compatibilizing component (D) in components (A) and (B), thereby improving moldability while maintaining whitening resistance and adhesiveness. Furthermore, when component (B) includes component (a2)', which differs from component (a2) in that the propylene monomer content is 10% by mass or more but less than 90% by mass, as described below, component (a2)' also has the effect of compatibilizing component (A) and component (B), thereby improving moldability while maintaining whitening resistance and adhesiveness.

[0025] <Component (A)> Component (A) in this embodiment is a modified propylene-based block copolymer obtained by starting to produce component (a2) after starting to produce component (a1) by polymerization, wherein the propylene-based block copolymer is modified with at least one selected from the group consisting of unsaturated carboxylic acids and their derivatives. That is, component (A) is a modified propylene-based block copolymer obtained by modifying a propylene-based block copolymer having components (a1) and (a2) as constituents with at least one selected from the group consisting of unsaturated carboxylic acids and their derivatives.

[0026] In this specification, "unsaturated carboxylic acid and its derivative" may be referred to as "modifier." Furthermore, modification with the modifier results in grafting of the unsaturated carboxylic acid or its derivative to the propylene-based block copolymer. Here, "grafting" refers to bonding of the unsaturated carboxylic acid or its derivative to the propylene-based block copolymer. The bonding position of the unsaturated carboxylic acid or its derivative in the modified propylene-based block copolymer is not particularly limited, as long as it is introduced into at least one of the main chain terminal and side chain of the propylene-based block copolymer. In this specification, "propylene-based block copolymer" refers to a sequential polymer (block copolymer) containing propylene units as constituent units, and the content (mass %) of propylene units is the highest among all constituent units.

[0027] Component (a1) In this embodiment, component (a1) is a propylene homopolymer or a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, in which the propylene monomer content is 90% by mass or more but less than 100% by mass. That is, component (a1) is a crystalline propylene polymer in which the propylene monomer content is 90% by mass or more and 100% by mass or less, based on a total of 100% by mass of propylene monomer units and other α-olefin monomer units having 2 to 8 carbon atoms other than propylene. In the specification, the content of each monomer in the copolymer is determined by nuclear magnetic resonance spectroscopy or infrared spectroscopy.

[0028] The other α-olefins having 2 to 8 carbon atoms are α-olefins other than propylene, that is, α-olefins having 2, 4 to 8 carbon atoms. In addition to ethylene, examples of the other α-olefins include 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Of the above, the copolymer may consist of only one kind, or two or more kinds may be combined.

[0029] The component (a1) is preferably a homopolymer of propylene or a copolymer consisting of only propylene and ethylene, and more preferably a homopolymer of propylene.

[0030] The content of propylene monomer units in the entire polymer of component (a1) is 90% by mass or more and 100% by mass or less, but from the viewpoints of improving material strength (cohesive strength), and hence adhesive strength, solvent resistance, and heat resistance, it is preferably 90% by mass or more, more preferably 94% by mass or more, and even more preferably 99% by mass or more. There is no particular upper limit to the content, and 100% by mass, i.e., a propylene homopolymer, is more preferred, as described above.

[0031] When component (a1) is a propylene homopolymer, any of the commonly known propylene homopolymers having an atactic, isotactic, syndiotactic, etc., structure can be used. Of these, an isotactic structure is particularly preferred from the viewpoint of heat resistance.

[0032] Component (a2) In this embodiment, the component (a2) is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, in which the propylene monomer content is 60% by mass or more and less than 90% by mass, based on 100% by mass of the total of propylene monomer units and other α-olefin monomer units having 2 to 8 carbon atoms other than propylene.

[0033] The other α-olefin is an α-olefin other than propylene, i.e., an α-olefin having 2 or 4 to 8 carbon atoms, and examples thereof include the same α-olefins as those exemplified for component (a1). The other α-olefin may consist of only one type, or two or more types may be combined. Of these, component (a2) is preferably a copolymer consisting of only propylene and ethylene.

[0034] In the present embodiment, the component (a2) has a propylene monomer unit content of 60% by mass or more but less than 90% by mass. From the viewpoints of mechanical strength and handleability when the composition is used as an adhesive layer, the content is 60% by mass or more, preferably 63% by mass or more, and more preferably 65% ​​by mass or more. Furthermore, from the viewpoints of improving adhesive strength due to wettability at the adhesive interface and whitening resistance due to strain relaxation that occurs after high-temperature shaping, the content is preferably less than 90% by mass, more preferably less than 89% by mass, and even more preferably less than 86% by mass.

[0035] In the modified propylene-based block copolymer (A) of this embodiment, the content of the (a1) component relative to the total content of the (a1) component and the (a2) component is preferably 30% by mass or more and 80% by mass or less. From the viewpoints of material strength, heat resistance, and solvent resistance, the content is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, even more preferably 45% by mass or more, and is preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less.

[0036] On the other hand, the content of the (a2) component relative to the total content of the (a1) component and the (a2) component is preferably 20% by mass or more and 70% by mass or less. Here, from the viewpoints of improving adhesive strength due to wettability at the adhesive interface, and whitening resistance and transparency due to strain relaxation that occurs after high-temperature shaping, the content is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, still more preferably 35% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, and still more preferably 55% by mass or less.

[0037] Propylene-Based Block Copolymer The propylene-based block copolymer of this embodiment contains the components (a1) and (a2) as constituent components. Therefore, the propylene-based block copolymer is a copolymer of propylene and an α-olefin other than propylene having 2 to 8 carbon atoms, with propylene being the essential component.

[0038] More specifically, it is believed that the propylene-based block copolymer of this embodiment does not have a uniform α-olefin concentration, but has a distribution in copolymer composition. That is, the propylene-based block copolymer has a sea-island structure in which propylene-rich (co)polymer regions form the sea and α-olefin-rich copolymer regions form the islands, and an α-olefin-poor phase is formed at the boundary between the sea and the islands. Here, the islands can be, for example, several μm or less in size. These factors are believed to enable the present embodiment to achieve extremely excellent adhesion and good blushing resistance. In this specification, the term "(co)polymer" refers to at least one of a polymer and a copolymer.

[0039] The size of the islands is preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less. The lower limit is not particularly limited, but is, for example, 0.01 μm or more. The size of the islands can be measured using a transmission electron microscope (TEM).

[0040] The above-described sea-island structure can be achieved even when the components (a1) and (a2) are not sequentially polymerized, for example, by melt-dispersing the components (a1) and (a2) and applying shear force to uniformly disperse them, and the size of the islands can also be reduced. However, such a method fails to form an α-olefin-poor phase at the boundary between the sea and the islands, and fails to form a copolymer composition having a non-uniform distribution of the α-olefin concentration. As a result, the excellent blushing resistance of this embodiment cannot be achieved.

[0041] The composition according to this embodiment is characterized by the fact that, by adopting the above-described configuration, excellent whitening resistance can be achieved in both the MD and TD directions when extrusion-molded. For example, when the whitening resistance (%) is defined as the elongation until whitening, as described below, the whitening resistance in at least one of the MD and TD directions is preferably greater than 450%, more preferably 480% or more, and more preferably 500% or more. It is even more preferable that the whitening resistance in both the MD and TD directions be within the above-described ranges.

[0042] The propylene-based block copolymer may be obtained by any production method as long as it satisfies the above-mentioned conditions.

[0043] The catalyst used in the sequential polymerization of the components (a1) and (a2) is not particularly limited, but is preferably, for example, a catalyst comprising an organoaluminum compound and a solid component essentially containing a titanium atom, a magnesium atom, a halogen atom, and an electron donor compound.

[0044] The organoaluminum compound is a compound represented by the general formula R １ ｍ AlX （３－ｍ） In the above general formula, R １ represents a hydrocarbon residue having 1 to 12 carbon atoms, X represents a halogen atom, and m is an integer of 1 to 3. Examples of such organoaluminum compounds include trialkylaluminums such as trimethylaluminum and triethylaluminum; dialkylaluminum halides such as dimethylaluminum chloride and diethylaluminum chloride; alkylaluminum sesquihalides such as methylaluminum sesquichloride and ethylaluminum sesquichloride; alkylaluminum dihalides such as methylaluminum dichloride and ethylaluminum dichloride; and alkylaluminum hydrides such as diethylaluminum hydride.

[0045] Among the solid components essentially containing titanium atoms, magnesium atoms, halogen atoms, and an electron donor compound, the titanium compound serving as a titanium atom supply source is a compound represented by the general formula Ti(OR ２ )（４－ｎ） X ｎ In the above general formula, R ２ represents a hydrocarbon residue having 1 to 10 carbon atoms, X represents a halogen atom, and n is an integer of 0 to 4. Preferred examples of such titanium compounds include titanium tetrachloride, tetraethoxytitanium, and tetrabutoxytitanium.

[0046] Among the solid components, examples of magnesium compounds that serve as a supply source of magnesium atoms include dialkyl magnesium, magnesium dihalides, dialkoxy magnesium, and alkoxy magnesium halides, with magnesium dihalides being preferred among them.

[0047] Among the solid components, halogen atoms include fluorine, chlorine, bromine, and iodine, with chlorine being preferred. Halogen atoms are usually supplied from the titanium compound or magnesium compound described above, but may also be supplied from other halogen sources such as aluminum halides, silicon halides, and tungsten halides.

[0048] Among the solid components, examples of the electron donor compound include oxygen-containing compounds such as alcohols, phenols, ketones, aldehydes, carboxylic acids, organic or inorganic acids and derivatives thereof, and nitrogen-containing compounds such as ammonia, amines, nitriles, and isocyanates. Among these, inorganic acid esters, organic acid esters, and organic acid halides are preferred, with silicate esters, phthalate esters, cellosolve acetate esters, and phthalic acid halides being more preferred.

[0049] The silicate ester may be a compound represented by the general formula R ３ R ４ （３－ｐ） Si(OR ５ ) ｐ In the above general formula, R ３ R represents a branched aliphatic hydrocarbon residue having 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms, or a cyclic aliphatic hydrocarbon residue having 5 to 20 carbon atoms, preferably 6 to 10 carbon atoms. ４represents a branched or straight-chain aliphatic hydrocarbon residue having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. ５ represents an aliphatic hydrocarbon residue having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms; and p is an integer of 1 to 3.

[0050] Particularly preferred examples of the organosilicon compound include t-butyl-methyl-dimethoxysilane, t-butyl-methyl-diethoxysilane, cyclohexyl-methyl-dimethoxysilane, and cyclohexyl-methyl-diethoxysilane.

[0051] In the present embodiment, the sequential polymerization for producing the propylene-based block copolymer before modification of component (A) is carried out, for example, in a first step by supplying propylene alone or propylene and an α-olefin other than propylene having 2 to 8 carbon atoms and polymerizing the copolymer to produce component (a1). Here, the polymerization is carried out, for example, in the presence of the above-mentioned catalyst at a temperature of 50 to 150°C, preferably 50 to 100°C, and a propylene partial pressure of 0.5 to 4.5 MPa, preferably 1.0 to 3.5 MPa, to polymerize or copolymerize propylene as the main component and, if necessary, the above-mentioned α-olefin other than propylene (hereinafter, collectively sometimes referred to as "(co)polymerization").

[0052] Subsequently, in the second stage, propylene and another α-olefin other than propylene having 2 to 8 carbon atoms are supplied and polymerized to produce component (a2). Here, the polymerization is carried out, for example, in the presence of the above-mentioned catalyst under conditions of a temperature of 50 to 150°C, preferably 50 to 100°C, and a partial pressure of 0.3 to 4.5 MPa, preferably 0.5 to 3.5 MPa for each of propylene and the other α-olefin other than propylene (propylene-α-olefin copolymerization).

[0053] For example, the propylene-based block copolymer in this embodiment can be obtained by initiating the production of component (a2) after starting the production of component (a1) by polymerization. Here, the production of component (a2) may be initiated after the production of component (a1) by polymerization is completed. However, from the viewpoint of suitably obtaining a copolymer composition having an α-olefin concentration distribution that is not uniform, it is preferable to start the production of component (a2) before the production of component (a1) is completed so that there is time for both components (a1) and (a2) to be produced. In other words, it is preferable to allow time for the first stage and the second stage to proceed together.

[0054] The (co)polymerization of component (a1) and component (a2) may be carried out batchwise, continuously, or semi-batchwise. The first stage (co)polymerization of component (a1) is preferably carried out in a gas phase or liquid phase. The second and subsequent stages of copolymerization of component (a2) are preferably carried out in a gas phase or liquid phase, more preferably in a gas phase. The residence time in each stage is preferably 0.5 to 10 hours, more preferably 1 to 5 hours.

[0055] The contents of the (a1) and (a2) components in the resulting propylene-based block copolymer can be adjusted by the amount of monomers (co)polymerized in each stage. The isotactic index of the (a1) component can be adjusted by the type of catalyst used, polymerization conditions, etc. Examples of polymerization conditions include temperature, pressure, and the composition of the charged monomers.

[0056] The propylene-based block copolymer used in this embodiment may be a prepared one or a commercially available product. Specifically, commercially available products may be appropriately selected from "Newcon (registered trademark) and Wellnex (registered trademark)" manufactured by Japan Polypropylene Corporation, "Tefabloc (registered trademark)" manufactured by Mitsubishi Chemical Corporation, and "Adflex (registered trademark), Adcyl (registered trademark), and Softel (registered trademark)" manufactured by Lyondell Basell, Inc., to obtain the desired properties.

[0057] In the present embodiment, only one type of propylene-based block copolymer may be used, or two or more types having different monomer compositions, physical properties, etc. may be mixed and used.

[0058] The propylene-based block copolymer of the present embodiment may have a propylene component or an α-olefin component derived from biomass. "Biomass-derived" means that the propylene-based block copolymer is obtained by chemical or biological synthesis using renewable biomass resources as raw materials. The biomass-derived propylene-based block copolymer has the characteristic that, even when incinerated, it does not increase the carbon dioxide concentration in the atmosphere due to the carbon-neutrality of biomass.

[0059] The biomass-derived propylene-based block copolymer is preferably one made from plant-derived propylene obtained from a plant raw material and an α-olefin other than propylene.

[0060] Plant-derived propylene block copolymers and petroleum-derived propylene block copolymers are generally classified into two groups based on their biomass content (the ratio of sample carbon to standard modern carbon). １４ Specifically, plant-derived １４ C (radioactive carbon 14, half-life 5730 years), whereas petroleum-derived materials contain this radiocarbon ( １４ Therefore, the propylene-based block copolymer １４ By measuring the C concentration by accelerator mass spectrometry, plant-derived and petroleum-derived components can be distinguished. Furthermore, the biomass degree can also be used as an index of the content of plant-derived components in a polymer composition containing a plant-derived polymer and a petroleum-derived polymer. The above-mentioned methods of distinction and measurement of the biomass degree also apply to modified propylene-based block copolymers obtained by modifying the propylene-based block copolymer.

[0061] The biomass ratio can be measured, for example, by the following method. The sample to be measured is burned to generate carbon dioxide, which is then purified in a vacuum line and reduced with hydrogen using iron as a catalyst to generate graphite. This graphite is then analyzed using a tandem accelerator-based １４ Attach it to a C-AMS dedicated device (NEC) １４ Counting C, １３ The concentration of C ( １３ C / １２ C), １４ The concentration of C ( １４ C / １２ C) is measured, and the carbon content of the sample is compared to that of the standard modern carbon. １４ The C concentration ratio is calculated.

[0062] The propylene-based block copolymer may be a so-called mass balance type obtained from biomass naphtha. Biomass naphtha is preferable from the viewpoint of environmental protection because it is obtained by decomposing and refining animal fats, waste cooking oils, vegetable oil processing waste and residues, vegetable oils, etc., which have traditionally been discarded.

[0063] From the viewpoint of environmental protection, the propylene-based block copolymer may be made from recycled raw materials, and the recycling method may be material recycling or chemical recycling.

[0064] Material recycling refers to the process of crushing, dissolving, and otherwise treating waste plastics, and then reusing them as raw materials for similar applications. Specifically, this refers to post-consumer recycling (PCR), which collects used products from the market and turns them into recycled resources, and post-industrial recycling (PIR), which recycles and reuses materials generated in the manufacturing process of products before they are released to the market. Chemical recycling is a system in which waste plastics are chemically decomposed to return them to their raw material state and reuse them as product raw materials. Chemical recycling is preferable from the perspective of suppressing deterioration in physical properties.

[0065] The flexural modulus (ISO 178:2019) of the propylene-based block copolymer in this embodiment is preferably 100 MPa or more and 700 MPa or less. From the viewpoint of maintaining cohesive strength and enhancing adhesiveness, the flexural modulus is preferably 100 MPa or more, more preferably 200 MPa or more, and even more preferably 300 MPa or more. On the other hand, from the viewpoint of improving the wettability of the adhesive interface, alleviating strain due to expansion and contraction during melt-stretching and cooling and solidification, and maintaining adhesiveness, the flexural modulus is preferably 700 MPa or less, more preferably 650 MPa or less, and even more preferably 600 MPa or less.

[0066] The haze (ISO 14782:2021, thickness 1 mm) of the propylene-based block copolymer in this embodiment is preferably 2 or more and 90 or less. From the viewpoint of high whitening resistance and solvent resistance, the haze is preferably 90 or less, more preferably 80 or less, and even more preferably 70 or less. The lower limit of the haze is not particularly limited, but from the viewpoint of adhesiveness, it is preferably 2 or more, more preferably 10 or more, and even more preferably 20 or more.

[0067] The density of the propylene-based block copolymer in this embodiment (JIS K7112: 1999) is not particularly limited, but is, for example, 0.85 to 0.94 g / cm ３ Here, from the viewpoint of maintaining cohesive force and enhancing adhesiveness, the density is preferably 0.85 g / cm ３ More than 0.87 g / cm ３ More preferably, 0.89 g / cm ３ On the other hand, from the viewpoint of improving the wettability of the adhesive interface and enhancing the adhesiveness, the density is 0.94 g / cm ３ Preferably, 0.92 g / cm or less ３ More preferably, 0.90 g / cm ３ The following is even more preferred:

[0068] The melt flow rate (MFR, JIS K7210:2014, temperature 230°C, load 2.16 kg, 2 mm orifice diameter) of the propylene-based block copolymer in this embodiment is not particularly limited, but is preferably, for example, 0.05 g / 10 min or more and 200 g / 10 min or less. Here, from the viewpoint of ensuring sufficient wettability of the modified propylene-based block copolymer obtained by modification, improving adhesiveness, and reducing the extrusion and stirring load during the reaction, the MFR is preferably 0.05 g / 10 min or more, more preferably 0.1 g / 10 min or more, even more preferably 0.5 g / 10 min or more, particularly preferably 1.0 g / 10 min or more, and particularly preferably 1.5 g / 10 min or more. On the other hand, from the viewpoint of increasing the molecular weight and thus the cohesive strength and ensuring the adhesive strength, the MFR is preferably 200 g / 10 min or less, more preferably 100 g / 10 min or less, even more preferably 50 g / 10 min or less, particularly preferably 10 g / 10 min or less, and particularly preferably 3 g / 10 min or less. In addition, by making the MFR equal to or less than the upper limit, it is possible to prevent the thickness of the adhesive layer from becoming thin during heat sealing when the composition according to this embodiment is used in the adhesive layer, thereby preventing an electrical short circuit, and furthermore, it is preferable to obtain the desired seal strength and electrolyte resistance.

[0069] The melting point of the propylene-based block copolymer in this embodiment is not particularly limited, but is preferably, for example, 120 to 170°C. From the viewpoint of heat resistance, the melting point is preferably 120°C or higher, and more preferably 130°C or higher. From the viewpoint of adhesiveness, the melting point is preferably 170°C or lower, and more preferably 165°C or lower. The melting point in this specification refers to the temperature at the top of the endothermic peak measured by a differential scanning calorimeter (DSC).

[0070] Modification Component (A) in this embodiment is a modified propylene-based block copolymer obtained by modifying the above-mentioned propylene-based block copolymer with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof.

[0071] The unsaturated carboxylic acid and its derivative used for modification are not particularly limited, and examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, etc. Furthermore, the derivative of the unsaturated carboxylic acid is not particularly limited, and examples of the derivative include acid anhydrides, esters, amides, imides, and metal salts. Specific examples of the derivatives of unsaturated carboxylic acids include maleic anhydride, himic anhydride, itaconic anhydride, citraconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, glycidyl acrylate, maleic acid monoethyl ester, maleic acid diethyl ester, itaconic acid monomethyl ester, itaconic acid diethyl ester, acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethylamide, maleic acid-N,N-diethylamide, maleic acid-N-monobutylamide, maleic acid-N,N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monobutylamide, fumaric acid-N,N-dibutylamide, maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate, sodium methacrylate, potassium acrylate, and potassium methacrylate.

[0072] The unsaturated carboxylic acids and their derivatives may be used singly or in any combination and ratio of two or more. Among these, maleic acid and its anhydride are particularly preferred because of their low electron density and high reactivity, with maleic anhydride being the most preferred.

[0073] The graft modification to obtain the modified propylene-based block copolymer, component (A) in this embodiment, may be performed by any known method. For example, the modification may be performed by a thermal reaction alone, or by adding a known organic peroxide or the like that generates radicals during the reaction as a radical generator. Examples of the modification method include a solution modification method in which the reaction is performed in a solvent, and a melt modification method that does not use a solvent. Furthermore, other methods such as a suspension dispersion reaction method may also be used.

[0074] The melt modification method includes a method in which a propylene-based block copolymer, an unsaturated carboxylic acid and its derivative, and, if necessary, a radical generator described below are mixed in advance and then melt-kneaded in a kneader to cause a reaction. Alternatively, a method in which a mixture of a radical generator and an unsaturated carboxylic acid and its derivative is added to a propylene-based block copolymer melted in a kneader through a charging port to cause a reaction may be used.

[0075] For mixing, a Henschel mixer, ribbon blender, V-type blender, etc. can be usually used. For melt kneading, a single-screw or twin-screw extruder, roll, Banbury mixer, kneader, Brabender mixer, etc. can be usually used.

[0076] The solution modification method includes a method in which a propylene-based block copolymer is dissolved in an organic solvent or the like, and a radical generator and an unsaturated carboxylic acid and its derivative, which will be described later, are added thereto to effect graft copolymerization.

[0077] The organic solvent is not particularly limited, but examples thereof include alkyl-substituted aromatic hydrocarbons, halogenated hydrocarbons, etc. For efficient graft modification, it is preferable to carry out the modification in the presence of a radical initiator.

[0078] The radical initiator is not particularly limited, but is preferably an organic peroxide or an azo compound, and more preferably an organic peroxide. The radical initiator may be used alone or in any combination and ratio of two or more kinds.

[0079] Specific examples of radical initiators include di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, 1,4-bis(t-butylperoxyisopropyl)benzene, 1,1-bis(t-butylperoxy)cyclohexane, and n-butyl-4,4-bis(t-butylperoxy)valerate. dialkyl peroxides such as 2,2-bis(4,4-t-butylperoxycyclohexyl)propane, 2,2-bis(t-butylperoxy)butane, or 1,1-bis(t-butylperoxy)cyclododecane; t-butylperoxyacetate, t-butylperoxy-2-ethylhexanoate, t-butylperoxypivalate, t-butylperoxylaurate, t-butylperoxybenzoate, t-butylperoxyisopropylcaprylate, peroxyesters such as dicarbonate, t-butylperoxymaleic acid, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)hexyne-3, and 2,5-dimethyl-2,5-di(toluylperoxy)hexane; diacyl peroxides such as di-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, and dibenzoyl peroxide; hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, and 2,5-dimethyl-2,5-di(hydroperoxy)hexane; or ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, but are not particularly limited to these.

[0080] Among these, radical initiators having a decomposition temperature of 100°C or higher, at which the half-life is 1 minute, are preferred from the viewpoint of graft modification efficiency. Specifically, dialkyl peroxides such as di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, and peroxyesters such as t-butyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, and 2,5-dimethyl-2,5-di(benzoylperoxy)hexyne-3 are preferred.

[0081] The amount of the radical initiator used is not particularly limited, but is preferably 0.001 to 10 parts by mass per 100 parts by mass of the propylene-based block copolymer.

[0082] After the propylene-based block copolymer has been modified as described above, it may be subjected to a treatment to remove unreacted unsaturated carboxylic acid and its derivative components. The treatment method is not particularly limited, but an example thereof includes a method in which the modified propylene-based block copolymer after the modification reaction is placed in a storage tank having a structure that allows gas to be blown in from the bottom of the apparatus, the apparatus is heated to about 100°C with a heater or thermal oil, and an inert gas such as nitrogen or air is blown in from the bottom of the apparatus for treatment for 6 to 24 hours.

[0083] Component (A) In the present embodiment, the component (A) is a modified propylene-based block copolymer obtained by modifying the propylene-based block copolymer with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof, as described above.

[0084] The modification rate, which is the proportion of modified components in the modified propylene-based block copolymer that is the component (A), specifically the content of unsaturated carboxylic acid or a derivative thereof grafted onto the propylene-based block copolymer (hereinafter, this may be referred to as the “graft rate”), varies depending on the types of propylene-based block copolymer and modifier, and is not particularly limited.

[0085] In this embodiment, the modification rate of component (A) is preferably 0.1% by mass or more and 5.0% by mass or less. From the viewpoint of improving adhesiveness, the modification rate (graft rate) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.3% by mass or more, particularly preferably 0.5% by mass or more, and particularly preferably 0.8% by mass or more. On the other hand, from the viewpoint of preventing crosslinking of the propylene-based block copolymer and suppressing deterioration of melt moldability and gel generation, the modification rate is preferably 5.0% by mass or less, more preferably 4.5% by mass or less, even more preferably 4.0% by mass or less, particularly preferably 3.5% by mass or less, and particularly preferably 3.0% by mass or less.

[0086] The modification rate (graft rate) of component (A) refers to the content of unsaturated carboxylic acid or its derivative component when the modifier component (unsaturated carboxylic acid or its derivative) in the modified propylene-based block copolymer, which is component (A), is quantitatively determined in advance using a standard sample by nuclear magnetic resonance (NMR) measurement, and a calibration curve created from the quantitative values ​​is used to measure the content of unsaturated carboxylic acid or its derivative component with an infrared spectrometer. For example, pellets made of the modified propylene-based block copolymer are heat-pressed into a sheet having a thickness of about 100 μm, and the specific absorption of the unsaturated carboxylic acid or its derivative in the sample is measured. Specifically, the specific absorption is a peak at 1900 to 1600 cm －１ (C═O stretching vibration band), and the like.

[0087] In the modification with an unsaturated carboxylic acid or a derivative thereof, not all of the added unsaturated carboxylic acid or derivative thereof is subjected to the reaction, and the unsaturated carboxylic acid or derivative thereof that has not reacted with the propylene-based block copolymer may remain in the modified propylene-based block copolymer, which is component (A). However, the modification rate (graft rate) in this specification means the value measured by the above method.

[0088] The flexural modulus (ISO 178:2019) of the modified propylene-based block copolymer, component (A) in this embodiment, is preferably 100 MPa or more and 700 MPa or less. From the viewpoint of maintaining cohesive strength and enhancing adhesiveness, the flexural modulus is preferably 100 MPa or more, more preferably 200 MPa or more, and even more preferably 300 MPa or more. Furthermore, from the viewpoint of improving the wettability of the adhesive interface, alleviating strain due to expansion and contraction during melt-stretching and cooling and solidification, and maintaining adhesiveness, the flexural modulus is preferably 700 MPa or less, more preferably 650 MPa or less, and even more preferably 600 MPa or less.

[0089] The haze (ISO 14782:2021, thickness 1 mm) of the modified propylene-based block copolymer which is component (A) in this embodiment is not particularly limited, but is preferably 90 or less, and more preferably 2 or more and 90 or less. Here, from the viewpoint of high whitening resistance and solvent resistance, the haze is preferably 90 or less, more preferably 80 or less, and even more preferably 70 or less. Furthermore, from the viewpoint of adhesion, the haze is preferably 2 or more, more preferably 10 or more, and even more preferably 20 or more.

[0090] The melt flow rate (MFR; JIS K7210:2014, temperature 180°C, load 2.16 kg, 1 mm orifice diameter) of the modified propylene-based block copolymer, component (A) in this embodiment, is not particularly limited, but is preferably, for example, 0.05 g / 10 min or more and 2000 g / 10 min or less. Here, the MFR is preferably 0.05 g / 10 min or more, more preferably 0.1 g / 10 min or more, and even more preferably 1 g / 10 min or more, from the viewpoint of imparting sufficient fluidity to the modified propylene-based block copolymer and improving wettability, i.e., adhesion, to a substrate layer when the resulting composition is used as an adhesive layer. Furthermore, the MFR is preferably 2000 g / 10 min or less, more preferably 1000 g / 10 min or less, and even more preferably 100 g / 10 min or less, from the viewpoint of dispersibility in a matrix composed of component (B).

[0091] The density (JIS K7112: 1999) of the modified propylene-based block copolymer which is the component (A) in this embodiment is not particularly limited, but is, for example, 0.85 g / cm ３ 0.94g / cm or more ３ From the viewpoint of maintaining cohesive strength and enhancing adhesiveness, the density is preferably 0.85 g / cm or less. ３ More than 0.87 g / cm ３ More preferably, 0.89 g / cm ３ From the viewpoint of improving the wettability of the adhesive interface and enhancing the adhesiveness, the density is more preferably 0.94 g / cm. ３ Preferably, 0.92 g / cm or less ３ More preferably, 0.90 g / cm ３ The following is even more preferred:

[0092] The melting point of the modified propylene-based block copolymer, component (A) in this embodiment, is not particularly limited, but is preferably, for example, 115° C. or higher and 168° C. or lower. From the viewpoint of heat resistance, the melting point is preferably 115° C. or higher, and more preferably 125° C. or higher. From the viewpoint of adhesiveness, the melting point is preferably 168° C. or lower, and more preferably 163° C. or lower.

[0093] <Component (B)> Component (B) in this embodiment is an unmodified propylene polymer having a melting point of 120°C or higher. The unmodified propylene polymer is a component that imparts whitening resistance, rigidity, and heat resistance to the composition according to this embodiment. Furthermore, when the composition is used as an adhesive layer for an outer container of a lithium-ion secondary battery, component (B) acts to improve adhesion.

[0094] The melting point of component (B) may be 120° C. or higher, and preferably 120° C. or higher and 170° C. or lower. From the viewpoint of heat resistance, the melting point is preferably 130° C. or higher, more preferably 140° C. or higher, and even more preferably 150° C. or higher. From the viewpoint of uniform mixing with other components, the melting point is preferably 170° C. or lower, and more preferably 165° C. or lower.

[0095] Component (B) in this embodiment is not particularly limited as long as it satisfies the above conditions. For example, it may be either a propylene homopolymer or a propylene copolymer, with a propylene copolymer being preferred. Examples of propylene copolymers include copolymers of propylene and an α-olefin (sometimes referred to as "propylene-α-olefin copolymers"). Among these, a propylene-α-olefin copolymer is preferred from the viewpoint of a balance between whitening resistance, rigidity, and heat resistance. By using a propylene-α-olefin copolymer, when the composition according to this embodiment is used as an adhesive layer for an outer container of a lithium-ion secondary battery, the mechanical properties and whitening-resistant adhesive strength that can withstand stretching and bending due to drawing can be easily maintained when the composition is processed into the shape of the outer container.

[0096] The α-olefin in the propylene-α-olefin copolymer may, for example, be an α-olefin other than propylene, having 2 to 8 carbon atoms. More specific examples of the propylene-α-olefin copolymer include a propylene-ethylene copolymer, a propylene-butene copolymer, a propylene-hexene copolymer, a propylene-octene copolymer, a propylene-ethylene-hexene copolymer, a propylene-ethylene-octene copolymer, a propylene-butene-hexene copolymer, a propylene-butene-octene copolymer, and a propylene-hexene-octene copolymer.

[0097] The content of the propylene monomer in the unmodified propylene polymer (component (B)) in this embodiment is preferably 51% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, particularly preferably 80% by mass or more, and particularly preferably 90% by mass or more. The upper limit of the content is not particularly limited, and may be 100% by mass or less, for example, less than 100% by mass, 98% by mass or less, or 94% by mass or less.

[0098] Examples of the copolymer include random copolymers and block copolymers. Among them, a propylene-ethylene copolymer is preferred, a propylene-ethylene block copolymer is more preferred, and a propylene-based block copolymer having propylene and ethylene as constituent components is even more preferred.

[0099] From the viewpoint of adhesion to a substrate layer when the composition according to this embodiment is used as an adhesive layer, the propylene-based block copolymer is preferably a propylene-based block copolymer having component (a1) and component (a2)' as constituent components. Here, component (a1) is the same as component (a1) in the aforementioned component (A), and component (a2)' is the same as component (a2) in the aforementioned component (A) except for the content of propylene monomer. That is, component (B) in this embodiment is preferably a propylene-based sequential product obtained by initiating the formation of component (a2)' after initiating the formation of component (a1) by polymerization, similar to the propylene-based block copolymer before modification of component (A).

[0100] As described above, component (a1) is a homopolymer of propylene or a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, in which the propylene monomer content is 90% by mass or more but less than 100% by mass.

[0101] In this embodiment, the component (a1) constituting component (B) is preferably a crystalline propylene polymer having a propylene monomer content of 90% by mass or more and 100% by mass or less, based on a total of 100% by mass of propylene monomer units and other α-olefin monomer units having 2 to 8 carbon atoms other than propylene. Examples of the other α-olefins include, in addition to ethylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene. These may be used alone or in any combination of two or more.

[0102] As the component (a1), a propylene homopolymer consisting of only propylene and a copolymer consisting of only propylene and ethylene are preferred, and a propylene homopolymer consisting of only propylene is more preferred.

[0103] As mentioned above, the content of propylene monomer units in the (a1) component is preferably 90% by mass or more and 100% by mass or less. From the viewpoints of improving material strength (cohesive strength), and hence adhesive strength, solvent resistance, and heat resistance, the content is preferably 90% by mass or more, more preferably 94% by mass or more, and even more preferably 99% by mass or more. The upper limit of the content is not particularly limited, and may be 100% by mass.

[0104] When the component (a1) is a propylene homopolymer, any of the commonly known propylene homopolymers having any structure such as atactic, isotactic, syndiotactic, etc. Among these, an isotactic structure is particularly preferred from the viewpoint of heat resistance.

[0105] The component (a2)' is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, in which the content of propylene monomer is 10% by mass or more but less than 90% by mass.

[0106] In this embodiment, the other α-olefins having 2 to 8 carbon atoms in component (a2)' constituting component (B) include the same α-olefins as those in component (a2) in component (A). As component (a2)', a copolymer consisting of only propylene and ethylene is particularly preferred.

[0107] The content of propylene monomer units in the component (a2)' is 10% by mass or more and less than 90% by mass, and from the viewpoints of the mechanical strength and handleability of the adhesive resin composition, it is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 60% by mass or more, even more preferably 63% by mass or more, and particularly preferably 65% ​​by mass or more. Furthermore, from the viewpoints of improving adhesive strength due to wettability at the adhesive interface and whitening resistance due to strain relaxation occurring after drawing, the content is preferably less than 90% by mass, more preferably less than 89% by mass, and even more preferably less than 86% by mass.

[0108] In component (B), the content of component (a1) is preferably 30% by mass or more and 80% by mass or less, based on the sum of the contents of component (a1) and component (a2)', i.e., the content of component (a2)' is preferably 20% by mass or more and 70% by mass or less. Here, from the viewpoints of material strength, heat resistance, and solvent resistance, the content of component (a1) relative to the total is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 45% by mass or more, even more preferably 55% by mass or more, and preferably 80% by mass or less, more preferably 75% by mass or less, even more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. On the other hand, the content of the (a2)' component relative to the above total is preferably 20% by mass or more, more preferably 25% by mass or more, even more preferably 30% by mass or more, even more preferably 35% by mass or more, and is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 55% by mass or less, and even more preferably 45% by mass or less, from the viewpoints of improving adhesive strength due to wettability at the adhesive interface, and whitening resistance and transparency due to strain relaxation that occurs after high-temperature shaping.

[0109] When component (B) in this embodiment is the unmodified propylene-based block copolymer described above, component (B) is preferably a propylene-based block copolymer that does not have a branched structure or has short-chain branches in the molecular chain. Here, the term "short-chain branched" structure refers to a branched structure in a molecular chain in which the carbon skeleton constituting the branch has six or fewer carbon atoms from the branch point, i.e., a branched structure in a molecular chain in which the main chain of the branch has six or fewer carbon atoms.

[0110] The unmodified propylene polymer as component (B) in this embodiment is not limited to any particular production method as long as it has a melting point of 120° C. or higher. Component (B) can be produced by known methods such as a batch method, a gas phase method, or a slurry method using a catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst.

[0111] The unmodified propylene polymer that is the component (B) in this embodiment may be a prepared product or a commercially available product. Specific examples of commercially available products include "Novatec (registered trademark) PP, Wintec (registered trademark), Newcon (registered trademark), and Wellnex (registered trademark)" manufactured by Japan Polypropylene Corporation, "Tefabloc (registered trademark) and Xelas (registered trademark)" manufactured by Mitsubishi Chemical Corporation, "Prim Polypro (registered trademark)" manufactured by Prime Polymer Co., Ltd., "Tafmer (registered trademark) PN" manufactured by Mitsui Chemicals, Inc., "Sumitomo Noblen (registered trademark)" manufactured by Sumitomo Chemical Co., Ltd., "Polypropylene block copolymer" manufactured by SunAllomer Co., Ltd., "Moplen (registered trademark), Adflex (registered trademark), Adcyl (registered trademark), and Softel (registered trademark)" manufactured by LyondellBasell, "ExxonMobil PP" manufactured by ExxonMobil, and Formosa "Formolene (registered trademark)" manufactured by A. Plastics, "Borealis PP" manufactured by Borealis, "SEETEC PP" manufactured by LG Chemical, and A. A polypropylene having the desired properties can be appropriately selected and used from among "ASI POLYPROPYLENE" manufactured by Schulman, "INEOS PP" manufactured by INEOS Olefins & Polymers, "Braskem PP" manufactured by Braskem, "Samsung Total" manufactured by SAMSUNG TOTAL PETROCHEMICALS, "Sabic (registered trademark) PP" manufactured by Sabic, "TOTAL PETROCHEMICALS Polypropylene" manufactured by TOTAL PETROCHEMICALS, "YUPLENE (registered trademark)" manufactured by SK Corporation, and the like.

[0112] The unmodified propylene polymer serving as component (B) in this embodiment may be one type only, or may contain two or more types differing in monomer composition, physical properties, and the like.

[0113] As for the unmodified propylene-based polymer as component (B) in the present embodiment, similarly to the propylene-based block copolymer before being modified to obtain component (A), from the viewpoint of environmental protection, biomass-derived or recycled materials can be used as the propylene component and the α-olefin component.

[0114] The unmodified propylene polymer as component (B) in this embodiment may consist of one type of (co)polymer or may be a mixture of two or more types of (co)polymers.

[0115] When the unmodified propylene polymer is a copolymer, each copolymer may be any of a block copolymer, a graft copolymer, and a random copolymer.

[0116] The flexural modulus (ISO 178:2019) of the unmodified propylene-based polymer that is component (B) in this embodiment is preferably 100 MPa or more and 1300 MPa or less. From the viewpoint of maintaining cohesive strength and enhancing adhesiveness, the flexural modulus is preferably 100 MPa or more, more preferably 200 MPa or more, even more preferably 300 MPa or more, and particularly preferably 400 MPa or more. On the other hand, from the viewpoint of improving the wettability of the adhesive interface, alleviating strain due to expansion and contraction during drawing and cooling and solidification, and maintaining adhesiveness, the flexural modulus is preferably 1300 MPa or less, more preferably 1050 MPa or less, even more preferably 900 MPa or less, and particularly preferably 700 MPa or less.

[0117] The haze (ISO 14782:2021, thickness 1 mm) of the unmodified propylene polymer which is component (B) in this embodiment is preferably 90 or less, more preferably 2 or more and 90 or less. From the viewpoints of whitening resistance and solvent resistance, the haze is preferably 90 or less, more preferably 80 or less, and even more preferably 70 or less. The lower limit of the haze is not particularly limited, but from the viewpoint of adhesiveness, it is preferably 2 or more, more preferably 10 or more, and even more preferably 20 or more.

[0118] The MFR (JIS K 7210:2014, temperature 230°C, load 2.16 kg, 2 mm orifice diameter) of the unmodified propylene polymer serving as component (B) in this embodiment is not particularly limited, but is preferably, for example, 0.1 g / 10 min or more and 50 g / 10 min or less. From the viewpoints of reducing the energy load during production and the processability of molded articles, the MFR is preferably 0.1 g / 10 min or more, more preferably 0.3 g / 10 min or more, even more preferably 0.5 g / 10 min or more, and particularly preferably 1.0 g / 10 min or more. Furthermore, from the viewpoints of increasing the film thickness retention rate of the adhesive layer after heat sealing and achieving the desired seal strength and electrolyte resistance, the MFR is preferably 50 g / 10 min or less, more preferably 20 g / 10 min or less, even more preferably 10 g / 10 min or less, and particularly preferably 8 g / 10 min or less.

[0119] The density (JIS K7112: 1999) of the unmodified propylene polymer which is the component (B) in this embodiment is not particularly limited, but is, for example, 0.85 to 0.94 g / cm ３ Here, from the viewpoint of maintaining cohesive force and enhancing adhesiveness, the density is preferably 0.85 g / cm ３ More than 0.87 g / cm ３ More preferably, 0.89 g / cm ３ On the other hand, from the viewpoint of improving the wettability of the adhesive interface and enhancing the adhesiveness, the density is 0.94 g / cm ３ Preferably, 0.92 g / cm or less ３ More preferably, 0.90 g / cm ３ The following is even more preferred:

[0120] One aspect of the unmodified propylene polymer that is component (B) in this embodiment is a propylene block copolymer obtained by starting to produce component (a2)' after starting to produce component (a1) by polymerization, and preferably satisfies at least one of the following: a propylene unit content of 51 mass% or more in the propylene polymer, a flexural modulus of 100 MPa or more and 1300 MPa or less, a haze of 90 or less, and an MFR of 0.1 g / 10 min or more and 50 g / 10 min or less, more preferably satisfies at least two of these, and particularly preferably satisfies all of these. When two or more types of components are mixed and used as the unmodified propylene polymer, it is preferable that the mixture satisfies the above aspects.

[0121] <Component (C)> The composition according to the present embodiment preferably further comprises an olefin-based elastomer as component (C), and the olefin-based elastomer is more preferably an olefin-based elastomer having a melting point of less than 100° C. or no melting point, and even more preferably an olefin-based elastomer containing α-olefin units having 2 to 8 carbon atoms as constituent units and having a melting point of less than 100° C. or no melting point. Here, "having no melting point" means having no endothermic peak in DSC measurement.

[0122] The olefinic elastomer, component (C) in this embodiment, is a component for improving the wettability of the adhesive interface and improving adhesive strength. It also functions to relieve strain that occurs at the adhesive interface due to heating and cooling associated with drawing, thereby maintaining adhesive strength. Furthermore, component (C) has the effect of making a specific olefinic polymer, component (D), described below, compatible with components (A) and (B), thereby improving moldability while maintaining blushing resistance and adhesiveness.

[0123] When the olefin-based elastomer, component (C) of this embodiment, contains an α-olefin unit having 2 to 8 carbon atoms as a structural unit, examples of the α-olefin unit include ethylene, propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, and 1-octene. Component (C) is preferably a copolymer containing at least two or more α-olefins selected from the above group. Among these, it is more preferable that the unit having the highest content (mass%) of all structural units is an ethylene unit, a propylene unit, or a 1-butene unit. That is, component (C) is more preferably an ethylene-α-olefin copolymer, a propylene-α-olefin copolymer, or a butene-α-olefin copolymer.

[0124] From the viewpoints of industrial availability, improving compatibility with component (A), component (B), and component (D) described below, suppressing phase separation, and thereby increasing material strength and adhesive strength, component (C) is more preferably an ethylene-propylene copolymer, an ethylene-butene copolymer, an ethylene-octene copolymer, a propylene-ethylene copolymer, or a butene-propylene copolymer, and even more preferably an ethylene-propylene copolymer or a propylene-ethylene copolymer.

[0125] When the olefin-based elastomer that is component (C) in this embodiment is an ethylene-α-olefin copolymer, the content of α-olefin units in the ethylene-α-olefin copolymer is preferably, for example, 3% by mass or more and 49% by mass or less.

[0126] Here, the lower limit of the content is not particularly limited, but is, for example, preferably 3% by mass or more, more preferably 6% by mass or more, even more preferably 9% by mass or more, particularly preferably 12% by mass or more, and particularly preferably 15% by mass or more. By setting the content of the α-olefin unit within the above range, the ethylene-α-olefin copolymer and the composition according to the present embodiment containing the same become flexible, and the wettability of the adhesive interface is improved. As a result, in addition to the adhesive strength at room temperature, distortion that occurs at the adhesive interface due to heating and cooling associated with drawing is alleviated, tending to provide excellent adhesive strength. Furthermore, by including a certain amount of an α-olefin component that is structurally similar to component (A) and component (B) in the ethylene-α-olefin copolymer, compatibility with component (A), component (B), and component (D), described below, is improved, phase separation is suppressed, and material strength and, therefore, adhesive strength tend to be improved.

[0127] On the other hand, the upper limit of the content of α-olefin units in the ethylene-α-olefin copolymer is not particularly limited, but is, for example, preferably 49% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, particularly preferably 37% by mass or less, and particularly preferably 36% by mass or less. By setting the content of α-olefin units within the above range, the crystallinity of the ethylene-α-olefin copolymer can be maintained at a certain level or higher, and the material strength tends to be maintained. As a result, the material strength (cohesive strength) of the composition according to this embodiment is also improved, and sufficient adhesive strength can be achieved.

[0128] When the olefin elastomer which is component (C) in this embodiment is a propylene-α-olefin copolymer, the content of α-olefin units in the propylene-α-olefin copolymer is preferably, for example, from 3% by mass to 45% by mass.

[0129] Here, the lower limit of the content is not particularly limited, but is, for example, preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 7% by mass or more, particularly preferably 9% by mass or more, and particularly preferably 10% by mass or more. By setting the content of the α-olefin unit within the above range, the propylene-α-olefin copolymer and the composition according to the present embodiment containing the same become flexible, improving the wettability of the adhesive interface. As a result, in addition to the adhesive strength at room temperature, the strain generated at the adhesive interface due to heating and cooling associated with drawing tends to be alleviated, and the adhesive strength tends to be excellent. Furthermore, by including a certain amount of an α-olefin component whose structure is similar to component (A) or component (B) in the propylene-α-olefin copolymer, the compatibility with component (A), component (B), and component (D) described below is improved, and phase separation is suppressed, tending to increase the material strength and, in turn, the adhesive strength.

[0130] On the other hand, the upper limit of the content of α-olefin units in the propylene-α-olefin copolymer is not particularly limited, but is, for example, preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 35% by mass or less, particularly preferably 30% by mass or less, and particularly preferably 28% by mass or less. By setting the content of α-olefin units within the above range, the crystallinity of the propylene-α-olefin copolymer can be maintained at a certain level or higher, and the material strength tends to be maintained. As a result, the material strength (cohesive strength) of the composition according to this embodiment is also improved, and sufficient adhesive strength can be achieved.

[0131] The olefin elastomer, component (C) in this embodiment, may contain other monomer units in addition to the above-mentioned α-olefins. Examples of other monomers that can form other monomer units include vinyl acetate, (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, and butyl (meth)acrylate. Here, "(meth)acrylic acid" means at least one of acrylic acid and methacrylic acid.

[0132] The content of α-olefin units and the content of other monomer units in the olefin elastomer, which is component (C) in this embodiment, can each be determined by infrared spectroscopy.

[0133] The melt flow rate (MFR) of the olefin-based elastomer, measured in accordance with JIS K 7210:2014 at 230°C, a load of 2.16 kg, and a 2 mm orifice diameter, is preferably 0.1 g / 10 min or more and 35.0 g / 10 min or less. Here, the MFR is preferably 0.1 g / 10 min or more, more preferably 0.5 g / 10 min or more, and even more preferably 1.0 g / 10 min or more. By setting the MFR within the above range, the composition according to this embodiment tends to have sufficient fluidity and excellent melt moldability. Furthermore, phase separation between component (C) and components (B) and (A) is suppressed, the surface area of ​​the matrix / domain interface is increased, and the material strength (cohesive force) is maintained, resulting in a tendency for excellent adhesive strength.

[0134] On the other hand, the MFR of the olefin-based elastomer is preferably 35.0 g / 10 min or less, more preferably 20.0 g / 10 min or less, and even more preferably 10.0 g / 10 min or less. By setting the MFR within the above range, the material strength (cohesive strength) of the composition according to this embodiment tends to be increased, and thus excellent adhesive strength tends to be easily exhibited. In addition, the film thickness retention rate of the adhesive layer after heat sealing is increased, and desired seal strength and electrolyte resistance can be obtained.

[0135] The density of the olefin-based elastomer (JIS K7112: 1999) is not particularly limited, but is, for example, 0.80 g / cm ３ 0.93g / cm or more ３ From the viewpoint of maintaining cohesive strength and enhancing adhesiveness, the density is preferably 0.80 g / cm or less. ３ More than 0.81 g / cm ３ More preferably, 0.82 g / cm ３ More preferably, 0.83 g / cm ３ More than 0.84 g / cm is particularly preferred. ３ On the other hand, from the viewpoint of improving the wettability of the adhesive interface and enhancing the adhesiveness, the density is 0.93 g / cm ３ Preferably, 0.92 g / cm or less ３ More preferably, 0.91 g / cm or less ３ More preferably, 0.90 g / cm３ The following is particularly preferred: ３ The following are particularly preferred:

[0136] The olefin-based elastomer used as component (C) in this embodiment may be a manufactured product or a commercially available product. Specifically, commercially available products having desired properties may be appropriately selected from the "Tafmer (registered trademark)" series manufactured by Mitsui Chemicals, Inc., the "Karnel (registered trademark)" series manufactured by Japan Polyethylene Corporation, the "Engage (registered trademark) and "Versify (registered trademark)" series manufactured by Dow Chemical Company, the "Solumer (registered trademark)" series manufactured by SK Chemical Company, the "Fortyfy" series manufactured by Sabic Corporation, the "Vistamaxx (registered trademark)" series manufactured by ExxonMobile, the "Lucene (registered trademark)" series manufactured by LG Chemical Company, and the "Wansuper (registered trademark)" series manufactured by Wanhua Chemical Company, etc.

[0137] The olefin-based elastomer as component (C) in this embodiment may be used alone, or may contain two or more types of elastomers differing in monomer composition, physical properties, and the like.

[0138] As the olefin-based elastomer which is component (C) in this embodiment, a biomass-derived or recycled material can be used as the α-olefin component, from the viewpoint of environmental protection, similar to the propylene-based block copolymer before being modified to obtain component (A).

[0139] <Component (D)> In addition to components (A) and (B), the composition according to this embodiment preferably further contains, as component (D), an olefin polymer having a long-chain branched structure in the molecule, and more preferably also contains component (C). This can impart excellent neck-in properties to the composition according to this embodiment. In other words, component (D) is a good molding processing aid.

[0140] Here, the "long chain branched structure" in component (D) refers to a branched structure formed by a molecular chain in which the carbon skeleton constituting the branch has more than six carbon atoms from the branch point, i.e., a branched structure formed by a molecular chain in which the main chain of the branch has more than six carbon atoms. The number of carbon atoms is preferably several tens or more, specifically, preferably 20 or more, and even more preferably 30 or more. The molecular weight of the molecular chain is preferably 85 or more, more preferably several hundred or more, specifically, more preferably 200 or more, and even more preferably 300 or more.

[0141] The branched structure within the molecule of component (D) in this embodiment is not particularly limited as long as it has a structure in which the α-olefin main chain is branched, and branched structures also include those in which the main chain made of α-olefin contains a crosslinked structure. Examples of olefin copolymers having such a branched structure within the molecule include isoprene-grafted polypropylene, polymerization-type long-chain branched polypropylene, and low-density polyethylene. Among these, propylene polymers such as isoprene-grafted polypropylene and polymerization-type long-chain branched polypropylene are preferred from the viewpoints of compatibility with components (A) and (B), i.e., whitening resistance and heat resistance.

[0142] The olefin polymer having a long chain branched structure in the molecule, which is component (D) in this embodiment, may be used alone or in combination of two or more types having different copolymerization component compositions or physical properties.

[0143] The method for producing the olefin polymer having long chain branches in the molecule, which is component (D) in this embodiment, is not particularly limited, and the polymer can be produced by a known method. For example, the olefin polymer having long chain branches can be obtained by modifying the polymer in an extruder in the presence of electron beam irradiation or peroxide and a crosslinking monomer, or by imparting a branched structure during polymerization using a special catalyst.

[0144] When the olefin polymer of component (D) is a propylene polymer such as isoprene-grafted polypropylene or polymerization-type long-chain branched polypropylene, the melting point is not particularly limited, but is preferably, for example, 130° C. or higher and 175° C. or lower. From the viewpoints of heat resistance and film thickness, the melting point is preferably 130° C. or higher, more preferably 140° C. or higher, and even more preferably 150° C. or higher. From the viewpoint of uniform mixing with other components, the melting point is preferably 175° C. or lower.

[0145] When the olefin polymer of component (D) is a propylene polymer such as isoprene-grafted polypropylene or polymerization-type long-chain branched polypropylene, the MFR (JIS K 7210:2014, temperature 230°C, load 2.16 kg, 2 mm orifice diameter) is not particularly limited, but is preferably, for example, 0.5 g / 10 min or more and 70 g / 10 min or less. Here, from the viewpoints of improving the melt elasticity of component (D), increasing the film thickness retention rate when the composition according to the present embodiment is used as an adhesive layer for an outer container of a lithium-ion secondary battery, and suitably obtaining the desired seal strength and electrolyte resistance, the MFR is preferably 70 g / 10 min or less, more preferably 65 g / 10 min or less. Furthermore, from the viewpoints of improving compatibility with other components and achieving excellent uniform mixing with other components, the MFR is preferably 0.5 g / 10 min or more.

[0146] When the olefin polymer of component (D) is a propylene polymer such as isoprene-grafted polypropylene or polymerization-type long-chain branched polypropylene, the density (JIS K7112: 1999) is not particularly limited, but for example, it is 0.880 g / cm ３ 0.910g / cm or more ３ Here, from the viewpoint of suppressing a decrease in adhesiveness to a substrate layer at high temperatures, i.e., heat resistance, when the composition according to this embodiment is used as an adhesive layer, the density is set to 0.880 g / cm ３ The upper limit of the density is not particularly limited, but is usually 0.910 g / cm ３ The following is the result.

[0147] The olefin polymer having a long chain branched structure in the molecule, which is component (D) in this embodiment, may be a manufactured product or a commercially available product. Specific examples of commercially available products include "Daploy (registered trademark) WB135HMS" manufactured by Borealis, "WAYMAX (registered trademark) MFX3, MFX8, EX4000" manufactured by Japan Polypropylene Corporation, "SLB039N (registered trademark)" manufactured by Kaneka Corporation, and "Profax (registered trademark) PF-814" manufactured by Basel, and can be appropriately selected from these to provide the desired properties.

[0148] As the olefin polymer having long chain branches in the molecule, which is component (D) in this embodiment, a low-density polyethylene can also be used, and a low-density polyethylene having a melting point of 100° C. or higher is more preferred. As component (D), a propylene polymer having long chain branches in the molecule and the above-mentioned low-density polyethylene may be used in combination, and these may be appropriately selected and used in combination depending on the desired properties such as adhesiveness and processability.

[0149] The density of the low-density polyethylene (JIS K7112: 1999) is 0.860 g / cm ３ 0.930g / cm or more ３ Preferably, the density is 0.860 g / cm or less. ３ More preferably, 0.910 g / cm ３ More preferably, 0.930 g / cm ３ The following is preferred: The low-density polyethylene is preferably a high-pressure low-density polyethylene that has an excellent balance between adhesiveness and strength, and it is more preferred that the density of the high-pressure low-density polyethylene is within the above range.

[0150] When component (D) in this embodiment is a low-density polyethylene, its physical properties are not particularly limited, but for example, the MFR (JIS K 7210:2014, temperature 190°C, load 2.16 kg, 2 mm orifice diameter) may be 1 g / 10 min or more and 30 g / 10 min or less. Here, from the viewpoint of high-speed moldability associated with improved dispersibility in the composition, the MFR may be 1 g / 10 min or more, and preferably 3 g / 10 min or more. Furthermore, from the viewpoint of high-speed moldability associated with improved processability, the MFR may be 30 g / 10 min or less, preferably 20 g / 10 min or less, and more preferably 15 g / 10 min or less.

[0151] The low-density polyethylene used as component (D) in this embodiment may be a manufactured product or a commercially available product. Specific examples of commercially available products include the "Novatec (registered trademark)" series manufactured by Japan Polyethylene Corporation, the "Ultzex ​​(registered trademark) and Evolue (registered trademark)" series manufactured by Prime Polymer Co., Ltd., the "Eltex (registered trademark)" series by Ineos, and the "SABIC (registered trademark) LDPE" series manufactured by Sabic.

[0152] <Content ratio> Content ratio of component (A) and component (B) In the composition according to this embodiment, the content ratio of component (A) is preferably 3% by mass or more and 60% by mass or less, where the total of component (A) and component (B) is 100% by mass. Here, from the viewpoint of adhesiveness, the content ratio is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and particularly preferably 15% by mass or more. Furthermore, from the viewpoint of the mechanical strength of the composition according to this embodiment, the content ratio is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 45% by mass or less, even more preferably 40% by mass or less, and particularly preferably 30% by mass or less.

[0153] On the other hand, the content of component (B) in the total of 100% by mass of the components (A) and (B) is preferably 40% by mass or more and 97% by mass or less. Here, from the viewpoint of mechanical strength and solvent resistance, the content is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 55% by mass or more, even more preferably 60% by mass or more, and particularly preferably 70% by mass or more. Also, from the viewpoint of adhesiveness, the content is preferably 97% by mass or less, more preferably 95% by mass or less, even more preferably 90% by mass or less, and even more preferably 85% by mass or less.

[0154] - Content of component (C) relative to the total of components (A) and (B) When the composition according to this embodiment further contains component (C), the content of component (C) relative to 100 parts by mass of the total of components (A) and (B) may be 100 parts by mass or less, or may be 5 parts by mass or more and 100 parts by mass or less, and preferably 5 parts by mass or more and 33 parts by mass or less. Here, from the viewpoint of improving the fluidity of the composition according to this embodiment, making it easier to apply, and improving the wettability with the substrate layer when used as an adhesive layer, thereby improving the adhesion to the substrate layer, the content is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more. The upper limit of the content is not particularly limited and may be, for example, 100 parts by mass or less. However, from the viewpoint of suppressing a decrease in cohesive force, maintaining high mechanical strength, and suppressing unexpected adhesion between pellets or sheets of the composition according to this embodiment, the content is preferably 33 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 25 parts by mass or less.

[0155] Content of component (D) relative to components (A) and (B): When the composition according to the present embodiment further contains component (D), the content of component (D) relative to 100 parts by mass of the total of components (A) and (B) is preferably 5 parts by mass or more and 33 parts by mass or less. From the viewpoints of extrusion processability and neck-in flowability, the content is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more. Furthermore, from the viewpoints of suppressing a decrease in cohesive force, maintaining high mechanical strength, and adhesiveness, the content is preferably 33 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 25 parts by mass or less.

[0156] Furthermore, when the composition according to the present embodiment contains both component (C) and component (D), it is more preferable that the content of component (C) is 5 parts by mass or more and 100 parts by mass or less, and the content of component (D) is 5 parts by mass or more and 33 parts by mass or less, relative to 100 parts by mass of the total of component (A) and component (B).

[0157] - Content (modification rate) of unsaturated carboxylic acid and its derivative in the composition In the composition according to this embodiment, the content of unsaturated carboxylic acid and its derivative component relative to the total 100% by mass of component (A), component (B), optional component (C), and optional component (D) is preferably 0.025% by mass or more, more preferably 0.025% by mass or more and 2.0% by mass or less. Here, from the viewpoint of adhesive strength to a substrate layer when the composition according to this embodiment is used as an adhesive layer, the content is preferably 0.025% by mass or more, more preferably 0.05% by mass or more. Furthermore, from the viewpoint of suppressing a decrease in compatibility due to increased ease of aggregation, the content is preferably 2.0% by mass or less, more preferably 1.0% by mass or less.

[0158] The content of the unsaturated carboxylic acid and its derivative components can be calculated from the modification rate (graft rate) of the modified propylene-based block copolymer of component (A) and the content of component (A) in the composition.

[0159] <Other Components> In addition to the above-described component (A), component (B), optional component (C), and optional component (D), the composition according to the present embodiment may further contain other components such as additives, tackifiers, resins, etc., as long as the effects of the present invention are not significantly impaired. Only one type of other component may be used, or two or more types may be used in any combination and ratio.

[0160] As the other components, additives that can be blended into the composition according to the present embodiment are not particularly limited, and examples thereof include heat stabilizers, weather stabilizers (antioxidants, light stabilizers, ultraviolet absorbers, etc.), flame retardants, foaming agents, antiblocking agents, slip agents, antistatic agents, fillers (inorganic and / or organic fillers, etc.), processing aids, plasticizers, crystal nucleating agents, impact improvers, compatibilizers, neutralizers for catalyst residues, carbon black, colorants (pigments, dyes, etc.), and the like.

[0161] When an additive is used, the content of each additive is not particularly limited, but may be, for example, 0.01% by mass or more and 5% by mass or less relative to the composition according to the present embodiment. Here, the content may be 0.01% by mass or more, 0.2% by mass or more, 5% by mass or less, or 2% by mass or less.

[0162] As the other component, a tackifier that can be blended in the composition according to the present embodiment includes, for example, an amorphous resin that is solid at room temperature. More specifically, examples of the amorphous resin that is solid at room temperature include petroleum resin, rosin resin, terpene resin, and hydrogenated products thereof.

[0163] On the other hand, if a large amount of tackifier is contained in the composition according to this embodiment, smoke may be generated during molding or heat resistance may be reduced. Therefore, when a tackifier is used, the total content of the tackifier in the composition according to this embodiment is preferably 30% by mass or less, and more preferably 20% by mass or less.

[0164] The composition according to the present embodiment has excellent low-temperature processability even without a tackifier, and when used as an adhesive layer, exhibits good adhesion to a substrate layer. Furthermore, the composition can maintain good adhesion to a substrate layer even under high-temperature and high-humidity environments.

[0165] Examples of petroleum resins that can be used as tackifiers include aliphatic petroleum resins, aromatic petroleum resins, copolymers thereof, and hydrogenated products thereof. Examples of the petroleum resin skeleton include C5 resins, C9 resins, C5 / C9 copolymer resins, cyclopentadiene resins, polymers of vinyl-substituted aromatic compounds, copolymers of olefins / vinyl-substituted aromatic compounds, copolymers of cyclopentadiene compounds / vinyl-substituted aromatic compounds, and hydrogenated products thereof.

[0166] Examples of rosin resins that can be used as tackifiers include natural resins containing abietic acid as a main component, such as natural rosin, polymerized rosin derived from natural rosin, stabilized rosin obtained by disproportionating or hydrogenating natural rosin or polymerized rosin, unsaturated acid-modified rosin obtained by adding unsaturated carboxylic acids to natural rosin or polymerized rosin, natural rosin ester, modified rosin ester, and polymerized rosin ester.

[0167] Examples of terpene resins that can be used as tackifiers include polyterpene resins, aromatic terpene resins such as terpene phenol resins, aromatic modified terpene resins, and hydrogenated products thereof.

[0168] As the other components, resins that can be blended into the composition according to the present embodiment are not particularly limited, and examples thereof include polyphenylene ether resins, polycarbonate resins, polyamide resins such as nylon 66 and nylon 11, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, styrene resins such as polystyrene, cyclic polyolefin resins, and acrylic / methacrylic resins such as polymethyl methacrylate resins.

[0169] However, in order to effectively obtain the effects of the present invention due to the composition according to the present embodiment containing the above-mentioned component (A), component (B), optional component (C), and optional component (D), the content of resins other than components (A) to (D) relative to 100% by mass of all resin components in the composition according to the present embodiment is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and particularly preferably 10% by mass or less.

[0170] <<Method for Producing the Composition>> The composition according to this embodiment can be obtained by mixing the above-described components in a predetermined ratio. The method for obtaining component (A) has been described above. One embodiment of a method for producing a composition containing components (A) and (B) includes the following steps: (a) starting the production of component (a2) after starting the production of component (a1), thereby obtaining a propylene-based block copolymer; (b) reacting the obtained propylene-based block copolymer with at least one member selected from the group consisting of unsaturated carboxylic acids and their derivatives in the presence of a radical generator to obtain a modified propylene-based block copolymer; and (c) melt-kneading the obtained modified propylene-based block copolymer with a propylene-based polymer having a melting point of 120°C or higher to obtain a composition. Here, as described above, component (a1) is a propylene homopolymer or a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, in which the propylene monomer content is 90% by mass or more but less than 100% by mass. The component (a2) is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, in which the content of propylene monomer is 60% by mass or more but less than 90% by mass. The method for obtaining a propylene-based polymer having a melting point of 120°C or more may include a step of starting to produce the component (a2)' after starting to produce the component (a1), thereby obtaining a propylene-based block copolymer.

[0171] In addition, when the resulting composition further contains component (C), component (D) and other components in addition to component (A) and component (B), these components may be further mixed.

[0172] The mixing method is not particularly limited as long as the components are uniformly dispersed. That is, the above-mentioned components can be mixed simultaneously or in any order to obtain a composition in which the components are uniformly dispersed.

[0173] In order to mix and disperse the components more uniformly, it is preferable to melt-mix predetermined amounts of the components. For example, the components in this embodiment may be mixed in any order and then heated, or all of the components may be mixed while being melted sequentially. Alternatively, the mixture of the components may be pelletized, or melt-mixed during molding to produce the desired molded product.

[0174] The composition according to the present embodiment can also be prepared by mixing predetermined amounts of the above components by various known methods, followed by melt-kneading, granulation, or pulverization. For example, a tumbler blender, V-blender, ribbon blender, Henschel mixer, or the like can be used for the mixing.

[0175] For the melt-kneading after mixing, for example, a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader, etc. The temperature during melt-kneading may be any temperature at which at least one of the components is in a molten state, but it is preferable to select a temperature at which all of the components used are melted, and for example, the melt-kneading is generally carried out in the range of 150 to 300°C.

[0176] The composition according to the present embodiment does not need to be used as an independent raw material as long as it contains at least the above-described components (A) and (B). That is, a resin composition that already contains two or more of these components may be used as a raw material, or a molded article made of the resin composition may be crushed and used as a raw material. In addition, if a raw material that is already a resin composition does not contain all of the components that constitute the composition according to the present embodiment, only the missing components may be supplemented as raw materials.

[0177] <<Molded Article>> The molded article obtained from the composition according to this embodiment is not particularly limited, and can be various extrusion molded articles or injection molded articles. In addition, since the composition according to this embodiment has excellent adhesion to various metals and resins described below, it is suitable for use as an adhesive layer of a laminate using these as a substrate. However, this does not exclude the use of the composition according to this embodiment alone to form a molded article such as a single-layer sheet.

[0178] The laminate according to the present embodiment includes an adhesive layer made of the composition according to the present embodiment described above, and a sealing layer, and the sealing layer can be provided on one or both sides of the adhesive layer so as to be in contact with the adhesive layer. The sealing layer is preferably a layer made of a resin.

[0179] The laminate according to this embodiment preferably further comprises a substrate layer in addition to the adhesive layer and the sealing layer. The substrate layer is preferably a layer having barrier properties, and more preferably is made of a metal and / or resin having barrier properties. That is, one aspect of the laminate according to this embodiment comprises a substrate layer, the adhesive layer, and the sealing layer.

[0180] Furthermore, the laminate according to this embodiment is preferably a laminate having three or more layers stacked together, and among these, a laminate having a base layer, an adhesive layer made of the composition according to this embodiment, and a seal layer stacked together in this order is more preferred.

[0181] Examples of the laminate according to this embodiment include a laminate sheet, a laminate film, a laminate tube, etc. Here, the terms "sheet" and "film" both mean planar molded articles and are synonymous.

[0182] The resin constituting the seal layer in this embodiment is not particularly limited, and examples thereof include the resins listed as the above-mentioned components (A), (B), (C), and (D), as well as the resins listed as other components. Among these, from the viewpoint of excellent co-extrudability with the composition in this embodiment, it is preferable to contain an olefin-based polymer, and from the viewpoints of adhesion to the adhesive layer, heat resistance, and heat sealability, it is more preferable to contain a propylene-based polymer.

[0183] The thickness of the sealing layer in this embodiment may be adjusted, for example, depending on the thickness of the adhesive layer. The thickness of the sealing layer is not particularly limited, but is preferably in the range of 5 to 100 μm, and more preferably in the range of 20 to 80 μm. Furthermore, from the viewpoint of thinning, the thickness of the sealing layer may be 30 μm or less. Even with such a thin film configuration, the laminate according to this embodiment can have high drawing processability and heat sealability.

[0184] The material constituting the base layer of the laminate according to this embodiment is not particularly limited, but examples thereof include metal foil, a vapor deposition film, a resin film, etc. The base layer has a barrier property that prevents moisture, oxygen, light, etc. from penetrating into the interior. That is, the base layer in this embodiment is preferably made of a metal foil, a vapor deposition film, or a resin film that has a barrier property.

[0185] Examples of vapor-deposited films having barrier properties that constitute the substrate layer in this embodiment include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Examples of resin films having barrier properties that constitute the substrate layer in this embodiment include polyvinylidene chloride, fluorine-containing resins such as chlorotrifluoroethylene and tetrafluoroethylene, and ethylene-vinyl alcohol copolymers. Examples of metal foils having barrier properties that constitute the substrate layer in this embodiment include aluminum alloy foils, stainless steel foils, titanium steel foils, and steel sheet foils. Among these, aluminum alloy foils and stainless steel foils are preferred from the viewpoint of water vapor barrier properties.

[0186] As the aluminum alloy foil to be used as the metal foil, a soft aluminum alloy foil that has been annealed is preferred from the viewpoint of imparting desired ductility during forming. Furthermore, an aluminum alloy foil containing iron is more preferred from the viewpoint of imparting further pinhole resistance and ductility during forming.

[0187] The iron content in the aluminum alloy foil is preferably 0.1 to 9.0 mass% based on 100 mass% of the aluminum alloy foil. From the viewpoint of achieving better pinhole resistance and ductility, the iron content is preferably 0.1 mass% or more, more preferably 0.5 mass% or more. From the viewpoint of flexibility, the iron content is preferably 9.0 mass% or less, more preferably 2.0 mass% or less.

[0188] In addition, the aluminum alloy foil is preferably chemically treated on at least one side, more preferably both sides, for stabilizing adhesion and preventing dissolution and corrosion. The chemical treatment is a treatment for forming an acid-resistant coating on the surface of the aluminum alloy foil. When an acid-resistant coating is formed on the surface of the aluminum alloy foil, the acid-resistant coating is included in the aluminum alloy foil.

[0189] Examples of the chemical conversion treatment include chromate treatment using a chromium compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromate acetylacetate, chromium chloride, or potassium chromium sulfate; phosphate treatment using a phosphate compound such as sodium phosphate, potassium phosphate, ammonium phosphate, or polyphosphoric acid; and chemical conversion treatment using an aminated phenol polymer. Among chromium compounds, chemical conversion treatment using a chromic acid compound is preferred.

[0190] In the present embodiment, the substrate layer may be a laminate of two or more types. In addition, the layer configuration of the adhesive layer made of the composition and the substrate layer in the present embodiment is not limited, but it is preferable that these layers are adjacent to each other.

[0191] The form of the substrate layer in this embodiment is not limited to a film or a sheet, and may be a woven fabric, nonwoven fabric, etc. The substrate layer may have a single-layer structure or a multi-layer structure.

[0192] The method for producing the substrate layer having a multilayer structure is not particularly limited, but examples thereof include a co-extrusion film method, a dry lamination method, a wet lamination method, a hot melt lamination method, an extrusion lamination method, and a thermal lamination method.

[0193] The thickness of the base layer in this embodiment is not particularly limited, but is preferably, for example, 9 to 200 μm. From the viewpoints of barrier properties, pinhole resistance, processability, etc., the thickness is preferably 9 μm or more, more preferably 15 μm or more, and is preferably 200 μm or less, more preferably 100 μm or less.

[0194] In the laminate according to this embodiment, the thickness of the adhesive layer made of the composition according to this embodiment is not particularly limited and can be set as desired depending on the layer configuration, application, shape of the final product, required physical properties, etc. The thickness may be, for example, 0.1 to 1000 μm. Here, the thickness is preferably 0.1 μm or more, more preferably 0.3 μm or more, and even more preferably 0.5 μm or more, and is preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 200 μm or less.

[0195] In addition to the adhesive layer, the substrate layer, and the seal layer made of the composition of the present embodiment, the laminate according to the present embodiment may be provided with an optional layer as needed to provide insulation, moldability, designability, and electrolyte resistance. The optional layer may be provided, for example, on the surface of the adhesive layer opposite to the substrate layer made of metal foil or the like.

[0196] Examples of the optional layer include resin films of polyester resin, polyamide resin, epoxy resin, acrylic resin, fluororesin, polyurethane resin, silicone resin, phenolic resin, and mixtures or copolymers thereof. Among these, resin films of polyester resin and polyamide resin are preferred, and resin films of biaxially oriented polyester resin and biaxially oriented polyamide resin are more preferred.

[0197] Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, copolymer polyester, polycarbonate, etc. Specific examples of the polyamide resin include nylon 6, nylon 66, a copolymer of nylon 6 and nylon 66, nylon 6,10, polyamide MXD6 (polymetaxylylene adipamide), etc.

[0198] Any layer in this embodiment may be formed from a single layer of resin film, but from the viewpoint of pinhole resistance and insulation properties, it may have a multilayer structure formed from two or more layers of resin film.

[0199] Specific examples of the multilayer structure include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which multiple nylon films are laminated, and a multilayer structure in which multiple polyester films are laminated. More specifically, a multilayer structure in which a biaxially oriented nylon film and a biaxially oriented polyester film are laminated, a multilayer structure in which multiple biaxially oriented nylon films are laminated, and a multilayer structure in which multiple biaxially oriented polyester films are laminated are preferred. For example, a multilayer structure in which a polyester resin and a polyester resin are laminated, a multilayer structure in which a polyamide resin and a polyamide resin are laminated, or a multilayer structure in which a polyester resin and a polyamide resin are laminated are preferred, and a multilayer structure in which polyethylene terephthalate and polyethylene terephthalate are laminated, a multilayer structure in which nylon and nylon are laminated, or a multilayer structure in which polyethylene terephthalate and nylon are laminated are more preferred.

[0200] Furthermore, when the laminate according to the present embodiment is used in, for example, a lithium ion secondary battery, the polyester resin is unlikely to discolor even when an electrolytic solution adheres to the surface. Therefore, in the multilayer structure, it is preferable to laminate the polyester resin so that it is located in the outermost layer.

[0201] In this embodiment, when a multilayer structure is formed by providing any layer, the thickness of each layer is preferably about 2 to 25 μm.

[0202] The laminate according to this embodiment can be produced by various known methods, of which lamination molding (lamination processing) is preferred.

[0203] The lamination process includes an extrusion lamination method in which a molten resin film extruded from a T-die is continuously coated and pressure-bonded onto the surface of a pre-fabricated substrate layer, and a thermal lamination method in which a film previously formed and solidified by a T-die is thermally pressure-bonded. Usually, the substrate layer is laminated on one surface, but it may be laminated on both surfaces if necessary.

[0204] In the lamination molding, not only one type of substrate layer is used as a film in advance, but also two or more types of films may be used. In this case, they may be molded by simultaneous lamination, or one substrate layer may be used in advance to form a laminate, and then the other substrate layer may be laminated to this. In addition, only one type of resin may be used for lamination, or two or more types may be co-extruded.

[0205] The laminate according to the present embodiment may be formed into a stretched film by stretching the laminate after lamination by the above-described method, etc. In such a case, it is preferable to use a non-stretched resin film or sheet as the base layer.

[0206] Various known methods can be used to produce a stretched film. The stretching direction may be uniaxial or biaxial. The stretched film may be produced by sequential stretching or simultaneous stretching. Furthermore, as one of the stretching methods, an inflation film may be produced by inflation molding at the stage of producing a laminate.

[0207] When the laminate according to this embodiment is obtained by stretching, after stretching as described above, heat setting may be carried out, or the product may be produced without heat setting.

[0208] The laminate thus produced may be subjected to various film processing treatments such as metal deposition, corona discharge treatment, printing, etc., if desired.

[0209] The composition of this embodiment exhibits excellent adhesion to metals, resins, etc., as well as excellent whitening resistance, solvent resistance, and heat resistance. Therefore, the laminate of this embodiment using the composition as an adhesive layer can be suitably used in body materials, frame materials, cylindrical body materials, packaging materials, etc. in transportation equipment such as automobiles and aircraft, home appliances, electronics, and robotics. In particular, in the transportation equipment, home appliance, and electronics fields, the laminate can be suitably used as outer containers for power storage systems and secondary batteries, especially lithium-ion batteries.

[0210] The outer container according to the present embodiment includes a substrate layer, an adhesive layer made of the composition according to the present embodiment, and a seal layer. Here, the substrate layer, adhesive layer, and seal layer, as well as any other layers, may be the same as the substrate layer, adhesive layer, and seal layer, as well as any other layers in the laminate according to the present embodiment described above, and preferred embodiments are also the same.

[0211] In particular, the outer container according to this embodiment is suitable as an outer container for a battery, as described above, and the outer container for a battery according to this embodiment can be used as a packaging material for hermetically storing battery elements such as a positive electrode, a negative electrode, and an electrolyte.

[0212] Specifically, the battery outer container according to this embodiment is configured to cover a battery element including at least a positive electrode, a negative electrode, and an electrolyte with the battery outer container, with metal terminals connected to the positive electrode and the negative electrode protruding outward, so that a flange portion (a region where the sealing layers contact each other) is formed around the periphery of the battery element. The heat-fusible resin layers of the flange portion are then heat-sealed to provide a battery using the battery outer container. When the battery outer container according to this embodiment is used to house a battery element, the sealing layer of the battery outer container is positioned on the inside, i.e., the surface that contacts the battery element.

[0213] The battery outer casing according to this embodiment may be used for either a primary battery or a secondary battery, but is preferably a secondary battery. The type of secondary battery to which the battery outer casing according to this embodiment is applied is not particularly limited, and examples include alkali metal ion batteries such as lithium ion batteries, alkali metal ion polymer batteries such as lithium ion polymer batteries, lead acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, and polyvalent cation batteries. It may also be used as an outer casing for a condenser or capacitor. Among these secondary batteries, alkali metal ion batteries and alkali metal ion polymer batteries are preferred applications of the battery outer casing according to this embodiment, with lithium ion batteries and lithium ion polymer batteries being more preferred.

[0214] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Note that the values ​​of various production conditions and evaluation results in the following examples represent preferred upper or lower limit values ​​in the embodiments of the present invention, and a preferred range may be defined by a combination of the above-mentioned upper or lower limit values ​​and the values ​​in the following examples or values ​​between the examples.

[0215] <<Measurement and Evaluation Methods>> <Modification Ratio of Component (A)> Pellets of the modified propylene-based block copolymer or the composition were press-molded (230°C) into a 100 μm-thick film, and the modification ratio (graft ratio) was calculated by infrared absorption spectroscopy using an FT-IR device (JASCO FT / IR610, manufactured by JASCO Corporation) as described above. The modification ratio (graft ratio) of the composition corresponds to the content of unsaturated carboxylic acid components (unsaturated carboxylic acids and their derivatives) in the composition.

[0216] <MFR> The MFR of the modified propylene-based block copolymer (A) was measured in accordance with JIS K7210:2014 under conditions of 180°C, a load of 2.16 kg, 10 minutes, and a 1 mm orifice diameter. The MFRs of the propylene-based block copolymer before modification to obtain component (A), the unmodified propylene-based polymer (B), the olefin-based elastomer (C), and the olefin-based polymer having intramolecular long-chain branches (D) were measured in accordance with JIS K7210:2014 under conditions of 230°C, a load of 2.16 kg, 10 minutes, and a 2 mm orifice diameter. The MFR of the low-density polyethylene (D) was measured in accordance with JIS K7210:2014 under conditions of 190°C, a load of 2.16 kg, 10 minutes, and a 2 mm orifice diameter. The MFR of the obtained composition was measured in accordance with JIS K7210:2014 under the conditions of a temperature of 230°C, a load of 2.16 kg, 10 minutes, and a 2 mm diameter orifice.

[0217] The melting points of the components and the resulting compositions were measured using a differential scanning calorimeter (DSC). Specifically, the temperature was first raised to 200°C to erase the thermal history, then lowered to 40°C at a rate of 10°C / min, and then raised again at a rate of 10°C / min. The melting point (°C) was determined as the temperature at the top of the endothermic peak.

[0218] <Haze> The haze of each component was measured at a thickness of 1 mm using a haze meter (Nippon Denshoku Industries Co., Ltd. NDH-7000II) in accordance with ISO 14782:2021.

[0219] <Flexural Modulus> The flexural modulus of each component was measured in accordance with ISO 178:2019 using a bending tester (Shimadzu Autograph AG2000A).

[0220] <Density> The density of each component was measured by the underwater displacement method in accordance with JIS K7112:1999.

[0221] The content of each monomer unit constituting each copolymer was determined by nuclear magnetic resonance spectroscopy or infrared spectroscopy. Here, the term "monomer unit" refers to a repeating unit derived from a raw material monomer of the copolymer and introduced into the copolymer.

[0222] <Adhesion> To evaluate the adhesion to metals when the obtained composition was used as an adhesive layer, the adhesive strength to metallic aluminum was measured. Specifically, first, an extrusion sheet molding machine (TPM-20S model manufactured by Thermoplastics Industry Co., Ltd.) equipped with a 200 mm wide T-die equipped with an extruder with a bore of 20 mmφ (diameter) was used, and the temperature of the molten composition was set to 180 to 220°C, and the surface temperature of the cooling roll was set to 30°C, and the extrusion amount and take-up speed were adjusted so that the adhesive sheet had a width of 150 mm and a layer thickness of 50 μm, to obtain an adhesive sheet made of the composition.

[0223] The adhesive sheet obtained above was cut into 100 mm x 50 mm pieces with the short side in the direction perpendicular to the extrusion direction (TD direction), and these were stacked in the following order: aluminum foil-PET composite film / adhesive sheet / polypropylene (PP)-PET composite film. The adhesive sheet was placed so that it was in contact with the aluminum foil side and the PP side of each composite film. The aluminum foil-PET composite film used was Alpet 12-50 (manufactured by Panac Corporation, thickness 62 μm).

[0224] The adhesive sheet was placed so that the long side was parallel to the heat seal bar, and heat-pressed at 180°C, 0.2 MPa, and for a pressing time of 1 second to produce a heat seal film (seal sample). The heat seal film obtained above was cut into 15 mm wide strips perpendicular to the sealing direction to prepare test pieces.

[0225] Using the above test pieces, a T-peel test was performed at a speed of 300 mm / min in a constant temperature atmosphere of 23°C to measure adhesive strength. The adhesive strength measured here is the adhesive strength at the interface between the metal (metallic aluminum) of the aluminum foil-PET composite film and the adhesive sheet layer. Adhesive strengths of more than 10 N / 15 mm were judged to be sufficient for practical use, and the higher the adhesive strength, the better the evaluation.

[0226] <Whitening Resistance> An adhesive sheet was obtained using an extrusion sheet molding machine in the same manner as described above in <Adhesion>. This adhesive sheet was punched out to the JIS No. 2 test piece size specified in JIS Z2248:2014 in both the extrusion direction (MD) and the direction perpendicular to the extrusion direction (TD) to prepare test pieces. Tensile tests were performed on the test pieces obtained in each direction at a rate of 500 mm / min in a constant temperature atmosphere of 23°C. The point at which the test piece began to whiten (whitening initiation point) was visually observed, and the elongation up to whitening was calculated as whitening resistance (%) using the following formula. The initial grip distance in the formula was 80 mm. Whitening resistance of more than 450% was evaluated as good. Whitening resistance (%) = {[gripper movement distance (mm) to whitening initiation point] / [initial gripper distance (mm)]} × 100

[0227] <Solvent Resistance> For the compositions obtained in Examples 3 and 5, injection test pieces measuring 80 mm in length, 10 mm in width, and 4 mm in thickness were obtained using an injection molding machine (Shibaura Machine IS130GN-5A) with a JIS family mold under conditions of a melt temperature of 230 to 240°C, a mold temperature of 40°C, an average injection speed of 200 mm / sec, and a dwell time of 40 seconds. The test pieces obtained above were immersed in toluene or ethyl acetate at 60°C and removed after 24 hours.

[0228] After removing the test piece from the solvent, the test piece was weighed within 30 minutes, and the weight change rate of the test piece before and after immersion was calculated as solvent resistance (%) using the following formula: Solvent resistance (%) = {[Test piece weight (g) after immersion] / [Test piece weight (g) before immersion]} × 100

[0229] <Molding Processability; Neck-in> The compositions obtained in Examples 3 and 6 were supplied to an extruder with a bore of 40 mmφ (diameter) attached to an extrusion laminating device having a T-die (manufactured by Sumitomo Heavy Industries Modern Co., Ltd.). Next, the temperature of the extruded resin was set to 255 to 275°C, and the extrusion rate was adjusted so that the coating thickness of the composition layer was 40 μm under the conditions of an air gap of 120 mm, a cooling roll surface temperature of 20°C, a die width of 360 mm, a die lip opening of 0.7 mm, and a take-up speed of 20 m / min, thereby forming a film. A laminated film was obtained in which a layer of the composition was laminated on kraft paper.

[0230] The width of the layer made of the composition of the obtained laminated film was measured, and the difference between the die width (effective width: 360 mm) and the width of the layer made of the composition, i.e., the value obtained by subtracting the width of the layer made of the composition from the effective width, was taken as the neck-in value. A neck-in value of 150 mm or less can be said to be good, 100 mm or less is more preferable, and the smaller the value, the better.

[0231] <Molding processability; drawdown property> For the compositions obtained in Examples 3 and 6, under the extrusion lamination molding conditions in the above <Molding processability; neck-in>, the take-up speed was increased from 10 m / min, and the limit speed at which the film made of the molten composition broke or the edge of the film flowed unstably was measured as the drawdown property (m / min). A drawdown property of 20 m / min or more is considered to be good, and 50 m / min or more is more preferable, and the higher the drawdown property, the better.

[0232] Examples and Comparative Examples The components used in producing the compositions in the examples and comparative examples are as follows.

[0233] <Component (A): Modified Propylene-Based Block Copolymer> (A)-1 Propylene-based block copolymer before modification Density: 0.89 g / cm ３, MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 6.0 g / 10 min, melting point: 131°C, flexural modulus: 280 MPa ... (a1) component: 60 mass% (copolymer having a propylene unit content of 96.5 mass% and an ethylene unit content of 3.5 mass%) ... (a2) component: 40 mass% (copolymer having a propylene unit content of 89 mass% and an ethylene unit content of 11 mass%) ... Modified propylene-based block copolymer, modifier: maleic anhydride, modification rate (graft rate): 1.0 mass%, density: 0.89 g / cm ３ MFR (temperature 180°C, load 2.16 kg, 1 mm orifice diameter): 11 g / 10 min, melting point: 135°C, Haze (1 mmt sheet): 36, flexural modulus: 310 MPa

[0234] (A)-2 Propylene block copolymer density before modification: 0.89 g / cm ３ , MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 2.0 g / 10 min, melting point: 164°C, flexural modulus: 610 MPa ... (a1) component: 60 mass% (propylene homopolymer having a propylene unit content of 100 mass% and an ethylene unit content of 0 mass%) ... (a2) component: 40 mass% (copolymer having a propylene unit content of 83 mass% and an ethylene unit content of 17 mass%) ... Modified propylene-based block copolymer, modifier: maleic anhydride, modification rate (graft rate): 1.3 mass%, density: 0.89 g / cm ３ , MFR (temperature 180°C, load 2.16 kg, 1 mm orifice diameter): 3 g / 10 min, melting point: 161°C, Haze (1 mmt sheet): 55, flexural modulus: 570 MPa

[0235] (A)-3 Propylene block copolymer density before modification: 0.88 g / cm ３, MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 0.8 g / 10 min, melting point: 164°C, flexural modulus: 320 MPa ... (a1) component: 46 mass% (propylene homopolymer having a propylene unit content of 100 mass% and an ethylene unit content of 0 mass%) ... (a2) component: 54 mass% (copolymer having a propylene unit content of 65 mass% and an ethylene unit content of 35 mass%) ... Modified propylene-based block copolymer, modifier: maleic anhydride, modification rate (graft rate): 1.2 mass%, density: 0.88 g / cm ３ , MFR (temperature 180°C, load 2.16 kg, 1 mm orifice diameter): 0.3 g / 10 min, melting point: 161°C, Haze (1 mmt sheet): 99, flexural modulus: 250 MPa

[0236] (A')-4 (modified propylene-based polymer for comparison) Density of propylene-based block copolymer before modification: 0.89 g / cm ３ , MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 0.8 g / 10 min, melting point: 164°C, flexural modulus: 330 MPa ... (a1) component: 40 mass% (propylene homopolymer having a propylene unit content of 100 mass% and an ethylene unit content of 0 mass%) ... (a2) component: 60 mass% (copolymer having a propylene unit content of 42 mass% and an ethylene unit content of 58 mass%) ... Modified propylene-based block copolymer, modifier: maleic anhydride, modification rate (graft rate): 1.2 mass%, density: 0.89 g / cm ３ MFR (temperature 180°C, load 2.16 kg, 1 mm orifice diameter): 0.3 g / 10 min, melting point: 158°C, Haze (1 mmt sheet): 99, flexural modulus: 220 MPa

[0237] (A')-5 (modified propylene polymer for comparison) Commercially available propylene-ethylene random copolymer before modification Density: 0.89 g / cm ３, MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 30.0 g / 10 min, melting point: 143°C, flexural modulus: 1250 MPa ... Modified propylene-ethylene random copolymer Modifier: maleic anhydride Modification rate (graft rate): 1.1 mass%, MFR (temperature 180°C, load 2.16 kg, 1 mm orifice diameter): 70 g / 10 min, melting point: 140°C, Haze (1 mmt sheet): 50

[0238] (A')-6 (modified propylene polymer for comparison) Commercially available propylene homopolymer before modification Density: 0.90 g / cm ３ , MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 10.0 g / 10 min, melting point: 162°C, flexural modulus: 1480 MPa ... Modified propylene homopolymer Modifier: maleic anhydride Modification rate (graft rate): 2.5 mass% MFR (temperature 180°C, load 2.16 kg, 1 mm orifice diameter): 400 g / 10 min, melting point: 158°C, Haze (1 mmt sheet): 99, flexural modulus: not measurable (the molecular weight was too low to prepare a test piece).

[0239] (A')-7 (modified propylene polymer for comparison) Commercially available propylene homopolymer before modification Density: 0.90 g / cm ３ , MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 0.6 g / 10 min, melting point: 161°C, flexural modulus: 1500 MPa ... Modified propylene homopolymer Modifier: maleic anhydride Modification rate (graft rate): 1.8 mass%, MFR (temperature 180°C, load 2.16 kg, 1 mm orifice diameter): 12 g / 10 min, melting point: 155°C, Haze (1 mmt sheet): 99

[0240] <Component (B): Unmodified Propylene-Based Polymer> (B)-1: Propylene-Based Block Copolymer Density: 0.89 g / cm ３, MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 2.0 g / 10 min, melting point: 164°C, Haze (1 mmt sheet): 81, Flexural modulus: 610 MPa, no branched structure... (a1) component: 60 mass% (propylene homopolymer having a propylene unit content of 100 mass% and an ethylene unit content of 0 mass%)... (a2)' component: 40 mass% (copolymer having a propylene unit content of 83 mass% and an ethylene unit content of 17 mass%)

[0241] (B)-2 Commercially available propylene-ethylene-butene random copolymer Density: 0.90 g / cm ３ , MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 6.5 g / 10 min, melting point: 145°C, Haze (1 mmt sheet): 64, flexural modulus: 850 MPa, no branched structure, components: propylene unit content 96 mass%, ethylene unit content 3 mass%, butene unit content 1 mass%

[0242] (B)-3 Commercially available propylene-ethylene random copolymer Density: 0.90 g / cm ３ , MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 7.0 g / 10 min, melting point: 125°C, flexural modulus: 750 MPa, Haze (1 mmt sheet): 61, no branched structure, components: propylene unit content 97 mass%, ethylene unit content 3 mass%

[0243] <Component (C): Olefin-based elastomer> (C)-1: Ethylene-propylene copolymer Density: 0.87 g / cm ３ MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 5.4 g / 10 min, melting point: 36°C, components: ethylene unit content 75% by mass, propylene unit content 25% by mass

[0244] (C)-2 Ethylene-butene copolymer Density: 0.89 g / cm ３ MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 6.7 g / 10 min, melting point: 77°C, components: ethylene unit content 85% by mass, butene unit content 15% by mass

[0245] (C)-3 Ethylene-butene copolymer Density: 0.89 g / cm ３ MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 4.0 g / 10 min, melting point: 75°C, components: ethylene unit content 85% by mass, butene unit content 15% by mass

[0246] (C)-4 Propylene-ethylene copolymer Density: 0.87 g / cm ３ MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 2.5 g / 10 min, melting point: 59°C, components: propylene unit content 89 mass%, ethylene unit content 11 mass%

[0247] (C)-5 Propylene-ethylene copolymer Density: 0.86 g / cm ３ MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 3.0 g / 10 min, melting point: 95°C, components: propylene unit content 84 mass%, ethylene unit content 16 mass%

[0248] <Component (D): Olefin-Based Polymer> (D)-1: Polymerized long-chain branched propylene homopolymer (manufactured by Japan Polypropylene Corporation, "WAYMAX (registered trademark) MFX3") Density: 0.91 g / cm ３ MFR (temperature 230°C, load 2.16 kg, 2 mm orifice diameter): 8 g / 10 min, melting point: 156°C

[0249] (D)-2 High-pressure low-density ethylene homopolymer (manufactured by Japan Polyethylene Corporation, "Novatec (registered trademark) LS500") Density: 0.92 g / cm ３ MFR (temperature 190°C, load 2.16 kg, 2 mm orifice diameter): 4.0 g / 10 min, melting point: 105°C

[0250] <Other Components> (X)-1: Phosphorus-based antioxidant (manufactured by BASF, "IRGAFOS (registered trademark) 168") (X)-2: Phenol-based antioxidant (manufactured by BASF, "IRGANOX (registered trademark) 1010") (Y)-1: Neutralizing agent, hydrotalcite compound (manufactured by Kyowa Chemical Industry Co., Ltd., "DHT4A")

[0251] Examples 1 to 11 and Comparative Examples 1 to 6 As components (A) to (D), the components shown in Table 1 were blended in the proportions (parts by mass) shown in Table 1. At this time, 0.05 parts by mass of (X)-1, 0.04 parts by mass of (X)-2, and 0.15 parts by mass of (Y)-1 were also blended relative to 100 parts by mass of the total of components (A) to (D). Note that blank spaces in Table 1 indicate that no components were blended. The components were dry-blended and mixed, and melt-kneaded using a single-screw extruder (IKG, PSM50-32(1V), D = 50 mm, L / D = 32, L: screw length, D: screw diameter) at a set temperature of 180 to 210°C, a screw rotation speed of 40 to 70 rpm, and an extrusion rate of 15 to 40 kg / hour. Subsequently, pellets of the composition were obtained by strand cutting. The pellets of the obtained composition were used to carry out the above-described measurements and evaluations. The results of the modification rate, MFR, melting point, adhesive strength and whitening resistance of the composition are shown in Tables 1 to 3. The results of the solvent resistance of the composition are shown in Table 2, and the results of the molding processability are shown in Table 3.

[0252]

[0253]

[0254]

[0255] From the above results, the composition according to this embodiment has excellent adhesion to metals and also excellent whitening resistance. Furthermore, a comparison between Example 3 and Example 5 shows that the composition according to this embodiment also has excellent solvent resistance when the content of component (C) relative to component (A) and component (B) is set within a preferred range. When the composition according to this embodiment is used as an adhesive layer for an outer container for battery applications, high resistance to organic solvents is required. When used for such applications, high solvent resistance such as that of Example 3 is preferable.

[0256] Furthermore, a comparison between Examples 3 and 6 reveals that the use of low-density polyethylene as component (D) further improves molding processability.

[0257] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-116912) filed on July 22, 2024, the contents of which are incorporated herein by reference.

Claims

1. A composition comprising components (A) and (B), wherein component (A) is a modified propylene-based block copolymer obtained by modifying a propylene-based block copolymer having components (a1) and (a2) as constituent components with at least one selected from the group consisting of unsaturated carboxylic acids and derivatives thereof, component (a1) is a propylene homopolymer or a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is 90% by mass or more but less than 100% by mass, component (a2) is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is 60% by mass or more but less than 90% by mass, and component (B) is an unmodified propylene-based polymer having a melting point of 120°C or more.

2. The composition according to claim 1, wherein component (B) is a propylene-based block copolymer having component (a1) and component (a2)' as constituent components, and component (a2)' is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, the propylene monomer content of which is 10% by mass or more but less than 90% by mass.

3. The composition according to claim 2, wherein component (B) is a propylene-based block copolymer having no branched structure or having short-chain branches in the molecular chain.

4. The composition according to claim 2, wherein in component (B), the content of component (a1) is 30% by mass or more and 80% by mass or less, and the content of component (a2)' is 20% by mass or more and 70% by mass or less.

5. The composition according to claim 1, wherein the modification rate of component (A) is 0.1% by mass or more and 5.0% by mass or less.

6. The composition described in claim 1, wherein the content of the component (a1) relative to the total content of the component (a1) and the component (a2) in the component (A) is 30 mass% or more and 80 mass% or less.

7. The composition of claim 1, wherein component (A) has a flexural modulus, measured in accordance with ISO 178:2019, of 100 MPa or greater and 700 MPa or less.

8. The composition according to claim 1, wherein the component (A) has a haze of 90 or less at a thickness of 1 mm measured in accordance with ISO 14782:2021.

9. The composition of claim 1, wherein component (B) has a flexural modulus, measured in accordance with ISO 178:2019, of 100 MPa or more and 1300 MPa or less.

10. The composition according to claim 1, wherein the component (B) has a haze of 90 or less at a thickness of 1 mm measured in accordance with ISO 14782:2021.

11. The composition according to claim 1, wherein the content of component (A) relative to the total of component (A) and component (B) is 3% by mass or more and 60% by mass or less.

12. The composition according to claim 1, further comprising an olefinic elastomer as component (C), wherein the olefinic elastomer has a melting point of less than 100°C or has no melting point.

13. The composition described in claim 12, wherein the content of component (C) is 5 parts by mass or more and 33 parts by mass or less per 100 parts by mass of the total of component (A) and component (B).

14. The composition according to claim 12, further comprising, as component (D), an olefin polymer having a long-chain branched structure in the molecule.

15. The composition according to claim 14, wherein the olefin polymer of component (D) comprises a low-density polyethylene having a melting point of 100°C or higher.

16. The composition described in claim 14, wherein the content of component (C) is 5 parts by mass or more and 33 parts by mass or less, and the content of component (D) is 5 parts by mass or more and 33 parts by mass or less, relative to 100 parts by mass of the total of component (A) and component (B).

17. A laminate having a substrate layer, an adhesive layer made of the composition according to any one of claims 1 to 16, and a seal layer.

18. The laminate according to claim 17, wherein the base layer, the adhesive layer, and the seal layer are laminated in this order.

19. The laminate according to claim 17, wherein the substrate layer is made of a metal foil, a vapor-deposited film, or a resin film having barrier properties.

20. The laminate according to claim 19, wherein the substrate layer is made of a metal foil, and the metal foil is an aluminum alloy foil or a stainless steel foil.

21. The laminate of claim 17, wherein the sealing layer contains a propylene-based polymer.

22. An outer container having a substrate layer, an adhesive layer made of the composition according to any one of claims 1 to 16, and a sealing layer.

23. The outer container according to claim 22, wherein the base material layer, the adhesive layer, and the seal layer are laminated in this order.

24. The outer container according to claim 22, wherein the substrate layer is made of a metal foil, a vapor-deposited film, or a resin film having barrier properties.

25. The outer container according to claim 24, wherein the substrate layer is made of a metal foil, and the metal foil is an aluminum alloy foil or a stainless steel foil.

26. The outer packaging of claim 25, which is an outer packaging for a battery.

27. A method for producing a composition, comprising: a step of starting production of component (a2) after starting production of component (a1), thereby obtaining a propylene-based block copolymer; a step of reacting the obtained propylene-based block copolymer with at least one compound selected from the group consisting of unsaturated carboxylic acids and their derivatives in the presence of a radical generator to obtain a modified propylene-based block copolymer; and a step of melt-kneading the obtained modified propylene-based block copolymer with a propylene-based polymer having a melting point of 120°C or higher to obtain a composition, wherein component (a1) is a propylene homopolymer or a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is 90% by mass or more but less than 100% by mass, and component (a2) is a copolymer of propylene and another α-olefin having 2 to 8 carbon atoms, wherein the propylene monomer content is 60% by mass or more but less than 90% by mass.

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