Adhesive composition and adhesive sheet

Abstract

The present application provides an adhesive composition comprising: (A) an isobutylene-based polymer having a crosslinked structure formed by the reaction of an epoxy group with an anhydride group and / or a carboxyl group; and (B) at least one selected from an alkoxide having a metal of valence 2 or more as a central metal, a carboxylate having a metal of valence 2 or more as a central metal, and a chelate having a metal of valence 2 or more as a central metal, wherein the isobutylene-based polymer has a polymer chain as a side chain, the polymer chain containing a structural unit derived from an alkyl (meth)acrylate having an alkyl group with a carbon number of 6 or more.

Description

Technical Field

[0001] This invention relates to adhesive compositions and adhesive sheets. Background Technology

[0002] To manufacture flexible and bendable electronic devices, laminates are obtained by stacking multiple films or sheets. For laminates used in the manufacture of flexible electronic devices, in addition to the durability required in conventional electronic device manufacturing, it is also required that they suppress peeling or bubbling (i.e., excellent bending resistance) even when bent. Therefore, the adhesive composition used to form the aforementioned laminate requires excellent adhesion and bending resistance.

[0003] For example, Patent Document 1 discloses a sealing composition as a sealing material that can be used in the manufacture of flexible electronic devices. The composition comprises a polyolefin resin and / or a polyolefin rubber, an inorganic filler, and a metal complex formed by combining a bidentate ligand with two oxygen atoms as coordinating atoms and a monodentate ligand with an oxygen atom as coordinating atoms with a central metal.

[0004] Existing technical documents Patent documents Patent document 1: International Publication No. 2019 / 189723. Summary of the Invention

[0005] The problem that the invention aims to solve Polyimide is often used as part of the laminates that constitute flexible electronic devices. Therefore, adhesive compositions with excellent adhesion to polyimide (especially at high temperatures) and flexural strength are required.

[0006] This invention was made with regard to the situation described above, and its purpose is to provide an adhesive composition with excellent adhesion and flexural strength (especially for polyimide at high temperatures).

[0007] Methods for solving problems The present invention, which achieves the above objectives, is described below; [1] An adhesive composition comprising: (A) An isobutylene polymer having a cross-linked structure formed by the reaction of epoxy groups with acid anhydride groups and / or carboxyl groups; and (B) Selected from at least one of the following: alkoxides with a metal of valence of 2 or higher as the central metal, carboxylates with a metal of valence of 2 or higher as the central metal, and chelates (chelate compounds) with a metal of valence of 2 or higher as the central metal. The isobutylene-based polymer has a polymer chain as a side chain, and the polymer chain contains structural units derived from alkyl (meth)acrylates having an alkyl group having 6 or more carbon atoms. [2] According to the adhesive composition described above [1], the concentration of the structural unit of the isobutylene polymer derived from the alkyl (meth)acrylate having an alkyl group having 6 or more carbon atoms is 0.005 to 5 mmol / g; [3] According to the adhesive composition described in [1] or [2] above, wherein the aforementioned isobutylene polymer is selected from at least one of (a1) and (a2) below, (a1) The reaction product of an isobutylene-isoprene copolymer having epoxy groups and an olefin polymer having anhydride groups and / or carboxyl groups. (a2) The reaction product of isobutylene-isoprene copolymers having anhydride and / or carboxyl groups with olefin polymers having epoxy groups. Furthermore, at least one of the isobutylene-isoprene copolymer and the olefin polymer has a polymer chain as a side chain, the polymer chain comprising structural units derived from alkyl (meth)acrylates having an alkyl group having 6 or more carbon atoms; [4] The adhesive composition according to any one of [1] to [3] above, wherein the metal with a valence of 2 or above is a metal of Group IVB (Group 4) of the periodic table or a metal of Group IIIA (Group 13) of the periodic table; [5] The adhesive composition according to any one of [1] to [3] above, wherein the metal with a valence of 2 or more is aluminum, titanium or zirconium; [6] The adhesive composition according to any one of [1] to [5] above, wherein it further comprises (C) a liquid polyolefin resin and / or a liquid rubber; [7] Adhesive sheets, which have a laminated structure, The stacked structure includes: The adhesive composition layer formed by any one of the adhesive compositions described in [1] to [6] above, and Support body.

[0008] The effects of the invention This invention provides an adhesive composition with excellent adhesion and flexural strength (especially for polyimide at high temperatures). Detailed Implementation

[0009] The adhesive composition of the present invention is characterized in that it comprises: (A) An isobutylene polymer having a cross-linked structure formed by the reaction of epoxy groups with acid anhydride groups and / or carboxyl groups; and (B) Selected from at least one of an alkoxide with a metal of valence of 2 or more as the central metal, a carboxylate of a metal of valence of 2 or more, and a chelate of a metal of valence of 2 or more, wherein the isobutylene polymer has a polymer chain as a side chain, the polymer chain comprising a structural unit derived from an alkyl (meth)acrylate having an alkyl group having 6 or more carbon atoms.

[0010] In this specification, "(meth)acrylate" refers to "alkyl acrylate or alkyl methacrylate". Both alkyl acrylate and alkyl methacrylate may also be used.

[0011] From an adhesive viewpoint, the alkyl group in the aforementioned "alkyl (meth)acrylate having an alkyl group" must have 6 or more carbon atoms. This number of carbon atoms is preferably 7 or more, more preferably 8 or more. There is no particular upper limit to this number of carbon atoms, but from the viewpoint of reducing the glass transition temperature of the adhesive composition for use in flexible electronic devices, this number of carbon atoms is preferably 30 or less, more preferably 24 or less, even more preferably 22 or less, even more preferably 20 or less, further preferably 18 or less, particularly preferably 16 or less, especially more preferably 14 or less, and most preferably 12 or less. The alkyl group can be either linear or branched.

[0012] In this specification, "alkyl (meth)acrylate having an alkyl group having 6 or more carbon atoms" is sometimes abbreviated as "(meth)acrylate long-chain alkyl ester", and "structural unit from (meth)acrylate long-chain alkyl ester" is abbreviated as "(meth)acrylate long-chain alkyl ester unit". Other structural units are also sometimes abbreviated in the same way.

[0013] In this specification, "polymer chain containing (meth)acrylic long-chain alkyl ester units" is sometimes referred to as "(meth)acrylic long-chain alkyl ester polymer chain", and "isobutylene polymer having a cross-linked structure formed by the reaction of epoxy groups with acid anhydride groups and / or carboxyl groups, and (meth)acrylic long-chain alkyl ester polymer chains as side chains" is sometimes referred to as "cross-linked isobutylene polymer having (meth)acrylic long-chain alkyl ester polymer chains".

[0014] In this specification, sometimes “crosslinked isobutylene polymer having a (meth)acrylate long-chain alkyl ester polymer chain” is described as “(A) component”, and “(B) is selected from at least one of an alkoxide with a metal of valence of 2 or more as the central metal, a carboxylate compound of a metal of valence of 2 or more as the central metal, and a chelate of a metal of valence of 2 or more as the central metal”.

[0015] In this invention, the adhesion of polyimide at high temperatures can be improved by using component (A). The mechanism is inferred as follows: since component (A) has a long-chain alkyl ester polymer chain of (meth)acrylate, the cohesive force of component (A) is increased, resulting in improved adhesion of the adhesive composition containing component (A). However, this invention is not limited to such a mechanism.

[0016] In this invention, bending resistance is improved by using components (A) and (B) together. The mechanism is inferred as follows: the carboxyl and / or hydroxyl groups in component (A), formed by the reaction of epoxy groups with anhydride groups and / or carboxyl groups, crosslink with component (B), thereby improving the bending resistance of the adhesive composition containing components (A) and (B). However, this invention is not limited to such an inferred mechanism.

[0017] The components that can be used in the adhesive composition of the present invention will be described in turn below. Each component may be used in isolation or in combination of two or more.

[0018] <(A)Component> The adhesive composition of the present invention comprises a crosslinked isobutylene polymer having long-chain alkyl ester polymer chains of (meth)acrylate (component (A)). The side chains (i.e., the long-chain alkyl ester polymer chains of (meth)acrylate) may be formed from homopolymers or copolymers. The copolymer may be a block polymer or a random copolymer. The crosslinking structure in component (A) is preferably a structure formed by the reaction of epoxy groups with acid anhydride groups.

[0019] (A) The component may contain only one type of (meth)acrylate long-chain alkyl ester unit, or it may contain two or more (meth)acrylate long-chain alkyl ester units. Examples of (meth)acrylate long-chain alkyl esters include: 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate (also known as: lauryl (meth)acrylate). Among these, 2-ethylhexyl (meth)acrylate and lauryl (meth)acrylate are preferred, and 2-ethylhexyl acrylate and lauryl methacrylate are more preferred.

[0020] The concentration of the (meth)acrylate long-chain alkyl ester unit in component (A) is preferably 0.005 to 5 mmol / g, more preferably 0.007 to 3 mmol / g, and even more preferably 0.01 to 1 mmol / g. Here, "concentration of the (meth)acrylate long-chain alkyl ester unit in component (A)" refers to the amount (mmol) of the (meth)acrylate long-chain alkyl ester unit per 1g of component (A). The concentration of other units has the same meaning. The concentration of the (meth)acrylate long-chain alkyl ester unit in component (A) can be calculated, for example, from the concentration of the (meth)acrylate long-chain alkyl ester unit in the raw material of component (A) (e.g., the epoxy-containing isobutylene-isoprene copolymer, etc., described later). Alternatively, the concentration of the (meth)acrylate long-chain alkyl ester unit in the raw material of component (A) can be calculated from the amount of monomer used during its synthesis.

[0021] In this specification, "isobutylene-based polymer" refers to a polymer in which isobutylene structural units (hereinafter sometimes simply referred to as "isobutylene units") are the main structural units (i.e., the amount of isobutylene units is the largest among all structural units). The isobutylene-based polymer is preferably an isobutylene-isoprene copolymer (i.e., butyl rubber). In this invention, relative to the total amount of isobutylene units and isoprene units, the amount of isoprene units in the isobutylene-isoprene copolymer is preferably 0.1 to 20% by mass, more preferably 0.3 to 15% by mass, and even more preferably 0.5 to 10% by mass.

[0022] In one aspect of the present invention (hereinafter referred to as "aspect (1)"), component (A) is selected from at least one of (a1) and (a2). (a1) The reaction product of an isobutylene-isoprene copolymer having epoxy groups and an olefin polymer having anhydride and / or carboxyl groups (hereinafter sometimes referred to as "reaction product (a1)"). (a2) The reaction product of isobutylene-isoprene copolymer having an anhydride group and / or a carboxyl group with an olefin polymer having an epoxy group (hereinafter sometimes referred to as "reaction product (a2)") Furthermore, at least one of the aforementioned isobutylene-isoprene copolymer and the aforementioned olefin polymer has a (meth)acrylic acid long-chain alkyl ester polymer chain as a side chain.

[0023] In this specification, "olefin polymer" refers to a polymer in which the structural unit derived from olefins (hereinafter sometimes simply referred to as "olefin unit") is the main structural unit (i.e., the amount of olefin unit is the largest among all structural units).

[0024] As olefins, monoolefins having one olefinic carbon-carbon double bond and / or dienes having two olefinic carbon-carbon double bonds are preferred. Examples of monoolefins include α-olefins such as ethylene, propylene, 1-butene, isobutene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. Examples of dienes include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethylbutadiene.

[0025] Olefin polymers can be homopolymers or copolymers. Copolymers can be random copolymers or block copolymers. In addition, olefin polymers can be copolymers of olefins and monomers other than olefins.

[0026] In method (1), either only one of the aforementioned isobutylene-isoprene copolymer and the aforementioned olefin polymer can be used, or two or more can be used together.

[0027] In method (1), the anhydride group and / or carboxyl group are preferably anhydride groups. In addition, in method (1), the olefin polymer is preferably an isobutylene polymer, more preferably an isobutylene-isoprene copolymer (i.e., butyl rubber).

[0028] In method (1), the concentration of epoxy groups in the isobutylene-isoprene copolymer and the concentration of epoxy groups in the olefin polymer are each preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g. This epoxy group concentration is determined by the epoxy group equivalent obtained based on JIS K 7236-1995.

[0029] In method (1), the concentration of anhydride groups in the isobutylene-isoprene copolymer having anhydride groups and the concentration of anhydride groups in the olefin polymer having anhydride groups are each preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g. The concentration of anhydride groups can be determined according to JIS K 2501 by the acid value, which is defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of resin.

[0030] In method (1), the concentration of carboxyl groups in the isobutylene-isoprene copolymer and the concentration of carboxyl groups in the olefin polymer are each preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g. The concentration of carboxyl groups can be determined according to JIS K 2501 by the acid value, which is defined as the number of mg of potassium hydroxide required to neutralize the acid present in 1 g of resin.

[0031] In method (1), the sum of the concentrations of anhydride groups and carboxyl groups in the isobutylene-isoprene copolymer having anhydride groups and carboxyl groups (i.e., "concentration of anhydride groups + concentration of carboxyl groups") and the sum of the concentrations of anhydride groups and carboxyl groups in the olefin polymer having anhydride groups and carboxyl groups are each preferably 0.01 to 10 mmol / g, more preferably 0.05 to 5 mmol / g.

[0032] In method (1), the number-average molecular weight (hereinafter sometimes referred to as "Mn") of the isobutylene-isoprene copolymer having an epoxy group, the Mn of the olefin polymer having an anhydride group and / or a carboxyl group, the Mn of the isobutylene-isoprene copolymer having an anhydride group and / or a carboxyl group, and the Mn of the olefin polymer having an epoxy group are each preferably 1,000 to 1,000,000, more preferably 20,000 to 500,000, and even more preferably 50,000 to 500,000. It should be noted that the Mn in this specification is a value determined by gel permeation chromatography (GPC) (converted to polystyrene). Specifically, the number-average molecular weight obtained by the GPC method can be measured using a Shimadzu Corporation "LC-9A / RID-6A" as the measuring device, a Showa Denko Corporation "Shodex K-800P / K-804L / K-804L" as the column, and toluene as the mobile phase, at a column temperature of 40°C, and calculated using a standard curve of standard polystyrene.

[0033] In method (1), the amount of isoprene units in component (A) is preferably 0.1 to 20% by mass, more preferably 0.3 to 15% by mass, and even more preferably 0.5 to 10% by mass, relative to the sum of isobutylene units and isoprene units.

[0034] The ratio of the amount (mol) of epoxy groups in the isobutylene-isoprene copolymer having epoxy groups to the amount (mol) of anhydride groups in the olefin polymer having anhydride groups (i.e., "amount of epoxy groups (mol): amount of anhydride groups (mol)") is preferably 100:20 to 100:1000, more preferably 100:30 to 100:400, and even more preferably 100:50 to 100:300.

[0035] The ratio of the amount (mol) of epoxy groups in the isobutylene-isoprene copolymer having epoxy groups to the amount (mol) of anhydride groups in the olefin polymer having carboxyl groups (i.e., "amount of epoxy groups (mol): amount of carboxyl groups (mol)") used to form the reaction product (a1) is preferably 100:20 to 100:1000, more preferably 100:30 to 100:400, and even more preferably 100:50 to 100:300.

[0036] The ratio of the amount (mol) of epoxy groups in the isobutylene-isoprene copolymer having epoxy groups used to form the reaction product (a1) to the sum of the amount (mol) of anhydride groups and the amount (mol) of carboxyl groups in the olefin polymer having carboxyl and anhydride groups (i.e., "amount (mol) of epoxy groups: (amount (mol) of anhydride groups + amount (mol) of carboxyl groups)") is preferably 100:20 to 100:1000, more preferably 100:30 to 100:400, and even more preferably 100:50 to 100:300.

[0037] The preferred ranges for the amount of epoxy groups (mol): anhydride groups (mol) used to form reaction product (a2) are the same as those described in reaction product (a1) (i.e., the preferred ranges for the amount of epoxy groups (mol): anhydride groups (mol) used to form reaction product (a1)). Similarly, the preferred ranges for the amount of epoxy groups (mol): carboxyl groups (mol) and the ratio of epoxy groups (mol): (anhydride groups (mol) + carboxyl groups (mol)) used to form reaction product (a2) are also the same as those described in reaction product (a1).

[0038] In one aspect of the present invention (hereinafter referred to as "aspect (2)"), component (A) is selected from at least one of (a3), (a4) and (a5) below: (a3) The reaction product of an isobutylene-isoprene copolymer having epoxy groups and polymer chains comprising long-chain alkyl ester units of (meth)acrylate as side chains, and an olefin polymer having an anhydride group and / or a carboxyl group (hereinafter sometimes referred to as "reaction product (a3)"). (a4) Isobutylene-isoprene copolymers having an anhydride group and / or a carboxyl group and a polymer chain comprising a long-chain alkyl ester unit of (meth)acrylate as a side chain, and reaction products with olefin polymers having an epoxy group (hereinafter sometimes referred to as "reaction product (a4)"), and (a5) An isobutylene-isoprene copolymer having an epoxy group and a polymer chain containing a long-chain alkyl ester unit of (meth)acrylic acid as a side chain, and a reaction product of an isobutylene-isoprene copolymer having an anhydride group and / or a carboxyl group and a polymer chain containing a long-chain alkyl ester unit of (meth)acrylic acid as a side chain (hereinafter sometimes referred to as "reaction product (a5)").

[0039] In method (2), either only one of the aforementioned isobutylene-isoprene copolymer and the aforementioned olefin polymer can be used, or two or more can be used together.

[0040] In method (2), component (A) is preferably selected from at least one of reaction product (a3) ​​and reaction product (a4). Furthermore, in method (2), the anhydride group and / or carboxyl group is preferably anhydride group. Additionally, in method (2), the olefin polymer is preferably an isobutylene polymer, more preferably an isobutylene-isoprene copolymer (i.e., butyl rubber).

[0041] In method (2), the preferred ranges, etc. of (i), (ii), (iii) and (iv) below are the same as the corresponding preferred ranges, etc., described in method (1) or reaction product (a1): (i) The concentrations of epoxy groups, anhydride groups, carboxyl groups, and the sum of the concentrations of anhydride groups and carboxyl groups in each polymer used to form reaction products (a3), (a4), and (a5). (ii) Mn of each polymer, (iii)(A) ​​The amount of isoprene units in the component, and (iv) The amounts of epoxy groups (mol): anhydride groups (mol), the amounts of epoxy groups (mol): carboxyl groups (mol) and the amounts of epoxy groups (mol): (anhydride groups (mol) + carboxyl groups (mol)) used to form reaction products (a3), (a4) and (a5)

[0042] Examples of isobutylene-isoprene copolymers containing epoxy groups and polymer chains comprising long-chain alkyl ester units of (meth)acrylate as side chains include, for example, butyl rubber modified from a copolymer of an epoxy-containing unsaturated compound and a long-chain alkyl ester of (meth)acrylate (i.e., isobutylene-isoprene copolymer). Here, "butyl rubber modified from a copolymer" means "butyl rubber having the aforementioned copolymer chain as a side chain." In this specification, this "butyl rubber modified from a copolymer" is sometimes referred to as "copolymer-modified butyl rubber," etc. Examples of epoxy-containing unsaturated compounds include, for example, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, allyl glycidyl ether, etc. Only one epoxy-containing unsaturated compound may be used, or two or more may be used in combination. Glycidyl methacrylate is preferred as the epoxy-containing unsaturated compound.

[0043] Examples of isobutylene-isoprene copolymers having an anhydride group and / or a carboxyl group and a polymer chain comprising a long-chain alkyl ester unit of (meth)acrylate as a side chain include, for example, butyl rubber modified from a copolymer of carboxylic anhydride and a long-chain alkyl ester of (meth)acrylate (i.e., isobutylene-isoprene copolymer). Examples of carboxylic anhydrides include, for example, succinic anhydride, maleic anhydride, and glutaric anhydride. Only one type of carboxylic anhydride may be used, or two or more may be used in combination. Maleic anhydride is preferred.

[0044] The butyl rubber modified by the epoxy-containing unsaturated compound-(meth)acrylate long-chain alkyl ester copolymer used in method (2) can be manufactured, for example, by grafting an addition monomer (i.e., an epoxy-containing unsaturated compound and a (meth)acrylate long-chain alkyl ester) onto butyl rubber or by the epoxy-containing unsaturated compound-(meth)acrylate long-chain alkyl ester copolymer. The butyl rubber modified by the carboxylic anhydride-(meth)acrylate long-chain alkyl ester copolymer can also be manufactured in the same way. Furthermore, these modified butyl rubbers can be obtained, for example, from Starlight PMC Corporation.

[0045] The olefin polymers with anhydride and / or carboxyl groups used in method (1) or (2) (e.g., isobutylene-isoprene copolymers with anhydride and / or carboxyl groups) can be manufactured by grafting the olefin polymers with an unsaturated compound (e.g., maleic anhydride) with anhydride and / or carboxyl groups under free radical reaction conditions.

[0046] As an olefinic polymer having an anhydride group and / or a carboxyl group used in method (1) or (2), the following substances can be obtained, for example. As an isobutylene-isoprene copolymer having an anhydride group and / or a carboxyl group, examples include, for example, "ER661" (maleic anhydride-butyl methacrylate random copolymer modified butyl rubber) manufactured by Starlight PMC Co., Ltd. Examples of olefin polymers having anhydride and / or carboxyl groups (excluding isobutylene-isoprene copolymers) include: "HV-300M" (maleic anhydride modified polybutene) manufactured by Toho Chemical Co., Ltd., "T-YP279" (maleic anhydride modified propylene-butene random copolymer) manufactured by Hoshikatsu PMC Co., Ltd., "T-YP312" (maleic anhydride modified propylene-butene random copolymer) manufactured by Hoshikatsu PMC Co., Ltd., "LUCANT A-5260" (maleic anhydride modified ethylene-α-olefin random copolymer) and "LUCANTA-5320" (maleic anhydride modified ethylene-α-olefin random copolymer) manufactured by Mitsui Chemicals Co., Ltd.

[0047] The epoxy-containing olefin polymers used in methods (1) or (2) (e.g., epoxy-containing isobutylene-isoprene copolymers) can be manufactured by grafting the olefin polymers with epoxy-containing unsaturated compounds (e.g., (meth)acrylate glycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, allyl glycidyl ether) under free radical reaction conditions.

[0048] As the epoxy-based olefin polymer used in method (1) or (2), the following substances can be obtained, for example. Examples of epoxy-based isobutylene-isoprene copolymers include: ER866 (glycidyl methacrylate modified butyl rubber) manufactured by Starlight PMC Corporation, and ER850 (glycidyl methacrylate modified butyl rubber) manufactured by Starlight PMC Corporation. Examples of epoxy-based olefin polymers (excluding isobutylene-isoprene copolymers) include: T-YP341 (glycidyl methacrylate modified propylene-butene random copolymer) manufactured by Starlight PMC Corporation, T-YP276 (glycidyl methacrylate modified propylene-butene random copolymer) manufactured by Starlight PMC Corporation, and T-YP313 (glycidyl methacrylate modified propylene-butene random copolymer) manufactured by Starlight PMC Corporation.

[0049] Regarding the content of component (A) in the adhesive composition, from the viewpoint of adhesion and flexural strength, it is preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, relative to 100% by mass of the non-volatile components in the adhesive composition.

[0050] <(B) Component> The adhesive composition of the present invention comprises at least one selected from the following: an alkoxide (hereinafter sometimes referred to as "metal alkoxide") with a metal of valence of 2 or more as the core metal, a carboxylate (hereinafter sometimes referred to as "metal carboxylate") with a metal of valence of 2 or more as the core metal, and a chelate (hereinafter sometimes referred to as "metal chelate") with a metal of valence of 2 or more as the core metal.

[0051] In this invention, "metal alkoxide" refers to a compound containing the structure shown in M-OR (where M represents a metal with a valence of 2 or higher, and R represents an organic group), and "metal carboxylate" refers to a compound containing the structure shown in MO-(CO)-R (where M represents a metal with a valence of 2 or higher, and R represents an organic group). Furthermore, "metal chelate" refers to a compound containing a chelate ring structure formed by the combination of a polydentate ligand and a central metal that is a metal with a valence of 2 or higher. It should be noted that compounds having a chelate ring structure and structures represented by M-OR or MO-(CO)-R are classified as "metal chelates" in this invention.

[0052] Metals with a valence of 2 or higher are preferably metals of Group IVB or Group IIIA of the periodic table, and more preferably aluminum, titanium or zirconium.

[0053] Examples of polydentate ligands that can be used to form metal chelates include, for example, compounds represented by the following formula (a) (hereinafter sometimes referred to as "compound (a)").

[0054] [Chemical Formula 1]

[0055] [In equation (a), the definitions of R1, R2, and R3 have the same meaning as the definitions of the corresponding symbols in equation (1) described later.]

[0056] Compound (a) represents a polydentate ligand coordinated before the central metal. It should be noted that, in this invention, polydentate ligands coordinated after the central metal and polydentate ligands coordinated before the central metal are sometimes referred to as "polydentate ligands" without special distinction. The specific examples of compounds shown in formula (a) have the same meaning as the specific examples of polydentate ligands in compounds shown in formula (1) described later.

[0057] (B) The preferred component is a metal complex as shown in formula (1) below (hereinafter sometimes simply referred to as "metal complex (1)").

[0058] [Chemical Formula 2]

[0059] In formula (1), M indicates a metal with a valence of divalent or higher. R1 and R3 each independently represent a hydrogen atom, alkyl, alkenyl, alkoxy, alkenyloxy, aryl, or aralkyl. R2 represents a hydrogen atom, alkyl, alkenyl, alkoxy, alkenyloxy, alkoxycarbonyl, aryl, or aralkyl. X represents a monodentate ligand. In equation (1), the solid line between the oxygen atom (O) in [] and M represents a covalent bond. In equation (1), the dashed line between the oxygen atom (O) in [] and M represents a coordinate bond, and m represents 3 or 4, n represents an integer from 0 to 4, and m ≥ n. Metal complexes (1) can use only one type or use two or more types together.

[0060] In this specification, examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0061] In this specification, the alkyl group can be any of the straight-chain or branched forms. The alkyl group (excluding the alkyl group in long-chain alkyl esters of (meth)acrylate) preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and particularly preferably 1 to 6. Examples of alkyl groups include: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, 1-ethylpropyl, hexyl, isohexyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 2-ethylbutyl, etc. The alkyl group may optionally have substituents. Examples of substituents include: halogen atoms, hydroxyl groups, and optionally substituents such as amino groups.

[0062] In this specification, the alkenyl group can be any of the linear or branched forms. The alkenyl group preferably has 2 to 20 carbon atoms. Examples of alkenyl groups include: ethenyl (i.e., vinyl), 1-propenyl, 2-propenyl, 2-methyl-1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 3-methyl-2-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 4-methyl-3-pentenyl, 1-hexenyl, 3-hexenyl, 5-hexenyl, etc. The alkenyl group may optionally have substituents. Examples of substituents include: halogen atoms, hydroxyl groups, and optionally substituted amino groups.

[0063] In this specification, the alkynyl group can be any of the straight-chain or branched forms. The number of carbon atoms in the alkynyl group is preferably 2 to 10, more preferably 2 to 6. Examples of alkynyl groups include: ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, 4-methyl-2-pentynyl, etc. The alkynyl group may optionally have substituents. Examples of substituents include: halogen atoms, hydroxyl groups, and optionally substituents such as amino groups.

[0064] In this specification, the aryl group preferably has 6 to 18 carbon atoms, more preferably 6 to 14. Examples of aryl groups include phenyl, 1-naphthyl, 2-naphthyl, 1-anthrayl, 2-anthrayl, and 9-anthrayl. The aryl group may optionally have substituents. Examples of substituents include halogen atoms, hydroxyl groups, alkyl groups optionally with substituents, alkenyl groups optionally with substituents, alkynyl groups optionally with substituents, and amino groups optionally with substituents.

[0065] In this specification, the aralkyl group preferably has 7 to 16 carbon atoms. Examples of aralkyl groups include benzyl, phenethyl, naphthylmethyl, and phenylpropyl. The aralkyl group may optionally have substituents. Examples of substituents include halogen atoms, hydroxyl groups, and amino groups that may optionally have substituents.

[0066] In this specification, examples of amino groups optionally having substituents include: amino groups, mono- or dialkylamino groups (e.g., methylamino, dimethylamino, ethylamino, diethylamino, propylamino, dibutylamino), mono- or dicycloalkylamino groups (e.g., cyclopropylamino, cyclohexylamino), mono- or diarylamino groups (e.g., phenylamino), mono- or diarylalkylamino groups (e.g., benzylamino, dibenzylamino), heterocyclic amino groups (e.g., pyridylamino), etc.

[0067] In this specification, the alkyl group in alkoxy (i.e., alkyloxy) is described in the same way as the alkyl group described above. Alkoxy groups may optionally have substituents. Examples of substituents include halogen atoms, hydroxyl groups, and optionally substituents such as amino groups.

[0068] In this specification, the description of the alkenyl group in the alkenyloxy group is the same as that of the alkenyl group described above. The alkenyloxy group may optionally have substituents. Examples of substituents include: halogen atoms, hydroxyl groups, and amino groups that may optionally have substituents.

[0069] In this specification, the alkyl group in alkoxycarbonyl (i.e., alkyloxycarbonyl) is described in the same way as the alkyl group described above. The alkoxycarbonyl group may optionally have substituents. Examples of substituents include halogen atoms, hydroxyl groups, and optionally substituents such as amino groups.

[0070] Examples of monodentate ligands as shown in X include: alkoxide anions (RO... - (In the aforementioned formula, R represents an organic group), carboxylate anion (RCOO) - (In the aforementioned formula, R represents an organic group), oxo (O), etc.

[0071] Alkyl salt anions from RO -(In the aforementioned formula, R represents an organic group). The organic group R can be any aliphatic or aromatic group. Furthermore, the aliphatic group can be any saturated or unsaturated aliphatic group. The organic group R preferably has 1 to 20 carbon atoms, more preferably 6 to 18, and particularly preferably 8 to 14. As an alkoxide anion (RO... - Examples of such salts include: methanol salts, ethanol salts, propanol salts, isopropanol salts, butanol salts, isobutanol salts, sec-butanol salts, tert-butanol salts, pentanol salts, hexanol salts, phenol salts, 4-methylphenol salts, etc.

[0072] The carboxylate anion is produced by RCOO - (In the aforementioned formula, R represents an organic group). The organic group R can be any aliphatic or aromatic group. Furthermore, the aliphatic group can be any saturated or unsaturated aliphatic group. The organic group R preferably has 1 to 20 carbon atoms, more preferably 6 to 18, and particularly preferably 8 to 14. As a carboxylate anion (RCOO... - Examples of carboxylic acid anions include those corresponding to acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, octylic acid, nonanoic acid, decanoic acid, dodecanoic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and benzoic acid.

[0073] The brackets [] in the formula represent polydentate ligands. Examples of polydentate ligands include: acetylacetone, 3-methyl-2,4-pentanedione, acetoacetaldehyde, 2,4-hexanedione, 2,4-heptanedione, 5-methyl-2,4-hexanedione, 5,5-dimethyl-2,4-hexanedione, benzoylacetone, benzoylacetophenone, salicylaldehyde, 1,1,1-trifluoroacetylacetone, 1,1,1,5,5,5-hexafluoroacetylacetone, 3-methoxy-2,4-pentanedione, 3-cyano-2,4-pentanedione, 3-nitro-2,4-pentanedione, 3-chloro-2,4-pentanedione, acetoacetic acid, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, salicylic acid, methyl salicylate, malonic acid, dimethyl malonate, diethyl malonate, etc. When coordinated with the central metal, the polydentate ligand becomes a structure formed by removing one or more protons from it.

[0074] Specific examples of metal complexes (1) with M being aluminum include: aluminum diisopropylate mono-sec-butyrate, aluminum tri-sec-butyrate, aluminum triisopropylate, aluminum triethanolate, aluminum triacetylacetonate, aluminum bis(ethylacetoacetate)mono(acetylacetonate), aluminum tris(ethylacetoacetate), and aluminum octadecenylacetate diisopropylate. diisopropylate, ethylaluminum diisopropyl acetoacetate, ethylaluminum di-n-butyl acetoacetate, propylaluminum diisopropyl acetoacetate, n-butylaluminum diisopropyl acetoacetate, tri(ethylacetoacetate)aluminum, diethylacetate ethanol-2,4-pentanedione aluminum (Aluminum mono(acetylacetonate)bis(ethylacetoacetate)), tri(acetylacetonate)aluminum.

[0075] Specific examples of titanium metal complexes (1) include: tetraisopropyl titanate, tetra-n-butyl titanate, tetraoctyl titanate, tetra-tert-butyl titanate, tetrastearyl titanate, titanium tetraacetylacetonate, titanium octylene glycol titanate (also known as bis(2-ethylhexyloxy)bis(2-ethyl-3-oxohexyloxy)titanium(IV)), diisopropyl bis(ethyl acetoacetate)titanium, titanium allyl acetoacetate triisopropoxide, and titanium di-n-butoxide. bis(2,4-pentanedionate), diisopropoxybis(tetramethylheptanedionate)titanium, diisopropyl bis(acetoacetate)titanium, titanium(IV)tetra(methylphenoxide), bis(2,4-pentanedione)titanium oxide, monoisopropyl triisostearate titanate, diisopropyl diisostearate titanate.

[0076] Specific examples of metal complexes (1) with M being zirconium include: zirconium tetra-n-propoxide (zirconium tetra-n-propoxide), zirconium tetra-n-butoxy, zirconium tetraacetylacetone, zirconium triisopropoxy acetoacetate, zirconium dibutoxybis(2,4-pentanedione), zirconium diisopropoxybis(2,4-pentanedione), zirconium diisopropoxybis(tetramethylheptanone), zirconium diisopropoxybis(ethoxyacetate), zirconium butoxide(acetylacetate)bis(ethylacetoacetate), zirconium tributoxide monoacetylacetonate, zirconium octanoate, zirconium stearate, tributyl zirconate monooctanoate, and tributyl zirconate monostearate.

[0077] In one embodiment of the present invention (hereinafter referred to as "embodiment (3)"), component (B) is a metal complex (1), wherein, M is aluminum, titanium, or zirconium. One of R1 and R3 is an alkyl, alkoxy, or alkenyloxy group, and the remaining one is an alkyl group. R2 is a hydrogen atom. X is an alkoxide anion or a carboxylate anion, and m is 3 or 4, n is an integer from 1 to 3, and m > n; In method (3), M is preferably aluminum or zirconium. Furthermore, the descriptions (preferred carbon number, examples, etc.) of the alkyl, alkoxy or alkenyloxy, alkoxide anion, and carboxylate anion in method (3) are as described above.

[0078] In one embodiment of the present invention (hereinafter referred to as "Amendment (4)"), component (B) is selected from at least one of the specific examples of the metal complex (1) in which M is aluminum, the specific examples of the metal complex (1) in which M is titanium, and the specific examples of the metal complex (1) in which M is zirconium. In Embodiment (4), component (B) is preferably selected from at least one of the specific examples of the metal complex (1) in which M is aluminum and the specific examples of the metal complex (1) in which M is zirconium, more preferably octadecenyl aluminum diisopropyl acetoacetate and / or zirconium tributoxymonoacetate (also known as "zirconium tributoxymonoacetate").

[0079] From the viewpoint of flexural strength, the content of component (B) in the adhesive composition is preferably 0.5% by mass or more, more preferably 1% by mass or more, more preferably 15% by mass or less, and more preferably 10% by mass or less, relative to 100% by mass of the non-volatile components of the adhesive composition.

[0080] <(C) Ingredients> The adhesive composition of the present invention may further comprise (C) a liquid polyolefin resin and / or a liquid rubber (sometimes referred to as "(C) component" in this specification). In this invention, "liquid" means a viscosity of 5,000 Pa·s or less at 25°C. Furthermore, in this invention, "viscosity at 25°C" refers to the viscosity calculated by multiplying the dynamic viscosity at 25°C, as measured by a dynamic viscoelasticity measuring device, by the density. Examples of dynamic viscoelasticity measuring devices include, for instance, a rheometer manufactured by TA Instruments (trade name: DISCOVERYHR-2).

[0081] Regarding component (C) of this invention, "liquid polyolefin resin" refers to an olefin polymer with a viscosity of 5,000 Pa·s or less at 25°C that cannot be cross-linked to form a rubber elastomer, and "liquid rubber" refers to a substance with a viscosity of 5,000 Pa·s or less at 25°C that can be cross-linked to form a rubber elastomer. For example, liquid polyisoprene is classified as liquid rubber because it can be cross-linked to form a rubber elastomer.

[0082] The viscosity of the liquid polyolefin resin and the liquid rubber at 25°C is preferably 5 to 5,000 Pa·s, more preferably 10 to 4,000 Pa·s, and even more preferably 20 to 3,000 Pa·s.

[0083] The number average molecular weight of the liquid polyolefin resin is preferably 500 to 40,000, more preferably 750 to 35,000, and even more preferably 1,000 to 30,000. Similarly, the number average molecular weight of the liquid rubber is 500 to 40,000, more preferably 750 to 35,000, and even more preferably 1,000 to 30,000.

[0084] Liquid polyolefin resins and / or liquid rubbers are preferably liquid polybutene. Liquid polybutene can be a homopolymer (e.g., 1-butene homopolymer, isobutene homopolymer) or a copolymer (e.g., a copolymer of 1-butene and isobutene).

[0085] Commercially available liquid polyolefin resins and / or liquid rubbers can be used. Examples of commercially available liquid polyolefin resins include: ENEOS's "HV-300" (liquid polybutene), ENEOS's "HV-1900" (liquid polybutene), ENEOS's "HV-50" (liquid polybutene), ENEOS's "HV-35" (liquid polybutene), Kothari's "950MW" (liquid polybutene), Kothari's "2400MW" (liquid polybutene), and INEOS's "H... Liquid polybutene (LPP-1900), INEOSCO's H-6000, INEOSCO's H-18000, Nippon Oil Company's 200N, Nippon Soda's BI-2000, Nippon Soda's BI-3000, Nippon Soda's GI-3000, Mitsui Chemicals' LUCANT LX100, and Mitsui Chemicals' LUCANT LX400 are among the liquid polybutenes produced.

[0086] Commercially available liquid rubber products include, for example: "Poly bd R-45HT" (butadiene-based liquid rubber) manufactured by Idemitsu Showa Shell Co., Ltd., "Poly bd R-15HT" (butadiene-based liquid rubber) manufactured by Idemitsu Showa Shell Co., Ltd., and "Poly bd R-15HT" (butadiene-based liquid rubber) manufactured by Idemitsu Showa Shell Co., Ltd. Liquid polyisoprene (IP), Nippon Soda's "B-1000" (liquid polybutadiene), Nippon Soda's "B-3000" (liquid polybutadiene), Nippon Soda's "G-3000" (liquid polybutadiene), Kuraray's "LIR-30" (liquid polyisoprene), Kuraray's "LIR-390" (liquid polyisoprene), Kuraray's "LIR-290" (liquid polyisoprene), Kuraray's "LBR-302" (liquid polybutadiene), Kuraray's "LBR-305" (liquid polybutadiene), Kuraray's "LBR-361" (liquid polybutadiene), Kuraray's "L-SBR-820" (liquid styrene-butadiene random copolymer), Crayley VALLEY's "Ricon 154" (liquid butadiene) and Clayville's "RICON 184" (liquid styrene-butadiene random copolymer), etc.

[0087] When using component (C), from the viewpoint of adhesion and flexural strength, its content in the adhesive composition is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, and further preferably 60% by mass or less, relative to 100% by mass of the non-volatile components in the adhesive composition.

[0088] <Other Ingredients> For adhesive compositions, components other than components (A) to (C) (hereinafter sometimes referred to as "other components") may be included to a extent that does not impair the effects of the present invention. Examples of other components include: curing accelerators, adhesion promoters (tackifiers), inorganic or organic fillers, antioxidants, plasticizers, etc. Only one of them may be used, or two or more may be used in combination.

[0089] As other components, curing accelerators are preferred. Examples of curing accelerators include imidazole compounds, tertiary amine / quaternary amine compounds, dimethylurea compounds, and organophosphorus compounds.

[0090] Examples of imidazole compounds include: 1H-imidazolium, 2-methylimidazolium, 2-phenyl-4-methylimidazolium, 2-ethyl-4-methylimidazolium, 1-cyanoethyl-2-ethyl-4-methylimidazolium, 2-undecylimidazolium, 1-cyanoethyl-2-undecylimidazolium, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2-phenyl-4,5-bis(hydroxymethyl)imidazolium, 1-benzyl-2-methylimidazolium, 1-benzyl-2-phenylimidazolium, 2-phenylimidazolium, 2-dodecylimidazolium, 2-heptadecanylimidazolium, 1,2-dimethylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, etc. Specific examples of imidazole compounds include CUREZOL 2MZ, 2P4MZ, 2E4MZ, 2E4MZ-CN, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2PHZ, 1B2MZ, 1B2PZ, 2PZ, C17Z, 1.2DMZ, 2P4MHZ-PW, 2MZ-A, and 2MA-OK (all manufactured by Shikoku Chemical Industry Co., Ltd.).

[0091] There are no particular limitations on the tertiary / quaternary amine compounds, and examples include: quaternary ammonium salts such as tetramethylammonium bromide, tetrabutylammonium bromide, and triethylmethylammonium 2-ethylhexanoate; diazabicyclic compounds such as DBU (1,8-diazabicyclo[5.4.0]undecene-7), DBN (1,5-diazabicyclo[4.3.0]nonene-5), DBU-phenol salts, DBU-octanoate, DBU-p-toluenesulfonate, DBU-formate, and DBU-linear phenolic resin salts; tertiary amines or their salts such as benzyl dimethylamine, 2-(dimethylaminomethyl)phenol, and 2,4,6-tris(dimethylaminomethyl)phenol (TAP); dimethylurea compounds such as aromatic dimethylurea and aliphatic dimethylurea; and so on.

[0092] Examples of dimethylurea compounds include aromatic dimethylureas such as DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and U-CAT3512T (manufactured by San-Apro); and aliphatic dimethylureas such as U-CAT3503N (manufactured by San-Apro). Among these, aromatic dimethylureas are preferred from the perspective of curability.

[0093] Examples of organophosphorus compounds include triphenylphosphine, tetraphenylphosphine tetratolylborate, tetraphenylphosphine tetraphenylborate, tri-tert-butylphosphine tetraphenylborate, (4-methylphenyl)triphenylphosphine thiocyanate, tetraphenylphosphine thiocyanate, butyltriphenylphosphine thiocyanate, and triphenylphosphine triphenylborane. Specific examples of organophosphorus compounds include TPP, TPP-MK, TPP-K, TTPuP-K, TPP-SCN, and TPP-S (all manufactured by Beixing Chemical Industry Co., Ltd.).

[0094] When using a curing accelerator, its content in the adhesive composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, more preferably 2% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, relative to 100% by mass of the non-volatile components of the adhesive composition, in order to promote the formation of component (A) (i.e., crosslinked isobutylene polymer having a long-chain alkyl ester polymer chain of (meth)acrylate), in order to promote the formation of component (A) (i.e., crosslinked isobutylene polymer having a long-chain alkyl ester polymer chain of (meth)acrylate), and even more preferably 0.5% by mass or less. Example

[0095] The present invention will be described in more detail below with examples, but the invention is not limited to these examples. It may also be implemented with appropriate modifications within the scope suitable for the context, and all such modifications are included within the technical scope of the present invention. It should be noted that, unless otherwise specified, the terms "parts" and "%" in the amounts of components and copolymer units refer to "parts by mass" and "% by mass," respectively.

[0096] <Ingredients> The components used in the examples and comparative examples are shown below: (1) The raw material (1-1) of component (A) or component (A') is an isobutylene polymer “ER869” (manufactured by Starlight PMC, glycidyl methacrylate-2-ethylhexyl acrylate random copolymer modified butyl rubber (hereinafter sometimes referred to as “GMA+2-EHA modified IIR”), with the following concentrations: (meth)acrylate long-chain alkyl ester unit: 0.067 mmol / g, epoxy group concentration: 1.51 mmol / g, number average molecular weight: 189,000, isobutylene unit / isoprene unit: 98.9% / 1.1%). “ER872” (manufactured by Starlight PMC, glycidyl methacrylate-laurate methacrylate random copolymer modified butyl rubber (sometimes referred to as “GMA+LMA modified IIR”), concentration of (meth)acrylate long-chain alkyl ester units: 0.067 mmol / g, epoxy group concentration: 1.51 mmol / g, number average molecular weight: 166,000, isobutylene units / isoprene units: 98.9% / 1.1%).

[0097] (1-2) An isobutylene polymer “ER669” (manufactured by Starlight PMC, modified butyl rubber with maleic anhydride-2-ethylhexyl acrylate random copolymer, sometimes referred to as “MA+2-EHA modified IIR”) containing (meth)acrylate long-chain alkyl ester polymer chains and anhydride groups, with a concentration of (meth)acrylate long-chain alkyl ester units: 0.21 mmol / g, anhydride group concentration: 0.43 mmol / g, number average molecular weight: 96,000, and isobutylene units / Isoprene unit: 98.9% / 1.1%) "ER674" (manufactured by Starlight PMC, maleic anhydride-lauryl methacrylate random copolymer modified butyl rubber (hereinafter sometimes referred to as "MA+LMA modified IIR"), concentration of (meth)acrylate long-chain alkyl ester unit: 0.21 mmol / g, anhydride group concentration: 0.43 mmol / g, number average molecular weight: 142,900, isobutylene unit / isoprene unit: 98.9% / 1.1%).

[0098] (1-3) Isobutylene polymers with epoxy or anhydride groups “ER866” (manufactured by Starlight PMC, glycidyl methacrylate modified butyl rubber (sometimes referred to as “GMA modified IIR”), epoxy group concentration: 1.63 mmol / g, number average molecular weight: 113,000, isobutylene units / isoprene units: 98.9% / 1.1%) “ER661” (manufactured by Starlight PMC, maleic anhydride-butyl methacrylate random copolymer modified butyl rubber (sometimes referred to as “MA+BMA modified IIR”), butyl methacrylate unit concentration: 0.32 mmol / g, anhydride group concentration: 0.32 mmol / g, number average molecular weight: 40,000, isobutylene unit / isoprene unit: 98.9% / 1.1%).

[0099] (2)(B) Components "PLENACT AL-M" (manufactured by Ajinomoto Fine-Techno Co., Inc., an aluminum chelate (octadecenyl aluminum diisopropyl acetoacetate)) "ORGATIX ZC-540" (manufactured by Matsumoto Fine Chemical Co., Ltd., a zirconium chelate (zirconium tributoxymonoacetylacetonate)).

[0100] (3)(C) Components “HV-1900” (manufactured by ENEOS, liquid polybutene, number average molecular weight: 2,900, viscosity at 25°C: 460 Pa·s).

[0101] (4) Other ingredients “U CAT18X” (manufactured by San-Apro, a curing accelerator).

[0102] <Example 1> Prepare the varnish according to the mixing ratio shown in the table below by following the steps below, and use the obtained varnish to make adhesive sheets. It should be noted that the amount (parts) of each component listed in the table below indicates the amount of non-volatile components in the varnish.

[0103] Specifically, glycidyl methacrylate-2-ethylhexyl acrylate random copolymer modified butyl rubber (Starlight PMC "ER869"), maleic anhydride-2-ethylhexyl acrylate random copolymer modified butyl rubber (Starlight PMC "ER669"), polybutene (ENEOS "HV-1900"), aluminum chelate (Ajinomoto Fine Chemicals "PLENACT AL-M"), and curing accelerator (San-Apro "U CAT18X") are combined and the resulting mixture is uniformly dispersed using a high-speed rotary mixer to obtain a varnish of the adhesive composition. Using a die coater, the obtained varnish is evenly applied to the release surface of a polyethylene terephthalate (PET) film (ToyoCloth "SP3000", PET film thickness: 38μm) treated with an organosilicon-based release agent. The film is then heated at 130°C for 30 minutes to obtain an adhesive sheet with an adhesive composition layer of 50μm thickness.

[0104] <Example 2> Specifically, the glycidyl methacrylate-2-ethylhexyl acrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER869") was replaced with glycidyl methacrylate-lauryl methacrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER872"), and the maleic anhydride-2-ethylhexyl acrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER669") was replaced with maleic anhydride-lauryl methacrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER674"). Otherwise, using the same method as in Example 1, a varnish of the adhesive composition and an adhesive sheet having an adhesive composition layer with a thickness of 50 μm were prepared.

[0105] <Example 3> The glycidyl methacrylate-2-ethylhexyl acrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER869") was replaced with glycidyl methacrylate modified butyl rubber (manufactured by Starlight PMC, "ER866"). Otherwise, the varnish of the adhesive composition and the adhesive sheet having an adhesive composition layer with a thickness of 50 μm were prepared using the same method as in Example 1.

[0106] <Example 4> The maleic anhydride-2-ethylhexyl acrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER669") was replaced with maleic anhydride-butyl methacrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER661"). Otherwise, the varnish of the adhesive composition and the adhesive sheet having an adhesive composition layer with a thickness of 50 μm were prepared using the same method as in Example 1.

[0107] <Example 5> The aluminum chelate (PLENACT AL-M manufactured by Ajinomoto Fine Chemicals Co., Ltd.) was replaced with a zirconium chelate (ORGATIX ZC-540 manufactured by Matsumoto Fine Chemicals Co., Ltd.). Otherwise, the varnish of the adhesive composition and the adhesive sheet having an adhesive composition layer with a thickness of 50 μm were prepared using the same method as in Example 1.

[0108] <Comparative Example 1> Specifically, the glycidyl methacrylate-2-ethylhexyl acrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER869") was replaced with glycidyl methacrylate modified butyl rubber (manufactured by Starlight PMC, "ER866"), and the maleic anhydride-2-ethylhexyl acrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER669") was replaced with maleic anhydride-butyl methacrylate random copolymer modified butyl rubber (manufactured by Starlight PMC, "ER661"). Otherwise, using the same method as in Example 1, a varnish of the adhesive composition and an adhesive sheet having an adhesive composition layer with a thickness of 50 μm were prepared.

[0109] In this specification, "maleic anhydride-butyl methacrylate random copolymer modified butyl rubber" refers to "butyl rubber having maleic anhydride-butyl methacrylate random copolymer chains as side chains." Furthermore, in this specification, "the crosslinked polymer in the adhesive composition layer of Comparative Example 1, formed from glycidyl methacrylate-2-ethylhexyl acrylate random copolymer modified butyl rubber and maleic anhydride-butyl methacrylate random copolymer modified butyl rubber" is described as "(A') component," "structural units from butyl methacrylate" is described as "butyl methacrylate units," and "polymer chains containing butyl methacrylate units" is described as "butyl methacrylate polymer chains."

[0110] <Comparative Example 2> Aluminum-free chelate (PLENACT AL-M manufactured by Ajinomoto Fine Chemicals Co., Ltd.) was not used. In addition, the varnish of the adhesive composition and the adhesive sheet having an adhesive composition layer with a thickness of 50 μm were prepared using the same method as in Example 1.

[0111] <Methods for evaluating adhesiveness> The adhesive sheet, which uses PET film as the support, was cut into 50mm long and 20mm wide sections. Next, using an intermittent vacuum laminator (Nichigo-Morton "Morton-724"), the adhesive composition layer of the cut adhesive sheet was laminated onto the PET surface of a composite film (Tokai Toyo Aluminum Sales Co., Ltd. "AL1N30 with PET", aluminum foil thickness: 30μm, PET film thickness: 25μm) containing aluminum foil and polyethylene terephthalate (PET) film, thus preparing a laminate with a "composite film / adhesive composition layer / support (PET film)" structure. Lamination was performed at a temperature of 80°C, a time of 30 seconds, and a pressure of 0.3MPa. Peel the support (PET film) from the obtained laminate, and under the same conditions as described above, laminate a polyimide film (UPILEX-S manufactured by Ube Industries, Ltd., thickness: 50 μm) onto the exposed adhesive composition layer to obtain a laminate with a "composite film / adhesive composition layer / polyimide film" structure. For the obtained laminate, at a stretching speed of 300 mm / min along a direction 180 degrees relative to the length direction of the PET film of the composite film, the adhesive strength (room temperature adhesive strength) when the "composite film / adhesive composition layer" is peeled from the polyimide film at room temperature is measured. In addition, the adhesive strength (high temperature adhesive strength) when the laminate prepared in the same manner as described above is peeled at 60°C is measured. The results are shown in Table 1.

[0112] The adhesive properties of the adhesive composition at high temperatures are evaluated according to the following criteria: (Adhesion at high temperatures) ◎(Extremely Good): High-temperature bond strength is above 0.60 kgf / cm. 〇 (Good): High-temperature bond strength is above 0.55 kgf / cm and less than 0.60 kgf / cm. × (Poor): High-temperature bonding strength is less than 0.55 kgf / cm.

[0113] <Evaluation Method for Bending Resistance> The adhesive sheet was folded, and the folded adhesive sheet was punched with an 8mm diameter belt punch to prepare an evaluation sample with a thickness of approximately 1.0mm and a diameter of 8mm. The evaluation sample was placed on a DHR parallel plate rheometer, and the shear strain rate S1 of the evaluation sample was measured at a time point after being subjected to a shear stress of 95kPa for 5 seconds. Next, the shear strain rate S2 of the evaluation sample was measured at a time point after the stress was removed for 60 seconds.

[0114] The strain recovery rate is calculated using the following formula: The shear strain rate S1 of the evaluation sample subjected to a shear stress of 95 kPa for 5 seconds, and the shear strain rate S2 of the evaluation sample after the stress has been removed for 60 seconds. Strain recovery rate (%) = 100 × (S1 - S2) / S1.

[0115] For laminates containing adhesive composition layers with good strain recovery, peeling or lifting is prevented even when bent. Therefore, the flexural resistance was evaluated using the strain recovery rate according to the following criteria. The results are shown in Table 1; (Bending resistance) ◎(Extremely Good): Strain recovery rate is over 95% 〇 (Good): Strain recovery rate is above 90% and less than 95%. × (Defective): Strain recovery rate less than 90%.

[0116] [Table 1]

[0117] The adhesive compositions of Examples 1 to 5, which contain a crosslinked isobutylene polymer having a (meth)acrylate long-chain alkyl ester polymer chain (component (A)) and a chelate of aluminum or zirconium (component (B)), exhibit excellent adhesion (high-temperature adhesive strength) and flexural strength (strain recovery rate) at high temperatures.

[0118] On the other hand, the adhesive composition of Comparative Example 1, which contains component (A') having a butyl methacrylate polymer chain instead of component (A), exhibits poor adhesion at high temperatures. Furthermore, the adhesive composition of Comparative Example 2, which does not contain component (B), exhibits poor flexural strength.

[0119] Industrial availability The adhesive composition and adhesive sheet of the present invention are useful for the manufacture of flexible electronic devices (especially for the manufacture of laminates constituting flexible devices).

[0120] This application is based on Japanese Patent Application No. 2020-204467, which was filed in Japan and contains the entire contents of this application specification.

Claims

1. An adhesive composition, wherein, Include: (A) An isobutylene polymer having a cross-linked structure formed by the reaction of epoxy groups with acid anhydride groups and / or carboxyl groups; and (B) Selected from at least one of alkoxides with a metal of valence of 2 or higher as the central metal, carboxylates with a metal of valence of 2 or higher as the central metal, and chelates with a metal of valence of 2 or higher as the central metal. The isobutylene-based polymer has polymer chains as side chains, and the polymer chains contain structural units derived from alkyl (meth)acrylates having alkyl groups having 6 or more carbon atoms. The content of component (A) is 10% by mass or more and 90% by mass or less, relative to 100% by mass of the non-volatile components of the adhesive composition. The content of component (B) is 0.5% by mass or more and 15% by mass or less, relative to 100% by mass of the non-volatile components of the adhesive composition.

2. The adhesive composition according to claim 1, wherein, The concentration of structural units derived from alkyl (meth)acrylates having 6 or more carbon atoms in the isobutylene polymer is 0.005–5 mmol / g.

3. The adhesive composition according to claim 1, wherein, The isobutylene polymer is selected from at least one of (a1) and (a2) below: (a1) The reaction product of an isobutylene-isoprene copolymer having epoxy groups and an olefin polymer having anhydride groups and / or carboxyl groups. (a2) The reaction product of isobutylene-isoprene copolymers having anhydride and / or carboxyl groups with olefin polymers having epoxy groups. Furthermore, at least one of the isobutylene-isoprene copolymer and the olefin polymer has a polymer chain as a side chain, the polymer chain comprising structural units derived from alkyl (meth)acrylates having an alkyl group having 6 or more carbon atoms.

4. The adhesive composition according to claim 1, wherein, The isobutylene polymer is selected from at least one of (a3), (a4) and (a5) below: (a3) The reaction product of an isobutylene-isoprene copolymer having epoxy groups and polymer chains comprising structural units derived from alkyl (meth)acrylates having alkyl groups having six or more carbon atoms as side chains, and an olefin polymer having an anhydride group and / or a carboxyl group. (a4) Isobutylene-isoprene copolymers having an anhydride group and / or a carboxyl group and a polymer chain comprising a structural unit derived from an alkyl (meth)acrylate having 6 or more carbon atoms as a side chain, reaction products with olefin polymers having epoxy groups, and (a5) The reaction product of an isobutylene-isoprene copolymer having an epoxy group and a structural unit comprising a (meth)acrylate alkyl ester having an alkyl group having six or more carbon atoms as a side chain, and an isobutylene-isoprene copolymer having an anhydride group and / or a carboxyl group and a polymer chain comprising a (meth)acrylate alkyl ester having an alkyl group having six or more carbon atoms as a side chain.

5. The adhesive composition according to claim 3 or 4, wherein, The olefin polymer is an isobutylene polymer.

6. The adhesive composition according to claim 3 or 4, wherein, The olefin polymer is an isobutylene-isoprene copolymer.

7. The adhesive composition according to claim 1, wherein, Metals with a valence of 2 or higher are either metals in Group IVB or Group IIIA of the periodic table.

8. The adhesive composition according to claim 1, wherein, Metals with a valence of divalent or higher are aluminum, titanium, or zirconium.

9. The adhesive composition according to claim 1, wherein, (B) is a chelate with a metal of valence of 2 or higher as the center metal.

10. The adhesive composition according to claim 1, wherein, (B) is a metal complex as shown in formula (1) below. In equation (1), M indicates a metal with a valence of divalent or higher. R1 and R3 each independently represent a hydrogen atom, alkyl, alkenyl, alkoxy, alkenyloxy, aryl, or aralkyl. R2 represents a hydrogen atom, alkyl, alkenyl, alkoxy, alkenyloxy, alkoxycarbonyl, aryl, or aralkyl. X represents a monodentate ligand. In equation (1), the solid line between the oxygen atom (O) in [ ] and M represents a covalent bond. In equation (1), the dashed line between the oxygen atom (O) in [ ] and M represents a coordinate bond, and m represents 3 or 4, n represents an integer from 0 to 4, and m ≥ n.

11. The adhesive composition according to claim 10, wherein, M is aluminum, titanium, or zirconium. One of R1 and R3 is an alkyl, alkoxy, or alkenyloxy group, and the remaining one is an alkyl group. R2 is a hydrogen atom. X is an alkoxide anion or a carboxylate anion, and m is 3 or 4, n is an integer from 1 to 3, and m > n.

12. The adhesive composition according to claim 10 or 11, wherein, M represents aluminum or zirconium.

13. The adhesive composition according to claim 1, wherein, It further includes (C) liquid polyolefin resin and / or liquid rubber.

14. An adhesive sheet having a laminated structure, The stacked structure includes: The adhesive composition layer formed by the adhesive composition according to any one of claims 1 to 13, and Support body.

15. The adhesive sheet according to claim 14, wherein, Used in the manufacture of flexible electronic devices.

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