Adhesive composition and laminate with adhesive layer

Abstract

The present invention provides an adhesive composition that can suppress deformation of the substrate of a laminate with an adhesive layer, ensure alignment between the laminate with an adhesive layer and the adherend, and ensure adhesion, as well as a laminate with an adhesive layer using the same. [Solution] The adhesive composition contains a modified styrene elastomer (A) having reactive functional groups that react with epoxy groups, an epoxy resin (B), and at least one selected from the group consisting of an unmodified styrene elastomer (C) and a lubricant (D). The adhesive composition contains, per 100 parts by mass of the modified styrene elastomer (A), 0 to less than 5 parts by mass of the unmodified styrene elastomer (C) and 0.05 to 12 parts by mass of the lubricant (D), or per 100 parts by mass of the modified styrene elastomer (A), 5 or more parts by mass of the unmodified styrene elastomer (C) and 0 to 12 parts by mass of the lubricant (D).

Description

Technical Field

[0001] The present invention relates to an adhesive composition and a laminate with an adhesive layer.

Background Art

[0002] Conventionally, adhesive compositions have been used in various fields. For example, in a printed wiring board used in the field of electronic devices, an adhesive composition is used when adhering a base material and a copper foil or the like.

[0003] In addition, a laminate with an adhesive layer in which an adhesive composition is layer-coated on a desired base material made of a resin film or the like to form an adhesive layer is also known. For example, when manufacturing a printed wiring board such as a flexible printed wiring board (hereinafter sometimes referred to as "FPC"), this type of laminate with an adhesive layer is used, and bonding with a target adherend is performed through the adhesive layer.

[0004] Prior Patent Document 1 discloses a technique related to an adhesive composition used for FPC. Specifically, Patent Document 1 describes an adhesive composition containing an acid-modified polystyrene elastomer resin (A), a carbodiimide resin (B), and an epoxy resin (C), and having a solution viscosity ratio (solution viscosity ηB / solution viscosity ηB0) of a toluene solution (solid content concentration 20% by mass) of the acid-modified polystyrene elastomer resin (A) of 0.5 or more and less than 3.0. Further, Patent Document 1 also describes that the content of the carbodiimide resin (B) is 0.1 to 30 parts by mass with respect to 100 parts by mass of the acid-modified polystyrene elastomer resin (A), the content of the epoxy resin (C) is 1 to 30 parts by mass with respect to 100 parts by mass of the acid-modified polystyrene elastomer resin (A), and the content of the acid-modified polyolefin resin is 20 parts by mass or less with respect to 100 parts by mass of the acid-modified polystyrene elastomer resin (A), among other points.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] When bonding the aforementioned laminate with adhesive layer to a target substrate via the adhesive layer, if misalignment occurs, it is desirable that the laminate with adhesive layer be able to be slid laterally on the substrate to readjust its position and re-bond. Even if the laminate with adhesive layer cannot be slid laterally, it is necessary that the laminate with adhesive layer be able to be peeled off the substrate, readjusted, and re-bonded. Thus, it is important that the adhesive composition and the laminate with adhesive layer not only ensure adhesion, but also have the characteristic (hereinafter sometimes referred to as alignment ability) that the laminate with adhesive layer bonded to the substrate can be slid laterally, or peeled off if it cannot be slid laterally. Furthermore, deformation of the substrate of the laminate with adhesive layer must be suppressed during this alignment process.

[0007] However, conventional adhesive compositions have the problem of difficulty in ensuring proper alignment between the adhesive-coated laminate and the adherend, and the substrate can deform when forcibly peeled off.

[0008] The present invention has been made in view of the above problems, and aims to provide an adhesive composition that can suppress deformation of the substrate of the laminate with an adhesive layer, ensure alignment between the laminate with an adhesive layer and the adherend, and ensure adhesion, as well as a laminate with an adhesive layer using the same. [Means for solving the problem]

[0009] The adhesive composition and laminate with adhesive layer according to the present invention are as follows: [1] A modified styrene elastomer (A) having a reactive functional group that reacts with epoxy groups, Epoxy resin (B) and, An adhesive composition comprising at least one selected from the group consisting of an unmodified styrene elastomer (C) and a lubricant (D), Amount to 100 parts by mass of the modified styrene elastomer (A): The unmodified styrene-based elastomer (C) is contained in an amount of 0 parts by mass or more but less than 5 parts by mass, and the lubricant (D) is contained in an amount of 0.05 parts by mass or more but less than 12 parts by mass, or Amount to 100 parts by mass of the modified styrene elastomer (A): The product contains 5 parts by mass or more of the unmodified styrene elastomer (C) and 0 parts by mass or more and 12 parts by mass or less of the lubricant (D). Adhesive composition. [2] The modified styrene elastomer (A) is a carboxyl group-containing styrene elastomer. The adhesive composition described in [1]. [3] The aforementioned unmodified styrene-based elastomer (C) is At least one selected from the group consisting of styrene-butadiene block copolymer, styrene-ethylenepropylene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylenebutylene-styrene block copolymer, styrene-ethylenepropylene-styrene block copolymer, and styrene-(ethylene-ethylene / propylene)-styrene block copolymer. The adhesive composition described in [1] or [2]. [4] The lubricant (D) is At least one selected from the group consisting of fatty acid esters, fatty acid amides, fatty acids, fatty acid metal salts, and waxes. An adhesive composition according to any one of [1] to [3]. [5] The adhesive comprises an adhesive layer formed from any one of the adhesive compositions described in [1] to [4], and a base film in contact with at least one surface of the adhesive layer, The adhesive layer is in a B-stage state. A laminate with an adhesive layer.

Advantages of the Invention

[0010] The above adhesive composition has the above configuration. Therefore, when the adhesive composition is used for the adhesive layer of a laminate with an adhesive layer, it can suppress deformation of the base material of the laminate with an adhesive layer while ensuring the alignment property between the laminate with an adhesive layer and the adherend, and can ensure adhesiveness.

[0011] Further, the laminate with an adhesive layer includes an adhesive layer formed from the above adhesive composition. Therefore, the laminate with an adhesive layer can suppress deformation of the base material of the laminate with an adhesive layer while ensuring the alignment property between the laminate with an adhesive layer and the adherend, and can ensure adhesiveness.

Modes for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited to the examples according to the following embodiments. Also, the lower limit value and the upper limit value of the numerical range shown below can be arbitrarily combined (hereinafter, omitted).

[0013] 1. Adhesive composition The adhesive composition of the present embodiment contains a modified styrene-based elastomer (A), an epoxy resin (B), and at least one selected from the group consisting of an unmodified styrene-based elastomer (C) and a lubricant (D). Hereinafter, the composition of the adhesive composition will be specifically described.

[0014] 1.1 Modified styrene-based elastomer (A) In the adhesive composition of the present embodiment, the modified styrene-based elastomer (A) is an important adhesive component as the base of the adhesive composition.

[0015] The modified styrene-based elastomer (A) has a reactive functional group that reacts with an epoxy group. That is, the modified styrene-based elastomer (A) can be said to be an unmodified styrene-based elastomer with a reactive functional group that reacts with an epoxy group introduced therein, or it can also be said to be an unmodified styrene-based elastomer modified with a modifier having a reactive functional group that reacts with an epoxy group. Furthermore, it can also be said to be an unmodified styrene-based elastomer modified so as to have reactivity with an epoxy resin (B).

[0016] Examples of the reactive functional group that reacts with an epoxy group include a group having active hydrogen, an active ester group, etc. Examples of the group having active hydrogen include a carboxy group, an amino group, a hydroxyl group, an acid anhydride group, a thiol group, etc. These can be used alone or in combination of two or more. From the viewpoint of reactivity etc., the reactive functional group that reacts with an epoxy group is preferably a carboxy group or an amino group, and more preferably a carboxy group. When the reactive functional group is a carboxy group, the modified styrene-based elastomer (A) is referred to as a carboxy group-containing styrene-based elastomer (the same applies to others).

[0017] The modified styrene-based elastomer (A) can have a structural part derived from an unmodified styrene-based elastomer and a structural part derived from a modifier having a reactive functional group that reacts with an epoxy group. The modified styrene-based elastomer (A) is preferably an acid-modified styrene-based elastomer. Specifically, it is preferably a graft-modified product of an unmodified styrene-based elastomer with a modifier containing an α,β-unsaturated carboxylic acid or its derivative. In this case, more specifically, the modified styrene-based elastomer (A) can have a structural part derived from an unmodified styrene-based elastomer and a structural part derived from an α,β-unsaturated carboxylic acid or its derivative.

[0018] Examples of unmodified styrene-based elastomers used to constitute the modified styrene-based elastomer (A) include styrene-butadiene block copolymer (SB), styrene-ethylenepropylene block copolymer (SEP), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylenebutylene-styrene block copolymer (SEBS), styrene-ethylenepropylene-styrene block copolymer (SEPS), and styrene-(ethylene-ethylene / propylene)-styrene block copolymer (SEEPS). These can be used individually or in combination of two or more. Of these, styrene-ethylenebutylene-styrene block copolymer (SEBS) is preferred from the viewpoint of adhesion and other factors.

[0019] The styrene content in the unmodified styrene elastomer used to constitute the modified styrene elastomer (A) is preferably 35% by mass or more, more preferably 37.5% by mass or more, and even more preferably 40% by mass or more, from the viewpoint of ensuring proper alignment when bonding the B-stage adhesive layers. Furthermore, the above styrene content is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less, from the viewpoint of ensuring proper adhesion when bonding the B-stage adhesive layers. Note that the styrene content is the mass ratio (percentage) of styrene units in the unmodified styrene elastomer, and can be calculated specifically using the formula 100 × (mass of styrene units in the unmodified styrene elastomer) / (mass of the unmodified styrene elastomer).

[0020] The modified styrene elastomer (A) can be produced by known methods, and a radical initiator may be used during production. Examples of methods for producing the modified styrene elastomer (A) include a solution method in which the desired unmodified styrene elastomer described above is heated and dissolved in a solvent such as toluene, and the modifier and radical initiator are added, and a melt method in which the desired unmodified styrene elastomer, modifier, and radical initiator are melt-kneaded using a Banbury mixer, kneader, extruder, etc. The method of using the desired unmodified styrene elastomer, modifier, and radical initiator described above is not particularly limited, and they may be added to the reaction system all at once or sequentially. Furthermore, when producing the modified styrene elastomer (A), a modification aid to improve graft efficiency using a modifying agent such as α,β-unsaturated carboxylic acid, a stabilizer to adjust resin stability, etc., can be used.

[0021] The modifying agent may include α,β-unsaturated carboxylic acids and their derivatives. Examples of α,β-unsaturated carboxylic acids include maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, aconitic acid, norbornenedicarboxylic acid, etc. Examples of derivatives of unsaturated carboxylic acids include acid anhydrides, acid halides, amides, imides, esters, etc. Among the above modifying agents, itaconic anhydride, maleic anhydride, aconitic anhydride, and citraconic anhydride are preferred, with itaconic anhydride and maleic anhydride being particularly preferred in terms of adhesion. When using a modifying agent, it is sufficient to use one or more selected from α,β-unsaturated carboxylic acids and their derivatives, and this can be a combination of one or more α,β-unsaturated carboxylic acids and one or more derivatives, a combination of two or more α,β-unsaturated carboxylic acids, or a combination of two or more derivatives of α,β-unsaturated carboxylic acids, etc.

[0022] 1.2 Epoxy resin (B) In the adhesive composition of this embodiment, the epoxy resin (B) reacts with the reactive functional groups of the modified styrene elastomer (A) and is an important component for exhibiting adhesion to the adherend and heat resistance of the cured adhesive composition.

[0023] Examples of epoxy resins (B) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, or hydrogenated versions thereof; glycidyl ester epoxy resins such as diglycidyl orthophthalate, diglycidyl isophthalate, diglycidyl terephthalate, glycidyl p-hydroxybenzoate, diglycidyl tetrahydrophthalate, diglycidyl succinate, diglycidyl adipicate, diglycidyl sebacate, and triglycidyl trimelliticate; ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and 1,4-butane. Examples of epoxy resins include glycidyl ether-based epoxy resins such as diol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, tetraphenyl glycidyl ether ethane, triphenyl glycidyl ether ethane, sorbitol polyglycidyl ether, and polyglycerol polyglycidyl ether; glycidylamine-based epoxy resins such as triglycidyl isocyanurate and tetraglycidyldiaminodiphenylmethane; and linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil, but are not limited to these. Novolac-type epoxy resins such as phenol novolac epoxy resin, o-cresol novolac epoxy resin, and bisphenol A novolac epoxy resin can also be used.

[0024] Furthermore, examples of epoxy resin (B) include brominated bisphenol A type epoxy resin, phosphorus-containing epoxy resin, epoxy resin having a dicyclopentadiene skeleton, epoxy resin having a naphthalene skeleton, anthracene type epoxy resin, tert-butylcatechol type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, biphenyl type epoxy resin, bisphenol S type epoxy resin, and the like. These epoxy resins (B) may be used individually or in combination of two or more.

[0025] As for the epoxy resin (B), one having two or more epoxy groups in a single molecule is preferable. This is because it can form a cross-linked structure through reaction with the modified styrene elastomer (A), thereby exhibiting high heat resistance.

[0026] As for epoxy resin (B), polyfunctional epoxy resins having an alicyclic skeleton, epoxy resins having a polycyclic aromatic hydrocarbon skeleton, etc., are preferred from the viewpoint of easily ensuring sufficient adhesive strength. These can be used individually or in combination of two or more types.

[0027] 1.3 Unmodified styrene-based elastomer (C) Unmodified styrene elastomer (C) is a useful component for suppressing surface stickiness and surface tackiness by giving the adhesive composition and adhesive layer an appropriate hardness when the adhesive composition and adhesive layer are in the B-stage state. The B-stage state of the adhesive composition and adhesive layer refers to a semi-cured state in which a part of the adhesive composition has begun to harden, and further hardening of the adhesive composition will proceed due to heating or other means.

[0028] Examples of unmodified styrene-based elastomers (C) include styrene-butadiene block copolymer (SB), styrene-ethylenepropylene block copolymer (SEP), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylenebutylene-styrene block copolymer (SEBS), styrene-ethylenepropylene-styrene block copolymer (SEPS), and styrene-(ethylene-ethylene / propylene)-styrene block copolymer (SEEPS). These can be used individually or in combination of two or more. Of these, styrene-ethylenebutylene-styrene block copolymer (SEBS) is preferred from the viewpoint of heat resistance and other factors.

[0029] The unmodified styrene elastomer (C) and the unmodified styrene elastomer used to constitute the modified styrene elastomer (A) described above may be the same or different.

[0030] The styrene content of the unmodified styrene-based elastomer (C) is preferably 35% by mass or more, more preferably 37.5% by mass or more, and even more preferably 40% by mass or more, from the viewpoint of ensuring proper alignment when bonding the B-stage adhesive layers. Furthermore, the styrene content is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less, from the viewpoint of ensuring proper adhesion when bonding the B-stage adhesive layers. The definition of the styrene content is the same as the definition described above.

[0031] 1.4 Lubricant (D) Lubricant (D) is a useful component for suppressing surface tackiness of the adhesive composition and adhesive layer by forming a lubricant layer on the surface of the adhesive composition and adhesive layer when the adhesive composition and adhesive layer are in a B-stage state. The lubricant layer formed on the surface of the adhesive layer disintegrates due to heat applied during the lamination process (such as heat applied during bonding) when the laminate with the adhesive layer is laminated, which is useful for ensuring adhesion to the adherend and exhibiting sufficient adhesion.

[0032] Examples of lubricants (D) include fatty acid esters, fatty acid amides, fatty acids, fatty acid metal salts, and waxes. These can be used individually or in combination of two or more.

[0033] Examples of fatty acid esters include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, and dipentaerythritol hexastearate. These can be used individually or in combination of two or more. Examples of fatty acid amides include aliphatic monocarboxylic acid amides such as lauric acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, erucic acid amide, behenic acid amide, ricinoleic acid amide, and hydroxystearic acid amide; N-substituted aliphatic monocarboxylic acid amides such as N-oleyloleic acid amide, N-oleylstearic acid amide, and N-stearyloleic acid amide; aliphatic biscarboxylic acid amides such as methylenebisstearate and ethylenebisstearate; N,N'-ethylene-bis-oleyl amide; N,N'-ethylenebisstearate amide; and N,N'-methylenebisstearate amide. These can be used individually or in combination of two or more. Examples of fatty acids include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, arachidic acid, cerotic acid, montanic acid, and melissic acid, as well as unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, elaidic acid, octadecenoic acid, arachidonic acid, cadreic acid, erucic acid, and parinalic acid. These can be used individually or in combination of two or more. Examples of fatty acid metal salts include calcium stearate, magnesium stearate, barium stearate, zinc stearate, aluminum stearate, lithium stearate, calcium lauryl latate, magnesium lauryl latate, barium lauryl latate, zinc lauryl latate, aluminum lauryl latate, and lithium lauryl latate. These can be used individually or in combination of two or more. Examples of natural waxes include montan wax and carnauba wax. Examples of hydrocarbon waxes include paraffin wax, microcrystalline wax, polyethylene wax, and oxidized polyethylene wax. These can be used individually or in combination of two or more.

[0034] 1.5 Ingredient content 1.5.1 Content of modified styrene elastomer (A) In the adhesive composition of this embodiment, the content of modified styrene elastomer (A) is preferably 30 parts by mass or more per 100 parts by mass of solid content of the adhesive composition. In this disclosure, "solid content" means components excluding solvents. By having a content of modified styrene elastomer (A) of 30 parts by mass or more per 100 parts by mass of solid content of the adhesive composition, it is possible to ensure the alignment and adhesion of the laminate with the adhesive layer to the adherend.

[0035] From the viewpoint of adhesion to the adherend, the content of modified styrene elastomer (A) is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, even more preferably 60 parts by mass or more, and particularly preferably 65% ​​by mass or more, per 100 parts by mass of solid content of the adhesive composition. Furthermore, from the viewpoint of adhesion to the adherend, the content of modified styrene elastomer (A) is preferably 99 parts by mass or less, more preferably 98 parts by mass or less, even more preferably 97 parts by mass or less, and particularly preferably 95 parts by mass or less, per 100 parts by mass of solid content of the adhesive composition.

[0036] 1.5.2 Epoxy resin (B) content In the adhesive composition of this embodiment, the content of epoxy resin (B) is preferably 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of modified styrene elastomer (A). A content of 1 part by mass or more of epoxy resin (B) per 100 parts by mass of modified styrene elastomer (A) increases the reactivity with the reactive groups in the modified styrene elastomer (A), making it easier to improve adhesive strength. On the other hand, a content of 20 parts by mass or less of epoxy resin (B) per 100 parts by mass of modified styrene elastomer (A) allows sufficient adhesive strength to be achieved with a relatively short heat treatment time.

[0037] From the viewpoint of exhibiting sufficient adhesion, the content of epoxy resin (B) is preferably 1.5 parts by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of modified styrene elastomer (A). Furthermore, from the viewpoint of exhibiting sufficient adhesion and heat resistance, as well as peel strength and electrical properties, the content of epoxy resin (B) is preferably 19 parts by mass or less, more preferably 18 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of modified styrene elastomer (A).

[0038] 1.5.3 Content of unmodified styrene elastomer (C) and lubricant (D) As described above, the adhesive composition of this embodiment contains at least one selected from the group consisting of an unmodified styrene elastomer (C) and a lubricant (D). In other words, as can be understood from the above description, the adhesive composition of this embodiment may contain both the unmodified styrene elastomer (C) and the lubricant (D), may not contain the lubricant (D) and contain only the unmodified styrene elastomer (C), or may not contain the unmodified styrene elastomer (C) and contain only the lubricant (D).

[0039] In the adhesive composition of this embodiment, the absence of unmodified styrene elastomer (C) may be expressed as containing 0 parts by mass of unmodified styrene elastomer (C). Similarly, the absence of lubricant (D) may be expressed as containing 0 parts by mass of lubricant (D).

[0040] The adhesive composition of this embodiment contains, per 100 parts by mass of modified styrene elastomer (A), 0 parts by mass or more and less than 5 parts by mass of unmodified styrene elastomer (C), and 0.05 parts by mass or more and 12 parts by mass of lubricant (D) (hereinafter, this may be referred to as content requirement I), or per 100 parts by mass of modified styrene elastomer (A), it contains 5 parts by mass or more of unmodified styrene elastomer (C), and 0 parts by mass or more and 12 parts by mass of lubricant (D) (hereinafter, this may be referred to as content requirement II).

[0041] By satisfying content requirement I, the aggregation of the lubricant (D) can be suppressed, and the anti-blocking effect of the adhesive layer surface can improve the alignment of the laminated adhesive layer on the adherend.

[0042] In content requirement I, it is possible not to include unmodified styrene elastomer (C) (content of unmodified styrene elastomer (C) is 0 parts by mass), but if unmodified styrene elastomer (C) is included, the content of unmodified styrene elastomer (C) is preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more, per 100 parts by mass of modified styrene elastomer (A), from the viewpoint of alignment between the laminate with adhesive layer and the adherend.

[0043] Furthermore, in content requirement I, the content of lubricant (D) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of modified styrene elastomer (A), from the viewpoint of alignment between the laminate with the adhesive layer and the adherend, and suppression of deformation of the substrate of the laminate with the adhesive layer. Furthermore, in content requirement I, the content of lubricant (D) is preferably 12 parts by mass or less, more preferably 11 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of modified styrene elastomer (A), from the viewpoint of suppressing aggregation of the lubricant.

[0044] On the other hand, in Content Requirement II, the content of unmodified styrene elastomer (C) is preferably 5 parts by mass or more, more preferably 6 parts by mass or more, and even more preferably 7 parts by mass or more, per 100 parts by mass of modified styrene elastomer (A), from the viewpoint of alignment between the laminate with the adhesive layer and the adherend. Furthermore, in Content Requirement II, the content of unmodified styrene elastomer (C) is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, even more preferably 100 parts by mass or less, and particularly preferably 60 parts by mass or less, per 100 parts by mass of modified styrene elastomer (A), from the viewpoint of adhesion.

[0045] Furthermore, in Content Requirement II, the content of lubricant (D) is preferably 12 parts by mass or less, more preferably 11 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of modified styrene elastomer (A), from the viewpoint of suppressing lubricant aggregation, etc. Also, in Content Requirement II, lubricant (D) may not be included (content of lubricant (D) is 0 parts by mass), but if lubricant (D) is included, the content of lubricant (D) is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of modified styrene elastomer (A), from the viewpoint of alignment between the laminate with adhesive layer and the adherend, and suppression of deformation of the substrate of the laminate with adhesive layer, etc.

[0046] 1.6 Other Ingredients The adhesive composition of this embodiment may contain, in addition to at least one selected from the group consisting of the modified styrene elastomer (A), epoxy resin (B), and unmodified styrene elastomer (C) and lubricant (D) described above, an unmodified thermoplastic resin, tackifier, flame retardant, curing agent, curing accelerator, coupling agent, heat aging inhibitor, inorganic filler, leveling agent, defoaming agent, pigment, UV absorber, and solvent, to an extent that does not affect the function of the adhesive composition.

[0047] (Unmodified thermoplastic resin) Other unmodified thermoplastic resins that can be included in the adhesive composition as resin components include, for example, polyolefin resins, phenoxy resins, polyamide resins, polyester resins, polycarbonate resins, polyphenylene oxide resins, polyurethane resins, polyacetal resins, and polyvinyl resins. These unmodified thermoplastic resins may be used individually or in combination of two or more.

[0048] The above-mentioned polyolefin resin is not particularly limited as long as it has structural units derived from olefins, for example, but homopolymers or copolymers having 2 to 20 carbon atoms such as ethylene, propylene, butene, pentene, hexene, heptene, octene, and 4-methyl-1-pentene are preferably used. The above-mentioned polyolefin resin is more preferably a homopolymer or copolymer of an olefin having 2 to 6 carbon atoms. Specific examples of the above-mentioned polyolefin resin include ethylene-propylene copolymer, propylene-butene copolymer, and ethylene-propylene-butene copolymer. These can be used individually or in combination of two or more.

[0049] (Adhesion agent) Examples of the tackifiers mentioned above include coumarone-indene resin, terpene resin, terpene-phenol resin, rosin resin, pt-butylphenol-acetylene resin, phenol-formaldehyde resin, xylene-formaldehyde resin, petroleum hydrocarbon resin, hydrogenated hydrocarbon resin, turpentine resin, and the like. These tackifiers may be used individually or in combination of two or more.

[0050] (Flame retardant) The above-mentioned flame retardant may be either an organic flame retardant or an inorganic flame retardant. Examples of organic flame retardants include phosphorus-based flame retardants such as melamine phosphate, melamine polyphosphate, guanidine phosphate, guanidine polyphosphate, ammonium phosphate, ammonium polyphosphate, ammonium phosphate, ammonium polyphosphate, carbamate phosphate, carbamate polyphosphate, aluminum tris-diethylphosphinate, aluminum tris-methylethylphosphinate, aluminum tris-diphenylphosphinate, zinc bis-diethylphosphinate, zinc bis-methylethylphosphinate, zinc bis-diphenylphosphinate, titanyl bis-diethylphosphinate, titanium tetrakis-diethylphosphinate, titanyl bis-methylethylphosphinate, titanium tetrakis-methylethylphosphinate, titanyl bis-diphenylphosphinate, and titanium tetrakis-diphenylphosphinate; nitrogen-based flame retardants such as triazine compounds like melamine, melam, and melamine cyanurate, as well as cyanuric acid compounds, isocyanuric acid compounds, triazole compounds, tetrazole compounds, diazo compounds, and urea; and silicon-based flame retardants such as silicone compounds and silane compounds. Examples of inorganic flame retardants include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, barium hydroxide, and calcium hydroxide; metal oxides such as tin oxide, aluminum oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, and nickel oxide; and zinc carbonate, magnesium carbonate, barium carbonate, zinc borate, and hydrated glass. These flame retardants may be used individually or in combination of two or more types.

[0051] (Hardening agent) Examples of the curing agents mentioned above include, but are not limited to, amine-based curing agents and acid anhydride-based curing agents. Examples of amine-based curing agents include melamine resins such as methylated melamine resin, butylated melamine resin, and benzoguanamine resin, as well as dicyandiamide and 4,4'-diphenyldiaminosulfone. Examples of acid anhydrides include aromatic acid anhydrides and aliphatic acid anhydrides. These curing agents may be used individually or in combination of two or more.

[0052] (Curing accelerator) The curing accelerator can be used to accelerate the reaction between a modified styrene elastomer (A), which has reactive functional groups that react with epoxy groups introduced into the resin components, and an epoxy resin (B). Tertiary amine curing accelerators, tertiary amine salt curing accelerators, and imidazole curing accelerators can be used.

[0053] Examples of tertiary amine-based curing accelerators include benzyldimethylamine, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, tetramethylguanidine, triethanolamine, N,N'-dimethylpiperazine, triethylenediamine, and 1,8-diazabicyclo[5.4.0]undecene.

[0054] Examples of tertiary amine salt-based curing accelerators include formate, octylate, p-toluenesulfonate, o-phthalate, phenol salt, or phenol novolac resin salt of 1,8-diazabicyclo[5.4.0]undecene, and formate, octylate, p-toluenesulfonate, o-phthalate, phenol salt, or phenol novolac resin salt of 1,5-diazabicyclo[4.3.0]nonene.

[0055] Imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-methyl-4-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]ethyl-s-triazine, and 2,4-diamino-6-[2' Examples include undecylimidazolyl-(1') ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')] ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')] ethyl-s-triazine isocyanurate adduct, 2-phenylimidazole isocyanurate adduct, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole. These curing accelerators may be used alone or in combination of two or more.

[0056] The content of the curing accelerator is preferably 1 to 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 5 parts by mass, per 100 parts by mass of epoxy resin (B). If the content of the curing accelerator is within the above range, excellent adhesion and heat resistance can be achieved.

[0057] (Coupling agent) Examples of the coupling agents mentioned above include silane-based coupling agents such as vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatetopropyltriethoxysilane, and imidazolesilane; titanate-based coupling agents; aluminate-based coupling agents; and zirconium-based coupling agents. These may be used individually or in combination of two or more.

[0058] (Heat aging inhibitor) Examples of the above-mentioned heat aging inhibitors include antioxidants, specifically 2,6-di-tert-butyl-4-methylphenol, n-octadecyl-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate, tetrakis[methylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane, pentaerythritol, tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl, triethyl] Examples include phenolic antioxidants such as lenglycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate; sulfur-based antioxidants such as dilauryl-3,3'-thiodipropionate and dimyristyl-3,3'-dithiopropionate; and phosphorus-based antioxidants such as trisnonylphenyl phosphite and tris(2,4-di-tert-butylphenyl)phosphite. These may be used individually or in combination of two or more.

[0059] (Inorganic fillers) Examples of the inorganic fillers mentioned above include powders consisting of titanium dioxide, aluminum oxide, zinc oxide, carbon black, silica, talc, copper, and silver. These may be used individually or in combination of two or more.

[0060] (solvent) The adhesive composition of this embodiment can be manufactured by mixing at least one selected from the group consisting of a modified styrene elastomer (A), an epoxy resin (B), and an unmodified styrene elastomer (C) and a lubricant (D), and optionally other components. The mixing method is not particularly limited, as long as the adhesive composition becomes uniform. Since the adhesive composition is preferably used in solution or dispersion form, a solvent such as an organic solvent is usually also used.

[0061] Examples of solvents include alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, isobutyl alcohol, n-butyl alcohol, benzyl alcohol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, and diacetone alcohol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclohexanone, and isophorone; aromatic hydrocarbons such as toluene, xylene, ethylbenzene, and mesitylene; esters such as methyl acetate, ethyl acetate, ethylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate; and aliphatic hydrocarbons such as hexane, heptane, cyclohexane, and methylcyclohexane. These solvents may be used individually or in combination of two or more. When the adhesive composition contains a solvent and each component is dissolved or dispersed in the solvent in a solution or dispersion (resin varnish), coating onto the substrate film and forming the adhesive layer can be performed smoothly, and an adhesive layer of the desired thickness can be easily obtained.

[0062] 1.7 Dielectric properties of cured adhesive compositions 1.7.1 Relative permittivity of the cured product of the adhesive composition The relative permittivity (Dk, εr) of the cured adhesive composition measured at a frequency of 10 GHz is preferably less than 3.0. A relative permittivity of less than 3.0 allows for suitable use in FPC-related products, which have stringent dielectric property requirements to accommodate the increasingly high signal speeds and frequencies of recent years. The relative permittivity is preferably 2.8 or less, more preferably 2.7 or less, and even more preferably 2.6 or less. The relative permittivity can be adjusted by the type and content of each component in the adhesive composition.

[0063] 1.7.2 Dielectric loss tangent of the cured adhesive composition The adhesive composition of this embodiment preferably has a dielectric loss tangent (Df, tanδ) of the cured product of the adhesive composition measured at a frequency of 10 GHz of less than 0.03. If the dielectric loss tangent is less than 0.03, it can be suitably used in FPC-related products that have strict dielectric property requirements to cope with the further increase in signal speed and signal frequency in recent years. The dielectric loss tangent is preferably 0.025 or less, more preferably 0.02 or less, even more preferably 0.015 or less, even more preferably 0.01 or less, and particularly preferably 0.005 or less.

[0064] The relative permittivity and dielectric loss tangent mentioned above can be measured as follows. Specifically, a 38 μm thick release PET film is prepared, and the adhesive composition of this embodiment, prepared in liquid form, is applied to its release-treated surface. Next, this coated film is left in an oven and dried at 90°C for 3 minutes to form a 50 μm thick coating (adhesive layer), obtaining an adhesive layer. Next, this adhesive layer is left in an oven and cured at 180°C for 60 minutes. After that, the release film is peeled off to obtain a test piece (100 mm × 80 mm) made of the cured adhesive composition. The relative permittivity (Dk, εr) and dielectric loss tangent (Df, tanδ) can be measured using a network analyzer 85071E-300 (Agilent Corporation) with the split-post dielectric resonator method (SPDR method) at a temperature of 23°C and a frequency of 10 GHz.

[0065] 1.8 Uses of adhesive compositions The adhesive composition of this embodiment can be suitably used, for example, in flexible copper-clad laminates, rigid copper-clad laminates, flexible flat cables, sealing materials, and the like.

[0066] A flexible copper-clad laminate can be constructed by providing a base film on one side of the adhesive layer in a laminate with an adhesive layer, as described later, and copper foil on the other side of the adhesive layer. Specifically, a flexible copper-clad laminate can be constructed by bonding the base film and copper foil together using a laminate with an adhesive layer, as described later. That is, a flexible copper-clad laminate can be constructed by laminating a base film, an adhesive layer, and copper foil in that order. The adhesive layer and copper foil may be formed on both sides of the base film.

[0067] A rigid copper-clad laminate can be configured with a plate-shaped substrate made of glass epoxy or the like on one side of an adhesive layer made of the above-mentioned adhesive composition, and copper foil on the other side of the adhesive layer. Specifically, a rigid copper-clad laminate can be configured in which the substrate and the copper foil are bonded together using an adhesive layer made of the above-mentioned adhesive composition. That is, a rigid copper-clad laminate can be constructed by laminating the substrate, adhesive layer, and copper foil in that order. The adhesive layer and copper foil may be formed on both sides of the substrate.

[0068] A flexible flat cable can be configured such that a base film is provided on one side of the adhesive layer in a laminate with an adhesive layer, as described later, and copper wiring is provided on the other side of the adhesive layer. Specifically, a flexible flat cable can be configured such that the base film and copper wiring are bonded together using a laminate with an adhesive layer, as described later. That is, a flexible flat cable can be constructed by laminating a base film, an adhesive layer, and copper wiring in that order. Note that the adhesive layer and copper wiring may be formed on both sides of the base film.

[0069] The sealing material can be configured such that a base film is provided on one side of the adhesive layer in the laminate with an adhesive layer described later, and a base film is provided on the other side of the adhesive layer. That is, the sealing material can be laminated in the order of base film, adhesive layer, and base film.

[0070] Furthermore, the adhesive composition of this embodiment can be suitably used not only for the flexible printed circuit board (FPC) related products described above, but also for electronic materials, automotive applications, and the like.

[0071] 2. Laminate with adhesive layer The laminate with adhesive layer according to this embodiment comprises an adhesive layer made of the adhesive composition described above and a base film in contact with at least one surface of the adhesive layer. The adhesive layer is in a B-stage configuration.

[0072] One embodiment of a laminate with an adhesive layer is a coverlay film. A coverlay film typically has an adhesive layer formed on at least one surface of a base film, and is a laminate in which it is difficult to separate the base film from the adhesive layer.

[0073] Examples of base films for laminates with adhesive layers include polyimide films, polyether ether ketone films, polyphenylene sulfide films, aramid films, polyethylene naphthalate films, and liquid crystal polymer films. Among these, polyimide films, polyethylene naphthalate films, and liquid crystal polymer films are preferred from the viewpoint of adhesion and electrical properties.

[0074] As a method for producing a laminate with an adhesive layer, for example, a resin varnish containing the above-mentioned adhesive composition and solvent can be applied to the surface of a base film such as a polyimide film to form a resin varnish layer, and then the solvent can be removed from this resin varnish layer to produce a laminate with an adhesive layer.

[0075] The drying temperature when removing the solvent is preferably 40 to 250°C, and more preferably 70 to 170°C. Drying can be performed by passing the laminate coated with the adhesive composition through a furnace that uses hot air drying, far-infrared heating, and high-frequency induction heating.

[0076] If necessary, a release film may be laminated onto the surface of the adhesive layer for storage purposes. Known release films such as polyethylene terephthalate film, polyethylene film, polypropylene film, silicone release treated paper, polyolefin resin coated paper, polymethylpentene (TPX) film, and fluororesin film can be used.

[0077] Another embodiment of the laminate with an adhesive layer is a bonding sheet. A bonding sheet also has the adhesive layer formed on the surface of a base film, but the base film functions as a release film. Alternatively, the bonding sheet may have an adhesive layer between two release films. The release films are peeled off when the bonding sheet is used. The release films can be the same as those described above.

[0078] One method for manufacturing a bonding sheet is to apply a resin varnish containing the above-mentioned adhesive composition and solvent to the surface of a release film and dry it in the same manner as in the case of the coverlay film.

[0079] In a laminate with an adhesive layer, the thickness of the adhesive layer is preferably 5 μm to 100 μm, more preferably 10 μm to 70 μm, and even more preferably 10 μm to 50 μm, in order to exhibit sufficient adhesive strength.

[0080] In a laminate with an adhesive layer, the thickness of the base film is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 125 μm or less. The lower limit of the thickness of the base film is not particularly limited, but for example, it can be 5 μm or more. According to this disclosure, even when the thickness of the base film is within the above range, the adhesive composition forming the adhesive layer has good alignment properties between the laminate with the adhesive layer and the adherend, so that the deformation suppression effect of the thin base material can be fully enjoyed when re-bonding. In this case, it can also contribute to thinning the laminate with the adhesive layer. [Examples]

[0081] The present invention will be described more specifically based on examples, but the present invention is not limited thereto. In the following, parts and percentages are based on mass unless otherwise specified.

[0082] 1. Evaluation Method (1) Weight average molecular weight Mw GPC measurements were performed under the following conditions to determine the weight-average molecular weight Mw of the modified styrene elastomer (A). The weight-average molecular weight (Mw) was calculated by converting the retention time measured by GPC (Geometric Propagation) to the retention time of standard polystyrene. Equipment: Alliance 2695 (manufactured by Waters) Column: TSKgel SuperMultiporeHZ-H (2 tubes) TSKgel SuperHZ2500 (2 tubes, manufactured by Tosoh Corporation) Column temperature: 40℃ Eluent: Tetrahydrofuran 0.35 ml / min Detector: RI (Differential Refractive Index Detector)

[0083] (2) Acid value 1 g of modified styrene elastomer (A) was dissolved in 30 ml of toluene, and a Kyoto Electronics Manufacturing Co., Ltd. automatic titrator "AT-510" with a Kyoto Electronics Manufacturing Co., Ltd. "APB-510-20B" burette was used. Potentiometric titration was performed using a 0.01 mol / L benzyl alcohol KOH solution as the titrant, and the number of mg of KOH per 1 g of elastomer was calculated.

[0084] (3) Peel bond strength A 38 μm thick release PET film was prepared, and a liquid adhesive composition was roll-coated onto one surface of the film. Next, the film with the adhesive layer was placed in an oven and dried at 90°C for 3 minutes to form a B-stage adhesive layer (25 μm thick). Then, the adhesive layer was aligned and placed on the resin surface of a copper-clad laminate (Dupont, "Pyralux TAS") (substrate A: polyimide resin film / copper foil) (this alignment was considered the first alignment), and lamination was performed at a temperature of 120°C, a pressure of 0.3 MPa, and a speed of 0.5 m / min. Finally, the release PET film was peeled off. Next, the adhesive layer of a laminate consisting of base material A and the adhesive layer was positioned on one copper foil surface of another copper-clad laminate (Dupont, "Pyralux TAH") (base material B: copper foil / polyimide resin film / copper foil) (this positioning was considered the second positioning), and lamination was performed under the conditions of a temperature of 120°C, a pressure of 0.3 MPa, and a speed of 0.5 m / min. Then, the resulting laminated substrate (base material A / adhesive layer / base material B) was heat-pressed at a temperature of 180°C and a pressure of 3 MPa for 60 minutes. From this heat-pressed laminated substrate, adhesive test pieces measuring 10 mm × 100 mm were obtained. Next, to evaluate the adhesiveness, the 180° peel adhesive strength (normal state) (N / mm) was measured under the conditions of a temperature of 23°C and a tensile speed of 50 mm / min, and this was defined as the peel adhesive strength (normal state) (N / mm). The width of the adhesive test pieces during the above measurements was 10 mm in all cases.

[0085] If the 180° peel adhesive strength was 0.7 N / mm or higher, it was marked as "A" as excellent adhesion was ensured. If the 180° peel adhesive strength was 0.5 N / mm or higher but less than 0.7 N / mm, it was marked as "B" as good adhesion was ensured. If the 180° peel adhesive strength of the above adhesive test specimen was 0.3 N / mm or higher but less than 0.5 N / mm, it was marked as "C" as adhesion within an acceptable range was ensured. If the 180° peel adhesive strength of the above adhesive test specimen was less than 0.3 N / mm, it was marked as "D" as adhesion was not ensured.

[0086] (4) Alignment A laminated substrate (substrate A / adhesive layer / substrate B) was fabricated in the same manner as described in "(3) Peel Adhesion Strength" above. At this time, after the second alignment described above, that is, after aligning the adhesive layer of the laminate consisting of substrate A / adhesive layer to one copper foil surface of substrate B (copper foil / polyimide resin film / copper foil), the workability and deformation state of the laminate consisting of substrate A / adhesive layer on substrate B were confirmed by moving the laminate consisting of substrate A / adhesive layer.

[0087] Specifically, if the laminate consisting of base material A / adhesive layer could be moved laterally and could be peeled off without deformation, it was described as "A" because deformation of the base material of the laminate with adhesive layer was suppressed and alignment between the laminate with adhesive layer and the adherend was ensured, indicating excellent alignment. If the laminate consisting of base material A / adhesive layer could not be moved laterally, but could be peeled off without deformation, it was described as "B" because deformation of the base material of the laminate with adhesive layer was suppressed and alignment between the laminate with adhesive layer and the adherend was ensured, indicating good alignment. If the laminate consisting of base material A / adhesive layer could not be moved laterally and deformed when peeled off, it was described as "C" because deformation of the base material of the laminate with adhesive layer and alignment between the laminate with adhesive layer and the adherend could not be ensured.

[0088] In this experiment, the adhesive layer is bonded to copper foil, but similar trends are observed when the adhesive layer is bonded to metals other than copper or to resins, so evaluations of these cases are omitted. Also, in this experiment, the evaluation focuses on the second alignment performance, but if the second alignment performance can be ensured while suppressing deformation of the substrate, it is possible to ensure the first alignment performance while suppressing deformation of the substrate, so the evaluation of the first alignment performance is omitted.

[0089] 2. Raw materials for adhesive compositions The following were prepared as raw materials for the adhesive composition. (1) Modified styrene elastomer (A) • Acid-modified SEBS (a1) (Asahi Kasei Chemicals, "ToughTec M1913", maleic anhydride-modified SEBS, styrene content: 30%, acid value: 10 mg KOH / g, weight-average molecular weight Mw = 150,000)

[0090] (2) Epoxy resin (B) • Dicyclopentadiene type epoxy resin (DCPD type epoxy resin) (b1) (DIC Corporation, "EPICLON HP-7200")

[0091] (3) Unmodified styrene elastomer (C) • Unmodified SEBS(c1) (manufactured by Asahi Kasei Chemicals, "ToughTec H1043", styrene content: 67%, weight-average molecular weight Mw = 35,000) • Unmodified SEBS(c2) (manufactured by Asahi Kasei Chemicals, "ToughTec H1051", styrene content: 42%, weight-average molecular weight Mw = 58,000)

[0092] (4) Lubricant (D) • Pentaerythritol tetrastearate (d1) (manufactured by Riken Vitamin Co., Ltd., "Rikestar EW-480") • Glycerin stearate ester (d2) (manufactured by Riken Vitamin Co., Ltd., "Poem PV-100") (5) Others • Curing accelerator (Shikoku Chemicals Co., Ltd., "Curezol C11Z", imidazole-based curing accelerator)

[0093] A mixed solvent consisting of toluene and methyl ethyl ketone (mass ratio = 90:10) was used as the solvent.

[0094] 3. Manufacturing and evaluation of adhesive compositions Each adhesive composition was prepared and evaluated by adding the above raw materials in the predetermined proportions shown in Tables 1 and 2 to a 1000 ml flask equipped with a stirring device, adding a solvent, and stirring for 6 hours at room temperature (25°C) to dissolve the materials. The results are shown in Tables 1 and 2.

[0095] 4. Manufacturing and evaluation of laminates with adhesive layers Using the above adhesive compositions, laminates with adhesive layers were manufactured and evaluated as described in the explanations of each evaluation method above. The results are shown in Tables 1 and 2.

[0096] [Table 1]

[0097] [Table 2]

[0098] Samples 1 to 4 and 1C to 3C shown in Table 1 are examples of samples relating to content requirement I, while samples 5 to 12 and 4C shown in Table 2 are examples of samples relating to content requirement II.

[0099] According to Table 1 regarding the content requirement I, the following can be seen: In other words, the adhesive composition of sample 1C does not contain both component (C) and component (D). Therefore, although sample 1C was able to ensure adhesion, it was not possible to ensure alignment between the laminate with the adhesive layer and the adherend while suppressing deformation of the substrate of the laminate with the adhesive layer.

[0100] Sample 2C's adhesive composition contains component (C) but does not contain component (D) (it is below the lower limit of the content of component (D)). Therefore, although Sample 2C was able to ensure adhesion, it was not possible to suppress deformation of the substrate of the laminate with the adhesive layer while ensuring alignment between the laminate with the adhesive layer and the adherend.

[0101] Sample 3C contains both component (C) and component (D) in its adhesive composition, but the content of component (D) exceeds the upper limit. As a result, aggregation of the lubricant component (D) occurred in sample 3C, making it impossible to prepare a sample for evaluating alignment and 180° peel adhesion strength.

[0102] In contrast, Samples 1 to 4 satisfy the requirements specified in this disclosure. Therefore, Samples 1 to 4 were able to ensure alignment between the laminate with the adhesive layer and the adherend while suppressing deformation of the substrate of the laminate with the adhesive layer, thereby ensuring adhesion.

[0103] Furthermore, comparing samples 1 to 4, it can be seen that when the content requirement I is met, if the unmodified styrene elastomer of component (C) is included, it becomes easier to improve alignment by increasing the amount of lubricant of component (D). Also, when the content requirement I is met, it can be seen that using the unmodified styrene elastomer of component (C) and the lubricant of component (D) in combination makes it easier to improve alignment than using the lubricant of component (D) alone.

[0104] On the other hand, Table 2 regarding the content requirement II shows the following: In sample 4C, although the adhesive composition contains both component (C) and component (D), the content of component (D) exceeds the upper limit. As a result, aggregation of the lubricant component (D) occurred in sample 4C, making it impossible to prepare a sample for evaluation of alignment and 180° peel adhesion strength.

[0105] In contrast, Samples 5 to 12 satisfy the requirements specified in this disclosure. Therefore, Samples 5 to 12 were able to ensure alignment between the laminate with the adhesive layer and the adherend while suppressing deformation of the substrate of the laminate with the adhesive layer, thereby ensuring adhesion.

[0106] Furthermore, comparing samples 5 to 12, it can be seen that, when content requirement II is met, alignment can be easily improved by using both the unmodified styrene elastomer of component (C) and the lubricant of component (D), or by optimizing the content of the unmodified styrene elastomer of component (C) even when the lubricant of component (D) is not used. However, in the latter case, it is desirable to note that as the content of the unmodified styrene elastomer of component (C) increases, there is a tendency for the 180° peel adhesion strength to decrease.

[0107] The present invention is not limited to the embodiments and examples described above, and various modifications are possible without departing from the spirit of the invention. Furthermore, each of the configurations shown in the embodiments and examples can be combined in any way.

Claims

1. A modified styrene elastomer (A) having reactive functional groups that react with epoxy groups, Epoxy resin (B) and An adhesive composition comprising at least one selected from the group consisting of an unmodified styrene elastomer (C) and a lubricant (D), Amount to 100 parts by mass of the modified styrene elastomer (A): The unmodified styrene-based elastomer (C) is contained in an amount of 0 parts by mass or more but less than 5 parts by mass, and the lubricant (D) is contained in an amount of 0.05 parts by mass or more but less than 12 parts by mass, or Amount to 100 parts by mass of the modified styrene elastomer (A): The product contains 5 parts by mass or more of the unmodified styrene elastomer (C) and 0 parts by mass or more and 12 parts by mass or less of the lubricant (D). Adhesive composition.

2. The modified styrene elastomer (A) is a carboxyl group-containing styrene elastomer. The adhesive composition according to claim 1.

3. The aforementioned unmodified styrene-based elastomer (C) is At least one selected from the group consisting of styrene-butadiene block copolymer, styrene-ethylenepropylene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylenebutylene-styrene block copolymer, styrene-ethylenepropylene-styrene block copolymer, and styrene-(ethylene-ethylene / propylene)-styrene block copolymer. The adhesive composition according to claim 1.

4. The lubricant (D) is It is at least one selected from the group consisting of fatty acid esters, fatty acid amides, fatty acids, fatty acid metal salts, and waxes. The adhesive composition according to claim 1.

5. The present invention comprises an adhesive layer formed from the adhesive composition described in any one of claims 1 to 4, and a base film in contact with at least one surface of the adhesive layer, The adhesive layer is in a B-stage state. Laminate with adhesive layer.