Filamentous adhesive body and laminate

Abstract

Provided is a filamentous adhesive body excellent in impact resistance and in pull-out split-up properties. Also provided is a laminate of the filamentous adhesive body and an electronic device member. The present invention pertains to a filamentous adhesive body comprising a core member and an adhesive agent that covers the longitudinal-direction surface of the core member. The adhesive agent contains a base polymer and particles. The particles have a tensile modulus of elasticity of less than 100 times the tensile modulus of elasticity of the base polymer.

Description

Thread-like adhesive body and laminate

[0001] The present invention relates to a thread-like adhesive material and a laminate.

[0002] Impact-resistant narrow adhesive tapes are required for fixing electronic devices. Adhesive threads are used for adhesive tapes that are used in places where the adhesive area is narrow or when the shapes of the objects to be bonded are complex.

[0003] As an example of a thread-like adhesive material, Patent Document 1 discloses a thread-like adhesive that has excellent impact resistance by providing voids in the thread-like adhesive material, and Patent Document 2 discloses an adhesive tape that has improved impact resistance by adding a filler to the adhesive layer.

[0004] International Publication No. WO 2022 / 071241 International Publication No. WO 2021 / 039878

[0005] However, the thread-like adhesive body described in Patent Document 1 leaves room for further study in terms of impact resistance. Furthermore, when a thread-like adhesive body having the adhesive layer of the adhesive tape described in Patent Document 2 is produced, it has been found that the impact resistance is insufficient.

[0006] The present invention has been made in view of the above-mentioned conventional circumstances, and has as its object to provide a thread-like adhesive material that is excellent in impact resistance and also in pull-out dismantling properties.

[0007] As a result of intensive research into solving the above-mentioned problems, the inventors discovered that the above-mentioned problems can be solved by incorporating a base polymer and particles having a tensile modulus less than 100 times that of the base polymer into a thread-like adhesive body having a core material and an adhesive coating the surface of the core material, thereby solving the present invention.

[0008] That is, the present invention relates to the following: [1] A thread-like adhesive body comprising a core material and an adhesive coating the longitudinal surface of the core material, the adhesive containing a base polymer and particles, the tensile modulus of the particles being less than 100 times the tensile modulus of the base polymer. [2] The thread-like adhesive body according to [1], having a breaking stress of greater than 150 MPa. [3] The thread-like adhesive body according to [1], wherein the rubber hardness of the particles is Shore A75 or less. [4] The thread-like adhesive body according to [1], wherein the average particle size of the particles is 1 μm to 35 μm. [5] The thread-like adhesive body according to [1], comprising 3 to 30 parts by mass of the particles per 100 parts by mass of the base polymer. [6] The thread-like adhesive body according to [1], wherein the mass ratio of the adhesive to the core material (mass of adhesive / mass of core material) is 0.44 or more. [7] The thread-like adhesive material according to [1], wherein the core material is a multifilament yarn. [8] A laminate of the thread-like adhesive material according to any one of [1] to [7] and an electronic device member.

[0009] According to the present invention, it is possible to provide a thread-like adhesive material that is excellent in impact resistance and also in pull-out dismantling property, and also to provide a laminate of the thread-like adhesive material and an electronic device member.

[0010] Hereinafter, embodiments of the thread-like adhesive material of the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below. Furthermore, when the expression "to" is used in this specification, it is used as an expression including the numerical values ​​or physical property values ​​before and after it.

[0011] [Thread-like adhesive body] A thread-like adhesive body according to one embodiment of the present invention comprises a core material and an adhesive that coats the longitudinal surface of the core material, the adhesive containing a base polymer and particles, and the tensile modulus of the particles is less than 100 times the tensile modulus of the base polymer.

[0012] Here, thread-like refers to a shape in which the longitudinal length is sufficiently longer than the width length, and the ratio of the length of the long axis to the length of the short axis in the cross-sectional shape (long axis / short axis) is, for example, 200 or less, preferably 100 or less, more preferably 50 or less, even more preferably 10 or less, still more preferably 5 or less, and particularly preferably 3 or less, and also refers to a shape in which it can be bent in various directions and at various angles like a thread.

[0013] The thread-like adhesive body according to an embodiment of the present invention can be bent in various directions and angles, and can therefore be bent to match the shape of the attachment area, thereby accommodating a variety of shapes of attachment areas.

[0014] The core material and adhesive constituting the thread-like adhesive body according to an embodiment of the present invention will be described below.

[0015] <Core Material> The adhesive thread according to the embodiment of the present invention has a core material. By having a core material, the adhesive thread can be easily pulled out and dismantled. The core material is preferably thread-shaped.

[0016] In this specification, the pull-out dismantling property of a thread-like adhesive body means the ability to dismantle an assembly in which adherends are joined together using a thread-like adhesive body by pulling out the thread-like adhesive body from the assembly.

[0017] The core material preferably has a breaking stress of more than 150 MPa from the viewpoint of improving the pull-out dismantling property of the thread-like adhesive body. More preferably, it is 200 MPa or more, even more preferably 300 MPa or more, and particularly preferably 400 MPa or more. The upper limit of the breaking stress of the core material is preferably 3500 MPa or less, more preferably 3000 MPa or less, from the viewpoint of suppressing a decrease in the impact resistance of the thread-like adhesive body.

[0018] The core material preferably has multiple filaments and is a multifilament yarn obtained by doubling or twisting the multiple filaments. When the core material is a multifilament yarn, sufficient strength and stable physical properties can be obtained. As a result, a thread-like adhesive material with low quality variation, excellent strength, and excellent adhesive force can be obtained.

[0019] The number of filaments contained in the core material is preferably 4 or more, more preferably 10 or more, and particularly preferably 20 or more, from the viewpoint of adhesive strength.

[0020] On the other hand, if the thickness (fineness) of the core material is kept at the same level, as the number of filaments increases, each filament becomes thinner (the fineness decreases). If each filament becomes too thin, the strength and handleability of the core material may decrease, and the breaking stress of the core material may also decrease. Therefore, the number of filaments is preferably 2,000 or less, more preferably 1,500 or less, and particularly preferably 1,000 or less.

[0021] There are no particular limitations on the type of resin used for the filament, and it may be appropriately selected depending on the required properties such as strength, mass, hardness, breaking stress, etc. Examples include materials containing polymeric materials such as thermoplastic polymers, thermosetting polymers, and rubber.

[0022] Specifically, polymeric materials such as rayon, cupra, acetate, promix, nylon, aramid, vinylon, vinylidene, polyvinyl chloride, acrylic, polyolefin (polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc.), polyester resin (polyethylene terephthalate, etc.), vinyl chloride resin, vinyl acetate resin, polyimide resin, polyamide resin, fluororesin, polyurethane, polychlor, polylactic acid, etc.; rubbers such as synthetic rubber (natural rubber, polyurethane, etc.); foams such as polyurethane foam and polychloroprene rubber foam, etc. can be used. From the viewpoint of breaking stress, among these, polyester resin is preferred, and polyethylene terephthalate is more preferred.

[0023] The content of the filaments in the core material is preferably from 10 to 100% by mass, more preferably from 50 to 100% by mass, and particularly preferably from 80 to 100% by mass.

[0024] The core material may contain various additives, such as fillers (inorganic fillers, organic fillers, etc.), antioxidants, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, plasticizers, colorants (pigments, dyes, etc.), etc. The surface of the core material may be subjected to known or conventional surface treatments, such as corona discharge treatment, plasma treatment, or application of a primer.

[0025] The shape of the core material is not particularly limited and may be adjusted appropriately depending on the required properties such as strength, mass, hardness, breaking stress, etc. The cross-sectional shape of the core material is typically circular, but may also be various other shapes such as elliptical or polygonal.

[0026] The core material may have a plurality of filaments, and may be a yarn obtained by combining a filament with a spun yarn, textured yarn, hollow yarn, etc. by twisting it together. Examples of textured yarn include textured yarns that have been subjected to crimping, bulking, or the like, and are generally called textured yarns, bulky yarns, and stretch yarns.

[0027] The thickness of the core material is not particularly limited, and may be adjusted appropriately depending on the application so that the thickness of the thread-like adhesive body is appropriate.

[0028] The twist number of the core material is preferably 1 turn / m or more. If the twist number is 1 turn / m or more, the variation in the outer diameter of the thread-like adhesive body can be suppressed. The twist number of the core material is more preferably 20 turns / m or more, and even more preferably 50 turns / m or more.

[0029] On the other hand, in order to ensure that the core material is sufficiently deformed when multiple articles are bonded together and to increase the amount of adhesive attached per unit length, it is preferable that the twist of the core material is not too strong. Therefore, the number of twists of the core material is preferably 500 times / m or less, more preferably 300 times / m or less, and even more preferably 200 times / m or less.

[0030] Furthermore, when the core material is twisted, it is preferable to also control the twist coefficient K, which is expressed by the following formula (A), from the same viewpoint as above. The twist coefficient K is an index for discussing the influence of twist (influence on the core material's cohesion, ease of deformation, amount of adhesive attached, etc.) regardless of the thickness of the core material. In other words, the influence of the number of twists on the core material differs depending on the thickness of the core material, but if the twist coefficient K is the same, it indicates that the influence of twist on the core material is the same regardless of the thickness of the core material.

[0031] The twist coefficient K is preferably 0 or more, and more preferably greater than 0. On the other hand, if the twist coefficient K is 200 or less, the flexibility of the core material, and therefore the thread-like adhesive body, is improved, making it easier to apply to complex shapes such as curved portions, bent portions, uneven portions, and narrow areas. Therefore, the twist coefficient K is preferably 200 or less, more preferably 100 or less, and even more preferably less than 60.

[0032]

[0033] In formula (A), K represents the twist coefficient, T represents the number of twists (turns / m), and D represents the fineness (dtex).

[0034] <Adhesive> The thread-like adhesive body according to an embodiment of the present invention has an adhesive that coats a core material, and the adhesive contains a base polymer and particles. The adhesive according to this embodiment can be formed from an adhesive composition, and the adhesive may be an adhesive composition. Furthermore, the adhesive may form a layer (adhesive layer).

[0035] The adhesive preferably covers the entire longitudinal surface of the core material. The entire longitudinal surface of the core material refers to the entire circumferential surface of the core material, and means the entire 360° circumference of the surface of the core material, centered on the center line of the longitudinal direction of the core material.

[0036] However, the end faces of the core material may or may not be coated with adhesive. For example, if the thread-like adhesive body is cut during production or use, the end faces of the core material may not be coated with adhesive.

[0037] By coating the entire longitudinal surface of the core material with adhesive, a thread-like adhesive body with excellent impact resistance can be obtained. This is presumably because the core material does not protrude from the surface, ensuring a sufficient adhesive area and preventing the bonded body from peeling off.

[0038] The coverage of the core material with the adhesive (the area (%) of the adhesive per unit area of ​​the surface of the core material) is preferably 50 area% or more, more preferably 80 area% or more, even more preferably 90 area% or more, and particularly preferably 95 area% or more. If the coverage of the core material is 50 area% or more, a sufficient adhesive area can be secured, and a thread-like adhesive body with excellent impact resistance can be obtained.

[0039] The adhesive forming the adhesive layer may be impregnated into the core material. Here, "the adhesive is impregnated into the core material" means that the adhesive is present between multiple filaments in the core material. When the adhesive is impregnated into the core material, the adhesive and the core material maintain adhesion, making them less likely to peel off, and improving the strength of the thread-like adhesive body.

[0040] (Base Polymer) The pressure-sensitive adhesive in this embodiment is formed from a pressure-sensitive adhesive containing a base polymer as a main component. The type of pressure-sensitive adhesive is not particularly limited, and examples thereof include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, vinyl alkyl ether pressure-sensitive adhesives, silicone pressure-sensitive adhesives, polyester pressure-sensitive adhesives, polyamide pressure-sensitive adhesives, urethane pressure-sensitive adhesives, fluorine-based pressure-sensitive adhesives, and epoxy pressure-sensitive adhesives.

[0041] Among these, from the viewpoint of adhesiveness, acrylic adhesives and rubber adhesives are preferred, and acrylic adhesives are more preferred. Note that the adhesives may be used alone or in combination of two or more.

[0042] The rubber-based adhesive is based on a rubber-based polymer such as natural rubber, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-butadiene rubber, polybutadiene, polyisoprene, polyisobutylene, butyl rubber, chloroprene rubber, or silicone rubber.

[0043] Here, "acrylic pressure-sensitive adhesive" refers to a pressure-sensitive adhesive having an acrylic polymer as the base polymer (the main component of the polymer, i.e., a component accounting for 50% by mass or more). "Acrylic polymer" refers to a polymer having a monomer having at least one (meth)acryloyl group in one molecule (hereinafter, this may be referred to as "acrylic monomer") as the main constituent monomer component (the main component of the monomer, i.e., a component accounting for more than 50% by mass of the total amount of monomers constituting the acrylic polymer). Furthermore, in this specification, "(meth)acryloyl" refers to acryloyl and methacryloyl in a comprehensive sense. Similarly, "(meth)acrylic acid ester" refers to acrylic acid ester and methacrylic acid ester, and "(meth)acrylic" refers to acrylic and methacrylic in a comprehensive sense.

[0044] The acrylic polymer is preferably a polymer of a monomer raw material that contains, for example, an alkyl(meth)acrylate as a main monomer and may further contain a secondary monomer copolymerizable with the main monomer, where the main monomer refers to a component that accounts for more than 50% by mass of the monomer composition in the monomer raw material.

[0045] As the alkyl(meth)acrylate, for example, a compound represented by the following formula (1) can be suitably used: CH ２ = C(R １ ) COOR ２ (1) Here, R in the above formula (1) １ is a hydrogen atom or a methyl group. ２ is a chain alkyl group having 1 to 20 carbon atoms. Hereinafter, this range of carbon atoms will be referred to as "C １－２０ " is sometimes expressed as ".

[0046] R ２ is C １－２０Examples of alkyl(meth)acrylates, which are chain alkyl groups, include methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, s-butyl(meth)acrylate, pentyl(meth)acrylate, isopentyl(meth)acrylate, hexyl(meth)acrylate, heptyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, octyl(meth)acrylate, and isooctyl(meth)acrylate. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ...

[0047] From the viewpoint of adhesive stability, etc., R ２ is C １－１４ (For example, C ２－１０ , typically C ４－８ It is suitable to use alkyl (meth)acrylate, which is a chain alkyl group of the formula (I), as the main monomer.

[0048] From the viewpoint of adhesive properties, R １ is a hydrogen atom and R ２ is C ４－８ alkyl acrylate (hereinafter simply referred to as C ４－８ It is preferable to use alkyl acrylates (also called alkyl acrylates) as the main monomer. Preferred examples include n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA).

[0049] That is, the PSA contains an acrylic polymer, and the amount of n-butyl acrylate or 2-ethylhexyl acrylate relative to the total amount of the monomer components constituting the acrylic polymer is preferably more than 50% by mass, more preferably 60% by mass or more, and even more preferably 70% by mass or more. From the viewpoint of suppressing a decrease in adhesive strength, it is preferably 97% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less.

[0050] In this embodiment, C is used relative to the total amount of monomer components constituting the acrylic polymer. ４－８ The composition can be preferably implemented in an embodiment in which the total amount of alkyl acrylate is more than 50% by mass, and may be 60% by mass or more, 70% by mass or more, or 85% by mass or more. On the other hand, from the viewpoint of cohesive strength, etc., the proportion of C in the monomer components is preferably 100% by mass or more. ４－８ The proportion of alkyl acrylate is usually suitably 99.5% by mass or less, and may be 98% by mass or less (for example, less than 97% by mass).

[0051] The total amount of alkyl(meth)acrylate relative to the total amount of monomer components constituting the acrylic polymer is typically more than 50% by mass, and can be, for example, 70% by mass or more, or 85% by mass or more, or even 90% by mass or more. The proportion of alkyl(meth)acrylate in the monomer components is typically less than 100% by mass, and from the viewpoint of cohesive strength, etc., it is usually appropriate to set it to 99.5% by mass or less, and it may be 98% by mass or less (for example, less than 97% by mass).

[0052] The acrylic polymer may contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer. Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, crotonic acid, and isocrotonic acid; ethylenically unsaturated dicarboxylic acids such as maleic acid, itaconic acid, and citraconic acid, and their anhydrides (maleic anhydride, itaconic anhydride, etc.); and the like. These can be used alone or in combination of two. Among them, acrylic acid (AA) and methacrylic acid (MAA) are preferred as carboxyl group-containing monomers. AA is particularly preferred.

[0053] In an embodiment in which a carboxyl group-containing monomer is copolymerized with an acrylic polymer, the content of the carboxyl group-containing monomer relative to the total amount of the monomer components constituting the acrylic polymer is not particularly limited, and can be, for example, 0.2% by mass or more (typically 0.5% by mass or more), and usually 1% by mass or more is appropriate, and may be 2% by mass or more, or 3% by mass or more. The upper limit of the content of the carboxyl group-containing monomer is not particularly limited, but from the viewpoint of maintaining good adhesive properties, it can be, for example, 15% by mass or less, or may be 12% by mass or less, or may be 10% by mass or less.

[0054] The acrylic polymer may be formed using, as a monomer component, one or more of the following functional group-containing monomers (excluding the above-mentioned carboxy group-containing monomers): Hydroxyl group-containing monomers: hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol; and polypropylene glycol mono(meth)acrylate. Amide group-containing monomers: (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methylolpropane (meth)acrylamide, N-methoxymethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide. Amino group-containing monomers: for example, aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate. Epoxy group-containing monomers: for example, glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, allyl glycidyl ether. Cyano group-containing monomers: for example, acrylonitrile, methacrylonitrile. Keto group-containing monomers: for example, diacetone (meth)acrylamide, diacetone (meth)acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, vinyl acetoacetate. Monomers having a nitrogen atom-containing ring: for example, N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, and N-(meth)acryloylmorpholine.

[0055] When the monomer component constituting the acrylic polymer contains the functional group-containing monomer described above, the content of the functional group-containing monomer in the monomer component is not particularly limited. From the viewpoint of properly achieving the effects of using the functional group-containing monomer, the content of the functional group-containing monomer in the monomer component can be, for example, 0.1% by mass or more, typically 0.5% by mass or more, and may be 1% by mass or more. Furthermore, from the viewpoint of easily balancing the adhesive performance, typically 40% by mass or less is suitable, preferably 20% by mass or less, and may be 10% by mass or less (e.g., 5% by mass or less). The technology disclosed herein can also be preferably implemented in an embodiment in which the monomer component is substantially free of functional group-containing monomers (e.g., an embodiment in which the monomer component is substantially composed only of alkyl (meth)acrylate and carboxy group-containing monomer). Here, "substantially free of functional group-containing monomers" means that functional group-containing monomers are not used at least intentionally, and for example, unintentional inclusion of 0.05% by mass or less (typically 0.01% by mass or less) of functional group-containing monomers is acceptable.

[0056] The monomer components constituting the acrylic polymer may contain copolymerization components other than the above-mentioned monomers. Examples of the copolymerization components include vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl laurate; aromatic vinyl compounds such as styrene, substituted styrenes (α-methylstyrene, etc.), and vinyltoluene; cycloalkyl(meth)acrylates such as cyclohexyl(meth)acrylate, cyclopentyl(meth)acrylate, and isobornyl(meth)acrylate; and aromatic ring-containing (meth)acrylates such as aryl(meth)acrylates (e.g., phenyl(meth)acrylate), aryloxyalkyl(meth)acrylates (e.g., phenoxyethyl(meth)acrylate), and arylalkyl(meth)acrylates (e.g., benzyl(meth)acrylate). olefin-based monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; isocyanate group-containing monomers such as 2-(meth)acryloyloxyethyl isocyanate; alkoxy group-containing monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; vinyl ether-based monomers such as methyl vinyl ether and ethyl vinyl ether; polyfunctional monomers having two or more (e.g., three or more) polymerizable functional groups (e.g., (meth)acryloyl groups) in one molecule, such as 1,6-hexanediol di(meth)acrylate and trimethylolpropane tri(meth)acrylate; and the like.

[0057] The amount of such other copolymerization components can be appropriately selected depending on the purpose and application, and is not particularly limited. From the viewpoint of properly exerting the effects of use, it is usually appropriate to set it to 0.05% by mass or more, and it may be 0.5% by mass or more. Furthermore, from the viewpoint of easily balancing adhesive performance, the content of other copolymerization components in the monomer component is usually appropriate to be 20% by mass or less, and may be 10% by mass or less (e.g., 5% by mass or less). In this embodiment, an embodiment in which the monomer component is substantially free of other copolymerization components can also be preferably implemented. Here, "substantially free of other copolymerization components" means that other copolymerization components are not used at least intentionally, and it is acceptable for other copolymerization components to be unintentionally included, for example, at 0.01% by mass or less.

[0058] The tensile modulus of the base polymer (E ｐ The tensile modulus (E ｐ ') is preferably 3.0 MPa or less, more preferably 2.5 MPa or less, and even more preferably 2.0 MPa or less.

[0059] The tensile modulus of the base polymer (E ｐ The storage modulus (G ′) of the base polymer can be determined, for example, as follows: First, the storage modulus (G ｐ Next, the tensile modulus (E ｐ ') is calculated. ｐ '=E ｐ ' / 2(1+v) (1) In the above formula (1), v is the Poisson's ratio of the base polymer, which is set to 0.5 in this specification. More specifically, it can be measured by the method described in the examples below.

[0060] In an embodiment of the present invention, the base polymer can be obtained by (co)polymerizing monomer components. The polymerization method is not particularly limited, but examples thereof include solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization (active energy ray polymerization). When copolymerized, the base polymer may be any of a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, and the like.

[0061] In the emulsion polymerization method, the raw material monomers (monomer mixture) can be emulsion polymerized using an emulsifier and a polymerization initiator.

[0062] A reactive emulsifier having a polymerizable group (hereinafter referred to as a "reactive emulsifier" or sometimes referred to as a "reactive surfactant") can also be used as the emulsifier. Use of a reactive emulsifier is preferred because the emulsifier is incorporated into the base polymer, reducing contamination caused by the emulsifier.

[0063] Examples of the reactive emulsifier include anionic emulsifiers, nonionic emulsifiers, and cationic emulsifiers to which a radically polymerizable functional group such as a vinyl group, a propenyl group, an isopropenyl group, a vinyl ether group, or an allyl ether group has been introduced. Specific examples include polyoxyethylene styrenated propenyl phenyl ether sulfate ammonium, polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ammonium, polyoxyethylene styrenated propenyl phenyl ether, polyoxyethylene-1-(allyloxymethyl) alkyl ether, and ammonium-α-sulfonato-ω-1-(allyloxymethyl) alkyloxy polyoxyethylene. When a reactive emulsifier is used, the base polymer obtained by emulsion polymerization contains monomer units derived from the reactive emulsifier.

[0064] As the reactive emulsifier, for example, commercially available products such as those under the trade name "ADEKA REASOAP SE-10N" (manufactured by ADEKA Corporation), those under the trade name "AQUALON HS-10" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), those under the trade name "AQUALON HS-05" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), those under the trade name "AQUALON HS-1025" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), those under the trade name "AQUALON KH-1025" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), and those under the trade name "AQUALON AR-10" (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) can also be used.

[0065] The amount of the reactive emulsifier blended (used) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 6 parts by mass, and even more preferably 1 to 4 parts by mass, per 100 parts by mass of the total amount of raw material monomers constituting the base polymer (all raw material monomers).

[0066] The polymerization initiator is not particularly limited, and polymerization initiators generally used in emulsion polymerization, such as azo-based polymerization initiators, peroxide-based polymerization initiators, and redox-based polymerization initiators, can be used.

[0067] The base polymer is preferably a polymer polymerized using a chain transfer agent. Examples of the chain transfer agent that can be preferably used include terpene compounds such as α-pinene, β-pinene, limonene, and terpinolene. Compounds having a thiol group or a hydroxyl group are also commonly known.

[0068] Examples of the compound having a thiol group include mercaptans such as lauryl mercaptan, 2-mercaptoethyl alcohol, t-dodecyl mercaptan, and mercaptosuccinic acid, alkyl mercaptopropionates such as n-butyl mercaptopropionate and octyl mercaptopropionate, and alkoxyalkyl mercaptopropionates such as methoxybutyl mercaptopropionate, etc. Examples of the compound having a hydroxyl group include alcohols such as methyl alcohol, n-propyl alcohol, isopropyl alcohol (IPA), t-butyl alcohol, and benzyl alcohol.

[0069] The amount of the chain transfer agent used is preferably 0 to 1 part by mass per 100 parts by mass of the total amount of raw material monomers used in emulsion polymerization (all raw material monomers). By using an amount of 1 part by mass or less, it is possible to prevent a decrease in water resistance, heat resistance, etc. due to a decrease in molecular weight, and to prevent the problem of guide roll contamination from occurring, which is preferable.

[0070] The emulsion polymerization of the base polymer can be carried out by emulsifying the monomer components in an aqueous medium using a conventional method, followed by emulsion polymerization, thereby preparing an aqueous dispersion (polymer emulsion) containing the base polymer.

[0071] (Particles) The pressure-sensitive adhesive of the present embodiment contains particles. The tensile modulus of elasticity (E ｆ ') is the tensile modulus (E ｐ The thickness of the adhesive is less than 100 times that of the adhesive. When the adhesive contains such relatively soft particles, stress is dispersed when an impact is applied to the thread-like adhesive body, thereby improving impact resistance. Only one type of the above particles may be used, or two or more types may be used.

[0072] The tensile modulus of the particles (E ｆ ') is the tensile modulus of the base polymer (E ｐ From the viewpoint of improving impact resistance, the ratio is preferably 75 times or less, more preferably 50 times or less, even more preferably 20 times or less, particularly preferably 10 times or less, and most preferably 5 times or less. From the viewpoint of coatability, the lower limit is preferably 0.1 times or more, more preferably 1.0 times or more, and even more preferably 2.0 times or more.

[0073] The tensile modulus of the particles (E ｆ The tensile modulus (E ｆ ') is preferably 0.01 MPa or more, more preferably 0.05 MPa or more, and even more preferably 0.10 MPa or more.

[0074] The tensile modulus of the particles (E ｆThe thickness (%) can be measured, for example, using a nanoindenter. More specifically, it can be measured by the method described in the Examples below.

[0075] From the viewpoint of improving impact resistance, the rubber hardness of the particles is preferably Shore A 75 or less. The rubber hardness is more preferably Shore A 70 or less, even more preferably Shore A 60 or less, particularly preferably Shore A 50 or less, and most preferably Shore A 40 or less. From the viewpoint of coatability, the lower limit of the rubber hardness can be, for example, Shore A 10.

[0076] The average particle size of the particles is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 1.0 μm or more. From the viewpoints of manufacturability and appearance of the thread-like adhesive body, the upper limit of the average particle size of the particles is preferably 35 μm or less, more preferably 25 μm or less, even more preferably 20 μm or less, particularly preferably 15 μm or less, and most preferably 10 μm or less. The average particle size of the particles is preferably 0.1 μm to 35 μm, more preferably 0.5 μm to 35 μm, and even more preferably 1 μm to 35 μm. The average particle size is the median diameter (D50) measured by dynamic light scattering. When the adhesive according to the embodiment of the present invention contains two or more types of particles, the average particle size of the particles is the average particle size of all the particles.

[0077] The particles may be either organic or inorganic, but are preferably organic in order to ensure that the tensile modulus of the particles falls within a predetermined range.

[0078] Materials constituting the organic matter are preferably those generally called rubber or thermoplastic elastomers. Specific examples include silicone-based resins such as silicone and silicone resin; polyolefin-based resins such as polyethylene; polyurethane-based resins; vinyl chloride resins (PVC) such as chloroprene; rubber-based resins such as natural rubber and synthetic rubber; acrylic resins such as acrylic copolymers; blends and hybrids (also called composites) of the above resins; and the like. Of these, silicone-based resins are preferred.

[0079] The particles may have a hollow structure. The hollow portion (internal space of the hollow particle) of the particle having the hollow structure may be in a vacuum state or may be filled with a medium. Examples of the medium include an inert gas such as nitrogen or argon, air, and a volatile solvent.

[0080] In the pressure-sensitive adhesive according to an embodiment of the present invention, the particle content is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of the base polymer. Furthermore, the particle content is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, per 100 parts by mass of the base polymer. By including the particle content at 3 parts by mass or more, it is easy to obtain an improved impact resistance effect. Furthermore, by including the particle content at 50 parts by mass or less, it is difficult to impair adhesive performance and impact resistance. The pressure-sensitive adhesive according to an embodiment of the present invention preferably includes 3 to 30 parts by mass of the particles per 100 parts by mass of the base polymer.

[0081] In addition to the base polymer and particles, the adhesive may contain various additives, such as a tackifying resin, a crosslinking agent, a viscosity modifier (such as a thickener), a leveling agent, a release modifier, a plasticizer, a softener, a filler, a colorant (such as a pigment or dye), a surfactant, an antistatic agent, a preservative, an antioxidant, an ultraviolet absorber, an antioxidant, and a light stabilizer, as appropriate.

[0082] It is preferable to blend a crosslinking agent into the acrylic pressure-sensitive adhesive. The crosslinking agent used in the acrylic pressure-sensitive adhesive can be a commonly used crosslinking agent, such as a silane-based crosslinking agent, an organic peroxide, an epoxy-based compound, an amino group-containing compound, an organic metal salt, a metal alcoholate, a metal chelate, a hydrazide-based crosslinking agent, a carbodiimide-based crosslinking agent, an isocyanate-based crosslinking agent, or a silanol-based crosslinking agent. Among these, organic metal salts, metal chelates, hydrazide-based crosslinking agents, and silane-based crosslinking agents are preferred because they rapidly complete crosslinking after the pressure-sensitive adhesive composition is dried. In the case of a water-dispersible pressure-sensitive adhesive, hydrazide-based crosslinking agents and silane-based crosslinking agents are particularly preferred. The crosslinking agent may be either oil-soluble or water-soluble, and may be used alone or in combination of two or more.

[0083] As the silane crosslinking agent, it is preferable to use a silane monomer copolymerizable with the (meth)acrylic acid alkyl ester. The silane monomer is not particularly limited as long as it is a polymerizable compound having a silicon atom. However, silane compounds having a (meth)acryloyl group, such as (meth)acryloyloxyalkylsilane derivatives, are preferred because of their excellent copolymerizability with the (meth)acrylic acid alkyl ester. Examples of silane monomers include γ-methacryloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-acryloyloxypropylmethyldiethoxysilane. These silane monomers can be used alone or in combination of two or more.

[0084] In addition to the above, examples of copolymerizable silane monomers that can be used include vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.

[0085] The amount of the crosslinking agent used can be appropriately selected depending on the type of the monomer raw material, the application of the adhesive article, etc. In this embodiment, the amount of the crosslinking agent relative to 100 parts by mass of the monomer raw material (excluding the crosslinking agent) is preferably 0.005 to 5 parts by mass, and more preferably 0.01 to 3 parts by mass.

[0086] In this embodiment, other crosslinking agents may also be used, and crosslinking using other crosslinking agents, UV crosslinking, radiation crosslinking such as electron beam crosslinking, etc. may be applied. As the other crosslinking agent, a commonly used crosslinking agent may be used, and examples thereof include organic peroxides, epoxy compounds, amino group-containing compounds, organic metal salts, metal alcoholates, metal chelates, hydrazide crosslinking agents, carbodiimide crosslinking agents, isocyanate crosslinking agents, and silane or silanol crosslinking agents. The other crosslinking agent may be either oil-soluble or water-soluble.

[0087] Any appropriate tackifying resin can be used as the tackifying resin. Specific examples of the tackifying resin include rosin-based tackifying resins (e.g., unmodified rosin, modified rosin, rosin phenolic resins, rosin ester resins, etc.), terpene-based tackifying resins (e.g., terpene resins, terpene phenolic resins, styrene-modified terpene resins, aromatic-modified terpene resins, hydrogenated terpene resins), hydrocarbon-based tackifying resins (e.g., aliphatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aromatic hydrocarbon resins (e.g., styrene-based resins, xylene-based resins, etc.), aliphatic / aromatic petroleum resins, aliphatic / alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone-based resins, coumarone-indene resins, etc.), phenol-based tackifying resins (e.g., alkylphenol-based resins, xylene-formaldehyde-based resins, resols, novolacs, etc.), ketone-based tackifying resins, polyamide-based tackifying resins, epoxy-based tackifying resins, and elastomer-based tackifying resins. Among these, rosin-based tackifying resins, terpene-based tackifying resins, and hydrocarbon-based tackifying resins (such as styrene-based resins) are preferred. The tackifying resins may be used alone or in combination of two or more.

[0088] In an embodiment in which the PSA contains a tackifier resin, the amount of the tackifier resin added is preferably 1 part by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, and even more preferably 30 parts by mass or more, relative to 100 parts by mass of the base polymer. From the viewpoint of suppressing a decrease in the adhesive strength of the PSA, the amount is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 70 parts by mass or less.

[0089] The adhesive composition that forms the adhesive contains a base polymer, particles, and a tackifier resin, and preferably contains 1 to 100 parts by mass of the tackifier resin per 100 parts by mass of the base polymer.

[0090] The PSA composition may be either a solvent-based PSA or a water-dispersed PSA, with the water-dispersed PSA composition being preferred because it allows high-speed coating, is environmentally friendly, and has minimal effects (swelling, dissolution) on the core material due to the solvent.

[0091] Specifically, the adhesive amount (mass of adhesive per unit length) is preferably 20 mg / 60 cm or more, more preferably 30 mg / 60 cm or more, and even more preferably 35 mg / 60 cm or more. On the other hand, if the adhesive amount is excessive, the adhesive composition needs to be applied to the core material multiple times in the manufacturing process, and the applied adhesive composition takes a long time to dry, resulting in low manufacturing efficiency. Therefore, the adhesive amount is preferably 70 mg / 60 cm or less, more preferably 60 mg / 60 cm or less, and even more preferably 50 mg / 60 cm or less.

[0092] The mass ratio of the adhesive to the core material (mass of adhesive / mass of core material) is preferably 0.44 or more. By setting the mass ratio of the adhesive to the core material to 0.44 or more, impact resistance is improved. The mass ratio is more preferably 0.50 or more, and even more preferably 0.55 or more. The upper limit of the ratio is preferably 1.50 or less. By setting the mass ratio of the adhesive to the core material to 1.50 or less, production efficiency can be improved and variation in the outer diameter of the thread-like adhesive body can be suppressed. The ratio is more preferably 1.0 or less, and even more preferably 0.70 or less.

[0093] In this embodiment, the thread width of the thread-like adhesive body is preferably 50 to 2000 μm, more preferably 100 to 1000 μm, from the viewpoint of strength and ease of handling.

[0094] In this embodiment, the breaking stress of the thread-like adhesive body is preferably greater than 150 MPa from the viewpoint of improving the pull-out dismantling property of the thread-like adhesive body. It is more preferably 200 MPa or more, even more preferably 300 MPa or more, and particularly preferably 400 MPa or more. From the viewpoint of handleability, the upper limit of the breaking stress of the thread-like adhesive body is preferably 3500 MPa or less, more preferably 2000 MPa or less. The breaking stress of the thread-like adhesive body can be set within a predetermined range, for example, by setting the type and fineness of the core material within the above-mentioned preferred ranges.

[0095] [Method for manufacturing a thread-like adhesive body] The thread-like adhesive body according to an embodiment of the present invention can be manufactured by a known method, for example, by a method including a coating step of applying a coating liquid containing an adhesive to a core material.

[0096] The coating liquid may be applied to the core material by, for example, dipping, immersion, or coating, and may be dried by heating as necessary. The drying by heating may be carried out, for example, at a temperature of 80 to 120°C, preferably 90 to 110°C, for example, for 20 seconds to 3 minutes, preferably 30 seconds to 2 minutes.

[0097] The coating liquid can be applied using a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater.

[0098] The method for producing a thread-like adhesive body of this embodiment may or may not include a fiber-opening step, in which the core material is opened by running the core material along a non-rotating roller when the adhesive is applied to the core material.

[0099] Furthermore, when the method for producing a thread-like adhesive material of this embodiment includes a coating step, it is preferable that a roller is used in the coating step, and the rotation speed of the roller is 0.3 to 5.0 times the payout speed of the core material. By keeping the rotation speed of the roller within the above range, it is possible to prevent the core material from opening.

[0100] The rotation speed of the roller is more preferably 0.4 to 4.0 times the core material payout speed, further preferably 0.5 to 3.0 times, and particularly preferably 0.8 to 1.5 times.

[0101] In addition, it is preferable to apply a tension of 6.0 mN / dtex or less to the core material in the coating step. By applying a tension of 6.0 mN / dtex or less to the core material, it is possible to prevent the core material from opening.

[0102] The tension applied to the core material is preferably 0.2 to 6.0 mN / dtex, more preferably 0.4 to 5.0 mN / dtex.

[0103] [Uses of adhesive threads] The adhesive threads according to the embodiments of the present invention can be attached to narrow members or narrow areas while suppressing overflow, can be easily applied to complex shapes such as curves, curved surfaces, and uneven surfaces, and are also preferred in that they can be easily disassembled (reworked). Furthermore, due to their excellent adhesive strength, they can be used to adhere various articles. For example, the adhesive threads according to the embodiments of the present invention can be suitably used for fixing articles in the manufacture of electronic devices and for fixing in-vehicle components, and can be applied to fixing narrow bezels of mobile terminals such as mobile phones and smartphones, and for fixing batteries, motors, etc.

[0104] Furthermore, for example, when an adhesive tape is applied to an adherend having a complex shape such as a curve, a curved surface, or an uneven surface, wrinkles and overlaps occur in the adhesive tape in those areas, making it difficult to apply the tape neatly while preventing overhang. Furthermore, the wrinkles and overlaps may also cause a decrease in adhesive strength. To apply the adhesive tape without wrinkles or overlaps, it is possible to cut the adhesive tape into small pieces before application, but this significantly reduces workability. On the other hand, the adhesive thread according to the embodiment of the present invention can be firmly applied without wrinkles or overlaps even when applied to a complex shape such as a curve, a curved surface, or an uneven surface. Furthermore, since the adhesive thread can be applied to the desired area all at once, i.e., in a single process, it is highly efficient and can be applied to automated lines.

[0105] Specifically, the thread-like adhesive material according to an embodiment of the present invention can be suitably used for fixing, in a desired shape, cables such as electric wires and optical fibers, LED fiber lights, optical fiber sensors such as FBGs (Fiber Bragg Gratings), various wires (linear members) such as threads, strings, and wires, and thin members.

[0106] Even when fixing a wire or a narrow member having a complex shape to another member, the adhesive thread according to the embodiment of the present invention can be used to firmly fix the wire or narrow member with excellent workability while suppressing protrusion, wrinkles, and overlaps, in accordance with the complex shape of the wire or narrow member. When fixing a wire or narrow member to another member, the adhesive thread according to the embodiment of the present invention can be attached in advance to the surface of the other member in accordance with the shape to which the wire or narrow member is to be fixed, and then the wire or narrow member can be attached to the adhesive thread attached to the surface of the other member. Alternatively, the adhesive thread according to the embodiment of the present invention can be attached to the wire or narrow member, and then the wire or narrow member can be fixed to the other member in the desired shape.

[0107] Furthermore, the thread-like adhesive material according to the embodiment of the present invention can also be suitably used for the purpose of temporarily fixing (temporarily fastening) an article to the surface of another article. More specifically, the thread-like adhesive material according to the embodiment of the present invention can be used for the purpose of temporarily fixing (temporarily fastening) an article to the surface of another article, for example, when manufacturing textile products such as clothing, shoes, bags, and hats, or leather products. However, the use is not limited thereto, and the thread-like adhesive material according to the embodiment of the present invention can be suitably used for various applications in which temporary fixing (temporarily fastening) is desired. For example, when fixing an article to the surface of another article, the article is temporarily fixed to the surface of the other article using the thread-like adhesive material in advance to position the article, and then the two articles are fixed (mainly fixed) by a fixing method such as thermocompression bonding or sewing. In this case, the thread-like adhesive material according to the embodiment of the present invention can easily be used to temporarily fix the two articles while avoiding the fixing portion provided between the two articles. For example, when sewing textile products or leather products, temporary fixing using the thread-like adhesive material makes it easy to temporarily fix the articles while avoiding the sewing portion, and can easily prevent the adhesive from adhering to the needle.

[0108] Furthermore, as described above, the adhesive thread according to the embodiment of the present invention can be used to successfully bond both articles, even if they have complex shapes such as curves, curved surfaces, or uneven surfaces, while minimizing overflow, wrinkles, and overlaps. Furthermore, the adhesive thread according to the embodiment of the present invention can be bonded in a single step, resulting in excellent workability. Furthermore, even for easily deformable materials such as fabrics, cloth, and leather that make up textile or leather products, temporary fixation using the adhesive thread according to the embodiment of the present invention can suppress or prevent deformation of the materials due to tension, resulting in excellent design after fixation (full fixation). Furthermore, the adhesive thread according to the embodiment of the present invention can be easily removed from between the two articles after fixation (full fixation) of the two articles, as needed. This prevents overflow of the adhesive and effectively prevents deterioration of the design due to discoloration of the remaining adhesive over time. Furthermore, the adhesive thread according to the embodiment of the present invention can be used as a dam material to prevent overflow of the adhesive or adhesive when applying the adhesive or adhesive to the object to be bonded (adherend). The dam material can be used, for example, to prevent the extrusion of sealing resin used in bonding optical panels. When using the adhesive threads as the dam material, the adhesive threads may be peeled off after the adhesive or pressure-sensitive adhesive has hardened, or may be left in place.

[0109] Furthermore, the thread-like adhesive material according to the embodiment of the present invention can be twisted together with threads made of other materials to form combined threads, or woven with threads or fabrics (including nonwoven fabrics and sheets) made of other materials to achieve a combination of functions.

[0110] [Laminate] The present invention also relates to a laminate of the above-mentioned thread-like adhesive material and an electronic device member. Examples of electronic device members include narrow bezels of mobile terminals such as mobile phones and smartphones, notebook PCs, earphones, headphones, speakers, thin displays, game consoles, digital cameras, electronic dictionaries, cables such as electric wires and optical fibers, LED fiber lights, and optical fiber sensors such as FBG. The laminate according to an embodiment of the present invention may be a bonded body in which multiple electronic device members are bonded together with a thread-like adhesive material.

[0111] As explained above, the present specification discloses the following. <1> A thread-like adhesive body comprising a core material and a pressure-sensitive adhesive coating the longitudinal surface of the core material, the pressure-sensitive adhesive containing a base polymer and particles, the tensile modulus of the particles being less than 100 times the tensile modulus of the base polymer. <2> A thread-like adhesive body according to <1>, having a breaking stress of greater than 150 MPa. <3> A thread-like adhesive body according to <1> or <2>, wherein the rubber hardness of the particles is Shore A75 or less. <4> A thread-like adhesive body according to any one of <1> to <3>, wherein the average particle size of the particles is 1 μm to 35 μm. <5> A thread-like adhesive body according to any one of <1> to <4>, comprising 3 to 30 parts by mass of the particles per 100 parts by mass of the base polymer. <6> The thread-like adhesive material according to any one of <1> to <5>, wherein the mass ratio of the adhesive to the core material (mass of adhesive / mass of core material) is 0.44 or more. <7> The thread-like adhesive material according to any one of <1> to <6>, wherein the core material is a multifilament yarn. <8> A laminate of the thread-like adhesive material according to any one of <1> to <7> and an electronic device member.

[0112] The present invention will be explained in more detail below by way of examples, but the present invention is not limited to the following examples in any way.

[0113] <Preparation of Acrylic Polymer Emulsion> (Preparation of Acrylic Polymer Emulsion 1) To a reaction vessel equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser, 0.07 parts by mass of a reactive surfactant (Aqualon KH-1025 / manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) and 61.1 parts by mass of distilled water were added, and the atmosphere was replaced with nitrogen at 60° C. for 1 hour with stirring. Thereafter, 0.10 parts by mass of a polymerization initiator (VA-057 / manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added thereto. To this was added dropwise over 4 hours at 60° C. an emulsion of 85 parts by mass of 2-ethylhexyl acrylate (2EHA), 13 parts by mass of methyl acrylate (MA), 1.25 parts by mass of acrylic acid (AA), 0.75 parts by mass of methacrylic acid (MAA), 0.025 parts by mass of t-dodecanethiol (chain transfer agent), 0.02 parts by mass of 3-methacryloxypropyltrimethoxysilane (KBM-503), and 1.93 parts by mass of the reactive surfactant described above in 28 parts by mass of distilled water, while allowing emulsion polymerization to proceed. After maintaining the temperature at 60° C. for 3 hours, 0.05 parts by mass of the polymerization initiator described above was added, and the mixture was further maintained at 60° C. for 2 hours. The system was cooled to room temperature (25°C), and the pH was adjusted to 7 using 10% aqueous ammonia as a pH adjuster. 0.0072 parts by mass of a preservative (Neosintol 2208, manufactured by Sumika Enviroscience Co., Ltd.) was added. In this manner, an aqueous dispersion of an acrylic polymer (acrylic polymer emulsion 1) was prepared. The solids concentration of this acrylic polymer was 50.5% by mass, and the sol weight-average molecular weight (Mw) was 340,000.

[0114] <Preparation of Pressure-Sensitive Adhesive Composition> (Preparation of Pressure-Sensitive Adhesive Composition 1) A tackifier resin emulsion (manufactured by Arakawa Chemical Industries, Ltd., trade name "Tamanol E200NT") was added so that the tackifier resin was 35 parts by mass per 100 parts by mass of the acrylic polymer contained in Acrylic Polymer Emulsion 1. Further, ion-exchanged water was added to dilute the solids concentration to 45% by mass, and then 10% by mass of ammonia water as a pH adjuster and polyacrylic acid (manufactured by Toagosei Co., Ltd., trade name "Aron B-500") as a thickener were used to adjust the pH and viscosity to be suitable for coating, thereby obtaining Pressure-Sensitive Adhesive Liquid 1. Silicone filler (manufactured by Dow-Toray Industries, Inc., trade name "BY29-119") was added to the above Pressure-Sensitive Adhesive Liquid 1 so that the particles (filler) were 10 parts by mass per 100 parts by mass of the acrylic polymer, and the mixture was stirred for 5 minutes at 2000 rpm. Air bubbles were removed using a centrifugal defoamer, thereby obtaining Pressure-Sensitive Adhesive Composition 1.

[0115] (Preparation of Pressure-Sensitive Adhesive Compositions 2 to 12) Pressure-Sensitive Adhesive Compositions 2 to 12 were obtained in the same manner as Pressure-Sensitive Adhesive Composition 1, except that the type and amount of filler added was changed as shown in Tables 1 to 3.

[0116] <Production of Thread-Like Adhesive Body> (Example 1) As a core material, a multifilament yarn was prepared by twisting 150 times per meter seven polyethylene terephthalate (PET) fibers (manufactured by Teijin Frontier Co., Ltd.) (fineness: 1169 dtex, number of filaments: 336) each having a fineness of 167 dtex and a number of filaments of 48. The core material was coated with PSA composition 1 by dipping using a coating roller. The coating was then dried at 100°C for 1 minute to obtain a thread-like adhesive body with a glue amount (adhesive amount) of 40 mg / 60 cm.

[0117] (Examples 2 to 15, Comparative Examples 1 to 4) Thread-like adhesive bodies were prepared in the same manner as in Example 1, except that the type of adhesive composition, the type of core material, and the amount of glue were changed as shown in Tables 1 to 3.

[0118] <Tensile modulus of base polymer (E ｐThe acrylic polymer emulsion 1 obtained above was applied to a release liner and dried in a hot air oven at 100°C for 2 minutes, thereby producing a 60µm thick pressure-sensitive adhesive layer (base polymer layer) on the release liner. A plurality of the obtained pressure-sensitive adhesive layers was stacked together to produce a pressure-sensitive adhesive layer with a thickness of approximately 2mm. This pressure-sensitive adhesive layer was punched into a disk shape with a diameter of 7.9mm, and the sample was sandwiched and fixed between parallel plates. Dynamic viscoelasticity was measured under the following conditions using a viscoelasticity tester (trade name "ARES Rheometer", manufactured by T.A. Instruments) at 23°C and 50% RH, to determine the storage modulus G ｐ ' (23°C) was calculated. It was confirmed that the peak top of tan δ was present in the range of -20 to 0°C. Measurement mode: Shear mode Temperature range: -70°C to 150°C Heating rate: 5°C / min Measurement frequency: 1 Hz

[0119] Next, the storage modulus (G ｐ '), and the tensile modulus of elasticity (E ｐ ') was calculated. ｐ '=E ｐ ' / 2(1+v) (1) In the above formula (1), v is the Poisson's ratio of the base polymer, which is set to 0.5 in this specification.

[0120] <Tensile modulus of the particles (E ｆ For the analytical samples, the particles used in the examples and comparative examples (all commercially available products were dispersions) were separated into the dispersion medium and particles using filter paper, dried, and the particles were fixed to a predetermined support to serve as measurement samples, and nanoindentation measurements were carried out. Apparatus: Triboindenter manufactured by Hysitron Inc. Indenter used: Berkovich (triangular pyramid) Measurement method: Single indentation measurement Measurement temperature: Room temperature (25°C) Indentation depth: 1500 nm

[0121] The tensile modulus (E ｐ '), the tensile modulus of the particles (E ｆ ') from E ｆ ' / E ｐ ' was calculated.

[0122] <Breaking Stress of Core Material> The breaking stress of the core material was measured using a universal tension and compression testing machine (product name "TCM-1kNB", manufactured by Minebea Co., Ltd.) under an environment of 23°C and 50% RH. A tensile test was performed on the core material under conditions of a chuck distance of 10 mm and a tensile speed of 50 mm / min to obtain an S-S curve and measure the stress at break (breaking stress). A sample was cut to a length of 30 mm, and 10 mm each of the top and bottom was fixed with a chuck.

[0123] <Breaking stress of thread-like adhesive body> The breaking stress of the thread-like adhesive body was measured using the same test method as for the breaking stress of the core material. A sample was cut out to a length of 30 mm, and the top and bottom ends of 10 mm were fixed with a chuck.

[0124] <Rubber Hardness of Particles> The rubber hardness of the particles was measured using a durometer hardness tester in accordance with JIS K6253.

[0125] [Evaluation] The obtained thread-like adhesive material was evaluated as follows, and the results are shown in Tables 1 to 3.

[0126] <Impact Resistance> The impact resistance of the thread-like adhesive was evaluated using a DuPont drop impact tester (manufactured by Toyo Seiki Seisakusho) using the following method. First, a first member and a second member were prepared as shown below. First member: a 25 mm square SUS304 plate. Second member: a 50 mm square SUS304 plate with a 20 mm square slit in the center. Next, a thread-like adhesive cut to a length of 330 mm was attached to the first member on all four sides along the frame with a width of 2 mm. The first member and the second member were then bonded together so that the center of the first member and the center of the slit in the second member were aligned, and the bonded members were pressure-bonded at 0.35 MPa for 10 seconds, heat-treated at 60°C for 1 hour, and returned to room temperature (25°C) to obtain a bonded assembly. Using a DuPont impact tester, the weight mass and height of the drop on the evaluation sample were changed from 50 to 500 mm in 50 mm increments with a drop weight of 50 g, and the energy was increased until peeling occurred. The energy at which at least one of the stainless steel plates peeled off was then calculated using the following formula: Energy (J) = (weight mass (kg)) x (drop height (m)) x 9.8

[0127] <Pull-out disassembly> A square acrylic plate (one side: 70 mm, thickness: 3 mm) and a 5 cm thread-like adhesive were prepared. The thread-like adhesive was attached to the acrylic plate so that 1 cm of the thread-like adhesive protruded from the acrylic plate. An acrylic plate of the same shape was then placed on top of the thread-like adhesive and pressed at 0.3 MPa for 20 seconds to obtain a bonded structure. The protruding thread-like adhesive was pulled in a direction perpendicular to the longitudinal direction of the thread-like adhesive, and evaluated according to the following criteria. ◯: The thread-like adhesive could be pulled out without breaking the core material. ×: The core material was broken when pulling out the thread-like adhesive, or the thread-like adhesive could not be pulled out.

[0128] In the following Tables 1 to 3, the column for base polymer shows the type and amount (parts by mass) of each monomer constituting the base polymer.

[0129]

[0130]

[0131]

[0132] The particles (fillers) shown in Tables 1 to 3 are as follows: BY29-119: manufactured by Dow-Toray Industries, Inc., trade name "BY29-119", average particle size 4 μm, silicone filler G515: manufactured by Sumitomo Seika Chemicals Co., Ltd., trade name "Sepolsion G515", average particle size 1.5 μm, polyethylene filler 33Additive: manufactured by Dow-Toray Industries, Inc., trade name "33Additive", average particle size 3 μm, silicone filler X-52-1133: manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-52-1133", average particle size 5 μm, silicone filler KMP-601: manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KMP-601", average particle size 12 μm, silicone resin filler KMP-602: Shin-Etsu Chemical Co., Ltd., trade name "KMP-602", average particle size 30 μm, silicone resin filler Flow Beads EA: Sumitomo Seika Chemicals Co., Ltd., trade name "Flow Beads EA209", average particle size 11 μm, polyethylene filler PA200: Sumitomo Seika Chemicals Co., Ltd., trade name "Sepolsion PA200", average particle size 0.5 μm, polyamide filler

[0133] The core materials shown in Tables 1 to 3 are as follows: Core 1: A multifilament yarn made of seven polyethylene terephthalate (PET) fibers (manufactured by Teijin Frontier Co., Ltd.) with a fineness of 167 dtex and a filament count of 48 (fibers) (fineness: 1,169 dtex, filaments: 336) twisted 150 times per meter. Core 2: A multifilament yarn made of one polyethylene terephthalate (PET) fiber (manufactured by Teijin Frontier Co., Ltd.) with a fineness of 167 dtex and a filament count of 48 (filaments) (fineness: 167 dtex, filaments: 48) twisted 200 times per meter. Core 3: A multifilament yarn made of one polyurethane fiber (manufactured by Toray Industries, Inc.) with a fineness of 940 dtex and a filament count of 127 (fineness: 940 dtex, filaments: 127). Core material 4: A multifilament yarn made by twisting 150 turns per meter 14 strands (fineness: 1176 dtex, number of filaments: 504) of polylactic acid fiber (manufactured by Unitika Ltd., product name "Terramac 84T36 processed yarn") with a fineness of 84 dtex and a number of 36 filaments. Core material 5: A multifilament yarn made by twisting 150 turns per meter 16 strands (fineness: 1216 dtex, number of filaments: 3456) of polyethylene terephthalate (PET) fiber (manufactured by Teijin Frontier Co., Ltd.) with a fineness of 76 dtex and a number of 216 filaments.

[0134] The results shown in Tables 1 to 3 indicate that the thread-like adhesive bodies of Examples 1 to 15 have excellent impact resistance and excellent pull-out dismantling properties. In contrast, the thread-like adhesive bodies of Comparative Examples 1 and 2, which do not contain a filler in the adhesive layer, and the thread-like adhesive bodies of Comparative Examples 3 and 4, in which the tensile modulus of the filler is outside the specified range, have poor impact resistance.

[0135] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0136] The adhesive thread of the present invention can provide an adhesive thread having excellent impact resistance and excellent pull-out dismantling properties. Also, a laminate of the adhesive thread and an electronic device member can be provided.

[0137] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2024-057292) filed on March 29, 2024, the contents of which are incorporated herein by reference.

Claims

1. A thread-like adhesive body comprising a core material and an adhesive coating the longitudinal surface of the core material, the adhesive containing a base polymer and particles, and the tensile modulus of the particles being less than 100 times the tensile modulus of the base polymer.

2. The thread-like adhesive material according to claim 1, having a breaking stress of greater than 150 MPa.

3. The thread-like adhesive material according to claim 1, wherein the rubber hardness of the particles is Shore A75 or less.

4. The thread-like adhesive material according to claim 1, wherein the particles have an average particle size of 1 μm to 35 μm.

5. The thread-like adhesive body according to claim 1, comprising 3 to 30 parts by weight of the particles per 100 parts by weight of the base polymer.

6. The thread-like adhesive body according to claim 1, wherein the mass ratio of the adhesive to the core material (mass of adhesive / mass of core material) is 0.44 or more.

7. The thread-like adhesive body according to claim 1, wherein the core material is a multifilament thread.

8. A laminate of the thread-like adhesive material according to any one of claims 1 to 7 and an electronic device member.

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