Double-sided pressure-sensitive adhesive tape

Abstract

The present invention relates to a double-sided pressure-sensitive adhesive tape. A double-sided pressure-sensitive adhesive tape that can exhibit excellent impact resistance is provided. The double-sided pressure-sensitive adhesive tape is a double-sided pressure-sensitive adhesive tape for fixing a member included in a mobile device, the double-sided pressure-sensitive adhesive tape includes a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition, and wherein the pressure-sensitive adhesive composition contains an organic hollow filler.

Description

Technical Field

[0001] The present invention relates to a double-sided pressure-sensitive adhesive tape. Background Art

[0002] In recent years, with the trend of various performances of mobile devices becoming more complicated, various performances of various constituent members used in mobile devices have been required to be complicated. In mobile devices, double-sided pressure-sensitive adhesive tapes are sometimes used for joining of housings, etc. In recent years, various performances of double-sided pressure-sensitive adhesive tapes have also been required to be complicated.

[0003] Mobile devices have a risk of falling depending on their usage forms. Therefore, mobile devices with high impact resistance have been required. Impact absorbing members are sometimes provided outside the housing of the mobile device to improve the impact resistance of the mobile device. However, in this form, the size of the mobile device may increase or its designability may be impaired.

[0004] In view of the foregoing, it is desirable to impart excellent impact resistance to a double-sided pressure-sensitive adhesive tape that can be provided in a mobile device.

[0005] Recently, a double-sided pressure-sensitive adhesive sheet with impact resistance has been reported (Japanese Patent Application Laid-Open No. 2015-120876). The double-sided pressure-sensitive adhesive sheet includes a substrate made of a foam as an essential component to exhibit impact resistance. However, when the foam is extended to a certain extent or a force is applied to it, the foam is cut off, thereby having a smaller area or becoming thinner. As a result, there is the following problem: the cell portion of the foam occupies most of the bonding portion between the sheet and the adherend, thereby reducing the adhesion between them. Summary of the invention

[0006] An object of the present invention is to provide a double-sided pressure-sensitive adhesive tape which can exhibit excellent impact resistance.

[0007] According to at least one embodiment of the present invention, there is provided a double-sided pressure-sensitive adhesive tape for fixing a member included in a mobile device, the double-sided pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition, and wherein the pressure-sensitive adhesive composition contains an organic-based hollow filler.

[0008] In at least one embodiment of the present invention, the specific gravity of the organic hollow filler is 0.01 to 1.2.

[0009] In at least one embodiment of the present invention, the average particle size of the organic hollow filler is 5 μm to 70 μm.

[0010] In at least one embodiment of the present invention, the organic hollow filler is an acrylonitrile hollow filler.

[0011] In at least one embodiment of the present invention, the double-sided pressure-sensitive adhesive tape has a thickness of 100 μm or more.

[0012] In at least one embodiment of the present invention, the pressure-sensitive adhesive composition comprises at least one selected from a monomer component (m) and a polymer component (P) obtained by polymerizing the monomer component (m), and the monomer component (m) comprises an alkyl (meth)acrylate having an alkyl group having 4 to 18 carbon atoms at its ester terminal.

[0013] In at least one embodiment of the present invention, the content of the alkyl (meth)acrylate having an alkyl group of 4 to 18 carbon atoms at its ester terminal in the monomer component (m) is 50 wt % to 100 wt %.

[0014] In at least one embodiment of the present invention, the double-sided pressure-sensitive adhesive tape is used for fixing one of a display portion and a display portion protection member to a housing in the mobile device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic cross-sectional view of a double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention.

[0016] Figure 2 This is a photograph of a cross section of the double-sided pressure-sensitive adhesive tape (1) obtained in Example 1, which was taken using a scanning electron microscope (S-3400N manufactured by Hitachi High-Technologies Corporation). DETAILED DESCRIPTION

[0017] As used herein, the term "(meth)acryl" refers to at least one selected from acrylic and methacrylic, and the term "(meth)acrylate" refers to at least one selected from acrylate and methacrylate.

[0018] 《A. Double-sided pressure-sensitive adhesive tape》

[0019] A double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention includes a pressure-sensitive adhesive layer.

[0020] The pressure-sensitive adhesive layer may be a single-layer pressure-sensitive adhesive layer formed of only one layer of pressure-sensitive adhesive layer, or may be a pressure-sensitive adhesive layer laminate obtained by laminating "n" or more pressure-sensitive adhesive layers.

[0021] The symbol “n” represents an integer of 2 or more, preferably an integer of 2-5, more preferably an integer of 2-4, and still more preferably an integer of 2 or 3.

[0022] The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention preferably includes a pressure-sensitive adhesive layer laminate obtained by laminating “n” or more pressure-sensitive adhesive layers, since the tape can exhibit more excellent impact resistance.

[0023] The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention preferably includes a pressure-sensitive adhesive layer stack with (n-1) interfaces. The interface objectively shows that the pressure-sensitive adhesive layer stack is formed by stacking more than "n" layers of pressure-sensitive adhesive layers. The interface can be observed by a differential interferometer such as LEXT OLS 4000 manufactured by Olympus Corporation.

[0024] The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention may include any suitable other layer within such a range that the effect of the present invention is not impaired, as long as the tape includes a pressure-sensitive adhesive layer laminate formed by laminating "n" or more pressure-sensitive adhesive layers. The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention is preferably formed of a pressure-sensitive adhesive layer laminate formed by laminating "n" or more pressure-sensitive adhesive layers, because the effect of the present invention can be further exhibited.

[0025] The thickness of the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention is preferably 100 μm or more because the effects of the present invention can be further expressed, and is more preferably 100 to 1,000 μm, still more preferably 100 to 500 μm, particularly preferably 100 to 300 μm.

[0026] Figure 1 is a schematic cross-sectional view of a double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention. Figure 1 In the embodiment of the present invention, the double-sided pressure-sensitive adhesive tape 100 is formed of three pressure-sensitive adhesive layers, and includes a pressure-sensitive adhesive layer 10 a , a pressure-sensitive adhesive layer 10 b , and a pressure-sensitive adhesive layer 10 c .

[0027] Within such a range that does not impair the effects of the present invention, any suitable release liner can be provided on the surface of the pressure-sensitive adhesive layer, thereby protecting the tape until it is used, for example. Examples of the release liner include: a release liner including a release treatment layer on the surface of a substrate (liner substrate) such as paper or a plastic film; a fluorine-based polymer (e.g., polytetrafluoroethylene); and a release liner obtained by laminating a polyolefin-based resin on the surface of a substrate (liner substrate) such as paper or a plastic film. Examples of the plastic film as the liner substrate include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film. The plastic film as the liner substrate is preferably a polyethylene film. The release treatment layer can be formed by subjecting the liner substrate to a surface treatment with a release treatment agent such as a silicone-based release treatment agent, a long-chain alkyl-based release treatment agent, a fluorine-based release treatment agent, or molybdenum disulfide.

[0028] The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, still more preferably 5 μm to 400 μm, and particularly preferably 10 μm to 300 μm.

[0029] The pressure-sensitive adhesive strength of the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention is preferably 5 N / 10 mm to 50 N / 10 mm, more preferably 6 N / 10 mm to 40 N / 10 mm, still more preferably 7 N / 10 mm to 30 N / 10 mm, and particularly preferably 8 N / 10 mm to 20 N / 10 mm. When the pressure-sensitive adhesive strength of the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention falls within the above range, the function as a double-sided pressure-sensitive adhesive tape can be fully exhibited.

[0030] <A-1. Pressure-sensitive adhesive layer laminate>

[0031] The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention may include a pressure-sensitive adhesive layer laminate. The pressure-sensitive adhesive layer laminate is formed by laminating "n" or more pressure-sensitive adhesive layers.

[0032] All of the "n" pressure-sensitive adhesive layers forming the pressure-sensitive adhesive layer laminate may be pressure-sensitive adhesive layers having the same composition, or at least one of the layers may be a pressure-sensitive adhesive layer different in composition from the other layers.

[0033] The thickness of the pressure-sensitive adhesive layer laminate is preferably 100 μm or more because the effects of the present invention can be further exhibited, and this thickness is more preferably 100 μm to 1,000 μm, still more preferably 100 μm to 500 μm, and particularly preferably 100 μm to 300 μm.

[0034] <A-2. Pressure-sensitive adhesive layer>

[0035] Each of the pressure-sensitive adhesive layers includes a pressure-sensitive adhesive. Within such a range that does not impair the effects of the present invention, any suitable pressure-sensitive adhesive can be used as the type of pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer. Such a pressure-sensitive adhesive can be a pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition. As the base polymer (the main component among the polymer components, that is, the component accounting for 50 wt% or more of the composition), the pressure-sensitive adhesive composition contains one or more selected from the group consisting of various polymers (pressure-sensitive adhesive polymers) such as acrylic polymers, polyester polymers, polyurethane polymers, polyether polymers, rubber polymers, silicone polymers, polyamide polymers, and fluorine polymers.

[0036] Each of the pressure-sensitive adhesive layers is formed from a pressure-sensitive adhesive composition.

[0037] Each of the pressure-sensitive adhesive layers is formed from a pressure-sensitive adhesive composition by any suitable method. Examples of such a method include: a method (direct method) involving coating a pressure-sensitive adhesive composition, which is a forming material for the pressure-sensitive adhesive layer, onto any suitable substrate (e.g., a substrate film) and drying the composition as needed to form a pressure-sensitive adhesive layer on the substrate; and a method (transfer method) involving coating a pressure-sensitive adhesive composition onto a surface having peelability (peel surface), drying the composition as needed to form a pressure-sensitive adhesive layer on the surface having peelability (peel surface), and transferring the pressure-sensitive adhesive layer onto any suitable substrate (e.g., a substrate film). The surface having peelability (peel surface) is, for example, the surface of the aforementioned release liner.

[0038] Within such a range that does not impair the effects of the present invention, any suitable coating method can be used as the coating method for the pressure-sensitive adhesive composition. Examples of such a coating method include roll coating, gravure coating, reverse coating, roll brushing, spraying, air knife coating, and extrusion coating using a die coater, etc. Actinic ray irradiation such as UV irradiation can be performed to cure the coating layer formed by coating.

[0039] From the viewpoints of, for example, promoting the crosslinking reaction of the composition and improving the production efficiency of the tape, drying of the pressure-sensitive adhesive composition can be carried out under heating. The drying temperature can typically be set to, for example, 40°C to 150°C, and preferably 60°C to 130°C. After drying the pressure-sensitive adhesive composition, aging can be further carried out for the purposes of, for example, regulating the migration of components within the pressure-sensitive adhesive layer, promoting the crosslinking reaction, and relieving the strain that may exist within the pressure-sensitive adhesive layer.

[0040] The thickness of each pressure-sensitive adhesive layer can be appropriately set according to the thickness of the finally formed pressure-sensitive adhesive layer laminate and the number of pressure-sensitive adhesive layers. Such a thickness of each pressure-sensitive adhesive layer is preferably 10 μm to 1,000 μm, more preferably 20 μm to 700 μm, still more preferably 30 μm to 500 μm, particularly preferably 40 μm to 300 μm, and most preferably 50 μm to 200 μm.

[0041] The light transmittance of each pressure-sensitive adhesive layer in the XY direction and the Z direction is preferably 5% or less, more preferably 3% or less, still more preferably 1% or less, still further more preferably 0.5% or less, particularly preferably 0.1% or less, and most preferably 0.04% or less. When the light transmittance of each pressure-sensitive adhesive layer in the XY direction and the Z direction falls within the above ranges, the pressure-sensitive adhesive layer can exhibit excellent light-shielding properties. The light transmittance of each pressure-sensitive adhesive layer in the XY direction is preferably 0.03% or less, more preferably 0.02% or less, still more preferably 0.01% or less. The light transmittance of each pressure-sensitive adhesive layer in the Z direction is preferably 0.03% or less, more preferably 0.02% or less, still more preferably 0.01% or less.

[0042] <A-2-1. Pressure-Sensitive Adhesive Composition>

[0043] The pressure-sensitive adhesive composition contains an organic hollow filler. The number of types of organic hollow fillers in the pressure-sensitive adhesive composition can be only 1 type, or can be 2 types or more. When the pressure-sensitive adhesive composition contains an organic hollow filler, a double-sided pressure-sensitive adhesive tape that can exhibit excellent impact resistance can be provided.

[0044] The pressure-sensitive adhesive composition preferably contains at least one selected from a monomer component (m) and a polymer component (P) obtained by polymerizing the monomer component (m). That is, typically, the pressure-sensitive adhesive composition can preferably have any of the following forms: a form (form 1) containing the polymer component (P) and substantially free of the monomer component (m); a form (form 2) containing the monomer component (m) and substantially free of the polymer component (P); and a form (form 3) containing both the monomer component (m) and the polymer component (P).

[0045] The form (Form 1) comprising the polymer component (P) and substantially free of the monomer component (m) is a form in which the polymer component (P) is substantially formed by polymerizing the monomer component (m) at the preparation stage of the pressure-sensitive adhesive composition.

[0046] The form containing the monomer component (m) and substantially free of the polymer component (P) (Form 2) is a form in which polymerization of the monomer component (m) does not substantially occur at the stage of preparing the pressure-sensitive adhesive composition, and thus the polymer component (P) has not yet been formed. In this form, the polymer component (P) can be formed by, for example, curing a coating layer formed by coating the prepared pressure-sensitive adhesive composition by irradiation with active energy rays such as UV irradiation.

[0047] The form (form 3) containing both the monomer component (m) and the polymer component (P) is a form in which, at the stage of preparing the pressure-sensitive adhesive composition, a part of the molecules of the monomer component (m) is polymerized to form a partial polymer, and unreacted molecules of the monomer component (m) remain. In this form, the polymer component (P) can be formed by, for example, curing a coating layer formed by coating the prepared pressure-sensitive adhesive composition by irradiating it with active energy rays such as UV irradiation.

[0048] In the case of Form 1 (a form comprising the polymer component (P) and substantially free of the monomer component (m)), the content of the polymer component (P) in the pressure-sensitive adhesive composition is as follows: When the total amount of the pressure-sensitive adhesive composition is set to 100 parts by weight, the content of the polymer component (P) is preferably 50 wt% to 100 wt%, more preferably 60 wt% to 100 wt%, still more preferably 70 wt% to 100 wt%, particularly preferably 80 wt% to 100 wt%.

[0049] In the case of Form 2 (a form comprising the monomer component (m) and substantially free of the polymer component (P)), the content of the monomer component (m) in the pressure-sensitive adhesive composition is as follows: When the total amount of the pressure-sensitive adhesive composition is set to 100 parts by weight, the content of the monomer component (m) is preferably 50 wt% to 100 wt%, more preferably 60 wt% to 100 wt%, still more preferably 70 wt% to 100 wt%, particularly preferably 80 wt% to 100 wt%.

[0050] In the case of Form 3 (a form containing both monomer component (m) and polymer component (P)), the total content of the polymer component (P) and the monomer component (m) in the pressure-sensitive adhesive composition is as follows: When the total amount of the pressure-sensitive adhesive composition is set to 100 parts by weight, the total content of the polymer component (P) and the monomer component (m) is preferably 50wt% to 100wt%, more preferably 60wt% to 100wt%, still more preferably 70wt% to 100wt%, and particularly preferably 80wt% to 100wt%.

[0051] The pressure-sensitive adhesive composition may contain any appropriate colorant within such a range that the effects of the present invention are not impaired, from the viewpoint of, for example, adjusting its light transmittance (light shielding property). Conventionally known pigments or dyes may be used as such a colorant. Examples of the pigment include: inorganic pigments such as carbon black, zinc carbonate, zinc oxide, zinc sulfide, talc, kaolin, calcium carbonate, titanium oxide, silicon dioxide, lithium fluoride, calcium fluoride, barium sulfate, aluminum oxide, zirconium oxide, iron oxide pigments, iron hydroxide pigments, chromium oxide pigments, spinel-type calcined pigments, chromic acid pigments, chrome vermilion-based pigments, iron blue pigments, aluminum powder pigments, bronze powder pigments, silver powder pigments, and calcium phosphate; and organic pigments such as phthalocyanine pigments, azo pigments, condensed azo pigments, azo lake pigments, anthraquinone pigments, perinone pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, azomethine pigments, dioxazine pigments, quinacridone pigments, nigrosine pigments, and triphenylmethane pigments. Examples of the dye include azo dyes, anthraquinone, quinophthalone, styryl dyes, diphenylmethane, triphenylmethane, oxazine, triazine, xanthan gum, azomethine, acridine, and dioxazines. The number of kinds of the colorant may be only one, or two or more.

[0052] Specific examples of the black colorant include carbon black, graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (e.g., non-magnetic ferrite or magnetic ferrite), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complexes, and anthraquinone-based colorants.

[0053] The content of the colorant in the pressure-sensitive adhesive composition is preferably less than 30 wt%, more preferably less than 20 wt%, still more preferably less than 13 wt%, particularly preferably less than 10 wt%, most preferably less than 8 wt%.

[0054] Within such a range that does not impair the effects of the present invention, the pressure-sensitive adhesive composition may contain any suitable other components. Examples of such other components include resin components other than the polymer component (P), tackifiers, crosslinking agents, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, UV absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, and catalysts.

[0055] <A-2-1-1. Organic hollow filler>

[0056] The pressure-sensitive adhesive composition contains an organic hollow filler. When the pressure-sensitive adhesive composition contains an organic hollow filler, a double-sided pressure-sensitive adhesive tape that can exhibit excellent impact resistance can be provided.

[0057] The number of types of the organic hollow filler may be only 1 type, or may be 2 or more types.

[0058] The organic hollow filler is an organic filler having a hollow structure, and generally, for example, is at least one selected from organic hollow fillers and organic-inorganic hybrid hollow fillers formed of an organic and inorganic composite material.

[0059] The organic hollow filler is a hollow filler including an organic substance, and generally is a hollow filler including a polymer. Examples of monomers for forming such a polymer include acrylonitrile, vinyl chloride, vinylidene chloride, styrene, vinyl acetate, and (meth)acrylate. The organic hollow filler includes an organic substance as a main component (weight ratio preferably 50 wt% or more), and in addition, its surface may be coated with a powder (such as calcium carbonate, talc, or titanium oxide).

[0060] In a preferred embodiment of the present invention, the polymer forming the organic hollow filler is preferably one of a polymer obtained from a monomer containing acrylate (acrylate polymer) and a polymer obtained from a monomer containing acrylonitrile (acrylonitrile polymer), because the effects of the present invention can be further exhibited, and the polymer is more preferably a polymer obtained from a monomer containing acrylonitrile (acrylonitrile polymer). That is, in a preferred embodiment of the present invention, the organic hollow filler is preferably a hollow filler containing an acrylonitrile polymer (acrylonitrile-based hollow filler), because the effects of the present invention can be further exhibited.

[0061] Examples of the hollow filler formed of acrylonitrile include MATSUMOTO MICROSPHERE F-35, MATSUMOTO MICROSPHERE F-65, MATSUMOTO MICROSPHERE FN-80SDE, and MATSUMOTO MICROSPHERE MFL-81GCA manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., and Expancel 053 40 and Expancel 551DE 40d42 manufactured by Nouryon.

[0062] The specific gravity of the organic hollow filler is preferably 0.01 to 1.20, more preferably 0.02 to 1.10, still more preferably 0.05 to 1.00, still more preferably 0.08 to 0.80, particularly preferably 0.10 to 0.50, and most preferably 0.12 to 0.30, because the effects of the present invention can be further exhibited.

[0063] The average particle size of the organic hollow filler is preferably 5 to 70 μm, more preferably 7 to 60 μm, still more preferably 10 to 50 μm, particularly preferably 12 to 40 μm, most preferably 15 to 35 μm, because the effects of the present invention can be further exhibited.

[0064] The heat resistance of the organic hollow filler is preferably 100° C. or higher, more preferably 110° C. to 150° C., still more preferably 115° C. to 140° C., particularly preferably 120° C. to 140° C., because the effects of the present invention can be further exhibited.

[0065] In the case of Form 1 (a form comprising a polymer component (P) and substantially free of a monomer component (m)), the content of the organic hollow filler in the pressure-sensitive adhesive composition is as follows: when the total amount of the polymer component (P) is set to 100 parts by weight, the content of the organic hollow filler is preferably 0.05 wt% to 50 wt%, more preferably 0.1 wt% to 40 wt%, particularly preferably 1 wt% to 30 wt%, and most preferably 1 wt% to 20 wt%.

[0066] In the case of Form 2 (a form comprising monomer component (m) and substantially free of polymer component (P)), the content of the organic hollow filler in the pressure-sensitive adhesive composition is as follows: when the total amount of the monomer component (m) is set to 100 parts by weight, the content of the organic hollow filler is preferably 0.05 wt% to 50 wt%, more preferably 0.1 wt% to 40 wt%, particularly preferably 1 wt% to 30 wt%, and most preferably 1 wt% to 20 wt%.

[0067] In the case of Form 3 (the form containing both the monomer component (m) and the polymer component (P)), the content of the organic hollow filler in the pressure-sensitive adhesive composition is as follows: when the total amount of the sum of the polymer component (P) and the monomer component (m) is set to 100 parts by weight, the content of the organic hollow filler is preferably 0.05 wt% to 50 wt%, more preferably 0.1 wt% to 40 wt%, particularly preferably 1 wt% to 30 wt%, and most preferably 1 wt% to 20 wt%.

[0068] <A-2-1-2. Monomer component (m)>

[0069] Within such a range that does not impair the effects of the present invention, any suitable monomer component can be used as the monomer component (m).

[0070] The monomer component (m) preferably includes an alkyl (meth)acrylate having an alkyl group having 4 to 18 carbon atoms at its ester terminal. The number of types of alkyl (meth)acrylates each having an alkyl group having 4 to 18 carbon atoms at its ester terminal may be only 1 type, or 2 or more types.

[0071] Specific examples of the alkyl (meth)acrylate having an alkyl group of 4 to 18 carbon atoms at its ester terminal include: alkyl (meth)acrylates each having a linear alkyl group of 4 to 18 carbon atoms at its ester terminal, such as n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, n-pentadecyl (meth)acrylate, n-hexadecyl (meth)acrylate, n-heptadecyl (meth)acrylate and n-octadecyl (meth)acrylate; and tert-butyl (meth)acrylate, , isobutyl (meth)acrylate, isoamyl (meth)acrylate, tert-amyl (meth)acrylate, neopentyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, 2-propylheptyl (meth)acrylate, isondecyl (meth)acrylate, isododecyl (meth)acrylate, isotridecyl (meth)acrylate, isomyristyl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, and isostearyl (meth)acrylate, each of which has a branched alkyl group with 4 to 18 carbon atoms at the ester terminal. Among these alkyl (meth)acrylates each having an alkyl group having 4 to 18 carbon atoms at the ester end thereof, alkyl (meth)acrylates having a linear alkyl group having 4 to 12 carbon atoms at the ester end thereof are preferred because more excellent impact resistance can be exhibited, and alkyl (meth)acrylates having a linear alkyl group having 4 to 8 carbon atoms at the ester end thereof are more preferred, and specifically, n-butyl (meth)acrylate is particularly preferred.

[0072] The content of the (meth)acrylic acid alkyl ester having an alkyl group having 4 to 18 carbon atoms at its ester terminal in the monomer component (m) is preferably 50 wt % to 100 wt %, more preferably 70 wt % to 99.5 wt %, still more preferably 90 wt % to 99 wt %, particularly preferably 91 wt % to 98 wt %, most preferably 92 wt % to 97 wt %. When the content of the (meth)acrylic acid alkyl ester having an alkyl group having 4 to 18 carbon atoms at its ester terminal in the monomer component (m) falls within the above range, a double-sided pressure-sensitive adhesive tape that can exhibit more excellent impact resistance can be provided.

[0073] Monomer component (m) preferably comprises (meth) acrylic acid, and more preferably comprises acrylic acid. The content of (meth) acrylic acid in the total amount of monomer component (m) is preferably 1wt% to 10wt%, more preferably 1wt% to 8wt%, still more preferably 2wt% to 7wt%, particularly preferably 2wt% to 6wt%, most preferably 2.5wt% to 5.5wt%. When the content of (meth) acrylic acid in monomer component (m) falls within the above range, a double-sided pressure-sensitive adhesive tape that can show more excellent impact resistance can be provided.

[0074] The monomer component (m) may contain any other monomer. The number of types of such other monomers may be only one, or two or more.

[0075] The content of other monomers in the total amount of monomer component (m) is preferably 0 wt% to 10 wt%, more preferably 0 wt% to 8 wt%, still more preferably 0 wt% to 6 wt%, particularly preferably 0 wt% to 4 wt%, most preferably 0 wt% to 2 wt%. When the content of other monomers in monomer component (m) is adjusted within the above range, a double-sided pressure-sensitive adhesive tape that can exhibit more excellent impact resistance can be provided.

[0076] Examples of other monomers include acrylic monomers containing an alicyclic structure, (meth)acrylic acid alkyl esters having an alkyl group of 1 to 3 carbon atoms at their ester ends, hydroxyl-containing monomers, carboxyl-containing monomers other than (meth)acrylic acid, nitrogen-containing cyclic structure monomers, cyclic ether group-containing monomers, glycol acrylate monomers, styrene-based monomers, amide group-containing monomers, amino group-containing monomers, imide group-containing monomers, vinyl ether monomers, silane-based monomers, and multifunctional monomers.

[0077] The acrylic monomer containing an alicyclic structure is preferably an acrylic monomer having a cyclic aliphatic hydrocarbon structure. The number of carbon atoms in the cyclic aliphatic hydrocarbon structure is preferably 3 or more, more preferably 6 to 24, still more preferably 6 to 18, and particularly preferably 6 to 12. Specific examples of such acrylic monomers containing an alicyclic structure include cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate.

[0078] Specific examples of the alkyl (meth)acrylate having an alkyl group of 1 to 3 carbon atoms at the ester terminal thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate.

[0079] Specific examples of hydroxyl-containing monomers include: hydroxyalkyl (meth)acrylates such as 2-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; hydroxyalkyl (meth)acrylates such as (4-hydroxymethylcyclohexyl)methyl (meth)acrylate; and other hydroxyl-containing monomers such as hydroxyethyl (meth)acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether. Among these hydroxyl-containing monomers, hydroxyalkyl (meth)acrylates are preferred because more excellent impact resistance can be exhibited, and hydroxyalkyl (meth)acrylates having a hydroxyalkyl group having 2 to 6 carbon atoms are more preferred, and 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate is even more preferred.

[0080] Specific examples of the carboxyl group-containing monomer other than (meth)acrylic acid include carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

[0081] Specific examples of monomers with nitrogen-containing cyclic structures include: lactam-based vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; vinyl-based monomers each having a nitrogen-containing heterocyclic ring such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholine; and (meth)acrylic monomers each containing a heterocyclic ring such as a morpholine ring, a piperidine ring, a pyrrolidine ring, or a piperazine ring (for example, N-acryloylmorpholine, N-acryloylpiperidine, N-methacryloylpiperidine, and N-acryloylpyrrolidine).

[0082] Specific examples of monomers containing cyclic ether groups include: monomers containing epoxy groups such as glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 4-hydroxybutyl glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and allyl glycidyl ether; and monomers containing oxetane groups such as 3-oxetanyl methyl (meth)acrylate, 3-methyl-oxetanyl methyl (meth)acrylate, 3-ethyl-oxetanyl methyl (meth)acrylate, 3-butyl-oxetanyl methyl (meth)acrylate, and 3-hexyl-oxetanyl methyl (meth)acrylate.

[0083] Specific examples of the diol-based acrylate monomer include polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate.

[0084] Specific examples of the styrene-based monomers include styrene and α-methylstyrene.

[0085] Specific examples of the amide group-containing monomer include acrylamide, methacrylamide, diethylacrylamide, N-vinylpyrrolidone, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N,N-diethylacrylamide, N,N-diethylmethacrylamide, N,N′-methylenebisacrylamide, N,N-dimethylaminopropylacrylamide, N,N-dimethylaminopropylmethacrylamide, diacetoneacrylamide, and N,N-hydroxyethylacrylamide.

[0086] Specific examples of the amino group-containing monomer include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate.

[0087] Specific examples of the imide group-containing monomer include cyclohexylmaleimide, isopropylmaleimide, N-cyclohexylmaleimide, and itaconimide.

[0088] Specific examples of the silane-based monomers include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloxydecyltrimethoxysilane, 10-acryloxydecyltrimethoxysilane, 10-methacryloxydecyltriethoxysilane, and 10-acryloxydecyltriethoxysilane.

[0089] Specific examples of the polyfunctional monomers include: ester compounds of polyols and (meth)acrylic acid such as (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate; vinyl (meth)acrylate; divinylbenzene; epoxy acrylate; polyester acrylate; polyurethane acrylate; butyl di(meth)acrylate; and hexyl di(meth)acrylate.

[0090] <A-2-1-3. Polymer Component (P)>

[0091] The polymer component (P) is obtained by polymerizing the monomer component (m). The polymer component (P) is typically an acrylic polymer. The number of types of the polymer component (P) can be only 1 type, or 2 or more types.

[0092] Within such a range that does not impair the effects of the present invention, any suitable manufacturing method can be used as the manufacturing method of the polymer component (P). Examples of such manufacturing methods include various radical polymerizations, and the various radical polymerizations include: solution polymerization; active energy ray polymerization such as UV polymerization; bulk polymerization; and emulsion polymerization. Within such a range that does not impair the effects of the present invention, any suitable polymerization conditions can be used as the polymerization conditions.

[0093] Within such a range that does not impair the effects of the present invention, any suitable polymerization structure can be used as the polymerization structure of the polymer component (P) to be obtained. Examples of such polymerization structures include random copolymers, block copolymers, and graft copolymers.

[0094] Within such a range that does not impair the effects of the present invention, any suitable additive can be used as an additive used in radical polymerization, such as a polymerization initiator, a chain transfer agent, or an emulsifier.

[0095] Polymerization solvents that can be used in solution polymerization, etc. are, for example, ethyl acetate or toluene. The number of types of the polymerization solvents can be only 1 type, or 2 or more types.

[0096] Typically, under reaction conditions of a temperature of about 50°C to about 70°C and a time of about 5 hours to about 30 hours, after adding a polymerization initiator, solution polymerization is carried out in a stream of an inert gas such as nitrogen.

[0097] Any appropriate thermal polymerization initiator can be used as the polymerization initiator that can be used in solution polymerization, etc., within such a range that the effects of the present invention are not impaired. The number of kinds of the polymerization initiator may be only one, or two or more. Examples of such polymerization initiators include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis(2-methylpropionic acid) dimethyl ester, 4,4′-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2′-azobis(2-amidinopropane) dihydrochloride, 2,2′-azobis[2-(5-methyl-2-imidazolin-2-yl)propane] dihydrochloride, 2,2′-azobis(2-methylpropionamidine) disulfate, 2,2′-azobis(N,N′-dimethyleneisobutylamidine), and 2,2′-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.), etc.; for example, peroxide initiators such as persulfates such as potassium persulfate and ammonium persulfate, di(2-ethylhexyl) peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, di-sec-butyl peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, di(4-methylbenzoyl peroxide), dibenzoyl peroxide, tert-butyl peroxyisobutyrate, 1,1-di(tert-hexylperoxy)cyclohexane, tert-butyl hydroperoxide, and hydrogen peroxide; and redox initiators such as a combination of a persulfate and sodium bisulfite, a combination of a peroxide and sodium ascorbate, each obtained by combining a peroxide with a reducing agent.

[0098] The amount of the polymerization initiator used is preferably 1 part by weight or less, more preferably 0.005 to 1 part by weight, still more preferably 0.01 to 0.7 parts by weight, and particularly preferably 0.02 to 0.5 parts by weight, relative to the total amount of 100 parts by weight of the monomer component (m), for example, the following reasons: the polymerization reaction can be effectively promoted.

[0099] Any suitable chain transfer agent may be used as the chain transfer agent within the scope of not impairing the effect of the present invention. The number of types of chain transfer agents may be only one, or two or more. Examples of such chain transfer agents include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol.

[0100] The amount of the chain transfer agent to be used is preferably 0.1 parts by weight or less relative to 100 parts by weight of the total amount of the monomer component (m), for example, the following reason: the polymerization reaction can be effectively promoted.

[0101] Any suitable emulsifier may be used as the emulsifier within such a range that the effect of the present invention is not impaired. The number of types of the emulsifier may be only one, or two or more. Examples of such emulsifiers include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, and sodium polyoxyethylene alkylphenyl ether sulfate; and nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene-polyoxypropylene block polymer.

[0102] From the viewpoint of polymerization stability and mechanical stability, the amount of the emulsifier used is preferably 5 parts by weight or less, more preferably 0.3 to 5 parts by weight, still more preferably 0.4 to 3 parts by weight, particularly preferably 0.5 to 1 part by weight, relative to 100 parts by weight of the total amount of the monomer component (m).

[0103] When UV polymerization is performed, it is preferred to use a photopolymerization initiator.

[0104] In this range without damaging the effect of the present invention, any suitable photopolymerization initiator can be used as the photopolymerization initiator. The number of types of photopolymerization initiators can be only one, or more than two. Examples of such photopolymerization initiators include benzoin ether photopolymerization initiators, acetophenone photopolymerization initiators, α-ketol photopolymerization initiators, aromatic sulfonyl chloride photopolymerization initiators, photoactive oxime photopolymerization initiators, benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, ketal photopolymerization initiators, thioxanthone photopolymerization initiators, and acylphosphine oxide photopolymerization initiators.

[0105] Specific examples of the benzoin ether-based photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one (for example, a commercially available product under the trade name "Irgacure 651" from BASF), and anisole methyl ether.

[0106] Specific examples of the acetophenone-based photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (e.g., a commercial product available under the trade name “Irgacure 184” from BASF), 4-phenoxydichloroacetophenone, 4-tert-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one (e.g., a commercial product available under the trade name “Irgacure 2959” from BASF), 2-hydroxy-2-methyl-1-phenyl-propane-1-one (e.g., a commercial product available under the trade name “DAROCUR 1173” from BASF), and methoxyacetophenone.

[0107] Specific examples of the α-ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)-phenyl]-2-hydroxy-2-methylpropane-1-one.

[0108] A specific example of the aromatic sulfonyl chloride-based photopolymerization initiator is 2-naphthalenesulfonyl chloride.

[0109] A specific example of the photoactive oxime-based photopolymerization initiator is 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime.

[0110] A specific example of the benzoin-based photopolymerization initiator is benzoin.

[0111] A specific example of the benzil-based photopolymerization initiator is benzil.

[0112] Specific examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenylketone.

[0113] A specific example of the ketal-based photopolymerization initiator is benzyl dimethyl ketal.

[0114] Specific examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0115] Specific examples of the acylphosphine-based photopolymerization initiator include bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-n-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)-(2-methylpropane-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropane-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-tert-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)cyclohexylphosphine oxide, bis(2,6-dimethoxybenzoyl)octylphosphine oxide, bis(2-methoxybenzoyl)(2-methylpropane-1-yl)phosphine oxide, -yl) phosphine oxide, bis(2-methoxybenzoyl)(1-methylpropane-1-yl) phosphine oxide, bis(2,6-diethoxybenzoyl)(2-methylpropane-1-yl) phosphine oxide, bis(2,6-diethoxybenzoyl)(1-methylpropane-1-yl) phosphine oxide, bis(2,6-dibutoxybenzoyl)(2-methylpropane-1-yl) phosphine oxide, bis(2,4-dimethoxybenzoyl)(2-methylpropane-1-yl) phosphine oxide, bis(2,4,6-trimethylbenzoyl)(2,4-dipentyloxyphenyl) phosphine oxide, bis(2,6-dimethoxybenzoyl)benzyl phosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropyl phosphine oxide, bis(2,6- bis(2,6-dimethoxybenzoyl)-2-phenylethylphosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diethylphenylphosphine oxide Phosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)isobutylphosphine oxide, 2,6-dimethoxybenzoyl-2,4,6-trimethylbenzoyl-n-butylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-butoxyphenylphosphine oxide, 1,10-bis[bis(2,4,6-trimethylbenzoyl)phosphine oxide] decane, and tri(2-methylbenzoyl)phosphine oxide.

[0116] From the viewpoint of, for example, exhibiting satisfactory polymerizability, the amount of the photopolymerization initiator used is preferably 5 parts by weight or less, more preferably 0.01 to 5 parts by weight, still more preferably 0.05 to 3 parts by weight, particularly preferably 0.05 to 1.5 parts by weight, and most preferably 0.1 to 1 part by weight, relative to 100 parts by weight of the total amount of the monomer component (m).

[0117] When UV polymerization is performed, polyfunctional (meth)acrylates are preferably used.

[0118] Any appropriate polyfunctional (meth)acrylate may be used as the polyfunctional (meth)acrylate within such a range that the effects of the present invention are not impaired. The number of types of the polyfunctional (meth)acrylate may be only one, or two or more. Specific examples of such multifunctional (meth)acrylates include: ester compounds of polyols and (meth)acrylic acid such as (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate; allyl (meth)acrylate; vinyl (meth)acrylate; divinylbenzene; epoxy acrylate; polyester acrylate; polyurethane acrylate; butyl di(meth)acrylate; and hexyl di(meth)acrylate.

[0119] From the viewpoint of, for example, exhibiting satisfactory crosslinking properties, the amount of the multifunctional (meth)acrylate used is preferably 5 parts by weight or less, more preferably 0.01 to 5 parts by weight, still more preferably 0.05 to 3 parts by weight, particularly preferably 0.05 to 1.5 parts by weight, and most preferably 0.1 to 1 part by weight, relative to 100 parts by weight of the total amount of the monomer component (m).

[0120] Any suitable UV polymerization method can be used as a method for UV polymerization within such a range that the effects of the present invention are not impaired. Such UV polymerization method is, for example, as follows: the monomer component (m) is compounded with a photopolymerization initiator and, if necessary, a multifunctional (meth)acrylate, and the resultant is irradiated with UV light.

[0121] The weight-average molecular weight of the polymer component (P) is preferably from 100,000 to 3,000,000, more preferably from 300,000 to 2,000,000, still more preferably from 500,000 to 1,500,000, and particularly preferably from 500,000 to 1,000,000, because the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit more excellent impact resistance. The weight-average molecular weight is a value measured by gel permeation chromatography (GPC) and converted to polystyrene. It may be difficult to measure the weight-average molecular weight of the polymer component (P) obtained by living energy ray polymerization.

[0122] <A-2-1-4. Tackifying resin>

[0123] The pressure-sensitive adhesive composition may contain a tackifying resin. The number of types of the tackifying resin may be only 1 type, or 2 or more types.

[0124] Within such a range that does not impair the effects of the present invention, any suitable tackifying resin can be used as the tackifying resin. Examples of such a tackifying resin include phenolic tackifying resins, terpene tackifying resins, modified terpene tackifying resins, rosin tackifying resins, hydrocarbon tackifying resins, epoxy tackifying resins, polyamide tackifying resins, elastomeric tackifying resins, and ketone tackifying resins.

[0125] Examples of the phenolic tackifying resin include terpene-phenol resins, hydrogenated terpene-phenol resins, alkylphenol-formaldehyde resins, and rosin-phenol resins. The terpene-phenol resin refers to a polymer containing terpene residues and phenol residues, and is a concept including both a copolymer of terpenes and phenol compounds (terpene-phenol copolymer resin) and a phenol-modified product of a homopolymer or copolymer of terpenes (phenol-modified terpene resin). Examples of the terpenes forming such a terpene-phenol resin include monoterpenes such as α-pinene, β-pinene, and limonene (including d-type, l-type, and d / l-type (dipentene)). The hydrogenated terpene-phenol resin refers to a hydrogenated terpene-phenol resin having a structure obtained by hydrogenating such a terpene-phenol resin, and is sometimes referred to as a hydrogenated terpene-phenol resin. The alkylphenol-formaldehyde resin is a resin obtained from an alkylphenol and formaldehyde (oil-soluble phenolic resin). Examples of the alkylphenol-formaldehyde resin include novolak-type resins and resole-type resins. Examples of the rosin-phenol resin include phenol-modified products of rosins or various rosin derivatives (including rosin esters, unsaturated fatty acid-modified rosins, and unsaturated fatty acid-modified rosin esters). The rosin-phenol resin is, for example, a rosin-phenol resin obtained by a method involving adding phenol to a rosin or various rosin derivatives with an acid catalyst and thermally polymerizing the resulting product.

[0126] Examples of terpene-based tackifying resins include polymers of terpenes (typically monoterpenes) such as α-pinene, β-pinene, d-limonene, l-limonene and dipentene. A terpene homopolymer is, for example, an α-pinene polymer, a β-pinene polymer or a dipentene polymer.

[0127] Examples of the modified terpene resin include styrene-modified terpene resins and hydrogenated terpene resins.

[0128] The concept of rosin-based tackifying resins includes both rosins and rosin derivative resins. Examples of rosins include: unmodified rosins (raw rosins) such as gum rosin, wood rosin, and tall oil rosin; and modified rosins obtained by modifying these unmodified rosins by hydrogenation, disproportionation, or polymerization (e.g., hydrogenated rosin, disproportionated rosin, polymerized rosin, and any other chemically modified rosin).

[0129] Examples of rosin derivative resins include: rosin esters such as unmodified rosin esters as esters of unmodified rosin and alcohols, and modified rosin esters as esters of modified rosin and alcohols; unsaturated fatty acid-modified rosins obtained by modifying rosins with unsaturated fatty acids; unsaturated fatty acid-modified rosin esters obtained by modifying rosin esters with unsaturated fatty acids; rosin alcohols obtained by subjecting rosins or rosin derivative resins (e.g., rosin esters, unsaturated fatty acid-modified rosins, and unsaturated fatty acid-modified rosin esters) to reduction treatment; and metal salts thereof. Examples of rosin esters include methyl esters, triethylene glycol esters, glycerol esters, and pentaerythritol esters of unmodified rosins or modified rosins (e.g., hydrogenated rosin, disproportionated rosin, and polymerized rosin).

[0130] Examples of hydrocarbon-based tackifying resins include aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aliphatic-aromatic petroleum resins (e.g., styrene-olefin copolymers), aliphatic-alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone-based resins, and coumarone-indene-based resins.

[0131] In the case of Form 1, the content of the tackifying resin in the pressure-sensitive adhesive composition is preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight, still more preferably 8 to 25 parts by weight, and particularly preferably 10 to 20 parts by weight, relative to 100 parts by weight of the polymer component (P).

[0132] In the case of Form 2, the content of the tackifier resin in the pressure-sensitive adhesive composition is preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight, still more preferably 8 to 25 parts by weight, and particularly preferably 10 to 20 parts by weight, relative to 100 parts by weight of the total amount of the monomer component (m).

[0133] In the case of Form 3, based on the total amount of 100 parts by weight of the polymer component (P) and the monomer component (m), the content of the tackifier resin in the pressure-sensitive adhesive composition is preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight, still more preferably 8 to 25 parts by weight, and particularly preferably 10 to 20 parts by weight.

[0134] <A-2-1-5. Crosslinking agent>

[0135] The pressure-sensitive adhesive composition may contain a crosslinking agent. The number of types of crosslinking agents may be only 1 type, or 2 or more types. When the pressure-sensitive adhesive composition contains a crosslinking agent, the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit excellent oil resistance in addition to excellent impact resistance.

[0136] Within such a range that does not impair the effects of the present invention, any suitable crosslinking agent can be used as the crosslinking agent. Examples of such crosslinking agents include isocyanate-based crosslinking agents and non-isocyanate-based crosslinking agents.

[0137] Within such a range that does not impair the effects of the present invention, any suitable isocyanate-based crosslinking agent can be used as the isocyanate-based crosslinking agent. Examples of such isocyanate-based crosslinking agents include aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates, as well as dimers and trimers of those diisocyanates. Specific examples thereof include toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, and m-tetramethylxylylene diisocyanate, as well as their dimers and trimers, and polyphenylmethane polyisocyanate. In addition, the trimer may be, for example, an isocyanurate type, a biuret type, or a urethane type.

[0138] Commercially available products can be used as isocyanate-based crosslinking agents. Examples of commercially available products of polyisocyanates include products available under the trade name "TAKENATE 600" from Mitsui Chemicals, Inc., products available under the trade name "DURANATE TPA100" from Asahi Kasei Chemicals Corporation, and products available under the trade names "CORONATE L", "CORONATE HL", "CORONATE HK", "CORONATE HX" and "CORONATE 2096" from Nippon Polyurethane Industry Co., Ltd.

[0139] Examples of non-isocyanate crosslinking agents include epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, carbodiimide crosslinking agents, hydrazine crosslinking agents, amine crosslinking agents, peroxide crosslinking agents, metal chelate crosslinking agents, metal alkoxide crosslinking agents, metal salt crosslinking agents, and silane coupling agents.

[0140] In a preferred embodiment, an epoxy crosslinking agent may be used as the non-isocyanate crosslinking agent. The epoxy crosslinking agent is preferably a compound having 2 or more epoxy groups in its molecule, and more preferably an epoxy crosslinking agent having 3 to 5 epoxy groups in its molecule.

[0141] Specific examples of epoxy crosslinking agents include N, N, N', N'-tetraglycidyl-m-xylenediamine, 1,3-bis(N, N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, and polyglycerol polyglycidyl ether. Examples of commercially available epoxy crosslinking agents include products available under the trade names "TETRAD-C" and "TETRAD-X" from Mitsubishi Gas Chemical Company, products available under the trade name "EPICLON CR-5L" from DIC Corporation, products available under the trade name "DENACOL EX-512" from Nagase ChemteX Corporation, and products available under the trade name "TEPIC-G" from Nissan Chemical Industries, Ltd.

[0142] In the case of Form 1, the content of the crosslinking agent in the pressure-sensitive adhesive composition is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, still more preferably 0.5 to 7 parts by weight, and particularly preferably 1.5 to 3.5 parts by weight, based on 100 parts by weight of the polymer component (P). When the content of the crosslinking agent in the pressure-sensitive adhesive composition falls within the above range, the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit more excellent oil resistance.

[0143] In the case of Form 2, the content of the crosslinking agent in the pressure-sensitive adhesive composition is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, still more preferably 0.5 to 7 parts by weight, and particularly preferably 1.5 to 3.5 parts by weight, based on 100 parts by weight of the total amount of the monomer component (m). When the content of the crosslinking agent in the pressure-sensitive adhesive composition falls within the above range, the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit more excellent oil resistance.

[0144] In the case of Form 3, the content of the crosslinking agent in the pressure-sensitive adhesive composition is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, still more preferably 0.5 to 7 parts by weight, and particularly preferably 1.5 to 3.5 parts by weight, based on 100 parts by weight of the total amount of the polymer component (P) and the monomer component (m). When the content of the crosslinking agent in the pressure-sensitive adhesive composition falls within the above range, the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit more excellent oil resistance.

[0145] In the pressure-sensitive adhesive composition, an isocyanate-based crosslinking agent and a non-isocyanate-based crosslinking agent (e.g., an epoxy-based crosslinking agent) can be used in combination. In this case, the ratio of the content of the non-isocyanate-based crosslinking agent to the content of the isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition is preferably 1 / 50 or less, more preferably 1 / 75 or less, still more preferably 1 / 100 or less, and particularly preferably 1 / 150 or less, because the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit more excellent oil resistance. In addition, the ratio of the content of the non-isocyanate-based crosslinking agent to the content of the isocyanate-based crosslinking agent in the pressure-sensitive adhesive composition is preferably 1 / 1,000 or more, more preferably 1 / 500 or more, because the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit more excellent oil resistance.

[0146] <A-2-1-6. Rust inhibitor>

[0147] The pressure-sensitive adhesive composition may include a rust inhibitor. The number of types of the rust inhibitor may be only one, or two or more. When the pressure-sensitive adhesive composition includes a rust inhibitor, the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention may exhibit more excellent oil resistance.

[0148] Any appropriate rust inhibitor may be used as the rust inhibitor within such a range that the effects of the present invention are not impaired. Such a rust inhibitor is, for example, an azole-based rust inhibitor.

[0149] The azole-based rust preventive is preferably a rust preventive containing an azole-based compound as an active ingredient, which is a five-membered aromatic compound containing two or more heteroatoms and in which at least one of the heteroatoms is a nitrogen atom. Examples of such azole-based compounds include azoles such as imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, selenazole, 1,2,3-triazole, 1,2,4-triazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,3,4-thiadiazole, tetrazole, and 1,2,3,4-thiatriazole; derivatives thereof; amine salts thereof; and metal salts thereof.

[0150] Examples of derivatives of azoles are compounds having a structure of a condensed ring including an azole ring and another ring (specifically a benzene ring). Specific examples of derivatives of azoles include benzimidazole, benzotriazole (i.e., 1,2,3-benzotriazole having a condensed structure of an azole ring of 1,2,3-triazole and a benzene ring) and benzothiazole, and derivatives thereof, such as alkylbenzotriazole (e.g., 5-methylbenzotriazole, 5-ethylbenzotriazole, 5-n-propylbenzotriazole, 5-isobutylbenzotriazole or 4-methylbenzotriazole), alkoxybenzotriazole (e.g., 5-methoxybenzotriazole), alkylaminobenzotriazole, alkylaminosulfonylbenzotriazole, and the like. Benzotriazole, mercaptobenzotriazole, hydroxybenzotriazole, nitrobenzotriazole (e.g., 4-nitrobenzotriazole), halogenated benzotriazole (e.g., 5-chlorobenzotriazole), hydroxyalkylbenzotriazole, hydrobenzotriazole, aminobenzotriazole, (substituted aminomethyl)-tolyltriazole, carboxybenzotriazole, N-alkylbenzotriazole, bisbenzotriazole, naphthotriazole, mercaptobenzothiazole and aminobenzothiazole, amine salts thereof, and metal salts thereof. Other examples of derivatives of azoles are derivatives of azoles having a non-fused ring structure, for example, compounds having a structure containing a substituent on a non-fused azole ring, such as 3-amino-1,2,4-triazole or 5-phenyl-1H-tetrazole, etc.

[0151] The azole-based rust inhibitor is particularly preferably a benzotriazole-based rust inhibitor containing a benzotriazole-based compound as an effective ingredient. When a benzotriazole-based rust inhibitor containing a benzotriazole-based compound as an effective ingredient is used as the azole-based rust inhibitor, the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can exhibit more excellent oil resistance.

[0152] Specific examples of the benzotriazole-based compound include 1,2,3-benzotriazole, 5-methylbenzotriazole, 4-methylbenzotriazole, and carboxybenzotriazole.

[0153] The pressure-sensitive adhesive composition may include a rust inhibitor other than an azole rust inhibitor. The number of species of rust inhibitors other than an azole rust inhibitor (non-azole rust inhibitor) may be only one, or more than two. The specific examples of such rust inhibitors other than an azole rust inhibitor include amine compounds, nitrites, ammonium benzoate, ammonium phthalate, ammonium stearate, ammonium palmitate, ammonium oleate, ammonium carbonate, dicyclohexylamine benzoate, urea, hexamethylenetetramine, thiourea, phenylcarbamate, and cyclohexylammonium-N-cyclohexylcarbamate (CHC). The example of an amine compound includes: hydroxyl-containing amine compounds such as 2-amino-2-methyl-1-propanol, monoethanolamine, monoisopropanolamine, diethylethanolamine, ammonia, and ammonia water; cyclic amines such as morpholine; cyclic alkylamine compounds such as cyclohexylamine; and linear alkylamines such as 3-methoxypropylamine. Examples of nitrites include dicyclohexylammonium nitrite (DICHAN), diisopropylammonium nitrite (DIPAN), sodium nitrite, potassium nitrite, and calcium nitrite.

[0154] In the case of Form 1, the content of the rust inhibitor in the pressure-sensitive adhesive composition is preferably 0.01 to 7 parts by weight, more preferably 0.05 to 6 parts by weight, still more preferably 0.1 to 5 parts by weight, particularly preferably 0.3 to 4 parts by weight, most preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the polymer component (P).

[0155] In the case of Form 2, the content of the rust inhibitor in the pressure-sensitive adhesive composition is preferably 0.01 to 7 parts by weight, more preferably 0.05 to 6 parts by weight, still more preferably 0.1 to 5 parts by weight, particularly preferably 0.3 to 4 parts by weight, most preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the total amount of the monomer component (m).

[0156] In the case of Form 3, the content of the rust inhibitor in the pressure-sensitive adhesive composition is preferably 0.01 to 7 parts by weight, more preferably 0.05 to 6 parts by weight, still more preferably 0.1 to 5 parts by weight, particularly preferably 0.3 to 4 parts by weight, most preferably 0.5 to 3 parts by weight, relative to 100 parts by weight of the combined total amount of the polymer component (P) and the monomer component (m).

[0157] 《B. Method for producing double-sided pressure-sensitive adhesive tape》

[0158] In this scope that does not damage the effect of the present invention, the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can be manufactured by any suitable method.The following method is given as the example of this method: each pressure-sensitive adhesive layer is prepared respectively, and is adhered to each other by any suitable method.When taking the situation that the double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention is formed by three layers of pressure-sensitive adhesive layers as an example, the method that relates to the two surfaces of 1 pressure-sensitive adhesive layer and adheres to other 2 each pressure-sensitive adhesive layers is given as its example.For example, a laminating machine can be used for laminating.In addition, after laminating, aging can be carried out at any suitable temperature as required for any suitable time.

[0159] 《C. Typical uses of double-sided pressure-sensitive adhesive tape》

[0160] The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can be used in any suitable application within such a range that the effects of the present invention are not impaired. Typical examples of such applications include mobile device applications. Mobile devices are typically, for example, mobile electronic devices.

[0161] Examples of mobile device uses include, for example, the following uses: for fixing the display portion of a mobile electronic device; for fixing a display portion protection member of a mobile electronic device; for fixing a key module member of a mobile phone (e.g., a smartphone); for fixing a decorative panel of a mobile television; for fixing a battery pack of a mobile personal computer; for waterproofing a digital camera lens; fixing a touch sensor; fixing a vibration generator; fixing a camera; fixing a battery; fixing a narrow member; used as a sealant; and fixing as a gasket agent, such as sealing.

[0162] A preferred example of the use in mobile devices is fixing the member in a mobile device (preferably a mobile electronic device), and a more preferred example thereof is fixing the display portion or the display portion protection member to a housing in the mobile device (preferably a mobile electronic device).

[0163] The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can be particularly preferably used in a mobile electronic device including a display portion such as a liquid crystal display device. The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention is suitable for use, for example, in which a display portion such as a liquid crystal display device or a display portion protection member and a housing are joined to each other in such a mobile electronic device.

[0164] The display unit protection member is typically a member having an area showing light transmittance in its thickness direction (hereinafter sometimes referred to as a "light-transmitting member"), and is sometimes referred to as a "lens". Here, the term "lens" used in this article is a concept that includes both a lens that shows a light refraction effect and a lens that does not show any light refraction effect. In other words, the term "lens" used in this article includes a light-transmitting member without any refractive effect, such as a protective panel that is only configured to protect the display unit of a mobile electronic device. Such a protective panel can also be understood as a display unit protection member or a display unit covering member having light transmittance. When the material of such a protective panel is glass, the protective panel can also be referred to as "cover glass". However, the material of such a protective panel or lens is not limited to glass, and only needs to be a material that can show light transmittance.

[0165] In addition, the term "mobile electronic device" used in this article may include any suitable device, as long as the device is an electronic device that can be carried and used. Here, for the level required by the term "carry", the state in which the device can only be carried is insufficient, and the term means that the device has portability at the following level: an individual (a standard adult) can carry the device in a relatively easy manner. Examples of "mobile electronic devices" used in this article include mobile phones, smart phones, tablet PCs, and laptop PCs. Such mobile electronic devices can be so-called wearable (for example, wristband types such as wristwatches, or head-mounted types such as glasses) terminals. Specific examples of such mobile electronic devices include: phones, watches, cameras, glasses, personal computers, and other information terminals; health care tools such as sphygmomanometers, pulse meters, and pedometers; and music players, video players, and products with one or more functions such as recording and video recording.

[0166] Example

[0167] Now, the present invention is specifically described by examples. However, the present invention is by no means limited to the examples. The test and evaluation methods in the examples, etc. are as follows. Unless otherwise specified, the term "part" in the following description means "part by weight", and unless otherwise specified, the term "%" in the following description means "wt%".

[0168] <Weight Average Molecular Weight>

[0169] The weight average molecular weight is determined from a value obtained by gel permeation chromatography (GPC) in terms of standard polystyrene. An apparatus available under the model "HLC-8320GPC" (chromatographic column: TSKgel GMH-H(S), manufactured by Tosoh Corporation) is used as a GPC apparatus.

[0170] <Impact Resistance>

[0171] The double-sided pressure-sensitive adhesive tape sandwiched between the separators is punched into a frame shape with a width of 2mm and an outer shape of 24.5 mm square to provide an evaluation sample. The evaluation sample is set between a square stainless steel plate with a hole in the central part of a thickness of 2mm and an outer shape of 50mm×50mm and a square stainless steel plate (outer shape 25mm square, thickness 3mm), and is pressed (crimped) on the plate (62N×10 seconds) in such a way that the force is uniformly applied to the sample in the direction of gravity. Afterwards, the resultant is left to stand at 50°C for 2 hours and taken out. Afterwards, the resultant is restored to an environment of 23°C to provide a test piece. A cylindrical measuring platform with a length of 50mm, an outer diameter of 49mm, and an inner diameter of 43mm is set on the base of a Du Pont type impact tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.), and the test piece is mounted thereon in such a way that the square stainless steel plate is located on the lower side. A stainless steel impact shaft with a tip radius of 3.1 mm was mounted on the test piece, and the weight of the drop weight and its drop height were changed as follows to increase the energy until peeling of the tape occurred: when the weight was 100 g, the height was changed from 50 mm to 500 mm in increments of 50 mm; when the weight was 150 g, the height was changed from 350 mm to 500 mm in increments of 50 mm; when the weight was 200 g, the height was changed from 400 mm to 500 mm in increments of 50 mm; and when the weight was 300 g, the height was changed from 350 mm to 500 mm in increments of 50 mm. At this time, for the energy that had been evaluated, no test was performed, and the load and height were set in such a way that the amounts of energy did not overlap each other. Afterwards, the energy immediately before peeling was calculated from the expression "load × height" and used as the result.

[0172] [Manufacturing Example 1]: Manufacture of pressure-sensitive adhesive layer (1)

[0173] 95 parts of butyl acrylate and 5 parts of acrylic acid as monomer components and 233 parts of ethyl acetate as a polymerization solvent were charged into a reaction vessel including a stirrer, a thermometer, a nitrogen introduction tube, a reflux condenser, and a dropping funnel, and stirred for 2 hours while introducing nitrogen into the vessel. After oxygen in the polymerization system had been removed as described above, 0.2 parts of 2,2′-azobisisobutyronitrile was added to the mixture as a polymerization initiator, and the whole was subjected to solution polymerization at 60° C. for 8 hours, thereby providing a solution of an acrylic polymer. The weight average molecular weight of the acrylic polymer was 700,000.

[0174] With respect to 100 parts of the acrylic polymer in the obtained acrylic polymer solution, 20 parts of a terpene-phenol resin (trade name: "YS POLYSTER T-115", softening point: about 115° C., hydroxyl value: 30 mgKOH / g to 60 mgKOH / g, manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier resin, 3 parts of an isocyanate crosslinking agent (trade name: "CORONATE L", 75% ethyl acetate solution of trimethylolpropane / toluene diisocyanate trimer adduct, manufactured by Tosoh Corporation) and 0.02 parts of an epoxy crosslinking agent (trade name: "TETRAD-C", 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, manufactured by Mitsubishi Gas Chemical Company, Inc.) as a crosslinking agent, and 6 parts of a product available under the trade name "ATDN 101BLACK" (manufactured by Dainichiseika Color & Chemicals) as a black pigment were added. Mfg. Co., Ltd.), and 5 parts of an acrylonitrile-based hollow filler (trade name "MATSUMOTO MICROSPHERE MFL-81GCA", manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., specific gravity = 0.23, heat resistance = 130°C, average particle size = 20 μm) as an organic-based hollow filler were added to the solution, and the contents were stirred and mixed to prepare a pressure-sensitive adhesive composition (1).

[0175] The pressure-sensitive adhesive composition (1) was applied onto the release surface of a 38 μm thick polyester release liner (trade name: "DIAFOILMRF", manufactured by Mitsubishi Polyester Film, Inc.) and dried at 100° C. for 2 minutes to form a 100 μm thick pressure-sensitive adhesive layer (1).

[0176] [Manufacturing Example 2]: Manufacture of pressure-sensitive adhesive layer (2)

[0177] A pressure-sensitive adhesive layer (2) having a thickness of 100 μm was formed in the same manner as in Production Example 1 except that the amount of the organic hollow filler was changed to 2 parts.

[0178] [Manufacturing Example 3]: Manufacture of pressure-sensitive adhesive layer (3)

[0179] A pressure-sensitive adhesive layer (3) having a thickness of 100 μm was formed in the same manner as in Production Example 1 except that the amount of the organic hollow filler was changed to 0.5 parts.

[0180] [Manufacturing Example 4]: Manufacture of pressure-sensitive adhesive layer (4)

[0181] A pressure-sensitive adhesive layer (4) having a thickness of 100 μm was formed in the same manner as in Production Example 1 except that the amount of the organic hollow filler was changed to 10 parts.

[0182] [Manufacturing Example 5]: Manufacture of pressure-sensitive adhesive layer (5)

[0183] A pressure-sensitive adhesive layer (5) having a thickness of 100 μm was formed in the same manner as in Production Example 1, except that the organic hollow filler was changed to 1 part of an acrylonitrile hollow filler (trade name: "MATSUMOTOMICROSPHERE MFL-HD30CA", manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., specific gravity = 0.14, heat resistance = 140°C, average particle size = 30 μm).

[0184] [Manufacturing Example 6]: Manufacture of pressure-sensitive adhesive layer (6)

[0185] A pressure-sensitive adhesive layer (6) having a thickness of 100 μm was formed in the same manner as in Production Example 5 except that the amount of the organic hollow filler was changed to 5 parts.

[0186] [Manufacturing Example 7]: Manufacture of pressure-sensitive adhesive layer (7)

[0187] A pressure-sensitive adhesive layer (7) having a thickness of 100 μm was formed in the same manner as in Production Example 5 except that the amount of the organic hollow filler was changed to 10 parts.

[0188] [Manufacturing Example 8]: Manufacture of pressure-sensitive adhesive layer (8)

[0189] A pressure-sensitive adhesive layer (8) having a thickness of 100 μm was formed in the same manner as in Production Example 1, except that the organic hollow filler was changed to 1 part of an acrylonitrile hollow filler (trade name: "MATSUMOTOMICROSPHERE MFL-100MCA", manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., specific gravity = 0.12, heat resistance = 155°C, average particle size = 60 μm).

[0190] [Manufacturing Example 9]: Manufacture of pressure-sensitive adhesive layer (9)

[0191] A pressure-sensitive adhesive layer (9) having a thickness of 100 μm was formed in the same manner as in Production Example 8 except that the amount of the organic hollow filler was changed to 3 parts.

[0192] [Manufacturing Example 10]: Manufacture of pressure-sensitive adhesive layer (10)

[0193] A pressure-sensitive adhesive layer (10) having a thickness of 100 μm was formed in the same manner as in Production Example 8 except that the amount of the organic hollow filler was changed to 5 parts.

[0194] [Manufacturing Example 11]: Manufacture of pressure-sensitive adhesive layer (11)

[0195] A pressure-sensitive adhesive layer (11) having a thickness of 100 μm was formed in the same manner as in Production Example 1, except that the organic hollow filler was changed to 0.1 parts of an acrylonitrile hollow filler (trade name: "MATSUMOTOMICROSPHERE FN-80SDE", manufactured by Matsumoto Yushi-Seiyaku Co., Ltd., specific gravity = 0.025, heat resistance = 140°C, average particle size = 30 μm).

[0196] [Manufacturing Example 12]: Manufacture of pressure-sensitive adhesive layer (12)

[0197] A pressure-sensitive adhesive layer (12) having a thickness of 100 μm was formed in the same manner as in Production Example 11 except that the amount of the organic hollow filler was changed to 2 parts.

[0198] [Manufacturing Example 13]: Manufacture of pressure-sensitive adhesive layer (13)

[0199] A pressure-sensitive adhesive layer (13) having a thickness of 200 μm was formed in the same manner as in Production Example 1, except that: the hollow filler was not used; and the thickness of the pressure-sensitive adhesive composition after drying was set to 200 μm.

[0200] [Manufacturing Example 14]: Manufacture of pressure-sensitive adhesive layer (14)

[0201] A pressure-sensitive adhesive layer (14) having a thickness of 85 μm was formed in the same manner as in Production Example 1, except that: the hollow filler was not used; and the thickness of the pressure-sensitive adhesive composition after drying was set to 85 μm.

[0202] [Example 1]

[0203] The two surfaces of the pressure-sensitive adhesive layer on which the release liner was not provided of the pressure-sensitive adhesive layer (1) obtained in Production Example 1 were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (1) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (1) / pressure-sensitive adhesive layer (1)) was obtained.

[0204] The evaluation results of the belts are shown in Table 1.

[0205] in addition, Figure 2 A photograph of a cross section of the obtained double-sided pressure-sensitive adhesive tape (1) taken with a scanning electron microscope (S-3400N manufactured by Hitachi High-Technologies Corporation) is shown in FIG.

[0206] [Example 2]

[0207] The two surfaces of the pressure-sensitive adhesive layer on which the release liner was not provided of the pressure-sensitive adhesive layer (2) obtained in Production Example 2 were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (2) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (2) / pressure-sensitive adhesive layer (2)) was obtained.

[0208] The evaluation results of the belts are shown in Table 1.

[0209] [Example 3]

[0210] The surfaces of the pressure-sensitive adhesive layer (3) obtained in Production Example 3 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (3) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (3) / pressure-sensitive adhesive layer (3)) was obtained.

[0211] The evaluation results of the belts are shown in Table 1.

[0212] [Example 4]

[0213] The surfaces of the pressure-sensitive adhesive layer (4) obtained in Production Example 4 on which no release liner was provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (4) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (4) / pressure-sensitive adhesive layer (4)) was obtained.

[0214] The evaluation results of the belts are shown in Table 1.

[0215] [Example 5]

[0216] The surfaces of the pressure-sensitive adhesive layer (5) obtained in Production Example 5 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (5) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (5) / pressure-sensitive adhesive layer (5)) was obtained.

[0217] The evaluation results of the belts are shown in Table 1.

[0218] [Example 6]

[0219] The surfaces of the pressure-sensitive adhesive layer (6) obtained in Production Example 6 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (6) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (6) / pressure-sensitive adhesive layer (6)) was obtained.

[0220] The evaluation results of the belts are shown in Table 1.

[0221] [Example 7]

[0222] The surfaces of the pressure-sensitive adhesive layer (7) obtained in Production Example 7 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (7) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (7) / pressure-sensitive adhesive layer (7)) was obtained.

[0223] The evaluation results of the belts are shown in Table 1.

[0224] [Example 8]

[0225] The surfaces of the pressure-sensitive adhesive layer (8) obtained in Production Example 8 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (8) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (8) / pressure-sensitive adhesive layer (8)) was obtained.

[0226] The evaluation results of the belts are shown in Table 1.

[0227] [Example 9]

[0228] The surfaces of the pressure-sensitive adhesive layer (9) obtained in Production Example 9 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (9) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (9) / pressure-sensitive adhesive layer (9)) was obtained.

[0229] The evaluation results of the belts are shown in Table 1.

[0230] [Example 10]

[0231] The surfaces of the pressure-sensitive adhesive layer (10) obtained in Production Example 10 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (10) having a total thickness of 200 μm (construction: pressure-sensitive adhesive layer (10) / pressure-sensitive adhesive layer (10)) was obtained.

[0232] The evaluation results of the belts are shown in Table 1.

[0233] [Example 11]

[0234] The surfaces of the pressure-sensitive adhesive layer (11) obtained in Production Example 11 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (11) (construction: pressure-sensitive adhesive layer (11) / pressure-sensitive adhesive layer (11)) having a total thickness of 200 μm was obtained.

[0235] The evaluation results of the belts are shown in Table 1.

[0236] [Example 12]

[0237] The surfaces of the pressure-sensitive adhesive layer (12) obtained in Production Example 12 on which the release liner was not provided were bonded to each other. The resulting structure was passed through a laminator (0.3 MPa, speed: 0.5 m / min) once at room temperature and then aged in an oven at 50° C. for 1 day. Thereafter, the release liner was peeled off. Thus, as shown in Table 1, a double-sided pressure-sensitive adhesive tape (12) (construction: pressure-sensitive adhesive layer (12) / pressure-sensitive adhesive layer (12)) having a total thickness of 200 μm was obtained.

[0238] The evaluation results of the belts are shown in Table 1.

[0239] [Comparative Example 1]

[0240] The release liner of the pressure-sensitive adhesive layer (16) obtained in Production Example 16 was peeled off. Thus, as shown in Table 1, a single-layer double-sided pressure-sensitive adhesive tape (C1) having a total thickness of 200 μm was obtained (configuration: pressure-sensitive adhesive layer (16)).

[0241] The evaluation results of the belts are shown in Table 1.

[0242] [Comparative Example 2]

[0243] The release liner of the pressure-sensitive adhesive layer (17) obtained in Production Example 17 was peeled off. Thus, as shown in Table 1, a single-layer double-sided pressure-sensitive adhesive tape (C2) having a total thickness of 85 μm was obtained (configuration: pressure-sensitive adhesive layer (17)).

[0244] The evaluation results of the belts are shown in Table 1.

[0245]

[0246] According to at least one embodiment of the present invention, a double-sided pressure-sensitive adhesive tape that can exhibit excellent impact resistance can be provided.

[0247] The double-sided pressure-sensitive adhesive tape according to at least one embodiment of the present invention can be suitably used in the interior of mobile devices and the like.

Claims

1. A double-sided pressure-sensitive adhesive tape for fixing a member included in a mobile device, The double-sided pressure-sensitive adhesive tape comprises a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition, and wherein the pressure-sensitive adhesive composition comprises an organic hollow filler and an acrylic polymer as a base polymer, The acrylic polymer is formed by polymerization of a monomer component (m), The monomer component (m) comprises 90 wt% to 100 wt% of n-butyl (meth)acrylate. The specific gravity of the organic hollow filler is 0.05 to 1.

00. The adhesive layer is an adhesive layer laminated body in which n or more adhesive layers are laminated, where n is an integer of 2 or more, and the adhesive layer laminated body has (n-1) interfaces. 2 . The double-sided pressure-sensitive adhesive tape according to claim 1 , wherein the average particle size of the organic hollow filler is 5 μm to 70 μm. 3 . The double-sided pressure-sensitive adhesive tape according to claim 2 , wherein the organic hollow filler is an acrylonitrile hollow filler. 4 . The double-sided pressure-sensitive adhesive tape according to claim 1 , wherein the double-sided pressure-sensitive adhesive tape has a thickness of 100 μm or more. 5 . The double-sided pressure-sensitive adhesive tape according to claim 1 , wherein the double-sided pressure-sensitive adhesive tape is used to fix one of a display portion and a display portion protection member to a housing in the mobile device.

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