WO2024009530A1 - 粘着シート - Google Patents

粘着シート Download PDF

Info

Publication number
WO2024009530A1
WO2024009530A1 PCT/JP2022/045738 JP2022045738W WO2024009530A1 WO 2024009530 A1 WO2024009530 A1 WO 2024009530A1 JP 2022045738 W JP2022045738 W JP 2022045738W WO 2024009530 A1 WO2024009530 A1 WO 2024009530A1
Authority
WO
WIPO (PCT)
Prior art keywords
weight
less
adhesive sheet
adhesive layer
adhesive
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2022/045738
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
徹 田上
茂樹 渡辺
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nitto Denko Corp
Original Assignee
Nitto Denko Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=88917978&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO2024009530(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Nitto Denko Corp filed Critical Nitto Denko Corp
Priority to KR1020257001898A priority Critical patent/KR102807071B1/ko
Priority to CN202280097496.1A priority patent/CN119421937B/zh
Publication of WO2024009530A1 publication Critical patent/WO2024009530A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]
    • C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • C09J7/385—Acrylic polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L57/00—Compositions of unspecified polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C08L57/02—Copolymers of mineral oil hydrocarbons
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L93/00—Compositions of natural resins; Compositions of derivatives thereof
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/08—Macromolecular additives
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09J133/08—Homopolymers or copolymers of acrylic acid esters
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J161/00—Adhesives based on condensation polymers of aldehydes or ketones; Adhesives based on derivatives of such polymers
    • C09J161/04—Condensation polymers of aldehydes or ketones with phenols only
    • C09J161/06—Condensation polymers of aldehydes or ketones with phenols only of aldehydes with phenols
    • C09J161/14—Modified phenol-aldehyde condensates
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J193/00—Adhesives based on natural resins; Adhesives based on derivatives thereof
    • C09J193/04—Rosin
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]

Definitions

  • the present invention relates to an adhesive sheet.
  • This application claims priority based on Japanese Patent Application No. 2022-108023 filed on July 4, 2022, and the entire contents of that application are incorporated herein by reference.
  • adhesives also referred to as pressure-sensitive adhesives, hereinafter the same
  • adhesives exhibit a soft solid (viscoelastic) state in the temperature range around room temperature, and have the property of adhering to adherends under pressure.
  • adhesives are used in various industrial fields, from mobile electronic devices such as smartphones and home appliances to automobiles and OA equipment, typically in the form of adhesive sheets containing an adhesive layer, for bonding parts and other applications. It is widely used for purposes such as surface protection.
  • Technical documents regarding pressure-sensitive adhesive sheets include Patent Documents 1 and 2.
  • Patent Documents 1 and 2 describe adhesives containing acrylic polymers polymerized using heptyl acrylate as a monomer component.
  • Adhesive sheets are required to have various performances depending on the location of application and how they are used. For example, when fixing components inside a portable electronic device using an adhesive sheet, the adhesion area is usually small due to size, weight, and other limitations. Adhesive sheets used for this purpose need to have adhesive strength that can achieve good fixation even on a small area, and the required performance has become higher due to demands for lighter weight and smaller size. ing. In particular, mobile electronic devices equipped with touch-panel displays, such as smartphones, are becoming smaller and thinner, while their screens are becoming larger from the viewpoint of display visibility and operability. For these reasons, adhesives used are required to have adhesive fixing performance under harsher conditions.
  • the adhesion area is of course limited, and for example, an elastic member such as a flexible printed circuit board (FPC) can be bent and accommodated in the limited internal space of a portable electronic device.
  • FPC flexible printed circuit board
  • Measures are being taken to precisely position and stably fix it using an adhesive sheet.
  • a continuous peeling load is applied in the thickness direction (also called the Z-axis direction) of the adhesive sheet, so it is necessary to have repulsion resistance that can sustainably resist the elastic repulsion of the above-mentioned members. (specifically, durability against a continuous peeling load applied in the thickness direction (Z-axis direction) of the pressure-sensitive adhesive sheet).
  • Adhesive sheets that are attached to complex shapes are required to have the ability to closely follow and adhere to the shape.
  • the adhesive sheet that fixes a member such as a cover glass that has a complicated surface shape tends to be subjected to a larger sustained peeling load than before.
  • Adhesive sheets used for such applications are required to have higher levels of repulsion resistance against sustained peeling loads.
  • the temperature and humidity inside the above-mentioned portable electronic devices are affected not only by the heat inside the electronic device but also by the external environment, and can reach a high temperature of over 50 degrees Celsius. It is also possible. Even under such an environment, the adhesive used for this purpose may be required to exhibit stable repulsion resistance in the Z-axis direction.
  • Impact resistance can be improved by lowering the elastic modulus of the adhesive, but if the elastic modulus of the adhesive is designed to be low, for example by lowering the degree of crosslinking, the cohesion required for repulsion resistance can be improved. The force also decreases, making it difficult to obtain good repulsion resistance. In this way, repulsion resistance and impact resistance are contradictory properties, and it is difficult to achieve both.
  • an object of the present invention is to provide a pressure-sensitive adhesive sheet that can achieve both high levels of repulsion resistance and impact resistance.
  • an adhesive sheet has an adhesive layer containing an acrylic polymer.
  • the acrylic polymer is a polymer of monomer components containing heptyl acrylate.
  • the adhesive layer has a storage modulus G' of 20,000 Pa or more at 65°C, and a tan ⁇ of 0.3 or more at -20°C.
  • tan ⁇ refers to the ratio (G''/G') of the loss elastic modulus G'' to the storage elastic modulus G' of the adhesive layer.
  • the adhesive layer has a 65° C. storage modulus of 20,000 Pa or more, and therefore can exhibit good repulsion resistance. Furthermore, since the -20°C tan ⁇ of the adhesive layer is 0.3 or more, excellent impact resistance is likely to be obtained. Balancing the storage modulus G' at 65° C. and tan ⁇ at ⁇ 20° C. can be suitably achieved by using an acrylic polymer containing heptyl acrylate as a monomer component. According to the pressure-sensitive adhesive sheet having the above structure, both repulsion resistance and impact resistance can be achieved at a high level.
  • the weight average molecular weight (Mw) of the acrylic polymer is 700,000 or more.
  • Mw weight average molecular weight
  • the glass transition temperature (Tg) of the adhesive layer is within the range of -15°C to 15°C.
  • the glass transition temperature of the adhesive layer refers to the glass transition temperature determined from the peak temperature of tan ⁇ in dynamic viscoelasticity measurement. In an adhesive layer having a Tg within the range of -15°C to 15°C, both repulsion resistance and impact resistance are likely to be achieved.
  • the adhesive layer further includes a tackifying resin.
  • the technology disclosed herein is preferably implemented with a configuration in which the adhesive layer contains a tackifier resin.
  • the tackifying resin at least one selected from rosin-based tackifying resins and terpene-based tackifying resins is preferably used.
  • the content of the tackifier resin in the adhesive layer is 70 parts by weight or less based on 100 parts by weight of the acrylic polymer.
  • the effects of the technology disclosed herein can be preferably achieved by appropriately adjusting the content of the tackifier resin in the adhesive layer within the above range.
  • the adhesive layer further includes an acrylic oligomer.
  • the technique disclosed herein is preferably implemented in an embodiment in which the adhesive layer contains an acrylic oligomer. Among these, it is more preferable to use a tackifying resin and an acrylic oligomer together.
  • the adhesive composition for forming the adhesive layer includes at least one selected from an isocyanate crosslinking agent and an epoxy crosslinking agent.
  • a crosslinking agent selected from isocyanate crosslinking agents and epoxy crosslinking agents By using a crosslinking agent selected from isocyanate crosslinking agents and epoxy crosslinking agents, the cohesive force of the adhesive can be appropriately increased, and while having impact resistance, it is possible to preferably improve repulsion resistance. can.
  • the adhesive sheet according to some preferred embodiments has a 180 degree peel strength against a stainless steel plate (adhesive strength against SUS) of 20 N/25 mm or more.
  • the pressure-sensitive adhesive sheet having the above adhesive strength against SUS can exhibit excellent adhesive strength.
  • the pressure-sensitive adhesive sheet disclosed herein is capable of achieving both repulsion resistance and impact resistance, and is therefore preferably used for bonding components of portable electronic devices that may require high repulsion resistance and impact resistance.
  • this specification provides a portable electronic device using any of the adhesive sheets disclosed herein, in other words, a portable electronic device including the adhesive sheet.
  • FIG. 1 is a cross-sectional view schematically showing the configuration of a pressure-sensitive adhesive sheet according to an embodiment.
  • FIG. 3 is a cross-sectional view schematically showing the configuration of a pressure-sensitive adhesive sheet according to another embodiment.
  • FIG. 3 is a cross-sectional view schematically showing the configuration of a pressure-sensitive adhesive sheet according to another embodiment.
  • FIG. 1 is a front view schematically showing an example of a portable electronic device including an adhesive sheet. It is a schematic diagram explaining the method of a Z-axis direction repulsion resistance test.
  • the term "adhesive” as used herein refers to a material that exhibits a soft solid (viscoelastic) state in the temperature range around room temperature and has the property of easily adhering to an adherend under pressure. .
  • the adhesive referred to here generally has a complex tensile modulus E * (1Hz) as defined in "C. A. Dahlquist, “Adhesion: Fundamentals and Practice", McLaren & Sons, (1966) P. 143". ⁇ 10 7 dyne/cm 2 (typically, a material having the above properties at 25° C.).
  • biomass-derived carbon means carbon derived from biomass materials, that is, materials derived from renewable organic resources (renewable carbon).
  • biomass materials are typically materials derived from biological resources (typically plants that perform photosynthesis) that can be reproduced sustainably in the presence of sunlight, water, and carbon dioxide. means. Therefore, materials derived from fossil resources that are depleted through use after mining (fossil resource-based materials) are excluded from the concept of biomass materials here.
  • the biomass carbon ratio of the adhesive layer and the adhesive sheet that is, the proportion of biomass-derived carbon in the total carbon contained in the adhesive layer and the adhesive sheet, is the carbon isotope content with a mass number of 14 measured in accordance with ASTM D6866. It can be estimated from the amount.
  • the adhesive sheet disclosed herein includes an adhesive layer.
  • the above-mentioned pressure-sensitive adhesive sheet is, for example, a base material-less double-sided pressure-sensitive adhesive sheet comprising a first pressure-sensitive adhesive surface formed by one surface of the pressure-sensitive adhesive layer, and a second pressure-sensitive adhesive surface formed by the other surface of the pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive sheet disclosed herein may be in the form of a pressure-sensitive adhesive sheet with a base material, in which the pressure-sensitive adhesive layer is laminated on one or both sides of a support base material.
  • the supporting base material may be simply referred to as "base material”.
  • adhesive sheet here may include what is called an adhesive tape, an adhesive label, an adhesive film, and the like.
  • the pressure-sensitive adhesive sheet disclosed herein may be in the form of a roll or a sheet. Alternatively, the adhesive sheet may be further processed into various shapes.
  • FIG. 1 The structure of a pressure-sensitive adhesive sheet according to one embodiment is schematically shown in FIG.
  • This adhesive sheet 1 is configured as a double-sided adhesive sheet without a base material, which includes an adhesive layer 21.
  • the adhesive sheet 1 has a first adhesive surface 21A constituted by one surface (first surface) of the adhesive layer 21, and a second adhesive surface constituted by the other surface (second surface) of the adhesive layer 21. 21B are attached to different parts of the adherend.
  • the locations on which the adhesive surfaces 21A and 21B are attached may be on different members, or may be on different locations within a single member. As shown in FIG.
  • the adhesive sheet 1 before use (that is, before being attached to an adherend) has a first adhesive surface 21A and a second adhesive surface 21B that are peeled off at least on the side facing the adhesive layer 21. It may be a component of the adhesive sheet 100 with a release liner that is protected by the release liners 31 and 32 serving as surfaces.
  • the release liners 31 and 32 it is preferable to use, for example, a sheet-like base material (liner base material) that has a release layer formed of a release treatment agent on one side so that one side becomes a release surface. obtain.
  • the release liner 32 may be omitted and a release liner 31 having release surfaces on both sides may be used, and this and the adhesive sheet 1 may be overlapped and spirally wound so that the second adhesive surface 21B is on the release liner 31.
  • the pressure-sensitive adhesive sheet with a release liner may be configured in a form (roll form) in which the pressure-sensitive adhesive sheet is in a protected form (in the form of a roll) in contact with the back surface of the adhesive sheet.
  • FIG. 2 The structure of a pressure-sensitive adhesive sheet according to another embodiment is schematically shown in FIG. 2.
  • This adhesive sheet 2 is a base material comprising a sheet-shaped support base material (for example, a resin film) 10 having a first surface 10A and a second surface 10B, and an adhesive layer 21 provided on the first surface 10A side. It is constructed as a single-sided adhesive sheet.
  • the adhesive layer 21 is fixedly provided on the first surface 10A side of the support base material 10, that is, without the intention of separating the adhesive layer 21 from the support base material 10. As shown in FIG.
  • the pressure-sensitive adhesive sheet 2 before use has a surface (adhesive surface) 21A of the pressure-sensitive adhesive layer 21 protected by a release liner 31 having at least the side facing the pressure-sensitive adhesive layer 21 as a release surface. It may be a component of the pressure-sensitive adhesive sheet 200 with a release liner. Alternatively, the release liner 31 may be omitted, the second surface 10B may be the release surface of the support base material 10, and the adhesive sheet 2 may be wound so that the adhesive surface 21A is the second surface (back surface) of the support base material 10. ) 10B may be in a protected form (roll form).
  • FIG. 3 schematically shows the structure of a pressure-sensitive adhesive sheet according to yet another embodiment.
  • This adhesive sheet 3 includes a sheet-shaped support base material (for example, a resin film) 10 having a first surface 10A and a second surface 10B, and a first adhesive layer 21 fixedly provided on the first surface 10A side. and a second adhesive layer 22 fixedly provided on the second surface 10B side.
  • 32 may be a component of the adhesive sheet 300 with a release liner.
  • the release liner 32 may be omitted and a release liner 31 having release surfaces on both sides may be used, and this and the adhesive sheet 3 may be overlapped and spirally wound so that the second adhesive surface 22A is on the release liner 31.
  • the pressure-sensitive adhesive sheet with a release liner may be configured in a form (roll form) in which the pressure-sensitive adhesive sheet is in a protected form (in the form of a roll) in contact with the back surface of the adhesive sheet.
  • the first adhesive layer and the second adhesive layer may be the adhesive layer described below.
  • the other adhesive layer (for example, the second adhesive layer) may be the adhesive layer disclosed herein, and the adhesive layer disclosed herein (specifically, the one adhesive layer described above) may be the adhesive layer disclosed herein.
  • the adhesive layer may have a composition different from that of the adhesive layer (for example, the first adhesive layer).
  • the other pressure-sensitive adhesive layer may be formed from a known or commonly used pressure-sensitive adhesive, for example.
  • the present invention is disclosed herein in the form of a double-sided pressure-sensitive adhesive sheet without a base material consisting of an adhesive layer, or in the form of a pressure-sensitive adhesive sheet with a base material comprising a base material other than a foam base material (non-foam base material).
  • the technique can be implemented.
  • the form of a base material-less double-sided pressure-sensitive adhesive sheet is preferred.
  • the base material-less double-sided pressure-sensitive adhesive sheet does not have a base material, it can be made thinner, and can contribute to miniaturization and space saving of products to which the double-sided pressure-sensitive adhesive sheet is applied. Moreover, according to the base material-less adhesive sheet, the effects of the adhesive layer such as repulsion resistance and impact resistance against continuous loads in the Z-axis direction can be maximized.
  • the adhesive layer disclosed herein in an embodiment including a first adhesive layer and a second adhesive layer, at least one of the first adhesive layer and the second adhesive layer.
  • the same applies hereinafter unless otherwise specified has a storage modulus G' of 20,000 Pa or more at 65°C. According to the pressure-sensitive adhesive having a storage modulus of 65° C., good repulsion resistance (especially repulsion resistance against a sustained load in the Z-axis direction in a harsh environment such as a high temperature condition) is easily obtained.
  • the 65°C storage modulus is 21,000 Pa or more, may be 22,000 Pa or more, suitably 23,000 Pa or more, and more Preferably it is 24,000 Pa or more, more preferably 25,000 Pa or more, particularly preferably 26,000 Pa or more, it may be 27,000 Pa or more, it may be 28,000 Pa or more, it may be 29,000 Pa or more, and it may be 30,000 Pa or more. ,000 Pa or more, 31,000 Pa or more, 32,000 Pa or more, or 33,000 Pa or more.
  • the upper limit of the 65° C. storage modulus can be set within an appropriate range that allows both repulsion resistance and impact resistance to be achieved.
  • the 65°C storage modulus is suitably about 60,000 Pa or less, preferably 50,000 Pa or less, more preferably 40,000 Pa or less, and even more preferably 35,000 Pa or less.
  • the pressure may be 32,000 Pa or less, 30,000 Pa or less, 28,000 Pa or less, or 26,000 Pa or less.
  • the adhesive layer disclosed herein is characterized by having a storage modulus of elasticity at 65°C of 20,000 Pa or more and a tan ⁇ at -20°C of 0.3 or more.
  • the above tan ⁇ (loss tangent) refers to the ratio (G''/G') of the loss elastic modulus G'' to the storage elastic modulus G' of the adhesive layer.
  • -20°C corresponds to the impact velocity range during a fall according to the temperature-velocity conversion rule.
  • An adhesive having a tan ⁇ of 0.3 or more at ⁇ 20° C. can easily provide excellent impact resistance.
  • the -20°C tan ⁇ is 0.35 or more, may be 0.40 or more, or may be 0.45 or more.
  • the -20°C tan ⁇ is 0.50 or more, more preferably 0.55 or more, and still more preferably 0.60 or more from the viewpoint of impact resistance.
  • the upper limit of the above-mentioned -20°C tan ⁇ can be set within an appropriate range that can achieve both repulsion resistance and impact resistance.
  • the above-mentioned -20°C tan ⁇ may be, for example, approximately 2 or less, 1.8 or less, 1.6 or less, or 1.4 or less.
  • the -20°C tan ⁇ is suitably 1.2 or less, and from the viewpoint of repulsion resistance, preferably 1.0 or less, more preferably 0.80 or less, and even more preferably 0.70. or less, and may be 0.60 or less, or may be 0.55 or less.
  • the glass transition temperature (Tg) of the adhesive layer is within the range of -15°C to 15°C.
  • the glass transition temperature of the adhesive layer refers to the glass transition temperature determined from the peak temperature of tan ⁇ in dynamic viscoelasticity measurement.
  • the Tg of the adhesive layer is more preferably -12°C or higher, even more preferably -10°C or higher, particularly preferably -7°C or higher, may be -5°C or higher, and -3°C or higher.
  • the temperature may be higher than or equal to -1°C, higher than 0°C (for example, higher than 0°C), or higher than 1°C.
  • the Tg of the adhesive layer is preferably 12°C or less, more preferably 10°C or less, even more preferably 7°C or less, particularly preferably 5°C or less, and particularly preferably 3°C or less.
  • the temperature may be 1°C or lower, 0°C or lower (for example, lower than 0°C), -1°C or lower, or -3°C or lower.
  • the 65°C storage modulus, -20°C tan ⁇ , and Tg of the adhesive layer can be determined by dynamic viscoelasticity measurement.
  • an adhesive layer with a thickness of about 2 mm is produced by stacking a plurality of adhesive layers (adhesive sheets in the case of a base material-less adhesive sheet) to be measured. A sample of this adhesive layer was punched into a disk shape with a diameter of 7.9 mm, which was sandwiched and fixed between parallel plates. Dynamic viscoelasticity was measured under the following conditions to determine the storage modulus at 65°C, tan ⁇ at -20°C, and Tg.
  • ⁇ Measurement mode Shear mode ⁇ Temperature range: -70°C ⁇ 150°C ⁇ Heating rate: 5°C/min ⁇ Measurement frequency: 1Hz
  • the above-mentioned method is also used in the Examples described below.
  • the adhesive layer to be measured may be formed by applying a corresponding adhesive composition in a layered manner and drying or curing it.
  • the adhesive layer constituting the adhesive sheet disclosed herein contains an acrylic polymer.
  • the pressure-sensitive adhesive layer is typically a pressure-sensitive adhesive layer containing an acrylic polymer as a base polymer.
  • Such an adhesive layer is also referred to as an acrylic adhesive layer.
  • the base polymer refers to the main component of a rubbery polymer (a polymer that exhibits rubber elasticity in a temperature range around room temperature) contained in the adhesive layer.
  • the term "main component” refers to a component contained in an amount exceeding 50% by weight, unless otherwise specified.
  • the following description regarding the adhesive and the components that can be included in the adhesive layer is also applicable to the adhesive composition used to form the adhesive (layer) unless otherwise specified.
  • the term "acrylic polymer” refers to a polymer containing monomer units derived from a monomer having at least one (meth)acryloyl group in one molecule, as monomer units constituting the polymer. .
  • a monomer having at least one (meth)acryloyl group in one molecule will also be referred to as an "acrylic monomer.”
  • an acrylic polymer in this specification is defined as a polymer containing monomer units derived from acrylic monomers.
  • (meth)acryloyl” refers comprehensively to acryloyl and methacryloyl.
  • (meth)acrylate” comprehensively refers to acrylate and methacrylate
  • (meth)acrylic” comprehensively refers to acrylic and methacrylic.
  • acrylic polymer used in the technique disclosed herein, a polymer of monomer components containing heptyl acrylate is used.
  • Acrylic polymers polymerized using monomer components containing heptyl acrylate are more flexible than polymers of other alkyl acrylates such as n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA).
  • Adhesives containing polymers tend to have a high value of -20°C tan ⁇ and tend to have excellent impact resistance. The reason for this is not to be construed as particularly limiting, but polymers containing heptyl acrylate as a monomer unit have a low glass transition temperature and a relatively large space between the main chains within the adhesive.
  • n-heptyl acrylate is preferred from the viewpoint of flexibility.
  • Acrylic polymers synthesized containing n-heptyl acrylate as a monomer component are considered to have relatively long linear side chains, and therefore tend to have larger spaces between main chains.
  • the proportion of heptyl acrylate in the monomer components of the acrylic polymer is 50% by weight or more (for example, more than 50% by weight), preferably 70% by weight or more, more preferably 80% by weight or more.
  • the content is more preferably 85% by weight or more, particularly preferably 90% by weight or more, may be 92% by weight or more, may be 94% by weight or more, may be 95% by weight or more, and may be 96% by weight or more.
  • the upper limit of the proportion of heptyl acrylate in the monomer component is 100% by weight, and may be 99% by weight or less, or may be 98% by weight or less. From the viewpoint of copolymerizing the carboxyl group-containing monomer and other monomers, in some embodiments, the proportion of heptyl acrylate in the monomer components is less than 97% by weight. In some preferred embodiments, the proportion of heptyl acrylate in the monomer component is 96% by weight or less, may be 95% by weight or less, and may be 94% by weight or less. Limiting the proportion of heptyl acrylate within the above range is preferable in terms of improving storage modulus, and may be advantageous in terms of improving repulsion resistance.
  • the acrylic polymer may be copolymerized with an alkyl (meth)acrylate (hereinafter also referred to as "optional alkyl (meth)acrylate”) other than heptyl acrylate.
  • an alkyl (meth)acrylate hereinafter also referred to as "optional alkyl (meth)acrylate
  • a compound represented by the following formula (1) can be suitably used.
  • CH 2 C(R 1 )COOR 2 (1)
  • R 1 in the above formula (1) is a hydrogen atom or a methyl group.
  • R 2 is a chain alkyl group having 1 to 20 carbon atoms (however, when R 1 is a hydrogen atom, a heptyl group is excluded).
  • optional alkyl (meth)acrylate examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s -Butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl methacrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl ( meth)acrylate, isononyl(meth)acrylate, decyl(meth)acrylate, isodecyl(meth)acrylate, undecyl(meth)acrylate, lauryl(meth)acryl
  • the proportion of heptyl acrylate in the total amount of alkyl (meth)acrylates contained in the monomer component is, for example, 50% by weight or more (specifically 50 to 100% by weight, for example, more than 50% by weight).
  • 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, particularly preferably 95% by weight or more may be 99% by weight or more, and may be 100% by weight. .
  • the technology disclosed herein it is possible to achieve both repulsion resistance and impact resistance based on the action of heptyl acrylate without relying on arbitrary alkyl (meth)acrylates such as 2EHA and BA. Therefore, the technology disclosed herein can be preferably practiced in an embodiment in which the monomer component does not substantially contain any alkyl (meth)acrylate.
  • the monomer component does not substantially contain monomer A (for example, the above-mentioned arbitrary alkyl (meth)acrylate), it means that the monomer A is not used, at least intentionally, and the monomer component is For example, unintentional inclusion of about 0.01% by weight or less is acceptable.
  • monomer A for example, the above-mentioned arbitrary alkyl (meth)acrylate
  • the monomer component may include an alkyl (meth)acrylate having a biomass-derived alkyl group at the ester end (hereinafter also referred to as "biomass alkyl (meth)acrylate”).
  • biomass alkyl (meth)acrylate having a biomass-derived alkyl group at the ester end
  • biomass alkyl (meth)acrylate it is possible to suitably realize an acrylic pressure-sensitive adhesive that is designed to reduce dependence on fossil resource-based materials.
  • the biomass alkyl (meth)acrylate is not particularly limited, and is, for example, an ester of a biomass-derived alkanol and a biomass-derived or non-biomass-derived (meth)acrylic acid.
  • alkanols derived from biomass include biomass ethanol, alkanols derived from plant materials such as palm oil, palm kernel oil, coconut oil, and castor oil.
  • the biomass-derived alkanol has three or more carbon atoms, the alkanol may be linear or branched.
  • an ester of a biomass-derived alkanol and a non-biomass-derived (meth)acrylic acid is used as the biomass alkyl (meth)acrylate used in the synthesis of the acrylic polymer.
  • biomass alkyl (meth)acrylate In such a biomass alkyl (meth)acrylate, the greater the number of carbon atoms in the alkanol, the greater the number ratio of biomass-derived carbon to the total number of carbons contained in the biomass alkyl (meth)acrylate, that is, the biomass carbon ratio of the alkyl (meth)acrylate. becomes higher. Therefore, in the above-mentioned biomass alkyl (meth)acrylate, it is desirable that the alkyl group derived from biomass has a large number of carbon atoms in order to reduce dependence on fossil resource materials.
  • biomass-derived heptyl acrylate (biomass heptyl acrylate) is used as the heptyl acrylate.
  • biomass heptyl acrylate is an ester of a biomass-derived alkanol and a biomass-derived or non-biomass-derived acrylic acid.
  • an ester of a biomass-derived alkanol and a non-biomass-derived acrylic acid can be used. In such compounds, only the heptyl groups are derived from biomass.
  • biomass-derived heptyl acrylate it is preferable to use biomass-derived n-heptyl acrylate (biomass n-heptyl acrylate).
  • the proportion of biomass alkyl (meth)acrylate (preferably biomass heptyl acrylate) in the monomer components of the acrylic polymer is, for example, 50% by weight or more (for example, more than 50% by weight), preferably 70% by weight or more, more preferably 80% by weight or more, further preferably 85% by weight or more, particularly preferably 90% by weight or more, may be 92% by weight or more, may be 94% by weight or more, and may be 96% by weight or more. good.
  • the proportion of biomass alkyl (meth)acrylate (preferably biomass heptyl acrylate) among the monomer components is less than 97% by weight, and in some embodiments may be 95% by weight or less, and may be 93% by weight or less. It may be 91% by weight or less.
  • the monomer component of the acrylic polymer contains a carboxyl group-containing monomer.
  • Carboxy group-containing monomers can improve cohesive force based on their polarity.
  • the carboxy group can serve as a crosslinking point of the acrylic polymer.
  • the 65° C. storage modulus of the adhesive can be improved, and it is easy to obtain an adhesive that has excellent repulsion resistance against a sustained load in the Z-axis direction.
  • a carboxy group-containing monomer better adhesion can be exhibited, for example, to an adherend such as a highly polar material.
  • Carboxy group-containing monomers include, for example, acrylic acid (AA), methacrylic acid (MAA), carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, crotonic acid, isocrotonic acid, and other ethylenically unsaturated monocarboxylic acids; maleic acid; acid, ethylenically unsaturated dicarboxylic acids such as itaconic acid and citraconic acid.
  • the carboxy group-containing monomer may be a monomer having a metal salt (for example, an alkali metal salt) of a carboxy group. Carboxy group-containing monomers can be used singly or in combination of two or more.
  • carboxy group-containing monomers include AA and MAA.
  • AA is particularly preferred.
  • the proportion of AA in the carboxy group-containing monomers is preferably 50% by weight or more, more preferably 70% by weight or more, and even more preferably 90% by weight or more. It is.
  • the carboxy group-containing monomer consists essentially of AA.
  • AA has a combination of functions such as polarity based on its carboxyl group, role as a crosslinking point, and Tg (106°C), so that in the carboxy group-containing monomer disclosed herein, AA has excellent impact resistance and long-lasting durability in the Z-axis direction. It is considered to be the optimal monomer material for achieving a good balance between load and repulsion resistance.
  • the proportion of the carboxyl group-containing monomer in the monomer component of the acrylic polymer is not particularly limited, and may be 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more, 2% by weight or more. It may be more than % by weight. In some preferred embodiments, the proportion of the carboxy group-containing monomer in the monomer component is more than 3% by weight (specifically more than 3.0% by weight), preferably 4.0% by weight or more, More preferably 4.5% by weight or more, still more preferably 5.0% by weight or more (for example, more than 5.0% by weight), particularly preferably 5.5% by weight or more, and 6.0% by weight or more. Good too.
  • the amount of the carboxy group-containing monomer is, for example, suitably 20% by weight or less of the total monomer components, preferably 15% by weight or less, and more preferably 12% by weight or less. In some preferred embodiments, the amount of the carboxy group-containing monomer may be 10% by weight or less, 8% by weight or less, 6% by weight or less, or 5% by weight or less.
  • the acrylic polymer may be copolymerized with a functional group-containing monomer (any functional group-containing monomer) other than the carboxy group-containing monomer.
  • a functional group-containing monomer any functional group-containing monomer
  • optional functional group-containing monomers that can introduce functional groups that can serve as crosslinking base points into acrylic polymers or contribute to improving adhesive strength include hydroxyl group (OH group)-containing monomers (2-hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- Hydroxyalkyl (meth)acrylates such as hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate; polypropylene glycol mono(meth)acrylate, etc.
  • OH group hydroxyl group
  • 2-hydroxyethyl (meth)acrylate 2-hydroxyethyl (meth)acrylate
  • acid anhydride group-containing monomers acid anhydride group-containing monomers, amide group-containing monomers ((meth)acrylamide, N,N-dimethyl(meth)acrylamide, etc.), amino group-containing monomers (aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, etc.), epoxy group-containing monomers, cyano group-containing monomers, keto group-containing monomers, monomers with nitrogen atom-containing rings (N-vinyl-2-pyrrolidone, N-(meth)acryloylmorpholine, etc.), alkoxysilyl Examples include group-containing monomers, imide group-containing monomers, and the like. The above arbitrary functional group-containing monomers can be used alone or in combination of two or more.
  • the content of the optional functional group-containing monomer in the monomer component is not particularly limited. From the viewpoint of appropriately exhibiting the effect of using the optional functional group-containing monomer, the content of the optional functional group-containing monomer in the monomer component can be, for example, 0.1% by weight or more, and 0.5% by weight or more. It is appropriate that the amount is 1% by weight or more.
  • the monomer component of the acrylic polymer includes heptyl acrylate and a monomer containing a carboxyl group
  • optional functional group-containing monomers in the monomer component may be used.
  • the content of is suitably 40% by weight or less, preferably 20% by weight or less, and may be 10% by weight or less (for example, 5% by weight or less).
  • the content of optional functional group-containing monomers in the monomer component is, for example, less than 3% by weight, may be less than 1% by weight, may be less than 0.5% by weight, and may be less than 0.3% by weight. % or less than 0.1% by weight.
  • the technique disclosed herein can be preferably carried out in an embodiment in which the monomer component of the acrylic polymer does not substantially contain any functional group-containing monomer.
  • a hydroxyl group-containing monomer may be used as the optional functional group-containing monomer.
  • the content of the hydroxyl group-containing monomer is suitably about 10% by weight or less (for example, 0.001 to 10% by weight), preferably about 5% by weight or less, more preferably about 5% by weight or less, based on the total monomer components. It is approximately 2% by weight or less.
  • the content of hydroxyl group-containing monomer in the monomer component may be less than 1% by weight, may be less than 0.5% by weight, may be less than 0.3% by weight, and may be less than 0.1% by weight. % or less than 0.01% by weight.
  • the monomer component of the acrylic polymer may be substantially free of hydroxyl group-containing monomers.
  • the monomer component of the acrylic polymer may be substantially free of hydroxyl group-containing monomers.
  • by limiting the amount of the hydroxyl group-containing monomer used or not using it it is possible to achieve both the predetermined 65°C storage modulus G' and -20°C tan ⁇ , and improve the repulsion resistance. It is possible to preferably achieve both a high level of impact resistance and impact resistance.
  • the ratio of the carboxy group-containing monomer to the total functional group-containing monomers (total functional group-containing monomers including the carboxy group-containing monomer) used as a copolymerization component of the acrylic polymer is determined by the effect of copolymerizing the carboxy group-containing monomer.
  • the content is suitably 30% by weight or more, preferably 50% by weight or more, more preferably 70% by weight or more, further preferably 80% by weight or more, particularly preferably 90% by weight or more, such as It may be 95% by weight or more, 97% by weight or more, 98% by weight or more, or 99% by weight or more (for example, 99.9% by weight or more).
  • the upper limit of the proportion of the carboxy group-containing monomer to the total of the functional group-containing monomers is 100% by weight, and may be, for example, 95% by weight or less.
  • the monomer components constituting the acrylic polymer may contain copolymerization components other than the above-mentioned functional group-containing monomers for the purpose of improving cohesive force and the like.
  • copolymerization components include vinyl ester monomers such as vinyl acetate; aromatic vinyl compounds such as styrene; cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, and isobornyl ) acrylates; aryl (meth)acrylates (e.g. phenyl (meth)acrylate), aryloxyalkyl (meth)acrylates (e.g.
  • Aromatic ring-containing (meth)acrylate Olefinic monomer; Chlorine-containing monomer; Isocyanate group-containing monomer such as 2-(meth)acryloyloxyethyl isocyanate; Alkoxy such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate Group-containing monomers; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; and the like.
  • the other copolymerization components mentioned above can be used alone or in combination of two or more.
  • the amount of such other copolymerized components is not particularly limited as long as it can be selected as appropriate depending on the purpose and use, but from the viewpoint of appropriately exhibiting the effects of use, it is appropriate to set it to 0.05% by weight or more. , 0.5% by weight or more.
  • the content of other copolymer components in the monomer component is 20% by weight or less, so that the adhesive properties based on the essential monomer components can be suitably exhibited. From this point of view, it is preferably 10% by weight or less, more preferably 8% by weight or less, still more preferably less than 5% by weight, for example, it may be less than 3% by weight, and may be less than 1% by weight.
  • the technology disclosed herein can also be preferably practiced in an embodiment in which the monomer component does not substantially contain other copolymer components.
  • Acrylic polymers are polyfunctional polymers that have at least two polymerizable functional groups (typically radically polymerizable functional groups) having unsaturated double bonds such as (meth)acryloyl groups and vinyl groups as other monomer components. It may also contain monomers. By using a polyfunctional monomer as a monomer component, the cohesive force of the adhesive layer can be increased. Polyfunctional monomers can be used as crosslinking agents.
  • the polyfunctional monomer is not particularly limited, and includes, for example, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and neopentyl glycol di(meth)acrylate. etc.
  • One type of polyfunctional monomer can be used alone or two or more types can be used in combination.
  • the amount of the polyfunctional monomer used is not particularly limited, and can be appropriately set so that the intended use of the polyfunctional monomer is achieved.
  • the amount of the polyfunctional monomer used can be about 3% by weight or less of the monomer components, preferably about 2% by weight or less, and more preferably about 1% by weight or less (for example, about 0.5% by weight or less).
  • the lower limit of the amount used when using a polyfunctional monomer is not particularly limited, as long as it is greater than 0% by weight.
  • the effect of using the polyfunctional monomer can be appropriately exhibited by setting the amount of the polyfunctional monomer to be approximately 0.001% by weight or more (for example, approximately 0.01% by weight or more) of the monomer components.
  • the acrylic polymer is an acrylic polymer synthesized using a monomer component consisting essentially of heptyl acrylate (preferably n-heptyl acrylate) and a carboxy group-containing monomer (preferably acrylic acid). It will be done. According to the above monomer composition, the effects of heptyl acrylate and the carboxy group-containing monomer are effectively exhibited, and the prescribed 65°C storage modulus G' and -20°C tan ⁇ are compatible, and the repulsion resistance and impact resistance are achieved. It is possible to achieve a high level of compatibility with both.
  • the total proportion of heptyl acrylate and the carboxyl group-containing monomer in the monomer components is suitably 90% by weight or more (90 to 100% by weight), preferably 95% by weight or more, more preferably 99% by weight or more. % by weight or more, more preferably more than 99.5% by weight, particularly preferably more than 99.9% by weight (for example, more than 99.99% by weight), and the total proportion of heptyl acrylate and the carboxy group-containing monomer in the monomer components may be 100% by weight.
  • biomass carbon ratio of the monomer component constituting the acrylic polymer may be, for example, 1% or more, suitably 10% or more, preferably 30% or more, and more preferably is 50% or more (for example, more than 50%), may be 70% or more, may be 80% or more, or may be 90% to 100%.
  • the method for obtaining the acrylic polymer is not particularly limited, and various polymerization methods known as methods for synthesizing acrylic polymers such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization, and photopolymerization may be used. may be adopted as appropriate.
  • a solution polymerization method can be preferably employed.
  • a monomer supply method when performing solution polymerization a batch charging method in which all monomer raw materials are supplied at once, a continuous supply (dropping) method, a divided supply (dropping) method, etc. can be appropriately adopted.
  • the polymerization temperature can be selected as appropriate depending on the type of monomer and solvent used, the type of polymerization initiator, etc., and is, for example, about 20°C to 170°C (typically about 40°C to 140°C). Can be done.
  • the solvent (polymerization solvent) used for solution polymerization can be appropriately selected from conventionally known organic solvents.
  • aromatic compounds such as toluene (typically aromatic hydrocarbons); acetate esters such as ethyl acetate; aliphatic or alicyclic hydrocarbons such as hexane and cyclohexane; 1,2-dichloroethane, etc. halogenated alkanes; lower alcohols such as isopropyl alcohol (for example, monohydric alcohols having 1 to 4 carbon atoms); ethers such as tert-butyl methyl ether; ketones such as methyl ethyl ketone; etc. Any one type of solvent or a mixed solvent of two or more types can be used.
  • the initiator used for polymerization can be appropriately selected from conventionally known polymerization initiators depending on the type of polymerization method.
  • one or more azo polymerization initiators such as 2,2'-azobisisobutyronitrile (AIBN) can be preferably used.
  • Other examples of polymerization initiators include persulfates such as potassium persulfate; peroxide initiators such as benzoyl peroxide (BPO) and hydrogen peroxide; substituted ethane initiators such as phenyl-substituted ethane; aromatic carbonyl compounds; and the like.
  • Still another example of the polymerization initiator is a redox initiator using a combination of a peroxide and a reducing agent.
  • Such polymerization initiators can be used alone or in combination of two or more.
  • the amount of the polymerization initiator used may be any normal amount, for example, approximately 0.005 to 1 part by weight (typically approximately 0.01 to 1 part by weight) per 100 parts by weight of all monomer components. degree).
  • the weight average molecular weight (Mw) of the acrylic polymer is not particularly limited, and an acrylic polymer having an appropriate Mw that satisfies the above-mentioned 65°C storage modulus and -20°C tan ⁇ is used.
  • the Mw of the acrylic polymer may be greater than 600,000, greater than 650,000, suitably greater than 700,000, and may be greater than 750,000. The larger the Mw of the acrylic polymer, the easier it is to obtain a pressure-sensitive adhesive that exhibits good cohesive force, and the repulsion resistance tends to improve.
  • the Mw of the acrylic polymer is 800,000 or more, may be 850,000 or more, may be 900,000 or more, more preferably 1 million or more (for example, more than 1 million), and even more preferably The number is 1.2 million or more, particularly preferably 1.4 million or more, may be 1.5 million or more, or may be 1.6 million or more.
  • the viscosity can be easily maintained at a low level, so the synthesis of the polymer is good, and an acrylic polymer having the above Mw can be easily obtained.
  • the Mw of the acrylic polymer is usually approximately 3 million or less, preferably 2.5 million or less, and more preferably 2 million or less. , more preferably 1.8 million or less, may be 1.5 million or less, or may be 1.3 million or less. In some preferred embodiments, the Mw of the acrylic polymer may be 1.1 million or less, 1 million or less, 950,000 or less, or 900,000 or less.
  • the Mw of the acrylic polymer can be measured by gel permeation chromatography (GPC) and determined as a value in terms of standard polystyrene. Specifically, it can be determined by measuring under the following conditions using a GPC measurement device with the trade name "HLC-8220GPC" (manufactured by Tosoh Corporation). The same applies to the embodiments described below.
  • GPC gel permeation chromatography
  • the adhesive layer includes a tackifying resin.
  • a tackifying resin By using a tackifying resin, high adhesive strength can be obtained.
  • the adhesive layer has a composition containing a tackifying resin and has predetermined viscoelastic properties (specifically, 65°C storage modulus G' and -20°C tan ⁇ ), It can exhibit excellent repulsion resistance in the Z-axis direction.
  • the effect of using a tackifier resin can be effectively exhibited in a composition containing a high molecular weight acrylic polymer.
  • the tackifier resin is not particularly limited and includes, for example, rosin-based tackifier resin, terpene-based tackifier resin, hydrocarbon-based tackifier resin, epoxy-based tackifier resin, polyamide-based tackifier resin, elastomer-based tackifier resin, Various tackifying resins such as phenolic tackifying resins and ketone tackifying resins can be used. Such tackifying resins can be used alone or in combination of two or more.
  • rosin-based tackifying resins include unmodified rosin (raw rosin) such as gum rosin, wood rosin, and tall oil rosin; Examples include hydrogenated rosin, disproportionated rosin, polymerized rosin, other chemically modified rosin, etc. (the same applies hereinafter); and other various rosin derivatives.
  • unmodified rosin raw rosin
  • examples include hydrogenated rosin, disproportionated rosin, polymerized rosin, other chemically modified rosin, etc. (the same applies hereinafter); and other various rosin derivatives.
  • examples of the above-mentioned rosin derivatives include rosins such as those obtained by esterifying unmodified rosin with alcohols (i.e., esterified products of rosin), and those obtained by esterifying modified rosin with alcohols (i.e., esterified products of modified rosin).
  • Esters Unsaturated fatty acid-modified rosins, which are unmodified rosin or modified rosin modified with unsaturated fatty acids; Unsaturated fatty acid-modified rosin esters, which are rosin esters modified with unsaturated fatty acids; Unmodified rosin, modified rosin, unsaturated Rosin alcohols obtained by reducing the carboxyl group in fatty acid-modified rosins or unsaturated fatty acid-modified rosin esters; metal salts of rosins (especially rosin esters) such as unmodified rosins, modified rosins, and various rosin derivatives; rosins; Examples include rosin phenol resins obtained by adding phenol to (unmodified rosin, modified rosin, various rosin derivatives, etc.) with an acid catalyst and thermally polymerizing them. Among these, rosin ester is preferred.
  • rosin esters include, but are not limited to, esters of unmodified rosin or modified rosin (hydrogenated rosin, disproportionated rosin, polymerized rosin, etc.), such as methyl ester, triethylene glycol ester, glycerin ester. , pentaerythritol ester and the like.
  • terpene-based tackifying resins examples include terpene resins such as ⁇ -pinene polymer, ⁇ -pinene polymer, and dipentene polymer; Modified terpene resins (modified etc.); etc.
  • modified terpene resin is terpene phenol resin.
  • Terpene phenol resin refers to a polymer containing terpene residues and phenol residues, and includes copolymers of terpenes and phenol compounds (terpene-phenol copolymer resins), and homopolymers or copolymers of terpenes. This concept includes both phenol-modified products (phenol-modified terpene resins). Specific examples of terpenes constituting such terpene phenol resin include monoterpenes such as ⁇ -pinene, ⁇ -pinene, and limonene (including d-form, l-form, and d/l-form (dipentene)); can be mentioned.
  • the hydrogenated terpene phenol resin refers to a hydrogenated terpene phenol resin having a structure obtained by hydrogenating such a terpene phenol resin. Sometimes called hydrogenated terpene phenolic resin.
  • hydrocarbon-based tackifier resins examples include aliphatic (C5-based) petroleum resins, aromatic (C9-based) petroleum resins, aliphatic/aromatic copolymerized (C5/C9-based) petroleum resins, and Hydrogenated substances (e.g., alicyclic petroleum resins obtained by hydrogenating aromatic petroleum resins), various modified products thereof (e.g., maleic anhydride modified products), coumaron-based resins, coumaron-indene-based resins Examples include various hydrocarbon resins such as.
  • the total proportion of the rosin-based tackifying resin and the terpene-based tackifying resin in the entire tackifying resin contained in the adhesive layer is, for example, approximately more than 50% by weight (more than 50% by weight and less than 100% by weight). ), and may be about 70% by weight or more, about 80% by weight or more, about 90% by weight or more, about 95% by weight or more, or about 99% by weight or more.
  • Some preferred embodiments include embodiments in which the tackifying resin contains one or more terpene phenol resins.
  • the technology disclosed herein can be preferably implemented, for example, in an embodiment in which about 25% by weight or more (more preferably about 30% by weight or more) of the total amount of tackifying resin is a terpene phenol resin.
  • the proportion of the terpene phenol resin in the total amount of tackifying resin may be approximately 50% by weight or more, approximately 70% by weight or more, approximately 80% by weight or more, or approximately 90% by weight or more.
  • Substantially all of the tackifying resin (for example, about 95% to 100% by weight, and even about 99% to 100% by weight) may be a terpene phenol resin.
  • the content of the terpene phenol resin in the adhesive layer is not particularly limited as long as it satisfies the desired viscoelastic properties.
  • the content of the terpene phenol resin is usually about 1 part by weight or more, and suitably about 5 parts by weight or more, based on 100 parts by weight of the acrylic polymer, from the viewpoint of improving adhesive strength.
  • the amount is preferably about 8 parts by weight or more, more preferably about 10 parts by weight or more, and even more preferably about 12 parts by weight or more (for example, 15 parts by weight or more).
  • the content of the terpene phenol resin in the adhesive layer is, for example, 70 parts by weight or less, may be 60 parts by weight or less, and may be 50 parts by weight or less, based on 100 parts by weight of the acrylic polymer. It may be less than parts by weight.
  • the content of the terpene phenol resin is 40 parts by weight or less, more preferably 30 parts by weight or less, still more preferably 25 parts by weight or less, particularly preferably 20 parts by weight or less. It is not more than 18 parts by weight, and may be not more than 18 parts by weight.
  • the tackifier resin may include a tackifier resin (eg, terpene phenol resin) having a hydroxyl value higher than 20 mgKOH/g.
  • the hydroxyl value of such a tackifying resin may be 30 mgKOH/g or more.
  • tackifying resins having a hydroxyl value of 50 mgKOH/g or more are preferred.
  • a tackifier resin having a hydroxyl value of 50 mgKOH/g or more may be referred to as a "high hydroxyl value resin".
  • the tackifier resin containing such a high hydroxyl value resin in addition to the adhesive force, an adhesive layer having high cohesive force can be realized by interacting with a crosslinking agent such as an isocyanate-based crosslinking agent.
  • the tackifying resin may include a high hydroxyl value resin having a hydroxyl value of 60 mgKOH/g or more (more preferably 70 mgKOH/g or more).
  • the above-mentioned high hydroxyl value resin (for example, terpene phenol resin) is preferably used in combination with an acrylic polymer containing heptyl acrylate as a monomer component, and has good adhesive strength and Z It can exhibit repulsion resistance against sustained loads in the axial direction.
  • the upper limit of the hydroxyl value of the high hydroxyl value resin is not particularly limited. From the viewpoint of compatibility with the acrylic polymer, the hydroxyl value of the high hydroxyl value resin is usually about 300 mgKOH/g or less, suitably about 200 mgKOH/g or less, preferably about 180 mgKOH/g or less, or more. It is preferably about 160 mgKOH/g or less, more preferably about 140 mgKOH/g or less, and may be less than 120 mgKOH/g (for example, 110 mgKOH/g or less).
  • the tackifier resin includes a high hydroxyl value resin (for example, a terpene-based tackifier resin, preferably a terpene phenol resin) with a hydroxyl value of 50 to 200 mgKOH/g.
  • a high hydroxyl value resin having a hydroxyl value of 60 to 140 mgKOH/g can be preferably employed.
  • a value measured by the potentiometric titration method specified in JIS K0070:1992 can be adopted.
  • the specific measurement method is as shown below.
  • [Method for measuring hydroxyl value] 1.
  • Reagent (1) As the acetylation reagent, take about 12.5 g (about 11.8 mL) of acetic anhydride, add pyridine to make a total volume of 50 mL, and stir thoroughly. Alternatively, take about 25 g (about 23.5 mL) of acetic anhydride, add pyridine to make a total volume of 100 mL, stir thoroughly, and use.
  • (2) A 0.5 mol/L potassium hydroxide ethanol solution is used as the measurement reagent.
  • the high hydroxyl value resin among the various tackifier resins mentioned above, those having a hydroxyl value of a predetermined value or more can be used.
  • the high hydroxyl value resins can be used alone or in combination of two or more.
  • a terpene phenol resin having a hydroxyl value of 50 mgKOH/g or more can be preferably employed as the high hydroxyl value resin.
  • Terpene phenol resins are advantageous because the hydroxyl value can be arbitrarily controlled by adjusting the copolymerization ratio of phenol.
  • the proportion of the high hydroxyl value resin for example, terpene phenol resin
  • the proportion of the high hydroxyl value resin in the entire tackifying resin should be approximately 5% by weight or more.
  • the content may be 10% by weight or more, 15% by weight or more, or 20% by weight or more.
  • the proportion of the high hydroxyl value resin in the entire tackifying resin is preferably about 30% by weight or more, for example.
  • the proportion of the high hydroxyl value resin in the entire tackifying resin is about 40% by weight or more, and may be about 50% by weight or more (for example, more than 50% by weight), and about 60% by weight. % or more, approximately 70% by weight or more, approximately 80% by weight or more, or approximately 90% by weight or more. Substantially all of the tackifying resin (for example, about 95 to 100% by weight, or even about 99 to 100% by weight) may be a high hydroxyl value resin.
  • the softening point of the above-mentioned high hydroxyl value resin is not particularly limited.
  • the softening point of the high hydroxyl value resin may be, for example, approximately 50°C or higher, and from the viewpoint of improving cohesive force, a high hydroxyl value resin having a softening point (softening temperature) of approximately 80°C or higher may be preferably employed.
  • a terpene phenol resin having such a softening point can be preferably used.
  • the softening point of the high hydroxyl value resin may be approximately 100°C or higher, or approximately 110°C or higher.
  • the softening point of the high hydroxyl value resin is approximately 120°C or higher, may be approximately 130°C or higher, or may be approximately 135°C or higher (or even approximately 140°C or higher).
  • the upper limit of the softening point of the high hydroxyl value resin is not particularly limited. From the viewpoint of adhesion to the adherend, a high hydroxyl value resin having a softening point of approximately 200° C. or lower (more preferably approximately 180° C. or lower) may be preferably used. In some embodiments, the high hydroxyl value resin may have a softening point of less than 160°C.
  • a high hydroxyl value resin having a softening point of less than 150°C is used as the high hydroxyl value resin.
  • a high hydroxyl value resin with a softening point of less than 150° C. it is possible to preferably obtain an adhesive that has both repulsion resistance and impact resistance, and also has excellent adhesive strength.
  • the softening point of the high hydroxyl value resin may be 145°C or lower.
  • the softening point of the tackifier resin in this specification is defined as a value measured based on the softening point test method (ring and ball method) specified in JIS K5902 and JIS K2207. Specifically, the sample is melted as quickly as possible at the lowest possible temperature, and the sample is carefully filled into a ring placed on a flat metal plate, taking care not to form bubbles. After it has cooled down, use a slightly heated knife to cut off the raised part from the plane including the top of the ring.
  • a supporter (ring stand) is placed in a glass container (heating bath) with a diameter of 85 mm or more and a height of 127 mm or more, and glycerin is poured into the container to a depth of 90 mm or more.
  • the steel ball (diameter 9.5 mm, weight 3.5 g) and the ring filled with the sample were immersed in glycerin without coming into contact with each other, and the temperature of the glycerin was maintained at 20°C plus or minus 5°C for 15 minutes. .
  • a steel ball is then placed in the center of the surface of the sample in the ring and placed in position on the support.
  • thermometer place a thermometer, set the center of the mercury bulb of the thermometer at the same height as the center of the ring, and heat the container.
  • the flame of the Bunsen burner used for heating should be halfway between the center of the bottom of the container and the edge to ensure even heating. Note that the rate at which the bath temperature increases after heating starts and reaches 40°C must be 5.0 plus or minus 0.5°C per minute.
  • the sample gradually softens and flows down from the ring, and the temperature at which it finally touches the bottom plate is read, and this is taken as the softening point.
  • the softening point is measured at two or more points at the same time, and the average value is used.
  • the content of the high hydroxyl value resin in the adhesive layer is not particularly limited as long as it satisfies the desired viscoelastic properties.
  • the content of the high hydroxyl value resin is usually about 1 part by weight or more, and can be about 5 parts by weight or more, based on 100 parts by weight of the acrylic polymer, from the viewpoint of improving adhesive strength. It is suitable, preferably about 8 parts by weight or more, more preferably about 10 parts by weight or more, still more preferably about 12 parts by weight or more (for example, 15 parts by weight or more).
  • the content of the high hydroxyl value resin in the adhesive layer is, for example, 70 parts by weight or less, and may be 60 parts by weight or less, based on 100 parts by weight of the acrylic polymer. It may be 50 parts by weight or less.
  • the content of the high hydroxyl value resin is 40 parts by weight or less, more preferably 30 parts by weight or less, still more preferably 25 parts by weight or less, particularly preferably It is 20 parts by weight or less, and may be 18 parts by weight or less.
  • the tackifying resin may include a tackifying resin having a hydroxyl value of less than 50 mgKOH/g.
  • a tackifier resin having a hydroxyl value of less than 50 mgKOH/g may be referred to as a "low hydroxyl value resin”.
  • low hydroxyl value resins are preferably used in combination with high hydroxyl value resins.
  • the hydroxyl value of the low hydroxyl value resin may be less than 40 mgKOH/g.
  • the lower limit of the hydroxyl value of the low hydroxyl value resin is 0 mgKOH/g or more, may be about 10 mgKOH/g or more, or may be about 15 mgKOH/g or more.
  • the low hydroxyl value resin one type suitably selected from among the tackifier resins exemplified above having a hydroxyl value of less than 50 mgKOH/g can be used alone or in combination of two or more types.
  • the low hydroxyl value resin preferably includes a rosin-based tackifying resin.
  • the low hydroxyl value resin may contain one type of rosin-based tackifier resin alone, or may contain a combination of two or more types of rosin-based tackifier resin.
  • the proportion of the rosin-based tackifier resin in the entire low hydroxyl value resin can be, for example, about 50% by weight or more, about 65% by weight or more, or about 75% by weight or more.
  • the content may be 85% by weight or more, or may be 95% by weight or more.
  • the technology disclosed herein is an embodiment in which substantially all of the low hydroxyl value resin (for example, approximately 97% by weight or more, or 99% by weight or more, and may be 100% by weight) is a rosin-based tackifying resin. It can be preferably implemented.
  • the softening point of the above-mentioned low hydroxyl value resin is not particularly limited. From the viewpoint of improving cohesive force, a low hydroxyl value resin having a softening point (softening temperature) of about 80° C. or higher can be preferably employed. For example, a rosin-based tackifying resin having such a softening point can be preferably used.
  • the softening point of the low hydroxyl value resin may be approximately 100°C or higher, approximately 110°C or higher, or approximately 120°C or higher.
  • the upper limit of the softening point of the low hydroxyl value resin is not particularly limited. From the viewpoint of adhesion to the adherend, a low hydroxyl value resin having a softening point of about 200° C.
  • the softening point of the low hydroxyl value resin may be about 160°C or less, about 150°C or less (eg, less than 150°C), about 140°C or less, or about 130°C or less.
  • the tackifying resin is a tackifying resin T L having a softening point of less than 150°C.
  • the softening point of the tackifier resin T L may be 145° C. or lower.
  • the lower limit of the softening point of the tackifier resin T L is not particularly limited.
  • the softening point of the tackifier resin T L may be, for example, approximately 50°C or higher, preferably approximately 80°C or higher, and more preferably approximately 100°C or higher, from the viewpoint of exhibiting appropriate cohesive force. , more preferably about 110°C or higher.
  • the softening point of the tackifier resin is approximately 120°C or higher, may be 130°C or higher, or may be 135°C or higher (or even approximately 140°C or higher).
  • the tackifier resin T L one type suitably selected from among the tackifier resins exemplified above having a softening point of less than 150°C can be used alone or in combination of two or more types.
  • the tackifying resin T L preferably comprises a terpene phenolic resin.
  • the tackifier resin T L may contain one type of terpene phenol resin alone, or may contain a combination of two or more types of terpene phenol resin.
  • the proportion of the terpene phenol resin in the entire tackifier resin T L can be, for example, more than about 50% by weight, may be about 65% by weight or more, and may be about 75% by weight or more. , 85% by weight or more, or 95% by weight or more.
  • the technology disclosed herein is preferably in an embodiment in which substantially all of the tackifier resin T L (for example, approximately 97% by weight or more, or 99% by weight or more, and may be 100% by weight) is a terpene phenol resin. can be implemented.
  • tackifying resin T L for example, a tackifying resin having a softening point of less than 50°C, more preferably approximately 40°C or less (typically a rosin-based, terpene-based, hydrocarbon-based, etc. tackifying resin, e.g. Hydrogenated rosin methyl ester, etc.) may or may not be included.
  • a low softening point tackifier resin may be a liquid tackifier resin that exhibits a liquid state at 30°C.
  • the liquid tackifying resin can be used alone or in combination of two or more.
  • the content of the liquid tackifying resin can be approximately 30% by weight or less of the entire tackifier resin T L from the viewpoint of cohesive force etc., and should be approximately 10% by weight or less (for example, 0 to 10% by weight). is suitable, and may be approximately 2% by weight or less (0.5 to 2% by weight), and may be less than 1% by weight.
  • the content of the tackifier resin T L is not particularly limited, but in some embodiments, it is appropriate to set it to about 70 parts by weight or less based on 100 parts by weight of the acrylic polymer.
  • the amount of the tackifier resin T L used is suitably 60 parts by weight or less, preferably 50 parts by weight, based on 100 parts by weight of the acrylic polymer, from the viewpoint of impact resistance etc.
  • the amount is not more than 40 parts by weight, more preferably not more than 40 parts by weight, may be not more than 30 parts by weight, not more than 25 parts by weight, not more than 20 parts by weight, and not more than 18 parts by weight.
  • the amount of the tackifier resin T L used is, for example, 1 part by weight or more, preferably 5 parts by weight or more, based on 100 parts by weight of the acrylic polymer.
  • the amount is preferably 8 parts by weight or more, more preferably 10 parts by weight or more, still more preferably 12 parts by weight or more, and may be 15 parts by weight or more.
  • the acrylic polymer containing heptyl acrylate as a monomer unit used in the technology disclosed herein has good compatibility with the tackifier resin, so it is possible to achieve desired characteristics by incorporating an appropriate amount of the tackifier resin. can.
  • the adhesive layer may include a combination of a tackifying resin T L and a tackifying resin T H having a softening point of 150° C. or higher (eg, 150° C. to 200° C.).
  • a tackifying resin T H having a softening point of 150° C. or higher (eg, 150° C. to 200° C.).
  • the tackifier resin T H one kind or a combination of two or more kinds of tackifier resins having a softening point of 150° C. or more among the tackifier resins exemplified above can be used.
  • the tackifier resin T L accounts for more than 50% by weight of the total amount of tackifier resins included in the adhesive layer. Thereby, the effect of containing the tackifying resin TL tends to be effectively expressed.
  • the proportion of the tackifying resin T L in the total amount of the tackifying resin contained in the adhesive layer is preferably 60% by weight or more, more preferably The content is 70% by weight or more, more preferably 80% by weight or more, particularly preferably 90% by weight or more, may be 95% by weight or more, or may be 98% by weight or more.
  • the tackifier resin contained in the adhesive layer consists essentially only of tackifier resin TL . In this embodiment, the proportion of the tackifying resin T L in the total amount of tackifying resin contained in the adhesive layer is in the range of 99 to 100% by weight.
  • the softening point of the tackifying resin is not particularly limited. From the viewpoint of improving cohesive force, a tackifier resin having a softening point (softening temperature) of about 80° C. or higher can be preferably employed. For example, a terpene-based tackifying resin (such as a terpene phenol resin) having such a softening point can be preferably used.
  • the softening point of the tackifying resin may be approximately 100°C or higher, or approximately 110°C or higher. In some preferred embodiments, the softening point of the tackifier resin is approximately 120°C or higher, may be approximately 130°C or higher, or may be approximately 135°C or higher (or even approximately 140°C or higher).
  • a terpene phenol resin having the above-mentioned softening point it is preferable to use a terpene phenol resin having the above-mentioned softening point.
  • the upper limit of the softening point of the tackifying resin is not particularly limited. From the viewpoint of adhesion to the adherend, a tackifying resin having a softening point of approximately 200° C. or lower (more preferably approximately 180° C. or lower) may be preferably used. In some embodiments, the softening point of the tackifying resin may be less than 160°C, and may be less than 150°C.
  • the tackifier resin is preferably a tackifier resin derived from plants (vegetable tackifier resin) from the viewpoint of improving the biomass carbon ratio of the adhesive layer. It can work.
  • vegetable tackifying resins include the above-mentioned rosin-based tackifying resins and terpene-based tackifying resins.
  • the vegetable tackifying resins can be used alone or in combination of two or more.
  • the proportion of the vegetable tackifying resin in the total amount of the tackifying resin is 30% by weight or more (for example, 50% by weight or more, typically 80% by weight). above) is preferable.
  • the proportion of vegetable tackifying resin in the total amount of tackifying resin is 90% by weight or more (eg, 95% by weight or more, typically 99-100% by weight).
  • the technology disclosed herein can be preferably implemented in an embodiment that does not substantially contain tackifying resins other than vegetable tackifying resins.
  • the content of the tackifying resin in the adhesive layer is not particularly limited as long as it satisfies the desired viscoelastic properties.
  • the content of the tackifier resin is usually about 1 part by weight or more, and suitably about 5 parts by weight or more, based on 100 parts by weight of the acrylic polymer, from the viewpoint of improving adhesive strength.
  • the amount is preferably about 8 parts by weight or more, more preferably about 10 parts by weight or more, and even more preferably about 12 parts by weight or more (for example, 15 parts by weight or more).
  • the content of the tackifier resin in the adhesive layer is, for example, 70 parts by weight or less, may be 60 parts by weight or less, and may be 50 parts by weight or less, based on 100 parts by weight of the acrylic polymer. It may be less than parts by weight. In some preferred embodiments, from the viewpoint of repulsion resistance, the content of the tackifying resin is 40 parts by weight or less, more preferably 30 parts by weight or less, still more preferably 25 parts by weight or less, particularly preferably 20 parts by weight or less. It is not more than 18 parts by weight, and may be not more than 18 parts by weight.
  • the acrylic polymer containing heptyl acrylate as a monomer unit used in the technology disclosed herein has good compatibility with the tackifying resin, so it is possible to achieve desired characteristics by incorporating an appropriate amount of the tackifying resin. can.
  • the adhesive layer contains an acrylic oligomer.
  • the adhesive force of the pressure-sensitive adhesive can be improved.
  • the adhesive layer has a composition containing an acrylic oligomer and has predetermined viscoelastic properties (specifically, 65°C storage modulus G' and -20°C tan ⁇ ), It can exhibit excellent repulsion resistance in the Z-axis direction.
  • the effect of using an acrylic oligomer can be effectively exhibited in a composition containing a high molecular weight acrylic polymer.
  • the acrylic oligomer has a Tg of about 0°C or more and about 300°C or less, preferably about 20°C or more and about 300°C or less, and more preferably about 40°C or more and about 300°C or less.
  • Tg is within the above range, adhesive strength can be suitably improved.
  • the Tg of the acrylic oligomer is about 30°C or higher, more preferably about 50°C or higher (for example, about 60°C or higher), from the viewpoint of adhesive cohesiveness, and From this point of view, the temperature is preferably about 200°C or less, more preferably about 150°C or less, and even more preferably about 100°C or less (for example, about 80°C or less).
  • the Tg of the acrylic oligomer refers to the Tg determined by the Fox equation based on the composition of the monomer components.
  • Tg is the glass transition temperature of the copolymer (unit: K)
  • Wi is the weight fraction of monomer i in the copolymer (copolymerization ratio on a weight basis)
  • Tgi is the weight fraction of monomer i in the copolymer. Represents the glass transition temperature (unit: K) of a homopolymer.
  • the glass transition temperature of the homopolymer used to calculate Tg the value described in publicly known materials shall be used.
  • the values described in "Polymer Handbook” (3rd edition, John Wiley & Sons, Inc., 1989) are used.
  • the highest value is adopted.
  • the value obtained by the following measurement method shall be used. Specifically, 100 parts by weight of monomer, 0.2 parts by weight of 2,2'-azobisisobutyronitrile, and acetic acid as a polymerization solvent were placed in a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube, and a reflux condenser. Add 200 parts by weight of ethyl and stir for 1 hour while passing nitrogen gas. After removing oxygen in the polymerization system in this manner, the temperature was raised to 63° C. and the reaction was allowed to proceed for 10 hours.
  • a homopolymer solution with a solid content concentration of 33% by weight.
  • this homopolymer solution is cast onto a release liner and dried to produce a test sample (sheet-like homopolymer) with a thickness of about 2 mm.
  • This test sample was punched into a disk shape with a diameter of 7.9 mm, sandwiched between parallel plates, and subjected to shear strain at a frequency of 1 Hz using a viscoelasticity testing machine (manufactured by TA Instruments Japan, model name "ARES").
  • the viscoelasticity is measured in the shear mode at a temperature range of -70° C. to 150° C. and a heating rate of 5° C./min while giving the same temperature, and the temperature corresponding to the peak top temperature of tan ⁇ is taken as the Tg of the homopolymer.
  • the weight average molecular weight (Mw) of the acrylic oligomer is typically about 1,000 or more and less than about 30,000, preferably about 1,500 or more and less than about 20,000, and more preferably about 2,000 or more and less than about 10,000. It is preferable for Mw to be within the above range because good adhesive strength and repulsion resistance can be obtained.
  • the Mw of the acrylic oligomer is about 2,500 or more (for example, about 3,000 or more) from the viewpoint of repulsion resistance against sustained loads in the Z-axis direction, and from the viewpoint of adhesiveness, preferably It is about 7,000 or less, more preferably about 5,000 or less (eg, about 4,500 or less, typically about 4,000 or less).
  • the Mw of the acrylic oligomer can be measured by gel permeation chromatography (GPC) and determined as a value in terms of standard polystyrene. Specifically, the measurement is performed using HPLC8020 manufactured by Tosoh Corporation with two columns of TSKgelGMH-H (20) using tetrahydrofuran solvent at a flow rate of about 0.5 mL/min.
  • GPC gel permeation chromatography
  • Examples of monomers constituting the acrylic oligomer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, and s-butyl.
  • (meth)acrylate t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate , isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate.
  • esters of (meth)acrylic acid and alicyclic alcohol such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate (alicyclic hydrocarbon group-containing (meth)acrylate)
  • Aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate
  • (meth)acrylates obtained from terpene compound derivative alcohols and the like.
  • Such (meth)acrylates can be used alone or in combination of two or more.
  • acrylic oligomers include alkyl (meth)acrylates in which the alkyl group has a branched structure, such as isobutyl (meth)acrylate and t-butyl (meth)acrylate; cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentaacrylate; Esters of (meth)acrylic acid and alicyclic alcohol such as nyl (meth)acrylate (alicyclic hydrocarbon group-containing (meth)acrylate); aryl such as phenyl (meth)acrylate and benzyl (meth)acrylate Containing as a monomer unit an acrylic monomer having a relatively bulky structure, such as (meth)acrylate having a cyclic structure, further improves the adhesiveness of the adhesive layer.
  • alkyl (meth)acrylates in which the alkyl group has a branched structure, such as isobutyl (meth)acrylate and t-
  • ultraviolet rays when synthesizing acrylic oligomers or preparing adhesive layers, it is preferable to use ultraviolet rays that have saturated bonds because they are less likely to inhibit polymerization, and those that have alkyl groups with a branched structure are preferable.
  • Alkyl (meth)acrylates or esters with alicyclic alcohols (alicyclic hydrocarbon group-containing (meth)acrylates) can be suitably used as monomers constituting the acrylic oligomer.
  • branched alkyl (meth)acrylates alicyclic hydrocarbon group (meth)acrylates, and aryl (meth)acrylates correspond to (meth)acrylate monomers in the technology disclosed herein.
  • the cycloaliphatic hydrocarbon group can be a saturated or unsaturated cycloaliphatic hydrocarbon group.
  • the proportion of (meth)acrylate monomers (for example, alicyclic hydrocarbon group-containing (meth)acrylates) in all monomer components constituting the acrylic oligomer is typically more than 50% by weight, preferably 60% by weight. % or more, more preferably 70 weight % or more (for example, 80 weight % or more, and even 90 weight % or more).
  • the acrylic oligomer has a monomer composition consisting essentially of (meth)acrylate monomers.
  • functional group-containing monomers can be used as constituent monomer components of the acrylic oligomer.
  • suitable examples of the functional group-containing monomer include monomers having a nitrogen atom-containing ring (typically a nitrogen atom-containing heterocycle) such as N-vinyl-2-pyrrolidone and N-acryloylmorpholine; N,N-dimethylamino Amino group-containing monomers such as ethyl (meth)acrylate; amide group-containing monomers such as N,N-diethyl (meth)acrylamide; carboxy group-containing monomers such as AA and MAA; hydroxyl group-containing monomers such as 2-hydroxyethyl (meth)acrylate Monomers; These functional group-containing monomers can be used alone or in combination of two or more. Among these, carboxy group-containing monomers are preferred, and AA is particularly preferred.
  • the proportion of the functional group-containing monomer (for example, a carboxyl group-containing monomer such as AA) in all the monomer components is approximately 1% by weight or more.
  • the content is preferably 2% by weight or more, more preferably 3% by weight or more, and approximately 15% by weight or less, preferably 10% by weight or less, more preferably 7% by weight. It is as follows.
  • the acrylic oligomer can be formed by polymerizing its constituent monomer components.
  • the polymerization method and polymerization mode are not particularly limited, and various conventionally known polymerization methods (e.g., solution polymerization, emulsion polymerization, bulk polymerization, photopolymerization, radiation polymerization, etc.) can be employed in an appropriate mode.
  • the types of polymerization initiators for example, azo polymerization initiators such as AIBN
  • AIBN azo polymerization initiators
  • the amount of the chain transfer agent such as n-dodecyl mercaptan is appropriately determined based on common technical knowledge so as to obtain a desired molecular weight, and therefore detailed explanation will be omitted here.
  • suitable acrylic oligomers include, for example, dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), dicyclopentanyl
  • DCPA dicyclopentanyl methacrylate
  • ADMA 1-adamantyl methacrylate
  • ADA 1-adamantyl acrylate
  • a copolymer of CHMA and isobutyl methacrylate (IBMA) a copolymer of CHMA and IBXMA
  • CAA copolymer of CHMA and diethylacrylamide
  • MMA copolymer of CHMA and AA
  • the content is preferably, for example, 0.1 part by weight or more (for example, 1 part by weight or more) based on 100 parts by weight of the acrylic polymer. It is. From the viewpoint of better exhibiting the effects of the acrylic oligomer, the content of the acrylic oligomer is preferably about 5 parts by weight or more, more preferably about 8 parts by weight or more, still more preferably about 10 parts by weight or more, especially Preferably it is about 12 parts by weight or more. Further, from the viewpoint of compatibility with the acrylic polymer, it is appropriate that the content of the acrylic oligomer is less than 50 parts by weight (for example, less than 40 parts by weight) based on 100 parts by weight of the acrylic polymer. , preferably less than 30 parts by weight, more preferably about 25 parts by weight or less, still more preferably about 20 parts by weight or less.
  • the adhesive layer contains one or more of the above-mentioned tackifier resins and one or more acrylic oligomers.
  • a composition containing an acrylic polymer containing heptyl acrylate as a monomer component by using a tackifier resin and an acrylic oligomer together, excellent adhesion can be obtained, while the usage mode is exposed to harsh conditions such as strong repulsion. Also, it can exhibit highly excellent repulsion resistance against sustained loads in the Z-axis direction.
  • a composition containing a high molecular weight acrylic polymer the effect of using a tackifying resin and an acrylic oligomer in combination can be effectively exhibited.
  • the ratio (C T /C O ) of the tackifying resin content C T [wt%] to the acrylic oligomer content C O [wt %] in the adhesive layer is not particularly limited.
  • the above (C T /C O ) is suitably set to, for example, 0.1 or more and 9 or less, preferably 0.25 or more and 4 or less, more preferably 0.4 or more and 2 or less, and even more preferably 0.7. It is not less than 1.5, and may be not less than 0.8 and not more than 1.2.
  • the total amount (total amount) of the tackifier resin and acrylic oligomer contained in the adhesive layer is 100 parts by weight of the acrylic polymer from the viewpoint of preferably exhibiting the effects of the technology disclosed herein. It is appropriate that the amount is approximately 1 part by weight or more, preferably approximately 10 parts by weight or more, more preferably approximately 16 parts by weight or more, still more preferably 20 parts by weight or more, particularly preferably 25 parts by weight or more. Further, it is appropriate that the amount is less than 120 parts by weight (for example, about 80 parts by weight or less), preferably less than 60 parts by weight, more preferably about 50 parts by weight or less, still more preferably about 40 parts by weight or less.
  • the total amount (total amount) of the acrylic polymer, tackifier resin, and acrylic oligomer in the adhesive layer is appropriately set so that the effect of the technology disclosed herein is exhibited, It is not limited to a specific range.
  • the total amount (total amount) of the acrylic polymer, tackifier resin, and acrylic oligomer contained in the adhesive layer is 50% by weight from the viewpoint of preferably exhibiting the effects of the technology disclosed herein.
  • it is about 70% by weight or more, more preferably about 90% by weight or more, even more preferably 95% by weight or more (for example, 95% by weight or more and 100% by weight or less, or less than 100% by weight). It may be 98% by weight or more.
  • the adhesive composition used to form the adhesive layer may contain a crosslinking agent as necessary.
  • the type of crosslinking agent is not particularly limited, and examples include isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, and metals. Examples include alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, hydrazine crosslinking agents, amine crosslinking agents, and silane coupling agents.
  • crosslinking agent can be used alone or two or more types can be used in combination. Among these, isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, and melamine crosslinking agents are preferred, and isocyanate crosslinking agents and epoxy crosslinking agents are more preferred.
  • the adhesive layer can obtain cohesive force, improve repulsion resistance, and preferably achieve both repulsion resistance and impact resistance.
  • the adhesive layer in the technology disclosed herein may contain the crosslinking agent in a form after a crosslinking reaction, a form before a crosslinking reaction, a partially crosslinked form, an intermediate or composite form thereof, etc. May contain.
  • the crosslinking agent is typically contained in the adhesive layer exclusively in the form after crosslinking reaction.
  • polyfunctional isocyanates referring to compounds having an average of two or more isocyanate groups per molecule, including those having an isocyanurate structure
  • the isocyanate crosslinking agents can be used alone or in combination of two or more.
  • polyfunctional isocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, and the like.
  • aliphatic polyisocyanates include 1,2-ethylene diisocyanate; tetramethylene diisocyanates such as 1,2-tetramethylene diisocyanate, 1,3-tetramethylene diisocyanate, and 1,4-tetramethylene diisocyanate; 1,2-tetramethylene diisocyanate; - hexamethylene diisocyanate such as hexamethylene diisocyanate, 1,3-hexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, 1,5-hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,5-hexamethylene diisocyanate; Examples include 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, ly
  • alicyclic polyisocyanates include isophorone diisocyanate; cyclohexyl diisocyanates such as 1,2-cyclohexyl diisocyanate, 1,3-cyclohexyl diisocyanate, and 1,4-cyclohexyl diisocyanate; 1,2-cyclopentyl diisocyanate, and 1,3-cyclohexyl diisocyanate; -Cyclopentyl diisocyanates such as cyclopentyl diisocyanate; hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethylxylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and the like.
  • aromatic polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'-diphenylmethane diisocyanate.
  • polyfunctional isocyanates examples include polyfunctional isocyanates having an average of three or more isocyanate groups per molecule.
  • Such trifunctional or higher functional isocyanates are polymers (typically dimers or trimers) of bifunctional or trifunctional or higher functional isocyanates, derivatives (for example, a combination of a polyhydric alcohol and two or more molecules of polyfunctional isocyanate). addition reaction products), polymers, etc.
  • dimers and trimers of diphenylmethane diisocyanate dimers and trimers of diphenylmethane diisocyanate, isocyanurates of hexamethylene diisocyanate (trimeric adducts of isocyanurate structures), reaction products of trimethylolpropane and tolylene diisocyanate, and products of the reaction between trimethylolpropane and hexamethylene diisocyanate.
  • polyfunctional isocyanates such as reaction products with methylene diisocyanate, polymethylene polyphenylisocyanate, polyether polyisocyanate, and polyester polyisocyanate.
  • the technology disclosed herein can be preferably implemented in an embodiment in which at least an isocyanate-based crosslinking agent is used as a crosslinking agent.
  • an isocyanate-based crosslinking agent By using an isocyanate-based crosslinking agent, it is possible to preferably obtain repulsion resistance against a sustained load in the Z-axis direction.
  • the amount of the isocyanate crosslinking agent used is not particularly limited.
  • the amount can be approximately 0.1 part by weight or more per 100 parts by weight of the acrylic polymer.
  • the amount of isocyanate crosslinking agent used per 100 parts by weight of the acrylic polymer should usually be approximately 0.3 parts by weight or more (for example, 0.5 parts by weight or more). is preferred.
  • the amount of the isocyanate crosslinking agent used per 100 parts by weight of the acrylic polymer is about 0.8 parts by weight or more, more preferably about 1.0 parts by weight or more, and still more preferably about 1.2 parts by weight.
  • the amount may be at least 1.5 parts by weight, and may be approximately 1.5 parts by weight or more.
  • the amount of the isocyanate crosslinking agent used is suitably 10 parts by weight or less per 100 parts by weight of the acrylic polymer, preferably less than 5 parts by weight, more preferably less than 4.0 parts by weight, It is more preferably less than 3.0 parts by weight, particularly preferably 2.5 parts by weight or less, and may be less than 2.0 parts by weight (eg, 1.7 parts by weight or less).
  • amount of isocyanate-based crosslinking agent used within a predetermined range, it is possible to achieve both repulsion resistance and impact resistance while obtaining repulsion resistance against sustained loads in the Z-axis direction based on the use of isocyanate-based crosslinking agents. can be preferably realized.
  • epoxy crosslinking agent any compound having two or more epoxy groups in one molecule can be used without particular limitation. Epoxy crosslinking agents having 3 to 5 epoxy groups in one molecule are preferred. The epoxy crosslinking agents can be used alone or in combination of two or more.
  • epoxy crosslinking agents include N,N,N',N'-tetraglycidyl-m-xylene diamine, 1,3-bis(N,N-diglycidylaminomethyl ) cyclohexane, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, polyglycerol polyglycidyl ether, and the like.
  • epoxy crosslinking agents include Mitsubishi Gas Chemical's product names “TETRAD-C” and “TETRAD-X”, DIC's product name “Epicron CR-5L”, and Nagase ChemteX's product name Examples include the product name “Denacol EX-512” manufactured by Nissan Chemical Industries, Ltd. and the product name "TEPIC-G” manufactured by Nissan Chemical Industries, Ltd.
  • the amount of the epoxy crosslinking agent used is not particularly limited.
  • the amount of the epoxy crosslinking agent used may be, for example, more than 0 parts by weight and no more than about 1 part by weight (typically about 0.001 to 1 part by weight) per 100 parts by weight of the acrylic polymer. can. From the viewpoint of suitably exhibiting the effect of improving cohesive force, it is usually appropriate to use the epoxy crosslinking agent in an amount of about 0.002 parts by weight or more per 100 parts by weight of the acrylic polymer, preferably It is about 0.005 parts by weight or more, and may be about 0.01 parts by weight or more, for example.
  • the amount of the epoxy crosslinking agent used is approximately 0.5 parts by weight or less per 100 parts by weight of the acrylic polymer, and approximately 0.2 parts by weight. It is preferably at most 0.1 part by weight (for example less than 0.1 part by weight), more preferably at most 0.07 part by weight, and may be at most 0.04 part by weight.
  • an isocyanate crosslinking agent and at least one crosslinking agent having a different type of crosslinkable functional group from the isocyanate crosslinking agent are used in combination.
  • a crosslinking agent other than an isocyanate crosslinking agent that is, a crosslinking agent having a different type of crosslinkable reactive group from the isocyanate crosslinking agent; hereinafter also referred to as a "non-isocyanate crosslinking agent"
  • repulsion resistance and impact resistance can be preferably achieved at the same time.
  • non-isocyanate crosslinking agent that can be used in combination with the isocyanate crosslinking agent is not particularly limited, and can be appropriately selected from the above-mentioned crosslinking agents.
  • the non-isocyanate crosslinking agents can be used alone or in combination of two or more.
  • an epoxy crosslinker can be employed as the non-isocyanate crosslinker.
  • an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent in combination it is possible to better achieve both repulsion resistance and impact resistance against a sustained load in the Z-axis direction.
  • the relationship between the content of the isocyanate-based crosslinking agent and the content of the non-isocyanate-based crosslinking agent is not particularly limited. is set to
  • the content of the isocyanate crosslinking agent is, for example, more than 1 time, preferably about 10 times or more, relative to the content of the non-isocyanate crosslinking agent (preferably an epoxy crosslinking agent). is about 50 times or more, more preferably about 80 times or more, still more preferably about 100 times or more (for example, more than 100 times), particularly preferably about 120 times or more (for example, about 140 times or more).
  • a non-isocyanate crosslinking agent preferably an epoxy crosslinking agent
  • the content of the isocyanate crosslinking agent relative to the content of the crosslinking agent (crosslinking agent) is, for example, approximately 1000 times or less, suitably approximately 500 times or less, preferably approximately 300 times or less, and more preferably approximately 200 times or less. , more preferably about 180 times or less (for example, about 160 times or less).
  • the content of crosslinking agent (total amount of crosslinking agent) in the adhesive composition disclosed herein is not particularly limited.
  • the content of the crosslinking agent is usually about 0.001 parts by weight or more, and preferably about 0.002 parts by weight or more, based on 100 parts by weight of the acrylic polymer.
  • it is about 0.005 part by weight or more, more preferably about 0.01 part by weight or more, still more preferably about 0.02 part by weight or more, particularly preferably about 0.03 part by weight or more.
  • the content of the crosslinking agent per 100 parts by weight of the acrylic polymer is about 0.1 parts by weight or more, more preferably about 0.5 parts by weight or more, and even more preferably about 1.0 parts by weight or more.
  • the amount may be about 1.2 parts by weight or more, or about 1.5 parts by weight or more.
  • the content of the crosslinking agent in the adhesive composition is usually about 20 parts by weight or less, preferably about 15 parts by weight or less, and about 10 parts by weight, based on 100 parts by weight of the acrylic polymer. It is preferable that the amount is less than (for example, about 5 parts by weight or less).
  • the content of the crosslinking agent per 100 parts by weight of the acrylic polymer is 4.0 parts by weight or less, more preferably 3.0 parts by weight or less, still more preferably 2.5 parts by weight or less,
  • the amount may be 2.0 parts by weight or less (for example, less than 2.0 parts by weight), or 1.8 parts by weight or less.
  • the adhesive composition may contain a leveling agent, a crosslinking aid, a plasticizer, a softener, a filler, a coloring agent (pigment, dye, etc.), an antistatic agent, and an antiaging agent, as necessary.
  • a leveling agent e.g., a plasticizer, a softener, a filler, a coloring agent (pigment, dye, etc.), an antistatic agent, and an antiaging agent, as necessary.
  • ultraviolet absorbers, antioxidants, rust preventives, light stabilizers, and other additives commonly used in the adhesive field e.g., ultraviolet absorbers, antioxidants, rust preventives, light stabilizers, and other additives commonly used in the adhesive field.
  • conventionally known ones can be used in a conventional manner, and since they do not particularly characterize the present invention, detailed explanations will be omitted.
  • the adhesive layer (layer consisting of an adhesive) disclosed herein is formed from a water-based adhesive composition, a solvent-based adhesive composition, a hot-melt adhesive composition, or an active energy ray-curable adhesive composition. It may be an adhesive layer.
  • the aqueous adhesive composition refers to an adhesive composition containing an adhesive (adhesive layer forming component) in a water-based solvent (aqueous solvent), and is typically a water-based adhesive composition. This includes what is called a type adhesive composition (a composition in which at least a portion of an adhesive is dispersed in water).
  • a solvent-based adhesive composition refers to an adhesive composition containing an adhesive in an organic solvent.
  • organic solvent contained in the solvent-based adhesive composition one or more of the organic solvents (toluene, ethyl acetate, etc.) that can be used in the above-mentioned solution polymerization can be used without particular limitation.
  • the technology disclosed herein can be preferably implemented in an embodiment including an adhesive layer formed from a solvent-based adhesive composition from the viewpoint of adhesive properties and the like.
  • the adhesive layer disclosed herein can be formed by a conventionally known method.
  • a method can be adopted in which a pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive composition to a surface having peelability (peelability surface) or a non-peelability surface and drying it.
  • a method directly method of forming an adhesive layer by directly applying (typically coating) an adhesive composition to the base material and drying is adopted.
  • a method transfer method in which an adhesive composition is applied to a surface that has releasability (release surface) and dried to form an adhesive layer on the surface, and the adhesive layer is transferred to a base material. may be adopted.
  • the transfer method is preferred.
  • the release surface the surface of a release liner, the back surface of a release-treated base material, etc. can be used.
  • the adhesive layer disclosed herein is typically formed continuously, it is not limited to this form, and may be formed, for example, in a regular or random pattern such as dots or stripes. It may also be a formed adhesive layer.
  • the adhesive composition can be applied using a conventionally known coater such as a gravure roll coater, die coater, or bar coater. Alternatively, the adhesive composition may be applied by impregnation, curtain coating, or the like. From the viewpoint of promoting crosslinking reaction, improving production efficiency, etc., it is preferable to dry the adhesive composition under heating.
  • the drying temperature can be, for example, about 40 to 150°C, and usually preferably about 60 to 130°C.
  • aging may be performed for the purpose of adjusting component migration within the pressure-sensitive adhesive layer, progressing the crosslinking reaction, alleviating distortion that may exist within the pressure-sensitive adhesive layer, and the like.
  • the thickness of the adhesive layer is not particularly limited, and a configuration having an adhesive layer having an appropriate thickness in the range of, for example, 0.1 to 500 ⁇ m may be adopted depending on the use and purpose of use.
  • the thickness of the adhesive layer is usually approximately 100 ⁇ m or less, preferably approximately 70 ⁇ m or less, more preferably approximately 60 ⁇ m or less, More preferably, it is approximately 50 ⁇ m or less.
  • the thickness of the adhesive layer can be approximately 35 ⁇ m or less, and may be approximately 30 ⁇ m or less, for example.
  • An adhesive layer with a limited thickness can meet the demands for thinning and weight reduction.
  • the adhesive layer can be With this configuration, sufficient impact resistance and adhesive strength can be achieved.
  • the lower limit of the thickness of the adhesive layer is suitably about 0.5 ⁇ m or more, from the viewpoint of adhesion to the adherend, it may be about 1 ⁇ m or more, and it may be about 3 ⁇ m or more.
  • it is approximately 10 ⁇ m or more, more preferably approximately 12 ⁇ m or more (eg greater than 12 ⁇ m), still more preferably approximately 15 ⁇ m or more, and may for example be approximately 18 ⁇ m or more.
  • the thickness of the adhesive layer is greater than 20 ⁇ m, may be greater than or equal to 24 ⁇ m, and may be greater than or equal to 27 ⁇ m.
  • the pressure-sensitive adhesive sheet disclosed herein may be a pressure-sensitive adhesive sheet having pressure-sensitive adhesive layers having the above-mentioned thickness on both sides of a base material.
  • the first adhesive layer and the second adhesive layer have the same thickness. They may have different thicknesses.
  • the adhesive layer may include a biomass-derived material, and the biomass carbon ratio may be greater than or equal to a predetermined value.
  • the biomass carbon ratio of the adhesive layer is, for example, 1% or more, and may be 10% or more, preferably 30% or more, and more preferably 50% or more.
  • a high biomass carbon ratio in the adhesive means that less fossil resource-based materials, such as petroleum, are used. From this point of view, the higher the biomass carbon ratio of the adhesive, the more preferable.
  • the biomass carbon ratio of the adhesive layer may be 55% or more, 60% or more, 70% or more, 75% or more, 80% or more, or more than 80%. good.
  • the upper limit of the biomass carbon ratio is 100% by definition, and may be 99% or less, and from the viewpoint of material availability, it may be 95% or less, or 90% or less. In some embodiments, from the viewpoint of facilitating good adhesive performance, the biomass carbon ratio of the adhesive layer may be, for example, 90% or less, 85% or less, or 80% or less.
  • the adhesive sheet disclosed herein is in the form of a single-sided adhesive type or double-sided adhesive type adhesive sheet with a base material
  • the base material that supports (backs) the adhesive layer may be a resin film, paper, cloth, or rubber. Sheets, foam sheets, metal foils, composites thereof, etc. can be used. Examples of paper include Japanese paper, kraft paper, glassine paper, high quality paper, synthetic paper, top coated paper, and the like. Examples of the fabric include woven fabrics and nonwoven fabrics made of various fibrous substances alone or in combination.
  • Examples of the above-mentioned fibrous materials include cotton, staple fiber, Manila hemp, pulp, rayon, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, and polyolefin fiber.
  • Examples of rubber sheets include natural rubber sheets, butyl rubber sheets, and the like.
  • Examples of foam sheets include foamed polyolefin sheets, foamed polyurethane sheets, foamed polychloroprene rubber sheets, and the like.
  • Examples of metal foil include aluminum foil, copper foil, and the like. Note that the base material that supports the adhesive layer is also referred to as a base material layer in the adhesive sheet.
  • the base material may be formed from a biomass-derived material or a non-biomass-derived material. From the viewpoint of producing a pressure-sensitive adhesive sheet in consideration of reducing dependence on fossil resource-based materials, biomass-derived base materials (typically resin films) are preferably used.
  • the base material may be formed using a recyclable material or a recycled material (also referred to as recycled material).
  • a resin film is preferably used. Resin films (for example, polyester films such as PET films) can be recycled, so whether or not they are made from plant-based materials, reusing the used resin film allows for sustainable reproduction. It is possible to reduce the environmental burden.
  • a recyclable resin film or a recycled resin film is also referred to as a recycled film.
  • the recycled material (for example, recycled film) may be formed from a biomass-derived material or a non-biomass-derived material.
  • the base material constituting the base material-attached pressure-sensitive adhesive sheet one containing a resin film as a base film can be preferably used.
  • the base film is typically an independently shape-maintainable (independent) member.
  • the base material in the technology disclosed herein may be substantially composed of such a base film.
  • the base material may include an auxiliary layer in addition to the base film. Examples of the auxiliary layer include a colored layer, a reflective layer, an undercoat layer, an antistatic layer, etc. provided on the surface of the base film.
  • the resin film is a film whose main component is a resin material (for example, a component contained in the resin film in an amount exceeding 50% by weight).
  • resin films include polyolefin resin films such as polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymers; polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), etc.
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PEN polyethylene naphthalate
  • polyester resin film vinyl chloride resin film; vinyl acetate resin film; polyimide resin film; polyamide resin film; fluororesin film; cellophane; and the like.
  • the resin film may be a rubber film such as a natural rubber film or a butyl rubber film. Among these, polyester films are preferred from the viewpoint of handling and processability, and among these, PET films are particularly preferred.
  • resin film is typically a non-porous sheet, and is a concept that is distinguished from so-called non-woven fabrics and woven fabrics (in other words, a concept excluding non-woven fabrics and woven fabrics).
  • the resin film may be an unstretched film, a uniaxially stretched film, or a biaxially stretched film.
  • such resin films may be non-foamed.
  • the non-foamed resin film refers to a resin film that has not been intentionally processed to form a foam.
  • the non-foamed resin film may be a resin film with an expansion ratio of less than 1.1 times (for example, less than 1.05 times, typically less than 1.01 times).
  • the above base material may contain fillers (inorganic fillers, organic fillers, etc.), colorants, dispersants (surfactants, etc.), anti-aging agents, antioxidants, ultraviolet rays, etc., as necessary.
  • Various additives such as an absorbent, an antistatic agent, a lubricant, and a plasticizer may be blended.
  • the blending ratio of various additives is about less than 30% by weight (for example, less than 20% by weight, typically less than 10% by weight).
  • the base material may have a single layer structure, or may have a multilayer structure of two layers, three layers, or more. From the viewpoint of shape stability, the base material preferably has a single-layer structure. In the case of a multilayer structure, at least one layer (preferably all layers) is preferably a layer having a continuous structure of the above resin (for example, polyester resin).
  • the method for manufacturing the base material is not particularly limited, and any conventionally known method may be appropriately adopted. For example, conventionally known general film forming methods such as extrusion molding, inflation molding, T-die casting molding, and calender roll molding can be appropriately employed.
  • the surface of the base material may be subjected to conventionally known surface treatments such as corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and application of an undercoat.
  • Such surface treatment may be a treatment for improving the adhesion between the base material and the adhesive layer, in other words, the ability of the adhesive layer to anchor to the base material.
  • the back surface of the base material may be subjected to a peeling treatment as necessary.
  • the peeling treatment is performed by applying a general silicone-based, long-chain alkyl-based, or fluorine-based peeling agent to a thin film, typically about 0.01 ⁇ m to 1 ⁇ m (for example, 0.01 ⁇ m to 0.1 ⁇ m). It can be a process to add. By performing such a peeling treatment, effects such as facilitating the unwinding of a roll of the adhesive sheet can be obtained.
  • the thickness of the base material is not particularly limited. From the viewpoint of preventing the pressure-sensitive adhesive sheet from becoming too thick, the thickness of the base material can be, for example, approximately 200 ⁇ m or less, preferably approximately 150 ⁇ m or less, and more preferably approximately 100 ⁇ m or less.
  • the thickness of the base material may be approximately 70 ⁇ m or less, approximately 50 ⁇ m or less, or approximately 30 ⁇ m or less (for example, approximately 25 ⁇ m or less) depending on the purpose and manner of use of the adhesive sheet. In some embodiments, the thickness of the substrate can be about 20 ⁇ m or less, about 15 ⁇ m or less, about 10 ⁇ m or less (eg, about 5 ⁇ m or less).
  • the thickness of the adhesive layer can be increased even if the total thickness of the adhesive sheet is the same. This can be advantageous from the viewpoint of improving adhesion to adherends and base materials.
  • the lower limit of the base material is not particularly limited. From the viewpoint of handleability and processability of the pressure-sensitive adhesive sheet, the thickness of the base material is usually about 0.5 ⁇ m or more (for example, 1 ⁇ m or more), preferably about 2 ⁇ m or more, for example about 6 ⁇ m or more. In some embodiments, the thickness of the substrate can be about 15 ⁇ m or more, and can be about 25 ⁇ m or more.
  • a foam substrate is used as the substrate.
  • the foam base material disclosed herein is a base material that includes a portion having cells (cell structure), and typically includes at least one layer of layered foam (foam layer). be.
  • the foam base material may be a base material composed of one or more foam layers.
  • the foam base material may be, for example, a base material substantially composed only of one or more foam layers.
  • one suitable example of the foam base material in the technology disclosed herein is a foam base material consisting of a single foam layer.
  • the thickness of the foam base material is not particularly limited, and can be appropriately set depending on the strength and flexibility of the adhesive sheet, the purpose of use, etc. From the viewpoint of thinning, the thickness of the foam base material is usually 1 mm or less, suitably 0.70 mm or less, preferably 0.40 mm or less, and more preferably 0.30 mm or less. The technology disclosed herein is preferably implemented in an embodiment in which the thickness of the foam base material is 0.25 mm or less (typically 0.18 mm or less, for example 0.16 mm or less) from the viewpoint of processability etc. obtain.
  • the thickness of the foam base material is usually 0.04 mm or more, suitably 0.05 mm or more, preferably 0.06 mm or more, and 0.07 mm or more. More preferably (for example, 0.08 mm or more).
  • the technology disclosed herein is preferably implemented in an embodiment in which the thickness of the foam base material is 0.10 mm or more (typically more than 0.10 mm, preferably 0.12 mm or more, for example 0.13 mm or more). obtain. Increasing the thickness of the foam substrate tends to improve impact resistance.
  • the density (referring to apparent density; hereinafter the same applies unless otherwise specified) of the foam base material is not particularly limited, and may be, for example, 0.1 to 0.9 g/cm 3 .
  • the density of the foam base material is suitably 0.8 g/cm 3 or less, preferably 0.7 g/cm 3 or less (for example, 0.6 g/cm 3 or less).
  • the density of the foam substrate may be less than 0.5 g/cm 3 , and may be less than 0.4 g/cm 3 (eg, 0.5 g/cm 3 or less).
  • the density of the foam base material is preferably 0.12 g/cm 3 or more, more preferably 0.15 g/cm 3 or more, and 0.2 g/cm 3 or more (for example, 0.3 g/cm 3 or more). /cm 3 or more) is more preferable.
  • the density of the foam substrate can be 0.4 g/cm or more, 0.5 g/cm 3 or more (e.g., greater than 0.5 g/cm 3 ), or even 0.5 g/cm 3 or more (e.g., greater than 0.5 g/cm 3 ), It may be .55 g/cm 3 or more.
  • the density (apparent density) of the foam base material can be measured in accordance with JIS K 6767.
  • the average cell diameter of the foam base material is not particularly limited, but from the viewpoint of stress distribution, it is preferably 300 ⁇ m or less, more preferably 200 ⁇ m or less, and even more preferably 150 ⁇ m or less.
  • the lower limit of the average cell diameter is not particularly limited, but from the viewpoint of step followability, it is usually suitable to be 10 ⁇ m or more, preferably 20 ⁇ m or more, more preferably 30 ⁇ m or more, and even more preferably 40 ⁇ m or more (for example, 50 ⁇ m or more).
  • the average cell diameter may be 55 ⁇ m or more, or 60 ⁇ m or more.
  • the average cell diameter here refers to the average cell diameter in terms of a perfect sphere, which is obtained by observing the cross section of the foam base material with an electron microscope.
  • the cell structure of the foam constituting the foam base material disclosed herein is not particularly limited.
  • the cell structure may be any of an open cell structure, a closed cell structure, and a semi-open and semi-closed cell structure. From the viewpoint of shock absorption, closed cell structures and semi-open and semi-closed cell structures are preferred.
  • the 25% compressive strength C25 of the foam base material is not particularly limited, and may be, for example, 20 kPa or more (typically 30 kPa or more, and even 40 kPa or more).
  • C25 is usually suitably 250 kPa or more, preferably 300 kPa or more (for example, 400 kPa or more).
  • a pressure-sensitive adhesive sheet including such a foam base material can exhibit good durability against impacts such as dropping. For example, tearing of the adhesive sheet due to impact can be better prevented.
  • the upper limit of C25 is not particularly limited, it is usually suitable to be 1300 kPa or less (for example, 1200 kPa or less).
  • C 25 may be 1000 kPa or less, 800 kPa or less, even 600 kPa or less (eg, 500 kPa or less), or 360 kPa or less.
  • the C 25 of the foam substrate may be between 20 kPa and 200 kPa (typically between 30 kPa and 150 kPa, such as between 40 kPa and 120 kPa).
  • a pressure-sensitive adhesive sheet including such a foam base material can have excellent cushioning properties. For example, if the foam base material absorbs the impact of a fall, peeling of the adhesive sheet can be better prevented.
  • the 25% compressive strength C25 of the foam base material is determined by cutting the foam base material into 30 mm squares, stacking them to a thickness of about 2 mm, and sandwiching the measurement sample between a pair of flat plates. It refers to the load when compressed by a thickness corresponding to 25% of the thickness (load at a compression rate of 25%). That is, it refers to the load when the measurement sample is compressed to a thickness corresponding to 75% of its original thickness.
  • the compressive strength is measured in accordance with JIS K 6767. The specific measurement procedure is to set the measurement sample at the center of the pair of flat plates, compress the plate continuously to a predetermined compression rate by narrowing the gap between the plates, and then stop the flat plates for 10 seconds. Measure the load after the elapsed time.
  • the compressive strength of the foam base material can be controlled by, for example, the degree of crosslinking and density of the material constituting the foam base material, the size and shape of the cells, and the like.
  • the tensile elongation of the foam base material is not particularly limited.
  • a foam base material having a tensile elongation in the machine direction (MD) of 200% to 800% (more preferably 400% to 600%) can be suitably employed.
  • a foam base material having a tensile elongation in the width direction (TD) of 50% to 800% (more preferably 200% to 500%) is preferable.
  • the elongation of the foam base material is measured in accordance with JIS K 6767.
  • the elongation of the foam base material can be controlled, for example, by the degree of crosslinking, apparent density (expansion ratio), and the like.
  • the tensile strength (tensile strength) of the foam base material is not particularly limited.
  • a foam base material having a tensile strength in the machine direction (MD) of 5 MPa to 35 MPa (preferably 10 MPa to 30 MPa) can be suitably employed.
  • a foam base material having a tensile strength in the width direction (TD) of 1 MPa to 25 MPa (more preferably 5 MPa to 20 MPa) is preferable.
  • the tensile strength of the foam base material is measured in accordance with JIS K 6767.
  • the tensile strength of the foam base material can be controlled, for example, by the degree of crosslinking, apparent density (expansion ratio), and the like.
  • the material of the foam base material is not particularly limited.
  • Foam substrates comprising a foam layer formed of a foam of plastic material (plastic foam) are usually preferred.
  • the plastic material (which includes rubber materials) for forming the plastic foam is not particularly limited, and can be appropriately selected from known plastic materials. The plastic materials can be used alone or in an appropriate combination of two or more.
  • plastic foams include polyolefin resin foams such as PE foams and PP foams; polyester resin foams such as PET foams, PEN foams, and PBT foams; Polyvinyl chloride resin foam such as polyvinyl chloride foam; vinyl acetate resin foam; polyphenylene sulfide resin foam; aliphatic polyamide (nylon) resin foam, wholly aromatic polyamide (aramid) Amide resin foams such as resin foams; polyimide resin foams; polyetheretherketone (PEEK) foams; styrene resin foams such as polystyrene foams; polyurethane resin foams, etc. Urethane resin foam; and the like.
  • a rubber resin foam such as a polychloroprene rubber foam may be used as a polychloroprene rubber foam may be used.
  • a preferred foam is exemplified by a polyolefin resin foam (hereinafter also referred to as "polyolefin foam").
  • polyolefin foam As the plastic material (ie, polyolefin resin) constituting the polyolefin foam, various known or commonly used polyolefin resins can be used without particular limitation. Examples include PE such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE), PP, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and the like.
  • PE low-density polyethylene
  • LLDPE linear low-density polyethylene
  • HDPE high-density polyethylene
  • PP ethylene-propylene copolymer
  • ethylene-vinyl acetate copolymer ethylene-vinyl acetate copolymer
  • LLDPE examples include Ziegler-Natta catalyst-based linear low-density polyethylene, metallocene-catalyzed linear low-density polyethylene, and the like. Such polyolefin resins can be used alone or in an appropriate combination of two or more.
  • a preferred example of the foam base material in the technology disclosed herein is a PE foam base material substantially composed of a PE resin foam from the viewpoint of impact resistance, waterproofness, dustproofness, etc. , a polyolefin foam base material such as a PP foam base material substantially composed of a foam of a PP resin.
  • the PE-based resin refers to a resin whose main monomer (that is, the main component among monomers) is ethylene, and includes HDPE, LDPE, LLDPE, etc., as well as ethylene-based resin with an ethylene copolymerization ratio of more than 50% by weight. It may include propylene copolymers, ethylene-vinyl acetate copolymers, and the like.
  • PP-based resin refers to a resin whose main monomer is propylene.
  • a PE foam base material can be preferably employed.
  • the method for producing the plastic foam is not particularly limited, and various known methods may be employed as appropriate. For example, it can be manufactured by a method including a molding step, a crosslinking step, and a foaming step of the above plastic material or the above plastic foam. Moreover, a stretching step may be included as necessary.
  • methods for crosslinking the plastic foam include a chemical crosslinking method using an organic peroxide or the like, an ionizing radiation crosslinking method involving irradiation with ionizing radiation, and these methods may be used in combination. Examples of the ionizing radiation include electron beams, ⁇ rays, ⁇ rays, ⁇ rays, and the like.
  • the dose of ionizing radiation is not particularly limited, and can be set to an appropriate dose in consideration of the target physical properties (for example, degree of crosslinking) of the foam base material.
  • the foam base material may contain fillers (inorganic fillers, organic fillers, etc.), anti-aging agents, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, plasticizers, flame retardants, Various additives such as surfactants may be blended.
  • the foam base material in the technology disclosed herein may be black or white in order to exhibit desired design properties and optical properties (e.g., light shielding properties, light reflection properties, etc.) in a pressure-sensitive adhesive sheet including the foam base material. It may be colored as such.
  • desired design properties and optical properties e.g., light shielding properties, light reflection properties, etc.
  • It may be colored as such.
  • one kind of known organic or inorganic coloring agent can be used alone or two or more kinds can be used in an appropriate combination.
  • the surface of the foam base material may be subjected to an appropriate surface treatment, if necessary.
  • This surface treatment can be, for example, a chemical or physical treatment to increase adhesion to adjacent materials (eg, adhesive layer).
  • Examples of such surface treatments include corona discharge treatment, chromic acid treatment, ozone exposure, flame exposure, ultraviolet irradiation treatment, plasma treatment, application of a primer, and the like.
  • a release liner can be used during formation of the adhesive layer, production of the adhesive sheet, storage of the adhesive sheet before use, distribution, shape processing, etc.
  • the release liner is not particularly limited, and for example, a release liner having a release treatment layer on the surface of a liner base material such as a resin film or paper, a release liner made of a fluorine-based polymer (polytetrafluoroethylene, etc.), etc. may be used. be able to.
  • the release treatment layer may be formed by surface-treating the liner base material with a release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide release agent.
  • a release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide release agent.
  • the liner base material like the base material of the above-mentioned adhesive sheet, one formed using a biomass-derived material or a recycled material (recycled film, etc.) can be preferably used.
  • the total thickness of the adhesive sheet disclosed herein (which includes an adhesive layer and may further include a base layer, but does not include a release liner) is not particularly limited.
  • the total thickness of the adhesive sheet is, for example, approximately 1 mm or less, may be approximately 500 ⁇ m or less, and may be approximately 300 ⁇ m or less, and from the viewpoint of thinning, approximately 200 ⁇ m or less is appropriate, and approximately 150 ⁇ m or less. (For example, approximately 100 ⁇ m or less).
  • the thickness of the pressure-sensitive adhesive sheet can be approximately 50 ⁇ m or less, for example, approximately 35 ⁇ m or less.
  • the lower limit of the thickness of the adhesive sheet is, for example, 0.1 ⁇ m or more (for example, 0.5 ⁇ m or more), suitably about 3 ⁇ m or more, preferably about 10 ⁇ m or more, more preferably about 15 ⁇ m or more, It may be about 50 ⁇ m or more, or about 100 ⁇ m or more.
  • a pressure-sensitive adhesive sheet having a thickness of a predetermined value or more tends to have good adhesion to an adherend and also tends to have excellent handling properties.
  • the thickness of the adhesive layer becomes the total thickness of the adhesive sheet.
  • the adhesive sheet has a 180 degree peel strength against a stainless steel plate (adhesion strength against SUS) of about 15 N/25 mm or more (for example, 17 N/25 mm or more).
  • a pressure-sensitive adhesive sheet exhibiting such adhesive strength to SUS can exhibit excellent adhesive strength.
  • the adhesive strength to SUS is more preferably about 20 N/25 mm or more, still more preferably about 23 N/25 mm or more, particularly preferably 25 N/25 mm or more (for example, 26 N/25 mm or more).
  • the upper limit of the adhesive strength to SUS is not particularly limited, but from the viewpoint of coexistence with other adhesive properties such as repulsion resistance, it may usually be about 50 N/25 mm or less, for example.
  • the adhesive strength to SUS is measured using a SUS plate as an adherend under the conditions of a tensile speed of 300 mm/min and a peel angle of 180 degrees in a measurement environment of 23° C. and 50% RH. More specifically, it is measured by the method described in Examples below.
  • the pressure-sensitive adhesive sheet disclosed herein preferably has a floating height of 2.0 mm or less at the end of the test in a repulsion resistance evaluation test conducted by the method described below.
  • a pressure-sensitive adhesive sheet that satisfies the above characteristics has particularly excellent repulsion resistance against a peeling load consisting essentially only in the thickness direction (Z-axis direction) of the pressure-sensitive adhesive sheet, and has a sustained resistance in that direction. Particularly resistant to peeling under peeling loads. It also exhibits stable repulsion resistance even when adhesive sheets attached to adherends (e.g., mobile electronic devices and their component modules) are exposed to high temperature and high humidity conditions during storage. It is possible.
  • adherends e.g., mobile electronic devices and their component modules
  • the floating height is suitably 1.5 mm or less, preferably 1.0 mm or less, more preferably 0.7 mm or less, even more preferably 0.5 mm or less, particularly preferably 0.4 mm or less.
  • the above-mentioned floating height is a height that includes the thickness of the adhesive sheet (30 ⁇ m in the examples described later).
  • a polyethylene terephthalate (PET) film having a length of 70 mm, a width of 10 mm, and a thickness of 75 ⁇ m is fixed at one longitudinal end of the PET film to the lower surface of a polycarbonate plate having a length of 30 mm, a width of 10 mm, and a thickness of 2 mm.
  • the PET film is bent along the longitudinal direction, and the other end of the bent PET film in the longitudinal direction is fixed to the upper surface of the polycarbonate plate using an adhesive sheet with an adhesion area of 3 mm x 10 mm. This state is maintained at 65° C., 90% RH, and 72 hours (repulsion resistance evaluation test).
  • the floating height [mm] of the adhesive sheet from the polycarbonate plate is measured. More specifically, the above-mentioned repulsion resistance evaluation test is carried out by the method described in the Z-axis direction repulsion resistance test in Examples described below.
  • the adhesive sheet disclosed herein preferably has an impact adhesive strength of 0.3 J/cm 2 or more in an impact test conducted in accordance with JIS K6855.
  • a pressure-sensitive adhesive sheet that satisfies this property can serve as a bonding means with excellent durability against impact in the shear direction. Therefore, for example, it can be preferably used as a member fixing means in a portable electronic device that is expected to be exposed to shocks due to drops or collisions.
  • 0.35 J/cm 2 or more (more preferably 0.40 J/cm 2 or more, still more preferably 0.45 J/cm 2 or more, particularly preferably 0.50 J/cm 2 or more)
  • a pressure-sensitive adhesive sheet can be provided that exhibits an impact adhesive strength of .
  • the upper limit of the impact adhesive strength is not particularly limited, and may be, for example, 3.00 J/cm 2 or less. From the viewpoint of easily achieving both repulsion resistance and repulsion resistance at a higher level, the impact adhesive strength may be, for example, 1.00 J/cm 2 or less, 0.80 J/cm 2 or less, or 0.60 J. / cm2 or less. More specifically, the above-mentioned impact resistance test is carried out by the method described in the impact resistance test of Examples below.
  • the adhesive sheet may include a biomass-derived material, and the biomass carbon ratio may be greater than or equal to a predetermined value.
  • the biomass carbon ratio of the adhesive sheet is, for example, 1% or more, and may be 10% or more, preferably 30% or more, and more preferably 50% or more.
  • a high biomass carbon ratio in the adhesive sheet means that less fossil resource-based materials, such as petroleum, are used. From this point of view, the higher the biomass carbon ratio of the pressure-sensitive adhesive sheet, the more preferable it is.
  • the biomass carbon ratio of the adhesive sheet may be 55% or more, 60% or more, 70% or more, 75% or more, 80% or more, or more than 80%. .
  • the upper limit of the biomass carbon ratio is 100% by definition, and may be 99% or less, and from the viewpoint of material availability, it may be 95% or less, or 90% or less. In some embodiments, from the viewpoint of facilitating good adhesive performance, the biomass carbon ratio of the adhesive sheet may be, for example, 90% or less, 85% or less, or 80% or less.
  • the use of the pressure-sensitive adhesive sheet disclosed herein is not particularly limited, and can be used for various purposes.
  • the pressure-sensitive adhesive sheet disclosed herein is capable of achieving both repulsion resistance and impact resistance, and is therefore suitable for adhesively fixing members in applications where high repulsion resistance and impact resistance may be required.
  • it can be preferably used for fixing members in various types of portable equipment.
  • Non-limiting examples of the above-mentioned portable electronic devices include mobile phones, smartphones, tablet computers, notebook computers, and various wearable devices (e.g., wrist-wear type that is worn on the wrist like a wristwatch, and Modular type that is attached to a part of the body, eyewear type that includes glasses type (monocular type and binocular type, including head-mounted type), clothing type that is attached to shirts, socks, hats, etc. in the form of accessories, and earphones. digital cameras, digital video cameras, audio equipment (portable music players, IC recorders, etc.), calculators (calculators, etc.), portable game devices, electronic dictionaries, electronic notebooks, electronic books, and in-vehicle devices.
  • wearable devices e.g., wrist-wear type that is worn on the wrist like a wristwatch, and Modular type that is attached to a part of the body
  • eyewear type that includes glasses type (monocular type and binocular type, including head-mounted type)
  • clothing type that is attached
  • portable does not mean that it is sufficient to simply be able to carry it; it also means that it has a level of portability that allows an individual (standard adult) to carry it relatively easily. shall mean.
  • the adhesive sheet (typically a double-sided adhesive sheet) disclosed herein is in the form of a bonding material processed into various external shapes and can be used for fixing members constituting the portable electronic device as described above. Among these, it can be preferably used for portable electronic devices having a liquid crystal display device. For example, it is an electronic device (typically a portable electronic device such as a smartphone) that has a display section such as a touch panel display (which can be a display section of a liquid crystal display device), and is used to increase the screen size.
  • the adhesive sheet disclosed herein is preferably used for fixing an elastic adherend in a device in which an elastic member such as FPC is folded and accommodated in an internal space.
  • the pressure-sensitive adhesive sheet disclosed herein By using the pressure-sensitive adhesive sheet disclosed herein, it is possible to stably fix an elastic adherend in a bent state, and to maintain the fixed state continuously. As a result, the elastic member accommodated in a bent state in the limited internal space of the portable electronic device can be accurately positioned and held in a stable fixed state by the adhesive sheet disclosed herein.
  • materials disposed inside the above-mentioned portable electronic devices include polar and rigid materials such as polycarbonate and polyimide.
  • the adhesive sheet disclosed herein can preferably exhibit repulsion resistance against a sustained load in the Z-axis direction.
  • the adhesive sheet disclosed herein is preferably used in a portable electronic device for fixing a member such as a cover glass having a three-dimensional shape (typically, a curved shape) that constitutes the portable electronic device.
  • a member such as a cover glass having a three-dimensional shape (typically, a curved shape) that constitutes the portable electronic device.
  • Adhesive sheets used for fixing members having such three-dimensional surface shapes tend to be subjected to a relatively large sustained load in the Z-axis direction. By using the adhesive sheet disclosed herein, even a member having a three-dimensional shape as described above can be stably fixed.
  • Examples of means for increasing circuit integration include double-sided FPC and multilayer FPC, but both increase the rigidity of the FPC, and the Z-axis as evaluated by the Z-axis repulsion test described below. It is expected that improved repulsion resistance against sustained loads in the axial direction will become a required characteristic.
  • the pressure-sensitive adhesive sheet according to a preferred embodiment of the technology disclosed herein may exhibit excellent repulsion resistance under harsh high temperature and high humidity conditions (strong repulsion conditions) as in the Z-axis repulsion resistance test described below. Therefore, it is more suitable for the above-mentioned next-generation touch-panel display-equipped electronic devices (typically, touch-panel display-equipped portable electronic devices such as smartphones), and can be preferably used.
  • the adhesive sheet is preferably used, for example, in electronic devices that include various light sources such as LEDs (light emitting diodes) and light emitting elements such as self-luminous organic EL.
  • electronic equipment typically portable electronic equipment
  • organic EL display device or a liquid crystal display device.
  • FIG. 4 is an example schematically showing a portable electronic device (smartphone) using the adhesive sheet disclosed herein.
  • a battery (heat generating element) 540 is built inside the casing 520 of the portable electronic device 500.
  • the portable electronic device 500 is configured to include an adhesive sheet 550.
  • the adhesive sheet 550 has the form of a double-sided adhesive sheet (double-sided adhesive sheet) that fixes members constituting the portable electronic device 500.
  • the portable electronic device 500 includes a touch panel 570 whose display section also functions as an input section.
  • the adhesive sheet disclosed herein is preferably used as a component (member joining means) of the above-mentioned portable electronic devices.
  • the adhesive sheet disclosed herein may have an adhesive layer containing an acrylic polymer with a high biomass carbon ratio in some embodiments, conventional general acrylic adhesives (i.e. By being used as a substitute for acrylic adhesives in various applications where acrylic adhesives (acrylic adhesives with a low biomass carbon ratio) are used, it can contribute to reducing dependence on fossil resource-based materials.
  • the adhesive sheet disclosed herein can be preferably used as an adhesive sheet with reduced dependence on fossil resource materials.
  • a portable electronic device An adhesive sheet is bonded to the member constituting the portable electronic device,
  • the adhesive sheet has an adhesive layer containing an acrylic polymer,
  • the acrylic polymer is a polymer of monomer components containing heptyl acrylate,
  • the adhesive layer has a storage modulus G' of 20,000 Pa or more at 65°C, and a tan ⁇ of 0.3 or more at -20°C, where the tan ⁇ is the adhesive layer.
  • the ratio (G''/G') of the loss elastic modulus G'' to the storage elastic modulus G' of a portable electronic device is the ratio (G''/G') of the loss elastic modulus G'' to the storage elastic modulus G' of a portable electronic device.
  • the portable electronic device according to [1] above, wherein the acrylic polymer has a weight average molecular weight of 700,000 or more.
  • the glass transition temperature of the adhesive layer is within the range of -15°C to 15°C, where the glass transition temperature of the adhesive layer is determined from the peak temperature of tan ⁇ in dynamic viscoelasticity measurement.
  • the portable electronic device according to [1] or [2] above, which has a glass transition temperature.
  • the adhesive layer contains at least one selected from a rosin-based tackifying resin and a terpene-based tackifying resin.
  • the content of the tackifying resin in the adhesive layer is 70 parts by weight or less based on 100 parts by weight of the acrylic polymer. device.
  • the adhesive layer further contains an acrylic oligomer.
  • the adhesive composition for forming the adhesive layer includes at least one selected from an isocyanate crosslinking agent and an epoxy crosslinking agent, according to any one of [1] to [7] above.
  • portable electronic devices [9] The portable electronic device according to any one of [1] to [8] above, wherein the adhesive sheet has a 180 degree peel strength of 20 N/25 mm or more against a stainless steel plate.
  • the acrylic polymer is a polymer of monomer components containing heptyl acrylate,
  • the adhesive layer has a storage modulus G' of 20,000 Pa or more at 65°C, and a tan ⁇ of 0.3 or more at -20°C, where the tan ⁇ is the adhesive layer.
  • the glass transition temperature of the adhesive layer is within the range of -15°C to 15°C, where the glass transition temperature of the adhesive layer is determined from the peak temperature of tan ⁇ in dynamic viscoelasticity measurement.
  • the pressure-sensitive adhesive layer contains at least one selected from rosin-based tackifying resins and terpene-based tackifying resins.
  • the adhesive composition for forming the adhesive layer includes at least one selected from an isocyanate crosslinking agent and an epoxy crosslinking agent, according to any one of [11] to [17] above. adhesive sheet.
  • n-HpA is a compound having a biomass-derived heptyl group at the ester end, which was synthesized using biomass-derived heptyl alcohol.
  • terpene phenol A (trade name "YS Polystar T-115", manufactured by Yasuhara Chemical Co., Ltd.) was added as a tackifying resin to 100 parts of the acrylic polymer contained in the solution.
  • the obtained adhesive composition was applied to the release surface of a polyester release film (trade name “Diafoil MRF”, manufactured by Mitsubishi Chemical Corporation) with a thickness of 38 ⁇ m, and dried at 100° C. for 2 minutes to form a film with a thickness of 30 ⁇ m.
  • An adhesive layer was formed.
  • a release surface of a 25 ⁇ m thick polyester release film (trade name “Diafoil MRF”, 25 ⁇ m thick, manufactured by Mitsubishi Chemical Corporation) was attached to this adhesive layer. In this way, a substrate-less double-sided pressure-sensitive adhesive sheet having a thickness of 30 ⁇ m and having both sides protected by the two polyester release films was obtained.
  • Examples 2 to 6 and Comparative Examples 1 to 4> Basically the same method as in Example 1 except that the monomer composition of the acrylic polymer, Mw, the type and amount of the tackifying resin, the amount of the acrylic oligomer, and the type and amount of the crosslinking agent were changed as shown in Table 1.
  • a pressure-sensitive adhesive composition according to each example was prepared, and using the obtained pressure-sensitive adhesive composition, a substrate-less double-sided adhesive sheet (thickness: 30 ⁇ m) according to each example was prepared in the same manner as in Example 1. ) was created.
  • the Mw of the acrylic polymer was adjusted by adjusting the concentration of monomer components during polymerization.
  • Terpene phenol B is a product name "YS Polyster S-145" manufactured by Yasuhara Chemical Co., Ltd. (a terpene phenol resin with a softening point of approximately 145°C and a hydroxyl value of 70 to 110 mgKOH/g), and the rosin ester is manufactured by Arakawa Chemical Co., Ltd.
  • the product name is "Pensel D125” (polymerized rosin ester with a softening point of 125° C.
  • the acrylic oligomer one prepared by the following method was used. Specifically, in a reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas introduction tube, a reflux condenser, and a dropping funnel, 95 parts of cyclohexyl methacrylate (CHMA) and 5 parts of AA, and 10 parts of AIBN as a polymerization initiator, After charging ethyl acetate as a polymerization solvent and stirring in a nitrogen stream for 1 hour to remove oxygen from the polymerization system, the temperature was raised to 85°C and reacted for 5 hours to form an acrylic oligomer with a solid content concentration of 50%. Obtained. The Mw of the obtained acrylic oligomer was 3,600.
  • ⁇ Evaluation method> [Adhesive strength to SUS] Under a measurement environment of 23°C and 50% RH, one adhesive side of an adhesive sheet (double-sided adhesive sheet) was lined with a PET film with a thickness of 50 ⁇ m, and cut into a size of 25 mm in width and 100 mm in length. A measurement sample was prepared. In an environment of 23° C. and 50% RH, the other adhesive surface of the measurement sample was pressed onto the surface of a stainless steel plate (SUS304BA plate) that had been cleaned with ethyl acetate by making one reciprocation with a 2 kg roller.
  • SUS304BA plate stainless steel plate
  • the peel strength (relative to SUS Adhesive force) [N/25 mm] was measured.
  • the universal tensile compression tester used is Minebea's "Tensile Compression Tester, TG-1kN" or its equivalent. Note that when performing the above peel strength measurement on a single-sided adhesive sheet, backing with a PET film is not necessary.
  • the base material thickness is thin (for example, when the base material thickness is 25 ⁇ m or less), it may be lined with a PET film.
  • a polycarbonate (PC) plate 50 with a length of 30 mm, a width of 10 mm, and a thickness of 2 mm, and a PET film 60 with a length of 70 mm, a width of 10 mm, and a thickness of 75 ⁇ m are prepared, The PC board 50 and the PET film 60 were stacked so that one end in the longitudinal direction was aligned, and the PC board 50 and the PET film 60 were fixed with the remaining part of the PET film 60 protruding from the other end of the PC board 50.
  • a commercially available double-sided adhesive tape manufactured by Nitto Denko Corporation, "No.
  • a pressure-sensitive adhesive sheet sample piece 70 was prepared by cutting the pressure-sensitive adhesive sheet according to each example in which both adhesive surfaces were protected with two release liners into a size of 3 mm in width and 10 mm in length. Place the surface of the PC board 50 opposite to the fixed surface of the PET film on the upper side, peel off one release liner from the adhesive sheet sample piece 70, and separate the width direction of the PC board 50 and the longitudinal direction of the adhesive sheet sample piece 70. Attach the adhesive sheet sample piece 70 to the top surface of the PC board 50 so that both ends of the adhesive sheet sample piece 70 in the width direction are on a line 7 mm and 10 mm from the other end on the top surface of the PC board 50. Fixed.
  • the above fixing was performed by moving a 2 kg roller back and forth once on the upper surface of the adhesive sheet sample piece 70 protected by the other release liner.
  • the other release liner of the adhesive sheet sample piece 70 pasted on the PC board 50 is peeled off, and the PC board 50 is removed as shown in FIG. 5(b).
  • the protruding portion (length 40 mm) of the PET film 60 fixed on the PC board 50 is folded back toward the PC board 50 side, and the adhesive sheet sample piece 70 and the other end (free end) of the PET film 60 are aligned.
  • the other end of the bent PET film 60 is fixed to the upper surface of the PC board 50 via the adhesive sheet sample piece 70 by moving a 0.1 kg roller back and forth once from above the PET film 60, and then heated at 65°C and 90%. Exposure to RH environment. After being exposed to the same environment for 72 hours, it was confirmed whether the adhesion between the adhesive sheet sample piece 70 and the PET film 60 was maintained, and if the PET film 60 was peeled off as shown in FIG. It was determined that the film had peeled off. When the PET film 60 was held, the floating height [mm] of the PET film 60 from the adhesive sheet sample piece 70 was measured using a microscope. Measurements were performed three times and the lowest value was recorded.
  • the floating height is a height that includes the thickness of the adhesive sheet sample piece 70.
  • the repulsion resistance against peeling load consisting essentially only in the thickness direction (Z-axis direction) of the adhesive sheet can be evaluated at a high temperature and high humidity of 65°C and 90% RH. It is possible to evaluate under the harsh conditions of , and furthermore, continuous repulsion resistance can be evaluated by performing observation over time.
  • Table 1 shows the outline and evaluation results of the pressure-sensitive adhesive sheets of each example.
  • the adhesives according to Examples 1 to 6 contain an acrylic polymer containing heptyl acrylate as a monomer component, and have a storage modulus G' at 65° C. of 20,000 Pa or more, Moreover, tan ⁇ at -20°C was 0.3 or more.
  • the pressure-sensitive adhesive sheets according to Examples 1 to 6 had impact resistance test results of 0.3 J/cm 2 or more, and Z-axis repulsion resistance test results of floating heights of 2.0 mm or less.
  • the adhesive according to Comparative Example 1 does not contain heptyl acrylate and contains an acrylic polymer containing 2EHA as a main monomer, and has a storage modulus G' at 65° C.
  • the adhesive sheets according to Comparative Examples 3 and 4 also had a storage modulus G' at 65° C. of the adhesive of less than 20,000 Pa, and were peeled off in the Z-axis repulsion test (Comparative Example 3), or The floating height in the directional repulsion resistance test was larger compared to Examples 1 to 6.
  • the adhesive according to Comparative Example 2 does not contain heptyl acrylate but contains an acrylic polymer containing BA as the main monomer, has a tan ⁇ of less than 0.3 at -20°C, and has passed the impact test. The results were lower than those in Examples 1 to 6.
  • Adhesive sheet Supporting base material 10A First side 10B Second side (back side) 21 Adhesive layer (first adhesive layer) 21A Adhesive surface (first adhesive surface) 21B Second adhesive surface 22 Adhesive layer (second adhesive layer) 22A Adhesive surface (second adhesive surface) 31, 32 Release liner 100, 200, 300 Adhesive sheet with release liner

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Adhesive Tapes (AREA)
PCT/JP2022/045738 2022-07-04 2022-12-12 粘着シート Ceased WO2024009530A1 (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
KR1020257001898A KR102807071B1 (ko) 2022-07-04 2022-12-12 점착 시트
CN202280097496.1A CN119421937B (zh) 2022-07-04 2022-12-12 粘合片

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-108023 2022-07-04
JP2022108023A JP7387824B1 (ja) 2022-07-04 2022-07-04 粘着シート

Publications (1)

Publication Number Publication Date
WO2024009530A1 true WO2024009530A1 (ja) 2024-01-11

Family

ID=88917978

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/045738 Ceased WO2024009530A1 (ja) 2022-07-04 2022-12-12 粘着シート

Country Status (4)

Country Link
JP (2) JP7387824B1 (https=)
KR (1) KR102807071B1 (https=)
CN (1) CN119421937B (https=)
WO (1) WO2024009530A1 (https=)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2026071201A1 (ja) * 2024-09-30 2026-04-02 積水化学工業株式会社 粘着テープ、及び、電子機器

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2626397A1 (de) * 2012-02-09 2013-08-14 tesa AG Haftklebebänder auf Basis biobasierter Monomere
JP2019070102A (ja) * 2017-10-06 2019-05-09 日東電工株式会社 アクリル系粘着剤組成物および粘着シート
WO2019244595A1 (ja) * 2018-06-19 2019-12-26 積水化学工業株式会社 粘着剤、粘着テープ、及び、電子機器部品又は車載部品を固定する方法
WO2020013168A1 (ja) * 2018-07-10 2020-01-16 日東電工株式会社 粘着シート
JP2020164844A (ja) * 2019-03-28 2020-10-08 積水化学工業株式会社 感圧粘着剤組成物及び粘着テープ

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3907611B2 (ja) 2003-06-23 2007-04-18 日東電工株式会社 粘着剤組成物及び粘着製品
KR20160055105A (ko) * 2013-09-10 2016-05-17 세키스이가가쿠 고교가부시키가이샤 전자 기기용 점착 시트
CN109628026B (zh) * 2017-10-06 2022-09-23 日东电工株式会社 丙烯酸类粘合剂组合物及粘合片
CN114829533B (zh) 2019-12-18 2024-11-22 积水化学工业株式会社 粘接剂、胶带、电器产品、车载部件及固定方法
CN114729249B (zh) 2019-12-18 2023-03-07 积水化学工业株式会社 粘合剂组合物、粘合带、电子设备部件或车载部件的固定方法、以及电子设备部件或车载部件的制造方法
US11802224B2 (en) 2021-03-22 2023-10-31 Sekisui Chemical Co., Ltd. Adhesive tape, method for fixing electronic device component or on-board device component, and method for producing electronic device or on-board device
JP7311695B1 (ja) * 2022-03-29 2023-07-19 日東電工株式会社 粘着シート

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2626397A1 (de) * 2012-02-09 2013-08-14 tesa AG Haftklebebänder auf Basis biobasierter Monomere
JP2019070102A (ja) * 2017-10-06 2019-05-09 日東電工株式会社 アクリル系粘着剤組成物および粘着シート
WO2019244595A1 (ja) * 2018-06-19 2019-12-26 積水化学工業株式会社 粘着剤、粘着テープ、及び、電子機器部品又は車載部品を固定する方法
WO2020013168A1 (ja) * 2018-07-10 2020-01-16 日東電工株式会社 粘着シート
JP2020164844A (ja) * 2019-03-28 2020-10-08 積水化学工業株式会社 感圧粘着剤組成物及び粘着テープ

Also Published As

Publication number Publication date
KR102807071B1 (ko) 2025-05-14
JP7387824B1 (ja) 2023-11-28
JP2024006794A (ja) 2024-01-17
KR20250017759A (ko) 2025-02-04
JP2024007572A (ja) 2024-01-18
CN119421937B (zh) 2025-12-12
CN119421937A (zh) 2025-02-11

Similar Documents

Publication Publication Date Title
JP7592764B2 (ja) 粘着シート
WO2024161910A1 (ja) 粘着シート
JP7387824B1 (ja) 粘着シート
JP7321328B1 (ja) 粘着シート
JP7311695B1 (ja) 粘着シート
JP7308342B1 (ja) 粘着シート
JP7176153B2 (ja) 粘着シート
JP7321329B1 (ja) 粘着シート
JP7681955B2 (ja) 粘着シート
JP7114685B2 (ja) 粘着シート
JP7321343B1 (ja) 両面粘着シート

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22950322

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 202280097496.1

Country of ref document: CN

ENP Entry into the national phase

Ref document number: 20257001898

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 1020257001898

Country of ref document: KR

WWP Wipo information: published in national office

Ref document number: 1020257001898

Country of ref document: KR

NENP Non-entry into the national phase

Ref country code: DE

WWP Wipo information: published in national office

Ref document number: 202280097496.1

Country of ref document: CN

122 Ep: pct application non-entry in european phase

Ref document number: 22950322

Country of ref document: EP

Kind code of ref document: A1