WO2024070311A1 - Feuille adhésive - Google Patents

Feuille adhésive Download PDF

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Publication number
WO2024070311A1
WO2024070311A1 PCT/JP2023/029750 JP2023029750W WO2024070311A1 WO 2024070311 A1 WO2024070311 A1 WO 2024070311A1 JP 2023029750 W JP2023029750 W JP 2023029750W WO 2024070311 A1 WO2024070311 A1 WO 2024070311A1
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WO
WIPO (PCT)
Prior art keywords
layer
adhesive sheet
light
substrate
white
Prior art date
Application number
PCT/JP2023/029750
Other languages
English (en)
Japanese (ja)
Inventor
快 岡原
亮祐 横川
友香 奥村
Original Assignee
日東電工株式会社
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
Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Publication of WO2024070311A1 publication Critical patent/WO2024070311A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • 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
    • C09J201/00—Adhesives based on unspecified macromolecular compounds
    • 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
    • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
    • C09J7/29—Laminated material
    • 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.
  • Adhesive sheets used in image display devices and portable electronic devices such as mobile phones, smartphones, digital cameras, liquid crystal displays (LCDs), and organic electroluminescence displays are required to have a variety of performance characteristics, including high adhesive strength.
  • adhesive sheets are required to have light-blocking properties so that light emitted by the optical semiconductor elements in the image display device does not leak out to the outside, or so that light from the outside does not enter the inside of the housing.
  • Patent Document 1 discloses an adhesive sheet having a laminated structure in which a light-shielding layer, a white or silver layer, and a colored layer are laminated in this order, and an adhesive layer as at least one surface layer, in which at least one surface has an L * (brightness) of 30 or more and a C * (chroma) of 3 or more, and the transmittance of light with a wavelength of 550 nm through the entire adhesive sheet is 0.3% or less. It is described that this adhesive sheet has sufficient light-shielding properties even when it is a thin film, and is capable of imparting excellent decorativeness to an adherend without being affected by the light-shielding layer on the surface.
  • Adhesive sheets with excellent light-blocking properties are generally black in color, but black may not be compatible with the adherend.
  • black adhesive sheet is used on an adherend that is a color other than black, such as gray, the design may be poor. Therefore, there is a demand for an adhesive sheet that has sufficient light-blocking properties and can give the adherend excellent design.
  • the present invention was conceived under these circumstances, and its purpose is to provide an adhesive sheet that has sufficient light-blocking properties and can give the adherend excellent design appeal.
  • the present invention provides a pressure-sensitive adhesive sheet having a laminated structure of a black light-shielding layer and a white colored layer,
  • the pressure-sensitive adhesive sheet is provided such that, with respect to L * indicated by the L * a * b * color system, the L * of one side of the pressure-sensitive adhesive sheet is 35 to 75, and the L * of the other side is 10 to 50 smaller than the L * of the one side.
  • the optical density of the above adhesive sheet at a wavelength of 550 nm is preferably 3.0 or more.
  • the above-mentioned adhesive sheet is preferably a double-sided adhesive sheet for use in fixing components together in electrical and electronic equipment.
  • the present invention also provides a method for producing a film comprising the double-sided pressure-sensitive adhesive sheet,
  • the double-sided pressure-sensitive adhesive sheet provides an electric/electronic device in which members are fixed to each other with both pressure-sensitive adhesive surfaces.
  • the adhesive sheet of the present invention has sufficient light-blocking properties and can provide an adherend with excellent design. Therefore, when the adherend has a color other than black, when the adhesive sheet is attached to the adherend, it has sufficient light-blocking properties and is not likely to interfere with the design of the adherend.
  • 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.
  • 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.
  • 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.
  • 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.
  • 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.
  • 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.
  • 1 is a schematic cross-sectional view of a pressure-sensitive adhesive sheet according to one embodiment of the present invention.
  • the pressure-sensitive adhesive sheet has a laminated structure of a black light-shielding layer and a white colored layer.
  • the white colored layer may be referred to as a "white layer.”
  • the adhesive sheet includes at least an adhesive layer.
  • the adhesive sheet may be a so-called "substrate-less type” adhesive sheet that does not have a substrate (substrate layer), or may be an adhesive sheet of a type that has a substrate.
  • the "substrate-less type” adhesive sheet may be referred to as a "substrate-less adhesive sheet”
  • the adhesive sheet of a type that has a substrate may be referred to as a "substrate-attached adhesive sheet”.
  • the substrate-less adhesive sheet may be a double-sided adhesive sheet consisting of only a multi-layer adhesive layer.
  • the substrate-attached adhesive sheet may be, for example, a single-sided adhesive sheet having an adhesive layer on one side of the substrate, or a double-sided adhesive sheet having adhesive layers on both sides of the substrate.
  • substrate substrate layer
  • the "substrate (substrate layer)" refers to a support, and is the part that is attached to the substrate together with the adhesive layer when the adhesive sheet is used (attached) to the substrate.
  • the release liner that is peeled off when the adhesive sheet is used (attached) is not included in the substrate.
  • the L * of one side of the pressure-sensitive adhesive sheet is 35 to 75, preferably 40 to 72, and more preferably 45 to 70.
  • the L * of the other side of the pressure-sensitive adhesive sheet is 10 to 50 smaller than the L * of the one side. That is, [(L * of one side)-(L * of the other side)] is 10 to 50, preferably 15 to 45, and more preferably 20 to 40.
  • the L * of one side be 35 or more and the difference between the L * of one side and the L * of the other side be 50 or less, the brightness of the one side can be high and the design of the adherend can be excellent.
  • the L * of one side be 75 or less and the difference between the L * of one side and the L * of the other side be 10 or more, the brightness of the other side can be low and the light-shielding property can be excellent.
  • the L * of the other surface of the pressure-sensitive adhesive sheet is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less. When the L * of the other surface is 30 or less, the light-shielding properties are superior.
  • the L * of the other surface is preferably 10 or more, and more preferably 15 or more.
  • the light-shielding layer is not particularly limited as long as it is a layer constituting the pressure-sensitive adhesive sheet.
  • a substrate, a pressure-sensitive adhesive layer, a printed layer (ink layer), etc. can be mentioned.
  • the light-shielding layer is a layer having a function of blocking the transmission of light.
  • the light-shielding layer can be formed, for example, as a light-shielding printed layer, a light-shielding substrate, a light-shielding pressure-sensitive adhesive layer, etc., by adding a coloring material that exhibits black color when forming each layer.
  • the light-shielding layer may be a single layer, or may be a multi-layer structure composed of layers having the same or different compositions, thicknesses, physical properties, etc.
  • the light-shielding layer is a printed layer (light-shielding printed layer)
  • it is preferable that the light-shielding layer is a multi-layer structure.
  • the light-shielding layer can have a higher light-shielding property, and even when pinholes occur in each layer, the light-shielding layer can have sufficient light-shielding property.
  • Examples of the light-shielding layer having a multi-layer structure include a structure in which the light-shielding printed layer is laminated in multiple layers, and a laminate structure of a single or multiple light-shielding printed layer and a light-shielding adhesive layer. Each light-shielding layer in the multi-layer structure may be laminated directly or through another layer.
  • the number of layers of the light-shielding layer is 2 or more, for example, 2 to 10, preferably 2 to 8, more preferably 2 to 5, and even more preferably 3 to 4.
  • the colorants that produce the black color can also be a colorant mixture made by mixing multiple colorants selected from black colorants, cyan colorants (blue-green colorants), magenta colorants (red-purple colorants), and yellow colorants (yellow colorants).
  • the black colorant may be any colorant (coloring agent) such as a pigment or a dye, but a pigment is preferred.
  • the black colorant include carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (non-magnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, composite oxide black pigment, anthraquinone organic black pigment, etc.
  • One or more of the black colorants may be used. Among them, carbon black is preferred from the viewpoints of cost and availability.
  • examples of the pigment include C.I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17, 17:1, 18, 22, 25, 56, 60, 63, 65, 66; C.I. Bat Blue 4; 60; C.I. Pigment Green 7, etc.
  • examples of the dye include C.I. Solvent Blue 25, 36, 60, 70, 93, 95; C.I. Acid Blue 6, 45, etc.
  • magenta pigment examples include C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 42, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 50, 51, 52, 52:2, 53:1, 54, 55, 56, 57:1, 58, 60, 60:1, 63, 63:1, 63:2, 64, 64:1, 6 C.I.7, 68, 81, 83, 87, 88, 89, 90, 92, 101, 104, 105, 106, 108, 112, 114, 122, 123, 139, 144, 146, 147, 149, 150, 151, 163, 166, 168, 170, 171, 172, 175, 176, 177, 178, 179, 184, 185, 187, 190, 193, 202, 206, 207
  • examples of the dye include C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, and 122; C.I. Disperse Red 9; C.I. Solvent Violet 8, 13, 14, 21, and 27; C.I. Disperse Violet 1; C.I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C.I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28, etc.
  • examples of the pigment include C.I. Pigment Orange 31 and 43; C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 24, 34, 35, 37, 42, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, and 100; C.I. Bat Yellow 1, 3, 20, etc.
  • examples of the dye include C.I.
  • Solvent Yellow 19 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 113, 114, 116, 117, 120, 128, 129, 133, 138, 139, 147, 150, 151, 153, 154, 155, 156, 167, 172, 173, 180, 185, 195; C.I. Bat Yellow 1, 3, 20, etc.
  • examples of the dye include C.I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, etc.
  • the light-shielding printing layer contains the black coloring material and, if necessary, a binder.
  • the binder is not particularly limited, and examples thereof include polyurethane resins, phenol resins, epoxy resins, urea melamine resins, silicone resins, phenoxy resins, methacrylic resins, acrylic resins, polyarylate resins, polyester resins (polyethylene terephthalate, etc.), polyolefin resins (polyethylene, polypropylene, ethylene-propylene copolymers, etc.), polystyrene resins (polystyrene, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, styrene-maleic anhydride copolymers, acrylonitrile-butadiene-styrene resins, etc.), polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyvinyl a
  • the light-blocking printed layer can be formed by applying an ink composition (black ink composition) containing the black colorant and, if necessary, a binder, dispersant, solvent, etc., onto a support (e.g., a substrate), and drying and curing it as necessary.
  • an ink composition black ink composition
  • a binder e.g., a binder
  • dispersant e.g., solvent
  • solvent e.g., a substrate
  • Methods for forming the light-blocking printed layer include known or commonly used coating methods and methods using various printing methods (gravure printing, flexographic printing, offset printing, letterpress printing, screen printing, etc.).
  • the thickness (total thickness) of the light-blocking printed layer is not particularly limited, but is preferably 1 to 20 ⁇ m, and more preferably 2 to 10 ⁇ m. If the thickness is 1 ⁇ m or more, more sufficient light-blocking properties can be obtained. If the thickness is 20 ⁇ m or less, the thickness of the adhesive sheet can be made thinner.
  • the light-shielding substrate may be one in which the above-mentioned black coloring material is mixed into the components constituting the substrate.
  • the above-mentioned black coloring material may be mixed into the resin constituting the substrate, which will be described later. Only one type of resin may be used, or two or more types may be used.
  • the thickness (total thickness) of the light-shielding substrate is not particularly limited, but is preferably 10 to 50 ⁇ m, and more preferably 20 to 40 ⁇ m. If the thickness is 10 ⁇ m or more, more sufficient light-shielding properties can be obtained. If the thickness is 50 ⁇ m or less, the thickness of the adhesive sheet can be made thinner.
  • the adhesive constituting the light-shielding adhesive layer is not particularly limited, and any known or commonly used adhesive may be used, such as the adhesives described below. Only one type of adhesive may be used, or two or more types may be used.
  • the colorant is not particularly limited, and for example, a component capable of absorbing and attenuating the light traveling through the adhesive layer is used.
  • a black colorant is preferable because the light blocking properties can be efficiently adjusted with a small amount of the colorant.
  • the black colorant include carbon black, graphite, aniline black, perylene black, cyanine black, titanium black, inorganic pigment hematite, activated carbon, molybdenum disulfide, chromium complexes, anthraquinone-based colorants, and the like.
  • the black colorant may be used alone or in combination of two or more.
  • the light-shielding adhesive layer preferably contains carbon black particles as the colorant.
  • carbon black particles those generally called carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, pine soot, etc.) can be used without any particular restrictions.
  • Surface-modified carbon black particles having functional groups such as carboxy groups, amino groups, sulfonic acid groups, and silicon-containing groups (e.g., alkoxysilyl groups, alkylsilyl groups) may also be used as the carbon black particles.
  • Such surface-modified carbon black particles are also called self-dispersing carbon black, and have the effect of reducing the amount of dispersant added or eliminating the need for it.
  • a particulate colorant (particularly a pigment) can be preferably used because the light-blocking properties of the adhesive layer can be efficiently adjusted with a small amount of colorant.
  • the average particle diameter of the particulate colorant is, for example, about 10 nm or more, and may be 30 nm or more, 50 nm or more, 100 nm or more, or 150 nm or more. From the viewpoint of improving the light-blocking properties, the average particle diameter of the particulate colorant is, for example, 3000 nm or less, and may be 1000 nm or less, 500 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 120 nm or less, or 100 nm or less. If the average particle diameter is small, the dispersibility of the colorant in the adhesive layer is improved, and the light-blocking properties can be further improved.
  • the above average particle size can be determined as the volume average particle size, and specifically refers to the particle size at an integrated value of 50% in the particle size distribution measured using a particle size distribution measuring device based on the laser scattering/diffraction method (50% volume average particle size; hereinafter sometimes abbreviated as D50).
  • a particle size distribution measuring device based on the laser scattering/diffraction method (50% volume average particle size; hereinafter sometimes abbreviated as D50).
  • a product name "Microtrac MT3000II" manufactured by Microtrac Bell or an equivalent product can be used.
  • the colorant preferably has a standard deviation in the particle size distribution based on the number of particles observed by TEM of less than 200 nm. This increases the proportion of particles in a particle size range with excellent light absorption properties, and provides better light blocking properties.
  • the standard deviation is more preferably less than 150 nm, even more preferably less than 100 nm, and particularly preferably less than 80 nm (e.g., less than 50 nm).
  • the standard deviation is, for example, 10 nm or more, preferably 20 nm or more, and more preferably 30 nm or more.
  • the colorant may be added to the adhesive composition in the form of a dispersion liquid in which it is dispersed in a dispersion medium.
  • the dispersion medium is not particularly limited, but may include water (ion-exchanged water, reverse osmosis water, distilled water, etc.), various organic solvents (alcohols such as ethanol; ketones such as acetone; ethers such as butyl cellosolve and propylene glycol monomethyl ether acetate; esters such as ethyl acetate; aromatic hydrocarbons such as toluene; and mixed solvents thereof), and aqueous mixed solvents of water and the organic solvents.
  • the dispersion liquid may contain a dispersant. By mixing the dispersion liquid with the adhesive composition, the adhesive composition contains the colorant and may also contain a dispersant.
  • the content of the colorant in the light-shielding adhesive layer is not particularly limited, but is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 4% by mass or more, relative to 100% by mass of the total amount of the light-shielding adhesive layer.
  • the content of the colorant is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.
  • the thickness (total thickness) of the light-blocking adhesive layer is not particularly limited, but is preferably 1 to 30 ⁇ m, and more preferably 5 to 20 ⁇ m. If the thickness is 1 ⁇ m or more, more sufficient light-blocking properties can be obtained. If the thickness is 30 ⁇ m or less, the thickness of the adhesive sheet can be made thinner.
  • the white layer is not particularly limited as long as it is a layer constituting the pressure-sensitive adhesive sheet. Examples include a substrate, a pressure-sensitive adhesive layer, a printed layer (ink layer), etc. Among them, the white layer is preferably a substrate or a printed layer, more preferably a printed layer, from the viewpoint of easily setting the [(L * of one side)-(L * of the other side)] to the above-mentioned specific range.
  • the white layer is a colored layer that exhibits a white color.
  • the white layer can be formed, for example, as a white printed layer, a white substrate, a white adhesive layer, etc.
  • the white layer may be a single layer, or may be a multi-layer structure composed of layers that are the same or have different compositions, thicknesses, physical properties, etc.
  • An example of a multi-layer structure of the white layer is a structure in which multiple white printed layers are laminated. Each white layer in the multi-layer structure may be laminated directly, or may be laminated via another layer.
  • the number of layers of the white layer is 2 or more, for example 2 to 5, and preferably 2 to 3.
  • the white layer preferably has an L * value of 75 or more (75 to 100) in the L * a * b * color system, more preferably 80 or more, and even more preferably 85 or more.
  • the a * and b* values in the L * a * b * color system can be appropriately selected according to the value of L * .
  • a * and/or b * are preferably -10 to 10, more preferably -5 to 5, even more preferably -2 to 2, and particularly preferably 0.
  • Examples of the coloring materials that exhibit the above-mentioned white color include titanium oxide (rutile type titanium dioxide, anatase type titanium dioxide, and other titanium dioxides), zinc oxide, aluminum oxide, silicon oxide, zirconium oxide, magnesium oxide, calcium oxide, tin oxide, barium oxide, cesium oxide, yttrium oxide, magnesium carbonate, calcium carbonate (light calcium carbonate, heavy calcium carbonate, and other), barium carbonate, zinc carbonate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, aluminum silicate, magnesium silicate, silicon
  • Examples of the white coloring materials include inorganic white coloring materials such as calcium carbonate, barium sulfate, calcium sulfate, barium stearate, zinc oxide, zinc sulfide, talc, silica, alumina, clay, kaolin, titanium phosphate, mica, gypsum, white carbon, diatomaceous earth, bentonite, lithopone, zeolite, sericite, and
  • the white printed layer contains a colorant that exhibits the white color, and, if necessary, a binder.
  • a binder examples include those exemplified and explained as binders that may be contained in the light-blocking printed layer. Only one type of binder may be used, or two or more types may be used. In addition, the solvent is appropriately selected depending on the type of colorant and binder.
  • the white print layer can be formed by applying an ink composition (white ink composition) containing the above-mentioned white colorant and, if necessary, a binder, dispersant, solvent, etc., onto a support (e.g., a substrate), and drying and curing it as necessary.
  • an ink composition white ink composition
  • a binder e.g., a binder
  • dispersant e.g., solvent
  • solvent e.g., a substrate
  • Methods for forming the white printed layer include known or conventional coating methods and methods using various printing methods (gravure printing, flexographic printing, offset printing, letterpress printing, screen printing, etc.).
  • the thickness (total thickness) of the white printed layer is not particularly limited, but is preferably 0.7 ⁇ m or more, more preferably 1 ⁇ m or more, and even more preferably 1.5 ⁇ m or more. If the thickness is 0.7 ⁇ m or more, more sufficient design properties can be obtained. In addition, the thickness of the white printed layer is not particularly limited, but is, for example, 20 ⁇ m or less, and preferably 10 ⁇ m or less. If the thickness is 20 ⁇ m or less, more sufficient light blocking properties can be obtained.
  • the white base material may be a mixture of the above-mentioned white coloring material in the components constituting the base material.
  • the above-mentioned white coloring material may be a mixture of the resin constituting the base material described below. Only one type of resin may be used, or two or more types may be used.
  • the thickness (total thickness) of the white substrate is not particularly limited, but is preferably 10 to 50 ⁇ m, and more preferably 20 to 40 ⁇ m. If the thickness is 10 ⁇ m or more, more sufficient design properties can be obtained. If the thickness is 50 ⁇ m or less, more sufficient light blocking properties can be obtained.
  • the adhesive constituting the white adhesive layer is not particularly limited, and any known or commonly used adhesive may be used, such as the adhesives described below. Only one type of adhesive may be used, or two or more types may be used.
  • the thickness (total thickness) of the white adhesive layer is not particularly limited, but is preferably 1 to 30 ⁇ m, and more preferably 5 to 20 ⁇ m. If the thickness is 1 ⁇ m or more, more sufficient design properties can be obtained. If the thickness is 30 ⁇ m or less, more sufficient light blocking properties can be obtained.
  • the substrate is an element that functions as a support in the pressure-sensitive adhesive sheet.
  • the pressure-sensitive adhesive sheet preferably includes a substrate from the viewpoint of facilitating the formation of the light-shielding printed layer and the white printed layer.
  • the substrate may be a single layer or a laminate of the same or different substrates.
  • the substrate examples include plastic substrates (e.g., plastic films), porous materials such as paper, cloth, and nonwoven fabric, nets, and foam sheets.
  • the substrate is preferably a plastic substrate (particularly a plastic film). It is also preferable that the substrate is a non-foam sheet.
  • the resins constituting the plastic substrate include, for example, polyolefin resins such as low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, very low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ethylene-vinyl acetate copolymer (EVA), ionomer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, etc.; polyurethane resins; rubber resins (natural rubber, synthetic rubber, mixtures thereof, etc.): polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, polybutylene terephthalate (PBT), etc.;
  • the substrate may contain various additives, such as fillers (inorganic fillers, organic fillers, etc.), colorants (pigments or dyes), dispersants (surfactants, etc.), antioxidants, antioxidants, UV absorbers, antistatic agents, lubricants, plasticizers, etc., as necessary.
  • fillers inorganic fillers, organic fillers, etc.
  • colorants pigments or dyes
  • dispersants surfactants, etc.
  • antioxidants antioxidants
  • antioxidants antioxidants
  • UV absorbers antistatic agents
  • lubricants plasticizers, etc.
  • the surface of the substrate on the side having the adhesive layer or the printed layer may be subjected to a surface treatment, such as a physical treatment such as corona discharge treatment, plasma treatment, sand mat processing treatment, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, or ionizing radiation treatment; a chemical treatment such as chromate treatment; or an easy-adhesion treatment using a coating agent (primer), in order to improve adhesion and retention with the layer. It is preferable that the surface treatment for improving adhesion is applied to the entire surface of the substrate on the side where it is desired to improve adhesion.
  • a surface treatment such as a physical treatment such as corona discharge treatment, plasma treatment, sand mat processing treatment, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, or ionizing radiation treatment
  • a chemical treatment such as chromate treatment
  • an easy-adhesion treatment using a coating agent (primer) in order to improve adhesion and retention with the layer.
  • the thickness of the substrate is preferably 5 ⁇ m or more, more preferably 10 ⁇ m or more, from the viewpoint of excellent support function and surface scratch resistance.
  • the thickness of the substrate is preferably 50 ⁇ m or less, more preferably 40 ⁇ m or less.
  • the plurality of pressure-sensitive adhesive layers may be the same pressure-sensitive adhesive layer, or may be pressure-sensitive adhesive layers having different compositions, thicknesses, physical properties, etc.
  • the pressure-sensitive adhesive layer provided on one surface of the substrate in the substrate-attached pressure-sensitive adhesive sheet may be a single layer, or may be a multilayer composed of layers having the same composition or different compositions, thicknesses, physical properties, etc.
  • the adhesive constituting the adhesive layer may be any known or commonly used adhesive, and is not particularly limited. Examples include acrylic adhesives, rubber adhesives (natural rubber, synthetic rubber, mixtures of these, etc.), silicone adhesives, polyester adhesives, urethane adhesives, polyether adhesives, polyamide adhesives, fluorine adhesives, and styrene adhesives. Of these, acrylic adhesives are preferred as the adhesive constituting the adhesive layer in terms of adhesion, weather resistance, cost, and ease of adhesive design. One type of adhesive may be used, or two or more types may be used.
  • the acrylic adhesive contains an acrylic polymer as a base polymer.
  • the acrylic polymer is a polymer containing an acrylic monomer (a monomer having a (meth)acryloyl group in the molecule) as a monomer component constituting the polymer.
  • the acrylic polymer contains a structural unit derived from an acrylic monomer. Only one type of acrylic polymer may be used, or two or more types may be used.
  • the acrylic polymer may contain only one type of acrylic monomer as a monomer component, or two or more types.
  • “(meth)acrylic” refers to "acrylic” and/or “methacrylic” (either one or both of "acrylic” and “methacrylic"), and the same applies to others.
  • the base polymer refers to the main component of the polymer components in the adhesive constituting the adhesive layer, for example, a polymer component contained in an amount of more than 50 mass%.
  • the content of the base polymer in the adhesive layer is preferably 60 mass% or more, more preferably 70 mass% or more, relative to 100 mass% of the total amount of the adhesive layer.
  • the acrylic polymer is preferably a polymer containing the largest amount of structural units derived from (meth)acrylic acid esters by mass.
  • the (meth)acrylic acid esters include hydrocarbon group-containing (meth)acrylic acid esters.
  • the hydrocarbon group-containing (meth)acrylic acid esters include (meth)acrylic acid alkyl esters having a linear or branched aliphatic hydrocarbon group, (meth)acrylic acid esters having an alicyclic hydrocarbon group such as (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid esters having an aromatic hydrocarbon group such as (meth)acrylic acid aryl esters. Only one type of the hydrocarbon group-containing (meth)acrylic acid esters may be used, or two or more types may be used.
  • Examples of the (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, butyl ...
  • acrylates examples include isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate.
  • (meth)acrylic acid alkyl esters having a linear or branched aliphatic hydrocarbon group with a carbon number of 1 to 20 (preferably 2 to 12, more preferably 4 to 10) are preferred.
  • the carbon number is within the above range, it is easy to adjust the glass transition temperature of the acrylic polymer, and the adhesion can be made more appropriate.
  • Examples of (meth)acrylic acid esters having the above-mentioned alicyclic hydrocarbon group include (meth)acrylic acid esters having a monocyclic aliphatic hydrocarbon ring, such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate; (meth)acrylic acid esters having a bicyclic aliphatic hydrocarbon ring, such as isobornyl (meth)acrylate; and (meth)acrylic acid esters having a tricyclic or higher aliphatic hydrocarbon ring, such as dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and 2-eth
  • Examples of the (meth)acrylic acid ester having an aromatic hydrocarbon group include (meth)acrylic acid phenyl ester and (meth)acrylic acid benzyl ester.
  • the proportion of the hydrocarbon group-containing (meth)acrylic acid ester in all monomer components constituting the acrylic polymer is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and may be 80% by mass or more, 90% by mass or more, or 95% by mass or more, relative to the total amount (100% by mass) of all monomer components.
  • the proportion may be 99.9% by mass or less, 98% by mass or less, 95% by mass or less, 90% by mass or less, or 80% by mass or less, from the viewpoint of copolymerizing other monomer components and obtaining the effects of the other monomer components.
  • the acrylic polymer may contain structural units derived from other monomer components copolymerizable with the hydrocarbon group-containing (meth)acrylic acid ester for the purpose of improving cohesive strength, introducing crosslinking points, or other modifications.
  • the other monomer components include polar group-containing monomers such as hydroxy group-containing monomers, nitrogen atom-containing monomers, carboxy group-containing monomers, acid anhydride monomers, keto group-containing monomers, alkoxysilyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers. Only one type of the other monomer components may be used, or two or more types may be used.
  • hydroxy group-containing monomer examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.
  • Examples of the nitrogen atom-containing monomer include amide group-containing monomers, amino group-containing monomers, cyano group-containing monomers, and monomers having nitrogen atom-containing rings.
  • Examples of the amide group-containing monomers include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, N-methoxymethyl(meth)acrylamide, and N-butoxymethyl(meth)acrylamide.
  • amino group-containing monomers examples include aminoethyl(meth)acrylate, N,N-dimethylaminoethyl(meth)acrylate, and t-butylaminoethyl(meth)acrylate.
  • cyano group-containing monomers examples include acrylonitrile and methacrylonitrile.
  • Examples of monomers having a nitrogen atom-containing ring include N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, N-vinylcaprolactam, and N-(meth)acryloylmorpholine.
  • carboxyl group-containing monomer examples include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid.
  • acid anhydride monomer examples include maleic anhydride and itaconic anhydride.
  • keto group-containing monomer examples include diacetone (meth)acrylamide, diacetone (meth)acrylate, vinyl methyl ketone, vinyl ethyl ketone, allyl acetoacetate, and vinyl acetoacetate.
  • alkoxysilyl group-containing monomer examples include 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane.
  • Examples of the glycidyl group-containing monomer include glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate.
  • sulfonic acid group-containing monomer examples include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid.
  • Examples of the phosphate group-containing monomer include 2-hydroxyethyl acryloyl phosphate.
  • the total proportion of the polar group-containing monomers in all monomer components (100% by mass) constituting the acrylic polymer is not particularly limited, but from the viewpoint of better exerting the effect of using the polar group-containing monomers, it is preferably 0.1% by mass or more, and more preferably 1% by mass or more. Furthermore, from the viewpoint of obtaining a pressure-sensitive adhesive layer having appropriate flexibility, the total proportion is preferably 10% by mass or less, and more preferably 8% by mass or less.
  • the monomer components constituting the acrylic polymer may further include other monomers.
  • the other monomers include vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl laurate; aromatic vinyl compounds such as styrene, substituted styrenes ( ⁇ -methylstyrene, etc.), and vinyl toluene; olefin monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene; chlorine-containing monomers such as vinyl chloride and vinylidene chloride; alkoxy-containing monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; and vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether.
  • the proportion of the other monomers in the total amount of all monomer components constituting the acrylic polymer (100% by mass) may be, for example, 0.05% by mass or more, or 0.5% by mass or more.
  • the proportion may be, for example, 20% by mass or less, 10% by mass or less, 5% by mass or less, or may be substantially absent.
  • the weight average molecular weight (Mw) of the acrylic polymer is preferably 5 ⁇ 10 4 or more, more preferably 10 ⁇ 10 4 or more, even more preferably 20 ⁇ 10 4 or more, and particularly preferably 30 ⁇ 10 4 or more.
  • Mw weight average molecular weight
  • the Mw is preferably 500 ⁇ 10 4 or less.
  • a pressure-sensitive adhesive exhibiting moderate fluidity (mobility of polymer chains) is easily formed.
  • the acrylic polymer is obtained by polymerizing a composition containing at least an acrylic monomer.
  • the polymerization method is not particularly limited, but examples thereof include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a thermal polymerization method, and a polymerization method using active energy radiation (active energy radiation polymerization method).
  • the bulk polymerization method, the thermal polymerization method, and the active energy radiation polymerization method are preferred in terms of the transparency of the adhesive layer, cost, and the like.
  • the obtained acrylic polymer may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.
  • solvents may be used when polymerizing the monomer components.
  • examples of the above solvents include organic solvents such as esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and ketones such as methyl ethyl ketone and methyl isobutyl ketone. Only one of the above solvents may be used, or two or more of them may be used.
  • the polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization of the monomer components are not particularly limited and can be selected as appropriate.
  • the weight average molecular weight of the polymer can be controlled by the amount of polymerization initiator and chain transfer agent used and the reaction conditions, and the amount used is adjusted appropriately depending on the type of these.
  • a thermal polymerization initiator or a photopolymerization initiator can be used depending on the type of polymerization reaction. Only one type of the above polymerization initiators may be used, or two or more types may be used.
  • the thermal polymerization initiator is not particularly limited, but examples thereof include azo polymerization initiators, peroxide polymerization initiators (e.g., persulfates such as dibenzoyl peroxide, tert-butyl permaleate, potassium persulfate, etc., benzoyl peroxide, hydrogen peroxide, etc.), substituted ethane initiators such as phenyl-substituted ethane, aromatic carbonyl compounds, redox polymerization initiators, etc.
  • peroxide polymerization initiators e.g., persulfates such as dibenzoyl peroxide, tert-butyl permaleate, potassium persulfate, etc., benzoyl peroxide, hydrogen peroxide, etc.
  • substituted ethane initiators such as phenyl-substituted ethane, aromatic carbonyl compounds
  • redox polymerization initiators etc.
  • azo polymerization initiator examples include 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2-methylpropionate)dimethyl, and 4,4'-azobis-4-cyanovaleric acid.
  • the amount of the thermal polymerization initiator used may be any amount that is normally used, and can be selected, for example, from the range of 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, per 100 parts by mass of the monomer component.
  • the photopolymerization initiator is not particularly limited, but examples thereof include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, ⁇ -ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators.
  • acylphosphine oxide-based photopolymerization initiators examples include acylphosphine oxide-based photopolymerization initiators and titanocene-based photopolymerization initiators.
  • benzoin ether-based photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether.
  • Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, and 4-(t-butyl)dichloroacetophenone.
  • Examples of the ⁇ -ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one.
  • Examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalenesulfonyl chloride.
  • Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(O-ethoxycarbonyl)-oxime.
  • Examples of the benzoin-based photopolymerization initiator include benzoin.
  • Examples of the benzyl-based photopolymerization initiator include benzyl.
  • Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinyl benzophenone, and ⁇ -hydroxycyclohexyl phenyl ketone.
  • Examples of the ketal-based photopolymerization initiator include benzyl dimethyl ketal.
  • Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.
  • Examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.
  • titanocene photopolymerization initiator examples include bis( ⁇ 5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium.
  • the amount of the photopolymerization initiator used may be a normal amount, and may be selected from the range of, for example, 0.01 to 5 parts by mass, preferably 0.05 to 3 parts by mass, per 100 parts by mass of the monomer component.
  • the acrylic polymer may contain a structural portion derived from the crosslinking agent. That is, the acrylic polymer may be crosslinked by the crosslinking agent.
  • a crosslinking agent By using a crosslinking agent, a crosslinked structure is formed in the acrylic polymer in the acrylic adhesive layer, and the gel fraction can be controlled.
  • the crosslinking agent By using the crosslinking agent, a crosslinked structure of the base polymer is formed in the adhesive layer, improving the cohesive force. Only one type of crosslinking agent may be used, or two or more types may be used.
  • crosslinking agents are not particularly limited, but examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, amine-based crosslinking agents, hydrazine-based crosslinking agents, silicone-based crosslinking agents, and silane-based crosslinking agents (silane coupling agents).
  • the content of the crosslinking agent is not particularly limited, but is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and particularly preferably 0.5 to 10 parts by mass, per 100 parts by mass of the total amount of the monomer components constituting the acrylic polymer.
  • the isocyanate crosslinking agent is a compound having an average of two or more isocyanate groups per molecule (a polyfunctional isocyanate compound).
  • examples of the isocyanate crosslinking agent include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates.
  • aliphatic polyisocyanates examples include 1,2-ethylene diisocyanate; tetramethylene diisocyanates such as 1,2-tetramethylene diisocyanate, 1,3-tetramethylene diisocyanate, and 1,4-tetramethylene diisocyanate; hexamethylene diisocyanates such as 1,2-hexamethylene diisocyanate, 1,3-hexamethylene diisocyanate, 1,4-hexamethylene diisocyanate, 1,5-hexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, and 2,5-hexamethylene diisocyanate; 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, and lysine diisocyanate.
  • 1,2-ethylene diisocyanate examples include 1,2-ethylene diisocyanate; tetramethylene diisocyanates such as 1,2-tetramethylene diisocyanate,
  • alicyclic polyisocyanates examples include isophorone diisocyanate; cyclohexyl diisocyanates such as 1,2-cyclohexyl diisocyanate, 1,3-cyclohexyl diisocyanate, and 1,4-cyclohexyl diisocyanate; cyclopentyl diisocyanates such as 1,2-cyclopentyl diisocyanate and 1,3-cyclopentyl diisocyanate; hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethylxylene diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate.
  • aromatic polyisocyanates examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, and 2,2'-diphenylpropane-4,4'-diisocyanate.
  • the above-mentioned isocyanate-based crosslinking agents also include commercially available products such as trimethylolpropane/tolylene diisocyanate adduct (product name "Coronate L”, manufactured by Tosoh Corporation), trimethylolpropane/hexamethylene diisocyanate adduct (product name "Coronate HL”, manufactured by Tosoh Corporation), and trimethylolpropane/xylylene diisocyanate adduct (product name "Takenate D-110N", manufactured by Mitsui Chemicals, Inc.).
  • the content of the isocyanate-based crosslinking agent is not particularly limited, but is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 1.5 parts by mass or more, relative to 100 parts by mass of the total amount of the monomer components constituting the acrylic polymer.
  • the content is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less.
  • epoxy crosslinking agent examples include N,N,N',N'-tetraglycidyl-m-xylylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglyceryl diglycidyl ether, ethylene glycol diglycidyl ether, propylene ...
  • Examples of the epoxy crosslinking agent include glycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule.
  • Examples of the epoxy crosslinking agent include commercially available products such as "Tetrad C" (manufactured by Mitsubishi Gas Chemical Co., Ltd.).
  • the content of the epoxy-based crosslinking agent is not particularly limited, but is preferably more than 0 parts by mass and not more than 1 part by mass, more preferably 0.001 to 0.5 parts by mass, even more preferably 0.002 to 0.2 parts by mass, even more preferably 0.005 to 0.1 parts by mass, even more preferably 0.008 to 0.1 parts by mass, and particularly preferably 0.009 to 0.05 parts by mass, relative to 100 parts by mass of the total amount of the monomer components constituting the acrylic polymer.
  • any agent that generates radical active species by heat and promotes crosslinking of the base polymer can be used as appropriate, but taking into consideration workability and stability, it is preferable to use a peroxide with a one-minute half-life temperature of 80 to 160°C, and it is even more preferable to use a peroxide with a one-minute half-life temperature of 90 to 140°C.
  • peroxide-based crosslinking agents examples include di(2-ethylhexyl)peroxydicarbonate (1-minute half-life temperature: 90.6°C), di(4-t-butylcyclohexyl)peroxydicarbonate (1-minute half-life temperature: 92.1°C), di-sec-butylperoxydicarbonate (1-minute half-life temperature: 92.4°C), t-butylperoxyneodecanoate (1-minute half-life temperature: 103.5°C), t-hexylperoxypivalate (1-minute half-life temperature: 109.1°C), t-butylperoxypivalate (1-minute half-life temperature: 110.3°C), dilauroylperoxy 1-minute half-life temperature: 116.4°C), di-n-octanoyl peroxide (1-minute half-life temperature: 117.4°C), 1,1,3,3-tetramethylbutylperoxy-2-ethylhex
  • the half-life of the peroxide-based crosslinking agent is an index showing the decomposition rate of the peroxide, and refers to the time until the remaining amount of peroxide is reduced to half.
  • the decomposition temperature for obtaining the half-life at any time and the half-life time at any temperature are described in the manufacturer's catalog, for example, NOF Corp.'s "Organic Peroxide Catalog 9th Edition (May 2003)".
  • the amount of decomposed peroxide remaining after the reaction can be measured, for example, by HPLC (high performance liquid chromatography).
  • the content of the crosslinking agent is not particularly limited, but it is preferably 2 parts by mass or less, more preferably 0.02 to 2 parts by mass, and even more preferably 0.05 to 1 part by mass, per 100 parts by mass of the total amount of the monomer components constituting the acrylic polymer.
  • the crosslinking agent may be used in combination with an organic crosslinking agent or a polyfunctional metal chelate.
  • a polyfunctional metal chelate is a compound in which a polyvalent metal is covalently or coordinately bonded to an organic compound.
  • polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, and Ti.
  • Examples of atoms in organic compounds that form covalent or coordinate bonds include oxygen atoms, and examples of organic compounds include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.
  • crosslinking agents it is preferable to include an isocyanate-based crosslinking agent. It is also more preferable to include another crosslinking agent together with the isocyanate-based crosslinking agent. As the other crosslinking agent, an epoxy-based crosslinking agent is preferable. When such a crosslinking agent is used in combination with the acrylic polymer (particularly in combination with the above-mentioned preferred acrylic polymer), a pressure-sensitive adhesive layer that is thin but has excellent adhesion can be obtained.
  • the adhesive layer may contain a tackifier resin.
  • the adhesive layer tends to have better adhesion even if it is thin.
  • the adhesive layer contains an acrylic adhesive and a tackifier resin, it has excellent adhesion to the adherend and is less likely to peel off.
  • tackifier resin examples include phenol-based tackifier resins, terpene-based tackifier resins, rosin-based tackifier resins, hydrocarbon-based tackifier resins, epoxy-based tackifier resins, polyamide-based tackifier resins, elastomer-based tackifier resins, and ketone-based tackifier resins. Only one type of the tackifier resins may be used, or two or more types may be used.
  • phenol-based tackifier resin examples include terpene phenol resin, hydrogenated terpene phenol resin, alkyl phenol resin, and rosin phenol resin.
  • the terpene phenol resin is a polymer containing terpene residues and phenol residues, and examples thereof include copolymers of terpenes and phenolic compounds (terpene-phenol copolymer resins) and homopolymers or copolymers of terpenes modified with phenol (phenol-modified terpene resins).
  • terpenes constituting the terpene phenol resin include monoterpenes such as ⁇ -pinene, ⁇ -pinene, and limonene (d-, l-, and d/l-forms (dipentene), etc.).
  • the hydrogenated terpene phenol resin is a resin having a structure obtained by hydrogenating the terpene phenol resin.
  • the alkyl phenol resin is a resin (oil-based phenol resin) obtained from an alkylphenol and formaldehyde. Examples of the alkyl phenol resin include novolac type and resol type.
  • the rosin phenol resin is a phenol-modified product of rosins or various rosin derivatives described below. The rosin phenol resin can be obtained, for example, by adding phenol to rosins or various rosin derivatives described below using an acid catalyst and then thermally polymerizing the mixture.
  • the above-mentioned terpene-based tackifying resins include polymers of terpenes (typically monoterpenes) such as ⁇ -pinene, ⁇ -pinene, d-limonene, l-limonene, and dipentene.
  • the above-mentioned terpene polymers may be homopolymers of one type of terpene, or copolymers of two or more types of terpenes. Examples of homopolymers of one type of terpene include ⁇ -pinene polymer, ⁇ -pinene polymer, and dipentene polymer.
  • modified terpene-based tackifying resins are those obtained by modifying the above-mentioned terpene resins (modified terpene resins).
  • modified terpene resins include styrene-modified terpene resins and hydrogenated terpene resins.
  • Examples of the rosin-based tackifier resin include rosins and rosin derivative resins.
  • the rosins include unmodified rosins (raw rosins) such as gum rosin, wood rosin, and tall oil rosin; modified rosins obtained by modifying these unmodified rosins through hydrogenation, disproportionation, polymerization, etc. (hydrogenated rosin, disproportionated rosin, polymerized rosin, other chemically modified rosins, etc.).
  • Examples of the rosin derivative resin include derivatives of the rosins.
  • rosin derivative resin examples include rosin esters such as unmodified rosin esters, which are esters of unmodified rosin and alcohols, and modified rosin esters, which are esters of modified rosin and alcohols; unsaturated fatty acid modified rosins obtained by modifying rosin with unsaturated fatty acids; unsaturated fatty acid modified rosin esters obtained by modifying rosin esters with unsaturated fatty acids; rosin alcohols obtained by reducing the carboxyl groups of rosins or the various rosin derivatives described above; and metal salts of rosins or the various rosin derivatives described above.
  • Specific examples of the rosin esters include methyl esters of unmodified or modified rosin, triethylene glycol esters, glycerin esters, pentaerythritol esters, etc.
  • hydrocarbon tackifying resins include aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aliphatic and aromatic petroleum resins (styrene-olefin copolymers, etc.), aliphatic and alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone resins, and coumarone-indene resins.
  • the content of the tackifier resin in the adhesive layer is not particularly limited, but is, for example, 1 part by mass or more (e.g., 1 to 100 parts by mass) relative to 100 parts by mass of the total amount of the base polymer, and is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more.
  • the content is 1 part by mass or more, the adhesive layer has even better adhesion even if it is thin.
  • the content is preferably 100 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less.
  • the adhesive layer may further contain additives such as crosslinking agents, crosslinking accelerators, antiaging agents, antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, UV absorbers, polymerization inhibitors, foil-like materials, rust inhibitors, colorants (dyes, pigments, etc.), and fillers, as necessary, to the extent that the effects of the present invention are not impaired. Only one type of each of the above additives may be used, or two or more types may be used. When the adhesive layer contains a colorant that exhibits black color as the colorant, it may be a light-shielding adhesive layer, and when the adhesive layer contains a colorant that exhibits white color as the colorant, it may be a white adhesive layer.
  • additives such as crosslinking agents, crosslinking accelerators, antiaging agents, antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, UV absorb
  • the thickness of the adhesive layer (total thickness of the adhesive layer on one side in the case of a double-sided adhesive sheet with a substrate) is not particularly limited, but is preferably 1 to 100 ⁇ m, more preferably 2 to 50 ⁇ m, and even more preferably 5 to 30 ⁇ m. If the thickness is 1 ⁇ m or more, the adhesive sheet has better adhesion. If the thickness of the adhesive layer is 100 ⁇ m or less, the adhesive sheet can be made thinner.
  • the thicknesses of the adhesive layers on both sides of a double-sided adhesive sheet with a substrate may be the same or different.
  • the adhesive layer may be in any form, such as an emulsion type, a solvent type (solution type), an active energy ray curing type, or a hot melt type.
  • solvent type and active energy ray curing type adhesive compositions are preferred because they are easy to obtain an adhesive layer with excellent productivity.
  • the active energy rays include, for example, ionizing radiation such as ⁇ rays, ⁇ rays, ⁇ rays, neutron rays, and electron beams, as well as ultraviolet rays, and ultraviolet rays are particularly preferred.
  • the active energy ray-curable adhesive layer is preferably an ultraviolet ray-curable adhesive layer.
  • the adhesive layer can be produced, for example, by applying (coating) an adhesive composition for forming the adhesive layer onto a release liner and drying and curing the resulting adhesive composition layer, or by applying (coating) the adhesive composition onto a release liner and irradiating the resulting adhesive composition layer with active energy rays to cure it. If necessary, the adhesive layer may be further dried by heating.
  • Examples of preferred laminated structures of the pressure-sensitive adhesive sheet include [adhesive layer/substrate/light-shielding printed layer/white printed layer/adhesive layer], [adhesive layer/light-shielding printed layer/substrate/light-shielding printed layer/white printed layer/adhesive layer], [adhesive layer/light-shielding printed layer/substrate/white printed layer/adhesive layer], [light-shielding adhesive layer/substrate/light-shielding printed layer/white printed layer/adhesive layer], [light-shielding adhesive layer/white printed layer/substrate/adhesive layer], [adhesive layer/light-shielding substrate/white printed layer/adhesive layer], [adhesive layer/light-shielding printed layer/white substrate/light-shielding printed layer/adhesive layer], and
  • the light-shielding printed layer and the white printed layer may be a single layer or multiple layers.
  • layers that are not labeled "light-shielding" or “white” are layers other than the light-shielding layer and the white layer (e.g., transparent layers).
  • the optical density of the adhesive sheet at a wavelength of 550 nm is preferably 3.0 or more, more preferably 3.5 or more, and even more preferably 4.0 or more. When the optical density is 3.0 or more, the light blocking properties are superior.
  • the thickness of the adhesive sheet is preferably 5 to 300 ⁇ m, more preferably 100 to 200 ⁇ m, and even more preferably 20 to 100 ⁇ m. If the thickness is 5 ⁇ m or more, the adhesiveness to the adherend is superior. If the thickness is 300 ⁇ m or less, the adhesive sheet can be made thinner. Note that the thickness of the adhesive sheet refers to the thickness from one adhesive surface to the other adhesive surface in the case of a double-sided adhesive sheet, and the thickness from the substrate surface to the adhesive surface in the case of a single-sided adhesive sheet, i.e., the thickness of the adhesive body, and does not include the release liner.
  • the above-mentioned pressure-sensitive adhesive sheet may have a release liner attached to the surface (adhesive surface) of the pressure-sensitive adhesive layer until it is used.
  • Each adhesive surface on both sides of the double-sided pressure-sensitive adhesive sheet may be protected by two release liners, or may be protected by a single release liner with both sides serving as release surfaces in a form wound into a roll (rolled body).
  • the release liner is used as a protective material for the pressure-sensitive adhesive layer, and is peeled off when the sheet is applied to the adherend. It is not necessary to provide a release liner.
  • the release liner may be a conventional release paper, and is not particularly limited.
  • the release liner include a substrate having a release treatment layer, a low-adhesion substrate made of a fluoropolymer, and a low-adhesion substrate made of a non-polar polymer.
  • the substrate having a release treatment layer include plastic films and papers that have been surface-treated with a release treatment agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide release agent.
  • fluorine-based polymer in the low-adhesion substrate made of a fluoropolymer examples include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer.
  • non-polar polymer include olefin resins (e.g., polyethylene, polypropylene, etc.).
  • the release liner can be formed by a known or conventional method. The thickness of the release liner is also not particularly limited.
  • FIGS 1 to 7 show schematic cross-sectional views of one embodiment of the adhesive sheet of the present invention.
  • the adhesive sheet (double-sided adhesive sheet) 1 shown in Figure 1 comprises a substrate 2, a transparent adhesive layer 5a provided on one side of the substrate 2, a light-blocking printed layer 3 which is a black printed layer provided on the other side of the substrate 2, a white printed layer 4 provided on the surface of the light-blocking printed layer 3, and a transparent adhesive layer 5b provided on the surface of the white printed layer 4.
  • the light-blocking printed layer 3 and the white printed layer 4 may each be formed of a single printed layer or multiple printed layers.
  • a release liner may be provided on the surface of each of the transparent adhesive layer 5a and the transparent adhesive layer 5b.
  • the adhesive sheet (double-sided adhesive sheet) 1 shown in FIG. 2 is the same as the adhesive sheet 1 shown in FIG. 1, except that a light-shielding printed layer 3a, which is a black printed layer, is inserted between the substrate 2 and the transparent adhesive layer 5a. That is, the adhesive sheet 1 shown in FIG.
  • the light-shielding printed layer 3a which is a black printed layer provided on one side of the substrate 2, a transparent adhesive layer 5a provided on the surface of the light-shielding printed layer 3a, a light-shielding printed layer 3b, which is a black printed layer provided on the other side of the substrate 2, a white printed layer 4 provided on the surface of the light-shielding printed layer 3b, and a transparent adhesive layer 5b provided on the surface of the white printed layer 4.
  • the light-shielding printed layers 3a, 3b, and the white printed layer 4 may each be formed of a single printed layer or a multi-layer printed layer.
  • a release liner may be provided on the surface of each of the transparent adhesive layer 5a and the transparent adhesive layer 5b.
  • the adhesive sheet (double-sided adhesive sheet) 1 shown in FIG. 3 comprises a substrate 2, a light-blocking printed layer 3 which is a black printed layer provided on one side of the substrate 2, a transparent adhesive layer 5a provided on the surface of the light-blocking printed layer 3, a white printed layer 4 provided on the other side of the substrate 2, and a transparent adhesive layer 5b provided on the surface of the white printed layer 4.
  • the light-blocking printed layer 3 and the white printed layer 4 may each be formed of a single printed layer or multiple printed layers.
  • a release liner may be provided on the surface of each of the transparent adhesive layer 5a and the transparent adhesive layer 5b.
  • the adhesive sheet (double-sided adhesive sheet) 1 shown in FIG. 4 has the same structure as the adhesive sheet 1 shown in FIG. 1, except that the transparent adhesive layer 5a is replaced by the light-shielding adhesive layer 5c, which is a black adhesive layer. That is, the adhesive sheet 1 shown in FIG. 4 includes a substrate 2, a light-shielding adhesive layer 5c, which is a black adhesive layer provided on one side of the substrate 2, a light-shielding printed layer 3, which is a black printed layer provided on the other side of the substrate 2, a white printed layer 4 provided on the surface of the light-shielding printed layer 3, and a transparent adhesive layer 5b provided on the surface of the white printed layer 4.
  • the light-shielding printed layer 3 and the white printed layer 4 may each be formed of a single printed layer or a multi-layer printed layer.
  • a release liner may be provided on the surface of the light-shielding adhesive layer 5c and the transparent adhesive layer 5b.
  • the adhesive sheet shown in FIG. 5 comprises a substrate 2, a white printed layer 4 provided on one side of the substrate 2, a light-blocking adhesive layer 5c which is a black adhesive layer provided on the surface of the white printed layer 4, and a transparent adhesive layer 5b provided on the other side of the substrate 2.
  • the white printed layer 4 may be formed of a single printed layer or may be formed of multiple printed layers.
  • a release liner may be provided on the surface of each of the light-blocking adhesive layer 5c and the transparent adhesive layer 5b.
  • the adhesive sheet shown in FIG. 6 comprises a light-shielding substrate 2a which is a black substrate, a transparent adhesive layer 5a provided on one side of the light-shielding substrate 2a, a white printed layer 4 provided on the other side of the light-shielding substrate 2a, and a transparent adhesive layer 5b provided on the surface of the white printed layer 4.
  • the white printed layer 4 may be formed of a single printed layer or may be formed of multiple printed layers.
  • a release liner may be provided on the surface of each of the transparent adhesive layer 5a and the transparent adhesive layer 5b.
  • the adhesive sheet shown in FIG. 7 includes a white substrate 2b, a light-shielding printed layer 3a which is a black printed layer provided on one side of the white substrate 2b, a transparent adhesive layer 5a provided on the surface of the light-shielding printed layer 3a, a light-shielding printed layer 3b which is a black printed layer provided on the other side of the white substrate 2b, and a transparent adhesive layer 5b provided on the surface of the light-shielding printed layer 3b.
  • the light-shielding printed layers 3a and 3b may each be formed of a single printed layer or a multi-layer printed layer.
  • a release liner may be provided on the surface of the transparent adhesive layer 5a and the transparent adhesive layer 5b, respectively.
  • the adhesive sheet is preferably for attaching electrical and electronic components, by being attached to components included in electrical and electronic equipment.
  • the double-sided adhesive sheet is preferably used for attaching components included in electrical and electronic equipment to each of the two adhesive surfaces, i.e., for fixing components together in electrical and electronic equipment.
  • the double-sided adhesive sheet may be used either for fixing the components together, or for temporarily fixing them together.
  • electrical and electronic equipment refers to equipment that falls into at least one of the categories of electrical equipment and electronic equipment.
  • Examples of the electrical and electronic equipment include image display devices such as liquid crystal displays, electroluminescent displays, and plasma displays, as well as portable electronic devices.
  • Examples of the portable electronic devices include mobile phones, smartphones, tablet computers, notebook computers, various wearable devices (for example, wristwear devices worn on the wrist like a wristwatch, modular devices worn on a part of the body with a clip or strap, eyewear devices including glasses (monocular and binocular, including head-mounted devices), clothing devices attached to shirts, socks, hats, etc. as accessories, earwear devices attached to the ears like earphones, etc.), digital cameras, digital video cameras, audio devices (portable music players, IC recorders, etc.), calculators (calculators, etc.), portable game devices, electronic dictionaries, electronic organizers, electronic books, in-vehicle information devices, portable radios, portable televisions, portable printers, portable scanners, portable modems, etc.
  • various wearable devices for example, wristwear devices worn on the wrist like a wristwatch, modular devices worn on a part of the body with a clip or strap, eyewear devices including glasses (monocular and binocular, including head-mounted devices), clothing devices attached
  • portable does not mean that it is sufficient to simply be portable, but rather that it has a level of portability that allows an individual (average adult) to carry it relatively easily.
  • the adhesive sheet is used, for example, so that the adhesive layer adheres to the components of the portable electronic device.
  • the adhesive sheet of the present invention has sufficient light-blocking properties and can provide an adherend with excellent design. Therefore, when the adherend is a color other than black (e.g., gray), when the adhesive sheet (particularly the other surface of the adhesive sheet) is attached to the adherend, the adhesive sheet has sufficient light-blocking properties and is not likely to interfere with the design of the adherend. Therefore, even if the adherend is a sensor or SUS plate, the adhesive sheet has excellent design.
  • black e.g., gray
  • Preparation Example 1 (Preparation of Acrylic Polymer Solution A)
  • a reaction vessel equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, a reflux condenser, and a dropping funnel 95 parts by mass of butyl acrylate (BA) and 5 parts by mass of acrylic acid (AA) as monomer components, and 233 parts by mass of ethyl acetate as a polymerization solvent were charged, and the mixture was stirred for 2 hours while introducing nitrogen gas.
  • BA butyl acrylate
  • AA acrylic acid
  • ethyl acetate a polymerization solvent
  • Preparation Example 2 (Preparation of Transparent Adhesive Layer) To the acrylic polymer solution A prepared in Preparation Example 1, 30 parts by mass of a terpene phenol resin (trade name "YS Polystar S-145", softening point about 140-150°C, hydroxyl value 70-110 mgKOH/g, manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier resin, 2 parts by mass of an isocyanate-based crosslinking agent (trade name "Coronate L", manufactured by Tosoh Corporation) and 0.01 parts by mass of an epoxy-based crosslinking agent (trade name "Tetrad C", manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a crosslinking agent were added relative to 100 parts by mass of the acrylic polymer, and the mixture was stirred to prepare a pressure-sensitive adhesive composition.
  • a terpene phenol resin trade name "YS Polystar S-145", softening point about 140-150°C, hydroxyl value 70-110 mgKOH/
  • the pressure-sensitive adhesive composition was applied onto a release-treated layer of a 38 ⁇ m-thick polyethylene terephthalate film (product name "MRF#38", manufactured by Mitsubishi Chemical Co., Ltd.) one side of which had been subjected to a release treatment with silicone, and dried at 100°C for 2 minutes to form a transparent pressure-sensitive adhesive layer (thickness 10 ⁇ m).
  • Preparation Example 3 (Preparation of light-shielding pressure-sensitive adhesive layer A) To the acrylic polymer solution A prepared in Preparation Example 1, 30 parts by mass of a terpene phenol resin (product name "YS Polystar S-145", softening point about 140-150°C, hydroxyl value 70-110 mgKOH/g, manufactured by Yasuhara Chemical Co., Ltd.) as a tackifier resin, 2 parts by mass of an isocyanate-based crosslinking agent (product name "Coronate L", manufactured by Tosoh Corporation) and 0.01 parts by mass of an epoxy-based crosslinking agent (product name "Tetrad C", manufactured by Mitsubishi Gas Chemical Co., Ltd.) as crosslinking agents were added relative to 100 parts by mass of the acrylic polymer, and further carbon black particles (product name "Multilac A903", average particle size 350 nm, manufactured by Toyo Color Co., Ltd.) as a black colorant were added so that the amount of the carbon black particles in the adhesive layer was
  • the above adhesive composition was applied onto a release-treated layer of a 38 ⁇ m-thick polyethylene terephthalate film (product name "MRF#38", manufactured by Mitsubishi Chemical Corporation) with one side treated for release with silicone, and dried at 100° C. for 2 minutes to form a light-shielding adhesive layer A (thickness 10 ⁇ m).
  • Preparation Example 4 (Preparation of light-shielding pressure-sensitive adhesive layer B) A carbon black dispersion was prepared by adding carbon black particles and a dispersant to ethyl acetate as a dispersion medium so that the respective contents were about 30% by mass and about 1 to 5% by mass. The particle size distribution of the carbon black dispersion was measured based on a laser scattering/diffraction method (using a Microtrac MT3000II, a product of Microtrac Bell, Inc.; dispersion medium: ethyl acetate), and the average particle size (D50) [nm] was recorded. D50 was 150 nm.
  • the above adhesive composition was applied onto the release-treated layer of a 38 ⁇ m-thick polyethylene terephthalate film (product name "MRF#38", manufactured by Mitsubishi Chemical Corporation) with one side treated for release with silicone, and then dried at 100°C for 2 minutes to form a light-blocking adhesive layer B (thickness 10 ⁇ m).
  • Example 1 On one side of a polyethylene terephthalate (PET) film (trade name “Lumilar”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was printed in the order of black/black/black/white using a gravure printing method so that the black printed layer (light-shielding printed layer) was 2.0 ⁇ m and the white printed layer was about 0.8 ⁇ m, and a substrate with a printed layer having a total thickness of 18.8 ⁇ m was obtained.
  • PET polyethylene terephthalate
  • NB-300 manufactured by Dainichiseika Color & Chemicals Co., Ltd.
  • the transparent adhesive layers prepared in Preparation Example 2 were bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 38.8 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white printed layer/light-shielding printed layer (three layers)/transparent substrate/transparent adhesive layer (second side)].
  • Example 2 On one side of a polyethylene terephthalate (PET) film (trade name “Lumilar”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was multi-layer printed in the order of black/black/black/white using a gravure printing method so that each layer was about 2.0 ⁇ m thick, to obtain a substrate with a printed layer having a total thickness of 19.6 ⁇ m.
  • the transparent adhesive layers prepared in Preparation Example 2 were bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 39.6 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white printed layer/light-shielding printed layer (3 layers)/transparent substrate/transparent adhesive layer (second side)].
  • Example 3 On one side of a polyethylene terephthalate (PET) film (trade name “Lumilar”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was multi-layer printed in the order of black/black/black/black/white using a gravure printing method so that each layer was about 2.0 ⁇ m thick, to obtain a substrate with a printed layer having a total thickness of 22 ⁇ m.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 42 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white printed layer/light-shielding printed layer (four layers)/transparent substrate/transparent adhesive layer (second side)].
  • Example 4 On one side of a polyethylene terephthalate (PET) film (trade name “Lumilar”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was multi-layer printed in the order of black/black/black/white/white/white using a gravure printing method so that each layer was about 2.0 ⁇ m thick, to obtain a substrate with a printed layer having a total thickness of 24 ⁇ m.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 44 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white printed layer (3 layers)/light-shielding printed layer (3 layers)/transparent substrate/transparent adhesive layer (second side)].
  • Example 5 On one side of a polyethylene terephthalate (PET) film (trade name “Lumirror”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was multi-layer printed in the order of black/black using a gravure printing method so that each layer was about 2.0 ⁇ m thick. Also, on the other side of the PET film, ink (trade name "NB-300”, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was multi-layer printed in the order of black/black/white using a gravure printing method so that each layer was about 2.0 ⁇ m thick.
  • PET polyethylene terephthalate
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 42 ⁇ m and a release liner.
  • the double-sided pressure-sensitive adhesive sheet has a structure of [transparent pressure-sensitive adhesive layer (first side)/white printed layer (one layer)/light-blocking printed layer (two layers)/transparent substrate/light-blocking printed layer (two layers)/transparent pressure-sensitive adhesive layer (second side)].
  • Example 6 On one side of a polyethylene terephthalate (PET) film (trade name “Lumirror”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was multi-layer printed in the order of black/black/black using a gravure printing method so that each layer was about 2.0 ⁇ m thick. Also, on the other side of the PET film, ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was used to form a white printed layer with a thickness of about 2.0 ⁇ m using a gravure printing method.
  • PET polyethylene terephthalate
  • NB-300 manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 40 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white printed layer (one layer)/transparent substrate/light-shielding printed layer (three layers)/transparent adhesive layer (second side)].
  • Example 7 On one side of a polyethylene terephthalate (PET) film (trade name “Lumirror”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was multi-layer printed in the order of black/black/black/white using a gravure printing method so that the black printed layer (light-shielding printed layer) was 2.0 ⁇ m and the white printed layer was about 0.8 ⁇ m, to obtain a substrate with a printed layer having a total thickness of 18.8 ⁇ m.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to the printed layer-forming surface of this substrate with a printed layer.
  • the double-sided adhesive sheet has the following structure: transparent adhesive layer (first side)/white printed layer/light-shielding printed layer (three layers)/transparent substrate/light-shielding adhesive layer A (second side).
  • Example 8 On one side of a polyethylene terephthalate (PET) film (trade name “Lumilar”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was multi-layer printed in the order of black/black/black/white using a gravure printing method so that each layer was about 2.0 ⁇ m thick, to obtain a substrate with a printed layer having a total thickness of 19.6 ⁇ m.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to the printed layer-formed surface of this substrate with a printed layer.
  • the light-shielding adhesive layer A prepared in Preparation Example 3 was bonded to the non-printed layer-formed surface of the substrate with a printed layer so that the thickness was 10 ⁇ m. In this way, a double-sided adhesive sheet with a thickness of 39.6 ⁇ m and a release liner was obtained.
  • the double-sided adhesive sheet has the following structure: transparent adhesive layer (first side)/white printed layer/light-shielding printed layer (three layers)/transparent substrate/light-shielding adhesive layer A (second side).
  • Example 9 A white printed layer was formed on one side of a polyethylene terephthalate (PET) film (trade name “Lumilar”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.) using ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) by gravure printing to a thickness of about 2.0 ⁇ m, to obtain a substrate with a printed layer having a thickness of 13.6 ⁇ m.
  • the light-shielding adhesive layer B prepared in Preparation Example 4 was bonded to the printed layer-formed surface of the substrate with the printed layer to a thickness of 10 ⁇ m.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to the non-printed layer-formed surface of the substrate with the printed layer to a thickness of 10 ⁇ m. In this way, a double-sided adhesive sheet with a thickness of 33.6 ⁇ m and a release liner was obtained.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/transparent substrate/white printed layer/light-shielding adhesive layer B (second side)].
  • Example 10 A white printed layer was formed on one side of a black polyethylene terephthalate (PET) film (trade name “Lumirror #25-X36", thickness: 25 ⁇ m, manufactured by Toray Industries, Inc.) using ink (trade name "NB-300", manufactured by Dainichiseika Chemicals Co., Ltd.) by gravure printing to a thickness of about 2.0 ⁇ m, to obtain a substrate with a printed layer having a thickness of 26.6 ⁇ m.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of the substrate with the printed layer, respectively, to obtain a double-sided adhesive sheet with a release liner and a thickness of 46.6 ⁇ m.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white printed layer/light-shielding substrate/transparent adhesive layer (second side)].
  • Example 11 On one side of a white polyethylene terephthalate (PET) film (trade name “Lumirror #38-E20", thickness: 38 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was printed in a multilayer manner in the order of black/black/black using a gravure printing method so that each layer was about 2.0 ⁇ m thick. In addition, on the other side of the white PET film, ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Mfg.
  • the transparent adhesive layer prepared in Preparation Example 2 was attached to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 65.5 ⁇ m and a release liner.
  • the double-sided pressure-sensitive adhesive sheet has a structure of [transparent pressure-sensitive adhesive layer (first side)/light-shielding printed layer/white substrate/light-shielding printed layer (3 layers)/transparent pressure-sensitive adhesive layer (second side)].
  • Comparative Example 1 On one side of a white polyethylene terephthalate (PET) film (trade name “Lumirror #38-E20", thickness: 38 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was multi-layer printed in the order of white/silver/black/black/black using a gravure printing method so that each layer was about 2.0 ⁇ m thick, to obtain a substrate with a printed layer having a thickness of 48 ⁇ m.
  • PET white polyethylene terephthalate
  • the transparent adhesive layers prepared in Preparation Example 2 were bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 68 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white substrate/white printed layer/silver printed layer/light-shielding printed layer (3 layers)/transparent adhesive layer (second side)].
  • Comparative Example 2 On one side of a polyethylene terephthalate (PET) film (trade name “Lumirror”, thickness: 12 ⁇ m, manufactured by Toray Industries, Inc.), ink (trade name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was printed in the order of black/black/black/white using a gravure printing method so that the black printed layer (light-shielding printed layer) was 2.0 ⁇ m and the white printed layer was about 0.6 ⁇ m, and a substrate with a printed layer having a total thickness of 18.6 ⁇ m was obtained.
  • PET polyethylene terephthalate
  • the transparent adhesive layers prepared in Preparation Example 2 were bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 38.6 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white printed layer/light-shielding printed layer (three layers)/transparent substrate/transparent adhesive layer (second side)].
  • Comparative Example 3 The transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of a black polyethylene terephthalate (PET) film (product name "Lumirror #25-X36", thickness: 25 ⁇ m, manufactured by Toray Industries, Inc.) to obtain a 45 ⁇ m-thick double-sided adhesive sheet with a release liner.
  • PET polyethylene terephthalate
  • the double-sided adhesive sheet had a configuration of [transparent adhesive layer (first side)/light-shielding substrate/transparent adhesive layer (second side)].
  • Comparative Example 4 The transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of a white polyethylene terephthalate (PET) film (product name "Lumirror #38-E20", thickness: 38 ⁇ m, manufactured by Toray Industries, Inc.) to obtain a 58 ⁇ m-thick double-sided adhesive sheet with a release liner.
  • PET polyethylene terephthalate
  • the double-sided adhesive sheet had a configuration of [transparent adhesive layer (first side)/white substrate/transparent adhesive layer (second side)].
  • Comparative Example 5 On one side of a white polyethylene terephthalate (PET) film (product name “Lumirror #38-E20", thickness: 38 ⁇ m, manufactured by Toray Industries, Inc.), ink (product name "NB-300", manufactured by Dainichiseika Color & Chemicals Co., Ltd.) was multi-layer printed in the order of black/black/black using a gravure printing method so that each layer was about 2.0 ⁇ m thick, to obtain a substrate with a printed layer having a thickness of 44 ⁇ m.
  • the transparent adhesive layer prepared in Preparation Example 2 was bonded to both sides of this substrate with a printed layer, respectively, to obtain a double-sided adhesive sheet with a thickness of 64 ⁇ m and a release liner.
  • the double-sided adhesive sheet has a configuration of [transparent adhesive layer (first side)/white substrate/light-shielding printed layer (three layers)/transparent adhesive layer (second side)].
  • Comparative Example 6 The double-sided pressure-sensitive adhesive sheet (with a release liner) made of the light-shielding pressure-sensitive adhesive layer A prepared in Preparation Example 3 was used as the pressure-sensitive adhesive sheet of Comparative Example 6.
  • Comparative Example 7 The double-sided pressure-sensitive adhesive sheet (with release liner) made of the light-shielding pressure-sensitive adhesive layer B prepared in Preparation Example 4 was used as the pressure-sensitive adhesive sheet of Comparative Example 7.
  • the adherend was (product name "Decopane", expanded polystyrene panel, gray, L * : 57.8, manufactured by Koyo Sangyo Co., Ltd.).
  • ⁇ L was within the range of 10 ⁇ X ⁇ 50 and the absolute value of the difference in L * between the adherend and one side was 12 or less, it was evaluated as ⁇ ; when it was more than 12 and 20 or less, it was evaluated as ⁇ ; and when it was more than 20, it was evaluated as ⁇ .
  • the pressure-sensitive adhesive sheet of the present invention has an L * of 35 to 75 on the first side, an L * of 10 to 50 smaller than the L * of the first side, a high optical density, and a visual appearance inspection judgement of ⁇ or higher, and is evaluated as having sufficient light-shielding properties and being able to give the adherend excellent design.
  • ⁇ L was outside the range of 10 to 50
  • the visual appearance inspection judgement was ⁇
  • the sheet was evaluated as having poor light-shielding properties and/or poor design of the adherend (Comparative Example).
  • Adhesive sheet 2 Substrate 2a Light-shielding substrate 2b White substrate 3, 3a, 3b Light-shielding printed layer 4 White printed layers 5a, 5b Transparent adhesive layer 5c Light-shielding adhesive layer

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  • Laminated Bodies (AREA)

Abstract

L'invention concerne une feuille adhésive qui présente une capacité de blocage de lumière suffisante et qui peut fournir une conception supérieure à une partie adhérée.　Cette feuille adhésive est pourvue d'une structure stratifiée dotée d'une couche de blocage de lumière qui présente une couleur noire et d'une couche colorée qui présente une couleur blanche. En ce qui concerne L* indiqué par le système de couleurs L*a*b*, le L* d'une surface de la feuille adhésive est de 35 à 75 et le L* de l'autre surface est inférieur au L* de ladite surface de 10 à 50. Une feuille adhésive 1 est pourvue de : un matériau de base 2 ; une couche d'agent adhésif transparent 5a disposée sur une surface du matériau de base 2 ; une couche d'impression de blocage de lumière 3 qui est une couche d'impression noire disposée sur l'autre surface du matériau de base 2 ; une couche d'impression blanche 4 disposée sur la surface de la couche d'impression de blocage de lumière 3 ; et une couche d'agent adhésif transparent 5b disposée sur la surface de la couche d'impression blanche 4.
PCT/JP2023/029750 2022-09-29 2023-08-17 Feuille adhésive WO2024070311A1 (fr)

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JP2022-155918 2022-09-29
JP2022155918A JP2024049602A (ja) 2022-09-29 2022-09-29 粘着シート

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WO2024070311A1 true WO2024070311A1 (fr) 2024-04-04

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009020043A1 (fr) * 2007-08-03 2009-02-12 Sekisui Chemical Co., Ltd. Ruban adhésif pour ensemble de dispositif d'affichage et unité de module d'affichage utilisant le ruban adhésif
JP2010167642A (ja) * 2009-01-21 2010-08-05 Sekisui Chem Co Ltd 表示装置組み立て用粘着テープ及びこれを用いた表示モジュールユニット
WO2010106999A1 (fr) * 2009-03-17 2010-09-23 積水化学工業株式会社 Matériau de base de bande pour assembler un dispositif d'affichage et feuille adhésive pour assembler un dispositif d'affichage et unité de module d'affichage l'utilisant
JP2014005372A (ja) * 2012-06-25 2014-01-16 Nitto Denko Corp 粘着フィルム
WO2017109927A1 (fr) * 2015-12-24 2017-06-29 株式会社寺岡製作所 Bande adhésive
JP2020138532A (ja) * 2019-02-26 2020-09-03 Dic株式会社 着色フィルム、着色粘着シート、及び着色フィルムの検出方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009020043A1 (fr) * 2007-08-03 2009-02-12 Sekisui Chemical Co., Ltd. Ruban adhésif pour ensemble de dispositif d'affichage et unité de module d'affichage utilisant le ruban adhésif
JP2010167642A (ja) * 2009-01-21 2010-08-05 Sekisui Chem Co Ltd 表示装置組み立て用粘着テープ及びこれを用いた表示モジュールユニット
WO2010106999A1 (fr) * 2009-03-17 2010-09-23 積水化学工業株式会社 Matériau de base de bande pour assembler un dispositif d'affichage et feuille adhésive pour assembler un dispositif d'affichage et unité de module d'affichage l'utilisant
JP2014005372A (ja) * 2012-06-25 2014-01-16 Nitto Denko Corp 粘着フィルム
WO2017109927A1 (fr) * 2015-12-24 2017-06-29 株式会社寺岡製作所 Bande adhésive
JP2020138532A (ja) * 2019-02-26 2020-09-03 Dic株式会社 着色フィルム、着色粘着シート、及び着色フィルムの検出方法

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