Conductive laminates and conductive adhesive tapes

Abstract

This invention provides conductive laminates and conductive adhesive tapes with good alcohol resistance and surface insulation on the outermost surface, as well as excellent productivity. The invention provides conductive laminates, etc., having a conductive layer, an adhesive or bonding agent layer disposed on one side of the conductive layer, and a colored film layer disposed on the side of the adhesive or bonding agent layer opposite to the conductive layer. The conductive layer is a metal foil. The colored film layer has a resin film layer and a colored layer in contact with the side of the resin film layer opposite to at least the conductive layer. The colored layer comprises a cured resin and a coloring material, and the glass transition temperature of the colored layer is in the range of 43°C to 70°C.

Description

Technical Field

[0001] This invention relates to conductive laminates and conductive adhesive tapes. Background Technology

[0002] Conductive laminates and conductive adhesive tapes with conductive adhesive layers disposed on the laminates (hereinafter, conductive laminates and conductive adhesive tapes are sometimes collectively referred to as conductive laminates, etc.) are used for shielding unwanted leakage electromagnetic waves emitted from electrical and electronic equipment, shielding harmful spatial electromagnetic waves generated by other electrical and electronic equipment, and grounding to prevent static electricity, etc., based on their ease of operation.

[0003] With the miniaturization and thinning of electrical and electronic equipment, conductive laminates and the like require small overall thickness and thinness. In addition to being highly conductive, conductive laminates and the like also require that one surface (the side opposite to the conductive surface) be insulating in order to prevent short circuits caused by contact with other components.

[0004] Furthermore, in recent years, electrical and electronic equipment has achieved improvements in appearance and internal design, display image quality, and image recognition. In particular, attempts have been made to unify the color of electronic components built into the device to black, thereby improving internal design. Therefore, conductive laminates used in such internal design areas require high levels of blackness, such as jet black, matte finish, and concealment, to achieve a sense of unity with the black electronic components. It should be noted that in this specification, the design and blackness of conductive laminates refer primarily to the physical properties identifiable from the insulating side of the conductive laminate.

[0005] For example, Patent Document 1 discloses a conductive sheet comprising: a substrate on which metal layers are formed on both sides of a resin film as conductive layers; a light-shielding insulating layer disposed on a first main surface of the substrate; and a conductive adhesive layer disposed on a second main surface of the substrate. In the conductive sheet disclosed in Patent Document 1, a black coloring layer formed of an insulating resin colored with a black colorant is used as the light-shielding insulating layer.

[0006] In addition, Patent Document 2 discloses a sheet material in which a polyethylene terephthalate film is used as a substrate, an adhesive tape having a colored layer on one side of the substrate and a transparent adhesive layer on the other side is used, the adhesive tape is attached to the first main surface of a soft aluminum substrate that serves as a conductive layer, and another transparent adhesive layer is provided on the second main surface of the soft aluminum substrate. Existing technical documents Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2014-58108 Patent Document 2: Japanese Patent Application Publication No. 2017-8262 Patent Document 3: Japanese Patent Application Publication No. 2012-92281

[0008] However, to prevent foreign matter from entering the interior of electrical and electronic equipment, the surface of conductive laminates, such as the one opposite to the conductive layer side, is sometimes wiped with alcohol used to remove foreign matter. In this case, to avoid appearance defects caused by wiping, the coloring layer on the outermost surface of the conductive laminate, such as the one opposite to the conductive layer side, must be alcohol-resistant.

[0009] One method to improve the alcohol resistance of a coloring layer is to increase the hardness of the resin constituting the coloring layer (see, for example, Patent Document 3). However, when a coloring film with a coloring layer is formed on the surface of a resin film that serves as a substrate, if a coloring ink containing a resin with high hardness is printed onto the substrate of the film, the coloring film tends to curl significantly. In the manufacture of conductive laminates, especially when bonding with conductive layers, particularly thin metal layers, wrinkles and other defects can easily occur, leading to a lower yield of good products and other productivity problems. These defects become particularly pronounced when conductive laminates are manufactured continuously on a production line or when large-sized conductive laminates are manufactured.

[0010] Furthermore, in methods that directly form a coloring layer containing a hard resin on the surface of a conductive layer, the coloring layer monomers need to provide insulation; however, a thin coloring layer makes it difficult to ensure sufficient surface insulation. Additionally, to function as a coloring layer, an increased amount of colorant is required, and sometimes the insulation of the coloring layer is reduced due to the conductivity of the colorant.

[0011] Therefore, in conductive laminates and the like, there is a challenge in achieving both good alcohol resistance and surface insulation, as well as improving the productivity of conductive laminates. Summary of the Invention

[0012] The problem to be solved by the present invention is to provide a conductive laminate and conductive adhesive tape that exhibit good alcohol resistance and surface insulation on the outermost surface opposite to the conductive layer, as well as excellent productivity.

[0013] In order to achieve the above-mentioned objective, the inventors conducted in-depth research and found that the objective of the present invention can be achieved by using a conductive laminate having a colored film layer and a conductive adhesive tape having an adhesive layer disposed on the conductive laminate, thereby completing the present invention; the colored film layer has a colored layer and the colored layer has a specific glass transition temperature.

[0014] That is, the present invention provides a conductive laminate having a conductive layer, an adhesive or bonding agent layer disposed on one side of the conductive layer, and a colored film layer disposed on the side of the adhesive or bonding agent layer opposite to the conductive layer. The conductive layer is a metal foil, the colored film layer has a resin film layer and a colored layer in contact with the side of the resin film layer opposite to at least the conductive layer, the colored layer comprising a cured resin and a coloring material, and the glass transition temperature of the colored layer is in the range of 43°C to 70°C.

[0015] In addition, the present invention provides a conductive adhesive tape having the above-described conductive laminate and a conductive adhesive layer disposed on one side of the conductive layer of the above-described conductive laminate.

[0016] The conductive laminate and conductive adhesive tape of the present invention exhibit excellent alcohol resistance and surface insulation on the outermost surface opposite to the conductive layer, as well as excellent productivity. Therefore, the conductive laminate and conductive adhesive tape of the present invention are preferably used for protecting circuit components in portable electronic devices that require miniaturization, thinning, and high alcohol resistance and surface insulation. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view illustrating an example of the conductive laminate of the present invention. Figure 2 This is a schematic cross-sectional view showing an example of the conductive adhesive tape of the present invention. Detailed Implementation

[0018] The conductive laminate and conductive adhesive tape of the present invention will be described below.

[0019] I. Conductive laminate The conductive laminate of the present invention comprises a conductive layer, an adhesive or bonding agent layer disposed on one side of the conductive layer, and a colored film layer disposed on the side of the adhesive or bonding agent layer opposite to the conductive layer. The conductive layer is a metal foil. The colored film layer comprises a resin film layer and a colored layer in contact with the side of the resin film layer opposite to at least the conductive layer. The colored layer comprises a cured resin and a coloring material. The glass transition temperature of the colored layer is in the range of 43°C to 70°C.

[0020] Figure 1 This is a schematic cross-sectional view illustrating an example of the conductive laminate of the present invention. Figure 1The conductive laminate 10 of the present invention, as exemplified, comprises: a metal foil, i.e., a conductive layer 1; an adhesive layer or bonding agent layer 2 disposed on one side (first main surface) of the conductive layer 1; and a coloring film layer 3 disposed on the adhesive layer or bonding agent layer 2. The coloring film layer 3 comprises a resin film layer 4 and a coloring layer 5 in contact with the side of the resin film layer 4 opposite to the conductive layer 1. The coloring layer 5 contains a cured resin and a colorant, and has a glass transition temperature within a specified range. The resin film layer 4 forms one of the outermost surface layers (the surface on the side of the coloring film layer) of the conductive laminate 10 of the present invention.

[0021] The conductive laminate of the present invention comprises layers in which a conductive layer formed of metal foil, an adhesive or bonding agent layer, and a coloring film layer of desired configuration are sequentially stacked. The coloring layer has a glass transition temperature within a specified range, thereby exhibiting good alcohol resistance and high surface insulation on the surface of the coloring film layer side. Furthermore, the conductive laminate of the present invention is less prone to wrinkles during the bonding of the coloring film layer and the metal foil during its manufacturing process, enabling high-volume production.

[0022] The conductive laminate of the present invention has the following configuration: a colored film layer is disposed on one side (first main surface) of the conductive layer, i.e., the metal foil, separated by an adhesive layer or a bonding agent layer. Sometimes, the surface of the conductive laminate of the present invention located on the aforementioned side of the conductive layer (the side where the colored film layer is disposed separated by the adhesive layer or bonding agent layer) is referred to as the colored film side surface of the conductive laminate, and the surface located on the side of the conductive layer opposite to the aforementioned side (second main surface) is referred to as the conductive layer side surface of the conductive laminate. Furthermore, the conductive laminate of the present invention typically has a colored film layer on one side and a conductive layer on the other side.

[0023] The conductive laminate of the present invention will now be described in detail.

[0024] 1. Conductive layer The conductive layer in this invention is the layer that bears the conductivity of the conductive laminate. In this invention, the conductive layer is a metal foil. Here, metal foil refers to a layer made of metal, specifically a foil with a microlevel thickness. By using a metal foil as the conductive layer, the conductive laminate of this invention can provide higher electromagnetic wave shielding compared to graphite sheets, metal vapor-deposited films, etc.

[0025] There are no particular limitations on the metal foil as long as it is made of the desired metallic material, such as copper foil, aluminum foil, nickel foil, and stainless steel foil. Among these, copper foil is the most preferred from the viewpoint of excellent conductivity and electromagnetic wave shielding properties.

[0026] In addition, the copper foil can be electrolytic copper foil or rolled copper foil. Among them, when it is bonded to the adhesive layer or adhesive layer of the conductive layer, or made into a conductive adhesive tape as described later, the adhesion to the adhesive layer disposed on the side opposite to the colored film layer side (the second main surface) of the conductive layer is excellent, so electrolytic copper foil is the best.

[0027] The thickness of the conductive layer is not particularly limited, but it is preferably 3 μm or more, more preferably 5 μm or more, and more preferably 40 μm or less, more preferably 20 μm or less. More specifically, the thickness of the conductive layer is preferably 3 μm or more and 40 μm or less, more preferably 5 μm or more and 20 μm or less. By setting the thickness of the conductive layer within the above range, good conductivity can be achieved even with a small total thickness of the conductive laminate. It should be noted that if the thickness of the conductive layer exceeds the above range, it may become difficult to achieve a thinner conductive laminate; conversely, if the above range is not met, it may be difficult to obtain both conductivity and electromagnetic wave shielding.

[0028] The ten-point average surface roughness Rz of the conductive layer is preferably 2.0 μm or less. This is because by ensuring the surface roughness Rz of the conductive layer is within the aforementioned range, when an adhesive layer or bonding agent layer is formed to adhere to the conductive layer, or a conductive adhesive tape described later is formed, the adhesive properties of the conductive adhesive layer or insulating adhesive layer adhering to the film on the second main surface of the conductive layer can be fully utilized. More preferably, the ten-point average surface roughness Rz of the conductive layer is 0.01 μm or more, 0.1 μm or more, and furthermore, Rz is 2.0 μm or less, 1.5 μm or less, 1.3 μm or less, 1.1 μm or less, or 0.9 μm or less.

[0029] Furthermore, the arithmetic mean roughness Ra of the conductive layer is preferably 0.01 μm or more and 1.0 μm or less, more preferably 0.01 μm or more and 0.7 μm or less, and even more preferably 0.05 μm or more and 0.3 μm or less. By making the arithmetic mean roughness Ra of the conductive layer within the above range, when an adhesive layer or bonding agent layer, or a conductive adhesive tape described later, is formed that adheres to the conductive layer, the adhesive layer of the film adhered to the side of the conductive layer opposite to the colored film layer side (the second main surface) can fully exert its adhesiveness.

[0030] The ten-point average surface roughness Rz and arithmetic mean roughness Ra of the conductive layer refer to the values ​​specified in JIS B0601:2013. Using a HANDYSURF+ manufactured by Tokyo Seimitsu Corporation, surface measurements are performed at any three points on the surface of the conductive layer (each measuring 50 μm in length × 50 μm in width), and the average value of the three measured points is taken as the ten-point average surface roughness Rz and arithmetic mean roughness Ra of the conductive layer.

[0031] 2. Adhesive layer or bonding agent layer In this invention, the adhesive or bonding agent layer is disposed between the conductive layer and the colored film layer, bonding the conductive layer and the colored film layer together. It can be either an adhesive layer or a bonding agent layer. It should be noted that sometimes the adhesive or bonding agent layer that bonds the conductive layer and the colored film layer is referred to as a bonding layer.

[0032] When the bonding layer is an adhesive layer, there are no particular limitations on the composition of the adhesive layer. For example, well-known adhesive compositions such as (meth)acrylic adhesive compositions, polyester adhesive compositions, styrene-diene block copolymer adhesives, vinyl alkyl ether adhesive compositions, polyamide adhesive compositions, fluorinated adhesive compositions, creep-modified adhesive compositions, and radiation-cured adhesive compositions can be appropriately selected. Two or more adhesive components can be used alone or in combination.

[0033] Furthermore, when the bonding layer is an adhesive layer, the composition of the adhesive layer is not particularly limited. For example, commonly used adhesives such as vinyl acetate resin-based adhesives, ethylene-vinyl acetate copolymer (EVA) adhesives, α-olefin (isobutylene-maleic anhydride resin) adhesives, acrylic resin-based adhesives, styrene-butadiene rubber-based adhesives, vinyl chloride resin-based adhesives, chloroprene rubber-based adhesives, nitrile rubber-based adhesives, reclaimed rubber-based adhesives, SBR adhesives, urethane resin-based adhesives, silicone resin-based adhesives, modified silicone resin-based adhesives, epoxy-modified silicone resin-based adhesives, epoxy adhesives, and silylated urethane resin-based adhesives can be used alone or in combination. Two or more adhesive components can be used individually or in combination.

[0034] In order to improve the adhesion between the colored film layer and the conductive layer, the bonding layer is preferably an adhesive layer. For high adhesion reliability, it is more preferable that the adhesive layer contains a (meth)acrylic adhesive composition as an adhesive component. The (meth)acrylic adhesive composition must contain a (meth)acrylic polymer (acrylic copolymer) as a base polymer, and may contain suitable additives such as crosslinking agents, tackifiers, softeners, plasticizers, fillers, anti-aging agents, and colorants as needed.

[0035] (Meth)acrylate polymers are polymers with alkyl (meth)acrylate monomers as the main component, and are prepared by using monomers (copolymeric monomers) that can copolymerize with (meth)alkyl esters as needed. That is, acrylic polymers can be homopolymers or copolymers.

[0036] Examples of alkyl methacrylates constituting methacrylic polymers include methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, isooctyl methacrylate, nonyl methacrylate, and isopropyl methacrylate. Nonyl acrylate, decyl acrylate, isodecyl acrylate, undecyl acrylate, dodecyl acrylate, tridecyl acrylate, tetradecyl acrylate, pentadecyl acrylate, hexadecyl acrylate, heptadecanyl acrylate, octadecyl acrylate, nonadecanyl acrylate, eicosyl acrylate, and other C1-20 alkyl methacrylates [preferably C4-18 alkyl (straight-chain or branched-chain) methacrylates]. Alkyl methacrylates can be appropriately selected based on the desired adhesion, etc. Alkyl methacrylates can be used alone or in combination of two or more. Butyl acrylates containing 30% or more have excellent adhesion and heat resistance, and are therefore preferred.

[0037] In addition, examples of comonomers capable of copolymerizing with the aforementioned (meth)alkyl esters include carboxyl-containing monomers or their anhydrides such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid; sulfonic acid-containing monomers such as sodium vinyl sulfonate; aromatic vinyl compounds such as styrene and substituted styrene; cyano-containing monomers such as acrylonitrile; olefins such as ethylene, propylene, and butadiene; vinyl esters such as vinyl acetate; vinyl chloride; amide-containing monomers such as acrylamide, methacrylamide, N-vinylpyrrolidone, and N,N-dimethyl(meth)acrylamide; hydroxyl-containing monomers such as (meth)acrylate hydroxyalkyl ester and glycerol dimethacrylate; and amino-containing monomers such as (meth)acrylate aminoethyl ester and (meth)acryloylmorpholine. The copolymer includes monomers containing imide groups such as cyclohexylmaleimide and isopropylmaleimide; epoxy-containing monomers such as glycidyl methacrylate and methyl glycidyl methacrylate; isocyanate-containing monomers such as 2-methacryloyloxyethyl isocyanate; and multifunctional copolymer monomers such as triethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and divinylbenzene. A single copolymer monomer or a combination of two or more monomers can be used. Modifying monomers with functional groups such as carboxyl groups are preferred as copolymer monomers. When it contains 0.5% to 4.0% acrylic acid, it exhibits excellent adhesion and heat resistance, and is therefore preferred.

[0038] The weight-average molecular weight (Mw) of the (meth)acrylic polymer is preferably 300,000 or more, 500,000 or more, or 600,000 or more. Furthermore, the aforementioned weight-average molecular weight (Mw) is preferably 1,200,000 or less, 1,000,000 or less, or 900,000 or less. More specifically, the weight-average molecular weight (Mw) of the (meth)acrylic polymer is preferably in the range of 300,000 to 1,200,000, more preferably in the range of 500,000 to 1,000,000, and even more preferably in the range of 600,000 to 900,000. By ensuring that the weight-average molecular weight (Mw) of the (meth)acrylic polymer is within the above range, the aforementioned black adhesive layer, even with a thin thickness, can exhibit good adhesion and heat resistance to the conductive layer and the insulating portion.

[0039] Weight-average molecular weight (Mw) can be determined by gel permeation chromatography (GPC). More specifically, the GPC measuring apparatus can be the "SC8020" manufactured by Tosoh Corporation, and the value can be obtained by measuring under the following GPC measuring conditions using polystyrene conversion. (GPC determination conditions) • Sample concentration: 0.5% by weight (tetrahydrofuran solution) • Sample injection volume: 100 μL • Eluent: Tetrahydrofuran (THF) • Flow rate: 1.0 mL / min • Column temperature (measurement temperature): 40℃ • Pillar: "TSKgel GMHHR-H" manufactured by Tosoh Corporation • Detector: Differential Refraction

[0040] It should be noted that, unless otherwise specified, the weight-average molecular weight (Mw) in this specification is the value obtained by measuring under the methods and conditions described above.

[0041] To improve adhesion, the adhesive layer preferably contains a tackifying resin. By including a tackifying resin in the adhesive layer, tensile strength and tensile breaking strength can be improved. Therefore, by appropriately adding a tackifying resin according to the (meth)acrylic polymer used, the tensile strength and tensile breaking strength of the conductive laminate of the present invention can be adjusted. Examples of tackifying resins include rosin-based resins such as rosin and rosin ester compounds; terpene-based resins such as diterpene polymers and α-pinene-phenol copolymers; petroleum resins such as aliphatic (C5) and aromatic (C9) resins; and styrene-based resins, phenolic resins, xylene resins, etc. One tackifying resin may be used alone, or two or more may be used in combination.

[0042] In cases where the adhesive layer comprises a (meth)acrylic polymer with n-butyl (meth)acrylic acid (in other words, n-butyl (meth)acrylate) as the main monomer component, it is preferable to mix in a rosin-based resin and a styrene-based resin. This is because by using both of these tackifying resins together, it is easier to achieve a balance between thinness and adhesion of the adhesive layer.

[0043] To improve initial adhesion, the adhesive layer preferably comprises a tackifying resin that is liquid at room temperature. Examples of tackifying resins that are liquid at room temperature include liquid resins that are solid at room temperature, processing oils, polyester plasticizers, and low molecular weight liquid rubbers such as polybutene. Terpene phenolic resins are particularly preferred. Commercially available examples include YP-90L manufactured by Yasuhara Chemical Co., Ltd. The amount of tackifying resin added is preferably 1 to 20 parts by weight relative to 100 parts by weight of the (meth)acrylic polymer.

[0044] The tackifying resin is preferably contained in the range of 10 to 70 parts by weight relative to 100 parts by weight of the (meth)acrylic polymer, and more preferably in the range of 20 to 60 parts by weight. By setting the amount of tackifying resin within the above range, the adhesive strength of the adhesive layer can be improved.

[0045] There is no particular limitation on the gel content of the adhesive layer, but it is preferably in the range of 5% to 95% by mass. This is because even if the adhesive layer is thin, it is easy to exhibit sufficient adhesion. More preferably, the gel content of the adhesive layer is in the range of 10% to 70% by mass, and even more preferably in the range of 15% to 50% by mass.

[0046] The gel fraction is the mass of the dried insoluble component remaining after the cured adhesive layer is immersed in toluene and left for 24 hours, expressed as a percentage relative to the original mass. Gel fraction (mass%) = [(mass of the adhesive layer after toluene impregnation) / (mass of the adhesive layer before toluene impregnation)] × 100

[0047] The energy storage modulus of the adhesive layer at 25°C is preferably 1×10⁻⁶. 4 Above and 5×10 5 Pa or less, more preferably 3×10 Pa 4 Above and 1×10 5 The reason is that by setting the storage modulus of the adhesive layer to the above range, even for thin films, it is easy to achieve a high balance between wettability (initial tack), adhesion, and processability.

[0048] The storage modulus of the adhesive layer at 25°C can be determined using a viscoelastic testing machine. More specifically, the viscoelastic testing machine can be a viscoelastic testing machine (ARES 2kSTD) manufactured by TA Instruments Japan, and the result can be determined under the following test conditions. • Test piece thickness: 2mm • Frequency: 1Hz • Compression load: 40~60g

[0049] It should be noted that, unless otherwise specified, the storage modulus of the adhesive layer at 25°C in this specification is the value obtained by measuring using the methods and conditions described above.

[0050] (Meth)acrylic acid polymers can be prepared using conventional polymerization methods such as solution polymerization, emulsion polymerization, and ultraviolet irradiation polymerization.

[0051] The adhesive layer or binder layer can be colorless and transparent or colored. From the viewpoint of further improving the designability of the conductive laminate, it is preferable to be colored, especially dark-colored, and more preferably black. By making the adhesive layer or binder colored, particularly black, even in thin conductive laminates, the synergistic effect of the color presented by the coloring layer and the color presented by the adhesive layer or binder layer can achieve high designability and concealment. In addition, in order to achieve designability and concealment through the coloring layer monomers, it is necessary to thicken the coloring layer. In contrast, by making the adhesive layer or binder layer colored, the increase in the overall thickness of the conductive laminate that accompanies the improvement in designability and concealment can be suppressed.

[0052] When the adhesive layer or binder layer is colored, the adhesive layer or binder layer contains a colorant. There are no particular limitations on the colorant; pigments, dyes, etc., can be used. When the adhesive layer or binder layer is black, examples of black colorants included in the adhesive layer or binder layer include organic black pigments, inorganic black pigments, and black dyes. One type of black colorant can be used alone, or two or more can be used in combination. Furthermore, the black colorant preferably has low insulation or conductivity. This is because it can reduce the conductivity of the adhesive layer or binder layer and improve the surface insulation of the conductive laminate.

[0053] Examples of inorganic black pigments include carbon black (furnace black, channel black, acetylene black, pyrolytic black, lampblack, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, anthocyanin black, activated carbon, ferrite, magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complexes, and composite oxide black pigments. Examples of organic black pigments include aniline black, azo pigments, and anthraquinone organic black pigments. Among these, carbon black is preferred because its color readily blends with the colors of components used in electrical and electronic equipment, it exhibits excellent opacity and dispersibility, and it provides high concealment, particularly due to its ability to effectively represent the overlap between the black coloring layer and the adhesive or binder layer.

[0054] The content of colorant in the adhesive layer or bonding agent layer is not particularly limited, and can be set to an amount that enables the desired surface design and concealment through overlap with the coloring layer. For example, in the total amount (100% by mass) of the adhesive layer or bonding agent layer, it is preferably 1% by mass or more and 50% by mass or less, more preferably 4% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 35% by mass or less. By keeping the content of colorant in the adhesive layer or bonding agent layer within the above range, even with a thin thickness, the insulating properties of the adhesive layer or bonding agent layer and its adhesion to the coloring film layer and conductive layer can be achieved, thereby improving the surface design and concealment resulting from the overlap with the coloring layer.

[0055] The thickness of the adhesive layer or binder layer is preferably 0.5 μm or more, 1 μm or more, or 1.5 μm or more, and more preferably 5 μm or less, 3 μm or less, or 2.5 μm or less. More specifically, the thickness of the adhesive layer or binder layer is preferably 0.5 μm or more and 5 μm or less, preferably 1 μm or more and 3 μm or less, and most preferably 1.5 μm or more and 2.5 μm or less. This is because by setting the thickness of the adhesive layer or binder layer within the above range, it is easy to balance the adhesive strength and thinness of the conductive laminate. In particular, when the conductive laminate of the present invention is used as electromagnetic wave shielding for electronic components, it is easy to balance the required adhesive strength and thinness. In addition, when the adhesive layer or binder layer contains a colorant, the concentration of color in the adhesive layer or binder layer monomers is increased, which can improve the surface design and concealment resulting from the overlap with the coloring layer.

[0056] The adhesive layer or bonding agent layer preferably has low conductivity or exhibits insulating properties. This is because reducing the conductivity of the adhesive layer or bonding agent layer improves the insulation of the surface of the colored film layer side of the conductive laminate. Specifically, the surface resistivity of the adhesive layer or bonding agent layer is preferably 1 × 10⁻⁶. 9 Ω / □ or higher, further preferred is 1×10 10 Ω / □ or higher, more preferably 1×10 11 Ω / □ or higher. By making the surface resistivity of the adhesive layer or binder layer within the above range, the adhesive layer or binder layer can exhibit high insulation properties, and the insulation properties provided by the coloring film layer can be further improved. Therefore, the conductive laminate of the present invention can exhibit higher insulation properties on the surface of the coloring film layer side. It should be noted that the higher the surface resistivity of the adhesive layer or binder layer, the better; typically, it can be set to 1 × 10⁻⁶. 18 Ω / □ or less, 1×10 16 Ω / □ or less, 1×10 14 Ω / □ or less, 1×10 12 Below Ω / □.

[0057] The surface resistivity of the adhesive layer or bonding agent layer refers to the value measured according to JIS-K6911. It can be measured by applying a voltage of 500V to the adhesive layer or bonding agent layer using a resistivity meter (ADVANTEST digital ultra-high resistance / micro current meter R8340, TR42BOX).

[0058] When the adhesive layer or binder layer is colored, the opacity of the adhesive layer or binder layer is not particularly limited as long as the desired surface colorability can be achieved through overlap with the coloring layer described later. It is preferably 20% or more, more preferably 30% or more, and more preferably 40% or more. Furthermore, the higher the opacity of the adhesive layer or binder layer, the more preferred it is, and its upper limit can be set to 100%. The reason is that by setting the opacity of the adhesive layer or binder layer to the above range, the reduction in the design and opacity of the surface of the colored film layer of the conductive laminate caused by the influence of the hue of the conductive layer can be suppressed. In particular, when a black ink layer is used as the coloring layer, the reduction in the blackness and opacity of the conductive laminate surface caused by the influence of the hue of the conductive layer can be suppressed.

[0059] The concealment rate of the adhesive layer or bonding agent layer can be determined by the following method. The adhesive layer or bonding agent layer is attached to the white and black sides of concealment rate test paper (manufactured by TESTPANEL Industries, Japan). Using the color determination method specified in JIS-Z-8722, the Y value representing luminance among the tristimulus values ​​of the adhesive layer or bonding agent layer attached to the white and black sides is measured respectively. Using a colorimeter "CM-3500d" (manufactured by Minolta), the standard light C in a 2-degree field of view is measured. The concealment rate can be determined by substituting the measured Y value into the following formula. Concealment rate (%) = (Y value of adhesive layer or bonding agent layer attached to the black side / Y value of adhesive layer or bonding agent layer attached to the white side) × 100%

[0060] An adhesive layer or bonding agent layer can be formed by applying an adhesive or bonding agent to a resin film layer of a conductive layer or a colored film layer. Examples of coating methods include gravure coating, comma coating, rod coating, mold coating, lip coating, and screen coating. Among these, gravure coating is preferred for coating thin films, and microgravure coating is most preferred.

[0061] 3. Colored film layer The coloring film layer in this invention is a layer disposed on one side (first main surface) of the conductive layer, separated by an adhesive layer or bonding agent layer. The coloring film layer of this invention comprises a resin film layer and a coloring layer disposed in contact with the surface of the resin film layer opposite to at least the conductive layer. That is, in the coloring film layer, the coloring layer is formed directly on the surface of the resin film layer opposite to at least the conductive layer without any other layers in between. The coloring layer in the coloring film layer comprises a cured resin and a coloring material, and the glass transition temperature of the coloring layer is within a specified range.

[0062] The conductive laminate of the present invention, by having a colored film layer with the above-described characteristics on its outermost surface, enables the surface of the colored film layer to exhibit good alcohol resistance. Furthermore, by having the colored film layer have a laminated structure of a resin film layer and a colored layer, the design flexibility and concealment provided by the colored layer are evident, and even in a thin form, the colored film layer as a whole exhibits good insulation properties.

[0063] The coloring layer can be directly disposed on the surface of the resin film layer opposite to at least the conductive layer, or the coloring layer can be directly disposed on both sides of the resin film layer. That is, the coloring layer can have a first coloring layer in contact with the surface of the resin film layer opposite to the conductive layer (hereinafter referred to as the first surface of the resin film layer) and a second coloring layer in contact with the surface of the conductive layer (hereinafter referred to as the second surface of the resin film layer).

[0064] Furthermore, in the coloring film layer, the coloring layer disposed on the first side of the resin film layer can be a single layer, or it can be a multilayer structure with two or more layers, such as through multicolor printing. The same applies to the second side of the resin film layer. When the coloring layer is a multilayer structure, the layers constituting the multilayer structure are directly in contact and stacked without being separated by other layers.

[0065] (1) Resin film layer The resin film layer constituting the colored film layer in this invention is not particularly limited, and known resin films exhibiting insulating properties can be cited. Specifically, polyester films, polyimide films, polyamide films, polyurethane films, and polyolefin films can be cited. Among these, polyester films or polyimide films are preferred from the perspective of thinness while maintaining insulation and being resistant to breakage and easy to exert strength, and polyester films are particularly preferred from the perspective of being able to be further thinned and having excellent insulation properties.

[0066] The thickness of the resin film layer is not particularly limited as long as it achieves the desired insulation performance, but is preferably 1 μm or more, 1.5 μm or more, or 2 μm or more. Furthermore, the aforementioned thickness is preferably 16 μm or less, 13 μm or less, 6 μm or less, 4.5 μm or less, 3 μm or less, or 2.5 μm or less. More specifically, the thickness of the resin film layer is preferably 1 μm or more and 13 μm or less, further preferably 1 μm or more and 6 μm or less, and most preferably 1.5 μm or more and 2.5 μm or less. By keeping the resin film layer thickness within the above range, high insulation performance is easily achieved. Furthermore, by keeping the resin film layer thickness within the above range, the thickness of the coloring film layer and the total thickness of the conductive laminate can be reduced, resulting in improved alcohol resistance, surface insulation, and productivity, as well as the ability to achieve a thinner conductive laminate.

[0067] To improve adhesion to the coloring layer, the resin film layer can undergo an easy-bonding treatment. There are no particular limitations on the type of easy-bonding treatment; known treatments can be applied, such as surface treatments like corona treatment or a primer coating.

[0068] (2) Coloring layer The coloring layer constituting the coloring film layer in this invention is a layer comprising a cured resin and a coloring material, and having a glass transition temperature within a specified range. The coloring layer is in direct contact with the surface of the resin film layer. In the conductive laminate of this invention, the coloring layer disposed on the surface of the resin film layer opposite to the conductive layer side can typically be located on the outermost surface of the surface of the colored film side of the conductive laminate.

[0069] The glass transition temperature of the coloring layer in this invention is in the range of 43°C to 70°C. By keeping the glass transition temperature of the coloring layer within the above-specified range, good alcohol resistance and surface insulation can be achieved. Furthermore, when the coloring film layer is bonded to the conductive layer through an adhesive layer or bonding agent layer, wrinkles and other defects caused by curling of the coloring film layer can be suppressed, thereby improving productivity.

[0070] It should be noted that, in order to improve the alcohol resistance of the surface, when a colored layer is formed by printing a coloring ink containing a high-hardness resin onto a thin resin film, there is a tendency to insufficient adhesion between the colored layer and the resin film, and interlayer delamination easily occurs between the resin layer and the resin film layer. However, according to the present invention, by setting a predetermined glass transition temperature instead of increasing the hardness of the resin in the colored layer formed on the resin film layer, the adhesion between the resin film layer and the colored layer can be improved while simultaneously improving alcohol resistance. Therefore, a conductive laminate with high interlayer adhesion can be produced.

[0071] The glass transition temperature of the coloring layer only needs to be within the range of 43°C to 70°C, and preferably within the range of 45°C to 68°C, particularly preferably within the range of 50°C to 65°C. This is because, by further improving alcohol resistance and by coating the coloring ink onto a thin resin film layer during the formation of the coloring film, the curling of the coloring film can be more effectively suppressed, further improving the productivity of the conductive laminate, and achieving a better balance between alcohol resistance and productivity. Furthermore, the above manufacturing method allows for the thinning of the coloring film layer, thus enabling the conductive laminate to be thinner as well. The glass transition temperature was measured using DSC according to ISO 3146.

[0072] The glass transition temperature of the coloring layer can be adjusted by the glass transition temperature of the resin curing agent contained in the coloring layer and the mixing ratio of the resin curing agent and the coloring material. Among these factors, the glass transition temperature of the resin curing agent is very helpful to the glass transition temperature of the coloring layer, so it can be mainly adjusted by the glass transition temperature of the resin curing agent.

[0073] <Composition of the coloring layer> The coloring layer comprises a cured resin and a coloring material. For example, the coloring layer can be formed by applying a coloring ink comprising a two-component curable resin and a coloring material to one side of a resin film and allowing it to dry. The two-component curable resin comprises a base agent and a curing agent. The coloring layer is the layer formed by the cured product of the coloring ink, and the cured product of the two-component curable resin comprising the base agent and the curing agent corresponds to the cured resin in the coloring layer.

[0074] -Cureable Resin- The cured resin contained in the aforementioned coloring layer can be any resin capable of setting the glass transition temperature of the coloring layer within a specified range. The glass transition temperature of the cured resin is preferably in the range of 43°C to 70°C, more preferably in the range of 45°C to 68°C, and particularly preferably in the range of 50°C to 65°C. The glass transition temperature is a value obtained by measuring using DSC according to ISO 3146. The glass transition temperature of the cured resin can be appropriately adjusted, for example, by adjusting the mixing ratio of the precursor of the cured resin (i.e., the two-component curing resin) to the curing agent and the degree of crosslinking. There are no particular limitations on the cured resin as long as it exhibits insulation properties and its glass transition temperature falls within the aforementioned range; cured resins of general-purpose resins can be used, such as cured polyester resins. Specifically, the cured resin is a cured resin composition comprising a polyol component mainly composed of a polyester polyol and an isocyanate component mainly composed of a polyfunctional isocyanate. The reason for using a cured polyester resin containing the aforementioned polyol component and isocyanate component is that, by combining the coloring layer and resin film layer, it is possible to achieve good alcohol resistance, surface insulation, and improved conductivity in the production of laminates. Furthermore, the reason for this is that the coloring layer containing the above-mentioned cured resin component exhibits particularly good adhesion to the resin film layer containing the cured polyester resin component. It should be noted that the main component refers to the component with the highest content among the contained components. For example, a polyol component with polyester polyol as the main component means that the polyester polyol content is the highest among the polyol components. The same applies to isocyanate components with polyfunctional isocyanates as the main component. The cured resin is a reaction cured product of the polyol component and the isocyanate component, preferably a cured polyester resin with polyester polyol as the polyol component and polyfunctional isocyanate as the isocyanate component.

[0075] When the resin cured product of the coloring layer is a cured product of a resin composition comprising a polyol component mainly composed of polyester polyol and an isocyanate component mainly composed of polyfunctional isocyanate, the coloring layer can be formed by the following method: using a polyol component mainly composed of polyester polyol as the main agent, using an isocyanate component mainly composed of polyfunctional isocyanate as the curing agent, and using a coloring ink comprising a two-component curing resin and a coloring material, wherein the two-component curing resin comprises the main agent and the curing agent.

[0076] (Polyol components) When the coloring layer comprises a cured resin composition containing a polyol component mainly composed of polyester polyol and an isocyanate component mainly composed of polyfunctional isocyanate, the molecular weight of the polyester polyol component is not particularly limited, but the mass-average molecular weight is preferably in the range of 1,000 to 400,000. If the mass-average molecular weight of the polyester polyol is 1,000 or more, the printability, coating compatibility, and alcohol resistance of the resulting cured resin are easily suitable; by setting it to 400,000 or less, drying properties and anti-blocking properties are easily improved. The mass-average molecular weight of the polyester polyol is further preferably in the range of 2,000 to 350,000, and more preferably in the range of 3,000 to 300,000.

[0077] The mass-average molecular weights mentioned above are based on standard polystyrene obtained by gel permeation chromatography (GPC). As for the determination conditions, a TSKgel GMHXL column [manufactured by Tosoh] was used, the column temperature was 40°C, the eluent was tetrahydrofuran, the flow rate was 1.0 mL / min, and TSK standard polystyrene was used as the standard.

[0078] Polyester polyols are compounds having two or more hydroxyl groups. Examples of polyester polyols include those obtained by reacting one or more polyacids with one or more polyols, those obtained by ring-opening polymerization of cyclic ester compounds such as ε-caprolactone, and those obtained by copolymerizing them.

[0079] As polyacids used in the preparation of polyester polyols, known raw materials can be used. For example, the following polyacids, or mixtures of two or more of the following polyacids, can be used alone: ​​succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalenedicarboxylic acid, biphenyl dicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, and the anhydrides or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and the ester-forming derivatives of these dihydroxycarboxylic acids, dimer acids, and other polyacids. The aforementioned dimer acids refer to various substances, including those obtained by the Diels-Alder type dimerization reaction of C18 unsaturated fatty acids such as oleic acid and linoleic acid, and commercially available substances obtained by adding hydrogen to unsaturated bonds to saturate them. A representative dimer acid is composed of 0-5% by mass of C18 monocarboxylic acids, 70-98% by mass of C36 dimer acids, and 0-30% by mass of C54 trimeric acids.

[0080] The polyols used to prepare polyester polyols can all be made from known raw materials. Specific examples of polyols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-10-pentanediol, 1,6-hexanediol, neopentanediol, methylpentanediol, dimethylbutanediol, butyl ethyl propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dihydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanediol, triethylene glycol, polycaprolactone diol, dimer diol, bisphenol A, hydrogenated bisphenol A, and other diols; propiolactone, butyrolactone, ε-caprolactone, etc. Polyesters obtained through ring-opening polymerization of cyclic ester compounds such as δ-valerolactone and β-methyl-δ-valerolactone; and polyethers obtained through addition polymerization of one or more compounds with two active hydrogen atoms, such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene ethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol, with one or more monomers, such as ethylene oxide, propylene oxide, butane oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, and cyclohexanediol. These polyols can be used alone or in mixtures of two or more.

[0081] The polyol component can contain polyester polyol as the main component, or it can contain only polyester polyol. As long as the glass transition temperature of the coloring layer can be set within the specified range, it can contain one or more polyols other than polyester polyol.

[0082] (Isocyanate component) In the case where the coloring layer comprises a cured resin composition containing a polyol component mainly composed of polyester polyol and an isocyanate component mainly composed of polyfunctional isocyanate, the isocyanate component is a component that reacts with the aforementioned polyol component mainly composed of polyester polyol, and is mainly composed of polyfunctional isocyanate.

[0083] Polyfunctional isocyanates are simply those having two or more isocyanate groups in one molecule; diisocyanates having two isocyanate groups are preferred. Examples of polyfunctional isocyanates include aromatic diisocyanates (diphenylmethane diisocyanate, phenyl diisocyanate, tetramethylphenyl diisocyanate, benzylene diisocyanate, low molecular weight diols and prepolymers of the above aromatic diisocyanates, etc.) and aliphatic diisocyanates (1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, ethylene glycol, propylene glycol and other low molecular weight diols and aliphatic diisocyanates, etc.). Prepolymers of diisocyanates, alicyclic diisocyanates (isophorone diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, methylcyclohexylene diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, low molecular weight diols and prepolymers of the above alicyclic diisocyanates, etc.), and mixtures of two or more thereof, adducts of the above diisocyanates with polyols, and isocyanurate esters, biuret esters, and ureocarbamate esters of the above diisocyanates, etc. Among these, alicyclic or alicyclic diisocyanates, their adducts, isocyanurate esters, biuret esters, or ureocarbamate esters exhibit less curling due to curing shrinkage, making them suitable for use in films.

[0084] The isocyanate component can contain one or more polyfunctional isocyanates. In addition, as long as the isocyanate component contains a polyfunctional isocyanate as the main component, it can also contain other isocyanates as long as it can keep the glass transition temperature of the colored layer within the specified range.

[0085] The glass transition temperature of the cured resin can be achieved by appropriately combining the polyol and isocyanate components in their respective proportions. The proportion of the polyol component (main agent), which is mainly composed of polyester polyol, and the isocyanate component (curing agent), which is mainly composed of polyfunctional isocyanate, can be appropriately adjusted according to the hydroxyl value of the main component of the main agent, namely the polyester polyol, and the number of isocyanate groups in the polyfunctional isocyanate. For example, it is preferable to combine the components in such a way that the ratio of hydroxyl groups in the polyol component to the isocyanate groups in the isocyanate component (hydroxyl / isocyanate group) is 1 / 0.5 to 1 / 10 (equivalent ratio), and more preferably 1 / 0.6 to 1 / 5.

[0086] (other) The content of the cured resin in the coloring layer can be adjusted appropriately according to the intended use, and is preferably 30-90% by mass, more preferably 40-80% by mass, and more preferably 50-65% by mass. This is because it allows the glass transition temperature to remain within a specified range, resulting in good alcohol resistance. It should be noted that the content in the coloring layer is synonymous with the content in the solid components of the coloring ink that forms the coloring layer. Furthermore, the cured resin in the coloring layer can be one type or can contain two or more types.

[0087] -Coloring Materials- As a coloring material, halogen-free, commonly known pigments and dyes can be used, and the appropriate selection can be made according to the color of the colored layer. For example, considering weather resistance, heat resistance, and dispersibility with ink resins, in the case of black, the black colorant described in the above-mentioned adhesive layer or binder layer section is preferred, with carbon black being the most preferred; in the case of white, titanium oxide, calcium carbonate, and barium sulfate are preferred; in the case of yellow, iron oxide yellow is preferred; in the case of red, iron oxide red is preferred; in the case of blue, phthalocyanine blue is preferred; in the case of silver, aluminum powder is preferred; and in the case of pearlescent, mica titanium powder is preferred. Among these, carbon black is preferred because it easily makes the color of the conductive laminate the same as the color of the components used in electrical and electronic equipment, and has excellent concealment properties.

[0088] The amount of coloring material added can be adjusted appropriately according to the intended use, and it is preferably contained in the coloring layer in the range of 10 to 70% by mass. The content of coloring material in the coloring layer is more preferably in the range of 20 to 60% by mass, and even more preferably in the range of 35 to 50% by mass. If it is 10% by mass or more, suitable concealment can be achieved; if it is 70% by mass or less, suitable dispersibility and adhesion to the resin film can be achieved. It should be noted that the content in the coloring layer is synonymous with the content in the solid components of the coloring ink that forms the coloring layer.

[0089] -Any ingredient- The coloring layer and the coloring ink forming the coloring layer may contain any materials. Examples of such materials include commonly used ink additives such as dispersants such as cellulose resins, blocking agents, and crosslinking accelerators such as dibutyltin.

[0090] Furthermore, the coloring layer may contain resins other than the aforementioned cured resin, without impairing the effects of the present invention. Of the resins other than the coloring material contained in the coloring layer, the proportion of cured resin is preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably substantially free of resins other than the aforementioned cured resin.

[0091] <Composition of Coloring Layers> The thickness of the coloring layer is not particularly limited, but is preferably in the range of 1.0 to 4.0 μm, more preferably in the range of 1.5 to 3.5 μm, and even more preferably in the range of 2.0 to 3.0 μm. By making the thickness 1 μm or more, suitable design flexibility can be achieved due to the coloring layer. Furthermore, the coloring layer can also firmly adhere to thin resin films that are difficult to bond with corona treatment or other easily adhesive processes, thus improving the interlayer adhesion between the coloring film layer and the conductive laminate as a whole. On the other hand, by making the thickness 4 μm or less, the curling of the coloring film layer can be more effectively suppressed, further improving the productivity of the conductive laminate. In addition, the conductive laminate of the present invention, besides improving alcohol resistance, surface insulation, and productivity, can also achieve thinner profiles. When the coloring layer is a multilayer, the thickness of the coloring layer refers to the total thickness of the multilayer.

[0092] The pencil hardness of the coloring layer is preferably HB to 2H, and more preferably F to H. Setting it to HB or higher achieves suitable alcohol resistance, while setting it to 2H or lower suppresses curling of the coloring film layer, thus improving the productivity of the conductive laminate. Furthermore, it improves the adhesion between the coloring layer and the resin film layer, resulting in better interlayer adhesion of the conductive laminate as a whole. The hardness of the coloring layer can be measured based on the scratch hardness (pencil method) according to JIS K5600.

[0093] When the coloring layer is a multilayer body, the composition of each layer constituting the multilayer body can be the same or different, as long as each layer can exhibit the glass transition temperature specified above. The cured resin contained in each layer preferably exhibits the glass transition temperature specified above.

[0094] (3) Arbitrary composition In addition to the aforementioned coloring layer and resin film layer, the coloring film layer may also include a matte layer in its configuration. The matte layer is typically disposed on the surface of the coloring layer, which is located on the side of the resin film layer opposite to the conductive layer (the first side of the resin film layer). In other words, when the coloring film layer includes a matte layer in its configuration, the coloring film layer can be formed by sequentially stacking at least a matte layer, a coloring layer, and a resin film layer, with the matte layer located on the outermost surface of the surface of the conductive laminate on the coloring film side. It should be noted that when the matte layer is disposed on the coloring layer, the matte layer is disposed directly in contact with the surface of the coloring layer without any other layers in between.

[0095] By providing a matte layer on the surface of the colored film layer opposite to the conductive layer side of the resin film layer, in addition to ensuring good alcohol resistance and surface insulation on one side of the colored film layer, the brightness L of the colored film layer can also be adjusted. * chromaticity a * and chromaticity b *The properties of the conductive laminate, including its gloss level of 60°, enhance the overall design and concealment of the conductive laminate. A matte layer is particularly preferred for adjusting the gloss level of 60°.

[0096] In this invention, the matte layer exhibits a glass transition temperature within a specified range. The glass transition temperature of the matte layer is in the same range as that of the aforementioned colored layer, which can be in the range of 43°C to 70°C, preferably 45°C to 68°C, and more preferably 50°C to 65°C. This improves the alcohol resistance of the matte layer. The glass transition temperature is a value determined using DSC according to ISO 3146.

[0097] The matte layer is a layer comprising a resin binder and microparticles. Examples of microparticles include commonly used microparticles such as silica, calcium carbonate, and barium sulfate. Furthermore, the glass transition temperature of the matte layer is primarily determined by the glass transition temperature of the resin binder; therefore, a resin within the aforementioned specified glass transition temperature range can be appropriately selected from commonly used resins in matte layers as the resin binder. Preferably, the matte layer contains silica particles dispersed in a urethane-based resin.

[0098] The thickness of the matting layer is not particularly limited as long as it achieves the desired function, but is preferably 0.3 μm or more, 0.4 μm or more, or 0.5 μm or more. Furthermore, the thickness of the matting layer is only required to avoid significantly affecting the overall thickness of the conductive laminate, and is preferably 3 μm or less, 2 μm or less, or 1.5 μm or less. More specifically, the thickness of the matting layer is preferably 0.3 μm or more and 3 μm or less, and more preferably 0.5 μm or more and 1.5 μm or less.

[0099] The matte layer can be formed by applying a known surface treatment agent to the surface of the colored layer opposite to the resin film layer side, wherein the known surface treatment agent contains a matting agent (i.e., a matting agent) obtained by dispersing microparticles in a resin binder.

[0100] (3) Other The colored film layer in this invention can be formed by appropriately combining the above-mentioned resin film layer and the above-mentioned colored layer. The combination is not limited. The resin film layer is a polyester film, and the colored layer is a combination of layers containing a cured resin composition. In terms of further improving the adhesion between the resin film layer and the colored layer, and improving the interlayer adhesion within the colored film layer and the overall interlayer adhesion of the conductive laminate, it is more preferable that the above-mentioned resin composition contains a polyol component mainly composed of polyester polyol and an isocyanate component mainly composed of polyfunctional isocyanate.

[0101] The surface resistivity of the colored film layer in this invention is preferably 1×10⁻⁶. 9Ω / □ or higher, further preferably 1×10 10 Ω / □ or higher, more preferably 1×10 11 Ω / □ or higher. By maintaining the surface resistivity of the colored film layer within the above range, the conductive laminate of the present invention can maintain higher insulation on the surface of the colored film layer side. It should be noted that a higher surface resistivity of the colored film layer is better; typically, it can be set to 1×10⁻⁶. 18 Ω / □ or less, 1×10 16 Ω / □ or less, 1×10 14 Ω / □ or more, 1×10 12 Below Ω / □.

[0102] The surface resistivity of the colored film layer refers to the value measured according to JIS-K6911. It can be measured by applying a voltage of 500V to the colored film layer using a resistivity meter (ADVANTEST digital ultra-high resistance / micro current meter R8340, TR42BOX).

[0103] From the viewpoint of ensuring design feasibility, concealment, and light-blocking properties, the total light transmittance of the colored film in this invention is preferably 10% or less, more preferably 3% or less, and most preferably 1% or less. The total light transmittance is the total light transmittance Tt measured according to JIS K7105.

[0104] (4) Manufacturing method of coloring film layer The colored film layer can be obtained by dissolving and dispersing the aforementioned coloring material and a resin composition containing a precursor (i.e., a main agent and a curing agent) in an organic solvent using a coloring ink, and then printing it onto the surface of the resin film layer using a desired printing method, followed by drying to form the colored layer. Examples of printing methods for the coloring ink include known methods such as direct gravure printing, reverse gravure printing, and small-diameter gravure printing. Among these, direct gravure printing, which is less prone to damage even in thin resin film layers and has excellent printability, is preferred.

[0105] The organic solvent used to form the coloring layer of the coloring ink is not particularly limited, but an organic solvent without hydroxyl groups is preferred when dispersing the coloring material in the polyester polyol and for dilution. Known organic solvents can be used as non-hydroxyl-containing organic solvents. Examples include esters such as ethyl acetate, butyl acetate, and acetic acid solvent; ketones such as acetone, methyl ethyl ketone, isobutyl ketone, and cyclohexanone; ethers such as tetrahydrofuran and dioxane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as dichloromethane and dichloroethane; dimethyl sulfoxide; and dimethyl sulfonamide. Ethyl acetate and methyl ethyl ketone are preferred.

[0106] 4. Conductive laminate The total thickness of the conductive laminate of the present invention is preferably 6 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more. Furthermore, the total thickness is preferably less than 45 μm, more preferably less than 38 μm, and even more preferably less than 25 μm. More specifically, the total thickness of the conductive laminate of the present invention is preferably 10 μm or more and less than 45 μm, more preferably 15 μm or more and less than 45 μm, and even more preferably 15 μm or more and less than 25 μm. By setting the total thickness of the conductive laminate within the above range, a conductive laminate with a small total thickness and thin profile can be manufactured, exhibiting good alcohol resistance and surface insulation on the surface of the colored film layer side, as well as excellent productivity. Furthermore, while being thin, it is possible to balance various characteristics such as conductivity, electromagnetic wave shielding, interlayer adhesion, design feasibility, and concealment.

[0107] The conductive laminate of the present invention preferably has the above-described layer structure, wherein the surface of the colored film layer is composed of CIEL. * a * b * The colorimetric system specifies a brightness L. * chromaticity a * and chromaticity b * The specified values ​​are displayed respectively. The hue of the conductive layer is suppressed, and the color concentration and hue are excellent on the surface of the colored film layer side of the conductive laminate, which can present a high-quality black. Therefore, in addition to the effects of alcohol resistance, surface insulation and productivity, the conductive laminate of the present invention can also achieve excellent surface design and concealment while being thin.

[0108] In detail, the surface of the colored film layer on one side of the conductive laminate of the present invention is made of CIE L * a * b * The colorimetric system specifies a brightness L. * Preferably, the value is 20 or higher, with a preferred value of 21 or higher, a preferred value of 21.5 or higher, a preferred value of 22 or higher, and a preferred value of 22.5 or higher. Additionally, the brightness L... * Preferably, the value is 27 or less, more preferably 25 or less, more preferably 24 or less, and more preferably 23 or less. More specifically, the brightness L... * Preferably, the value is 20 or more and 27 or less, more preferably 21 or more and 25 or less, further preferably 21.5 or more and 24 or less, and more preferably 22 or more and 23 or less. The conductive laminate of the present invention achieves a brightness L measured from the surface of the colored film layer. *Within the aforementioned range, as a conductive laminate, it exhibits excellent blackness and design flexibility, allowing it to blend seamlessly with other colored components in electrical and electronic equipment. Particularly when at least the coloring layer is black, it achieves a unified look with other black components within electrical and electronic equipment, further enhancing its black design flexibility.

[0109] The surface of the colored film layer on one side of the conductive laminate of the present invention is made of CIE L * a * b * The colorimetric a specified by the colorimetric system * Preferably, it is -2 or higher, more preferably -1.5 or higher, more preferably -1 or higher, more preferably -0.5 or higher, and more preferably 0 or higher. Additionally, the chromaticity a... * Preferably, it is 2 or less, more preferably 1.5 or less, more preferably 1 or less, and more preferably 0.5 or less. More specifically, the chromaticity a... * Preferably, the chromaticity is -2 or higher and 2 or lower, more preferably -1 or higher and 1 or lower, and more preferably -0.5 or higher and 0.5 or lower. The conductive laminate of the present invention achieves this by adjusting the chromaticity α measured from the surface of the colored film layer. * Within the aforementioned range, it exhibits excellent color design capabilities as a conductive laminate, and when used in conjunction with other colored components in electrical and electronic equipment, it can achieve a sense of unity with the colors of other components. In particular, when at least the coloring layer is black, it can achieve a sense of unity with other black components in electrical and electronic equipment.

[0110] The surface of the colored film layer on one side of the conductive laminate of the present invention is made of CIE L * a * b * The colorimetric b specified by the colorimetric system * Preferably -2 or higher, more preferably -1.5 or higher, or -1 or higher. Additionally, chromaticity b... * Preferably, it is 2 or less, more preferably 1.5 or less, 1 or less, 0.5 or less, or 0 or less. More specifically, the chromaticity b * Preferably, the chromaticity is -2 or higher and 2 or lower, more preferably -2 or higher and 0 or lower, more preferably -1.5 or higher and 0.5 or lower, more preferably -1.5 or higher and 0 or lower, and more preferably -1 or higher and 0 or lower. The conductive laminate of the present invention achieves this by adjusting the chromaticity b measured from the surface of the colored film layer. * Within the aforementioned range, it exhibits excellent color design capabilities as a conductive laminate, and when used in conjunction with other colored components in electrical and electronic equipment, it can achieve a sense of unity with the colors of other components. In particular, when at least the coloring layer is black, it can achieve a sense of unity with other black components in electrical and electronic equipment.

[0111] The surface of the conductive laminate colored film layer on one side of the present invention is made of CIE L * a * b * The colorimetric system specifies a brightness L. * Preferably, the chromaticity is 20 or higher and 27 or lower, with a chromaticity a. * Preferably, the chromaticity is between -2 and 2, and the chromaticity b is... * Preferably, the value is between -2 and 2. Wherein, the brightness L... * Preferably, the chromaticity is 21 or higher and 25 or lower, with a chromaticity a. * Preferably, the chromaticity is between -1 and 1, and the chromaticity b is... * Preferably, the brightness is above -1.5 and below 0.5, L. * More preferably, the chromaticity is 21.5 or higher and 24 or lower, with a chromaticity a. * More preferably, the chromaticity is -0.5 or higher and 0.5 or lower, with a chromaticity b. * More preferably, it is -1 or higher and 0 or lower.

[0112] The CIE chromaticity value (L) of the surface of the colored film layer of the conductive laminate of the present invention * a * b * The values ​​can be measured according to JIS Z 8722. Specifically, the values ​​are measured from the surface of the colored film layer of the conductive laminate using a KONICA MINOLTA SPECTROPHOTOMETER CM-5, according to the measurement standard JIS Z 8722 with a C spectrum of 2°.

[0113] Furthermore, the 60° gloss value of the surface of the colored film layer side of the conductive laminate of the present invention is preferably 1 or more and 5 or less, more preferably 1 or more and 4 or less, and even more preferably 1 or more and 3 or less. By ensuring that the 60° gloss value measured from the surface of the colored film layer side of the conductive laminate of the present invention is within the above-mentioned range, the glossiness is suppressed. As a conductive laminate, it exhibits excellent matte finish and can suppress the conspicuousness of the conductive laminate caused by glossiness when used in electrical and electronic equipment with other colored components, creating a sense of unity with the color of other components. In particular, when at least the colored layer is black, it exhibits excellent matte black finish and can create a sense of unity with other black components in electrical and electronic equipment.

[0114] The 60° gloss value is the gloss level measured on the surface of the colored film layer of the conductive laminate at a set angle of 60° according to JIS Z 8741. The measurement can be performed using a commercially available measuring device (e.g., the BYK CatNo.4563 Micro-TRI gloss meter).

[0115] The conductive laminate of the present invention, by having the above-described layer configuration, is able to exhibit high insulation on the surface of the colored film layer side while being thin, and high conductivity on the surface of the conductive layer side.

[0116] The surface resistivity of the colored film layer side of the conductive laminate of the present invention is preferably 1×10⁻⁶. 8 Ω / □ or higher, preferably 1×10 9 Ω / □ or higher, further preferably 1×10 10 Ω / □ or higher, more preferably 1×10 11 Ω / □ or higher. The conductive laminate of the present invention, by ensuring that the surface resistivity of the surface on the colored film layer side is within the above-mentioned range, can exhibit higher insulation properties on the surface on the colored film layer side. It should be noted that the higher the surface resistivity of the surface on the colored film layer side of the conductive laminate, the better; typically, it can be set to 1×10⁻⁶. 18 Ω / □ or less, 1×10 16 Ω / □ or less, 1×10 14 Ω / □ or less, 1×10 12 Below Ω / □.

[0117] Furthermore, the surface resistivity of the conductive layer side surface of the conductive laminate of the present invention is preferably 10 mΩ / □ or less, more preferably 1 mΩ / □ or less, and even more preferably 0.6 mΩ / □ or less. By maintaining the surface resistivity of the conductive layer side surface within the above-mentioned range, the conductive laminate of the present invention can exhibit higher conductivity on the conductive layer side surface. It should be noted that the lower the surface resistivity of the conductive layer side surface of the conductive laminate, the better; typically, it can be set to 0.001 mΩ / □ or more.

[0118] The surface resistivity of the colored film layer side and the conductive layer side of the conductive laminate refers to the values ​​measured according to JIS-K6911. It can be measured using a resistivity meter (Loresta MCP-T600 manufactured by Mitsubishi Chemical Corporation) by contacting the 4-terminal probe with the colored film layer side or the conductive layer side of the conductive laminate.

[0119] 5. Method for manufacturing conductive laminates The method for manufacturing the conductive laminate of the present invention is not particularly limited. It includes a coloring film layer formation step, an adhesive layer or bonding agent layer formation step, and a conductive layer formation step. The coloring film layer formation step involves coating at least one side of a resin film layer with a coloring ink capable of having a glass transition temperature after curing within a specified range to form a coloring film layer having both a coloring layer and a resin film layer. The adhesive layer or bonding agent layer formation step involves coating the surface of the coloring film layer on the resin film layer side to form an adhesive layer or bonding agent layer. The conductive layer formation step involves bonding a metal foil as a conductive layer onto the adhesive layer or bonding agent layer. This manufacturing method can suppress curling and wrinkling to produce a conductive laminate, thus exhibiting excellent productivity. Furthermore, it can form a laminate structure that is less prone to interlayer delamination, which is therefore preferred.

[0120] In the process of forming the colored film layer, there is no particular limitation on the method of coating the colored ink on the resin film layer as long as the thickness of the dried colored layer is the desired size. For example, gravure coating can be used.

[0121] In addition, in the process of forming the adhesive layer or bonding agent layer, there is no particular limitation on the method of applying the adhesive or bonding agent as long as the thickness of the dried adhesive layer or bonding agent layer is the desired size. For example, known methods such as microgravure coating, die coating, and lip coating can be used.

[0122] 6. Applications of conductive laminates The conductive laminate of the present invention, by providing an adhesive layer on the surface of the conductive layer side of the monomer or the conductive laminate described later, can be widely used in applications requiring high alcohol resistance and insulation. It is particularly suitable for applications requiring miniaturization and thinness, protection of circuit components in portable electronic devices with high alcohol resistance requirements, electromagnetic wave shielding of internal and external electrical or electronic equipment such as thin mobile devices, or grounding applications.

[0123] II. Conductive adhesive tape The conductive adhesive tape of the present invention has a conductive laminate as described in item "I. Conductive laminate" above and a conductive adhesive layer disposed on the surface of the conductive laminate on one side of the conductive layer. Figure 2 This is a schematic cross-sectional view showing an example of the conductive adhesive tape of the present invention. The conductive adhesive tape 20 has a conductive adhesive layer 11 disposed on the surface of the conductive layer 1 side of the conductive laminate 10.

[0124] The conductive adhesive tape of the present invention exhibits good alcohol resistance and surface insulation on the surface of the colored film layer side, and also has excellent productivity.

[0125] In addition to the functions mentioned above, the conductive adhesive tape of the present invention can also achieve a thinner overall thickness, and can also take into account various characteristics such as conductivity, electromagnetic wave shielding, interlayer tightness, design, and shielding.

[0126] 1. Conductive laminate The conductive laminate in this invention is the same as the one described in the above-mentioned "I. Conductive laminate", so the description is omitted here.

[0127] 2. Conductive adhesive layer The conductive adhesive layer in this invention contains adhesive components and conductive fillers.

[0128] Nickel powder, copper powder, silver powder, gold powder, conductive carbon black, metal-plated glass, resin powder, etc., can be used as conductive fillers. Among them, nickel powder is preferred because it has excellent conductivity on the conductive layer, i.e., the metal foil, in conductive laminates, especially on copper foil and stainless steel foil.

[0129] The content of conductive filler in the conductive adhesive layer can be set to an amount that achieves the desired conductivity, and is not particularly limited. However, within the total amount (100% by mass) of the conductive adhesive layer, it is preferably in the range of 0.1% to 80% by mass, more preferably in the range of 0.5% to 40% by mass, and most preferably in the range of 0.8% to 10% by mass. This is because if the content of conductive filler is within the above range, both conductivity and adhesion can be easily achieved even in thin applications.

[0130] There are no particular limitations on the adhesive components constituting the conductive adhesive layer. For example, they can be appropriately selected from known adhesives such as acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, styrene-diene block copolymer adhesives, vinyl alkyl ether adhesives, polyamide adhesives, fluorinated adhesives, creep-modified adhesives, and radiation-cured adhesives. Two or more adhesive components can be used alone or in combination.

[0131] Among these, acrylic adhesives, in particular, are preferred due to their high bonding reliability as adhesive components. Acrylic adhesives use (meth)acrylic polymers as the adhesive component or main agent, and may include appropriate additives such as crosslinking agents, tackifiers, softeners, plasticizers, fillers, anti-aging agents, and colorants, as needed. (Meth)acrylic polymers are polymers with alkyl (meth)acrylates as the main monomer component, and are prepared by using monomers capable of copolymerizing with (meth)alkyl esters (copolymeric monomers), as needed.

[0132] As an acrylic copolymer, an acrylic copolymer with (meth)acrylate monomers having 1 to 14 carbon atoms as the main monomer component is preferably used. Examples of (meth)acrylate monomers having 1 to 14 carbon atoms include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, isononyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexyl methacrylate. One or more of these monomers can be used. Among them, (meth)acrylates with alkyl groups having 4 to 12 carbon atoms are preferred, and (meth)acrylates with 4 to 9 carbon atoms having a straight-chain or branched structure are more preferred. Among them, n-butyl acrylate and 2-ethylhexyl acrylate are preferred, and they can be used alone or in combination.

[0133] The content of (meth)acrylate with 1 to 14 carbon atoms in the acrylic copolymer is preferably 80% to 98.5% by mass of the monomer components constituting the acrylic copolymer, more preferably 90% to 98.5% by mass.

[0134] Furthermore, acrylic copolymers preferably copolymerize highly polar vinyl monomers. Examples of highly polar vinyl monomers include vinyl monomers with carboxyl groups, vinyl monomers with hydroxyl groups, and vinyl monomers with amide groups; one or more of these can be used. Among them, monomers containing carboxyl groups are preferred because they readily adjust the adhesive properties of the adhesive to a suitable range.

[0135] As a vinyl monomer with a carboxyl group, acrylic acid, methacrylic acid, itaconic acid, maleic acid, (meth)acrylic acid dimer, crotonic acid, ethylene oxide modified succinic acid acrylate, etc. can be used, among which acrylic acid is preferred as a copolymer component.

[0136] When using vinyl monomers with carboxyl groups, their content is preferably 0.2% to 15% by mass of the monomer component constituting the acrylic copolymer, more preferably 0.4% to 10% by mass, and even more preferably 0.5% to 6% by mass. By containing them within this range, the adhesive properties of the adhesive can be easily adjusted to a suitable range.

[0137] As monomers containing hydroxyl groups, hydroxyl-containing (meth)acrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, and 6-hydroxyhexyl methacrylate can be used.

[0138] In addition, examples of monomers with amide groups include N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, acrylamide, and N,N-dimethylacrylamide.

[0139] Other highly polar vinyl monomers include vinyl acetate, ethylene oxide-modified succinic acid acrylate, 2-acrylamide-2-methylpropanesulfonic acid and other sulfonic acid-containing monomers, (meth)acrylate-2-methoxyethyl ester, (meth)acrylate-2-phenoxyethyl ester and other terminal alkoxy-modified (meth)acrylates.

[0140] The content of highly polar vinyl monomers is preferably 0.2% to 15% by mass of the monomer components constituting the acrylic copolymer, more preferably 0.4% to 10% by mass, and even more preferably 0.5% to 6% by mass. By including it in this range, the adhesive properties of the adhesive can be easily adjusted to a suitable range.

[0141] The weight-average molecular weight (Mw) of the (meth)acrylic polymer is preferably 500,000 or more, 600,000 or more, or 700,000 or more. Furthermore, the weight-average molecular weight (Mw) of the (meth)acrylic polymer is preferably 2,000,000 or less, 1,800,000 or less, 1,600,000 or less, 1,200,000 or less, or 1,000,000 or less. By setting the weight-average molecular weight (Mw) of the (meth)acrylic polymer within the above range, the conductive adhesive layer can exhibit good initial adhesion to the conductive layer in the conductive laminate. More specifically, the weight-average molecular weight (Mw) of the (meth)acrylic polymer is preferably in the range of 500,000 to 1,200,000, and more preferably in the range of 500,000 to 1,000,000.

[0142] (Meth)acrylic acid polymers can be prepared using conventional polymerization methods such as solution polymerization, emulsion polymerization, and ultraviolet irradiation polymerization.

[0143] To improve adhesion, a tackifying resin can be added to the conductive adhesive layer. Examples of tackifying resins include rosin-based resins such as rosin and rosin ester compounds; terpene-based resins such as diterpene polymers and α-pinene-phenol copolymers; petroleum resins such as aliphatic (C5) and aromatic (C9) resins; styrene-based resins; phenolic resins; xylene resins; and methacrylic resins. Among these, a rosin-based resin is preferred for thinness and improved adhesion, and a polymerized rosin-based resin is more preferred. In addition to rosin-based resins, a styrene-based resin may also be incorporated.

[0144] Furthermore, to improve initial adhesion, it is preferable to use a tackifying resin that is liquid at room temperature. Examples of tackifying resins that are liquid at room temperature include liquid resins of the aforementioned tackifying resins, processing oils, polyester plasticizers, and low molecular weight liquid rubbers such as polybutene. Terpene phenolic resins are particularly preferred. Commercially available products include YP-90L manufactured by Yasuhara Chemical Co., Ltd.

[0145] The amount of tackifying resin added is preferably in the range of 10 to 70 parts by weight relative to 100 parts by weight of the acrylic copolymer. More preferably, it is in the range of 20 to 60 parts by weight. By adding the tackifying resin within the above range, the adhesive strength can be improved.

[0146] There is no particular limitation on the gel fraction of the conductive adhesive layer, which is 10 to 60% by mass. Even if the thickness is thin, it is easy to exhibit sufficient adhesion. Therefore, it is preferred, more preferably 20 to 50% by mass, and even more preferably 25 to 45% by mass.

[0147] The gel fraction of the conductive adhesive layer is: the mass of the dried insoluble component remaining after the aging conductive adhesive layer is immersed in toluene and left for 24 hours is measured and expressed as a percentage relative to the original mass. Gel fraction (mass%) = [(mass of conductive adhesive layer after toluene impregnation) / (mass of conductive adhesive layer before toluene impregnation)] × 100

[0148] The energy storage modulus of the conductive adhesive layer at 25°C is preferably 1×10⁻⁶. 4 Above and 5×10 5 Pa or less, more preferably 2×10 Pa 4 Above and 1×10 5 The value is below Pa. This is because by ensuring the storage modulus of the conductive adhesive layer at 25°C is within the aforementioned range, even for thin-film conductive adhesive layers, a high degree of balance between adhesion and processability can be easily achieved. It should be noted that the storage modulus of the conductive adhesive layer at 25°C is a value obtained using the same method and conditions as the method described above for determining the storage modulus of the adhesive layer at 25°C.

[0149] The aforementioned conductive adhesive layer can be a single-layer structure or a multi-layer structure with conductive adhesive layers provided on both sides of the conductive substrate. Examples of conductive substrates with multi-layer conductive adhesive layers include metal foil substrates and substrates obtained by plating wet-process polyester nonwoven fabric substrates. Examples of materials for the metal foil include gold, silver, copper, aluminum, nickel, iron, tin, and their alloys. Furthermore, examples of substrates obtained by plating wet-process polyester nonwoven fabric substrates include substrates using electroless metal plating. Examples of plating metals include copper, nickel, silver, platinum, and aluminum; copper or nickel is preferred from the viewpoint of conductivity and cost. It should be noted that the thickness of the aforementioned conductive substrate is not particularly limited, and can be, for example, from 1 μm to 50 μm or less.

[0150] The thickness of the conductive adhesive layer can be set to achieve both conductivity and adhesion (or bonding), preferably 2 μm or more and 60 μm or less, and more preferably 3 μm or more and 10 μm or less. By setting the thickness of the conductive adhesive layer within the above range, the total thickness of the conductive adhesive tape of the present invention can be reduced, and the conductivity can be further improved.

[0151] In addition, when the conductive adhesive layer has a multilayer structure, the overall thickness of the multilayer structure is preferably 3 μm or more and 60 μm or less, and more preferably 5 μm or more and 10 μm or less.

[0152] In the conductive adhesive tape of the present invention, the conductive adhesive layer may be disposed over the entire surface of the conductive layer side of the conductive laminate, or it may be disposed in a pattern on the surface of the conductive layer side of the conductive laminate. When the conductive adhesive layer is patterned, the surface of the conductive layer may be exposed in areas on the surface of the conductive layer side of the conductive laminate where no conductive adhesive layer is disposed. Alternatively, an insulating adhesive layer may be disposed in these areas, with the conductive adhesive layer and the insulating adhesive layer alternately arranged in a pattern. This alternating arrangement of the conductive adhesive layer and the insulating adhesive layer in a pattern improves adhesion and is therefore preferred.

[0153] When conductive adhesive layers and insulating adhesive layers are alternately arranged in a pattern on the surface of the conductive layer side of a conductive laminate, the insulating adhesive layer can be made the same as the conductive adhesive layer, except that it does not contain the conductive filler of the conductive adhesive layer.

[0154] 3. Arbitrary composition The conductive adhesive tape of the present invention includes at least the aforementioned conductive laminate and conductive adhesive layer in its composition, and may also include other compositions. For example, a release layer may be further provided on the surface of the conductive adhesive layer opposite to the aforementioned conductive laminate. This is because providing a release layer protects the conductive adhesive tape.

[0155] As the release layer, a known release layer can be appropriately selected. Resin films obtained by demolding resin films exhibit excellent smoothness and are therefore preferred. From the viewpoint of excellent heat resistance, polyester films are preferred.

[0156] To impart easy peelability, the release layer preferably undergoes a surface peeling treatment. Specifically, the surface of the release layer preferably has a peeling treatment layer. This peeling treatment layer can be formed from a common release agent used in the application of release layers for double-sided adhesive tapes. Examples of such release agents include silicone-based, fluorine-based, and long-chain alkyl-based release agents. The release treatment layer can be formed by lamination or coating.

[0157] The peel force of the release layer can be adjusted appropriately according to the usage method, etc. For conductive adhesive tape, the peel force can be set to 0.01N / 20mm to 2N / 20mm, preferably 0.05N / 20mm to 0.15N / 20mm. This facilitates the suppression of deformation of the conductive adhesive tape during peeling. The peel force can be measured by the following method: using the exposed surface of the conductive adhesive layer of the conductive adhesive tape as the release layer, with a 50μm thick PET film as a liner, peeling in a 180° direction at a speed of 0.3m / min to 10m / min.

[0158] 4. Conductive adhesive tape The total thickness of the conductive adhesive tape of the present invention is preferably 10 μm or more and 50 μm or less, more preferably 15 μm or more and 45 μm or less, and even more preferably 20 μm or more and 40 μm or less. By setting the total thickness of the conductive adhesive tape within the above range, the total thickness is small and the tape is thin, and it can exhibit good alcohol resistance and surface insulation properties. In addition, it can also effectively perform functions such as conductivity, electromagnetic wave shielding, interlayer adhesion, design flexibility, and concealment. Furthermore, the above-mentioned conductive adhesive tape can be obtained with high productivity. It should be noted that the total thickness of the conductive adhesive tape referred to in this specification does not include the thickness of the release layer.

[0159] The conductive adhesive tape of the present invention is obtained from the surface of one side of the conductive laminate, as measured by CIE L. * a * b * The colorimetric system specifies a brightness L. * chromaticity a * chromaticity b *Preferably, the conductive laminate described in section I. Conductive Laminates, measured from the surface of the colored film layer side of the conductive laminate, is obtained by CIE L. * a * b * The colorimetric system specifies a brightness L. * chromaticity a * chromaticity b * Within that range. The reason is that CIE L * a * b * The colorimetric system specifies a brightness L. * chromaticity a * and chromaticity b * The balance becomes good, and the conductive adhesive tape of the present invention can achieve good color design and concealment. At this time, the adhesive layer or bonding agent layer between the colored film layer and the conductive layer is colored, and more preferably black.

[0160] Furthermore, the 60° gloss value of the conductive adhesive tape of the present invention, measured from the surface of the conductive laminate side, is preferably within the range of the 60° gloss value measured from the surface of the colored film layer side of the conductive laminate as described in the above-mentioned item "I. Conductive Laminate".

[0161] The CIE colorimetric value (L) of the conductive laminate side surface of the conductive adhesive tape of the present invention * a * b * The 60° gloss value and the 60° gloss value are respectively the CIE colorimetric values ​​(L) of the surface of the colored film layer side of the conductive laminate described in the above "I. Conductive Laminates" section. * a * b * The values ​​were obtained by measuring the 60° gloss value using the same methods and conditions as those used for measuring 60° gloss.

[0162] The surface resistivity of the conductive adhesive tape of the present invention, measured from the surface of the conductive laminate, is preferably within the range of surface resistivity measured from the surface of the colored film layer of the conductive laminate as described in the above-mentioned item "I. Conductive Laminate".

[0163] Furthermore, the surface resistivity of the conductive adhesive tape of the present invention, measured from the surface of the conductive adhesive side, is preferably 10 mΩ / □ or less, more preferably 1 mΩ / □ or less, and even more preferably 0.6 mΩ / □ or less. It should be noted that the lower the surface resistivity of the conductive adhesive tape measured from the surface of the conductive adhesive side, the better; typically, it can be set to 0.001 mΩ / □ or more.

[0164] It should be noted that the surface resistivity of the conductive laminate side and the conductive adhesive layer side of the conductive adhesive tape refers to the values ​​measured according to JIS-K6911. It can be measured using a resistivity meter (Loresta MCP-T600 manufactured by Mitsubishi Chemical Corporation) by contacting the 4-terminal probe with the surface of the conductive laminate side or the surface of the conductive adhesive layer side of the conductive adhesive tape.

[0165] 5. Manufacturing method of conductive adhesive tape The manufacturing method of the conductive adhesive tape of the present invention is not particularly limited. For example, a manufacturing method having the following steps can be used: a step of preparing the conductive laminate as described in item "I. Conductive laminate" above; a step of preparing a conductive adhesive comprising conductive filler and adhesive components; and a step of applying the conductive adhesive to the surface of the conductive layer side of the conductive laminate in such a way that the thickness after drying is the desired size to form a conductive adhesive layer.

[0166] The conductive adhesive tape of the present invention can be used in the same way as the use described in item "I. Conductive laminate" above.

[0167] This invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any technical solutions having the same structure and achieving the same effect as those described in the claims of this invention are included within the technical scope of this invention.

Example

[0168] Hereinafter, embodiments of the present invention will be described in more detail. It should be noted that in the manufacture of adhesives, the term "parts" indicating the amount of material is "parts by mass".

[0169] (Manufacturing of Adhesive A) A solution of 97.98 parts n-butyl acrylate, 2 parts acrylic acid, 0.02 parts 4-hydroxybutyl acrylate, and 0.2 parts azobisisobutyronitrile (AIB) as a polymerization initiator was solution polymerized in ethyl acetate solution at 80°C for 8 hours to obtain an acrylic polymer with a mass-average molecular weight of 900,000. 5 parts of polymerized rosin ester (trade name "D-135", manufactured by Arakawa Chemical Co., Ltd.), 20 parts of disproportionated rosin ester (trade name "KE-100", manufactured by Arakawa Chemical Co., Ltd.), and 25 parts of petroleum resin (trade name "FTR6100") were added to 100 parts of this acrylic polymer, along with ethyl acetate, to prepare an adhesive solution with a solid content of 40%. 0.8 parts of an isocyanate-based crosslinking agent (trade name "NC40", manufactured by DIC Co., Ltd.) were further added to the above adhesive solution, and the mixture was stirred until homogeneous to prepare adhesive A. Adhesive A had a gel fraction of 20% and a storage modulus of 9 × 10⁻⁶ at 25°C. 4 Pa.

[0170] (Manufacturing of Adhesive B) A solution of 97.98 parts n-butyl acrylate, 2 parts acrylic acid, 0.02 parts 4-hydroxybutyl acrylate, and 0.2 parts azobisisobutyronitrile (a polymerization initiator) was solution polymerized in ethyl acetate solution at 80°C for 8 hours to obtain an acrylic polymer with a mass average molecular weight of 900,000. Then, 5 parts polymerized rosin ester (trade name "D-135", manufactured by Arakawa Chemical Co., Ltd.), 20 parts disproportionated rosin ester (trade name "KE-100", manufactured by Arakawa Chemical Co., Ltd.), and 25 parts petroleum resin (trade name "FTR6100") were added to 100 parts of this acrylic polymer, along with ethyl acetate, to prepare an adhesive solution with a solid content of 40%. Next, 10 parts of a black colorant "DICTON BLACK AR8555" (carbon black content: 45% (solids percentage), resin solids concentration: 49%) manufactured by DIC was added to the above adhesive solution and mixed thoroughly using a mixer. Then, 1.2 parts of an isocyanate-based crosslinking agent (trade name "NC40," manufactured by DIC) were added and stirred until homogeneous, thus preparing adhesive B. Adhesive B has a gel fraction of 20% and a storage modulus of 8 × 10⁻⁶ at 25°C. 4 Pa.

[0171] (Preparation of conductive adhesive A) In a reaction vessel equipped with a condenser, stirrer, thermometer, and dropping funnel, 75.0 parts by weight of n-butyl acrylate, 19.0 parts by weight of 2-ethylhexyl acrylate, 3.9 parts by weight of vinyl acetate, 2.0 parts by weight of acrylic acid, 0.1 parts by weight of 2-hydroxyethyl acrylate, and 0.1 parts by weight of 2,2'-azobisisobutyronitrile (2,2'-azobisisobutyronitrile) as a polymerization initiator were dissolved in 100 parts by weight of ethyl acetate. After nitrogen replacement, polymerization was carried out at 80°C for 12 hours to obtain acrylic polymer B with a weight average molecular weight of 600,000.

[0172] Next, 10 parts by mass of polymerized pentaerythritol rosin (manufactured by Arakawa Chemical Industry Co., Ltd., "Pensel D-135", softening point 135°C) and 10 parts by mass of disproportionated rosin glycerol ester (manufactured by Arakawa Chemical Industry Co., Ltd., "Superester A-100", softening point 100°C) were added to 100 parts by mass of the solid component of acrylic polymer B, and ethyl acetate was used to adjust the concentration of the solid component of acrylic polymer to 40% by mass, thereby obtaining acrylic adhesive solution B.

[0173] Using a dispersing mixer, 100 parts by weight of acrylic adhesive solution B (solid content concentration 40% by mass), 0.4 parts by weight of nickel powder ("NI255T" beaded conductive particles manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., d50: 26.0 μm), 2 parts by weight of isocyanate crosslinking agent ("Burnock NC40" manufactured by DIC Co., Ltd., solid content 40% by mass) as crosslinking agent, and 70 parts by weight of ethyl acetate as diluent were mixed for 10 minutes to prepare conductive adhesive A.

[0174] (Manufacturing of polyester polyol resin A) In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 50 parts by mass of isophthalic acid, 50 parts by mass of neopentyl glycol, 60 parts by mass of toluene, and 40 parts by mass of methyl ethyl ketone were added. The mixture was stirred and reacted at 80°C for 10 hours to obtain polyester polyol resin A with a resin solid content of 50% and a mass-average molecular weight of 40,000.

[0175] (Manufacturing of polyester polyol resin B) In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 40 parts by mass of isophthalic acid, 60 parts by mass of neopentyl glycol, 60 parts by mass of toluene, and 40 parts by mass of methyl ethyl ketone were added. The mixture was stirred and reacted at 80°C for 10 hours to obtain polyester polyol resin B with a resin solid content of 50% and a mass-average molecular weight of 40,000.

[0176] (Manufacturing of polyester polyol resin C) In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 63 parts by mass of isophthalic acid and 37 parts by mass of neopentyl glycol were added. The mixture was stirred and reacted at 80°C for 1 hour. Then, 60 parts by mass of toluene and 40 parts by mass of methyl ethyl ketone were added, and the mixture was stirred and reacted at 80°C for 10 hours to obtain polyester polyol resin C with a resin solid content of 50% and a mass-average molecular weight of 50,000.

[0177] (Manufacturing of polyester polyurethane resin D) In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 50 parts by weight of isophthalic acid, 50 parts by weight of neopentyl glycol, 80 parts by weight of toluene, and 40 parts by weight of methyl ethyl ketone were added. The mixture was stirred and reacted at 80°C for 4 hours. Then, 40 parts by weight of isophorone diisocyanate and 20 parts by weight of methyl ethyl ketone were mixed and reacted at 100°C for about 1 hour to obtain polyester polyurethane resin D with a resin solid content of 50% and a mass-average molecular weight of 40,000.

[0178] (Manufacturing of polyester polyol resin E) In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 67 parts by mass of isophthalic acid and 33 parts by mass of neopentyl glycol were added. The mixture was stirred and reacted at 80°C for 2 hours. Then, 60 parts by mass of toluene and 40 parts by mass of methyl ethyl ketone were added, and the mixture was stirred and reacted at 80°C for 10 hours to obtain polyester polyol resin E with a resin solid content of 50% and a mass-average molecular weight of 80,000.

[0179] (Manufacturing of polyester polyol resin F) In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet tube, 25 parts by mass of isophthalic acid, 75 parts by mass of neopentyl glycol, 60 parts by mass of toluene, and 40 parts by mass of methyl ethyl ketone were added. The mixture was stirred and reacted at 80°C for 10 hours to obtain polyester polyol resin F with a resin solid content of 50% and a mass-average molecular weight of 20,000.

[0180] (Manufacturing of Black Ink A) 100 parts by weight of polyester polyol resin A (50% by weight of resin solids), 40 parts by weight of carbon black "CarbonSpecial 250P" manufactured by Degussa, 5 parts by weight of inorganic filler ("Sylophobic 704" manufactured by Fuji SILYSIA, silane-coupled treatment: average particle size of 3.5 μm based on Coulter counting method), 23 parts by weight of methyl ethyl ketone, 13 parts by weight of toluene, 6 parts by weight of ethyl acetate, 3 parts by weight of n-propyl acetate, and 3 parts by weight of isopropanol were added. The mixture was wet-dispersed in a sand mill for about 1 hour. Then, 2 parts by weight of curing agent "KR90" (biuret form of hexamethylene diisocyanate, 40% by weight of solids) manufactured by DIC and 300 parts by weight of ethyl acetate were added to produce black ink A. The carbon black content in the solids of the black ink was 42% by weight.

[0181] (Manufacturing of Black Ink B) 100 parts by weight of polyester polyol resin B (50% solids content), 40 parts by weight of carbon black "CarbonSpecial 250P" manufactured by Degussa, 5 parts by weight of inorganic filler ("Sylophobic 704" manufactured by Fuji SILYSIA, silane-coupled treatment: average particle size of 3.5 μm based on Coulter counting method), 23 parts by weight of methyl ethyl ketone, 13 parts by weight of toluene, 6 parts by weight of ethyl acetate, 3 parts by weight of n-propyl acetate, and 3 parts by weight of isopropanol were added. The mixture was wet-dispersed in a sand mill for approximately 1 hour. Then, 2 parts by weight of curing agent "KR90" (a biuret form of hexamethylene diisocyanate, 40% solids content) manufactured by DIC and 300 parts by ethyl acetate were added to produce black ink B. The carbon black content in the solids content of the black ink was 42%.

[0182] (Manufacturing of black ink C) 100 parts by weight of polyester polyol resin C (50% solids content), 40 parts by weight of carbon black "CarbonSpecial 250P" manufactured by Degussa, 5 parts by weight of inorganic filler ("Sylophobic 704" manufactured by Fuji SILYSIA, silane-coupled treatment: average particle size of 3.5 μm based on Coulter counting method), 23 parts by weight of methyl ethyl ketone, 13 parts by weight of toluene, 6 parts by weight of ethyl acetate, 3 parts by weight of n-propyl acetate, and 3 parts by weight of isopropanol were added. The mixture was wet-dispersed in a sand mill for approximately 1 hour. Then, 2 parts by weight of curing agent "KR90" (a biuret form of hexamethylene diisocyanate, 40% solids content) manufactured by DIC and 300 parts by ethyl acetate were added to produce black ink C. The carbon black content in the solids content of the black ink was 42%.

[0183] (Manufacturing of black ink D) 100 parts by weight of polyester polyurethane resin D (50% solids content), 40 parts by weight of carbon black "CarbonSpecial 250P" manufactured by Degussa, 5 parts by weight of inorganic filler ("Sylophobic 704" manufactured by Fuji SILYSIA, silane-coupled treatment: average particle size of 3.5 μm based on Coulter counting method), 23 parts by weight of methyl ethyl ketone, 13 parts by weight of toluene, 6 parts by weight of ethyl acetate, 3 parts by weight of n-propyl acetate, and 3 parts by weight of isopropanol were added. The mixture was wet-dispersed in a sand mill for about 1 hour. Then, 2 parts by weight of curing agent "KR90" (biuret form of hexamethylene diisocyanate, 40% solids content) manufactured by DIC and 300 parts by ethyl acetate were added to produce black ink D. The carbon black content in the solids content of the black ink is 42%.

[0184] (Manufacturing of black ink E) 100 parts by weight of polyester polyol resin E (50% solids content), 40 parts by weight of carbon black "CarbonSpecial 250P" manufactured by Degussa, 5 parts by weight of inorganic filler ("Sylophobic 704" manufactured by Fuji SILYSIA, silane-coupled treatment: average particle size of 3.5 μm based on Coulter counting method), 23 parts by weight of methyl ethyl ketone, 13 parts by weight of toluene, 6 parts by weight of ethyl acetate, 3 parts by weight of n-propyl acetate, and 3 parts by weight of isopropanol were added. The mixture was wet-dispersed in a sand mill for approximately 1 hour. Then, 2 parts by weight of curing agent "KR90" (a biuret form of hexamethylene diisocyanate, 40% solids content) manufactured by DIC and 300 parts by ethyl acetate were added to produce black ink F. The carbon black content in the solids content of the black ink was 42%.

[0185] (Manufacturing of black ink F) 100 parts by weight of polyester polyol resin F (50% solids content), 40 parts by weight of carbon black "CarbonSpecial 250P" manufactured by Degussa, 5 parts by weight of inorganic filler ("Sylophobic 704" manufactured by Fuji SILYSIA, silane-coupled treatment: average particle size of 3.5 μm based on Coulter counting method), 23 parts by weight of methyl ethyl ketone, 13 parts by weight of toluene, 6 parts by weight of ethyl acetate, 3 parts by weight of n-propyl acetate, and 3 parts by weight of isopropanol were added. The mixture was wet-dispersed in a sand mill for about 1 hour. Then, 2 parts by weight of curing agent "KR90" manufactured by DIC (a biuret form of hexamethylene diisocyanate, 40% solids content) and 300 parts by weight of ethyl acetate were added to the product to prepare black ink G. The carbon black content in the solids content of the black ink was 42%.

[0186] 1. Fabrication of conductive laminates [Example 1-1] Black ink A was gravure-coated onto a Toray-manufactured polyester film Lumirror 2F51 (thickness: 2 μm) to a dry thickness of 2 μm, forming a colored layer. The film was then cured at 40°C for 1 day to obtain a black ink-coated film A (colored film layer A). The glass transition temperature of the cured black ink A, i.e., the colored film layer A, was 51°C. It should be noted that the glass transition temperature of the colored layer was determined using DSC according to ISO 3146. The determination of the glass transition temperature of the colored layers in other examples and comparative examples will be conducted in the following text.

[0187] Next, adhesive B is gravure-coated on the polyester film side of the black ink coating film A to a thickness of 1 μm after drying. After drying at 70°C for 2 minutes to form a black adhesive layer B, an electrolytic copper foil NC-WS6μm (thickness: 6μm) manufactured by Furukawa Electric Industries, which serves as a conductive layer, is bonded to the side of adhesive layer B. The substrate is then further cured at 40°C for 2 days to obtain conductive laminate I.

[0188] [Examples 1-2] Black ink B was used instead of black ink A to form the coloring layer. Otherwise, the same as in Examples 1-1, a black coated film B (coloring film layer B) and a conductive laminate II were obtained. The glass transition temperature of the cured black ink B, i.e., the coloring layer of coloring film B, was 48°C.

[0189] [Examples 1-3] Black ink C is used instead of black ink A to form the coloring layer. Otherwise, the same as in Examples 1-1, a black ink coated film C (coloring film layer C) and a conductive laminate III are obtained. The glass transition temperature of the cured black ink C, i.e., the coloring film C, is 68°C.

[0190] [Examples 1-4] Using a Toray-manufactured polyester film Lumirror S10#12 (thickness: 12 μm) instead of the Toray-manufactured polyester film Lumirror 2F51 (thickness: 2 μm), a black ink-coated film A1 (colored film layer A1) and a conductive laminate IV were obtained, otherwise identical to those in Examples 1-1. The glass transition temperature of the cured black ink A, i.e., the colored layer of colored film A1, was 51°C.

[0191] [Examples 1-5] Using a polyimide film Kapton 20EN (thickness: 5 μm) manufactured by Toray DuPont instead of the polyester film Lumirror 2F51 (thickness: 2 μm) manufactured by Toray, a black ink-coated film A2 (colored film A2) and a conductive laminate V were obtained in the same manner as in Examples 1-1. The glass transition temperature of the cured black ink A, i.e., the colored layer of colored film A2, was 51°C.

[0192] [Examples 1-6] As the conductive layer, Furukawa Electric Industries' NC-WS15μm (thickness: 15μm) electrolytic copper foil was used instead of Furukawa Electric Industries' NC-WS6μm (thickness: 6μm) electrolytic copper foil. Otherwise, the conductive laminate VI was obtained in the same manner as in Example 1-1. The glass transition temperature of the cured black ink A, i.e., the coloring film A, is 51°C.

[0193] [Examples 1-7] As the conductive layer, Furukawa Electric Industries' NC-WS30μm (thickness: 30μm) electrolytic copper foil was used instead of Furukawa Electric Industries' NC-WS6μm (thickness: 6μm) electrolytic copper foil. Otherwise, the conductive laminate VII was obtained in the same manner as in Examples 1-1. The glass transition temperature of the cured black ink A, i.e., the coloring film A, is 51°C.

[0194] [Comparative Example 1-1] Using black ink D instead of black ink A, the process was otherwise the same as in Example 1, resulting in a black ink coated film D (colored film D) and a conductive laminate VIII. The glass transition temperature of the cured black ink D, i.e., the colored layer of the colored film D, was -20°C.

[0195] [Comparative Examples 1-2] Using black ink E instead of black ink A, the process was otherwise the same as in Example 1, resulting in a black ink coated film E (colored film E) and a conductive laminate IX. The glass transition temperature of the cured black ink E, i.e., the colored layer of the colored film E, was 72°C.

[0196] [Comparative Examples 1-3] Using black ink F instead of black ink A, the process was otherwise the same as in Example 1, resulting in a black ink coated film F (colored film F) and a conductive laminate X. The glass transition temperature of the cured black ink F, i.e., the colored layer of the colored film F, was 41°C.

[0197] [Comparative Examples 1-4] A conductive laminate XI is fabricated by laminating an adhesive tape (IL-10BMF manufactured by DIC Corporation, consisting of a black coloring layer (containing urethane resin, thickness: 1.5 μm), a polyethylene terephthalate film (thickness: 4.5 μm), and a transparent adhesive layer (thickness: 4 μm) with a total thickness of 10 μm (" / " indicates the lamination interface) onto the smooth surface of an electrolytic copper foil CF-T8G-DK-35 (thickness: 35 μm) manufactured by Fukuda Metal Foil Powder Industry, which serves as the conductive layer. The glass transition temperature of the black coloring layer in the conductive laminate XI is -20°C.

[0198] [Comparative Examples 1-5] On one side of a 5μm thick PET film ("Mylar" manufactured by Teijin-DuPont Film Co., Ltd.), at 3g / m 2 (Conversion of Dry Coating Amount) The coating uses an isocyanate-based curing agent ("Coronate L" manufactured by Nippon Polyurethane Kogyo Co., Ltd.) and a polyester resin ("UE3220" manufactured by Unigico Co., Ltd.). A 7μm thick flexible aluminum foil (1030N-0 material from Nippon Foil Co., Ltd.) is laminated on the coating as conductive layer A. In addition, on the other side of the PET film, a 7μm thick flexible aluminum foil (1030N-0 material, Nippon Foil Co., Ltd.) is laminated as conductive layer B using the same method to form the substrate.

[0199] Next, an insulating black ink (an ink made by dispersing aniline black in polyester resin) is applied to one side of the substrate to a dry thickness of 3 μm and then dried to form a black coloring layer, thereby obtaining the conductive laminate XII. The glass transition temperature of the black coloring layer of the conductive laminate XII is 75°C.

[0200] 2. Manufacturing of conductive adhesive tape [Example 2-1] First, the conductive adhesive A was coated onto the release film ("PET25×J0L" manufactured by Nippa Corporation) with a dry thickness of 5 μm using a roller coater. After drying at 100°C for 1 minute, it was bonded to the copper foil surface of the conductive laminate I and further cured at 40°C for 2 days to obtain the conductive adhesive tape.

[0201] [Example 2-2] The conductive adhesive tape is obtained by replacing conductive laminate I with conductive laminate II, otherwise the same as in Example 2-1.

[0202] [Examples 2-3] The conductive adhesive tape is obtained by replacing conductive laminate I with conductive laminate III, otherwise the same as in Example 2-1.

[0203] [Examples 2-4] The conductive adhesive tape is obtained by replacing the conductive laminate I with conductive laminate IV, otherwise the same as in Example 2-1.

[0204] [Examples 2-5] The conductive adhesive tape is obtained by replacing the conductive laminate I with a conductive laminate V, otherwise the same as in Example 2-1.

[0205] [Examples 2-6] The conductive adhesive tape is obtained by replacing the conductive laminate I with a conductive laminate VI, otherwise the same as in Example 2-1.

[0206] [Examples 2-7] The conductive adhesive tape is obtained by replacing the conductive laminate I with conductive laminate VII, otherwise the same as in Example 2-1.

[0207] [Comparative Example 2-1] The conductive adhesive tape is obtained by replacing conductive laminate I with conductive laminate VIII, otherwise the same as in Example 2-1.

[0208] [Comparative Example 2-2] The conductive adhesive tape is obtained by replacing the conductive laminate I with conductive laminate IX, otherwise the same as in Example 2-1.

[0209] [Comparative Examples 2-3] The conductive adhesive tape is obtained by replacing the conductive laminate I with a conductive laminate X, otherwise the same as in Example 2-1.

[0210] [Comparative Examples 2-4] The conductive adhesive tape is obtained by replacing the conductive laminate I with the conductive laminate XI, otherwise the same as in Example 2-1.

[0211] [Comparative Examples 2-5] The conductive adhesive tape is obtained by replacing conductive laminate I with conductive laminate XII, otherwise the same as in Example 2-1.

[0212] [evaluate] The performance of the conductive laminates of the Examples and Comparative Examples, as well as the conductive adhesive tapes of the Examples and Comparative Examples, was evaluated using the following measurement methods.

[0213] (thickness) The thickness of the conductive laminates and conductive adhesive tapes of the examples and comparative examples was measured using a thickness gauge (DIGIMICRO MFC-101 manufactured by NIKON Corporation).

[0214] (thinness) The thickness of the conductive laminates in the embodiments and comparative examples was evaluated according to the following evaluation criteria. ◎: Less than 25μm 〇: 25μm or larger and less than 45μm ×: 45μm or more

[0215] (Alcohol resistance) For the same area on the surface of the conductive laminate on the side of the colored film layer (the surface on the side of the black colored layer in Comparative Examples 1-4 and 1-5), a cotton swab soaked in ethanol was used to wipe it 50 times, and the number of wiping times when the colored layer faded and the cotton swab became stained was evaluated. ◎: The number of times is 50 or more. 〇: The number of times is more than 25 and less than 50. ×: The number of times is less than 24.

[0216] (productivity) Large-sized conductive laminates of Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-4 were produced using the following method. First, a large black ink coating film (large coloring film layer) with a width of 1040 mm and a length of 1000 mm was produced using the same method as that used to produce the coloring film layer in the conductive laminates of Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-3. Next, black adhesive B was gravure coated onto the resin film side of the large black ink coating film (large coloring film layer) using a gravure coating machine at a speed of 20 m / min, and dried at 70°C for 30 seconds to form an adhesive layer with a width of 1030 mm, a length of 1000 mm, and a thickness of 1 μm after drying.

[0217] Next, a metal foil with a width of 1040 mm and a length of 1000 mm is bonded to the adhesive layer on the side of the resin film layer formed on the large black ink coating film to form a large conductive laminate. Comparative Examples 1-4 use an adhesive tape ("IL-10BMF" manufactured by DIC Corporation) with a width of 1040 mm and a length of 1000 mm and a total thickness of 10 μm. A metal foil with a width of 1040 mm and a length of 1000 mm is bonded to the transparent adhesive layer side of the large adhesive tape to form a large conductive laminate.

[0218] The productivity of manufacturing large conductive laminates using the above method is evaluated according to the following benchmarks. It should be noted that the pathline of the gravure coating machine is 50m. Furthermore, the yield will be the effective area of ​​the resulting large conductive laminate (width 1000mm × length 1000m = 1000m). 2 () as the denominator, through the ability to produce several m 2 The product is evaluated based on its quality (no wrinkles). ◎: Capable of production without problems, with a yield of over 90% (900m of good quality). 2 above). 〇: Some wrinkles are mixed in, but the yield is more than 80% and less than 90%. ×: Wrinkles occur when bonded with metal foil, resulting in a yield of less than 80%.

[0219] (Seamless fit) A piece of cellophane tape manufactured by NICHIBAN was applied to the surface of the conductive laminate on the side of the colored film layer (the surface of the black colored layer in Comparative Examples 1-4 and 1-5). The tape was pressed together by rubbing it with the pad of the thumb 5-6 times. After pressing, it was left for about 1 minute, and then one end of the cellophane tape was grasped and forcefully peeled off in a 180° direction (peeling speed: about 50 m / min). The condition of the conductive laminate after peeling was evaluated. 〇: The coloring layer was not peeled off or was torn together with the resin film layer. ×: The coloring layer peels off from the resin film layer.

[0220] (L * a * b * ) Using a spectrophotometer (KONICA MINOLTA SPECTROPHOTOMETER CM-5), and in accordance with the measurement standard JIS Z 8722 (C spectrum 2°), the CIE colorimetric values ​​(L) were measured on the surface of the colored film layer side of the conductive laminates of the examples and comparative examples (the surface of the black colored layer side in Comparative Examples 1-4 and 1-5). * a * b* ).

[0221] (Design) Is the evaluation L? * =20~25, a * =-1~1、b * =-2 to 0. ◎:L * a * b * All fall within the above range. 〇:L * a * b * Two of them fall within the above range. ×:L * a * b * Two or more of them deviate from the above range.

[0222] (Insulation) Using a resistivity meter (Loresta MCP-T600 manufactured by Mitsubishi Chemical Corporation), the surface resistivity of the surface of the colored film layer side of the conductive laminate of the examples and comparative examples (the surface of the black colored layer side in Comparative Examples 1-4 and 1-5) was measured by contacting the probes of the four terminals. The surface resistivity was evaluated according to the following evaluation criteria. 〇:9.9×10 7 Surface resistivity above Ω / □ (overload) ×: less than 9.9 × 10 7 Surface resistivity of Ω / □

[0223] (Conductivity) Using a resistivity meter (Loresta MCP-T600, Mitsubishi Chemical Corporation), the surface resistivity of the conductive layer side of the conductive laminates in Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-5 was measured by contacting the probes of the four terminals with the surface of the conductive layer side. The resistivity was evaluated according to the following evaluation criteria. ◎: 0.6mΩ / □ or less 〇: Exceeding 0.6mΩ / □ and below 10mΩ / □ ×:More than 10mΩ / □

[0224] (Adhesive strength of conductive adhesive tape) The samples from Examples 2-1 to 2-7 and Comparative Examples 2-2 to 2-5 were cut into 25 mm wide and 100 mm long pieces, attached to an SUS plate, and subjected to reciprocating pressure once using a 2 kg roller. After being placed at 23°C and 50% RH for 1 hour, the adhesive force was measured when peeled at a speed of 300 mm / min in the 180° direction.

[0225] The results are shown in Tables 1-4.

[0226] Table 1

[0227] Table 2

[0228] Table 3

[0229] Table 4

[0230] As can be seen from Tables 1 to 4 above, the conductive laminates I to VII of the embodiments exhibit good alcohol resistance and surface insulation, and also good productivity during large-scale manufacturing. On the other hand, the conductive laminates VIII to XII of the comparative examples have poor performance in at least one of alcohol resistance, surface insulation, and productivity, making it impossible to achieve a balance. Compared to conductive laminate XI, conductive laminates I to VII have a smaller total thickness, but their CIE chromaticity values ​​are within the desired range, thus offering high design appeal and concealment due to their black color. Conductive laminates I to VII have a laminate structure having a coloring layer in a coloring film layer and a resin film layer, an adhesive layer and a metal foil in the coloring film layer stacked sequentially, thus having better surface insulation than conductive laminate XII which has a coloring layer directly disposed on a metal foil. Explanation of reference numerals in the attached figures

[0231] 1…conductive layer (metal foil), 2…adhesive layer or adhesive layer, 3…coloring film layer, 4…resin film layer, 5…coloring layer, 10…conductive laminate, 11…conductive adhesive layer, 20…conductive adhesive tape.

Claims

1. A conductive laminate, characterized in that, It has a conductive layer, an adhesive or bonding agent layer disposed on one side of the conductive layer, and a colored film layer disposed on the surface of the adhesive or bonding agent layer opposite to the conductive layer. The conductive layer is a metal foil. The colored film layer has a resin film layer and a colored layer that is in contact with the surface of the resin film layer opposite to at least the conductive layer. The coloring layer comprises a cured resin and a coloring material, and the glass transition temperature of the coloring layer is in the range of 43°C to 70°C. The cured resin is a polyester resin that is a cured product of polyester polyol and diisocyanate. The polyester polyol is a copolymer of one or more dicarboxylic acids and one or more diols. The diisocyanate is selected from at least one of aliphatic diisocyanates, adducts of the aliphatic diisocyanates, isocyanurates, biuretates, and ureocarbamates.

2. The conductive laminate according to claim 1, wherein, The surface of the colored film layer on one side of the conductive laminate, made by CIE L ＊ a ＊ b ＊ The colorimetric system specifies a brightness L. ＊ A chromaticity a is between 20 and 27. ＊ For values ​​between -2 and 2, the chromaticity b is... ＊ It is greater than -2 and less than 2.

3. The conductive laminate according to claim 1, wherein, The weight-average molecular weight of the polyester polyol is in the range of 1,000 to 400,000.

4. The conductive laminate according to claim 1 or 2, wherein, The metal foil is copper foil.

5. The conductive laminate according to claim 1 or 2, wherein, The conductive laminate contains carbon black as the coloring material.

6. The conductive laminate according to claim 1 or 2, wherein, The adhesive or bonding layer contains coloring material.

7. The conductive laminate according to claim 1 or 2, wherein, The conductive laminate is used for electromagnetic shielding or grounding purposes, both internally and externally, of electrical or electronic equipment.

8. The conductive laminate according to claim 1 or 2, wherein, The coloring layer is a black coloring layer.

9. The conductive laminate according to claim 1 or 2, wherein, The coloring layer is a white coloring layer.

10. The conductive laminate according to claim 1 or 2, wherein, The weight-average molecular weight of the polyester polyol is in the range of 1,000 to 400,000.

11. The conductive laminate according to claim 1 or 2, wherein, The dicarboxylic acid is selected from succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanoic acid, maleic acid, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, biphenyl dicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, and anhydrides or ester-forming derivatives of these dicarboxylic acids.

12. The conductive laminate according to claim 11, wherein, The naphthalene dicarboxylic acid is 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, or 2,6-naphthalene dicarboxylic acid.

13. The conductive laminate according to claim 1 or 2, wherein, The diols are selected from ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentanediol, methylpentanediol, dimethylbutanediol, butyl ethyl propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, dihydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanediol, polycaprolactone diol, dimer diol, bisphenol A, and hydrogenated bisphenol A.

14. The conductive laminate according to claim 13, wherein, The propylene glycol is 1,3-propanediol.

15. A conductive adhesive tape, characterized in that, A conductive laminate having any one of claims 1 to 14 and a conductive adhesive layer disposed on a surface of the conductive layer side of the conductive laminate.

16. The conductive adhesive tape according to claim 15, wherein, The conductive adhesive tape is used for electromagnetic shielding or grounding purposes, both internally and externally, of electrical or electronic equipment.

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