Conductive laminate and conductive adhesive tape

Abstract

To provide a conductive laminate and a conductive pressure-sensitive adhesive tape which exhibit good alcohol resistance and surface insulating properties on an outermost surface and are excellent in productivity.SOLUTION: The present invention provides the conductive laminate and the like including: a conductive layer; a pressure-sensitive adhesive layer or an adhesive layer provided on one surface of the conductive layer; and a colored film layer provided on that surface of the pressure-sensitive adhesive layer or the adhesive layer which is opposite to the conductive layer. The conductive layer is a metal foil. The colored film layer includes a resin film layer and a colored layer in contact with at least that surface of the resin film layer which is opposite to the conductive layer. The colored layer contains a resin cured product and a coloring material and has a glass transition temperature within the range of 43-70°C.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a conductive laminate and a conductive adhesive tape.

Background Art

[0002] A conductive laminate and a conductive adhesive tape provided with a conductive adhesive layer on the laminate (hereinafter, the conductive laminate and the conductive adhesive tape may be collectively referred to as a conductive laminate or the like) are used for shielding unnecessary leakage electromagnetic waves radiated from electric and electronic devices and the like, shielding harmful space electromagnetic waves generated from other electric and electronic devices, grounding for preventing electrostatic charging, and the like because of their ease of handling.

[0003] With the miniaturization and thinning of electric and electronic devices, the conductive laminate or the like is required to have a small total thickness and be thin. In addition to having high conductivity, the conductive laminate or the like is required to have insulation on one surface (the surface opposite to the surface that exhibits conductivity) in order to prevent the occurrence of short circuits due to contact with other members.

[0004] Furthermore, in recent years, electric and electronic devices have been improved in terms of appearance, internal design, display image quality, image visibility, etc. In particular, attempts have been made to improve the internal design by unifying the color of electronic components built into the device to black. Therefore, the conductive laminate used in such a part where internal design is required is required to have high surface blackness such as black design and concealment such as jet blackness and matte feeling so as to be in tune with the black of the black electronic component and give a sense of unity. In this specification, the design and blackness of the conductive laminate or the like are physical properties mainly visually recognized from the insulating surface side of the conductive laminate or the like.

[0005] For example, Patent Document 1 discloses a conductive sheet having a base substrate with metal layers formed as conductive layers on both surfaces of a resin film, a light-shielding insulating layer provided on the first main surface of the base substrate, and a conductive adhesive layer provided on the second main surface of the base substrate. In the conductive sheet disclosed in Patent Document 1, as the light-shielding insulating layer, a black-colored layer formed of an insulating resin colored with a black coloring agent is used.

[0006] Further, Patent Document 2 discloses a sheet using an adhesive tape having a colored layer on one surface and a transparent adhesive layer on the other surface of a polyethylene terephthalate film as a base substrate, with the adhesive tape laminated on the first main surface of a soft aluminum substrate as a conductive layer, and another transparent adhesive layer provided on the second main surface of the soft aluminum substrate.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

[0008] By the way, in order to prevent foreign matter from entering the interior of electrical and electronic devices, etc., the surface on the side opposite to the conductive layer side of a conductive laminate or the like may be wiped with alcohol for foreign matter removal. At this time, the alcohol resistance of the colored layer located on the outermost surface on the side opposite to the conductive layer side of the conductive laminate or the like is required so that no appearance defects occur due to the wiping.

[0009] As a method for improving the alcohol resistance of the colored layer, for example, a method of increasing the hardness of the resin constituting the colored layer is generally known (see, for example, Patent Document 3). However, when forming a colored film provided with a colored layer on the surface of a resin film serving as a base substrate, when printing a colored ink containing a resin with high hardness on the thin film base substrate, the above-mentioned colored film is likely to curl greatly, and in the production of a conductive laminate or the like, in the lamination with a conductive layer, particularly a thin metal layer, problems such as the occurrence of wrinkles are likely to occur, resulting in a low yield of good products and other productivity problems. The above problems are particularly prominent when continuously manufacturing a conductive laminate on a line or when manufacturing a large-sized conductive laminate.

[0010] Further, in the method of directly forming a colored layer containing a hard resin on the surface of the conductive layer, it is necessary for the colored layer alone to exhibit insulation, and it is difficult to ensure sufficient surface insulation with a thin colored layer. Also, in order to function as a colored layer, it is necessary to increase the addition amount of the colorant, and the insulation of the colored layer may be reduced due to the conductivity of the colorant.

[0011] Therefore, in a conductive laminate or the like, there has been a problem that it is difficult to achieve both good alcohol resistance and surface insulation, as well as an improvement in the productivity of the conductive laminate or the like.

Summary of the Invention

Problems to be Solved by the Invention

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

Means for Solving the Problems

[0013] As a result of intensive studies to achieve the above object, the present inventors have found that the object of the present invention can be achieved by a conductive laminate having a colored film layer provided with a colored layer having a specific glass transition temperature, and a conductive adhesive tape provided with an adhesive layer on the conductive laminate, and have completed the present invention.

[0014] That is, the present invention provides a conductive laminate having a conductive layer, an adhesive layer or an adhesive layer provided on one surface of the conductive layer, and a colored film layer provided on a surface of the adhesive layer or the adhesive layer opposite to the conductive layer, wherein the conductive layer is a metal foil, the colored film layer has a resin film layer and a colored layer in contact with at least a surface of the resin film layer opposite to the conductive layer, the colored layer contains 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] The present invention also provides a conductive adhesive tape having the above-described conductive laminate and a conductive adhesive layer provided on a surface of the conductive laminate on the conductive layer side. To provide.

Advantages of the Invention

[0016] The conductive laminate of the present invention and the conductive adhesive tape provided with the conductive laminate can exhibit good alcohol resistance and surface insulation properties on the outermost surface opposite to the conductive layer, and further have excellent productivity. Therefore, the conductive laminate and the conductive adhesive tape of the present invention can be suitably applied to the protection of circuit components of portable electronic devices that require miniaturization, thinning, high alcohol resistance, and surface insulation properties.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0018] Hereinafter, the conductive laminate and the conductive adhesive tape of the present invention will be described respectively.

[0019] I. Conductive laminate The conductive laminate of the present invention has a conductive layer, an adhesive or adhesive layer provided on one surface of the conductive layer, and a colored film layer provided on the surface of the adhesive layer or adhesive layer opposite to the conductive layer. The conductive layer is a metal foil, and the colored film layer has a resin film layer and a colored layer in contact with at least the surface of the resin film layer opposite to the conductive layer. The colored layer contains 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.

[0020] FIG. 1 is a schematic cross-sectional view showing an example of the conductive laminate of the present invention. The conductive laminate 10 of the present invention illustrated in FIG. 1 has a conductive layer 1 which is a metal foil, an adhesive layer or an adhesive layer 2 provided on one surface (the first main surface) of the conductive layer 1, and a colored film layer 3 provided on the adhesive layer or the adhesive layer 2. The colored film layer 3 has a resin film layer 4 and a colored layer 5 in contact with the surface of the resin film layer 4 opposite to the conductive layer 1. The colored layer 5 contains a cured resin and a colorant and has a glass transition temperature within a predetermined range. The resin film layer 4 becomes one of the outermost surface (the surface on the colored film layer side) layers of the conductive laminate 10 of the present invention.

[0021] The conductive laminate of the present invention has a layer structure in which a conductive layer formed of a metal foil, an adhesive or adhesive layer, and a colored film layer having a desired configuration are laminated in this order, and since the colored layer has a glass transition temperature within a predetermined range, it can exhibit good alcohol resistance and high surface insulation on the surface on the colored film layer side. Further, in the manufacturing process of the conductive laminate of the present invention, wrinkles or the like are less likely to occur when the colored film layer and the metal foil are bonded together, and it can be manufactured with high productivity.

[0022] The conductive laminate of the present invention has a structure in which a colored film layer is provided on one surface (the first main surface) of a metal foil that is a conductive layer via an adhesive layer or an adhesive agent layer. Among the surfaces of the conductive laminate of the present invention, the surface located on the side of the one surface of the conductive layer (the surface on which the colored film layer is provided via the adhesive layer or the adhesive agent layer) is referred to as the colored film side surface of the conductive laminate, and the surface located on the side of the surface of the conductive layer opposite to the one surface (the second main surface) may be referred to as the conductive layer side surface of the conductive laminate. Further, in the conductive laminate of the present invention, usually, one outermost surface layer is a colored film layer and the other outermost surface layer is a conductive layer.

[0023] Hereinafter, the details of the conductive laminate of the present invention will be described.

[0024] 1. Conductive layer The conductive layer in the present invention is a layer that bears the conductivity of the conductive laminate. In the present invention, the conductive layer is a metal foil. Here, the metal foil is a layer composed of a metal and is a foil with the metal having a micro-level thickness. The conductive laminate of the present invention can exhibit high electromagnetic wave shielding properties because the conductive layer is a metal foil as compared with a graphite sheet, a metal vapor deposition film, etc.

[0025] The metal foil is not particularly limited as long as it is a foil composed of a desired metal material, and examples thereof include copper foil, aluminum foil, nickel foil, stainless steel foil, etc. Among them, copper foil is most preferable from the viewpoint of excellent conductivity and electromagnetic wave shielding characteristics.

[0026] The copper foil may be an electrolytic copper foil or a rolled copper foil, but the electrolytic copper foil is most excellent because it has excellent adhesiveness to the adhesive layer or the adhesive agent layer bonded to the conductive layer and the adhesive layer disposed on the surface (the second main surface) opposite to the colored film layer side of the conductive layer when used as the conductive adhesive tape described later.

[0027] The thickness of the conductive layer is not particularly limited, but the thickness is preferably 3 μm or more, more preferably 5 μm or more, and the above thickness is 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 exhibited even if the total thickness of the conductive laminate is small. If the thickness of the conductive layer exceeds the above range, it may be difficult to make the conductive laminate thinner. On the other hand, if it is less than the above range, it may be difficult to obtain conductivity and electromagnetic shielding properties.

[0028] The ten-point average surface roughness Rz of the conductive layer is preferably 2.0 μm or less. When the surface roughness Rz of the conductive layer is within the above range, sufficient adhesiveness can be exhibited with respect to the adhesive layer or the adhesive agent layer bonded to the conductive layer, and the conductive adhesive layer or the insulating adhesive layer of the thin film bonded to the second main surface of the conductive layer when forming the conductive adhesive tape described later. More preferably, the ten-point average surface roughness Rz of the conductive layer is 0.01 μm or more and 0.1 μm or more, and the above Rz is 2.0 μm or less, 1.5 μm or less, 1.3 μm or less, 1.1 μm or less, 0.9 μm or less.

[0029] Also, the arithmetic average 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 still more preferably 0.05 μm or more and 0.3 μm or less. By setting the arithmetic average roughness Ra of the conductive layer within the above range, sufficient adhesiveness can be exhibited with respect to the adhesive layer or the adhesive agent layer bonded to the conductive layer, and the adhesive layer of the thin film bonded to the surface (second main surface) opposite to the colored film layer side of the conductive layer when forming the conductive adhesive tape described later.

[0030] The ten-point average surface roughness Rz and the arithmetic average roughness Ra of the conductive layer refer to the values specified in JIS B0601:2013. Using HANDYSURF+ manufactured by Tokyo Seimitsu Co., Ltd., surface measurements are performed on any three locations (each in the range of 50 μm in length × 50 μm in width) on the surface of the conductive layer, and the average value of the three points obtained from the measurement is taken as the ten-point average surface roughness Rz and the arithmetic average roughness Ra of the conductive layer.

[0031] 2. Adhesive layer or bonding agent layer The adhesive or bonding agent layer in the present invention is a layer disposed between the conductive layer and the colored film layer and bonding the conductive layer and the colored film layer, and may be an adhesive layer or a bonding agent layer. In some cases, the adhesive layer or bonding agent layer that joins the conductive layer and the colored film layer may be referred to as a joining layer for explanation.

[0032] When the joining layer is an adhesive layer, the composition of the adhesive layer is not particularly limited. For example, known adhesive compositions such as (meth)acrylic-based adhesive compositions, polyester-based adhesive compositions, styrene-diene block copolymer-based adhesives, vinyl alkyl ether-based adhesive compositions, polyamide-based adhesive compositions, fluorine-based adhesive compositions, creep property-improved adhesive compositions, and radiation-curable adhesive compositions can be appropriately selected and used. The adhesive components can be used alone or in combination of two or more.

[0033] Also, when the joining layer is a bonding agent layer, the composition of the bonding agent layer is not particularly limited. For example, general-purpose adhesives such as vinyl acetate resin-based adhesives, ethylene-vinyl acetate copolymer resin (EVA)-based adhesives, α-olefin (isobutene-maleic anhydride resin)-based adhesives, acrylic resin-based adhesives, styrene-butadiene rubber-based adhesives, vinyl chloride resin-based adhesives, chloroprene rubber-based adhesives, nitrile rubber-based adhesives, recycled rubber-based adhesives, SBR-based adhesives, urethane resin-based adhesives, silicone resin-based adhesives, modified silicone resin-based adhesives, epoxy-modified silicone resin-based adhesives, epoxy-based adhesives, and silylated urethane resin-based adhesives can be appropriately selected and used. The adhesive components can be used alone or in combination of two or more.

[0034] Among these, since it becomes possible to make the adhesion between the colored film layer and the conductive layer better, it is preferable that the joining layer is an adhesive layer, and it is more preferable that the adhesive layer contains a (meth)acrylic adhesive composition as an adhesive component because high adhesion reliability can be obtained. The (meth)acrylic adhesive composition essentially contains a (meth)acrylic polymer (acrylic copolymer) as a base polymer, and can contain appropriate additives such as a crosslinking agent, a tackifier, a softening agent, a plasticizer, a filler, an antioxidant, and a coloring agent as required.

[0035] (Meth)acrylic polymers are polymers mainly composed of (meth)acrylic acid alkyl ester monomers, and are prepared by using monomers copolymerizable with (meth)alkyl esters (copolymerizable monomers) as required. That is, the acrylic polymer may be a homopolymer or a copolymer.

[0036] Examples of the (meth)acrylic acid alkyl ester that constitutes the (meth)acrylic polymer include (meth)acrylic acid C1-20 alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate [preferably (meth)acrylic acid C4-18 alkyl (linear or branched alkyl) ester]. The (meth)acrylic acid alkyl ester can be appropriately selected according to the intended adhesiveness and the like. The (meth)acrylic acid alkyl ester can be used alone or in combination of two or more. Those containing 30% or more of butyl acrylate are preferred because they are excellent in adhesiveness and heat resistance.

[0037] In addition, examples of the copolymerizable monomer copolymerizable with the above (meth) alkyl ester include carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, or anhydrides thereof; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; aromatic vinyl compounds such as styrene and substituted styrene; cyano group-containing monomers such as acrylonitrile; olefins such as ethylene, propylene, and butadiene; vinyl esters such as vinyl acetate; vinyl chloride; amide group-containing monomers such as acrylamide, methacrylamide, N-vinylpyrrolidone, and N,N-dimethyl (meth) acrylamide; hydroxyl group-containing monomers such as (meth) acrylic acid hydroxyalkyl and glycerin dimethacrylate; amino group-containing monomers such as (meth) acrylic acid aminoethyl and (meth) acryloylmorpholine; imide group-containing monomers such as cyclohexyl maleimide and isopropyl maleimide; epoxy group-containing monomers such as (meth) acrylic acid glycidyl and (meth) acrylic acid methyl glycidyl; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate, and polyfunctional copolymerizable monomers (polyfunctional 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. The copolymerizable monomer may be used alone or in combination of two or more. As the copolymerizable monomer, a modifying monomer having a functional group such as a carboxyl group can be preferably used. Those containing 0.5 to 4.0% of acrylic acid are preferred because they are excellent in adhesiveness and heat resistance.

[0038] The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 300,000 or more, 500,000 or more, 600,000 or more, and the above weight average molecular weight (Mw) is preferably 1,200,000 or less, 1,000,000 or less, 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. When the weight average molecular weight (Mw) of the (meth)acrylic polymer is within the above range, the black adhesive layer can exhibit good adhesiveness and heat resistance to the conductive layer and the insulating portion even if it is thin.

[0039] The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC). More specifically, as a GPC measuring device, using "SC8020" manufactured by Tosoh Corporation, it can be measured and obtained under the following GPC measurement conditions in terms of polystyrene conversion value. (GPC measurement conditions) · Sample concentration: 0.5 wt% (tetrahydrofuran solution) · Sample injection volume: 100 μL · Eluent: Tetrahydrofuran (THF) · Flow rate: 1.0 mL / min · Column temperature (measurement temperature): 40 °C · Column: "TSKgel GMHHR-H" manufactured by Tosoh Corporation · Detector: Differential refractive index

[0040] In addition, the weight average molecular weight (Mw) in this specification is taken as the value measured by the above method and conditions unless otherwise specified.

[0041] In order to improve the adhesive force, it is also preferable that the adhesive layer contains an adhesion - imparting resin. Since the adhesive layer contains an adhesion - imparting resin, the tensile strength and the tensile breaking strength can be increased. Therefore, by appropriately adding an adhesion - imparting resin according to the (meth)acrylic polymer used, the tensile strength and the tensile breaking strength of the conductive laminate of the present invention can be adjusted. Examples of the adhesion - imparting resin include rosin - based resins such as rosin and ester compounds of rosin; terpene - based resins such as diterpene polymers and α - pinene - phenol copolymers; petroleum resins such as aliphatic (C5 - based) and aromatic (C9) resins; and other styrene - based resins, phenol - based resins, xylene resins, etc. The adhesion - imparting resin may be used alone or in combination of two or more kinds.

[0042] Among them, when the above - mentioned adhesive layer contains a (meth)acrylic polymer having n - butyl (meth)acrylate (in other words, n - butyl (meth)acrylate) as a main monomer component, it is preferable to contain a mixture of a rosin - based resin and a styrene - based resin. This is because by using these two kinds of adhesion - imparting resins in combination, it becomes easier to achieve both the thinning of the adhesive layer and the adhesive force.

[0043] In order to increase the initial adhesive force, it is preferable that the above - mentioned adhesive layer contains an adhesion - imparting resin that is liquid at room temperature. Examples of the adhesion - imparting resin that is liquid at room temperature include liquid resins of adhesion - imparting resins that are solid at room temperature, process oils, polyester - based plasticizers, and low - molecular - weight liquid rubbers such as polybutene. Particularly, terpene - phenol resins are preferable. Commercially available products include YP - 90L manufactured by Yasuhara Chemical Co., Ltd. The addition amount of the adhesion - imparting resin is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the (meth)acrylic polymer.

[0044] The above - mentioned adhesion - imparting resin is preferably contained in the range of 10 parts by mass to 70 parts by mass, more preferably in the range of 20 parts by mass to 60 parts by mass, with respect to 100 parts by mass of the (meth)acrylic polymer. By setting the amount of the adhesion - imparting resin within the above - mentioned range, the adhesive force of the adhesive layer can be improved.

[0045] The gel fraction of the adhesive layer is not particularly limited, but 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 adhesiveness. Among them, the gel fraction of the adhesive layer is more preferably 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 obtained by immersing the cured adhesive layer in toluene, measuring the mass of the insoluble matter remaining after standing for 24 hours, and expressing it as a percentage of the original mass. Gel fraction (% by mass) = [(mass of the adhesive layer after toluene immersion) / (mass of the adhesive layer before toluene immersion)] × 100

[0047] The storage modulus of the adhesive layer at 25°C is 1×10 4 or more and 5×10 5 Pa or less, preferably 3×10 4 or more and 1×10 5 Pa or less. By setting the storage modulus of the adhesive layer within the above range, even if it is a thin film, it is easy to highly balance wettability (initial tack), adhesiveness, and processability.

[0048] The storage modulus of the adhesive layer at 25°C can be measured by a viscoelasticity tester. More specifically, it can be obtained by measuring under the following measurement conditions using a viscoelasticity tester (ARES 2kSTD) manufactured by TA Instruments Japan. · Test piece thickness: 2 mm · Frequency: 1 Hz · Compressive load: 40 to 60 g

[0049] In this specification, unless otherwise noted, the storage modulus of the adhesive layer at 25°C is the value measured by the above method and conditions.

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

[0051] The adhesive layer or the bonding agent layer may be colorless and transparent or colored, but from the viewpoint of enhancing the designability of the conductive laminate, it is preferably colored, among which a dark color is preferred, and black is more preferred. By the adhesive layer or the bonding agent being colored, especially black, a synergistic effect between the color exhibited by the colored layer and the color exhibited by the adhesive layer or the bonding agent layer enables high designability and concealability to be exhibited even in a thin conductive laminate. In addition, in order for the colored layer alone to exhibit designability and concealability, it is necessary to increase the thickness of the colored layer. On the other hand, by coloring the adhesive layer or the bonding agent layer, an increase in the total thickness of the conductive laminate due to an improvement in designability and concealability can be suppressed.

[0052] When the adhesive layer or the bonding agent layer is colored, the adhesive layer or the bonding agent layer contains a colorant. The colorant is not particularly limited, and pigments, dyes, etc. can be used. When the adhesive layer or the bonding agent layer exhibits black, examples of the black colorant contained in the adhesive layer or the bonding agent layer include organic black pigments, inorganic black pigments, black dyes, etc. The black colorant can be used alone or in combination of two or more. Also, the black colorant preferably has low insulation or low conductivity. This is because the conductivity of the adhesive layer or the bonding agent layer can be lowered to increase the surface insulation of the conductive laminate.

[0053] Examples of inorganic black pigments include carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite, magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complexes, composite oxide-based black pigments, etc. Examples of organic black pigments include aniline black, azo pigments, anthraquinone-based organic black dyes, etc. Among them, since the color of the conductive laminate is likely to assimilate with the color of the members used in electrical and electronic devices, it has excellent light-shielding properties and dispersibility, and in particular, high concealability due to the overlap of the black colored layer and the adhesive layer or the bonding agent layer can be exhibited. Therefore, the above black colorant is preferably carbon black.

[0054] The content of the colorant in the adhesive layer or the bonding agent layer is not particularly limited, and it can be an amount that can exhibit a desired surface design property or concealment property due to the overlap with the colored layer. For example, in the total amount (100% by mass) of the adhesive layer or the 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 even more preferably 10% by mass or more and 35% by mass or less. When the content of the colorant in the adhesive layer or the bonding agent layer is within the above range, even if it is thin, the insulating property of the adhesive layer or the bonding agent layer can be exhibited, and the adhesiveness to the colored film layer or the conductive layer can be exhibited. Furthermore, the surface design property and concealment property due to the overlap with the colored layer can be enhanced.

[0055] The thickness of the adhesive layer or the bonding agent layer is preferably 0.5 μm or more, 1 μm or more, 1.5 μm or more, and the above thickness is preferably 5 μm or less, 3 μm or less, 2.5 μm or less. More specifically, the thickness of the adhesive layer or the bonding agent 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 the bonding agent layer within the above range, it becomes easier to balance the adhesive strength and thinness as a conductive laminate. In particular, when the conductive laminate of the present invention is used for electromagnetic shielding for electronic components, it becomes easier to balance the required adhesive strength and thinness. Further, when the adhesive layer or the bonding agent layer contains a colorant, the color density of the adhesive layer or the bonding agent layer alone is improved, and the surface design property and concealment property due to the overlap with the colored layer can be enhanced.

[0056] The adhesive layer or the bonding agent layer preferably has low conductivity or exhibits insulating properties. This is because by reducing the conductivity of the adhesive layer or the bonding agent layer, the insulating property of the surface of the colored film layer side of the conductive laminate can be enhanced. Specifically, the surface resistivity of the adhesive layer or the bonding agent layer is preferably 1×10 9 Ω / □ or more, more preferably 1×10 10 Ω / □ or more, and even more preferably 1×10 11More preferably, it is Ω / □ or more. When the surface resistivity of the pressure-sensitive adhesive layer or the adhesive layer is within the above range, the pressure-sensitive adhesive layer or the adhesive layer can exhibit high insulation properties, and the insulation properties exhibited by the colored film layer can be further enhanced. Thereby, the conductive laminate of the present invention can exhibit higher insulation properties on the surface side of the colored film layer. Note that, although the larger the surface resistivity of the pressure-sensitive adhesive layer or the adhesive layer is, the better, generally it is 1×10 18 Ω / □ or less, 1×10 16 Ω / □ or less, 1×10 14 Ω / □ or less, 1×10 12 Ω / □ or less.

[0057] The surface resistivity of the pressure-sensitive adhesive layer or the adhesive layer refers to the value measured according to JIS-K6911, and can be measured by applying a voltage of 500 V to the pressure-sensitive adhesive layer or the adhesive layer using a resistivity meter (Advantest digital ultra-high resistance / micro current meter R8340, TR42 box).

[0058] When the pressure-sensitive adhesive layer or the adhesive layer is colored, the hiding power of the pressure-sensitive adhesive layer or the adhesive layer is not particularly limited as long as it can exhibit the desired surface colorability due to the overlap with the colored layer described later, but it is preferably 20% or more, more preferably 30% or more, and even more preferably 40% or more. Also, the higher the hiding power of the pressure-sensitive adhesive layer or the adhesive layer is, the better, and the upper limit can be 100%. By setting the hiding power of the pressure-sensitive adhesive layer or the adhesive layer within the above range, it is possible to suppress a decrease in the design property and hiding property of the surface of the colored film layer side of the conductive laminate due to the influence of the color of the conductive layer, particularly the blackness and hiding property of the surface of the conductive laminate due to the influence of the color of the conductive layer when a black ink layer is used as the colored layer.

[0059] The hiding rate of the adhesive layer or the bonding agent layer can be measured by the following method. Affix the adhesive layer or the bonding agent layer to the white surface and the black surface of a hiding rate test paper (manufactured by Nippon Test Panel Co., Ltd.), and measure the Y value indicating brightness among the three stimulus values of the adhesive layer or the bonding agent layer affixed to the white surface and the black surface by the color measurement method specified in JIS-Z-8722. Use a colorimetric gloss meter "CM-3500d" (manufactured by Minolta Co., Ltd.) and measure for standard light C in a 2-degree field of view. By applying the measured Y value to the following formula, the hiding rate can be measured. Hiding rate (%) = (Y value of the adhesive layer or the bonding agent layer affixed to the black surface / Y value of the adhesive layer or the bonding agent layer affixed to the white surface) × 100%

[0060] The adhesive layer or the bonding agent layer can be formed by coating an adhesive or a bonding agent on a resin film layer of a conductive layer or a colored film layer. Examples of the coating method include gravure coating, comma coating, bar coating, die coating, lip coating, screen coating, etc. Among them, gravure coating is preferable for coating a thin film, and microgravure coating is most preferable.

[0061] 3. Colored film layer The colored film layer in the present invention is a layer provided on one surface (the first main surface) of the conductive layer via an adhesive layer or a bonding agent layer. The colored film layer in the present invention has a resin film layer and a colored layer provided so as to be in contact with at least the surface of the resin film layer opposite to the conductive layer. That is, in the colored film layer, the colored layer is directly formed on at least the surface of the resin film layer opposite to the conductive layer without any other layer intervening. The colored layer in the colored film layer contains a resin cured product and a coloring material, and the glass transition temperature of the colored layer is within a predetermined range.

[0062] By having the colored film layer with the above-described characteristics on the outermost surface, the alcohol resistance of the side surface of the colored film layer can be improved. Further, since the colored film layer has a laminated structure of a resin film layer and a colored layer, while expressing the design property and concealment property by the colored layer, even if it is thin, good insulation can be expressed in the entire colored film layer.

[0063] In the colored film layer, the colored layer may be directly disposed on at least the surface of the resin film layer opposite to the conductive layer, or the colored layer may be directly disposed on both surfaces of the resin film layer. That is, the colored film layer may have a first colored 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 colored layer in contact with the surface on the conductive layer side (the second surface of the resin film layer).

[0064] Also, in the colored film layer, the colored layer disposed on the first surface of the resin film layer may be a single layer or a multilayer body having a multilayer structure of two or more layers by multi-color printing or the like. The same applies to the second surface of the resin film layer. When the colored layer is a multilayer body, each layer constituting the multilayer body is laminated in direct contact without interposing another layer.

[0065] (1) Resin film layer The resin film layer constituting the colored film layer in the present invention is not particularly limited, and examples thereof include known resin films exhibiting insulation properties. Specifically, polyester films, polyimide films, polyamide films, polyurethane films, polyolefin films, and the like can be mentioned. Among them, polyester films or polyimide films are preferred because they are thin and have good insulation properties, are difficult to tear, and are easy to exhibit strength. Polyester films are particularly preferred because they can be made thinner and have excellent insulation properties.

[0066] The thickness of the resin film layer is not particularly limited as long as it can exhibit the desired insulation properties, but it can preferably be 1 μm or more, 1.5 μm or more, or 2 μm or more. Also, the above thickness can preferably be 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, more preferably 1 μm or more and 6 μm or less, and most preferably 1.5 μm or more and 2.5 μm or less. This is because it is easy to exhibit high insulation properties when the thickness of the resin film layer is within the above range. Also, when the thickness of the resin film layer is within the above range, the thickness of the colored film layer and the total thickness of the conductive laminate can be reduced, and in addition to improving alcohol resistance, surface insulation properties, and productivity, thinning of the conductive laminate can be achieved.

[0067] The resin film layer may be subjected to an easy adhesion treatment in order to enhance the adhesion to the colored layer. The type of the easy adhesion treatment is not particularly limited, and known treatments can be applied. For example, surface treatments such as corona treatment or a primer layer may be provided.

[0068] (2) Colored layer The colored layer constituting the colored film layer in the present invention includes a cured resin and a coloring material, and is a layer having a glass transition temperature within a predetermined range. The colored layer is in direct contact with the surface of the resin film layer. In the conductive laminate of the present invention, usually, the colored layer provided on the surface of the colored film layer opposite to the conductive layer side of the resin film layer can be located on the outermost surface of the colored film side surface of the conductive laminate.

[0069] The colored layer in the present invention has a glass transition temperature in the range of 43°C to 70°C. When the glass transition temperature of the colored layer is within the above predetermined range, good alcohol resistance and surface insulation properties can be achieved simultaneously. Also, when laminating the colored film layer and the conductive layer via an adhesive layer or an adhesive agent layer, the occurrence of wrinkles or the like due to curling or the like of the colored film layer can be suppressed, and productivity can be enhanced.

[0070] In addition, when a colored ink containing a resin with high hardness is printed on a resin film of a thin film to form a colored layer in order to enhance the alcohol resistance of the surface, sufficient adhesion between the colored layer and the resin film cannot be obtained, and delamination tends to occur easily 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 of the colored layer formed on the resin film layer, it is possible to improve the alcohol resistance and enhance the adhesion between the resin film layer and the colored layer. As a result, a conductive laminate with high interlayer adhesion can be obtained.

[0071] The glass transition temperature of the colored layer may be within the range of 43°C to 70°C. Among them, the glass transition temperature of the colored layer is preferably within the range of 45 to 68°C, and particularly preferably within the range of 50°C to 65°C. This is because the ethanol resistance can be further improved, and when a colored ink is coated on a thin resin film layer to form a colored layer in the formation of the colored film, the occurrence of curl of the colored film can be more effectively suppressed, the productivity of the conductive laminate can be further enhanced, and the compatibility between ethanol resistance and productivity is more excellent. In addition, since the colored film layer can be made thinner by the above manufacturing method, the thinning of the conductive laminate can also be achieved. The glass transition temperature is a value measured using DSC in accordance with ISO 3146.

[0072] The glass transition temperature of the colored layer is adjusted by the glass transition temperature of the cured resin contained in the colored layer, the blending ratio of the cured resin and the coloring material, etc. Among them, since the glass transition temperature of the cured resin greatly contributes to the glass transition temperature of the colored layer, it is mainly possible to adjust by the glass transition temperature of the cured resin.

[0073] <Composition of the colored layer> The colored layer contains a cured resin and a coloring material. The colored layer can be formed, for example, by applying a colored ink containing a two-component curable resin containing a main agent and a curing agent and a coloring material to one surface of a resin film layer and drying it. The colored layer is a layer formed by a cured product of the colored ink. The cured product of the two-component curable resin containing the main agent and the curing agent corresponds to the cured resin in the colored layer.

[0074] -Cured resin- The cured resin contained in the colored layer may be any resin that can make the glass transition temperature of the colored layer fall within a predetermined 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 to 68°C, and particularly preferably in the range of 50°C to 65°C. The glass transition temperature is a value measured using DSC in accordance with ISO 3146. The glass transition temperature of the cured resin can be appropriately adjusted, for example, by adjusting the blending ratio of the main agent and the curing agent of the two-component curable resin, which is the precursor of the cured resin, and the degree of crosslinking. The cured resin is not particularly limited as long as it exhibits insulation and its glass transition temperature falls within the above range, and a cured product of a general-purpose resin can be used. For example, a cured product of a polyester-based resin can be mentioned. Among them, the cured resin is a cured product of a resin composition containing a polyol component mainly composed of polyester polyol and an isocyanate component mainly composed of a polyfunctional isocyanate (a cured product of a polyester-based resin containing the above polyol component and isocyanate component )This is because good alcohol resistance, surface insulation properties, and improved productivity of the conductive laminate can be achieved by combining the colored layer and the resin film layer. Further, the colored layer containing the cured resin of the above composition has particularly good adhesion to the resin film layer containing a polyester-based resin cured product. Note that the main component refers to the component with the highest content ratio among the contained components. For example, the polyol component having polyester polyol as the main component means that polyester polyol is contained in the largest amount in the polyol component. The same applies to the isocyanate component having polyfunctional isocyanate as the main component. Among them, it is preferable that the cured resin is a cured product of a reaction between a polyol component and an isocyanate component, the polyol component is a polyester polyol, and the isocyanate component is a polyfunctional isocyanate, that is, a cured product of a polyester-based resin.

[0075] When the cured resin of the colored layer is a cured product of a resin composition containing a polyol component having polyester polyol as the main component and an isocyanate component having polyfunctional isocyanate as the main component, the colored layer can be formed using a two-component curable resin containing the polyol component having polyester polyol as the main component as the main agent and the isocyanate component having polyfunctional isocyanate as the main component as the curing agent, and a colored ink containing a coloring material.

[0076] (Polyol component) When the colored layer contains a cured product of a resin composition including a polyol component mainly composed of a polyester polyol and an isocyanate component mainly composed of a polyfunctional isocyanate, the molecular weight of the polyester polyol contained in the polyol component is not particularly limited, but preferably within the range of 1,000 to 400,000 in terms of mass average molecular weight. When the mass average molecular weight of the polyester polyol is 1,000 or more, the printing suitability, coating suitability, and alcohol resistance of the resulting cured resin tend to be suitable. By setting it to 400,000 or less, the drying property and blocking resistance tend to be improved. The mass average molecular weight of the polyester polyol is more preferably within the range of 2,000 to 350,000, and even more preferably within the range of 3,000 to 300,000.

[0077] The above mass average molecular weight is in terms of standard polystyrene conversion by gel permeation chromatography (GPC). As measurement conditions, a column of TSKgel GMHXL [manufactured by Tosoh Corporation] is used, the column temperature is 40°C, the eluent is tetrahydrofuran, the flow rate is 1.0 mL / min, and TSK standard polystyrene is used as the standard polystyrene.

[0078] The polyester polyol is a compound having two or more hydroxyl groups. Examples of such polyester polyols include polyester polyols obtained by reacting one or more polybasic acids with one or more polyhydric alcohols, polyester polyols obtained by ring-opening polymerization of cyclic ester compounds such as ε-caprolactone, and polyester polyols obtained by copolymerizing these.

[0079] As the polybasic acid for preparing the polyester polyol, any known raw material can be used. Examples of the polybasic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid , maMaleic acid, 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, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, and anhydrides or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids, polybasic acids such as dimer acid can be used alone or as a mixture of two or more. The above dimer acid is a product of the Diels-Alder type dimerization reaction of C18 unsaturated fatty acids such as oleic acid and linoleic acid, and various products such as those obtained by adding hydrogen to the unsaturated bond to saturate it are commercially available. A typical one consists of 0 to 5% by mass of C18 monocarboxylic acid, 70 to 98% of C36 dimer acid, and 0 to 30% by mass of C54 trimer acid.

[0080] As the polyhydric alcohol for preparing the polyester polyol, any known raw material can be used. Specific examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, triethylene glycol, polycaprolactone diol, dimer diol, bisphenol A, hydrogenated bisphenol A and other glycols; polyesters obtained by ring-opening polymerization reaction of cyclic ester compounds such as propiolactone, butyrolactone, ε-caprolactone, δ-valerolactone, β-methyl-δ-valerolactone; polyhydric alcohols such as polyethers obtained by addition polymerization of one or more of compounds having two active hydrogen atoms such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and one or more of monomers such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclohexylene by a conventional method. These various polyhydric alcohols can be used alone or as a mixture of two or more kinds.

[0081] The polyol component only needs to contain the polyester polyol as the main component, and it may only contain the polyester polyol. If it is possible to make the glass transition temperature of the colored layer within a predetermined range, in addition to the polyester polyol, it may also contain one or more polyols other than the polyester polyol.

[0082] (Isocyanate component) When the colored layer contains a cured product of a resin composition containing a polyol component mainly composed of a polyester polyol and an isocyanate component mainly composed of a polyfunctional isocyanate, the isocyanate component is a component that reacts with the polyol component mainly composed of the above-mentioned polyester polyol and is mainly composed of a polyfunctional isocyanate.

[0083] The polyfunctional isocyanate may be one having two or more isocyanate groups in one molecule, and among them, a diisocyanate having two isocyanate groups can be preferably used. Specifically, as the polyfunctional isocyanate, aromatic diisocyanates (diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, tolylene diisocyanate, prepolymers of low molecular weight glycols and the above aromatic diisocyanates, etc.), aliphatic diisocyanates (1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, prepolymers of low molecular weight glycols such as ethylene glycol and propylene glycol and the above aliphatic diisocyanates, etc.), alicyclic diisocyanates (isophorone diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, methylcyclohexylene diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, prepolymers of low molecular weight glycols and the above alicyclic diisocyanates, etc.) and mixtures of two or more of these, adducts of the above diisocyanates and polyols, isocyanurate bodies, biuret bodies, allophanate bodies, etc. of the above diisocyanates can be mentioned. Among them, aliphatic or alicyclic diisocyanates, and their adducts, isocyanurate bodies, biuret bodies, or allophanate bodies have less curl due to curing shrinkage and are suitable for use in thin film films.

[0084] The isocyanate component may contain one type of polyfunctional isocyanate or may contain two or more types of polyfunctional isocyanates. Further, the isocyanate component only needs to contain a polyfunctional isocyanate as a main component, and may contain other isocyanates as long as the glass transition temperature of the colored layer can be made within a predetermined range.

[0085] The glass transition temperature of the resin cured product can be realized by appropriately combining the blending ratios of the polyol component and the isocyanate component, etc. The blending ratio of the polyol component (main agent) mainly composed of polyester polyol and the isocyanate component (curing agent) mainly composed of polyfunctional isocyanate can be appropriately adjusted according to the hydroxyl value of the polyester polyol which is the main component of the main agent and the number of isocyanate groups of the polyfunctional isocyanate. For example, it is preferable to blend so that the ratio of the hydroxyl group of the polyol component to the isocyanate group of the isocyanate component (hydroxyl group / isocyanate group) is 1 / 0.5 to 1 / 10 (equivalent ratio), and more preferably 1 / 0.6 to 1 / 5.

[0086] (Others) The content of the resin cured product in the colored layer may be appropriately adjusted according to the use, etc., and is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, and still more preferably 50 to 65% by mass in the colored layer. This is because the glass transition temperature can be made within a predetermined range and the alcohol resistance becomes good. In addition, the content in the colored layer is synonymous with the content in the solid content of the colored ink forming the colored layer. Further, the resin cured product in the colored layer may be one type or two or more types may be contained.

[0087] -Coloring material- As the coloring material, known and commonly used pigments and dyes that do not contain halogen can be used, and they can be appropriately selected according to the color exhibited by the coloring layer. For example, in the case of black, the black coloring agent described in the item of the above adhesive layer or pressure-sensitive adhesive layer, especially carbon black; in the case of white, titanium oxide, calcium carbonate, barium sulfate; in the case of yellow, yellow iron oxide; in the case of red, red iron oxide; in the case of blue, cyanine blue; in the case of silver, aluminum powder; in the case of pearl, mica titanium powder are preferable in terms of weather resistance, heat resistance, and dispersibility in the ink resin. Among them, carbon black is preferable because the color of the conductive laminate is likely to assimilate with the color of the members used in electric and electronic devices and it has excellent hiding properties.

[0088] The addition amount of the coloring material may be appropriately adjusted according to the use and the like, and it is preferably contained in the range of 10 to 70% by mass in the coloring layer. More preferably, the content of the coloring material in the coloring layer is 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 hiding properties can be realized, and if it is 70% by mass or less, suitable dispersibility and adhesion to the resin film can be realized. Note that the content in the coloring layer is the same as the content in the solid content of the coloring ink forming the coloring layer.

[0089] -Optional Component- The coloring layer and the coloring ink forming the coloring layer may contain any material. Examples of the above-mentioned optional materials include additives contained in general-purpose inks such as dispersants such as cellulose-based resins, blocking agents, and crosslinking accelerators such as dibutyltin.

[0090] Also, the coloring layer may contain a resin other than the above-mentioned cured resin as long as the effects of the present invention are not impaired. Among the resins other than the coloring material contained in the coloring layer, the proportion of the cured resin is preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably not substantially containing a resin other than the above-mentioned cured resin.

[0091] <Configuration of Coloring Layer> The thickness of the colored layer is not particularly limited, but it 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 setting the thickness to 1 μm or more, suitable design properties can be realized by the colored layer. In addition, since the colored layer can firmly adhere to a thin resin film that is difficult to perform adhesion treatment such as corona treatment, the interlayer adhesion of the entire colored film layer and the conductive laminate can be enhanced. On the other hand, by setting the thickness to 4 μm or less, the generation of curl of the colored film layer can be more effectively suppressed, and the productivity of the conductive laminate can be further increased. In addition, the conductive laminate of the present invention can achieve thinning in addition to improving alcohol resistance, surface insulation, and productivity. When the colored layer is a multilayer body, the thickness of the colored layer means the total thickness of the multilayer body.

[0092] The pencil hardness of the colored layer is preferably HB to 2H, and more preferably F to H. By setting it to HB or more, suitable alcohol resistance can be realized, and by setting it to 2H or less, the degree of curl of the colored film layer can be suppressed, and the productivity of the conductive laminate can be increased. In addition, the adhesion between the colored layer and the resin film layer can be enhanced, and the interlayer adhesion of the entire conductive laminate can be made better. The hardness of the colored layer can be measured based on the scratching hardness (pencil method) of JIS K5600.

[0093] When the colored layer is a multilayer body, the composition and the like of each layer constituting the multilayer body may be the same or different as long as each layer can exhibit the above-described predetermined glass transition temperature. The cured resin contained in each layer preferably exhibits the above-described predetermined glass transition temperature.

[0094] (3) Optional configuration In addition to the coloring layer and the resin film layer described above, the colored film layer can include a matte layer in its structure. The matte layer is usually disposed on the surface of the coloring layer disposed on the surface (the first surface of the resin film layer) opposite to the conductive layer of the resin film layer. In other words, when the colored film layer includes a matte layer in its structure, the colored film layer can have a structure in which the matte layer, the coloring layer, and the resin film layer are laminated in at least this order, and the matte layer is located on the outermost surface of the colored film side surface of the conductive laminate. When the matte layer is disposed on the coloring layer, the matte layer is disposed in direct contact with the surface of the coloring layer without intervening other layers.

[0095] By further providing a matte layer on the coloring layer provided on the surface of the colored film layer opposite to the conductive layer side of the resin film layer, in addition to improving the alcohol resistance and surface insulation of the surface of the colored film layer side, the lightness L of the colored film layer * , chromaticity a * , and chromaticity b * , and each physical property of the 60° gloss value can be adjusted, and the design property and concealment property of the entire conductive laminate can be enhanced. In particular, it is preferable to provide a matte layer for adjusting the 60° gloss value.

[0096] In the present invention, the matte layer exhibits a glass transition temperature within a predetermined range. The glass transition temperature of the matte layer may be within the range of 43°C to 70°C, preferably 45 to 68°C, and more preferably 50°C to 65°C, which is the same as the range of the glass transition temperature of the coloring layer described above. Thereby, the alcohol resistance of the matte layer can be enhanced. The glass transition temperature is a value measured using DSC in accordance with ISO 3146.

[0097] The matting layer is a layer containing a resin binder and fine particles. Examples of the fine particles include general-purpose fine particles such as silica, calcium carbonate, and barium sulfate. Also, since the glass transition temperature of the matting layer is mainly due to the glass transition temperature of the resin binder, as the resin binder, a resin within the above-mentioned predetermined range of glass transition temperature can be appropriately selected from the resins commonly used in the matting layer and used. Among them, the matting layer is preferably one in which silica particles are dispersed in a urethane-based resin.

[0098] The thickness of the matting layer is not particularly limited as long as it can exhibit the desired function, and is preferably 0.3 μm or more, 0.4 μm or more, 0.5 μm or more. Also, the thickness of the matting layer may be such that it does not significantly affect the total thickness of the conductive laminate, and is preferably 3 μm or less, 2 μm or less, 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 particularly preferably 0.5 μm or more and 1.5 μm or less.

[0099] The matting layer can be formed by coating a known surface treatment agent containing a matting agent (i.e., a matting agent) in which fine particles are dispersed in a resin binder on the surface opposite to the resin film layer side of the colored layer.

[0100] (3) Others The colored film layer in the present invention is configured by appropriately combining the above-mentioned resin film layer and the above-mentioned colored layer. The combination is not limited, but among them, a combination in which the resin film layer is a polyester film and the colored layer is a layer containing a cured product of a resin composition containing a polyol component mainly composed of polyester polyol and an isocyanate component mainly composed of polyfunctional isocyanate is more preferable in that the adhesion between the resin film layer and the colored layer is further enhanced, and the interlayer adhesion within the colored film layer and the interlayer adhesion of the entire conductive laminate can be improved.

[0101] The surface resistivity of the colored film layer in the present invention is preferably 1×10 9 Ω / □ or more, and 1×1010 It is more preferably Ω / □ or more, and 1×10 11 It is even more preferably Ω / □ or more. By having 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 side of the colored film layer. Note that, although a larger surface resistivity of the colored film layer is better, generally it can be 1×10 18 Ω / □ or less, 1×10 16 Ω / □ or less, 1×10 14 Ω / □ or more, 1×10 12 Ω / □ or less.

[0102] The surface resistivity of the colored film layer refers to the value measured in accordance with JIS-K6911, and can be measured by applying a voltage of 500V to the colored film layer using a resistivity meter (Digital Ultra High Resistance / Micro Ammeter R8340, TR42 Box manufactured by Advantest).

[0103] In the present invention, from the viewpoints of ensuring designability, concealment, and light-shielding properties, the total light transmittance of the colored film 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 in accordance with JIS K7105.

[0104] (4) Method for manufacturing the colored film layer The colored film layer is obtained by dissolving and dispersing a resin composition containing the above-described coloring material, and a main agent and a curing agent which are precursors of a resin cured product in an organic solvent to obtain a colored ink, printing the colored ink on the surface of the resin film layer by a desired printing method, and drying to form a colored layer. Examples of the printing method of the colored ink include known printing methods such as direct gravure printing, reverse gravure printing, and small-diameter gravure printing. Among them, direct gravure printing, which is less likely to tear even for a thin resin film layer and has excellent printing suitability, is preferred.

[0105] The organic solvent used in the coloring ink for forming the coloring layer is not particularly limited, but it is preferably contained an organic solvent without a hydroxyl group for the purpose of dispersing the coloring material in the polyester polyol and for dilution. As the organic solvent without a hydroxyl group, any known one can be used. For example, esters such as ethyl acetate, butyl acetate, and cellosolve acetate, 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 methylene chloride and ethylene chloride, dimethyl sulfoxide, dimethyl sulfonamide, and the like can be mentioned. Preferably, they are ethyl acetate and methyl ethyl ketone.

[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 still more preferably 15 μm or more. Also, the above total thickness is preferably less than 45 μm, more preferably less than 38 μm, and still 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 still more preferably 15 μm or more and less than 25 μm. By setting the total thickness of the conductive laminate within the above range, it is possible to exhibit good alcohol resistance and surface insulation properties on the surface of the colored film layer side while having a small and thin total thickness, and further to obtain a conductive laminate excellent in productivity. Also, while being thin, it is possible to achieve the compatibility of various properties such as conductivity, electromagnetic wave shielding property, interlayer adhesion, and design property and concealment property.

[0107] The conductive laminate of the present invention has the above-described layer structure, and the lightness L * a * b * defined in the CIE L * , chromaticity a * , and chromaticity b *It is preferable that each of them has a predetermined value. The color tone of the conductive layer is suppressed, and the conductive laminate can present a black color with excellent color density and hue and high texture on the surface of the colored film layer side. As a result, the conductive laminate of the present invention can exhibit excellent surface design and hiding power while being thin, in addition to the effects of alcohol resistance, surface insulation, and productivity.

[0108] In more detail, the conductive laminate of the present invention has a CIE L * a * b * Lightness L defined in the color system * is preferably 20 or more, more preferably 21 or more, more preferably 21.5 or more, more preferably 22 or more, and even more preferably 22.5 or more. * is preferably 27 or less, more preferably 25 or less, even more preferably 24 or less, and even more preferably 23 or less. More specifically, the lightness L * The lightness L measured from the surface of the colored film layer side of the conductive laminate of the present invention is preferably from 20 to 27, more preferably from 21 to 25, still more preferably from 21.5 to 24, and still more preferably from 22 to 23. * When the color layer is in the above range, the conductive laminate can exhibit excellent jet black design, and when used in combination with other colored parts in an electric / electronic device, it can create a sense of unity with the colors of the other parts. In particular, when at least the colored layer is black, it can create a sense of unity with other black parts in an electric / electronic device, and the black design is further improved.

[0109] The conductive laminate of the present invention has a CIE L * a * b * Chromaticity a specified in the color system * is preferably -2 or more, more preferably -1.5 or more, still more preferably -1 or more, still more preferably -0.5 or more, and still more preferably 0 or more. *is preferably 2 or less, more preferably 1.5 or less, still more preferably 1 or less, and most preferably 0.5 or less. More specifically, the chromaticity a * is preferably -2 or more and 2 or less, more preferably -1 or more and 1 or less, and even more preferably -0.5 or more and 0.5 or less. The conductive laminate of the present invention has a chromaticity a measured from the surface on the colored film layer side * within the above range, can exhibit excellent coloring design properties as a conductive laminate, and can achieve a sense of unity with the colors presented by other colored components when used in combination with other colored components in an electric or electronic device. In particular, when at least the colored layer is black, it can achieve a sense of unity with other black components in an electric or electronic device.

[0110] The conductive laminate of the present invention has a chromaticity b defined in the CIE L * a * b * color system on the surface of the colored film layer side * is preferably -2 or more, preferably -1.5 or more, and -1 or more. Also, the chromaticity b * is preferably 2 or less, preferably 1.5 or less, 1 or less, 0.5 or less, and 0 or less. More specifically, the chromaticity b * is preferably -2 or more and 2 or less, more preferably -2 or more and 0 or less, still more preferably -1.5 or more and 0.5 or less, -1.5 or more and 0 or less, and -1 or more and 0 or less. The conductive laminate of the present invention has a chromaticity b measured from the surface on the colored film layer side * within the above range, can exhibit excellent coloring design properties as a conductive laminate, and can achieve a sense of unity with the colors presented by other colored components when used in combination with other colored components in an electric or electronic device. In particular, when at least the colored layer is black, it can achieve a sense of unity with other black components in an electric or electronic device.

[0111] The conductive laminate of the present invention has a lightness L defined in the CIE L * a * b * color system on the surface of the colored film layer side* is 20 or more and 27 or less, and chromaticity a * is -2 or more and 2 or less, and chromaticity b * is preferably -2 or more and 2 or less. Among them, lightness L * is 21 or more and 25 or less, and chromaticity a * is -1 or more and 1 or less, and chromaticity b * is preferably -1.5 or more and 0.5 or less, and lightness L * is 21.5 or more and 24 or less, and chromaticity a * is -0.5 or more and 0.5 or less, and chromaticity b * is more preferably -1 or more and 0 or less.

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

[0113] In addition, for the conductive laminate of the present invention, the 60° gloss value of the surface on the colored film layer side is preferably 1 or more and 5 or less, preferably 1 or more and 4 or less, and more preferably 1 or more and 3 or less. When the 60°C gloss value measured from the surface on the colored film layer side of the conductive laminate of the present invention is within the above range, the glossiness can be suppressed, and the conductive laminate can exhibit excellent matte design as a conductive laminate. When used in combination with other colored components in electrical and electronic devices, the visibility of the conductive laminate due to the glossiness can be suppressed, and a sense of unity can be achieved with the colors presented by other components. In particular, when at least the colored layer is black, excellent matte black design can be exhibited, and a sense of unity can be achieved with other black components in electrical and electronic devices.

[0114] The 60° gloss value is the glossiness measured at a set angle of 60° in accordance with JIS Z 8741 with respect to the surface on the colored film layer side of the conductive laminate. The measurement can be performed using a commercially available measuring device (for example, BYK Cat No.4563 Micro-TRI-Glossmeter).

[0115] By having the above-described layer configuration, the conductive laminate of the present invention can be thin while showing high insulation on the surface on the colored film layer side, and high conductivity on the surface on the conductive layer side.

[0116] The conductive laminate of the present invention preferably has a surface resistivity of 1×10 8 Ω / sq or more on the surface on the colored film layer side, more preferably 1×10 9 Ω / sq or more, still more preferably 1×10 10 Ω / sq or more, and even more preferably 1×10 11 Ω / sq or more. By having the surface resistivity of the surface on the colored film layer side of the conductive laminate within the above range, it becomes possible to exhibit higher insulation on the surface on the colored film layer side. Note that, although a larger surface resistivity of the surface on the colored film layer side of the conductive laminate is more preferable, generally, it can be 1×10 18 Ω / sq or less, 1×10 16 Ω / sq or less, 1×10 14 Ω / sq or less, and 1×10 12 Ω / sq or less.

[0117] Also, the conductive laminate of the present invention preferably has a surface resistivity of 10 mΩ / sq or less on the surface on the conductive layer side, more preferably 1 mΩ / sq or less, and even more preferably 0.6 mΩ / sq or less. By having the surface resistivity of the surface on the conductive layer side of the conductive laminate within the above range, it becomes possible to exhibit higher conductivity on the surface on the conductive layer side. Note that, although a smaller surface resistivity of the surface on the conductive layer side of the conductive laminate is more preferable, generally, it can be 0.001 mΩ / sq or more.

[0118] The surface resistivity of the colored film layer side surface and the conductive layer side surface of the conductive laminate refers to the values measured in accordance with JIS-K6911, and can be measured by applying a four-terminal probe to the colored film layer side surface or the conductive layer side surface of the conductive laminate using a resistivity meter (MCP-T600, manufactured by Mitsubishi Chemical Corporation).

[0119] 5. Method for manufacturing a conductive laminate The method for manufacturing the conductive laminate of the present invention is not particularly limited. Among them, a colored ink film layer having a colored layer and a resin film layer is formed by applying a colored ink having a glass transition temperature after curing within a predetermined range on at least one surface of the resin film layer. A colored film layer forming step, an adhesive layer or an adhesive layer forming step of forming an adhesive layer or an adhesive layer by applying an adhesive or an adhesive on the surface of the colored film layer on the resin film layer side, and a conductive layer forming step of laminating a metal foil as a conductive layer on the adhesive layer or the adhesive layer. The manufacturing method has excellent productivity because it can manufacture a conductive laminate while suppressing the occurrence of curl and wrinkles, and is preferable because it can have a laminated structure in which delamination is less likely to occur.

[0120] In the colored film layer forming step, the method of applying the colored ink to the resin film layer is not particularly limited as long as the thickness of the colored layer after drying is a desired size, and for example, a gravure coating method or the like can be used.

[0121] Further, in the adhesive layer or adhesive layer forming step, the method of applying the adhesive or adhesive is not particularly limited as long as the thickness of the adhesive layer or adhesive layer after drying is a desired size, and for example, known methods such as a microgravure coating method, a die coating method, and a lip coating method can be used.

[0122] 6. Applications of the conductive laminate The conductive laminate of the present invention can be widely applied to applications that require high alcohol resistance and insulation on the surface by providing an adhesive layer on the surface of the conductive layer side of the conductive laminate alone or as described below. Among others, it can be suitably used for protecting circuit components of portable electronic devices that require miniaturization, thinning, and high alcohol resistance, and for electromagnetic wave shielding or grounding inside and outside electrical or electronic devices such as thin mobile devices.

[0123] II. Conductive Adhesive Tape The conductive adhesive tape of the present invention has the conductive laminate described in the section of "I. Conductive Laminate" above and a conductive adhesive layer provided on the surface on the conductive layer side of the conductive laminate. FIG. 2 is a schematic cross-sectional view showing an example of the conductive adhesive tape of the present invention. In the conductive adhesive tape 20, a conductive adhesive layer 11 is provided on the surface on the conductive layer 1 side of the conductive laminate 10.

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

[0125] In addition to the above-mentioned functions, the conductive adhesive tape of the present invention can achieve thinning with a small total thickness, and can further achieve the compatibility of various characteristics such as conductivity, electromagnetic wave shielding property, interlayer adhesion property, design property, and shielding property.

[0126] 1. Conductive Laminate Regarding the conductive laminate in the present invention, since it is the same as the details described in the section of "I. Conductive Laminate" above, the description here is omitted.

[0127] 2. Conductive Adhesive Layer The conductive adhesive layer in the present invention contains an adhesive component and a conductive filler.

[0128] As the conductive filler, nickel powder, copper powder, silver powder, gold powder, conductive carbon black, metal-plated glass, resin powder, etc. can be used. Among them, nickel powder is more preferable because it is excellent in conductivity with respect to the metal foil which is the conductive layer in the conductive laminate, particularly in conductivity with respect to copper foil and stainless steel foil.

[0129] The content of the conductive filler in the conductive adhesive layer can be an amount capable of exhibiting a desired conductivity and is not particularly limited, but it is preferably in the range of 0.1% by mass to 80% by mass, more preferably in the range of 0.5% by mass to 40% by mass, and most preferably in the range of 0.8% by mass to 10% by mass in the total amount (100% by mass) of the conductive adhesive layer. This is because when the content of the conductive filler is within the above range, it is easy to achieve both conductivity and adhesiveness even in a thin film.

[0130] The adhesive component constituting the conductive adhesive layer is not particularly limited, and for example, it 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, fluorine adhesives, creep property-improved adhesives, radiation-curable adhesives, etc. The adhesive components can be used alone or in combination of two or more.

[0131] Among them, as the adhesive component, acrylic adhesives can be preferably used particularly because of their high adhesion reliability. Acrylic adhesives use (meth)acrylic polymers as the adhesive component or main agent, and appropriately contain additives such as crosslinking agents, tackifiers, softeners, plasticizers, fillers, anti-aging agents, colorants, etc. as necessary. The (meth)acrylic polymer is a polymer having (meth)acrylic acid alkyl esters as the main monomer component, and is prepared by using monomers (copolymerizable monomers) capable of copolymerizing with the (meth)alkyl esters as necessary.

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

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

[0134] Also, it is preferable that the acrylic copolymer is copolymerized with a highly polar vinyl monomer. Examples of the highly polar vinyl monomer include vinyl monomers having a carboxyl group, vinyl monomers having a hydroxyl group, vinyl monomers having an amide group, etc. One or more of these are used. Among them, carboxyl group-containing monomers can be preferably used because they can easily adjust the adhesiveness of the adhesive to a suitable range.

[0135] As the vinyl monomer having 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 them, it is preferable to use acrylic acid as a copolymerization component.

[0136] When using a vinyl monomer having a carboxyl group, its content is preferably 0.2% by mass to 15% by mass, more preferably 0.4% by mass to 10% by mass, and still more preferably 0.5% by mass to 6% by mass in the monomer components constituting the acrylic copolymer. By containing within this range, it is easy to adjust the adhesiveness of the adhesive to a suitable range.

[0137] Examples of the monomer having a hydroxyl group include hydroxyl group-containing (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and the like.

[0138] Examples of the monomer having an amide group include N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, acrylamide, N,N-dimethylacrylamide, and the like.

[0139] Examples of other highly polar vinyl monomers include vinyl acetate, ethylene oxide-modified succinic acid acrylate, sulfonic acid group-containing monomers such as 2-acrylamido-2-methylpropanesulfonic acid, and terminal alkoxy-modified (meth)acrylates such as 2-methoxyethyl (meth)acrylate and 2-phenoxyethyl (meth)acrylate.

[0140] The content of the highly polar vinyl monomer is preferably such that the total amount is 0.2% by mass to 15% by mass, more preferably 0.4% by mass to 10% by mass, and still more preferably 0.5% by mass to 6% by mass in the monomer components constituting the acrylic copolymer. By containing within this range, it is easy to adjust the adhesiveness of the adhesive 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, 700,000 or more. Also, 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, 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 have good initial adhesiveness 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] The (meth)acrylic polymer can be prepared by a conventional polymerization method such as solution polymerization method, emulsion polymerization method, ultraviolet irradiation polymerization method, etc.

[0143] In order to improve the adhesive strength, an adhesion - imparting resin may be added to the conductive adhesive layer. Examples of the adhesion - imparting resin include rosin - based resins such as rosin and ester compounds of rosin; terpene - based resins such as diterpene polymers and α - pinene - phenol copolymers; petroleum resins such as aliphatic (C5 - based) and aromatic (C9); styrene - based resins; phenolic resins; xylene resins; methacrylic resins, etc. Among them, in order to be thin - type and improve the adhesive strength, it is preferable to contain a rosin - based resin, and more preferably to contain a polymerized rosin - based resin. Also, in addition to the rosin - based resin, a styrene - based resin may be mixed and contained.

[0144] Also, in order to increase the initial adhesive force, it is preferable to mix and use an adhesion - imparting resin that is liquid at room temperature. Examples of the adhesion - imparting resin that is liquid at room temperature include the liquid resins of the above - mentioned adhesion - imparting resins, and low - molecular - weight liquid rubbers such as process oil, polyester - based plasticizers, polybutene, etc. Particularly, terpene phenol resin is preferable. Commercially available products include YP - 90L manufactured by Yasuhara Chemical Co., Ltd.

[0145] As the addition amount of the tackifier resin, a range of 10 to 70 parts by mass is preferable with respect to 100 parts by mass of the acrylic copolymer. More preferably, it is within the range of 20 to 60 parts by mass. By adding the tackifier resin within the above range, the adhesive strength can be improved.

[0146] The gel fraction of the conductive adhesive layer is not particularly limited, but it is preferably 10 to 60% by mass because sufficient adhesiveness is likely to be exhibited even for thin and thick layers, 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 obtained by immersing the cured conductive adhesive layer in toluene, leaving it for 24 hours, measuring the mass of the insoluble matter remaining after drying, and expressing it as a percentage with respect to the original mass. Gel fraction (% by mass) = [(mass of the conductive adhesive layer after toluene immersion) / (mass of the conductive adhesive layer before toluene immersion)] × 100

[0148] The storage modulus of the conductive adhesive layer at 25°C is preferably 1 × 10 4 or more and 5 × 10 5 Pa or less, and more preferably 2 × 10 4 or more and 1 × 10 5 Pa or less. This is because when the storage modulus of the conductive adhesive layer at 25°C is within the above range, it is easy to achieve both high adhesiveness and processability even for a thin-film conductive adhesive layer. The storage modulus of the conductive adhesive layer at 25°C is a value measured by the same method and conditions as the measurement method of the storage modulus of the above-mentioned adhesive layer at 25°C.

[0149] The above conductive adhesive layer may have a single-layer structure or a multilayer structure in which conductive adhesive layers are provided on both sides of the conductive substrate. Examples of the conductive substrate in the case where the conductive adhesive layer has a multilayer structure include a metal foil substrate and a substrate obtained by plating a wet polyester nonwoven fabric substrate. Examples of the material of the metal foil include gold, silver, copper, aluminum, nickel, iron, tin, and alloys thereof. Examples of the substrate obtained by plating the wet polyester nonwoven fabric substrate include those using electroless metal plating as the plating. Examples of the metal to be plated include copper, nickel, silver, platinum, and aluminum, and among them, copper or nickel is preferable from the viewpoints of conductivity and cost. The thickness of the above conductive substrate is not particularly limited, but can be, for example, 1 μm or more and 50 μm or less.

[0150] The thickness of the conductive adhesive layer can be set to a size that can exhibit conductivity and adhesiveness, 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 conductivity can be further enhanced while reducing the total thickness of the conductive adhesive tape of the present invention.

[0151] Further, when the conductive adhesive layer has a multilayer structure, the thickness of the entire 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 provided over the entire surface on the conductive layer side of the conductive laminate, or may be provided in a pattern on the surface on the conductive layer side of the conductive laminate. When the conductive adhesive layer is provided in a pattern, in the region where the conductive adhesive layer is not disposed on the surface on the conductive layer side of the conductive laminate, the surface of the conductive layer may be exposed, or an insulating adhesive layer may be disposed in the above region, and the conductive adhesive layer and the insulating adhesive layer may be alternately disposed in a pattern. The mode in which the conductive adhesive layer and the insulating adhesive layer are alternately disposed in a pattern is preferable because the adhesiveness can be improved.

[0153] When a conductive adhesive layer and an insulating adhesive layer are alternately arranged in a pattern on the surface of the conductive layer side of the 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. Optional Configuration The conductive adhesive tape of the present invention at least includes the above-described conductive laminate and conductive adhesive layer in its configuration, but may also include other configurations. For example, a release layer may be further provided on the surface of the conductive adhesive layer opposite to the conductive laminate. This is because the conductive adhesive tape can be protected by providing the release layer.

[0155] As the release layer, a known release layer may be appropriately selected and used. A resin film subjected to a release treatment is excellent in smoothness and is preferable. Among them, a polyester film is preferable from the viewpoint of excellent heat resistance.

[0156] The release layer preferably has a surface that has been subjected to a release treatment in order to impart easy peelability. Specifically, the surface of the release layer preferably has a release treatment layer provided thereon. The release treatment layer can be formed by a general-purpose release treatment agent used for the release layer of a double-sided adhesive tape. Examples of such a release treatment agent include silicone-based, fluorine-based, and long-chain alkyl-based release treatment agents. The release treatment layer may be formed by lamination or coating.

[0157] The peel force of the release layer may be appropriately adjusted according to the usage mode and the like, but the peel force with respect to the conductive adhesive tape can be 0.01 N / 20 mm to 2 N / 20 mm, preferably 0.05 N / 20 mm to 0.15 N / 20 mm. This is because when the release layer is peeled off, it becomes easier to suppress the deformation of the conductive adhesive tape. The peel force can be measured by backing a 50-μm-thick PET film as a release layer on the exposed surface of the conductive adhesive layer of the conductive adhesive tape and peeling it in the 180° direction at a speed of 0.3 m / min to 10 m / 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 still 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, it is possible to exhibit good alcohol resistance and surface insulation while being thin and having a small total thickness. In addition, functions such as conductivity, electromagnetic shielding property, interlayer adhesion, design property, and concealment property can also be exhibited well. And such a conductive adhesive tape can be obtained with high productivity. Note 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 has a lightness L * a * b * in the CIE L * color system, measured from the surface of the conductive laminate side, * chromaticity a * and chromaticity b * a * b * in the CIE L * color system, measured from the surface of the colored film layer side of the conductive laminate, * chromaticity a * and chromaticity b * a * b * in the CIE L * color system, measured from the surface of the conductive laminate side, * chromaticity a * and chromaticity b

[0160] In addition, for the conductive adhesive tape of the present invention, it is preferable that the 60° gloss value measured from the surface on the side of the conductive laminate is within the range of the 60° gloss value measured from the surface on the side of the colored film layer of the conductive laminate described in the section of "I. Conductive laminate".

[0161] The CIE color values (L * , a * , b * ) and the 60° gloss value of the surface on the side of the conductive laminate of the conductive adhesive tape of the present invention are respectively the CIE color values (L * , a * , b * ) of the surface on the side of the colored film layer of the conductive laminate described in the section of "I. Conductive laminate" and the values measured by the same method and conditions as the measurement method of the 60° gloss value.

[0162] For the conductive adhesive tape of the present invention, it is preferable that the surface resistivity measured from the surface on the side of the conductive laminate is within the range of the surface resistivity measured from the surface on the side of the colored film layer of the conductive laminate described in the section of "I. Conductive laminate".

[0163] In addition, for the conductive adhesive tape of the present invention, it is preferable that the surface resistivity measured from the surface on the side of the conductive adhesive is 10 mΩ / sq or less, more preferably 1 mΩ / sq or less, and even more preferably 0.6 mΩ / sq or less. Note that the smaller the surface resistivity measured from the surface on the side of the conductive adhesive of the conductive adhesive tape, the more preferable it is, but generally it can be 0.001 mΩ / sq or more.

[0164] Note that the surface resistivities of the surface on the side of the conductive laminate and the surface on the side of the conductive adhesive layer of the conductive adhesive tape respectively refer to the values measured in accordance with JIS-K6911, and can be measured by applying a four-terminal probe to the surface on the side of the conductive laminate or the surface on the side of the conductive adhesive layer of the conductive adhesive tape using a resistivity meter (MCP-T600, manufactured by Mitsubishi Chemical Corporation).

[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, it can be manufactured using a manufacturing method having a step of preparing the conductive laminate described in the section of "I. Conductive laminate" above, a step of preparing a conductive adhesive containing a conductive filler and an adhesive component, and a step of forming a conductive adhesive layer by applying the conductive adhesive on the surface of the conductive layer side of the conductive laminate so that the thickness after drying becomes a desired size.

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

[0167] This disclosure is not limited to the above embodiments. The above embodiments are examples, and any configuration that has substantially the same configuration as the technical idea described in the claims of this disclosure and exhibits the same operational effects is included in the technical scope of this disclosure.

Examples

[0168] Examples of this invention are described below for more specific explanation. In the production of the adhesive, "parts" indicating the blending amount of materials represents "parts by mass".

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

[0170] (Production of Adhesive B) 97.98 parts of n-butyl acrylate, 2 parts of acrylic acid, and 0.02 part of 4-hydroxybutyl acrylate were subjected to solution polymerization in an ethyl acetate solution at 80 °C for 8 hours using 0.2 part of azobisisobutyronitrile as a polymerization initiator to obtain an acrylic polymer having a mass average molecular weight of 900,000. To 100 parts of the acrylic polymer, 5 parts of a polymerized rosin ester (trade name "D-135", manufactured by Arakawa Chemical Industries, Ltd.), 20 parts of a disproportionated rosin ester (trade name "KE-100", manufactured by Arakawa Chemical Industries, Ltd.), and 25 parts of a petroleum resin (trade name "FTR6100") were added, and ethyl acetate was added to adjust an adhesive solution having a solid content of 40%. Next, 10 parts of a black colorant "DICTON CRO AR8555" (carbon black content: 45% (solid content ratio), resin solid content concentration 49%) manufactured by DIC was added to the above adhesive solution, and the mixture was uniformly mixed with a stirrer. Further, 1.2 parts of an isocyanate-based crosslinking agent (trade name "NC40", manufactured by DIC Corporation) was added, and the mixture was stirred and mixed uniformly to prepare Adhesive B. The gel fraction of Adhesive B was 20%, and the storage elastic modulus at 25 °C was 8×10 4 Pa.

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

[0172] Next, to 100 parts by mass of the solid content of the acrylic polymer B, 10 parts by mass of a polymerized rosin pentaerythritol ester ("Pensel D-135" manufactured by Arakawa Chemical Industries, Ltd., softening point 135 °C) and 10 parts by mass of a disproportionated rosin glycerin ester ("Super Ester A-100" manufactured by Arakawa Chemical Industries, Ltd., softening point 100 °C) were blended, and using ethyl acetate, the solid content concentration of the acrylic polymer was adjusted to 40% by mass to obtain an acrylic adhesive solution B.

[0173] 100 parts by mass of the acrylic adhesive solution B (solid content concentration 40% by mass), 0.4 part by mass of nickel powder ("NI255T" bead-shaped conductive particles manufactured by Fukuda Metal Foil & Powder Co., Ltd., d50: 26.0 μm), 2 parts by mass of an isocyanate-based crosslinking agent ("Barnock NC40" manufactured by DIC Corporation, solid content 40% by mass) as a crosslinking agent, and 70 parts by mass of ethyl acetate as a diluting solvent were mixed using a dispersion stirrer for 10 minutes to prepare a conductive adhesive A.

[0174] (Production of polyester polyol resin A) 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 to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, and reacted at 80 °C for 10 hours with stirring to obtain a polyester polyol resin A having a resin solid content of 50% and a weight average molecular weight of 40,000.

[0175] (Production of polyester polyol resin B) In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas 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, and the mixture was reacted at 80 °C for 10 hours with stirring to obtain a polyester polyol resin B having a resin solid content of 50% and a mass average molecular weight of 40,000.

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

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

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

[0179] (Production of polyester polyol resin F) 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 to a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube, and the mixture was reacted at 80 °C for 10 hours under stirring to obtain a polyester polyol resin F having a resin solid content of 50% and a mass average molecular weight of 20,000.

[0180] (Production of Black Ink A) 100 parts by mass of polyester polyol resin A (resin solid content: 50% by mass), 40 parts by mass of carbon black "Carbon Special 250P" manufactured by Degussa, 5 parts by mass of an inorganic filler (silane coupling treatment of "Silohobic 704" manufactured by Fuji Silysia Chemical Ltd., average particle diameter 3.5 μm by Coulter counter method), 23 parts by mass of methyl ethyl ketone, 13 parts by mass of toluene, 6 parts by mass of ethyl acetate, 3 parts by mass of N-propyl acetate, and 3 parts by mass of isopropyl alcohol were added, and the mixture was wet-dispersed with a sand mill for about 1 hour. Then, 2 parts of a curing agent "KR90" (biuret of hexamethylene diisocyanate, solid content: 40% by mass) manufactured by DIC and 300 parts of ethyl acetate were added to prepare Black Ink A. The carbon black content in the solid content of the black ink was 42% by mass.

[0181] (Production of Black Ink B) 100 parts by mass of polyester polyol resin B (resin solid content: 50%), 40 parts by mass of carbon black "Carbon Special 250P" manufactured by Degussa, 5 parts by mass of an inorganic filler (silane coupling treatment of "Silohobic 704" manufactured by Fuji Silysia Chemical Ltd., average particle diameter 3.5 μm by Coulter counter method), 23 parts by mass of methyl ethyl ketone, 13 parts by mass of toluene, 6 parts by mass of ethyl acetate, 3 parts by mass of N-propyl acetate, and 3 parts by mass of isopropyl alcohol were added, and the mixture was wet-dispersed with a sand mill for about 1 hour. Then, 2 parts of a curing agent "KR90" (biuret of hexamethylene diisocyanate, solid content: 40%) manufactured by DIC and 300 parts of ethyl acetate were added to prepare Black Ink B. The carbon black content in the solid content of the black ink was 42%.

[0182] (Manufacture of Black Ink C) 100 parts by mass of polyester polyol resin C (resin solid content: 50%), 40 parts by mass of carbon black "Carbon Special 250P" manufactured by Degussa, 5 parts by mass of inorganic filler (silane coupling treatment of "Silohobic 704" manufactured by Fuji Silysia Chemical Ltd., average particle diameter of 3.5 μm by Coulter counter method), 23 parts by mass of methyl ethyl ketone, 13 parts by mass of toluene, 6 parts by mass of ethyl acetate, 3 parts by mass of N-propyl acetate, and 3 parts by mass of isopropyl alcohol were added, and the mixture was wet-dispersed with a sand mill for about 1 hour. Then, 2 parts of hardener "KR90" (biuret of hexamethylene diisocyanate, solid content: 40%) manufactured by DIC and 300 parts of ethyl acetate were added to prepare Black Ink C. The carbon black content in the solid content of the black ink was 42%.

[0183] (Manufacture of Black Ink D) 100 parts by mass of polyester polyurethane resin D (resin solid content: 50%), 40 parts by mass of carbon black "Carbon Special 250P" manufactured by Degussa, 5 parts by mass of inorganic filler (silane coupling treatment of "Silohobic 704" manufactured by Fuji Silysia Chemical Ltd., average particle diameter of 3.5 μm by Coulter counter method), 23 parts by mass of methyl ethyl ketone, 13 parts by mass of toluene, 6 parts by mass of ethyl acetate, 3 parts by mass of N-propyl acetate, and 3 parts by mass of isopropyl alcohol were added, and the mixture was wet-dispersed with a sand mill for about 1 hour. Then, 2 parts of hardener "KR90" (biuret of hexamethylene diisocyanate, solid content: 40%) manufactured by DIC and 300 parts of ethyl acetate were added to prepare Black Ink D. The carbon black content in the solid content of the black ink was 42%.

[0184] (Manufacture of Black Ink E) 100 parts by mass of polyester polyol resin E (resin solid content: 50%), 40 parts by mass of carbon black "Carbon Special 250P" manufactured by Degussa, 5 parts by mass of inorganic filler (Fujisilysia Corporation's "Silohobic 704" silane coupling treatment: average particle diameter 3.5 μm by Coulter counter method), 23 parts by mass of methyl ethyl ketone, 13 parts by mass of toluene, 6 parts by mass of ethyl acetate, 3 parts by mass of N-propyl acetate, and 3 parts by mass of isopropyl alcohol were added, and the mixture was wet-dispersed with a sand mill for about 1 hour. Then, 2 parts of hardener "KR90" (biuret of hexamethylene diisocyanate, solid content: 40%) manufactured by DIC and 300 parts of ethyl acetate were added to prepare black ink F. The carbon black content in the solid content of the black ink was 42%.

[0185] (Manufacture of Black Ink F) 100 parts by mass of polyester polyol resin F (resin solid content: 50%), 40 parts by mass of carbon black "Carbon Special 250P" manufactured by Degussa, 5 parts by mass of inorganic filler (Fujisilysia Corporation's "Silohobic 704" silane coupling treatment: average particle diameter 3.5 μm by Coulter counter method), 23 parts by mass of methyl ethyl ketone, 13 parts by mass of toluene, 6 parts by mass of ethyl acetate, 3 parts by mass of N-propyl acetate, and 3 parts by mass of isopropyl alcohol were added, and the mixture was wet-dispersed with a sand mill for about 1 hour. Then, 2 parts of hardener "KR90" (biuret of hexamethylene diisocyanate, solid content: 40%) manufactured by DIC and 300 parts of ethyl acetate were added to prepare black ink G. The carbon black content in the solid content of the black ink was 42%.

[0186] 1. Manufacture of Conductive Laminate [Example 1-1] A black ink A was gravure-coated on a Toray polyester film Lumirror 2F51 (thickness: 2 μm) to form a colored layer with a dry thickness of 2 μm, and aged at 40°C for 1 day to obtain a black ink-coated film A (colored film layer A). The glass transition temperature of the colored layer of the colored film layer A, which is a cured product of the black ink A, was 51°C. The glass transition temperature of the colored layer was measured using DSC in accordance with ISO 3146. Hereinafter, the measurement of the glass transition temperature of the colored layer in other examples and comparative examples shall be the same.

[0187] Next, an adhesive B was gravure-coated on the surface of the polyester film side of the black ink-coated film A so that the dry thickness after drying was 1 μm, dried at 70°C for 2 minutes to form a black adhesive layer B, and then an electrolytic copper foil NC-WS6 μm (thickness: 6 μm) manufactured by Furukawa Electric Co., Ltd. was laminated on the surface of the adhesive layer B side as a conductive layer, and further aged at 40°C for 2 days to obtain a conductive laminate I.

[0188] [Example 1-2] A black-coated film B (colored film layer B) and a conductive laminate II were obtained in the same manner as in Example 1-1 except that a colored layer was formed using black ink B instead of black ink A. The glass transition temperature of the colored layer of the colored film B, which is a cured product of the black ink B, was 48°C.

[0189] [Example 1-3] A black ink-coated film C (colored film layer C) and a conductive laminate III were obtained in the same manner as in Example 1-1 except that a colored layer was formed using black ink C instead of black ink A. The glass transition temperature of the colored layer of the colored film C, which is a cured product of the black ink C, was 68°C.

[0190] [Example 1-4] A black ink-coated film A1 (colored film layer A1) and a conductive laminate IV were obtained in the same manner as in Example 1-1, except that Toray's polyester film Lumirror S10#12 (thickness: 12 μm) was used instead of Toray's polyester film Lumirror 2F51 (thickness: 2 μm). The glass transition temperature of the colored layer of the colored film A1, which is the cured product of black ink A, was 51°C.

[0191] [Example 1-5] A black ink-coated film A2 (colored film A2) and a conductive laminate V were obtained in the same manner as in Example 1-1, except that Toray DuPont's polyimide film Kapton 20EN (thickness: 5 μm) was used instead of Toray's polyester film Lumirror 2F51 (thickness: 2 μm). The glass transition temperature of the colored layer of the colored film A2, which is the cured product of black ink A, was 51°C.

[0192] [Example 1-6] A conductive laminate VI was obtained in the same manner as in Example 1-1, except that Furukawa Electric Co., Ltd.'s electrolytic copper foil NC-WS15 μm (thickness: 15 μm) was used instead of Furukawa Electric Co., Ltd.'s electrolytic copper foil NC-WS6 μm (thickness: 6 μm) as the conductive layer. The glass transition temperature of the colored layer of the colored film A, which is the cured product of black ink A, was 51°C.

[0193] [Example 1-7] A conductive laminate VII was obtained in the same manner as in Example 1-1, except that Furukawa Electric Co., Ltd.'s electrolytic copper foil NC-WS30 μm (thickness: 30 μm) was used instead of Furukawa Electric Co., Ltd.'s electrolytic copper foil NC-WS6 μm (thickness: 6 μm) as the conductive layer. The glass transition temperature of the colored layer of the colored film A, which is the cured product of black ink A, was 51°C.

[0194] [Comparative Example 1-1] A black ink-coated film D (colored film D) and a conductive laminate VIII were obtained in the same manner as in Example 1, except that black ink D was used instead of black ink A. The glass transition temperature of the colored layer of the colored film D, which is the cured product of black ink D, was -20°C.

[0195] [Comparative Example 1-2] A black ink-coated film E (colored film E) and a conductive laminate IX were obtained in the same manner as in Example 1, except that black ink E was used instead of black ink A. The glass transition temperature of the colored layer of the colored film E, which is a cured product of black ink E, was 72°C.

[0196] [Comparative Example 1-3] A black ink-coated film F (colored film F) and a conductive laminate X were obtained in the same manner as in Example 1, except that black ink F was used instead of black ink A. The glass transition temperature of the colored layer of the colored film F, which is a cured product of black ink F, was 41°C.

[0197] [Comparative Example 1-4] An adhesive tape with a total thickness of 10 μm (manufactured by DIC Corporation, "IL-10BMF", having a laminated structure of a black colored layer (containing urethane resin, thickness: 1.5 μm) / polyethylene terephthalate film (thickness: 4.5 μm) / transparent adhesive layer (thickness: 4 μm) (" / " indicates the lamination interface)) was laminated on the smooth surface of an electrolytic copper foil CF-T8G-DK-35 (thickness 35 μm) manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd. as a conductive layer, thereby producing a conductive laminate XI. The glass transition temperature of the black colored layer in the conductive laminate XI was -20°C.

[0198] [Comparative Example 1-5] On one side of a 5-μm-thick PET film (manufactured by Teijin DuPont Films Japan Limited, "Mylar"), a polyester resin (manufactured by Unitika Ltd., "UE3220") using an isocyanate-based curing agent (manufactured by Nippon Polyurethane Industry Co., Ltd., "Coronate L") was applied at 3 g / m 2 (in terms of dry coating amount), and a 7-μm-thick soft aluminum foil (1030N-0 material, manufactured by Nippon Foil Mfg. Co., Ltd.) was laminated as conductive layer A on the coating film. Also, on the other side of the above PET film, a 7-μm-thick soft aluminum foil (1030N-0 material, manufactured by Nippon Foil Mfg. Co., Ltd.) was laminated as conductive layer B in the same manner to prepare a base substrate.

[0199] Subsequently, insulating black ink (ink in which aniline black is dispersed in a polyester resin) was applied onto one surface of this base substrate so that the dry thickness became 3 μm and dried to form a black colored layer, thereby obtaining the conductive laminate XII. The glass transition temperature of the black colored layer of the conductive laminate XII was 75°C.

[0200] 2. Manufacture of Conductive Adhesive Tape [Example 2-1] First, the above conductive adhesive A was applied onto a release film ("PET25×J0L" manufactured by Nippa) with a roll coater so that the dry thickness became 5 μm, dried at 100°C for 1 minute, and this was bonded to the copper foil surface of the conductive laminate I, and further aged at 40°C for 2 days to obtain a conductive adhesive tape.

[0201] [Example 2-2] A conductive adhesive tape was obtained in the same manner as in Example 2-1, except that the conductive laminate II was used instead of the conductive laminate I.

[0202] [Example 2-3] A conductive adhesive tape was obtained in the same manner as in Example 2-1, except that the conductive laminate III was used instead of the conductive laminate I.

[0203] [Example 2-4] A conductive adhesive tape was obtained in the same manner as in Example 2-1, except that the conductive laminate IV was used instead of the conductive laminate I.

[0204] [Example 2-5] A conductive adhesive tape was obtained in the same manner as in Example 2-1, except that the conductive laminate V was used instead of the conductive laminate I.

[0205] [Example 2-6] A conductive adhesive tape was obtained in the same manner as in Example 2-1, except that the conductive laminate VI was used instead of the conductive laminate I.

[0206] [Example 2-7] A conductive adhesive tape was obtained in the same manner as in Example 2-1, except that the conductive laminate VII was used instead of the conductive laminate I.

[0207] [Comparative Example 2-1] A conductive pressure-sensitive adhesive tape was obtained in the same manner as in Example 2-1, except that conductive laminate VIII was used instead of conductive laminate I.

[0208] [Comparative Example 2-2] A conductive pressure-sensitive adhesive tape was obtained in the same manner as in Example 2-1, except that conductive laminate IX was used instead of conductive laminate I.

[0209] [Comparative Example 2-3] A conductive pressure-sensitive adhesive tape was obtained in the same manner as in Example 2-1, except that conductive laminate X was used instead of conductive laminate I.

[0210] [Comparative Example 2-4] A conductive pressure-sensitive adhesive tape was obtained in the same manner as in Example 2-1, except that conductive laminate XI was used instead of conductive laminate I.

[0211] [Comparative Example 2-5] A conductive pressure-sensitive adhesive tape was obtained in the same manner as in Example 2-1, except that conductive laminate XII was used instead of conductive laminate I.

[0212] [Evaluation] The performance of the conductive laminates of the examples and comparative examples, and the conductive pressure-sensitive adhesive tapes of the examples and comparative examples was evaluated by the following measurement methods.

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

[0214] (Thinness) The thicknesses of the conductive laminates of the examples and comparative examples were evaluated according to the following evaluation criteria. ◎: Less than 25 μm 〇: 25 μm or more and less than 45 μm ×: 45 μm or more

[0215] (Alcohol resistance) The same location on the surface of the colored film layer side of the conductive laminate (the surface of the black colored layer in Comparative Examples 1-4 and 1-5) was rubbed 50 times using a cotton swab soaked with ethanol, and the number of rubs when color fading of the colored layer and coloring of the cotton swab occurred were evaluated. ◎: The number of times is 50 or more. 〇: The number of times is 25 or more and less than 50. ×: The number of times is 24 or less.

[0216] (Productivity) The large-sized conductive laminates of Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-4 were produced by the following method. First, a large-sized black ink-coated film (large-sized colored film layer) with a width of 1040 mm and a length of 1000 m was produced by the same method as the method for producing the colored 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 on the surface of the resin film layer side of the large-sized black ink-coated film (large-sized colored film layer) at a speed of 20 m / min using a gravure coater and dried at 70 °C for 30 seconds to form an adhesive layer with a width of 1030 mm, a length of 1000 m, and a thickness of 1 μm after drying.

[0217] Subsequently, a large-sized conductive laminate was produced by laminating a metal foil with a width of 1040 mm and a length of 1000 m on the adhesive layer formed on the surface of the resin film layer side of the large-sized black ink-coated film. For Comparative Example 1-4, an adhesive tape (「IL-10BMF」 manufactured by DIC Corporation) with a width of 1040 mm, a length of 1000 m, and a total thickness of 10 μm was used, and a metal foil with a width of 1040 mm and a length of 1000 m was laminated on the surface of the transparent adhesive layer side of the large-sized adhesive tape to produce a large-sized conductive laminate.

[0218] When producing the large-sized conductive laminate by the above method, the productivity was evaluated according to the following criteria. The pass line of the gravure coater was 50 m. The yield was evaluated by using the effective area of the obtained large-sized conductive laminate (width 1000 mm × length 1000 m = 1000 m 2 ) as the denominator and how many m 2 of good products (without wrinkles) could be produced. ◎: Can be produced without problems, with a yield of 90% or more (900 m of good products 2 or more). 〇: Some wrinkles are mixed in, but the yield is 80% or more and less than 90%. ×: Wrinkles occur when laminating with the metal foil, and the yield is less than 80%.

[0219] (Adhesion) A cellophane tape manufactured by Nichiban Co., Ltd. was attached to the surface of the colored film layer side of the conductive laminate (the surface of the black colored layer side in Comparative Examples 1-4 and Comparative Examples 1-5), rubbed 5 or 6 times with the belly of the thumb for pressure bonding, left for about 1 minute after pressure bonding, and then one end of the cellophane tape on the front and back was vigorously peeled off in the 180° direction (peeling speed: about 50 m / min). The state of the conductive laminate after peeling was evaluated. 〇: The colored layer has not peeled off or the resin film layer has been torn to pieces ×: The colored layer peels off from the resin film layer.

[0220] (L * , a * , b * ) Using a spectrophotometer (SPECTROPHOTOMETER CM-5 manufactured by KONICA MINOLTA), according to the measurement standard JIS Z 8722 with a C spectrum of 2°, the CIE color values (L * , a * , b * ) were measured respectively from 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 Comparative Examples 1-5).

[0221] (Design) L * = 20 - 25, a * = -1 - 1, b * = -2 - 0 was evaluated. ◎: All of L * , a * , b * are within the above ranges. 〇: L * , a * , b* Two of them fall within the above range. ×: L * , a * , b * Two or more of them are outside the above range.

[0222] (Insulating) Using a resistivity meter (Mitsubishi Chemical Corporation's Loresta MCP-T600), a four-terminal probe was applied to the surface on the colored film layer side of the conductive laminate of the examples and comparative examples (on the surface of the black colored layer side in Comparative Examples 1-4 and 1-5), and the surface resistivity of the surface on the colored film layer side was measured. Evaluation was carried out according to the following evaluation criteria. 〇: Surface resistivity of 9.9×10 7 Ω / □ or more (overload) ×: Surface resistivity less than 9.9×10 7 Ω / □

[0223] (Conductive) Using a resistivity meter (Mitsubishi Chemical Corporation's Loresta MCP-T600), a four-terminal probe was applied to the surface on the conductive layer side of the conductive laminates of Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-5, and the surface resistivity of the surface on the conductive layer side of the conductive laminate was measured. Evaluation was carried out according to the following evaluation criteria. ◎: 0.6 mΩ / □ or less 〇: Exceeding 0.6 mΩ / □ and 10 mΩ / □ or less ×: Exceeding 10 mΩ / □

[0224] (Adhesive force of conductive adhesive tape) The samples of Examples 2-1 to 2-7 and Comparative Examples 2-2 to 2-5 were cut into 25 mm width × 100 mm length, pasted on a SUS plate, pressed once back and forth with a 2 kg roller, left at 23°C and 50% RH for 1 hour, and the adhesive force when peeled off at a speed of 300 mm / min in the 180° direction was measured.

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

[0226]

Table 1

[0227]

Table 2

[0228]

Table 3

[0229]

Table 4

[0230] From the above Tables 1 to 4, the conductive laminates I to VII of the examples had good ethanol resistance and surface insulation properties, and furthermore had good productivity when manufactured in large sizes. On the other hand, among the conductive laminates VIII to XII of the comparative examples, at least one of ethanol resistance, surface insulation property, and productivity was poor, and it was not possible to achieve compatibility. Compared with the conductive laminate XI, the conductive laminates I to VII had a smaller total thickness, but since the CIE color values were within the desired ranges respectively, they had high designability and concealability due to black color. The conductive laminates I to VII had a laminated structure in which the colored layer in the colored film layer, the resin film layer in the colored film layer, the adhesive layer, and the metal foil were laminated in this order. Compared with the conductive laminate XII in which the colored layer was provided directly on the metal foil, the surface insulation property was good.

Explanation of Reference Signs

[0231] 1... Conductive layer (metal foil), 2... Adhesive layer or adhesive agent layer, 3... Colored film layer, 4... Resin film layer, 5... Colored layer, 10... Conductive laminate, 11... Conductive adhesive layer, 20... Conductive adhesive tape

Claims

1. a conductive layer, a pressure-sensitive adhesive or adhesive layer provided on one side of the conductive layer, and a colored film layer provided on a side of the pressure-sensitive adhesive or adhesive layer opposite to the conductive layer; the conductive layer is a metal foil; the colored film layer includes a resin film layer and a colored layer in contact with at least a surface of the resin film layer opposite to the conductive layer, The colored layer comprises a cured resin and 10 to 70% by mass of a coloring material, and the colored layer has a glass transition temperature within a range of 43°C to 70°C.

2. The CIE L ＊ a ＊ b ＊ Lightness L defined by the color system ＊ is 20 or more and 27 or less, and the chromaticity a ＊ is between -2 and 2, and the chromaticity b ＊ 2. The conductive laminate according to claim 1, wherein the value of the linearity of the conductive layer is −2 or more and 2 or less.

3. 3. The conductive laminate according to claim 1, wherein the resin cured product contained in the colored ink layer is a cured product of a resin composition including a polyol component mainly composed of a polyester polyol and an isocyanate component mainly composed of a polyfunctional isocyanate.

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

5. The conductive laminate according to any one of claims 1 to 4, wherein the metal foil is a copper foil.

6. 6. The conductive laminate according to claim 1, wherein the coloring material is carbon black.

7. The conductive laminate according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive or adhesive layer contains a coloring material.

8. A conductive laminate described in any one of claims 1 to 7, wherein the thickness of the colored layer is 1.0 to 4.0 μm.

9. 9. The conductive laminate according to claim 1, which is used for electromagnetic shielding or earthing inside and outside electric or electronic equipment.

10. A conductive adhesive tape comprising the conductive laminate according to any one of claims 1 to 8 and a conductive adhesive layer provided on a surface of the conductive laminate on the conductive layer side.

11. The conductive pressure-sensitive adhesive tape according to claim 10, which is used for electromagnetic shielding or earthing inside and outside electric or electronic devices.

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