JP2023111946A - Conductive laminate and conductive laminated tape - Google Patents

Abstract

To provide a conductive laminate and a conductive laminated tape which can achieve both conductivity and various characteristics of insulating properties on the surface and blackness while being small in the total thickness and thin.SOLUTION: A conductive laminate has a conductive layer having facing first main surface and second main surface, a black adhesive layer provided on the first main surface of the conductive layer and an insulating part provided on the black adhesive layer. The conductive layer is a metallic foil, and the insulating part has an insulating resin layer and a black ink layer. On the surface of the conductive laminate positioned on the first main surface side of the conductive layer, brightness L* regulated by a CIE L*a*b* color system is 20 or more and 27 or less, chromaticity a* is -2 or more and 2 or less, and chromaticity b* is -2 or more and 2 or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to conductive laminates and conductive laminated tapes.

A conductive laminate, and a conductive laminated tape provided with a conductive pressure-sensitive adhesive layer on the laminate (hereinafter, the conductive laminate and the conductive laminated tape may be collectively referred to as a conductive laminate or the like. ) is easy to handle, for shielding unnecessary leakage electromagnetic waves radiated from electrical and electronic equipment, etc., for shielding harmful space electromagnetic waves generated by other electrical and electronic equipment, for grounding to prevent static electricity, etc. used for

With the miniaturization and thinning of electrical and electronic equipment, conductive laminates and the like are required to be thin with a small total thickness. In addition to being highly conductive, the conductive laminate or the like has high electromagnetic wave shielding properties, and has insulating properties on one surface in order to prevent short circuits due to contact with other members. is required.

Furthermore, in recent years, electrical and electronic devices have been improved in appearance and internal design, display image quality, image visibility, etc. In particular, the color of the electronic parts built into the device has been unified to black. Attempts have been made to improve the interior design of the interior of the vehicle. For this reason, the conductive laminate used in the part where such internal design property is required has black design property such as jet blackness and matte feeling so that it can be synchronized with the black color of the black electronic component and give a sense of unity. High surface blackness such as shielding properties is required. In addition, in this specification, the surface blackness of the conductive laminate or the like is a physical property that can be visually recognized mainly from the insulating surface side of the conductive laminate or the like.

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

Further, in Patent Document 2, an adhesive tape having a colored layer on one side of a polyethylene terephthalate film and a transparent adhesive layer on the other side is laminated to the first main surface of a soft aluminum substrate. , discloses a sheet in which a second major surface of a soft aluminum substrate is provided with a separate transparent adhesive layer.

JP-A-2014-58108 JP-A-2017-8262

The conductive sheet disclosed in Patent Literature 1 has a structure in which the base material has a resin film interposed between two metal layers, and the thickness of each metal layer is small. For this reason, it is difficult for the conductive sheet to obtain sufficient electrical conductivity and electromagnetic wave shielding properties, particularly electromagnetic wave shielding properties. In order to improve these characteristics, the thickness of the metal layer must be increased, and it is difficult to achieve both improvement in conductivity and electromagnetic wave shielding properties and reduction in the thickness of the conductive sheet. There is a problem that there is Further, in the conductive sheet disclosed in Patent Document 1, a black resin layer, which is a light-shielding insulating layer, is formed directly on a metal layer. However, in order to have high insulation and surface blackness, the thickness of the black resin layer must be increased, and both improvement in surface insulation and surface blackness and thinning of the conductive sheet are achieved. There is a problem that it is difficult to

In the sheet disclosed in Patent Document 2, the surface blackness is ensured only by the colored layer, and the thickness thereof is thin, so that it is difficult to sufficiently obtain the surface blackness. In addition, in order to improve the above characteristics, the thickness of the colored layer must be increased, and there is a problem that it is difficult to achieve both the improvement of the surface blackness and the thinning of the conductive sheet. .

The present invention has been made in view of the above-mentioned circumstances, and it is possible to achieve both electrical conductivity and electromagnetic wave shielding properties as well as surface insulation and blackness while being thin with a small total thickness. It is an object to provide a possible conductive laminate and conductive laminate tape.

The present invention provides a conductive laminate comprising a conductive layer having a first main surface and a second main surface facing each other, and a black pressure-sensitive adhesive layer provided on the first main surface of the conductive layer. and an insulating portion provided on the black adhesive layer, the conductive layer being a metal foil, the insulating portion having an insulating resin layer and a black ink layer, the conductive layer The surface of the conductive laminate located on the first main surface side of the CIE L*a*b* has a lightness L ^* defined by the CIE L ^* a ^* b ^* color system of 20 or more and 27 or less, and a chromaticity a ^* of Provided is a conductive laminate having a chromaticity b ^* of −2 or more and 2 or less and a chromaticity b* of −2 or more and 2 or less.

Further, the present invention has the above-described conductive laminate and a conductive adhesive layer, and the conductive adhesive layer is formed on the second main surface of the conductive layer constituting the conductive laminate. A conductive laminated tape is provided.

ADVANTAGE OF THE INVENTION According to the present invention, a conductive laminate and a conductive laminate capable of achieving both properties of conductivity, electromagnetic wave shielding, surface insulation and blackness while being thin with a small total thickness. A tape can be provided.

1 is a schematic cross-sectional view showing an example of a conductive laminate of the present invention; FIG. FIG. 4 is a schematic cross-sectional view showing another example of the conductive laminate of the present invention; 1 is a schematic cross-sectional view showing an example of the conductive laminated tape of the present invention; FIG. FIG. 4 is a schematic cross-sectional view showing another example of the conductive laminated tape of the present invention; FIG. 2 is a diagram showing an outline of a sample used in a method of measuring electromagnetic shielding characteristics; It is a figure which shows the outline|summary of the measuring method of electromagnetic wave shielding characteristics.

The conductive laminate and the conductive laminated tape of the present invention will be described below.

I. Conductive Laminate The conductive laminate of the present invention comprises a conductive layer having a first main surface and a second main surface facing each other, and a black adhesive provided on the first main surface of the conductive layer. and an insulating portion provided on the black adhesive layer, the conductive layer being a metal foil, and the insulating portion having an insulating resin layer and a black ink layer.

The conductive laminate of the present invention has a layer structure in which an insulating portion having a black ink layer and an insulating resin layer, a black adhesive layer, and a metal foil as a conductive layer are laminated in this order. It can exhibit high electrical conductivity, high electromagnetic wave shielding properties, and high surface insulating properties while being thin and thin. Furthermore, according to the present invention, the conductive laminate has the above-described laminate structure, so that the lightness L ^* , the chromaticities a ^* and b ^* of the surface of the insulating portion side of the conductive laminate are within predetermined ranges, respectively. and blackness can be enhanced.

In other words, in the conductive laminate of the present invention, the surface of the conductive laminate located on the first main surface side of the conductive layer is defined by the CIE L ^* a ^* b ^* color system. The lightness L ^* is 20 or more and 27 or less, the chromaticity a ^* is −2 or more and 2 or less, and the chromaticity b ^* is −2 or more and 2 or less.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to provide a conductive laminate that is thin with a small total thickness and yet achieves compatibility between the properties of conductivity, electromagnetic wave shielding, surface insulation, and blackness. can be done.

In more detail, according to the conductive laminate of the present invention, by having the above-described layer structure, the black color exhibited by the black ink layer and the black pressure-sensitive adhesive layer in the insulating portion serving as the outermost layer overlaps in plan view. Even if the total thickness of the conductive laminate is small, the surface blackness can be highly exhibited. In particular, when a metal foil is used as the conductive layer, the black color density and hue exhibited by the surface of the conductive laminate are likely to be affected by the color of the metal foil, and black design properties such as jet blackness and matt feeling can be expressed. becomes difficult. On the other hand, according to the present invention, the two layers of the black ink layer and the black pressure-sensitive adhesive layer ensure blackness, and the blackness of the two layers overlaps, so that the influence of the color of the metal foil can be suppressed. , surface blackness, especially jet-blackness and black design properties such as matt feeling can be enhanced. In addition, according to the conductive laminate of the present invention, the black ink layer that contributes to the surface blackness and the insulating resin layer that contributes to the insulation are separate layers in the insulating portion, thereby enhancing the surface blackness. Furthermore, by using a metal foil as the conductive layer, good electromagnetic wave shielding properties can be exhibited even if the total thickness is small.

Here, in the present invention, the surface blackness of the entire conductive laminate is expressed by overlapping two layers, the black ink layer and the black pressure-sensitive adhesive layer. Alternatively, for example, a method of directly forming a black ink layer on the conductive layer to develop a single black ink layer is also conceivable. However, in this method, not only the surface blackness but also the surface insulation must be ensured by the black ink layer. It can be difficult to demonstrate surface insulation. In addition, in order to improve insulation, the thickness of the black ink layer must be increased, which may make it difficult to reduce the total thickness of the conductive laminate.

As another method for expressing surface blackness, a method of adding a black coloring agent to an insulating resin layer that ensures insulation without providing a black ink layer or a black pressure-sensitive adhesive layer is also conceivable. However, in this method, it is necessary to add a large amount of the black colorant in order to develop the surface blackness, and the electrical conductivity of the colorant may reduce the insulating properties of the insulating resin layer. Moreover, if a large amount of coloring agent is added, it becomes difficult to stretch the insulating resin layer to a desired thickness, and the thickness of the insulating resin layer increases, so that the total thickness of the conductive laminate cannot be reduced. It can be difficult.

As described above, depending on the method for expressing surface blackness, thinning of the entire laminate may be hindered, or physical properties such as conductivity, insulation, and shielding properties may deteriorate. When attempting to satisfy the required properties such as conductivity, insulation and shielding properties, there is the problem that sufficient surface blackness cannot be obtained. As a result of intensive studies by the present inventors in order to eliminate such adverse effects, it was found that an insulating portion having a black ink layer and an insulating resin layer, a black adhesive layer, and a metal foil as a conductive layer. By making the layer structure laminated in this order, the total thickness is small and thin, and it is possible to achieve both of the characteristics of conductivity, electromagnetic wave shielding, surface insulation and blackness. I have come to complete the body.

The conductive laminate of the present invention has an insulating portion having a black ink layer and an insulating resin layer, a black pressure-sensitive adhesive layer, and a conductive layer in this order. Each layer will be described below.

In the conductive laminate of the present invention, the surface of the conductive laminate located on the first main surface side of the conductive layer may be referred to as the insulating portion side surface of the conductive laminate. Further, the surface of the conductive laminate located on the second main surface side of the conductive layer may be referred to as the conductive layer-side surface of the conductive laminate.

(Conductive layer)
The conductive layer in the present invention is a layer responsible for the conductivity of the conductive laminate. In the present invention, the conductive layer is metal foil. Here, the metal foil is a layer made of metal, and is a metal foil with a micro-level thickness. Since the conductive layer is a metal foil, the conductive laminate of the present invention can exhibit high electromagnetic wave shielding properties as compared with a graphite sheet, a metal deposition film, or the like.

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

In addition, the copper foil may be an electrolytic copper foil or a rolled copper foil, but it has excellent adhesiveness when used as a black adhesive layer to be laminated with a conductive layer or a conductive laminated tape described later. , electrolytic copper foil is the best.

The thickness of the conductive layer may be any size that allows the conductive laminate of the present invention to exhibit desired conductivity. The thickness is preferably 40 μm or less, more preferably 35 μm or less. More specifically, the thickness of the conductive layer is preferably 15 μm or more and 40 μm or less, more preferably 20 μm or more and 35 μm or less. By setting the thickness of the conductive layer within the above range, even if the total thickness of the conductive laminate is small, good conductivity and electromagnetic wave shielding properties can be exhibited. If the thickness of the conductive layer exceeds the above range, it may be difficult to reduce the thickness of the conductive laminate. There is

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, the black pressure-sensitive adhesive layer to be laminated with the conductive layer, or the second main surface of the conductive layer when forming a conductive laminated tape described later. This is because it can sufficiently exhibit adhesiveness to the conductive pressure-sensitive adhesive layer and the insulating pressure-sensitive adhesive layer of the thin film to be combined. The ten-point average surface roughness Rz of the conductive layer is more preferably 0.01 μm or more and 0.1 μm or more. They are 1 μm or less and 0.9 μm or less.

The arithmetic mean roughness Ra of the conductive layer is preferably 0.01 μm or more and 1.0 μm or less, more preferably 0.01 μm or more and 0.7 μm or less, and still more preferably 0.05 μm or more and 0.3 μm or less. By setting the arithmetic mean roughness Ra of the conductive layer within the above range, the black adhesive layer to be laminated with the conductive layer or the second main surface of the conductive layer when forming a conductive laminated tape described later. This is because the adhesiveness can be sufficiently exhibited with respect to the conductive pressure-sensitive adhesive layer and the insulating pressure-sensitive adhesive layer of the thin film to be laminated.

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., any three points on the surface of the conductive layer (each vertical 50 μm×50 μm in width), and the average value of three points obtained by the measurement is defined as the ten-point average surface roughness Rz and the arithmetic average roughness Ra of the conductive layer.

(Black adhesive layer)
The black pressure-sensitive adhesive layer in the present invention is a layer that is arranged between the conductive layer and the insulating portion and bonds the conductive layer and the insulating portion together. In the conductive laminate of the present invention, in addition to the black ink layer of the insulating portion, the adhesive layer that bonds the conductive layer and the adhesive layer is black, and the black ink layer and the black adhesive layer are black in plan view. By overlapping with the agent layer, it is possible to enhance the surface blackness, especially the black design, visually recognized from the insulating part side surface. As a result, it is possible to suppress an increase in the total thickness of the conductive laminate due to an improvement in surface blackness.

The black adhesive layer contains at least a black pigment and an adhesive component. The adhesive component is not particularly limited, and examples include acrylic adhesive compositions, rubber adhesive compositions, silicone adhesive compositions, urethane adhesive compositions, polyester adhesive compositions, and styrene-diene blocks. Copolymer-based pressure-sensitive adhesives, vinyl alkyl ether-based pressure-sensitive adhesive compositions, polyamide-based pressure-sensitive adhesive compositions, fluorine-based pressure-sensitive adhesive compositions, creep property-improved pressure-sensitive adhesive compositions, radiation-curable pressure-sensitive adhesive compositions, etc. can be appropriately selected and used. The pressure-sensitive adhesive component can be used alone or in combination of two or more.

Among them, it is preferable to contain an acrylic pressure-sensitive adhesive composition as a pressure-sensitive adhesive component, and the acrylic pressure-sensitive adhesive composition has a (meth)acrylic polymer (acrylic copolymer) as a base polymer and, if necessary, cross-linking A (meth)acrylic pressure-sensitive adhesive composition containing appropriate additives such as agents, tackifiers, softeners, plasticizers, fillers, anti-aging agents, colorants, etc. It is preferable because it is high.

A (meth)acrylic polymer is a polymer whose main component is a (meth)acrylic acid alkyl ester monomer. (monomers). That is, the acrylic polymer may be a homopolymer or a copolymer.

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

Examples of copolymerizable monomers copolymerizable with the (meth)alkyl ester include carboxyl groups such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. containing monomers or anhydrides thereof; sulfonic acid group-containing monomers such as sodium vinylsulfonate; aromatic vinyl compounds such as styrene and substituted styrene; cyano group-containing monomers such as acrylonitrile; ethylene, propylene, butadiene, etc. olefins; vinyl esters such as vinyl acetate; vinyl chloride; amide group-containing monomers such as acrylamide, methacrylamide, N-vinylpyrrolidone, N,N-dimethyl (meth)acrylamide; hydroxyalkyl (meth)acrylate , hydroxyl group-containing monomers such as glycerin dimethacrylate; amino group-containing monomers such as aminoethyl (meth) acrylate and (meth) acryloylmorpholine; Epoxy group-containing monomers such as meth)glycidyl acrylate and methylglycidyl (meth)acrylate; isocyanate group-containing monomers such as 2-methacryloyloxyethyl isocyanate, 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) Polyfunctional copolymerizable monomers (polyfunctional monomers) such as acrylates, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and divinylbenzene are included. The copolymerizable monomers may be used singly or in combination of two or more. A modifying monomer having a functional group such as a carboxyl group can be suitably used as the copolymerizable monomer. Those containing 0.5 to 4.0% of acrylic acid are preferable because they are excellent in adhesiveness and heat resistance.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 300,000 or more, 500,000 or more, or 600,000 or more, and the weight average molecular weight (Mw) is preferably 1,200,000 or less, 1,000,000 or less. Below, it is 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 600,000 to 900,000. Within the range is more preferable. Since the weight average molecular weight (Mw) of the (meth)acrylic polymer is within the above range, the black pressure-sensitive adhesive layer exhibits good adhesiveness and heat resistance to the conductive layer and the insulating part even when it is thin. can do.

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

The weight average molecular weight (Mw) in this specification is the value measured by the above method and conditions unless otherwise specified.

The black pressure-sensitive adhesive layer in the present invention exhibits a black color by containing a black colorant. Examples of black colorants include organic black pigments, inorganic black pigments, and black dyes. A black colorant can be used individually by 1 type or in combination of 2 or more types. In addition, the black colorant preferably has low insulating properties or low electrical conductivity. This is because the electrical conductivity of the black pressure-sensitive adhesive layer can be lowered and the surface insulation of the conductive laminate can be enhanced.

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 black pigments, and the like. Examples of organic black pigments include aniline black, azo pigments, and anthraquinone organic black pigments. Among them, carbon black is preferable as the black colorant because it has excellent light-shielding properties and dispersibility, and can exhibit high concealing properties due to the overlapping of the black ink layer and the black pressure-sensitive adhesive layer.

The content of the black colorant in the black pressure-sensitive adhesive layer is not particularly limited, and can be an amount that allows the desired surface blackness to be exhibited by overlapping with the black ink layer. % by mass), preferably 1% by mass or more and 50% by mass or less, more preferably 4% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 35% by mass or less. When the content of the black colorant in the black pressure-sensitive adhesive layer is within the above range, the insulation properties of the black pressure-sensitive adhesive layer, even if it is thin, and the adhesion to the insulating part and the conductive layer can be exhibited, and furthermore the black ink layer and can enhance the surface blackness due to the overlap of

The black pressure-sensitive adhesive layer also preferably contains a tackifying resin in order to improve the adhesive strength. By containing a tackifying resin in the black pressure-sensitive adhesive layer, the tensile strength and tensile breaking strength can be increased. The tensile strength and tensile breaking strength of the flexible laminate can be adjusted. Examples of tackifying resins include rosin-based resins such as rosin and rosin ester compounds; terpene-based resins such as diterpene polymers and α-pinene-phenol copolymers; aliphatic (C5) and aromatic ( petroleum resins such as C9); and other resins such as styrene resins, phenol resins, and xylene resins. The tackifying resin may be used singly or in combination of two or more.

Among them, when the black pressure-sensitive adhesive layer contains a (meth)acrylic polymer containing n-butyl (meth)acrylate (in other words, n-butyl (meth)acrylate) as a main monomer component, a rosin resin and It is preferable to mix and include a styrene-based resin. This is because the combined use of these two types of tackifying resins makes it easier to achieve both thinning of the black pressure-sensitive adhesive layer and high adhesive strength.

The black pressure-sensitive adhesive layer preferably contains a tackifying resin that is liquid at room temperature in order to increase the initial adhesive strength. Examples of the tackifying resin that is liquid at room temperature include liquid resins that are solid at room temperature, and low-molecular-weight liquid rubbers such as process oils, polyester plasticizers, and polybutene. A terpene phenol resin is particularly preferred. Commercially available products include YP-90L manufactured by Yasuhara Chemical Co., Ltd., and the like. The amount of the tackifying resin to be added is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the (meth)acrylic polymer.

The tackifying resin is preferably contained in an amount of 10 to 70 parts by mass, more preferably 20 to 60 parts by mass, based on 100 parts by mass of the (meth)acrylic polymer. By setting the amount of the tackifying resin within the above range, the adhesive strength of the black pressure-sensitive adhesive layer can be improved.

Although the gel fraction of the black pressure-sensitive adhesive layer is not particularly limited, it is preferably in the range of 5 to 95% by mass. This is because even if the black pressure-sensitive adhesive layer is thin, it is easy to exhibit sufficient adhesiveness. Above all, the gel fraction of the black pressure-sensitive adhesive layer is more preferably in the range of 10 to 70% by mass, still more preferably in the range of 15 to 50% by mass.

The gel fraction is obtained by immersing the cured black pressure-sensitive adhesive layer in toluene and measuring the weight of the remaining insoluble matter after drying for 24 hours, which is expressed as a percentage of the original weight.
Gel fraction (% by mass) = [(mass of black adhesive layer after toluene immersion)/(black adhesive layer before toluene immersion)] x 100

The storage elastic modulus of the black pressure-sensitive adhesive layer at 25° C. is preferably 1×10 ⁴ or more and 5×10 ⁵ Pa or less, more preferably 3×10 ⁴ or more and 1×10 ⁵ Pa or less. This is because, by setting the storage modulus of the black pressure-sensitive adhesive layer within the above range, it becomes easier to achieve both wettability (initial tack) and adhesiveness, and workability even when the layer is a thin film.

The storage elastic modulus of the black pressure-sensitive adhesive layer at 25°C can be measured with a viscoelasticity tester. More specifically, as a viscoelasticity tester, a viscoelasticity tester (Ares 2kSTD) manufactured by TA Instruments Japan Co., Ltd. can be used for measurement under the following measurement conditions.
・ Specimen thickness: 2 mm
・Frequency: 1Hz
・Compressive load: 40 to 60 g

In this specification, the storage elastic modulus at 25° C. of the black pressure-sensitive adhesive layer and other pressure-sensitive adhesive layers is the value measured by the above method and conditions unless otherwise specified.

The (meth)acrylic polymer can be prepared by a conventional polymerization method such as a solution polymerization method, an emulsion polymerization method, and an ultraviolet irradiation polymerization method.

The thickness of the black adhesive layer is preferably 0.5 µm or more, 1 µm or more, and 1.5 µm or more, and the thickness is preferably 5 µm or less, 3 µm or less, and 2.5 µm or less. More specifically, the thickness of the black adhesive 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. . By setting the thickness of the black pressure-sensitive adhesive layer within the above range, the blackness of the black pressure-sensitive adhesive layer alone is improved, and it becomes easier to achieve both adhesive strength and thinness as a conductive laminate. . In particular, when the conductive laminate of the present invention is used as an electromagnetic wave shield for electronic parts, it becomes easier to achieve both the required adhesive strength and thinness.

The black pressure-sensitive adhesive layer preferably has low conductivity or exhibits insulation. This is because by lowering the conductivity of the black pressure-sensitive adhesive layer, the insulating properties of the surface of the conductive laminate on the side of the insulating portion can be enhanced. Specifically, the surface resistivity of the black adhesive layer is preferably 1×10 ⁹ Ω/□ or more, more preferably 1×10 ¹⁰ Ω/□ or more, and more preferably 1×10 ¹¹ Ω/ □ or more is more preferable. When the surface resistivity of the black pressure-sensitive adhesive layer is within the above range, the black pressure-sensitive adhesive layer can exhibit high insulating properties, and the insulating properties exhibited by the insulating portion can be further enhanced. As a result, the conductive laminate of the present invention can exhibit higher insulating properties on the surface on the side of the insulating portion. In addition, the higher ^the surface ^resistivity of the black pressure-sensitive adhesive layer, ^the better ^. Ω/□ or less.

The surface resistivity of the black adhesive layer refers to a value measured according to JIS-K6911, using a resistivity meter (advantest digital ultra-high resistance/micro current meter R8340, TR42 box) can be measured by applying a voltage of 500V to

The hiding ratio of the black pressure-sensitive adhesive layer is not particularly limited as long as it is a size that can exhibit the desired surface blackness by overlapping with the black ink layer described later, but it is preferably 20% or more, and 30% or more. It is more preferable that it is 40% or more. Moreover, the higher the shielding rate of the black pressure-sensitive adhesive layer, the better, and the upper limit can be 100%. This is because, by setting the hiding rate of the black pressure-sensitive adhesive layer within the above range, it is possible to suppress deterioration of the blackness of the surface of the conductive laminate due to the color tone of the conductive layer.

The hiding rate of the black pressure-sensitive adhesive layer can be measured by the following method. A black pressure-sensitive adhesive layer is attached to the white and black surfaces of a hiding rate test paper (manufactured by Nippon Test Panel Kogyo Co., Ltd.), and the color measurement method specified in JIS-Z-8722 is applied to the white and black surfaces. Among the tristimulus values of the black pressure-sensitive adhesive layer, the Y value indicating brightness is measured. A colorimetric gloss meter "CM-3500d" (manufactured by Minolta) is used to measure the standard light C in a 2-degree field of view. The hiding rate can be measured by applying the measured Y value to the following formula.
Hiding rate (%) = (Y value of black pressure-sensitive adhesive layer attached to black surface/Y value of black pressure-sensitive adhesive layer attached to white surface) x 100%

The black pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive in which a black colorant is dispersed onto the conductive layer or resin film. Coating methods include gravure coating, comma coating, bar coating, die coating, lip coating, screen coating and the like. Among them, gravure coating is preferred for thin film coating, and microgravure coating is most preferred.

(Insulating part)
The insulating part in the present invention is a layer provided on the first main surface of the conductive layer with the black adhesive layer interposed therebetween. Moreover, the insulating portion serves as one outermost layer of the conductive laminate of the present invention. The insulating part in the present invention has an insulating resin layer and a black ink layer.

In the conductive laminate of the present invention, the order of lamination of the insulating resin layer and the black ink layer in the insulating part is not limited, and the black ink layer and the insulating resin layer are arranged in this order from the black pressure-sensitive adhesive layer side. and the insulating resin layer and the black ink layer may be laminated in this order from the black adhesive layer side.

FIG. 1 is a schematic cross-sectional view showing an example of the conductive laminate of the present invention, showing an example in which the insulating resin layer and the black ink layer are laminated in this order from the black pressure-sensitive adhesive layer side. there is The conductive laminate 10 of the present invention illustrated in FIG. 1 includes a conductive layer 1 having first and second main surfaces facing each other, and a black It has an adhesive layer 2 and an insulating part 3 provided on the black adhesive layer 2 and having an insulating resin layer 4 and a black ink layer 5, and the conductive layer 1 is a metal foil and a black adhesive An insulating resin layer 4 and a black ink layer 5 are laminated in this order from the layer 2 side.

Further, FIG. 2 is a schematic cross-sectional view showing another example of the conductive laminate of the present invention, in which the black ink layer and the insulating resin layer are laminated in this order from the black pressure-sensitive adhesive layer side. shows an example. A conductive laminate 10 of the present invention illustrated in FIG. 2 includes a conductive layer 1 having first and second main surfaces facing each other, and a It has a black adhesive layer 2 and an insulating part 3 provided on the black adhesive layer 2 and having an insulating resin layer 4 and a black ink layer 5, and the conductive layer 1 is a metal foil and a black adhesive An insulating resin layer 4 and a black ink layer 5 are laminated in this order from the agent layer 2 side.

Above all, it is preferable that the insulating portion is formed by laminating the insulating resin layer and the black ink layer in this order from the black pressure-sensitive adhesive layer side. By arranging the black ink layer on the surface of the insulating resin layer opposite to the conductive layer side, the black ink layer is positioned on the outermost side of the conductive laminate and overlaps with the black adhesive layer. This is because the black ink layer enables further adjustment of the surface blackness of the electroconductive laminate.

The insulating resin layer constituting the insulating part in the present invention is not particularly limited, but a known insulating resin film can be used. Specific examples include polyester films, polyimide films, polyamide films, polyurethane films, polyolefin films, and the like. Among them, a polyester film or a polyimide film is preferable because it is thin and maintains insulation while being resistant to breakage, and a polyester film is particularly preferable because it can be made thinner and has excellent insulation.

The thickness of the insulating resin layer is not particularly limited as long as it has a size capable of exhibiting desired insulating properties, but it is preferably 1 μm or more, 1.5 μm or more, or 2 μm or more. Further, the thickness is preferably 5 μm or less, 4.5 μm or less, 4 μm or less, 3.5 μm or less, 3 μm or less, or 2.5 μm or less. More specifically, the thickness of the insulating resin layer is preferably 1 μm or more and 5 μm or less, more 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 when the thickness of the insulating resin layer is within the above range, it is easy to exhibit high insulating properties.

Further, the black ink layer forming the insulating portion in the present invention contains at least a black pigment and a binder resin. The black ink layer is formed of black ink in which a known black pigment is dispersed in resin varnish.

A black pigment can be used individually by 1 type or in combination of 2 or more types. Moreover, it is preferable that the black pigment has low insulating properties or low electrical conductivity. This is because the electrical conductivity of the black ink layer can be lowered and the surface insulation of the conductive laminate can be enhanced.

A known material can be used as the black pigment, and it may be an organic black pigment or an inorganic black pigment. Examples of inorganic black pigments include carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, etc.), graphite, metal oxides (chromium oxide, iron oxide, copper oxide, etc., manganese dioxide, etc.), and aniline. Black, perylene black, titanium black, cyanine black, activated carbon, ferrite, magnetite, molybdenum disulfide, chromium complexes, composite oxide black pigments, and the like. Examples of organic black pigments include aniline black, azo pigments, and anthraquinone organic black pigments.

Above all, the black ink layer preferably contains at least one black pigment selected from carbon black and azo pigments. This is because carbon black is preferable because it can enhance blackness. In addition, the azo pigment is preferable because it can increase the insulating property. Among them, it is more preferable to contain both carbon black and azo pigment.

The content of the black pigment may be an amount that allows the black ink layer and the black pressure-sensitive adhesive layer to overlap to exhibit the desired blackness, particularly the black design, for example, in the total amount (100% by mass) of the black ink layer. , preferably 1% by mass or more and 95% by mass or less, preferably 10% by mass or more and 90% by mass or less, and preferably 20% by mass or more and 80% by mass or less. This is because the black ink layer can exhibit the desired surface blackness by setting the content of the black pigment within the above range.

As the binder resin, known resins used for inks can be applied, and one type of binder resin may be used alone, or two or more types may be used in combination. Examples of binder resins include polyurethane resins, polyester resins, acrylic resins, vinyl chloride-vinyl acetate copolymer resins, and nitrocellulose resins. Among these resins, polyurethane resins and polyester resins are preferable because of their excellent adhesion, and polyurethane resins are more preferable because they have good flexibility and adhesion to the insulating resin layer.

Polyurethane resin is obtained by polycondensation reaction of a diisocyanate compound, a polyol compound, a low-molecular-weight chain extender, etc., and is a flexible and elastic resin having many urethane bonds in the molecule. The polyurethane resin used as the binder resin preferably has a weight average molecular weight within the range of 1,000 to 500,000, more preferably within the range of 30,000 to 100,000.

Diisocyanate compounds for forming polyurethane resins include, for example, methylene diisocyanate, isopropylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and the carboxyl group of dimer acid. Chain aliphatic diisocyanates such as dimer diisocyanate substituted with isocyanate groups; cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-di(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate cycloaliphatic diisocyanates such as; dialkyldiphenylmethane diisocyanates such as 4,4′-diphenyldimethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanates such as 4,4′-diphenyltetramethylmethane diisocyanate, 1,5-naphthylene diisocyanate, 4,4 '-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, m-tetramethyl Aromatic diisocyanates such as xylylene diisocyanate; amino acid diisocyanates such as lysine diisocyanate; The polyisocyanate compounds including these diisocyanate compounds may be used alone or in combination of two or more.

Polyol compounds for forming polyurethane resins include, for example, polyether polyols, polyester polyols, polycarbonate polyols, polybutadiene polyols and the like. Examples of polyether polyols include polyethylene glycol, polypropylene glycol, and polyoxytetramethylene ether glycol obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran, and the like. Examples of polyester polyols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, Saturated or unsaturated low molecular weight glycols such as 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, 1,4-butynediol, dipropylene glycol, bisphenol A, and hydrogenated bisphenol A and dibasic acids such as adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, azelaic acid, sebacic acid, and suberic acid, or these and compounds obtained by dehydration condensation of acid anhydrides corresponding to the above.

The black ink layer can contain known materials used in general-purpose ink compositions, in addition to the black pigment and binder resin described above. Examples of known materials include dispersants such as cellulose resins; various isocyanate curing agents; particulate antiblocking agents such as silica, calcium carbonate, calcium phosphate, talc, urethane beads, acrylic beads, and silicone beads; Antiblocking agents such as wax (PE wax), fatty acid amides, fatty acid esters, organic compound antiblocking agents such as higher fatty acids;

The thickness of the black ink layer may be any size as long as the desired black design property can be exhibited by overlapping with the black pressure-sensitive adhesive layer. Specifically, the thickness of the black ink layer is preferably 1 μm or more. , 1.2 μm or more and 1.5 μm or more, and the thickness is preferably 3 μm or less, 2.5 μm or less, and 2 μm or less. More specifically, the thickness of the black ink layer is preferably 1 μm or more and 3 μm or less, more preferably 1 μm or more and 2 μm or less, and more preferably 1.2 μm or more and 2 μm or less. By setting the thickness of the black ink layer within the above range, both thinness and surface blackness can be achieved.

The concealment rate of the black ink layer is not particularly limited as long as it is a size that allows the desired surface blackness to be exhibited by overlapping with the black pressure-sensitive adhesive layer described above, but is preferably 70% or more, and 80% or more. is more preferably 90% or more. Moreover, the higher the shielding rate of the black ink layer, the better, and the upper limit can be 100%. By setting the hiding rate of the black ink layer within the above range, it is possible to suppress the influence of the color tone of the conductive layer from appearing on the surface of the conductive laminate, making it easier to control the blackness.

The hiding rate of the black ink layer can be measured by the same method as that for measuring the hiding rate of the black pressure-sensitive adhesive layer.

The insulating portion in the present invention can be provided with a matte layer in addition to the black ink layer and the insulating resin layer described above. By providing the matte layer, each physical property of lightness L ^* , chromaticity a ^* , chromaticity b ^* , and 60° gloss value can be adjusted. In particular, it is preferable to provide a matte layer for adjusting the 60° gloss value.

The matte layer is a layer containing a resin binder and fine particles. Examples of fine particles include general-purpose fine particles such as silica, calcium carbonate, and barium sulfate. Also, as the resin binder, a resin commonly used for the matte layer can be used. Above all, the matte layer is preferably a urethane-based resin in which silica particles are dispersed.

The thickness of the matte layer is not particularly limited as long as the desired function can be exhibited, and is preferably 0.3 μm or more, 0.4 μm or more, or 0.5 μm or more. Moreover, the thickness of the matte layer may be any size that does not greatly affect the total thickness of the conductive laminate, and is preferably 3 μm or less, 2 μm or less, or 1.5 μm or less. More specifically, the thickness of the matte layer is preferably 0.3 μm or more and 3 μm or less, and more preferably 0.5 μm or more and 1.5 μm or less.

When the insulating part further has a matte layer, the insulating part may be formed by laminating the insulating resin layer, the black ink layer, and the matte layer in this order from the black pressure-sensitive adhesive layer side. , the black ink layer, the insulating resin layer, and the matte layer may be laminated in this order from the black adhesive layer side. Above all, it is preferable that the insulating portion is formed by laminating the insulating resin layer, the black ink layer, and the matte layer in this order from the black pressure-sensitive adhesive layer side. This is because the surface blackness of the conductive laminate can be further adjusted by overlapping with the black pressure-sensitive adhesive layer with the black ink layer and the matte layer.

The total thickness of the insulating portion in the present invention is preferably 3 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less, and more preferably 5 μm or more and 7 μm or less. This is because, by setting the total thickness of the insulating portion within the above range, the physical properties of the insulating portion and the blackness can be exhibited in a well-balanced manner.

The insulating part in the present invention preferably has a surface resistivity of 1×10 ⁹ Ω/□ or more, more preferably 1×10 ¹⁰ Ω/□ or more, and more preferably 1×10 ¹¹ Ω/□ or more. is more preferable. When the surface resistivity of the insulating portion is within the above range, the conductive laminate of the present invention can maintain higher insulating properties on the surface on the insulating portion side. Incidentally, ^the higher ^the surface ^resistivity of ^the insulating part is, the better. □ It can be less than or equal to.

The surface resistivity of the insulating part refers to the value measured according to JIS-K6911, using a resistivity meter (Advantest digital ultra-high resistance/micro current meter R8340, TR42 box), 500 V on the black adhesive layer can be measured by applying a voltage of

The insulating portion in the present invention is obtained by applying a black ink in which a black pigment is dispersed in a binder resin to the surface of a resin film as an insulating resin layer to form a black ink layer. The coating method may be a known and commonly used coating method and is not particularly limited, but the gravure coating method is most preferred.

When the insulating part in the present invention further has a matting layer on the black ink layer, the matting layer contains a matting agent (matting agent) in which fine particles such as silica are dispersed in a resin binder. The surface treatment agent can be formed by coating the surface of the black ink layer.

(Conductive laminate)
The conductive laminate of the present invention preferably has a total thickness of 20 µm or more, more preferably 25 µm or more, and even more preferably 30 µm or more. The total thickness is preferably 40 μm or less, more preferably 38 μm or less, and even more preferably 36 μm or less. More specifically, the conductive laminate of the present invention preferably has a total thickness of 20 μm or more and 40 μm or less, more preferably 25 μm or more and 38 μm or less, and even more preferably 30 μm or more and 36 μm or less. By setting the total thickness of the conductive laminate within the above range, it is possible to achieve both of the characteristics of electrical conductivity and electromagnetic wave shielding, as well as surface insulation and blackness, while the total thickness is small and thin. be able to.

The conductive laminate of the present invention has the layer structure described above, and the surface of the conductive laminate located on the first main surface side of the conductive layer (that is, the insulating portion side surface of the conductive laminate) , the lightness L ^* , the chromaticity a ^* , and the chromaticity b ^* defined in the CIE L ^* a ^* b ^* color system each exhibit a predetermined value, so that the color of the conductive layer is suppressed, and the conductivity The surface of the laminate on the insulating part side is excellent in color density and hue, and can exhibit a black color with a high texture. As a result, the conductive laminate of the present invention is thin, yet satisfactorily satisfies the properties of conductivity, insulation, electromagnetic wave shielding, etc., and exhibits excellent surface blackness, particularly black design. can.

In the conductive laminate of the present invention, the surface of the conductive laminate located on the first main surface side of the conductive layer has a lightness L ^* defined by the CIE L ^* a ^* b ^* color system. It may be 20 or more, preferably 21 or more, 21.5 or more, 22 or more, or 22.5 or more. Also, the lightness L ^* may be 27 or less, preferably 25 or less, 24 or less, or 23 or less. More specifically, the lightness L ^* may be 20 or more and 27 or less, preferably 21 or more and 25 or less, more preferably 21.5 or more and 24 or less, and more preferably 22 or more and 23 or less. The conductive laminate of the present invention has a lightness L ^* measured from the insulating part side surface within the above range, so that the conductive laminate can exhibit a black design with excellent jet-blackness, and can be used as a black part. When used together, it is possible to create a sense of unity with the black color exhibited by the black part.

In the conductive laminate of the present invention, the surface of the conductive laminate located on the first main surface side of the conductive layer has a chromaticity a ^* defined by the CIE L ^* a ^* b ^* color system. is -2 or more, preferably -1.5 or more, -1 or more, -0.5 or more, or 0 or more. Also, the chromaticity a ^* may be 2 or less, preferably 1.5 or less, 1 or less, or 0.5 or less. More specifically, the chromaticity a ^* may be -2 or more and 2 or less, preferably -1 or more and 1 or less, and 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 insulating part side surface within the above range, so that it can exhibit excellent black design as a conductive laminate, and can be used with black parts. It is possible to create a sense of unity with the black color exhibited by the black component when the black component is used.

In the conductive laminate of the present invention, the surface of the conductive laminate located on the first main surface side of the conductive layer has a chromaticity b ^* defined by the CIE L ^* a ^* b ^* color system. is -2 or more, preferably -1.5 or more, or -1 or more. Also, the chromaticity b ^* may be 2 or less, preferably 1.5 or less, 1 or less, 0.5 or less, or 0 or less. More specifically, the chromaticity b ^* may be -2 or more and 2 or less, preferably -2 or more and 0 or less, -1.5 or more and 0.5 or less, -1.5 or more and 0 or less, -1 or more 0 or less. The conductive laminate of the present invention has a chromaticity b ^* measured from the insulating part side surface within the above range, so that it can exhibit excellent black design as a conductive laminate, and can be used with black parts. It is possible to create a sense of unity with the black color exhibited by the black component when the black component is used.

In the conductive laminate of the present invention, the surface of the conductive laminate located on the first main surface side of the conductive layer has a lightness L ^* defined by the CIE L ^* a ^* b ^* color system. 20 or more and 27 or less, chromaticity a ^* is −2 or more and 2 or less, and chromaticity b ^* is −2 or more and 2 or less, but lightness L ^* is 21 or more and 25 or less, and chromaticity a ^* is -1 or more and 1 or less, chromaticity b ^* is preferably -1.5 or more and 0.5 or less, lightness L ^* is 21.5 or more and 24 or less, and chromaticity a ^* is - More preferably, it is 0.5 or more and 0.5 or less, and the chromaticity b ^* is -1 or more and 0 or less.

The CIE color values (L ^* , a ^* , b ^* ) of the conductive laminate of the present invention can be measured according to JIS Z8722. Specifically, it is a value measured from the insulating part side surface of the conductive laminate according to the measurement standard JIS Z 8722 with a C spectrum of 2° using a SPECTROPHOTOMETER CM-5 manufactured by KONICA MINOLTA.

In the conductive laminate of the present invention, the surface of the conductive laminate located on the first main surface side of the conductive layer preferably has a 60° gloss value of 1 or more and 5 or less. It is preferably 4 or less, more preferably 1 or more and 3 or less. In the conductive laminate of the present invention, since the 60° C. gloss value measured from the surface on the insulating portion side is within the above range, glossiness is suppressed and the conductive laminate can exhibit an excellent matte design. , When used together with black parts, it is possible to suppress conspicuousness due to glossiness and to give a sense of unity with the black color exhibited by black parts.

The 60° gloss value is the glossiness measured at a set angle of 60° according to JIS Z 8741 with respect to the insulating part side surface of the conductive laminate. The measurement can be performed using a commercially available measuring device (eg Cat No. 4563 micro-TRI-gloss meter manufactured by BYK).

In addition, the conductive laminate of the present invention has the above-described layer structure, so that the surface of the conductive laminate located on the first main surface side of the conductive layer (that is, the insulating portion) is thin while being thin. On the other hand, the surface of the conductive laminate located on the second main surface side of the conductive layer (that is, the conductive layer side surface) exhibits high conductivity. can.

In the conductive laminate of the present invention, the surface resistivity of the surface of the conductive laminate located on the first main surface side of the conductive layer (that is, the insulating portion side surface) is 1×10 ⁸ Ω/□ or more. is preferably 1×10 ⁹ Ω/□ or more, more preferably 1×10 ¹⁰ Ω/□ or more, and more preferably 1×10 ¹¹ Ω/□ or more. Since the surface resistivity of the surface on the side of the insulating portion of the conductive laminate of the present invention is within the above range, the surface on the side of the insulating portion can exhibit higher insulating properties. Incidentally, the higher the surface resistivity of the insulating portion side surface of the conductive laminate, the better, but generally 1×10 ¹⁸ Ω/□ or less, 1×10 ¹⁶ Ω/□ or less, or 1×10 ¹⁴ Ω/□ or less. , 1×10 ¹² Ω/□ or less.

Further, in the conductive laminate of the present invention, the surface resistivity of the surface of the conductive laminate located on the second main surface side of the conductive layer (that is, the surface on the conductive layer side) is 10 mΩ/□ or less. is preferably 1 mΩ/□ or less, and more preferably 0.6 mΩ/□ or less. Since the conductive layer-side surface has a surface resistivity within the above range, the conductive layered product of the present invention can exhibit higher conductivity on the conductive layer-side surface. The surface resistivity of the conductive layer side surface of the conductive laminate is preferably as small as possible, but generally it can be 0.001 mΩ/□ or more.

The surface resistivity of the insulating part side surface and the conductive layer side surface of the conductive laminate refers to values measured according to JIS-K6911, respectively, using a resistivity meter (Mitsubishi Chemical Lorestar MCP-T600). can be measured by applying a four-terminal probe to the insulating part side surface or the conductive layer side surface of the conductive laminate.

(Method for manufacturing conductive laminate)
The method for producing the conductive laminate of the present invention is not particularly limited. Among them, a step of preparing black ink and a black adhesive, and a step of forming an insulating portion by applying black ink to one surface of the insulating resin layer to form an insulating portion having a black ink layer and an insulating resin layer. , a black adhesive layer forming step of applying the black adhesive to the surface of the insulating portion opposite to the black ink layer to form a black adhesive layer; and a conductive layer on the black adhesive layer. A manufacturing method having a conductive layer forming step of laminating a metal foil as is preferable because it is possible to manufacture a conductive laminate while suppressing the occurrence of wrinkles, and is excellent in productivity.

In the insulating portion forming step, the method of applying black ink to the insulating resin layer is not particularly limited as long as the thickness of the black ink layer after drying reaches a desired size. For example, a gravure coating method or the like can be used. .

In addition, in the black pressure-sensitive adhesive layer forming step, the method of applying the black pressure-sensitive adhesive is not particularly limited as long as the thickness of the black pressure-sensitive adhesive layer after drying reaches a desired size. A known method such as a lip coating method can be used.

(Application of conductive laminate)
The conductive laminate of the present invention is thin and excellent in conductivity, insulation, and surface blackness. It can be widely applied to applications where these properties are required. Among others, it can be suitably used for shielding and grounding applications such as thin mobile devices.

II. Conductive laminated tape The conductive laminated tape of the present invention has the conductive laminate described in the section "I. Conductive laminate" and a conductive pressure-sensitive adhesive layer, and the conductive pressure-sensitive adhesive layer is , provided on the second main surface of the conductive layer forming the conductive laminate.

According to the conductive laminated tape of the present invention, it is possible to achieve both properties of conductivity, electromagnetic wave shielding, surface insulation and blackness while being thin with a small total thickness.

(Conductive laminate)
The conductive laminate in the present invention is the same as the details described in the above section "I. Conductive laminate", so the description is omitted here.

(Conductive adhesive layer)
The conductive pressure-sensitive adhesive layer in the present invention contains a pressure-sensitive adhesive component and a conductive filler.

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

The content of the conductive filler in the conductive pressure-sensitive adhesive layer can be an amount that can exhibit the desired conductivity, and is not particularly limited, but the total amount of the conductive pressure-sensitive adhesive layer (100% by mass ), preferably in the range of 0.1% by mass to 80% by mass, preferably in the range of 0.5% by mass to 40% by mass, most preferably in the range of 0.8% by mass to 10% by mass. preferable. 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 if the film is thin.

The adhesive component constituting the conductive adhesive layer is not particularly limited, and examples thereof include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, and styrene-diene blocks. The adhesive may be appropriately selected from known adhesives such as copolymer-based adhesives, vinyl alkyl ether-based adhesives, polyamide-based adhesives, fluorine-based adhesives, creep property-improved adhesives, and radiation-curable adhesives. can be done. The pressure-sensitive adhesive component can be used alone or in combination of two or more.

Among them, acrylic pressure-sensitive adhesives can be preferably used as the pressure-sensitive adhesive component because of their high adhesion reliability. Acrylic pressure-sensitive adhesives have a (meth)acrylic polymer as an adhesive component or main agent, and if necessary, a cross-linking agent, a tackifier, a softening agent, a plasticizer, a filler, an anti-aging agent, a coloring agent, etc. contains appropriate additives. A (meth)acrylic polymer is a polymer whose main monomer component is a (meth)acrylic acid alkyl ester. (monomers) are prepared by using

As the acrylic copolymer, an acrylic copolymer containing a (meth)acrylate monomer having 1 to 14 carbon atoms as a main monomer component can be preferably used. 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, Examples include monomers such as isooctyl (meth)acrylate, isononyl (meth)acrylate, cyclohexyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, and one or more of these may be used. Among them, (meth)acrylates having an alkyl group with 4 to 12 carbon atoms are preferable, and (meth)acrylates having a straight or branched structure with 4 to 9 carbon atoms are more preferable. Among them, n-butyl acrylate and 2-ethylhexyl acrylate are preferably used, and these may be used alone or in combination.

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

Further, the acrylic copolymer is preferably copolymerized with a highly polar vinyl monomer, and examples of the highly polar vinyl monomer include a vinyl monomer having a carboxyl group, a vinyl monomer having a hydroxyl group, a vinyl monomer having an amide group, and the like. and one or more of these are used. Among them, a carboxyl group-containing monomer can be preferably used because it is easy to adjust the adhesiveness of the pressure-sensitive adhesive to a suitable range.

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. It is preferably used as a polymerization component.

When a vinyl monomer having a carboxyl group is used, its content is preferably 0.2% by mass to 15% by mass, preferably 0.4% by mass, in the monomer components constituting the acrylic copolymer. It is more preferably 10% by mass, and even more preferably 0.5% by mass to 6% by mass. By containing in the said range, it is easy to adjust the adhesiveness of an adhesive to a suitable range.

Examples of monomers having a hydroxyl group include hydroxyl group-containing ( Meth)acrylates can be used.

Examples of monomers having an amide group include N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, acrylamide, N,N-dimethylacrylamide, and the like.

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, 2-methoxyethyl (meth)acrylate, 2-phenoxyethyl ( Terminal alkoxy-modified (meth)acrylates such as meth)acrylates can be mentioned.

The content of the highly polar vinyl monomer is preferably 0.2% by mass to 15% by mass, more preferably 0.4% by mass to 10% by mass, in the total amount of the monomer components constituting the acrylic copolymer. is more preferable, and 0.5% by mass to 6% by mass is even more preferable. By containing in the said range, it is easy to adjust the adhesiveness of an adhesive to a suitable range.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 500,000 or more, 600,000 or more, or 700,000 or more. The weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably 2 million or less, 1.8 million or less, 1.6 million or less, 1.2 million or less, and 1 million or less. By setting the weight average molecular weight (Mw) of the (meth)acrylic polymer within the above range, the conductive pressure-sensitive adhesive layer can have good initial adhesion to the conductive layer in the conductive laminate. More specifically, the weight average molecular weight (Mw) of the (meth)acrylic polymer is preferably in the range of 500,000 to 1,200,000, more preferably in the range of 500,000 to 1,000,000.

The (meth)acrylic polymer can be prepared by a conventional polymerization method such as a solution polymerization method, an emulsion polymerization method, and an ultraviolet irradiation polymerization method.

A tackifying resin may be added to the conductive pressure-sensitive adhesive layer in order to improve the adhesive strength. Examples of tackifying resins include rosin-based resins such as rosin and rosin ester compounds; terpene-based resins such as diterpene polymers and α-pinene-phenol copolymers; aliphatic (C5) and aromatic ( petroleum resins such as C9); styrene resins; phenol resins; xylene resins; and methacrylic resins. Among them, it is preferable to contain a rosin-based resin, and it is more preferable to contain a polymerized rosin-based resin, in order to improve the adhesion force while being thin. Moreover, in addition to the rosin-based resin, a styrene-based resin may be mixed and included.

Further, in order to increase the initial adhesive strength, it is preferable to mix and use a tackifying resin that is liquid at room temperature. Examples of the tackifying resin that is liquid at room temperature include the liquid resins of the tackifying resins described above, process oils, polyester plasticizers, and low-molecular-weight liquid rubbers such as polybutene. A terpene phenol resin is particularly preferred. Commercially available products include YP-90L manufactured by Yasuhara Chemical Co., Ltd., and the like.

The amount of the tackifying resin to be added is preferably in the range of 10 parts by mass to 70 parts by mass with respect to 100 parts by mass of the acrylic copolymer. More preferably, it is within the range of 20 parts by mass to 60 parts by mass. Adhesion can be improved by adding a tackifying resin within the above range.

The gel fraction of the conductive pressure-sensitive adhesive layer is not particularly limited, but it is preferably 10 to 60% by mass because it is easy to develop sufficient adhesiveness even if it is thin, and is preferably 20 to 50% by mass. is more preferably 25 to 45% by mass.

The gel fraction of the conductive pressure-sensitive adhesive layer is obtained by immersing the conductive pressure-sensitive adhesive layer after curing in toluene, measuring the mass of the remaining insoluble matter after drying after standing for 24 hours, and expressing it as a percentage of the original mass. .
Gel fraction (% by mass) = [(mass of conductive adhesive layer after toluene immersion)/(conductive adhesive layer before toluene immersion)] x 100

The storage elastic modulus of the conductive pressure-sensitive adhesive layer at 25° C. is preferably 1×10 ⁴ or more and 5×10 ⁵ Pa or less, more preferably 2×10 ⁴ or more and 1×10 ⁵ Pa or less. This is because when the storage elastic modulus of the conductive pressure-sensitive adhesive layer at 25° C. is within the above range, it is easy to achieve a high level of both adhesion and workability even with a thin conductive pressure-sensitive adhesive layer. The storage elastic modulus of the conductive pressure-sensitive adhesive layer at 25°C is a value measured by the same method and under the same conditions as the method for measuring the storage elastic modulus of the black pressure-sensitive adhesive layer at 25°C.

The conductive pressure-sensitive adhesive layer may have a single-layer structure, or may have a multilayer structure in which conductive pressure-sensitive adhesive layers are provided on both sides of a conductive substrate.

When the conductive pressure-sensitive adhesive layer has a multi-layer structure, examples of the conductive base material include a metal foil base material and a base material obtained by plating a wet polyester non-woven fabric base material. Materials for the metal foil include gold, silver, copper, aluminum, nickel, iron, tin, and alloys thereof. Moreover, examples of the base material obtained by plating the wet polyester nonwoven fabric base material include those using electroless metal plating as the plating. Examples of plating metals include copper, nickel, silver, platinum and aluminum. Among them, copper or nickel is preferable from the viewpoint of conductivity and cost. The thickness of the conductive substrate is not particularly limited, but can be, for example, 1 μm or more and 50 μm or less.

The thickness of the conductive pressure-sensitive adhesive layer can be set to a size that can exhibit conductivity and pressure-sensitive adhesive, and is 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 pressure-sensitive adhesive layer within the above range, the total thickness of the conductive laminated tape of the present invention can be reduced while the conductivity can be further increased.

Moreover, when the conductive pressure-sensitive 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.

The conductive pressure-sensitive adhesive layer is provided on the second main surface of the conductive layer in the conductive laminate. As illustrated in FIG. 3, the conductive pressure-sensitive adhesive layer 11 may be provided on the entire second main surface of the conductive layer 1 in the conductive laminate 10, and as illustrated in FIG. , the conductive pressure-sensitive adhesive layer 11 may be provided in a pattern on the second main surface of the conductive layer 1 in the conductive laminate 10 . In the latter case, the insulating pressure-sensitive adhesive layer 12 is arranged in a region where the conductive pressure-sensitive adhesive layer 11 on the second main surface of the conductive layer 1 is not arranged. The conductive adhesive layers 11 and the insulating adhesive layers 12 may be alternately arranged in a pattern on the main surface of the substrate. An aspect in which the conductive pressure-sensitive adhesive layer and the insulating pressure-sensitive adhesive layer are alternately arranged in a pattern is preferable because it can improve adhesiveness.

When the conductive pressure-sensitive adhesive layer and the insulating pressure-sensitive adhesive layer are alternately arranged in a pattern on the second main surface of the conductive layer, the insulating pressure-sensitive adhesive layer is the conductive pressure-sensitive adhesive layer. It can be the same as the conductive pressure-sensitive adhesive layer except that it does not contain a conductive filler.

(any configuration)
The electrically conductive laminated tape of the present invention includes at least the electrically conductive laminate and the electrically conductive pressure-sensitive adhesive layer described above, but may also include other configurations. For example, a release layer may be further provided on the surface of the conductive pressure-sensitive adhesive layer opposite to the conductive laminate. This is because the conductive laminated tape can be protected by providing the release layer.

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

The surface of the release layer is preferably subjected to a release treatment in order to impart easy releasability. Specifically, the surface of the release layer is preferably provided with a release treatment layer. The release treatment layer can be formed from a general-purpose release treatment agent used for release layers of double-sided adhesive tapes. Examples of such release agents include silicone-based, fluorine-based, and long-chain alkyl-based release agents. The release treatment layer may be formed by lamination or coating.

The peeling force of the peeling layer may be appropriately adjusted according to the mode of use, etc., but the peeling force with respect to the conductive laminated tape is 0.01 N/20 mm to 2 N/20 mm, preferably 0.05 N/20 mm to 0.15 N/ It can be 20 mm. This is because deformation of the conductive laminated tape can be easily suppressed when the release layer is peeled off. The peel force was measured by lining the exposed surface of the conductive pressure-sensitive adhesive layer of the conductive laminated tape with a PET film having a thickness of 50 μm as a release layer, and peeling it in the direction of 180° at a speed of 0.3 m/min to 10 m/min. can be measured by

(Conductive laminated tape)
The conductive laminated tape of the present invention preferably has a total thickness of 22 μm or more and 100 μm or less, more preferably 25 μm or more and 50 μm or less, and even more preferably 30 μm or more and 45 μm or less. By setting the total thickness of the conductive laminated tape within the above range, it is possible to achieve both of the characteristics of electrical conductivity and electromagnetic wave shielding, as well as surface insulation and blackness, while keeping the total thickness small and thin. be able to. The total thickness of the conductive pressure-sensitive adhesive tape referred to in this specification does not include the thickness of the release layer.

The conductive laminated tape of the present invention has lightness L ^{*, chromaticity a* ,} and chromaticity b ^* defined by the CIE L ^* a ^* b ^* color system measured from the surface of the conductive laminate side. CIE L ^* a ^* b measured from the insulating part side surface of the conductive laminate described in the above section "I. Conductive laminate" * Lightness L ^* and chromaticity ^{a* defined} by the color system , chromaticity b ^* .

Further, in the conductive laminate tape of the present invention, the 60° gloss value measured from the surface of the conductive laminate side is It is preferably within the 60° gloss value measured from the surface.

The CIE color values (L ^* , a ^* , b ^* ) and the 60° gloss value of the conductive laminate tape of the present invention are the CIE values of the conductive laminate described in the section "I. Conductive laminate" above. These are values measured by the same method and under the same conditions as those for measuring color values (L ^* , a ^* , b ^* ) and 60° gloss values.

In the conductive laminate tape of the present invention, the hiding rate measured from the surface on the side of the conductive laminate is measured from the surface on the insulating part side of the conductive laminate described in the section "I. Conductive laminate" above. is preferably within the range of the concealment ratio. The hiding rate of the conductive laminated tape is measured by the same method and under the same conditions as the method for measuring the hiding rate from the insulating part side surface of the conductive laminated body described in the section "I. Conductive laminated body" above. value.

In the conductive laminate tape of the present invention, the surface resistivity measured from the surface of the conductive laminate side is measured from the insulating part side surface of the conductive laminate described in the section "I. Conductive laminate" above. is preferably within the range of surface resistivities specified by

In addition, the conductive laminated tape of the present invention preferably has a surface resistivity of 10 mΩ/□ or less, more preferably 1 mΩ/□ or less, and 0.6 mΩ as measured from the conductive pressure-sensitive adhesive side surface. /□ or less is more preferable. Incidentally, the smaller the surface resistivity measured from the conductive adhesive side surface of the conductive laminated tape, the better, but generally it can be 0.001 mΩ/□ or more.

The surface resistivity of the conductive laminated body side surface and the conductive adhesive layer side surface of the conductive laminated tape refers to the value measured according to JIS-K6911, respectively. -T600), the measurement can be performed by applying a four-terminal probe to the conductive laminated body side surface or the conductive pressure sensitive adhesive layer side surface of the conductive laminated tape.

(Manufacturing method of conductive laminated tape)
The method for producing the conductive adhesive sheet of the present invention is not particularly limited. The conductive adhesive sheet of the present invention can be obtained, for example, by preparing a conductive adhesive containing a conductive filler and an adhesive component by preparing a conductive laminate as described in the section "I. Conductive laminate" above. A step of applying a conductive pressure-sensitive adhesive to the second main surface of the conductive layer in the conductive laminate so that the thickness after drying becomes a desired size to form a conductive pressure-sensitive adhesive layer; It can be manufactured using a manufacturing method having

In addition, the conductive adhesive sheet of the present invention can be obtained, for example, by the step of preparing the conductive laminate described in the above section "I. Conductive laminate", the conductive adhesive containing the conductive filler and the adhesive component. A step of preparing, a step of applying a conductive adhesive to both sides of the conductive substrate so that the thickness after drying becomes a desired size to form a conductive double-sided adhesive tape, and a step of forming a conductive double-sided adhesive tape. It can be manufactured using a manufacturing method including a step of laminating the second main surface of the layer and one pressure-sensitive adhesive layer of the conductive double-sided pressure-sensitive adhesive tape.

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

The present disclosure is not limited to the above embodiments. The above embodiment is an example, and any device that has substantially the same configuration as the technical idea described in the claims of the present disclosure and achieves the same effect is the present invention. It is included in the technical scope of the disclosure.

Examples and comparative examples will be specifically described below.

(Polyurethane resin solution A)
Number obtained by reacting an acid component of adipic acid/terephthalic acid = 50/50 and 3-methyl-1,5 pentanediol in a four-neck flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube. 192.9 parts by mass of a polyester polyol having an average molecular weight (hereinafter referred to as Mn) of 2,000, 15.8 parts by mass of 1,4-butanediol, and 77.9 parts by mass of isophorone diisocyanate were charged and placed under a nitrogen stream. at 90° C. for 5 hours. Next, 11.0 parts by mass of isophoronediamine, 2.4 parts by mass of di-n-butylamine, and 700 parts by mass of methyl ethyl ketone are further added and reacted at 50° C. for 4 hours under stirring to obtain a resin. A polyurethane resin solution A having a solid content concentration of 30.0% by mass, a Gardner viscosity of U (25° C.), an amine value of 0, and a weight average molecular weight of 30,000 was obtained.

(black ink)
55 parts by mass (N.V. 30%) of the prepared polyurethane resin solution A and (1-{4-[(4,5,6,7-tetrachloro-3-oxoisoindoline-1 -ylidene)amino]phenylazo}-2-hydroxy-N-(4'-methoxy-2'-methylphenyl)-11H-benzo[a]carbazole-3-carboxamide) (manufactured by Dainichiseika Co., Ltd. near-infrared reflection 10 parts by mass of pigment "Chromo Fine Black A1103" (CAS number: 103621-96-1)) and inorganic filler (Fuji Silysia Ltd. "Silophobic 704" silane coupling treatment: average particle size 3 by Coulter counter method .5 μm), 5 parts by mass of spherical silicone resin beads (“Tospearl 2000B” manufactured by Momentive Performance Materials Co., Ltd.: average particle size 6 μm by the Coulter counter method), 2 parts by mass, and polyethylene fine powder wax (manufactured by BASF) 2 parts by mass of "Luwax AF29 Micropowder", 1 part by mass of a dispersant ("Solspers 24000 GR" manufactured by Lubrizol), 13 parts by mass of methyl ethyl ketone, 9 parts by mass of ethyl acetate, and 5 parts by mass of isopropyl alcohol. and 5 parts by mass of propylene glycol monomethyl ether are added, respectively, and wet-dispersed in a sand mill for about 1 hour to obtain a mixture.To this mixture, hexamethylene diisocyanate type isocyanurate (manufactured by Sumika Bayer Urethane Co., Ltd. A black ink was prepared by adding 5 parts by mass of a polyisocyanate curing agent "Sumidur N3300") and 40 parts by mass of a diluent ("NH-NT DC solvent" manufactured by DIC Graphics).

(Black ink coated film A (insulating portion A))
A polyester film (F53 Lumirror #2.0 manufactured by Toray Industries, Inc., thickness: 2.0 μm) was used as an insulating resin layer, and black ink was applied to one surface of the polyester film so that the thickness after drying was 1.0 μm. and dried at 100° C. for 1 minute to obtain a black ink layer.

Next, on the black ink layer, OS-M suede OP varnish manufactured by Dainichiseika Co., Ltd. is used as a matting agent, and gravure coating is applied so that the thickness of the matte ink layer (matte layer) is 0.5 μm. , 100°C for 1 minute and aged at 40°C for 2 days. As a result, a black ink coated film A (insulating portion A) is obtained in which a black ink layer is formed on one side of the polyester film (insulating resin layer) and a matte ink layer (matte layer) is formed on the black ink layer. Ta. The total thickness of the black ink coated film A was 3.5 µm. The thickness of the black ink layer was measured by cutting the black ink coated film A with a razor and enlarging the cross section by 2500 times with a microscope.

(Black ink coated film B (insulating portion B))
Polyimide film (“Kapton 20EN” manufactured by Toray DuPont, thickness: 5.0 μm) instead of polyester film (Toray “F53 Lumirror #2.0”, thickness: 2.0 μm) is used as an insulating resin layer. A black ink layer is formed on one side of the polyimide film (insulating resin layer), and a matte ink layer (matte layer) is formed on the black ink layer in the same manner as the black ink-coated film A except that it is used as A black ink-coated film B (insulating portion B) was obtained. The total thickness of the black ink coated film B was 6.5 µm.

(Preparation of transparent adhesive A)
97.98 parts by weight of n-butyl acrylate, 2 parts by weight of acrylic acid, and 0.02 parts by weight of 4-hydroxybutyl acrylate were added to a reaction vessel equipped with a condenser, stirrer, thermometer and dropping funnel. , 0.2 parts by mass of azobisisobutyronitrile as a polymerization initiator was added to an ethyl acetate solution, and solution polymerization was performed in the solution at 80 ° C. for 8 hours to obtain an acrylic polymer having a weight average molecular weight of 900,000. A system polymer A was obtained.

Next, to 100 parts by mass of acrylic polymer A, 5 parts by mass of polymerized rosin ester (manufactured by Arakawa Chemical Co., Ltd., trade name "D-135") and disproportionated rosin ester (manufactured by Arakawa Chemical Co., Ltd., trade name "KE-100") ) and 25 parts by mass of a petroleum resin (trade name “FTR6100”) were added, and ethyl acetate was further added to prepare an acrylic pressure-sensitive adhesive solution A having a solid content of 40% by mass.

Add 0.8 parts by mass of an isocyanate cross-linking agent (trade name “NC40” manufactured by DIC Corporation, solid content 40% by mass) to 100 parts by mass of acrylic pressure-sensitive adhesive solution A (solid content 40% by mass) to make it uniform. A transparent adhesive A was prepared by stirring and mixing as follows. The transparent pressure-sensitive adhesive A had a gel fraction of 20% by mass and a storage elastic modulus of 9×10 ⁴ Pa at 25°C.

(Preparation of black adhesive B)
To 100 parts by mass of the acrylic pressure-sensitive adhesive solution A (solid content 40% by mass), a black coloring agent (DIC Corporation "DICTON Black AR8555", carbon black content: 45% (solid content ratio), resin solid content concentration 49 %) is added and mixed uniformly with a stirrer, and 1.2 parts by mass of an isocyanate-based cross-linking agent (trade name “NC40” manufactured by DIC) is added and mixed by stirring so as to be uniform. Thus, a black adhesive B was prepared. The black adhesive B had a gel fraction of 20% by mass and a storage elastic modulus of 9×10 ⁴ Pa at 25°C.

(Preparation of black adhesive C)
15 parts by mass of a polyester adhesive (DIC Graphics dry lamination adhesive "Dick Dry LX-703VL", solid content 62%) and an isocyanate curing agent (DIC Graphics Co., Ltd. Curing agent "KR-90 ”, solid content 90%) and 1 part by mass of a black coloring agent (“DICTON Black AR8555” manufactured by DIC, carbon black content: 45% (solid content ratio), resin solid content concentration 49%). Black Adhesive C was prepared by adding and stirring to mix evenly. The black pressure-sensitive adhesive C had a gel fraction of 90% by mass and a storage elastic modulus at 25° C. of 2×10 ⁵ Pa.

The gel fraction of each pressure-sensitive adhesive is obtained by immersing each pressure-sensitive adhesive in toluene, measuring the weight of the remaining insoluble matter after drying for 24 hours, and expressing it as a percentage of the original weight.
Gel fraction (% by mass) = [(mass of adhesive after immersion in toluene)/(mass of adhesive before immersion in toluene)] x 100

(Preparation of conductive adhesive A)
75.0 parts by weight of n-butyl acrylate, 19.0 parts by weight of 2-ethylhexyl acrylate, and 3.9 parts by weight of vinyl acetate were added to a reaction vessel equipped with a condenser, stirrer, thermometer and dropping funnel. And, 2.0 parts by mass of acrylic acid, 0.1 parts by mass of 2-hydroxyethyl acrylate, 0.1 parts by mass of 2,2'-azobisisobutylnitrile as a polymerization initiator, and 100 parts by mass of ethyl acetate. After dissolving in parts by mass and purging with nitrogen, polymerization was performed at 80° C. for 12 hours to obtain an acrylic polymer B having a weight average molecular weight of 600,000.

Next, to 100 parts by mass of the solid content of acrylic polymer B, 10 parts by mass of polymerized rosin pentaerythritol ester ("Pencel D-135" manufactured by Arakawa Chemical Industries, softening point 135 ° C.) and disproportionated rosin glycerin 10 parts by mass of ester (“Super Ester A-100” manufactured by Arakawa Chemical Industries, Ltd., softening point 100 ° C.) is blended, and ethyl acetate is used to adjust the solid content concentration of the acrylic polymer to 40% by mass. An acrylic pressure-sensitive adhesive solution B was obtained.

100 parts by mass of acrylic adhesive solution B (solid content concentration 40% by mass) and 0.4 mass of nickel powder (“NI255T” beaded conductive particles manufactured by Fukuda Metal Foil & Powder Co., Ltd., d50: 26.0 μm) part, 2 parts by mass of an isocyanate cross-linking agent (DIC Corporation "Barnock NC40", solid content 40% by mass) as a cross-linking agent, and 70 parts by mass of ethyl acetate as a dilution solvent for 10 minutes using a dispersion stirrer. Conductive Adhesive A was prepared by mixing.

(Preparation of insulating adhesive A)
100 parts by mass of acrylic adhesive solution B (solid content concentration 40% by mass), and 2 parts by mass of isocyanate cross-linking agent (DIC Corporation "Barnock NC40", solid content 40% by mass) as a cross-linking agent. An insulating adhesive A was prepared by mixing 70 parts by mass of ethyl acetate as a solvent for 10 minutes using a dispersion stirrer.

(Manufacture of conductive adhesive tape A)
Conductive adhesive A is coated on release film A (trade name “PET38×1K0” manufactured by Nippa) so that the thickness after drying is 5 μm, and dried at 100° C. for 2 minutes to form conductive adhesive layer A. Then, a conductive adhesive tape A was obtained.

(Manufacture of insulating adhesive tape A)
Release film A (manufactured by Nippa Co., Ltd., trade name “PET38×1K0”) is coated with insulating adhesive A so that the thickness after drying is 5 μm, and dried at 100 ° C. for 2 minutes to form insulating adhesive layer A. Then, an insulating adhesive tape A was obtained.

(Preparation of adhesive C)
60 parts by weight of n-butyl acrylate, 35.95 parts by weight of 2-ethylhexyl acrylate, and 4.0 parts by weight of acrylic acid were placed in a reaction vessel equipped with a stirrer, reflux condenser, thermometer, dropping funnel and nitrogen gas inlet. 0 parts by mass, 0.05 parts by mass of 4-hydroxybutyl acrylate, 0.2 parts by mass of 2,2'-azobisisobutylnitrile as a polymerization initiator, 50 parts by mass of ethyl acetate and 20 parts by mass of n-hexane and polymerized at 70° C. for 8 hours to obtain an acrylic copolymer C having a weight average molecular weight of 700,000.

Next, with respect to 100 parts by mass of the solid content of the acrylic copolymer C, 20 parts by mass of a polymerized rosin ester resin ("D-125" manufactured by Arakawa Chemical Industries, Ltd.) and a disproportionated rosin ester (Arakawa Chemical Industries, Ltd. "A100" manufactured by Co., Ltd.) was added, and the solid content concentration was adjusted to 45% by mass using ethyl acetate to obtain an acrylic pressure-sensitive adhesive solution C.

Next, 100 parts by mass of acrylic adhesive solution C (45 parts by mass of solid content) and an isocyanate cross-linking agent (“Barnock NC-40” manufactured by DIC Corporation, 40% by mass of solid content, ethyl acetate solution) were added to 1.7 mass parts. and mixed for 10 minutes using a dispersion stirrer to obtain an acrylic pressure-sensitive adhesive C.

(Example 1)
On the polyester film surface of the black ink coated film A, the black adhesive B is gravure-coated so that the thickness after drying is 1.5 μm, dried at 70 ° C. for 2 minutes to form a black adhesive layer B, and then having a thickness of 30 μm. (“CF-PLFA-30” manufactured by Fukuda Metal Foil & Powder Co., Ltd.) on the poppy surface of the electrodeposited copper foil, and further aged at 40° C. for 2 days to obtain a conductive laminate. Rz and Ra of the glossy surface of the electrolytic copper foil were 0.72 μm and 0.11 μm, respectively. The poppy surface of the electrolytic copper foil had Rz of 1.4 μm and Ra of 0.23 μm.

(Example 2)
A conductive laminate was produced in the same manner as in Example 1 except that a 33 μm thick electrolytic copper foil (“CF-PLFA-33” manufactured by Fukuda Metal Foil & Powder Co., Ltd.) was used instead of the 30 μm thick electrolytic copper foil. Obtained. Rz and Ra of the glossy surface of the electrolytic copper foil were 0.78 μm and 0.12 μm, respectively. The poppy surface of the electrolytic copper foil had Rz of 1.5 μm and Ra of 0.25 μm.

(Example 3)
A conductive laminate was obtained in the same manner as in Example 1, except that the black ink-coated film B was used instead of the black ink-coated film A.

(Example 4)
A conductive laminate was obtained in the same manner as in Example 1, except that a black adhesive layer C having a thickness of 1.5 μm after drying was formed using a black adhesive layer C instead of the black adhesive layer B.

(Example 5)
Same as Example 1 except that a 30 μm thick rolled copper foil (“TCu-O-30” manufactured by Fukuda Metal Foil & Powder) was used instead of the 30 μm thick electrolytic copper foil “CF-PLFA-30”. to obtain a conductive laminate. The surface roughness of the electrolytic copper foil was 0.6 μm in Rz and 0.1 μm in Ra.

(Example 6)
The conductive pressure-sensitive adhesive layer A of the conductive pressure-sensitive adhesive tape A was adhered to the electrolytic copper foil surface of the conductive laminate of Example 1, and further aged at 40° C. for 2 days to obtain a conductive laminated tape. The peeling film A of the conductive adhesive tape A is peeled off during the evaluation, and the peeling film A is not included in the total thickness of the conductive laminated tape.

(Example 7)
The conductive adhesive tape A and the insulating adhesive tape A were alternately laminated with a width of 5 mm to the electrolytic copper foil surface of the conductive laminate of Example 1, and further aged at 40 ° C. for 2 days to form a conductive laminated tape. got The conductive adhesive tape A and the release film A of the insulating adhesive tape A are removed during the evaluation, and the release film A is not included in the total thickness of the conductive laminated tape.

(Comparative example 1)
Acrylic pressure-sensitive adhesive C is applied onto a release liner (“PET38×1A3” manufactured by Nippa Co., Ltd.) using a roll coater so that the thickness after drying is 50 μm, and placed in a dryer at 80° C. for 3 minutes. It was dried to form a transparent pressure-sensitive adhesive layer C, which was cured in an environment of 40°C for 48 hours.

Next, the pressure-sensitive adhesive layer was attached to one surface of an electrolytic copper foil substrate having a thickness of 35 μm. Next, an adhesive tape with a total thickness of 10 μm (“IL-10BMF” manufactured by DIC Corporation, black colored layer (thickness: 1.5 μm) / polyethylene terephthalate film (thickness: 4.5 μm) / transparent adhesive layer (thickness: 4 μm) (“/” indicates a lamination interface)) was laminated to the other surface of the electrolytic copper foil substrate to prepare a conductive laminated tape.

(Comparative example 2)
Polyester resin (Unitika Ltd.) using an isocyanate curing agent (Japan Polyurethane Industry Co., Ltd. "Coronate L") on one side of a 5 μm thick PET film (manufactured by Teijin DuPont Films Co., Ltd. "Mylar") "UE3220" manufactured by Nippon Foil Co., Ltd.) was applied at 3 g/m ² (calculated as a dry coating amount), and a 7 μm-thick soft aluminum foil (Nippon Foil Co., Ltd. 1030N-0 material) was laminated. Similarly, a 7 μm-thick soft aluminum foil (1030N-0 material, Nippon Foil Co., Ltd.) was laminated on the other surface of the PET film to prepare a base substrate.

An acrylic adhesive containing 10% by mass of carbon black is applied to a release PET film so that the dry thickness is 5 μm and dried to form a conductive black adhesive layer. The previously prepared base substrate was laminated on the adhesive layer.

Subsequently, an insulating black ink (an ink in which aniline black is dispersed in a polyester resin) is applied onto the base substrate and dried to a dry thickness of 3 μm to form a black ink layer, thereby making it conductive. A laminated tape was obtained.

(Comparative Example 3)
A conductive laminate was obtained in the same manner as in Example 1 except that the transparent adhesive A was used instead of the black adhesive B to form a transparent adhesive layer having a thickness of 1.5 μm after drying.

(Comparative Example 4)
Black ink A was gravure-coated to a thickness of 4.5 μm on the shiny side of the electrolytic copper foil (“CF-T8G-DK-35” manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd.) with a thickness of 35 μm, and dried at 100 ° C. for 1 minute. to form a black ink layer A. Next, OS-M suede OP varnish manufactured by Dainichiseika Co., Ltd. was used on the black ink layer to form a matte ink layer (mat layer) with a thickness of 0.5 μm. and dried for 1 minute at 100° C. As a result, a conductive laminate having a layer structure of matte ink layer (matted layer)/black ink layer/electrolytic copper foil (/ represents a lamination interface) The glossy surface of the electrolytic copper foil had Rz of 1.4 μm and Ra of 0.18 μm, and the poppy surface of the electrolytic copper foil had Rz of 10.2 μm and Ra of 1.6 μm. .

The ten-point average surface roughness Rz and the arithmetic average roughness Ra of the conductive layer used in Examples and Comparative Examples are each in accordance with JIS B0601, using Tokyo Seimitsu Co., Ltd. HANDYSURF +, the surface of the conductive layer Surface measurement was performed on three arbitrary points, and the average value of the three points obtained by the measurement was taken.

[evaluation]
The performances of the conductive laminates of Examples and Comparative Examples and the conductive laminated tapes of Examples and Comparative Examples were evaluated by the following measurement methods.

(thickness)
Using a thickness gauge (DIGIMICRO MFC-101 manufactured by NIKON), the conductive laminates of Examples 1-5 and Comparative Examples 3-4, and the conductive laminated tapes of Examples 6-7 and Comparative Examples 1-2 The total thickness of the conductive laminate portion was measured. Further, for the conductive laminated tapes of Examples 6 and 7 and Comparative Examples 1 and 2, the total thickness including the adhesive layer provided on the second main surface of the conductive layer was also measured.

(Thinness)
The thicknesses of the conductive laminate portions of the conductive laminates of Examples 1 to 5 and Comparative Examples 3 and 4, and the conductive laminate tapes of Examples 6 to 7 and Comparative Examples 1 and 2 were evaluated according to the following evaluation criteria. .
○: 40 μm or less ×: greater than 40 μm

(L ^* , a ^* , b ^* )
Using a spectrophotometer (KONICA MINOLTA SPECTROPHOTOMETER CM-5), according to the measurement standard JIS Z 8722 with a C spectrum of 2 °, the conductive laminates of Examples 1 to 5 and Comparative Examples 3 to 4, and the implementation CIE color values (L ^* , a ^* , b ^* ) were measured from the surface of the insulating portion side of the conductive laminated tapes of Examples 6 to 7 and Comparative Examples 1 and 2, respectively.

(60° gross value)
According to JIS Z 8741, at a setting angle of 60 °, using MINOLTA Multi-Gloss 268 manufactured by KONICA MINOLTA, Examples 1 to 5 and Comparative Examples 3 to 4 The conductive laminates, and Examples 6 to 7 and Comparative Examples The gloss value (glossiness Gu) was measured from the insulating portion side surface of each of the conductive laminated tapes Nos. 1 and 2.

(Hiding rate of black pressure-sensitive adhesive layer)
The hiding rate of the black pressure-sensitive adhesive layer in the conductive laminates of Examples 1-5 and Comparative Examples 3-4 and the conductive laminated tapes of Examples 6-7 and Comparative Examples 1-2 was measured by the following method. One side of a release film (manufactured by Nippa Co., Ltd., trade name “PET38×1K0”) was coated with the black pressure-sensitive adhesives B and C used in Examples so that the thickness after drying was 1.5 μm. It was dried for a minute to form a black pressure-sensitive adhesive layer to obtain a black pressure-sensitive adhesive tape. Next, a black adhesive tape is attached to the white side and the black side of the hiding rate test paper (manufactured by Nippon Test Panel Kogyo Co., Ltd.), the release film is peeled off, and the color is measured according to JIS-Z-8722. , the Y value indicating the brightness among the tristimulus values of the black pressure-sensitive adhesive layer attached to the white surface and the black surface was measured. Using a colorimetric gloss meter "CM-3500d" (manufactured by Minolta Co., Ltd.), standard light C was measured in a 2-degree field of view, and the measured Y value was applied to the following formula to measure the hiding rate.
Hiding rate (%) = (Y value of black pressure-sensitive adhesive layer attached to black surface/Y value of black pressure-sensitive adhesive layer attached to white surface) x 100%

(Insulation)
Using a resistivity meter (Lorestar MCP-T600 manufactured by Mitsubishi Chemical Corporation), the surface of the insulating portion side of the conductive laminates of Examples 1 to 5 and Comparative Examples 3 and 4 (the surface opposite to the conductive layer side surface ), and the insulating part side surface of the conductive laminated tapes of Examples 6 to 7 and Comparative Examples 1 and 2 (the surface opposite to the conductive adhesive layer side surface). The surface resistivity of the surface was measured. Evaluation was made according to the following evaluation criteria.
◯: Surface resistivity (overload) of 9.9×10 ⁷ Ω/□ or more
×: Surface resistivity less than 9.9×10 ⁷ Ω/□

(Conductivity)
Using a resistivity meter (Mitsubishi Chemical Lorestar MCP-T600), a four-terminal probe was applied to the conductive layer side surface of the conductive laminates of Examples 1 to 5 and Comparative Examples 3 to 4, and the conductive layer side surface was measured. Further, in the conductive laminated tapes of Examples 6 and 7 and Comparative Examples 1 and 2, the surface resistivity was measured on the conductive adhesive layer side surface. Evaluation was made according to the following evaluation criteria.
◎: 0.6mΩ/□ or less 〇: Exceeds 0.6mΩ/□, 10mΩ/□ or less ×: Exceeds 10mΩ/□

(Electromagnetic wave shielding)
From the conductive laminates of Examples 1-5 and Comparative Examples 3-4, and the conductive laminated tapes of Examples 6-7 and Comparative Examples 1-2, test pieces 25 each having a width of 20 mm and a length of 40 mm were cut out, A sample was prepared by placing a 0.5 mm×20 cm×20 cm aluminum plate 27 having a slit 26 of 5 mm×20 mm in the center so as to block the slit (FIG. 5). A test piece 25 of the conductive laminate was placed on an aluminum plate, and a test piece 25 of the conductive laminated tape was attached to an aluminum plate 27 . Next, the aforementioned sample was installed in a magnetic field shield box 28 (manufactured by Shield Room Co., Ltd.) conforming to the Kansai Electronic Industry Development Center (KEC) law. A spectrum analyzer 29 (MS2661C manufactured by Anritsu Co., Ltd.) was installed in a shield box, and shielding characteristics against electromagnetic waves with a frequency of 3 GHz were evaluated according to the following evaluation criteria (Fig. 6).
◎: 45 db or more ○: 40 db or more and less than 45 db ×: less than 40 db

(Adhesiveness)
A 25 μm-thick PET film (Lumirror S10#25 manufactured by Toray Industries, Inc.) was attached to the conductive adhesive A of the conductive adhesive tape A to form a sheet having a configuration of release film A/conductive adhesive layer A/PET film. Created. Next, this sheet is cut into 20 mm width × 100 mm length, the release film A is peeled off, and the conductive layer side (copper foil) of the conductive laminates of Examples 1 to 5 and Comparative Examples 3 to 4 The conductive pressure-sensitive adhesive layer A was pasted together, and after one reciprocating pressure with a 2 kg roller, it was allowed to stand at 23° C. and 50% RH for 1 hour, and the adhesive force was measured when peeled off in the direction of 180° at a speed of 300 mm / min. . Evaluation was made according to the following evaluation criteria.
◎: 3 N / 20 mm or more ○: 1 N / 20 mm or more and less than 3 N / 20 mm ×: less than 1 N / 20 mm

(Adhesive strength of conductive laminate adhesive tape)
Samples obtained by bonding the conductive adhesive tape A to the conductive layer surface of the conductive laminates of Examples 1 to 5 and Comparative Examples 3 and 4 were left at 23° C. 50% RH for 1 day, and then cut into pieces of 25 mm width×100 mm length. , was applied to a SUS plate, pressed once with a 2 kg roller, allowed to stand at 23° C. and 50% RH for 1 hour, and then peeled off in a 180° direction at a rate of 300 mm/min to measure the adhesive strength. In addition, the conductive laminate tapes of Examples 6 and 7 were cut into 25 mm width x 100 mm length as they were, attached to a SUS plate, pressed once with a 2 kg roller back and forth, and left at 23°C and 50% RH for 1 hour. Then, the adhesive force was measured when the film was peeled off at a speed of 300 mm/min in the direction of 180°. Evaluation was made according to the following evaluation criteria.
◎: 8 N / 25 mm or more ○: 4 N / 25 mm or more and less than 8 N / 25 mm ×: less than 4 N / 25 mm

The results are shown in Tables 1-4.

From Tables 1 to 4, the conductive laminates of Examples 1 to 5 and the conductive laminated tapes of Examples 6 to 7 have an insulating portion having a black ink layer and an insulating resin layer, a black adhesive layer, By having a layer structure in which a metal foil is laminated in this order as a conductive layer, it is possible to exhibit high conductivity, high electromagnetic wave shielding properties, and high surface insulation properties while the total thickness is small and thin. By having the above laminated structure, the lightness L ^* , the chromaticities a ^* and b ^* of the insulating portion side surface of the conductive laminate can be set within predetermined ranges, respectively, and the surface blackness, particularly the black design property can be improved. It was shown that it is possible to increase

DESCRIPTION OF SYMBOLS 1... Conductive layer (metal foil), 2... Black adhesive layer, 3... Insulating part, 4... Insulating resin layer, 5... Black ink layer, 10... Conductive laminate, 11... Conductive adhesive layer, 12 ... Insulating adhesive layer, 20 ... Conductive laminated tape

Claims (12)

A conductive laminate,
a conductive layer having first and second major surfaces facing each other;
a black adhesive layer provided on the first main surface of the conductive layer;
an insulating portion provided on the black adhesive layer;
has
The conductive layer is a metal foil,
The insulating part has an insulating resin layer and a black ink layer,
The lightness L ^* defined by the CIE L ^* a ^* b ^* color system of the surface of the conductive laminate located on the first main surface side of the conductive layer is 20 or more and 27 or less, and the chromaticity A conductive laminate having a ^* of −2 or more and 2 or less and a chromaticity b ^* of −2 or more and 2 or less. 2. The conductive laminate according to claim 1, wherein the insulating resin layer and the black ink layer are laminated in this order from the black adhesive layer side. 3. The conductive laminate according to claim 1, wherein the surface of the conductive laminate located on the first main surface side of the conductive layer has a 60[deg.] gloss value of 1 or more and 5 or less. 4. The conductive laminate according to any one of claims 1 to 3, wherein said metal foil is copper foil. 5. The conductive laminate according to claim 4, wherein said copper foil is an electrolytic copper foil. The conductive laminate according to any one of claims 1 to 5, wherein the conductive layer has a ten-point average surface roughness Rz of 2.0 µm or less. The conductive laminate according to any one of claims 1 to 6, wherein the black ink layer has a thickness of 1 µm or more and 3 µm or less. The conductive laminate according to any one of claims 1 to 7, wherein the insulating resin layer has a thickness of 1 µm or more and 5 µm or less. The conductive laminate according to any one of claims 1 to 8, wherein the black pressure-sensitive adhesive layer has a hiding rate of 20% or more. The electroconductive laminate according to any one of claims 1 to 8, wherein the electroconductive laminate has a total thickness of 20 µm or more and 40 µm or less. Having the conductive laminate according to any one of claims 1 to 10 and a conductive pressure-sensitive adhesive layer,
A conductive laminate tape, wherein the conductive pressure-sensitive adhesive layer is provided on the second main surface of the conductive layer constituting the conductive laminate. The conductive adhesive layer is provided in a pattern on the second main surface of the conductive layer,
12. The conductive laminated tape according to claim 11, wherein an insulating pressure-sensitive adhesive layer is disposed on the second major surface in areas where the conductive pressure-sensitive adhesive layer is not disposed.

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