KR101862121B1 - Electromagnetic wave shielding sheet, printed wiring board and electronic devices - Google Patents

Abstract

An object of the present invention is to provide an electromagnetic wave shielding sheet, a printed wiring board and an electronic apparatus having an insulating layer having excellent print visibility.
An electromagnetic wave shielding sheet comprising an insulating layer and a conductive adhesive layer and containing a black coloring agent satisfying any one of the following (1) to (3):
(1) The insulating layer contains a black coloring agent and has an 85 ° gloss of 15 to 50, an L * value of 20 to 30 in the L * a * b * coloring system, and an average primary particle diameter and content To a specific range.
(2) The insulating layer contains a black coloring agent, and the surface of the insulating layer has a contact angle with water of 60 to 110 °.
(3) The insulating layer is formed of a transparent resin composition, the surface of the insulating layer has a contact angle with water of 60 to 110 °, and the black colorant is contained in the black layer.

Description

ELECTROMAGNETIC WAVE SHIELDING SHEET, PRINTED WIRING BOARD AND ELECTRONIC DEVICES TECHNICAL FIELD [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shielding sheet for shielding electromagnetic waves generated from electronic parts such as printed wiring boards. The present invention also relates to a printed wiring board and an electronic apparatus.

Flexible printed wiring boards (hereinafter referred to as FPCs) have flexibility. Therefore, in order to meet demands for higher performance and miniaturization such as OA apparatuses, communication apparatuses, and cellular phones in recent years, an electronic circuit is inserted into a case made of a narrow and complicated structure Has been used to put a lot. As downsizing and high frequency of such electronic circuits are being developed, countermeasures against unnecessary electromagnetic noise generated therefrom become more important. Conventionally, an electromagnetic wave shielding sheet for shielding electromagnetic noise generated in an electronic circuit is stacked on an FPC. This electromagnetic shielding sheet is required to be thin and excellent in bending resistance so as not to hinder the flexing resistance of the entire FPC in addition to the electromagnetic wave shielding property. Therefore, it is widely known that the electromagnetic shielding sheet is provided with a conductive layer on a thin base film.

For example, Patent Document 1 discloses an electromagnetic wave shielding sheet in which an adhesive layer, a cover film, a metal thin film layer, and a conductive adhesive layer are sequentially laminated. Patent Document 2 discloses an electromagnetic wave shielding sheet in which a base film, a metal thin film layer, and a conductive adhesive layer are sequentially laminated. Patent Document 3 discloses an electromagnetic wave shielding sheet in which a cover film, a metal thin film layer, and a conductive adhesive layer are sequentially laminated. Patent Document 4 discloses an electromagnetic wave shielding coverlay film in which an insulating resin layer containing a colorant, a conductive layer composed of a metal thin film, and a conductive adhesive layer are sequentially laminated.

Normally, an electromagnetic wave shielding sheet is attached to a large-sized wiring board and then cut into a predetermined shape to produce a printed wiring board having a size that can be mounted on electronic equipment. At this time, in order for the manufacturer to grasp the production lot, the product name and lot number are often printed in white on the insulating layer of the electromagnetic shielding sheet on the printed wiring board by screen printing or the like. Since the printing area is small, the character size is usually small. .

Japanese Patent Application Laid-Open No. 2003-298285 Japanese Patent Application Laid-Open No. 2004-273577 Japanese Patent Application Laid-Open No. 2004-95566 Japanese Patent Application Laid-Open No. 2014-078574

The FPC prints the product number and lot number on the surface of the laminated electromagnetic wave shielding sheet. In the conventional electromagnetic shielding sheet, the operator who installs the FPC on the electronic equipment has poor visibility of the print and there is a problem in the print quality.

An object of the present invention is to provide an electromagnetic wave shielding sheet having an insulating layer excellent in print visibility, which has been made in view of the above problems.

The electromagnetic shielding sheet of the present invention is an electromagnetic shielding sheet containing a black coloring agent,

At least an insulating layer, and a conductive adhesive layer,

An electromagnetic wave shielding sheet which satisfies any one of the following (1) to (3):

(1) The insulating layer is formed of a black resin composition containing a thermosetting resin, a curing agent and the black coloring agent, and has an 85 ° gloss of 15 to 50 and an L * value in an L * a * b * Is 20 to 30,

The black coloring agent has an average primary particle size of 20 to 100 nm and a content of the black coloring agent in an amount of 12.2 to 40 wt% in 100 wt% of the insulating layer.

(2) The insulating layer is formed of a black resin composition containing a thermosetting resin, a curing agent and the black coloring agent, and the surface of the insulating layer has a contact angle with water of 60 to 110 °.

(3) The insulating layer is formed of a transparent resin composition containing a transparent resin, the surface of the insulating layer has a contact angle with water of 60 to 110 °, and the black coloring agent is a conductive adhesive layer In the black layer.

The printed wiring board of the present invention comprises the above-mentioned electromagnetic wave shielding sheet, a cover coat layer, a signal wiring and a wiring board having an insulating base material.

An electronic apparatus of the present invention includes the printed wiring board.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an electromagnetic wave shielding sheet having an insulating layer having excellent print visibility.

Fig. 1 (a) is a schematic cross-sectional view showing an example of an electromagnetic wave shielding sheet according to the first embodiment, and Fig. 1 (b) is a schematic cross-sectional view showing an example of an electromagnetic wave shielding sheet according to a modification.
2 is a schematic cross-sectional view showing an example of a printed wiring board according to the first embodiment.
Fig. 3 (a) is a schematic sectional view showing an example of an electromagnetic wave shielding sheet according to a third embodiment, and Fig. 3 (b) is a schematic cross-sectional view showing an example of an electromagnetic wave shielding sheet according to a modification.

Hereinafter, an example of an embodiment to which the present invention is applied will be described. In addition, numerical values specified in this specification indicate values obtained by the method described in the following embodiments. The numerical values " A to B " specified in this specification indicate ranges that are larger than numerical values A and A and satisfy values smaller than numerical values B and B. The various components in the present specification may be used singly or in combination of two or more species, unless specifically indicated otherwise. In the drawings, the same element members are denoted by the same reference numerals in the other embodiments for convenience of explanation. The term "(meth) acryl" means acryl and methacryl, and "(meth) acrylate" means acrylate and methacrylate.

[First Embodiment]

The electromagnetic wave shielding sheet according to the first embodiment contains a black coloring agent and has at least an insulating layer and a conductive adhesive layer. The insulating layer is formed of a black resin composition containing a thermosetting resin (A1), a curing agent (A2) and the black colorant, [1b] an 85 ° gloss of 15 to 50, and [1c ] L * a * b * The L * value in the colorimetric system satisfies the range of 20 to 30. The black coloring agent contained in the insulating layer contains [1d] an average primary particle diameter of 20 to 100 nm and 12.2 to 40 mass% of 100 mass% of the [1e] insulating layer.

Fig. 1 (a) shows a cross-sectional view of an example of an electromagnetic wave shielding sheet according to the first embodiment. The electromagnetic wave shielding sheet 4 is composed of a laminate of the insulating layer 1 and the conductive adhesive layer 2 as shown in the drawing. Hereinafter, each layer will be described in detail.

<Insulating Layer> The insulating layer according to the first embodiment satisfies the above-mentioned [1a] to [1c] and [1e], and the black coloring agent contained in the insulating layer satisfies the above [1d].

[1a]: Black resin composition and coating film (coating film)

The thermosetting resin (A1) is a resin having a plurality of functional groups usable for crosslinking reaction upon heating.

Examples of the functional group include a hydroxyl group, a phenolic hydroxyl group, a carboxyl group, an amino group, an epoxy group, an oxetanyl group, an oxazoline group, an oxazine group, an aziridine group, a thiol group, an isocyanate group, a blocked isocyanate group and a cilanol group.

The thermosetting resin (A1) having the above-mentioned functional groups may be selected from, for example, acrylic resin, maleic acid resin, polybutadiene resin, polyester resin, condensation type polyester resin, addition type polyester resin, melamine resin, polyurethane resin, An epoxy resin, an epoxy resin, an oxetane resin, a phenoxy resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a phenol resin, an alkyd resin, an amino resin, a polylactic acid resin, an oxazoline resin, , Silicone resin, and fluorine resin. Among them, a polyurethane resin, a polyurethane-urea resin, an epoxy resin, an addition type polyester resin, a polyimide resin, a polyamide resin and a polyamide-imide resin are preferable from the viewpoints of surface resistance and abrasion resistance (ink resistance).

In the present invention, a thermoplastic resin (A3) can be used in combination with the thermosetting resin (A1).

Examples of the thermoplastic resin (A3) include polyolefin resins, vinyl resins, styrene / acrylic resins, diene resins, terpene resins, petroleum resins, cellulosic resins, polyamide resins, polyurethane resins, poly An ester resin, a polycarbonate resin, a polyimide resin, and a fluorine resin.

As the polyolefin-based resin, homopolymers or copolymers such as ethylene, propylene, and alpha -olefin compounds are preferable. Specifically, for example, a polyethylene propylene rubber, an olefin thermoplastic elastomer, an -olefin polymer, and the like can be mentioned.

As the vinyl resin, a polymer obtained by polymerization of a vinyl ester such as vinyl acetate and a copolymer of a vinyl ester and an olefin compound such as ethylene are preferable. Specific examples thereof include ethylene-vinyl acetate copolymer, partially saponified polyvinyl alcohol, and the like.

The styrene / acrylic resin is preferably a homopolymer or copolymer composed of styrene, (meth) acrylonitrile, acrylamides, (meth) acrylic acid esters, maleimides and the like. Specific examples thereof include syndiotactic polystyrene, polyacrylonitrile, acrylic copolymer and ethylene-methyl methacrylate copolymer.

As the diene resin, homopolymers or copolymers of conjugated diene compounds such as butadiene and isoprene, and hydrogenated products thereof are preferable. Specific examples thereof include styrene-butadiene rubber and styrene-isoprene block copolymer. The terpene resin is preferably a polymer composed of terpenes or a hydrogenated product thereof. Specifically, for example, aromatic modified terpene resins, terpene phenol resins, and hydrogenated terpene resins can be mentioned.

The petroleum resin is preferably a dicyclopentadiene type petroleum resin or a hydrogenated petroleum resin. The cellulose-based resin is preferably a cellulose acetate butyrate resin. The polycarbonate resin is preferably a bisphenol A polycarbonate. The polyimide-based resin is preferably a thermoplastic polyimide, a polyamide-imide resin, or a polyamic acid-type polyimide resin.

The curing agent (A2) has a plurality of functional groups capable of reacting with the functional group in the thermosetting resin (A1). The curing agent (A2) is preferably an epoxy compound, an acid anhydride group-containing compound, an isocyanate compound, an aziridine compound, an amine compound such as dicyandiamide or aromatic diamine, or a phenol compound such as phenol novolac resin.

The curing agent (A2) is preferably contained in an amount of 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and further preferably 3 to 20 parts by mass with respect to 100 parts by mass of the thermosetting resin (A1).

The insulating layer can improve the visibility of printed characters by containing a black coloring agent. The black colorant may be a black pigment. As the black colorant, a mixed colorant including a plurality of pigments such as red, green, blue, yellow, purple, cyan, and magenta may be used. The mixed system colorant can be obtained in black by mixing a plurality of pigments in a dark color. Examples of the black pigment include carbon black, Ketjenblack, carbon nanotube (CNT), perylene black, titanium black, iron black, aniline black, and the like.

The following pigments may be used for the mixed system colorant. "C.I." means a color index (C.I.).

The red pigment and the magenta pigment are, for example, C.I. Pigment Red 7, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 57: 1, 81, 81: , 122, 146, 168, 176, 177, 178, 184, 185, 187, 200, 202, 208, 210, 242, 246, 254, 255, 264, 270, 272 and 279.

The green pigment is, for example, C.I. Pigment Green 1, 2, 4, 7, 8, 10, 13, 14, 15, 17, 18, 19, 26, 36, 45, 48, 50, 51, 54, 55 and 58.

The blue pigment and the cyan pigment are, for example, C.I. Pigment Blue 1, 1: 2, 9, 14, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 19, 25, 27, , 35, 36, 56, 56: 1, 60, 61, 61: 1, 62, 63, 66, 67, 68, 71, 72, 73, 74, 75, 76, 78 and 79.

The yellow pigment is, for example, C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35: , 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101 , 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153 , 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 184, 185, 187 , 188, 193, 194, 198, 199, 213 and 214, and the like.

As the bora pigment, C.I. Pigment Violet 1, 1: 1, 2, 2: 2, 3, 3: 1, 3: 3, 5, 5: 1, 14, 15, 16, 19, 23, 25, 27, 29, 31, 32 , 37, 39, 42, 44, 47, 49, and 50, among others.

The black resin composition may contain pigments and dyes other than the black colorant, and silane coupling agents, antioxidants, tackifying resins, plasticizers, ultraviolet absorbers, antifoaming agents, leveling regulators, fillers, flame retardants and the like as necessary.

The black resin composition can be obtained by mixing and mixing a thermosetting resin (A1), a curing agent (A2), and a black colorant. For stirring, a known stirrer may be used, and a dispenser (dispermat), a homogenizer and the like are preferable.

[1b]: gloss of insulating layer

In the electromagnetic wave shielding sheet of the first embodiment, it is preferable that the surface of the insulating layer has an 85 degree glossiness of 15 to 50. [ Since the gloss is 15 to 50, the light is appropriately scattered on the surface of the insulating layer and the glossiness is moderately suppressed. Thus, characters printed on the insulating layer are easy to see at various angles, thereby improving visibility. When the degree of gloss is 15 to 50, the degree of irregularity of the surface of the insulating layer is appropriately increased and the substantial contact area is reduced, thereby improving the abrasion resistance. When the gloss is 15 or more, peeling between the peelable sheet and the insulating layer becomes easy. When the glossiness is 50 or less, the visibility of the printing is further improved. The method of measuring glossiness will be described later.

In order to impart a predetermined gloss value to the surface of the insulating layer, for example, the following method can be applied. The unevenness is formed by sandblasting or the like in advance on the surface to be peeled off of the peelable sheet. By coating the surface with the black resin composition, the unevenness of the peelable sheet can be transferred to the insulating layer to give an appropriate gloss. As another method, the glossiness can be adjusted by coating the conductive resin layer formed on the peelable sheet with a black resin composition and performing a treatment such as mechanical polishing. Alternatively, an additive such as a matting agent or an inorganic (inorganic) filler may be added to the black resin composition to form irregularities on the surface of the insulating layer without following this method.

[1c]: L * value of the L * a * b * color system of the insulating layer

In the electromagnetic wave shielding sheet of the first embodiment, the L * value in the L * a * b * coloring system of the surface of the insulating layer is preferably 20 to 30. When the L * value is set to 20 to 30, light is absorbed on the surface of the insulating layer, for example, characters printed in white can be more clearly seen.

When the L * value is in the above range, the appearance blackness is not largely changed and the appearance defect is less likely to occur when a part of the surface is worn by contact. In other words, wear resistance can be improved. The L * a * b * value is a coordinate axis indicating the color space. L * denotes a dimension indicating brightness, and a * and b * denotes a complementary color dimension. When the L * value is high, the lacquer is low, while when the L * value is low, the blackness is high and the visibility of the print is good.

In order to obtain the L * value in the above range, for example, the black coloring agent having an average primary particle diameter of 20 to 100 nm is preferably added in an amount of 0.5 to 40 mass% in the insulating layer to be formed, and 1 to 30 mass% Is more preferable. It is needless to say that the means for adjusting the L * value to 20 to 30 is not limited to the black coloring agent. When secondary aggregation occurs in the black colorant, the L * value can be adjusted to 20 to 30 by crushing with a sand mill or the like if necessary. By setting the L * value to 20 or more, the insulation reliability can be further improved. Further, when the L * value is 30 or less, the print visibility is further improved.

[1d]: Average primary particle diameter of the black colorant

The black colorant of the first embodiment should have an average primary particle diameter of 20 to 100 nm. By setting this range, an insulating layer colored with a clear black color free from color bleeding is obtained, and the visibility of characters is further improved. When the average primary particle diameter is 20 nm or more, the viscosity of the black resin composition is easily maintained at a level suitable for the coating. When the average primary particle diameter is 100 nm or less, the blackness of the insulating layer is improved and the print visibility is further improved. When the particle shape of the black colorant has an average aspect ratio (major axis length / minor axis length) of 1.5 or more, the average primary particle diameter is obtained by averaging the major axis length.

The average primary particle diameter of the black coloring agent can be obtained from the average value of about 20 primary particles that can be observed in an image enlarged to about 50,000 to 100,000 times by a transmission electron microscope (TEM).

[1e]: content of black colorant

The black coloring agent is contained in an amount of 12.2 to 40 mass% in 100 mass% of the insulating layer. By including the black coloring agent in an amount of 12.2 to 40 mass%, the insulating layer is easily compatible with good printability and insulation.

(Surface Resistance Value of Insulating Layer) In the electromagnetic wave shielding sheet of the first embodiment, it is preferable that the surface resistance value of the insulating layer is 1 x 10 ⁵ to 1 x 10 ¹⁴ Ω / □. The insulation resistance is further improved by setting the surface resistance value of the insulation layer to 1 10 ⁵ ? /? Or more. Further, when the surface resistance value is 1 x 10 &lt; ¹⁴ &gt; OMEGA / &amp; squ &amp; or less, the coating property is further improved, for example, when the insulating layer is formed by coating the black resin composition.

(Preparation of insulating layer) The method of producing the insulating layer is not particularly limited, but it can be formed, for example, by coating a black resin composition on a peelable sheet. Further, the black resin composition can be formed by extruding into a sheet form using an extrusion molding machine such as a T-die.

The coating can be carried out by various coating methods such as a gravure coat method, a kiss coat method, a die coat method, a lip coat method, a comma coat method, a blade method, a roll coat method, a knife coat method, a spray coat method, a bar coat method, A known coating method such as a coating method can be used. During the coating, a drying step may be provided as necessary. A known drying apparatus such as a hot air dryer and an infrared heater may be used for the drying.

The thickness of the insulating layer can be appropriately designed depending on the application, but is preferably about 0.5 탆 to 25 탆, more preferably about 2 탆 to 15 탆.

<Conductive adhesive layer> The conductive adhesive layer according to the first embodiment is formed of a conductive resin composition containing a binder resin and conductive fine particles. By having adhesiveness, the electromagnetic wave shielding sheet can be bonded to the cover film, the insulating substrate, and the like constituting the printed wiring board through the conductive adhesive layer.

The conductive adhesive layer formed of the conductive resin composition is preferably an isotropic conductive adhesive layer or an anisotropic conductive adhesive layer. The isotropic conductive adhesive layer has conductivity in the vertical direction and the horizontal direction in a state where the electromagnetic wave shielding sheet is placed horizontally. Further, the anisotropic conductive adhesive layer has conductivity only in the substantially vertical direction when the electromagnetic shielding sheet is placed horizontally. In view of cost reduction, an anisotropic conductive adhesive layer is preferable.

As the binder resin, thermosetting resin (B1) and thermoplastic resin (B3) can be used. These can be appropriately selected from the thermosetting resin (A1) and the thermoplastic resin (A3) described in the insulating layer. When the thermosetting resin (B1) is used, it is preferable to use the curing agent (B2) described in the insulating layer. The preferred compound of the curing agent (B2) is the same as the above-mentioned curing agent (A2). Further, the thermosetting resin (A1) and the thermoplastic resin (A3) used for the binder resin do not need to match those of the resin used in the insulating layer and can be independently selected. This also applies to the curing agent A2.

The binder resin preferably has a glass transition temperature (Tg) of -20 to 100 캜, more preferably 0 to 80 캜. The binder resin may be used in one kind or in combination of several kinds. When a plurality of kinds are used, it is preferable that the main component is that the Tg before mixing is included in the above range. Further, Tg was measured using "DSC-1" manufactured by Mettler-trad.

The conductive fine particles as the conductive filler are preferably conductive metals such as gold, platinum, silver, copper and nickel, and fine particles of the alloy and conductive polymer. In terms of cost reduction, it is preferable that the composite fine particles are made of a metal or a resin as a core and a coating layer covering the surface of the core is formed of a material having higher conductivity than the core.

The nucleus is preferably selected from nickel, silica, copper and resin, more preferably a conductive metal and an alloy thereof.

The covering layer is a material having excellent conductivity, and a conductive metal or a conductive polymer is preferable. The conductive metal may be, for example, gold, platinum, silver, tin, manganese, indium, and the like and alloys thereof. As the conductive polymer, polyaniline, polyacetylene and the like can be mentioned. Among them, silver is preferable in terms of conductivity. The conductive fine particles may be used singly or in combination of two or more kinds.

The composite fine particles preferably have a coating layer at a ratio of 1 to 40 parts by mass with respect to 100 parts by mass of the core, more preferably 5 to 30 parts by mass. When it is coated with 1 to 40 parts by mass, the cost can be saved while maintaining the conductivity. Further, in the composite fine particle, it is preferable that the coating layer completely covers the core. However, in reality, some of the nuclei may be exposed. Even in this case, if the conductive material covers 70% or more of the surface area of the core, the conductivity is easily maintained.

The shape of the conductive fine particles is not limited as long as desired conductivity can be obtained. Specifically, for example, a spherical shape, a flake shape, a leaf shape, a twig shape, a plate shape, a needle shape, a rod shape, and a grape shape are preferable. The conductive fine particles generally have isotropic conductivity when flake-shaped fine particles are used, and anisotropic conductivity is obtained when fine particles having a spherical shape or a twig shape are used.

The average particle diameter of the conductive fine particles is a D50 average particle diameter, preferably 1 to 100 mu m, more preferably 3 to 50 mu m.

The D50 average particle diameter was a value obtained by measuring the conductive fine particles with a toned dry powder sample module using a laser diffraction / scattering method particle size distribution measuring apparatus LS13320 (manufactured by Beckman Coulter), and cumulative The particle diameter is 50%. The refractive index was set to 1.6.

The conductive fine particles are preferably blended in an amount of 50 to 1500 parts by weight, more preferably 100 to 1000 parts by weight, based on 100 parts by weight of the binder resin.

The conductive resin composition preferably further contains an ion-catching agent. By mixing the ion-catching agent, when the conductive fine particles are metal fine particles, it is possible to suppress deterioration of conductivity and adhesion due to metal ions with time.

Ion catching agents include, for example, acetylacetone, ethyl acetoacetate, N-sariocyloyl-N'-aldihydrazine, N, N-dibenzal (oxal hydrazide), isophthalic acid bis (2-phenoxypropionyl N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, and the like. Among them, decamethylenecarboxylic acid disalicyloyl hydrazide and N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine have a high ion capture effect desirable.

The ion-catching agent is preferably incorporated in an amount of 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the conductive fine particles. 0.5 to 30 parts by mass of the composition can further suppress deterioration of conductivity and heat resistance with time.

The conductive resin composition preferably further comprises a thickening agent. By including the thickening agent, the dispersion stability of the conductive fine particles is improved in the conductive resin composition. As the thickening agent, for example, silica powder, organic bentonite, polycarboxylic acid compound, polyurethane compound, urea compound, polyamide compound and the like are preferable. The conductive resin composition may further contain a silane coupling agent, a rust inhibitor, a reducing agent, an antioxidant, a pigment, a dye, a tackifier resin, a plasticizer, an ultraviolet absorber, a defoaming agent, a leveling agent, a filler and a flame retardant.

The conductive resin composition can be obtained by mixing and stirring the conductive fine particles and the binder resin. For stirring, a known stirrer can be used, and a dispermat or a homogenizer is preferable.

The conductive adhesive layer can be produced by the same method as the insulating layer.

The thickness of the conductive adhesive layer formed of the conductive adhesive composition is preferably 1 to 100 占 퐉, more preferably 3 to 50 占 퐉, and still more preferably 4 to 15 占 퐉. It is easy to achieve both conductivity and other physical properties within a range of 1 to 100 mu m in thickness.

<Modifications> The electromagnetic wave shielding sheet according to the first embodiment is not limited to the lamination structure shown in FIG. 1 (a), and can have various configurations. For example, an electromagnetic wave shielding sheet 4 in which a conductive layer 3 is laminated between an insulating layer 1 and a conductive adhesive layer 2 can be used as shown in Fig. 1 (b). As the conductive layer 3, a metal thin film layer and a conductive adhesive layer are most suitable. A functional layer such as a layer having functions such as hard coat property, water vapor barrier property, oxygen barrier property, low dielectric constant (low dielectric constant), high dielectric constant or heat resistance may be laminated.

The conductive adhesive layer and the metal thin film layer can be laminated by, for example, laminating a metal thin film layer on a peelable sheet and separately forming an anisotropic conductive adhesive layer on the peelable sheet on the metal thin film surface .

As the metal thin film layer, for example, conductive metal foil of aluminum, copper, silver and gold is preferable, and copper, silver and aluminum are more preferable in shielding property and cost, and copper is even more preferable. The copper is preferably a rolled copper foil or an electrolytic copper foil, and it is more preferable that the rolled copper foil is etched and the electrolytic copper foil is considered considering the thinness of the metal thin film layer. In the case of metal foil, the thickness is preferably 0.1 to 10 mu m, more preferably 0.5 to 5 mu m.

The metal thin film layer may be formed by vacuum deposition, sputtering, CVD, metal organic (MO), plating or the like in addition to the metal foil. Among these, vacuum deposition and plating are preferable considering mass productivity. The vapor deposition film, the sputtering film and the metal plating film are preferably formed of a conductive metal material such as aluminum, copper, silver and gold, and more preferably copper, silver and aluminum. The thickness of the metal thin film layer other than the metal foil is usually about 0.005 to 5 mu m. The thickness of the metal vapor deposition film is preferably 0.1 to 3 mu m. The thickness of the sputtering film is preferably 10 to 1000 nm. The thickness of the metal plating film is usually 0.5 to 5 mu m.

&Lt; Method for producing electromagnetic wave shielding sheet > The electromagnetic wave shielding sheet according to the first embodiment can be manufactured by a known method and is not particularly limited. The laminate of Fig. 1 (a) is obtained, for example, by adhering an electrically conductive adhesive layer previously prepared on a peelable sheet and a separately prepared insulating layer. The laminate of Fig. 1 (b) can be obtained by, for example, forming a metal thin film layer, which is a conductive layer having isotropic conductivity, on a peelable sheet and separately forming a conductive adhesive layer such as anisotropic conductivity on the peelable sheet (I) is formed on the surface of the metal thin film layer, and then the separately produced insulating layer is peeled off and peeled off the surface of the metal thin film layer.

The electromagnetic shielding sheet of the first embodiment is preferably provided in a state in which a part of the crosslinkable functional group of the thermosetting resin and a part of the functional group of the curing agent (A2) are in a reaction state (semi-cured state (B stage)) . It is preferable that the remaining crosslinkable functional group of the thermosetting resin and the functional group of the curing agent (A2) react with each other after curing (C stage). For example, in many cases, a desired adhesive strength is obtained by laminating or pasting an electromagnetic wave shielding sheet to an FPC (flexible printed wiring board), and then sufficiently curing by a heat pressing process.

In order to facilitate the protection and handling of the conductive adhesive layer or the insulating layer, the electromagnetic wave shielding sheet is often stored in a state in which the release sheet is stuck up to just before use. The releasable sheet is preferably a sheet of paper or plastic, and is a sheet having a known releasing treatment on one side of the substrate or a sheet having an adhesive layer of a fine adhesive force instead of the peeling treatment.

<Printed wiring board> The printed wiring board according to the first embodiment includes an electromagnetic wave shielding sheet, a cover coat layer, and a wiring board including a signal wiring and an insulating substrate. Factors such as a product number and a lot number are formed on the insulating layer of the electromagnetic wave shielding sheet.

2 is a schematic cross-sectional view of an example of a printed wiring board according to the first embodiment. Here, the electromagnetic wave shielding sheet 4 will be described with reference to the example of Fig. 1 (b), but it may be applied to other electromagnetic wave shielding sheets including Fig. 1 (a). In the printed wiring board 10, a ground wiring 8, a wiring circuit 9 and the like are formed on an insulating base 7, and a cover coat layer 6 is laminated so as to cover them. An electromagnetic wave shielding sheet 4 is laminated on the cover coat layer 6.

The cover coat layer 6 is an insulating material covering the signal wiring of the wiring board and protecting it from the external environment. The cover coat layer 6 is preferably a polyimide coverlay with adhesive, a thermosetting or ultraviolet curing type solder resist, or a photosensitive coverlay film, and a photosensitive coverlay film is more preferable for microfabrication. The signal wiring includes a ground wiring 8 that takes the ground, and a wiring circuit 9 that sends electric signals to the electronic parts. Both are generally formed by etching the copper foil.

When the wiring board is a flexible printed wiring board (FPC), the insulating substrate 7 is preferably a flexible plastic such as polyester, polycarbonate, polyimide, or polyphenylene sulfide, and polyimide is more preferable. When the wiring board is a rigid wiring board, the constituent material of the insulating base 7 is preferably a glass epoxy. By providing such an insulating substrate 7, the wiring board has high heat resistance.

The heat-sealing of the electromagnetic wave shielding sheet 4 and the wiring board is generally performed under the conditions of a temperature of about 150 to 190 DEG C, a pressure of about 1 to 3 MPa, and a time of about 1 to 60 minutes. The conductive adhesive layer 2 and the cover coat layer 6 are brought into close contact with each other by hot pressing so that the conductive adhesive layer 2 flows at the same time to fill the hole (contact hole) 11 with the ground wiring 8 . Further, when the thermosetting resin (A1) is used, the thermosetting resin (A1) and the curing agent (A2) react with each other by hot pressing. In order to promote curing, Post-cure may be carried out at 150 to 190 ° C for 30 to 90 minutes after hot pressing. Further, the electromagnetic wave shielding sheet may be referred to as an electromagnetic wave shielding layer after hot pressing.

(Ink for printing) As ink for printing, silk screen ink, ink jet ink and the like can be mentioned. A coloring agent, a binder resin, an additive and a solvent. The solvent is appropriately selected from organic solvents having a boiling point of 40 to 140 캜, from the viewpoint of printability. Further, from the viewpoint of the print visibility, it is preferable that the ink is a white printing ink.

After hot pressing, the lot number and the product number can be printed on the surface of the insulating layer 1 of the electromagnetic wave shielding sheet by the printing ink using silk screen printing, inkjet printing or the like. The character size to be printed is usually 1 to 10 points. After printing, the printed material is cured by drying in an oven at 100 to 170 캜 to adhere to the insulating layer 1. The insulating layer 1 is black. In order to improve the visibility, the color of the element is preferably white.

The printed wiring board of the first embodiment can be suitably applied to general electronic devices such as a notebook computer, a mobile phone, a smart phone, and a tablet terminal in addition to a liquid crystal display and a touch panel.

&Lt; Effect > In Patent Document 1, although the adhesive layer is colored, there is a problem that the color of the coloring is poor and it is difficult for the operator to visually recognize the factor. On the other hand, according to the electromagnetic wave shielding sheet according to the first embodiment, the characters printed on the insulating layer are excellent in visibility by satisfying [1a] to [1e]. Therefore, the workability of FPC sorting when the FPC is mounted on the electronic apparatus is improved, and the productivity is also improved.

[Second Embodiment]

Hereinafter, an electromagnetic wave shielding sheet different from the above-described embodiment will be described, but overlapping descriptions will be omitted as appropriate. The electromagnetic wave shielding sheet according to the second embodiment contains a black coloring agent, and is similar to the first embodiment in that at least an insulating layer and a conductive adhesive layer are provided. The insulating layer of the second embodiment is formed of a black resin composition containing [2a] a thermosetting resin (A1), a curing agent (A2) and the black colorant, [2b] 110 °.

The electromagnetic shielding sheet according to the second embodiment can be suitably applied to the laminated body shown in Figs. 1 (a) and 1 (b) and the laminated structure of the various functional layers described in the first embodiment.

&Lt; Insulating layer > The insulating layer according to the second embodiment satisfies the above-mentioned [2a] and [2b].

[2a]: Black resin composition and coating film

The insulating layer is formed of a black resin composition containing a thermosetting resin (A1), a curing agent (A2) and the black coloring agent. As the thermosetting resin (A1), the curing agent (A2) and the black coloring agent, resins and compounds similar to those in the first embodiment can be used. The black colorant is preferably contained in an amount of 2 to 25 mass%, more preferably 4 to 15 mass%, in 100 mass% of the insulating layer. By including the black coloring agent in an amount of 2 to 25 mass%, the insulating layer easily achieves good print visibility and insulation reliability.

(Surface Conditioning Agent) In the black resin composition according to the second embodiment, it is preferable to add a surface conditioner to adjust the wettability of the surface. As the surface conditioner, a wax, a leveling agent, a surfactant, a silane coupling agent, an inorganic filler and the like can be mentioned, and wax, leveling agent, silane coupling agent and inorganic filler are preferable, and wax, leveling agent and inorganic filler are more preferable . The above surface modifier may be used alone or in combination of two or more. Concretely, it is preferable to use the wax and the inorganic filler or the combination of the leveling agent and the inorganic filler. In the black resin composition of the second embodiment, it is easy to adjust the contact angle of the surface of the insulating layer with water to 60 to 110 ° by adding the surface control agent, thereby improving the print visibility and ink film adhesion.

Examples of the wax include natural waxes such as animal waxes such as candelilla wax, calabana wax, rice wax, wood wax, jojoba oil, beeswax, lanolin, whale wax, montan wax, ozokerite, Petroleum waxes such as mineral waxes, paraffin waxes, microcrystalline waxes and petrolatum, synthetic waxes such as synthetic waxes such as fish wax and polyethylene wax, montan wax derivatives, paraffin wax derivatives, microcrystalline wax derivatives Hydrogenated waxes such as hardened castor oil and hydrogenated castor oil derivatives, fatty acids such as lanolin acid, palmitic acid, myristic acid, stearic acid, and 12-hydroxystearic acid.

The melting point of these waxes is in the range of 30 to 140 占 폚, preferably 60 to 120 占 폚. If the melting point of the wax is less than 30 캜, the wax tends to be contaminated by the bleeding out of the wax. When the melting point of the wax exceeds 140 캜, high abrasion resistance is hardly developed.

The mixing ratio of the thermosetting resin (A1) and the wax is preferably 0.5 to 40 parts by mass, more preferably 1 to 20 parts by mass, relative to 100 parts by mass of the thermosetting resin (A1). When the amount of the wax is less than 0.5 parts by mass with respect to 100 parts by mass of the thermosetting resin (A1), the effect on abrasion resistance can not be expected to be expected. On the other hand, when the amount of the wax is more than 40 parts by mass, bleeding occurs and further deterioration of other properties There is a case.

As the leveling agent, a polyether structure, a polyester structure, an aralkyl structure, a polysiloxane having an acrylic group, and an acrylic copolymer may be used in the main chain. Specific examples of the dimethylsiloxane having a polyether structure in the main chain include FZ-2110, 2122, 2130, 2166, 2191, 2203, 2207, BYK-330, BYK-323 and BYK-348 manufactured by Dow Corning Toray Co., . Specific examples of the dimethylsiloxane having a polyester structure in the main chain include BYK-310 and BYK-370 manufactured by BICKEMISA. Specific examples of the polymethylsiloxane having an aralkyl structure in the main chain include BYK-322 and BYK-323 manufactured by BICKEMISA. Specific examples of the polydimethylsiloxane having an alkyl group in the main chain include BYK-3500, BYK-3505, BYK-3530 and BYK-3570 manufactured by BIGKEMISA. Specific examples of the acrylic copolymer system include BYK-350, BYK-354, BYK-355, BYK-358, BYK-381, BYK-392, BYK-394 and BYK-3441.

As the surfactant, anionic, nonionic, amphoteric and cationic surfactants are generally known, and any of them can be used.

Examples of the anionic surfactant include alkyl sulfosuccinate salts, alkylsulfuric acid ester salts, alkyl ether sulfuric acid ester salts, monoalkyl phosphoric acid ester salts, alpha olein sulfonic acid salts, .

Examples of the nonionic surfactant include glycerin fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, fatty acid alkanolamides, polyoxyethylene alkyl ethers, And polyoxyethylene alkyl phenyl ether.

Examples of amphoteric surfactants include alkylamino fatty acid salts, alkyl betaines, alkylamine oxides, and the like.

Examples of the cationic surfactant include alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts and N-methylbishydroxyethylamine fatty acid ester hydrochloride.

In addition, reactive surfactants such as fluorine-based surfactants and allyl-based reactive surfactants, and polymeric surfactants such as cationic cellulose derivatives, polycarboxylic acids, and polystyrenesulfonic acid can also be used. Disperbyk-101, Disperbyk-101, and EFKA5207 (all of which are manufactured by EFKA Additives) are also commercially available as wetting dispersants. Examples thereof include EFKA5010, EFKA5044, EFKA5244, EFKA5054, EFKA5055, EFKA5063, EFKA5064, EFKA5065, EFKA5066, EFKA5070, EFKA5071, 108, and Disperbyk-130 (manufactured by Big Chem Japan).

These surfactants may be used singly or in combination of two or more, or a combination of surfactants and compounds other than surfactants may be used.

As the silane coupling agent, for example, a vinyl silane coupling agent, an epoxy silane coupling agent, an amino silane coupling agent, a methacrylic coupling agent, a thiol coupling agent and an isocyanate silane coupling agent can be used.

As the vinyl silane coupling agent, for example, vinyltrimethoxysilane, vinyltriethoxysilane and the like can be mentioned.

Examples of the epoxy silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, and the like.

Examples of the amino silane coupling agent include N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3- Propyl trimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N- And so on.

Examples of the methacrylic silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and the like.

As the thiol-based silane coupling agent, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like can be mentioned.

As the isocyanate-based silane coupling agent, for example, 3-isocyanate propyl triethoxysilane and the like can be mentioned.

The blending amount of the silane coupling agent to the black resin composition is preferably from 0.1 to 25 parts by mass, more preferably from 0.5 to 15 parts by mass relative to 100 parts by mass of the thermosetting resin (A1).

Examples of the inorganic filler include inorganic compounds such as silica, alumina, aluminum hydroxide, magnesium hydroxide, barium sulfate, calcium carbonate, titanium oxide, zinc oxide, antimony trioxide, magnesium oxide, talc, montmorillonite, kaolin and bentonite have.

The ratio of the added amount of the black coloring agent to the surface adjusting agent in the black resin composition is preferably 100: 0.01 to 100: 10, more preferably 100: 0.05 to 100: 5. When the ratio is set at the above ratio, the black coloring agent is coated on the peelable sheet to suppress drying unevenness, so that the insulating layer can be uniformly coated, and the print visibility is improved. Further, it is preferable because the ink resistance is improved.

As the additive other than the black coloring agent, the additive exemplified in the first embodiment may be added to the black resin composition as required.

[2b] Contact angle of the surface of the insulating layer with water

In the electromagnetic wave shielding sheet of the second embodiment, the contact angle of the surface of the insulating layer with water is 60 to 110 degrees. By setting this range, the ink wettability is improved and characters printed on the insulating layer can be prevented from smearing and can be brought into close contact with the surface of the insulating layer. The water contact angle becomes 60 DEG or more, and the ink wettability improves, so that a blotting-free and visually satisfactory print becomes possible. When the glossiness is 110 ° or less, the ink film adhesion to the surface of the insulating layer is further improved. A more preferable range of the water contact angle of the insulating layer is 70 to 100 DEG. The contact angle of the surface of the insulating layer with water can be controlled by the composition of the black resin composition described later, the surface irregularities (surface roughness Ra) of the insulating layer, and the like. The water contact angle is a value after thermosetting of the electromagnetic wave shielding sheet, and a measuring method will be described later.

(Average Primary Particle Diameter of Black Coloring Agent) The black coloring agent preferably has an average primary particle diameter of 10 to 200 nm, more preferably 20 to 100 nm. By using the black coloring agent having an average primary particle diameter, the insulating layer can be colored in a clear black color without spots, and the visibility of characters is further improved. Also, by setting the average primary particle diameter to 10 nm or more, it is easy to maintain the viscosity of the black resin composition at a level suitable for the coating. In addition, when the average primary particle diameter is 200 nm or less, the whiteness of the insulating layer is improved, and the print visibility is further improved. When the particle shape of the black colorant has an average aspect ratio (major axis length / minor axis length) of 1.5 or more, the average primary particle diameter is obtained by averaging the major axis length.

(Martens hardness of the insulating layer) The insulating layer of the electromagnetic wave shielding sheet of the second embodiment preferably has a Martens hardness of 20 to 300, more preferably 50 to 200. Since the hardness of Martens is 20 to 300, the ink resistance and the repulsive force are improved.

(Coefficient of Friction of Insulating Layer) The insulating layer of the electromagnetic shielding sheet of the second embodiment preferably has a coefficient of dynamic friction of 0.01 to 0.5, more preferably 0.05 to 0.4. The coefficient of dynamic friction is 0.01 to 0.5, the wettability of the ink is improved, the characters printed on the insulating layer are free from blurring, and the print visibility is improved because they adhere to the surface of the insulating layer.

(Gloss of insulating layer) The preferable range of the surface gloss of the insulating layer according to the second embodiment is the same as that of the first embodiment. A method of imparting a predetermined gloss value to the surface of the insulating layer is also the same as that of the first embodiment.

(Reflectance of Insulating Layer) In the electromagnetic wave shielding sheet of the second embodiment, the reflectance at the surface of the insulating layer at 400 to 780 nm is preferably 10% or less. When the reflectance at 400 to 780 nm is in the above range, reflection of light at each wavelength of the surface of the insulating layer is suppressed, and characters printed in white or the like can be more clearly seen.

(Surface resistance value of the insulating layer) The preferable range is the same as that of the electromagnetic wave shielding sheet of the first embodiment.

(Fabrication of insulation layer) The insulation layer according to the second embodiment can be manufactured in the same manner as the insulation layer production method according to the first embodiment. The black resin composition can be obtained by mixing and stirring other thermosetting resin (A1) and curing agent (A2) with a thermosetting resin solution prepared by dispersing a black coloring agent. For stirring, a known stirrer may be used, and a dispenser mat, a homogenizer and the like are preferable.

The thickness of the insulating layer according to the second embodiment can be suitably designed in accordance with the application, but is preferably 3 to 20 占 퐉, more preferably 5 to 15 占 퐉. By setting the thickness of the insulating layer to 3 to 20 占 퐉, the print visibility and ink resistance can be improved and the repulsive force of the FPC with the electromagnetic shielding sheet can be lowered.

&Lt; Conductive adhesive layer > The conventionally known conductive adhesive layer according to the second embodiment may be used. For example, the conductive adhesive layer can be formed by a conductive resin composition comprising a thermosetting resin (B1), a curing agent (B2), and a conductive adhesive containing a conductive filler. The method of manufacturing the conductive adhesive layer according to the second embodiment and the preferred thickness thereof are the same as those of the first embodiment. The preferable types, content ratios, shapes, and average particle diameters of the thermosetting resin (B1), the curing agent (B2), and the conductive filler are the same as those of the first embodiment.

When the isotropic conductive adhesive layer is formed, the conductive fine particles are preferably blended in an amount of 100 to 1500 parts by mass, more preferably 200 to 1000 parts by mass, per 100 parts by mass of the thermosetting resin (B1). When an anisotropic conductive adhesive layer is formed, 10 to 200 parts by mass of the thermosetting resin (B1) is preferably blended with 100 parts by mass of the thermosetting resin (B1), more preferably 20 to 150 parts by mass.

The conductive adhesive composition according to the second embodiment may contain a silane coupling agent, a rust inhibitor, a reducing agent, an antioxidant, a pigment, a dye, a tackifier resin, a plasticizer, an ultraviolet absorber, a defoamer, a leveling regulator, a filler and a flame retardant.

The method of obtaining the conductive adhesive composition can be exemplified by the method of the first embodiment.

Modified Example The electromagnetic wave shielding sheet according to the second embodiment can have various configurations as in the first embodiment. For example, as shown in Fig. 1 (b), an electromagnetic wave shielding sheet 4 in which a conductive layer 3 made of a metal thin film layer or the like is laminated between the insulating layer 1 and the conductive adhesive layer 2 can be used . The conductive adhesive layer may be composed of two layers. For example, a conductive adhesive layer (also referred to as conductive adhesive layer (I)) on the side of the surface layer can be formed as an anisotropic conductive adhesive layer, and a conductive layer exhibiting isotropic conductivity between the conductive adhesive layer and the insulating layer can be laminated. This configuration is preferable particularly for applications requiring high electromagnetic wave shielding properties. A preferable isotropic conductive layer (hereinafter also referred to as an isotropic conductive layer) may be a metal thin film layer or a conductive adhesive layer (hereinafter referred to as conductive adhesive layer (II)). A metal thin film layer is preferable from the viewpoint of improving the electromagnetic wave shielding property and transmission characteristics for a high frequency signal of 100 MHz to 20 GHz. On the other hand, from the viewpoint of heat resistance such as reflow soldering, it is preferable to laminate the conductive adhesive layer (II).

An example in which the method and the kind of the metal thin film layer are preferable is the same as that of the first embodiment. The thermosetting resin constituting the conductive adhesive layer (II) may be the same as the case of having the isotropic conductivity in the conductive adhesive layer (I). The conductive adhesive layer (II) can be produced using a conductive adhesive composition for forming the conductive adhesive layer (I). Additives and the like can be selected and used in the same examples as needed.

The conductive fine particles to be used in the conductive adhesive layer (II) are preferably blended in an amount of 300 to 2000 parts by mass, more preferably 500 to 1500 parts by mass, based on 100 parts by mass of the thermosetting resin. The thickness of the conductive adhesive layer (II) at this time is preferably 2 to 15 mu m, more preferably 3 to 10 mu m. The conductive filler used for the conductive adhesive layer (II) preferably has a flake shape or a twig shape. By using a conductive filler having a flake shape or a twig shape, high conductivity can be exhibited with a thinner film thickness, and the repulsive force can be lowered.

<Printed wiring board> As in the first embodiment, a printed wiring board can be manufactured by using the above-described electromagnetic wave shielding sheet according to the second embodiment. As a suitable example of the printed wiring board, Fig. 2 can be exemplified.

&Lt; Effect > The FPC is performed by printing the product number and lot number on the insulating layer of the laminated electromagnetic wave shielding sheet. However, in the conventional electromagnetic wave shielding sheet, There is a problem of argument visibility that it is difficult to recognize. In addition, when the printing is peeled off due to contact with another member due to low adhesion of the printing ink, or when the resistance to the solvent contained in the printing ink is low, the hardness of the coating film is lowered and the printing property is lowered but the film strength is lowered A problem of ink resistance may occur. Further, if the film thickness of the insulating layer is increased in order to improve the print visibility and the ink resistance, the repulsive force of the FPC attached with the electromagnetic wave shielding sheet becomes strong, and the handling performance deteriorates at the time of implementation.

On the other hand, according to the electromagnetic shielding sheet according to the second embodiment, excellent print visibility can be realized as in the first embodiment. In addition, it has an excellent effect of preventing occurrence of blurring by use of commonly used printing ink. Therefore, it is easy for an operator to acknowledge an argument even if a small character is printed. In particular, when the factor is white, the factor visibility can be improved more effectively. Further, it is possible to provide an electromagnetic wave shielding sheet excellent in adhesion of ink for printing and ink resistance. Further, even when attached to an FPC, an electromagnetic wave shielding sheet having a low repulsive force can be provided.

[Third embodiment]

The electromagnetic wave shielding sheet according to the third embodiment contains a black coloring agent and includes at least an insulating layer and a conductive adhesive layer. The insulating layer may be formed of a transparent resin composition containing [3a] a transparent resin, or [3b] the surface has a contact angle with water of 60 to 110 °. The [3c] black colorant is contained in the black layer positioned between the insulating layer and the conductive adhesive layer.

Fig. 3 (a) shows a cross-sectional view of an example of the electromagnetic wave shielding sheet according to the third embodiment. The electromagnetic shielding sheet 4 has a structure in which a conductive adhesive layer 2, a black layer 5 and an insulating layer 1 are laminated in this order as shown in the drawing. Hereinafter, each layer will be described in detail.

&Lt; Insulating layer > The insulating layer according to the third embodiment satisfies the above-mentioned [3a] and [3b].

[3a]: Transparent resin composition and coating film

The insulating layer according to the third embodiment is different from the first and second embodiments in that it does not contain a black coloring agent. That is, the insulating layer according to the third embodiment is formed by using a transparent resin composition having insulating properties. The transparent resin composition can be formed using a known composition. As a good example, there is a composition containing at least one of (3a-i) a photo-curing resin, an initiator and (3a-ii) a thermosetting resin and a curing agent. It may also be used in combination with a thermoplastic resin. The transparency in the third embodiment means that the spectral transmittance in an entire wavelength range of 400 to 700 nm is 30% or more in actual use. The spectral transmittance is preferably 40% or more, more preferably 50% or more. If the spectral transmittance is 30% or more, a resin layer such as a salt yellow or milky white can be used. Since the spectral transmittance of the insulating layer is in this range, an electromagnetic wave shielding sheet having good visibility can be obtained because it reflects black of the black layer to be described later.

The photo-curing resin and the thermosetting resin may be used alone, but they are preferably used together from the viewpoints of ink resistance and insulation reliability. Suitable compounds and contents of the thermosetting resin (A1), the curing agent (A2) and the thermoplastic resin (A3) are the same as those of the first embodiment.

The photo-curing resin may be a resin having at least one unsaturated bond which causes a crosslinking reaction by light, and examples thereof include acrylic resins, maleic acid resins, polybutadiene resins, polyester resins, polyurethane resins, Examples of the resin include resins, oxetane resins, phenoxy resins, polyimide resins, polyamide resins, phenol resins, alkyd resins, amino resins, poly lactic acid resins, oxazoline resins, benzoxazine resins, silicone resins, have.

The photo-curing resin may have a functional group used for a crosslinking reaction upon heating.

Examples of the initiator include 4-t-butyldichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy- Methyl-1- [4- (methylthio) phenyl] -2-methyl-1 H- 2-morpholinopropane-1-one, and the like; a photopolymerization initiator such as 1,2-octadione-1- [4- (phenylthio) -, 2- (o-benzoyloxime)], Oxime ester photopolymerization initiators such as 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -, 1- (o- acetyloxime), benzoin, benzoin methyl ether , Benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal; benzophenone based photopolymerization initiators such as benzophenone, benzoyl benzoic acid, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, -4'-methyldiphenyl sulfide and the like Based photopolymerization initiator such as a phenanthrene-based photopolymerization initiator, thioxanthone, 2-crothioxanthene, 2-methylthioxanthene, isopropylthioxanthene and 2,4-diisopropylthioxanthene, 4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloro Bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s (Trichloromethyl) -6-styryl-s-triazine, 2- (naphtho-1-yl) (Trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6- (4-methoxy- Triazine, and 2,4-trichloromethyl (4'-methoxystyryl) -6-triazine, a borate-based photopolymerization initiator, a calbazole-based photopolymerization initiator, or an imidazole-based photopolymerization initiator Initiators and the like are used. These photopolymerizable compounds can be used singly or as a mixture of two or more kinds in an optional ratio as required.

Particularly, the acetophenone-based photopolymerization initiator and the oxime ester-based photopolymerization initiator are preferable because the yellowing is small and the transmittance is high during the heating process. Specific examples of the acetophenone photopolymerization initiator include Irgacure 907 (manufactured by BASF), Irgacure 379 (manufactured by BASF), Irgacure 379EG (manufactured by BASF), and the like.

Among them, the oxime ester-based photopolymerization initiator is particularly preferable because it has high sensitivity and can reduce the amount of addition. These may be used alone or in combination.

Among the oxime ester photopolymerization initiators, 1,2-octadione-1- [4- (phenylthio) phenyl-, 2- (o-benzoyloxime)], ethanol, 1- [ (Methylbenzoyl) -9H-carbazol-3-yl] - and 1- (o-acetyloxime) exhibit a yellowing property at the time of heating and a high transmittance as a coating film and a high transmittance at a wavelength of around 400 nm More preferable. These may be used alone or in combination. Specific examples thereof include Irugacure OXE01 (manufactured by BASF), Irugacure OXE02 (manufactured by BASF), and the like.

The initiator is preferably used in an amount of 0.5 to 10 mass%, preferably 0.5 to 5 mass%, based on 100 mass% of the total solid content of the transparent resin composition.

The transparent resin composition may further contain, as a sensitizer, at least one of? -Acyloxyester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethyl anthranquinone, 4,4'-di Ethyl isophthalophenone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, and 4,4'-diethylaminobenzophenone may be used in combination.

The sensitizer may be used in an amount of 0.1 to 150 parts by mass based on 100 parts by mass of the initiator.

It is preferable to further add a surface conditioner to the transparent resin composition. Suitable compounds of the surface modifier and characteristics of the melting point and the like are the same as those of the second embodiment. The blending ratio of the wax used in the third embodiment is preferably 0.5 to 40 parts by mass of wax relative to 100 parts by mass of resin (photocurable resin and / or thermosetting resin (hereinafter the same)), more preferably 1 to 20 parts by mass desirable. If the wax content is less than 0.5 parts by mass with respect to 100 parts by mass of the resin, the effect of abrasion resistance can not be expected. On the other hand, if the wax content is more than 40 parts by mass, bleedout may occur and other properties may be deteriorated.

The blending ratio of the resin and the silane coupling agent is preferably 0.1 to 25 parts by mass, more preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the resin.

The ratio of the addition amount of the resin component of the photocurable resin and the thermosetting resin (A1) in the transparent resin composition to the surface control agent is preferably 100: 0.01 to 100: 10, more preferably 100: 0.05 to 100: 5. By controlling the ratio, it is possible to coat the transparent resin composition more uniformly by suppressing drying unevenness after coating on the releasable sheet to improve the print visibility and insulation reliability. And furthermore, the ink resistance is improved.

The transparent resin composition may contain a photo-curable monomer, a photo-curable oligomer, a rust inhibitor, a reducing agent, an antioxidant, a tackifier resin, a plasticizer, an ultraviolet absorber, a defoaming agent, a leveling agent, a filler and a flame retardant. In addition, pigments, dyes and the like may be contained within a range not impairing transparency.

[3b]: Contact angle of the surface of the insulating layer with water

In the electromagnetic wave shielding sheet of the third embodiment, the contact angle of the surface of the insulating layer with water is 60 to 110 degrees. The reason and the measurement method are as described in the second embodiment.

(Surface Resistance Value) The insulation reliability can be excellent because the surface resistance value (substantially the surface resistance value of the insulating layer) measured on the insulating layer side is 1 x 10 ⁵ to 1 x 10 ¹⁴ Ω / square.

(Thickness) The thickness of the insulating layer can be suitably designed in accordance with the application, but is preferably 1 to 10 mu m, more preferably 3 to 8 mu m. By setting the thickness of the insulating layer to 1 to 10 mu m, ink resistance and insulation reliability can be improved and the repulsive force of the FPC having the electromagnetic shielding sheet attached thereto can be reduced.

(Dynamic Friction Coefficient of Insulating Layer) The coefficient of dynamic friction of the insulating layer of the electromagnetic shielding sheet of the third embodiment is preferably 0.01 to 0.5, more preferably 0.05 to 0.4. When the coefficient of dynamic friction is 0.01 to 0.5, the wettability of the ink is improved, and the printed characters on the insulating layer are less likely to bleed and adhere to the surface of the insulating layer, thereby improving the print visibility. The coefficient of dynamic friction is the value of the surface of the insulating layer after thermosetting of the electromagnetic wave shielding sheet, and the measuring method will be described later.

When the insulating layer contains a photo-curing resin and an initiator, the curing reaction proceeds by irradiating the transparent resin layer with light of 200 nm to 450 nm after drying to increase the strength of the coating film. The irradiation of light may be performed on the coated surface of the transparent resin layer. However, when the peelable sheet has a spectral transmittance of 70% or more at 200 nm to 450 nm, it can be irradiated on the surface of the peelable sheet.

&Lt; Black layer > [3c]: Black layer (black colorant)

The black layer according to the third embodiment refers to a case where the spectral transmittance in an entire wavelength range of a wavelength of 400 to 700 nm is less than 30% in the actually used film thickness. The spectral transmittance is preferably less than 20%, more preferably less than 10%. Further, the transmittance of a part of the spectral transmittance at a wavelength of 400 to 700 nm is 30% or more, and in the case of a colored layer other than black, the transmittance does not correspond to the black layer in the third embodiment.

The black layer is a layer colored in black and has a high blackness of black, thereby improving the print visibility. In the electromagnetic shielding sheet of the third embodiment, an insulating layer which is a transparent resin layer having a specific contact angle on the outermost surface is disposed, and the black layer can be made of a conductive black layer using a black coloring agent such as carbon black.

An insulating black layer may also be used. The insulation reliability can be further improved by using the insulating black layer. At this time, the content of the black coloring agent is preferably 2 to 30% by mass, more preferably 4 to 20% by mass, in 100% by mass of the solid content of the black layer.

By using the black layer, it is possible to provide an electromagnetic wave shielding sheet which improves the printability of the flexible wiring board and improves insulation reliability while improving the print visibility.

The surface resistance value of the black layer is preferably in the range of 1 × 10 ⁵ to 1 × 10 ¹⁴ Ω / □ from the viewpoint of improving the insulation reliability.

The thickness of the black layer can be suitably designed in accordance with the application, but is preferably 0.5 to 20 占 퐉, more preferably 1 to 15 占 퐉. By setting the thickness of the black layer to 0.5 to 20 占 퐉, the print visibility can be improved and the repulsive force of the FPC attached with the electromagnetic shielding sheet can be lowered.

(Black resin composition) The black layer according to the third embodiment can use a conventionally known black layer. The black resin layer may be a black resin layer formed of a composition containing a thermosetting resin (C1), a curing agent (C2) . This makes it possible to visually recognize characters printed on the surface of the insulating layer with excellent operability, and more particularly when the factor is white. The black resin composition may contain other coloring agents as required. Suitable examples of the thermosetting resin (C1) and the curing agent (C2) can be selected from the thermosetting resin (A1) and the curing agent (A2) described in the first embodiment.

(Black type coloring agent) The black layer contains a black type coloring agent, so that the visibility of characters printed can be improved. Preferred examples of the black coloring agent are the same as those of the first embodiment. That is, preferred examples of the black pigment and the mixed system coloring coloring agent as the black coloring agent are the same as those of the first embodiment.

The preferred average primary particle diameter of the black colorant is the same as in the second embodiment.

The content of the black coloring agent is preferably 2 to 50 mass%, more preferably 4 to 40 mass%, in 100 mass% of the solid content of the black layer. By including 2 to 40 mass% of the black coloring agent, the black layer can easily achieve both good print visibility and the optimal coating viscosity of the black coloring agent.

The black resin composition may contain, if necessary, pigments and dyes other than the black colorant, and a dispersant, an antioxidant, a tackifier resin, a plasticizer, an ultraviolet absorber, a defoamer, a filler and a flame retardant.

The black resin composition can be obtained by mixing and stirring other thermosetting resin (C2), curing agent (C3) and the like with a thermosetting resin (C1) solution obtained by dispersing a black coloring agent. For stirring, a known stirrer may be used, and a dispenser mat, a homogenizer, etc. are preferable.

The black layer can be formed, for example, by coating a black resin composition on a peelable sheet. Or by extruding the black resin composition into a sheet form by an extrusion molding machine such as a T-die.

As the coating method, the coating method described in the production of the insulating layer of the first embodiment can be suitably used.

<Conductive adhesive layer> As the conductive adhesive layer according to the third embodiment, conventionally known ones can be used. For example, it can be formed by a conductive adhesive composition containing the thermosetting resin (B1), the curing agent (B2), and the conductive filler. Suitable examples of the thermosetting resin (B1) and the curing agent (B2) are the same as those of the first embodiment. The conductive adhesive layer has adhesiveness and can be bonded to a cover film or an insulating substrate formed on a printed wiring board.

 The conductive adhesive layer can be appropriately selected from the isotropic conductive adhesive layer or the anisotropic conductive adhesive layer described in the first embodiment. The conductive adhesive layer can be formed as in the first embodiment by using a conductive adhesive composition. The preferable thickness of the conductive adhesive layer is the same as that of the first embodiment.

The preferable compound, shape and average particle diameter of the conductive filler are the same as those of the first embodiment. The preferred ratio of the coating layer in the case of using the conductive filler as the composite particles is also the same as that in the first embodiment.

The preferable range of the content of the conductive fine particles in the thermosetting resin (B1) in the case of forming the isotropic conductive adhesive layer and the preferable range of the conductive fine particles in the case of forming the anisotropic conductive adhesive layer with respect to the thermosetting resin (B1) This is the same as the embodiment. The conductive adhesive composition can suitably add the same additives as in the second embodiment. The conductive adhesive composition may be prepared by the same method as in the first embodiment.

 &Lt; Electromagnetic wave shielding sheet &

(L * value of the electromagnetic wave shielding sheet) The electromagnetic wave shielding sheet of the third embodiment preferably has an L * value of 10 to 30 in the L * a * b * colorimetric system measured at the insulating layer side. When the L * value is set to 10 to 30, light is absorbed on the surface of the black layer, and for example, characters printed in white can be more clearly seen. In order to obtain such L * value, for example, the black coloring agent is preferably blended in the black layer in an amount of 2 to 50 mass%, more preferably 4 to 40 mass%. It is needless to say that the means for adjusting the L * value to 10 to 30 is not limited to the black coloring agent. When secondary aggregation occurs in the black colorant, the L * value can be adjusted to 10 to 30 by carrying out a crushing treatment with a sand mill or the like, if necessary.

By setting the L * value to 10 or more, the viscosity stability of the black resin composition can be further improved. When the L * value is 30 or less, the print visibility is further improved. The L * value in the L * a * b * colorimetric system of the black layer is preferably 10 to 30, more preferably 20 to 30, and more preferably 20 to 30, in order that the L * value of the electromagnetic shielding sheet in the L * a * b * 30 &lt; / RTI &gt; As the L * value of the black layer is 10 to 30, the L * value of the electromagnetic wave shielding sheet can be set in the range of 10 to 30, and the visibility can be excellent.

(85 占 degree gloss of the electromagnetic wave shielding sheet) The electromagnetic wave shielding sheet of the third embodiment preferably has an 85 占 glossiness of 15 to 50 as measured on the insulating layer side. When the 85 占 glossiness is in this range, the print visibility becomes better.

In order to impart a predetermined gloss to the surface of the insulating layer of the electromagnetic wave shielding sheet, for example, the following method can be used.

The unevenness is formed by sandblasting or the like in advance on the surface to be peeled off of the peelable sheet. By coating the surface with an insulating transparent resin composition, the unevenness of the peelable sheet can be transferred to the insulating layer to give an appropriate gloss.

As another method, the glossiness can be adjusted by performing a treatment such as mechanical polishing on the insulating layer formed as a layer.

Alternatively, it is possible to adjust the gloss of the surface of the insulating layer by adding an additive such as a suitable quenching agent (polish remover) or the like to the insulating transparent resin composition without following this method.

(Reflectivity of Electromagnetic Wave Shielding Sheet) It is preferable to set the reflectance in the same range for the same reason as in the second embodiment.

(Surface Resistance Value of Electromagnetic Wave Shielding Sheet) In the electromagnetic wave shielding sheet of the third embodiment, the surface resistance value of the insulating layer measured at the insulating layer side is preferably 1 x 10 &lt; ⁵ &gt; The surface resistance value of the electromagnetic wave shielding sheet is 1 10 ⁵ ? /? Or more, thereby further improving the insulation reliability.

(Martens Hardness of Electromagnetic Wave Shielding Sheet) The electromagnetic wave shielding sheet of the third embodiment preferably has a Martens hardness of 20 to 300 as measured on the insulating layer side. Since the hardness of Martens is 20 to 300, the ink resistance is improved and the repulsive force is lowered.

The L * value, gloss, reflectance, surface resistance, and Martens hardness are values measured on the insulating layer side using the electromagnetic shielding sheet after thermosetting. The measurement method will be described later.

&Lt; Method of producing electromagnetic wave shielding sheet > The electromagnetic wave shielding sheet of the third embodiment can be manufactured by a known method, and is not particularly limited. A preferable manufacturing method is the same as that of the first embodiment. The electromagnetic wave shielding sheet of the third embodiment may be formed by laminating functional layers other than the conductive adhesive layer and the insulating layer in the same manner as in the first embodiment.

<Modification> The electromagnetic wave shielding sheet according to the third embodiment is not limited to the lamination structure shown in Fig. 3 (a), and can have various configurations. For example, as shown in Fig. 3 (b), a laminate obtained by laminating the conductive adhesive layer 2, the conductive layer 3, the black layer 5, and the insulating layer 1 in this order can be used. It is preferable to use a layer having anisotropic conductivity as the conductive adhesive layer 2 and use a layer exhibiting isotropic conductivity as the conductive layer 3, especially in applications requiring high electromagnetic wave shielding properties. A preferable example of the isotropic conductive layer 3 is a metal thin film layer and a conductive adhesive layer (II) as described in the second embodiment. Examples of highly suitable examples of the kind of the metal thin film layer and the conductive adhesive layer (II), the film forming method, the film thickness, the kind and content of the conductive filler, and the like are the same as those of the second embodiment.

<Printed wiring board> As in the first embodiment, a printed wiring board can be manufactured by using the above-described electromagnetic wave shielding sheet according to the third embodiment. As a suitable example of the printed wiring board, Fig. 2 can be exemplified. The printing ink is also the same as the first embodiment.

&Lt; Effect > The FPC is performed by printing the product number and the lot number on the insulating layer of the laminated electromagnetic wave shielding sheet, but there has been a problem described in the corresponding column of the second embodiment. In addition, there is a method of increasing the carbon concentration of the black layer by providing a black layer in order to improve the print visibility. However, in this method, conductivity is imparted to the surface of the electromagnetic wave shielding sheet, and insulation reliability may be deteriorated. A method of increasing the film thickness of the black layer is also considered. The repulsive force of the FPC having the electromagnetic shielding sheet attached thereto is intensified, and the handling property may be deteriorated at the time of implementation.

On the other hand, according to the electromagnetic wave shielding sheet of the third embodiment, by using an insulating layer composed of a transparent resin layer having a contact angle with water of 60 to 110 degrees and using a black layer, the carbon concentration can be increased or the thickness of the black layer can be increased It is possible to increase the visibility of the ink when printing on the insulating layer without making it thick. Further, with the above-described constitution, the wettability of the ink is good and blurring can be prevented. Further, it is possible to provide an insulating layer excellent in adhesion property and ink resistance of printing ink. When the electromagnetic wave shielding sheet of the third embodiment is attached to the FPC, it is possible to provide a printed wiring board provided with an electromagnetic wave shielding sheet having excellent insulation reliability and low repulsive force.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples, which do not limit the scope of the present invention. In the examples, &quot; part (s) &quot; and &quot;% &quot;

[First Embodiment] The conductive fine particles, the binder resin and the epoxy compound used in the examples are shown below.

· Conductive fine particles: composite fine particles (core: copper, coating layer: silver) Average particle diameter D50: 11.0 μm Fukuda metal foil Co., Ltd.

· Binder resin: Thermosetting urethane resin (acid value = 5 mgKOH / g) Toyo Kensha products

· Epoxy compound: bisphenol A type epoxy resin "JER828" (epoxy equivalent = 189 g / eq) Mitsubishi Kagaku Co., Ltd.

· Aziridine compound: "Chemitite PZ-33" manufactured by Nihon Shokuba Co., Ltd.

The black colorants are shown in Table 1-1.

[Table 1-1]

Example 1-1 100 parts of a binder resin, 450 parts of conductive fine particles, 15 parts of an epoxy compound as a curing agent and 2.0 parts of an aziridine compound were put in a container and toluene: isopropyl alcohol (Mass ratio 2: 1) was added and stirred for 10 minutes by a disper to obtain a conductive resin composition. Next, the conductive resin composition was coated on the releasable sheet using a bar code so as to have a dry thickness of 10 mu m and dried in an electric oven at 100 DEG C for 2 minutes to obtain a conductive adhesive layer.

Separately, methyl ethyl ketone was added to 100 parts of the binder resin and 14.8 parts of "RCF / SB200" manufactured by Asahi Carbon Co., Ltd. as a black colorant, and the non-volatile matter concentration was adjusted to 30.0 mass%. The mixture was stirred with a disper, and dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. 3.7 parts of an epoxy resin as a curing agent and 1 part of a quencher "CERAFLOUR 929" (a wax containing polyethylene particles, manufactured by BICKEMISA) were added to 100 parts of the binder resin in the obtained dispersion to obtain a black resin composition. The black resin composition was coated on the surface of the obtained conductive adhesive layer to a dry thickness of 15 μm using a bar coater and dried in an electric oven at 100 ° C. for 3 minutes to obtain an electromagnetic wave shielding sheet. On the insulating layer side, a non-stick releasable sheet was stuck to prevent foreign matters from adhering.

<Examples 1-2 to 1-11, 1-13, 1-14, Reference Example 1-12, Comparative Examples 1-1 to 1-3, 1-5>

An electromagnetic wave shielding sheet was obtained in the same manner as in Example 1-1 except that the kind and blending amount of the raw material of Example 1-1 were changed as shown in Table 1-2. In addition, in Comparative Example 1-2, the black resin composition thickened and geled, so that the insulating property could not be formed by the coating, so that the physical properties were not evaluated.

Example 1-15 100 parts of a binder resin, 75 parts of conductive fine particles, 15 parts of an epoxy compound as a curing agent and 2.0 parts of an aziridine compound were put in a container and toluene: isopropyl alcohol (Mass ratio 2: 1) was added to the mixture, and the mixture was stirred for 10 minutes by a disper to obtain a conductive resin composition. Subsequently, the conductive resin composition was coated on a peelable sheet using a bar coater so as to have a dry thickness of 10 μm, and dried in an electric oven at 100 ° C. for 2 minutes to obtain a conductive adhesive layer. Subsequently, the resulting conductive adhesive layer was applied to one side of an electrolytic copper foil having a thickness of 3 mu m using a laminator.

Separately, methyl ethyl ketone was added to 100 parts of binder resin and 14.8 parts of "RCF / SB00" manufactured by Asahi Carbon Co., Ltd. as a black coloring agent to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. To 100 parts of the binder resin in the obtained dispersion, 3.7 parts of an epoxy resin as a curing agent and 1 part of "CERAFLOUR929" as a quencher were added to obtain a black resin composition. The black resin composition was coated on the electrolytic copper foil side of the laminate of the conductive adhesive layer and the electrolytic copper foil using a bar coater so as to have a dry thickness of 15 μm and dried in an electric oven at 100 ° C. for 3 minutes, . On the insulating layer side, a non-stick releasable sheet was stuck to prevent foreign matters from adhering.

Example 1-16 100 parts of a binder resin, 450 parts of conductive fine particles, 15 parts of an epoxy compound as a curing agent, and 2.0 parts of an aziridine compound were put in a container, and toluene: isopropyl alcohol (Mass ratio 2: 1) was added to the mixture, and the mixture was stirred with a disper for 10 minutes to obtain a conductive resin mixture. Next, the conductive resin composition was coated on a releasable sheet using a bar coater so as to have a dry thickness of 10 μm, and dried in an electric oven at 100 ° C. for 2 minutes to obtain a conductive adhesive layer.

 Separately, methyl ethyl ketone was added to 100 parts of the binder resin and 14.8 parts of "RCF / SB200" to prepare a non-volatile matter concentration of 30.0% by mass. This mixture was stirred with a disperser and then dispersed with a zirconia bead (manufactured by AiJa Co.) to obtain a dispersion. 3.7 parts of an epoxy resin as a curing agent was added to 100 parts of the binder resin in the obtained dispersion to obtain a black resin composition. This black resin composition was applied onto the peelable surface of the peelable sheet (surface roughness Ra of the polyethylene terephthalate film peel treated surface of a thickness of 50 占 퐉 Ra = 0.1 占 퐉) having unevenness on its surface by using a bar coater to obtain a dry thickness of 15 占 퐉 And further dried for 3 minutes in an electric oven at 100 DEG C and then fused with the conductive adhesive layer to obtain an electromagnetic wave shielding sheet.

The surface roughness (Ra) defined in the present invention is defined by JIS-B0601 and was measured with a surface roughness meter, Surfcom 590A (manufactured by Tokyo Kikai Co., Ltd.).

&Lt; Comparative Example 1-4 > 100 parts of a binder resin, 10 parts of an epoxy compound as a curing agent, 10 parts of an aziridine compound and 1 part of a quencher were added and stirred with a disperser. Coated using a bar coater, and dried in an electric oven at 100 ° C for 2 minutes to obtain an insulating layer. Then, the insulating layer was stuck to the conductive adhesive layer formed in the same manner as in Example 1-1 to obtain an electromagnetic wave shielding sheet.

The physical properties were measured according to the following evaluation items. The results are shown in Table 1-2.

&Lt; Preparation of test piece > The obtained electromagnetic wave shielding sheet was prepared to have a width of 60 mm and a length of 60 mm, and then a conductive adhesive layer exposed by peeling the release sheet on the side of the conductive adhesive layer and a polyimide film Quot; Caffe Barrel 500H &quot;) was hot-pressed under the conditions of 150 DEG C, 2 MPa, and 30 minutes. Subsequently, the peelable sheet on the insulating layer side was peeled off and used as a test piece.

&Lt; 85 DEG gloss > The gloss of the surface of the insulating layer of the test piece was measured at an angle of 85 DEG using a micro-TRI-gloss surface gloss meter manufactured by BYK.GARDNER.

&Lt; L * Value Measurement > The L * value of the insulating layer surface of the test piece was measured using "Color Colorimeter CR-400" manufactured by KONICA MINOLTA.

&Lt; Evaluation of visibility of print 1 > Printed on a surface of an insulating layer of a test piece by screen printing using white ink (manufactured by Toyoko Ink). The size of the argument is 1 point. In the dark room, 60W of LED light was irradiated on the printing part, and it was confirmed whether or not the factor could be seen by the eye at a distance of 50cm from the argument at an angle of 20 °, 45 ° and 90 ° based on the horizontal plane. The evaluation criteria are as follows.

◯: Both 20 °, 45 °, and 90 ° are viewable, which is a good result.

?: Can be visually observed at 45 ° and 90 °, practically no problem.

X: No visibility at all angles, practically impossible

&Lt; Evaluation of visibility of print 2 > Printed on a surface of an insulating layer of a test piece by screen printing using white ink (manufactured by Toyoko Ink). The size of the argument is 1 point. In the dark room, 8W of LED light was irradiated on the printing part, and it was confirmed that the factor could be seen by the eye at a distance of 60cm from the factor at an angle of 20 °, 45 ° and 90 ° based on the horizontal plane. The evaluation criteria are as follows.

○: Both 20 °, 45 ° and 90 ° can be seen

△: Visible at 45 ° and 90 °

×: Unable to see from all angles

&Lt; Surface Resistance Value > The surface resistance value of the insulating layer of the test piece was measured using a ring probe URS of "Hirestor UP" manufactured by Mitsubishi Chemical Corporation. The evaluation criteria are as follows.

Good: 1 × 10 ⁸ Ω / □ or more and 1 × 10 ¹⁴ Ω / □ or less.

?: Not less than 1 x 10 ⁵ ? /?, Not more than 1 x 10 ⁸ ? /? Practically no problem.

×: less than 1 × 10 ⁵ Ω / □, or higher than 1 × 10 ¹⁵ Ω / □. Not practicable.

<Wear Resistance> The obtained electromagnetic wave shielding sheet was prepared in a size of 40 mm in width and 150 mm in length. Subsequently, the release sheet was peeled off from the conductive adhesive layer side, and a polyimide film ("CAP Tong 300H" manufactured by Toray DuPont) having a thickness of 75 μm was pressed on the exposed conductive adhesive layer under conditions of 150 ° C., 2 MPa, and 30 minutes. After the compression, the separable sheet on the insulating layer side was removed, and an electromagnetic wave shielding sheet prepared separately for the exposed insulating layer was set. Using a Japan Academic Promotion Wear Tester (product of Testers Ind. Co., Ltd.) Min., And a stroke of 120 mm. The number of reciprocations until the appearance of the insulating layer was observed was measured. The evaluation criteria are as follows.

&Amp; cir &amp;: More than 20,000 times, which is a good result.

?: 10000 times or more and less than 20,000 times, practically no problem.

×: Less than 10,000 times, practically impossible

[Table 1-2]

As a result of evaluating the visibility of the factor 2, the evaluations of Example 1-1 and the like were evaluated as O, whereas the evaluations of all Comparative Examples and Reference Example 1-12 were evaluated as X.

By setting the average primary particle size to 20 to 100 nm as the black colorant and setting the gloss and the L * value within a specific range, the surface resistivity is excellent compared with the case where the requirements are not satisfied, It is possible to demonstrate the possibility.

In addition, excellent results were obtained even when the visibility was further stricter, by setting the content of the black coloring agent to 12.2 to 40 mass% in 100 mass% of the insulating layer in addition to the base material.

[Example 2] The conductive fine particles, thermosetting resin (A1, B1) and curing agents (A2, B2) used in Examples are shown below.

[Conductive filler]

Conductive fine particles: Compound fine particles (core: copper, coating layer: silver) Average particle size D50: 11.0 m Fukuda metal foil Bunko Co., Ltd.)

[Thermosetting resin (A1, B1)]

Thermosetting resin 2-1: Thermosetting polyurethane resin (acid value = 5 mgKOH / g, Tg = 0 占 폚)

Thermosetting resin 2-2: Thermosetting polyamide resin (acid value = 20 mgKOH / g, Tg = 20 캜)

Thermosetting resin 2-3: Thermosetting addition type ester resin (acid value = 10 mgKOH / g, Tg = 10 캜) Toyo Kensha product

Thermosetting resin 2-4: Thermosetting polyester resin (acid value = 10 mgKOH / g, Tg = -10 캜)

[Curing agent (A2, B2)]

Curing agent 2-1: Bisphenol A type epoxy resin "JER828" (epoxy equivalent = 189 g / eq) Mitsubishi Kagaku Co., Ltd.

Curing agent 2-2: aziridine compound "Chemitite PZ-33" manufactured by Nihon Shokubai Co., Ltd.

Surface Conditioner 2-1: Acrylic Polymer Leveling Agent "BYK 350"

Surface Conditioner 2-2: Polyether-modified polydimethylsiloxane leveling agent &quot; BYK 300 &quot;

Surface modifier 2-3: Amide wax &quot; CERAFLOUR 994 (average particle size D50: 5 탆, melting point: 145 캜)

Surface modifier 2-4: Modified polyethylene wax &quot; CERAFLOUR961 &quot; (average particle size D50: 3.5 占 퐉, melting point: 140 占 폚)

Surface modifier 2-5: Polypropylene wax &quot; CERAFLOUR 970 (average particle size D50: 9 탆, melting point: 160 캜)

Surface modifier 2-6: PTFE "CERAFLOUR 981 (average particle size D50: 3 탆)"

Surface Conditioner 2-7: Hydrophobic silica "AEROSIL RY200S" manufactured by EVONIK

Surface Conditioner 2-8: Hydrophilic silica "AEROSIL 130" manufactured by EVONIK

Table 2-1 shows the black colorants.

[Table 2-1]

Example 2-1 (Three-layer structure: insulating layer / metal layer (metal foil) / conductive adhesive layer) 100 parts of thermosetting resin 2-2, 30 parts of conductive fine particles, 30 parts of curing agent 2-1, -2 was put into a two-part container, and a mixed solvent of toluene: isopropyl alcohol (weight ratio 2: 1) was added thereto so that the concentration of nonvolatile matter became 40 mass%, and the mixture was stirred with a disper for 10 minutes to obtain a conductive adhesive. Subsequently, a conductive adhesive agent was applied to a peelable sheet using a bar coater so as to have a dry thickness of 10 μm, and dried in an electric oven at 100 ° C. for 2 minutes to obtain a conductive adhesive layer.

Separately, methyl ethyl ketone was added to 100 parts of the thermosetting resin 2-2, 10 parts of the black coloring agent 2-1 as the black coloring agent, 2 parts of the surface regulating agent 2-8 and 1 part of the surface regulating agent 2-1, The concentration was adjusted to 30.0 mass%. The mixture was mixed with a disper, and dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion solution. To 100 parts of the thermosetting resin (A1) in the obtained dispersion, 30 parts of Curing agent 2-1 and 2 parts of Curing agent 2-2 as curing agents were added and stirred for 10 minutes by a disperator to obtain a black resin mixture. This black resin mixture was coated on the surface of the electrolytic copper foil having the carrier on the side of the electric copper foil using a bar coater so as to have a dry thickness of 10 mu m and dried in an electric oven at 100 DEG C for 3 minutes. Thereafter, a non-stick releasable sheet was stuck on the insulating layer side for preventing the adhesion of foreign matter.

The carrier copper foil was peeled off, and a conductive adhesive layer was applied to the exposed electrolytic copper foil surface to obtain an electromagnetic wave shielding sheet consisting of "unadherently peelable sheet / insulating layer / electrolytic copper foil / conductive adhesive layer / peelable sheet".

&Lt; Examples 2-2 to 25 and Comparative Examples 2-1 to 2-4 > The same procedure as in Example 2-1 was repeated except that the kind and blending amount (parts by mass) of the raw materials in Example 2-1 were changed as shown in Table 2-2 To obtain an electromagnetic wave shielding sheet.

Example 2-26 (Three Layer Composition: Insulating Layer / Metal Layer (Metal Vapor Deposition Layer) / Conductive Adhesive Layer) 100 parts of thermosetting resin 2-2, 30 parts of conductive fine particles, 30 parts of curing agent 2-1, 2-2 were put in a two-part container, and a mixed solvent of toluene: isopropyl alcohol (weight ratio 2: 1) was added thereto so that the concentration of nonvolatile matter became 40 mass%, and the mixture was stirred with a disper for 10 minutes to obtain a conductive adhesive. A conductive adhesive agent was coated on the releasable sheet using a bar coater so as to have a dry thickness of 10 mu m and dried in an electric oven at 100 DEG C for 2 minutes to obtain a conductive adhesive layer.

Separately, 100 parts of the thermosetting resin 2-2, 10 parts of the black coloring agent 2-1 as the black coloring agent, 1 part of the surface regulating agent 2-7 and 1 part of the surface regulating agent 2-1 were added methyl ethyl ketone, The concentration was adjusted to 30.0 mass%. This mixture was mixed with a disper, and then dispersed with a zirconia beads (manufactured by AiJa Co., Ltd.) using a zirconia beads to obtain a dispersion. To 100 parts of the thermosetting resin (A1) in the obtained dispersion, 30 parts of the curing agent 2-1 and 2 parts of the curing agent 2-2 were added as a curing agent, and the mixture was mixed in a disperser for 10 minutes to obtain a black resin mixture. This black resin mixture was coated on the copper deposition surface having a thickness of 0.1 mu m formed on the release surface of the PET film to a dry thickness of 10 mu m using a bar coater and dried in an electric oven at 100 DEG C for 3 minutes. Thereafter, a micro-sticky peelable sheet was stuck to the insulating layer side to prevent foreign matter from adhering to the insulating layer side.

The PET film was peeled off and the conductive adhesive agent (I) was placed on the exposed copper deposition surface to obtain an electromagnetic wave shielding sheet composed of the &quot; unadherently peelable sheet / insulating layer / copper deposition layer / conductive adhesive layer / peelable sheet &quot;.

Examples 2-27 to 29 An electromagnetic wave shielding sheet was obtained in the same manner as in Example 2-1 except that the kind and blending amount (mass part) of the raw materials in Example 2-1 were changed as shown in Table 2-2 .

Example 2-30 (Three Layer Composition: Insulating Layer / Conductive Adhesive Layer (II) / Conductive Adhesive Layer (I)) 100 parts of thermosetting resin 2-2, 30 parts of conductive fine particles, 30 parts of hardener 2-1 And a curing agent 2-2 were put in a two-part container, and a mixed solvent of toluene: isopropyl alcohol (mass ratio 2: 1) was added thereto so that the concentration of the non-volatile component became 40 mass%, and the mixture was stirred in a disper for 10 minutes to obtain a conductive adhesive . Next, a conductive adhesive agent was coated on the releasable sheet using a bar coater so as to have a dry thickness of 10 mu m, and dried in an electric oven at 100 DEG C for 2 minutes to obtain an electrically conductive adhesive layer (I) having anisotropic conductivity.

Separately, 100 parts of the thermosetting resin 2-2, 850 parts of the conductive fine particles, 30 parts of the curing agent 2-1, and 2 parts of the curing agent 2-2 were put in a container and toluene: iso And a mixed solvent of propyl alcohol (2: 1 by mass ratio) were added and mixed by a disper for 10 minutes to obtain a conductive adhesive. Subsequently, a conductive adhesive agent was coated on the peelable sheet using a bar coater so as to have a dry thickness of 3 μm, and dried in an electric oven at 100 ° C. for 2 minutes to obtain a conductive adhesive layer (II) having isotropic conductivity.

100 parts of the thermosetting resin 2-2, 10 parts of the black coloring agent 2-1 as the black coloring agent, 1 part of the surface regulating agent 2-7 and 1 part of the surface regulating agent 2-1 were added and methyl ethyl ketone was added thereto to adjust the non- 30.0% by mass. This mixture was mixed with a disper, and then dispersed with Aiza Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. As a curing agent, 30 parts of the curing agent (1) and 2 parts of the curing agent (2) were added to 100 parts of the thermosetting resin (A1) in the obtained dispersion and stirred with a disperser for 10 minutes to obtain a black resin composition. This black resin composition was coated on a peelable sheet having a surface roughness (Ra) of 0.7 占 퐉 using a bar coater so as to have a dry thickness of 10 占 퐉 and dried in an electric oven at 100 占 폚 for 2 minutes, &Lt; / RTI &gt;

Thereafter, the conductive adhesive layer (II) is stuck to the insulating layer side to peel off the peelable sheet of the conductive adhesive layer (II), and the conductive adhesive layer (I) (II) / conductive adhesive layer (I) / releasable sheet "was obtained.

Example 2-31 (Two-layer construction: insulating layer / conductive adhesive layer (I)) 100 parts of thermosetting resin 2-2, 450 parts of conductive fine particles, 30 parts of curing agent 2-1 and 2 parts of curing agent 2-2 Was added to a 2.0 part container, and a mixed solvent of toluene: isopropyl alcohol (mass ratio 2: 1) was added thereto so that the concentration of the nonvolatile matter became 40 mass%, and the mixture was stirred with a disper for 10 minutes to obtain a conductive adhesive (I). Subsequently, a conductive adhesive agent was coated on the releasable sheet using a bar coater so as to have a dry thickness of 10 mu m, and dried in an electric oven at 100 DEG C for 2 minutes to obtain a conductive adhesive layer.

Separately, methyl ethyl ketone was added to 100 parts of a binder resin, 7 parts of "RCF / SB200" manufactured by Asahi Carbon Co., Ltd. as a black coloring agent, 1 part of a surface modifier 2-7 and 30.1 mass% Lt; / RTI &gt; The mixture was stirred with a disper, and dispersed with i-ka Mill (manufactured by AiGen Co.) using zirconia beads to obtain a dispersion. 30 parts of the curing agent 2-1 and 2 parts of the curing agent 2-2 were added to 100 parts of the binder resin in the obtained dispersion to obtain a black resin composition. This black resin composition was coated on a releasable sheet having a surface roughness (Ra) of 0.7 占 퐉 using a bar coater to a dry thickness of 10 占 퐉 and dried in an electric oven at 100 占 폚 for 3 minutes, To obtain an electromagnetic wave shielding sheet comprising a &quot; peelable sheet / insulating layer / conductive adhesive layer (I) / peelable sheet &quot;.

Physical properties were measured and evaluated according to the following evaluation items. The results are shown in Tables 2-2 to 2-4.

The test piece production method, the 85 ° glossiness, and the L * value were measured in a manner similar to that of the first embodiment. The surface roughness Ra is a value obtained by the same method as in the first embodiment.

&Lt; Water contact angle of insulating layer > The water contact angle of the insulating layer was measured using an automatic contact angle meter DM-501 / analysis software FAMAS manufactured by Kyowa Interface Science Co., Ltd. on the insulating layer surface of the test piece. The measurement method was a droplet method.

<Reflectance Measurement> The reflectance of the insulating layer surface of the test piece was measured using a spectrophotometer (V-570) manufactured by Jasco Co., Ltd.

&Lt; Visibility of printing > The surface of the insulating layer of the test piece was printed by screen printing using white ink (manufactured by Toyo Ink Co.). The size of the argument is 5 points. In the dark room, 60W of LED light was irradiated to the printing part, and it was confirmed that the factor could be seen with an eye at a distance of 50cm from the factor at an angle of 20 °, 45 ° and 90 ° based on the horizontal plane. The evaluation criteria are as follows.

⊚: Both 20 °, 45 ° and 90 ° can be visually observed, which is a very good result.

◯: It is possible to see at 45 ° and 90 °, which is a good result.

?: Visible at 90 °, practically no problem.

X: No visibility at all angles, practically impossible

&Lt; Martens Hardness > The hardness of the insulating layer of the test piece was measured with a Fischer Scope H100C (product of Fisher Instruments) type hardness meter. The measurement was carried out using a Vickers indenter (opening angle: 136 占 diamond quadrangular pyramid) at an immersion depth of 1 占 퐉 and an entry time of 30 seconds in a constant temperature chamber at 25 占 폚. The value obtained by repeatedly measuring 10 surfaces of the same cured film (cured film) surface at random was averaged to obtain a Martens hardness value.

&Lt; Coefficient of Friction Coefficient > The coefficient of dynamic friction of the insulating layer of the test piece was measured by HEIDON (Shindong Scientific Co., Ltd.). The dynamic friction coefficient of the surface of the film was measured by pulling a weight of 100 g supported by three steel balls against the insulating layer of the test piece at a speed of 60 cm / min on the insulating layer. The mean value of the measured values at the other five points was used as the dynamic friction coefficient.

<Insulation reliability> The surface resistance value of the insulating layer of the test piece was measured using a ring probe URS of "Hiresta UP" manufactured by Mitsubishi Chemical Corporation. The evaluation criteria are as follows.

&Amp; cir &amp;: Excellent: 1 x 10 &lt; ⁹ &gt;

Good: 1 × 10 ⁷ Ω / □ or more and less than 1 × 10 ⁹ Ω / □.

?: Not less than 1 x 10 ⁵ ? /? And not more than 1 x 10 ⁷ ? / S, practically no problem.

×: Less than 1 × 10 5 Ω / □, practically impossible.

&Lt; Ink adhesion property > The ink composition was prepared by mixing white silk screen ink SS16 611 (manufactured by Toyokai Co.), cyclohexanone, curing agent SSUR110B (manufactured by Toyokuni Co., Ltd.) at a ratio of 10: And then dried in an oven at 130 ° C. for 10 minutes. A cross-cut test was conducted on the printed surface in accordance with JIS K 5600 to confirm adhesion to the insulating layer of the ink coat.

◎: No peeling in any lattice eyes. Very good results.

○: Small peeling of the coating at the intersection of cuts. Clearly does not exceed 5%. Good results.

B: The coating film is partly and entirely peeled off along the line of the cut. Less than 5% and less than 35%. There is no practical problem.

X: Large peeling occurs on the whole surface. Not practicable.

&Lt; Ink resistance > The test piece was immersed in cyclohexanone for 10 minutes at 25 DEG C and 50% environment. The test piece was taken out and the solvent was removed by air to measure the pencil hardness of the surface of the insulating layer in accordance with JIS K 5600. The evaluation criteria are as follows.

⊚: H Very good result.

Good: F Good results.

DELTA: HB There is no problem in practical use.

X: HB or less, practically inapplicable.

<Reaction force> An electromagnetic wave shielding sheet was prepared in a size of 1 cm in width and 6 cm in length, and used as a sample. The peelable sheet on the side of the conductive adhesive layer (I) was peeled off and the exposed conductive adhesive layer (I) was coated with polyimide ("CAPTON 100H" manufactured by Toray DuPont) having a thickness of 1 cm and a length of 6 cm ° C., 2 MPa, and 30 min. The peelable sheet on the insulating layer side was peeled off and the stiffness value was measured under the test conditions described in JPCA-TMJ002 8.4.1. The results were evaluated according to the following criteria. In addition, when the repulsive force is too high, for example, when the FPC is folded and housed in the electronic device, the signal wiring of the FPC may be burdened and broken.

⊚: repulsive force less than 50 mN / mm. Very good results.

?: Repulsion force of 50 mN / mm or more and less than 100 mN / mm. Good results.

?: Repulsion force of 100 mN / mm or more and less than 150 mN / mm. There is no practical problem.

X: The repulsive force exceeds 150 mN / mm. Not practicable.

[Table 2-2]

[Table 2-3]

[Table 2-4]

From the results of Tables 2-2 to 2-4, it is possible to provide an electromagnetic wave shielding sheet which is excellent in ink film adhesion and ink resistance, excellent in print visibility and repulsive force by the insulating layer of the embodiment, I confirmed that it is possible.

The thermosetting resin (A1, B1, C1), the curing agent (A2, B2, C2), the conductive filler, the photo-curing resin, the initiator and the surface control agent used in the examples are shown below.

[Thermosetting resin (A1, B1, C1)]

Thermosetting resin 3-1: Thermosetting polyurethane resin (acid value = 5 mgKOH / g, Tg = 0 占 폚)

Thermosetting resin 3-2: Thermosetting polyamide resin (acid value = 20 mgKOH / g, Tg = 20 캜)

Thermosetting resin 3-3: Thermosetting addition type ester resin (acid value = 10 mgKOH / g, Tg = 10 캜)

Thermosetting resin 3-4: Thermosetting polyester resin (acid value = 10 mgKOH / g, Tg = -10 캜)

[Curing agent (A2, B2, C2)]

Curing agent 3-1: bisphenol A type epoxy resin &quot; JER828 &quot; (epoxy equivalent = 189 g / eq) manufactured by Mitsubishi Kagaku Co.,

Curing agent 3-2: Aziridine compound "Chemitite PZ-33" manufactured by Nihon Shokubai Co., Ltd.

[Monomer]

DPHA: dipentaerythritol hexaacrylate

[Photocurable resin]

Photocurable resin 3-1: Urethane aclite resin "UV6300B" (molecular weight Mw = 3700) Nippon Kosaka Chemical Co., Ltd.

[Initiator]

Initiator 3-1: 1-Hydroxy-cyclohexyl-phenyl-ketone

[Surface Conditioning Agent]

Surface modifier 3-1: Amide wax &quot; CERAFLOUR 994 (average particle size D50: 5 탆, melting point: 145 캜) &quot;

Surface modifier 3-2: Modified polyethylene wax "CERAFLOUR961 (average particle diameter D50: 3.5 탆, melting point: 140)"

Surface Conditioner 3-3: Acrylic Polymer Leveling Agent "BYK350"

Surface Conditioner 3-4: Polyether-modified polydimethylsiloxane leveling agent &quot; BYK300 &quot;

Surface modifier 3-5: Polypropylene wax &quot; CERAFLOUR 970 &quot; (average particle size D50: 9 탆, melting point: 160 캜)

Surface Conditioner 3-6: PTFE "CERAFLOUR 981 (average particle size D50: 3 μm)"

Surface Conditioner 3-7: Hydrophobic silica "AEROSIL RY200S" manufactured by EVONIK

Surface Conditioner 3-8: Hydrophilic silica "AEROSIL 130" manufactured by EVONIK

[Conductive filler]

Conductive Fine Particles 3-1: Composite fine particles (fine particles of tungsten oxide coated with 10 parts by mass of silver relative to 100 parts by mass of copper in the core) Average particle size D50: 11.0 mu m Fukuda Metal Bamboo Industrial Co., Ltd.

As the black colorant, a colorant as shown in Table 2-1 of the second embodiment was used.

<Example 3-1> (Four-layer structure: insulating layer (also referred to as insulating transparent resin layer) / black layer / metal layer (electrolytic copper foil) / conductive adhesive layer (I)

100 parts of the thermosetting resin 3-2, 30 parts of the conductive fine particles 3-1, 30 parts of the curing agent 3-1, and 2 parts of the curing agent 3-2 were put in a container, and toluene: And a mixed solvent of isopropyl alcohol (weight ratio 2: 1) was added and stirred for 10 minutes by a disper to obtain a conductive adhesive. Subsequently, a conductive adhesive agent was coated on the peelable sheet using a bar coater so as to have a dry thickness of 10 μm, and dried in an electric oven at 100 ° C. for 2 minutes to obtain a conductive adhesive layer (I).

Separately, methyl ethyl ketone was added to 20 parts of thermosetting resin 3-3, 1 part of surface modifier 3-1 and 2 parts of surface modifier 3-8 to prepare a non-volatile matter concentration of 30.0% by mass. This mixture was mixed with a disper, and then dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. To 20 parts of the thermosetting resin (A1) in the obtained dispersion, 75 parts of the photocurable resin 3-1, 5 parts of dipentaerythritol hexaacrylate (DPHA) as a monomer and 5 parts of the initiator 3-1 were added, Followed by stirring for 10 minutes to obtain a transparent resin mixture. This transparent resin mixture was coated on the release surface of the transparent release sheet to a dry thickness of 4 탆 using a bar coater and dried in an electric oven at 100 캜 for 3 minutes to irradiate ultraviolet rays under the condition of coating 30 mJ / And then cured to obtain an insulating layer.

The spectral transmittance of the insulating layer measured using the spectrophotometer at this time was 70% or more in the entire wavelength range of 400 nm to 700 nm.

Separately, 100 parts of thermosetting resin 3-3 and 10 parts of black coloring agent 2-1 as a black coloring agent were added to methyl ethyl ketone to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and then dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion solution. To 100 parts of the thermosetting resin (B1) in the obtained dispersion, 30 parts of the curing agent 3-1 as a curing agent and 2 parts of the curing agent 3-2 were added and stirred for 10 minutes by a disperper to obtain a black resin composition. The black resin composition was coated on the surface of the electrolytic copper foil having the carrier on the electrolytic copper foil side using a bar coater so as to have a dry thickness of 3 μm and dried in an electric oven at 100 ° C. for 3 minutes to form a black layer.

The copper foil of the carrier was peeled off to bond the conductive adhesive agent (I) to the exposed electrolytic copper foil surface, and then an insulating layer was adhered to the surface of the black layer to form a &quot; peelable sheet / insulating layer / black layer / metal layer (electrolytic copper foil) Layer (I) / releasable sheet &quot;.

<Examples 3-2 to 3-25 and Comparative Examples 3-1 to 3-4> Except that the kind and amount (mass part) of the raw materials of Example 3-1 were changed as shown in Tables 3-1 to 3-4 The electromagnetic wave shielding sheet was obtained in the same manner as in Example 3-1.

&Lt; Example 3-26 > (Four-layer structure: insulating layer / black layer / metal layer (metal deposition layer) / conductive adhesive layer (I)

100 parts of the thermosetting resin 3-2, 30 parts of the conductive fine particles 3-1, 30 parts of the curing agent 3-1, and 2 parts of the curing agent 3-2 were put into a container, and toluene: iso Propyl alcohol (weight ratio 2: 1) was added and stirred for 10 minutes by a disper to obtain a conductive adhesive. Subsequently, a conductive adhesive agent was coated on the releasable sheet using a bar coater so as to have a dry thickness of 10 mu m, and dried in an electric oven at 100 DEG C for 2 minutes to obtain a conductive adhesive layer (I).

Separately, methyl ethyl ketone was added to 20 parts of thermosetting resin 3-3, 1 part of surface modifier 3-3, and 1 part of surface modifier 3-7 to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. 75 parts of the photo-curable resin 3-1, 5 parts of dipentaerythritol hexaacrylate (DPHA) as a monomer and 5 parts of the initiator 3-1 were added to 20 parts of the thermosetting resin (A1) in the obtained dispersion, Followed by stirring for 10 minutes to obtain a transparent resin composition. This transparent resin composition was coated on the cleansing surface of the transparent peelable sheet so as to have a dry thickness of 4 μm using a bar coater and dried in an electric oven at 100 ° C. for 3 minutes and irradiated with ultraviolet rays under conditions of coating 30 mJ / And then cured to obtain an insulating layer.

The spectral transmittance of the insulating layer, which is the insulating transparent resin layer measured using the spectrophotometer at this time, was 70% or more in the entire wavelength range of 400 nm to 700 nm.

Separately, 100 parts of thermosetting resin 3-3 and 10 parts of black coloring agent 2-1 as a black coloring agent were added with methyl ethyl ketone to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and dispersed with iodine mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. To 100 parts of the thermosetting resin (B1) in the obtained dispersion, 30 parts of the curing agent 3-1 and 2 parts of the curing agent 3-2 as a curing agent were added and stirred for 10 minutes by a disperser to obtain a black resin composition. This black resin composition was coated on the copper deposition surface having a thickness of 0.1 mu m formed on the release surface of the PET film to a dry thickness of 3 mu m using a bar coater and dried in an electric oven at 100 DEG C for 3 minutes, Layer.

The insulating layer was stuck to the surface of the black layer, the PET film of the copper deposition was peeled off, and the conductive adhesive agent (I) was applied to the exposed copper deposition surface to form a &quot; peelable sheet / insulating layer / black layer / metal layer Layer / conductive adhesive layer (I) / releasable sheet "was obtained.

&Lt; Examples 3-27 to 3-29 > The same procedures as in Example 3-26 were carried out except that the kinds and blend amounts (parts by mass) of the raw materials of Examples 3-26 were changed as shown in Tables 3-2 to 5, A shielding sheet was obtained.

&Lt; Example 3-30 > (Four-Layer Composition: Insulating Layer / Black Layer / Conductive Adhesive Layer (II) / Conductive Adhesive Layer (I)

100 parts of the thermosetting resin 3-2, 30 parts of the conductive fine particles 3-1, 30 parts of the curing agent 3-1, and 2 parts of the curing agent 3-2 were put in a container, and toluene: And a mixed solvent of isopropyl alcohol (weight ratio 2: 1) was further added, followed by stirring for 10 minutes with a disper to obtain a conductive adhesive. Subsequently, a conductive adhesive agent was applied on the releasable sheet using a bar coater so as to have a dry thickness of 10 mu m, and dried in an electric oven at 100 DEG C for 2 minutes to obtain an electrically conductive adhesive layer (I) having anisotropic conductivity.

Separately, methyl ethyl ketone was added to 20 parts of thermosetting resin 3-3, 1 part of surface modifier 3-3, and 1 part of surface modifier 3-7 to prepare a non-volatile matter concentration of 30.0% by mass. This mixture was stirred with a disperser and then dispersed with ijima mill (manufactured by AiJa Co.) using zirukonia beads to obtain a dispersion. To 20 parts of the thermosetting resin (A1) in the obtained dispersion, 75 parts of the photocurable resin 3-1, 5 parts of dipentaerythritol hexaacrylate (DPHA) as a monomer, and 5 parts of initiator 3-1 were added, The mixture was stirred for 10 minutes to obtain a transparent resin mixture. This transparent resin mixture was coated on the release surface of the transparent release sheet to a dry thickness of 4 占 퐉 using a bar coater and dried in an electric oven at 100 占 폚 for 3 minutes and exposed to ultraviolet rays under an exposure dose of 30 mJ / And irradiated and cured to obtain an insulating layer.

The spectral transmittance of the insulating layer measured using the spectrophotometer at this time was 70% or more in the entire wavelength range of 400 nm to 700 nm.

Separately, 100 parts of thermosetting resin 3-3 and 10 parts of black coloring agent 2-1 as a black coloring agent were added to methyl ethyl ketone to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and dispersed with iodine mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. To 100 parts of the thermosetting resin (B1) in the obtained dispersion, 30 parts of Curing Agent 3-1 and 2 parts of Curing Agent 3-2 as a curing agent were added and stirred for 10 minutes by a disperator to obtain a black resin composition. Coated with a bar coater to a dry thickness of 3 占 퐉, and dried in an electric oven at 100 占 폚 for 3 minutes to form a black layer.

Separately, 100 parts of the thermosetting resin 3-1, 850 parts of the conductive fine particles 3-1, 30 parts of the hardening agent 3-1, and 2 parts of the hardening agent 3-2 were put in a container and the concentration of the nonvolatile matter was adjusted to 40 mass% A mixed solvent of toluene and isopropyl alcohol (weight ratio 2: 1) was added and stirred with a disper for 10 minutes to obtain a conductive adhesive. Subsequently, a conductive adhesive agent was coated on the releasable sheet using a bar coater so as to have a dry thickness of 3 탆 m, and dried in an electric oven at 100 캜 for 2 minutes to obtain a conductive adhesive layer (II) having isotropic conductivity.

The conductive adhesive layer (I) and the conductive adhesive layer (II) were laminated so that the peelable sheet of the conductive adhesive layer (II) was peeled off and the black layer and the insulating layer were laminated, (II) / conductive adhesive layer (I) / releasable sheet &quot; was obtained.

<Example 3-31> (Three Layer Composition: Insulating Layer / Black Layer / Conductive Adhesive Layer (I))

100 parts of the thermosetting resin 3-2, 450 parts of the conductive fine particles 3-1, 30 parts of the curing agent 3-1 and 2.0 parts of the curing agent 3-2 were put in a container, and toluene: And a mixed solvent of isopropyl alcohol (weight ratio 2: 1) was added and stirred for 10 minutes by a disper to obtain a conductive adhesive (I). Subsequently, a conductive adhesive agent was coated on the releasable sheet using a bar coater so as to have a dry thickness of 10 mu m, and dried in an electric oven at 100 DEG C for 2 minutes to obtain a conductive adhesive layer (I).

Separately, 20 parts of thermosetting resin 3-3, 1 part of surface modifier 3-3 and 1 part of surface modifier 3-7 were added to methyl ethyl ketone to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and dispersed with iodine mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. 75 parts of the photocurable resin 3-1, 5 parts of dipentaerythritol hexaacrylate (DPHA) as a monomer and 5 parts of initiator 3-1 were added to 20 parts of the thermosetting resin (A1) in the obtained dispersion, Followed by stirring for 10 minutes to obtain a transparent resin composition. This transparent resin composition was coated on the transparent release surface of the peelable film to a dry thickness of 4 탆 using a bar coater and dried in an electric oven at 100 캜 for 3 minutes to irradiate ultraviolet rays under an exposure dose of 30 mJ / And then cured to obtain an insulating layer.

The spectral transmittance of the insulating layer measured using the spectrophotometer at this time was 70% or more in the entire wavelength range of 400 nm to 700 nm.

Separately, 100 parts of thermosetting resin 3-3 and 10 parts of black coloring agent 2-1 as a black coloring agent were added to methyl ethyl ketone to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and then dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion solution. To 100 parts of the thermosetting resin (B1) in the obtained dispersion, 30 parts of the curing agent 3-1 as a curing agent and 2 parts of the curing agent 3-2 were added and stirred for 10 minutes by a disperper to obtain a black resin composition. Coated with a bar coater to a dry thickness of 3 占 퐉, and dried in an electric oven at 100 占 폚 for 3 minutes to form a black layer.

A black layer and an insulating layer were stuck to the conductive adhesive layer (I) to obtain an electromagnetic wave shielding sheet comprising a &quot; peelable sheet / insulating layer / black layer / conductive adhesive layer (I) / peelable sheet &quot;.

[Example 3-32] (Four-layer structure: insulating layer / black layer / metal layer (electrolytic copper foil) / conductive adhesive layer (I)) [

100 parts of the thermosetting resin 3-2, 30 parts of the conductive fine particles 3-1, 30 parts of the curing agent 3-1, and 2 parts of the curing agent 3-2 were put in a container, and toluene: And a mixed solvent of isopropyl alcohol (weight ratio 2: 1) was further added, followed by stirring for 10 minutes with a disper to obtain a conductive adhesive. Subsequently, a conductive adhesive agent was coated on the peelable sheet using a bar coater so as to have a dry thickness of 10 mu m, and further dried in an electric oven at 100 DEG C for 2 minutes to obtain a conductive adhesive layer (I).

Separately, methyl ethyl ketone was added to 100 parts of the thermosetting resin 3-1, 1 part of the surface modifier 3-3 and 1 part of the surface modifier 3-7 to prepare a non-volatile matter concentration of 30.0% by mass. The mixture was stirred with a disper, and dispersed with iodine mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. 10 parts of the curing agent 3-1 and 0.5 parts of the curing agent 3-2 were added to 100 parts of the thermosetting resin (A1) in the obtained dispersion, and the mixture was stirred in a disperser for 10 minutes to obtain a transparent resin composition. This transparent resin composition was coated on the release surface of the transparent release sheet so as to have a dry thickness of 4 탆 using a bar coater and dried in an electric oven at 100 캜 for 3 minutes to obtain an insulating transparent resin layer.

The spectral transmittance of the transparent resin layer measured using the spectrophotometer at this time was 70% or more in the entire wavelength range of 400 nm to 700 nm.

Separately, 100 parts of thermosetting resin 3-3 and 10 parts of black coloring agent 2-1 as a black coloring agent were added with methyl ethyl ketone to prepare a non-volatile matter concentration of 30.0% by mass. This mixture was stirred in a disper and then dispersed with i-ka Mill (manufactured by AiJa Co.) using zirconia beads to obtain a dispersion. To 100 parts of the thermosetting resin (B1) in the obtained dispersion, 30 parts of Curing Agent 3-1 and 2 parts of Curing Agent 3-2 as a curing agent were added and stirred for 10 minutes by a disperator to obtain a black resin composition. This black resin composition was coated on the surface of the electrolytic copper foil having the carrier on the electrolytic copper foil side using a bar coater so as to have a dry thickness of 3 μm and dried in an electric oven at 100 ° C. for 3 minutes to form a black layer.

The copper foil of the carrier is peeled off, the conductive adhesive agent (I) is applied to the exposed electrolytic copper foil surface, and an insulating layer which is an insulating transparent resin layer is stuck to the surface of the black layer to form the &quot; peelable sheet / insulating layer / black layer / metal layer Electroconductive copper foil) / conductive adhesive layer (I) / releasable sheet &quot;.

Examples 3-33 to 3-34 The same procedures as in Example 3-32 were carried out except that the kinds and blend amounts (parts by mass) of the raw materials in Examples 3-32 were changed as in Tables 3-1 to 3-4, A shielding sheet was obtained.

[Table 3-1]

[Table 3-2]

[Table 3-3]

[Table 3-4]

The properties were measured and evaluated according to the following evaluation items. The results are shown in Tables 3-5 and 3-6.

The test piece production, the 85 ° glossiness, and the L * value were measured in the same manner as in Example 1 and evaluated on the same basis. Further, the water contact angle and the reflectance of the insulating layer, the measurement of the reflectance, the hardness of the pattern, the coefficient of motion friction, the visibility of the print, the ink adhesion, the ink resistance, the insulation reliability and the repulsive force were evaluated in the same manner as in the second embodiment.

[Table 3-5]

[Table 3-6]

From the results of Tables 3-5 and 3-6, the electromagnetic wave shielding sheet according to the third embodiment in which the insulating layer, the black layer, and the conductive adhesive layer (I) in this order are stacked in this order has a contact angle with water on the surface of the insulating layer 60 to 110 °, which is good in ink adhesion and ink resistance and is excellent in print visibility. In addition, an electromagnetic wave shielding sheet having a low repulsion and a good production rate and capable of reducing the manufacturing cost was obtained.

The electromagnetic wave shielding sheet of the present invention can be used for various purposes in which it is necessary to shield electromagnetic waves. For example, not only rigid printed wiring boards but also flexible printed wiring boards, COFs, TABs, flexible connectors, liquid crystal displays, touch panels and the like can be used. In addition, it can be used as a construction material such as a computer case, a building material wall and a window, and a member shielding electromagnetic waves such as vehicles, ships, and aircraft.

One; Insulating layer
2; The conductive adhesive layer
3; Conductive layer
4; Electromagnetic wave shielding sheet
5; Black layer
6; Cover coat layer
7; Insulating substrate
8; Print wiring
9; Wiring circuit
10; Printed circuit board
11; Hole (contact hole)

Claims (13)

In an electromagnetic wave shielding sheet containing a black coloring agent,
At least an insulating layer, and a conductive adhesive layer,
Wherein the insulating layer is formed of a black resin composition containing a thermosetting resin, a curing agent and the black coloring agent and has an 85 ° gloss of 15 to 50 and an L * value in an L * a * b * 30,
Wherein the black coloring agent has an average primary particle diameter of 20 to 100 nm and a content of the black coloring agent in an amount of 12.2 to 40 mass% of 100 mass% of the insulating layer.
The method according to claim 1,
Wherein the insulating layer has a surface resistance value of 1 x 10 &lt; ⁵ &gt; to 1 x 10 &lt; ¹⁴ &gt; The method according to claim 1,
Wherein the conductive adhesive layer is formed of a conductive adhesive composition containing a thermosetting resin, a curing agent, and a conductive filler. The method according to claim 1,
The conductive adhesive layer is an anisotropic conductive adhesive layer,
And an isotropic conductive layer formed on the surface of the electromagnetic wave shielding sheet. The method according to claim 1,
And a metal thin film layer between the insulating layer and the conductive adhesive layer. The method according to claim 1,
(Printed) on the surface of the insulating layer.
delete delete delete A printed wiring board comprising the electromagnetic wave shielding sheet according to any one of claims 1 to 6, a cover coat layer, a signal wiring and a wiring board comprising an insulating substrate. 11. The method of claim 10,
And printed on the insulating layer provided on the electromagnetic wave shielding sheet. 12. The method of claim 11,
Wherein the factor is white. 11. An electronic apparatus having the printed wiring board according to claim 10.

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