JP2011171474A - Electromagnetic wave shielding material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid an adverse influence on product quality even if the line width of a conductive convex pattern layer formed by a draw-out primer intaglio printing method becomes thick when its printing speed is made extremely high in order to make the electromagnetic wave shielding performance highly compatible with light permeability of an electromagnetic wave shielding material. <P>SOLUTION: With regard to the electromagnetic wave shielding material 10 in which conductive convex pattern layers 3 are accumulated, the conductive convex pattern layers including conductive particles and binder resin on a transparent substrate 1 through a primer layer 2 having many openings 4 formed in the non-formation area where the primer layer is thicker in the formation area compared to the non-formation area of the conductive convex pattern layer in at least one of the two parallel striated groups in which the conductive convex pattern layers cross each other, the line width W becomes thick by a leaking part 5 and the main convex cross-sectional shape are different at both sides of the summit that the widths at the base from the summit to the primer layer surface, and a relation (Ww-Wn)/2Wn between the width Ww of wider base and the width Wn of a narrower base is set to be 0.5 or smaller. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electromagnetic wave shielding material suitable for use in various applications, particularly in front of a display. In particular, the present invention relates to an electromagnetic wave shielding material that suppresses deterioration in pattern accuracy of a conductive convex pattern layer at the time of printing speedup and prevents an influence on product quality.

  Currently, as a display (also referred to as an image display device), a liquid crystal display (LCD), a plasma display panel (hereinafter also referred to as PDP), an electroluminescence (hereinafter referred to as a PDP), a flat panel display (FPD), in addition to a conventional cathode ray tube (CRT) display. Various displays such as EL) displays are in practical use. Among these, in particular, since PDP has strong emission of unnecessary electromagnetic waves, an electromagnetic wave shielding material is disposed on the front surface (observer side surface) of the display.

  In addition, the electromagnetic wave shielding material for display applications is highly opaque as a result of a highly conductive metal layer, such as a metal layer having excellent conductivity, in that it can achieve both excellent electromagnetic wave shielding performance and excellent light transmittance for visible light. In order to ensure light transmission even with an opaque conductor layer, the conductor layer is formed as a conductor pattern layer having a large number of openings in a pattern such as a mesh shape. ing. For forming the conductor pattern layer, there is a method of forming a metal foil by a photoetching method, but a printing method is advantageous in terms of cost. Various electromagnetic shielding materials using a printing method for forming the conductor pattern layer have been proposed. In the specification of the present application, “electromagnetic wave” means an electromagnetic wave in a broad sense, particularly a frequency band centered on the kHz to GHz band (so-called radio wave). Higher frequency infrared rays, visible rays, ultraviolet rays, etc. are referred to as infrared rays, visible rays, ultraviolet rays, etc., respectively.

  In addition, among the printing methods, it is possible to form fine patterns with fine line widths that were not possible in the past, and highly compatible with excellent electromagnetic wave shielding and excellent light transmittance. There is an intaglio printing method proposed by a person (Patent Document 1). The intaglio printing method disclosed in Patent Document 1 is a method of intaglio printing an ink of a conductive composition on a primer fluidized bed in a fluid state applied on a transparent substrate, and in that case, a transparent on the plate surface While the base material is present, the primer fluidized layer between the plate surface and the transparent base material is solidified by ultraviolet irradiation or the like to form a primer layer, and then the transparent base material is released from the intaglio plate on the transparent base material. In this method, a conductive convex pattern layer obtained by solidifying a conductive composition as a conductor pattern layer through a primer layer is printed. When the primer layer is in a fluid state, the primer layer promotes the transfer of ink from the printing plate to the printing material, in other words, draws out the ink filled in the concave portion of the intaglio plate surface and transfers it to the printing material (transparent substrate). This intaglio printing method is a printing method that can be called the “pulling primer type intaglio printing method”.

Pamphlet of International Publication No. 2008/149969

  However, the “pulling primer type intaglio printing method” disclosed in Patent Document 1 can form a thin and fine pattern, which was impossible in the past, but it is similar to a general printing method. As printing speed is increased, pattern accuracy deteriorates. Of course, in order to achieve mass productivity and cost reduction, it is preferable that the printing speed is high as long as the pattern accuracy is allowed. The deterioration of pattern accuracy when printing speed is increased is that the ink of the conductive composition is supplied to the rotating intaglio plate surface using a cylinder-shaped (cylindrical) intaglio plate, and then unnecessary ink on the plate-surface convex portion with a doctor blade. This is because the anisotropy of the ink scraping property when scraping off becomes apparent.

  This will be described with reference to the conceptual diagram of FIG. In the perspective view of FIG. 3A, the intaglio 31 that rotates in a cylinder shape (cylindrical shape) is formed with a recess 32 made of a groove pattern corresponding to the conductive convex pattern layer printed on the plate surface. . Then, the ink 34 made of the conductive composition stored in the ink pan 33 is supplied to the plate surface of the intaglio 31. The surplus portion of the ink 34 supplied to the printing plate is scraped off by the doctor blade 35, and the intaglio printing is performed by transferring the ink 34 filled in the concave portion 32 to the printing object (transparent substrate). The scraping direction Xd of the doctor blade 35 is opposite to the rotation direction Xp of the cylinder-shaped intaglio 31. That is, here, the scraping direction Xd of the doctor blade 35 is defined as a relative movement direction of the doctor blade 35 with respect to the plate surface (an imaginary observer fixed on the plate surface). In reality, the doctor blade 35 is fixed in the circumferential direction of the intaglio 31 and the intaglio 31 rotates. In the figure, the groove pattern of the concave portion 32 on the plate surface is composed of two groups of parallel line stripes intersecting at right angles with each other in a square lattice mesh pattern, and the rotational direction Xp (circumferential direction) of the intaglio plate 31 On the other hand, the direction in which the line of one of the two groups of parallel lines extends is parallel, and the direction in which the line of the other parallel line group extends has a right angle relationship.

  3B, when the scraping direction Xd of the doctor blade 35 is the positive direction of the X axis and the direction orthogonal to the scraping direction Xd on the printing plate is the Y axis, The direction in which the groove of the concave portion 32 extends is parallel to the Y axis, in other words, the groove of the parallel line group arranged in the X axis direction, conceptually showing the ink scraping situation of the doctor blade 35. It is. When the printing speed is increased, after the unnecessary ink 34 on the plate surface convex portion is scraped off by the doctor blade 35, the plate surface convex portion located downstream in the scraping direction Xd of the doctor blade 35 of the concave portion 32. On top of this, the leaked portion 5 where the ink 34 remains on the plate surface convex portion is generated, as the ink 34 filled in the concave portion 32 protrudes. As a result, the ink of the leaking part 5 is also printed, and the line width is increased by the amount of the leaking part 5 on the printed matter.

On the other hand, when the extending direction of the groove of the concave portion 32 is a groove parallel to the X axis, the groove corresponding to the concave portion 32 continues to exist on the downstream side in the scraping direction Xd of the doctor blade 35 of the concave portion 32, and leakage occurs. Since there is no plate surface convex portion itself where the portion 5 is generated, the leakage portion 5 is not generated.
For this reason, if the groove pattern of the concave portion 32 has an X-axis direction and a Y-axis direction in the extending direction of the groove, the groove width of the concave portion 32 on the plate surface is the same in the X-axis direction and the Y-axis direction. Even in the case of the line width of the conductive convex pattern layer actually printed and formed, the line width extending in the direction orthogonal to the X-axis direction (Y-axis direction) is the line width in the X-axis direction ( It is expanded in the positive direction of the scraping direction Xd) and the line width is increased. On the other hand, the line width extending in the direction orthogonal to the Y-axis direction (X-axis direction) is not thick. Therefore, anisotropy with different line widths occurs between the X-axis direction and the Y-axis direction.
Further, in the electromagnetic wave shielding material using the “pulling primer type intaglio printing method”, the printing is performed on the surface of the primer layer (flowing layer) in a fluid state, and therefore the primer layer 2 in which the conductive composition of the leaking portion 5 is solidified. It becomes a shape that is embedded (embedded) from the surface inside {see FIG. 1 (a)}.

  And in the inside of the leaking part 5 on the printed matter, the electrical contact between the conductive particles tends to be lowered and insufficient as compared with the part other than the leaking part. The contribution of the pattern layer to the electrical conductivity (surface resistivity) is small compared to other parts, while the leakage portion 5 that has entered the openings 4 of the mesh pattern reduces the light transmittance of visible light { See FIG. 1 (a)}. Therefore, it cannot be said that it is a preferable part from the viewpoint of achieving both high electromagnetic shielding performance and light transmittance.

  Further, when the conductive convex pattern layer 3 to be printed has a line width that is different between two different groups extending in two directions in a lattice shape such as a square lattice, the observation is performed when the electromagnetic wave shielding material is disposed on the front surface of the display. The uniformity of the image quality of the display is reduced, which is not preferable in terms of product quality.

  That is, the object of the present invention is to provide an electromagnetic shielding material suitable for use in the front surface (observer side surface) of various displays such as PDPs, in order to achieve both high electromagnetic shielding performance and light transmittance. Effectiveness of electrical conductivity and light transmittance due to the leaking part that occurs when the printing speed is increased to the line width of the line (line part) that is the formation part of the conductive convex pattern layer formed by the “system intaglio printing method” An object of the present invention is to provide an electromagnetic wave shielding material that prevents a reduction in image quality uniformity due to a decrease in line width anisotropy from affecting the product quality.

Therefore, the electromagnetic wave shielding material of the present invention has the following configuration.
(1) A conductive convex pattern layer containing conductive particles and a binder resin is formed as a conductor pattern layer on a transparent substrate via a primer layer, and many non-formed portions of the conductive convex pattern layer are formed. In the electromagnetic wave shielding material, the primer layer is thicker at the conductive convex pattern layer forming portion than at the non-formed portion of the conductive convex pattern layer.
The conductive convex pattern layer has at least one group of two groups of parallel lines intersecting each other, and the main cut surface shape of the convex part, which is the formation part of the conductive convex pattern layer, is from the top on both sides of the top. When the width of the collar part up to the primer layer surface is different, the width of the wide collar part is Ww, and the width of the narrow collar part is Wn, (Ww−Wn) / 2Wn is 0.5 or less. Electromagnetic wave shielding material.
(2) Furthermore, in the above configuration, the distribution of the conductive particles in the convex portions of the conductive convex pattern layer is relatively sparse in the vicinity of the primer layer and dense in the vicinity of the top portion. Material.

(1) According to the present invention, even if anisotropy having a different line width occurs due to the presence of the leaking portion between the two groups of parallel lines that intersect with each other constituting the conductive convex pattern layer, Paying attention to the left-right asymmetry of the width of the buttock in the shape of the main cut surface (cross section orthogonal to the extending direction) as described above, the width of the ridge is regulated and controlled so that the conductive convex shape The adverse effect on the conductivity and light transmittance of the pattern layer and the adverse effect on the uniformity of the image quality of the display image due to the anisotropy of the line width can be suppressed to prevent the product quality from deteriorating.
(2) Further, by providing the distribution of the conductive particles within the convex portions of the conductive convex pattern layer with a predetermined roughness, the entire conductive convex pattern layer can be used even with the same amount of conductive particles used. The surface resistivity can be lowered to achieve both higher electromagnetic shielding performance and light transmittance, and the adhesion between the conductive convex pattern layer and the primer layer can be enhanced.

It is explanatory drawing which illustrates one form of the electromagnetic wave shielding material of this invention, (a) is sectional drawing, (b) is a top view, (c) is sectional drawing of a part without a leakage part. As one form of the convex part (formation part) of the conductive convex pattern layer by the drawing primer type intaglio printing method, the primer layer is thicker in the formation part than the non-formation part of the conductive convex pattern layer, and the conductive convex pattern Sectional drawing which shows notionally the distribution of the electroconductive particle in the convex part of a layer that the top part of a convex part is dense, and the primer layer vicinity is a sparse form. (B) is a perspective view for explaining the relationship between the groove pattern of the concave portion on the cylinder-shaped intaglio and the doctor blade; ) Is a cross-sectional view for explaining ink leakage at the time of scraping of the doctor blade, which causes the leakage portion.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Example Embodiment]
First, an embodiment of the electromagnetic wave shielding material of the present invention will be described with reference to a cross-sectional view of FIG. 1A, a plan view of FIG. 1B, and a cross-sectional view of FIG. As shown in the figure, in the electromagnetic wave shielding material 10 of the present invention, a primer layer 2 is formed on at least one surface of a transparent substrate 1, and conductive particles and a binder resin are formed on the primer layer 2 as a conductor pattern layer. The conductive convex pattern layer 3 is formed as a solidified product of the conductive composition containing, and a large number of openings 4 for ensuring light transmission are formed as non-formed portions of the conductive convex pattern layer 3. Has been. Further, in the present embodiment example, the plan view shape of the conductive convex pattern layer 3 is a square lattice mesh shape, as shown in FIG. 1B, arranged parallel to each other in the X-axis direction and the X-axis. A line Lx that extends linearly in a direction orthogonal to the direction and a line Ly that is arranged parallel to each other in the Y-axis direction and linearly extends in a direction orthogonal to the Y-axis direction intersect each other at right angles It is a pattern.

Moreover, in the line Lx, as conceptually shown in the cross-sectional view of FIG. 1A, the widths of the flanges on both sides of the top P are asymmetrically different (in the drawing, the right side of the top is wider than the left side). In addition, the top part P is a top part with the highest altitude, and is a part at a position farthest in the vertical direction from the surface of the transparent substrate 1. In addition, the width of the ridge portion means that, in the conductive convex pattern layer 3, the virtual normal N passing through the top portion P and orthogonal to the transparent substrate 1 and the skirt (麓) of the conductive convex pattern layer 3. The distance between the front ends En and Ew in the direction orthogonal to the normal N (in the direction parallel to the transparent substrate 1). On the other hand, the line Ly is conceptually shown in the cross-sectional view of FIG. 1 (c), and the tip portions En and En of the ridges on both sides of the top P are equidistant from the normal N passing through the top. The width of both ridges is Wn, and the shape of the main cut surface of the convex pattern layer 3 is symmetrical with respect to the normal line N. For this reason, the double 2Wn is the line width W of the line Ly and is Wy (however, this is not the case when the cross-sectional shape of the concave portion of the intaglio plate surface is not a symmetrical shape).
Therefore, in this embodiment, as conceptually shown in the plan view of FIG. 1B, the line width of the line Lx is wider than the line Ly that is orthogonal to the line Lx. Specifically, the line width Wx of the line Lx is 15 μm, the line width Wy of the line Ly is 14 μm, and the arrangement period of the line Lx and the line Ly is the same and 300 μm.

  In the present embodiment, a transparent polyethylene terephthalate film having a thickness of 100 μm is used for the transparent substrate 1, and the conductive convex pattern layer 3 is made of silver conductive particles, a polyester resin, a solvent, and the like. A conductive composition (ink) made of a resin binder is formed by printing by the “pulling primer type intaglio printing method”. The primer layer 2 was formed on the transparent substrate 1 to be a 7 μm-thick primer layer using an acrylate-based ultraviolet curable resin primer.

However, in this embodiment, although the line width Wx of the line Lx is wider than the line width Wy of the line Ly, the width of the ridges on both sides of the top is asymmetrical within the predetermined dimension range for the line Lx. Therefore, the product quality has not been lowered so as to adversely affect the uniformity of the image quality of the display image. Further, in order to ensure a desired electromagnetic wave shielding property in the portion of (Ww + Wn) −ΔW = 2Wn (and the width Wy portion of the filament Ly) in the width Wx = Ww + Wn of the filament Lx, There is no shortage of sex.
In other words, the dimensional relationship between the width Ww of the wider collar portion and the width Wn of the narrow collar portion of the line Lx is such that (Ww−Wn) / 2Wn is 0.5 or less. Here, 2Wn, that is, twice Wn corresponds to the line width W when the collar portion is ideally printed and formed, and is printed when it is equal to the groove width of the concave portion of the intaglio plate surface. The line Ly shown in FIG. 1C belonging to one group of parallel line groups corresponds to this. Further, Ww−Wn corresponds to the width of the flange portion on one side that has increased with the increase in printing speed, that is, the width ΔW of the leakage portion 5, and the width ΔW = Ww−Wn of the leakage portion 5. The leaking portion 5 is a portion where ink leaked from the concave portion to the convex portion of the printing plate is transferred and printed on the printing plate during intaglio printing. Therefore, the line width Wx of the filament Lx is a width obtained by adding the width ΔW of the leakage portion 5 to 2Wn which is the line width W when the collar portion is ideally printed and formed, and it can be said that Wx = 2Wn + ΔW. . (Ww−Wn) / 2Wn is ΔW / 2Wn, and if the width of the leakage portion 5 is 50% or less of the ideal line width 2Wn, the influence on the display display image quality can be allowed. Therefore, in this embodiment, (Ww−Wn) / 2Wn = (8 μm−7 μm) / (2 × 7 μm) = 1 μm / 14 μm = 0.07 (7%), and the condition of 0.5 or less is satisfied. It is.

  On the other hand, if the printing speed is increased and (Ww−Wn) / 2Wn exceeds 0.5, the anisotropy of the line width is conspicuous and the uniformity of the image quality is lowered, which adversely affects the product quality. Note that (Ww−Wn) / 2Wn> 0.5 when the width Ww of the thicker collar is more than twice the width Wn of the narrower collar.

[Details of each layer]
Hereinafter, each layer of the electromagnetic wave shielding material of the present invention will be described in more detail.

[Transparent substrate]
First, a known transparent material may be used for the transparent substrate 1, and there are an organic substrate such as a resin film, and an inorganic substrate such as glass and ceramics. In view of properties, heat resistance, mechanical strength, handleability, etc., resin films (or sheets) are typical. The resin of the resin film (or sheet) is, for example, a polyester resin such as polyethylene terephthalate, an acrylic resin, a polycarbonate resin, a polyamide resin, a polyolefin resin such as a cycloolefin polymer, or a cellulose resin such as triacetyl cellulose. Resin or the like. Among these, a biaxially stretched polyethylene terephthalate film is a suitable material. The thickness of the transparent substrate 1 is usually 12 to 500 μm, preferably 25 to 200 μm, in view of handling properties and cost, but is not particularly limited.
In addition, the transparent base material 1 is preferably a resin film from which a flexible (flexible) material can be selected from the viewpoint of productivity in the roll-to-roll method with excellent productivity. Further, in this respect, the transparent substrate 1 is preferably a continuous strip-like resin film that is continuously long in the longitudinal direction to such an extent that it can be wound around a roll.

[Primer layer]
The primer layer 2 has a thickness difference between the formation part and non-formation part of the conductive convex pattern layer 3 as shown in FIG. 2 to be described later, and is a layer peculiar to the so-called drawing primer type intaglio printing method. Form as a layer. A thermoplastic resin, a curable resin, or the like can be used as the resin, and a thermosetting resin or an ionizing radiation curable resin can be used as the curable resin. However, as the resin, an ionizing radiation curable resin is preferably used in that a rapid change from a fluid state to a solidified state can be controlled during intaglio printing. The ionizing radiation curable resin can be appropriately selected from known ones. For example, a composition containing a monomer and / or a prepolymer that is polymerized and cured by ionizing radiation or the like is used. As the monomer or prepolymer, a radical polymerizable or cationic polymerizable compound is used. Among these, ionizing radiation curable resins using acrylate compounds are typical. Moreover, as ionizing radiation, ultraviolet rays, electron beams and the like are usually used. The thickness of the primer layer 2 after solidification is about 2 to 30 μm, preferably 7 to 23 μm.

[Conductive convex pattern layer]
The conductive convex pattern layer 3 is a layer formed by a drawing primer type intaglio printing method using a conductive composition in which conductive particles are dispersed in a resin binder, and is made of a solidified product of the conductive composition. Innumerable openings 4 are formed as non-formed portions of the conductive convex pattern layer 3 (see FIG. 1). The thickness of the conductive convex pattern layer 3 is usually about 2 to 100 μm, more preferably about 5 to 20 μm, from the viewpoint of electromagnetic shielding performance.

The plan view shape of the pattern of the conductive convex pattern layer 3 is a mesh shape, and has a pattern shape composed of two groups of parallel lines that intersect each other. The parallel line group is a line group in which a large number of lines forming a straight line are arranged in a direction perpendicular to the extending direction with their extending directions parallel to each other. When the angle at which the two groups of parallel filaments intersect is a right angle and the arrangement pitch of the two groups of parallel filaments is the same, a so-called square lattice pattern is obtained. In addition, the mesh shape may be a pattern in which the intersecting angle is not a right angle, the array pitch may be different in the two groups intersecting each other, and the array pitch itself may be irregular. The arrangement pitch (period) of the filaments Lx and Ly depends on the width of each filament, the aperture ratio, the desired electromagnetic wave shielding property and light transmittance, but generally the arrangement pitch of the filaments Lx and Ly is 150 to 500 μm.
In addition, the line width of a filament, ie, the line width of the convex part of the formation part 3a of the electroconductive convex pattern layer 3 (refer FIG. 2), is normally 5-50 micrometers from viewpoints, such as electromagnetic wave shielding performance. Further, the aperture ratio of the conductive convex pattern layer 3 [(total area of the openings 4 of the conductive convex pattern layer 3 / formation of the openings 4 of the conductive convex pattern layer 3 and the conductive convex pattern layer 3] The total coverage area including the portion 3a) defined by x100] is about 50 to 95% from the viewpoint of compatibility with electromagnetic wave shielding performance and visible light transmittance.

The conductive composition for forming the conductive convex pattern layer 3 is a liquid composition (ink) in which conductive particles are dispersed in a resin binder, such as solvent drying, ionizing radiation irradiation, and heating. The composition is solidified by solidification means such as energy addition and chemical reaction, and the solidified product exhibits conductivity. For the conductive particles and the resin binder, known materials such as a conductive paste and a conductive ink can be appropriately employed.
The conductive particles include gold, silver, platinum, copper, tin, aluminum, nickel particles or colloids of highly conductive metals (or alloys thereof), or resin particles or inorganic non-metallic particles on the surface of gold, silver. For example, metal-coated particles coated with the above highly conductive metal (or an alloy thereof), graphite particles, or the like is used.
The resin binder is the remaining component obtained by removing the conductive particles from the conductive composition, and as the resin binder resin (binder resin), a thermoplastic resin, a thermosetting resin, an ionizing radiation curable resin, or the like is used alone. Combined. A thermoplastic polyester resin, a thermoplastic acrylic resin, or the like is used as the thermoplastic resin, and a melamine resin, a thermosetting polyester resin, a thermosetting acrylic resin, a thermosetting urethane resin, or the like is used as the thermosetting resin. Further, as the ionizing radiation curable resin, a composition containing a monomer and / or prepolymer that is polymerized and cured by ionizing radiation and the like is used. As the monomer or prepolymer, a radical polymerizable or cationic polymerizable compound is used. Among these, ionizing radiation curable resins using acrylate compounds are typical.
In addition, the conductive composition is composed of nano-sized conductive particles, conductive materials that can improve conductivity by low-temperature heating instead of high-temperature that causes deterioration of the resin constituting the transparent substrate 1 and the like such as baking and heating. A composition containing a resin, a conductive compound, a conductive compound that becomes conductive by a chemical reaction, or the like may also be used. In addition, the electrical conductivity may be improved by physical treatment such as induction heat treatment or other heat treatment, chemical treatment such as chemical treatment for reducing surface resistance by contact with acid or water, electrochemical treatment, or the like. .

  In the so-called “drawing primer type intaglio printing method” disclosed in the pamphlet of International Publication No. 2008/149969, for example, printing is performed as follows. A conductive composition such as a conductive paste as a printing ink before solidification is filled only by a doctor blade into the concave portion of the intaglio plate surface, and the conductive composition on the convex portion of the plate surface other than the concave portion is scraped off and removed. The surface of the conductive composition filled in the recesses is not completely flush with the plate surface (convex portions), and a slightly depressed recess is generated. When the transparent base material 1 on which the fluidized primer fluidized layer is still applied is supplied to the intaglio plate and the primer fluidized bed is pressure-bonded to the plate surface, the primer fluidized bed flows into the recess and fills the indentation. cover. In this state, the primer fluidized layer is solidified by curing by ultraviolet irradiation or the like to form the primer layer 2, and then the transparent base material 1 is released from the intaglio, and the primer layer 2 and the uncured conductive material are formed on the transparent base material 1. A printed matter in which the conductive convex pattern layer 3 having the solidified conductive composition or the conductive composition is laminated is obtained. Solidification of the conductive composition is performed after release when the uncured conductive composition contains a solvent, and after release or in the case of no solvent, or at the same time as primer solidification before release or primer solidification. To do later.

  And the big characteristic which such a printed matter by the "drawing primer system intaglio printing method" cannot be seen in other printing methods is conceptually shown in the sectional view of FIG. 2 (the transparent substrate 1 is omitted). Similarly, with respect to the interface between the primer layer 2 and the conductive convex pattern layer 3, the primer layer 2 has a thickness Ta at the formation portion 3a of the conductive convex pattern layer 3 that is not the same as that of the conductive convex pattern layer 3. The shape is thicker than the thickness Tb in the formation portion 3b. The thickness Tb of the non-formed part 3b is the thickness at the non-formed part 3b, that is, the central part of the opening 4, which is not affected by the thickness Ta of the formed part 3a.

  Furthermore, the interface between the primer layer 2 and the conductive convex pattern layer 3 has one or more of the following cross-sectional forms (A to C) (however, illustration is omitted in FIG. 2). (A) A cross-sectional configuration in which the interface between the primer layer 2 and the conductive convex pattern layer 3 is in a non-linear manner, (B) a component constituting the primer layer 2 and a component constituting the conductive convex pattern layer 3 And (C) a cross-sectional form in which the components contained in the primer layer 2 are present in the conductive composition constituting the conductive convex pattern layer 3. Such a cross-sectional form of the interface is such that the primer layer 2 reinforces the adhesion at the time of release between the primer layer 2 and the conductive convex pattern layer 3, and the printing material (ink conductive composition) from the intaglio plate ( This seems to be the reason why the transition to the transparent substrate 1) is promoted to enable high-precision and high-quality intaglio printing.

In addition, within the convex portion of the conductive convex pattern layer 3 itself, which is the formation portion 3a of the conductive convex pattern layer 3, as shown conceptually in FIG. 2, the conductive particles Cp are uniform and uniform. It is preferable that the internal structure has a distribution in which the conductive particles Cp are relatively distributed, not the distribution but relatively dense near the top of the convex portion and sparse near the primer layer 2 far from the top. The term “dense” refers to the number density (volume density) of the conductive particles Cp in the unit volume as viewed from the number of particles. That is, the distribution of the number density of the conductive particles Cp inside the convex portion is larger near the top portion P than near the primer layer 2. The larger the number density, the easier the electrical contact between the conductive particles Cp. Therefore, even if the average concentration of the conductive particles Cp in the conductive convex pattern layer 3 is the same, the number density is higher than that in the case where the same number of conductive particles Cp are uniformly distributed. A decrease in volume resistivity at a large portion contributes to a decrease in volume resistivity as a whole, and electromagnetic wave shielding performance is improved. Furthermore, since the number density of the conductive particles Cp near the boundary with the primer layer 2 is small, the adhesion between the conductive convex pattern layer 3 and the primer layer 2 is improved. The distribution state of the conductive particles Cp in the conductive convex pattern layer 3 does not depend on the extending direction of the filaments Lx and Ly (in the extending direction, the distribution of particles in a unit volume). Number density is constant). Therefore, the number density of the conductive particles Cp in such a unit volume can be evaluated by the number density (surface density) of the conductive particles Cp in the unit area on the main cut surfaces of the filaments Lx and Ly. That is, as shown in FIG. 2, if the distribution of the surface density of the conductive particles Cp in the main cutting plane is greater near the top portion P than in the vicinity of the primer layer 2, the volume density of the conductive particles Cp. It may be determined that the distribution near the top P is larger than that near the primer layer 2.
Thus, in order to make the conductive particles Cp unevenly distributed toward the top part P of the convex part, for example, while increasing the pressure-bonding force for pressure-bonding the transparent substrate 1 on which the primer fluidized layer is formed to the plate surface, the conductive composition is It is preferable to lower the viscosity and solidify after releasing from the plate surface without solidifying in the intaglio recess. In addition, the specific gravity difference between the conductive particles Cp and the resin binder, the viscosity of the conductive composition before solidification (the amount of resin material and resin, the amount of solvent, the amount of other additives, the shape of the conductive particles, the particle size distribution, the content Etc.), and also depends on the solidification conditions, etc., so these should be determined experimentally as appropriate. Regarding the specific gravity difference between the conductive particles Cp and the resin binder, if the top P is opposite to the direction of gravity (vertically upward) and the conductive convex pattern layer 3 is solidified from a fluid state, the conductive particles Cp specific gravity <resin binder specific gravity. If the top P is in the same direction as the direction of gravity (vertically downward) and the conductive convex pattern layer 3 is solidified from the fluidized state, the specific gravity of the conductive particles Cp> the specific gravity of the resin binder. However, in general, when a metal is used as the conductive particles Cp and an organic polymer compound is used as the resin binder, the specific gravity of the conductive particles Cp> the specific gravity of the resin binder. When the number density of the conductive particles is distributed as described above, the conductive convex pattern layer 3 is solidified with the apex P in the same direction as the direction of gravity.

(Leakage part)
In the “pulling primer type intaglio printing method”, a highly accurate conductive convex pattern layer 3 can be formed. However, as described with reference to FIG. 3, when the printing speed is increased, the leakage portion 5 is generated. If productivity is not taken into consideration at all, it is only necessary to print at a printing speed that can be almost ignored even if the leakage portion 5 does not occur, but since productivity is closely related to product cost, printing is possible as much as possible. It is preferable to increase the speed. Therefore, the present invention defines an allowable range even when the leakage portion 5 occurs.

  In the “pulling primer type intaglio printing method”, unlike the conventional intaglio printing method, the surface to be printed during printing is a fluidized primer fluidized bed, so that the leakage portion 5 is on the surface of the printing object. Instead of transferring and depositing, it sinks under the surface and transfers. That is, the primer fluidized bed is embedded (embedded) in the solidified primer layer 2. FIG. 1A is a cross-sectional view conceptually showing this state, and the leakage portion 5 is a fitting portion fitted into the primer layer 2 in the printed product. Further, the leakage portion 5 has a positive direction in the scraping direction Xd of the doctor blade 35, that is, downstream of the groove forming the recess as shown in FIG. As a result, the convex portion of the conductive convex pattern layer 3 has an asymmetric width between the left and right sides (upstream and downstream) of the convex portion of the conductive convex pattern layer 3. The cut surface shape is an asymmetric shape. The main cut surface is a cross section perpendicular to the surface of the transparent substrate 1 and perpendicular to the direction in which the filaments of the conductive convex pattern layer 3 extend.

  Therefore, in the present invention, even if the leaking portion 5 exists as shown in FIG. 1A, in the main cut surface shape of the convex portion of the conductive convex pattern layer 3, the flange portion extending from the top portion P to the primer layer surface is formed. When the widths Wn and Ww up to the leading ends En and Ew are printed and formed differently by the leaking part 5 in the left-right asymmetric shape, the width of the wide collar part is Ww and the width of the narrow collar part is Wn. (Ww−Wn) /2Wn≦0.5. As described above, the width of the flange portion is from the normal N passing through the top P of the conductive convex pattern layer 3 to the tip portions En and Ew of the flange portion where the conductive convex pattern layer 3 reaches the primer layer surface. The distance measured perpendicular to the normal N. The width of the collar portion is also the horizontal distance (distance in a direction horizontal to the surface of the transparent substrate 1) of the convex portions measured from the top P of the conductive convex pattern layer 3 toward both sides. . When the main cut surface shape of the concave portion of the intaglio 31 is left-right symmetric when printed and formed without causing the leakage portion 5, the width of the collar portion is symmetric and the same width, and the width at this time is narrower Wn is the same as the width. Accordingly, the line width W at this time is 2 Wn. Further, Ww−Wn = ΔW corresponds to the width of the leakage portion 5. In other words, it has been found that if the width ΔW of the leakage portion 5 is set to ½ or less of the line width 2Wn at which the leakage portion does not occur (ideal), the appearance is acceptable. Of course, the number of leaking parts 5 should be small, and more preferably (Ww−Wn) /2Wn=ΔW/2Wn≦0.2 from the viewpoint of homogeneity. Further, among the width Wx = Ww + Wn of the filament Lx, a desired electromagnetic wave shielding property is ensured at the portion of (Ww + Wn) −ΔW = 2Wn and the portion of the filament Ly at the width 2W.

  By the way, the size (width) of the leaking portion 5 is the direction in which the filaments of the two parallel filament groups intersecting each other constituting the mesh shape in the plan view shape of the conductive convex pattern layer 3 extend. However, it appears remarkably when it is in a direction perpendicular to the scraping direction Xd of the doctor blade 35 during printing, in other words, parallel to the direction in which the doctor blade 35 extends. When the direction in which the filament extends extends from the direction perpendicular to the scraping direction Xd, the size of the leakage portion 5 decreases, and the direction in which the filament extends is parallel to the scraping direction Xd. Does not appear {see FIG. 1 (c)}. In the embodiment, the extending direction of one group of the line Lx out of the two groups of parallel lines is perpendicular to the scraping direction Xd, and the other group of lines Ly is the scraping direction Xd. The parallel line group of two groups intersects at right angles to each other, and is the case where the anisotropy is most remarkable.

However, the groove pattern formed by the concave portions 32 on the plate surface of the intaglio plate 31 is not limited to this. For example, the conductive convex pattern layer 3 formed by printing may have an angle other than a right angle at which the two groups of parallel line segments intersect each other, and even if the angle is a right angle, the two groups of the line groups are formed. It may be formed using an intaglio 31 whose linear shape is not orthogonal to the scraping direction Xd.
That is, the X-axis direction of the XY coordinate system shown in FIG. 3A that defines the directional relationship during printing and the X-axis of the XY coordinate system shown in FIG. 1B that defines the directional relationship on the printed matter. The X axis of both coordinate systems intersect each other without matching the directions of the axes and being parallel. In addition, although the XY coordinate system shown in FIG. 1B that defines the directional relationship on the printed material is an orthogonal coordinate system, the X-axis and the Y-axis are arranged in two parallel line groups. Indicates the direction in which the filament extends, and when the two parallel filament groups do not intersect at right angles, the XY coordinate system is not an orthogonal coordinate system but an oblique coordinate.

Therefore, when the leaking part 5 that cannot be ignored occurs in both groups of the two groups of parallel lines that intersect with each other and the widths of both side collars are different, the above-mentioned provisions regarding the widths of the collar parts should be applied to both groups. Is preferred. For example, both the extending direction of the line group Lx and the extending direction of the line group Ly intersect with the scraping direction Xd at an angle of 45 degrees, and the line group Lx and the line group Ly are mutually Form in which a square lattice is formed orthogonally (in FIG. 3A, when the groove of the recess 32 on the plate surface is rotated 45 degrees clockwise on the plate surface (the others remain as in FIG. 3A) )). In this case, as shown in FIG. 1, the widths Wn and Ww of the flanges are different for each filament Lx and each filament Ly (Wn <Ww). In this case, for each of the filaments Lx and each of the filaments Ly, (Ww−Wn) /2Wn≦0.5, and for each of the filaments Lx and each of the filaments Ly, It is designed so as to ensure a desired electromagnetic shielding property only in a portion having a width of 2 Wn in total, Wn on both sides from the top P. In addition, when the conductive convex pattern layer 3 is a square lattice, both the extending direction of the line group Lx and the extending direction of the line group Ly with respect to the scraping direction Xd are, for example, 5 degrees each. The same applies to the case of 85 degrees, the case of 15 degrees and 75 degrees, the case of 30 degrees and 60 degrees, and the like.
In the conductive convex pattern layer 3 printed on the continuous belt-shaped transparent substrate 1, the longitudinal direction of the transparent substrate 1 is usually parallel to the doctor blade scraping direction Xd. In terms of the angle, the “scraping direction Xd” can be rephrased as the “longitudinal direction”.

[Conductive metal layer]
The surface resistivity may be lowered by further forming a conductive metal layer on the surface of the conductive convex pattern layer 3 by electrolytic plating or the like. In this case, a conductive pattern layer is constituted by the conductive convex pattern layer 3 and the conductive metal layer, and the surface resistivity of the conductive pattern layer as a whole may satisfy the requirement. The metal of the conductive metal layer is not particularly limited as long as it is highly conductive and easily plated metal (or alloy). For example, copper, silver, gold, platinum, chromium, nickel, tin, etc. Can be used. Especially, since copper is excellent in material cost and electroconductivity, it is 1 type of a preferable metal.

[Blackening treatment]
Further, the conductive metal layer may be further blackened. As the blackening treatment, a known treatment such as blackening nickel plating, copper-cobalt alloy plating, or roughening treatment can be used. The darkening process improves the bright room contrast of the image.

[Other layers]
The electromagnetic wave shielding material according to the present invention may include other layers other than those described above as long as they do not depart from the gist of the present invention. For example, a rust preventive layer for preventing the surface oxidation of the conductive metal layer, a flattening resin layer for flattening unevenness due to the conductive convex pattern layer 3, and the side opposite to the side on which the conductive convex pattern layer 3 is formed An adhesive layer for adhering to an adherend such as a display front plate on the surface of the transparent substrate 1, a separator film for temporarily protecting the surface. Or it is various optical filters with respect to the surface by the side of the conductive convex pattern layer 3, or the surface of the transparent base material 1 of the other side, other functional layers other than an optical filter, etc. For example, an optical filter includes a near infrared absorption layer, an ultraviolet absorption layer, a neon light absorption layer, a color correction layer, an antireflection layer (antiglare, antireflection, antiglare and antireflection), or external light from a fine louver. Anti-reflection layer (see JP 2007-272161 A) and the like, and functional layers other than the optical filter include a protective layer, a hard coat layer, an anti-static layer, a contamination-preventing layer, an impact resistant layer, an adhesive layer, etc. is there. In addition, what is necessary is just to use a well-known thing suitably for these layers.

[Use]
The electromagnetic wave shielding material according to the present invention is a PDP, CRT, and the like used for display units of television receivers, measuring instruments and instruments, office equipment, medical equipment, computer equipment, telephones, electronic signboards, game machines, etc. It is suitable for a front filter of various image display devices such as LCD and EL, and particularly suitable for a PDP. In addition, it is also used for electromagnetic shielding in windows for buildings such as houses, schools, hospitals, offices, stores, vehicles, vehicles, aircraft, ships, etc., windows for various household appliances such as microwave ovens, etc. It can be used.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Primer layer 3 Conductive convex pattern layer 3a Formation part of conductive convex pattern layer 3b Non-formation part of conductive convex pattern layer 4 Opening part 5 Leakage part 10 Electromagnetic wave shielding material 31 Cylinder-shaped intaglio 32 Recesses (grooves) on the plate surface
33 Ink pan 34 Ink (conductive composition)
35 Doctor blade Cp Conductive particle Lx Line (group) extending in the direction perpendicular to the X axis
Lys (group) extending in the direction perpendicular to the Y axis
Ta Thickness of primer layer of conductive convex pattern layer forming portion (convex portion) Tb Thickness of primer layer of non-forming portion of conductive convex pattern layer W Line width Wn Width of narrow flange Ww Wide one Width of the ridge Wx Line width (in the X-axis direction) of the line Lx perpendicular to the X-axis Wy Line width (in the Y-axis direction) of the line Ly perpendicular to the Y-axis ΔW Width of the leaking part (= Difference in width of the narrow buttock)
X Coordinate axis parallel to the printing direction (= scraping direction) Xd Scraping direction of the doctor blade (= printing direction)
Xp Rotation direction of plate Y Coordinate axis orthogonal to X axis

Claims (2)

A conductive convex pattern layer containing conductive particles and a binder resin is formed as a conductor pattern layer on a transparent substrate via a primer layer, and a large number of openings as non-formation portions of the conductive convex pattern layer In the electromagnetic wave shielding material, the primer layer is thicker at the formation portion of the conductive convex pattern layer than the thickness at the non-formation portion of the conductive convex pattern layer.
The conductive convex pattern layer has at least one group of two groups of parallel lines intersecting each other, and the main cut surface shape of the convex part, which is the formation part of the conductive convex pattern layer, is from the top on both sides of the top. When the width of the collar part up to the primer layer surface is different, the width of the wide collar part is Ww, and the width of the narrow collar part is Wn, (Ww−Wn) / 2Wn is 0.5 or less. Electromagnetic wave shielding material. The electromagnetic wave shielding material according to claim 1, wherein the distribution of the conductive particles in the convex portion of the conductive convex pattern layer is relatively sparse in the vicinity of the primer layer and dense in the vicinity of the top portion.

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