JP2013062364A - Electromagnetic wave shielding member, combined laminate, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding member which prevents moire generation caused by interference with a pixel array of an image display panel, simultaneously prevents light and shade irregularity caused by coarseness and fineness of a mesh pattern, and prevents reduction in contrast caused by external light reflection in a mesh while keeping conductivity, and to provide a combined laminate and image display device which use the electromagnetic wave shielding member.SOLUTION: An electromagnetic wave shielding member comprises a conductor pattern layer 1 having a dark color layer 2 on its surface. A mesh pattern 1P, which is shown by the conductor pattern layer and defines many openings A, is formed by many boundary lines L extending between two branch points B to define the openings where an average number N of the boundary lines L extending from one branch point is equal to or larger than 3.0 and smaller than 4.0 (3.0≤N<4.0), and includes a region where there is no direction in which the openings are arranged in a regular cycle period. Preferably, the opening includes at least a pentagon and a hexagon.

Description

The present invention relates to an electromagnetic wave shielding material suitable for being arranged on the front surface on the image viewer side of a display, a composite laminate obtained by further combining the same, and an image display apparatus using these.
In particular, the present invention relates to an electromagnetic wave shielding material and a composite laminate that do not cause moiré due to interference with a pixel arrangement of an image display panel, and that can prevent a decrease in contrast due to external light, and an image display device using these.

Various image display panels such as a liquid crystal display panel, a plasma display panel, and an EL (electroluminescence) panel are widely used. An optical filter is disposed on the front surface of the image display panel. For example, in a plasma display panel, an electromagnetic wave shielding material is used as an optical filter disposed on the front surface. The electromagnetic shielding material is usually made of a metal mesh having a spatial period in which unit lattices such as a square lattice are repeatedly arranged in a plane (Patent Document 1).
However, since the electromagnetic wave shielding material made of a metal mesh having such a periodic pattern has a periodic arrangement of the pixel arrangement of the image display panel, it interferes with the arrangement period of the pixels and a moire (striped pattern) is generated.

In order to prevent this moire, the electromagnetic wave shielding material is usually provided with a so-called bias angle in which the arrangement direction of the metal mesh is inclined by about 3 to 45 ° from the arrangement direction of the pixels of the display panel (Patent Document 2). ).
In addition, the optical filter disposed on the front surface of the image display panel is also required to have a function of preventing the image from being whitened and the contrast from being lowered due to mixing of external light.

Patent Document 2 proposes an electromagnetic wave shielding material in which a contrast improving filter is laminated. The contrast enhancement filter usually has a contrast enhancement layer composed of a periodic pattern in which dark light absorption portions and light transmission portions are alternately arranged in a stripe pattern in a plane. The periodic pattern of the contrast enhancement layer also interferes with the pixel arrangement period of the image display panel, and moire occurs. In order to prevent this moire, it is known that the contrast improving layer is similarly provided with a bias angle with respect to the arrangement direction of the pixels of the image display panel.
Furthermore, since the contrast improving layer interferes with the metal mesh of the electromagnetic wave shielding material and moire is generated in the optical filter, it is known to provide a bias angle between the contrast improving layer and the metal mesh (Patent Document). 2).

  In this way, by combining elements having a periodic pattern, the moiré prevention is performed for each of the three patterns of the metal mesh, the contrast enhancement layer, and the image display panel for each size of the image display panel to be applied. Each cycle, the ratio between cycles, dimensions, and the like are taken into account, which complicates product design.

Thus, a randomized periodic pattern has been proposed. For example, for a square mesh metal mesh, if the square lattice is arranged in two directions, which are the X-axis direction and the Y-axis direction, the arrangement period is randomized only in one direction, for example, the X-axis direction. An electromagnetic shielding material (Patent Document 3).
Alternatively, based on the square lattice pattern of FIG. 17A, as shown in FIG. 17B, the four interior angles at the lattice points of the vertical and horizontal lines are all set to angles other than 90 °. This is an electromagnetic wave shielding material randomized (Patent Document 4).
However, in the randomization according to Patent Document 3 and Patent Document 4, periodicity remains in the array, and moire remains.

  On the other hand, an electromagnetic wave shielding material made of a metal mesh formed by chemical treatment combining organic solvent treatment and acid treatment has also been proposed (Patent Document 5). The metal mesh has a completely random pattern, and according to the electromagnetic wave shielding material, moire is eliminated.

Japanese Patent No. 3388682 JP 2009-535673 A JP-A-11-121974 JP-A-4-2179797 Pamphlet of International Publication No. 2007/114076

However, the electromagnetic wave shielding material according to Patent Document 5 has a coarse and dense mesh pattern, and uneven density is visually observed, resulting in uneven brightness in a display image arranged on the front surface of the image display panel.
In addition, regardless of the presence or absence of a contrast enhancement layer, the screen is whitened and the contrast is reduced because external light is reflected on the surface of the metal mesh, and a blackened layer is formed on the surface. It is common to prevent external light reflection. However, existing blackening layers such as blackening nickel plating, copper-cobalt alloy plating, and copper oxide blackening layer have been difficult to achieve both conductivity and antireflection of external light.
In addition, the part of the completely random mesh pattern of Patent Document 5 partially enters the opening and becomes a dead end due to the manufacturing method. Such a dead end portion is disconnected and the circuit is opened, and the conductivity (electromagnetic wave shielding property) at the same aperture ratio is lower than that of a mesh pattern including only a closed circuit such as a square lattice.

That is, an object of the present invention is to prevent the occurrence of an array caused by interference with the pixels of the image display panel and to prevent uneven brightness due to the density of the conductive mesh at the same time, and to ensure sufficient conductivity. However, it is to prevent whitening of the screen and deterioration of contrast due to reflection of external light on the mesh surface.
Moreover, it is providing the image display apparatus provided with such an electromagnetic wave shielding material or a composite laminated body.

Therefore, in the present invention, an electromagnetic wave shielding material, a composite laminate, and an image display device having the following configurations are provided.
(1) An electromagnetic wave shielding material having a conductor pattern layer and a dark color layer formed on at least one of the front and back surfaces thereof,
The planar shape of the conductor pattern layer is composed of a mesh pattern that defines a large number of openings, and this mesh pattern is formed from a number of boundary lines that extend between two branch points to define the openings. The average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0, and there is a direction in which the openings are arranged at a constant repetition period. A pattern that includes a non-
The dark color layer has a groove-like recess on the surface, and has a needle-like metal protruding on the surface on which the groove-like recess is formed.
Electromagnetic wave shielding material.
(2) The electromagnetic wave shielding material according to the above (1), comprising at least a pentagon and a hexagon as the shape of the opening in plan view.
(3) The composite laminate according to (1) or (2), wherein a transparent substrate is further laminated on the conductor pattern layer on which the dark color layer is formed.
(4) The electromagnetic wave shielding material according to any one of (1) to (3), wherein a functional layer is further laminated.
(5) An image display device comprising an image display panel, and the electromagnetic shielding material of any one of (1) to (3) or the composite laminate of (4) disposed on the front surface of the image display panel .

(1) According to the electromagnetic wave shielding material of the present invention, since the mesh pattern of the conductor pattern layer is a specific pattern having no periodicity, moire can be made extremely inconspicuous and the mesh pattern Brightness and darkness unevenness due to density can be made inconspicuously effectively, and both moire and lightness and darkness can be eliminated. Further, since it is not necessary to provide a bias angle for preventing moire, product design is facilitated. In addition, the dark layer with a specific surface structure provided on the surface of the conductive pattern layer suppresses external light reflection very effectively while maintaining conductivity, and can prevent deterioration in image contrast. And the ability to prevent contrast reduction.
(2) According to the composite laminate of the present invention, in addition to the above effects, functions other than the electromagnetic wave shielding function can be combined.
(3) According to the image display device of the present invention, the effect of the electromagnetic wave shielding material or the composite laminate can be enjoyed, and all of moire, light / dark unevenness, and contrast reduction can be prevented while maintaining sufficient conductivity. Can do.

Sectional drawing (A) and (C) and top view (B) explaining one Embodiment of the electromagnetic wave shielding material by this invention. The scanning electron micrograph which shows the groove-shaped recessed part of the surface of a dark color layer, and the surface structure of a acicular metal. The top view which shows an example of a mesh pattern. The top view explaining that a repeating period does not exist in a mesh pattern. The figure which shows the method of determining a generating point in the method of designing a mesh pattern. The figure which shows the method of determining a generating point in the method of designing a mesh pattern. The figure which shows the method of determining a generating point in the method of designing a mesh pattern. The figure explaining the degree of dispersion | distribution of the determined mother point group by an absolute coordinate system and a relative coordinate system. The figure which shows the method of creating a Voronoi diagram from the determined generating point and determining a mesh pattern. The top view which shows the mesh pattern by this invention. The top view which shows the pixel arrangement | sequence of an image display panel. The top view which shows the state which accumulated FIG. 10A and FIG. 10B. The top view which shows the periodic pattern which the conventional conductor pattern layer has. The top view which shows the pixel arrangement | sequence of an image display panel. The top view which shows the state which accumulated FIG. 11A and FIG. 11B. The top view which shows the example of a shape of an opening part. The top view which shows an example by which the mesh pattern was repeated as a unit pattern area | region of the magnitude | size of 1/3 or more of the dimension of an electromagnetic wave shielding material. Sectional drawing which shows another embodiment (with a transparent base material) of the electromagnetic wave shielding material by this invention. Sectional drawing which shows embodiment of the composite laminated body by this invention. 1 is a cross-sectional view showing an embodiment of an image display device according to the present invention. It is a top view which shows an example of the random pattern in the conventional electromagnetic wave shielding material, (A) is before randomization, (B) is after randomization.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are conceptual diagrams, and the scale relations, aspect ratios, and the like of components may be exaggerated as appropriate for convenience of explanation.

[A] Definition of terms:
Hereinafter, definitions of main terms used in the present invention will be described here.

“Sheet surface” means a surface coinciding with the plane direction when the sheet-like electromagnetic shielding material is viewed as a whole and globally. Usually, it becomes a surface parallel to the front surface, back surface, or both front and back surfaces of the electromagnetic wave shielding material. In FIG. 1, it is an XY plane or a plane parallel thereto.
“Front surface”, “back surface”, and “side surface” are one surface of two surfaces parallel to the sheet surface being “front surface” and the other surface being “back surface”. There is no distinction between one side as “front” or “back”. The “side surface” is a surface that is not parallel to the sheet surface, typically a surface perpendicular to the sheet surface, and corresponds to a surface that is exposed as a cross section of the layer.
The “planar shape” means a shape in a plane parallel to the “sheet surface”. In other words, the “planar shape” means a shape viewed from the direction of the normal line set on the “sheet surface”.
The terms “sheet”, “film” and “plate” are not distinguished from each other based solely on the difference in designation. Therefore, for example, a “sheet” is a concept including a member that can also be called a film or a plate.

[B] Electromagnetic wave shielding material:
An electromagnetic wave shielding material according to the present invention will be described with reference to an embodiment shown in FIG.

As shown in the cross-sectional view of FIG. 1A, the electromagnetic wave shielding material 10 of the present invention illustrated in FIG. 1 includes the conductor pattern layer 1 and all the front and back surfaces and both side surfaces of the conductor pattern layer 1. And a dark color layer 2 formed on the surface. The dark color layer 2 has a groove-like recess 3 on the surface, and has a needle-like metal 4 on the surface where the groove-like recess 3 is formed. Due to the surface structure of the dark color layer 2 having the groove-like recess 3 and the needle-like metal 4, external light is effectively absorbed, and reflection of external light by the conductor pattern layer 1 can be extremely effectively prevented.
In particular, when the light enters the inside of the groove-shaped recess 3 by the valley-shaped groove-shaped recess 3 having branching, meandering, or both, the reflection is attenuated by repeating the reflection many times in a complicated path. For this reason, reflection of external light is prevented by the groove-shaped recess 3.
In addition, the needle-shaped metal 4 also absorbs and scatters many times while the external light is reflected multiple times on the surface between the needles, attenuates a lot of light, and greatly increases the amount of reflected light, particularly the amount of specularly reflected light. Decrease to prevent reflection of external light.

As shown in the plan view of FIG. 1B, the conductor pattern layer 1 has a large number of openings A when viewed from above, that is, when the sheet-like electromagnetic shielding material 10 is viewed in the Z-axis direction. A unique mesh pattern 1P that defines This mesh pattern 1P is formed from a number of boundary line segments L extending between two branch points B and defining the opening A, and the average value of the number of boundary line segments L extending from one branch point B N is a pattern including a region where 3.0 ≦ N <4.0, and there is no direction in which the openings A are arranged at a constant repetition period.
FIG. 1C is a cross-sectional view taken along line CC in FIG. As shown in the sectional view of FIG. 1C, the width t1 of the opening A across the line CC (corresponding to a virtual line segment di extended at an arbitrary angle to an arbitrary position in FIG. 4). t2, t3,... are not constant. The opening A defined by the mesh pattern 1P corresponds to a unit lattice in a lattice-like periodic mesh pattern such as a conventional square lattice. In this respect, the mesh pattern 1P is constituted by a plurality of unit lattices, that is, openings A arranged adjacent to each other with a boundary line segment L therebetween.
In FIG. 1C, only the conductor pattern layer 1 is drawn, and other illustrations such as the dark color layer 2 are omitted.

  For this reason, in the present embodiment, the mesh pattern 1P is not a periodic arrangement as in the prior art, but the mesh pattern 1P is an aperiodic pattern. Moire due to interference with the array does not occur, light and dark unevenness does not occur, and moire and light and dark unevenness can be extremely effectively prevented.

  FIG. 2 is a scanning electron micrograph specifically showing the groove-like recess 3 and the needle-like metal 4 on the surface of the dark color layer 2. In the figure, it can be seen that a large number of needle-shaped metals 4 are present on the surface having the groove-shaped recess 3.

[Conductor pattern layer]
The conductor pattern layer 1 is made of a conductive material and exhibits a non-periodic mesh pattern 1P having a plan view shape unique to the present invention.
As the conductive material, metals such as copper, aluminum, tin, and nickel can be used. The conductor pattern layer 1 can be obtained by forming a predetermined mesh pattern 1P from such a metal foil made of metal, a metal thick film, or the like by a photoetching method or the like.
The thickness of the conductor pattern layer 1 is usually about 2 to 100 μm, more preferably about 5 to 20 μm, from the viewpoint of electromagnetic wave shielding performance (conductivity), formation method and the like.
The line width of the mesh pattern 1P is usually 5 to 50 μm from the viewpoint of electromagnetic wave shielding performance and the like. The area ratio of the opening A is about 50 to 95% in terms of compatibility between transparency and electromagnetic wave shielding performance.

[Mesh pattern and openings defined by it]
The mesh pattern 1P has a planar view shape when the conductor pattern layer 1 is observed from the normal direction of the sheet surface (Z-axis direction in FIG. 1). Hereinafter, the mesh pattern 1P will be described with reference mainly to FIG. 3 and FIG.

As shown in FIG. 3, the mesh pattern 1 </ b> P is formed from a large number of boundary line segments L that extend between the two branch points B and define the opening A. An average value N of 3.0 ≦ N <4.0, that is, 3.0 or more and less than 4.0, and is repeated in the opening A defined by the boundary line segment L. The pattern includes a region where there is no direction having a period.
Note that the mesh pattern 1P has an arrangement in which the opening A does not have a direction having a repetition period, and the moire prevention effect is sufficiently exhibited. The area and shape of the opening A may be a pattern that is not constant. Preferably, 50% or more of the openings A having the same number of boundary line segments L surrounding the periphery have different areas and shapes. More preferably, the openings A having the same number of boundary line segments L that surround the periphery are spread over the entire area of the mesh pattern 1P so that the areas and shapes thereof are all different from each other. In other words, among the openings A included in the mesh pattern 1P, the shapes and areas of the openings A having the same number of boundary line segments L that surround the periphery are not all the same, and at least a part of them is other. Means that it will be different. Here, the number of boundary line segments L surrounding the periphery is the same as the number of corners of the polygon when the opening A is a polygon. In the above description, even when the two openings A are congruent figures and have different directions, the shapes of the two openings A are considered to be different from each other.

  As shown in FIGS. 3 and 9, the line portion Lt of the mesh pattern 1P includes a large number of branch points B. The line portion Lt of the mesh pattern 1P is composed of a number of boundary line segments L that form branch points B at both ends. That is, the line portion Lt of the mesh pattern 1P is composed of a number of boundary line segments L extending between the two branch points B. Then, at the branch point B, the boundary line segment L is connected, so that the opening A is defined. In other words, it is surrounded by a boundary line segment L and is partitioned to define an opening A as one closed region.

  As shown in FIGS. 3 and 9, since the line portion Lt is composed only of the boundary line segment L, it extends into the opening A as in the mesh pattern disclosed in Patent Document 5 and becomes a dead end. The line part Lt does not exist. According to such an aspect, it is possible to effectively realize providing the electromagnetic wave shielding material 10 with sufficient conductivity and high transparency at the same time.

  On the other hand, in order to prevent the occurrence of moire, in the mesh pattern 1P included in the conductor pattern layer 1 of the electromagnetic wave shielding material 10 according to the present embodiment, the entire region does not have a direction in which the opening A has a repeating cycle. It has become. In order to surely eliminate moiré, it is preferable that the entire area of the mesh pattern 1P is composed of only such areas. The present embodiment has such a configuration. As a result of intensive research, the inventors of the present invention do not simply irregularize the pattern of the mesh pattern 1P, but the openings A of the mesh pattern 1P are arranged at a repeating cycle having a certain regularity. By defining the pattern of the mesh pattern 1P so that there is no existing direction, an electromagnetic wave shielding material such as a conventional square lattice structure in which the openings A are periodically arranged, and an image display having a periodic pixel arrangement It has been found that moiré that can occur when stacked with a panel can be made very inconspicuous.

[No repeat cycle]
FIG. 4 shows a sheet surface parallel to the XY plane for explaining that there are no regions where a large number of openings A defined by the mesh pattern 1P are arranged at a constant cycle and there is no repeating cycle. It is a top view in FIG. Within the plane of the sheet surface, in the figure, one virtual straight line di that faces an arbitrary direction at an arbitrary position is selected.
This one straight line di intersects with the boundary line segment L of the line portion Lt to form an intersection. The intersections are shown as intersections c1, c2, c3,..., C9 in order from the lower left in the drawing. The distance between adjacent intersections, for example, the intersection c1 and the intersection c2, is the dimension t1 on the straight line di of the certain opening A. Next, the dimension t2 on the straight line di is similarly determined for another opening A adjacent to the opening A having the dimension t1 on the straight line di. Then, with respect to a straight line di in an arbitrary direction at an arbitrary position, from the boundary line segment L intersecting with the straight line di, a number of openings A that encounter the straight line di in an arbitrary direction at an arbitrary position are as dimensions on the straight line di. t1, t2, t3,..., t8 are determined. And the sequence of numerical values of t1, t2, t3,..., T8 has no periodicity.
In FIG. 4, these t1, t2, t3,..., T8 are drawn separately from the mesh pattern 1P together with the straight line di at the bottom of the drawing for easy understanding.

When the straight line di is rotated at an arbitrary angle from the position shown in FIG. 4 to obtain the dimensions t1, t2,... Of each opening A in other directions, the straight line di is also the same as in FIG. There is no repetitive periodicity in the di direction.
That is, there is no direction having a repeating cycle in the opening A defined by the boundary line segment L, as in the sequence of numerical values of t1, t2, t3,.
In other words, in the arrangement of the openings A, the numerical sequence of the arrangement of the dimensions ti of the openings A on the virtual line segment di in any direction passing through any position becomes an aperiodic function. That is, there is no M that satisfies t (i) = t (i + M) (i and M are independent positive integers).
In this way, the fact that there is no direction in which the opening A has a repetition cycle is expressed as the absence of a direction in which the openings A are arranged at a constant repetition cycle.

  Furthermore, in the mesh pattern 1P according to the present embodiment, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0. Thus, when the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0, the array pattern of the mesh pattern 1P is represented by a square lattice pattern (N = 4.0), the pattern can be greatly different. In addition, when the average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N <4.0, it is also large from the honeycomb arrangement (N = 3.0). Different patterns can be used. Then, the average value N of the number of boundary line segments L extending from one branch point B is set to 3.0 ≦ N <4.0, and the arrangement of the openings A is made irregular so that the openings A It has been confirmed that it is possible to ensure that the directions arranged with the repetition period do not exist stably, and as a result, it is possible to make the moire extremely inconspicuous.

  Note that the average value N of the number of boundary line segments L extending from one branch point B is strictly determined by examining the number of boundary line segments L extending for all the branch points B included in the mesh pattern 1P. The average value is calculated. However, in actuality, the total number of boundary line segments L extending from one branch point B is considered in consideration of the size of the opening A per line defined by the line portion Lt. It extends about a branch point B included in a section having an area that can be expected to reflect a tendency (for example, a portion of 10 mm × 10 mm in the mesh pattern 1P in which an opening A is formed in a dimension example described later). The number of boundary line segments L to be output is checked to calculate the average value, and the calculated value is handled as the average value N of the number of boundary line segments L extending from one branch point B for the mesh pattern 1P. May be.

  Actually, in the mesh pattern 1P of the conductor pattern layer 1 of the electromagnetic wave shielding material 10 shown in FIG. 3, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 <N <. 4.0. For example, in the case of the mesh pattern 1P of FIG. 3, when a total of 387 branch points B are measured, the boundary line segment L has three branch points B and the boundary line segment L has four branches. The number of point B is 14 (the number of branch points where the number of boundary line segments L to branch is 5 or more is 0), and the average number of boundary line segments L coming from the branch point B (average branch number) is 3.04 Met.

[Moire generation due to interference with pixel array of image display panel]
FIG. 10C shows a state where the electromagnetic wave shielding material 10 having the mesh pattern 1P shown in FIGS. 3 and 10A is superimposed on a typical pixel array in the image display panel 40 shown in FIG. 10B. Has been. As can be understood from FIG. 10C, when the mesh pattern 1P shown in FIGS. 3 and 10A is actually produced and arranged on the pixel array of the image display panel 40, a striped pattern that can be visually recognized, That is, moire (interference fringes) did not occur.

  Here, the pixel array of the image display panel 40 shown in FIG. 10B is a typical pixel array in the image display panel 40. As shown in FIG. 10B, in the image display panel 40, one pixel P includes a sub-pixel (sub-pixel) RP that emits red light, a sub-pixel GP that emits green light, and a sub-pixel BP that emits blue light. , Is composed of. That is, the image display panel 40 can form an image in color. In the example shown in FIG. 10B, the pixels P are formed as a so-called stripe arrangement. That is, the sub-pixel RP that emits red light, the sub-pixel GP that emits green light, and the sub-pixel BP that emits blue light are sequentially arranged in one direction (vertical direction in FIG. 10B). On the other hand, the sub-pixel RP that emits red light, the sub-pixel GP that emits green light, and the sub-pixel BP that emits blue light are arranged one by one in the direction orthogonal to the one direction (the horizontal direction in FIG. 10B). It has been. 10B shows the image display panel 40 observed from the normal direction to the image forming surface (light-emitting surface, ie, screen) of the image display panel 40, in other words, from the normal direction to the panel surface of the image display panel 40. In this state, the arrangement of the pixels P is shown.

  On the other hand, in the conventional electromagnetic shielding material 50, FIG. 11A to FIG. 11C exemplify the occurrence of moire when there is a constant repetition period in the opening A defined by the periodic mesh pattern 51P.

What is illustrated in FIG. 11A is a square mesh periodic mesh pattern 51P, which is different from the mesh pattern 1P of the present invention.
11C shows the periodic mesh pattern 51P shown in FIG. 11A on a typical pixel array in the image display panel 40 shown in FIG. 11B (same as shown in FIG. 10B). The superimposed state is shown. As can be understood from FIGS. 11A, 11B, and 11C, when the electromagnetic shielding material 50 having the periodic mesh pattern 51P is arranged on the pixel array of the image display panel 40, the periodic mesh pattern 51P and the pixel Due to the interference with the regular pattern, light and dark streaks (light and dark streaks extending from the upper left to the lower right in the example shown in FIG. 11C) are visually recognized.

  In the example shown in FIGS. 11A and 11C, the arrangement direction of a large number of straight lines constituting the square lattice of the periodic mesh pattern 51P is inclined several degrees with respect to the arrangement direction of the pixels P. This inclination angle is referred to as a bias angle (degree). Such an inclination is a technique that is widely used in general to make moire inconspicuous. However, as can be understood from the fact that the striped pattern is visually recognized in FIG. 11C, the degree of moiré generation is not determined solely by the bias angle, but in addition, the repetition of the pixel P and the periodic mesh pattern 51P. It also depends on factors such as the cycle ratio and the line width of the periodic mesh pattern 51P. In order to eliminate moire only by the bias angle of the periodic mesh pattern 51P, it is necessary to prepare the electromagnetic shielding material 50 having different bias angles according to the design specifications of the image display panel 40.

[Mesh pattern pattern shape creation method]
Here, an example of a method for creating the mesh pattern 1P unique to the present invention will be described below.

  The method described here includes a step of determining a generating point, a step of creating a Voronoi diagram from the determined generating point, and a boundary line segment extending between two Voronoi points connected by one Voronoi boundary in the Voronoi diagram. Determining a path of L, and determining a thickness of the determined path to demarcate each boundary line segment L to determine a pattern of the mesh pattern 1P (line portion Lt). . Hereinafter, each step will be described in order. Note that the pattern shown in FIG. 3 described above is a pattern actually determined by the method described below.

  First, the process of determining a generating point will be described. First, as shown in FIG. 5, an absolute coordinate system O-X-Y (this coordinate system O-X-Y is a normal two-dimensional plane. The first generating point (hereinafter referred to as “first generating point”) BP1 is arranged at an arbitrary position of “. Next, as shown in FIG. 6, the second generating point BP2 is arranged at an arbitrary position separated from the first generating point BP1 by a distance r. In other words, at any position on the circumference of a circle with a radius r centered on the first generating point BP1 on the absolute coordinate system XY (hereinafter referred to as “first circumference”), the second A generating point BP2 is arranged. Next, as shown in FIG. 7, the third mother point BP3 is arranged at an arbitrary position away from the first mother point BP1 by the distance r and away from the second mother point BP2 by the distance r or more. Thereafter, the fourth generating point is arranged at an arbitrary position separated from the first generating point BP1 by the distance r and from the other generating points BP2 and BP3 by the distance r or more.

  In this way, the mother point is arranged at an arbitrary position away from the first mother point BP1 by the distance r and away from the other mother points until the next mother point cannot be arranged. Go. Thereafter, this operation is continued based on the second generating point BP2. That is, the next generating point is arranged at an arbitrary position separated from the second generating point BP2 by the distance r and from the other generating points by the distance r or more. Based on the second generating point BP2, until the next generating point cannot be arranged, it is at an arbitrary position away from the second generating point BP2 by the distance r and from the other generating points by the distance r or more. Place the mother point. Thereafter, the base point as a reference is sequentially changed, and the base point is formed in the same procedure.

  With the above procedure, the mother point is arranged until the mother point cannot be arranged in the region where the mesh pattern 1P is to be formed. When the mother point cannot be arranged in the region where the mesh pattern 1P is to be formed, the step of creating the mother point is completed. By the processing so far, the mother point group irregularly arranged on the two-dimensional plane (XY plane) is uniformly dispersed in the region where the mesh pattern 1P is to be formed.

With respect to the generating point groups BP1, BP2,..., BP6 (see FIG. 8A) distributed in the two-dimensional plane (XY plane) in such a process, the distances between the individual generating points are not constant. Have However, the distribution of the distance R between any two adjacent generating points is not a complete random distribution (uniform distribution), but a range ΔR between the upper limit value R _MAX and the lower limit value R _MIN with the average value R _AVG in mind. = R _MAX -R _MIN is distributed. Note that, here, two Voronoi regions XA are adjacent to each other, but when two Voronoi regions XA are adjacent after generating a Voronoi diagram from the generating point groups BP1, BP2,... It is defined that the generating points of are adjacent to each other.

That is, the generating point group described here is referred to as a coordinate system having each generating point as an origin (referred to as a relative coordinate system oxy, while a coordinate system defining an actual two-dimensional plane is referred to as an absolute coordinate system O. 8 (B), FIG. 8 (C),..., In which all the generating points adjacent to the generating point placed on the origin are plotted are obtained for all generating points. Then, when the graph of the adjacent generating points on all the relative coordinate systems is displayed with the origin o of each relative coordinate system superimposed, a graph as shown in FIG. 8D is obtained. The distribution pattern of adjacent mother point groups on the relative coordinate form is not a uniform distribution in which the distance between any two adjacent mother points constituting the mother point group is 0 to infinity, but the distance from the origin o. Is distributed in a finite range from R _AVG −ΔR to R _AVG + ΔR (a donut-shaped region from radius R _MIN to R _MAX ).
As can be seen from FIG. 8D, the azimuth (angle) distribution of other generating points viewed from an arbitrary generating point is isotropic (or substantially isotropic). This corresponds to the orientation (angle) distribution of the opening A in the mesh pattern 1P generated from these generating points (group) being isotropic (or substantially isotropic).

As described above, by setting the distance between each generating point, the Voronoi region XA obtained from the generating point group by the method described below, and the size of the opening A obtained from this (or The distribution of the area of the opening A) is not uniform (completely random) but distributed within a finite range.
By configuring in this way, the shading (brightness / darkness) unevenness when the mesh pattern 1P is viewed is more effectively eliminated. In order to make the shading unevenness of the mesh pattern 1P visible when the mesh pattern 1P is substantially invisible, and to make it compatible with anti-moire due to the non-periodicity of the mesh pattern 1P, the size D of the opening A (the size of the opening A) The maximum value of D) is D _MAX and the minimum value is D _MIN , the distribution range ΔD = D _MAX −D _MIN of the size D with respect to the average value D _AVG of the size D
0.1 ≦ ΔD / D _AVG ≦ 0.6
More preferably,
0.2 ≦ ΔD / D _AVG ≦ 0.4
And
Moreover, the average value D _AVG of the size of the opening A is set to about 100 to 1000 μm from the viewpoint of compatibility between transparency and electromagnetic wave shielding. Usually, it is about 150-300 micrometers.
Here, the size D of the opening A is defined as follows for all the openings A.
(1) When a circle passing through all the branch points B (all vertices in the case of a polygon) belonging to a certain opening A can be drawn, the size D is determined by the circumscribed circle diameter of the opening A. And
(2) If a circle passing through all branch points B belonging to a certain opening A (all vertices in the case of a polygon) cannot be drawn, the maximum distance between the two branch points B belonging to this opening A Let the value be the size D.

  In the step of determining the generating point, the size D of each opening A can be adjusted by changing the size of the distance r. Specifically, by reducing the size of the distance r, the size D of each opening A can be reduced, and conversely by increasing the size of the distance r, The size D of the opening A can be increased.

  Next, as shown in FIG. 9, a Voronoi diagram is created based on the arranged generating points. As shown in FIG. 9, the Voronoi diagram is composed of line segments that are drawn at the intersection of two bisectors by drawing a perpendicular bisector between two adjacent generating points BP and BP. FIG. Here, the line segment of the bisector is called Voronoi boundary XB, the intersection of Voronoi boundary XB forming the end of Voronoi boundary XB is called Voronoi point XP, and the area surrounded by Voronoi boundary XB is Voronoi area XA Call it.

  In the Voronoi diagram created as shown in FIG. 9, each Voronoi point XP forms a branch point B of the mesh pattern 1P. Then, one boundary line segment L is provided between two Voronoi points XP forming the end of one Voronoi boundary XB. At this time, the boundary line segment L may be determined so as to extend linearly between the two Voronoi points XP as in the example shown in FIG. Various paths (for example, circle (arc), ellipse (arc), fence line, hyperbola, sine curve, hyperbolic sine curve, elliptic function curve, Bessel function curve, etc.) between the two Voronoi points XP without It may be extended by a broken line or the like. When the boundary line segment L is determined to extend linearly between two Voronoi points XP as in the example shown in FIG. 3, each Voronoi boundary XB defines the boundary line segment L. It becomes like this.

  After determining the path of each boundary line segment L, the line width (thickness) of each boundary line segment L is determined. The line width of the boundary line segment L is determined in consideration of conductivity and transparency obtained by the conductor pattern layer 1 exhibiting the created mesh pattern 1P. As described above, the pattern of the mesh pattern 1P can be determined.

According to the present embodiment as described above, the mesh pattern 1P having the light absorbing portion 2 in the conductor pattern layer 1 of the electromagnetic wave shielding material 10 extends between the two branch points B to define a large number of openings A. Formed of a large number of boundary line segments L, the average value N of the number of boundary line segments L extending from one branch point B is 3.0 ≦ N <4.0, and the opening There is no direction in which A has a repeating cycle. As a result, even if the electromagnetic wave shielding material 10 is superimposed on the image display panel 40 in which the pixels P are regularly (periodically) arranged, the striped pattern (moire, interference fringe) is generated to such an extent that it can be visually recognized. This can be effectively prevented.

[Dark color layer]
The dark color layer 2 has a groove-like recess 3 on its surface, and has a needle-like metal 4 protruding on the surface where the groove-like recess 3 is formed. The dark color layer 2 is formed by blackening the surface of the conductor pattern layer 1 and attenuates external light. The dark color layer 2 may be a dark color, and may be a low-lightness color other than black, for example, a chromatic color such as brown.
In the electromagnetic wave shielding material 10 shown in FIG. 1, the dark color layer 2 is formed on all four surfaces of the surface corresponding to the boundary line segment L in the mesh pattern 1P of the conductor pattern layer 1, the back surface, and both side surfaces. Is provided. For this reason, the light from all the surroundings can be absorbed and reduced. However, the surface of the conductor pattern layer 1 on which the dark color layer 2 is provided may be at least one of the front and back surfaces of the conductor pattern layer 1. In the case of only one surface, external light reflection is prevented by using that surface as a surface on the viewer side when the electromagnetic wave shielding material 10 is applied to the image display panel.

(Groove-shaped recess)
The groove-shaped recess 3 of the dark color layer 2 can be formed as a base film of the dark color layer 2 by metal electroplating. This base film is for modeling a part of the surface of the dark color layer 2 (groove-shaped recess 3), and is handled as a part of the dark color layer 2 in the present invention.

The metal to be electroplated is not particularly limited as long as it is highly conductive and can be easily electroplated (or an alloy thereof). For example, copper, silver, gold, chromium, nickel, tin, or the like may be used. it can. Especially, copper is excellent in material cost and electroconductivity, and is preferable. The thickness of the plating film is, for example, 0.1 to 10 μm.
The electroplating may be a known method, and the electroplating conditions are, for example, a bath temperature of 20 to 60 ° C., a current density of 0.001 to 10 A / dm ² , and a plating time of about 1 to 10 min.
By increasing the current density, for example, 2 A / dm ² or the like, the groove-like recess 3 is easily generated as a valley-like shape having branches, meanders, or both on the surface of the plating film. Specifically, a solution containing copper sulfate pentahydrate 75 g / L, sulfuric acid 180 g / L, hydrochloric acid 60 mg / L, hydrocarbon polymer plating additive (orientation adjusting agent) 40 mL / L, bath temperature The processing conditions are 25 ° C., current density 2 A / dm ² , and plating time 5 min.
By such a groove-shaped recess 3, in particular, a valley-shaped groove-shaped recess 3 having branches, meanders, or both, when light enters the groove-shaped recess 3, it is attenuated by repeating reflection many times in a complicated path To do. As a result, external light reflection can be prevented by the groove-shaped recess 3.

(Needle metal)
The needle-shaped metal 4 of the dark color layer 2 is generated by blackening the surface of the base film provided for forming the groove-shaped recess 3.
The blackening treatment is performed by, for example, performing a roughening treatment by a cathodic electrolysis treatment using an electrolytic bath made of an aqueous solution containing copper sulfate pentahydrate and sulfuric acid, so that a needle made of copper is formed on the surface of the base film. The dark color layer 2 having the metal 4 can be formed. In the roughening treatment, after acicular metal 4 is deposited by cathodic electrolysis, metal plating is preferably performed thereon to prevent the acicular metal 4 from falling off, and then a metal film is preferably formed.
The acicular metal 4 is easily generated by increasing the current density. The length of the acicular metal 4 is about 0.1 to 1 μm. If the specific example of formation of the acicular metal 4 is shown, a 1st step will be copper sulfate pentahydrate 70g / L, sulfuric acid 100g / L, bath temperature 40 degreeC, current density 40A / dm < ² >, electrolysis time 5s, anode : Treated with platinum, the second stage is treated with copper sulfate pentahydrate 250 g / L, sulfuric acid 100 g / L, bath temperature 45 ° C., current density 20 A / dm ² , electrolysis time 30 s, anode: platinum.
By having a large number of needle-shaped metals 4 on the surface, external light incident on the dark color layer 2 is subjected to multiple reflections between the surfaces of the needle-shaped metal 4, so that absorption and scattering occur many times to attenuate the light. Thus, external light reflection is prevented.
Thus, by forming the dark color layer 2 having the groove-shaped recess 3 and the needle-shaped metal 4 on the surface, the external light antireflection performance is achieved by the synergistic effect of the effect of the groove-shaped recess 3 and the effect of the needle-shaped metal 4. Is further enhanced.

[Deformation]
The electromagnetic wave shielding material 10 of the present invention can take other various forms other than the above-described embodiments. Some of these will be described below.

[Shape of opening]
The shape of the opening A preferably includes at least a pentagon and a hexagon. By including at least a pentagon and a hexagon in the opening A, moire can be made inconspicuous, and unevenness in brightness due to the density of the mesh pattern 1P can be made more inconspicuous. More preferably, the shape of the opening A includes a pentagon, a hexagon, and a heptagon.
For example, when the mesh pattern 1P used in the form of FIG. 10A is measured for a total of 4631 openings A (polygon),
Triangle 0
79 squares
1141 pentagons
2382 hexagons
927 heptagons
94 octagons
Eight 9-sided
There were 0 decagons or more.
In addition, about this mesh pattern 1P, it was 3.07 when the average number of the boundary line segments L which come out from the branch point B was measured.

[Repeat as unit pattern area]
In the above-described embodiment, in the entire region of the conductor pattern layer 1 in the electromagnetic wave shielding material 10, the opening A defined by the mesh pattern 1 </ b> P does not have a direction having a repetition period. explained. However, as shown in FIG. 14, the entire area of the mesh pattern 1P is configured such that the entire area of the mesh pattern 1P is configured by collecting a plurality of unit pattern areas S, and each unit pattern area S Inside, the plurality of openings A may be formed of regions arranged in a pattern having no predetermined repetition period.
That is, in this embodiment, two or more unit pattern regions S in which openings are arranged in the same pattern are included in the entire region of the mesh pattern 1P when viewed locally. In this case, the connection between the unit pattern regions S is substantially inconspicuous and can be ignored unless there are four or more repetitions in a certain period in a specific direction. Of course, neither moire nor shading unevenness occurs in the unit pattern region S. In this example, the pattern of the mesh pattern 1P in one unit pattern region S can be created in the same manner as the pattern creation method described with reference to FIGS.

  In particular, recently, the image display panel has been increased in size. For such a large screen image display panel, the mesh pattern 1P is composed of an array of a plurality of unit pattern regions S, and It is much easier to create a pattern of the mesh pattern 1P by including a plurality of unit pattern regions S in which the openings A are arranged in the same pattern in the unit pattern region S. It is preferable in that it can be made.

  In particular, in the example in which a single type of unit pattern region S is arranged in a plurality of vertical and horizontal directions as shown in FIG. 13, there is a repetition as the unit pattern region S in a specific direction (two directions in the drawing vertical direction and horizontal direction). . In the embodiment of FIG. 13, the unit pattern region S is repeated with a repetition period SP2 in the horizontal direction and a repetition period SP1 in the vertical direction. Under these conditions, when the dimension of the unit pattern region S in a specific direction is Ls, and the unit pattern region S has M openings A in the dimension Ls on an arbitrary straight line dj extending in the specific direction, Focusing on a certain opening A on dj, the regularity that there is always an opening A having exactly the same dimension tj and shape at a position where the number of openings A is separated by M on the straight line dj. Have. That is, for the dimension tj of the opening A on the straight line dj, the kth dimension tj (k) counted in order on the straight line dj, and the Mth (k + M) th dimension tj (k + M) from there. Is the same, and the relationship of tj (k) = tj (k + M) is established (k and M are independent positive integers).

  However, this regularity is based on the repetition cycle as the unit pattern region S (in the above-described case, the dimension Ls corresponds to the repetition cycle). In the unit pattern region S, the opening A does not have a repeating cycle in the specific direction. In addition, the repetition cycle as the unit pattern region S is not close to the dimensional relationship in which moire is generated because the size differs from the arrangement cycle of the pixel arrangement of the image display panel by, for example, 1000 times or more.

  In the example shown in FIG. 13, the electromagnetic shielding material 10 is divided into six unit pattern regions S having the same shape, and the mesh pattern 1P included in each conductor pattern layer 1 in each unit pattern region S. Are configured identically. In the six unit pattern regions S, three regions are arranged in the vertical direction (vertical direction in the drawing) in FIG. 13 at the repetition cycle SP1, and two regions are arranged in the horizontal direction in FIG. 13 at the repetition cycle SP2. Are arranged as follows.

[Lamination of transparent substrate]
The electromagnetic wave shielding material of the present invention may have a configuration in which the transparent substrate 5 is laminated like the electromagnetic wave shielding material 10 of the embodiment shown in the cross-sectional view of FIG. The lamination of the transparent substrate 5 can increase the mechanical strength, and the conductive pattern layer 1 formed on the transparent substrate 5 by the printing method can be easily used as the conductor pattern layer 1. Become. Examples of the printing method include screen printing, intaglio printing, flexographic printing, and the like.
The laminated surface can be any one or two of the front and back surfaces of the conductor pattern layer 1.

(Transparent substrate)
As the transparent substrate 1, an inorganic plate such as a transparent resin sheet, glass or ceramics can be used. Examples of the resin of the resin sheet include polyester resins such as polyethylene terephthalate, acrylic resins such as polymethyl methacrylate, polyolefin resins such as cycloolefin polymers, cellulose resins such as triacetyl cellulose, polycarbonate resins, and the like. It is. Among these, a biaxially stretched polyethylene terephthalate sheet is a suitable material. The thickness of the resin sheet is usually 12 to 500 μm, preferably 25 to 200 μm, from the viewpoints of handleability and cost, but is not particularly limited. The resin sheet may be in the form of a web or a sheet.

(Conductive composition layer)
The conductive composition layer can be formed by printing ink composed of a conductive composition containing conductive particles and a resin binder. Conductive particles are coated with highly conductive metal such as gold or silver on the surface of highly conductive metal (these metals alone or alloys) particles such as silver, copper, aluminum, tin, nickel, or resin particles or non-metallic inorganic particles. Metal-coated particles or graphite particles. In addition, as the resin binder, a thermoplastic resin, a thermosetting resin, an ionizing radiation curable resin, or the like is used alone or in combination as a resin. A thermoplastic polyester resin, a thermoplastic acrylic resin, or the like is used as the thermoplastic resin, and a thermosetting polyester resin, a thermosetting acrylic resin, a thermosetting urethane resin, or the like is used as the curable resin. In addition, as the ionizing radiation curable resin, a composition containing at least one of monomers and prepolymers that are polymerized and cured by ionizing radiation and the like is used. As the monomer or prepolymer, a radical polymerizable or cationic polymerizable compound can be used. Among these, ionizing radiation curable resins using acrylate compounds are typical. As the ionizing radiation for curing the ionizing radiation curable resin, ultraviolet rays or electron beams are usually used.

As the conductive composition layer, a layer using the “pulling primer type intaglio printing method” disclosed in the pamphlet of International Publication No. 2008/149969 is preferable in terms of higher definition. In this intaglio printing method, a primer layer made of ionizing radiation curable resin or the like that pulls out the ink (conductive paste) filled in the recesses of the intaglio plate surface and promotes the transfer to the substrate is printed during printing. In this method, the material is allowed to act in a fluid state and solidified on the plate surface, and then released and printed. This primer layer has a cross-sectional shape that is not found in other printing methods, and has a shape where the thickness of the conductive composition layer is larger than that of the non-formation portion.
This primer layer is a transparent resin layer, which can be thermoplastic resin, curable resin, etc., and curable resin can be thermosetting resin, ionizing radiation curable resin, etc. An ionizing radiation curable resin that is cured by, for example, is preferably used.

[C] Composite laminate:
The composite laminate 30 of the present invention includes the above-described electromagnetic wave shielding material 10 of the present invention and at least one functional layer 20 laminated thereon, as in the embodiment illustrated in FIG. By laminating the functional layer 20, an optical member in which the electromagnetic wave shielding function by the electromagnetic wave shielding material 10 and the function of the functional layer are combined can be obtained. The laminated surface of the functional layer 20 is a surface on the side of the observer V of the electromagnetic wave shielding material 10 shown in FIG. 15A, or a surface opposite to the observer V side as shown in FIG. Although not shown, any of these two surfaces may be used.
As the functional layer 20, various conventionally known functional layers in the optical filter can be appropriately employed. The functional layer 20 includes an optical functional layer and a non-optical functional layer. Examples of the optical functional layer include a near-infrared absorbing layer, a neon light absorbing layer, a toning layer, an ultraviolet absorbing layer, and an antireflection layer (any of antiglare, antireflection, antiglare and antireflection). The so-called microlouver layer described in Japanese Patent No. 272161 and the like can be mentioned. Examples of the non-optical functional layer include a hard coat layer, an impact resistant layer (impact absorbing layer), an antifouling layer, an antistatic layer, an antibacterial layer, An eaves layer etc. are mentioned. The contents of these functional layers can be conventionally known.
The composite laminate 30 may be one in which one or a plurality of functions are combined in addition to the electromagnetic wave shielding function by these functional layers. In the case where a plurality of functions are provided by the functional layer, one layer may be provided for each function, or a plurality of functions may be provided in one layer.

[D] Image display device:
The image display apparatus according to the present invention, as in the embodiment illustrated in FIG. 16, is arranged as described above and is disposed on the image display panel 40 and the front surface 40a side that is the viewer V side of the image display panel 40. The image display device 100 includes at least the electromagnetic wave shielding material 10 or the composite laminate 30. In addition to the image display panel 40, the image display device 100 includes a housing (cabinet), input / output components, and the like, and, for example, a tuner in the case of a television receiver, according to the use of the image display device. Various known parts are provided. These other components are not particularly limited, and depend on the application.
The image display panel 40 is a display panel capable of displaying a planar image such as a plasma display panel, a liquid crystal panel, or an EL (electroluminescence) panel. Further, a CRT with a flat display surface may be used. The image display panel 40 may include various circuits such as a display drive circuit, wiring between the drive circuit and the image display panel main body, a chassis, a frame, and the like for integrating them. Therefore, the image display panel 40 can also be called a “display module” or a “panel module”.

  In the drawing, the electromagnetic wave shielding material 10 or the composite laminate 30 and the image display panel 40 are configured to be separated and independent from each other with an air layer interposed therebetween. The total thickness may be reduced by the integration.

  As described above, the image display device 100 using the electromagnetic wave shielding material 10 or the composite laminate 30 eliminates the occurrence of moiré due to the periodic arrangement of the conductor pattern layer 1 and the density of the arrangement. Therefore, it is possible to obtain an image display device that eliminates unevenness of light and darkness and balances both of these, and prevents a decrease in contrast due to external light.

[E] Application:
The electromagnetic wave shielding material 10 or the composite laminate 30 according to the present invention is suitable for use on the front side on the observer side of various image display panels. As the image display panel, for example, a plasma display panel, a liquid crystal display panel, an electroluminescent panel, electronic paper, and a cathode ray tube may be used.
The electromagnetic wave shielding material 10 or the composite laminate 30 according to the present invention is attached to a window, a transparent door, a transparent wall surface or a partition of a house, a store, a school, an office, a hospital or a clinic, etc. It can also be used to shield unwanted electromagnetic waves from one to the other, from the other to one, or both.
The image display apparatus 100 according to the present invention including the electromagnetic wave shielding material 10 or the composite laminate 30 includes a television receiver, a measuring device and instruments, office equipment, medical equipment, computer equipment, a telephone, an electronic signboard, and a game. It is suitable as an image display device such as a device or a digital photo frame.

DESCRIPTION OF SYMBOLS 1 Conductor pattern layer 1P Mesh pattern 2 Dark color layer 3 Groove-shaped recessed part 4 Needle-shaped metal 5 Transparent base material 10 Electromagnetic wave shielding material 20 Functional layer 30 Composite laminated body 40 Image display panel 50 Conventional electromagnetic wave shielding material 100 Image display apparatus A Opening B Branch point BP Generating point L Boundary line segment Lt Line part (set of boundary line segment)
S Unit pattern area V Observer

Claims (5)

An electromagnetic wave shielding material having a conductor pattern layer and a dark color layer formed on at least one of the front and back surfaces thereof,
The shape of the conductor pattern layer in plan view includes a mesh pattern that defines a large number of openings, and the mesh pattern is formed from a number of boundary lines that extend between two branch points to define the opening region. The average value N of the number of boundary line segments extending from one branch point is 3.0 ≦ N <4.0, and there is a direction in which the opening regions are arranged at a constant repetition period. A pattern that includes a non-
The dark color layer has a groove-like recess on the surface, and has a needle-like metal protruding on the surface on which the groove-like recess is formed.
Electromagnetic wave shielding material.   The electromagnetic wave shielding material according to claim 1, comprising at least a pentagon and a hexagon as a planar view shape of the opening.   The composite laminate according to claim 1, wherein a transparent substrate is further laminated on the conductor pattern layer on which the dark color layer is formed.   Furthermore, the electromagnetic wave shielding material in any one of Claims 1-3 in which the functional layer is laminated | stacked. An image display device comprising: an image display panel; and the electromagnetic wave shielding material according to any one of claims 1 to 3 or the composite laminate according to claim 4 disposed on a front surface of the image display panel.