Conductive films and display devices

Abstract

To provide a conductive film with excellent transparency. [Solution] A conductive film comprising a resin layer disposed on a substrate and having trenches opening on the surface opposite to the substrate, and a conductor provided in the trench, wherein the substrate includes a plurality of fillers protruding toward the resin layer, the resin layer includes a plurality of inorganic particles, and when viewed from the thickness direction of the conductive film, at least a portion of the plurality of inorganic particles overlaps with the plurality of fillers.

Description

Technical Field

[0001] The present disclosure relates to a conductive film and a display device.

Background Art

[0002] On the surface of a touch panel or a display, a transparent antenna mounted with a conductive substrate (conductive film) having transparency and conductivity may be implemented. In recent years, along with the enlargement and diversification of touch panels and displays, conductive films are required to have high transparency, high conductivity, as well as flexibility.

[0003] For example, Patent Document 1 discloses a transparent conductive film that includes a transparent film having grooves on its surface and a conductive part present in the grooves, wherein the conductive part is composed of a siloxane layer containing palladium and a conductive material, and the line width of the conductive layer and the ratio of height to the line width fall within specific ranges.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] One aspect of the present disclosure provides a conductive film with excellent transparency. Another aspect of the present disclosure provides a display device with excellent visibility.

Means for Solving the Problems

[0006] One aspect of the present disclosure provides a conductive film comprising a substrate, a resin layer disposed on the substrate and having trenches opening to the surface opposite to the substrate, and conductors provided in the trenches, wherein the substrate includes a plurality of fillers protruding toward the resin layer, the resin layer includes a plurality of inorganic particles, and when viewed from the thickness direction of the conductive film, at least a portion of the plurality of inorganic particles overlaps with the plurality of fillers.

[0007] Another aspect of this disclosure is to provide a display device comprising the conductive film described above. [Effects of the Invention]

[0008] According to one aspect of this disclosure, a conductive film with excellent transparency is provided. According to another aspect of this disclosure, a display device with excellent visibility is provided. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic plan view showing a conductive film according to one embodiment. [Figure 2] Figure 2 is a cross-sectional view taken along the line II-II in Figure 1. [Figure 3] Figure 3 is a magnified view of a portion of the conductive film shown in Figure 2. [Figure 4] Figure 4 is a magnified view of a portion of the conductive film shown in Figure 2. [Figure 5] Figure 5 is a schematic cross-sectional view showing the manufacturing method of the conductive film shown in Figure 1. [Figure 6] Figure 6 is a schematic cross-sectional view showing the manufacturing method of the conductive film shown in Figure 1. [Figure 7] Figure 7 is a cross-sectional view showing one embodiment of the container. [Modes for carrying out the invention]

[0010] This disclosure is not limited to the following examples.

[0011] <Conductive film> A conductive film according to one embodiment of the present disclosure will be described below. Figure 1 is a schematic plan view showing a conductive film according to the present embodiment. Figure 2 is a cross-sectional view taken along the line II-II in Figure 1. In other words, Figure 2 is a cross-section of the conductive film 100 in the thickness direction. The conductive film 100 shown in Figures 1 and 2 comprises a substrate 10, a resin layer 20 disposed on the substrate 10 and having a trench 25 opening to the surface opposite to the substrate 10, and a conductor 50 provided in the trench 25. The resin layer 20 has a first layer 30 and a second layer 40 from the substrate 10 side. The substrate 10 and the resin layer 20 are in direct contact. The trench 25 penetrates the resin layer 20 in the thickness direction. The conductive film 100 can be made thinner compared to the case where another resin layer is provided between the substrate 10 and the resin layer 20. Therefore, the resulting display device can be made smaller.

[0012] In the examples shown in Figures 1 and 2, a mesh-like pattern is formed by the intersection of multiple linear trenches 25 extending along each of the two directions. The conductors 50 within the trenches 25 also form a mesh-like pattern. Conductors 50 having a mesh-like pattern can function well, for example, as a radiating element of an antenna. The trenches 25 and conductors 50 are provided over a portion of the surface 10a of the substrate 10.

[0013] Figure 3 is an enlarged view of region α1 shown in Figure 2. Figure 4 is an enlarged view of region α2 shown in Figure 2. The shape (observation area) of regions α1 and α2 can be rectangular (including square). The size of the rectangle may be, for example, 1000 nm × 1000 nm. Region α1 includes the interface between the substrate 10 and the resin layer 20. Region α2 includes the interface between the substrate 10 and the conductor 50. For example, there may be one region α1 in the cross-section. For example, there may be one region α2 in the cross-section. Regions α1 and α2 can be observed using a transmission electron microscope (TEM) at an accelerating voltage of 200 kV and a magnification of 100,000 times.

[0014] Hereinafter, description will be given with the thickness direction of the conductive film 100 defined as direction D1, and the direction orthogonal to direction D1 in the cross section in the thickness direction of the conductive film 100 defined as direction D2.

[0015] (Base material) The base material 10 includes a resin portion 13 and a filler 11. The base material 10 is in the form of a film. In the region α1, the filler 11 protrudes toward the resin layer 20. "The filler 11 protrudes toward the resin layer 20" means that a part of the filler 11 is present in the resin layer 20 and a part thereof is present in the base material 10. In the region α2, the filler 11 protrudes toward the conductor 50. "The filler 11 protrudes toward the conductor 50" means that a part of the filler 11 is present in the conductor 50 and a part thereof is present in the base material 10.

[0016] The shape of the filler 11 may be particulate. The filler 11 may be an inorganic filler or an organic filler. The filler 11 may be insulating. Examples of the filler 11 include silica filler particles and zirconia filler particles.

[0017] The average particle diameter of the filler 11 may be 20 nm or more, 30 nm or more, or 40 nm or more, and may be 200 nm or less, 180 nm or less, or 160 nm or less. In the region α1, the average particle diameter of the filler 11 is calculated by respectively measuring the maximum lengths of the fillers protruding toward the resin layer 20 and averaging the measured values. In the region α2, it is calculated by respectively measuring the maximum lengths of the fillers protruding toward the conductor 50 and averaging the measured values.

[0018] In region α1, filler 11 may constitute a filler group 12 consisting of multiple fillers. In this case, the filler group 12 acts as an anchor, and the adhesion between the substrate 10 and the resin layer 20 tends to improve. As shown in Figure 3, fillers 11a to 11c constitute filler group 12a. Fillers 11d to 11f constitute filler group 12b. Filler group 12 is a collection of fillers 11 where the distance between adjacent fillers 11 is shorter than the maximum particle size of the filler 11. The distance between adjacent fillers 11 is the distance between fillers 11 on the imaginary line B1. The imaginary line B1 is a straight line in region α1 connecting one end b1 to the other end b2 of the interface between the substrate 10 and the resin layer 20. The maximum particle size of filler 11 is the particle size of the filler 11 with the longest particle size among the fillers 11 observed in region α1. Of the fillers 11a to 11f observed in region α1, filler 11a has the longest particle size. That is, the distance g1 between filler 11a and filler 11b is smaller than the particle size of filler 11a. The distance g2 between filler 11b and filler 11c is smaller than the particle size of filler 11a. The distance g3 between filler 11d and filler 11e is smaller than the particle size of filler 11a. The distance g4 between filler 11e and filler 11f is smaller than the particle size of filler 11a. On the other hand, the distance between filler 11c and filler 11d is larger than the particle size of filler 11a, so filler 11d is not included in the filler group 12a, and filler 11c is not included in the filler group 12b.

[0019] In region α2, the filler 11 may constitute a filler group 12. In this case, the filler group 12 acts as an anchor, and the adhesion between the substrate 10 and the conductor 50 tends to improve.

[0020] In region α1, the total area of ​​the portions of the multiple fillers 11 located within the resin layer 20 may be smaller than the total area of ​​the portions of the multiple fillers 11 located within the substrate 10. In this case, the adhesion between the substrate 10 and the resin layer 20 tends to improve.

[0021] Examples of materials for the resin part 13 include polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate (PEN), cycloolefin polymer (COP), polymethyl methacrylate (PMMA), or polyimide (PI).

[0022] The substrate 10 may be transparent. The substrate 10 may have light transmittance to the extent required when the conductive film 100 is incorporated into a display device, for example. Specifically, the total light transmittance of the substrate may be 90 to 100%. The haze of the substrate may be 0 to 5%.

[0023] The thickness of the substrate 10 may be 10 μm or more, 20 μm or more, or 35 μm or more, and may be 500 μm or less, 200 μm or less, or 100 μm or less.

[0024] (Resin layer) The first layer 30 is a resin layer containing the first resin portion 33 and a plurality of inorganic particles 31. Viewed from direction D1, at least a portion of the plurality of inorganic particles 31 overlap with the plurality of fillers 11. This overlap of at least a portion of the plurality of inorganic particles 31 with the plurality of fillers 11 suppresses the inorganic particles 31 from hindering light transmission. As a result, the conductive film 100 has excellent transparency.

[0025] The first resin part 33 may be transparent. The first resin part 33 may be a cured product of a photocurable resin or a thermosetting resin. Examples of photocurable resins or thermosetting resins include acrylic resins, amino resins, cyanate resins, isocyanate resins, polyimide resins, epoxy resins, oxetane resins, polyesters, allyl resins, phenolic resins, benzoxazine resins, xylene resins, ketone resins, furan resins, COPNA resins, silicon resins, dicyclopentadiene resins, benzocyclobutene resins, episulfide resins, enethiol resins, polyazomethine resins, polyvinyl benzyl ether compounds, acenaphthylene, and UV-curable resins containing functional groups that undergo polymerization reactions under ultraviolet light, such as unsaturated double bonds, cyclic ethers, and vinyl ethers. These photocurable resins or thermosetting resins may be used individually or in combination of two or more types.

[0026] The inorganic particles 31 may be one or more inorganic particles selected from Pd, Cu, Ni, Co, Au, Ag, Rh, Pt, In, and Sn, and may also contain Pd. The inorganic particles 31 may be a single type or a combination of two or more types of inorganic particles.

[0027] The shape of the inorganic particles 31 is not particularly limited and may be spherical, ellipsoidal, polyhedral, plate-like, flaky, columnar, etc.

[0028] The average particle size of the inorganic particles 31 may be 10 nm or less, 8 nm or less, or 5 nm or less, from the viewpoint of excellent transparency of the conductive film 100. The average particle size of the inorganic particles 31 may also be, for example, 0.1 nm or more, 0.5 nm or more, or 1 nm or more. The average particle size of the inorganic particles 31 is calculated by measuring the maximum length of each inorganic particle 31 present in region α1 and averaging them.

[0029] The thickness of the first layer 30, or the thickness of the first resin portion 33, may be, for example, 10 nm or more, 15 nm or more, or 20 nm or more, and may also be 300 nm or less, 250 nm or less, or 200 nm or less.

[0030] The second layer 40 is a resin layer mainly composed of the second resin portion 43. The second layer 40 may or may not contain inorganic particles. The second resin portion 43 may be transparent. The second resin portion 43 may be made of a different material from the first resin portion 33, or it may be made of the same material. The second resin portion 43 may be a cured product of a photocurable resin or a thermosetting resin. Examples of photocurable or thermosetting resins include acrylic resins, amino resins, cyanate resins, isocyanate resins, polyimide resins, epoxy resins, oxetane resins, polyesters, allyl resins, phenolic resins, benzoxazine resins, xylene resins, ketone resins, furan resins, COPNA resins, silicon resins, dicyclopentadiene resins, benzocyclobutene resins, episulfide resins, enethiol resins, polyazomethine resins, polyvinyl benzyl ether compounds, acenaphthylene, and UV-curable resins containing functional groups that undergo polymerization reactions under ultraviolet light, such as unsaturated double bonds, cyclic ethers, and vinyl ethers. These photocurable or thermosetting resins may be used individually or in combination of two or more types.

[0031] The thickness of the second layer 40, or the thickness of the second resin part 43, may be, for example, 1 μm or more, 1.5 μm or more, or 2 μm or more, and may also be 5 μm or less, 4 μm or less, or 3 μm or less.

[0032] The thickness of the resin layer 20 may be, for example, 1 μm or more, 1.5 μm or more, or 2 μm or more, and may also be 5 μm or less, 4 μm or less, or 3 μm or less.

[0033] The trench 25 opens to the surface opposite to the substrate 10 and extends onto the resin layer 20. The trench 25 includes portions that form a pattern corresponding to the pattern of the conductor 50. As shown in Figure 2, the width of the trench 25 may narrow from the side of the resin layer 20 away from the substrate 10 towards the substrate 10, or the width of the trench 25 may be substantially constant in the depth direction.

[0034] The width and depth of the trench 25 may generally be substantially the same as the width and thickness of the conductor 50, respectively. That is, the height of the surface 20a of the resin layer 20 from the surface 10a of the base material 10 may be the same as the height of the surface of the conductor 50 from the surface 10a of the base material 10. The height of the surface 20a of the resin layer 20 from the surface 10a of the base material 10 may be lower or higher than the height of the surface of the conductor 50 from the surface 10a of the base material 10. In this specification, the width of the trench 25 means the maximum width in direction D2, and the depth of the trench 25 means the maximum depth in direction D1. The ratio of the depth of the trench 25 to the width of the trench 25 may be the same as the aspect ratio of the conductor 50, which will be described later.

[0035] (Area R) Region R is the region that includes the interface between the substrate 10 and the resin layer 20. Region R is the region enclosed by the sides L1 and L2 of the rectangular region α1 that are parallel to direction D1, and the virtual lines L3 and L4 that are parallel to virtual line B1. Virtual lines L3 and L4 are provided such that virtual line B1 is located in the center. The distance between virtual lines L3 and L4 may be, for example, 100 nm.

[0036] Region R comprises a first region r1 containing the filler group 12 and a second region r2 not containing the filler group 12. Because region R comprises both the first region r1 and the second region r2, the filler group 12 acts as an anchor, tending to improve adhesion between the substrate 10 and the resin layer 20.

[0037] As shown in Figure 3, region R has two first regions r1a and r1b, and two second regions r2a to r2c. In other words, region R has two first regions r1 and three second regions r2. The first region r1a contains the filler group 12a. The first region r1a is the region enclosed by virtual lines L3 to L6. The first region r1b contains the filler group 12b. The first region r1b is the region enclosed by virtual lines L3, L4, L7 and L8. The second region r2a is the region enclosed by edge L1 and virtual lines L3 to L5. The second region r2b is the region enclosed by virtual lines L3, L4, L6 and L7. The second region r2c is the region enclosed by edge L2 and virtual lines L3, L4 and L8. Virtual line L5 is a straight line extending from the end of filler group 12a on the filler 11a side in direction D2 to direction D1. Virtual line L6 is a straight line extending from the end of filler group 12a on the filler 11c side in direction D2 to direction D1. Virtual line L7 is a straight line extending from the end of filler group 12b on the filler 11d side in direction D2 to direction D1. Virtual line L8 is a straight line extending from the end of filler group 12b on the filler 11f side in direction D2 to direction D1.

[0038] The lengths of the first regions r1a and r1b along direction D2 may be, for example, 50 nm or more, 100 nm or more, or 150 nm or more, and may be 400 nm or less, 350 nm or less, or 300 nm or less.

[0039] The lengths of the second region r2a to r2c along direction D2 may be 50 nm or more, 80 nm or more, or 100 nm or more, respectively. In this case, there is a tendency to suppress interference with light transmission. The lengths of the second region r2 along direction D2 may be 1000 nm or less, 900 nm or less, or 800 nm or less, respectively.

[0040] Region R may include a 100nm x 100nm rectangular region as a second region. Including a 100nm x 100nm rectangular region as a second region in region R tends to suppress interference with light transmission.

[0041] The region including the interface may have a first region r1 and a second region r2 that satisfy the following formula (1). In this case, the inorganic particles 31 are suppressed from hindering light transmission. As a result, the conductive film 100 becomes even more transparent.

[0042] n1 / s1>n2 / s2...Equation (1) [In the formula, n1 represents the number of inorganic particles in the first region r1, n2 represents the number of inorganic particles in the second region r2, and s1 represents the area of ​​the first region r1 (unit: nm)] 2 ) shows that s2 is the area of ​​the second region r2 (unit: nm) 2 ) indicates.

[0043] n1 is the number of inorganic particles in one first region r1. n2 is the number of inorganic particles in one second region r2. s1 is the area of ​​one first region r1. s2 is the area of ​​one second region r2. The values ​​of s1 and s2 may be approximately the same. s1 and s2 are, for example, 2500 nm. 2 More than 90000nm 2 The following is acceptable:

[0044] In Figure 3, the first region r1a and the second region r2a satisfy equation (1). The first region r1a and the second region r2b satisfy equation (1). The first region r1a and the second region r2c satisfy equation (1). The first region r1b and the second region r2a satisfy equation (1). The first region r1b and the second region r2b satisfy equation (1). The first region r1b and the second region r2c satisfy equation (1). There may be one or more combinations of the first and second regions that satisfy equation (1).

[0045] Some of the multiple inorganic particles 31 may be deposited in the thickness direction of the conductive film to form a deposit. In this case, the inorganic particles 31 are suppressed from hindering light transmission. As a result, the conductive film 100 becomes even more transparent. The deposit may be in contact with the filler 11. In Figure 3, region R has a first region r1, which includes a first region r1a and a first region r1b containing the deposit.

[0046] The thickness of the deposit in the first region r1 may be, for example, 10 nm or more, 15 nm or more, or 20 nm or more, and may be 300 nm or less, 250 nm or less, or 200 nm or less. The thickness of the deposit in the first region r1 is the distance in direction D1 between the edge on the surface 20a side of the inorganic particle 31 constituting the deposit that is closest to the surface 20a of the resin layer 20 and the edge on the surface 20b side of the inorganic particle that is closest to the surface 20b of the resin layer 20. The thicknesses of the deposit in the first regions r1a and r1b are t1a and t1b, respectively.

[0047] The thickness of the sediment contained in the first region r1 may be smaller than the average particle size of the multiple fillers. In this case, the inorganic particles 31 tend to further suppress the obstruction of light transmission. If region R has multiple first regions r1 containing sediment, the thickness of the sediment contained in any one of the first regions r1 may be smaller than the average particle size of the multiple fillers, and the thickness of the sediment contained in multiple first regions r1 may be smaller than the average particle size of the multiple fillers. In Figure 3, the thickness of the sediment contained in the first region r1a (t1a) is smaller than the average particle size of the multiple fillers. The thickness of the sediment contained in the first region r1b (t1b) is smaller than the average particle size of the multiple fillers.

[0048] In the second region r2a to r2c, inorganic particles 31 are dispersed. That is, region R has a second region r2, which consists of the second region r2a to r2c where inorganic particles 31 are dispersed. The thickness of the region where inorganic particles 31 are dispersed is the distance in direction D1 between the edge of the inorganic particle closest to the surface 20a of the resin layer 20 and the edge of the inorganic particle closest to the surface 20b of the resin layer 20. In the second region r2a to r2c, the thickness of the region where inorganic particles 31 are dispersed is t2a to t2c, respectively. Note that in the second region r2a to r2c, there may be some areas where inorganic particles 31 are deposited.

[0049] The thickness of the sediment contained in the first region r1 may be less than the thickness of the region in the second region r2 where inorganic particles exist. In this case, the interference of inorganic particles 31 with light transmission tends to be further suppressed. If region R has multiple first regions r1 containing sediment, the thickness of the sediment contained in any one of the first regions r1 may be less than the thickness of the region in one or more second regions r2 where inorganic particles exist, and the thickness of the sediment contained in multiple first regions r1 may each be less than the thickness of the region in one or more second regions r2 where inorganic particles exist. In Figure 3, the thickness of the sediment contained in the first region r1a (t1a) is less than the thickness of the region in the second region r2a where inorganic particles exist (t2a). The thickness of the sediment contained in the first region r1a (t1a) is less than the thickness of the region in the second region r2b where inorganic particles exist (t2b). The thickness of the sediment in the first region r1a (t1a) is smaller than the thickness of the region containing inorganic particles in the second region r2c (t2c). The thickness of the sediment in the first region r1b (t1b) is smaller than the thickness of the region containing inorganic particles in the second region r2a (t2a). The thickness of the sediment in the first region r1b (t1b) is smaller than the thickness of the region containing inorganic particles in the second region r2b (t2b). The thickness of the sediment in the first region r1b (t1b) is smaller than the thickness of the region containing inorganic particles in the second region r2c (t2c).

[0050] (conductor) The conductor 50 may consist of a single layer of metal plating, or it may consist of multiple layers of metal plating of different metal types. The metal plating for the conductor 50 may include, for example, at least one metal selected from copper, nickel, cobalt, palladium, silver, gold, platinum, and tin, and may also include copper. The conductor 50 may further contain nonmetallic elements such as phosphorus, to the extent that conductivity is maintained.

[0051] When the conductor 50 has a seed layer and an upper metal plating layer, the metal constituting the seed layer and the metal constituting the upper metal plating layer may be the same or different. For example, the seed layer may contain nickel and the upper metal plating layer may contain copper. The upper metal plating layer may consist of a copper plating layer formed on the seed layer and an uppermost layer formed on the copper plating layer that contains gold or palladium.

[0052] The conductor 50 may have a pattern that includes linear portions. The pattern of the conductor 50 may include a plurality of linear portions arranged while extending along a certain direction. The conductor 50 may have a mesh-like pattern that includes linear portions.

[0053] The width of the linear portion of the conductor 50 may be 1 μm or more, 10 μm or more, or 20 μm or more, and may be 90 μm or less, 70 μm or less, or 30 μm or less. In this specification, the width of the linear portion of the conductor 50 refers to the maximum width in the extending direction of the conductor 50. From the viewpoint of improving the transparency of the conductive film 100, the width of the linear portion of the conductor 50 may be 0.3 μm or more, 0.5 μm or more, or 1.0 μm or more, and may be 5.0 μm or less, 4.0 μm or less, or 3.0 μm or less.

[0054] The thickness of the conductor 50 may be 0.1 μm or more, 1.0 μm or more, or 2.0 μm or more, and may be 10.0 μm or less, 5.0 μm or less, or 3.0 μm or less. The width and thickness of the linear portion of the conductor 50 can be adjusted by changing the design of the mold 55, which will be described later, and changing the width and thickness of the trench 25.

[0055] The aspect ratio of the conductor 50 may be, for example, 0.1 or greater, 0.5 or greater, or 1.0 or greater, or it may be 10.0 or less, 7.0 or less, or 4.0 or less. The aspect ratio of the conductor 50 refers to the ratio of the thickness of the conductor 50 to the width of the conductor 50 (thickness / width).

[0056] Although a conductive film according to one embodiment has been described above, the conductive film of this disclosure is not limited to the above embodiment. For example, the conductive film 100 has a first layer 30 and a second layer 40 as the resin layer 20, but the resin layer may be a single layer. Furthermore, the conductive film of this disclosure may further include a hard coat layer on the surface of the substrate opposite to the resin layer.

[0057] (Hard coat layer) The hard coat layer may be transparent. The hard coat layer may be a cured product of a photocurable resin or a thermosetting resin. Examples of photocurable resins or thermosetting resins include acrylic resins, amino resins, cyanate resins, isocyanate resins, polyimide resins, epoxy resins, oxetane resins, polyesters, allyl resins, phenolic resins, benzoxazine resins, xylene resins, ketone resins, furan resins, COPNA resins, silicon resins, dicyclopentadiene resins, benzocyclobutene resins, episulfide resins, enethiol resins, polyazomethine resins, polyvinyl benzyl ether compounds, acenaphthylene, and UV-curable resins containing functional groups that undergo polymerization reactions under ultraviolet light, such as unsaturated double bonds, cyclic ethers, and vinyl ethers. These photocurable resins or thermosetting resins may be used individually or in combination of two or more types.

[0058] The thickness of the hard coat layer may be, for example, 0.05 μm or more, 0.06 μm or more, or 0.07 μm or more, and may also be 3 μm or less, 2 μm or less, or 1.5 μm or less.

[0059] <Method for manufacturing conductive film> The following describes a method for manufacturing a conductive film according to one embodiment of the present disclosure. Figures 5 and 6 are schematic cross-sectional views showing an example of a method for manufacturing the conductive film 100 shown in Figure 1. In the method according to this embodiment, first, as shown in Figure 5(a), a first layer 30 is formed on one surface 10a of a film-like substrate 10. The substrate 10 includes a filler group 12. A substrate 10 having a filler group 12 can be obtained, for example, by applying a solvent containing the fillers to the surface of the substrate when forming the substrate film. The first layer 30 includes inorganic particles 31 and a first resin portion 33.

[0060] The first layer 30 is formed, for example, by a method that includes applying a coating liquid containing a resin component that forms the first resin portion 33, inorganic particles 31, and a solvent onto the substrate 10, and then removing the solvent from the coating film on the substrate 10. By forming the first layer 30 in this way, at least a portion of the inorganic particles 31 overlaps with the plurality of fillers 11 when viewed from direction D1. A portion of the inorganic particles 31 becomes a nucleus material for forming the conductor 50, while the rest remains in the first layer 30. The overlap of at least a portion of the inorganic particles 31 with the plurality of fillers 11 suppresses the inorganic particles 31 from hindering light transmission. As a result, the conductive film 100 has sufficient conductivity while also having excellent transparency. The step in Figure 5(a) may be a step of preparing a laminate comprising the substrate 10 and the first layer 30.

[0061] As shown in Figure 5(b), a coating film 40' of a resin composition containing a resin component that forms the second resin portion 43 is formed on the surface 30a of the first layer 30. The step in Figure 5(b) may also be a step of preparing a laminate comprising the substrate 10, the first layer 30, and the coating film 40' in this order.

[0062] As shown in Figure 5(c) and Figure 6(a), a second layer 40 having trenches 45 is formed by an imprint method using a mold 55 having protrusions 55a. In this step, the mold 55 having protrusions 55a of a predetermined shape is moved in the direction indicated by arrow A to press it into the coating film 40' (Figure 5(c)). The mold 55 may be pressed in until the tip of the protrusions 55a reaches the first layer 30. In this state, the second resin part 43 is cured as necessary. If the second resin part 43 before curing contains a photocurable resin, the second resin part 43 is cured by irradiating it with light such as ultraviolet light. After that, the mold 55 is removed to form a trench 45 having a shape that is the inverse of the shape of the protrusions 55a of the mold 55 (Figure 6(a)). The method for forming the trench 45 is not limited to the imprint method, and for example, the trench 45 may be formed by laser, dry etching, or photolithography. The steps in Figure 5(c) and Figure 6(a) may be steps to form a second layer 40 having a trench 45 in a laminate comprising a base material 10, a first layer 30, and a second layer 40 in that order.

[0063] The mold 55 may be made of quartz, Ni, UV-curable liquid silicone rubber (PDMS), etc. The shape of the protrusion 55a of the mold 55 is designed according to the shape of the trench 25 to be formed.

[0064] As shown in Figure 6(b), the resin portion 33 of the first layer 30 exposed from the bottom surface of the trench 45 is removed. This forms a trench (groove) 35 in the first layer 30. This forms a trench 25 consisting of trench 35 and trench 45. With the removal of the resin portion 33, inorganic particles 31 are exposed on the bottom surface of the trench 25. The first resin portion 33 may be removed by etching, such as dry etching, after removing the mold 55. The step in Figure 6(b) may also be a step of forming a trench 35 that opens on the surface of the first layer 30 opposite to the base material 10 in a laminate comprising a base material 10, a first layer 30, and a second layer 40 in this order.

[0065] As shown in Figure 6(c), a conductor 50 is formed to fill the trench 25. The conductor 50 may be formed by an electroless plating method in which metal plating is grown from the substrate 10. By immersing the laminate on which the trench 25 is formed in an electroless plating solution containing metal ions, the metal plating can be grown from the bottom of the trench 25 to form the conductor 50. By forming the conductor 50 to fill the trench 25, a conductive film 100 can be obtained.

[0066] The electroless plating solution contains ions of the metals that make up the conductor 50. The electroless plating solution may further contain phosphorus, boron, iron, etc.

[0067] The temperature of the electroless plating solution when immersing the laminate in it may be, for example, 40 to 90°C. The immersion time in the electroless plating solution varies depending on the thickness of the conductor 50, but may be, for example, 10 to 30 minutes.

[0068] A conductor having a seed layer and an upper metal plating layer can be formed by a method that includes forming a seed layer (first metal layer) on a substrate 10 and forming an upper metal plating layer (second metal layer) on the seed layer. A laminate with trenches 25 formed on it is immersed in an electroless plating solution for forming the seed layer to form a metal plating as a seed layer on the substrate 10. Subsequently, the laminate having the seed layer can be immersed in an electroless plating solution for forming the upper metal plating layer to form the upper metal plating layer on the seed layer. Before forming the upper metal plating layer, a catalyst may be adsorbed onto the seed layer, and the upper metal plating layer may be formed starting from the catalyst adsorbed on the seed layer. The upper metal plating layer may also be formed by electroplating.

[0069] The thickness of the seed layer may be 10 nm or more, 30 nm or more, or 50 nm or more, and may be 500 nm or less, 300 nm or less, or 100 nm or less.

[0070] <Display device> The following describes a display device according to one embodiment of the present disclosure. Figure 7 is a cross-sectional view of the display device according to this embodiment. The display device 500 shown in Figure 7 comprises an image display unit 60 having an image display area 60S, a conductive film 100, a polarizing plate 70, and a cover glass 80. The conductive film 100, the polarizing plate 70, and the cover glass 80 are laminated in this order from the image display unit 60 side on the image display area 60S side of the image display unit 60. The conductive film 100 is incorporated as a planar transparent antenna. Because the display device 500 is equipped with a conductive film 100, it has excellent visibility. Furthermore, because the adhesion between the substrate 10 and the resin layer 20 is excellent, the display device 500 has excellent durability.

[0071] The display device may be, for example, a liquid crystal display device or an organic EL display device.

[0072] The configuration of the display device is not limited to the form shown in Figure 7 and can be modified as needed. For example, a polarizing plate 70 may be provided between the image display unit 60 and the conductive film 100. The image display unit 60 may be, for example, a liquid crystal display unit. The polarizing plate 70 and cover glass 80 can be those commonly used in display devices. The polarizing plate 70 and cover glass 80 are not necessarily required.

[0073] While display devices were given as an example of devices to which conductive films can be applied, conductive films may also be applied to devices other than display devices. For example, conductive films may be applied to glass in buildings or automobiles as transparent antennas. [Examples]

[0074] This disclosure is not limited to the following embodiments.

[0075] <Manufacturing of conductive films> (Example 1) A conductive film was manufactured by further adding a hard coat layer to the surface of the conductive film shown in Figures 1-4, on the side opposite to the resin layer of the substrate. Specifically, first, polyethylene terephthalate (PET) film (thickness: 100 μm, manufactured by Toyobo Co., Ltd., product name "A4360") was prepared as the substrate.

[0076] A coating solution for forming the first layer was prepared, containing Pd microparticles (average particle size: 5 nm), acrylic resin, and a solvent. The coating solution was applied onto a PET film using a bar coater to form a coating film. The solvent was removed from the coating film using a hot air drying oven. Next, the coating film was cured by irradiating it with ultraviolet light using a UV treatment device. This formed a first layer (thickness: 5 nm) containing Pd microparticles (inorganic particles).

[0077] A coating solution containing acrylic resin and a solvent was prepared for forming a hard coat layer. The coating solution was applied to the side of the PET film opposite the first layer using a bar coater to form a coating film. The solvent was removed from the coating film using a hot air drying oven. Next, the coating film was cured by irradiating it with ultraviolet light using a UV treatment device. This formed a hard coat layer (thickness: 300 nm).

[0078] A coating solution containing acrylic resin and a solvent was prepared for forming a second layer. The coating solution was applied to the surface of the first layer opposite to the PET film to form a coating film. A Ni mold with a protrusion 1 μm wide and 2 μm high was prepared. The mold was pressed into the coating film so that the tip of the protrusion reached the surface of the first layer, and the coating film was irradiated with ultraviolet light to cure it. By removing the mold from the cured coating film, a second layer (thickness: 2 μm) was formed, in which linear trenches (width: 1 μm, height: 2 μm) with a mesh-like pattern were formed, intersecting each other and opening on the surface opposite to the first resin layer, and a laminate was obtained. The first and second layers become resin layers.

[0079] The laminate was placed inside a vacuum chamber, and an ashing treatment was performed on the surface of the second layer of the laminate to remove the resin portion of the first layer so that the PET film was exposed through the trenches in the resin layer.

[0080] The laminated body, after ashing treatment, was immersed in an electroless plating solution to grow the Cu plating, forming a Cu conductor within the trench. This resulted in a conductive film comprising a hard coat layer, a substrate, a first layer, and a second layer in that order.

[0081] (Example 2) A conductive film was obtained in the same manner as in Example 1, except that the thickness of the first layer was set to 10 nm.

[0082] (Example 3) A conductive film was obtained in the same manner as in Example 1, except that the thickness of the first layer was set to 50 nm.

[0083] (Example 4) A conductive film was obtained in the same manner as in Example 1, except that the thickness of the first layer was set to 100 nm.

[0084] <Observation of the cross-section> (Examples 1-4) For each example of conductive film, the cross-section along the thickness direction was observed. A TEM (JEOL, model name "JEM-2100F") was used for observation. The acceleration voltage was 100kV and the magnification was 100,000x. The observation area was a rectangular region α1 (1000nm × 1000nm) including the interface between the substrate and the resin layer.

[0085] The following was confirmed for the conductive films of Examples 1 to 4: Specifically, it was confirmed that the filler protrudes toward the first layer in region α1. It was also confirmed that at least a portion of the multiple inorganic particles overlap with the multiple fillers when viewed from the thickness direction of the conductive film. Furthermore, it was confirmed that region R (1000 nm × 1000 nm), which includes the interface between the substrate and the resin layer, has a first region containing the filler group and a second region not containing the filler group. It was confirmed that region R includes a rectangular region of 100 nm × 100 nm as the second region. It was also confirmed that region R has a first region and a second region that satisfy the above formula (1). Furthermore, it was confirmed that at least a portion of the multiple inorganic particles are deposited in the thickness direction of the conductive film, forming deposits. It was also confirmed that the average particle size of the multiple inorganic particles is smaller than the average particle size of the multiple fillers. Furthermore, region R has a first region which includes a deposit formed by the deposition of at least some of the multiple inorganic particles in the thickness direction of the conductive film, and it was confirmed that the thickness of the deposit in this region is smaller than the average particle size of the multiple fillers. Region R also has a second region which includes a region in which at least some of the multiple inorganic particles are dispersed, and it was confirmed that the thickness of the deposit is smaller than the thickness of the region in the second region in which the inorganic particles are present. In addition, in region α1, it was confirmed that the total area of ​​the portions of the multiple fillers present within the resin layer is smaller than the total area of ​​the portions of the multiple fillers present within the substrate.

[0086] In addition, a rectangular region α2 (1000 nm × 1000 nm) including the interface between the substrate and the conductor was observed in the same manner as region α1. For the conductive films of Examples 1 to 4, it was confirmed that the filler protruded toward the conductor in region α2.

[0087] <Evaluation of Visibility> (Examples 1-4) The total light transmittance of each conductive film was measured using a haze meter (manufactured by Nippon Denshoku Industries, device name "NDH-8000"). The total light transmittance of the conductive films in Examples 1 to 4 was 85% or higher. A total light transmittance of 85% or higher indicates excellent transparency. Furthermore, display devices equipped with conductive films have excellent visibility.

[0088] One aspect of this disclosure relates to the following [1] to

[12] . [1] Substrate and A resin layer placed on a substrate and having a trench opening on the surface opposite to the substrate, A conductor provided in the trench, A conductive film comprising, The substrate contains multiple fillers that protrude toward the resin layer. The resin layer contains multiple inorganic particles, A conductive film in which, when viewed from the thickness direction of the conductive film, at least some of the multiple inorganic particles overlap with the multiple fillers. [2] The conductive film according to [1], wherein in a cross-section in the thickness direction of the conductive film, the region including the interface between the substrate and the resin layer comprises a first region including a group of fillers consisting of a plurality of fillers and a second region not including a group of fillers. [3] The conductive film according to [2], wherein the region including the interface includes a second region, which is a rectangular region of 100 nm × 100 nm. [4] The conductive film according to [2] or [3], wherein the region including the interface has the first region and the second region satisfying the following formula (1). n1 / s1>n2 / s2...Equation (1) [In the formula, n1 represents the number of inorganic particles in the first region, n2 represents the number of inorganic particles in the second region, and s1 represents the area of ​​the first region (unit: nm)] 2 ) represents the area of ​​the second region (unit: nm) where s2 is the area of ​​the second region. 2 ) indicates. [5] A conductive film according to any one of [1] to [4], wherein at least a portion of the multiple inorganic particles are deposited in the thickness direction of the conductive film to form a deposit. [6] A conductive film according to any one of [1] to [5], wherein the average particle size of multiple inorganic particles is smaller than the average particle size of multiple fillers. [7] The region including the interface has, as a first region, a region including a deposit formed by the deposition of at least a portion of the plurality of inorganic particles in the thickness direction of the conductive film, A conductive film according to any one of [2] to [6], wherein the thickness of the deposit is smaller than the average particle size of the multiple fillers. [8] The region including the interface has, as a first region, a region including a deposit formed by the deposition of at least a portion of a plurality of inorganic particles in the thickness direction of the conductive film, The region containing the interface has a second region in which at least some of the multiple inorganic particles are dispersed. A conductive film according to any one of [2] to [6], wherein the thickness of the deposit is smaller than the thickness of the region in the second region where inorganic particles exist. [9] A conductive film according to any one of [1] to [8], wherein, in a cross-section in the thickness direction of the conductive film, the total area of ​​the portions of the fillers located within the resin layer is less than the total area of ​​the portions of the fillers located within the substrate.

[10] A conductive film according to any one of [1] to [9], comprising a filler protruding toward a conductor.

[11] The trench is formed in a mesh-like manner, A conductive film according to any of [1] to

[10] , wherein the conductor forms a mesh-like pattern. A display device comprising a conductive film as described in any of

[12] [2] to

[11] . [Explanation of symbols]

[0089] 10...Substrate, 11...Filler, 12...Filler group, 20...Resin layer, 25...Trench, 31...Inorganic particles, 50...Conductor, 100...Conductive film, 500...Display device, r1...First region, r2...Second region.

Claims

1. Substrate and A resin layer disposed on the substrate and having a trench opening on the surface opposite to the substrate, A conductor provided in the trench, A conductive film comprising, The substrate includes a plurality of fillers protruding toward the resin layer, The resin layer contains a plurality of inorganic particles, A conductive film in which, when viewed from the thickness direction of the conductive film, at least a portion of the plurality of inorganic particles overlaps with the plurality of fillers.

2. The conductive film according to claim 1, wherein in a cross-section of the conductive film in the thickness direction, the region including the interface between the substrate and the resin layer has a first region including a filler group consisting of a plurality of fillers and a second region not including the filler group.

3. The conductive film according to claim 2, wherein the region including the interface includes a rectangular region of 100 nm × 100 nm as the second region.

4. The conductive film according to claim 2, wherein the region including the interface has the first region and the second region satisfying the following formula (1). n1 / s1>n2 / s2...Formula (1) [In the formula, n1 represents the number of inorganic particles present in the first region, n2 represents the number of inorganic particles present in the second region, and s1 represents the area of ​​the first region (unit: nm)] ２ ) represents the area of ​​the second region (unit: nm) ２ ) indicates.

5. The conductive film according to claim 1, wherein at least a portion of the plurality of inorganic particles are deposited in the thickness direction of the conductive film to form a deposit.

6. The conductive film according to claim 1, wherein the average particle size of the plurality of inorganic particles is smaller than the average particle size of the plurality of fillers.

7. The region including the interface has, as the first region, a region including a deposit formed by the deposition of at least a portion of the plurality of inorganic particles in the thickness direction of the conductive film, The conductive film according to claim 2, wherein the thickness of the deposit is smaller than the average particle size of the plurality of fillers.

8. The region including the interface has, as the first region, a region including a deposit formed by the deposition of at least a portion of the plurality of inorganic particles in the thickness direction of the conductive film, The region including the interface has a second region in which at least a portion of the plurality of inorganic particles are dispersed. The conductive film according to claim 2, wherein the thickness of the deposit is smaller than the thickness of the region in the second region in which the inorganic particles exist.

9. The conductive film according to claim 1, wherein, in a cross-section of the conductive film in the thickness direction, the total area of ​​the portions of the plurality of fillers located within the resin layer is smaller than the total area of ​​the portions of the plurality of fillers located within the substrate.

10. The conductive film according to claim 1, wherein the substrate includes a filler that protrudes toward the conductor.

11. The trench is formed in a mesh-like manner. The conductive film according to claim 1, wherein the conductor forms a mesh-like pattern.

12. A display device comprising a conductive film according to any one of claims 1 to 11.

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