JP2011034806A - Transparent conductive film with superior suitability for laminating, and touch panel using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent conductive film which does not produce gas bubbles upon laminating, or has superior suitability for laminating, and to provide a touch panel using the same. <P>SOLUTION: The transparent conductive film includes a film substrate, a transparent electrode pattern having a transparent conductive film formed on one side of the film substrate, and a thick film circuit pattern made of a material of lower resistance than the transparent conducting film, routed over the periphery of the film substrate on which the transparent electrode pattern is formed, and connected to an end portion of the transparent electrode pattern. The thick film circuit pattern has a thickness of 0.05-100 μm, and has at least one of the line edges formed into a serrated shape. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transparent conductive film used for a touch panel and the like and a touch panel using the same.

  Conventionally, the film substrate, a transparent electrode pattern made of a transparent conductive film formed on one side of the film substrate, and the peripheral portion on the film substrate on which the transparent electrode pattern is formed are routed to the There is known a transparent conductive film including a thick film circuit pattern made of a material having a resistance lower than that of the transparent conductive film, which is connected to an end of the transparent electrode pattern (see Patent Document 1).

  And although the portable information device carrying a touch panel is used widely, as a touch panel carried in these, there existed a thing of a resistance film system. A resistive film type touch panel consists of two transparent conductive substrates on which transparent conductive films are formed facing each other at a predetermined interval. Both transparent electrode substrates are in contact only with a part touched with a finger, pen, etc. It operates as a switch and can select menus on the display screen or input handwritten characters, for example. In this touch panel, a relatively simple configuration is realized by using the transparent conductive film having the above-described configuration as a transparent conductive substrate and laminating at the peripheral portion. A pressure-sensitive adhesive layer is used for pasting, and the thick film circuit pattern forming region is also covered with the pressure-sensitive adhesive layer.

  In recent years, a capacitive type touch panel mounted on a portable information device has become widespread, and the momentum has surpassed the resistance film type. In the capacitive touch panel, the transparent conductive film having the above-described configuration is used. In this case, the transparent conductive film is entirely bonded to the transparent substrate.

JP 2006-059720 A

  However, in the thick film circuit pattern formation region, a step corresponding to the thickness of the thick film circuit pattern occurs between the thick film circuit pattern and its adjacent portion. Therefore, when a touch panel is obtained by covering the region where the thick film circuit pattern is formed with the pressure sensitive adhesive layer, the pressure sensitive adhesive layer has an air gap between the thick film circuit pattern and the side wall due to this step. , And bubbles are generated. Even if the bubbles are stuck together under pressure, they move only along the sidewalls of the thick film circuit pattern and do not disappear, leaving the bubbles remaining in the bent part of the thick film circuit pattern, resulting in the following problems. .

  First, if these bubbles are gathered by being pressed with time, for example, when the touch panel is stored or transported, a bad appearance such as swelling on the outer surface of the touch panel is caused.

  In addition, the pressure-sensitive adhesive layer is not adhered to the portion where bubbles are present, and the bonding force is reduced accordingly.

  Further, the thick film circuit pattern in the portion where bubbles are present is liable to deteriorate due to oxidation. In addition, in the case where a plurality of thick film circuit patterns are running side by side, if bubbles exist between the thick film circuit patterns, a short circuit may occur via the bubbles.

  When the touch panel is of the capacitive type, the transparent conductive film is bonded not only to the thick film circuit pattern forming area but also to the transparent electrode pattern forming area. However, when it moves to the transparent electrode pattern formation region over time, there also arises a problem that it is difficult to visually recognize the back display through the touch panel.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a transparent conductive film that does not generate bubbles at the time of bonding, that is, excellent in bonding suitability, and a touch panel using the same. And

  In order to solve the above technical problem, the present invention provides a transparent conductive film having the following constitution and excellent bonding suitability and a touch panel using the transparent conductive film.

  In the first aspect of the present invention, a film substrate, a transparent electrode pattern made of a transparent conductive film formed on one side of the film substrate, and a peripheral portion on the film substrate on which the transparent electrode pattern is formed A thick film circuit pattern made of a material having a resistance lower than that of the transparent conductive film, which is routed and connected to an end portion of the transparent electrode pattern, wherein the thick film circuit pattern is A transparent conductive film excellent in bonding suitability, characterized in that it has a film thickness of 0.05 to 100 μm and at least one line edge is formed in a zigzag shape.

  Moreover, the 2nd aspect of this invention provides the transparent conductive film excellent in the laminating suitability of the 1st aspect whose distance from the said convex part peak of a jagged shape to an adjacent convex part peak is 10-600 micrometers.

  Moreover, the 3rd aspect of this invention provides the transparent conductive film excellent in the laminating suitability of the 2nd aspect whose difference of the peak of the said convex part of a jagged shape and the peak of a recessed part is 2-50 micrometers.

  Moreover, the 4th aspect of this invention provides the transparent conductive film excellent in the bonding ability of the 1st-3rd aspect which is the structure where the said jagged shape is complicated.

  Moreover, the 5th aspect of this invention provides the transparent conductive film excellent in the laminating suitability of the 4th aspect whose said jagged shape is a more complicated and fractal figure shape.

  Moreover, the 6th aspect of this invention provides the transparent conductive film excellent in the bonding ability of the 1st-5th aspect in which the said thick film circuit pattern is formed with the electrically conductive paste.

  Moreover, the 7th aspect of this invention has the area | region where the said thick film circuit pattern runs in parallel 2 or more, and the space | interval of the said thick film circuit pattern which runs parallel is 10-60 micrometers. providing a transparent conductive film excellent in alignment suitability Ha.

  Moreover, the 8th aspect of this invention is further provided with the circuit pattern which consists of a transparent conductive film extended from the said transparent electrode pattern between the said film base material and the said thick film circuit pattern. providing a transparent conductive film excellent in alignment suitability Ha.

  In addition, the ninth aspect of the present invention further provides a transparent conductive film excellent in laminating suitability according to the first to eighth aspects, comprising a pressure-sensitive adhesive layer so as to cover at least the formation region of the thick film circuit pattern. To do.

  The tenth aspect of the present invention provides a touch panel using the transparent conductive film according to the first to ninth aspects.

  According to the present invention, since the line edge of the thick film circuit pattern is formed in a zigzag shape, even when the formation area of the thick film circuit pattern is covered with the pressure-sensitive adhesive layer, it is caused by this step. The pressure adhesive layer does not bite air between the thick film circuit pattern side walls, and bubbles are not generated. This is because the side walls of the thick film circuit pattern are roughened so that air can easily escape through the fine gaps formed by the irregularities on the rough surface. Also, air that could not be removed does not form bubbles because it is finely dispersed in the fine gaps.

  Therefore, since there are no bubbles, there is no problem of causing appearance defects such as swelling on the outer surface of the touch panel.

  Further, since there are no bubbles, the pressure-sensitive adhesive layer is firmly adhered and the laminating force does not decrease. Rather, the unevenness on the side wall of the thick film circuit pattern exerts an anchor effect on the pressure-sensitive adhesive layer, and the transparent conductive film does not peel off due to bending during use of the touch panel or warping of the touch panel in a high temperature and high humidity environment. A strong laminating force can be obtained.

  Furthermore, since there are no bubbles, the thick film circuit pattern is not easily deteriorated by oxidation. In addition, even when a plurality of thick film circuit patterns are running in parallel, there is no possibility that a short circuit will occur between the thick film circuit patterns.

  And when a touch panel is an electrostatic capacitance type, since the bubble which moves to a transparent electrode pattern formation area does not exist, the problem that it becomes difficult to see a back display through a touch panel does not arise.

It is a top view which shows an example of the transparent conductive film which concerns on this invention. It is the elements on larger scale of the thick film circuit pattern drawn around the transparent conductive film of FIG. It is a principal part expanded sectional view which shows an example of the transparent conductive film which concerns on this invention. It is a principal part expanded sectional view which shows the other example of the transparent conductive film which concerns on this invention. It is a principal part expanded sectional view which shows the other example of the transparent conductive film which concerns on this invention. 1 is an exploded perspective view showing an example of a resistive film type touch panel according to the present invention. FIG. It is a disassembled perspective view which shows an example of the capacitive touch panel which concerns on this invention. It is a schematic diagram explaining the state of the line edge of a thick film circuit pattern. 2 is a partially enlarged photograph of a thick film circuit pattern of Example 1. FIG. 2 is a partially enlarged photograph of a thick film circuit pattern of Example 1. FIG. 4 is a partially enlarged photograph of a thick film circuit pattern of Example 2. FIG. 4 is a partially enlarged photograph of a thick film circuit pattern of Example 2. FIG. 4 is a partially enlarged photograph of a thick film circuit pattern of Example 3. FIG. 4 is a partially enlarged photograph of a thick film circuit pattern of Example 3. FIG.

  Next, will be explained with reference to the drawings embodiments of the invention.

  In the transparent conductive film 1 of the invention of FIG. 1, a transparent electrode pattern 61 made of a transparent conductive film is formed on one side of a film substrate 62, and at the peripheral portion on the film substrate 62 on which the transparent electrode pattern 61 is formed. A plurality of thick film circuit patterns 60 are routed and connected to the ends of the transparent electrode pattern 61.

  The material of the film substrate 62 is polyethylene terephthalate, polyethylene, polypropylene, cyclic polyolefin, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, polymethyl acrylate, polystyrene, nitrocellulose, triacetyl cellulose, polycarbonate, polydimethylcyclohexane terephthalate, Examples thereof include ABS resin, polyamide, polyimide, polyethersulfone, polysulfone, polyvinyl acetal, polyetherketone, polyurethane, copolymer resins of these resins, and mixed resins of these resins.

  The transparent electrode pattern 61 is made of a transparent conductive film, and the material thereof is made of transparent oxides such as indium oxide, tin oxide, indium tin oxide, zinc oxide, and aluminum zinc oxide, as well as thiophene-based materials. Examples thereof include transparent conductive polymers.

  For the thick film circuit pattern 60, a material having a resistance lower than that of the transparent conductive film is used. For example, a conductive paste layer made of a binder resin and a conductive material or a thin film layer made of a single conductive material can be used. Examples of the binder resin include resins such as acrylic, polyester, polyurethane, and polyvinyl chloride. The thick film circuit pattern 60 is formed into a predetermined pattern by a method such as painting or ink jet, in addition to screen printing, gravure printing, and offset printing. Alternatively, the solid pattern may be formed by these methods and then patterned.

  Examples of the conductive material include metal powder such as silver, gold, copper, and palladium, metal particles, and metal nanoparticles, and conductive nanofibers such as carbon nanofibers and metal nanowires.

  The thickness of the thick film circuit pattern 60 can be appropriately set in a range of 0.05～100Myuemu. If the thickness is less than 0.05 μm, it is difficult to obtain the conductivity as a routing circuit, and if the thickness is more than 100 μm, it is difficult to form a thin film.

  A feature of the present invention is that at least one line edge of the thick film circuit pattern 60 is formed in a zigzag shape to obtain excellent bonding ability (see FIGS. 2 and 8). That is, since the line edge of the thick film circuit pattern 60 is formed in a zigzag shape, even when the formation area of the thick film circuit pattern 60 is covered with the pressure sensitive adhesive layer 64, the pressure sensitivity is caused by this step. The adhesive layer 64 does not bite air between the side walls of the thick film circuit pattern 60, and bubbles are not generated. This is because the side wall 60a of the thick film circuit pattern 60 is roughened so that air can easily escape through the fine gaps formed by the irregularities of the rough surface. Also, air that could not be removed does not form bubbles because it is finely dispersed in the fine gaps.

  Conventionally, the thick film circuit pattern is formed so that the line edge, that is, the side wall of the thick film circuit pattern is smooth. This is because the smoother one can form a plurality of thick film circuit patterns closer to each other and achieve higher definition. In fact, in this field, there is a technical competition on how to smooth line edges. On the other hand, in the present invention, the effect of the preceding paragraph is obtained by intentionally forming the line edge into a rough and jagged shape rather than usual, based on the idea of reversal.

  The zigzag shape is preferably formed so that the distance from the convex peak to the adjacent convex peak is in the range of 10 to 600 μm (see FIG. 2). When it is less than 10 μm, it becomes difficult to form unevenness, and when it exceeds 600 μm, it is impossible to obtain sufficient bonding suitability. More preferably, it is 20-300 micrometers. More preferably, it is 40-150 micrometers.

  Further, it is preferable that the zigzag shape is formed so that the distance from the convex peak to the adjacent convex peak is in the range of 10 to 600 μm, and the difference between the convex peak and the concave peak is in the range of 2 to 50 μm ( (See FIG. 2). When the difference between the peak of the convex part and the peak of the concave part is less than 2 μm, the bonding ability cannot be obtained sufficiently, and when the difference between the peak of the convex part and the peak of the concave part exceeds 50 μm, the thick film runs side by side. reducing the gap between the circuit patterns (narrow frame) is difficult. More preferably, the difference between the peak of the convex portion and the peak of the concave portion is 3 to 25 μm. More preferably the difference in peaks of the recess of the projecting portion is 5 to 15 [mu] m.

  Further, the zigzag shape is more complex in the anchor structure than the pressure-sensitive adhesive layer 64. In other words, the unevenness and the protruding direction are different, so it can respond to various changes in how the force is applied, such as how to bend when using the touch panel and how to warp the touch panel in a high-temperature and high-humidity environment. it can. On the other hand, if the jagged shape is uniform, the anchor effect varies depending on how the force is applied.

  Further, the shape of the above-mentioned line edge formed in a jagged shape may be a more complicated and fractal shape, that is, a structure that is more jagged when the surface of the jagged surface is enlarged. This further increases the anchor effect.

  The thick film circuit pattern 60 has a region in which two or more of the thick film circuit patterns 60 run in parallel (see FIGS. 1 to 3), and an interval 5 between the thick film circuit patterns 60 that run in parallel is 10 to 60 μm. When the interval 5 is less than 10 μm, the pressure-sensitive adhesive layer 64 is difficult to enter between the thick film circuit patterns 60, and when the interval 5 exceeds 60 μm, it is difficult to narrow the frame. In addition, in this specification, the space | interval 5 means between the convex parts which protrude most.

  Further, as shown in FIG. 4, a circuit pattern 64 made of a transparent conductive film extended from the transparent electrode pattern 61 is provided between the film substrate 62 and the thick film circuit pattern 60. Good.

  The transparent conductive film 1 may include a pressure-sensitive adhesive (PSA) layer 64 for pasting so as to cover at least the formation region of the thick film circuit pattern 60 ( (See FIG. 5). As a method for applying the PSA layer 64, a normal printing method such as screen printing, offset printing, gravure printing, or flexographic printing may be used.

  The touch panel 1 can be obtained using the transparent conductive film 1 as described above. The touch panel is a sensor that detects where the user touches without disturbing the screen display of an LCD or the like. Although the touched position is detected electrically and the one not using electricity, the transparent conductive film 1 described above is used for an electric detection method such as a resistance film method or a capacitance method. is there. For example, in the case of the resistive film type touch panel 100, the two transparent conductive films 1 are bonded only at the peripheral edge so that the transparent electrodes face each other through the air layer. When the input surface is touched, the film bends due to the pressure, and the transparent electrodes come into contact with each other so that electricity flows. Therefore, the pressed position can be detected by measuring the voltage division ratio due to the resistance of each transparent electrode (Fig. 6). On the other hand, in the case of the capacitive touch panel 101, the position is detected by detecting the change in the capacitance between the fingertip and the transparent electrode. The transparent conductive film 1 is placed on the entire back surface of the glass plate. The two transparent conductive films 1 are bonded together so that the transparent electrodes face each other (see FIG. 7).

  A transparent conductive film made of indium tin oxide was formed by sputtering on one side of a 100 μm thick biaxially stretched polyethylene terephthalate film as a film substrate, and unnecessary portions were removed to form a transparent electrode pattern.

  Next, on the transparent electrode pattern, a silver paste (3 parts by weight of silver powder having an average particle diameter of 20 μm with respect to 10 parts by weight of acrylic resin) is used by screen printing to form a frame-shaped solid pattern having a thickness of 7 μm, which is unnecessary. The portion was removed, and a jagged thick film circuit pattern with uneven line edges on both sides was formed so as to be connected to the transparent electrode pattern to obtain a transparent conductive film. The line edge portion of the formed thick film circuit pattern has an average distance of 100 μm from the jagged convex peak to the adjacent convex peak, and an average difference of 14 μm between the convex peak and the concave peak. The gap between the running thick film circuit patterns was about 50 μm (see FIGS. 9 and 10).

  Finally, the two transparent conductive films were adhered to the entire surface with a pressure-sensitive adhesive layer so that the transparent electrodes were opposed to each other to obtain a capacitive touch panel.

  In the touch panel thus obtained, the pressure-sensitive adhesive layer did not bite air between the thick film circuit pattern and the side wall, and no bubbles were generated. In addition, the bonding force was strong enough to prevent the transparent conductive film from peeling due to bending when using the touch panel and warping of the touch panel in a high temperature and high humidity environment.

  A thick film circuit pattern was formed in the same manner as in Example 1 except that a silver nanocolloid material having an average particle diameter of 1 μm was used instead of the silver paste silver powder. In this case, compared to Example 1, the distance from the jagged-shaped convex peak at the line edge portion of the thick film circuit pattern to the adjacent convex peak is 100 μm on average, and the difference between the convex peak and the concave peak is 5 μm on average (See FIGS. 11 and 12). There, a sufficient effect for still stuck was obtained.

  A thick film circuit pattern was formed in the same manner as in Example 1 except that a copper foil having a thickness of 10 μm was used instead of the silver paste. In this case, compared with Example 1, the distance from the jagged convex peak at the line edge portion of the thick film circuit pattern to the adjacent convex peak is 40 μm on average, and the difference between the convex peak and the concave peak is 6 μm on average (See FIGS. 13 and 14). There, a sufficient effect for still stuck was obtained.

  It is to be noted that, by appropriately combining any of the various embodiments, the effects possessed by them can be produced. Although the present invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as long as they do not depart from the scope of the present invention.

  The present invention can be used for applications such as PDAs, handheld terminals and other portable information terminals, copiers, facsimile and other office automation equipment, smartphones, mobile phones, portable game devices, electronic dictionaries, car navigation systems, small PCs, and various household appliances. It is useful industrially.

DESCRIPTION OF SYMBOLS 1 Transparent conductive film 5 Gap between thick film circuit patterns 60 Thick film circuit pattern 61 Transparent electrode pattern 62 Film substrate 63 Circuit pattern made of transparent conductive film 64 Pressure sensitive adhesive layer 100 Resistance film type touch panel 101 Capacitance Touch panel

Claims (10)

A film substrate;
A transparent electrode pattern made of a transparent conductive film formed on one side of the film substrate;
A thick film circuit pattern made of a material having a resistance lower than that of the transparent conductive film, which is routed to a peripheral portion on the film substrate on which the transparent electrode pattern is formed and connected to an end of the transparent electrode pattern; A transparent conductive film comprising:
A transparent conductive film excellent in laminating suitability, wherein the thick film circuit pattern has a film thickness of 0.05 to 100 μm, and at least one line edge is formed in a zigzag shape.   The transparent conductive film excellent in bonding suitability of Claim 1 whose distance from the said convex-shaped convex peak of a jagged shape is 10-600 micrometers.   The transparent conductive film excellent in bonding suitability according to claim 2, wherein a difference between the peak of the convex portion and the peak of the concave portion is 2 to 50 μm.   The transparent conductive film excellent in bonding suitability according to any one of claims 1 to 3, wherein the jagged shape is a complicated structure.   The transparent conductive film excellent in bonding suitability according to claim 4, wherein the jagged shape is more complicated and has a fractal shape.   The transparent conductive film excellent in bonding suitability according to any one of claims 1 to 5, wherein the thick film circuit pattern is formed of a conductive paste.   The thick film circuit pattern has a region where two or more parallel runs, and the interval between the thick film circuit patterns running side by side is 10 to 60 µm. The bonding suitability according to any one of claims 1 to 6 excellent transparent conductive film.   Furthermore, in the bonding suitability in any one of Claims 1-7 provided with the circuit pattern which consists of a transparent conductive film extended from the said transparent electrode pattern between the said film base material and the said thick film circuit pattern. Excellent transparent conductive film.   Furthermore, the transparent conductive film excellent in the laminating suitability in any one of Claims 1-8 provided with a pressure sensitive adhesive layer so that the formation area of the said thick film circuit pattern may be covered at least.   A touch panel using the transparent conductive film according to claim 1.

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