JP2017111567A - Touch panel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a touch panel device excellent in folding resistance and image quality.SOLUTION: A foldable touch panel device comprises: a first transparent base material 11; a transparent electrode layer arranged on the first transparent base material 11 and having a projection 21 projected at a side opposite to the first transparent base material 11; and a second transparent base material 13 arranged on the transparent electrode layer and having a hole 31 at a position corresponding to the projection 21. In the second transparent base material 13, a product of breaking tension (N) and breaking extension is 10 or more, an in-plane direction retardation at a wavelength of 589 nm is -5 to 5 nm, a thickness direction retardation at the wavelength of 589 nm is -5 to 5 nm, and frequency of holding resistance in a holding resistance test is 100,000 times or more.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a touch panel device.

  The touch panel device is arranged on the surface of the image display device and the like, by referring to the image displayed in the image display area of the image display device, by bringing a finger or a pen into contact with or approaching the location where the image is displayed. The position information input device can input information corresponding to an image. Such touch panel devices are widely used in electronic devices such as mobile phones, car navigation devices, ticket machines, bank terminal machines (ATM devices), and game machines.

  On the other hand, development of thin and foldable electronic devices equipped with a touch panel device, such as a mobile phone equipped with a touch panel device, that is, a smartphone, has attracted attention. For example, with respect to smartphones, not only the “Curved Type” whose image display area is a curved surface, but also the development of “Bendted Type” and “Foldable Type” that can be bent are attracting attention. In particular, the development of “Foldable Type” that can be folded completely and can be folded and stored has attracted attention.

  In order to realize such a bendable touch panel device, first, it is conceivable to use a bendable image display device as the image display device. Specifically, it is conceivable to use a flexible organic EL display (OLED image display device) instead of a liquid crystal display device (LCD) as the image display device.

  Furthermore, in order to realize a bendable touch panel device, various configurations and members are being studied. For example, changing the glass substrate used as a member constituting the touch panel device to a bendable base material such as a resin film has been studied.

  Various types of touch panel devices have been studied. For example, the one described in Patent Document 1 can be cited.

JP2013-178687A

  A bendable touch panel device is required to use a member having high bending resistance, that is, high folding resistance as a member constituting the touch panel device. In addition, a bendable touch panel device is also required to have a structure with high folding resistance. For example, even when the touch panel device has a structure with high folding resistance, such as having a bridge electrode as described later, the members constituting the touch panel device have a shape suitable for the structure. It is also required to be able to.

  Further, in order to reduce the influence on the image quality such as the color of the image displayed on the image display device, the member constituting the touch panel device is also required to have a low phase difference (retardation).

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a touch panel device that is excellent in folding resistance and excellent in image quality.

  Examples of the touch panel device include those in which a transparent electrode provided on a transparent substrate is covered with a transparent cover layer. According to the inventor's study, in order to make such a touch panel device bendable and to improve its folding resistance, a cover layer such as a bridge electrode as described in Patent Document 1 is used as a transparent electrode. It has been found that it is effective to use a transparent electrode having a convex portion protruding to the side. Furthermore, the present inventor considered that it is effective to use a cover layer having a hole at a position corresponding to the convex portion. The cover layer is a bendable substrate such as a resin film. The base material used as the cover layer is required to have a certain degree of flexibility in order to be bendable. On the other hand, if the strength of the base material is not high to some extent, it may not be possible to form a suitable hole even when trying to puncture a needle or the like at a position corresponding to the convex portion. Was found by the present inventors.

  The inventor has made various studies on the cover layer, which is a transparent base material covering the transparent electrode, in the touch panel device having such a configuration, and arrived at the present invention as described below.

  A touch panel device according to an aspect of the present invention is a touch panel device that can be bent, and is disposed on a first transparent base material and the first transparent base material, and protrudes on a side opposite to the first transparent base material. A transparent electrode layer having a convex portion and a second transparent substrate disposed on the transparent electrode layer and having a hole at a position corresponding to the convex portion, wherein the second transparent substrate has a breaking tension ( N) and the product of the positive square root of the breaking elongation is 10 or more, the in-plane retardation at a wavelength of 589 nm is −5 to 5 nm, and the thickness direction retardation at a wavelength of 589 nm is −5 to 5 nm. It is characterized in that the folding endurance in the folding endurance test is 100,000 times or more.

  According to such a configuration, it is possible to provide a touch panel device having excellent folding resistance and excellent image quality.

  This is considered to be due to the following.

  First, as described above, the transparent electrode layer is covered with the second transparent substrate having a hole at a position corresponding to the position of the convex portion protruding to the second transparent substrate side of the transparent electrode layer. That is, it is considered that a touch panel device having a structure with high folding resistance can be obtained. And as this 2nd transparent base material, the base material whose product of breaking tension (N) and the positive square root of breaking elongation is 10 or more is used. Such a 2nd transparent base material has the flexibility which enables a bending, and can pierce a needle etc. in the position equivalent to the above-mentioned convex part, and can form a suitable hole. It is considered that the strength is as high as possible. Therefore, it is considered that the obtained touch panel device can suitably realize a structure that can be bent and has high folding resistance.

  In addition, since the in-plane direction retardation and the thickness direction retardation are small as described above, the second transparent base material has little influence on the image quality such as the color of the image displayed on the image display device. it is conceivable that. From this, it is considered that the deterioration of the image quality can be sufficiently suppressed. Therefore, it is considered that a touch panel device that can sufficiently suppress deterioration in image quality and has excellent image quality can be obtained.

  From the above, it is considered that a touch panel device having excellent folding resistance and excellent image quality can be obtained.

  In the touch panel device, the transparent electrode layer is adjacent to the plurality of first electrodes arranged in the first direction and the plurality of second electrodes arranged in the second direction intersecting the first direction in the first direction. A first connection part that connects the matching first electrodes and the hole are inserted, and the first connection part is arranged so as to intersect the first connection part via the second transparent base material located on the first connection part. Thus, it is preferable that the second connection portion that connects the second electrodes adjacent in the second direction is provided, and the second connection portion is the convex portion.

  According to such a configuration, a touch panel device having a structure with higher folding resistance can be obtained.

  In the touch panel device, it is preferable that the second transparent base material has a thickness of 6 to 25 μm.

  According to such a configuration, a touch panel device with higher folding resistance can be obtained.

  This means that the second transparent base material has a flexibility that allows bending, and a more suitable hole is formed when a hole is made by piercing a needle or the like at a position corresponding to the convex portion. This is considered to be due to having such strength.

  Moreover, in the touch panel device, the second transparent substrate contains a cellulose ester resin and an additive, and the additive includes (A) an alkylene dicarboxylic acid having 4 to 12 carbon atoms and 6 to 12 carbon atoms. A dicarboxylic acid unit derived from at least one selected from the group consisting of aryl dicarboxylic acids, an alkylene glycol having 2 to 12 carbon atoms, an aryl glycol having 6 to 12 carbon atoms, and an oxyalkylene glycol having 4 to 12 carbon atoms. An ester compound having a diol unit derived from at least one selected from the group consisting of: (B) an ester compound having an acyl group at the molecular end; and (C) at least one selected from the group consisting of a furanose ring and a pyranose ring. 1 to 12 sugar ester compounds in the molecule, and (D) a barbituric acid skeleton in the molecule Is preferably at least one selected from the group consisting of compounds.

  According to such a configuration, a touch panel device with higher folding resistance can be obtained.

  This is considered to be due to the following. When the second transparent substrate has flexibility that allows bending, and a hole is made by piercing a needle or the like at a position corresponding to the convex portion, a more suitable hole can be formed. It is thought that it has a sufficient strength.

  According to the present invention, it is possible to provide a touch panel device having excellent folding resistance and excellent image quality.

FIG. 1 is a schematic diagram illustrating a configuration of a touch panel device according to an embodiment of the present invention. FIG. 2 is a schematic view showing the structure of the transparent electrode layer in the touch panel device according to the embodiment of the present invention. FIG. 3 is a cross-sectional view of the touch panel device according to the embodiment of the present invention.

  Hereinafter, although the embodiment concerning the present invention is described, the present invention is not limited to these.

  The touch panel device according to the present embodiment is a bendable touch panel device. As shown in FIG. 1, the touch panel device 10 is disposed on the first transparent base material 11, the transparent electrode layer 12 disposed on the first transparent base material 11, and the transparent electrode layer 12. And a second transparent substrate 13. The touch panel device may include a surface member 14 on the second transparent base material 13. FIG. 1 is a schematic diagram illustrating a configuration of a touch panel device 10 according to the present embodiment.

  2 and 3, the transparent electrode layer 12 is disposed on the first transparent substrate 11, and is opposite to the first transparent substrate 11 (the second transparent substrate 13). A convex portion 21 protruding to the side). The second transparent substrate 13 is disposed on the transparent electrode layer 12 and has a hole 31 at a position corresponding to the convex portion 21. That is, as described above, the touch panel device 10 includes the second transparent base material 13 having the hole 31 at a position corresponding to the position of the convex portion 21 protruding to the second transparent base material 13 side of the transparent electrode layer 12. Then, the transparent electrode layer 12 is covered. Such a touch panel structure is considered to be a structure with high bending resistance, that is, high folding resistance. FIG. 2 is a schematic view showing the structure of the transparent electrode layer 12 in the touch panel device 10 according to the present embodiment. In FIG. 2, the second transparent base material 13 and the surface member 14 are not shown. FIG. 3 is a cross-sectional view of the touch panel device 10 according to the present embodiment. FIG. 3 is a cross-sectional view as viewed from the section line III-III in FIG.

  Moreover, as the said convex part 21, the connection part called what is called a bridge electrode is mentioned, for example. Specifically, the connection portion is as follows. As shown in FIG. 2, the transparent electrode layer 12 includes a plurality of first electrodes 22 arranged in a first direction and a plurality of second electrodes 23 arranged in a second direction intersecting the first direction. Can be mentioned. The transparent electrode layer 12 having such an electrode connects the first connection part 24 that connects the first electrodes 22 adjacent in the first direction and the second electrode 23 that connects the second electrodes 23 adjacent in the second direction. 2 connection parts 25. As shown in FIG. 3, the second connection part 25 passes through the hole 31 and intersects the first connection part 24 via the second transparent base material 13 a located on the first connection part 24. Arrange to do. By doing so, the second connection part 25 connects the second electrodes 23 adjacent in the second direction. And this 2nd connection part 25 protrudes on the opposite side to the said 1st transparent base material 11, and is equivalent to the convex part 21. As shown in FIG. Such a touch panel structure is considered to be a structure with higher bending resistance, that is, higher folding resistance.

  The transparent electrode layer 12 includes a wiring 27 connected to the first electrode 22 and the second electrode 23. A change based on a change in capacitance between the first electrode 22 and the second electrode 23 when the touch panel device is pressed with a finger or the like is output through the wiring 27. Based on the output result, the touch panel device inputs position information.

  The surface member 14 is provided to protect the surface of the touch panel device 10. The surface member 14 is not particularly limited as long as it can be bent. Examples of the first transparent substrate 11 include a translucent resin film, and specific examples include a polycarbonate (PC) film and a methyl methacrylate resin (PMMA) film.

  The first transparent substrate 11 is not particularly limited as long as it can be bent. Examples of the first transparent substrate 11 include translucent resin films, and specific examples include polyethylene terephthalate (PET) films, cycloolefin polymer (COP) films, and polycarbonate (PC) films. It is done. Further, as the first transparent substrate 11, the same one as the second transparent substrate 13 described later can be used. That is, as the first transparent substrate 11, the same material as the second transparent substrate can be used except that no hole is formed.

The transparent electrode layer 12 is not particularly limited as long as it can be bent, has the above-described structure, and can be used as an electrode layer of a touch panel device. Examples of the transparent electrode layer 12 include transparent conductive materials such as ITO (Indium Tin Oxide), SnO ₂ , and ZnO, silver nanowires, and copper wires. As the first electrode 22, the second electrode 23, the first connection portion 24, and the second connection portion 25, the above materials may be appropriately selected. Moreover, as said transparent electrode layer 12, a silver nanowire and a copper wire are preferable from a flexible viewpoint.

  The second transparent substrate 13 has a product of the breaking tension (N) and the positive square root of breaking elongation of 10 or more. The second transparent substrate 13 has an in-plane retardation at a wavelength of 589 nm of −5 to 5 nm, and a thickness direction retardation at a wavelength of 589 nm of −5 to 5 nm. And the said 2nd transparent base material 13 is bendable, and the folding-resistant frequency | count by a folding-resistant test is 100,000 times or more. The 2nd transparent base material 13 will not be specifically limited if said each structure is satisfy | filled. Further, when the second transparent substrate 13 satisfying the above-described conditions is used, a touch panel device that can be bent, has excellent folding resistance, and has excellent image quality can be obtained. If this is the 2nd transparent substrate of the above composition, it will have a flexibility which enables bending, and if it punctures a needle etc. in the position equivalent to the above-mentioned convex part, This is considered to be due to having such a strength that a suitable hole can be formed. Therefore, it is considered that the obtained touch panel device can suitably realize a structure that can be bent and has high folding resistance. Further, it is considered that the second transparent base material has little influence on the image quality such as the color of the image displayed on the image display device.

  The second transparent substrate 13 has a product of breaking tension (N) and a positive square root of breaking elongation [breaking tension (N) × √breaking elongation] (toughness) of 10 or more as described above. It is preferable that it is 10-140, and it is more preferable that it is 10-60. This product is an index indicating the strength of the second transparent substrate. If this product is small, the strength is low, and if this product is large, the strength is high. If the product is too small, it is difficult to form a suitable hole when a needle is pierced and a hole is made mechanically. Moreover, when the said product is too large, there exists a tendency for a softness | flexibility to fall. Therefore, it tends to be difficult to bend. For these reasons, if the product is within the above range, the second transparent base material has flexibility that enables bending, and a needle or the like is pierced at a position corresponding to the convex portion, If it is opened, it is considered that it has a strength capable of forming a suitable hole. Therefore, in the touch panel device, a structure with excellent folding resistance can be suitably realized.

  The breaking tension is the maximum force that can be withstood when the measurement object (here, the second transparent substrate) is pulled. Moreover, breaking elongation is elongation until the breaking tension of a measuring object is measured. That is, the elongation at break is the ratio of the difference between the length before the start of measurement and the length before the start of measurement relative to the length of the measurement object before the start of measurement [(length-measurement when the break tension is measured Length before start) / length before start of measurement]. The breaking tension and breaking elongation can be measured with a tensile tester or the like. Further, as the elongation at break, the ratio of the difference between the length before the start of measurement and the length before the start of measurement relative to the length of the measurement object before the start of measurement [(length-measurement when the break tension is measured) When using the value of (length before start) / length before start of measurement × 100] (%), a value obtained by dividing this value by 100 is used when calculating toughness. For example, when the breaking elongation is 30%, the toughness is calculated assuming that the breaking elongation is 0.3.

  Moreover, as for the said 2nd transparent base material 13, the in-plane direction retardation in wavelength 589nm is -5-5 nm as mentioned above, and it is preferable that it is -3-3 nm. The second transparent substrate 13 has a thickness direction retardation at a wavelength of 589 nm of −5 to 5 nm, and preferably −3 to 3 nm.

  If the in-plane retardation is too large, or the thickness direction retardation is too small or too large, the influence on image quality such as the color of an image displayed on the image display device tends to increase. Therefore, the image quality of the image displayed by the image display device tends to be lowered by the touch panel device. From this, if the 2nd transparent base material whose said in-plane direction retardation and said thickness direction retardation are respectively in the said range is used, the fall of image quality can fully be suppressed and the touch panel apparatus excellent in image quality is obtained. This is because, as the second transparent base material, the in-plane direction retardation and the thickness direction retardation are small as described above, the influence on the image quality such as the color of the image displayed on the image display device. This is probably due to the fact that there are few. From this, it is considered that the deterioration of the image quality can be sufficiently suppressed.

  Moreover, in-plane direction retardation Re (589) is calculated | required from following formula (II).

Re (589) = (nx−ny) × d (II)
Moreover, thickness direction retardation Rth (589) is calculated | required from following formula (III).

Rth (589) = {(nx + ny) / 2−nz} × d (III)
In the above formulas (II) and (III), nx represents the refractive index in the slow axis direction of the film, ny represents the refractive index in the fast axis direction, and nz represents the refractive index in the thickness direction. D represents the film thickness (nm) of the film.

  Re (589) and Rth (589) can be measured using an automatic birefringence meter. For example, using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments), it can be obtained at a wavelength of 589 nm in an environment of a temperature of 23 ° C. and a humidity of 55% RH.

  The second transparent substrate 13 can be bent. And as durability at the time of repeating bending of the 2nd transparent substrate 13, the 2nd transparent substrate 13 has the durability that the number of times of folding in a folding test is 100,000 times or more, for example. . Further, the greater the number of folding times, the better, but in practice, the limit is about 300,000 times. Therefore, the upper limit of the folding endurance in the folding endurance test is 300,000 times. That is, the second transparent substrate 13 has a folding endurance of 100,000 times or more in a folding endurance test, preferably 15 to 300,000 times, and more preferably 25 to 300,000 times. If the number of folding times is too small, the folding resistance of the touch panel device tends to be insufficient. Therefore, when the number of folding times is within the above range, a touch panel device having excellent folding resistance can be obtained.

  Note that the folding endurance is the number of flexing when the second transparent base material, which is an object to be measured, undergoes ductile fracture that is greatly deformed and fractured when performing a folding endurance test in which bending is repeated. Further, the folding test is performed using, for example, an MIT type folding tester (MIT TYPE FOLDING ENDURANCE TESTER manufactured by Toyo Seiki Seisakusyo Co., Ltd.) under an environment of a temperature of 23 ° C. and a humidity of 55% RH. Examples include a test in which bending is repeated under the conditions of times / minute, bending angle left and right 135 °, load 0.5 kgf (4.9 N), and curvature radius 2 mm. That is, the number of times of folding in the folding test includes the number of times when such a folding test is repeated to cause ductile fracture.

  The second transparent substrate 13 is not particularly limited as long as it satisfies the above-described conditions. In order to satisfy the above conditions, the second transparent substrate 13 may be obtained by adjusting its composition, thickness, and the like.

  The thickness of the second transparent substrate 13 is preferably 6 to 25 μm, more preferably 10 to 21 μm, and further preferably 14 to 18 μm. If the second transparent substrate is too thin, the strength of the second transparent substrate tends not to achieve a strength that allows a suitable hole to be formed when a hole is mechanically pierced with a needle or the like. There is. Moreover, when the second transparent substrate is too thick, the flexibility tends to decrease. Therefore, it tends to be difficult to bend. For these reasons, when the thickness is within the above range, the second transparent base material has a flexibility that allows bending, and a needle or the like is pierced at a position corresponding to the convex portion to form a hole. If it opens, it will be considered that it becomes the 2nd transparent substrate which has the intensity which can form a suitable hole.

  Moreover, as said 2nd transparent base material 13, what contains a cellulose-ester resin and an additive is mentioned, for example. Examples of the second transparent substrate 13 include a cellulose ester film containing a cellulose ester resin as a main component, and the resin component may be a resin film made of a cellulose ester resin. Here, a main component means that content with respect to the whole film quantity is 50 mass% or more. And as for the said 2nd transparent base material 13 in this embodiment, what contained the additive mentioned later to a cellulose-ester film is mentioned.

  The cellulose ester resin is not particularly limited as long as it is a cellulose ester resin that can be used for a resin film. Examples of the cellulose ester resin include cellulose acetate resin, cellulose diacetate resin, cellulose triacetate resin, cellulose butyrate resin, cellulose propionate resin, cellulose acetate butyrate resin, and cellulose acetate propionate resin. Can be mentioned. Among the resins exemplified above, the cellulose acetate resin is preferably a cellulose triacetate resin. In addition, as the cellulose ester resin, the above exemplified resins may be used alone, or two or more kinds may be used in combination.

  The number average molecular weight of the cellulose ester resin is preferably 30,000 to 200,000 from the viewpoint of high mechanical strength when molded into a resin film and an appropriate dope viscosity in the solution casting film forming method. Further, the weight average molecular weight (Mw) / number average molecular weight (Mn) is preferably in the range of 1 to 5, and more preferably in the range of 1.4 to 3.

  The average molecular weight and molecular weight distribution of the resin such as the cellulose ester resin can be measured using gel permeation chromatography or high performance liquid chromatography. Therefore, the number average molecular weight (Mn) and the weight average molecular weight (Mw) can be calculated using these, and the ratio can be calculated.

  The cellulose ester resin preferably has an acyl group as a substituent, specifically, an acyl group having 2 to 4 carbon atoms, such as an acetyl group. The degree of substitution of this acyl group (acyl substitution degree) is preferably 2.9 or more, for example. That is, it is preferable that the substitution degree of an acyl group is 2.9-3. As the cellulose ester resin, specifically, triacetyl cellulose having an acetyl group substitution degree (acetyl substitution degree) of 2.9 or more (2.9 to 3) is low in retardation. It is preferable at the point from which a resin film is obtained.

  The portion not substituted with an acyl group usually exists as a hydroxyl group. These cellulose ester resins can be synthesized by a known method. The measuring method of the substitution degree of an acyl group can be measured according to the provisions of ASTM-D817-96.

  The resin other than the cellulose ester resin is not particularly limited as long as it is a resin that can be contained together with the cellulose ester resin to form a resin film. Examples of resins other than the cellulose ester resin include polyester resins such as polyethylene terephthalate resin and polyethylene naphthalate resin, acrylic resins such as polymethyl methacrylate resin, polysulfone (including polyethersulfone) resin, polyethylene resin, and polypropylene resin. , Cellophane, polyvinylidene chloride resin, polyvinyl alcohol resin, ethylene vinyl alcohol resin, syndiotactic polystyrene resin, cycloolefin resin, polymethylpentene resin and other vinyl resins, polycarbonate resin, polyarylate resin, polyether ketone resin, poly Examples thereof include ether ketone imide resins, polyamide resins, and fluororesins.

  Examples of the additive include components (A) to (D) described later. As said additive, (A)-(D) component may be used independently, and may be used in combination of 2 or more type.

  The component (A) includes a dicarboxylic acid unit derived from at least one selected from the group consisting of alkylene dicarboxylic acids having 4 to 12 carbon atoms and aryl dicarboxylic acids having 6 to 12 carbon atoms, and alkylene having 2 to 12 carbon atoms. An ester compound having a diol unit derived from at least one selected from the group consisting of glycol, aryl glycol having 6 to 12 carbon atoms, and oxyalkylene glycol having 4 to 12 carbon atoms. This ester compound is an ester compound containing a repeating unit obtained by reacting a dicarboxylic acid and a diol, specifically, the dicarboxylic acid unit (carboxylic acid residue) and the diol unit (alcohol residue). . Moreover, this ester compound may be sealed at one end or both ends, or may not be sealed. Moreover, as this (A) component, the compound represented by following formula (I) is mentioned, for example.

B- (GA) _n -GB (I)
In formula (I), B represents a hydroxyl group, an acetic acid group, an aliphatic monocarboxylic acid residue, or an aromatic monocarboxylic acid residue. G represents an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms. A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms. n represents 1 or more. A is the dicarboxylic acid unit (carboxylic acid residue). G is the diol unit (alcohol residue). B is a terminal group. n is the degree of polymerization.

  The dicarboxylic acid unit (carboxylic acid residue) and the diol unit (alcohol residue) may be any of the above units (residues), and may include the above unit alone, or two or more types. The unit may be included.

  Examples of the dicarboxylic acid unit A include alkylene dicarboxylic acid residues having 4 to 12 carbon atoms, aryl dicarboxylic acid residues having 6 to 12 carbon atoms, and the like. Examples of the diol unit G include alkylene glycol residues having 2 to 12 carbon atoms, aryl glycol residues having 6 to 12 carbon atoms, and oxyalkylene glycol residues having 4 to 12 carbon atoms. Examples of the terminal group B include a hydroxyl group, an acetic acid group, an aliphatic monocarboxylic acid residue, and an aromatic monocarboxylic acid residue.

  The weight average molecular weight of the ester compound is preferably in the range of 500 to 3000, and more preferably in the range of 600 to 2000. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

  The degree of polymerization n may be 1 or more, and is preferably n such that the weight average molecular weight falls within the above range.

  The component (B) is an ester compound having an acyl group at the molecular end. Examples of the ester compound include polyesters in which a hydrogen atom at a hydroxyl terminal is substituted with an acyl group derived from a monocarboxylic acid. Moreover, it is preferable that this ester compound contains an alicyclic skeleton.

  The ester compound may be an ester compound having an acyl group at the molecular end, and an ester compound having a repeating unit obtained by reacting an acyclic aliphatic diol with a dicarboxylic acid containing an alicyclic structure (non- Derivatives in which the molecular terminal of a cyclic aliphatic diol residue and a dicarboxylic acid residue containing an alicyclic structure) is substituted with an acyl group, and an aliphatic diol containing an alicyclic structure and an acyclic aliphatic dicarboxylic acid The molecular end of an ester compound (an ester compound containing an aliphatic diol residue containing an alicyclic structure and an acyclic aliphatic dicarboxylic acid residue) having a repeating unit obtained by reacting with an acid was substituted with an acyl group Derivatives and the like. Among these, a derivative in which the molecular terminal of an ester compound having a repeating unit obtained by reacting an acyclic aliphatic diol with a dicarboxylic acid containing an alicyclic structure is substituted with an acyl group is more preferable. The acyclic aliphatic diol residue is preferably a divalent group derived from an acyclic aliphatic diol having 2 to 10 carbon atoms, and an acyclic aliphatic diol having 2 to 8 carbon atoms. The divalent group derived from is more preferably a divalent group derived from an acyclic aliphatic diol having 2 to 6 carbon atoms. The dicarboxylic acid residue containing the alicyclic structure is preferably a divalent group derived from a C3-12 dicarboxylic acid containing a 3-6 membered alicyclic structure. The number of carbon atoms here is preferably 3 to 10, more preferably 3 to 8, and still more preferably 3 to 6. Further, the alicyclic structure here may be either a monocyclic ring or a polycyclic ring as long as it is a 3- to 6-membered ring, but a monocyclic ring is preferable. And an alicyclic structure is a 3-6 membered ring, and a 5-6 membered ring is preferable. Specific examples of the alicyclic structure include cyclopropylene group, 1,2-cyclobutylene group, 1,3-cyclobutylene group, 1,2-cyclopentylene group, 1,3-cyclopentylene group, 1 , 2-cyclohexylene group, 1,3-cyclohexylene group, 1,4-cyclohexylene group and the like.

  Preferable specific examples of the component (B) include, for example, ester compounds having a repeating unit obtained by reacting cyclohexanedicarboxylic acid and ethylene glycol (a copolymer of cyclohexanedicarboxylic acid and ethylene glycol). However, the present invention is not limited to this.

  The component (C) is a sugar ester compound having 1 to 12 in the molecule of at least one selected from the group consisting of a furanose ring and a pyranose ring. The sugar ester compound is an ester compound (sugar ester compound) excluding cellulose ester, in which all or part of the hydroxy group of a compound (saccharide) having 1 to 12 at least one of a pyranose structure and a furanose structure is esterified. ). Further, the saccharide may be a monosaccharide or a polysaccharide having 2 to 12 sugar structures linked together.

  The monocarboxylic acid used for esterifying the hydroxy group of the saccharide is not particularly limited. Examples of the monocarboxylic acid include known aliphatic monocarboxylic acids, alicyclic monocarboxylic acids, and aromatic monocarboxylic acids. Moreover, as this monocarboxylic acid, 1 type may be used independently and 2 or more types may be used in combination.

  Preferable specific examples of the component (C) include, for example, acetyl saccharose, but are not limited thereto.

  The component (D) is a compound having a barbituric acid skeleton in the molecule. Moreover, as this (D) component, the compound represented by following formula (1) is mentioned, for example.

In formula (1), R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, or a carbon number. A 5-20 heteroaryl group or a C6-C20 aryl group is shown. R ₃ represents a substituent containing an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, or an aromatic ring having 6 to 20 carbon atoms.

  The alkyl group and the alkenyl group preferably have 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. The alkynyl group preferably has 2 to 15 carbon atoms, more preferably 2 to 10 carbon atoms, and particularly preferably 2 to 5 carbon atoms. The alkyl group, the alkenyl group, and the alkynyl group may be cyclic, linear, or branched, but are preferably linear or branched, and are linear. Is more preferable. The heteroaryl group preferably has 5 to 18 carbon atoms, and more preferably 5 to 12 carbon atoms. The aryl group preferably has 6 to 18 carbon atoms, and more preferably 6 to 12 carbon atoms.

  Preferable specific examples of the component (D) include, but are not limited to, compounds represented by the following formula (2).

  Moreover, it is preferable that it is 3-18 mass% with respect to the said cellulose-ester resin, and, as for content of the said additive, it is more preferable that it is 6-16 mass%, and it is 10-12 mass%. Further preferred. When the content of the additive is too small, the effect of adding the additive is reduced, the moisture permeability of the film is increased, and the deterioration of the electrode tends to proceed. On the other hand, if the content of the additive is too large, the transparency of the film is lowered due to poor compatibility, and the additive tends to bleed out in a high temperature and high humidity environment. From these things, when the content is within the above range, the second transparent base material has a flexibility that enables bending, and punctures a needle or the like to form a more suitable hole mechanically. It is thought that it becomes the 2nd transparent substrate which has the intensity which can be used.

  Moreover, you may contain other components other than the said cellulose-ester resin and the said additive in the said 2nd transparent base material 13 in the range which does not inhibit the effect of this invention. Examples of components other than the additives include plasticizers, antioxidants, ultraviolet absorbers, heat stabilizers, conductive substances, flame retardants, lubricants, and matting agents.

  Moreover, the manufacturing method of the said 2nd transparent base material 13 will not be specifically limited if the said resin film can be manufactured. As a manufacturing method of the said resin film, the manufacturing method by the solution casting film forming method etc. are mentioned, for example. As a method for producing this resin film, specifically, a resin solution containing the cellulose ester resin and the fine particles is cast from a casting die on a traveling support to form a casting film. Examples of the method include a stretching step and a peeling step of peeling the cast film from the support to obtain a film. In addition to the above steps, the method for producing a resin film by the solution casting film forming method may include other steps.

  Further, as described above, the second transparent substrate 13 has a hole 31 at a position corresponding to the convex portion 21 of the transparent electrode layer 12. A method for forming the hole 31 is not particularly limited as long as a hole having an appropriate shape can be formed at an appropriate position. Examples of the hole forming method include a method of mechanically forming a hole by piercing the second transparent substrate with a needle or the like. The touch panel device can be manufactured by assembling the second transparent base material in which the holes are formed in this manner so as to have the configuration of the touch panel device described above. The touch panel device thus obtained can be bent and can suitably input position information.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example 1]
(Second transparent substrate)
With respect to 100 parts by mass of cellulose triacetate resin (TAC) (acetyl group substitution degree 2.9), which is a cellulose ester resin, the second transparent substrate has 10 parts by mass of component (A) as an additive, C) A resin film containing 10 parts by mass of the component. The component (A) is a compound represented by the following formula (I), wherein A is a group represented by the following formula (3), G is a group represented by the following formula (4), and B is This is a compound represented by the following formula (5), wherein n is 3. Component (C) is a sugar ester compound [a sugar ester compound in which 6 out of all 8 OH groups of sucrose (sucrose, sucrose) are substituted with acetyl groups].

B- (GA) _n -GB (I)

  Specifically, with respect to 100 parts by mass of cellulose triacetate resin (acetyl group substitution degree 2.9) which is a cellulose ester resin, 10 parts by mass of component (A) and 10 parts by mass of component (C) are used as additives. The resin film having a thickness of 15 μm was obtained by a solution casting film forming method using a solution containing a solvent and further added with a solvent as a dope, without stretching. This resin film was used as the second transparent substrate.

  Moreover, this 2nd transparent base material was cut | disconnected to width 55mm and length 110mm. The breaking tension and breaking elongation of the cut second transparent base material were measured using a tensile tester (RTC-1225A manufactured by Orientec Co., Ltd.). From the obtained breaking tension and breaking elongation, the product (toughness) of breaking tension (N) and the positive square root of breaking elongation (%) was calculated. The measured breaking tension was 25 N, and the breaking elongation was 0.3 (30%). The toughness calculated from the breaking tension and breaking elongation was about 14.

  In addition, Re (589) and Rth (589) of the obtained second transparent substrate were measured using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments) with a temperature of 23 ° C. and a humidity of 55% RH. The measurement was performed using light with a wavelength of 589 nm. As a result, Re (589) was 1 nm and Rth (589) was 1 nm.

  Further, the obtained second transparent substrate was subjected to a folding test. Specifically, first, the second transparent substrate was cut into a width of 15 mm and a length of 110 mm. Bending speed of the cut second transparent base material was measured using an MIT type folding tester (MIT TYPE HOLDING ENDURANCE TESTER manufactured by Toyo Seiki Seisakusyo Co., Ltd.) in an environment of a temperature of 23 ° C. and a humidity of 55% RH. The test was repeatedly bent under the conditions of 175 times / min, bending angle left and right 135 °, load 0.5 kgf (4.9 N), and radius of curvature 2 mm. And the frequency | count when the 2nd transparent base material raise | generated ductile fracture was measured. This number of times was defined as the number of folding times. As a result, it was 150,000 times.

(First transparent substrate and transparent electrode layer)
As a 1st transparent base material, a transparent electrode layer provided with a bridge electrode as shown in FIG.2 and FIG.3 with a silver nanowire on a cycloolefin polymer (COP) film (Nippon Zeon Co., Ltd. product ZEONOR film). Formed.

(Touch panel device)
First, holes (diameter 5 mm) for forming bridge electrodes were mechanically formed at intervals of 1.5 mm by piercing the second transparent substrate with a needle for drilling. A touch panel device as shown in FIG. 1 provided in a flexible organic EL display (an OLED image display device) using the second transparent substrate and the first transparent substrate on which a transparent electrode layer is formed. Was prepared according to a conventional method.

[Examples 2 to 8 and Comparative Examples 1 and 2]
In Examples 2 to 8 and Comparative Example 1, as the second transparent base material, the additive used is changed to the additive shown in Table 1, and the thickness, toughness, Re (589) (in Table 1, simply “Re” And Rth (589) (simply indicated as “Rth” in Table 1), and the number of folding times is the same as that shown in Table 1, and the same as in Example 1. is there.

  In addition, the compound mentioned above was used as (A) component.

  As the component (B), a copolymer of cyclohexanedicarboxylic acid and ethylene glycol was used.

  Moreover, the compound mentioned above was used as (C) component.

  Further, as the component (D), a barbituric acid derivative (compound represented by the above formula (2)) was used.

[Examples 13 and 14 and Comparative Example 7]
Using polyimide (PI, Equois BMP manufactured by Mitsui Chemicals, Inc.), thickness, toughness, Re (589) (indicated simply as “Re” in Table 1), Rth (589) (in Table 1, simply It is the same as that of Example 1 except that the resin film manufactured so that the number of folding times is the value shown in Table 1 is used.

[Example 15]
Using a mixture (mass ratio 50:50) of cellulose ester resin (CE, CAB482 manufactured by Eastman Kodak Co., Ltd.) and polymethyl methacrylate (PMMA, 80N manufactured by Asahi Kasei Co., Ltd.), thickness, toughness, Re (589) ) (Simply indicated as “Re” in Table 1), Rth (589) (simply indicated as “Rth” in Table 1), and folding times so that the values shown in Table 1 are obtained. The same as Example 1 except that the manufactured resin film was used.

[Comparative Example 3]
Using polyethylene terephthalate (PET, Cosmo Shine manufactured by Toyobo Co., Ltd.), thickness, toughness, Re (589) (indicated simply as “Re” in Table 1), Rth (589) (in Table 1, simply It is the same as that of Example 1 except that the resin film manufactured so that the number of folding times is the value shown in Table 1 is used.

[Comparative Example 4]
Using polymethylmethacrylate (PMMA, manufactured by Mitsubishi Rayon Co., Ltd.), thickness, toughness, Re (589) (indicated simply as “Re” in Table 1), Rth (589) (in Table 1, This is the same as in Example 1 except that the resin film manufactured so that the number of folding times is the value shown in Table 1 is used.

[Comparative Examples 5 and 6]
Using a cycloolefin polymer (COP) (ZEONOR film manufactured by Nippon Zeon Co., Ltd.), thickness, toughness, Re (589) (indicated simply as “Re” in Table 1), Rth (589) (in Table 1) Is simply indicated as “Rth”), and is the same as in Example 1 except that the resin film manufactured so that the folding number of times becomes the value shown in Table 1 was used.

[Bending line]
The obtained touch panel device was bent under the same conditions as in the folding resistance test. Then, the number of times until the touch panel device was disconnected was measured.

  At that time, if the number of times is 150,000 times or more, it is evaluated as “◯”, if it is 100,000 times or more and less than 150,000 times, it is evaluated as “△”, and if it is less than 100,000 times, “×” ".

[Color change]
The color of the image of the touch panel device and the color of the image of only the organic EL display which is an image display device provided in the touch panel device were comparatively observed, and 10 general monitors evaluated the presence or absence of the influence on the color. As a result, if the number of persons judged to have no influence on the color of the displayed image is 9 or more, it is evaluated as “◯”, and if it is 5-8, it is evaluated as “Δ” and 4 or less. If so, it was evaluated as “×”.

[Machinability]
In the obtained touch panel device, if the ratio (defective rate) of the touch panel device in which the defect due to the hole of the second transparent base material occurs to the total touch panel device is 1% or less, it is evaluated as “◯” and 1% If it was higher than 5%, it was evaluated as “Δ”, and if it was higher than 5%, it was evaluated as “x”.

  These results are shown in Table 1. Moreover, the mass part of the additive 1 and the additive 2 in Table 1 is content (mass part) with respect to 100 mass parts of resin components, such as TAC.

  As can be seen from Table 1, in the touch panel device (Examples 1 to 15) using a resin film having a toughness of 10 or more and a folding resistance of 100,000 or more as the second transparent substrate, the folding resistance is As compared with the case of using a resin film having less than 100,000 times (Comparative Examples 2 and 6), it was difficult to cause bending breakage. Moreover, in the touchscreen device which concerns on Examples 1-15, it is excellent in workability compared with the case where the resin film whose toughness is less than 10 is used (Comparative Examples 1, 4, 5), and the second transparent substrate. Defects due to the holes were difficult to occur. In addition, the touch panel devices according to Examples 1 to 15 using a resin film in which both Re (589) and Rth (589) are small used a resin film in which Re (589) and Rth (589) exceed 5 nm. Compared with the case (Comparative Example 3), it was a touch panel device with little color change and excellent image quality. From the above, toughness is 10 or more, Re (589) is -5 to 5 nm, Rth (589) is -5 to 5 nm, and the folding resistance is 100,000 or more. When using a resin film as a 2nd transparent base material, it turned out that it is excellent in folding resistance and the touchscreen apparatus excellent in the image quality is obtained.

DESCRIPTION OF SYMBOLS 10 Touch panel apparatus 11 1st transparent base material 12 Transparent electrode layer 13 2nd transparent base material 14 Surface member 21 Convex part 22 1st electrode 23 2nd electrode 24 1st connection part 25 2nd connection part 27 Wiring 31 hole

Claims (4)

A bendable touch panel device,
A first transparent substrate, a transparent electrode layer disposed on the first transparent substrate, and having a convex portion protruding on the opposite side of the first transparent substrate; and disposed on the transparent electrode layer, A second transparent substrate having a hole at a position corresponding to the convex portion,
The second transparent substrate is
The product of the breaking tension (N) and the positive square root of breaking elongation is 10 or more,
The in-plane retardation at a wavelength of 589 nm is −5 to 5 nm,
The thickness direction retardation at a wavelength of 589 nm is −5 to 5 nm,
A touch panel device characterized in that the folding endurance in the folding endurance test is 100,000 times or more. The transparent electrode layer is
A plurality of first electrodes arranged in a first direction;
A plurality of second electrodes arranged in a second direction intersecting the first direction;
A first connection portion connecting the first electrodes adjacent in the first direction;
The second electrodes adjacent to each other in the second direction by being inserted through the holes and arranged so as to intersect the first connection part via the second transparent base material located on the first connection part. A second connecting portion for connecting
The touch panel device according to claim 1, wherein the second connection portion is the convex portion.   The touch panel device according to claim 1 or 2, wherein the second transparent substrate has a thickness of 6 to 25 µm. The second transparent substrate contains a cellulose ester resin and an additive,
The additive is (A) a dicarboxylic acid unit derived from at least one selected from the group consisting of an alkylene dicarboxylic acid having 4 to 12 carbon atoms and an aryl dicarboxylic acid having 6 to 12 carbon atoms, and 2 to 12 carbon atoms. An ester compound having an alkylene glycol, an aryl glycol having 6 to 12 carbon atoms, and a diol unit derived from at least one selected from the group consisting of oxyalkylene glycols having 4 to 12 carbon atoms, (B) an acyl group at the molecular terminal (C) a sugar ester compound having 1 to 12 at least one selected from the group consisting of a furanose ring and a pyranose ring, and (D) a compound having a barbituric acid skeleton in the molecule The touch panel according to claim 1, wherein the touch panel is at least one selected from the group consisting of: Location.

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