JP5791275B2 - Transparent conductive layer sheet and method for producing the same - Google Patents

Description

The present invention relates to a transparent conductive film layer sheet, particularly a transparent conductive film layer sheet having a function of blocking moisture from the outside and protecting the adhesive layer, and a method for producing the same, and is suitable for a capacitive touch sensor. .

Conventionally, there has been Patent Document 1 as a document of a capacitance-type transparent touch switch attached via an adhesive layer.

The invention of Patent Document 1 is a capacitance-type transparent touch switch including a plurality of the above-described transparent planar bodies, and each of the transparent planar bodies is attached via an adhesive layer, and the adhesive layer is an epoxy. A general transparent adhesive such as a system or acrylic is used, and the thickness is about 25 to 75 μm.

Special republication WO2006-126604

However, 25 to 25 using a common transparent adhesive such as epoxy or acrylic as the adhesive layer
When it is formed to a thickness of about 75 μm, there is a problem that when exposed to a high temperature and high humidity environment, moisture from outside air is absorbed and the surface is whitened.

In particular, when the thickness of the pressure-sensitive adhesive layer is large, the intrusion of moisture from the side surface becomes remarkable, the degree of whitening becomes worse, and sometimes even the transparent conductive film layer is affected by the moisture.

The present invention is a transparent conductive film layer sheet in which a transparent conductive film layer is formed, and an in-plane retardation value Re at a wavelength of 550 nm is 20 nm or less and an adhesive layer is formed on one side of a base sheet made of a material having high water vapor permeability. A transparent conductive film layer sheet in which a protective sheet made of a material having a water vapor barrier property is laminated on a surface opposite to the adhesive layer forming surface. In the present invention, the protective sheet may be formed in a three-dimensional shape so as to be covered up to the side surface of the pressure-sensitive adhesive layer opposite to the base sheet.

Moreover, the transparent conductive film layer sheet | seat characterized by the material of the said protection sheet | seat being a cycloolefin resin may be sufficient as this invention. The base sheet may be a transparent conductive film layer sheet, wherein the base sheet is a polycarbonate resin film.

The present invention also relates to a method for producing a transparent conductive film layer sheet, comprising forming an adhesive layer on one side of a substrate sheet on which a transparent conductive film layer is formed, and laminating a protective sheet on the surface opposite to the adhesive layer forming surface. And
The manufacturing method of the transparent conductive film layer sheet | seat characterized by laminating | stacking the protective sheet previously formed in three-dimensional shape so that the side surface of the said adhesion layer may be coat | covered may be sufficient. The present invention also relates to a method for producing a transparent conductive film layer sheet, comprising forming an adhesive layer on one side of a substrate sheet on which a transparent conductive film layer is formed, and laminating a protective sheet on the surface opposite to the adhesive layer forming surface. The protective sheet may be laminated while being processed into a three-dimensional shape so as to extend to the side surface of the adhesive layer. The present invention also relates to a method for producing a transparent conductive film layer sheet, comprising forming an adhesive layer on one side of a substrate sheet on which a transparent conductive film layer is formed, and laminating a protective sheet on the surface opposite to the adhesive layer forming surface. And after the said lamination | stacking, the manufacturing method of the transparent conductive film layer sheet | seat characterized by processing a protective sheet so that the side surface of an adhesion layer may be followed may be sufficient.

  Moreover, this invention is an electrostatic capacitance type touch sensor using the said transparent conductive film layer sheet.

In the transparent conductive film layer sheet of the present invention, a transparent conductive film layer is formed, and an adhesive layer is formed on one side of a base sheet made of a material having a in-plane retardation value Re of 20 nm or less at a wavelength of 550 nm and high water vapor permeability. A transparent conductive film layer sheet, wherein a protective sheet made of a material having a water vapor barrier property is laminated on a surface opposite to the adhesive layer forming surface.
Therefore, since the intrusion of moisture can be prevented by the protective sheet, there is an effect that whitening can be prevented even if the base sheet has high water vapor permeability.

Moreover, the transparent conductive film layer sheet of the present invention is characterized in that the protective sheet is formed in a three-dimensional shape so as to be covered up to the side surface of the adhesive layer opposite to the base sheet. Therefore,
Even when the adhesive layer is thick, moisture can be prevented from entering from the side surface, so that whitening can be further prevented.

Moreover, the method for producing a transparent conductive film layer sheet of the present invention comprises forming a pressure-sensitive adhesive layer on one side of a substrate sheet on which a transparent conductive film layer is formed, and laminating a protective sheet on the surface opposite to the pressure-sensitive adhesive layer forming surface. A method for producing a conductive film layer sheet, characterized in that a protective sheet previously formed in a three-dimensional shape is laminated so as to cover a side surface of the adhesive layer. Therefore, there is an effect that the transparent conductive film layer sheet in which whitening is prevented can be produced with high productivity and high quality.

Moreover, the method for producing a transparent conductive film layer sheet of the present invention comprises forming a pressure-sensitive adhesive layer on one side of a substrate sheet on which a transparent conductive film layer is formed, and laminating a protective sheet on the surface opposite to the pressure-sensitive adhesive layer forming surface. A method for producing a conductive layer sheet, characterized by laminating a protective sheet while processing into a three-dimensional shape so as to extend to the side surface of the adhesive layer, or after laminating the protective sheet, the protective sheet is adhered to the adhesive layer It is characterized by being processed along the side surface. Therefore, there is an effect that the transparent conductive film layer sheet in which whitening is prevented can be produced with high productivity and high quality.

In addition, the capacitive touch sensor of the present invention is characterized by using the transparent conductive film layer sheet. Therefore, there is an effect that a capacitance type touch sensor that prevents whitening can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic cross section which shows the transparent conductive film layer sheet | seat of this invention, (a) shows the example in which the transparent conductive film layer and the adhesion layer were formed one each, (b) shows a base sheet, a transparent conductive film layer, and (C) shows an example in which two adhesive layers are formed, and (c) is formed in a three-dimensional shape so that the transparent conductive film layer and the adhesive layer are formed one by one, and the protective sheet is covered to the side surface of the adhesive layer. (D) shows an example in which the base sheet, the transparent conductive film layer and the adhesive layer are formed in two layers, and the protective sheet is formed in a three-dimensional shape so as to cover the side surfaces of both adhesive layers. . BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic cross section which shows the manufacturing method of the transparent conductive film layer sheet | seat of this invention, (a) shows the example of a manufacturing method which laminates | stacks the protective sheet previously formed in three-dimensional shape so that the side surface of an adhesion layer may be coat | covered, (B) shows the example of a manufacturing method which laminates | stacks a protective sheet, processing to a solid shape so that the side surface of an adhesion layer may be followed, (c), after laminating | stacking a protection sheet, so that a protection sheet may be along the side surface of an adhesion layer The example of the manufacturing method to process is shown. It is a schematic cross section which shows one Example of the electrostatic capacitance type touch sensor using the double-sided transparent conductive film layer sheet | seat of this invention.

Referring to (a) of FIG. 1, a transparent conductive film layer sheet 5 of the present invention is a transparent conductive film layer sheet 5 in which an adhesive layer 4 is formed on one side (one side) of a substrate sheet 7. The protective sheet 1 is laminated on the surface (the other surface) opposite to the layer 4 formation surface. The transparent conductive film layer sheet 5 includes a base sheet 7, a transparent conductive film layer 3 formed on one surface of the base sheet 7, an adhesive layer 4 formed so as to cover the transparent conductive film layer 3, and a base And a protective sheet 1 laminated on the other surface of the sheet 7. With reference to (b) and (d) of FIG. 1, the transparent conductive film layer sheet 5 of another embodiment is
The base sheet 7 on which the transparent conductive film layer 3 and the adhesive layer 4 are formed is the adhesive layer 4 and the base sheet 7.
Are laminated so that and repeat alternately. A plurality of the base sheet 7 as described above may be laminated. In this case, the protective sheet 1 is laminated on the other surface of the base sheet 7 exposed on the outermost surface. Referring to FIGS. 1C and 1D, the transparent conductive film layer sheet 5 of still another embodiment is formed in a three-dimensional shape so that the protective sheet 1 is covered up to the side surfaces of all the adhesive layers 4. Has been. In addition, although the other member 10 is not specifically limited, For example, a glass base material etc. are mentioned.

The base sheet 7 is a sheet made of a material having an in-plane retardation value Re of 20 nm or less at a wavelength of 550 nm, and preferably has a thickness of about 30 to 2000 μm. If the in-plane retardation value Re exceeds 20 nm, there is a problem that when a display is installed in the lower part, the color is different from the color emitted from the display, or color unevenness occurs. Examples of materials that can reduce the in-plane retardation value Re to 20 nm or less include plastic films such as polycarbonate resins, polyarylate resins, cellulose resins, norbornene resins, polystyrene resins, olefin resins, and acrylic resins. . Among these, polycarbonate resins are particularly preferable because the in-plane direction retardation value Re can be set to 5 nm or less by making the film forming conditions suitable.

Retardation is a phenomenon in which light incident on a crystal or other anisotropic material is divided into two light waves having vibration directions perpendicular to each other. When non-polarized light is incident on a material having birefringence, the incident light is divided into two. Both of the vibration directions are perpendicular to each other, one is called vertically polarized light and the other is called horizontally polarized light. The vertical ray is an extraordinary ray, the horizontal ray is an ordinary ray, the ordinary ray is a ray whose propagation speed does not depend on the propagation direction, and the extraordinary ray is a ray having a different speed depending on the propagation direction. In a birefringent material, there is a direction in which the velocities of these two rays coincide with each other, and this is called an optical axis. The in-plane retardation value Re is the refractive index in the slow axis direction in the in-plane direction of the base sheet 7 as n.
x is a value calculated by (nx−ny) × d, where ny is the refractive index in the fast axis direction in the in-plane direction of the base sheet 7 and d is the thickness of the base sheet 7.

However, many of the above-mentioned plastic films having a low in-plane retardation value Re including polycarbonate-based resin easily transmit water vapor because of its high water vapor permeability. The transparent conductive layer 3 also has a problem of whitening. Therefore, in the present invention, the protective sheet 1 is laminated on the surface opposite to the surface on which the pressure-sensitive adhesive layer 4 is formed to block the entry of water vapor from the back surface, thereby preventing the whitening of the pressure-sensitive adhesive layer 4 and the like. Here, the high water vapor permeability means that the water vapor permeability of the entire sheet is 10 g / m ² · day when measured under the conditions of a temperature of 40 ° C. and a humidity of 90% in accordance with the method B of JISK7129. The case where it becomes above is shown.

The protective sheet 1 is a sheet made of a material having a water vapor barrier property and has a thickness of 30 to 20.
About 00 μm is preferable. Examples of such materials include plastic films such as cycloolefin resins and films provided with inorganic films such as silicon oxide. Among these, a cycloolefin-based resin film is particularly preferable because it not only has a high water vapor barrier property, but also has a low in-plane retardation value Re and is easily three-dimensionally processed. Here, the water vapor barrier property means that the water vapor permeability is 1 g / (m ² · day · atm) or less when measured under the conditions of a temperature of 40 ° C. and a humidity of 90%.

Examples of the transparent conductive film layer 3 include metal oxides such as indium tin oxide and zinc oxide, and layers composed of resin binders, carbon nanotubes, metal nanowires, and the like, and include vacuum deposition, sputtering, and ion plating. It may be formed by a general printing method such as a plating method, gravure, screen, or offset, a method using various coaters, a method such as painting or dipping. The thickness is preferably about several tens of nm to several μm, and preferably has a light transmittance of 80% or more and a surface resistance value of several mΩ to several hundreds Ω.

Examples of the adhesive layer 4 include layers made of acrylic resin, polyurethane resin, vinyl resin, rubber resin, etc., such as general-purpose printing methods such as gravure, screen, and offset, methods using various coaters, painting, dipping, etc. It may be formed by a method. The thickness is preferably about several μm to several tens of μm, and preferably exhibits strong adhesiveness and various resistances. However, an adhesive layer having excellent adhesiveness and various resistances usually has a problem of whitening by adsorbing moisture.

In the above example, the case where the base sheet 7 and the adhesive layer 4 are one layer each is shown (FIG. 1A).
2) These layers may be laminated two or more layers (see FIG. 1B). In the present invention, the protective sheet 1 is laminated on the base sheet 7.
However, as long as it satisfies the required characteristics of the base sheet 7, the protective sheet 1 may be provided in place of the base sheet 7, and the transparent conductive film layer 3, the adhesive layer 4, etc. may be provided directly on the protective sheet 1. In such a case, the base sheet 7 becomes unnecessary, which is more efficient.

When the base sheet 7 is laminated with the protective sheet 1, the adhesive layer 4 on the back surface as well as the surface thereof is used.
If the structure is such that the side surface is covered (see FIG. 1C), the effect of preventing whitening is further improved. And when the base sheet 7 and the adhesive layer 4 are laminated | stacked by two or more layers, if it is set as the structure which coat | covers to the side of all those layers (refer FIG.1 (d)), the effect of preventing whitening more. Will improve.

As a method of processing the protective sheet 1 into a structure that covers the side surface of the adhesive layer 4 on the back surface, the protective sheet 1 formed in a three-dimensional shape in advance so as to cover the side surface of the adhesive layer 4 or the like is applied to the base sheet 7. A method of laminating (see FIG. 2A), a method of laminating the protective sheet 1 on the base sheet 7 while processing it into a three-dimensional shape so as to extend to the side surfaces of the adhesive layer 4 and the like (see FIG. 2B),
And a method of processing the protective sheet 1 along the side surface of the adhesive layer 4 and the like (see FIG. 2C).

Examples of the method for forming the protective sheet 1 into a three-dimensional shape in advance so as to cover the side surfaces of the adhesive layer 4 and the like include press molding, vacuum molding, and pressure molding. Examples of a method of laminating the protective sheet 1 formed in a three-dimensional shape on the base sheet 7 include a method of laminating via an adhesive or the like.

As a method of laminating the protective sheet 1 on the base sheet 7 while processing it into a three-dimensional shape so as to extend to the side surface of the adhesive layer 4 or the like, the protective sheet 1 is heated to a softening temperature or higher so that the protective sheet 1 is softened. For example, a method of bringing the protective sheet 1 to the side surface of the pressure-sensitive adhesive layer 4 by pressing with a rubber-like pressing material 15 such as a silicon pad can be used.

As a method of processing the protective sheet 1 along the side surface of the adhesive layer 4 and the like after the protective sheet 1 is laminated on the base sheet 7, a hydroforming method of spraying high-pressure water 18 or the like on the attached protective sheet 1 or the like Is mentioned.

The transparent conductive film layer sheet 5 may be appropriately provided with a pattern layer for improving the appearance design. For the pattern layer, it is preferable to use colored ink containing a resin such as polyvinyl, polyamide, polyacrylic, polyurethane, or alkyd as a binder and a pigment or dye of an appropriate color as a colorant. In addition, metal particles such as aluminum, titanium, bronze, and pearl pigments in which mica is coated with titanium oxide can also be used as the colorant. As a method for forming the pattern layer, there are general printing methods such as gravure, screen, and offset, various coating methods, and methods such as painting.

Referring to FIG. 2A, as one method for producing the transparent conductive film layer sheet 5, a step of forming the transparent conductive film layer 3 on one surface of the base sheet 7 and the transparent conductive film layer 3 are covered. In this way, there is a type that includes the step of forming the pressure-sensitive adhesive layer 4 and the step of laminating the protective sheet 1 previously formed in a three-dimensional shape so as to cover the side surface of the pressure-sensitive adhesive layer 4 on the other side of the base sheet 7. . 2B, a step of forming the transparent conductive film layer 3 on one surface of the base sheet 7, a step of forming the adhesive layer 4 so as to cover the transparent conductive layer 3, and the base There is one provided with a step of laminating the protective sheet 1 on the other surface of the sheet 7 while processing it into a three-dimensional shape so as to follow the side surface of the adhesive layer 4. Furthermore, with reference to (c) of FIG. 2, the process of forming the transparent conductive film layer 3 in the one surface of the base sheet 7,
A step of forming the adhesive layer 4 so as to cover the transparent conductive film layer 3; a step of laminating the protective sheet 1 made of a material having a water vapor barrier property on the other surface of the base sheet 7; And a process of processing along the side surface. When manufacturing the transparent conductive film layer sheet | seat with which the transparent conductive film layer 3 and the adhesion layer 4 were laminated | stacked two or more, the process until the process before laminating | stacking the protective sheet 1 is repeated.

And if the transparent conductive film layer 3 formed on the transparent conductive film layer sheet 5 obtained by the above method is connected to the external circuit 28 on which the IC chip is mounted via a routing circuit, severe moisture resistance conditions A capacitive touch sensor 20 that can withstand even under the conditions can be created (see FIG. 3).

(1) Production of transparent conductive film layer sheet A polycarbonate resin film having a thickness of 50 μm is used as a base sheet, and a transparent conductive film layer made of indium tin oxide is formed on the surface thereof by sputtering to a thickness of 200 nm. Ten sets of transparent conductive layer sheets each having a polyurethane adhesive layer formed thereon by screen printing were prepared.

Next, five sets of the transparent conductive film layer sheets are heated to 150 ° C. while a protective sheet made of a cycloolefin resin film having a softening temperature of 120 ° C. is laminated on the surface opposite to the adhesive layer forming surface of the base sheet. The protective sheet was pressed from the back with a silicone pad. The area to be pressed by the silicon pad was set larger than the size of the base sheet, and the protective sheet was softened by pressing and was laminated along the side surfaces of the base sheet and the adhesive layer. The remaining 5 sets were not laminated with protective sheets.

(2) Resistance evaluation of transparent conductive film layer sheet 5 sets obtained by laminating the above protective sheets and 5 sets not laminated, 60 ° C. and 90 R
When placed in a humidity tester of H% and checked the surface condition after being left for 10 days, all 5 sets with protective sheets laminated were not abnormal, but all 5 sets without lamination were whitened. In one set, the transparent conductive film layer was also slightly whitened.

(1) Production of transparent conductive film layer sheet A polycarbonate resin film having a thickness of 50 μm is used as a base sheet, and a transparent conductive film layer made of indium tin oxide is formed on the surface thereof by sputtering to a thickness of 200 nm. After forming a polyurethane-based pressure-sensitive adhesive layer by screen printing, 10 sets of transparent conductive film layer sheets obtained by laminating them were prepared.

On the other hand, a cycloolefin-based resin film having a softening temperature of 120 ° C. was heated to 160 ° C., and a three-dimensional protective sheet having a rise of about 200 μm on the outer periphery was prepared by press molding. Next, an epoxy adhesive is applied to the inner surface of the three-dimensional protective sheet for five sets of the transparent conductive film layer sheet, and from the side opposite to the pressure-sensitive adhesive layer forming surface of the laminated lowermost base sheet. A protective sheet was attached. The area of the inner surface of the protective sheet matches the outer size of the base sheet, and the lowermost base sheet is covered with the protective sheet by pasting, and the side face of the upper base sheet and the side face of the adhesive layer are also covered. It was done. The remaining 5 sets were not laminated with protective sheets.

(2) Resistance evaluation of transparent conductive film layer sheet 5 sets with the above protective sheet attached and 5 sets not attached with 60
When placed in a humidity resistance tester at 90 ° C. 90 ° C. and confirmed the surface condition after standing for 10 days, all the 5 sets with the protective sheet attached had no abnormality, but all 5 sets with the protective sheet attached had an adhesive layer. The white color of the transparent conductive film layer was considerably whitened for 3 sets.

(1) Production of transparent conductive film layer sheet A polycarbonate resin film having a thickness of 50 μm is used as a base sheet, and a transparent conductive film layer made of indium tin oxide is formed on the surface thereof by sputtering to a thickness of 200 nm. After forming a polyurethane-based pressure-sensitive adhesive layer by screen printing, 10 sets of transparent conductive film layer sheets obtained by laminating them were prepared.

Next, a protective sheet made of a cycloolefin-based resin film having a softening temperature of 120 ° C. is bonded to the surface opposite to the adhesive layer-forming surface of the laminated lower base sheet on the five sets of the transparent conductive layer sheet. It was pasted through the agent. The protective sheet is set to be larger than the outer size of the base sheet, and the outer peripheral portion of the protective sheet was not adhered in the above-described pasting process, but the protective sheet was then subjected to hydroforming with high-pressure running water. The outer peripheral portion of the substrate was attached along the side surfaces of the upper substrate sheet and the adhesive layer. The remaining 5 sets were not laminated with protective sheets.

(2) Resistance evaluation of transparent conductive film layer sheet 5 sets with the above protective sheet attached and 5 sets not attached with 60
When placed in a humidity resistance tester at 90 ° C. 90 ° C. and confirmed the surface condition after standing for 10 days, all the 5 sets with the protective sheet attached had no abnormality, but all 5 sets with the protective sheet attached had an adhesive layer. Is whitened, and in one set, the transparent conductive film layer is considerably whitened.

DESCRIPTION OF SYMBOLS 1 Protective sheet 3 Transparent conductive film layer 4 Adhesive layer 5 Transparent conductive film layer sheet 7 Base sheet 10 Other members 20 Capacitive touch sensor 12 Protective sheet peripheral processing part 15 Pressing material 18 High-pressure water 28 External circuit

Claims (4)

It is a transparent conductive film layer sheet that prevents color unevenness when a display is installed at the bottom,
From a base sheet made of any of polycarbonate resin, polyarylate resin, cellulose resin, norbornene resin, polystyrene resin, olefin resin, and acrylic resin, and indium tin oxide formed on the base sheet a transparent conductive film layer formed, said a transparent conductive film layer sheet provided with an adhesive layer so as to cover the transparent conductive layer, a protective sheet is laminated and the adhesive layer of an acrylic resin, polyurethane resin, vinyl A transparent conductive film layer sheet for a touch sensor in which the adhesive layer is prevented from being whitened by water vapor by using either a resin or a rubber-based resin. It is a transparent conductive film layer sheet that prevents color unevenness when a display is installed at the bottom,
From a base sheet made of any of polycarbonate resin, polyarylate resin, cellulose resin, norbornene resin, polystyrene resin, olefin resin, and acrylic resin, and indium tin oxide formed on the base sheet a transparent conductive film layer formed, said a transparent conductive film layer sheet provided with an adhesive layer so as to cover the transparent conductive layer, a protective sheet is laminated and the adhesive layer of an acrylic resin, polyurethane resin, vinyl A transparent conductive film layer sheet for a touch sensor in which the adhesive layer and the transparent conductive film layer are prevented from being whitened by water vapor by using either a resin or a rubber-based resin. The transparent conductive film layer sheet for touch sensors of Claim 1 and Claim 2 with which the said protective sheet was formed in the surface on the opposite side to the adhesion layer formation surface of the said base sheet. The electrostatic capacitance type touch sensor using the transparent conductive film layer sheet for touch sensors in any one of Claims 1-3.

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