JP2014136386A - Double-sided electroconductive film, touch panel containing double-sided electroconductive film roll and double-sided electroconductive film, and method for producing double-sided electroconductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided electroconductive film which has excellent uniformity in film quality and film thickness and excellent flatness and exhibits excellent adhesiveness to metal layers and to provide a double-sided electroconductive film roll and a method for producing the double-sided electroconductive film, in which the double-sided electroconductive film can be produced by using a comparatively small-sized facility and the production yield of which is improved.SOLUTION: The double-sided electroconductive film is constituted so that light-transmissive support layers (A) of two light-transmissive electroconductive films, each of which contains a light-transmissive support layer (A) and a light-transmissive electroconductive layer (B), are made adjacent to each other while interposing an adhesive layer (C) therebetween. The adhesive layer (C) is formed from a reaction-curable adhesive.

Description

  The present invention relates to a double-sided conductive film, a double-sided conductive film roll, a touch panel containing a double-sided conductive film, and a method for producing a double-sided conductive film.

  Capacitance-type light-transmissive touch sheet panels (touch panels) represented by smartphones have a greater emphasis on detection accuracy and display performance at the beginning of commercialization. Therefore, glass is used as a support layer and conductive layers on both sides. A double-sided conductive film provided with a film was used (Patent Document 1).

  However, the double-sided conductive film using this glass as a support layer has problems in terms of weight, impact resistance, productivity, and price. Therefore, instead of glass, a plastic double-sided conductive film using plastic as a support layer has been put to practical use, and the above problems have been improved. However, it is inevitable that the double-sided conductive film using plastic as a support layer has a structure in which a plurality of types of films are combined with a bonding material. For this reason, a new problem has arisen in that the detection accuracy deteriorates due to such a structure itself and / or a processing assembly process for obtaining such a structure.

  For this reason, attempts have been made to improve the deterioration of detection accuracy by reducing the number of parts and the processing / assembly process. As one directionality, a method has been proposed in which two single-sided conductive films having a conductive layer provided on one side of a plastic support layer are prepared and bonded together with an adhesive to obtain a double-sided conductive film. (Patent Document 2). As another directionality, there has been proposed a means for obtaining a double-sided conductive film by providing conductive layers on both sides of a plastic support layer (Patent Document 3).

JP 2010-9594 A JP 2012-146297 A JP-A-8-272530

  In the conventional means of obtaining a double-sided conductive film by sticking single-sided conductive films to each other with an adhesive, the present inventors have a high film due to variations in the distance between the upper and lower electrodes. It has been found that there is a problem that it is difficult to ensure accurate operation.

  Furthermore, the present inventors, when the metal layer is laminated on the surface of the film for the purpose of using as a lead line (also called a lead electrode) for connecting the control circuit, It has also been found that the adhesion deteriorates.

  Further, in the conventional means of obtaining a double-sided conductive film by providing conductive layers on both sides of a plastic support layer, the inventors have formed a conductive layer on both sides simultaneously when actually manufactured. Found that very large-scale equipment was required. In addition, in this conventional means, if the conductive layers are sequentially formed on each side, it can be formed using conventional ordinary equipment. However, in this case, the production yield is extremely deteriorated. I found out. The inventors have also found that the double-sided conductive film thus obtained has a problem that it is difficult to ensure the uniformity of the film quality.

  Accordingly, the present invention provides a double-sided conductive film and a double-sided film that are excellent in film quality (film quality) and film thickness (film thickness) uniformity, flatness, and adhesion to a metal layer. It is an object to provide a conductive film roll.

  Furthermore, another object of the present invention is to provide a method for producing a double-sided conductive film, which can be produced by a relatively small-scale facility and has an improved production yield.

  The inventors of the present invention have made extensive studies in order to solve the above problems, and the double-sided conductive film obtained by laminating two conductive films by a dry laminating method using a reaction curable adhesive has a film quality. In addition, the present inventors have newly found that the film has excellent uniformity in film thickness, flatness, and excellent adhesion to the metal layer. Furthermore, the present inventors have newly found that a double-sided conductive film can be produced by using this production method with a relatively small-scale facility and with an improved production yield.

The present invention has been completed by further studies based on these new findings, and is as follows.
Item 1
Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A double-sided conductive film adjacent through layers,
The double-sided conductive film, wherein the adhesive layer (C) is formed from a reactive curable adhesive.
Item 2
Item 2. The double-sided conductive film according to Item 1, which can be obtained by bonding the two light-transmitting conductive films to each other by a dry laminating method using the reaction-curable adhesive.
Item 3
Item 3. The double-sided conductive film according to Item 1 or 2, wherein the adhesive layer (C) has a thickness of 1 to 10 μm.
Item 4
further,
(D) Item 1-3 which contains a hard-coat layer and the said hard-coat layer (D) is arrange | positioned between the said transparent support layer (A) and the said transparent conductive layer (B). The double-sided conductive film according to any one of the above.
Item 5
On at least one side,
(E) The double-sided conductive film in any one of claim | item 1 -4 by which the metal layer is arrange | positioned.
Item 6
A film roll formed by winding a double-sided conductive film having a width of 0.2 to 2.0 m and a length of 10 to 1000 m, and satisfying the following requirements (I) and (II):
(I) The double-sided conductive film is
Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A double-sided conductive film adjacent through layers,
The adhesive layer (C) is formed from a reactive curable adhesive; and (II) obtained by measuring at any 25 points arranged in a 5 × 5 square lattice at 25 mm intervals in the film roll. The film thickness satisfies the following formula (1).
(T _max −t _min ) / (t _ave ) × 100 <2.0 (1)
(In the above, t _max , t _min, and t _ave are the maximum value, minimum value, and average value of the film thickness obtained by measurement at the 25 points, respectively)
Item 7
The touch panel containing the double-sided conductive film in any one of claim | item 1 -5.
Item 8
Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A method for producing a double-sided conductive film adjacent through a layer,
A method comprising a step of bonding the two light-transmitting conductive films to each other by a dry laminating method using a reaction curable adhesive.

  According to the present invention, in a double-sided conductive film and a double-sided conductive film roll, optical characteristics, film quality and film thickness uniformity, and flatness are improved, and generation of volatile components and low molecular compounds from the film is suppressed. be able to.

  Furthermore, according to the present invention, in the method for producing a double-sided conductive film having excellent optical characteristics, it is possible to produce with a relatively small facility and to improve the production yield.

  Further, according to the present invention, excellent detection accuracy can be achieved in the touch panel.

The surfaces of the light transmissive support layers (A) of the two light transmissive conductive films in which the light transmissive conductive layer (B) is disposed adjacent to one side of the light transmissive support layer (A) are It is sectional drawing which shows the double-sided electroconductive film of this invention which adjoins via the contact bonding layer (C) directly. Light transmission of two light transmissive conductive films in which a hard coat layer (D) and a light transmissive conductive layer (B) are arranged adjacent to each other in this order on one side of the light transmissive support layer (A) It is sectional drawing which shows the double-sided electroconductive film of this invention with which the surfaces of a conductive support layer (A) are adjacent via the contact bonding layer (C) directly.

1. Double-sided conductive film of the present invention The double-sided conductive film of the present invention is
Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A double-sided conductive film adjacent through layers,
The adhesive layer (C) is formed from a reactive curable adhesive.

  In the present invention, “light-transmitting” means having a property of transmitting light (translucent). “Light transmissivity” includes transparency. “Light transmissivity” means, for example, the property that the total light transmittance is 80% or more, preferably 85% or more, more preferably 87% or more.

  In the present invention, the thickness of each layer is determined by observation using a commercially available transmission electron microscope (JEM-1400 manufactured by JEOL Ltd., or an equivalent product thereof). Specifically, the light-transmitting conductive film is thinly cut in a direction perpendicular to the film surface using a microtome or a focus ion beam, and the cross section is observed.

  In FIG. 1, the one aspect | mode of the double-sided conductive film of this invention is shown. In this aspect, the light transmissive support layer (A) of the two light transmissive conductive films in which the light transmissive conductive layer (B) is disposed adjacent to one side of the light transmissive support layer (A). The surfaces are adjacent via the adhesive layer (C) directly.

1.1 Light transmissive conductive film 1.1.1 Light transmissive support layer (A)
In the present invention, the light-transmitting support layer refers to a light-transmitting conductive film containing a light-transmitting conductive layer that plays a role of supporting a layer including the light-transmitting conductive layer. Although it does not specifically limit as a light transmissive support layer (A), For example, in the light transmissive conductive film for touch panels, what is normally used as a light transmissive support layer can be used.

  Although the raw material of a light-transmissive support layer (A) is not specifically limited, For example, various organic polymers etc. can be mentioned. The organic polymer is not particularly limited. For example, polyester resin, acetate resin, polyether resin, polycarbonate resin, polyacrylic resin, polymethacrylic resin, polystyrene resin, polyolefin resin, polyimide resin, etc. Examples include resins, polyamide resins, polyvinyl chloride resins, polyacetal resins, polyvinylidene chloride resins, and polyphenylene sulfide resins. Although it does not specifically limit as polyester-type resin, For example, a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN), etc. are mentioned. The material of the light transmissive support layer (A) is preferably a polyester resin, and particularly preferably PET. The light transmissive support layer (A) may be composed of any one of these, or may be composed of a plurality of types.

  Although the thickness of a light-transmissive support layer (A) is not specifically limited, For example, the range of 2-300 micrometers is mentioned.

1.1.2 Light transmissive conductive layer (B)
In the present invention, the light-transmitting conductive layer means a layer that conducts electricity and transmits visible light. Although it does not specifically limit as a light transmissive conductive layer (B), For example, what is normally used as a light transmissive conductive layer in the light transmissive conductive film for touch panels can be used.

  The light transmissive conductive layer (B) contains a light transmissive conductive material.

  The light transmissive conductive material is not particularly limited, and examples thereof include indium oxide, zinc oxide, tin oxide, and titanium oxide. The light transmissive conductive material may be composed of any one of them, or may be composed of a plurality of types. As the light-transmitting conductive material, those light-transmitting conductive materials doped with a dopant are preferable, and in particular, indium oxide doped with a dopant is particularly preferable in terms of achieving both transparency and conductivity. Although it does not specifically limit as a dopant, For example, a tin oxide, a zinc oxide, those mixtures, etc. are mentioned.

In the case of using indium oxide doped with tin oxide as the light-transmitting conductive material, tin-IV oxide (SnO ₂ ) doped with indium (III) oxide (In ₂ O ₃ ) (tin-doped oxide) ITO) is preferred. In this case, the addition amount of SnO ₂ is not particularly limited, and examples thereof include 1 to 15% by weight, preferably 2 to 10% by weight, and more preferably 3 to 8% by weight. Moreover, you may use as a raw material of a transparent conductive layer (B) what added the other dopant to ITO in the range which the total amount of a dopant does not exceed the numerical range of the left description. Although it does not specifically limit as another dopant in the left, For example, selenium etc. are mentioned.

  The light transmissive conductive layer (B) may contain any one of the above various light transmissive conductive materials, or may contain a plurality of types.

  The light-transmitting conductive material is not particularly limited, and may be a crystalline body, an amorphous body, or a mixture thereof.

  The thickness of the light transmissive conductive layer (B) is not particularly limited, but is usually 5 to 50 nm. The thickness of the light transmissive conductive layer (B) is preferably 10 to 40 nm, more preferably 12 to 35 nm, and still more preferably 15 to 30 nm.

  The method of disposing the light transmissive conductive layer (B) may be either wet or dry.

  Examples of the method for arranging the light transmissive conductive layer (B) include a sputtering method, a vacuum deposition method, an ion plating method, a CVD method, and a pulse laser deposition method.

1.1.3 Hard coat layer (D)
In the light transmissive conductive film of the present invention, the hard coat layer (D) may be disposed between the light transmissive support layer (A) and the light transmissive conductive layer (B). The hard coat layer (D) is preferably disposed adjacent to the light transmissive support layer (A). When the hard coat layer (D) is disposed, at least one of the light transmissive conductive layers (B) is disposed on the surface of the light transmissive support layer (A) via at least the light hard coat layer (D). Is arranged. In this case, at least one of the light transmissive conductive layers (B) may be disposed adjacent to the hard coat layer (D).

  One layer of the hard coat layer (D) may be disposed. Alternatively, two or more layers may be arranged adjacent to each other or separated from each other via other layers.

  The hard coat layer (D) may be disposed on both surfaces of the light transmissive support layer (A).

  In FIG. 2, the one aspect | mode of the double-sided conductive film containing the hard-coat layer (D) of this invention is shown. In this embodiment, the two light-transmissive conductive layers in which the hard coat layer (D) and the light-transmissive conductive layer (B) are arranged adjacent to each other in this order on one side of the light-transmissive support layer (A). The surfaces of the light transmissive support layer (A) of the film are adjacent to each other through the adhesive layer (C).

  In the present invention, the hard coat layer means a layer that prevents the plastic surface from being damaged. Although it does not specifically limit as a hard-coat layer (D), For example, what is normally used as a hard-coat layer in the transparent conductive film for touchscreens can be used.

  The material of the hard coat layer (D) is not particularly limited, and examples thereof include acrylic resins, silicone resins, urethane resins, melamine resins, and alkyd resins. The hard coat layer (D) may be composed of any one of them, or may be composed of a plurality of types. The hard coat layer (D) may contain inorganic fine particles for the purpose of adjusting the refractive index. The inorganic fine particles are not particularly limited, and examples thereof include silica, zirconia, titania, and alumina. As the hard coat layer (D), an acrylic resin in which zirconia particles are dispersed is preferable.

  Although the thickness per layer of the hard coat layer (D) is not particularly limited, examples thereof include 0.1 to 10 μm, 1 to 7 μm, preferably 2 to 6 μm. When two or more layers are disposed adjacent to each other, the total thickness of all the hard coat layers (D) adjacent to each other may be within the above range.

  The refractive index of the hard coat layer (D) is not particularly limited as long as the light-transmitting conductive film of the present invention can be used as a light-transmitting conductive film for a touch panel, and examples thereof include 1.4 to 1.7. It is done.

  The JIS pencil hardness of the hard coat layer (D) is not particularly limited as long as the effects of the present invention can be obtained. However, in terms of imparting good hardness to the entire film and suppressing curl. If it is above, it is preferable, and if it is 3H or more, more preferable. The JIS pencil hardness of the hard coat layer (D) is usually 8H or less, but 6H or less is preferable from the viewpoint of ensuring the flexibility of the light-transmitting conductive film.

  The method of disposing the hard coat layer (D) is not particularly limited, and examples thereof include a method of applying to a film and curing with heat, a method of curing with active energy rays such as ultraviolet rays and electron beams, and the like. From the viewpoint of productivity, a method of curing with ultraviolet rays is preferable.

1.1.4 Light transmissive underlayer (F)
The light transmissive conductive film of the present invention is light transmissive either directly or via one or more other layers on the surface of the light transmissive support layer (A) where the light transmissive conductive layer (B) is disposed. An underlayer (F) may be disposed. When the light-transmitting underlayer (F) is disposed, at least one of the light-transmitting conductive layers (B) passes through the light-transmitting underlayer (F) at least through the light-transmitting support layer (A). ). In this case, at least one of the light transmissive conductive layers (B) may be disposed adjacent to the light transmissive underlayer (F).

  The material of the light-transmitting underlayer (F) is not particularly limited, but may be a dielectric material, for example. The material of the light-transmitting underlayer (F) is not particularly limited, and examples thereof include silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon alkoxide, alkylsiloxane and its condensate, polysiloxane, silsesquioxy. Sun, polysilazane, etc. are mentioned. The light transmissive underlayer (F) may be composed of any one of them, or may be composed of a plurality of types. A light-transmitting underlayer containing silicon oxide is preferable, and a light-transmitting underlayer made of silicon oxide is more preferable.

One layer of the light-transmitting underlayer (F) may be disposed. Alternatively, two or more layers may be arranged adjacent to each other or separated from each other via other layers. Two or more light-transmitting underlayers (F) are preferably disposed adjacent to each other. For example, when two layers are arranged adjacent to each other, a light-transmitting underlayer (F-1) made of SiO ₂ on the light-transmitting support layer (A) side and SiO on the light-transmitting conductive layer (B) side. _It is preferable to dispose a light-transmitting underlayer (F-2) made of _x (x = 1.0 to 2.0).

  Examples of the thickness per layer of the light-transmitting underlayer (F) include 15 to 25 nm. When two or more layers are arranged adjacent to each other, the total thickness of all the light-transmitting underlayers (F) adjacent to each other may be within the above range.

  The refractive index of the light-transmitting underlayer (F) is not particularly limited as long as the light-transmitting conductive film of the present invention can be used as a light-transmitting conductive film for a touch panel, but for example, 1.45 to 1.55. preferable.

  Examples of the method for disposing the light-transmitting underlayer (F) include a dry method, for example, a method of laminating on an adjacent layer by a sputtering method, an ion plating method, a vacuum deposition method, a pulse laser deposition method, or the like. .

1.1.5 Other layers (G)
The light-transmitting conductive film of the present invention has a hard coat layer (D), a light-transmitting underlayer (in addition to the light-transmitting conductive layer (B) on the surface of the light-transmitting support layer (A). F) and at least one layer selected from the group consisting of at least one other layer (G) different from them may be further arranged.

  Other layers different from any of (A), (B), (D), and (F) are not particularly limited, and examples thereof include a coupling treatment layer and an anchor coat layer.

  The coupling treatment layer is a layer provided when it is necessary to further improve the adhesion between the light transmissive support layer (A) and the light transmissive conductive layer (B). Although it does not specifically limit as a coupling process layer, For example, what is normally used as a coupling process layer in the double-sided conductive film used for a touchscreen use can be used. The coupling treatment layer may be composed of any one of them, or may be composed of a plurality of types.

  The anchor coat layer is a layer provided in a difference where it is necessary to further improve the adhesive force between the light transmissive support layer (A) and the adhesive layer (C). Although it does not specifically limit as an anchor coat layer, For example, what is normally used as an anchor coat layer in the double-sided conductive film used for a touch-panel use can be used. The anchor coat layer may be composed of any one of these, or may be composed of a plurality of types.

1.1.7 Method for Producing Light-Transparent Conductive Film The method for producing a light-transmissive conductive film has a light-transmissive conductive layer (B) disposed on at least one surface of the light-transmissive support layer (A). Each of the steps.

  In the method for producing a light transmissive conductive film of the present invention, in addition to the light transmissive conductive layer (B), at least one surface of the light transmissive support layer (A), a hard coat layer (D), light transmissive A step of disposing at least one kind of layer selected from the group consisting of the conductive underlayer (F) and at least one other kind of other layer (G) different therefrom.

  The process of disposing each layer of the light transmissive conductive film is as described for each layer.

  In the case of arranging at least one other layer in addition to the light transmissive conductive layer (B), for example, the light transmissive support layer (A) side is provided on at least one surface of the light transmissive support layer (A). However, the order of arrangement is not particularly limited. For example, you may arrange | position another layer to one side of the layer (for example, light transmissive conductive layer (B)) which is not a light transmissive support layer (A) first. Alternatively, one composite layer is obtained by arranging two or more layers adjacent to each other on the one hand, or at the same time, two or more layers are similarly disposed adjacent to each other on the other side. Thus, one type of composite layer may be obtained, and these two types of composite layers may be further arranged adjacent to each other.

1.2 Adhesive layer (C)
The adhesive layer (C) is a layer formed from a reactive curable adhesive. In other words, the adhesive layer (C) is a layer that can be obtained by curing a reactive curable adhesive. Although not particularly limited, the adhesive layer (C) has a light-transmitting property by a method including a step of bonding the two light-transmitting conductive films to each other by a dry laminating method using a reaction curable adhesive. It may be a layer that can be formed between the conductive films. Regarding the dry lamination method, the following 3. As described later. The adhesive layer (C) having such a structure improves the uniformity and flatness of film quality and film thickness in the double-sided conductive film, and generates volatile components and low molecular compounds from the film. Can be suppressed.

  The reaction curable adhesive may be a solvent-based reaction curable adhesive or a solventless reaction curable adhesive. In terms of the thickness accuracy of the adhesive layer, a solvent-based reaction curable adhesive is more preferable.

  Regardless of whether the reaction-curable adhesive is a solvent-free reaction-curable adhesive or a solvent-based reaction-curable adhesive, those described below can be used. In addition, as a solvent type reaction curable adhesive, what melt | dissolved the main ingredient and hardening | curing agent of the reaction curable adhesive demonstrated below in a solvent can be used.

  Although it does not specifically limit as a reaction hardening type adhesive agent, For example, what is normally used in the dry laminating method can be used. Specifically, although not particularly limited, for example, at least selected from urethane-based resins, ester-based resins, ether-based resins, acrylic-based resins, epoxy-based resins, phenol-based resins, and silicone-based resins. Examples thereof include a reaction curable adhesive mainly composed of one kind of resin.

  The adhesive layer (C) of the present invention can be obtained by appropriately adding a curing agent to the above reactive curable adhesive main agent. Depending on the reaction mechanism of each reactive curable adhesive, a curing method such as thermal curing, photocuring, and electron beam curing can be selected. More specifically, the thermal curing method is preferable from the viewpoint of simplicity of production equipment and cost. Furthermore, an adhesive mainly composed of an ester-based resin and an ether-based resin is preferable from the viewpoints of transparency and ultraviolet resistance.

  As the solvent-based reaction curable adhesive, a solution obtained by dissolving the main component and the curing agent of the reaction curable adhesive in a solvent can be used. Although it does not specifically limit as a solvent, For example, toluene, xylene, hexane, ethyl acetate, benzene, etc. are mentioned. Among these, toluene and ethylene acetate and a mixed solvent containing them as main components are preferable in terms of productivity.

  The reaction curable adhesive can be selected from a wide range as long as the effect of the present invention can be obtained, but if the post-curing elastic modulus at room temperature 23 ° C. is 10 MPa to 1000 MPa, the film has good hardness. Is preferable in that it suppresses curling. In the same point, the reaction curable adhesive is more preferably one having an elastic modulus after curing at room temperature of 23 ° C. of 50 MPa to 500 MPa, and more preferably one having an elastic modulus of 100 MPa to 300 MPa.

  In the present invention, the post-curing elastic modulus is measured as follows. First, a sample is obtained by flowing and curing a reaction-curing adhesive to be measured in a container made of a release film so that the thickness after curing is about 1 millimeter, for example. Next, the sample is cut into a size suitable for a measuring apparatus described later to obtain a sample piece. This sample piece is measured by a tensile mode using a dynamic viscoelasticity measuring device (DMS7100 manufactured by Seiko Instruments Inc. or an equivalent thereof) to obtain a numerical value of elastic modulus.

  The thickness of the adhesive layer (C) can be widely selected within the range in which the effects of the present invention can be obtained, but is preferably 1 to 10 μm, and 2 to 5 μm in order to develop a stable adhesive force. It is more preferable if it is 3 to 4 μm.

  In a double-sided conductive film that is a laminate, if the difference in refractive index between layers becomes too large, an iridescent pattern will be observed on the film surface due to optical anisotropy, which is optically undesirable. . In the conventional means of obtaining a double-sided conductive film by bonding single-sided conductive films to each other with an adhesive, the refractive index difference between the plastic support layer and the adhesive layer in the finally obtained film The present inventors have made it clear that there is a problem that deterioration of display quality (color rendering and light transmission) due to optical interference is unavoidable.

  In the present invention, this problem can be solved by using the predetermined adhesive layer (C). That is, this problem can be solved by using an adhesive layer (C) having a refractive index difference at a wavelength of 590 nm with respect to the light transmissive support layer (A) of less than 0.1. When the refractive index difference of the adhesive layer (C) is within this range, the optical anisotropy of the entire film is suppressed, and the phenomenon that an iridescent pattern is observed on the film surface can be suppressed. In this respect, the refractive index difference of the adhesive layer (C) is more preferably less than 0.05, and even more preferably less than 0.02.

  The refractive index at a wavelength of 590 nm can be measured by an Abbe refractometer generally used in refractive index measurement. It is only necessary to measure the refractive index of a sample obtained by spreading a reaction curable adhesive, which will be described later, on the release film so that the thickness after curing is about 100 microns and curing.

  Further, in the conventional means of obtaining a double-sided conductive film by bonding single-sided conductive films to each other with an adhesive, when processing the obtained film as a touch panel, the volatile components and low molecules Since the compound is generated as a pollutant, it has been clarified by the present inventors that various harmful effects are caused.

  In the double-sided conductive film of the present invention, the generation of volatile components and low-molecular compounds from the film is suppressed by using an adhesive instead of an adhesive.

1.3 Metal layer (E)
In the double-sided conductive film of the present invention, a metal layer (E) may be disposed on at least one surface for the purpose of using it as an extraction line (also referred to as an extraction electrode) for connecting a control circuit. In the double-sided conductive film of the present invention, the metal layer (E) is disposed adjacent to the surface of the light-transmissive conductive layer (B) opposite to the light-transmissive support layer (A). Good.

  The metal layer (E) is a layer containing a metal. The metal layer (E) may be one normally used as a lead-out line, and is not particularly limited.

  The metal contained in the metal layer (E) may be any metal that can be used as a lead-out line, and can be selected widely. Although it does not specifically limit, For example, copper, nickel copper, silver, aluminum, molybdenum, etc. are mentioned. The metal layer (E) may contain these independently, and may contain 2 or more types. The metal layer (E) may further contain other components. Such other components are not particularly limited, and examples thereof include oxygen, nitrogen, hydrogen, and sulfur.

  For example, the metal layer (E) is disposed adjacent to one surface of the light transmissive conductive layer (B), and only the desired region of the metal layer (E) is removed by an etching process, whereby the light transmissive layer is formed. The region remaining on the surface of the conductive conductive layer (B) can be used as wiring. Thus, when utilizing as wiring, the metal layer (E) containing copper, nickel copper, silver, aluminum, molybdenum, etc. can be used.

  The method for forming the metal layer (E) on the surface is not particularly limited, but preferred methods include, for example, an ion plating method, a sputtering method, a vacuum deposition method, a CVD method, and a pulse laser deposition method. .

1.4 Use of Double-sided Conductive Film of the Present Invention The double-sided conductive film of the present invention can be used for the production of a capacitive touch sheet panel. The double-sided conductive film of the present invention can also be used for other applications. Other applications include, for example, the production of photovoltaic devices, electromagnetic shielding members, precision electronic equipment packaging containers, and the like.

  The double-sided conductive film of the present invention has a highly uniform spacing between the light-transmitting conductive layers on both sides facing each other, and is thus preferably used for the production of a high-performance capacitive touch panel. Details of the capacitive touch panel are as described in 4.

  In addition, the double-sided conductive film of the present invention in which the metal layer (E) is disposed on at least one side for the purpose of using it as a lead-out line for connecting the control circuit has two conductive layers through a conventional adhesive layer. Compared with a double-sided conductive film formed by laminating a conductive film, the adhesion with the metal layer (E) is improved. Therefore, the double-sided conductive film of the present invention is also preferably used as a double-sided conductive film provided with a metal layer (E) for the purpose of use as a lead-out line.

  Moreover, you may use the double-sided conductive film of this invention, after patterning a transparent conductive layer (B). Patterning is usually done by etching. The double-sided conductive film of the present invention has an excellent characteristic that generation of volatile components and low-molecular compounds is suppressed when etching is performed. Therefore, the double-sided conductive film of the present invention is also suitable for use in which the light-transmitting conductive layer (B) is patterned. Although the etching method is not particularly limited, for example, it is performed as follows. First, a resist (a protective film for protecting the layer from the etching solution) is applied to the region to be left on the light-transmitting conductive layer. The application means may be performed by screen printing depending on the type of the resist. If a photoresist is used, it is performed as follows. Apply the photoresist to the area you want to leave on the light-transmitting conductive layer using a spin coater or slit coater, etc., and partially irradiate light or an electron beam to change the solubility of the photoresist only in that area. Thereafter, the portion having relatively low solubility is removed (this is called development). In this way, the resist is present only in the region to be left on the light-transmitting conductive layer. Subsequently, an etching solution is allowed to act on the light-transmitting conductive layer to selectively dissolve a region of the light-transmitting conductive layer that is not protected by the resist, and finally, the dissolved matter is removed to thereby remove the pattern. Form.

2. Method for producing double-sided conductive film The method for producing a double-sided conductive film of the present invention comprises:
Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A method for producing a double-sided conductive film adjacent through a layer,
In this method, the two light-transmitting conductive films are bonded to each other by a dry laminating method using a reaction curable adhesive.

  This manufacturing method is characterized in that it includes a step of bonding together the light-transmitting conductive films already described by a dry laminating method using a reactive curable adhesive.

  The reaction curable adhesive is as described in 1.2 above.

  The dry laminating method is (1) a step of applying a reactive curable adhesive diluted in an organic solvent to one or both surfaces to be bonded, (2) a step of drying and volatilizing the solvent, (3) In a state where pressure is applied, a step of bonding the surface coated with the reactive curable adhesive to the other surface to be bonded, and (4) by heat and / or ultraviolet rays or an electron beam It is a method of sequentially containing a step of curing a reaction curable adhesive.

  The step (1) of applying the solvent-based reaction curable adhesive to one or both surfaces to be bonded is not particularly limited, but can be performed, for example, in the same manner as in a normal dry laminating method. . Although it does not specifically limit, For example, it can coat using a direct gravure coater, an offset gravure coater, a comma coater, a Mayer bar coater, a spray coater, a slot die coater, etc. Among these, a direct gravure coater and a slot die coater are preferable in terms of coating film thickness accuracy.

  The surface on which the solvent-based reaction curable adhesive is applied, if necessary, for one or more purposes such as improvement of adhesive strength, improvement of wettability and improvement of film thickness uniformity, etc. Processing may be performed. The surface treatment is not particularly limited, and examples thereof include corona treatment, plasma treatment, and primer treatment.

  In step (1), a solvent-based reaction curable adhesive is usually applied only to one surface to be bonded, but a solvent-based reaction curable adhesive is applied to both surfaces as necessary. You may apply.

The amount of the solvent-based reaction curable adhesive to be applied is not particularly limited, but can be the same as, for example, the coating amount in a normal dry laminating method. Type of solvent-based curable adhesive, and / or varies depending properties of bonded align it to the surface and conditions such as, for example, in terms of dried basis weight, the amount of 1g / m ² ~10g / m ² It is possible to apply a solvent-based reaction curable adhesive. From the standpoint of achieving both adhesive force uniformity and optical properties, it is preferable to apply a solvent-based reaction curable adhesive in an amount of ² g / m ^{2 to} 5 g / m ² .

  The step (2) for drying and volatilizing the solvent is not particularly limited, but can be performed, for example, in the same manner as in the usual dry laminating method. Although not particularly limited, for example, drying can be performed in an air atmosphere, a nitrogen gas atmosphere, an argon gas atmosphere, or the like. Of these, a nitrogen gas atmosphere and an argon gas atmosphere are preferable in terms of stable expression of properties after curing. Moreover, although drying in this process (2) is not specifically limited, For example, it can perform for 1 to 10 minutes at 80-120 degreeC.

  The step (3) of bonding the surfaces together in a state where pressure is applied is not particularly limited, but can be performed, for example, in the same manner as in a normal dry laminating method. Although it does not specifically limit, For example, you may carry out by passing between a pair of rolls installed facing each other.

  The step (4) of curing the reaction curable adhesive with heat and / or ultraviolet rays or an electron beam can be appropriately selected depending on the curing mechanism of the used adhesive. In the case of curing by heat, it is necessary to apply a sufficient temperature to cure the used adhesive, but it is important not to exceed the heat distortion temperature of the light transmissive support layer (A). When curing is performed with ultraviolet rays or radiation, heat can be applied simultaneously or sequentially. In order to further stabilize the physical properties after curing, curing may be performed for several hours to several days in a thermostatic bath at 30 ° C to 60 ° C.

3. Film roll of the present invention The film roll of the present invention is a film roll formed by winding a double-sided conductive film having a width of 0.2 to 2 m and a length of 10 to 1000 m. The following requirements (I) and (II) It is the film roll which satisfy | fills.
(I) The double-sided conductive film is
Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A double-sided conductive film adjacent through layers,
The adhesive layer (C) is formed from a reactive curable adhesive; and (II) obtained by measuring at any 25 points arranged in a 5 × 5 square lattice at 25 mm intervals in the film roll. The film thickness satisfies the following formula (1).
(T _max −t _min ) / (t _ave ) × 100 <2.0 (1)
(In the above, t _max , t _min, and t _ave are the maximum value, minimum value, and average value of the film thickness obtained by measurement at the 25 points, respectively)
In the above, the film thickness is obtained by measuring with a dial gauge. More specifically, this film thickness is obtained by measuring at a minimum unit of 0.1 μm using a dial gauge having a minimum scale of 1 μm.

The film roll of the present invention is preferable if the film thickness obtained by measurement at the 25 points satisfies the following formula (2).
(T _max −t _min ) / (t _ave ) × 100 <1.5 (2)
(In the above, t _max , t _min, and t _ave are as described in Equation (1)).

Furthermore, the film roll of this invention is more preferable if the film thickness obtained by measuring in said 25 points satisfy | fills following formula (3).
(T _max −t _min ) / (t _ave ) × 100 <1.0 (3)
(In the above, t _max , t _min, and t _ave are as described in Equation (1)).

  The film roll of the present invention can be obtained as follows. Using a film-winding dry laminator, apply adhesive to one light-transmitting conductive film, and after drying, press and bond with the other light-transmitting conductive film, and after passing through a curing process, paper Take up around a tube or plastic core. After winding, if necessary, it may be further cut by a slitter into a final form having a width of 0.2 to 2 m and a length of 10 to 1000 m.

  After the double-sided conductive film wound up in a roll shape is cut into a sheet shape, the sheet-like double-sided conductive film subjected to various processing as required can be used as a transparent electrode for a touch panel.

4). Touch Panel of the Present Invention The touch panel of the present invention includes the double-sided conductive film of the present invention, and further includes other members as necessary.

Specific examples of the configuration of the touch panel of the present invention include the following configurations. The protective layer (1) side is used so that the operation screen side faces, and the glass (5) side faces the side opposite to the operation screen.
(1) Protective layer (2) Double-sided conductive film of the present invention (Y-axis direction)
(3) Insulating layer (4) Double-sided conductive film of the present invention (X-axis direction)
(5) Glass Although the touch panel of this invention is not specifically limited, For example, it can manufacture by combining said (1)-(5) and another member according to a normal method as needed.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

  1. Evaluation of the product of the present invention was performed on the following items.

1.1 Evaluation items Uniformity of film thickness Starting from an arbitrary point on the produced double-sided conductive film, 25 points of 5 × 5 are measured in a grid of 25 mm intervals using a dial gauge with a minimum scale of 1 μm and a minimum unit of 0.1 μm. The film thickness uniformity was evaluated based on the percentage obtained by the following equation.

Film thickness uniformity% = ((t _max −t _min ) / t _ave average) × 100
In the above, t _max , t _min, and t _ave are the maximum value, minimum value, and average value of the film thickness obtained by measurement at the 25 points, respectively.

1.2 Evaluation items Optical performance Total light transmittance was evaluated using a light transmittance meter (Nippon Denshoku Industries Co., Ltd. NDH4000) based on JIS K7361. Measurement was performed by cutting out measurement pieces from arbitrary five locations, and the average value of the measurement results was evaluated as a representative value.

1.3 Evaluation items Touch panel operability The manufactured touch panel was installed in a smartphone, and sensory evaluation of the operability was performed. Target operations were tapping (lightly touching one point and releasing it immediately) and flicking (quickly touching the touched finger), and the sensory evaluation of detection reliability was performed in five stages for each operation.

1.4 Evaluation items Adhesion between metal layer and other layer The test was conducted in accordance with 8.5.3 adhesive cross-cut tape method of JIS K-5400-1990. An adhesive tape made by 3M (product number: 610) is attached to each film, and then the adhesive tape is peeled off from the film. Thus, evaluation was performed using the degree to which a part of the layer (D) or the layer (E) peeled as an index. Specifically, the appearance of the peeled piece adhered to the tape side was observed, and it was determined whether it corresponds to any of the peel ranks 0 to 5 based on the criteria defined in the JIS tape method. “Peeling rank 0” corresponds to a state where “the cut edges are completely smooth and none of the squares of the lattice are peeled off”. “Peeling rank 1” corresponds to a state “a small flake-like peeling is seen at the intersection of cuts. 5% or less of the cross-cut area is affected”. “Peeling rank 2” means that “a flake-like peeling of the coating is seen along the point where the edges or cuts meet. More than 15% are affected in the crosscut area, but more than 15%. It corresponds to the “nothing” state. “Peeling rank 3” is “flakes off partly or entirely along the edge of the cut, or a part of the square is partially or completely peeled off. 15 in the cross cut area % And 35% or less are affected ”. “Peeling rank 4” is “The coating is partially or entirely flaked off along the edge of the cut. Part or all of the square part is peeled off. 35% or more of the cross-cut area, 65% or more are affected ”. Further, the “peeling rank 5” corresponds to a state of “there is no peeling in the peeling rank 4 and further peeling occurs”.

2.1 Example 1 Preparation of Double-sided Conductive Film of the Present Invention A polyethylene terephthalate film having a thickness of 50 μm was prepared as the light transmissive support layer (A). It was 1.610 when the refractive index in wavelength 590nm of this film was measured with the Abbe refractometer.

  A light transmissive conductive layer (B) made of ITO with an Sn addition amount of 5% by weight is formed on one surface of the light transmissive support layer (A) using a DC magnetron sputtering apparatus. Two light transmissive conductive films containing A) and a light transmissive conductive layer (B) were obtained.

  As a result of observing a vertical cross section of the light transmissive conductive film with a transmission electron microscope, the film thickness (thickness of the ITO layer) was 30 nm. Moreover, it was 200 ohms / square when the surface electrical resistance value of this light transmissive conductive film was measured with the surface resistance meter.

Next, a thermosetting adhesive main agent (manufactured by Mitsui Chemicals, product name: Takelac A520) and a curing agent (manufactured by Mitsui Chemicals, product name: Takenate A50) are used as the adhesive layer (C) in a weight ratio of 6: 1. And further diluted with ethyl acetate to a solid content concentration of 25% by weight to prepare an adhesive solution. This adhesive solution was applied to the surface of one light transmissive support layer (A) of the light transmissive conductive film using a Mayer bar # 8 so that the amount applied was approximately 12 g / m ^2. Then, it was dried in a hot air dryer adjusted to 80 ° C. for 1 minute to remove the solvent. Further, the light-transmitting support layer (A) side surface of the other light-transmitting conductive film is bonded to the surface on the adhesive layer (C) side, and again in the above-described hot air dryer. After holding for a minute, curing was performed at 45 ° C. for 96 hours to obtain a double-sided conductive film of the present invention.

  When the thickness of the adhesive layer (C) of the double-sided conductive film thus obtained was measured by cross-sectional observation, it was approximately 2.8 μm.

  The properties of the adhesive layer (C) were evaluated as follows. The above adhesive solution was cast on a release film and dried and cured to obtain a sample piece. The curing conditions and curing conditions were the same as the conditions for manufacturing the double-sided conductive film. As a result of measuring the elastic modulus and the refractive index based on the obtained sample piece, the elastic modulus was 200 MPa and the refractive index was 1.560.

  A touch panel was produced as follows. The light-transmitting conductive layer (A) of the double-sided conductive film produced as described above is subjected to a crystallization treatment at 150 ° C. for 60 minutes using a hot air dryer, and then a capacitive touch panel using a chemical etching method. Patterning generally used as the above, and processed into upper and lower touch panel electrodes for 3.5 inch display. Subsequently, the wiring was printed with silver ink, the upper and lower touch panel electrode films were bonded together, and the connection to the driving element was performed to complete the touch panel.

  The evaluation results are shown in Table 1. In addition, each evaluation produced 5 samples of the double-sided conductive film of this invention as mentioned above, and performed each about these 5 samples.

2.2 Example 2
A double-sided conductive film of the present invention was obtained in the same manner as in Example 1 except that the conditions were as follows.

  On the light transmissive support layer (A), a hard coat layer (D), a base layer (F) and a light transmissive conductive layer (B) are sequentially laminated to obtain two light transmissive conductive films, These were laminated by a solvent-type dry laminating method.

2.2.1 Light transmissive support layer (A)
Material: Polycycloolefin film Thickness: 50 μm
Width: 1000mm
Length: 1000m
Refractive index: 1.540
2.2.2 Hard coat layer (D)
Material: Toyo Ink Co., Ltd. TYZ series, Processing device: Slot die coater with UV irradiation device)
Thickness: 2μm (both sides)
2.2.3 Underlayer (F)
Material: SiO _x
Thickness: 30nm
Formation method: DC magnetron sputtering apparatus, oxygen-introduced reactive sputtering 2.2.4 Light-transmissive conductive layer (B)
Material: ITO (Sn7wt%)
Thickness: 20nm
Formation method: DC magnetron sputtering apparatus, oxygen-introduced reactive sputtering 2.2.5 Adhesive layer (C)
A light-transmitting conductive film obtained by sequentially laminating a hard coat layer (D), a base layer (F) and a light-transmitting conductive layer (B) on the light-transmitting support layer (A) Divided into books. These were laminated by a solvent-type dry laminating method. The thickness of the adhesive layer (C) was set to 2 μm. As the material for the adhesive layer, the same material as in Example 1 was used. A solvent type dry laminator with a direct gravure head was used as a processing apparatus. The refractive index of the adhesive layer (C) was 1.560.

2.2.6 Curing The test was performed at 50 ° C. for 72 hours.

  The evaluation results are shown in Table 1. In addition, each evaluation produced 5 samples of the double-sided conductive film of this invention as mentioned above, and performed each about these 5 samples.

2.3 Example 3
A double-sided conductive film of the present invention was obtained in the same manner as in Example 1 except that the conditions were as follows.

  The light transmissive conductive layer (B) was laminated on the light transmissive support layer (A) to obtain two light transmissive conductive films, and these were laminated by a solvent-type dry laminating method.

2.3.1 Light transmissive support layer (A)
Material: Polyethylene terephthalate film Thickness: 75μm
Width: 1000mm
Length: 1000m

2.3.2 Adhesive layer (C)
The light transmissive conductive film obtained by laminating the light transmissive conductive layer (B) on the light transmissive support layer (A) was divided into 500 m 2 pieces. These were laminated by a solvent-type dry laminating method. A urethane-based dry laminate adhesive (“TM-K51” manufactured by Toyo Morton Co., Ltd.) and a curing agent “CAT-RT85” were mixed at a mass ratio of 100: 15, and this was further mixed with ethyl acetate to a solid content of 20% by weight. After being diluted with the solvent-type dry laminator with a direct gravure head and applied to one surface of each of the two light transmissive conductive films, the surfaces were bonded to each other. The thickness of the adhesive layer (C) between the two light transmissive conductive films was 3.0 μm, and the refractive index was 1.555.

  Curing was performed at 50 ° C. for 120 hours.

2.4 Example 4
Both surfaces on which the metal layer (E) is disposed by coating the surface of the light transmissive conductive layer (B) of the double-sided conductive film prepared in Example 1 with a thickness of 150 nm using a DC magnetron sputtering apparatus. A conductive film was obtained.

  The adhesion between the metal layer (E) and the light-transmitting conductive layer (B) was evaluated according to the method described in JIS K5400.

  The evaluation results are shown in Table 2. In addition, each evaluation produced 5 samples of the double-sided conductive film of this invention as mentioned above, and performed each about these 5 samples.

3.1 Comparative Example 1
A double-sided conductive film was obtained in the same manner as Example 1 except that the conditions were as follows.

3.1.1 Adhesive layer (C)
A highly transparent adhesive tape (3M product number 8146-1; thickness of about 25 μm; refractive index 1.480; elastic modulus (reference value) 1.0 MPa) was used.

3.1.2 Curing 24 hours at room temperature.

  The evaluation results are shown in Table 1. In addition, each evaluation produced 5 double-sided conductive films as mentioned above, and performed each about these 5 samples.

3.2 Comparative Example 2
A double-sided conductive film was obtained in the same manner as in Example 2 except that the conditions were as follows.

3.2.1 Light transmissive conductive layer (B)
Same as Example 1.

3.2.2 Adhesive layer (C)
A highly transparent adhesive tape (Lintech Co., Ltd., product number TL-410S-02; thickness of about 12 μm; refractive index 1.490; elastic modulus (reference value) 2.2 MPa) was used.

3.2.3 Curing 48 hours at room temperature.

  The evaluation results are shown in Table 1. In addition, each evaluation produced 5 double-sided conductive films as mentioned above, and performed each about these 5 samples.

3.3 Comparative Example 3
A double-sided conductive film was obtained in the same manner as Example 1 except that the conditions were as follows.

3.3.1 Light transmissive support layer (A)
The same as Comparative Example 1.

3.3.2 Underlayer (F)
The same as Comparative Example 1.

3.3.3 Light transmissive conductive layer (B)
The same as Comparative Example 1.

3.3.4 Adhesive layer (C)
The same as Comparative Example 1.

3.3.5 Curing It was the same as Comparative Example 1.

3.3.6 Metalworking Same as Example 4.

  The evaluation results are shown in Table 2. In addition, each evaluation produced 5 double-sided conductive films as mentioned above, and performed each about these 5 samples.

1 Double-sided conductive film 11 Light-transmissive conductive film 111 Light-transmissive support layer (A)
112 Light transmissive conductive layer (B)
113 Hard coat layer (D)
12 Adhesive layer (C)

Claims (8)

Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A double-sided conductive film adjacent through layers,
The double-sided conductive film, wherein the adhesive layer (C) is formed from a reactive curable adhesive. The double-sided conductive film according to claim 1, which can be obtained by bonding the two light-transmitting conductive films to each other by a dry laminating method using the reaction curable adhesive. The double-sided conductive film according to claim 1 or 2, wherein the adhesive layer (C) has a thickness of 1 to 10 µm. further,
(D) It contains a hard coat layer, and the hard coat layer (D) is disposed between the light transmissive support layer (A) and the light transmissive conductive layer (B). 4. The double-sided conductive film according to any one of 3 above. On at least one side,
(E) The double-sided conductive film according to any one of claims 1 to 4, wherein a metal layer is disposed. A film roll formed by winding a double-sided conductive film having a width of 0.2 to 2 m and a length of 10 to 1000 m, and satisfying the following requirements (I) and (II):
(I) The double-sided conductive film is
Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A double-sided conductive film adjacent through layers,
The adhesive layer (C) is formed from a reactive curable adhesive; and (II) obtained by measuring at any 25 points arranged in a 5 × 5 square lattice at 25 mm intervals in the film roll. The film thickness satisfies the following formula (1).
(T _max −t _min ) / (t _ave ) × 100 <2.0 (1)
(In the above, t _max , t _min, and t _ave are the maximum value, minimum value, and average value of the film thickness obtained by measurement at the 25 points, respectively) A touch panel comprising the double-sided conductive film according to claim 1. Each,
(A) Light transmissive support layer; and (B) Light transmissive support layer (A) side surfaces of two light transmissive conductive films containing the light transmissive conductive layer are mutually (C) adhesive. A method for producing a double-sided conductive film adjacent through a layer,
A method comprising a step of bonding the two light-transmitting conductive films to each other by a dry laminating method using a reaction curable adhesive.

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