JP2022169608A - Transparent conductive film laminate and method for producing transparent conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film laminated body and an efficient manufacturing method of a transparent conductive film.

SOLUTION: A transparent conductive film laminated body 1 includes a protective resin film 4, an adhesive layer 5, and a transparent conductive film 3, in this order. The transparent conductive film 3 includes a transparent resin substrate 6 and a transparent conductive layer 9, in this order. At least one of the protective resin film 4 and the transparent resin substrate 6 contains cycloolefin resin and satisfies the following expressions (1) and (2): Y<0.0003X^2.7 (1), 0.2≤Y<6.0 (2) (X is a thickness (μm) of a protective resin film 4 or a transparent resin substrate 6 containing cycloolefin resin. Provided that both protective resin film 4 and transparent resin substrate 6 contain cycloolefin resin, X indicates a value of a thinner one. Y is a peeling force (N/50 mm) of the adhesive layer under the condition of a tensile speed of 10 m/min and a peeling angle of 180 degrees).

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a transparent conductive film laminate and a method for producing a transparent conductive film.

2. Description of the Related Art Conventionally, it is known that an image display device having a touch panel includes a touch panel film in which a transparent wiring layer made of indium-tin composite oxide (ITO) is arranged on a transparent substrate. It is known that a touch panel film crystallizes an ITO layer by heating or the like in order to reduce its surface resistance value. In addition, in order to prevent the occurrence of scratches during transportation and crystallization, the touch panel film should be coated with a protective film on one side thereof with an adhesive before transportation, and the protective film should be peeled off after crystallization. is also known (see, for example, Patent Document 1).

By the way, in recent years, in the capacitive method in which a polarizing plate is combined with a touch panel film, in order to prevent depolarization between the polarizing plate and the touch panel film, the transparent base material of the touch panel film has substantially zero phase difference. A zero retardation film is used. A typical example of such a zero-retardation film is a cycloolefin-based resin substrate.

JP 2003-205567 A

However, this cycloolefin-based resin base material is more fragile than a transparent base material such as a polyester-based resin base material, and is easily broken. For this reason, in the step of peeling the protective film from the touch panel film after the ITO is crystallized, if the protective film is peeled off at high speed, the cycloolefin resin base material will be damaged. As a result, efficient production of the touch panel film becomes difficult.

On the other hand, if the adhesive strength of the adhesive is weakened to facilitate peeling in order to avoid damage to the cycloolefin resin substrate, air bubbles or the like are generated in the adhesive layer during the crystallization (heating) step. As a result, the surface of the touch panel film may be lifted or the thickness may be uneven. As a result, a burden is imposed on the winding device in a post-process such as a winding process.

In addition, if the adhesive force of the adhesive is increased, it is necessary to increase the stress applied for peeling, which causes an excessive burden on the peeling device.

An object of the present invention is to provide a transparent conductive film laminate and a method for producing a transparent conductive film that can efficiently produce a transparent conductive film.

The present invention [1] comprises a protective resin film, an adhesive layer and a transparent conductive film in this order, the transparent conductive film comprises a transparent resin substrate and a transparent conductive layer in this order, the protective resin film and the At least one of the transparent resin substrates contains a transparent conductive film laminate containing a cycloolefin resin and satisfying the following formulas (1) and (2).

Y < 0.0003X ^2.7 (1)
0.2≦Y<6.0 (2)
(In the formula, X represents the thickness (μm) of the protective resin film or the transparent resin substrate containing the cycloolefin resin. However, both the protective resin film and the transparent resin substrate When a cycloolefin resin is contained, the thinner value is indicated Y indicates the peel strength (N/50 mm) of the pressure-sensitive adhesive layer under the conditions of a tensile speed of 10 m/min and a peel angle of 180°. )
The present invention [2] includes the transparent conductive film laminate according to [1], wherein the transparent resin substrate contains a cycloolefin resin.

The present invention [3] includes the transparent conductive film laminate according to [1] or [2], wherein the protective resin film contains a cycloolefin-based resin or a polyester-based resin.

The present invention [4] provides the transparent conductive film laminate according to any one of [1] to [3], wherein the protective resin film and the transparent resin substrate each have a thickness of 100 μm or less. contains.

In the present invention [5], the transparent conductive film comprises a second cured resin layer, the transparent resin substrate, the first cured resin layer, an optical adjustment layer and the transparent conductive layer in this order, [1] to [ 4].

The present invention [6] includes the transparent conductive film laminate according to any one of [1] to [5], wherein the transparent conductive layer contains an indium-tin composite oxide.

The present invention [7] comprises a step of preparing a transparent conductive film comprising a transparent resin substrate and a transparent conductive layer in this order, and a protective member comprising a protective resin film and an adhesive layer in this order, the transparent conductive affixing the film and the protective member so that the pressure-sensitive adhesive layer is in contact with the transparent resin substrate side of the transparent conductive film to obtain a transparent conductive film laminate; A heating step of heating the conductive film laminate to crystallize the transparent conductive layer, and a peeling step of peeling the protective member from the transparent conductive film after the heating step, wherein the protective resin film and At least one of the transparent resin substrates contains a cycloolefin-based resin, and includes a method for producing a transparent conductive film that satisfies the following formulas (1) and (2) after the heating step.

Y < 0.0003X ^2.7 (1)
0.2≦Y<6 (2)
(In the formula, X represents the thickness (μm) of the protective resin film or the transparent resin substrate containing the cycloolefin resin. However, both the protective resin film and the transparent resin substrate When a cycloolefin resin is contained, the thinner value is indicated Y indicates the peel strength (N/50 mm) of the pressure-sensitive adhesive layer under the conditions of a tensile speed of 10 m/min and a peel angle of 180°. )
The present invention [8] is the transparent conductive film according to [7], further comprising an optical inspection step of optically inspecting the transparent conductive film laminate after the heating step and before the peeling step. including the manufacturing method of

According to the transparent conductive film laminate of the present invention, the thickness X (μm) of the protective resin film or transparent resin substrate containing the cycloolefin resin and the peeling force Y (N/50 mm) of the adhesive layer under predetermined conditions ) satisfies the relationship Y<0.0003X ^2.7 . Therefore, the stress required for peeling the pressure-sensitive adhesive layer and the transparent resin substrate can be sufficiently reduced, and the burden on the protective resin film or the transparent resin substrate can be reduced. As a result, damage to the protective resin film or the transparent resin substrate can be suppressed when the protective resin film is peeled off from the transparent conductive film at high speed.

Moreover, according to the transparent conductive film laminate of the present invention, the relationship of 0.2≦Y is satisfied. Therefore, the protective resin film and the transparent resin substrate are sufficiently adhered via the adhesive layer, and the generation of air bubbles in the adhesive layer can be suppressed in the heating step. Therefore, it is possible to suppress the occurrence of floating and thickness unevenness on the surface of the transparent conductive film laminate. As a result, it is possible to reduce the burden on the winding device in the subsequent process such as the winding process. In addition, the transparent conductive film laminate can be inspected with high accuracy in the subsequent optical inspection process or the like.

Moreover, according to the transparent conductive film laminate of the present invention, the relationship Y<6.0 is satisfied. Therefore, the stress applied to the peeling can be reduced, and the peeling can be smoothly carried out without burdening the conventional peeling device.

From these, the transparent conductive film laminate of the present invention can produce a transparent conductive film at high speed while suppressing the burden on the apparatus, so that the transparent conductive film can be produced efficiently.

Moreover, since the transparent conductive film laminate of the present invention is used in the method for producing the transparent conductive film of the present invention, the transparent conductive film can be produced efficiently.

FIG. 1 is a cross-sectional view showing a first embodiment of the transparent conductive film laminate of the present invention. 2A to 2E are process cross-sectional views showing the first embodiment of the method for producing a transparent conductive film of the present invention, in which FIG. 2A is a preparation process, FIG. A heating step, FIG. 2D shows a peeling step, and FIG. 2E shows a step of obtaining a crystallized transparent conductive film. FIG. 3 shows a conceptual diagram of the peel force measuring method in the example. FIG. 4 shows a graph showing the relationship between the peel strength and the thickness of the cycloolefin resin base material in Examples.

<First Embodiment>
1st Embodiment of the transparent conductive film laminated body of this invention is described below, referring a figure. In FIG. 1, the vertical direction of the paper is the vertical direction (thickness direction, first direction), the upper side of the paper is the upper side (one side in the thickness direction, the one side of the first direction), and the lower side of the paper is the lower side (thickness direction). the other side, the other side in the first direction). Moreover, the left-right direction and the depth direction on the paper surface are plane directions orthogonal to the up-down direction. Specifically, it conforms to the directional arrows in each figure.

1. Transparent Conductive Film Laminate A transparent conductive film laminate 1 (hereinafter also referred to as film laminate 1) has a film shape (including a sheet shape) having a predetermined thickness, and is oriented in a predetermined direction perpendicular to the thickness direction (surface direction) and has a flat upper surface and a flat lower surface. The film laminate 1 is, for example, one component for producing a base material for a touch panel provided in an image display device, and is not an image display device. That is, the film laminate 1 is a device that does not include an image display element such as an LCD module, is distributed as a component alone, and can be used industrially.

Specifically, as shown in FIG. 1 , the film laminate 1 includes a protective member 2 and a transparent conductive film 3 . Preferably, film laminate 1 comprises protective member 2 and transparent conductive film 3 .

2. Protective Member The protective member 2 is provided on the lower surface (thickness It is a film provided on the surface on the other side of the direction). The protective member 2 supports the transparent conductive film 3 from below.

The protective member 2 includes a protective resin film 4 and an adhesive layer 5 disposed on its upper surface (surface on one side in the thickness direction). That is, the protective member 2 includes the protective resin film 4 and the adhesive layer 5 in this order. Preferably, the protective member 2 consists of the protective resin film 4 and the adhesive layer 5 only.

(protective resin film)
The protective resin film 4 is a base material that secures the mechanical strength of the protective member 2 and protects the transparent conductive film 3 from scratches that may occur during transportation, heating, and/or storage.

The protective resin film 4 contains a cycloolefin resin and is formed in a film shape (including a sheet shape). Specifically, the protective resin film 4 is a cycloolefin-based resin substrate made of a cycloolefin-based resin. This makes it possible to use the same type of resin as the transparent resin substrate 6, which will be described later, and suppress the occurrence of curling of the film laminate 1 due to heating.

A cycloolefin-based resin is obtained by polymerizing a cycloolefin monomer and is a polymer having an alicyclic structure in its main chain. Cycloolefin resins include cycloolefin polymers (COP) composed of cycloolefin monomers, and cycloolefin copolymers (COC) composed of copolymers of cycloolefin monomers and olefins such as ethylene.

Cycloolefin monomers include polycyclic olefins such as norbornene, methylnorbornene, dimethylnorbornene, ethylidenenorbornene, butylnorbornene, dicyclopentadiene, dihydrodicyclopentadiene, tetracyclododecene, and tricyclopentadiene; monocyclic olefins such as cyclopentene, cyclooctadiene and cyclooctatriene; These cycloolefins can be used alone or in combination of two or more.

The thickness of the protective resin film 4 is, for example, 150 μm or less, preferably 100 μm or less, more preferably 50 μm or less, and for example, 5 μm or more, preferably 15 μm or more. By setting the thickness of the protective resin film 4 within the above range, in the step of peeling the protective member 2 from the film laminate 1, the protective resin film 4 and the transparent resin substrate 6 are prevented from being damaged while enabling high-speed and smooth peeling. can be suppressed. The thickness of the protective resin film 4 can be measured using, for example, a microgauge thickness meter.

(Adhesive layer)
The pressure-sensitive adhesive layer 5 is a layer (pressure-sensitive adhesive layer) for adhering the protective resin film 4 to the transparent conductive film 3, and after adhering, the adhesive layer 5 is attached to the transparent conductive film 3. It is a layer that can be easily peeled off (easy peeling layer).

The adhesive layer 5 has a film shape, and is arranged, for example, on the entire upper surface of the protective resin film 4 so as to be in contact with the upper surface of the protective resin film 4 . More specifically, the pressure-sensitive adhesive layer 5 is provided between the protective resin film 4 and the transparent conductive film 3 (particularly, the transparent resin substrate 6) between the upper surface of the protective resin film 4 and the lower surface of the transparent conductive film 3. is arranged so as to contact the Specifically, the adhesive layer 5 is pressure-sensitively adhered to the lower surface of the second cured resin layer 7b (which will be described later, the side surface of the transparent resin substrate 6 in the transparent conductive film 3).

The adhesive layer 5 is formed from an adhesive composition.

Examples of adhesive compositions include acrylic adhesive compositions, rubber adhesive compositions, silicone adhesive compositions, polyester adhesive compositions, polyurethane adhesive compositions, and polyamide adhesive compositions. , epoxy-based adhesive compositions, vinyl alkyl ether-based adhesive compositions, fluorine-based adhesive compositions, and the like. These adhesive compositions can be used alone or in combination of two or more.

As the adhesive composition, an acrylic adhesive composition is preferably used from the viewpoint of adhesiveness, releasability, suppression of air bubbles during heating, and the like.

The acrylic pressure-sensitive adhesive composition contains, for example, a (meth)acrylic acid alkyl ester as a main component and an acrylic polymer obtained by copolymerizing a monomer component containing a functional group-containing monomer as a copolymer component. contained as an ingredient.

(Meth)acrylic acid alkyl ester is acrylic acid alkyl ester and/or methacrylic acid alkyl ester, specifically, for example, butyl (meth)acrylate, isobutyl (meth)acrylate, sec (meth)acrylate -butyl, t-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, (meth) ) octyl acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate and linear or branched (meth)acrylic acid alkyl esters having an alkyl moiety having 4 to 14 carbon atoms, such as tetradecyl (meth)acrylate. The (meth)acrylic acid alkyl esters may be used alone or in combination of two or more.

The (meth)acrylic acid alkyl ester preferably includes a (meth)acrylic acid alkyl ester having an alkyl moiety having 4 to 10 carbon atoms, and more preferably 2-ethylhexyl (meth)acrylate.

The mixing ratio of the (meth)acrylic acid alkyl ester is, for example, 90 parts by mass or more, preferably 95 parts by mass or more, more preferably 97 parts by mass or more with respect to the total amount of 100 parts by mass of the monomer components, and , for example, 99.5 parts by mass or less, preferably 99 parts by mass or less. The release force of the pressure-sensitive adhesive layer 5 can be adjusted by adjusting the blending ratio of the (meth)acrylic acid alkyl ester.

Examples of functional group-containing monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, monomethyl itaconate, 2-(meth)acryloyloxyethyl trimellitate, and carboxyethyl (meth)acrylate. , and hydroxyl group-containing monomers such as 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate. The functional group-containing monomers can be used singly or in combination of two or more.

The functional group-containing monomer is preferably a hydroxyl group-containing monomer, more preferably 2-hydroxyethyl acrylate, from the viewpoints of adhesiveness, peelability, suppression of air bubbles during heating, and the like.

The blending ratio of the functional group-containing monomer is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass, per 100 parts by mass of the total amount of the monomer components. Part by mass or less.

The weight-average molecular weight of the acrylic polymer is, for example, 100,000 or more, preferably 300,000 or more, more preferably 650,000 or more, from the viewpoint of adhesiveness, peelability, bubble suppression during heating, and the like. Yes, and for example, 2,000,000 or less, preferably 1,500,000 or less. The weight average molecular weight is measured by gel permeation chromatography based on standard polystyrene conversion values.

The acrylic pressure-sensitive adhesive composition can be obtained, for example, by known methods such as solution polymerization, bulk polymerization, and photopolymerization.

The pressure-sensitive adhesive composition can also appropriately contain known additives such as cross-linking agents, tackifier resins, processing aids, pigments, flame retardants, fillers, softeners, anti-aging agents, and the like.

Examples of cross-linking agents include epoxy-based cross-linking agents, isocyanate-based cross-linking agents, melamine-based resins, aziridine derivatives, and metal chelate compounds. A crosslinking agent can be used individually or in combination of 2 or more types. The cross-linking agent preferably includes an isocyanate-based cross-linking agent.

The ratio of the cross-linking agent is, for example, 0.1 parts by mass or more, preferably 1 part by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass or less, with respect to 100 parts by mass of the acrylic polymer. is. By adjusting the mixing ratio of the cross-linking agent, the peel strength of the pressure-sensitive adhesive layer 5 can be adjusted.

The thickness of the adhesive layer 5 is, for example, 5 μm or more, preferably 10 μm or more, and is, for example, 30 μm or less, preferably 20 μm or less.

The thickness of the protective member 2 is, for example, 10 μm or more, preferably 25 μm or more, more preferably 40 μm or more, and is, for example, 150 μm or less, preferably 100 μm or less, more preferably 50 μm or less.

3. Transparent Conductive Film The transparent conductive film 3 has a film shape with a predetermined thickness, extends in the plane direction, and has a flat upper surface and a flat lower surface. The transparent conductive film 3 is, for example, one component such as a base material for a touch panel provided in an image display device, that is, it is not an image display device. That is, the transparent conductive film 3 is a component for producing an image display device or the like, does not include an image display element such as an LCD module, is distributed as a component alone, and is a device that can be used industrially.

Specifically, as shown in FIG. 1, the transparent conductive film 3 includes a transparent resin substrate 6, a cured resin layer 7, an optical adjustment layer 8, and a transparent conductive layer 9 in this order. More specifically, the transparent conductive film 3 includes a transparent resin substrate 6, a first cured resin layer 7a disposed on the upper surface (one surface) of the transparent resin substrate 6, and a first cured resin layer 7a. The optical adjustment layer 8 arranged on the upper surface, the transparent conductive layer 9 arranged on the upper surface of the optical adjustment layer 8, and the second cured resin layer 7b arranged on the lower surface (the other surface) of the transparent resin base material 6 Prepare. That is, the transparent conductive film 3 includes a second cured resin layer 7b, a transparent resin substrate 6, a first cured resin layer 7a, an optical adjustment layer 8, and a transparent conductive layer 9 in order from the bottom. Preferably, the transparent conductive film 3 comprises a transparent resin substrate 6 , a cured resin layer 7 , an optical adjustment layer 8 and a transparent conductive layer 9 .

(Transparent resin substrate)
The transparent resin base material 6 is a transparent base material for ensuring the mechanical strength of the transparent conductive film 3 . That is, the transparent resin base material 6 supports the transparent conductive layer 9 together with the cured resin layer 7 and the optical adjustment layer 8 .

The transparent resin substrate 6 has a film shape, and is arranged, for example, on the entire upper surface of the protective member 2 (particularly, the pressure-sensitive adhesive layer 5) so as to be in contact with the upper surface of the protective member 2. More specifically, the transparent resin substrate 6 is placed between the adhesive layer 5 and the first cured resin layer 7a so as to be in contact with the upper surface of the adhesive layer 5 and the lower surface of the first cured resin layer 7a. are placed.

The transparent resin substrate 6 is, for example, a polymer film having transparency. The transparent resin substrate 6 contains a cycloolefin resin. Preferably, the transparent resin substrate 6 is a cycloolefin-based resin substrate made of a cycloolefin-based resin. Thereby, a low in-plane retardation and good transparency can be imparted to the transparent resin substrate 6 . Further, if the transparent resin substrate 6 contains a cycloolefin resin, the coefficient of thermal expansion of the transparent resin substrate 6 and the coefficient of thermal expansion of the protective resin film 4 can be matched. 2C), deformation (such as warpage) of the transparent resin substrate 6 can be suppressed. Furthermore, by matching the phase difference of the transparent resin base material 6 and the phase difference of the protective resin film 4, the optical inspection process, which will be described later, can be carried out with high accuracy.

The total light transmittance (JIS K 7375-2008) of the transparent resin substrate 6 is, for example, 80% or more, preferably 85% or more.

The in-plane birefringence of the transparent resin substrate 6 is, for example, 10 nm or less, preferably 5 nm or less. The in-plane birefringence can be measured by, for example, a birefringence measurement system (manufactured by Axometrics, trade name “Axoscan”).

The thickness of the transparent resin substrate 6 is, for example, 100 μm or less, preferably 50 μm or less, and is, for example, 5 μm or more, preferably 15 μm or more. By setting the thickness of the transparent resin substrate 6 within the above range, in the step of peeling the protective member 2 from the film laminate 1, the protective resin film 4 and the transparent resin substrate 6 can be smoothly peeled off at high speed. Damage can be suppressed. The thickness of the transparent resin substrate 6 can be measured using, for example, a microgauge thickness meter.

(First cured resin layer)
The first cured resin layer 7a is a scratch protection layer (first hard coat layer) for making it difficult for the transparent conductive film 3 to be scratched.

The first cured resin layer 7 a has a film shape, and is arranged, for example, on the entire upper surface of the transparent resin substrate 6 so as to be in contact with the upper surface of the transparent resin substrate 6 . More specifically, the first cured resin layer 7a is arranged between the transparent resin substrate 6 and the optical adjustment layer 8 so as to be in contact with the upper surface of the transparent resin substrate 6 and the lower surface of the optical adjustment layer 8. It is

The first cured resin layer 7a is made of, for example, a hard coat composition.

The hard coat composition of the first cured resin layer 7a contains resin, and preferably consists of only resin.

Examples of resins include curable resins and thermoplastic resins (eg, polyolefin resins), and preferably curable resins.

Examples of curable resins include active energy ray-curable resins that are cured by irradiation with active energy rays (specifically, ultraviolet rays, electron beams, etc.), and thermosetting resins that are cured by heating. Active energy ray-curable resins are preferred.

Active energy ray-curable resins include, for example, polymers having functional groups having polymerizable carbon-carbon double bonds in the molecule. Such functional groups include, for example, vinyl groups, (meth)acryloyl groups (methacryloyl groups and/or acryloyl groups), and the like.

Specific examples of active energy ray-curable resins include (meth)acrylic UV-curable resins such as urethane acrylate and epoxy acrylate.

Examples of curable resins other than active energy ray-curable resins include thermosetting resins such as urethane resins, melamine resins, alkyd resins, siloxane-based polymers, and organic silane condensates.

These resins can be used singly or in combination of two or more.

This hard coat composition can also contain particles described later in the second cured resin layer 7b.

The thickness of the first cured resin layer 7a is, for example, 0.1 μm or more, preferably 0.5 μm or more, and for example, 10 μm or less, preferably, from the viewpoint of scratch resistance and visibility suppression of the wiring pattern. 5 μm or less. The thickness of the cured resin layer 7 can be measured with, for example, a spectroscopic ellipsometer.

(Optical adjustment layer)
The optical adjustment layer 8 suppresses the visibility of the wiring pattern in the transparent conductive layer 9 and ensures excellent transparency of the transparent conductive film 3. It is the layer that adjusts the

The optical adjustment layer 8 has a film shape, and is arranged, for example, on the entire upper surface of the first cured resin layer 7a so as to be in contact with the upper surface of the first cured resin layer 7a. More specifically, the optical adjustment layer 8 is arranged between the first cured resin layer 7a and the transparent conductive layer 9 so as to be in contact with the upper surface of the first cured resin layer 7a and the lower surface of the transparent conductive layer 9. It is

The optical adjustment layer 8 is a layer formed from a composition for an optical adjustment layer.

The optical adjustment layer composition contains, for example, a resin. The optical adjustment layer composition preferably contains a resin and particles, and more preferably consists of a resin and particles only.

Although the resin is not particularly limited, the same resin as used in the hard coat composition can be used. These resins can be used singly or in combination of two or more. A curable resin is preferred, and an active energy ray curable resin is more preferred.

The content of the resin is, for example, 10% by mass or more, preferably 25% by mass or more, and for example, 95% by mass or less, preferably 60% by mass or less, relative to the composition for the optical adjustment layer. be.

As the particles, a suitable material can be selected according to the refractive index required for the optical adjustment layer 8, and examples thereof include inorganic particles and organic particles. Examples of inorganic particles include silica particles, metal oxide particles made of zirconium oxide, titanium oxide, zinc oxide, oxides, and carbonate particles such as calcium carbonate. Examples of organic particles include crosslinked acrylic resin particles. The particles can be used singly or in combination of two or more.

The particles preferably include inorganic particles, more preferably metal oxide particles, and still more preferably zirconium oxide particles (ZnO ₂ ).

The average particle diameter (median diameter) of the particles is, for example, 10 nm or more, preferably 20 nm or more, and is, for example, 100 nm or less, preferably 50 nm or less.

The content of the particles is, for example, 5% by mass or more, preferably 40% by mass or more, and for example, 90% by mass or less, preferably 75% by mass or less, relative to the composition for the optical adjustment layer. be.

The refractive index of the optical adjustment layer 8 is, for example, 1.50 or more, preferably 1.60 or more, and is, for example, 1.80 or less, preferably 1.75 or less. The refractive index can be measured, for example, with an Abbe refractometer.

The thickness of the optical adjustment layer 8 is, for example, 50 nm or more, preferably 100 nm or more, and is, for example, 800 nm or less, preferably 300 nm or less. The thickness of the optical adjustment layer 8 can be measured by, for example, a spectroscopic ellipsometer.

(Transparent conductive layer)
The transparent conductive layer 9 is a conductive layer for forming a wiring pattern in a post-process such as etching.

The transparent conductive layer 9 is the uppermost layer of the transparent conductive film 3 and has a film shape. there is
The transparent conductive layer 9 is positioned above the transparent resin substrate 6 .

At least one selected from the group consisting of In, Sn, Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, and W as the material of the transparent conductive layer 9, for example. metal oxides containing metals of The metal oxide may be further doped with a metal atom shown in the above group, if necessary.

The material of the transparent conductive layer 9 is preferably an indium-containing oxide such as indium-tin composite oxide (ITO), an antimony-containing oxide such as antimony-tin composite oxide (ATO), and the like. Indium-containing oxides are preferred, and ITO is more preferred. If the material of the transparent conductive layer 9 is ITO, the transparent conductive layer 9 can achieve both excellent transparency and excellent conductivity.

When ITO is used as the material of the transparent conductive layer 9, the tin oxide (SnO ₂ ) content is preferably, for example, 0.5% by mass or more with respect to the total amount of tin oxide and indium oxide (In ₂ O ₃ ). is 3% by mass or more, and is, for example, 15% by mass or less, preferably 13% by mass or less.

"ITO" may be a composite oxide containing at least indium (In) and tin (Sn), and may contain additional components other than these. Examples of additional components include metal elements other than In and Sn, and specific examples include Zn, Ga, Sb, Ti, Si, Zr, Mg, Al, Au, Ag, Cu, Pd, W, and Fe. , Pb, Ni, Nb, Cr, Ga, and the like.

The thickness of the transparent conductive layer 9 is, for example, 10 nm or more, preferably 20 nm or more, and is, for example, 100 nm or less, preferably 35 nm or less. The thickness of the transparent conductive layer 9 can be measured by, for example, a spectroscopic ellipsometer.

Transparent conductive layer 9 may be either crystalline or amorphous. The transparent conductive layer 9 is preferably crystalline, more specifically, a crystalline ITO layer. Thereby, the transparency of the transparent conductive layer 9 can be improved, and the specific resistance value of the transparent conductive layer 9 can be further reduced.

The transparent conductive film 3 including the amorphous transparent conductive layer 9 (amorphous transparent conductive layer 9a) is referred to as an amorphous transparent conductive film 3a. Further, the transparent conductive film 3 obtained by crystallizing the amorphous transparent conductive layer 9a and provided with the crystalline transparent conductive layer 9 (crystallized transparent conductive layer 9b) is referred to as the crystallized transparent conductive film 3b. called.

The fact that the transparent conductive layer 9 is crystalline means that, for example, when the transparent conductive layer 9 is an ITO layer, it is immersed in hydrochloric acid (concentration: 5% by mass) at 20° C. for 15 minutes, then washed with water and dried to obtain a thickness of about 15 mm. It can be judged by measuring the resistance between the terminals. The ITO layer is defined as crystalline when the resistance between terminals for 15 mm is 10 kΩ or less after immersion in hydrochloric acid (20° C., concentration: 5% by mass), washing with water, and drying.

(Second cured resin layer)
The second cured resin layer 7b is a scratch protection layer (second hard coat layer) for making it difficult for the transparent conductive film 3 to be scratched. In addition, the second cured resin layer 7b is an anti-blocking layer for imparting blocking resistance to the surfaces of the plurality of transparent conductive films 3 in contact with each other when, for example, the plurality of film laminates 1 are laminated in the thickness direction. But also.

The second cured resin layer 7 b is arranged on the entire lower surface of the transparent resin base material 6 so as to be in contact with the lower surface of the transparent resin base material 6 .

The second cured resin layer 7b is a layer similar to the first cured resin layer 7a, and includes, for example, the same layers as those described above for the first cured resin layer 7a.

Preferably, the hard coat composition of the second cured resin layer 7b contains resin and particles, preferably consists of resin and particles only.

Examples of the resin include those similar to those of the hard coat composition described above.

Examples of particles include inorganic particles and organic particles. Examples of inorganic particles include silica particles, metal oxide particles such as zirconium oxide, titanium oxide, zinc oxide and tin oxide, and carbonate particles such as calcium carbonate. Examples of organic particles include crosslinked acrylic resin particles. The particles can be used singly or in combination of two or more.

From the viewpoint of transparency, the particles are preferably organic particles, more preferably crosslinked acrylic resin particles.

The mode particle diameter of the particles is, for example, 0.8 µm or more, preferably 1.0 µm or more, and for example, 20 µm or less, preferably 10 µm, from the viewpoint of antiblocking properties, scratch resistance, and transparency. It is below. The mode particle size is the particle size that indicates the maximum value of the particle distribution. ethyl, measurement mode: HPF measurement, measurement method: total count). A measurement sample is prepared by diluting the particles with ethyl acetate to 1.0% by mass and dispersing them uniformly using an ultrasonic cleaner.

The content of the particles is, for example, 0.01 parts by mass or more, preferably 0.1 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass, with respect to 100 parts by mass of the resin. It is below.

The thickness of the second cured resin layer 7b is, for example, 0.1 μm or more, preferably 0.5 μm or more, and for example, 10 μm or less, preferably, from the viewpoint of scratch resistance and visibility suppression of the wiring pattern. 5 μm or less.

3. Method for Producing Crystallized Transparent Conductive Film As a first embodiment of the method for producing a transparent conductive film of the present invention, a method for producing a crystallized transparent conductive film 3b will be described with reference to FIGS. 2A to 2E.

The method for manufacturing the crystallized transparent conductive film 3b includes, for example, a preparation step of preparing the amorphous transparent conductive film 3a and the protective member 2, and a bonding step of adhering the amorphous transparent conductive film 3a and the protective member 2. A heating step of heating the amorphous transparent conductive film laminate 1a, and a peeling step of peeling the protective member 2 are provided. Further, the method for producing the crystallized transparent conductive film 3b may include, for example, an optical inspection step of optically inspecting the crystallized transparent conductive film laminate 1b (described later) after the heating step and before the peeling step. can.

In the manufacturing method of the crystallized transparent conductive film 3b, the preparing process, the attaching process, the heating process and the peeling process are carried out in this order. Preferably, the preparing step, the sticking step, the heating step, the optical inspection step and the peeling step are performed in this order.

(Preparation process)
In the preparing step, as shown in FIG. 2A, an amorphous transparent conductive film 3a and a protective member 2 are prepared.

Specifically, while manufacturing the amorphous transparent conductive film 3a, the protective member 2 is manufactured separately.

In order to manufacture the amorphous transparent conductive film 3a, first, the transparent resin substrate 6 is prepared, and then the cured resin layer 7 (the first cured resin layer 7a and the second cured resin layer 7a is applied to the transparent resin substrate 6). A resin layer 7b), an optical adjustment layer 8 and an amorphous transparent conductive layer 9a are provided. For example, a diluted solution is prepared by diluting the hard coat composition with a solvent, the diluted solution is applied to both surfaces of the transparent resin substrate 6, the diluted solution is dried, and the hard coat composition is cured to obtain a cured resin. A layer 7 is provided. Further, a diluted solution is prepared by diluting the composition for the optical adjustment layer with a solvent, the diluted solution of the composition for the optical adjustment layer is applied to the upper surface of the first cured resin layer 7a, the diluted solution is dried, and the optical adjustment layer composition is dried. The optical adjustment layer 8 is provided by curing the adjustment layer composition. Furthermore, a transparent conductive layer 9 is provided on the upper surface of the optical adjustment layer 8 by, for example, a sputtering method.

Also, at this time, each layer can be provided on the transparent resin substrate 6 by, for example, a roll-to-roll method, or a part or all of these layers can be provided by a batch method (sheet-fed method). can also As a result, an amorphous transparent conductive film 3a having the second cured resin layer 7b, the transparent resin substrate 6, the first cured resin layer 7a, the optical adjustment layer 8, and the amorphous transparent conductive layer 9a in this order is obtained. .

Separately, in order to manufacture the protective member 2, first, the protective resin film 4 is prepared.

Next, an adhesive layer 5 is provided on the top surface of the protective resin film 4 . In order to provide the adhesive layer 5, a diluted solution of the adhesive composition is prepared, the diluted solution of the adhesive composition is applied to the upper surface of the protective resin film 4, and the diluted solution is dried.

Thereby, the protective member 2 provided with the protective resin film 4 and the adhesive layer 5 in this order is obtained.

(Affixing process)
In the adhering step, as shown in FIG. 2B, the protective member 2 and the amorphous transparent conductive film 3a are adhered.

For example, the adhesive layer 5 is applied so that it contacts the second cured resin layer 7b (the second cured resin layer 7b located on the transparent resin substrate 6 side with respect to the amorphous transparent conductive layer 9a in the transparent conductive film 3). Next, the protective member 2 is adhered to the amorphous transparent conductive film 3a. That is, the protective resin film 4 is pressure-sensitively adhered to the second cured resin layer 7b with the adhesive layer 5 interposed therebetween. Specifically, the upper surface of the adhesive layer 5 is brought into contact with the lower surface of the second cured resin layer 7b.

As a result, an amorphous transparent conductive film laminate 1a including the protective resin film 4, the adhesive layer 5, and the amorphous transparent conductive film 3a in this order is obtained.

(Heating process)
In the heating step, as shown in FIG. 2C, the amorphous transparent conductive film laminate 1a is heated.

Specifically, for example, the amorphous transparent conductive film laminate 1a is heated in the atmosphere.

Heat treatment can be performed using, for example, an infrared heater, an oven, or the like.

The heating temperature is, for example, 100° C. or higher, preferably 120° C. or higher, and is, for example, 200° C. or lower, preferably 160° C. or lower.

The heating time is appropriately determined depending on the heating temperature, and is, for example, 10 minutes or longer, preferably 30 minutes or longer, and is, for example, 5 hours or shorter, preferably 3 hours or shorter.

Thereby, the amorphous transparent conductive layer 9a is crystallized to become a crystallized transparent conductive layer 9b. That is, a crystallized transparent conductive film laminate 1b including the protective resin film 4, the adhesive layer 5, and the crystallized transparent conductive film 3b in this order is obtained.

The surface resistance value of the crystallized transparent conductive layer 9b is, for example, 200Ω/□ or less, preferably 150Ω/□ or less, and is, for example, 10Ω/□ or more.

If necessary, the transparent conductive layer 9 may be formed into a wiring pattern such as stripes by a known etching method before or after the heating process.

The crystallized transparent conductive film laminate 1b satisfies the following formulas (1) and (2).

Y < 0.0003X ^2.7 (1)
0.2≦Y<6.0 (2)
X indicates the smaller value of the thickness (μm) of the protective resin film 4 and the thickness (μm) of the transparent resin substrate 6 .

Y indicates the peel strength (N/50 mm) of the pressure-sensitive adhesive layer 5 under the conditions of a tensile speed of 10 m/min and a peel angle of 180°.

Preferably, the amorphous transparent conductive film laminate 1a is heated at 100° C. to 200° C. for 10 minutes to 5 hours (more preferably, 130° C. for 90 minutes). The crystallized transparent conductive film laminate 1b satisfies the above formulas (1) and (2).

If the crystallized transparent conductive film laminate 1b does not satisfy the above formula (1), the protective resin film 4 or the transparent resin substrate 6 will be damaged in the peeling process.

Further, when the crystallized transparent conductive film laminate 1b does not satisfy the above formula (2), air bubbles are generated in the pressure-sensitive adhesive layer 5 in the heating step and float on the surface of the crystallized transparent conductive film laminate 1b. Thickness unevenness occurs. Moreover, in the peeling process, the force required for peeling increases, which places a burden on the peeling device and makes smooth peeling difficult.

In the above formula (1), the range of X (unit: μm) is, for example, 5 or more, preferably 10 or more, more preferably 15 or more, still more preferably 20 or more, most preferably 25 or more. and is, for example, 100 or less, preferably 60 or less, more preferably 50 or less, still more preferably 40 or less.

In the above formula (2), the crystallized transparent conductive film laminate 1b preferably satisfies the following formula (2').

0.2 ≤ Y ≤ 5.0 (2')
(Optical inspection process)
In the optical step, the crystallized transparent conductive film laminate 1b is optically inspected.

For example, as indicated by a phantom line, an optical inspection process is performed using an inspection device 13 having a light emitting section 14 and a light receiving section 15 . Specifically, first, the light-emitting portion 14 and the light-receiving portion 15 are arranged to face each other with a gap therebetween so as to face each other in the thickness direction. Next, the crystallized transparent conductive film laminate 1b is placed between the light emitting section 14 and the light receiving section 15. As shown in FIG. Subsequently, light is emitted from the light emitting section 14 toward the crystallized transparent conductive film laminate 1b, and the light that has passed through the crystallized transparent conductive film laminate 1b is received by the light receiving section 15 . Then, an inspection unit (not shown) connected to the light receiving unit 15 analyzes the light received by the light receiving unit 15 to perform an optical inspection process.

(Peeling process)
In the peeling step, as shown in FIG. 2D, the protective member 2 is peeled off from the crystallized transparent conductive film 3b. That is, the protective member 2 is removed from the crystallized transparent conductive film laminate 1b.

For example, by a roll-to-roll process, one end of the crystallized transparent conductive film 3b in the longitudinal direction is fixed, and the crystallized transparent conductive film 3b is separated from the upper surface of the adhesive layer 5 and the lower surface of the transparent resin substrate 6 by a roll-to-roll process. The protective member 2 is peeled off from the protective film 3b.

As a result, as shown in FIG. 2E, a crystallized transparent conductive layer comprising a second cured resin layer 7b, a transparent resin substrate 6, a first cured resin layer 7a, an optical adjustment layer 8, and a crystallized transparent conductive layer 9b in this order. A flexible film 3b is obtained.

After that, the crystallized transparent conductive film 3b is wound into a roll on a take-up roll by, for example, a roll-to-roll process.

This crystallized transparent conductive film 3b is used, for example, as a substrate for a touch panel provided in an image display device. Examples of the type of touch panel include various types such as a capacitive type and a resistive film type, and it is particularly preferably used for a capacitive type touch panel.
Specifically, there is a capacitive touch panel including a crystallized transparent conductive film 3b as a touch panel film and a polarizing plate.

4. Effect According to this method for manufacturing the crystallized transparent conductive film 3b, in the crystallized transparent conductive film laminate 1b after the heating step, the thinner one of the thicknesses of the protective resin film 4 and the transparent resin substrate 6 X (μm) and the peeling force Y (N/50 mm) of the pressure-sensitive adhesive layer 5 under high-speed peeling conditions satisfy the relationship Y<0.0003X ^2.7 (where Y<6). Therefore, the stress required for peeling the adhesive layer 5 and the transparent resin substrate 6 can be sufficiently reduced, and the burden on both the protective resin film 4 and the transparent resin substrate 6 can be reduced. . As a result, when peeling the protective resin film 4 from the crystallized transparent conductive film 3b at a high speed (for example, 10 m/min), both the protective resin film 4 and the transparent resin substrate 6 are separated from the polyester resin substrate. Even if the cycloolefin resin base material is fragile and easily broken, the breakage thereof can be suppressed.

Moreover, according to this manufacturing method, the relationship 0.2≦Y is satisfied. Therefore, the protective resin film 4 and the transparent resin substrate 6 are sufficiently adhered with the adhesive layer 5 interposed therebetween. Therefore, in the heating process, it is possible to suppress the generation of air bubbles in the pressure-sensitive adhesive layer 5, and it is possible to suppress the occurrence of floating and thickness unevenness on the surface of the crystallized transparent conductive film laminate 1b. As a result, in the post-process such as the winding process, it is possible to reduce the burden on the winding device, such as the work of adjusting winding variations due to floating. Moreover, in the subsequent optical inspection process or the like, the crystallized transparent conductive film laminate 1b can be inspected with high accuracy.

Moreover, according to this manufacturing method, the relationship Y<6.0 is satisfied. Therefore, the stress applied to the peeling can be reduced, and the peeling can be smoothly carried out without burdening the conventional peeling device.

From these, this manufacturing method can manufacture the crystallized transparent conductive film 3b at high speed while suppressing the burden on the conventional apparatus. Therefore, the crystallized transparent conductive film 3b can be produced efficiently.

In addition, according to this manufacturing method, since the generation of air bubbles in the pressure-sensitive adhesive layer is suppressed in the heating step, the transparent conductive film laminate 1 can be reliably optically inspected in the optical inspection step. As a result, the crystallized transparent conductive film 3b can be manufactured with excellent reliability.

Moreover, if the thicknesses of the protective resin film 4 and the transparent resin substrate 6 are both 100 μm or less, the stress required for peeling the adhesive layer 5 and the transparent resin substrate 6 can be further reduced. The burden on both the protective resin film 4 and the transparent resin substrate 6 can be reliably reduced. As a result, damage to the protective resin film 4 and the transparent resin substrate 6 can be suppressed while enabling smooth peeling at high speed.

<Second Embodiment and Third Embodiment>
In the second and third embodiments, the same reference numerals are given to the same members and steps as in the first embodiment, and detailed description thereof will be omitted.

In the film laminate 1 of the first embodiment, both the protective resin film 4 and the transparent resin substrate 6 contain a cycloolefin resin, but in the present invention, the protective resin film 4 and the transparent resin substrate At least one of 6 may contain a cycloolefin-based resin, and the other may contain a resin other than the cycloolefin-based resin. Examples of such a form include the second embodiment in which the protective resin film 4 is made of a resin other than a cycloolefin-based resin and the transparent resin substrate 6 contains a cycloolefin-based resin; 3rd Embodiment which consists of resin and the transparent resin base material 6 contains resin other than cycloolefin resin is mentioned.

(Second embodiment)
In the film laminate 1 of the second embodiment, the transparent resin substrate 6 contains a cycloolefin resin, but the protective resin film 4 does not contain a cycloolefin resin.

The protective resin film 4 of the second embodiment includes, for example, polyester-based resin (polyethylene terephthalate (PET), etc.), acetate-based resin, polyethersulfone-based resin, polycarbonate-based resin, polyamide-based resin, polyimide-based resin, and olefin-based resin. At least one resin selected from resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, and polyphenylene sulfide resins. be Preferably, from the viewpoint of mechanical strength and transparency, a polyester-based resin is included, and more preferably, the protective resin film 4 is a polyester-based resin substrate made of a polyester-based resin.

Polyester-based resins are polycondensates of polyvalent carboxylic acids such as dicarboxylic acids and polyalcohols such as diols. Specific examples include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

The thickness of the protective resin film 4 in the second embodiment is, for example, 150 μm or less, and is, for example, 5 μm or more, preferably 50 μm or more.

In addition, in the second embodiment, X in the above formula (1) represents the thickness (μm) of the transparent resin base material 6 .

The film laminated body 1 of 2nd Embodiment also has the same effect as 1st Embodiment.

If the transparent resin substrate 6 and the protective resin film 4 are made of the same type of resin, the first embodiment is preferred from the viewpoint of suppressing curling of the film laminate 1 due to heating.

(Third embodiment)
In the film laminate 1 of the third embodiment, the protective resin film 4 contains a cycloolefin resin, but the transparent resin substrate 6 does not contain a cycloolefin resin.

The transparent resin substrate 6 of the third embodiment includes the protective resin film 4 described in the second embodiment, preferably polyester-based resin from the viewpoint of mechanical strength and transparency, and more preferably. 3, the transparent resin base material 6 is a polyester-based resin base material made of a polyester-based resin.

In addition, in the third embodiment, X in the above formula (1) represents the thickness (μm) of the protective resin film 4 .

The film laminated body 1 of 3rd Embodiment also has the same effect as 1st Embodiment.

From the viewpoints of low in-plane retardation, good transparency, prevention of deformation due to heat, and improvement of accuracy in the optical inspection process, the first embodiment is preferred.

<Fourth Embodiment>
In the fourth embodiment, members and steps similar to those of the first to third embodiments described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the first to third embodiments, the transparent conductive layer 9 is the amorphous transparent conductive layer 9a or the crystallized transparent conductive layer 9b made of metal oxide. Nanowires or metal mesh can also be provided. The transparent conductive layer 9 preferably consists of metal nanowires or metal mesh.

A metal nanowire is a needle-like or thread-like metal with a diameter of nanometer size (preferably less than 500 nm).

The metal constituting the metal nanowires preferably includes conductive metals such as Au, Ag, Cu, and Ni, and from the viewpoint of conductivity, Au is preferable.

The metal mesh is formed by forming fine metal wires in a lattice pattern. Examples of the metal forming the metal mesh include the same metals forming the metal nanowires.

These metal nanowires or metal meshes may be plated (for example, gold-plated).

<Other Modifications>
In the modified example, the same reference numerals are given to the same members and steps as in the first to fourth embodiments described above, and detailed description thereof will be omitted.

In the first to third embodiments, the transparent conductive film 3 comprises the second cured resin layer 7b, the transparent resin substrate 6, the first cured resin layer 7a, the optical adjustment layer 8 and the transparent conductive layer 9. For example, although not shown, the transparent conductive film 3 may not include part or all of the second cured resin layer 7b, the transparent resin substrate 6, the first cured resin layer 7a, and the optical adjustment layer 8.

Preferably, the transparent conductive film 3 comprises a second cured resin layer 7b, a transparent resin substrate 6, a first cured resin layer 7a, an optical adjustment layer 8 and a transparent conductive layer 9 in this order. As a result, the transparent conductive film 3 can be provided with anti-blocking properties, scratch protection properties, and visibility suppression properties for wiring patterns.

In addition, the transparent conductive film 3 may be further provided with an optical adjustment layer 8 (second optical adjustment layer) between the second cured resin layer 7b and the transparent resin substrate 6 or the like.

Moreover, in the above-described first embodiment, as indicated by the phantom line in FIG. 2C, the method for manufacturing the crystallized transparent conductive film laminate 1b includes an optical inspection step. However, for example, it is also possible to provide only the preparing step, the attaching step, the heating step, and the peeling step without including the method for producing the crystallized transparent conductive film laminate 1b.

Preferably, the method for producing the crystallized transparent conductive film laminate 1b comprises a preparation step, a bonding step, a heating step, an optical inspection step and a peeling step in this order. In the heating shown in FIG. 2C, if air bubbles are generated in the adhesive layer 5, the crystallized transparent conductive film laminate 1b cannot be accurately inspected in the optical inspection step indicated by the phantom lines in FIG. 2C. However, in the method for producing the crystallized transparent conductive film laminate 1b, as described above, the generation of air bubbles in the pressure-sensitive adhesive layer 5 during the heating process is suppressed.

EXAMPLES Examples and comparative examples are shown below to describe the present invention more specifically. In addition, the present invention is not limited to Examples and Comparative Examples. Specific numerical values such as the mixing ratio (content ratio), physical property values, and parameters used in the following description are described in the above "Mode for Carrying Out the Invention", the corresponding mixing ratio (content ratio ), physical property values, parameters, etc. can. In each example, all parts and percentages are based on mass.

<Example 1>
(transparent conductive film)
As a transparent resin substrate, a film made of a cycloolefin resin elongated in the longitudinal direction (COP film, thickness 25 μm, manufactured by Nippon Zeon Co., Ltd., “ZEONOR” (registered trademark), in-plane birefringence 0.0001 nm) was used. prepared.

A diluted solution of a hard coat composition comprising a binder resin is applied to the upper surface of a transparent resin substrate, and a diluted solution of a hard coat composition containing a binder resin and a plurality of particles is applied to the lower surface of the transparent resin substrate. Then, after these were dried, both surfaces were irradiated with ultraviolet rays to cure the hard coat composition. As a result, a first cured resin layer (1 μm thick) containing no particles was formed on the upper surface of the transparent resin substrate, and a second cured resin layer (1 μm thick) containing particles was formed on the lower surface of the transparent resin substrate.

As the particles, crosslinked acryl-styrene resin particles (“SSX105” manufactured by Sekisui Jushi Co., Ltd., diameter 3 μm) were used. A urethane-based polyfunctional polyacrylate (manufactured by DIC, "UNIDIC") was used as the binder resin.

Next, a diluted solution of a composition for an optical adjustment layer containing zirconia particles and an ultraviolet curable resin ("OPSTAR Z7412" manufactured by JSR Corporation, refractive index 1.62) was applied to the upper surface of the first cured resin layer. , dried at 80° C. for 3 minutes, and then irradiated with ultraviolet rays. As a result, an optical adjustment layer (thickness: 0.1 μm) was formed on the upper surface of the first cured resin layer.

Next, a sintered body target containing indium oxide and tin oxide at a mass ratio of 70:30 was attached to a parallel plate winding type magnetron sputtering apparatus, and while conveying the laminate obtained above, Evacuation was performed until the partial pressure of water reached 5×10 ⁻⁴ Pa. Thereafter, the amounts of argon gas and oxygen gas introduced were adjusted, and an amorphous ITO layer (thickness: 25 nm) was formed on the upper surface of the optical adjustment layer by DC sputtering at an output of 12.5 kW. This produced an amorphous transparent conductive film.

(protection member)
2-Ethylhexyl acrylate (96 mol) and hydroxyethyl acrylate (4 mol) were copolymerized in ethyl acetate to obtain an acrylic copolymer solution having a weight average molecular weight of 700,000 (converted to standard polystyrene). rice field. After adding 3 parts by mass of an isocyanate cross-linking agent ("Coronate L", manufactured by Nippon Polyurethane Industry Co., Ltd.) to 100 parts by mass of the acrylic copolymer (solid content), it was diluted with ethyl acetate to obtain a solid content of A 20% by mass dilution of the pressure-sensitive adhesive composition was prepared.

As a protective resin film, a film made of cycloolefin resin elongated in the longitudinal direction (COP film, thickness 25 μm, manufactured by Nippon Zeon Co., Ltd., “ZEONOR” (registered trademark), in-plane birefringence 0.0001 nm) is prepared. did. A diluted solution of the pressure-sensitive adhesive composition was applied to the protective resin film and dried to form a pressure-sensitive adhesive layer having a thickness of 10 μm. Thus, a protective member was produced.

(Transparent conductive film laminate)
A transparent conductive film and a protective member were adhered so that the second cured resin layer and the pressure-sensitive adhesive layer were in contact with each other to obtain the transparent conductive film laminate of the example (see FIG. 1).

<Examples 2 to 6>
The materials and thicknesses of the protective resin film and the transparent resin substrate were changed to the materials and thicknesses shown in Table 1 to obtain transparent conductive film laminates of Examples. As the film made of PET, TT50-405B manufactured by Toray Advanced Film Co., Ltd. was used.

<Examples 7-8>
A transparent conductive film laminate of Example was obtained in the same manner as in Example 4, except that the pressure-sensitive adhesive composition and the conditions for treating the transparent conductive film laminate were changed as follows.

Example 7: In the production of a protective member provided with an adhesive layer, the blending amount of 2-ethylhexyl acrylate was changed from 96 mol to 90 mol, and the blending amount of hydroxyethyl acrylate was changed from 4 mol to 10 mol, The blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 5 parts by mass.

Example 8: In producing a protective member having an adhesive layer, the blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 2 parts by mass. Furthermore, after obtaining the transparent conductive film laminate, this was heated at 140° C. for 60 minutes.

<Comparative Examples 1 to 7>
A transparent conductive film laminate of a comparative example was obtained in the same manner as in Example 4, except that the pressure-sensitive adhesive composition and the conditions for treating the transparent conductive film laminate were changed as follows.

Comparative Example 1: In the production of a protective member having an adhesive layer, the blending amount of 2-ethylhexyl acrylate was changed from 96 mol to 80 mol, and the blending amount of hydroxyethyl acrylate was changed from 4 mol to 20 mol, The blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 6 parts by mass.

Comparative Example 2: In the production of a protective member having an adhesive layer, the blending amount of 2-ethylhexyl acrylate was changed from 96 mol to 90 mol, and the blending amount of hydroxyethyl acrylate was changed from 4 mol to 10 mol, The blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 6 parts by mass.

Comparative Example 3: In the production of a protective member having an adhesive layer, the blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 2 parts by mass. Furthermore, after obtaining the transparent conductive film laminate, this was heated at 150° C. for 60 minutes.

Comparative Example 4: In the production of a protective member provided with an adhesive layer, the blending amount of 2-ethylhexyl acrylate was changed from 96 mol to 98 mol, and the blending amount of hydroxyethyl acrylate was changed from 4 mol to 2 mol, The blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 1.5 parts by mass. Furthermore, after obtaining the transparent conductive film laminate, this was heated at 150° C. for 60 minutes.

Also, the material and thickness of the protective resin film and the transparent resin substrate were changed to those shown in Table 1.

Comparative Example 5: In producing a protective member having an adhesive layer, the blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 2.5 parts by mass.

Also, the material and thickness of the protective resin film and the transparent resin substrate were changed to those shown in Table 1.

Comparative Example 6: In producing a protective member having an adhesive layer, the blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 1.5 parts by mass.

Comparative Example 7: In the production of a protective member having an adhesive layer, the blending amount of 2-ethylhexyl acrylate was changed from 96 mol to 98 mol, and the blending amount of hydroxyethyl acrylate was changed from 4 mol to 2 mol, The blending amount of the isocyanate-based cross-linking agent was changed from 3 parts by mass to 1 part by mass.

Also, the material and thickness of the protective resin film and the transparent resin substrate were changed to those shown in Table 1.

<Measurement of surface resistance>
The surface resistance of the amorphous ITO layer of each transparent conductive film laminate of each example and each comparative example was measured by a four-probe method and found to be 340Ω/□. Also, the transparent conductive film was heated at 130° C. for 90 minutes to crystallize the ITO layer. When the surface resistance of the crystallized ITO layer was measured by the four-probe method, it was 100Ω/□.

<Measurement of peel strength (breakage measurement)>
The transparent conductive film laminates of each example and each comparative example were heat-treated at 130° C. for 90 minutes to crystallize the ITO layer.

After that, the crystallized transparent conductive film laminate was cut into a width of 50 mm and a length of 200 mm. (manufactured by Tester Sangyo Co., Ltd.). Subsequently, one end in the longitudinal direction of the protective member 2 (protective resin film) in the crystallized transparent conductive film laminate was gripped by the movable stage 13, and the peeling force at a peeling angle of 180° was applied at a tensile speed of 10 m/min ( N/50 mm) (peeling force Y of pressure-sensitive adhesive layer) was measured (see FIG. 3).

In Comparative Examples 5 to 7, a broken portion was confirmed in the COP base material of the protective member or the transparent conductive film. After reinforcing the broken portion with a reinforcing tape, the peel strength Y of the pressure-sensitive adhesive layer was measured.

The thickness (μm) of the protective member or the COP film of the transparent conductive film, whichever is thinner, was plotted as x, and the measured peeling force (N/50 mm) as Y, and plotted on a graph. This is shown in FIG. Among these plots, at the same thickness (x), the midpoint between the maximum value of the peel force Y that did not break and the minimum value of the peel force Y that broke was obtained, and based on the power approximation that approximates it, An approximation curve (when X is 40 or less) was drawn. On the other hand, when X is 40 or more, a straight line passing through Comparative Examples 3 and 4 is drawn.

<Measurement of presence or absence of air bubbles>
Side cross-sectional views of the transparent conductive film laminates of Examples and Comparative Examples were observed when they were subjected to heat treatment at 130° C. for 90 minutes. A case where no air bubbles were observed in the pressure-sensitive adhesive layer was evaluated as ◯, and a case where many air bubbles were observed in the pressure-sensitive adhesive layer was evaluated as x. Table 1 shows the results.

<Measurement of peelability>
The transparent conductive film laminates of each example and each comparative example were crystallized in the same manner as in <measurement of peeling force> to obtain crystallized transparent conductive film laminates.

Next, one end of the transparent conductive film in the longitudinal direction of the crystallized transparent conductive film laminate was pulled at a peel angle of 180° for a long period of time using a peel force measuring device, and peeled continuously.

At this time, when the transparent conductive film could not be peeled off smoothly and adjustment of the peel force measuring device was required, x was given, and when the transparent conductive film could be peeled off smoothly without the above adjustment, ○ was given. evaluated.

<Discussion>
As can be seen from FIG. 4, when the thickness X of the COP substrate is 40 μm or less, the thickness X of the COP substrate and the peeling force Y of the pressure-sensitive adhesive layer 5 are calculated by formula (1) (Y<0.0003X ^2.7 ). In any of Examples 1 to 8 and Comparative Examples 1 to 3 that satisfy , the COP substrate is not damaged. On the other hand, in Comparative Examples 5 to 7 where the thickness X and the peel force Y did not satisfy the formula (1), the COP substrates were damaged. In Comparative Examples 1 and 2, since the peeling force Y is less than 2.0 (N/50 mm), the formula (2) is not satisfied and air bubbles are observed. In Comparative Example 3, since the peeling force Y was 6.0 (N/50 mm) or more, the expression (2) was not satisfied, and the force required for peeling was increased. Peeling becomes difficult.

On the other hand, when the thickness X of the COP substrate exceeds 40 μm, considering Comparative Example 4 where the peel force Y is 8.0 (N / 50 mm) or more and does not break, if at least Y ≤ 0.0333x + 4.67 is satisfied , it is believed that the COP substrate does not fracture. However, in Comparative Example 4, since the peeling force Y is 6.0 (N/50 mm) or more, the formula (2) is not satisfied, and the force required for peeling increases, which places a burden on the peeling device. Smooth peeling becomes difficult.

1 transparent conductive film laminate 2 protective member 3 transparent conductive film 4 protective resin film 5 adhesive layer 6 transparent resin substrate 7a first cured resin layer 7b second cured resin layer 8 optical adjustment layer 9 transparent conductive layer

Claims (8)

Equipped with a protective resin film, an adhesive layer and a transparent conductive film in this order,
The transparent conductive film comprises a transparent resin substrate and a transparent conductive layer in this order,
At least one of the protective resin film and the transparent resin substrate contains a cycloolefin resin,
A transparent conductive film laminate, characterized by satisfying the following formulas (1) and (2).
Y < 0.0003X ^2.7 (1)
0.2≦Y<6.0 (2)
(In the formula, X represents the thickness (μm) of the protective resin film or the transparent resin substrate containing the cycloolefin resin. However, both the protective resin film and the transparent resin substrate When a cycloolefin-based resin is contained, the value of the smaller thickness is shown.
Y indicates the peel strength (N/50 mm) of the pressure-sensitive adhesive layer under the conditions of a tensile speed of 10 m/min and a peel angle of 180°. ) The transparent conductive film laminate according to claim 1, wherein the transparent resin substrate contains a cycloolefin resin. The transparent conductive film laminate according to claim 1, wherein the protective resin film contains a cycloolefin-based resin or a polyester-based resin. 2. The transparent conductive film laminate according to claim 1, wherein the protective resin film and the transparent resin substrate each have a thickness of 100 [mu]m or less. 2. The transparent film according to claim 1, wherein the transparent conductive film comprises a second cured resin layer, the transparent resin substrate, a first cured resin layer, an optical adjustment layer and the transparent conductive layer in this order. Conductive film laminate. 2. The transparent conductive film laminate according to claim 1, wherein the transparent conductive layer contains an indium-tin composite oxide. A preparation step of preparing a transparent conductive film comprising a transparent resin substrate and a transparent conductive layer in this order and a protective member comprising a protective resin film and an adhesive layer in this order,
Bonding to obtain a transparent conductive film laminate by bonding the transparent conductive film and the protective member so that the adhesive layer is in contact with the transparent resin substrate side of the transparent conductive film process,
a heating step of heating the transparent conductive film laminate to crystallize the transparent conductive layer, and
A peeling step of peeling the protective member from the transparent conductive film after the heating step,
At least one of the protective resin film and the transparent resin substrate contains a cycloolefin resin,
After the heating step, the following formulas (1) and (2)
Y < 0.0003X ^2.7 (1)
0.2≦Y<6.0 (2)
(In the formula, X represents the thickness (μm) of the protective resin film or the transparent resin substrate containing the cycloolefin resin. However, both the protective resin film and the transparent resin substrate When a cycloolefin-based resin is contained, the value of the smaller thickness is shown.
Y indicates the peel strength (N/50 mm) of the pressure-sensitive adhesive layer under the conditions of a tensile speed of 10 m/min and a peel angle of 180°. )
A method for producing a transparent conductive film, characterized by satisfying 8. The production of the transparent conductive film according to claim 7, further comprising an optical inspection step of optically inspecting the transparent conductive film laminate after the heating step and before the peeling step. Method.

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