KR20180089404A - A transparent conductive film laminate, and a touch panel - Google Patents

Abstract

A transparent conductive film laminate capable of sufficiently suppressing iridescence caused by reflection of external light even when observed from a tilted direction, and a touch panel including the transparent conductive film laminate.
A transparent conductive film laminate having a transparent conductive film (6), a first transparent resin film (4), an adhesive layer (8) and a second transparent resin film (9) in this order, wherein the first transparent resin film ) Has an in-plane retardation value R0 ₁ of 150 nm or less and the second transparent resin film 9 has an in-plane retardation value R0 ₂ of 10000 nm or more and a polar angle 30 retardation value in the direction inclined to ° characterized in that at least R30 is ₂ 10000 ㎚.

Description

A transparent conductive film laminate, and a touch panel

The present invention relates to a transparent conductive film laminate having a transparent conductive film and a plurality of transparent resin films, and a touch panel including the transparent conductive film laminate.

Recently, with the spread of PCs with tablets, smart phones, and touch panels, opportunities for handling electronic devices in the open are increasing. When a transparent conductive film using a polyethylene terephthalate (PET) film is used at that time, the in-plane retardation (generally 1000 to 2000 Nm), which causes a problem that the visibility of the display is significantly lowered.

For this reason, development of a transparent conductive film using a substrate (polycycloolefin or the like) having a small retardation value has been under way. However, polycycloolefins and the like have a demerit that the material strength is low, and use of a material which is inexpensive and high in strength has been studied. Another problem is that when the thickness is made thinner in order to reduce the retardation by using other materials, the handling property at the time of manufacturing or processing the member is lowered.

For these reasons, Patent Document 1 proposes a transparent conductive film based on a transparent resin film made of stretched polyester or the like having an in-plane retardation value of 4000 nm or more. According to this transparent conductive film, color unevenness is less likely to occur even when viewed through polarized sunglasses.

For the purpose of obtaining the same effect, Patent Document 2 discloses a transparent conductive film having a substrate in which a cyclic retardation film having an in-plane retardation value of 3000 nm or more and a retardation film having an in-plane retardation value of less than 3000 nm are laminated have.

Japanese Patent Application Laid-Open No. 2004-214069 Japanese Laid-Open Patent Publication No. 2014-157238

However, as in Patent Document 2, when a ring-retardation film and a retardation film are laminated, rainbow stains when observed from the front are improved, but when observed from a tilted direction (polar angle is 30 to 60 degrees) It is found that iridescence spots caused by reflection of light are generated.

It is therefore an object of the present invention to provide a transparent conductive film laminate capable of sufficiently suppressing iridescence caused by reflection of external light even when observed from a tilted direction, and a touch panel including the transparent conductive film laminate.

The present inventors have intensively studied a result, a phase difference value R30 ₂ in a tilted orientation and in-plane retardation value R0 ₂ of archaic retardation film within a predetermined range, and further fed in-plane retardation value of the other retardation film in order to solve the aforementioned problems R0 < ₁ > within a predetermined range, the present invention has been accomplished.

That is, the transparent conductive film laminate of the present invention is a transparent conductive film laminate having a transparent conductive film, a first transparent resin film, an adhesive layer and a second transparent resin film in this order, and the in-plane retardation value R0 ₁ is below 150 ㎚, the second transparent resin film, in the direction in which inclined at a polar angle 30 ° from the in-plane retardation value R0 ₂ is more than 10000 ㎚, the direction normal to the direction of the azimuth angle 45 ° to the slow axis the retardation value in R30 is greater than or equal to ₂ 10000 ㎚ characterized. The various physical property values in the present invention are values measured by the method employed in Examples and the like.

In general, a biaxially stretched polyester-based resin film has an in-plane retardation of about 1000 to 2000 nm, and when used in a substrate of a transparent conductive film laminate, the effect of depolarizing polarized light due to wavelength dispersion is insufficient And rainbow stains occur. On the other hand, if the in-plane retardation less than 3000 ㎚, by reducing the effect of wavelength dispersion, becomes larger, the effect of bipyeon mineralization polarization, the as in the present invention, each of the retardation value R0 _1, R0 _2, R30 ₂ to an appropriate range , Iridescent unevenness caused by reflection of external light can be sufficiently suppressed even when observed from a tilted direction, as shown by the results of the embodiment.

The details of the reason are not clear, but are considered as follows. In other words, in the direction tilted from the normal direction, the retardation value of the second transparent resin film changes from the in-plane retardation value, but when viewed from a tilted direction (polar angle is 30 to 60 degrees) The influence becomes large, and iridescence unevenness caused by the reflection of external light is likely to occur. On the other hand, when the in-plane retardation value R0 _2, a retardation value R30 ₂ in the direction in which inclined at a polar angle 30 ° from the normal direction in the direction of the azimuth angle 45 ° to the slow axis as well as in the present invention to more than 10000 ㎚, A sufficient retardation value can be ensured even for light from an oblique direction. Therefore, even when observed from a direction inclined at all azimuth angles, rainbow streaks caused by reflection of external light can be suppressed.

In the above-mentioned first transparent resin film, it is preferable that the thickness direction retardation value Rth ₁ is 2000 nm or less. First transparent as a small thickness direction retardation value Rth _one of the resin film, the first because of the transparent resin film, it can reduce the influence on the retardation caused by the change of the polar angle, a rainbow of when observed from the inclined direction, It is considered that the suppression effect of the stain is obtained more reliably.

It is preferable that the second transparent resin film is an elongated body or a square shaped body, and the orientation axis has an angle of 10 to 45 degrees with respect to a long side or a short side. The transparent conductive film is often used by being laminated on a quadrangular optical display device such as a liquid crystal cell, and the light from the optical display device is often parallel or perpendicular to its long side. Therefore, in the present invention, the orientation axis of the second transparent resin film has an angle of 10 to 45 degrees with respect to the long side or short side, so that the slow axis can be easily arranged at an angle of 10 to 45 degrees with respect to the polarization, The action of polarizing the circularly polarized light by the film becomes large, and the effect of suppressing sufficient iridescence is easily obtained.

It is preferable that at least one optical adjustment layer is provided between the first transparent resin film and the transparent conductive film. Since the refractive index can be controlled by the optical adjusting layer, the difference in reflectance between the pattern forming portion and the pattern opening portion when the transparent conductive film is patterned can be reduced, the transparent conductive film pattern can hardly be seen, The visibility is improved.

It is preferable that a cured resin layer is provided on at least one surface of the first transparent resin film or the second transparent resin film. The cured resin layer functions as a hard coat layer for preventing scratches and the like during transportation, and can function as an anti-blocking layer by generating irregularities on the surface.

On the other hand, the touch panel of the present invention is characterized by including the transparent conductive film laminate of the present invention. By using the transparent conductive film laminate of the present invention, it is possible to provide a touch panel capable of sufficiently suppressing rainbow stains caused by reflection of external light even when observed from a tilted direction.

1 is a schematic cross-sectional view of a transparent conductive film laminate according to an embodiment of the present invention.
2 is a schematic cross-sectional view of a transparent conductive film laminate according to an embodiment of the present invention.
3 is a schematic cross-sectional view of a transparent conductive film laminate according to an embodiment of the present invention.
4 is a schematic cross-sectional view of a transparent conductive film laminate according to an embodiment of the present invention.

≪ Structure of laminate >

1 to 3, the transparent conductive film laminate of the present invention has a transparent conductive film 6, a first transparent resin film 4, an adhesive layer 8, and a second transparent resin film 9, It is preferable that at least one optical adjustment layer 7 is provided between the first transparent resin film 4 and the transparent conductive film 6. [ 2 to 3, at least one surface of the first transparent resin film 4 or the second transparent resin film 9 is coated with the anti-blocking layer 3, the hard coat layer 5, etc. Of a cured resin layer. 4, the pressure-sensitive adhesive layer 2 and the protective film 1 are laminated on the surface of the second transparent resin film 9 on which the transparent conductive film 6 is not formed, In this case, the carrier film 10 is composed of the pressure-sensitive adhesive layer 2 and the protective film 1.

(First transparent resin film)

As the first transparent resin film, various plastic films having transparency can be used as long as the retardation is within a predetermined range.

Examples of the material of the plastic film include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycycloolefin, polyacetate, polyethersulfone, polycarbonate, polyamide, polyimide, (meth) Polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, polyphenylene sulfide, and the like. Among these materials, it is preferable to use a polyester-based resin film, polycycloolefin, or polycarbonate from the viewpoint of easily controlling the heat resistance during sputtering and the retardation within a predetermined range.

Particularly, as the first transparent resin film, a biaxially stretched polyester-based resin film is preferably used in view of sufficient strength, low material cost, and good productivity. The term "biaxially stretched" means that the film is stretched in at least two directions, and the two-direction stretching may be simultaneous or sequential.

Examples of the polyester-based resin include a polyester-based resin selected from a polyester, a modified polyester, and blends thereof. As the polyester, for example, those obtained by condensation polymerization of a carboxylic acid component and a polyol component can be used.

Examples of the carboxylic acid component include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and alicyclic dicarboxylic acids. Examples of the aromatic dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, benzylmalonic acid, 1,4-naphthalic acid, diphenic acid, 4,4'-oxybenzoic acid and 2,5-naphthalenedicarboxylic acid. . Examples of the aliphatic dicarboxylic acid include malonic acid, dimethyl malonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, Sebacic acid, fumaric acid, maleic acid, itaconic acid, thiodipropionic acid and diglycolic acid. Examples of the alicyclic dicarboxylic acid include 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,4- Cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, and adamantanedicarboxylic acid. The carboxylic acid component may be a derivative such as an ester, a chloride or an acid anhydride, and examples thereof include dimethyl 1,4-cyclohexanedicarboxylate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl isophthalate, terephthalic acid Dimethyl and terephthalic acid diphenyl. The carboxylic acid component may be used alone, or two or more kinds may be used in combination.

Representative examples of the polyol component include divalent alcohols. Examples of dihydric alcohols include aliphatic diols, alicyclic diols and aromatic diols. The aliphatic diol includes, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2,4- Propylene diol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl- Butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,6-hexane Diols. The alicyclic diols include, for example, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, spiroglycol, tricyclodecanedimethanol, adamantanediol , And 2,2,4,4-tetramethyl-1,3-cyclobutanediol. Examples of the aromatic diol include 4,4'-thiodiphenol, 4,4'-methylenediphenol, 4,4'- (2-norbornylidene) diphenol, 4,4'- (2, 6-cyclophenol) 2,5-naphthalene, 4,4'-isopropylidene phenol, 4,4'-isopropylidenebis Diol and p-xylene diol. The polyol component may be used alone or in combination of two or more.

Preferred examples of the carboxylic acid component include terephthalic acid, isophthalic acid and 2,5-naphthalenedicarboxylic acid. Preferable examples of the polyol component include ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, 1,3-cyclohexanedimethanol and 1,4-cyclohexanedimethanol.

The structure of the polyester is determined by a combination of the above-mentioned monomers. Therefore, preferable examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycyclohexylene terephthalate, and copolymers thereof , Blends and modified bodies.

The first transparent resin film is produced as a biaxially stretched elongated film (elongated body). As used herein, the term " elongated shape " refers to a thin and long shape having a ratio of length to width of 10 or more. The ratio of the length to the width of the transparent resin film is preferably 30 or more, and more preferably 100 or more. In one embodiment, the transparent resin film is an elongated body rolled in a roll shape. In another embodiment, the transparent resin film is a rectangular shaped body.

The first transparent resin film may have an orientation axis at any angle with respect to the long side or the short side. From the viewpoint of productivity, it is preferable that the orientation axis is parallel to the long side or the short side.

The in-plane retardation R0 _one of the first transparent resin film, in view of the height than the inhibitory effect of rainbow stains, and 0 ~ 150 ㎚, and preferably 10 ~ 130 ㎚, and more preferably 20 ~ 110 ㎚.

Herein, the in-plane retardation R0 (R0 ₁ , R0 ₂ ) is the in-plane retardation of the film measured at a wavelength of 590 nm at 23 ° C. R0 is obtained by the formula: R0 = (nx-ny) xd, where d (nm) is the thickness of the film. Here, nx is a refractive index in the direction in which the in-plane refractive index is the maximum (i.e., the slow axis direction), and ny is the refractive index in the plane perpendicular to the slow axis.

The thickness direction retardation Rth ₁ of the first transparent resin film, in view of the inhibitory effect of rainbow stains, together with the more increasing, for obtaining a sufficient strength, and preferably not more than 2000 ㎚, more preferably 350 ~ 950 ㎚, more And preferably 300 to 900 nm.

Here, the retardation in the thickness direction Rth (Rth ₁ ) is the retardation in the thickness direction of the film measured at a wavelength of 590 nm at 23 캜. Rth is obtained by the formula: Rth = (nx - nz) xd, where d (nm) is the thickness of the film. Here, nx is the refractive index in the direction in which the in-plane refractive index is the maximum (i.e., the slow axis direction), and nz is the refractive index in the thickness direction.

In the present invention, the ratio R0 ₁ / Rth ₁ of the phase difference is important, and the inhibitory effect of rainbow stains than with the increasing, in view of obtaining a sufficient strength, non-R0 ₁ / Rth ₁ of the phase difference is, and 0.01 to 0.5 are preferred , More preferably 0.02 to 0.47, and still more preferably 0.04 to 0.45.

The dimensional transparency of the first transparent resin film after heating at 80 DEG C for 240 hours is preferably 2.0% or less, and more preferably 1.0% or less.

The degree of crystallinity of the first transparent resin film measured by X-ray diffraction (XRD) is preferably 25% or more, and more preferably 30% or more. The upper limit of the crystallinity is, for example, 70%. When the degree of crystallinity is in this range, there is an advantage that the film is not shrunk when heated after stretching, and optical properties such as retardation and orientation angle are hardly changed.

The thickness of the first transparent resin film is preferably 5 to 50 占 퐉, more preferably 7 占 퐉 to 40 占 퐉, and still more preferably 10 占 퐉 to 40 占 퐉, from the viewpoint of obtaining the retardation in the in- More preferably 30 mu m.

The glass transition temperature of the polyester-based resin is preferably 65 ° C to 80 ° C, and more preferably 70 ° C to 75 ° C. If the glass transition temperature is excessively low, desired dimensional shrinkage may not be obtained. If the glass transition temperature is excessively high, the molding stability at the time of film forming may deteriorate, and transparency of the film may be deteriorated. The glass transition temperature is determined in accordance with JIS K 7121 (1987).

The weight average molecular weight of the polyester-based resin is preferably 10,000 to 100,000, and more preferably 15,000 to 50,000. With such a weight average molecular weight, it is easy to handle during molding, and a film having excellent mechanical strength can be obtained.

The surface of the first transparent resin film is subjected to an etching treatment such as sputtering, a corona discharge, a flame, an ultraviolet ray irradiation, an electron beam irradiation, a chemical conversion and an oxidization in advance, The adhesion of the optical adjustment layer, the cured resin layer, the transparent conductive film, and the like may be improved. Before the formation of the optical adjustment layer or the like, the surface of the first transparent resin film may be damped or cleaned, if necessary, by solvent cleaning or ultrasonic cleaning.

(Second transparent resin film)

As the second transparent resin film, various plastic films having transparency can be used as far as the retardation falls within a predetermined range.

Examples of the material of the plastic film include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycycloolefin, polyacetate, polyethersulfone, polycarbonate, polyamide, polyimide, (meth) Polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, polyphenylene sulfide, and the like.

Of these materials, a polyester-based resin film, polycycloolefin and polycarbonate are preferable from the viewpoint of easily controlling the retardation within a predetermined range. In particular, a biaxially stretched polyester-based resin film is preferably used as the second transparent resin film in view of sufficient strength, low cost of materials, and good productivity.

As the polyester resin used as the second transparent resin film, any of the polyester resins exemplified as the first transparent resin film may be used.

The second transparent resin film is produced as a biaxially stretched elongated film. As used herein, the term " elongated shape " refers to a thin and long shape having a ratio of length to width of 10 or more. The ratio of the length to the width of the second transparent resin film is preferably 30 or more, and more preferably 100 or more. In one embodiment, the second transparent resin film is wound in a roll form.

The second transparent resin film preferably has an orientation axis at an angle of 10 to 45 degrees with respect to a long side or a short side, more preferably an angle of 20 to 45 degrees, and most preferably an angle of 30 to 45 degrees . In the transparent conductive film of the present invention, it is preferable that the orientation axis of the second transparent resin film is arranged at an angle of 10 to 80 degrees with respect to the vibration direction of the linearly polarized light emitted from the display device, More preferably, at an angle of 30 to 60 DEG.

Therefore, the direction of the slow axis of the elongated film is in the range of 30 ° to 60 °, preferably in the range of 38 ° to 52 °, more preferably in the range of 43 ° to 47 ° to the longitudinal direction over the entire width direction of the film. Deg., And more preferably, the slow axis direction is at an angle of about 45 DEG with respect to the long direction. The second transparent resin film can obtain a second transparent resin film having a slow axis in the direction tilted with excellent axial precision by applying the manufacturing method including the tilt stretching.

The slow axis of the second transparent resin film and the slow axis of the first transparent resin film can be arranged at any angle. However, from the viewpoint of productivity and the like, the angle formed by the slow axes of both is preferably 25 to 75 degrees, more preferably 30 to 65 degrees.

The in-plane retardation R0 ₂ of the second transparent resin film is preferably 10000 to 20000 nm, and more preferably 10000 to 15000 nm, from the viewpoint of the film strength, of 10000 nm or more.

The second retardation value in the direction in which inclined at a polar angle 30 ° from the normal direction in the direction of the azimuth angle 45 ° to the slow axis of the transparent resin film R30 ₂ is not less than 10000 ㎚, in view of film strength, preferably 11 000 - 20000 nm, and more preferably 12000 to 18000 nm.

Retardation R30 ₂ is a retardation of the film measured at a wavelength of 590 ㎚ light according to 23 ℃, actually, the phase difference in the direction in which inclined at a polar angle 30 ° from the normal direction in the direction of the azimuth angle 45 ° to the slow axis Is measured and measured by a polarization / phase difference measurement system.

A second transparent thickness of the resin film, together with obtaining the retardation value R0 ₂ and R30 ₂ as described above, in view of improving the handling properties as a laminate, and is 75 ~ 250 ㎛ preferable, and 1000 ~ 225 ㎛ more preferably , And more preferably from 125 to 200 mu m.

The polyester-based resin can be formed into a film by any suitable method. The obtained polyester-based resin film can be biaxially stretched in a longitudinal and transverse direction by biaxial stretching. At that time, as disclosed in Japanese Laid-Open Patent Publication No. 2015-72376, a second transparent resin film having an orientation axis in a tilted direction can be preferably obtained by providing it to a manufacturing method including a tilt stretch.

That is, the left and right ends of the film to be stretched are gripped by the left and right clips of variable pitch type in which the clip pitch in the longitudinal direction changes (step A: gripping step); Preheating the film (Process B: preheating process); The clip pitch of the right and left clips is independently varied to tilt and stretch the film (Step C: stretching step); Crystallizing the film by heat treatment in a state where the clip pitch of the left and right clips is kept constant as required (Process D: crystallization process); And releasing the clip holding the film (step E: releasing step), the second transparent resin film used in the present invention can be preferably produced by a manufacturing method including inclination stretching.

The second in the production of the transparent resin film, in order to control the retardation value R30 ₂ to a predetermined range, nx, ny, nz nx - so that the relationship of - {nz ny} - ny < {nx nz}, nx < , It is preferable to adjust the conditions of the biaxial stretching.

The surface of the second transparent resin film is subjected to an etching treatment such as sputtering, a corona discharge, a flame, an ultraviolet ray irradiation, an electron beam irradiation, a chemical conversion and an oxidization in advance to form a film on the second transparent resin film The adhesion of the optical adjustment layer, the cured resin layer, the transparent conductive film, and the like may be improved. Before the formation of the optical adjustment layer or the like, the surface of the second transparent resin film may be damped and cleaned by solvent cleaning or ultrasonic cleaning as necessary.

(Adhesive layer)

The adhesive layer may be formed of a curable adhesive such as an active energy ray curable type, a thermosetting type or a natural curing type, or a pressure sensitive adhesive (pressure sensitive adhesive), and it is preferable to use an active energy ray curable adhesive. As the pressure-sensitive adhesive, a pressure-sensitive adhesive described later can be used.

For the formation of the active energy ray-curable adhesive layer, for example, a radical-curable adhesive is preferably used. As the radical curing type adhesive, an active energy ray curing type adhesive such as an electron beam curable type or an ultraviolet ray curable type can be exemplified. In particular, an ultraviolet curable adhesive which is preferably curable in a short time, is preferably an active energy ray curable type, and further curable with a low energy.

As ultraviolet curable adhesives, radical curing curable adhesives and cationic curable adhesives can be categorized. In addition, the radical polymerization curing type adhesive can be used as a thermosetting adhesive.

Examples of the curable component of the radical polymerization curable adhesive include a compound having a (meth) acryloyl group and a compound having a vinyl group. These curable components may be used either monofunctional or bifunctional or more. These curable components may be used singly or in combination of two or more. As the curable component, for example, a compound having a (meth) acryloyl group is preferable.

Specific examples of the compound having a (meth) acryloyl group include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) (Meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, s- (Meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-hexyl Acrylates such as n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl- ) Acrylic acid (having 1 to 20 carbon atoms) alkyl esters.

Examples of the compound having a (meth) acryloyl group include a cycloalkyl (meth) acrylate (e.g., cyclohexyl (meth) acrylate, cyclopentyl (meth) (Meth) acrylate (for example, benzyl (meth) acrylate and the like), polycyclic (meth) acrylates (for example, 2-isobornyl (meth) acrylate and 2-norbornylmethyl (Meth) acrylate), hydroxyl group-containing (meth) acrylate esters (for example, methacrylic acid esters) (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2,3-dihydroxypropylmethyl-butyl (meth) methacrylate and the like), an alkoxy group or a phenoxy group- (Meth) acrylate esters (such as 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) (Meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethylcarbitol Methacrylic acid esters such as glycidyl (meth) acrylate, halogen-containing (meth) acrylic esters (such as 2,2,2-trifluoroethyl (meth) acrylate, (Meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) acrylate, heptadecafluoro (meth) acrylate, (Meth) acrylate), and alkylaminoalkyl (meth) acrylates (e.g., dimethylaminoethyl (meth) acrylate).

Examples of the compound having a (meth) acryloyl group other than the above include hydroxyethyl acrylamide, N-methylol acrylamide, N-methoxymethylacrylamide (SP value: 22.9), N-ethoxymethylacrylamide , And amide group-containing monomers such as (meth) acrylamide. And nitrogen-containing monomers such as acryloylmorpholine.

Examples of the curable component of the radical polymerization curable adhesive include compounds having a plurality of polymerizable double bonds such as (meth) acryloyl groups and vinyl groups, and the compounds may be mixed with an adhesive component as a crosslinking component You may. Examples of the curable component which becomes a crosslinking component include, for example, tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, di (Manufactured by Kyowa Chemical Industry Co., Ltd.), light acrylate DGE-4A (manufactured by Kyowa Chemical Industry Co., Ltd.), acrylic acid monoacrylate SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer), and the like can be given. If necessary, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, and various (meth) acrylate monomers may be cited.

The radical polymerization curing type adhesive includes the above-mentioned curable component, and in addition to the above components, a radical polymerization initiator is added depending on the type of curing. When the adhesive is used in an electron beam hardening type, it is not particularly necessary to include a radical polymerization initiator in the adhesive, but when it is used in an ultraviolet curing type or a thermosetting type, a radical polymerization initiator is used. The amount of the radical polymerization initiator used is usually about 0.1 to 10 parts by weight, preferably 0.5 to 3 parts by weight, per 100 parts by weight of the curable component. In addition, a photo-sensitizer may be added to the radical polymerization curing type adhesive, as needed, such as a carbonyl compound or the like, which increases the curing rate and sensitivity by electron beams. The amount of the photosensitizer to be used is usually about 0.001 to 10 parts by weight, preferably 0.01 to 3 parts by weight, per 100 parts by weight of the curable component.

Examples of the curable component of the cationic polymerization curable adhesive include compounds having an epoxy group and an oxetanyl group. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used. As a preferable epoxy compound, a compound having at least two epoxy groups and at least one aromatic ring in the molecule, or a compound having at least two epoxy groups in the molecule, at least one of which has two adjacent carbon atoms constituting an alicyclic ring And the like, and the like.

Examples of the water-based curable adhesive include vinyl polymer, gelatin, vinyl latex, polyurethane, isocyanate, polyester, epoxy and the like for forming the adhesive layer. The adhesive layer composed of such an aqueous adhesive can be formed as a coating and drying layer of an aqueous solution. When preparing the aqueous solution, a crosslinking agent, a catalyst such as another additive, or an acid can be added as needed.

As the water-based adhesive, it is preferable to use an adhesive containing a vinyl polymer, and as the vinyl polymer, a polyvinyl alcohol-based resin is preferable. As the polyvinyl alcohol-based resin, an adhesive containing a polyvinyl alcohol-based resin having an acetacetyl group is more preferable in terms of improving durability. As the crosslinking agent that can be blended in the polyvinyl alcohol-based resin, a compound having at least two functional groups having reactivity with the polyvinyl alcohol-based resin can be preferably used. For example, it is possible to use a boric acid or borax, a carboxylic acid compound, an alkyldiamine, an isocyanate, an epoxy, a monoaldehyde, a dialdehyde, an amino- And oxides thereof.

The adhesive forming the curable adhesive layer may suitably contain an additive if necessary. Examples of the additive include a coupling agent such as a silane coupling agent and a titanium coupling agent, an adhesion promoter represented by ethylene oxide, an additive for improving wettability with a transparent protective film, an acryloxy system compound, a hydrocarbon system (natural or synthetic resin) An antioxidant, a dye, a processing aid, an ion trap, an antioxidant, a tackifier, a filler (other than a metal compound filler), a plasticizer, a leveling agent, a foaming agent Stabilizers such as inhibitors, antistatic agents, heat stabilizers, and moisture stabilizers.

The coating method of the adhesive is appropriately selected depending on the viscosity of the adhesive and the intended thickness. Examples of the coating method include a reverse coater, a gravure coater (direct, reverse or offset), a bar reverse coater, a roll coater, a die coater, a bar coater and a rod coater. In addition, a coating method such as a dipping method can be appropriately used.

The thickness of the adhesive layer is preferably 0.01 to 10 mu m. More preferably 0.1 to 5 占 퐉, and still more preferably 0.3 to 4 占 퐉.

(Cured resin layer)

The cured resin layer includes a first cured resin layer formed on one side of the first main surface of the first transparent resin film or the second transparent resin film and a second cured resin layer formed on the side of the second main surface on the opposite side . Since the transparent resin film is prone to scratches in each process such as formation of a transparent conductive film, patterning of a transparent conductive film, mounting on an electronic device, and the like, the first cured resin layer and the second It is preferable to form a cured resin layer.

The cured resin layer is a layer obtained by curing the curable resin. As the resin to be used, a thermosetting resin, an ultraviolet-curable resin, an electron beam-curable resin, a two-liquid mixed resin, and the like can be used as the resin having sufficient strength as a film after formation of a cured resin layer and having transparency without particular limitation . Among them, an ultraviolet curable resin which can efficiently form a cured resin layer by a simple processing operation by a curing treatment by ultraviolet irradiation is preferable.

Examples of the ultraviolet curable resin include various types such as a polyester type, an acrylic type, a urethane type, an amide type, a silicone type and an epoxy type, and include ultraviolet curable type monomers, oligomers, polymers and the like. The ultraviolet curable resin preferably used is an acrylic resin or an epoxy resin, more preferably an acrylic resin.

The cured resin layer may contain particles. By blending the particles in the cured resin layer, it is possible to form ridges on the surface of the cured resin layer, and the anti-blocking property can be preferably imparted to the transparent conductive film.

As the above-mentioned particles, those having transparency such as various metal oxides, glass, and plastic can be used without particular limitation. For example, inorganic particles such as silica, alumina, titania, zirconia and calcium oxide, and various polymers such as polymethyl methacrylate, polystyrene, polyurethane, acrylic resin, acryl-styrene copolymer, benzoguanamine, melamine and polycarbonate Based organic particles and silicon-based particles, which are crosslinked or uncrosslinked. One or more of these particles can be appropriately selected and used, but organic particles are preferred. As the organic particles, an acrylic resin is preferable from the viewpoint of the refractive index.

The optimum particle diameter of the particles can be suitably set in consideration of the relationship between the protrusion of the ridge of the cured resin layer and the thickness of the flat region other than the ridge, and the like, and is not particularly limited. From the viewpoint of sufficiently imparting blocking resistance to the transparent conductive film and sufficiently suppressing the rise of haze, the particle size of the particles is preferably from 0.1 to 3 mu m, more preferably from 0.5 to 2.5 mu m. In the present specification, the term &quot; minimum particle diameter &quot; refers to particle diameter indicating the maximum value of the particle distribution, and is measured under a predetermined condition (Sheath Solution: ethyl acetate, measurement mode: HPF measurement, measurement method: total count). The sample to be measured is prepared by diluting the particles with 1.0% by weight of ethyl acetate and uniformly dispersing them using an ultrasonic cleaner.

The content of the particles is preferably 0.05 to 1.0 part by weight, more preferably 0.1 to 0.5 part by weight, and even more preferably 0.1 to 0.2 part by weight based on 100 parts by weight of the solid content of the resin composition. If the content of the particles in the cured resin layer is small, it is likely that ridges sufficient to impart anti-blocking property and slippery property to the surface of the cured resin layer become difficult to be formed. On the other hand, if the content of the particles is too large, the haze of the transparent conductive film tends to increase due to light scattering caused by the particles, and the visibility tends to decrease. If the content of the particles is too large, streaks may be generated at the time of forming the cured resin layer (at the time of applying the solution), thereby impairing the visibility and uneven electrical characteristics of the transparent conductive film.

The cured resin layer is formed by applying a resin composition containing each curable resin and particles, a crosslinking agent, an initiator, a sensitizer, and the like as needed, on a transparent resin film, and when the resin composition contains a solvent, And curing it by application of heat, active energy rays or both. The heat may be a known means such as an air circulating oven or an IR heater, but is not limited to these methods. Examples of the active energy ray include, but are not limited to, ultraviolet ray, electron ray, gamma ray and the like.

The cured resin layer can be formed by a wet coating method (coating method) or the like using the above materials. For example, when indium oxide (ITO) containing tin oxide is formed as a transparent conductive film, crystallization time of the transparent conductive film can be shortened if the surface of the cured resin layer as a ground layer is smooth. From this viewpoint, it is preferable that the cured resin layer is formed by a wet coating method.

The thickness of the cured resin layer is preferably 0.5 탆 to 5 탆, more preferably 0.7 탆 to 3 탆, and most preferably 0.8 탆 to 2 탆. When the thickness of the cured resin layer is within the above range, it is possible to prevent film wrinkles in prevention of scratches and curing shrinkage of the cured resin layer, thereby preventing the visibility of the touch panel and the like from deteriorating.

(Transparent conductive film)

The transparent conductive film can be formed on the transparent resin film, but is preferably formed on the first cured resin layer formed on the first principal surface side of the transparent resin film. The constituent material of the transparent conductive film is not particularly limited as long as it contains an inorganic substance and may be selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, A metal oxide of at least one selected metal is preferably used. The metal oxide may further contain a metal atom represented by the above-mentioned group, if necessary. For example, indium oxide (ITO) containing tin oxide, tin oxide (ATO) containing antimony and the like are preferably used. When indium oxide containing tin oxide is used, the content of tin oxide is preferably 1 to 20% by weight, and more preferably 3 to 15% by weight, in the transparent conductive film.

Although the thickness of the transparent conductive film is not particularly limited, it is preferable that the thickness of the transparent conductive film is 10 nm or more in order to form a continuous film having good conductivity with a surface resistance of 1 x 10 &lt; ³ &gt; If the film thickness is excessively increased, transparency deteriorates. Therefore, the thickness is preferably 15 to 35 nm, more preferably 20 to 30 nm. If the thickness of the transparent conductive film is less than 10 nm, the electrical resistance of the film surface becomes high and it becomes difficult to form a continuous film. If the thickness of the transparent conductive film exceeds 35 nm, the transparency may be lowered.

The method of forming the transparent conductive film is not particularly limited, and conventionally known methods can be employed. Specifically, for example, a dry process such as a vacuum deposition method, a sputtering method, and an ion plating method can be exemplified. An appropriate method may be employed depending on the required film thickness. When a transparent conductive film is formed on the first cured resin layer by a dry process such as a sputtering method, the surface of the transparent conductive film substantially retains the surface shape of the first cured resin layer as the underlayer . Therefore, when ridges are present in the first cured resin layer, anti-blocking properties and slipperiness can be favorably imparted to the surface of the transparent conductive film.

The transparent conductive film can be crystallized by a thermal annealing treatment (for example, at 80 to 150 DEG C for about 30 to 90 minutes in an atmospheric environment) if necessary. By crystallizing the transparent conductive film, transparency and durability are improved in addition to the resistance of the transparent conductive film. The means for making the amorphous transparent conductive film into crystalline is not particularly limited, but an air circulating oven or IR heater is used.

For the definition of "crystalline", a transparent conductive film having a transparent conductive film formed on a transparent resin film was immersed in hydrochloric acid having a concentration of 5% by weight at 20 ° C. for 15 minutes, washed with water and dried, , And when the resistance between terminals is not more than 10 k ?, it is assumed that the telephone to the crystalline of the ITO film is completed.

The transparent conductive film may be patterned by etching or the like. The patterning of the transparent conductive film can be carried out by using a conventionally known technique of photolithography. As the etchant, an acid is preferably used. Examples of the acid include inorganic acids such as hydrogen chloride, hydrogen bromide, sulfuric acid, nitric acid, and phosphoric acid, organic acids such as acetic acid, and mixtures thereof, and aqueous solutions thereof. For example, in a transparent conductive film laminate used in a capacitive touch panel or a matrix type resistive touch panel, it is preferable that the transparent conductive film is patterned in a stripe shape. Further, when the transparent conductive film is patterned by etching, if crystallization of the transparent conductive film is performed first, patterning by etching may become difficult. Therefore, the annealing of the transparent conductive film is preferably performed after patterning the transparent conductive film.

The transparent conductive film may be amorphous or crystalline when laminating a carrier film to be described later. For example, after a transparent conductive film is bonded to a transparent conductive film having an amorphous state with a pressure-sensitive adhesive layer interposed therebetween, the film can be annealed to be crystalline.

The transparent conductive film may include metal nanowires. The metal nanowire refers to a conductive material whose material is metal, shape is needle-like or thread-like, and has a diameter of nanometer size. The metal nanowires may be linear or curved. When a transparent conductive layer composed of metal nanowires is used, the metal nanowires are in the form of a mesh, so that even a small amount of metal nanowires can form a good electrical conduction path and a transparent conductive film laminate having a small electrical resistance can be obtained. Further, since the metal nanowires are in the form of a mesh, openings are formed in the gaps of the mesh, and a transparent conductive film laminate having a high light transmittance can be obtained.

As the metal constituting the metal nanowire, any appropriate metal may be used as long as it is a metal having high conductivity. Examples of the metal constituting the metal nanowire include silver, gold, copper, and nickel. In addition, a material obtained by subjecting these metals to a plating treatment (for example, a gold plating treatment) may be used. Among them, silver is preferably copper or gold, and more preferably silver, from the viewpoint of conductivity.

(Optical adjustment layer)

In the present invention, one or more optical adjustment layers may be additionally provided between the first transparent resin film or the first cured resin layer and the transparent conductive film. When the transmittance of the transparent conductive film laminate is increased or when the transparent conductive film is patterned, the optical adjustment layer can reduce the difference in transmittance difference or reflectance between the pattern portion in which the pattern remains and the opening portion in which the pattern is not left, And is used to obtain an excellent transparent conductive film laminate.

The refractive index of the optical adjusting layer is preferably 1.5 to 1.8, more preferably 1.51 to 1.78, and further preferably 1.52 to 1.75. Thereby, the difference in transmittance and the difference in reflectivity can be reduced, and a transparent conductive film laminate excellent in visibility can be obtained.

The optical adjustment layer is formed of an inorganic material, an organic material, or a mixture of an inorganic material and an organic material. Material in forming an optical adjustment _{layer, NaF, Na 3 AlF 6,} LiF, MgF 2, CaF 2, SiO 2, LaF 3, CeF 3, Al 2 O 3, TiO 2, Ta 2 O 5, ZrO 2, ZnO, ZnS, and SiO _x (x is 1.5 or more and less than 2), organic materials such as acrylic resin, epoxy resin, urethane resin, melamine resin, alkyd resin and siloxane polymer. Particularly, as the organic material, it is preferable to use a thermosetting resin comprising a mixture of a melamine resin, an alkyd resin and an organosilane condensate. The optical adjustment layer can be formed using the above materials by a coating method such as a wet method, a gravure coating method or a bar coating method, a vacuum vapor deposition method, a sputtering method, an ion plating method, or the like.

The optical adjustment layer may have nanoparticles having an average particle diameter of 1 nm to 500 nm. The content of the nano-particles in the optical adjustment layer is preferably 0.1 wt% to 90 wt%. The average particle diameter of the nano-particles used in the optical adjustment layer is preferably in the range of 1 nm to 500 nm, more preferably in the range of 5 nm to 300 nm as described above. The content of the nano-particles in the optical adjusting layer is more preferably 10 wt% to 80 wt%, and still more preferably 20 wt% to 70 wt%. By containing nanoparticles in the optical adjustment layer, it is possible to easily adjust the refractive index of the optical adjustment layer itself.

Examples of the inorganic oxide for forming the nano-particle include fine particles such as silicon oxide (silica), hollow nanosilica, titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide and niobium oxide. Among these, fine particles of silicon oxide (silica), titanium oxide, aluminum oxide, zinc oxide, tin oxide, zirconium oxide and niobium oxide are preferable. These may be used singly or in combination of two or more kinds.

The thickness of the optical adjusting layer is preferably from 10 nm to 200 nm, more preferably from 20 nm to 150 nm, even more preferably from 30 nm to 130 nm. If the thickness of the optical adjustment layer is excessively small, it is difficult to form a continuous coating. If the thickness of the optical adjustment layer is excessively large, the transparency of the transparent conductive film laminate tends to be lowered or cracks tend to occur.

(Metal layer, metal wiring)

In the present invention, it is also possible to form a metal layer or a metal wiring on the transparent conductive film. The metal wiring can be formed by forming a metal layer on the transparent conductive film and then etching, but it is preferable that the metal wiring is formed by using a photosensitive metal paste as follows. That is, after the transparent conductive film is patterned, the metal wiring is formed by coating a photosensitive conductive paste described later on the transparent resin film or the transparent conductive film to form a photosensitive metal paste layer, Exposure is performed to the photosensitive metal paste layer through a mask, and then development is performed to form a pattern, followed by drying. That is, it is possible to form a metal wiring pattern by a known photolithography method or the like.

The photosensitive conductive paste preferably contains conductive particles such as a metal powder and a photosensitive organic component. As the material of the conductive particles of the metal powder, it is preferable to contain at least one kind selected from the group consisting of Ag, Au, Pd, Ni, Cu, Al and Pt, more preferably Ag. The volume average particle diameter of the conductive particles of the metal powder is preferably 0.1 mu m to 2.5 mu m.

The conductive particles other than the metal powder may be metal coated resin particles in which the surface of the resin particle is coated with a metal. As the material of the resin particles, the above-mentioned particles are contained, but an acrylic resin is preferable. The metal-coated resin particles are obtained by reacting the surface of the resin particles with a silane coupling agent and coating the surface with a metal. By using the silane coupling agent, the dispersion of the resin component is stabilized and uniform metal-coated resin particles can be formed.

The photosensitive conductive paste may further contain glass frit. The glass frit preferably has a volume average particle diameter of 0.1 mu m to 1.4 mu m, a 90% particle diameter of 1 to 2 mu m and a top size of 4.5 mu m or less. The composition of the glass frit is not particularly limited, but it is preferable that Bi ₂ O ₃ is blended in the range of 30 wt% to 70 wt% with respect to the total amount. The oxides that may be contained in other than Bi ₂ O ₃ may include SiO ₂ , B ₂ O ₃ , ZrO ₂ , and Al ₂ O ₃ . Free glass frit which is substantially free from Na ₂ O, K ₂ O and Li ₂ O.

The photosensitive organic component preferably contains a photosensitive polymer and / or a photosensitive monomer. Examples of the photosensitive polymer include a polymer having a carbon-carbon double bond-containing polymer such as methyl (meth) acrylate and ethyl (meth) acrylate, or a polymer having a polymerizable unsaturated group at the side chain or molecular end of an acrylic resin A reactive group is added, and the like are preferably used. Preferred examples of the photoreactive group include ethylenic unsaturated groups such as vinyl, allyl, acryl, and methacryl groups. The content of the photosensitive polymer is preferably 1 to 30% by weight and 2 to 30% by weight.

Examples of the photosensitive monomer include (meth) acrylate monomers such as methacryl acrylate and ethyl acrylate,? -Methacryloxypropyltrimethoxysilane and 1-vinyl-2-pyrrolidone, One or more of them may be used.

In the photosensitive conductive paste, the photosensitive organic component is preferably contained in an amount of 5 to 40% by weight based on 100 parts by weight of the metal powder from the viewpoint of light sensitivity, more preferably 10 to 30 parts by weight. In the photosensitive conductive paste of the present invention, a photo polymerization initiator, a sensitizer, a polymerization inhibitor, and an organic solvent are preferably used, if necessary.

The thickness of the metal layer is not particularly limited. For example, when a part of the surface of the metal layer is removed by etching or the like to form a pattern wiring, the thickness of the metal layer is appropriately set so that the formed pattern wiring has a desired resistance value. Therefore, the thickness of the metal layer is preferably 0.01 to 200 탆, more preferably 0.05 to 100 탆. When the thickness of the metal layer is within the above range, the resistance of the pattern wiring is not excessively increased and the power consumption of the device is not increased. In addition, the production efficiency of the film formation of the metal layer increases, the amount of heat accumulated at the time of film formation becomes small, and heat wrinkles are less likely to occur in the film.

In the case where the transparent conductive film laminate is a transparent conductive film laminate for a touch panel used in combination with a display, a portion corresponding to the display portion is formed by a patterned transparent conductive film, and a metal wiring made of a photosensitive conductive paste, (For example, a peripheral portion). The transparent conductive film may be used in a non-display portion, and in this case, a metal wiring may be formed on the transparent conductive film.

<Carrier film>

In the present invention, the transparent conductive film laminate may have a carrier film. The carrier film has a pressure-sensitive adhesive layer on at least one side of the protective film. The carrier film forms a transparent conductive film laminate by pasting the transparent conductive film laminate which can be peeled off through the pressure-sensitive adhesive layer and the second main surface side of the transparent conductive film laminate. When the carrier film is peeled from the transparent conductive film laminate, the pressure-sensitive adhesive layer may be peeled together with the protective film, or only the protective film may be peeled off.

(Protective film)

The material for forming the protective film is preferably excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like. As the protective film, a film made of a crystalline resin or an amorphous resin can be used.

Examples of the crystalline resin include a polyester-based resin such as polyethylene terephthalate and polyethylene naphthalate; and a polyolefin-based resin such as polyethylene and polypropylene. A polyester-based resin is preferable.

Examples of the amorphous resin include a cycloolefin resin and a polycarbonate resin. From the viewpoints of excellent light transmission, scratch resistance and water resistance, and good mechanical properties, a polycarbonate resin is preferable. Examples of the polycarbonate resin include an aliphatic polycarbonate, an aromatic polycarbonate, an aliphatic-aromatic polycarbonate, and the like.

The protective film may be formed by applying an etching treatment such as sputtering, corona discharge, a flame, ultraviolet ray irradiation, electron beam irradiation, chemical conversion, oxidation or the like to the surface in advance in the same manner as the transparent resin film, Layer or the like may be improved. Before the pressure-sensitive adhesive layer is formed, the surface of the protective film may be damped and cleaned by solvent cleaning or ultrasonic cleaning as necessary.

The thickness of the protective film is preferably 20 to 150 占 퐉, more preferably 30 to 100 占 퐉, and even more preferably 40 to 80 占 퐉, from the viewpoint of improving workability and the like.

(Pressure-sensitive adhesive layer)

The pressure-sensitive adhesive layer can be used without particular limitation as long as it has transparency. Specific examples thereof include polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy based, fluorine based, natural rubber, Rubber, or the like as a base polymer can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used because it has excellent optical transparency, exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is also excellent in weather resistance and heat resistance.

The method of forming the pressure-sensitive adhesive layer is not particularly limited, and a method of applying a pressure-sensitive adhesive composition to a release liner, drying and then transferring the pressure-sensitive adhesive composition onto a base film (transfer method), a method of directly applying a pressure- ) Or a method by coextrusion. Further, a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a silane coupling agent and the like may be suitably used for the pressure-sensitive adhesive, if necessary. The preferable thickness of the pressure-sensitive adhesive layer is 5 占 퐉 to 100 占 퐉, more preferably 10 占 퐉 to 50 占 퐉, and still more preferably 15 占 퐉 to 35 占 퐉.

<Touch panel>

The transparent conductive film laminate obtained by delaminating the carrier film or the protective film from the transparent conductive film laminate can be suitably applied as a transparent electrode of an electronic device such as a touch panel such as a capacitive type or resistive type .

At the time of forming the touch panel, other substrates such as glass or polymer film can be bonded to one or both main surfaces of the above-mentioned transparent conductive film laminate through a transparent pressure-sensitive adhesive layer. For example, a laminate in which a transparent substrate is bonded to the surface of the transparent conductive film laminate on the side where the transparent conductive film is not formed, via a transparent pressure-sensitive adhesive layer, may be formed. The transparent substrate may be composed of a single substrate film or may be a laminate of two or more substrates (for example, laminated via a transparent pressure-sensitive adhesive layer). The hard coat layer may also be formed on the outer surface of the transparent substrate to be bonded to the transparent conductive film laminate. The pressure-sensitive adhesive layer used for bonding the substrate with the transparent conductive film laminate can be used without particular limitation as long as it has transparency as described above.

When the transparent conductive film laminate of the present invention is used for the formation of a touch panel, the polyester having a low phase difference is used as a base material, thereby having sufficient material strength, low material cost and good productivity, It is possible to provide a touch panel capable of sufficiently suppressing iridescence caused by reflection of external light. If it is outside the use of the touch panel, it can be used as shielding for shielding electromagnetic waves and noise emitted from electronic devices.

Example

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples. The physical properties and the like in the examples and the like were measured as follows.

(Phase difference)

The in-plane retardation of the transparent resin film was measured at a measurement wavelength of 590 nm under an environment of 23 캜 using a polarization / phase difference measurement system (AxoScan, manufactured by Axometrics). In the same manner, the phase difference was measured in a direction inclined at a polar angle of 30 deg. From the normal direction in a direction of an azimuth angle of 45 with respect to the slow axis. Similarly, the phase difference was measured when the film was tilted at 40 DEG with the slow axis direction and the fast axis direction as rotation centers. The order of the measured values of the retardation was determined so as to coincide with the wavelength dispersion of the retardation of the previously obtained transparent resin film. From these measured values, the in-plane retardation value (R0) and the thickness direction retardation value (Rth) of the transparent resin film and the retardation value (R30) in the oblique direction were calculated.

(Measurement of thickness)

With respect to the thickness having a thickness of 1 占 퐉 or more, the measurement was carried out with a micro-gauge thickness meter (manufactured by Mitsutoyo Corporation). The thickness of less than 1 mu m and the thickness of the optical adjustment layer were measured with an instant multi-photometry system (MCPD2000 manufactured by OTSUKA ELECTRONICS CO., LTD.). The thickness of the nano-size such as the thickness of the ITO film and the like was measured by using FB-2000A (manufactured by Hitachi High-Technologies Corporation), and cross-sectional TEM observation was performed using HF-2000 (manufactured by Hitachi High Technologies Corporation) And the film thickness was measured. The evaluation results are shown in Table 1.

(Evaluation of rainbow stains)

As a method of evaluating rainbow stains, evaluation by implication (O to X) was performed. A commercially available polarizer was disposed on a high-luminance backlight. A transparent conductive film was placed on the absorption axis of the first polarizing plate such that the direction of the slow axis of the second transparent resin film (that is, the alignment axis) was 45 °. On the transparent conductive film, The second polarizing plate was further placed on the absorption axis of the polarizing plate such that the absorption axis was perpendicular to the absorption axis, and the change of hue was observed from all directions (polar angle 0 DEG to 80 DEG, azimuth angle 0 DEG to 360 DEG). At that time, a light was hit by using a fluorescent lamp, and a change in color caused by reflection of external light was also observed.

X: The change in hue caused by reflection of external light occurs in all directions. A: The change in hue caused by the reflection of external light is hardly confirmed at any angle.

[Examples 1 to 4]

Various biaxially oriented polyethylene terephthalate (PET) films having in-plane retardation values (R0) and thickness retardation values (Rth) and thickness as shown in Table 1 were prepared as first transparent resin films Respectively.

An ultraviolet curable composition containing zirconia particles having a refractive index of 1.62 (manufactured by JSR Corporation, trade name &quot; Obstar Z7412 &quot;) as an optical adjustment layer was coated on one side thereof to form a coating layer. Subsequently, the coating layer was irradiated with ultraviolet rays on the side where the coating layer was formed, and an optical adjustment layer was formed so as to have a thickness of 100 nm.

Next, a first transparent resin film having an optical adjustment layer formed thereon was placed in a spiral-type sputtering apparatus, and an amorphous indium-tin oxide layer (composition: SnO ₂ : 10 wt %) Was formed to form a transparent conductive film. Thus, a transparent conductive film was produced.

On the other hand, by changing the condition of biaxial stretching as the second transparent resin film, various kinds of polyethylene terephthalate (PET (polyethylene terephthalate) having a retardation value R0 in the in-plane retardation value R0 and a retardation value R30 in the oblique direction as shown in Table 1 ) Were prepared.

By an ordinary solution polymerization, an acryl-based polymer having a weight average molecular weight of 60,000 was obtained with butyl acrylate / acrylic acid = 100/6 (weight ratio). 6 parts by weight of an epoxy cross-linking agent (manufactured by Mitsubishi Gas Chemical Company, trade name &quot; Tetrad C (registered trademark) &quot;) was added to 100 parts by weight of the acryl-based polymer to prepare an acrylic pressure-sensitive adhesive.

The acrylic pressure-sensitive adhesive was applied to the second transparent resin film on one side and heated at 150 占 폚 for 90 seconds to form a pressure-sensitive adhesive layer having a thickness of 10 占 퐉. Next, a silicone-treated side of a PET release liner (25 占 퐉 in thickness) subjected to silicone treatment on one side was laminated on the surface of the pressure-sensitive adhesive layer and stored at 50 占 폚 for 2 days to prepare a second transparent resin film having a release liner Respectively.

The second transparent resin film on which the release liner was formed was peeled off the release liner and then laminated with the first transparent resin film on which the optical adjustment layer was formed to prepare a transparent conductive film laminate. The bonding was carried out such that the slow axis of the first transparent resin film and the slow axis of the second transparent resin film were at an angle of 30 °.

[Comparative Examples 1 to 5]

Except for using various kinds of polyethylene terephthalate (PET) having the in-plane retardation value (R0), the thickness retardation value (Rth) and thickness as shown in Table 1 as the first transparent resin film in Example 1, Under the same conditions as in Example 1, a transparent conductive film laminate was produced.

The evaluation results of the above transparent conductive film laminate are shown in Table 1.

As shown in the results of Table 1, since the retardation values R0 ₁ , R0 ₂ and R30 ₂ of the transparent conductive film laminate of Examples 1 to 4 are in a suitable range, even when observed from the oblique direction, It is possible to sufficiently suppress rainbow stains caused by reflection of light. This means that the rainbow stain when viewing the display through polarized sunglasses is suppressed. On the other hand, in Comparative Examples 1 to 5 in which any of the retardation values R0 ₁ , R0 ₂ and R30 ₂ is not in the appropriate range, when observed from the oblique direction, the effect of suppressing rainbow stains caused by reflection of external light Lt; / RTI &gt;

[Example 4]

A transparent conductive film laminate was produced under the same conditions as in Example 1 except that a cured resin layer was formed on the first transparent resin film in Example 1 as follows.

First, 100 parts by weight of an ultraviolet ray-curable resin composition (trade name "UNIDIC (registered trademark) RS29-120", trade name, manufactured by DIC) and acrylic spherical particles (trade name "MX-180TA" And 0.2 part by weight of a curable resin composition containing spherical particles.

The curable resin composition containing the prepared spherical particles was coated on one side of a PET base material (first transparent resin film) with a thickness of 50 占 퐉 to form a coating layer. Subsequently, ultraviolet rays were applied to the coated layer from the side where the coated layer was formed, and a second cured resin layer was formed so as to have a thickness of 1.0 mu m. A first cured resin layer was formed on the other surface of the PET substrate so as to have a thickness of 1.0 占 퐉 in the same manner as above except that spherical particles were not added thereto. The formation of the optical adjusting layer and the transparent conductive film was performed on the surface of the first cured resin layer.

As a result of evaluating the iridescent smear of the obtained transparent conductive film laminate, sufficient iridescent smear suppression was possible in the same manner as in Example 1.

[Example 5]

A transparent conductive film laminate was produced in the same manner as in Example 1, except that an active energy ray curable adhesive was used in place of the pressure sensitive adhesive.

50 parts by weight of hydroxyethyl acrylamide, 30 parts by weight of methyl acrylate, 40 parts by weight of Aronix M-220 (Toagosei Co., Ltd.) and 1.5 parts by weight of IRGACURE 907 (manufactured by Ciba Japan KK) were mixed and stirred at 50 ° C for 1 hour An active energy ray curable adhesive was obtained.

The active energy ray-curable adhesive was applied to the first transparent resin film using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, gravure roll number: 1000 pieces / inch, rotation rate: 140% So that the thickness of the adhesive layer was 1 占 퐉. Then, the second transparent resin film was bonded through the active energy ray-curable adhesive. Thereafter, the ultraviolet ray (wavelength 365 nm) of the high-pressure mercury lamp was irradiated from the first transparent resin film side, and the adhesive was cured to obtain a transparent conductive film laminate.

As a result of evaluating the iridescent smear of the obtained transparent conductive film laminate, sufficient iridescent smear suppression was possible in the same manner as in Example 1.

1: Protective film
2: Pressure-sensitive adhesive layer
3: Second cured resin layer (anti-blocking layer)
4: First transparent resin film
5: First cured resin layer (hard coat layer)
6: Transparent conductive film
7: Optical adjustment layer
8: Adhesive layer
9: Second transparent resin film
10: Carrier film
11: third cured resin layer (hard coat layer)
12: Fourth cured resin layer (hard coat layer)

Claims (6)

A transparent conductive film laminate having a transparent conductive film, a first transparent resin film, an adhesive layer and a second transparent resin film in this order,
The first transparent resin film, the in-plane retardation value R0 is less than ₁ 150 ㎚,
The second transparent resin film, in-plane retardation value R0 ₂ is 10000 ㎚ above, the retardation value in the direction in which inclined at a polar angle 30 ° from the normal direction in the direction of the azimuth angle 45 ° to the slow axis R30 ₂ is 10000 ㎚ or more, Transparent conductive film laminate. The method according to claim 1,
Wherein the first transparent resin film has a thickness direction retardation value Rth ₁ of 2000 nm or less. 3. The method according to claim 1 or 2,
Wherein the second transparent resin film is an elongated body or a square shaped body, and the orientation axis has an angle of 10 to 45 degrees with respect to a long side or a short side. 4. The method according to any one of claims 1 to 3,
Wherein at least one optical adjustment layer is provided between the first transparent resin film and the transparent conductive film. 5. The method according to any one of claims 1 to 4,
And a cured resin layer on at least one surface of the first transparent resin film or the second transparent resin film. A touch panel comprising the transparent conductive film laminate according to any one of claims 1 to 5.

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